Mode Conditioning Patch Cable

Mode conditioning cords come in the form of a simple duplex patch cable, making them easy to install in a system without the need for additional hardware or components. Lengths can range from one meter to support practically any network topography. 

The single-mode launch nature of the -LX transceiver modules used for Gigabit Ethernet creates the need for this patch cord. These modules need to operate for both singlemode and multimode fibres. Launching a single-mode laser into the centre of a multimode fibre can create multiple signals that confound the receiver at the other end of the fibre. These multiple signals limit the cable distance lengths for running Gigabit Ethernet. A mode conditioning patch cord removes these multiple signals by allowing the single-mode launch to be offset away from the centre of a multimode fibre. This offset point creates a launch, like a typical multimode LED launcher. 

Mode conditioning cables are used in pairs with one cable at each end to connect the equipment to the trunk cable. 

If you are working with a Gigabit LX switch equipped with SC or LC connectors, make sure to connect the singlemode part of the cable to the transmit side and the multimode part to the receive side of the equipment. This configuration must be maintained on both ends. The swap of transmitting and receive can only be done at the cable plant side.  

Mode conditioners give a way of offsetting a singlemode fibre core with a corresponding multimode fibre. This calibrated offset reduces a phenomenon called DMD (Differential mode dispersion). This can cause the transmitting laser pulse to spread out and merge into neighbouring pulses, which in turn can create signal errors. 

 

Speak to one of our fibre specialists to discuss your product requirements. Email sales@cmwltd.co.uk or contact us on 01234 848030.