Mode Conditioning Patch Cable
Mode Conditioning Patch Cable, or Mode Conditioning Patch Cord, is a
duplex multimode patch cable that has a small length of single mode
fiber at the start of the transmission length. Designed to "condition"
the laser launch and obtain an effective bandwidth closer to that
measured by the overfilled launch method, the Mode Conditioning Patch
Cable allows for laser transmitters to operate at gigabit rates over
multimode fiber without being limited by DMD. The point is to excite a
large number of modes in the fiber, weighted in the mode groups that are
highly excited by overfill launch conditions, and to avoid exciting
widely separated mode groups with similar power levels. This is achieved
by launching the laser light into a single mode fiber, then coupling it
into a multimode fiber that is off-center relative to the single mode
fiber core.
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