A wideband microwave fast detection method based on atomic energy level electric field tuning

Abstract

This invention relates to the field of microwave detection technology, specifically to a broadband microwave rapid detection method based on atomic level electric field tuning, which mainly solves the problem of detection limitations in traditional Rydberg atom-based microwave information detection. The broadband microwave rapid detection method based on atomic level electric field tuning includes the following steps: 1) First, a probe light and a coupling light are applied sequentially to a Rydberg atom gas cell, and then the microwave to be measured is applied to the Rydberg atom gas cell; 2) A spatial gradient radio frequency electric field is applied within the Rydberg atom gas cell; 3) The spot of the probe light is projected into an optical camera to form an image set, the pixel signals within the image set are merged, and the splitting response of the EIT-AT spectrum is observed. The electric field strength and frequency of the microwave to be measured are calculated. This invention's detection method achieves the requirement for rapid detection of random microwave signals over a wide frequency range.

Description

Technical Field

[0001] This invention relates to the field of microwave detection technology, specifically a broadband microwave rapid detection method based on atomic level electric field tuning. Background Technology

[0002] With the rapid development of modern wireless communication, radar detection, electronic countermeasures, and quantum information technology, the detection of microwave frequencies and microwave electric field strengths is facing the need for rapid identification of random microwave signals. Traditional microwave information detection based on Rydberg atoms is a single-point detection method. Its working principle relies on a pre-known microwave frequency, meaning it can only detect the microwave electric field strength at a known microwave frequency. This has significant limitations and cannot meet the requirement of rapid identification of random microwave signals. Summary of the Invention

[0003] In order to address the limitations of traditional microwave information detection based on Rydberg atoms, this invention provides a novel broadband microwave rapid detection method based on atomic energy level electric field tuning.

[0004] This invention is achieved using the following technical solution: A broadband microwave rapid detection method based on atomic level electric field tuning includes the following steps: 1) First, the probe light and the coupling light are applied to the Rydberg atom gas cell in sequence, causing the Rydberg atom to transition from the ground level to the third energy level. Then, the microwave to be measured is applied to the Rydberg atom gas cell, causing the Rydberg atom to transition from the third energy level to the fourth energy level. 2) Apply a spatial gradient radio frequency electric field to the Rydberg atom chamber to continuously tune the transition frequency of the fourth energy level of the Rydberg atom. 3) The probe light spot is directed into the optical camera to form an image set. The pixel signals in the image set are merged and the splitting response of the EIT-AT spectrum is observed. When a distinctly bimodal symmetrical EIT-AT spectrum appears, the spatial position and splitting interval frequency of the spectrum are recorded. To obtain the electric field strength of the microwave to be measured. : ; in, To reduce Planck's constant, For the transition matrix elements of a Rydberg atom from the third energy level to the fourth energy level, The splitting interval frequency of the EIT-AT spectrum; Based on the radio frequency electric field intensity corresponding to the spatial location of the spectrum The frequency of the microwave to be measured is obtained, which is the microwave resonance frequency of the Rydberg atom transitioning from the third energy level to the fourth energy level. Its expression is: ; in, Rydberg constant, At the speed of light, The principal quantum number of the third energy level. The principal quantum number of the fourth energy level. For the quantum defect of the third energy level, For the quantum defect of the fourth energy level, This represents the polarizability of the Rydberg level corresponding to the fourth energy level.

[0005] Furthermore, the wavelength of the probe light is 852 nm, and the wavelength of the coupling light is 510 nm.

[0006] Furthermore, the Rydberg atom uses cesium atoms, and the third energy level of the cesium atom is selected as 55 s. 1 / 2 The fourth energy level of the cesium atom is chosen to be 55P. 3 / 2 .

[0007] The beneficial effects of this invention are as follows: The broadband microwave rapid detection method based on atomic energy level electric field tuning described in this invention modulates the frequency shift of Rydberg atomic energy levels at different spatial locations by applying a spatial gradient radio frequency electric field, and simultaneously records the changes in signal response characteristics at different locations using an optical camera. This ultimately achieves the requirement for rapid detection of random microwave signals over a wide frequency range, avoiding the technical limitations of traditional microwave information detection based on Rydberg atoms. At the same time, the microwave frequency response range can be tuned by controlling the gradient range of the radio frequency electric field. Attached Figure Description

[0008] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the energy level structure of a Rydberg atom transitioning from the third energy level to the fourth energy level without the addition of a spatial gradient radio frequency electric field. Figure 2 A schematic diagram of the energy level structure of a Rydberg atom transitioning from the third to the fourth energy level after the addition of a spatial gradient radio frequency electric field; Figure 3A schematic diagram of the splitting response of the EIT-AT spectrum after the probe light spot is hit into the optical camera for imaging; In the image: 1 - light spot. Detailed Implementation

[0011] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0012] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0013] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0014] A broadband microwave rapid detection method based on atomic level electric field tuning includes the following steps: 1) First, its 852nm probe light and its 510nm coupling light are applied sequentially to the Rydberg atomic gas cell (in practice, the atoms in the Rydberg atomic gas cell are cesium atoms), causing the Rydberg atoms to change from the base 6S... 1 / 2 Jump to the third energy level 55S 1 / 2 Then, the microwaves to be tested are applied to the Rydberg atom gas cell, causing the Rydberg atom to rise from the third energy level 55 s. 1 / 2 Jump to the fourth energy level 55P 3 / 2 ,like Figure 1 As shown, the Rydberg atom originates from the third energy level 55s. 1 / 2 Jump to the fourth energy level 55P 3 / 2 The microwave reference resonant frequency is Its expression is ; in, Rydberg constant, At the speed of light, The principal quantum number of the third energy level. The principal quantum number of the fourth energy level. For the quantum defect of the third energy level, This represents the quantum defect of the fourth energy level; 2) Applying a spatial gradient radio frequency electric field within the Rydberg atom chamber causes continuous tuning of the transition frequency of the fourth energy level of the Rydberg atom. That is, as the intensity of the radio frequency electric field gradually increases, the fourth energy level of the Rydberg atom undergoes an AC Stark frequency shift towards a lower energy level (the third energy level also experiences a frequency shift, but this is negligible). Figure 2 As shown, the frequency shift is Its expression is: ； in, This represents the Rydberg polarizability corresponding to the fourth energy level. The negative sign indicates the energy level direction, i.e., the frequency shift from a higher energy level to a lower energy level. The radio frequency electric field intensity corresponding to the AC Stark frequency shift of the fourth energy level of a Rydberg atom; 3) The probe light spot 1 is directed into the optical camera to form an image set. The pixel signals within the image set are merged, and the splitting response of the EIT-AT spectrum is observed. Figure 3 As shown, when a distinctly bimodal symmetrical EIT-AT spectrum appears, the spatial location and splitting interval frequency of the spectrum are recorded. To obtain the electric field strength of the microwave to be measured. : ; in, To reduce Planck's constant, For the transition matrix elements of a Rydberg atom from the third energy level to the fourth energy level, The splitting interval frequency of the EIT-AT spectrum; Based on the radio frequency electric field intensity corresponding to the spatial location of the spectrum The frequency of the microwave to be measured is obtained, which is the microwave resonance frequency of the Rydberg atom transitioning from the third energy level to the fourth energy level. Its expression is: .

[0015] Explanation of the principle: ① Microwave rapid detection principle: By applying a spatial gradient radio frequency electric field (spatial gradient radio frequency electric field, i.e., the radio frequency electric field strength of atoms at different spatial locations is different), based on the AC Stark effect, the resonance frequencies of Rydberg atom transitions at different spatial locations are different. At the same time, by combining the spatial location of the EIT-AT spectrum with obvious double-peak symmetry and the splitting interval frequency of the EIT-AT spectrum with the optical camera, the frequency and electric field strength of the microwave under test can be quickly obtained by calculation. ② Wideband microwave response principle: When the radio frequency electric field strength is at its minimum value When, the absolute value of the resulting energy level frequency shift is Its expression is: ; At this point, the maximum microwave resonance frequency of the Rydberg atom transitioning from the third to the fourth energy level is: Its expression is: ; When the radio frequency electric field strength is at its maximum value When, the absolute value of the resulting energy level frequency shift is Its expression is: ; At this point, the minimum microwave resonance frequency for the Rydberg atom to transition from the third to the fourth energy level is: Its expression is: ; The microwave response bandwidth after adding a spatial gradient radio frequency electric field is: Its expression is: ; As can be seen from the above formula, after adding a spatial gradient radio frequency electric field, broadband detection of microwave signals can be achieved (the broadband detection mentioned in this invention is relative to a fixed bandwidth, which is the fixed microwave response bandwidth corresponding to the addition of a fixed electric field).

[0016] To verify the feasibility of the microwave rapid detection method described above, microwaves with known frequency and electric field strength were applied to an atomic gas cell. The frequency and electric field strength of the microwave to be tested obtained by the microwave rapid detection method described above were consistent with the frequency and electric field strength of the actual microwave, proving that the above detection method is feasible.

[0017] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A broadband microwave rapid detection method based on atomic level electric field tuning, characterized in that, Includes the following steps: 1) First, the probe light and the coupling light are applied to the Rydberg atom gas cell in sequence, causing the Rydberg atom to transition from the ground level to the third energy level. Then, the microwave to be measured is applied to the Rydberg atom gas cell, causing the Rydberg atom to transition from the third energy level to the fourth energy level. 2) Apply a spatial gradient radio frequency electric field to the Rydberg atom chamber to continuously tune the transition frequency of the fourth energy level of the Rydberg atom. 3) The spot (1) of the probe light is directed into the optical camera to form an image set. The pixel signals in the image set are merged and the splitting response of the EIT-AT spectrum is observed. When a clear bimodal symmetrical EIT-AT spectrum appears, the spatial position and splitting interval frequency of the spectrum are recorded. To obtain the electric field strength of the microwave to be measured. : ； in, To reduce Planck's constant, For the transition matrix elements of a Rydberg atom from the third energy level to the fourth energy level, The splitting interval frequency of the EIT-AT spectrum; Based on the radio frequency electric field intensity corresponding to the spatial location of the spectrum The frequency of the microwave to be measured is obtained, which is the microwave resonance frequency of the Rydberg atom transitioning from the third energy level to the fourth energy level. Its expression is: ； in, Rydberg constant, At the speed of light, The principal quantum number of the third energy level. The principal quantum number of the fourth energy level. For the quantum defect of the third energy level, For the quantum defect of the fourth energy level, This represents the polarizability of the Rydberg level corresponding to the fourth energy level.

2. The broadband microwave rapid detection method based on atomic level electric field tuning according to claim 1, characterized in that, The wavelength of the probe light is 852 nm, and the wavelength of the coupling light is 510 nm.

3. The broadband microwave rapid detection method based on atomic level electric field tuning according to claim 2, characterized in that, The Rydberg atom uses cesium atoms, and the third energy level of the cesium atom is selected as 55 s. 1 / 2 The fourth energy level of the cesium atom is chosen to be 55P. 3 / 2 .

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