Optical Filament Or Fiber Treatment With Fluorine Or Incorporating Fluorine In Final Product Patents (Class 65/DIG16)
  • Patent number: 5746801
    Abstract: A process for producing fluoride glass, including the steps of: introducing a raw material for fluoride glass into a heating vessel; and heating the raw material in the heating vessel, while causing the heating vessel to have a negative internal pressure and introducing an inert gas into the heating vessel, thereby to melt the raw material under heating.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: May 5, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Chie Fukuda, Masashi Onishi, Hiroo Kanamori
  • Patent number: 5454847
    Abstract: A deposition method for vapor deposition of a film of fluorine-containing glass on a substrate in which said substrate is put into contact with fluxs of the vapors of the various constituents of said glass, wherein said vapor fluxs are emitted simultaneously from at least two crucibles, a first crucible containing a host bath and main metal fluorides that constitute said fluorine-containing glass, and at least one second crucible containing dopants constituted by at least one rare earth halide.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: October 3, 1995
    Assignee: Alcatel Alsthom Compagnie Generale d'Electricite
    Inventors: Charles Jacoboni, Brigitte Boulard, Olivier Perrot
  • Patent number: 5401289
    Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: March 28, 1995
    Assignee: British Telecommunications public limited company
    Inventors: Paul W. France, Steven F. Carter, John R. Williams
  • Patent number: 5364428
    Abstract: A glass preform which is used for fabricating an optical fiber, has substantially no bubbles therein and contains sufficient amount of fluorine is produced by a method comprising steps of: forming a porous glass soot body from a glass-forming raw material, removing trapped gas and water from pores of the soot body by heating the soot body under pressure lower than several ten Torr. at a temperature at which the soot body is not vitrified, filling the pores of the soot body with a gas containing SiF.sub.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: November 15, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Yoichi Ishiguro, Akira Urano, Hideo Kakuzen
  • Patent number: 5364434
    Abstract: Glass free of surface carbon deposits, such as carbon film and/or carbon occlusions, and a process for removing such carbon deposits from glass. The process is characterized by the application of a plasma to glass to remove the carbon deposits. The plasma used for this purpose contains active specie which reacts with the carbon deposits to form gaseous carbon products.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: November 15, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Jasbinder S. Sanghera, Pablo C. Pureza, Ishwar D. Aggarwal
  • Patent number: 5360637
    Abstract: A process for the vapor phase deposition of a fluoride containing glass on a substrate, the said fluoride containing glass containing in mole percent with a total of 100%, 30-50 PbF.sub.2, 30-50 GaF.sub.3, 0-30 ZnF.sub.2, 1-5 MF.sub.2 wherein M is Mn or Cd, 1-5 InF.sub.3, 0-10 AlF.sub.3 and 0-10 adjuvant, which involves contacting the substrate with vapors emanating from a molten bath of metallic fluorides comprising a reception bath containing in mole percent with a total of 100%, 9-26 YF.sub.3, 19-38 BaF.sub.2, 35-40 InF.sub.3, 18-25 M'Fe.sub.2 wherein M' is Mn, Cal or Zn and 0-10 adjuvant to which reception bath has been added a sufficient amount of a mixture of PbF.sub.2, GaF.sub.3 and optionally AlF.sub.3. The invention also concerns a vitreous composition deposited on a substrate, thus obtained, which is useful as a waveguide in the infrared.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: November 1, 1994
    Assignee: Centre National de la Recherche Scientifique (CNRS)
    Inventors: Charles P. Jacoboni, Brigitte R. J. Boulard
  • Patent number: 5356448
    Abstract: A method of making a preform for an optical fiber, in which method a plurality of layers of fluoride glass are deposited inside a support tube (10); said layers (14) are deposited by laser ablation in a controlled atmosphere using a target (12) having the composition of said glass, which target is moved back-and-forth parallel to the axis of said tube, the temperature of the enclosure (1) in which said ablation is performed being not greater than the vitreous transition temperature Tg of said glass.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: October 18, 1994
    Assignee: Alcatel N.V.
    Inventors: Jean-Pierre Dumas, Christian Belouet
  • Patent number: 5350433
    Abstract: In a method of manufacturing a cylindrical part from glass, especially but not exclusively fluorinated glass, a vertical cylindrical cavity is lined with a porous material and its inside dimensions are a few tens of microns greater than those of the part. A cylindrical pedestal constituting a support for the part slides in the cavity. An initial seed mass constituted from the glass is provided on the pedestal. The seed mass is heated until it melts and a gas is injected permanently into the porous material in order to maintain between them and the molten seed mass a layer of gas a few tens of microns thick to prevent any contact. The molten seed mass is fed continuously from the top of the cavity with the powder constituents of the glass and the pedestal is lowered as the cylindrical part is formed from the seed mass.
    Type: Grant
    Filed: January 27, 1993
    Date of Patent: September 27, 1994
    Assignee: Alcatel N.V.
    Inventor: Pascal Baniel
  • Patent number: 5334232
    Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: August 2, 1994
    Assignee: British Telecommunications Public Limited Company
    Inventors: Paul W. France, Steven F. Carter, John R. Williams
  • Patent number: 5306322
    Abstract: The present invention providesa process for the dehydrating and purifying treatment by heating a porous glass preform for an optical fiber comprising passing the porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere comprising an inert gas and a silicon halogenide gas;a process for the fluorine-doping treatment by heating a porous glass preform for an optical fiber comprising passing a porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere comprising a fluorine compound gas and an inert gas; anda process for the vitrifying treatment by heating a porous glass preform for an optical fiber comprising passing the preform, which has been previously dehydrated and purified, through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere gas.
    Type: Grant
    Filed: July 24, 1992
    Date of Patent: April 26, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shinji Ishikawa, Yuichi Ohga, Ichiro Tsuchiya, Hiroo Kanamori, Hiroshi Yokota, Michihisa Kyoto
  • Patent number: 5294240
    Abstract: This invention pertains to optical waveguides which includes waveguides of ll shapes and sizes, preforms, and optical fibers made from the preforms, and to a method for making waveguides devoid of a physical interface.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: March 15, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Jasbinder S. Sanghera, Pablo C. Pureza, Ishwar D. Aggarwal
  • Patent number: 5277889
    Abstract: Metal halide compositions of enhanced purity are produced by vapor phase deposition via reactions involving organometallic starting materials in a process wherein a carbon getter is provided in the reaction zone and/or adjacent the developing metal halide deposit. The carbon getter reduces carbon contamination in the product which can result from side decomposition reactions involving the organometallic starting materials.
    Type: Grant
    Filed: May 13, 1985
    Date of Patent: January 11, 1994
    Assignee: Corning Incorporated
    Inventors: Joseph M. Power, Ahmad Sarhangi
  • Patent number: 5262365
    Abstract: Rare earth element doped silica glass according to the invention is prepared by doping silica-based glass co-doped with a rare earth element and aluminum additionally with fluorine and has excellent physical properties including remarkable light emission characteristics and an excellent capability of being fused with other silica-based glass. Such doped silica glass provides high amplification gains and a wide wavelength bandwidth and therefore can be used as a material for manufacturing miniaturized optical devices. Particularly, since the manufacturing process adapted to produce rare earth element doped silica glass according to the invention does not involve crystallization that normally characterizes the type of doped silica glass under consideration, the obtained doped silica glass is transparent and totally free from air bubbles.
    Type: Grant
    Filed: December 5, 1991
    Date of Patent: November 16, 1993
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Akira Oyobe, Kazunori Nakamura, Nobuyuki Kagi, Yasumasa Sasaki
  • Patent number: 5259856
    Abstract: A heating furnace for heating a porous preform made of fine particles of quartz base glass for an optical fiber which comprises a heater and a muffle tube positioned inside the heater to separate a heating atmosphere from the heater, wherein the muffle tube body consists of highly pure carbon and an inner wall and an outer wall of the body is coated with a carbon material selected from the group consisting of pyrolytic graphite and solid-phase carbonized glassy carbon.
    Type: Grant
    Filed: June 1, 1992
    Date of Patent: November 9, 1993
    Assignee: Sumitomo Electric Industrial, Ltd.
    Inventors: Yuichi Ohga, Shinji Ishikawa, Hiroo Kanamori, Ichiro Tsuchiya, Hiroshi Yokota
  • Patent number: 5256178
    Abstract: A method for manufacturing optical fibers from halide glass is provided. The method includes the steps of drawing a glass mass into a fiber in a dry gas atmosphere which contains a drying agent. In a further step of the process, an OH band which may still be present can be reduced by treating the fiber with a gaseous drying agent.
    Type: Grant
    Filed: February 10, 1993
    Date of Patent: October 26, 1993
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hartmut Schneider, Armin Staudt
  • Patent number: 5256605
    Abstract: Suitable starting materials for the manufacture of a heavy metal fluoride glass composition are mixed with solid xenon fluoride as the fluoridizing reagent, after which the mixture is heated to temperatures between 200.degree. and 400.degree. C. in an inert atmosphere for a time which suffices to bring about fluoridation of the starting materials. The intermediate product thus obtained is melted thereby forming a stable glass composition of a high purity and a high transparency. The method can be carried out in a simple manner in a furnace which need not be gastight.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: October 26, 1993
    Assignee: U.S. Philips Corp.
    Inventors: Emmanuel W. J. L. Oomen, Anne-Marie A. Van Dongen, Hendrik Veenvliet
  • Patent number: 5226940
    Abstract: A process for producing optical fibers of high tensile strength, wherein the fiber is pulled from a glass mass of halide glass and includes surrounding the fiber and mass with a dry gas atmosphere containing a drying agent which reacts with moisture and this dry gas atmosphere includes fluorine-containing agents, in particular NF.sub.3, as the drying agent.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: July 13, 1993
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hartmut Schneider, Armin Staudt
  • Patent number: 5221309
    Abstract: A method for producing a glass preform, which method comprises forming a soot preform of glass fine particles comprising SiO.sub.2 by flame hydrolysis or solution hydrolysis of a starting glass material and sintering the soot preform in an atmosphere containing at least SiF.sub.4 to obtain a glass preform which is free from an increase in absorption due to impurities and has sufficiently low attenuation of light transmission.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: June 22, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Minoru Watanabe, Hiroo Kanamori
  • Patent number: 5217516
    Abstract: A refractive index profile in a glass article is easily controlled by heating a solid or hollow cylindrical glass soot preform in an atmosphere comprising a fluorine-containing compound under such conditions that a partial pressure of the fluorine-containing compound is changed as the heating proceeds so as to control a fluorine concentration in a radial direction of the optical glass article.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: June 8, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoichi Ishiguro, Hiroo Kanamori, Akira Urano, Michihisa Kyoto
  • Patent number: 5203898
    Abstract: Disclosed is a method of forming a glass tube doped with boron and fluorine. A B.sub.2 O.sub.3 -doped tubular porous preform is heated, and a fluorine-containing gas is flowed into its aperture. The temperature is sufficiently high to cause the fluorine-containing gas to decompose and form fluorine which dopes the preform. Also flowed into the aperture is a sufficient amount of BF.sub.3 to prevent fluorine from reacting with the B.sub.2 O.sub.3 in the porous preform and forming a B.sub.2 O.sub.3 -depleted region near the aperture surface. The particles are then fused to form a fluorine-containing dense glass tube.
    Type: Grant
    Filed: December 16, 1991
    Date of Patent: April 20, 1993
    Assignee: Corning Incorporated
    Inventors: Norman W. Carpenter, Alan J. Morrow, Donald R. Young, Jr.
  • Patent number: 5203899
    Abstract: A glass preform which is used for fabricating an optical fiber, has substantially no bubbles therein and contains sufficient amount of fluorine is produced by a method comprising steps of: forming a porous glass soot body from a glass-forming raw material, removing trapped gas and water from pores of the soot body by heating the soot body under pressure lower than several ten Torr. at a temperature at which the soot body is not vitrified, filling the pores of the soot body with a gas containing SiF.sub.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: April 20, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Yoichi Ishiguro, Akira Urano, Hideo Kakuzen
  • Patent number: 5201920
    Abstract: A method for manufacturing optical fibers from halide glass is provided. The method includes the steps of drawing a glass mass into a fiber in a dry gas atmosphere which contains a drying agent. In a further step of the process, an OH band which may still be present can be reduced by treating the fiber with a gaseous drying agent.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: April 13, 1993
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hartmut Schneider, Armin Staudt
  • Patent number: 5185021
    Abstract: In a method of manufacturing a preform for a nonoxide glass fiber, cladding and core glass materials are placed in a cylinder of an extrusion apparatus such that ground end faces of the respective cladding and core glass materials are in contact with each other and such that the cladding glass material is located adjacent a molding section of the extrusion apparatus. The cladding and core glass materials are heated within inert-gas atmosphere, to their respective temperatures equal to or below their respective sag points and equal to or above their respective crystallization start temperatures. An extrusion punch of the extrusion apparatus is pushed within the atmosphere, to extrude the cladding and core glass materials through a molding nozzle in the molding section while the cladding and core glass materials are in fusible contact with each other, thereby forming the preform of a core and cladding structure.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: February 9, 1993
    Assignee: Hoya Corporation
    Inventors: Kiyotaka Miura, Toshiharu Yamashita
  • Patent number: 5163987
    Abstract: A method for producing a glass preform for use in the fabrication of an optical fiber, which comprises adding fluorine to a soot preform in an atmosphere comprising a fluorine-coating compound at a temperature at which the soot preform is in the porous state and then keeping or inserting it in an atmosphere containing a fluorine-containing compound at a higher temperature to vitrify it to form a glass preform, from which glass preform, an optical fiber homogeneously containing fluorine is fabricated.
    Type: Grant
    Filed: March 6, 1992
    Date of Patent: November 17, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoichi Ishiguro, Michihisa Kyoto, Hiroo Kanamori
  • Patent number: 5160521
    Abstract: A method for fabricating defect-free optical fiber preforms without light scattering defects such as core-clad interface bubbles, core-clad crystalline inclusions and core glass crystals involves first forming a cladding glass shell preferably by rotational casting, then separately melting core glass inside a cylindrical crucible and quenching using metallic quenching blocks to prevent crystal formation in the core glass, next heating the core containing crucible to the core glass softening point and also heating the cladding tube containing mold to the glass transition temperature of the cladding glass, then placing the cladding tube containing mold inside the core glass crucible and pushing it downwardly with high pressure so that the softened core glass is forced into the cladding glass tube, and finally the preform is annealed to remove thermal stress. Subsequently, the preform is drawn into optical fibers using conventional technology.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: November 3, 1992
    Inventor: Danh C. Tran
  • Patent number: 5158587
    Abstract: A method for producing a glass preform for use in the fabrication of an optical fiber, which includes the steps of forming a glass soot preform from a glass-forming raw material and heating the soot preform in an atmosphere containing SiF.sub.4 under a pressure higher than 2 atm. for a period of time sufficient to add fluorine during the time between the formation of the soot preform and the vitrification of it, fluorine is added at a high rate and in a larger amount.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: October 27, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Akira Urano, Yoichi Ishiguro, Minoru Watanabe
  • Patent number: 5154745
    Abstract: A method of fabricating preforms for making optical fibers by drawing, in which a silica deposit, including a doping agent, is formed in successive layers inside a silica-based tube (1) from a chemical vapor containing a gaseous compound of silicon, oxygen, and a gaseous compound of an element for doping the silica, with the composite tube then being subjected to collapsing so as to cause the empty axial zone (3), the tube hollow, to disappear. The silica of the initial tube is then eliminated, by removal, after which a recharge of silica (5) is made around the remaining cylinder (4) by plasma torch deposition from a gas comprising oxygen and a halogen derivative of silica.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: October 13, 1992
    Assignee: Alcatel Alsthom Compagnie Generale d'Electricite
    Inventor: Christian Le Sergent
  • Patent number: 5147435
    Abstract: Crystallization of a fluoride glass article is suppressed by treating the surface(s) of the fluoride glass article with a solution of a fluorine-containing alkali metal compound or a fluorine-containing ammonium compound such as, e.g., LiPF.sub.6, NaBF.sub.4 or NH.sub.4 BF.sub.4, in a nonaqueous solvent such as, e.g., ethanol, N,N-dimethylformamide or acetonitrile. The treatment can be made at room temperature.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: September 15, 1992
    Assignee: Central Glass Company, Limited
    Inventors: Yoshinori Kubota, Akira Sakanoue, Yasushi Kita
  • Patent number: 5145508
    Abstract: A method for preparing a homogenous fluoride glass containing high purity BaF.sub.2 through the CVD process using a gaseous mixture containing a barium .beta.-diketonate complex service as a first starting material and represented by the following general formula (1) of: ##STR1## where (i) R and R' are each --C(CH.sub.3).sub.3 ; or (ii) R is CH.sub.2 CH.sub.2 CH.sub.3 and R' is --C(CH.sub.3).sub.3 ; or (iii) R and R' are each CF.sub.3 ;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent. Further provided is a process for preparing a perform for a fluoride optical fiber which is low in transmission loss, by depositing the fluoride glass over the interior wall of a cylindrical tube or the wall of rod-like glass substrate through the CVD process following by collapsing.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: September 8, 1992
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazuo Fujiura, Yasutake Ohishi, Michiya Fujiki, Terutoshi Kanamori, Shiro Takahashi
  • Patent number: 5145507
    Abstract: A glass preform is produced by forming a glass soot composite body having a core portion consisting of a solid glass and a peripheral portion consisting of a porous glass mass, removing trapped gas and water from pores of the soot composite body by heating the soot composite body under a pressure lower than several ten Torr. at a temperature at which the porous glass mass is not vitrified, filling the pores in the porous glass mass of the soot composite body with a gas containing SiF.sub.4, the partial pressure of which is a function of the desired specific difference of refractive index, thus uniformly adding fluorine to the soot glass mass, and vitrifying the fluorine-added soot glass mass into a transparent glass mass to form a glass preform.
    Type: Grant
    Filed: January 14, 1991
    Date of Patent: September 8, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Yoichi Ishiguro, Akira Urano, Hideo Kakuzen
  • Patent number: 5139550
    Abstract: A fused coupler is formed from two twisted optic fibers (2, 3) of fluoride glass by heating them in the slot (18) of a temperature-controlled heater (15) in a shroud (14) containing an oxygen-free atmosphere. The glass of the fibers may be ZBLAN glass in which case the temperature is 323.degree. C..+-.10.degree. C. In an alternative embodiment the shroud is dispensed with and inert gas (nitrogen) is injected into a hole in the slot (18).
    Type: Grant
    Filed: October 30, 1990
    Date of Patent: August 18, 1992
    Assignee: British Telecommunications public limited company
    Inventors: Simon T. Nicholls, Michael Scott
  • Patent number: 5127929
    Abstract: An optical waveguide preform is fabricated by inserting a rod inside a tube and collapsing the tube. The inner diameter of the tube is adjusted before inserting the rod to provide a predetermined gap width between the inner surface of the tube and the outer surface of the rod. The gap width is selected as a function of the cross sectional area of the tube in order to minimize core eccentricity in the finished waveguide.
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: July 7, 1992
    Assignee: Alcatel N.V.
    Inventors: Robert Gunther, Ulrich Siemers, Manfred Wittmann
  • Patent number: 5106401
    Abstract: The present invention providesa process for the dehydrating and purifying treatment by heating a porous glass preform for an optical fiber by passing the porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere containing an inert gas and a silicon halogenide gas;a process for the fluorine-doping treatment by heating a porous glass preform for an optical fiber by passing a porous glass preform through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere containing a fluorine compound gas and an inert gas; anda process for the vitrifying treatment by heating a porous glass preform for an opticla fiber by passing the preform, which has been previously dehydrated and purified, through a muffle tube having a SiC layer at least on its inner surface at a high temperature under an atmosphere gas.
    Type: Grant
    Filed: June 28, 1990
    Date of Patent: April 21, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shinji Ishikawa, Yuichi Ohga, Ichiro Tsuchiya, Hiroo Kanamori, Hiroshi Yokota, Michihisa Kyoto
  • Patent number: 5093880
    Abstract: An optical fiber cable free from a generation of a microbent during manufacturing, and in which an impregnation of hydrogen and/or water to a cladding is prevented, and having high electrical conduction, tolerance to heat and mechanical strength, and a process for making same. The optical fiber cable includes a silica based glass optical fiber including a core and a cladding, a thin carbon coating formed on an outer surface of the optical fiber, and an electrically conductive coating formed on an outer surface of the carbon coating. The carbon coating functions as a layer for preventing the impregnation of hydrogen and/or water to the optical fiber, and the conductive coating functions as a heat tolerance member, a conductive member, and a mechanical support member. The carbon coating is preferably formed as an amorphous carbon layer.
    Type: Grant
    Filed: August 27, 1990
    Date of Patent: March 3, 1992
    Assignee: Furukawa Electric Co., Ltd.
    Inventors: Akira Matsuda, Akira Iino, Ryotomo Sirakawa
  • Patent number: 5090980
    Abstract: A method of producing glass bodies having regions with different optical refraction, including a basic body and a coating layer which is sintered onto the basic body, covers the basic body at least partially and is made of glass, which as it is doped, has an index of refraction differing from that of the glass of the basic body. The starting material for producing the cladding on the basis of pulverulent ceramic material is deformed into a self-supporting, unsintered porous green body, is dried and submitted to a cleaning procedure in a heated gas phase. The coating layer to be bonded onto the basic body is melted into glass in a subsequent combined doping/sintering procedure in a gas phase containing the doping agent at a temperature in the range from 1150.degree. to 1500.degree. C. and is sintered onto the basic body.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: February 25, 1992
    Assignee: U.S. Philips Corp.
    Inventor: Rolf Clasen
  • Patent number: 5078768
    Abstract: Defect-free fluoride glass materials are made by hot isostatic pressing (HIP) of a fluoride glass. The process may be used to manufacture preforms or bulk fluoride glass. The external pressure applied during HIP squeezes bubbles from the glass and permits the use of a wider range of working temperatures than ordinarily available, thereby reducing crystallization defects.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: January 7, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Ishar D. Aggarwal, Barry B. Harbison
  • Patent number: 5076824
    Abstract: A mandrel (12) that is used for supporting a glass soot cylinder during consolidation into anoptical fiber preform is coated by chemical vapor deposition with a material selected from the group consisting of pyrolytic graphite and pyrolytic boron nitride.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: December 31, 1991
    Assignee: AT&T Bell Laboratories
    Inventor: Thomas J. Miller
  • Patent number: 5071460
    Abstract: Provided is a process for preparing a homogeneous fluoride glass containing high purity BaF.sub.2 through the CVD process characterized in that the used gaseous mixture comprising: a barium .beta.-diketonate complex serving as a first starting material and represented by the following general formula (1) of: ##STR1## wherein R is an alkyl group having 1 to 7 carbon atoms, R' is a substituted alkyl group having fluorine atoms substituting hydrogen atoms and represented by C.sub.n F.sub.2n+1 where n is an integer of from 1 to 3;a gaseous or vaporizable compound of the metallic element constituting said fluoride glass, the gaseous or vaporizable compound serving as a second starting material; and a fluorine-containing gas serving as fluorinating agent.
    Type: Grant
    Filed: March 1, 1989
    Date of Patent: December 10, 1991
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazuo Fujiura, Yasutake Ohishi, Michiya Fujiki, Terutoshi Kanamori, Shiro Takahashi
  • Patent number: 5069701
    Abstract: A fluoride glass is prepared by depositing a solid including a metal fluoride on a heated substrate, from a gaseous mixture of a nonmetallo-organic compound, carbon dioxide, and a source of carbonyl fluoride. The nonmetallo-organic compound contains the metallic cation of the metal fluoride bonded to an organic species through an electronegative element such as oxygen, but not directly to a carbon atom. The carbon dioxide, or optionally another species reactive with carbon to produce a gas, oxidizes solid carbon and other reduction products of the organic compound that could otherwise be present in the deposited metal fluoride to impair optical properties of the fluoride glass. The carbonyl fluoride, supplied by the gas itself or by reactants that produce the gas, reacts with the nonmetallo-organic compound without producing water, which would otherwise degrade the glass purity.
    Type: Grant
    Filed: February 23, 1990
    Date of Patent: December 3, 1991
    Assignee: Hughes Aircraft Company
    Inventors: Ricardo C. Pastor, Luisa E. Gorre
  • Patent number: 5055120
    Abstract: Improved fluoride glass optical fibers are produced by a process introducing several improvements in the production of fluoride glass preforms and the drawing of fibers therefrom. Reduced bubble formation and crystallization are obtained by vertically spinning a fluoride glass melt within a glass cladding tube at a high rotational speed, or alternatively, pouring a flouride glass core melt into a cladding tube while slowly raising the mold from an inclined position to a vertical position, or alternatively, introducing a core tube inside a cladding tube. The production of fibers is enhanced if at least one production phase, i.e., preform formation or fiber drawing, is conducted in an atmosphere containing reactive gases that scavenge molecules that could otherwise react with, hydrolyze and oxidize the fluoride glass. The disclosure also describes several devices uniquely useful in the process of the present invention.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: October 8, 1991
    Assignee: Infrared Fiber Systems, Inc.
    Inventors: Danh C. Tran, Reza Mossadegh, Nicholas Garito, Mohamad Farid
  • Patent number: 5055121
    Abstract: An optical fiberglass preform having fluorine selectively added to its cladding is produced by:depositing soot of quartz glass on a pipe from starting member by using burners for synthesizing glass soot to form a porous glass preform consisting of a core porous glass body a peripheral portion of which has a larger bulk density than the other portion and a cladding porous glass body,heating said porous glass preform in a dehydration atmosphere while supplying dehydration gas through the pipe form starting member andheating and vitrifying the dehydrated porous glass preform in an atmosphere containing a fluorine-containing compound.
    Type: Grant
    Filed: July 27, 1990
    Date of Patent: October 8, 1991
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroo Kanamori, Yoichi Ishiguro, Gotaro Tanaka
  • Patent number: 5053068
    Abstract: A method for producing a glass preform for use in the fabrication of an optical fiber, including the steps of forming a glass soot preform from a glass-forming raw material and heating the soot preform to vitrify it, the soot preform being heated in an atmosphere comprising SiF.sub.4 under pressure higher than 1 atm. for a period of time sufficient to add fluorine, between the formation of the soot preform and the vitrification of it, fluorine being added at a high rate and in a large amount.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: October 1, 1991
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Akira Urano, Yoichi Ishiguro, Minoru Watanabe
  • Patent number: 5039325
    Abstract: A fluorine-doped silica soot cylinder (11) is consolidated by containing it within an encapsulation structure (29) within a furance (21). The atmosphere within the encapsulation structure is kept substantially stagnant during the consolidating, and the volume enclosed by the encapsulation structure (29) is only slightly greater than the volume of the soot cylinder (11). A gap (52) between the volume enclosed by the encapsulating structure and the furnace is kept small enough to impede gas flow to a sufficient extent that the atmosphere within the encapsulating structure (29) is substantially stagnant during consolidation. During consolidation, fluorine concentration within the encapsulation structure (29) is uniformly distributed within the soot cylinder (11).
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: August 13, 1991
    Assignee: AT&T Bell Laboratories
    Inventors: Thomas J. Miller, Douglas W. Monroe, David A. Nicol, David B. Steele
  • Patent number: 5026409
    Abstract: A preform for preparation of optical fibers is prepared by inserting a rod of a higher index of refraction fluoride glass into the bore of a hollow cylinder of a lower index of refraction fluoride glass fiber. This preform precursor is processed to collapse the hollow cylinder inwardly to form a composite preform having a high-refractive index core and a low-refractive index casing. The preparing of the glasses and processing to a preform are accomplished in a reactive environment that reacts and removes oxygen and hydrogen containing species from the glass, the reactive environment being, for example, Cl.sub.2, CCl.sub.4, SF.sub.6, BF.sub.3, CF.sub.4, or the decomposition products of a liquefied solid fluorocarbon. The preform is then drawn to an optical fiber.
    Type: Grant
    Filed: January 3, 1989
    Date of Patent: June 25, 1991
    Assignee: Hughes Aircraft Company
    Inventors: M. Robinson, Antonio C. Pastor, Ricardo C. Pastor
  • Patent number: 5022904
    Abstract: A refractive index profile in a glass article is easily controlled by heating a solid or hollow cylindrical glass soot preform in an atmosphere comprising a fluorine-containing compound under such conditions that a partial pressure of the fluorine-containing compound is changed as the heating proceeds so as to control a fluorine concentration in a radial direction of the optical glass article.
    Type: Grant
    Filed: June 13, 1990
    Date of Patent: June 11, 1991
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoichi Ishiguro, Hiroo Kanamori, Akira Urano, Michihisa Kyoto
  • Patent number: 5015281
    Abstract: A new, simplified method of fabricating optically transparent fluoride glasses containing ZrF.sub.4 and/or HfF.sub.4 has been developed which relies on a high vacuum pre-treatment for surface dehydration, melting in a rigorously inert argon atmosphere, and incorporation of a nonvolatile metallic oxidant in the melt such as InF.sub.3 and SnF.sub.4. Previous method for making these glasses have relied on either addition of ammonium bifluoride into the batch materials, or melting in an oxidizing atmosphere (so-called reactive atmosphere processing or RAP); both of these latter techniques have significant drawbacks.
    Type: Grant
    Filed: March 6, 1990
    Date of Patent: May 14, 1991
    Assignee: GTE Laboratories Incorporated
    Inventors: Bruce T. Hall, Leonard J. Andrews, Robert C. Folweiler
  • Patent number: 4979971
    Abstract: A method for producing a glass preform for an optical fiber is disclosed. The method comprises forming a soot preform of glass fine particles comprising SiO.sub.2 by flame hydrolysis or solution hydrolysis of a starting glass material and sintering the soot preform in an atmosphere containing at least SiF.sub.4 to obtain a glass preform which is free from an increase in absorption due to impurities and has sufficiently low attenuation of light transmission.
    Type: Grant
    Filed: January 29, 1990
    Date of Patent: December 25, 1990
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Michihisa Kyoto, Minoru Watanabe, Hiroo Kanamori
  • Patent number: 4978376
    Abstract: A crystalline metal halide optical fiber having a two or a three layer structure is provided. The core consists of relatively small crystals. A crust surrounds the core and has the same composition but consists of relatively large crystals. Optionally, an optical outer crust surrounds the inner crust and has a different composition from the inner crust but has generally the same sized crystals. The differing crystal sizes can be produced from a preform by extruding a crystal at a low uniform temperature at a relatively high speed.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: December 18, 1990
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kenichi Takahashi, Noriyuki Yoshida
  • Patent number: 4973345
    Abstract: Halide fibres are protected by coatings up to 2 .mu.m thick of chalcogenide glasses, eg glasses based on compounds of S, Se or Te with Ge or As. The coatings are deposited on the fibre preform by ion deposition sputtering. Preferably the preform is ethced by directing a stream of inert ions at it. Most suitably the etching immediately precedes the coating.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: November 27, 1990
    Assignee: British Telecommunications Public Limited Company
    Inventor: Paul W. France
  • Patent number: H1259
    Abstract: A process for producing long length fluoride glass preforms, by producing a fluoride glass rod of core glass, overcoating the core glass rod with fluoride cladding glass to form a core/clad unit, and overcoating the core/clad unit with an oxide glass overclad.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: December 7, 1993
    Inventors: Ishwar D. Aggarwal, Daniel Brower, Grant Lu