A COMPACT CHERENKOV LASER WITH A BRAGG CAVITY COMPOSED OF DIELECTRIC GRATINGS

The growth and saturation characteristics of a Cherenkov laser with a Bragg cavity composed of dielectric gratings are investigated in detai l with the aid of numerical simulation based upon the fluid model of t he electron beam. For the analysis of the problem, a two-dimensional ( 2-D) model of the Cherenkov laser is considered which consists of a pl anar relativistic electron beam and a parallel plate waveguide, one pl ate of which is loaded with a dielectric sheet. For confinement and ex traction of the electromagnetic wave, a Bragg cavity is formed by diel ectric gratings fabricated at both ends of a dielectric-loaded paralle l plate waveguide. The result of numerical simulation shows that a com pact Cherenkov laser, the longitudinal dimension of which is about one order of magnitude smaller than that of the corresponding single-pass Cherenkov laser, can be realized by using a Bragg cavity composed of dielectric gratings.