Abstract: An apparatus and related process for producing a high-strength weld between two glass components. Chucks clamp and move respective first ends of the glass components toward each other inside an enclosure, where the second ends are heated, softened, and welded together in a weld zone. The enclosure has layers of stacked quartz glass bricks and allows the weld zone to cool slowly and avoid stress. A propane quartz melting torch directs a flame inside the enclosure and toward the second ends as the glass components move toward each other. The flame softens the second ends and creates substantially smooth polished surfaces in the weld zone having an increased hydroxide content. At least 80% of the weld zone has a hydroxide content greater than about 10 ppm average in a 10 ?m depth from the surface and the tensile strength of the weld zone is above about 10 MPa.

Abstract: Known heating burners for producing a welded joint between components of quartz glass include a burner head in which at least one burner nozzle is formed, a burner-head cooling system for the temperature control of the burner head and a supply line connected to the burner nozzle for a fuel gas. Starting from this, to modify a heating burner in such a way that impurities in the weld seam between quartz-glass components to be connected are largely avoided, it is suggested that the burner head should include a base body of silver or of a silver-based alloy.

Abstract: Methods are known for producing an anti-resonant hollow-core fiber which has a hollow core extending along a fiber longitudinal axis and an inner jacket region that surrounds the hollow core, said jacket region comprising multiple anti-resonant elements. The known methods have the steps of: providing a cladding tube that has a cladding tube inner bore and a cladding tube longitudinal axis along which a cladding tube wall extends that is delimited by an interior and an exterior; providing a number of tubular anti-resonant element preforms; arranging the anti-resonant element preforms at target positions of the interior of the cladding tube wall, thereby forming a primary preform which has a hollow core region and an inner jacket region; and elongating the primary preform in order to form the hollow-core fiber or further processing the primary preform in order to form a secondary preform.

Abstract: Known heating burners for producing a welded joint between components of quartz glass include a burner head in which at least one burner nozzle is formed, a burner-head cooling system for the temperature control of the burner head and a supply line connected to the burner nozzle for a fuel gas. Starting from this, to modify a heating burner in such a way that impurities in the weld seam between quartz-glass components to be connected are largely avoided, it is suggested that the burner head should include a base body of silver or of a silver-based alloy.

Abstract: Known heating burners for producing a welded joint between components of quartz glass include a burner head in which at least one burner nozzle is formed, a burner-head cooling system for the temperature control of the burner head and a supply line connected to the burner nozzle for a fuel gas. Starting from this, to modify a heating burner in such a way that impurities in the weld seam between quartz-glass components to be connected are largely avoided, it is suggested that the burner head should include a base body of silver or of a silver-based alloy.

Abstract: An apparatus and related process for producing a high-strength weld between two glass components. Chucks clamp and move respective first ends of the glass components toward each other inside an enclosure, where the second ends are heated, softened, and welded together in a weld zone. The enclosure has layers of stacked quartz glass bricks and allows the weld zone to cool slowly and avoid stress. A propane quartz melting torch directs a flame inside the enclosure and toward the second ends as the glass components move toward each other. The flame softens the second ends and creates substantially smooth polished surfaces in the weld zone having an increased hydroxide content. At least 80% of the weld zone has a hydroxide content greater than about 10 ppm average in a 10 ?m depth from the surface and the tensile strength of the weld zone is above about 10 MPa.

Abstract: Apparatus and method for producing elongated glass components with low bow. The apparatus may include a heating element to heat a bulk glass component where a strand may be drawn from the bulk glass component in a downward direction and a gripper device including a clamping element to support the strand while pulling or drawing it from the bulk glass component in a linear motion, and a low-friction mounting element attached to the clamping element which allows translational movement of the clamping element in an x-y plane. The gripper device may further be used to reduce bow in the strand while it is being drawn by moving the clamping element on the mounting element in a direction opposite the direction of any measured transverse acceleration.

Abstract: A method for producing substrate tubes of quartz glass includes continuously supplying a hollow cylinder of quartz glass to a heating zone, softening the hollow cylinder zonewise in the heating zone, and drawing off a tubular strand from the softened portion. The hollow cylinder has an outer diameter Ca, an inner diameter Ci and an inner bore. The tubular strand has an outer diameter Ta and an inner diameter Ti. The following parameters are applicable to the hollow cylinder and the tubular strand: Ca>180 mm, Cr>3 with Cr=Ca/Ci, Tr<1.6 with Tr=Ta/Ti and Ci/Ti<2.5. The blow pressure in an inner bore is adjusted to a value in the range of 4 to 10 mbar. Substrate tubes, obtained by cutting the tubular strand to the desired length, serve as semi-finished products for the manufacture of preforms for optical fibers.

Abstract: Known heating burners for producing a welded joint between components of quartz glass include a burner head in which at least one burner nozzle is formed, a burner-head cooling system for the temperature control of the burner head and a supply line connected to the burner nozzle for a fuel gas. Starting from this, to modify a heating burner in such a way that impurities in the weld seam between quartz-glass components to be connected are largely avoided, it is suggested that the burner head should include a base body of silver or of a silver-based alloy.

Abstract: Apparatus and method for producing elongated glass components with low bow. The apparatus may include a heating element to heat a bulk glass component where a strand may be drawn from the bulk glass component in a downward direction and a gripper device including a clamping element to support the strand while pulling or drawing it from the bulk glass component in a linear motion, and a low-friction mounting element attached to the clamping element which allows translational movement of the clamping element in an x-y plane. The gripper device may further be used to reduce bow in the strand while it is being drawn by moving the clamping element on the mounting element in a direction opposite the direction of any measured transverse acceleration.

Abstract: A method for producing substrate tubes of quartz glass includes continuously supplying a hollow cylinder of quartz glass to a heating zone, softening the hollow cylinder zonewise in the heating zone, and drawing off a tubular strand from the softened portion. The hollow cylinder has an outer diameter Ca, an inner diameter Ci and an inner bore. The tubular strand has an outer diameter Ta and an inner diameter Ti. The following parameters are applicable to the hollow cylinder and the tubular strand: Ca>180 mm, Cr>3 with Cr=Ca/Ci, Tr<1.6 with Tr=Ta/Ti and Ci/Ti<2.5. The blow pressure in an inner bore is adjusted to a value in the range of 4 to 10 mbar. Substrate tubes, obtained by cutting the tubular strand to the desired length, serve as semi-finished products for the manufacture of preforms for optical fibers.

Abstract: A method for using a temperature control loop in order to further develop process control during elongation of a cylindrical preform such that a component strand with high dimensional accuracy can be drawn even in the presence of temperature-effective defects during the elongation process: (a) the continuous measurement of a first temperature value, Ttop, at an upper measuring point on the surface of the cylindrical preform; (b) the continuous measurement of a second temperature value, Tbottom, at a lower measuring point; (c) calculation of a temperature distribution in the region between the measuring points Ttop and Tbottom, and determination of a modelled deformation temperature, Tmodel, using an algorithmic model taking with first and the second temperature values as model input parameters, and the modelled deformation temperature, Tmodel, as a regulating variable and the heating-zone temperature Toven as a manipulated variable for the temperature-control loop.

Abstract: A method of manufacturing an optical fiber preform or an optical fiber is provided. The method includes the steps of: (a) providing a glass tube and a glass core rod; (b) inserting the glass core rod into the glass tube to form an assembled body; (c) heating the assembled body to cause the glass tube to collapse on and adhere to the glass core rod; and (d) treating an interface gap between the glass core rod and the glass tube during heating of at least a portion of the assembled body. Treating of the interface gap involves: (i) establishing a vacuum pressure in the interface gap, (ii) increasing a pressure of the interface gap by a treatment gas through the interface gap for a predetermined time, and (iii) re-establishing a vacuum pressure in the interface gap after the predetermined time has elapsed.

Abstract: A method for using a temperature control loop in order to further develop process control during elongation of a cylindrical preform such that a component strand with high dimensional accuracy can be drawn even in the presence of temperature-effective defects during the elongation process: (a) the continuous measurement of a first temperature value, Ttop, at an upper measuring point on the surface of the cylindrical preform; (b) the continuous measurement of a second temperature value, Tbottom, at a lower measuring point; (c) calculation of a temperature distribution in the region between the measuring points Ttop and Tbottom, and determination of a modelled deformation temperature, Tmodel, using an algorithmic model taking with first and the second temperature values as model input parameters, and the modelled deformation temperature, Tmodel, as a regulating variable and the heating-zone temperature Toven as a manipulated variable for the temperature-control loop.

Abstract: A method of manufacturing an optical fiber preform or an optical fiber is provided. The method includes the steps of: (a) providing a glass tube and a glass core rod; (b) inserting the glass core rod into the glass tube to form an assembled body; (c) heating the assembled body to cause the glass tube to collapse on and adhere to the glass core rod; and (d) treating an interface gap between the glass core rod and the glass tube during heating of at least a portion of the assembled body. Treating of the interface gap involves: (i) establishing a vacuum pressure in the interface gap, (ii) increasing a pressure of the interface gap by a treatment gas through the interface gap for a predetermined time, and (iii) re-establishing a vacuum pressure in the interface gap after the predetermined time has elapsed.

Abstract: The present invention refers to a drawing method for producing cylindrical components of quartz glass in that a quartz glass strand is drawn off in the direction of a drawing axis from a shaping zone of soft quartz glass mass and sections having a cutting length are separated from the quartz glass strand, and the cylindrical components are produced from the sections.

Abstract: In a known drawing method for producing cylinder-shaped components from quartz glass, a quartz glass strand (10) is drawn in the direction of a drawing axis (12) from a deformation region of a quartz glass mass (9) and pieces having a cutting length (S) are separated therefrom. The cylinder-shaped components are produced from the pieces. In order to provide a simple drawing method for producing quartz glass components, wherein the effects of geometric disruptions, in particular variations in diameter and material rejects, are reduced, the separation of the quartz glass strand (10) is carried out at a separating position (T), wherein the distance of the separating position from the deformation region (9) is set in a way such that a disruption of the quartz glass strand geometry created by the separation lies in an end region of the component to be produced or between two neighboring components during a subsequent separation.

Abstract: According to a known vertical drawing method for producing a cylindrical glass body, the cylinder longitudinal axis of the glass cylinder is adjusted by hand in relation to the longitudinal axis of a heating tube. The aim of the invention is to optimize the stability of said glass body.

Abstract: Known synthetic quartz glass tubes for the production of a preform have an inner bore with a surface layer produced without using tools in the molten state and an inner zone. The aim of the invention is to provide a tube which does not release any OH groups to the surroundings. For this purpose, the surface layer (30) has a thickness of 10 ?m and an average OH content of not more than 5 ppm by weight and an average surface roughness Ra of not more than 0.1 ?m. The inner zone (34) that starts on the surface layer (30) and terminates 10 ?m before the outer wall has an average OH content of not more than 0.2 ppm by weight. A simple and inexpensive method for producing a quartz tube of the above type is to continuously draw a tube strand from a softened quartz glass mass in a vertical drawing process. A scavenging gas is circulated through the inner bore of the tube, said gas having a water content of less than 100 ppb per weight.

Abstract: In a known method for producing tubes of quartz glass, a hollow cylinder (2) of quartz glass is continuously supplied to a heating zone (1) and is softened therein in regions, and a tube strand (21) is drawn off at a drawing speed from the softened region with formation of a drawing bulb (26), and the tubes to be produced are cut to length in the form of tube strand pieces by separating the tube strand (21) at a desired separation point (T, Vu, Vo) and an internal pressure differing from the external pressure applied to the outer cladding is maintained in the inner bore (4) of the hollow cylinder (2) in that the inner bore (4) of the tube strand is provided with a flow obstacle.