A Novel Polarization-Multiplexing System for Free-Space Optical Links

In this letter, a novel polarization-multiplexing system for free-space optical links is proposed. Data is specially designed at the transmitter while received by coupling two lights in different states of polarization (SOP) after polarization rotation at the receiver. Based on this design, the closed form expression for bit-error-rate (BER) performance of the system is given. Our results indicate that polarization control error has no obvious influence on the system performance when it is less than 10
^°
. Performance of our system is superior to the traditional binary phase-shift keying (BPSK) scheme on overcoming phase fluctuation.