Influence of refraction losses on laser radiation characteristics

A method is developed for solving the self-consistent problem of lasers with internal losses due to the refraction of light in an optically inhomogeneous active medium. The dependences of the power, of the transverse distribution of the intensity, and of a factor representing refraction losses of laser radiation on the reflection coefficients of the resonator mirrors and on the relationship between the transverse profiles of the refractive index and pumping rate are obtained. An analysis is made of the special features of the behavior of the laser radiation characteristics on increase in the reflection coefficients of the resonator mirrors to unity and of the limiting characteristics of laser radiation when the reflection coefficient of the exit resonator mirror is close to zero. The new method is used to analyze the characteristics of the radiation emitted by iodine lasers pumped by ultraviolet radiation generated in high-current open discharges. It is shown that in these lasers an increase in the reflection coefficient of the resonator mirrors reduces the refraction loss factor.