Abstract

Photorefractive gratings recorded in a crystal of BSO and illuminated by a frequency-doubled Nd:YAG laser (wavelength, 533 nm; pulse length, 7 ns) at grating spacings of 1–8 m are studied using applied fields up to 7 kV/cm. The gratings are probed by a Bragg matched beam from a He–Ne laser. It is found that the diffraction efficiency initially increases linearly with pulse energy, then it saturates at a value which is proportional to the square of the applied field and which increases with increasing grating spacing. The energy density required to saturate the efficiency decreases with increasing grating spacing. The theory is based on the equations of Kukhtarev et al.,¹ which are solved numerically using a Runge-Kutta-Merson integrating routine. The experimental results are in most cases in good agreement with the theoretical predictions.

© 1988 Optical Society of America