WO2022151869A1

WO2022151869A1 - Magnetic field measurement system and method, and storage medium

Info

Publication number: WO2022151869A1
Application number: PCT/CN2021/135776
Authority: WO
Inventors: 孙峰; 许克标; 石致富; 张伟
Original assignee: 国仪量子(合肥)技术有限公司
Priority date: 2021-01-13
Filing date: 2021-12-06
Publication date: 2022-07-21
Also published as: CN114764131A; CN114764131B

Abstract

A magnetic field measurement system (10) and method, and a storage medium. The magnetic field measurement system (10) comprises: a measuring member (11), placed in an external magnetic field to be measured and comprising an NV color center; a light source component (12), generating a manipulation laser irradiating the measuring member (11) to cause the NV color center to generate fluorescence; a manipulation component (13), providing a microwave manipulation field for the measuring member (11) to change the intensity of the fluorescence of the NV color center; a radio frequency component (14), providing an externally modulated magnetic field for the measuring member (11) to modulate the intensity; a signal acquisition component (15), acquiring and preprocessing a fluorescence signal of the NV color center; and an upper computer (16), controlling the light source component (12) to generate the manipulation laser, controlling the manipulation component (13) to generate the microwave manipulation field of a first preset frequency, controlling the radio frequency component (14) to generate the externally modulated magnetic field of a second preset frequency and a first preset amplitude, and acquiring the fluorescence signal from the signal acquisition component (15) to obtain high-frequency odd harmonic amplitude of the externally modulated magnetic field so as to calculate the intensity of the external magnetic field to be measured. According to the magnetic field measurement system (10) and method and the storage medium, the magnetic field measurement range of the NV color center can be improved, and the intensity of the low-frequency external magnetic field to be measured can be accurately measured.

Description

Magnetic field measurement system, method and storage medium

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to the Chinese Patent Application No. 202110044158.9, filed on Jan. 13, 2021, and entitled “Magnetic Field Measurement System, Method, and Storage Medium”, the entire contents of which are incorporated in this disclosure by reference.

technical field

The present disclosure relates to the technical field of magnetic measurement, and in particular, to a magnetic field measurement system, method, and storage medium.

Background technique

In the related art, a microwave can be applied to the NV color center, and the microwave will affect the electron spin state of the NV color center, thereby changing the fluorescence intensity of the NV color center; and then add an external magnetic field to be measured to the NV color center, The applied magnetic field to be measured will split the energy level of the NV color center, resulting in two fluorescence intensity peaks. Therefore, the externally applied magnetic field to be measured is measured by detecting the change of the fluorescence intensity of the NV color center after the externally applied microwave and the applied externally applied magnetic field to be measured. However, the magnetic measurement technology in the related art has a problem that the measurement range is low.

SUMMARY OF THE INVENTION

The magnetic field measurement system, method and storage medium can improve the magnetic field measurement range of the NV color center and achieve accurate measurement of the intensity of the low-frequency external magnetic field to be measured.

In a first aspect, the present disclosure proposes a magnetic field measurement system, comprising a measurement element placed in an external magnetic field to be measured, the measurement element including an NV color center; a light source assembly for generating illumination A manipulation laser of the measuring piece to make the NV color center generate fluorescence; a manipulation component, which is used to provide a microwave manipulation field for the measuring piece to change the fluorescence intensity of the NV color center; a radio frequency component , the radio frequency component is used to provide an externally modulated magnetic field for the measuring element to modulate the fluorescence intensity of the NV color center; a signal acquisition component is used to collect and preprocess the fluorescence of the NV color center signal; a host computer, the host computer is respectively connected with the light source assembly, the control assembly, the radio frequency assembly and the signal acquisition assembly, the host computer is used to control the light source assembly to generate the manipulation laser, Controlling the manipulation component to generate a microwave manipulation field of a first preset frequency, and controlling the radio frequency component to generate an externally modulated magnetic field of a second preset frequency and a first preset amplitude, and acquiring the fluorescence from the signal acquisition component signal, and obtain the high frequency odd harmonic amplitude of the external modulation magnetic field according to the fluorescence signal, and calculate the intensity of the external magnetic field to be measured according to the high frequency odd harmonic amplitude, wherein the first preset Let the frequency be the resonance frequency of the NV color center.

According to the magnetic field measurement system of the embodiment of the present disclosure, the magnetic field measurement range of the NV color center can be improved, so as to accurately measure the intensity of the low-frequency external magnetic field to be measured.

In a second aspect, the present disclosure provides a magnetic field measurement method, which is used in the above-mentioned magnetic field measurement system, and the magnetic field measurement system includes the following steps: controlling the manipulation component to provide a measurement element in an externally applied magnetic field to be measured. a microwave manipulation field of a first preset frequency, and control the radio frequency component to provide the measuring element with an externally modulated magnetic field of a second preset frequency and a first preset amplitude, wherein the first preset frequency is the Measure the resonance frequency of the NV color center in the component; obtain a fluorescence signal; obtain the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal; the strength of the magnetic field.

In the magnetic field measurement method of the embodiment of the present disclosure, a microwave manipulation field of a first preset frequency is provided to a measuring element in an external magnetic field to be measured by controlling a manipulation component, and a radio frequency component is controlled to provide a second preset frequency and a first frequency to the measuring element. An externally modulated magnetic field with a preset amplitude, wherein the first preset frequency is the resonance frequency of the NV color center in the measuring element; further, a fluorescence signal is obtained; so as to obtain the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescence signal; The high frequency odd harmonic amplitude calculates the strength of the applied magnetic field to be measured. The magnetic field measurement method can improve the magnetic field measurement range of the NV color center, and realize accurate measurement of the intensity of the low-frequency external magnetic field to be measured.

In a third aspect, the present disclosure proposes a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, implements the above-mentioned magnetic field measurement method.

Additional aspects and advantages of the present disclosure will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the present disclosure.

Description of drawings

The above and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a structural block diagram of a magnetic field measurement system according to a first embodiment of the present disclosure;

2 is a structural block diagram of a magnetic field measurement system according to a second embodiment of the present disclosure;

FIG. 3 is a working flow chart of a magnetic field measurement system of an example of the present disclosure;

4 is a flowchart of a magnetic field measurement method according to an embodiment of the present disclosure;

5 is a schematic diagram of a magnetic field measurement system of an example of the present disclosure.

Detailed ways

The embodiments of the present disclosure will be described in detail below. The embodiments described with reference to the accompanying drawings are exemplary, and the embodiments of the present disclosure will be described in detail below.

The magnetic field measurement system, method, and storage medium of embodiments of the present disclosure will be described below with reference to FIGS. 1-5 .

FIG. 1 is a structural block diagram of a magnetic field measurement system according to an embodiment of the present disclosure.

As shown in FIG. 1 , the magnetic field measurement system 10 includes a measurement component 11 , a light source component 12 , a manipulation component 13 , a radio frequency component 14 , a signal acquisition component 15 , and a host computer 16 .

The measuring element 11 is placed in the external magnetic field to be measured, and the measuring element 11 includes the NV color center; the light source assembly 12 is used to generate a manipulation laser that illuminates the measuring element 11, so that the NV color center generates fluorescence; the manipulation assembly 13 is used for measuring The component 11 provides a microwave manipulation field to change the fluorescence intensity of the NV color center; the radio frequency component 14 is used to provide an external modulation magnetic field for the measurement component 11 to modulate the fluorescence intensity of the NV color center; the signal acquisition component 15 is used to collect the NV color center. Fluorescence signal; the host computer 16 is respectively connected with the light source assembly 12, the control assembly 13, the radio frequency assembly 14 and the signal acquisition assembly 15, the host computer 16 is used to control the light source assembly 12 to generate the manipulation laser, and control the manipulation assembly 13 to generate the first preset frequency. The microwave manipulates the field, and controls the radio frequency component 14 to generate an externally modulated magnetic field with a second preset frequency and a first preset amplitude, and obtains a fluorescence signal from the signal acquisition component 15, and obtains the high-frequency odd order of the externally modulated magnetic field according to the fluorescence signal For the harmonic amplitude, the strength of the applied magnetic field to be measured is calculated according to the high frequency odd harmonic amplitude, wherein the first preset frequency is the resonance frequency of the NV color center.

Specifically, the measuring element 11 is a substance (for example, a diamond) containing NV color centers placed in an external magnetic field to be measured. The host computer 16 controls the light source assembly 12 to generate a manipulation laser and irradiates the measuring element 11 through the manipulation laser. At the same time, the host computer 16 controls the manipulation assembly 13 to generate a microwave manipulation field. Under the action, a fluorescent signal is generated. The signal collection component 15 collects the fluorescence signal and sends the fluorescence signal to the host computer 16 . The host computer 16 can judge whether the NV color center resonates according to the fluorescent signal, and if not, change the frequency of the microwave control field generated by the control assembly 13 until the frequency at which the NV color center can be judged to resonate is obtained, and this frequency is used as the first frequency. preset frequency.

Further, after controlling the manipulation component 13 to generate the microwave control field, the host computer 16 controls the radio frequency component 14 to generate an externally modulated magnetic field of the second preset frequency and the first preset amplitude. The external modulation magnetic field is superimposed with the external magnetic field to be measured, so as to realize the modulation of the fluorescence signal generated by the NV color center. The signal collection component 15 collects the modulated fluorescent signal, obtains the high frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal, and then calculates the intensity of the external magnetic field to be measured according to the high frequency odd harmonic amplitude.

Specifically, the corresponding relationship between the amplitude of the high-frequency odd harmonics of the applied modulation magnetic field and the intensity of the applied magnetic field to be measured can be obtained in advance; for example, the corresponding relationship between the amplitude of the high-frequency odd harmonics and the intensity of the applied magnetic field to be measured can be obtained by pre-measurement table, and then store the relation table in the upper computer 16 . Therefore, after obtaining the high frequency odd harmonic amplitude of the applied modulation magnetic field, the intensity of the applied magnetic field to be measured can be obtained according to the above corresponding relationship.

Optionally, the second preset frequency and the first preset amplitude can be preset; that is, the second preset frequency and the first preset amplitude of the externally modulated magnetic field can be set by the user according to their own estimated needs. , the default second preset frequency and first preset amplitude of the radio frequency component 14 may also be directly used, so that the frequency and amplitude of the magnetic field generated by the radio frequency component 14 will not change during the actual measurement process.

It should be noted that if the deviation between the external magnetic field to be measured and the microwave resonance frequency is too large, the fluorescence intensity generated by the NV color center cannot reflect the intensity change of the magnetic field. Therefore, the present disclosure utilizes an externally modulated magnetic field with a specified amplitude and frequency to obtain a fluorescent signal modulated by the magnetic field, and then obtains the high-frequency odd harmonic amplitude of the externally modulated magnetic field through the change of the light intensity of the fluorescent signal, so as to obtain the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the externally modulated magnetic field. The amplitude of the high frequency odd harmonics calculates the strength of the applied modulating magnetic field. Moreover, by calculating the intensity of the external modulation magnetic field according to the high frequency odd harmonic amplitude of the external modulation magnetic field, the magnetic field measurement system of the embodiment of the present disclosure can measure the magnetic field intensity higher than that of the external modulation magnetic field.

Preferably, before measuring the externally applied magnetic field to be measured, the frequency of the externally applied magnetic field to be measured may be acquired in advance. For example, the public information of the external magnetic field to be measured can be inquired in advance (for example, the magnetic field generated by the current in the power grid whose frequency is fixed at 50 Hz); or, a corresponding sensor can be set on the measuring element to generate the external modulation on the radio frequency component 14 Obtain the frequency of the applied magnetic field to be measured before the magnetic field.

As an example, when the above-mentioned upper computer 16 obtains the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal, it is specifically used to analyze the spectrum of the fluorescent signal by using the fast Fourier transform FFT algorithm to obtain the high-frequency odd harmonic magnitude. Further, the amplitude of the externally applied magnetic field to be measured can be obtained through the corresponding relationship between the amplitude of the high-frequency odd harmonics and the amplitude of the applied magnetic field to be measured.

It should be noted that the applied magnetic field to be measured in the embodiment of the present disclosure is a magnetic field whose frequency is less than the preset frequency threshold. Specifically, the proportional relationship between the harmonic amplitudes of different orders and the low-frequency magnetic field amplitudes may be as shown in FIG. 5 . The existing NV color center magnetic measurement method utilizes the relationship between the fundamental frequency harmonic and the external magnetic field to be measured, that is, the solid line in Fig. 5; by utilizing the characteristic that the amplitude of the fundamental frequency harmonic increases with the increase of the magnetic field within a certain range to measure the magnitude of the magnetic field. It can be seen from Figure 5 that with the increase of the magnetic field, the fundamental frequency harmonics appear obvious nonlinearity. When the magnetic field is large enough, the fundamental frequency harmonic amplitude will no longer increase with the increase of the magnetic field, and even decrease with the increase of the magnetic field. the accuracy of the measurement. Therefore, if the frequency of the externally applied magnetic field to be measured is less than the preset frequency threshold, the high-frequency odd-order harmonics of the externally modulated magnetic field can be obtained (for example, it can be the third harmonic or the fourth harmonic shown in FIG. Odd frequency harmonics replace the fundamental frequency harmonics for testing, thereby improving the range and accuracy of low-frequency magnetic field measurements.

In the embodiment of the present disclosure, as shown in FIG. 2 , the above-mentioned light source assembly 12 includes a laser 121 and a lens 122 . The laser 121 is used to generate laser light (eg, a laser light with a wavelength of 532 nm that can generate red fluorescence from the NV color center). The lens 122 is used for collimating and focusing the laser light generated by the laser 121 to form a control laser, and irradiating it to the preset position of the measuring element 11, thereby, the laser light generated by the laser 121 can be collected to the preset position, thereby improving the Measure the effect.

Referring to FIG. 2 , the above-mentioned control assembly 13 includes: a microwave source 131 , a power amplifier 132 , and a radiating member 133 . Among them, the microwave source 131 is connected to the host computer 16 for generating microwaves under the control of the host computer 16; the power amplifier 132 is used to amplify the microwaves to obtain the microwave manipulation field; the radiating element 133 is used to act on the microwave manipulation field to the measuring piece 11.

Referring to FIG. 2 , the above-mentioned radio frequency component 14 includes: a radio frequency signal generator 141 , a radio frequency amplifier 142 , and a Helmholtz coil 143 . The radio frequency signal generator 141 is connected to the host computer 16, and is used to generate radio frequency signals of the second preset frequency and the first preset amplitude under the control of the host computer 16; the radio frequency amplifier 142 is used to amplify the radio frequency signals. ; The Helmholtz coil 143 is used to generate an externally modulated magnetic field under the action of the amplified radio frequency signal.

Referring to FIG. 2 , the above-mentioned signal collection component 15 includes: a fluorescence collector 151 , a photodetector 152 , and a lock-in amplifier 153 . Among them, the fluorescence collector 151 is used to collect the fluorescence signal; the photodetector 152 is used to convert the fluorescence signal into an electrical signal; the lock-in amplifier 153 is connected to the upper computer 16, and the lock-in amplifier 153 is used to convert the electrical signal into a digital signal, The digital signal is demodulated, and the demodulated digital signal is uploaded to the upper computer 16, so as to realize the preprocessing of the fluorescent signal.

In an embodiment of the present disclosure, as shown in FIG. 3 , the above process of obtaining the first preset frequency may be:

S301 , controlling the manipulation component to generate a microwave manipulation field of a reference frequency.

S302: Obtain a fluorescence signal corresponding to the current microwave manipulation field.

S303, it is judged whether the resonance frequency can be obtained according to the fluorescence signal, if not, execute step S304, if yes, execute step S305.

S304, controlling the manipulation component to generate microwave manipulation fields of other frequencies.

S305, controlling the control component to output the microwave control field of the resonance frequency.

To sum up, the magnetic field measurement system of the embodiment of the present disclosure can improve the magnetic field measurement range of the NV color center, and realize the accurate measurement of the intensity of the low-frequency magnetic field.

FIG. 4 is a flowchart of a magnetic field measurement method according to an embodiment of the present disclosure.

In this embodiment, the magnetic field measurement method is used for the magnetic field measurement system described above.

As shown in Figure 4, the magnetic field measurement method includes the following steps:

S401 , controlling the manipulation component to provide a microwave manipulation field with a first preset frequency to a measuring component in the externally applied magnetic field to be measured, and controlling the radio frequency component to provide the measuring component with an externally modulated magnetic field of a second preset frequency and a first preset amplitude, Wherein, the first preset frequency is the resonance frequency of the NV color center in the measuring element.

Specifically, in this embodiment, the measuring element 11 is placed in the applied magnetic field to be measured, and the measuring element 11 includes the NV color center. The light source assembly 12 generates a steering laser to illuminate the measuring element 11 so that the NV color center generates fluorescence. Further, the manipulation component 13 provides the measuring component 11 with a microwave manipulation field to change the fluorescence intensity of the NV color center; the radio frequency component 14 provides an external modulation magnetic field for the measuring component 11 to modulate the fluorescence intensity of the NV color center.

Wherein, the steps of generating the microwave control field by the control component may be: controlling the control component 13 to generate a microwave control field with a reference frequency; obtaining a fluorescence signal corresponding to the current microwave control field; judging whether the resonance frequency can be obtained according to the fluorescence signal; if not, controlling The manipulation component 13 generates a microwave manipulation field of other frequencies, and returns to the step of acquiring the fluorescence signal corresponding to the current microwave manipulation field; if so, the manipulation component 13 is controlled to output the microwave manipulation field of the resonance frequency.

S402, acquiring a fluorescent signal.

S403, obtaining the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal.

Specifically, a fast Fourier transform (FFT) algorithm may be used to analyze the spectrum of the fluorescent signal to obtain the high frequency odd harmonic amplitude.

S404, calculating the intensity of the applied magnetic field to be measured according to the amplitude of the high-frequency odd-order harmonics.

In conclusion, the magnetic field measurement method of the embodiment of the present disclosure can improve the magnetic field measurement range of the NV color center, and realize accurate measurement of the intensity of the low-frequency external magnetic field to be measured.

Further, the present disclosure proposes a computer-readable storage medium.

In the embodiment of the present disclosure, a computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, the above-mentioned magnetic field measurement method is implemented.

The computer-readable storage medium of the embodiment of the present disclosure can improve the magnetic field measurement range of the NV color center when the computer program thereon is executed by the processor, so as to accurately measure the intensity of the low-frequency external magnetic field to be measured.

It should be noted that the logic and/or steps represented in the flowcharts or otherwise described herein, for example, may be considered as an ordered listing of executable instructions for implementing the logical functions, and may be embodied in any computer readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in combination with these used to execute a system, device or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or apparatus. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections with one or more wiring (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), Read Only Memory (ROM), Erasable Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program may be printed, as the paper or other medium may be optically scanned, for example, followed by editing, interpretation, or other suitable medium as necessary process to obtain the program electronically and then store it in computer memory.

It should be understood that portions of the present disclosure may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example.

Although embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and alterations can be made in these embodiments without departing from the principles and spirit of the present disclosure, The scope of the present disclosure is defined by the claims and their equivalents.

Claims

A magnetic field measurement system, comprising:

a measuring piece, the measuring piece is placed in an externally applied magnetic field to be measured, and the measuring piece includes an NV color center;

a light source assembly, the light source assembly is used to generate a manipulation laser for illuminating the measuring element, so that the NV color center generates fluorescence;

a manipulation component, the manipulation component is used to provide a microwave manipulation field for the measuring element, so as to change the fluorescence intensity of the NV color center;

a radio frequency component, the radio frequency component is used to provide an external modulation magnetic field for the measurement element to modulate the fluorescence intensity of the NV color center;

a signal acquisition component, the signal acquisition component is used to acquire and preprocess the fluorescence signal of the NV color center;

A host computer, the host computer is respectively connected with the light source assembly, the control assembly, the radio frequency assembly and the signal acquisition assembly, and the host computer is used to control the light source assembly to generate the manipulation laser, and control the the manipulation component generates a microwave manipulation field with a first preset frequency, and controls the radio frequency component to generate an externally modulated magnetic field with a second preset frequency and a first preset amplitude, and acquires the fluorescent signal from the signal acquisition component, and obtain the high frequency odd harmonic amplitude of the external modulation magnetic field according to the fluorescent signal, and calculate the intensity of the external magnetic field to be measured according to the high frequency odd harmonic amplitude, wherein the first preset frequency is the resonance frequency of the NV color center.
The magnetic field measurement system according to claim 1, wherein when the upper computer obtains the high-frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal, the upper computer is specifically used for:

The frequency spectrum of the fluorescent signal is analyzed using a Fast Fourier Transform FFT algorithm to obtain the high frequency odd harmonic amplitude.
The magnetic field measurement system according to claim 1, wherein before controlling the radio frequency component to generate the externally modulated magnetic field, the upper computer is further used for:

controlling the manipulation component to generate a microwave manipulation field of a reference frequency;

Obtain the fluorescence signal corresponding to the current microwave manipulation field;

Determine whether the resonance frequency can be obtained according to the fluorescent signal;

If not, controlling the manipulation component to generate microwave manipulation fields of other frequencies, and returning to the step of acquiring the fluorescence signal corresponding to the current microwave manipulation field;

If so, the manipulation component is controlled to output the microwave manipulation field of the resonance frequency.
The magnetic field measurement system according to claim 1, wherein the light source component comprises a laser and a lens, and the lens is used for collimating and focusing the laser light generated by the laser to form the manipulation laser, and Irradiate to the preset position of the measuring piece.
The magnetic field measurement system according to claim 1, wherein the manipulation component comprises:

a microwave source, which is connected to the host computer and used to generate microwaves under the control of the host computer;

a power amplifier, which is used for amplifying the microwave to obtain the microwave manipulation field;

a radiating part, the radiating part is used for applying the microwave manipulation field to the measuring part.
The magnetic field measurement system according to claim 1, wherein the radio frequency component comprises:

a radio frequency signal generator, the radio frequency signal generator is connected to the host computer, and is used for generating radio frequency signals of the second preset frequency and the first preset amplitude under the control of the host computer;

a radio frequency amplifier, which is used for amplifying the radio frequency signal;

A Helmholtz coil, the Helmholtz coil is used to generate the externally modulated magnetic field under the action of the amplified radio frequency signal.
The magnetic field measurement system according to claim 1, wherein the signal acquisition component comprises:

a fluorescence collector, the fluorescence collector is used to collect the fluorescence signal;

a photodetector for converting the fluorescent signal into an electrical signal;

a lock-in amplifier, which is connected to the host computer, and is used for converting the electrical signal into a digital signal, demodulating the digital signal, and converting the demodulated digital signal into a digital signal. The signal is uploaded to the upper computer.
A magnetic field measurement method, wherein the magnetic field measurement method is used in the magnetic field measurement system according to any one of claims 1-7, and the magnetic field measurement method comprises the following steps:

The control and manipulation component provides a microwave manipulation field with a first preset frequency to the measuring element in the external magnetic field to be measured, and controls the radio frequency assembly to provide the measuring element with an external modulation of a second preset frequency and a first preset amplitude Magnetic field, wherein, the first preset frequency is the resonance frequency of the NV color center in the measuring member;

Obtain fluorescent signal;

Obtaining the high frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal;

The intensity of the externally applied magnetic field to be measured is calculated according to the amplitude of the high-frequency odd-order harmonics.
The magnetic field measurement method according to claim 8, wherein the obtaining the high frequency odd harmonic amplitude of the externally modulated magnetic field according to the fluorescent signal comprises:

The frequency spectrum of the fluorescent signal is analyzed using a Fast Fourier Transform FFT algorithm to obtain the high frequency odd harmonic amplitude.
A computer-readable storage medium on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the magnetic field measurement method according to claim 8 or 9 is implemented.