Pub Date : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8509983
R. Su, Y. Zhang, X. Tu, X. Jia, L. Kang, B. Jin, W. Xu, J. Chen, P. Wu
Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) with thermal, microwave (MW) and THz biasing have been studied at 0.65 THz and 4.2 K in detail. The current responsivity and noise equivalent power (NEP) have been measured and compared respectively. The detectors with the MW and THz biasing have about one order higher current responsivity than that of the thermal one. With the MW biasing, an NEP at the order of $mathrm{pW}/surdmathrm{Hz}$ is obtained by choosing the MW frequency and power appropriately.
{"title":"Terahertz (THz) Direct Detectors based on Superconducting HEBs with Thermal, Microwave and THz Biasing","authors":"R. Su, Y. Zhang, X. Tu, X. Jia, L. Kang, B. Jin, W. Xu, J. Chen, P. Wu","doi":"10.1109/IRMMW-THZ.2018.8509983","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8509983","url":null,"abstract":"Terahertz (THz) direct detectors based on superconducting niobium nitride (NbN) hot electron bolometers (HEBs) with thermal, microwave (MW) and THz biasing have been studied at 0.65 THz and 4.2 K in detail. The current responsivity and noise equivalent power (NEP) have been measured and compared respectively. The detectors with the MW and THz biasing have about one order higher current responsivity than that of the thermal one. With the MW biasing, an NEP at the order of $mathrm{pW}/surdmathrm{Hz}$ is obtained by choosing the MW frequency and power appropriately.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"8 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89138790","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8509961
Luyang Wang, F. Lan, Hongxin Zeng, Ziqiang Yang, P. Mazumder, Feng Luo, Abdur Rauf Khan, Zongjun Shi
A reflective polarization converter with HEMT -embedded net-grid metasurface is demonstrated here. The polarizer can convert a linearly polarized (LP) wave to its cross-polarized wave at four resonant frequencies with a high polarization conversion ratio, and it can convert the LP wave to a circularly polarized (CP) wave at the other eight resonant frequencies. The novel polarization converter may greatly benefit potential applications in terahertz ultrafast polarization manipulation.
{"title":"Terahertz Quadruple-Band Switching Polarization Converter Based on HEMT - Embedded Net-Grid Metasurface","authors":"Luyang Wang, F. Lan, Hongxin Zeng, Ziqiang Yang, P. Mazumder, Feng Luo, Abdur Rauf Khan, Zongjun Shi","doi":"10.1109/IRMMW-THZ.2018.8509961","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8509961","url":null,"abstract":"A reflective polarization converter with HEMT -embedded net-grid metasurface is demonstrated here. The polarizer can convert a linearly polarized (LP) wave to its cross-polarized wave at four resonant frequencies with a high polarization conversion ratio, and it can convert the LP wave to a circularly polarized (CP) wave at the other eight resonant frequencies. The novel polarization converter may greatly benefit potential applications in terahertz ultrafast polarization manipulation.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"95 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79218455","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8509945
M. Ebrahimkhani, M. Arbab
We investigate the effects of rough surface scattering on stand-off detection of materials using THz reflection spectroscopy. We apply discrete wavelet transform (DWT) to the normalized THz spectra to retrieve material absorption signatures obscured by the scattering effects. We address the impact of the non-zero phase functions of wavelet filters on the spectral location of the extracted resonant features and offer analytical solutions for compensating these phase effects.
{"title":"Extraction of THz Absorption Signatures Obscured by Rough Surface Scattering Using Discrete Wavelet Transform","authors":"M. Ebrahimkhani, M. Arbab","doi":"10.1109/IRMMW-THZ.2018.8509945","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8509945","url":null,"abstract":"We investigate the effects of rough surface scattering on stand-off detection of materials using THz reflection spectroscopy. We apply discrete wavelet transform (DWT) to the normalized THz spectra to retrieve material absorption signatures obscured by the scattering effects. We address the impact of the non-zero phase functions of wavelet filters on the spectral location of the extracted resonant features and offer analytical solutions for compensating these phase effects.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"26 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83419265","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8510195
Ruixuan Huang, Zhouyu Zhao, Weihao Liu, Weiwei Li, Heting Li, Zhigang He, Q. Jia, Lin Wang, Yalin Lu
A new high throughput material characterization system is under development at National Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China. It is a multiple light source which will supply a time resolved pump laser, a broad-band terahertz source and a pre-bunched terahertz free electron laser. We are introducing the physical design results of the project.
{"title":"Physical Design of the Pre-bunched THz FEL at NSRL*","authors":"Ruixuan Huang, Zhouyu Zhao, Weihao Liu, Weiwei Li, Heting Li, Zhigang He, Q. Jia, Lin Wang, Yalin Lu","doi":"10.1109/IRMMW-THZ.2018.8510195","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8510195","url":null,"abstract":"A new high throughput material characterization system is under development at National Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China. It is a multiple light source which will supply a time resolved pump laser, a broad-band terahertz source and a pre-bunched terahertz free electron laser. We are introducing the physical design results of the project.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"28 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83460485","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8510145
Dong-Woon Park, Gyung-Hwan Oh, H. Kim
The pulse type Terahertz time-domain spectroscopy(THz - TDS) system was used to investigate electromagnetic properties of E-glass/epoxy laminated composites. The complex relative permittivities was measured with respect to the angle between fiber orientation and electric field vector of Terahertz waves. For estimating its complex properties, theoretical models were developed and experimentally verified. Based on the results, the laminating sequence of E-glass/epoxy laminated composites was non-destructively identified by measuring complex relative permittivities in Terahertz frequency range.
{"title":"The prediction of laminate stacking sequence of E-glass/epoxy laminated composites using electromagnetic behavior of terahertz wave","authors":"Dong-Woon Park, Gyung-Hwan Oh, H. Kim","doi":"10.1109/IRMMW-THZ.2018.8510145","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8510145","url":null,"abstract":"The pulse type Terahertz time-domain spectroscopy(THz - TDS) system was used to investigate electromagnetic properties of E-glass/epoxy laminated composites. The complex relative permittivities was measured with respect to the angle between fiber orientation and electric field vector of Terahertz waves. For estimating its complex properties, theoretical models were developed and experimentally verified. Based on the results, the laminating sequence of E-glass/epoxy laminated composites was non-destructively identified by measuring complex relative permittivities in Terahertz frequency range.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"16 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87238333","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8509862
Cameron M. Hough, D. Purschke, Chenxi Huang, L. Titova, O. Kovalchuk, Brad J. Warkentin, Frank A. Hcgmann
The biological effects of intense THz pulses on human skin tissue models are investigated by applying gene ontology and pathway perturbation analyses to measured global differential gene expression profiles. Biological processes and cellular structures that regulate epidermal differentiation are highly overrepresented by THz-affected genes, and several signaling pathways that regulate the development of human cancer are predicted to be dysregulated. In particular, the calcium signaling pathway is predicted to be suppressed by THz exposures, and this effect increases with THz intensity. Mechanisms for the predicted suppression are identified and discussed in the context of potential clinical considerations of intense THz pulses.
{"title":"Intensity-dependent Suppression of Calcium Signaling in Human Skin Tissue Models Induced by Intense THz Pulses","authors":"Cameron M. Hough, D. Purschke, Chenxi Huang, L. Titova, O. Kovalchuk, Brad J. Warkentin, Frank A. Hcgmann","doi":"10.1109/IRMMW-THZ.2018.8509862","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8509862","url":null,"abstract":"The biological effects of intense THz pulses on human skin tissue models are investigated by applying gene ontology and pathway perturbation analyses to measured global differential gene expression profiles. Biological processes and cellular structures that regulate epidermal differentiation are highly overrepresented by THz-affected genes, and several signaling pathways that regulate the development of human cancer are predicted to be dysregulated. In particular, the calcium signaling pathway is predicted to be suppressed by THz exposures, and this effect increases with THz intensity. Mechanisms for the predicted suppression are identified and discussed in the context of potential clinical considerations of intense THz pulses.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"21 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84797746","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8510263
C. Ruan, Huafeng Zhang, J. Tao, Yanbin He
The development of the high output power and ultra-wide G-band travelling wave tube (TWT) using staggered double vane slow wave structure (SDV-SWS) are investigated thoroughly in this paper. It is found that the stability of the beam wave interaction is crucial with the increase of the periods of TWT to achieve the high power and gain. Thus, two kinds of scheme, which are corresponding to Bragg reflector and two stage SDV-SWS are put forward to suppress the reflection travelling wave interaction with non-working mode oscillating. The 580-590W peak power can be achieved with the 90 periods sheet beam SDV-TWT, which is corresponding the gain of about 40.6dB, the electronic efficiency of 5.5-5.6%, and the bandwidth of 35-70GHz in G-band.
{"title":"Investigation on Stability of the Beam-wave Interactions for G-band Staggered Double Vane TWT","authors":"C. Ruan, Huafeng Zhang, J. Tao, Yanbin He","doi":"10.1109/IRMMW-THZ.2018.8510263","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8510263","url":null,"abstract":"The development of the high output power and ultra-wide G-band travelling wave tube (TWT) using staggered double vane slow wave structure (SDV-SWS) are investigated thoroughly in this paper. It is found that the stability of the beam wave interaction is crucial with the increase of the periods of TWT to achieve the high power and gain. Thus, two kinds of scheme, which are corresponding to Bragg reflector and two stage SDV-SWS are put forward to suppress the reflection travelling wave interaction with non-working mode oscillating. The 580-590W peak power can be achieved with the 90 periods sheet beam SDV-TWT, which is corresponding the gain of about 40.6dB, the electronic efficiency of 5.5-5.6%, and the bandwidth of 35-70GHz in G-band.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"2013 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88168162","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8510113
A. Galeeva, A. Parafin, D. Masterov, S. A. Pavlov, A. Pankratov, S. Danilov, L. Ryabova, D. Khokhlov
We have studied photoconductivity under the action of strong laser terahertz pulses in optimally doped and underdoped films of the high-Tcsuperconductor YBa2Cu3O7-δin the vicinity of the critical temperature. In the optimally doped film, the negative photoconductivity with delayed signal increment and decay has been observed. In the underdoped film, a fast positive photoresponse has been detected on top of the negative photoconductivity background at temperatures above the transition temperature. Possible mechanisms responsible for the effects observed are discussed.
{"title":"Terahertz Photoconductivity in Optimally and Underdoped YBa2Cu3O7-δ","authors":"A. Galeeva, A. Parafin, D. Masterov, S. A. Pavlov, A. Pankratov, S. Danilov, L. Ryabova, D. Khokhlov","doi":"10.1109/IRMMW-THZ.2018.8510113","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8510113","url":null,"abstract":"We have studied photoconductivity under the action of strong laser terahertz pulses in optimally doped and underdoped films of the high-Tcsuperconductor YBa2Cu3O7-δin the vicinity of the critical temperature. In the optimally doped film, the negative photoconductivity with delayed signal increment and decay has been observed. In the underdoped film, a fast positive photoresponse has been detected on top of the negative photoconductivity background at temperatures above the transition temperature. Possible mechanisms responsible for the effects observed are discussed.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"32 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91225473","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8510480
Qijia Guo, Xianzhong Tian, Tianying Chang, H. Cui
A simple approach of phase self-calibration for millimeter wave imaging is proposed. By exploiting features of direct coupling between pairs of transmitting and receiving antennas, the channel group delay caused by the hardware can be calculated. Then the data after pulse compressionis phase-shifted before imagingto remove the phase error. This phase calibration procedure requires no additional reference target. Experimental results verify the validity and effectiveness of the proposed self-calibrationapproach, which can serve as a benchmark or basis for more sophisticated phase calibration approaches.
{"title":"Phase Self-Calibration for Millimeter Wave MIMO Imaging","authors":"Qijia Guo, Xianzhong Tian, Tianying Chang, H. Cui","doi":"10.1109/IRMMW-THZ.2018.8510480","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8510480","url":null,"abstract":"A simple approach of phase self-calibration for millimeter wave imaging is proposed. By exploiting features of direct coupling between pairs of transmitting and receiving antennas, the channel group delay caused by the hardware can be calculated. Then the data after pulse compressionis phase-shifted before imagingto remove the phase error. This phase calibration procedure requires no additional reference target. Experimental results verify the validity and effectiveness of the proposed self-calibrationapproach, which can serve as a benchmark or basis for more sophisticated phase calibration approaches.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"1 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89446419","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 : 2018-09-01DOI: 10.1109/IRMMW-THZ.2018.8509998
S. Illy, K. Avramidis, L. Jackowski, Walid Kdous, J. Jelonnek
For high power CW gyrotrons, it is mandatory to reduce the extreme power densities on the collector wall caused by the spent electron beam. A typical measure is the spreading of the electron trajectories using vertical sweeping driven by an oscillating magnetic field. Using a sinusoidal current to feed the sweeping coils has the drawback that the electron beam stays relatively long in the areas of the lower and upper turning points, which causes relatively high peaks of the average power density at these positions. A conceptual study is presented, which tries to mitigate this problem by using advanced current waveforms to speed up the turning process of the electron beam close to the critical areas and to give information to assist in the procurement of a possible sweeping power supply.
{"title":"Optimized Vertical Collector Sweeping for High Power CW Gyrotrons Using Advanced Current Waveforms","authors":"S. Illy, K. Avramidis, L. Jackowski, Walid Kdous, J. Jelonnek","doi":"10.1109/IRMMW-THZ.2018.8509998","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2018.8509998","url":null,"abstract":"For high power CW gyrotrons, it is mandatory to reduce the extreme power densities on the collector wall caused by the spent electron beam. A typical measure is the spreading of the electron trajectories using vertical sweeping driven by an oscillating magnetic field. Using a sinusoidal current to feed the sweeping coils has the drawback that the electron beam stays relatively long in the areas of the lower and upper turning points, which causes relatively high peaks of the average power density at these positions. A conceptual study is presented, which tries to mitigate this problem by using advanced current waveforms to speed up the turning process of the electron beam close to the critical areas and to give information to assist in the procurement of a possible sweeping power supply.","PeriodicalId":6653,"journal":{"name":"2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"15 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91258737","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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