Patent ID: 8005375

Claim:
An optical receiver system with a double-pass architecture processing both polarizations in a demodulator, comprising: a polarization demultiplexing and polarization mode dispersion mitigation section, comprising: a polarization controller connected to a first port of a circulator; a first birefringent element connected to a second port of the circulator; a first single-stage waveplate connected to the first birefringent element; a second birefringent element connected to the first single-stage waveplate; a mirror connected to the second birefringent element; and a control processor configured to control the polarization controller and the first single-stage waveplate responsive to a feedback signal; wherein the circulator and mirror are operable to form the double pass architecture; and a demodulator, comprising: a delay interferometer receiving an output at a third port of the circulator; first and second polarization beam splitters each receiving an output from the delay interferometer, wherein the delay interferometer is configured to send a first and second polarization to both the first and second polarization beam splitters; a first set of photo-detectors receiving the first polarization from each of the first and second polarization beam splitters; and a second set of photo-detectors receiving the second polarization from each of the first and second polarization beam splitters.