Uncertainty estimation on frequency shift of Brillouin light scattering

Abstract

Better knowing the precision on the measured value of the Brillouin peak frequencies is essen-tial in order to use it to deduce parameters related to studied materials. Modern methods for evaluating uncertainties are based on the recommendations of the Guide to the expression of uncertainty in measurement. After checking the agreement between the measured 15.7 GHz shift on a Brillouin signal on Poly-(methyl methacrylate) and the expected value, the elementary un-certainty terms are evaluated in two groups, by statistical methods and by other means. We de-scribe the general principle of operation of Brillouin light scattering setup with a high power laser and evaluate the elementary terms of uncertainty, according to international standards en-acted for metrology. The global uncertainty on frequency shift is then calculated and we find +-1.20x10-2 at 2 {\sigma}.