A highly integrated Rydberg atom electromagnetic measurement sensor

Abstract

The present invention relates to a highly integrated Rydberg atomic electromagnetic measurement sensor, which is mainly composed of three parts: an antenna component, a signal receiving component and an integrated component. The antenna component includes an atomic gas chamber and three surface-emitting lasers; the signal receiving component includes a planar array photodetector; and the integrated component includes a circuit board. The atomic gas chamber is a rectangular glass gas chamber filled with cesium vapor. The three lasers are two 852nm surface-emitting lasers and one 509nm surface-emitting laser. Lasers and photodetectors are placed around the atomic gas chamber, and 852nm surface-emitting lasers and 509nm surface-emitting lasers, 852nm surface-emitting lasers and planar array photodetectors are placed opposite each other. Four devices are embedded in the circuit board. This device utilizes micro-nano processing and quantum control technology to realize the miniaturization and integration of the Rydberg atomic electromagnetic sensitive system, and has a wide range of application scenarios. It can be used as a new type of electromagnetic measurement sensing equipment in the future, and has great application value in electromagnetic measurement sensitivity under various conditions.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic measurement technology, and in particular to a highly integrated electromagnetic measurement sensor based on Rydberg atoms. Based on the electromagnetic induced transparency effect (EIT) and the Aulter-Townes effect, the present invention proposes a highly integrated Rydberg atom electromagnetic measurement sensor through a method of highly integrating a Rydberg atom gas chamber and an on-chip light source. The sensor can not only provide high-sensitivity and high-precision electromagnetic measurement, but also has the advantages of small size and easy integration. The sensor of the present invention realizes the miniaturization and integration of the Rydberg atom system through innovative design and manufacturing processes, so that it can be widely used in various electromagnetic measurement scenarios. Technical Background

[0002] Electromagnetic measurement technology is widely used in many fields such as land exploration, medical imaging, and material analysis. Although traditional electromagnetic measurement methods, such as coil-based induction measurement and capacitance-based measurement, are sufficient in some applications, they are often difficult to meet the requirements in situations where extremely high sensitivity and miniaturization are required. Current electromagnetic measurement sensors have problems such as low integration, low sensitivity under complex backgrounds, and limited antenna size under the Chu limit. These problems have restricted the development of equipment, and a new type of electromagnetic measurement sensor is urgently needed to solve these problems.

[0003] In recent years, the development of quantum technology has brought new opportunities to the field of electromagnetic measurement. In particular, Rydberg atoms are considered to be an ideal electromagnetic field detector because of their highly adjustable energy level structure and extremely sensitive to external electromagnetic fields. Rydberg atoms usually use a three-level excitation scheme, which will produce an electromagnetically induced transparency effect after excitation. The energy level transitions of Rydberg atoms can be affected by slight changes in the external electromagnetic field, causing them to produce the Aulter-Townes splitting phenomenon. By analyzing the laser signal spectrum, ultra-high precision measurement of the electromagnetic field can be achieved.

[0004] However, existing electromagnetic measurement systems based on Rydberg atoms face some challenges. First, these systems often require complex optical and microwave equipment to excite and detect Rydberg atoms, which makes the system bulky and not conducive to integration and portability. Secondly, the original Rydberg atom electromagnetic measurement system has high requirements for optical path alignment, high operational complexity, and relies on professionals to maintain the system; in addition, due to the high sensitivity of Rydberg atoms and the requirements for optical path alignment, the system is very sensitive to environmental factors, such as the movement of the platform and the obstruction of the optical path by the environment, which may affect the startup speed of the equipment and the accuracy of the measurement results. Summary of the invention

[0005] The technical problem solved by the present invention is: an improvement method is proposed for the technical problems of the existing Rydberg atom electromagnetic measurement system. In view of the fact that the existing system relies on complex optical and microwave equipment to excite and detect Rydberg atoms, resulting in a bulky system that is not conducive to integration and portability, the present invention achieves a high degree of integration of the system and significantly reduces the volume by bonding the gas chamber to the laser. Secondly, in view of the high operational complexity of the original Rydberg atom electromagnetic measurement system and its reliance on professionals for system maintenance, the present invention improves the ease of use and popularity of the system through an integrated design. In addition, in view of the problems of the existing system's optical path alignment failure due to environmental bumps and other factors, the difficulty of system maintenance, and reliance on researchers for maintenance, the present invention adopts an integrated system design strategy to significantly improve the long-term stability of the sensor and ensure the continuous accuracy and reliability of the measurement results.

[0006] The technical solution of the present invention is: In view of the shortcomings of the existing Rydberg atom electromagnetic measurement system, the present invention proposes the following technical solutions: 1. Highly integrated sensor design. The present invention adopts advanced micro-nano processing technology, and integrates the air chamber and the laser into a single chip in a close fit, thereby achieving high system integration and significantly reducing the volume of the sensor, making it easier to carry and deploy. At the same time, the space and structural design of the air chamber ensure the excitation and maintenance of the Rydberg atoms, maintaining the measurement accuracy and performance. This design greatly reduces the volume and weight of the system and improves portability. The sensor of the present invention can achieve efficient electromagnetic field detection in a compact space. 2. Simplified operation process. The present invention simplifies the operation process through integrated design, and encapsulates the complex optical system in a user-friendly operation interface, so that non-professionals can also operate it easily. Through integrated design, the optical path propagation distance and the complexity of the structure are reduced, the original solution's debugging requirements for laser alignment are abandoned, the dependence on professional technicians is reduced, the daily maintenance and troubleshooting process is simplified, and the ease of use and popularity of the system are improved. 3. Long-term stability issues. The present invention realizes chip design by combining the laser and the atomic gas chamber through system design, which reduces the spatial propagation distance, enhances the utilization rate of the laser, improves the long-term stability of the sensor, and ensures the continuous accuracy of the measurement results. These innovative solutions jointly promote the development of Rydberg atomic electromagnetic measurement technology, enabling it to provide efficient, stable and reliable measurement results in various application scenarios.

[0007] The principle of the present invention is:

[0008] (1) Electromagnetically induced transparency effect

[0009] The electromagnetically induced transparency effect is a phenomenon derived from interference technology. When a laser field drives the above system to transition between different energy levels, interference will occur between the transition paths, which is called quantum interference. The electromagnetically induced transparency effect refers to the interaction between an external electromagnetic field (pump field) and an absorbing medium, which changes the absorption of the medium to a certain light (detection field), increases the transmittance, or even makes it completely transparent. Electromagnetically induced transparency originates from the interference between transition channels. When the detection light field and the pump light field meet the two-photon resonance condition, the transition probabilities of the two channels are opposite in sign, and the interference is destructive, resulting in a transparent window at the resonance frequency accompanied by a steep dispersion change.

[0010] Here, a simple three-level atomic system is used as an example to illustrate the EIT phenomenon and its physical mechanism. Taking the Lambda type three-level atomic system as an example, under the dipole approximation, the Hamiltonian of the laser-atom interaction is usually expressed in the form of Rabi coupling (Rabi frequency), where is the amplitude of the electric field component and is the electric dipole moment of the coupled transition. In the interaction picture, the Hamiltonian of the time-dependent interaction describes the interaction between the laser and the atom:

[0011]

[0012] Where the Rabi frequencies of the detection field and the control field are Ω p and Ω c ,Δ 1 =ω 31 -ω p and Δ 2 =ω 32 -ω c are the frequency detuning of the detection field and the control field, σ 31 and σ 32 is the density matrix under the detection field and control field system. Under the rotating wave approximation, the Hamiltonian of the three-level atomic system is expressed as:

[0013]

[0014] Where the Rabi frequencies of the detection field and the control field are Ω p and Ω c ,Δ 1 =ω 31 -ω p and Δ 2 =ω 32 -ω c are the frequency detuning of the detection field and the control field, ω 31 and ω 32 is the transition frequency between the corresponding atomic energy levels. The dynamic evolution of the atomic system excited by light can be described by the density matrix master equation:

[0015]

[0016] Where ρ is the density matrix, H int The second and third terms on the right side of the equation describe the spontaneous radiation decay terms of |3> and |2>, respectively, and their decay rates are Γ 31 and Γ 32 For a closed system, the energy of the interaction process is conserved, and the rate of the dephasing process is γ 2 and γ 3 , where γ 2 The total spontaneous radiation decay rate Γ of the atomic |3> state is determined by the time scale of the actual EIT. 3 =Γ 31 +Γ 32 ,|3> The coherent decay rate of the state is γ 31 =Γ 3 +γ 3d ,γ 32 =Γ 3 +γ 3d +γ 2d ,γ 21 =γ 2d .

[0017] The polarization of the atomic medium under the action of the laser field is the main one, because it is the active term of Maxwell's equations and determines the transmission dynamics of electromagnetic waves. The atomic polarization intensity is:

[0018]

[0019] Assume that there are n atoms per unit volume. a / V interacts with the external field, and the time factor of the exponential part of the above formula comes from the transformation to the Schrödinger picture. The scalar form of the polarization intensity can be obtained:

[0020]

[0021] When considering weak detection fields, the perturbation method can be used to obtain the non-diagonal elements of the density matrix, namely the coherent terms:

[0022]

[0023] Then we can get the linear polarizability of the medium under the interaction scenario:

[0024]

[0025] Where, the real part of the linear polarizability is:

[0026]

[0027] The imaginary part is:

[0028]

[0029] When the control field strength Ω c When it is relatively weak, a very narrow transparent window appears in the middle of the original Lorentz absorption peak, namely the EIT window.

[0030] (2) Aulter-Townes effect

[0031] When a microwave field is introduced into the above three-level system, if the frequency of the microwave field is close to the transition frequency between the atomic energy levels, the microwave field will resonantly couple with the cesium atom, coupling the Rydberg state and another excited state to form a four-level atomic system. In the above case, the middle energy level of the atom is split into two symmetrical energy levels, and the interval of the split is the Rabi frequency of the microwave field. In the EIT signal, the middle main peak is split into two transmission peaks. This phenomenon is the Autler-Townes (EIT-AT) splitting effect of electromagnetically induced transparency.

[0032] Compared with the existing solutions, the main advantages of the solution of the present invention are:

[0033] (1) This method is novel in technology and adopts a new quantum system. It has a simple implementation principle, is easy to calculate, can be traced back to standard physical quantities, and does not require calibration.

[0034] (2) High miniaturization and integration: By using micro-nano processing technology, the antenna's chu limit has been broken, and the gas chamber and laser have been integrated into a single chip, which significantly reduces the size 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 measurement accuracy.

[0035] (3) Simplify the operation process. Through integrated design, complex optical systems are packaged on the chip, allowing non-professionals to focus on signal analysis. This reduces the optical path propagation distance and structural complexity, reduces dependence on professional technicians, simplifies daily maintenance and troubleshooting processes, and improves the ease of use and popularity of the system.

[0036] (4) Long-term stability: Through chip design, the spatial propagation distance is reduced, the laser utilization rate is enhanced, and the long-term stability of the sensor is improved, ensuring the continuous accuracy and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of a highly integrated Rydberg atom electromagnetic measurement sensor Specific implementation plan

[0038] First, place a rectangular glass gas chamber 1 injected with cesium atoms on the experimental table and ensure that it is firmly positioned. Next, place three surface-emitting lasers 3, 5, and 6 close to the four sides of the gas chamber. The four components are embedded in the circuit board 4 to access the signal and control circuits. Specifically, the two lasers 3 and 5 emit 509nm and 852nm lasers respectively. The two lasers need to be placed opposite to each other to ensure that they can be emitted into the atomic gas chamber in opposite directions. In this way, the two beams of pump light will meet inside the gas chamber to form the desired pumping effect. At the same time, a third laser 6 needs to be placed on one side of the gas chamber. This laser also emits 852nm laser, but its function is to serve as a detection light.

[0039] Secondly, adjust the output of the laser to ensure the intensity and stability of the pump light and the probe light. The intensity of the pump light needs to be high enough to effectively excite the cesium atoms, and the intensity of the probe light also needs to be appropriate for subsequent signal detection. At this stage, it is also necessary to ensure that the output frequency and phase of the laser are stable to avoid affecting the experimental results due to the instability of the laser. Next, the laser 6 on the side will emit a beam of 852nm probe light. This beam of probe light needs to be perpendicular to the incident direction of the pump light, that is, perpendicular to the side of the gas chamber and pass through the glass gas chamber. This step is crucial because it ensures that the probe light can interact with the pump light, thereby producing electromagnetically induced transparency (EIT) and Aulter-Townes effect in the cesium atoms.

[0040] Finally, the detection light signal is received and converted by the photodetector 2 placed opposite to the detection light. The photodetector 2 needs to be very sensitive to the intensity changes of the detection light so that it can capture the signal changes caused by the EIT and Aulter-Townes effect. By accurately measuring these changes, we can analyze the intensity and characteristics of the electromagnetic field. In this step, the signal of the photodetector also needs to be properly amplified and filtered to improve the signal-to-noise ratio of the signal and reduce the influence of environmental noise.

[0041] The contents not described in detail in this specification belong to the prior art known to the professionals in this field.

Claims

1. A highly integrated Rydberg atomic electromagnetic measurement sensor, characterized in that A new electromagnetic measurement sensor is proposed, which closely fits a surface light source (3, 5, 6) and a Rydberg atomic gas chamber (1), and the four components are embedded in a circuit board (4) to access the signal and control circuits. The loss of the laser in the air during the propagation process in the existing solution is reduced, the utilization efficiency of the laser is improved, and the volume can be reduced by micro-nano processing of the gas chamber, so that it is easy to play a role on different platforms.

2. A highly integrated Rydberg atomic electromagnetic measurement sensor according to claim 1, characterized in that: A structure combining a surface-emitting light source (3, 5, 6) and an atomic gas chamber (1) is proposed. There are three surface-emitting lasers in total, of which a pair of lasers (3, 5) placed opposite to each other are excitation light lasers, and the other laser (6) is a detection light laser. The two surface-emitting lasers (3, 5) placed opposite to each other emit 852nm and 509nm surface-emitting lasers, which pass through the gas chamber to excite cesium atoms. This excitation process adopts a three-level excitation method, in which the 850nm laser is responsible for exciting the cesium atoms from the ground state to the intermediate state; the 509nm laser is responsible for exciting the cesium atoms from the intermediate state to the Rydberg state. Then, the third laser (6) emits a beam of 852nm surface-emitting laser from the perpendicular direction of the other two lasers, passes through the gas chamber, and is captured by a photodetector (2) placed opposite to each other, and the optical signal is converted into an electrical signal, so as to further analyze the preparation process of the antenna and the sensitivity process to the electromagnetic field.

3. A highly integrated Rydberg atomic electromagnetic measurement sensor according to claim 2, characterized in that: The electromagnetically induced transparency effect of Rydberg atoms and the Aulter-Townes effect are utilized. When the surface-emitting lasers (3, 5) of the 852nm and 509nm excitation light lasers placed oppositely pass through the gas chamber, the cesium atoms are excited from the ground state to the Rydberg state in a three-level excitation manner. Then, after the 852nm detection light emitted by the detection light laser (6) passes through the gas chamber and is captured by the photodetector (2), a transparent peak will appear in the image of the transmittance and the laser detuning amount, which is similar to the phenomenon that the laser propagates freely in the gas chamber without any medium, that is, the electromagnetically induced transparency effect. When there is an electromagnetic field in the sensitive area, and the Rydberg state and another highly excited state happen to resonate with the electromagnetic field, the peak generated by the transmittance will be split, and the splitting interval can reflect the intensity of the electromagnetic signal.

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