Pub Date : 2019-10-01DOI: 10.1109/IRMMW-THz.2019.8874045
C. Sørensen, E. Skovsen
This work shows practical details of methodologies for conventional milling of arbitrary spherical lenses from high-density polyethylene as well as the production and polishing of off-axis parabolic mirrors using fused filament fabrication 3D printing. The techniques allow for low-volume, low-cost and fast prototyping of large optical elements for prototype setups.
{"title":"Rapid Prototyping of Simple Optical Elements for the Terahertz Domain","authors":"C. Sørensen, E. Skovsen","doi":"10.1109/IRMMW-THz.2019.8874045","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874045","url":null,"abstract":"This work shows practical details of methodologies for conventional milling of arbitrary spherical lenses from high-density polyethylene as well as the production and polishing of off-axis parabolic mirrors using fused filament fabrication 3D printing. The techniques allow for low-volume, low-cost and fast prototyping of large optical elements for prototype setups.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"145 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74826440","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 : 2019-09-21DOI: 10.1109/IRMMW-THz.2019.8874415
P. Bawuah, R. Dong, M. Al-Sharabi, D. Markl, J. Zeitler
In this study, terahertz time domain spectroscopy (THz-TDS) is used to analyze how the geometry of a compact affects its pore structure (pore shape and orientation). By using flat-faced and biconvex compacts, it was evident from our analysis that pores tend to assume specific shapes and orientations based on the compact’s geometry and this was found to significantly affect the extracted optical properties of samples prepared by mixing a material with polyethylene (PE) as diluent and subsequent compaction. However, such sensitivity to the pore properties opens a number of industrial applications such as for quality testing of pharmaceutical tablets. A comparison made between the PE based compacts and a set of pharmaceutical tablets prepared from the same formulation has revealed that flatfaced and biconvex compacts possess different pore geometries and hence different optical properties.
{"title":"Investigating the Influence of a Powder Compact’s Geometry on Its Pore Structure and Optical Properties Using Terahertz Spectroscopy","authors":"P. Bawuah, R. Dong, M. Al-Sharabi, D. Markl, J. Zeitler","doi":"10.1109/IRMMW-THz.2019.8874415","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874415","url":null,"abstract":"In this study, terahertz time domain spectroscopy (THz-TDS) is used to analyze how the geometry of a compact affects its pore structure (pore shape and orientation). By using flat-faced and biconvex compacts, it was evident from our analysis that pores tend to assume specific shapes and orientations based on the compact’s geometry and this was found to significantly affect the extracted optical properties of samples prepared by mixing a material with polyethylene (PE) as diluent and subsequent compaction. However, such sensitivity to the pore properties opens a number of industrial applications such as for quality testing of pharmaceutical tablets. A comparison made between the PE based compacts and a set of pharmaceutical tablets prepared from the same formulation has revealed that flatfaced and biconvex compacts possess different pore geometries and hence different optical properties.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"92 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83836521","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874498
M. Zaborowski, D. Tomaszewski, P. Zagrajek, J. Marczewski
A new type of JLFET based detector is described in the paper. This JLFET is equipped with additional electrode contacting side of the channel (giving T-like shape of the channel). The device offers higher photoresponse and better SNR and NEP than its standard counterpart. The most promising for application is -0.5 V.. 0 V gate voltage range, where 84 dB SNR is noted.
{"title":"T-Channel JLFET THz Detector","authors":"M. Zaborowski, D. Tomaszewski, P. Zagrajek, J. Marczewski","doi":"10.1109/IRMMW-THz.2019.8874498","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874498","url":null,"abstract":"A new type of JLFET based detector is described in the paper. This JLFET is equipped with additional electrode contacting side of the channel (giving T-like shape of the channel). The device offers higher photoresponse and better SNR and NEP than its standard counterpart. The most promising for application is -0.5 V.. 0 V gate voltage range, where 84 dB SNR is noted.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"15 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73466157","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874222
T. Kawasaki, H. Zen, A. Irizawa, K. Tsukiyama, K. Nakamura
Infrared free electron laser (IR-FEL) enables us to investigate novel laser-driven phenomena in various research fields, due to its high photon density in a picosecond time scale as well as wide wavelength tunability in the infrared region. As an application of IR-FEL to biomedical field, we show here efficient dissociation of amyloid fibrils that are cause of serious amyloidosis by using the FEL tuned to amide band.
{"title":"Application of Infrared-Free Electron Laser for Amyloidosis Therapy","authors":"T. Kawasaki, H. Zen, A. Irizawa, K. Tsukiyama, K. Nakamura","doi":"10.1109/IRMMW-THz.2019.8874222","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874222","url":null,"abstract":"Infrared free electron laser (IR-FEL) enables us to investigate novel laser-driven phenomena in various research fields, due to its high photon density in a picosecond time scale as well as wide wavelength tunability in the infrared region. As an application of IR-FEL to biomedical field, we show here efficient dissociation of amyloid fibrils that are cause of serious amyloidosis by using the FEL tuned to amide band.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"48 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74072103","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874269
Xi Yu, S. Ono, J. Bae
To improve the generation efficiency of terahertz wave from periodic terahertz-wave generator, femtosecond laser was employed to fabricated moth-eye structure on the reverse of the antenna substrate (LT-GaAs). The AR structured antennas had a 2.5–4.4 times improvement of the output at the frequency of 0.342 THz (calculated fout), 0.283 THz, 0.226 THz (experimental fout of generator without and with moth-eye structure), the improvement are 3 times, 2.5 times, and 4.4 times, respectively.
{"title":"Application of laser generated moth-eye structure for a periodic terahertz-wave generator","authors":"Xi Yu, S. Ono, J. Bae","doi":"10.1109/IRMMW-THz.2019.8874269","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874269","url":null,"abstract":"To improve the generation efficiency of terahertz wave from periodic terahertz-wave generator, femtosecond laser was employed to fabricated moth-eye structure on the reverse of the antenna substrate (LT-GaAs). The AR structured antennas had a 2.5–4.4 times improvement of the output at the frequency of 0.342 THz (calculated fout), 0.283 THz, 0.226 THz (experimental fout of generator without and with moth-eye structure), the improvement are 3 times, 2.5 times, and 4.4 times, respectively.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"11 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75190300","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874120
E. Abreu, D. Babich, E. Janod, S. Houver, B. Corraze, L. Cario, S. Johnson
GaTa4 Se8 is a Mott insulator known to exhibit an electric Mott transition, characterized by a drop in electrical resistivity, when an electric field larger than 1 – 10 kV/cm is applied for a few tens of microseconds using electrodes deposited on the sample. Here, we show that a resistivity drop can be induced in this material within less than a picosecond. These dynamics occur after excitation by a high field THz pump pulse and persist for a few picoseconds, well beyond the duration of the pump pulse.
{"title":"THz Driven Dynamics in Mott Insulator GaTa4 Se8","authors":"E. Abreu, D. Babich, E. Janod, S. Houver, B. Corraze, L. Cario, S. Johnson","doi":"10.1109/IRMMW-THz.2019.8874120","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874120","url":null,"abstract":"GaTa4 Se8 is a Mott insulator known to exhibit an electric Mott transition, characterized by a drop in electrical resistivity, when an electric field larger than 1 – 10 kV/cm is applied for a few tens of microseconds using electrodes deposited on the sample. Here, we show that a resistivity drop can be induced in this material within less than a picosecond. These dynamics occur after excitation by a high field THz pump pulse and persist for a few picoseconds, well beyond the duration of the pump pulse.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"37 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74519172","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874455
E. N. Chesnokov, L. Krasnoperov, V. Kubarev, P. Koshlyakov
Ultrafast dynamics of OH radical was investigated by its Free Induction Decay (FID) signal. In our experiments doublet rotational line of the radical was excited by pulse of free-electron laser. Effect of a magnetic field on polarization of the FID was studied by numerical simulation. Experimental investigations of the magnetic field effect is in progress now.
{"title":"Ultrafast dynamics of hydroxyl radical observed by its FID radiation in magnetic field","authors":"E. N. Chesnokov, L. Krasnoperov, V. Kubarev, P. Koshlyakov","doi":"10.1109/IRMMW-THz.2019.8874455","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874455","url":null,"abstract":"Ultrafast dynamics of OH radical was investigated by its Free Induction Decay (FID) signal. In our experiments doublet rotational line of the radical was excited by pulse of free-electron laser. Effect of a magnetic field on polarization of the FID was studied by numerical simulation. Experimental investigations of the magnetic field effect is in progress now.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"26 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74699617","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874223
D. Suzuki, K. Ishibashi, Y. Kawano
We present a broadband bendable THz camera, composed of a free-standing carbon nanotube film array, which is intended for an built-in infrastructure sensor. As advantages over conventional solid-state THz sensors, our bendable THz camera can be fabricated through simple and low-cost processes and can simplify optical/electrical measurement systems, which enables us to mount the sensor on objects regardless of their shapes, sizes, and locations. We demonstrate the use of our novel THz camera for real-time nondestructive imaging of industrial products, indicating possibilities of one of the powerful components such as built-in/wearable THz sensors for future imaging and remote sensing.
{"title":"Broadband Bendable Terahertz Camera for Built-in Infrastructure Sensor","authors":"D. Suzuki, K. Ishibashi, Y. Kawano","doi":"10.1109/IRMMW-THz.2019.8874223","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874223","url":null,"abstract":"We present a broadband bendable THz camera, composed of a free-standing carbon nanotube film array, which is intended for an built-in infrastructure sensor. As advantages over conventional solid-state THz sensors, our bendable THz camera can be fabricated through simple and low-cost processes and can simplify optical/electrical measurement systems, which enables us to mount the sensor on objects regardless of their shapes, sizes, and locations. We demonstrate the use of our novel THz camera for real-time nondestructive imaging of industrial products, indicating possibilities of one of the powerful components such as built-in/wearable THz sensors for future imaging and remote sensing.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"20 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74741009","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874124
L. Liebelt, S. Weber, J. Klier, T. Pfeiffer, D. Molter, F. Ellrich, G. von Freymann
Terahertz time-domain spectroscopy (TDS) is a very attractive technique in the field of nondestructive layerthickness determination. The characteristics of the generated terahertz pulses - bandwidth and dynamic range - have direct influence on the thickness-determination performance. The resulting effects are investigated in this contribution.
{"title":"Influence of bandwidth and dynamic range on thickness determination using terahertz time-domain spectroscopy","authors":"L. Liebelt, S. Weber, J. Klier, T. Pfeiffer, D. Molter, F. Ellrich, G. von Freymann","doi":"10.1109/IRMMW-THz.2019.8874124","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874124","url":null,"abstract":"Terahertz time-domain spectroscopy (TDS) is a very attractive technique in the field of nondestructive layerthickness determination. The characteristics of the generated terahertz pulses - bandwidth and dynamic range - have direct influence on the thickness-determination performance. The resulting effects are investigated in this contribution.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"127 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73332122","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 : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874216
N. Peskov, E. Abubakirov, A. Denisenko, N. Ginzburg, A. Savilov, A. Vikharev, V. Zaslavsky
Conception of Compton-type FELs is under development currently at IAP RAS (Nizhny Novgorod). This concept is aimed at reducing energy of a driving relativistic electron beam and thereby increasing efficiency of the electron-wave interaction in FEL, as well as achieving relative compactness of the generator. The basis of this concept is RF-undulators of a new type - the so-called “flying” undulators. Present paper is devoted to design parameters and results of simulation of the Cherenkov maser intended for powering the RF-undulator of such type in the Ka-band. In order to achieve the required sub-gigawatt power level of the pumping wave in a strongly oversized oscillator, we exploit the original idea of using two-dimensional distributed feedback implemented in the 2D doubly-periodical slow-wave structures.
{"title":"Powerful Spatially-Extended Cherenkov Masers for Pumping Systems of Compton FELs","authors":"N. Peskov, E. Abubakirov, A. Denisenko, N. Ginzburg, A. Savilov, A. Vikharev, V. Zaslavsky","doi":"10.1109/IRMMW-THz.2019.8874216","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874216","url":null,"abstract":"Conception of Compton-type FELs is under development currently at IAP RAS (Nizhny Novgorod). This concept is aimed at reducing energy of a driving relativistic electron beam and thereby increasing efficiency of the electron-wave interaction in FEL, as well as achieving relative compactness of the generator. The basis of this concept is RF-undulators of a new type - the so-called “flying” undulators. Present paper is devoted to design parameters and results of simulation of the Cherenkov maser intended for powering the RF-undulator of such type in the Ka-band. In order to achieve the required sub-gigawatt power level of the pumping wave in a strongly oversized oscillator, we exploit the original idea of using two-dimensional distributed feedback implemented in the 2D doubly-periodical slow-wave structures.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"6 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75372404","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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