Two-dimensional diffraction calculations for a fast-flow CO laser

Conclusion We have developed, a two-dimensional diffractive model of a free-flow CO:N₂ laser, using a detailed kinetic model of the active medium.We have shown that the constant-gain model and the diffractive model yield practically the same calculated energy characteristics of a free-flow CO laser. Calculation of the spectral characteristics has shown that the diffractive model yield the same numbers and intensities of the rotational-vibrational transitions on the cavity axis as the model with constant gain. We have determined the errors incurred in calculations by the constant-gain model.At an active-medium density 0.25 Amagat the angular divergence of the radiation is determined by the large-scale inhomogeneity of the subsonic gas flow while the radiation directivity in the far zone is manifested by a noticeable angular shift and is split.Translated from Preprint IAE-5724/11, Kurchatov Institute of Atomic Energy, Moscow, 1990.