Nonlinear Gaussian expansions of stochastic processes: super-Gaussian effects in coherent anti-Stokes Raman spectroscopy

We propose a new approach to the analysis of stochastic processes (such as fluctuating laser fields) with super-Gaussian statistics: the expansion of stochastic processes in terms of first and higher powers of Gaussian components, which are used like a basis set. This approach is applied to treat the super-Gaussian correlation effects observed in coherent anti-Stokes Raman scattering experiments using frequency-doubled pump laser fields. Our results give much better agreement with experimental data than previous theories do.