Coherent WDM-PON using heterodyne detection with transmitter-side polarization diversity

Coherent detection can improve the receiver sensitivity and spectral density, so it has become a key technology in realizing the advanced access network. Adding optical heterodyne detection to the wavelength division multiplexing passive optical network (WDM-PON) makes it possible to increase the number of accommodated optical network units (ONUs) and the transmission distance. In this letter, we propose and demonstrate a heterodyne detection scheme that realizes polarization diversity with one photo detector and one receiving circuit by centralizing diversity devices at the transmitter. We experimentally achieved the cost-effective polarization diversity technique which receiver sensitivity fluctuation was 1.2 dB, and the power penalty was less than 0.8 dB after transmission through 10 km single-mode fiber.