Abstract

It’s well known that the main mechanisms of holographic grating formation in photorefractive crystals are the diffusion of carriers, their drift in the electric field, and the photovoltaic effect (PVE). We shall concentrate on the last mechanism. It’s often supposed that the PVE in ferroelectrics can be characterized by the current along the polar $\overrightarrow{\text{c}}$-axis, j=α G I, where α is the absorption coefficient, G: the Glass coefficient, I: the light intensity. In this case, the PVE effect is analogous to the effect of supplementary electric field E_ph=j(σ_d+σ_ph)⁻¹, where σ_d, σ_ph are dark- and photoconductivity. The photoinduced field E_ph reaohes 10⁵ v/cm in LiNbO₃ and LiTaO₃. However, the effect of the PVE does not come to longitudinal current.

© 1990 Optical Society of America