摘要:
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.
摘要:
A method for making a rare earth doped polycrystalline ceramic laser gain medium by hot pressing a rare earth doped polycrystalline powder where the doping concentration is greater than 2% and up to 10% and where the grain size of the final ceramic is greater than 2 μm. The polycrystalline powder can be Lu2O3, Y2O3, or Sc2O3, and the rare earth dopant can be Yb3+, Er3+, Tm3+, or Ho3+. Also disclosed is the related rare earth doped polycrystalline ceramic laser gain medium prepared by this method.
摘要:
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.
摘要:
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.
摘要:
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 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.
摘要:
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.
摘要:
A method of forming a β-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.
摘要:
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 μm, although the grains can also be smaller than 30 μm. 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.
摘要:
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.
摘要:
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.