The present disclosure is directed to a method of making an optical fiber with improved bend performance, the optical fiber having a core and at least one cladding layer, and a chlorine content in the in the last layer of the at least one cladding layer that is greater than 500 ppm by weight. The fiber is prepared using a mixture of a carrier gas, a gaseous chlorine source material and a gaseous reducing agent during the sintering of the last or outermost layer of the at least one cladding layer. The inclusion of the reducing gas into a mixture of the carrier gas and gaseous chlorine material reduces oxygen-rich defects that results in at least a 20% reduction in TTP during hydrogen aging testing.

A doped silica-titania glass article is provided that includes a glass article having a glass composition comprising (i) a silica-titania base glass, (ii) a fluorine dopant, and (iii) a second dopant. The fluorine dopant has a concentration of fluorine of up to 5 wt. % and the second dopant comprises one or more oxides selected from the group consisting of Al, Nb, Ta, B, Na, K, Mg, Ca and Li oxides at a total oxide concentration from 50 ppm to 6 wt. %. Further, the glass article has an expansivity slope of less than 0.5 ppb/K.sup.2 at 20 C. The second dopant can be optional. The composition of the glass article may also contain an OH concentration of less than 100 ppm.

Ultralow expansion titania-silica glass. The glass has high hydroxyl content and optionally include one or more dopants. Representative optional dopants include boron, alkali elements, alkaline earth elements or metals such as Nb, Ta, Al, Mn, Sn Cu and Sn. The glass is prepared by a process that includes steam consolidation to increase the hydroxyl content. The high hydroxyl content or combination of dopant(s) and high hydroxyl content lowers the fictive temperature of the glass to provide a glass having a very low coefficient of thermal expansion (CTE), low fictive temperature (T.sub.f), and low expansivity slope.

Techniques for making glass components for electronic devices are disclosed. The techniques disclosed herein can be used to modify a glass workpiece to form a three-dimensional glass component, such as a glass cover member. The techniques may involve reshaping the glass workpiece, fusing glass layers of the workpiece, or combinations of these. Glass components and electronic devices including these components are also disclosed.

A method of manufacturing a hollow core optical fiber including a vapor deposition step comprising vapor depositing a silica soot coating from one or more source materials over an outer surface of a cladding substrate tube of a workpiece that further includes capillary tubes disposed within a cavity of the cladding substrate tube. The compositions of the capillary tubes, the cladding substrate tube, and the silica soot coating can be manipulated with one or more viscosity-raising dopants or one or more viscosity-lowering dopants, or neither, to achieve a desired compositional profile of a hollow core optical fiber preform with a cladding consolidated from the silica soot coating of the workpiece. The desired composition profile results in a viscosity profile that prevents the capillary tubes from contacting each other during a drawing step performed upon the hollow core optical fiber preform.

To obtain a crystallized glass member having a curved shape and provide a method for producing the same. A method for producing a crystallized glass member having a curved shape, including a deformation step for adjusting the temperature of a plate glass to a first temperature zone from higher than [At+40] C. to [At+146] C. or lower, where At is the yield point ( C.) of the plate glass and deforming at least part of the plate glass into a curved shape by external force acting on the plate glass while precipitating crystals from the plate glass.

A method of preparing a glass-ceramic material, the method comprising the steps of: (a) admixing a crystallisation promoter and a glass; wherein the glass has a median particle distribution (D.sub.50) of from 50 to 70 m; and (b) sintering the admixture obtained in step (a).

A glass-ceramic material and the use of such a glass-ceramic material are also described.