The results of experimental investigation of a XeCl laser, in which a resonator formed by a concave mirror and a partially reflecting convex specular meniscus is used to decrease the output beam divergence, are presented.
It is shown that the optimal reflectance of the specular meniscus at magnification M = 10 equals 20% for this laser. Based on numerical calculations, it is concluded that this laser with a plane–parallel resonator, whose output mirror is a quartz plate, and with an unstable telescopic resonator at magnification M = 10 being formed by totally reflecting mirrors, operates under conditions of saturation. In the first case, the optimal reflectance of the output mirror is equal to 4.5%, and in the second case, the optimal magnification of the resonator is M = 22.