Pub Date : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370979
T. Momose, K. Konishi, Yu Zhao, H. Morishita, Tetsuya Tsuchida, Yuyuan Huang, Hiroyuki Yasukochi, Kentaro Soeda, M. Deura, Y. Shimoyama, J. Yumoto, M. Kuwata-Gonokami, Y. Shimogaki
Three-dimensional (3D) terahertz devices often have difficulty of fabrication due to smaller feature size and complexity of architecture. We herein propose the new fabrication method by combining two techniques; building 3D polymer architecture using high-resolution 3D printing, followed by coating its surface with metal film using high-step-coverage deposition technique, supercritical fluid deposition (SCFD). Difficulty of metal film formation by SCFD onto the polymer is the largest obstacle, but was overcome by a facile surface modification technique to anneal the polymer in oxygen ambient. We thereby demonstrated the fabrication of THz high-pass filter. Our developed method enables the monolithic integration of necessary components for THz devices, for instance passive components together with waveguides. It obviates assembly of individually fabricated components that leads to potential signal loss caused by misalignment, which is more critical with increasing frequency of THz waves.
{"title":"Supercritical fluid deposition technique enabling metallic coating onto 3D-printed polymer for fabrication of high-aspect-ratio THz devices","authors":"T. Momose, K. Konishi, Yu Zhao, H. Morishita, Tetsuya Tsuchida, Yuyuan Huang, Hiroyuki Yasukochi, Kentaro Soeda, M. Deura, Y. Shimoyama, J. Yumoto, M. Kuwata-Gonokami, Y. Shimogaki","doi":"10.1109/IRMMW-THz46771.2020.9370979","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370979","url":null,"abstract":"Three-dimensional (3D) terahertz devices often have difficulty of fabrication due to smaller feature size and complexity of architecture. We herein propose the new fabrication method by combining two techniques; building 3D polymer architecture using high-resolution 3D printing, followed by coating its surface with metal film using high-step-coverage deposition technique, supercritical fluid deposition (SCFD). Difficulty of metal film formation by SCFD onto the polymer is the largest obstacle, but was overcome by a facile surface modification technique to anneal the polymer in oxygen ambient. We thereby demonstrated the fabrication of THz high-pass filter. Our developed method enables the monolithic integration of necessary components for THz devices, for instance passive components together with waveguides. It obviates assembly of individually fabricated components that leads to potential signal loss caused by misalignment, which is more critical with increasing frequency of THz waves.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"32 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78847490","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370866
Xingxing Xu, Min Hu, Zhuocheng Zhang, Xiaoqiuyan Zhang, Shaojie Chang, Feng Xiao, Sen Gon, R. Zhong, Shenggang Liu
The phenomenon of free electrons crossing the periodic structure surface to stimulate radiation is called Smith-Purcell (SP) effect. Former researchers have discovered that by using the open resonator array, SP radiation can have a specific frequency and angle. What's more, this frequency is consist with its resonance mode. However, grating with too small grooves would have lower radiant efficiency, so we present a new structure that add a larger groove at each period of grating, which can not only maintain its radiant characters, but also enhance its radiation intensity. We also use this structure in the transmission grating, which has some better radiant characters than traditional reflection grating. This discovery will provide a new method for the research of high power coherent THz radiation source.
{"title":"Enhanced coherent THz radiation by dual groove grating Smith-Purcell effect","authors":"Xingxing Xu, Min Hu, Zhuocheng Zhang, Xiaoqiuyan Zhang, Shaojie Chang, Feng Xiao, Sen Gon, R. Zhong, Shenggang Liu","doi":"10.1109/IRMMW-THz46771.2020.9370866","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370866","url":null,"abstract":"The phenomenon of free electrons crossing the periodic structure surface to stimulate radiation is called Smith-Purcell (SP) effect. Former researchers have discovered that by using the open resonator array, SP radiation can have a specific frequency and angle. What's more, this frequency is consist with its resonance mode. However, grating with too small grooves would have lower radiant efficiency, so we present a new structure that add a larger groove at each period of grating, which can not only maintain its radiant characters, but also enhance its radiation intensity. We also use this structure in the transmission grating, which has some better radiant characters than traditional reflection grating. This discovery will provide a new method for the research of high power coherent THz radiation source.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"47 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78908677","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370461
T. Song, Wen Wang, Diwei Liu, Shenggang Liu
The effect of the electron beam misalignment on the operating frequency, the frequency-tunable range and the beam-wave interaction efficiency for a continuously frequency-tunable gyrotron has been investigated. It is found that the influence of the misaligned electron beam is significant, the electron beam misalignments should be taken into account and avoided in the design and fabrication of a continuously frequency-tunable gyrotron.
{"title":"Effect of the Electron Beam Misalignments on a Continuously Frequency-Tunable Gyrotron","authors":"T. Song, Wen Wang, Diwei Liu, Shenggang Liu","doi":"10.1109/IRMMW-THz46771.2020.9370461","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370461","url":null,"abstract":"The effect of the electron beam misalignment on the operating frequency, the frequency-tunable range and the beam-wave interaction efficiency for a continuously frequency-tunable gyrotron has been investigated. It is found that the influence of the misaligned electron beam is significant, the electron beam misalignments should be taken into account and avoided in the design and fabrication of a continuously frequency-tunable gyrotron.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"464 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76352791","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370519
L. Liebermeister, S. Nellen, R. Kohlhaas, S. Lauck, M. Deumer, S. Breuer, B. Globisch
We present the first comparison of optoelectronic frequency- and time-domain terahertz (THz) systems for thickness measurements on sub-mm single- and multilayer samples using identical setups, samples and evaluation procedures in order to obtain comparable results. We find that single layer PET and Kapton foils with a thickness of 23 μm – 350 μm can be measured with similar accuracy with both systems. Hence, frequency-domain THz systems may replace time-domain systems in future industrial layer thickness measurements.
{"title":"Comparison of Optoelectronic Time- and Frequency-Domain Systems for Single- and Multilayer Thickness Measurements","authors":"L. Liebermeister, S. Nellen, R. Kohlhaas, S. Lauck, M. Deumer, S. Breuer, B. Globisch","doi":"10.1109/IRMMW-THz46771.2020.9370519","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370519","url":null,"abstract":"We present the first comparison of optoelectronic frequency- and time-domain terahertz (THz) systems for thickness measurements on sub-mm single- and multilayer samples using identical setups, samples and evaluation procedures in order to obtain comparable results. We find that single layer PET and Kapton foils with a thickness of 23 μm – 350 μm can be measured with similar accuracy with both systems. Hence, frequency-domain THz systems may replace time-domain systems in future industrial layer thickness measurements.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"90 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76356097","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370451
U. Schade, L. Puskar, E. Ritter, J. Beckmann
Etalon effects in THz transmittance spectra, either taken in time- domain or frequency-domain, often hamper or even hinder the interpretation of film properties. In this paper we discuss the transferability and applicability of spectroscopic methods typically employed in the near and mid infrared spectral range to eliminate the fringes in the transmittance spectra in the THz spectral range.
{"title":"Etalon Effects in THz Film Measurements","authors":"U. Schade, L. Puskar, E. Ritter, J. Beckmann","doi":"10.1109/IRMMW-THz46771.2020.9370451","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370451","url":null,"abstract":"Etalon effects in THz transmittance spectra, either taken in time- domain or frequency-domain, often hamper or even hinder the interpretation of film properties. In this paper we discuss the transferability and applicability of spectroscopic methods typically employed in the near and mid infrared spectral range to eliminate the fringes in the transmittance spectra in the THz spectral range.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"7 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86831021","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370954
Arjun Singh, V. Ariyarathna, J. Jornet
A plasmonic array architecture with the ability to generate multiple independent, orthogonal beams at THz frequencies is proposed, analytically modeled and numerically demonstrated. The design leverages novel plasmonic device properties to perform discrete Fourier transform for the spatial domain in the analog regime with reduced complexity, and can be utilized to enable ultra-massive MIMO communications.
{"title":"A Plasmonic Array Architecture for Multi-Beam Spatial Multiplexing at THz Frequencies","authors":"Arjun Singh, V. Ariyarathna, J. Jornet","doi":"10.1109/IRMMW-THz46771.2020.9370954","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370954","url":null,"abstract":"A plasmonic array architecture with the ability to generate multiple independent, orthogonal beams at THz frequencies is proposed, analytically modeled and numerically demonstrated. The design leverages novel plasmonic device properties to perform discrete Fourier transform for the spatial domain in the analog regime with reduced complexity, and can be utilized to enable ultra-massive MIMO communications.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"3 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88273471","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370436
Cameron M. Hough, D. Purschke, Chenxi Huang, L. Titova, O. Kovalchuk, Brad J. Warkentin, F. Hegmann
Intense THz pulses have been shown to induce non-thermal biological effects at multiple scales of structural organization, including differential gene expressions in human skin tissue. Epidermal differentiation is a calcium-regulated process, and an excellent candidate for studying genetics of THz-induced biological effects due to the strong over-representation of THz-affected genes in these processes. Results indicate application of THz for targeted inhibition of mitotic activity in skin, and additionally suggest membrane permeation as a key mechanism of THz-induced biological effects. Preliminary experiments investigating fluorescence detection of membrane permeability and techniques of field enhancement in THz-exposed cell lines will be discussed.
{"title":"Genomic Signature of Membrane Permeation Induced by Intense THz Pulses","authors":"Cameron M. Hough, D. Purschke, Chenxi Huang, L. Titova, O. Kovalchuk, Brad J. Warkentin, F. Hegmann","doi":"10.1109/IRMMW-THz46771.2020.9370436","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370436","url":null,"abstract":"Intense THz pulses have been shown to induce non-thermal biological effects at multiple scales of structural organization, including differential gene expressions in human skin tissue. Epidermal differentiation is a calcium-regulated process, and an excellent candidate for studying genetics of THz-induced biological effects due to the strong over-representation of THz-affected genes in these processes. Results indicate application of THz for targeted inhibition of mitotic activity in skin, and additionally suggest membrane permeation as a key mechanism of THz-induced biological effects. Preliminary experiments investigating fluorescence detection of membrane permeability and techniques of field enhancement in THz-exposed cell lines will be discussed.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"61 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88337582","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370399
J. Ornik, N. Staats, E. Stübling, H. Portsteffen, M. Koch
Samples mimicking delamination of preparation and paint layer on a panel and canvas painting were prepared. They were investigated in reflection geometry using THz-TDI before and after consolidation treatment. Regions of delamination and successful consolidation could be identified. The results present a promising starting point for the planed inspection of a painting which is awaiting restoration.
{"title":"Using THz-TDI for Identification of Paint Layer Delamination and Control of its Consolidation","authors":"J. Ornik, N. Staats, E. Stübling, H. Portsteffen, M. Koch","doi":"10.1109/IRMMW-THz46771.2020.9370399","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370399","url":null,"abstract":"Samples mimicking delamination of preparation and paint layer on a panel and canvas painting were prepared. They were investigated in reflection geometry using THz-TDI before and after consolidation treatment. Regions of delamination and successful consolidation could be identified. The results present a promising starting point for the planed inspection of a painting which is awaiting restoration.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"49 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88341381","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370770
M. Kowalski
Systems for detecting face presentation attacks are facing great challenges since new 3D facial masks are used. Passive terahertz imaging offer specific physical properties that may improve presentation attack detection capabilities. The aim of this paper is to present outcomes of study on using novel 3D facial masks for face presentation attack detection in passive imaging at 250 GHz. A thorough analysis of presentation attacks for facial recognition systems using custom 3D-printed and custom flexible 3D-latex masks is provided together with spectral characterization of various items. A set of experiments with various spoofing items is described and discussed. Finally, a presentation attack detection method with passive imaging at 250 GHz is presented.
{"title":"Face presentation attack detection with passive imaging at 250 GHz","authors":"M. Kowalski","doi":"10.1109/IRMMW-THz46771.2020.9370770","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370770","url":null,"abstract":"Systems for detecting face presentation attacks are facing great challenges since new 3D facial masks are used. Passive terahertz imaging offer specific physical properties that may improve presentation attack detection capabilities. The aim of this paper is to present outcomes of study on using novel 3D facial masks for face presentation attack detection in passive imaging at 250 GHz. A thorough analysis of presentation attacks for facial recognition systems using custom 3D-printed and custom flexible 3D-latex masks is provided together with spectral characterization of various items. A set of experiments with various spoofing items is described and discussed. Finally, a presentation attack detection method with passive imaging at 250 GHz is presented.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"124 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86434270","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 : 2020-11-08DOI: 10.1109/IRMMW-THz46771.2020.9370906
K. Tabata, T. Kariya, Y. Oda, R. Minami, M. Fukunari, R. Ikeda, K. Hayashi, T. Taniguchi, Y. Harada, T. Takeuchi, T. Imai, K. Sakamoto, K. Komurasaki, Y. Tatematsu, Y. Yamaguchi, K. Kajiwara, K. Takahashi
To realize the GW-class power source for Microwave Rocket, the cost reduction of gyrotrons is one of the solutions to lower the threshold to realize the beam station. In this study, a sub-MW-class gyrotron which adapted a smaller bore diameter of the superconducting magnet was designed and developed. The output power, pulse duration, and frequency are respectively 600 kW, $100 mumathrm{s}$, and 94 GHz. The electron current is driven by a charged capacitor bank and in-house IGBT switches. The gyrotron tube was aligned with the superconducting magnet to achieve high electric efficiency.
为了实现千兆瓦级的微波火箭电源，降低回旋管的成本是降低波束站实现门槛的解决方案之一。本研究设计并研制了一种亚毫瓦级的回旋管，该回旋管适应较小口径的超导磁体。输出功率为600kw，脉冲持续时间为$100 mu mathm {s}$，频率为94ghz。电子电流由充电电容器组和内部IGBT开关驱动。回旋管与超导磁体对齐，实现了高电效率。
{"title":"Development of a High Power Gyrotron Prototype for GW-Class Microwave Beam Source Study","authors":"K. Tabata, T. Kariya, Y. Oda, R. Minami, M. Fukunari, R. Ikeda, K. Hayashi, T. Taniguchi, Y. Harada, T. Takeuchi, T. Imai, K. Sakamoto, K. Komurasaki, Y. Tatematsu, Y. Yamaguchi, K. Kajiwara, K. Takahashi","doi":"10.1109/IRMMW-THz46771.2020.9370906","DOIUrl":"https://doi.org/10.1109/IRMMW-THz46771.2020.9370906","url":null,"abstract":"To realize the GW-class power source for Microwave Rocket, the cost reduction of gyrotrons is one of the solutions to lower the threshold to realize the beam station. In this study, a sub-MW-class gyrotron which adapted a smaller bore diameter of the superconducting magnet was designed and developed. The output power, pulse duration, and frequency are respectively 600 kW, $100 mumathrm{s}$, and 94 GHz. The electron current is driven by a charged capacitor bank and in-house IGBT switches. The gyrotron tube was aligned with the superconducting magnet to achieve high electric efficiency.","PeriodicalId":6746,"journal":{"name":"2020 45th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"94 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83916546","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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