Advanced smart multifunctional laser crystals for next generation solid-state lasers

The hydrothermal crystal growth technique is developed for the growth of epitaxial single crystal layers on YAG. High quality epitaxial layers of functionalized layers can be grown using Y2O3 doped with the desired ion and Al2O3 as feedstocks in water between 600-650 degrees C at 1 kbar pressure, with a mineralizer of 1-4M K2CO3. The epitaxial layers are doped with a variety of doping ions that enable a number of optical functionalities. These include undoped regions to serve as endcaps, Q-switching regions, ASE suppression cladding layers, waveguide layers and a number of other applications. Different layers can be grown sequentially on the same crystal to create multifunctional single crystals. Epitaxial layers have been grown on both {111} and {100} faces with rates of growth being {100}>{111}>{110}. Growth rates range typically from 25 to 100 microns per day but faster and slower rates have been observed. The technique is not restricted to YAG and can be extended to any oxide hosts that can be grown hydrothermally. Work is being extended to LuAG, YVO4 and M2O3 (M = Lu, Sc). The techniques presented here can address long-standing performance issues associated with solid-state laser materials; when combined with crystal joining technologies, new crystal functionalities emerge that can further improve solid-state laser performance; we refer to this new generation of laser crystals as "smart".