Experimental analysis of light-polarization effects on Raman scattering intensity

Abstract

This work investigates how incident laser polarization affects Stokes-Raman scattering in a backscattered Raman spectroscopy setup. Using off-the-shelf, low-cost optical components, we experimentally demonstrate the polarization dependence of Raman signal intensity for crystalline silicon and black silicon. By switching between circular and rotated linear polarizations, the study shows how the visibility of specific vibrational modes can vary with respect to incident polarization. The results align with theoretical predictions and reveal stronger polarization sensitivity in crystalline silicon. These findings suggest a practical route toward non-invasive polarization-dependent characterization of thin films and surface-engineered materials. The normalized Raman intensities for the silicon peak exhibited variation across different linear polarization states for black silicon, corresponding to a 19.6% peak-to-peak modulation, while the c-Si exhibited a pronounced intensity variation representing a 75.6% peak-to-peak modulation.