A method and system for detecting photoacoustic spectroscopy with laser wavelength deviation detection

Abstract

The application relates to a photoacoustic spectrum detection method and system with laser wavelength deviation detection, and the method comprises the following steps: calibrating a Fabry-Perot etalon; controlling the cavity temperature of the calibrated Fabry-Perot etalon through double-loop temperature control and a PID control algorithm until the cavity temperature change reaches a threshold value within a preset time; coupling the Fabry-Perot etalon with completed temperature control with a photoacoustic signal source; detecting and collecting a photoacoustic signal through a photoelectric detector, and denoising the photoacoustic signal through a second-harmonic wavelength modulation method; and reconstructing the denoised photoacoustic signal based on compressed sensing and a two-step iterative shrinkage method. Through the combination of temperature control, wavelength tuning and the compressed sensing method, the application reduces the noise of the photoacoustic signal and improves the accuracy and sensitivity of photoacoustic signal detection.

Description

Technical Field

[0001] This invention belongs to the field of spectral detection technology, specifically relating to a photoacoustic spectral detection method and system with laser wavelength deviation detection. Background Technology

[0002] In photoacoustic spectroscopy, accurate detection of the laser wavelength and high-sensitivity detection of the photoacoustic signal are crucial for achieving high-precision measurements. However, traditional photoacoustic spectroscopy techniques often suffer from measurement errors and signal noise when faced with laser wavelength deviations and changes in ambient temperature, thus affecting the accuracy and stability of the detection. Summary of the Invention

[0003] To improve the accuracy and stability of photoacoustic spectroscopy detection, a method for photoacoustic spectroscopy detection with laser wavelength deviation detection is provided in the first aspect of the present invention. The method includes: calibrating a Fabry-Perot etalon based on a standard light source with multiple wavelengths of the target laser; controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time; coupling the temperature-controlled Fabry-Perot etalon to a wavelength-tunable laser source, and then irradiating the photoacoustic cell using the laser source; detecting and acquiring the photoacoustic signal using a photodetector, and denoising the photoacoustic signal using a second harmonic wavelength modulation method; and reconstructing the denoised photoacoustic signal based on compressed sensing and a two-step iterative contraction method.

[0004] In some embodiments of the present invention, controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time includes: installing a thermoelectric cooler and a temperature sensor at multiple locations within the Fabry-Perot etalon cavity to detect the cavity temperature in real time; controlling the thermal measurement temperature of the thermoelectric cooler using an outer-loop PID controller, and after the thermal measurement temperature stabilizes, controlling the cold measurement temperature of the thermoelectric cooler to stabilize using an inner-loop PID controller; setting the cavity temperature of the Fabry-Perot etalon, and controlling the cavity temperature of the calibrated Fabry-Perot etalon using the stabilized outer-loop PID controller and inner-loop PID controller until the cavity temperature change reaches a threshold within a preset time.

[0005] Furthermore, the control method of the outer loop PID controller is expressed as follows:

[0006] ,

[0007] u(t) This indicates the controller output adjustable voltage; e(t) Indicates temperature error. K p 、K i 、K d These represent proportional gain, integral gain, and derivative gain, respectively.

[0008] In some embodiments of the present invention, the method of denoising the photoacoustic signal by second harmonic wavelength modulation includes: synchronously detecting the phase difference between the photoacoustic signal and the reference signal by a lock-in amplifier, and extracting the second harmonic component of the photoacoustic signal; calculating the intensity and distribution of the photoacoustic signal based on the amplitude and phase changes of the second harmonic component; and denoising the photoacoustic signal based on the intensity and distribution of the photoacoustic signal.

[0009] In some embodiments of the present invention, the reconstruction of the denoised photoacoustic signal based on compressed sensing and a two-step iterative shrinkage method includes: reconstructing the initial pressure distribution of the photoacoustic signal from sparse measurement data using compressed sensing; and updating and iterating the initial pressure distribution using a two-step iterative shrinkage method until the soft threshold difference between adjacent iterative signals is lower than a preset value.

[0010] Furthermore, the soft threshold is calculated through the following steps:

[0011] ,

[0012] in T Indicates soft threshold ,l Indicates the threshold parameter. x This represents a photoacoustic signal, and sign(x) represents the sign function.

[0013] A second aspect of the present invention provides a photoacoustic spectroscopy detection system with laser wavelength deviation detection, comprising: a calibration module for calibrating a Fabry-Perot etalon based on a standard light source with multiple wavelengths of a target laser; a control module for controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time; a coupling module for coupling the temperature-controlled Fabry-Perot etalon to a wavelength-tunable laser source, and then irradiating the photoacoustic cell using the laser source; a denoising module for detecting and acquiring photoacoustic signals using a photodetector, and denoising the photoacoustic signals using a second harmonic wavelength modulation method; and a reconstruction module for reconstructing the denoised photoacoustic signals based on compressed sensing and a two-step iterative contraction method.

[0014] A third aspect of the present invention provides an electronic device comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the photoacoustic spectrum detection method with laser wavelength deviation detection provided in the first aspect of the present invention.

[0015] In a fourth aspect, the present invention provides a computer-readable medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the photoacoustic spectrum detection method with laser wavelength deviation detection provided in the first aspect of the present invention.

[0016] The beneficial effects of this invention are:

[0017] This invention relates to a photoacoustic spectrum detection method with laser wavelength deviation detection, comprising: calibrating a Fabry-Perot etalon; controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time; coupling the temperature-controlled Fabry-Perot etalon to a photoacoustic signal source; detecting and acquiring the photoacoustic signal using a photodetector, and denoising the photoacoustic signal using a second harmonic wavelength modulation method; and reconstructing the denoised photoacoustic signal based on compressed sensing and a two-step iterative contraction method.

[0018] It is evident that the present invention has the following beneficial effects:

[0019] 1. A dual-ring temperature control system and a multi-layer thermal insulation structure are employed to achieve high thermal stability of the Fabry-Perot interferometer. A PID control algorithm is used to adjust the temperature in real time, ensuring the interferometer's stability under various environmental conditions.

[0020] 2. By combining a silicon cantilever sensor with second harmonic wavelength modulation (2f-WMS) technology, the sensitivity and signal-to-noise ratio of the photoacoustic signal are significantly improved. Furthermore, the precision and accuracy of detection are enhanced through compressed sensing reconstruction. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the basic process of a photoacoustic spectrum detection method with laser wavelength deviation detection in some embodiments of the present invention;

[0022] Figure 2 This is a schematic diagram illustrating the specific process of a photoacoustic spectrum detection method with laser wavelength deviation detection in some embodiments of the present invention;

[0023] Figure 3This is a schematic diagram of the structure of a photoacoustic spectrum detection system with laser wavelength deviation detection in some embodiments of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of an electronic device in some embodiments of the present invention. Detailed Implementation

[0025] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0026] refer to Figure 1 and Figure 2 In a first aspect of the present invention, a method for detecting photoacoustic spectra with laser wavelength deviation detection is provided, comprising: S100. calibrating a Fabry-Perot etalon based on a standard light source with multiple wavelengths of a target laser; S200. controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time; S300. coupling the temperature-controlled Fabry-Perot etalon to a wavelength-tunable laser source, and then irradiating a photoacoustic cell using the laser source; S400. detecting and acquiring photoacoustic signals using a photodetector, and denoising the photoacoustic signals using a second harmonic wavelength modulation method; S500. reconstructing the denoised photoacoustic signals based on compressed sensing and a two-step iterative contraction method.

[0027] In step S100 of some embodiments of the present invention, the Fabry-Perot etalon is calibrated based on a standard light source with multiple wavelengths of the target laser. Specifically, calibration is performed using a standard light source with a known wavelength to ensure the accuracy of the system measurements; the repeatability and stability of the system are verified by measuring lasers of different wavelengths multiple times.

[0028] It is understandable that the cavity temperature of the Fabry-Perot etalon has a significant impact on its measurement accuracy. Temperature changes lead to variations in cavity length, thus affecting the accuracy of wavelength measurements. To ensure the stability of the Fabry-Perot etalon under different environmental conditions, a dual-loop temperature control system and a PID control algorithm are required to achieve precise control of the cavity temperature.

[0029] Therefore, in step S200 of some embodiments of the present invention, controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time includes:

[0030] S201. Install the thermoelectric cooler and temperature sensor at multiple locations within the Fabry-Perot etalon cavity to monitor the cavity temperature in real time;

[0031] Specifically, the dual-loop temperature control system comprises two independent control loops: an inner loop and an outer loop. The inner loop controls the cold-side temperature of the thermoelectric cooler (TEC), while the outer loop controls the hot-side temperature of the TEC. A suitable TEC is selected to ensure sufficient cooling and heating capacity to meet the temperature regulation requirements of the Fabry-Perot etalon cavity. High-precision temperature sensors (such as PT100 or NTC thermistors) are installed at key locations within the Fabry-Perot etalon cavity to monitor the cavity temperature in real time. Appropriate PID controllers and TEC drivers are selected to ensure compatibility and efficient operation with the temperature sensors and TEC.

[0032] S202. The thermal temperature of the thermoelectric cooler is controlled by the outer loop PID controller. After the thermal temperature stabilizes, the cold temperature of the thermoelectric cooler is controlled by the inner loop PID controller to achieve a stable temperature.

[0033] S203. Set the cavity temperature of the Fabry-Perot etalon, and control the cavity temperature of the calibrated Fabry-Perot etalon through the stabilized outer loop PID controller and inner loop PID controller until the cavity temperature change reaches a threshold within a preset time.

[0034] Specifically, the proportional, integral, and derivative gain parameters of the PID controller are set through experiments or automatic tuning methods. K p 、K i 、K d This ensures that the system responds quickly and stably.

[0035] Furthermore, the control method of the outer loop PID controller is expressed as follows:

[0036] ,

[0037] u(t) This indicates the controller output adjustable voltage; e(t) Indicates temperature error. K p 、K i 、K d These represent proportional gain, integral gain, and derivative gain, respectively. Similarly, the above control method can also be used to represent the control method of an inner-loop PID controller, which will not be elaborated upon here.

[0038] In step S400 of some embodiments of the present invention, the denoising of the photoacoustic signal by the second harmonic wavelength modulation method includes:

[0039] S401. The phase difference between the photoacoustic signal and the reference signal is synchronously detected by a lock-in amplifier, and the second harmonic component of the photoacoustic signal is extracted.

[0040] Specifically, a wavelength-tunable laser source is used, and the laser wavelength is controlled by modulating the laser drive current. The modulation signal generation formula is: λ(t)=λ 0 +Δλsin(ωt) ,

[0041] in, λ(t) The modulated laser wavelength. l 0 is the center wavelength. Dl ω represents the modulation depth, and ω is the modulation angular frequency. The second harmonic signal is extracted using a digital filter and a fast Fourier transform. A lock-in amplifier (LIA) is used to synchronously detect the phase difference between the input and reference signals. The LIA can selectively amplify signals with the same frequency and phase as the reference signal, thereby extracting the second harmonic component. The reference frequency and phase of the LIA are configured to ensure consistency with the laser wavelength modulation frequency. The gain and time constant of the LIA are adjusted to optimize signal detection performance.

[0042] S402. Calculate the intensity and distribution of the photoacoustic signal based on the amplitude and phase changes of the second harmonic component;

[0043] S403. Based on the intensity and distribution of the photoacoustic signal, denoise the photoacoustic signal. Specifically, based on the obtained intensity and distribution of the photoacoustic signal, set a corresponding filter to denoise the photoacoustic signal.

[0044] It is understandable that the microphone in the photoacoustic cell collects the sound signal, while simultaneously demodulating and processing the light signal measured by the photodetector to ultimately obtain the photoacoustic signal.

[0045] In step S500 of some embodiments of the present invention, the reconstruction of the denoised photoacoustic signal based on compressed sensing and a two-step iterative shrinkage method includes:

[0046] S501. The initial pressure distribution of the photoacoustic signal is reconstructed from sparse measurement data using compressed sensing.

[0047] Specifically, assume that the photoacoustic signal has a sparse representation under some basis or dictionary, meaning that most coefficients are zero or close to zero. Sparse representation can be achieved using discrete cosine transform (DCT), wavelet transform, etc. Construct the measurement matrix. A , indicating from sparse signal x To measurement data y The linear transformation relationship is as follows:

[0048] y=Ax+e, in e Indicates noise.

[0049] S502. The initial pressure distribution is updated and iterated using a two-step iterative shrinkage method until the soft threshold difference between adjacent iterative signals is lower than a preset value.

[0050] Specifically, the TwIST algorithm reconstructs the signal from sparse measurement data through an iterative optimization process. Initialization of the signal... x (0) and x (1) Set threshold parameters l Step size parameter α and β .

[0051] In each iteration, update the signal. x The estimated value:

[0052] ,

[0053] x (k+1) Indicates the first k+ Signal estimate after one iteration; x (k) Indicates the first k The signal estimate for the next iteration; T λ Indicates soft threshold ,l This represents the threshold parameter.

[0054] It should be noted that, x This represents the input signal or data. The input signal can be a scalar, a vector, or a matrix, and it represents the coefficients under a certain basis. x The value can be positive, negative, or zero. λ is a positive number used to determine the degree to which the signal components are compressed. If x The absolute value is less than l ,but x Compressed to zero, this indicates that the component is considered noise or an unimportant signal; if x The absolute value is greater than l ,but x Subtraction l The portion is retained, indicating that this component is considered an important signal element.

[0055] Furthermore, the soft threshold is calculated through the following steps:

[0056] ,

[0057] inT Indicates soft threshold ,l Indicates the threshold parameter. x This represents a photoacoustic signal, and sign(x) represents the sign function. This indicates a compression operation. When |x| ≤ λ|, the output is zero, indicating that signal components smaller than the threshold are completely suppressed. When |x| > λ|, the output is zero. l When |x| - λ| is reached, the output is |x| - λ|, indicating that signal components greater than the threshold are retained, but their amplitude is reduced. l .

[0058] Furthermore, the input signal x The soft threshold function contains noise and uses a threshold. l Soft thresholding removes noise by compressing signal components smaller than a threshold to zero. Through sparse signal representation, the soft thresholding function preserves important signal components while suppressing unimportant ones, resulting in a sparser signal representation that facilitates signal compression and reconstruction. In compressed sensing technology, the soft thresholding function is used for signal reconstruction; by processing sparse signals, it reduces redundant data and improves signal compression efficiency.

[0059] Suppose there is an input signal vector x =[3,1,−2,0.5,−0.1] and threshold parameters l =1, and the result after applying the soft thresholding function is as follows:

[0060] for x =3, calculate sign(3)⋅max(3−1,0)=1⋅2=2;

[0061] for x =1, calculate sign(1)⋅max(1−1,0)=1⋅0=0;

[0062] for x =−2, calculate sign(−2)⋅max(2−1,0)=−1⋅1=−1;

[0063] for x =0.5, calculate sign(0.5)⋅max(0.5−1,0)=1⋅0=0;

[0064] for x =−0.1, calculate sign(−0.1)⋅max(0.1−1,0);

[0065] Therefore, the output signal vector after applying the soft threshold function is [2,0,−1,0,0].

[0066] Finally, the reconstructed photoacoustic signal is analyzed to calculate the reconstruction accuracy and sparsity. The reconstruction effect is evaluated by comparing the reconstructed signal with the original signal.

[0067] Reconstruction accuracy is evaluated using peak signal-to-noise ratio:

[0068] ;

[0069] The sparsity evaluation is expressed as:

[0070] ,

[0071] Sparsity represents the sparsity of the signal; The number of non-zero elements in the signal is represented by ; N represents the total number of elements in the signal.

[0072] It is understandable that the denoised photoacoustic signal is reconstructed using compressed sensing and a two-step iterative shrinking method. This method combines compressed sensing technology with the efficient TwIST algorithm, enabling the reconstruction of high-precision photoacoustic signals from sparse measurement data, thus improving the accuracy and stability of signal reconstruction.

[0073] Example 2

[0074] refer to Figure 3 In a second aspect, the present invention provides a photoacoustic spectral detection system 1 with laser wavelength deviation detection, comprising: a calibration module 11 for calibrating a Fabry-Perot etalon based on a standard light source with multiple wavelengths of a target laser; a control module 12 for controlling the cavity temperature of the calibrated Fabry-Perot etalon using a dual-loop temperature control and PID control algorithm until the cavity temperature change reaches a threshold within a preset time; a coupling module 13 for coupling the temperature-controlled Fabry-Perot etalon to a wavelength-tunable laser source, and then irradiating the photoacoustic cell using the laser source; a denoising module 14 for detecting and acquiring photoacoustic signals using a photodetector, and denoising the photoacoustic signals using a second harmonic wavelength modulation method; and a reconstruction module 15 for reconstructing the denoised photoacoustic signals based on compressed sensing and a two-step iterative contraction method.

[0075] Furthermore, the denoising module 14 includes: an extraction unit, used to synchronously detect the phase difference between the photoacoustic signal and the reference signal through a lock-in amplifier, and extract the second harmonic component of the photoacoustic signal; a calculation unit, used to calculate the intensity and distribution of the photoacoustic signal based on the amplitude and phase changes of the second harmonic component; and a denoising unit, used to denoise the photoacoustic signal based on the intensity and distribution of the photoacoustic signal.

[0076] Example 3

[0077] refer to Figure 4 A third aspect of the present invention provides an electronic device comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the photoacoustic spectrum detection method with laser wavelength deviation detection of the first aspect of the present invention.

[0078] Electronic device 500 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 502 or a program loaded from storage device 508 into random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of electronic device 500. The processing unit 501, ROM 502, and RAM 503 are interconnected via bus 504. An input / output (I / O) interface 505 is also connected to bus 504.

[0079] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 508 including, for example, hard disks; and communication devices 509. Communication device 509 allows electronic device 500 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 4 An electronic device 500 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 4 Each box shown can represent a device or multiple devices as needed.

[0080] Specifically, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by a processing device 501, it performs the functions defined in the methods of embodiments of this disclosure. It should be noted that the computer-readable medium described in embodiments of this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In embodiments of this disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In embodiments of this disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0081] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more computer programs, which, when executed by the electronic device, cause the electronic device to:

[0082] Computer program code for performing the operations of embodiments of this disclosure can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, C++, and Python—and conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0083] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of detecting photoacoustic spectroscopy with laser wavelength deviation detection, characterized by, The method comprises the following steps: Calibrating a Fabry-Perot etalon based on a standard light source with multiple wavelengths of target laser; Controlling the cavity temperature of the calibrated Fabry-Perot etalon by a double-loop temperature control and a PID control algorithm until the cavity temperature change reaches a threshold value within a preset time; Coupling the temperature-controlled Fabry-Perot etalon with a wavelength-tunable laser source, and then irradiating the photoacoustic cell with the laser source; Detecting and collecting the photoacoustic signal by a photodetector, and denoising the photoacoustic signal by a second-harmonic wavelength modulation method; Reconstructing the denoised photoacoustic signal based on compressed sensing and a two-step iterative shrinkage method: reconstructing the initial pressure distribution of the photoacoustic signal from sparse measurement data by the compressed sensing method; updating and iterating the initial pressure distribution by the two-step iterative shrinkage method until the soft threshold difference between adjacent iteration signals is lower than a preset value; the soft threshold is calculated by the following steps: ， wherein T represents a soft threshold The step of controlling the cavity temperature of the calibrated Fabry-Perot etalon by a double-loop temperature control and a PID control algorithm includes the following steps: represents a threshold parameter, x represents a photoacoustic signal, sign(x) represents a sign function.

2. The method of photoacoustic spectroscopy with laser wavelength deviation detection according to claim 1, characterized in that, Installing a thermoelectric cooler and a temperature sensor at multiple positions in the cavity of the Fabry-Perot etalon to detect the cavity temperature in real time; Controlling the hot measurement temperature of the thermoelectric cooler by an outer loop PID controller, and then controlling the cold measurement temperature of the thermoelectric cooler to be stable by an inner loop PID controller after the hot measurement temperature is stable; Setting the cavity temperature of the Fabry-Perot etalon, and controlling the cavity temperature of the calibrated Fabry-Perot etalon by the stable outer loop PID controller and the inner loop PID controller until the cavity temperature change reaches a threshold value within a preset time. The control method of the outer loop PID controller is represented as:

3. The method of detection of photoacoustic spectroscopy with laser wavelength deviation detection according to claim 2, characterized in that, The step of denoising the photoacoustic signal by a second-harmonic wavelength modulation method includes the following steps: ， Synchronously detecting the phase difference between the photoacoustic signal and a reference signal by a lock-in amplifier, and extracting the second-harmonic component of the photoacoustic signal; represents a controller output adjustment voltage; Calculating the intensity and distribution of the photoacoustic signal based on the amplitude and phase change of the second-harmonic component; represents a temperature error, K p 、K i 、K d represents a proportional gain, an integral gain, and a derivative gain, respectively.

4. The method of photoacoustic spectroscopy with laser wavelength deviation detection according to claim 1, characterized in that, Denoising the photoacoustic signal based on the intensity and distribution of the photoacoustic signal. The method comprises the following steps: A calibration module is configured to calibrate a Fabry-Perot etalon based on a standard light source with multiple wavelengths of target laser; A control module is configured to control the cavity temperature of the calibrated Fabry-Perot etalon by a double-loop temperature control and a PID control algorithm until the cavity temperature change reaches a threshold value within a preset time; 5. A photoacoustic spectroscopy detection system with laser wavelength deviation detection, characterized by, A coupling module is configured to couple the temperature-controlled Fabry-Perot etalon with a wavelength-tunable laser source, and then irradiate the photoacoustic cell with the laser source; A denoising module is configured to detect and collect the photoacoustic signal by a photodetector, and denoise the photoacoustic signal by a second-harmonic wavelength modulation method; ​ ​ ​ The reconstruction module is configured to reconstruct the de-noised photoacoustic signal based on compressed sensing and a two-step iterative shrinkage method: reconstructing an initial pressure distribution of the photoacoustic signal from sparse measurement data by the compressed sensing method; and performing an updating iteration on the initial pressure distribution until a soft threshold difference between adjacent iteration signals is lower than a preset value by the two-step iterative shrinkage method; the soft threshold is calculated by the following steps: ， wherein T represents a soft threshold λ represents a threshold parameter, x represents a photoacoustic signal, sign(x) represents a sign function.

6. The photoacoustic spectroscopy detection system with laser wavelength deviation detection of claim 5, wherein, The de-noising module comprises: an extraction unit configured to detect a phase difference between the photoacoustic signal and the reference signal synchronously by a lock-in amplifier, and extract a second harmonic component of the photoacoustic signal; a calculation unit configured to calculate an intensity and a distribution of the photoacoustic signal based on amplitude and phase changes of the second harmonic component; a de-noising unit configured to de-noise the photoacoustic signal based on the intensity and the distribution of the photoacoustic signal.

7. An electronic device, comprising: one or more processors; a storage device configured to store one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement the method for detecting photoacoustic spectroscopy with laser wavelength deviation detection according to any one of claims 1 to 4.

8. A computer readable medium having stored thereon a computer program, wherein, The computer program, when executed by the processor, implements the method for detecting photoacoustic spectroscopy with laser wavelength deviation detection according to any one of claims 1 to 4.

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