Methods for controlling of the laser-induced absorption in a BTO crystal by using of cw-laser radiation

Abstract

A photorefractive BTO crystal is exposed with cw-laser beams (430 mW/cm2 at 514 nm), and the photoinduced absorption between 480 and 900 nm is studied. A method of controlling this absorption by low intensity laser radiation of “green” and “red” wavelengths is demonstrated. The physical mechanism can be explained by the redistribution of electrons on the long-lived energy levels into the forbidden band. Dynamical characteristics of the redistribution are estimated.