Vacuum system device in ultra-cold atom interference gyroscope

Abstract

The utility model relates to the technical field of ultra-cold atom experimental devices, in particular to a vacuum system device in an ultra-cold atom interference gyroscope, which comprises a lower vacuum body, a lower vacuum body, an upper vacuum body and a lower vacuum body, the upper vacuum body is connected with a rubidium source, serves as an atom source to provide atoms for the lower vacuum body and is connected with an ion pump to maintain vacuum, and the lower vacuum body is communicated with a cavity of the upper vacuum body through a differential tube. The vacuum cavity of the upper vacuum body is connected with a rubidium source and serves as an atom source to provide atoms for the lower vacuum cavity, BEC is generated in the lower vacuum cavity, the vacuum cavity structure can generate a TOP trap magnetic field which is large enough in the center under the condition that the number of windows of the vacuum cavity is met, meanwhile, the heating value is low, and the efficiency is high. And the experiment requirements of each stage of preparing the ultra-cold atoms are met.

Description

Technical Field

[0001] The utility model relates to the technical field of ultra-cold atom experimental devices, in particular to a vacuum system device in an ultra-cold atom interferometric gyroscope. Background Art

[0002] With the progress of laser cooling and trapping, and laser manipulation technologies, inertial sensors based on the principle of cold atom matter wave interference, such as atomic clocks, atomic gravimeters, gravity gradiometers, and atomic gyroscopes, have achieved miniaturization, high precision, and high stability. These sensors have broad application prospects in high-precision measurement fields such as geological prospecting and aerospace.

[0003] To prepare and apply ultra-cold atoms, experiments need to be carried out in an ultra-high vacuum environment because the collision of background gas with atoms will cause atomic heating, thus affecting its lifetime in the trap. Therefore, the quality of the vacuum system is crucial. To achieve an ultra-high vacuum environment, it is first necessary to develop a vacuum chamber.

[0004] To achieve the high precision and high stability of the sensor, the atomic interference signal needs to have extremely high fringe contrast and signal-to-noise ratio. Currently, the magneto-optical trap (MOT) scheme is generally adopted to solve the problem that it is difficult to balance high throughput and low velocity. The specific method is as follows: first, a strong and slow atomic beam is generated through precooling, and then it is efficiently transmitted to an ultra-high vacuum environment for further cooling and trapping. Commonly used structures include two-dimensional magneto-optical trap (2D MOT) and three-dimensional magneto-optical trap (3D MOT).

[0005] The existing vacuum chambers have the following problems: when the number of windows is satisfied, the coils in three dimensions cannot better approach the atoms; in addition, the heat generation of the existing vacuum chambers does not meet the requirements, and these problems are mainly caused by the structural defects of the existing vacuum chambers. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a vacuum system device in an ultra-cold atom interferometric gyroscope to solve the disadvantages such as the heat generation of the existing vacuum chamber not meeting the requirements in the prior art.

[0007] To achieve the above purpose, the utility model adopts the following technical scheme:

[0008] Design a vacuum system device in an ultra-cold atom interferometric gyroscope, including:

[0009] A lower vacuum body, having a chamber for forming ultra-cold atoms, and a vacuum system is also connected to the lower vacuum body;

[0010] The upper vacuum body is connected to a rubidium source to serve as an atomic source to provide atoms for the lower vacuum body, and is connected to an ion pump to maintain the vacuum, wherein the lower vacuum body is communicated with the chamber of the upper vacuum body through a differential tube.

[0011] Furthermore, the upper vacuum body includes an upper main body, and a plurality of upper windows and a plurality of upper interfaces are arranged on the outer side of the upper main body.

[0012] Furthermore, five upper windows are provided, and four of the upper windows are set as cooling light passing windows, and the other one is a push light observation window;

[0013] The upper interfaces include a rubidium source interface, an ion pump interface, a differential light interface, and a magnetic field coil interface.

[0014] Furthermore, the upper main body is of a cuboid structure;

[0015] The four cooling light passing windows are distributed on the four outer side surfaces of the cuboid structure, and the push light observation window and the differential light interface are respectively arranged on the two end surfaces of the cuboid structure.

[0016] Furthermore, the lower vacuum body includes a lower main body, and a plurality of lower windows and a plurality of lower interfaces are arranged on the outer side of the lower main body.

[0017] Furthermore, the lower windows include three pairs of cooling light windows for the cooling light and the repumping light to pass through;

[0018] It further includes two pairs of optical trap / optical lattice light windows and five expansion windows.

[0019] Furthermore, each pair of lower windows is centrosymmetric with respect to the three-dimensional cavity center, and the axis deviation of each lower window is ≤5′, and the axis deviation angle is 90 o ±5.

[0020] Furthermore, the lower main body is of a polyhedron structure;

[0021] Among them, the four cooling light windows are respectively arranged on the vertical outer side surfaces of the lower main body, and the other two are arranged at the top and bottom ends of the lower main body;

[0022] The two pairs of optical trap / optical lattice light windows are located on the vertical outer side surfaces of the lower main body, and the expansion windows are arranged on the inclined outer side surfaces of the lower main body.

[0023] Furthermore, the vacuum system is an ion pump and a getter pump connected to the lower vacuum body, and the lower vacuum body is provided with a vacuum interface for connecting the ion pump.

[0024] Furthermore, a support system is further included, and the lower vacuum body and the upper vacuum body are both installed on the support system.

[0025] The vacuum system device in the ultra-cold atom interference gyroscope proposed by the present utility model has the beneficial effects that: a novel vacuum cavity structure is designed in the present utility model, which specifically includes an upper vacuum body and a lower vacuum body structure. The vacuum cavity of the upper vacuum body is connected to a rubidium source, which serves as an atomic source to provide atoms for the lower vacuum cavity, and BEC is generated in the lower vacuum cavity. The vacuum cavity structure of the present utility model can generate a sufficiently large TOP trap magnetic field at the center while meeting the number of vacuum cavity windows, and at the same time has a lower heat generation to meet the experimental requirements of each stage for preparing ultra-cold atoms. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a perspective view of the present utility model;

[0027] Figure 2 is a schematic diagram of the differential tube structure of the present utility model;

[0028] Figure 3 is a schematic diagram of the upper main body structure of the present utility model;

[0029] Figure 4 is a schematic diagram of the lower main body structure of the present utility model Figure 1 ;

[0030] Figure 5 is a schematic diagram of the lower main body structure of the present utility model Figure 2 .

[0031] In the figure: 1. Lower vacuum body; 11. Lower main body; 12. Lower window; 13. Lower interface; 121. Cooling light window; 122. Optical trap / optical lattice light window; 123. Expansion window; 124. Vacuum interface; 2. Upper vacuum body; 21. Upper main body; 22. Upper window; 221. Cooling light passing window; 222. Pushing light observation window; 23. Upper interface; 231. Rubidium source interface; 232. Ion pump interface; 233. Differential light interface; 234. Magnetic field coil interface; 3. Differential tube; 4. Getter pump; 5. Support system; 51. Column; 52. Flat plate; 53. Installation frame; 54. Support base. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments.

[0033] Referring to Figures 1-5 which is an embodiment of the present utility model, it discloses a vacuum system device in an ultra-cold atom interference gyroscope. Specifically, the vacuum system device includes:

[0034] The lower vacuum body 1 has a chamber for forming ultra-cold atoms, and a vacuum system is also connected to the lower vacuum body 1;

[0035] The upper vacuum body 2 is connected to a rubidium source to provide atoms for the lower vacuum body 1 as an atomic source, and an ion pump is connected to it to maintain the vacuum. The lower vacuum body 1 communicates with the chamber of the upper vacuum body 2 through a differential tube 3. Specifically, in this embodiment, the differential tube 3 is a tapered thin oxygen-free copper tube, and its two ends are connected to the lower vacuum body 1 and the upper vacuum body 2 by flange interfaces.

[0036] In some embodiments, the upper vacuum body 2 in the present utility model includes an upper main body 21. A 2D MOT is formed in the vacuum chamber inside the upper main body 21. A plurality of upper windows 22 and a plurality of upper interfaces 23 are arranged on the outer side of the upper main body 21. Specifically, the upper main body 21 is a metal body. In addition, the air pressure in the vacuum chamber inside the upper main body 21 is relatively high, about 1×10−8 mbar, and an ion pump is used to maintain the vacuum.

[0037] Based on the above embodiments, in this embodiment, five upper windows 22 are provided, and four of the upper windows 22 are set as cooling light passing windows 221, and the other one is a push light observation window 222;

[0038] The upper interface 23 includes a rubidium source interface 231, an ion pump interface 232, a differential light interface 233, and a magnetic field coil interface 234. It should be noted that the magnetic field coil interface 234 is arranged on the outer side of the upper main body 21 and is set as a threaded hole for firmly connecting the magnetic field coil. One end of the above differential tube 3 is connected to the differential light interface 233.

[0039] In a preferred embodiment, the upper main body 21 in this embodiment is of a cuboid structure; the four cooling light passing windows 221 are distributed on the four outer side surfaces of the cuboid structure, and the push light observation window 222 and the differential light interface 233 are respectively arranged on the two end surfaces of the cuboid structure.

[0040] Specifically, in this embodiment, the length of the 4 cooling light passing windows 221 is 120 mm, the width is 25 mm, the diameter of the push light observation window 222 is 16 mm. The cooling light passing windows 221 and the push light observation window 222 are double-sided coated with anti-reflection films. The central wavelength of the anti-reflection film is 780 nm, and the passing rate ≥ 99%.

[0041] In some embodiments, the lower vacuum body 1 in the present utility model includes a lower main body 11. A plurality of lower windows 12 and a plurality of lower interfaces 13 are arranged on the outer side of the lower main body 11. Of course, the lower main body 11 is also set as a metal body, and a connection port for connecting the other end of the differential tube 3 is arranged on the lower main body 11.

[0042] Furthermore, in this embodiment, the lower window 12 includes three pairs of cooling light windows 121 for the passage of cooling light and repumping light;

[0043] It further includes two pairs of optical trap / optical lattice light windows 122 and five expansion windows 123.

[0044] That is to say, a total of fifteen lower windows 12 of the lower body 11 in this embodiment are provided, among which 11 windows have a diameter of 25 mm, and the window diameters of the two pairs of optical trap / optical lattice light windows 122 are 16 mm.

[0045] On the basis of the above embodiment, in this embodiment, each pair of lower windows 12 is centrosymmetric with respect to the center of the three-dimensional cavity, and the axis deviation of each lower window 12 is ≤5′, and the axis deviation angle is 90 o ±5.

[0046] Specifically, in this embodiment, the five expansion windows 123 can be used for absorption imaging (2), ccd monitoring camera (1), and fluorescence imaging for observing the loading rate (1). All optical windows are coated with an antireflection film, and the antireflection film is 780 nm ± 5 nm and 1064 nm ± 5 nm, with a transmittance ≥ 99%, and the wavefront distortion of the window ≤ λ / 2;

[0047] Moreover, in this embodiment, the lower body 11 is a polyhedral structure;

[0048] Among them, four cooling light windows 121 are respectively arranged on the outer vertical surfaces of the lower body 11, and the other two are arranged at the top and bottom of the lower body 11;

[0049] The two pairs of optical trap / optical lattice light windows 122 are located on the outer vertical surfaces of the lower body 11, and the expansion windows 123 are arranged on the outer inclined surfaces of the lower body 11.

[0050] In a preferred embodiment, the vacuum system in the present invention is an ion pump and a getter pump 4 connected to the lower vacuum body 1. The lower vacuum body 1 has a vacuum interface 124 for connecting the ion pump. The vacuum cavity of the lower body 11 is connected to an ion pump and a getter pump 4 to maintain ultra-high vacuum. The air pressure in the vacuum cavity of the lower body 11 is about 3×10−11 mbar, and BEC is formed in this cavity.

[0051] It should be noted that this embodiment further includes a support system 5, and both the lower vacuum body 1 and the upper vacuum body 2 are installed on the support system 5.

[0052] Preferably, in this embodiment, the support system 5 includes a column 51 and a flat plate 52 fixed on the column 51. The lower vacuum body 1 is fixed on the upper flat plate 52 through a mounting frame 53, and the upper vacuum body 2 is fixed on the upper flat plate 52 through a support base 54.

[0053] In summary, the vacuum chamber configuration proposed by the present invention can meet the vacuum conditions required for ultra-cold atoms or Bose-Einstein condensates, i.e., BEC. This configuration of the vacuum chamber is divided into an upper vacuum body 2, namely the 2D MOT chamber, and a lower vacuum body 1, namely the 3D MOT chamber. The upper vacuum body 2 is connected to a rubidium source and serves as an atomic source to provide atoms for the lower vacuum body 1. Therefore, the air pressure in the vacuum chamber of the upper vacuum body 2 is relatively high, about 1×10^(-8) mbar, and it is a metal chamber. The ion pump connected to it is used to maintain the vacuum. There is a differential tube 3 connected at the junction of the lower vacuum body 1 and the lower vacuum body 1 to maintain the air pressure difference between the upper and lower vacuums. The air pressure in the vacuum of the lower vacuum body 1 is about 3×10^(-11) mbar, and it is also a metal chamber. BEC is formed in this chamber. The lower vacuum body 1 is connected to an ion pump and a getter pump 4 to maintain an ultra-high vacuum. Therefore, the vacuum chamber of the ultra-cold atom experimental device designed by the present invention meets the experimental requirements of each stage for preparing ultra-cold atoms.

[0054] In the present invention, a new type of vacuum chamber structure is designed, which specifically includes the structure of an upper vacuum body 2 and a lower vacuum body 1. The vacuum chamber of the upper vacuum body 2 is connected to a rubidium source and serves as an atomic source to provide atoms for the lower vacuum chamber, and BEC is generated in the lower vacuum chamber. The vacuum chamber structure of the present invention can generate a sufficiently large TOP trap magnetic field at the center while meeting the number of vacuum chamber windows, and at the same time has a relatively low heat generation.

[0055] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered by the protection scope of the present invention.

Claims

1. A vacuum system device in an ultracold atomic interferometer gyroscope, characterized in that: include: A lower vacuum body (1) having a chamber for forming ultracold atoms, and a vacuum system is also connected to the lower vacuum body (1); An upper vacuum body (2), the upper vacuum body (2) is connected to a rubidium source to provide atoms for the lower vacuum body (1) as an atomic source, and is connected to an ion pump for maintaining vacuum, wherein the lower vacuum body (1) is connected to the chamber of the upper vacuum body (2) via a differential tube (3).

2. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 1, characterized in that: The upper vacuum body (2) comprises an upper main body (21), and a plurality of upper windows (22) and a plurality of upper interfaces (23) are arranged on the outer side of the upper main body (21).

3. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 2, characterized in that: Five upper windows (22) are provided, of which four of the upper windows (22) are provided as cooling light passage windows (221), and one is provided as a push light observation window (222); The upper interface (23) comprises a rubidium source interface (231), an ion pump interface (232), a differential optical interface (233) and a magnetic field coil interface (234).

4. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 3, characterized in that: The upper body (21) is a rectangular parallelepiped structure; The four cooling light passage windows (221) are distributed on the four outer sides of the rectangular parallelepiped structure, and the push light observation window (222) and the differential light interface (233) are respectively arranged on the two end faces of the rectangular parallelepiped structure.

5. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 1, characterized in that: The lower vacuum body (1) comprises a lower main body (11), and a plurality of lower windows (12) and a plurality of lower interfaces (13) are arranged on the outer side of the lower main body (11).

6. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 5, characterized in that: The lower window (12) includes three pairs of cooling light windows (121) for cooling light and re-pumping light to pass through; It also includes two pairs of light trap / light lattice light windows (122) and five expansion windows (123).

7. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 6, characterized in that: Each pair of lower windows (12) is symmetrical relative to the center of the three-dimensional cavity, and the axis deviation of each lower window (12) is ≤5', and the axis deviation angle is 90 o ±5.

8. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 6, characterized in that: The lower body (11) is a polyhedral structure; Wherein, four cooling light windows (121) are respectively arranged on the outer vertical surface of the lower body (11), and the other two are arranged on the top and bottom ends of the lower body (11); Two pairs of light trap / light lattice light windows (122) are located on the outer vertical surface of the lower body (11), and the expansion window (123) is arranged on the outer inclined surface of the lower body (11).

9. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 1, characterized in that: The vacuum system comprises an ion pump and a getter pump (4) connected to the lower vacuum body (1), and the lower vacuum body (1) is provided with a vacuum interface (124) for connecting the ion pump.

10. The vacuum system device in the ultracold atom interferometer gyroscope according to claim 1, characterized in that: It also comprises a support system (5), and the lower vacuum body (1) and the upper vacuum body (2) are both mounted on the support system (5).

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