Patent ID: 7983573

Claim:
An optical receiver comprising: a signal processor having constructive and destructive transfer functions for receiving a modulated optical input signal and issuing signals at constructive and destructive outputs, respectively, the signal processor including a delay line interferometer (DLI) having two signal paths having a transit time difference for differentially demodulating said modulated optical input signal, said transfer functions determined at least in part by a free spectral range (FSR) defined by said transit time difference; at least one transfer phase element disposed in the signal processor, the transfer phase element for providing a controllable transfer function phase for at least one of said transfer functions with respect to a frequency of said input signal, the transfer phase element being disposed in one of said signal paths for adjusting a signal phase of a signal traversing said signal path for adjusting said transfer function phase, the transfer phase element including an FSR element disposed in said DLI having a selected FSR delay for providing said transit time difference not equal to a symbol time for said modulated optical input signal; and a transfer phase controller coupled to the transfer phase element for controlling said transfer function phase for maximizing a difference between signal powers for said constructive and destructive outputs.