Using a direct variational technique involving elliptic Gaussian laser beam trial function, the combined effect of non-linearity and diffraction on wave propagation of optical beam in a homogeneous bulk Kerr-medium is presented. Particular emphasis is put on the variation of beam width and longitudinal phase delay with the distance of propagation. It is observed that no stationary self-trapping is possible. The regularized phase is also seen to be always negative.
Self-focusing is one of the key issues in laser plasma physics applications. Problems involving a multidimensional beam within an inhomogeneous plasma are difficult to handle. This paper presents the investigation of two-dimensional selffocusing of a laser beam in a plasma whose density n(r, z) is a function of radial as well as z coordinates. The nonlinear mechanism responsible for modification of the background density and the dielectric function is of ponderomotive type. A variational technique is used here for deriving the equations for the beam width and the longitudinal phase. It is observed numerically that an initially diffracting beam is accompanied by oscillatory self-focusing of the beam with distance of propagation. The effect of inhomogeneity scale lengths is also observed. The increase in L r (= L /L ⊥) results in oscillatory self-focusing and defocusing with distance of propagation. Furthermore, critical fields for self-trapping of a laser beam as a function of refraction, diffraction lengths and scale lengths of inhomogeneities are also evaluated. Lastly, whatever parameters are chosen, the phase is always negative.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.