Spatial differentiation of optical images using selective erasure of photorefractive holograms

초록

We propose and demonstrate a novel technique of spatial differentiation of optical images based on the selective erasure of holograms in photorefractive crystals using a composite filter which consists of an amplitude and a phase filter. The net filter is realized by controlling the modulation depth, amplitude of a photorefractive grating using a one-dimensional Gaussian erasing beam in conjunction with a phase filter in the reading beam's path. Experimental results are presented and compared with other type of filter.