Photorefractive properties of cobalt-doped strontium barium niobate crystals

The two-wave interaction (at lambda = 488 nm) in strontium barium niobate c rystals doped with cobalt ions (Co:SBN) was studied. The experimental depen dences of the gain coefficient on the grating period and of the grating res ponse time on the writing beam intensity were used to calculate the Debye s creening length, the diffusion length, the dark conductivity, and the effec tive concentration of carrier traps for a series of Co:SBN crystals with di fferent dopant concentrations. The crystals were shown to have high couplin g coefficients (Gamma = 33 cm(-1)) and short optical response times (tau = 140 ms for I = 1 W cm(-2)). This, in combination with a high photorefractiv e sensitivity (S = 39 cm(2) J(-1)), determines the efficiency of their use in the storage of optical information and in laser phase conjugation.