Patent ID: 8090271

Claim:
A differential delay detection system, comprising: an optical splitter to split an incoming optical signal between a first path and a second path; the first path comprising: a cross-polarization interferometer configured to separately generate polarization independent outputs using split paths and to generate cross-polarization interference outputs; a polarization demultiplexer configured to combine the polarization independent outputs and the cross-polarization interference outputs from the cross-polarization interferometer with updated coefficients received from the second path to remove the cross-polarization mixed signals; and the second path comprising: a training signal receiver configured to compute the updated coefficients and output the updated coefficients to the polarization demultiplexer; wherein the first and second polarization signal are further split and the cross-polarization interferometer further comprises a polarization controller configured to rotate a split version of the first polarization signal by 90 degrees to form a rotated version of the first polarization signal and a split version of the second polarization signal and the rotated version are cross-coupled with one tap delays to output the cross-polarization interference outputs.