Abstract

Photorefractivity arises from the combined effects of photoconductivity and electro-optic response simultaneously present in a material,¹ Photoconductivity in organic and polymeric materials involves photocharge generation and charge-transporting processes.² We report the preparation of a new series of polymeric photorefractive composite materials based on bifunctional chromophores, i.e., molecules that serve as charge-transporting agents as well as second-order nonlinear-optical (NLO' chromophores. The structures of two chromophores are shown in Fig. 1. The charge-transporting properties stem from the triphenylamine moiety, and the second-order NLO response stems from the push-pull structure linked by difieren conjugation paths. These chromophores have been incorporated into poly-(n-butyl- methacrylate) (PBMA), which serves only as a binder. When sensitized by C₆₀, photorefractivity has been observed with higf diffraction efficiency, large net two-bearr coupling gains, and moderate responst times.

© 1995 Optical Society of America