Heraeus Quarzglas Gmbh & Co Kg

Heraeus Quarzglas Gmbh

Heraeus Quartz North America LLC

Jan Vydra

Michael Huenermann

Ralph Sattmann

Martin Trommer

Walter Lehmann

Michael Hünermann

Stephan Thomas

Andreas Langner

Klaus Becker

Stefan Hengster

Manuel Rosenberger

Bruno Uebbing

Peter Bauer

Rene Sowa

Karsten Braeuer

Gerhard Sch&ouml;tz

Oliver Ganz

Stefan Ochs

Kai Huei Chang

Qiulin Ma

Gerhard Schoetz

Clemens Schmitt

Bodo Kühn

Steffen Kaiser

Enrico Ehrentraut

Norbert Cibis

David Kostka

Yusuf Tansel

Benjamin Reis

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. The displacement of the shear zone along the longitudinal axis of the blank is superimposed by a simultaneous oscillating motion of the shear zone along the longitudinal axis of the blank. The first end of the blank is rotated at a first rotational speed and the second end of the blank is rotated at a second rotational speed. An oscillating motion of the shear zone is generated by periodically varying the first and/or second rotational speed.

Method for homogenizing glass

To achieve a high degree of precision and an exact positioning of anti-resonant elements in a sufficiently stable and reproducible manner in 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, formation of anti-resonant element precursors includes formation of elongated pressure chambers, each of which adjoins a wall deformable under pressure and heat in the region of target positions of the anti-resonant elements. A section of the deformable wall is caused to protrude in the direction of a cladding tube inner bore, thereby forming an anti-resonant element or a precursor for same, while carrying out a process of elongating a primary preform to form the hollow-core fiber or further processing the primary preform to a secondary preform from which the hollow-core fiber is drawn.

Methods for producing a hollow-core fiber and for producing a preform for a hollow-core fiber

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. The aim of the invention is to achieve a high degree of precision and an exact positioning of the anti-resonant elements in a sufficiently stable and reproducible manner on the basis of the aforementioned methods. This is achieved in that a positioning template is inserted into the cladding tube inner bore in order to arrange the anti-resonant element preforms, said template having holding elements for positioning the anti-resonant element preforms at the target positions.

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. To enable a radial mixing within the shear zone in addition to the tangential mixing with the lowest possible time and energy input, starting from this method, cylindrical sections of the blank are adjacent to the shear zone on both sides, the first cylindrical section having a first central axis and the second cylindrical section having a second central axis, the first central axis and the second central axis being temporarily non-coaxial with each other.

A known method for homogenizing glass includes the following steps: providing a cylindrical blank composed of the glass, having a cylindrical outer surface which extends between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and moving the shear zone along the longitudinal axis of the blank. To reduce the risk of cracks and fractures during homogenizing, it is proposed that a thermal radiation dissipator is used that at least partially surrounds the shear zone, the lateral dimension of which in the direction of the longitudinal axis of the blank is greater than the shear zone and smaller than the length of the blank, the thermal radiation dissipator being moved synchronously with the shear zone along the longitudinal axis of the blank.

Method and device for homogenizing glass

Methods for producing an optical fiber by elongating a silica glass blank or a coaxial group of silica glass components, on the basis of which a fiber is obtained that comprises a core zone, an inner jacket zone enclosing the core zone and a ring zone surrounding the inner jacket zone, are known. In order to provide, proceeding from this, a method, a tubular semi-finished product and a group of coaxial components for the cost-effective production of an optical fiber, which is characterized by a high quality of the boundary between the core and jacket and by low bending sensitivity, according to the invention, the silica glass of the ring zone is provided in the form of a ring zone tube made of silica glass having a mean fluorine content of at least 6000 weight ppm and the tube has an inner tube surface and an outer tube surface, wherein via the wall of the ring zone tube, a radial fluorine concentration profile is adjusted which has an inner fluorine depletion layer with a layer thickness of at least 1 &#x3bc;m and no more than 10 &#x3bc;m, in which the fluorine content decreases toward the inner tube surface and is no more than 3000 weight ppm in a region close to the surface which has a thickness of 1 &#x3bc;m.

Tubular semifinished product for producing an optical fiber

Method and tubular semifinished product for producing an optical fiber

A known refraction-sensitive optical fiber comprises a core zone with an index of refraction n, a jacket zone surrounding the core zone, said jacket zone having an index of refraction n, and an annular zone made of quartz glass doped with fluorine, said annular zone surrounding the jacket zone and having an index of refraction n, where n&#x3c;n&#x3c;n. With this as a starting point, an optical fiber is to be provided that is characterized by high refraction-sensitivity, good spliceability and compatibility, and a method is to be provided for cost-effective manufacture of such a fiber. With regard to the method, this object is accomplished according to the invention in that the quartz glass of the annular zone () is produced in a plasma deposition process on the outside in which an annular zonal layer made of the quartz glass doped with fluorine is produced on a substrate body (), said layer having a layer thickness of at least 1 mm and an index of refraction n&#x3c;1.4519 relative to the D line of the sodium vapor lamp.

Refraction-sensitive optical fiber, quartz glass tube as a semi-finished product for the manufacture-thereof and method for the manufacture of the fiber

To improve a known method for making a quartz glass tube as a semifinished product for the manufacture of optical fibers, the tube comprising an inner fluorine-doped quartz glass layer and an outer quartz glass layer, so as to achieve inexpensive manufacture and improved dimensional stability of the quartz glass tube, it is suggested according to the invention that the quartz glass of the inner layer should be produced in a first plasma deposition process with formation of an inner layer having a wall thickness of at least 1.5 mm, with a fluorine content of at least 1.5% by wt. being set in the quartz glass, and that the quartz glass of the outer layer should be produced in a second plasma deposition process and deposited directly or indirectly on the inner layer with formation of a composite tube, and that the composite tube should be elongated into the quartz glass tube.

Quartz glass tube as a semifinished product for preform and fiber manufacture, and method for making the quartz glass tube

The production of an optical component from quartz glass by elongation of a coaxial arrangement of a core rod and a hollow cylinder is known. The arrangement is thus introduced into a heating zone, such that the lower end begins to partly soften and the component drawn from the softened part. According to the invention, a pseudo-continuous method for the formation of the restriction in the inner passage of the hollow cylinder on which the core rod is supported, is disclosed, whereby an upper hollow cylinder is fused end on with a lower hollow cylinder to form an axial composite cylinder, a core rod is introduced into the lower hollow cylinder and the axial cylinder composite partly softened and elongated to form the optical component. A drawing bulb extending to the upper hollow cylinder forms, within which the inner passage at least partly collapses with formation of the restriction and the upper cylinder is then separated off from the drawn optical component at a separating plane and then elongated together with a core rod to form an optical component.

Method for production of an optical component from quartz glass

The production of an optical component from quartz glass, by elongation of a coaxial arrangement of a core rod and a hollow cylinder of a given length, is known. The arrangement is thus introduced into a heating zone with a vertical orientation, such that the lower end begins to partly soften and the component is drawn downwards from the softened part. The hollow cylinder has an inner passage, provided with a restriction in the region of the lower end thereof, on which the core rod is supported. Several methods are disclosed for formation of the restriction in which the inner passage () is mechanically machined to a final dimension and, in one version of the method, the restriction in the inner passage () is generated by means of softening the lower end face of the hollow cylinder, swaged against a tool and thus folded inwards with formation of a peripheral bead ring.

Method for production of an optical component made from quartz glass

The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction. The quartz glass blank according to the invention is characterized by the following properties: In the use according to the invention, the quartz glass blank complies with dimensioning rules (2), (3), and (4) in terms of its minimal and maximal hydrogen contents and OH-content, C, C, and C, respectively, with P being the pulse number and &#x3b5; being the energy density (in mJ/cm):[molecules/cm]=1&#xd7;10&#x3b5;,&#x2003;&#x2003;(2)[molecules/cm]=2&#xd7;10&#x3b5;,&#x2003;&#x2003;(3)[wt-ppm]=1,700&#xd7;&#x3b5;[mJ/cm]&#xb1;50.&#x2003;&#x2003;(4)The procedure according to the invention is characterized in that a mixed quartz glass is generated from a first and a second quartz glass by mixing the two quartz glasses in the course of a homogenization treatment.

Quartz glass blank for an optical component, and manufacturing procedure and use thereof

A core glass for making a preform for an optical fiber particularly useful for the transmission of ultraviolet radiation and methods for making the core glass are disclosed. The core glass is obtained by the flame hydrolysis of a silicon compound, deposition of finely granular SiO on a substrate with direct vitrification and formation of a synthetic quartz glass. The quartz glass has a hydrogen content of less than 1&times;10 molecules/cm .

Adjusting the hydrogen content of a preform for an UV-optical fiber

The invention concerns a quartz glass body for an optical component for the transmission of UV radiation with a wavelength of 250 nm and less, especially for a wavelength of 157 nm, as well as a process for the manufacture of the quartz glass body where fine quartz glass particles are formed by flame hydrolysis of a silicon compound, deposited and vitrified. Suitability of a quartz glass as represented by high base transmission and radiation resistance depends on structural properties caused by local stoichiometric deviations, and on the chemical composition. The quartz glass body according to the inventions is distinguished by a uniform base transmission (relative change of base transmission &lE;1%) in the wavelength range from 155 nm to 250 nm (radiation penetration depth of 10 mm) of at least 80%, a low OH content (less than 10 ppm by weight) and a glass structure substantially free from oxygen defect centers. A quartz glass body of this kind is manufactured by a process which allows bulk embedding of hydrogen or oxygen into the glass network in that at least a two stage heat treatment takes place at temperatures ranging from 850&deg; C. to 1600&deg; C. before the vitrification, the last stage comprising sintering at a temperature between 1300&deg; C. and 1600&deg; C. in an atmosphere containing hydrogen or oxygen, or a nonflammable mixture of these substances.

Quartz glass body for optical component and process for manufacture thereof

In a known optical component a cylindrical glass core of synthetic quartz glass contains hydroxyl groups, a maximum 200 wt.-ppm of chlorine, and no dopant in the form of a metal oxide. The glass core is axially enveloped by a glass mantle of doped quartz glass which has a lower refractive index than the glass core. Setting out from this, in order to offer an optical component of quartz glass for broad-band transmission, especially for broad-band spectroscopy, which is characterized by low attenuation over a broad range of wavelengths, it is proposed by the invention that the core glass contain less than 5 wt.-ppm of hydroxyl groups.

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Hanau, Germany

Jan Vydra