Hot-pressed transparent ceramics and ceramic lasers

• Main Authors: BAYYA SHYAM S, AGGARWAL ISHWAR D, VILLALOBOS GUILLERMO R, SANGHERA JASBINDER S, KIM WOOHONG, SADOWSKI BRYAN
• Format: Patent
• Language: English
• Published: 02.10.2012
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; ARTIFICIAL STONE; BLASTING; CEMENTS; CERAMICS; CHEMISTRY; CINEMATOGRAPHY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; CONTACT LENSES; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTROGRAPHY; FREQUENCY-CHANGING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HOLOGRAPHY; LIGHTING; LIME, MAGNESIA; MECHANICAL ENGINEERING; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHOTOGRAPHY; PHYSICS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; REFRACTORIES; SLAG; SPECTACLES; SPRAYING OR ATOMISING IN GENERAL; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURESAS SPECTACLES; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; TREATMENT OF NATURAL STONE; WEAPONS

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.