The characteristics of a new high-gain photorefractive polymer composite with a PNP chromophore are investigated. Competition between beam fanning and two-wave coupling (TWC) is predicted and verified experimentally. The intensity dependence of TWC gain is studied. Higher diffraction order and forward phase conjugation in a TWC geometry are observed and explained.

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The characteristics ofphotorefractive polymer doped with PNP in optical image processing are investigated. PNP((S)-(-)-N-(5-thtro-2-pyridyl)prolinol ) is one of the high gain chromophore in polymeric photorefractive system. In the two wave coupling experiment, the gain coefficient about 180 is observed with 25 micron thick sample at 100V/jim. Higher diffraction order and phase conjugation is also observed. This photorefractive thin film is used as a holographic recording device. Fourier transform hologram is recorded by using similar arrangement of two wave coupling configuration. The reconstructed image from the photorefractive film is edge-enhanced. Degree of enhancement depends on the intensity ratio of signal to pump beam. Decreasing the ratio of signal to pump beam, degree of edge enhancement decreases. When the object pattern is defocused on the film, degree of enhancement also decreases. Optical image processing system in which degree of edge enhancement is controllable can be constructed.

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