A new device geometry and beam arrangement for a photorefractive effect based on a reflection type grating is proposed. Expansion of the grating spacing was accomplished by the introduction of the beam coupling prisms with lower reflection loss. Highly efficient improvement was achieved compared to the conventional reflection geometry in the two-beam coupling performance. An optical gain of 66 cm<sup>-1</sup> and a response time of 0.45 second were obtained with an external field of 25 V/µm using a conventional low glass transition temperature polymer system.
© 2003 Optical Society of America