<title>Time and spatial dynamics of SRS amplitude-phase characteristics</title>

Abstract

The numerical model of stimulated Raman scattering (SRS) taking into account spatial dynamics of amplitude-phase characteristics and consisting of non-linear partial parabolic differential equations is developed. A fmite -difference numerical method was used to solve these equations. Results of simulation are in good agreement with experimental data. INTRODUCTIONStimulated Raman scattering in compressed gases can be effectively used to build lasers with frequency varying within wide range starting from ultra-violet up to infrared region. CW and pulsed lasers with nano-, piko-and femto-second pulse duration can be developed based on SRS nonlinearity. Spectral, spatio-temporal and power SRS characteristics contain information about scattering processes and nonlinear material. They are significant from practical and scientific points of view.The most important issue at SRS processes study is to define how radiation temporal characteristics evolve at radiation propagation in nonlinear material. These characteristics are intensity and phase time dependence, radiation spectrum. Actually the majority ofpublications about SRS are devoted to study oflisted above characteristics but spatial dynamics is also of interest as real sources radiation is limited in cross-section and is widening at radiation propagation in material. That is why we should consider diffraction effects at SRS generation study. Taking into account radiation intensity and phase variation in cross-section we can analyze such characteristics as spatial coherence function and spatio-temporal phase and intensity dependencies.