Optical fiber
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Transcript of Optical fiber
OPTICAL FIBER COMMUNICATION
Prepared by : -Bhavishya GargMohit sutharBharat parmarPrashant sharma
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53 Engineers , 53 Vehicles , 53 drivers , 104 labor, 107 patrollers ………
OFC Network
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…along with the SME , Fiber Lead and round the clock OMCR…. Are engaged in maintaining the 13,01,5 kilometer fiber network .
OFC Network
Our patrollers travel approx twelve thousand kilometers on daily basis
HOW FIBRE WORKSThe operation of an Optical Fibre is based on the principle of Total Internal Reflection (TIR).
Light reflects or refracts (bends) depending on the angle at which it strikes a surface. This occurs because different interfaces between materials refract light in different ways.
81 8181 81
n1
n2
n3n=1.49
n=1.48
n=1.8
MULTI MODE:Multi mode fiber was the first type of commercial fiber, which has larger core diameter (50 or 62.5nm) allowing multiple modes of light to propagate through the fiber simultaneously.
It is used primarily for short distances (<2KM) such as LAN communication, due to more loss and less bandwidth capacity.
SINGLE MODE:Single Mode fiber has a much smaller core (8-10nm) that allows only one mode of light at a time to propagate through the core.
This is widely used for all voice/data transmission applications over long distances and high capacities.
125micrometre
8-10 micrometre
125 micrometre
50 - 62.5 micrometre
Single Mode Multi Mode
TYPES OF FIBER USED IN CUMMUNICATION
DEFINITIONmechanical device for joining two pieces of paper or film or magnetic tape or fibers
process of the permanent connection of two pieces of optical fibers is called Splicing
mechanical splicing fusion splicing
Splicing
TYPES OF SPLICING
MECHANICAL SPLICING bonding two fibers
together in an alignment structure
Transparent adhesive - e.g. epoxy resin Commonly used
groove - V-groove
TYPES OF SPLICING
FUSION SPLICING Fusing the two fibers
Flame heating sources - micro-plasma burners, oxy-
hydric micro-burners, electric arc..
Advantage - consistent and easily controlled
heat with adaptability
Possible drawback - weakening of fiber in the vicinity
of splice
TYPES OF SPLICING
COMPARISON
Mechanical splicing Fusion splicing
Reflection losses(-45 db to -55 db)
No reflection losses
Insertion loss(0.2 db)
Very low insertion loss(0.1 db to .15 db)
cost – high Comparatively less
HOW TO IDENTIFY THE FACTORS WHICH GIVES HIGH LOSS ???
1. Clean the fiber and the V-Grooves well to ensure that the external parametersare not affecting the splice loss.
2. View the splice parameters while splicing so that the cleave angle, view angle and geometry of the fiber can be verified.
3. Check whether the machine is okay.
FUSION SPLICER
FSM-16S
manufacturer : Fujikura
manufacturer : Ericsson
SPLICER CLOSER
TEST INSTRUMENTS
OTDR : Optical Time Domain Reflectometer -To detect faults/breaks in the FO links.
Optical Power Meter : To measure the optical power at the end of Fibre.
Optical Source : To send light source in to the Fibre for testing- Laser/LED.
• Single-ended measurement tool• Provides a detailed picture of section-by-section loss• Operates by sending a high-power pulse of light down the fiber and
measuring the light reflected back• Uses the time it takes for individual reflections to return to determine
the distance of each event• Measures/characterizes:
Fiber attenuationAttenuation example (new G.652.C fibers)
0.33 dB/km at 1310 nm (0.35 dB/km for worst case)0.21 dB/km at 1490 nm (0.27 dB/km for worst case)0.19 dB/km at 1550 nm (0.25 dB/km for worst case)
What is an optical time-domain reflectometer (OTDR)?
OTDR BASIC PRINCIPLES
OTDR Basic Principles An OTDR sends short pulses of light into a fiber. Light scattering occurs in the fiber due to discontinuities such as connectors, splices, bends, and faults. An OTDR then detects and analyzes the backscattered signals. The signal strength is measured for specific intervals of time and is used to characterize events.
The OTDR to calculate distances as follows:
Distance = c/n * t/2
c = speed of light in a vacuum (2.998 x 108 m/s)
t = time delay from the launch of the pulse to the reception of the pulse
n = index of refraction of the fiber under test (as specified by the manufacturer)
REFLECTOMETRY THEORY
• The OTDR launches short light pulses (from 5 ns to 20 µs)
• Measuring the difference between the launching time and the time of arrival of the returned signal, it determines the distance between the launching point and the event.
GIS :GEOGRAPHIC INFORMATION SYSTEM
WHAT IS GIS :
Geographic information system (GIS): a computer-based information system that enables capture, modeling, storage, retrieval, sharing, manipulation, and presentation of geographically referenced data