An optical fiber preform production method includes: inserting at least one glass rod into at least one through-hole that penetrates a cladding glass body that is a cladding of an optical fiber; integrating a dummy rod by either integrating a solid dummy silica rod with a first end of the cladding glass body by heating the first end to close a first opening of the through-hole that opens in the first end, or forming a base end seal that closes the first opening in the first end and integrating the solid dummy silica rod with the base end; and closing a second opening of the through-hole that opens in a second end of the cladding glass body by heating and deforming the second end.

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.

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.

The invention relates to a securing method, comprising the following Steps: providing an optical waveguide made of a material with a first melting temperature, wherein a sensor region of the optical waveguide has at least one integrated temperature sensor element; providing a capillary made of a material with a second melting temperature, in such a way that the capillary surrounds at least regions of the sensor region of the optical waveguide, and that a securing region of the capillary is arranged at a distance from the sensor region, wherein the second melting temperature is lower than the first melting temperature, wherein the temperature sensor element is arranged in an end region of the optical waveguide, and the end region is inserted into the capillary; securing the securing region of the capillary to the optical waveguide, involving a heating of the securing region of the capillary to a heating temperature that is equal to or higher than the second melting temperature; and heating the free end of the capillary to a heating temperature that is equal to or higher than the second melting temperature. A temperature sensor comprising an optical waveguide with at least one integrated temperature sensor element can be obtained with the method. A securing device comprises an Insertion region for the capillary, a detector and a heating region. The securing device can be used for carrying out the method.

A method of making an optical fibre preform comprising providing a hollow outer tube of glass, providing a hollow primary capillary tube of glass with an outer diameter smaller than an inner diameter of the outer tube, positioning the primary capillary tube inside the outer tube such that an outer surface of the primary capillary tube lies against an inner surface of the outer tube along a contact line parallel to the longitudinal axes of the primary capillary tube and the outer tube, and bonding the primary capillary tube into its position inside the outer tube by directing a laser beam onto a surface of the outer tube or the primary capillary at one or more locations aligned with the contact line.

A method of making an optical fibre preform comprising providing a hollow outer tube of glass, providing a hollow primary capillary tube of glass with an outer diameter smaller than an inner diameter of the outer tube, positioning the primary capillary tube inside the outer tube such that an outer surface of the primary capillary tube lies against an inner surface of the outer tube along a contact line parallel to the longitudinal axes of the primary capillary tube and the outer tube, and bonding the primary capillary tube into its position inside the outer tube by directing a laser beam onto a surface of the outer tube or the primary capillary at one or more locations aligned with the contact line.

The present invention provides a vacuum glass and a preparation method thereof. The vacuum glass comprises a glass body, a cavity enclosed by the glass body and a sealant, and a getter disposed in the cavity; the cavity is hermetic; the getter is a non-evaporable getter, the vacuum glass does not comprise an enclosure for enclosing the getter, and the enclosure is made of a hermetic material; and in a direction passing through the cavity, the vacuum glass has a thermal conductivity value K less than or equal to 4 W/(m.sup.2.Math.K). The vacuum glass does not comprise an enclosure for enclosing the getter.

The present invention provides a vacuum glass and a preparation method thereof. The vacuum glass comprises a glass body, a cavity enclosed by the glass body and a sealant, and a getter disposed in the cavity; the cavity is hermetic; the getter is a non-evaporable getter, the vacuum glass does not comprise an enclosure for enclosing the getter, and the enclosure is made of a hermetic material; and in a direction passing through the cavity, the vacuum glass has a thermal conductivity value K less than or equal to 4 W/(m.sup.2.Math.K). The vacuum glass does not comprise an enclosure for enclosing the getter.

Processes for fusing opaque fused quartz to clear fused quartz to form ultraviolet light transmission windows comprise surrounding a clear fused quartz ingot with an opaque fused quartz sleeve or opaque fused quartz particles, then heating the clear and opaque fused quartz together in a furnace, past the transition temperature of the opaque fused quartz, in order to join the two types of quartz together around the perimeter of the clear fused quartz ingot, but without substantial mixing beyond the interface.

Processes for fusing opaque fused quartz to clear fused quartz to form ultraviolet light transmission windows comprise surrounding a clear fused quartz ingot with an opaque fused quartz sleeve or opaque fused quartz particles, then heating the clear and opaque fused quartz together in a furnace, past the transition temperature of the opaque fused quartz, in order to join the two types of quartz together around the perimeter of the clear fused quartz ingot, but without substantial mixing beyond the interface.