The photorefractive effect in undoped semi-insulating GaP was observed. GaP has a photorefractive sensitivity in the spectral region of 0.6 to 0.9 μm. The photorefractive center is the deep donor resulting from the P antisite defect. We measured the two-beam coupling gain coefficient and its time constant as functions of the grating period and the pumping intensity, using a 633-nm He–Ne laser. The maximum gain coefficient of 0.33 cm−1 was obtained at a grating period of 1.1 μm. The time constant, which depends on the grating period, was 3–20 msec at a pumping intensity of 30 mW/cm2.
© 1990 Optical Society of America
Original Manuscript: May 17, 1990
Manuscript Accepted: July 24, 1990
Published: November 1, 1990
K. Kuroda, Y. Okazaki, T. Shimura, H. Okamura, M. Chihara, M. Itoh, and I. Ogura, "Photorefractive effect in GaP," Opt. Lett. 15, 1197-1199 (1990)