Abstract: A method of making a strengthened glass article. The method includes altering the glass structure and subsequently creating a compressive layer extending from the surface of the glass to a depth of layer. In some embodiments, the structure is altered by heat treating the glass at a temperature that is less than the annealing point of the glass, and the compressive layer is formed by ion exchange. A strengthened glass article made by the method is also provided.

Abstract: Computer-implemented methods and apparatus are provided for predicting/estimating chemical depth of layer (DOL) and maximum surface compressive stress (CS) of glass articles after ion-exchange. The methods and apparatus can, for example, be used to select glass compositions, salt bath temperatures, and/or ion-exchange times which provide desired DOL and/or CS values. One or more manufacturing constraints, e.g., constraints on liquidus viscosity, zircon breakdown viscosity, and the like, can be applied to the process of predicting/estimating DOL and/or CS values so that glass compositions selected based on DOL and/or CS values can, for example, be manufactured commercially by a fusion or float process.

Abstract: Methods of drawing glass sheet via a downdraw process are provided. In certain aspects, the methods utilize rapid cooling below the root (70) of the forming apparatus (10). Such rapid cooling can, for example, facilitate the use of glass having a liquidus viscosity less than about 100,000 poise. In other aspects, the methods utilize slow cooling between the viscosities of 1011 poises and 1014 poises. Such slow cooling can facilitate the production of glass substrates which exhibit low levels of compaction. In further aspects, substrates are removed from the glass sheet at elevated temperatures which can facilitate increases in the production rates of downdraw machines. In still further aspects, rapid cooling below the root, slow cooling between the viscosities of 1011 poises and 1014 poises, and/or substrate removal at elevated temperatures are combined. Such combinations can facilitate economically effective utilization of downdraw equipment.

Abstract: The present disclosure is directed to a method for producing constancy of the ion-exchanged product stress profile through adjustment of ion-exchange conditions by taking account of the influence of salt bath poisoning on the bath's useful lifetime. The present disclosure is directed to a method of ion-exchange in which the salt bath temperature and salt bath time are adjusted as a function of the amount of alkali metal ions that exchange in the bath. That is, temperature and time are adjusted as a function of salt bath poisoning. Temperature is set to its highest value and time to its shortest value in the starting un-poisoned salt bath, those values chosen to hit target values of surface compressive stress and exchange depth of layer. Temperature is then reduced and time lengthened as salt bath poisoning proceeds, those changes chosen to maintain the same surface compressive stress and exchange depth of layer.

Abstract: The present disclosure is directed to a method for producing constancy of the ion-exchanged product stress profile through adjustment of ion-exchange conditions by taking account of the influence of salt bath poisoning on the bath's useful lifetime. The present disclosure is directed to a method of ion-exchange in which the salt bath temperature and salt bath time are adjusted as a function of the amount of alkali metal ions that exchange in the bath. That is, temperature and time are adjusted as a function of salt bath poisoning. Temperature is set to its highest value and time to its shortest value in the starting unpoisoned salt bath, those values chosen to hit target values of surface compressive stress and exchange depth of layer. Temperature is then reduced and time lengthened as salt bath poisoning proceeds, those changes chosen to maintain the same surface compressive stress and exchange depth of layer.

Abstract: In a method of making a glass sheet using an overflow fusion downdraw process, a glass sheet quality metric level Q1 is selected, where Q1 is a measure of allowable retardation in the glass sheet. A glass ribbon temperature T1 at which a potential glass ribbon thermal artifact could occur in a glass ribbon while the glass ribbon is being drawn through a drawing machine enclosure is identified. A thermal artifact envelope E1 is determined, where E1 contains types of glass ribbon thermal artifacts allowable at T1 and Q1. A glass melt is overflowed from an isopipe to form a glass ribbon at the root of the isopipe. The glass ribbon is drawn below the root of the isopipe through the drawing machine enclosure to form the glass sheet.

Abstract: In a method of making a glass sheet using an overflow fusion downdraw process, a glass sheet quality metric level Q1 is selected, where Q1 is a measure of allowable retardation in the glass sheet. A glass ribbon temperature T1 at which a potential glass ribbon thermal artifact could occur in a glass ribbon while the glass ribbon is being drawn through a drawing machine enclosure is identified. A thermal artifact envelope E1 is determined, where E1 contains types of glass ribbon thermal artifacts allowable at T1 and Q1. A glass melt is overflowed from an isopipe to form a glass ribbon at the root of the isopipe. The glass ribbon is drawn below the root of the isopipe through the drawing machine enclosure to form the glass sheet.

Abstract: Methods and apparatus for predicting viscosities of glass materials as a function of temperature and composition are provided. Two fitting parameters (fitting coefficients) are used for each of the viscosity-affecting components contained in the material. The parameters can accurately cover a wide range of temperatures (i.e., a wide range of viscosities) and a wide range of compositions. The viscosity predictions can be used as a guide for glass research as well as in feedback control systems for glass manufacturing processes. Methods and apparatus for predicting glass resistivity are also disclosed.

Abstract: Methods are provided for reducing the dimensional changes of a glass substrate during a display manufacturing process. The reductions are achieved by increasing the fast relaxation exhibited by the glass. Test methods are provided for distinguishing the effects on dimensional changes of fast relaxation versus slow relaxation. Glass substrates which exhibit reduced dimensional changes during critical thermal cycles of display manufacturing processes are also disclosed.

Abstract: Disclosed are synthetic silica glass having a low polarization-induced birefringence, process for making the glass and lithography system comprising optical element made of the glass. The silica glass has a polarization-induced birefringence measured at 633 nm of less than about 0.1 nm/cm when subjected to excimer laser pulses at about 193 nm having a fluence of about 40 ?J·cm?2·pulse?1 and a pulse length of about 25 ns for 5×109 pulses.

Abstract: A strengthened glass that does not exhibit frangible behavior when subjected to impact or contact forces, and a method of strengthening a glass. The glass may be strengthened by subjecting it to multiple, successive, ion exchange treatments. The multiple ion exchange treatments provide a local compressive stress maximum at a depth of the strengthened layer and a second local maximum at or near (e.g., within 10 ?m) the surface of the glass.

Abstract: Disclosed are synthetic silica glass having a low polarization-induced birefringence, process for making the glass and lithography system comprising optical element made of the glass. The silica glass has a polarization-induced birefringence measured at 633 nm of less than about 0.1 nm/cm when subjected to excimer laser pulses at about 193 nm having a fluence of about 40 ?J·cm?2·pulse?1 and a pulse length of about 25 ns for 5×109 pulses.

Abstract: Disclosed are synthetic silica glass having a low polarization-induced birefringence, process for making the glass and lithography system comprising optical element made of the glass. The silica glass has a polarization-induced birefringence measured at 633 nm of less than about 0.1 nm/cm when subjected to excimer laser pulses at about 193 nm having a fluence of about 40 ?J·cm?2·pulse?1 and a pulse length of about 25 ns for 5×109 pulses.

Abstract: A magnetic photonic crystal for providing asymmetry of spatial frequencies in the propagation of light is provided. The crystal is formed from at least two materials having different indices of refraction which are aligned along the longitudinal axis of the crystal. And arranged in an array whose symmetry does not include a spatial inversion operator such that (x,y)==/=(?x,?y). One or more of the materials forming the array is magnetic such that the magnetic group representation of the array does not include time inversion as a symmetric operator. In operation, when the magnetic material forming the material is magnetized, the group velocity property of light propagated in one direction along the axis of the array is different from the group velocity property of light transmitted in an opposite direction through the array. The magnetic photonic crystal may be used, for example, as an optical memory device or a high speed modulator/demodulator.

Abstract: Methods of drawing glass sheet via a downdraw process are provided. In certain aspects, the methods utilize rapid cooling below the root (70) of the forming apparatus (10). Such rapid cooling can, for example, facilitate the use of glass having a liquidus viscosity less than about 100,000 poise. In other aspects, the methods utilize slow cooling between the viscosities of 1011 poises and 1014 poises. Such slow cooling can facilitate the production of glass substrates which exhibit low levels of compaction. In further aspects, substrates are removed from the glass sheet at elevated temperatures which can facilitate increases in the production rates of downdraw machines. In still further aspects, rapid cooling below the root, slow cooling between the viscosities of 1011 poises and 1014 poises, and/or substrate removal at elevated temperatures are combined. Such combinations can facilitate economically effective utilization of downdraw equipment.

Abstract: Disclosed is an optical waveguide fiber preform which is an assembly of one or more core rods surrounded by a plurality of clad rods. The clad rods have a central portion and a surrounding layer, in which the refractive index of the central portion is lower than that of the surrounding layer. The preform is drawn into an optical waveguide fiber that has a two component clad layer. Proper choice of the central portion and surrounding layer provide a waveguide fiber that is endlessly single mode. Alternative embodiments include fibers containing dopants that enhance fiber photosensitivity or which provide stress-induced or asymmetric-refractive-index-induced birefringence in the waveguide fiber.