A packaging structure of a magnetometer and a magnetometer

Abstract

The present application relates to the technical field of magnetometers, and provides a packaging structure of a magnetometer, including: a pump light part, including a collimating sleeve, a laser generating device and a collimating lens are arranged in the collimating sleeve; a magnetic field detection part, including a retardation wave plate chamber, an atomic gas chamber and a photosensitive device chamber, both ends of the atomic gas chamber are respectively connected to the retardation wave plate chamber and the photosensitive device chamber, the collimating sleeve, the retardation wave plate chamber, the atomic gas chamber and the photosensitive device chamber are internally communicated, wherein, a wave plate is arranged in the retardation wave plate chamber, and a photodiode is arranged in the photosensitive device chamber; a plug-in part is arranged at one end of the retardation wave plate chamber far away from the atomic gas chamber, and the pump light part and the magnetic field detection part are detachably connected through a connector. In the packaging structure provided by the present application, all wiring adopts a twisted form and is connected by a magnetic shielding wire, which can improve the sensitivity and bandwidth of the absolute scalar magnetometer, reduce the weight and volume of the absolute scalar magnetometer, and solve the problems of low measurement accuracy and poor stability of the laser pumped magnetometer.

Description

Technical Field

[0001] The present application relates to the technical field of magnetometers, and more specifically, to a packaging structure of a magnetometer and a magnetometer. Background Art

[0002] A magnetometer is a basic instrument for magnetic detection and ground magnetic field observation, and its performance directly determines the accuracy of magnetic field measurement. Among them, the optically pumped magnetometer began to be developed in the 1960s. It is an instrument that measures the magnetic field strength based on the interaction between the magnetic field and atoms, combined with the means of optical pumping and optical magnetic resonance. It has significant advantages such as high sensitivity, small size, and scalar measurement (not affected by attitude changes).

[0003] Optically pumped atomic magnetometers mainly include alkali metal atomic magnetometers and noble gas atomic magnetometers (the common one is the helium optically pumped magnetometer). Since the helium nucleus has zero spin and there is no nonlinear Zeeman effect, the helium optically pumped atomic magnetometer has a small heading error and is suitable for a large magnetic field range. However, the energy of helium metastable atoms is relatively high, which is easy to excite other atoms or molecules. It is impossible to solve the wall collision relaxation by filling buffer gas or coating the inner wall of the chamber, which restricts the improvement of sensitivity and the size of the atomic gas chamber. The alkali metal atomic magnetometer is based on alkali metal vapor as the atomic gas. Potassium, rubidium, and cesium atoms are the most commonly used atomic sources in this technology. The wall collision relaxation time can be extended by filling buffer gas or coating an anti-relaxation film on the inner surface of the wall, which is beneficial to the improvement of sensitivity and the reduction of the size of the atomic gas chamber.

[0004] At present, China has been able to achieve independent control in the research and development of lamp-pumped alkali metal atomic magnetometers, and the performance indicators of the magnetometers are comparable to those of foreign similar products. However, in the aspect of laser-pumped alkali metal atomic magnetometers, at present, due to the limited level of independent control of laser light sources and the lack of magnetic compensation interference technology, the measurement accuracy of laser-pumped magnetometers is not high and the stability is poor. Summary of the Invention

[0005] The purpose of the present application is to provide a packaging structure of a magnetometer and a magnetometer, so as to solve the problems in the prior art that due to the limited level of independent control of laser light sources and the lack of magnetic compensation interference technology, the measurement accuracy of laser-pumped magnetometers is not high and the stability is poor.

[0006] Based on this, in the first aspect, the present application provides a packaging structure for a magnetometer, including: a pump light part, including a collimating sleeve, in which a laser generating device and a collimating lens are arranged; a magnetic field detection part, including a delay wave plate chamber, an atomic gas chamber, and a photosensitive device chamber. The two ends of the atomic gas chamber are respectively connected to the delay wave plate chamber and the photosensitive device chamber. The collimating sleeve, the delay wave plate chamber, the atomic gas chamber, and the photosensitive device chamber are internally connected. Wherein, a wave plate is arranged in the delay wave plate chamber, and a photodiode is arranged in the photosensitive device chamber; a plug-in part is arranged at one end of the delay wave plate chamber far from the atomic gas chamber, and the pump light part and the magnetic field detection part are detachably connected through the plug-in part.

[0007] In a possible implementation manner, at least one plug-in hole is arranged on the collimating sleeve, the plug-in hole is matched with the plug-in part, and the plug-in part is arranged in the plug-in hole.

[0008] In a possible implementation manner, the collimating sleeve is a hollow cavity with a cube or cuboid-shaped outer surface. Wherein, a first opening is arranged on the surface of the collimating sleeve close to the magnetic field detection part, and the first opening is used for passing light; second openings are arranged on two adjacent surfaces of the first opening, and the two adjacent surfaces are parallel, and the second openings are used for wire routing.

[0009] In a possible implementation manner, a laser tube is arranged on the surface opposite to the first opening, and the laser tube is configured as a laser source.

[0010] In a possible implementation manner, the side walls of the delay wave plate chamber all have openings.

[0011] In a possible implementation manner, a 1 / 4 wave plate is arranged in the delay wave plate chamber for changing the phase of light waves.

[0012] In a possible implementation manner, magnetic field coils are respectively arranged at both ends of the atomic gas chamber, and the magnetic field coils are arranged around the inner surface of the atomic gas chamber; cesium atomic gas is filled in the atomic gas chamber, and the cesium atomic gas is used to interact with light to obtain a spectral signal.

[0013] In a possible implementation manner, the photodiode in the photosensitive device chamber is arranged at the end of the photosensitive device chamber.

[0014] In a possible implementation manner, the internal channel shapes of the collimating sleeve, the delay wave plate chamber, the atomic gas chamber, and the photosensitive device chamber are the same.

[0015] In the second aspect, the present application provides a magnetometer, including multi-strand twisted pairs, and the packaging structure as described above. The multi-strand twisted pairs are respectively connected to the laser generating device and the photodiode.

[0016] The beneficial effects of the packaging structure of a magnetometer provided by this application are at least as follows: The packaging structure of the laser-pumped magnetometer is divided into two parts, namely the pump light part and the magnetic field detection part. The pump light part includes a collimating sleeve, and a laser generating device and a collimating lens are arranged inside the collimating sleeve; the magnetic field detection part includes a retarder chamber, an atomic gas chamber, and a photosensitive device chamber. The two ends of the atomic gas chamber are respectively connected to the retarder chamber and the photosensitive device chamber. The collimating sleeve, the retarder chamber, the atomic gas chamber, and the photosensitive device chamber are internally connected. Among them, a wave plate is arranged in the retarder chamber, and a photodiode is arranged in the photosensitive device chamber; a connector is arranged at one end of the retarder chamber far from the atomic gas chamber, and the pump light part and the magnetic field detection part are detachably connected through the connector. This solves the problems in the prior art that the independent controllability level of the laser light source is limited and the magnetic compensation interference technology is insufficient, resulting in low measurement accuracy and poor stability of the laser-pumped magnetometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 Schematic diagram of the packaging structure of the magnetometer provided by an embodiment of this application;

[0019] Figure 2 Schematic diagram of the measurement principle of the magnetometer provided by an embodiment of this application;

[0020] Figure 3 Internal optical path schematic diagram of the laser-pumped magnetometer provided by an embodiment of this application;

[0021] Among them, the reference numerals in the figure are as follows:

[0022] 101, collimating sleeve; 102, connector; 103, retarder chamber; 104, atomic gas chamber; 105, photosensitive device chamber; 106, second opening; 107, first opening. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following further details this application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0024] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The orientations or positions indicated by the terms "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positions shown in the drawings, and are for convenience of description only, and should not be construed as a limitation to the technical solution of the present invention. The terms "first" and "second" are only for convenience of description, and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. The meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0025] Magnetic field measurement has always been an important research direction in the field of precision instrument measurement. Since the invention of the compass in ancient China, measurement devices based on various working principles have been gradually developed, such as fluxgate, Hall sensor, superconducting quantum magnetometer, spin-exchange relaxation-free magnetometer, etc. Among them, the optically pumped magnetometer began to develop in the 1960s. It is an instrument that measures the magnetic field strength by combining the means of optical pumping and optical magnetic resonance on the basis of the interaction between the magnetic field and atoms. It has significant advantages such as high sensitivity, small volume, and scalar measurement (not affected by attitude changes).

[0026] Optically pumped atomic magnetometers mainly include alkali metal atomic magnetometers and inert gas atomic magnetometers (the common one is the helium optically pumped magnetometer). Since the helium nucleus has zero spin and there is no nonlinear Zeeman effect in the helium optically pumped atomic magnetometer, the course error is small, and it is applicable to a large magnetic field range. However, the energy of helium metastable atoms is relatively high, which is easy to excite other atoms or molecules. It is impossible to solve the wall collision relaxation by filling buffer gas or coating the inner wall of the chamber, which restricts the improvement of sensitivity and the size of the atomic gas chamber. The alkali metal atomic magnetometer is based on alkali metal vapor as the atomic gas. Potassium, rubidium, and cesium atoms are the most commonly used atomic sources in this technology. The wall collision relaxation time can be extended by filling buffer gas or coating an anti-relaxation film on the inner surface of the wall, which is beneficial to the improvement of sensitivity and the reduction of the size of the atomic gas chamber.

[0027] China's equipment for magnetic field gradient test and calibration mainly relies on imports from countries in the Five Eyes Alliance such as Canada and the UK. For example, the Cs-3 cesium optically pumped magnetometer of Scintrex Company in Canada. However, its high-performance version is embargoed against China. When its magnetometer is exported to China, the sensitivity is artificially reduced by one order of magnitude. As the competition between China and the US becomes increasingly fierce, these countries may impose an embargo on these sensitive devices at any time. However, China does not master some of the core technologies of these devices and is easily restricted by others.

[0028] At present, in the field of laser-pumped alkali metal atomic magnetometers, due to the limited independent controllability level of laser light sources and the insufficient magnetic compensation interference technology, the measurement accuracy of laser-pumped magnetometers is not high and the stability is poor.

[0029] Therefore, the present application provides a packaging structure of a magnetometer, including: a pump light part and a magnetic field detection part. Among them, the pump light part includes a collimating sleeve 101, and a laser generating device and a collimating lens are arranged inside the collimating sleeve 101. The magnetic field detection part includes a retarder chamber 103, an atomic gas chamber 104 and a photosensitive device chamber 105. The two ends of the atomic gas chamber 104 are respectively connected to the retarder chamber 103 and the photosensitive device chamber 105. The collimating sleeve 101, the retarder chamber 103, the atomic gas chamber 104 and the photosensitive device chamber 105 are internally connected. Among them, a wave plate is arranged in the retarder chamber 103, and a photodiode is arranged in the photosensitive device chamber 105. A connector 102 is arranged at one end of the retarder chamber 103 away from the atomic gas chamber 104, and the pump light part and the magnetic field detection part are detachably connected through the connector.

[0030] The basic principle of a laser-pumped magnetometer is to utilize the Larmor precession of atomic magnetic moments under the action of an external magnetic field, that is, the motion of the magnetic moments of electrons, atomic nuclei and atoms under the action of an external magnetic field. It is an instrument that measures the magnetic field by measuring the precession frequency.

[0031] Its basic working process can be summarized as follows: The atomic cloud in the alkali metal gas chamber undergoes Zeeman splitting under the action of an external magnetic field. A pump light beam with a specific frequency is injected into the gas chamber. At this time, the atoms in the gas chamber are pumped from the ground state Zeeman sub-level to the excited state under the action of the pump light. The atoms in the excited state decay to the sub-levels through spontaneous emission. After the atoms on the sub-levels are polarized, a macroscopic magnetic moment will be formed, and the atomic spin will have a projection in the polarization direction, that is, the direction perpendicular to the magnetic field. We add a probe laser in the direction perpendicular to the pump light. The projection of the spin-polarized alkali metal atoms in the direction of the probe light will have different degrees of dispersion effects with the probe light, and thus a polarization angle will appear. This polarization angle is collected by a detection circuit and then sent to the circuit for processing. Through the Bloch equation, the magnitude of this polarization angle can be calculated, and then the angular frequency of the Larmor precession can be calculated, and further the magnitude of the external magnetic field can be calculated.

[0032] During the measurement process of the magnetometer, magnetic interference has a great influence on the measurement results of the magnetometer. To meet the design requirements, the packaging structure of the magnetometer needs to be non-magnetic, have low line impedance, high resistivity of the insulating layer, high temperature resistance, and certain structural strength.

[0033] In this embodiment, the packaging structure of the magnetometer is divided into two parts, the pump light part and the magnetic field detection part. The pump light part packages the laser generating device and the collimating lens, and a collimating sleeve 101 is arranged outside. An opening is provided on the wall of the collimating sleeve 101, which is used for wiring on the one hand and ensures a certain structural strength on the other hand. The magnetic field detection part includes a delay wave plate chamber 103, an atomic gas chamber 104, and a photosensitive device chamber 105. The setting sequence is the delay wave plate chamber 103, the atomic gas chamber 104, and the photosensitive device chamber 105 in turn, that is, the delay wave plate chamber 103 and the photosensitive device chamber 105 are respectively connected to both ends of the atomic gas chamber 104. Among them, the delay wave plate chamber 103 is connected to the collimating sleeve 101.

[0034] It should be noted that the laser generating device can be a VCSEL laser tube. The inside of the packaging structure is interconnected. A wave plate is provided in the delay wave plate chamber 103, and cesium atomic gas can be filled in the atomic gas chamber 104. The cesium atomic gas is used to interact with light to obtain a narrow-bandwidth spectral signal to meet the reception of the photosensitive device. A photodiode can be arranged in the photosensitive device chamber 105 for receiving the spectral signal.

[0035] The traditional atomic magnetometer adopts a dual-beam scheme, and obtains the external magnetic field value by measuring the rotation angle of the polarization plane of the detection light. There are three common modes in this scheme, namely the pump light non-modulation mode, the pump light sine modulation mode, and the pump light square wave modulation mode. Compared with the prior art, the single-beam magnetic field modulation method only requires one pump light, and the system structure is compact, which can significantly reduce the volume and system complexity.

[0036] In one embodiment, at least one socket hole is provided on the collimating sleeve 101, and the socket hole matches the socket part 102, and the socket part 102 is arranged in the socket hole.

[0037] Specifically, in this embodiment, the pump light part and the magnetic field detection part can be set in a detachable connection manner. At least one socket hole is provided on the collimating sleeve 101 of the pump light part, and the socket hole matches the socket part 102. The pump light part can be detachably connected to the magnetic field detection part through the socket part 102. In one example, at least one socket hole is also provided on the delay wave plate chamber 103, and the socket hole matches the socket part 102. The collimating sleeve 101 of the pump light part and the delay wave plate chamber 103 of the magnetic field detection part are detachably connected through the socket part 102.

[0038] In one embodiment, the socket part 102 can also be fixedly arranged on the surface of the delay wave plate chamber 103, and the collimating sleeve 101 of the pump light part and the delay wave plate chamber 103 of the magnetic field detection part are detachably connected through the socket part 102.

[0039] In one embodiment, the collimating sleeve 101 is a hollow cavity with a cube or cuboid-shaped outer surface. Among them, a first opening 107 is provided on the surface of the collimating sleeve 101 close to the magnetic field detection part, and the first opening is used for light to pass through. Second openings 106 are provided on two adjacent faces of the first opening 107, and the two adjacent faces are parallel. The second openings 106 are used for wire routing.

[0040] Specifically, in this embodiment, the collimating sleeve 101 is configured as a cube or cuboid with a hollow interior. A first opening 107 is provided on the surface of the collimating sleeve 101 close to the magnetic field detection part, and the first opening is used for light to pass through. Second openings 106 are provided on two adjacent faces of the first opening 107, and the two adjacent faces are parallel. The second openings 106 are used for wire routing. It can be understood that the first opening 107 is used to connect the magnetic field detection part, and the second openings 106 are used for wiring. Under the condition of meeting the structural strength, the second openings 106 also have the function of reducing the weight of the collimating sleeve 101.

[0041] In one embodiment, a laser tube is provided on the face opposite to the first opening 107, and the laser tube is configured as a laser source.

[0042] Specifically, in this embodiment, a laser tube can be provided at the end of the collimating sleeve 101 for emitting laser light. The end of the collimating sleeve 101 is opposite to the first opening 107, so that the emitted laser light can enter the magnetic field detection part through the first opening 107 without being blocked.

[0043] Before the laser enters the magnetic field detection part, the laser emitted by the laser tube is refracted by a collimating lens and then enters the magnetic field detection part.

[0044] In one embodiment, the side walls of the delay wave plate chamber 103 all have openings. A 1 / 4 wave plate is provided in the delay wave plate chamber 103 for changing the phase of the light wave.

[0045] Specifically, in this embodiment, a 1 / 4 wave plate is used to change the phase of the light wave. The 1 / 4 wave plate can be set at the middle position of the delay wave plate or can be set as needed. The 1 / 4 wave plate is also called a quarter wave plate or a delay wave plate. It is a special type of wave plate that can cause a phase difference of 90 degrees (π / 2 radians) for the light wave passing through it. This wave plate is particularly suitable for generating linearly polarized light and circularly polarized light. The working principle of the 1 / 4 wave plate is based on the polarization state of the light wave and the birefringence characteristics of the wave plate material. When linearly polarized light passes through the 1 / 4 wave plate, the two orthogonal polarization components of the light wave (usually horizontal and vertical polarizations) will propagate at slightly different speeds in the wave plate. This speed difference results in a phase difference between the two polarization components, and the design of the 1 / 4 wave plate makes the generated phase difference exactly 90 degrees to meet the measurement requirements.

[0046] In one embodiment, magnetic field coils are respectively arranged at both ends of the atomic gas cell 104, and the magnetic field coils are arranged to surround the inner surface of the atomic gas cell 104. The atomic gas cell 104 is filled with cesium atomic gas, and the cesium atomic gas is used to interact with light to obtain a spectral signal.

[0047] Cesium atoms are an important atomic system and are widely used in the fields of precision measurement and quantum technology. The two main isotopes of cesium atoms are 133Cs and 135Cs, and 133Cs is often used in the research of atomic clocks and the Doppler effect due to its good characteristics. The cesium atomic gas cell 104 is a core component for realizing many quantum effects and precision measurement technologies. The cesium atomic gas cell 104 is an important experimental device in the fields of quantum optics and precision measurement, and it is usually used to realize the preparation, manipulation, and detection of atomic states. The cesium atoms in the cesium atomic gas cell 104 can be used for highly sensitive spectral measurement. For example, in the coherent population oscillation (CPO) spectroscopy technique, by the interaction of specific lasers with atoms, a spectral signal with a narrow linewidth can be achieved, which can improve the accuracy of spectral measurement.

[0048] In one embodiment, the photodiode in the photosensitive device chamber 105 is arranged at the end of the photosensitive device chamber 105.

[0049] Specifically, in this embodiment, cesium atoms are selected as the working gas of the magnetometer, and the light source of the probe uses a VCSEL laser tube. The emitted linearly polarized light has a wavelength of 89 nm. After passing through the collimating lens, it is made into circularly polarized light by a quarter-wave plate, and then resonates with the cesium atoms in the atomic gas cell 104 and is finally received by a photodiode (PD).

[0050] In a more specific embodiment, the internal channel shapes of the collimating sleeve 101, the delay wave plate chamber 103, the atomic gas cell 104, and the photosensitive device chamber 105 are the same.

[0051] In this embodiment, setting the internal channel shapes of the collimating sleeve 101, the delay wave plate chamber 103, the atomic gas cell 104, and the photosensitive device chamber 105 to be the same is more conducive to the propagation of light and is not easily blocked by other contours.

[0052] The working principle of the magnetometer provided by this application includes the following processes:

[0053] Laser pumping: Laser pumping uses a laser to emit a specific polarized light that resonates with atomic energy level transitions. Under the action of light, the spins of atoms obtain the angular momentum corresponding to the light polarization and change from a disordered arrangement in the thermal equilibrium state to an orderly arrangement form. Since there is a corresponding relationship between the atomic magnetic moment and the atomic angular momentum, this results in the same orientation of the atomic magnetic moments, thereby generating a macroscopic magnetic moment.

[0054] Precession of the atomic magnetic moment in an external magnetic field: When the atomic magnetic moment is in a magnetic field with a magnetic induction intensity of B, if the magnetic moment μ of this atomic nucleus is not in the same direction as B, under the action of the magnetic field, the atomic nucleus will be subjected to a torque T perpendicular to the plane formed by μ and B. Under the action of the torque T, the direction of the atomic magnetic moment will change continuously, but the magnitude remains unchanged, and the spinning nucleus will undergo precession like a top under the action of gravity.

[0055] Detection of atomic magnetic moment precession: When the atomic magnetic moment undergoes precession, the quantum state of the atom also changes rapidly. Since the absorption and dispersion characteristics of different quantum states for laser light are different, the light intensity of the light beam passing through the atomic gas changes corresponding to the precession frequency.

[0056] Realization of a self-excited magnetometer: Using the strong change signal corresponding to the precession frequency in the detection light, through phase matching, signal amplification, and feedback to the magnetic field coil surrounding the atomic gas cell 104 to form positive feedback. When the frequency of the RF signal in the coil resonates with the precession frequency, the detection light intensity can generate the strongest detection signal, so the self-excited oscillation formed by positive feedback will stabilize at the atomic precession frequency. Since the precession frequency is proportional to the magnitude of the magnetic field to be measured, the magnitude of the magnetic field can be measured by measuring the frequency of the self-excited oscillation.

[0057] As Figure 2 shown, the overall structure of the laser-pumped magnetometer consists of a light source module, a magnetic sensing module, and a signal detection module. According to its operating principle, the Mx type self-excited magnetometer structure design is adopted, and this magnetometer conducts high-precision magnetic measurement based on the quantum magnetic effect of cesium atoms.

[0058] The light beam emitted by the laser tube is collimated by a converging lens to obtain parallel optical pumping light, which is converted into circularly polarized light by a quarter-wave plate. Under the action of the polarized light, the atoms in the micro-atomic gas cell 104 are polarized. The RF coil (i.e., the electromagnetic coil) generates an RF magnetic field. When the frequency of this RF field resonates with the external magnetic field to be measured, the polarized component of the atoms enables the photodiode to receive a signal with the same frequency as the driving field, which is fed back to the coil through an amplifier. When the feedback loop meets certain loop gain and phase conditions, the system undergoes self-excited oscillation, and measuring the frequency of the self-excited oscillation can realize the measurement of the magnitude of the external magnetic field.

[0059] Figure 3 It is a schematic diagram of the internal optical path of the laser-pumped magnetometer. The laser is introduced through a polarization-maintaining fiber and collimated by a collimating lens. After the optical path direction is changed by 90° through a folding prism, the linearly polarized light is converted into circularly polarized light by a quarter-wave plate and incident on the atomic gas cell 104 for detecting the magnetic field. After the laser interacts with the alkali metal atoms in the presence of a magnetic field, the transmitted light is converted into a voltage signal by a photodetector and then output.

[0060] In addition, the present application also provides a magnetometer, which includes a multi-strand twisted pair wire and the above-mentioned encapsulation structure, and the multi-strand twisted pair wires are respectively connected to the laser generating device and the photodiode.

[0061] A magnetic shielding wire is a special cable designed to reduce the impact of magnetic field interference on sensitive devices or signal transmission. Magnetic shielding wires usually use high-permeability materials such as permalloy, μ-metal, nickel steel, and cold-rolled steel to achieve effective shielding of magnetic fields. These materials can, through the action of magnetic flux shunting, concentrate the surrounding magnetic field lines into the shielding material, thereby greatly weakening the magnetic field inside the shield and protecting sensitive devices.

[0062] A twisted pair wire is a type of magnetic shielding wire composed of two insulated copper wires that are twisted together at a certain pitch. The twisted design of the twisted pair wire helps reduce electromagnetic interference and improve the electromagnetic compatibility of the cable.

[0063] The encapsulation structure of a magnetometer provided by the present application is divided into two parts: a pump light part and a magnetic field detection part. The pump light part includes a collimating sleeve 101, and a laser generating device and a collimating lens are arranged inside the collimating sleeve 101; the magnetic field detection part includes a delay wave plate chamber 103, an atomic gas chamber 104, and a photosensitive device chamber 105. The two ends of the atomic gas chamber 104 are respectively connected to the delay wave plate chamber 103 and the photosensitive device chamber 105. The collimating sleeve 101, the delay wave plate chamber 103, the atomic gas chamber 104, and the photosensitive device chamber 105 are internally connected. Among them, a wave plate is arranged in the delay wave plate chamber 103, and a photodiode is arranged in the photosensitive device chamber 105; a plug-in connector 102 is arranged at one end of the delay wave plate chamber 103 far from the atomic gas chamber 104, and the pump light part and the magnetic field detection part are detachably connected through the plug-in connector. The encapsulation structure provided by the present application can improve the sensitivity and bandwidth of the absolute scalar magnetometer, reduce the weight and volume of the absolute scalar magnetometer, all wiring uses a twisted pair form, and magnetic shielding wires are used for connection, solving the problems in the prior art that the independent controllability level of the laser light source is limited and the magnetic compensation interference technology is insufficient, resulting in low measurement accuracy and poor stability of the laser-pumped magnetometer.

[0064] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A packaging structure of a magnetometer, characterized in that: include: The pump light part includes a collimating sleeve, in which a laser generating device and a collimating lens are arranged, and an opening for wiring is opened on the wall of the collimating sleeve; A magnetic field detection unit, comprising a delay wave plate chamber, an atomic gas chamber and a photosensitive device chamber, wherein two ends of the atomic gas chamber are respectively connected to the delay wave plate chamber and the photosensitive device chamber, and the collimation sleeve, the delay wave plate chamber, the atomic gas chamber and the photosensitive device chamber are internally connected, wherein a quarter wave plate for changing the phase of a light wave is arranged in the delay wave plate chamber, magnetic field coils are respectively arranged at two ends of the atomic gas chamber, and the magnetic field coils are arranged around the inner surface of the atomic gas chamber, the atomic gas chamber is filled with cesium atomic gas for reacting with light to obtain a spectral signal, and a photodiode is arranged in the photosensitive device chamber; A connector is provided at one end of the delay wave plate chamber away from the atomic gas chamber, and the pump light unit and the magnetic field detection unit are detachably connected through the connector; The collimating sleeve, the delay wave plate chamber, the atomic gas chamber and the internal channels of the photosensitive device chamber have the same shape.

2. The packaging structure according to claim 1, characterized in that: At least one plugging hole is arranged on the alignment sleeve, the plugging hole matches the plugging component, and the plugging component is arranged in the plugging hole.

3. The packaging structure according to claim 1, characterized in that: The collimation sleeve is a hollow cavity with an outer surface in the shape of a cube or a cuboid, wherein a first opening is provided on a surface of the collimation sleeve close to the magnetic field detection unit, and the first opening is used for passing light; A second opening is provided on two surfaces adjacent to the first opening, the two adjacent surfaces are parallel, and the second opening is used for wiring.

4. The packaging structure according to claim 3, characterized in that: A laser tube is arranged on a surface opposite to the first opening, and the laser tube is configured as a laser source.

5. The packaging structure according to claim 1, characterized in that: The side walls of the retardation wave plate chamber each have an opening.

6. The packaging structure according to claim 1, characterized in that: The photodiode in the photosensitive device chamber is arranged at the end of the photosensitive device chamber.

7. A magnetometer, characterized in that: It comprises a plurality of twisted-pair wires and a packaging structure as described in any one of claims 1 to 6, wherein the plurality of twisted-pair wires are respectively connected to a laser generating device and a photodiode.

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