Abstract
A new three-laser phase-matching geometry for coherent anti-Stokes Raman scattering (CARS) is presented. This geometry, which uses two counterpropagating beams, is experimentally convenient and provides excellent spatial discrimination of the signal regardless of the magnitude of the Raman shift or the medium dispersion. Experiments in CS2 are found to be in agreement with the calculated results. Two other dispersion-insensitive geometries are also presented.