Abstract:
A transparent polycrystalline ceramic having scattering and absorption loss less than 0.2/cm over a region comprising more than 95% of the originally densified shape and a process for fabricating the same by hot pressing. The ceramic can be any suitable ceramic such as yttria (Y2O3) or scandia (Sc2O3) and can have a doping level of from 0 to 20% and a grain size of greater than 30 μm, although the grains can also be smaller than 30 μm. Ceramic nanoparticles can be coated with a sintering aid to minimize direct contact of adjacent ceramic powder particles and then baked at high temperatures to remove impurities from the coated particles. The thus-coated particles can then be densified by hot pressing into the final ceramic product. The invention further provides a transparent polycrystalline ceramic solid-state laser material and a laser using the hot pressed polycrystalline ceramic.
Abstract:
A high purity nano-sized Yb3+ doped Y2O3 (Yb:Y2O3) ceramic powder with a narrow size distribution and without hard agglomerates is provided. Also provided is a process for manufacturing the same wherein water in the reaction bath is replaced by a non-water washing agent having little or no hydrogen bonding capability to inhibit the formation of hard agglomerates in the ceramic powder.
Abstract:
A method of preparing a fine powder of calcium lanthanoid sulfide is disclosed. The method includes spraying soluble calcium and lanthanoid salts into at least one precipitating solution to form a precipitate comprising insoluble calcium and lanthanoid salts, optionally, oxidizing the precipitate comprising insoluble calcium and lanthanoid salts, and sulfurizing the optionally oxidized precipitate to form a fine powder of calcium lanthanoid sulfide. An alternative method for forming the powder is by flame pyrolysis. The calcium lanthanoid sulfide powder produced by either method can have an impurity concentration of less than 100 ppm, a carbon concentration of less than 200 ppm, a BET surface area of at least 50 m2/g, and an average particle size of less than 100 nm.
Abstract:
Beam steering apparatus is presented having a Risley double-prism pair with first and second double-prisms disposed along an optical path, where one or more of the prisms are made from a chalcogenide glass material.
Abstract:
A method for forming a high purity, copper indium gallium selenide (CIGS) bulk material is disclosed. The method includes sealing precursor materials for forming the bulk material in a reaction vessel. The precursor materials include copper, at least one chalcogen selected from selenium, sulfur, and tellurium, and at least one element from group IIIA of the periodic table, which may be selected from gallium, indium, and aluminum. The sealed reaction vessel is heated to a temperature at which the precursor materials react to form the bulk material. The bulk material is cooled in the vessel to a temperature below the solidification temperature of the bulk material and opened to release the formed bulk material. A sputtering target formed by the method can have an oxygen content of 10 ppm by weight, or less.
Abstract:
A method and apparatus for forming a thin film of a copper indium gallium selenide (CIGS)-type material are disclosed. The method includes providing first and second targets in a common sputtering chamber. The first target includes a source of CIGS material, such as an approximately stoichiometric polycrystalline CIGS material, and the second target includes a chalcogen, such as selenium, sulfur, tellurium, or a combination of these elements. The second target provides an excess of chalcogen in the chamber. This can compensate, at least in part, for the loss of chalcogen from the CIGS-source in the first target, resulting in a thin film with a controlled stoichiometry which provides effective light absorption when used in a solar cell.
Abstract:
A chalcogenide multi-clad optical fiber having a core, a first cladding and one or more subsequent claddings including a chalcogenide glass. The optical fiber may be capable of transmitting visible and inferred light and may be used for a wide variety of semiconductor applications.
Abstract:
This invention pertains to a chalcogenide glass of low optical loss that can be on the order of 30 dB/km or lower, and to a process for preparing the chalcogenide glass. The process includes the steps of optionally preparing arsenic monochalcogenide precursor or the precursor can be provided beforehand; dynamically distilling the precursor in an open system under vacuum from a hot section to a cold section to purify same; homogenizing the precursor in a closed system so that it is of a uniform color; disposing the distilled or purified precursor and at least one chalcogenide element at a hot section of an open distillation system; dynamically distilling under vacuum in an open system so that the precursor and the at least one chalcogenide element are deposited at a cold section of the open system in a more purified state; homogenizing the precursor and the at least chalcogenide element in a closed system while converting the precursor and the at least one chalcogenide element from crystalline phase to glassy phase.
Abstract:
This invention pertains to a composite of Spinel and BGG glass substrates and to process for bonding Spinel to BGG glass. The composite includes a Spinel and a BGG glass bonded together and having transmission in the visible and mid-infrared wavelength region. The process includes the step of heating them together above the softening temperature of the BGG glass, the composite having excellent, i.e., typically in excess of about 80%, transmission in the 0.5-5 wavelength region.
Abstract:
This invention pertains to product and process. The product is a transparent product of a density in excess 99.5% comprising spinel and having uniform mechanical properties. The process pertains to fabrication of a transparent spinel product comprising the steps of dissolving a sintering aid in water to form a neutral sintering aid solution, adding a suitable additive to the sintering aid solution, applying the sintering aid solution to spinel particles to form a spinel dispersion, sub-dividing or atomizing the spinel dispersion to form droplets comprising one or more spinel particles coated with the final spinel solution, drying the droplets to form dried coated particles comprising one or more spinel particles coated with a dried layer of the sintering aid, and densifying the dried coated particles to form a transparent spinel product having, uniform optical and mechanical properties in absence of grains of exaggerated size.