Improved photorefractive response using a cylindrical lens

Abstract

It is well known that the photorefractive response time improves with incident laser intensity.1 This characteristic behavior can be exploited by focusing incident laser , light to a small waist in the photorefractive medium. Unfortunately, the use of a spherical lens to focus the incident beam to a tight waist may also result in a decrease in the magnitude of the photorefractive effect. We report on experimental observations which demonstrate that the photorefractive characteristic response time can be improved by more than an order of magnitude by using a cylindrical lens to focus the incident laser light into the photorefractive material. In particular, the photorefractive response time for two-beam coupling,1 beam fanning, and self-pumping2 are each observed to improve while maintaining approximately the original coupling strength.