Interaction between a weak scanned light wave and high-power pumping in a medium having cubic nonlinearity

The authors propose a new method of mismatching for a holographic grating produced by periodic weak-wave angular scanning. The formation of the grating itself is qualitatively altered and the amplification is accompanied by weak-radiation spectrum distortion. The amplification in a transparent medium is of threshold-free type, it is sensitive to the parameters of the medium and the radiation, and it can be substantial even for a comparatively small ratio of the relaxation time to the scanning period. The method appears to be of interest in the production of amplification for weak beams and in measuring the parameters of nonlinear media.