Cross-focusing of Extraordinary and Ordinary Modes in a Magnetoplasma

Abstract

Abstract This paper presents an investigation of the self-focusing of a high power electromagnetic beam in a plasma/semiconductor in the presence of a static magnetic field when the extraordinary and ordinary modes are present simultaneously. The non-uniform heating and consequent redistribution of carriers by the Gaussian beam has been taken as the source of non-linearity in the plasma and parabolic semiconductor (e.g. Ge). In the non-parabolic semiconductor (e.g. n -InSb) the dependence of an effective electron mass on temperature has been taken as the mechanism of non-linearity. The non-linearity leads to the mutual coupling of the two modes; they support the self-focusing of each other. In a particular case where one mode is weak and the second is propagating in a self-made uniform waveguide, the weak mode propagates in an oscillatory waveguide. When both the modes have initially equal intensity, the rates of self-focusing of the two modes are different and this leads to the beam being elliptically polarized. It has also been seen that in the presence of coupling of the two modes ellipticity is increased approximately three times more than without coupling at a distance of Z = 1·2 Rd+ on the axis of the beam in a plasma for the typical parameters. The phenomenon of Faraday rotation is unaffected by the self-focusing.