WO2003004426A1 - Procede de fabrication d'une preforme de fibre optique - Google Patents

Procede de fabrication d'une preforme de fibre optique Download PDF

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Publication number
WO2003004426A1
WO2003004426A1 PCT/JP2002/006804 JP0206804W WO03004426A1 WO 2003004426 A1 WO2003004426 A1 WO 2003004426A1 JP 0206804 W JP0206804 W JP 0206804W WO 03004426 A1 WO03004426 A1 WO 03004426A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical fiber
fiber preform
cladding
remaining
clad
Prior art date
Application number
PCT/JP2002/006804
Other languages
English (en)
Japanese (ja)
Inventor
Shunichirou Hirafune
Tomio Abiru
Original Assignee
Fujikura Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2001206279A external-priority patent/JP2003020239A/ja
Priority claimed from JP2001224808A external-priority patent/JP2003040636A/ja
Application filed by Fujikura Ltd. filed Critical Fujikura Ltd.
Publication of WO2003004426A1 publication Critical patent/WO2003004426A1/fr

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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
    • C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
    • C03B37/01225—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
    • C03B37/01228—Removal of preform material
    • 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]
    • C03B37/01466—Means for changing or stabilising the diameter or form of tubes or rods
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating

Definitions

  • the present invention relates to a method of manufacturing an optical fiber preform comprising a core part and a clad part), and more particularly to a method of manufacturing an optical fiber obtained by spinning an optical fiber preform.
  • the present invention relates to a technology for improving the yield.
  • a soot deposit composed of fine silica glass particles is produced by the VAD method or the CVD method, and this is sintered and made transparent to produce a glass rod.
  • Some of these glass rods consist only of a core part, and others have a part of the cladding part formed around the core part.
  • the glass rod is inserted into a quartz glass tube serving as a cladding portion, and a rod-in-tube method for heating and unifying, or a soot serving as a cladding portion is deposited on the outer periphery of the glass rod.
  • An optical fiber preform is formed by forming a clad around the glass rod by a method such as an external method for converting the glass into a transparent glass.
  • the optical fiber preform is drawn and spun to produce an optical fiber.
  • optical fiber preforms when forming the cladding on the glass head, for example, if the goal is to form the cladding with the goal of keeping the outer diameter ratio of the core and Z cladding constant, It is difficult to form the clad part in the same way, and the outer diameter of the clad part may fluctuate along the longitudinal direction of the optical fiber preform.
  • the outer diameter of the cladding changes, the outer diameter ratio of the core part of the optical fiber preform changes along the longitudinal direction of the optical fiber preform.
  • the characteristics of the optical fiber obtained by spinning the optical fiber preform fluctuate in the longitudinal direction.
  • the characteristic variation along the longitudinal direction of the optical fiber did not hinder practical use with a normal single-mode optical fiber with a large allowable range of the characteristic variation.
  • an optical fiber such as a dispersion-shifted optical fiber, which has a narrow permissible range of characteristic fluctuation along the longitudinal direction
  • the optical fiber if the characteristic fluctuation in the longitudinal direction of the optical fiber is large, the optical fiber has a small characteristic fluctuation.
  • the part may have poor characteristics and the yield may decrease.
  • the purpose of the present invention is to provide a method for manufacturing an optical fiber preform comprising a core and a clad, which is a semi-finished product of the optical fiber preform.
  • the thickness of the clad part of the target optical fiber preform is calculated from the measured value, and the remaining clad part to be further formed on the glass rod is calculated based on the calculated value. This is accomplished by polishing a portion of this remaining cladding, or depositing additional cladding over the remaining cladding, after it has been formed generally on the cladding.
  • the purpose is to form the above-mentioned remaining clad part on the glass rod, measure the refractive index distribution of the glass rod, and obtain the clad part of the target optical fiber preform from the measured value. Calculate the total thickness of the remaining cladding and, based on this calculated value, achieve the required power by polishing the remaining cladding or by depositing additional cladding on the remaining cladding. Is done.
  • the measurement of the refractive index distribution of the glass rod is preferably performed at a plurality of positions along the longitudinal direction of the glass rod.
  • the above-described force for polishing the remaining clad portion or the step of depositing an additional clad portion on the remaining clad portion is performed twice or more, so that the clad portion of the obtained optical fiber preform is obtained.
  • the overall thickness is very close to the calculated value As a result, it is possible to further suppress the characteristic fluctuation along the longitudinal direction of the optical fiber.
  • the thickness of the lad portion to be polished or deposited after the formation of the remaining clad portion is within a range of 10% or less of the thickness of the remaining clad portion. If it exceeds 10%, it takes too much time for polishing or deposition, and productivity is reduced.
  • a semi-finished product of an optical fiber preform the refractive index distribution along the longitudinal direction of a glass rod having a core part and a part of a clad part is measured, and from this measured value, a target optical fiber preform is obtained.
  • calculate the thickness of the remaining clad part that satisfies the entire thickness of this clad part calculate the thickness of the remaining clad part by the glass rod.
  • the polishing amount of the optical fiber preform can be adjusted by controlling one or both of the moving speed of the bar and the flow rate of the gas supplied to the parner.
  • FIG. 1A is a diagram illustrating a first example of the first embodiment of the present invention.
  • FIG. 1B is a diagram illustrating a first example of the first embodiment of the present invention.
  • FIG. 1C is a diagram illustrating a first example of the first embodiment of the present invention.
  • FIG. 2A is a diagram illustrating a second example of the first embodiment of the present invention.
  • FIG. 2B is a diagram illustrating a second example of the first embodiment of the present invention.
  • FIG. 2C is a diagram illustrating a second example of the first embodiment of the present invention.
  • FIG. 3A is a diagram illustrating a third example of the first embodiment of the present invention.
  • FIG. 3B is a diagram illustrating a third example of the first embodiment of the present invention.
  • FIG. 3C is a diagram illustrating a third example of the first embodiment of the present invention.
  • FIG. 3D is a diagram illustrating a third example of the first embodiment of this invention.
  • FIG. 4A is a diagram illustrating an example of the second embodiment of the present invention.
  • FIG. 4B is a diagram illustrating an example of the second embodiment of the present invention.
  • FIG. 4C is a diagram illustrating an example of the second embodiment of the present invention.
  • FIG. 5A is a diagram illustrating an example of the third embodiment of the present invention.
  • FIG. 5B is a diagram illustrating an example of the third embodiment of the present invention.
  • FIG. 5C is a diagram illustrating an example of the third embodiment of the present invention.
  • FIG. 5D is a diagram illustrating an example of the third embodiment of the present invention.
  • FIG. 6 is a diagram illustrating an example of a change in the longitudinal direction of the target value of the thickness of the clad portion in the embodiment of the present invention as a deviation from the average value of the target value of the overall thickness of the clad portion. .
  • FIG. 7 is a diagram illustrating an example of the outer diameter of the optical fiber preform according to the embodiment of the present invention.
  • FIG. 8 is a diagram illustrating an example of a variation in dispersion along the longitudinal direction of an optical fiber obtained by spinning the optical fiber preform according to the embodiment of the present invention.
  • FIG. 9 is a diagram showing an example of a variation in dispersion along the longitudinal direction of an optical fiber obtained by spinning a glass rod of a comparative example in which the remaining clad portion is formed.
  • FIG. 10 is a diagram showing an example of an optical fiber preform processing apparatus according to the present invention.
  • FIG. 11 is a view showing another example of the optical fiber preform processing apparatus according to the present invention.
  • FIG. 12 is a chart showing an example of actually measured values of the relationship between the gas flow rate of the burner and the polishing amount per hour.
  • FIG. 13 is a diagram illustrating an example of a change in a target diameter and an outer diameter before and after flame polishing of the optical fiber preform according to the embodiment of the present invention.
  • FIG. 14 is a chart showing an example of a deviation of the outer diameter of the optical fiber preform after flame polishing from the target diameter in the example of the present invention.
  • FIG. 15 is a diagram showing an example of a variation width of dispersion along a longitudinal direction in an optical fiber obtained by spinning the optical fiber preform of the example of the present invention.
  • the method for manufacturing an optical fiber preform of the present invention is suitable for an optical fiber preform which is a semi-finished product of an optical fiber having a narrow permissible width of characteristic change along its longitudinal direction.
  • optical fiber examples include a dispersion-shifted optical fiber and a dispersion-compensating optical fiber.
  • a semi-finished product of an optical fiber preform the refractive index distribution of a glass port having a core part and a part of a clad part is measured, and a target After calculating the total thickness of the clad portion of the optical fiber preform to be formed, the remaining clad portion to be further formed on the glass rod is formed on the glass rod based on the calculated value. Polish the remaining cladding or deposit additional cladding on the remaining cladding.
  • the refractive index distribution of a glass rod can be measured by an optical method using a preform analyzer or
  • a parallel beam or a thin laser beam is irradiated from the side of the glass rod and refracted.
  • a method of measuring the refractive index distribution from the angle of incidence of the transmitted light on the measuring instrument, or Characteristics of germanium emitted by X-ray irradiation to the glass mouth One method is to measure the doping amount of germanium from the intensity of X-rays and then determine the refractive index distribution.
  • the measurement of the refractive index distribution of the glass rod may be performed at one position or at multiple positions on the glass rod, but in order to know in detail the fluctuation of the refractive index distribution of the glass rod along the longitudinal direction.
  • the entire thickness of the target optical fiber preform cladding is calculated.
  • the overall thickness of the cladding may be simply determined so that the outer diameter ratio of the core / cladding in the target optical fiber preform is constant along the longitudinal direction.
  • the Maxwell equation is applied to the target optical fiber preform, and analysis is performed to minimize the longitudinal fluctuations in the characteristics such as dispersion and power cutoff wavelength of the optical fiber obtained from the optical fiber preform. You may decide by doing.
  • the remaining clad is formed on the glass rod.
  • any means conventionally used for polishing glass mainly composed of quartz can be applied.
  • a grinder with a diamond grindstone is used for mechanical polishing
  • etching using hydrofluoric acid is used for chemical polishing
  • a plasma flame such as oxyhydrogen flame or oxygen or argon is used for flame polishing
  • chemical flame polishing is used.
  • a flame mixed with a fluorine-based gas such as sulfur hexafluoride can be used.
  • polishing methods may be applied alone. When the polishing is performed a plurality of times, the same method may be used each time, or a different method may be used for each.
  • Known methods such as a CVD method, an external method, and a rod-in-tube method can be applied as a method for depositing the additional clad portion.
  • a thin layer of cladding glass may be deposited by a CVD method, or a glass tube having a thickness of about 1 to 2 mm may be covered by a rod-in-tube method.
  • the polishing power of the cladding or the step of depositing an additional cladding on the cladding may be performed once, or the target optical fiber preform may be used. You may do it more than once until you get
  • the clad part refers to the combination of the remaining clad part and the additional clad part, and refers to ⁇ a part of the clad part '' originally included in the glass rod. Not something. In this case, the previously calculated value can be continuously used for the entire thickness of the clad portion of the target optical fiber preform.
  • the refractive index distribution of the glass rod is measured again, and from this measured value, the total thickness of the target optical fiber preform cladding portion is calculated again, whereby The accuracy of the entire thickness of the clad portion described above can be further improved.
  • the thickness of the clad portion to be polished or deposited after forming the remaining clad portion is preferably 10% or less of the thickness of the remaining clad portion. If the content exceeds 10%, the time required for polishing or depositing the clad portion increases, and the productivity is lowered.
  • the remaining cladding is polished, or additional cladding is deposited on the remaining cladding. It is preferable to do one only once. Therefore, when forming the remaining cladding, the thickness is larger or smaller than the calculated cladding thickness of the target optical fiber preform throughout the length of the glass rod. In the case where the remaining clad portion is formed and then the remaining clad portion is formed more than the calculated value, only the polishing of the remaining clad portion is performed, and the remaining clad portion is formed less than the calculated value. If so, only deposit additional cladding on the remaining cladding.
  • FIGS. 1A to 1C are diagrams illustrating a first example of the first embodiment of the present invention.
  • the total thickness in the longitudinal direction of the glass rod is larger than the calculated total thickness of the cladding of the target optical fiber preform, and the remaining A target optical fiber preform is obtained by forming a clad portion and then polishing only the remaining clad portion.
  • reference numeral 1 is a glass rod.
  • the refractive index distribution of the glass rod 1 is measured, and from this measured value, the overall thickness of the target optical fiber preform cladding is calculated to obtain the target optical fiber preform shape 10 .
  • the calculated value of the total thickness of the clad portion of the target optical fiber preform is larger than that of the remaining clad portion.
  • the remaining cladding 2 For example, the thickness of the remaining clad portion 2 for satisfying the target overall thickness of the clad portion of the optical fiber preform 3 is calculated, and the clad portion having the largest thickness of the calculated value is calculated. 2 may be formed over the entire area along the longitudinal direction of the glass opening 1.
  • the remaining optical fiber 2 is polished to obtain an optical fiber preform 3 as a target.
  • 2A to 2C are diagrams illustrating a second example of the first embodiment of the present invention.
  • the calculated value of the total thickness of the cladding of the target optical fiber preform is smaller than the calculated value of the total thickness of the remaining cladding throughout the longitudinal direction of the glass rod. Is formed, and then only the additional clad portion is deposited on the remaining clad portion to obtain a target optical fiber preform.
  • reference numeral 1 is a glass rod.
  • the refractive index distribution of the glass rod 1 is measured, and from this measured value, the entire thickness of the target optical fiber preform 3 clad part is calculated, and the target optical fiber preform shape 10 is calculated. obtain.
  • the calculated value of the total thickness of the clad portion of the target optical fiber preform 3 is smaller than that of the remaining clad portion 2.
  • the thickness of the remaining cladding part 2 to satisfy the target thickness of the entire cladding part of the optical fiber preform 3 is calculated.
  • the clad portion 2 having the smallest thickness of the calculated value may be formed over the entire area along the longitudinal direction of the glass rod 1.
  • a target optical fiber preform 3 is obtained by depositing an additional cladding part 4 on the remaining cladding part 2.
  • the quartz glass tube as the remaining clad is polished or ground based on the calculated value of the total thickness of the clad of the target optical fiber preform. Or, deposit additional cladding over it
  • the glass rod is inserted into the quartz glass tube, and then heated and integrated to obtain a target optical fiber preform.
  • the thickness of the quartz glass tube can be changed to a thickness that matches the outer diameter of the glass port, so that the yield is improved. Also, the polishing of the glass tube or the deposition of additional cladding thereon prevents damage to the glass rod, thereby preventing degradation of the properties of the optical fiber preform.
  • the polishing of the quartz glass tube and the deposition of the additional clad portion thereon are performed by polishing the glass head on which the remaining clad portion is formed and the polishing thereof. This is done in a manner similar to the deposition of additional cladding on the pit.
  • the quartz glass tube is stretched by fixing one end of the quartz glass tube and stretching the other end by heating the middle part with a heating furnace while pulling the other end, or the speed of feeding into the heating furnace and the heating furnace. This is done by making a difference between the speed and the thickness of the quartz glass tube.
  • a heating furnace a carbon resistance furnace, an induction heating furnace, an oxyhydrogen flame furnace, a plasma flame furnace, and the like can be used.
  • FIGS. 3A to 3D are diagrams illustrating a third example of the first embodiment of the present invention.
  • reference numeral 1 is a glass rod.
  • the refractive index distribution of the glass rod 1 is measured, and from this measured value, the entire thickness of the target optical fiber preform 3 clad part is calculated, and the target optical fiber preform shape 10 is determined. obtain.
  • the quartz glass tube 6 is polished according to the target optical fiber preform shape 10.
  • the glass rod 1 is inserted into the quartz glass tube 6 and heat and heat are integrated to obtain the target optical fiber preform 3.
  • a second embodiment of the present invention will be described.
  • the refractive index distribution of the glass rod is measured, and from this measured value, the entire thickness of the clad portion of the target optical fiber preform is calculated. Based on the calculated value, the remaining clad portion is calculated. Polishing force or deposit additional cladding on remaining cladding.
  • the conventional optical system is used until the formation of the remaining cladding.
  • a method for manufacturing a fiber preform can be implemented. As a result, there is an advantage that changes in the production line are reduced.
  • the polishing power of the clad portion or the step of depositing an additional clad portion on the clad portion may be performed once, and the target optical fiber preform is obtained. You may do it more than once until you get it.
  • the cladding here refers to the rest of the cladding and the additional cladding together, not to the ⁇ part of the cladding '' originally included in the glass rod. . In this case, the previously calculated value can be continuously used for the entire thickness of the clad portion of the target optical fiber preform.
  • the refractive index distribution of the glass rod is measured again, and from this measured value, the entire thickness of the clad portion of the target optical fiber preform is calculated again, whereby the overall thickness of the clad portion is calculated. Accuracy can be further increased.
  • the thickness of the cladding to be polished or deposited is preferably less than 10% of the thickness of the remaining cladding on the glass lip. If it exceeds 10%, the time required for polishing or depositing the clad increases, and the productivity decreases. It is not preferable.
  • the number of steps of polishing the remaining cladding or depositing an additional cladding on the remaining cladding is preferably smaller.
  • FIGS. 4A to 4C are diagrams illustrating an example of the second embodiment of the present invention.
  • reference numeral 1 denotes a glass rod, on which the remaining cladding 2 is formed.
  • the refractive index distribution of the glass rod 1 is measured, and the target thickness of the entire cladding of the optical fiber preform 3 is calculated from the measured value.
  • Reference numeral 10 indicates a target shape of the optical fiber preform 3 obtained from the calculated value of the entire thickness of the clad portion.
  • the thickness of the additional clad portion 4 is calculated from the calculated value of the entire thickness of the clad portion of the target optical fiber preform 3, and the maximum value is obtained.
  • the additional cladding part 4 is formed over the entire area along the longitudinal direction of the glass opening 1 by the maximum thickness of the additional cladding part 4.
  • an additional optical fiber part 4 is polished to obtain an optical fiber preform 3 as a target.
  • the refractive index distribution in the longitudinal direction of a glass port having a core part and a part of a clad part, which is a semi-finished product of an optical fiber preform is measured. From the values, calculate the overall thickness of the cladding of the target optical fiber preform, and calculate the thickness of the remaining cladding to satisfy the overall thickness of this cladding.
  • the glass rod is polished so that the thickness of the clad part is constant in the longitudinal direction of the glass opening, and the remaining clad part having a constant thickness is deposited.
  • FIG. 5A to 5D are diagrams illustrating an example of the third embodiment of the present invention.
  • the target optical fiber pre- When there is a large change in the outer diameter of the glass rod 1, for example, the target optical fiber pre-
  • the target optical fiber preform shape 10b has a larger variation in outer diameter as shown in Fig.5B. .
  • the deviation between the outer diameter when the remaining clad portion 2 is formed and the target outer diameter of the optical fiber preform 3 becomes large, so that the thickness of the clad portion to be polished or deposited becomes large. And lead to lower productivity.
  • the thickness of the remaining clad 2 is constant in the longitudinal direction of the glass port 1, the outer diameter when the remaining clad 2 is formed, and The deviation from the outer diameter of the target optical fiber preform 3 can be reduced.
  • the thickness of the clad portion to be polished or deposited after the formation of the remaining clad portion 2 can be reduced, and the productivity is improved.
  • the target optical fiber preform shape 10 and the target glass rod shape 11 are determined.
  • the glass rod is polished.
  • the remaining clad portion 2 is formed thereon, and the target optical fiber preform 3 is obtained.
  • the present invention is applied to the production of an optical fiber preform for a dispersion-shifted optical fiber.
  • FIG. 6 is a diagram illustrating an example of a variation in the target value of the thickness of the clad portion along the longitudinal direction as a deviation from the average value of the target value of the entire thickness of the clad portion.
  • the remaining clad portion was formed on the glass rod by an external method.
  • FIG. 7 is a diagram illustrating an example of the outer diameter of the optical fiber preform in this embodiment.
  • the “outside diameter after external attachment” is the outside diameter after the remaining clad part is formed on the glass rod, and the “target outside diameter” is The calculated outer diameter of the target optical fiber preform.
  • the remaining clad portion was formed such that the outer diameter after external attachment became larger than the target outer diameter over the entire area in the longitudinal direction.
  • the remaining clad portion was polished by flame polishing using an oxyhydrogen flame to obtain a target optical fiber preform.
  • FIG. 8 shows an example of variation in dispersion along the longitudinal direction of an optical fiber obtained by drawing this optical fiber preform.
  • an optical fiber with extremely small dispersion fluctuation can be obtained.
  • FIG. 9 is a diagram illustrating, as a comparative example, an example of a variation in dispersion along the longitudinal direction of an optical fiber obtained by spinning a glass opening on which a remaining clad portion is formed.
  • the obtained optical fiber had a large variation in dispersion as shown in Fig. 9, and there was a region outside the range conforming to the standard.
  • the optical fiber preform when polishing the optical fiber preform to a desired outer diameter, especially when the ratio of the core diameter and the cladding diameter of the optical fiber preform is corrected by flame polishing using a wrench, the optical fiber preform is spun.
  • the characteristics of the optical fiber obtained in this manner such as the cut-off wavelength and the zero dispersion slope, have small fluctuations in the longitudinal direction.
  • flame polishing is used to correct the outer diameter of the optical fiber preform, it can be polished while removing scratches and residual strain on the surface of the optical fiber preform. Damage and deterioration can be prevented.
  • polishing must be performed using the same equipment as that used in conventional flame polishing. This is advantageous in terms of equipment loss.
  • This control is performed automatically, for example, by sending a control signal from the controller to the motor that is the drive means of the wrench or the valve that adjusts the gas flow rate, and controlling the rotation speed of the motor or the opening amount of the valve.
  • the flow rate of the controlled gas may be one or both of the flow rate of a fuel gas such as hydrogen and the flow rate of a supporting gas such as oxygen. Further, only one of the moving speed of the wrench and the gas flow rate may be changed with time, and the other may be kept constant.
  • the method of controlling the moving speed of the parner and the gas flow rate is performed, for example, as follows. That is, since the desired polishing amount varies depending on the position in the longitudinal direction on the optical fiber preform, the moving speed of the parner is changed in accordance with the variation in the polishing amount, and the desired polishing amount is changed to a position where the desired polishing amount is large. Irradiates the flame of Pana for a relatively long time and for a relatively short time in a few places. Further, the gas flow rate is changed in accordance with the variation in the polishing amount. The gas flow rate is increased when the total polishing amount is large, and decreased when the total polishing amount is small.
  • the relationship between the gas flow rate and the polishing amount of the optical fiber preform depends on the shape, structure, number, arrangement, etc. of the used parners, so that it is preferable to measure for each device used. .
  • this measurement only needs to be performed at least once when the burner is changed.
  • the polishing amount of the optical fiber preform is measured, for example, as the weight that is polished in a certain period of time, it can be used as an amount that does not depend on the outer diameter of the optical fiber preform. Can be.
  • the profile of the optical fiber preform was measured over the entire area in the longitudinal direction using a preform analyzer, and the obtained data was analyzed by computer processing to minimize fluctuations in the characteristics of the optical fiber in the longitudinal direction.
  • Outer diameter of the optical fiber preform as a function of longitudinal position on the optical fiber preform.
  • a program for controlling the moving speed of the wrench is created by a computer on the basis of the outer diameter and the target diameter before flame polishing, and this program is executed on the controller to move the wrench to perform the flame polishing.
  • this program is executed on the controller to move the wrench to perform the flame polishing.
  • This method of processing an optical fiber preform can be performed without performing feedback control as described above, but may be performed in combination with feedback control. Thereby, the processing accuracy can be further improved.
  • the outer diameter of the optical fiber preform is measured in real time using an outer diameter measuring device, displacement meter, line sensor, etc., and this data is feed knocked to control the above polishing amount.
  • the polishing is performed in a plurality of times, and the outer diameter of the optical fiber preform is measured each time one polishing is completed, and this data is used as the polishing amount in the next polishing. May be fed back to the control.
  • the optical fiber preform can be polished into an arbitrary shape such as a cylindrical shape, a tapered shape, and an inverted taper shape.
  • FIG. 10 shows a processing apparatus 20 for performing the above method.
  • the processing apparatus 20 includes a lathe 22 for rotating the optical fiber preform 21, a pair of chucks 23 mounted on the lathe 22 and holding the optical fiber preform 21, and an optical fiber preform 2. It is roughly composed of a panner 25 heating 1.
  • the parner 25 reciprocates on guide rails 27 provided along the longitudinal direction of the optical fiber preform 21 under the control of the parner moving speed controller 26.
  • Ma The gas is supplied from the gas supply unit 29 to the parner 25, and the flow rate of the gas is controlled by the gas flow control unit 28.
  • the parner moving speed control section 26 and the gas flow rate control section 28 are connected to a controller 31 for sending control signals to them, and the controller 31 is connected to a computer 32 to execute a program from the computer 32. You can receive it.
  • the controller 31 controls the moving speed of the parner.
  • the control by the controller 31 is performed according to a program created based on the actual measured value of the outer diameter of the optical fiber preform 21 measured before polishing and the target diameter predicted by the computer 32.
  • the optical fiber preform 21 is removed from the processing device 20 and sent to the next step.
  • FIG. 11 is a view showing another example of the processing apparatus 20.
  • members denoted by the same reference numerals as those used in FIG. 10 have the same configuration as in FIG.
  • An outer diameter measuring device 33 that is moved by a moving means (not shown) in synchronization with the parner 5 is attached to the processing device 20.
  • the outer diameter measuring device 33 measures the outer diameter of the optical fiber preform 21 and feeds back this data to the computer 32.
  • the outer diameter of the optical fiber preform 21 is measured in real time by the outer diameter measuring device 33, and based on the data of the outer diameter, the computer 32 appropriately executes a program. Then, the controller 31 adjusts the control of the parner moving speed controller 26 or the gas flow controller 28 in accordance with the changed program. Therefore, the optical fiber preform 2 1 force S, processed with even higher precision It is.
  • FIG. 12 is a diagram showing an example of measured values of the relationship between the flow rate of hydrogen and the polishing amount per hour when the flow rate of oxygen is set to 160 liters in flame polishing.
  • Figure 13 shows the results of flame polishing of an optical fiber preform for a dispersion-shifted optical fiber, using the relationship shown in Fig. 12 and changing the moving speed of the wrench to a constant gas flow rate. .
  • the outer diameter of the optical fiber preform before and after flame polishing was measured by an outer diameter measuring instrument, and the target diameter was the one with the smallest variation in dispersion along the longitudinal direction of the optical fiber. Is the outer diameter predicted by the computer to be
  • the gas flow rate per burner was 200 liters of hydrogen and 80 liters of oxygen. As a whole, the flow rate of hydrogen was 400 liters and the flow rate of oxygen was 160 liters. The gas flow rates were constant over time.
  • a program for controlling the moving speed of the burner was generated by a computer, and the burner was moved according to this program to perform flame polishing.
  • Fig. 14 shows the deviation of the outer diameter of this optical fiber preform after flame polishing from the target diameter. As shown in FIG. 14, the deviation from the target diameter was 0.1 mm on average and 0.2 mm at maximum.
  • an optical fiber preform whose outer diameter was corrected by flame polishing was spun to produce a dispersion-shifted optical fiber.
  • Fig. 15 shows the fluctuation range of dispersion along the longitudinal direction in this dispersion-shifted optical fiber.
  • the fluctuation range of the dispersion in Fig. 15 is as follows: D is the dispersion of the dispersion-shifted optical fiber, and Dm is the median of the permissible specifications of this type of dispersion-shifted optical fiber. 100 X (D-Dm) / D m (%).
  • the optical fiber obtained by spinning an optical fiber preform polished by flame polishing has a dispersion fluctuation range within 0.5% of soil over the entire area in the longitudinal direction. Was.

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Abstract

L'invention concerne une préforme de fibre optique permettant d'obtenir des fibres optiques dont l'irrégularité caractéristique est supprimée dans le sens longitudinal, ainsi qu'un procédé de fabrication de cette préforme de fibre optique. Ladite préforme de fibre optique comprend une partie coeur et une partie gaine. Le procédé consiste à mesurer la distribution de l'indice de réfraction d'une tige de verre constituant le produit semi-fini de la préforme de fibre optique et comportant une partie de la partie coeur et de la partie gaine, à calculer, à partir des valeurs mesurées, l'épaisseur de la partie gaine totale de la préforme de fibre optique visée, à former, sur la base des valeurs calculées, la partie gaine restante sur la tige de verre, puis à polir une partie de la partie gaine restante ou à superposer une partie gaine supplémentaire sur la partie gaine restante.
PCT/JP2002/006804 2001-07-06 2002-07-04 Procede de fabrication d'une preforme de fibre optique WO2003004426A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2001206279A JP2003020239A (ja) 2001-07-06 2001-07-06 光ファイバプリフォームの加工方法
JP2001-206279 2001-07-06
JP2001224808A JP2003040636A (ja) 2001-07-25 2001-07-25 光ファイバ母材の製造方法
JP2001-224808 2001-07-25

Publications (1)

Publication Number Publication Date
WO2003004426A1 true WO2003004426A1 (fr) 2003-01-16

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Application Number Title Priority Date Filing Date
PCT/JP2002/006804 WO2003004426A1 (fr) 2001-07-06 2002-07-04 Procede de fabrication d'une preforme de fibre optique

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Country Link
WO (1) WO2003004426A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1505039A3 (fr) * 2003-08-08 2005-05-04 Sumitomo Electric Industries, Ltd. Préforme de fibre optique, fibre optique et leurs méthodes de fabrication
WO2008059520A2 (fr) * 2006-10-12 2008-05-22 Sterlite Optical Technologies Limited Procédé de préparation d'un ensemble de broche pour gainage, et préforme et fibre produites à partir d'un tel ensemble de broche

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60141634A (ja) * 1983-12-28 1985-07-26 Shin Etsu Chem Co Ltd 光フアイバ−用母材およびその製造方法
JPS62226831A (ja) * 1986-03-27 1987-10-05 Mitsubishi Cable Ind Ltd 光フアイバ母材の自動外径調整方法
JPH04292434A (ja) * 1991-03-18 1992-10-16 Fujikura Ltd 光ファイバ母材の製造方法
JPH0672734A (ja) * 1992-08-25 1994-03-15 Furukawa Electric Co Ltd:The 光ファイバ母材の多孔質ガラス層形成工程におけるスート剥離方法
JPH0672735A (ja) * 1992-08-25 1994-03-15 Furukawa Electric Co Ltd:The 光ファイバ母材の製造方法
JPH0692667A (ja) * 1992-09-08 1994-04-05 Furukawa Electric Co Ltd:The 光ファイバ母材の製造方法
JPH08310823A (ja) * 1995-05-15 1996-11-26 Sumitomo Electric Ind Ltd ガラス母材の火炎研磨方法
US5674305A (en) * 1993-02-22 1997-10-07 Sumitomo Electric Industries, Ltd. Method for flame abrasion of glass preform
JPH1135335A (ja) * 1997-07-17 1999-02-09 Sumitomo Electric Ind Ltd 光ファイバ母材の製造方法

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60141634A (ja) * 1983-12-28 1985-07-26 Shin Etsu Chem Co Ltd 光フアイバ−用母材およびその製造方法
JPS62226831A (ja) * 1986-03-27 1987-10-05 Mitsubishi Cable Ind Ltd 光フアイバ母材の自動外径調整方法
JPH04292434A (ja) * 1991-03-18 1992-10-16 Fujikura Ltd 光ファイバ母材の製造方法
JPH0672734A (ja) * 1992-08-25 1994-03-15 Furukawa Electric Co Ltd:The 光ファイバ母材の多孔質ガラス層形成工程におけるスート剥離方法
JPH0672735A (ja) * 1992-08-25 1994-03-15 Furukawa Electric Co Ltd:The 光ファイバ母材の製造方法
JPH0692667A (ja) * 1992-09-08 1994-04-05 Furukawa Electric Co Ltd:The 光ファイバ母材の製造方法
US5674305A (en) * 1993-02-22 1997-10-07 Sumitomo Electric Industries, Ltd. Method for flame abrasion of glass preform
JPH08310823A (ja) * 1995-05-15 1996-11-26 Sumitomo Electric Ind Ltd ガラス母材の火炎研磨方法
JPH1135335A (ja) * 1997-07-17 1999-02-09 Sumitomo Electric Ind Ltd 光ファイバ母材の製造方法

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1505039A3 (fr) * 2003-08-08 2005-05-04 Sumitomo Electric Industries, Ltd. Préforme de fibre optique, fibre optique et leurs méthodes de fabrication
WO2008059520A2 (fr) * 2006-10-12 2008-05-22 Sterlite Optical Technologies Limited Procédé de préparation d'un ensemble de broche pour gainage, et préforme et fibre produites à partir d'un tel ensemble de broche
WO2008059520A3 (fr) * 2006-10-12 2009-09-24 Sterlite Optical Technologies Limited Procédé de préparation d'un ensemble de broche pour gainage, et préforme et fibre produites à partir d'un tel ensemble de broche

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