Simultaneous holographic and photocurrent studies of the photorefractive effect in LiTaO3and LiNbO3

摘要

In reduced LiNbO3thinsp;:thinsp;Mn both the photorefractive sensitivity and the simultaneously measured photocurrent result from drift with a polarizationhyphen;dependent effective rsquo;rsquo;internal fieldrsquo;rsquo; of about 6 kV/cm. In reduced undoped LiTaO3the observed difference in applied fields of the minimum photorefractive sensitivity and zero photocurrent imply charge transport is by a mechanism that cannot be completely described by diffusion and drift in an electric field. The direct measurement of the harmonic content of phase gratings written in several LiNbO3and LiTaO3crystals shows termination of chargehyphen;transport results from the spacehyphen;charge field of the hologram.