Heraeus Quarzglas Gmbh & Co Kg

Heraeus Quarzglas Gmbh

Heraeus Tenevo Gmbh

Shin-etsu Quartz Products Co., Ltd.

Heraeus Tenevo Ag

Heinz Fabian

Stephan Thomas

Johann Leist

Juergen Roeper

Waltraud Werdecker

Shigeru Yamagata

Kyoichi Inaki

Karsten Bräuer

Udo Gertig

Ralf Takke

Rolf G&ouml;bel

Toshikatu Matsuya

Michael Hünermann

Thomas Kayser

Matthias Otter

Uwe Christiansen

Wolfgang Englisch

Achim Hofmann

Bruno Uebbing

Clemens Schmitt

Martin Arndt

Gerhard Schötz

Norbert Treber

Helmut Friedrich

Rainer Köppler

Thomas J Miller

Frank G&auml;nsicke

Karsten Br&auml;uer

Erich Rosin

Jürgen RÖPER

One aspect relates to a light guide comprising a jacket and one or more cores, wherein the jacket surrounds the cores. Each core has a refractive index profile perpendicular to the maximum extension of the core, wherein at least one refractive index nof each refractive index profile is greater than the refractive index nof the jacket. The jacket is made of silicon dioxide and has an OH content of less than 10 ppm, a chlorine content of less than 60 ppm, and an aluminium content of less than 200 ppb. One aspect also relates to a silicon dioxide granulate I, characterized by a chlorine content of less than 200 ppm and an aluminium content of less than 200 ppb, in each case based on the total weight of the silicon dioxide granulate I.

Glass fibers and pre-forms made of homogeneous quartz glass

A method for producing titanium-doped synthetic quartz glass includes: The liquid SiOfeedstock material comprises at least one additional component made of the polyalkylsiloxane D3 having a weight fraction of mD3 and one additional component made of the polyalkylsiloxane D5 having a weight fraction of mD5 at a weight ratio of mD3/mD5 in a range of 0.01 to 1, and the liquid SiOfeedstock material provided is evaporated while maintaining the weight ratio of mD3/mD5 and at least 99% by weight thereof are evaporated to form the gaseous SiOfeedstock vapor.

Method for producing titanium-doped synthetic quartz glass

A method for producing synthetic quartz glass comprises providing a liquid SiOfeedstock material containing mainly octamethylcyclotetrasiloxane D4, vaporizing the SiOfeedstock material into a feedstock vapor, converting the feedstock vapor into SiOparticles, depositing the SiOparticles on a deposition surface while forming a porous SiOsoot body. and vitrifying the SiOsoot body while forming the synthetic quartz glass. To produce large&#x2014;volume cylindrical soot bodies with outer diameters of more than 300 mm of improved material homogeneity. the liquid feedstock material contains additional components comprising hexarnethylcyciotrisilxane D3 and its linear homolog with a weight fraction mD3, dodecamethylcyclohexasiloxane D6 and its linear homolog with a weight fraction mD6, and tetradecamethylcycloheptasiloxane D7 and/or hexadecamethylcyclooctasiloxane D8 and its linear homologs with a weight fraction mD7+. The weight ratio mD3/mD6 is in a range between 0.5 and 500 and the weight fraction mD7+is at least 20 wt. ppm.

Method for producing synthetic quartz glass

A known method for producing synthetic quartz glass comprises the method steps of: forming a stream of a SiOfeedstock material which contains octamethylcyclotetrasiloxane (D4) as the main component which has a reference molecular mass assigned to it, feeding the stream to a reaction zone in which the feedstock material is converted under formation of amorphous SiOparticles by pyrolysis or hydrolysis into SiO, depositing the amorphous SiOparticles on a deposition surface while forming a porous SiOsoot body, and vitrifying the SiOsoot body while forming the synthetic quartz glass. Starting therefrom, to enable the production of large-volume cylindrical soot bodies with outer diameters of more than 300 mm of improved material homogeneity, it is suggested according to the invention that the feedstock material contains additional components in the form of further polyalkylsiloxanes, wherein light polyalkylsiloxanes with a relative molecular mass of less than the reference molecular mass are contained with a weight fraction of at least 50 ppm, and heavy polyalkylsiloxanes with a relative molecular mass of more than the reference molecular mass are contained with a weight fraction of at least 30 ppm.

The present invention relates to a method for producing synthetic quartz glass, comprising the steps of: providing a liquid SiOfeedstock material (), which comprises more than 70% by wt. of the octamethylcyclotetrasiloxane D4, vaporizing the SiOfeedstock material () into a gaseous SiOfeedstock vapor (), converting the SiOfeedstock vapor () into SiOparticles, depositing the SiOparticles on a deposition surface () while forming a SiOsoot body (), vitrifying the SiOsoot body () while forming the synthetic quartz glass. According to the invention it is provided that vaporizing the heated SiOfeedstock material () comprises an injection phase in an expansion chamber () in which the heated SiOfeedstock material () is atomized into droplets, the droplets having a mean diameter of less than 5 pm, preferably less than 2 &#x3bc;m.

Atomizing method for producing synthetic quartz glass

A method for producing synthetic quartz glass comprises providing a liquid SiOfeedstock material containing mainly octamethylcyclotetrasiloxane D4, vaporizing the SiOfeedstock material into a feedstock vapor, converting the feedstock vapor into SiOparticles, depositing the SiOparticles on a deposition surface while forming a porous SiOsoot body, and vitrifying the SiOsoot body while forming the synthetic quartz glass. To produce large-volume cylindrical soot bodies with outer diameters of more than 300 mm of improved material homogeneity, the liquid feedstock material contains additional components comprising hexamethylcyclotrisiloxane D3 and its linear homolog with a weight fraction mD3, dodecamethylcyclohexasiloxane D6 and its linear homolog with a weight fraction mD6, and tetradecamethylcycloheptasiloxane D7 and/or hexadecamethylcyclooctasiloxane D8 and its linear homologs with a weight fraction mD7+. The weight ratio mD3/mD6 is in a range between 0.5 and 500 and the weight fraction mD7+ is at least 20 wt. ppm.

In a known method for the production of a blank mold for optical fibers, a fluorine-doped SiOenveloping glass is produced on a core glass cylinder that rotates about its longitudinal axis, wherein a silicon-containing starting substance is fed to a plasma burner, said substance is then oxidized in a plasma flame assigned to the plasma burner to obtain SiOparticles, the SiOparticles are deposited by layers on the enveloping surface of the cylinder of the core glass cylinder in the presence of fluorine and sintered into the enveloping glass. The invention aims at providing an economical method, which builds upon the above-mentioned method, in order to produce a blank mold from which optical multi-mode fibers () can be obtained. In comparison with fibers () produced according to standard methods, said optical multi-mode fibers are characterized by high initial transmission in the UV wavelength range and good resistance with respect to brief UV radiation, more particularly in the 210-300 nm wavelength range. According to the invention, a plasma flame that irradiates an ultraviolet light having a wavelength of 214 nm with an intensity of at least 0.9 ?W&#x2014;determined on the basis of plasma flame intensity measurement&#x2014;is used for the formation and deposition of the SiOparticles on the core glass.

Method for the production of a blank mold for optical fibers

The aim of the invention is to improve a known quartz glass cylinder for the production of an optical component, comprising an inner drilling, which is mechanically machined to size and provided with an etched structure by means of an etching treatment, subsequent to the mechanical machining, such that in the application thereof for production of pre-forms and optical fibers, few bubbles arise along the boundary surface between core and sleeve. Said aim is achieved, whereby the etched structure comprises striations with a maximum depth of 2.0 mm and a maximum width of 100 &#x3bc;m. A method for production of such a quartz glass cylinder mechanically machined to size is characterized in that the mechanical machining comprises several serial removal processes with successively lower removal depths, whereby after the last removal process the inner drilling has sub-surface striations with a maximum depth of 2 mm and the inner drilling is subsequently subjected to an etching treatment such that an etching removal with a maximum depth of 50 &#x3bc;m is achieved.

Quartz glass cylinder for production of an optical component and method for production thereof

Jacket tubes of synthetically produced quartz glass as a semi-finished product for producing an outer cladding glass layer of an optical fiber are generally known. The invention relates to an improvement of a jacket tube in terms of inexpensive producibility and of suitability as a semi-finished product for optical fibers having a low optical attenuation. According to the invention this object is achieved by a jacket tube in which the quartz glass has a content of metastable OH groups of less than 0.05 wt ppm and a content of anneal-stable OH groups of less than 0.05 wt ppm.

Jacket tube made of synthetically produced quartz glass and optical fibres produced using said jacket tube

In the known method for producing an optical fiber, a coaxial arrangement comprising a core rod and an outer jacket tube is elongated, the coaxial arrangement being supplied in a vertical orientation to a heating zone and being softened therein zonewise, starting with the lower end thereof, and the optical fiber being withdraw downwards from the softened portion, whereby an annular gap existing between core rod and jacket tube is collapsed. Starting therefrom, in order to provided a method which makes it possible to produce optical fibers with a minimum curl and at low costs, the invention suggests that a quartz glass cylinder treated mechanically to its final dimension and having an outer diameter of at least 100 mm should be used as the jacket tube. An optical fiber obtained according to the method is characterized in that without the action of external forces it assumes a radius of curvature of at least 6 mm.

Method for producing an optical fiber and optical fiber

According to a prior art method for producing a cylindrical component comprised of silica glass, a cylinder comprised of a softened silica glass mass is drawn in a predetermined drawing direction along a drawing axis by means of a drawing device which acts upon said cylinder. The aim of the invention is to provide a method which prevents, to the greatest possible extent, warping of the drawn cylinder and other deviations from the ideal cylinder dimensions and to prevent, to the greatest possible extent, the outer surface of the drawn cylinder from being touched. To these ends, the invention provides that the drawing device comprises a plurality of guide elements which are arranged one behind the other along the drawing axis, and which can be displaced independently of one another in a drawing direction and in a direction opposite thereto. At least two of said guide elements which maintain an engaging distance from one another are simultaneously displaced, in a frictionally engaged manner, on the cylinder in a drawing direction and with an identical drawing speed. A device suited for carrying out the inventive method comprises a feed device, a heating zone and a drawing device by means of which a cylinder is drawn along a drawing axis and in a predetermined drawing direction with a controlled drawing speed. The drawing device comprises a number of drawing elements which are arranged one behind the other along the drawing axis and which can be displaced independently of one another in a drawing direction and in a direction opposite thereto.

Method for elongating a cylinder of silica glass

The invention relates to a method for manufacture of a quartz glass preform for an optical fibre consisting of the following steps: preparation of a hollow cylinder made of porous quartz glass which exhibits an inner layer with a doping substance which increases the refractive index of quartz glass and an outer layer surrounding the inner layer, with a lower refractive index, and collapse of the hollow cylinder characterised by collapse of the porous hollow cylinder onto a quartz glass rod containing the doping substance.

Method for the manufacture of a quartz glass preform for an optical fiber

In a known method for producing an SiO blank, SiO particles are formed in a burner flame assigned to a deposition burner and are deposited under the effect of an electrical field on a deposition surface of a carrier rotating about its longitudinal axis, said at least one deposition burner being reciprocated in a predetermined sequence of movement along the developing blank between turn-around points. Starting from said method, in order to obtain blanks of a predetermined, in particular axially homogeneous, density and mass distribution, it is suggested according to the invention that the geometrical shape of the burner flame should be varied by the electrical field in dependence upon the position of the deposition burner during the sequence of movement. An apparatus which is suited for carrying out the method comprises a carrier which is rotatable about its longitudinal axis, a deposition burner for producing SiO particles in a burner flame, a drive device by means of which the deposition burner can be reciprocated along the carrier, and a pair of electrodes which is connected to a source of voltage for producing an electrical field which is operative in the area of the burner flame and which, when viewed along the path of movement of the deposition burner, is locally inhomogeneous or variable in time in dependence upon the position of the deposition burner during the sequence of movement of the deposition burner.

Method for producing an SiO2 blank and apparatus for performing said method

A glass composition to be softened is fed to a heating zone and is shaped continuously into a cylindrical component in a deformation zone, and the cross-sectional geometry of the component is determined. A feed device, a heating device, and a take-off device are provided, and a glass composition is supplied continuously by the feed device to the heating device, where it is softened, the component being formed from the softened glass composition by means of the take-off device under formation of a deformation zone. To produce a component with only slight deviations from the desired cross-sectional geometry and to provide a flexible apparatus suitable for this purpose, the glass composition is locally heated or cooled in at least one deformation area, which extends over only a part of the circumference of the deformation zone, as a function of a determined deviation of the cross-sectional geometry from a nominal geometry. Heating or cooling are provided, which act locally on at least one deformation area, which extends over only a part of the circumference of the deformation zone.

Process and apparatus for the production of a cylindrical component of glass

In a known method for producing an SiO blank, SiO particles are formed in a burner flame of a deposition burner and are deposited under the effect of an electrical field on a substrate. Starting therefrom, in order to indicate a simple and inexpensive method by means of which blanks can be produced with a predetermined, in particular axially homogeneous, mass and density distribution, it is suggested according to the invention that the geometrical shape of the burner flame ( ) is adjusted by the effect of the electrical field ( ) in dependence upon the geometrical parameter of a deposition surface ( ) of the substrate ( ) that is assigned to the burner flame ( ). An apparatus suited for performing the method comprises a substrate, at least one deposition burner for producing SiO particles in a burner flame assigned to the deposition burner, a measuring device for sensing a geometrical parameter in the area of a deposition surface of the SiO blank, and a pair of electrodes connected to a source of voltage for producing an electrical field ( ) which is operative in the area of the burner flame and is adjustable in dependence upon the geometrical parameter of that deposition surface ( ) of the substrate that is assigned to the burner flame ( ).

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Grossostheim, Germany

Heinz Fabian