Fine structure of stimulated Brillouin components of the scattering in quartz and substances containing an absorber

A sensitive (high-resolution) method for investigating stimulated Rayleigh scattering was developed and tested. The method provided a considerable enhancement of the Rayleigh components without distortion of the spectral profile in a laser with a ring resonator. An external signal established traveling-wave conditions in this laser. The stimulated scattered light was the second external signal which acted on this laser. An anomalous shift of the stimulated Brillouin component was observed for substances with an absorber and this shift was correlated with the sign of the temperature coefficient of the hypersound velocity. The example of quartz was used to demonstrate the potentialities of this method in recording the fine structure of the stimulated Brillouin scattering in crystals. Preliminary investigations were made of the stimulated Brillouin emission in a passive ring resonator, which was coaxial with the pump beam.