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Electromagnetic-acoustic Beam Compressor by Double-physical-fields Null Medium

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Electromagnetic-acoustic Beam Compressor by Double-physical-...

Progress in Electromagnetic Research Symposium (PIERS)

作者： Ran Sun Fei Sun Yichao Liu Zeyu Zhang Chao Yang Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

In this study, double-physical-fields null medium, i.e., a subwavelength air channels surrounded by a carefully arranged metal plates, is utilized to design an electromagnetic-acoustic beam compressor capable of simultaneously compressing electromagnetic waves and acoustic waves. Numerical simulation results verify its ability to simultaneously produce the expected compression ratios for both electromagnetic waves and acoustic waves. Moreover, the compression ratio precisely matches the geometric size ratio of the input and output planes of the compressor. This work may have potential applications in electromagnetic-acoustic coupling systems and electromagnetic-acoustic processing/detection.

关键词： Couplings Electric potential Electromagnetic scattering Metals Numerical simulation Acoustic beams Electromagnetics

Tunable uniform field enhancement in a subwavelength air pillar by photonic doping in epsilon-near-zero medium

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arXiv 2024年

作者： Sun, Fei Shan, Jinyuan Liu, Yichao Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China

In this study, a novel electric field compressor is proposed by doping a metal-air-metal pillar in epsilon-near-zero medium within a metallic waveguide, which effectively enhances the background electric fields in a sub-wavelength air pillar with high uniformity. The field enhancement factor can be analytically determined through theoretical derivations from Maxwell's equations, reaching its maximum value by appropriately selecting the size of the air pillar. Furthermore, the proposed compressor can achieve a tunable electric field enhancement effect within the deep sub-wavelength air pillar by adjusting the height of the air pillar through movement of two metal pillars inserted into the waveguide. Both theoretical analysis and numerical simulations are employed to validate the performance of the electric field compressor, which exhibits a wide range of tunable field enhancement effect (i.e., continuously adjustable enhancement factor between 20 and 800) with uniformity below 1.5 within the deep sub-wavelength air pillar (wherein the air volume is smaller than λ0/10 × λ0/10 × λ0/16). Finally, a practical model is proposed for the realization of the electric field compressor in the microwave range, where specially placed metal pillars and wires are incorporated into a rectangular metallic waveguide structure. The field enhancement and tunable effects of this practical model have been verified through simulations. Copyright © 2024, The Authors. All rights reserved.

关键词： Maxwell equations

Broadband planar electromagnetic hyper-lens with uniform magnification in air

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arXiv 2024年

作者： Sun, Ran Sun, Fei Chen, Hanchuan Liu, Yichao Wang, Qi Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China

A planar hyper-lens, capable of creating sub-wavelength imaging for broadband electromagnetic wave, is designed based on electromagnetic null medium. Subsequently, a scheme for the implementation of the proposed hyper-lens is given by using well-designed flexural metal plates, which function as the reduced electromagnetic null medium for TM-polarized microwaves. Both simulated and measured results verify that the hyper-lens designed with flexural metal plates can achieve super-resolution imaging for microwave at operating wavelength (λ0=3cm) with a resolution of 0.25λ0 and a uniform magnification of about 5. Moreover, the designed hyper-lens ensures that both the object and image surfaces are planes, and simultaneously provides a uniform magnification for objects in different positions. Additionally, the proposed hyper-lens offers a broadband superresolution imaging capabilities, achieving good super-resolution imaging effects for microwave frequencies ranging from 8.5 to 11 GHz. The proposed hyper-lens may find applications in high precision imaging, detection, and sensing. Copyright © 2024, The Authors. All rights reserved.

关键词： optical resolving power

Ultra-broadband acoustic absorber based on periodic acoustic rigid-metaporous composite array

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arXiv 2024年

作者： Zhang, Dongguo Sun, Fei Liu, Yichao Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China

To address the increasingly serious issue of noise pollution, we propose an ultra-broadband and wide-angle acoustic absorber based on a periodic acoustic rigid-metaporous composite array. Numerical simulation results verify the broadband good acoustic absorption performance of the proposed absorber, which can achieve an average absorption coefficient of approximately 90.9% within the frequency band from 500 to 4000 Hz with incident angles ranging from -75 to +75 degrees, thus compensating for the shortcomings of traditional acoustic absorbers that are not as effective at low frequencies. This work will provide a new approach for ultra-broadband and wide-angle acoustic wave absorption and noise suppression. Copyright © 2024, The Authors. All rights reserved.

关键词： Acoustic wave absorption

SA-U-Net++: SAR marine floating raft aquaculture identification based on semantic segmentation and ISAR augmentation

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Journal of Applied Remote Sensing 2021年第1期15卷

作者： Wang, Deyi Han, Min Dalian University of Technology Faculty of Electronic Information and Electrical Engineering Ganjingzi District Dalian China Dalian University of Technology Key Lab. of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Ganjingzi District Dalian China

Marine floating raft aquaculture (FRA) monitoring is vital for environment protection and mariculture management. Synthetic aperture radar (SAR) could provide high-quality remote sensing images under all weather conditions compared with the existing optical remote-sensing-based methods. Traditional SAR monitoring methods extract the pixel feature of marine FRA in single patches, which commonly leads to poor generalization. We propose a self-Attention semantic segmentation method based on modified U-Net++ (SA-U-Net++) for FRA segmentation, which could automatically extract semantic feature information, and provide superior performance under complicated scenes. The proposed self-Attention backbone could help to extract more precise features and enhance the overall accuracy. Furthermore, we propose a FRA-ISAR data generation method based on inverse SAR (ISAR) imaging to alleviate the sample shortage problem. We introduce the semantic segmentation method into FRA-SAR segmentation for the first time. The experiments verify the effectiveness and superiority of SAR FRA segmentation based on the proposed SA-U-Net++ model compared with the existed semantic segmentation approaches. © 2021 Society of Photo-optical Instrumentation Engineers (SPIE).

关键词： Deep learning

Operation Record and Analysis of Interlocking Manual Test based on Input-Output Model 5

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Operation Record and Analysis of Interlocking Manual Test ba...

5th International Conference on Traffic Engineering and Transportation System, ICTETS 2021

作者： Wang, Han Kuang, Wenzhen School of Automation and Electrical Engineering Lanzhou Jiaotong University Lanzhou730070 China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou730070 China

ISBN: (纸本)9781510649910

In order to solve the problems of incomplete interlocking test and incomplete test process, and to make up for the management loophole of completely relying on the laboratory personnel to control the interlocking test quality, the computer interlocking input-output abstract model is established, and the status information of the on-site equipment in the model is input into the variables according to the items to be tested in the interlocking relationship checklist of the station. The test case is constructed by the operation command input variables of the tester and the information display variables of the interlocking interface, and the one-to-one real-time feature matching is carried out by obtaining the relevant data such as the category, time and sequence of the manually clicked buttons, combined with the state change of the signal equipment and the display of the interlocking interface. After matching with the model test case table, the simulation manual automatically marks the matching items in the checklist, so as to achieve the effective supervision of the whole manual test process and improve the reliability of the interlocking test process. © 2021 SPIE

关键词： Quality control

Nanochannel Fabricated on a Silicon-Silver Dimer Gap for Significantly Enhanced Fluorescence

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SSRN

SSRN 2023年

作者： Qiang, Wang Chen, Zhihui Gu, Zhiyuan Li, Lingqiao Guo, Deyi Shi, Baopeng Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Physics Taiyuan University of Technology Taiyuan030024 China

The metal-dielectric dimer is a kind of ideal structure for significantly enhancing single-molecule fluorescence. This enhancement arises from the interaction of single molecules with the metal-dielectric dimer, leading to localized surface plasmon resonance (LSPR), which amplifies the light field by several orders of magnitude. One-dimensional photonic crystals (1D PCs) possess a distinctive photonic bandgap property and can provide nearly perfect reflection for specific wavelengths. These attributes contribute significantly to the enhancement of fluorescence. In light of these considerations, we propose the utilization of 1D PCs as the substrate and a silicon-silver dimer as the quantum dots emitter to achieve remarkable emission enhancement. Our design involves a 20 nm gapped silicon-silver dimer with a 50 nm nanochannel positioned above it. Through the optimization of structural parameters, our results demonstrate that this configuration can achieve approximately five orders of magnitude higher fluorescence enhancement than the bare structure, with a total fluorescence average enhancement of up to 3965 times. These findings stand for the unique sensitivity of the device, making it a promising choice for applications in biological nanoparticle detection, environmental monitoring, and other fields in the future. © 2023, The Authors. All rights reserved.

关键词： Silicon

Experimental demonstration of a thermal-EM concentrator for enhancing EM signals and converging heat fluxes simultaneously

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arXiv 2024年

作者： Chen,, Hanchuan Liu,, Yichao Sun,, Fei Sun, Qianhan Wu,, Xiaoxiao Sun, Ran Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China Guangzhou510000 China

Simultaneously concentrating EM waves and heat fluxes to the same target region within an on-chip system carries substantial academic research importance and practical application value. Nevertheless, existing researches are primarily aimed at the design and experimentation of concentrators for individual EM waves or temperature fields. In this work, a thermal-EM concentrator, capable of simultaneously concentrating EM waves and heat fluxes, is designed using transformation optics/thermodynamics and fabricated with engineered EM-thermal metamaterials. The concentrating effects of the proposed thermal-EM concentrator on the thermal fluxes and EM waves are verified through numerical simulations and experimental measurements, respectively, which are in good agreement with each other. Both numerically simulated and experimentally measured results demonstrate the concentrating capability of the proposed thermal-EM concentrator, which can concentrate broadband TM-polarized EM waves ranging from 8-12 GHz and heat/cold flows to the same target region within an on-chip operating environment. The thermal-EM concentrator exhibits a thermal focusing efficiency close to 100% and more than three times enhancement of the magnetic field at the designed center frequency of 10 GHz. The proposed thermal-EM concentrator can be utilized for efficient cooling for the specified component and simultaneously enhancing the EM antenna's radiation/reception efficiency within an on-chip system. Copyright © 2024, The Authors. All rights reserved.

关键词： Heat flux

Tunable uniform field enhancement in a subwavelength air pillar by photonic doping in epsilon-near-zero medium

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Results in Physics 2024年 61卷

作者： Sun, Fei Shan, Jinyuan Liu, Yichao Zhao, Xiaodan Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan 030024 China

In this study, a novel electric field compressor is proposed by doping a metal-air-metal pillar in epsilon-near-zero medium within a metallic waveguide, which effectively enhances the background electric fields in a sub-wavelength air pillar with high uniformity. The field enhancement factor can be analytically determined through theoretical derivations from Maxwell's equations, reaching its maximum value by appropriately selecting the size of the air pillar. Furthermore, the proposed compressor can achieve a tunable electric field enhancement effect within the deep sub-wavelength air pillar by adjusting the height of the air pillar through movement of two metal pillars inserted into the waveguide. Both theoretical analysis and numerical simulations are employed to validate the performance of the electric field compressor, which exhibits a wide range of tunable field enhancement effect (i.e., continuously adjustable enhancement factor between 20 and 800) with uniformity below 1.5 within the deep sub-wavelength air pillar (wherein the air volume is smaller than λ₀/10 × λ₀/10 × λ₀/16). Finally, a practical model is proposed for the realization of the electric field compressor in the microwave range, where specially placed metal pillars and wires are incorporated into a rectangular metallic waveguide structure. The field enhancement and tunable effects of this practical model have been verified through simulations. © 2024

关键词： Epsilon-near-zero medium Photonic doping Subwavelength field confinement Tunable enhancement