Abstract: An optical fiber comprising non-silica, specialty glass that has multiple fiber cores arranged in a square registered array. The fiber cores are “registered” meaning that the array location of any fiber core is constant throughout the entire length of the fiber, including both ends. Optical fiber bundles are fabricated by combining multiple multi-core IR fibers with square-registration. Also disclosed is the related method for making the optical fiber.

Abstract: Method of Making 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. 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 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: Monodisperse metal oxide nanopowders are prepared by treating a dispersion of crude metal oxide nanopowder with ultrasonication, allowing the dispersion to settle, and subjecting the remaining suspended portion to centrifugation to obtain a supernatant comprising metal oxide nanopowder.

Abstract: A method of generating ultrashort pulses with wavelengths greater than 2 ?m comprising a short pulse diode laser or fiber laser operating at a wavelength of 1 ?m or greater with a pulse width of 10 ps or greater, one or more amplification stages to increase the peak power of the pulsed source, a nonlinear fiber stage whereby the dispersion of the nonlinear fiber is anomalous at the pulsed source wavelength such that the fiber breaks up the pulse into a series of sub-ps pulse train through modulation instability which may be seeded by spontaneous noise which are then wavelength shifted in one or more stages by soliton self frequency shift in anomalous dispersion fiber or Raman in normal dispersion fiber and amplified in one or more stages to generate a high peak power ultrashort pulse (<1 ps) source at a wavelength of 2.4 ?m or greater.

Abstract: A method of generating a supercontinuum in chalcogenide fiber with a pump light comprising a short pulse fiber laser or diode laser operating with a wavelength of 1.0 ?m or greater that is wavelength shifted through a nonlinear fiber one or more times and amplified one or more times and launched into a chalcogenide fiber whereby the spectrum is broadened in the chalcogenide fiber through various nonlinear processes to generate a supercontinuum within the mid-IR from 1.5 to greater than 5 ?m.

Abstract: A method for making a smooth ceramic including loading ceramic powder to be densified into a hot press die, placing one or more spacers with a polished surface between a hot press punch and the ceramic powder, placing the die and punch into a hot press and hot pressing the ceramic powder, and removing a smooth ceramic shape that requires no subsequent polishing or processing and has a surface roughness of 5 nm RMS or better. The smooth ceramic shape may be transparent, and it may be spinel, magnesia, yttria, lutetia, scandia, YAG, any composites thereof, or any of their rare earth doped compounds. Also disclosed is the related smooth ceramic made by this process.

Abstract: An optical system having two or more different optical elements with a corresponding interface between the optical elements. At least one of the optical elements has an anti-reflective structure that is transferred to the interface between two optical elements, typically by embossing. Also disclosed is the related method for making the optical system.

Abstract: A laser apparatus uses a dysprosium doped chalcogenide glass fiber. The glass fiber has a laser pump operatively connected to it. The chalcogenide glass fiber is located in a laser cavity including one or more reflective elements such as a Bragg grating, a Bragg minor, a grating, and a non-doped fiber end face. The apparatus provides laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m at a useful power level using laser light input at a wavelength of from about 1.7 ?m to about 1.8 ?m. Also disclosed is a method for providing laser light output at a wavelength of about 4.3 ?m to about 5.0 ?m using the apparatus of the invention.

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: The present invention is generally directed to a method of making chalcogenide glasses including holding the melt in a vertical furnace to promote homogenization and mixing; slow cooling the melt at less than 10° C. per minute; and sequentially quenching the melt from the top down in a controlled manner. Additionally, the present invention provides for the materials produced by such method. The present invention is also directed to a process for removing oxygen and hydrogen impurities from chalcogenide glass components using dynamic distillation.

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: This invention pertains to a composite of AlON and a germanate glass, and to a process for bonding AlON to the glass. The composite includes AlON and 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 glass, the composite having excellent, i.e., typically in excess of about 60%, transmission in the 0.4-5 wavelength region.