Influence of readout optical field variations on inner product calculation in volume holographic correlator

The volume holographic correlator (VHC) can be employed as a multichannel inner product calculator and has the potential in parallel and massive computing applications. The inner product calculation accuracy of the VHC varies with the optical illumination field in the plane of the spatial light modulator during readout. A theoretical model of the VHC is presented to study the influence of the optical field variations. The simulation results are shown to examine the cases of illumination angle deviation and wavelength deviation. The influences of hologram thickness on the calculation are also discussed. Experiments are carried out to investigate illumination angle deviation of the VHC. The presented method is helpful to improve the inner product calculation accuracy in the VHC for parallel optical image processing.