Fiber Optic Connection Status Determination System and Method

Abstract

An optical fiber connection status determination system determines the connection status of a first optical fiber and a second optical fiber in a connection section. The connection section is detachably connected to the output side of the first optical fiber that transmits test light input from a light source and outputs the test light, and the input side of the second optical fiber that receives and outputs the test light transmitted from and from the first optical fiber. The optical fiber connection status determination system includes: a measuring unit that measures the intensity of reflected light in the test light that is reflected and transmitted in the first optical fiber; and a determination unit that determines the connection status of the first optical fiber and the second optical fiber in the connection section based on the intensity measured by the measuring unit.

Description

Technical Field

[0001] This invention relates to a system and method for determining the connection status of optical fibers. Background Technology

[0002] As inventions for detecting fiber optic breaks, there are, for example, the inventions disclosed in Patent Documents 1-3. The invention disclosed in Patent Document 1 has a structure that detects fiber optic breaks through an electrical structure. The invention disclosed in Patent Document 2 receives light reflected from the front end of the fiber and detects an abnormality in the fiber based on the difference between this light and the light received when the fiber is not broken. The invention disclosed in Patent Document 3 uses a light-receiving sensor to receive light reflected back from the fiber and compares the received result with a reference value to detect an abnormality in the fiber.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-224898

[0006] Patent Document 2: Japanese Patent Application Publication No. 2016-071040

[0007] Patent Document 3: Japanese Patent Application Publication No. 2002-291764 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In devices that use lasers to treat patients, a laser device that outputs laser light is connected to a catheter inserted into the body for each procedure, and the laser light is output from the catheter for treatment. To allow for connection between the laser device and the catheter for each procedure, the laser device and catheter are configured to be detachable. If the fiber optic connection between the catheter and the laser device is incomplete when connecting the catheter to the laser device, for example, insufficient laser energy reaching the affected area may occur. Therefore, a technique for detecting the connection status of the fiber optic cable transmitting the laser is desired.

[0010] While Patent Document 1 discloses the detection of broken wires, it does not disclose the detection of poor connections. Similarly, while Patent Document 2 discloses the detection of optical fiber anomalies, it does not disclose the determination of poor connections; therefore, the invention in Patent Document 2 cannot detect poor connections. Furthermore, while Patent Document 3 discloses the detection of anomalies caused by breakage or dirt on the end face, it does not disclose the determination of poor connections; therefore, the invention in Patent Document 3 also cannot detect poor connections.

[0011] The present invention was made in view of the above, and provides a technique for determining the connection status of detachable optical fibers.

[0012] Solution for solving the problem

[0013] To address the aforementioned issues and achieve the objective, one aspect of the present invention provides an optical fiber connection status determination system that determines the connection status of a first optical fiber and a second optical fiber in a connection section. The connection section is detachably connected to the output side of the first optical fiber that transmits test light input from a light source, and the input side of the second optical fiber that receives and outputs test light transmitted from and from the first optical fiber. The optical fiber connection status determination system comprises: a measuring unit that measures the intensity of reflected light in the test light that is reflected and transmitted through the first optical fiber; and a determination unit that determines the connection status of the first optical fiber and the second optical fiber in the connection section based on the intensity measured by the measuring unit.

[0014] The fiber connection status determination system of one aspect of the present invention can also be configured such that the intensity of the reflected light measured by the measuring unit is different when the second fiber is broken compared to when the second fiber is disconnected from the connection part.

[0015] The fiber connection status determination system of one aspect of the present invention can also be configured such that the intensity of the reflected light measured by the measuring unit when the second fiber is broken is greater than the intensity of the reflected light measured by the measuring unit when the second fiber is disconnected from the connection unit.

[0016] The optical fiber connection status judgment system of one aspect of the present invention is characterized in that the first optical fiber and the second optical fiber are spatially coupled in the connection part, and the judgment part judges that the first optical fiber and the second optical fiber are poorly connected when the strength is less than a first threshold.

[0017] In one aspect of the optical fiber connection status determination system of the present invention, the structure can also be configured such that the second optical fiber is connected to an optical fiber coupler, and the test light emitted from a designated port among a plurality of ports from which the test light is emitted is reflected by a reflective part that reflects the test light.

[0018] The fiber optic connection status judgment system of one aspect of the present invention is characterized in that the measuring unit performs measurement whenever the operator performs the measurement operation, the judgment unit judges the connection status whenever the measuring unit performs the measurement, and judges that the second fiber optic cable has been broken when the judgment result of poor connection occurs continuously.

[0019] In one aspect of the optical fiber connection status determination system of the present invention, the structure can also be configured such that the intensity of the reflected light measured by the measuring unit when the second optical fiber is disconnected from the connection part is greater than the intensity of the reflected light measured by the measuring unit when the second optical fiber is broken.

[0020] The optical fiber connection status judgment system of one aspect of the present invention is characterized in that the first optical fiber and the second optical fiber are joined together in the connection part, and the judgment part judges that the first optical fiber and the second optical fiber are poorly connected when the intensity is above a second threshold and below a third threshold that is greater than the second threshold.

[0021] In one embodiment of the optical fiber connection status determination system of the present invention, the structure can also be configured such that the second optical fiber is connected to an optical fiber coupler.

[0022] The fiber connection status determination system of one aspect of the present invention is characterized in that, when the determination unit determines that the second fiber has been broken when the intensity is below a fourth threshold which is smaller than the second threshold.

[0023] The optical fiber connection status determination system of one aspect of the present invention is characterized in that the optical fiber connection status determination system includes a notification unit that notifies the connection status of the first optical fiber and the second optical fiber based on the determination result of the determination unit.

[0024] The fiber optic connection status determination system of one aspect of the present invention is characterized in that the laser used to burn the human body is combined with the test light and input into the first fiber optic cable, and when the determination unit determines that the second fiber optic cable has been broken, the output of the laser from the light source that outputs the laser is stopped.

[0025] One aspect of the present invention provides a method for determining the connection status of an optical fiber, wherein the connection is provided in a connector that can be detachably connected to the output side of the first optical fiber that transmits test light from a light source and outputs the test light, and the input side of the second optical fiber that receives the test light transmitted from and outputs the test light from the first optical fiber. The method is characterized by comprising: a measurement step of measuring the intensity of reflected light in the test light that is transmitted through the first optical fiber; and a determination step of determining the connection status of the first optical fiber and the second optical fiber based on the intensity measured in the measurement step.

[0026] Invention Effects

[0027] According to the present invention, it is possible to determine the connection status of detachable optical fibers. Attached Figure Description

[0028] Figure 1 This is a diagram showing the outline structure of the laser system according to the first embodiment.

[0029] Figure 2 This is a block diagram illustrating the structure of the first embodiment.

[0030] Figure 3 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0031] Figure 4 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0032] Figure 5 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0033] Figure 6 This is a flowchart illustrating the process of determining the connection status.

[0034] Figure 7 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0035] Figure 8 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0036] Figure 9 This is a schematic diagram illustrating an example of the connection status of the optical fiber in the connector.

[0037] Figure 10 This is a flowchart illustrating the process of determining the connection status.

[0038] Figure 11 This is a diagram showing the structure of a modified example of a conduit. Detailed Implementation

[0039] [First Implementation Method]

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments described below. Furthermore, in the accompanying drawings, the same or corresponding elements are appropriately labeled with the same reference numerals.

[0041] Figure 1 This is a schematic diagram showing the general structure of a laser system 1 according to a first embodiment of the present invention. Laser system 1 is a system for treating a patient by irradiating a patient with a laser. Laser system 1 includes: a laser device 10 that outputs a laser beam irradiated towards the patient; a connecting portion 20 that connects the laser device 10 to a conduit 30; and a conduit 30 that irradiates the patient's affected area with the laser.

[0042] In this embodiment, the laser device 10 includes a first laser diode 301, a second laser diode 302, and a photodiode 401. Additionally, the laser device 10 includes a multiplexer 501, a filter 601, an optical multiplexer / demultiplexer 701, and a first optical fiber 81a. Furthermore, the laser device 10 includes a control unit 100, a display unit 200, and an operable unit 801. The laser device 10 is an example of a connection status determination system.

[0043] The first laser diode 301 is a light source that outputs laser light to irradiate the affected area of ​​the patient. In the following description, the laser light output by the first laser diode 301 is referred to as the therapeutic light. In this embodiment, the wavelength of the therapeutic light is in the near-infrared band, for example, in the range of 600 nm to 1500 nm. The therapeutic light output from the first laser diode 301 is incident on the combiner 501 via an optical fiber. It should be noted that the light source outputting the therapeutic light is not limited to a laser diode; for example, it can also be a fiber laser.

[0044] The second laser diode 302 is a laser source used to determine the connection status of the two optical fibers connected by the connector 20 and the status of the optical fibers in the conduit 30. In the following description, the laser output by the second laser diode 302 will be referred to as the test light. In this embodiment, the wavelength of the test light is 635 nm, but it is not limited to 635 nm and may be other wavelengths. The test light output from the second laser diode 302 is incident on the combiner 501 via an optical fiber. It should be noted that the source of the output test light is not limited to a laser diode.

[0045] The combiner 501 has the function of combining multiple optical wavelengths of different wavelengths. The combiner 501 combines the treatment light and test light incident through the optical fiber, and outputs the treatment light and test light to the optical wave combiner splitter 701 through the optical fiber.

[0046] The optical wave combiner / splitter 701 outputs the treatment light and test light incident from the combiner 501 via optical fiber to the first optical fiber 81a. The treatment light and test light output from the optical wave combiner / splitter 701 are transmitted through the first optical fiber 81a. Additionally, the optical wave combiner / splitter 701 outputs the reflected laser light (i.e., the laser light from the test light output to the first optical fiber 81a) to the optical wave combiner / splitter 701 via optical fiber to the filter 601. It should be noted that the optical wave combiner / splitter 701 is preferably constructed from a 50:50 TAP coupler, an asymmetric TAP coupler, a WDM coupler, or a suitable combination thereof.

[0047] The first optical fiber 81a is an optical fiber for transmitting therapeutic and experimental light. The first optical fiber 81a is connected to the second optical fiber 31a of the conduit 30 (described later) via the connector 20. The first optical fiber 81a is, for example, a step-index or graded-index multimode optical fiber, but is not particularly limited thereto.

[0048] Filter 601 allows light of a predetermined wavelength in the incident reflected light to pass through. Thus, the laser light of the therapeutic wavelength in the reflected light incident on filter 601 is blocked by filter 601, while the laser light of the test wavelength passes through filter 601. The reflected light that has passed through filter 601 is then incident on photodiode 401.

[0049] The photodiode 401 is a photodetector that receives reflected light that has passed through the filter 601 and outputs a current signal corresponding to the intensity of the received reflected light. The current signal output from the photodiode 401 is input to the control unit 100.

[0050] The display unit 200 is a liquid crystal display (LCD) that displays various information about the laser device 10, such as the connection status of the optical fiber in the connection unit 20 and the status of the optical fiber in the conduit 30, in the form of text, symbols, and images. The operable unit 801 has buttons for operating the laser device 10. The operable unit 801 includes buttons for switching the output of the therapeutic light and stopping the output, and buttons for initiating the process of determining the connection status of the optical fiber connected in the connection unit 20. It should be noted that the operable unit 801 is not limited to buttons; any component that receives operation from the operator of the laser device 10 can be, for example, a touch panel.

[0051] The control unit 100 includes an arithmetic unit and a storage unit. The arithmetic unit controls the first laser diode 301, the second laser diode 302, and the display unit 200, and performs various arithmetic operations to realize the functions of the laser device 10. The control unit 100 may be composed of, for example, a CPU (Central Processing Unit), an FPGA (field-programmable gate array), or both a CPU and an FPGA.

[0052] The storage section includes, for example, a portion composed of ROM (Read Only Memory) and a portion composed of RAM (Random Access Memory). The ROM portion stores various programs, data, etc., used for computational processing by the arithmetic unit. The RAM is used for the working space of the arithmetic unit during computational processing and for storing the results of computational processing.

[0053] Figure 2This is a block diagram illustrating the structure of a function implemented by the arithmetic unit executing a program stored in the storage unit. The measuring unit 1001 acquires a current signal output from the photodiode 401. Based on the acquired current signal, the measuring unit 1001 measures the intensity of the reflected light incident on the photodiode 401.

[0054] The determination unit 1002 determines the connection status of the two optical fibers connected by the connecting unit 20 based on the intensity measured by the measuring unit 1001. In addition, the determination unit 1002 determines whether the optical fiber in the conduit 30 has been broken based on the intensity measured by the measuring unit 1001.

[0055] The notification unit 1003 controls the display unit 200 to display the judgment result of the judgment unit 1002. As a result, the user of the laser device 10 is notified of the connection status of the two optical fibers connected in the connection unit 20 and the status of the optical fibers in the conduit 30 that transmits therapeutic light.

[0056] The light source control unit 1004 controls the first laser diode 301 and the second laser diode 302 based on the operation performed by the operated unit 801 and the judgment result of the judgment unit 1002. If the light source control unit 1004 outputs a drive signal to the first laser diode 301, then therapeutic light is output from the first laser diode 301. If the light source control unit 1004 stops outputting the drive signal to the first laser diode 301, then the first laser diode 301 stops outputting therapeutic light. Similarly, if the light source control unit 1004 outputs a drive signal to the second laser diode 302, then test light is output from the second laser diode 302. If the light source control unit 1004 stops outputting the drive signal to the second laser diode 302, then the second laser diode 302 stops outputting test light.

[0057] return Figure 1 At least a portion of the catheter 30 is inserted into the patient's body, and the catheter 30 irradiates the treatment site of the patient with the therapeutic light incident from the first optical fiber 81a via the connector 20. The catheter 30 comprises: a catheter body 33, which is made of a flexible material such as resin; a second optical fiber 31a, at least a portion of which is inserted into the lumen of the catheter body 33; and a fiber Bragg grating (FBG) 32. The catheter 30 is a single-use component for each surgery, connected to the connector 20 before the start of the surgery and detached from the connector 20 after the surgery.

[0058] The second optical fiber 31a can be, for example, a step-index or graded-index multimode optical fiber, but is not particularly limited thereto. Furthermore, when the catheter 30 is a component inserted into a blood vessel, the second optical fiber 31a is preferably of a smaller diameter, for example, a core diameter of 120 μm or less and a cladding diameter of 140 μm or less. It should be noted that these core and cladding diameters are examples and are not particularly limited to these diameters. Regarding the second optical fiber 31a, the end in the connector 20 where the therapeutic light is incident is referred to as the incident end, and the end from which the therapeutic light exits is referred to as the exiting end.

[0059] FBG32 is disposed on the emitting end side of the second optical fiber 31a, for example, by fusion splicing to the emitting end of the second optical fiber 31a. FBG32 allows the treatment light that has entered from the incident end of the second optical fiber 31a and propagated in the second optical fiber 31a to pass through. Thus, the treatment light exits from the front end of the second optical fiber 31a (the front end side of the conduit 30). Additionally, FBG32 reflects the test light that has entered from the incident end of the second optical fiber 31a and propagated in the second optical fiber 31a. It should be noted that the reflectivity of the test light in FBG32 is preferably 90% or higher. Setting the reflectivity of the test light in FBG32 to 90% or higher allows for efficient reflection of the test light.

[0060] The connecting part 20 is a beam amplification connector that detachably connects the output side of the therapeutic light output in the first optical fiber 81a to the input side of the therapeutic light input in the second optical fiber 31a. In the connecting part 20, the first optical fiber 81a and the second optical fiber 31a are connected, for example, by spatial coupling.

[0061] Figure 3 This is a schematic diagram showing an example of the connection state of the optical fiber in the connector 20. The connector 20 includes a connector housing 22a and a connector housing 22b. The connector housing 22a and connector housing 22b are convex and concave respectively, and are interlocked. A ferrule 21a is fixed inside the connector housing 22a and fixes the end of the first optical fiber 81a. The first lens LE1 is a convex lens that parallelizes and focuses the laser light and is fixed inside the connector housing 22a. The first lens LE1 parallelizes the laser light emitted from the first optical fiber 81a. The laser light parallelized by the first lens LE1 is incident on the second lens LE2. In addition, the first lens LE1 focuses the laser light incident from the second lens LE2 side. The laser light focused by the first lens LE1 is incident on the first optical fiber 81a.

[0062] The ferrule 21b is fixed inside the connector housing 22b, and the end of the second optical fiber 31a is also fixed therein. The second lens LE2 is a convex lens for parallelizing and focusing the laser beam, and is fixed inside the connector housing 22b. The second lens LE2 focuses the laser beam parallelized by the first lens LE1. The laser beam focused by the second lens LE2 is incident on the second optical fiber 31a. Furthermore, the second lens LE2 parallelizes the laser beam incident from the second optical fiber 31a side. The laser beam parallelized by the second lens LE2 is incident on the first lens LE1. The treatment light exits from the front end of the conduit 30, therefore the transmittance of the treatment light in the connection portion 20 is preferably 75% or more, more preferably 80% or more. Additionally, the transmittance of the test light in the connection portion 20 is preferably 20% or more, more preferably 50% or more. If the transmittance of the test light in the connection portion 20 is such a transmittance, the connection status of the optical fiber in the connection portion 20 can be determined.

[0063] Figure 3 The diagram schematically illustrates the normal connection between the first optical fiber 81a and the second optical fiber 31a. Additionally, in... Figure 3 In the diagram, arrows indicate the test light and reflected light, while the illustration of the treatment light is omitted.

[0064] The test light TL1 is the test light output from the second laser diode 302. The test light TL1, emitted from the first optical fiber 81a, is incident on the second optical fiber 31a via the first lens LE1 and the second lens LE2. A portion of the test light TL1 undergoes Fresnel reflection upon exiting the first optical fiber 81a, becoming reflected light RL11, which propagates through the first optical fiber 81a. Additionally, a portion of the test light TL1 arriving at the second optical fiber 31a undergoes Fresnel reflection at its incident end, becoming reflected light RL21. Reflected light RL21, via the second lens LE2 and the first lens LE1, reaches the first optical fiber 81a and is incident within it. A portion of the reflected light RL21 undergoes Fresnel reflection upon incident on the first optical fiber 81a.

[0065] Furthermore, the test light TL1 transmitted in the second optical fiber 31a is reflected at FBG 32 to become reflected light RL31. Reflected light RL31 is transmitted in the second optical fiber 31a in the opposite direction to the test light TL1. Reflected light RL31 exits from the second optical fiber 31a. A portion of reflected light RL31 undergoes Fresnel reflection upon exiting the second optical fiber 31a. The reflected light RL31 exiting the second optical fiber 31a is incident on the first optical fiber 81a via the second lens LE2 and the first lens LE1. A portion of reflected light RL31 undergoes Fresnel reflection upon incident on the first optical fiber 81a. Reflected light RL11, reflected light RL21, and reflected light RL31 are transmitted to photodiode 401 via the first optical fiber 81a, optical multiplier / splitter 701, and filter 601. The intensity of the transmitted reflected light RL11, reflected light RL21, and reflected light RL31 is measured by the measuring unit 1001.

[0066] When the intensity of the test light TL1 emitted from the first optical fiber 81a is set to 1, and the transmittance of the group of the first lens LE1 and the second lens LE2 is set to β, in Figure 3 In the state shown, the intensity obtained by combining the intensities of reflected light RL11, RL21, and RL31 is given by equation (1) below. It should be noted that the reflectivity of FBG32 is set to 100%.

[0067] 0.04+0.96*β*(0.04*β*0.96+0.96*0.96*β*0.96) (1)

[0068] In this embodiment, the reflectivity of Fresnel reflection at the end face of the optical fiber is set to 4%, and the first term 0.04 in equation (1) corresponds to the reflected light RL11. In addition, "0.96*β" in "0.04+0.96*β*(0.04*…" in equation (1) corresponds to the test light emitted from the first optical fiber 81a and reaching the second optical fiber 31a via the first lens LE1 and the second lens LE2.

[0069] In addition, the “0.04*β*0.96” in parentheses in equation (1) corresponds to the reflected light RL21 incident on the first optical fiber 81a, 0.04 corresponds to the light in the test light that reaches the second optical fiber 31a and undergoes Fresnel reflection, and 0.96 corresponds to the light incident on the first optical fiber 81a in the light that passes through the first lens LE1 and the second lens LE2 after undergoing Fresnel reflection in the second optical fiber 31a.

[0070] In addition, the “0.96*0.96*β*0.96” in parentheses in equation (1) corresponds to the reflected light RL31 incident on the first optical fiber 81a, the first 0.96 corresponds to the test light incident on the second optical fiber 31a, the next 0.96 corresponds to the light emitted from the second optical fiber 31a in the light reflected in FBG32, and the next 0.96 corresponds to the light incident on the first optical fiber 81a in the light emitted from the second optical fiber 31a and passed through the first lens LE1 and the second lens LE2.

[0071] In formula (1), when the transmittance β of the group of the first lens LE1 and the second lens LE2 is set to 0.95, the intensity obtained by combining the intensities of the reflected light RL11, the reflected light RL21, and the reflected light RL31 as measured by the measuring unit 1001 is 84% ​​of the intensity of the test light TL1. That is, when the intensity of the reflected light measured by the measuring unit 1001 is 84% ​​or more of the intensity of the test light TL1, it can be said that the first optical fiber 81a and the second optical fiber 31a in the connecting unit 20 are normally connected.

[0072] Next, Figure 4 This diagram schematically illustrates the structure of the connector 20, and schematically shows the following state: due to the second optical fiber 31a not being properly fitted, it is connected to... Figure 3 Compared to the state shown, the distance between the second lens LE2 and the second optical fiber 31a becomes longer. Figure 4 Similarly, arrows indicate the test light and reflected light, while the diagram of the treatment light is omitted.

[0073] exist Figure 4 In the indicated state, when the test light TL1 exits from the first optical fiber 81a, a portion undergoes Fresnel reflection to become the reflected light RL11, which then propagates through the first optical fiber 81a. Additionally, in... Figure 4 In the illustrated state, the distance between the second lens LE2 and the second optical fiber 31a is longer than in the normal state. Therefore, the focal point of the second lens LE2 is... Figure 3 Compared to the previous state, the test light TL1, located upstream of the incident surface of the second fiber 31a in the direction of travel of the test light TL1, has a portion of the test light TL1 (test light TL12) passing through the second lens LE2 and does not enter the second fiber 31a. The light other than test light TL12 (test light TL11) enters the second fiber 31a. A portion of the test light TL11 reaching the second fiber 31a undergoes Fresnel reflection at the incident end of the second fiber 31a, becoming reflected light RL22. Reflected light RL22 enters the first fiber 81a. A portion of the reflected light RL22 undergoes Fresnel reflection when it enters the first fiber 81a.

[0074] Furthermore, the test light TL11 transmitted in the second optical fiber 31a is reflected by the FBG 32 to become the reflected light RL32. The reflected light RL32 is transmitted in the second optical fiber 31a in the opposite direction to the test light TL11. The reflected light RL32 reaches the first optical fiber 81a via the second lens LE2 and the first lens LE1, and is incident into the first optical fiber 81a. When the reflected light RL32 exits from the second optical fiber 31a, a portion of it undergoes Fresnel reflection at the incident end of the second optical fiber 31a. In addition, the reflected light RL32 also undergoes Fresnel reflection when it is incident into the first optical fiber 81a. The reflected light RL11, reflected light RL22, and reflected light RL32 are transmitted to the photodiode 401 via the first optical fiber 81a, the optical multiplier / splitter 701, and the filter 601. The intensity is measured by the measuring unit 1001 by combining the intensities of the transmitted reflected light RL11, reflected light RL22, and reflected light RL32.

[0075] When the intensity of the test light TL1 emitted from the first optical fiber 81a is set to 1, the transmittance of the group of the first lens LE1 and the second lens LE2 is set to β, and the coupling efficiency based on the distance between the second lens LE2 and the second optical fiber 31a is set to x, then... Figure 4 In the state shown, the intensity obtained by combining the intensities of reflected light RL11, reflected light RL22, and reflected light RL32 is obtained by adding the coupling efficiency x to equation (1) as shown in equation (2) below. It should be noted that for the coupling efficiency x, the state where the distance between the second lens LE2 and the second optical fiber 31a is normal, that is, the state where no test light TL11 is generated, is set to 1, and the state where the distance between the second lens LE2 and the second optical fiber 31a is abnormal and the test light TL1 does not incident on the second optical fiber 31a is set to 0.

[0076] 0.04+0.96*β*x*(0.04*β*x*0.96+0.96*0.96*β*x*0.96)(2)

[0077] With β set to 0.95 and coupling efficiency set to 0-1, the intensity obtained by combining the intensities of reflected light RL11, RL22, and RL32, as measured by the measuring unit 1001, falls within the range of 4% to 84% of the test light TL1. That is, if the intensity measured by the measuring unit 1001 is 4% or more but less than 84%, it can be said that the first optical fiber 81a and the second optical fiber 31a in the connection unit 20 are in a poorly connected state.

[0078] Next, Figure 5This diagram schematically illustrates the structure of the connector 20, and schematically shows the state where the first optical fiber 81a and the second optical fiber 31a are normally connected and the second optical fiber 31a is broken. Figure 5 In the diagram, arrows represent the test light and the reflected light, while the diagram of the treatment light is omitted.

[0079] When the second optical fiber 31a is broken, the test light TL1 transmitted through the second optical fiber 31a may sometimes be reflected at the break surface in the second optical fiber 31a. The light reflected at this break surface is designated as the reflected light RL33. The reflected light RL33 propagates in the second optical fiber 31a in the opposite direction to the test light TL1. The reflected light RL33 reaches the first optical fiber 81a via the second lens LE2 and the first lens LE1, and is incident into the first optical fiber 81a. A portion of the reflected light RL33 undergoes Fresnel reflection when exiting the second optical fiber 31a, and a portion also undergoes Fresnel reflection when incident into the first optical fiber 81a. The reflected lights RL11, RL21, and RL33 are transmitted to the photodiode 401 via the first optical fiber 81a, the optical multiplier / splitter 701, and the filter 601. The intensity obtained by combining the intensities of the reflected lights RL11, RL21, and RL33 is measured by the measuring unit 1001.

[0080] With the intensity of the test light TL1 emitted from the first optical fiber 81a set to 1, the transmittance of the group of the first lens LE1 and the second lens LE2 set to β, and the reflectance of the second optical fiber 31a at the fracture surface set to α, in Figure 5 In the state shown, the intensity obtained by combining the intensities of reflected light RL11, reflected light RL21 and reflected light RL33 is obtained by adding the reflectivity α to equation (1) as shown in equation (3) below.

[0081] 0.04+0.96*β*(0.04*β*0.96+0.96*α*0.96*β*0.96) (3)

[0082] α becomes a value of 0 to 0.04. Therefore, when the first optical fiber 81a and the second optical fiber 31a are normally connected and the second optical fiber 31a is broken, the intensity obtained by combining the intensities of reflected light RL11, reflected light RL21, and reflected light RL33, as measured by the measuring unit 1001, is an intensity within the range of 7.32% to 10.39% of the test light TL1. It should be noted that, as Figure 4As is the case, when the first optical fiber 81a and the second optical fiber 31a are not properly connected, the measured intensity can range from 7.32% to 10.39%. Therefore, if the intensity of the test light TL1 measured by the measuring unit 1001 is within the range of 7.32% to 10.39%, it can be said that the first optical fiber 81a and the second optical fiber 31a in the connection unit 20 are either poorly connected or properly connected but the second optical fiber 31a is broken.

[0083] Thus, the intensity of the reflected light measured by the measuring unit 1001 varies depending on the connection state of the first optical fiber 81a and the second optical fiber 31a, and the state of the second optical fiber 31a. Therefore, the connection state of the first optical fiber 81a and the second optical fiber 31a, and the state of the second optical fiber 31a, can be determined based on the intensity of the reflected light measured by the measuring unit 1001. In particular, according to the formula in (2) above, when the second optical fiber 31a is completely detached from the connection part 20, the intensity of the reflected light measured by the measuring unit 1001 is 4%. In contrast, according to the formula in (3) above, when the second optical fiber 31a is broken, the intensity of the reflected light measured by the measuring unit 1001 is 7.32% to 10.39%. Thus, the intensity of the reflected light measured by the measuring unit 1001 when the optical fiber is detached from the connection part 20 is lower than the intensity of the reflected light measured by the measuring unit 1001 when the optical fiber is broken, i.e., when the optical fiber is broken. Therefore, the two states of detachment and breakage can be completely distinguished.

[0084] Figure 6 This is a flowchart illustrating the process of determining the connection status between the first optical fiber 81a and the second optical fiber 31a. The control unit 100 executes... Figure 6 The processing shown involves the control unit 100 driving the first laser diode 301 and the second laser diode 302 and outputting therapeutic and experimental light. Figure 6 The processing is shown.

[0085] First, in step S101, the control unit 100 (measurement unit 1001) measures the intensity of the reflected light that is reflected from the test light TL1 output from the second laser diode 302 and reaches the photodiode 401 based on the current signal supplied from the photodiode 401.

[0086] Next, the control unit 100 (determination unit 1002) determines whether the intensity of the measured reflected light is less than a preset threshold C (step S102). The threshold C is stored in the storage unit. In this embodiment, the threshold C is a value of 7.32% of the intensity of the test light TL1. If the measured intensity is less than the threshold C (yes in step S102), the control unit 100 proceeds to step S103. Here, the control unit 100 determines that the first optical fiber 81a and the second optical fiber 31a are poorly connected.

[0087] In step S103, the control unit 100 (notification unit 1003) controls the display unit 200 to notify the connection unit 20 of the poor connection status between the first optical fiber 81a and the second optical fiber 31a using text and symbols, and then ends the process. Figure 6 The processing.

[0088] On the other hand, if the measured intensity is above threshold C (no in step S102), the control unit 100 proceeds to step S104. In step S104, the control unit 100 determines whether the measured intensity of the reflected light is above threshold C and below a preset threshold B. In this embodiment, threshold B is a value of 10.39% of the intensity of the test light TL1. Threshold B is stored in the storage unit. If the measured intensity of the reflected light is above threshold C and below threshold B (yes in step S104), the control unit 100 proceeds to step S105. Here, the control unit 100 determines that the first optical fiber 81a and the second optical fiber 31a are poorly connected or that the second optical fiber 31a is broken.

[0089] In step S105, the control unit 100 controls the display unit 200 to notify the connection unit 20 of any poor connection or breakage of the first optical fiber 81a and the second optical fiber 31a, using text and symbols, before ending the process. Figure 6 The control unit 100 can also issue a notification in step S105 urging confirmation of the connection between the first optical fiber 81a and the second optical fiber 31a. Additionally, the control unit 100 can also stop the driving of the first laser diode 301 before or after step S105.

[0090] If the measured intensity exceeds threshold B (not in step S104), the control unit 100 proceeds to step S106. In step S106, the control unit 100 determines whether the measured intensity of the reflected light exceeds threshold B and is less than a preset threshold A. In this embodiment, threshold A is 84% ​​of the intensity of the test light TL1. Threshold A is stored in the storage unit. Threshold A is an example of a first threshold.

[0091] If the intensity of the reflected light measured exceeds threshold B but is less than threshold A (yes in step S106), the control unit 100 proceeds to step S107. Here, the control unit 100 determines that the first optical fiber 81a and the second optical fiber 31a are poorly connected. In step S107, the control unit 100 controls the display unit 200 to notify the connection unit 20 of the poor connection between the first optical fiber 81a and the second optical fiber 31a using text and symbols, and then ends the process. Figure 6 The processing.

[0092] It should be noted that if the measured intensity is above threshold A (not in step S106), the control unit 100 proceeds to step S108. Here, the control unit 100 determines that the connection between the first optical fiber 81a and the second optical fiber 31a is normal and that the second optical fiber 31a is not broken. In step S108, the control unit 100 controls the display unit 200 to notify, using text and symbols, that the connection between the first optical fiber 81a and the second optical fiber 31a in the connection unit 20 is normal and that the second optical fiber 31a is not broken, and then ends the process. Figure 6 The processing.

[0093] As explained above, in the first embodiment, the connection status of the first optical fiber 81a and the second optical fiber 31a in the connection section 20 and the status of the second optical fiber 31a can be determined based on the measurement results of the intensity of the reflected light that is reflected in the test light TL1 and reaches the photodiode 401, and the determination results can be notified to the operator.

[0094] It should be noted that the values ​​of thresholds A, B, and C mentioned above are examples and are not limited to the values ​​described above. For example, if the second optical fiber 31a is broken and the distance between the second lens LE2 and the second optical fiber 31a is abnormal, the measured intensity of the reflected light may sometimes be less than 7.32% of the intensity of the test light TL1. Therefore, it is also possible that if the measured intensity is below threshold B, the control unit 100 determines that the first optical fiber 81a and the second optical fiber 31a are poorly connected or that the second optical fiber 31a is broken, and uses text or symbols to notify the connection unit 20 that the first optical fiber 81a and the second optical fiber 31a are poorly connected or that the second optical fiber 31a is broken. In addition, in the above embodiment, the value of threshold A is set to 84% of the value of the test light TL1, but it can also be set to 79% of the value of the test light TL1, for example, to provide a margin for determining whether a connection has been established. Furthermore, when the end face of the optical fiber is coated with an AR (Anti-Reflection) coating, the reflectivity of light at the end face is lower than that of Fresnel reflection (4%). Therefore, the values ​​of thresholds A, B, and C can be set according to the coating. It should be noted that in the above embodiment, the wavelength of the treatment light is in the range of 600 nm to 1500 nm, but when the end face of the optical fiber is coated with an AR coating, the wavelength of the treatment light is preferably in the range of 900 nm to 1050 nm. If the wavelength of the treatment light is set to the range of 900 nm to 1050 nm, the reflection of the treatment light and the test light at the end face of the optical fiber can be suppressed using an AR coating.

[0095] Alternatively, in this embodiment, the second laser diode 302 may be driven and activated whenever the operator presses a button on the operated unit 801. Figure 6 The processing. In this configuration, for example, the control unit 100, through processing corresponding to the first operation of the button, determines that the first optical fiber 81a and the second optical fiber 31a are in a state of poor connection or that the second optical fiber 31a is broken. For example, the operator receives this notification and reconnects the optical fibers in the connection unit 20. Afterwards, the control unit 100 may also process the second operation of the button accordingly. Figure 6 In the processing, if it is determined again that the first optical fiber 81a and the second optical fiber 31a are in a state of poor connection, or that the second optical fiber 31a is in a state of being broken, that is, if the result of each operation is that the judgment of poor connection occurs continuously, it is assumed that the poor connection can be improved by the operator reconnecting. Therefore, it is judged that the second optical fiber 31a is broken, and the operator is notified of the broken status using text or symbols. According to this structure, the operator can be notified of the broken status of the second optical fiber 31a.

[0096] In addition, as another example of poor fiber connection in the first embodiment, consider the following situation: due to the axial offset of the optical axis between the first lens LE1 and the second lens LE2, a test light TL12 is generated that does not incident on the second fiber 31a. In such a case, the coupling efficiency corresponding to the axial offset can be set as y and added to the equation (2), and thresholds A, B, and C can be set. For the coupling efficiency y, for example, the state where no axial offset occurs can be set to 1, and the state where the test light TL1 does not incident on the second fiber 31a due to the axial offset can be set to 0.

[0097] [Second Implementation]

[0098] Next, a second embodiment of the present invention will be described. Compared to the first embodiment, the second embodiment differs in that the diameter of the first optical fiber 81a is smaller than the diameter of the second optical fiber 31a, the method of connecting the first optical fiber 81a and the second optical fiber 31a in the connection section 20, and the processing performed by the control section 100. Other structural aspects are the same as in the first embodiment. Therefore, in the following description, descriptions of structures identical to those in the first embodiment will be omitted, and the differences from the first embodiment will be explained.

[0099] Figure 7 This is a schematic diagram showing an example of the connection state of the optical fiber in the connection section 20 of the second embodiment. Figure 7 The diagram shows a gapless connection between the first optical fiber 81b and the second optical fiber 31a. The first optical fiber 81b has a core diameter smaller than that of the second optical fiber 31a. The first optical fiber 81b is connected to an optical multiplexer / splitter 701 and transmits therapeutic and experimental light output from the optical multiplexer / splitter 701. The first optical fiber 81b and the second optical fiber 31a are mated together in the connector 20 via a sleeve and ferrule (not shown).

[0100] exist Figure 7 In the diagram, arrows represent the test light and the reflected light, while the treatment light is omitted. The test light TL1 is the test light output from the second laser diode 302. The test light TL1 is incident from the first optical fiber 81b into the second optical fiber 31a. The test light TL1, after propagating in the second optical fiber 31a, is reflected at FBG32 to become the reflected light RL31. The reflected light RL31 propagates in the second optical fiber 31a in the opposite direction to the test light TL1. The core diameter of the first optical fiber 81b is smaller than that of the second optical fiber 31a, therefore a portion of the reflected light RL31 is incident into the first optical fiber 81b. Figure 7 The reflected light RL51 shown represents the light incident on the core of the first optical fiber 81b from the reflected light RL31. Figure 7The reflected light RL52 shown represents the light in the reflected light RL31 that does not incident on the core of the first optical fiber 81b. The reflected light RL51 is transmitted to the photodiode 401 via the first optical fiber 81b, the optical multiplier / splitter 701, and the filter 601, and its intensity is measured by the measuring unit 1001.

[0101] With the intensity of the test light TL1 before it exits the first fiber 81b set to 1, the reflectivity of the test light TL1 at FBG32 set to 100%, and the connection loss caused by the difference between the core diameter of the first fiber 81b and the core diameter of the second fiber 31a set to γ, in Figure 7 The strength measured under the conditions shown is obtained from the following formula (4).

[0102] 1.00*γ (4)

[0103] In this embodiment, γ is the area ratio of the cross-sectional area of ​​the core of the first optical fiber 81b to the cross-sectional area of ​​the core of the second optical fiber 31a. For example, when the diameter of the core of the first optical fiber 81b is 105 μm and the diameter of the core of the second optical fiber 31a is 120 μm, γ becomes 0.766. The connection state between the first optical fiber 81b and the second optical fiber 31a is... Figure 7 In the state shown, and with γ = 0.766, the intensity of the reflected light RL51 measured by the measuring unit 1001 is 76.6% of the intensity of the test light TL1.

[0104] Next, Figure 8 This diagram schematically illustrates a state where, although the first optical fiber 81b and the second optical fiber 31a are normally connected without an air gap in the connection section 20, the second optical fiber 31a is broken. Figure 8 Similarly, arrows indicate the test light and reflected light, while the diagram of the treatment light is omitted.

[0105] like Figure 8 As shown, when the second optical fiber 31a is broken, the test light TL1 transmitted through the second optical fiber 31a is sometimes reflected at the break point. This light reflected at the break point is designated as the reflected light RL34. The reflected light RL34 propagates in the second optical fiber 31a in the opposite direction to the test light TL1. Since the core diameter of the first optical fiber 81b is smaller than that of the second optical fiber 31a, a portion of the reflected light RL34 is incident on the first optical fiber 81b. Figure 8 The reflected light RL53 shown represents the light incident on the first optical fiber 81b from the reflected light RL34. Figure 8The reflected light RL54 shown represents the light in the reflected light RL34 that does not incident on the first optical fiber 81b. The reflected light RL53 is transmitted to the photodiode 401 via the first optical fiber 81b, the optical multiplier / splitter 701, and the filter 601, and its intensity is measured by the measuring unit 1001.

[0106] With the intensity of the test light TL1 emitted from the first optical fiber 81b set to 1, the connection loss caused by the difference between the core diameter of the first optical fiber 81b and the core diameter of the second optical fiber 31a set to γ, and the reflectivity of the second optical fiber 31a at the fracture surface set to α, in Figure 8 The strength measured under the conditions shown is obtained from the following formula (5).

[0107] 1.00*γ*α (5)

[0108] α is a value between 0 and 0.04, therefore the connection state between the first optical fiber 81b and the second optical fiber 31a is as follows: Figure 8 In the state shown, and with γ = 0.766, the intensity of the reflected light RL53 measured by the measuring unit 1001 is within the range of 0% to 3.06% of the intensity of the test light TL1.

[0109] Next, Figure 9 This diagram schematically illustrates a state where the second optical fiber 31a is not broken and there is an air gap between the first optical fiber 81b and the second optical fiber 31a, resulting in a non-normal connection. Figure 9 In the diagram, arrows represent the test light and the reflected light, while the diagram of the treatment light is omitted.

[0110] exist Figure 9 In the illustrated configuration, a portion of the test light TL1 undergoes Fresnel reflection upon exiting the first optical fiber 81b, becoming reflected light RL11, which propagates through the first optical fiber 81b. Additionally, a portion of the test light TL1 exiting the first optical fiber 81b undergoes Fresnel reflection at the incident end of the second optical fiber 31a, becoming reflected light RL21. Reflected light RL21 is incident into the first optical fiber 81b. A portion of reflected light RL21 undergoes Fresnel reflection upon incident into the first optical fiber 81b.

[0111] Additionally, the light incident on the second optical fiber 31a from the test light TL1 propagates in the second optical fiber 31a and is reflected by the FBG 32 to become reflected light RL35. Reflected light RL35 propagates in the second optical fiber 31a in the opposite direction to the test light TL1. Reflected light RL35 exits from the second optical fiber 31a. As reflected light RL35 exits from the second optical fiber 31a, a portion undergoes Fresnel reflection at the incident end of the second optical fiber 31a.

[0112] The diameter of the first optical fiber 81b is smaller than that of the second optical fiber 31a, so a portion of the reflected light RL35 emitted from the second optical fiber 31a is incident on the first optical fiber 81b. Figure 9 The reflected light RL55 shown represents the light incident on the first optical fiber 81b from the reflected light RL35, and the reflected light RL56 represents the light in the reflected light RL35 that does not incident on the first optical fiber 81b. It should be noted that when the reflected light RL35 is incident on the first optical fiber 81b, a portion of it also undergoes Fresnel reflection.

[0113] The reflected light RL11, reflected light RL21 and reflected light RL55 are transmitted to the photodiode 401 via the first optical fiber 81b, the optical wavelength division multiplexer 701 and the filter 601. The intensity of the reflected light RL11, reflected light RL21 and reflected light RL55 is measured by the measuring unit 1001.

[0114] With the intensity of the test light TL1 before it exits the first fiber 81b set to 1, the reflectivity of the test light TL1 at FBG32 set to 100%, the connection loss caused by the difference in diameter between the first fiber 81b and the second fiber 31a set to γ, and the coupling efficiency between the first fiber 81b and the second fiber 31a set to x, in Figure 9 The intensity measured under the shown conditions is obtained by the following formula (6). It should be noted that, here, the coupling efficiency is obtained based on the air gap, and the state in which the first optical fiber 81b is connected to the second optical fiber 31a and the test light TL1 is all incident on the second optical fiber 31a is set to 1, and the state in which the test light TL1 is not incident on the second optical fiber 31a is set to 0.

[0115] 0.04+x 2 *γ*0.96 2 (0.04+0.96 2 ) (6)

[0116] When γ = 0.766, the intensity obtained by combining the intensities of reflected light RL11, RL21, and RL55, as measured by the measuring unit 1001, falls within the range of 4% to 71.2% of the test light TL1. That is, if the intensity measured by the measuring unit 1001 is 4% or more and 71.2% or less, it can be said that the connection between the first optical fiber 81b and the second optical fiber 31a in the connection section 20 is poor.

[0117] Thus, the intensity of the reflected light measured by the measuring unit 1001 varies depending on the connection state of the first optical fiber 81b and the second optical fiber 31a, and the state of the second optical fiber 31a. Therefore, the connection state of the first optical fiber 81b and the second optical fiber 31a, and the state of the second optical fiber 31a, can be determined based on the intensity of the reflected light measured by the measuring unit 1001. In particular, according to the aforementioned formula (6), when the second optical fiber 31a is completely detached from the connection part 20, the intensity of the reflected light measured by the measuring unit 1001 is 4%. In contrast, according to the aforementioned formula (5), when the second optical fiber 31a is broken, the intensity of the reflected light measured by the measuring unit 1001 is 0 to 3.06%. Thus, when the second optical fiber 31a is broken, the intensity of the reflected light measured by the measuring unit 1001 is lower than the intensity of the reflected light measured by the measuring unit 1001 when the second optical fiber 31a is detached from the connection part 20. Therefore, the two states of breakage and detachment can be completely distinguished.

[0118] Figure 10 This is a flowchart illustrating the process of determining the connection status between the first optical fiber 81b and the second optical fiber 31a. The control unit 100 executes... Figure 10 The processing shown, for example, involves the control unit 100 driving the first laser diode 301 and the second laser diode 302 and outputting therapeutic light and experimental light. Figure 10 The processing is shown.

[0119] First, in step S201, the control unit 100 (measurement unit 1001) measures the intensity of the reflected light that is reflected from the test light TL1 output from the second laser diode 302 and reaches the photodiode 401 based on the current signal supplied from the photodiode 401.

[0120] Next, the control unit 100 (determination unit 1002) determines whether the intensity of the measured reflected light is below a preset threshold D (step S202). In this embodiment, the threshold D is a value of 3.06% of the intensity of the test light TL1. The threshold D is stored in the storage unit. The threshold D is an example of a fourth threshold. If the measured intensity is below the threshold D (yes in step S202), the control unit 100 proceeds to step 203. Here, the control unit 100 determines that the second optical fiber 31a has broken.

[0121] In step S203, the control unit 100 (light source control unit 1004) determines whether at least one of the first laser diode 301 and the second laser diode 302 is being driven. If at least one of the first laser diode 301 and the second laser diode 302 is being driven (yes in step S203), the control unit 100 proceeds to step S204; if neither of the first laser diode 301 nor the second laser diode 302 is being driven (no in step S203), the control unit 100 proceeds to step S205.

[0122] If the control unit 100 proceeds to step S204, it stops driving the first laser diode 301 and the second laser diode 302 in step S204 and proceeds to step S205. In step S205, the control unit 100 controls the display unit 200 to notify the user of the broken optical fiber in the conduit 30 using text and symbols, and then ends the process. Figure 10 The processing.

[0123] On the other hand, if the measured intensity exceeds the threshold D (no in step S202), the control unit 100 proceeds to step S206. In step S206, the control unit 100 determines whether the measured intensity of the reflected light is above a preset threshold E and below a preset threshold F. In this embodiment, threshold E is 4% of the intensity of the test light TL1, and threshold F is 71.2% of the intensity of the test light TL1. Threshold E and threshold F are stored in the storage unit. Threshold E is an example of a second threshold, and threshold F is an example of a third threshold. If the measured intensity of the reflected light is above threshold E and below threshold F (yes in step S206), the control unit 100 proceeds to step S207. Here, the control unit 100 determines that the first optical fiber 81b and the second optical fiber 31a are poorly connected. In step S207, the control unit 100 controls the display unit 200 to notify the connection unit 20 of the poor optical fiber connection using text and symbols, and then ends the process. Figure 10 The processing.

[0124] If the measured intensity is neither above nor below the threshold E (not specified in step S206), the control unit 100 proceeds to step S208. In step S208, the control unit 100 determines whether the measured intensity of the reflected light is above or below a preset threshold G. In this embodiment, the threshold G is 76.6% of the intensity of the test light TL1. The threshold G is stored in the storage unit.

[0125] If the intensity of the reflected light measured is less than the threshold G (No in step S208), the control unit 100 proceeds to step S207. Here, the control unit 100 determines that the connection between the first optical fiber 81b and the second optical fiber 31a is faulty. Alternatively, if the intensity of the reflected light measured is greater than or equal to the threshold G (Yes in step S208), the control unit 100 proceeds to step S209. Here, the control unit 100 determines that the connection between the first optical fiber 81b and the second optical fiber 31a is normal and the second optical fiber 31a is not broken. In step S209, the control unit 100 controls the display unit 200 to notify the connection unit 20 that the optical fiber connection is normal and the optical fiber is not broken using text and symbols, and then ends the process. Figure 10 The processing.

[0126] It should be noted that, even though there is no air gap between the first optical fiber 81b and the second optical fiber 31a, the first optical fiber 81b and the second optical fiber 31a are axially offset. The intensity measured by the measuring unit 1001 becomes the following formula (7) with the coupling efficiency x based on the axial offset added to the above formula (4).

[0127] 1.00*γ*x 2 (7)

[0128] When x is in the range of 0 to 1, and there is no loss when the test light TL1 is incident from the first fiber 81b to the second fiber 31a, x = 1, and the intensity of the reflected light measured by the measuring unit 1001 is 76.6% of the intensity of the test light TL1. However, when there is a loss when the first fiber 81b and the second fiber 31a are offset and the test light TL1 is incident from the first fiber 81b to the second fiber 31a, and when the reflected light reflected from FBG32 is incident from the second fiber 31a to the first fiber 81b, the value of x is less than 1, and the intensity of the reflected light incident on the first fiber 81b is less than 76.6% of the intensity of the test light TL1. Therefore, the control unit 100 may, for example, proceed to step S207 in step S206 if the measured intensity of the reflected light is above threshold E and below threshold G. In this case, the control unit 100 determines that the first fiber 81b and the second fiber 31a are in a state of poor connection.

[0129] In the second embodiment, the connection status of the first optical fiber 81b and the second optical fiber 31a in the connection section 20 and the status of the second optical fiber 31a can be determined based on the measurement results of the intensity of the reflected light that is reflected in the test light TL1 and incident on the first optical fiber 81b, and the determination results can be notified to the operator.

[0130] [Variation Example]

[0131] The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments described above and can be implemented in various other ways. For example, the embodiments described above can be modified as follows to implement the present invention. It should be noted that the embodiments described above and the following modifications can also be combined separately. Solutions constructed by appropriately combining the constituent elements of the various embodiments and modifications described above are also included in the present invention. In addition, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader scope of the present invention is not limited to the embodiments and modifications described above, and various changes can be made.

[0132] In the first embodiment described above, the threshold A is set to 84% of the intensity of the test light TL1. However, in order to provide a margin for the determination of a normal connection, the threshold A may also be set to, for example, 79% of the intensity of the test light TL1.

[0133] In the second embodiment described above, the diameter of the core of the first optical fiber 81b is different from the diameter of the core of the second optical fiber 31a. However, the core diameters of the first optical fiber 81b and the second optical fiber 31a can also be set to be the same for splicing. In this case, the value of γ in equations (4) to (6) above is 1. In this case, the values ​​of threshold D, threshold E, threshold F, and threshold G can also be set according to the values ​​that can be taken when γ = 1 in equations (4) to (6) above.

[0134] In the second embodiment described above, the connection between the first optical fiber 81b and the second optical fiber 31a is a butt joint. However, instead of a butt joint, a spatial coupling structure using lenses, as in the first embodiment, can be used. In this case, the thresholds for judging fiber breakage, judging poor fiber connection, and judging normal fiber connection can be determined based on the transmittance of the group of the first lens LE1 and the second lens LE2, the coupling efficiency affected by the air gap and axial offset, Fresnel reflection, and the area ratio of the first optical fiber 81b to the second optical fiber 31a, and each judgment is made based on the determined thresholds.

[0135] In the first embodiment described above, the control unit 100 may determine that the connection between the first optical fiber 81a and the second optical fiber 31a is faulty, regardless of the intensity value, if the measured intensity is less than the threshold A. In this case, for example, if the operator receives a continuous notification that the connection is faulty even after reconnecting the first optical fiber 81a and the second optical fiber 31a in the connection unit 20, the operator can determine that the second optical fiber 31a is broken, rather than that the connection is faulty.

[0136] In the above-described embodiments, the display unit 200 notifies the user of poor fiber connection and broken fiber. However, a speaker can also be provided in the laser device 10, and the user can use sound through the speaker to notify the user of poor fiber connection and broken fiber.

[0137] In the first and second embodiments described above, the number of first laser diodes 301 serving as the light source for therapeutic light is one, but the number of first laser diodes 301 may also be multiple. When there are multiple first laser diodes 301, a combiner can be used to combine the therapeutic light output from the multiple first laser diodes 301 and input it to the beam combiner / splitter 701.

[0138] In the above-described embodiments, the therapeutic light is combined with a test light wave before being input into the light wave splitter 701, but it can also be combined with the test light wave between the light wave splitter 701 and the connecting part 20. The light wave splitter 701 can also be configured to combine multiple light waves in space, or it can be configured to combine light waves using a light combiner or the like.

[0139] Filter 601 may also become unnecessary depending on the structure. For example, when the optical wave combiner / splitter 701 is a WDM coupler, it can split waves with high extinction ratio and good efficiency, so it can be configured without filter 601.

[0140] The above-described embodiments are not limited to systems that output therapeutic lasers, but can be applied to systems that output lasers by detachably connecting optical fibers using connectors.

[0141] In the above embodiments, the catheter may also have a structure with a tap coupler. Figure 11 This is a diagram showing the structure of the conduit 30A equipped with a tap coupler 34. It should be noted that... Figure 11 The same reference numerals are used to label elements identical to those in conduit 30. Conduit 30A includes a second optical fiber 31a, optical fiber 31b, optical fiber 31c, FBG 32, conduit body 33, tap coupler 34, and terminal portion 35. Optical fiber 31b is an example of a second optical fiber. Terminal portion 35 is an example of a reflective portion.

[0142] Tapped coupler 34 is an asymmetric tapped coupler with 1×2 ports and a branch ratio of 90:10. An optical fiber 31b is connected to the main port of tapped coupler 34, where the branched light has a larger proportion. The test light TL1 transmitted through optical fiber 31b is reflected at FBG 32 and transmitted in the opposite direction to the test light TL1, and then transmitted to the laser device 10 via tapped coupler 34, second optical fiber 31a, connector 20, and first optical fiber 81a.

[0143] Additionally, the tapped coupler 34 connects an optical fiber 31c to a secondary port where the branched-out light has a smaller proportion. A terminal section 35 for terminating the optical fiber is connected to the front end of the optical fiber 31c.

[0144] The terminal section 35 may, for example, form a reflective film such that the reflectivity of the test light TL1 transmitted via the tap coupler 34 is 90% or higher. In this structure, when the optical fiber 31b breaks, the reflected light reflected at the break point and the reflected light from the terminal section 35 are transmitted to the laser device 10. Even when the optical fiber 31b is broken, there is still reflected light from the terminal section 35. Therefore, the intensity of the reflected light measured by the measuring unit 1001 when the second optical fiber 31a is detached from the connection section 20 is lower than the intensity of the reflected light measured by the measuring unit 1001 when the optical fiber 31b is broken. Therefore, similar to the first embodiment, the two states of detachment and breakage can be completely distinguished.

[0145] It should be noted that the terminal portion 35 may, for example, be the tip of the optical fiber 31c that is obliquely cut to reduce the reflectivity of the test light TL1 to 4% or less. In this structure, when the optical fiber 31b breaks, the reflected light reflected at the break point is transmitted to the laser device 10. Here, the intensity of the test light TL1 transmitted through the optical fiber 31b decreases at the tap coupler 34, thus reducing the amount of reflected light transmitted to the laser device 10 after reflection at the break point of the optical fiber 31b. On the other hand, the terminal portion 35 has low reflectivity, so the test light TL1 reaching the terminal portion 35 does not transmit to the laser device 10 even if it is reflected at the terminal portion 35. Thus, when the reflected light of the test light TL1 does not transmit to the laser device 10 from the terminal portion 35, the intensity of the reflected light measured by the measuring unit 1001 when the optical fiber 31b is broken is lower than the intensity of the reflected light measured by the measuring unit 1001 when the second optical fiber 31a is disconnected from the connection portion 20. Therefore, similar to the second embodiment, it is possible to completely distinguish between the two states of disconnection and wire breakage.

[0146] Industrial applicability

[0147] This invention can be applied to both the optical fiber connection status determination system and the optical fiber connection status determination method.

[0148] Explanation of reference numerals in the attached figures

[0149] 1. Laser System

[0150] 10. Laser device (connection status determination system)

[0151] 20 Connecting parts

[0152] 21a and 21b ferrules

[0153] 22a, 22b Connector Housings

[0154] 30, 30A catheters

[0155] 31a Second optical fiber

[0156] 31b and 31c optical fibers

[0157] 32 Fiber Bragg Grating (FBG)

[0158] 33. Catheter body

[0159] 34 Tap Coupler

[0160] 35 Terminal Department

[0161] 81a, 81b First Optical Fiber

[0162] 100 Control Department

[0163] 200 Display Unit

[0164] 301 First Laser Diode

[0165] 302 Second Laser Diode

[0166] 401 photodiode

[0167] 501 combiner

[0168] 601 Filter

[0169] 701 Optical Wavelength Demultiplexer

[0170] 801 Operations Department

[0171] 1001 Measurement Department

[0172] 1002 Judgment Department

[0173] 1003 Notification Department

[0174] 1004 Light Source Control Department

[0175] LE1 First Lens

[0176] LE2 Second lens.

Claims

1. A fiber optic connection status determination system, comprising determining the connection status of a first fiber and a second fiber in a connection section, wherein the connection section is detachably connected to the output side of the first fiber transmitting test light input from a light source and the input side of the second fiber receiving test light transmitted from and output from the first fiber, wherein... The optical fiber connection status determination system has the following features: The measuring unit measures the intensity of the reflected light in the test light that is reflected and transmitted through the first optical fiber; and The judgment unit determines the connection status of the first optical fiber and the second optical fiber in the connection unit based on the intensity measured by the measuring unit. The judgment unit determines the connection status whenever the measurement unit performs a measurement, and determines that the second optical fiber has been broken if the judgment result of poor connection occurs continuously.

2. The optical fiber connection status determination system according to claim 1, wherein, The intensity of the reflected light measured by the measuring unit differs when the second optical fiber is broken versus when the second optical fiber is detached from the connector.

3. The optical fiber connection status determination system according to claim 2, wherein, The intensity of the reflected light measured by the measuring unit when the second optical fiber is broken is greater than the intensity of the reflected light measured by the measuring unit when the second optical fiber is disconnected from the connection.

4. The optical fiber connection status determination system according to claim 1, wherein, The first optical fiber and the second optical fiber are spatially coupled in the connection portion. If the intensity is less than the first threshold, the judgment unit determines that the first optical fiber and the second optical fiber are poorly connected.

5. The optical fiber connection status determination system according to claim 3, wherein, The second optical fiber is connected to an optical fiber coupler. The test light emitted from a designated port among the plurality of ports from which the test light is emitted from the fiber optic coupler is reflected by the reflector that reflects the test light.

6. The optical fiber connection status determination system according to any one of claims 3 to 5, wherein, The measuring unit performs measurements whenever an operator performs a measurement operation.

7. The optical fiber connection status determination system according to claim 2, wherein, The intensity of the reflected light measured by the measuring unit when the second optical fiber is disconnected from the connector is greater than the intensity of the reflected light measured by the measuring unit when the second optical fiber is broken.

8. The optical fiber connection status determination system according to claim 7, wherein, The first optical fiber and the second optical fiber are mated and joined in the connection part. If the intensity is above the second threshold and below the third threshold which is greater than the second threshold, the judgment unit determines that the first optical fiber and the second optical fiber are poorly connected.

9. The optical fiber connection status determination system according to claim 7, wherein, The second optical fiber is connected to an optical fiber coupler.

10. The optical fiber connection status determination system according to claim 8, wherein, If the determination unit determines that the second optical fiber has been broken when the intensity is below a fourth threshold which is less than the second threshold.

11. The optical fiber connection status determination system according to any one of claims 1 to 5, wherein, The optical fiber connection status determination system includes a notification unit that notifies the first optical fiber and the second optical fiber of their connection status based on the determination result of the determination unit.

12. The optical fiber connection status determination system according to any one of claims 1 to 5, wherein, The laser beam that burns the human body is combined with the experimental light and input into the first optical fiber. If the determination unit determines that the second optical fiber has been broken, the output of the laser from the light source that outputs the laser is stopped.

13. A method for determining the connection status of an optical fiber, comprising determining the connection status of a first optical fiber and a second optical fiber in a connecting section, wherein the connecting section is detachably connected to the output side of the first optical fiber that transmits test light input from a light source and outputs the test light from the first optical fiber and the input side of the second optical fiber that receives the test light transmitted from and outputs the test light from the first optical fiber, wherein... The method for determining the connection status of the optical fiber includes: The measurement steps include measuring the intensity of the reflected light in the test light that is reflected and transmitted through the first optical fiber; and The judgment step, based on the intensity measured in the measurement step, determines the connection status between the first optical fiber and the second optical fiber. In the judgment step, the connection status is judged whenever a measurement is performed in the measurement step, and if the judgment result of poor connection occurs continuously, it is judged that the second optical fiber has been broken.

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