1.8 MS/s Polarimetry of 160-Gb/s PDM-QPSK Signal Based on Polarization-Selective RF Power Detection

A novel polarimeter identifies one or three main polarization axes of polarization-modulated, nominally unpolarized signals such as PDM-QPSK, PDM-QAM, PS-QPSK. It measures the electrical AC power detected behind several polarization analyzers and calculates the axes iteratively. The channel polarizations of a 160-Gb/s, 40-Gbaud PDM-QPSK signal are analyzed this way, at sampling speeds of 0.9 MHz and 1.8 MHz.