Simulation of wavefront optimization with volume Bragg grating in photothermorefractive glass

Optimization for the wavefront distortion based on volume Bragg gratings (VBGs) recorded in photothermorefractive glasses (PTR) is simulated. A beam with different wavefront distortions is the incident on VBGs at the Bragg angle. The wavefront distribution of diffracted beam through two orthogonal VBGs is simulated based on the angular spectrum theory and the coupled wave theory. Four VBGs with different angular selectivity are used to simulate and optimize the wavefront distribution. The simulation results show that the wavefront distribution can be optimized with the VBGs of suitable angular selectivity. The PV value and the RMS value can be improved. The far field quality of laser beams is optimized.