Pub Date : 2015-11-12DOI: 10.1109/IRMMW-THZ.2015.7327638
J. Franck, K. Avramidis, I. Pagonakis, S. Illy, G. Gantenbein, M. Thumm, J. Jelonnek
The Karlsruhe Institute of Technology (KIT) is working on a possible physical design of 2 MW coaxial-cavity gyrotrons for future fusion applications, initially considering a first demonstration fusion power plant (DEMO). One focus of the investigations is how successfully such gyrotrons can be operated at significantly different frequencies. The gyrotron design as presented here is optimized for operation at one very high order main cavity mode around 237.5 GHz, with secondary modes at 170.0 GHz and 203.8 GHz. The considered technical design restrictions as well as simulation results are presented.
{"title":"Multi-frequency design of a 2 MW coaxial-cavity gyrotron for DEMO","authors":"J. Franck, K. Avramidis, I. Pagonakis, S. Illy, G. Gantenbein, M. Thumm, J. Jelonnek","doi":"10.1109/IRMMW-THZ.2015.7327638","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327638","url":null,"abstract":"The Karlsruhe Institute of Technology (KIT) is working on a possible physical design of 2 MW coaxial-cavity gyrotrons for future fusion applications, initially considering a first demonstration fusion power plant (DEMO). One focus of the investigations is how successfully such gyrotrons can be operated at significantly different frequencies. The gyrotron design as presented here is optimized for operation at one very high order main cavity mode around 237.5 GHz, with secondary modes at 170.0 GHz and 203.8 GHz. The considered technical design restrictions as well as simulation results are presented.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"3 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":"73175021","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.2015.7327685
F. Wang, K. Maussang, S. Moumdji, R. Colombelli, J. Freeman, I. Kundu, L. Li, E. Linfield, A. Davies, J. Mangeney, J. Tignon, S. Dhillon
We demonstrate the generation of 11ps terahertz pulses from metal-metal (MM) quantum cascade lasers (QCLs) at 77K via active mode-locking. Contrary to popular belief that a long gain recovery time is required, we demonstrate that the dominant factor necessary for active pulse generation is in fact the synchronization between the propagating electronic microwave modulation and the generated THz pulses in the QCL. This allows the THz pulse to propagate in phase with the microwave modulation along the gain medium, permitting pulse generation.
{"title":"Terahertz pulse generation from quantum cascade lasers","authors":"F. Wang, K. Maussang, S. Moumdji, R. Colombelli, J. Freeman, I. Kundu, L. Li, E. Linfield, A. Davies, J. Mangeney, J. Tignon, S. Dhillon","doi":"10.1109/IRMMW-THZ.2015.7327685","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327685","url":null,"abstract":"We demonstrate the generation of 11ps terahertz pulses from metal-metal (MM) quantum cascade lasers (QCLs) at 77K via active mode-locking. Contrary to popular belief that a long gain recovery time is required, we demonstrate that the dominant factor necessary for active pulse generation is in fact the synchronization between the propagating electronic microwave modulation and the generated THz pulses in the QCL. This allows the THz pulse to propagate in phase with the microwave modulation along the gain medium, permitting pulse generation.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"4 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73295820","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.2015.7327670
Shaowei Wang, Feiliang Chen, Xiaoshuang Chen, Liming Yu, W. Lu, S. Shen
Summary form only given. High-performance solar absorbers need to have high solar absorptivity and low infrared thermal emissivity at the same time. They are core part for architecture integratable solar thermal technologies such as solar water heaters and solar thermoelectric generators. In this work, we presented a kind of solar absorber with TiNxOy-based multilayers. Its solar absorbance can be as high as 97.5% and infrared thermal emissivity as low as is 4.3% with total thickness less than 300 nm. The solar absorbance can maintain above 90% for a broad incident angle to 65°.
{"title":"High performance solar selective absorbers constructed by multilayers","authors":"Shaowei Wang, Feiliang Chen, Xiaoshuang Chen, Liming Yu, W. Lu, S. Shen","doi":"10.1109/IRMMW-THZ.2015.7327670","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327670","url":null,"abstract":"Summary form only given. High-performance solar absorbers need to have high solar absorptivity and low infrared thermal emissivity at the same time. They are core part for architecture integratable solar thermal technologies such as solar water heaters and solar thermoelectric generators. In this work, we presented a kind of solar absorber with TiNxOy-based multilayers. Its solar absorbance can be as high as 97.5% and infrared thermal emissivity as low as is 4.3% with total thickness less than 300 nm. The solar absorbance can maintain above 90% for a broad incident angle to 65°.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"34 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73323695","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.2015.7327919
C. Kołaciński, D. Obrebski, J. Marczewski, P. Zagrajek
The lock-in technique is commonly used for measurements of very small DC signals in the presence of overwhelming noise. However, phase sensitive detection has its own limitations and it cannot be always easily applied in every test setup configuration. This work deals with a low noise readout circuit intended to operate with FET-based THz detectors, which in fact can replace the lock-in equipment and eliminate the need of THz wave modulation. This circuit can be also successfully deployed for processing of small DC signals produced by other sensors or detectors.
{"title":"Low noise readout circuit for THz measurements without using lock-in technique","authors":"C. Kołaciński, D. Obrebski, J. Marczewski, P. Zagrajek","doi":"10.1109/IRMMW-THZ.2015.7327919","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327919","url":null,"abstract":"The lock-in technique is commonly used for measurements of very small DC signals in the presence of overwhelming noise. However, phase sensitive detection has its own limitations and it cannot be always easily applied in every test setup configuration. This work deals with a low noise readout circuit intended to operate with FET-based THz detectors, which in fact can replace the lock-in equipment and eliminate the need of THz wave modulation. This circuit can be also successfully deployed for processing of small DC signals produced by other sensors or detectors.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"34 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":"73372106","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.2015.7327635
M. Naftaly, N. Ridler, J. Molloy, N. Shoaib, Daniel Stokes
A method is described for direct comparison of dielectric measurements obtained by a vector network analyzer and a time domain spectrometer. The method employs a material that can be inserted into a waveguide for VNA measurements or contained in a cell for TDS measurements.
{"title":"A comparison method for THz measurements using VNA and TDS","authors":"M. Naftaly, N. Ridler, J. Molloy, N. Shoaib, Daniel Stokes","doi":"10.1109/IRMMW-THZ.2015.7327635","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327635","url":null,"abstract":"A method is described for direct comparison of dielectric measurements obtained by a vector network analyzer and a time domain spectrometer. The method employs a material that can be inserted into a waveguide for VNA measurements or contained in a cell for TDS measurements.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"70 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":"76861579","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.2015.7327728
J. Molloy, M. Naftaly, Y. Andreev, K. Kokh, G. Lanskii, V. Svetlichnyi
A dense set of solid solution crystals GaSe1-xSx is examined using THz-TDS. Evolution of phonon absorption peaks with the increase of S content is shown to have complex transformation, which should be considered in the design of dispersion equations for THz applications.
{"title":"Evolution of GaSe1−xSx phonon absorption peaks with S-doping studied by THz-TDS","authors":"J. Molloy, M. Naftaly, Y. Andreev, K. Kokh, G. Lanskii, V. Svetlichnyi","doi":"10.1109/IRMMW-THZ.2015.7327728","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327728","url":null,"abstract":"A dense set of solid solution crystals GaSe1-xSx is examined using THz-TDS. Evolution of phonon absorption peaks with the increase of S content is shown to have complex transformation, which should be considered in the design of dispersion equations for THz applications.","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":"82205395","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.2015.7327492
T. Rzesnicki, I. Pagonakis, A. Samartsev, K. Avramidis, G. Gantenbein, S. Illy, J. Jelonnek, J. Jin, C. Lechte, M. Losert, B. Piosczyk, M. Thumm
A short-pulse prototype tube has been designed and manufactured at KIT in order to support the development of the European 1MW, 170 GHz, CW gyrotron for ITER. The aim of the tests is the validation of the design of the most critical components, such as electron gun, cavity, beam tunnel and quasi-optical mode converter. First experimental results will be presented in this paper.
{"title":"Recent experimental results of the European 1 MW, 170 GHz short-pulse gyrotron prototype for ITER","authors":"T. Rzesnicki, I. Pagonakis, A. Samartsev, K. Avramidis, G. Gantenbein, S. Illy, J. Jelonnek, J. Jin, C. Lechte, M. Losert, B. Piosczyk, M. Thumm","doi":"10.1109/IRMMW-THZ.2015.7327492","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327492","url":null,"abstract":"A short-pulse prototype tube has been designed and manufactured at KIT in order to support the development of the European 1MW, 170 GHz, CW gyrotron for ITER. The aim of the tests is the validation of the design of the most critical components, such as electron gun, cavity, beam tunnel and quasi-optical mode converter. First experimental results will be presented in this paper.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"4 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":"81312662","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.2015.7327618
B. Jin, L. Liang, C. H. Zhang, Y. Hou, J. Chen, P. Wu
We demonstrate a high-sensitive and multi-frequency THz measurement on the biomolecules based on a flexible metamaterial. The sensitivity of our proposed biosensor is finally achieved to be around 0.132 GHz/nm that is much higher than other reported results. The tumor molecules are coated on the metamaterial, and a very large frequency shift is observed, which implies its application in disease detection.
{"title":"High-sensitive terahertz biosensor from a thin metamaterial","authors":"B. Jin, L. Liang, C. H. Zhang, Y. Hou, J. Chen, P. Wu","doi":"10.1109/IRMMW-THZ.2015.7327618","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327618","url":null,"abstract":"We demonstrate a high-sensitive and multi-frequency THz measurement on the biomolecules based on a flexible metamaterial. The sensitivity of our proposed biosensor is finally achieved to be around 0.132 GHz/nm that is much higher than other reported results. The tumor molecules are coated on the metamaterial, and a very large frequency shift is observed, which implies its application in disease detection.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"254 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2015-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76339402","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.2015.7327904
K. Takeya, R. Takahashi, K. Kawase
Terahertz time-domain spectroscopy of hydrogen bonded materials was carried out to investigate the dielectric and optical properties of materials in the THz frequency range. The complex dielectric constant (i.e., ε' and ε") of H2O ice, D2O ice, propane hydrate, SF6 hydrate and CH4 hydrate was measured at frequencies in the range 0.4-1.2 THz and temperatures in the range 20-240 K. We discuss the frequency and temperature dependence of ε' and ε" using a mathematical model to obtain specific parameters. These results show that it is possible to analyze the dielectric constants of gas hydrates using a mathematical model of ice.
{"title":"Terahertz characterization of hydrogen bonded materials","authors":"K. Takeya, R. Takahashi, K. Kawase","doi":"10.1109/IRMMW-THZ.2015.7327904","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327904","url":null,"abstract":"Terahertz time-domain spectroscopy of hydrogen bonded materials was carried out to investigate the dielectric and optical properties of materials in the THz frequency range. The complex dielectric constant (i.e., ε' and ε\") of H<sub>2</sub>O ice, D<sub>2</sub>O ice, propane hydrate, SF<sub>6</sub> hydrate and CH<sub>4</sub> hydrate was measured at frequencies in the range 0.4-1.2 THz and temperatures in the range 20-240 K. We discuss the frequency and temperature dependence of ε' and ε\" using a mathematical model to obtain specific parameters. These results show that it is possible to analyze the dielectric constants of gas hydrates using a mathematical model of ice.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"49 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":"76426147","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.2015.7327875
K. Motovilov, Z. Gagkaeva, L. Kadyrov, E. Zhukova, A. S. Tobokhova, V. Torgashev, M. Savinov, V. Grinenko, M. Belyanchikov, K. Sidoruk, M. Dressel, B. Gorshunov
By means of terahertz and infrared (THz, IR) spectroscopies we have measured the dielectric response of nano-filaments of electrogenic bacteria Shewanella oneidensis MR-1 in a wide frequency and temperature ranges. THz-far-IR spectra are dominated by absorption due to bound water. At helium temperatures and at sub-THz frequencies a boson-peak-like excitation is detected that is typical for disordered materials. The observation is in agreement with the heat capacity measurements.
{"title":"Terahertz and infrared spectroscopy of bacterial nanofilaments","authors":"K. Motovilov, Z. Gagkaeva, L. Kadyrov, E. Zhukova, A. S. Tobokhova, V. Torgashev, M. Savinov, V. Grinenko, M. Belyanchikov, K. Sidoruk, M. Dressel, B. Gorshunov","doi":"10.1109/IRMMW-THZ.2015.7327875","DOIUrl":"https://doi.org/10.1109/IRMMW-THZ.2015.7327875","url":null,"abstract":"By means of terahertz and infrared (THz, IR) spectroscopies we have measured the dielectric response of nano-filaments of electrogenic bacteria Shewanella oneidensis MR-1 in a wide frequency and temperature ranges. THz-far-IR spectra are dominated by absorption due to bound water. At helium temperatures and at sub-THz frequencies a boson-peak-like excitation is detected that is typical for disordered materials. The observation is in agreement with the heat capacity measurements.","PeriodicalId":6577,"journal":{"name":"2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz)","volume":"17 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":"88111408","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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