Anisotropic self-focusing of intense lasers in undercritical plasma

A variational principle approach to study the anisotropic self-focusing of ultrarelativistic laser beams in the undercritical plasma is performed in this paper. The presence of the anisotropic self-focusing laser intensity profile is viewed as a result of unstabilization of the isotropic profile. The isotropic laser profile is solved and then its stability relative to the anisotropic one is discussed. Numerical results show that parameters of the isotropic profile are important for its possibility of anisotropic unstabilization.