Optical cable closure switch monitoring device, system and method

Abstract

The application provides an optical cable splice closure switch monitoring device, which is arranged in an optical cable splice closure and connected with a monitoring device, and comprises a fixing module, a reflecting module and a reset mechanism; the fixing module comprises a fixing block and a fiber collimator, the fixing block is fixed in the optical cable splice closure, the fiber collimator is arranged on the fixing block, one end of the fiber collimator is a light transmission port, and the other end of the fiber collimator is connected with the monitoring device; the reflecting module comprises a movable block and a reflecting film, the movable block is hinged to the fixing block, and the reflecting film is embedded on the movable block; the reset mechanism is arranged between the movable block and the fixing block; the fiber collimator is used for receiving probe light emitted from the monitoring device and emitting the probe light to the reflecting film, the reflecting film is used for reflecting the probe light to form reflected light, and the fiber collimator is further used for receiving the reflected light and sending the reflected light to the monitoring device. The application also provides an optical cable splice closure switch monitoring system and an optical cable splice closure switch monitoring method.

Description

Technical Field

[0001] This invention relates to the field of optical fiber communication security technology, and in particular to a device, system and method for monitoring the switch of an optical cable splice box. Background Technology

[0002] As a core infrastructure of modern communication networks, optical fiber cables carry the transmission of massive amounts of information such as data, voice, and images. Their safe operation is directly related to the reliability and information security of communication networks.

[0003] During the installation of optical cables, the optical cable splice box is a key component for achieving optical fiber splicing. It is usually installed in underground concealed environments such as manholes and handholes. Such facilities are easy targets for illegal espionage activities. Eavesdroppers can open the splice box to access optical fiber eavesdropping devices and steal sensitive information transmitted in the optical cable.

[0004] However, traditional manual inspections or video surveillance are difficult to achieve effective monitoring. In existing technologies, the monitoring of the switch status of optical cable splice boxes generally relies on physical contact sensors, but these require additional power supply and are susceptible to environmental interference. Summary of the Invention

[0005] The purpose of this invention is to provide a device, system, and method for monitoring the switch of an optical cable splice box, which aims to solve or at least partially solve the shortcomings of the aforementioned background technology. It is not only simple in structure and requires no external power supply, but also does not affect the original function of the optical cable splice box. It can effectively monitor the illegal opening behavior of the optical cable splice box and ensure the security of communication infrastructure.

[0006] This invention provides a monitoring device for the switch of an optical cable splice box, which is installed inside the optical cable splice box and connected to a monitoring device. It includes a fixing module, a reflection module, and a reset mechanism. The fixing module includes a fixing block and an optical fiber collimator. The fixing block is fixed inside the optical cable splice box, and the optical fiber collimator is installed through the fixing block. One end of the optical fiber collimator is a light transmission port, and the other end is connected to the monitoring device via a communication optical cable. The reflection module includes a movable block and a reflective film. The movable block is hinged to the fixing block, and the reflective film is embedded in the movable block and is used to reflect light in conjunction with the light transmission port of the optical fiber collimator. The reset mechanism is located between the movable block and the fixing block. The optical fiber collimator is used to receive probe light emitted from the monitoring device and to emit probe light to the reflective film. The reflective film is used to reflect the probe light to form reflected light. The optical fiber collimator is also used to receive reflected light and send reflected light to the monitoring device. The monitoring device is used to measure the power of the reflected light and determine the reflection result.

[0007] Furthermore, the reflective film is a prism-type reflective film.

[0008] Furthermore, the fixing block has a through-hole for mounting a fiber optic collimator, which is installed inside the mounting hole.

[0009] Furthermore, the movable block has a recessed mounting groove on one side near the fixed block that matches the reflective film, and the reflective film is installed in the mounting groove.

[0010] Furthermore, the reset mechanism includes an elastic element, with its two ends abutting against a fixed block and a movable block, respectively.

[0011] Furthermore, the reset mechanism includes two magnetic blocks, which are respectively disposed on the fixed block and the movable block, and the same magnetic poles of the two magnetic blocks are arranged facing each other.

[0012] This invention also provides an optical cable splice box switch monitoring system, including the aforementioned optical cable splice box switch monitoring device and a monitoring device installed in the terminal room and connected to the optical cable splice box switch monitoring device. The monitoring device includes a light source, an optical power meter, and an optical circulator. The light source and the optical power meter are respectively connected to the optical circulator. The pigtail of the optical fiber collimator is connected to the optical circulator via a communication optical cable. The optical fiber collimator can receive probe light emitted from the light source and collimate and emit it to a reflective film. The optical fiber collimator can receive reflected light and send it to the optical power meter. The optical power meter is used to measure the power of the reflected light. The optical cable splice box switch monitoring device, the light source, the optical power meter, and the optical circulator constitute a complete optical signal transmission link.

[0013] Furthermore, the pigtail of the fiber collimator and the communication optical cable are spliced ​​using a single-mode fiber fusion splicing process, with a splicing loss of ≤0.1dB.

[0014] The present invention also provides a method for monitoring the switch of an optical cable splice box, applied to the above-mentioned optical cable splice box switch monitoring system, the steps of which are as follows:

[0015] S1. Reference calibration: With the optical cable splice box closed, measure the power of the reflected light using an optical power meter and record it as the standard reflected light power P0. Set the opening threshold α and closing threshold β of the optical cable splice box.

[0016] S2. Real-time monitoring: The light source continuously emits probe light, and the optical power meter continuously measures the power of the reflected light and records it as the reflected light power P;

[0017] S3. Status Judgment: Compare the reflected optical power P with the standard reflected optical power P0. When P≤αP0, the optical cable splice box is determined to be in the open state and an alarm signal is triggered; when P≥βP0, the optical cable splice box is determined to be in the closed state and the alarm signal is deactivated.

[0018] Furthermore, the opening threshold α is 0.6~0.7, and the closing threshold β is 0.85~0.95.

[0019] This invention provides a fiber optic splice box switch monitoring device. Through the cooperation of a fixed module, a reflection module, and a reset mechanism, it combines a mechanical structure with fiber optic sensing technology. Changes in the angle θ between the optical axis of the fiber optic collimator and the reflective film cause changes in the power of the reflected light received by the fiber optic collimator, resulting in high monitoring sensitivity. This allows for the collaborative construction of a mechanism to identify the open / closed state of the fiber optic splice box with monitoring equipment. Since the fiber optic collimator transmits signals to the monitoring equipment via a communication fiber optic cable, this fiber optic splice box switch monitoring device requires no external power supply. Compared to existing physical contact sensors, this fiber optic splice box switch monitoring device is not only simple in structure and requires no external power supply, but also does not affect the original function of the fiber optic splice box, overcoming the limitations of traditional sensors. Therefore, this fiber optic splice box switch monitoring device is low-cost and easy to deploy, possessing significant engineering application value in the field of communication infrastructure security protection.

[0020] The present invention provides an optical cable splice box switch monitoring system, which, through the cooperation of an optical cable splice box switch monitoring device and a monitoring equipment, realizes non-contact monitoring of the opening and closing status of the optical cable splice box, and can effectively monitor the behavior of illegally opening the optical cable splice box, thus ensuring communication security.

[0021] The present invention provides a method for monitoring the switch of an optical cable splice box, which can effectively monitor the behavior of illegally opening the optical cable splice box and meet the actual needs of security protection of communication infrastructure. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the installation of a fiber optic splice box switch monitoring device according to the present invention.

[0024] Figure 2 This is a perspective view of a fiber optic splice box switch monitoring device according to the present invention.

[0025] Figure 3 This is a cross-sectional view of a fiber optic splice box switch monitoring device according to the present invention. Figure 1 .

[0026] Figure 4 for Figure 4 A magnified diagram of point A in the middle.

[0027] Figure 5 for Figure 3 A three-dimensional view of the fixed block shown.

[0028] Figure 6 for Figure 3 The three-dimensional view of the active block shown.

[0029] Figure 7 This is a cross-sectional view of a fiber optic splice box switch monitoring device according to the present invention. Figure 2 .

[0030] Figure 8 This is a connection diagram of an optical cable splice box switch monitoring system according to the present invention.

[0031] Figure 9 This is a flowchart of a method for monitoring the switch of an optical cable splice box according to the present invention.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. Optical cable splice box switch monitoring device; 10. Fixing module; 11. Fixing block; 111. Mounting hole; 112. First pivot hole; 113. Spring limiting hole; 114. Fixing lug; 115. Fixing hole; 116. First mating groove; 12. Fiber optic collimator; 121. Optical transmission port; 122. Pigtail; 123. Optical axis; 2. Monitoring equipment; 20. Reflection module; 201. Light source; 202. Optical power meter; 203. Optical circulator; 2031. First port; 2032. Second port; 2033. Third port; 21. Movable block; 211. Mounting groove; 212. Connecting arm; 213. Second pivot hole; 214. Second mating groove; 22. Reflective film; 3. Optical cable splice box; 30. Reset mechanism; 31. Elastic element; 32. Magnetic block; 4. Communication optical cable; 40. Rotating shaft; 5. Heat shrink tubing. Detailed Implementation

[0034] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0035] Unless otherwise explicitly specified and limited, the terms "setup," "installation," and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms based on the specific circumstances.

[0036] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0037] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0038] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0039] Please see Figures 1-4 A fiber optic splice box switch monitoring device 1 is installed inside a fiber optic splice box 3 and connected to a monitoring device 2, including a fixing module 10, a reflection module 20 and a reset mechanism 30.

[0040] The fixed module 10 includes a fixed block 11 and an optical fiber collimator 12. The fixed block 11 is fixed on the inner side wall of the optical cable splice box 3. The optical fiber collimator 12 is installed through the fixed block 11. One end of the optical fiber collimator 12 is an optical transmission port 121, and the other end of the optical fiber collimator 12 is connected to the monitoring device 2 through the communication optical cable 4.

[0041] The reflection module 20 includes a movable block 21 and a reflective film 22. The movable block 21 is hinged to the fixed block 11. The reflective film 22 is embedded in the movable block 21 and is used to cooperate with the optical transmission port 121 of the fiber collimator 12 to reflect light.

[0042] The reset mechanism 30 is located between the movable block 21 and the fixed block 11.

[0043] More specifically, the pigtail 122 of the fiber optic collimator 12 is connected to the monitoring device 2 via the communication optical cable 4. The fiber optic collimator 12 is used to receive the probe light emitted from the monitoring device 2 and to transmit the probe light to the collimating reflective film 22 via the optical transmission port 121. The reflective film 22 is used to reflect the probe light to form reflected light. The fiber optic collimator 12 is also used to receive the reflected light and to transmit the reflected light to the monitoring device 2 via the optical transmission port 121. The monitoring device 2 is used to measure the power of the reflected light and to determine the reflection result.

[0044] When the optical cable splice box 3 is closed, the reset mechanism 30 is compressed by the cover of the optical cable splice box 3 to bring the movable block 21 close to the fixed block 11. The angle θ between the optical axis 123 of the optical fiber collimator 12 and the reflective film 22 is 90°. Then, most or all of the reflected light formed by the reflective film 22 is received by the optical fiber collimator 12. In this state, the power of the reflected light received by the optical fiber collimator 12 is the maximum.

[0045] When the optical cable splice box 3 is opened, the reset mechanism 30 resets to support one end of the movable block 21 away from the fixed block 11. The angle θ between the optical axis 123 of the optical fiber collimator 12 and the reflective film 22 is greater than 90°. Therefore, the reflected light formed by the reflective film 22 is not received by the optical fiber collimator 12, and the power of the reflected light received by the optical fiber collimator 12 is reduced.

[0046] As described above, the optical cable splice box switch monitoring device 1 provided by this invention, through the cooperation of the fixing module 10, the reflection module 20, and the reset mechanism 30, combines a mechanical structure with optical fiber sensing technology. Changes in the angle between the optical axis 123 of the optical fiber collimator 12 and the reflective film 22 will cause changes in the power of the reflected light received by the optical fiber collimator 12, resulting in high monitoring sensitivity. This allows it to work in conjunction with the monitoring device 2 to establish a mechanism for identifying the open / closed state of the optical cable splice box 3. Since the optical fiber collimator 12 transmits signals to the monitoring device 2 via the communication optical cable 4, this optical cable splice box switch monitoring device 1 does not require an external power supply. Compared to existing physical contact sensors, this optical cable splice box switch monitoring device 1 is not only simple in structure and requires no external power supply, but also does not affect the original function of the optical cable splice box 3, overcoming the limitations of traditional sensors. Therefore, this optical cable splice box switch monitoring device 1 is low in cost and easy to deploy, possessing significant engineering application value in the field of communication infrastructure security protection.

[0047] Furthermore, please refer to Figure 4 and Figure 5 The fixing block 11 has a through-hole 111 that mates with the fiber optic collimator 12, and the fiber optic collimator 12 is installed in the through-hole 111. The through-hole 111 extends vertically through the upper and lower surfaces of the fixing block 11, and the inner diameter of the through-hole 111 matches the outer diameter of the fiber optic collimator 12, thereby ensuring that the optical axis 123 of the fiber optic collimator 12 is perpendicular to the upper surface of the fixing block 11.

[0048] More specifically, the end face of the optical transmission port 121 of the fiber optic collimator 12 does not extend beyond the upper surface of the fixing block 11.

[0049] Furthermore, please refer to Figure 4 and Figure 6The movable block 21 has a recessed mounting groove 211 on its side near the fixed block 11, which mates with the reflective film 22. The thickness of the reflective film 22 is less than or equal to the depth of the mounting groove 211, and the reflective film 22 is installed within the mounting groove 211. In this embodiment, the reflective film 22 is adhered to the mounting groove 211. The mounting groove 211 is formed on the lower surface of the movable block 21, and the depth of the mounting groove 211 matches the thickness of the reflective film 22, thereby ensuring that the surface of the reflective film 22 is flush with the lower surface of the movable block 21.

[0050] In this embodiment, the reflective film 22 is a prism-type reflective film.

[0051] For more details, please see Figure 2 , Figure 5 and Figure 6 The fixed block 11 and the movable block 21 are hinged together by a rotating shaft 40, which is a cylindrical pin structure. A first rotating shaft hole 112 is provided through the side wall of the fixed block 11, and the axis of the first rotating shaft hole 112 is perpendicular to the axis of the mounting hole 111. Connecting arms 212 extend downwards from both sides of the movable block 21, and second rotating shaft holes 213 are provided through the connecting arms 212. The first rotating shaft hole 112 and the second rotating shaft hole 213 are connected, and the inner diameters of the first rotating shaft hole 112 and the second rotating shaft hole 213 are respectively matched with the outer diameter of the rotating shaft 40. The rotating shaft 40 passes through the first rotating shaft hole 112 and the second rotating shaft hole 213, realizing the hinged connection between the fixed block 11 and the movable block 21, forming a rotatable mechanical linkage structure.

[0052] The fixing block 11 has a fixing lug 114 extending from one side of the inner wall of the optical cable splice box 3. A fixing hole 115 is provided through the fixing lug 114. The fixing block 11 is installed on the inner wall of the optical cable splice box 3 by fasteners passing through the fixing hole 115.

[0053] Please see Figures 2-4 When the optical cable splice box 3 is closed, the optical cable splice box switch monitoring device 1, supported by the reset mechanism 30, ensures that the movable block 21 is always abutted against the inner top wall of the cover of the optical cable splice box 3, thereby ensuring that the angle θ between the reflective film 22 on the movable block 21 and the optical axis 123 of the fiber optic collimator 12 is precisely 90°. When the optical cable splice box 3 is open, the optical cable splice box switch monitoring device 1, through the reset mechanism 30, changes the angle θ between the reflective film 22 and the optical axis 123 of the fiber optic collimator 12, thereby working with the monitoring device 2 to establish a mechanism for identifying the open and closed state of the optical cable splice box 3 based on changes in light reflection intensity.

[0054] Furthermore, in this embodiment, the reset mechanism 30 includes an elastic element 31. The two ends of the elastic element 31 abut against the fixed block 11 and the movable block 21, respectively, providing elastic support to the movable block 21. The elastic element 31 can be a spring, a spring sheet, etc.; in this embodiment, a spring is selected as the elastic element 31. The fixed block 11 has a spring limiting hole 113 recessed corresponding to the elastic element 31. One end of the elastic element 31 is installed in the spring limiting hole 113, achieving the limiting installation of the elastic element 31. More specifically, the inner diameter of the spring limiting hole 113 matches the outer diameter of the elastic element 31.

[0055] Furthermore, in another embodiment, please refer to Figure 7 The reset mechanism 30 includes two magnetic blocks 32, which are respectively disposed on the fixed block 11 and the movable block 21, with the same magnetic poles of the two magnetic blocks 32 facing each other. Since the same magnetic poles repel each other, there is a repulsive force between the two magnetic blocks 32, which provides support for the movable block 21. The fixed block 11 and the movable block 21 have corresponding recesses of a first mating groove 116 and a second mating groove 214 on the magnetic blocks 32, respectively. The first mating groove 116 and the second mating groove 214 are arranged opposite to each other, and the two magnetic blocks 32 are respectively installed within the first mating groove 116 and the second mating groove 214.

[0056] When the optical cable splice box 3 is closed, the two magnetic blocks 32 are pressed against each other by the box body and the cover of the optical cable splice box 3.

[0057] When the optical cable splice box 3 is opened, the two magnetic blocks 32 are in a state of being far apart from each other due to the repulsive force.

[0058] Please see Figure 1 and Figure 8 The present invention also provides an optical cable splice box switch monitoring system, including any of the optical cable splice box switch monitoring devices 1 in the above embodiments and a monitoring device 2 installed in the terminal equipment room. The monitoring device 2 includes a light source 201, an optical power meter 202 and an optical circulator 203, and the light source 201 and the optical power meter 202 are respectively connected to the optical circulator 203.

[0059] The pigtail 122 of the fiber optic collimator 12 is connected to the optical circulator 203 through the redundant fiber core of the communication optical cable 4. The fiber optic collimator 12 can receive the probe light emitted from the light source 201 and collimate it to the reflective film 22. The fiber optic collimator 12 can receive the reflected light and send it to the optical power meter 202. The optical power meter 202 is used to measure the power of the reflected light.

[0060] The optical cable splice box switch monitoring device 1, light source 201, optical power meter 202, and optical circulator 203 constitute a complete optical signal transmission link.

[0061] As described above, the optical cable splice box switch monitoring system provided by the present invention, through the cooperation of the optical cable splice box switch monitoring device 1 and the monitoring equipment 2, realizes non-contact monitoring of the opening and closing status of the optical cable splice box 3, which can effectively monitor the behavior of illegally opening the optical cable splice box 3 and ensure communication security.

[0062] More specifically, the optical circulator 203 has a first port 2031, a second port 2032, and a third port 2033. During operation, the light source 201 emits probe light, which enters the optical circulator 203 through the first port 2031. The probe light is coupled to the fiber optic collimator 12 through the second port 2032. The fiber optic collimator 12 receives the reflected light and sends it to the optical power meter 202 through the third port 2033.

[0063] Furthermore, the pigtail 122 of the optical fiber collimator 12 is fused with the redundant fiber core of the communication optical cable 4 using a single-mode optical fiber fusion splicing process, with a fusion loss ≤0.1dB.

[0064] In addition, a heat shrink tubing 5 is provided at the splice point between the pigtail 122 of the optical fiber collimator 12 and the redundant fiber core of the communication optical cable 4, and the heat shrink tubing 5 serves as a protective function.

[0065] The working process of the optical cable splice box switch monitoring system provided by this invention:

[0066] (1) The light source 201 emits a probe light, which enters the fiber collimator 12 through the optical circulator 203. The fiber collimator 12 emits the probe light toward the reflective film 22, which reflects the probe light to form reflected light.

[0067] (2) The fiber collimator 12 receives the reflected light and sends it to the optical circulator 203. The reflected light is then sent to the optical power meter 202 via the optical circulator 203.

[0068] (3) The optical power meter 202 receives the reflected light and measures the power of the reflected light.

[0069] (4) Determine the open / closed state of the optical cable splice box 3 based on the power change of the reflected light.

[0070] Additionally, please see Figure 9 The present invention also provides a method for monitoring the switch of an optical cable splice box 3, which is applied to the above-mentioned optical cable splice box switch monitoring system, and the steps are as follows:

[0071] S1. Reference calibration: With the optical cable splice box 3 closed, the power of the reflected light is measured by the optical power meter 202 and recorded as the standard reflected light power P0. The opening threshold α and closing threshold β of the optical cable splice box 3 are set.

[0072] S2. Real-time monitoring: The light source 201 continuously emits probe light, and the optical power meter 202 continuously measures the power of the reflected light and records it as the reflected light power P.

[0073] S3. Status Judgment: Compare the reflected light power P with the standard reflected light power P0. When P≤αP0, it is determined that the optical cable splice box 3 is in the open state and an alarm signal is triggered. When P≥βP0, it is determined that the optical cable splice box 3 is in the closed state and the alarm signal is deactivated.

[0074] More specifically, the opening threshold α and the closing threshold β were determined through experimental testing. Specifically, the opening threshold α is 0.6~0.7 and the closing threshold β is 0.85~0.95.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An optical cable closure switch monitoring device, which is arranged in an optical cable closure (3) and connected with a monitoring device (2), characterized in that, The application relates to a cable splice closure switch monitoring device (1), which comprises the following parts: a fixing module (10) comprising a fixing block (11) and a fiber collimator (12), the fixing block (11) is fixed in the box body of the cable splice closure (3), the fiber collimator (12) is arranged on the fixing block (11) in a penetrating mode, one end of the fiber collimator (12) is a light transmission port (121), the other end of the fiber collimator (12) is connected with the monitoring device (2) through a communication optical cable (4); a reflection module (20) comprising a movable block (21) and a reflection film (22), the movable block (21) is hingedly connected with the fixing block (11), the reflection film (22) is embedded on the movable block (21) and is used for cooperating with the light transmission port (121) of the fiber collimator (12) to realize light reflection; a reset mechanism (30) arranged between the movable block (21) and the fixing block (11); the fiber collimator (12) is used for receiving probe light emitted from the monitoring device (2) and emitting the probe light to the reflection film (22), the reflection film (22) is used for reflecting the probe light to form reflected light, the fiber collimator (12) is further used for receiving the reflected light and sending the reflected light to the monitoring device (2), and the monitoring device (2) is used for measuring the power of the reflected light and judging the reflection result.

2. The cable closure switch monitoring apparatus of claim 1, wherein, The reflection film (22) is a prism type reflection film.

3. The cable closure switch monitoring apparatus of claim 1, wherein, The fixing block (11) is provided with a mounting hole (111) matched with the fiber collimator (12) in a penetrating mode, and the fiber collimator (12) is mounted in the mounting hole (111).

4. The cable closure switch monitoring apparatus of claim 1, wherein, The movable block (21) is recessed with a mounting groove (211) matched with the reflection film (22) on one side close to the fixing block (11), and the reflection film (22) is mounted in the mounting groove (211).

5. The cable closure switch monitoring apparatus of claim 1, wherein, The reset mechanism (30) comprises elastic members (31), and the two ends of the elastic members (31) abut against the fixing block (11) and the movable block (21) respectively.

6. The cable closure switch monitoring apparatus of claim 1, wherein, The reset mechanism (30) comprises two magnetic blocks (32), and the two magnetic blocks (32) are arranged on the fixing block (11) and the movable block (21) respectively, and the two magnetic blocks (32) are arranged with the same magnetic poles facing each other.

7. An optical cable splice closure switch monitoring system comprising the optical cable splice closure switch monitoring device (1) according to any one of claims 1-6 and a monitoring equipment (2) disposed in a terminal room and connected with the optical cable splice closure switch monitoring device (1), the monitoring equipment (2) comprising a light source (201), an optical power meter (202) and an optical circulator (203), the light source (201) and the optical power meter (202) being connected with the optical circulator (203) respectively, characterized in that, The tail fiber (122) of the fiber collimator (12) is connected with the optical circulator (203) through the communication optical cable (4), the fiber collimator (12) can receive probe light emitted from the light source (201) and collimate and emit the probe light to the reflection film (22), the fiber collimator (12) can receive the reflected light and send the reflected light to the optical power meter (202), and the optical power meter (202) is used for measuring the power of the reflected light; The cable splice closure switch monitoring device (1), the light source (201), the optical power meter (202) and the optical circulator (203) form a complete optical signal transmission link.

8. The fiber optic cable splice tray switch monitoring system of claim 7, wherein, The tail fiber (122) of the fiber collimator (12) and the communication optical cable (4) are fused by using a single-mode optical fiber fusion process, and the fusion loss is less than or equal to 0.1 dB.

9. An optical cable closure switch monitoring method, characterized by, The steps of the application applied to the optical cable splice closure switch monitoring system of claim 7 are as follows: S1, reference calibration: in the closed state of the optical cable splice closure (3), the power of the reflected light is measured by the optical power meter (202), and recorded as the standard reflected light power P0. The opening threshold α and the closing threshold β of the optical cable splice closure (3) are set; S2, real-time monitoring: the light source (201) continuously emits the probe light, and the optical power meter (202) continuously measures the power of the reflected light and records it as the reflected light power P; S3, state judgment: comparing the reflected light power P with the standard reflected light power P0, when P≤αP0, it is determined that the optical cable splice closure (3) is in the open state and the alarm signal is triggered; when P≥βP0, it is determined that the optical cable splice closure (3) is in the closed state and the alarm signal is removed.

10. The optical cable splice tray switch monitoring method of claim 9, wherein, The opening threshold α is 0.6-0.7, and the closing threshold β is 0.85-0.95.

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