Polarization-insensitive single balanced photodiode coherent receiver for passive optical networks

Alamouti polarization-time block coding, combined with heterodyne detection, enables phase-diverse coherent detection using a single balanced photodiode without optical polarization tracking. A 10.7Gb/s OFDM signal is experimentally rotated over the full Poincare sphere achieving a mean receiver sensitivity of -35.8dBm.