Speed of the photorefractive effect in a BaTiO₃ single crystal

Authors

• Stephen Ducharme, University of NebraskaFollow
• Jack Feinberg, University of Southern California - Los Angeles

Document Type

Article

Date of this Version

August 1984

Comments

Published by American Institute of Physics.J. of Applied Physics 56, 839 (1984). ©1984 American Institute of Physics. Permission to use. Journal home page = http://jap.aip.org/jap/.

Abstract

We present data on the speed of light-induced refractive index changes in a BaTiO₃ single crystal. The light-induced erasure rate of a refractive index grating is shown to depend on optical intensity as I ^x where x<1. The exponent x depends weakly on temperature and increases from 0.62±0.02 to 0.71±0.02 when the temperature is varied between 12 and 40 °C. The sublinear dependence of rate on intensity implies that higher optical intensity is required to achieve high-speed operation of BaTiO₃ devices than previously thought. The dark erasure rate has an anomolously strong temperature dependence; it increases by a factor of 50 over the same temperature range. We have also determined that the number density of photorefractive charge carriers is 6×10¹⁶ cm^-3 in this crystal.