Microwave calibration detection system and method based on Rydberg atoms

Abstract

The invention discloses a microwave calibration detection system and method based on Rydberg atoms, and belongs to the field of quantum precision measurement. According to the method, traceable quantitative microwave continuous detection is realized in a time-sharing or simultaneous acting mode by utilizing narrow linewidth laser and an optical frequency comb generated by the narrow linewidth laser. The invention provides a brand new technical approach for receiving and synchronous quantitative detection of continuous / pulse microwave signals, provides a new solution idea for configuration of a detection light source of a Rydberg atom microwave enhanced sensing technology, and lays a technical foundation for application of the technology in the fields of spatial spectrum sensing, electronic reconnaissance and the like.

Description

Technical Field

[0001] The present invention relates to a microwave calibration detection system and method based on Rydberg atoms, belonging to the technical field of quantum precision measurement. Background Art

[0002] The Rydberg atom microwave electric field sensor belongs to the technology of quantum precision measurement. This technology uses two laser beams, a probe laser and a coupling laser, to prepare alkali metal atoms into Rydberg states. The perturbation of the Rydberg state atoms by the microwave electric field to be measured is read out through the transmission spectrum of the probe laser. This method can achieve traceable measurement of the microwave electric field through the EIT-AT splitting transmission spectrum, but it cannot achieve high-sensitivity detection and receiver functions. Moreover, the transmission spectrum is usually obtained by scanning the laser frequency, which takes a long time and has poor stability, making it difficult to effectively measure transient signals. In order to achieve high-sensitivity detection of electromagnetic wave-loaded signals, an external local oscillator microwave field is usually used to construct an atomic superheterodyne detection architecture. Compared with traditional microwave measurement methods, the microwave electric field measurement technology based on Rydberg atoms has the technical potential for high-sensitivity detection. However, since the frequency of the probe laser needs to be locked when using the superheterodyne method, real-time EIT spectral information cannot be obtained, so the intensity calibration of the signal to be measured cannot be traced. To sum up, the existing technical means of the microwave enhanced sensing technology based on Rydberg atoms cannot achieve high-sensitivity traceable calibration detection of microwave signals, so the above two advantages are often not available at the same time. Summary of the Invention

[0003] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, a microwave calibration detection system and method based on Rydberg atoms are proposed, which are applicable to the measurement of continuous signals or transient signals, and high sensitivity and traceable quantitative measurement can be achieved simultaneously during the measurement process.

[0004] The technical solution of the present invention is:

[0005] A microwave calibration detection system based on Rydberg atoms, comprising a coupling light system, a probe light system and an atomic probe system;

[0006] The probe light system splits a single-frequency laser into two parts for separate processing: one laser beam is a DC component, which is used to pump ground-state alkali metal atoms to an intermediate energy level and extract microwave signals; the other laser beam is a pulse component, which is frequency-shifted and modulated to form an optical frequency comb for detecting the transmission spectrum of the probe light. Then the two laser beams are combined to form a probe laser and emitted to the atomic probe system;

[0007] The atomic probe system includes an atomic gas cell and a detector; wherein, the atomic gas cell is filled with alkali metal atoms and buffer gas, which is used to prepare the Rydberg atomic state, and the Rydberg atomic state atoms sense the microwave electric field to be measured; the detector collects the probe laser after the action of the atomic gas cell to realize the measurement of the perturbation of the Rydberg state atoms by the microwave electric field to be measured.

[0008] The coupling optical system emits coupling laser to the atomic gas cell, and the wavelength of the coupling laser is the wavelength corresponding to preparing the intermediate energy level of the alkali metal atoms to the Rydberg atomic state energy level.

[0009] Further, the probe optical system includes a single-frequency laser, a beam splitter, an acousto-optic modulator AOM, an electro-optic modulator EOM and a beam combiner;

[0010] The single-frequency laser emits single-frequency laser, and the center frequency of the single-frequency laser is aligned or locked to the D2 line of the alkali metal atoms;

[0011] The beam splitter divides the beam of the single-frequency laser into two parts, one is the laser A with a DC component, and the other is the laser B with a pulse component;

[0012] The acousto-optic modulator AOM performs a frequency shift processing on the laser B, and the frequency shift amount is greater than 5 MHz;

[0013] The electro-optic modulator EOM modulates the laser output by the acousto-optic modulator AOM to form an optical frequency comb;

[0014] The beam combiner combines the optical frequency comb output by the electro-optic modulator EOM and the laser A to form a probe laser and inject it into the atomic gas cell.

[0015] Further, the electro-optic modulator EOM is driven by a waveform generator AWG to modulate the laser output by the acousto-optic modulator AOM to form an optical frequency comb. Specifically:

[0016]

[0017] where ω c is the carrier frequency, V π is the half-wave voltage of the electro-optic modulator EOM, and f(t) is the waveform function generated by the waveform generator AWG.

[0018] Further, the waveform function generated by the waveform generator AWG is preferably a repetitive chirped sine curve. Specifically:

[0019]

[0020] where V0 is the modulation voltage amplitude, f0 and f1 are the starting frequency and the ending frequency of the sine curve respectively, and f c is the frequency interval between the comb teeth.

[0021] Furthermore, the frequency span of the optical frequency comb teeth formed by the electro-optic modulator EOM is not greater than 100 MHz.

[0022] Furthermore, the atomic gas cell is filled with alkali metal atoms and buffer gas. The alkali metal atoms are K, Rb or Cs, and the buffer gas is N2 or He.

[0023] A method for calibrating the microwave electric field strength using a microwave calibration detection system based on Rydberg atoms includes:

[0024] The probe light system emits probe laser light, and the coupling light system emits coupling laser light. The two laser beams are coaxially incident into the atomic gas cell and propagate in opposite directions in the atomic gas cell;

[0025] The DC component in the probe laser continuously pumps the ground state alkali metal atoms to the intermediate energy level; the coupling laser prepares the alkali metal atoms from the intermediate energy level to the Rydberg atomic state energy level;

[0026] The resonance microwave signal acting on the transition of the alkali metal Rydberg atomic state is fed into the microwave antenna, and the emission direction is aligned with the atomic gas cell. The resonant microwave field causes the atomic EIT signal to undergo EIT-AT splitting;

[0027] The optical frequency comb is modulated by the EIT-AT spectrum, and then beat with the DC component in the probe laser to project the spectral characteristics into the radio frequency domain. After being collected by the detector, it is viewed through a spectrum analyzer to achieve microwave electric field strength calibration.

[0028] A method for microwave reception using a microwave calibration detection system based on Rydberg atoms includes:

[0029] The probe light system emits probe laser light, and the coupling light system emits coupling laser light. The two laser beams are coaxially incident into the atomic gas cell and propagate in opposite directions in the atomic gas cell;

[0030] The DC component in the probe laser contains the difference frequency between the local oscillator microwave and the microwave to be measured in the frequency domain, and continuously pumps the ground state alkali metal atoms to the intermediate energy level; the coupling laser prepares the alkali metal atoms from the intermediate energy level to the Rydberg atomic state energy level;

[0031] The resonance microwave signal acting on the transition of the alkali metal Rydberg atomic state is fed into the microwave antenna, and the emission direction is aligned with the atomic gas cell. The resonant microwave field causes the atomic EIT signal to undergo EIT-AT splitting;

[0032] The optical frequency comb is modulated by the EIT-AT spectrum and then beat with the DC component in the probe laser;

[0033] The signal after beat frequency processing passes through a high-pass filter to remove the influence introduced by the difference frequency, and a spectrum analyzer is used to read out the heterodyne beat frequency microwave comb signal. The comb-shaped peaks shown reflect the atomic spectral characteristics, realizing the absolute intensity measurement of the microwave electric field to be measured.

[0034] The optoelectronic signal after beat frequency processing passes through a low-pass filter to obtain a difference frequency signal, thereby realizing the reception of the baseband signal.

[0035] Furthermore, the local oscillator microwave frequency is detuned from the microwave frequency to be measured by 150 kHz.

[0036] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

[0037] The advantages of the present invention compared with the prior art are as follows:

[0038] (1) The present invention uses the heterodyne method to synchronously realize the quantitative measurement of EIT-AT spectrum and the superheterodyne high-sensitivity reception, organically combining the two methods, which not only ensures the sensitivity of the system to the detection of microwave electric field, but also ensures the traceable quantitative measurement of the signal intensity.

[0039] (2) The present invention detects the transmission spectrum in the way of forming an optical frequency comb with a single light source, simplifies the complexity of the optical system, and reduces the parameter index requirements of the equipment in terms of tuning.

[0040] (3) The present invention uses the optical frequency comb heterodyne spectroscopy detection means to down-convert the signal in the optical frequency domain to the radio frequency domain, reducing the requirements and costs of the detection system.

[0041] (4) The present invention avoids the mechanical scanning technical approach of the traditional spectral detection scheme, and uses an optical frequency comb to realize high-speed spectral detection, which can be used for the detection of transient signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0043] Figure 1 is a schematic diagram of the microwave calibration detection system based on Rydberg atoms of the present invention;

[0044] Figure 2 is an energy level schematic diagram of the detection based on Rydberg atoms of the present invention;

[0045] Figure 3Schematic diagram of the strong-field metrology calibration scenario device according to an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of the microwave receiver application scenario device according to an embodiment of the present invention;

[0047] Figure 5 Design diagram of the detuning between the local oscillator microwave frequency and the microwave frequency to be measured according to an embodiment of the present invention;

[0048] Figure 6 Schematic diagram of the generation of the beat-frequency microwave comb signal according to an embodiment of the present invention. (a) is the optical frequency domain characteristic diagram of the probe laser pulse component, and (b) is the radio frequency domain characteristic diagram of the photodetector. Detailed implementation manners

[0049] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0050] The present invention proposes a microwave calibration detection system based on Rydberg atoms, as Figure 1 shown, including a coupling optical system, a probe optical system, and an atomic sensing system.

[0051] The probe optical system is used to prepare atoms from a low energy state to an intermediate energy state, and at the same time, as a detection signal, it records the perturbation of the microwave electric field on the atoms in the form of a change in light intensity through a photodetector.

[0052] Among them:

[0053] The light source of the probe optical system uses a single-frequency laser, and the center frequency is aligned or locked to the D2 line of alkali metal atoms. The single-frequency laser can adopt a commercial DFB or DBR laser, or a PDH or self-injection locked ultra-narrow linewidth laser scheme. After the laser polarization output, the light beam is split into two by a beam splitter such as a PBS. One of them is used as the single-frequency probe laser, denoted as probe laser A, which is a DC component, and the other is used as the pump light source of the optical frequency comb, denoted as probe laser B, which is a pulse component.

[0054] Taking the atomic microwave sensing system based on Cs atoms as an example, probe laser A is locked to the D2 line by means of saturated absorption spectroscopy or modulation transfer spectroscopy, with a center wavelength of 852 nm, and is used to pump the ground-state alkali metal atoms to 6P 3 / 2Energy levels are also used for the extraction of microwave signals. The probing laser B is frequency-shifted by an acousto-optic modulator (AOM) with a frequency shift greater than 5 MHz, and then forms an optical frequency comb through electro-optic modulator (EOM) modulation for the detection of the probing light transmission spectrum. Among them, the EOM is driven by an AWG to modulate the laser phase. The waveform function generated by the AWG preferably adopts a repetitive chirped sine curve, and the specific form is:

[0055]

[0056] where: V0 is the amplitude of the modulation voltage, f0 and f1 are the starting and ending frequencies of the sine wave respectively, and f c is the frequency interval between adjacent teeth. The corresponding optical modulation applied to the EOM is:

[0057]

[0058] where, ω c is the carrier frequency, and V π is the half-wave voltage of the EOM. It is preferred to use a low driving voltage. In this case, although the intensity of the central peak of the comb teeth is relatively high, it ensures relatively constant power for other comb tooth lines, thereby generating a uniform profile. To ensure the spectral resolution, it is preferred to control the repetition frequency within 100 kHz, ensure that the frequency span of the comb teeth is 100 MHz, and optimize the flatness of the spectrum.

[0059] Through the above steps, the probing laser A achieves frequency locking, and the probing laser B achieves the preparation of an optical frequency comb. Then, the two lasers are combined through components such as PBS and uniformly incident into the atomic gas cell

[0060] The coupling optical system is used to prepare atoms from the intermediate energy state to the Rydberg atomic state (n≥50). The coupling laser is a narrow-linewidth single-frequency laser, and the laser wavelength is the wavelength corresponding to the energy level from the P3 / 2 energy level of the alkali metal atom to the Rydberg atomic state energy level. For Cs atoms, if the 55D 5 / 2 state is selected, the coupling laser wavelength is 509.31 nm, and the laser frequency is locked through EIT spectroscopy frequency stabilization.

[0061] The atomic sensing system includes an atomic cell and a detector. The atomic cell is the place where light interacts with atoms to prepare Rydberg atomic states and is also the place where light interacts with microwaves. The atomic cell is filled with an alkali metal element and a buffer gas. Preferably, a single isotope of alkali metal (such as K, Rb, Cs, etc.) is filled, and the buffer gas is preferably gases such as N2, He, etc. In the embodiments, Cs atoms are taken as an example uniformly. The coupling laser and the probe laser are incident on the atomic cell in opposite directions, and the two lasers are precisely coaxially adjusted. After the probe laser passes through the atomic cell, it passes through a dichroic mirror (fully transparent at 852 nm and fully reflective at 509 nm), and the detector collects the signal. The collected data contains both the microwave electric field signal acting on the atomic cell and the atomic EIT spectrum signal, that is, the signal for calibrating the microwave electric field strength.

[0062] The usage method is specifically described through two scenarios: strong field metrology calibration and microwave reception.

[0063] For the application of strong field metrology calibration:

[0064] Taking Cs atoms as an example, as Figure 2 shown, the ground state (energy level |1>) is the 6S 1 / 2 energy level of cesium atoms, the first excited state (energy level |2>) is the 6P 3 / 2 energy level of cesium atoms, the first Rydberg state (energy level |3>) is the 47D 5 / 2 energy level of cesium atoms, the second Rydberg state (energy level |4>) is the 48P 3 / 2 energy level of cesium atoms, and the signal microwave field E sig acts on the 47D 5 / 2 →48P 3 / 2 transition, and the resonance frequency corresponding to this transition is 6.9377 GHz.

[0065] The probe laser B, that is, the pulsed output component in the probe laser, is generated by the following process, as Figure 3 shown: First, through an acousto-optic modulator (AOM), the first-order output is intercepted and its frequency is shifted by 200 MHz, and then an optical frequency comb is formed through an EOM. After the probe laser A is frequency stabilized by saturated absorption spectroscopy or modulation transfer spectroscopy, it is combined with the probe laser B to form the probe laser, and the probe laser and the coupling laser are transmitted in opposite directions in the alkali metal atomic cell. The cell is cylindrical, preferably with a diameter of 2.5 cm and a length of 40 mm. For the corresponding 47D 5 / 2 →48P 3 / 2The resonant microwave signal of the transition is fed into a microwave antenna, and the emission direction is aligned with the atomic gas cell. The resonant microwave field causes the EIT signal of the atoms to undergo EIT-AT splitting. At this time, the A component of the probe laser continuously excites the |1> atoms to the |2> state. After the probe laser B (the pulsed component of the probe laser) passes through the gas cell, the optical frequency comb is modulated by the EIT-AT spectrum. After beating with the A component of the probe laser, the spectral characteristics are projected into the radio frequency domain. The signal can be viewed through a spectrum analyzer after being detected by a photodetector, or can be viewed through Fourier transform after being collected in the time domain.

[0066] For microwave receiver applications, such as Figure 4 shown:

[0067] To improve the sensitivity of microwave detection, an atomic superheterodyne measurement method is usually adopted. The core difference of this method compared with the EIT-AT detection method is the introduction of a controllable local oscillator microwave field. When the unknown signal microwave field to be measured and the local oscillator microwave field act on the same Rydberg atoms simultaneously, the two are coherently superposed. Through the nonlinear response of the EIT spectrum, the beat frequency signal of the two can be obtained in the transmitted signal of the probe light. Using the above-mentioned probe light configuration, the A component and the B component of the probe light are combined and then injected into the atomic gas cell. The A component of the probe light mainly contains the difference frequency between the local oscillator microwave and the microwave to be measured, that is, the intermediate frequency component, in the frequency domain. The preferred local oscillator microwave frequency is detuned from the microwave frequency to be measured by 150 kHz, as Figure 5 shown. The specific value is optimized based on the highest sensitivity of the microwave detection to be measured. The pulsed output component is generated by the following process: First, through an acousto-optic modulator (AOM), the first-order output is intercepted and its frequency is shifted by 200 MHz, and then an optical frequency comb is formed through an EOM, as Figure 6 shown in (a) of. The optical frequency comb part and the CW part are combined to form the probe laser. The probe laser and the coupling laser propagate in opposite directions in the alkali metal atomic gas cell. The gas cell is cylindrical, preferably with a diameter of 2.5 cm and a length of 40 mm. The atomic gas cell is filled with cesium atoms and is sealed with glass. The two components in the probe light beat after passing through the vapor cell. A high-speed photodetector with a bandwidth of 300 MHz is used to remove the influence introduced by the intermediate frequency signal through a high-pass filter, and the beat frequency microwave comb signal is read out using a spectrum analyzer. The comb-shaped peaks shown can reflect the atomic spectral characteristics, as Figure 6As shown in (b) of the figure. Therefore, the optoelectronic signal received by the photodetector contains two parts, namely, the intermediate-frequency signal of the local oscillator microwave and the microwave to be measured in the probe light A component in the atomic superheterodyne scheme and the EIT-AT spectral signal. The two parts of the signal are respectively in the frequency bands of 150 kHz and 100 MHz - 300 MHz. The intermediate-frequency signal of the microwave to be measured can be obtained by low-pass filtering the photodetector signal. The high-pass filtered signal can obtain the EIT-AT spectral information through a spectrum analyzer or after acquisition and Fourier transform, so as to realize traceable quantitative measurement of the microwave intensity. At this time, the obtained EIT-AT spectrum is mainly the information of the local oscillator microwave. This spectral information can be used for closed-loop feedback control of parameters such as the intensity and frequency of the local oscillator microwave. If it is necessary to quantitatively measure the signal microwave field strength, the local oscillator microwave signal source can be briefly turned off, and the absolute intensity measurement of the microwave to be measured can be realized by using the "time-division multiplexing" method. The measurement process is the same as that described in the "high-field metrology calibration application".

[0068] The present invention organically combines the traditional atomic superheterodyne microwave detection technology with the EIT-AT spectral detection technology, integrates the advantages of traceable measurement and high-sensitivity detection and reception, improves the microwave electric field detection ability of the Rydberg microwave sensing technology, broadens its application scenarios, makes it have more obvious advantages compared with conventional means, and lays a technical foundation for its application in fields such as space spectrum sensing.

[0069] The above-described embodiments are only relatively preferred specific embodiments of the present invention. The general changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A microwave calibration detection system based on Rydberg atoms, characterized in that, It includes a coupling optical system, a probe optical system and an atomic probe system; The probe optical system splits a single-frequency laser into two parts for separate processing: one laser beam is a DC component, which is used to pump ground-state alkali metal atoms to an intermediate energy level and extract microwave signals; the other laser beam is a pulse component, which is processed by frequency shift modulation to form an optical frequency comb for detecting the transmission spectrum of the probe light; then the two laser beams are combined to form a probe laser and emitted to the atomic probe system; The atomic probe system includes an atomic gas cell and a detector; among them, the atomic gas cell is filled with alkali metal atoms and buffer gas, which is used to prepare Rydberg atomic states, and the obtained Rydberg atomic state atoms sense the microwave electric field to be measured; the detector collects the probe laser after the action of the atomic gas cell to realize the perturbation measurement of the Rydberg state atoms by the microwave electric field to be measured; The coupling optical system emits coupling laser to the atomic gas cell, and the wavelength of the coupling laser is the wavelength corresponding to preparing the intermediate energy level of alkali metal atoms to the Rydberg atomic state energy level.

2. The microwave calibration detection system based on Rydberg atoms according to claim 1, wherein The probe optical system includes a single-frequency laser, a beam splitter, an acousto-optic modulator AOM, an electro-optic modulator EOM and a combiner; The single-frequency laser emits single-frequency laser, and the center frequency of the single-frequency laser is aligned or locked to the D2 line of alkali metal atoms; The beam splitter splits the beam of the single-frequency laser into two parts, one is laser A with a DC component, and the other is laser B with a pulse component; The acousto-optic modulator AOM performs frequency shift processing on laser B, and the frequency shift amount is greater than 5 MHz; The electro-optic modulator EOM modulates the laser output by the acousto-optic modulator AOM to form an optical frequency comb; The combiner combines the optical frequency comb output by the electro-optic modulator EOM with laser A to form a probe laser and incident it into the atomic gas cell.

3. The microwave calibration detection system based on Rydberg atoms according to claim 2, characterized in that, The electro-optic modulator EOM is driven by a waveform generator AWG to modulate the laser output by the acousto-optic modulator AOM to form an optical frequency comb. Specifically: where ω c is the carrier frequency, V π is the half-wave voltage of the electro-optic modulator EOM, and f(t) is the waveform function generated by the waveform generator AWG.

4. The microwave calibration detection system based on Rydberg atoms according to claim 3, characterized in that, The waveform function generated by the waveform generator AWG is preferably a repeated chirped sine curve. Specifically: Wherein, V0 is the amplitude of the modulated voltage, f0 and f1 are respectively the starting frequency and the ending frequency of the sine curve, and f c is the frequency interval between the teeth of the comb.

5. The microwave calibration detection system based on Rydberg atoms according to claim 3, characterized in that, The frequency span of the comb teeth of the optical frequency comb formed by the electro-optic modulator EOM is not greater than 100 MHz.

6. The microwave calibration detection system based on Rydberg atoms according to claim 1, characterized in that, The atomic gas cell is filled with alkali metal atoms and buffer gas.

7. A method for calibrating microwave electric field intensity using a microwave calibration detection system based on Rydberg atoms as described in claim 1, characterized in that, It includes: The probe optical system emits a probe laser, and the coupling optical system emits a coupling laser. The two laser beams are coaxially incident into the atomic gas cell and propagate in opposite directions in the atomic gas cell; The DC component in the probe laser continuously pumps the ground-state alkali metal atoms to the intermediate energy level; the coupling laser prepares the alkali metal atoms from the intermediate energy level to the Rydberg atomic state energy level; The resonance microwave signal acting on the Rydberg atomic state transition of alkali metal atoms is fed into a microwave antenna, and the emission direction is aligned with the atomic gas cell. The resonant microwave field causes the EIT signal of the atoms to undergo EIT-AT splitting; The optical frequency comb is modulated by the EIT-AT spectrum, and then beat with the DC component in the probe laser to project the spectral characteristics into the radio frequency domain. After being collected by the detector, it is viewed through a spectrum analyzer to realize the calibration of the microwave electric field strength.

8. A method for microwave reception using a microwave calibration detection system based on Rydberg atoms as described in claim 1, characterized in that, It includes: The probe optical system emits a probe laser, and the coupling optical system emits a coupling laser. The two laser beams are coaxially incident into the atomic gas cell and propagate in opposite directions in the atomic gas cell; The DC component in the probing laser contains the difference frequency between the local oscillator microwave and the microwave to be measured in the frequency domain, and continuously pumps the ground-state alkali metal atoms to the intermediate energy level; the coupling laser prepares the alkali metal atoms from the intermediate energy level to the Rydberg atomic state energy level; The resonance microwave signal acting on the transition of the alkali metal Rydberg atomic state is fed into the microwave antenna, and the emission direction is aligned with the atomic gas cell, and the resonant microwave field causes the EIT signal of the atoms to undergo EIT-AT splitting; The optical frequency comb is modulated by the EIT-AT spectrum and then heterodyned with the DC component in the probing laser; The signal after the heterodyne processing passes through a high-pass filter to remove the influence introduced by the difference frequency, and the heterodyne microwave comb signal is read out using a spectrum analyzer. The comb-shaped peaks shown reflect the atomic spectral characteristics, realizing the absolute intensity measurement of the microwave electric field to be measured; The optoelectronic signal after the heterodyne processing passes through a low-pass filter to obtain a difference frequency signal, thereby realizing the reception of the baseband signal.

9. The method for microwave reception according to claim 8, wherein The local oscillator microwave frequency is detuned from the microwave frequency to be measured by 150 kHz.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 8 to 9.

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