CD-insensitive PMD monitoring of a high-speed polarization-multiplexed data channel

We experimentally demonstrate a polarization-mode dispersion (PMD) monitoring technique that is insensitive to chromatic dispersion (CD) utilizing a polarizer and a low-speed detector for an 80-Gb/s polarization-multiplexed return-to-zero differential phase-shift-keying (pol-muxed RZ-DPSK) data channel. Measured RF power increment of 16.2 dB, which is insensitive to 0 approximately 100 ps/nm CD, is measured in the presence of the increasing differential group delay (DGD) from 0 to 12 ps. High-speed components are not required for monitoring the PMD on the pol-muxed data channel, which means that the proposed technique is potentially applicable to the higher speed pol-muxed data channels.