Spatial filtering, spectral matched inhibition, and recovering of defocused images are implemented by modulation of the induced birefringence of a BSO crystal. The intensity distribution received by the crystal modulates the induced birefringence and the ellipticity of the transmitted light is then modified as it propagates through the crystal. To describe the processor, a 4-f optical system is used. A simple physical model is introduced and numerical and experimental results are presented.
