Interference cancellation analysis of output spectrum of virtual image phased array (VIPA) and application of VIPA in spontaneous Brillouin backscattering measurement

Abstract

Abstract This paper mainly introduced a virtual image phased array (VIPA)-based Brillouin spectroscopy technology, analysed VIPA in principle, deduced the Brillouin shift calculation equations, analysed the output spectral characteristics of VIPA through simulation, and proposed the most effective way to avoid interference cancellation in the spectrum. We built a single-stage VIPA spontaneous Brillouin backscattering system, and made multiple measurements on water, ethanol and glycerol, and the measurement results are consistent with the theoretical values reported in other literature. Finally, it is compared with another method mentioned in the literature, and the results show that the method in this paper has higher accuracy.