Abstract

Now light intensities above 10¹⁸W/cm² have been routinely achieved by focusing the ultrashort pulses delivered by compact multiterawatt laser systems. At these intensities, the quiver velocity of the electrons is relativistic, so that both the single- particle and collective response become nonlinear functions of the incident field. Recently, particle-in cell simulation method was employed for the study of ultrahigh intensity laser-matter interaction [1, 2] which has demonstrated complex unsteady dynamics of the interaction. Nevertheless, basic physical processes responsible for capability of the laser pulse to directly penetrate an overdense plasma were not identified. In this report, we describe and analyze certain basic process relevant to the ultrahigh intensity interaction of relativistic laser pulses with the sharply edged overdense plasma. Our analysis based on the hydrodynamics description of a plasma will consist of two parts. First, we consider a stationary model of reflection of circularly polarized laser wave normally incident upon a collisionless, overdense plasma.

© 1996 Optical Society of America