Real-Time PMD Tolerance Measurements of a PIC-Based 500 Gb/s Coherent Optical Modem

We present real-time polarization mode dispersion (PMD) tolerance measurement results with a commercially available 500 Gb/s coherent modem. The first- and second-order PMD space is explored, showing that peak values of 500 ps of static, first-order PMD (differential group delay) have small penalties. The system was stressed using fast scrambling, with polarization change of over 10 000 rad/s, along with high mean PMD. Penalties were small with sufficient equalization.