Analysis of Rayleigh-Brillouin spectral profiles and Brillouin shifts in nitrogen gas and air

Yong Ma, Hao Li, ZiYu Gu, Wim Ubachs, Yin Yu, Jun Huang, Bo Zhou, Yuanqing Wang, Kun Liang
2014 Optics Express  
On the basis of experimental Rayleigh-Brillouin scattering data in gaseous nitrogen and air, simulations are performed to describe the observed frequency profiles in analytical form. The experimental data pertain to a λ = 366 nm scattering wavelength, a 90° scattering angle, pressures of 1 and 3 bar, and temperatures in the range 250 -340 K. Two different models are used to represent the RB-profiles, to distinguish the RB-peaks, and to obtain the Brillouin shift associated with the acoustic
more » ... th the acoustic waves generated in a gaseous medium. Calculations in the framework of V3 and G3 models, exhibiting composite profiles of three distinct peaks of Voigt or Gaussian functions, are compared to observation. Fitting results show that the V3 model yields an improvement over the G3 model. This mathematical model provides an even better representation of the observed profiles than the Tenti S6 model, which is considered to be the optimum representation in terms of physical parameters. For the derivation of Brillouin shifts, both models perform well at high gas pressure, while at lower pressures, the V3 model yields a higher accuracy than the G3 model.
doi:10.1364/oe.22.002092 pmid:24515218 fatcat:fxxolwgnwvgzxmwniuiijhqgiq