On-chip integrated Rydberg atom electromagnetic measurement sensor

Abstract

The invention relates to an on-chip integrated Rydberg atom electromagnetic measurement sensor which is mainly composed of a sheet-shaped atom gas chamber, a dual-waveband surface emitting laser light source and a signal receiving assembly. The sheet-shaped atomic gas chamber is a glass gas chamber and contains cesium atom steam, the upper surface and the lower surface of the sheet-shaped atomic gas chamber are flat coated glass planes, and the upper surface of the sheet-shaped atomic gas chamber is coated with a film which allows 852 nm light to penetrate outwards from the inside of the gas chamber and reflects 509 nm light; a layer of one-way transmission film is plated on the lower surface, light is not allowed to be emitted outwards from the outer inner side of the gas chamber, and only laser emitted inwards from the outer side of the gas chamber is allowed to be received; the dual-waveband surface-emitting laser light source is a 852 nm and 509 nm dual-waveband sheet surface-emitting light source; the signal receiving assembly is an area array photoelectric detector, the working center frequency band of the signal receiving assembly is located at 852 nm, and the receiving face faces downwards. According to the device, integration of a Rydberg atom electromagnetic measurement system is realized, effective excitation of atoms is maintained, accurate measurement of electromagnetic field intensity can be realized, and the device can be used as novel electromagnetic measurement sensing equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic measurement, and particularly to an on-chip integrated Rydberg atom electromagnetic measurement sensor. Based on the Electromagnetic Induced Transparency (EIT) of Rydberg atoms and the Autler-Townes effect sensitive to electromagnetic fields, through an integrated on-chip design of an atomic gas cell, an excitation light source, and a photodetector, an on-chip integrated Rydberg atom electromagnetic measurement sensor is proposed. This sensor can provide high-sensitivity and high-precision measurement of the intensity of electromagnetic fields, and has the advantages of high integration and small size, and can be used to be carried on various platforms. Through a design based on on-chip applications, the present invention realizes the miniaturization and integration of the Rydberg atom system, enabling it to be widely used in various electromagnetic measurement scenarios. Technical Background

[0002] Traditional electromagnetic detection technologies, such as coil-based inductive measurement and capacitance-based measurement methods, face many challenges when pursuing higher sensitivity and more compact sizes to adapt to complex electromagnetic environments, including insufficient integration, insufficient sensitivity in weak electromagnetic signals, and the contradiction between antenna size and detection performance caused by the Chu limit. These challenges limit the progress of electromagnetic detection devices. Therefore, there is an urgent need to develop a new type of electromagnetic detection sensor to address these problems.

[0003] With the continuous progress of laser control technology and quantum detection technology, a new type of detection mechanism - the quantum mechanism - has emerged in the field of electromagnetic detection. In particular, Rydberg atoms, due to their complex energy level structure, extremely high sensitivity to electromagnetic fields, and noise reduction characteristics that can be traced back to standard physical quantities, have a theoretical sensitivity of -220 dBm / Hz, exceeding the sensitivity limit of classical receivers of -174 dBm / Hz, and are widely regarded as an ideal new electromagnetic detection mechanism. Rydberg atoms usually use a laser light field to excite alkali metal atoms and adopt a two-photon excitation scheme, that is, a three-level excitation scheme, to excite the atoms from the ground state to a Rydberg state with a large principal quantum number. This Rydberg state is extremely sensitive to changes in external electromagnetic fields due to its large distance from the atomic nucleus. When the electromagnetic field resonates with the Rydberg state, in the laser spectral signal, the EIT characteristic peak generated by two-photon excitation will split into two peaks, namely the so-called Autler-Townes effect. By measuring this splitting phenomenon, information such as the intensity of the electromagnetic field can be inferred.

[0004] Although Rydberg atoms show great potential in electromagnetic detection systems, there are still some technical challenges at present. First, exciting Rydberg atoms requires complex optical paths and relatively large lasers, which increases the volume of the entire system and is not conducive to the integration and portability of the system. Second, the Rydberg atom system has extremely high requirements for the accuracy of the optical path and is easily affected by environmental factors, requiring regular maintenance by professionals; in addition, due to the complex optical path, frequency stabilization, excitation and other operations are required for the startup and electromagnetic-sensitive operations of the device. If the optical path is interfered by the environment, it may affect the deployment of the device and the measurement results. Therefore, there is a need to develop a new type of Rydberg atom electromagnetic detection sensor to solve the above problems. Summary of the Invention

[0005] The technical problems to be solved by the present invention are: First, the existing Rydberg atom system relies on a complex optical path, resulting in a large volume and difficulty in carrying the Rydberg atom system; Second, the existing Rydberg atom system requires a high degree of optical alignment and requires professionals to maintain and calibrate the optical path; Finally, the existing Rydberg atom system is easily interfered by the outside world, such as vibration, etc., and there is a certain distance between the structures in space, and the integration degree is not high.

[0006] The technical solution of the present invention is: aiming at the deficiencies of the existing Rydberg atom electromagnetic measurement system, the present invention proposes the following technical solutions: 1. Integrated optical path design. The present invention adopts a method of closely fitting a sheet-shaped gas chamber with a surface-emitting laser to achieve the integration of the system, significantly reducing the volume of the sensor and making it easier to carry and deploy. 2. By closely fitting the gas chambers, the distance that light travels in the air is greatly shortened, enhancing the utilization rate of the laser, improving the long-term stability of the sensor. The user only needs to ensure the lifespan and normal startup of the components, reducing the dependence on professional technicians. 3. Through the integrated design, the structural strength of the device is improved, the optical path propagation distance and the complexity of the structure are reduced, the spatial propagation distance is reduced, and the long-term stability of the sensor is ensured.

[0007] The principle of the present invention is:

[0008] (1) Electromagnetically induced transparency effect

[0009] The Electromagnetically Induced Transparency (EIT) effect refers to a non - linear quantum coherence effect that occurs when light interacts with matter in an opaque medium. In quantum mechanics, the electronic energy states of an atom are quantized into multiple energy levels. When the frequency of a beam of light matches the energy difference between two atomic energy levels (denoted as |1> and |2>), this beam of light can excite electrons to transition from one energy level to another, resulting in the absorption of light by the material. Therefore, for light of this frequency, the atomic system is opaque. To make this frequency of light transparent, an additional low - energy level (denoted as |3>) can be utilized. A strong coherent light beam is used to cause electrons to make back - and - forth transitions between it and the high - energy level. The continuous input of coherent light can maintain the energy exchange between energy levels, causing the two energy levels to be coupled. At this time, the light that could originally be absorbed is no longer absorbed due to this coupling effect, and the material becomes transparent to light of this frequency. In the EIT phenomenon, the externally applied coherent light field induces destructive interference in the atomic system, and this interference cancels out the absorption of a certain light by the medium. This interference effect is caused by the presence of a strong coupling light, which changes the dispersion characteristics of the medium, thereby weakening or eliminating the absorption of the weak probe light by the medium.

[0010] (2) Autler - Townes effect

[0011] The Autler - Townes effect, also known as the AC Stark effect, refers to the phenomenon of the change in the shape of the absorption / emission spectral line when the electric field frequency is close to or resonant with the transition frequency of an atom or molecule in an oscillating electric field. This effect is manifested as the splitting of the corresponding absorption spectral line when the electromagnetic field resonates or is near - resonant with the atomic or molecular transition. In the Rydberg atom system, the measured A - T splitting distance is proportional to the Rabi frequency of the coupling light, and the intensity of the electromagnetic field can be directly inverted through the splitting distance.

[0012] Compared with the existing solutions, the main advantages of the solution of the present invention are as follows:

[0013] (1) This method is novel in technology. It uses a quantum system to replace the traditional one. The implementation principle is simple, easy to calculate, traceable to standard physical quantities, and does not require calibration.

[0014] (2) It has high miniaturization and integration. Using micro - nano processing technology, it breaks through the chu limit of the antenna, integrates the gas chamber and the laser onto a single chip, significantly reduces the volume of the sensor, and improves portability and deployment flexibility. At the same time, the optimized gas chamber design ensures the excitation and maintenance of Rydberg atoms, maintaining the measurement accuracy.

[0015] (3) Simplify the operation process. Through integrated design, encapsulate the complex optical system on the chip, enabling non-professionals to focus on the signal analysis end. Reduce the optical path propagation distance and structural complexity, lower the dependence on professional technicians, simplify the daily maintenance and troubleshooting processes, and enhance the usability and popularity of the system.

[0016] (4) Long-term stability: Through chip design, reduce the spatial propagation distance, enhance the utilization rate of the laser, improve the long-term stability of the sensor, and ensure the continuous accuracy and reliability of the measurement results. Brief Description of the Drawings

[0017] The figure is a schematic diagram of a highly integrated Rydberg atom electromagnetic measurement sensor. Specific Implementation Modes

[0018] First, place the cesium atomic gas cell 2 on the on-chip laser 3, and place the photodetector 1 on the gas cell. Then, the on-chip laser emits lasers with wavelengths of 852 nm and 509 nm upwards, passing through the glass gas cell. The laser penetrates the unidirectional film and enters the Rydberg atomic gas cell, exciting the cesium atoms to the Rydberg state by means of three-level excitation; the photodetector 1 is located at the uppermost part of the component, facing downwards, responsible for receiving the detection optical signal with a wavelength of 852 nm, and then processing the signal to invert and sense the information of the external electromagnetic field.

[0019] The content not described in detail in this invention book belongs to the prior art well-known to those skilled in the art.

Claims

1. An on-chip integrated Rydberg atom electromagnetic measurement sensor, characterized in that A novel electromagnetic measurement sensor is proposed. A sheet-shaped photodetector (1), a sheet-shaped atomic gas cell (2), and a surface-emitting light source (3) are closely attached to reduce the loss of laser in air during propagation and improve the utilization efficiency of the laser. The propagation of light is changed through a coating process to meet the optical path design required for atomic excitation. The volume of the gas cell is reduced through a sheet-shaped design, making it convenient to play a role on different platforms.

2. The highly integrated Rydberg atom electromagnetic measurement sensor according to claim 1, wherein: A structure combining an atomic gas cell (2) and a surface-emitting light source (3) is proposed. The atomic gas cell (2) is located in the middle part of the component, filled with cesium atomic vapor. The upper and lower surfaces are optical windows, connected to the photodetector and the surface-emitting light source respectively. A film that reflects 509 nm laser and transmits 852 nm laser is coated on the upper surface to achieve the reuse of 509 nm laser and the transmission of the 852 nm detection light. The detection light is received by the photodetector above. A unidirectional film is coated on the lower surface to prevent the laser from being reflected back to the laser from the upper surface, causing damage to the laser. The surface-emitting light source (3) is located at the bottom of the component, emitting 852 nm and 509 nm excitation light upward. The laser penetrates the unidirectional film and enters the sheet-shaped Rydberg atomic gas cell, exciting the cesium atoms to the Rydberg state through a three-level excitation path to achieve the preparation of the antenna. The photodetector (1) is located at the top part of the component, facing downward, responsible for receiving the 852 nm wavelength detection light and transmitting the data stream into the digital signal processing system for subsequent signal processing.

3. The highly integrated Rydberg atom electromagnetic measurement sensor according to claim 2, wherein: The Rydberg atom electromagnetically induced transparency effect and the Autler-Townes effect are utilized to be sensitive to the electromagnetic field. When the laser emitted by the surface-emitting dual-band laser (3) passes through the gas cell, the cesium atoms are excited from the ground state to the Rydberg state in a three-level excitation manner. The photodetector receives the detection light, and a transparent spike will appear in the image of the transmittance in the laser spectrum, which is the electromagnetically induced transparency effect. When there is an electromagnetic field in the sensitive region and the Rydberg state happens to be resonantly coupled with another highly excited state, it will cause the spike in the transmittance to split (i.e., the Autler-Townes effect). The splitting interval can be used to invert the intensity of the electromagnetic signal to achieve the measurement of the electromagnetic field intensity.

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