Fitting of Brillouin Spectrum Based on LabVIEW

Abstract

The characteristics of Brillouin scattering spectrum has been analyzed. The nonlinear least square algorithm based on Levenberg-Marquardt has been researched. In view of the characteristics that Brillouin frequency spectrum shows a Lorentzian distribution, Lorentzian curve fitting was achieved based on Levenberg-Marquardt nonlinear least square algorithm in Lab VIEW, and the fitting results have been compared based on different initial coefficients, the result showed that the setting of initial value had enormous influence on the fitting result. And also simulation curve fitting of Brillouin spectrum has also been performed in MATLAB. Finally, comparison of both results showed that it will be more precise and more efficient to fit curve if combining Lab VIEW with MATLAB.