Inversion of orbital-angular-momentum light field based on strongly scattering medium

Orbital Angular Momentum (OAM) beam is a vortex beam with helical phase term. The OAM multiplexing can make the beam carry more information. However, in practical communication, the scattering effect of the channel may lead to the distortion of the phase of the optical field. In this paper, an optimal spectral method based on the scaling is proposed for the inversion of the scattered light field, and the BFGS algorithm is used to iteratively optimize the initialized retrieved light field. Simulation results show that when the sampling rate is 4, the correlation of optical field inversion increases to more than 0.9999. The inversion error is reduced by $10^{-10}$ times compared with the method combining the speckle-correlation scattering matrix (SSM) and Gerchberg-Saxton (GS) algorithm, achieving a high-fidelity phase recovery.