Growth characteristics of a Cherenkov laser filled with inhomogeneous and collisional plasma

With the aid of the multilayer approximation method, the growth characteristics of a two-dimensional Cherenkov laser filled with transversely inhomogeneous and collisional background plasma at millimeter wavelengths are investigated. The accuracy of numerical results is confirmed by comparison with the available analytical solution. We show that the injection of a dense plasma into the background of a Cherenkov laser improves the beam-wave coupling and growth characteristics. Degradation due to electron-ion collisions in background plasma can be kept at an acceptable level by appropriate choices of the plasma and beam parameters. From numerical results, we can identify the main parameter of the inhomogeneous background plasma which affects growth characteristics of a plasma-filled Cherenkov laser