Hydrophone based on Fabry-Perot sensor

Abstract

The invention discloses a hydrophone based on a Fabry-Perot sensor, and the hydrophone comprises a housing which is provided with a first accommodation cavity, a second accommodation cavity and a sound receiving port, and the sound receiving port is communicated with external liquid; the Fabry-Perot sensor is arranged in the first accommodating cavity, the Fabry-Perot sensor comprises an optical fiber and a Fabry-Perot cavity diaphragm, and a Fabry-Perot cavity is arranged between the end face of the optical fiber and the Fabry-Perot cavity diaphragm; the waterproof supporting assembly is arranged in the second containing cavity, and the waterproof supporting assembly is suitable for blocking the communication state of the sound receiving opening and the first containing cavity, so that the two sides of the Fabry-Perot cavity diaphragm are located in the gas environment, and the external liquid pressure only acts on the waterproof supporting assembly. According to the invention, the supporting capability and the anti-pressure capability of the water-proof diaphragm of the hydrophone are improved through the water-proof supporting assembly, the Fabry-Perot sensor cavity diaphragm in the hydrophone is located in a gas environment, the detection capability and the deep water anti-pressure performance of the Fabry-Perot sensor cavity diaphragm are improved, and meanwhile, the application requirements of a test environment on vibration and pressure resistance of the Fabry-Perot sensor cavity diaphragm are met.

Description

Technical Field

[0001] This invention relates to the field of partial discharge signal monitoring of submarine cables, and specifically to a hydrophone based on a Fabry-Perot sensor. Background Technology

[0002] Optical microphones are based on the principle of Fabry-Perot fiber optic sensors and measure sound signals through optical interference. They have advantages such as high sensitivity and resistance to electromagnetic interference. However, their core component, the Fabry-Perot diaphragm, is easily damaged by excessive pressure difference in underwater high-pressure environments.

[0003] In existing technologies, some solutions employ liquid-filled structures to address the pressure resistance issue. For example, the high-pressure-resistant FP cavity hydrophone probe device disclosed in Chinese patent CN116499572A balances the pressure on both sides of the Fabry-Perot cavity diaphragm through a water-tight cap and a constant-pressure connecting hole structure. However, the Fabry-Perot cavity diaphragm of the FP cavity is the dividing point between the gas and liquid phases, and one side of the Fabry-Perot cavity diaphragm is still in contact with the liquid. Since the viscosity of the liquid is much greater than that of the gas, the viscosity of the liquid will affect the vibration performance of the Fabry-Perot cavity diaphragm, thereby restricting the response of the FP detector to certain frequency band acoustic signals and limiting the detection sensitivity of the acoustic frequency band. Summary of the Invention

[0004] In view of this, the present invention provides a hydrophone based on a Fabry-Perot sensor to solve the problem that existing hydrophone technology cannot simultaneously meet the application requirements of the testing environment for the vibration characteristics and pressure resistance of the Fabry-Perot sensor cavity diaphragm.

[0005] This invention provides a hydrophone based on a Fabry-Perot sensor, comprising: The housing has a first accommodating cavity, a second accommodating cavity, and a sound receiving port, the sound receiving port being in communication with an external liquid; A Fabry-Perot sensor is disposed within a first accommodating cavity. The Fabry-Perot sensor includes an optical fiber and a Fabry-Perot cavity diaphragm, with a Fabry-Perot cavity disposed between the end face of the optical fiber and the Fabry-Perot cavity diaphragm. A water-proof support assembly is disposed within a second accommodating cavity. The water-proof support assembly is adapted to block the communication between the sound receiving port and the first accommodating cavity, so that both sides of the Fabry-Perot diaphragm are in a gaseous environment, and that external liquid pressure acts only on the water-proof support assembly.

[0006] The beneficial effects of the hydrophone based on the Fabry-Perot sensor are as follows: by blocking the connection between the receiver and the first accommodating cavity through the water-proof support assembly, both sides of the Fabry-Perot cavity diaphragm are in a gaseous environment, which is different from the way the Fabry-Perot cavity diaphragm is in a liquid environment on one side. This can reduce the vibration resistance of the Fabry-Perot cavity diaphragm, eliminate the inhibition of the Fabry-Perot cavity diaphragm vibration by the viscosity of the liquid, and significantly improve the detection sensitivity.

[0007] The water-proof support assembly isolates the external liquid from the Fabry-Perot cavity diaphragm. The water-proof support assembly directly withstands the external liquid pressure, while the Fabry-Perot cavity diaphragm senses sound pressure changes indirectly only through a gaseous medium, avoiding direct contact with the high-pressure liquid and significantly improving deep-water pressure resistance. Therefore, this invention can simultaneously meet the application requirements of testing environments regarding the vibration performance and pressure resistance of the Fabry-Perot sensor cavity diaphragm.

[0008] When the Fabry-Perot diaphragm vibrates in a gaseous environment, the resonant frequency is mainly determined by the stiffness and mass of the diaphragm itself and is not affected by the external liquid load. By eliminating the liquid load, the overall detection frequency band of the hydrophone is broadened.

[0009] In one optional embodiment, the waterproof support assembly includes: A water-proof diaphragm is disposed at the end of the sound-receiving port; A support body is disposed on the side of the water-proof diaphragm away from the sound-receiving port. The support body is fixedly connected to the inner wall of the second accommodating cavity and is used to support the water-proof diaphragm.

[0010] In one alternative embodiment, the support is a honeycomb structure, which is composed of symmetrically arranged regular polygonal cells.

[0011] In one alternative embodiment, the support is a diamond cell structure, wherein the diamond cell structure uses a regular tetrahedron as the basic unit.

[0012] In one alternative embodiment, the aperture of the sound-receiving port gradually increases from the side closer to the waterproof support assembly to the side farther away from the waterproof support assembly.

[0013] The beneficial effects of the above technical solution are as follows: the gradually varying aperture forms an acoustic funnel, converging externally diffused sound waves to the water-resistant support component, thereby increasing the sound pressure intensity acting on the water-resistant diaphragm and directly improving the response sensitivity of the Fabry-Perot sensor to weak signals. The large aperture design on the outer side can buffer the impact of water flow, reducing the velocity gradient when water enters the sound receiving port, reducing turbulent eddies and bubble generation, suppressing fluid noise, and avoiding interference with the detection of effective acoustic signals.

[0014] In one optional embodiment, the housing includes a first screw and a second screw, the first accommodating cavity and the second accommodating cavity are disposed on the first screw, and the sound receiving port is disposed on the second screw; the inner wall of the second accommodating cavity is provided with an internal thread, the outer wall of the second screw is provided with an external thread, and the second screw is threadedly fitted with the second accommodating cavity and sealed by curing with glue.

[0015] In one alternative embodiment, the outer surface of the first screw is provided with a threaded interface for connecting a counterweight component.

[0016] In one optional embodiment, the inner diameter of the second accommodating cavity is larger than the inner diameter of the first accommodating cavity, and a limiting step is formed between the second accommodating cavity and the first accommodating cavity, and the water-proof support assembly contacts the limiting step; When assembling the waterproof support assembly, apply glue evenly to the outer cylindrical surface of the waterproof support assembly and the inner surface of the first screw. Then, press the waterproof support assembly onto the limiting step using the second screw. After the glue cures, the waterproof support assembly is fixed.

[0017] In one alternative embodiment, the Fabry-Perot sensor further includes a Fabry-Perot sensor housing, which is sealed within a first accommodating cavity by epoxy adhesive.

[0018] In one optional embodiment, the Fabry-Perot cavity diaphragm is disposed at the end of the Fabry-Perot sensor housing, the optical fiber is disposed inside the Fabry-Perot sensor housing, and there is a gap between the end face of the optical fiber and the Fabry-Perot cavity diaphragm to form the Fabry-Perot cavity; The Fabry-Perot cavity diaphragm and the waterproof support assembly have a gap and form a gas cavity.

[0019] In summary, the technical solution of the present invention has the following advantages: This invention employs a natural structure (diamond cell) or a biomimetic structure (honeycomb) to enhance the support capacity of the hydrophone's waterproof diaphragm and improve its pressure resistance. The Fabry-Perot sensor cavity diaphragm within the hydrophone is placed in a gaseous environment to further enhance its detection capability and deep-water pressure resistance. The hydrophone has a simple structure and can be manufactured using existing processing techniques. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the honeycomb structure of the present invention; Figure 3 This is a schematic diagram of the diamond unit cell structure of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Housing; 11. First screw; 111. Threaded interface; 12. Second screw; 13. First receiving cavity; 14. Second receiving cavity; 15. Sound receiving port; 2. Waterproof support assembly; 21. Waterproof diaphragm; 22. Support body; 3. Fabry-Perot sensor; 31. Optical fiber; 311. Optical fiber end face; 32. Fabry-Perot cavity diaphragm; 33. Fabry-Perot cavity; 34. Fabry-Perot sensor housing; 35. Gas cavity; 36. Epoxy adhesive. 4. Incident light, 5. First reflected light, 6. Second reflected light. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Optical microphones are a new type of sensor that uses optical interferometry to measure sound signals. They have advantages such as high sensitivity, strong resistance to electromagnetic interference, and good insulation performance, and have huge application demands in fields such as power, medical, and petrochemical industries. Sound signals in applications such as marine exploration and fault monitoring of submarine output cables in offshore wind farms can theoretically be detected by optical microphones. However, optical microphones based on Fabry-Perot fiber optic sensors use silicon wafers coated with a diaphragm as the second reflective surface to form the Fabry-Perot cavity. To improve the sensitivity of sound wave detection, the silicon wafer thickness is between tens of micrometers. During underwater operations, the diaphragm itself is not strong enough to withstand the pressure of deep water, making it difficult to use in high-pressure environments. Therefore, how to improve the pressure resistance of the diaphragm becomes a key issue that needs to be considered in the design of hydrophones based on Fabry-Perot sensors.

[0025] In existing technologies, some solutions employ liquid-filled structures to address the pressure resistance issue. For example, the high-pressure-resistant FP cavity hydrophone probe device disclosed in Chinese patent CN116499572A balances the pressure on both sides of the Fabry-Perot cavity diaphragm through a water-tight cap and a constant-pressure connecting hole structure. However, the Fabry-Perot cavity diaphragm of the FP cavity is the dividing point between the gas and liquid phases, and one side of the Fabry-Perot cavity diaphragm is still in contact with the liquid. Since the viscosity of the liquid is much greater than that of the gas, the contact between the Fabry-Perot cavity diaphragm and the liquid will increase the vibration damping, weaken the response to weak sound waves, and thus affect the vibration performance of the Fabry-Perot cavity diaphragm. This restricts the response of the FP detector to sound wave signals in certain frequency bands and limits the detection sensitivity of the sound wave frequency band.

[0026] Existing research uses nitrile rubber diaphragms as a water-resistant and sound-transmitting medium to reduce sound wave loss. However, to enhance sound wave transmission, the nitrile diaphragm is relatively thin, which limits the use of hydrophones based on FP sensors in higher pressure environments.

[0027] Based on this, the present invention provides a hydrophone based on a Fabry-Perot sensor, which can isolate the force of deep water pressure on the Fabry-Perot probe diaphragm, preventing damage to the sensor diaphragm, and also allows both sides of the FP cavity diaphragm to be in a gaseous environment, enhancing its sensitivity to sound wave signal detection.

[0028] According to an embodiment of the present invention, a hydrophone based on a Fabry-Perot sensor is provided, combined with... Figure 1 As shown, it includes a housing 1, a Fabry sensor 3, and a water-resistant support assembly 2.

[0029] The housing 1 is provided with a first accommodating cavity 13, a second accommodating cavity 14, and a sound receiving port 15, which is in communication with the external liquid.

[0030] The Fabry-Perot sensor 3 is disposed in the first accommodating cavity 13. The Fabry-Perot sensor 3 includes an optical fiber 31 and a Fabry-Perot cavity diaphragm 32. A Fabry-Perot cavity 33 is disposed between the end face of the optical fiber 31 and the Fabry-Perot cavity diaphragm 32.

[0031] The water-proof support assembly 2 is disposed in the second accommodating cavity 14. The water-proof support assembly 2 is adapted to block the communication between the sound receiving port 15 and the first accommodating cavity 13, so that both sides of the Fabry cavity diaphragm 32 are in a gas environment, and the external liquid pressure acts only on the water-proof support assembly 2.

[0032] The aforementioned hydrophone based on the Fabry-Perot sensor blocks the connection between the receiver 15 and the first accommodating cavity 13 through a water-proof support assembly, so that both sides of the Fabry-Perot cavity diaphragm 32 are in a gaseous environment, compared to one side of the Fabry-Perot cavity diaphragm 32 being in a liquid environment. This reduces the vibration resistance of the Fabry-Perot cavity diaphragm 32, eliminates the inhibition of the Fabry-Perot cavity diaphragm 32 vibration by the viscosity of the liquid, and significantly improves the detection sensitivity.

[0033] The water-proof support assembly 2 isolates the external liquid from the Fabry-Perot cavity diaphragm 32. The water-proof support assembly 2 directly bears the external liquid pressure, while the Fabry-Perot cavity diaphragm 32 senses changes in sound pressure indirectly only through a gaseous medium, avoiding direct contact with high-pressure liquid and significantly improving deep-water pressure resistance. Therefore, this embodiment can simultaneously meet the application requirements of the testing environment for the vibration performance and pressure resistance of the Fabry-Perot sensor cavity diaphragm.

[0034] When the Fabry-Perot cavity diaphragm 32 vibrates in a gaseous environment, the resonant frequency is mainly determined by the stiffness and mass of the diaphragm itself and is not affected by the external liquid load. By eliminating the liquid load, the overall detection frequency band of the hydrophone is broadened.

[0035] The hydrophone based on the Fabry sensor described above has a simple structure and can be manufactured using existing processing techniques.

[0036] In some embodiments, the waterproof support assembly 2 includes a waterproof membrane 21 and a support body 22.

[0037] A water-resistant diaphragm 21 is disposed at the end of the receiver 15, allowing water in the probe's working environment to come into contact with the water-resistant diaphragm 21 through the receiver 15. The water-resistant diaphragm 21 can be made of a flexible material with matching acoustic impedance to ensure efficient penetration of sound waves while preventing water from entering the internal gas environment.

[0038] The support body 22 is located on the side of the water-proof diaphragm 21 away from the sound-receiving port 15. The support body 22 is fixedly connected to the inner wall of the second accommodating cavity 14. The support body 22 is used to support the water-proof diaphragm 21. The water-proof diaphragm 21 and the support body 22 are sealed with glue.

[0039] In some embodiments, such as Figure 2 As shown, the support 22 has a honeycomb structure, which is composed of symmetrically arranged regular polygonal cells. The honeycomb structure is the optimal topological structure for covering a two-dimensional plane and is the basic structure of a honeycomb. It is a structure composed of multiple regular hexagonal cells, with all openings facing downwards or to one side, arranged back-symmetrically. This structure has excellent geometric and mechanical properties, and therefore has wide applications in materials science. It can provide a high-strength, effective planar support for the pressure-resistant, waterproof diaphragm of a hydrophone. The area of ​​the regular hexagons can be adjusted according to the pressure resistance requirements to obtain different pressure resistance effects.

[0040] As an alternative embodiment, such as Figure 3 As shown, the support 22 has a diamond unit cell structure. In crystallography, the diamond structure is also known as the diamond cubic crystal structure, in which each atom forms a regular tetrahedron with four adjacent atoms; the regular tetrahedron is used as the basic unit cell of its topological structure. The entire structure has strong stability and high load-bearing capacity, and can provide stronger support force with the same material.

[0041] The aforementioned support 22 can be 3D printed, directly outputting structures of different sizes based on computer modeling. This method is simple and the accuracy meets application requirements. The support 22's structural parameters can be adjusted as needed to adapt to complex scenarios such as deep-sea high pressure and wide-band detection, thereby comprehensively improving the hydrophone's pressure resistance, detection sensitivity, and long-term reliability.

[0042] Existing hydrophone technology cannot simultaneously meet the application requirements of the testing environment regarding the vibration characteristics and pressure resistance of the Fabry-Perot sensor cavity diaphragm. To address these issues, this invention employs a natural structure (diamond cell) or a biomimetic structure (honeycomb) to enhance the support capacity of the hydrophone's waterproof diaphragm, while simultaneously improving the hydrophone's pressure resistance. Furthermore, the Fabry-Perot sensor cavity diaphragm within the hydrophone is placed in a gaseous environment to enhance its detection capability and deep-water pressure resistance.

[0043] In some embodiments, the aperture of the receiver 15 gradually increases from the side closer to the water-proof support component 2 to the side farther away from the water-proof support component 2, thus forming an outwardly expanding horn-shaped structure. In this embodiment, the gradually changing aperture forms an acoustic funnel, converging externally diffused sound waves to the water-proof support component 2, thereby increasing the sound pressure intensity acting on the water-proof diaphragm and directly improving the response sensitivity of the Fabry-Perot sensor to weak signals. The large aperture design on the outer side can buffer the impact of water flow, reducing the velocity gradient when water enters the receiver, reducing turbulent eddies and bubble generation, suppressing fluid noise, and avoiding interference with the detection of effective acoustic signals.

[0044] More specifically, the sound receiver 15 can be designed as a conical surface with a small cross-section near the water-proof diaphragm 21 and a large cross-section away from the water-proof diaphragm 21. The outline of the sound receiver 15 is the waistline of the trapezoidal cross-section, that is, the cross-section of the central axis of the sound receiver 15 is trapezoidal.

[0045] In some embodiments, the housing 1 includes a first screw 11 and a second screw 12, a first accommodating cavity 13 and a second accommodating cavity 14 are disposed on the first screw 11, and a sound receiving port 15 is disposed on the second screw 12. The inner wall of the second accommodating cavity 14 is provided with an internal thread, and the outer wall of the second screw 12 is provided with an external thread. The second screw 12 and the second accommodating cavity 14 are threadedly fitted and sealed by curing with glue, thereby making the probe structure a double-screw threaded sealing structure.

[0046] In this embodiment, the precise fit between the inner thread of the second accommodating cavity 14 and the outer thread of the second screw forms a rigid constraint in both the axial and circumferential directions, ensuring the coaxiality of the sound receiving port 15 and the second accommodating cavity 14, and preventing distortion of the sound signal transmission path due to assembly misalignment. The thread gap between the first screw 11 and the second screw 12 is filled with adhesive (such as epoxy resin or silicone rubber) and then cured, forming a double barrier of threaded mechanical seal combined with colloidal chemical seal, which can withstand greater water pressure.

[0047] If the sound inlet or the receiving cavity is damaged, the second screw 12 can be unscrewed after the glue has been softened by heating, and the damaged part can be replaced separately.

[0048] In some embodiments, the outer surface of the first screw 11 is provided with a threaded interface 111 for connecting a counterweight component, which may be a sinker counterweight. After the required sinker counterweight is installed at the threaded interface of the first screw 11, the problem of the hydrophone probe being too light and being swept away by waves or undersea currents, thus failing to sink to the predetermined detection depth, can be avoided.

[0049] In some embodiments, the inner diameter of the second accommodating cavity 14 is larger than the inner diameter of the first accommodating cavity 13, and a limiting step is formed between the second accommodating cavity 14 and the first accommodating cavity 13. A water-proof membrane 21 and its support 22 are placed between the inner step hole of the first screw 11 and the threaded end face of the second screw 12, perpendicular to their axes. The water-proof support assembly 2 contacts the limiting step.

[0050] During the assembly of the waterproof support assembly 2, adhesive is pre-applied evenly to the outer cylindrical surface of the waterproof support assembly 2 and the inner surface of the first screw 11. The second screw 12 is then used to position and press the waterproof support assembly 2 onto the limiting step. After the adhesive cures, the waterproof support assembly 2 is fixed. The adhesive applied during assembly (such as epoxy resin or silicone rubber) not only achieves mechanical locking after curing but also forms a chemical sealing layer, providing double protection for water tightness and ensuring the reliability and durability of the hydrophone during long-term deployment.

[0051] After the water-proof support assembly 2 is assembled, the internal thread of the first screw 11 and the external thread of the second screw 12 engage to press the water-proof diaphragm 21 and the water-pressure-resistant support body 22 between them, ensuring a tight fit between the water-proof diaphragm 21 and the support body 22. This effectively isolates external water pressure penetration and prevents seawater from seeping into the internal chamber and affecting the acoustic performance of the Fabry-Perot sensor. This pressing structure further enhances the overall rigidity after the adhesive cures, ensuring the stability of the water-proof support assembly 2 in the high-pressure environment of the deep sea and preventing component displacement or seal failure due to water pressure fluctuations.

[0052] In some embodiments, the Fabry-Perot sensor 3 further includes a Fabry-Perot sensor housing 34, which is sealed within the first accommodating cavity 13 by epoxy adhesive 36. A Fabry-Perot cavity diaphragm 32 is disposed at the end of the Fabry-Perot sensor housing 34, and an optical fiber 31 is disposed within the Fabry-Perot sensor housing 34. The end face of the optical fiber 31 is spaced from the Fabry-Perot cavity diaphragm 32 to form a Fabry-Perot cavity 33 (FP cavity). A space is formed between the Fabry-Perot cavity diaphragm 32 and the water-proof support assembly 2 to form a gas cavity 35. Both the Fabry-Perot cavity 33 and the gas cavity 35 are sealed cavities to ensure that the Fabry-Perot cavity diaphragm 32 deforms only under sound pressure.

[0053] The specific detection principle of the hydrophone based on the Fabry sensor mentioned above is as follows: The incident light 4, after being reflected back by the fiber end face 311, is reflected by the first reflected light 5, which interferes with the second reflected light 6, which is reflected back by the Fabry-Perot cavity diaphragm 32.

[0054] The water-resistant diaphragm 21, under the support of the support 22, resists water pressure while transmitting sound waves from the water into the sealed gas cavity 35. When the Fabry-Perot cavity diaphragm 32 is subjected to external signals, such as sound wave pressure deformation, the sound waves directly act on the Fabry-Perot cavity diaphragm 32, causing deformation of the Fabry-Perot cavity diaphragm 32, resulting in a change in the length of the Fabry-Perot cavity 33. Consequently, the phase and amplitude of the interference light between the first reflected light 5 and the second reflected light 6 will change. By demodulating the interference light with a demodulator connected to the other end of the optical fiber, the information carried by the interference light can be interpreted.

[0055] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A hydrophone based on a Fabry-Perot sensor, characterized in that, include: The housing (1) is provided with a first accommodating cavity (13), a second accommodating cavity (14), and a sound receiving port (15), which is in communication with the external liquid; A Fabry-Perot sensor (3) is disposed in a first accommodating cavity (13). The Fabry-Perot sensor (3) includes an optical fiber (31) and a Fabry-Perot cavity diaphragm (32). A Fabry-Perot cavity (33) is disposed between the end face of the optical fiber (31) and the Fabry-Perot cavity diaphragm (32). Waterproof support assembly (2) is disposed in the second accommodating cavity (14). The waterproof support assembly (2) is adapted to block the communication between the sound receiving port (15) and the first accommodating cavity (13) so that both sides of the Fabry cavity diaphragm (32) are in a gas environment and the external liquid pressure acts only on the waterproof support assembly (2).

2. The hydrophone based on a Fabry-Perot sensor according to claim 1, characterized in that, The waterproof support assembly (2) includes: A water-proof diaphragm (21) is disposed at the end of the sound-receiving port (15); Support body (22) is disposed on the side of the water-proof diaphragm (21) away from the sound-receiving port (15). The support body (22) is fixedly connected to the inner wall of the second accommodating cavity (14). The support body (22) is used to support the water-proof diaphragm (21).

3. The hydrophone based on a Fabry-Perot sensor according to claim 2, characterized in that, The support (22) is a honeycomb structure, which is composed of symmetrically arranged regular polygonal single cells.

4. The hydrophone based on a Fabry-Perot sensor according to claim 2, characterized in that, The support (22) is a diamond cell structure, which uses a regular tetrahedron as the basic unit.

5. The hydrophone based on a Fabry-Perot sensor according to claim 1, characterized in that, The aperture of the sound-receiving port (15) gradually increases from the side closer to the water-proof support assembly (2) to the side farther away from the water-proof support assembly (2).

6. The hydrophone based on a Fabry-Perot sensor according to claim 1, characterized in that, The housing (1) includes a first screw (11) and a second screw (12). The first accommodating cavity (13) and the second accommodating cavity (14) are disposed on the first screw (11), and the sound receiving port (15) is disposed on the second screw (12). The inner wall of the second accommodating cavity (14) is provided with an internal thread, and the outer wall of the second screw (12) is provided with an external thread. The second screw (12) is threadedly fitted with the second accommodating cavity (14) and sealed by curing with glue.

7. The hydrophone based on a Fabry-Perot sensor according to claim 6, characterized in that, The outer surface of the first screw (11) is provided with a threaded interface for connecting the counterweight component.

8. The hydrophone based on a Fabry-Perot sensor according to claim 6, characterized in that, The inner diameter of the second accommodating cavity (14) is larger than the inner diameter of the first accommodating cavity (13), and a limiting step is formed between the second accommodating cavity (14) and the first accommodating cavity (13), and the water-proof support assembly (2) is in contact with the limiting step; When assembling the waterproof support assembly (2), glue is applied to the outer cylindrical surface of the waterproof support assembly (2) and the inner surface of the first screw (11) in advance. The waterproof support assembly (2) is pressed onto the limiting step by the second screw (12). The waterproof support assembly (2) is fixed after the glue cures.

9. The hydrophone based on a Fabry-Perot sensor according to claim 1, characterized in that, The Fabry sensor (3) also includes a Fabry sensor housing (34), which is sealed in the first accommodating cavity (13) by epoxy glue.

10. The hydrophone based on a Fabry-Perot sensor according to claim 9, characterized in that, The Fabry-Perot cavity diaphragm (32) is disposed at the end of the Fabry-Perot sensor housing (34), and the optical fiber (31) is disposed inside the Fabry-Perot sensor housing (34). The end face of the optical fiber (31) and the Fabry-Perot cavity diaphragm (32) have a gap and form the Fabry-Perot cavity (33). The Fabry-Perot cavity diaphragm (32) has a gap with the water-proof support assembly (2) and forms a gas cavity (35).

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