A compact spin-exchange relaxation free bi-axial inertial measurement structure

Abstract

A compact spin-exchange relaxation free biaxial inertial measurement structure, by locating the air chamber in the oven, the oven is positioned in the coil support cylinder, the coil support cylinder is positioned in the magnetic field shielding cylinder, can avoid the suspended installation, positioning is more reliable, is favorable for reducing the influence of external vibration and other interference, thereby improves the stability, reliability of the device, its characterized in that, including the magnetic field assembly installed on the main structure, the magnetic field shielding cylinder of magnetic field assembly is provided with coil support cylinder, the bottom of the cylinder nest groove of coil support cylinder is nested one end of oven, the other end of oven is nested by the bottom nest groove of oven support cylinder, the outer edge of the cylinder mouth of oven support cylinder is nested by the inner edge of the cylinder mouth of coil support cylinder, the oven is provided with clamping device used as air chamber installation reference.

Description

Technical Field

[0001] This invention relates to the field of compact inertial measurement structure technology, and in particular to a compact dual-axis inertial measurement structure without spin exchange relaxation. The modular sub-components are assembled through interfaces, which facilitates replacement and maintenance, and makes reference transmission more reliable. It also improves the scalability and integration of different design schemes, and facilitates scientific research and long-term inertial navigation of vehicles. Background Technology

[0002] With the continuous development of atomic manipulation technology, new types of atomic sensors have emerged in the fields of scientific instruments and inertial measurement. These sensors are based on manipulating cold and hot atoms to sensitively detect relevant field information and possess functions such as cutting-edge scientific exploration and inertial information measurement. Among them, inertial measurement devices that utilize light, magnetic, and thermal fields to put hot atoms in a spin-exchange relaxation-free (SERF) state have received significant attention both domestically and internationally and have been developed into one of the means of high-sensitivity inertial measurement.

[0003] The aforementioned devices rely on lasers to extract atomic information; therefore, early structures were generally built on optical platforms. Subsequent horizontal and vertical device layouts largely followed these early designs, including an optical structure consisting of an adjustable frame housing optical elements, a magnetic field structure composed of a magnetic shielding cylinder and magnetic field manipulation coils, and a thermal control structure using hot airflow or heat-generating coils for heating and an oven for heat preservation. Furthermore, to achieve higher precision and stability, a vacuum system can be used to encase the sensitive sensor to reduce air wave interference; a water-cooling system can be used to isolate the internal high temperature to reduce noise from the magnetic shielding material; a demagnetizing system can be used to reduce the remanence and gradient of the magnetic material to minimize the influence of remanence; and a vibration isolation system can be used to support the device and attenuate environmental vibration noise.

[0004] The design of compact inertial measurement structures requires minimizing the size of components while ensuring operability, while meeting high-precision measurement requirements. Generally, after beam shaping, collimation, and beam expansion of the laser emitted from a laser, it needs to pass through components such as glass slides, lenses, and prisms to obtain laser light with a certain power density, polarization state, and azimuth angle to meet the needs of manipulating atoms and extracting atomic information. However, optical components are installed in a confined space, often requiring significant time for alignment and adjustment, and are inconvenient to replace. Furthermore, to meet the requirements of high shielding coefficient and low material noise, the shielding cylinder needs to be a combined magnetic shielding system of 2 to 5 layers, often using a shaft-hole fit supplemented by supporting rings for layer-by-layer installation, resulting in low fitting accuracy and complex assembly / disassembly. Generally, the wires used for sensing and control connect the external electronic control system of the sensitive meter to the internal sensors and actuators, often using a design that passes through the center of the magnetic shielding cylinder cover. Therefore, during instrument assembly and debugging, it is necessary to repeatedly cut and connect wires to disassemble internal components, resulting in complex and time-consuming operations, and the solder at the connection points may introduce interfering magnetic fields. The gas chamber, which holds the atoms, is the core component sensitive to inertial information. It is often mounted on the main structure wall using a cantilever beam structure. While this method is simple, it leaves the gas chamber suspended, making it susceptible to interference and vibration, thus affecting the stability of the device. Furthermore, verifying the inertial sensitivity of the device in two orthogonal directions requires two perpendicular laser beams to extract the corresponding inertial information, and a pumping atomic laser perpendicular to both beams as the basis for measurement. Therefore, the problem of precise alignment of the three beams under size constraints urgently needs to be solved. Simultaneously, considering the device fixation problem in dual-axis mode, two flat mating surfaces need to be designed on the meter head to ensure test stability. In summary, the current compact spin-exchange relaxation-free dual-axis inertial measurement unit requires structural design optimization. The existing structure is complex to assemble and difficult to disassemble, affecting its experimental efficiency as a research platform and hindering further accuracy improvements and future engineering requirements. Summary of the Invention

[0005] The problems solved by this invention are: overcoming the shortcomings of existing compact, spin-exchange-relaxation-free dual-axis inertial measurement structures; utilizing a modular, component-based design to reduce the volume of each part and facilitate replacement, while being compatible with various optical, magnetic, and thermal field design schemes; optical components based on modular optical base plates can be independently adjusted and installed as a whole, shortening the optical path adjustment time; magnetic field components based on an integrated multi-layer magnetic shielding cylinder ensure the assembly accuracy of the shaft-hole fit, while radial slotting simplifies the disassembly and assembly process; through reasonable design of the installation reference, the atomic gas cell is tightly clamped and fixed, making reference transmission more reliable; through reasonable allocation of assembly accuracy and setting of a fine-tuning lens frame, the orthogonal alignment between beams is ensured; and through the configuration of a communication interface and the use of countersunk fasteners, the flatness of the device surface is guaranteed.

[0006] The technical solution of the present invention is as follows:

[0007] A compact, spin-free, exchange-relaxation-free biaxial inertial measurement structure is characterized by comprising a magnetic field assembly mounted on a main structure. A coil support cylinder is disposed within the magnetic field shielding cylinder of the magnetic field assembly. One end of an oven is fitted with a nested groove at the bottom of the coil support cylinder, and the other end of the oven is fitted with a nested groove at the bottom of the oven support cylinder. The outer edge of the oven support cylinder's opening is fitted with the inner edge of the coil support cylinder's opening. A clamping device serving as a reference for gas chamber installation is disposed within the oven.

[0008] The main structure has several optical base plates distributed on it, and optical components are installed on each optical base plate. The optical components are used to manipulate the pump light and detection light, which are formed to be orthogonal, to irradiate and pass through the gas chamber respectively.

[0009] The oven is equipped with a temperature control component, which includes a combination of a heat-generating coil, a temperature-sensing resistor, and a temperature control circuit. The temperature control component is used to uniformly raise and maintain the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the sensitivity of atoms to inertial information, and improving the signal-to-noise ratio.

[0010] The magnetic field shielding cylinder adopts an integrated multi-layer magnetic shielding cylinder structure.

[0011] The magnetic field assembly includes an external demagnetizing fixture, an internal demagnetizing fixture, and an inter-cylinder fixture. The magnetic field assembly is used to provide a weak magnetic field environment and a magnetic field excitation signal, thereby reducing the sensitivity of atoms to external interference magnetic fields, improving the coherence of atomic spins, and achieving the purpose of manipulating the atomic ensemble with a magnetic field.

[0012] The main structure is provided with a shielding cover, the top surface of the shielding cover is provided with a cover handle, the side of the shielding cover is provided with a wiring plate, and the bottom surface of the main structure is provided with a bottom angle iron.

[0013] A magnetic field manipulation coil is installed on the coil support cylinder to generate an internal magnetic field.

[0014] An optical assembly is installed on the main structure. The optical assembly consists of a laser, optical components and a supporting base plate. The optical assembly is positioned and fixed to the main structure through mating surfaces, alignment holes and screws. The optical assembly is used to provide three laser beams that meet the requirements of power, polarization degree and incident angle, thereby extracting the rotation information in two orthogonal directions sensed by the atoms.

[0015] The clamping device includes a fixing block at one end and a pressing block at the other end located in the inner cavity of the oven. An air chamber is formed between the fixing block and the pressing block. The surface of the fixing block in the air chamber is the installation positioning reference of the air chamber. A sliding guide rail for the pressing block is provided on the inner wall of the oven so that the pressing block presses the air chamber along the sliding guide rail.

[0016] The technical effects of this invention are as follows: This invention provides a compact, spin-exchange-relaxation-free biaxial inertial measurement structure, mainly composed of an optical component, a magnetic field component, and a temperature control component. The optical component provides three laser beams that meet the requirements for power, polarization degree, and incident angle, thereby extracting rotational information sensed by atoms in two orthogonal directions. The magnetic field component provides a weak magnetic field environment and magnetic field excitation signal, thereby reducing the sensitivity of atoms to external interfering magnetic fields, improving the coherence of atomic spins, and achieving the purpose of magnetic field manipulation of the atomic ensemble. The temperature control component uniformly raises and maintains the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the sensitivity of atoms to inertial information, and improving the signal-to-noise ratio. This invention realizes a biaxial inertial measurement structure under volume constraints, compatible with various optical field, magnetic field, and thermal field design schemes. Through optimized structural design, the device's optical path is easy to adjust, the structure is convenient to assemble and disassemble, the installation reference is reliable, and the experimental safety is strong, improving the experimental efficiency of scientific research and facilitating long-term inertial navigation exploration of carriers.

[0017] The advantages of this invention compared to the prior art are as follows:

[0018] (1) The optical components of this invention adopt a modular optical base plate, which can be integrated to mount optical components. Adjustments such as axis alignment and laser optical axis alignment of optical elements can be performed independently outside the device, and then the entire assembly is installed inside the device. This ensures reliable fit, simple operation, and strong adjustability. For different pumping and detection optical path schemes, it is often necessary to combine and build different optical devices, which is time-consuming and has poor repeatability. However, this invention allows for direct replacement of the corresponding modular optical path components, saving experimental time. Furthermore, once an optical path is aligned, no further adjustments are needed, ensuring the repeatability of the experimental scheme and accelerating experimental efficiency. In addition, connecting the modular base plate to the main structure requires only a small number of mounting holes. Compared to directly fixing the optical devices to the main structure, this greatly reduces the number of connecting threaded holes and mounting slots, improves the thermal stability of the structure, reduces stress concentration, and enhances structural reliability.

[0019] (2) The magnetic field assembly of the present invention adopts an integrated multi-layer magnetic shielding cylinder, which is formed by bonding the multi-layer cylinder with epoxy resin and aluminum nitride ceramic powder. This design not only simplifies the multi-layer cylinder assembly process required for replacing the sensitive gas chamber and ensures the coaxiality of the multiple shaft holes, but also improves the thermal conductivity between the cylinders, thereby reducing the temperature of the shielding layer and suppressing the noise of the magnetic material. In addition, grinding the inner surface of the inner cylinder or its mating tooling improves the fitting accuracy between the magnetic shielding cylinder and the coil support cylinder, which is beneficial to ensuring optical-magnetic alignment.

[0020] (3) The cylindrical magnetic shielding cylinder of the present invention has a length-to-diameter ratio greater than one, and its axial magnetic shielding factor is greater than that of the radial direction. At the same time, choosing to open the wiring groove on the radial side of the cylinder cover is more conducive to ensuring the shielding effect against the external magnetic field than the scheme of opening the wiring hole in the axial center; and when opening the cover, it is not necessary to cut the wire, which can reduce the influence of residual magnetism introduced by solder, optimize the installation process, and improve experimental efficiency.

[0021] (4) The magnetic shielding cylinder of the present invention is equipped with a demagnetizing fixture, thereby realizing a multi-wire winding demagnetizing scheme. The fixture can limit and fix the demagnetizing wire group, so that it fits tightly against the wall of the magnetic shielding cylinder without affecting the passage of the light beam. Using this fixture to demagnetize the integrated multi-layer magnetic shielding cylinder randomizes the direction of the magnetic domains inside the magnetic material, macroscopically reduces the residual magnetism inside the cylinder, enhances the shielding effect, and improves the performance of the device.

[0022] (5) The core air chamber of the present invention is clamped to the temperature control component, and then fixed to the magnetic field component through a shaft hole, and then installed on the main structure. The core sensitive element of the device is no longer suspended, the installation and positioning are reliable, the influence of external vibration and other interference is reduced, and the stability and reliability of the device are improved.

[0023] (6) This invention uses the main structure as the design benchmark to position the optical components and magnetic field components respectively, while the temperature control component is assembled on the magnetic field component, and at the same time provides an installation benchmark for the gas chamber. According to the above benchmark transfer process, the assembly precision of each link is reasonably allocated, and the mutual alignment of the optical field, magnetic field, thermal field and atoms is ensured through high-precision structural design. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a compact, spin-free, exchange-relaxation biaxial inertial measurement structure that implements the present invention.

[0025] Figure 2 include Figure 2 (a) and Figure 2 (b) Figure 2 (a) is Figure 1 A schematic diagram of the magnetic field component in the diagram. Figure 2 (b) is Figure 2 (a) is a schematic diagram of the axial cross-sectional structure.

[0026] Figure 3 include Figure 3 (a) and Figure 3 (b) Figure 3 (a) is Figure 1 A schematic diagram of the temperature control component. Figure 3 (b) is Figure 3 (a) is a schematic diagram of the axial cross-sectional structure.

[0027] Figure 4 include Figure 4 (a) and Figure 4 (b) Figure 4 (a) is Figure 1 A schematic diagram of the main structure shell. Figure 4 (b) is Figure 4 (a) Side view structural diagram.

[0028] Figure 5 This is a schematic diagram illustrating the reference transfer of a compact, spin-free, exchange-relaxation biaxial inertial measurement structure that implements the present invention. Figure 5 The reference transfer process of the device includes, based on the main structure of the device, one way is to set a coil support cylinder at the center of the magnetic field shielding cylinder, and a gas chamber with an oven at the center of the coil support cylinder; the other way is to install optical components on each optical base plate, and manipulate the optical components to form mutually orthogonal pump light and detection light to irradiate and pass through the gas chamber respectively. Figure 5 The dashed line connecting the main structure of the device to the oven and air chamber is a prior art, and the cross on the dashed line indicates that this invention negates this prior art.

[0029] The reference numerals in the attached drawings are explained as follows: 101-Optical component, 102-Magnetic field component, 103-Temperature control component, 104-Main structure. 201-Magnetic field shielding cylinder, 202-External demagnetizing fixture, 203-Internal demagnetizing fixture, 204-Inter-cylinder fixture. 301-Coil support cylinder, 302-Oven, 303-Gas chamber, 304-Oven support cylinder. 401-Main structure, 402-Wire routing board, 403-Shielding cover, 404-Cover handle, 405-Bottom angle iron. Detailed Implementation

[0030] The following is in conjunction with the attached diagram ( Figures 1-5 The invention will be described in the following sections and examples.

[0031] Figure 1 This is a schematic diagram of a compact, spin-free, exchange-relaxation biaxial inertial measurement structure that implements the present invention. Figure 2 (a) is Figure 1 A schematic diagram of the magnetic field component in the diagram. Figure 2 (b) is Figure 2 (a) is a schematic diagram of the axial cross-sectional structure. Figure 3 (a) is Figure 1 A schematic diagram of the temperature control component. Figure 3 (b) is Figure 3 (a) is a schematic diagram of the axial cross-sectional structure. Figure 4 (a) is Figure 1 A schematic diagram of the main structure shell. Figure 4 (b) is Figure 4 (a) Side view structural diagram. Figure 5 This is a schematic diagram illustrating the reference transfer of a compact, spin-exchange-relaxation-free biaxial inertial measurement structure according to the present invention. (Reference) Figures 1 to 5As shown, a compact spin-free exchange-relaxation dual-axis inertial measurement structure includes a magnetic field assembly 102 mounted on a main structure 104 or 401. A coil support cylinder 301 is disposed inside the magnetic field shielding cylinder 201 of the magnetic field assembly 102. The bottom nesting groove of the coil support cylinder 301 covers one end of an oven 302, and the other end of the oven 302 is covered by the bottom nesting groove of an oven support cylinder 304. The outer edge of the opening of the oven support cylinder 304 is covered by the inner edge of the opening of the coil support cylinder 301. A clamping device is disposed inside the oven 302 as a mounting reference for the gas chamber 303.

[0032] The main structure 104 has several optical base plates distributed on it, and optical components are mounted on each optical base plate. The optical components are used to manipulate and form mutually orthogonal pump light and detection light to irradiate and pass through the air chamber 303 respectively. The oven 302 is provided with a temperature control component 103, which includes a combination of a heat-generating coil, a temperature measuring resistor, and a temperature control circuit. The temperature control component 103 is used to uniformly raise and maintain the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the sensitivity of atoms to inertial information, and improving the signal-to-noise ratio.

[0033] The magnetic field shielding cylinder 201 adopts an integrated multi-layer magnetic shielding cylinder structure. The magnetic field assembly 102 includes an outer demagnetizing fixture 202, an inner demagnetizing fixture 203, and an inter-cylinder fixture 204. The magnetic field assembly 102 is used to provide a weak magnetic field environment and magnetic field excitation signal, thereby reducing the sensitivity of atoms to external interference magnetic fields, improving the coherence of atomic spins, and achieving the purpose of magnetic field manipulation of atomic ensembles. A shielding cover 403 is provided on the main structure 401. A cover handle 404 is provided on the top surface of the shielding cover 403. A wiring plate 402 is provided on the side of the shielding cover 403. A bottom angle iron 405 is provided on the bottom surface of the main structure 104. A magnetic field manipulation coil is installed on the coil support cylinder 301 to generate an internal magnetic field.

[0034] An optical component 101 is mounted on the main structure 104. The optical component 101 consists of a laser, optical components and its supporting base plate. The optical component 101 is positioned and fixed to the main structure 104 through mating surfaces, alignment holes and screws. The optical component 101 is used to provide three laser beams that meet the requirements of power, polarization degree and incident angle, thereby extracting the rotation information in two orthogonal directions sensed by the atoms.

[0035] A compact, spin-exchange-relaxation-free dual-axis inertial measurement unit (IMU) structure includes optical, magnetic field, and temperature control components, mounted on the main structure of the device to manipulate atoms in the core gas chamber. The optical components provide three laser beams that meet power, polarization, and incident angle requirements, thereby extracting rotational information sensed by the atoms in two orthogonal directions. The magnetic field component provides a weak magnetic field environment and magnetic field excitation signal, reducing the atoms' sensitivity to external interfering magnetic fields, improving the coherence of atomic spins, and achieving the goal of manipulating the atomic ensemble with a magnetic field. The temperature control component uniformly raises and maintains the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the atoms' sensitivity to inertial information, and improving the signal-to-noise ratio. This invention provides a modular component design approach that facilitates disassembly and replacement, and provides more reliable reference transfer. It is compatible with multiple optical, magnetic, and thermal field design schemes, facilitating scientific research and long-term inertial navigation of transport vehicles.

[0036] refer to Figures 1 to 5 As shown, a compact spin-free exchange relaxation dual-axis inertial measurement structure includes a magnetic field component 102 with a temperature control component 103 centrally located, and optical components 101 distributed around the magnetic field component 102 and fixed on the main structure 104.

[0037] Figure 2 The illustration shows the magnetic field assembly 102 of the present invention, which includes a multi-layer cylindrical magnetic field shielding cylinder 201, an outer demagnetizing fixture 202 and an inner demagnetizing fixture 203 used together to fix the demagnetizing wire, and an inter-cylinder fixture 204 that provides interlayer support. They are connected to each other through shaft hole mating and aligned through radial openings, and then integrally formed using bonding-related processes to ensure the coaxiality of the inner and outer cylinders.

[0038] Figure 3 The illustration shows the temperature control component 103 of the present invention, including a coil support cylinder 301 for mounting a magnetic field manipulation coil, an oven 302 for providing a uniform temperature field to the core air chamber 303, and an oven support cylinder 304 for positioning. They are fixed by a shaft hole fit and a threaded connection, thereby realizing the physical limitation and magnetic field manipulation functions of the atomic ensemble.

[0039] Figure 4 The illustration shows the main structure 104 of the present invention, including a main structure 401 that provides a positioning and installation reference for other components, a cable tray 402 that connects the internal and external through-wall cables of the sensitive meter, a shielding cover 403 with a cover handle 404 to suppress external interference magnetic fields, and a bottom angle iron 405 that fixes the main structure to other mounting bases. These components are connected by countersunk screws to ensure the flatness of the device's appearance, and sealing grooves are provided at the joints to maintain internal airtightness and thermal stability.

[0040] Figure 5 This illustration demonstrates the reference transfer mechanism of the present invention. The main structure of the device serves as the design and assembly reference, while the oven and air chamber are core components that need to be connected to the installation reference. If the two were fixed together, the oven would be suspended above the main structure, resulting in a cantilever beam structure, as the air chamber must operate within the shield and coil cylinder. This not only makes the air chamber susceptible to vibration, reducing inertial measurement accuracy, but also requires additional mounting holes along the axial direction of the magnetic shielding cylinder, reducing the magnetic field shielding effect and increasing the difficulty of installation alignment. Instead, the reference of the main structure is transferred to the oven and air chamber via the magnetic field shielding cylinder and coil support cylinder, extending the transfer process to ensure reliable reference transfer at each step. Multi-layered shaft-hole fittings can be used to ensure coaxiality, solving the problem of the air chamber's sensitive source being suspended. Similarly, the optical field composed of the pump and detection beams needs to be aligned with the air chamber; otherwise, the device performance will be reduced. The beams are emitted from a laser and adjusted by optical elements, all mounted on an optical base plate, which is fixed to the main structure. Therefore, the optical field and air chamber have a unified installation reference, and their alignment accuracy depends on the specific design and assembly precision. Because the gas chamber is fixed by shielding, coil cylinders, and an oven, the alignment of light and atoms also represents the mutual alignment of the light field, magnetic field, thermal field, and atoms. Of course, the alignment accuracy differs from the principle of reference transfer. The accuracy of magnetocaloric alignment and thermogenic alignment should be at the same level, while the mechanical accuracy of photogenic alignment should be lower than that of photomagnetic alignment. In fact, the alignment of light and atoms should be given special attention, but it is difficult to guarantee by mechanical design alone. It can be achieved through optical methods, by reasonably placing mirrors in the light field to finely adjust the beam direction and complete the photogenic alignment.

[0041] A compact, spin-free, exchange-relaxation-free dual-axis inertial measurement unit (IMU) includes an optical assembly, a magnetic field assembly, and a temperature control assembly, all mounted on the main structure of the device to manipulate atoms within the core gas chamber. The optical assembly comprises a laser, optical components, and a supporting base plate, connected to the main structure via mating surfaces, alignment holes, and screws for positioning and fixation. The magnetic field assembly includes an integrated multi-layer magnetic shielding cylinder for shielding external magnetic fields, a coil for generating an internal magnetic field, and a support cylinder. The latter is installed within the former using fitting fixtures, and both are then installed as a whole into a clamping bushing within the main structure. A positioning scheme is employed, using a shielding cylinder cap for axial fixation, locating pins for radial fixation, and countersunk screws for connection and fixation. The temperature control assembly includes a heating coil, a temperature-sensing resistor, a temperature control circuit, and a heat-preserving oven. The coil provides non-magnetic heating when energized, and the temperature-sensing resistor, combined with a temperature control host computer, achieves precise temperature control. The oven surrounds the core gas chamber, providing a uniform temperature field for the atoms. This assembly is positioned in the center of the magnetic field assembly via a shaft hole and secured with threaded fasteners.

[0042] Utilizing a modular, component-based design, the volume of each part is reduced, and replacement is easy, making it compatible with various optical, magnetic, and thermal field design schemes. Optical components based on a modular optical base plate can be independently adjusted and installed as a whole, shortening optical path adjustment time. Magnetic field components based on an integrated multi-layer magnetic shielding cylinder ensure the assembly accuracy of the shaft-hole fit, while radial slotting simplifies the disassembly and assembly process. Through a rationally designed installation reference, the atomic gas cell is tightly clamped and fixed, making reference transmission more reliable. By rationally allocating assembly accuracy and setting a fine-tuning lens frame, orthogonal alignment between beams is ensured. By configuring a communication interface and using countersunk fasteners, the flatness of the device surface is guaranteed.

[0043] The magnetic field assembly is radially clamped using a clamping bushing, radially fixed using locating pins, and connected and fixed using countersunk screws. Simultaneously, a shielding cylinder cap is used for axial positioning of the magnetic field assembly, and screws are used for tightening. This combined clamping structure uses mortise and tenon joints to engage with the main structure, and incorporates an airtight design for thermal insulation and to reduce the impact of air disturbance.

[0044] The main structure is designed with sealing grooves at all joints with other components to accommodate sealing gaskets, rings, etc., increasing the airtightness and insulation of the device and reducing interference noise from airflow. The main structure has bottom positioning holes for placement on optical platforms, test turntables, or foundations, enabling various performance and stability tests. The main structure is fitted with an inner optical cover and an outer shielding cover. The former covers the optical structure, preventing optical components from being exposed to air; its inner wall has a light-shielding strip to reduce diffuse and specular reflection of the laser, minimizing interference with the optical path. The latter isolates the device from the environment and provides initial shielding against external magnetic field fluctuations, stabilizing the internal magnetic field.

[0045] The optical components provide three laser beams that meet the requirements for power, polarization degree, and incident angle, thereby extracting rotational information sensed by atoms in two orthogonal directions. The magnetic field component provides a weak magnetic field environment and magnetic field excitation signal, thereby reducing the sensitivity of atoms to external interfering magnetic fields, improving the coherence of atomic spins, and achieving the purpose of magnetic field manipulation of the atomic ensemble. The temperature control component uniformly raises and maintains the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the sensitivity of atoms to inertial information, and improving the signal-to-noise ratio. This invention realizes a dual-axis inertial measurement structure under volume constraints, compatible with various optical field, magnetic field, and thermal field design schemes. Through optimized structural design, the device's optical path is easy to adjust, the structure is easy to assemble and disassemble, the installation benchmark is reliable, and the experimental safety is strong, improving the experimental efficiency of scientific research and facilitating long-term inertial navigation exploration of carriers.

[0046] The optical components employ a modular optical base plate, allowing for integrated mounting of optical parts. Adjustments such as optical element axis alignment and laser optical axis alignment can be performed independently outside the device before the entire assembly is installed inside. This ensures reliable integration, simple operation, and high adjustability. Different pumping and detection optical path schemes often require combining and constructing different optical components, which is time-consuming and has poor repeatability. This invention allows for direct replacement of the corresponding modular optical path components, saving experimental time. Furthermore, once an optical path is aligned, no further adjustments are needed, ensuring the repeatability of the experimental scheme and accelerating experimental efficiency. In addition, connecting the modular base plate to the main structure requires only a few mounting holes. Compared to directly fixing the optical components to the main structure, this significantly reduces the number of threaded holes and mounting slots, improving the thermal stability of the structure, reducing stress concentration, and enhancing structural reliability.

[0047] The magnetic field assembly employs an integrated multi-layer magnetic shielding cylinder, which is bonded together using epoxy resin and aluminum nitride ceramic powder. This design not only simplifies the assembly process of the multi-layer cylinder required for replacing the sensitive gas chamber and ensures the coaxiality of the multiple shaft holes, but also improves the thermal conductivity between the cylinders, thereby reducing the temperature of the shielding layer and suppressing magnetic material noise. Furthermore, grinding the inner surface of the inner cylinder or its mating tooling improves the fitting accuracy between the magnetic shielding cylinder and the coil support cylinder, which is beneficial for ensuring optical-magnetic alignment.

[0048] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, and / or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A compact, spin-exchange-relaxation-free biaxial inertial measurement structure, characterized in that, The system includes a magnetic field assembly installed on the main structure. A coil support cylinder is provided inside the magnetic field shielding cylinder of the magnetic field assembly. One end of the oven is fitted with a nested groove at the bottom of the coil support cylinder. The other end of the oven is fitted with a nested groove at the bottom of the oven support cylinder. The outer edge of the opening of the oven support cylinder is fitted with the inner edge of the opening of the coil support cylinder. A clamping device is provided inside the oven as a reference for the installation of the air chamber. The main structure has several optical base plates distributed on it, and optical components are installed on each optical base plate. The optical components are used to manipulate the pump light and detection light, which are formed to be orthogonal, to irradiate and pass through the gas chamber respectively. The magnetic field shielding cylinder adopts an integrated multi-layer magnetic shielding cylinder structure; The clamping device includes a fixing block at one end and a pressing block at the other end located in the inner cavity of the oven. An air chamber is formed between the fixing block and the pressing block. The surface of the fixing block in the air chamber is the installation positioning reference of the air chamber. A sliding guide rail for the pressing block is provided on the inner wall of the oven so that the pressing block presses the air chamber along the sliding guide rail.

2. The compact spin-free exchange-relaxation biaxial inertial measurement structure according to claim 1, characterized in that, The oven is equipped with a temperature control component, which includes a combination of a heat-generating coil, a temperature-sensing resistor, and a temperature control circuit. The temperature control component is used to uniformly raise and maintain the temperature of the atomic ensemble, thereby increasing the atomic number density, enhancing the sensitivity of atoms to inertial information, and improving the signal-to-noise ratio.

3. The compact spin-free exchange-relaxation biaxial inertial measurement structure according to claim 1, characterized in that, The magnetic field assembly includes an external demagnetizing fixture, an internal demagnetizing fixture, and an inter-cylinder fixture. The magnetic field assembly is used to provide a weak magnetic field environment and a magnetic field excitation signal, thereby reducing the sensitivity of atoms to external interference magnetic fields, improving the coherence of atomic spins, and achieving the purpose of manipulating the atomic ensemble with a magnetic field.

4. The compact spin-free exchange-relaxation biaxial inertial measurement structure according to claim 1, characterized in that, The main structure is provided with a shielding cover, the top surface of the shielding cover is provided with a cover handle, the side of the shielding cover is provided with a wiring plate, and the bottom surface of the main structure is provided with a bottom angle iron.

5. The compact spin-free exchange-relaxation biaxial inertial measurement structure according to claim 1, characterized in that, A magnetic field manipulation coil is installed on the coil support cylinder to generate an internal magnetic field.

6. The compact spin-free exchange-relaxation biaxial inertial measurement structure according to claim 1, characterized in that, An optical assembly is installed on the main structure. The optical assembly consists of a laser, optical components and a supporting base plate. The optical assembly is positioned and fixed to the main structure through mating surfaces, alignment holes and screws. The optical assembly is used to provide three laser beams that meet the requirements of power, polarization degree and incident angle, thereby extracting the rotation information in two orthogonal directions sensed by the atoms.

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