Abstract: The present invention provides an optical member having a high transmittance, wherein a composition change of a phase-separable base material glass film is suppressed. A method for manufacturing an optical member provided with a porous glass film on the base member includes the steps of forming a glass powder film containing a glass powder on the base member, forming a phase-separable base material glass film on the base member by heating and fusing the glass powder film in an atmosphere having an oxygen concentration of more than 20%, forming a phase-separated glass film on the base member by heating the base material glass film, and forming a porous glass film on the base member by subjecting the phase-separated glass film to an etching treatment.

Abstract: A glass ribbon has a thickness of 100 ?m or less and includes a convex curved surface portion on a side surface. The glass ribbon can be produced by heating a preform glass material having a thickness of 2 mm or less, and subjecting the preform glass material to drawing so that the preform glass material has a thickness of 100 ?m or less.

Abstract: A method for manufacturing a primary preform for optical fibers including surrounding at least part of a hollow substrate tube with a furnace set at a temperature T0, supplying doped or undoped gases to the inside of the tube, creating a reaction zone to promote deposition, and moving the zone back and forth along the length of the tube between to form at least one preform layer, wherein the temperature of the furnace is varied linearly as a function of the thickness of the at least one preform layer to compensate for temperature increases of the tube during deposition.

Abstract: A plant for melting glass or rock including: a first melting tank including a batch material inlet, a heater that makes it possible to heat the batch materials until a liquid glass is obtained; a liquid glass outlet; and downstream of the melting tank, a second heating tank including metallic walls that are not covered with refractory insulating materials and that include a system of internal ducts allowing circulation of a coolant, a plurality of injectors of submerged burners, and a liquid glass outlet, in a form of an overflow, which limits a height of the glass bath in the heating tank to a value between 50 mm and 300 mm. A process for melting glass or rock uses such a melting plant.

Abstract: A glass ribbon engagement system is described herein that includes a robot tooling device with suction cups configured to engage a first side of a glass ribbon, and a guidance device with one or more devices (e.g., air nozzles, cylinder-wheel units) which are configured to apply one or more local forces to a second side of the glass ribbon to shift the glass ribbon towards the suction cups to assist the suction cups in engaging and securing the first side of the glass ribbon.

Abstract: A device for manufacturing an optical preform by means of an internal vapor deposition process including an energy source, a hollow substrate tube having a supply side and a discharge side and the energy source being moveable along a length of the hollow substrate tube, and an elongation tube connected to the hollow substrate tube at the discharge side thereof, wherein the hollow substrate tube extends into an interior of the elongation tube and an internal diameter of the elongation tube is at least 0.5 millimeters larger than an external diameter of the hollow substrate tube.

Abstract: A gas supplying unit supplies a nitrogen gas into a furnace body of a graphite heating furnace in which at least a part of the furnace body is formed with a graphite. An exhausting unit exhausts a gas inside the furnace body to outside the furnace body. A dew-point temperature of the nitrogen gas supplied into the furnace body is equal to or lower than ?80° C. A pressure inside the furnace body is equal to or higher than 140 Pa with respect to an atmospheric pressure outside the furnace body.

Abstract: A glass sheet three stage forming station utilizes first and second upper molds and a lower mold to provide three stage forming. The glass is curved on the upper mold in the first stage but retains straight line elements transverse to the curvature. Transfer of the initially formed glass sheet from the first upper mold to the lower mold then provides the second stage of gravity forming and the glass sheet is then press formed between the second upper mold and the lower mold in the third stage which reduces optical distortion in the central viewing area of the formed glass sheet. The glass sheet is moved horizontally on the first upper mold and released onto the lower mold.

Abstract: An apparatus for making a glass sheet using overflow fusion down-draw process comprising an inlet assembly having an elliptic cylindrical section coupled to a transition section which is, in turn, coupled to an open end of an open channel of an isopipe, and an overflow fusion down-draw process for making glass sheet. The glass melt flow has a high surface velocity profile conducive to the formation of a glass ribbon over the surface of the weirs and the wedge side surfaces with the desired mass distribution.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: When drawing of a GRIN lens from a preform is started, wastage of the preform is reduced and the amount of time taken from the start of elongation of the preform to the start of winding is reduced. A preform, to a lower end of which a weight formed of silica is fused, is set in a heating furnace, and drawing of the preform is started by heating a fused portion where the preform and the weight are fused to each other. This can reduce wastage of the preform. Since an elongation speed of the preform is increased by the weight of the weight, the amount of time taken from the start of the elongation of the preform to the start of winding can be decreased.

Abstract: An apparatus for manufacturing a glass perform, includes: a dummy tube section, a reservoir portion, and a cooling portion; and a glass tube section in which particles of an alkali metal compound or an alkaline earth metal compound which have flowed into the glass tube section from the dummy tube section are heated by a second heat source which performs traverse, and oxides of the particles being deposited on an inner wall and dispersed in the glass tube section. In the cooling portion of the dummy tube section, vapor of the alkali metal compound or the alkaline earth metal compound generated by heating of a first heat source is cooled and condensed by a dry gas flowing into the dummy tube section, and thereby the particles are generated.

Abstract: The production of quartz glass granules comprises the granulation of pyrogenically produced silicic acid and the formation of a SiO2 granulate (9), the drying and cleaning of the SiO2 granulate (9) by heating in an atmosphere containing halogen, and the vitrification of the SiO2 granulate (9) under a treatment gas which contains at least 30% by volume of helium and/or hydrogen. This process is time-consuming and expensive.

Abstract: A mask for laser sealing a temperature and environmentally sensitive element, such as an OLED device, surrounded by a frit wall between first and second substrates. The mask is opaque and has a transparent elongate transmission region. The width of the transmission region may be substantially equal to the width of the frit wall. A strip of opaque mask material extends approximately along a longitudinal center line of the elongate transmission region. The mask is located between a laser and the first or second substrate. The laser emits a generally circular beam having a diameter that is larger than the width of the frit wall and is directed through the transmission region in the mask, such that opaque portions of the mask block portions the laser beam and the transparent transmission region allows a portion of the laser beam to pass through the mask and impinge upon the frit wall to melt the frit wall, thereby joining the first and second substrates and hermetically sealing the element therebetween.

Abstract: Methods of forming a glass ribbon with a glass forming apparatus including a first glass roll device are disclosed. The methods include a step (I) of drawing the glass ribbon along a draw direction with the glass forming apparatus. Also included is a step (II) of adjusting a first roll member relative to a first support structure of the first glass roll device by translating the first roll member in a first linear direction parallel to a linear adjustment axis of the first support structure while the first roll member is adjustably mounted to the first support structure. Also included is a step (III) of contacting a first surface of the glass ribbon with the first roll member at a first adjusted contact location of the glass ribbon. Also disclosed are corresponding glass forming apparatus configured to form glass ribbons and draw the glass ribbons in a draw direction.

Abstract: An apparatus and method for pulling tubular glass, such as pipettes, is disclosed. The invention is generally directed apparatus and techniques for precisely scanning a laser beam on the selected surfaces of the glass tube to uniformly, controllably and programmably soften the tube prior to and during pulling. The invention has application to both vertical and horizontal pullers.

Abstract: The present invention concerns a method of making a mineral melt by burning combustible material in the presence of inorganic particulate material and thereby forming a melt, comprising injecting fuel, particulate mineral material and combustion gas into a circulating combustion chamber (1) through an inlet conduit (4) and combusting the fuel in the circulating combustion chamber (1) thereby melting the mineral material to form a mineral melt and generating exhaust gases; separating the exhaust gases from the mineral melt, collecting the mineral melt (9) and passing the exhaust gases upwards through an exhaust pipe (10) to a conduit (11) of a heat exchange system; and supplying particulate mineral material and a first portion of waste mineral wool into the conduit (11) and pre-heating the supplied material in the heat exchange system, and supplying a second portion of waste mineral wool with a water content between 5 and 25% by weight directly to the inlet conduit (4).

Abstract: Methods for machining glass structures may be performed on fusion-drawn glass laminates having a core layer interposed between a first cladding layer and a second cladding layer. The core layer may be formed from a core glass composition having a core photosensitivity, the first cladding layer may be formed from a glass composition having a photosensitivity different from the core photosensitivity, and the second cladding layer may be formed from a glass composition having a photosensitivity different from the core photosensitivity. At least one of the core layer, the first cladding layer, and the second cladding layer is a photomachinable layer. The methods may include exposing a selected region of a photomachinable layer in the fusion-drawn laminate to ultraviolet radiation; heating the glass structure until the selected region crystallizes; and removing the crystallized material selectively from the photomachinable layer.

Abstract: A refractive index device and method of making it include obtaining a glass structure comprising a plurality of nucleation sites. The glass structure is formed from a glass composition that comprises a first chemical component and a second chemical component. A crystal of the second chemical component has a different second refractive index from a first refractive index of the first chemical component. Each nucleation site defines where a crystal of the second chemical component can be grown. The method includes causing crystals of the second chemical component to grow in situ at a set of the plurality of nucleation sites in order to produce a spatial gradient of a refractive index in the glass structure.

Abstract: The invention relates to a device (1, 1?, 1?) for cooling an optical fiber (13), including two portions (20, 29), each of the portions (20, 29) including at least one receiving surface (204, 294) on which a half-channel (240, 2490) is provided, such that, once the two portions (20, 29) are placed in contact at the receiving surface (204, 294) thereof, the two portions (20, 29) form a main through-channel for accommodating the passage of the optical fiber (13), characterized in that each of the portions (20, 29) is a block of a thermally conductive material and in that at least one (20) of the portions includes a cylindrical secondary channel (209), which is in fluid connection with a plurality of openings (2046) distributed along the half-channel (2040) of said portion (20), in order to form a heat-transfer fluid distribution chamber for the plurality of openings (2046).