Theoretical and experimental investigations of a quasiwaveguide thin-film laser with a light-induced distributed feedback

The results are given of theoretical and experimental investigations of the conditions for self-excitation of a quasiwaveguide laser system with a light-induced distributed feedback. A theory of such feedback is developed for the system in question and calculations are made of the threshold and spectral–angular characteristics of lasing. A report is given of attainment of frequency-tunable single-mode and multimode lasing of a system with characteristics that agree with the results of the theoretical analysis.