Dual-band optical-microwave atomic clock based on cesium atoms and implementation method thereof

Abstract

This invention discloses a dual-band optical-microwave atomic clock based on cesium atoms and its implementation method. This invention utilizes cesium atoms, currently used for defining the second, as quantum references for both the microwave and optical atomic clocks, realizing atomic clocks in both microwave and optical bands. The two bands can be switched arbitrarily and can be output simultaneously. Compared to optical lattice clocks and ion clocks, the optical clock based on hot cesium atoms does not require an ultrastable local oscillator and an ultracold atomic quantum reference, offering advantages such as small size and long-term continuous operation. Compared to traditional microwave-pumped miniature cesium clocks, applying the laser output from the optical clock to the pump and probe beams of the optically pumped miniature cesium clock reduces laser frequency noise, resulting in a microwave clock with higher frequency stability. This invention requires only one local oscillator laser source, featuring a simple structure, convenient operation, excellent performance, and low cost. This invention is highly practical, expanding the application range of cesium-based microwave atomic clocks and miniaturized high-performance optical frequency atomic clocks.

Description

Technical Field

[0001] This invention belongs to the field of atomic clock technology, specifically relating to a dual-band optical-microwave atomic clock based on a cesium atomic clock and its implementation method. Background Technology

[0002] Time and frequency are currently the most accurately measurable physical quantities, and atomic clocks, as high-precision instruments for time and frequency measurement, have important applications. For example, they are used for fundamental physics research through frequency comparison (verification of general relativity, detection of dark matter, detection of ultralight dark matter, and the variation of physical constants over time), the current and redefinition of the second, the establishment of quantum sensing networks, and time-frequency transmission. These wide-ranging applications have spurred the rapid development of atomic clock technology and types, from microwave clocks to optical clocks, and even nuclear clocks and pulsar astronomical clocks. Optical frequency comparisons have proven that optical lattice clocks and ion-optical clocks are currently the best-performing atomic clocks. Even so, scientists are still striving to enrich the types of atomic clocks, including high-ionization clocks, single-molecule ion clocks, molecular lattice clocks, hydrogen atom lattice clocks, mercury atom lattice clocks, indium ion clocks, and even naturally rare thorium-229 nuclear clocks and millisecond-wave pulsar astronomical clocks. The types of atomic clocks continue to emerge, used to explore the mysteries of nature, enrich human understanding, and especially expand the application scope of quantum precision measurement.

[0003] Although there are many types of atomic clocks, the cesium atomic microwave clock is currently the only one used to define the second. A roadmap for defining the second using optical clocks is expected to be finalized in 2026. Cesium atomic clocks, with their unique advantages, were first developed by the UK National Physical Laboratory in 1955, creating the world's first cesium-based atomic beam clock. Shortly after, in 1967, at the 13th General Conference on Weights and Measures, one second was defined at the hyperfine transition frequency of the cesium atom's ground state, making cesium the reference for first-order time measurement standards. Currently, the accuracy of microwave atomic clocks can no longer meet the needs of certain applications, and work on revising the definition of the second using optical clocks is in full swing. Optical lattice clocks and ion-optical clocks may become the reference clocks for the redefined second. However, since the three schemes for defining the second have not yet been finalized, and it is possible that microwave clocks and optical clocks will be developed simultaneously, with weights determined to achieve the transition and re-establishment of the second definition.

[0004] Therefore, finding a way to leverage the practical advantages of microwave clocks while also utilizing the performance advantages of optical clocks is a highly challenging yet widely applicable endeavor. Summary of the Invention

[0005] Due to their unique performance advantages, atomic clocks realized using cesium atoms as quantum references are of great significance. Unlike optical lattice clocks and ion clocks, optical clocks based on hot cesium atoms do not require ultrastable local oscillators and ultracold atomic quantum references, offering advantages such as small size, system simplicity, and long-term continuous operation. Since the optical frequency center transition frequency is much higher than that of microwaves, its short-term frequency stability is superior to microwave clocks, making it more suitable for the current demand for high-performance optical frequency standards. Furthermore, applying this small-volume, high-performance optical clock to the pump and probe beams of an optically pumped cesium clock can reduce laser frequency noise, thereby obtaining a high-performance microwave clock. In summary, this invention innovatively utilizes cesium atom quantum references to realize atomic clocks in two different bands: microwave and optical. The two bands can be switched at will or output simultaneously. The microwave atomic clock and the optical frequency atomic clock exhibit superior long-term and short-term frequency stability, respectively, realizing a dual-band optical-microwave atomic clock based on cesium atoms.

[0006] The technical problem to be solved by this invention is: how to provide a dual-band optical-microwave atomic clock based on cesium atoms, requiring that its technical solution be simple and reliable, the system be compact, simple in structure, easy to operate, and capable of arbitrarily switching between microwave and optical bands or outputting simultaneously, thereby expanding the application scope of practical microwave atomic clocks and miniaturized high-performance optical frequency atomic clocks based on cesium atoms.

[0007] To address the aforementioned technical problems, this invention provides a dual-band optical-microwave atomic clock based on a cesium atomic clock, comprising:

[0008] The local oscillator laser source 1 can be an external cavity semiconductor laser or a DBR laser, used to generate wavelengths corresponding to cesium atoms from 6S... 1 / 2 State to 6P 3 / 2 The local oscillator laser at a state transition frequency corresponding to 852nm;

[0009] The first half-wave plate 2 and the first polarizing beam splitter 3 are used to adjust the power of the reflected and transmitted light of the laser output from the local oscillator laser source 1 after passing through the first beam splitter 3. The reflected light after passing through the first polarizing beam splitter 3 is used for laser frequency stabilization, and the transmitted light after passing through the first polarizing beam splitter 3 is used for the next application.

[0010] The first reflecting mirror 4 is used to receive the 852nm wavelength local oscillator laser reflected from the polarizing beam splitter 3;

[0011] Modulation transfer spectrum stabilization system 5 is used to generate modulation transfer spectrum error signals, stabilize the local oscillator laser frequency, and lock the local oscillator laser frequency to cesium atom 6S. 1 / 2 (F=4) to 6P 3 / 2 At the hyperfine transition energy level of (F=5);

[0012] The second half-wave plate 6 and the second polarizing beam splitter 7 are used to adjust the power of the reflected and transmitted light of the laser output from the local oscillator laser source 1 after passing through the second polarizing beam splitter 7. The reflected light after passing through the first polarizing beam splitter 3 is used for laser frequency stabilization, and the transmitted light after passing through the first polarizing beam splitter 3 is used for the next application.

[0013] The second reflector 8 is used to beat the transmitted light of the laser output from the frequency-stabilized local oscillator laser source 1 after passing through the second beam splitter 7 with the Nth comb tooth of the optical frequency comb 9 whose frequency is closest to that of the laser. The beat frequency signal is output as a frequency standard signal.

[0014] An optical frequency comb 9 is used to downconvert the frequency of the laser output from the frequency-stabilized local oscillator laser source 1, where the laser frequency is f. L The beat frequency f is obtained by taking the beat frequency of a spectral component close to the frequency in the optical frequency comb 9, i.e., the Nth comb tooth. b Microwave phase-locked loop technology can strictly control the beat frequency f. b Given the initial frequency f0 of the optical comb, the repetition frequency f of the optical comb is... r with f b f L It is related to f0, and according to the working principle, f r The stability and accuracy are determined by the laser frequency f. L This decision enabled the high-precision transmission of optical frequencies to microwave frequencies, resulting in an optical atomic clock based on cesium atoms.

[0015] The third half-wave plate 10 and the third polarizing beam splitter 11 are used to adjust the power of the reflected light and transmitted light after passing through the third polarizing beam splitter 11.

[0016] The acousto-optic modulator 12 is used to shift the frequency of the laser output from the frequency-stabilized local oscillator laser source by 251MHz, which is then used as the pump light for the optically pumped cesium clock. The pump light frequency corresponds to the cesium atom 6S. 1 / 2 (F=4) to 6P 3 / 2 The hyperfine transition energy level (F=4) will bring the cesium atom's ground state 6S... 1 / 2 All atoms of (F=4) are pumped to 6S 1 / 2 (F=3);

[0017] The first total reflection mirror 13 is used to reflect the pump light along the original path to enhance the light pumping effect;

[0018] Cesium furnace 14 is used to provide a cesium atom beam;

[0019] Microwave resonant cavity 15 is used for the interaction between microwaves and cesium atoms;

[0020] Microwave source 16 is used to generate the Ramsey microwave excitation field to excite cesium atoms from their ground state 6S. 1 / 2 (F=3) Pumped to 6S 1 / 2 (F = 4);

[0021] The third reflecting mirror 17 is used to reflect the light reflected after passing through the third polarizing beam splitter 11, and use it as the detection light for the optically pumped cesium clock to detect the ground state 6S under the action of the Ramsey microwave excitation field. 1 / 2 Changes in the number of particles at (F=4);

[0022] The second total reflection mirror 18 is used to reflect the pump light along the original path to enhance the intensity of the probe light signal.

[0023] Detector 19 is used to detect the transition Ramsay lines of microwave atomic clocks;

[0024] The optical pumping cesium clock circuit 20 is used to lock the frequency of the microwave source 16, so that the microwave source 16 outputs an atomic clock signal to form a microwave atomic clock based on cesium atoms.

[0025] The initial frequency f0 of the optical frequency comb 9 can be locked to an external microwave source using microwave phase-locked loop technology, or it can be locked to the microwave atomic clock signal output by the optical pump cesium clock.

[0026] Furthermore, this invention also provides a method for implementing a dual-band optical-microwave atomic clock based on a cesium atomic clock, specifically including the following steps:

[0027] Step S1: The local oscillator laser source 1 locks the local oscillator laser frequency to the cesium atom 6S frequency through the modulation transfer spectrum stabilization system 5. 1 / 2 (F=4) to 6P 3 / 2 At the hyperfine transition energy level of (F=5);

[0028] Step S2: The frequency-stabilized local oscillator laser source 1 beats with the Nth comb tooth of the optical frequency comb 9, which has a frequency close to that of the comb tooth, to achieve optical frequency down-conversion. The beat frequency signal is a microwave signal and can be directly applied. The repetition frequency f of the optical frequency comb... r The stability and accuracy are determined by the frequency f of the stabilized local oscillator laser. L This decision enabled the high-precision transmission of optical frequencies to microwave frequencies, resulting in an optical atomic clock based on cesium atoms.

[0029] Step S3: The acousto-optic modulator 12 shifts the frequency of the laser output from the frequency-stabilized local oscillator laser source, with the frequency corresponding to the cesium atom 6S. 1 / 2 (F=4) to 6P 3 / 2The hyperfine transition energy level (F=4) is used as the pump light for optically pumping a small cesium clock, bringing the cesium atom's ground state 6S... 1 / 2 All atoms of (F=4) are pumped to 6S 1 / 2 (F=3);

[0030] Step S4: The cesium furnace 14 outputs a cesium atom beam, which interacts with the Ramsay microwave excitation field generated by the microwave source 16 in the microwave resonant cavity 15, causing the cesium atoms to move from the ground state 6S. 1 / 2 (F=3) Pumped to 6S 1 / 2 (F = 4);

[0031] Step S5: The laser output from the frequency-stabilized local oscillator laser source is used as the probe light for the optically pumped cesium clock to detect the ground state 6S under the action of the Ramsey microwave excitation field. 1 / 2 Changes in the number of particles at (F=4);

[0032] Step S6: The detector 19 detects the Ramsey spectral line of the clock transition, and locks the frequency of the microwave signal output by the microwave source 16 through the optical pump cesium clock circuit 20, so that the microwave source 16 outputs an atomic clock signal, forming a microwave atomic clock based on cesium atoms.

[0033] Compared with the prior art, the positive effects of the present invention are as follows:

[0034] This invention innovatively utilizes cesium atoms, currently used for defining seconds, as quantum references for both microwave and optical atomic clocks, realizing atomic clocks in two different wavelength bands. These two bands can be switched arbitrarily and can be output simultaneously. Compared to optical lattice clocks and ion clocks, the optical clock based on hot cesium atoms does not require an ultrastable local oscillator or ultracold atomic quantum reference, offering advantages such as small size, system simplicity, and long-term continuous operation. Compared to traditional microwave-pumped cesium clocks, applying the laser output from the optical clock to the pump and probe beams of the optically pumped cesium clock reduces laser frequency noise, resulting in a microwave clock with higher frequency stability. Furthermore, this invention requires only a single local oscillator laser source, featuring a simple structure, convenient operation, excellent performance, and low cost. It realizes a dual-band optical-microwave atomic clock based on cesium atoms, with the microwave atomic clock and optical frequency atomic clock exhibiting superior long-term and short-term frequency stability, respectively. This invention is highly practical and greatly expands the application scope of practical microwave atomic clocks and miniaturized high-performance optical frequency atomic clocks based on cesium atoms. Attached Figure Description

[0035] Figure 1 This invention provides a schematic diagram of a dual-band optical-microwave atomic clock based on a cesium atomic clock.

[0036] Figure 2This is a schematic diagram of the relevant cesium atom energy level structure during the implementation of this invention. Detailed Implementation

[0037] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0038] To address the problems of existing technologies, this invention provides a device for a dual-band optical-microwave atomic clock based on a cesium atomic clock, such as... Figure 1 As shown, the device includes:

[0039] Local oscillator laser source 1, external cavity semiconductor laser, or DBR laser, with an output wavelength of 852nm, corresponding to cesium atoms from 6S... 1 / 2 State to 6P 3 / 2 state;

[0040] The first half-wave plate 2 and the first polarizing beam splitter 3 are used to adjust the power of the reflected and transmitted light of the laser output from the local oscillator laser source 1 after passing through the first beam splitter 3. The transmitted light after passing through the first polarizing beam splitter 3 is used for laser frequency stabilization, and the reflected light after passing through the first polarizing beam splitter 3 is used for the next application.

[0041] The first reflecting mirror 4 is used to receive the 852nm wavelength local oscillator laser reflected from the polarizing beam splitter 3;

[0042] The modulation transfer spectrum stabilization system 5 is used to generate a modulation transfer spectrum error signal, stabilize the frequency of the local oscillator laser source 1, and lock the frequency of the local oscillator laser to the cesium atom 6S. 1 / 2 (F=4) to 6P 3 / 2 At the hyperfine transition energy level of (F=5);

[0043] The second half-wave plate 6 and the second polarizing beam splitter 7 are used to adjust the power of the reflected and transmitted light of the laser output from the local oscillator laser source 1 after passing through the second polarizing beam splitter 7. The transmitted light after passing through the first polarizing beam splitter 3 is used for laser frequency stabilization, and the reflected light after passing through the first polarizing beam splitter 3 is used for the next application.

[0044] The second reflector 8 is used to beat the transmitted light of the laser output from the frequency-stabilized local oscillator laser source 1 after passing through the second beam splitter 7 with the Nth comb tooth of the optical frequency comb 9, which has a frequency close to that of a comb tooth. The beat frequency signal is a microwave signal that can be directly applied, thereby realizing the high-precision transmission of optical frequency to microwave frequency and forming an optical atomic clock based on cesium atoms.

[0045] Optical frequency comb 9 is used to transmit the optical frequency output by the frequency stabilized local oscillator laser source 1 to the microwave frequency with high precision, forming an optical atomic clock based on cesium atoms;

[0046] The third half-wave plate 10 and the third polarizing beam splitter 11 are used to adjust the power of the reflected light and transmitted light after passing through the third polarizing beam splitter 11.

[0047] The acousto-optic modulator 12 is used to shift the frequency of the laser output from the frequency-stabilized local oscillator laser source by 251MHz. This shift is used as the pump light for the optically pumped cesium clock. The pump light power is in the mW range, and the pump light frequency corresponds to the 6S cesium atom. 1 / 2 (F=4) to 6P 3 / 2 The hyperfine transition energy level (F=4) will bring the cesium atom's ground state 6S... 1 / 2 All atoms of (F=4) are pumped to 6S 1 / 2 (F=3);

[0048] The first total reflection mirror 13 is used to reflect the pump light along the original path to enhance the light pumping effect;

[0049] Cesium furnace 14 is used to provide a cesium atomic beam, and the temperature of the cesium furnace is set at about 100°C;

[0050] Microwave resonant cavity 15 is used for the interaction between microwaves and cesium atoms;

[0051] Microwave source 16 is used to generate the Ramsey microwave excitation field at a frequency of 9.19 GHz, which is the hyperfine level spacing of the cesium atom's ground state, to drive the cesium atom from its ground state 6S... 1 / 2 (F=3) Pumped to 6S 1 / 2 (F = 4);

[0052] The third reflecting mirror 17 is used to reflect the light reflected after passing through the third polarizing beam splitter 11, and use it as the probe light for the optical pumping of the small cesium clock. Its power is less than that of the pump light, on the order of mW, and its frequency corresponds to the 6S atom of cesium. 1 / 2 (F=4) to 6P 3 / 2 Hyperfine transition energy level (F=45) was detected under Ramsey microwave excitation field to detect the ground state 6S 1 / 2 Changes in the number of particles at (F=4);

[0053] The second total reflection mirror 18 is used to reflect the pump light along the original path to enhance the intensity of the light detection signal.

[0054] Detector 19 is used to detect the clock transition Ramsay line;

[0055] The optical pumping cesium clock circuit 20 is used to lock the frequency of the microwave source 16, so that the microwave source 16 outputs an atomic clock signal to form a microwave atomic clock based on cesium atoms.

[0056] The initial frequency f0 of the optical frequency comb can be locked to an external microwave source using microwave phase-locked loop technology, or it can be locked to the microwave atomic clock signal output by the optical pump cesium clock.

[0057] Furthermore, the present invention also provides a method for implementing a dual-band optical-microwave atomic clock based on a cesium atomic clock. The method is implemented based on the aforementioned device and specifically includes the following steps:

[0058] Step S1: The local oscillator laser source 1 locks the local oscillator laser frequency to the cesium atom 6S frequency through the modulation transfer spectrum stabilization system 5. 1 / 2 (F=4) to 6P 3 / 2 At the hyperfine transition energy level of (F=5);

[0059] Step S2: The frequency-stabilized local oscillator laser source 1 beats with the Nth comb tooth of the optical frequency comb 9, which has a frequency close to that of the comb tooth, to achieve optical frequency down-conversion. The beat frequency signal is a microwave signal and can be directly applied. The repetition frequency f of the optical frequency comb... r The stability and accuracy are determined by the frequency f of the stabilized local oscillator laser. L This decision enabled the high-precision transmission of optical frequencies to microwave frequencies, resulting in an optical atomic clock based on cesium atoms.

[0060] Step S3: The acousto-optic modulator 12 shifts the frequency of the laser output from the frequency-stabilized local oscillator laser source by 251MHz, the frequency corresponding to the cesium atom 6S 1 / 2 (F=4) to 6P 3 / 2 The hyperfine transition energy level (F=4) is used as the pump light for optically pumping a small cesium clock, bringing the cesium atom's ground state 6S... 1 / 2 All atoms of (F=4) are pumped to 6S 1 / 2 (F=3);

[0061] Step S4: The cesium furnace 14 outputs a cesium atom beam, and the furnace temperature is controlled at around 100°C. In the microwave resonant cavity 15, the cesium atoms interact with the Ramsay microwave excitation field generated by the microwave source 16, causing the cesium atoms to move from their ground state 6S... 1 / 2 (F=3) Pumped to 6S 1 / 2 (F = 4);

[0062] Step S5: The laser output from the frequency-stabilized local oscillator laser source is used as the probe light for the optically pumped cesium clock, with a frequency corresponding to the 6S cesium atom. 1 / 2 (F=4) to 6P 3 / 2 Hyperfine transition energy level (F=5) was detected under Ramsey microwave excitation field to detect the ground state 6S 1 / 2 Changes in the number of particles at (F=4);

[0063] Step S6: The detector 19 detects the Ramsey spectral line of the clock transition, and locks the frequency of the microwave signal output by the microwave source 16 through the optical pump cesium clock circuit 20, so that the microwave source 16 outputs an atomic clock signal, forming a microwave atomic clock based on cesium atoms.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-band optical-microwave atomic clock based on cesium atoms, characterized in that, include: The local oscillator laser source (1) is used to generate a local oscillator laser with a wavelength corresponding to the transition frequency of the target transition energy level set in the cesium atom, which is incident on the first polarization beam splitter (3) through the first half-wave plate (2). The first half-wave plate (2) is used to adjust the power of the reflected and transmitted light after it is incident on the first polarizing beam splitter (3); The reflected light from the first polarizing beam splitter (3) is incident on the modulation transfer spectrum stabilization system (5) for laser frequency stabilization; the transmitted light from the first polarizing beam splitter (3) is incident on the second half-wave plate (6). The modulation transfer spectrum frequency stabilization system (5) is used to generate a modulation transfer spectrum error signal based on the received reflected light, stabilize the local oscillator laser frequency, and lock the local oscillator laser frequency to the first set hyperfine transition energy level in the target transition energy level. The second half-wave plate (6) is used to adjust the power of the reflected light and transmitted light after they are incident on the second polarizing beam splitter (7); the reflected light after passing through the second polarizing beam splitter (7) is incident on the third polarizing beam splitter (11) through the third half-wave plate (10), and the transmitted light after passing through the second polarizing beam splitter (7) is incident on the optical frequency comb (9), and beats the Nth comb tooth with the closest frequency in the optical frequency comb (9), and outputs the beat frequency signal as the frequency standard signal; The third half-wave plate (10) is used to adjust the power of the reflected and transmitted light after it is incident on the third polarization beam splitter (11); the transmitted light through the third polarization beam splitter (11) is incident on the acousto-optic modulator (12), and the reflected light through the third polarization beam splitter (11) is used as the probe light for the optical pumping of the small cesium clock and is incident on the second total reflection mirror (18). The probe light is used to detect the ground state 6S under the action of the Ramsey microwave excitation field. 1 / 2 The number of particles at F=4 changes; the transmitted light through the third polarizing beam splitter (11) is incident on the first total reflection mirror (13) via the acousto-optic modulator (12); the first total reflection mirror (13) is used to reflect the incident pump light along the original path to enhance the light pumping effect; An acousto-optic modulator (12) is used to shift the frequency of the incident laser to obtain the pump light of the optically pumped cesium clock, which is used to convert the cesium atom's ground state 6S 1 / 2 Atoms at F=4 are pumped to 6S 1 / 2 F=3; Cesium furnace (14) is used to provide a cesium atom beam into the microwave resonant cavity (15); A microwave resonant cavity (15) is used for the interaction between microwaves and cesium atoms; Microwave source (16) is used to provide Ramsey microwave excitation field for microwave resonant cavity (15) to expel cesium atoms from the ground state 6S 1 / 2 F=3 pumped to 6S 1 / 2 F=4; The second total reflection mirror (18) is used to reflect the probe light along the original path to enhance the intensity of the probe light signal. Detector (19) is used to detect the transition Ramsay lines of a microwave atomic clock; The optical pumping small cesium clock circuit (20) is used to lock the frequency of the microwave source (16) so that the microwave source (16) outputs an atomic clock signal to form a microwave atomic clock based on cesium atoms.

2. The dual-band optical-microwave atomic clock according to claim 1, characterized in that, When a microwave atomic clock is required, the initial frequency of the optical frequency comb (9) is... f 0 is locked to an external microwave source (16) using microwave phase-locked loop technology; when an optical atomic clock needs to be output, the initial frequency of the optical frequency comb (9) is set. f 0 is locked to the microwave atomic clock signal output by the optical pump cesium clock using microwave phase-locked loop technology; when it is necessary to output both the microwave atomic clock and the optical atomic clock simultaneously, the initial frequency of the optical frequency comb (9) is... f 0 is locked to the external microwave source (16) and the microwave atomic clock signal output by the optical pump cesium clock respectively through microwave phase-locked loop technology.

3. The dual-band optical-microwave atomic clock according to claim 1 or 2, characterized in that, The reflected light from the first polarizing beam splitter (3) is incident on the modulation transfer spectrum stabilization system (5) via the first reflecting mirror (4); the transmitted light from the second polarizing beam splitter (7) is incident on the optical frequency comb (9) via the second reflecting mirror (8); and the reflected light from the third polarizing beam splitter (11) is incident on the second total reflection mirror (18) via the third reflecting mirror (17).

4. The dual-band optical-microwave atomic clock according to claim 1 or 2, characterized in that, The target transition level is 6S. 1 / 2 State to 6P 3 / 2 State transition energy level.

5. The dual-band optical-microwave atomic clock according to claim 4, characterized in that, The frequency of the pump light corresponds to the second set hyperfine transition level in the target transition level; the second set hyperfine transition level is greater than the first set hyperfine transition level.

6. The dual-band optical-microwave atomic clock according to claim 5, characterized in that, The first setting of the hyperfine transition energy level is 6S. 1 / 2 F=4 hyperfine level to 6P 3 / 2 The hyperfine transition energy level of the F=5 hyperfine level, and the second set hyperfine transition energy level is 6S. 1 / 2 F=4 hyperfine level up to 6P 3 / 2 F=4 is the transition level of the hyperfine level.

7. A method for implementing the dual-band optical-microwave atomic clock according to claim 1, comprising the following steps: 1) The local oscillator laser source (1) locks the frequency of the output local oscillator laser through the modulation transfer spectrum frequency stabilization system (5), and locks the frequency of the local oscillator laser to the first set hyperfine transition energy level of the cesium atom target transition energy level; 2) The local oscillator laser source (1) after frequency stabilization beats the Nth comb tooth in the optical frequency comb (9) with the closest frequency to achieve optical frequency down-conversion and generate a beat frequency signal as a frequency standard signal output. 3) The acousto-optic modulator (12) shifts the frequency of the laser output from the frequency-stabilized local oscillator laser source as the pump light for the optically pumped cesium clock, thereby shifting the cesium atom to its ground state 6S. 1 / 2 Atoms at F=4 are pumped to 6S 1 / 2 F=3; 4) The cesium atom beam output from the cesium furnace (14) is injected into the microwave resonant cavity (15), so that the cesium atoms interact with the Ramsay microwave excitation field generated by the microwave source (16), and the cesium atoms are moved from the ground state 6S 1 / 2 F=4 pumped to 6S 1 / 2 F=3; 5) The laser output from the frequency-stabilized local oscillator laser source is used as the probe light for an optically pumped cesium clock to detect the ground state 6S under the action of the Ramsey microwave excitation field. 1 / 2 The change in the number of particles at F=4; 6) The transition Ramsay spectral line of the microwave atomic clock is detected by the detector (19). The frequency of the microwave signal output by the microwave source (16) is locked by the optical pump small cesium clock circuit (20), so that the microwave source (16) outputs the atomic clock signal, forming a microwave atomic clock based on cesium atoms.

8. The method according to claim 7, characterized in that, When a microwave atomic clock is required, the initial frequency of the optical frequency comb (9) is... f 0 is locked to an external microwave source (16) using microwave phase-locked loop technology; when an optical atomic clock needs to be output, the initial frequency of the optical frequency comb (9) is set. f 0 is locked to the microwave atomic clock signal output by the optical pump cesium clock using microwave phase-locked loop technology; when it is necessary to output both the microwave atomic clock and the optical atomic clock simultaneously, the initial frequency of the optical frequency comb (9) is... f 0 is locked to the external microwave source (16) and the microwave atomic clock signal output by the optical pump cesium clock respectively through microwave phase-locked loop technology.

9. The method according to claim 7, characterized in that, The target transition level is 6S. 1 / 2 State to 6P 3 / 2 The pump light frequency corresponds to the second predetermined hyperfine transition level in the target transition level; the first predetermined hyperfine transition level is 6S. 1 / 2 F=4 hyperfine level to 6P 3 / 2 F=5 is the hyperfine transition level of the hyperfine level, and the second set hyperfine transition level is 6S. 1 / 2 F=4 hyperfine level up to 6P 3 / 2 F=4 is the transition level of the hyperfine level.

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