Demonstration of a Rayleigh–Brillouin scattering spectrometer with a high spectral resolution for rapid gas temperature detection

A novel, to the best of our knowledge, Rayleigh–Brillouin scattering (RBS) spectrometer based on a virtually imaged phased array (VIPA) with a high spectral resolution is proposed for rapid gas temperature detection. CO ₂ RBS spectra at gas pressure of 0.5–4 bar were acquired with a spectrum acquisition time of 10 s, and temperature inversion analysis was performed using TENTI S6 model. The root-mean-square error (RMSE) of the RBS profile fitting is less than 2.95%, and the maximum absolute error of temperature inversion is less than 2.45 K. Compared with traditional methods, this method has low RBS signal loss and short acquisition time without the frequency scanning process, which is more conducive to real-time detection applications.