Picosecond nonlinear optics

The Dual Beam Picosecond Continuum Technique for Measurement of Short-Time-Scale Transmission Spectra

“…On the picosecond time scale, continuum (or "supercontinuum" as it was called by Alfano [1] and is often used in the literature) generation is the result of several nonlinear mechanisms. The frequency broadening is primarily a result of self-phase modulation, which is a modulation the beam induces on itself because of the nonlinear change in index of refraction of the material with electric field [3,4]. In addition, on the picosecond time scale there also will be other participating nonlinear mechanisms such as stimulated Raman scattering, and to a lesser extent four-photon parametric generation.…”