DIVERGENCE OF THE RADIATION FROM A SOLID- STATE LASER WITH A STABLE CAVITY AND WITH INTRACAVITY APERTURES

A modified matrix model is proposed for stable cavities with intracavi ty Gaussian apertures, which approximate real apertures. This model di ffers from the known ones by a better grounded approach to selection o f the Gaussian aperture parameters. Analytic relationships are derived for calculating the energy divergence angle of the output radiation a nd of the beam diameter at the output mirror position under multimode emission conditions. It is shown that the spatial characteristics of t he beam are determined by the aperture diameter and by the complex mag nification, which is an analogue of the geometric magnification used i n the description of unstable cavities. The calculated results are in good agreement with experimental data.