An analytical model for Rayleigh-Brillouin scattering spectra in gases

An analytical model for Rayleigh-Brillouin scattering (RBS) spectra of gases is developed and discussed in this paper. The well-recognized S6 and S7 models only have a numerical form and are complex to process in real applications; simple Gaussian models are imprecise and suffer from greater error. A new model (V3) based on the spectral line broadening theory and the Voigt profile is established. This model is easy to process as it has an analytical form, and it is proved to have good accordance with the S7 model. In addition, this model can separate the Rayleigh and Brillouin lines, and the measured Brillouin shift is proved to match theoretical values.