Active regulation and control device for microwave resonant cavity based on Rydberg atoms

Abstract

The utility model provides an active regulation and control device for a microwave resonant cavity based on Rydberg atoms. The microwave resonant cavity comprises a protective shell, an atomic gas chamber and a photoelectric detector, the active regulation and control device comprises a PID control module and piezoelectric ceramics, and the PID control module is used for processing a received EIT transmission spectrum signal to generate a deviation correction signal after generating a modulation signal to carry out atomic resonant frequency scanning on the atomic gas chamber; and the piezoelectric ceramic is used for adjusting the length of a protective shell of the microwave resonant cavity according to the received correction signal, so that the atomic resonant frequency is locked as the target resonant frequency. According to the utility model, the resonant frequency of the microwave resonant cavity can be rectified in real time, and the optimal and most stable resonant mode of the local oscillation microwave frequency responding to atoms is maintained.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, specifically to a microwave resonant cavity active control device based on Rydberg atoms. Background Technology

[0002] Currently, high-quality factor microwave cavities are crucial modules for ensuring high sensitivity in electromagnetic signal receiving systems. However, vibrations and temperature variations under complex environmental conditions inevitably affect the geometry of the microwave cavity, thus influencing the resonance conditions of the local oscillator microwave signal field within the cavity, causing the local oscillator microwave signal frequency to shift by several megahertz. However, during high-sensitivity detection, Rydberg atoms exist under extremely narrow EIT linewidth conditions, making them sensitive only to electromagnetic signals in the kilohertz frequency range. When the size of the microwave resonant cavity changes, the microwave resonant frequency of the local oscillator changes, and the Rydberg atoms become less sensitive to the resonant microwave signal within the cavity, thereby affecting the signal receiving sensitivity of the entire system.

[0003] Traditional microwave resonant cavity control employs passive temperature control and vibration isolation schemes, which struggle to suppress high-frequency micro-vibrations and cannot compensate for dynamic drift in real time. Existing technologies rely on overall cooling by a refrigerator, but suffer from high energy consumption, slow response, and inability to dynamically tune, making it difficult to meet the lightweight and real-time requirements of field environments or mobile platforms. Summary of the Invention

[0004] This invention provides an active control device for a microwave resonant cavity based on Rydberg atoms. By combining quantum sensing with PID control, it achieves high-precision locking of the resonant frequency of the microwave resonant cavity and performs real-time correction of the resonant frequency.

[0005] The technical solution provided by this utility model is as follows:

[0006] This invention provides an active control device for a microwave resonant cavity based on Rydberg atoms. The microwave resonant cavity includes:

[0007] The protective housing has a cavity structure.

[0008] The atomic gas chamber is placed inside a protective shell. The probe light and coupling light emitted by the laser frequency locking device are incident on the atomic gas chamber in opposite directions, and Rydberg atoms are prepared inside it. The local oscillator microwave signal emitted by the signal generator is incident on the atomic gas chamber in the direction perpendicular to the probe light.

[0009] The photodetector is located on one side of the protective shell. The probe light emitted from the atomic gas cell is incident on the photodetector. The photodetector receives the probe light and converts it into an EIT transmission spectrum signal. The waveform characteristics of the EIT transmission spectrum signal include the peak value of any signal peak splitting downward to form two EIT transmission peaks and the trough value between the two EIT transmission peaks.

[0010] The active control device includes:

[0011] The PID control module is connected to the photodetector and is used to generate a modulation signal to scan the atomic resonant frequency of the atomic gas cell, and then process the received EIT transmission spectrum signal to generate a correction signal.

[0012] Piezoelectric ceramics are installed on the side wall of the protective housing, which can move back and forth along the direction parallel to the probe light. They are used to adjust the length of the protective housing of the microwave resonant cavity by receiving the correction signal, thereby locking the atomic resonant frequency to the target resonant frequency.

[0013] This invention converts the probe light into an EIT transmission spectrum signal using a photodetector, and the PID control module extracts waveform features and judges the zero-crossing point of the current feedback, thereby realizing real-time acquisition and analysis of spectral information. It also generates a correction signal by using the current value corresponding to the zero-crossing point to drive the shell to extend and retract, locking the atomic resonant frequency to the target value, and finally achieving frequency locking accuracy.

[0014] Preferably, the cavity structure of the protective shell is U-shaped, with its opening located on the other side of the protective shell, and a shell sidewall is movably installed at the opening.

[0015] The piezoelectric ceramic is mounted on the side wall of the housing, and the distance the side wall of the housing moves along the direction of the probe light propagation is controlled by receiving modulation signals and correction signals.

[0016] The atomic gas chamber is filled with alkali metal atoms in a vapor state. After the probe light is incident on the atomic gas chamber, the alkali metal atoms transition from the ground state to the first excited state. After the coupling light is incident on the atomic gas chamber in the opposite direction to the probe light, the alkali metal atoms transition from the first excited state to the Rydberg state. After the local oscillator microwave signal is incident on the atomic gas chamber in the direction perpendicular to the probe light, the atomic gas chamber emits the probe light to the photodetector.

[0017] The technical effects of this utility model are as follows:

[0018] This invention, through real-time monitoring and feedback of EIT spectra, can suppress cavity length changes caused by environmental temperature drift and vibration, thus meeting the requirements for lightweight design.

[0019] The microwave resonant cavity active control device based on Rydberg atoms described in this invention can achieve frequency locking of the microwave resonant cavity by combining EIT transmission spectroscopy with PID control, and the frequency locking accuracy is high. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the structure of a microwave resonant cavity active control device based on Rydberg atoms, as described in an embodiment of this utility model.

[0021] In the attached diagram, 1-protective shell, 2-atomic gas chamber, 3-shell sidewall, 4-piezoelectric ceramic, 5-photodetector. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0023] As attached Figure 1 As shown, a microwave resonant cavity active control device based on Rydberg atoms is disclosed, wherein the microwave resonant cavity includes a protective shell 1, an atomic gas chamber 2, and a photodetector 5.

[0024] The cavity structure of the protective housing 1 is U-shaped, with its opening located on the right side of the protective housing 1, and a housing sidewall 3 is movably installed at the opening.

[0025] Atomic gas chamber 2 is housed within a protective shell and is filled with alkali metal atoms in a vapor state. When the probe light is incident on the atomic gas chamber 2, the alkali metal atoms transition from the ground state to the first excited state. When the coupling light is incident on the atomic gas chamber 2 in the opposite direction to the probe light, the alkali metal atoms transition from the first excited state to the Rydberg state. After the local oscillator microwave signal (LO signal) is incident on the atomic gas chamber 2 in the direction perpendicular to the probe light, the atomic gas chamber 2 emits the probe light to the photodetector 5. In this embodiment, the probe light wavelength is 852 nm and the coupling light wavelength is 509 nm. When the probe light and the coupling light act together on the alkali metal atoms, the EIT effect occurs—the absorption of the probe light by the atoms is suppressed, and the intensity of the transmitted light is enhanced. When the local oscillator microwave signal interacts with the Rydberg atoms, it modulates the shape of the EIT spectrum, causing it to exhibit a characteristic splitting phenomenon. Specifically, the original single signal peak splits downward into two EIT transmission peaks, with a trough forming between the two peaks. Secondly, parameters such as the trough bottom value, the peak value of the two peaks, and the spacing directly reflect the resonance state between the alkali metal atoms and the microwave field.

[0026] A photodetector 5 is located on one side of the protective housing. The photodetector 5 receives the probe light and converts it into an EIT transmission spectrum signal, which is then output to the active control device. In this embodiment, the photodetector 5 captures the transmission intensity of the probe light at a sampling rate greater than or equal to 100 kSa / s, and then outputs the EIT transmission spectrum signal to the active control device. In this embodiment, the EIT transmission spectrum signal is a voltage signal that characterizes the intensity of the measured probe light.

[0027] The active control device includes a PID control module and a piezoelectric ceramic 4. The piezoelectric ceramic 4 is mounted on the side wall of the protective housing 1, which can move back and forth along the direction parallel to the probe light.

[0028] The PID control module is used to scan the atomic resonant frequency of the atomic gas chamber 2 by generating a modulation signal, process the received EIT transmission spectrum signal, obtain the target resonant frequency by the zero-crossing point of the current feedback corresponding to the valley value of the EIT transmission spectrum, and generate a correction signal. In this embodiment, the modulation signal is a triangular wave current signal, and its frequency is preferably 10Hz, the purpose of which is to obtain the resonant frequency value of the microwave resonant cavity.

[0029] The piezoelectric ceramic 4, acting as an actuator, receives the correction signal and then adjusts the length of the protective shell 1 of the microwave resonant cavity, thereby locking the atomic resonant frequency to the target resonant frequency. In this embodiment, the correction signal is a current-driven signal with a current magnitude within the range of ±5mA. Furthermore, the piezoelectric ceramic 4 is adhered to the outer wall of the resonant cavity shell sidewall 3, and its inverse piezoelectric effect drives the shell to extend and retract axially, achieving adjustment of the resonant frequency of the microwave resonant cavity.

[0030] The process of the active control device for microwave resonant cavity is as follows:

[0031] 1. The 852nm probe light and 509nm coupling light emitted by the laser frequency locking device are incident on the atomic gas cell 2 in opposite directions, causing the cesium atom to transition from the ground state to the Rydberg state;

[0032] 2. The signal generator outputs a local oscillator microwave signal (LO signal), which is incident on the atomic gas cell 2 from a direction perpendicular to the probe light. The atomic gas cell 2 outputs a probe light carrying EIT spectral information to the photodetector 5.

[0033] 3. The photodetector 5 converts the probe light into an EIT transmission spectrum signal and outputs it to the PID control module;

[0034] 4. The modulation signal generation unit in the PID control module generates a 10Hz triangular wave modulation signal, which drives the piezoelectric ceramic 4 to periodically adjust the cavity length of the microwave resonant cavity and scan the resonant frequency range of the microwave resonant cavity.

[0035] 5. The PID control module generates a correction signal based on the base current and the optimal resonant point current of the modulation signal, which drives the piezoelectric ceramic 4 to move the side wall 3 of the housing left and right, thereby adjusting the cavity length of the micro-resonant cavity and locking the atomic resonant frequency to the target resonant frequency value. The current correction signal is ±5mA current, and the target resonant frequency value is 2.5GHz.

Claims

1. A microwave resonant cavity active control device based on Rydberg atoms, characterized in that, The microwave resonant cavity includes: A protective housing, wherein the protective housing has a cavity structure; An atomic gas chamber is placed inside a protective shell. The probe light and coupling light emitted by the laser frequency locking device are incident on the atomic gas chamber in opposite directions to prepare Rydberg atoms. The local oscillator microwave signal emitted by the signal generator is incident on the atomic gas chamber in the direction perpendicular to the probe light. A photodetector is located on one side of the protective shell. The probe light emitted from the atomic gas cell is incident on the photodetector, which receives the probe light and converts it into an EIT transmission spectrum signal. The active control device includes: The PID control module is communicatively connected to the photodetector and is used to process the received EIT transmission spectrum signal and generate a correction signal. Piezoelectric ceramics are mounted on the sidewall of the protective housing on the other side, which can move back and forth along the direction parallel to the probe light, and are used to adjust the length of the protective housing of the microwave resonant cavity by means of a correction signal.

2. The microwave resonant cavity active control device based on Rydberg atoms as described in claim 1, characterized in that, The cavity structure of the protective shell is U-shaped, with its opening located on the other side of the protective shell, and a shell sidewall is movably installed at the opening; The piezoelectric ceramic is mounted on the side wall of the housing, and the distance the side wall of the housing moves along the direction of the probe light propagation is controlled by receiving modulation signals and correction signals.

3. The microwave resonant cavity active control device based on Rydberg atoms as described in claim 1 or 2, characterized in that, The atomic gas chamber is filled with alkali metal atoms in a vapor state. When the probe light is incident on the atomic gas chamber, the alkali metal atoms transition from the ground state to the first excited state. After the coupling light and the probe light are incident on the atomic gas cell in opposite directions, the alkali metal atom transitions from the first excited state to the Rydberg state; After the local oscillator microwave signal is incident on the atomic gas cell in the direction perpendicular to the probe light, the probe light emitted from the atomic gas cell is sent to the photodetector.

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