Rydberg atomic electric field measurement enhancement device based on cavity enhancement technology

Abstract

The invention discloses a Rydberg atomic electric field measurement enhancement device based on a cavity enhancement technology, which belongs to the technical field of quantum measurement and comprises an atomic gas chamber with a resonant structure. A first spectroscope, a second spectroscope, a third spectroscope, a detection laser, a photoelectric detector, a polarization splitting prism and a coupling laser are arranged outside the atomic gas chamber; through the arrangement of the resonant structure, the sensing of the Rydberg atoms to the extremely-small microwave signals is enhanced, the measurement of the extremely-small microwave signals is realized, and the sensitivity of Rydberg atom measurement is improved; through the arrangement of a plurality of spectroscopes and other components, the intensity of light entering the atom gas chamber is increased, the interaction between detection laser and atoms is enhanced, the cyclic reflection of transmission light in the atom gas chamber is enhanced, and the measurement accuracy of the Rydberg atom microwave electric field is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of quantum measurement, and in particular relates to a Rydberg atom electric field measurement enhancement device based on cavity enhancement technology. Background Art

[0002] Quantum sensing is widely used in modern science and daily life. In recent years, as people's exploration of the microscopic world deepens, the characteristics of quantum systems have been widely disseminated, and quantum sensing has become more and more a hot topic of concern. This method breaks through the limitations of traditional sensors on sensing effects due to factors such as materials and size. In the field of modern microwave electric field measurement and perception, microwave signals are mostly tiny signals that are difficult to perceive. The development of microwave electric field measurement technology based on Rydberg atoms has made it possible to accurately verify and measure tiny microwave signals.

[0003] Atomic gas cells are the core components of quantum instruments such as atomic gyroscopes, atomic magnetometers and atomic clocks. High-performance miniature atomic gas cells are one of the important factors that restrict the performance of the above quantum instruments. The development demand for miniaturization, high precision and integration of quantum instruments indicates the development trend of miniaturization and integration of alkali metal atomic gas cells. The performance of atomic gas cells is a key factor affecting the sensitivity and accuracy of Rydberg atomic electric field measurement.

[0004] At present, the traditional Rydberg atom excitation optical path and atomic gas chamber are not sensitive enough to extremely small microwave signals. For extremely small signals, the EIT-AT splitting phenomenon produced by the EIT spectrum of excited Rydberg atoms is not obvious or even non-existent, and even if the EIT-AT splitting phenomenon occurs, the difference between the peak values ​​of the two split peaks is too large, resulting in nonlinear effects. Therefore, for extremely small microwave signals, the traditional Rydberg atom electric field measurement device still has defects. The higher the peak value of the EIT signal, the greater the signal intensity and the higher the measurement accuracy. At this stage, the signal intensity of EIT is usually enhanced by enhancing the power of the detection laser and the coupling laser, but this will also increase the line width of the EIT spectrum, which in turn reduces the measurement accuracy. Summary of the invention

[0005] The present invention aims to provide a Rydberg atom electric field measurement enhancement device based on cavity enhancement technology, which solves the problem that the traditional Rydberg atom excitation optical path and atomic gas chamber are not sensitive enough to extremely small microwave signals.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0007] A Rydberg atomic electric field measurement enhancement device based on cavity enhancement technology is provided, which includes an atomic gas chamber, a resonant structure is arranged on the outer wall of the atomic gas chamber, the resonant structure is used to sense microwave signals and generate resonance of natural frequency, a first spectroscope and a second spectroscope are arranged on the light incident side and the light exit side of the atomic gas chamber respectively, a third spectroscope is arranged on the top of the atomic gas chamber, a photoelectric detector is arranged on the refraction direction side of the third spectroscope, and the reflection direction of the third spectroscope is toward the position where the first spectroscope is located;

[0008] A detection laser is arranged on one side of the first beam splitter. The detection laser emits a detection laser toward the first beam splitter. The detection laser is horizontally transmitted through the first beam splitter to reach the second beam splitter. The second beam splitter reflects the detection laser and transmits it in the direction of the third beam splitter. The detection laser is reflected and refracted by the third beam splitter to reach the first beam splitter and the photoelectric detector respectively.

[0009] Furthermore, a polarization beam splitter prism is provided on the light emitting side of the atomic gas chamber, a coupling laser is provided on the top of the polarization beam splitter prism, and the coupling laser emits coupling laser toward the polarization beam splitter prism, and the coupling laser passes through the polarization beam splitter prism and is horizontally transmitted to reach the atomic gas chamber.

[0010] Furthermore, the wavelength of the detection laser emitted by the detection laser is 852nm.

[0011] Furthermore, the wavelength of the coupling laser emitted by the coupling laser is 509 nm.

[0012] Furthermore, the atomic gas chamber is a hollow columnar structure, and the resonant structure includes a plurality of microwave electric field enhancement components arranged on the circumferential outer wall of the atomic gas chamber. The plurality of microwave electric field enhancement components are arranged in a ring with the axis of the atomic gas chamber as the center, and each microwave electric field enhancement component is a hollow columnar structure with a fan-shaped cross-section, and a cavity is arranged inside each microwave electric field enhancement component; the sides of two adjacent microwave electric field enhancement components are connected.

[0013] Furthermore, each of the microwave electric field enhancement components is made of copper.

[0014] The beneficial effects of the present invention are:

[0015] 1. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology in this scheme is provided with a resonant structure on the outer wall of the atomic gas chamber. In the resonant structure, the physical structure of multiple microwave electric field enhancement components acts as an inductor, and the internal cavity acts as a capacitor. When there is a very small microwave signal in the environment, the microwave electric field resonance will occur at the contact position between the resonant structure and the atomic gas chamber, causing the microwave electric field resonance enhancement effect, which can significantly amplify the microwave electric field intensity in the cavity, enhance the response ability of the Rydberg atoms to it, avoid the nonlinear influence of the EIT-AT splitting that may exist in the EIT spectrum, and improve the sensitivity of the Rydberg atom microwave electric field measurement.

[0016] 2. In the Rydberg atomic electric field measurement enhancement device based on cavity enhancement technology in this scheme, when the laser emitted by the detection laser passes through the first beam splitter, the second beam splitter and the third beam splitter in sequence, and the post-coupling laser emits the coupling laser toward the polarization beam splitter prism, the atomic gas chamber is enhanced, the EIT spectrum peak is enhanced, and the line width increase caused by simply enhancing the detection laser power is avoided. The detection laser received by the photodetector is used to display the EIT spectrum on the oscilloscope. At the far detuning point of the coupling laser frequency, the circulating light intensity of the detection laser in the atomic gas chamber is the same as the transmission light intensity in free space, and the transmission intensity at other frequencies is normalized by this. When the coupling laser frequency is at the two-photon resonance, the electromagnetically induced transparency and optical pumping effects weaken the absorption of the detection laser by the atoms. These effects reduce the intracavity loss of the atomic gas chamber and improve the impedance matching efficiency of the atomic gas chamber, thereby increasing the light intensity entering the atomic gas chamber and enhancing the interaction between the detection laser and the atoms, so the transmission intensity of the detection laser also increases accordingly. Therefore, the transmitted light will be enhanced by cyclic reflection in the atomic gas chamber, which improves the accuracy of Rydberg atomic microwave electric field measurement and avoids the disadvantage of increasing the line width due to the enhanced EIT peak using enhanced laser power. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the Rydberg atom electric field measurement enhancement device based on cavity enhancement technology.

[0018] Figure 2 Schematic diagram of the structure in which the resonant structure is set on the outer wall of the atomic gas chamber.

[0019] Among them, 1. Atomic gas chamber; 2. First spectroscope; 3. Second spectroscope; 4. Third spectroscope; 5. Photodetector; 6. Detection laser; 7. Polarization spectroscope; 8. Coupling laser; 9. Microwave electric field enhancement element; 10. Cavity. DETAILED DESCRIPTION

[0020] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0021] like Figures 1-2 As shown, the present invention provides a Rydberg atomic electric field measurement enhancement device based on cavity enhancement technology, which includes an atomic gas chamber 1, wherein the outer wall of the atomic gas chamber 1 is provided with a resonant structure, and the resonant structure is used to sense microwave signals and generate resonance of natural frequency, specifically, as Figure 2 As shown, as a specific embodiment of the resonant structure, the atomic gas chamber 1 is a hollow columnar structure, and the resonant structure includes a plurality of microwave electric field enhancement members 9 arranged on the circumferential outer wall of the atomic gas chamber 1, and the plurality of microwave electric field enhancement members 9 are arranged in a ring around the axis of the atomic gas chamber 1, and each microwave electric field enhancement member 9 is a hollow columnar structure with a fan-shaped cross section, and a cavity 10 is arranged inside each microwave electric field enhancement member 9; the sides of two adjacent microwave electric field enhancement members 9 are connected. Further, the manufacturing material of each microwave electric field enhancement member 9 is copper.

[0022] The physical structure of multiple microwave electric field enhancement components 9 acts as an inductor, and the internal cavity 10 acts as a capacitor. When there is a very small microwave signal in the environment, the microwave electric field will resonate at the contact position between the resonant structure and the atomic gas chamber 1, causing a microwave electric field resonance enhancement effect, which can significantly amplify the microwave electric field intensity in the cavity 10, enhance the response ability of the Rydberg atoms to it, avoid the nonlinear influence of EIT-AT splitting that may exist in the EIT spectrum, and improve the sensitivity of Rydberg atom microwave electric field measurement.

[0023] The first beam splitter 2 and the second beam splitter 3 are respectively arranged on the light incident side and the light exit side of the atomic gas chamber 1, and the third beam splitter 4 is arranged on the top of the atomic gas chamber 1. The refraction direction side of the third beam splitter 4 is provided with a photodetector 5, and the reflection direction of the third beam splitter 4 is toward the position of the first beam splitter 2;

[0024] A detection laser 6 is arranged on one side of the first beam splitter 2. The detection laser 6 emits a detection laser toward the first beam splitter 2. The detection laser is horizontally transmitted through the first beam splitter 2 to reach the second beam splitter 3. The second beam splitter 3 reflects the detection laser and transmits it in the direction of the third beam splitter 4. The detection laser is reflected and refracted by the third beam splitter 4 to reach the first beam splitter 2 and the photodetector 5 respectively.

[0025] A polarization beam splitter prism 7 is also provided on the light emitting side of the atomic gas chamber 1 , and a coupling laser 8 is provided on the top of the polarization beam splitter prism 7 . The coupling laser 8 emits coupling laser toward the polarization beam splitter prism 7 , and the coupling laser passes through the polarization beam splitter prism 7 and is horizontally transmitted to reach the atomic gas chamber 1 .

[0026] When the laser emitted by the detection laser 6 passes through the first beam splitter 2, the second beam splitter 3 and the third beam splitter 4 in sequence, and the post-coupling laser 8 emits the coupling laser toward the polarization beam splitter prism 7, the atomic gas chamber 1 is enhanced, the EIT spectrum peak is enhanced, and the increase in line width caused by simply enhancing the detection laser power is avoided. The detection laser received by the photodetector 5 is used to display the EIT spectrum on the oscilloscope. At the far detuning point of the coupling laser frequency, the circulating light intensity of the detection laser in the atomic gas chamber 1 is the same as the transmission light intensity in free space, and the transmission intensity at other frequencies is normalized by this. When the coupling laser frequency is at the two-photon resonance, the electromagnetically induced transparency and optical pumping effects weaken the absorption of the detection laser by the atoms. These effects reduce the intracavity loss of the atomic gas chamber 1 and improve the impedance matching efficiency of the atomic gas chamber 1, thereby increasing the light intensity entering the atomic gas chamber 1 and enhancing the interaction between the detection laser and the atoms, so the transmission intensity of the detection laser also increases accordingly. Therefore, the transmitted light will be enhanced by cyclic reflection in the atomic gas chamber 1, which improves the accuracy of Rydberg atomic microwave electric field measurement and avoids the disadvantage of increasing the line width due to the enhanced EIT peak value using enhanced laser power.

[0027] Specifically, if the Rydberg atom electric field measurement enhancement device based on the cavity enhancement technology is used to excite the cesium atom from the ground state to the Rydberg state, the wavelength of the detection laser emitted by the detection laser 6 is 852nm, and the detection laser rate is locked to the cesium atom 6S 1 / 2 (F=4)→6P 3 / 2 The wavelength of the coupling laser emitted by the coupling laser 8 is 509 nm, and the scanning frequency of the coupling laser excites the cesium atom from the intermediate state 6P 3 / 2 (F=5) to the Rydberg state (49D 3 / 2 ).

[0028] In summary, the Rydberg atom electric field measurement enhancement device based on cavity enhancement technology in this scheme is used to enhance the EIT spectrum peak while avoiding the increase of line width, and at the same time enhance the perception of Rydberg atoms to extremely small microwave signals, thereby realizing the measurement of extremely small microwave signals and improving the sensitivity and accuracy of Rydberg atom measurements.

Claims

1. Rydberg atom electric field measurement enhancement device based on cavity enhancement technology, characterized in that: It comprises an atomic gas chamber, wherein the outer wall of the atomic gas chamber is provided with a resonant structure, the resonant structure is used to sense microwave signals and generate resonance of natural frequency, a first spectroscope and a second spectroscope are respectively provided on the light incident side and the light exit side of the atomic gas chamber, a third spectroscope is provided on the top of the atomic gas chamber, a photoelectric detector is provided on the refraction direction side of the third spectroscope, and the reflection direction of the third spectroscope is toward the position where the first spectroscope is located; A detection laser is arranged on one side of the first beam splitter. The detection laser emits a detection laser toward the first beam splitter. The detection laser is horizontally transmitted through the first beam splitter to reach the second beam splitter. The second beam splitter reflects the detection laser and transmits it in the direction of the third beam splitter. The detection laser is reflected and refracted by the third beam splitter to reach the first beam splitter and the photoelectric detector respectively.

2. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology according to claim 1 is characterized in that: A polarization beam splitter prism is also provided on the light emitting side of the atomic gas chamber, a coupling laser is provided on the top of the polarization beam splitter prism, and the coupling laser emits coupling laser toward the polarization beam splitter prism, and the coupling laser passes through the polarization beam splitter prism and is horizontally transmitted to reach the atomic gas chamber.

3. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology according to claim 1, characterized in that: The wavelength of the detection laser emitted by the detection laser is 852nm.

4. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology according to claim 2, characterized in that: The wavelength of the coupling laser emitted by the coupling laser is 509 nm.

5. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology according to claim 1, characterized in that: The atomic gas chamber is a hollow columnar structure, and the resonant structure includes a plurality of microwave electric field enhancement components arranged on the circumferential outer wall of the atomic gas chamber. The plurality of microwave electric field enhancement components are arranged in a ring with the axis of the atomic gas chamber as the center, and each microwave electric field enhancement component is a hollow columnar structure with a fan-shaped cross-section, and a cavity is arranged inside each microwave electric field enhancement component; the sides of two adjacent microwave electric field enhancement components are connected.

6. The Rydberg atom electric field measurement enhancement device based on cavity enhancement technology according to claim 5 is characterized in that: The manufacturing material of each microwave electric field enhancement component is copper.

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