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Fiberstore (FS.COM) | Fiber Type and Corresponding Optical Transceivers
Fiber optic patch cable as the basic element of a network, transmits signals through strands of glassor plastic fiber. Fiber optic cables are available in multimode and single-mode fibers terminated withLC, SC, ST, LC, FC, MTRJ, E2000 connectors in simplex and duplex. The typical multimode fiber usedin telecom or datacom applications has a core size of 50 or 62.5 microns. Single-mode fiber shrinksthe core size down to 9 microns so that the light can only travel in one ray. Different fiber types likemultimode or single-mode fibers connect with fiber optic transceivers resulting in differentperformances, which makes a huge impact on the network application. Here is what you need toknow about the fiber types and the corresponding optical transceivers for network infrastructure.
Internal Structure of Fiber Optic CableAn optical fiber is a flexible filament of very clear glass capable of carrying information in the formof light. Single-mode fiber optic cable has a small diametral core of 9/125 microns that allows onlyone mode of light to propagate, which results in light reflections, lower attenuation and creating theability for the signal to travel faster, further. That’s why single-mode fibers are typically used inlong-reach applications.
MM fiber patch cords, however, has a large diametral core of 50/125 and 62.5/125 in constructionthat allows multiple modes of light to propagate. Therefore, the number of light reflections createdas the light passes through the core increases, creating the ability for more data to pass through at agiven time. Because of the high dispersion and attenuation rate with this type of fiber, the quality ofthe signal is reduced over long distances. The above picture shows the inner structure of fiber opticcables.
Fiber Type andCorresponding Optical
Transceivers
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Fiberstore (FS.COM) | Fiber Type and Corresponding Optical Transceivers
Factors When Choosing Single-mode or Multimode FiberDifferent core diameters of single-mode and multimode fiber optic cables affect the opticalproperties and have a direct impact on system performance. Besides this, other factors likebandwidth, attenuation and costs also have the biggest impact on the system performance. Figure 2gives you a vivid description of single-mode and multimode fiber.
Attenuation is the reduction of signal power, or loss, as light travels through an optical fiber. Fiberattenuation is measured in decibels per kilometer (dB/km). The higher the attenuation, the higherrate of signal loss of a given fiber length. Single-mode fibers generally operate at 1310 nm (for shortrange) while multimode fibers operate at 850 nm or 1300 nm. Attenuation is not usually consideredto be the main limiting factor in short rang transmissions. But it can cause big differences in highspeed network such as 100Gb/s.
Bandwidth means the carrying capacity of fiber. For single-mode fiber, the modal dispersion can beignored since its small core diameter. Bandwidth behavior of multimode fibers is caused bymulti-modal dispersion during the light traveling along different paths in the core of the fiber. It hasan influence on the system performance and data rate handling. Multimode fiber uses a gradedindex profile to minimize modal dispersion. This design maximizes bandwidth while maintaininglarger core diameters for simplified assembly, connectivity and low cost. So manufacturers start todevelop higher-performance multimode fiber systems with higher bandwidth.
Costs: A fiber optic transceiver usually consists the optical light sources, typically LED–light emittingdiode and optical receivers. Since the core diameter size and primary operating wavelengths ofsingle-mode fiber and multimode fiber are different, the associated transceiver technology andconnectivity will also be different. So is the system cost.
To utilize the single-mode fibers generally for long distance applications, transceivers with lasersthat operate at longer wavelengths with smaller spot-size and narrower spectral width. But thesekinds of transceivers need higher precision alignment and tighter connector tolerance to smaller
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Fiberstore (FS.COM) | Fiber Type and Corresponding Optical Transceivers
core diameters. Thus, it causes higher costs for single-mode fiber interconnections. To lower thecost, manufacturers produce transceivers based on VCSEL (vertical cavity surface emitting laser), forexample, 10G-SFPP-SR is a SFP+ transceiver support a link length of 300m, which are optimized foruse with multimode fibers. Transceivers applying low cost VCSEL technology to develop for50/125μm multimode fibers, take advantage of the larger core diameter to gain high couplingefficiency and wider geometrical tolerances. OM3 and OM4 multimode fibers offer high bandwidthto support data rates from 10Mb/s to 100Gb/s.
Fiber Type and Associated Optical Transceiver Compatibility MatrixFrom a technician standpoint, optical transceivers should be compatible with fiber optic cables,meaning that multimode transceivers should only connect with multimode fiber optic cables, or youmay end up with an error. Table 3 summarizes various optical interfaces and their performance overthe different fiber types. The table specifies the maximum reach achievable over each fiber typeand the requirement for a mode conditioning patch cord.
This table is directly derived from the IEEE 802.3-2005 standard, if you comply with the standard,these performances are guaranteed and longer reaches may be achievable depending on thequality of each link. To ensure whether a link can work, all you can do is to try and see if theperformance is satisfactory. The link should be either error-free for critical applications, or the biterror should remain below 10-12 as per minimum standard requirement. For instance, it may bepossible to reach much longer distances than 550 m with an OM3 laser-optimized fiber and1000BASE-SX interfaces. Also, it may be possible to reach 2 km between two 1000BASE-LX devicesover any fiber type with mode conditioning path cords properly installed at both ends. Single modefiber patch cables as noted before, are suitable for long-haul application. Although the optics aremore expensive, they’re offering much longer reach, which makes them an ideal choice for networkinfrastructure.
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Fiberstore (FS.COM) | Fiber Type and Corresponding Optical Transceivers
ConclusionChoosing the right fiber for your network application is a critical decision. Whether to usesingle-mode or multimode fiber for your infrastructure, no one can give your the best answer. Onlyby fully understand the system requirements and select the appropriate fiber can you maximize thevalue and performance of your cabling system. FS.COM offers cost-effective fiber optic patch cablesto meet the requirements of all the customers. If you are interested, please send your request to us.
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Fiberstore (FS.COM) | Fiber Type and Corresponding Optical Transceivers
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Notice: This document is for informational purposes only and does not set forth any warranty, expressed orimplied, concerning any equipment, equipment features, or service offered or to be offered by Fiberstore.Fiberstore reserves the right to make changes to this document at any time, without notice, and assumes noresponsibility for its use. This information document describes features that may not be currently available.Contact a Fiberstore sales team for information on feature and product availability.
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