Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221499
Ming Jin, Xi Rui Yang, C. Yang, M. Tong
Electromagnetic inverse scattering is a challenging problem in many areas of science and engineering, including radar imaging, medical imaging, and non-destructive testing. The goal of inverse scattering is to recover the properties of an object from the scattered electromagnetic waves that are generated when the object is illuminated with incident waves. The inverse scattering problem is inherently difficult because the properties of the object cannot be measured directly, and only the scattered waves can be observed. In recent years, convolutional neural networks (CNNs) have shown great promise in solving inverse scattering problems. The U-Net model is a popular CNN architecture that has been used to solve a wide range of image processing and recognition tasks. However, the U-Net model has limitations in dealing with complex inverse scattering problems due to the limited information available in the scattered wave data. To address this limitation, we propose an improved U-Net model called M-Net, which incorporates multi-scale features and a mean output layer to improve the accuracy and stability of the reconstruction. The M-Net model consists of a multi-scale input layer, a U-shape convolutional neural network, and a multi-scale mean output layer. Direct prediction methods take scattering field data as network input, which can greatly reduce the manual calculation workload, but this method does not make full use of known physical a priori information, resulting in a waste of computing resources. Therefore, we use diffraction tomography (DT) images based on Born approximation as the network input, which can ensure imaging accuracy and improve computational efficiency. In order to verify the effectiveness of the proposed method, a simulation experiment is carried out with a target medium as the reconstruction target. The results show that the M-Net model combined with the tomographic diffraction algorithm is superior to the U-Net model and other existing direct-solving methods in terms of accuracy and efficiency in solving the electromagnetic inverse scattering problems. The error analysis further proves the superior performance of the M-Net model combined with the tomographic diffraction algorithm in the complex inverse scattering problem.
{"title":"Improved Electromagnetic Inverse Scattering with M-Net Model Incorporating Diffraction Tomography","authors":"Ming Jin, Xi Rui Yang, C. Yang, M. Tong","doi":"10.1109/PIERS59004.2023.10221499","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221499","url":null,"abstract":"Electromagnetic inverse scattering is a challenging problem in many areas of science and engineering, including radar imaging, medical imaging, and non-destructive testing. The goal of inverse scattering is to recover the properties of an object from the scattered electromagnetic waves that are generated when the object is illuminated with incident waves. The inverse scattering problem is inherently difficult because the properties of the object cannot be measured directly, and only the scattered waves can be observed. In recent years, convolutional neural networks (CNNs) have shown great promise in solving inverse scattering problems. The U-Net model is a popular CNN architecture that has been used to solve a wide range of image processing and recognition tasks. However, the U-Net model has limitations in dealing with complex inverse scattering problems due to the limited information available in the scattered wave data. To address this limitation, we propose an improved U-Net model called M-Net, which incorporates multi-scale features and a mean output layer to improve the accuracy and stability of the reconstruction. The M-Net model consists of a multi-scale input layer, a U-shape convolutional neural network, and a multi-scale mean output layer. Direct prediction methods take scattering field data as network input, which can greatly reduce the manual calculation workload, but this method does not make full use of known physical a priori information, resulting in a waste of computing resources. Therefore, we use diffraction tomography (DT) images based on Born approximation as the network input, which can ensure imaging accuracy and improve computational efficiency. In order to verify the effectiveness of the proposed method, a simulation experiment is carried out with a target medium as the reconstruction target. The results show that the M-Net model combined with the tomographic diffraction algorithm is superior to the U-Net model and other existing direct-solving methods in terms of accuracy and efficiency in solving the electromagnetic inverse scattering problems. The error analysis further proves the superior performance of the M-Net model combined with the tomographic diffraction algorithm in the complex inverse scattering problem.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129396702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221513
K. Kulakova, J. Vrba, T. Drizdal
Today, fruitful research in biomedicine and rapid advancement of technology empower humanity to successfully treat numerous diseases. Nevertheless, the question of finding a safe and universal strategy of treating cancer still tops the list of urgent issues in healthcare. The need to always balance on the risk-benefit border while using conventional treatment methods due to their side effects has led to the initiation of research targeted at exploration of more sophisticated and delicate treatment strategies. One of the established and promising methods is microwave hyperthermia. It uses an increase in temperature caused by electromagnetic waves to destroy cancer cells. The main biological effects of hyperthermia include increase in blood perfusion, leading to an increase in the uptake of chemotherapy drugs in the tumor area, as well as oxygenation of tumor cells, which increases the sensitivity of cells to radiotherapy. Other effects are, for example, activation of the immune system, denaturation of proteins, and limitation of the ability of tumor cells to repair their damaged DNA. Practical implementation of this concept was successful, although there is still demand for new and more effective strategies for hyperthermic treatment planning. Therefore, the main objective of this work was the development of the tool that would facilitate this task. To achieve this, a 2-D realistic patient model based on a numerical phantom was successfully implemented in the programming environment MATLAB. The numerical nature of the model allowed to introduce the Finite-Difference-Time-Domain-based algorithm to simulate electromagnetic field from each energy source as well as the specific absorption rate in the model resulting from source activity. The performance of the developed simulator was successfully verified by the commercial simulation software COMSOL Multiphysics. The tool can be used both in research settings for investigating the performance of various treatment planning strategies and as a part of treatment planning and controlling software for real-world microwave hyperthermia systems.
{"title":"The Power of Numerical Simulations in Advancing Treatment Planning during Microwave Hyperthermia","authors":"K. Kulakova, J. Vrba, T. Drizdal","doi":"10.1109/PIERS59004.2023.10221513","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221513","url":null,"abstract":"Today, fruitful research in biomedicine and rapid advancement of technology empower humanity to successfully treat numerous diseases. Nevertheless, the question of finding a safe and universal strategy of treating cancer still tops the list of urgent issues in healthcare. The need to always balance on the risk-benefit border while using conventional treatment methods due to their side effects has led to the initiation of research targeted at exploration of more sophisticated and delicate treatment strategies. One of the established and promising methods is microwave hyperthermia. It uses an increase in temperature caused by electromagnetic waves to destroy cancer cells. The main biological effects of hyperthermia include increase in blood perfusion, leading to an increase in the uptake of chemotherapy drugs in the tumor area, as well as oxygenation of tumor cells, which increases the sensitivity of cells to radiotherapy. Other effects are, for example, activation of the immune system, denaturation of proteins, and limitation of the ability of tumor cells to repair their damaged DNA. Practical implementation of this concept was successful, although there is still demand for new and more effective strategies for hyperthermic treatment planning. Therefore, the main objective of this work was the development of the tool that would facilitate this task. To achieve this, a 2-D realistic patient model based on a numerical phantom was successfully implemented in the programming environment MATLAB. The numerical nature of the model allowed to introduce the Finite-Difference-Time-Domain-based algorithm to simulate electromagnetic field from each energy source as well as the specific absorption rate in the model resulting from source activity. The performance of the developed simulator was successfully verified by the commercial simulation software COMSOL Multiphysics. The tool can be used both in research settings for investigating the performance of various treatment planning strategies and as a part of treatment planning and controlling software for real-world microwave hyperthermia systems.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131032181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221371
M. Ivanyan, B. Grigoryan, L. Aslyan, A. Grigoryan, A. Vardanyan, V. Avagyan
The resonant properties of wake fields in a three-layer cylindrical waveguide are investigated. A metal-dielectric waveguide is considered, the walls of which are covered from the inside with a thin low-conductivity metal layer that prevents charge accumulation on the dielectric surface and, at the same time, absorbs residual gas molecules. The distorting effect of the inner metal coating on the resonant characteristics of the wake fields is estimated. Various combinations of geometric and electromagnetic parameters of the structure are considered in order to optimize it as a beam guide with minimal losses or a source of monochromatic radiation.
{"title":"Wake Fields in a Three-Layer Cylindrical Waveguide","authors":"M. Ivanyan, B. Grigoryan, L. Aslyan, A. Grigoryan, A. Vardanyan, V. Avagyan","doi":"10.1109/PIERS59004.2023.10221371","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221371","url":null,"abstract":"The resonant properties of wake fields in a three-layer cylindrical waveguide are investigated. A metal-dielectric waveguide is considered, the walls of which are covered from the inside with a thin low-conductivity metal layer that prevents charge accumulation on the dielectric surface and, at the same time, absorbs residual gas molecules. The distorting effect of the inner metal coating on the resonant characteristics of the wake fields is estimated. Various combinations of geometric and electromagnetic parameters of the structure are considered in order to optimize it as a beam guide with minimal losses or a source of monochromatic radiation.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130409676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221243
Q. Didier, S. Arhab, G. Lefeuve-Mesgouez
We propose a numerical approach that combines both finite elements with volume and boundary integral methods. The boundary integral formulation replaces the far incident field source with a set of monopole and dipole sources, which are in the vicinity of the object and generate an equivalent illumination. Then the electromagnetic interaction between this incident field and the object under test is modeled by finite elements on a much smaller domain. The volume integral formulation is introduced to calculate semi-analytically the total field at any point outside the finite element discretization domain. Numerical results show that this approach speeds up the computation time, reduces the memory consumption, and does not suffer from a lack of accuracy when the source and observation points get more distant from the object, contrary to a pure finite element resolution. The proposed numerical approach is also successfully tested on the Fresnel Institute's microwave measurements.
{"title":"An Efficient Numerical Approach Combining Finite Element with Integral Methods","authors":"Q. Didier, S. Arhab, G. Lefeuve-Mesgouez","doi":"10.1109/PIERS59004.2023.10221243","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221243","url":null,"abstract":"We propose a numerical approach that combines both finite elements with volume and boundary integral methods. The boundary integral formulation replaces the far incident field source with a set of monopole and dipole sources, which are in the vicinity of the object and generate an equivalent illumination. Then the electromagnetic interaction between this incident field and the object under test is modeled by finite elements on a much smaller domain. The volume integral formulation is introduced to calculate semi-analytically the total field at any point outside the finite element discretization domain. Numerical results show that this approach speeds up the computation time, reduces the memory consumption, and does not suffer from a lack of accuracy when the source and observation points get more distant from the object, contrary to a pure finite element resolution. The proposed numerical approach is also successfully tested on the Fresnel Institute's microwave measurements.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129343938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221376
Yezhou Yang, W. Yu, H. Bao, Dazhi Ding, T. Cui
An efficient discontinuous Galerkin time-domain (DGTD) method with polynomial chaos expansion (PCE) is proposed to analyze unbounded target scattering with interval-valued electromagnetic parameters. The proposed PCE technology is used to represent the interval-valued variables in electromagnetic analysis. The method maintains the advantages of DGTD approach which is a spatially explicit algorithm that can be easily parallelized. Moreover, the electromagnetic properties in the interval can be obtained from just a single simulation. The proposed method is validated by modeling a dielectric missile with an interval-valued permittivity. Numerical results demonstrate the accuracy and robustness of the proposed method.
{"title":"Interval Evaluation of Electromagnetic Scattering Using a Polynomial Chaos Expansion-Based DGTD Method","authors":"Yezhou Yang, W. Yu, H. Bao, Dazhi Ding, T. Cui","doi":"10.1109/PIERS59004.2023.10221376","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221376","url":null,"abstract":"An efficient discontinuous Galerkin time-domain (DGTD) method with polynomial chaos expansion (PCE) is proposed to analyze unbounded target scattering with interval-valued electromagnetic parameters. The proposed PCE technology is used to represent the interval-valued variables in electromagnetic analysis. The method maintains the advantages of DGTD approach which is a spatially explicit algorithm that can be easily parallelized. Moreover, the electromagnetic properties in the interval can be obtained from just a single simulation. The proposed method is validated by modeling a dielectric missile with an interval-valued permittivity. Numerical results demonstrate the accuracy and robustness of the proposed method.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127980058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221277
T. Nagayama
The design method of broadband metasurfaces for generating a two-dimensional (2-D) Gaussian beam from a normal incident plane wave with the same amplitude distribution is presented based on the one-dimensional transmission-line model. The formula of the characteristic impedance of the model is derived according to the concept and an electromagnetic metasurface is designed by using the model with the parameters determined from the formula. Circuit simulations are carried out to confirm the validity of the design with the model. The results show that the designed metasurface generates a 2-D Gaussian beam from an incident plane wave and also has the broadband characteristics.
{"title":"Design Method of Broadband Metasurfaces for Generating a Two-dimensional Gaussian Beam from a Normal Incident Plane Wave with the Same Amplitude Distribution","authors":"T. Nagayama","doi":"10.1109/PIERS59004.2023.10221277","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221277","url":null,"abstract":"The design method of broadband metasurfaces for generating a two-dimensional (2-D) Gaussian beam from a normal incident plane wave with the same amplitude distribution is presented based on the one-dimensional transmission-line model. The formula of the characteristic impedance of the model is derived according to the concept and an electromagnetic metasurface is designed by using the model with the parameters determined from the formula. Circuit simulations are carried out to confirm the validity of the design with the model. The results show that the designed metasurface generates a 2-D Gaussian beam from an incident plane wave and also has the broadband characteristics.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129016055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221245
P. E. Sics, O. Selis, S. Migla, M. Zeltins, S. Spolitis, V. Kurtenoks, A. Aboltins
Energy efficiency is an important metric by which modern communications systems are evaluated. Pulse position modulation (PPM), which uses time intervals among pulses to encode the transmitted data, provides unlimited energy-saving opportunities at the cost of spectrum occupancy. Considering this excellent property, PPM is gaining attention as a candidate waveform for the next generation of long-distance and space communications, where energy efficiency and peak signal-to-noise ratio are the key factors. This paper is devoted to implementing and evaluating a high-speed transmitted reference pulse-position modulation (TR-PPM) modulator board that employs a digital-to-time converter (DTC) based on high-accuracy programmable delay line integrated circuits. The developed prototype can generate high-order TR-PPM signals with up to 256 pulse positions, having a time resolution of 40 ps. Using step recovery diodes (SRDs) at the front-end of the modulator allows for achieving a pulse duration of about 150 ps. The testing of the developed prototype has shown that the board can generate TR-PPM waveform with high accuracy and allows achieving data rates up to 20 Mbit/s.
{"title":"Programmable Delay Line Based High-speed PPM Modulator with 50 ps Time Resolution","authors":"P. E. Sics, O. Selis, S. Migla, M. Zeltins, S. Spolitis, V. Kurtenoks, A. Aboltins","doi":"10.1109/PIERS59004.2023.10221245","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221245","url":null,"abstract":"Energy efficiency is an important metric by which modern communications systems are evaluated. Pulse position modulation (PPM), which uses time intervals among pulses to encode the transmitted data, provides unlimited energy-saving opportunities at the cost of spectrum occupancy. Considering this excellent property, PPM is gaining attention as a candidate waveform for the next generation of long-distance and space communications, where energy efficiency and peak signal-to-noise ratio are the key factors. This paper is devoted to implementing and evaluating a high-speed transmitted reference pulse-position modulation (TR-PPM) modulator board that employs a digital-to-time converter (DTC) based on high-accuracy programmable delay line integrated circuits. The developed prototype can generate high-order TR-PPM signals with up to 256 pulse positions, having a time resolution of 40 ps. Using step recovery diodes (SRDs) at the front-end of the modulator allows for achieving a pulse duration of about 150 ps. The testing of the developed prototype has shown that the board can generate TR-PPM waveform with high accuracy and allows achieving data rates up to 20 Mbit/s.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126454219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221305
T. Auriac, J. Raoult
Near field vector measurement are used from optics to microwaves to identify and image materials and devices on the surface or buried under a thin layer of material. We developed a model of near field interaction between a dipole and a substrate based on our experimental setup of near field millimeter wave vector microscopy. A comparison between the model and the measurement results is presented and discussed.
{"title":"Experiments and Modeling of a Near-Field Millimeter Wave Vector Microscope","authors":"T. Auriac, J. Raoult","doi":"10.1109/PIERS59004.2023.10221305","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221305","url":null,"abstract":"Near field vector measurement are used from optics to microwaves to identify and image materials and devices on the surface or buried under a thin layer of material. We developed a model of near field interaction between a dipole and a substrate based on our experimental setup of near field millimeter wave vector microscopy. A comparison between the model and the measurement results is presented and discussed.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"179 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122788562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.1109/PIERS59004.2023.10221304
Zedi Li, Yijun Xie, Renlong Zhu, Jingyi Wang, Zhengqiong Dong, Xiaoping Zhou, Lei Nie, Shiyuan Liu, Jinlong Zhu
Nowadays, photonic devices are increasingly applied in photonic chips, and photonic nanostructures are an important component of photonic devices. Due to their small size and high precision requirements, it is necessary to measure photonic devices as soon as possible after production. In this paper, we propose a microscopy system based on modified co-optical off-axis digital holographic microscopy (CO-DHM), which uses the Kramers-Kronig (KK) relation to extract phase information from interferograms. This configuration reduces noise and is single-shot, meaning high-speed and high-precision phase imaging can be achieved. We applied this microscopy system to the measurement of photonic nanostructures and perform phase imaging of a strip waveguide and a gold marker on an in-house developed photonic chip.
{"title":"Optical Measurement of Photonic Nanostructures Based on Quantitative Phase Microscopy","authors":"Zedi Li, Yijun Xie, Renlong Zhu, Jingyi Wang, Zhengqiong Dong, Xiaoping Zhou, Lei Nie, Shiyuan Liu, Jinlong Zhu","doi":"10.1109/PIERS59004.2023.10221304","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221304","url":null,"abstract":"Nowadays, photonic devices are increasingly applied in photonic chips, and photonic nanostructures are an important component of photonic devices. Due to their small size and high precision requirements, it is necessary to measure photonic devices as soon as possible after production. In this paper, we propose a microscopy system based on modified co-optical off-axis digital holographic microscopy (CO-DHM), which uses the Kramers-Kronig (KK) relation to extract phase information from interferograms. This configuration reduces noise and is single-shot, meaning high-speed and high-precision phase imaging can be achieved. We applied this microscopy system to the measurement of photonic nanostructures and perform phase imaging of a strip waveguide and a gold marker on an in-house developed photonic chip.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125808339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
THz backward-wave oscillator (BWO) is a high-power, tunable frequency, and high-frequency terahertz radiation source. In this paper, the high-frequency system and electron optics system of a 1.0 THz BWO are studied. And the staggered double vane structure is used to improve the efficiency of the beam wave interaction efficiency. At the operating voltage of 25 kV and the electron beam current of 20 mA, the stable output power of BWO is 554mW, and the oscillation frequency is 1.029 THz. We also designed the electron optics system of a 1.0 THz BWO, in which the cathode excitation current reached 20mA at an operating voltage of 25 kV. Under the influence of a uniform magnetic field of 1.2 T, the transmission was stable, and the pass rate was over 99%.
{"title":"Design and Simulation of 1.0 THz Staggered Double Vane Backward-wave Oscillator","authors":"Wenxin Liu, Xiangpeng Liu, Zhi-qiang Zhang, Zhihao Jin, Fan Deng, Zhaochuan Zhang","doi":"10.1109/PIERS59004.2023.10221517","DOIUrl":"https://doi.org/10.1109/PIERS59004.2023.10221517","url":null,"abstract":"THz backward-wave oscillator (BWO) is a high-power, tunable frequency, and high-frequency terahertz radiation source. In this paper, the high-frequency system and electron optics system of a 1.0 THz BWO are studied. And the staggered double vane structure is used to improve the efficiency of the beam wave interaction efficiency. At the operating voltage of 25 kV and the electron beam current of 20 mA, the stable output power of BWO is 554mW, and the oscillation frequency is 1.029 THz. We also designed the electron optics system of a 1.0 THz BWO, in which the cathode excitation current reached 20mA at an operating voltage of 25 kV. Under the influence of a uniform magnetic field of 1.2 T, the transmission was stable, and the pass rate was over 99%.","PeriodicalId":354610,"journal":{"name":"2023 Photonics & Electromagnetics Research Symposium (PIERS)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125842606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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