HIGH PHOTOREFRACTIVE SENSITIVITY IN AN N-TYPE 45-DEGREES-CUT BATIO3 CRYSTAL

We report the beam-coupling properties of a cobalt-doped oxygen-reduced n-type barium titanate crystal in the 0-degrees and 45-degrees crystallographic orientations. Oxygen reduction improved the response time of the 0-degrees-cut crystal by a factor of approximately 4.5 without diminishing the beam-coupling gain. The 45-degrees-cut crystal has a peak gain of approximately 38.7 cm 1, a response time of approximately 21 ms, and a photorefractive sensitivity of 3.44 cm3/kJ. We infer from response time measurements an equivalent percentage change in the dc dielectric constant and the mobility with respect to crystallographic orientation.