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.

Abstract: An improved suspension-cum-holding device for an optical fiber preform 21 comprising a cylindrical body 22 consisting of a closed top end 23 and open bottom end 24 is disclosed, wherein the closed top end 23 is provided with a securing means 25 capable of securing the suspension-cum-holding device 21 in the furnace, the cylindrical body 22 being provided with an opening 26 towards the closed top end 23, characterized in that the opening 26 extends rearward to form a cylindrical hollow body 27 which is provided with two openings 28 and 29 in its lower surface, wherein the openings 28 and 29 extend downwards respectively to form cylindrical bodies 28a and 29a, wherein the cylindrical body 28a and cylindrical body 29a join and merge with each other at a point 30 forming a body 31, wherein the cylindrical body 27 is provided with a ball support means 32 at the interface of cylindrical body 27 and cylindrical body 29a which is capable of supporting the handle ball 11B provided on the preform handle 11 of the optic

Abstract: Disclosed is a method for fabricating an optical fiber preform. The method includes: (a) growing a first soot preform on a starting member along a lengthwise direction of the starting member by a soot deposition; (b) dehydrating the first soot preform; (c) sintering the dehydrated first soot preform, to obtain a first glassed optical preform; and (d) elongating the first optical fiber preform by heating the first optical fiber with a heat source that excludes hydrogen, wherein the first glassed optical fiber is elongated by means of only a heat source that excludes the use of hydrogen.

Abstract: Disclosed are a method for fabricating an optical fiber preform and a method for fabricating an optical fiber using the optical fiber preform. The method for fabricating the optical fiber preform including the steps of: (a) growing a first soot preform on a starting member by a soot deposition; (b) dehydrating the first soot preform; (c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform; (e) growing an over-clad soot layer on the first optical fiber preform by soot deposition to obtain a second soot preform; and (f) sintering the second soot preform so as to obtain a second optical fiber preform which is glassed, wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc, and the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

Abstract: Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine.

Abstract: On the basis of a known process for the production of a preform for an optical fiber for optical data transmission technology, the productivity of the process for the production of complex refractive index profiles is to be improved by providing a quartz glass substrate tube which exhibits different doping in radial direction, introducing a core glass made of synthetic quartz glass into the substrate tube and covering the substrate tube with a jacket tube. A substrate tube suitable therefor is also being provided which tube requires less core glass material for the production of the preform, whether during the internal deposition or for the core glass rod in the rod-in-tube technique.

Abstract: A glass tube for use in an optical fiber preform is produced by applying a first soot on an end face of a starting member to form an elongated, porous cylindrical soot core having a first density, and applying a second soot including SiO2 on the periphery of the soot core to form a porous soot cladding having a second density greater than that of the soot core at the periphery of the core. The core and the cladding are later heated together at a temperature sufficient for sintering to form a core glass and a cladding glass. Because the soot core collapses at a greater rate than the soot cladding during sintering, the core glass separates or delaminates radially from the cladding glass. The core glass is then removed from the surrounding cladding glass, and the latter is treated to provide a high purity glass tube suitable for use as part of an optical fiber preform.

Abstract: An object of the present invention is to provide an optical fiber manufacturing method and an optical fiber in which an increase in the transmission loss is suppressed by preventing hydroxyl group from entering near the core portion. This invention provides a method for manufacturing an optical fiber 10 including forming a glass pipe 16 by applying a ring portion 15 on the inner face of a starting pipe 14 as a starting material, inserting a glass rod 13 that becomes a central core portion 11 and a depressed portion 12 into the inside of the glass pipe 16, integrating the glass pipe 16 and the glass rod 13 by collapse to form a glass body 17, forming a preform 10a by providing a jacket portion 18 outside the glass body 17, and drawing the preform 10a, wherein the thickness of the starting pipe 14 is set in a range from 4 mm to 8 mm.

Abstract: A plurality of glass particles synthesizing burners are arranged at a predetermined burner interval opposite to a rotating starting rod. The starting rod and the glass particles synthesizing burners are relatively parallely reciprocally moved, and the soot deposition is conducted. A reciprocating speed v(mm/minute), axis rotating speed r (rpm), and burner interval L (mm) are set so that a value A expressed by the expression A=(r/v)×L is in a range 40?A?8.

Abstract: The present invention provides a method of fabricating rare earth doped preforms and optical fibers by a combination of modified chemical vapor deposition (MCVD) process and solution doping technique said MCVD process is used to develop matched or depressed clad structure inside a silica glass substrate tube followed by deposition of porous silica soot layer containing GeO2, P2O5 or such refractive index modifiers by the backward deposition method for formation of the core and presintering the deposited particulate layer by backward pass with flow of GeCl4 and/or corresponding dopant halides, soaking the porous soot layer into an alcoholic/aqueous solution of RE-salts containing codopants such as AlCl3 in definite proportion, drying, oxidation, dehydration and sintering of the RE containing porous deposit and by collapsing at a high temperature to produce the preform followed by drawing the fibers by known technique to produce fibers with suitable core-clad dimensions and geometry.

Abstract: A dehydration and consolidation furnace and a dehydration and consolidation method in which gas in a chamber does not leak to a furnace body room and gas in a furnace body room does not leak into a chamber is provided. A furnace of one embodiment of this invention has first muffle tube 3 and second muffle tube 4. The second muffle tube 4 is arranged coaxially around the first muffle tube 3. An optical fiber preform is arranged in this furnace. During the dehydration and consolidation process the pressure of the intermediate room 10 is set lower than a pressure inside the first muffle tube and outside the second muffle tube, and a gas supply and exhaust of the intermediate room 10 are performed independent of the gas supply and exhaust of the first muffle tube and a furnace body room.

Abstract: A method of making an optical waveguide preform includes forming a preform including a first portion and a second radial portion, wherein the second portion includes a dopant, and wherein the first portion exhibits a density greater than the second portion. The method further includes stripping at least a portion of the dopant from the second portion. In a preferred embodiment, the stripped dopant has migrated in a previous processing step.

Abstract: The doped silica core region of a core rod for an optical fiber preform is protected against unwanted fluorine doping during fluorine doping of the outer silica layer by selectively consolidating the core region prior to fluorine doping. Due to dopants in the core region, the soot in the core region consolidates before the soot in the outer undoped region. This inherent property allows the entire core rod to be heated prior to fluorine doping resulting in selective partial consolidation and preventing fluorine doping of the doped center core region. The process time required may be reduced by using incremental fluorine doping. In the incremental doping process the doping step is separated into a deposit step, where “excess” fluorine is deposited on the silica particles, and a drive-in step where atomic fluorine is distributed into the silica particles. The drive-in step is conveniently combined with the sintering or consolidation step to further enhance the efficiency of the doping process.

Abstract: The present invention relates to a method for the manufacture a body from a thermoplastic plastic with a three-dimensionally structured surface, wherein the molding is carried out directly from a master made of glass coated with metal oxide, without the deposition of further coatings on the surface of said master. The invention also relates to bodies manufactured with this method from a thermoplastic featuring a three-dimensionally structured surface as well as to planar optical structures likewise manufactured with this method for generating evanescent-field measuring platforms and to the use thereof.

Abstract: The doped silica core region of a core rod for an optical fiber preform is protected against unwanted fluorine doping during fluorine doping of the outer silica layer by selectively consolidating the core region prior to fluorine doping. Due to dopants in the core region, the soot in the core region consolidates before the soot in the outer undoped region. This inherent property allows the entire core rod to be heated prior to fluorine doping resulting in selective partial consolidation and preventing fluorine doping of the doped center core region. The process time required may be reduced by using incremental fluorine doping. In the incremental doping process the doping step is separated into a deposit step, where “excess” fluorine is deposited on the silica particles, and a drive-in step where atomic fluorine is distributed into the silica particles. The drive-in step is conveniently combined with the sintering or consolidation step to further enhance the efficiency of the doping process.

Abstract: Disclosed is an optical fiber article for receiving pump radiation of a first wavelength for amplifying or generating radiation of a second wavelength. The optical fiber article includes a core for propagating light of the second wavelength. The core has a first index of refraction and includes a rare earth material. A cladding surrounds the core and has a second index of refraction that is less than the first index of refraction. The outer circumference of the cladding can include a plurality of sections, where the plurality of sections includes at least one substantially straight section and one inwardly curved section. The optical fiber article can also include at least one outer layer surrounding the cladding, where the index of refraction of the outer layer is less than the second refractive index. Methods for producing the optical fiber article are also disclosed, as well as methods for providing a preform for drawing such an optical fiber article.

Abstract: Embodiments of the invention include a method for making optical fiber having reduced aging or hydrogen aging loss over the life of the fiber and optical fiber systems including such optical fibers. The method includes the steps of dehydrating an optical fiber glass core rod in a first environment including oxygen and at least one of chlorine-containing gases, fluorine-containing gases and carbon monoxide; and adjusting the oxygen stoichiometry of the first environment so that it is neither oxygen-rich nor oxygen-deficient. Improved silicon-oxygen stoichiometry during one or more preform manufacturing steps reduces the amount of Si defects generated in the optical fiber preform. Also, deuterium exposure of optical fiber drawn from the preform reduces the likelihood of having atomic defects such as Si defects in the optical fiber that, over time, attract and bond with hydrogen atoms to form molecules that contribute to increased water absorption loss.

Abstract: To provide a method for producing a glass particle deposit and a method for producing a glass preform, in which outer diameter variation of the glass particle deposit can be reduced to thereby improve quality. A flow rate of clean gas (CG) introduced into a container potion 10 is limited to thereby prevent the outermost layer of a glass particle deposit 20 from being locally cooled and reduce variation in bulk density in the longitudinal direction of the glass particle deposit 20, that is, outer diameter variation and breakage.

Abstract: The present invention is a method of making a lithography photomask and photomask blank. The method of making the lithography photomask and photomask blank includes providing a silicon oxyfluoride glass tube having an OH content less than 50 ppm. The method further includes cutting the silicon oxyfluoride glass tube, flattening the silicon oxyfluoride glass tube, and forming the flattened cut silicon oxyfluoride glass tube into a photomask blank having a planar surface. The present invention includes a glass lithography mask preform. The glass lithography mask preform is a longitudinal silicon oxyfluoride glass tube that has an OH content≦10 ppm, a F wt. % concentration≧0.5 wt. %.

Abstract: A process produces a glass overcladding tube from a silica gel body. The process includes passing the gel body through a hot zone under conditions that cause partial sintering of the gel body and repassing the gel body through the hot zone under conditions that further sinter the gel body into a glass overcladding tube.

Abstract: In respect of a method for manufacturing a preform of an optical fiber, the method comprises the steps of forming a porous glass preform by accumulating glass particles, preparing a container made of a quartz glass, which is formed by heating the quartz glass with an electric furnace, providing a dehydration gas and an inert gas to the container, heating the container to which dehydration gas and inert gas is provided and dehydrating and sintering the porous glass preform by inserting the porous glass preform into the container, which is heated.

Abstract: The invention relates to the field of processes for manufacturing optical fiber preforms. This is a process for manufacturing optical fiber preforms that includes a step of drawing the preform with a draw ratio that remains constant for the same preform and may vary from one preform to another depending on their respective mean diameters so as to reduce the variation in mean diameter between preforms or else a process for manufacturing optical fiber preforms that includes a step of compressing the preform with a compression ratio that remains constant for the same preform and may vary from one preform to another depending on their respective mean diameter so as to reduce the variation in mean diameter between preforms.

Abstract: Disclosed is a method for controlling a heat treatment in the process of fabricating a high purity silica glass via a sol-gel process using a low temperature heater having an inhalation line and an exhaust line. Accordingly, the method includes the steps of (a) identifying whether or not the diameter of the exhaust line is varied; (b) controlling the mass flow of the process gas according to the changed diameter of the exhaust line in step (a); (c) measuring an exhaust gas velocity discharged through the exhaust line; (d) comparing the exhaust gas velocity measured in the step (c) with the exhaust gas velocity after the scale of the exhaust line is varied; and, (e) repeating steps (b)-(d) if the comparison result in step (d) is different.

Abstract: 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 ≦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.

Abstract: The invention involves fabricating a ceramic tube, e.g., a silica overcladding tube, with very little bow, e.g., about 0.3 mm per meter or less. In particular, the invention involves securing the tube by a handle that both allows the tube to hang plumb during treatment, and also is capable of deforming during such heat treatment to maintain the plumb arrangement.

Abstract: A method for producing an optical fiber preform starting with a first-generation target typically comprising pure silica. A plasma torch deposits an annular region of doped silica to form an intermediate structure. The intermediate structure is drawn down to a second-generation target and another annular region of doped silica is deposited. The process is repeated a plurality of times until an Nth generation target is formed. The deposition optionally employs repeated cycles of depositing a plurality of layers of silica at a high traversal rate without sintering, followed by periodic sintering. In a further embodiment, stabilizer bars extending out from the plasma coils improve distribution of the deposition material. Another embodiment injects the source gas into a particular region of the plasma for control of soot deposition.

Abstract: Methods for producing high purity fused silica (HPFS) glass having desired levels of dissolved hydrogen are provided. The methods involve measuring the level of hydrogen in the cavity of the furnace used to produce the glass and controlling the pressure within the furnace and/or gas flows to the furnace's burners so that the measured concentration has a desired value. In this way, the level of dissolved hydrogen in the glass can be controlled since, as shown in FIG. 3, there is a direct correlation between the hydrogen concentration in the cavity atmosphere and level of dissolved hydrogen in the glass.

Abstract: A method and apparatus are disclosed for the manufacture of an optical fiber preform having incorporated therein a comparatively high concentration of rare earth dopant material, and which thus can be drawn and processed into an optical fiber having low numerical aperture, low core attenuation, and high pumping power absorption. The high concentrations of rare earth dopant material are accomplished through either the “hybrid vapor processing” (HVP) method or a “hybrid liquid processing” (HLP) method, each capable of being practiced in combination or independently of one another. The HVP method involves the vaporization of a rare earth halogen by the exposure thereof to a sufficiently elevated temperature, independently, or contemporaneously with the transport of the resultant rare earth halogen laden vapor, into a glass forming oxidation reaction zone on a flowing stream of essentially an unreactive inert gas, such as helium.

Abstract: An optical fiber preform suspending and supporting apparatus able to prevent deformation of a pin placed in a high temperature environment and able to support a porous optical fiber preform without adversely influencing supports of the pin and without causing inclination relative to the vertical line of a main shaft, wherein a movable connector is fitted into an enlarged-diameter portion of the lower end of a main shaft, this enlarged-diameter portion is connected with the movable connector by a pin so that the movable connector is able to swing around the pin, a holding portion including a supporting portion is formed integrally at the bottom of the movable connector to hold an enlarged-diameter portion of the upper end of a starting preform, and the diameter of the pin is in the range of 20% to 50% of the outside diameter of the enlarged-diameter portion of the lower end of the main shaft, and an optical fiber processing apparatus including the same.

Abstract: Embodiments of the invention include a method for making optical fiber having reduced aging or hydrogen aging loss over the life of the fiber and optical fiber systems including such optical fibers. Improved silicon-oxygen stoichiometry during one or more preform manufacturing steps reduces the amount of Si defects generated in the optical fiber preform. Also, deuterium exposure of optical fiber drawn from the preform reduces the likelihood of having atomic defects such as Si defects in the optical fiber that, over time, attract and bond with hydrogen atoms to form molecules that contribute to increased water absorption loss. The inventive method produces optical fibers with improved transmission characteristics, e.g., optical fibers made by methods according to embodiments of the invention have transmission loss at 1385 nanometers that is less than 0.33 dB/km and the aging loss increase thereafter is less than 0.04 dB/km.

Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: A method for fabricating fluorine doped, silica based glass and fiber by depositing a layer of high purity silica soot on a core rod while rotating the core rod places the rod of pure fused silica or doped fused silica and silica soot in a furnace having a lining of Al2O3, elevates the temperature in a fluorine rich atmosphere to establish the proper differential in the indices of refraction between the core start rod and the deposited layer, and heats the resulting rod at consolidation temperatures in an atmosphere of helium to form a preform. The apparatus includes a furnace having a lining of high purity alumina that is resistant to chemical etching and change normally due to the fluorine and chlorine.

Abstract: An invention that relates to arrays, to methods and devices for producing arrays and to methods and devices for using arrays is described. In a particular aspect the invention relates to methods in which array members are aligned in a bundle and the bundle then is sectioned across the alignment to produce replicate arrays. In a further particular aspect the invention relates to arrays of analyte binding reagents. In another particular aspect the invention relates to micro-arrays.

Abstract: Disclosed is a method of making a hydrogen resistant optical waveguide fiber. The soot preform is heated and then immersed in a GeCl4 gas. A reduced metal species is thus incorporated into the glass soot prior to sintering or consolidation of the soot preform. A hydrogen absorption band around 1530 nm is substantially eliminated from waveguides made from a precursor gas treated preform.

Abstract: A method an apparatus for continuously producing optical waveguide fiber and preforms. A continuous supply of core cane is provided to a walled deposition chamber upon which glass soot is deposited to form a soot preform. The preform is passed through an aligned drying, consolidation and draw chambers from which an optical fiber may be drawn. In one embodiment, a plurality of burners are positioned at different radial distances from a longitudinal axis of the cane in the deposition chamber. One or more environmental seal(s) are provided to prevent process gasses or contaminants from flowing into or between the chambers.

Abstract: A method for sintering a porous-glass material to form a glass base material, which is a base material for an optical fiber, comprising: preparing a ring heater having an opening, through which the porous-glass material passes, for heating the porous-glass material; selecting the porous-glass material having an outer diameter (d) within a predetermined range, the predetermined range being determined based on an inner diameter (D) of the opening of the ring heater; and heating the porous-glass material in an atmosphere of dehydration gas and inert gas with the ring heater.

Abstract: Based on a known process for the manufacture of opaque quartz glass, by mixing SiO2 particles and an additive which is volatile at a melting temperature, forming a body and melting said body with an advancing melt front forming in the body, it is proposed according to the invention that in order to reduce the danger of contamination, a body (1) be formed with an inner bore (6) and be heated in such a manner that the melt front (10) advances from the inner bore (6) to the outside. The article of pure opaque quartz glass according to the invention has high resistance to temperature change, high mechanical strength and good chemical durability. It is distinguished by an opening (6) enclosed by an inner wall (9), with an inner SiO2 surface layer (15) having a layer thickness ranging from 30 mm to 500 mm and a density of at least 2.15 g/cm3.

Abstract: An optical article having a rare earth doped, fluorinated aluminosilicate glass core composition consisting essentially, in mole %, of: SiO2 0-90 GeO2 0-90 Na2O 0-25 Li2O 0-10 K2O 0-25 Rb2O 0-25 Cs2O 0-25 Al2O3 5-40 Ga2O3 5-40 RE2(1)O3 0-40 RE2(2)O3 0-1  Er2O3 0.

Abstract: A dehydration and consolidation furnace and a dehydration and consolidation method in which gas in a chamber does not leak to a furnace body room and gas in a furnace body room does not leak into a chamber is provided. A furnace of one embodiment of this invention has first muffle tube 3 and second muffle tube 4. The second muffle tube 4 is arranged coaxially around the first muffle tube 3. An optical fiber preform is arranged in this furnace. During the dehydration and consolidation process the pressure of the intermediate room 10 is set lower than a pressure inside the first muffle tube and outside the second muffle tube, and a gas supply and exhaust of the intermediate room 10 are performed independent of the gas supply and exhaust of the first muffle tube and a furnace body room.

Abstract: High purity direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive direct deposit vitrified silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a dry direct deposit vitrified silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: A sintered dense glass, alumina-doped optical fiber preform is stretched and is then heated to a temperature of 1490-1495° C. to remove bubbles without causing crystallization. Thereafter, the stretched glass body is either drawn directly into an optical fiber or overclad and then drawn into a fiber.

Abstract: Disclosed is a method of making a photonic crystal using a combination of extruding and drawing techniques. The method is contemplated as being capable of producing both two and three dimensional crystals due to the maturity and diversity of extruding and drawing technology. The method allows the drawing of relatively large photonic crystals and is flexible enough to provide a periodic array of channels or filaments as the crystal features. After the extruding step or steps and before the step of heating and drawing, a plurality of elongated extruded bodies can be bundled and drawn as a unit.

Abstract: Disclosed is an apparatus and method for sintering an over-jacketing tube in the zone sintering phase of an optical fiber preform fabrication process using a sol-gel process. The sintering apparatus includes: a processing tube; a gel tube assembly connected to a top rotation cap positioned at the top opening of the processing tube and being rotated at a predetermined rate, a ceramic pin extending downwardly from the center axis of the rotation cap, and a gel tube suspended from the bottom of the ceramic pin and suspended along the same axle of the processing tube; and a movable furnace initially positioned at the bottom of the processing tube and translating in a vertical direction along the processing tube for thermally treating the gel tube.

Abstract: Disclosed is an optical waveguide fiber having a compressive outer layer that includes TiO2 in the SiO2 matrix glass. The compressive outer layer includes crystalline structures containing TiO2 that are predominately rutile. Also disclosed is a method for making an optical waveguide fiber having a compressive outer layer. The compressive outer layer can contain an additional metal oxide that is preferentially lost from the outer layer, instead of the TiO2, during the drying and consolidation step.

Abstract: An optical article having a rare earth doped, fluorinated aluminosilicate glass core composition consisting essentially, in mole %, of:______________________________________ SiO.sub.2 0-90 GeO.sub.2 0-90 Na.sub.2 O 0-25 Li.sub.2 O 0-10 K.sub.2 O 0-25 Rb.sub.2 O 0-25 Cs.sub.2 O 0-25 Al.sub.2 O.sub.3 5-40 Ga.sub.2 O.sub.3 5-40 RE.sub.2 (1)O.sub.3 0-40 RE.sub.2 (2)O.sub.3 0-1 Er.sub.2 O.sub.3 0.001-5 Yb.sub.2 O.sub.3 0-5 PbO 0-15 RO 0-20 ZnO 0-10 ZrO.sub.2 0-2 TiO.sub.2 0-2 Nb.sub.2 O.sub.5 0-10 Ta.sub.2 O.sub.5 0-10 P.sub.2 O.sub.5 0-5 B.sub.2 O.sub.3 0-15 As.sub.2 O.sub.3 0-10 Sb.sub.2 O.sub.3 0-20 Na.sub.2 Cl.sub.2 0-10 Bi.sub.2 O.sub.3 0-5, and ______________________________________up to 15 weight % fluorine in the form of at least one of a fluorinated component of the glass composition and a batch constituent selected from a group consisting of at least one of AlF.sub.3, REF.sub.3, NH.sub.5 F.sub.2, NaF, Na.sub.2 SiF.sub.6, Na.sub.3 AlF.sub.

Abstract: Disclosed is a synthetic silica-glass fabricating method in which the doping of chlorine into silica glass made by using a flame hydrolysis or thermal oxidation is increased. The process comprises the steps of producing a porous deposit of silica-glass particles through treatment of gaseous silicon compounds by the flame hydrolysis or the thermal oxidation process; and consolidating the porous deposit by a heat treatment in an atmosphere including an inert gas and silicon tetrachloride (SiCl.sub.4) gas.

Abstract: The present invention relates to a single-mode optical fiber having a configuration which enables lowering of dispersion slope while securing a sufficient MFD. This single-mode optical fiber has a refractive index profile in which an indent with a sufficient width is provided at the center of its core region. In particular, this indent satisfies the following relationship:a.multidot.(.DELTA.n.sub.2 -.DELTA.n.sub.1)/(b.multidot..DELTA.n.sub.2).gtoreq.0.04when the first core portion in the single-mode optical fiber has a mean relative refractive index difference of .DELTA.n.sub.1 with respect to the cladding portion and an outer diameter of a while the second core portion has a mean relative refractive index difference of .DELTA.n.sub.2 with respect to the cladding portion and an outer diameter of b.

Abstract: An essentially cylindrical porous blank is formed by the deposition of SiO.sub.2 particles onto the lateral cylindrical surface of a cylindrical mandrel, rotating around its longitudinal axis; this blank is provided with a holding element of quartz glass in the form of a hollow body, which surrounds a section of the mandrel and which is at least partially embedded in the area of one of the ends of the blank. The blank is then sintered. In order to securely support even heavy blanks without complicated holding devices, the holding element is fused into the area of at least one of the ends of the blank during the deposition process by the maintenance of a high temperature.

Abstract: A dispersion compensating fiber is provided which is capable of reducing the birefringence of the core caused in spinning to suppress an increase in polarization mode dispersion due to the birefringence of the core even though the surface of the core rod is ground to shape the profile of the core during manufacturing. A silica glass cladding 2 doped with fluorine is disposed to surround a silica glass core 1 doped with germanium. The variation in circumferential concentration of germanium at the periphery of the core 1 is set at 0.05% or smaller in relative refractive index difference value.

Abstract: A solid or hollow cylindrical heat-resistant substrate having a tapered shape is rotated about its axis, the degree of tapering being essentially constant along the entire length. The substrate has an outer diameter in the range of 20 mm to 500 mm and a length in the range of 500 mm to 5,000 mm. A mother material body made of porous quartz glass is formed on the outer surface of the substrate by chemical deposition, and vitrified by heating while holding it vertically with the larger outer-diameter side of the heat-resistant substrate positioned downward. Alternatively the heat-resistant substrate is extracted from the mother material body and a heat-resistant tapered body with a taper similar to that of the substrate is inserted into the hole left after extraction in the central region of the mother material body. The mother material body is vitrified starting at the lower end with the larger outer-diameter side positioned downwardly.