Inversion of Orbital-Angular-Momentum Light Field Based on a Diffuser

Recently, orbital angular momentum (OAM) beams have been applied in free space optical communication (FSOC) to build a high-capacity communication link. However, the light field information of OAM beam is difficult to be detected directly and quickly. Herein, this paper demonstrates a detector using speckle-correlation scattering matrix (SSM) imaging technology based on a diffuser and proposes a generalized hybrid input-output algorithm (GHIOA) for iterative optimization of the OAM inversion light field. As an application example, inversion of OAM field without reference light is realized employing SSM approach, by using the optical transmission matrix of strong scattering medium as a diffuser. The simulation results illustrate that the approach can improve the retrieval effect of OAM light field, when the sampling parameter is 4, and the average correlation rate of the inversion OAM filed is increased by about 200% after using GHIOA.