JPH08259251A - Manufacture of chalcogenide glass fiber - Google Patents

Abstract

PURPOSE: To prevent a glass from being volatilized and changed in composition due to heating at the time of spinning the glass fiber by subjecting the whole region or the region other than the tip of the periphery of a clad glass tube housing a core glass material to adhesion coating. CONSTITUTION: In this manufacture, a clad glass tube 2 housing a core glass rod 1 and an evacuation pipe 3 provided in the inside with a core glass rod fixing part 6 for preventing the rod 1 from being pushed up during the spinning of the glass fiber are integrally coated with a thermally shrinkable tube 4 being an adhesion coating material so as to cover the whole region of the tube 2 including its tip of the side to be heated and spun. The lower parts of rod 1, tube 2 and tube 4 are heated from the surroundings with a ring heater 7 and spun while maintaining the pressure of the space between the rod 1 and tube 2 at <=10<-1> Torr by using a vacuum pump connected to an evacuation port 5 of the evacuation pipe 3 to produce the objective glass fiber 8 that has a three-layer structure consisting of the core glass, clad glass and thermally shrinkable tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chalcogenide glass fiber having a core / clad structure.

[0002]

As a method for producing chalcogenide glass fibers, a chalcogenide glass rod for a core is inserted into a chalcogenide glass tube for a clad, and a quartz tube or crucible having a spinning hole at a lower end thereof is used. There is known a method in which a tip end of a quartz tube or a region below the quartz tube is locally heated to spin a fiber (JP-A 1-22).
6748).

However, this method requires an expensive quartz tube or crucible, and when manufacturing fibers having different fiber diameters, a plurality of quartz tubes or crucibles having spinning holes with different hole diameters are required. In addition to such problems, there are the following problems.

That is, it is known that the glass component of chalcogenide glass volatilizes by heating and its composition is apt to change. According to the above-mentioned method for producing chalcogenide glass fiber, the quartz tube or crucible and the glass for cladding are used. Since there is a space between the tube and the tube, volatilization and composition change due to heating of the chalcogenide glass occur during fiber production, and a chalcogenide glass fiber having desired properties cannot be obtained.

Therefore, the object of the present invention is (i) without using an expensive quartz tube or crucible, fibers having different fiber diameters can be freely produced depending on processing conditions, (ii)
It is an object of the present invention to provide a method for producing a chalcogenide glass fiber, which has advantages such as the ability to produce a chalcogenide glass fiber having desired properties by suppressing a composition change due to volatilization of the chalcogenide glass due to heating during spinning.

[0006]

Means for Solving the Problems The present invention that achieves the above object is to adhere the entire area around the chalcogenide glass tube for the clad containing the chalcogenide glass material for the core or the area excluding the end portion on the side of heat spinning. Adhesion coating with a coating material, which is the gist of a method for producing a chalcogenide glass fiber, characterized in that the tip portion or a lower portion thereof is locally heat-spun to obtain a fiber, the chalcogenide glass fiber of the present invention. According to the manufacturing method, it is possible to freely manufacture fibers having different fiber diameters according to processing conditions without using an expensive quartz tube or crucible. Further, the adhesion coating material which is adhered to the entire area around the glass tube for cladding or the area excluding the tip portion suppresses the composition change due to volatilization of the chalcogenide glass due to heating during spinning, and has chalcogenide having a desired property. Glass fibers can be manufactured.

The adhesion coating material may be made of any material as long as it has good adhesion to the glass tube for clad and can prevent volatilization of the chalcogenide glass due to heating during spinning. By using the shrinkable tube, the adhesion and covering property of the surrounding of the clad chalcogenide glass tube becomes particularly good, and the volatilization of the glass component from the clad chalcogenide glass can be significantly suppressed. In addition, since the opening of the heat shrink tube is generally smoother than that of the quartz glass tube, for example, the area excluding the tip of the clad glass tube containing the glass material for the core is closely covered with the heat shrink tube to form a clad tube. When the glass tube is heated and spun, it is possible to prevent the fiber from being scratched.

As a heat shrinkable tube, (a) Teflon F
Fluorine such as EP (tetrafluoroethylene-hexafluoropropylene copolymer), polyvinylidene fluoride, Teflon PFA (tetrafluoroethylene-perfluoroalkoxyethylene copolymer), Teflon TFE (polytetrafluoroethylene resin) Resin-based heat-shrinkable tube, (b) Silicone rubber-based heat-shrinkable tube, (c) Synthetic rubber-based heat-shrinkable tube such as neoprene and Viton, (d) Polyolefin-based heat-shrinkable tube such as cross-linked polyolefin, (e) Vinyl chloride-based Although heat-shrinkable tubes and the like can be mentioned, when a heat-shrinkable tube whose melting point or softening point is close to the melting point of chalcogenide glass is used, an adhesion coating to the chalcogenide glass tube for clad due to heat shrinkage of the heat-shrinkable tube,
It is preferable because the fiber spinning can be performed simultaneously. Examples of such heat-shrinkable tubes include fluororesins such as Teflon. Since this fluororesin has excellent heat permeability, the time required for heating is shorter than that of quartz glass, and it is also excellent in that the yield can be improved.

According to a preferred embodiment of the present invention, a pressure reducing tube is connected to the tip of the glass tube for clad on the side opposite to the side for heating and spinning, and a connecting portion between the glass tube for clad and the pressure reducing tube is provided with an adhesive coating material. Bubbles and foreign substances at the interface between the glass material for clad and the glass tube for clad by closely coating together with the glass tube for clad and reducing the gap between the glass material for clad and the glass tube for clad using a pressure reducing tube. Can be prevented from being mixed. The pressure in the gap between the core glass rod and the clad glass tube is preferably 10 -1 torr or less.
Orr or less is more preferable.

By providing a core glass material fixing portion for fixing the core glass material inside the decompression tube,
It is possible to prevent the glass material for cores from rising during spinning.

Further, the entire area around the clad glass tube containing the core glass material is closely coated with an adhesive coating material, and the clad glass tube containing the core glass material is heat-spun together with the adhesive coating material. ,
A protective coating layer made of an adhesive coating material can be formed on the fiber at the same time as the fiber is formed.

Further, when the periphery of the glass tube for cladding is heat-spun and is closely coated with an adhesive coating material, the fiber is obtained in a state where the fiber is not coated with the adhesive coating material after spinning. In this case, the fiber after spinning can be passed through the container containing the resin to form a protective coating layer made of the resin on the fiber. The resin used is preferably a UV curable resin, but is not limited to this as long as it has a fiber protection function, and a thermosetting resin or the like can be used.

In the present specification, chalcogenide glass is to be understood in the broadest sense, and the chalcogen elements S, Se and Te in the periodic table 6B group are the main components, and As,
A general term for glass containing P, Sb, Si, Ge, Sn and the like. Further, it is possible to apply the method of the present invention to glass having volatility such as fluoride glass.

[0014]

【Example】

[Embodiment 1] First, an embodiment of the present invention will be described with reference to FIG. The clad glass tube 2 accommodating the core glass rod 1 and the pressure reducing tube 3 were integrally covered with a heat-shrinkable fluororesin tube (Teflon FEP) 4. In this case, the heat-shrinkable fluororesin tube 4 was formed so as to cover the entire region of the clad glass tube including the tip on the side of heat spinning. A core glass rod fixing portion 6 was provided in the decompression tube 3 to prevent rising during spinning. The pressure in the gap between the core glass rod 1 and the clad glass tube 2 is reduced by the pressure reducing tube 3.
With a vacuum pump connected to the discharge port 5 of 10-3 to
Hold at rr.

The composition of the core glass rod 1 is As% at As.
47 S53 and the composition of the clad glass tube 2 is at%
As45S55. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ,
The outer diameter of the core glass rod 1 is 9.5 mmφ, and the core glass rod 1 and the clad glass tube 2 are integrated.
The lower part of the Teflon FEP 4 was heated to 390 ° C. by a ring heater 7 and spun to obtain a fiber 8 having an outer diameter of 300 μmφ. The fiber 8 has a three-layer structure of core glass, clad glass, and heat-shrinkable fluororesin.

2.4 μ of the fiber 8 thus obtained
The loss at the wavelength of m was 0.1 dB / m.

Example 2 The same method as in Example 1 was repeated except that the composition of the core glass rod 1 was G at at%.
e22As26Se52, and the composition of the clad glass tube 2 was Ge20As25Se55 at at%. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ, and the outer diameter of the core glass rod 1 is 9.5.
The core glass rod 1, the clad glass tube 2, and the heat-shrinkable fluororesin tube (vinylidene fluoride) 4 which are integrated with each other are heated to 485 ° C. by a ring heater 7 and spun to have an outer diameter of 300 μmφ. Fiber 8 was obtained.

The thus obtained fiber 8 having a three-layer structure of core glass, clad glass and heat-shrinkable fluororesin has a loss of 0.55 dB at a wavelength of 6 μm.
Was / m.

Example 3 The same method as in Example 1 was repeated, except that the composition of the core glass rod 1 was G at at%.
e23Se17Te60, and the composition of the clad glass tube 2 was Ge20Se21Te59 at at%. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ, and the outer diameter of the core glass rod 1 is 9.5.
The core glass rod 1, the clad glass tube 2, and the heat-shrinkable resin tube (Teflon F
EP) 4 around the lower part by a ring-shaped heater 7
The fiber 8 having an outer diameter of 300 μmφ was obtained by heating at 30 ° C. and spinning.

In the fiber 8 thus obtained, which has a three-layer structure of core glass, clad glass and heat-shrinkable fluororesin, the loss at a wavelength of 8 μm is 0.55 dB.
Was / m.

[Embodiment 4] Another embodiment of the present invention will be described with reference to FIG. The clad glass tube 2 accommodating the core glass rod 1 and the pressure reducing tube 3 were integrally covered with a heat-shrinkable resin tube (Teflon FEP) 4. In this case, the heat-shrinkable fluororesin tube was made to cover the region of the clad glass tube excluding the tip portion in the example of heat spinning. A core glass rod fixing portion 6 was provided in the decompression tube 3 to prevent rising during spinning.

The pressure in the gap between the core glass rod 1 and the clad glass tube 2 was kept at 10 -5 torr by a vacuum pump connected to the discharge port 5 of the pressure reducing tube 3.

The composition of the core glass rod 1 is As at%.
47 S53 and the composition of the clad glass tube 2 is at%
As45S55. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ,
The outer diameter of the core glass rod 1 is 9.5 mmφ, and the core glass rod 1 and the clad glass tube 2 are integrated.
Of the heat-shrinkable fluororesin tube 4, the lower end portions of the core glass rod 1 and the clad glass tube 2 are heated by an annular heater 7 in an inert gas atmosphere to
By heating to 0 ° C., spinning, and then passing the resin coating cup 9 filled with the UV curable resin 10, an outer diameter of 340 μm
A fiber 8 having mφ and a cladding diameter of 300 μmφ was obtained.
Fiber 8 is core glass, clad glass and UV
It has a three-layer structure of cured resin.

2.4 μ of the fiber 8 thus obtained
The loss at the wavelength of m was 0.1 dB / m.

Example 5 The same method as in Example 4 was repeated, except that the composition of the core glass rod 1 was G at at%.
e22As26Se52, and the composition of the clad glass tube 2 was Ge20As25Se55 at at%. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ, and the outer diameter of the core glass rod 1 is 9.5.
In the core glass rod 1, the clad glass tube 2, and the heat-shrinkable fluororesin tube (vinylidene fluoride) 4, which are integrated with each other, the circumference of the lower end of the core glass rod 1 and the clad glass tube 2 is surrounded by a ring heater 7. , Heated to 485 ° C., spun, and then passed through a resin coating cup 9 filled with a UV curable resin (urethane acrylate resin) 10 to give an outer diameter of 340 μm.
A fiber 8 having a diameter of φ and a cladding diameter of 300 μm was obtained. The fiber 8 has a three-layer structure of core glass, clad glass, and UV curable resin.

The fiber 8 thus obtained had a loss of 0.55 dB / m at a wavelength of 6 μm.

Example 6 The same method as in Example 4 was repeated, except that the composition of the core glass rod 1 was at% G.
e23Se17Te60, and the composition of the clad glass tube 2 was Ge20Se21Te59 at at%. At this time, the outer diameter of the clad glass tube 2 is 12.5 mmφ, the inner diameter is 10.5 mmφ, and the outer diameter of the core glass rod 1 is 9.5.
The core glass rod 1, the clad glass tube 2, and the heat-shrinkable resin tube (Teflon F
In EP) 4, the periphery of the lower tip portion of the core glass rod 1 and the clad glass tube 2 was heated and spun at 430 ° C. by a ring-shaped heater 7 to obtain a fiber 8 having an outer diameter of 300 μmφ. The fiber 8 is made of core glass and clad glass.

The fiber thus obtained had a loss of 0.55 dB / m at a wavelength of 8 μm.

[Seventh Embodiment] Unlike the first to sixth embodiments,
Examples of the present invention for obtaining fibers after manufacturing a preform will be described. The composition of the core glass 1a is Ge23S in at%
A preform in which the composition of the cladding glass 2a was Ge20Se21Te59 at at% was prepared by the following method. A tube-shaped clad glass is placed in a quartz glass tube, a cylindrical core glass is further placed in the clad glass, and the gap between the core glass and the clad glass is depressurized. While pressing the gap with the glass tube, the outside of the quartz glass tube is heated by a ring heater to fuse the core glass and the clad glass, and as shown in FIG. 3, a core composed of the core glass 1a and the clad glass 2a. A clad-integrated preform 11 was prepared. In the preform 11 thus produced, the outer diameter of the clad glass 2a was 12.5 mmφ and the diameter of the core glass 1a was 9.5 mmφ. The core / clad integrated preform 11 is covered with a heat-shrinkable fluororesin tube (Teflon FEP) 4 except for the tip portion to be heated and spun,
The core-clad integrated preform 11 is heated around its lower tip to 430 ° C. by a ring heater 7 and spun, and then passed through a resin coating cup 9 filled with a UV curable resin (urethane acrylate resin) 10. Thus, a fiber 8 having an outer diameter of 340 μmφ and a cladding diameter of 300 μmφ was obtained. The fiber 8 has a three-layer structure of a core glass, a clad glass and a UV curable resin.

The fiber 8 thus obtained had a loss of 0.55 dB / m at a wavelength of 8 μm.

[0031]

According to the present invention, an expensive quartz tube or crucible is used by heating and spinning the cladding glass tube accommodating the glass material for the core in a state where the glass tube for the cladding is covered with the adhesive coating material. Moreover, chalcogenide glass fibers having different fiber diameters can be freely spun depending on the spinning conditions. Further, since the glass tube for cladding is adhered and coated with the adherent coating material, volatilization and composition change of the glass can be prevented, so that chalcogenide glass fiber having desired properties can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method of manufacturing chalcogenide glass fibers according to Examples 1 to 3.

FIG. 2 is a cross-sectional view showing a method for manufacturing a chalcogenide glass fiber according to Examples 4 to 5.

FIG. 3 is a cross-sectional view showing a method for manufacturing a chalcogenide glass fiber according to Example 7.

[Explanation of symbols]

 1 core glass rod 1a core glass 2 clad glass tube 2a clad glass 3 decompression tube 4 heat shrinkable fluororesin tube 5 discharge port 6 core glass rod fixing part 7 ring-shaped heater 8 fiber 9 resin coating cup 10 coating resin 11 preform

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiharu Yamashita 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Hoya Co., Ltd.

Claims (8)

[Claims] 1. An entire area around a chalcogenide glass tube for a clad containing a chalcogenide glass material for a core or an area excluding a tip portion on a side of heat-spinning is tightly covered with an adhesion coating material, and the tip portion or a lower portion thereof is covered. A process for producing a chalcogenide glass fiber, which comprises locally heating and spinning the fiber. 2. The method for producing a chalcogenide glass fiber according to claim 1, wherein the adhesion coating material is a heat-shrinkable tube. 3. The chalcogenide glass fiber according to claim 2, wherein the heat-shrinkable tube is a fluororesin-based, silicone rubber-based, synthetic rubber-based, polyolefin-based or vinyl chloride-based heat-shrinkable resin tube. Production method. 4. A pressure reducing tube is used by connecting a decompression pipe to the tip of the glass tube for clad opposite to the side on which heat-spinning is performed, and the connecting portion between the glass tube for clad and the pressure reducing tube is tightly covered with an adhesion coating material. The method for producing a chalcogenide glass fiber according to any one of claims 1 to 3, wherein the gap between the glass material for core and the glass tube for cladding is depressurized. 5. The method for producing a chalcogenide glass fiber according to claim 1, wherein a core glass material fixing portion for fixing the core glass material is provided inside the decompression tube. . 6. A clad glass tube accommodating a glass material for a core is adhered to the entire area around the clad glass tube with an adherent coating material, and the glass tube for a clad containing the glass material for core is heat-spun together with the adherent coating material. The method for producing a chalcogenide glass fiber according to any one of claims 1 to 5, wherein a protective coating layer made of an adhesion coating material is formed on the fiber simultaneously with the formation of the fiber. 7. A clad glass tube containing a glass material for a core is closely coated on a region excluding a tip portion on a side to be heated and spun, and only a glass tube for clad containing a glass material for a core is heated and spun. The chalcogenide glass fiber according to any one of claims 1 to 5, characterized in that the fiber thus obtained is passed through a container containing a resin to form a protective coating layer made of the resin on the fiber. Production method. 8. The resin for coating the fiber is UV
A method for producing a chalcogenide glass fiber according to claim 7, which is a cured resin.