Determination of a Raman shift laser power coefficient based on cross correlation

Abstract

This work presents a novel, to the best of our knowledge, cross correlation technique for determining the laser heating-induced Raman shift laser power coefficient ψ required for energy transport state-resolved Raman (ET-Raman) methods. The cross correlation method determines the measure of similarity between the experimental intensity data and a varying test Gaussian signal. By circumventing the errors inherent in any curve fittings, the cross correlation method quickly and accurately determines the location where the test Gaussian signal peak is most like the Raman peak, thereby revealing the peak location and ultimately the value of ψ. This method improves the reliability of optothermal Raman-based methods for micro/nanoscale thermal measurements and offers a robust approach to data processing through a global treatment of Raman spectra.