Mitigating the ambiguity problem in the CNN-based wavefront correction

Summary: This paper proposes a defocus measurement aided adaptive optics technique for turbulence compensation in an underwater wireless optical communication system, aiming to enhance the physical layer security. The technique utilizes a phase retrieval algorithm and probe beam to reconstruct the phase of distorted OAM beams, and introduces the mixture generalized gamma-Johnson SR distribution to characterize the probability density function of reference-channel irradiance. The potential advantages of this technique in improving the security performance in underwater optical communication are highlighted.