Polarization-independent heterodyne DPSK receiver based on 3×3 coupler for cost-effective udWDM-PON

A polarization-independent heterodyne DPSK receiver with simple architecture based on 3×3 coupler is proposed for cost-effective PON. Results show -49dBm sensitivity for BER=10
^-3
at 1.25Gbps, <;1dB penalty for random polarization tests, and high tolerance to interfering power.