Stability of one-dimensional relativistic laser plasma envelope solitons

Stability of one dimensional relativistic laser plasma envelope solitons formed by the nonlinear coupling of relativistically intense electromagnetic waves with plasma waves in a cold plasma to has been examined using fluid simulations. It is observed that the solutions for which scalar potential is weaker than the vector potential are stable whereas solutions with comparatively much higher scalar potential amplitudes are unstable. For unstable solutions, the instability mechanism has been identified as forward stimulated Raman scattering and the subsequent density bursts observed in the wake of the light field is understood in terms of phase mixing of nonlinear oscillations. For stable solutions, an interesting possibility opens up in their potential use as energy carriers through overdense plasma regions, which is an issue of crucial relevance to the fast ignition scheme of laser fusion.