OAM beam correction based on Gerchberg-saxton algorithm

In this research, the impact of ocean turbulence on vortex beams is explored, leading to the diffusion and distortion of their orbital angular momentum. The paper introduces a novel approach without the need for a wavefront sensor or a Gaussian beam as a probe. Instead, the Gerchberg-Saxton (GS) phase recovery algorithm is employed to correct the distorted beam, aiming to reduce the dispersion of the vortex beam and enhance communication performance. The GS algorithm utilizes multiple iterations of the input light intensity distribution to obtain the pre-phase. By analyzing the changes in the orbital angular momentum spectrum before and after correction, the algorithm effectively restores the purity of the beam. Additionally, the orthogonal nature of different orbital angular momentum in the vortex beam enables easy achievement of the multiplexing function. Experimental results demonstrate the successful correction of distorted vortex beams using the GS algorithm. Through phase correction, this technique improves the beam’s utilization, enhances its robustness, and minimizes transmission errors.