Compact light source for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy

A compact light source module for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy was developed. It mainly consists of a nanosecond microchip laser, a photonic crystal fiber for Stokes light generation, and a single mode polarization maintaining fiber for pump light propagation. It is alignment-free and relatively low-cost compared with previous light sources of CARS microscopy. By using an assembled module, we successfully observed an ultrabroadband CARS spectrum and a CARS image of a murine adipocyte. The module is expected to greatly spread the CARS microscopy to various fields by its extreme easiness to handle.