Minimizing Polarization Multiplexing Angle in Polarization-Division-Multiplexed System

The minimization of polarization multiplexing angle in a polarization-division-multiplexed (PDM) transmission system is explored. An effective polarization demultiplexing algorithm based on Stokes space is proposed to realize the demultiplexing of two nonorthogonal polarization states. Both simulation and experimental results verify the effectiveness of the proposed algorithm for the transmission of a 56-Gb/s PDM-dual phase-shift keying (DPSK) signal over different polarization multiplexing angles (i.e., $\theta=23^{\circ}$ , 45°, 67°, 90°) and different lengths of transmission links (i.e., back-to-back, 320 km, 400 km).