A parameter self-adaptive setting device and method for a laser-pumped cesium atomic beam clock

Abstract

The application provides a kind of laser pumped cesium atomic beam clock parameter adaptive setting device and method, relating to atomic clock technical field, including cesium beam tube unit;Cesium beam tube drive unit;Frequency stabilization laser light source unit;Acoustooptic frequency shift unit;Crystal oscillator lock frequency unit;Temperature acquisition and control unit;Wherein, main control unit is connected each controlled module by communication interface, and in-machine computer runs host computer software: calculate relative frequency deviation and allan variance, obtain frequency deviation sequence and allan variance data set;Determine the optimal working parameter combination corresponding to peak value;Linkage executes primary temperature control, secondary temperature control and tertiary temperature control, realizes temperature gradient compression and wavelength stability control;Compare real-time monitoring parameters with preset threshold, determine alarm level, thereby trigger system response instruction.The beneficial effects of the application are to reduce labor cost, improve temperature adaptability and improve long-term stability index.

Description

Technical Field

[0001] This invention relates to the field of atomic clock technology, and more specifically, to a device and method for adaptive tuning of parameters of a laser-pumped cesium atomic beam clock. Background Technology

[0002] Cesium atomic beam clocks are generally classified into two types: traditional magnetically selected and novel laser-pumped. Compared to magnetically selected cesium atomic beam clocks, laser-pumped cesium atomic beam clocks have the following advantages: they eliminate the electron multiplier that limits the lifespan of magnetically selected cesium atomic beam clocks, enabling a longer lifespan; the atomic utilization rate is close to 100%, thus improving the stability index by more than one order of magnitude, fundamentally solving the inherent problem of the incompatibility between lifespan and stability in magnetically selected cesium atomic beam clocks, resulting in a longer lifespan; they eliminate the complex beam optics of magnetically selected cesium atomic beam clocks, with the cesium atomic clock moving in a straight line, making the device simpler and facilitating mass production; and they eliminate the selection magnets used in magnetically selected cesium atomic beam clocks, thereby reducing the design difficulty of magnetic shielding and lowering costs.

[0003] However, the introduction of laser technology has led to some problems with laser-pumped cesium atomic beam clocks: 1. The laser is sensitive to temperature and is prone to loss of lock when the ambient temperature changes, thus affecting the overall temperature adaptability of the laser-pumped cesium beam clock. 2. The laser's operating parameters are not constant; that is, as the operating time increases, the laser output intensity will decrease under the same driving current, thus affecting the pumping efficiency and optical frequency shift, and consequently affecting the stability index. 3. The laser-pumped cesium atomic beam clock involves numerous parameters related to lasers, microwaves, atoms, and circuits. The values ​​of these parameters, such as the operating temperature of the cesium atomic gas chamber used for laser frequency locking (hereinafter referred to as the "cesium atomic gas chamber"), the frequency and power of the acousto-optic modulator signal source, the 9.2Hz microwave power, the PID parameters of the crystal oscillator frequency-locking servo circuit, the pump laser intensity, and the detection laser intensity, all affect the overall stability of the laser-pumped cesium atomic beam clock. Therefore, a thorough process is required during the debugging phase to find the optimal configuration, resulting in a large workload and high manpower requirements, which is detrimental to mass production. 4. During long-term operation, issues such as device aging, cesium beam cavity frequency detuning, and changes in fluorescence collection efficiency can cause the microwave power and the operating point of the crystal oscillator frequency-locking servo circuit to deviate from their optimal values, affecting long-term stability. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive tuning device and method for laser-pumped cesium atomic beam clock parameters to improve the aforementioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows:

[0005] In a first aspect, this application provides a laser-pumped cesium atomic beam clock parameter adaptive tuning device, comprising:

[0006] The cesium beam tube unit includes an atomic beam generation region, an atomic state preparation region, a microwave interaction region, and a transition detection region, which are used to realize the interaction between cesium atoms and lasers and microwaves;

[0007] The cesium beam tube drive unit, connected to the cesium beam tube unit, includes an ion pump high-voltage source, a cesium furnace temperature control source, and a C-field constant current source, used to drive the cesium beam tube to work;

[0008] A frequency-stabilized laser source unit, including a laser and a saturated absorption frequency-stabilized optical path, is used to output a frequency-stabilized laser beam;

[0009] The acousto-optic frequency shifter unit receives frequency-stabilized laser light, generates pump laser and probe laser light through an acousto-optic frequency shifter, and includes a light intensity stabilization control module.

[0010] The crystal oscillator frequency locking unit includes a voltage-controlled crystal oscillator, a 9.2GHz microwave source circuit, and a crystal oscillator frequency locking circuit. It is used to extract the error voltage carried by the atomic transition signal and feed it back to the voltage-controlled crystal oscillator to realize the closed-loop locking of the atomic hyperfine energy level transition spectrum line to the voltage-controlled crystal oscillator.

[0011] The temperature acquisition and control unit uses a thermistor and a temperature-controlled fan to monitor and initially regulate the chassis temperature.

[0012] The power supply unit is used to convert externally input AC or DC voltage into multiple isolated DC voltages.

[0013] The parameter adaptive tuning unit includes a main control unit, an on-board computer, and a display screen;

[0014] The main control unit connects to each controlled module via a communication interface, and the on-board computer runs host computer software and is configured as follows:

[0015] The output signal and reference signal of the whole machine are collected by an external frequency stability tester, the relative frequency deviation and Allan variance are calculated, and the frequency deviation sequence and Allan variance dataset are obtained.

[0016] Based on the Allan variance dataset, the parameter peak finding difference algorithm is executed to determine the optimal combination of working parameters corresponding to the peak value.

[0017] In response to the optimal parameter combination and ambient temperature data, primary temperature control, secondary temperature control and tertiary temperature control are executed in a coordinated manner. The primary temperature control adjusts the fan speed to suppress sudden changes in the environment, the secondary temperature control adjusts the laser temperature control target temperature to stabilize the local environment, and the tertiary temperature control compensates for wavelength drift according to the temperature-current mapping relationship, thereby achieving temperature gradient compression and wavelength stability control.

[0018] The alarm level is determined by comparing real-time monitoring parameters with preset thresholds, thereby triggering system response commands, which may include operation maintenance, parameter recalibration, or automatic shutdown.

[0019] Preferably, the cesium bundle tube unit comprises:

[0020] The vacuum chamber contains a cesium furnace, collimation channel, pumping zone optical window, Ramsey cavity, C-field coil, double-layer magnetic shield, fluorescence collector, graphite block, ion pump, and detector zone optical window;

[0021] In this process, the cesium furnace is heated to about 100°C, and cesium atomic vapor forms a cesium atomic beam through the collimation channel. The cesium atomic beam enters the atomic state preparation region through the pump region optical window in sequence, then enters the atomic-microwave interaction region composed of the Ramsey cavity, C field and magnetic shielding, and finally reaches the detection region.

[0022] The detector window allows the detector laser to interact with the cesium atom beam, the fluorescence collector is used to collect the generated fluorescence signal, the graphite block is used for heating or blocking, and the ion pump is used to maintain a high vacuum state throughout the cesium beam tube, ensuring that the diameter of the pump beam is greater than or equal to the diameter of the cesium atom beam generated by the cesium atom beam clock physics module, so that the pump beam within the beam diameter region interacts with the cesium atom beam.

[0023] Preferably, the light intensity stabilization control module of the acousto-optic frequency shifting unit includes:

[0024] Among them, the mirror splits the zeroth order light into the first zeroth order light and the second zeroth order light, the photovoltaic cell receives the second zeroth order light, and the phase-locked frequency doubling power amplifier dynamically adjusts the power according to the change of light intensity to stabilize the detection laser intensity.

[0025] Among them, the frequency-stabilized laser is divided into pump laser and probe laser after being frequency-shifted by AOM acousto-optic. The diameter of the pump laser beam is greater than or equal to the diameter of the cesium atom beam, so that the beam interacts with the atom beam.

[0026] Preferably, the frequency-stabilized laser source unit includes a two-stage temperature control structure: wherein the laser two-stage temperature control covers the laser, and the cesium atom gas chamber temperature control covers the cesium atom gas chamber.

[0027] Secondly, this application also provides an adaptive tuning method for the parameters of a laser-pumped cesium atomic beam clock, comprising:

[0028] Receive relative frequency deviation and Allan variance data sent by an external frequency stability tester;

[0029] Receive and analyze relative frequency deviation and Allan variance data, iterate through and change the controlled parameters of the controlled module according to the preset parameter list, use the peak finding difference algorithm to select the optimal operating parameters corresponding to the peak value, and determine the optimal value of Allan variance and the inflection point of frequency accuracy.

[0030] Based on the optimal value of Allan variance and the inflection point of relative frequency deviation, the parameters of cesium furnace operating temperature, C field current, laser secondary temperature control operating temperature, cesium atom gas chamber operating temperature, AOM drive power, and 9.2GHz signal source output power are adaptively tuned, and the optimal operating parameters corresponding to the peak values ​​are selected.

[0031] The system adaptively performs three-layer temperature measurement and control to obtain adaptive tuning parameters. Based on the tuning parameters, the system monitors the parameter table to trigger an abnormal alarm and automatically shut down the machine. The three-layer temperature measurement and control includes primary temperature control, secondary temperature control, and tertiary temperature control. The primary temperature control involves the main control unit adaptively adjusting the speed of the temperature control fan based on the thermistor measurement and the optimal operating temperature reference value of the whole machine. The secondary temperature control involves adaptively adjusting the operating temperature of the laser secondary temperature control based on the difference between the internal temperature reflected by the thermistor and the optimal operating temperature of the device. The tertiary temperature control involves precise temperature control of the laser tube temperature in the mK range of the laser control circuit.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention features adaptive parameter tuning, overcoming the shortcomings of laser-pumped cesium atomic clocks: To reduce the impact of ambient temperature on the laser, multi-layer temperature control is implemented, and the temperature control temperature of the outer layers can be adaptively tuned according to the ambient temperature, thereby reducing the temperature gradient between the layers and improving the temperature control effect; To reduce light intensity changes, the laser drive current can be adaptively tuned according to light intensity changes; The adaptive parameter tuning allows machines to replace manual optimization of laser, microwave, circuit, and atomic parameters, reducing labor costs; During operation, the microwave power and the operating point of the crystal oscillator frequency-locked servo circuit are automatically tuned, improving long-term stability.

[0034] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the principle structure of the laser-pumped cesium atomic beam clock parameter adaptive tuning device described in this embodiment of the invention;

[0037] Figure 2 This is a schematic diagram of the startup process of the laser-pumped cesium atomic beam clock parameter adaptive tuning device described in this embodiment of the invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] Example 1:

[0041] This invention addresses problems 1-4 mentioned in the background art, specifically: Regarding problem 1, to reduce the impact of ambient temperature on the laser, multi-layer temperature control is required, with the ability to adaptively adjust the temperature of the outer layers based on ambient temperature, thereby reducing the temperature gradient between layers and improving temperature control effectiveness; regarding problem 2, to reduce light intensity variations, the laser drive current needs to be adaptively adjusted based on light intensity changes; regarding problem 3, to free up manpower, adaptive parameter tuning is required, with machines replacing manual optimization of laser, microwave, circuit, and atomic parameters; regarding problem 4, to improve long-term stability, automated tuning of microwave power and the operating point of the crystal oscillator frequency-locked servo circuit is needed during operation. To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0042] like Figure 1 As shown, the present invention comprises eight parts: A. cesium beam tube, B. cesium beam tube driving unit, C. frequency-stabilized laser source unit, D. acousto-optic frequency shifting unit, E. crystal oscillator frequency locking unit, F. chassis temperature acquisition and preliminary control unit, G. power supply unit, and H. parameter adaptive tuning unit.

[0043] This embodiment provides an adaptive tuning device for laser-pumped cesium atomic beam clock parameters. The device includes:

[0044] The cesium beam tube unit includes an atomic beam generation region, an atomic state preparation region, a microwave interaction region, and a transition detection region, which are used to realize the interaction between cesium atoms and lasers and microwaves;

[0045] The cesium beam tube drive unit, connected to the cesium beam tube unit, includes an ion pump high-voltage source, a cesium furnace temperature control source, and a C-field constant current source, used to drive the cesium beam tube to work;

[0046] A frequency-stabilized laser source unit, including a laser and a saturated absorption frequency-stabilized optical path, is used to output frequency-stabilized laser light;

[0047] The acousto-optic frequency shifter unit receives frequency-stabilized laser light, generates pump laser and probe laser light through an acousto-optic frequency shifter, and includes a light intensity stabilization control module.

[0048] The crystal oscillator frequency locking unit includes a voltage-controlled crystal oscillator, a 9.2GHz microwave source circuit, and a crystal oscillator frequency locking circuit. It is used to extract the error voltage carried by the atomic transition signal and feed it back to the voltage-controlled crystal oscillator to realize the closed-loop locking of the atomic hyperfine energy level transition spectrum line to the voltage-controlled crystal oscillator.

[0049] The temperature acquisition and control unit uses a thermistor and a temperature-controlled fan to monitor and initially regulate the chassis temperature.

[0050] The power supply unit is used to convert externally input AC or DC voltage into multiple isolated DC voltages.

[0051] The parameter adaptive tuning unit includes a main control unit, an on-board computer, and a display screen;

[0052] The main control unit connects to each controlled module via a communication interface, and the on-board computer runs host computer software and is configured as follows:

[0053] The output signal and reference signal of the whole machine are collected by an external frequency stability tester, the relative frequency deviation and Allan variance are calculated, and the frequency deviation sequence and Allan variance dataset are obtained.

[0054] Based on the Allan variance dataset, the parameter peak finding difference algorithm is executed to determine the optimal combination of working parameters corresponding to the peak value.

[0055] In response to the optimal parameter combination and ambient temperature data, primary temperature control, secondary temperature control and tertiary temperature control are executed in a coordinated manner. The primary temperature control adjusts the fan speed to suppress sudden changes in the environment, the secondary temperature control adjusts the laser temperature control target temperature to stabilize the local environment, and the tertiary temperature control compensates for wavelength drift according to the temperature-current mapping relationship, thereby achieving temperature gradient compression and wavelength stability control.

[0056] The alarm level is determined by comparing real-time monitoring parameters with preset thresholds, thereby triggering system response commands, which may include operation maintenance, parameter recalibration, or automatic shutdown.

[0057] By sequentially activating the ion pump high-voltage source, cesium furnace temperature control source, laser secondary temperature control, cesium atomic gas temperature control, and laser control and frequency stabilization circuits, the orderly activation and precise control of each component of the atomic clock were ensured, thereby improving the stability and reliability of the system. A step-by-step verification method was adopted, first confirming the normal operation of the ion pump high-voltage source, and then gradually activating other temperature control and laser control units. This effectively avoided system failures due to component malfunctions, enhancing the system's fault tolerance. Precise control of the laser tube and cesium atomic gas chamber temperature, as well as the laser tube current, enabled precise control of the laser frequency, thereby improving the measurement accuracy and long-term stability of the atomic clock.

[0058] Understandably, in this step, the A-cesium beam tube is a vacuum chamber, a place where atoms interact with light and microwaves.

[0059] The system is mainly composed of 10 parts, including: A1-cesium furnace, A2-collimation channel, A4-pump region optical window, A5-Ramsey cavity, A6-C field, A7-double-layer magnetic shield, A8-fluorescence collector, A9-graphite block composition, A10-ion pump, and A11-detector region optical window. Functionally, it is divided into 4 regions, including: atomic beam generation region, atomic state preparation region, atom-microwave interaction region, and atomic transition detection region.

[0060] Specifically, the cesium bundle tube unit includes:

[0061] The vacuum chamber contains a cesium furnace, collimation channel, pumping zone optical window, Ramsey cavity, C-field coil, double-layer magnetic shield, fluorescence collector, graphite block, ion pump, and detector zone optical window;

[0062] In this process, the cesium furnace is heated to 100°C, and cesium atomic vapor forms a cesium atomic beam through a collimation channel. The cesium atomic beam sequentially enters the atomic state preparation region through the pump region optical window, then enters the atomic-microwave interaction region composed of the Ramsey cavity, C field, and magnetic shielding, and finally reaches the detection region.

[0063] The detector window allows the detector laser to interact with the cesium atom beam, the fluorescence collector is used to collect the generated fluorescence signal, the graphite block is used to adsorb the completed cesium atom beam, and the ion pump is used to maintain a high vacuum state throughout the cesium beam tube, ensuring that the diameter of the pump beam is equal to or greater than the diameter of the cesium atom beam, so that the pump beam within the beam diameter region interacts with the cesium atom beam.

[0064] Specifically, the light intensity stabilization control module of the acousto-optic frequency shifting unit includes:

[0065] Among them, the mirror splits the zeroth order light into the first zeroth order light and the second zeroth order light, the photovoltaic cell receives the second zeroth order light, and the phase-locked frequency doubling power amplifier dynamically adjusts the power according to the change of light intensity to stabilize the detection laser intensity.

[0066] Among them, the frequency-stabilized laser is divided into pump laser and probe laser after being frequency-shifted by AOM acousto-optic. The diameter of the pump laser beam is greater than or equal to the diameter of the rubidium atomic beam, so that the beam interacts with the atomic beam.

[0067] Specifically, the frequency-stabilized laser source unit includes a two-stage temperature control structure: wherein the laser two-stage temperature control covers the laser, and the cesium atom gas chamber temperature control covers the cesium atom gas chamber.

[0068] It is understood that in this embodiment, the B-cesium beam tube driving unit is a unit that provides a driving module for the cesium beam tube, ensuring that the cesium beam tube can work normally. It is mainly composed of three parts: B1-ion pump high-pressure source, B2-cesium furnace temperature control source, and B3-C field constant current source.

[0069] In this embodiment, the C-frequency stabilized laser source unit is used to output a single frequency stabilized laser beam. It is mainly composed of 14 parts, including: C1 - laser, C2 - shaped prism pair, C3 - isolator, C4 - half-glass slide, C5 / C17 - PBS, C6 - cesium atom gas cell, C7 - cesium atom gas cell temperature control, C8 - quarter-glass slide, C9 - 0° total reflection mirror, C10 - photodetector, C11 - laser frequency stabilization circuit, C12 - laser control circuit, and C13 - laser secondary temperature control.

[0070] In this embodiment, the D acousto-optic frequency shifting unit is used to generate two laser beams by passing one frequency-stabilized laser beam through the AOM acousto-optic frequency shifter, and to stabilize the laser power by stabilizing the power of the AOM phase-locked loop frequency doubler amplifier. It is mainly composed of 11 parts, including: D1 - convex lens, D2 - AOM, D3 - trapezoidal prism, D4 / D13 / D15 - 45° total reflection mirror, D5 - transmission mirror, D6 / D14 - beam expander, D7 - photovoltaic cell, and D8 - AOM phase-locked loop frequency doubler amplifier.

[0071] In this embodiment, the E-crystal frequency locking unit is used to achieve servo locking of the atom to the local crystal oscillator. It is mainly composed of five parts: E1 - weak signal amplification circuit, E2 - crystal frequency locking circuit, E3 - voltage-controlled crystal oscillator, E4 - differentiation amplification circuit, and E5 - 9.2GHz microwave source circuit.

[0072] In this embodiment, the F chassis temperature acquisition and preliminary control unit indicates the chassis temperature through a thermistor, and the temperature-controlled fan can accept external commands to adjust its speed to initially control the chassis temperature. It mainly consists of two parts: F1 – thermistor, and F2 – temperature-controlled fan.

[0073] In this embodiment, the G power supply unit is used to convert externally input AC or DC power into the voltage required by the internal modules. It mainly consists of two parts: G1 – AC / DC switching circuit and G2 – low-voltage DC / DC circuit. The H parameter adaptive tuning unit is used to automatically adjust the parameters of each unit module within the laser-pumped cesium beam clock to ensure the temperature adaptability and medium-to-long-term stability of the entire laser-pumped cesium beam clock. It mainly consists of three parts: H1 – main control unit, H2 – internal computer, and H3 – display screen.

[0074] It should be noted that the implementation method of this invention mainly includes the following steps:

[0075] Step 1: The G power supply unit generates multiple DC voltages required by the internal modules of the entire machine. This includes: ① The G1-AC / DC switching module converts the externally input 220V AC voltage or 22-75V DC voltage into +48V output to the G2-low voltage DC / DC module; when AC and DC inputs are present simultaneously, AC input is selected first; seamless switching between AC and DC is possible. ② The G2-low voltage DC / DC module converts the input +48V into multiple isolated DC outputs, which power the B cesium beam tube drive unit, C frequency-stabilized laser source unit, D acousto-optic frequency shift unit, E crystal oscillator frequency locking unit, and H parameter adaptive unit respectively.

[0076] Step 2: Under the control of the G-parameter adaptive tuning unit, each controlled module sequentially completes actions such as power-on, scanning, and locking. The controlled modules and parameters for the whole machine's power-on self-locking are shown in Table 1 below.

[0077] Table 1. List of controlled modules and parameters for automatic power-on locking of the entire machine.

[0078]

[0079] Step 3: Driven by the B cesium beam tube driving unit, the A cesium beam tube generates a cesium atom beam. This includes: after the laser-pumped cesium beam clock is powered on, ① the B1-ion pump high-voltage source drives the A10-ion pump to maintain a high vacuum state inside the A cesium beam tube. ② The B3-C field constant current source drives the A6-C field coil to generate a weak magnetic field for the atoms to undergo Zeeman splitting. ③ The B2-cesium furnace temperature control source drives the A1-cesium furnace, heating it to 100℃~130℃. Cesium atoms are ejected from the A1-cesium furnace through the A2-collimator channel, forming the A3-cesium atom beam.

[0080] Step 4: The C-frequency stabilized laser unit generates one frequency stabilized laser beam. This includes: ① The C1-laser, driven by the C12-laser control circuit (temperature control, current control), outputs C14-beam 1; C2-shaping prism shapes the elliptical spot of C14-beam 1 into a circular spot; C3-isolator isolates the influence of the subsequent stage light on the C1-laser; C5-PBS splits C14-beam 1 into two beams: C15-beam 2 and C16-beam 3; C4-1 / 2 glass slide can continuously adjust the intensity distribution of C15-beam 2 and C16-beam 3. ② After passing through the saturated absorption frequency-stabilized optical path structure composed of C17-PBS, C6-cesium atom gas cell, C8-1 / 4 glass slide, and C9-0° total reflection mirror, the phase detection signal required for frequency stabilization of the C1-laser is output by the C10-photodetector and C11-laser frequency-locking circuit, and fed back to the C12-laser control circuit to achieve frequency stabilization of the C1-laser. ③ The C1-laser is a temperature-sensitive device, and a C13-laser secondary temperature control is designed around it to reduce the impact of external temperature changes on its performance. ④ The C6-cesium atom gas cell is a temperature-sensitive device, and a C7-cesium atom gas cell temperature control is designed around it to reduce the impact of external temperature changes on its performance. ⑤ C16-beam 3 is the output of the C-frequency-stabilized laser unit.

[0081] Step 5: The D-acoustic-optic frequency shifting unit outputs pump and probe lasers. This includes: ① The C16-beam 3 input from the C-stabilized laser source unit is focused by the D1-convex lens and then frequency-shifted by the D2-AOM acousto-optic lens, splitting into two laser beams: D9-negative 1st order light and D10-zeroth order light. ② The D9-negative 1st order light passes through the D3-trapezoidal prism, the D13 / D15-45° total reflection mirror, and the D14-beam expander to form the D16-pump laser, which enters the A-cesium beam tube through the A4-pump region light window. ③ The D10-zeroth order light passes through the D5-transmission mirror and is split into two laser beams: D11-zeroth order light 1 and D12-zeroth order light 2. D11-zero order light 1 passes through D6-beam expander and D4-45° total reflection mirror to form D17-probe laser, which enters the A-cesium beam tube through the A11-probe region optical window; D12-zero order light 2 enters D7-photocell, and the D8-AOM phase-locked loop frequency doubling power amplifier monitors the light intensity change and automatically adjusts the power to stabilize the light intensity of D10-zero order light, and thus stabilize the light intensity of D17-probe laser.

[0082] Step 6: The D16-pump laser interacts with cesium atoms to achieve atomic state preparation. The D16-pump laser is perpendicular to the direction of travel of the A3-cesium atom beam. It passes through the A4-pump region optical window and interacts with the A3-cesium atom beam to achieve electric dipole resonance, thereby emptying one of the hyperfine energy levels of the ground state of the cesium atom and achieving atomic state preparation.

[0083] Step 7: The E-crystal frequency-locking unit achieves closed-loop locking of the laser-pumped miniature cesium atomic clock. This includes: ① E3 - a voltage-controlled crystal oscillator outputting a 10MHz signal. ② E4 - a differentiation amplifier circuit that splits the 10MHz signal into three 10MHz outputs: 10MHz_1, 10MHz_2, and 10MHz_3. 10MHz_1 and 10MHz_2 are used for overall output; 10MHz_3 is output to the E5-9.2GHz microwave source circuit. ③ The E5-9.2GHz microwave source circuit, through frequency doubling and synthesis, multiplies the 10MHz signal to 9.2GHz and feeds it into the A5-Ramsey cavity; the cesium atomic clock interacts with the 9.2GHz microwave, completing the microwave transition. ④ D17 - a probe laser perpendicular to the A3-cesium atom beam propagation direction, passes through the A11-detector window, and resonates with cesium atoms via an electric dipole, outputting a fluorescence signal carrying frequency discrimination information through the A8-fluorescence collector. ⑤ The fluorescence signal is amplified by the E1-weak signal amplifier circuit by 10. 6 After multiplying, the VCO of the voltage-controlled crystal oscillator is output through the E2-crystal frequency-locking circuit to servo control the E3-voltage-controlled crystal oscillator, thereby realizing the closed-loop locking of the laser-pumped miniature cesium atomic clock.

[0084] Step 8: Under the control of the G-parameter adaptive tuning unit, during the overall debugging and long-term operation, the controlled parameters of the controlled modules are automatically adaptively tuned to maintain the product's optimal working state. This includes: ① The H-frequency stability tester is an external instrument independent of the laser-pumped miniature cesium atomic clock, used to test the frequency difference between the 10MHz output signal of the laser-pumped miniature cesium atomic clock and the reference 10MHz signal, and to calculate the relative frequency deviation and Allan variance; it is connected to the G2-internal computer via an RS232 serial port; ② The "Frequency Stability Test Host Computer Software" is a self-developed host computer software used to receive the relative frequency deviation and Allan variance data obtained from the H-frequency stability tester, automatically determine the optimal value of Allan variance and the inflection point of frequency accuracy through a preset algorithm, run on the G2-internal computer, and display the results on the G3-display screen. ③ The controlled modules and controlled parameters during the debugging and optimization process are shown in Table 2 below. The G1 main control unit collects and controls the controlled parameters of the controlled modules through the RS232 serial port. The "frequency stability test host computer software" iterates through the preset parameter list and changes the controlled parameters of the controlled modules. The preset algorithm of the "frequency stability test host computer software" selects the optimal parameters to ensure that the whole machine works in the best state. ④ The controlled modules and controlled parameters during the long-term operation of the whole machine are shown in Table 3 below. Adjust the parameter status to ensure that the whole machine works in the best state. ⑤ The monitoring modules and monitoring parameters during the long-term operation of the whole machine are shown in Table 4 below. When the parameters are abnormal, the whole machine alarms; according to the severity of the alarm, the automatic shutdown process is initiated.

[0085] Table 2 List of controlled modules and controlled parameters during debugging and optimization.

[0086]

[0087] Table 3 List of controlled modules and controlled parameters during long-term operation

[0088] Serial Number Controlled module name Controlled parameters 1 F2 - Temperature Control Fan <![CDATA[Fan speed V F2 > 2 C13-Laser Secondary Temperature Control <![CDATA[Laser secondary temperature control operating temperature T C13 > 3 C12 - Laser Control Circuit <![CDATA[Laser tube temperature T C12 > 4 E2-Crystal oscillator frequency lock circuit bias voltage 5 B3-C Field Constant Current Source <![CDATA[C-field current I B3 > 6 E5-9.2GHz microwave source <![CDATA[Output power P of the 9.2 GHz signal source E5 >

[0089] Table 4. List of monitoring modules and parameters during long-term operation

[0090]

[0091] Step 9: Under the control of the G-parameter adaptive tuning unit, implement the one-button shutdown operation. The controlled modules and parameters for the one-button shutdown operation of the whole machine are shown in Table 5 below.

[0092] Table 5. List of controlled modules and controlled parameters for the one-button shutdown operation of the entire machine.

[0093]

[0094] Example 2:

[0095] like Figure 2 As shown in the figure, this embodiment provides an adaptive tuning method for the parameters of a laser-pumped cesium atomic beam clock.

[0096] S100: Receives relative frequency deviation and Allan variance data sent by an external frequency stability tester. The formula for calculating the relative frequency deviation is as follows:

[0097]

[0098] In the formula, f is the output frequency of the laser-pumped cesium atomic clock under test, and f0 is the reference frequency;

[0099] The formula for calculating Allan variance is as follows:

[0100]

[0101] In the formula, τ=mτ0 is the smoothing time, and M′ is... The number of, and Let be the mean of the m relative frequency deviation data within the i-th smoothing time τ, i.e. mτ0 is the smoothing time; M′ is... The number of, and Let be the mean of the m relative frequency deviation data within the i-th smoothing time τ, i.e.

[0102] S200: Receive and analyze relative frequency deviation and Allan variance data, iterate through and change the controlled parameters of the controlled module according to the preset parameter list, and use the peak finding difference algorithm to determine the optimal value of Allan variance and the inflection point of relative frequency deviation.

[0103] S300 adaptively tunes parameters based on the optimal value of Allan variance and the inflection point of relative frequency deviation. This includes the cesium furnace operating temperature, C field current, laser secondary temperature control operating temperature, cesium atom gas chamber operating temperature, AOM drive power, and 9.2GHz signal source output power, selecting the optimal operating parameters corresponding to the peak values.

[0104] It should be noted that the following steps are required:

[0105] Step 1: The F power supply unit generates multiple DC voltages required by the internal modules of the whole machine.

[0106] Includes: ① G1-AC / DC switching module converts external input 220V AC voltage or 22~75V DC voltage into +48V output to G2-low voltage DC / DC module.

[0107] ②The G2-low voltage DC / DC module converts the input +48V into multiple isolated DC outputs, which power the B cesium beam tube drive unit, C frequency-stabilized laser source unit, D acousto-optic frequency shift unit, E crystal oscillator frequency locking unit, and H parameter adaptive unit respectively.

[0108] Step 2: Under the control of the G-parameter adaptive tuning unit, each controlled module is powered on in sequence.

[0109] Step 3: Driven by the B cesium beam drive unit, the A cesium beam generates a cesium atom beam.

[0110] Includes: ①B1-ion pump high-voltage source generates +3300V voltage to drive A10-ion pump to maintain high vacuum state in A cesium beam tube.

[0111] ②The constant current source in field B3-C generates a current of 10-20mA, driving the field coil in field A6-C to generate power. 133 Cs atoms generate a weak magnetic field through Zeeman splitting.

[0112] ③The B2-cesium furnace temperature control source drives the A1-cesium furnace to heat it to 100℃~130℃. 133 Cs atoms are ejected from the A1-cesium furnace through the A2-collimator channel to form A3- 133 Cs atomic beam.

[0113] Step 4: The C-frequency stabilized laser unit generates a frequency stabilized laser beam.

[0114] Includes: ① The C1 laser, driven by the C12 laser control circuit (temperature control, current control), outputs C14 beam 1; C2 shaping prism shapes the elliptical spot of C14 beam 1 into a circular spot; C3 isolator isolates the influence of the subsequent stage light on the C1 laser; C5 PBS splits C14 beam 1 into two beams: C15 beam 2 and C16 beam 3; C4 1 / 2 glass slide can continuously adjust the intensity distribution of C15 beam 2 and C16 beam 3.

[0115] ② After passing through the saturated absorption frequency-stabilized optical path structure composed of C17-PBS, C6-cesium atom gas cell, C8-1 / 4 glass slide, and C9-0° total reflection mirror, the phase detection signal required for frequency stabilization of the C1-laser is output by the C10-photodetector and C11-laser frequency-locking circuit, and fed back to the C12-laser control circuit to realize frequency stabilization of the C1-laser.

[0116] ③The C1-laser is a temperature-sensitive device, and a C13-laser secondary temperature control is designed around it to reduce the impact of external temperature changes on its performance.

[0117] ④ The C6-cesium atom gas cell is a temperature-sensitive device, and a C7-cesium atom gas cell temperature control is designed around it to reduce the impact of external temperature changes on its performance.

[0118] ⑤C16-beam 3 is the output of the C-frequency stabilized laser unit, with a wavelength of approximately 852nm.

[0119] Step 5: The D-acoustic-optic frequency shift unit outputs pump laser and probe laser.

[0120] Includes: ① The C16-beam 3 (1 beam of 852nm laser) input from the C frequency-stabilized laser source unit is focused by the D1-convex lens and then split into two laser beams after the D2-AOM acousto-optic frequency shift: D9-negative first-order light and D10-zero-order light.

[0121] ②The D9-negative-first order light passes through the D3-trapezoidal prism, the D13 / D15-45° total reflection mirror, and the D14-beam expander to form the D16-pump laser, which enters the A-cesium beam tube from the A4-pump region light window.

[0122] ③ After passing through the D5-transmitter mirror, the D10-zero order light is split into two laser beams: D11-zero order light 1 and D12-zero order light 2. D11-zero order light 1 passes through the D6-beam expander and the D4-45° total reflection mirror to form the D17 probe laser, which enters the A-cesium beam tube from the A11-probe region light field. D12-zero order light 2 enters the D7-photovoltaic cell, and the D8-AOM phase-locked loop frequency doubling power amplifier monitors the light intensity changes and automatically adjusts the power to stabilize the light intensity of the D10-zero order light, thereby stabilizing the light intensity of the D17-probe laser.

[0123] Step 6: The D16-pump laser interacts with cesium atoms to achieve atomic state preparation. The D16-pump laser is perpendicular to the direction of travel of the A3-cesium atom beam. It passes through the A4-pump region optical window and interacts with the A3-cesium atom beam to achieve electric dipole resonance, thereby emptying one of the hyperfine energy levels of the ground state of the cesium atom and achieving atomic state preparation.

[0124] Step 7: The E-crystal frequency locking unit realizes closed-loop locking of the laser-pumped miniature cesium atomic clock.

[0125] Includes: ①E3-Voltage Controlled Crystal Oscillator outputting one 10MHz signal.

[0126] ②The E4-discriminating amplifier circuit splits the 10MHz output into three 10MHz outputs: 10MHz_1, 10MHz_2, and 10MHz_3. 10MHz_1 and 10MHz_2 are used for the overall output; 10MHz_3 is output to the E5-9.2GHz microwave source circuit.

[0127] ③The E5-9.2GHz microwave source circuit multiplies the 10MHz to 9.2GHz through frequency doubling and synthesis, and feeds it into the A5-Ramsey cavity; the cesium atomic clock interacts with the 9.2GHz microwave to complete the microwave transition.

[0128] ④ The D17-probe laser is perpendicular to the A3-cesium atom beam travel direction, passes through the A11-probe region optical window and undergoes electric dipole resonance with cesium atoms, and outputs a fluorescence signal carrying frequency discrimination information through the A8-fluorescence collector.

[0129] ⑤ The fluorescence signal is amplified 106 times by the E1-weak signal amplifier circuit, and then the VCO of the voltage-controlled crystal oscillator is output through the E2-crystal frequency lock circuit to servo control the E3-voltage-controlled crystal oscillator, thereby realizing the closed-loop locking of the laser-pumped miniature cesium atomic clock.

[0130] Step 8: Under the control of the G-parameter adaptive tuning unit, the controlled parameters of the controlled modules are automatically adaptively tuned during the whole machine debugging process to form adaptive tuning parameter 1, so as to maintain the product's optimal working state.

[0131] Includes: The H-frequency stability tester is an external instrument independent of the laser-pumped miniature cesium atomic clock. It is used to test the frequency difference between the 10MHz output of the laser-pumped miniature cesium atomic clock and a reference 10MHz signal, and to calculate the relative frequency deviation. Allen's variance σ y (τ); It is connected to the internal computer of G2 via RS232 serial port. The "Frequency Stability Test Host Computer Software" is a self-developed host computer software used to receive the relative frequency deviation and Allan variance data obtained by the H frequency stability tester, run on the internal computer of G2, and display the results through the G3 display screen.

[0132] (1) Relative frequency deviation

[0133]

[0134] Where f is the output frequency of the laser-pumped miniature cesium atomic clock under test, and f0 is the reference frequency.

[0135] (2) Allen's variance

[0136] Allan variance is a time-domain stability analysis method. Suppose there is a relative frequency deviation data column {y} n The sampling interval is τ0, and m is the number of samples. The Allen variance based on the relative frequency deviation data can be expressed as:

[0137]

[0138] Where τ=mτ0 is the smoothing time; M′ is The number of, and Let be the mean of the m relative frequency deviation data within the i-th smoothing time τ, i.e.

[0139] Therefore, the controlled modules and controlled parameters during the debugging and optimization process are shown in Table 2 above. This section is used to solve "Technical Problem 3 in the Background Technology". The G1-main control unit collects and controls the controlled parameters of the controlled modules through the RS232 serial port. The "Frequency Stability Test Host Computer Software" iterates through the preset parameter list and changes the controlled parameters of the controlled modules. The "Frequency Stability Test Host Computer Software" selects the optimal operating parameters corresponding to the peak value through the "Parameter Peak Finding Difference Algorithm" to ensure that the whole machine works in the best state.

[0140] In this step, the parametric peak-finding difference algorithm is used to detect peaks by analyzing the changes in the first-order or higher-order differences of the data. The core idea is to utilize the trend characteristics of peaks closely related to data changes; for example, a change in the first-order difference from positive to negative may correspond to a peak, and a change from negative to positive may correspond to a trough. By calculating the difference between adjacent data points, combined with threshold judgment and trend analysis, the potential peak position is quickly located. The data range (sliding window / overall sample) M is set according to the actual situation, and the first-order difference sequence [M-1] within this range is calculated. Simultaneously, normalization is performed to calculate the mean within the range M. Given the standard mean square deviation S, the formula for calculating the normalized first-order difference sequence [M-1]' is:

[0141]

[0142] Among them, y i Using sample data and a specified threshold Z, the values ​​y' of the difference sequence are determined sequentially.i Check if the threshold Z has been checked to determine the location of the peak value.

[0143] It should be noted that, in this implementation, the cesium furnace operating temperature T is based on the B2-cesium furnace temperature control source. B2 Taking the automatic tuning process of [parameter name] as an example, the automatic tuning process of other controlled parameters is similar:

[0144] ①The overall stability index is related to the cesium atomic beam I that leaks from the collimator per unit time.

[0145] Under the condition of thin-walled orifice discharge, I is obtained from formula (1):

[0146]

[0147] Among them, A S Let be the cross-sectional area of ​​the collimator, and be a constant.

[0148] k is the collimator efficiency, which can be obtained from formula (2):

[0149]

[0150] n is the number of atoms per unit volume in the cesium bubble, which can be calculated using formulas (3) and (4), where T is the thermodynamic temperature and κ is a constant:

[0151]

[0152] P=nκT (7)

[0153] The average velocity of the atom is calculated using formula (5), where m is the mass of the cesium atom:

[0154]

[0155] According to formulas (1) to (5), the atomic beam I is closely related to the temperature T.

[0156] ② Tuning method: Under the control of the G1-main control unit, the temperature is traversed in the range of 100℃~130℃ in 5℃ increments. Each point is kept at the temperature for 2 hours. The host computer software automatically records the relative frequency deviation and Allan variance of each point.

[0157] Table 6. Temperature ergodic and relative frequency deviation, Allen's variance list

[0158]

[0159]

[0160] Using the "parameter-based peak-finding difference algorithm," the optimal relative frequency deviation is found, such as... Subsequently, under the control of the G1 main control unit, the cesium furnace temperature control temperature was set to... The corresponding cesium furnace operating temperature is 115℃. This completes the control of the cesium furnace operating temperature T of the B2-cesium furnace temperature control source. B2 Automatic tuning.

[0161] Step 9: Based on the adaptive tuning parameter 1 in step 8, under the control of the G parameter adaptive tuning unit, the fan speed of F2-temperature control fan and the secondary temperature control are automatically adaptively tuned during the high and low temperature operation of the whole machine, forming adaptive tuning parameter 2.

[0162] Based on the external environment of the entire machine, the fan speed V of the F2 temperature control fan is adaptively adjusted. F2 The operating temperature T of the C13 laser secondary temperature controller C13 This reduces the temperature gradient between different temperature control layers, thereby improving the temperature control effect. It also reduces the impact of ambient temperature on the laser, addressing "Technical Problem 1 in the Background Technology".

[0163] The specific implementation steps are as follows:

[0164] It adopts a three-layer temperature measurement and control system and can automatically adjust the "target" temperature according to the ambient temperature to achieve precise and efficient temperature control, thereby improving the environmental adaptability and long-term stability of the whole machine.

[0165] ① Primary temperature control: Based on the measurement of the F1-thermistor and the optimal operating temperature reference value of the whole machine, the G1-main control unit adaptively adjusts the speed of the F2-temperature control fan to reduce the drastic changes in internal temperature caused by changes in ambient temperature.

[0166] ② Secondary temperature control: Based on the difference between the internal temperature projected by the F1 thermistor and the optimal operating temperature of the device, the operating temperature T of the C13 laser secondary temperature controller is adaptively adjusted. C13 This creates a stable local temperature environment for sensitive devices. It avoids the problems of wide-range temperature control and reduced temperature control accuracy that arise from using a fixed target temperature, and improves the lifespan of the devices and the overall reliability of the system.

[0167] ③ Three-stage temperature control: C12 - laser tube temperature T of the laser control circuit C12 This achieves precise temperature control at the mK level, improving the long-term stability of the entire machine.

[0168] Step 10: Based on the adaptive tuning parameter 2 from step 9, the laser tube current, microwave power, etc. are adaptively tuned during long-term continuous operation under the control of the G-parameter adaptive tuning unit to form adaptive tuning parameter 3.

[0169] The controlled modules and parameters during long-term operation of the entire machine are shown in Table 3 above. Adjust the parameter status to ensure that the entire machine operates in the best condition. This section is used to solve technical problems 1, 2, and 4 in "I. Background Technology".

[0170] Based on the laser tube temperature T in the C12 laser control circuit C12 The laser tube current I is adaptively adjusted according to the change. C12 This is to reduce changes in light intensity, thereby improving long-term stability, and is used to solve "Technical Problem 2 in the Background Technology". Two important parameters of a laser are wavelength (frequency) and power. During operation, the laser is in a frequency-locked state. According to the technical manual of the laser used, the relationship between wavelength and temperature and current is as follows:

[0171]

[0172] According to formulas (9) and (10), the wavelength change caused by a temperature change of 1 mK is 20 times that caused by a current change of 1 μA.

[0173] During the operation of the entire machine, the laser tube current I of the C12-laser control circuit is utilized. C12 To stabilize the frequency, a certain threshold is set. When the current change exceeds this threshold, the laser tube temperature T of the C12 laser control circuit is adjusted. C12 The solution is to compensate for the change in current, i.e., the "temperature-compensated current" method.

[0174] During long-term operation of the product, the G1 main control unit monitors the frequency discrimination signal amplitude V of the E1 weak signal amplifier circuit. E1 When the signal is below the threshold, the product enters "unlocked holding mode," scanning the output frequency of the E5-9.2GHz microwave source circuit between 9192666770Hz and 9192681770Hz, while simultaneously adjusting the output power P of the E5-9.2GHz microwave source circuit. E5 This makes V E1 The settings requirements are met.

[0175] The monitoring modules and parameters during long-term operation of the whole machine are shown in Table 6 above. When the parameters are abnormal, the whole machine will alarm; depending on the severity of the alarm, the automatic shutdown process will be initiated.

[0176] This invention features adaptive parameter tuning, overcoming the shortcomings of laser-pumped cesium atomic clocks: To reduce the impact of ambient temperature on the laser, multi-layer temperature control is implemented, and the temperature control temperature of the outer layers can be adaptively tuned according to the ambient temperature, thereby reducing the temperature gradient between the layers and improving the temperature control effect; To reduce light intensity changes, the laser drive current can be adaptively tuned according to light intensity changes; Parameter adaptive tuning allows machines to replace manual optimization of laser, microwave, circuit, and atomic parameters, reducing labor costs; During operation, the microwave power and the operating point of the crystal oscillator frequency-locked servo circuit are automatically tuned, improving long-term stability.

[0177] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0178] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0179] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A kind of laser pumped cesium atomic beam clock parameter adaptive setting device, it is characterized in that, The cesium beam tube unit includes a atomic beam generation area, an atomic state preparation area, a microwave interaction area, and a transition detection area, and is used to realize the interaction of cesium atoms with lasers and microwaves. The cesium beam tube driving unit is connected to the cesium beam tube unit and includes an ion pump high-voltage source, a cesium furnace temperature control source, and a C-field constant current source, and is used to drive the cesium beam tube to work. The frequency-stabilized laser source unit includes a laser and a saturated absorption frequency stabilization optical path, and is used to output a frequency-stabilized laser. The acousto-optic frequency shift unit receives the frequency-stabilized laser, generates pump laser and probe laser through an acousto-optic frequency shifter, and includes an optical intensity stabilization control module. The crystal oscillator frequency locking unit includes a voltage-controlled crystal oscillator, a 9.2 GHz microwave source circuit, and a crystal oscillator frequency locking circuit, and is used to extract an error voltage carried by an atomic transition signal and feed back to the voltage-controlled crystal oscillator to realize closed-loop locking of the atomic hyperfine energy level transition spectrum to the voltage-controlled crystal oscillator. The temperature acquisition and control unit realizes cabinet temperature monitoring and preliminary regulation through a thermistor and a temperature control fan. The power supply unit is used to convert external input AC or DC voltage into multiple isolated DC voltages. The parameter self-adaptive setting unit includes a main control unit, an internal computer, and a display screen. The main control unit is connected to each controlled module through a communication interface, and the internal computer runs host computer software and is configured to: Collect the output signal and the reference signal of the whole machine through an external frequency stabilization tester, calculate the relative frequency deviation and the Allan variance, and obtain the frequency deviation sequence and the Allan variance data set; Based on the frequency deviation sequence and the Allan variance data set, perform a parameter peak-difference algorithm to determine the optimal working parameter combination corresponding to the peak value; In response to the optimal parameter combination and the environmental temperature data, the primary temperature control, the secondary temperature control, and the tertiary temperature control are executed in linkage, wherein the primary temperature control adjusts the fan speed to suppress environmental mutations, the secondary temperature control adjusts the laser temperature control target temperature to stabilize the local environment, and the tertiary temperature control compensates for the wavelength drift according to the temperature-current mapping relationship, thereby realizing temperature gradient compression and wavelength stability control; Compare the real-time monitoring parameters with the preset threshold to determine the alarm level, and trigger the system response instruction accordingly, wherein the response instruction includes operation maintenance, parameter recalibration, or automatic shutdown. The cesium beam tube unit includes:

2. The apparatus for adaptive setting of laser-pumped cesium atomic beam clock parameters according to claim 1, characterized in that, A cesium furnace, a collimating channel, a pumping area light window, a Ramsey cavity, a C-field coil, a double-layer magnetic shield, a fluorescence collector, a graphite block, an ion pump, and a detection area light window in the vacuum chamber; The cesium furnace is heated to 100℃, the cesium atom vapor passes through the collimating channel to form a cesium atomic beam, the cesium atomic beam passes through the pumping area light window into the atomic state preparation area in turn, and then enters the atomic and microwave interaction area composed of the Ramsey cavity, the C-field, and the magnetic shield, and finally reaches the detection area; The detection area light window allows the probe laser to interact with the cesium atomic beam, the fluorescence collector is used to collect the generated fluorescence signal, the graphite block is used to adsorb the completed cesium atomic beam, and the ion pump is used to maintain the high vacuum state in the entire cesium beam tube, ensuring that the beam diameter of the pumping light is equal to or greater than the diameter of the cesium atomic beam, so that the pumping light in the beam diameter region interacts with the cesium atomic beam. The optical intensity stabilization control module of the acousto-optic frequency shift unit includes:

3. The apparatus for adaptive setting of laser-pumped cesium atomic beam clock parameters according to claim 1, characterized in that, ​ ​ The catadioptric mirror splits the zero-order light into first zero-order light and second zero-order light, the photocell receives the second zero-order light, and the phase-locked frequency multiplication power amplifier dynamically adjusts the power according to the light intensity change to stabilize the detection laser intensity. The frequency stabilized laser is divided into pumping laser and detection laser after AOM acousto-optic frequency shift, and the beam diameter of the pumping laser is greater than or equal to the diameter of the rubidium atomic beam, so that the light beam interacts with the atomic beam.

4. The apparatus for adaptive setting of laser-pumped cesium atomic beam clock parameters according to claim 1, characterized in that, The frequency stabilized laser source unit comprises a two-stage temperature control structure: the laser two-stage temperature control covers the laser, and the cesium atom cell temperature control covers the cesium atom cell.

5. A method for adaptive setting of parameters of a laser-pumped cesium atomic beam clock, using the device for adaptive setting of parameters of a laser-pumped cesium atomic beam clock according to any one of claims 1 to 4, characterized in that, It comprises: Receive the relative frequency deviation and Allan variance data sent by the external frequency stabilization tester, wherein the calculation formula of the relative frequency deviation is as follows: In the formula, f is the output frequency of the measured laser pumped cesium atomic clock, and f0 is the reference frequency; The calculation formula of the Allan variance is as follows: where τ = mτ0is the smoothing time, M ′ is the number of is the mean of the m relative frequency deviations in the i-th smoothing time τ, i.e. is the mean of the m relative frequency deviations in the i-th smoothing time τ, i.e. where τ = mτ0is the smoothing time, M ′ is the number of is the mean of the m relative frequency deviations in the i-th smoothing time τ, i.e. is the mean of the m relative frequency deviations in the i-th smoothing time τ, i.e. Receive and analyze the relative frequency deviation and Allan variance data, traverse the controlled parameters of the controlled module according to the preset parameter list, and determine the Allan variance optimal value and the relative frequency deviation inflection point by using the peak difference algorithm. According to the Allan variance optimal value and the relative frequency deviation inflection point, adaptively perform parameter setting, which includes cesium furnace working temperature, C field current, laser two-stage temperature control working temperature, cesium atom cell working temperature, AOM drive power and 9.2GHz signal source output power, and select the optimal working parameters corresponding to the peak value.

6. The method of claim 5, wherein the parameters of the laser-pumped cesium atomic beam clock are self-tuned by, The adaptive parameter setting includes: The three-stage temperature measurement and control includes primary temperature control, secondary temperature control and tertiary temperature control, wherein the primary temperature control includes adaptively adjusting the speed of the temperature control fan according to the measurement of the thermistor and the reference value of the optimal working temperature of the whole machine, the secondary temperature control includes adaptively adjusting the working temperature of the laser two-stage temperature control according to the difference between the temperature displayed by the thermistor and the optimal working temperature of the device, and the tertiary temperature control includes precisely controlling the temperature of the laser tube of the laser control circuit to the order of mK.

7. The method of claim 6, wherein the parameters of the laser-pumped cesium atomic beam clock are self-tuned by, The tertiary temperature control includes: Compensate the wavelength drift according to the temperature-current mapping relationship, and then realize temperature gradient compression and wavelength stability control, wherein the temperature-current mapping relationship is the corresponding relationship between wavelength, current and temperature, and the calculation formula is as follows: In the formula, λ is the wavelength, I is the current, and T is the temperature.

8. The method of claim 6, wherein the parameters of the laser-pumped cesium atomic beam clock are self-tuned by, The adaptive adjustment of the working temperature of the laser two-stage temperature control includes: During the operation of the whole machine, adjust the current of the laser tube through the laser control circuit to realize frequency stabilization, set a preset threshold value, and judge whether the change amount of the current of the laser tube exceeds the threshold value, if yes, the system automatically adjusts the temperature of the laser tube in the laser control circuit to compensate for the change of the current, and if not, the system maintains the original parameters.

9. The method of claim 5, wherein the parameters of the laser-pumped cesium atomic beam clock are self-tuned by, The use of the peak difference algorithm to determine the Allan variance optimal value and the relative frequency deviation inflection point includes: Collect the key parameter data sequence in the system operation process; Apply the peak difference algorithm to the collected data sequence, calculate the first-order difference and perform normalization processing to identify the peak value position in the data, and the calculation formula is as follows: where y i is the sample data, is the mean, S is the standard deviation, y i ‘ is the value of the difference sequence; According to the peak value position identified by the peak difference algorithm, select the corresponding working parameters, and mark them as optimal working parameters.

10. The method of claim 5, wherein the parameters of the laser-pumped cesium atomic beam clock are self-tuned by, The receiving and analyzing relative frequency deviation and Allan variance data, the previous starting process includes: Starting the ion pump high voltage source to generate ion pump voltage, judging whether the state of the ion pump high voltage source is normal or not; If normal, starting the cesium furnace temperature control source, the laser secondary temperature control and the cesium atom gas chamber temperature control in turn, and gradually activating the temperature control unit; if not normal, continuing to detect the ion pump high voltage source; Starting the laser control circuit and the laser frequency stabilization circuit.

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