173 results about "Atomic magnetometer" patented technology

The present disclosure relates to an active graded magnetic compensation system and method for an unshielded SERF magnetometer. The system comprises: a detection laser, a half-wave plate, a magnetic field compensation coil, a magnetic field modulation coil, a non-magnetic heating assembly, an alkali-metal atomic vapor cell, a polarizing beam splitter prism, a balanced photodetector, a graded feedback control module, a pump laser, a quarter-wave plate, a focusing lens and a photodetector. By means of the present disclosure, a graded compensation system is used to realize high-precision compensation for a magnetic field within a large dynamic range in a geomagnetic environment, thereby ensuring that an instrument carries out high-sensitivity magnetic field measurement under geomagnetic conditions.

The invention provides a self-excited cesium optical pump atomic magnetometer and a magnetic field measurement method. The magnetometer comprises a physical probe part and a circuit part. The physical probe part comprises a cesium spectrum lamp, an optical element, a cesium atom absorption gas chamber, a radio frequency coil and a photoelectric detector; the circuit part comprises a photoelectric conversion circuit, a phase-locked amplification circuit and a radio frequency excitation circuit modulated by square waves. A macroscopic magnetic moment is generated by pumping cesium atoms through left-handed circularly polarized light, a radio frequency magnetic field induces Larmor precession, light intensity changes are detected and fed back to a radio frequency coil to form self-oscillation, and the external magnetic field intensity is calculated according to the linear relation between oscillation frequency and the magnetic field. Square wave modulation is adopted to broaden the measurement bandwidth, a magnetic field direction adjusting system is additionally arranged to automatically keep an angle of 45 degrees between an optical axis and a magnetic field so as to eliminate a blind area, the hemisphere automatic switching function is achieved, and the advantages of being high in sensitivity, fast in response, high in adaptability, small in size and low in power consumption are achieved.

According to the three-axis real-time magnetic field measurement method and device based on the elliptically polarized light SERF atom magnetometer, three-axis magnetic field information is coded through the asymmetrical coupling characteristic of elliptically polarized light, z-axis magnetic field signal components with different frequencies are synchronously demodulated based on a calculation module of an FPGA, and therefore effective superposition of z-axis magnetic field information is achieved; the method comprises the following steps of: 1, performing sideband demodulation on a differential amplification signal which takes elliptically polarized light as pumping light, acts on an atomic gas chamber, is converted by a polarization differential detection module and is output by utilizing an FPGA (Field Programmable Gate Array)-based calculation module in an elliptically polarized light SERF atom magnetometer system; respectively extracting a sum frequency signal component P + and a difference frequency signal component P-containing different z-axis magnetic field information; step 2, carrying out combined processing on P + and P-to generate a comprehensive data signal containing richer three-axis magnetic field information; and step 3, decoupling the signal into a magnetic field intensity component in an orthogonal direction, and forming a three-axis real-time magnetic field measurement result as a magnetometer signal output.

The invention belongs to the field of quantum precision sensing and measurement, and provides an optical fiber collimator applied to an atom magnetometer and an assembly method of the optical fiber collimator. The optical fiber collimator applied to the atom magnetometer comprises a polarization-maintaining optical fiber pigtail, a lens, a laser homogenizing wave plate, a circular polarization polarizer, a diaphragm and a sleeve, the lens is arranged on the downstream of the polarization-maintaining optical fiber pigtail, the lens is an aspheric lens, the laser homogenizing wave plate is provided with a homogenizing area, the polarization axis of the circular polarization polarizer coincides with the polarization axis of emergent light of the lens, and the diaphragm is arranged in the sleeve. The light source is used for generating circularly polarized light, the diaphragm is used for limiting the shape of an emergent light spot, and the sleeve is used for installing the polarization-maintaining optical fiber pigtail, the lens, the laser homogenizing wave plate, the circular polarization polarizer and the diaphragm. The atomic polarization uniformity can be effectively improved, the response signal of the atom magnetometer is improved, the signal-to-noise ratio of the quantum sensor system is improved, and the quantum sensor system is suitable for being used in a high-precision measurement scene.

This invention provides a fast frequency closed-loop control method and system for an alkali metal atomic magnetometer laser, comprising: setting the laser current and laser temperature, calculating and obtaining the laser frequency closed-loop control signal SigX; and controlling the laser frequency based on the offset value of the frequency closed-loop control signal SigX and the correlation function f(I) = φ(I, SigX) between the current value and SigX. X The process involves calculating and obtaining the current adjustment value ΔI0, which is then directly applied to the laser current. The difference between the current adjustment value I1 and the set value I0 is calculated as ΔI1. Based on the correlation function f = φ(f(I), f(T)), the temperature change ΔT1 corresponding to the current change ΔI1 is calculated. This temperature adjustment ΔT1 is then applied to the laser temperature. By adjusting the laser temperature to T1, the laser current value is changed back from the adjustment value I1 to the initial set value I0. This invention addresses the problem in existing technologies where using laser current as a feedback signal for closed-loop control of laser frequency easily affects the laser's performance and consequently its lifespan.

The application provides an atomic magnetometer heading error dynamic compensation method and an atomic magnetometer. E ; step two, an alternating current magnetic field parallel to the driving light direction is actively applied to the atomic magnetometer; the response characteristics of the atomic magnetometer to the alternating current magnetic field are the same as the response characteristics of the atomic spin error magnetic field, that is, B=B0+B E ·cosθ+B AC ·cosθ; the frequency f of the magnetic field B f detected by the atomic magnetometer is used to realize atomic magnetometer heading error dynamic compensation, wherein B is the total magnetic field detected by the atomic magnetometer, B0 is the environmental magnetic field intensity in the geomagnetic environment, and θ is the included angle between the driving light and the environmental magnetic field. The technical scheme of the application is used to solve the technical problem that high sensitivity and low heading error are difficult to be considered together with the gradual reduction of the volume of the atomic magnetometer in the prior art.

The application discloses a method for improving low-frequency precision of an atomic magnetometer, and relates to the technical field of weak magnetic detection. In the method, the closed-loop atomic magnetometer is in a zero-locking state, a direct-current bias system is automatically and accurately adjusted, the atomic magnetometer is caused to work in a critical interval between a zero-locking region and a linear region, the zero-locking region has the suppression on low-frequency magnetic noise, and the linear region has a higher response to a measured magnetic field, so that the low-frequency measurement precision of the atomic magnetometer is improved. The application is suitable for an optical pumping atomic magnetometer system, and is favorable for improving the precision and stability of the atomic magnetometer, and can significantly improve the magnetic field sensitivity in the low-frequency part.

The invention discloses an atomic magnetometer longitudinal magnetic field interference resisting method and system based on zero offset point control, and the method comprises the steps: building a system response model containing a zero offset error, and respectively setting the zero offset points of first harmonic and second harmonic response signals as closed-loop control targets of x-axis and y-axis magnetic fields; and the output response of the double-loop closed-loop feedback control system is stabilized at a zero offset point, so that the interference of longitudinal magnetic field fluctuation on transverse magnetic field measurement is isolated in principle, and the real-time decoupling measurement of the transverse magnetic field to be measured is realized. The problem that quasi-static and dynamic longitudinal magnetic field interference cannot be suppressed at the same time in the prior art is solved, and the device has the advantages of being completely free of longitudinal magnetic field interference, biaxial decoupling measurement and long-term stable work.

A traceable multi-mode extremely weak magnetic field measuring device and method, comprising helium-3 atoms and an atomic magnetometer in a spin-exchange relaxation-free state, the helium-3 atoms polarized by metastable exchange optical pumping under an extremely weak magnetic field provide a traceable magnetic field value for the atomic magnetometer, the value is compared with the output response of the atomic magnetometer to obtain a calibrated scale factor of the atomic magnetometer, so that the measurement values of the atomic magnetometer are traceable. The atomic magnetometer meter head comprises four independent detection channels, the four detection channels are obtained by beam splitting of two detection lasers with different frequency detuning amounts, and the channels have high consistency. The method proposed by the application is compatible with the cooperative use of multiple probes, and can realize single-meter-head multi-channel measurement, meter-head internal magnetic field gradient measurement and meter-head inter-magnetic field gradient measurement three measurement modes, each mode has high consistency and high sensitivity.

The application provides an atomic spin low-noise high-bandwidth magnetic field measurement method and an atomic magnetometer, and comprises the following steps: driving light working current I Q0 The high-frequency current micro-perturbation is superimposed on the top; under the driving light current modulation, the atomic spin optical frequency shift generates a disturbance, and the frequency f1 optical frequency shift modulation is realized; the optical frequency is detected by scanning the detection light current, and the spin precession signal phase disturbance amplitude A is calculated in real time; when A is maximum, the atomic magnetometer sensitivity is optimal; the atomic magnetometer is kept in the state of optimal sensitivity through the closed-loop control of the detection light frequency; the spin precession signal extracted by the detection light is locked at 90° phase in a closed loop, and the atomic spin low-noise high-bandwidth magnetic field measurement is realized. The technical scheme of the application is used to solve the technical problems that there is a lack of small-size atomic magnetometer linearly polarized detection light frequency sensing means in the prior art, and the atomic magnetometer magnetic field noise and measurement bandwidth are easily degraded due to the detection light frequency drift in the actual application environment.

The invention relates to an active magnetic compensation system and a control method, the active magnetic compensation system comprises a magnetic shielding cabin, an SERF atom magnetometer, a composite controller, a voltage-controlled current source and a biplane compensation coil, the SERF atom magnetometer is placed in the magnetic shielding cabin and is used for measuring an internal magnetic field to obtain an internal magnetic field signal; the composite controller is used for compensating the output delay of the SERF atom magnetometer according to the internal magnetic field signal and generating a control signal for compensating the magnetic field; the voltage-controlled current source is used for generating compensation current according to the control signal; the biplane compensation coil is used for generating a compensation magnetic field according to the compensation current. Through the composite controller, the output delay of the SERF atom magnetometer is compensated, so that the stability and the response speed of an active magnetic compensation system are improved, and a stable extremely-weak magnetic field environment in a magnetic shielding cabin is realized.

The present application relates to the technical field of geophysical exploration, in particular to a downhole three-component magnetic field sensing system based on atomic magnetometer. The downhole three-component atomic magnetic field sensor is connected with the optical fiber signal modem in the ground well logging vehicle through the armored photoelectric composite cable. The optical fiber signal modem is used for real-time demodulation of the three-component magnetic field signals and three-component attitude signals measured by the three-component atomic magnetic field sensor. The three-component atomic magnetic field sensor comprises a non-magnetic high-temperature packaging structure, a high-temperature-resistant atomic gas chamber module, a three-axis orthogonal laser optical system, a high-temperature-resistant photoelectric detection array, a power management module, a temperature sensor, a magnetic field solving and signal processing unit and a three-component optical fiber attitude sensor which are arranged in the non-magnetic high-temperature packaging structure. The three-component atomic magnetic field sensor adopts the atomic magnetometer measurement principle, combines the high-temperature-resistant materials and the optimized heat dissipation design, and can work stably in an environment of up to 200 DEG C.

The application relates to an inter-axis coupling suppression method and device, wherein the inter-axis coupling suppression method comprises the following steps: after a preset high-frequency modulation field is applied to a first measurement axis and a second measurement axis of an atomic magnetometer, a first excitation strategy and a second excitation strategy of the atomic magnetometer are independently executed respectively, and execution results of the excitation strategies are analyzed to obtain a first frequency response and a second frequency response; a coupling matrix is determined based on the first frequency response and the second frequency response; a decoupling filter matrix corresponding to the coupling matrix is determined and is converted into time-domain filter coefficients; when the atomic magnetometer performs actual double-axis measurement, a first actual measurement signal corresponding to the first measurement axis and a second actual measurement signal corresponding to the second measurement axis are acquired in real time, and the first actual measurement signal and the second actual measurement signal are decoupled based on the time-domain filter coefficients to obtain a first decoupled signal and a second decoupled signal. Through the application, the problem that the measurement accuracy of the magnetometer is low is solved.

This invention discloses a method and system for monitoring the EIT signal lock-in state of a CPT atomic magnetometer. The method modulates the frequency of the microwave signal injected into the laser and demodulates the optical power signal output by the detector to obtain its second harmonic signal. The amplitude of the EIT signal peak is then calculated. By determining whether the amplitude is less than a set threshold, it is determined whether the CPT atomic magnetometer has lost lock. If it has lost lock, the system re-searches for and locks the EIT signal peak, restoring the magnetic field measurement function. This invention addresses the problem of existing CPT magnetometers being unable to determine the EIT signal peak lock-in state; the device can automatically find the EIT signal peak and restore the lock-in state, improving the equipment's engineering applicability.

The application discloses a dead-zone-free atomic magnetometer device and method based on pumping-detection information fusion and relates to the technical field of atomic magnetometers. Through optical-magnetic double-resonance pulse modulation, atoms can generate free precession signals in each magnetic field direction. In the spin polarization free precession stage, the output signals of pumping light and detection light are collected and detected, the dead zones of the output signals of the two light beams are complementary, one signal with a high signal-to-noise ratio is selected as an output through signal processing, and then a dead-zone-free high-sensitivity optical pumping atomic magnetometer is realized. The application realizes the full-range dead-zone-free atomic magnetometer without reducing the sensitivity of the magnetometer, and is helpful to the further application of the optical pumping atomic magnetometer in the field of space magnetic field measurement in the future.

The present invention discloses a vector magnetic field measurement method based on an extended Kalman filter, comprising the following steps: Step 1, establishing a model, establishing a nonlinear system evolution model and a detection model in an atomic magnetometer; Step 2, establishing an extended Kalman filter to estimate the magnetic field vector. The accuracy of traditional vector detection schemes depends largely on the mathematical model for extracting the magnetic field direction from experimental signals, and also requires a bias field with very high magnitude and direction accuracy, which is time-consuming and labor-intensive. The present invention overcomes the defect that the original atomic magnetometer vector magnetic field estimation requires the additional setting of a bias magnetic field, thereby obtaining the vector information of the magnetic field more accurately.

The application discloses a magnetic moment comparator device and a measuring method. The magnetic moment of a current-carrying standard coil is proportional to the magnetic field generated at a fixed distance on the axis, and according to the principle of equivalence between the magnetic dipole layer and the current-carrying coil in electromagnetism, the magnetic moment of the magnetic sample at the same position can be measured by the current-carrying standard coil when the spatial magnetic field can be accurately measured. The application designs a magnetic moment comparator in a magnetic shielding cylinder, uses an atomic magnetometer to measure the absolute magnetic field with high sensitivity, places a current-carrying standard coil at a distance r0 on one side of the atomic chamber along the background magnetic field direction, and the axis is parallel to the background magnetic field direction; the magnetic moment direction of the magnetic sample is parallel to the background magnetic field direction, when the magnetic sample is moved to the position of the atomic chamber at a distance r0 on the other side of the atomic chamber by a sample transmission rod, the current flowing into the standard coil is changed in real time under the condition that the background magnetic field remains unchanged, and then the magnetic moment of the magnetic sample is equal in size and opposite in direction to the magnetic moment of the current-carrying standard coil.

The invention provides a miniaturized single-beam multi-reflection atom magnetometer probe. The miniaturized single-beam multi-reflection atom magnetometer probe comprises a prism assembly, an alkali metal atom gas chamber and a second curved surface reflector. The prism assembly converts incident light into circularly polarized light and comprises a first optical surface for receiving the incident light and a second optical surface for emitting the circularly polarized light. The alkali metal atom gas chamber is arranged opposite to the second optical surface, the second curved surface reflector is arranged on one side, back to the second optical surface, of the alkali metal atom gas chamber, and the second curved surface reflector reflects circularly polarized light penetrating through the alkali metal atom gas chamber back to the alkali metal atom gas chamber. The second optical surface reflects the circularly polarized light emitted to the second optical surface from the alkali metal atom gas cell to the alkali metal atom gas cell. According to the invention, circularly polarized light can repeatedly pass through the alkali metal atom gas chamber, atoms are polarized for multiple times, the number of atoms is equivalently increased in a limited area, the ultimate sensitivity of the atom magnetometer probe is improved, and miniaturization and integration of the atom magnetometer probe are realized.

The application discloses a kind of triaxial SERF atom magnetometer quadrature double frequency modulation system and method, the system utilizes signal generation module to generate frequency f m The sine quadrature modulation signal of cosine is respectively driven SERF atom magnetometer X and Y axis magnetic field generating coil, and 2nf m Frequency sine signal of driving Z axis coil, through the integral filter of 3 groups of integral period integration, the open-loop magnetic field signal of X axis, Y axis and Z axis magnetic field component is obtained, and through control module, the driving current of three-axis magnetic field coil is controlled to generate compensation magnetic field, so that the open-loop magnetic field signal of X axis, Y axis and Z axis magnetic field component is zero, at this time, the magnetic field intensity of atom chamber is zero, and the compensation current output by control module is the X, Y and Z axis magnetic field intensity signal measured by triaxial SERF atom magnetometer.The system can directly extract triaxial magnetic field calculation signal from a laser signal, and eliminate the cross-coupling effect when triaxial magnetic field is calculated, improve the measurement range and quadrature of SERF atom magnetometer, with very high engineering application value.

The present application relates to the technical field of atomic magnetometer, and particularly relates to a laser frequency stability control method of NMOR atomic magnetometer based on optical rotation signal, which comprises the following steps: irradiating an atomic cell with linearly polarized laser to pump atoms and detecting optical rotation signal; once demodulating the optical rotation signal to obtain magnetic resonance signal; applying a fixed frequency modulation signal to the laser frequency; twice demodulating the magnetic resonance signal to obtain a demodulation signal corresponding to the laser frequency offset; and feeding back and adjusting the laser frequency according to the demodulation signal. The present application is used to reduce the influence of laser frequency drift on the magnetic resonance signal of NMOR atomic magnetometer, improve the stability of long-term work of NMOR atomic magnetometer, and reduce the system volume and system complexity.

The application relates to the technical field of deep space exploration precise magnetic field measurement and sensors, and provides a closed-loop temperature compensation circuit and a temperature compensation method for an atomic magnetometer laser. The closed-loop temperature compensation circuit and the temperature compensation algorithm are provided, the shell temperature value of the laser unit is converted into a digital signal by an ADC unit and then transmitted to an FPGA controller unit, then the temperature compensation algorithm process is realized by the FPGA controller unit, the temperature compensation code value corresponding to the current shell temperature value is determined, the temperature compensation code value is added to the reference temperature point code value compensated by temperature to obtain a temperature correction code value, the temperature correction code value is transmitted to the laser unit through a second DAC unit and a TEC controller unit connected in series, and therefore the control parameters of the TEC controller can be dynamically adjusted under different temperature environments, the working parameters of the laser TEC are adjusted, and the output frequency stability of the laser is ensured.

The application provides an atomic magnetometer light power adjustment system and method based on line width scanning, and belongs to the field of precision measurement. The atomic magnetometer light power adjustment system comprises: a magnetic field generating coil configured to generate a scanning magnetic field linearly changing over time based on a preset waveform driving current; an atomic gas chamber configured to modulate detection light of an atomic magnetometer based on the scanning magnetic field to obtain a light modulation signal; a photodetector configured to convert the light modulation signal into an initial electric signal; a signal processing module configured to obtain an atomic spectral line width value based on the initial electric signal; and an adjustment module configured to adjust a light attenuator of the atomic magnetometer based on a preset light power-atomic spectral line width calibration relationship, a target light power value and the atomic spectral line width value, so as to update the light power value of the atomic magnetometer.

This invention discloses a cross-axis synchronous in-situ magnetic compensation method for a dual-beam SERF atomic magnetometer, belonging to the field of magnetic compensation technology. Based on the steady-state solution of the Bloch equation, a mathematical correlation is established between the light intensity signal and the triaxial magnetic field. First, the optimization target is determined according to the remanent magnetization direction of the sensitive axis. A three-part nested method is used to iteratively compensate the pump axis remanent magnetization, compensating the pump axis magnetic field to within the error range. Then, in the two-dimensional search space formed by the detection axis and the sensitive axis, the optimal compensation values ​​for the detection axis and the sensitive axis are simultaneously optimized through independent iteration and information interaction using a dual particle swarm optimization algorithm. Finally, the triaxial compensation current value is output to drive the compensation coil to generate a compensation magnetic field, completing rapid and high-precision automatic compensation of the triaxial remanent magnetization. This invention features a simple compensation process, fast convergence speed, and high compensation accuracy, adapting to the application requirements of miniaturized and integrated dual-beam SERF atomic magnetometers, and has significant application value in weak magnetic field detection fields such as biomagnetic imaging.

The invention relates to the technical field of data processing, and further relates to a data extraction method and system for digital geological mineral exploration. Comprising the following steps: step 1, performing analog-to-digital conversion on multiple paths of original magnetic field response voltage signals synchronously acquired by multiple optical pump atomic magnetometer sensing units to obtain multiple paths of original magnetic field response digital sequences; 2, performing phase gradient field iteration reconstruction processing on the magnetic field in-phase response matrix and the magnetic field orthogonal response matrix to obtain a reconstructed phase matrix and a magnetic field amplitude matrix; and 3, calculating a magnetic field amplitude deviation matrix and a phase deviation matrix according to the magnetic field amplitude matrix and the reconstructed phase matrix, converting the mineral anomaly candidate position into a geological space coordinate, and outputting geological mineral anomaly feature data.

The application provides a very low frequency atomic magnetometer environment interference suppression method based on polarization selection reception, wherein a precession main magnetic field B e and -B e are respectively applied by a main magnetic field coil in z direction and -z direction in front and back two regions of a gas chamber e and -B e regions are detected by using detection laser in x direction; external very low frequency signals are detected by interaction with atoms polarized in z direction to make the atoms produce precession signals in xOy plane, so that the signals are detected by light detection; when the external signals are linear polarization, according to the selection rule of angular momentum conservation, the precession signals of atoms in B e and -B e regions are offset, so that the system does not respond to linear polarization signals; for circular polarization signals, only atoms in B e or -B e region have precession signals, so that the detection of circular polarization signals is realized. The technical scheme of the application is applied to solve the technical problem of environmental magnetic noise interference of a very low frequency atomic magnetometer in an actual application scene in the prior art.

The invention provides a single light source atom magnetometer with a low measurement dead zone and a magnetic field measurement method. The single light source atom magnetometer comprises a laser, an optical fiber splitter, a first collimator, a second collimator, an alkali metal atom gas chamber, an excitation magnetic field coil, a signal processor, a first photoelectric detector and a second photoelectric detector, according to the single-light-source atom magnetometer, the same light source is divided into two beams to detect the atom gas chamber at different angles, detection signals are obtained, the detection range of the atom magnetometer reaches 360 degrees, and the detection dead zone of the atom magnetometer is greatly reduced. By applying the technical scheme of the invention, the technical problem that the sensitivity is reduced or the measurement is failed when a magnetic field in a certain direction is measured due to the inherent measurement dead zone in the operation process of the traditional magnetometer is solved.

This invention relates to a miniaturized triaxial SERF atomic magnetometer device with dual-pump light semi-transparent and semi-reflective beams. A single pump light is guided into the probe by a polarization-maintaining fiber. Then, using a half-wave plate, a polarization beam splitter, a right-angle mirror, and a quarter-wave plate, the pump light is split into two circularly polarized pump lights of equal intensity, which then pass perpendicularly through the same alkali metal gas cell. The pump light passing through the gas cell is then split by a semi-transparent and semi-reflective planar beam splitter; half of the pump light is detected by a photodetector to extract magnetic field information, while the other half returns along the same path and passes through the alkali metal gas cell a second time. This invention achieves high-sensitivity simultaneous measurement of triaxial magnetic fields in a miniaturized triaxial SERF atomic magnetometer, enhances atomic spin polarizability, and improves the uniformity of atomic spin polarizability within the gas cell. It addresses the technical challenge of achieving uniform spin polarizability in miniaturized SERF atomic magnetometer applications, and is beneficial for applications of array-type triaxial SERF atomic magnetometers in fields such as magnetocardiography and magnetoencephalography.

The utility model discloses a miniaturized single-beam reflection-type atom magnetometer probe and an atom magnetometer. The atom magnetometer probe comprises a housing; an alkali metal atom gas cell; the combined prism is arranged on one side of the alkali metal atom gas chamber; the reflecting mirror is arranged on the other side of the alkali metal atom gas chamber; the photoelectric detector is arranged on one side, deviating from the alkali metal atom gas chamber, of the combined prism; the combined prism is used for converting collimated light received by the incident plane into circularly polarized light, the circularly polarized light is emitted to the alkali metal atom gas chamber through the emergent plane, and the reflector is used for reflecting pumping light passing through the alkali metal atom gas chamber back to the alkali metal atom gas chamber. The absorption optical path of the pumping light is remarkably improved, secondary polarization is achieved, meanwhile, the action intensity of the pumping light and alkali metal atoms is improved, the number of atoms is equivalently increased in a limited area, higher sensitivity can be achieved at a lower temperature, the performance of the single-beam atom magnetometer is remarkably improved, and miniaturization design is facilitated.

The application discloses a light-magnetic modulation method and device for enhancing a single-beam free precession atomic magnetometer signal, and is based on synchronous light pumping technology and radio frequency magnetic field pulse control technology. Through light-magnetic modulation control, atomic spin polarization and free precession signal excitation are realized, so that more spin polarization components participate in free precession, and full-range signal enhancement of the single-beam free precession atomic magnetometer is realized. The application enhances the free precession signal and improves the signal-to-noise ratio, which is helpful to further improve the sensitivity of the single-beam free precession atomic magnetometer and is convenient for further application of the single-beam free precession atomic magnetometer in the field of quantum precise magnetic field measurement in the future.

The application relates to the technical field of magnetic field measurement, in particular to a double-frequency resonance locking system of an NMOR atomic magnetometer based on FPGA, which comprises an FPGA, a laser modulation driving unit and a signal acquisition and processing unit, a homologous synchronous reference signal source, a first demodulation branch and a second demodulation branch are arranged in the FPGA, signals corresponding to a single Larmor frequency and double Larmor frequency are synchronously demodulated respectively to obtain corresponding in-phase signals and quadrature signals. The FPGA determines corresponding weight coefficients according to the output signals of the two demodulation branches, fuses corresponding frequency correction amounts and obtains a frequency control amount to adjust the laser modulation frequency. The system is also provided with a frequency sweeping and peak searching logic and a host computer parameter configuration module. The application is used for realizing that there is always a feedback signal with sufficient signal-to-noise ratio in the whole space range, so that the measurement blind area of the single-frequency NMOR magnetometer is eliminated.