Abstract: Fused quartz containing both titanium dioxide and cerium oxide as UV absorbing dopants has been found to be particularly effective for lamp envelopes for high temperature lamps such as halogen-incandescent lamps and metal halide arc discharge lamps which emit both UV and visible light radiation. The codoped quartz transmits visible radiation and absorbs a substantial portion of the emitted UV radiation. The UV absorption is far superior at temperatures above 500.degree. C. and the codoped quartz does not react with the fill within.

Abstract: An all glass reflector having a front reflecting surface and terminating in the rear in a cavity into which a lamp is cemented transmits substantially less light out of the rear when at least the inside or the outside of the cavity and the reflecting surface are coated with an optical interference coating. The coating is applied by a low pressure chemical vapor deposition process.

Abstract: Thin film interference filters consisting of alternating layers of tantala and silica suitable for high temperature use on electric lamps have been made by heat treating at 550.degree.-675.degree. C. before using the filters at high temperature. Tungsten halogen lamps made with such heat treated filters have been thermally cycled for thousands of cycles at 900.degree. C. with no film loss and with satisfactory optical performance.

Abstract: A class of non-stoichiometric class of cerium and terbium co-activated magnesium aluminate phosphors is disclosed which are particularly useful in low pressure type fluorescent lamps. Said phosphor materials can be further combined with other phosphors to produce white color illumination in said type lamps. A general method for preparation of said phosphor materials is disclosed wherein the emission characteristics can be regulated to advantage.

Abstract: A class of non-stoichiometric class of cerium and terbium co-activated magnesium aluminate phosphors is disclosed which are particularly useful in low pressure type fluorescent lamps. Said phosphor materials can be further combined with other phosphors to produce white color illumination in said type lamps. A general method for preparation of said phosphor materials is disclosed wherein the emission characteristics can be regulated to advantage.

Abstract: Disclosed are a method and apparatus for forming a continuous length of glass article. A coating of glass particles is deposited on a mandrel having a thermal coefficient of expansion much greater than that of the glass particles. The mandrel is allowed to cool, thereby causing it to shrink and separate from the coating. The coating is indexed a discrete longitudinal distance along the mandrel, thereby uncovering a region of the mandrel. Another coating of glass particles is deposited on the uncovered region of the mandrel and over a portion of the previously applied coating. The steps of separating or freeing the coating from the mandrel, longitudinally indexing the coating with respect to the mandrel and depositing another coating are repeated. Thus, each step of indexing longitudinally translates an incremental length of a porous body from the end of the mandrel.