Preparation and study of epitaxial Cr4+ : GGG films for passive Q switches in neodymium lasers

The efficient technology is developed for growing Cr- and Ca-doped gadolinium–gallium garnet single-crystal films of thickness up to 100 μm on large substrates (76 mm) by the method of liquid-phase epitaxy from a solution–melt. The dependences of the absorption spectra of films and optical losses at 1 μm on the growth conditions and the solution–melt composition are studied. It is shown that Cr⁴⁺ ions are formed in the films, and these films can be used as passive Q switches in lasers.