Methods for the determination of the parameters of an yttrium aluminum garnet crystal and investigation of the influence of these parameters on the laser radiation characteristics

A method is proposed for the determination of the efficiency of an yttrium aluminum garnet laser from the characteristics of its output radiation. It is shown that the product of the threshold energy and the maximum efficiency of a free-oscillation laser can be used to determine the concentration of active particles in a crystal and the energy capabilities of a Q-switched laser utilizing this crystal. A waveguide resonator was used to produce polarized radiation with an angular divergence close to the diffraction limit in one plane. The output power of a laser with this resonator was 30 W, which was the same as for a conventional Fabry–Perot resonator.