Abstract: The invention provides a means for preparing rare-earth-doped ?-(Al1-xGax)2O3 films by molecular beam epitaxy (MBE). The invention provides a composition of matter, rare-earth-doped ?-(Al1-xGax)2O3 films, and methods to provide thin films of this material. The invention also provides a means to prepare thin film rare-earth-doped ?-(Al1-xGax)2O3, including Nd: ?-(Al1-xGax)2O3, for use in solid state lasers. Rare-earth-doped ?-Ga2O3 and rare-earth-doped alloys of ?-Ga2O3 and ?-Al2O3 with the same single-crystal structure independent of Ga/Al ratio are disclosed herein.

Abstract: The present invention relates to the growth of single phase rare earth-doped sapphire (?-Al2O3) films on substrates by molecular beam epitaxy. The invention provides for composition of matters, neodymium-doped sapphire films, and methods for making and using thin films of this material. The rare earth-doped films of the present invention are especially useful in solid state lasers.

Abstract: The invention relates to methods of making optical waveguide structures by way of molecular beam epitaxy (MBE). The method comprises the steps of: (1) providing a single crystal substrate in an ultra-high vacuum (UHV) environment, wherein the single crystal substrate has a first index of refraction; (2) heating the single crystal substrate; (3) depositing an epitaxial oxide layer having a rare-earth dopant and a second index of refraction on the single crystal substrate, wherein the epitaxial oxide layer is deposited by way of at least first, second, and third molecular beam fluxes; and (4) depositing a cladding layer on the single crystal oxide layer, wherein the cladding layer has a third index of refraction that is the same or about the same as the first index of refraction of the single crystal substrate, and wherein the second index of refraction is greater than the first and third indexes of refraction.