JP2009270844A - Live line detection device for optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection efficiency and detection accuracy in a live line detection device for an optical fiber. <P>SOLUTION: This device is equipped with a first support body 1 for supporting an optical fiber 3 on the incident side, a second support body 2 for supporting an optical fiber 4 on the emission side, and a photodetection element 5 for detecting light. The first support body 1 and one end face of the optical fiber 3 form an inclined plane having a tilt angle of 45 degrees, and the second support body 2 and one end face of the optical fiber 4 also form an inclined plane having a tilt angle of 45 degrees. The first support body 1 and the second support body 2 are allowed to adhere to each other with an adhesive in the form wherein each end face (each inclined plane 7, 8) of both optical fibers 3, 4 faces each other approximately in parallel. Hereby, since the width of an adhesive layer 9 is not regulated by the thickness of a dicing blade, the width of the adhesive layer 9 can be easily narrowed furthermore than the width of an inclined groove as in a conventional example, to thereby suppress scattered light. Consequently, detection efficiency and detection accuracy can be improved. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a hot-wire detection device that detects whether or not an optical fiber is in a hot-wire state.

  In recent years, optical fibers have been rapidly spreading as communication lines, and optical fiber cables drawn into optical communication stations of optical communication companies and general office buildings can be used for many optical fiber cords for optical wiring in a station or building. An optical termination box (also referred to as an optical termination tray) is used to connect to the cable. In addition, this type of optical termination box is equipped with a hot-wire detection device that detects whether or not each core wire (optical fiber core wire) of the optical fiber cord is in a live-wire state (a state in which an optical signal is transmitted). Has been.

A conventional hot-wire detection device is described in Patent Document 1. As shown in FIG. 8A, the conventional apparatus includes an optical waveguide in which a core layer 510 and upper and lower cladding layers 503 and 502 covering the core layer 510 are formed on a silicon substrate 501, and the optical waveguide is provided. The core layer 510 and the clad layers 502 and 503 are formed with inclined grooves by dicing, and the inclined grooves are filled with a transparent resin 511, and a part of the optical signal propagating through the core layer 510 is inclined. The light reflected by the reflecting mirror 512 using the side surface of the groove is received by the light receiving unit 507 of the light detecting element 506.
JP 2001-13339 A

  By the way, in the conventional example described in Patent Document 1, since the inclined grooves are formed in the core layer 510 and the cladding layers 502 and 503 by dicing, the inclined grooves have a width dimension about the thickness of the dicing blade. ing. For example, Patent Document 1 describes that the width of the inclined groove is 20 μm, which is about twice as large as the thickness of the cladding layers 502 and 503 (10 μm). When the width of the inclined groove is increased as described above, the light propagating through the core layer 510 is scattered in the transparent resin 511 filled in the inclined groove as shown in FIG. There is a risk that the detection efficiency will be reduced due to a decrease in the amount of reflected light that reaches. However, in the conventional example, since the width of the inclined groove is determined by the thickness of the dicing blade, it is not easy to reduce the width. In addition, a phenomenon (so-called crosstalk) in which an optical signal propagating through one of the optical waveguides is erroneously detected by the light receiving unit 507 corresponding to the adjacent optical waveguide due to the influence of the scattered light occurs, and the detection accuracy is reduced. There is a risk of it.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical fiber hot-line detection device capable of improving detection efficiency and detection accuracy.

  In order to achieve the above object, the invention of claim 1 is a hot-wire detection device that detects whether or not an optical fiber is in a hot-wire state, and a first support that supports the incident-side optical fiber; A second support for supporting the optical fiber on the emission side and a light detecting element for detecting light, and one end face of the first support and the optical fiber on the incident side is incident on the normal direction of the end face An inclined surface having an acute angle with the axial direction of the optical fiber on the side, and one end surface of the second support and the optical fiber on the output side has a normal direction of the end surface and an axial direction of the optical fiber on the output side. It is an inclined surface having an acute angle, and the first support and the second support are translucent adhesives in such a manner that the one end faces of the optical fibers on both the incident side and the output side face each other substantially in parallel. The photodetecting element is bonded to the one of the incident side and the outgoing side optical fibers. Characterized in that it is disposed on the optical path of the reflected light reflected at the interface between the end face and the adhesive layer.

  According to the first aspect of the present invention, since the width of the adhesive layer is not restricted by the thickness of the dicing blade, the width of the adhesive layer can be easily narrower than the width of the inclined groove in the conventional example, and scattered light is suppressed. Can do. As a result, detection efficiency and detection accuracy can be improved.

  According to a second aspect of the present invention, in the first aspect of the invention, an angle formed between a normal direction of the inclined surface and an axial direction of the optical fiber is approximately 45 degrees.

  According to the second aspect of the present invention, since the axial direction of the optical fiber and the optical path of the reflected light are substantially orthogonal, the detection efficiency of the light detection element can be further improved.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the first support, the second support, and the incident side are separated by dividing one optical fiber and one support that supports the one optical fiber. The optical fiber and the optical fiber on the emission side are formed, and the angle formed by the normal direction of the cross section and the axial direction of the optical fiber is equal to the angle of the inclined surface.

  According to the invention of claim 3, axial alignment between the incident side optical fiber and the outgoing side optical fiber can be easily performed.

  According to a fourth aspect of the present invention, in the third aspect of the invention, the cross section is polished.

  According to the fourth aspect of the present invention, it is possible to further improve the detection efficiency and the detection accuracy by reducing the light scattering in the cross section as compared with the case of not polishing.

  According to a fifth aspect of the present invention, in the first or second aspect of the present invention, one optical fiber and one support that supports the one optical fiber are divided in a direction substantially perpendicular to the axial direction of the optical fiber, and The first support body, the second support body, the incident side optical fiber, and the output side optical fiber are formed by polishing the cross section to form the inclined surface.

  According to the fifth aspect of the present invention, it is possible to easily form the first support body, the second support body, the incident side optical fiber, and the output side optical fiber as compared with the case where the inclined surface is formed at the time of dividing. it can.

  The invention of claim 6 is the invention of any one of claims 1 to 5, wherein the refractive index of the adhesive forming the adhesive layer is lower than the refractive indexes of the cores of the optical fibers on the incident side and the outgoing side. It is characterized by.

  According to the sixth aspect of the invention, the detection efficiency can be further improved by suppressing the reflected light propagating through the adhesive layer.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the first support body and the second support body are a plurality of strips in which a plurality of optical fibers are fitted so that their axial directions are aligned. It is characterized by having a fixed groove.

  According to the seventh aspect of the present invention, the axial alignment between the incident side optical fiber and the outgoing side optical fiber can be easily performed.

  According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the light detection element is disposed at a position facing the fixed groove with the optical fiber interposed therebetween, and the antireflection for preventing reflection of light on the surface of the fixed groove. A film is formed.

  According to the eighth aspect of the present invention, the detection accuracy can be suppressed by suppressing the phenomenon (so-called crosstalk) in which scattered light generated at the interface is reflected on the surface of the fixed groove and reaches the adjacent photodetecting element and is erroneously detected. Can be improved.

  The invention of claim 9 is the invention of any one of claims 1 to 8, wherein a light-shielding film is formed at a portion excluding the optical path of the reflected light between the light detection element and the optical fiber on the incident side and the outgoing side. It is characterized by being.

  According to the ninth aspect of the invention, since the scattered light generated at the interface is shielded by the light shielding film, the phenomenon (so-called crosstalk) in which the scattered light reaches the adjacent photodetector and is erroneously detected is suppressed. The detection accuracy can be improved.

  A tenth aspect of the present invention is the optical fiber according to any one of the first to ninth aspects, wherein a reflection film is formed on the outer peripheral surface of the incident-side or emission-side optical fiber that faces the photodetecting element across the core. It is characterized by being.

  According to the invention of claim 10, since the scattered light generated at the interface is reflected by the reflection film and reaches the light detection element, the detection efficiency can be further improved.

  According to the present invention, detection efficiency and detection accuracy can be improved.

  Embodiments of an optical fiber hot-wire detection apparatus according to the present invention will be described below in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the hot-wire detection apparatus of the present embodiment includes a first support 1 that supports four optical fibers 3 on the incident side and a second support that supports four optical fibers 4 on the output side. A body 2 and a light detection element 5 for detecting light are provided.

  The first support 1 includes a fixed groove 11 between a V-groove substrate 10 having four fixed grooves (V-grooves) 11 having a V-shaped cross section formed on the surface in parallel and at equal intervals, and the V-groove substrate 10. And a cover 12 that holds the optical fiber 3 fitted into the cover. Similarly, the second support 2 is fixed between the V-groove substrate 20 and four V-groove substrates 20 having four fixed grooves (V-grooves) 21 having a V-shaped cross section formed on the surface in parallel and at equal intervals. And a cover 22 that holds the optical fiber 4 fitted in the groove 21. The V-groove substrates 10 and 20 are made of a silicon substrate, and fixed grooves 11 and 20 are formed on the main surface (surface) by anisotropic etching using an alkaline aqueous solution such as KOH (potassium hydroxide) or TMAH (tetramethylammonium hydroxide). 21 is formed. However, the V-groove substrates 10 and 20 may be formed of quartz, metal, or polymer material, and the fixed grooves 11 and 21 may be formed by machining such as cutting.

  The covers 12 and 22 are transparent and are formed in a flat plate shape with a material having a higher refractive index than the clads 31 and 41 of the optical fibers 3 and 4. The covers 12 and 22 are adhered to the main surfaces (front surfaces) of the V-groove substrates 10 and 20 by an adhesive 6 filled in the fixing grooves 11 and 21 in order to fix the optical fibers 3 and 4 (FIG. 1 (c)).

  Thus, since the optical fibers 3 and 4 are hold | maintained by fitting in the fixed grooves 11 and 21 which consist of V-grooves, the positional accuracy of the multiple optical fibers 3 and 4 can be raised easily. In addition, since the individual optical fibers 3 and 4 are supported from the three directions by the both side surfaces of the fixing grooves 11 and 21 and the covers 12 and 22, rattling of the optical fibers 3 and 4 can be eliminated.

  One end face (the right end face in FIG. 1B) of the first support 1 and the incident-side optical fiber 3 has a normal direction to the end face and an axial direction of the incident-side optical fiber 3 (FIG. 1B). ) Is formed as an inclined surface 7 having an acute angle (45 degrees in this embodiment). Also, one end face (the left end face in FIG. 1B) of the second support 2 and the output side optical fiber 4 is in the normal direction of the end face and the axial direction of the output side optical fiber 4 (FIG. 1). It is formed as an inclined surface 8 having an acute angle (45 degrees in this embodiment). And the 1st support body 1 and the 2nd support body 2 are adhere | attached with the adhesive which has translucency in the form in which the inclined surfaces 7 and 8 oppose substantially parallel, The inclined surface 7 of the 1st support body 1 is provided. And an inclined surface 8 of the second support 2, an adhesive layer 9 made of the adhesive is interposed.

  The photodetector 5 has a rectangular semiconductor substrate 50 having a longitudinal dimension substantially equal to the width dimension of the first support 1 and the second support 2 (the vertical dimension in FIG. 1A). And a photodiode array having four light receiving portions 51 formed in a line in the longitudinal direction at the center in the short direction of the semiconductor substrate 50. The pitch (interval) of the light receiving portions 51 in the longitudinal direction of the semiconductor substrate 50 is the same as the pitch (interval) of the cores 30 and 40 in the optical fibers 3 and 4 supported by the first support 1 and the second support 2. They are almost coincident (see FIG. 1C). Further, on the surfaces of the covers 12 and 22 of the first support 1 and the second support 2, the optical fibers are viewed from the thickness direction of the first support 1 and the second support 2 (vertical direction in FIG. 1B). The light detection element 5 is disposed at a position where the four light receiving portions 51 overlap each other at the interface between the end faces of the cores 30 and 40 and the adhesive layer 9, and has a higher refractive index than the material forming the covers 12 and 22. It is mounted (die-bonded) on the surface of the covers 12 and 22 with an adhesive.

  Thus, a part of the light (optical signal) propagating through the optical fiber 3 on the incident side is part of the axis of the optical fibers 3 and 4 at the interface between the inclined surface 7 and the adhesive layer 9 and the interface between the adhesive layer 9 and the inclined surface 8. Reflected in a direction perpendicular to the direction (left and right direction in FIG. 1B), the reflected light (reflected light) enters the light receiving portion 51 of the light detection element 5 disposed on the optical path. . Therefore, since a current signal corresponding to the amount of reflected light is output from the light detection element 5, the live line state of the optical fibers 3 and 4 can be detected according to the magnitude of the current signal. Here, in this embodiment, since the 1st support body 1 and the 2nd support body 2 are joined via the contact bonding layer 9, the end surface of the optical fiber 3 supported by the 1st support body 1 and a 2nd support The distance from the end face of the optical fiber 4 supported by the body 2 (the thickness of the adhesive layer 9) can be sufficiently narrower than the width of the inclined groove in the conventional example. This is because, in the conventional example, the width of the inclined groove is determined by the thickness of the dicing blade for forming the inclined groove, but in this embodiment, the thickness of the adhesive layer 9 can be made sufficiently smaller than the thickness of the dicing blade. Because it can.

  As described above, in the live line detection device of the present embodiment, since the width of the adhesive layer 9 is not restricted by the thickness of the dicing blade, the width of the adhesive layer 9 can be easily narrower than the width of the inclined groove in the conventional example. Scattered light can be suppressed. In addition, the detection efficiency can be improved by suppressing the scattered light, and the reflected light reflected at the interface between the end face of one of the optical fibers 3 and 4 and the adhesive layer 9 corresponds to another adjacent optical fiber 3 or 4. The detection accuracy can be improved by reducing the phenomenon (crosstalk) received by the light receiving section 51. If the refractive index of the adhesive forming the adhesive layer 9 is higher than the refractive index of the cores 30 and 40 of the optical fibers 3 and 4, the interface between the adhesive layer 9 and the end face of the optical fiber 4 is shown in FIG. A part of the reflected light (see the broken line arrow b in FIG. 2) (see the broken line arrow b in FIG. 2) is propagated to the adhesive layer 9, so that the amount of reflected light incident on the light receiving portion 51 is reduced. As a result, the detection efficiency is lowered. Therefore, it is necessary to use an adhesive having a refractive index lower than that of the cores 30 and 40 of the optical fibers 3 and 4 as an adhesive for forming the adhesive layer 9. The amount of reflected light can be easily adjusted by increasing or decreasing the difference (refractive index difference) between the refractive index of the adhesive forming the adhesive layer 9 and the refractive indexes of the cores 30 and 40 of the optical fibers 3 and 4. it can.

  Here, in this embodiment, the inclination angle of the inclined surfaces 7 and 8 (the angle formed by the normal direction of the inclined surfaces 7 and 8 and the axial direction of the optical fibers 3 and 4; the same applies hereinafter) is set to 45 degrees. Therefore, the optical path of the reflected light is orthogonal to the axial direction of the optical fibers 3 and 4. On the other hand, since the surfaces of the covers 12 and 22 on which the light detecting element 5 is mounted are parallel to the axial direction of the optical fibers 3 and 4, the light receiving surface of the light receiving portion 51 of the light detecting element 5 (the lower surface in FIG. 2). As a result, the reflected light is incident vertically, and efficient detection becomes possible. In addition, when the light receiving unit 51 is disposed on the optical path of the reflected light, the cores 30 of the optical fibers 3 and 4 as viewed from the thickness direction (vertical direction in FIG. 2) of the first support 1 and the second support 2 Since the four light receiving portions 51 only need to overlap each other at the interface between the end face of 40 and the adhesive layer 9, the positioning can be easily performed, and the mounting process of the light detection element 5 can be simplified to reduce the manufacturing cost. Can be reduced.

  By the way, in this embodiment, as shown to Fig.3 (a)-(c), the 1st optical fiber 110 and the 1st support body 1 by dividing | segmenting the 1 support body 100 which supports the said 1 optical fiber 110 are separated. The second support 2, the incident side optical fiber 3 and the output side optical fiber 4 are formed. That is, as shown in FIG. 3A, the support body 100 includes a V-groove substrate 101 and a cover 102, and the optical fiber 110 is fitted into the fixed groove 103 formed in the V-groove substrate 101 and the V-groove substrate 101 is fitted. The optical fiber 110 is sandwiched and supported between the cover 102 to be attached.

  If the support 100 and the optical fiber 110 configured as described above are diced from a direction inclined by 45 degrees with respect to the axial direction of the optical fiber 110, a cross section (inclined surfaces 7, 8) Two portions where the angle between the normal direction and the axial direction of the optical fibers 3 and 4 is 45 degrees, that is, the first support 1 and the incident-side optical fiber 3 and the second support 2. And the optical fiber 4 on the emission side. And as already demonstrated, the 1st support body 1 and the 2nd support body 2 are adhere | attached with an adhesive agent in the form in which the inclined surfaces 7 and 8 oppose substantially parallel (refer FIG.3 (c)). At this time, if the first support body 1 and the second support body 2 are combined with the bottom surfaces of both V-groove substrates 10 and 20 as the reference plane, the support body 100 is originally divided, so that the support The optical fibers 3 and 4 can be easily aligned in the thickness direction of the bodies 1 and 2 (vertical direction in FIG. 3C). Incidentally, in order to suppress the scattered light on the inclined surfaces 7 and 8 and reduce the loss of the reflected light, it is desirable to polish the cross section of the optical fibers 3 and 4.

  Note that the cutting method of dicing from the direction inclined 45 degrees with respect to the axial direction of the optical fiber 110 as described above is not general-purpose, and the acute angles at which the thicknesses of the supports 1 and 2 and the optical fibers 3 and 4 are reduced. Defects due to chipping are likely to occur at the portions. Therefore, as shown in FIGS. 4A and 4B, the support body 100 that supports the optical fiber 110 is divided in a direction substantially orthogonal to the axial direction of the optical fiber 110 by dicing, and the cross section is further polished. If the inclined surfaces 7 and 8 are formed to form the first support 1 and the second support 2 as well as the incident-side optical fiber 3 and the exit-side optical fiber 4, no defects due to chipping occur. Further, as compared with the case of dicing from the inclined direction as described above, the processing operation of polishing the cross section to form the inclined surfaces 7 and 8 can be performed more easily using a general-purpose technique.

(Embodiment 2)
In the present embodiment, antireflection films 13 and 23 for preventing light reflection are formed on the surfaces of the fixing grooves 11 and 21 of the first support 1 and the second support 2 as shown in FIG. There is a feature in the point. However, since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  As described in the first embodiment, the scattering of light at the interface can be suppressed by narrowing the width of the adhesive layer 9, but the scattered light cannot be completely eliminated. When light scattering occurs at the interface, the scattered light propagating in a direction different from the optical path of the reflected light is reflected by the surfaces of the fixed grooves 11 and 21, as indicated by broken line arrows C in FIG. There is a risk that crosstalk will occur when the light-receiving unit 51 corresponding to the above is reached.

  Therefore, in the present embodiment, the antireflection films 13 and 23 are formed on the surfaces of the fixing grooves 11 and 21 as described above, so that the scattered light reaches the light receiving unit 51 corresponding to the adjacent optical fibers 3 and 4. This suppresses crosstalk and reduces crosstalk.

(Embodiment 3)
In the present embodiment, as shown in FIG. 6, a light shielding film 14 (24) is provided at a portion excluding the optical path of the reflected light between the light receiving portion 51 of the light detecting element 5 and the optical fibers 3 and 4 on the incident side and the outgoing side. It is characterized in that it is formed. However, since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The light shielding film 14 (24) is formed by depositing a light absorbing material on the surface (bonding surface) of the covers 12, 22 facing the V-groove substrates 10, 20. The first support 1 and the second support 2 overlap with the interface between the end face of the core 30 (40) of the optical fiber 3 (4) and the adhesive layer 9 when viewed from the thickness direction (vertical direction in FIG. 6). At the position, a window hole 15 (25) in which the light shielding film 14 (24) is not formed is opened.

  Thus, according to the present embodiment, the reflected light reflected at the interface passes through the window hole 15 (25) opened in the light shielding film 14 (24) and is received by the corresponding light receiving unit 51. The generated scattered light is shielded by the light shielding film 14 (24) and does not reach the light receiving portion 51 corresponding to the adjacent optical fiber 3 (4), so that crosstalk can be suppressed and detection accuracy can be improved. Note that crosstalk can be further suppressed (reduced) by combining the configuration of the present embodiment and the configuration of the second embodiment.

(Embodiment 4)
In the present embodiment, as shown in FIG. 7, in the optical fiber 4 on the emission side, on the outer peripheral surface (the lower outer peripheral surface in FIG. 7) on the side facing the light receiving portion 51 of the photodetecting element 5 with the core 40 interposed therebetween. It is characterized in that the reflective film 26 is formed. However, since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The reflective film 26 is formed by depositing gold, silver, or a metal such as a gold alloy or a silver alloy on the outer peripheral surface of the clad 41 of the optical fiber 4 by a known method such as vapor deposition, sputtering, or plating.

  Thus, according to the present embodiment, a part of the scattered light generated at the interface is reflected by the reflection film 26 as shown by the broken line arrow in FIG. 7 and passes through the same optical path as the reflected light to the corresponding light receiving unit 51. Therefore, the detection efficiency can be further improved by increasing the amount of light received by the light receiving unit 51. Moreover, since the reflective film 26 is formed only on the outer peripheral surface on the side facing the light receiving part 51 with the core 40 in between, the scattered light reflected by the reflective film 26 is applied to the light receiving part 51 corresponding to the adjacent optical fiber 4. Since it does not reach, crosstalk can be suppressed and detection accuracy can be improved. Note that the configuration of the present embodiment may be combined with at least one of the configurations of the second or third embodiment. In the present embodiment, the reflection film 26 is formed on the optical fiber 4 on the emission side. However, the relative positional relationship between the inclined surface 7 of the first support 1 and the inclined surface 8 of the second support 2 (up and down) When the relationship is reversed, a reflective film may be formed on the optical fiber 3 on the incident side.

1 shows Embodiment 1 of the present invention, where (a) is a front view, (b) is a cross-sectional view taken along the line AA ′ of FIG. (A), and (c) is BB ′ of FIG. FIG. It is sectional drawing same as the above. (A)-(c) is sectional drawing for demonstrating a manufacturing process same as the above. (A)-(d) is sectional drawing for demonstrating another manufacturing process same as the above. It is sectional drawing which shows Embodiment 2 of this invention. It is sectional drawing which shows Embodiment 3 of this invention. It is sectional drawing which shows Embodiment 4 of this invention. A prior art example is shown, (a) is a side cross-sectional view, and (b) is a cross-sectional view taken along the line A-A 'in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st support body 2 2nd support body 3 Incident side optical fiber 4 Outgoing side optical fiber 5 Photodetection element 7 Inclined surface 8 Inclined surface 9 Adhesive layer 51 Light-receiving part

Claims (10)

A hot-wire detection device that detects whether an optical fiber is in a hot-wire state,
A first support that supports the incident-side optical fiber, a second support that supports the output-side optical fiber, and a light detection element that detects light;
One end surface of the first support and the incident side optical fiber is an inclined surface in which the normal direction of the end surface and the axial direction of the incident side optical fiber are acute angles,
One end face of the second support and the output-side optical fiber is an inclined surface in which the normal direction of the end face and the axial direction of the output-side optical fiber are acute angles,
The first support body and the second support body are bonded by a translucent adhesive in such a manner that the one end faces of the optical fibers on both the incident side and the output side face each other substantially in parallel.
An optical fiber hot-line detecting device, wherein the light detecting element is disposed on an optical path of reflected light reflected at an interface between the one end face of the incident side and the outgoing side optical fiber and the adhesive layer.   2. The optical fiber hot-wire detection device according to claim 1, wherein an angle formed between the normal direction of the inclined surface and the axial direction of the optical fiber is approximately 45 degrees.   By dividing one optical fiber and one support that supports the one optical fiber, a first support and a second support, an incident-side optical fiber, and an output-side optical fiber are formed. 3. The optical fiber hot-wire detection device according to claim 1, wherein an angle formed by the normal direction and the axial direction of the optical fiber is equal to the angle of the inclined surface.   The optical fiber hot-wire detection device according to claim 3, wherein the cross section is polished.   A first support is formed by dividing one optical fiber and one support supporting the one optical fiber in a direction substantially perpendicular to the axial direction of the optical fiber and polishing the cross section to form the inclined surface. 3. The optical fiber hot-wire detection device according to claim 1, wherein the body, the second support, the incident-side optical fiber, and the output-side optical fiber are formed.   6. The optical fiber active device according to claim 1, wherein the refractive index of the adhesive forming the adhesive layer is lower than the refractive indexes of the cores of the optical fibers on the incident side and the outgoing side. Line detector.   The first support body and the second support body have a plurality of fixed grooves into which a plurality of optical fibers are fitted so as to align their axial directions. An optical fiber hot-wire detection device as described.   8. The photodetecting element is disposed at a position facing the fixed groove with an optical fiber interposed therebetween, and an antireflection film for preventing light reflection is formed on a surface of the fixed groove. Optical fiber hot-wire detection device.   The light according to any one of claims 1 to 8, wherein a light shielding film is formed in a portion excluding the optical path of the reflected light between the light detection element and the optical fiber on the incident side and the emission side. Fiber hot-line detector.   10. The light according to claim 1, wherein a reflection film is formed on the outer peripheral surface of the incident-side or emission-side optical fiber that faces the photodetecting element with the core interposed therebetween. Fiber hot-line detector.

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