Patent ID: 8270835

Claim:
A method for reducing cross-phase modulation in an optical signal, comprising: receiving an optical signal comprising a plurality of channels, wherein the information being communicated in a first set of one or more of the channels is modulated using one or more single-polarization modulation techniques and wherein the information being communicated in a second set of one or more of the channels is modulated using one or more dual-polarization modulation techniques; splitting the optical signal into at least a first copy of the optical signal and a second copy of the optical signal; terminating the second set of channels in the first copy; applying a differential group delay to the second copy, the differential group delay introducing a walk-off between symbols communicated in a first polarization component of the second set of channels and the symbols of a second polarization component of the second set of channels; terminating the first set of channels in the second copy; and combining the first set of channels in the first copy and the second set of channels in the second copy and forwarding the combined channels.