A High bandwidth underwater wireless optical communication system

In this work, we present a high bandwidth underwater wireless optical communication system. Based on second harmonic generation theory of periodically poled lithium niobate (PPLN) crystal, a high-speed modulated laser source of 532 nm was obtained from a 1064 nm continuous-wave laser diode that was modulated at high speed, and then the frequency is doubled in PPLN. The average bit error rate (BER) of system is analyzed and simulated on the basis of BPSK, QPSK and 16QAM modulation under Gamma-Gamma ocean turbulence channel. Numerical analysis and simulation show that the communication performance degrade as the intensity of ocean turbulence increases, the average bit error rate (BER) performance of BPSK modulation is better than QPSK and 16QAM modulation, which is less affected by turbulence and has better anti-turbulence ability.