Electromagnetic localized structures in a relativistic laser-plasma interaction

Localized electromagnetic structures with trapped laser light inside are often found in simulations of relativistic laser-plasmas. First, we examine existence and stability of onedimensional electromagnetic solitons formed in a relativistic laser interaction with an underdense cold plasma. In a weakly relativistic model, the original equation of the nonlinear Schrodinger type, with local and non-local cubic nonlinearities is derived. Standing electromagnetic solitons are analytically shown to be stable in agreement with the model simulation. Next, we discuss a novel example of a stimulated backscattering of a laser light from the slow trapped electron-acoustic wave, involving a standing (localized) Stokes light sideband. Conditions are examined when above underdense instability dominates over standard stimulated Raman backscattering.