Low-temperature dynamic properties of photorefractive grating in potassium-strontium-sodium-barium-niobate crystal

Abstract

The low-temperature dynamic properties of photorefractive gratings in cobalt-doped potassium-strontium-sodium-barium-niobate crystals are reported. At low temperatures, the photorefractive space-charge field undergoes quasiperiodic oscillations if the crystal is preilluminated by one of the writing beams. The write-erase cycle of the index grating becomes shorter if the crystal is preilluminated by one of the writing beams, which provides a means for crystal sensitization. The magnitude of the index grating decreases significantly at low temperatures. The temperature dependence of the dark decay of the photorefractive grating is measured to complete our study and demonstrate the multiple shallow levels existing in the crystal. A model of double carriers with multiple shallow levels is assumed to explain the experimental results. © 1999 American Institute of Physics.