JP2016206285A - Optical fiber side inputting/outputting device and optical fiber side inputting/outputting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber side inputting/outputting device and an optical fiber side inputting/outputting method capable of efficiently receiving an outputting a light beam and allowing an input light beam to enter an object at high coupling efficiency in an optical system which inputs and outputs a light beam from the side of a bent fiber.SOLUTION: Using an optical system 13 with a lens as a fiber probe, a multi mode large core fiber 12 is used for receiving a beam of light, and a single mode fiber 11 is used for emitting light. With this, a low-intensity light from a light source is received via the multi mode large core fiber 12; and the single mode fiber 11 allows a beam of light to enter a bent fiber 1 at a high coupling efficiency.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a technique for inputting and outputting light from the side of an optical fiber.

  Optical fiber side input / output technology enables the transmission and reception of optical signals between two optical fibers by a structure in which another optical fiber is abutted against the side of a bent portion of an optical fiber bent at an angle. Technology. Hereinafter, in this specification, the optical fiber that is bent is referred to as a bent optical fiber, and the optical fiber that is abutted against the side surface of the bent optical fiber is referred to as a probe fiber. Application of the optical fiber side input / output technology to a leakage light monitor, test light incidence for controlling a core wire, or a short interruption switch for changing the route of an optical line is being studied.

  FIG. 1 is a conceptual diagram for explaining an optical fiber side input / output device. A coated optical fiber (main optical fiber 1) or the like is pressed against the cylindrical portion 2 which is a cylindrical rigid body, and the bent portion 3 is formed. The refractive index matching agent 4 which is a transparent gel-like member is formed so as to have a certain thickness so as to cover the bent portion 3 which is in close contact with the cylindrical portion 2. The end face of the probe fiber 5 is abutted against the bent portion 3 so as to be inserted into the refractive index matching agent 4, thereby forming a lateral input / output optical system. A lens (not shown) may be formed on the end face of the probe fiber 5.

  The radius of curvature of the portion of the bent portion 3 that contacts the cylindrical portion 2 is, for example, 1.7 mm, and the angle formed by the arc portion is about 30 degrees. By forming the bent portion 3, the total reflection condition of the optical fiber is relaxed, and light can be input / output from the side of the optical fiber. Light from the bending portion 3 passes through the refractive index matching agent 4 and enters the probe fiber 5 and is output to the outside. The traveling direction of the light is reversible, and the light from the probe fiber 5 can be input to the main optical fiber 1 through the same path.

  For example, a short break switch has been proposed as a usage application of this technology. The short interruption switch can be applied to an optical communication line switching device in an access network, for example. The optical communication line switching device is a device for bypassing an optical signal to a detour line by optical fiber side input / output technology. If this type of device is used, communication can be maintained on the detour line even if the working optical fiber is cut off due to troubled relocation work, etc., so the switching work of the optical communication line can be performed in-service.

  FIG. 2 is a diagram illustrating the optical communication line switching device disclosed in Patent Document 1. In FIG. An optical communication line switching device is formed by providing a pair of side light input / output mechanisms (51, 52) in the middle of the working optical line optical fiber 100 to bypass the light. Further, as shown in FIG. 3, a pair of optical communication line switching devices (53, 54) are disposed on the working optical line optical fiber 100 so that the new optical line optical fiber 200 is parallel to the working optical line optical fiber 100. By connecting, it is possible to form an optical system that can switch the optical path from the working optical line optical fiber 100 to the new optical line optical fiber 200 with a short interruption.

JP 2012-252099 A

  In the optical fiber side input / output device as shown in FIG. 1, it is desirable that the coupling efficiency is high. Even if the coupling efficiency does not change, the light incident on the bending portion 3 can be increased several times by increasing the light source intensity. On the other hand, in the case of receiving light emitted from the bent portion 3, it is the coupling between the single mode fibers, and it is not easy to increase the coupling efficiency, and it is greatly reduced even by a positional deviation of only about 10 μm. When the coupling efficiency is reduced due to the displacement, the minimum light receiving sensitivity of the amplification repeater may not be reached and it may become impossible to receive and transmit as a signal. As described above, the optical fiber side input / output device configured as shown in FIG. 1 has a problem that it is difficult to reliably capture the leaked light from the bent portion.

  Here, if a multimode fiber having a large fiber core (for example, a core diameter of 50 μm) is used as the probe fiber as shown in FIG. 4, the coupling efficiency when receiving light emitted from the bending portion 3 is improved. However, in the case where the probe fiber 5a in the reverse direction is incident on the bending portion 3, the light source size is 50 μm, and the size of the image projected onto the bending portion 3 is enlarged accordingly. The efficiency is reduced to several tenths. Such a decrease in coupling efficiency is difficult to compensate for by increasing the light source intensity. That is, the optical fiber side input / output device configured as shown in FIG. 4 has a problem that it is difficult to input light from the probe fiber to the main optical fiber.

  In order to solve the problems of the configuration shown in FIGS. 1 and 4, an optical fiber side input / output device that separates the paths of input light and leaked light by an optical system such as a beam splitter has been proposed. FIG. 5 is a diagram illustrating an optical fiber side input / output device that separates the paths of input light and leaked light. The optical fiber side input / output device of FIG. 5 includes a beam splitter 6 and a multimode fiber 9 that receives leaked light in the configuration of the optical fiber side input / output device of FIG.

Specifically, the optical fiber side input / output device of FIG. 5 is an optical fiber side input / output device that inputs / outputs light to / from the main optical fiber 1 formed with the bent portion 3. ,
A probe fiber 5 having a cross section abutted against the bending portion 3 and capable of making incident light incident on the bending portion 3 through the cross section;
A beam splitter 6 that is provided between the bending portion 3 and the cross section and changes a path of leakage light leaking from the bending portion 3 in a direction different from the cross section;
A multimode fiber 9 for capturing the leaked light whose path has been changed;
It is characterized by comprising.

  The optical fiber side input / output device of FIG. 5 uses a multimode fiber 9 having a large core diameter in order to reliably capture the leaked light λ1 from the bent portion 3 of the main optical fiber 1 (single mode fiber). That is, the optical fiber side input / output device of FIG. 5 can solve the problems of the optical fiber side input / output device of FIG. On the other hand, in the optical fiber side input / output device of FIG. 5, the incident light λ2 incident on the main optical fiber 1 has the same configuration as that of the optical fiber side input / output device of FIG. Equivalent to fiber side input / output device. That is, the optical fiber side input / output device of FIG. 5 can solve the problems of the optical fiber side input / output device of FIG. As described above, the optical fiber side input / output device of FIG. 5 can solve the problems of the configurations of FIG. 1 and FIG.

  However, the optical fiber side input / output device shown in FIG. 5 has an optical path length of incident light from the end of the probe fiber to the bent portion and the leaked light from the bent portion to the end of the multimode fiber by the amount of insertion of the beam splitter 6. The optical path length becomes longer. Incident light only needs to increase its light intensity, but the leaked light is weak at the time of leakage, and the light intensity is further reduced before reaching the end of the multimode fiber due to scattering in the optical path, and sufficient optical coupling It is difficult to obtain efficiency. This decrease in coupling efficiency is difficult to compensate for by increasing the light source intensity. That is, the optical fiber side input / output device configured as shown in FIG. 5 can reliably capture the leaked light from the bent portion, but the optical path length is long and the light intensity of the leaked light is reduced, thereby improving the coupling efficiency. There was a problem of difficulty.

  Accordingly, an object of the present invention is to provide an optical fiber side input / output device and an optical fiber side input / output method capable of improving the coupling efficiency with the main optical fiber in both the incident direction and the outgoing direction in order to solve the above-described problems. And

  In the optical fiber side input / output device according to the present invention, a condensing lens is arranged between the main optical fiber and the beam splitter to improve the optical coupling efficiency.

Specifically, an optical fiber side input / output device according to the present invention is an optical fiber side input / output device that inputs / outputs light to / from a main optical fiber formed with a bent portion. And
An optical fiber for incidence that has a cross-section close to the bent portion and is capable of entering incident light into the bent portion through the cross-section;
A condensing lens that is provided between the bent portion and the cross section, condenses leakage light leaking from the bent portion, and condenses incident light from the cross section on the bent portion;
An optical system that is provided between the condenser lens and the cross section and separates a path of leakage light collected by the condenser lens and a path of incident light from the incident optical fiber;
A capturing unit that captures leaked light from the optical system;
It is characterized by providing.

Further, the optical fiber side input / output method according to the present invention is an optical fiber side input / output method for inputting / outputting light to / from a main optical fiber formed with a bent portion through the bent portion,
A cross section of the incident optical fiber is brought close to the bent portion, and incident light can be incident on the bent portion through the cross section.
A condensing lens is provided between the bent portion and the cross section, the leakage light leaking from the bent portion is condensed, and the incident light from the cross section is condensed on the bent portion,
An optical system is provided between the condensing lens and the cross section, and a path of leakage light collected by the condensing lens and a path of incident light from the incident optical fiber are separated,
Leakage light from the optical system is captured by a capturing unit.

  In the present invention, the leakage light from the bent portion is collected by the lens portion, thereby preventing scattering, preventing the light intensity of the leakage light from being lowered, and improving the coupling efficiency of the outgoing light from the main optical fiber. Further, since the lens unit can collect the incident light on the bent part, the coupling efficiency of the incident light to the main optical fiber can be increased as compared with the configuration described in FIGS. Therefore, the present invention can provide an optical fiber side input / output device and an optical fiber side input / output method capable of improving the coupling efficiency with the main optical fiber in both the incident direction and the outgoing direction.

  Here, it is preferable that the capturing unit is a multimode fiber that propagates in a multimode at the wavelength of the leaked light.

  The main optical fiber may be a tape fiber. When the main optical fiber is a tape fiber, the configuration is as follows.

An optical fiber side input / output device for a tape fiber is a light that inputs / outputs light to / from each of the fibers of the tape fiber in which bent portions are formed in the parallel direction of a plurality of fibers. A fiber side input / output device,
An incident optical fiber array in which each cross-section is adjacent to each of the bent portions, and incident light can be incident on the bent portion via the cross-section,
A condensing lens array that is provided between the bent portion and the cross section, condenses leaked light leaking from the bent portion, and condenses incident light from the cross section on the bent portion;
An optical system that is provided between the condenser lens array and the cross section and separates the path of each leaked light collected by the condenser lens array and the path of each incident light from the incident optical fiber array; ,
A capturing unit that captures each leakage light from the optical system;
It is characterized by providing.

Another form of the optical fiber side input / output device for the tape fiber is that the light is transmitted to each of the fibers of the tape fiber in which the bent portions are respectively formed in the parallel direction of the plurality of fibers through the bent portions. An optical fiber side input / output device for input / output,
An incident optical fiber array in which each cross-section is adjacent to each of the bent portions, and incident light can be incident on the bent portion via the cross-section,
One condensing lens that is provided between the bent portion and the cross section, condenses leaked light leaking from the bent portion, and condenses incident light from the cross section on the bent portion, respectively.
An optical system provided between the condensing lens and the cross-section, and separating a path of each leaked light collected by the condensing lens and a path of each incident light from the incident optical fiber array;
A capturing unit that captures each leakage light from the optical system;
It is characterized by providing.

  The present invention can provide an optical fiber side input / output device and an optical fiber side input / output method capable of improving the coupling efficiency with the main optical fiber in both the incident direction and the outgoing direction.

It is a conceptual diagram explaining an optical fiber side input / output device. This is a coupling between a main optical fiber (single mode fiber) core and a single mode fiber core of a probe fiber, and leakage light from the main optical fiber is acquired by the single mode fiber core. If the amount of leaked light from the main optical fiber is low, it cannot reach the minimum light receiving sensitivity of the subsequent amplification repeater and cannot be transmitted. In addition, the region where the probe fiber can receive light is narrow, and it takes time to adjust the optical axis. It is a figure which shows the optical communication line switching apparatus shown by patent document 1. FIG. It is a figure which shows the optical communication system shown by patent document 1. FIG. It is a conceptual diagram explaining an optical fiber side input / output device. The coupling efficiency from the main optical fiber (for example, a single mode fiber having a core φ10 μm) to a probe fiber (for example, a core φ50 μm multimode fiber) is high. However, little light is coupled from the probe fiber to the main optical fiber. It is a conceptual diagram explaining an optical fiber side input / output device. It is a conceptual diagram explaining the optical fiber side input / output apparatus which concerns on this invention. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part. Since the leakage light λ1 emitted from the main optical fiber (single mode fiber) core can be acquired by the multimode fiber portion having a large core diameter, the amount of received light can be increased. For λ2 incident on the main optical fiber, the single mode fiber cores are coupled to each other, and the coupling efficiency is the same as that of the configuration of FIG. It is a conceptual diagram explaining the optical fiber side input / output apparatus which concerns on this invention. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part. It is a conceptual diagram explaining the optical fiber side input / output apparatus which concerns on this invention. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are embodiments of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
FIG. 6 is a conceptual diagram illustrating the optical fiber side input / output device 301 of the present embodiment. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part.

The optical fiber side input / output device 301 is an optical fiber side input / output device that inputs / outputs light to / from the main optical fiber 1 formed with the bent portion 3 through the bent portion 3.
An incident optical fiber 11 having a cross section close to the bending portion 3 and capable of making incident light incident on the bending portion 3 through the cross section;
A condensing lens 14 provided between the bending portion 3 and the cross section, for condensing the leakage light λ1 leaking from the bending portion 3, and condensing the incident light λ2 from the cross section on the bending portion;
An optical system 13 provided between the condensing lens 14 and the cross section and separating the path of the leaked light λ1 collected by the condensing lens 14 and the path of the incident light λ2 from the incident optical fiber 11;
A capturing unit that captures the leaked light λ1 from the optical system 13, and
Is provided.

  The capturing unit may be a photodiode that receives leakage light. In the present embodiment, the capturing unit is a multimode fiber 12 that propagates in a multimode at the wavelength of leakage light.

In order to achieve the above object, the optical fiber side input / output device 301 takes the following measures.
Leakage light having a wavelength λ1 radiated from the bending portion 3 obtained by bending the main optical fiber 1 (single-core fiber) by the bending-applying cylindrical portion 2 is condensed by the condensing lens 14, and is contacted with the condensing lens 14. The wavelength λ1 is reflected by the optical system 13 (for example, a wavelength beam splitter) that reflects λ1, condensed on the end surface of the large-core multimode fiber 12, and transmitted to the photodetector via the large-core fiber. The light detection efficiency increases. On the other hand, incident light having a wavelength λ 2 transmitted from the light source via the incident optical fiber 11 (for example, a single mode fiber) is incident on the optical system 13. Since the optical system 13 transmits the wavelength, the incident light enters the condenser lens 14 via the optical system 13 and is condensed by the condenser lens 14 onto the bent portion 3 of the main optical fiber.

  Furthermore, this embodiment will be described. The single mode fiber (main optical fiber 1) on the actual line is bent by the bending applying cylindrical portion 2. An optical system 13 connected to a condensing lens 14 having a diameter similar to the diameter of the main optical fiber 1 is installed at an appropriate position with respect to the leaked light λ1 diffused and emitted from this bending.

  Leakage light λ1 emitted from the main optical fiber 1 (single mode fiber) core enters the optical system 13 via the condenser lens 14. After that, the light is reflected by the optical system 13, collected on the end face of the multi-mode fiber 12 of the large core fiber, and reaches the light receiver (not shown) via the multi-mode fiber 12. Therefore, the optical fiber side input / output device 301 has higher light receiving efficiency than the optical fiber side input / output device described in FIG. 1, and sufficient light reception equivalent to the optical fiber side input / output device described in FIG. Strength can be obtained.

  On the other hand, incident light having a wavelength λ2 emitted from a light source (not shown) is transmitted via an incident optical fiber 11 (single mode fiber), enters the condenser lens 14 via the optical system 13, and enters the condenser lens. 14 enters the bent portion 3 of the main optical fiber 1. The optical fiber side input / output device 301 is equivalent to the optical fiber side input / output device described in FIG. 1 in terms of the coupling efficiency of incident light from the incident optical fiber 11 to the main optical fiber 1, and the light described in FIG. It does not drop like a fiber side input / output device.

  The optical system 13 is formed with a dielectric multilayer film that transmits the wavelength λ2 and reflects the wavelength λ1, but it may transmit the wavelength λ1 and reflect the wavelength λ2. In that case, the positions of the incident optical fiber 11 and the multimode fiber 12 may be reversed from the positions shown in FIG.

  Although a light source is not shown, in the present embodiment, a semiconductor laser (DFB-LD or the like) used for optical communication is assumed. Further, although not shown in the figure, an avalanche photodiode (APD) or the like is assumed. The diameter of the single mode fiber core that is the incident optical fiber 11 is approximately 10 μm, and the core diameter of the multimode fiber 12 is assumed to be 50 μm. Since the diameter of a general APD is 50 μm, optical coupling with a multimode fiber having this diameter is easy.

(Embodiment 2)
FIG. 7 is a conceptual diagram illustrating the optical fiber side input / output device 302 of the present embodiment. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part.

The optical fiber side input / output device 302 is an optical fiber that inputs / outputs light to / from the fiber of the tape fiber 17 in which the bent portions 3 are formed in the parallel direction of a plurality of fibers. A side input / output device,
An incident optical fiber array 21 in which the respective cross sections are close to the respective bent portions 3 and incident light can be incident on the bent portions 3 via the cross sections;
A condensing lens array 24 provided between the bending portion 3 and the cross section for condensing leakage light leaking from the bending portion 3 and condensing incident light from the cross section on the bending portion 3;
An optical system 23 that is provided between the condenser lens array 24 and the cross section and separates the path of each leaked light collected by the condenser lens array 24 and the path of each incident light from the incident optical fiber array 21. When,
A capturing unit that captures each leakage light from the optical system 23;
Is provided.

  The capturing unit may be a photodiode array that receives leakage light. In the present embodiment, the capturing unit is a capturing optical fiber array 22 in which a plurality of multimode fibers that propagate in a multimode at the wavelength of leakage light are arranged in parallel.

In order to achieve the above object, the optical fiber side input / output device 302 takes the following measures.
The leaked light having the wavelength λ1 emitted from the bent portion 3 obtained by bending the tape fiber 17 by the bending-applying cylindrical portion 2 is collected by the condenser lens array 24, is brought into contact with the condenser lens array 24, and the wavelength λ1 is reflected. Reflected by the optical system 23 (for example, a wavelength beam splitter), collected on the end face of the capturing optical fiber array 22 (multimode large core fiber array), and transmitted to the photodetector array via the large core fiber array Therefore, the detection efficiency of the light with the wavelength λ1 is increased. On the other hand, incident light having a wavelength λ 2 transmitted from the light source array via the incident optical fiber array 21 (for example, a single mode fiber array) is incident on the optical system 23. Since the optical system 23 transmits the wavelength, the incident light is incident on the condensing lens array 24 via the optical system 23, and is condensed on the bent portion 3 of the tape fiber 17 by the condensing lens array 24.

  Furthermore, this embodiment will be described. Bending is applied to the tape fiber 17 on the actual line (a plurality of single-mode fibers arranged in a tape shape) by the bend applying cylindrical portion 2. An optical system 23 connected to a condensing lens array 24 having a diameter similar to the diameter of each fiber of the tape fiber 17 is installed at an appropriate position with respect to the leakage light λ1 diffused and emitted from this bending.

  Leaked light λ1 emitted from each core of the tape fiber 17 enters the optical system 23 via the condenser lens array 24. Thereafter, the light is reflected by the optical system 23, collected on the end face of the multimode large-core fiber array (capturing optical fiber array 22), and reaches the photodetector array (not shown) via the capturing optical fiber array 22. To do. Therefore, the optical fiber side input / output device 302 has higher light receiving efficiency than the optical fiber side input / output device described with reference to FIG. 1, and sufficient light reception equivalent to the optical fiber side input / output device described with reference to FIG. Strength can be obtained.

  On the other hand, incident light having a wavelength λ 2 emitted from a light source array (not shown) is transmitted via the incident optical fiber array 21, enters the condensing lens array 24 via the optical system 23, and the condensing lens array 24. Is incident on the bending portion 3 of the tape fiber 17. The optical fiber side input / output device 302 is equivalent to the optical fiber side input / output device described in FIG. 1 with respect to the coupling efficiency of incident light from the incident optical fiber array 21 to the tape fiber 17, and is described in FIG. 4. It does not drop like an optical fiber side input / output device.

  The optical system 23 is formed with a dielectric multilayer film that transmits the wavelength λ2 and reflects the wavelength λ1, but it may transmit the wavelength λ1 and reflect the wavelength λ2. In this case, the positions of the incident optical fiber array 21 and the capturing optical fiber array 22 may be reversed from the positions shown in FIG.

  Although a light source array and a light receiver array are not shown, this assumes a semiconductor laser (DFB-LD or the like) and an avalanche photodiode (APD) or the like used for optical communication as in the first embodiment.

(Embodiment 3)
FIG. 8 is a conceptual diagram illustrating the optical fiber side input / output device 303 of the present embodiment. (A) is the bottom view seen from the multimode fiber direction. (B) is the side view seen from the central-axis direction of the bending provision cylindrical part.

The optical fiber side input / output device 303 is an optical fiber that inputs / outputs light to / from the fiber of the tape fiber 17 in which the bent portions 3 are formed in the parallel direction of a plurality of fibers. A side input / output device,
An incident optical fiber array 21 in which the respective cross sections are close to the respective bent portions 3 and incident light can be incident on the bent portions 3 via the cross sections;
A condensing lens 34 provided between the bending portion 3 and the cross section, condensing leakage light leaking from the bending portion 3, and condensing incident light from the cross section on the bending portion 3, respectively;
An optical system 23 provided between the condensing lens 34 and the cross section, for separating the path of each leaked light collected by the condensing lens 34 and the path of each incident light from the incident optical fiber array 21;
A capturing unit that captures each leakage light from the optical system 23;
Is provided.

The capturing unit may be a photodiode array that receives leakage light. In the present embodiment, the capturing unit is a capturing optical fiber array 22 in which a plurality of multimode fibers that propagate in a multimode at the wavelength of leakage light are arranged in parallel.
The optical fiber side input / output device 303 is obtained by replacing the condensing lens array 24 of the optical fiber side input / output device 302 of FIG. By using the common condensing lens, the alignment work required for the condensing lens array 24 can be omitted.

The operation and effect of the optical fiber side input / output device 303 are the same as those of the optical fiber side input / output device 302 of FIG.
In other words, the optical fiber side input / output device 303 has higher light receiving efficiency than the optical fiber side input / output device described with reference to FIG. 1, and is equivalent to the optical fiber side input / output device described with reference to FIG. The received light intensity can be obtained. The optical fiber side input / output device 303 is equivalent to the optical fiber side light input / output device described in FIG. 1 with respect to the coupling efficiency of the incident light from the incident optical fiber array 21 to the fiber tape 17 in FIG. It does not drop like the optical fiber side light input / output device described.

  Although the light source array and the light receiver array are not shown in the figure, this assumes a semiconductor laser (DFB-LD or the like) and an avalanche photodiode (APD) or the like used for optical communication as in the first embodiment.

(Other embodiments)
The present invention is not limited to the above-described embodiments. For example, an ordinary lens can be used instead of a single gradient index lens. Further, the refractive index matching agent is generally gel-like, but this can provide the same effect even when a solid transparent member such as acrylic or glass is used. In addition, the material and shape of the probe fiber and fiber holder can be variously modified without departing from the gist of the present invention.

  In short, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment. Furthermore, you may combine suitably the component covering different embodiment.

(Effect of the invention)
According to the present invention, the following operational effects are exhibited.
(1) The light emitted from the bending fiber is condensed on the end face of the large core fiber by the lens-equipped optical system 23, so that the light can be efficiently received with a large aperture. Therefore, even when the light emitted from the bending fiber is weak or deviated from the optimum position due to the axis deviation, it can be received, amplified and transmitted.
(2) Light transmitted from the light source via the single mode fiber enters the optical system with lens 23 and enters the bent portion of the bent fiber, so that it can be efficiently condensed and optically coupled to the bent fiber. .
(3) The light emitted from the bending tape fiber can be efficiently received with a large aperture by condensing the light emitted from the bending tape fiber onto the end face of the large core fiber array by the optical system 23 with a lens array. For this reason, even when the light emitted from the bent tape fiber is weak, or when the light deviates from the optimum position due to the axis deviation, the light can be received, amplified and transmitted.
(4) Light transmitted from the light source array via the single mode fiber array enters the optical system with lens array 23 and enters the bent portion of the bent tape fiber to efficiently collect the light and optically couple it to the bent fiber. Can be made.
(5) By condensing the light emitted from the bent tape fiber on the end face of the large core fiber array by the optical system with lens 23, it becomes possible to receive light efficiently with a large aperture. For this reason, even when the light emitted from the bent tape fiber is weak, or when the light deviates from the optimum position due to the axis deviation, the light can be received, amplified and transmitted.
(6) Light transmitted from the light source array via the single mode fiber array enters the optical system with lens 23 and enters the bent portion of the bent tape fiber, thereby efficiently condensing and optically coupling to the bent fiber. be able to.

1: Main optical fiber 2: Bend imparting cylindrical portion 3: Bending portion 4: Refractive index matching agent 5, 5a: Probe fiber 9: Multimode fiber 11: Optical fiber for incidence 12: Multimode fiber 13: Optical system 14: Collection Optical lens 17: Tape fiber 21: Incident optical fiber array 22: Capture optical fiber array 23: Optical system 24: Condensing lens array 34: Condensing lens 51, 52: Side light input / output mechanism 53, 54: Light Communication line switching device 100: Working optical line optical fiber 200: New optical line optical fibers 301, 302, 303: Optical fiber side input / output device

Claims (8)

An optical fiber side input / output device that inputs and outputs light through the bent portion with respect to a main optical fiber formed with a bent portion,
An optical fiber for incidence that has a cross-section close to the bent portion and is capable of entering incident light into the bent portion through the cross-section;
A condensing lens that is provided between the bent portion and the cross section, condenses leakage light leaking from the bent portion, and condenses incident light from the cross section on the bent portion;
An optical system that is provided between the condenser lens and the cross section and separates a path of leakage light collected by the condenser lens and a path of incident light from the incident optical fiber;
A capturing unit that captures leaked light from the optical system;
An optical fiber side light input / output device comprising:   The optical fiber side light input / output device according to claim 1, wherein the capturing unit is a multimode fiber that propagates in a multimode at a wavelength of the leaked light. An optical fiber side input / output device that inputs / outputs light through each of the bent portions of the fibers of the tape fiber in which bent portions are formed in the parallel direction of a plurality of fibers,
An incident optical fiber array in which each cross-section is adjacent to each of the bent portions, and incident light can be incident on the bent portion via the cross-section,
A condensing lens array that is provided between the bent portion and the cross section, condenses leaked light leaking from the bent portion, and condenses incident light from the cross section on the bent portion;
An optical system that is provided between the condenser lens array and the cross section and separates the path of each leaked light collected by the condenser lens array and the path of each incident light from the incident optical fiber array; ,
A capturing unit that captures each leakage light from the optical system;
An optical fiber side light input / output device comprising:   The optical fiber side light input / output device according to claim 3, wherein the capturing unit is a capturing optical fiber array in which a plurality of multimode fibers that propagate in multimode at the wavelength of the leaked light are arranged in parallel. An optical fiber side input / output device that inputs / outputs light through each of the bent portions of the fibers of the tape fiber in which bent portions are formed in the parallel direction of a plurality of fibers,
An incident optical fiber array in which each cross-section is adjacent to each of the bent portions, and incident light can be incident on the bent portion via the cross-section,
One condensing lens that is provided between the bent portion and the cross section, condenses leaked light leaking from the bent portion, and condenses incident light from the cross section on the bent portion, respectively.
An optical system provided between the condensing lens and the cross-section, and separating a path of each leaked light collected by the condensing lens and a path of each incident light from the incident optical fiber array;
A capturing unit that captures each leakage light from the optical system;
An optical fiber side light input / output device comprising:   6. The optical fiber side light input / output device according to claim 5, wherein the capturing unit is a capturing optical fiber array in which a plurality of multimode fibers that propagate in multimode at the wavelength of the leaked light are arranged in parallel. An optical fiber side input / output method for inputting / outputting light to / from a main optical fiber formed with a bent portion through the bent portion,
A cross section of the incident optical fiber is brought close to the bent portion, and incident light can be incident on the bent portion through the cross section.
A condensing lens is provided between the bent portion and the cross section, the leakage light leaking from the bent portion is condensed, and the incident light from the cross section is condensed on the bent portion,
An optical system is provided between the condensing lens and the cross section, and a path of leakage light collected by the condensing lens and a path of incident light from the incident optical fiber are separated,
An optical fiber side light input / output method characterized in that leakage light from the optical system is captured by a capturing unit.   The optical fiber side light input / output method according to claim 7, wherein the capturing unit is a multimode fiber that propagates in a multimode at a wavelength of the leaked light.

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