Low noise image amplification by contradirectional two-wave mixing in Rh-doped BaTiO/sub 3/ crystal

Summary form only given. Most of the research on the photorefractive image amplification in the past adopted the configuration of forward two-wave mixing (FTWM). However, the beam fanning effect, a kind of forward stimulated photorefractive scattering (SPS), usually leads the amplified image to a poor signal-to-noise ratio (SNR). We found contradirectional two-wave mixing (CTWM) can effectively remove the noise in the amplified image and can raise the gain. For comparison, both of the configurations of FTWM and CTWM were investigated in our experiment.