Corning Incorporated

Other

Corning Glass Works

Gerald E Burke

Carlton Maurice Truesdale

Pushkar Tandon

Steven Bruce Dawes

Luis Alberto Zenteno

V Srikant

Christine L Hoaglin

Robert D DeLuca

Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine. Laser and induction methods and apparatus for forming the barrier layer are depicted. A chlorine, fluorine and silica precursor, such as chlorofluorosilane, may be utilized to form fluorinated soot. Other methods and apparatus are directed to combinations of conventional and substantially water-free processes. One embodiment is directed to combustion enhancing additives for addition to the substantially hydrogen-free fuels. The methods and apparatus in accordance with the invention are particularly useful for producing photomask substrates and optical fiber preforms.

Method of forming optical fiber preforms

An optical fiber with a non-circular cross-section is realized by creating a void having the desired cross-section in a housing and filling the void with an optical material. This structure is then collapsed to solidify it and drawn to desired dimensions. The optical material may be rods, soot or ground material.

Method for making fibers having cores with non-circular cross-sections

Disclosed is an optical waveguide fiber having a compressive outer layer that includes TiO,in the SiO,matrix glass. The compressive outer layer includes crystalline structures containing TiO,that are predominately rutile. Also disclosed is a method for making an optical waveguide fiber having a compressive outer layer. The compressive outer layer can contain an additional metal oxide that is preferentially lost from the outer layer, instead of the TiO,, during the drying and consolidation step.

Process for forming a titania-containing preform silica glass blank

A method for making an optical attenuating device comprising an optical waveguide having a core doped with a transition metal and a cladding. The transition metal is deposited in the core during a core blankmaking process. The transition metal doped core is exposed to gaseous hydrogen in a furnace to significantly increase the attenuation of the device.

Optical waveguide attenuating device and method for producing the same

A method for forming a GeO.sub.2 -doped SiO.sub.2 glass article by depositing glass particles to form a porous preform and then drying and sintering the porous preform. A precursor of SnO.sub.2 is also present in the reactant stream used to form the particles, whereby the reaction produces particles of glass that contain GeO.sub.2, SiO.sub.2 and SnO.sub.2. The presence of SnO.sub.2 in the particles reduces the reaction of GeO.sub.2 with chlorine to form GeCl.sub.4 during the drying step. The GeCl.sub.4 that would have formed would have either escaped from the porous preform or caused GeO.sub.2 to be re-deposited in an undesirable portion of the preform. The retention of GeO.sub.2 in the article is therefore enhanced.

Increasing the retention of Ge0.sub.2 during production of glass articles

There is disclosed a method and apparatus for providing optically pure glass blanks, tubing, crucibles and the like for use in forming optical waveguides, lenses, prisms, filters, lamp envelopes and the like. A glass layer is formed at a high temperature on a mandrel which includes a support rod or tube upon which is disposed a layer of refractory metal wire, gauze, foil or the like. The mandrel is so constructed that stresses, which heretofore have developed in the glass layer during cooling, are avoided, and the mandrel is easily removed from the glass layer, thereby forming a hollow glass cylinder that is free from cracks, checks and the like.

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Painted Post, NY, United States of America

Gerald E Burke