Diamond color center based temperature and stress simultaneous decoupling sensing method and device

Abstract

The application provides a kind of temperature and stress synchronous decoupling sensing method and device based on diamond color center, belongs to quantum sensing and precision measurement technical field.The scheme constructs the spin total hamiltonian containing hyperfine interaction, obtains multiple sets of energy level transition relationship by combining nuclear spin subspace block processing, constructs four sets of over-determined constraint equations, and solves zero-field splitting parameters and strain parameters by using weighted nonlinear least squares algorithm iterative fitting, effectively improves parameter solving precision and noise immunity;At the same time, the measurement uncertainty is quantified by covariance matrix, and the internal self-checking of measurement results is realized relying on fixed hyperfine coupling constant, and the degraded data is automatically removed.The application does not need external magnetic field, and can realize the decoupling synchronous measurement of temperature and stress by relying on ODMR multi-peak redundant information, effectively suppresses the interference of optical path noise, baseline drift and frequency drift, and significantly improves the stability, reliability and measurement accuracy of quantum sensing measurement under zero field condition.

Description

Technical Field

[0001] This application relates to the field of quantum sensing and precision measurement technology, and in particular to a method and device for synchronous decoupling of temperature and stress sensing based on diamond color centers. Background Technology

[0002] Temperature and mechanical stress are two of the most critical physical quantities in characterizing the health status of critical equipment and precision instruments. In practical applications, they are often highly coupled; thermal expansion causes stress changes, and stress release is accompanied by temperature fluctuations. However, existing sensing technologies have limitations in multi-parameter measurement. For example, thermocouples and platinum resistance thermometers have high temperature measurement accuracy but cannot simultaneously sense stress; traditional metal strain gauges suffer from severe temperature cross-sensitivity, making decoupling extremely difficult; while fiber Bragg gratings have the advantages of insulation and anti-interference, their wavelength drift is affected by the inherent coupling between temperature and strain, limiting the accuracy of dual-parameter demodulation; existing diamond NV color center sensing schemes typically rely on an external bias magnetic field to degenerate the ground state energy level. The strong alternating leakage magnetic field inside industrial equipment, especially power grid equipment, can severely interfere with the bias magnetic field, introducing huge systematic errors and making it impossible to accurately decouple temperature and stress.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main objective of this application is to propose a method and device for simultaneous decoupling of temperature and stress sensing based on diamond color centers, so as to realize the joint decoupling measurement of temperature and stress in a zero magnetic field environment.

[0005] To achieve the above objectives, one aspect of this application proposes a method for synchronous decoupling of temperature and stress sensing based on diamond color centers, the method comprising: Under zero-field conditions, laser excitation and microwave excitation are applied together to the NV color center of diamond, causing the NV color center to generate a fluorescence signal containing ODMR information; The laser excitation and the fluorescence signal are balanced and matched to obtain a differential voltage signal; The differential voltage signal is phase-sensitively demodulated with a low-frequency modulation signal of a preset frequency to obtain a demodulated signal. An initial ODMR spectrum is constructed by real-time sampling of the demodulated signal and the microwave frequency of the microwave excitation. The initial ODMR spectrum is updated by introducing a hyperfine interaction term to analyze the total spin Hamiltonian of the ground-state electrons, thus obtaining the ODMR characteristic spectrum. The resonance frequency is extracted from the ODMR characteristic spectrum and the temperature and stress are obtained by iterative inversion and decoupling calculation.

[0006] Preferably, after obtaining the demodulated signal, the process includes: Feedback control calculations are performed based on the correspondence between the resonant frequency of the NV color center, the center carrier frequency of the microwave excitation, and the demodulated signal to adaptively adjust the center carrier frequency, thereby obtaining the adjusted center carrier frequency. A frequency-modulated microwave signal is generated based on the adjusted center carrier frequency and the low-frequency modulation signal, and the frequency-modulated microwave signal is used as the microwave excitation to act on the NV color center.

[0007] Preferably, the initial ODMR spectrum is updated by introducing a hyperfine interaction term to resolve the total spin Hamiltonian of the ground-state electrons, resulting in an ODMR characteristic spectrum. The resonance frequencies are then extracted from the ODMR characteristic spectrum, and the temperature and stress are calculated through iterative inversion and decoupling. This includes: Under zero-field conditions, the total spin Hamiltonian is calculated by introducing a hyperfine interaction term to update the initial ODMR spectrum and obtain the ODMR characteristic spectrum, and the resonance frequency is extracted from the ODMR characteristic spectrum. The total Hamiltonian matrix is ​​obtained based on the total spin Hamiltonian, and the total Hamiltonian matrix is ​​divided into blocks for dimensionality reduction based on different values ​​of nuclear spin projection to obtain sub-matrices corresponding to different nuclear spin projection values. Calculate the eigenvalues ​​corresponding to the submatrices respectively, and construct an overdetermined system of equations based on multiple sets of eigenvalues; Construct a residual vector for the overdetermined system of equations based on the eigenvalues ​​and the resonant point frequencies; The objective function is constructed based on the residual vector, and the objective function is iteratively solved using the least squares algorithm to obtain the relevant convergence value and covariance matrix. Decoupling calculations are performed based on the convergence value to obtain initial calculation results; The initial calculation results are verified based on the hyperfine coupling constant and the covariance matrix, and the final temperature and stress are output.

[0008] Preferably, when constructing the residual vector, the eigenvalues ​​are converted into theoretical values ​​to obtain the theoretical resonance frequency, the resonance point frequency is used as the observed value, and the zero-field splitting parameter and strain parameter are used as unknowns to be solved. The difference between the observed value and the theoretical resonance frequency is calculated item by item, and the residual vector is obtained after arranging them in sequence.

[0009] Preferably, the weighting weights are determined based on the signal-to-noise ratios corresponding to each resonance characteristic peak, and the weighted sum of squared residuals is constructed as the objective function in combination with the residual vector.

[0010] Preferably, the convergence of the objective function is determined according to a preset convergence criterion, which includes a parameter update step size criterion and an objective function criterion. The iteration stops when either condition is met.

[0011] To achieve the above objectives, another aspect of this application proposes a temperature and stress synchronous decoupling sensing device based on diamond color centers, the device including a laser for outputting continuous wave green laser to a beam splitter. The beam splitter is used to output two signals. One signal is used as a laser optical path input to the diamond probe to excite the NV color center to generate red fluorescence. After being collected and filtered by the fluorescence collection device, a pure fluorescence signal is obtained and input to the balanced photodetector. The other signal is used as a reference optical path and directly input to the balanced photodetector. The balanced photodetector is used to output a differential voltage signal to the optoelectronic microwave transceiver module based on the reference optical path and the pure fluorescence signal; The optoelectronic microwave transceiver module includes a microwave antenna for radiating frequency-modulated microwave signals input to the diamond probe. When the microwave frequency of the frequency-modulated microwave signal matches the resonant frequency of the NV color center, the optoelectronic microwave transceiver module performs phase-sensitive demodulation based on the differential voltage signal and the internal low-frequency modulation signal to obtain a demodulated signal. The ODMR spectrum is obtained by real-time sampling of the demodulated signal and the microwave frequency, and the temperature and stress are obtained by inversion calculation based on the resonant point frequency in the ODMR spectrum.

[0012] Preferably, the optoelectronic microwave transceiver module further includes a lock-in amplifier, a PID controller, and a microwave source; The lock-in amplifier is used to perform phase-sensitive demodulation processing on the differential voltage signal and the low-frequency modulation signal to obtain a demodulated signal; it is also used to sample the demodulated signal and the microwave frequency in real time to obtain an ODMR spectrum, and to calculate the decoupled temperature and stress based on the resonant frequency in the ODMR spectrum. The PID device is used to receive the demodulated signal, and perform PID calculations according to the correspondence between the resonant frequency, the center carrier frequency and the demodulated signal, to adaptively adjust the center carrier frequency and output the corresponding feedback control voltage to the microwave source. The microwave source is used to generate a frequency-modulated microwave signal based on the center carrier frequency corresponding to the feedback control voltage and the internal low-frequency modulation signal, and output the frequency-modulated microwave signal to the microwave antenna; it is also used to output the low-frequency modulation signal to the lock-in amplifier.

[0013] Preferably, in the PID device, PID calculation is performed based on the correspondence between the resonant frequency, the center carrier frequency, and the demodulated signal to adaptively adjust the center carrier frequency, including: When the center carrier frequency is greater than the resonant frequency, the corresponding demodulated signal is less than zero. The PID device reduces the center carrier frequency by lowering the feedback control voltage, thereby driving the center carrier frequency toward the resonant frequency. When the center carrier frequency is less than the resonant frequency, the corresponding demodulated signal is greater than zero, and the PID device increases the center carrier frequency by increasing the feedback control voltage. When the center carrier frequency is equal to the resonant frequency, the corresponding demodulation signal is equal to zero, and the PID device maintains the feedback control voltage unchanged to lock the center carrier frequency to the resonant frequency.

[0014] To achieve the above objectives, this application also proposes an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0015] To achieve the above objectives, this application also proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0016] To achieve the above objectives, this application also proposes a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0017] This application includes at least the following beneficial effects: This application provides a method and apparatus for synchronous decoupling sensing of temperature and stress based on diamond color centers. This scheme acquires the fluorescence signal of the NV color center using a diamond probe, and completes differential photoelectric conversion in conjunction with a balanced photodetector. This effectively suppresses common-mode noise in the optical path, reduces measurement interference caused by light intensity fluctuations, and outputs a differential voltage signal with a better signal-to-noise ratio, providing a high-quality raw photoelectric signal for subsequent signal demodulation. In the phase-locked demodulation and closed-loop microwave control stages, the differential voltage signal is phase-sensitively demodulated by a lock-in amplifier to extract the first derivative differential spectrum signal of ODMR. The PID device, combined with the demodulated signal, forms a closed-loop feedback to adjust the microwave frequency output by the microwave source in real time, achieving automatic tracking of the microwave frequency to the NV color center resonance point. This counteracts resonance point drift caused by environmental disturbances, ensuring that the microwave excitation is always aligned with the energy level resonance position, and avoiding offset errors caused by manual frequency sweeping. Based on closed-loop tracking, a high-resolution frequency sweep is performed to acquire the initial ODMR spectrum. The initial ODMR spectrum is then subjected to baseline correction, denoising, and coarse peak finding to remove interference from baseline drift and random noise, resulting in preprocessed spectral data to reduce the error probability in subsequent peak finding and fitting processes.

[0018] This application forms a complete chain from photoelectric acquisition, closed-loop microwave tracking, and spectral sampling preprocessing to quantum Hamiltonian modeling, weighted fitting of overdetermined equations, parameter uncertainty assessment, and built-in self-verification. Utilizing the multi-peak redundancy information brought about by hyperfine splitting, it achieves decoupled synchronous measurement of temperature and stress under zero-field conditions, effectively reducing single-parameter extraction errors. Relying on the internal hyperfine coupling constant, it completes result self-verification, automatically identifying and discarding degraded data, effectively combating optical path noise, frequency drift, and spectral distortion. This enables high-precision, high-reliability synchronous decoupled measurement of temperature and stress using a diamond NV color center sensor in a zero-field environment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the steps of the temperature and stress synchronous decoupling sensing method based on diamond color centers provided in the embodiments of this application; Figure 2 This is a schematic diagram of the temperature and stress synchronous decoupling sensing device based on diamond color centers provided in the embodiments of this application; Figure 3 This is a schematic diagram of the energy level structure and transition frequencies of the ground state triplet state of diamond NV color center under zero magnetic field. Figure 4 It is the ground state triplet state of diamond NV color center under consideration 14 A schematic diagram of the energy level structure and transition frequency under the N-fine level splitting condition; Figure 5 This is a zero-field ODMR experimental spectral feature map captured in the embodiments of this application; Figure 6 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application.

[0020] Figure reference numerals: Laser 11; Beam splitter 12; Diamond probe 13; Fluorescence collection device 14; Balanced photodetector 15; Lock-in amplifier 16; PID device 17; Microwave source 18; Microwave antenna 19. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0022] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0023] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0025] Existing sensing technologies cannot simultaneously achieve accurate decoupling of temperature and stress. Furthermore, in schemes based on diamond NV centers for parameter measurement, the reliance on an external bias magnetic field introduces significant systematic errors, leading to inaccurate decoupling of temperature and stress. Therefore, this application provides a method and apparatus for simultaneous decoupling of temperature and stress based on diamond NV centers. In a zero-magnetic-field environment, parameters are directly extracted by analyzing the Hamiltonian of the ground-state electron spin. The resonance spectrum under zero field is obtained using ODMR technology. Two central resonance frequencies, f- and f+, generated by the transverse splitting of energy levels due to transverse stress are acquired. An inversion relationship is then used to achieve orthogonal decoupling of the zero-field splitting parameter D and the strain parameter E. Additionally, nitrogen nuclei are introduced from the NV centers. 14 The nuclear spin hyperfine interaction of N extends the bimodal model to a six-peak structure analysis. By analyzing the energy level degeneracy caused by the nuclear spin state, the residual parameter crosstalk is completely eliminated by using the overdetermined equations, achieving high-precision decoupling of temperature and stress parameters, and improving the anti-interference online sensing capability of multi-physics fields in complex and strong electromagnetic environments.

[0026] The temperature and stress synchronous decoupling sensing method and device based on diamond color centers provided in this application relates to the fields of quantum sensing and precision measurement. The temperature and stress synchronous decoupling sensing method and device based on diamond color centers provided in this application can be applied to a terminal, a server, or software running on a terminal or server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster composed of multiple physical servers, or a distributed system. It can also be configured as a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing the temperature and stress synchronous decoupling sensing method and device based on diamond color centers, but is not limited to the above forms.

[0027] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0028] Based on rigorous quantum mechanics, this application proposes to directly extract parameters by analyzing the Hamiltonian of the ground-state electron spin in a zero-magnetic-field environment. By using a high-permeability shielding structure to isolate the background magnetic field, and employing microwave scanning optical probe magnetic resonance (ODMR) technology, the resonance spectrum under zero-field conditions is obtained. Due to the lateral stress / strain disrupting the symmetry of the crystal lattice, the energy levels undergo lateral splitting. This application obtains the two central resonance frequencies generated by this splitting. And using the inversion relationship as well as This directly achieves the orthogonal decoupling of the zero-field splitting parameter D and the strain parameter E.

[0029] Specifically, the ground state of the diamond NV color center is a spin triplet state with a total electron spin quantum number S=1. Under strictly zero bias magnetic field or magnetic shielding conditions, and ignoring extremely weak other perturbations, its ground state electron spin Hamiltonian is... It mainly consists of two parts: zero-field splitting (ZFS) and stress, represented as: (1) In equation (1), Here, S represents the dimensionless Pauli spin matrix with a spin quantum number of S=1; D is the axial zero-field splitting parameter, i.e., the temperature-dependent parameter, whose value is mainly determined by electron spin-spin interactions and has a very strong linear correlation with temperature T; E is the transverse zero-field splitting parameter, i.e., the strain parameter, which is determined when the diamond lattice is subjected to transverse stress / strain failure. When rotationally symmetric, the value of E is not zero, and its magnitude is proportional to the transverse stress.

[0030] According to the fundamental principles of quantum mechanics, a quantum particle with a spin quantum number of S=1... The spin matrix under the representation is as follows: (2) (3) (4) In equations (2), (3), and (4), i represents an imaginary number. Among the three matrices... It is a real diagonal matrix. It is a real symmetric matrix. Let be a pure imaginary antisymmetric matrix containing the imaginary unit i, and the three together form a complete set of S=1 spin operators.

[0031] Calculated by matrix multiplication and The matrix form of the stress term can be derived, expressed as: (5) Substituting the spin matrices (2) and (5) into the ground-state Hamiltonian equation (1), we obtain the matrix representation of the Hamiltonian of the system under zero magnetic field: (6) Solving the eigenvalue equations of the ground-state Hamiltonian equation (1) We can obtain the eigenvalues ​​of three energy levels, excluding the ground state eigenvalue. In addition, there are two excited-state eigenvalues. and .

[0032] The above derivation physically proves that, under zero magnetic field conditions, due to the existence of transverse stress E, The degenerate states underwent mixing and splitting, forming two new eigenstates. At this point, in continuous wave optical detection magnetic resonance (CW-ODMR) testing, the eigenstates were excited from... The transition to the two splitting energy levels mentioned above will result in two distinct microwave resonance absorption peaks in the spectrum, namely... .

[0033] Through simple algebraic calculations, this application can measure temperature changes in a single measurement. and stress changes Perfect peeling is represented as: (7) (8) In equations (7) and (8), , These are the pre-calibrated temperature coefficient and stress sensitivity coefficient, respectively. is the zero-field splitting constant at the reference temperature.

[0034] Furthermore, this application introduces a nitrogen nucleus in the NV color center. 14 The hyperfine interaction of N nuclear spins elucidates the bimodal structure into a six-peak structure. The physical origin of the six-peak structure is as follows: 14 The N-nucleus has a spin quantum number I=1, possessing Three projection states. Consider the hyperfine coupling term. After (A≈2.158MHz), the Hamiltonian is block-diagonalized in a 9×9 matrix space, where The sub-block gives the same two central resonance frequencies as the case without nuclei and spin ( );and and The eigenvalues ​​of both sub-blocks are Since their eigenvalues ​​are exactly the same, they undergo degeneracy and superposition, resulting in two outer peaks with doubled intensity in the spectrum, located at... Place.

[0035] When there is weak stress or no stress, that is At this time, the outer peak frequency is approximately D±A, and the distance between the inner and outer peaks is approximately A≈2.158MHz. When there is significant stress, i.e., E cannot be ignored, the outer peak undergoes a nonlinear shift, which can be precisely expressed as... By combining the four peak frequencies, the inner two peaks provide a linear combination of the zero-field splitting parameter D and the strain parameter E, while the outer two peaks provide a linear combination of the zero-field splitting parameter D and the strain parameter E. A linear combination of equations is used to construct a four-equation overdetermined system of equations containing the zero-field splitting parameter D and the strain parameter E. The system is then solved globally using the least squares method, which can effectively suppress parameter extraction errors caused by noise and completely eliminate residual crosstalk between the zero-field splitting parameter D and the strain parameter E. This allows for extremely high-precision absolute decoupling of temperature and stress in a single measurement.

[0036] Please see Figure 1 As shown, Figure 1 This is a schematic diagram of an optional step in the temperature and stress synchronous decoupling sensing method based on diamond color centers provided in this application embodiment. Figure 1 The method may include, but is not limited to, steps S1 to S5: S1, under zero-field conditions, laser excitation and microwave excitation are applied together to the NV color center of diamond, causing the NV color center to generate a fluorescence signal containing ODMR information.

[0037] In this embodiment, a continuous-wave green laser with a fixed wavelength, such as 532 nm, is output from laser 11 as laser excitation, and a frequency-modulated microwave signal radiated from microwave antenna 19 is used as microwave excitation. The laser excitation and microwave excitation work together to excite the diamond NV center inside the diamond probe 13, generating red fluorescence in the 637-800 nm band. The fluorescence signal carries NV center spin resonance (ODMR, Optically Detected Magnetic Resonance) information. When the microwave scan passes over the NV center spin resonance point, a spin-flipping effect occurs, directly causing a decrease in fluorescence intensity and forming an ODMR characteristic spectrum signal. This ODMR characteristic spectrum signal carries the temperature and stress coupling information of the sample under test.

[0038] S2 balances and matches the laser excitation and fluorescence signal to obtain a differential voltage signal.

[0039] The green laser output from laser 11 is collimated and then split by beam splitter 12. Most of the beam serves as the laser path to the diamond probe 13 to excite the NV color center and generate red fluorescence. The fluorescence is collected by fluorescence collection device 14, and the 532nm laser scattering interference light is filtered out to obtain a pure fluorescence signal, which is then input into the balanced photodetector 15. A small portion of the beam serves as a reference path and is directly sent to the balanced photodetector 15. Within the detector's dynamic range, the balanced photodetector 15 balances and matches the pure fluorescence signal with the reference laser path to cancel out the intensity drift and low-frequency common-mode noise caused by the laser. The two beams are then converted into photocurrents, which are differentially amplified by transimpedance gain to obtain a differential voltage signal.

[0040] S3, based on the differential voltage signal and the low-frequency modulation signal of the preset frequency, performs phase-sensitive demodulation to obtain the demodulated signal.

[0041] The differential voltage signal output by the balanced photodetector 15 carries ODMR resonance information of the NV color center. This signal is mixed with ambient light noise, circuit thermal noise, and common-mode interference caused by laser intensity fluctuations. The lock-in amplifier 16 receives this differential voltage signal and simultaneously receives a low-frequency modulation signal of a preset frequency provided by the microwave source 18. This low-frequency modulation signal and the low-frequency modulation applied to the microwave excitation are from the same source. The lock-in amplifier 16 internally performs a multiplication and mixing operation on the input differential voltage signal and the low-frequency modulation signal, shifting the target useful signal to the DC frequency band. Then, it passes through a low-pass filter to filter out high-frequency noise components that are not related to the modulation frequency, completing the phase-sensitive demodulation processing, suppressing device common-mode noise and unrelated background noise, and finally outputting a demodulated signal with improved signal-to-noise ratio. This demodulated signal is the first-order differential spectrum signal of ODMR.

[0042] In some embodiments, after obtaining the demodulated signal, the process includes: Feedback control calculations are performed based on the correspondence between the resonant frequency of the NV color center, the center carrier frequency of microwave excitation, and the demodulated signal to adaptively adjust the center carrier frequency, thereby obtaining the adjusted center carrier frequency. The demodulated signal output by the lock-in amplifier 16 is a first-order differential ODMR signal. The zero point of the demodulated signal output corresponds to the true resonant frequency of the NV color center. The sign of the demodulated signal represents the offset direction of the current microwave center carrier frequency relative to the NV color center resonant frequency, and the amplitude of the demodulated signal output represents the magnitude of the frequency deviation between the two. The PID device 17 receives the demodulated signal and uses the zero output of the demodulated signal as the control target. Based on the inherent mapping relationship between the NV color center resonant frequency, the microwave center carrier frequency, and the demodulated signal, it performs proportional-integral-derivative feedback control calculations to calculate and process the real-time frequency deviation, outputting a frequency correction amount. This frequency correction amount is superimposed on the original center carrier frequency of the microwave source 18 to achieve adaptive correction of the center carrier frequency, resulting in an adjusted center carrier frequency that follows the actual resonant point of the NV color center, thereby compensating for the NV color center resonant frequency drift caused by temperature and stress changes.

[0043] A frequency-modulated microwave signal is generated by adjusting the center carrier frequency and the low-frequency modulation signal, and the frequency-modulated microwave signal is used as microwave excitation to act on the NV color center.

[0044] Microwave source 18 receives the adjustment center carrier frequency output by PID device 17. Using this adjustment center carrier frequency as the carrier basis, it modulates the carrier frequency with a preset low-frequency modulation signal as the modulation source, generating a frequency-modulated microwave signal. This frequency-modulated microwave signal is output to the microwave antenna of diamond probe 13, where it is radiated onto the diamond NV color center in the form of microwave excitation, driving the NV color center spin energy level to undergo magnetic resonance transition. Simultaneously, the low-frequency modulation signal is output from the same source to lock-in amplifier 16 as a reference signal for phase-sensitive demodulation, thereby constructing a complete closed-loop circuit. This allows the microwave frequency of microwave excitation to track the dynamic changes of the NV color center resonance frequency in real time, maintaining a resonance-locked state.

[0045] S4, the demodulated signal and the microwave frequency of the microwave excitation are sampled in real time to construct the initial ODMR spectrum.

[0046] Specifically, the diamond NV center within the diamond probe 13 is continuously irradiated by a laser excitation source, pumping it to an excited state. A frequency-modulated microwave signal, continuously scanning from the microwave source 18, is fed into the diamond probe 13 via the microwave antenna 19, acting on the spin energy level of the NV center. When the microwave frequency of the frequency-modulated signal matches the resonant transition frequency of the NV center energy level, a change in the spin population occurs, causing a decrease in the fluorescence intensity of the NV center. At this time, the red fluorescence signal output by the diamond probe 13 is filtered by the fluorescence collection device 14 and then sent to the balanced photodetector 15. The balanced photodetector 15 converts the filtered pure fluorescence signal into a differential voltage signal. The output is then sent to the lock-in amplifier 16. The microwave source 18 outputs a scanning microwave signal (i.e., a frequency-modulated microwave signal) for energy level transitions, and a low-frequency modulation signal of the same origin as the scanning microwave, which is also sent to the lock-in amplifier 16. The lock-in amplifier 16 outputs the differential voltage signal from the balanced photodetector 15. Phase-sensitive demodulation is performed on the low-frequency modulation signal output from microwave source 18, and the demodulated signal is output. The host computer synchronously acquires the real-time microwave frequency of the microwave source 18 and the demodulated signal output from the lock-in amplifier 16. Using microwave frequency as the horizontal axis and demodulated signal as the vertical axis. Using the vertical axis, multiple sets of frequency-voltage data points are sampled and stitched together point by point to obtain the initial ODMR spectrum. This spectrum is an ODMR spectrum in the form of a first-order differential. The valley / peak positions of the initial ODMR spectrum correspond to the spin resonance transition frequencies of the NV color centers.

[0047] S5 introduces a hyperfine interaction term to analyze the total spin Hamiltonian of the ground-state electrons, updates the initial ODMR spectrum to obtain the ODMR characteristic spectrum, and extracts the resonance point frequency from the ODMR characteristic spectrum. The temperature and stress are then obtained by iterative inversion and decoupling calculation.

[0048] In some embodiments, the initial ODMR spectrum is updated by introducing a hyperfine interaction term to resolve the total spin Hamiltonian of the ground-state electrons, thus obtaining the ODMR characteristic spectrum. The resonance frequencies are then extracted from the ODMR characteristic spectrum, and the temperature and stress are calculated through iterative inversion and decoupling, including: S51, under zero field conditions, the total spin Hamiltonian is calculated by introducing a hyperfine interaction term to update the initial ODMR spectrum and obtain the ODMR characteristic spectrum, and the resonance point frequency is extracted from the ODMR characteristic spectrum. Under zero-field conditions, the hyperfine interaction term between nitrogen nucleus spin and electron spin is incorporated into the Hamiltonian construction process. This involves superimposing a hyperfine coupling term onto the electron spin Hamiltonian to construct a total spin Hamiltonian that incorporates the coupling effects of electron and nuclear spin. This total spin Hamiltonian is then represented by a matrix and diagonalized to calculate multiple theoretical transition frequencies resulting from hyperfine coupling splitting. These theoretical transition frequencies are used to correct and update the initial ODMR spectrum obtained from hardware sampling, correcting peak shifts and splitting biases caused by the initial ODMR spectrum's failure to consider hyperfine nuclear spin splitting. This yields an ODMR characteristic spectrum that incorporates the hyperfine splitting effect. Peak-finding processing is then performed on the ODMR characteristic spectrum to identify the positions of each split resonance peak, extracting multiple precise resonance point frequencies. This provides measured frequency input data for subsequent matrix partitioning, equation construction, and parameter inversion.

[0049] S52, the total Hamiltonian matrix is ​​obtained from the total spin Hamiltonian, and the total Hamiltonian matrix is ​​divided into blocks for dimensionality reduction according to different values ​​of nuclear spin projection to obtain sub-matrices corresponding to different nuclear spin projection values. S53, calculate the eigenvalues ​​corresponding to the submatrices respectively, and construct an overdetermined system of equations based on multiple sets of eigenvalues; To further improve measurement accuracy, this embodiment combines the most abundant diamond... 14 Signal analysis using the nuclear spin of nitrogen isotopes. 14 The N nucleus has a spin quantum number I=1 and three nuclear magnetic projection states. Introducing into the NV electron spin Hamiltonian 14 The hyperfine interaction terms of the N-nuclear spin yield the total spin Hamiltonian, which includes zero-field splitting, strain, and hyperfine interactions. , is represented as: (9) In equation (9), These are dimensionless Pauli spin matrices with a spin quantum number of S=1; A≈2.16MHz, representing... 14 The axial hyperfine coupling constant of N is determined by the fundamental constants of quantum mechanics and can be used as an internal reference quantity to achieve independent verification of measurement results. express 14The projection operator of the N-nuclear spin along the NV principal axis z direction, constrained by the nuclear spin quantum number I=1, has eigenvalues ​​corresponding to... Three nuclear spin projection states; The overall term is an electron-nuclear spin-axis hyperfine interaction term, used to characterize the energy level splitting effect caused by the magnetic moment coupling between the two.

[0050] Substituting the electron spin matrix and the nuclear spin matrix into equation (9) and performing a tensor product extension, we obtain the 9-dimensional total Hamiltonian matrix, expressed as: (10) In equation (10), the matrix rows are arranged according to the spin state, that is, the first, second and third rows of the matrix correspond to the electron spin. nuclear spin projection Rows 4, 5, and 6 correspond to electron spin. Rows 7, 8, and 9 correspond to electron spin. nuclear spin projection .

[0051] According to the different values ​​of nuclear spin projection, the 9-dimensional total Hamiltonian matrix is ​​divided into blocks for dimensionality reduction, and the 2×2 sub-matrices corresponding to nuclear spin projections of 0, +1, and -1 are extracted respectively, resulting in (11)(12)(13).

[0052] extract The corresponding matrix elements are selected from basis vectors |+1,0. and | 1,0 That is, the elements of the second and eighth rows of the total Hamiltonian matrix form a 2×2 submatrix, represented as: (11) exist Hyperfine interaction terms in subspace The matrix elements are proportional to ,because Since the hyperfine interaction term contributes zero, this submatrix retains only the zero-field splitting term. With strain term The contribution of the diagonal element is provided by the zero-field splitting term. and hour Therefore, both diagonal elements are D; the off-diagonal elements are provided by the strain coupling term, and the matrix elements take the value E; by solving the matrix eigenvalues ​​of equation (11), we obtain .

[0053] extract The corresponding matrix elements are selected from the basis vectors |+1,+1. and | 1,+1 That is, the elements of the first and seventh rows of the total Hamiltonian matrix form a 2×2 submatrix, represented as: (12) basis vectors |+1,+1 satisfy Zero-field splitting term contribution D, hyperfine interaction term contribute Superposition yields diagonal element D+A; basis vectors | 1,+1 satisfy Zero-field splitting term contribution D, hyperfine interaction term Contribution A·( 1)·(+1)= A, superimposed to obtain the diagonal element DA; the off-diagonal elements of the matrix originate from the coupling effect of the strain terms, and the matrix element takes the value E.

[0054] extract The corresponding matrix elements are selected from basis vectors |+1,-1. and |-1,-1 That is, the elements of the third and ninth rows of the total Hamiltonian matrix form a 2×2 submatrix, represented as: (13) basis vectors |+1,-1 satisfy Zero-field splitting term contribution D, hyperfine interaction term Contribution A·(+1)·(-1)=-A, superimposed to obtain diagonal element DA; basis vectors |-1,-1 satisfy Zero-field splitting term contribution D, hyperfine interaction term The contribution A·(-1)·(-1)=+A is superimposed to obtain the diagonal element D+A; the off-diagonal element of the matrix comes from the coupling effect of the strain term, and the matrix element takes the value E.

[0055] Comparing equations (12) and (13), it can be seen that the two submatrices only exchange the positions of their diagonal elements. For a second-order matrix, exchanging the diagonal elements does not change the characteristic equation, therefore the eigenvalues ​​of the two submatrices are exactly the same, and the eigenvalues ​​obtained by solving are all... .

[0056] 14 The N-axis hyperfine coupling constant A is a known fixed constant. By using multiple sets of eigenvalues ​​corresponding to different nuclear spin subspaces, an overdetermined system of equations can be constructed and solved simultaneously to obtain the zero-field splitting parameter D and the strain parameter E. The zero-field splitting parameter D carries temperature information, and the strain parameter E carries stress information, thereby realizing the decoupled synchronous measurement of the temperature and stress of the environment under test.

[0057] because The two submatrices have identical eigenvalues, so their resonance peaks overlap on the frequency axis. Due to degeneracy, the transition probability of this resonance doubles, resulting in two resonance peaks with double the intensity, as shown in the attached figure. Figure 4 As shown. Four characteristic peaks were captured using high-resolution frequency sweeping, including the two inner peaks. , and the two outer peaks , This constitutes an overdetermined system of four equations concerning the unknown zero-field splitting parameter D and strain parameter E, expressed as: (14) (15) (16) (17) Among them, A=2.158MHz is the hyperfine coupling constant, which is determined by the fundamental constants of quantum mechanics and can be independently verified as an internal reference quantity.

[0058] S54, construct the residual vector for the overdetermined system of equations based on the eigenvalues ​​and resonant frequencies; In some embodiments, when constructing the residual vector, the eigenvalues ​​are converted into theoretical values ​​to obtain the theoretical resonance frequency, the resonance point frequency is used as the observed value, and the zero-field splitting parameter and strain parameter are used as unknowns to be solved. The difference between the observed value and the theoretical resonance frequency is calculated item by item, and the residual vector is obtained after arranging them in sequence.

[0059] The eigenvalues ​​obtained by solving the total spin Hamiltonian submatrix are used as theoretical values, and four sets of theoretical resonance frequencies are obtained by conversion, corresponding to the theoretical values ​​in formulas (14), (15), (16), and (17), respectively. The measured resonance frequency extracted from the ODMR characteristic spectrum in step S51 is used as the observed value. The zero-field splitting parameter D and strain parameter E are used as unknowns to be solved. The difference between the measured resonance frequency and the theoretical resonance frequency calculated from the unknown parameters is calculated term by term, resulting in four sets of differences. These four sets of differences are then arranged sequentially to construct a residual vector, expressed as:

[0060] Each element in the residual vector represents the deviation between the theoretical calculation results of the corresponding equations in the overdetermined equation set and the measured resonance point frequency in the spectrum. The residual vector as a whole represents the fitting deviation of all four equations, providing deviation input for the subsequent construction of the least squares objective function and the iterative solution of the optimal zero-field splitting parameter D and strain parameter E.

[0061] S55, construct the objective function based on the residual vector, and iteratively solve the objective function based on the least squares algorithm to obtain the relevant convergence value and covariance matrix; In some embodiments, the weighting weights are determined based on the signal-to-noise ratios corresponding to each resonance characteristic peak, and the weighted sum of squared residuals is constructed as the objective function by combining the residual vector.

[0062] In some embodiments, the convergence of the objective function is determined according to a preset convergence criterion, which includes a parameter update step size criterion and an objective function criterion. The iteration stops when either condition is met.

[0063] The weighting is determined based on the signal-to-noise ratio (SNR) corresponding to each resonance characteristic peak. Outer characteristic peaks, with higher intensity and better SNR, are assigned larger weights. A weighted sum of squared residuals is then constructed using the residual vector as the objective function, expressed as: ,in, This represents the i-th weight. Let represent the i-th residual component. The objective function is solved iteratively using the LM (Levenberg-Marquardt) nonlinear least squares algorithm.

[0064] First, the initial values ​​for iteration are determined. Based on the measured inner resonance peak frequency extracted from the ODMR characteristic spectrum in step S51, two initial values ​​for iteration are obtained by direct linear solution, namely, the initial values ​​for temperature iteration are obtained by linear calculation according to formulas (14) and (15). with initial value of stress iteration The initial values ​​of the iteration are obtained by using only the inner double resonance peaks to complete a rough solution, without introducing the outer peaks and the hyperfine coupling constant A. The two initial values ​​obtained are used as the starting points of the Levenberg-Marquardt nonlinear least squares iteration. This can avoid the problem of local convergence and iteration divergence caused by improper selection of initial values ​​in the nonlinear iterative algorithm, and provide a reliable iterative starting position for the global optimal fitting of the subsequent overdetermined equation system.

[0065] Then, based on the initial values, the zero-field splitting parameter D and strain parameter E are continuously updated. The values ​​of the residual vector and the objective function are repeatedly calculated until the objective function satisfies the preset convergence criterion. At this point, the iterative calculation stops, and the convergence value of the temperature-dependent zero-field splitting parameter, i.e., the temperature-dependent convergence value, is output. And the convergence value of stress-related strain parameters, i.e., stress-related convergence value. .

[0066] The preset convergence criteria include two conditions: first, a parameter update step size criterion, where iteration stops when the changes in the zero-field splitting parameter D and strain parameter E before and after the iteration are both less than a pre-set parameter threshold, for example, 0.001 MHz; second, an objective function criterion, where iteration stops when the decrease in the weighted residual sum of squares objective function is less than a set function convergence threshold, and the objective function hardly decreases between two iterations. When at least one of the two conditions is met, the iteration is considered to have reached convergence, terminating the Levenberg-Marquardt iteration calculation to avoid meaningless loop calculations and prevent the algorithm from getting stuck in local oscillations, ensuring the output temperature-related convergence value. Stress-related convergence value To achieve a stable optimal solution.

[0067] Simultaneously, the covariance matrix is ​​calculated from the Jacobian matrix of the iterative solution process. This covariance matrix is ​​used to subsequently analyze the temperature-related convergence value of the parameter to be solved. Stress-related convergence value The corresponding parameter uncertainty, i.e., temperature-related uncertainty. Stress-related uncertainty .

[0068] Among them, temperature-related uncertainty Stress-related uncertainty The statistical fitting errors of the zero-field splitting parameter D and strain parameter E obtained from the fitting are respectively used to characterize the parameter extraction fluctuations caused by noise interference in the ODMR characteristic spectrum acquisition data. This can be determined based on the temperature-related uncertainty. Stress-related uncertainty The measurement uncertainty of the final output temperature and stress measurement results is further calculated, and the confidence interval of the measurement results is given, realizing the quantitative evaluation of the measurement error. The uncertainty is compared with the preset error threshold. If the uncertainty is too large, it indicates that the quality of the spectrum data is poor. The re-acquisition logic can be triggered to remove low-quality measurement data, avoid outputting unreliable temperature and stress decoupling results, and improve the reliability of the measurement results of the entire sensing device.

[0069] S56, Decouple the calculation based on the convergence value to obtain the initial calculation result; S57, the initial calculation results are verified based on the hyperfine coupling constant and the covariance matrix, and the final temperature and stress are output.

[0070] The temperature-related convergence value output by the least squares iteration Stress-related convergence value Substituting the values ​​into the calibration conversion formula for decoupling calculation, and using the pre-calibrated reference zero-field splitting parameters... Reference temperature Temperature coefficient Stress sensitivity coefficient ,according to The temperature decoupling results were calculated; according to The stress decoupling results are obtained through calculation. The temperature and stress values ​​obtained at this point are the initial calculation results. These initial calculation results are directly derived from the fitting convergence parameters and have not yet been cross-validated by introducing ultra-fine coupling constants. They need to be sent to the subsequent S57 step to complete the validity verification.

[0071] When verifying the initial calculation results, a known fixed nitrogen nucleus hyperfine coupling constant, such as A = 2.158 MHz, was extracted as an internal reference scale, and the theoretical relationship of the outer peak was used. A set of strain estimates is obtained through back-calculation. These back-calculated strain estimates are then compared with the stress-related convergence values ​​in the initial calculation results of S56. Perform a difference comparison. If the difference between the two sets of strain estimates is less than a preset threshold, such as 0.01MHz, the measurement data is considered valid, and the temperature and stress obtained from the S56 decoupling are directly output as the final measurement results. If the difference exceeds the preset threshold, it indicates that there is significant noise interference in the ODMR characteristic spectrum, peak position identification is incorrect, or the device has experienced frequency drift. The measurement results are deemed unreliable, and a re-acquisition command is triggered to re-execute the measurement and fitting process of S51-S56 until the verification is successful before outputting the final temperature and stress. This process suppresses erroneous measurement outputs caused by device drift and noise, ensuring the reliability of the decoupling results.

[0072] Please see Figure 2 As shown, another aspect of this application embodiment also provides a temperature and stress synchronous decoupling sensing device based on diamond color centers. The device includes a laser 11, which is used to output continuous wave green laser to a beam splitter 12. The beam splitter 12 is used to output two signals. One signal is used as a laser optical path input to the diamond probe 13 to excite the NV color center to generate red fluorescence. After being collected and filtered by the fluorescence collection device 14, a pure fluorescence signal is obtained and input to the balanced photodetector 15. The other signal is used as a reference optical path and directly input to the balanced photodetector 15. The balanced photodetector 15 is used to output a differential voltage signal to the optoelectronic microwave transceiver module based on the reference optical path and the pure fluorescence signal; The optoelectronic microwave transceiver module includes a microwave antenna 19, which is used to radiate frequency-modulated microwave signals to the diamond probe 13. When the microwave frequency of the frequency-modulated microwave signal matches the resonant frequency of the NV color center, the optoelectronic microwave transceiver module performs phase-sensitive demodulation based on the differential voltage signal and the internal low-frequency modulation signal to obtain the demodulated signal. The ODMR spectrum is obtained by real-time sampling of the demodulated signal and the microwave frequency, and the temperature and stress are obtained by inversion calculation based on the resonant point frequency in the ODMR spectrum.

[0073] In this embodiment, by inputting a 220V power supply or a fiber optic driver drive signal to the laser 11, the laser 11 is prompted to output a continuous wave green laser with a fixed wavelength, such as 532nm, and a power range of 50-500mW. After the beam is collimated, it is sent into the beam splitter 12.

[0074] The beam splitter 12 receives the collimated laser output from the laser 11 and outputs two signals after splitting. One signal serves as the laser beam path to illuminate the diamond probe 13 to excite the NV color center and generate red fluorescence. The other signal serves as the reference beam path and is sent directly to the reference end of the balanced photodetector 15 without passing through the sample. The splitting ratio is dynamically adjusted according to the fluorescence and reference light intensity. For example, in this embodiment, the ratio of the laser beam path to the reference beam path is 9:1.

[0075] The diamond probe 13 receives two inputs: one is an optical excitation input, namely a portion of the 532nm continuous-wave green laser split by the beam splitter 12; the other is a microwave excitation input, namely the frequency-modulated microwave signal radiated by the microwave antenna 19, with a signal frequency of [missing information]. Laser and microwave excitation work together to stimulate the diamond NV center inside the diamond probe 13, generating red fluorescence in the 637-800 nm wavelength range. This fluorescence signal carries NV center spin resonance (ODMR) information. When the microwave scan passes over the NV center spin resonance point, a spin-flip effect occurs, directly causing a decrease in fluorescence intensity and forming an ODMR characteristic spectrum signal. This ODMR characteristic spectrum signal carries temperature and stress coupling information of the sample. The diamond probe 13 ultimately outputs red fluorescence carrying ODMR information. This fluorescence is collected by the fluorescence collection device 14, which filters out the 532 nm laser scattering interference light to obtain a pure fluorescence signal.

[0076] The balanced photodetector 15 receives the pure fluorescence signal output from the fluorescence collection device 14 at its signal end, and receives the reference laser beam split from the beam splitter 12 at its reference end, serving as a noise benchmark. Within the detector's dynamic range, the balanced photodetector 15 balances and matches the power of the pure fluorescence signal and the reference laser beam to compensate for intensity drift and low-frequency common-mode noise introduced by the laser. The balanced photodetector 15 converts the pure fluorescence signal and the reference laser beam into photocurrents, i.e., signal optical path currents, respectively. With reference optical path current After differential amplification via transimpedance gain G, a differential voltage signal is output. .

[0077] In some embodiments, the optoelectronic microwave transceiver module further includes a lock-in amplifier 16, a PID device 17, and a microwave source 18; The lock-in amplifier 16 is used to perform phase-sensitive demodulation processing on the differential voltage signal and the low-frequency modulation signal to obtain the demodulated signal; it is also used to sample the demodulated signal and the microwave frequency in real time to obtain the ODMR spectrum, and to calculate the decoupled temperature and stress based on the resonant frequency in the ODMR spectrum. The PID device 17 is used to receive the demodulated signal and perform PID calculations according to the correspondence between the resonant frequency, the center carrier frequency and the demodulated signal, to adaptively adjust the center carrier frequency and output the corresponding feedback control voltage to the microwave source 18. The microwave source 18 is used to generate a frequency-modulated microwave signal based on the center carrier frequency corresponding to the feedback control voltage and the internal low-frequency modulation signal, and output the frequency-modulated microwave signal to the microwave antenna 19; it is also used to output the low-frequency modulation signal to the lock-in amplifier 16.

[0078] Lock-in amplifier 16 receives the differential voltage signal output from balanced photodetector 15. Simultaneously receive signals provided by microwave source 18 or signals from the same source as microwave source 18, with a frequency of [frequency value missing]. The low-frequency modulation signal, the lock-in amplifier 16 pairs of differential voltage signals Perform phase-sensitive demodulation processing on the low-frequency modulated signal to output the demodulated signal. To PID device 17. Demodulated signal The ODMR absorption peak is at the center carrier frequency The corresponding first derivative differential spectrum signal is zero at the resonance center, and the output polarities are opposite on both sides of the resonance center. The function of the lock-in amplifier 16 is to extract the weak ODMR differential error signal from the noise background, which is used to characterize the frequency shift of the current microwave center carrier frequency relative to the true resonance point of the diamond NV color center.

[0079] PID device 17 receives the demodulated signal output from lock-in amplifier 16. The PID controller performs PID calculations based on the correspondence between the resonant frequency, the center carrier frequency, and the demodulated signal to adaptively adjust the center carrier frequency of the microwave source 18. The proportional gain controls the frequency locking speed, with a typical configuration achieving an open-loop gain bandwidth of approximately 100Hz. The integral gain eliminates static frequency errors, with an integration time of 5-50ms. The derivative gain suppresses high-frequency loop oscillations and can be set to zero if necessary; in practical applications, a proportional-integral control mode can be used. In this embodiment, the closed-loop bandwidth of the PID device 17 can be set to 100Hz-1kHz, enabling it to track slowly changing temperature fields and mechanical thermal shocks, meeting the dynamic monitoring requirements of kHz-level high-frequency mechanical vibrations. After calculation, the PID device 17 outputs a feedback control voltage. Feedback control voltage to the frequency control terminal of microwave source 18 Used to adjust the center carrier frequency of microwave source 18. .

[0080] The microwave source 18 has an internal FM modulator, which is used to generate frequencies. The low-frequency modulated signal has a modulation depth Δf ≈ 100 kHz, which is much smaller than the ODMR spectral linewidth to ensure that the linear approximation condition of the differential spectrum holds. Microwave source 18 is combined with feedback control voltage. Corresponding center carrier frequency An internal low-frequency modulation signal is used to generate a frequency-modulated microwave signal, the instantaneous frequency of which satisfies: , where t represents the instantaneous moment.

[0081] Microwave source 18 outputs a frequency-modulated microwave signal with a power of 10-100mW to microwave antenna 19; wherein, the center carrier frequency... The initial value is determined by pre-sweep, and is preset at the NV color center resonant frequency. or nearby.

[0082] The frequency-modulated microwave signal is radiated to the diamond probe 13 via the microwave antenna 19, exciting the NV color center to generate an ODMR fluorescence signal, thus forming a complete closed-loop signal link. Specifically, a differential voltage signal is output through the balanced photodetector 15. →The demodulated signal is obtained by demodulation by lock-in amplifier 16. →PID device 17 calculates the output feedback control voltage →Microwave source 18 controls voltage based on feedback Update center carrier frequency A 10kHz low-frequency modulated output frequency-modulated microwave signal is superimposed and radiated by microwave antenna 19 to diamond probe 13. The NV color center generates a new ODMR fluorescence signal, which re-enters the photoelectric detection stage, forming a closed-loop link. This closed-loop link continuously locks the microwave carrier frequency at the ODMR resonance point of the NV color center. The center carrier frequency can be updated in real time according to the resonance point drift caused by temperature and stress changes. Subsequently, temperature and stress parameters can be decoupled and calculated based on the real-time acquired center carrier frequency.

[0083] In some embodiments, the PID device 17 performs PID calculations based on the correspondence between the resonant frequency, the center carrier frequency, and the demodulated signal to adaptively adjust the center carrier frequency, including: When the center carrier frequency is greater than the resonant frequency, the corresponding demodulated signal is less than zero. The PID device 17 reduces the feedback control voltage to lower the center carrier frequency, driving the center carrier frequency to tend towards the resonant frequency. When the center carrier frequency is less than the resonant frequency, the corresponding demodulated signal is greater than zero. The PID device 17 raises the center carrier frequency by increasing the feedback control voltage. When the center carrier frequency equals the resonant frequency, the corresponding demodulation signal is zero. The instantaneous PID device 17 maintains the feedback control voltage unchanged to lock the center carrier frequency to the resonant frequency.

[0084] Demodulated signal The output of lock-in amplifier 16, i.e., the derivative signal of ODMR, is... hour When it is too high When it is low That is, when This indicates that the center carrier frequency (microwave frequency) is too high. The PID device 17 reduces the feedback control voltage. Adjust the center carrier frequency below Drive center carrier frequency Towards the resonant frequency ;when This indicates that the center carrier frequency (microwave frequency) is too low. The PID device 17 increases the feedback control voltage. The above center carrier frequency ;when Time corresponding The PID device 17 maintains the feedback control voltage. Remain unchanged to lock the center carrier frequency. To the resonance point.

[0085] It should be noted that the center carrier frequency output by microwave source 18 The center microwave carrier signal is the resonance center of the spin level of the NV center. This center carrier frequency corresponds to the inherent resonance frequency of the spin magnetic dipole transition under zero field in the diamond NV center, and is the target center frequency for ODMR scanning.

[0086] Specifically, the ground-state spin energy level of the diamond NV color center The microwave driving frequency required for the spin transition between the two is the center carrier frequency. Under conditions of no external magnetic field and no strain disturbance, the zero-field splitting parameter D of the NV color center determines this center carrier frequency, satisfying the following conditions. D is the zero-field splitting constant, and h is Planck's constant. Throughout the operation of the device, microwave source 18 operates at the center carrier frequency. As the scanning center, in the central carrier frequency A sweep frequency range is set up nearby, with the microwave frequency revolving around the center carrier frequency. Continuous scanning is performed, traversing the frequency points near the spin transition of the NV color center, thus completing the ODMR spectrum acquisition. Simultaneously, microwave source 18 operates at the center carrier frequency... Overlay low-frequency modulated signal (In this embodiment, 10kHz is used) to achieve amplitude modulation of the microwave carrier to obtain an frequency-modulated microwave signal. This modulation component is sent as a reference signal to the lock-in amplifier 16 for phase-sensitive demodulation to extract the first-order differential ODMR signal. The PID device 17 receives the demodulated signal output from the lock-in amplifier 16. With the center point of resonance As the target to be locked, the output feedback control quantity is sent back to the microwave source 18, which controls the center carrier frequency output by the microwave source 18. Closed-loop tracking is performed to keep the microwave operating frequency locked at the actual resonant point of the NV color center, thus achieving frequency locking. When external magnetic fields, stress, or temperature disturbances are present, the actual resonant point of the NV color center will deviate from its inherent center carrier frequency. The closed-loop circuit will correct the actual microwave frequency output by microwave source 18 in real time, following the deviation of the real spin resonance frequency.

[0087] The device simultaneously locks the resonant frequency through dual-channel independent frequency locking or time-division multiplexing single-channel frequency locking.

[0088] The device needs to be locked simultaneously. and In this embodiment, the two resonance points can be implemented in two ways. One is dual-channel independent frequency locking, which involves configuring two independent lock-in amplifiers 16, PID devices 17, and microwave sources 18, each simultaneously locking the frequency. and One type is suitable for applications requiring high response speed; the other is time-division multiplexing single-channel frequency locking, where a single device locks the frequency separately using alternating timing sequences. and Each parameter occupies 50% of the time, making it suitable for cost-sensitive applications. The dual-parameter update rate is half that of the single-path bandwidth.

[0089] The lock-in amplifier 16 or the back-end MCU continuously reads the two locked resonant frequencies. and The zero-field splitting parameter D and strain parameter E are obtained through inversion calculation. Then, the zero-field splitting parameter D is mapped to the absolute temperature T, and the strain parameter E is mapped to the stress. The refresh rate is consistent with the closed-loop bandwidth of the PID device 17, such as 100Hz-1kHz. The decoupling calculation formula is expressed as: ; .

[0090] The following detailed description of the embodiments of this application, using specific application examples, illustrates the entire process from ODMR spectrum acquisition to the final output of temperature and stress.

[0091] First, set the calibration parameters as shown in Table 1.

[0092] Table 1

[0093] Assuming the ambient temperature is T = 75℃, and the relative temperature to the reference temperature under calibration conditions... With a temperature increase of 50°C, the transverse stress σ = 200 MPa. The theoretical values ​​of the zero-field splitting parameter D and strain parameter E, calculated based on the calibration parameters, are expressed as follows: ; .

[0094] Then, the theoretical frequencies of the four ODMR peaks were calculated, as shown in Table 2.

[0095] Table 2

[0096] In actual measurements, the system noise SNR is approximately 35 dB, and the random error of frequency fitting is approximately ±5 kHz. Assume that four sets of measured resonance point frequencies (including noise) are extracted from the acquired ODMR characteristic spectrum: ; .

[0097] The bimodal method is used for calculation, that is, temperature and stress are calculated based on the extracted zero-field splitting parameter D and strain parameter E, respectively. Specifically: ; ; ; ; The final calculated stress deviated from the theoretical stress by +12MPa, which came from the error of noise in extracting E by ±5kHz.

[0098] The four-peak overdetermined method (six-peak physical splitting) was adopted. When performing nonlinear fitting calculations on temperature and stress (degenerate and merge into four observable characteristic peaks), the zero-field splitting parameter D and strain parameter E are first treated as free parameters to be determined. A residual vector is defined and a residual function is constructed, with each residual component expressed as: ; ; ; .

[0099] Then, the initial value for iteration is calculated based on the measured resonance point frequency of the inner double peak, expressed as: ; .

[0100] Then, iterative calculations are performed based on the Levenberg-Marquardt nonlinear least squares algorithm, with weights configured according to the signal-to-noise ratio of each characteristic peak, and the inner peaks set with their own signal-to-noise ratio as a benchmark. The outer peaks have doubled transition probability and higher signal-to-noise ratio due to degeneracy effects. Construct a weighted objective function based on the weights and residual components. After one iteration, the intermediate parameters D = 2866.301MHz and E = 0.050MHz were obtained. The objective function decreased from 0.0017 to 0.0004. After three iterations, the convergence criterion was met, and two convergent values ​​were obtained. The covariance matrix is ​​solved by iterating the Jacobian matrix, and its diagonal elements correspond to the variances of the parameters. , respectively characterizing the statistical fitting uncertainty of the two convergent values.

[0101] Substituting the convergence parameters into the calibration transformation formula for decoupling calculations, the initial calculation results for temperature and stress are obtained, as follows: ; Measurement accuracy ±4MPa.

[0102] The initial calculation results are then cross-validated based on the hyperfine coupling constant A, as shown below: ; The measured distance between the outer peaks is (2868.462-2864.138) / 2=2.162MHz. The difference between the two is 0.003MHz, which is less than the set threshold of 0.01MHz. After the verification is passed, the above temperature and stress are output as the final measurement results. If the difference between the two exceeds the set threshold, the spectrum data is determined to be abnormal and the re-acquisition process is triggered.

[0103] As shown in the above calculations, the traditional bimodal method only uses the two inner characteristic peaks to solve for parameters. In this embodiment, under the same noise conditions, the stress measurement error is reduced from ±12MPa to ±4MPa, improving the measurement accuracy by approximately three times. This embodiment introduces redundant observation information using a multi-peak overdetermined equation system and combines weighted least squares fitting to suppress random noise. Simultaneously, it utilizes the inherent hyperfine coupling constant of the NV system as an internal frequency scale, enabling self-verification of results without an external reference source. This effectively suppresses measurement errors caused by peak-finding bias, device frequency drift, and optical path noise, achieving high-precision synchronous decoupled detection of temperature and stress in a zero-field environment.

[0104] Please see Figure 3 The diagram shows the energy level structure and transition frequencies of the ground triplet state of the diamond NV center under zero magnetic field, illustrating the energy level splitting and ODMR signal of the electronic spin energy level of the diamond NV center under strain. Figure 3 The vertical axis represents energy levels, and the horizontal axis represents the direction of physical process evolution; |0> and |±1> represent the electron spins of the NV color centers, respectively. Spin state, for Energy reference level. When there is no strain disturbance, i.e., strain E=0. and Energy level degeneracy, the two energy levels coincide, energy level value Where D is the zero-field splitting parameter, and D is the energy level spacing between the |0> level and the degenerate |±1> level. The strain term is removed when strain exists, i.e., E≠0. The energy level degeneracy occurs when the originally degenerate |±1> energy level splits into two energy levels, DE and D+E. The energy level difference between the two split energy levels is 2E, which is directly determined by the strain parameter E.

[0105] Figure 3 The right side shows the corresponding ODMR (Optically Probemed Magnetic Resonance) signal, with two resonance absorption peaks, corresponding to the transitions of the two split energy levels. The peak positions are denoted as follows: , The frequency interval between the two resonance peaks is equal to 2E. By reading the frequency interval of the double peaks of the ODMR signal, the strain parameter E can be obtained; at the same time, the zero-field splitting parameter D carries temperature information. Combining parameters D and E, decoupled measurement of temperature and strain can be achieved.

[0106] Please see Figure 4 The image shows the ground state triplet state of a diamond NV color center under consideration. 14 A schematic diagram of the energy level structure and transition frequencies under the N-fine level splitting condition, illustrating the introduction of... 14 Following the N-nuclear spin hyperfine interaction, the energy level of the diamond NV color center is subjected to strain perturbation, resulting in energy level splitting and ODMR signals. Figure 4 The vertical axis represents energy levels, and the horizontal axis represents the physical evolution process; |0> and |±1> correspond to the electron spins of the NV color centers, respectively. Spin state, for The energy reference of the energy level; where D is the zero-field splitting parameter, E is the strain parameter, and A is... 14 N-axis hyperfine coupling constant.

[0107] When there is no strain disturbance, i.e., strain E=0, electron spin Energy level degeneracy, energy level value The energy level spacing between the |0> energy level and the degenerate |±1> energy level is D. When there is strain E≠0, the strain effect and 14 Under the combined effect of the hyperfine coupling of the N-nucleus spins, the originally degenerate The energy level undergoes multiple splitting, forming five sets of energy levels, namely: The two energy levels corresponding to the subspace, namely The energy level difference between the two is 2E; and The four-level energy level corresponding to the subspace, because With consistent eigenvalues, energy level degeneracy occurs, namely: and .

[0108] Figure 4 The right side shows the corresponding ODMR spectrum signal, exhibiting a total of 4 resonance peaks. Among them, the signal originates from... The two sets of transitions in the subspace correspond to resonance peaks , The frequency interval between the two peaks is 2E, which directly reflects the strain parameter; the other two sets of resonance peaks come from... Superfine subspace. 14 The hyperfine coupling constant A of N is a known fixed constant. By reading multiple sets of resonance peaks in ODMR, the zero-field splitting parameter D and strain parameter E can be solved simultaneously. The zero-field splitting parameter D carries temperature information, and parameter E carries stress information, thus achieving decoupled and synchronous measurement of temperature and stress. At the same time, A can serve as an internal reference standard to verify the measurement results and improve measurement accuracy.

[0109] Please see Figure 5The image shown is a zero-field ODMR experimental spectral feature map captured in an embodiment of this application, demonstrating the measured ODMR spectrum of diamond NV centers. Figure 5 The horizontal axis represents the microwave frequency in MHz, and the vertical axis represents the voltage of the acquired fluorescence waveform in V. Four resonance depressions appear in the spectrum, corresponding to the NV color centers and... 14 Multiple spin transitions under N-nucleus spin coupling. The left and right sides show two sets of relatively deep resonance depressions, corresponding to... The transition signal in nuclear spin space; a set of double peaks appears in the middle position, corresponding to... Two resonance depressions are generated by strain-induced splitting of the nuclear spin space. The center frequency of each resonance depression corresponds to the energy level transition frequency. By reading the center frequencies of the four resonance depressions and combining them... 14 Given the axial hyperfine coupling constant A, the zero-field splitting parameter D and strain parameter E can be obtained by simultaneously solving the equations. The zero-field splitting parameter D reflects the temperature information to be measured, and the strain parameter E reflects the stress information to be measured, thus achieving synchronous decoupled measurement of temperature and stress. The measured spectrum verifies the feasibility of the multi-peak ODMR signal acquisition scheme.

[0110] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0111] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0112] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0113] Please see Figure 6 , Figure 6 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes: The processor 601 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 602 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 602 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 602 and is called and executed by the processor 601 using the methods described in the embodiments of this application. The input / output interface 603 is used to implement information input and output; The communication interface 604 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 605 transmits information between various components of the device (e.g., processor 601, memory 602, input / output interface 603, and communication interface 604); The processor 601, memory 602, input / output interface 603, and communication interface 604 are connected to each other within the device via bus 605.

[0114] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0115] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0116] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0117] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0118] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0119] This application provides a method and apparatus for synchronous decoupling of temperature and stress sensing based on diamond color centers. This scheme acquires fluorescence signals from NV color centers using a diamond probe, and performs differential photoelectric conversion in conjunction with a balanced photodetector. This effectively suppresses common-mode noise in the optical path, reduces measurement interference caused by light intensity fluctuations, and outputs a differential voltage signal with a better signal-to-noise ratio, providing a high-quality raw photoelectric signal for subsequent signal demodulation. In the phase-locked demodulation and closed-loop microwave control stages, a phase-sensitive demodulation of the differential voltage signal is performed using a lock-in amplifier to extract the first derivative differential spectrum signal of ODMR. A PID device, combined with the demodulated signal, forms a closed-loop feedback, adjusting the microwave frequency output by the microwave source in real time. This achieves automatic tracking of the microwave frequency to the NV color center resonance point, offsetting resonance point drift caused by environmental disturbances, ensuring that the microwave excitation is always aligned with the energy level resonance position, and avoiding offset errors caused by manual frequency sweeping. Based on closed-loop tracking, a high-resolution frequency sweep is performed to acquire the initial ODMR spectrum. The initial ODMR spectrum is then subjected to baseline correction, denoising, and coarse peak finding to remove interference from baseline drift and random noise, resulting in preprocessed spectral data to reduce the error probability in subsequent peak finding and fitting processes.

[0120] This application forms a complete chain from photoelectric acquisition, closed-loop microwave tracking, and spectral sampling preprocessing to quantum Hamiltonian modeling, weighted fitting of overdetermined equations, parameter uncertainty assessment, and built-in self-verification. Utilizing the multi-peak redundancy information brought about by hyperfine splitting, it achieves decoupled synchronous measurement of temperature and stress under zero-field conditions, effectively reducing single-parameter extraction errors. Relying on the internal hyperfine coupling constant, it completes result self-verification, automatically identifying and discarding degraded data, effectively combating optical path noise, frequency drift, and spectral distortion. This enables high-precision, high-reliability synchronous decoupled measurement of temperature and stress using a diamond NV color center sensor in a zero-field environment.

[0121] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0122] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0123] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0124] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0125] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for synchronously decoupled temperature and stress sensing based on diamond color centers, characterized in that, The method includes: Under zero-field conditions, laser excitation and microwave excitation are applied together to the NV color center of diamond, causing the NV color center to generate a fluorescence signal containing ODMR information; The laser excitation and the fluorescence signal are balanced and matched to obtain a differential voltage signal; The differential voltage signal is phase-sensitively demodulated with a low-frequency modulation signal of a preset frequency to obtain a demodulated signal. An initial ODMR spectrum is constructed by real-time sampling of the demodulated signal and the microwave frequency of the microwave excitation. The initial ODMR spectrum is updated by introducing a hyperfine interaction term to analyze the total spin Hamiltonian of the ground-state electrons, and the ODMR characteristic spectrum is obtained. The resonance frequency is extracted from the ODMR characteristic spectrum and the temperature and stress are obtained by iterative inversion and decoupling calculation. The initial ODMR spectrum is updated by introducing a hyperfine interaction term to analyze the total spin Hamiltonian of the ground-state electrons, resulting in the ODMR characteristic spectrum. Resonance frequencies are extracted from this ODMR characteristic spectrum, and temperature and stress are obtained through iterative inversion and decoupling calculations, including: Under zero-field conditions, the total spin Hamiltonian is calculated by introducing a hyperfine interaction term to update the initial ODMR spectrum and obtain the ODMR characteristic spectrum, and the resonance frequency is extracted from the ODMR characteristic spectrum. The total Hamiltonian matrix is ​​obtained based on the total spin Hamiltonian, and the total Hamiltonian matrix is ​​divided into blocks for dimensionality reduction based on different values ​​of nuclear spin projection to obtain sub-matrices corresponding to different nuclear spin projection values. Calculate the eigenvalues ​​corresponding to the submatrices respectively, and construct an overdetermined system of equations based on multiple sets of eigenvalues; Construct a residual vector for the overdetermined system of equations based on the eigenvalues ​​and the resonant point frequencies; The objective function is constructed based on the residual vector, and the objective function is iteratively solved using the least squares algorithm to obtain the relevant convergence value and covariance matrix. Decoupling calculations are performed based on the convergence value to obtain initial calculation results; The initial calculation results are verified based on the hyperfine coupling constant and the covariance matrix, and the final temperature and stress are output.

2. The method according to claim 1, characterized in that, After obtaining the demodulated signal, the process includes: Feedback control calculations are performed based on the correspondence between the resonant frequency of the NV color center, the center carrier frequency of the microwave excitation, and the demodulated signal to adaptively adjust the center carrier frequency, thereby obtaining the adjusted center carrier frequency. A frequency-modulated microwave signal is generated based on the adjusted center carrier frequency and the low-frequency modulation signal, and the frequency-modulated microwave signal is used as the microwave excitation to act on the NV color center.

3. The method according to claim 1, characterized in that, When constructing the residual vector, the eigenvalues ​​are converted into theoretical values ​​to obtain the theoretical resonance frequency, the resonance point frequency is used as the observed value, and the zero-field splitting parameter and strain parameter are used as unknowns to be solved. The difference between the observed value and the theoretical resonance frequency is calculated item by item, and the residual vector is obtained after arranging them in sequence.

4. The method according to claim 1, characterized in that, The weighting weights are determined based on the signal-to-noise ratios corresponding to each resonance characteristic peak, and the weighted sum of squared residuals is constructed as the objective function in combination with the residual vector.

5. The method according to claim 1, characterized in that, The convergence of the objective function is determined according to a preset convergence criterion, which includes a parameter update step size criterion and an objective function criterion. The iteration stops when either condition is met.

6. A temperature and stress synchronous decoupling sensing device based on diamond color centers, using the method described in any one of claims 1 to 5, characterized in that, The device includes a laser for outputting continuous-wave green laser light to a beam splitter; The beam splitter is used to output two signals. One signal is used as a laser optical path input to the diamond probe to excite the NV color center to generate red fluorescence. After being collected and filtered by the fluorescence collection device, a pure fluorescence signal is obtained and input to the balanced photodetector. The other signal is used as a reference optical path and directly input to the balanced photodetector. The balanced photodetector is used to output a differential voltage signal to the optoelectronic microwave transceiver module based on the reference optical path and the pure fluorescence signal; The optoelectronic microwave transceiver module includes a microwave antenna for radiating frequency-modulated microwave signals input to the diamond probe. When the microwave frequency of the frequency-modulated microwave signal matches the resonant frequency of the NV color center, the optoelectronic microwave transceiver module performs phase-sensitive demodulation based on the differential voltage signal and the internal low-frequency modulation signal to obtain a demodulated signal. The ODMR spectrum is obtained by real-time sampling of the demodulated signal and the microwave frequency, and the temperature and stress are obtained by inversion calculation based on the resonant point frequency in the ODMR spectrum.

7. The apparatus according to claim 6, characterized in that, The optoelectronic microwave transceiver module also includes a lock-in amplifier, a PID device, and a microwave source; The lock-in amplifier is used to perform phase-sensitive demodulation processing on the differential voltage signal and the low-frequency modulation signal to obtain a demodulated signal; it is also used to sample the demodulated signal and the microwave frequency in real time to obtain an ODMR spectrum, and to calculate the decoupled temperature and stress based on the resonant frequency in the ODMR spectrum. The PID device is used to receive the demodulated signal, and perform PID calculations according to the correspondence between the resonant frequency, the center carrier frequency and the demodulated signal, to adaptively adjust the center carrier frequency and output the corresponding feedback control voltage to the microwave source. The microwave source is used to generate a frequency-modulated microwave signal based on the center carrier frequency corresponding to the feedback control voltage and the internal low-frequency modulation signal, and output the frequency-modulated microwave signal to the microwave antenna; it is also used to output the low-frequency modulation signal to the lock-in amplifier.

8. The apparatus according to claim 7, characterized in that, In the PID device, PID calculation is performed based on the correspondence between the resonant frequency, the center carrier frequency, and the demodulated signal to adaptively adjust the center carrier frequency, including: When the center carrier frequency is greater than the resonant frequency, the corresponding demodulated signal is less than zero. The PID device reduces the center carrier frequency by lowering the feedback control voltage, thereby driving the center carrier frequency toward the resonant frequency. When the center carrier frequency is less than the resonant frequency, the corresponding demodulated signal is greater than zero, and the PID device increases the center carrier frequency by increasing the feedback control voltage. When the center carrier frequency is equal to the resonant frequency, the corresponding demodulation signal is equal to zero, and the PID device maintains the feedback control voltage unchanged to lock the center carrier frequency to the resonant frequency.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 5.

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