Fiber-Optic Cable Basics - College of Southern Nevada

120
10/7/2009 1 Network Cabling Illuminated Chapter 7 Fiber-Optic Media Learning Objectives After reading this chapter you will be able to: Understand fiber-optic cabling and how it differs from copper cabling Understand the theory behind fiber-optic media Understand how fiber-optic cables are manufactured Discuss enclosures and patch panels Identify fiber-optic cabling connector types Understand the increased bandwidth capacity of fiber-optic cabling Understand the advantages fiber-optic cabling provides over copper cabling Network Cabling Illuminated 2 Fiber-Optic Cable In recent years, fiber-optic cabling has been replacing copper cable as the media of choice for backbone network connectivity for several reasons. Fiber-optic cable has an expanded bandwidth capacity to reach longer distances, and it resists outside interferences such as electromagnetic noise. Network Cabling Illuminated 3 Fiber-Optic Cable Basics Fiber-optic cable is made up of three main components The core The cladding The protective buffer coating Network Cabling Illuminated 4

Transcript of Fiber-Optic Cable Basics - College of Southern Nevada

Page 1: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 2: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 3: Fiber-Optic Cable Basics - College of Southern Nevada

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3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 4: Fiber-Optic Cable Basics - College of Southern Nevada

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4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 5: Fiber-Optic Cable Basics - College of Southern Nevada

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5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

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6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 7: Fiber-Optic Cable Basics - College of Southern Nevada

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1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 8: Fiber-Optic Cable Basics - College of Southern Nevada

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2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 9: Fiber-Optic Cable Basics - College of Southern Nevada

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3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 10: Fiber-Optic Cable Basics - College of Southern Nevada

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4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 11: Fiber-Optic Cable Basics - College of Southern Nevada

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5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

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6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 13: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 14: Fiber-Optic Cable Basics - College of Southern Nevada

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2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 15: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 16: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 17: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 18: Fiber-Optic Cable Basics - College of Southern Nevada

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6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 19: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 20: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 21: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 22: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 23: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 24: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 25: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 26: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 27: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 28: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 29: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 30: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 31: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 32: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 33: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 34: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 35: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 36: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 37: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 38: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 39: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 40: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 41: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 42: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 43: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 44: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 45: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 46: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 47: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 48: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 49: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 50: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 51: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 52: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 53: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 54: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 55: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 56: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 57: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 58: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 59: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 60: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 61: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 62: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 63: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 64: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 65: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 66: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 67: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 68: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 69: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 70: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 71: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 72: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 73: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 74: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 75: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 76: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 77: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

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10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 79: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 80: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 81: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 82: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 83: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 84: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 85: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 86: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 87: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 88: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 89: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 90: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 91: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 92: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 93: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 94: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 95: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 96: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 97: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 98: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 99: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 100: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 101: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 102: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 103: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 104: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 105: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 106: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 107: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 108: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 109: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 110: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 111: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 112: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 113: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 114: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D

Page 115: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

1

Network Cabling IlluminatedChapter 7

Fiber-Optic Media

Learning Objectives

• After reading this chapter you will be able to:

• Understand fiber-optic cabling and how it differs from coppercabling

• Understand the theory behind fiber-optic media

• Understand how fiber-optic cables are manufactured

• Discuss enclosures and patch panels

• Identify fiber-optic cabling connector types

• Understand the increased bandwidth capacity of fiber-opticcabling

• Understand the advantages fiber-optic cabling provides overcopper cabling

Network Cabling Illuminated 2

Fiber-Optic Cable

• In recent years, fiber-optic cabling has beenreplacing copper cable as the media of choicefor backbone network connectivity for severalreasons. Fiber-optic cable has an expandedbandwidth capacity to reach longer distances,and it resists outside interferences such aselectromagnetic noise.

Network Cabling Illuminated 3

Fiber-Optic Cable Basics

• Fiber-optic cable is made up of three maincomponents

– The core

– The cladding

– The protective buffer coating

Network Cabling Illuminated 4

Page 116: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

2

Fiber-Optic Cable Basics

• In some cases, the protective buffer coating issupported by a layer of Kevlar fibers to make thecable stronger while it is being pulled

• To minimize distortion in the data signal, it isnecessary to use glass that is extremely pure

• When the feasibility of using fiber-optic cable totransmit data was first discussed, it was decided thatin order to be usable, the cable would have to bepure enough to retain 1% of the original signalstrength over a distance of 1 kilometer

Network Cabling Illuminated 5

Refraction and Reflection

• Light changes speed as it moves between dissimilarelements

• Refraction is light bending at the junction of twodissimilar elements as it changes speed

• Each element has a refractive index, or the amountof refraction that it allows to take place

• Reflection is light bouncing at the junction of twodissimilar elements

Network Cabling Illuminated 6

Refraction and Reflection

• Fiber-optic cable uses these principals ofreflection and refraction to transmit data.Light waves are guided down the core of thefiber-optic cable by being reflectedthroughout the length of the cable. Thedifference in the refractive index of the mediabetween the core and cladding determine thecable’s ability to reflect light.

Network Cabling Illuminated 7

Refraction and Reflection

• Controlling the angle at which the lightreflects down the length of the core makes itpossible to control how efficiently the lightpulses will reach the receiving end

Network Cabling Illuminated 8

Page 117: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

3

Fiber-Optic Transmitters

• Predominantly LEDs or laser diodes (LDs),although some are vertical cavity surfaceemitting lasers (VCSELs)

• Lasers transmit at a significantly higher powerrange than do LEDs, so in long-distance fiber-optic systems, lasers are the transmitter ofchoice

Network Cabling Illuminated 9

Fiber-Optic Transmitters

• Never look directly into a fiber-optic cable that is connected to alaser. Serious eye injury canoccur. If you are not sure if it islaser or LED, don’t take anychances

Network Cabling Illuminated 10

Optical Receivers

• Fiber-optic receivers perform two functions:

they must receive the light waves from the

transmitter and then convert them into

electrical signals

Network Cabling Illuminated 11

Fiber-Optic Transmission

• The light travels down the length of the fiber-optic cable by continuously reflecting backfrom the junction of the core and claddingusing the principals of reflection andrefraction

Network Cabling Illuminated 12

Page 118: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

4

Fiber-Optic Transmission• Attenuation

– loss of light as measured in decibels per kilometer (dB/km)

• Dispersion

– As light waves travel away from their source, they fan outor disperse

• Bandwidth

• Multiplexing

– The two main types of multiplexing in common use aretime division multiplexing (TDM) and wavelength divisionmultiplexing (WDM)

Network Cabling Illuminated 13

Types of Optical Fiber

• Multimode

– The core of a multimode cable is usually either 50or 62.5 microns in diameter, although 62.5microns is in more widespread use

• Single Mode

– The common diameter of a single-mode core is 8to 9 microns (remember, a human hair isapproximately 50 microns in diameter)

Network Cabling Illuminated 14

Enclosure Systems and PatchPanels

Network Cabling Illuminated 15

Fiber-Optic Connectors

• Several different types of connectors areavailable for fiber-optic patch cables, such asLC, FC, and MTRJ

• The two most common types of fiber-opticconnectors in use today are the ST-style andthe SC-style connector

Network Cabling Illuminated 16

Page 119: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

5

Security Considerations

• Security on fiber-optic cables is tighter than

that of copper cables. If a fiber-optic cable is

tapped into, it would break the core, which

would shut down the signal and render it

useless

Network Cabling Illuminated 17

Constructing Fiber-Optic Cabling

• One common misconception about glass fiber-

optic cable is that it is very fragile and weak. In

fact, the opposite is true. The high level of

purity of the glass that is used to manufacture

fiber-optic cable is what gives it its strength

Network Cabling Illuminated 18

Fiber Types

• Loose Tube

– Loose-tube cable consists of many individual strands offiber-optic cable encased in a protective sheath known as abuffer tube. Loose-tube cabling is usually found in outdoorfiber-optic installations

• Tight Buffered

– Tight-buffered cable consists of a single strand of fiber-optic cable enclosed in a 900-micron protective buffersheathing. Tight-buffered cable is generally used for indoorapplications

Network Cabling Illuminated 19

Common Cable Configurations

• Fiber-optic patch cables are available with ST–ST connectors (ST style on both ends), SC–SCconnectors, and SC–ST connectors (alsoknown as hybrids). Fiber-optic patch cablesare available in many different lengths. It is agood rule of thumb to use the shortest cablepossible to reduce the amount of slack in thecable

Network Cabling Illuminated 20

Page 120: Fiber-Optic Cable Basics - College of Southern Nevada

10/7/2009

6

Network Cabling Illuminated 21

Optical Fiber Connectors• SC Connector ST Connector

• To remember the difference between SC and STconnectors, think of SC as stick and click, and ST asstick and twist

Network Cabling Illuminated 22

Termination• It is not recommended that IT technicians try to

terminate fiber on your own because it is a difficultprocess. Unless you take a course such as:

– ET287B Introduction to Fiber Optic

• A simple mistake can ruin the costly fiber, thusrendering the materials useless because there is noway to turn back from most mistakes.

• Should you be faced with the necessity to terminate(or even splice) fiber cables, proceed with caution.Many difficulties can arise during the process, suchas the following

Network Cabling Illuminated 23

Termination

• End gap -A

• Concentricity – B

• Uneven ends – C

• Air gaps - D