Characteristics of a Čerenkov laser improved by loading a kerr-like medium

Abstract

In the čerenkov laser, as the electromagnetic wave grows by gaining energy from the electron beam, it loses kinetic energy and, thus, its drift velocity decreases. As a result, the synchronism between the propagation velocity of the electromagnetic wave and the drift velocity of the electron beam ceases to be kept and efficient growth of the electromagnetic wave is prevented. to overcome this difficulty, this paper proposes a model for the čerenkov laser loaded with a Kerr-like medium, the permittivity of which increases in proportion to the square of electric field. Also, a numerical investigation is made to determine how the growth characteristics for the electromagnetic wave are improved with the aid of the finite element method. The numerical result shows that, by choosing a proper value for the nonlinear coefficient of the Kerr-like medium, the propagation velocity of the electromagnetic wave can be delayed in accordance with the decrease in the drift of the electron beam. Thus, the growth characteristics for the electromagnetic wave can be improved greatly. In addition, it is found that the interaction distance to maximize the electromagnetic wave power extracted from the electron beam can be shortened compared with the case where only a linear dielectric is loaded.