Bifocal reflection-type atomic fluorescence detection system for atomic beam interferometer

Abstract

The invention discloses a bifocal reflection-type atomic fluorescence detection system for an atomic beam interferometer. The bifocal reflection-type atomic fluorescence detection system comprises a vacuum cavity, a reflector and a detector, the vacuum cavity is a sealed cavity; an atomic beam generated by an atomic furnace mounted in the vacuum cavity is propagated in the y-axis direction in the vacuum cavity; a window is formed in the cavity wall of the vacuum cavity in the x-axis direction, and detection light enters the vacuum cavity from the window and propagates in the x-axis direction; windows are formed in the opposite positions of the two sides of the vacuum cavity wall in the + / -z axis direction, and a reflecting mirror and a detector are correspondingly installed outside the windows respectively; the propagation directions of the atomic beam and the detection light are perpendicular to each other, and in an intersection area of the atomic beam and the detection light, atoms absorb the detection light to jump to a high energy level and then spontaneously radiate fluorescence, namely an atomic fluorescence light source; the atomic fluorescent light source emits isotropic fluorescent light to the periphery, a part of the light irradiates the reflector and is focused on the receiving end face of the detector after being reflected, and the detector detects a fluorescent signal, converts the fluorescent signal into an electric signal and reads the electric signal.

Description

Technical Field

[0001] This invention relates to a dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer, belonging to the field of atomic fluorescence detection. Background Technology

[0002] Atomic fluorescence detection is a crucial step in obtaining atomic states in atomic interferometers, gyroscopes, accelerometers, and gravimeters, and is of great significance for precision measurements. The fluorescence collection system focuses the fluorescence emitted by atoms onto a detector to obtain the atomic fluorescence signal. Currently, the main collection system uses a set of lenses to collimate and then converge the fluorescence signal onto the detector. However, this lens assembly itself occupies a certain amount of space, and the detector, placed at the focal point of the lenses, also occupies space. These drawbacks are becoming increasingly apparent as atomic interferometers become smaller. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a dual-focus reflective atomic fluorescence detection system for atomic beam interferometers. The system completes the detection by focusing atomic fluorescence photons from the reflective mirror onto the receiving end face of the detector, which greatly reduces the spatial size of the collection device and facilitates the miniaturization design of inertial devices.

[0004] The technical solution of the present invention is: a dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer, comprising: a vacuum cavity, a reflector, and a detector;

[0005] A spatial rectangular coordinate system is established with the center of the atomic fluorescence source as the origin, and the vacuum cavity is a sealed chamber. The atomic beam generated by the atomic furnace installed in the vacuum cavity propagates along the y-axis in the vacuum cavity. A window is opened in the wall of the vacuum cavity along the x-axis, and the detection light enters the vacuum cavity through this window and propagates along the x-axis. Windows are opened on both sides of the vacuum cavity wall at relative positions along the ±z-axis, and a reflector and a detector are respectively installed outside the windows. The propagation directions of the atomic beam and the detection light are perpendicular to each other. In the area where the atomic beam and the detection light intersect, the atoms absorb the detection light and transition to a higher energy level, and then spontaneously emit fluorescence, i.e., the atomic fluorescence source. The atomic fluorescence source emits isotropic fluorescent light in all directions. A portion of the light shines on the reflector, and after reflection, it is focused onto the receiving end face of the detector. The detector detects the fluorescence signal and converts it into an electrical signal, which is then read.

[0006] The reflecting surface of the mirror is a bifocal ellipsoid.

[0007] One focus of the bifocal ellipsoid is located at the center of the atomic fluorescence light source, and the other focus is located at the detector receiving end face.

[0008] Let the distance between the center of the atomic fluorescence source and the receiving end face of the detector be 2c, and let a be the major semi-axis of the mirror ellipsoid. Then the minor semi-axis of the mirror ellipsoid...

[0009] The distance 2c between the center of the atomic fluorescence light source and the detector is 35 mm, the major semi-axis a is 54.19 mm, and the minor semi-axis b is 51.29 mm.

[0010] The depth of the reflecting mirror is: d is the diameter of the mirror.

[0011] The diameter d of the reflector is 25.4 mm, and the depth h of the reflector surface is 1.69 mm.

[0012] The radius of curvature R of the reflecting mirror is 48.54 mm, and the conicity k of the reflecting mirror is -0.1043.

[0013] The distance between the center of the atomic fluorescence light source and the front end face of the reflector is m, and the calculated value is m. ′ =ach, by iteratively adjusting the value of a, so that m' = m.

[0014] The distance m between the center of the atomic fluorescence light source and the front end face of the reflector is 35mm.

[0015] The advantages of this invention compared to the prior art are:

[0016] 1. This invention uses a bifocal ellipsoid as a reflecting mirror, which can collect atomic fluorescence within a certain solid angle range and focus it onto the detector receiving end face, thus realizing the function of a fluorescence collection system.

[0017] 2. This invention requires only a single reflecting mirror to collect fluorescence, resulting in a simple structure and easy installation;

[0018] 3. The reflector used is thin and installed close to the vacuum cavity wall, which confines the process of light collection and focusing within the vacuum cavity. Apart from the device itself, it does not occupy any additional volume outside the vacuum cavity. Compared with the complex lens group of the original collection system, it can reduce a large amount of installation space, saving space for the miniaturization design of the atomic beam interferometer. Attached Figure Description

[0019] Figure 1 This diagram illustrates the configuration of the system of the present invention.

[0020] Figure 2 This diagram illustrates the calculation of the reflector parameters. Detailed Implementation

[0021] The present invention relates to a dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer, comprising: a vacuum cavity 4, a reflector 1, and a detector 3;

[0022] A spatial rectangular coordinate system is established with the center of atomic fluorescence source 2 as the origin. During establishment, it is only necessary to ensure that the center of atomic fluorescence source 2 is the origin; the x-axis can be chosen in any direction within space. Vacuum cavity 4 is a sealed chamber. The atomic beam 5 generated by the atomic furnace installed in vacuum cavity 4 propagates along the y-axis within the vacuum cavity. A window is opened on the wall of vacuum cavity 4 along the x-axis, through which detection light 6 enters vacuum cavity 4 and propagates along the x-axis. Windows are opened on both sides of the wall of vacuum cavity 4 at relative positions along the ±z-axis, with a reflector 1 and a detector 3 respectively installed outside these windows. The propagation directions of the atomic beam and the detection light are perpendicular to each other. In the area where the atomic beam and the detection light intersect, the atoms absorb the detection light and transition to a higher energy level, subsequently spontaneously emitting fluorescence, i.e., atomic fluorescence source 2. This atomic fluorescence source emits isotropic fluorescent light in all directions. A portion of the light illuminates the reflector 1, and after reflection, it is focused onto the receiving end face of detector 3. Detector 3 detects the fluorescence signal and converts it into an electrical signal, which is then read.

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, a spatial rectangular coordinate system is established with the center of the atomic fluorescence light source as the origin. The atomic beam 5 moves along the y-axis in the vacuum cavity 4. The cross-section of the detection light 6 is rectangular and it is incident along the x-axis. In the part of the atomic beam 5 that is irradiated by the detection light 6, the electrons are stimulated to absorb and transition to higher energy levels, and then transition to lower energy levels to emit fluorescence, forming the atomic fluorescence light source 2. The fluorescence propagates isotropically in all directions. Some of the fluorescence is directed towards the reflector 1 and converges on the receiving end face of the detector 3 after reflection by the mirror. The outgoing light 7 and the reflected light 8 are schematic diagrams of the outgoing light from the light source to the reflector and the reflected light after reflection by the mirror to the detector, respectively.

[0025] like Figure 2 The curvature of the reflecting mirror 1 is determined by its relative position to the fluorescent light source 2 and the detector 3. The bifocal reflecting mirror is ellipsoidal, with the fluorescent light source 2 being one focus and the receiving end face of the detector 3 being the other focus. The distance between the two focuses is the focal length of the ellipsoid, denoted by 2c. The distance between the vertex of the ellipsoid and the midpoint of the line connecting the two focuses is the semi-major axis of the ellipsoid, denoted by a. On the yz plane, an ellipse can be drawn using the bifocal focus and the vertex of the semi-major axis. Rotating this ellipse around the line connecting the two focuses forms an ellipsoid, and the reflecting mirror is the arcuate section of the ellipsoid.

[0026] The light source is located in the middle of the vacuum cavity. The reflector and detector are installed outside the vacuum cavity. Light propagates through the vacuum cavity window. Based on the structure of the vacuum cavity, the distance 2c between the center of the light source and the receiving end face of the detector, the distance m between the center of the light source and the front end face of the reflector, and the diameter d of the reflector can be determined. The remaining parameters need to be calculated using the following method. Major semi-axis of the ellipsoid: a = c + m + h; Minor semi-axis of the ellipsoid: Mirror depth: In the above formula, c, m, and d are known. By setting the value of a, the values ​​of b and h can be calculated, thus obtaining the calculated value m' of the distance between the center of the light source and the front surface of the reflector. By iteratively adjusting the value of a until m' is equal to the actual distance m, the semi-major axis a and semi-minor axis b of the ellipsoid can be determined. Then, the surface parameters of the ellipsoid are calculated according to the following formula: Ellipsoid radius of curvature: ellipsoidal conic coefficient:

[0027] The following uses specific data as an example of the invention. Based on the vacuum cavity and installation limitations, the diameter d of the reflector is determined to be 25.4 mm, the distance 2c between the center of the atomic fluorescence source and the detector is 35 mm, and the distance m between the center of the atomic fluorescence source and the front end face of the reflector is 35 mm. An iterative calculation formula is established based on the above formulas. By changing the size of the major semi-axis a, the iterative calculation is performed to make m' = m. After iterative calculation, the major semi-axis a is determined to be 54.19 mm, the minor semi-axis b is 51.29 mm, the depth h of the reflector surface is 1.69 mm, the radius of curvature R of the reflector surface is 48.54 mm, and the conic coefficient k of the reflector surface is -0.1043. Assuming the thickness of the reflector surface at its center is 3 mm, it can be seen from the above data that the total space occupied by the reflector is the sum of the mirror depth and the surface thickness, which is 4.69 mm. If an existing lens-type fluorescence collection system is used, a lens with a diameter of 25.4 mm and a focal length of 35 mm is required as the objective lens, with a center thickness of 7 mm. If the same lens is used as the eyepiece, a focal length of 35 mm must be reserved to focus the light onto the detector. In this case, the total thickness of the lens-type fluorescence collection system reaches 49 mm. In comparison, the volume of the reflective fluorescence collection system described in this invention is reduced to about 1 / 10, which can greatly reduce the volume of the fluorescence collection system and is beneficial for the miniaturization design of atomic beam interferometers.

[0028] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention based on the above-disclosed technical content without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer, characterized in that... include: Vacuum cavity, reflector, and detector; A spatial rectangular coordinate system is established with the center of the atomic fluorescence source as the origin, and the vacuum cavity is a sealed chamber. The atomic beam generated by the atomic furnace installed in the vacuum cavity propagates along the y-axis in the vacuum cavity. A window is opened in the wall of the vacuum cavity along the x-axis, and the external detection light enters the vacuum cavity through the window and propagates along the x-axis. Windows are opened on both sides of the vacuum cavity wall at relative positions along the ±z-axis, and a reflector and a detector are respectively installed outside the windows. The propagation directions of the atomic beam and the detection light are perpendicular to each other. In the region where the atomic beam and the detection light intersect, the atoms absorb the detection light and transition to a higher energy level, and then spontaneously emit fluorescence, which is the atomic fluorescence source. The atomic fluorescence light source emits isotropic fluorescent light in all directions. A portion of the light shines onto the reflector, and after reflection, it is focused onto the receiving end of the detector. The detector detects the fluorescent signal and converts it into an electrical signal, which is then read.

2. The dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 1, characterized in that: The reflecting surface of the mirror is a bifocal ellipsoid.

3. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 2, characterized in that: One focus of the bifocal ellipsoid is located at the center of the atomic fluorescence light source, and the other focus is located at the detector receiving end face.

4. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 3, characterized in that: Let the distance between the center of the atomic fluorescence source and the receiving end face of the detector be 2c, and let a be the major semi-axis of the mirror ellipsoid. Then the minor semi-axis of the mirror ellipsoid...

5. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 4, characterized in that: The distance between the center of the atomic fluorescence light source and the front end face of the reflector is m. Let the calculated value be m. ′ =ach, by iteratively adjusting the value of a, so that m' = m.

6. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 5, characterized in that: The distance m between the center of the atomic fluorescence light source and the front end face of the reflector is 35mm.

7. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 6, characterized in that: The distance 2c between the center of the atomic fluorescence light source and the detector is 35 mm, the major semi-axis a is 54.19 mm, and the minor semi-axis b is 51.29 mm.

8. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 7, characterized in that: The depth of the reflecting mirror is: d is the diameter of the mirror.

9. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 8, characterized in that: The diameter d of the reflector is 25.4 mm, and the depth h of the reflector surface is 1.69 mm.

10. A dual-focus reflective atomic fluorescence detection system for an atomic beam interferometer according to claim 9, characterized in that: The radius of curvature R of the reflecting mirror is 48.54 mm, and the conicity k of the reflecting mirror is -0.1043.

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