A kind of air pressure monitoring device and method based on microbubble optical microcavity air pressure probe

Abstract

The present application relates to a kind of gas pressure monitoring device and method based on microbubble optical microcavity air pressure probe, wherein device includes: sensing system includes laser, injection locking module, microbubble optical microcavity air pressure probe module and photoelectric detector;Laser is used to emit laser;Injection locking module is used to receive modulation signal to carry out intensity modulation to laser, obtains laser locking signal;Microbubble optical microcavity air pressure probe module is used to receive laser locking signal, and vibration mode locking is carried out based on laser locking signal, exports laser locking signal under locked vibration mode;Photoelectric detector is used to convert laser locking signal under locked vibration mode into electrical signal;Measuring system includes function generator, lock-in amplifier and frequency spectrometer;Function generator is used to generate modulation signal;Lock-in amplifier is used to calculate steady-state phase difference, to characterize the change amount of external air pressure;Frequency spectrometer is used to monitor spectral feature and locking state.

Description

Technical Field

[0001] This invention relates to the field of air pressure monitoring technology, and mainly to an air pressure monitoring device and method based on a microbubble optical microcavity air pressure probe. Background Technology

[0002] High-sensitivity barometric pressure detection technology is of great significance in fields such as biomedicine, industrial control, aerospace, and environmental monitoring. Its detection accuracy, anti-interference capability, and long-term stability directly affect the operational reliability and data accuracy of related systems. However, as modern technology continues to upgrade its requirements for detecting minute changes in barometric pressure, traditional electronic barometers are no longer able to meet the needs of different scenarios.

[0003] Chinese invention patent application CN110686823A discloses a high-sensitivity piezoelectric barometric pressure sensor and its fabrication method. The pressure sensor in this technical solution comprises, from top to bottom, a barrier layer, a functional layer, and a cavity layer. The barrier layer is an elastic thin film used to protect the functional layer from external corrosion. The functional layer includes a mica film, a piezoelectric film, and electrodes. The mica film serves as the carrier for the piezoelectric film, which is attached to it. The electrodes are disposed on the piezoelectric film to extract the electrical signals generated therefrom. The cavity layer is located below the functional layer, and its base and the functional layer form a sealed cavity. When a pressure difference is created between the external air pressure and the air pressure inside the cavity, the piezoelectric film deforms and converts this deformation into an electrical signal. The electrodes then transmit this electrical signal to the detection device, thereby achieving air pressure detection. However, the core of this technical solution lies in the conversion and transmission from mechanical deformation to an electrical signal, relying on the piezoelectric film to generate the signal and the electrodes to extract it. This monitoring method faces challenges in critical air pressure detection scenarios such as industrial control and aerospace. Strange electromagnetic environments directly interfere with the generation, transmission, and detection of electrical signals, leading to signal distortion, increased measurement errors, and even signal interruption, making it impossible to guarantee the reliability of detection in complex electromagnetic scenarios. Furthermore, the detection methods described above rely on the deformation of the piezoelectric film caused by pressure differences. However, the pressure difference generated by minute pressure changes is extremely small, resulting in weak film deformation. This leads to low signal strength and poor signal-to-noise ratio from the piezoelectric film, making accurate identification difficult. In addition, both elastic and piezoelectric films have poor long-term stability. On one hand, piezoelectric films suffer from mechanical fatigue; after repeated deformation caused by pressure differences over a long period, their piezoelectric coefficient gradually decreases, leading to a decline in electrical signal conversion efficiency. On the other hand, the sealed cavity formed by the cavity layer and functional layer in the above-mentioned technical solutions is susceptible to deterioration in sealing performance due to temperature changes, vibration, and material aging during long-term use. This results in an unstable pressure difference between the cavity and the external air pressure, causing measurement reference drift and making it difficult to guarantee the consistency of long-term continuous detection.

[0004] Therefore, there is an urgent need for a barometric pressure monitoring method that has advantages in resisting electromagnetic interference, high sensitivity, and good long-term stability. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a pressure monitoring device and method based on a microbubble optical microcavity pressure probe.

[0006] The technical solution of the present invention is as follows: On one hand, this invention proposes a pressure monitoring device based on a microbubble optical microcavity pressure probe, the device comprising a sensing system and a measurement system: The sensing system includes a laser, an injection locking module, a microbubble optical microcavity pressure probe module, and a photodetector. A laser is used to emit laser light and transmit it to the injection locking module; The injection locking module is used to receive the modulation signal from the function generator and modulate the intensity of the laser to obtain the laser locking signal. The microbubble optical microcavity pressure probe module is used to receive laser locking signals, perform vibration mode locking based on laser locking signals, and output laser locking signals in the locked vibration mode. A photodetector is used to convert the laser locking signal in the locking vibration mode into an electrical signal; The measurement system includes a function generator, a lock-in amplifier, and a spectrum analyzer; A function generator is used to generate modulated signals and transmit them to the injection lock module; A lock-in amplifier is used to calculate the steady-state phase difference between an electrical signal and a modulation signal, and to characterize changes in external air pressure. A spectrum analyzer is used to monitor the spectral characteristics of a measurement system and the lock-up status of a microbubble optical microcavity pressure probe module.

[0007] Preferably, the injection locking module includes an optical fiber polarizer, an MZ intensity modulator, and a DC power supply, wherein: The fiber polarizer is located between the laser and the MZ intensity modulator and is used to adjust the polarization state of the laser incident on the MZ intensity modulator. The MZ intensity modulator is used to modulate the intensity of the laser to obtain a laser locking signal; The DC power supply is connected to the MZ intensity modulator and is used to provide a bias voltage to the MZ intensity modulator.

[0008] Preferably, the microbubble optical microcavity pressure probe module includes a microbubble optical microcavity pressure probe, a tapered optical fiber, and an adjustable optical attenuator, wherein: The tapered optical fiber is used to couple the laser locking signal into the microbubble optical microcavity pressure probe in the form of an evanescent field. The adjustable optical attenuator is located between the tapered optical fiber and the photodetector and is used to adjust the optical power of the signal input to the photodetector.

[0009] Preferably, the measurement system further includes an oscilloscope connected to the photodetector and the output of the lock-in amplifier, the oscilloscope being used to monitor the electrical signal waveform and the voltage signal of the steady-state phase difference in real time.

[0010] Preferably, the measurement system further includes a controller connected to the output of the lock-in amplifier, the controller being used to process the steady-state phase difference and perform air pressure calibration conversion.

[0011] On the other hand, the present invention also provides a method for monitoring air pressure based on a microbubble optical microcavity air pressure probe, employing the apparatus as described in any embodiment, the method comprising: When the air pressure of the environment where the microbubble optical microcavity pressure probe is located changes, the function generator outputs a modulation signal whose mechanical resonant frequency difference with the microbubble optical microcavity pressure probe is within a preset range. The modulation signal drives the MZ intensity modulator to modulate the laser emitted by the laser and generate a laser locking signal. A laser locking signal is injected into a microbubble optical cavity pneumatic probe through a tapered optical fiber. When the frequency of the laser locking signal matches the inherent mechanical resonant frequency of the microbubble optical cavity pneumatic probe, the current mechanical vibration mode of the microbubble optical cavity pneumatic probe is locked, and the laser signal in the current vibration mode is output. The laser signal is converted into an electrical signal using a photodetector. The steady-state phase difference between the electrical signal and the modulation signal is calculated using a lock-in amplifier. The change in external air pressure is determined based on the steady-state phase difference, and the monitoring results are obtained.

[0012] Preferably, the laser is a tunable semiconductor laser with an output wavelength in the 1550 nanometer band.

[0013] Preferably, the laser emitted by the laser also includes light that has undergone polarization control via an optical fiber polarizer between the laser and the MZ intensity modulator.

[0014] In another aspect, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method described in the present invention.

[0015] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the method described in the present invention.

[0016] The present invention has the following beneficial effects: 1. This invention mainly consists of two parts: a sensing system and a measurement system. The sensing system converts changes in air pressure into changes in phase difference through the optomechanical effect in the microbubble optical microcavity. The microbubble optical microcavity adopts a thin-walled structure, possesses an ultra-high quality factor, exhibits significant optomechanical effects, and is highly sensitive to mechanical responses to changes in air pressure. The injection locking mechanism generates a laser locking signal through an MZ intensity modulator, matches the laser locking signal frequency with the inherent mechanical resonant frequency of the microcavity, amplifies the minute frequency shift that is difficult to measure, and converts it into a steady-state phase difference that is easy to detect with high precision. The lock-in amplifier of the measurement system accurately demodulates the steady-state phase difference between the electrical signal and the reference signal, and the phase difference is linearly related to changes in air pressure. Since the optical signal is naturally unaffected by electric or magnetic fields, electromagnetic interference is isolated from the source of the transmission link, achieving high-sensitivity, electromagnetic interference-resistant air pressure measurement, enhancing the measurement reliability in complex electromagnetic environments, improving the adaptability to harsh working conditions, and ensuring the stability and authenticity of the measurement data. 2. The injection locking module of this invention continuously locks the mechanical vibration mode of the microbubble optical cavity through the modulation signal generated by the function generator, suppressing the drift of the resonant frequency of the microbubble optical cavity caused by external factors such as temperature fluctuations and environmental vibrations, and locking the mechanical vibration mode into a stable state strictly controlled by external signals; it solves the problems of easy resonant frequency drift and large long-term measurement error in traditional microcavity air pressure detection technology, ensures the consistency of long-term continuous detection, and improves the accuracy and repeatability of continuous measurement. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the device according to an embodiment of the present invention. Detailed Implementation

[0018] 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, and 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.

[0019] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0020] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0022] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0023] Example 1: See Figure 1 This invention provides a pressure monitoring device based on a microbubble optical microcavity pressure probe, the device comprising a sensing system and a measurement system: The sensing system includes a laser, an injection locking module, a microbubble optical microcavity pressure probe module, and a photodetector. A laser is used to emit laser light and transmit it to the injection locking module; The injection locking module is used to receive the modulation signal from the function generator and modulate the intensity of the laser to obtain the laser locking signal. The microbubble optical microcavity pressure probe module is used to receive laser locking signals, perform vibration mode locking based on laser locking signals, and output laser locking signals in the locked vibration mode. A photodetector is used to convert the laser locking signal in the locking vibration mode into an electrical signal; The measurement system includes a function generator, a lock-in amplifier, and a spectrum analyzer; A function generator is used to generate modulated signals and transmit them to the injection lock module; A lock-in amplifier is used to calculate the steady-state phase difference between an electrical signal and a modulation signal, and to characterize changes in external air pressure. A spectrum analyzer is used to monitor the spectral characteristics of a measurement system and the lock-up status of a microbubble optical microcavity pressure probe module.

[0024] Preferably, the injection locking module includes an optical fiber polarizer, an MZ intensity modulator, and a DC power supply, wherein: The fiber polarizer is located between the laser and the MZ intensity modulator and is used to adjust the polarization state of the laser incident on the MZ intensity modulator. The MZ intensity modulator is used to modulate the intensity of the laser to obtain a laser locking signal; The DC power supply is connected to the MZ intensity modulator to provide a bias voltage to the MZ intensity modulator, so that it operates in the linear range near the half-wave voltage point, thereby achieving the best intensity modulation efficiency and reducing the electrical noise of the MZ intensity modulator.

[0025] Preferably, the microbubble optical microcavity pressure probe module includes a microbubble optical microcavity pressure probe, a tapered optical fiber, and an adjustable optical attenuator, wherein: The tapered fiber described above is used to couple the laser locking signal into the microbubble optical microcavity pressure probe in the form of an evanescent field; The adjustable optical attenuator is connected to a tapered optical fiber at its left end and to a photodetector at its right end, and is used to adjust the optical power of the signal input to the photodetector.

[0026] Preferably, the measurement system further includes an oscilloscope connected to the photodetector and the output of the lock-in amplifier, the oscilloscope being used to monitor the electrical signal waveform and the voltage signal of the steady-state phase difference in real time.

[0027] Preferably, the measurement system further includes a controller connected to the output of the lock-in amplifier, the controller being used to process the steady-state phase difference and perform air pressure calibration conversion.

[0028] Example 2: This embodiment provides a method for monitoring air pressure based on a microbubble optical microcavity air pressure probe, the method comprising: S1. When the air pressure of the environment where the microbubble optical microcavity pressure probe is located changes, the function generator outputs a modulation signal with the mechanical resonant frequency difference between the microbubble optical microcavity pressure probe and the probe within a preset range. The modulation signal drives the MZ intensity modulator to modulate the laser emitted by the laser and generate a laser locking signal. The laser is a tunable semiconductor laser with an output wavelength in the 1550 nanometer band. The laser emitted by the laser also includes light that passes between the laser and the MZ intensity modulator and is polarized by an optical fiber polarizer. S2. The laser locking signal is injected into the microbubble optical cavity gas pressure probe through a tapered optical fiber. When the frequency of the laser locking signal matches the inherent mechanical resonant frequency of the microbubble optical cavity gas pressure probe, the current mechanical vibration mode of the microbubble optical cavity gas pressure probe is locked, and the laser signal in the current vibration mode is output. The laser signal is converted into an electrical signal using a photodetector. The microbubble optical microcavity pressure probe is a hollow, thin silica microbubble at the micrometer level. Micro-pressure channels can be connected to the front and back of the microbubble. Its advantage is that it can be extended a distance using a probe with a matching size flexible tube. This eliminates the need for the microbubble to directly contact the pressure source, enabling long-distance micro-pressure sensing and effectively avoiding the influence of other external factors on the microbubble. As a mechanical oscillator, it has one or more inherent mechanical resonant frequencies, similar to a tuning fork. When the laser circulates within the cavity, the optical force (radiation pressure) excites the microbubble to undergo tiny periodic deformation vibrations, which is the mechanical mode. The target is the frequency and phase of this mechanical vibration, so that it changes from a free-running, easily disturbed state to a stable state that is strictly controlled by external commands. The specific function generator produces a frequency of The modulation signal drives the MZ intensity modulator to modulate the intensity of the continuous laser, generating a laser locking signal. In addition to the original laser frequency, the laser locking signal also generates two symmetrical signals with frequencies of [missing information]. The sideband light, among which The frequency of the laser; When the frequency of one of the sideband lights happens to match the mechanical resonant frequency of the microbubble optical microcavity pressure probe... When matched or very close, this sideband light efficiently and continuously injects energy into the mechanical vibrations of the microbubble cavity through the photomechanical effect; if externally injected... close enough The entire mechanical vibration system will then abandon its slightly drifted natural frequency and be locked to the externally injected frequency. Above, and maintain a fixed phase relationship with it; Once the mechanical vibration mode is locked... It is equal to It maintains a steady-state phase difference with the external air pressure; when the external air pressure changes, the stress of the microbubble optical microcavity pressure probe changes. There is a slight tendency to shift. To maintain the locked state, the system will automatically adjust, which manifests as a significant, linear change in the steady-state phase difference. The above process amplifies and converts minute frequency shifts that are difficult to measure into phase difference changes that are easy to measure with high precision, thus achieving ultra-high sensitivity detection of minute air pressure changes. S3. Calculate the steady-state phase difference between the electrical signal and the modulation signal using a lock-in amplifier; S4. Determine the change in external air pressure based on the steady-state phase difference to obtain the monitoring results; In the injected locked state, the detuning amount between the steady-state phase difference measured by the lock-in amplifier and the radio frequency of the function generator and the mechanical resonant frequency of the microbubble optical microcavity pressure probe. Linear relationship ,in, This indicates that the lock-in amplifier calculates the steady-state phase difference between the electrical signal and the reference signal. This represents the initial steady-state phase difference. This represents the phase difference-frequency detuning response coefficient of the system; Therefore, the method for calculating the change in external air pressure is as follows: ; In the formula, This indicates the change in external air pressure; The barometric pressure sensitivity coefficient represents the preset mechanical frequency. After each measurement is completed, the system remains locked and can continue to monitor in real time. If it is necessary to change the measurement point or recalibrate, the modulation signal of the function generator can be turned on again for remeasurement.

[0029] Example 3: This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements a pressure monitoring method based on a microbubble optical microcavity pressure probe as described in any one of Embodiment 1.

[0030] Example 4: This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a pressure monitoring method based on a microbubble optical microcavity pressure probe as described in any one of Embodiment 1.

[0031] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0032] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0033] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0034] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0035] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A pressure monitoring device based on a microbubble optical microcavity pressure probe, characterized in that, The device includes a sensing system and a measurement system: The sensing system includes a laser, an injection locking module, a microbubble optical microcavity pressure probe module, and a photodetector. A laser is used to emit laser light and transmit it to the injection locking module; The injection locking module is used to receive the modulation signal from the function generator and modulate the intensity of the laser to obtain the laser locking signal. The microbubble optical microcavity pressure probe module is used to receive laser locking signals, perform vibration mode locking based on laser locking signals, and output laser locking signals in the locked vibration mode. A photodetector is used to convert the laser locking signal in the locking vibration mode into an electrical signal; The measurement system includes a function generator, a lock-in amplifier, and a spectrum analyzer; A function generator is used to generate modulated signals and transmit them to the injection lock module; A lock-in amplifier is used to calculate the steady-state phase difference between an electrical signal and a modulation signal, and to characterize changes in external air pressure. A spectrum analyzer is used to monitor the spectral characteristics of a measurement system and the lock-up status of a microbubble optical microcavity pressure probe module.

2. The air pressure monitoring device based on a microbubble optical microcavity air pressure probe according to claim 1, characterized in that, The injection locking module includes an optical fiber polarizer, an MZ intensity modulator, and a DC power supply, wherein: The fiber polarizer is located between the laser and the MZ intensity modulator and is used to adjust the polarization state of the laser incident on the MZ intensity modulator. The MZ intensity modulator is used to modulate the intensity of the laser to obtain a laser locking signal; The DC power supply is connected to the MZ intensity modulator and is used to provide a bias voltage to the MZ intensity modulator.

3. The air pressure monitoring device based on a microbubble optical microcavity air pressure probe according to claim 1, characterized in that, The microbubble optical microcavity pressure probe module includes a microbubble optical microcavity pressure probe, a tapered optical fiber, and an adjustable optical attenuator, wherein: The tapered optical fiber is used to couple the laser locking signal into the microbubble optical microcavity pressure probe in the form of an evanescent field. The adjustable optical attenuator is located between the tapered optical fiber and the photodetector and is used to adjust the optical power of the signal input to the photodetector.

4. The air pressure monitoring device based on a microbubble optical microcavity air pressure probe according to claim 1, characterized in that, The measurement system also includes an oscilloscope connected to the output of a photodetector and a lock-in amplifier. The oscilloscope is used to monitor the electrical signal waveform and the voltage signal of the steady-state phase difference in real time.

5. A pressure monitoring device based on a microbubble optical microcavity pressure probe according to claim 1, characterized in that, The measurement system also includes a controller connected to the output of the lock-in amplifier, which is used to process the steady-state phase difference and perform air pressure calibration conversion.

6. A method for monitoring air pressure based on a microbubble optical microcavity air pressure probe, employing the device described in any one of claims 1-5, characterized in that, The method includes: When the air pressure of the environment where the microbubble optical microcavity pressure probe is located changes, the function generator outputs a modulation signal whose mechanical resonant frequency difference with the microbubble optical microcavity pressure probe is within a preset range. The modulation signal drives the MZ intensity modulator to modulate the laser emitted by the laser and generate a laser locking signal. A laser locking signal is injected into a microbubble optical cavity pneumatic probe through a tapered optical fiber. When the frequency of the laser locking signal matches the inherent mechanical resonant frequency of the microbubble optical cavity pneumatic probe, the current mechanical vibration mode of the microbubble optical cavity pneumatic probe is locked, and the laser signal in the current vibration mode is output. The laser signal is converted into an electrical signal using a photodetector. The steady-state phase difference between the electrical signal and the modulation signal is calculated using a lock-in amplifier. The change in external air pressure is determined based on the steady-state phase difference, and the monitoring results are obtained.

7. The method for monitoring air pressure based on a microbubble optical microcavity air pressure probe according to claim 6, characterized in that, The laser is a tunable semiconductor laser with an output wavelength in the 1550 nanometer band.

8. A method for monitoring air pressure based on a microbubble optical microcavity air pressure probe according to claim 6, characterized in that, The laser emitted by the laser also includes light that passes between the laser and the MZ intensity modulator and is polarized by an optical fiber polarizer.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 6 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 6 to 8.

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