The nonlinear diffraction property of a volume grating written by two-wave mixing in a cerium-doped potassium sodium strontium barium niobate crystal is applied in a coherent image processing system to obtain real-time image edge enhancement as well as edge-enhanced optical correlation. The theoretical analysis of the correlator is given, and the experimental results of optical correlation are presented, which are compared with the computer-simulated results.
Liang, B-L., Wang, Z-Q., Mu, G-G., Guan, J-H., Liu, H-L., & Cartwright, C. M. (2000). Real-time edge-enhanced optical correlation with a cerium-doped potassium sodium strontium barium niobate photorefractive crystal. Applied Optics, 39(17), 2925-2930. https://doi.org/10.1364/AO.39.002925