Optic Fiber

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OF Connector Types

Transcript of Optic Fiber

  • Fiber Optic ConnectorsBasics, Styles, Trends -Troy Bowen, JFC Solutions

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  • ConfidentialAgendaHistory and MarketStandardsConstruction and Fiber TypesConnector typical componentsPerformance Definitions and MeasurementConnector TypesApplicationsFutureProduct Spotlight - Leviton FastCAM Connector

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  • ConfidentialHistory1965 - Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables demonstrated that optical fiber could be a practical medium for communication, if the attenuation could be reduced below 20 dB per kilometer 1970 - Researchers Robert D. Maurer, Donald Keck, Peter Schultz, and Frank Zimar working for American glass maker Corning Glass Works. They manufactured a fiber with 17 dB optic attenuation per kilometer by doping silica glass with titanium.1977 - On April 22, General Telephone and Electronics sent the first live telephone traffic through fiber optics, at 6 Mbit/s, in Long Beach, California.1986 - The erbium-doped fiber amplifier, which reduced the cost of long-distance fiber systems by eliminating the need for optical-electrical-optical repeaters, was invented by David Payne of the University of Southampton, and Emmanuel Desurvire at Bell Laboratories.

    And the industry and applications have exploded since!!!

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  • ConfidentialThe MarketThere are 110 design types of Fiber Optic connectors.Total factory shipments of Fiber Optic connectors were $1.273 billion in 2005 and are projected to reach $1.976 billion by the year 2010.Copyright 2006, Fleck Research, Global Connector Research Group, Inc.

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  • ConfidentialConnector StandardsTIA/EIA-4750000-B Generic Specification for Fiber Optic ConnectorsTIA/EIA-604 Fiber Optic Connector Intermateability Standards (FOCIS) www.tiaonline.org

    GR-326 Generic Requirements for Single-Mode Optical Fiber Connectors GR-1435 Generic Requirements for Multi-fiber Optical Connectors www.telcordia.com

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  • ConfidentialThe GlassTypical Construction

    Example: 8/125mCore 8 micron diameterCladding 125 micron diameter

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  • ConfidentialThe GlassSingle-mode 8/125mFiber supporting only one mode is called single-mode Default Premises Cable Jacket Color = YellowUses Lasers to transmit signalThe laser can be multiplexed in order to send many different signals down one fiber. 1310 and 1550nm are the most common wavelengthsSingle-mode systems can send a signal much faster and for longer distance than multimode systems.

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  • ConfidentialThe GlassMultimode - 62.5/125m and 50/125mFiber with large (greater than 10m) core diameter is called multimode fiberDefault Premises Cable Jacket Color = Orange or Aqua (for laser optimized fibers)The first multimode fiber size was 100/140m. These larger sizes are currently used for instrumentation applications. Uses LEDs to transmit signal850nm and 1310nm are the most common wavelengthsLEDs can not be multiplexedPrimarily used in short distance communication (LAN)Less than 2km

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  • ConfidentialSingle-mode Multimode Comparison

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  • ConfidentialThe ConnectorFiber optic connectors have traditionally been the biggest concern in using fiber optic systems. Connectors were once unwieldy and difficult to use.Connector manufacturers have standardized and simplified connectors greatly. This increasing user-friendliness has contributed to the increase in the use of fiber optic systems The sole purpose of a connector is to mate fiber-optic cable with minimal loss of light. Connectors are designed for many different applications including telecommunications, local area networks, and harsh environments.

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  • ConfidentialConnector BasicsThe Connector BodyAlso called the connector housing, the connector body holds the ferrule. Usually constructed of metal or plastic and includes one or more assembled pieces which hold the fiber in place. Details vary among connectors, but bonding and/or crimping is commonly used to attach strength members and cable jackets to the connector body.The ferrule extends past the connector body to slip into a coupling device

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  • ConfidentialConnector BasicsThe CableThe cable is attached to the connector body. Typically, a strain-relief boot is added over the junction between the cable and the connector body, providing extra strength to the junction.

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  • ConfidentialConnector BasicsThe FerruleThe fiber is mounted in a long, thin cylinder, the ferrule, which acts as a fiber alignment mechanism. The ferrule is bored through the center at a diameter that is slightly larger than the diameter of the fiber cladding. The end of the fiber is located at the end of the ferrule. Ferrules are typically made of metal or ceramic, but they may also be constructed of plastic.The most distinct differentiations between connector types are the diameter of the ferrule, 2.5 mm or 1.25 mm, and the type of polish.

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  • ConfidentialCoupling of ConnectorsThe Coupling DeviceMost fiber optic connectors do not use the male-female configuration common to electronic connectors. Instead, a coupling device such as an alignment sleeve is used to mate the connectors.Similar devices may be installed in fiber optic transmitters and receivers to allow these devices to be mated via a connector. These devices are also known as feed-through bulkhead adapters.

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  • ConfidentialPerformance MeasuresInsertion Loss (IL) is the amount of optical power lost as a result of a connection. Expressed in decibels, it is the ratio of measured optical power before and after the connector. It always is tested because it is the most important connector parameter. Return Loss (RL) a term applied to the light reflection in the connectors interface that return to the source. The greater the absolute value, the better: Example: -60dB RL is better than -35dB RL.

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  • ConfidentialPerformance MeasuresBack Reflection represents the total accumulated light reflected back to the source along a link. This return of the light is due to different physical phenomena such as multiple connector back-reflections, bad splicing, etc. Someeffects of back reflection include the following:Less light is transmittedCauses interference with light source signalsCreates higher bit error rate (BER) in digital systemsReduces signal-to-noise ratio (SNR) in analog systemsCATV systems virtually standardize on APC type connectors High back reflection cancause bad or harmfulconsequences such as:Causes fluctuations in the light sources central wavelengthCauses fluctuations in its output powerDamages the light source (transmitter)permanently

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  • ConfidentialConnector LossConnector loss is caused by a number of factors. Loss is minimized when the two fiber cores are identical and perfectly aligned, the connectors are properly finished and no dirt is present. Only the light that is coupled into the receiving fiber's core will propagate, so all the rest of the light becomes the connector loss.

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  • ConfidentialTypes of PolishesThe polish on a fiber connector dictates the amount of back reflection. Back reflection is a measure of the light reflected off the polished end of a fiber connector measured in negative dB. The physical-contact (PC) polish is a flat finish of the connecting areaThe angled physical contact (APC) is at an 8 angle. An APC greatly reduces back reflections caused by the physical interface.

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  • ConfidentialConnector StylesAnaerobic Adhesives: These connectors use a quick setting adhesive. They work well if your technique is repeatable, but often they do not have the wide temperature range of epoxies, so they are only used indoors. Thus, generally used for factory terminations only.Epoxy/Polish: These connectors are the simple "epoxy/polish" type where the fiber is glued into the connector with epoxy and the end polished with special polishing film. These provide a very reliable connection with low losses. They can be factory or field installed.

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  • ConfidentialConnector StylesCrimp/Polish: Rather than glue the fiber in the connector, these connectors use a crimp on the fiber to hold it in. Early types offered "iffy" performance, but today they are pretty good, if you practice a lot. Expect to trade higher losses for the faster termination speed. And they are more costly than epoxy polish types. Pre-Polished: Many manufacturers offer connectors that have a short stub fiber already epoxied into the ferrule and polished perfectly, so you just cleave a fiber and insert it like a splice. While it sound like a great idea, it has several downsides. First it is very costly, 2 to 3 times as much as an epoxy polish type. Second, you have to make a good cleave to make them low loss.

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  • ConfidentialConnector Types Biconic (FOCIS 1)The Biconic connector was developed by AT&T and became the de facto standard for long haul telecommunications. The Biconic connector features a cone-shaped tip, which holds a single fiber.It is non-metallic, using polymer and epoxy in its construction.Telcos have long since adopted other connectors, mainly the SC due to the drawbacks of the Biconic such as its large size and the fact that it is mated by screwing it into its coupling.Screw coupling makes its performance sensitive to rotational changes.

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  • ConfidentialConnector Types ST (FOCIS 2)ST stands for Straight Tip - a quick release style connector developed by AT&T. STs were the predominant connector in the late 80s and early 90s.ST