Nounlinear pro pagation of an ultrashort laser pulse in titanium sapphire

Abstract

Wave propagation in dispersive nonlinear media has become a topic of intense research activities, in part stimulated by its potential application to optical fiber communication systems. Propagation of optical pulses in Titanium Sapphire is mainly influenced by the group velocity dispersion and the refractive index nonlinearity. Rapid progress in ultra short time laser technology has made it possible that optical pulses with durations comparable to the carrier oscillation cycle can be generated. The propagation of such ultra short and intense pulses is then affected by additional physical mechanisms, where especially higher order effects become important. Highly nonlinear operating conditions or the interplay between the different linear and nonlinear effects can result in dramatic changes of the temporal and spectral properties of the pulse. The propagation of an ultra short pulse is governed by a generalized nonlinear Schrödinger equation (NLSE), which can be derived from the underlying Maxwell equations within the slowly varying envelope approximation. We solve numerically a generalized Schrodinger equation by using a split step Fourier method. Effects such as the impacts of group velocity dispersion (GVD), third order dispersion (TOD), self phase modulation (SPM), wave breaking (WB), self steepening (SS), and intrapulse stimulated Raman scattering (ISRS) are demonstrated in detail. Examples for the above effects are demonstrated, as well as their interplay in the context of soliton propagation. The numerical method therefore presents an advantage tool for describing the ultra short pulse laser propagation in Titanium sapphir