A measuring device and method for the distribution of a hot atomic beam

Abstract

The present application discloses a measuring device and method for the distribution of a hot atomic beam. By using the resonance transition spectrum line of laser and atoms, the distribution of the atomic beam along the outgoing path is obtained by measuring the intensity of the fluorescence signal. The design of physical structures such as the atomic furnace outlet and the collimating slit affects the distribution of the atomic beam. At present, the design of the physical structure is only based on the simulation results of the atomic beam distribution. The experimental measurement of the atomic beam distribution not only conducts an engineering verification on the design of the atomic furnace outlet, but also conducts an engineering test on the processing and assembly conditions of the furnace outlet. In addition, it provides an experimental reference for further improving the atomic beam distribution by optimizing the parameter design of the furnace outlet. Verifying and optimizing the structural design of the physical system according to the measured atomic beam distribution, suppressing the divergence angle of the atomic beam, and improving the collimation characteristics of the atomic beam are beneficial to reducing atomic loss, improving atomic utilization efficiency, increasing the service life of atoms, and promoting the monitoring and control of the atomic beam distribution.

Description

Technical Field

[0001] This application relates to the field of atomic physics technology, and particularly to a measurement device and method for the distribution of a thermal atomic beam current. Background Art

[0002] In the related fields of atomic physics, thermal atomic beams or atomic clusters are often used to conduct experiments on the resonant transitions that occur when atoms interact with lasers. After the atomic furnace is heated, an atomic beam is generated. After the atomic beam enters the interaction region and interacts with the laser, photons are radiated and collected by a fluorescence collection device, and the atomic transition spectrum line is detected. However, the loss of thermal atoms, the utilization efficiency of thermal atoms, and the service life of thermal atoms are limited by the atomic beam current distribution. In addition, the Doppler effect caused by the divergence of the thermal atomic beam is one of the main factors affecting the line width of the detected atomic transition spectrum line.

[0003] In a thermal atomic beam experiment, after the atomic furnace is heated, the thermal atomic vapor is ejected through the collimator tube of the atomic furnace to form an atomic beam current. The collimator tube is used to improve the angular distribution of the atomic beam, reduce the useless atoms scattered into the vacuum chamber, and improve the utilization efficiency of the atomic beam. Before entering the interaction region with the laser, a collimation slit is required to reduce the divergence of the atomic beam.

[0004] When the atomic furnace is heated to a certain temperature, the magnitude of the atomic beam current affects the number of atoms interacting with the laser, thereby determining the signal-to-noise ratio of the atomic transition spectrum line signal. The divergence of the atomic beam current will cause Doppler broadening and affect the line width of the transition spectrum line. The divergence angle of the thermal atomic beam will affect the detection efficiency of atoms and the service life of atoms, and the divergence angle of the atomic beam should be minimized as much as possible.

[0005] Currently, generally, by optimizing the design of the collimator tube at the atomic furnace outlet, the atomic beam current is increased and the divergence angle of the atomic beam is reduced. By optimizing the design and layout of the collimation slit, the influence of the Doppler effect caused by the divergence angle of the atomic beam is reduced. In practical engineering applications, the processing and assembly of the collimator tube at the atomic furnace outlet have a significant impact on the divergence angle and collimation characteristics of the atomic beam. Therefore, there is an urgent need for a practical measurement method and device to evaluate the atomic beam current distribution in order to reduce the influence of processing and assembly and meet the system design specifications. In addition, there is currently no measurement method or device to test the actual influence of the design and layout of the collimation slit on the atomic beam current distribution.

[0006] Application content

[0007] The embodiments of this application provide a measurement device and method for the distribution of a thermal atomic beam current, which solve the problem that there is currently no measurement method or device that can well evaluate the atomic beam current distribution, in order to reduce the influence of processing and assembly and test the actual influence of the design and layout of the collimation slit on the atomic beam current distribution.

[0008] The embodiments of the present application adopt the following technical solutions: The embodiments of the present application provide a measurement device for the distribution of a thermal atomic beam, including a physical system, an optical system, and an electric control system, where:

[0009] The physical system includes an atomic furnace for emitting an atomic beam, a first gas chamber for measuring the planar distribution of the atomic beam, a collimating slit area, and a second gas chamber for measuring the planar distribution of the atomic beam after passing through the collimating slit area. The atomic furnace, the first gas chamber, the collimating slit area, and the second gas chamber are sequentially connected in the same direction, and the atomic beam emitted by the atomic furnace sequentially passes through the first gas chamber, the collimating slit area, and the second gas chamber;

[0010] The optical system includes a laser and a polarization beam splitter prism. The electric control system includes a computer, an electric displacement platform, a first photodetector, and a second photodetector. The laser emits laser light that is incident on the first gas chamber and the second gas chamber after passing through the polarization beam splitter prism. The first photodetector and the second photodetector are respectively arranged outside the first gas chamber and the second gas chamber. The output end of the first photodetector is connected to the computer, and the output end of the second photodetector is connected to the laser;

[0011] The polarization beam splitter prism is installed on the electric displacement platform, and the input end of the electric displacement platform is connected to the computer.

[0012] Further, light windows A1, A2, B1, and B2 are arranged on the first gas chamber. The light windows A1 and A2 are oppositely arranged, the light windows B1 and B2 are oppositely arranged, and the direction in which the light windows A1 and A2 are connected is orthogonal to the direction in which the light windows B1 and B2 are connected. Moreover, the direction in which the light windows A1 and A2 are connected and the direction in which the light windows B1 and B2 are connected are both orthogonal to the direction in which the atomic furnace emits the atomic beam.

[0013] Further, the collimating slit area includes a partition plate connected to the first gas chamber and the second gas chamber, and a slit for the atomic beam to pass through is provided at the center of the partition plate.

[0014] Further, light windows C1, C2, D1, and D2 are arranged on the second gas chamber. The light windows C1 and C2 are oppositely arranged, the light windows D1 and D2 are oppositely arranged, and the direction in which the light windows C1 and C2 are connected is orthogonal to the direction in which the light windows D1 and D2 are connected. Moreover, the direction in which the light windows C1 and C2 are connected and the direction in which the light windows D1 and D2 are connected are both orthogonal to the direction in which the atomic furnace emits the atomic beam.

[0015] The present application also provides a method for measuring the distribution of a thermal atomic beam, including the following steps:

[0016] Define the out - going direction of the hot atomic beam as the y - axis and the vertical direction as the z - axis, and establish an orthogonal rectangular coordinate system;

[0017] Based on the laser, design and build an optical path. The electric displacement platform is horizontally placed in the x - y plane of the orthogonal rectangular coordinate system. Fix the incident optical path of the probe laser on the electric displacement platform, so that the probe laser L1 is incident on the optical window A1 of the physical system from a direction perpendicular to the y - z plane and exits from the optical window A2 opposite to the optical window A1. Install a first photodetector at the optical window B2 to collect and measure the radiation fluorescence signal. Cover the optical window B1 with a light - shielding plate. The first photodetector converts the fluorescence signal into a voltage signal and outputs it to the computer for acquisition. The computer controls the electric displacement platform to move step - by - step along the y - direction and z - direction to obtain the distribution of the atomic beam in the y - z plane;

[0018] One split - beam of the probe laser L1 serves as the frequency - locked laser L2 and is perpendicularly incident on the atomic beam from the optical window C1 and exits from the optical window C2 opposite to the optical window C1. The second photodetector collects and measures the fluorescence signal at the optical window D2. The optical window D1 is covered with a light - shielding plate to obtain the resonance transition spectrum line of the atom, and it is negatively fed back to the laser to realize the locking of the laser frequency;

[0019] After rotating the electric displacement platform by 90°, place it vertically in the y - z plane. Fix the incident optical path of the probe laser L1 on the electric displacement platform and adjust the optical path so that the probe laser L1 is perpendicularly incident on the atomic beam from the optical window B2 and exits from the opposite optical window B1. Install a first photodetector at the horizontal optical window A1 to measure the intensity of the fluorescence signal, and install a light - shielding plate at the opposite optical window A2. The computer controls the electric displacement platform to move step - by - step along the x - direction and y - direction to obtain the distribution of the atomic beam in the x - y plane;

[0020] Based on the measurement data, obtain the spatial distribution of the atomic beam after the hot atomic vapor sprays out from the collimator of the atomic furnace;

[0021] Adjust the optical path so that the frequency - locked laser L2 is incident from the front - acting area optical window A1 and exits from the optical window A2. The first photodetector is placed at the optical window B2 to collect the fluorescence signal, and a light - shielding plate is installed at the optical window B1. The incident optical path of the probe laser L1 is fixed on the electric displacement platform. The probe laser L1 is incident from the corresponding optical window of the second gas chamber and the fluorescence signal is collected outside the second gas chamber. Repeat the above steps to measure the distribution of the atomic beam after the collimating slit in the y - z plane and the x - y plane.

[0022] Further, in the process of obtaining the distribution of the atomic beam in the x-y plane, in the post-action area, a split beam of the detection laser L1 serves as the frequency-locking laser L2 and perpendicularly enters the atomic beam from the optical window D2, and exits from the optical window D1 opposite to the optical window D2; the second photodetector collects and measures the fluorescence signal at the optical window C2, and the optical window C1 covers the light-shielding plate to obtain the resonance transition spectrum line of the atoms, and a negative feedback is applied to the laser to lock the laser frequency.

[0023] Further, the computer controls the electric displacement platform to step-move along the y-direction and z-direction to obtain the distribution of the atomic beam in the y-z plane. Specifically, the computer controls the electric displacement platform to adjust the incident position of the detection laser L1, the computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeating this process, a two-dimensional scan of the incident position of the detection laser L1 within the range of the optical window A1 is completed; the intensity of the radiated fluorescence signal is normalized to obtain the distribution of the atomic beam in the y-z plane.

[0024] Further, the computer controls the electric displacement platform to step-move along the x-direction and y-direction to obtain the distribution of the atomic beam in the x-y plane. Specifically, the computer controls the electric displacement platform to adjust the incident position of the detection laser L1, the computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeating this process, a two-dimensional scan of the incident position of the detection laser L1 within the range of the optical window B2 is completed; the intensity of the radiated fluorescence signal is normalized to obtain the distribution of the atomic beam in the x-y plane.

[0025] Further, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 enters from the corresponding optical window of the second gas chamber, the fluorescence signal is collected outside the second gas chamber to measure the planar distribution of the atomic beam after the collimating slit. Specifically, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters from the optical window C1 and exits from the optical window C2 correspondingly. The second photodetector is placed at the optical window D2 to collect the fluorescence signal, and the optical window D1 is installed with a light-shielding plate to measure the y-z plane distribution of the atomic beam after the collimating slit.

[0026] Further, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 enters from the corresponding optical window of the second gas chamber, the fluorescence signal is collected outside the second gas chamber to measure the planar distribution of the atomic beam after the collimating slit. Specifically, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters from the optical window D2 and exits from the optical window D1 correspondingly. The second photodetector is placed at the optical window C1 to collect the fluorescence signal, and the optical window C2 is installed with a light-shielding plate to measure the x-y plane distribution of the atomic beam after the collimating slit.

[0027] The above at least one technical solution adopted in the embodiments of the present application can achieve the following beneficial effects:

[0028] The vacuum physical system of the present application based on a thermal atomic beam uses the radiation fluorescence signal of the resonance transition of atoms and lasers to measure the atomic beam distribution, filling the gap in the measurement and evaluation of the atomic beam distribution. At the same time, it is beneficial to optimize and test the design, processing and assembly of the collimator tube and collimation slit at the atomic furnace outlet. Combining the measurement results of the atomic beam distribution with the simulation results, appropriately increase the length of the collimator tube at the furnace outlet and decrease the diameter of the collimator tube to suppress the divergence angle of the atomic beam. According to the asymmetry of the atomic beam distribution, adjust the assembly angle of the collimator tube so that the atomic beam is symmetrically distributed relative to the collimation slit, optimizing the collimation characteristics of the atomic beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0030] Figure 1 is a schematic structural diagram of the measuring device of the present application;

[0031] Figure 2 is a schematic block diagram of the principle of the measuring device of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0033] The following will describe in detail the technical solutions provided by each embodiment of the present application in conjunction with the drawings.

[0034] Embodiment 1

[0035] The present application discloses a method for measuring the distribution of a thermal atomic beam, including:

[0036] Step 101: Place the atoms in a vacuum physical system. The atoms are ejected from the atomic furnace under heating, interact with the laser when passing through the incident optical window, and collect and measure the radiation fluorescence signal at the detection optical window. The vacuum physical system includes two laser-atom interaction regions before and after, one for measuring the atomic beam distribution; the other for laser frequency locking.

[0037] Step 102: The detection laser incident optical path is fixed on the motorized displacement platform. The detection laser vertically enters the atomic beam from the horizontal incident light window in the front action area and exits from the opposite incident light window, forming a traveling wave field. A pair of detection light windows are orthogonal to the incident light window and the atomic beam exit direction. The photodetector is placed in one of the detection light windows to collect and measure the radiation fluorescence signal and output it to the computer for acquisition. The other detection light window is covered with a light shield to reduce environmental light interference and the influence of radiation fluorescence reflection and scattering.

[0038] Step 103: The computer receives the output signal of the photodetector and performs data acquisition and processing. At the same time, the computer outputs a control signal to adjust the position of the motorized displacement platform through step-by-step control, adjust the incident position of the detection laser, and obtain the longitudinal two-dimensional distribution of the atomic beam.

[0039] Step 104: During the above measurement process, it is necessary to lock the detection laser frequency at the center frequency of the atomic transition to suppress the influence of laser frequency drift. That is, in the rear action area, the split beam of the same laser vertically enters the atomic beam from the horizontal incident light window and exits from the opposite incident light window. The photodetector collects and measures the fluorescence signal in the vertical detection window to obtain the resonance transition spectrum line of the atom, and feeds it back negatively to the laser to achieve laser frequency locking.

[0040] Step 105: The detection laser vertically enters the atomic beam from the vertical direction in the front action area and exits from the opposite light window. Measure the fluorescence signal intensity in the horizontal direction light window, and repeat the above Steps 103 and 104 to measure the transverse two-dimensional distribution of the atomic beam.

[0041] Step 106: Based on the measurement data in Steps 101 - 105, obtain the distribution of the atomic beam along the exit direction. The atomic beam distribution measurement method designed in this application is not only beneficial to optimizing and verifying the furnace mouth design of the atomic beam and testing the processing and assembly conditions of the furnace mouth, but also beneficial to reducing atomic loss, improving atomic utilization efficiency, increasing atomic service life, and promoting the monitoring and control of the atomic beam.

[0042] Similarly, the front action area can be used for laser frequency locking, and the rear action area can be used for the measurement of the atomic beam distribution. Repeat the operations in Steps 101 - 106 above. In this way, the atomic beam distribution after the collimating slit can be measured, which is used to analyze the Doppler effect caused by atomic beam divergence and is beneficial to optimizing and verifying the design of the collimating slit in the vacuum system.

[0043] The principle of the above measurement method is as follows: The incident laser frequency resonates with the atomic transition frequency. In a vacuum system, atoms interact with the laser, transition from the ground state to the excited state, and then return to the ground state after spontaneously emitting photons, repeating the above process. When conditions such as the laser intensity and the interaction time between atoms and the laser remain unchanged, the fluorescence signal intensity is proportional to the number of atoms. The intensity change of the spontaneous emission fluorescence signal can be used to characterize the atomic density distribution. Along the direction of the atomic beam outflow, step-by-step measurement of the intensity change of the spontaneous emission fluorescence signal on its cross-section can obtain the spatial distribution of the atomic beam. At the same time, by using the resonance transition spectral line signal between the laser and atoms, the laser frequency is locked to the atomic transition frequency to reduce the influence of laser frequency drift on the measurement of the fluorescence signal.

[0044] Example 2

[0045] As Figure 1 、 2 shown, the embodiment of the present application provides a measurement device for the distribution of a thermal atomic beam, including a physical system, an optical system, and an electronic control system, where:

[0046] As Figure 1 shown, the physical system includes an atomic furnace for emitting an atomic beam, a first gas chamber for measuring the planar distribution of the atomic beam, a collimating slit area, and a second gas chamber for measuring the planar distribution of the atomic beam after passing through the collimating slit area. The atomic furnace, the first gas chamber, the collimating slit area, and the second gas chamber are sequentially connected in the same direction, and the atomic beam emitted by the atomic furnace sequentially passes through the first gas chamber, the collimating slit area, and the second gas chamber;

[0047] As Figure 2 shown, the optical system includes a laser and a polarization beam splitter prism. The electronic control system includes a computer, an electric displacement platform, a first photodetector, and a second photodetector. The laser emits laser light, which is incident on the first gas chamber and the second gas chamber after passing through the polarization beam splitter prism. The first photodetector and the second photodetector are alternately arranged outside the first gas chamber and the second gas chamber. The output end of the first photodetector is connected to the computer, and the output end of the second photodetector is connected to the laser; at the same time, the polarization beam splitter prism is installed on the electric displacement platform, and the input end of the electric displacement platform is connected to the computer.

[0048] In this embodiment, light windows A1, A2, B1, and B2 are provided on the first gas chamber. Light windows A1 and A2 are oppositely arranged, light windows B1 and B2 are oppositely arranged, and the direction connecting light windows A1 and A2 is orthogonal to the direction connecting light windows B1 and B2. Moreover, the direction connecting light windows A1 and A2 and the direction connecting light windows B1 and B2 are both orthogonal to the direction of the atomic beam emitted by the atomic furnace.

[0049] In this embodiment, the collimating slit region includes a partition plate connected to the first gas chamber and the first gas chamber. A slit for the atomic beam to pass through is provided at the center of the partition plate. As Figure 1 shown, the region between the slits S1 and S2 is the original clock transition region of the atomic clock. In this region, the influence of the divergence of the atomic beam needs to be suppressed, so the slit is provided.

[0050] In this embodiment, optical windows C1, C2, D1, and D2 are provided on the second gas chamber. The optical windows C1 and C2 are arranged opposite to each other, and the optical windows D1 and D2 are arranged opposite to each other. Moreover, the connecting direction of the optical windows C1 and C2 is orthogonal to the connecting direction of the optical windows D1 and D2, and both the connecting direction of the optical windows C1 and C2 and the connecting direction of the optical windows D1 and D2 are orthogonal to the direction of the atomic beam emitted by the atomic furnace.

[0051] The measurement method using the above measurement device is as follows:

[0052] Step 201: Define the outgoing direction of the thermal atomic beam as the y-axis and the vertical direction as the z-axis to establish an orthogonal rectangular coordinate system;

[0053] Step 202: Design and build an optical path based on the laser. The electric displacement platform is horizontally placed in the x-y plane of the orthogonal rectangular coordinate system. The incident optical path of the detection laser is fixed on the electric displacement platform, so that the detection laser L1 is incident on the optical window A1 of the physical system from a direction perpendicular to the y-z plane and exits from the optical window A2 opposite to the optical window A1; a first photodetector is installed at the optical window B2 to collect and measure the radiation fluorescence signal. A light-shielding plate is covered at the optical window B1. The first photodetector converts the fluorescence signal into a voltage signal and outputs it to the computer for acquisition. The computer controls the electric displacement platform to move step by step in the y-direction and z-direction to obtain the distribution of the atomic beam in the y-z plane;

[0054] Step 203: During the measurement process of Step 202, a split beam of the detection laser L1 serves as the frequency-locked laser L2 and is vertically incident on the atomic beam from the optical window C1 and exits from the optical window C2 opposite to the optical window C1; the second photodetector collects and measures the fluorescence signal at the optical window D2, and a light-shielding plate is covered at the optical window D1 to obtain the resonance transition spectrum line of the atoms, and it is negatively fed back to the laser to lock the laser frequency;

[0055] Step 204: After rotating the electric displacement platform by 90°, it is vertically placed in the y-z plane. The incident optical path of the detection laser L1 is fixed on the electric displacement platform, and the optical path is adjusted so that the detection laser L1 is vertically incident on the atomic beam from the optical window B2 and exits from the opposite optical window B1; a first photodetector is installed at the optical window A1 in the horizontal direction to measure the fluorescence signal intensity, and a light-shielding plate is installed at the opposite optical window A2. The computer controls the electric displacement platform to move step by step in the x-direction and y-direction to obtain the distribution of the atomic beam in the x-y plane;

[0056] Step 205: Based on the measurement data in Steps 201 to 204, obtain the spatial distribution of the atomic beam current after the hot atomic vapor jets out from the collimator tube of the atomic furnace.

[0057] Step 206: Adjust the optical path so that the frequency-locked laser L2 enters from the optical window A1 of the front action area and exits from the optical window A2. The first photodetector is placed at the optical window B2 to collect the fluorescence signal, and a light-shielding plate is installed at the optical window B1. The incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 enters from the corresponding optical window of the second gas chamber, the fluorescence signal is collected outside the second gas chamber. Repeat the above Steps 201 to 205 to measure the distribution of the atomic beam current after the collimation slit in the y-z plane and the x-y plane.

[0058] In this embodiment, in the distribution of the atomic beam current measured in Step 204 in the x-y plane, in the rear action area, a split beam of the detection laser L1 serves as the frequency-locked laser L2 and vertically enters the atomic beam current from the optical window D2, and exits from the optical window D1 opposite to the optical window D2. The second photodetector collects and measures the fluorescence signal at the optical window C2, and the optical window C1 is covered with a light-shielding plate to obtain the resonance transition spectrum line of the atom, and negative feedback is applied to the laser to lock the laser frequency.

[0059] In this embodiment, the computer controls the electric displacement platform to step and move along the y-direction and the z-direction to obtain the distribution of the atomic beam current in the y-z plane. Specifically, the computer controls the electric displacement platform to adjust the incident position of the detection laser L1. The computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeat this process to complete the two-dimensional scan of the incident position of the detection laser L1 within the range of the optical window A1. Normalize the intensity of the radiation fluorescence signal to obtain the distribution of the atomic beam current in the y-z plane.

[0060] In this embodiment, the computer controls the electric displacement platform to step and move along the x-direction and the y-direction to obtain the distribution of the atomic beam current in the x-y plane. Specifically, the computer controls the electric displacement platform to adjust the incident position of the detection laser L1. The computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeat this process to complete the two-dimensional scan of the incident position of the detection laser L1 within the range of the optical window B2. Normalize the intensity of the radiation fluorescence signal to obtain the distribution of the atomic beam current in the x-y plane.

[0061] In this embodiment, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters through the corresponding optical window of the second gas chamber and collects the fluorescence signal outside the second gas chamber to measure the planar distribution of the atomic beam after the collimating slit. Specifically, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters through the optical window C1 and exits through the optical window C2 correspondingly. The second photodetector is placed at the optical window D2 to collect the fluorescence signal. A light shield is installed on the optical window D1 to measure the y-z planar distribution of the atomic beam after the collimating slit. Similarly, the incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters through the optical window D2 and exits through the optical window D1 correspondingly. The second photodetector is placed at the optical window C1 to collect the fluorescence signal. A light shield is installed on the optical window C2 to measure the x-y planar distribution of the atomic beam after the collimating slit. Measuring the atomic distribution in the second gas chamber is beneficial to improving the linewidth of the laser frequency locking and enhancing the frequency stability.

[0062] In summary, the vacuum physical system of the present application based on the thermal atomic beam uses the radiation fluorescence signal of the atomic and laser resonance transition to measure the atomic beam distribution, filling the blank of the measurement and evaluation of the atomic beam distribution. At the same time, it is beneficial to optimize and test the design, processing and assembly of the atomic furnace inlet collimating tube and the collimating slit. Combining the measurement results of the atomic beam distribution with the simulation results, appropriately increase the length of the furnace inlet collimating tube and reduce the diameter of the collimating tube to suppress the divergence angle of the atomic beam. According to the asymmetry of the atomic beam distribution, adjust the assembly angle of the collimating tube to make the atomic beam symmetrically distributed relative to the collimating slit and optimize the collimation characteristics of the atomic beam. The design principle of the present application is clear, scientific and engineering realizable, and has a wide application prospect. It is a frontier innovative design in the fields of atomic physics and optics.

[0063] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A measuring device for the distribution of a hot atomic beam, characterized in that, It includes a physical system, an optical system, and an electric control system, where: The physical system includes an atomic furnace for emitting an atomic beam, a first gas chamber for measuring the planar distribution of the atomic beam, a collimating slit area, and a second gas chamber for measuring the planar distribution of the atomic beam after passing through the collimating slit area. The atomic furnace, the first gas chamber, the collimating slit area, and the second gas chamber are sequentially connected in the same direction, and the atomic beam emitted by the atomic furnace sequentially passes through the first gas chamber, the collimating slit area, and the second gas chamber. The optical system includes a laser and a polarization beam splitter prism. The electric control system includes a computer, an electric displacement platform, a first photodetector, and a second photodetector. The laser emits laser light that is incident on the first gas chamber and the second gas chamber after passing through the polarization beam splitter prism. The first photodetector and the second photodetector are respectively arranged outside the first gas chamber and the second gas chamber. The output end of the first photodetector is connected to the computer, and the output end of the second photodetector is connected to the laser. The polarization beam splitter prism is installed on the electric displacement platform, and the input end of the electric displacement platform is connected to the computer.

2. The measuring device for the distribution of a hot atomic beam according to claim 1, characterized in that, Light windows A1, A2, B1, and B2 are arranged on the first gas chamber. The light windows A1 and A2 are oppositely arranged, and the light windows B1 and B2 are oppositely arranged. Moreover, the direction connecting the light windows A1 and A2 is orthogonal to the direction connecting the light windows B1 and B2, and both the direction connecting the light windows A1 and A2 and the direction connecting the light windows B1 and B2 are orthogonal to the direction of the atomic beam emitted by the atomic furnace.

3. The measuring device for the distribution of a hot atomic beam according to claim 1, characterized in that The collimating slit area includes a partition plate connected to the first gas chamber and the second gas chamber, and a slit for the atomic beam to pass through is arranged in the center of the partition plate.

4. The measuring device for the distribution of a hot atomic beam according to claim 1, characterized in that, Light windows C1, C2, D1, and D2 are arranged on the second gas chamber. The light windows C1 and C2 are oppositely arranged, and the light windows D1 and D2 are oppositely arranged. Moreover, the direction connecting the light windows C1 and C2 is orthogonal to the direction connecting the light windows D1 and D2, and both the direction connecting the light windows C1 and C2 and the direction connecting the light windows D1 and D2 are orthogonal to the direction of the atomic beam emitted by the atomic furnace.

5. A method for measuring the distribution of a hot atomic beam, characterized in that, It includes the following steps: Define the exit direction of the hot atomic beam as the y-axis and the vertical direction as the z-axis to establish an orthogonal rectangular coordinate system. Design and build an optical path based on the laser. The electric displacement platform is horizontally placed in the x-y plane of the orthogonal rectangular coordinate system. Fix the detection laser incident optical path on the electric displacement platform so that the detection laser L1 is incident on the light window A1 of the physical system from a direction perpendicular to the y-z plane and exits from the light window A2 opposite to the light window A1. Install a first photodetector on the light window B2 to collect and measure the radiation fluorescence signal. Cover the light window B1 with a light-shielding plate. The first photodetector converts the fluorescence signal into a voltage signal and outputs it to the computer for acquisition. The computer controls the electric displacement platform to step-move along the y-direction and the z-direction to obtain the distribution of the atomic beam in the y-z plane. A split beam of the detection laser L1 serves as the frequency-locked laser L2 and is perpendicularly incident on the atomic beam from the optical window C1, and exits from the optical window C2 opposite to the optical window C1; the second photodetector collects and measures the fluorescence signal at the optical window D2, and the optical window D1 is covered with a light-shielding plate to obtain the resonance transition spectrum line of the atoms, and negative feedback is applied to the laser to lock the laser frequency; After rotating the electric displacement platform by 90°, it is vertically placed in the y-z plane. The incident optical path of the detection laser L1 is fixed on the electric displacement platform, and the optical path is adjusted so that the detection laser L1 is perpendicularly incident on the atomic beam from the optical window B2 and exits from the opposite optical window B1; a first photodetector is installed at the optical window A1 in the horizontal direction to measure the fluorescence signal intensity, and a light-shielding plate is installed at the opposite optical window A2. The computer controls the electric displacement platform to step-move along the x-axis and y-axis to obtain the distribution of the atomic beam in the x-y plane; Based on the measurement data, obtain the spatial distribution of the atomic beam after the hot atomic vapor jets out from the collimator tube of the atomic furnace; Adjust the optical path so that the frequency-locked laser L2 is incident from the front action area optical window A1 and exits from the optical window A2. The first photodetector is placed at the optical window B2 to collect the fluorescence signal, and a light-shielding plate is installed at the optical window B1; the incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 is incident from the corresponding optical window of the second gas chamber, the fluorescence signal is collected outside the second gas chamber. Repeat the above steps to measure the distribution of the atomic beam after the collimation slit in the y-z plane and the x-y plane.

6. The measurement method of a hot atomic beam current distribution according to claim 5, characterized in that, In the obtained distribution of the atomic beam in the x-y plane, in the rear action area, a split beam of the detection laser L1 serves as the frequency-locked laser L2 and is perpendicularly incident on the atomic beam from the optical window D2, and exits from the optical window D1 opposite to the optical window D2; the second photodetector collects and measures the fluorescence signal at the optical window C2, and the optical window C1 is covered with a light-shielding plate to obtain the resonance transition spectrum line of the atoms, and negative feedback is applied to the laser to lock the laser frequency.

7. A method for measuring the distribution of a hot atomic beam according to claim 5, characterized in that, The computer controls the electric displacement platform to step-move along the y-axis and z-axis to obtain the distribution of the atomic beam in the y-z plane. Specifically: the computer controls the electric displacement platform to adjust the incident position of the detection laser L1. The computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeat this process to complete the two-dimensional scanning of the incident position of the detection laser L1 within the range of the optical window A1; normalize the intensity of the emitted fluorescence signal to obtain the distribution of the atomic beam in the y-z plane.

8. A method for measuring the distribution of a hot atomic beam, according to claim 5, characterized in that The computer controls the electric displacement platform to step-move along the x-axis and y-axis to obtain the distribution of the atomic beam in the x-y plane. Specifically: the computer controls the electric displacement platform to adjust the incident position of the detection laser L1. The computer receives the output signal of the first photodetector corresponding to the laser incident position, and performs data acquisition and processing. Repeat this process to complete the two-dimensional scanning of the incident position of the detection laser L1 within the range of the optical window B2; Normalize the intensity of the emitted fluorescence signal to obtain the distribution of the atomic beam in the x-y plane.

9. A method for measuring the distribution of a hot atomic beam according to claim 5, characterized in that, The incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 enters through the corresponding optical window of the second gas chamber, fluorescence signals are collected outside the second gas chamber to measure the planar distribution of the atomic beam behind the collimating slit. Specifically: The incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters through the optical window C1 and exits through the optical window C2 correspondingly. The second photodetector is placed at the optical window D2 to collect the fluorescence signal, and a light shield is installed at the optical window D1 to measure the y-z planar distribution of the atomic beam behind the collimating slit.

10. A method for measuring the distribution of a hot atomic beam according to claim 5, characterized in that, The incident optical path of the detection laser L1 is fixed on the electric displacement platform. After the detection laser L1 enters through the corresponding optical window of the second gas chamber, fluorescence signals are collected outside the second gas chamber to measure the planar distribution of the atomic beam behind the collimating slit. Specifically: The incident optical path of the detection laser L1 is fixed on the electric displacement platform. The detection laser L1 enters through the optical window D2 and exits through the optical window D1 correspondingly. The second photodetector is placed at the optical window C1 to collect the fluorescence signal, and a light shield is installed at the optical window C2 to measure the x-y planar distribution of the atomic beam behind the collimating slit.

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