Abstract

We have observed in certain LiNbO₃ samples that the diffraction efficiency of sufficiently strong volume holograms may increase substantially before eventually decaying when illuminated with a uniform, non-Bragg matched beam. Such an increase is not predicted by the single trap version of Kuktarev’s band transport equations, nor can it be attributed to two wave mixing effects. We believe that the increase is due to the presence of multiple photo-active species in the crystal. In this paper we describe our experimental results and attempt to explain them using a multiple trap band transport theory. Such a theory was first described by Valley [1]. Our analysis differs from [1] in the assumed initial conditions. Specifically, we assume, and observe experimentally, that the temporal derivative of the space charge field is positive at the beginning of the erasure process. We also consider the implications of this effect for multiple hologram storage and adaptive holography.

© 1990 Optical Society of America