Currently,as decribed,Fiber Patch Cables is categorized into groups:single-mode and multi-mode fiber,nevertheless,there exists another kind of fiber like the POF.The mode refers to the path a photon takes in going from one side of the fiber to the other.
in this type of fiber ,all photons take the same path along the fiber,This is because the center of the fiber is very narrow.According to the ANSI the fiber has 8.5 micron core with 125-micron cladding.This factor reduces the signal loss and the ISI the fiber has 8.5 micron core with 125-micron cladding.This factor reduces the signal loss and the ISI(intersymbol interference).Therefore,with single-mode fiber used primrily in telecommunications networks,fibers are characterized by long distance links and high capacity.
It is the most reliable mudium,but it has an important drawback for the fact that,at this moment ,it is not clear that SFF connectors perform well with SMF (at least,it is not easy to relibly connect two SMFs to the field).As fabrication processes are improving quickly,it will be possible to have enough concentricity in fibers as to connect them aliging their claddings.Advantages of using SMF are well know:
.Its bandwidth is enough to support,not only the current traffic but also the future one.
.Greater distance:fiber can be run several kilometers.
.Low attenuation:Light signals meet little resistance,so data can travel faster
.It has also some drawbacks that can be reduced to one:
.The core diameter is very small so ,problems to acccess every home(conectivity)will arise.
.The narrow size of the core causes that other elements of the system.
currently,due to the great demand for increasin bandwidth ,it has prompted the release of the 802.3z standard for Gigabit Ethernet over optical fiber,1000Base-LX requires the use of launch conditioning patch cord to allow the proper propagation of the laser VCSEL light along the multimode fiber .
The Mode conditioning Patch cord is designed for long wave multimode applications of Gigabit Etheernet,It is compliant with this IEEE 802.3z application standard,This patch cord consists of connectors on each end of a cable with a single-mode fiber offeset to a multimode fiber connection pointin between.
The need for this patch cord is due to the single mode launch nature of the LX or long wave transceiver modules used for Gigabit Ethernet.These modules have to operate for both single mode and multimode fibers.Launching a signals that confuse the receiver at the other end of the fiber.These multiple signals,caused by Differential Mode Delay effects,severely limit the cable distance lengths for operating Gigabit Ethernet,A mode conditioning patch cord eliminates these multiple signals by allowing the single mode launch to be offset away from the center of amultimode fiber.bend in a fiber is function of the refractive index of the cord and surrounding cladding.
Handling problems:It will become particularly acute for fiber to the Home.For example the ends of the fiber must be perfectly aligned and as clean as possible.