Pub Date : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327566
S. Ozawa, T. Hori, Syougo Azuma, S. Funkner, G. Niehues, K. Yamamoto, T. Furuya, H. Kitahara, G. Banciu, L. Nedelcu, E. Estacio, M. Bakunov, M. Tani
In this paper we report electro-optic (EO) sampling of THz pulses using ferroelectric crystal in the non-collinear Cherenkov phase-matching scheme, where an effective velocity matching is achieved in an EO crystal with a large refractive index in the THz frequency region. We demonstrate efficient THz EO sampling using LiNbO3 and BaTiO3 crystals in the Cherenkov- phase-matching scheme. It is shown that the efficiency of EO sampling with BaTiO3 is smaller than that with LiNbO3, even though the EO coefficient (r33) of BaTiO3 is three times higher than that of LiNbO3. The reason of the poor performance of BaTiO3 is attributed to the strong absorption in the THz frequency region.
{"title":"Electro-optic sampling of terahertz pulses using BaTiO3 in non-collinear Cherenkov phase-matching scheme","authors":"S. Ozawa, T. Hori, Syougo Azuma, S. Funkner, G. Niehues, K. Yamamoto, T. Furuya, H. Kitahara, G. Banciu, L. Nedelcu, E. Estacio, M. Bakunov, M. Tani","doi":"10.1109/IRMMW-THZ.2015.7327566","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327566","url":null,"abstract":"In this paper we report electro-optic (EO) sampling of THz pulses using ferroelectric crystal in the non-collinear Cherenkov phase-matching scheme, where an effective velocity matching is achieved in an EO crystal with a large refractive index in the THz frequency region. We demonstrate efficient THz EO sampling using LiNbO<sub>3</sub> and BaTiO<sub>3</sub> crystals in the Cherenkov- phase-matching scheme. It is shown that the efficiency of EO sampling with BaTiO3 is smaller than that with LiNbO<sub>3</sub>, even though the EO coefficient (r<sub>33</sub>) of BaTiO<sub>3</sub> is three times higher than that of LiNbO<sub>3</sub>. The reason of the poor performance of BaTiO<sub>3</sub> is attributed to the strong absorption in the THz frequency region.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"68 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73766458","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327775
Chao Li, Shichao Li, G. Fang
A frequency-scanning grating-reflector antenna operating in 0.2 Terahertz band is proposed based on the diffraction enhancement mechanism. The antenna was fabricated and the proposed concept was verified based on the quasi-optical measurements.
{"title":"Frequency controlled beam-steering at 0.2THz with diffraction enhancement","authors":"Chao Li, Shichao Li, G. Fang","doi":"10.1109/IRMMW-THZ.2015.7327775","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327775","url":null,"abstract":"A frequency-scanning grating-reflector antenna operating in 0.2 Terahertz band is proposed based on the diffraction enhancement mechanism. The antenna was fabricated and the proposed concept was verified based on the quasi-optical measurements.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"247 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73769412","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327702
S. Mishakin, S. Samsonov, G. Denisov
In this paper we present design of a broadband third-harmonic operating gyro-amplifier with helically corrugated interaction circuit. An analysis of stability of the gyro-TWT with respect to parasitic wave-beam interactions has been performed and the range of parameters at which the gyro-TWT is zero-drive stable is found. According to 3D simulations, the amplifier yields a 6% amplification bandwidth with the maximum output power/gain of 80 kW / 25 dB for a 10-A, 70-kV electron beam.
{"title":"Project of a third harmonic W-band gyroamplifier","authors":"S. Mishakin, S. Samsonov, G. Denisov","doi":"10.1109/IRMMW-THZ.2015.7327702","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327702","url":null,"abstract":"In this paper we present design of a broadband third-harmonic operating gyro-amplifier with helically corrugated interaction circuit. An analysis of stability of the gyro-TWT with respect to parasitic wave-beam interactions has been performed and the range of parameters at which the gyro-TWT is zero-drive stable is found. According to 3D simulations, the amplifier yields a 6% amplification bandwidth with the maximum output power/gain of 80 kW / 25 dB for a 10-A, 70-kV electron beam.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"7 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73986776","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327737
Dachuan Liang, Minggui Wei, J. Gu, Z. Tian, C. Ouyang, Jiaguang Han, Weili Zhang
Based on a broadband time-domain terahertz radar system, we performed far-field radar cross section measurements of two metal scaled models at terahertz frequencies. The novel broadband radar can provide not only frequency-averaged RCS but also RCS distributions at arbitrary frequency. The measured terahertz RCS of the models can be scaled to that of the full-size real object at conventional radar frequencies. In addition, imaging of the scaled models based on filtered back projection algorithm has been proved to be helpful for finding the main scattering points.
{"title":"Broadband time-domain terahertz radar: Cross section measurement and imaging","authors":"Dachuan Liang, Minggui Wei, J. Gu, Z. Tian, C. Ouyang, Jiaguang Han, Weili Zhang","doi":"10.1109/IRMMW-THZ.2015.7327737","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327737","url":null,"abstract":"Based on a broadband time-domain terahertz radar system, we performed far-field radar cross section measurements of two metal scaled models at terahertz frequencies. The novel broadband radar can provide not only frequency-averaged RCS but also RCS distributions at arbitrary frequency. The measured terahertz RCS of the models can be scaled to that of the full-size real object at conventional radar frequencies. In addition, imaging of the scaled models based on filtered back projection algorithm has been proved to be helpful for finding the main scattering points.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"16 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81876146","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327708
N. Smith, L. A. Rivera, N. Burford, T. Bowman, M. El-Shenawee, G. DeSouza
Root growth and development are critical for plant survival and productivity. While systems have been developed to automate the process of extracting root traits using 2D and 3D imaging under controlled conditions, to date, no systems exist that can non-destructively and repeatedly provide high-quality information on roots of field-grown plants. At the same time, Terahertz (THz) imaging is becoming a valuable tool in many areas, including medicine, pharmacology, security, etc. and has the potential for non-destructive, repeated imaging of root systems growing in pot and eventually field conditions. In this paper, we present a framework for investigating root growth and function of plants by analyzing and classifying THz data. The proposed system can successfully identify organic materials from potting soil or sand using both THz transmitted and reflected signals.
{"title":"Towards root phenotyping in situ using THz imaging","authors":"N. Smith, L. A. Rivera, N. Burford, T. Bowman, M. El-Shenawee, G. DeSouza","doi":"10.1109/IRMMW-THZ.2015.7327708","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327708","url":null,"abstract":"Root growth and development are critical for plant survival and productivity. While systems have been developed to automate the process of extracting root traits using 2D and 3D imaging under controlled conditions, to date, no systems exist that can non-destructively and repeatedly provide high-quality information on roots of field-grown plants. At the same time, Terahertz (THz) imaging is becoming a valuable tool in many areas, including medicine, pharmacology, security, etc. and has the potential for non-destructive, repeated imaging of root systems growing in pot and eventually field conditions. In this paper, we present a framework for investigating root growth and function of plants by analyzing and classifying THz data. The proposed system can successfully identify organic materials from potting soil or sand using both THz transmitted and reflected signals.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"57 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82026130","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327658
I. Lee, M. Choe, Dong-Joon Lee, E. Choi
We present experimental results of TE6,2 mode electric field pattern results utilizing a photonic-assisted W-band measurement system and a vector network analyzer (VNA) system in the reactive near field region. We introduce the photonic-assisted W-band measurement system and demonstrate that it provides extremely precise probing capability compared to the VNA system, especially when a higher order mode pattern is scanned in the extreme near field region.
{"title":"Excellent photonic-assisted measurement system for high order mode pattern scan in reactive near field","authors":"I. Lee, M. Choe, Dong-Joon Lee, E. Choi","doi":"10.1109/IRMMW-THZ.2015.7327658","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327658","url":null,"abstract":"We present experimental results of TE6,2 mode electric field pattern results utilizing a photonic-assisted W-band measurement system and a vector network analyzer (VNA) system in the reactive near field region. We introduce the photonic-assisted W-band measurement system and demonstrate that it provides extremely precise probing capability compared to the VNA system, especially when a higher order mode pattern is scanned in the extreme near field region.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"22 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82091155","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327902
Ruan Cunjun, Liang Renjie, Dai Jun
A strong-coupling five-gap barbell output cavity is investigated combined with the design of W-band sheet beam extended interaction klystron (SBEIK), which may have many advantages of resonant mode separation, gap fields coupling and RF energy exporting with high efficiency. Then the output cavity is used to construct a high gain W-band SBEIK with eight multiple-gap cavities. With the sheet beam voltage of 75kV, and the current of 4A, the output power can attain to 32kW with the gain high than 50dB. The result agrees very well with the one-dimensional calculation program.
{"title":"Investigation on the high gain sheet beam extended interaction klystron with strong-coupling multiple-gap cavities in W-band","authors":"Ruan Cunjun, Liang Renjie, Dai Jun","doi":"10.1109/IRMMW-THZ.2015.7327902","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327902","url":null,"abstract":"A strong-coupling five-gap barbell output cavity is investigated combined with the design of W-band sheet beam extended interaction klystron (SBEIK), which may have many advantages of resonant mode separation, gap fields coupling and RF energy exporting with high efficiency. Then the output cavity is used to construct a high gain W-band SBEIK with eight multiple-gap cavities. With the sheet beam voltage of 75kV, and the current of 4A, the output power can attain to 32kW with the gain high than 50dB. The result agrees very well with the one-dimensional calculation program.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"78 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79515311","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327789
Xing Hu, C. Domier, N. Luhmann
Both capacitive and inductive frequency selective surface (FSS) filters have been applied in millimeter wave imaging plasma diagnostic systems to protect the imaging arrays from stray ECRH power as well as ensure working bandwidth control. Several FSS filters with improved performance have been designed and tested.
{"title":"Frequency selective surface applications in millimeter wave imaging diagnostics for fusion plasmas","authors":"Xing Hu, C. Domier, N. Luhmann","doi":"10.1109/IRMMW-THZ.2015.7327789","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327789","url":null,"abstract":"Both capacitive and inductive frequency selective surface (FSS) filters have been applied in millimeter wave imaging plasma diagnostic systems to protect the imaging arrays from stray ECRH power as well as ensure working bandwidth control. Several FSS filters with improved performance have been designed and tested.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"39 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79646034","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327828
B. Pepper, C. Bradford, T. Reck, P. Echternach
Quantum Capacitance Detectors (QCDs) are shot noise limited terahertz detectors. Radiation breaks Cooper pairs, causing quasiparticle poisoning of a charge qubit, read out by a microwave resonator. We find asymmetry in the distribution of telegraph transition rates, interpreted as resulting from discrete single-photon events.
{"title":"Evidence of 1.5 THz single-photon detection in quantum capacitance detectors via telegraph rate distribution asymmetry","authors":"B. Pepper, C. Bradford, T. Reck, P. Echternach","doi":"10.1109/IRMMW-THZ.2015.7327828","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327828","url":null,"abstract":"Quantum Capacitance Detectors (QCDs) are shot noise limited terahertz detectors. Radiation breaks Cooper pairs, causing quasiparticle poisoning of a charge qubit, read out by a microwave resonator. We find asymmetry in the distribution of telegraph transition rates, interpreted as resulting from discrete single-photon events.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"83 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84672640","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 : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327432
Haotian Zhu, Q. Xue
A precise and stable THz Measurement Platform is proposed in this paper. The displacement precision and angle precision of the platform are 0.02mm and 1° respectively. With OML or VDI extension module and Agilent N5245A PNA-X network analyzer, the THz Measurement Platform can measure waveguide components and antennas precisely in 0.2-1.1THz.
{"title":"A THz measurement platform design for 0.2–1.1THz","authors":"Haotian Zhu, Q. Xue","doi":"10.1109/IRMMW-THZ.2015.7327432","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327432","url":null,"abstract":"A precise and stable THz Measurement Platform is proposed in this paper. The displacement precision and angle precision of the platform are 0.02mm and 1° respectively. With OML or VDI extension module and Agilent N5245A PNA-X network analyzer, the THz Measurement Platform can measure waveguide components and antennas precisely in 0.2-1.1THz.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"57 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80434981","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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