Fiber Supercontinuum Source for Broadband-CARS Microspectroscopy Based on a Dissipative Soliton Laser

Abstract

We propose and demonstrate a supercontinuum fiber laser source for broadband coherent anti-Stokes Raman scattering (BCARS) microspectroscopy, seeded by a Yb-doped dissipative soliton fiber laser. Smooth continuum Stokes pulses ranging from 1050 to 1312 nm at -20 dB bandwidth are generated in a highly nonlinear fiber from the compact fiber seed, and the corresponding pump pulses are obtained after a narrowband filter centered at 1036 nm. With this fiber laser source, we are able to obtain BCARS spectra in 700-1900 cm-1 spectral range simultaneously with resolution less than 10 cm-1, and show its application in analyzing complex mixture. We also demonstrate the capability of our system in chemical imaging by simultaneously obtaining two two-dimensional CARS images of retinoic acid crystal at Raman shifts of ~1574 and ~1162 cm-1, respectively.

Keywords

• Fiber lasers
• non-linear microscopy
• supercontinuum generation
• Raman spectroscopy