GB2325928A - Apparatus for manufacturing erbium-doped optical fibre preform - Google Patents
Apparatus for manufacturing erbium-doped optical fibre preform Download PDFInfo
- Publication number
- GB2325928A GB2325928A GB9819690A GB9819690A GB2325928A GB 2325928 A GB2325928 A GB 2325928A GB 9819690 A GB9819690 A GB 9819690A GB 9819690 A GB9819690 A GB 9819690A GB 2325928 A GB2325928 A GB 2325928A
- Authority
- GB
- United Kingdom
- Prior art keywords
- quartz tube
- erbium
- solution
- tube
- optical fibre
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
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]
- C03B37/018—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
- C03B37/01884—Means for supporting, rotating and translating tubes or rods being formed, e.g. lathes
-
- 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
- C03B37/01838—Reactant delivery systems, e.g. reactant deposition burners for delivering and depositing additional reactants as liquids or solutions, e.g. for solution doping of the deposited glass
-
- 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
- C03B2201/31—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with germanium
-
- 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
- C03B2201/34—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with rare earth metals, i.e. with Sc, Y or lanthanides, e.g. for laser-amplifiers
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Lasers (AREA)
Abstract
Apparatus for making an erbium-doped optical fibre preform comprises a clamping chuck 24 for clamping a quartz tube 10 and means for introducing heated gas 20 (eg O 2 ) into the quartz tube. The chuck can rotate the quartz tube which may be connected to the chuck via a connecting tube 22. The heat source 26 may be an oxygen/hydrogen burner. The heated gas is passed through the quartz tube to dry the solution containing erbium which has been absorbed by the quartz.
Description
METHOD OF AND APPARATUS FOR MANUFACTURING
ERBIUM-DOPED OPTICAL FIBRES
Background of the Invention
The present invention relates to a method of and an apparatus for manufacturing optical fibres, and more particularly to a method of and an apparatus for erbiumdoped optical fibres usable as optical amplifiers.
Where long-distance signal transmission is performed in an ultrahigh-speed information communications network or in a long-distance communications network or where an optical signal generated in one area branches off in various directions, the optical signal is inevitably attenuated.
In this case, it is necessary to amplify the optical signal. To do so, semiconductor amplifiers or optical amplifiers may be employed. In particular, semiconductor amplifiers have widely been used as an essential element of ultrahigh-speed information communications networks because they can directly amplify optical signals to a desired high level without requiring complicated signal processing.
Such optical amplifiers employ optical fibres such as those containing erbium (Er) which is a medium serving to amplify internally an optical signal. Such erbium-doped optical fibres may be manufactured using various methods.
The most frequently used and reliable method is modified chemical vapour deposition (MCVD) . The following description applies to the case wherein erbium-doped optical fibres are manufactured using MCVD.
A conventional method for manufacturing a substrate of erbium-doped optical fibres using MCVD will now be described in conjunction with FIGS. 1 and 2. A connecting tube 22 is first clamped at one end on a clamping chuck 24, as shown in FIG. 2. A quartz tube 10, which is called "a supporting tube", is connected at the other end of the connecting tube 22. The quartz tube 10 is used to manufacture an erbium-doped optical fibre substrate.
Thereafter, raw material 38 such as SiCl4 or GeCi4 transported from a raw supply system by a flow of oxygen is supplied to the interior of the quartz tube 10.
Subsequently, the quartz tube 10 is heated by an external heating source 26 (for example, an oxygen/hydrogen burner) while rotating. During the heating process, an oxidation reaction occurs in the interior of the quartz tube 10.
The oxidation reaction is expressed by the following formula:
In accordance with the oxidation reaction, particles of quartz-based oxides containing impurities are produced.
The oxide particles exist in the form of a deposition 32 on the inner surface of the quartz tube 10.
As the heating process is further carried out while the heating source 26 reciprocates in a longitudinal direction on the quartz tube 10, the particulate deposition 32 is sintered on the inner surface of the quartz tube 10 while being transparentized. As a result, a thin glass layer is formed on the inner surface of the quartz tube 10.
Thereafter, the above procedure is repeated until the glass layer on the inner surface of the quartz tube 10 has a desired thickness.
During the formation of the glass layer, a portion of the glass layer corresponding to a clad layer 14 is first formed, and a portion of the glass layer corresponding to a core layer 16 is then formed.
To manufacture erbium-doped optical fibres capable of directly amplifying optical signals to a desired high level without requiring complicated signal processing by use of the quartz tube 10 formed with the clad layer 14 and core layer 16, the quartz tube 10 is separated from the clamping chuck 24 after being closed at one end.
Thereafter, a solution containing erbium and other additive elements is injected into the interior of the quartz tube 10 closed at one end. The quartz tube 10 is then maintained in the above-mentioned condition for a desired period of time so as to allow the erbium 18 to be absorbed in the core layer 16 to a desired extent. After a desired period of time elapses, the solution is removed from the quartz tube 10. At this time, the core layer 16 has absorbed the solution containing the erbium 18 and other additive elements.
Subsequently, the quartz tube 10 is clamped again on the clamping chuck 24, and its closed end is then opened. The clamping chuck 24 then rotates to rotate the quartz tube 10 so as to prevent the solution absorbed in the core layer 16 from being irregularly concentrated in the core layer 16, as shown in FIG. 2. Thereafter, the quartz tube 10 is maintained for a long period of time as it is, so that the solution absorbed in the quartz tube 10 can be air-dried.
After the erbium 18 absorbed in the quartz tube 10 is completely dried in the above process, the quartz tube 10 is heated again to a high temperature using the heating source 26, so that it is softened. Thereafter, both ends of the quartz tube 10 are completely sealed. Thus, an erbium-doped optical fibre substrate having a hollow cylindrical structure is obtained.
However, the above-mentioned method involving the drying of the solution containing the erbium 18 and other additive elements absorbed in the quartz tube 10 is problematic in that a long period of time is required to carry out the drying process because it is performed in a natural air-dried state. This results in long manufacturing times for erbium-doped optical fibre substrates. As a result, the manufacturing productivity of erbium-doped optical fibre substrates is affected.
Furthermore, the costs of erbium-doped optical fibre substrates are high. In addition, irregular drying may occur because the quartz tube 10 is dried in a natural air-dried state. Such irregular drying results in a nonuniform refractivity distribution.
Another conventional method for manufacturing a substrate of erbium-doped optical fibres using MCVD will now be described in conjunction with FIGS. 1 and 3. In FIG. 3, elements respectively corresponding to those in FIG. 2 are denoted by the same reference numerals. A connecting tube 22 is first clamped at one end on a clamping chuck 24, as shown in FIG. 3. A quartz tube 10, which is called "a supporting tube", is connected at the other end of the connecting tube 22. The quartz tube 10 is used to manufacture an erbium-doped optical fibre substrate.
Thereafter, raw material 38 such as SiC14 or GeCl4 transported from a raw supply system by a flow of oxygen is supplied to the interior of the quartz tube 10.
Subsequently, the quartz tube 10 is heated by an external heating source 26 (for example, an oxygen/hydrogen burner) while rotating. During the heating process, an oxidation reaction occurs in the interior of the quartz tube 10.
The oxidation reaction is expressed by the following formula:
In accordance with the oxidation reaction, particles oj quartz-based oxides containing impurities are produced.
The oxide particles exist in the form of a deposition 3 on the inner surface of the quartz tube 10.
As the heating process is further carried out while the heating source 26 reciprocates in a longitudinal directior on the quartz tube 10, the particle deposition 32 iE sintered on the inner surface of the quartz tube 10 while being transparentized. As a result, a thin glass layer iE formed on the inner surface of the quartz tube 10.
Thereafter, the above procedure is repeated until the glass layer on the inner surface of the quartz tube 10 has a desired thickness.
During the formation of the glass layer, a portion of the glass layer corresponding to a clad layer 14 is first formed, and a portion of the glass layer corresponding tc a core layer 16 is then formed.
To manufacture erbium-doped optical fibres capable ot directly amplifying optical signals to a desired high level without requiring complicated signal processing bb use of the quartz tube 10 formed with the clad layer 19 and core layer 16, the quartz tube 10 is separated fron the clamping chuck 24 after being closed at one end.
Thereafter, a solution containing erbium and othei additive elements is injected into the interior of the quartz tube 10 closed at one end.
The quartz tube 10 is then maintained in the abovementioned condition for a desired period of time so as tc allow the erbium 18 to be absorbed in the core layer 16 tc a desired amount. After a desired period of time elapses, the solution is removed from the quartz tube 10. At thine time, the core layer 16 has absorbed the solution containing the erbium 18 and other additive elements.
Subsequently, the quartz tube 10 is clamped again on the clamping chuck 24, and its closed end is then opened. The clamping chuck 24 then rotates to rotate the quartz tube 10 so as to prevent the solution absorbed in the core layer 16 from being sporadically concentrated in the core layer 16, as shown in FIG. 3. During the rotation of the quartz tube 10, the outer surface of the quartz tube 10 is slowly heated by a heater 30 at a low temperature while the heater 30 reciprocates in a longitudinal direction on the quartz tube 10, thereby causing the solution absorbed in the quartz tube 10 to be slowly dried.
After the erbium 18 absorbed in the quartz tube 10 is completely dried in accordance with the above process, the quartz tube 10 is heated again by a heating source 26 at a high temperature, so that it is softened. Thereafter, both ends of the quartz tube 10 are completely sealed.
Thus, an erbium-doped optical fibre substrate having a hollow cylindrical structure is obtained.
Where the solution containing the erbium 18 and other additive elements absorbed in the quartz tube 10 is dried in accordance with the above-mentioned method shown in
FIG. 3, it is possible greatly to reduce the drying time, as compared with the method of FIG. 2 using a natural airdrying process. This is because the outer surface of the quartz tube 10 is slowly heated by the heater 30 at a warm temperature while the heater 30 reciprocates in a longitudinal direction on the quartz tube 10, thereby causing the solution absorbed in the quartz tube 10 to be dried.
Even in this case, however, several hours are required to dry the quartz tube 10. As a result, this method is also problematic in that a long period of time is taken to manufacture erbium-doped optical fibre substrates. As a result, the manufacturing productivity of erbium-doped optical fibre substrates is affected. In addition, irregular drying may occur. Such irregular drying results in a non-uniform refractivity distribution. Also, since the heater 30 is used to dry the quartz tube 10, additional time and costs are required to install the heater 30. Moreover, erroneous installation of the heater 30 may cause errors in the manufacture of erbium-doped optical fibre substrates.
Therefore, an object of the invention is to provide a method of and an apparatus for manufacturing erbium-doped optical fibres, which method and apparatus are capable of uniformly drying a solution containing erbium and other additive elements absorbed in the core layer of a substrate.
Summary of the Invention
Accordingly, the present invention provides a method of manufacturing an erbium-doped optical fibre substrate comprising:
introducing into a quartz tube, having a clad layer deposited on its inner surface and a core layer deposited on the clad layer, a solution containing erbium;
allowing the core layer to absorb the solution and then removing the remaining solution from the quartz tube; and
introducing a flow of heated gas through the quartz tube to dry the solution which has been absorbed into the core layer of the quartz tube.
Preferably, the method comprises:
supplying raw material to the interior of the quartz tube;
rotating the quartz tube, while heating the quartz tube using an external heating source which reciprocates in a longitudinal direction on the quartz tube, to form a particle deposition on the inner surface of the quartz tube, sinter and transparentize the particle deposition to form a clad layer on the inner surface of the quartz tube;
supplying raw material to the interior of the quartz tube at a modified rate;
rotating the quartz tube, while heating the quartz tube using an external heating source which reciprocates in a longitudinal direction on the quartz tube, to form a particle deposition on the inner surface of the clad layer, sinter and transparentize the particle deposition to form a core layer on the inner surface of the clad layer.
Preferably, during deposition of the clad and core layers, the quartz tube is connected at one end to a connecting tube which is in turn clamped in a clamping chuck but separated from the clamping chuck before introduction of the said solution.
Preferably, during drying of the said solution absorbed into the core layer, the quartz tube is connected at one end to a connecting tube which is in turn clamped in a clamping chuck.
The gas may be heated by heating the connecting tube through which it passes before entering the quartz tube and rotating the clamping chuck. Preferably, the temperature to which the connecting tube is heated is equal to or less than the volatilization temperature of nitric acid.
Preferably, one end of the quartz tube is closed before the said solution is introduced. Similarly, it is preferred that the said one end of the quartz tube be opened again after the said solution is removed.
The said solution may contain other additive elements apart from erbium.
Preferably, the method further comprises heating the quartz tube after the solution has been dried to soften the quartz tube and sealing both ends of the quartz tube to provide an optical fibre substrate having a hollow cylindrical structure.
The raw material supplied to the interior of the quartz tube may comprise SiCl4, GeCl4 and 02. The gas introduced into the quartz tube may be oxygen.
The present invention also provides apparatus for manufacturing an erbium-doped optical fibre substrate comprising:
a clamping chuck for clamping a quartz tube; and
means for introducing a flow of heated gas through the quartz tube.
Preferably, the clamping chuck is adapted to rotate the quartz tube and the apparatus comprises:
a connecting tube adapted to connect the quartz tube to the clamping chuck;
a gas source for supplying gas to the interior of the quartz tube; and
a heat source for heating the gas introduced into the quartz tube.
The heat source may be an oxygen/hydrogen burner which is supplied with hydrogen.
Brief Description of the Drawings
The present invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 is a schematic view illustrating a process for manufacturing optical fibres in accordance with a wellknown MCVD method;
FIG. 2 is a schematic view illustrating a conventional method for drying erbium-doped optical fibres using a natural air-drying process;
FIG. 3 is a schematic view illustrating another conventional method for drying erbium-doped optical fibres using a heater; and
FIG. 4 is a schematic view illustrating a method for drying erbium-doped optical fibres using a heating source (an oxygen/hydrogen burner).
Detailed Description of the Preferred Embodiments
Referring to FIG. 4, an apparatus for manufacturing erbium-doped optical fibres in accordance with the present invention is illustrated. In FIG. 4, elements respectively corresponding to those in FIGS. 2 and 3 are denoted by the same reference numerals. In particular, the apparatus is used to dry a solution containing erbium and other additive elements absorbed in a quartz tube in the manufacture of an erbium optical fibre substrate using the MCVD method in accordance with the present invention.
As shown in FIGS. 1 and 4, the apparatus includes a chuck 24 which serves to fix a quartz tube 10 deposited with a clad layer 14 and a core layer 16 in accordance with the
MCVD method and to rotate the fixed quartz tube 10. A connecting tube 22 is fixedly mounted to one end of the chuck 24. The connecting tube 22 serves to connect the quartz tube 10 to the chuck 24. Beneath the connecting tube 22, a heating source 26 is disposed to generate heat for slowly drying the quartz tube 10 which absorbs a solution containing erbium 18 and other additive elements.
In the quartz tube 10, a desired amount of gas 20 is also introduced.
To increase the efficiency in drying the interior of the quartz tube 10, oxygen is used as the gas 20. For the heating source 26, an oxygen/hydrogen burner is used which is supplied with only hydrogen during ignition, while being supplied with no oxygen.
Now, a method for fabricating erbium-doped optical fibres using the above-mentioned apparatus in accordance with the present invention will be described in detail in conjunction with FIGS. 1 and 4. The quartz tube 10, which is used to manufacture an erbium-doped optical fibre substrate, is first connected to the connecting tube 22.
This connecting tube 22 is then clamped on the clamping chuck 24, as shown in FIG. 4. Thereafter, raw material 38 such as SiCl4 or GeCl4 transported from a raw supply system by a flow of oxygen is supplied to the interior of the quartz tube 10.
Subsequently, the quartz tube 10 is heated by the external heating source 26 (namely, the oxygen/hydrogen burner) while rotating it by the clamping chuck 24. During the heating process, an oxidation reaction occurs in the interior of the quartz tube 10. The oxidation reaction is expressed by the following formula:
In accordance with the oxidation reaction, particles of quartz-based oxides containing impurities are produced.
The oxide particles exist in the form of a deposition 32 on the inner surface of the quartz tube 10.
As the heating process is further carried out while the heating source 26 reciprocates in a longitudinal direction on the quartz tube 10, the particle deposition 32 is sintered on the inner surface of the quartz tube 10 while being transparentized. As a result, a thin glass layer is formed on the inner surface of the quartz tube 10.
Thereafter, the above procedure is repeated until the glass layer on the inner surface of the quartz tube 10 has a desired thickness.
During the formation of the glass layer, a portion of the glass layer corresponding to a clad layer 14 is first formed, and a portion of the glass layer corresponding to a core layer 16 is then formed. The formation of the core layer 16 is achieved by varying the amount of the raw material 38 from that used in the formation of the clad layer 14.
To manufacture erbium-doped optical fibres capable of directly amplifying optical signals to a desired high level without requiring a complicated signal processing by use of the quartz tube 10 formed with the clad layer 14 and core layer 16, the quartz tube 10 is first closed at its one end. The reason why the quartz tube 10 is closed at its one end is because when a solution containing erbium 18 and other additive elements is injected into the interior of the quartz tube 10, the solution and erbium 18 may leak from the interior of the quartz tube 10. The quartz tube 10 is then separated from the clamping chuck 24. Thereafter, a solution containing erbium and other additive elements is injected into the interior of the quartz tube 10 closed at one end.
The quartz tube 10 is then maintained in the abovementioned condition for a desired period of time so as to allow the erbium 18 to be absorbed in the core layer 16 to a desired amount. At this time, the core layer 16 has particles of an incomplete glass structure in order to allow the solution containing the erbium 18 and other additive elements to penetrate. After a desired period of time elapses, the solution is removed from the quartz tube 10. At this time, the core layer 16 has absorbed the solution containing the erbium 18 and other additive elements. Subsequently, the quartz tube 10 is clamped on the clamping chuck 24, and its closed end is then opened.
A large amount of gas 20 (i.e. gas at a high flow rate) is then fed into the interior of the quartz tube 10, as shown in FIG. 4. Oxygen is used as the gas 20 to increase the drying efficiency. Using the heating source 26, the connecting tube 22 is then uniformly heated at a temperature equal to or lower than the volatilization point of nitric acid. During the heating, the clamping chuck 24 rotates to rotate the quartz tube 10 so as to uniformly heat the connecting tube 22 (to uniformly heat the gas 20, namely, oxygen) while preventing the solution absorbed in the core layer 16 from being irregularly concentrated in the core layer 16. By this heating, the solution containing erbium 18 and other additive elements is slowly dried.
After the erbium 18 absorbed in the quartz tube 10 is completely dried in the above process, the quartz tube 10 is heated again at a high temperature using the heating source 26, so that it is softened. Thereafter, both ends of the quartz tube 10 are completely sealed. Thus, an erbium-doped optical fibre substrate having a hollow cylindrical structure is obtained.
In accordance with the above-mentioned method and apparatus of the present invention, it is possible to reduce greatly the time taken to manufacture erbium-doped optical fibres for optical amplifiers. In the manufacture of erbium-doped optical fibres using this method, the time taken to dry the solution is dependent on the condition of the core layer. Where it is assumed that the same core layers are formed using the same erbium-containing solutions, the conventional method of FIG. 2 using a heater can reduce the drying time to about 1/5 of the drying time taken in the natural air-drying method of FIG.
1. In accordance with the present invention, it is possible to reduce the drying time to about 1/2 of the drying time taken in the method of FIG. 2 using a heater.
Accordingly, the present invention reduces the time taken to manufacture an erbium-doped optical fibre substrate to about 1/4 of the time taken in the conventional methods.
This results in a greatly reduced manufacturing time of erbium-doped optical fibre substrates. As a result, the manufacturing productivity of erbium-doped optical fibre substrates is improved. Furthermore, the costs of erbiumdoped optical fibre substrates are greatly reduced.
Since oxygen is supplied to the interior of the quartz tube and heated at an appropriate temperature, the erbium solution absorbed in the quartz tube can be uniformly dried in the rotation direction of the quartz tube and in the longitudinal direction of the quartz tube.
Accordingly, it is possible to prevent irregular drying from occurring in the interior of the quartz tube. In addition, it is not necessary to use any additional heating device such as a heater because the interior of the quartz tube is dried by the heat source used for the deposition of the clad and core layers. Accordingly, it is possible to eliminate loss of time and process errors resulting from the installation of a separate heating device.
Claims (18)
1. Apparatus for manufacturing an erbium-doped optical fibre substrate comprising:
a clamping chuck for clamping a quartz tube; and
means for introducing a flow of heated gas through the quartz tube.
2. Apparatus according to claim 1 in which the clamping chuck is adapted to rotate the quartz tube and comprising:
a connecting tube adapted to connect the quartz tube to the clamping chuck;
a gas source for supplying gas to the interior of the quartz tube; and
a heat source for heating the gas introduced into the quartz tube.
3. Apparatus according to claim 1 or claim 2 in which the gas introduced into the quartz tube is oxygen.
4. Apparatus according to claim 2 in which the heat source is an oxygen/hydrogen burner which is supplied with hydrogen.
5. Apparatus for manufacturing an erbium-doped optical fibre substrate substantially as described with reference to and/or as illustrated in FIG. 4 of the accompanying drawings.
6. A method of manufacturing an erbium-doped optical fibre substrate comprising:
introducing into a quartz tube, having a clad layer deposited on its inner surface and a core layer deposited on the clad layer, a solution containing erbium;
allowing the core layer to absorb the solution and then removing the remaining solution from the quartz tube; and
introducing a flow of heated gas through the quartz tube to dry the solution which has been absorbed into the core layer of the quartz tube.
7. A method according to claim 6 comprising:
supplying raw material to the interior of the quartz tube;
rotating the quartz tube, while heating the quartz tube using an external heating source which reciprocates in a longitudinal direction on the quartz tube, to form a particle deposition on the inner surface of the quartz tube, sinter and transparentize the particle deposition to form a clad layer on the inner surface of the quartz tube;
supplying raw material to the interior of the quartz tube at a modified rate;
rotating the quartz tube, while heating the quartz tube using an external heating source which reciprocates in a longitudinal direction on the quartz tube, to form a particle deposition on the inner surface of the clad layer, sinter and transparentize the particle deposition to form a core layer on the inner surface of the clad layer.
8. A method according to claim 7 in which, during deposition of the clad and core layers, the quartz tube is connected at one end to a connecting tube which is in turn clamped in a clamping chuck but separated from the clamping chuck before introduction of the said solution.
9. A method according to claim 8 in which, during drying of the said solution absorbed into the core layer, the quartz tube is connected at one end to a connecting tube which is in turn clamped in a clamping chuck.
10. A method according to claim 9 in which the gas is heated by heating the connecting tube through which it passes before entering the quartz tube and rotating the clamping chuck.
11. A method according to claim 10 in which the temperature to which the connecting tube is heated is equal to or less than the volatilization temperature of nitric acid.
12. A method according to any of claims 6-11 in which one end of the quartz tube is closed before the said solution is introduced.
13. A method according to claim 12 in which the said one end of the quartz tube is opened again after the said solution is removed.
14. A method according to any of claims 6-13 in which the said solution contains other additive elements.
15. A method according to any of claims 6-14 further comprising heating the quartz tube after the solution has been dried to soften the quartz tube and sealing both ends of the quartz tube to provide an optical fibre substrate having a hollow cylindrical structure.
16. A method according to any of claims 6-15 in which the raw material supplied to the interior of the quartz tube comprises SiCl4, GeCl4 and 02.
17. A method according to any of claims 6-16 in which the gas introduced into the quartz tube is oxygen.
18. A method of manufacturing an erbium-doped optical fibre substrate substantially as described with reference to and/or as illustrated in FIG. 4 of the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019960009613A KR0167132B1 (en) | 1996-03-30 | 1996-03-30 | Method and apparatus of manufacturing fiber containing erbium |
| GB9706709A GB2311776B (en) | 1996-03-30 | 1997-03-27 | Method of and apparatus for manufacturing erbium-doped optical fibres |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9819690D0 GB9819690D0 (en) | 1998-11-04 |
| GB2325928A true GB2325928A (en) | 1998-12-09 |
| GB2325928B GB2325928B (en) | 2000-01-19 |
Family
ID=26311307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9819690A Expired - Fee Related GB2325928B (en) | 1996-03-30 | 1997-03-27 | Apparatus for manufacturing erbium-doped optical fibres |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2325928B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5131936A (en) * | 1988-06-27 | 1992-07-21 | Societa Italiana Per L'esercizio Delle Telecommicazioni P.A. | Apparatus for manufacture of a silica optical fiber |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0662311B2 (en) * | 1988-12-07 | 1994-08-17 | シツプ‐ソシエタ・イタリアーナ・ペル・レセルチツイオ・デル・テレコミニカイオーニ・ピー・アー | Method for doping the core of silica-based fiber preforms |
-
1997
- 1997-03-27 GB GB9819690A patent/GB2325928B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5131936A (en) * | 1988-06-27 | 1992-07-21 | Societa Italiana Per L'esercizio Delle Telecommicazioni P.A. | Apparatus for manufacture of a silica optical fiber |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2325928B (en) | 2000-01-19 |
| GB9819690D0 (en) | 1998-11-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6131415A (en) | Method of making a fiber having low loss at 1385 nm by cladding a VAD preform with a D/d<7.5 | |
| US6408652B1 (en) | Solution doping method of making an optical amplifying fiber | |
| US4203744A (en) | Method of making nitrogen-doped graded index optical waveguides | |
| US4389230A (en) | Process for improving the transmission characteristics of optical fibers drawn from preforms made by the MCVD technique | |
| US6125659A (en) | Apparatus for manufacturing erbium-doped optical fibers | |
| JPH0915464A (en) | Single-mode optical transmission fiber and its manufacture | |
| EP0611732B1 (en) | Process for fabricating an optical fiber preform | |
| JP4011418B2 (en) | Optical fiber manufacturing method and apparatus using improved oxygen stoichiometry and deuterium exposure | |
| US20150299022A1 (en) | Optical fiber preform manufacturing method, optical fiber preform, and optical fiber | |
| WO2007122630A2 (en) | Single mode optical fiber having reduced macrobending and attenuation loss and method for manufacturing the same | |
| JP2001510137A (en) | Reduced H2 sensitivity in optical fiber | |
| CN111470769A (en) | Preparation method of rare earth doped few-mode optical fiber | |
| GB2325928A (en) | Apparatus for manufacturing erbium-doped optical fibre preform | |
| JP2007508227A (en) | Method of manufacturing optical fiber and its preform | |
| US4553995A (en) | Process for producing image fiber | |
| EP1783104B1 (en) | Method of producing a preform for optical fibers | |
| KR20030093960A (en) | A preform and method for manufacturing same | |
| US20040118164A1 (en) | Method for heat treating a glass article | |
| JP4565221B2 (en) | Optical fiber preform | |
| KR20000031179A (en) | Preparation method of the preform for a low loss single mode optical fiber | |
| JPH03211504A (en) | Production of rare earth doped fiber and preform thereof | |
| JPH01203238A (en) | Production of optical fiber preform | |
| JPH0437623A (en) | Production of preform for optical fiber | |
| JP2002316824A (en) | Method for manufacturing glass article | |
| JP2004091261A (en) | Erbium-doped optical fiber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20070327 |