Hybrid 2-color/3-color background-free broadband CARS with passive polarization optics

摘要

Broadband coherent anti-Stokes Raman scattering (B-CARS) in a hybrid 2-color/3-color excitation regime hasbeen shown to be a photon-eu000ecient method of generating CARS across the entire vibrational region of interest(fingerprint and C-H stretch). We extend here our spectral interferometric polarized CARS (SIP-CARS) approachto a hybrid 2-color/3-color excitation regime, demonstrate that the power/polarization dependence for both 2-color and 3-color excitation agrees with theory, explore the application of SIP-CARS for the special case ofanisotropic, birefringent materials (using collagen) and present in vivo lipid imaging of different mutations ofthe nematode Caenorhabditis elegans with modified lipid distributions. The extension of SIP-CARS to a hybridexcitation scheme makes possible a fast, all-optical and quantitative method for Raman imaging.