A multi-channel atomic magnetometer device

Abstract

The invention is applicable to the field of weak magnetic signal detection, and discloses a multi-channel atomic magnetometer device, comprising a laser module, a probe module and a signal processing module. The laser module is used to generate a multi-channel laser beam. The probe module comprises a plurality of probes, and the plurality of probes are arranged in one-to-one correspondence with the multi-channel laser beam. Each probe comprises an optical element assembly, an atomic gas chamber, a coil and a photoelectric detector. The coil is wound around the periphery of the atomic gas chamber. The laser beam passes through the respective corresponding atomic gas chambers after being adjusted by the optical element assembly, and the changes in light intensity are detected by the respective photoelectric detectors. The signal processing module is used to output a modulation signal to each coil, and to receive and process the detection signal output by each photoelectric detector to obtain a measured signal. The modulation signal frequencies of each coil are different and are not integer multiples of each other. The multi-channel atomic magnetometer device is more integrated and can realize high-sensitivity multi-channel weak magnetic signal measurement.

Description

Technical Field

[0001] The invention relates to the field of weak magnetic signal detection, and in particular to a multi-channel atomic magnetometer device suitable for brain magnetism measurement. Background Art

[0002] The activity of neurons in the brain generates a magnetic field. Detection of the brain's magnetic field is helpful for the diagnosis and tracing of diseases such as epilepsy, autism, and stroke. However, brain magnetism is very weak, about one billionth of the earth's magnetic field. Therefore, brain magnetism detection requires an extremely sensitive weak magnetic detector. Superconducting Quantum Interference Device (SQUID) has a sensitivity of 1fT / Hz. 1 / 2 With its ultra-high sensitivity, SQUID has been used in the development of magnetoencephalography (MEG) equipment since its introduction in the 1970s, and commercial products have been produced. By arranging the sensor array to cover the patient's entire head, it captures weak magnetic field signals from inside the brain and performs intracranial source tracing. However, since SQUID requires a liquid helium low-temperature environment to work, its cost and use cost are extremely high. At the same time, its large and bulky size, the patient's head cannot move during testing, and the sensor is too far away from the patient's scalp. These shortcomings limit the widespread application of SQUID-MEG. A new type of quantum magnetic sensor - Optically Pumped Magnetometers (OPM) based on Spin Exchange Relaxation Free Region (SERF) also has extremely high sensitivity, and its theoretical limit sensitivity can reach 2aT / Hz. 1 / 2 , and the SERF atomic magnetometer can work in a room temperature environment, does not require liquid helium, and can be miniaturized, which greatly reduces the cost. In addition, compared with SQUID, the small SERF atomic magnetometer can be detected close to the patient's scalp, thereby realizing wearable MEG measurement in a natural motion state, which brings many conveniences to clinical use.

[0003] Multi-channel atomic magnetometer signal acquisition is an important requirement for MEG measurement. Compared with single-channel atomic magnetometers, multi-channel atomic magnetometers can simultaneously collect biomagnetic signals from multiple locations of the patient, which is convenient for lesion tracing and disease analysis. At present, the method to achieve multi-channel readout is to connect multiple single-channel atomic magnetometers together. Each single-channel atomic magnetometer has a matching electronic control system and an independent laser to provide pump light. Each channel magnetometer is controlled by software to achieve multi-channel signal acquisition. When multiple sensors work together, sensors that are very close to each other will affect each other. This influence is called crosstalk. The existence of crosstalk makes the sensitivity of multiple single-channel atomic magnetometers working together lower than when working alone, which is not conducive to the dense arrangement of sensors and delays the MEG clinical application process of multi-channel atomic magnetometers. Summary of the invention

[0004] The object of the present invention is to provide a multi-channel atomic magnetometer device, which aims to solve the problems that the existing atomic magnetometer has low integration when realizing multi-channel readout and crosstalk is easy to occur during operation of the multi-channel atomic magnetometer.

[0005] To achieve the above object, the solution provided by the present invention is:

[0006] A multi-channel atomic magnetometer device comprises a laser module, a probe module and a signal processing module. The laser module is used to generate a multi-channel laser beam. The probe module comprises a plurality of probes, and the plurality of probes are arranged in a one-to-one correspondence with the multi-channel laser beams. Each of the probes comprises an optical element assembly, an atomic gas chamber, a coil and a photodetector. The coil is wound around the periphery of the atomic gas chamber. The laser beam passes through the respective corresponding atomic gas chamber after being adjusted by the optical element assembly, and the change of light intensity is detected by the respective photodetectors. The signal processing module is used to output a modulation signal to each of the coils, and to receive and process the detection signal output by each of the photodetectors to obtain a measured signal. The modulation signal frequencies of the respective coils are different and are not integer multiples of each other.

[0007] Preferably, the modulation frequency of one of the coils is represented as f0, the step size of the modulation signal frequency change is represented as Δf, and the modulation signal frequencies of the other coils are added or subtracted by multiples of Δf based on f0.

[0008] Preferably, the probe module includes eight probes, and the modulation signals of each coil are expressed as f1, f2, ..., f8, and f1 = f0, f2 = f0+Δf, f3 = f0+2Δf, f4 = f0+3Δf, f5 = f0+4Δf, f6 = f0-Δf, f7 = f0-2Δf, f8 = f0-3Δf.

[0009] Preferably, the signal processing module includes multiple transimpedance amplifiers, an FPGA control unit, a multi-channel input analog-to-digital converter, a multi-channel output digital-to-analog converter and a calculation module. The FPGA control unit includes a drive signal generating module and multiple phase-locked amplifiers. The drive signal generating module is used to output the modulated signal, and the modulated signal is applied to each of the coils after conversion by the multi-channel output digital-to-analog converter. The multiple transimpedance amplifiers, the multiple phase-locked amplifiers and the multiple probes are arranged in a one-to-one correspondence. The number of channels of the multi-channel input analog-to-digital converter and the number of channels of the multi-channel output digital-to-analog converter are the same as the number of probes. The multiple transimpedance amplifiers are used to receive the detection signals output by the multiple photodetectors and convert them into voltage signals. The multi-channel input analog-to-digital converter is used to receive the converted voltage signals and convert them into multi-channel digital signals and output them to the multiple phase-locked amplifiers for demodulation to obtain demodulated signals. The calculation module is used to calculate the amplitude of the input signal and the phase difference of the reference signal according to the demodulated signal, and output the measured signal.

[0010] Preferably, each of the phase-locked amplifiers comprises a pre-processing module, a phase-locked loop, a phase shifter, a first phase-sensitive detection module, a second phase-sensitive detection module and an amplifier, wherein the pre-processing module is used to receive the digital signal output by the multi-channel input analog-to-digital converter, and perform preliminary amplification and filtering processing on it, the phase-locked loop is used to process the reference signal to obtain the required frequency and phase, the reference signal of each of the phase-locked amplifiers corresponds to a sinusoidal signal with the same modulation signal frequency as each of the coils, the phase shifter is connected to the phase-locked loop, and is used to output a sinusoidal signal and a cosine signal with equal frequency and a phase difference of 90°, and the first phase-sensitive detection module is used to perform a cross-correlation operation on the sinusoidal signal and the digital signal output by the multi-channel input analog-to-digital converter to obtain a sin output signal R srs The second phase-sensitive detection module is used to perform a cross-correlation operation on the cosine signal and the digital signal output by the multi-channel input analog-to-digital converter to obtain a cosine output signal R src , the demodulated signal includes a sin output signal R srs and cos output signal R src The amplifier is provided with two, each for amplifying the sin output signal R srs and cos output signal R src , and output it to the calculation module.

[0011] Preferably, the pre-processing module comprises a pre-amplifier, a 50 Hz notch filter, a main amplifier and an anti-aliasing filter which are connected in sequence.

[0012] Preferably, the phase-locked loop includes a phase detector, a loop filter connected to the phase detector, and a voltage-controlled oscillator connected to the loop filter; the first phase-sensitive detection module and the second phase-sensitive detection module both include a multiplier and a low-pass filter connected to the multiplier.

[0013] The multi-channel atomic magnetometer device provided by the present invention can realize brain magnetism detection under natural motion state, and has important value for brain science and clinical disease diagnosis.

[0014] The multi-channel atomic magnetometer device of the present invention uses a laser to provide pump light for multiple probes of the probe module at the same time, realizes the integration of the multi-channel atomic magnetometer control system, realizes the multiplexing of lasers, avoids the use of multiple lasers, effectively reduces the cost of lasers, and ensures the signal consistency of pump light in multiple channels. In addition, the modulation signal frequencies output by the signal processing module to the coils of different probes are different, and are not integer multiples of each other, so that there is no same frequency and Nth harmonic signal interference between adjacent probes in the probe module, and the magnetic field frequencies of each channel are different. In the demodulation process, signals of other frequencies can be filtered out, and only the magnetic field signal to be measured is retained. Therefore, adjacent probes will not interfere with each other, achieving the purpose of suppressing crosstalk, thereby improving the detection accuracy of the multi-channel atomic magnetometer device and realizing high-sensitivity multi-channel magnetic signal measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0016] Figure 1 is a structural block diagram of a multi-channel atomic magnetometer device provided by an embodiment of the present invention;

[0017] Figure 2 is a structural block diagram of a lock-in amplifier provided in an embodiment of the present invention;

[0018] Figure 3 The present invention is a flowchart of a lock-in amplifier for signal demodulation.

[0019] Description of Figure Numbers:

[0020] 10. Laser module; 11. Laser; 12. Fiber-coupled optical path; 13. Fiber beam splitter; 20. Probe module; 21. Probe; 211. Optical element assembly; 212. Atomic gas chamber; 213. Coil; 214. Photodetector; 30. Signal processing module; 31. Transimpedance amplifier; 32. FPGA control unit; 321. Drive signal generation module; 322. Phase-locked amplifier; 3221. Pre-processing module; 3222. Phase-locked loop; 3223. Phase shifter; 3224. First phase-sensitive detection module; 3225. Second phase-sensitive detection module; 3226. Amplifier; 33. Multi-channel input analog-to-digital converter; 34. Multi-channel output digital-to-analog converter; 35. Calculation module. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0024] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] like Figures 1 to 3As shown, it is a multi-channel atomic magnetometer device of an embodiment of the present invention, which realizes high-sensitivity multi-channel magnetic signal measurement. The atomic magnetometer realizes measurement based on the spin polarization manipulation of alkali metal atoms. The atomic gas chamber 212 is the core component of the atomic magnetometer, which contains alkali metal atomic gas, buffer gas and quenching gas. After passing through the polarized alkali metal atoms, the light intensity of the laser beam emitted by the laser 11 will change and be detected by the photodetector 214. The change in light intensity reflects the change in the magnetic field, so the measured weak magnetic field signal can be obtained.

[0026] See also Figure 1-Figure 3 The multi-channel atomic magnetometer device of the embodiment of the present invention includes a laser module 10, a probe module 20 and a signal processing module 30. The laser module 10 is used to generate a multi-path laser beam to polarize the alkali metal atoms in the atomic gas chamber 212 in the probe module 20. The probe module 20 is used to detect the change of light intensity and output a detection signal. The signal processing module 30 is used to output a modulated signal to the probe module 20, and is used to process the detection signal output by the probe module 20 to obtain a measured signal.

[0027] The laser module 10 includes a laser 11, a fiber coupling optical path 12 and a fiber beam splitter 13 which are arranged in sequence. The laser module 10 uses one laser 11 to simultaneously provide pump light for multiple probes 21 of the probe module 20. The laser 11 outputs pump light, and the pump light is divided into multiple laser beams after passing through the fiber coupling optical path 12 and the fiber beam splitter 13.

[0028] The probe module 20 includes a plurality of probes 21, and the plurality of probes 21 are arranged in one-to-one correspondence with the plurality of laser beams. Each probe 21 includes an optical element assembly 211, an atomic gas chamber 212, a coil 213 and a photodetector (PD) 214. The optical element assembly 211, the atomic gas chamber 212 and the photodetector 214 are arranged in sequence, and the coil 213 is wound around the outer periphery of the atomic gas chamber 212. One laser beam enters one probe 21 to polarize the alkali metal atoms in the atomic gas chamber 212 in one probe 21. This process realizes the multiplexing of the laser 11, avoids the use of a plurality of lasers 11, and effectively reduces the cost of the laser 11 while also ensuring the signal consistency of the pump light in a plurality of channels.

[0029] Optionally, the coil 213 is a three-axis coil 213 corresponding to three directions perpendicular to each other.

[0030] The optical element assembly 211 includes a collimating lens, a linear polarizer, a reflector and a quarter wave plate arranged in sequence along the optical path. The laser beam emitted by the laser module 10 is collimated by the collimating lens and then incident on the linear polarizer. The linearly polarized light emitted by the linear polarizer is reflected by the reflector to the quarter wave plate and converted into circularly polarized light.

[0031] The signal processing module 30 is used to output a modulation signal to the probe module 20, and to process the detection signal output by the probe module 20 to obtain a measured signal. The frequencies of the modulation signals output by the signal processing module 30 to the coils 213 of different probes 21 are different, and are not integer multiples of each other. This arrangement ensures that there is no interference of the same frequency and Nth (N is a positive integer) harmonic signals between adjacent probes 21 in the probe module 20, and the magnetic field frequencies of each channel are different. In the demodulation process, signals of other frequencies can be filtered out, and only the magnetic field signal to be measured is retained. Therefore, adjacent probes 21 will not interfere with each other, thereby achieving the purpose of suppressing crosstalk.

[0032] Preferably, the modulation frequency of one of the coils 213 is represented as f0, the step size of the modulation signal frequency change is represented as Δf, and the modulation signal frequencies of the other coils 213 are added or subtracted by multiples of Δf on the basis of f0, and the multiples start to change from 1. By setting the ratio of the modulation signal amplitude to the frequency of each channel to be fixed, it is ensured that each probe works under the optimal modulation condition.

[0033] The signal processing module 30 includes multiple transimpedance amplifiers (TIA) 31, an FPGA control unit 32, a multi-channel input analog-to-digital converter (ADC) 33, a multi-channel output digital-to-analog converter (DAC) 34 and a calculation module 35. The FPGA control unit 32 includes a drive signal generating module 321 and multiple phase-locked amplifiers (LIA) 322. The drive signal generating module 322 outputs a coil drive signal, and the coil drive signal is converted into an analog signal through the multi-channel output digital-to-analog converter 34 as a modulation signal applied to each coil 213. Multiple transimpedance amplifiers 31, multiple phase-locked amplifiers 322 and multiple probes 21 are arranged in a one-to-one correspondence. The number of channels of the multi-channel input analog-to-digital converter 33 and the number of channels of the multi-channel output digital-to-analog converter 34 are the same as the number of probes 21. In the modulation state, after the multiple laser beams pass through their respective corresponding atomic gas chambers 212, their respective photodetectors 214 detect the change in light intensity, and convert this light signal into a current signal output, and then the current / voltage conversion is realized through the transimpedance amplifier 31. The final collected analog voltage signal reflects the information of the measured magnetic field. The collected analog signal is converted into a multi-channel digital signal output by the multi-channel input analog-to-digital converter 33, and sent to the phase-locked amplifier 322 for demodulation to obtain a demodulated signal. The calculation module 35 is used to calculate the amplitude of the input signal and the phase difference with the reference signal according to the demodulated signal, and output the measured signal.

[0034] Preferably, the phase-locked amplifier 322 is a dual phase-locked amplifier, each phase-locked amplifier 322 includes a pre-processing module 3221, a phase-locked loop 3222, a phase shifter 3223, a first phase-sensitive detection module 3224, a second phase-sensitive detection module 3225 and an amplifier 3226, the pre-processing module 3221 is used to receive the digital signal output by the multi-channel input analog-to-digital converter 33, and perform preliminary amplification and filtering processing on it, the phase-locked loop 3222 is used to process the reference signal to obtain the required frequency and phase, the reference signal of each phase-locked amplifier 322 corresponds to a sinusoidal signal of the same frequency as the modulation signal of each coil 213, the phase shifter 3223 is connected to the phase-locked loop 3222, and is used to output a sinusoidal signal and a cosine signal with equal frequency and a phase difference of 90°, and the first phase-sensitive detection module 3224 is used to perform cross-correlation operation on the sinusoidal signal and the digital signal output by the multi-channel input analog-to-digital converter 33 to obtain a sinusoidal output signal R srs The second phase-sensitive detection module 3225 is used to perform a cross-correlation operation on the cosine signal and the digital signal output by the multi-channel input analog-to-digital converter 33 to obtain a cosine output signal R src , sin output signal R srs and cos output signal R src That is, the demodulated signal. There are two amplifiers 3226, which are used to amplify the sin output signal R srs and cos output signal R src , and output to the calculation module 35.

[0035] It can be understood that the demodulation process is implemented in the phase-locked amplifier 322, which is a key step in crosstalk suppression. The phase-locked amplifier 322 is a weak signal detection method based on the cross-correlation method. Its core is the phase-sensitive detection technology, which uses a reference signal with the same frequency and fixed phase as the signal to be measured as a reference to filter out noise with a different frequency, thereby extracting useful signal components.

[0036] The dual-phase lock-in amplifier 322 does not need to repeatedly adjust the phase relationship between the reference signal and the detection signal, which can avoid adjustment errors and phase drift, save measurement time, and improve measurement accuracy.

[0037] Optionally, the pre-processing module 3221 includes a pre-amplifier, a 50Hz notch filter, a main amplifier and an anti-aliasing filter. The pre-amplifier and the main amplifier are both used to amplify the voltage signal of the detection signal. The 50Hz notch filter is used to suppress the interference of the industrial frequency signal. The anti-aliasing filter is equivalent to a low-pass filter for suppressing high-frequency signal interference. By setting the pre-processing module 3221, the measurement accuracy can be further improved.

[0038] Optionally, the phase-locked loop 3222 includes a phase detector PD, a loop filter connected to the phase detector PD, and a voltage-controlled oscillator connected to the loop filter. The phase detector detects the phase difference between the output signal of the voltage-controlled oscillator and the input reference signal and converts it into a voltage, which is then passed through a low-pass loop filter to form a control voltage of the voltage-controlled oscillator. The voltage-controlled oscillator is controlled to output a signal with a fixed phase difference with the input reference signal, thereby achieving automatic tracking of the output signal frequency to the input signal frequency.

[0039] Optionally, the first phase-sensitive detection module 3224 and the second phase-sensitive detection module 3225 have the same structure, both including a multiplier and a low-pass filter connected to the multiplier.

[0040] Preferably, the calculation module 35 calculates the amplitude U of the detection signal according to the demodulated signal. s The phase difference between the sum and the reference signal

[0041]

[0042]

[0043] The frequency of the detection signal is equal to the frequency of the reference signal, and the measured signal can be obtained by combining the amplitude, phase and frequency. The same operation is performed on multiple detection signals to demodulate the measured signal with the same frequency as the reference signal. The demodulated signal does not contain the same-frequency interference signal introduced by the modulation signal of the adjacent probe 21, so the crosstalk is effectively suppressed.

[0044] The multi-channel atomic magnetometer device of the embodiment of the present invention can realize brain magnetic detection under natural motion state, which has important value for brain science and clinical disease diagnosis. The multi-channel atomic magnetometer device of the present invention uses a laser 11 to provide pump light for multiple probes 21 of the probe module 20 at the same time, realizes the integration of the multi-channel atomic magnetometer control system, realizes the reuse of the laser 11, avoids the use of multiple lasers 11, and effectively reduces the cost of the laser 11 while ensuring the signal consistency of the pump light in multiple channels. Moreover, the frequencies of the modulation signals output by the signal processing module 30 to the coils 213 of different probes 21 are different, and are not integer multiples of each other, so that there is no interference of the same frequency and Nth harmonic signals between adjacent probes 21 in the probe module 20, and the magnetic field frequencies of each channel are different. In the demodulation process, the signal with different frequencies from the modulation signal can be filtered out, and only the magnetic field signal to be measured is retained, so the adjacent probes 21 will not interfere with each other, so as to achieve the purpose of suppressing crosstalk, thereby improving the detection accuracy of the multi-channel atomic magnetometer device and realizing high-sensitivity multi-channel magnetic signal measurement.

[0045] The following is an example of an eight-channel atomic magnetometer device. The eight-channel atomic magnetometer device probe module 20 includes eight probes 21, and a laser 11 is used to simultaneously provide pump light for the eight probes 21. Correspondingly, eight transimpedance amplifiers 31 are provided, eight lock-in amplifiers 322 are provided, the multi-channel input analog-to-digital converter 33 is an eight-channel input analog-to-digital converter, and the multi-channel output digital-to-analog converter 34 is an eight-channel output digital-to-analog converter.

[0046] For an eight-channel atomic magnetometer device, the modulation frequencies of the coils of the eight channels are set to f1 to f8 (taking single-axis measurement as an example), where f0 is the modulation frequency of the coil of one channel. Under the premise of a fixed modulation signal amplitude, f0 is the frequency corresponding to the modulation signal that makes the sensor most sensitive. The modulation frequencies of the remaining channels change slightly around this optimal modulation frequency. Δf is the step length of the modulation signal frequency change. The amplitude of the modulation signal also changes accordingly with the frequency. By setting the ratio of the modulation signal amplitude to the frequency of each channel to remain fixed, it is ensured that each sensor works under the optimal modulation condition. The modulation frequencies f1 to f8 of the eight channels are not equal to each other, and are not integer multiples of each other, respectively: f1 = f0, f2 = f0 + Δf, f3 = f0 + 2Δf, f4 = f0 + 3Δf, f5 = f0 + 4Δf, f6 = f0 - Δf, f7 = f0 - 2Δf, f8 = f0 - 3Δf.

[0047] Taking the demodulation process of one channel as an example, the process of signal demodulation in the lock-in amplifier 322 is as follows: Figure 3 As shown. The voltage signal output by the transimpedance amplifier 31 is converted into a digital discrete signal sequence after passing through the multi-channel input analog-to-digital converter 33. The FPGA control module generates a sinusoidal reference sequence, which outputs a sinusoidal signal and a cosine signal with equal frequency and a phase difference of 90° after passing through the phase shifter 3223. The two reference signals enter the first phase-sensitive detection module 3224 and the second phase-sensitive detection module 3225 respectively to perform cross-correlation operations with the detection signal to obtain two output sin output signals R srs and cos output signal R src , the input signal amplitude U can be calculated s The phase difference between the sum and the reference signal

[0048]

[0049]

[0050] The frequency of the detection signal is equal to the frequency of the reference signal, and the measured signal can be obtained by combining the amplitude, phase and frequency. The same operation is performed on the detection signals of the eight channels to demodulate the measured signal with the same frequency as the reference signal. The demodulated signal does not contain the same-frequency interference signal introduced by the modulation signal of the adjacent probe 21, so the crosstalk is effectively suppressed.

[0051] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A multi-channel atomic magnetometer device, characterized in that: It comprises a laser module, a probe module and a signal processing module, wherein the laser module is used to generate a multi-channel laser beam, the probe module comprises a plurality of probes, and the plurality of probes are arranged in a one-to-one correspondence with the multi-channel laser beams, each of the probes comprises an optical element assembly, an atomic gas chamber, a coil and a photodetector, the coil is wound around the atomic gas chamber, the laser beam passes through the respective corresponding atomic gas chamber after being adjusted by the optical element assembly, and the change of light intensity is detected by the respective photodetectors, the signal processing module is used to output a modulation signal to each of the coils, and to receive and process the detection signal output by each of the photodetectors to obtain a measured signal, and the modulation signal frequencies of the respective coils are different and are not integer multiples of each other; Where: The modulation signal frequency of one coil is expressed as , the step size of the modulation signal frequency change is expressed as , the control signal frequency of the other coils is Add or subtract based on multiples of; The probe module includes eight probes, and the modulation signal of each coil is expressed as , ,……, ,and = , = , = , = , = , = , = , = ; The signal processing module includes multiple transimpedance amplifiers, an FPGA control unit, a multi-channel input analog-to-digital converter, a multi-channel output digital-to-analog converter and a calculation module. The FPGA control unit includes a drive signal generating module and multiple phase-locked amplifiers. The drive signal generating module is used to output the modulation signal, and the modulation signal is applied to each coil after conversion by the multi-channel output digital-to-analog converter. The multiple transimpedance amplifiers, the multiple phase-locked amplifiers and the multiple probes are arranged in a one-to-one correspondence. The number of channels of the multi-channel input analog-to-digital converter and the number of channels of the multi-channel output digital-to-analog converter are the same as the number of probes. The multiple transimpedance amplifiers are used to receive the detection signals output by the multiple photodetectors and convert them into voltage signals. The multi-channel input analog-to-digital converter is used to receive the converted voltage signals and convert them into multi-channel digital signals and output them to the multiple phase-locked amplifiers for demodulation to obtain demodulated signals. The calculation module is used to calculate the amplitude of the input signal and the phase difference of the reference signal according to the demodulated signal, and output the measured signal.

2. The multi-channel atomic magnetometer device according to claim 1, characterized in that Each of the phase-locked amplifiers includes a pre-processing module, a phase-locked loop, a phase shifter, a first phase-sensitive detection module, a second phase-sensitive detection module and an amplifier. The pre-processing module is used to receive the digital signal output by the multi-channel input analog-to-digital converter, and perform preliminary amplification and filtering processing on it. The phase-locked loop is used to process the reference signal to obtain the required frequency and phase. The reference signal of each of the phase-locked amplifiers corresponds to a sinusoidal signal of the same frequency as the modulation signal of each coil. The phase shifter is connected to the phase-locked loop and is used to output a sinusoidal signal and a cosine signal with equal frequency and a phase difference of 90°. The first phase-sensitive detection module is used to perform a cross-correlation operation on the sinusoidal signal and the digital signal output by the multi-channel input analog-to-digital converter to obtain a sin output signal The second phase-sensitive detection module is used to perform a cross-correlation operation on the cosine signal and the digital signal output by the multi-channel input analog-to-digital converter to obtain a cosine output signal , the demodulated signal includes a sin output signal and cos output signal The amplifier is provided with two, each for amplifying the sin output signal and cos output signal , and output it to the calculation module.

3. The multi-channel atomic magnetometer device according to claim 2, characterized in that: The pre-processing module includes a pre-amplifier, a 50 Hz notch filter, a main amplifier and an anti-aliasing filter which are connected in sequence.

4. The multi-channel atomic magnetometer device according to claim 2, characterized in that: The phase-locked loop includes a phase detector, a loop filter connected to the phase detector, and a voltage-controlled oscillator connected to the loop filter; the first phase-sensitive detection module and the second phase-sensitive detection module both include a multiplier and a low-pass filter connected to the multiplier.

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