Lateral Wave on a Symmetrical Epstein Transition

Abstract

A theoretical investigation is made of a lateral wave on a diffuse interface. Half of a symmetrical Epstein layer is used as the transition between a free half-space and an underdense plasma region. An electric current line source is placed in the free-space region and an exact integral expression is obtained for the reflected field. A high-frequency asymptotic approximation, uniform with respect to transition thickness, is then obtained for the reflected field. This approximation consists of two terms. The first of these terms can be interpreted as a reflected wave for arbitrary transition thickness, while the second term can be interpreted as a lateral wave contribution when the wavelength is much greater than the transition thickness, and as a reflected wave when the wavelength is much smaller than transition thickness.