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  • 1.
    Ali, Muhsin
    et al.
    Univ Carlos III Madrid, Ave Univ 30, Madrid 28911, Spain..
    Tebart, Jonas
    Univ Duisburg Essen, ZHO Optoelect, Lotharstr 55, D-47057 Duisburg, Germany..
    Rivera-Lavado, Alejandro
    Univ Carlos III Madrid, Ave Univ 30, Madrid 28911, Spain.;Direcc Gen Inst Geog Nacl, Yebes Observ, Yebes, Spain..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Inst High Pressure Phys, CENTERA Labs, Warsaw, Poland..
    Enrique Garcia-Munoz, Luis
    Univ Carlos III Madrid, Ave Univ 30, Madrid 28911, Spain..
    Stoehr, Andreas
    Univ Duisburg Essen, ZHO Optoelect, Lotharstr 55, D-47057 Duisburg, Germany..
    Carpintero, Guillermo
    Univ Carlos III Madrid, Ave Univ 30, Madrid 28911, Spain..
    Terahertz Band Data Communications using Dielectric Rod Waveguide2022In: 2022 Optical Fiber Communications Conference and Exhibition, OFC 2022 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2022, article id W1H.5Conference paper (Refereed)
    Abstract [en]

    A terahertz data link is presented using dielectric rod waveguide (DRW) at 300 GHz and complex modulations for speeds up to 120 Gbps. Performance comparison with WR-3 rectangular waveguide validates the low-dispersion behaviour of DRW.

  • 2.
    Anoshkin, Ilya
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Nefedova, Irina
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Nefedov, Igor
    Räisänen, Antti
    Single walled carbon nanotube quantification method employing the Raman signal intensity2017In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 116, p. 547-552Article in journal (Refereed)
    Abstract [en]

    A new technique for measuring the number of single walled carbon nanotubes (SWCNTs) and their concentration in a carbon nanotube layer is developed in this work. It is based on the G peak intensity of the Raman spectrum, together with precise mass and optical absorbance measurements. The dependence of the number of the carbon nanotubes on the phonon scattering intensity is observed. This method opens an opportunity for the quantitative mapping of sp2 carbon atom distribution in the SWCNT layers with a resolution limited by the focused laser spot size.

  • 3.
    Anoshkin, Ilya V.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Campion, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Freeze-Dried Carbon Nanotube Aerogels for High-Frequency Absorber Applications2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, ISSN 1944-8244, Vol. 10, no 23, p. 19806-19811Article in journal (Refereed)
    Abstract [en]

    A novel technique for millimeter wave absorber material embedded in a metal waveguide is proposed. The absorber material is a highly porous carbon nanotube (CNT) aerogel prepared by a freeze-drying technique. CNT aerogel structures are shown to be good absorbers with a low reflection coefficient, less than -12 dB at 95 GHz. The reflection coefficient of the novel absorber is 3-4 times lower than that of commercial absorbers with identical geometry. Samples prepared by freeze-drying at -25 degrees C demonstrate resonance behavior, while those prepared at liquid nitrogen temperature (-196 degrees C) exhibit a significant decrease in reflection coefficient, with no resonant behavior. CNT absorbers of identical volume based on wet-phase drying preparation show significantly worse performance than the CNT aerogel absorbers prepared by freeze-drying. Treatment of the freeze-dried CNT aerogel with n- and p-dopants (monoethanolamine and iodine vapors, respectively) shows remarkable improvement in the performance of the waveguide embedded absorbers, reducing the reflection coefficient by 2 dB across the band.

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  • 4.
    Bryantseva, T. A.
    et al.
    Russian Acad Sci, Inst Radioengn & Elect, Fryazino Branch, Fryazino 141120, Moscow Oblast, Russia..
    Lyubchenko, V. E.
    Russian Acad Sci, Inst Radioengn & Elect, Fryazino Branch, Fryazino 141120, Moscow Oblast, Russia..
    Lyubchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Markov, I. A.
    Russian Acad Sci, Inst Radioengn & Elect, Fryazino Branch, Fryazino 141120, Moscow Oblast, Russia..
    Ten, Yu. A.
    Russian Acad Sci, Inst Radioengn & Elect, Fryazino Branch, Fryazino 141120, Moscow Oblast, Russia..
    Peculiarities of the Formation and Growth of Thin Gold Films on the Surface of Gallium Arsenide during Thermal Evaporation in Vacuum2023In: Journal of communications technology & electronics, ISSN 1064-2269, E-ISSN 1555-6557, Vol. 68, no 5, p. 566-574Article in journal (Refereed)
    Abstract [en]

    Changes in the morphology and structure of the GaAs surface during the deposition of an Au film by thermal evaporation in vacuum have been studied. It has been found that the deposition of an Au film with the participation of a flow of particles and light from a heated evaporator causes the appearance of photo effects in the near-surface GaAs layers, including light diffraction on surface acoustic waves, the growth of whiskers, and electron emission, which leads to the formation of microcracks on the GaAs surface and the growth of GaAs crystallites. It is shown that the structure and composition of the film boundaries of Au and GaAs surfaces depend on the electron concentration in gallium arsenide, which ultimately determines the properties of the electrophysical parameters of the Au-GaAs contacts.

  • 5.
    Campion, James
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Ivanov, Roman
    Department of Mechanical and Industrial Engineering, Tallinn University of Technology, Estonia.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Hussainova, Irina
    Department of Mechanical and Industrial Engineering, Tallinn University of Technology, Estonia.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories, Institute of High-Pressure Physics, PAS, Warsaw, Poland.
    Ultra-wideband waveguide embedded graphene-based THz absorber2021In: The 11th International Conference on Metamaterials, Photonic Crystals and Plasmonics, META 2021, META Conference , 2021, p. 926-927Conference paper (Refereed)
    Abstract [en]

    A novel type of absorber material integrated in a standard metal waveguide is developed for the ultra-wide frequency range of 67-500 GHz. The absorber is based on graphene augmented inorganic nanofibers which are deposited inside a metallic waveguide cassette, allowing them to be utilised in standard waveguide systems. The material’s microstructures result in a low level of reflectance (< -15 dB) and good absorbance (> 20 dB) from 110-500 GHz due to the porosity of the sample and attenuation caused by graphene, making them highly suited for wideband terahertz applications.

  • 6.
    Campion, James
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. TeraSi AB Stockholm 139 33 Sweden.
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Ivanov, Roman
    Tallinn University of Technology.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Department of Mechanical and Electrical Engineering Tallinn University of Technology Tallinn 19086 Estonia.
    Hussainova, Irina
    Tallinn University of Technology.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories Institute of High‐Pressure Physics PAS Warsaw 01‐142 Poland.
    Ultra‐Wideband Integrated Graphene‐Based Absorbers for Terahertz Waveguide Systems2022In: Advanced Electronic Materials, E-ISSN 2199-160X, Vol. 8, no 9, p. 2200106-2200106Article in journal (Refereed)
    Abstract [en]

    This article presents novel graphene-based absorber materials which can be directly integrated in terahertz waveguide systems. A simple, low-cost integration method is developed, allowing graphene augmented inorganic nanofibers to be embedded inside a metallic waveguide. In contrast to existing absorbers, the ability to embed such materials in a metallic waveguide allows them to be integrated into complete terahertz systems for large-scale applications. The electromagnetic properties of such materials are then examined using standard network analysis techniques. A wideband measurement setup is developed to enable measurement of a single sample from 67 to 500 GHz, eliminating the need to fabricate multiple samples. The porosity of the integrated material leads to excellent electromagnetic performance across a wide range of frequencies. The samples are found to have a reflection coefficient less than −10 dB for frequencies above200 GHz, while their attenuation per unit length exceeds 35 dB mm−1. The low reflectivity of the material allows it to be used in systems applications where undesired reflections must be avoided. The electromagnetic shielding effectiveness of the material is assessed, with a total effectiveness of 20–45 dB observed for 0.84 mm thick samples.

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    fulltext
  • 7.
    Carpintero, Guillermo
    et al.
    Univ Carlos III Madrid, Av Univ 30, Madrid 28911, Spain..
    Rivera, Alejandro
    Univ Carlos III Madrid, Av Univ 30, Madrid 28911, Spain..
    Ali, Muhsin
    Univ Carlos III Madrid, Av Univ 30, Madrid 28911, Spain..
    Gallego Cabo, Daniel
    Univ Carlos III Madrid, Av Univ 30, Madrid 28911, Spain..
    Enrique Garcia-Munoz, Luis
    Univ Carlos III Madrid, Av Univ 30, Madrid 28911, Spain..
    de Felipe, David
    Fraunhofer Heinrich Hertz Inst, Photon Components, D-10587 Berlin, Germany..
    Keil, Norbert
    Fraunhofer Heinrich Hertz Inst, Photon Components, D-10587 Berlin, Germany..
    Liebermeister, Lars
    Fraunhofer Heinrich Hertz Inst, Photon Components, D-10587 Berlin, Germany..
    Lauck, Sebastian
    Fraunhofer Heinrich Hertz Inst, Photon Components, D-10587 Berlin, Germany..
    Globisch, Bjoern
    Fraunhofer Heinrich Hertz Inst, Photon Components, D-10587 Berlin, Germany..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Prados-Castro, Enrique
    Anritsu EMEA, 200 Capabil Green, Luton LU1 3LU, Beds, England..
    Pindado-Buendia, Jose Maria
    Anritsu EMEA, 200 Capabil Green, Luton LU1 3LU, Beds, England..
    Rossetti, Riccardo
    Anritsu EMEA, 200 Capabil Green, Luton LU1 3LU, Beds, England..
    Nagel, Michael
    Protem GmbH, Otto Blumenthal Str 25, D-52074 Aachen, Germany..
    Interconnection challenges on integrated terahertz photonic systems2021In: OPTICAL INTERCONNECTS XXI / [ed] Schroder, H Chen, RT, SPIE-Intl Soc Optical Eng , 2021, article id 116920NConference paper (Refereed)
    Abstract [en]

    We present the current challenges for high frequency interconnects, especially for calibrated measures of the frequency response of components operating above 100 GHz. This is the challenge addressed by the TERAmeasure Future and Emerging Technologies project, aiming to combine photonics and electronics to develop new paradigm in the millimetre and Terahertz frequency ranges, overcoming the current obstacles to better measurements, eliminating the frequency banded nature of rectangular waveguides and providing metrology-grade results across the full frequency range.

  • 8.
    Demchenko, P.
    et al.
    ITMO Univ, St Petersburg 197101, Russia..
    Gomon, D.
    ITMO Univ, St Petersburg 197101, Russia..
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. ITMO Univ, St Petersburg 197101, Russia..
    Khodzitsky, M.
    ITMO Univ, St Petersburg 197101, Russia..
    Influence of optical pumping on properties of carbon nanotubes with different geometric parameters in THz frequency range2018In: 2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ), IEEE , 2018Conference paper (Refereed)
    Abstract [en]

    Impact of infrared radiation illumination (980 nm) on the properties of cabon nanotubes (CNT), such as complex conductivity and permittivity, with different geometric parameters (lengths, diameters and with presence/absence graphene oxide layer) in the frequency range of 0.2-1.0 THz was studied.

  • 9. Demchenko, P.
    et al.
    Gomon, D.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, M.
    Study of optical pumping influence on carbon nanotubes permittivity in THz frequency range2018In: Journal of Physics: Conference Series, Institute of Physics Publishing , 2018, no 5Conference paper (Refereed)
    Abstract [en]

    Equivalent complex permittivity of carbon nanotubes (CNT) was measured with/without light illumination at the frequency range of 0.2-1 THz. It was shown that we can tune the dispersion of the CNT complex conductivity during varying of optical pumping (wavelength of 980 nm). These results mean that CNT is perspective candidate for development of THz tunable attenuators and phase shifters. 

  • 10. Demchenko, P.
    et al.
    Gomon, D.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, M.
    Study of influence of densification on control of conductivity and spectral characteristics of thin films of carbon nanotubes in terahertz frequency range2018In: EPJ Web of Conferences, EDP Sciences, 2018, article id 06022Conference paper (Refereed)
  • 11.
    Drozdowska, Katarzyna
    et al.
    Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications, and Informatics, Gdańsk University of Technology, G. Narutowicza 11/12, Gdańsk, 80-233, Poland.
    Rehman, Adil
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Smulko, Janusz
    Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications, and Informatics, Gdańsk University of Technology, G. Narutowicza 11/12, Gdańsk, 80-233, Poland.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Stonio, Bartłomiej
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland; Centre for Advanced Materials and Technologies, CEZAMAT, Warsaw University of Technology, Warsaw, 02-822, Poland.
    Sai, Pavlo
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Przewłoka, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland; Institute of Optoelectronics, Military University of Technology, gen. Sylwestra Kaliskiego 2, Warsaw, 00-908, Poland.
    Filipiak, Maciej
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland; Centre for Advanced Materials and Technologies, CEZAMAT, Warsaw University of Technology, Warsaw, 02-822, Poland.
    Pavłov, Krystian
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland; Centre for Advanced Materials and Technologies, CEZAMAT, Warsaw University of Technology, Warsaw, 02-822, Poland.
    Cywiński, Grzegorz
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Rumyantsev, Sergey
    CENTERA Laboratories, Institute of High Pressure Physics PAS, Warsaw, 01-142, Poland.
    Optimum Choice of Randomly Oriented Carbon Nanotube Networks for UV-Assisted Gas Sensing Applications2023In: ACS Sensors, E-ISSN 2379-3694, Vol. 8, no 9, p. 3547-3554Article in journal (Refereed)
    Abstract [en]

    We investigated the noise and photoresponse characteristics of various optical transparencies of nanotube networks to identify an optimal randomly oriented network of carbon nanotube (CNT)-based devices for UV-assisted gas sensing applications. Our investigation reveals that all of the studied devices demonstrate negative photoconductivity upon exposure to UV light. Our studies confirm the effect of UV irradiation on the electrical properties of CNT networks and the increased photoresponse with decreasing UV light wavelength. We also extend our analysis to explore the low-frequency noise properties of different nanotube network transparencies. Our findings indicate that devices with higher nanotube network transparencies exhibit lower noise levels. We conduct additional measurements of noise and resistance in an ethanol and acetone gas environment, demonstrating the high sensitivity of higher-transparent (lower-density) nanotube networks. Overall, our results indicate that lower-density nanotube networks hold significant promise as a viable choice for UV-assisted gas sensing applications.

  • 12.
    Drozdz, Piotr A.
    et al.
    Inst High Pressure Phys PAS, CENTERA Labs, Warsaw, Poland..
    Campion, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. TeraSi AB, Stockholm, Sweden..
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Krajewska, Akelsandra
    Inst High Pressure Phys PAS, CENTERA Labs, Warsaw, Poland..
    Przewloka, Aleksandra
    Inst High Pressure Phys PAS, CENTERA Labs, Warsaw, Poland..
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Haras, Maciej
    Inst High Pressure Phys PAS, CENTERA Labs, Warsaw, Poland.;Warsaw Univ Technol, Ctr Adv Mat & Technol CEZAMAT, Warsaw, Poland..
    Nasibulin, Albert
    Aalto Univ, Dept Chem & Mat Sci, Espoo, Finland.;Skolkovo Inst Sci & Technol, Moscow, Russia..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS). Inst High Pressure Phys PAS, CENTERA Labs, Warsaw, Poland..
    Integrated CNT Aerogel Absorbers for Sub-THz Waveguide Systems2022In: 2022 IEEE/MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS 2022), Institute of Electrical and Electronics Engineers (IEEE) , 2022, p. 906-909Conference paper (Refereed)
    Abstract [en]

    The ongoing development of sub-THz systems and applications has created a need for new absorbing materials which can be integrated in a simple, low-cost manner. Here, we investigate the properties of CNT-based aerogels in the range of 67-110 GHz and develop a simple technique for their integration. The aerogels are synthesised using standard techniques and then shaped using a laser cutter to allow for direct integration. The S-parameters of a total of four aerogel absorber samples are measured. The absorbers offer a return loss of up to 12 - 14.5 dB across the measurement band, with a maximum absorption 2.54 of 5 dB/mm The observed performance makes CNT aerogels extremely promising candidates for use in sub-THz waveguide systems and applications.

  • 13.
    Drozdz, Piotr A.
    et al.
    Inst High Pressure Phys PAS, CENTERA Labs, Ul Sokolowska, PL-01142 Warsaw, Poland..
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Campion, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. TeraSi AB, Kolviksvagen 38, SE-13933 Stockholm, Sweden..
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Przewloka, Aleksandra
    Inst High Pressure Phys PAS, CENTERA Labs, Ul Sokolowska, PL-01142 Warsaw, Poland.;Mil Univ Technol, Inst Optoelect, Ul Gen Sylwestra Kaliskiego 2, PL-00098 Warsaw, Poland..
    Krajewska, Aleksandra
    Inst High Pressure Phys PAS, CENTERA Labs, Ul Sokolowska, PL-01142 Warsaw, Poland..
    Haras, Maciej
    Inst High Pressure Phys PAS, CENTERA Labs, Ul Sokolowska, PL-01142 Warsaw, Poland.;Warsaw Univ Technol, CEZAMAT, Ul Poleczki 19, PL-02822 Warsaw, Poland..
    Nasibulin, Albert
    Skolkovo Inst Sci & Technol, Nobel Str 3, Moscow 121205, Russia.;Aalto Univ, Dept Chem & Mat Sci, POB 15100, FI-00076 Espoo, Finland..
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Inst High Pressure Phys PAS, CENTERA Labs, Ul Sokolowska, PL-01142 Warsaw, Poland..
    Highly efficient absorption of THz radiation using waveguide-integrated carbon nanotube/cellulose aerogels2022In: APPLIED MATERIALS TODAY, ISSN 2352-9407, Vol. 29, article id 101684Article in journal (Refereed)
    Abstract [en]

    This article presents the preparation, compositional and electromagnetic characterization of modified few-walled carbon nanotubes/nanofibrillar cellulose (FWCNT/NFC) aerogels integrated in a standard terahertz hollow waveguide and studies their operation as absorbers of electromagnetic waves in the WR-3.4 band (220-330 GHz). Hybrid aerogels consisting of different weight ratios of NFC and modified FWCNT are prepared by freezedrying and characterized through scanning electron microscopy and Raman spectroscopy, and then placed within waveguide cassettes in a simple, low-cost and efficient way that requires no special equipment. A broadband measurement setup is employed for examining the electromagnetic response of the materials. It is found that the materials are excellent absorbers with an average shielding efficiency of 66 dB in the best case and return loss above 10 dB across the band with a flat frequency response. FWCNT aerogels are assessed as a promising candidate for terahertz waveguide terminations.

  • 14.
    Dróżdż, Piotr A.
    et al.
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
    Haras, Maciej
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland.
    Przewłoka, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Institute of Optoelectronics, Military University of Technology, gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
    Filipiak, Maciej
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland;Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
    Słowikowski, Mateusz
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland;Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
    Stonio, Bartłomiej
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland;Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
    Czerniak-Łosiewicz, Karolina
    Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
    Mierczyk, Zygmunt
    Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland.
    Skotnicki, Thomas
    CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland;Centre for Advanced Materials and Technologies (CEZAMAT), Warsaw University of Technology, Poleczki 19, 02-822 Warsaw, Poland;Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories, Institute of High Pressure Physics Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
    A graphene/h-BN MEMS varactor for sub-THz and THz applications2023In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 15, no 30, p. 12530-12539Article in journal (Refereed)
    Abstract [en]

    Recent development of terahertz systems has created the need for new elements operating in this frequency band, i.e., fast tunable devices such as varactors. Here, we present the process flow and characterization of a novel electronic variable capacitor device that is made with the use of 2D metamaterials such as graphene (GR) or hexagonal boron nitride (h-BN). Comb-like structures are etched into a silicon/silicon nitride substrate and a metal electrode is deposited at the bottom. Next, a PMMA/GR/h-BN layer is placed on top of the sample. As voltage is applied between GR and metal, the PMMA/GR/h-BN layer bends towards the bottom electrode thus decreasing the distance between electrodes and changing the capacitance. The high tunability and complementary metal oxide semiconductor (CMOS)-compatible process flow of the platform for our device and its millimeter size make it promising for applications in future electronics and terahertz technologies. The goal of our research is to integrate our device with dielectric rod waveguides, thus making THz phase shifters.

  • 15. Gomon, D.
    et al.
    Gusev, S.
    Demchenko, P.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Khodzitsky, M.
    Opticaly tunable conductivity of carbon nanotubes in terahertz frequency range2018In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Conference paper (Refereed)
    Abstract [en]

    Impact of infrared radiation illumination (980 nm) on the properties of carbon nanotubes (CNT), such as complex conductivity and permittivity, with different geometric parameters in the frequency range of 0.2-1.0 THz was studied. 

  • 16.
    Kumar, Ashish
    et al.
    Univ Carlos III Madrid, Optoelect & Laser Technol Grp GOTL, Madrid 28911, Spain..
    Gallego, Daniel C.
    Univ Carlos III Madrid, Optoelect & Laser Technol Grp GOTL, Madrid 28911, Spain..
    Headland, Daniel
    Univ Carlos III Madrid, Optoelect & Laser Technol Grp GOTL, Madrid 28911, Spain..
    Ali, Mushin
    Univ Carlos III Madrid, Optoelect & Laser Technol Grp GOTL, Madrid 28911, Spain..
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Carpintero, Guillermo
    Univ Carlos III Madrid, Optoelect & Laser Technol Grp GOTL, Madrid 28911, Spain..
    Contactless Cost-effective Polarizer for mm-Wave Dielectric Rod Waveguide2022In: 2022 47TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ 2022), Institute of Electrical and Electronics Engineers (IEEE) , 2022Conference paper (Refereed)
    Abstract [en]

    We present a method to control the polarization of guided waves in a mm-wave dielectric rod waveguide. A pair of optical posts is situated on either side of the waveguide, and this markedly raises the cutoff of the undesired mode. The isolation is 20 dB over a frequency span from (55-87) GHz. This can be viewed as a proof-of-concept for reconfigurable, general-purpose polarization control and dispersion engineering in mm-wave and terahertz-range dielectric waveguides.

  • 17.
    Lyubchenko, Dmitri
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Millimeter Wave Beam Steering Based on Optically Controlled Carbon Nanotube Layers2018Conference paper (Refereed)
    Abstract [en]

    In this paper, the dielectric constant changing of thin carbon nanotube layers under light illumination was used for phase shifter development in dielectric rod waveguides. This designed phase shifter was introduced to the dielectric rod waveguide dual-antenna array. The measurements of the beam steering at 90 GHz of the dielectric rod antenna array, covered with carbon nanotubes, were carried out.

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    fulltext
  • 18. Lyubchenko, V. E.
    et al.
    Kalinin, V. I.
    Kotov, V. D.
    Lyubchenko, D. V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Radchenko, D. E.
    Telegin, S. A.
    Yunevich, E. O.
    Microstrip Antenna–Oscillators Integrated with a Waveguide Built in a Dielectric Substrate2018In: Journal of communications technology & electronics, ISSN 1064-2269, E-ISSN 1555-6557, Vol. 63, no 9, p. 1059-1063Article in journal (Refereed)
    Abstract [en]

    The design of a microwave oscillator based on a microstrip log-periodic antenna integrated with a field effect transistor and a waveguide built in a dielectric substrate has been developed and analyzed. The waveguide geometry provides the possibility of propagation and radiation at both the fundamental frequency of the log-periodic antenna and harmonics. Computer simulation of the oscillator design in a frequency range near resonance frequencies of the log-periodic antenna is conducted. The possibility of summation of powers of several antenna–oscillators arranged ias a linear phased array is investigated. 

  • 19.
    Makhalov, Petr B.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Semiconductor-Metal-Grating Slow Wave Amplifier for Sub-THz Frequency Range2019In: IEEE Transactions on Electron Devices, ISSN 0018-9383, E-ISSN 1557-9646, Vol. 66, no 10, p. 4413-4418Article in journal (Refereed)
    Abstract [en]

    The concept of semiconductor slow wave amplifier aimed at sub-terahetz frequencies is studied numerically. The scheme of the transversal amplifier with metal grating is proposed. The requirements on semiconductor parameters that provide positive net amplification are given and discussed, and the choice of GaN is explained. For the proposed device, different regimes are studied, and the dependence of the net amplification on device parameters is given. One regime has high linear gain, more than 50 dB/mm. The proof-of-principle structure for the excitation of the device in this regime is proposed and simulated.

  • 20.
    Makhalov, Petr B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering (EES).
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Simulations of a semiconductor/metal-grating slow-wave amplifier for sub-THz range2017In: 2017 42nd International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, Institute of Electrical and Electronics Engineers (IEEE) , 2017, article id 8067047Conference paper (Refereed)
    Abstract [en]

    In this work, the concept of a solid-state amplifier based on the slow-wave interaction with drifting electron flow in a metal periodic structure is proposed for application in the low THz frequency range. Results of calculations at 330 GHz show the linear gain up to 50 dB/cm, including ohmic losses in the metal.

  • 21.
    Makhalov, Petr B.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering (EES).
    Oberhammer, Joachim
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Study of the slow-wave interaction in a three valley semiconductor in high electric fields2017In: 42nd International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, IEEE Computer Society, 2017, article id 8066856Conference paper (Refereed)
    Abstract [en]

    The interaction of a slow-wave in a corrugated dielectric waveguide with drifting electron gas in a semiconductor with the multi-valleys conduction band is studied in the linear model. Contribution of each valley into the net loss/amplification is investigated. Substantial amplification is possible in large fields due to slow-wave interaction with carriers in satellite valleys.

  • 22.
    Morales, Alvaro
    et al.
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Okonkwo, Chigo
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Tafur Monroy, Idelfonso
    Inst. for Photonic Integration, Eindhoven University of Technology.
    Photonic-Based Beamforming System for Sub-THz Wireless Communications2019Conference paper (Refereed)
    Abstract [en]

    This work presents a sub-THz transmitter scheme for wireless communications with beam steering capabilities based on photonics means. A true time delay 1x4 beamforming photonic chip is designed in Si3N4 technology to continuously tune the progressive time delay between consecutive antenna elements. Simulation results show a progressive delay up to 15 ps with a bandwidth of 1.3 GHz, enabling broadband operation at frequencies above 75 GHz. The sub-THz signals are generated on photoconductive antennas on chip by photonic heterodyning. The design of a dielectric rod antenna array is also presented to efficiently radiate the generated wave.

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    fulltext
  • 23.
    Przewloka, Aleksanda
    et al.
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland.;Mil Univ Technol, Inst Optoelect, Ul Gen Sylwestra Kaliskiego 2, PL-00098 Warsaw, Poland..
    Rehman, Adil
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Karpierz-Marczewska, Ewelina
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Krajewska, Aleksandra
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Liszewska, Malwina
    Mil Univ Technol, Inst Optoelect, Ul Gen Sylwestra Kaliskiego 2, PL-00098 Warsaw, Poland..
    Drozdz, Piotr
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Pavlov, Krystian
    Ctr Adv Mat & Technol CEZAMAT, Poleczki 19, PL-02822 Warsaw, Poland..
    Dub, Maksym
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland.;Natl Acad Sci Ukraine, KV E Lashkaryov Inst Semicond Phys, 41 Pr Nauki, UA-03680 Kiev, Ukraine..
    Novytskyi, Serhi
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Jankiewicz, Bartlomiej
    Mil Univ Technol, Inst Optoelect, Ul Gen Sylwestra Kaliskiego 2, PL-00098 Warsaw, Poland..
    Mierczyk, Zygmunt
    Mil Univ Technol, Inst Optoelect, Ul Gen Sylwestra Kaliskiego 2, PL-00098 Warsaw, Poland..
    Rumyantsev, Sergey
    PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. PAS, CENTERA Labs, Inst High Pressure Phys, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Conductivity inversion of methyl viologen-modified random networks of single-walled carbon nanotubes2023In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 202, p. 214-220Article in journal (Refereed)
    Abstract [en]

    One of the challenges of using carbon nanotubes electronics is achieving precise control of the conductivity type. It is particularly difficult to obtain the n-type conductive nanotubes. One of the most common methods of CNTs modification allowing to change their conductivity type is chemical functionalization. This paper describes the results of studies on non-covalent modification of randomly oriented single-walled carbon nan-otubes (SWCNT) layers with methyl viologen (MV), which allows for the change of the conductivity of SWCNT from p- to n-type. The properties of pristine and MV-modified SWCNT have been compared using Scanning Electron Microscopy, Raman spectroscopy, and X-ray Photoelectron Spectroscopy. The SWCNT conductivity type change was confirmed by photo-conductance under ultraviolet illumination and measurements in the field effect transistor configuration.

  • 24.
    Przewłoka, Aleksandra
    et al.
    CENTERA Laboratories, Institute of High-Pressure Physics PAS, Warsaw, Poland; Institute of Optoelectronics, Military University of Technology, Warsaw, Poland.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High-Pressure Physics PAS, Warsaw, Poland.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail K.
    THz Biomedicine Laboratory, ITMO University, Saint Petersburg, Russia.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories, Institute of High-Pressure Physics PAS, Warsaw, Poland.
    Single-walled carbon nanotube phase shifters for low THz frequencies2021In: The 11th International Conference on Metamaterials, Photonic Crystals and Plasmonics, META 2021, META Conference , 2021, p. 1058-1059Conference paper (Refereed)
    Abstract [en]

    In this work single-walled carbon nanotube length dependence on phase tuning properties of dielectric rod waveguide is experimentally studied in ultra-wide frequency band of 0.1-0.5 THz.

  • 25.
    Przewłoka, Aleksandra
    et al.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Nefedova, Irina
    Department of Electronics and Nanoengineering, Aalto University.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Nefedov, Igor S.
    Saratov National Research State University.
    Demchenko, Petr S.
    ITMO University.
    Zykov, Dmitry V.
    ITMO University.
    Chebotarev, Valentin S.
    ITMO University.
    But, Dmytro B.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Stelmaszczyk, Kamil
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Dub, Maksym
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Zasada, Dariusz
    Military University of Technology.
    Lisauskas, Alvydas
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail K.
    ITMO University.
    Knap, Wojciech
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Characterization of Silver Nanowire Layers in the Terahertz Frequency Range2021Data set
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    data set
  • 26. Przewłoka, Aleksandra
    et al.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Nefedova, Irina
    Krajewska, Aleksandra
    Nefedov, Igor S.
    Demchenko, Petr S.
    Zykov, Dmitry V.
    Chebotarev, Valentin S.
    But, Dmytro B.
    Stelmaszczyk, Kamil
    Dub, Maksym
    Zasada, Dariusz
    Lisauskas, Alvydas
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail K.
    Knap, Wojciech
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Characterization of Silver Nanowire Layers in the Terahertz Frequency Range2021In: Materials, E-ISSN 1996-1944, Vol. 14, no 23, p. 7399-Article in journal (Refereed)
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    fulltext
  • 27.
    Przewłoka, Aleksandra
    et al.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Nefedova, Irina
    Department of Electronics and Nanoengineering, Aalto University.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Nefedov, Igor S.
    People’s Friendship University of Russia (RUDN University).
    Demchenko, Petr S.
    THz Biomedicine Laboratory, ITMO University.
    Zykov, Dmitry V.
    THz Biomedicine Laboratory, ITMO University.
    Chebotarev, Valentin S.
    THz Biomedicine Laboratory, ITMO University.
    But, Dmytro
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Stelmaszczyk, Kamil
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Lisauskas, Alvydas
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail K.
    THz Biomedicine Laboratory, ITMO University.
    Knap, Wojciech
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Terahertz conductivity of silver nanowire networksManuscript (preprint) (Other academic)
    Abstract [en]

    Silver nanowires are an excellent candidate as highly conductive material for applications in flexible and transparent electronics such as solar cells, displays, and antennas. This paper reports on the electronic properties of thin silver nanowire networks with varying geometries and densities of the nanowires in the sub-terahertz range (0.2 THz to 1.2 THz) using time-domain and frequency-domain spectroscopies. The THz conductivity is extracted from transmission measurements and a modified Drude-Smith model is proposed to describe the conductivity of the networks. The low-density networks follow the Drude-Smith conductivity with the backscattering parameter close to -1, while the high-density networks form a semicontinuous metallic layer with a Drude-like response. The demonstrated approach is relevant for characterizing conductive nanomaterials in order to design novel THz optoelectronic devices.

  • 28.
    Rehman, A.
    et al.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Krajewska, A.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Stonio, B.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland.;Warsaw Univ Technol, Ctr Adv Mat & Technol CEZAMAT, Poleczki 19, PL-02822 Warsaw, Poland..
    Pavlov, K.
    Warsaw Univ Technol, Ctr Adv Mat & Technol CEZAMAT, Poleczki 19, PL-02822 Warsaw, Poland..
    Cywinski, G.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland.;Warsaw Univ Technol, Ctr Adv Mat & Technol CEZAMAT, Poleczki 19, PL-02822 Warsaw, Poland..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland.
    Knap, W.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland.;Warsaw Univ Technol, Ctr Adv Mat & Technol CEZAMAT, Poleczki 19, PL-02822 Warsaw, Poland.;Univ Montpellier, Lab Charles Coulomb, F-34950 Montpellier, France.;CNRS, UMR 5221, F-34950 Montpellier, France..
    Rumyantsev, S.
    Inst High Pressure Phys PAS, CENTERA Labs, Sokolowska 29-37, PL-01142 Warsaw, Poland..
    Smulko, J. M.
    Gdansk Univ Technol, Fac Elect Telecommun & Informat, Dept Metrol & Optoelect, G Narutowicza 11-12, PL-80233 Gdansk, Poland..
    Generation-recombination and 1/f noise in carbon nanotube networks2021In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 118, no 24, article id 242102Article in journal (Refereed)
    Abstract [en]

    The low-frequency noise is of special interest for carbon nanotubes devices, which are building blocks for a variety of sensors, including radio frequency and terahertz detectors. We studied noise in as-fabricated and aged carbon nanotube networks (CNNs) field-effect transistors. Contrary to the majority of previous publications, as-fabricated devices demonstrated the superposition of generation-recombination (GR) and 1/f noise spectra at a low-frequency range. Although all the devices revealed identical current-voltage characteristics, GR noise was different for different transistors. This effect is explained by the different properties and concentrations of trap levels responsible for the noise. Unexpectedly, exposure of these devices to the atmosphere reduced both the resistance and GR noise due to nanotube's p-doping by adsorbed water molecules from the ambient atmosphere. The presence of the generation recombination noise and its dependences on the environment provides the basis for selective gas sensing based on the noise measurements. Our study reveals the noise properties of CNNs that need to be considered when developing carbon nanotubes-based selective gas sensors.

  • 29.
    Rehman, Adil
    et al.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Krajewska, Aleksandra
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Stonio, B.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    But, Dmytro B.
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Pavlov, Krystian
    Centre for Adv. Materials and Technologies CEZAMAT, Warsaw University of Technology.
    Cywinski, Grzegorz
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Knap, Wojciech
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Rumyantsev, Sergey
    CENTERA Laboratories, Institute of High Pressure Physics PAS.
    Low Frequency Noise of Carbon Nanotubes THz detectors2021In: 2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz), Institute of Electrical and Electronics Engineers (IEEE) , 2021Conference paper (Refereed)
    Abstract [en]

    We report studies of noise properties of carbon nanotube (CNT) networks-based devices used for the terahertz detectors. Low-frequency noise characteristics of CNTs as a function of temperature, UV illumination, and back-gate voltages were examined. Our results demonstrated the existence of at least two important resistance components of nanotubes rather than generally accepted dominant tube-to-tube junction resistance. We showed that noise spectroscopy can be employed to probe the structural quality of nanotube networks. Measurements as a function of back gate voltages revealed the existence of generation-recombination noise, related to deep tarps, which play a significant role in the performances of CNT networks-based terahertz detectors.

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    fulltext
  • 30.
    Rehman, Adil
    et al.
    Institute of High Pressure Physics PAS.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Krajewska, Aleksandra
    Institute of High Pressure Physics PAS.
    But, Dmytro B.
    Institute of High Pressure Physics PAS.
    Liszewska, Malwina
    Military University of Technology.
    Bartosewicz, Bartosz
    Military University of Technology.
    Pavlov, Krystian
    Warsaw University of Technology.
    Cywiński, Grzegorz
    Institute of High Pressure Physics PAS.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Knap, Wojciech
    Institute of High Pressure Physics PAS.
    Rumyantsev, Sergey L.
    Institute of High Pressure Physics PAS.
    Effect of ultraviolet light on 1/f noise in carbon nanotube networks2021In: Materials research bulletin, ISSN 0025-5408, E-ISSN 1873-4227, Vol. 134, article id 111093Article in journal (Refereed)
    Abstract [en]

    Noise defines the minimum level of the operational signal and is an important figure of merit for various devices. Here, we studied the low-frequency (1/f) noise characteristics of randomly oriented networks of carbon nanotubes and examined the effect of ultraviolet (UV) light on it. The amplitude of 1/f noise in our devices was strongly affected by the quality of nanotubes. This makes noise spectroscopy an effective tool to characterize the structural quality of carbon nanotube devices. UV illumination increased the device resistance and noise amplitude preserving the spectra shapes. This effect remained for tens of minutes even after the UV light was turned off. We observed a completely different trend of noise spectra and resistance with temperature as compared to UV illumination. These results indicated at least two important components of resistance that contribute to the total resistance of the device and are essential to describe the nanotube networks correctly.

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    fulltext
  • 31.
    Rivera-Lavado, Alejandro
    et al.
    Univ Carlos III Madrid, Dept Teoria Senal & Comunicac, Leganes 28911, Spain.;Yebes Observ, Inst Geog Nacl, Direcc Gen, Yebes 19141, Spain..
    Ali, Muhsin
    Univ Carlos III Madrid, Dept Tecnol Elect, Madrid 28911, Spain..
    Gallego-Cabo, Daniel
    Univ Carlos III Madrid, Dept Tecnol Elect, Madrid 28911, Spain..
    Garcia-Munoz, Luis-Enrique
    Univ Carlos III Madrid, Dept Teoria Senal & Comunicac, Madrid 28911, Spain..
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Carpintero, Guillermo
    Univ Carlos III Madrid, Dept Tecnol Elect, Madrid 28911, Spain..
    Contactless RF Probe Interconnect Technology Enabling Broadband Testing to the Terahertz Range2023In: IEEE Transactions on Terahertz Science and Technology, ISSN 2156-342X, E-ISSN 2156-3446, Vol. 13, no 1, p. 34-43Article in journal (Refereed)
    Abstract [en]

    Radiofrequency (RF) probes based on 50-omega planar transmission lines play a key role in almost every stage of RF device development, establishing the physical contact between high-end instrumentation and the device. With the continuous downscaling of semiconductor technologies to reach into the millimeter-wave (30-300 GHz) and Terahertz (300 GHz to 3 THz) bands and devices exhibiting broader frequency response, current RF probe technology is the Achilles heel for precise and repeatable measurements. Here, we propose a novel RF probe technology based on the near-field coupling of single-mode dielectric waveguide structures, which according to our full-wave simulations provide an extremely broad frequency range covering from 0 Hz up to 340 GHz, the largest continuous bandwidth reported to date. A concept demonstrator using this approach shows contactless RF probing on test structures, which shows the path toward continuous measurements across the microwave, millimeter-wave, and Terahertz range.

  • 32.
    Rivera-Lavado, Alejandro
    et al.
    Spanish Natl Geog Inst, Yebes Observ, Yebes, Spain. ivera-Lavado, Alejandro; Garcia-Munoz, Luis-Enrique; Atia Abdalmalak, Kerlos; Santamaria-Botello, Gabriel; Segovia-Vargas, Daniel.
    García-Muñoz, Luis-Enrique
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Preu, Sascha
    Abdalmalak, Kerlos
    Santamaría-Botello, Gabriel
    Segovia-Vargas, Daniel
    Räisänen, Antti V.
    Planar Lens–Based Ultra-Wideband Dielectric Rod Waveguide Antenna for Tunable THz and Sub-THz Photomixer Sources2019In: Journal of Infrared, Millimeter and Terahertz Waves, ISSN 1866-6892, E-ISSN 1866-6906, Vol. 40, no 8, p. 838-855Article in journal (Refereed)
    Abstract [en]

    In this manuscript, the use of dielectric rod waveguide antenna (DRW) with an embedded planar lens is proposed as a highly directional alternative to an electrically large hyper-hemispheric silicon lens for emission at millimeter and sub-millimeter wave frequencies. DRW antennas radiate properly if only the fundamental mode is excited to the structure. Since photomixer-based terahertz sources excite many modes, single-lobe radiation patterns are obtained only for lower frequencies of their potential working band. The use of embedded planar lenses is proposed for rectifying the wavefront phase and suppressing such higher-order modes in DRW, allowing an ultra-wideband operation.

  • 33.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Demchenko, Petr
    ITMO University.
    Gomon, Daniel
    ITMO University.
    Lioubtchenko, Dmitri V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail
    ITMO University.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Optically controlled dielectric properties of single-walled carbon nanotubes for terahertz wave applications2018In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 10, no 26, p. 12291-12296Article in journal (Refereed)
    Abstract [en]

    Materials with tunable dielectric properties are valuable for a wide range of electronic devices, but are often lossy at terahertz frequencies. Here we experimentally report the tuning of the dielectric properties of single-walled carbon nanotubes under light illumination. The effect is demonstrated by measurements of impedance variations at low frequency as well as complex dielectric constant variations in the wide frequency range of 0.1-1 THz by time domain spectroscopy. We show that the dielectric constant is significantly modified for varying light intensities. The effect is also practically applied to phase shifters based on dielectric rod waveguides, loaded with carbon nanotube layers. The carbon nanotubes are used as tunable impedance surface controlled by light illumination, in the frequency range of 75-500 GHz. These results suggest that the effect of dielectric constant tuning with light, accompanied by low transmission losses of the carbon nanotube layer in such an ultra-wide band, may open up new directions for the design and fabrication of novel Terahertz and optoelectronic devices.

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  • 34.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Anoshkin, Ilya V.
    Generalov, Andrey
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Wavelength-dependent photoconductivity of single-walled carbon nanotube layers2019In: RSC Advances, E-ISSN 2046-2069, Vol. 9, no 26, p. 14677-14682Article in journal (Refereed)
    Abstract [en]

    A number of electronic devices such as phase shifters, polarizers, modulators, and power splitters are based on tunable materials. These materials often do not meet all the requirements namely low losses, fast response time, and technological compatibility. Novel nanomaterials, such as single-walled carbon nanotubes, are therefore widely studied to fill this technological gap. Here we show how the dielectric constant of single-walled carbon nanotube layers can be substantially modified by illuminating them due to unique light–matter interactions. We relate the optical excitation of the nanotube layers to the illumination wavelength and intensity, by resistance and capacitance measurements. The dielectric constant is modified under laser illumination due to the change of material polarization and free carrier generation, and is shown to not be temperature-related. The findings indicate that SWCNT layers are a prospective tunable optoelectronic material for both high and low frequency applications.

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    fulltext
  • 35.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Carbon Nanotube Layer Modeling for Computer Simulation of Optically Controlled Phase Shifters2018Conference paper (Refereed)
    Abstract [en]

    We propose an approach for efficient modeling of thin carbon nanotube layers for full-wave device simulations without increasing the number of simulation mesh cells. A surface impedance, used in computer simulations, is calculated from the dielectric constant of the material. The dielectric constant is modeled by a Drude–Lorentz resonance, fitted to experimental results. The approach allowed to study the nanotube-induced losses and finite-size resonance effects in optically-controlled, dielectric rod waveguide-based phase shifters. The correctness of the model was verified both by the simulated and the measured S-parameters in the W-band.

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    fulltext
  • 36.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Millimeter Wave Phase Shifter Based on Optically Controlled Carbon Nanotube Layers2018Conference paper (Refereed)
    Abstract [en]

    Surfaces with tunable impedance are usually lossy at high frequencies, which limits the design of millimeter wave and Terahertz devices. This work experimentally demonstrates a phase shifter based on single-walled carbon nanotubes and dielectric rod waveguides in the 220–330 GHz frequency range. Thin carbon nanotube layers are used as a tunable impedance surface with the dielectric properties optically controlled by laser illumination.

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    fulltext
  • 37.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Single-walled carbon nanotube layers for millimeter-wave beam steering2019In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372Article in journal (Refereed)
    Abstract [en]

    The ability to efficiently transmit and manipulate high-frequency signals poses major challenges resulting in a lack of active and reconfigurable millimeter-wave and terahertz devices that are needed to enable beyond-5G broadband communication systems. Here, thin single-walled carbon nanotube (SWCNT) layers are introduced as a tunable impedance surface for millimeter-waves. Carbon nanotube layers are integrated with dielectric rod waveguides. Their surface impedance, tuned by light, is shown to modify the wave propagation inside the waveguide. A direct application of the effect is a phase shifter, demonstrated experimentally and by numerical simulations. Additionally, an antenna array of two dielectric waveguides, one covered in SWCNTs, is designed and fabricated. The proof-of-concept illustrates optically-controlled beam steering enabled by carbon nanotubes, and directions for further device optimizations are provided. These findings demonstrate thin SWCNT layers as an optically-reconfigurable element, suitable for broadband millimeter-wave communications.

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    fulltext
  • 38.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Morales, Alvaro
    Okonkwo, Chigo
    Tafur Monroy, Idelfonso
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Dielectric Rod Antenna Array for Photonic-Based Sub-Terahertz Beamforming2019In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, IEEE, 2019Conference paper (Refereed)
    Abstract [en]

    This work presents a dielectric rod antenna array designed for a photonic-enabled beamforming system at subterahertz frequencies. The photonic chip generates an optical group delay, providing the beam-steering capability. The antenna array is fabricated from high-resistivity silicon by micromachining. Simulation results demonstrate a directivity of 14.7 dBi and a beam steering range of 56 degrees at 85 GHz. The system is intended as a sub-THz transmitter for broadband wireless communications.

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  • 39.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Przewłoka, Aleksandra
    Institute of High-Pressure Physics PAS.
    Krajewska, Aleksandra
    Institute of High-Pressure Physics PAS.
    Zykov, Dmitry
    ITMO University.
    Demchenko, Petr
    ITMO University.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Khodzitsky, Mikhail
    ITMO University.
    Nefedov, Igor
    Saratov National Research State University.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. CENTERA Laboratories Institute of High-Pressure Physics PAS Warsaw 01-142 Poland.
    Sub‐THz Phase Shifters Enabled by Photoconductive Single‐Walled Carbon Nanotube Layers2022In: Advanced Photonics Research, ISSN 2699-9293, p. 2200042-2200042Article in journal (Refereed)
    Abstract [en]

    Materials with tunable dielectric properties are highly relevant for terahertz (THz) applications. Herein, the tuning of the dielectric response of single-walled carbon nanotube layers by light illumination is studied for applications to THz phase shifters. The dependence of the length of individual nanotubes on the THz photoconductivity of the network is experimentally investigated in the frequency range of 0.2–1 THz by time-domain spectroscopy (TDS). The effective conductivity of the networks is described by a theoretical model that fits the measured dielectric function. Terahertz phase shifters are realized with the carbon nanotube layers as the optically tunable element deposited on the wall of rectangular dielectric waveguides. The phase of the electromagnetic wave propagating in the waveguide is shown to be tunable by illuminating the nanotubes. A linear phase shift with the frequency is measured between 75 and 500 GHz with a low change in amplitude due to the illumination.

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  • 40.
    Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Xenidis, Nikolaos
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Institute of High Pressure Physics PAS, CENTERA Laboratories, Poland.
    Generation of High-order Modes in Sub-THz Dielectric Waveguides by Misalignment of the Transition Structure2022In: 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022, Institute of Electrical and Electronics Engineers (IEEE), 2022, p. 479-482Conference paper (Refereed)
    Abstract [en]

    Dielectric waveguides are a potential platform for future integrated THz electronics but are still challenging to interface with standard measurement equipment. The commonly used tapered transition to hollow metallic waveguides involves manual alignment, leading to measurement inaccuracies. In this paper, we report the effects of misalignment between a dielectric and a metallic waveguide in the W-band. The results indicate the excitation of unwanted high-order modes in the dielectric waveguide that are expected to degrade the performance, especially at higher frequencies.

  • 41.
    Xenidis, Nikolaos
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Przewłoka, Aleksandra
    Stelmaszczyk, Kamil
    Haras, Maciej
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Krajewska, Aleksandra
    Ivanov, Roman
    Hussainova, Irina
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Skotnicki, Tomas
    Mierczyk, Zygmunt
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Dichroic absorption of aligned graphene-augmented inorganic nanofibers in the terahertz regime2024In: Applied Materials Today, E-ISSN 2352-9407, Vol. 39, article id 102245Article in journal (Refereed)
    Abstract [en]

    This article investigates the dichroic properties of aligned γ-Al2O3 nanofibers coated with graphene in the terahertz (THz) regime, revealing significant variance in absorption based on the orientation of the electric field in relation to the nanofibers, arising from the anisotropic nature of the material. Samples are prepared in a hot-wall chemical vapor deposition reactor with varying growth times, resulting in 5 samples with increasing graphene content. Compositional characterization is carried out using scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The samples are characterized electromagnetically using two distinct measurement techniques. First, a novel waveguide measurement setup is deployed, wherein square waveguide cassettes are used to capture the anisotropic behavior of the material and equally measure both polarization states in 67–500 GHz. Then, the samples are characterized using terahertz time-domain spectroscopy up to 4 THz. Both techniques highlight absorption enhancement when the electric field is parallel to the fibers, opening new possibilities for THz devices using polarization filtering.

  • 42.
    Xenidis, Nikolaos
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Smirnov, Serguei
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Przewloka, Aleksandra
    Institute of High Pressure Physics, CENTERA Laboratories, Poland.
    Krajewska, Aleksandra
    Institute of High Pressure Physics, CENTERA Laboratories, Poland.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. Institute of High Pressure Physics, CENTERA Laboratories, Poland.
    Waveguide Measurements of Highly Anisotropic Graphene Augmented Inorganic Nanofibers2023In: 2023 53rd European Microwave Conference, EuMC 2023, Institute of Electrical and Electronics Engineers (IEEE) , 2023, p. 576-579Conference paper (Refereed)
    Abstract [en]

    This work presents the preparation and the frequency domain measurements of graphene augmented inorganic nanofibers oriented across the longitudinal axis of the fibers, embedded in a hollow WR-10 waveguide cassette. A simple measurement setup is employed, allowing for rapid, broadband characterization of the material under test. Due to the orientation of the fibers, highly anisotropic behavior is revealed.

1 - 42 of 42
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