Mode conditioning cable are designed for Gigabit Ethernet multimode applications at 1300nm wavelength; the application standard is IEEE 802.3z. All mode conditioning fiber optic patch cords are made with duplex cable; with a single mode to multimode offset fiber connection part in one of the two legs
Here is the reason we need to use the mode conditioning patch cord : the Gigabit Ethernet application standard requires the use of fiber optic light to achieve the specified data transmitting rates. Usually people use long wave transceiver modules for Gigabit Ethernet, these modules have to operate both single mode and multi mode fibers. And as we know, multimode fiber manufacturing techniques create index of refraction anomalies along the centerline of the multi mode fiber core. When a highly concentrated single mode fiber optic light is sent into the center of a multimode fiberglass, the modes that propagate through the index of refraction anomalies spread out in time causing modal dispersion, this effect is called differential mode delay. Differential mode delay results in reduced bandwidth over distance. By allowing the single mode laser launch to be offset away from the center of the multi mode fiber the mode conditioning patch cord reduces the effect of such differential mode delay.