JP4159528B2 - Fixing method of optical fiber - Google Patents

Description

  The present invention relates to an optical fiber fixing method, and more particularly to an optical fiber fixing method having excellent heat resistance.

  Conventionally, an optical fiber is fixed using a plastic resin or a ceramic resin having a small linear expansion coefficient (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-125846

For example, high heat resistance is required in applications where a large number of optical fiber coils are installed in a rock near a magma of a volcano, and vibrations, temperatures, etc. are measured by these optical fiber coils.
Therefore, an object of the present invention is to provide an optical fiber fixing method having excellent heat resistance.

In a first aspect, the present invention provides an optical fiber in which a silica microporous material solution containing silicon as a main component is applied and dried so as to adhere to both the optical fiber (101) and the fixed part (105). An optical fiber fixing method is provided in which (101) is fixed to a fixed part (105).
In the optical fiber fixing method according to the first aspect, the silica microporous body solution is dried to form the silica microporous body (102), and the optical fiber (101) is fixed to the fixed part (105). . Since this silica microporous body (102) has silicon dioxide as a main component, high heat resistance can be obtained.

In a second aspect, the present invention provides an optical fiber fixing method configured as described above, wherein the optical fiber (101) includes an optical fiber (1) including a core (1a) and a clad (1d), and the optical fiber ( An optical fiber fixing method comprising: a heat-resistant optical fiber including a silica microporous film (2) mainly composed of silicon formed on an outer peripheral surface of 1).
In the optical fiber fixing method according to the second aspect, the micropores of the silica microporous membrane (2) formed in the optical fiber (101) have a buffering action, and many microcracks exist in the cladding (1d). It is buffered and suppressed that it grows and breaks easily when the optical fiber (101) is bent. For this reason, bending strength can be improved. And since a silica microporous film (2) has silicon dioxide as a main component, it has high heat resistance. Therefore, it is suitable for an application in which the fixed part (105) is very hot.

In a third aspect, the present invention provides a heat resistance method in which the optical fiber (101) is formed with a metal coating (3) on the outer peripheral surface of the silica microporous membrane (2) in the optical fiber fixing method having the above-described configuration. An optical fiber fixing method characterized by being an optical fiber is provided.
In the optical fiber fixing method according to the third aspect, since the metal coating (3) is provided on the outer periphery of the silica microporous membrane (2), it has higher heat resistance. Therefore, it is suitable for an application in which the fixed part (105) is very hot.

In a fourth aspect, the present invention provides the method for fixing an optical fiber having the above-described configuration, wherein the silica microporous material solution is a sol-gel from a mixture of silicon alkoxide, an active alcohol that promotes a hydrolysis reaction, an alcohol, and water. An optical fiber fixing method characterized by being synthesized by a method.
In the optical fiber fixing method according to the fourth aspect, since the silica microporous material solution is synthesized by the sol-gel method, the manufacturing cost can be reduced.

In a fifth aspect, the present invention provides an optical fiber fixing method characterized in that, in the optical fiber fixing method configured as described above, the fixed portion (105) is a part of a ceramic material.
In the optical fiber fixing method according to the fifth aspect, since the fixed portion (105) is a part of a ceramic material such as alumina, ceramics, concrete, or rock, it has high heat resistance.

  According to the method for fixing an optical fiber of the present invention, since the silica microporous body (102) contains silicon as a main component, extremely excellent heat resistance can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a perspective view illustrating an optical fiber fixing method according to the first embodiment.
The optical fiber 101 is placed in close contact with the fixed portion 105. Then, a silica microporous material solution containing silicon as a main component is applied so as to adhere to both the optical fiber 101 and the fixed portion 105, and is heated and dried to form a silica microporous material 102. Is fixed to the fixed portion 105.
The fixed portion 105 is a part of a ceramic material such as alumina, ceramic, concrete, or rock.

  As a numerical example, the outer diameter of the optical fiber 101 is about 166 μm. The thickness of the silica microporous body 102 is about 200 μm.

  As shown in FIG. 2, an optical fiber 101 is formed by forming a silica microporous film 2 mainly composed of silicon on the outer peripheral surface of a quartz or glass optical fiber 1 composed of a core 1a and a cladding 1d. This is a heat-resistant optical fiber in which a metal coating 3 of gold, silver, platinum, palladium, rhodium, chromium, bismuth, thorium or the like or an alloy thereof is formed on the outer peripheral surface of the microporous film 2.

  As a numerical example, the diameter of the core 1a is 10 μm, and the diameter of the cladding 1d is 125 μm. The silica microporous membrane 2 has a thickness of about 500 nm (= 0.5 μm), and has a large number of micropores having a pore diameter of 2 nm or less on the outer peripheral surface. The metal coating 3 has a thickness of 20 μm or less. 50% or more of the composition of the metal thin film 3 is a metal component.

FIG. 3 is a flowchart showing a synthesis process of a silica microporous solution by a sol-gel method.
In step S1, a mixture of silicon alkoxide and active alcohol that promotes hydrolysis reaction, alcohol and water is prepared.
The silicon alkoxide is, for example, TMOS (tetramethoxysilane) or TEOS (tetraethylorthosilicate).
Active alcohols that promote the hydrolysis reaction are, for example, hydroxyacetone, 1-penten-3-ol, acetone cyanohydrin, and the like.
The alcohol is, for example, methanol, ethanol, propanol, phthalanol or the like.

In step S2, the mixed solution is stirred.
In step S3, a salt catalyst is added to the mixed solution.
In step S4, the mixed solution is stirred.
As described above, a silica microporous material solution can be synthesized.
The method of synthesizing the silica microporous material solution has been announced in “The 34th Autumn Meeting of the Chemical Engineering Society, 2001”. Moreover, it is described in Japanese Patent Application No. 2003-83915.

  The optical fiber 101 is applied to the optical fiber 1 drawn from the preform of the heating furnace by applying a silica microporous solution at a silica microporous solution application portion, and baking at the baking portion to form a silica microporous film 2. An organic metal liquid or an organic metal paste is applied to the outer periphery of the silica microporous film 2 in the organic metal application part, and is baked in the baking part to form the metal film 3.

  The organic metal liquid or the organic metal paste is a gold liquid, a liquid or pasty noble metal composition for painting, a gold resinate paste, an Ag metalloorganic paste, a palladium-containing organic composition paste, or the like.

The gold solution is commercially available, for example, from Nippon Gold Solution Co., Ltd. (Kasugai City, Aichi Prefecture) as a gold solution with a top picture.
Further, liquid or paste-like noble metal compositions for painting are described in, for example, Japanese Patent Publication No. 7-6067.
The gold resinate paste is described in, for example, Japanese Patent No. 3203672.
Further, Ag metalloorganic paste is described in, for example, Japanese Patent Application Laid-Open No. 10-204297.
The palladium-containing organic composition paste is described in, for example, Japanese Patent No. 3232057.

  To give one specific example, a gold solution HY-1991 (trade name) manufactured by Nippon Gold Liquid Co., Ltd. is applied at an organic metal application part, dried at 150 ° C. for 5 minutes and baked at 600 ° C. for 5 minutes. As a result, a 0.1 μm thick metal coating 3 (90% or more of gold, including rhodium, chromium, bismuth, thorium, etc.) is formed.

  According to the fixing method of the optical fiber of Example 1, since the silica microporous body 102 contains silicon as a main component, extremely excellent heat resistance can be obtained.

  As the optical fiber 101, a heat-resistant optical fiber in which the metal coating 3 is omitted from the optical fiber 101 of FIG.

  As the optical fiber 101, the optical fiber 1 made of quartz or glass composed of the core 1a and the clad 1d may be used as it is.

  The optical fiber fixing method of the present invention can be used as an optical fiber coil fixing method for detecting vibrations or the like in a high temperature environment such as a rock near a volcanic magma.

1 is a perspective view showing an optical fiber fixing method according to Embodiment 1. FIG. 1 is a cross-sectional view of an optical fiber according to Example 1. FIG. It is a flowchart which shows the synthetic | combination process of the silica microporous body solution by a sol-gel method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 1a Core 1d Clad 2 Silica microporous body film 101 Optical fiber 102 Silica microporous body 105 Fixed part

Claims (5)

  The silica microporous material solution containing silicon as a main component is applied so as to adhere to both the optical fiber (101) and the fixed part (105), and dried, so that the optical fiber (101) is fixed to the fixed part (105). An optical fiber fixing method characterized by fixing to an optical fiber.   The optical fiber fixing method according to claim 1, wherein the optical fiber (101) is formed on an optical fiber (1) comprising a core (1a) and a clad (1d) and on an outer peripheral surface of the optical fiber (1). A method for fixing an optical fiber, comprising a heat-resistant optical fiber comprising a silica microporous film (2) containing silicon as a main component.   3. The optical fiber fixing method according to claim 2, wherein the optical fiber (101) is a heat-resistant optical fiber in which a metal coating (3) is formed on an outer peripheral surface of the silica microporous membrane (2). An optical fiber fixing method.   The optical fiber fixing method according to any one of claims 1 to 3, wherein the silica microporous material solution is formed from a mixture of silicon alkoxide, an active alcohol that promotes a hydrolysis reaction, an alcohol, and water. An optical fiber fixing method characterized by being synthesized by a method.   The optical fiber fixing method according to any one of claims 1 to 4, wherein the fixed portion (105) is a part of a ceramic material.

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