Abstract: A hollow-core optical fiber may include a hollow core extending along a central longitudinal axis of the fiber; a substrate; a plurality of first cladding elements spaced apart from each other and positioned between the hollow core and the substrate, each of the first cladding elements extending in a direction parallel to the central longitudinal axis of the fiber, each of the first cladding elements including a first capillary; and a plurality of second cladding elements spaced apart from each other and positioned between the hollow core and the substrate, each of the second cladding elements extending in a direction parallel to the central longitudinal axis of the fiber, each of the second cladding elements including a second capillary. Each of the first cladding elements directly contacts the inner surface of the substrate, and none of the second cladding elements directly contacts the inner surface of the substrate.

Abstract: A hollow-core optical fiber may include a hollow-core extending along a central longitudinal axis of the hollow-core optical fiber; a substrate; a first cladding positioned between the central longitudinal axis and an inner surface of the substrate, the first cladding surrounding the central longitudinal axis of the hollow-core optical fiber and having a Bragg structure configured to provide a photonic bandgap operable to confine an optical signal with a wavelength ? propagating in the hollow-core of the hollow-core optical fiber; and a second cladding positioned between the central longitudinal axis of the hollow-core optical fiber and the inner surface of the substrate, the second cladding surrounding the central longitudinal axis of the hollow-core optical fiber and including a plurality of cladding elements configured to provide an anti-resonant effect at the wavelength ?, the anti-resonant effect operable to confine the optical signal at the wavelength ? in the hollow-core.

Abstract: A method for producing a hollow-core preform may include rolling a glass sheet to form a rolled-glass structure; and attaching one or more of the rolled-glass structures to an inner surface of an annular support structure to form a hollow-core preform, wherein the inner surface of the annular support structure defines an interior cavity and the one or more of the rolled-glass structures are positioned within the interior cavity. The hollow-core preform may be drawn into a hollow-core optical fiber.

Abstract: A hollow-core optical fiber may include a substrate having a tubular shape and an inner surface surrounding a central longitudinal axis of the hollow-core optical fiber; a hollow core extending through the substrate along the central longitudinal axis of the hollow-core optical fiber; and a plurality of cladding elements positioned between the central longitudinal axis of the hollow-core optical fiber and the substrate. Each of the plurality of cladding elements may extend in a direction parallel to the central longitudinal axis of the hollow-core optical fiber. Each of the plurality of cladding elements may include a wound glass sheet configured as a spiral, and each of the plurality of cladding elements may contact an interior surface of the substrate.

Abstract: A hollow-core optical fiber may include a hollow core extending along a central longitudinal axis of the fiber; a substrate, the substrate having a tubular shape and an inner surface surrounding the central longitudinal axis of the fiber; and a plurality of cladding elements positioned between the hollow core and the substrate, each of the cladding elements extending in a direction parallel to the central longitudinal axis of the fiber. Each of the cladding elements includes a primary capillary, the primary capillary directly contacting the inner surface of the substrate and having an inner surface defining a cavity, and a plurality of nested capillaries positioned within the cavity, each of the nested capillaries directly contacting the inner surface of the primary capillary.

Abstract: Glass forming devices can comprise a first outer surface of a first wall, a second outer surface of a second wall, and a heater. Glass forming methods can comprise flowing a first stream of molten material over a first outer surface of the first wall and flowing a second stream of molten material over a second outer surface of the second wall. Methods can further comprise drawing a glass ribbon. Methods can also comprise heating the first wall with the heater to heat an inner portion of the first stream of molten material contacting the first outer surface of the first wall to maintain a viscosity of the inner portion of the first stream of molten material below the liquidus viscosity of the first stream of molten material.

Abstract: A method of manufacturing a sheet of glass comprises: (a) forming a vertically oriented ribbon of glass that moves downward as a function of time, the ribbon of glass having a first primary surface and a second primary surface that face in generally opposite directions and a core disposed between the first and second primary surfaces; (b) as the ribbon of glass moves downward, passing the ribbon of glass adjacent to a first raised temperature zone liquefies the first primary surface while a temperature of the core remains below a softening temperature; and (c) after the ribbon of glass moves below the first raised temperature zone, separating a sheet of glass from the ribbon of glass. Passing the ribbon of glass adjacent the first raised temperature zone reduces total thickness variation, surface roughness, and other surface defects of the ribbon of glass.

Abstract: A method of forming a glass ribbon including flowing molten glass into a sheet forming device to form formed glass. The formed glass having a first portion and a second portion, the first portion having a larger thickness than the second portion. The method further includes volumetrically heating the formed glass using an electromagnetic heating device, so that the first portion has a lower average viscosity than the second portion, and drawing the formed glass into a glass ribbon, such that the first portion is drawn with a higher rate of elongation than the second portion.

Abstract: A laminated glass article having a core layer made from a glass that is not ion-exchangeable, and a clad layer made from a glass that is ion-exchangeable. The laminated glass article has a maximum compressive stress in the clad layer from about 0.05 GPa to about 0.7 GPa, and a compressive stress at an inner surface of the clad layer directly adjacent to the core layer from about 20% to about 45% of a compressive stress at an outer surface of the clad layer. A slope of a stress profile in the clad layer is substantially linear. Methods for manufactured such a laminated glass article also are disclosed.

Abstract: A method and apparatus for forming a glass ribbon comprising a forming body configured to form a continuously moving glass ribbon that is drawn therefrom, a first heating or cooling apparatus to initiate a crack in a viscoelastic region of the continuously moving glass ribbon, and a second heating or cooling apparatus to locate or stop the initiated crack in the continuously moving glass ribbon.

Abstract: A glass forming apparatus and method include a cooling mechanism in a wall of the apparatus that enhances radiation heat transfer between the glass and the wall of the apparatus and is tunable in both the vertical and horizontal directions. The apparatus and method also include a heating mechanism that affects radiation heat transfer between the glass and the wall of the apparatus, is tunable in both the vertical and horizontal directions, and is independently operable from the cooling mechanism.

Abstract: A laminated glass article having a core layer made from a glass that is not ion-exchangeable, and a clad layer made from a glass that is ion-exchangeable. The laminated glass article has a maximum compressive stress in the clad layer from about 0.05 GPa to about 0.7 GPa, and a compressive stress at an inner surface of the clad layer directly adjacent to the core layer from about 20% to about 45% of a compressive stress at an outer surface of the clad layer. A slope of a stress profile in the clad layer is substantially linear. Methods for manufactured such a laminated glass article also are disclosed.

Abstract: An apparatus for making a laminate glass ribbon, the glass ribbon having: a center laminate region, a first edge, a second edge, and first, second, third, and fourth, beads portions as defined herein, the apparatus includes: a bead thermal conditioning region including: a fluid source for selectively applying a fluid to one or more of the first, second, third, and fourth bead portions. Also disclosed is a method for bead thermal conditioning in the disclosed laminate fusion apparatus.

Abstract: An apparatus for making a laminate glass ribbon, the glass ribbon having: a center laminate region, a first edge, a second edge, and first, second, third, and fourth, beads portions as defined herein, the apparatus includes: a bead thermal conditioning region including: a fluid source for selectively applying a fluid to one or more of the first, second, third, and fourth bead portions. Also disclosed is a method for bead thermal conditioning in the disclosed laminate fusion apparatus.

Abstract: A method for making a glass laminate sheet including: selecting a core glass composition and a clad glass composition combination for a glass laminate structure; determining and comparing the viscosity and coefficient of thermal expansion (CTE) profiles for each of the selected core and the clad glass compositions with each other over a temperature range of interest including the onset of viscoelasticity to ambient temperature; and processing the selected core and clad glass composition in a laminate fusion draw apparatus to form a laminate glass sheet in accordance with at least one difference condition for the clad effective coefficient thermal expansion (CTEeff core) and the core effective coefficient thermal expansion (CTEeff core). Another method for making a glass laminate sheet includes controlling the cooling rate to control the resulting strength of the laminate.

Abstract: A method for making a glass laminate sheet including: selecting a core glass composition and a clad glass composition combination for a glass laminate structure; determining and comparing the viscosity and coefficient of thermal expansion (CTE) profiles for each of the selected core and the clad glass compositions with each other over a temperature range of interest including the onset of viscoelasticity to ambient temperature; and processing the selected core and clad glass composition in a laminate fusion draw apparatus to form a laminate glass sheet in accordance with at least one difference condition for the clad effective coefficient thermal expansion (CTEeff core) and the core effective coefficient thermal expansion (CTEeff core). Another method for making a glass laminate sheet includes controlling the cooling rate to control the resulting strength of the laminate.