Microwave electric field measurement method and device based on Rydberg atom Labir resonance

Abstract

The invention discloses a microwave electric field measurement method and device based on Rydberg atom Rabian resonance, and the key point of the technical scheme is that the microwave electric field measurement device comprises an alkali metal atom gas chamber, a static magnetic field generation device, detection light, coupling light, a dichroscope, a photoelectric detector, an arbitrary waveform generator (AWG) and a horn antenna; sinusoidal phase modulation is applied to the microwave, the modulation frequency is variable, the Labir frequency of the microwave to be measured is obtained through a Labir resonance curve by utilizing Labir resonance generated between the phase modulation microwave and the three-energy-level Rydberg atoms, finally the electric field intensity of the microwave to be measured can be obtained through a microwave electric field intensity traceability formula, and under the action of a static magnetic field, the electric field intensity of the microwave to be measured can be measured. And the degeneracy of the atomic hyperfine energy level is destroyed, so that the measurement result is more accurate, and the measurement frequency band is wider. Moreover, the method can achieve the self-calibration measurement of the microwave electric field, and enables the magnitude of the amplitude of the electric field to be directly traced to the international unit system (SI system).

Description

Technical Field

[0001] The present invention relates to the technical field of quantum precision measurement, and in particular to a microwave electric field measurement method and device based on Rydberg atom Rabi resonance. Background Art

[0002] Microwaves are widely used in radar detection, aerospace, national defense construction and other fields. Microwave measurement technology is often used to transmit and receive microwave signals and obtain information. The premise and core of traditional microwave measurement methods is to have calibrated probes or antennas. Taking the dipole probe as an example, it faces the following limitations in application: (1) It needs to be calibrated; (2) The detection sensitivity depends on the dipole length; (3) The metal parts in the probe will interfere with the microwave field to be measured; (4) The sensitivity is limited to the minimum detectable field strength (100mV / m). Other types of traditional antennas also have similar limitations. The achievable "known" field uncertainty is generally 5% (or 0.5dB).

[0003] Research has shown that in physical systems where atoms interact with microwaves, the specific relationship between the Rabi frequency of atomic transitions and the microwave field intensity can be used to infer the field intensity value by measuring the Rabi frequency. As we all know, frequency maintains the highest measurement accuracy of all physical quantities currently available, which means that atom-based microwave field measurement technology has great development potential for high precision and self-calibration. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a microwave electric field measurement method and device based on the Rabi resonance of Rydberg atoms, wherein sinusoidal phase modulation is applied to microwaves with a variable modulation frequency, and the Rabi resonance between the phase-modulated microwaves and the three-level Rydberg atoms is utilized to obtain the Rabi frequency of the microwave to be measured through the Rabi resonance curve, and finally the electric field intensity of the microwave to be measured can be obtained through the microwave electric field intensity tracing formula, and under the action of the static magnetic field, the degeneracy of the atomic hyperfine energy levels is destroyed, so that the measurement result is more accurate and the measurement frequency band is wider, and this method can realize self-calibration measurement of the microwave electric field, and the value of the electric field amplitude can be directly traced back to the International System of Units (SI system).

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A microwave electric field measuring device based on Rydberg atomic Rabi resonance, comprising: an alkali metal atom gas chamber, a static magnetic field generating device, a detection light, a coupling light, a dichroic mirror, a photodetector, an arbitrary waveform generator and a horn antenna;

[0007] Preferably, the static magnetic field generating device is composed of three groups of square Helmholtz coils, which are orthogonal to each other and generate continuously adjustable static magnetic fields in three directions. Two groups are used to offset the ambient magnetic field, and the other group is used to provide a static magnetic field that breaks the degeneracy of hyperfine energy levels, which not only provides a quantization axis, but also plays a role in adjusting the transition frequency of ground state atoms, and can be used to realize microwave detection with continuously adjustable frequency.

[0008] Preferably, the atomic gas chamber needs to be supported and fixed by special materials. Teflon is selected in this experiment because the loss factor of Teflon is 0.0005, which can be regarded as transparent to microwaves and the influence on the electric field measurement can be ignored. The alkali metal atomic gas chamber adopts cesium atomic 133 Cs is used as the working substance.

[0009] Preferably, the detection light uses an 852nm laser and the coupling light uses a 509nm laser, and both achieve laser frequency locking to maintain the accuracy and stability of the measurement system. After the coupling light and the detection light pass through the alkali metal atom gas chamber in the same line and in opposite directions, the detection light needs to be separated from the coupling light by the dichroic mirror and reflected to the photodetector to obtain a signal.

[0010] Preferably, it is necessary to ensure that the distance between the atomic gas chamber and the horn antenna emitting microwaves meets the far field condition, and the far field distance R must satisfy the formula: R ≥ 2D 2 / λ, where D is the size of the horn antenna, and λ is the wavelength of the incident microwave, so that the microwave is as uniform as possible in the interaction zone and approximates a plane wave, so that the measurement result is accurate. It is necessary to use absorbing materials to build a microwave darkroom around the measuring device to reduce the reflection of microwaves, because microwaves are easily reflected by metal equipment, and many devices in the environment, such as the optical platform, are made of metal.

[0011] Preferably, a microwave electric field measurement method based on the Rabi resonance of the Rydberg atom is applicable to any of the microwave electric field measurement devices based on the Rabi resonance of the Rydberg atom described above, and specifically comprises the following steps:

[0012] Step 101: After the detection light and the coupling light are frequency-locked, the two lights are collinearly injected into the atomic gas chamber in opposite directions, and a static magnetic field of a specific intensity is applied to the atomic gas chamber to excite a three-level Rydberg state system;

[0013] Step 102: Select the fourth Rydberg energy level, couple the microwave frequency emitted by the arbitrary waveform generator through the horn antenna with the third and fourth Rydberg energy levels, perform sinusoidal phase modulation on the microwaves, and feed the microwaves into the atomic gas chamber;

[0014] Step 103: Scan the phase modulation frequency ω point by point m, perform FFT on the transmission signal of the detection light to obtain point-by-point scanning Data points, using polynomial fitting to get And Ω=2ω m ,Finally, the microwave field intensity to be measured can be obtained by using the traceability formula.

[0015] Preferably, the step 101 specifically includes:

[0016] First, the detection light and coupling light laser are frequency locked, and then the coupling light and detection light pass through the atomic gas chamber from both ends through free space, and the two beams are kept collinear and reversed. Under the joint action of single-photon and two-photon resonant detection light and coupling light, an electromagnetically induced transparent window is formed. At this time, the electromagnetically induced transparent EIT signal can be observed, and the atoms in the gas chamber are excited to the Rydberg state. The static magnetic field generating device is turned on to apply a static magnetic field B of a certain intensity to the atomic gas chamber. 0 , which is used to break the degeneracy of hyperfine energy levels, provides a quantization axis, and also plays a role in adjusting the transition frequency of ground state atoms. It can be used to realize microwave measurement with continuously adjustable frequency.

[0017] Preferably, the step 102 specifically includes:

[0018] According to the third energy level of the prepared Rydberg state atom, the fourth Rydberg state energy level is selected, and the transition frequency f between the third and fourth energy levels can be obtained by calculation. atom , turn on the arbitrary waveform generator and set the microwave frequency f MW Set at f atom , so that its detuning Δf=0, the microwave is fed into the atomic gas chamber through the horn antenna, and at the same time, the distance between the atomic gas chamber and the horn antenna is ensured to meet the far-field condition R≥2D 2 / λ, and then the microwave signal is sinusoidally phase modulated. The applied phase modulation function can be expressed as: θ(t) = msin(ω m t), where m is the phase modulation coefficient, ω m is the phase modulation frequency.

[0019] Preferably, the step 103 specifically includes:

[0020] The interaction between Rydberg atoms and phase-modulated microwaves can excite Rydberg atoms to undergo Rabi resonance. The amplitude of the resonance signal Pβ0 is a function of the modulation frequency ωm, as shown in the following formula:

[0021]

[0022] Among them, γ1 is the longitudinal and transverse relaxation rate, ωm is the phase modulation frequency, Ω is the Rabi frequency of microwaves, and γ1 and ωm are both known quantities;

[0023] It is easy to know that the function Pβ0(ωm) has a peak value when ωm=Ω / 2;

[0024] While scanning the phase modulation frequency ωm of the microwave, the transmission signal of the detection light is subjected to FFT to record the signal amplitude Pβ0, and the relationship curve Pβ0(ωm) between the point-by-point scanning modulation frequency ωm and the amplitude amplitude Pβ0, i.e., the Rabi resonance curve, can be obtained. The Rabi frequency Ω=2ωm of the corresponding microwave can be obtained by the ωm at the corresponding signal amplitude peak value Pβ0-peak in the curve;

[0025] The traceability formula for measuring microwave electric field intensity using Rydberg atoms is shown in the following formula:

[0026]

[0027] Where E MW is the intensity of the microwave electric field to be measured, is the reduced Planck constant, μ MW represents the transition dipole moment corresponding to microwaves, where and μ MW All are known quantities;

[0028] The electric field intensity of microwaves can be calculated using the source tracing formula.

[0029] Preferably, after step 103, the method further includes:

[0030] The third Rydberg energy level can be changed by changing the frequency of the coupled light, thereby achieving microwave electric field measurements over a wide frequency band; the transition frequency of atoms between Rydberg energy levels can also be changed by changing the size of the static magnetic field, thereby achieving more precise microwave electric field measurements.

[0031] In summary, the present invention mainly has the following beneficial effects:

[0032] 1. The microwave electric field measurement device and method based on the Rabi resonance of Rydberg atoms of the present invention utilizes the Rabi resonance between microwaves and Rydberg atoms to link the microwave sinusoidal phase modulation frequency with the Rabi frequency, and then utilizes the traceability formula of Rydberg atoms to measure the microwave electric field strength to obtain the electric field strength of the microwave to be measured. Therefore, this method can realize self-calibration and convert the electric field strength E of the microwave to be measured into the electric field strength E of the microwave to be measured. MW Directly related to physical constants, traceable to fundamental physical quantities;

[0033] 2. The microwave electric field measurement device and method based on the Rabi resonance of the Rydberg atom of the present invention, wherein the atom probe is composed of atoms and a glass shell, and does not contain metal, so that the interference to the electric field to be measured is reduced;

[0034] 3. The microwave electric field measurement device and method based on the Rydberg atom Rabi resonance of the present invention can realize microwave electric field measurement in the entire microwave band by changing the frequency of the coupled light or the size of the static magnetic field, while achieving the measurement advantages of high sensitivity and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of a microwave electric field measuring device based on the Rabi resonance of Rydberg atoms of the present invention;

[0036] Figure 2 It is a flow chart of the microwave electric field measurement method based on the Rabi resonance of the Rydberg atom of the present invention;

[0037] Figure 3 It is a schematic diagram of the energy level structure of the microwave electric field measurement implementation process based on the Rydberg atom Rabi resonance of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1

[0040] refer to Figure 1 As shown, the present invention provides a microwave electric field measurement device based on Rydberg atom Rabi resonance, including an alkali metal atom gas chamber 1, a static magnetic field generating device 2, a detection light 3, a coupling light 4, a dichroic mirror 5, a detector 6, an arbitrary waveform generator 7 and a horn antenna 8.

[0041] The atomic gas chamber 1 is placed in a static magnetic field generating device 2. The atomic gas chamber 1 needs to be supported and fixed with special materials. Teflon is selected in this experiment because the loss factor of Teflon is 0.0005, which can be regarded as transparent to microwaves and the influence on the electric field measurement can be ignored. The detection light 3 and the coupling light 4 are respectively passed through the alkali metal atomic gas chamber 1, and the light is kept in the opposite collinear direction to excite the three-level Rydberg state system of the atoms in the gas chamber, including the ground state, the intermediate state and the Rydberg state, and the EIT signal generated is used to lock the laser frequency. At this time, the Rydberg state energy level of the atom is a determined energy level. A static magnetic field B of a specific intensity is applied to the atomic gas chamber 1 through the static magnetic field generating device 2. 0 It can be used to break the degeneracy of hyperfine energy levels and also to regulate the frequency of ground state atomic transitions.

[0042] The microwave 9 of a specific frequency is generated by the arbitrary waveform generator 7, and this microwave frequency can couple another Rydberg energy level with the three-level Rydberg state system. This microwave frequency can be calculated based on the two Rydberg energy levels; at the same time, sinusoidal phase modulation is applied to the microwave, and the microwave 9 is fed into the atomic gas chamber 1 through the horn antenna 8. At the same time, it is necessary to ensure that the distance between the atomic gas chamber 1 and the horn antenna 8 that transmits the microwave meets the far-field condition, so that the microwave is as uniform as possible in the interaction area and approximates a plane wave, so that the measurement result is accurate, and a microwave darkroom is built around the measuring device with absorbing materials to reduce microwave reflection.

[0043] At this time, the sinusoidal phase modulation frequency of the microwave is scanned, and the detection light 3 passing through the gas chamber 1 is separated from the coupled light 4 by the dichroic mirror 5 and reflected to the detector 6 to obtain the signal. The relationship between the sinusoidal modulation frequency and the Rabi resonance amplitude can be obtained by performing FFT on the signal obtained by the detector 6; the Rabi frequency of the microwave can be obtained through the Rabi resonance curve, and finally the electric field intensity of the microwave can be calculated through the source tracing formula of the microwave electric field intensity.

[0044] like Figure 3 As shown, cesium atoms 133 Cs as an example, Figure 3 For cesium atoms 133 Energy level diagram of Cs, 301 is the ground state of cesium atom 6 2 S 1 / 2 ,F=4,302 is the intermediate excited state of cesium atom6 2 P 3 / 2 , F = 5, 303 and 304 are both Rydberg states of cesium atoms. Theoretically, this method can use many Rydberg state energy levels to achieve electric field measurement in the entire microwave band. In this experiment, 303 is used as 64D 5 / 2 , 304 is 61F 7 / 2 For example, 305 is the detection light with a wavelength of 852nm, 306 is the coupling light with a wavelength of 509nm, and 307 is the Rydberg state 64D 5 / 2 →61F 7 / 2 The microwave signal with inter-electrode transition resonance and frequency is 16.23736GHz.

[0045] When the 852nm laser frequency is locked at 301→302 and the 509nm laser scans around 302→303, a step-type energy level EIT transmission peak can be observed at the two-photon resonance. The EIT signal can be used to lock the frequency of the 509nm laser at 302→303.

[0046] At this time, microwave 307 with a fixed frequency is injected, and the microwave frequency f MW The transition frequency f between Rydberg levels 303→304 atomThe detuning Δf=0 is achieved, and the microwave 307 is phase-modulated and fed into the atomic gas chamber. Then, the three-level Rydberg atoms interact with the phase-modulated microwaves to generate Rabi resonance.

[0047] Embodiment 2

[0048] like Figure 2 As shown, based on the device of the above embodiment, the present invention also provides a microwave electric field measurement method based on Rydberg atom Rabi resonance, comprising the following steps:

[0049] Step 101: After the detection light and the coupling light are frequency-locked, the two lights are collinearly injected into the atomic gas chamber in opposite directions, and a static magnetic field of a specific intensity is applied to the atomic gas chamber to excite a three-level Rydberg state system;

[0050] Step 102: Select the fourth Rydberg energy level, couple the microwave frequency emitted by the arbitrary waveform generator through the horn antenna with the third and fourth Rydberg energy levels, perform sinusoidal phase modulation on the microwaves, and feed the microwaves into the atomic gas chamber;

[0051] Step 103: Scan the phase modulation frequency ω point by point m , perform FFT on the transmission signal of the detection light to obtain point-by-point scanning Data points, using polynomial fitting to get And Ω=2ω m ,Finally, the microwave field intensity to be measured can be obtained by using the traceability formula.

[0052] The microwave electric field measurement based on the Rydberg atomic Rabi resonance involved in the present invention has the following working principle: firstly, the detection light and the coupling light laser are frequency-locked, and then the coupling light and the detection light are passed through the atomic gas chamber from both ends through free space, and the two light beams are kept collinear and reversed. Under the joint action of the single-photon and two-photon resonant detection light and the coupling light, an electromagnetically induced transparent window is formed, at which time the electromagnetically induced transparent EIT signal can be observed, and at this time the atoms in the gas chamber are excited to the Rydberg state; the static magnetic field generating device is turned on to apply a static magnetic field B of a certain intensity to the atomic gas chamber. 0 , which is used to break the degeneracy of hyperfine energy levels, provides a quantization axis, and also plays a role in adjusting the transition frequency of ground state atoms. It can be used to realize microwave measurement with continuously adjustable frequency.

[0053] According to the third energy level of the prepared Rydberg state atom, the fourth Rydberg state energy level is selected, and the transition frequency f between the third and fourth energy levels can be obtained by calculation. atom , turn on the arbitrary waveform generator and set the microwave frequency f MW Set at f atom, so that its detuning Δf=0, the microwave is fed into the atomic gas chamber through the horn antenna, and at the same time, the distance between the atomic gas chamber and the horn antenna is ensured to meet the far-field condition R≥2D 2 / λ, and then the microwave signal is sinusoidally phase modulated. The applied phase modulation function can be expressed as: θ(t) = msin(ω m t), where m is the phase modulation coefficient, ω m is the phase modulation frequency.

[0054] The interaction between Rydberg atoms and phase-modulated microwaves can excite Rydberg atoms to undergo Rabi resonance. The amplitude of the resonance signal is P β 0 is the modulation frequency ω m The function is shown in the following formula:

[0055]

[0056] Among them, γ 1 are the longitudinal and transverse relaxation rates, ω m is the phase modulation frequency, Ω is the Rabi frequency of microwaves, where γ 1 ,ω m All are known quantities;

[0057] It is easy to see that the function P β 0 (ω m ) in satisfying ω m =Ω / 2 when the peak value appears;

[0058] The phase modulation frequency ω of the scanning microwave m At the same time, the transmission signal of the detection light is subjected to FFT and the signal amplitude P is recorded. β 0 , we can get the point-by-point scanning modulation frequency ω m With amplitude P β 0 The relationship curve P β 0 (ω m ) is the Rabi resonance curve, through the corresponding signal amplitude peak in the curve ω m , we can get the corresponding microwave Rabi frequency Ω=2ω m .

[0059] The traceability formula for measuring microwave electric field intensity using Rydberg atoms is shown in the following formula:

[0060]

[0061] Where E MW is the intensity of the microwave electric field to be measured, is the reduced Planck constant, μ MW represents the transition dipole moment corresponding to microwaves, where and μ MW All are known quantities;

[0062] The electric field intensity of microwaves can be obtained by using the source tracing formula;

[0063] In addition, the third Rydberg energy level can be changed by changing the frequency of the coupled light, thereby achieving microwave electric field measurements over a wide frequency band; the transition frequency of atoms between Rydberg energy levels can also be changed by changing the size of the static magnetic field, thereby achieving more precise microwave electric field measurements.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microwave electric field measurement device based on the Rabi resonance of Rydberg atoms, It is characterized in that include: Alkali metal atom gas chamber, static magnetic field generating device, detection light, coupled light, dichroic mirror, photodetector, arbitrary waveform generator and horn antenna.

2. A microwave electric field measuring device based on Rydberg atom Rabi resonance according to claim 1, It is characterized in that The static magnetic field generating device is composed of three groups of square Helmholtz coils. The three groups of coils are orthogonal to each other and generate continuously adjustable static magnetic fields in three directions. Two of the groups are used to offset the ambient magnetic field, and the other group is used to provide a static magnetic field that breaks the degeneracy of hyperfine energy levels. It not only provides a quantization axis, but also plays a role in adjusting the transition frequency of ground state atoms. It can be used to realize microwave detection with continuously adjustable frequency.

3. The microwave electric field measuring device based on Rydberg atom Rabi resonance according to claim 1, It is characterized in that The atomic gas chamber needs to be supported and fixed by special materials. Teflon is selected in this experiment because the loss factor of Teflon is 0.0005, which can be regarded as transparent to microwaves and its influence on electric field measurement can be ignored. The alkali metal atomic gas chamber uses cesium atoms. 133 Cs is used as the working substance.

4. The microwave electric field measuring device based on Rydberg atom Rabi resonance according to claim 1, It is characterized in that The detection light adopts 852nm laser, and the coupling light adopts 509nm laser, and both realize laser frequency locking to maintain the accuracy and stability of the measurement system. After the coupling light and the detection light pass through the alkali metal atom gas chamber in the same line and in the opposite direction, the detection light needs to be separated from the coupling light by the dichroic mirror and reflected to the photodetector to obtain a signal.

5. The microwave electric field measuring device based on Rydberg atom Rabi resonance according to claim 1, It is characterized in that It is necessary to ensure that the distance between the atomic gas chamber and the horn antenna emitting microwaves meets the far-field condition. The far-field distance R must satisfy the formula: R ≥ 2D 2 / λ, where D is the size of the horn antenna, and λ is the wavelength of the incident microwave, so that the microwave is as uniform as possible in the interaction zone and approximates a plane wave, so that the measurement result is accurate. It is necessary to use absorbing materials to build a microwave darkroom around the measuring device to reduce the reflection of microwaves, because microwaves are easily reflected by metal equipment, and many devices in the environment, such as the optical platform, are made of metal.

6. A microwave electric field measurement method based on Rydberg atom Rabi resonance, applicable to a microwave electric field measurement device based on Rydberg atom Rabi resonance as claimed in any one of claims 1 to 5, It is characterized in that The specific steps include: Step 101: After the detection light and the coupling light are frequency-locked, the two lights are collinearly injected into the atomic gas chamber in opposite directions, and a static magnetic field of a specific intensity is applied to the atomic gas chamber to excite a three-level Rydberg state system; Step 102: Select the fourth Rydberg energy level, couple the microwave frequency emitted by the arbitrary waveform generator through the horn antenna with the third and fourth Rydberg energy levels, perform sinusoidal phase modulation on the microwaves, and feed the microwaves into the atomic gas chamber; Step 103: Scan the phase modulation frequency ω point by point m , perform FFT on the transmission signal of the detection light to obtain point-by-point scanning Data points, using polynomial fitting to get And Ω=2ω m ,Finally, the microwave field intensity to be measured can be obtained by using the traceability formula.

7. The microwave electric field measurement method based on Rydberg atom Rabi resonance according to claim 6, It is characterized in that The step 101 specifically includes: First, the detection light and coupling light laser are frequency locked, and then the coupling light and detection light pass through the atomic gas chamber from both ends through free space, and the two beams are kept collinear and reversed. Under the joint action of single-photon and two-photon resonant detection light and coupling light, an electromagnetically induced transparent window is formed. At this time, the electromagnetically induced transparent EIT signal can be observed, and the atoms in the gas chamber are excited to the Rydberg state. The static magnetic field generating device is turned on to apply a static magnetic field B of a certain intensity to the atomic gas chamber. 0 , which is used to break the degeneracy of hyperfine energy levels, provides a quantization axis, and also plays a role in adjusting the transition frequency of ground state atoms. It can be used to realize microwave measurement with continuously adjustable frequency.

8. The microwave electric field measurement method based on Rydberg atom Rabi resonance according to claim 6, It is characterized in that The step 102 specifically includes: According to the third energy level of the prepared Rydberg state atom, the fourth Rydberg state energy level is selected, and the transition frequency f between the third and fourth energy levels can be obtained by calculation. atom , turn on the arbitrary waveform generator and set the microwave frequency f MW Set at f atom , so that its detuning Δf=0, the microwave is fed into the atomic gas chamber through the horn antenna, and at the same time, the distance between the atomic gas chamber and the horn antenna is ensured to meet the far-field condition R≥2D 2 / λ, and then the microwave signal is sinusoidally phase modulated. The applied phase modulation function can be expressed as: θ(t) = msin(ω m t), where m is the phase modulation coefficient, ω m is the phase modulation frequency.

9. The microwave electric field measurement method based on Rydberg atom Rabi resonance according to claim 6, It is characterized in that The step 103 specifically includes: The interaction between Rydberg atoms and phase-modulated microwaves can excite Rydberg atoms to undergo Rabi resonance. The amplitude of the resonance signal Pβ0 is a function of the modulation frequency ωm, as shown in the following formula: Among them, γ1 is the longitudinal and transverse relaxation rate, ωm is the phase modulation frequency, Ω is the Rabi frequency of microwaves, and γ1 and ωm are both known quantities; It is easy to know that the function Pβ0(ωm) has a peak value when ωm=Ω / 2; While scanning the phase modulation frequency ωm of the microwave, the transmission signal of the detection light is subjected to FFT to record the signal amplitude Pβ0, and the relationship curve Pβ0(ωm) between the point-by-point scanning modulation frequency ωm and the amplitude amplitude Pβ0, i.e., the Rabi resonance curve, can be obtained. The Rabi frequency Ω=2ωm of the corresponding microwave can be obtained by the ωm at the corresponding signal amplitude peak value Pβ0-peak in the curve; The traceability formula for measuring microwave electric field intensity using Rydberg atoms is shown below: Where E MW is the intensity of the microwave electric field to be measured, is the reduced Planck constant, ×10 -34 J·s,μ MW represents the transition dipole moment corresponding to microwaves, where and μ MW All are known quantities; The electric field intensity of microwaves can be calculated using the source tracing formula.

10. The microwave electric field measurement method based on Rydberg atom Rabi resonance according to claim 6, It is characterized in that After step 103, the method further includes: The third Rydberg energy level can be changed by changing the frequency of the coupled light, thereby achieving microwave electric field measurements over a wide frequency band; the transition frequency of atoms between Rydberg energy levels can also be changed by changing the size of the static magnetic field, thereby achieving more precise microwave electric field measurements.

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