Abstract

We report the performance of photorefractive polymers that have improved response time and phase stability. The polymers studied consist of a host polymer, an attached nonlinear optical moiety, plus a hole transport agent, similar to those previously reported.¹ One such composition consists of the host polymer Bisphenol-A with the moiety 4′-amino-4′-nitrostilbene and the hole transport agent diethyl-aminobenzaldehyde-diphenyl hydrazone. Samples 145 μm thick exhibit a diffraction efficiency of 0.01% and an exponential response time constant of 0.1 s with an applied field of 90 kV/cm at a wavelength of 650 nm, 1.6 μm grating spacing, and an intensity of 0.3 W/cm². These results represent a 1,000-fold improvement in sensitivity (at comparable absorbance) over the results reported in Ref. ¹. There is no observable decrease in the photorefractive or photoconductive sensitivities of a sample stored 20 days at room temperature. This is also the first report, to our knowledge, of photorefractivity in a non-cross-linking electro-optic polymer. We also discuss the influence of the polymer composition, polymer processing, and experimental conditions on photorefractive performance and comparison with direct measurements of electro-optic and photorefractive response.

© 1992 Optical Society of America