A microsphere cavity inertial mass block composite high-frequency vibration regulation structure

Abstract

The application discloses a kind of microsphere cavity inertia mass block compound high-frequency vibration regulation and control structure, belong to optical sensing technical field.The whole rigid body displacement of hollow microsphere cavity is too small under high-frequency acoustic field excitation, and the problem that stress distribution divergence leads to insufficient sensing sensitivity, the application proposes a kind of microsphere cavity inertia mass block compound high-frequency vibration regulation and control structure.The structure includes optical fiber cantilever beam, microsphere cavity resonator at optical fiber end and adheres to microsphere cavity inertia mass block.The mass block is fixed by rigid connection interface, utilizes its mass load effect and inertia damping effect, significantly increases the overall displacement of microsphere cavity in frequency 90kHz~224kHz.Meanwhile, utilize the stiffness mismatch between mass block and microsphere cavity, form significant stress concentration effect at rigid connection interface.The application improves the displacement amplitude of sensor by mass block, enhances local photoelastic effect by stress concentration, efficiently improves the stability of light coupling, and can be used for high-frequency acoustic signal high-sensitivity detection.

Description

Technical Field

[0001] This invention relates to the field of optical sensing technology, and specifically to a high-frequency vibration control structure composed of a microsphere cavity and an inertial mass block. Background Technology

[0002] Optical microcavities are optical devices that utilize the reflection, resonance, and cyclic propagation of light within microscale resonant structures to achieve optical field confinement. Among them, whispering-gallery mode optical microcavities enable light that meets the resonance condition to propagate multiple times along the circumference of the microcavity. They are characterized by small size, high quality factor, and sensitivity to changes in cavity geometry and material refractive index, and can be used to detect physical quantities such as pressure, vibration, sound field, and refractive index.

[0003] A hollow optical microsphere is a whispering-gallery style microcavity with a spherical, thin-walled structure. When external sound pressure acts on the surface of the hollow microsphere, it causes elastic deformation of the spherical cavity wall and changes in the stress distribution within the cavity. This alters the effective radius and refractive index of the material, resulting in changes in the microcavity's resonant wavelength, transmitted light intensity, or resonant characteristics. By detecting these changes in optical parameters, the external sound pressure signal can be sensed.

[0004] Existing hollow optical microcavity acoustic pressure sensing structures typically rely on the elastic deformation of the cavity wall itself to convert sound pressure into optical signals. The mechanical response is related to factors such as the outer diameter of the microcavity, wall thickness, material elastic modulus, support method, and the incident direction of the sound wave. When the sound pressure propagates along the microcavity axis, the microcavity and the supporting structure jointly bear the periodic sound pressure load. When the sound pressure amplitude is small, due to the structural stiffness of the spherical cavity wall, the effective displacement and strain generated by the cavity wall are small, resulting in limited changes in the microcavity's optical resonance parameters, thus limiting the ability to detect weak sound pressure signals.

[0005] To improve the acoustic pressure response of hollow optical microcavities, a common approach is to reduce the microcavity wall thickness, thereby decreasing the equivalent stiffness of the cavity wall and increasing its compressive deformation. However, reducing the wall thickness may decrease its mechanical strength, impact resistance, and fabrication yield, and make it more susceptible to breakage during fabrication, installation, and use. Increasing the microcavity size or changing the support structure can also adjust the mechanical response of the microcavity, but this may simultaneously cause problems such as increased device size, altered mechanical modes, and decreased structural consistency.

[0006] This type of structure is mainly suitable for planar diaphragms or planar spring-sensitive elements. Its mechanical boundary conditions, deformation patterns, and optical detection principles differ from those of hollow optical microspheres, making direct application to spherical thin-walled optical microspheres difficult. In particular, the mass loading location, mass block size, and microsphere support method all affect the mechanical resonant frequency, stress concentration state, and effective optical sensing area of ​​the spherical shell. If the structural design is unreasonable, it may only cause a localized increase in stress, without effectively improving the acoustic pressure response of the microsphere's optical region.

[0007] Therefore, there is a need to provide a hollow optical microsphere cavity sensitization structure suitable for axial acoustic pressure detection, which can improve the effective displacement or strain of the microsphere cavity under acoustic pressure without simply relying on reducing the wall thickness of the microsphere cavity, while taking into account the mechanical strength, structural stability and optical detection performance of the device, thereby improving the response capability of the hollow optical microsphere cavity to weak acoustic pressure signals.

[0008] In summary, the existing technology lacks a microsphere acoustic sensing structure that can adapt to high-frequency environments and achieve displacement enhancement and stress enhancement through structural optimization. Summary of the Invention

[0009] The purpose of this invention is to provide a high-frequency vibration control structure composed of a microsphere cavity and an inertial mass block, which aims to solve the technical problems of insufficient sensing sensitivity caused by the small overall rigid body displacement and divergent stress distribution of existing hollow microsphere cavities under high-frequency sound field excitation.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A high-frequency vibration control structure composed of a microsphere cavity and an inertial mass block includes an optical fiber cantilever beam (1), a microsphere cavity (2) disposed at the end of the optical fiber cantilever beam, and at least one mass block (3) adhered to the outer surface of the microsphere cavity resonator.

[0012] The microsphere cavity (2) is a hollow thin-walled spherical structure. The mass block (3) is attached to the pole region of the microsphere cavity (2) away from the optical fiber cantilever beam (1) by point adhesion, and forms a rigid connection interface with the microsphere cavity (2). The optical fiber cantilever beam, microsphere cavity, and mass block are arranged sequentially along the sound pressure propagation direction, forming an asymmetric composite oscillator system.

[0013] Furthermore, the pole region is a preset vibration deformation sensitive area determined based on the mechanical mode shape of the microsphere cavity at the target frequency. A rigid connection interface is formed between the mass block and the outer surface of the pole of the microsphere cavity resonator. The contact area of ​​the rigid connection interface accounts for a preset proportion of the total theoretical contact area between the mass block and the microsphere cavity resonator, so that the mechanical stress is concentrated at the rigid connection interface.

[0014] Furthermore, the ratio of the effective contact area of ​​the rigid connection interface to the bottom surface area of ​​the mass block facing the hollow microsphere resonator is 1% to 5%. By limiting the contact area of ​​the rigid connection interface, the constraint of the connection structure on the free deformation of the spherical shell is reduced while ensuring the reliable connection of the mass block, and the mechanical stress is concentrated in the connection transition area between the mass block and the microsphere.

[0015] Furthermore, the fiber cantilever beam uses standard hollow optical fiber, one end of which is fixed to an external rigid support (4), and the other end of the hollow optical fiber (5) to be used for microsphere formation is molten through the electrode (6) by a fiber optic fusion splicer. Then, pressure is applied to the inside of the optical fiber through a syringe (8) connected to the capillary (7) to form the microsphere resonator (9). The microsphere resonator (9) is a hollow thin-walled spherical shell structure made of silicon dioxide, and its equatorial region is used for optical coupling with the tapered optical fiber. The position of the mass block (3) avoids the equatorial region used for optical coupling to reduce the influence of the mass loading structure on the coupling of the whispering-gallery mode optical field. The fiber cantilever beam serves as the mechanical support cantilever of the entire composite oscillator system.

[0016] Furthermore, the shell wall thickness of the microsphere resonator (9) is optimized and its thickness range is set to support high-quality factor whispering-gallery mode resonance, while ensuring that the sphere has sufficient mechanical flexibility to respond to high-frequency acoustic excitation; the outer surface of the microsphere resonator is polished to minimize surface scattering loss.

[0017] Furthermore, the mass block (3) is made of a high-density, high-Young's modulus mass material, including but not limited to gold, tungsten, platinum or their alloys; the density of the mass block (3) is significantly greater than the material density of the microsphere cavity resonator (9), thereby introducing a significant difference in inertial mass in the composite oscillator system.

[0018] Furthermore, by setting the material density, diameter, thickness, mass, bonding position, and dimensions of the rigid connection interface of the mass block, the equivalent mass and equivalent stiffness of the composite vibration structure are adjusted so that the target mechanical resonance frequency of the composite vibration structure is within the range of 90kHz to 224kHz. Under a sound pressure of 1Pa, the overall rigid displacement of the micro-spherical cavity resonator (9) is enhanced by the inertial damping effect. Under this condition, the maximum displacement amplitude of the surface of the micro-spherical cavity resonator is on the order of 10−4μm. At the same time, by utilizing the stiffness mismatch between the mass block (3) and the micro-spherical cavity resonator (9), a stress concentration zone is constructed at the rigid connection interface, which efficiently converts the external sound field energy into local strain energy.

[0019] Furthermore, the geometry of the mass block (3) is set as a cylinder; the size of the mass block (3) ranges from micrometers to millimeters, and its bottom surface contact area covers the pre-set stress-sensitive area on the surface of the microsphere resonator (9).

[0020] Furthermore, the number of the mass blocks (3) can be one or more; when the number of the mass blocks (3) is multiple, the multiple mass blocks (3) are respectively disposed at different preset positions on the outer surface of the microsphere resonator (9). By changing the number, mass, relative position and distribution of the multiple mass blocks (3), the equivalent mass distribution, mechanical vibration mode and resonant frequency of the composite oscillator system can be adjusted to meet the vibration control requirements under different directions and different target frequencies.

[0021] Furthermore, the present invention also provides a high-frequency vibration modulation method based on the above structure, comprising the following steps: coupling laser to the microsphere resonator through the tapered optical fiber (14) to excite the whispering-gallery mode resonance; when the high-frequency sound wave (10) acts on the structure, a leftward sound pressure (11) is generated on the optical fiber cantilever beam (1), the microsphere cavity (2), and the mass block (3). The sensitizing effect of the mass block (3) is used to increase the overall displacement of the microsphere cavity (2) and force the stress generated by the sound pressure (11) to concentrate towards the connection interface; by detecting the drift of the whispering-gallery mode resonance wavelength, the high-frequency sound signal is demodulated based on the elasto-optic effect and geometric deformation caused by local stress concentration.

[0022] Furthermore, the mass block (3) is rigidly fixed to the surface of the microsphere cavity resonator (9) by UV curing adhesive process; the shear modulus of the connection interface is configured to ensure that there is no relative sliding between the mass block (3) and the microsphere cavity resonator (9) during high-frequency vibration.

[0023] Furthermore, the resonant frequency of the composite oscillator system is tuned by adjusting the material, size and adhesion position of the mass block (3) so that its operating frequency covers the frequency range of the target high-frequency sound wave, thereby achieving enhanced response to sound waves of a specific frequency.

[0024] Furthermore, the present invention also provides an experimental method for measuring the displacement of the micro-cavity resonator (9). The laser rangefinder (13) is controlled by the three-dimensional displacement platform (12) to be aligned directly above the micro-cavity resonator (9). When the microcavity is displaced, the measurement can be performed.

[0025] Furthermore, compared with the prior art, the present invention also provides a high-frequency vibration modulation structure with the following beneficial effects:

[0026] (1) The present invention increases the equivalent mass of the microcavity vibration structure by setting a mass block at the axial pole of the hollow optical microsphere cavity, thereby adjusting the mechanical natural frequency of the microcavity, so that the mechanical response frequency band of the microcavity can be designed according to the frequency of the sound pressure or vibration signal to be measured, thereby improving the response capability of the microcavity structure to the vibration signal of the target frequency band.

[0027] (2) The mass block and the hollow optical microsphere cavity are arranged along the direction of sound pressure propagation. When the sound pressure propagates along the axis of the microcavity, the mass block and the microsphere cavity together generate an axial mechanical response, which is beneficial to increase the displacement and strain changes of the microsphere cavity near the target mechanical resonance frequency, thereby enhancing the conversion effect of the external sound pressure signal to the changes in the optical resonance parameters of the microcavity.

[0028] (3) The present invention does not require simply reducing the wall thickness of the microsphere cavity to improve the mechanical response of the microsphere cavity. Under the condition of maintaining the basic wall thickness and structural integrity of the microsphere cavity, its vibration characteristics can be adjusted by mass loading, thereby taking into account the acoustic pressure response capability, mechanical strength and structural stability of the microsphere cavity, and reducing the risk of damage to the thin-walled microsphere cavity during processing, assembly and use.

[0029] (4) By changing the material density, diameter, thickness of the mass block and the connection dimensions between the mass block and the microsphere cavity, the equivalent mass and equivalent stiffness of the vibration structure can be adjusted, thereby achieving controllable adjustment of the mechanical natural frequency and amplitude frequency response characteristics, and having good parameter designability and application adaptability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a high-frequency vibration control structure system composed of a microsphere cavity and an inertial mass block.

[0031] Figure 2 This is a flowchart of the fabrication process for the microsphere cavity mass block composite structure;

[0032] Figure 3 These are stress response curves at the fiber coupling points of microsphere cavities in mass blocks and microsphere cavity structures within the frequency range of 90kHz-224kHz.

[0033] Figure 4 These are displacement response curves at the fiber coupling points of the microsphere cavity in the mass block and microsphere cavity structures within the frequency range of 90kHz-224kHz.

[0034] Figure 5 This is a simulation comparison of stress distribution and displacement response of a microsphere cavity composite structure at specific frequency points under high-order coupled vibration modes and low frequencies, with part of the outer shell hidden to better show the internal situation of the microspheres. (a) Stress distribution of the microsphere cavity structure with mass at 224kHz; (b) Displacement distribution of the microsphere cavity structure with mass at 224kHz; (c) Stress distribution of the microsphere cavity structure without mass at 224kHz; (d) Displacement distribution of the microsphere cavity structure with mass but without mass at 224kHz; (e) Displacement distribution of the microsphere cavity structure without mass at 90kHz; (f) Displacement distribution of the microsphere cavity structure with mass at 90kHz.

[0035] Figure 6The stress distribution (a) and displacement distribution (b) of the massless microcavity at its characteristic frequency of 424 kHz are shown. Detailed Implementation

[0036] To better demonstrate the manufacturing method of the present invention and to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0037] In existing microcavity optomechanical systems, the vibration amplitude of the microcavity under high-frequency conditions is often too small to be detected. To address this issue, this embodiment provides an improved microcavity composite structure design. This design integrates a mass block of specific geometric dimensions on the surface of the microspheres, utilizing the mass loading effect to reconstruct the mode shape of the system, significantly improving the displacement amplitude and stress sensitivity of the structure.

[0038] In one specific embodiment, the hollow optical microsphere cavity, the mass block, and the support are arranged along the same axis, and the external sound pressure propagates along the direction of the axis. The mass block (3) and the hollow microsphere cavity resonator (2) are connected by UV-curable optical adhesive. The UV-curable optical adhesive is applied to the upper pole region of the hollow microsphere cavity resonator (2) by dotting, and a rigid connection interface is formed after the adhesive layer cures. By controlling the size of the dispensing needle, the amount of adhesive, and the extent of adhesive layer expansion before UV curing, the area ratio is kept within the range of 1% to 5%.

[0039] To facilitate the explanation of the modulating effect of the mass block structure on the mechanical response of the microsphere cavity in this embodiment, the sensitive structure composed of the hollow optical microsphere cavity and the mass block can be equivalently represented as a single-degree-of-freedom mass-spring-damped system, and its equivalent equation of motion can be expressed as:

[0040] (1)

[0041] In the formula, m eff For the equivalent mass of the sensitive structure, c eff k is the equivalent damping coefficient. eff Let F be the equivalent stiffness, x be the equivalent displacement of the characteristic position of the mass block or microsphere cavity along the direction of sound pressure propagation, and F be the equivalent stiffness. ac (t) The equivalent excitation force generated by the sound pressure.

[0042] When the incident sound pressure is a simple harmonic sound pressure p(t) = p0sin(ωt), the equivalent excitation force generated by the sound pressure can be expressed as:

[0043] (2)

[0044] In the formula, p0 is the incident sound pressure amplitude, and Aeff Let f be the equivalent pressure area along the direction of sound pressure propagation, ω be the angular frequency, and f be the sound pressure frequency.

[0045] From equations (1) and (2), it can be obtained that, under steady-state conditions in the frequency domain, the displacement amplitude of the sensitive structure can be expressed as:

[0046] (3)

[0047] Equation (3) shows that when the sound pressure amplitude is constant, the displacement response of the sensitive structure is related to the equivalent mass, equivalent stiffness, equivalent damping, and sound pressure frequency. By setting a mass block, the equivalent mass m of the sensitive structure can be changed. eff This allows for the adjustment of its amplitude-frequency response characteristics.

[0048] This invention provides a high-frequency vibration control structure combining a microsphere cavity and an inertial mass block, suitable for applications requiring extremely high precision measurement of minute vibrations or forces, comprising:

[0049] Figure 1 As shown, the end of the microsphere resonator (6) furthest from the microsphere cavity is fixed to the fixed plate (4), and the top of the other end of the microsphere cavity (2) is connected to a mass block (3). A tapered optical fiber (14) is placed in the equatorial region of the microsphere cavity (2) for optical coupling. At the same time, a laser rangefinder (13) is placed on top of the mass block (3) using a three-dimensional platform (12), and the displacement of the mass block under a sound pressure of 1 Pa is measured by this method.

[0050] To further verify the mechanical response characteristics of this structure under high-frequency excitation, those skilled in the art can build an experimental testing platform. On the one hand, the vibration displacement amplitude of the mass block (3) is measured using laser interferometry; on the other hand, micro-resistance strain gauges are arranged at the connection interface between the mass block (3) and the microsphere cavity (2), or digital image correlation is used to monitor and record the local strain evolution data in real time. The central axes of the fiber cantilever beam (1), the microsphere cavity (2), and the mass block (3) are basically coincident. The plane acoustic wave propagates along the direction from the mass block (3) to the fiber cantilever beam (1), thereby causing the mass block (3) and the microsphere cavity (2) to form an axially coupled mechanical response. The expected experimental results will be consistent with the stress concentration trend and displacement amplification effect obtained from the finite element simulation.

[0051] Figure 2 The diagram shown illustrates the steps of this experiment, including:

[0052] a. Place one end of the hollow optical fiber (5) between two electrodes (6) in the optical fiber fusion splicer, and melt one end of the optical fiber by applying an electric arc through the electrodes (6).

[0053] b. Place the hollow optical fiber (5) at one end of the two electrodes (6) in the optical fiber fusion splicer. When the electric arc applied by the electrode (6) enters the molten state, pressurize it using a syringe (8). In one specific embodiment, a microsphere with an outer diameter of 200 μm, an inner diameter of 190 μm, and a thickness of 10 μm is formed on one side of the microsphere cavity prepared by this method.

[0054] c. Fix the other end of the hollow optical fiber (5) to a fixed plate (4) on the experimental platform to ensure that the fixed end of the optical fiber will not be displaced during the test.

[0055] d. After fixing one end of the non-microsphere cavity of the optical fiber, a small mass block with a radius of 225μm and a height of 20μm is attached to the equatorial surface of the microsphere cavity (2) away from the end of the optical fiber using UV-curable optical adhesive.

[0056] To verify the debugging effect of the mass block on the microsphere cavity vibration module in this example, and to analyze its stress response and displacement amplitude at a specific frequency, a three-dimensional acoustic-structure interaction model was established using finite element simulation software. In this model, a sphere with a handle length of 0.3 mm, a radius of 220 μm, and a thickness of 10 μm was set. A cylinder with a radius of 225 μm and a height of 20 μm was created on the equatorial plane of the end of the sphere furthest from the optical fiber and placed in contact with the microsphere cavity. Then, in the material configuration interface, the optical fiber handle and the microsphere cavity were set to silicon dioxide crystal, and the cuboid was set to steel.

[0057] Tetrahedral meshing was used in the mesh generation process, with mesh refinement applied at the connection between the microsphere and the optical fiber to ensure the accuracy of stress calculations. Next, a fixed constraint was placed at the end of the optical fiber furthest from the microsphere to simulate its fixation on a fixed plate. Simultaneously, a plane wave radiation boundary condition was applied directly above the microsphere, radiating a 1 Pa acoustic wave towards the entire system structure. It is important to note that the entire system is enveloped by a perfectly matched layer, meaning there is no reflected wave influence. Furthermore, a continuity setting was added at the contact point between the microsphere cavity and the mass block, selecting a consistent boundary pair with a frequency range of 90 kHz to 224 kHz.

[0058] Within the specified frequency range, the harmonic steady-state response of the composite structure is calculated. The undamped natural angular frequency of the sensitive structure can be expressed as:

[0059] (4)

[0060] The corresponding natural frequency is:

[0061] (5)

[0062] In the formula, f nk is the equivalent resonant frequency of the composite structure. eff For the equivalent stiffness under the corresponding vibration mode, m eff The mass is the equivalent mass under the corresponding vibration mode. Equation (5) shows that, under the condition of constant equivalent stiffness, increasing the mass of the mass block can reduce the natural frequency of the sensitive structure, causing its mechanical response frequency band to shift to a lower frequency; by adjusting the material, diameter, thickness and connection dimensions of the mass block, the target mechanical resonance frequency can be controlled. The introduction of the mass block increases the equivalent mass of the system on the one hand, and on the other hand, it constrains the local deformation of the microsphere cavity through the rigid connection interface, thereby improving the equivalent stiffness of the system. When the relative increase in equivalent stiffness is greater than the relative increase in equivalent mass, the resonance frequency of the composite structure will shift to a higher frequency direction.

[0063] Furthermore, we introduce the damping ratio:

[0064] (6)

[0065] When the damping ratio is small, the resonant frequency of the sensitive structure can be approximated as:

[0066] (7)

[0067] In the formula, f r This represents the resonant frequency at which the displacement amplitude of the structure reaches its peak in the frequency response. Therefore, it can be seen that the mass block can not only change the natural frequency of the structure, but also influence its resonant response peak and operating frequency band in combination with its damping characteristics.

[0068] like Figure 5 As shown, Figure 5 (a) Von Mises stress distribution of the structure at 224 kHz with mass blocks installed. Figure 5 (b) shows the displacement amplitude distribution under the same conditions. Figure 5 (a) It can be seen that the structural stress is mainly concentrated in the transition area between the mass block and the top of the microsphere cavity, and there is also some stress concentration at the connection between the microsphere cavity and the lower support. The stress response reaches 10. 5 The Pa level indicates that the mass block exerted a significant mechanical load on the microsphere cavity under axial sound pressure.

[0069] Depend on Figure 5 (b) It can be seen that under 224kHz sound pressure excitation, the mass block and the upper region of the adjacent microsphere cavity exhibit a relatively significant displacement response, and the spherical wall of the microsphere cavity also undergoes corresponding elastic deformation along with the mass block. The maximum displacement of this structure reaches 10. -4 The μm-scale indicates that, near this frequency, acoustic pressure excitation can effectively excite the target mechanical modes of the mass block composite microsphere cavity structure.

[0070] Figure 5 (c) Von Mises stress distribution of the hollow optical microsphere cavity at 224 kHz without a mass block. Figure 5 (c) shows the displacement amplitude distribution under the same conditions. Figure 5 (c) It can be seen that without the mass block, the stress is mainly concentrated in the connection area between the microsphere cavity and the support, and the maximum stress is only 10. 2 Pa level. Figure 5 (d) It can be seen that although the microsphere cavity exhibits a certain overall deformation trend, the displacement amplitude is only 10. -8 The μm scale indicates that the massless structure has a weak mechanical response at 224 kHz.

[0071] right Figure 5 (a) Figure 5 (b) and Figure 5 (c) Figure 5 (d) Comparison shows that, under the same incident sound pressure amplitude and the same excitation frequency, the stress response of the structure after adding the mass block is reduced from 10... 2 The Pa level increased to 10 5 Pa level, displacement response from 10 -8 The μm scale has been increased to 10 -4 The results show that the mass block can change the equivalent mass and mechanical natural frequency of the microsphere cavity structure, thereby adjusting the target mechanical resonant frequency of the mass composite structure to around 224 kHz, resulting in a significant enhancement of the resonant response at this target frequency.

[0072] Figure 6 The distribution of stress (a) and displacement (b) at the characteristic frequency of the microsphere cavity without a mass block shows that the target natural frequency of the microsphere cavity without a mass block in this design is 424kHz. Therefore, it is in a non-resonant working state under 224kHz excitation, and the displacement and stress response are relatively small. After adding a mass block, the target natural frequency is reduced to about 224kHz, so that the incident sound pressure frequency matches the mechanical resonance frequency of the structure, thereby significantly enhancing the elastic deformation of the microsphere cavity.

[0073] This embodiment introduces a high-density mass block, utilizing its inertial anchoring effect to significantly enhance the amplitude of the microsphere cavity under high-frequency excitation, while also increasing the stress experienced by the microsphere cavity. Simulation and experimental results show that the mass block in this embodiment mainly achieves narrowband response enhancement within the target frequency band through mechanical resonance frequency modulation, rather than significantly amplifying the structural response across the entire frequency range. The increased displacement and stress of the microsphere cavity can further induce changes in the effective radius and refractive index of the material, providing a larger mechanical response for the conversion of acoustic pressure signals into changes in optical resonance parameters.

[0074] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-frequency vibration control structure composed of a microsphere cavity and an inertial mass block, characterized by: A microsphere cavity composite resonator, wherein the microsphere cavity resonator is a hollow thin-walled sphere structure; At least one mass block is fixed to the pole of the microsphere resonator away from the optical fiber end by a dot-coating adhesion method, and forms a rigid contact interface with the microsphere resonator; wherein, the mass block mass and the equivalent stiffness of the microsphere structure are set so that the resonant frequency of the high-frequency vibration control structure is 90kHz~224kHz; by attaching the mass block to the pole position of the microsphere, the at least one mass block is fixedly connected to a preset vibration deformation sensitive area on the outer surface of the microsphere resonator, the preset vibration deformation sensitive area being the region where the microsphere resonator undergoes the maximum mechanical deformation at the target frequency; A rigid connection interface is formed between the mass block and the outer surface of the pole of the microspherical cavity resonator. The contact area of ​​the rigid connection interface is within a preset proportion of the total theoretical contact area between the mass block and the microspherical cavity resonator, so that the mechanical stress is concentrated at the rigid connection interface.

2. The high-frequency vibration control structure according to claim 1, characterized in that: Under excitation at a frequency of 224 kHz and a sound pressure of 1 Pa, the maximum displacement amplitude on the surface of the microsphere resonator is on the order of 10−4 μm. This displacement magnitude is determined by a specific mass-stiffness ratio and resonant frequency matching relationship, and the stress concentration factor at the rigid connection interface is higher than the stress level in other areas of the microsphere cavity.

3. A method for constructing a high-frequency vibration modulation structure as described in any one of claims 1-2, characterized by the following points: A microsphere with a hollow structure and a wall thickness on the micrometer scale is fabricated at the end of an optical fiber; a mass block with a specific size is prefabricated to achieve stress concentration distribution; a rigid interface and stress distribution effect are ensured by using a specific curing temperature adhesive curve, dotting method and alignment process; the ratio of the contact area of ​​the rigid connection interface to the bottom area of ​​the mass block is in the range of 1% to 5%.

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