Photochemical preparation of photorefractive polymeric media

The feasibility of photochemical formation of an image with photorefractive properties in polymer layers was shown. In layers composed of polyhydroxya minoether and tetrabromomethane, photochemical reactions resulted in the fo rmation of a polycationic chromophore of the Michler's hydrol type with opt ical absorption at 600-700 nm. The chromophore provides the polymer layers with photovoltaic sensitivity in the red region, second-order nonlinear opt ical properties, and the photorefractivity produced by two intersecting 647 -nm laser beams. The photorefractive effect at different intensity ratios o f writing beams (I-1/I-2) in layers differing in their exposure was evaluat ed. A relative gain in intensity of beam 2 at the expense of the loss in th at of beam I was 1.04-1.06 at I-1/I-2 =1 and increased to 1.32 as I-2 decre ased down to I-1/I-2 = 22 The photorefractive effect was compared with that in PEO-PMMA layers doped with a dye having a nonlinear optical properties and with molecules responsible for hole transport.