Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
  • C03B37/01—Manufacture of glass fibres or filaments
  • C03B37/012—Manufacture of preforms for drawing fibres or filaments
  • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
  • C03B37/01413—Reactant delivery systems
  • C03B37/0142—Reactant deposition burners
  • C03B37/01426—Plasma deposition burners or torches
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
  • C03B37/01—Manufacture of glass fibres or filaments
  • C03B37/012—Manufacture of preforms for drawing fibres or filaments
  • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
  • C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
  • C03B37/01807—Reactant delivery systems, e.g. reactant deposition burners
  • C03B37/01815—Reactant deposition burners or deposition heating means
  • C03B37/01823—Plasma deposition burners or heating means
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
  • C03B37/01—Manufacture of glass fibres or filaments
  • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
  • C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
  • C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B2201/00—Type of glass produced
  • C03B2201/06—Doped silica-based glasses
  • C03B2201/30—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi
  • C03B2201/40—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn
  • C03B2201/42—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn doped with titanium

Definitions

• the present invention relates to a process for manufacturing an optical fiber by hot drawing of an assembly consisting of an outer sleeving tube in which a bar made partially or totally of synthetic silica has been engaged.
• Parameter n characteristic of the susceptibility of fibers to corrosion, drawn from dynamic fatigue measurements, can be brought to values greater than 50, while it is of the order of 20 for fibers of pure silica.
• a known doping process consists in covering an unvitrified preform manufactured by external deposition of a layer of additional silica also unvitrified containing up to 20% in molar ratio of titanium dioxide. This preform must then be dried and vitrified before being finally drawn into an optical fiber several tens of kilometers in length and mechanically reinforced by the presence of surface doping of titanium dioxide.
• Certain optical fibers in particular single-mode fibers, can be manufactured according to methods which consist in depositing appropriately doped silica inside a tube which is then constricted into a bar, then in engaging this bar in the inside of an outer tubular sleeve.
• This assembly constitutes a composite preform from which the optical fiber is made by hot drawing.
• This composite preform does not lend itself to doping with ti ⁇ tane dioxide as it is practiced on monoblock preforms, so that to date, the fibers produced according to this process could not be treated with titanium dioxide so that their resistance to corrosion is increased.
• the present invention proposes to overcome this drawback.
• said titanium dioxide is deposited in the vapor phase using a plasma torch.
• This titanium dioxide is preferably obtained by oxidizing a volatile or transportable compound in the gas phase of titanium in said plasma torch.
• This compound can be a halide such as titanium tetrachloride.
• the titanium dioxide is advantageously deposited and vitrified at the same time as the silicon oxide or silica.
• the molar level of titanium dioxide is between 2 and 4-0% of that of silica and preferably approximately equal to 10% of this rate.
• FIG. 1 schematically illustrates a first known phase of the process, consisting in producing a standard preform, according to the internal deposition process MCVD (Modified Chemical Vapor Deposition).
• FIG. 2 illustrates a new phase which consists in doping an external tubular sleeve by means of titanium dioxide with direct vitrification of the deposit obtained,
• FIG. 3 represents the assembly phase of the standard preform shrunk into a bar inside the tubular sleeve
• FIG. 4 schematically illustrates the operation which consists in stretching this composite assembly to form said modified fiber.
• a component which is in the form of a bar 10 obtained from a silica tube 11 which has been coated internally with synthetic silica before being shrunk.
• This interior deposition operation is activated by a heat source 12, which can be an oxyhydrogen torch, producing a temperature of approximately 1700 ° C. inside the tube, while the latter is traversed simultaneously by a first current 13 d oxygen having bubbled through a bath of silicon tetrachloride 14 and by a second stream 15 of oxygen having bubbled through a bath of germanium tetrachloride 16.
• This process is known under the name of MCVD (Modified Chemical Vapor Deposition).
• This bar 10 can also be obtained by vitrification of a cylinder made entirely of synthetic silica and in both cases, this synthetic silica is doped so as to constitute an optical guiding structure in the central part of the bar.
• the second phase of the process is represented by FIG. 2.
• This phase is new and consists in depositing on the outer surface of a tubular sleeve 20 a vitrified layer of silica doped with titanium.
• This deposition is carried out by means of a plasma torch 21 supplied on the one hand, with pure oxygen through a conduit 22 and on the other hand, with oxygen or argon charged with silicon tetrachloride brought in through conduit 23 and oxygen or argon charged with titanium tetrachloride brought by a pipe 24.
• the plasma torch is associated with a high frequency generator 25 •
• This phase of This process leads to the production of a tubular sleeve 30 doped externally with titanium dioxide.
• the bar 10 and the sleeve 30 are as ⁇ to form a composite preform 31 which serves as a raw material during the drawing and manufacturing of fibers.
• Said stretching device comprises a stretching tower on which the composite preform 4-1 is mounted and an oven 42 allowing the temperature of this preform to be raised to approximately 2200 ° C.
• a first device 43 for measuring the diameter of the fiber makes it possible to provide information to a motor 44 which drives a drum 45 for winding the optical fiber 46 in order to adjust the winding speed to maintain the fiber diameter in prescribed standards.
• a device 4-7 makes it possible to deposit acrylates on the peripheral surface of the fiber in formation.
• An ultraviolet radiation station 48 ensures the polymerization of the acrylates.
• a second measurement device 49 makes it possible to control the diameter of the fiber including its acrylic coating.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Plasma & Fusion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Manufacture, Treatment Of Glass Fibers (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9413575

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Family Cites Families (12)

• 1991
  • 1991-06-05 FR FR9106908A patent/FR2677349B1/fr not_active Expired - Fee Related
• 1992
  • 1992-06-04 JP JP4509745A patent/JPH06500530A/ja active Pending
  • 1992-06-04 EP EP92910829A patent/EP0541752A1/de not_active Withdrawn
  • 1992-06-04 US US07/971,753 patent/US5337585A/en not_active Expired - Fee Related
  • 1992-06-04 WO PCT/CH1992/000108 patent/WO1992021629A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events