Abstract

The results of the experimental investigation and theoretical analysis of a reflection holographic grating in BTO crystals are presented. We have observed the growth of both light-induced absorption and reflection grating in the (100) and the (111) cuts of this crystal. The analysis of coupled-wave equations taking into account the pump depletion, the light absorption and the vector nature of interacting waves in an optically active cubic crystal is carried out. It is shown that in the case of linear polarization the scalar approach to the wave-coupling on the reflection grating with using a corrective multiplier for exponential gain coefficient is a good approximation for a thin crystal with small rotatory power. On the basis of these vector and scalar models we have estimated from experimental data the magnitude of the exponential gain coefficient on the diffusion gratings and the additional light-induced absorption in different BTO samples. A steady- state exponential gain coefficient depends on the pump intensity. The peak magnitude of the gain attainable in the (100) cut for some samples was estimated as Γ=4.7 1/cm. The additional light-induced absorption riches the value of δA=0.8 1/cm. The dark decay of a created reflection grating in the investigated samples continued for several days.

© 2001 Optical Society of America