Compact and fully collinear light source for broadband multiplex CARS microscopy covering the fingerprint region.

Compact and fully collinear light source for multiplex coherent anti-Stokes Raman scattering (CARS) microscopy was proposed and demonstrated. It consists of only a microchip laser, a short photonic crystal fiber, and a longpass filter. It offers performance of sensitivity, bandwidth, and spectral resolution suitable for biomedical applications, especially covering the entire fingerprint region (500-1800 cm−1). It can be readily implemented by a commercially available microchip laser and a photonic crystal fiber. It has great potential to expand the utility of CARS microscopy to a wide variety of fields such as endoscopy.