A single-radio frequency magnetic field-based three-axis magnetic field measurement method and system

Abstract

The application discloses a kind of based on single radio frequency magnetic field three-axis magnetic field measurement method and system, the three-axis magnetic field measurement method includes applying single radio frequency magnetic field and control pre-acquired linearly polarized light is carried out optical pumping to atomic gas chamber, to obtain the double-axis parameter resonance optical signal of the magnetic field to be measured according to polarized atomic gas chamber, to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured;Compensating magnetic field is applied to polarized atomic gas chamber, and compensated atomic gas chamber is obtained;Bias magnetic field is applied to compensated atomic gas chamber, and bias atomic gas chamber is obtained, to obtain the third axis parameter resonance optical signal of the magnetic field to be measured;Third axis parameter resonance optical signal is demodulated, and the third axis magnetic field component information of the magnetic field to be measured is obtained, and then the first axis magnetic field component information and the second axis magnetic field component information are combined to obtain the three-axis magnetic field component information of the magnetic field to be measured, to realize high sensitivity three-axis vector measurement based on single radio frequency magnetic field in the system of simplified structure.

Description

Technical Field

[0001] This invention relates to the field of magnetic field measurement technology, specifically to a triaxial magnetic field measurement method and system based on a single radio frequency magnetic field. Background Technology

[0002] Vector magnetic field measurement can acquire information about the direction and components of a magnetic field in space. Compared with scalar measurement methods that only measure amplitude, it can provide a more complete characterization of the magnetic field and has important application value in fields such as magnetic navigation, magnetic anomaly detection, geophysical exploration, and biomagnetism measurement. Existing vector magnetometers are mainly divided into three categories: the first category is sensors based on the principle of magnetic field component projection, such as superconducting quantum interference devices, fluxgate sensors, and Hall sensors; the second category is magnetometers based on solid-state atomic systems, represented by diamond NV color centers, which naturally possess vector measurement capabilities; the third category is optically pumped atomic magnetometers based on gaseous atomic ensembles, which have been widely studied and applied due to their advantages such as ultra-high sensitivity, low cost, and compact structure.

[0003] However, optically pumped atomic magnetometers typically only respond to magnetic field amplitude under geomagnetic field conditions, constituting a scalar measurement method. To extend to vector measurements, existing schemes usually employ methods such as applying a static bias magnetic field, a multi-frequency modulated magnetic field, or a rotating transverse magnetic field, or using multiple beams of light to detect the projected components of atomic spin in different directions. These schemes often rely on multiple modulated magnetic fields or complex optical path configurations, resulting in complex system structures and high debugging difficulty. Atomic magnetometers operating under zero magnetic field conditions can achieve natural vector sensitivity, and common implementation methods include measurement schemes based on the Hanler effect or parametric resonance. However, the Hanler effect scheme is susceptible to the coupling of different magnetic field component signals when using single-beam circularly polarized light detection; while the parametric resonance scheme is usually only sensitive to a single component in the radio frequency magnetic field direction, making it difficult to directly apply to three-axis vector measurements.

[0004] To address the need for near-isotropic triaxial measurements, existing methods mainly fall into two categories: one uses a single beam of light combined with two radio frequency magnetic fields, which, while representing the simplest field configuration, typically sacrifices lateral sensitivity; the other uses multiple beams of light and multiple radio frequency magnetic fields, achieving more balanced triaxial sensitivity, but the complex magnetic field configuration and hardware structure limit miniaturization. In summary, the introduction of multiple radio frequency fields in existing technologies inevitably suppresses the intrinsic sensitivity of atomic magnetometers and increases the possibility of interaxial crosstalk. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention discloses a triaxial magnetic field measurement method and system based on a single radio frequency magnetic field. The aim is to achieve high-sensitivity triaxial vector measurement by introducing a single radio frequency magnetic field and at least one beam of light, while avoiding the suppression of intrinsic sensitivity and complex field configuration caused by multiple radio frequency fields. Simultaneously, by combining the physical characteristics of atomic systems in terms of relaxation properties and dynamic response, the magnetic field measurement meets the requirements of triaxial measurement while also taking into account key performance indicators in engineering applications such as operating bandwidth and inter-axis projection error.

[0006] To achieve the above objectives, this invention discloses a triaxial magnetic field measurement method based on a single radio frequency magnetic field, applicable to atomic gas cells filled with working atoms; the triaxial magnetic field measurement method includes: A single-frequency magnetic field is applied to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized; The pre-acquired linearly polarized light is controlled according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell; The biaxial parametric resonance optical signal of the magnetic field to be measured is obtained by the polarized atomic gas cell, and the biaxial parametric resonance optical signal is demodulated to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. A compensation magnetic field is applied to the polarized atomic gas cell based on the first axis magnetic field component information and the second axis magnetic field component information to obtain a compensation atomic gas cell. A bias magnetic field is applied to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell; The third-axis parameter resonant optical signal is demodulated to obtain the third-axis magnetic field component information of the magnetic field to be measured. This information is then combined with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

[0007] This invention discloses a triaxial magnetic field measurement method based on a single radio frequency (RF) magnetic field. A single RF magnetic field is applied to the atomic gas cell according to its coordinate system, ensuring the RF magnetic field direction aligns with the coordinate system. Resonance can be induced using only a single RF magnetic field source, reducing interaxial crosstalk and sensitivity loss caused by multiple magnetic field modulations. Simultaneously, pre-acquired linearly polarized light is controlled for optical pumping according to the atomic gas cell's coordinate system, ensuring the optical pumping direction is aligned with the coordinate system and establishing a unified reference for subsequent measurements, avoiding the complexity introduced by multiple optical paths. Then, the biaxial parametric resonant optical signal of the magnetic field under test is acquired and demodulated based on the polarized atomic gas cell. The signal strength is enhanced using the resonant state. The first and second axis components are realized using only a single RF magnetic field. Information extraction avoids multi-frequency modulation or complex detection mechanisms. Subsequently, a compensation magnetic field is applied to the polarized atomic gas cell based on the first and second axis magnetic field component information to specifically cancel the measured components, optimizing the measurement environment and creating conditions for third-axis measurement. Then, a bias magnetic field is applied to the compensation atomic gas cell according to the coordinate system to ensure that the bias direction is in a specific plane. The system is sensitive to the third axis with only a single bias, simplifying the bias mechanism and reducing additional hardware. Finally, the third-axis parameter resonant optical signal is demodulated to obtain the third-axis magnetic field component information, and the information of the first two axes is integrated to complete the triaxial measurement. The entire process relies on only a single radio frequency magnetic field, which significantly reduces system complexity and inter-axis interference, and improves the sensitivity of magnetic field measurement.

[0008] As a preferred example, before applying a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized, the following steps are included: The light propagation direction of the atomic gas cell is obtained, and the light propagation direction is defined as the direction of the first coordinate axis; Select a reference direction from any direction perpendicular to the first coordinate axis, and define the reference direction as the direction of the second coordinate axis; The direction of the third coordinate axis is determined by the right-hand rule based on the directions of the first and second coordinate axes. Using the center of the atomic gas chamber as the origin, a coordinate system for the atomic gas chamber is constructed based on the atomic gas chamber, the direction of the first coordinate axis, the direction of the second coordinate axis, and the direction of the third coordinate axis. The direction of the third coordinate axis is taken as the optical polarization direction, and the pre-acquired pump light is adjusted according to the optical polarization direction to obtain linearly polarized light polarized in the optical polarization direction.

[0009] The above scheme constructs a coordinate system with the center of the atomic gas cell as the origin, which provides a unified reference point, enabling all magnetic field component measurements to be based on the same system and reducing positional deviations. The direction of the third coordinate axis is used as the direction of light polarization, which optimizes the selection of the light polarization direction because the third axis is orthogonal to the light propagation plane, minimizing interference. The pump light is adjusted according to the light polarization direction, which ensures that the linearly polarized light is polarized in the specified direction, efficiently achieving atomic polarization, improving the pumping effect and subsequent measurement accuracy.

[0010] As a preferred example, the step of applying a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized includes: The spin transverse relaxation rate of atoms in the atomic chamber is obtained, and the radio frequency magnetic field frequency is determined based on the spin transverse relaxation rate and the pre-acquired signal response bandwidth. A single radio frequency magnetic field is generated according to the preset magnetic field amplitude and the radio frequency magnetic field frequency, and the single radio frequency magnetic field is applied to the atomic gas cell along the direction of the third coordinate axis to obtain the atomic gas cell to be polarized.

[0011] The above-described method for obtaining the spin transverse relaxation rate of atoms within the atomic gas chamber helps quantify the dynamic characteristics of the atomic system, providing a basis for frequency setting. The radio frequency magnetic field frequency is determined based on the spin transverse relaxation rate and the pre-acquired signal response bandwidth, ensuring that the frequency setting matches the atomic relaxation time and system response characteristics, avoiding resonance shift or signal distortion. A single radio frequency magnetic field is generated based on the preset magnetic field amplitude and frequency, maintaining the magnetic field strength within a reasonable range. This single radio frequency magnetic field is then applied to the atomic gas chamber along the third coordinate axis, ensuring the magnetic field acts directionally on a specific coordinate axis, promoting effective resonance. Finally, the atomic gas chamber to be polarized is obtained, providing a stable basis for subsequent measurements.

[0012] As a preferred example, the step of controlling the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell, includes: The linearly polarized light is guided along the first coordinate axis and incident into the atomic gas chamber to be polarized. The atoms in the atom chamber to be polarized are optically pumped by the linearly polarized light to form an arranged polarized atomic state, thereby obtaining a polarized atom chamber.

[0013] The above scheme controls the pre-acquired linearly polarized light to optically pump atoms according to the coordinate system of the atomic gas cell. It utilizes the directional consistency of the coordinate system to avoid the low pumping efficiency caused by the deviation of the light propagation direction. The linearly polarized light is guided into the atomic gas cell to be polarized along the first coordinate axis. By guiding the light along a specific coordinate axis, it is ensured that the light energy directly and effectively enters the gas cell, reducing energy loss. The atoms are optically pumped by the linearly polarized light, and the polarization process is promoted by directly using the polarization characteristics of the light. This causes the atoms to form an ordered arrangement of polarized atomic states, realizing the ordered arrangement of atomic spins and providing a stable basis for subsequent magnetic field resonance. The resulting polarized atomic gas cell is a fully prepared gas cell state, ensuring measurement accuracy.

[0014] As a preferred example, the step of acquiring the biaxial parametric resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and demodulating the biaxial parametric resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured, includes: When the polarized atomic gas cell is within the magnetic field to be measured, linearly polarized light transmitted through the polarized atomic gas cell is obtained; The linearly polarized light transmitted through the polarized atomic gas cell is differentially detected by a balanced zero-difference detection method to obtain a biaxial parametric resonant optical signal. The biaxial parametric resonant optical signal is converted into a biaxial parametric resonant differential electrical signal, and the biaxial parametric resonant differential electrical signal is amplified to obtain the biaxial parametric resonant electrical signal to be processed. Based on the radio frequency of the single radio frequency magnetic field, the fundamental frequency demodulation of the dual-axis parametric resonant electrical signal is performed to obtain the second axis magnetic field component information of the magnetic field under test in the second coordinate axis direction; The biaxial parameter resonant electrical signal is demodulated by second harmonic based on the frequency of the radio frequency magnetic field to obtain the first axis magnetic field component information of the magnetic field under test in the first coordinate axis direction.

[0015] The above scheme acquires linearly polarized light transmitted through the polarized atomic gas cell when the polarized atomic gas cell is within the magnetic field to be measured, ensuring direct capture of optical signals under magnetic field conditions and reflecting the real-time influence of the magnetic field on atoms. Differential detection of the linearly polarized light is performed using a balanced zero-difference detection method, utilizing the differential mechanism to suppress common-mode noise and improve the signal-to-noise ratio and stability. The dual-axis parametric resonant optical signal is converted into a dual-axis parametric resonant differential electrical signal, achieving a reliable transition from optical to electrical signals. The dual-axis parametric resonant differential electrical signal is amplified to enhance signal strength for subsequent processing. The fundamental frequency demodulation of the dual-axis parametric resonant electrical signal is performed based on the radio frequency magnetic field frequency of the single radio frequency magnetic field, extracting the second axis component at a specific frequency to avoid interference from other frequencies. Second harmonic demodulation of the dual-axis parametric resonant electrical signal is performed based on the radio frequency magnetic field frequency, utilizing the harmonic characteristics to distinguish the first axis component. Different demodulation methods isolate inter-axis signals, ensuring the independence and accuracy of component information.

[0016] As a preferred example, the step of applying a compensation magnetic field to the polarized atomic gas cell based on the first axial magnetic field component information and the second axial magnetic field component information to obtain a compensation atomic gas cell includes: Based on the first axis magnetic field component information, determine the first magnetic field compensation value and the first magnetic field compensation direction; Based on the second axis magnetic field component information, a second magnetic field compensation value and a second magnetic field compensation direction are determined; wherein, the first magnetic field compensation direction is opposite to the first coordinate axis direction; and the second magnetic field compensation direction is opposite to the second axis direction. A compensation magnetic field is applied to the polarized atomic gas cell according to the first magnetic field compensation direction and the first magnetic field compensation value, and a compensation magnetic field is applied to the polarized atomic gas cell according to the second magnetic field compensation direction and the second magnetic field compensation value, thereby obtaining a compensation atomic gas cell.

[0017] The above scheme determines the compensation value and direction of the first magnetic field based on the information of the first axis magnetic field component, ensuring that the magnitude and direction of the compensation value are directly customized for the first axis component, avoiding blind compensation. Similarly, it determines the compensation value and direction of the second magnetic field based on the information of the second axis magnetic field component, achieving targeted processing of the second axis component. The design that the first magnetic field compensation direction is opposite to the first coordinate axis direction and the second magnetic field compensation direction is opposite to the second coordinate axis direction ensures that the compensation magnetic field can directly cancel the influence of the original magnetic field. By applying the compensation magnetic field according to the first magnetic field compensation direction and value and the second magnetic field compensation direction and value, the polarized atomic gas cell is synchronously and precisely adjusted, so that the atomic gas cell reaches the compensation state and reduces the residual magnetic field. Finally, a compensated atomic gas cell is obtained, creating an interference-free environment for subsequent three-dimensional measurements.

[0018] As a preferred example, the step of applying a bias magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, and then obtaining the third-axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell, includes: A bias magnetic field with a preset direction and amplitude is applied to the plane formed by the first coordinate axis direction and the second coordinate axis direction, so that the compensation atomic gas chamber is converted into a bias atomic gas chamber; When the biased atomic gas cell is within the magnetic field to be measured, the linearly polarized light passing through the biased atomic gas cell is differentially detected by a balanced zero-difference detection method to obtain the third axis parameter resonance optical signal.

[0019] The above scheme applies a bias magnetic field based on the coordinate system to ensure that the direction is consistent with the coordinate system of the atomic gas cell, thus preventing inter-axis crosstalk. A bias magnetic field with a preset direction and amplitude is applied to the plane formed by the directions of the first and second coordinate axes. This plane is used as a reference plane to convert the compensated atomic gas cell into a biased atomic gas cell, which is convenient for responding to the third axis magnetic field component. When the biased atomic gas cell is in the magnetic field to be measured, linearly polarized light transmitted through the biased atomic gas cell is acquired. The polarization change caused by the magnetic field is detected by light propagation. The linearly polarized light is differentially detected by a balanced zero-difference detection method. The high signal-to-noise ratio of this detection method is used to accurately obtain the resonant optical signal of the third axis parameter, providing a reliable data basis for subsequent demodulation of the third axis component.

[0020] As a preferred example, the demodulation of the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, and the combination of the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured, includes: The third-axis parameter resonant optical signal is converted into a third-axis parameter resonant differential electrical signal, and the third-axis parameter resonant differential electrical signal is amplified to obtain the third-axis parameter resonant electrical signal to be processed. Based on the radio frequency of the single radio frequency magnetic field, the resonant electrical signal of the third axis parameter is demodulated at its fundamental frequency to obtain the third axis magnetic field component information of the magnetic field under test in the direction of the third coordinate axis. The third-axis magnetic field component information is combined with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

[0021] The above scheme converts the third-axis parametric resonant optical signal into a third-axis parametric resonant differential electrical signal, realizing the transformation from optical signal to electronic signal, which facilitates subsequent electronic processing. Amplifying the third-axis parametric resonant differential electrical signal enhances signal strength and detectability, providing high-quality input for demodulation. Demodulating the third-axis parametric resonant electrical signal based on the fundamental frequency of the single-radio frequency magnetic field directly utilizes existing frequency information in the system to extract the third-axis component, avoiding the complexity of introducing additional modulation frequencies. Obtaining the third-axis magnetic field component information of the magnetic field under test along the third coordinate axis ensures accurate acquisition of the third-axis data. Combining the third-axis magnetic field component information with the first-axis and second-axis magnetic field component information, and integrating all component information, achieves complete triaxial magnetic field measurement, thereby improving the overall efficiency and reliability of the system.

[0022] On the other hand, the present invention discloses a triaxial magnetic field measurement system based on a single radio frequency magnetic field, which is suitable for atomic gas cells filled with working atoms; the triaxial magnetic field measurement system includes a single radio frequency application component, an optical pumping component, a photoelectric detection component, a magnetic field compensation component, a bias component, and a triaxial measurement component; The single-radio frequency application component is used to apply a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized; The optical pumping component is used to control the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell. The photoelectric detection component is used to acquire the biaxial parametric resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and to demodulate the biaxial parametric resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. The magnetic field compensation component is used to apply a compensation magnetic field to the polarized atomic gas cell according to the first axis magnetic field component information and the second axis magnetic field component information to obtain a compensation atomic gas cell. The biasing component is used to apply a bias magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell; The triaxial measurement component is used to demodulate the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, so as to combine the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the triaxial magnetic field component information of the magnetic field to be measured.

[0023] This invention discloses a triaxial magnetic field measurement system based on a single radio frequency (RF) magnetic field. A single RF magnetic field is applied to the atomic gas cell according to its coordinate system, ensuring the RF magnetic field direction aligns with the coordinate system. Resonance can be induced using only a single RF magnetic field source, reducing interaxial crosstalk and sensitivity loss caused by multiple magnetic field modulations. Simultaneously, pre-acquired linearly polarized light is controlled for optical pumping according to the atomic gas cell's coordinate system, ensuring the optical pumping direction is aligned with the coordinate system. This establishes a unified reference for subsequent measurements and avoids the complexity introduced by multiple optical paths. Then, the biaxial parametric resonant optical signal of the magnetic field under test is acquired and demodulated based on the polarized atomic gas cell. The signal strength is enhanced using the resonant state. The first and second axis components are achieved using only a single RF magnetic field. Information extraction avoids multi-frequency modulation or complex detection mechanisms. Subsequently, a compensation magnetic field is applied to the polarized atomic gas cell based on the first and second axis magnetic field component information to specifically cancel the measured components, optimizing the measurement environment and creating conditions for third-axis measurement. Then, a bias magnetic field is applied to the compensation atomic gas cell according to the coordinate system to ensure that the bias direction is in a specific plane. The system is sensitive to the third axis with only a single bias, simplifying the bias mechanism and reducing additional hardware. Finally, the third-axis parameter resonant optical signal is demodulated to obtain the third-axis magnetic field component information, and the information of the first two axes is integrated to complete the triaxial measurement. The entire process relies on only a single radio frequency magnetic field, which significantly reduces system complexity and inter-axis interference, and improves the sensitivity of magnetic field measurement.

[0024] As a preferred example, the triaxial magnetic field measurement system based on a single radio frequency magnetic field further includes an optical guiding mechanism; the optical guiding mechanism includes a coordinate system unit and an optical adjustment unit; The coordinate system unit is used to obtain the light propagation direction of the atomic gas chamber, and define the light propagation direction as the first coordinate axis direction; select a reference direction from any direction perpendicular to the first coordinate axis, and define the reference direction as the second coordinate axis direction; determine the third coordinate axis direction according to the first coordinate axis direction and the second coordinate axis direction by the right-hand rule; take the center of the atomic gas chamber as the origin, and construct the coordinate system of the atomic gas chamber according to the atomic gas chamber, the first coordinate axis direction, the second coordinate axis direction, and the third coordinate axis direction; The light adjustment unit is used to take the direction of the third coordinate axis as the light polarization direction, and adjust the pre-acquired pump light according to the light polarization direction to obtain linearly polarized light polarized in the light polarization direction.

[0025] The above scheme constructs a coordinate system with the center of the atomic gas cell as the origin, which provides a unified reference point, enabling all magnetic field component measurements to be based on the same system and reducing positional deviations. The direction of the third coordinate axis is used as the direction of light polarization, which optimizes the selection of the light polarization direction because the third axis is orthogonal to the light propagation plane, minimizing interference. The pump light is adjusted according to the light polarization direction, which ensures that the linearly polarized light is polarized in the specified direction, efficiently achieving atomic polarization, improving the pumping effect and subsequent measurement accuracy. Attached Figure Description

[0026] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating a triaxial magnetic field measurement method based on a single radio frequency magnetic field provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a vector magnetic detection device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a method for measuring the transverse component of a magnetic field based on an atomic gas cell, provided by an embodiment of the present invention. Figure 4 This is a schematic diagram of a method for measuring the longitudinal component of a magnetic field based on an atomic gas cell, provided by an embodiment of the present invention. Figure 5 This is a schematic flowchart of a triaxial magnetic field measurement method based on time-division multiplexing provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of a three-axis magnetic field measurement system based on a single radio frequency magnetic field provided in an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Reference Figure 1 To improve the sensitivity of magnetic field measurements, this embodiment provides a triaxial magnetic field measurement method based on a single radio frequency magnetic field, which mainly includes: Step 101: Apply a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized; Step 102: Control the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining the polarized atomic gas cell; Step 103: Obtain the biaxial parametric resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and demodulate the biaxial parametric resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. Step 104: Apply a compensation magnetic field to the polarized atomic gas cell according to the first axial magnetic field component information and the second axial magnetic field component information to obtain a compensation atomic gas cell; Step 105: Apply a bias magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell; Step 106: Demodulate the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, and combine it with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

[0030] This embodiment provides, for the purpose of measuring the magnetic field, the following: Figure 2 The image shows a vector magnetic probe based on helium-4 atoms, including an atomic gas chamber. (Example:) Figure 2 As shown, the vector magnetic detection device includes an optical preparation module, a radio frequency magnetic field generation module, a helium-4 atomic gas chamber, a magnetic field control module, and a signal detection and processing module. The optical preparation module provides at least one beam of light to the atomic gas chamber to achieve optical pumping and signal detection of the helium-4 atomic ensemble. The helium-4 atomic gas chamber contains a helium-4 atomic ensemble, used to generate atomic spin responses sensitive to external magnetic fields. The radio frequency magnetic field generation module applies a single radio frequency magnetic field within the atomic gas chamber region to drive the atomic system to parametric resonance. The magnetic field control module sets or compensates for the external magnetic field environment under different measurement modes. The signal detection and processing module acquires the optical signal changes caused by atomic parametric resonance and extracts triaxial magnetic field component information related to the triaxial components of the magnetic field to be measured. Preferably, the helium-4 atomic gas chamber and its surrounding area are equipped with a magnetic shielding device to weaken the interference of the external environmental magnetic field on the atomic ensemble, thereby providing a near-zero or low magnetic field working environment for the single radio frequency magnetic field parametric resonance measurement. The modules described above work together in terms of spatial configuration and functional arrangement, enabling the device to perform triaxial magnetic field measurements while maintaining a compact structure.

[0031] In this first embodiment, before optically pumping the atoms to obtain a polarized atom gas cell, the following steps are also included: S1: Obtain the light propagation direction of the atomic gas cell, and define the light propagation direction as the direction of the first coordinate axis; S2: Select a reference direction in any direction perpendicular to the first coordinate axis, and define the reference direction as the direction of the second coordinate axis; S3: Determine the direction of the third coordinate axis based on the direction of the first coordinate axis and the direction of the second coordinate axis using the right-hand rule; S4: Using the center of the atomic gas chamber as the origin, construct a coordinate system for the atomic gas chamber based on the atomic gas chamber, the direction of the first coordinate axis, the direction of the second coordinate axis, and the direction of the third coordinate axis; S5: Take the direction of the third coordinate axis as the light polarization direction, and adjust the pre-acquired pump light according to the light polarization direction to obtain linearly polarized light polarized in the light polarization direction.

[0032] In this embodiment, to describe the direction and components of the magnetic field, a Cartesian coordinate system based on the atomic gas cell is established. The propagation direction of the linearly polarized light used for optical pumping within the atomic gas cell is defined as the direction of the first coordinate axis. For example, the direction of the first coordinate axis can be set as... The direction of polarization of the linearly polarized light before it enters the atomic gas cell is defined as the direction of the third coordinate axis. For example, the direction of the third coordinate axis can be set as... The first coordinate axis direction; or a reference direction is selected in any direction perpendicular to the first coordinate axis, and the reference direction is defined as the second coordinate axis direction; the third coordinate axis direction is determined by the right-hand rule based on the first coordinate axis direction and the second coordinate axis direction; and the third coordinate axis direction is defined as the light polarization direction.

[0033] After establishing a Cartesian coordinate system based on the atomic gas cell, linearly polarized light needs to be generated to prepare the atomic gas cell into an array of polarized atomic states sensitive to changes in the external magnetic field. This linearly polarized light then enters the atomic gas cell and optically pumps the helium-4 atomic ensemble within it. Through resonant excitation and relaxation processes, the atomic ensemble is prepared into an array of polarized atomic states sensitive to changes in the external magnetic field. This polarized state can generate a stable parametric resonance response under subsequent radio frequency magnetic field driving. Simultaneously, this linearly polarized light also serves as a probe light, used to read out the changes in optical signals caused by atomic parametric resonance after passing through the atomic gas cell.

[0034] Specifically, in this embodiment, an optical preparation module is provided in the vector magnetic detection device to generate and adjust linearly polarized light. This module includes a light source, a polarization control component, and an optical path guiding component. The light source is a laser that matches the transition energy levels of helium-4 atoms, generating light that is similar to the energy levels of helium-4 atoms. The pump light is generated by the resonant transition line; and the polarization control component inputs the pump light into the polarization control component, adjusting its polarization direction to the direction of the third coordinate axis (i.e., the original direction). (Axis direction), to obtain linearly polarized light polarized along the direction of the third coordinate axis; through the optical path guiding component, the above linearly polarized light is directed along the direction of the first coordinate axis (i.e., the original axis direction). (Axial direction) guides and injects into the atomic gas chamber.

[0035] The above steps establish a coordinate system with the center of the atomic gas cell as the origin, providing a unified reference point and ensuring that all magnetic field component measurements are based on the same system, reducing positional deviations. The direction of the third coordinate axis is used as the light polarization direction, which optimizes the selection of the light polarization direction because the third axis is orthogonal to the light propagation plane, minimizing interference. The pump light is adjusted according to the light polarization direction, ensuring that the linearly polarized light is polarized in the specified direction, efficiently achieving atomic polarization, and improving the pumping effect and subsequent measurement accuracy.

[0036] In this embodiment, step 101 includes: Step 1011: Obtain the spin transverse relaxation rate of the atoms in the atomic chamber, and determine the radio frequency magnetic field frequency based on the spin transverse relaxation rate and the pre-acquired signal response bandwidth.

[0037] Step 1012: Generate a single radio frequency magnetic field according to the preset magnetic field amplitude and the radio frequency magnetic field frequency, and apply the single radio frequency magnetic field to the atomic gas cell along the direction of the third coordinate axis to obtain the atomic gas cell to be polarized.

[0038] Before applying a single radio frequency magnetic field, this embodiment first obtains the spin transverse relaxation rate of helium-4 atoms within the atomic gas chamber. Helium-4 atoms have a spin transverse relaxation rate in the kilohertz range in the metastable state, a parameter that can be obtained through theoretical calculation or experimental measurement. Simultaneously, the response bandwidth of the signal detection and processing module is pre-acquired. This bandwidth refers to the frequency range within which the entire signal acquisition chain, including the photodetector, transimpedance amplifier, and demodulation circuit, can effectively respond. Based on the atomic spin transverse relaxation rate and the response bandwidth of the signal detection and processing module, the driving frequency of the single radio frequency magnetic field is determined: this frequency is set to a range greater than the atomic spin transverse relaxation rate and less than the response bandwidth of the signal detection and processing module. This frequency range ensures that the atomic ensemble can generate parametric resonance following the changes in the radio frequency field, and that the optical signal changes caused by the parametric resonance can be effectively acquired by the detection system.

[0039] In this embodiment, a radio frequency magnetic field generation module is provided in the magnetic field vector detection device to generate and apply a single radio frequency magnetic field. The radio frequency magnetic field generation module includes a radio frequency driving device and a magnetic field generating structure disposed around the atomic gas cell. The magnetic field generating structure is preferably a three-dimensional Helmholtz coil, capable of generating a uniform magnetic field along the first, second, and third coordinate axes. The amplitude of the single radio frequency magnetic field is set to the order of hundreds of nanoteslas, for example, 100 nanoteslas. This amplitude range can effectively drive the atomic system to parametric resonance without disrupting the atomic polarization state. The radio frequency driving device generates a corresponding radio frequency current according to the determined frequency and amplitude parameters, driving the three-dimensional Helmholtz coil to generate a single-frequency radio frequency magnetic field.

[0040] The generated single-radio magnetic field is directed along the third coordinate axis (i.e., the original...) An axial direction (aligned with the polarization direction of linearly polarized light) is applied to the atomic gas cell region. This applied direction is also the magnetic field direction of a single radio frequency magnetic field; in a near-zero magnetic field environment, the single radio frequency magnetic field periodically modulates the spin evolution process of the atomic system. Specifically, as... Figure 3 As shown, when the measurable component of the magnetic field to be measured is located... In the plane, the single radio frequency magnetic field The spin evolution process of a periodically modulated atomic system causes the optically pumped, polarized atomic states to produce a parametric resonance response under the influence of an external magnetic field. When a component exists within the plane, this magnetic field component modulates the parametric resonance signal by influencing the atomic spin dynamics. This parametric resonance signal is then demodulated. In-plane mutually orthogonal component information is mapped into the optical signal, thereby achieving [the desired signal] without introducing additional radio frequency magnetic fields or changing the optical configuration. axis, Two magnetic field components in the axial direction , Measurement.

[0041] Preferably, the atomic gas chamber and its surrounding area are equipped with a magnetic shielding device to reduce the interference of the external environmental magnetic field on the atomic ensemble. The magnetic field control module is used to adjust the static magnetic field environment within the atomic gas chamber area, and the environmental magnetic field has been compensated to a near-zero level before the application of the radio frequency magnetic field to ensure that the system operates under ideal near-zero magnetic field conditions.

[0042] The steps described above, which obtain the spin transverse relaxation rate of atoms within the atomic gas chamber, help quantify the dynamic characteristics of the atomic system and provide a basis for frequency setting. The radio frequency magnetic field frequency is determined based on the spin transverse relaxation rate and the pre-acquired signal response bandwidth, ensuring that the frequency setting matches the atomic relaxation time and system response characteristics to avoid resonance shift or signal distortion. A single radio frequency magnetic field is generated based on the preset magnetic field amplitude and frequency, maintaining the magnetic field strength within a reasonable range. This single radio frequency magnetic field is then applied to the atomic gas chamber along the third coordinate axis, ensuring that the magnetic field acts directionally on a specific coordinate axis to promote effective resonance. Finally, the atomic gas chamber to be polarized is obtained, providing a stable basis for subsequent measurements.

[0043] In this embodiment, step 102 includes: Step 1021: Guide the linearly polarized light along the first coordinate axis direction into the atom gas chamber to be polarized; Step 1022: The atoms in the atom chamber to be polarized are optically pumped by the linearly polarized light to form an arranged polarized atomic state, thereby obtaining a polarized atom chamber.

[0044] In this embodiment, the optical path guiding component in the optical fabrication module guides the optical path to the direction of the third coordinate axis (i.e., the original direction). Linearly polarized light polarized along the first coordinate axis (i.e., the original axis direction) After being guided (in the axial direction) and incident into the atom gas chamber to be polarized, the linearly polarized light is used as both pump light and probe light.

[0045] In this embodiment, the atomic chamber is filled with helium-4 atoms. The frequency of the linearly polarized light is set to match that of the helium-4 atoms. Transition line resonance is employed to ensure energy level matching with atoms, enabling a highly efficient optical pumping process. The linearly polarized light enters the atom chamber to be polarized and optically pumps the helium-4 atomic ensemble. Under the influence of the resonant light, the atoms undergo optical excitation and spontaneous emission relaxation, gradually forming a specific spin distribution at metastable energy levels. Through continuous optical pumping, the atomic ensemble is ultimately prepared into an array-polarized atomic state sensitive to changes in the external magnetic field. After completing the optical pumping process, the helium-4 atomic ensemble within the atomic chamber is in a stable array-polarized atomic state; this atomic chamber is then called a polarized atomic chamber. This polarized state can generate a parametric resonance response under subsequent radio frequency magnetic field driving, and this response exhibits distinguishable modulation characteristics to changes in each component of the magnetic field.

[0046] The above steps control the pre-acquired linearly polarized light to optically pump the atoms according to the coordinate system of the atomic gas cell. This utilizes the directional consistency of the coordinate system to avoid low pumping efficiency caused by deviations in the light propagation direction. The linearly polarized light is guided along the first coordinate axis and incident into the atomic gas cell to be polarized. By guiding the light along a specific coordinate axis, it is ensured that the light energy directly and effectively enters the gas cell, reducing energy loss. The atoms are optically pumped by the linearly polarized light, and the polarization process is promoted by directly utilizing the polarization characteristics of the light. This causes the atoms to form an ordered arrangement of polarized atomic states, achieving an ordered arrangement of atomic spins and providing a stable foundation for subsequent magnetic field resonance. The polarized atomic gas cell is obtained, and finally, a fully prepared gas cell state is achieved, ensuring measurement accuracy.

[0047] In this embodiment, step 103 includes: Step 1031: When the polarized atomic gas cell is in the magnetic field to be measured, acquire the linearly polarized light transmitted through the polarized atomic gas cell; Step 1032: Differential detection is performed on the linearly polarized light transmitted through the polarized atomic gas cell using a balanced zero-difference detection method to obtain a biaxial parameter resonance optical signal; Step 1033: Convert the biaxial parametric resonant optical signal into a biaxial parametric resonant differential electrical signal, and amplify the biaxial parametric resonant differential electrical signal to obtain the biaxial parametric resonant electrical signal to be processed; Step 1034: Demodulate the fundamental frequency of the dual-axis parametric resonant electrical signal according to the radio frequency magnetic field frequency of the single radio frequency magnetic field to obtain the second axis magnetic field component information of the magnetic field to be measured in the second coordinate axis direction; Step 1035: Demodulate the biaxial parameter resonant electrical signal by second harmonic according to the frequency of the radio frequency magnetic field to obtain the first axis magnetic field component information of the magnetic field to be measured in the first coordinate axis direction.

[0048] In this embodiment, after obtaining a polarized atomic gas cell by applying a single-frequency magnetic field, a magnetic field vector detection device, including the polarized atomic gas cell, is placed within the magnetic field to be measured, so as to collect and process the optical signal transmitted through the polarized atomic gas cell. Specifically, the polarization direction of the linearly polarized light changes due to the atomic parameter resonance process after passing through the atomic gas cell. The signal detection is preferably in a balanced zero-difference detection mode, used for... Figure 3 The generated optical signal is shown Differential detection is performed to extract information on changes in the optical polarization direction, and the optical signal is converted into an electrical signal via a transimpedance amplifier. Signal processing involves multi-channel demodulation of the electrical signal to extract different harmonic modulation components caused by parametric resonance. The multi-channel demodulation includes: using the radio frequency magnetic field frequency as a reference, demodulating the electrical signal at its fundamental frequency and second harmonic frequency, thereby simultaneously outputting signals in two demodulation channels. axis, Signal components that are proportional to the axial direction.

[0049] The above steps involve acquiring linearly polarized light transmitted through the polarized atomic gas cell when it is within the magnetic field to be measured, ensuring direct capture of optical signals under magnetic field conditions and reflecting the real-time influence of the magnetic field on atoms; differential detection of the linearly polarized light using a balanced zero-difference detection method, utilizing the differential mechanism to suppress common-mode noise and improve the signal-to-noise ratio and stability; converting the biaxial parametric resonant optical signal into a biaxial parametric resonant differential electrical signal, achieving a reliable transition from optical to electrical signals, and amplifying the biaxial parametric resonant differential electrical signal to enhance signal strength for subsequent processing; fundamental frequency demodulation of the biaxial parametric resonant electrical signal based on the radio frequency magnetic field frequency of the single radio frequency magnetic field, extracting the second axis component at a specific frequency to avoid interference from other frequencies; second harmonic demodulation of the biaxial parametric resonant electrical signal based on the radio frequency magnetic field frequency, using harmonic characteristics to distinguish the first axis component, and isolating interaxial signals through different demodulation methods to ensure the independence and accuracy of component information.

[0050] In this embodiment, step 104 includes: Step 1041: Determine the first magnetic field compensation value and the first magnetic field compensation direction based on the first axis magnetic field component information.

[0051] Step 1042: Determine the second magnetic field compensation value and the second magnetic field compensation direction based on the second axis magnetic field component information; wherein, the first magnetic field compensation direction is opposite to the first coordinate axis direction; and the second magnetic field compensation direction is opposite to the second coordinate axis direction.

[0052] Step 1043: Apply a compensation magnetic field to the polarized atomic gas chamber according to the first magnetic field compensation direction and the first magnetic field compensation value, and apply a compensation magnetic field to the polarized atomic gas chamber according to the second magnetic field compensation direction and the second magnetic field compensation value to obtain a compensation atomic gas chamber.

[0053] In this embodiment, the magnetic field to be measured is obtained in the first coordinate axis direction (i.e., the original direction). After obtaining the first axis magnetic field component information (in the first coordinate axis direction) and the second axis magnetic field component information (in the second coordinate axis direction), a first magnetic field compensation value to be applied in the first coordinate axis direction is determined based on the first axis magnetic field component information. The principle for setting this compensation value is that it is equal in magnitude to the first axis magnetic field component to be measured, so as to cancel the original magnetic field component in that direction. Simultaneously, the first magnetic field compensation direction is determined based on the first axis magnetic field component information. Since the purpose of compensation is to cancel the original component, the first magnetic field compensation direction is set to be opposite to the first coordinate axis direction, i.e., along the negative direction of the first coordinate axis.

[0054] Similarly, based on the second axis magnetic field component information, a second magnetic field compensation value to be applied in the second coordinate axis direction is determined. This compensation value is equal in magnitude to the second axis magnetic field component to be measured. The second magnetic field compensation direction is determined based on the second axis magnetic field component information. The second magnetic field compensation direction is set to be opposite to the second coordinate axis direction, i.e., along the negative direction of the second coordinate axis.

[0055] In this embodiment, the application of the compensation magnetic field is achieved through a magnetic field control module. The magnetic field control module controls a three-dimensional Helmholtz coil positioned around the atomic gas chamber, which generates a uniform magnetic field along the first, second, and third coordinate axes. Based on the determined first magnetic field compensation value and first magnetic field compensation direction, the magnetic field control module drives the first axis coil of the three-dimensional Helmholtz coil to apply a compensation magnetic field of magnitude equal to the first magnetic field compensation value along the negative direction of the first coordinate axis. Simultaneously, based on the determined second magnetic field compensation value and second magnetic field compensation direction, the magnetic field control module drives the second axis coil of the three-dimensional Helmholtz coil to apply a compensation magnetic field of magnitude equal to the second magnetic field compensation value along the negative direction of the second coordinate axis.

[0056] After the aforementioned compensating magnetic field is applied, magnetic field vector superposition occurs within the atomic gas cell region. In the direction of the first coordinate axis, the first magnetic field compensation value is equal in magnitude and opposite in direction to the original first axis measured magnetic field component, and the two cancel each other out, causing the total magnetic field in the direction of the first coordinate axis to approach zero. Along the direction of the second coordinate axis, the second magnetic field compensation value is equal in magnitude and opposite in direction to the original second axis measured magnetic field component, and the two cancel each other out, causing the total magnetic field in the direction of the second coordinate axis to approach zero.

[0057] After the above compensation, the transverse magnetic field components (i.e., the first and second axis directions) within the atomic gas cell region have been canceled to near zero. This atomic gas cell is called the compensated atomic gas cell. This state creates ideal initial conditions for applying a bias magnetic field and measuring the third axis magnetic field component in the subsequent longitudinal working mode, eliminating the interference of the transverse magnetic field component on the longitudinal measurement.

[0058] The above steps determine the first magnetic field compensation value and direction based on the first axis magnetic field component information, ensuring that the magnitude and direction of the compensation value are directly customized for the first axis component, avoiding blind compensation. Similarly, the second magnetic field compensation value and direction are determined based on the second axis magnetic field component information, achieving targeted processing of the second axis component. The design that the first magnetic field compensation direction is opposite to the first coordinate axis direction and the second magnetic field compensation direction is opposite to the second coordinate axis direction ensures that the compensation magnetic field can directly cancel the influence of the original magnetic field. By applying the compensation magnetic field according to the first magnetic field compensation direction and value and the second magnetic field compensation direction and value, the polarized atomic gas cell is synchronously and precisely adjusted, so that the atomic gas cell reaches the compensation state and reduces the residual magnetic field. Finally, a compensated atomic gas cell is obtained, creating an interference-free environment for subsequent three-dimensional measurements.

[0059] In this embodiment, step 105 includes: Step 1051: Apply a bias magnetic field with a preset direction and amplitude to the plane formed by the first coordinate axis direction and the second coordinate axis direction, so that the compensation atomic gas chamber is converted into a bias atomic gas chamber; Step 1052: When the biased atomic gas cell is in the magnetic field to be measured, differential detection is performed on the linearly polarized light transmitted through the biased atomic gas cell by means of balanced zero-difference detection to obtain the third axis parameter resonance optical signal.

[0060] This embodiment applies a single radio frequency magnetic field within the atomic gas chamber region to drive parametric resonance in the atomic system. Based on compensating for the ambient static magnetic field within the atomic gas chamber region, a bias magnetic field component in a preset direction is introduced to alter the effective magnetic field conditions of the atomic system. In a preferred embodiment, the bias magnetic field component is introduced into a direction orthogonal to the polarization direction of the linearly polarized light. Within a plane. For example... Figure 4 As shown, by The bias magnetic field component is applied in the plane This allows the atomic system to maintain a single radio frequency magnetic field while simultaneously controlling the external magnetic field. The axial component produces a distinguishable parametric resonance response. The direction of introduction of the bias magnetic field component can be set relative to the magnetic field direction of the radio frequency magnetic field or the optical polarization direction of the linearly polarized light, and its specific direction is not limited to a single direction. The magnetic field value of the bias magnetic field component is set to effectively distinguish the atomic parametric resonance conditions without disrupting them. Within the range of the axial magnetic field component response. By setting the direction and value of the bias magnetic field component, the operating mode of the vector magnetic detection device can be switched while keeping the single radio frequency magnetic field parameter unchanged.

[0061] In the bias magnetic field operation mode, based on compensation for the ambient static magnetic field within the atomic gas chamber region, a bias magnetic field component with a preset direction is introduced, thereby altering the effective magnetic field conditions of the atomic system and influencing the external magnetic field of the atomic spin evolution process. The axial component produces a sensitive response. When the external magnetic field is... When a component exists along the axial direction, this component, through its interaction with the bias magnetic field, alters the magnetic field conditions of the atomic system, thereby modulating the parametric resonance process driven by a single radio frequency magnetic field, causing a distinguishable change in the characteristics of the parametric resonance signal. Through this parametric resonance modulation mechanism, the external magnetic field... The axial component is mapped onto the optical signal of the probe light, thereby achieving [the desired effect] while maintaining a single radio frequency magnetic field and optical configuration. Measurement of axial magnetic field components without introducing additional radio frequency magnetic fields or changing the optical configuration.

[0062] The above steps apply a bias magnetic field according to the coordinate system to ensure that the direction is consistent with the coordinate system of the atomic gas cell, preventing inter-axis crosstalk. A bias magnetic field with a preset direction and amplitude is applied to the plane formed by the first coordinate axis and the second coordinate axis, using this plane as a reference plane to convert the compensated atomic gas cell into a biased atomic gas cell, which is convenient for responding to the third axis magnetic field component. When the biased atomic gas cell is in the magnetic field to be measured, linearly polarized light transmitted through the biased atomic gas cell is acquired, and the polarization change caused by the magnetic field is detected by light propagation. The linearly polarized light is differentially detected by a balanced zero-difference detection method. The high signal-to-noise ratio of this detection method is used to accurately obtain the resonant optical signal of the third axis parameter, providing a reliable data basis for subsequent demodulation of the third axis component.

[0063] In this embodiment, step 106 includes: Step 1061: Convert the third-axis parameter resonant optical signal into a third-axis parameter resonant differential electrical signal, and amplify the third-axis parameter resonant differential electrical signal to obtain the third-axis parameter resonant electrical signal to be processed; Step 1062: Demodulate the resonant electrical signal of the third axis parameter according to the radio frequency of the single radio frequency magnetic field to obtain the third axis magnetic field component information of the magnetic field to be measured in the direction of the third coordinate axis; Step 1063: Combine the third-axis magnetic field component information with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

[0064] In this embodiment, optical signals transmitted through the atomic gas cell are acquired, and the changes in optical signals caused by atomic parameter resonance are converted into electrical signals. The signal detection and processing module demodulates and analyzes the electrical signals to identify the parameter resonance modulation characteristics corresponding to the longitudinal operating mode. In the longitudinal operating mode, the signal detection and processing module preferably sets up a fundamental frequency demodulation channel with the radio frequency magnetic field driving frequency as a reference to extract the fundamental frequency modulation component in the parameter resonance signal. In this embodiment, The measurement of the axial magnetic field component still relies entirely on the parametric resonant response driven by a single radio frequency magnetic field, without the need to introduce multiple radio frequency magnetic fields or additional beam configurations, thus avoiding the sensitivity suppression and component crosstalk problems that may be introduced under multi-radio frequency field conditions.

[0065] The above steps convert the third-axis parametric resonant optical signal into a third-axis parametric resonant differential electrical signal, realizing the transformation from optical signal to electronic signal, which facilitates subsequent electronic processing; amplifying the third-axis parametric resonant differential electrical signal enhances signal strength and detectability, providing high-quality input for demodulation; fundamental frequency demodulation of the third-axis parametric resonant electrical signal is performed based on the radio frequency magnetic field frequency of the single radio frequency magnetic field, directly utilizing the existing frequency information in the system to extract the third-axis component, avoiding the complexity of introducing additional modulation frequencies; obtaining the third-axis magnetic field component information of the magnetic field to be measured in the direction of the third coordinate axis ensures the accurate acquisition of third-axis data; combining the third-axis magnetic field component information with the first-axis magnetic field component information and the second-axis magnetic field component information, by integrating all component information, complete triaxial magnetic field measurement is realized, thereby improving the overall efficiency and reliability of the system.

[0066] In this first embodiment, the detection device is switched between different operating modes by switching the bias magnetic field; wherein, the operating mode is divided into acquiring the external magnetic field in the transverse direction. Lateral working mode of component information in two mutually orthogonal directions in a plane and acquisition of external magnetic field in The method employs a longitudinal operating mode to obtain directional component information. Specifically, by switching the operating mode at different time intervals, the three-axis components of the external magnetic field are measured. Throughout the measurement process, the single radio frequency magnetic field and single-beam optical configuration remain unchanged; the three-axis magnetic field information is acquired solely through time-series switching of the operating mode.

[0067] Specifically, during the first time period, the device is operated in a transverse mode, and during the parametric resonance process driven by a single radio frequency magnetic field, the external magnetic field is acquired in the transverse direction. Information on the components in two mutually orthogonal directions within the plane; after completing the measurement of the transverse magnetic field component, based on the obtained measurement results, the magnetic field control module is used to control the magnetic field within the atomic gas chamber region. axis, The axial direction component is compensated to reduce the influence of the transverse magnetic field component on the subsequent longitudinal magnetic field measurement. After completing the measurement and compensation of the transverse planar magnetic field component, a preset bias magnetic field is introduced through the magnetic field control module during the second time period to switch the device to the longitudinal working mode. In the longitudinal working mode, the radio frequency magnetic field and optical configuration are kept unchanged to acquire the external magnetic field. The axial component information is obtained and compensated; the measurement results obtained in different time periods are combined to obtain the triaxial components of the external magnetic field.

[0068] The switching between the transverse and longitudinal operating modes is achieved through a magnetic field control module. This module adjusts the static magnetic field environment within the atomic gas chamber region, allowing the atomic system to correspond to different effective magnetic field conditions at different times, thereby altering the sensitivity direction of the parametric resonance signal to the external magnetic field component. In the time-division multiplexing measurement process, the transverse operating mode is executed before the longitudinal operating mode. This is because prioritizing the measurement and compensation of the external magnetic field component in the transverse plane under transverse operating mode effectively reduces the interference of the transverse magnetic field component on the parametric resonance response under longitudinal operating mode, thus improving the accuracy and stability of the longitudinal magnetic field component measurement. Therefore, in this embodiment, the execution order of the operating modes is as follows: first, the transverse operating mode is executed to complete the measurement and compensation of the transverse magnetic field component, then the longitudinal operating mode is switched to complete the measurement and compensation of the longitudinal magnetic field component, and so on. Figure 5 The working mode switching cycle is shown.

[0069] The above steps achieve the measurement of the three-axis components of the external magnetic field by multiplexing the working mode in time; by measuring and compensating the transverse magnetic field component first, and then measuring and compensating the longitudinal magnetic field component in sequence; only a single radio frequency magnetic field is used in the entire measurement process, avoiding the problem of intrinsic sensitivity reduction caused by the parallel introduction of multiple radio frequency fields; the optical configuration remains unchanged, which is conducive to the miniaturization, stable operation and array expansion of the system.

[0070] On the other hand, refer to Figure 6 This embodiment also discloses a triaxial magnetic field measurement system based on a single radio frequency magnetic field, which is suitable for atomic gas cells filled with working atoms; the triaxial magnetic field measurement system includes a single radio frequency application component 601, an optical pump component 602, a photoelectric detection component 603, a magnetic field compensation component 604, a bias component 605, and a triaxial measurement component 606; The single-radio frequency application component 601 is used to apply a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized. The optical pumping component 602 is used to control the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell. The photoelectric detection component 603 is used to acquire the biaxial parameter resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and demodulate the biaxial parameter resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. The magnetic field compensation component 604 is used to apply a compensation magnetic field to the polarized atomic gas cell according to the first axial magnetic field component information and the second axial magnetic field component information to obtain a compensation atomic gas cell. The biasing component 605 is used to apply a biasing magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell. The triaxial measurement component 606 is used to demodulate the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, so as to combine the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the triaxial magnetic field component information of the magnetic field to be measured.

[0071] In this embodiment, the triaxial magnetic field measurement system further includes an optical guiding mechanism; the optical guiding mechanism includes a coordinate system unit and an optical adjustment unit; The coordinate system unit is used to obtain the light propagation direction of the atomic gas chamber, and define the light propagation direction as the first coordinate axis direction; select a reference direction in a plane perpendicular to the first coordinate axis, and define the reference direction as the second coordinate axis direction; determine the third coordinate axis direction according to the first coordinate axis direction and the second coordinate axis direction by the right-hand rule; take the center of the atomic gas chamber as the origin, and construct the coordinate system of the atomic gas chamber according to the atomic gas chamber, the first coordinate axis direction, the second coordinate axis direction, and the third coordinate axis direction; The light adjustment unit is used to take the direction of the third coordinate axis as the light polarization direction, and adjust the pre-acquired pump light according to the light polarization direction to obtain linearly polarized light polarized in the light polarization direction.

[0072] This embodiment provides a triaxial magnetic field measurement method and system based on a single radio frequency magnetic field. By introducing only a single radio frequency magnetic field and utilizing a parametric resonance mechanism to achieve magnetic field measurement, it avoids the intrinsic sensitivity suppression problem caused by the parallel application of multiple radio frequency magnetic fields in existing vector atomic magnetometers, thus maintaining the inherent high sensitivity measurement characteristics of atomic magnetometers. Simultaneously, a time-division multiplexing-based measurement method is employed to acquire the transverse and longitudinal components of the magnetic field at different time intervals, separating the measurements of different magnetic field components in time and achieving near-isotropic triaxial measurement. Furthermore, maintaining a single radio frequency magnetic field and simplified optical configuration throughout the measurement process eliminates the need for multiple radio frequency fields or complex multi-beam configurations, effectively reducing system structural complexity and debugging difficulty, and improving the engineering feasibility of the device. Since the measurement process does not rely on multiple radio frequency fields or multi-beam configurations, the system's field configuration is compact, which helps reduce the size and power consumption of a single probe and provides a good foundation for subsequent multi-channel array design. Based on the physical properties of the helium-4 atomic system, magnetic field measurement is performed through parametric resonance, achieving triaxial measurement while maintaining operating bandwidth and suppressing inter-axis crosstalk errors.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for measuring triaxial magnetic fields based on a single radio frequency magnetic field, characterized in that, Applicable to atomic gas cells filled with working atoms; the triaxial magnetic field measurement method includes: A single-frequency magnetic field is applied to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized; The pre-acquired linearly polarized light is controlled according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell; The biaxial parametric resonance optical signal of the magnetic field to be measured is obtained by the polarized atomic gas cell, and the biaxial parametric resonance optical signal is demodulated to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. A compensation magnetic field is applied to the polarized atomic gas cell based on the first axis magnetic field component information and the second axis magnetic field component information to obtain a compensation atomic gas cell. A bias magnetic field is applied to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell; The third-axis parameter resonant optical signal is demodulated to obtain the third-axis magnetic field component information of the magnetic field to be measured. This information is then combined with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

2. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 1, characterized in that, Before applying a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized, the following steps are included: The light propagation direction of the atomic gas cell is obtained, and the light propagation direction is defined as the direction of the first coordinate axis; Select a reference direction from any direction perpendicular to the first coordinate axis, and define the reference direction as the direction of the second coordinate axis; The direction of the third coordinate axis is determined by the right-hand rule based on the directions of the first and second coordinate axes. Using the center of the atomic gas chamber as the origin, a coordinate system for the atomic gas chamber is constructed based on the atomic gas chamber, the direction of the first coordinate axis, the direction of the second coordinate axis, and the direction of the third coordinate axis. The direction of the third coordinate axis is taken as the optical polarization direction, and the pre-acquired pump light is adjusted according to the optical polarization direction to obtain linearly polarized light polarized in the optical polarization direction.

3. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 2, characterized in that, The step of applying a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized includes: The spin transverse relaxation rate of atoms in the atomic chamber is obtained, and the radio frequency magnetic field frequency is determined based on the spin transverse relaxation rate and the pre-acquired signal response bandwidth. A single radio frequency magnetic field is generated according to the preset magnetic field amplitude and the radio frequency magnetic field frequency, and the single radio frequency magnetic field is applied to the atomic gas cell along the direction of the third coordinate axis to obtain the atomic gas cell to be polarized.

4. A triaxial magnetic field measurement method based on a single radio frequency magnetic field according to any one of claims 2-3, characterized in that, The step of controlling the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell, includes: The linearly polarized light is guided along the first coordinate axis and incident into the atomic gas chamber to be polarized. The atoms in the atom chamber to be polarized are optically pumped by the linearly polarized light to form an arranged polarized atomic state, thereby obtaining a polarized atom chamber.

5. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 4, characterized in that, The process of acquiring the biaxial parametric resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and demodulating the biaxial parametric resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured, includes: When the polarized atomic gas cell is within the magnetic field to be measured, linearly polarized light transmitted through the polarized atomic gas cell is obtained; The linearly polarized light transmitted through the polarized atomic gas cell is differentially detected by a balanced zero-difference detection method to obtain a biaxial parametric resonant optical signal. The biaxial parametric resonant optical signal is converted into a biaxial parametric resonant differential electrical signal, and the biaxial parametric resonant differential electrical signal is amplified to obtain the biaxial parametric resonant electrical signal to be processed. Based on the radio frequency of the single radio frequency magnetic field, the fundamental frequency demodulation of the dual-axis parametric resonant electrical signal is performed to obtain the second axis magnetic field component information of the magnetic field under test in the second coordinate axis direction; The biaxial parameter resonant electrical signal is demodulated by second harmonic based on the frequency of the radio frequency magnetic field to obtain the first axis magnetic field component information of the magnetic field under test in the first coordinate axis direction.

6. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 5, characterized in that, The step of applying a compensation magnetic field to the polarized atomic gas cell based on the first axial magnetic field component information and the second axial magnetic field component information to obtain a compensation atomic gas cell includes: Based on the first axis magnetic field component information, determine the first magnetic field compensation value and the first magnetic field compensation direction; Based on the second axis magnetic field component information, a second magnetic field compensation value and a second magnetic field compensation direction are determined; wherein, the first magnetic field compensation direction is opposite to the first coordinate axis direction; and the second magnetic field compensation direction is opposite to the second axis direction. A compensation magnetic field is applied to the polarized atomic gas cell according to the first magnetic field compensation direction and the first magnetic field compensation value, and a compensation magnetic field is applied to the polarized atomic gas cell according to the second magnetic field compensation direction and the second magnetic field compensation value, thereby obtaining a compensation atomic gas cell.

7. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 6, characterized in that, The step of applying a bias magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, and then obtaining the third-axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell, includes: A bias magnetic field with a preset direction and amplitude is applied to the plane formed by the first coordinate axis direction and the second coordinate axis direction, so that the compensation atomic gas chamber is converted into a bias atomic gas chamber; When the biased atomic gas cell is within the magnetic field to be measured, differential detection is performed on the linearly polarized light transmitted through the biased atomic gas cell using a balanced zero-difference detection method to obtain the third axis parameter resonant optical signal.

8. The triaxial magnetic field measurement method based on a single radio frequency magnetic field according to claim 7, characterized in that, The demodulation of the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, combined with the first-axis magnetic field component information and the second-axis magnetic field component information, to obtain the three-axis magnetic field component information of the magnetic field to be measured, includes: The third-axis parameter resonant optical signal is converted into a third-axis parameter resonant differential electrical signal, and the third-axis parameter resonant differential electrical signal is amplified to obtain the third-axis parameter resonant electrical signal to be processed. Based on the radio frequency of the single radio frequency magnetic field, the resonant electrical signal of the third axis parameter is demodulated at its fundamental frequency to obtain the third axis magnetic field component information of the magnetic field under test in the direction of the third coordinate axis. The third-axis magnetic field component information is combined with the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the three-axis magnetic field component information of the magnetic field to be measured.

9. A triaxial magnetic field measurement system based on a single radio frequency magnetic field, characterized in that, Suitable for atomic gas cells filled with working atoms; the triaxial magnetic field measurement system includes a single radio frequency application component, an optical pump component, a photoelectric detection component, a magnetic field compensation component, a bias component, and a triaxial measurement component; The single-radio frequency application component is used to apply a single-radio frequency magnetic field to the atomic gas cell according to the coordinate system of the atomic gas cell to obtain the atomic gas cell to be polarized; The optical pumping component is used to control the pre-acquired linearly polarized light according to the coordinate system to optically pump the atomic gas cell to be polarized, thereby obtaining a polarized atomic gas cell. The photoelectric detection component is used to acquire the biaxial parametric resonance optical signal of the magnetic field to be measured based on the polarized atomic gas cell, and to demodulate the biaxial parametric resonance optical signal to obtain the first axis magnetic field component information and the second axis magnetic field component information of the magnetic field to be measured. The magnetic field compensation component is used to apply a compensation magnetic field to the polarized atomic gas cell according to the first axis magnetic field component information and the second axis magnetic field component information to obtain a compensation atomic gas cell. The biasing component is used to apply a bias magnetic field to the compensated atomic gas cell according to the coordinate system to obtain a biased atomic gas cell, so as to obtain the third axis parameter resonance optical signal of the magnetic field to be measured through the biased atomic gas cell; The triaxial measurement component is used to demodulate the third-axis parameter resonant optical signal to obtain the third-axis magnetic field component information of the magnetic field to be measured, so as to combine the first-axis magnetic field component information and the second-axis magnetic field component information to obtain the triaxial magnetic field component information of the magnetic field to be measured.

10. A triaxial magnetic field measurement system based on a single radio frequency magnetic field according to claim 9, characterized in that, It also includes a light guiding mechanism; the light guiding mechanism includes a coordinate system unit and a light adjustment unit; The coordinate system unit is used to obtain the light propagation direction of the atomic gas chamber, and define the light propagation direction as the first coordinate axis direction; select a reference direction from any direction perpendicular to the first coordinate axis, and define the reference direction as the second coordinate axis direction; determine the third coordinate axis direction according to the first coordinate axis direction and the second coordinate axis direction by the right-hand rule; take the center of the atomic gas chamber as the origin, and construct the coordinate system of the atomic gas chamber according to the atomic gas chamber, the first coordinate axis direction, the second coordinate axis direction, and the third coordinate axis direction; The light adjustment unit is used to take the direction of the third coordinate axis as the light polarization direction, and adjust the pre-acquired pump light according to the light polarization direction to obtain linearly polarized light polarized in the light polarization direction.

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