Fluorescence data denoising demodulation method and related apparatus

Abstract

The application relates to the field of quantum precision measurement, and discloses a fluorescence data noise reduction demodulation method and a related device, which are applied to a process of sensing based on a diamond NV color center and using a photodetection magnetic resonance method. The fluorescence data noise reduction demodulation method provided by the scheme can move the center line of fluorescence digital signal data under different carrier frequencies to the vicinity of a zero axis, effectively reduces data offset, ensures the accuracy of quantum precision measurement, and the data used for calculating the zero axis offset value and the data used for filtering demodulation are fluorescence digital signal data under the same carrier frequency, so that the calculated zero axis offset value is very accurate and is not easily affected by external environment.

Description

Technical Field

[0001] This invention relates to the field of quantum precision measurement technology, specifically to a fluorescence data noise reduction and demodulation method, a fluorescence data noise reduction and demodulation device, a diamond NV center quantum device based on ODMR technology, and a storage medium. Background Technology

[0002] Nitrogen-vacancy (NV) centers in diamond are among the most studied solid-state spin center systems, exhibiting immense potential for applications in quantum precision measurement due to their millisecond-level spin coherence time at room temperature, atomic-level spatial resolution, and optically readable quantum properties. Quantum sensing technology based on NV centers is primarily achieved through the optically detected magnetic resonance (ODMR) method. Its core principle involves initializing the NV center's spin state to its ground state using a laser, manipulating it with a microwave field, and obtaining spin state information by detecting changes in fluorescence signal intensity, thereby enabling precise measurement of physical quantities such as magnetic fields, temperature, and electric fields.

[0003] In quantum sensing systems based on NV centers, a photodetector is used to acquire the photofluorescence signal generated by the diamond NV centers under the action of excitation light and a microwave field, and converts the optical signal into an analog electrical signal output. An analog-to-digital converter (ADC) acquires the analog signal output from the photodetector, converting the continuous analog signal into a discrete digital signal for subsequent processing such as data filtering, demodulation, and magnetic field calculation. In practical applications, to obtain the fluorescence response of the NV centers at different microwave frequencies, it is usually necessary to scan the microwave frequency or use frequency-modulated microwaves, with the ADC continuously acquiring the fluorescence signal during frequency changes.

[0004] However, during microwave frequency changes, the simulated fluorescence signal data acquired by the ADC exhibits a zero-axis shift. Specifically, as shown in the attached diagram... Figure 1 and Figure 2As shown, within different frequency ranges (the figure only controls the switching between two frequencies, f1 and f2, for illustration, where f1 = 2.83 GHz and f2 = 2.8711 GHz), the acquired analog data fluctuates around its respective center line, and these center lines are offset from the zero axis to varying degrees, none of them coinciding with the zero axis. This zero-axis offset phenomenon is related to several factors, including the transient response during microwave frequency switching, the operating characteristics of the photodetector, and the non-ideal characteristics of the ADC sampling circuit. When analog data with zero-axis offset directly enters subsequent signal processing stages such as filtering and phase-locked demodulation, the offset is introduced into the calculation process, leading to errors in the demodulation results, and thus affecting the accuracy and precision of the magnetic field measurement. Therefore, how to eliminate or suppress the zero-axis offset in the ADC acquired data and improve the accuracy of signal processing is an important problem to be solved in current NV color center quantum sensing technology. Summary of the Invention

[0005] This invention proposes a fluorescence data denoising and demodulation method, a fluorescence data denoising and demodulation device, a diamond NV center quantum device based on ODMR technology, and a storage medium to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A fluorescence data denoising and demodulation method, applied to a sensing process based on diamond NV centers and using photodetector magnetic resonance, includes: S1. Continuously acquire fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies. S2. Divide the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and preprocess the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: First, use the front-end data segment to perform mean calculation to obtain the zero-axis offset value; Then, the fluorescence digital signal data in the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data; S3. Perform real-time filtering and demodulation on the obtained preprocessed fluorescent digital signal data.

[0007] In a preferred design of the fluorescence data denoising and demodulation method described above, the signal duration of the front-end data segment used for averaging calculation at each carrier frequency is an integer number of microwave modulation cycles.

[0008] In a preferred design of the fluorescence data denoising and demodulation method described above, the signal duration of the preprocessed fluorescence digital signal data obtained at each carrier frequency is not less than the filtering duration.

[0009] In a preferred design of the fluorescence data denoising and demodulation method described above, the front-end data segment used for averaging calculation at each carrier frequency does not contain microwave switching transient interference data.

[0010] Another aspect of this application also introduces a fluorescence data noise reduction and demodulation device, applied to a process based on diamond NV color centers and using photodetector magnetic resonance sensing, comprising: Signal sampling module: continuously acquires fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies; Signal preprocessing module: Divides the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and performs preprocessing on the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: First, use the front-end data segment to perform mean calculation to obtain the zero-axis offset value; Then, the fluorescence digital signal data in the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data; Noise reduction and demodulation module: performs real-time filtering and demodulation on the acquired preprocessed fluorescent digital signal data.

[0011] In a preferred design of the fluorescence data noise reduction and demodulation device described above, in the signal preprocessing module, the signal duration of the front-end data segment used for averaging calculation at each carrier frequency is an integer number of microwave modulation cycles.

[0012] In a preferred design of the fluorescence data noise reduction and demodulation device described above, in the signal preprocessing module, the signal duration of the preprocessed fluorescence digital signal data obtained at each carrier frequency is not less than the filtering duration.

[0013] In a preferred design of the fluorescence data noise reduction and demodulation device described above, the front-end data segment used for averaging calculation in the signal preprocessing module does not contain microwave switching transient interference data for each carrier frequency.

[0014] Another aspect of this application also describes a diamond NV color center quantum device based on ODMR technology, comprising: Diamond NV color centers are diamond blocks containing ensemble NV color centers. The laser module is used to transmit excitation light to the diamond NV color center; A microwave module is used to radiate modulated microwaves to the diamond NV color center; The photoelectric detection module is used to collect the fluorescence generated by the diamond NV color center under the dual action of excitation light and modulated microwave; Processor, used for system control and data processing; The aforementioned diamond NV color center quantum device further includes: Several PID modules are used to track two pairs of spin resonant frequencies along at least one NV axis in the diamond NV center and give frequency adjustment signals in turn. The microwave module receives the frequency adjustment signals in turn and switches the carrier frequency to the corresponding spin resonant frequency. In the fluorescence data noise reduction and demodulation device described above, the sampling object of the signal sampling module is the fluorescence digital signal data output by the photoelectric detection module.

[0015] In a preferred design of the diamond NV color center quantum device described above, the signal duration of the front-end data segment is one microwave modulation cycle for each carrier frequency in the signal preprocessing module, and the signal duration of the back-end data segment is equal to one filtering duration.

[0016] In another aspect, this application also describes a storage medium storing a computer program that, when executed by data processing hardware, enables the operation of the fluorescence data noise reduction and demodulation method described above.

[0017] Compared with the prior art, the beneficial effects of the present invention are: the fluorescence data noise reduction and demodulation method proposed in this scheme can move the center line of fluorescence digital signal data at different carrier frequencies to near the zero axis, effectively reducing the data offset and ensuring the accuracy of quantum precision measurement. Moreover, the data used to calculate the zero axis offset value and the data used for filtering and demodulation in this scheme are fluorescence digital signal data at the same carrier frequency, so the calculated zero axis offset value is very accurate and not easily affected by the external environment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a frequency-time relationship diagram when the carrier switches between frequency f1 and frequency f2. Figure 2 To and Figure 1 Corresponding ADC sampling result diagram; Figure 3 This is a flowchart illustrating the fluorescence data noise reduction and demodulation method in Example 1; Figure 4 This is a system block diagram of the fluorescence data noise reduction and demodulation device in Example 2; Figure 5 This is a system block diagram of the diamond NV color center quantum device in Example 3; Figure 6 This is a schematic diagram of the hardware structure of the storage medium in Embodiment 4. Detailed Implementation

[0020] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, one or more embodiments are now described with reference to the accompanying drawings, wherein similar reference numerals are used throughout the text to refer to similar components. In the following description, numerous specific details are set forth for purposes of explanation in order to provide a more thorough understanding of one or more embodiments. However, it will be apparent that one or more embodiments may be practiced in various circumstances without these specific details, and the various embodiments may be combined with and referenced to each other without contradiction.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, 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.

[0023] Quantum sensing technology based on NV centers primarily achieves measurements through optically detected magnetic resonance (ODMR). The core measurement principle of ODMR is as follows: The electron spin ground state of the NV center is a spin triplet, containing three energy levels: m_s=0 and m_s=±1. Under zero magnetic field conditions, the m_s=±1 state is degenerate; however, under the influence of an external magnetic field, due to the Zeeman effect, the m_s=+1 and m_s=-1 states undergo energy level splitting, the magnitude of which is proportional to the strength of the external magnetic field. During measurement, the NV center is first irradiated with a green laser with a wavelength of approximately 532 nm to initialize the electron spin state to the m_s=0 ground state; then, a frequency-tunable microwave field is applied. When the microwave frequency precisely matches the energy level difference between the m_s=0 and m_s=±1 states, a resonant transition occurs in the NV center, and some electrons are flipped to the m_s=±1 state. Because the red fluorescence intensity emitted by the NV color center in the m_s=0 state is significantly stronger than that in the m_s=±1 state, the fluorescence intensity detected at the resonance frequency will decrease significantly, forming a resonance valley. The location of the resonance frequency can be determined by scanning the microwave frequency and monitoring the change in fluorescence intensity. Under the influence of an external magnetic field, the m_s=±1 state splits into two energy levels, corresponding to two spin resonance frequencies symmetrical about the central resonance frequency. The difference between these two frequencies is linearly related to the strength of the external magnetic field. By measuring the frequency difference and combining it with the electron spin gyromagnetic ratio, the magnitude of the external magnetic field can be accurately calculated.

[0024] In the aforementioned measurement process, a photodetector is used to acquire the photoluminescence signal generated by the diamond NV center under the action of excitation light and microwave field, and converts the optical signal into an analog electrical signal output. An analog-to-digital converter (ADC) acquires the analog signal output from the photodetector, converting the continuous analog signal into a discrete digital signal for subsequent data filtering, demodulation, and magnetic field calculation. In practical applications, to obtain the fluorescence response of the NV center at different microwave frequencies, it is usually necessary to scan the microwave frequency and use microwave modulation. The ADC continuously acquires the fluorescence signal during frequency changes.

[0025] However, during microwave frequency changes, the analog fluorescence signal acquired by the ADC exhibits a zero-axis offset. Specifically, within different frequency ranges, the acquired analog data fluctuates around its respective center line, with these center lines deviating to varying degrees from the zero axis. This zero-axis offset is related to several factors, including the transient response during microwave frequency switching, the operating characteristics of the photodetector, and the non-ideal characteristics of the ADC sampling circuit. When analog data with this zero-axis offset is directly input into subsequent signal processing stages such as filtering and phase-locked demodulation, the offset is introduced into the calculation process, leading to errors in the demodulation results and consequently affecting the accuracy and precision of the magnetic field measurement.

[0026] Considering the above problems, this solution proposes several solutions. Several embodiments are listed below to illustrate these solutions. Example 1

[0027] This example introduces a fluorescence data denoising and demodulation method applied to a sensing process based on diamond NV centers and using photodetector magnetic resonance, as shown in the attached figure. Figure 3 As shown, it includes steps S1-S3, wherein: S1. Continuously acquire fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies.

[0028] When sensing diamond NV centers based on the ODMR method, the fluorescence signal generated by the diamond NV centers is selected to be collected by a photodetector and converted from an optical signal into an analog electrical signal. The analog signal output by the photodetector is acquired by an ADC and the continuous analog signal is converted into a discrete digital signal for subsequent data filtering, demodulation and magnetic field calculation. This digital signal is the fluorescence digital signal data mentioned here.

[0029] The modulation-demodulation-based measurement scheme uses modulated microwaves to irradiate the diamond NV color center, and then demodulates the fluorescence signal based on the modulated signal. Typically, frequency modulation (FM) or amplitude modulation (AM) signals are used to modulate the carrier wave. The purpose is to shift the low-frequency measurement signal to a higher frequency through FM or AM modulation, which facilitates subsequent demodulation by a lock-in amplifier, effectively suppresses low-frequency noise and DC drift, and improves the signal-to-noise ratio.

[0030] Regarding the zero-axis offset mentioned earlier, it manifests as follows: during the acquisition time periods corresponding to different carrier frequencies, the fluorescent digital signal data fluctuates around its respective center line, and there is a different degree of offset between the center line and the zero axis at different carrier frequencies, as illustrated in the attached figure. Figure 1 The data in the middle are all deviating from the zero axis.

[0031] The zero-axis offset problem occurs when the frequency switches. Specifically, the fluorescence digital signal data that generates zero-axis offset is produced when at least two modulated microwaves with different carrier frequencies act on the diamond NV center. For example, in practical applications of NV center quantum sensing, to achieve real-time continuous measurement of dynamically changing magnetic fields, it is usually necessary to make the output frequency of the microwave source track the spin resonance frequency of the NV center in real time. For this purpose, a proportional-integral-derivative (PID) control module is often used to perform closed-loop adjustment of the microwave source output frequency (carrier frequency) to achieve automatic tracking and locking of the spin resonance frequency. In this scheme, only one type of modulated microwave with a carrier frequency acts on the diamond NV center at the same time. However, the calculation of external physical quantities requires fluorescence data at a pair of spin resonance frequencies within a short time. Therefore, the carrier frequency of the modulated microwave will switch back and forth between the pair of spin resonance frequencies. This inevitably leads to the acquisition of fluorescence digital signal data with zero-axis offset when the ADC is used to continuously acquire the output signal of the photodetector.

[0032] Of course, the application scenarios listed here are only one example of the applicable scenarios for the method proposed in this solution. Other scenarios that meet the same problem can also use the method proposed in this solution. For example, in some fixed-frequency measurement schemes, the carrier frequency of the modulated microwave will switch rapidly between two preset fixed frequency points. These two frequency points are usually set at positions with large slopes on both sides of the spin resonance peak of the NV color center. When the external magnetic field changes, the spin resonance frequency of the NV color center will shift, causing the position of the resonance peak relative to the two fixed carrier frequency points to change, thereby changing the difference in fluorescence response at the two frequency points. By demodulating this difference signal, the current position of the spin resonance frequency can be calculated in reverse, thereby obtaining the magnetic field value. In this scheme, the carrier frequency of the modulated microwave is a preset fixed value that does not change in real time with the magnetic field. Instead, the shift of the resonance frequency is passively sensed by the differential response of the fluorescence signal at the two frequencies. This is different from the aforementioned scheme where the PID control module tracks and locks the resonance frequency in real time, but the noise reduction and demodulation method of the fluorescence data recorded in this scheme is also applicable.

[0033] S2. Divide the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and preprocess the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: - First, use the front-end data segment to perform mean calculation to obtain the zero axis offset value; -Then, the fluorescence digital signal data in the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data.

[0034] Step S2 is the key step in solving the aforementioned zero-axis offset problem. Since the fluorescent digital signal data at different carrier frequencies have different zero-axis offsets, it is necessary to preprocess the data at each carrier frequency separately to eliminate their respective zero-axis offsets.

[0035] Specifically, after obtaining the fluorescence digital signal data at a certain carrier frequency, it is preferable to first delete the transient interference data caused by microwave frequency switching. At the instant the carrier frequency of the modulating microwave switches, the microwave source output is not yet stable, which may cause abnormal fluctuations in the fluorescence digital signal data. Deleting this data can improve the data quality of subsequent processing. An exemplary method for deleting transient interference data is as follows: Manual implementation method: First, determine the duration of the transition signal corresponding to the microwave switching transient interference data. This duration can be obtained by engineers through observation and experience of the actual signal. Then, set a time threshold slightly longer than the duration of the transition signal. Add this time threshold to the microwave switching time point to obtain the starting time point for the average calculation. Finally, select the front-end data segment from this starting time point to skip the microwave switching transient interference data and ensure the data quality of the front-end data segment.

[0036] Automatic implementation: After microwave frequency switching, the signal variance or standard deviation within a sliding time window is automatically calculated. When the variance or standard deviation exceeds a preset threshold, the data within that time period is determined to be transient interference data. When the variance or standard deviation drops below the preset threshold and remains stable, the transient interference data is determined to have ended, and this moment is the starting point for the mean calculation. This method requires no manual intervention and can automatically identify and delete transient interference data.

[0037] After deleting transient interference data (or skipping this step), the fluorescent digital signal data is divided into a front-end data segment and a back-end data segment in chronological order. The front-end data segment is used to calculate the zero-axis offset value at the carrier frequency. Preferably, its signal duration can be set to the duration of an integer number of modulation signal periods. This is because the fluorescent digital signal contains a modulation signal component. When the data segment covers an integer number of modulation periods, the positive and negative half-cycles of the modulation signal component can cancel each other out, thereby extracting the DC offset component, i.e., the zero-axis offset value, more accurately. This principle is similar to how an integer number of periods is needed to obtain the true intermediate value when averaging a sine signal. Of course, in practical applications, a data segment with a non-integer number of modulation periods can also be used to calculate the zero-axis offset value. Although the accuracy may be reduced, it is still applicable in scenarios where the accuracy requirement for the offset value is not high. The signal duration of the front-end data segment can, for example, be one or more modulation periods. When the duration is multiple modulation periods, the averaging operation of multiple data segments can reduce random errors and improve the accuracy of the zero-axis offset value.

[0038] The back-end data segment carries the fluorescence signal data that needs to be further processed. After the front-end data segment calculates the zero-axis offset value, each fluorescence digital signal data point in the back-end data segment is immediately subtracted from this zero-axis offset value. This corrects the centerline of the fluorescence digital signal data at the carrier frequency to the zero-axis position, resulting in preprocessed fluorescence digital signal data. The subtracted data points are then immediately sent to subsequent filtering and demodulation programs for processing, without waiting for the entire back-end data segment to complete acquisition, effectively ensuring the real-time performance of the detection.

[0039] Regarding the signal duration of the back-end data segment (i.e., the preprocessed fluorescent digital signal data), preferably, it can be set to be no less than the signal duration required for filtering processing, so as to meet the data volume requirements of the filtering algorithm and ensure the filtering effect. Of course, in practical applications, the signal duration of the back-end data segment can also be flexibly set according to specific needs. For example, in the case of pursuing the limit of fast detection, the signal duration of the front-end data segment can be set to only one modulation cycle, and the signal duration of the back-end data segment can be set to be equal to one filtering duration, thereby maximizing the detection speed while ensuring the preprocessing effect.

[0040] To further improve the accuracy of the zero-axis offset value, a sliding window update method can be used to dynamically adjust the offset value, for example. Specifically, as fluorescent digital signal data is continuously acquired, the front-end data segment can slide backward over time, sliding an integer number of modulation cycles each time, and recalculating the zero-axis offset value. In engineering implementation, a pipelined parallel processing approach can be used, where the back-end data processing uses the latest available zero-axis offset value, while the front-end calculates the updated offset value. Both processes are performed in parallel, achieving dynamic updates of the offset value without blocking the data processing flow. Furthermore, for example, when there are occasional outliers in the data, the median can be used instead of the mean to calculate the zero-axis offset value. That is, all data points within the front-end data segment are sorted and the median value is taken. This method has good robustness to outliers and can avoid the influence of individual outlier data on the offset value calculation result. Of course, the offset value optimization schemes listed here are only some feasible methods in this step; other schemes that can improve the accuracy or anti-interference ability of the zero-axis offset value can also be applied to this step.

[0041] S3. Perform real-time filtering and demodulation on the obtained preprocessed fluorescent digital signal data.

[0042] Step S3 involves filtering and demodulating the preprocessed fluorescence digital signal data to extract the effective signal for magnetic field calculation. This step is a standard processing step in the NV color center quantum sensing measurement process, and its specific implementation can be selected and adjusted according to actual application requirements.

[0043] The purpose of filtering is to suppress noise components in the signal and improve the signal-to-noise ratio (SNR). For example, at the front end of the electrical link, a low-pass filter can be used to filter the preprocessed fluorescent digital signal data. The cutoff frequency of the filter can be set to, for example, several kilohertz to tens of kilohertz to suppress high-frequency noise. After demodulation, a low-pass filter can also be used to remove high-frequency harmonic components and noise generated during demodulation, retaining only the DC component. Of course, the filtering method is not limited to low-pass filtering; in practical applications, band-pass filtering, high-pass filtering, or other types of filters can be selected according to the signal characteristics. Furthermore, in the digital post-processing stage, composite filtering methods such as wavelet transform and adaptive filtering can be superimposed to further improve the SNR.

[0044] Regarding demodulation processing, its purpose is to extract the response component related to the modulated signal from the modulated fluorescence signal. Taking frequency-modulated microwave as an example, the carrier frequency of the modulating microwave can be set around the zero-field splitting frequency of the NV color center (approximately 2.87 GHz), specifically falling within the linear region of the ODMR spectrum (e.g., 2.85-2.89 GHz) to obtain a larger demodulation slope. The modulation frequency can be set in the range of hundreds of hertz to thousands of hertz, preferably around 1 kHz, to balance noise suppression and response speed. Of course, the above parameters and methods are only examples, and can be flexibly adjusted according to specific measurement requirements and hardware conditions in practical applications.

[0045] The timing relationship between filtering and demodulation can be exemplified as follows: first, the preprocessed fluorescent digital signal data is filtered, and then demodulated. The resulting DC voltage signal can be directly used for magnetic field inversion calculations. Of course, the specific order and combination of filtering and demodulation can be adjusted according to the actual scheme.

[0046] Of course, the filtering and demodulation parameters, methods and procedures listed here are only examples, and other schemes that can achieve signal filtering and demodulation can also be applied to this step. Example 2

[0047] Corresponding to Example 1, this example proposes a corresponding fluorescence data noise reduction and demodulation device, applied to a process based on diamond NV color centers and using photodetector magnetic resonance (PDM) for sensing. See Appendix. Figure 4 It includes a signal sampling module, a signal preprocessing module, and a noise reduction and demodulation module.

[0048] In this example, the signal sampling module is used to continuously acquire fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies.

[0049] The signal sampling module is one of the core components of this device. Its function is to realize the continuous acquisition of fluorescent digital signal data and ensure that the carrier frequency of the modulated microwave switches between at least two different frequencies.

[0050] For example, the signal sampling module may include an ADC (Analog-to-Digital Converter) and its control unit as necessary components. The ADC is used to convert the input analog electrical signal into a discrete digital signal, and its control unit is used to control the sampling timing, data transmission, and other operations of the ADC. For example, the sampling rate of the ADC can be set to the range of several kilohertz to several megahertz, preferably several hundred kilohertz to several megahertz, to meet the acquisition requirements of NV color center fluorescence signals; the resolution of the ADC can be, for example, 12-bit, 14-bit, or 16-bit, preferably 16-bit, to improve sampling accuracy. For example, the ADC can be implemented using a main control chip with integrated ADC, such as the STM32H750VBT6. This type of chip integrates multiple high-precision SAR-ADCs and supports features such as buffering, DMA (Direct Memory Access), and hardware oversampling, enabling high-speed analog signal acquisition.

[0051] For example, the signal sampling module may further include a photodetector. The photodetector receives the fluorescence signal generated by the diamond NV color center and converts the optical signal into an analog electrical signal output. For example, the photodetector may be a photomultiplier tube (PMT), an avalanche photodiode (APD), a multi-pixel photon counter (MPPC / SiPM), or a photodiode (PD). Preferably, for the fluorescence signal emitted by the NV color center (wavelength range of approximately 600-850 nm), a photodetector with high quantum efficiency corresponding to this wavelength range can be used. For example, a photomultiplier tube has a gain of up to 10^6 to 10^7 times, suitable for detecting extremely weak fluorescence signals; an avalanche photodiode has a fast response speed (nanosecond level), suitable for scenarios requiring fast time-resolved measurements. Of course, the type and parameters of the photodetector can be flexibly selected based on factors such as the actual fluorescence signal intensity, measurement accuracy requirements, and cost.

[0052] Exemplarily, the signal sampling module may further include a microwave source. The microwave source generates a modulated microwave signal and radiates it to the diamond NV center via an antenna or microwave transmission line. Exemplarily, the output frequency range of the microwave source may cover approximately 2.0 GHz to 3.5 GHz, preferably approximately 2.7 GHz to 3.1 GHz, to cover the zero-field splitting frequency (approximately 2.87 GHz) and the linear region of the ODMR spectrum of the NV center. Exemplarily, the microwave source may support frequency modulation (FM) or amplitude modulation (AM), with the modulation frequency exemplarily ranging from hundreds of hertz to thousands of hertz, preferably set around 1 kHz. Exemplarily, the microwave signal output by the microwave source may be amplified by a power amplifier and radiated to the diamond NV center via a microwave transmission structure such as an antenna or copper wire.

[0053] For example, the signal sampling module may further include a PID (Proportional-Integral-Derivative) control module. The PID control module is used to perform closed-loop regulation of the microwave source's output frequency, achieving automatic tracking and locking of the NV color center spin resonance frequency. Specifically, the PID control module adjusts the microwave source's carrier frequency in real time according to changes in the fluorescence signal, making the carrier frequency follow the changes in the NV color center spin resonance frequency, thereby achieving real-time continuous measurement of the dynamically changing magnetic field.

[0054] The interconnection and collaboration between the components are exemplarily as follows: A photodetector receives the fluorescence signal generated by the diamond NV color center, converts the optical signal into an analog electrical signal, which is then transmitted to an ADC for sampling. Under the control of the control unit, the ADC converts the continuous analog signal into discrete fluorescent digital signal data. A modulated microwave signal generated by a microwave source is amplified by a power amplifier and radiated to the diamond NV color center. The carrier frequency of the microwave source switches between at least two different frequencies. A PID control module (if included) is connected to the microwave source and adjusts the carrier frequency in real time. Of course, the connection method of the above components can be flexibly adjusted according to the actual system architecture.

[0055] Of course, the specific composition of the signal sampling module is not limited to the example above. Other combinations of components capable of continuous acquisition of fluorescent digital signal data and carrier frequency switching can also be applied to this device. For example, if the signal sampling module does not include a photodetector or microwave source, the module can be mounted as an independent sampling unit in an existing diamond NV color center device, which itself already includes components such as a photodetector and a microwave source.

[0056] In this example, the signal preprocessing module is used to divide the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and to preprocess the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: firstly, performing a mean operation on the front-end data segment to obtain a zero-axis offset value; then, subtracting the fluorescent digital signal data in the back-end data segment from the obtained zero-axis offset value to obtain the preprocessed fluorescent digital signal data.

[0057] The signal preprocessing module is a key component of this device to achieve zero-axis offset correction. Its function is to segment the fluorescent digital signal data and eliminate the zero-axis offset through mean calculation and difference correction.

[0058] For example, the signal preprocessing module may include a data processing unit and a storage unit as necessary components. The data processing unit is used to perform operations such as data segmentation, averaging, and subtraction; the storage unit is used to cache the received fluorescent digital signal data and intermediate results during the calculation process. For example, the data processing unit may be implemented using an FPGA (Field-Programmable Gate Array), DSP (Digital Signal Processor), ARM (Reduced Instruction Set Computer Microprocessor), or a high-performance microcontroller. Preferably, the data processing unit may be implemented using an FPGA, which has strong parallel processing capabilities and high real-time performance, making it suitable for processing high-speed acquired fluorescent digital signal data. For example, the FPGA may be a Xilinx ZYNQ series chip, which integrates FPGA logic resources and an ARM processor core, enabling hardware and software co-processing and providing both high-speed data acquisition and real-time signal processing capabilities. For example, the storage unit may be RAM (Random Access Memory) or an internal cache, used for temporarily storing front-end data segments, back-end data segments, and zero-axis offset values.

[0059] Regarding the implementation of the data segmentation function, the following method can be used as an example: The data processing unit divides the received fluorescent digital signal data into a front-end data segment and a back-end data segment in chronological order according to a preset segmentation rule. For example, the data processing unit can determine the duration of the front-end data segment based on the period parameter of the modulation signal, and the duration of the front-end data segment can be set to an integer number of modulation periods. For example, the data processing unit can determine the duration of the back-end data segment based on the duration parameter required for filtering processing. The segmentation parameters (such as the duration of the front-end data segment and the duration of the back-end data segment) can be externally configured or pre-stored in a storage unit. For example, if the modulation frequency is 1 kHz, the duration of one modulation period is 1 ms, and the front-end data segment can be set to an integer number of modulation periods within the range of 1 ms to 10 ms. The averaging function can be implemented as follows, for example: the data processing unit sums all the fluorescent digital signal data points in the front-end data segment, then divides by the number of data points to obtain the average result, i.e., the zero-axis offset value. For example, the averaging operation can be implemented using hardware logic circuits such as accumulators and dividers, or it can be executed in a microprocessor via software. Preferably, a pipelined accumulator can be used in an FPGA to implement high-speed averaging, thereby improving processing efficiency.

[0060] Regarding the implementation of the difference correction function, the following method can be used as an example: the data processing unit performs a subtraction operation on each fluorescent digital signal data point in the back-end data segment and the zero-axis offset value to obtain preprocessed fluorescent digital signal data. For example, the difference operation can be implemented by a subtractor circuit or executed by a software program. Preferably, the data processing unit can perform point-by-point difference processing, that is, it performs the difference operation and outputs it immediately after receiving each back-end data point, without waiting for the entire back-end data segment to be acquired, thus ensuring real-time performance.

[0061] For example, the signal preprocessing module may further include a transient interference data deletion unit. This unit is used to identify and delete transient interference data generated by microwave frequency switching. For example, the transient interference data deletion unit can be implemented using a time threshold judgment method: the data processing unit records the microwave switching time point, determines the starting time point for averaging calculation based on a preset time threshold, and selects the front-end data segment from this starting time point, thereby skipping transient interference data. For example, the transient interference data deletion unit can also be implemented using a variance or standard deviation judgment method: the data processing unit calculates the signal variance or standard deviation within a sliding time window, and when the variance or standard deviation exceeds a preset threshold, it is determined to be transient interference data; when the variance or standard deviation drops below the preset threshold and remains stable, it is determined that the transient interference data has ended.

[0062] For example, the signal preprocessing module may further include an offset value optimization unit. This unit is used to improve the accuracy of the zero-axis offset value. For example, the offset value optimization unit may be implemented using a sliding window update method: the data processing unit continuously updates the position of the front-end data segment as data acquisition progresses, and recalculates the zero-axis offset value. For example, the offset value optimization unit may also be implemented using a median calculation method: the data points within the front-end data segment are sorted and the median value is taken as the zero-axis offset value to improve the ability to resist outliers.

[0063] The interconnection and collaboration between the components are exemplarily as follows: The signal preprocessing module receives the fluorescence digital signal data output by the signal sampling module through a data interface. The data is first stored in a storage unit for buffering. The data processing unit reads the data from the storage unit and performs segmented processing. The front-end data segment is used for averaging to obtain the zero-axis offset value, and the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data. The preprocessed data is output to the noise reduction and demodulation module through a data interface. Of course, the connection method and data processing flow of the above components can be flexibly adjusted according to the actual system architecture.

[0064] Of course, the specific composition of the signal preprocessing module is not limited to the example above. Other combinations of components that can realize data segmentation, mean calculation, and difference correction can also be applied to this device.

[0065] In this example, the noise reduction and demodulation module is used to perform real-time filtering and demodulation on the acquired preprocessed fluorescent digital signal data. The noise reduction and demodulation module is an integral part of this device for signal filtering and demodulation processing. Its function is to filter the preprocessed fluorescent digital signal data to suppress noise and demodulate it to extract the effective signal.

[0066] For example, the noise reduction and demodulation module may include a filtering unit and a demodulation unit as necessary components. The filtering unit is used to filter the preprocessed fluorescent digital signal data to suppress noise components; the demodulation unit is used to demodulate the filtered signal to extract the response components related to the modulated signal.

[0067] Regarding the implementation of the filtering unit, a digital filter can be used, as an example. The digital filter can be, for example, a low-pass filter, a band-pass filter, a high-pass filter, or other types of filters. Preferably, a low-pass filter can be used to filter out high-frequency noise. For example, the cutoff frequency of the low-pass filter can be set to several kilohertz to tens of kilohertz to suppress high-frequency noise components. For example, the digital filter can be implemented using an FIR (Finite Impulse Response) filter or an IIR (Infinite Impulse Response) filter. Preferably, an FIR filter can be used in an FPGA or DSP, which has linear phase characteristics and low signal distortion. For example, the filtering unit may also include a demodulation filter to filter out high-frequency harmonic components and noise generated during demodulation, retaining only the DC component.

[0068] The demodulation unit can be implemented, for example, using a digital lock-in amplifier (LLP). The LLP demodulates the signal by multiplying the input signal and the reference signal, then using a low-pass filter to extract the component with the same frequency and phase as the reference signal. For example, the LLP can be implemented using an FPGA, with the reference signal generated by the data processing unit based on the modulation signal parameters. Alternatively, the demodulation unit can be implemented using correlation demodulation, square-law demodulation, or other demodulation methods.

[0069] For example, the noise reduction and demodulation module can use integrated chips such as the ZYNQ-7010 as core components. These chips integrate FPGA and ARM processor cores, and are equipped with high-sampling-rate ADCs and DACs, enabling high-speed sampling and output of analog and digital signals, as well as hardware and software collaborative processing. For example, such systems can achieve a sampling rate of up to 125 MS / s and a data transmission bandwidth of hundreds of MiB / s, featuring high integration, ease of operation, and high phase-locked loop accuracy.

[0070] For example, the noise reduction and demodulation module may further include a composite filtering unit. This unit is used to further improve the signal-to-noise ratio during the digital post-processing stage. For example, the composite filtering unit may employ wavelet transform, adaptive filtering, or other methods to further process the demodulated signal. For example, the composite filtering unit may automatically select filtering parameters based on signal characteristics to improve the filtering effect.

[0071] For example, the noise reduction and demodulation module may further include a signal output unit. This unit is used to output the demodulated DC voltage signal for subsequent magnetic field inversion calculations. For example, the signal output unit may use a DAC (digital-to-analog converter) to convert the digital signal into an analog voltage signal for output, or it may directly output a digital signal for use by a subsequent digital processing system.

[0072] The interconnection and collaboration between the components are exemplarily as follows: The noise reduction and demodulation module receives preprocessed fluorescent digital signal data output from the signal preprocessing module via a data interface. The filtering unit first filters the data to suppress noise. The filtered data is then input to the demodulation unit for demodulation. The demodulated DC signal is output through the signal output unit. For example, the filtering and demodulation units can be processed sequentially, i.e., filtering followed by demodulation; other processing sequences can also be used depending on the actual solution. Of course, the connection methods and processing flows of the above components can be flexibly adjusted according to the actual system architecture.

[0073] Of course, the specific composition of the noise reduction and demodulation module is not limited to the example above. Other combinations of components that can achieve signal filtering and demodulation functions can also be applied to this device. Example 3

[0074] This example introduces a diamond NV color center quantum device based on ODMR technology, as shown in the attached image. Figure 5 As shown, it includes a diamond NV color center 1, a laser module 2, a microwave module 3, a photoelectric detection module 4, a processor 5, several PID modules 6, and a fluorescence data noise reduction and demodulation device 7.

[0075] In this example, the diamond NV color center 1 is a diamond block containing an ensemble NV color center; the laser module 2 is used to transmit excitation light to the diamond NV color center; the microwave module 3 is used to radiate modulated microwaves to the diamond NV color center; the photodetector module 4 is used to collect the fluorescence generated by the diamond NV color center 1 under the dual action of excitation light and modulated microwave; the processor 5 is used for system control and data processing; several PID modules 6 are used to track two pairs of spin resonance frequencies along at least one NV axis in the diamond NV color center 1 and sequentially provide frequency adjustment signals, the microwave module 3 sequentially receives the frequency adjustment signals and switches the carrier frequency to the corresponding spin resonance frequency; the fluorescence data noise reduction and demodulation device 7 is a device with the same function as mentioned in the previous embodiment, wherein the sampling object of the signal sampling module is the fluorescence digital signal data output by the photodetector module 4.

[0076] The diamond NV color center 1 is the core sensing element of this device, and is a diamond block containing an ensemble of NV color centers. Exemplarily, the diamond NV color center 1 can be prepared by chemical vapor deposition (CVD) or high-temperature high-pressure (HPHT). Exemplarily, the size of the diamond block can be in the range of approximately 200 μm to 500 μm, preferably in the range of approximately 300 μm to 400 μm. Exemplarily, the NV concentration in the diamond NV color center 1 can be in the range of approximately 100 ppb to 1000 ppb (ppb is one part per billion), preferably in the range of approximately 100 ppb to 500 ppb, to achieve higher measurement sensitivity. Exemplarily, the crystal orientation of the diamond can be selected as {100} or {111}, preferably, in specific application scenarios where the magnetic field direction is fixed, the {100} or {111} crystal orientation can be selected to facilitate the angle design between the magnetic field direction and the NV axis. Of course, the specific parameters of diamond NV color center 1 can be flexibly selected according to actual application requirements.

[0077] Laser module 2 is used to transmit excitation light to the diamond NV center 1 to achieve spin polarization and fluorescence excitation of the NV center. For example, laser module 2 can use a green laser with a wavelength of approximately 532 nm, because the NV center has a strong absorption efficiency for light at a wavelength of 532 nm, enabling efficient spin polarization. For example, the power stability of the laser can be controlled within ±1% to reduce measurement errors caused by laser power fluctuations. For example, laser module 2 may also include optical components such as a focusing lens and a polarizing lens to improve beam quality and excitation efficiency. For example, the laser can be transmitted to the diamond NV center 1 via spatial light transmission or fiber optic transmission. If fiber optic transmission is used, laser module 2 may also include devices such as fiber optic couplers. For example, the diamond NV center 1 can be fixed to the end of the fiber or set up independently. Of course, the specific composition and optical path structure of laser module 2 can be flexibly designed according to actual application requirements. Naturally, the selection of the laser wavelength needs to comprehensively consider factors such as the absorption efficiency, fluorescence excitation efficiency, and charge state stability of the NV center.

[0078] Microwave module 3 is used to radiate modulated microwaves to the diamond NV center 1 to achieve manipulation and resonant excitation of the NV center's electron spin. Exemplarily, microwave module 3 may include components such as a microwave source, a power amplifier, a microwave switch, and a microwave antenna. Exemplarily, the output frequency range of the microwave source may cover approximately 2.0 GHz to 3.5 GHz, preferably approximately 2.7 GHz to 3.1 GHz, to cover the zero-field splitting frequency (approximately 2.87 GHz) and the linear region of the ODMR spectrum of the NV center. Exemplarily, the microwave source may support frequency modulation (FM) or amplitude modulation (AM), and the modulation frequency may exemplary be in the range of hundreds of hertz to thousands of hertz, preferably set around approximately 1 kHz. Exemplarily, the power amplifier is used to amplify the power of the microwave signal to meet the microwave field strength required for spin manipulation of the NV center. Exemplarily, the microwave switch is used to control the on / off state of the microwave signal to achieve pulsed microwave output. For example, the microwave antenna can be a microstrip antenna, a loop copper wire, or other types of microwave transmission structures. Preferably, a microstrip antenna can be used, which has the characteristics of compact structure and easy integration. Of course, the specific composition and structure of the microwave module 3 can be flexibly designed according to the actual application requirements.

[0079] The photodetector module 4 is used to collect the fluorescence generated by the diamond NV color center 1 under the dual action of excitation light and modulated microwave. Exemplarily, the photodetector module 4 may include a photodetector and an optical path collection structure. Exemplarily, the photodetector may be a photomultiplier tube (PMT), an avalanche photodiode (APD), a multi-pixel photon counter (MPPC / SiPM), or a photodiode (PD). Preferably, for the fluorescence signal emitted by the NV color center (wavelength range of approximately 600 nm to 850 nm), a photodetector with high quantum efficiency corresponding to this wavelength range can be used. Exemplarily, a photomultiplier tube has a gain of up to 10^6 to 10^7 times, suitable for detecting extremely weak fluorescence signals; an avalanche photodiode has a fast response speed (nanosecond level), suitable for scenarios requiring fast time-resolved measurements. Exemplarily, the optical path collection structure may include optical elements such as filters, lenses, and mirrors. Exemplarily, a filter is used to filter stray light (such as scattered light from the excitation light), allowing only light in the fluorescence band of the NV color center to pass through, thereby improving the signal-to-noise ratio. For example, lenses or mirrors can be used to improve fluorescence collection efficiency. For example, the fluorescence generated by the diamond NV color center 1 can be directly received by the photodetector via spatial light transmission, or it can be transmitted back via optical fiber and then separated and guided to the photodetector by optical elements such as a dichroic filter. Of course, the specific composition and optical path structure of the photodetector module 4 can be flexibly designed according to the actual application requirements.

[0080] Processor 5 is used for system control and data processing. Exemplarily, processor 5 can be implemented using an FPGA (Field-Programmable Gate Array), DSP (Digital Signal Processor), ARM (Reduced Instruction Set Computing Microprocessor), or a high-performance microcontroller. Exemplarily, the functions of processor 5 may include: control of laser module 2 (e.g., laser switching, power adjustment), control of microwave module 3 (e.g., frequency setting, modulation parameter setting), control of photoelectric detection module 4 (e.g., sampling parameter setting), control of PID module 6 (e.g., tracking parameter setting), as well as data acquisition, processing, storage, and communication. Exemplarily, processor 5 can run an embedded operating system or bare-metal program to achieve coordinated control and data flow management of the various modules. Exemplarily, processor 5 can interact with a host computer or external system via communication interfaces such as USB, serial port, or Ethernet. Of course, the specific type and functional configuration of processor 5 can be flexibly selected according to actual application requirements.

[0081] Several PID modules 6 are used to track two pairs of spin resonant frequencies along at least one NV axis in the diamond NV color center 1 and sequentially provide frequency adjustment signals. Exemplarily, the number of PID modules 6 depends on the number of NV axes to be tracked and the number of pairs of spin resonant frequencies. For example, in applications where only two spin resonant frequencies along one NV axis need to be tracked, one or two PID modules 6 can be used; in applications such as vector magnetic field measurement where eight spin resonant frequencies along all four NV axes need to be tracked, eight PID modules 6 can be used. Exemplarily, the PID modules 6 can be implemented in hardware, such as using analog circuits or digital hardware circuits (FPGA internal logic) to implement proportional-integral-derivative operations; exemplaryly, the PID modules 6 can also be implemented in software, such as running a PID control algorithm program in the processor 5. Preferably, FPGA hardware implementation can provide faster response speed and higher control accuracy. For example, the working process of PID module 6 is as follows: For a certain NV axis, there are two pairs of spin resonance frequencies (corresponding to the two energy levels m_s=+1 and m_s=-1). PID module 6 continuously adjusts the carrier frequency of the microwave source according to the feedback of the fluorescence signal, so that it locks on the two spin resonance frequencies in turn, thereby realizing the real-time continuous measurement of the dynamically changing magnetic field.

[0082] The fluorescence data denoising and demodulation device 7, which is functionally identical to the device mentioned in the previous embodiments, includes a signal sampling module, a signal preprocessing module, and a denoising and demodulation module. The signal sampling module samples the fluorescence digital signal data output by the photodetector module 4, and continuously acquires fluorescence digital signal data generated and converted based on the diamond NV color center 1. During the acquisition process, the carrier frequency of the microwave module 3 switches between at least two different frequencies under the control of the PID module 6. The signal preprocessing module preprocesses the fluorescence digital signal data to eliminate zero-axis offset. The denoising and demodulation module performs real-time filtering and demodulation on the preprocessed data. The specific composition and working principle of the fluorescence data denoising and demodulation device 7 are as described in the previous embodiments and will not be repeated here.

[0083] Overall Collaborative Relationship: For example, the collaborative relationship among the components of this device is as follows: Laser module 2 transmits excitation light to the diamond NV center 1, achieving spin polarization of the NV center electrons; Microwave module 3, under the control of PID module 6, radiates modulated microwaves to the diamond NV center 1, with the carrier frequency switching between paired spin resonant frequencies; the diamond NV center 1 generates fluorescence under the combined action of excitation light and modulated microwaves; Photodetector module 4 collects the fluorescence signal and converts it into an electrical signal; Fluorescence data noise reduction and demodulation device 7 samples, preprocesses, filters, and demodulates the electrical signal, outputting a demodulated signal; Processor 5 is responsible for the overall coordination control and data processing of the system. Of course, the above collaborative relationship can be flexibly adjusted according to the actual application scenario.

[0084] Based on the above embodiments, by way of example, in the signal preprocessing module, for each carrier frequency, the signal duration of the front-end data segment can be set to one microwave modulation period, and the signal duration of the back-end data segment can be set to be equal to one filtering duration.

[0085] This embodiment provides a preferred solution under extreme conditions, aiming to maximize measurement speed. Specifically, the signal duration of the front-end data segment is one microwave modulation cycle, which is the minimum data length required to accurately calculate the zero-axis offset using averaging. As mentioned earlier, the signal duration of the front-end data segment needs to be an integer number of modulation cycles to accurately extract the zero-axis offset value; one modulation cycle is the smallest unit that satisfies this condition. Further shortening the front-end data segment duration will compromise the accuracy of the zero-axis offset calculation. The signal duration of the back-end data segment is equal to one filtering duration, which is the minimum data length required for the filtering algorithm to function effectively. Further shortening the back-end data segment duration will significantly reduce the filtering effect, thereby affecting the quality of the demodulated signal.

[0086] In this extreme case, the total signal duration of the fluorescent digital signal data at the same carrier frequency is the sum of one modulation period and one filtering period, which is the shortest data length for effective preprocessing and filtering. Compared to front-end data segments using multiple modulation periods or back-end data segments with longer durations, this scheme can significantly shorten the data acquisition time at a single frequency, thereby effectively improving measurement speed.

[0087] For example, this extreme solution is suitable for applications with extremely high real-time requirements, such as AC current tracking and other scenarios where the external magnetic field changes rapidly. In these scenarios, the magnetic field changes rapidly, requiring the measurement system to have an extremely high response speed. In this case, the solution using the shortest data length can effectively capture the rapidly changing magnetic field signal. Of course, while improving the measurement speed, this solution may have slightly lower accuracy in calculating the zero-axis offset value compared to solutions using multiple modulation cycles due to the shorter front-end data segment. In practical applications, a trade-off between measurement speed and accuracy can be struck based on specific requirements. Example 4

[0088] Corresponding to the fluorescence data denoising and demodulation methods above, see attached... Figure 6 As shown, one embodiment of this application also proposes a storage medium 100, which can be a non-transitory computer-readable storage medium. Exemplarily, the storage medium 100 may include a hard disk, optical disk, USB flash drive, flash memory, magnetic storage, or other forms of non-transitory computer-readable storage medium. A computer program 101 is stored on the storage medium 100. When executed by data processing hardware, the computer program 101 is capable of implementing the operation of the fluorescence data denoising and demodulation method described above. The computer program 101 contains one or more computer-readable instructions that, when executed by a processor, can perform one or more steps according to the fluorescence data denoising and demodulation method described above.

[0089] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0090] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0091] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0092] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0093] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A fluorescence data denoising and demodulation method, applied to a process based on diamond NV centers and using photodetector magnetic resonance sensing, characterized in that, Include: S1. Continuously acquire fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies. S2. Divide the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and preprocess the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: First, use the front-end data segment to perform mean calculation to obtain the zero-axis offset value; Then, the fluorescence digital signal data in the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data; S3. Perform real-time filtering and demodulation on the obtained preprocessed fluorescent digital signal data.

2. The fluorescence data noise reduction and demodulation method according to claim 1, characterized in that, For each carrier frequency, the signal duration of the front-end data segment used for averaging is an integer number of microwave modulation cycles.

3. The fluorescence data noise reduction and demodulation method according to claim 1, characterized in that, For each carrier frequency, the signal duration of the preprocessed fluorescent digital signal data obtained is not less than the filtering duration.

4. The fluorescence data noise reduction and demodulation method according to claim 1, characterized in that, For each carrier frequency, the front-end data segment used for averaging does not include microwave switching transient interference data.

5. A fluorescence data noise reduction and demodulation device, applied to a process based on diamond NV color centers and using photodetector magnetic resonance sensing, characterized in that... Include: Signal sampling module: continuously acquires fluorescent digital signal data generated and converted based on diamond NV color centers, and during the acquisition process, the carrier frequency of the modulated microwave radiating the diamond NV color centers switches between at least two different frequencies; Signal preprocessing module: Divides the fluorescent digital signal data at each carrier frequency into a front-end data segment and a back-end data segment, and performs preprocessing on the fluorescent digital signal data at the same carrier frequency. The preprocessing includes: First, use the front-end data segment to perform mean calculation to obtain the zero-axis offset value; Then, the fluorescence digital signal data in the back-end data segment is subtracted from the zero-axis offset value to obtain the preprocessed fluorescence digital signal data; Noise reduction and demodulation module: performs real-time filtering and demodulation on the acquired preprocessed fluorescent digital signal data.

6. The fluorescence data noise reduction and demodulation device according to claim 5, characterized in that, In the signal preprocessing module, for each carrier frequency, the signal duration of the front-end data segment used for averaging is an integer number of microwave modulation cycles.

7. The fluorescence data noise reduction and demodulation device according to claim 5, characterized in that, In the signal preprocessing module, for each carrier frequency, the signal duration of the preprocessed fluorescent digital signal data is not less than the filtering duration.

8. The fluorescence data noise reduction and demodulation device according to claim 5, characterized in that, In the signal preprocessing module, the front-end data segment used for averaging calculation at each carrier frequency does not include microwave switching transient interference data.

9. A quantum device for diamond NV color centers based on ODMR technology, comprising: Diamond NV color centers are diamond blocks containing ensemble NV color centers. The laser module is used to transmit excitation light to the diamond NV color center; A microwave module is used to radiate modulated microwaves to the diamond NV color center; The photoelectric detection module is used to collect the fluorescence generated by the diamond NV color center under the dual action of excitation light and modulated microwave; Processor, used for system control and data processing; The diamond NV color center quantum device described above is characterized in that it further comprises: Several PID modules are used to track two pairs of spin resonant frequencies along at least one NV axis in the diamond NV center and give frequency adjustment signals in turn. The microwave module receives the frequency adjustment signals in turn and switches the carrier frequency to the corresponding spin resonant frequency. The fluorescence data noise reduction and demodulation device according to any one of claims 5-8, wherein the sampling object of the signal sampling module is the fluorescence digital signal data output by the photoelectric detection module.

10. The diamond NV color center quantum device according to claim 9, characterized in that, In the signal preprocessing module, for each carrier frequency, the signal duration of the front-end data segment is one microwave modulation cycle, and the signal duration of the back-end data segment is equal to one filtering duration.

11. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by data processing hardware, enables the operation of the fluorescence data noise reduction and demodulation method as described in any one of claims 1-4.

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