Abstract: The Ti3+ ions present in Ti-doped silica glass cause a brown staining of the glass, causing inspection of the lens to become more difficult. Known methods for reducing Ti3+ ions in favor of Ti4+ ions in Ti-doped silica glass include a sufficiently high proportion of OH-groups and carrying out an oxygen treatment prior to vitrification, which both have disadvantages. In order to provide a cost-efficient production method for Ti-doped silica glass, which at a hydroxyl group content of less than 120 ppm shows an internal transmittance (sample thickness 10 mm) of at least 70% in the wavelength range of 400 nm to 1000 nm, the TiO2—SiO2 soot body is subjected to a conditioning treatment with a nitrogen oxide prior to vitrification. The blank produced in this way from Ti-doped silica glass has the ratio Ti3+/Ti4+?5×10?4.

Abstract: A method for producing a large quartz-glass pipe is provided. In a first forming step, an intermediate cylinder made of quartz glass and having an intermediate-cylinder wall thickness and outside diameter is formed by using a forming tool and is then cooled. In a second shaping step, at least one length segment of the cooled intermediate cylinder is fed to a heating zone, heated to a softening temperature zone by zone therein, and, while rotating about the longitudinal axis of the intermediate cylinder, shaped into the large quartz-glass pipe having a final wall thickness and outside diameter. The quartz glass is synthetically produced and has an average hydroxyl group content of 10 ppm by weight or less. If the intermediate cylinder is divided into length segments of 1 cm, adjacent length segments have a difference of less than 2 ppm by weight in the average hydroxyl group content thereof.

Abstract: A method for manufacturing quartz glass, wherein (a) an appropriate liquid starting material is evaporated by spraying it into a vertically arranged evaporation chamber, (b) the vaporous starting material is oxidized to form SiO2, and the SiO2 is collected. The method is characterized in that the starting material to be evaporated is sprayed in on the bottom of the evaporation chamber and the vaporous starting material is removed at the top end of the evaporation chamber, wherein the evaporation chamber is designed such that components depositing in the chamber accumulate on the bottom of the evaporator and are sprayed once again, as well as an evaporator for applying the method.

Abstract: One aspect relates to a method for the production of synthetic quartz glass. Moreover, one aspect relates to a polyalkylsiloxane compound, which includes certain specifications with respect to chlorine content, metallic impurities content, and residual moisture, as well as the use thereof for the production of synthetic quartz glass. One aspect also relates to a synthetic quartz glass that can be obtained according to the method of one embodiment.

Abstract: 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.

Abstract: For use as electrode material for a lithium battery, porous templates are impregnated with a carbon feedstock that can be graphitized. This frequently results in only a low thickness of the deposited, graphite-like layer, such that generally several such infiltration and carbonation processes must be carried out consecutively.

Abstract: A known method for producing synthetic quartz glass comprises: (a) reacting a carbonic silicon compound-containing raw material with oxygen in a reaction zone into SiO2 particles, (b) precipitating the SiO2 particles on a sedimentation area by forming a porous SiO2 soot body containing hydrogen and hydroxyl groups, (c) drying the porous SiO2 soot body, and (d) glazing to the synthetic quartz glass by heating the soot body up to a glazing temperature. In order to facilitate cost-efficient production of quartz glass by means of pyrolyzing or hydrolyzing a carbon-containing silicon compound using a carbon-containing raw material, the invention describes the production of a soot body with a carbon content within the range of 1 ppm by weight to 50 ppm by weight.

Abstract: In a known process for drawing a quartz glass strand, SiO2 particles are fed to a melting crucible and softened therein to form a quartz glass mass, and the softened quartz glass mass is pulled vertically downward as a quartz glass strand via a drawing nozzle which is provided in the bottom region of the melting crucible and has a gap-like drawing nozzle opening.

Abstract: One aspect relates to a method for the manufacture of doped quartz glass. Moreover, one aspect relates to quartz glass obtainable according to the method including providing a soot body, treating the soot body with a gas, heating an intermediate product and vitrifying an intermediate product.

Abstract: An optical component made of synthetic quartz glass includes a glass structure substantially free of oxygen defect sites and having a hydrogen content of 0.1×1016 to 1.0×1018 molecules/cm3, an SiH group content of less than 2×1017 molecules/cm3, a hydroxyl group content of 0.1 to 100 wt. ppm, and an Active temperature of less than 1070° C. The optical component undergoes a laser-induced change in the refractive index in response to irradiation by a radiation with a wavelength of 193 nm using 5×109 pulses with a pulse width of 125 ns and a respective energy density of 500 ?J/cm2 at a pulse repetition frequency of 2000 Hz. The change totals a first measured value M193nm when measured using the applied wavelength of 193 nm and a second measured value M633nm when measured using a measured wavelength of 633 nm. The ratio M193nm/M633nm is less than 1.7.

Abstract: A method for producing titanium-doped synthetic quartz glass includes: (A) providing a liquid SiO2 feedstock material that comprises more than 60% by weight of the polyalkylsiloxane D4; (B) evaporating the liquid SiO2 feedstock material to produce a gaseous SiO2 feedstock vapor; (C) evaporating a liquid TiO2 feedstock material to produce a gaseous TiO2 feedstock vapor; (D) converting the SiO2 feedstock vapor and the TiO2 feedstock vapor into SiO2 particles and TiO2 particles, respectively; (E) depositing the SiO2 particles and the TiO2 particles on a deposition surface while forming a titanium-doped SiO2 soot body; (F) vitrifying the titanium-doped SiO2 soot body while forming the synthetic quartz glass, whereby the TiO2 concentration of the synthetic quartz glass is between 5% by weight and 11% by weight.

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 known method for producing a porous carbon body comprises providing a template of inorganic template material which comprises interconnected pores, providing a precursor substance for carbon, infiltrating the pores of the template with the precursor substance, carbonizing the precursor substance and removing the template with formation of the porous carbon product. Starting therefrom, to provide a method which allows a cost-effective production of a porous carbon structure also with thick wall thicknesses, it is suggested according to the invention that precursor substance particles of fusible material and template particles are provided and a powder mixture is formed from the particles, and that the powder mixture is heated before or during carbonization according to method step (d) in such a manner that precursor substance melt penetrates into the pores of the template particles.

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 known method for producing a porous carbon product comprises producing a monolithic template from inorganic matrix material having pores connected to each other, infiltrating the pores of the template with carbon or a carbon precursor substance forming a green body framework containing carbon surrounded by matrix material and calcining the green body framework forming the porous carbon product. In order to provide a method proceeding herefrom which permits cost-effective production of a product from porous carbon, according to the invention the production of the template comprises a soot separation process in which a hydrolyzable or oxidable starting compound of the matrix material is supplied to a reaction zone, therein converted to matrix material particles by hydrolysis or pyrolysis, the matrix material particles are agglomerated or aggregated and formed to the template.

Abstract: Build-up granulation and compaction granulation methods are generally known for producing granules from porous inorganic material. In order to allow a cost-efficient yet also reproducible production of porous granules having a more pronounced hierarchical pore structure, the invention relates to a method comprising the following steps: (a) supplying a feedstock flow to a reaction zone in which the feedstock is converted to material particles by means of pyrolysis or hydrolysis, (b) depositing the material particles on a deposition surface (1a) forming a soot layer (5), (c) thermally hardening the soot layer (5) to form a porous soot plate (5a), and (d) comminuting the soot plate (5a) to form porous granules (13).

Abstract: In a known drawing method for producing a cylindrical component from quartz glass, a quartz glass strand (2) is continuously drawn off from a softened quartz glass composition (13) vertically downwards in the drawing direction (3), a piece (15) with a weight G is detached from the free end of the strand at a time t1 and the cylindrical component is produced from the piece (15). When the piece (15) is detached, there may be a sudden reduction in weight, which leads to fluctuations in the thawing-off control. To counteract this, it is proposed according to the invention that a weight compensating force which acts counter to the drawing direction (3), increases over time and completely or partially compensates for the weight G of the piece (15), is applied to the piece to be detached at a time t0 before t1.

Abstract: 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.

Abstract: It is an object of the invention to provide a synthetic silica glass for a cladding of a core from a fiber laser. The refractive index should be low and there should be no foaming foreign substances. This object is achieved by a synthetic silica glass for an optical element, which contains paramagnetic E? defect centers in an amount that is sufficient to set the absorption coefficient at 215 nm is in the range between 0.001 cm?1 and 2 cm?1; it contains paramagnetic oxygen defect centers in an amount that is sufficient to set the absorption coefficient at 250 nm is in the range between 0.001 cm?1 and 2 cm?1; the OH group concentration is 5 wtppm or less; the viscosity at 1100° C. is in the range between 1×1013.5 poise and 1×1015.5; the total content of metallic elements of Group 3 and Group 13 of the periodic table is 50.000 wtppm or less; and the relative refractive index difference of said synthetic silica glass is in the range between +0.

Abstract: A method for producing synthetic quartz glass comprises providing a liquid SiO2 feedstock material containing mainly octamethylcyclotetrasiloxane D4, vaporizing the SiO2 feedstock material into a feedstock vapor, converting the feedstock vapor into SiO2 particles, depositing the SiO2 particles on a deposition surface while forming a porous SiO2 soot body. and vitrifying the SiO2 soot 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 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.