Hyper-resolution Brillouin–Rayleigh spectroscopy with an optical beating technique.

A system of optical beating spectroscopy has been newly developed for hyper-resolution Brillouin scattering. Frequency resolution as high as 1 kHz was obtained, far beyond the limit of the classical Fabry-Perot interferometer which is commonly used in ordinary experiments. This system is useful over the frequency range from 10[sup 4] to 10[sup 9] Hz at present. Experiments for Rayleigh and/or Brillouin spectra were performed in water, toulene, and carbon disulfide to demonstrate the performance of this system. [ABSTRACT FROM AUTHOR]