Wavefront aberration correction for laser propagating over water with a closed-loop adaptive optical system

Key features of wireless laser communication include: a high data rate, no requirement for transmission media, portable, free of electromagnetic interference, etc. These make wireless laser communication a promising method for communication between islands or terminals over sea. However, as laser propagates through the atmosphere over the sea, the wavefront of the laser beam is distorted by the atmospheric turbulence and the reliability of the communication system is degraded. A major difference between the atmosphere over sea and that in land is that the humidity over sea is higher than in land. Therefore this work investigates the influence of water vapor on the wavefront of a laser beam propagating over water in a simulated marine environment, and corrects the wavefront aberration by a closed-loop adaptive optical system. Experimental results show that the wavefront of the laser beam is distorted severely by the water vapor and the closed-loop adaptive optical system is able to correct the wavefront aberration efficiently.