Electric field measuring device for continuously tunable microwave frequency based on Rydberg atoms

Abstract

The invention provides an electric field measuring device for continuously tunable microwave frequency based on Rydberg atoms. The electric field measuring device comprises a reflecting mirror, an atom steam pool, a first electrode plate, a second electrode plate, a dichroscope, a photoelectric detector and a data receiving module, the detection laser passing through the reflector and the coupling laser passing through the dichroscope oppositely hit into the atom steam pool to coincide, and a transmitted optical signal enters the photoelectric detector after hit into the atom steam pool; the photoelectric detector is electrically connected with the data receiving module; the first electrode plate and the second electrode plate are externally arranged above and below the atomic steam pool respectively; the first electrode plate and the second electrode plate are used for applying an alternating current electric field acting on the atomic steam pool, and different AC Stark frequency shifts are generated by controlling the electric field intensity of the alternating current electric field, so that high-sensitivity measurement of the continuous tunable microwave frequency electric field is realized. According to the invention, high-sensitivity measurement of the continuous tunable microwave frequency electric field can be realized, and the accuracy of a measurement result is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electric field measurement, and in particular to an electric field measurement device based on Rydberg atoms and continuously tunable microwave frequency. Background Art

[0002] With the gradual development of physics research, the traditional electric field measurement method is limited by the thermal noise limit. The detection principle is to use the electric field to induce the metal to generate current. The metal itself will interfere with the electric field to be measured, so the accuracy of the traditional measurement method is low.

[0003] With the redefinition of international units and the rapid development of quantum measurement technology, researchers have developed measurement methods based on Rydberg atomic resonance (EIT-AT) spectroscopy and techniques for measuring continuous ultra-low frequency electric fields using the DC Stark effect of Rydberg atoms. Rydberg atoms are atoms whose outermost electrons are excited to a highly excited state with a large principal quantum number.

[0004] The measurement method based on Rydberg atomic resonance (EIT-AT) spectroscopy uses the EIT-AT splitting spectrum of Rydberg atoms to measure electric field strength. Two microwave sources (i.e., signal generators that emit a certain frequency and power) serve as the local oscillation field (LO field) and signal field (SIG field), respectively. These are applied to the atoms via two horn antennas. The difference frequency signal generated by the interference is applied to the detection light field and then detected by a photodetector. The resultant signal is then analyzed to measure the electric field strength at a single frequency. However, this method can only measure the electric field at a specific frequency (single frequency) that resonates with adjacent Rydberg energy levels. In other words, it can only measure the electric field at a specific discrete frequency that resonates with the Rydberg energy level, and cannot achieve high-sensitivity measurement of arbitrary frequencies.

[0005] The DC Stark effect of Rydberg atoms is used to measure continuous ultra-low frequency electric fields. First, for electric fields below kHz, the low-frequency shielding effect of Rydberg atoms prevents them from acting on the atomic vapor cell. Therefore, an integrated built-in electrode plate vapor cell is used. Two laser beams are directed towards each other through a high-reflection mirror (HR) and a dichroic mirror (DM), respectively, and then overlap in the cesium atomic vapor cell. The dichroic mirror almost completely transmits light of certain wavelengths and almost completely reflects waves of other wavelengths. Two half-wave plates are set to control (change) the polarization of the lasers. The two electrode plates built into the vapor cell generate a DC electric field through a signal generator, causing the EIT spectral line to frequency shift and split. Then, an ultra-low frequency AC signal is applied as the signal field, and the continuous ultra-low frequency electric field is measured using DC-Stark frequency shift analysis. This technology mainly utilizes the electromagnetically induced transparency (EIT) effect and DC-Stark effect of Rydberg atoms. Electromagnetically induced transparency (EIT) refers to the phenomenon in which a medium's absorption of probe light decreases under the influence of an electromagnetic field. It's a quantum coherence effect, resulting from the destructive coherence between two possible excitation channels in a three-level atomic system. In existing solutions, the atomic gas chamber is made of a non-metallic material, and the integrated electrode plate within the vapor pool destroys this unique non-metallic property, potentially reflecting microwaves emitted by the horn antenna and affecting the accuracy of experimental results.

[0006] In summary, existing electric field measurement methods cannot achieve continuously tunable (tuning is the act or process of adjusting to a resonant state, specifically a frequency adjustment in which the frequency of microwave emission resonates with the frequency of energy level resonance) high-sensitivity measurement of microwave frequency electric fields, and cannot guarantee the accuracy of the measurement results. Summary of the Invention

[0007] In response to the problem that traditional electric field measurement methods cannot achieve high-sensitivity measurement of continuously tunable microwave frequency electric fields and cannot guarantee the accuracy of measurement results, the present invention provides an electric field measurement device with continuously tunable microwave frequency based on Rydberg atoms to achieve high-sensitivity measurement of continuously tunable microwave frequency electric fields and ensure the accuracy of measurement results.

[0008] The present invention provides an electric field measurement device based on Rydberg atoms and having a continuously tunable microwave frequency, comprising a reflector, an atomic vapor cell, a first electrode plate, a second electrode plate, a dichroic mirror, a photodetector, and a data receiving module;

[0009] The detection laser passing through the reflector and the coupling laser passing through the dichroic mirror hit the inside of the atomic vapor pool in opposite directions and overlap, and the light signal passing through the atomic vapor pool enters the photodetector; the photodetector is electrically connected to the data receiving module;

[0010] The local oscillator field and the signal field act on the atomic vapor pool; the first electrode plate and the second electrode plate external to the atomic vapor pool are respectively arranged above and below the atomic vapor pool; the first electrode plate and the second electrode plate are used to apply an alternating current electric field acting on the atomic vapor pool, and the alternating current electric field is used to cause the Rydberg energy level to undergo an AC Stark frequency shift. Different alternating current electric fields correspond to different AC Stark frequency shifts. Different AC Stark frequency shifts are generated by controlling the electric field strength of the alternating current electric field, thereby achieving high-sensitivity measurement of continuously tunable microwave frequency electric fields.

[0011] Optionally, the electric field measuring device further comprises a first half-wave plate and a second half-wave plate;

[0012] The detection laser passes through the first half-wave plate and the reflector in sequence and is vertically incident on the first side of the atomic vapor pool; the coupling laser passes through the second half-wave plate and hits the dichroic mirror, and is reflected and vertically incident on the second side of the atomic vapor pool;

[0013] The first half-wave plate is used to control the polarization of the detection laser, and the second half-wave plate is used to control the polarization of the coupling laser, so that the polarizations of the detection laser and the coupling laser are consistent with the polarization of the microwave.

[0014] Optionally, the electric field measurement device further includes a detection light generator and a coupling light generator;

[0015] The detection light generator is used to emit detection laser;

[0016] The coupling light generator is used for emitting coupling laser light.

[0017] Optionally, the electric field measuring device further comprises two horn antennas;

[0018] The local oscillator field and the signal field are radiated into space through the horn antenna respectively to act on the atomic vapor pool.

[0019] Optionally, the local oscillator field and the signal field are incident vertically into the atomic vapor pool in the same direction.

[0020] Optionally, the first electrode plate and the second electrode plate are respectively arranged directly above and directly below the atomic vapor pool.

[0021] Optionally, the first electrode plate and the second electrode plate are both parallel to the ground.

[0022] Optionally, the optical path plane in the electric field measuring device is parallel to the ground; the detection laser and the coupling laser overlap in space after passing through the reflector and the dichroic mirror respectively.

[0023] Optionally, the atomic vapor cell is a cesium atomic vapor cell.

[0024] Optionally, the data receiving module is an oscilloscope.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0026] 1. The present invention arranges electrode plates (including a first electrode plate and a second electrode plate) outside the atomic vapor cell. An alternating current electric field applied by the external electrode plates acts on the atomic vapor cell. The alternating current electric field can cause an AC Stark frequency shift in the Rydberg energy level. The AC Stark frequency shift can be used to achieve high-sensitivity measurement of continuously tunable microwave frequency electric fields. Different alternating current electric fields correspond to different AC Stark frequency shifts. By controlling the electric field strength of the alternating current electric field, high-sensitivity measurement of continuously tunable microwave frequency electric fields can be achieved. The external electrode plates will not destroy the unique non-metallic properties of the atomic vapor cell, thereby ensuring the accuracy of the measurement results.

[0027] 2. The present invention combines the AC Stark effect of Rydberg atoms to tune the microwave frequency under the energy level shift of cesium atoms to make them re-resonant, which can achieve high-sensitivity electric field measurement at continuous microwave frequencies. The present invention can be applied to the field of electric field strength measurement technology in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic structural diagram of an electric field measurement device with continuously tunable microwave frequency based on Rydberg atoms proposed in an embodiment of the present invention.

[0029] Figure 2 This is an AC Stark spectrum diagram of the two Rydberg states 78S and 78P of a cesium atom in the electric field measurement device according to an embodiment of the present invention.

[0030] Figure 3 1 is an energy level diagram of the electric field measurement device according to an embodiment of the present invention.

[0031] Figure 4 Schematic diagram of the EIT phenomenon and AT splitting phenomenon displayed on the data receiving module in an embodiment of the present invention.

[0032] Icons: 101-reflecting mirror, 102-atomic vapor cell, 103-first electrode plate, 104-second electrode plate, 105-dichroic mirror, 106-photodetector, 107-data receiving module, 108-first half-wave plate, 109-second half-wave plate, 110-detection light generator, 111-coupling light generator. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0035] Example

[0036] like Figure 1 As shown, the embodiment of the present invention provides an electric field measurement device based on Rydberg atoms with continuously tunable microwave frequency, comprising a reflector 101, an atomic vapor cell 102, a first electrode plate 103, a second electrode plate 104, a dichroic mirror 105, a photodetector 106 and a data receiving module 107;

[0037] The detection laser light passing through the reflector 101 and the coupling laser light passing through the dichroic mirror 105 hit the inside of the atomic vapor pool 102 in opposite directions and overlap, and the light signal passing through the atomic vapor pool 102 enters the photodetector 106; the photodetector 106 is electrically connected to the data receiving module 107;

[0038] The local oscillator field and the signal field act on the atomic vapor pool 102; the first electrode plate 103 and the second electrode plate 104 external to the atomic vapor pool 102 are respectively arranged above and below the atomic vapor pool 102; the first electrode plate 103 and the second electrode plate 104 are used to apply an AC electric field acting on the atomic vapor pool 102, and the AC electric field is used to cause the Rydberg energy level to undergo an AC Stark frequency shift, such as Figure 2As shown, different AC electric fields correspond to different AC Stark frequency shifts. By controlling the electric field intensity of the AC electric field, different AC Stark frequency shifts occur, thereby achieving high-sensitivity measurement of continuously tunable microwave frequency electric fields. Figure 3 Shown is an energy level diagram of the electric field measurement device according to an embodiment of the present invention.

[0039] The optical path and electrical signal process of the electric field measurement device are as follows:

[0040] The local oscillator field and the signal field hit the atomic vapor pool 102; the detection laser passing through the reflector 101 and the coupling laser passing through the dichroic mirror 105 hit the inside of the atomic vapor pool 102 in opposite directions and overlap; the light signal transmitted after the detection laser and the coupling laser hit the atomic vapor pool 102 in opposite directions enters the photodetector 106, is converted into an electrical signal by the photodetector 106, and is received by the data receiving module 107, and the electric field strength of the signal field is obtained by using the electrical signal; the optical signal is the detection laser carrying the microwave difference frequency signal; the electrical signal is represented as a sinusoidal oscillation signal in the data receiving module 107, Figure 4 FIG. 1 is a schematic diagram showing the EIT phenomenon and the AT splitting phenomenon displayed on the data receiving module 107 .

[0041] In some embodiments, the electric field measurement device further includes a first half-wave plate 108 and a second half-wave plate 109;

[0042] The detection laser passes through the first half-wave plate 108 and the reflector 101 in sequence and is vertically incident on the first side surface of the atomic vapor pool 102. After being vertically emitted from the second side surface of the atomic vapor pool 102, it passes through the dichroic mirror 105 and directly enters the photodetector 106, where the optical signal is received by the data receiving module 107. The coupling laser passes through the second half-wave plate 109 and hits the dichroic mirror 105, where it is reflected and vertically incident on the second side surface of the atomic vapor pool 102.

[0043] The first half-wave plate 108 and the second half-wave plate 109 are used to control the polarization of the detection laser and the coupling laser so that the polarization of the detection laser and the coupling laser is consistent with the polarization of the microwave.

[0044] In some embodiments, the electric field measurement device further includes a probe light generator 110 and a coupling light generator 111;

[0045] The detection light generator 110 is used to emit detection laser;

[0046] The coupling light generator 111 is used to emit coupling laser light.

[0047] In fact, any device can generate both the detection laser and the coupling laser.

[0048] In some embodiments, the electric field measurement device further comprises two horn antennas;

[0049] The local oscillator field and the signal field are radiated into space through a horn antenna, respectively, and act on the atomic vapor pool 102. Furthermore, the horn antenna needs to be positioned so that the local oscillator field and the signal field are incident perpendicularly to the atomic vapor pool 102 in the same direction, ensuring that the microwaves of the local oscillator field and the signal field directly impact the atomic vapor pool 102.

[0050] In some embodiments, the first electrode plate 103 and the second electrode plate 104 external to the atomic vapor pool 102 are respectively arranged directly above and directly below the atomic vapor pool 102, ensuring that the alternating electric field applied by the first electrode plate 103 and the second electrode plate 104 acts uniformly on the atomic vapor pool 102.

[0051] In some embodiments, the first electrode plate 103 and the second electrode plate 104 are both parallel to the ground.

[0052] In some embodiments, the optical path plane in the electric field measurement device is parallel to the ground; the detection laser and the coupling laser overlap in space after passing through the reflector 101 and the dichroic mirror 105 respectively.

[0053] In some embodiments, the atomic vapor cell 102 is a cesium atomic vapor cell 102 .

[0054] In some embodiments, the data receiving module 107 is an oscilloscope.

[0055] From the above we can know:

[0056] 1. The present invention arranges electrode plates (including a first electrode plate 103 and a second electrode plate 104) outside the atomic vapor pool 102. The AC electric field applied by the external electrode plates acts on the atomic vapor pool 102. The AC electric field can cause the Rydberg energy level to undergo an AC Stark frequency shift. The AC Stark frequency shift can be used to achieve high-sensitivity measurement of continuously tunable microwave frequency electric fields. Different AC electric fields correspond to different AC Stark frequency shifts. By controlling the electric field strength of the AC electric field, high-sensitivity measurement of continuously tunable microwave frequency electric fields can be achieved. The external electrode plates will not destroy the unique non-metallic properties of the atomic vapor pool 102, thereby ensuring the accuracy of the measurement results.

[0057] 2. This invention combines the AC Stark effect of Rydberg atoms to tune the microwave frequency to re-reach resonance when the cesium atomic energy level shifts, enabling highly sensitive electric field measurements at continuous microwave frequencies. This invention may be applied in the field of electric field strength measurement technology in the future.

[0058] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A Rydberg atom-based electric field measurement device with continuously tunable microwave frequency, characterized in that: It comprises a reflecting mirror (101), an atomic vapor pool (102), a first electrode plate (103), a second electrode plate (104), a dichroic mirror (105), a photodetector (106) and a data receiving module (107); The detection laser light passing through the reflector (101) and the coupling laser light passing through the dichroic mirror (105) hit the inside of the atomic vapor pool (102) in opposite directions and overlap, and the light signal passing through the atomic vapor pool (102) enters the photodetector (106); the photodetector (106) is electrically connected to the data receiving module (107); The local oscillator field and the signal field act on the atomic vapor pool (102); the first electrode plate (103) and the second electrode plate (104) external to the atomic vapor pool (102) are respectively arranged above and below the atomic vapor pool (102); the first electrode plate (103) and the second electrode plate (104) are used to apply an alternating current electric field acting on the atomic vapor pool (102); the alternating current electric field is used to cause the Rydberg energy level to undergo an AC Stark frequency shift; different alternating current electric fields correspond to different AC Stark frequency shifts; different AC Stark frequency shifts are generated by controlling the electric field intensity of the alternating current electric field, thereby realizing high-sensitivity measurement of continuously tunable microwave frequency electric fields.

2. The electric field measuring device based on Rydberg atoms and continuously tunable microwave frequency according to claim 1, characterized in that: The electric field measuring device further comprises a first half-wave plate (108) and a second half-wave plate (109); The detection laser passes through the first half-wave plate (108) and the reflector (101) in sequence and then vertically incident on the first side of the atomic vapor pool (102); the coupling laser passes through the second half-wave plate (109) and then hits the dichroic mirror (105) and is reflected and vertically incident on the second side of the atomic vapor pool (102); The first half-wave plate (108) is used to control the polarization of the detection laser, and the second half-wave plate (109) is used to control the polarization of the coupling laser, so that the polarizations of the detection laser and the coupling laser are consistent with the polarization of the microwave.

3. The electric field measuring device based on Rydberg atoms and continuously tunable microwave frequency according to claim 1, characterized in that: The electric field measuring device further comprises a detection light generator (110) and a coupling light generator (111); The detection light generator (110) is used to emit detection laser light; The coupling light generator (111) is used for emitting coupling laser light.

4. The electric field measuring device based on Rydberg atoms and continuously tunable microwave frequency according to claim 1, characterized in that: The electric field measuring device also includes two horn antennas; The local oscillator field and the signal field are radiated into space through the horn antenna respectively to act on the atomic vapor pool (102).

5. The electric field measuring device based on Rydberg atoms and having continuously tunable microwave frequency according to claim 4, characterized in that: The local oscillator field and the signal field are incident vertically into the atomic vapor pool (102) in the same direction.

6. The electric field measuring device based on Rydberg atoms and continuously tunable microwave frequency according to claim 1, characterized in that: The first electrode plate (103) and the second electrode plate (104) are respectively arranged directly above and directly below the atomic vapor pool (102).

7. The electric field measuring device based on Rydberg atoms and continuously tunable microwave frequency according to claim 1 or 6, characterized in that: The first electrode plate (103) and the second electrode plate (104) are both parallel to the ground.

8. The electric field measuring device with continuously tunable microwave frequency based on Rydberg atoms according to claim 1, characterized in that: The optical path plane in the electric field measuring device is parallel to the ground; the detection laser and the coupling laser overlap in space after passing through the reflector (101) and the dichroic mirror (105) respectively.

9. The electric field measuring device with continuously tunable microwave frequency based on Rydberg atoms according to claim 1, characterized in that: The atomic vapor pool (102) is a cesium atomic vapor pool (102).

10. The electric field measuring device with continuously tunable microwave frequency based on Rydberg atoms according to claim 1, characterized in that: The data receiving module (107) is an oscilloscope.

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