Polarimetric coherent anti-Stokes Raman scattering microscopy of collagen.

We demonstrate polarimetric coherent anti-Stokes Raman scattering (PCARS) microscopy for quantitative analysis of collagen orientation. Using polarization-modulated excitation and cross-polarized detection, we extract both chemical and orientational information from intact tissues. We introduce two complementary analyses: the CARS peak polarization ratio (PPR) and Fourier domain polarimetric analysis, providing a robust characterization of collagen organization. This method enables rapid, label-free imaging of a collagen structure with molecular specificity, offering what we believe to be new capabilities for studying collagen remodeling in biological processes.