Polarization mode dispersion tolerance of an adaptive threshold receiver

The mitigation of polarization mode dispersion (PMD) in lightwave systems has been an elusive goal. Optical techniques can provide perfect mitigation in theory but add cost. Electrical techniques could potentially be inexpensive, depending on the bit rate, but cannot provide perfect mitigation in direct-detection systems owing to. the loss of phase information in the detector. Here we describe the performance of a receiver employing a simple electrical technique: an adaptable decision threshold.