Yttrium scandium gallium garnet laser with a waveguide element activated with Cr3+, Nd3+

A description is given of a waveguide active element made from an optically dense medium in the form of an yttrium scandium gallium garnet crystal activated with chromium and neodymium. A solid-state laser utilizing this active element emitted an average power of approximately 70 W with a divergence of 8' at a pump pulse repetition frequency of up to 35 Hz and an absolute lasing efficiency of 1.7%. An absolute lasing efficiency of 2.5% was obtained in the single-pulse regime using an illumination enclosure specially designed for a plate made of an optically dense active medium.