Temperature-dependent photorefractive effects in Bi4Ti3O12

摘要

Abstract: Holographic recording and beam coupling have been realized in ferroelectric Bi$-4$/Ti$-3$/O$-12$/ crystals. Many interesting phenomena have been observed in this material, such as formation of multiple gratings, transient enhancement of diffraction efficiency during holographic recording with preillumination of the sample at low temperatures, and enhancement of diffraction during the readout process after a long recording time at room temperature. In this paper, photorefractive effects are studied in the temperature range from 80 K to 310 K. Light- induced absorption changes, dark decay of the gratings recorded with different writing beam intensities, and measurements of different activation energy levels show evidences which support the charge transport model of multiple trap centers in this material. !16