Abstract: A technique for reducing the appearance of Newton's rings for a light emitting device is disclosed. The light emitting device comprises a scattering layer positioned contiguous with the inner surface of a cover substrate. Scattering the light reduces or eliminates the opportunity for constructive interference and as a result reduces or eliminates Newton's ring formation.

Abstract: Disclosed is a synthetic silica glass optical material having high resistance to optical damage by ultraviolet radiation in the ultraviolet wavelength range, particularly in the wavelength region of less than about 250 nm and particularly, exhibiting a low laser induced density change. The synthetic silica glass optical material of the present invention contains at least about 0.1 ppm of aluminum and H2 concentration levels greater than about 0.5×1017 molecules/cm2. Additionally, the synthetic silica optical material of the present invention exhibits an H2 to Al ratio of greater than about 1.2, as measured in ×1017/cm3 molecules H2 per ppm Al.

Abstract: Disclosed is a process for suppressing monovalent metal ion migration between inorganic materials by placing a barrier layer containing Al2O3 and SiO2 between the inorganic materials. Also disclosed is a process for making silica-containing body comprising a step of forming a barrier layer containing Al2O3 and SiO2 over the soot-receiving substrate before the laydown of the fused silica boule. The barrier layer is effective in suppressing monovalent metal ion, especially alkali metal ion, particularly sodium migration at elevated temperature. The processes are particularly useful in the production and working of HPFS® materials required of a very low alkali metal, especially sodium, concentration.

Abstract: A method for forming a substantially flat planar lightwave optical circuit which has a substantially flat planar silica substrate and a sintered glassy lightguiding layer over the silica substrate. The structure is given a post treatment at an elevated temperature for a time sufficient to flatten said structure and overcome any distortion caused by the difference in the coefficient of thermal expansion of the substrate and any glassy layers formed over the substrate. Alternatively, the silica substrate may be heated and presagged to a predetermined degree to compensate for distortion or warpage which will occur in later processing.

Abstract: This invention is directed to glass compositions particularly designed for use in rear projection tube applications. The glass compositions are essentially free from ZnO, PbO and other easily reducible metal oxides other than Sb.sub.2 O.sub.3 and are essentially colorless. The glasses exhibit essentially no browning discoloration upon being exposed to high voltage electrons, linear coefficients of thermal expansion (25.degree.-300.degree. C.) between about 97-100.times.10.sup.-7 .degree. C., annealing points not lower than about 475.degree. C., strain points not lower than about 440.degree. C., electrical resistivities expressed as Log R greater than 9 at 250.degree. C. and greater than 7 at 350.degree. C., and liquidus temperatures below about 1100.degree. C. The glass compositions consist essentially, expressed in terms of weight percent on the oxide basis, of______________________________________ SiO.sub.2 55-60 K.sub.2 O 5.75-10 Al.sub.2 O.sub.3 1-3 Na.sub.2 O + K.sub.2 O 10.5-14 ZrO.sub.2 0-3.5 K.sub.

Abstract: A cathode ray tube faceplate glass that is essentially free from fluorine and the oxides of lead arsenic and zirconium, exhibits linear X-radiation absorption coefficients of at least 28 cm.sup.-1 at a wavelength of 0.6 Angstroms and at least 8.5 cm.sup.-1 at 0.3 Angstroms, undergoes essentially no "browning" discoloration when subjected to high velocity electrons, has a viscosity at the internal liquidus of at least 100,000 poises (10,000 Pa.s), has a coefficient of thermal expansion (25.degree.-300.degree. C.) in the range of 97-100.times.10-7/.degree. C., has an annealing point not lower than about 500.degree. C. and a strain point not lower than about 455.degree. C., has an electrical resistivity expressed in log R, that is greater than 9 at 250.degree. C. and greater than 7 at 350.degree. C., the glass consisting essentially, expressed in terms of weight percent as oxide basis, of______________________________________ SiO.sub.2 60-65 SrO 8-12 Al.sub.2 O.sub.3 0-3 BaO 8-12 Na.sub.2 O 6.

Abstract: This invention relates to the production of opaque, beige-tinted glass-ceramic articles consisting essentially, in weight percent, of______________________________________ SiO.sub.2 66-70 TiO.sub.2 3.5-5.5 Al.sub.2 O.sub.3 16.5-19.5 CeO.sub.2 1.5-2.75 Li.sub.2 O 2-4 As.sub.2 O.sub.3 0-1.5 MgO 1-5 F 0-1.2 ZnO 0.5-2 ZrO.sub.2 0-2.5 Na.sub.