Raman wave front of higher-order Stokes and four-wave mixing processes

Abstract
By using Gaussian—Hermite-mode expansion, the Raman nonlinear wave equations for the second-order Stokes field generated in the processes of cascade Raman scattering and four-wave mixing are solved for the case of a pump with a focused Gaussian beam. The numerical analysis is made under tight and soft focusing cases, and the calculated results are compared with our recent experiment.