Microwave detection device and method of fiber integrated rydberg atom

Abstract

The application provides a microwave detection device and method for fiber integrated Rydberg atoms, which comprises an optical excitation module, a bubble echo-wall microcavity, a microwave coupling module, a light splitting module, a signal conditioning module and a main control module; a tapered optical fiber is used to couple the near field of the combined light formed by the detection light and the coupling light into the bubble microcavity, so that the combined light field circulates and propagates in the echo-wall mode and fully interacts with the alkali metal atom vapor to excite a stable EIT spectrum; the microwave coupling module is used to converge the microwave to be detected into the bubble microcavity, and resonates with the atoms in the Rydberg state in the bubble microcavity to induce energy level splitting, so as to modulate the light field transmittance; the signal conditioning module is used to convert the transmitted light led out by the tapered optical fiber from an optical signal into an electrical signal, and extract the spectral characteristics of the microwave to be detected from the electrical signal; and the main control module is used to determine the microwave parameters of the microwave to be detected based on the spectral characteristics. The application improves the detection stability and detection sensitivity of the microwave detection device.

Description

Technical Field

[0001] This invention relates to the field of microwave detection technology, and in particular to a microwave detection device and method for fiber-optic integrated Rydberg atoms. Background Technology

[0002] Microwave detection technology is a core support for fields such as electronic reconnaissance, stealth target identification, and communication monitoring. Traditional electrical detection methods are limited by electronic thermal noise and the "electronic bottleneck," making it difficult to meet the high-precision detection requirements of weak microwave signals. Microwave detection technology based on Rydberg atoms, with its quantum-level sensitivity and wide-spectrum response characteristics, has become a key direction for breaking through the bottlenecks of traditional technologies.

[0003] Related Rydberg atom microwave detection devices typically use traditional atomic gas cells as the interaction carrier, and introduce lasers to excite Rydberg atoms through free space optical paths. Although they have the advantage of large bandwidth, they have inherent defects. The interaction time between light and atoms is short and the interaction efficiency is low, which limits the sensitivity and makes it difficult to meet the high-precision detection requirements of weak microwave signals. In addition, the atomic gas cell is large in volume and the interaction area between the light field and atoms is dispersed, which further weakens the interaction intensity, resulting in low detection stability and detection sensitivity of the microwave detection device. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a microwave detection device and method for fiber-optic integrated Rydberg atoms, which can meet the high-precision detection requirements of weak microwave signals and improve the detection stability and detection sensitivity of the microwave detection device.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows: In a first aspect, embodiments of the present invention provide a microwave detection device for fiber-optic integrated Rydberg atoms, comprising: an optical excitation module, a bubble whispering-gallery microcavity, a microwave coupling module, a beam splitting module, a signal conditioning module, and a main control module; The optical excitation module includes a probe laser and a coupling laser; the bubble whispering wall microcavity includes a near-field coupling structure composed of a bubble microcavity and a tapered optical fiber, wherein the bubble microcavity is a sealed gas chamber and is filled with alkali metal atomic vapor; The two ends of the tapered optical fiber are connected to the probe laser and the coupling laser, respectively, and the beam splitting module is connected between the coupling laser and the tapered optical fiber; The tapered optical fiber is used to near-field couple the combined beam formed by the probe light emitted by the probe laser and the coupling light emitted by the coupling laser into the bubble microcavity, so that the combined beam light field circulates in a whispering-gallery mode and fully interacts with the alkali metal atom vapor to excite and form a stable EIT spectrum; wherein, the probe light excites the alkali metal atoms from the ground state to the first excited state, and the coupling light excites the alkali metal atoms from the first excited state to the Rydberg state; The microwave coupling module is used to focus the microwave to be measured into the bubble microcavity, and induce energy level splitting by resonance with the atoms of the Rydberg state in the bubble microcavity, so as to modulate the light field transmittance. The beam splitting module is used to transmit the transmitted light emanating from the tapered optical fiber to the signal conditioning module; The signal conditioning module is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal, and to extract the spectral characteristics of the microwave under test from the electrical signal. The main control module is used to determine the microwave parameters of the microwave under test based on the spectral characteristics; wherein the microwave parameters include microwave frequency, microwave intensity and microwave phase.

[0006] Furthermore, the present invention provides a first possible implementation of the first aspect, wherein the signal conditioning module includes a photodetector, a lock-in amplifier, a spectrum analyzer, and a power meter; The photodetector is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal; The lock-in amplifier is used for noise reduction processing of the electrical signal; The spectrum analyzer is used to acquire and identify the split frequency and split amplitude of the split EIT spectrum based on the noise-reduced electrical signal; The power meter is used to acquire power data of the split EIT spectrum based on the noise-reduced electrical signal.

[0007] Furthermore, the present invention provides a second possible implementation of the first aspect, wherein the main control module is further configured to determine the microwave frequency, microwave intensity and microwave phase of the microwave under test based on the splitting frequency, the splitting amplitude, the power data and the microwave parameter inversion model.

[0008] Furthermore, the present invention provides a third possible implementation of the first aspect, wherein the microwave coupling module includes a miniature focusing antenna, an impedance matching unit, and a microcavity fixing bracket; The miniature focusing antenna is disposed on the outer wall of the bubble whispering wall microcavity, and the focal point of the miniature focusing antenna coincides with the center point of the bubble microcavity; The impedance matching unit is integrated into the feed terminal of the miniature focusing antenna; The microcavity mounting bracket is used to fix the micro-focusing antenna to the outer wall of the bubble echo wall microcavity.

[0009] Furthermore, the present invention provides a fourth possible implementation of the first aspect, wherein the bubble microcavity is a sealed gas chamber prepared based on fused silica material, the bubble microcavity is located directly above the tapered optical fiber, and the coupling distance between the bubble microcavity and the tapered optical fiber ranges from 0.5 to 2 μm.

[0010] Furthermore, the present invention provides a fifth possible implementation of the first aspect, wherein the bubble echo wall microcavity further includes a coupling structure support, a sealing structure, a micro heating element, a temperature sensor, and a packaging component; The sealing structure is fixed at both ends of the bubble microcavity, and the micro heating element and the temperature sensor are disposed on the outside of the bubble microcavity; The coupling structure support is used to fix the coupling structure composed of the bubble microcavity and the tapered optical fiber, so that the relative position of the bubble microcavity and the tapered optical fiber remains unchanged. The encapsulation component is used to seal the coupling structure support within the bubble echo wall microcavity so that the relative position of the coupling structure and the coupling structure support remains unchanged.

[0011] Furthermore, this embodiment of the invention provides a sixth possible implementation of the first aspect, wherein the microwave detection device further includes: an optical fiber coupler, a polarization-maintaining optical fiber, and an optical polarization controller; the optical fiber coupler is disposed at both ends of the tapered optical fiber; The two ends of the tapered optical fiber are respectively connected to the probe laser and the coupling laser via the polarization-maintaining optical fiber; The optical polarization controller is used to adjust the probe light and coupling light entering the tapered optical fiber to a polarization state to match the polarization requirements of the bubble microcavity whispering gallery mode.

[0012] Furthermore, this embodiment of the invention provides a seventh possible implementation of the first aspect, wherein the beam splitting module includes a dichroic mirror or a wavelength division multiplexer; And / or, The main control module is also used to control the micro heating plate on the outside of the bubble microcavity to heat the temperature inside the bubble microcavity to a set temperature before starting the photoexcitation module, and simultaneously trigger the optical polarization controller to adjust the laser polarization state to TE when starting the photoexcitation module. 01 model.

[0013] In a second aspect, embodiments of the present invention also provide a microwave detection method for fiber-integrated Rydberg atoms, applied to the microwave detection device for fiber-integrated Rydberg atoms as described in any one of the first aspects, wherein the microwave detection method for fiber-integrated Rydberg atoms includes: The optical excitation module is activated, and probe light is emitted from the probe laser and incident on the tapered optical fiber, and coupling light is emitted from the coupling laser and incident on the tapered optical fiber; The probe light emitted by the probe laser and the coupling light emitted by the coupling laser are coupled in the near field into the bubble microcavity based on the tapered optical fiber, so that the combined light field propagates cyclically in a whispering-gallery mode and fully interacts with the alkali metal atom vapor to excite and form a stable EIT spectrum; wherein, the probe light excites the alkali metal atoms from the ground state to the first excited state, and the coupling light excites the alkali metal atoms from the first excited state to the Rydberg state; The microwave coupling module focuses the microwave to be measured into the bubble microcavity, and the energy level splitting is triggered by the atomic resonance of the Rydberg state in the bubble microcavity to modulate the light field transmittance. The transmitted light from the tapered optical fiber is transmitted to the signal conditioning module based on the beam splitting module; The signal conditioning module converts the transmitted light from the tapered optical fiber into an electrical signal and extracts the spectral characteristics of the microwave under test from the electrical signal. The microwave parameters of the microwave to be measured are determined based on the spectral characteristics; wherein the microwave parameters include microwave frequency, microwave intensity and microwave phase.

[0014] Furthermore, the microwave detection method further includes: Before activating the photoexcitation module, the micro-heating plate on the outside of the bubble microcavity is controlled to heat the temperature inside the bubble microcavity to a set temperature. When the photoexcitation module is activated, the optical polarization controller is simultaneously triggered to adjust the laser polarization state to TE. 01 model.

[0015] This invention provides a microwave detection device and method for integrating Rydberg atoms in optical fibers. The device includes: an optical excitation module, a bubble whispering-gallery microcavity, a microwave coupling module, a beam splitting module, a signal conditioning module, and a main control module. The optical excitation module includes a probe laser and a coupling laser. The bubble whispering-gallery microcavity includes a near-field coupling structure composed of a bubble microcavity and a tapered optical fiber. The bubble microcavity is a sealed gas chamber filled with alkali metal atom vapor. The two ends of the tapered optical fiber are connected to the probe laser and the coupling laser, respectively. The beam splitting module is connected between the coupling laser and the tapered optical fiber. The tapered optical fiber is used to near-field couple the combined beam formed by the probe light emitted by the probe laser and the coupling light emitted by the coupling laser into the bubble microcavity, so that the combined beam's optical field returns to its original position. A stable EIT spectrum is formed by the cyclic propagation of the sounding-gallery mode and the full interaction of alkali metal atomic vapor. The probe light excites alkali metal atoms from their ground state to a first excited state, which in turn excites them from the first excited state to a Rydberg state. A microwave coupling module focuses the microwave to be measured into a bubble microcavity, where it resonates with the Rydberg atoms to induce energy level splitting, thereby modulating the light field transmittance. A beam splitting module transmits the transmitted light from the tapered optical fiber to a signal conditioning module. The signal conditioning module converts the transmitted light from the tapered optical fiber into an electrical signal and extracts the spectral characteristics of the microwave to be measured from the electrical signal. A main control module determines the microwave parameters of the microwave to be measured based on the spectral characteristics, including microwave frequency, microwave intensity, and microwave phase. This invention constructs a bubble whispering-gallery microcavity based on a coupling structure of tapered optical fiber and bubble microcavity. This allows the combined beam of the probe light and coupling light to propagate cyclically in a whispering-gallery mode, thereby enabling it to fully interact with alkali metal atomic vapor, improving the interaction efficiency and intensity. By determining the microwave frequency, microwave intensity, and microwave phase of the microwave to be measured based on the spectral characteristics of the transmitted light derived from the tapered optical fiber, the light-atom interaction time is extended by utilizing the light field enhancement effect of the whispering-gallery mode. This meets the high-precision detection requirements for weak microwave signals and improves the detection stability and detection sensitivity of the microwave detection device.

[0016] Other features and advantages of the embodiments of the present invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above in the embodiments of the present invention.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This diagram illustrates a microwave detection device with fiber-optic integrated Rydberg atoms provided in an embodiment of the present invention. Figure 2 This figure shows a top view of a bubble echo wall microcavity provided in an embodiment of the present invention; Figure 3 A flowchart of a microwave detection method for fiber-optic integrated Rydberg atoms provided by an embodiment of the present invention is shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0021] This embodiment provides a microwave detection device for fiber-optic integrated Rydberg atoms, see below. Figure 1 The schematic diagram of the microwave detection device with fiber-optic integrated Rydberg atoms shown includes: an optical excitation module, a bubble whispering-gallery microcavity 20, a microwave coupling module 30, a beam splitting module 40, a signal conditioning module 50, and a main control module 60. The optical excitation module includes a probe laser 11 and a coupling laser 12; the bubble whispering wall microcavity 20 includes a coupling structure consisting of a bubble microcavity 21 and a tapered optical fiber 22, wherein the bubble microcavity 21 is a sealed gas chamber and is filled with alkali metal atom vapor. The two ends of the tapered optical fiber 22 are connected to the probe laser 11 and the coupling laser 12, respectively, and the beam splitting module 40 is connected between the coupling laser 12 and the tapered optical fiber 22. The tapered optical fiber 22 is used to couple the combined beam formed by the probe light emitted by the probe laser 11 and the coupling light emitted by the coupling laser 12 into the bubble microcavity 21 in the near field, so that the combined beam light field propagates in a whispering-gallery mode and fully interacts with the alkali metal atom vapor to excite and form a stable EIT spectrum; wherein, the probe light excites the alkali metal atoms from the ground state to the first excited state, and the coupling light excites the alkali metal atoms from the first excited state to the Rydberg state; The bubble whispering-gallery microcavity 20 is the core carrier of light-atom-microwave interaction. The bubble microcavity 21 is filled with alkali metal atom vapor and buffer gas. In order to ensure the structural stability of the coupling structure formed by the bubble microcavity 21 and the tapered optical fiber 22, an encapsulation process (such as UV glue or other fixative processes) can be used to fix the coupling structure formed by the bubble microcavity 21 and the tapered optical fiber 22, thereby achieving optical field enhancement through the whispering-gallery mode.

[0022] The aforementioned bubble microcavity 21 can be made of fused silica material, with an inner diameter of 50-200 μm and a wall thickness of 5-10 μm. The bubble microcavity 21 is filled with cesium or rubidium atom vapor and a mixed buffer gas composed of neon and helium, with a buffer gas pressure of 0.05-0.15 MPa.

[0023] Both the probe laser 11 and the coupling laser 12 are narrow-linewidth semiconductor lasers (linewidth ≤ 1 kHz) to ensure wavelength stability.

[0024] The microwave coupling module 30 is used to focus the microwave to be measured into the bubble microcavity, and induce energy level splitting by resonance with the Rydberg state atoms in the bubble microcavity to modulate the light field transmittance. The microwave coupling module 30 is used to converge the microwave signal to be measured, so that the microwave field is efficiently coupled with the Rydberg atoms in the bubble microcavity 21.

[0025] The beam splitter module 40 is used to transmit the transmitted light from the tapered optical fiber to the signal conditioning module; The signal conditioning module 50 is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal and extract the spectral characteristics of the microwave under test from the electrical signal. The main control module 60 is used to determine the microwave parameters of the microwave under test based on spectral characteristics; wherein, the microwave parameters include microwave frequency, microwave intensity and microwave phase.

[0026] In one embodiment, the aforementioned bubble microcavity 21 is filled with cesium atomic vapor. The probe wavelength of the cesium atomic vapor microcavity is 852 nm, the coupling wavelength is 509 nm, and the whispering-gallery mode light field enhancement factor is ≥50 times. After UV adhesive curing, the coupling position drift is ≤±0.1 μm / 24h. The spectral splitting distance is positively correlated with the microwave field strength by ≥0.995. The main control module quickly inverts parameters through a pre-calibrated model, with an inversion time of ≤1 ms.

[0027] The microwave detection device integrating Rydberg atoms in the optical fiber provided in this embodiment constructs a bubble whispering-gallery microcavity based on a coupling structure of tapered optical fiber and bubble microcavity. This allows the combined beam of the probe light and the coupling light to propagate cyclically in whispering-gallery mode, thereby enabling it to fully interact with alkali metal atom vapor, improving the interaction efficiency and intensity. The microwave frequency, microwave intensity, and microwave phase of the microwave to be measured are determined based on the spectral characteristics of the transmitted light emanating from the tapered optical fiber. Since the whispering-gallery mode enhances the optical field, it can meet the high-precision detection requirements of weak microwave signals, improving the detection stability and detection sensitivity of the microwave detection device.

[0028] In one implementation, such as Figure 1 As shown, the signal conditioning module 50 provided in this embodiment includes a photodetector 51, a lock-in amplifier 52, a spectrum analyzer 53, and a power meter 54; The photodetector 51 is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal; the photodetector 51 can be an avalanche photodetector, which (response wavelength 700-900nm, responsivity ≥0.9A / W) converts weak optical signals into electrical signals. The lock-in amplifier 52 (noise floor ≤ 0.8nV / √Hz) is used to perform noise reduction processing on electrical signals and extract weak signal features; The spectrum analyzer 53 is used to acquire and identify the splitting frequency and splitting amplitude of the split EIT spectrum based on the noise-reduced electrical signal; Power meter 54 is used to acquire power data of the split EIT spectrum based on the noise-reduced electrical signal.

[0029] The aforementioned signal conditioning module 50 may further include an optical fiber isolator, which is located at the lead-out end of the tapered optical fiber. The optical fiber isolator (isolation ≥ 35 dB) suppresses interference of reflected light on the laser. A spectrum analyzer (0-2 GHz) and a power meter (accuracy ± 0.01 dBm) acquire spectral splitting characteristics and power data to provide a basis for parameter inversion.

[0030] Transmitted light within the bubble microcavity is guided out via a tapered optical fiber. After reflection interference is suppressed by an optical fiber isolator, it is input to a photodetector and converted into an electrical signal. The electrical signal undergoes noise reduction processing by a lock-in amplifier to remove environmental and circuit noise, and is then transmitted to a spectrum analyzer and a power meter, respectively. The spectrum analyzer acquires the EIT spectrum after splitting, identifies the splitting frequency (consistent with the microwave frequency) and the splitting amplitude (positively correlated with the microwave intensity), and the power meter acquires real-time power data.

[0031] In one embodiment, the main control module provided in this embodiment is also used to determine the microwave frequency, microwave intensity and microwave phase of the microwave to be measured based on the splitting frequency, splitting amplitude, power data and microwave parameter inversion model.

[0032] The main control module adopts an FPGA+ARM dual-core architecture (FPGA XC7K325T+ARM STM32H743), with built-in optimization algorithms and inversion models. On the one hand, it adjusts the laser power, polarization state, bubble microcavity temperature and coupling parameters, and on the other hand, it quickly processes the acquired data. Based on the Autler-Townes splitting law, it inverts the microwave frequency, intensity and phase, with an inversion time of ≤1ms, which meets the real-time detection requirements.

[0033] The main control module retrieves microwave parameters based on the Autler-Townes splitting law. It calls a pre-calibrated model, determines the microwave frequency through the splitting frequency, calculates the microwave intensity based on the correlation between splitting amplitude and power data, and retrieves the microwave phase using spectral phase shift, thus completing precise parameter measurements. The main control module continuously monitors the EIT spectral stability and signal-to-noise ratio. When environmental disturbances cause spectral fluctuations exceeding ±0.3%, it dynamically adjusts the polarization state of the tapered fiber and the temperature of the bubble microcavity (adjustment accuracy ±0.1℃) to compensate for the attenuation of photo-atomic interaction efficiency. Simultaneously, it corrects impedance matching parameters to ensure stable microwave coupling efficiency and maintain optimal detection accuracy.

[0034] In one embodiment, the microwave coupling module provided in this embodiment includes a miniature focusing antenna, an impedance matching unit, and a microcavity fixing bracket; The miniature focusing antenna is disposed on the outer wall of the bubble whispering wall microcavity, and the focal point of the miniature focusing antenna coincides with the center point of the bubble microcavity. The miniature focusing antenna can be fabricated by copper foil electroplating process and is attached to the outer side of the bubble microcavity encapsulation component. The antenna focal point coincides with the center of the microcavity, which focuses the spatial microwave signal into a local strong electric field, and the electric field strength is enhanced by ≥3 times. The impedance matching unit is integrated into the feed terminal of the miniature focusing antenna; the impedance matching unit has a built-in 50Ω thin film resistor to reduce microwave reflection loss and enable the detection bandwidth to cover 0.1GHz-600GHz.

[0035] The microcavity mounting bracket is used to fix the miniature focusing antenna to the outer wall of the bubble whispering wall microcavity. The microcavity mounting bracket can be made of quartz material, and the packaged components and the miniature focusing antenna are simultaneously fixed by photolithographic positioning grooves to ensure that the overlap between the microwave field and the optical field inside the bubble microcavity is ≥92%, thus avoiding efficiency degradation.

[0036] The microwave signal under test is focused by a miniature focusing antenna and acts perpendicularly on the outside of the packaged component. The microwave field penetrates the encapsulation adhesive layer and the microcavity wall, entering the interior and resonating with Rydberg atoms. The extremely large electric dipole moment of the Rydberg atoms causes Autler-Townes splitting of the atomic energy levels. The degree of splitting varies with the microwave frequency and intensity, thereby modulating the transmittance of the whispering-gallery mode optical field. This allows the transmitted light signal to carry microwave parameter information, achieving efficient conversion of microwave signals into optical signals.

[0037] In one embodiment, the bubble microcavity provided in this example is a sealed gas chamber prepared based on fused silica material, such as... Figure 1 As shown, the bubble microcavity 21 is located directly above the tapered optical fiber 22, and the coupling distance h between the bubble microcavity 21 and the tapered optical fiber 22 ranges from 0.5μm to 2μm.

[0038] In one embodiment, the bubble echo wall microcavity provided in this embodiment further includes a coupling structure support, a sealing structure, a micro heating element, a temperature sensor, and a packaging component; The sealing structure is fixed at both ends of the bubble microcavity, and the micro heating element and temperature sensor are set on the outside of the bubble microcavity; The aforementioned bubble microcavities can be spherical or ellipsoidal. The sealing structure can be fabricated using a glass-metal brazing process and fixed to both ends of the bubble microcavity. The sealing accuracy of the sealing structure is ≤10. -9 Pa·m³ / s. The micro heating element and temperature sensor are attached to the outside of the bubble microcavity. The micro heating element is controlled in a closed loop by the main control module (i.e., the main control module obtains the temperature detection value of the temperature sensor and controls the micro heating element to heat the microcavity so that the temperature inside the microcavity is stabilized near the set temperature), and the temperature inside the microcavity is stabilized at 40-75℃.

[0039] The coupling structure support is used to fix the coupling structure composed of the bubble microcavity and the tapered optical fiber, so that the relative position of the bubble microcavity and the tapered optical fiber remains unchanged; The encapsulation component is used to seal the coupling structure support within the bubble echo wall microcavity so that the relative position of the coupling structure and the coupling structure support remains unchanged.

[0040] The microcavity body can be made of high-purity fused silica, with an inner diameter of 50-200 μm and a wall thickness of 5-10 μm, ensuring stable formation of the whispering gallery mode while facilitating microwave field penetration. It is filled with a buffer gas mixture of cesium / rubidium atomic vapor and neon-helium (volume ratio 4:1, pressure 0.05-0.15 MPa). This buffer gas suppresses atomic collision relaxation, extending the energy level lifetime to over 100 μs. The sealing structure can employ glass-metal brazing to ensure long-term stability of the atomic vapor concentration. A micro-heating element (such as a ceramic heating element with a power of 0-3 W) and a high-precision temperature sensor (accuracy ±0.1℃) are attached to the outside of the microcavity, with closed-loop temperature control via a main control module.

[0041] The encapsulation component can use low-refractive-index UV adhesive MY133 to cover the coupling area. This adhesive has a refractive index of 1.33, which can reduce light field loss. After curing by UV lamp irradiation for 10 minutes, the cover glass and glass gasket form a protective structure to wrap and protect the cured coupling structure. Teflon tubes at both ends of the microcavity are used for gas filling and subsequent sealing maintenance, effectively suppressing coupling position drift, so that the drift amount in 24 hours is ≤±0.1μm.

[0042] The aforementioned coupling structure support can be a 3D-printed glass frame, with the tapered optical fiber fixed by the 3D-printed glass frame and a UV-coated encapsulation structure maintaining the stability of the coupling position. The tapered optical fiber is prepared by laser melting and stretching (4mm in tapered region length and 3μm in end diameter), fixed by the 3D-printed glass frame, and the coupling distance between it and the outer wall of the bubble microcavity is controlled at 0.5-2μm to achieve efficient near-field coupling.

[0043] In one embodiment, the tapered optical fiber can be prepared by laser melting and stretching process, with a tapered region length of 4 mm and an end diameter of 3 μm. The tapered optical fiber is fixed on a 3D printed glass frame, which can be pre-positioned with positioning grooves by photolithography process, with a positioning accuracy of ±0.05 μm. After encapsulation, the coupling structure is fixed: the relative position of the bubble microcavity and the tapered optical fiber is adjusted by a micro-displacement platform until the bubble microcavity and the tapered optical fiber reach a critical coupling state; quartz clamps are used to fix both ends of the bubble microcavity to ensure the relative position of the bubble microcavity and the tapered optical fiber is stable; low refractive index UV adhesive MY133 (refractive index 1.33) is filled into the coupling structure area of ​​the bubble microcavity and the tapered optical fiber to completely cover the coupling area, and a cover glass and a glass gasket are placed on top to form a protective cavity. After being irradiated under a UV lamp for a period of time, it is cured. After curing, the drift of the coupling position is ≤ ±0.1μm after 24 hours; Teflon tubes are connected to both ends of the bubble microcavity, and cesium atomic vapor and mixed buffer gas (neon:helium = 4:1, pressure 0.1MPa) are injected through the tubes. After injection, the Teflon tubes are sealed to maintain a stable atomic vapor concentration in the cavity.

[0044] For example, see... Figure 2 The diagram shows a top view of the bubble whispering wall microcavity 20. The bubble whispering wall microcavity 20 includes a bubble microcavity 21, a tapered optical fiber 22, and a coupling structure support 23. The coupling structure support 23 has multiple positioning grooves 24, and sealing structures 25 are fixed to both ends of the bubble microcavity 21. The bubble microcavity 21 is located directly above the tapered optical fiber 22, and the extension direction of the tapered optical fiber 22 is perpendicular to the extension direction of the sealing structures 25 at both ends of the bubble microcavity 21. The positioning grooves 24 are used to fix the relative positions of the bubble microcavity 21 and the tapered optical fiber 22, so that the coupling distance between the outer wall of the bubble microcavity 21 and the tapered optical fiber 22 is controlled within 0.5-2 μm, thereby achieving efficient near-field coupling.

[0045] In one embodiment, the microwave detection device provided in this embodiment further includes: an optical fiber coupler, a polarization-maintaining optical fiber, and an optical polarization controller; the optical fiber coupler is disposed at both ends of the tapered optical fiber; The two ends of the tapered optical fiber are connected to the probe laser and the coupling laser respectively via polarization-maintaining optical fibers; The optical polarization controller is used to adjust the probe light and coupling light entering the tapered optical fiber to the polarization state to match the polarization requirements of the bubble microcavity whispering gallery mode.

[0046] The polarization-maintaining fiber can be a panda-type structure (loss ≤ 0.2dB / km), with a transmission loss of 0.18dB / km, effectively suppressing polarization distortion; the optical polarization controller can be an electro-optic modulation type (response speed ≤ 0.8ms), with a response speed of 0.6ms, precisely adjusting the laser polarization state to TE. 01 The whispering-gallery mode ensures maximum coupling efficiency. The fiber coupler can be a 1×2 combiner, with a working wavelength range of 500-860nm and a combining loss of 2%, which combines two laser beams and transmits them to a tapered fiber.

[0047] The probe laser outputs a laser whose wavelength matches the transition from the ground state to the first excited state of an alkali metal atom, and the coupling laser outputs a laser whose wavelength matches the transition from the first excited state to the Rydberg state. The two lasers are transmitted to the optical polarization controller via polarization-maintaining fibers, and the optical polarization controller adjusts the polarization state to match the polarization requirements of the bubble microcavity whispering gallery mode.

[0048] The fiber coupler combines the probe light and the coupling light and transmits them to a tapered fiber. The diameter of the tapered fiber gradually changes to 2μm-4μm at the end. The coupling distance between the fiber and the outer wall of the bubble whispering wall microcavity is controlled at 0.5μm-2μm, realizing near-field coupling of optical signals with a coupling efficiency of ≥88% and a whispering wall mode lifetime of ≥10μms in the bubble microcavity.

[0049] In one embodiment, the beam splitting module provided in this embodiment includes a dichroic mirror or a wavelength division multiplexer.

[0050] For example, this embodiment provides an experiment on microwave detection based on the above-described microwave detection device integrating Rydberg atoms in optical fibers: System initialization and packaging verification: Power on each module, the main control module adjusts the power and polarization state of the probe light and coupling light, and the spectral signal is monitored through the signal demodulation module to confirm that the whispering gallery mode is stably formed and the intensity fluctuation of the EIT spectral transmission peak is ≤±0.3%; the stability of the packaging structure is tested. Under the environment of room temperature 25℃±1℃ and vibration amplitude ≤0.1g, continuous monitoring for 24 hours shows that the coupling position drift is 0.08μm, which meets the detection stability requirements.

[0051] Microwave detection and signal coupling: A weak microwave signal with a frequency of 3.6 GHz and an intensity of 0.5 μV / cm is applied. This signal is generated by an RF signal source and transmitted to a miniature focusing antenna. The miniature focusing antenna focuses the microwave signal to the central region of the bubble whispering-gallery microcavity. The microwave field penetrates the UV encapsulation layer and the microcavity wall, entering the bubble microcavity and resonating with Rydberg cesium atoms. Due to the extremely large electric dipole moment of Rydberg atoms, the microwave field induces Autler-Townes splitting of the atomic energy levels. The splitting frequency is consistent with the microwave frequency (3.6 GHz), and the splitting amplitude is linearly positively correlated with the microwave intensity, thereby modulating the transmittance of the whispering-gallery mode light field, allowing the transmitted light signal to carry microwave parameter information.

[0052] The transmitted light within the microcavity is guided out via a tapered optical fiber. After reflection interference is suppressed by an optical fiber isolator, it is input to the avalanche photodetector and converted into an electrical signal. The electrical signal is then processed by a lock-in amplifier to remove environmental and circuit noise before being transmitted to a spectrum analyzer and a power meter, respectively. The spectrum analyzer acquires the split EIT spectrum, identifies the split frequency as 3.6 GHz, and determines the microwave frequency. The power meter acquires real-time power data and, combined with a pre-calibrated model (fitting equation y = 0.52x + 0.003, R² = 0.996), calculates the microwave intensity to be 0.5 μV / cm. The main control module, based on the spectral phase shift, inverts the microwave phase to 0.45π.

[0053] Under the same environmental conditions, compared with traditional atomic gas cell devices, the fiber-optic integrated Rydberg atom microwave detection device provided in this embodiment exhibits the following detection errors for weak microwave signals of 0.01 μV / cm: frequency ≤ 0.01%, intensity ≤ 2.5%, phase ≤ 0.02π, with a signal-to-noise ratio maintained above 45 dB. In contrast, the traditional atomic gas cell device has a signal-to-noise ratio of only 32 dB for microwave signals of the same intensity, with a significantly larger detection error. Experimental results show that the fiber-optic integrated Rydberg atom microwave detection device provided in this embodiment, through the synergy of the bubble microcavity whispering gallery enhancement effect and stable packaging process, improves detection sensitivity by 12 times compared to traditional technologies and possesses superior environmental stability.

[0054] By deeply integrating bubble microcavity UV encapsulation technology with Rydberg atom microwave detection technology, and through an integrated design of 3D-printed glass frame positioning and UV adhesive MY133 encapsulation, the problem of easy drift in traditional coupling structures is solved. Simultaneously, leveraging the light field circulation propagation characteristics of the bubble whispering-gallery microcavity, the light-atom interaction time is extended to over 10 μs, with a light field enhancement factor of 50 times, significantly enhancing the excitation efficiency and microwave response sensitivity of Rydberg atom states. Compared to existing technologies, the fiber-optic integrated Rydberg atom microwave detection device provided in this embodiment combines high sensitivity, high stability, and miniaturization, with a detection bandwidth covering 0.1 GHz-600 GHz. It can be widely applied in high-end scenarios such as weak microwave signal detection, electronic reconnaissance, and stealth target monitoring, possessing strong practical value and promising prospects for widespread application.

[0055] The optical fiber integrated Rydberg atom microwave detection device provided in this embodiment uses a bubble whispering-gallery microcavity filled with alkali metal atom vapor as its core. It employs a tapered optical fiber near-field coupling method to introduce the probe light and coupling light. By leveraging the light field enhancement effect of the whispering-gallery mode, the light-atom interaction time is extended. At the same time, the coupling structure is fixed by ultraviolet adhesive encapsulation, which improves the system stability. By enhancing the excitation efficiency of Rydberg state atoms through the whispering-gallery microcavity, and using the atomic energy level splitting characteristics induced by the microwave field to invert microwave parameters, the device solves the problems of weak light-atom interaction, easy drift of coupling structure, and limited sensitivity of traditional devices. Through the synergistic design of microcavity enhancement and stable encapsulation, the detection sensitivity is improved by more than an order of magnitude compared with traditional technologies. It has the advantages of miniaturization, high stability, and wide bandwidth, and can be widely used in high-end scenarios such as weak microwave signal detection and electronic reconnaissance.

[0056] This embodiment provides a microwave detection method for fiber-integrated Rydberg atoms, applied to the microwave detection device for fiber-integrated Rydberg atoms provided in the above embodiment. See [link to previous embodiment]. Figure 3 The flowchart shown is a microwave detection method for fiber-optic integrated Rydberg atoms. This method mainly includes the following steps: Step S302: Start the optical excitation module, emit probe light based on the probe laser and incident it onto the tapered optical fiber, and emit coupling light based on the coupling laser and incident it onto the tapered optical fiber; Before activating the photoexcitation module, the micro-heating plates on the outside of the bubble microcavity heat the temperature inside the bubble microcavity to the set temperature. When the photoexcitation module is activated, the optical polarization controller is simultaneously triggered to adjust the laser polarization state to TE. 01 model.

[0057] The system initialization and coupling structure encapsulation process begins with fixing the tapered optical fiber to a 3D-printed glass frame. The relative positions of the bubble microcavity and the tapered optical fiber are adjusted using a micro-displacement platform until a critical coupling state is achieved. The ends of the microcavity are then fixed to ensure their positions remain constant. Low-refractive-index UV adhesive MY133 is filled into the coupling area to completely cover the coupling region. A cover glass and glass gasket are then placed on top, and the area is irradiated under a UV lamp for 10 minutes to complete curing and form a stable encapsulated structure. The ends of the microcavity are filled with gas through Teflon tubes, injecting cesium atomic vapor and a mixed buffer gas. After sealing, the temperature control system is activated via the main control unit to raise the microcavity temperature to 55°C and stabilize it for 40 minutes to achieve an atomic vapor concentration of 5 × 10¹¹ atoms / cm³. Simultaneously, the photoexcitation module is activated, and the laser polarization state is adjusted to Teflon. 01 The signal is bundled and transmitted to a tapered optical fiber. The spectrum is monitored by the signal demodulation module until a stable whispering gallery mode (EIT) spectrum is formed, confirming that the system initialization is complete.

[0058] Step S304: Based on the tapered optical fiber, the combined beam formed by the probe light emitted by the probe laser and the coupling light emitted by the coupling laser is near-field coupled into the bubble microcavity, so that the combined beam light field circulates in the whispering gallery mode and fully interacts with the alkali metal atomic vapor to excite and form a stable EIT spectrum. In this process, the probe light excites the alkali metal atom from the ground state to the first excited state, and the coupling light excites the alkali metal atom from the first excited state to the Rydberg state. Rydberg atom excitation, tapered fiber guides the combined beam into the bubble microcavity via near-field coupling, and the optical field is TE 01 The whispering-gallery mode circulates within the microcavity, enhancing the light field by 50 times and allowing for full interaction with atomic vapor. The probe light first excites the atoms from their ground state to the first excited state, and the coupling light further excites them to the Rydberg state, forming a stable EIT spectrum. The main control module monitors the intensity of the spectral transmission peak in real time. When the fluctuation is ≤±0.3%, it indicates that the light-atom interaction state is stable, and the microwave detection stage begins.

[0059] The probe laser and coupling laser can be narrow-linewidth semiconductor lasers with a linewidth of 0.8 kHz, which output 852 nm probe light (transition from the ground state 6S1 / 2 of cesium atoms to the first excited state 6P3 / 2) and 509 nm coupling light (transition from the first excited state 6P3 / 2 to the Rydberg state nD5 / 2), respectively, with output power adjusted to 4 mW and 2.5 mW, respectively.

[0060] The tapered optical fiber described above can be prepared by laser melting and stretching process. The tapered region is 4 mm long and the end diameter is 3 μm. The tapered optical fiber is fixed on a 3D printed glass frame. The glass frame can be pre-positioned with positioning grooves by photolithography process, with a positioning accuracy of ±0.05 μm. After encapsulation, the coupling structure is fixed: the relative position of the bubble microcavity and the tapered optical fiber is adjusted by a micro-displacement platform until the bubble microcavity and the tapered optical fiber reach a critical coupling state; quartz clamps are used to fix both ends of the bubble microcavity to ensure the relative position of the bubble microcavity and the tapered optical fiber is stable; low refractive index UV adhesive MY133 (refractive index 1.33) is filled into the coupling structure area of ​​the bubble microcavity and the tapered optical fiber to completely cover the coupling area, and a cover glass and a glass gasket are placed on top to form a protective cavity. After being irradiated under a UV lamp for a period of time, it is cured. After curing, the drift of the coupling position is ≤ ±0.1μm after 24 hours; Teflon tubes are connected to both ends of the bubble microcavity, and cesium atomic vapor and mixed buffer gas (neon:helium = 4:1, pressure 0.1MPa) are injected through the tubes. After injection, the Teflon tubes are sealed to maintain a stable atomic vapor concentration in the cavity.

[0061] Step S306: Based on the microwave coupling module, the microwave to be measured is focused into the bubble microcavity, and the energy level splitting is induced by the resonance of the Rydberg state atoms in the bubble microcavity to modulate the light field transmittance. Microwave signal coupling occurs when the microwave signal under test is focused by a miniature focusing antenna and acts perpendicularly on the outside of the packaged component. The microwave field penetrates the encapsulation adhesive layer and the microcavity wall, entering the interior and resonating with Rydberg atoms. The extremely large electric dipole moment of the Rydberg atoms causes Autler-Townes splitting of the atomic energy levels. The degree of splitting varies with the microwave frequency and intensity, thereby modulating the transmittance of the whispering-gallery mode optical field. This allows the transmitted light signal to carry microwave parameter information, achieving efficient conversion of microwave signals into optical signals.

[0062] The bubble microcavity can be made of high-purity fused silica material, with an inner diameter of 100μm and a wall thickness of 8μm. A micro ceramic heating plate (power 0-3W) and a high-precision temperature sensor (accuracy ±0.1℃) are attached to the outside. Through closed-loop control of the main control module, the temperature of the bubble microcavity is stabilized at 55℃, so that the cesium atom vapor concentration reaches 5×10¹¹atoms / cm³.

[0063] In the microwave coupling module, the miniature focusing antenna is a parabolic copper foil antenna, fabricated on a quartz substrate using copper foil electroplating. It is attached to the outside of the packaged component, with the focal point coinciding with the center of the microcavity. This allows the spatial microwave signal to be focused into a localized strong electric field, increasing its intensity by 3.2 times. The impedance matching unit incorporates a 50Ω thin-film resistor, integrated into the antenna feed end, reducing microwave reflection loss and enabling the device to cover a detection bandwidth of 0.1GHz-600GHz. The microcavity fixing bracket is made of quartz material and uses photolithographic positioning grooves to simultaneously fix the packaged microcavity component and the miniature focusing antenna, ensuring that the spatial overlap between the microwave field and the optical field inside the microcavity is ≥92%.

[0064] Step S308: Based on the beam splitting module, the transmitted light from the tapered optical fiber is transmitted to the signal conditioning module; Step S310: Based on the signal conditioning module, the transmitted light emanating from the tapered optical fiber is converted from an optical signal into an electrical signal, and the spectral characteristics of the microwave under test are extracted from the electrical signal. Transmitted light within the bubble microcavity is guided out via a tapered optical fiber. After reflection interference is suppressed by an optical fiber isolator, it is input to a photodetector and converted into an electrical signal. The electrical signal undergoes noise reduction processing by a lock-in amplifier to remove environmental and circuit noise, and is then transmitted to a spectrum analyzer and a power meter, respectively. The spectrum analyzer acquires the EIT spectrum after splitting, identifies the splitting frequency (consistent with the microwave frequency) and the splitting amplitude (positively correlated with the microwave intensity), and the power meter acquires real-time power data.

[0065] In the signal demodulation module, an optical fiber isolator is placed at the lead end of the tapered optical fiber, with an isolation of 38dB, effectively suppressing the interference of microcavity reflected light on the stability of the laser output; the avalanche photodetector is a high-gain model with a response wavelength of 700-900nm and a responsivity of 0.95A / W, converting weak transmitted light signals into detectable electrical signals; the lock-in amplifier adopts a low-noise design with a noise floor of 0.7nV / √Hz, which can extract the characteristics of weak signals submerged in noise; the spectrum analyzer has a frequency range of 0-2GHz and a power meter accuracy of ±0.01dBm, respectively collecting spectral splitting characteristics and power data, providing raw data for microwave parameter inversion.

[0066] Step S312: Determine the microwave parameters of the microwave to be measured based on spectral characteristics; wherein, the microwave parameters include microwave frequency, microwave intensity and microwave phase.

[0067] The main control module adopts a dual-core architecture of FPGA XC7K325T and ARM STM32H743, and has built-in optical-atomic interaction optimization algorithm and microwave parameter inversion model. The inversion time is ≤1ms, which meets the requirements of real-time detection.

[0068] The main control module retrieves microwave parameters based on the Autler-Townes splitting law. It calls a pre-calibrated model, determines the microwave frequency through the splitting frequency, calculates the microwave intensity based on the correlation between splitting amplitude and power data, and retrieves the microwave phase using spectral phase shift, thus completing precise parameter measurements. The main control module continuously monitors the EIT spectral stability and signal-to-noise ratio. When environmental disturbances cause spectral fluctuations exceeding ±0.3%, it dynamically adjusts the polarization state of the tapered fiber and the temperature of the bubble microcavity (adjustment accuracy ±0.1℃) to compensate for the attenuation of photo-atomic interaction efficiency. Simultaneously, it corrects impedance matching parameters to ensure stable microwave coupling efficiency and maintain optimal detection accuracy.

[0069] The method provided in this embodiment has the same implementation principle and technical effect as the aforementioned embodiments. For the sake of brevity, any parts not mentioned in the method embodiment can be referred to the corresponding content in the aforementioned device embodiment.

[0070] This invention provides an electronic device, which includes a processor and a memory. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps of the method provided in the above embodiments.

[0071] This invention provides a computer-readable medium storing computer-executable instructions. When these computer-executable instructions are invoked and executed by a processor, they cause the processor to implement the methods described in the above embodiments.

[0072] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0073] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0074] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0075] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0076] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A microwave detection device integrating Rydberg atoms in optical fiber, characterized in that, include: The system includes a light excitation module, a bubble whispering-gallery microcavity, a microwave coupling module, a beam splitting module, a signal conditioning module, and a main control module. The optical excitation module includes a probe laser and a coupling laser; the bubble whispering wall microcavity includes a near-field coupling structure composed of a bubble microcavity and a tapered optical fiber, wherein the bubble microcavity is a sealed gas chamber and is filled with alkali metal atomic vapor; The two ends of the tapered optical fiber are connected to the probe laser and the coupling laser, respectively, and the beam splitting module is connected between the coupling laser and the tapered optical fiber; The tapered optical fiber is used to couple the combined beam formed by the probe light emitted by the probe laser and the coupling light emitted by the coupling laser into the bubble microcavity in the near field, so that the combined beam light field propagates cyclically in a whispering-gallery mode and fully interacts with the alkali metal atom vapor to excite and form a stable EIT spectrum; wherein, the probe light excites the alkali metal atoms from the ground state to the first excited state, and the coupling light excites the alkali metal atoms from the first excited state to the Rydberg state; The microwave coupling module is used to focus the microwave to be measured into the bubble microcavity, and induce energy level splitting by resonance with the atoms of the Rydberg state in the bubble microcavity, so as to modulate the light field transmittance. The beam splitting module is used to transmit the transmitted light emanating from the tapered optical fiber to the signal conditioning module; The signal conditioning module is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal, and to extract the spectral characteristics of the microwave under test from the electrical signal. The main control module is used to determine the microwave parameters of the microwave under test based on the spectral characteristics; wherein the microwave parameters include microwave frequency, microwave intensity and microwave phase.

2. The microwave detection device according to claim 1, characterized in that, The signal conditioning module includes a photodetector, a lock-in amplifier, a spectrum analyzer, and a power meter; The photodetector is used to convert the transmitted light emanating from the tapered optical fiber into an electrical signal; The lock-in amplifier is used for noise reduction processing of the electrical signal; The spectrum analyzer is used to acquire and identify the split frequency and split amplitude of the split EIT spectrum based on the noise-reduced electrical signal; The power meter is used to acquire power data of the split EIT spectrum based on the noise-reduced electrical signal.

3. The microwave detection device according to claim 2, characterized in that, The main control module is also used to determine the microwave frequency, microwave intensity, and microwave phase of the microwave under test based on the splitting frequency, the splitting amplitude, the power data, and the microwave parameter inversion model.

4. The microwave detection device according to claim 1, characterized in that, The microwave coupling module includes a miniature focusing antenna, an impedance matching unit, and a microcavity fixing bracket. The miniature focusing antenna is disposed on the outer wall of the bubble whispering wall microcavity, and the focal point of the miniature focusing antenna coincides with the center point of the bubble microcavity; The impedance matching unit is integrated into the feed terminal of the miniature focusing antenna; The microcavity mounting bracket is used to fix the micro-focusing antenna to the outer wall of the bubble echo wall microcavity.

5. The microwave detection device according to claim 1, characterized in that, The bubble microcavity is a sealed gas chamber prepared based on fused silica material. The bubble microcavity is located directly above the tapered optical fiber, and the coupling distance between the bubble microcavity and the tapered optical fiber ranges from 0.5 to 2 μm.

6. The microwave detection device according to claim 1, characterized in that, The bubble echo wall microcavity also includes a coupling structure support, a sealing structure, a micro heating element, a temperature sensor, and a packaging component; The sealing structure is fixed at both ends of the bubble microcavity, and the micro heating element and the temperature sensor are disposed on the outside of the bubble microcavity; The coupling structure support is used to fix the coupling structure composed of the bubble microcavity and the tapered optical fiber, so that the relative position of the bubble microcavity and the tapered optical fiber remains unchanged. The encapsulation component is used to seal the coupling structure support within the bubble echo wall microcavity so that the relative position of the coupling structure and the coupling structure support remains unchanged.

7. The microwave detection device according to claim 6, characterized in that, Also includes: Fiber optic coupler, polarization-maintaining fiber, and optical polarization controller; the fiber optic coupler is disposed at both ends of the tapered fiber; The two ends of the tapered optical fiber are respectively connected to the probe laser and the coupling laser via the polarization-maintaining optical fiber; The optical polarization controller is used to adjust the probe light and coupling light entering the tapered optical fiber to a polarization state to match the polarization requirements of the bubble microcavity whispering gallery mode.

8. The microwave detection device according to claim 7, characterized in that, The beam splitting module includes a dichroic mirror or a wavelength division multiplexer; And / or, The main control module is also used to control the micro heating plate on the outside of the bubble microcavity to heat the temperature inside the bubble microcavity to a set temperature before starting the photoexcitation module, and simultaneously trigger the optical polarization controller to adjust the laser polarization state to TE when starting the photoexcitation module. 01 model.

9. A microwave detection method for fiber-optic integrated Rydberg atoms, characterized in that, A microwave detection device for fiber-optic integrated Rydberg atoms as described in any one of claims 1-8, wherein the microwave detection method for fiber-optic integrated Rydberg atoms comprises: The optical excitation module is activated, and probe light is emitted from the probe laser and incident on the tapered optical fiber, and coupling light is emitted from the coupling laser and incident on the tapered optical fiber; The probe light emitted by the probe laser and the coupling light emitted by the coupling laser are coupled in the near field into the bubble microcavity based on the tapered optical fiber, so that the combined light field propagates cyclically in a whispering-gallery mode and fully interacts with the alkali metal atom vapor to excite and form a stable EIT spectrum; wherein, the probe light excites the alkali metal atoms from the ground state to the first excited state, and the coupling light excites the alkali metal atoms from the first excited state to the Rydberg state; The microwave coupling module focuses the microwave to be measured into the bubble microcavity, and the energy level splitting is triggered by the atomic resonance of the Rydberg state in the bubble microcavity to modulate the light field transmittance. The transmitted light from the tapered optical fiber is transmitted to the signal conditioning module based on the beam splitting module; The signal conditioning module converts the transmitted light from the tapered optical fiber into an electrical signal and extracts the spectral characteristics of the microwave under test from the electrical signal. The microwave parameters of the microwave to be measured are determined based on the spectral characteristics; wherein the microwave parameters include microwave frequency, microwave intensity and microwave phase.

10. The microwave detection method according to claim 9, characterized in that, Also includes: Before activating the photoexcitation module, the micro-heating plate on the outside of the bubble microcavity is controlled to heat the temperature inside the bubble microcavity to a set temperature. When the photoexcitation module is activated, the optical polarization controller is simultaneously triggered to adjust the laser polarization state to TE. 01 model.

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