Generation of radiation by single-pass lasing subject to photon reflection by the lateral surface of the active medium

A theoretical study is reported of the influence of reflection of photons by the lateral surface of the active medium on the generation of radiation in single-pass lasing due to a population-inversion-induced transition. The geometric-optics approximation is used in a numerical solution of the integral transport equation for the radiation flux density. The angular distributions of the photons emerging from an active element are calculated. An analytic model is proposed for the description of radiation in systems with reflection.