Heraeus Quarzglas Gmbh & Co Kg

Heraeus Tenevo Gmbh

Karsten Bräuer

Richard Schmidt

Andreas Schultheis

Heinz Fabian

Andreas Langner

Clemens Schmitt

Gerhard Schötz

Peter Bauer

Uwe Christiansen

Gerhard Schoetz

Norbert Treber

Rainer Köppler

Paul Bödiger

A quartz glass tube as a semi-finished product for an optical component that has an inner bore extending along a tube center axis for the acceptance of a core rod and a tube wall limited by an inner casing surface and an outer casing surface is already known; within said tube wall an inner region made of a first quartz glass and an outer region made of a second quartz glass with a different index of refraction surrounding the inner region contact one another at a contact surface which runs around the center axis. In order to provide a quartz glass on this basis that facilitates the production of optical components for special applications such as laser-activated optical components in wand or fiber form, the invention states that the contact surface has a non-round course in the radial cross-section and the inner casing surface has a circular course.

Quartz glass tube as a semi-finished product for an optical component

In plasma deposition processes for producing an optical preform according to the POD method, a cladding glass layer composed of fluorine-doped quartz glass is produced by means of a plasma torch on a cylindrical substrate body composed of quartz glass, said substrate body rotating about the longitudinal axis thereof. In this case, the plasma torch performs a reversing relative movement between two turning points (A; B) along the substrate body. In order, proceeding therefrom, to achieve a high fluorine doping in conjunction with a dopant distribution that is as uniform as possible axially, the invention proposes that a heat element has a heating effect on the region of one turning point (A; B) when the plasma torch is situated in the region of the other turning point (B; A).

Plasma deposition process for producing an optical preform with a cladding glass layer of fluorine-doped quartz glass

The invention relates to a plasma deposition process for producing an optical preform, which is characterized by a cladding glass layer having a non-round internal cross-section together with high fluorine doping and axially and radially specified dopant distribution, which in the simplest case is as uniform as possible. For this purpose, a two-stage method is proposed, wherein a substrate body having a non-round cross-section is first reshaped into a coated substrate body having a circular cross-section in that a POD filling layer made of quartz glass having the nominal fluorine concentration is deposited onto a present filling surface and rounded by grinding, and then in the second stage of the method a POD sheathing glass layer made of fluorine-doped quartz glass and having a circular-ring-shaped cross-section is deposited.

Method for producing an optical preform with a POD cladding glass layer

The invention relates to a method for producing a blank mold from synthetic quartz glass by using a plasma-assisted deposition method, according to which a hydrogen-free media flow containing a glass starting material and a carrier gas is fed to a multi-nozzle deposition burner. The glass starting material is introduced into a plasma zone by the deposition burner and is oxidized therein while forming SiOparticles, and the SiOparticles are deposited on a deposition surface while being directly vitrified. In order to increase the deposition efficiency, the invention provides that the deposition burner () focuses the media flow toward the plasma zone () by. A multi-nozzle plasma burner, which is suited for carrying out the method and which is provided with a media nozzle for feeding a media flow to the plasma zone, is characterized in that the media nozzle () is designed so that it is focussed toward the plasma zone (). The focussing is effected by a tapering () of the media nozzle ().

Method and device for producing a blank mold from synthetic quartz glass by using a plasma-assisted deposition method

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

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.

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Bruchköbel, Germany

Karsten Bräuer