Abstract: Disclosed is a chemical polishing compound for silica based ceramics.

Abstract: An aluminum oxide-aluminum nitride composite electronic substrate with anisotropic thermal properties is described. The aluminum nitride is in the form of needles incorporated into the aluminum oxide, the needles being oriented or aligned through the thickness of the substrate parallel to the short transverse direction of the substrate. The substrate has improved thermal conductivity in the short transverse direction and yet maintains good dielectric strength across the surface of the substrate. The improved thermal conductivity is required for heat dissipation from the micropackage assembly.

Abstract: Optical waveguides are fabricated by heating a region of a body of flat filter glass with an energy beam such as a scanning focused laser beam. The region is locally heated to a temperature at which softening occurs. Upon cooling two differing effects occur, the two effects causing a "W" shaped index of refraction profile. The first effect is the photoelastic effect due to the residual stress introduced as the heated material cools and contracts. The residual tensile stress is constant in the softened region, but decreases as the distance from the center of the heating increases. Since the density and therefore the refractive index of this region is inversely proportional to the residual stress, this effect resulted in a local refractive index minimum. The other effect is the material density change in the softened region. As the cooling rate is small in the center and large in the edge of this softened region, a density change occurs with the center attaining the highest value and decrease towards the edge.

Abstract: A thin optical waveguide is formed by a waveguide region having an index of refraction greater than the index of refraction of the substrate. The greater index of refraction of the waveguide region is a result of residual stress within the waveguide region.

Abstract: Fine-grained polygonized halide bodies are formed having comparable optical properties to a single crystal halide body. Heat and force are applied to a single crystal halide to recrystallize or polygonize the halide. The body is then annealed to suppress room temperature grain growth.

Abstract: Fine-grained polygonized halide alloy bodies are formed having comparable optical properties to a single crystal halide body. Heat and force are applied to a single crystal halide to recrystallize or polygonize the halide. Room temperature grain growth observed in fine-grained pure halides is inhibited by alloying.