Multiplexed substrate-mode holograms

Abstract
We present a simplified model and experimental verification for multiplexed substrate-mode volume holograms. The analysis is based on coupled-wave theory for uncoupled S- and P-polarization states of the incident beam. The theory is used to investigate a practical situation with the reconstruction beam normally incident upon the substrate plane and the diffracted multimode beams propagating in orthogonal directions within the substrate. Model results are then used to optimize the performance of experimental holograms formed in dichromated gelatin. The resultant multiplexed grating splits the incident beam into four orthogonal beams with nearly equal intensities, for a total efficiency of 80%.