Abstract: A process for producing a fluorinated quartz glass is described, including providing an SiO2 soot body; reacting the SiO2 soot body with a fluorinating agent having a boiling point of greater than or equal to ?10° C. to obtain a fluorinated SiO2 soot body; and vitrifying the fluorinated SiO2 soot body.

Abstract: A manufacturing apparatus of a porous glass base material for optical fiber includes: a liquid mass flow controller for controlling a flow rate of a raw material liquid of an organic siloxane; a vaporizer for mixing the raw material liquid and a carrier gas to vaporize the raw material liquid to form a mixed gas in which a raw material gas and the carrier gas are mixed; a raw material liquid nozzle for ejecting the raw material liquid into the vaporizer; a carrier gas supply pipe for supplying the carrier gas into the vaporizer; a raw material liquid pipe for introducing the raw material liquid into the raw material liquid nozzle; a burner for combusting the mixed gas together with a combustible gas and a combustion supporting gas to produce SiO2 fine particles; a mixed gas pipe; an open/close valve; and a purge gas supply pipe.

Abstract: An optical fiber preform including a glass material and a refractive index adjusting additive is disclosed. This preform has striae due to difference in concentration of the additive and the striae have concentric refractive index periodicity in at least a part thereof from a radial center of the preform to an outer periphery thereof. The respective striae pitches each indicating a period of the refractive index periodicity increase from the center of the preform to the outer periphery thereof.

Abstract: A method for manufacturing a glass ingot includes preparing a supply system including a gasifier that gasifies a raw material compound and a burner that combusts the gasified raw material compound; adding an oxygen-containing gas to the raw material compound at a plurality of addition places including an upstream addition place located in the gasifier or on an upstream side of the gasifier and a downstream addition place located on a downstream side of the gasifier in which locations of the raw material compound in a flow direction are different in the supply system so as to form a raw material mixture; and adding the oxygen-containing gas at the upstream addition place so that a concentration of oxygen or a concentration of the raw material compound in the raw material mixture is not in a combustible range of the raw material mixture.

Abstract: The invention features methods and diffraction-based devices for the detection of specific analytes. The devices of the invention contain a periodic dielectric multilayer, which allows for the propagation of Bloch surface waves (BSWs) at the surface of the multilayer, thereby increasing the sensitivity of the device.

Abstract: A member is made of titania-doped quartz glass in which striae have a curvature radius of at least 150 mm in a surface perpendicular to an EUV-reflecting surface. The member free of exposed striae and having a high flatness is useful in EUV lithography.

Abstract: A known method for producing synthetic quartz glass comprises the method steps of: forming a stream of a SiO2 feedstock 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 SiO2 particles by pyrolysis or hydrolysis into SiO2, depositing the amorphous 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.

Abstract: The present invention relates to a method for producing synthetic quartz glass, comprising the steps of: providing a liquid SiO2 feedstock material (105), which comprises more than 70% by wt. of the octamethylcyclotetrasiloxane D4, vaporizing the SiO2 feedstock material (105) into a gaseous SiO2 feedstock vapor (107), converting the SiO2 feedstock vapor (107) into SiO2 particles, depositing the SiO2 particles on a deposition surface (160) while forming a SiO2 soot body (200), vitrifying the SiO2 soot body (200) while forming the synthetic quartz glass. According to the invention it is provided that vaporizing the heated SiO2 feedstock material (105) comprises an injection phase in an expansion chamber (125) in which the heated SiO2 feedstock material (105) is atomized into droplets, the droplets having a mean diameter of less than 5 pm, preferably less than 2 ?m.

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 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.

Abstract: There is provided a method for manufacturing a porous glass base material by using a porous glass base material manufacturing burner having an oxidizing gas discharge port. The method includes supplying a gas mixture obtained by blending together an oxidizing gas and an inert gas to the oxidizing gas discharge port at a start of deposition of a glass fine particle, and increasing a flow rate of the oxidizing gas supplied to the oxidizing gas discharge port while decreasing a flow rate of the inert gas supplied to the oxidizing gas discharge port.

Abstract: Provided is a method for manufacturing glass preforms with high yield. In the glass-preform manufacturing method according to the present invention, a glass preform is produced through a fixing step, a deposition step, an extraction step, a vitrification step, and a collapsing step in the enumerated order. At the deposition step, the mean density of the glass soot body deposited on the circumference of the tubular handle 12 is made higher than the mean density of the glass soot body deposited on the circumference of the starting mandrel 11. It is preferable that the longitudinal variation in the mean density of a glass soot body deposited from the start of deposition to the tenth layer of glass particles within the range of ±50 mm from the boundary position between the starting mandrel and the tubular handle be 0.01 g/cc/mm or less.

Abstract: An optical fiber preform manufacturing apparatus includes a booth, a reaction chamber disposed inside the booth, a target member disposed within the reaction chamber, a burner that deposits glass particles on the target member, a partition plate that partitions the internal space of the booth into a first space where the reaction chamber and the burner are disposed and a second space, and that has a plurality of through holes that allows the first space and the second space to communicate with each other, an air supply unit that supplies clean air into the first space; and an exhaust unit that discharges air within the second space.

Abstract: An isothermal, low pressure-based process of depositing material within a substrate has been developed and results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The chemical delivery system, in one arrangement, utilizes rods of solid phase source material (which may otherwise be difficult to obtain in gaseous form). The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.

Abstract: In a known process for producing a quartz glass cylinder, a porous soot tube, which is sintered to form the quartz glass cylinder, is produced by depositing SiO2 particles on an outer cylindrical surface of a support, which rotates about the longitudinal axis thereof and has a layer of silicon carbide (SiC layer). In order on this basis to specify a support having a high resistance to fracture, which firstly can easily be removed and which secondly presents a low risk of contamination for the soot body, the invention proposes that the SiC layer is treated at a high temperature in an oxygen-containing atmosphere before the SiO2 particles are deposited, in such a manner that an SiO2 protective layer having a thickness of at least 0.1 ?m is produced by oxidation.

Abstract: The invention relates to a burner module having a body that is either sintered or photo-cured, and to methods of making such a burner module. The body (110) of the burner (100) is formed from one of a sintered metal, a sintered alloy, a laminated glass ceramic, and a photo-cured polymer. 1 Sintering and photo-curing may be accomplished by irradiating the body with localized heating using a focused energy source, such as a laser. The burner module is resistant to thermal shock and provides a distributed, even stream of a precursor or precursors to be reacted in a flame of the burner module to form soot, which is to deposited on a receptor surface, and may be used for vapor and liquid precursor delivery systems. A soot deposition system having an array of such burner modules and methods of making a fused silica article by depositing soot using the burner modules are also described.

Abstract: The present invention relates to a preform manufacturing method and others for effectively reducing variation in refractive index due to chlorine used in manufacture of an optical fiber preform. The manufacturing method includes a dechlorination step carried out between a point of an end time of a dehydration step and a point of a start time of a sintering step, the dechlorination step being a step of heating a porous preform after dehydrated, in an atmosphere containing no chlorine-based dehydrating agent, for a given length of time while maintaining a temperature lower than a sintering temperature, thereby removing chlorine from the porous preform after dehydrated.

Abstract: There is provided an apparatus for supplying a hydrogen gas to a quartz glass manufacturing apparatus including a burner that generates an oxyhydrogen flame when supplied with the hydrogen gas, where the apparatus includes: a first hydrogen supply system that supplies a hydrogen gas in which isomers are in equilibrium; a second hydrogen supply system that supplies a hydrogen gas in which isomers are out of equilibrium; a flow rate control section that includes: a valve that changes a flow rate of the hydrogen gas to be supplied to the burner; a first flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a heat capacity; and a control section that controls the valve in such a manner that a measured value obtained by the first flow rate measuring section approaches a set value input from outside; a second flow rate measuring section that measures the flow rate of the hydrogen gas to be supplied to the burner by measuring a different factor than the

Abstract: A method for making a high quality optical fiber preform includes: thermally defusing the alkali metal element into the inner side of a silica glass pipe by heating the glass pipe from the outside by a heat source while vapors of alkali metal salt generated by heating an alkali metal salt is supplied to the inside of the glass pipe from an end thereof; collapsing the glass pipe for forming a core rod; and adding a cladding part around the circumference of the core rod. At the start of the thermal diffusion, the alkali metal salt is heated at a temperature for making the vapor pressure of the alkali metal salt to be 0.1 kPa or less, and thereafter the alkali metal salt is heated up to a temperature for making the vapor pressure of the alkali metal salt to be larger than 0.1 kPa.

Abstract: A method of manufacturing an optical fiber preform by depositing glass fine particles onto a surface of a glass rod while the glass rod is reciprocated relative to a plasma torch, including: moving the glass rod in a first direction relative to the plasma torch while the plasma torch is applied to the glass rod and supplied at least with a dopant material and a glass material to deposit the glass fine particles onto the surface of the glass rod, in such a manner that a plasma power is set higher during a first time interval starting from a beginning of the movement of the glass rod in the first direction than during a second time interval starting from an end of the first time interval; and moving the glass rod in a second direction relative to the plasma torch, where the second direction is opposite to the first direction.

Abstract: The present invention provides a quartz glass burner that can enhance the heating power of flame working without unnecessarily increasing the flow of combustion gas and improve the deposition efficiency on depositing glass particles onto a porous glass preform. The quartz glass burner has a large diameter outer tube, and a plurality of small diameter inner tubes enclosed in the outer tube, and a tip of the outer tube has a port defining member defining the outer shape of a combustion gas ejecting port that ejects combustion gas, and the port defining member protrudes from the inner circumference of the outer tube towards the center axis so as to block the outermost area including areas between the outer circumferences of a plurality of inner tubes forming the inner tube row and the inner circumference of the outer tube of the combustion gas flow path.

Abstract: Described is a modular method of making an optical fiber comprising a core and a cladding configured to support and guide a fundamental transverse mode, the cladding including (i) an outer cladding having an index nout less than the index n1 of the core, (ii) an inner cladding having an index n2<nout, (iii) a pedestal having an index n4?nout, (iv) an inner trench disposed between the inner cladding and the pedestal, the inner trench having an index n3<<n4, and (iv) an outer trench disposed between the pedestal and the outer cladding, the outer trench having an index n5<n4 and relatively close to nout. To suppress unwanted HOMs the pedestal is configured to resonantly couple at least one unwanted transverse mode of the core (other than the fundamental mode) to at least one transverse mode of the pedestal.

Abstract: A method for manufacturing quartz glass using a main burner having a multi-tube assembly having a center tube, a first enclosure tube surrounding the center tube, a second enclosure tube surrounding the first enclosure tube, a tubular shell surrounding the multi-tube assembly, and a plurality of nozzles disposed within the tubular shell, a double-tube assembly surrounding at least a forward opening of the main burner includes feeding silica-forming compound to the center tube, a combustion-supporting gas to the first enclosure tube and the nozzles, a combustible gas to the second enclosure tube and the tubular shell, and a combustion-supporting gas to the double-tube assembly, forming oxyhydrogen flame for hydrolyzing or decomposing the silica-forming compound to form silica, depositing the silica on the target, and melting and vitrifying the deposited silica into quartz glass.

Abstract: It is an object of the present invention to provide a copper-containing silica glass which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength of 400 nm or less, and which is excellent in long term stability even in the high output use. The copper-containing silica glass is made to have copper of from 5 wtppm to 200 wtppm, which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength ranging from 160 nm to 400 nm, and in which an internal transmittance per 2.5 mm thickness at a wavelength of 530 nm is 95% or more.

Abstract: A known refraction-sensitive optical fiber comprises a core zone with an index of refraction nK, a jacket zone surrounding the core zone, said jacket zone having an index of refraction nM, and an annular zone made of quartz glass doped with fluorine, said annular zone surrounding the jacket zone and having an index of refraction nF, where nF<nM<nK. 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 (21) 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 (20), said layer having a layer thickness of at least 1 mm and an index of refraction nF<1.

Abstract: A synthetic quartz glass ingot is prepared by vapor phase hydrolyzing or oxidatively decomposing a silica feedstock in a flame to form fine particles of silica, depositing the silica particles on a target and melting and vitrifying the particles to form a synthetic quartz glass ingot on the target while the target is moved back and forth. The method further comprises: (i) continuously feeding the silica feedstock at a predetermined rate, (ii) keeping the flame in constant contact with an overall growing face, (iii) cyclically repeating the back and forth movement of the target at a predetermined speed, and (iv) maintaining the shape of the growing ingot unchanged.

Abstract: A method and apparatus for making an optical fiber preform. The apparatus has an outer wall and an inner wall. The outer wall surrounds the inner wall and the inner wall surrounds an inner cavity of the apparatus. A consolidated glass rod is deposited in the inner cavity after which particulate glass material, such as glass soot, is deposited in the inner cavity around the glass rod. A radially inward pressure is applied against the particulate glass material to pressurize the particulate glass material against the glass rod.

Abstract: 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.

Abstract: A titania and sulfur co-doped quartz glass member is provided. Due to co-doping of titania and sulfur, the quartz glass member undergoes zero expansion at a certain temperature and low thermal expansion over a wide temperature range, and is thus suited for use in a commercial EUV lithography tool. A manufacturing method and an optical member for EUV lithography are also provided.

Abstract: A burner for fabricating an optical fiber preform, which can suppress the adhesion and deposition of glass particles to the front end of the burner without enlarging the burner diameter, is provided. The burner has a first tube, a second tube and a third tube coaxially arranged and define a glass raw material gas port, a sealing gas port, and a burnable gas port by the front end portions thereof, and a plurality of small diameter nozzles arranged between the second tube and the third tube, each of the nozzles arranged on a concentric circle relative to the glass raw material gas port and defines a combustion assisting gas port by the front end portion thereof, the front end portion of the second tube protrudes ahead of that of the first tube, and the front end portion of the third tube protrudes ahead of those of the second tube and each of the nozzles.

Abstract: The present invention relates to a device for manufacturing an optical preform by means of an internal vapor deposition process, said device comprising an energy source and a substrate tube, which substrate tube comprises a supply side for supplying glass-forming precursors and a discharge side for discharging constituents that have not been deposited on the interior of the substrate tube, said energy source being movable along the length of the substrate tube between a point of reversal at the supply side and a point of reversal at the discharge side.

Abstract: A method of producing an optical fiber preform includes preparing a glass preform that has a hole extending in a longitudinal direction formed on one end of the glass preform in such a manner that a length of the hole is equal to or less than half of an entire length of the glass preform, synthesizing a porous glass preform by depositing glass particles on an outer circumference of the glass preform having the hole formed on the end, and sintering the porous glass preform after arranging the porous glass preform in such a manner that the end having the hole formed thereon points downward and the hole is open to the air.

Abstract: Method of making a microstructured optical fiber. Silica glass based soot is deposited on a substrate to form at least a portion of an optical fiber preform by traversing a soot deposition burner with respect to said substrate at a burner traverse rate greater than 3 cm/sec, thereby depositing a layer of soot having a thickness less than 20 microns for each of a plurality of burner passes. At least a portion of the soot preform is then consolidated inside a furnace to remove greater than 50 percent of the air trapped in said soot preform, said consolidating taking place in a gaseous atmosphere containing krypton, nitrogen, or mixtures thereof under conditions which are effective to trap a portion of said gaseous atmosphere in said preform during said consolidation step, thereby forming a consolidated preform which when viewed in cross section will exhibit at least 50 voids therein.

Abstract: A multi-nozzle type burner is used for producing a porous glass preform, the burner having small variations in deposition efficiency with the burner tip being not burned even when axial shift occurs at the concentric multi-tube part of the burner. The present invention provides a burner for producing a porous glass preform with a concentric multi-tube structure, comprising a glass material gas jet port in a center, a plurality of gas jet ports concentrically disposed outside the glass material gas jet port, and small-diameter gas jet ports which are disposed in a line or a plurality of lines concentrically to the glass material gas jet port so as to be enclosed in one of the gas jet ports other than the gas jet ports in the center and at an outermost side, the small-diameter gas jet ports in the same line having an identical focal length.

Abstract: The present invention provides a method for producing a glass preform capable of improving the deposition efficiency of produced glass fine particles to a starting rod or a glass soot body. The method for manufacturing a glass preform includes controlling the temperature of SiCl4 used as a source gas to 100° C. or more, producing glass fine particles having an average outer diameter of 90 nm or more in a flame of a burner for producing glass fine particles, and depositing the glass fine particles on a starting glass rod 13.

Abstract: A method for manufacturing a primary preform for optical fibers using an internal vapor deposition process, including the steps of: i) providing a hollow glass substrate tube having a supply side and a discharge side, ii) surrounding at least part of the hollow glass substrate tube by a furnace, iii) supplying a gas flow, doped or undoped, of glass-forming gases to the interior of the hollow glass substrate tube via the supply side thereof, iv) creating a reaction zone in which conditions such that deposition of glass will take place on the interior of the hollow glass tube are created, and v) moving the reaction zone back and forth in longitudinal direction over the hollow glass substrate tube between a reversal point located near the supply side and a reversal point located near the discharge side of the hollow glass substrate tube.

Abstract: As a precursor to forming a glass sheet, a soot layer is formed on a deposition surface using a roll-to-roll glass soot deposition process. A soot layer-separating device is configured to bring a stream of gas into contact with at least a portion of a free surface of the soot layer. The impinging gas stream affects local thermal expansion stresses at the soot layer/deposition surface interface, which separates the soot layer from the deposition surface.

Abstract: A method for manufacturing an optical fiber base material includes producing glass fine particles through a hydrolysis of a glass material gas in a flame created by an oxidizing gas and a combustible gas.

Abstract: A method and device for manufacturing a preform for optical fibers through chemical deposition on a substrate for deposition arranged vertically is described, comprising a chemical deposition chamber including at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated element constituting a substrate for chemical deposition for the formation of a preform for optical fibers. The chamber includes, moreover, at least one burner which is mobile along a direction Z substantially parallel to said axis Z-Z and adapted to deposit, on said at least one elongated element, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances, said at least one suction element being arranged on the opposite side to said at least one burner with respect to said axis Z-Z and being mobile along said direction Z.

Abstract: The present invention relates to an optical fiber preform fabricating method that makes it possible to implement a reduction in iron impurities at a low cost. The optical fiber preform fabricating method comprises a glass synthesis step for forming a glass region constituting at least a part of the core area of the optical fiber. The glass synthesis step includes a deposition step of depositing glass particles containing the Al-element inside the glass pipe by means of chemical vapor deposition, and a consolidation step of obtaining a transparent glass body from the glass soot body thus obtained. In other words, the deposition step synthesizes glass particles on the inside wall of a glass pipe by feeding raw material gas, in which the content ratio (O/Al) of the O-element and Al-element is 20 or less, into the glass pipe. Furthermore, the consolidation step obtains a transparent glass body from the glass soot body by heating the glass soot body.

Abstract: A method for fabricating a porous silica preform includes the steps of supplying fuel gas for generating an oxyhydrogen flame to a glass synthesizing burner; supplying Gas A containing silicon and Gas B containing fluorine to the burner; synthesizing glass particles; and depositing the glass particles around a starting rod, in which when glass particles are deposited directly on the starting rod, a supply of Gas A and a supply of Gas B supplied to the burner are adjusted so that a ratio of the number of fluorine atoms to the number of silicon atoms in the gas supplied to the burner satisfies the following Formula (1): {(number of F atoms)/(number of Si atoms)}?0.1??(1).

Abstract: A process for producing a porous quartz glass body containing hydrolyzing a metal dopant precursor and an SiO2 precursor in a flame of a burner to form glass fine particles, and depositing and growing the formed glass fine particles on a base material, in which the burner has at least two nozzles, and in which a mixed gas containing (A) a metal dopant precursor gas, (B) an SiO2 precursor gas, (C) one gas of H2 and O2, and (D) one or more gases selected from the group consisting of a rare gas, N2, CO2, a hydrogen halide and H2O, with a proportion of the gas (D) being from 5 to 70 mol %; and (E) the other gas of H2 and O2 of (C), are fed into different nozzles of the burner from each other.

Abstract: 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 SiO2 particles, and the SiO2 particles are deposited on a deposition surface while being directly vitrified. In order to increase the deposition efficiency, the invention provides that the deposition burner (1) focuses the media flow toward the plasma zone (4) 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 (7) is designed so that it is focussed toward the plasma zone (4). The focussing is effected by a tapering (6) of the media nozzle (7).

Abstract: The method of manufacturing porous glass base material for optical fiber includes that flame-hydrolyzing raw materials for glass in oxyhydrogen flame, depositing the generated glass fine particles on a rotating target to form porous glass base material, dehydrating and sintering the porous glass base material to transform into clear glass. The method features, in terms of the surface temperature of said porous glass base material, which changes as the burner used for depositing glass fine particle is moved relatively to said target, the temperature difference between the surface temperature of the porous glass base material touching the burner flame Ta and the surface temperature of the porous glass base material before touching the flame Tb, that is Ta?Tb, is adjusted to be within the range from 200 to 700 degrees centigrade.

Abstract: A known method for producing a cylinder of quartz glass comprises a soot depositing process, in which SiO2 particles are deposited on an elongate carrier rotating about an axis of rotation with formation of a porous, hollow-cylindrical soot body, and a sintering process in which the soot body comprising an inner bore with inner wall, a longitudinal axis, an upper end and a lower end is held suspended in vertical orientation in a furnace, a holding element being provided for holding purposes, which projects from the upper end into the inner bore of the soot body and acts on a bearing provided in the inner bore.

Abstract: A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: A method is provided for forming an optical fiber amplifier. The method comprises providing a composite preform having a gain material core that includes one or more acoustic velocity varying dopants to provide a longitudinally varying acoustic velocity profile along the gain material core to suppress Stimulated Brillouin Scattering (SBS) effects by raising the SBS threshold and drawing the composite preform to form the optical fiber amplifier.

Abstract: An isothermal, low pressure-based process of depositing material within a substrate has been developed, and is particularly useful in forming an optical fiber preform results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The exhaust end of the tube is connected to a vacuum system which is in turn connected to a scrubber apparatus for removal and neutralization of reaction by-products. The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.

Abstract: To provide a method for the inexpensive manufacture of a deposition burner with small manufacturing tolerances for use in the synthesis of quartz glass, and wherein moreover, when the deposition burner is used as intended, the risk of contamination of the quartz glass to be produced is low, the invention suggests the following method steps: (a) providing a start cylinder of quartz glass (40) which is mechanically provided with longitudinal bores (46, 47); (b) elongating the start cylinder with formation of a burner strand (42), the longitudinal bores being shaped as elongated channels extending in parallel with one another; (c) cutting the burner strand into pieces in the form of cylindrical quartz glass blocks (43), each being provided with passage lines extending in parallel with a central axis of the quartz glass block; and (d) manufacturing the deposition burner by using a respective one of such quartz glass blocks as burner head which has a proximal end and a distal end, the passage lines serving the sup

Abstract: A method for forming a silica glass blank includes generating soot using an array of soot producing burners, directing the soot along a first direction onto a bait, collecting the soot on the bait, imparting relative oscillatory motion having a repeat period between the array of soot producing burners and the bait along a second direction orthogonal to the first direction while collecting the soot, and offsetting the relative oscillatory motion by a selected distance along the second direction after each repeat period.

Abstract: Provided are a manufacturing method of an optical fiber base material and an optical fiber base material manufactured in the manufacturing method, the manufacturing method including: a process of combining at least two core base materials 70 by fusion-bonding to produce a single core base material; a process of fusion-bonding a pair of dummy glass rods 61 and 62 at both ends of the core base material 70 to produce a starting glass rod; a process of depositing, at an outer surface of the starting glass rod, glass particles generated by flame hydrolysis, to produce a porous base material 80; and a process of sintering and vitrifying, into transparent glass, the porous base material 80, to produce an optical fiber base material 310 that includes a core portion and a clad portion.