Pub Date : 2019-09-01DOI: 10.1109/IRMMW-THz.2019.8874279
Seonmyeong Kim, Jeongmin Jang, K. Eom, D. Tommaso, G. Park
We present a novel approach to determine the hydration number of aqueous electrolytes by means of ab initio molecular dynamics. An hydration status analysis is devised to quantify the cooperative effect of ions on the reorientational dynamics of different water subpopulations in electrolyte solutions. The methodology is applied to predict the hydration numbers, h, as the number moles of water molecules per mole of dissolved salt that no longer participate in bulk-like reorientational dynamics. The obtained hydration number of MgCl2 (h = 15) is consistent with THz-DR experiment, measuring reorientational dynamics of water in solutions. By providing a link with the micro-scale dynamical behaviour of ions and water molecules, this approach represents a generally applicable, welldefined methodology to quantify hydration numbers of ions and molecules in aqueous solutions.
{"title":"Hydration numbers from ab initio water reorientation dynamics","authors":"Seonmyeong Kim, Jeongmin Jang, K. Eom, D. Tommaso, G. Park","doi":"10.1109/IRMMW-THz.2019.8874279","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874279","url":null,"abstract":"We present a novel approach to determine the hydration number of aqueous electrolytes by means of ab initio molecular dynamics. An hydration status analysis is devised to quantify the cooperative effect of ions on the reorientational dynamics of different water subpopulations in electrolyte solutions. The methodology is applied to predict the hydration numbers, h, as the number moles of water molecules per mole of dissolved salt that no longer participate in bulk-like reorientational dynamics. The obtained hydration number of MgCl2 (h = 15) is consistent with THz-DR experiment, measuring reorientational dynamics of water in solutions. By providing a link with the micro-scale dynamical behaviour of ions and water molecules, this approach represents a generally applicable, welldefined methodology to quantify hydration numbers of ions and molecules in aqueous solutions.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"17 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":"73863005","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.2019.8874194
R. Ako, Wendy S. L. Lee, M. Bhaskaran, S. Sriram, W. Withayachumnankul
Linear-to-linear polarization conversion of electromagnetic wave has application in various fields including communications, imaging and sensing. Available polarization-control devices enabled by metasurfaces are limited in bandwidth, efficiency and acceptance angle. Herein, a reflective half-wave mirror composed of T-shaped resonators is proposed and experimentally evaluated. Measured results show a bandwidth of 95% and 100% around a center frequency of 0.7 THz for the normal and 45° angle of incidence. The measured results agree well with the simulation. An average polarization conversion ratio (PCR) greater than 80% is observed across 0° to 45° incidence angles.
{"title":"Broadband and wide-angle terahertz reflective half-wave mirror","authors":"R. Ako, Wendy S. L. Lee, M. Bhaskaran, S. Sriram, W. Withayachumnankul","doi":"10.1109/IRMMW-THz.2019.8874194","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874194","url":null,"abstract":"Linear-to-linear polarization conversion of electromagnetic wave has application in various fields including communications, imaging and sensing. Available polarization-control devices enabled by metasurfaces are limited in bandwidth, efficiency and acceptance angle. Herein, a reflective half-wave mirror composed of T-shaped resonators is proposed and experimentally evaluated. Measured results show a bandwidth of 95% and 100% around a center frequency of 0.7 THz for the normal and 45° angle of incidence. The measured results agree well with the simulation. An average polarization conversion ratio (PCR) greater than 80% is observed across 0° to 45° incidence angles.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"28 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":"74793115","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.2019.8874224
Wei-dong Hu, Zhongbo Zhu, Xianqi Lin, Xiaojun Li
A compact transmit-array (TA) antenna with reduced profile and improved radiation gain is proposed in this paper. The proposed transmitting surface, with a thickness of 0.127 mm (0.042 $lambda_{0}$ @105 GHz), is employed here to adjust the phase distribution across the aperture of a shortened feed horn. The full TA prototype is fabricated and measured. A 3-dB gain bandwidth of 9.52%, from 100 GHz to 110 GHz, is achieved. The measured maximum gain at 105 GHz is 22.76 dBi, which gets an 8-dB enhancement with respect to the primary feed, without expanding the radiation aperture size. This method considerably reduces the complexity of TA and achieves a much more compact structure.
{"title":"A Low-Profile Sub-Terahertz Transmit-Array Antenna with High Gain Enhancement","authors":"Wei-dong Hu, Zhongbo Zhu, Xianqi Lin, Xiaojun Li","doi":"10.1109/IRMMW-THz.2019.8874224","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874224","url":null,"abstract":"A compact transmit-array (TA) antenna with reduced profile and improved radiation gain is proposed in this paper. The proposed transmitting surface, with a thickness of 0.127 mm (0.042 $lambda_{0}$ @105 GHz), is employed here to adjust the phase distribution across the aperture of a shortened feed horn. The full TA prototype is fabricated and measured. A 3-dB gain bandwidth of 9.52%, from 100 GHz to 110 GHz, is achieved. The measured maximum gain at 105 GHz is 22.76 dBi, which gets an 8-dB enhancement with respect to the primary feed, without expanding the radiation aperture size. This method considerably reduces the complexity of TA and achieves a much more compact structure.","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":"78634473","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.2019.8874172
T. Bach, Uroš Puc, Vincent Michel, C. Medrano, P. Gunter, M. Jazbinšek
We demonstrate ultrabroadband THz-wave generation and detection in a compact system based on a femtosecond fiber laser at 1560 nm and optical rectification in organic electro-optic crystals DSTMS. Terahertz time-domain spectroscopy with a spectrum extending up to 20 THz with a maximum bandwidth exceeding 70 dB is possible with this system.
{"title":"Terahertz Time-Domain Spectroscopy up to 20 THz Based on Organic Electro-Optic Crystals","authors":"T. Bach, Uroš Puc, Vincent Michel, C. Medrano, P. Gunter, M. Jazbinšek","doi":"10.1109/IRMMW-THz.2019.8874172","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874172","url":null,"abstract":"We demonstrate ultrabroadband THz-wave generation and detection in a compact system based on a femtosecond fiber laser at 1560 nm and optical rectification in organic electro-optic crystals DSTMS. Terahertz time-domain spectroscopy with a spectrum extending up to 20 THz with a maximum bandwidth exceeding 70 dB is possible with this system.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"5 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78392209","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.2019.8874040
F. Barho, H. Philip, Z. Loghmari, M. Bahriz, A. Baranov, R. Teissier
We report a study of quantum cascade lasers (QCL), made of InAs and AlSb, operating in the long wavelength mid-infrared range. Lasers based on a design with slightly diagonal intersubband transitions demonstrated improved performances as compared to the previously reported devices employing a vertical scheme. The fabricated lasers operated in the CW regime at 40°C up to a wavelength of 18 μm.
{"title":"Long wavelength (λ = 10 - 18 μm) mid-IR quantum cascade lasers operating in a continuous wave at room temperature","authors":"F. Barho, H. Philip, Z. Loghmari, M. Bahriz, A. Baranov, R. Teissier","doi":"10.1109/IRMMW-THz.2019.8874040","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874040","url":null,"abstract":"We report a study of quantum cascade lasers (QCL), made of InAs and AlSb, operating in the long wavelength mid-infrared range. Lasers based on a design with slightly diagonal intersubband transitions demonstrated improved performances as compared to the previously reported devices employing a vertical scheme. The fabricated lasers operated in the CW regime at 40°C up to a wavelength of 18 μm.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"122 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75950041","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.2019.8874502
A. Squires, D. Seo, S. Lam, X. Gao, T. Zhang, Z. Han, J. Du
This paper investigates the microfabrication process of graphene in developing high frequency, particularly millimeter-wave and terahertz, electronic devices. We consider graphene production, transfer, fabrication and electrical characterization. Preliminary results reveal key insights including the benefit of polymer removal in transferring graphene to substrates as well as identifying Ar ion beam etching as being effective in patterning graphene thin films. This work lays a solid foundation in developing a holistic and reliable method to pattern graphene for use in high frequency electronics components.
{"title":"Graphene microfabrication for developing mm-wave and THz devices","authors":"A. Squires, D. Seo, S. Lam, X. Gao, T. Zhang, Z. Han, J. Du","doi":"10.1109/IRMMW-THz.2019.8874502","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874502","url":null,"abstract":"This paper investigates the microfabrication process of graphene in developing high frequency, particularly millimeter-wave and terahertz, electronic devices. We consider graphene production, transfer, fabrication and electrical characterization. Preliminary results reveal key insights including the benefit of polymer removal in transferring graphene to substrates as well as identifying Ar ion beam etching as being effective in patterning graphene thin films. This work lays a solid foundation in developing a holistic and reliable method to pattern graphene for use in high frequency electronics components.","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":"76006557","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.2019.8874024
A. Jumaah, S. Al-Daffaie, O. Yilmazoglu, F. Küppers, T. Kusserow
The effect of using graphene as 2D nanoelectrode for continuous wave (CW) terahertz (THz) photomixers were investigated. The multilayer graphene (6–8 and 3–5 MLG) sheets were used as six-finger interdigital nanoelectrodes on a low- temperature-grown (LTG) GaAs photoconductor. The MLG nanoelectrode shows unique properties with high short-circuit current capabilities and reliable high photocurrents. The number of graphene layers play a big role on the electrical and the optical properties of graphene nanoelectrode. In one hand, a thinner graphene increases the transparency of the nanoelectrodes to improve the power conversion efficiency, and on the other hand, a thicker graphene is required to carry high current densities and enhance the photomixer performance.
{"title":"Experimental Investigation of Graphene Layers as 2D Nanoelectrode for Continuous Wave Terahertz Generation","authors":"A. Jumaah, S. Al-Daffaie, O. Yilmazoglu, F. Küppers, T. Kusserow","doi":"10.1109/IRMMW-THz.2019.8874024","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874024","url":null,"abstract":"The effect of using graphene as 2D nanoelectrode for continuous wave (CW) terahertz (THz) photomixers were investigated. The multilayer graphene (6–8 and 3–5 MLG) sheets were used as six-finger interdigital nanoelectrodes on a low- temperature-grown (LTG) GaAs photoconductor. The MLG nanoelectrode shows unique properties with high short-circuit current capabilities and reliable high photocurrents. The number of graphene layers play a big role on the electrical and the optical properties of graphene nanoelectrode. In one hand, a thinner graphene increases the transparency of the nanoelectrodes to improve the power conversion efficiency, and on the other hand, a thicker graphene is required to carry high current densities and enhance the photomixer performance.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"46 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":"75049283","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.2019.8874271
F. Qaderi, A. Muller, A. Krammer, Miroslav J. Veljovic, Z. Ollmann, M. Hayati, A. Skrivervik, A. Schueler, T. Feurer, A. Ionescu
We establish insulator-to-metal transition (IMT) in Vanadium dioxide (VO2) by millimeter-wave (mm-wave) actuation, using two coupled dipole antennas: a simple one as a continuous mm-wave-source and the other one with an embedded VO2 part as an absorber. We measured |S12| by a vector network analyzer (VNA), to show how the induced mm-wave power in insulating biased VO2 causes IMT. The bias voltage is set to enhance the sensitivity in VO2. The VO2 embedded antenna shows sensitivity to the mm-wave power down to 3.2 pW. The experiment proves the detection concept also for terahertz frequencies.
{"title":"Millimeter-wave-triggering of insulator-to-metal transition in Vanadium dioxide","authors":"F. Qaderi, A. Muller, A. Krammer, Miroslav J. Veljovic, Z. Ollmann, M. Hayati, A. Skrivervik, A. Schueler, T. Feurer, A. Ionescu","doi":"10.1109/IRMMW-THz.2019.8874271","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874271","url":null,"abstract":"We establish insulator-to-metal transition (IMT) in Vanadium dioxide (VO2) by millimeter-wave (mm-wave) actuation, using two coupled dipole antennas: a simple one as a continuous mm-wave-source and the other one with an embedded VO2 part as an absorber. We measured |S12| by a vector network analyzer (VNA), to show how the induced mm-wave power in insulating biased VO2 causes IMT. The bias voltage is set to enhance the sensitivity in VO2. The VO2 embedded antenna shows sensitivity to the mm-wave power down to 3.2 pW. The experiment proves the detection concept also for terahertz frequencies.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"259 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":"74936691","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.2019.8874187
F. Mezzapesa, K. Garrasi, V. Pistore, Lianhe H. Li, A. Davies, E. Linfield, S. Dhillon, M. Vitiello
We demonstrate THz optical frequency comb (FC) operation based on ultra-broadband, record dynamic range Quantum Cascade Lasers (QCLs) which exploit a heterogeneous active region design to achieve low and flat chromatic dispersion at the center of the gain curve. By implementing a Gires-Tournois Interferometer (GTI), as tightly coupled at one end of the QCL cavity, we provide lithographically-independent control of the free-running coherence properties of such THz-QCL FC and attain wide dispersion compensation regions, where stable and narrow (~3 kHz linewidth) single beatnotes extend over an operation range that is significantly larger than that of dispersiondominated bare laser cavity counterparts.
{"title":"THz quantum cascade laser frequency combs","authors":"F. Mezzapesa, K. Garrasi, V. Pistore, Lianhe H. Li, A. Davies, E. Linfield, S. Dhillon, M. Vitiello","doi":"10.1109/IRMMW-THz.2019.8874187","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874187","url":null,"abstract":"We demonstrate THz optical frequency comb (FC) operation based on ultra-broadband, record dynamic range Quantum Cascade Lasers (QCLs) which exploit a heterogeneous active region design to achieve low and flat chromatic dispersion at the center of the gain curve. By implementing a Gires-Tournois Interferometer (GTI), as tightly coupled at one end of the QCL cavity, we provide lithographically-independent control of the free-running coherence properties of such THz-QCL FC and attain wide dispersion compensation regions, where stable and narrow (~3 kHz linewidth) single beatnotes extend over an operation range that is significantly larger than that of dispersiondominated bare laser cavity counterparts.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"78 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":"74955221","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.2019.8874254
Yuriy K. Kalynov, I. Bandurkin, V. Manuilov, I. Osharin, A. Savilov, N. A. Zavolsky
The possibility of creating a third-cyclotron-harmonic large-orbit gyrotron with a radiation frequency of 1 THz and an output power of several kilowatts for its use in promising plasma studies is studied.
{"title":"Powerful 1 THz Third-Harmonic Gyrotron for Plasma Applications","authors":"Yuriy K. Kalynov, I. Bandurkin, V. Manuilov, I. Osharin, A. Savilov, N. A. Zavolsky","doi":"10.1109/IRMMW-THz.2019.8874254","DOIUrl":"https://doi.org/10.1109/IRMMW-THz.2019.8874254","url":null,"abstract":"The possibility of creating a third-cyclotron-harmonic large-orbit gyrotron with a radiation frequency of 1 THz and an output power of several kilowatts for its use in promising plasma studies is studied.","PeriodicalId":6686,"journal":{"name":"2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)","volume":"148 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":"77922605","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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