254 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 discloses microelectronic magnetic force detection equipment and a method thereof, and belongs to the technical field of microelectronic magnetic force. The microelectronic magnetic force detection equipment comprises an equipment main body, a locking mechanism, a clamping mechanism and a detection mechanism; the lower portion of the equipment body is connected with the locking mechanism, the upper portion of the equipment body is connected with the clamping mechanism, and the detection mechanism is arranged on the right side of the equipment body. By means of the mode, the function of continuous feeding and discharging is achieved through the clamping mechanism and the locking mechanism, detection continuity is achieved, automatic operation is achieved in the whole process, and the operation stability is achieved while the working efficiency is improved; the detection capability is further expanded by adopting an array form of the atomic magnetometers, multi-angle synchronous detection can be realized after a plurality of atomic magnetometers are combined into an array, and meanwhile, the surface of the chip is cooled by blowing air through the cooling pipes at different angles, so that non-uniform temperature of the magnetic core in the detection process is prevented, and the detection precision is improved. And the stability of magnetic force detection is improved.

An atomic magnetometer, an atomic magnetometer measurement system, and a magnetic field measurement method. The atomic magnetometer comprises a laser (1), a probe (2), a magnetic field generation unit (3), and a magnetic field compensation unit (4); the probe (2) is connected to the laser (1) by means of a polarization-maintaining collimation optical fiber (5), and light emitted by the laser (1) is used as pump light; the probe (2) is used for performing beam splitting on the pump light and in a gas chamber, forming two beams of light that are perpendicular to each other and do not intersect with each other, so as to respectively detect the two beams of light to obtain a first detection signal and a second detection signal; the magnetic field generation unit (3) is used for generating a magnetic field signal at the gas chamber on the basis of modulation signals in three directions; the magnetic field compensation unit (4) is used for compensating, on the basis of the modulation signals in the three directions, the first detection signal and the second detection signal, magnetic fields to be measured in the three directions to zero, and performing measurement to obtain said magnetic fields. The atomic magnetometer, the atomic magnetometer measurement system, and the magnetic field measurement method can enlarge a bandwidth range for measurement.

The invention discloses an ultrahigh-sensitivity three-axis closed-loop spin exchange relaxation-free atom magnetometer, which expands the ultrahigh-sensitivity measurement capability of the atom magnetometer to three axes based on parameter modulation optimization and double detection light, fully inhibits transverse spin relaxation introduced by a modulation magnetic field, provides more high-quality information for weak magnetic measurement, and improves the measurement accuracy. Based on decoupled magnetic field information, a three-axis magnetic field sensitive to an atomic ensemble is locked to zero in real time, and closed-loop feedback quantity is used as magnetic field measurement information, so that the problems of nonlinear offset of a magnetometer calibration coefficient and cross-axis coupling crosstalk caused by magnetic field drift are fundamentally inhibited; the high anti-interference capability of the atom magnetometer in a complex magnetic field environment is enhanced, long-time stable measurement and magnetic field measurement precision of the atom magnetometer are guaranteed, sub-fT-level sensitivity and pT-level precision can be achieved on transverse double axes, and the atom magnetometer is suitable for the fields of extremely weak magnetic measurement testing, biomedical weak magnetic imaging and the like.

The invention discloses a magnetic field compensation method of an atomic magnetometer, electronic equipment, a program product and a storage medium. The magnetic field compensation method of the atomic magnetometer comprises the steps that an output signal in the first axis direction and an output signal in the second axis direction output by the atomic magnetometer are obtained, the output signals comprise information of a magnetic field to be measured, and the atomic magnetometer comprises compensation coils used for generating a compensation magnetic field in the first axis direction and a compensation magnetic field in the second axis direction respectively; and a modulation coil for generating a first axial direction modulation magnetic field and a second axial direction modulation magnetic field, respectively. And according to the output signal in the first axis direction and the output signal in the second axis direction, alternately adjusting the input current of the compensation coils in the first axis direction and the second axis direction so as to zero the magnetic fields in the first axis direction and the second axis direction.

According to the enhanced diffusion pumping virtual magnetic field SERF atom magnetometer, only one laser and a light splitting element are combined, atoms in a gas chamber can be polarized through the diffusion effect, detection light is used for detection, pumping light does not directly act on the atoms detected by the detection light, and the detection efficiency is improved. The magnetometer is characterized in that the magnetometer comprises first pumping light and second pumping light which enter an air chamber in the z-axis direction, the first pumping light and the second pumping light are distributed in the y-axis direction in a spaced mode, and the first pumping light and the second pumping light are distributed in the y-axis direction in a spaced mode. Detection light entering the gas chamber in the x-axis direction is arranged in the interval, and the first pumping light, the second pumping light and the detection light all come from the same laser.

The invention discloses an atom magnetometer device and method based on detection light frequency detuning amount modulation. Red and blue detuning linear polarization modulation light is used as detection light to realize modulation of an optical rotation angle of an atom magnetometer. Under the condition that the optical power of the modulated light is kept unchanged, the frequency of the modulated light is subjected to red detuning and blue detuning conversion with the same detuning amount relative to the resonance frequency of the alkali metal atom D1 line, so that the rotation angle is quickly switched between positive deflection and negative deflection, the modulation of the rotation angle is realized, and the modulation efficiency is improved. And the modulated optical rotation angle signal is subjected to polarization differential detection and phase-locked amplification technologies to obtain a magnetometer output signal containing to-be-detected magnetic field information. Compared with a conventional atom magnetometer modulation method, the method has the advantages that the modulation of the optical rotation angle is indirectly realized by carrying out red and blue detuning modulation on the detection light, the introduction of a modulation magnetic field is avoided, the optical power noise is suppressed, the low-frequency noise is isolated, and compared with an unmodulated mode, the amplitude of the optical rotation angle is enhanced, and the sensitivity of the magnetometer is improved.

The invention discloses a multi-probe omnidirectional atomic magnetometer and a magnetic induction intensity measurement method. The multi-probe omnidirectional atomic magnetometer comprises three atomic magnetometer probes, a fluxgate sensor probe, an atomic magnetometer excitation acquisition module, a fluxgate sensor excitation acquisition module and a data processing module, the atomic magnetometer excitation acquisition module excites three atomic magnetometer probes and acquires the magnetic induction intensity of the position; the fluxgate sensor excitation acquisition module excites a fluxgate sensor probe and acquires three components of magnetic induction intensity of the position; the data processing module calculates included angles between the external magnetic field and the three atomic magnetometer probes, and magnetic field signals measured by the atomic magnetometer closest to 45 degrees are selected and output; when the probes are switched, the output value of the magnetic induction intensity of the previous probe is taken as the reference for continuous output, so that the omnidirectional continuous measurement of the magnetic induction intensity is realized; the problem that in the prior art, no-blind-area measurement of the atom magnetometer cannot be achieved can be solved.

The invention discloses a vector magnetic field measurement method based on extended Kalman filtering, and the method comprises the following steps: 1, building a model: building a nonlinear system evolution model and a detection model in an atomic magnetometer; and step 2, establishing an extended Kalman filter to estimate the magnetic field vector. The accuracy of a traditional vector detection scheme depends on a mathematical model for extracting a magnetic field direction from an experimental signal to a great extent, meanwhile, a bias field with very high size and direction accuracy is also needed, and time and labor are consumed. According to the method, the defect that the original atom magnetometer vector magnetic field estimation needs to additionally set a bias magnetic field is overcome, so that the vector information of the magnetic field is more accurately obtained.

The invention provides a self-calibration three-axis atom magnetometer capable of achieving vector and scalar integrated measurement. The magnetometer comprises a sensor probe and an electronics box. A laser generating unit in the electronics box generates a single beam of pumping laser to act on an alkali metal atom gas chamber in the sensor probe. According to the alkali metal atom zero field resonance principle, the pumping laser and alkali metal atoms interact to generate a light absorption signal containing environment magnetic field information. A photoelectric detection unit in the electronics box converts an optical signal into an electric signal, a three-axis modulation compensation circuit is used for demodulating the photoelectric signal and generating a compensation signal, and three-axis precision measurement of the magnetic field is achieved. The magnetometer can work in an Mz mode or a CPT mode, scalar measurement of a magnetic field is achieved, and therefore self-calibration of the three-axis vector of the magnetometer is achieved. By switching the measuring ranges, high-sensitivity and long-term accurate three-axis omnidirectional magnetic field measurement can be realized under different measuring ranges.

The invention discloses a three-axis SERF atom magnetometer orthogonal frequency doubling modulation and demodulation system and method, and the system employs a signal generation module to generate sine and cosine orthogonal modulation signals with the frequency of fm to drive an X-axis magnetic field generation coil and a Y-axis magnetic field generation coil of an SERF atom magnetometer respectively, and generates sine signals with the frequency of 2nfm to drive a Z-axis coil. Open-loop magnetic field signals of X-axis magnetic field components, Y-axis magnetic field components and Z-axis magnetic field components are obtained through three groups of integral filters for full-period integration, driving current of a three-axis magnetic field coil is controlled through a control module to generate a compensation magnetic field, the open-loop magnetic field signals of the X-axis magnetic field components, the Y-axis magnetic field components and the Z-axis magnetic field components are made to be zero, and at the moment, the magnetic field intensity of the atomic gas chamber is zero. The compensation current output by the control module is the X-axis magnetic field intensity signal, the Y-axis magnetic field intensity signal and the Z-axis magnetic field intensity signal measured by the three-axis SERF atom magnetometer. The system can directly extract a three-axis magnetic field resolving signal from a beam of laser signals, eliminates the cross coupling effect during three-axis magnetic field resolving, improves the measurement range and orthogonality of the SERF atomic magnetometer, and has extremely high engineering application value.

The invention discloses a double-chamber MEMS (Micro Electro Mechanical System) atomic gas chamber integrating heating and temperature measuring functions and a manufacturing method. The double-chamber MEMS atomic gas chamber adopts a glass-silicon-glass bonding three-layer structure, a heating coil and a temperature measuring coil are prepared on the back surface of a top glass cover plate, and a coil electrode is led out from the front surface of the top glass cover plate through a glass through hole technology; an optical cavity and a reaction cavity are arranged on the middle silicon wafer in parallel and are communicated through a micro-channel; the heating coil is made of a transparent conductive material, is located over the optical cavity and can directly heat alkali metal atoms in the cavity, the temperature measuring coil is arranged around the heating coil, and real-time closed-loop control over the temperature of the air chamber can be achieved through a circuit. Compared with an existing integration mode, heat dissipation is reduced, the heating efficiency of the air chamber is improved, and then the sensitivity and stability of quantum precision measurement instruments such as an atomic magnetometer and an atomic clock are improved.

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 provides an atomic magnetometer, an atomic magnetometer measurement system and a magnetic field measurement method, the atomic magnetometer comprises a laser, a probe, a magnetic field generation unit and a magnetic field compensation unit, the probe is connected with the laser through a polarization-maintaining collimation optical fiber, and light emitted by the laser is introduced as pump light; the probe is used for splitting the pump light and forming two beams of light which are vertical and not intersected in the air chamber so as to respectively detect the two beams of light to obtain a first detection signal and a second detection signal; the magnetic field generation unit is used for generating a magnetic field signal at the air chamber based on modulation signals in three directions, and the magnetic field compensation unit is used for compensating a magnetic field to be measured in three directions to zero based on the modulation signals in three directions, the first detection signal and the second detection signal, and measuring to obtain the magnetic field to be measured. According to the atomic magnetometer, the atomic magnetometer measurement system and the magnetic field measurement method provided by the invention, the bandwidth range of measurement can be improved.

A multi-channel atom magnetometer control system comprises a communication control sub-module, a communication control main module, a sensor control sub-module and an atom magnetometer module. The communication control main module comprises a switch circuit unit, a clock crystal oscillator unit and a stabilized power supply circuit unit, and is connected with the Ethernet communication units in the plurality of communication control sub-modules through golden finger parts, and the Ethernet communication units are connected with and control the sensor control sub-modules and the atomic magnetometer modules through the main control chip; through the Ethernet communication unit, more reliable and faster transmission of data and instructions between the atom magnetometer and an upper computer is realized, different network ports can be automatically switched and configured flexibly according to the requirements of different network devices, integration of a multichannel atom magnetometer communication control system is realized, and the communication control system is convenient to use. The atom magnetometers of multiple channels can synchronously control communication.

The invention provides an optical pump atomic magnetometer device for deep space weak magnetic and zero magnetic detection, which comprises a magnetometer probe and an electronics box, and adopts an internal modulation or external modulation method to realize laser constant power control. The internal modulation scheme is as follows: the circuit realizes laser constant power control by synchronously controlling the driving temperature and current of the laser. The external modulation scheme is that optical power control devices such as an acousto-optic modulator or an electrically controlled attenuator are added to the output end of the laser to carry out closed-loop control on the laser power. According to the optical pump magnetometer with the stable optical power, a low-frequency modulation and narrow linewidth Mz magnetic resonance method is adopted, long-term accurate measurement can be conducted on weak magnetic field scalar quantity which is lower than geomagnetic field intensity and equivalent to Mz resonance linewidth, and near-zero magnetic field intensity detection can be achieved by adding a small compensation magnetic field on a magnetometer probe and a modulation resolving scheme of the small compensation magnetic field. The device is suitable for detection of deep space weak magnetic field environments such as earth high orbit, moon, Mars, asteroid, various satellites, interplanetary space and the like, and can also be applied to medical and basic scientific research.

The embodiment of the invention discloses a temperature control circuit of an atomic magnetometer. The temperature control circuit of the atomic magnetometer comprises a main control circuit, a temperature acquisition circuit and a heating module, wherein the temperature measuring circuit is connected with the temperature sensor and is used for measuring the temperature of an atomic gas chamber of the atomic magnetometer, acquiring temperature data of the atomic gas chamber and sending the temperature data to the main control circuit; the master control circuit comprises a PID control module, a DAC module and a DMA module. The PID control module is used for determining a sine wave array peak-to-peak value according to the temperature data; the DMA module is used for transmitting the sine wave array peak-to-peak value to the DAC module; the DAC module is used for outputting sine wave signals according to the sine wave array peak-to-peak value so as to drive the heating module; and the heating module is connected with the atomic gas chamber and is used for heating the atomic gas chamber according to the sine wave signal.

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 present invention discloses a real-time closed-loop control device and method for laser polarization in an optically pumped atomic gas chamber, and belongs to the technical field of high-precision atomic spin magnetic field and inertial measurement. The present invention is based on atomic spin optical pumping technology and first-order differential control technology, and uses a liquid crystal phase retarder to realize polarization state modulation of the pumping light. The optical power change of the pumping laser passing through the polarized atomic gas chamber is detected by a photodetector, and a first-order differential signal is extracted as an error signal by a phase-locked amplifier. The polarization state of the pumping light is stably controlled at a circular polarization point, and laser polarization modulation detection and closed-loop control are realized. The present invention effectively improves the optical pumping efficiency and the long-term stability of the electronic polarization rate, and can be widely used in quantum precision measuring instruments including optically pumped atomic gas chambers, such as atomic gyroscopes, atomic magnetometers, atomic gravimeters, etc., and is particularly suitable for small quantum sensors that pursue high integration.

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 invention relates to a high spatial resolution array SERF atom magnetometer based on light beam homogenization, which provides a new idea for the realization of a miniaturized multi-channel atom magnetometer and lays a foundation for the development of high spatial resolution magnetic field detection, a portable multi-channel atom magnetometer and a biological magnetic imaging technology. Comprising an alkali metal gas chamber located in a magnetic compensation coil, a 3 * 3 photodiode array is arranged on the laser emergent side of the alkali metal gas chamber, the laser incident side of the alkali metal gas chamber is connected with a flat-topped beam shaper through a 1 / 4 wave plate, and the flat-topped beam shaper shapes light spots with incident light intensity in Gaussian distribution into flat-topped light spots with light intensity evenly distributed. The flat-top light spots sequentially pass through the 1 / 4 wave plate and the alkali metal gas chamber along the z axis and then cover the photodiode array located on the xy plane, and nine photodiodes in the photodiode array form nine signal channels for receiving the flat-top light spots from nine positions.

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.

According to the single-beam miniaturized triaxial SERF atom magnetometer, through a compact and reasonable internal light path design, incident light introduced by a single light source is divided into two beams of pump light which are perpendicular to each other and are spatially separated through a designed combined polarization splitting prism, and then the two beams of pump light act on different atom ensembles through the same alkali metal gas chamber, so that the single-beam miniaturized triaxial SERF atom magnetometer is obtained. The device can effectively improve the crosstalk problem of simultaneous measurement of three-axis magnetic fields, has the characteristics of low cost, high space utilization rate, high reliability, high stability, easiness in miniaturization and the like, and is characterized by comprising Y-axis circular polarization pump light penetrating through an alkali metal gas chamber in the positive direction of the Y axis and Z-axis circular polarization pump light penetrating through the alkali metal gas chamber in the negative direction of the Z axis, and the Y-axis circular polarization pump light and the Z-axis circular polarization pump light are in a spatial separation state in the alkali metal gas chamber.

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.