Dielectric function of an electron gas under intense laser radiation in quantizing magnetic fields

A detailed theoretical study on dielectric function of a three-dimensional electron gas (3DEG), subject to linearly polarized intense laser field and to strong static magnetic field, is presented. Using the Green’sfunction approach, I have derived the density-density correlation function and the random-phaseapproximation dielectric function for a 3DEG in t and representation. It is found that in the presence of intense terahertz laser field, the dielectric function of an electron gas depends strongly on frequency and intensity of the electromagnetic radiation. A number of important radiation effects, pertinent to the application of the free-electron laser sources developed recently, are presented and discussed.