Atomic gas chamber with three-dimensional non-magnetic heating coil and manufacturing method

Abstract

The invention discloses an atomic gas chamber with a three-dimensional non-magnetic heating coil and a manufacturing method, and mainly relates to the field of MEMS microstructure manufacturing processes. The atomic gas chamber comprises a glass circular tube, a cover plate and a heating coil. The manufacturing method of the atomic gas chamber comprises the following steps: cleaning, cutting and polishing the end surface of a circular tube drawn by glass optical fibers, welding a cover plate by laser, and adding alkali metal; the heating coil is arranged on the outer side face of the glass round tube through the processes of Cr shading layer sputtering, photoresist coating, rotary exposure, Cr / Au sputtering and Lift off so as to achieve magnetic field self-shielding, the heating face is perpendicular to the light-transmitting face, and the heating coil is prevented from blocking light rays. According to the atomic gas chamber with the three-dimensional non-magnetic heating coil and the manufacturing method, the problems that the side wall of the atomic gas chamber is rough and the heating coil blocks light in the prior art are solved, and the problem that the coil generates an extra interference magnetic field in electric heating is solved through mutual shielding of magnetic fields of the heating coil.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of MEMS microstructure manufacturing process, and particularly relates to an atomic cell with a three-dimensional non-magnetic heating coil and a manufacturing method. BACKGROUND

[0002] An atomic sensor based on quantum effect has advantages of high sensitivity, low power consumption and long-term stability compared with a traditional sensor. A micro atomic sensor manufactured by a MEMS process can meet the demand of a portable scene and has become a research hotspot. An atomic cell is a core component of the micro atomic sensor, and contains alkali metal atoms and inert gas in the atomic cell. Increasing the density of the alkali metal atoms in the atomic cell can increase the spin exchange collision frequency of the alkali metal atoms and the inert gas atoms, thereby increasing the strength of an output signal, and heating is a direct method for increasing the atomic density. Main heating methods of the atomic cell include hot gas flow heating, laser heating and electric heating. The hot gas flow heating is difficult to realize stable temperature control and increases the volume of the device. The laser heating method increases the power consumption of the device and greatly increases the volume of the device. Therefore, for the miniaturized portable atomic sensor, the electric heating method is the best choice at present.

[0003] Meanwhile, since a magnetic field is a working medium of the atomic sensor, a magnetic field other than a to-be-measured magnetic field will interfere with the normal operation of the atomic sensor. Therefore, under the premise of not introducing an additional magnetic field, heating the atomic cell is a main challenge faced by the development of a high-sensitivity micro atomic sensor.

[0004] A traditional atomic cell is manufactured by etching a cavity on a silicon wafer, and then bonding glass sheets on both sides as light transmission surfaces. However, the above method including etching will make the sidewall roughness of the cavity very high, which reduces the atomic relaxation time and reduces the performance of the atomic sensor. Meanwhile, in the prior art, the light transmission path of the atomic cell and the heating coil coincide, although the heating coil can adopt a transparent conductive material such as ITO, but still causes great attenuation to the transmitted light.

[0005] Therefore, a new type of atomic cell and heating coil are needed to solve the problems of the rough sidewall of the atomic cell in the prior art and the light blocking of the heating coil and the introduction of an additional interference magnetic field. SUMMARY

[0006] Starting from the prior art, the task of the present application is to provide an atomic cell with a three-dimensional non-magnetic heating coil and a manufacturing method, which can solve the problems of the rough sidewall of the atomic cell in the prior art and the light blocking of the heating coil, and solve the problem of the additional interference magnetic field generated in the electric heating through mutual shielding of the magnetic fields of the heating coils.

[0007] According to the content of the present application, the above-mentioned problems are solved by an atomic cell with a three-dimensional non-magnetic heating coil and a manufacturing method.

[0008] In a first aspect of the present application, a manufacturing method of an atomic cell with a three-dimensional non-magnetic heating coil is provided, and the method comprises the following steps: Step S1, manufacturing an atomic cell, wherein the step S1 comprises: Step S11, cleaning and cutting a plurality of glass round tubes into the same length, and fixing the plurality of glass round tubes in a mold, aligning the first end faces of the plurality of glass round tubes with each other, and aligning the second end faces of the plurality of glass round tubes opposite to the first end faces with each other; Step S12, polishing the end faces of the plurality of glass round tubes; Step S13, welding a first cover plate to the first end faces of the plurality of glass round tubes; Step S14, adding an alkali metal into the plurality of glass round tubes; Step S15, welding a second cover plate to the second end faces of the plurality of glass round tubes in a nitrogen environment; and Step S16, cutting and separating the plurality of glass round tubes after welding from the mold to form a plurality of independent atomic cells; and Step S2, arranging a heating coil outside the atomic cell, and the magnetic fields generated by each coil in the heating coil cancel each other out.

[0009] Optionally, the welding manner in the step S13 and the step S15 is laser welding.

[0010] Optionally, the atomic cell is configured as a hollow round tube with two sealed surfaces.

[0011] The step S2 comprises the following steps: Step S21, sputtering a layer of Cr as a light shielding layer on the outer side surface of the cleaned atomic cell; Step S22, coating photoresist on the outer side surface of the atomic cell and performing photoetching; Step S23, sputtering Cr / Au on the outer side surface of the atomic cell; Step S24, removing the excess Cr / Au by a Lift off process; Step S25, removing the light shielding layer; Step S26, depositing a protective layer on the outer side surface of the atomic cell.

[0012] Optionally, along the axial direction of the atomic cell, the winding manner of the heating coil is: The current direction of the first coil of the heating coil is positive; The second coil of the heating coil has a negative current direction and is electrically connected with the first coil of the heating coil; The third coil of the heating coil has a negative current direction and is electrically connected with the second coil of the heating coil; The fourth coil of the heating coil has a positive current direction and is electrically connected with the third coil of the heating coil; The fifth coil of the heating coil has a negative current direction and is electrically connected with the fourth coil of the heating coil; The sixth coil of the heating coil has a positive current direction and is electrically connected with the fifth coil of the heating coil; The seventh coil of the heating coil has a positive current direction and is electrically connected with the sixth coil of the heating coil; The eighth coil of the heating coil has a negative current direction and is electrically connected with the seventh coil of the heating coil; The first coil to the eighth coil of the heating coil form a magnetic field self-shielding unit, and the heating coil is wound in a repeated manner of the unit to realize magnetic field self-shielding of the heating coil.

[0013] Optionally, the photolithography adopts a rotary exposure technology.

[0014] The second aspect of the present application further provides an atomic cell with a three-dimensional non-magnetic heating coil, comprising: a glass round tube; a cover plate, comprising a first cover plate and a second cover plate, the first cover plate is arranged at a first end surface of the glass round tube, and the second cover plate is arranged at a second end surface opposite to the first end surface; and a heating coil, the heating coil is arranged at an outer side surface of the atomic cell, and the magnetic fields generated by the coils of the heating coil offset each other.

[0015] Further, the material of the heating coil comprises Cr / Au.

[0016] Further, the surface where the heating coil of the atomic cell is arranged is arranged to be perpendicular to the light-transmitting surface.

[0017] Further, the glass round tube is prepared by glass fiber drawing.

[0018] The application provides an atomic cell with a three-dimensional non-magnetic heating coil and a manufacturing method, which has at least the following beneficial effects: first, the atomic cell is drawn from a glass optical fiber, and the roughness of the inner wall and the outer wall is low, which is beneficial to prolonging the atomic relaxation time; second, the manufacturing method can manufacture an atomic cell with an arbitrary length according to the needs of an application scene, and meanwhile, through synchronous cleaning, cutting, pouring and polishing treatment of a plurality of glass round tubes, batch production of the atomic cell can be realized, and compared with a traditional etching preparation method, the manufacturing time cost and the economic cost are saved; through reasonable setting of the length of the atomic cell, the problem of short optical path of a traditional atomic cell can be overcome; in addition, the heating surface and the light transmission surface of the atomic cell are perpendicular to each other, and the problem of light attenuation caused by the heating coil in the prior art is solved; in the welding step, the cover plate is connected with the end face by using laser welding, which is a low-temperature welding method, and this is beneficial to the construction of the anti-relaxation coating; finally, the material of the heating coil is the light-proof metal material Cr / Au, which overcomes the limitation that ITO with high resistance and high manufacturing cost is used as the heating layer material in the prior art; and through the rotating exposure mode, a three-dimensional heating coil structure is formed on the outer side of the glass round tube of the atomic cell, the magnetic fields of the heating coils are shielded from each other, and the magnetic field generated by the heating coils does not affect the work of the atomic cell.

[0019] In summary, the atomic cell with the three-dimensional non-magnetic heating coil and the manufacturing method solve the problems of rough side wall and light blocking of the heating coil in the prior art, and through the mutual shielding of the magnetic fields of the heating coils, the problem of extra interference magnetic field generated by the coil in the electric heating is solved. BRIEF DESCRIPTION OF DRAWINGS

[0020] To further clarify the advantages and features of the embodiments of the present application, a more particular description of embodiments of the application will be rendered by reference to specific embodiments thereof which are illustrated in the drawings. It is appreciated that these drawings depict only typical embodiments of the application and are therefore not to be considered limiting of its scope. The same or corresponding elements in the drawings are denoted by the same or similar reference signs.

[0021] Figure 1 Fig. 1 shows a structure schematic diagram of an atomic cell with a three-dimensional non-magnetic heating coil in an embodiment of the present application.

[0022] Figure 2 Fig. 2 shows an internal structure schematic diagram of the atomic cell with the three-dimensional non-magnetic heating coil in the embodiment of the present application.

[0023] Figure 3 Fig. 3 shows a manufacturing method of the atomic cell with the three-dimensional non-magnetic heating coil in the embodiment of the present application.

[0024] Figure 4A method for manufacturing a heating coil according to one embodiment of the present invention is shown.

[0025] Figure 5 The method of winding the heating coil in one embodiment of the present invention is shown. Detailed Implementation

[0026] It should be noted that the components in the various figures may be shown exaggeratedly for illustrative purposes and are not necessarily to scale. In each figure, the same reference numerals are used for components that are identical or have the same function.

[0027] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0028] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0029] It should also be noted that, for clarity and simplicity, only a portion of the components may be shown in the embodiments of the present invention. However, those skilled in the art will understand that, under the teachings of the present invention, the required components can be added according to specific needs. Furthermore, unless otherwise stated, features in different embodiments of the present invention can be combined with each other. For example, a feature in the second embodiment can replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment will also fall within the scope of disclosure or description of this application.

[0030] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values ​​are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".

[0031] Furthermore, the numbering of the steps in the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps may be executed in different orders.

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] Figure 1 A schematic diagram of an atomic gas chamber with a three-dimensional non-magnetic heating coil is shown in one embodiment of the present invention. Figure 1 As shown, the atomic gas chamber mainly consists of three parts: a glass tube, a cover plate, and a heating coil. The first end face and the second end face opposite to the first end face of the glass tube are both polished. The cover plate includes a first cover plate connected to the first end face and a second cover plate connected to the second end face; the surfaces of both the first and second cover plates are also polished.

[0034] The following describes in detail the structure and function of each part of the atomic gas chamber in one embodiment of the present invention: A glass cylinder is configured to form the main body of the atomic gas chamber. The glass cylinder is drawn and cut from glass optical fibers, and serves as the core framework of the atomic gas chamber, supporting the cover plate and heating coil to form a closed atomic activity space.

[0035] The cover plate includes a first cover plate and a second cover plate. The first cover plate is disposed on a first end face of the glass tube, and the second cover plate is disposed on a second end face opposite to the first end face, and is configured to seal the atomic gas cell. In one embodiment of the present invention, the cover plate is made of a glass wafer, which matches the material of the glass tube, and is connected to the glass tube by laser welding, effectively ensuring the sealing of the weld. The cover plate (glass wafer) is located on the light-transmitting surface (first end face and second end face) of the atomic gas cell, and can work with the anti-reflection film disposed on the glass wafer to reduce light attenuation and ensure an effective path for the interaction between atoms and light.

[0036] A heating coil, arranged on the outer surface of the glass tube in a self-shielding manner, is configured to heat the atomic gas chamber. Because the heating coil is arranged on the outer surface of the glass tube and perpendicular to the light-transmitting surfaces (first end face and second end face), it does not obstruct the light transmission path. In one embodiment of the invention, the heating coil is made of Cr / Au, where Cr serves as a processing aid to address the poor adhesion of Au, ensuring a tight bond between Au and the glass tube; Au serves as the core functional layer, achieving high conductivity and low resistance heating.

[0037] Figure 2 A schematic diagram of the internal structure of an atomic gas chamber with a three-dimensional non-magnetic heating coil is shown in one embodiment of the present invention. Figure 2 As shown, the atomic gas chamber is constructed as a hollow cylindrical structure. Its first and second end faces are connected to the first and second cover plates respectively through the first and second end faces of the glass cylindrical tube, forming a hollow cylindrical structure sealed on both sides. The light-transmitting surface of the atomic gas chamber is the first end face and / or the second end face, and its heating surface is the outer surface of the glass cylindrical tube. The two are perpendicular to each other, so arranging a heating coil and / or protective layer on the heating surface will not cause light attenuation.

[0038] The method for fabricating the atomic gas chamber is described in detail below.

[0039] Figure 3 This invention illustrates a method for fabricating an atomic gas chamber with a three-dimensional non-magnetic heating coil, according to one embodiment of the present invention. Figure 3 As shown, specifically, the manufacturing method includes the following steps: Step S1: Fabricating an atomic gas chamber, wherein step S1 includes: Step S11: Clean and cut multiple glass tubes into the same length, and fix the multiple glass tubes in the mold so that the first end faces of the multiple glass tubes are aligned with each other, and the second end faces of the multiple glass tubes opposite to the first end faces are aligned with each other. Step S12: Polish the end faces of the plurality of glass tubes; Step S13: Weld the first cover plate to the first end face of the plurality of glass tubes; Step S14: Add alkali metal to the plurality of glass tubes; Step S15: In a nitrogen atmosphere, weld the second cover plate to the second end face of the plurality of glass tubes; and Step S16: Cut and separate the welded glass tubes from the mold to form multiple independent atomic gas chambers; and Step S2: Arrange the heating coils on the outer side of the atomic gas chamber, and ensure that the magnetic fields generated by each coil in the heating coils cancel each other out.

[0040] In one embodiment of the present invention, in step S11, the mold can be a cylindrical mold. Multiple glass tubes are fixed with wafer clamps and placed vertically in the mold. Low-temperature curing epoxy resin AB liquid is mixed and poured into the mold. After curing for 24 hours, the glass tubes wrapped with resin are taken out of the mold, thereby fixing the multiple glass tubes in the mold.

[0041] In one embodiment of the present invention, in step S12, the end faces of the plurality of glass tubes are polished to achieve a flatness of 1 / 8. .

[0042] In one embodiment of the present invention, in steps S13 and S15, a low-temperature welding method, laser welding, is used to connect the first cover plate to the first end faces of the plurality of glass tubes, and the second cover plate to the second end faces of the plurality of glass tubes, forming a hollow cylindrical tube structure sealed on both sides. In other words, the first cover plate can be a single glass plate arranged on the plane formed by the first end faces of the plurality of glass tubes, and the second cover plate can also be a single glass plate arranged on the plane formed by the second end faces of the plurality of glass tubes. The first and second cover plates should be at least large enough to cover all the first and second end faces of the glass tubes. Subsequently, the first cover plate is connected to the first end faces of the plurality of glass tubes, and the second cover plate is connected to the second end faces of the plurality of glass tubes, by laser welding.

[0043] In one embodiment of the present invention, in step S14, the alkali metal may be rubidium azide, or a mixture of rubidium chloride and barium azide in a 1:1 ratio.

[0044] In one embodiment of the present invention, in step S15, the nitrogen environment can be achieved by using a vacuum chamber to extract the internal pressure of the vacuum chamber to 10. -5 Below par, then fill with 200 torr of nitrogen.

[0045] In one embodiment of the present invention, in step S16, since all the glass tubes are welded together with the first cover plate and the second cover plate, they need to be separated into individual atomic gas chambers by laser cutting.

[0046] In one embodiment of the present invention, laser welding, a low-temperature welding method, is used to connect the cover plate to the end face, which is beneficial for the construction of the anti-relaxation coating.

[0047] In one embodiment of the present invention, an anti-relaxation coating is disposed on the inner surface of the atomic gas cell, which reduces the atomic depolarization rate by reducing alkaline wall collision relaxation. The anti-relaxation coating can be made of paraffin wax, olefins, alkanes, and / or organosilanes. Among these, the failure temperature of the most heat-resistant olefin-based anti-relaxation coating is 150℃-200℃, far lower than the operating temperature of conventional sealing processes (such as anodic bonding at 200-500℃ and flame sintering at 500-1600℃). Therefore, a low-temperature welding method such as laser welding is required to prevent the anti-relaxation coating from failing during welding.

[0048] Figure 4 A method for manufacturing a heating coil according to one embodiment of the present invention is shown. For example... Figure 4 As shown, in one embodiment of the present invention, step S2 specifically includes the following steps: Step S21: Sputter a layer of Cr as a light-shielding layer on the side of the cleaned atomic gas chamber; Step S22: Apply photoresist to the outer surface of the atomic gas chamber and perform photolithography; Step S23: Sputter Cr / Au onto the outer surface of the atomic gas chamber; Step S24: Remove excess Cr / Au using a lift-off process; Step S25: Remove the light-shielding layer; Step S26: Deposit a protective layer on the side of the atomic gas chamber.

[0049] Steps S21 to S26 are described in detail below.

[0050] In one embodiment of the present invention, the atomic gas cell processed in step S1 is cleaned and a Cr layer is sputtered onto its side. Since the glass tube is a transparent material, pre-sputtering a Cr layer on its outer surface can block ultraviolet light penetration, preventing ultraviolet light during photolithography from penetrating the glass tube and causing internal photosensitive exposure, which would lead to distortion of the photolithographic pattern. Simultaneously, the Cr layer can form a chemical adsorption with the glass, enhancing the adhesion of the photoresist to the outer surface of the glass tube during subsequent photolithography processes.

[0051] In one embodiment of the present invention, photoresist is coated on the outer surface of the atomic gas cell as a photosensitive medium for subsequent exposure, and the coil shape is defined by patterning.

[0052] In one embodiment of the present invention, Cr / Au is used to perform photolithography and sputtering on the atomic gas cell via spin exposure. Specifically, the adhesion-conductivity combination of Cr / Au is used to solve the problem of uneven exposure on the outer side of the atomic gas cell by spin exposure, thereby achieving continuous three-dimensional winding of the coil.

[0053] In one embodiment of the present invention, the photoresist in the unexposed area and the excess Cr / Au above it are dissolved by a lift-off process.

[0054] In one embodiment of the present invention, a Cr-removing solution that selectively etches Cr is used to remove the Cr layer pre-sputtered on the outer side of the atomic gas chamber, ensuring that the final atomic gas chamber contains only a patterned Cr / Au layer with no excess Cr residue.

[0055] In one embodiment of the present invention, a protective layer is deposited on the outer surface of the atomic gas chamber to prevent the atomic gas chamber from directly contacting the external environment (such as encapsulating adhesive) and to prevent oxidation or corrosion. The protective layer may be made of silicon dioxide. After depositing the silicon dioxide protective layer on the outer surface of the atomic gas chamber, the silicon dioxide protective layer is etched using an NMC dielectric etching machine to expose the pads.

[0056] In this invention, the magnetic fields of the heating coils themselves are mutually shielded, preventing the magnetic field generated by the heating coils from affecting the operation of the atomic gas chamber. Specifically, the winding method of the heating coils in one embodiment of this invention is described below with reference to the accompanying drawings.

[0057] Figure 5 The method of winding the heating coil in one embodiment of the present invention is shown. For example... Figure 5 As shown, the heating coil can achieve its own magnetic field shielding by using adjacent wires in opposite directions. Specifically, along the axial direction of the atomic gas chamber, the heating coil is wound as follows: The first turn of the heating coil is wound in the forward direction, so the current direction in the first turn is positive. The starting point of the first turn is electrically connected to the external electrode, and the ending point is electrically connected to the starting point of the second turn. The second turn of the heating coil is wound in the opposite direction, so the current direction is negative, and the starting point of the second turn is electrically connected to the ending point of the first turn, while the ending point is electrically connected to the starting point of the third turn. The third turn of the heating coil is wound in the reverse direction, so the current direction is negative, and the starting point of the third turn is electrically connected to the ending point of the second turn, while the ending point is electrically connected to the starting point of the fourth turn. The fourth turn of the heating coil is wound in the forward direction, so the current direction is positive, and the starting point of the fourth turn is electrically connected to the ending point of the third turn, while the ending point is electrically connected to the starting point of the fifth turn. The fifth turn of the heating coil is wound in the reverse direction, so the current direction is negative, and the starting point of the fifth turn is electrically connected to the ending point of the fourth turn, while the ending point is electrically connected to the starting point of the sixth turn. The sixth turn of the heating coil is wound in the forward direction, so the current direction is positive, and the starting point of the sixth turn is electrically connected to the ending point of the fifth turn, while the ending point is electrically connected to the starting point of the seventh turn. The seventh turn of the heating coil is wound in the forward direction, so the current direction is positive, and the starting point of the seventh turn is electrically connected to the ending point of the sixth turn, while the ending point is electrically connected to the starting point of the eighth turn. The eighth turn of the heating coil is wound in the reverse direction, so the current direction is negative, and the starting point of the eighth turn is electrically connected to the ending point of the seventh turn, while the ending point is electrically connected to the starting point of the external electrode or the next magnetic field self-shielding unit. The first to eighth turns of the heating coil form a magnetic field self-shielding unit. By repeating the winding method of the heating coil in the unit, the magnetic field self-shielding of the heating coil is achieved.

[0058] In one embodiment of the present invention, forward winding can be clockwise winding, and reverse winding can be counterclockwise winding. Alternatively, forward winding can be counterclockwise winding, and reverse winding can be clockwise winding.

[0059] In the heating coil described in the embodiments of the present invention, the start and end points of each turn of the heating coil are adjacent on the cylindrical surface, forming an approximately closed current loop. The start point of each turn is electrically connected to the end point of the previous turn, and the end point is electrically connected to the start point of the next turn. Figure 5 The winding method shown makes the magnetic fields of adjacent current segments reverse, and their vector superposition is zero; at the same time, since the heating coil is spirally distributed on the outer side of the atomic gas chamber, the magnetic fields of the current in the axial / circumferential directions are symmetrically canceled, that is, the magnetic field of the heating coil is self-shielded.

[0060] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A method for fabricating an atomic gas chamber with a three-dimensional non-magnetic heating coil, characterized in that, Includes the following steps: Step S1: Fabricating an atomic gas chamber, wherein step S1 includes: Step S11: Clean and cut multiple glass tubes into the same length, and fix the multiple glass tubes in the mold so that the first end faces of the multiple glass tubes are aligned with each other, and the second end faces of the multiple glass tubes opposite to the first end faces are aligned with each other. Step S12: Polish the end faces of the plurality of glass tubes; Step S13: Weld the first cover plate to the first end face of the plurality of glass tubes; Step S14: Add alkali metal to the plurality of glass tubes; Step S15: In a nitrogen atmosphere, weld the second cover plate to the second end face of the plurality of glass tubes; and Step S16: Cut and separate the welded glass tubes from the mold to form multiple independent atomic gas chambers; and Step S2: Arrange the heating coils on the outer side of the atomic gas chamber, and ensure that the magnetic fields generated by each coil in the heating coils cancel each other out.

2. The manufacturing method according to claim 1, characterized in that, The welding method in steps S13 and S15 is laser welding.

3. The manufacturing method according to claim 2, characterized in that, The atomic gas chamber is constructed as a hollow circular tube sealed on both sides.

4. The manufacturing method according to claim 1, characterized in that, Step S2 includes the following steps: Step S21: Sputter a layer of Cr as a light-shielding layer on the outer surface of the cleaned atomic gas chamber; Step S22: Apply photoresist to the outer surface of the atomic gas chamber and perform photolithography; Step S23: Sputter Cr / Au onto the outer surface of the atomic gas chamber; Step S24: Remove excess Cr / Au using a lift-off process; Step S25: Remove the light-shielding layer; Step S26: Deposit a protective layer on the outer surface of the atomic gas chamber.

5. The manufacturing method according to claim 4, characterized in that, Along the axial direction of the atomic gas chamber, the heating coil is wound as follows: The current direction of the first turn of the heating coil is positive. The second turn of the heating coil has a negative current direction and is electrically connected to the first turn of the heating coil; The current direction of the third turn of the heating coil is negative, and it is electrically connected to the second turn of the heating coil; The current direction of the fourth turn of the heating coil is positive, and it is electrically connected to the third turn of the heating coil. The fifth turn of the heating coil has a negative current direction and is electrically connected to the fourth turn of the heating coil. The current direction of the sixth turn of the heating coil is positive, and it is electrically connected to the fifth turn of the heating coil. The current direction of the seventh turn of the heating coil is positive, and it is electrically connected to the sixth turn of the heating coil. The current direction of the eighth turn of the heating coil is negative, and it is electrically connected to the seventh turn of the heating coil. The first to eighth turns of the heating coil form a magnetic field self-shielding unit. By repeating the winding method of the heating coil in the unit, the magnetic field self-shielding of the heating coil is achieved.

6. The manufacturing method according to claim 4, characterized in that, The photolithography employs a rotational exposure technique.

7. An atomic gas chamber with a three-dimensional non-magnetic heating coil, characterized in that, include: glass tube; The cover plate includes a first cover plate and a second cover plate, wherein the first cover plate is disposed on a first end face of the glass tube and the second cover plate is disposed on a second end face opposite to the first end face. as well as A heating coil is arranged on the outer side of the atomic gas chamber, and the magnetic fields generated by each coil in the heating coil cancel each other out.

8. The atomic gas chamber according to claim 7, characterized in that, The heating coil is made of Cr / Au.

9. The atomic gas chamber according to claim 7, characterized in that, The surface where the heating coil of the atomic gas chamber is located is set to be perpendicular to the light-transmitting surface.

10. The atomic gas chamber according to claim 7, characterized in that, The glass tube is fabricated by drawing glass optical fibers.

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