摘要
Brillouin spectroscopy is a powerful tool for measuring the mechanical properties of materials without contact.The sensitivity to mechanical changes that a Brillouin spectrometer can detect is determined by the precision to which a spectral peak can be localized.The localization precision is however fundamentally limited by the low mumber of photons within a Brillouin measurement,as wel as by intrinsic noise of the setup.Here,we present a method to improve the spectral sensitivity of Brillouin measurements by exploiting the autocorelation function of the spectrum.We show that by performing a localization process on the autocorrelation function nearly 20%increase in localizat ion precision can be obtained.This result is consistent bet ween our theoretical treatment,numerical simulation and experimental results.We further study the efect of back-ground noise on the precision im provement for realistic scenarios.
