Study on the method and experiment of time-resolved coherent anti-Stokes Raman scattering using supercontinuum excitation

Abstract

In this paper, we present the development and experimental results of a time-resolved coherent anti-Stokes Raman scattering (CARS) experiment setup that is based on supercontinuum excitation and precise time-delay control. The output of a Ti-sapphire femtosecond laser is divided into two parts. One part is used to pump a photonic crystal fiber (PCF) to generate supercontinuum spectrum which is used as pump and stokes beams. The other part of the femtosecond laser is used as the probe light. Dimethyl sulfoxid, a sample with broad range of Raman spectrum was tested. Experimental results show that this system can inhibit the non-resonant background noise effectively and obtain CARS spectrum of dimethyl sulfoxide in the frequency range of 690—3200 cm-1 in one measurement, which means that spectrum range of the acquired CARS spectrum of dimethyl sulfoxide is 2500 cm-1. We also present experimental results of supercontinuum generation using a PCF.