Optical filter architecture for approximating any 2 X 2 unitary matrix.

A new optical filter architecture and a new design methodology are presented for approximating any frequency-dependent 2 x 2 unitary matrix that consists of two coupled phase and amplitude responses. Design examples are provided for the compensation of polarization mode dispersion (PMD) by approximating the inverse of a synthesized fiber's Jones matrix. Compensation of the channel PMD over the signal bandwidth is demonstrated, as required for demultiplexing channels in a polarization-multiplexed system.