Intracavity integrated hollow-core optical fiber coupling device for guide type atom interferometer

Abstract

The invention relates to an intracavity integrated hollow-core optical fiber coupling device for a guide type atom interferometer, belongs to the technical field of hollow-core optical fiber coupling, and solves the problem that the laser coupling effect is influenced by the environment temperature and the like in the prior art. The optical fiber, the first achromatic lens, the second achromatic lens, the hollow optical fiber, the third achromatic lens, the dichroic mirror, the 1 / 4 wave plate and the reflector are sequentially arranged in the vacuum cavity along an optical axis parallel to the central axis of the vacuum cavity; wherein the optical fiber is arranged to extend outwards from the inside of the vacuum cavity to the outside of the vacuum cavity; the dichroic mirror is arranged to form a 45-degree angle with the optical axis.

Description

Technical Field

[0001] The present invention relates to the technical field of hollow fiber coupling, and particularly to an intracavity integrated hollow fiber coupling device for a guided atomic interferometer. Background Art

[0002] Based on the principle of matter wave interference, an atomic interferometer can precisely measure inertial information such as gravity, gravity gradient, and acceleration, and simultaneously significantly improve the theoretical measurement accuracy of fundamental physical constants such as the fine structure constant and the gravitational constant. It has the advantages of ultra-high sensitivity, ultra-high precision, no drift, and no mechanical wear, and is currently a highly concerned application research direction. The fiber-guided atomic interferometer guides cold atomic clouds through hollow fibers, requires less laser power, and can achieve long-distance low-loss and coherent guiding. Due to the strong confinement effect of the guiding light field on the cold atomic cloud, this scheme has outstanding advantages in dynamic environments and vector measurement scenarios.

[0003] In the existing fiber-guided atomic interferometers, the hollow fiber is usually fixed in a vacuum cavity, and the laser coupling device of the hollow fiber is installed outside the vacuum cavity. External laser is coupled into the hollow fiber through the laser coupling device. Since the optical elements constituting the coupling device are arranged outside the vacuum cavity, the optical path is relatively long and complex. In addition, when factors such as the environmental temperature and the installation angle of the vacuum cavity change, the vacuum cavity is extremely prone to minute deformation. This deformation will cause a relative displacement between the hollow fiber and the laser coupling optical path, thereby reducing the excitation efficiency of the fundamental mode of the hollow fiber and causing the excitation of high-order modes, seriously affecting the stability of the atomic interferometer and restricting its performance in complex environments and dynamic application scenarios.

[0004] Therefore, there is a need in the art for an improved hollow fiber laser coupling device for an atomic interferometer that can provide an optimized optical path and can still provide a stable laser coupling effect when the surrounding environment changes. Summary of the Invention

[0005] In view of the above problems, the present invention proposes an intracavity integrated hollow fiber coupling device for a guided atomic interferometer, which installs the hollow fiber and the laser coupling optical path on a coupling platform together and places them inside the vacuum cavity. The coupling platform is connected to the vacuum cavity through an intermediate part, reducing the coupling between the cavity and the laser coupling optical path, and minimizing the influence of cavity deformation caused by factors such as stress and temperature changes on the hollow fiber laser coupling effect; at the same time, this scheme shortens the coupling optical path and places it in an ultra-high vacuum environment, reducing the influence of environmental disturbances on the laser coupling effect and greatly improving the stability of the hollow fiber coupling.

[0006] In view of the above problems, the present invention provides an intracavity integrated hollow fiber coupling device for a guided atom interferometer, which solves the problem in the prior art that changes in factors such as environmental temperature and the installation angle of the vacuum cavity have an adverse effect on the laser coupling effect.

[0007] The present invention provides an intracavity integrated hollow fiber coupling device for a guided atom interferometer, comprising: a vacuum cavity, and sequentially arranged along an optical axis parallel to the central axis of the vacuum cavity in the vacuum cavity: an optical fiber, a first achromatic lens, a second achromatic lens, a hollow fiber, a third achromatic lens, a dichroic mirror, a quarter-wave plate, and a mirror;

[0008] Wherein, the optical fiber is arranged to extend from the inside of the vacuum cavity to the outside of the vacuum cavity;

[0009] The dichroic mirror is arranged at an angle of 45 degrees with respect to the optical axis;

[0010] The position of the first achromatic lens and the optical fiber is set such that the exit end face of the optical fiber is the focal plane of the first achromatic lens;

[0011] The position of the second achromatic lens and the hollow fiber is set such that the entrance end face of the hollow fiber is the focal plane of the second achromatic lens;

[0012] The position of the third achromatic lens and the hollow fiber is set such that the exit end face of the hollow fiber is the focal plane of the second achromatic lens.

[0013] Optionally, the first achromatic lens includes a first large curvature radius surface and a first small curvature radius surface;

[0014] The second achromatic lens includes a second large curvature radius surface and a second small curvature radius surface;

[0015] The third achromatic lens includes a third large curvature radius surface and a third small curvature radius surface;

[0016] Wherein, the first achromatic lens and the second achromatic lens are arranged facing each other such that the first small curvature radius surface faces the second small curvature radius, the first large curvature radius surface faces the optical fiber, and the second large curvature radius surface faces the hollow fiber; and

[0017] The third achromatic lens is arranged such that the third large curvature radius surface faces the hollow fiber and the third small curvature radius surface faces the dichroic mirror.

[0018] Optionally, a support base fixed in the vacuum cavity, the support base is a long strip shape matching the length of the vacuum cavity and extends along the longitudinal direction of the vacuum cavity; and

[0019] The support base is used to support the first achromatic lens, the second achromatic lens, the third achromatic lens, the dichroic mirror, the quarter-wave plate, and the mirror.

[0020] Optionally, the support base includes a first fixing portion and a second fixing portion located at the longitudinal middle position thereof for fixing the support base to the inner wall of the vacuum chamber; wherein, the first fixing portion and the second fixing portion are symmetrically distributed on both sides of the support base with respect to the longitudinal center line of the support base.

[0021] Optionally, the first fixing portion and the second fixing portion respectively include mounting holes, and the first fixing portion and the second fixing portion are fixed to the inner wall of the vacuum chamber through the combination of screws and nuts via the mounting holes, so as to fix the support base to the inner wall of the vacuum chamber.

[0022] Optionally, the in-chamber integrated hollow fiber coupling device for a guided atom interferometer further includes: a fiber support block for fixing the optical fiber to the support base and making the optical fiber coaxial with the optical axis; and a hollow fiber support block for fixing the hollow fiber to the support base and making the hollow fiber coaxial with the optical axis.

[0023] Optionally, the in-chamber integrated hollow fiber coupling device for a guided atom interferometer further includes:

[0024] Inject a first pair of counter-propagating cooling lights, a second pair of counter-propagating cooling lights, and a third pair of counter-propagating cooling lights into the vacuum chamber to form a cold atom cloud;

[0025] Wherein, the directions of the first pair of counter-propagating cooling lights, the second pair of counter-propagating cooling lights, and the third pair of counter-propagating cooling lights are pairwise orthogonal in space;

[0026] The center of the intersection region of the first pair of counter-propagating cooling lights, the second pair of counter-propagating cooling lights, and the third pair of counter-propagating cooling lights is located on the optical axis;

[0027] The cold atom cloud is arranged at the center of the intersection region of the first pair of counter-propagating cooling lights, the second pair of counter-propagating cooling lights, and the third pair of counter-propagating cooling lights.

[0028] Optionally, the intersection region of the first pair of counter-propagating cooling lights, the second pair of counter-propagating cooling lights, and the third pair of counter-propagating cooling lights is located behind the exit end face of the hollow fiber.

[0029] Compared with the prior art, an in-chamber integrated hollow fiber coupling device for a guided atom interferometer provided by an embodiment of the present invention has at least the following beneficial effects.

[0030] (1) The coupling optical path of the present invention is located in an ultra-high vacuum environment, reducing the influence of environmental disturbances such as air flow and temperature on the coupling optical path and improving the stability of the system.

[0031] (2) The coupling optical path of the present invention and the hollow-core fiber are jointly installed on a coupling platform, and the platform is connected to the vacuum cavity through an intermediate part, reducing the coupling between the cavity and the coupling platform and minimizing the influence of cavity deformation on the coupling.

[0032] (3) The present invention integrates the coupling optical path inside the cavity, shortening the distance between the coupling optical path and the hollow-core fiber, greatly improving the integration degree of the system and reducing the influence of the deformation of the coupling optical path on the coupling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. By referring to the drawings, the features and advantages of the present invention can be more clearly understood. The drawings are schematic and should not be construed as any limitation to the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 FIG. is a schematic diagram of an in-cavity integrated hollow-core fiber coupling device for a guided atomic interferometer according to an embodiment of the present invention.

[0035] Figure 2 FIG. is a schematic diagram of the optical path when an in-cavity integrated hollow-core fiber coupling device for a guided atomic interferometer according to an embodiment of the present invention is working.

[0036] Reference Signs:

[0037] 1. Optical fiber;

[0038] 2. Guiding light;

[0039] 3. Raman light;

[0040] 4. First achromatic lens;

[0041] 4-1. First large curvature radius surface;

[0042] 4-2. First small curvature radius surface;

[0043] 5. Second achromatic lens;

[0044] 5-1. Second large curvature radius surface;

[0045] 5-2. Second small curvature radius surface;

[0046] 6. Hollow-core fiber;

[0047] 7. Cold atom cloud;

[0048] 8. First pair of counter-propagating cooling lights;

[0049] 9. The second pair of counter-propagating cooling lights;

[0050] 10. The third pair of counter-propagating cooling lights;

[0051] 11. The third achromatic lens;

[0052] 11-1. The third large radius of curvature surface;

[0053] 11-2. The third small radius of curvature surface;

[0054] 12. Dichroic mirror;

[0055] 13. Quarter-wave plate;

[0056] 14. Reflector;

[0057] 15. Sealing hole;

[0058] 16. Optical fiber support block;

[0059] 17. Support base;

[0060] 18. Hollow optical fiber support block;

[0061] 19-1. The first fixing part;

[0062] 19-2. The second fixing part;

[0063] 20. Vacuum chamber. Detailed implementation manners

[0064] In order to more clearly understand the above-mentioned objects, features, and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0065] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0066] The following provides a detailed description of an intracavity integrated hollow optical fiber coupling device for a guided atom interferometer according to an embodiment of the present invention with reference to the accompanying drawings.

[0067] As Figure 1 shown, a specific implementation manner of the present invention discloses an intracavity integrated hollow optical fiber coupling device for a guided atom interferometer. The following provides a detailed description of an intracavity integrated hollow optical fiber coupling device for a guided atom interferometer of the present invention through this specific embodiment.

[0068] See Figure 1 , a hollow-core fiber coupling device integrated in a cavity for a guided atomic interferometer provided according to an embodiment of the present invention includes a vacuum chamber 20, and sequentially arranged along an optical axis (main optical path) parallel to the central axis of the vacuum chamber 20 in the vacuum chamber 20: an optical fiber 1, a first achromatic lens 4, a second achromatic lens 5, a hollow-core fiber 6, a third achromatic lens 11, a dichroic mirror 12, a quarter-wave plate 13, and a mirror 14. In this embodiment, the hollow-core fiber 6 is a bare fiber. In this embodiment, the optical fiber 1, the first achromatic lens 4, the second achromatic lens 5, the hollow-core fiber 6, the third achromatic lens 11, the dichroic mirror 12, the quarter-wave plate 13, and the mirror 14 in the vacuum chamber 20 together form a coupling optical path, and the optical centers of the respective optical components are arranged on the optical axis longitudinally extending in the vacuum chamber 20. Among the two ends of the vacuum chamber 20, the end close to the mirror 14 is a closed end, and the end close to the optical fiber 1 is an optical fiber installation end. Among them, the optical fiber 1 is arranged to extend from inside the optical fiber installation end of the vacuum chamber 20 to outside the vacuum chamber 20, that is, a part of it is inside the vacuum chamber 20, and another part is outside the vacuum chamber 20; specifically, the optical fiber 1 passes through a sealing hole 15 in one end wall of the vacuum chamber 20, and the sealing hole 15 is sealed and bonded by a vacuum adhesive to ensure the vacuum degree inside the vacuum chamber 20. Optionally, the pumping function for the vacuum chamber 20 can be provided by the operation of a vacuum pump, so that the vacuum chamber 20 reaches 10 -8 Pa of ultra-high vacuum. In the following, for each component, the direction in which light is guided by the optical fiber 1 shown in Figure 1 , that is, the direction from below towards the component, is the incident direction, and the corresponding surface is the incident surface; the direction in which light exits from the component, that is, the direction upwards from the component, is the exit direction, and the corresponding surface is the exit surface.

[0069] Continue to refer to Figure 1 , in this embodiment, the dichroic mirror 12 is arranged at an angle of 45 degrees with respect to the optical axis.

[0070] In this embodiment, the first achromatic lens 4 and the second achromatic lens 5 are arranged between the optical fiber 1 and the hollow-core fiber 6; the third achromatic lens 11 is arranged between the hollow-core fiber 6 and the dichroic mirror 12. The quarter-wave plate 13 is arranged between the dichroic mirror 12 and the mirror 14.

[0071] The focal lengths of the first achromatic lens 4, the second achromatic lens 5, and the third achromatic lens 11 are determined according to the mode field diameters of the fundamental modes of the optical fiber 1 and the hollow optical fiber 6. At the same time, the optical centers of the first achromatic lens 4, the second achromatic lens 5, and the third achromatic lens 11 are reasonably set, and the distances between them and the optical fiber 1 and the hollow optical fiber 6 are such that the focal planes of the first achromatic lens 4 and the third achromatic lens 11 coincide with the exit surfaces of the optical fiber 1 and the hollow optical fiber 6 respectively, and the focal plane of the second achromatic lens 5 coincides with the entrance surface of the hollow optical fiber 6. This setting method enables the first achromatic lens 4 and the third achromatic lens 11 to collimate the light emitted from the optical fiber 1 and the hollow optical fiber 6 respectively, and enables the second achromatic lens 5 to focus the light beam collimated by the first achromatic lens 4 onto the center of the hollow optical fiber 6, and the spot size here is equal to the mode field diameter of the fundamental mode of the hollow optical fiber 6. Each of the first achromatic lens 4, the second achromatic lens 5, and the third achromatic lens 11 has two convex surfaces facing in opposite directions, and these two convex surfaces are respectively the large curvature radius surface and the small curvature radius surface according to the size of the curvature radius. Among them, the first achromatic lens 4 includes a first large curvature radius surface 4-1 and a first small curvature radius surface 4-2; the second achromatic lens 5 includes a second large curvature radius surface 5-1 and a second small curvature radius surface 5-2; the third achromatic lens 11 includes a third large curvature radius surface 11-1 and a third small curvature radius surface 11-2. Optionally, the first achromatic lens 4, the second achromatic lens 5, and the third achromatic lens 11 can be made using the double-gluing process. In this embodiment, the first achromatic lens 4, the second achromatic lens 5, and the third achromatic lens 11 are set such that their foci are all on the optical axis, and the first achromatic lens 4 and the second achromatic lens 5 are arranged facing each other, that is, the first small curvature radius surface 4-2 faces the second small curvature radius 5-2; the first large curvature radius surface 4-1 faces the optical fiber 1, and the second large curvature radius surface 5-1 faces the hollow optical fiber 6; the third large curvature radius surface 11-1 faces the hollow optical fiber 6, and the third small curvature radius surface 11-2 faces the dichroic mirror 12.

[0072] In this embodiment, the in - cavity integrated hollow - core fiber coupling device for a guided - type atomic interferometer further includes: a support base 17 fixed in the vacuum chamber 20. The support base 17 is in a long - strip shape matching the length of the vacuum chamber 20 and extends along the longitudinal direction of the vacuum chamber 20. And the support base 17 is used to support the first achromatic lens 4, the second achromatic lens 5, the hollow - core fiber 6, the third achromatic lens 11, the dichroic mirror 12, the quarter - wave plate 13, and the mirror 14. The support base 17 serves as a coupling platform to install the components of the hollow - core fiber 6 and the laser - coupling optical path in the vacuum chamber 20. The support base 17 has a fixing part for fixing the support base 17 to the inner wall of the vacuum chamber 20. Specifically, the support base 17 may include a first fixing part 19 - 1 and a second fixing part 19 - 2. The first fixing part 19 - 1 and the second fixing part 19 - 2 are symmetrically distributed on both sides of the support base 17 with respect to the longitudinal center line of the support base 17, and may also be symmetric with respect to the center - of - gravity position of the support base 17 to provide more stable support and fixation. The first fixing part 19 - 1 and the second fixing part 19 - 2 may respectively include mounting holes, and the first fixing part 19 - 1 and the second fixing part 19 - 2 can be fixed to the inner wall of the vacuum chamber 20 through the combination of screws and nuts via the mounting holes, thereby fixing the support base 17 to the inner wall of the vacuum chamber 20. The first achromatic lens 4, the second achromatic lens 5, the hollow - core fiber 6, the third achromatic lens 11, the dichroic mirror 12, the quarter - wave plate 13, and the mirror 14 are fixed in the vacuum chamber 20 through the support base 17. Optionally, the first achromatic lens 4, the second achromatic lens 5, the hollow - core fiber 6, the third achromatic lens 11, the quarter - wave plate 13, and the mirror 14 are coaxially arranged along the optical axis on the support base 17, and the dichroic mirror 12 is placed at an angle of 45° with respect to the optical axis (main optical path).

[0073] In this embodiment, the in - cavity integrated hollow - core fiber coupling device for a guided - type atomic interferometer further includes: a fiber support block 16 for fixing the optical fiber 1; and a hollow - core fiber support block 18 for fixing the hollow - core fiber 6. The fiber support block 16 and the hollow - core fiber support block 18 are fixed on the support base 17, thereby fixing the optical fiber 1 and the hollow - core fiber 6 on the support base 17 respectively. Their function is to ensure that the optical fiber 1 and the hollow - core fiber 6 are coaxial with other components. The positions where the fiber support block 16 and the hollow - core fiber support block 18 are fixed on the support base 17 correspond to the positions where the optical fiber 1 and the hollow - core fiber 6 are arranged in the vacuum chamber 20 respectively. Optionally, vacuum glue can be used to fix the optical fiber 1 and the hollow - core fiber 6 to the fiber support block 16 and the hollow - core fiber support block 18 respectively.

[0074] The first achromatic lens 4, the second achromatic lens 5, the third achromatic lens 11, the dichroic mirror 12, the quarter-wave plate 13, the mirror 14, the optical fiber support block 15 and the hollow optical fiber support block 18 are all fixed on the support base 17. Optionally, the first achromatic lens 4, the second achromatic lens 5, the third achromatic lens 11, the dichroic mirror 12, the quarter-wave plate 13, the mirror 14, the optical fiber support block 15 and the hollow optical fiber support block 18 are adhesively fixed on the support base 17 using vacuum glue.

[0075] Exemplarily, when the stress changes or thermal expansion occurs, etc., the vacuum chamber 20 will undergo cavity deformation; the support base 17 will also undergo a certain deformation under the influence of the cavity deformation; however, since the first fixing portion 19-1 and the second fixing portion 19-2 are symmetrically distributed along the longitudinal center line of the support base 17, the coupling between the cavity of the vacuum chamber 20 and the support base 17 can be reduced, and the influence of the cavity deformation of the vacuum chamber 20 on the coupled optical path fixed on the support base 17 can be minimized to ensure the stability of the laser coupling effect.

[0076] As Figure 2 shown, in this embodiment, the optical path when the in-cavity integrated hollow optical fiber coupling device for the guided atomic interferometer works further includes: injecting the first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10 into the vacuum chamber 20, and forming a cold atom cloud 7. The first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 1 are three pairs of counter-propagating lasers that are mutually orthogonal in space, that is, the directions of these three pairs of counter-propagating cooling lights are pairwise orthogonal in space. For example, as Figure 1 shown, the directions of these three pairs of counter-propagating cooling lights can be set such that the first pair of counter-propagating cooling lights 8 is incident orthogonally to the support surface direction of the support base 17; the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10 are incident in a direction parallel to the support surface of the support base 17 and at an angle of 45 degrees to the optical axis, and are mutually orthogonal. The first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10 have the same frequency and are slightly deviated from the resonance frequency of the cold atom cloud transition.

[0077] The center of the intersection region of the first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10 is located at a position about 5 mm away from the exit end face of the hollow optical fiber and on the optical axis.

[0078] The cold atom cloud 7 is cooled by the first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10 and is formed at the center of the intersection region of the first pair of counter-propagating cooling lights 8, the second pair of counter-propagating cooling lights 9 and the third pair of counter-propagating cooling lights 10.

[0079] Exemplarily, the cold atom cloud 7 can be set as follows. If the atoms are 87Rb atoms can generate room-temperature atomic gas in the vacuum chamber 20 through a rubidium atomic source. After being cooled by the first pair of counterpropagating cooling lights 8, the second pair of counterpropagating cooling lights 9, and the third pair of counterpropagating cooling lights 10, a cold atom cloud 7 is formed. The frequencies of the first pair of counterpropagating cooling lights 8, the second pair of counterpropagating cooling lights 9, and the third pair of counterpropagating cooling lights 10 can also be selected to be 87 near the D2 line (wavelength is 780 nm) of Rb atoms.

[0080] The following refers to Figure 2 to describe the working process of the intracavity integrated hollow fiber coupling device for a guided atomic interferometer provided according to an embodiment of the present invention.

[0081] The guiding light 2 is used to guide the cold atom cloud 7 into the hollow fiber 6; the Raman light 3 changes the quantum state of atoms through Raman transitions, constructs a Raman light pulse sequence of "π / 2 - π - π / 2", and can cause the cold atom cloud 7 to undergo matter wave beam splitting - reflection - beam combination to form atomic interference.

[0082] The first achromatic lens 4 is used to collimate the guiding light 2 and the Raman light 3 output from the fiber 1 for the first time and output them; the first collimated guiding light and the first collimated Raman light after the first collimation are obtained. Exemplarily, if the atoms studied by this fiber-guided atomic interferometer are 87 Rb atoms, the wavelength of the guiding light 2 can be selected to be 1064 nm, and the wavelength of the Raman light 3 can be 780 nm.

[0083] The second achromatic lens 5 is used to focus the first collimated guiding light and the first collimated Raman light output from the first achromatic lens 4 to obtain the focused guiding light and the focused Raman light. The focused guiding light and the focused Raman light are focused onto the incident end face of the hollow fiber 6, and the first fiber coupling is completed through the hollow fiber 6 to obtain the first fiber-coupled guiding light and the first fiber-coupled Raman light and output them upward from the output end face of the hollow fiber 6.

[0084] The third achromatic lens 11 arranged behind the hollow fiber 6 collimates the first fiber-coupled guiding light and the first fiber-coupled Raman light output from the hollow fiber 6 for the second time to obtain the second collimated guiding light and the second collimated Raman light and output them.

[0085] The dichroic mirror 12 arranged behind the third achromatic lens 11 divides the second collimated guiding light and the second collimated Raman light into two paths to obtain the separated guiding light and the separated Raman light and output them. The separated guiding light is reflected by the dichroic mirror 12 to deviate from the main optical path along the longitudinal optical axis and is emitted in a plane orthogonal to the main optical path; the separated Raman light is transmitted through the dichroic mirror 12 and output to the center of the quarter-wave plate 13.

[0086] After the separated Raman light is transmitted through the quarter-wave plate 13, the first Raman light is obtained and output to the mirror 14.

[0087] The mirror 14 behind the quarter-wave plate 13 reflects the first Raman light to reverse the optical path and obtain the reflected Raman light; the propagation direction of the reflected Raman light is opposite to the direction of the Raman light incident on the mirror 14 described above.

[0088] The reflected Raman light passes through the quarter-wave plate 13 again to obtain the second Raman light. The polarization state of the second Raman light is orthogonal to the polarization state of the separated Raman light.

[0089] Any combination of the above optional technical solutions can form an optional embodiment of the present application, which will not be elaborated here one by one.

[0090] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0091] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. An intracavity integrated hollow-core fiber coupling device for a guided atom interferometer, characterized in that: include: A vacuum chamber (20), and an optical fiber (1), a first achromatic lens (4), a second achromatic lens (5), a hollow-core optical fiber (6), a third achromatic lens (11), a dichroic mirror (12), a quarter-wave plate (13), and a reflecting mirror (14) arranged in sequence in the vacuum chamber (20) along an optical axis parallel to the central axis of the vacuum chamber (20); Wherein, the optical fiber (1) is arranged to extend from the inside of the vacuum chamber (20) to the outside of the vacuum chamber (20); The dichroic mirror (12) is arranged to form an angle of 45 degrees with the optical axis; The positions of the first achromatic lens (4) and the optical fiber (1) are arranged such that the emission end face of the optical fiber (1) is the focal plane of the first achromatic lens (4); The positions of the second achromatic lens (5) and the hollow-core optical fiber (6) are arranged such that the incident end face of the hollow-core optical fiber (6) is the focal plane of the second achromatic lens (5); The positions of the third achromatic lens (11) and the hollow-core optical fiber (6) are arranged so that the emission end face of the hollow-core optical fiber (6) is the focal plane of the second achromatic lens (5).

2. The cavity-integrated hollow-core fiber coupling device for a guided atom interferometer according to claim 1, characterized in that: The first achromatic lens (4) comprises a first large curvature radius surface (4-1) and a first small curvature radius surface (4-2); The second achromatic lens (5) comprises a second large curvature radius surface (5-1) and a second small curvature radius surface (5-2); The third achromatic lens (11) comprises a third large curvature radius surface (11-1) and a third small curvature radius surface (11-2); The first achromatic lens (4) and the second achromatic lens (5) are arranged opposite to each other, so that the first small curvature radius surface (4-2) is opposite to the second small curvature radius surface (5-2), the first large curvature radius surface (4-1) faces the optical fiber (1), and the second large curvature radius surface (5-1) faces the hollow core optical fiber (6); and The third achromatic lens (11) is arranged such that the third large curvature radius surface (11-1) faces the hollow core optical fiber (6), and the third small curvature radius surface (11-2) faces the dichroic mirror (12).

3. The intracavity integrated hollow core fiber coupling device for guided atom interferometer according to claim 1, characterized in that: Also includes: A support base (17) fixed in the vacuum chamber (20), the support base (17) being in a long strip shape matching the length of the vacuum chamber (20) and extending in the longitudinal direction of the vacuum chamber (20); and The supporting base (17) is used to support the first achromatic lens (4), the second achromatic lens (5), the third achromatic lens (11), the dichroic mirror (12), the quarter wave plate (13) and the reflecting mirror (14).

4. The intracavity integrated hollow core fiber coupling device for guided atom interferometer according to claim 3, characterized in that: The support base (17) comprises a first fixing portion (19-1) and a second fixing portion (19-2) located in the middle of the longitudinal direction thereof, and used for fixing the support base (17) to the inner wall of the vacuum chamber (20); The first fixing portion (19-1) and the second fixing portion (19-2) are symmetrically distributed on both sides of the support base (17) with respect to a longitudinal midline of the support base (17).

5. The cavity-integrated hollow-core fiber coupling device for a guided atom interferometer according to claim 4, characterized in that: The first fixing part (19-1) and the second fixing part (19-2) respectively include mounting holes, and the first fixing part (19-1) and the second fixing part (19-2) are fixed to the inner wall of the vacuum chamber (20) through the mounting holes by a combination of screws and nuts, thereby fixing the support base (17) to the inner wall of the vacuum chamber (20).

6. The intracavity integrated hollow core fiber coupling device for guided atom interferometer according to claim 3, characterized in that: Also includes: An optical fiber support block (16) for fixing the optical fiber (1) to a support base (17) and making the optical fiber (1) coaxial with the optical axis; and The hollow core optical fiber support block (18) is used to fix the hollow core optical fiber (6) to the support base (17) and make the hollow core optical fiber (6) coaxial with the optical axis.

7. The intracavity integrated hollow core fiber coupling device for guided atom interferometer according to claim 1, characterized in that: Also includes: Injecting a first counter-radiation cooling light (8), a second counter-radiation cooling light (9) and a third counter-radiation cooling light (10) into a vacuum chamber (20) to form a cold atomic cluster (7); The directions of the first oppositely incident cooling light (8), the second oppositely incident cooling light (9) and the third oppositely incident cooling light (10) are orthogonal to each other in space; The center of the intersection area of ​​the first oppositely incident cooling light (8), the second oppositely incident cooling light (9) and the third oppositely incident cooling light (10) is located on the optical axis; The cold atomic group (7) is arranged at the center of the intersection area of ​​the first oppositely incident cooling light (8), the second oppositely incident cooling light (9) and the third oppositely incident cooling light (10).

8. The intracavity integrated hollow-core fiber coupling device for a guided atom interferometer according to claim 7, characterized in that: The intersection area of ​​the first oppositely incident cooling light (8), the second oppositely incident cooling light (9) and the third oppositely incident cooling light (10) is located behind the exit end face of the hollow core optical fiber (6).

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