Supercontinuum fiber laser-based coherent anti-Stokes Raman scattering microscopy for label-free chemical imaging

Abstract

Coherent anti-Stokes Raman scattering (CARS) microscopy can resolve the chemical components and distribution of living biological systems in a label-free manner and is favored in several disciplines. Current CARS microscopes typically use bulky, high-performance solid-state lasers, which are expensive and sensitive to environmental changes. With their relatively low cost and environmental sensitivity, supercontinuum fiber (SF) lasers with a small footprint have found increasing use in biomedical applications. Upon these features, in this paper, we homebuilt a low-cost CARS microscope based on a SF laser module (scCARS microscope). This SF laser module is specially customized by adding a time-synchronized seed source channel to the SF laser to form a dual-channel output laser. The performance of the scCARS microscope is evaluated with dimethyl sulfoxide, whose results confirm a spatial resolution of better than 500[Formula: see text]nm and a detection sensitivity of millimolar concentrations. The dual-color imaging capability is further demonstrated by imaging different species of mixed microspheres. We finally explore the potential of our scCARS microscope by mapping lipid droplets in different cancer cells and corneal stromal lenses.