Abstract: This disclosure involves a new spinel and glass micro-composite material and process for making such. The composite has excellent transmission in the 0.5-5.0 ?m wavelength region suitable for various visible and mid IR applications utilizing windows, domes and other geometric shapes. The composite can be made at a temperature about 40% lower than the glass melting temperature and about 50% lower than the spinel sintering temperature. The composite material has high modulus and fracture toughness which are important for impact resistance in armor and other practical applications.

Abstract: A nanoparticle containing monoclinic lutetium oxide. A method of: dispersing a lutetium salt solution in a stream of oxygen gas to form droplets, and combusting the droplets to form nanoparticles containing lutetium oxide. The combustion occurs at a temperature sufficient to form monoclinic lutetium oxide in the nanoparticles.

Abstract: A method for reducing transmission losses in a spinel-based optical element by building a structure on the surface of the optical element without the use of a previously prepared master. The structure can be built through reactive ion etching (RIE) of a pattern obtained through photolithography and liftoff, through RIE of a pattern through e-beam writing and liftoff, through RIE of a pattern using a self organized metal mask, or by direct hot-pressing the structure during fabrication of the optical element. Also disclosed is the related spinel-based optical element made by this method.

Abstract: A method and apparatus for making a substantially void-free preform for a microstructured optical fiber using a one-step process is provided. A preform is prepared from specialty glasses using a direct extrusion method. A die for use with the direct extrusion method is also provided, and a method for drawing the preform into a HC-PBG fiber for use in transmitting infra-red wavelength light is also provided. The preform comprises an outer jacket made of solid glass, a cladding having a plurality of air holes arranged in a desired pattern within the jacket, and a core which is hollow.

Abstract: A method of forming a ?-SiC material or coating by mixing SiO2 with carbon and heating the mixture in vacuum wherein the carbon is oxidized to CO gas and reduces the SiO2 to SiO gas and reacting a carbon material with the SiO gas at a temperature in the range of 1300 to 1600° C. resulting in a SiC material or a SiC coating on a substrate. Also disclosed is the related SiC material or coating prepared by this method.

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 ?m, although the grains can also be smaller than 30 ?m. 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: This invention pertains to a process of bonding a magnesium aluminate spinel article or articles and a germanate glass article or articles including the step of heating them together above the softening temperature of the glass.

Abstract: The present invention is directed to a method for making infrared transmitting graded index optical elements by selecting at least two different infrared-transmitting materials, each with a different refractive index, having similar thermo-viscous behavior; assembling the infrared-transmitting materials into a stack comprising one or more layers of each infrared-transmitting material resulting in the stack having a graded index profile; and forming the stack into a desired shape. Also disclosed is the related optical element made by this method.

Abstract: Disclosed herein is a method for making transparent ceramic spinel windows, domes and other complex shapes via edge bonding.

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 ?m, although the grains can also be smaller than 30 ?m. 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 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 although the grains can also be smaller than 30 ?m. 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 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 ?m, although the grains can also be smaller than 30 ?m. 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 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 further provides 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 ?m, although the grains can also be smaller than 30 ?m. In a process for making a transparent polycrystalline ceramic in accordance with the present invention, 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 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: A functionally doped polycrystalline ceramic laser medium and method of making thereof are provided. The medium includes a solid state polycrystalline Ytterbium doped Yttria or Scandia (Yb:Y2O3 or Yb:Sc2O3) laser medium with a discrete or continuous gradient doping profile and methods for manufacturing the same. The doping profile can be two- or three-dimensional and can vary depending upon the laser geometry, the pumping scheme, and the benefits to be desired from the laser medium's structure. The grading direction can be linear, axial, radial, or any combination thereof. The material can be made from a combination of doped and undoped solid shapes, loose powders, and green shapes, and can be diffusion bonded or densified to a desired final shape using techniques such as pressureless sintering, hot pressing, hot forging, spark plasma sintering, and hot isostatic pressing (HIPing), or their combinations.

Abstract: A functionally doped polycrystalline ceramic laser medium and method of making thereof are provided. The medium includes a solid state polycrystalline Ytterbium doped Yttria or Scandia (Yb:Y2O3 or Yb:Sc2O3) laser medium with a discrete or continuous gradient doping profile and methods for manufacturing the same. The doping profile can be two- or three-dimensional and can vary depending upon the laser geometry, the pumping scheme, and the benefits to be desired from the laser medium's structure. The grading direction can be linear, axial, radial, or any combination thereof. The material can be made from a combination of doped and undoped solid shapes, loose powders, and green shapes, and can be diffusion bonded or densified to a desired final shape using techniques such as pressureless sintering, hot pressing, hot forging, spark plasma sintering, and hot isostatic pressing (HIPing), or their combinations.

Abstract: Particles including a YAG core and a coating of sintering aid deposited thereon. The particles and agglomerates thereof maybe formed as a powder. The coated YAG-containing particles are well-suited to production of polycrystalline YAG-containing ceramics. The coated YAG-containing particles may be fabricated using a novel fabrication method which avoids the need for formation of a homogeneous powder mixture of YAG and sintering aid. In the method, a solution including a sintering aid or sintering aid precursor is prepared and mixed with YAG-containing particles to form a mixture. The mixture may be sprayed into a drying column and dried to produce coated particles. Alternatively, the YAG particles and sintering aid or sintering aid precursor solution may be separately introduced to the drying column and dried to form coated YAG-containing particles.

Abstract: A ceramic having at least about 90% by weight magnesium aluminate and having a bulk scattering and absorption loss of less than about 1/cm at any wavelength in a range of about 0.23 to about 5.3 microns or 0.2/cm at any wavelength in a range of about 0.27 to about 4.5 microns. A method of making a ceramic by providing a plurality of particles having a magnesium aluminate core and a fluoride salt coating; heating the particles in an oxidizing atmosphere to a temperature in the range of about 400° C. to about 750° C.; and sintering the particles to form a solid ceramic.

Abstract: A ceramic having at least about 90% by weight magnesium aluminate and having a bulk scattering and absorption loss of less than about 1/cm at any wavelength in a range of about 0.23 to about 5.3 microns or 0.2/cm at any wavelength in a range of about 0.27 to about 4.5 microns. A method of making a ceramic by providing a plurality of particles having a magnesium aluminate core and a fluoride salt coating; heating the particles in an oxidizing atmosphere to a temperature in the range of about 400° C. to about 750° C.; and sintering the particles to form a solid ceramic.