Communication Performance of OAM Based FSO System in Weak Turbulence Environment

The communication performance of orbital angular momentum (OAM) based free space communication in a weak atmospheric turbulence environment is experimentally studied in this paper. We use spatial light modulator (SLM) to generate +10th and +20th OAM beams, respectively, and high-speed communication with the communication rate of 28Gbit/s in each link is demonstrated. The turbulence channel used is based on the hot plate thermal convection principle, a weak, controllable turbulence environment. The experiment also compares the communication performance of traditional Gaussian beams and + 10th and +20th OAM beams. The experimental results show that in a weak turbulent environment, compared with Gaussian beam-based system, high order OAM beam-based system can reduce the scintillation index by 33% to be 0.27 and improve the detection sensitivity by 2.94dB to -21.93dBm.