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SUMMARY:Tunable CNT Surfaces for THz Wave Applications
DTSTART;VALUE=DATE-TIME:20220706T153500Z
DTEND;VALUE=DATE-TIME:20220706T155000Z
DTSTAMP;VALUE=DATE-TIME:20260815T164135Z
UID:indico-contribution-777@events.ncbj.gov.pl
DESCRIPTION:Speakers: Aleksandra Przewłoka (CENTERA Laboratories\, Instit
 ute of High Pressure Physics\, PAS )\, Dmitri Lioubtchenko (CENTERA Labora
 tories\, Institute of High Pressure Physics\, PAS )\nThe research and deve
 lopment in the frequency region of 0.1-1.0 THz is extremely significant fo
 r the wide range of applications\, such as telecommunication and imaging s
 ystems\, material spectroscopy\, medical imaging and treatments\, etc. Des
 pite the problems in technology and high prices for basic components (phas
 e shifters\, directional couplers\, etc.)\, the THz systems offer higher d
 ate rates for telecommunication\, high spatial resolution in the visualiza
 tion of objects\, small size of antennas and other elements. The state-of-
 the-art of the THz devices reveals serious problems with radiation sources
  with continuous wave semiconductor-based source\, electronically tunable 
 phase shifters\, etc.\nCarbon nanotubes (CNT) offer unique properties due 
 to their natural small dimensions and outstanding electrical properties. T
 heir tunability properties makes them very attractive in application to th
 e THz system. Integration of CNTs with the dielectric rod waveguide (DRW) 
 technology transferred from cellulose membranes onto other substrates (sap
 phire DRW\, optical glass\, polished silicon) by direct dry transfer enabl
 es a novel technology platform for tunable THz systems.\nPhase shifter can
  be developed by introducing the optically controlled varactor to the DRW.
  The phase change of 10-20 deg with almost negligible change in attenuatio
 n less than 0.1 dB can be achieved in the frequency range of 75-500 GHz. B
 esides\, DRWs have no cut-off frequency enabling broad band operation.\nTh
 e effect of the dielectric constant tuning of single-walled carbon nanotub
 es under light illumination is observed in the very wide frequency range o
 f 0.1–1 THz. The optical absorption spectrum is not uniform and it consi
 sts of several absorption peaks related to electron transitions. Therefore
 \, the change of capacity and resistance under different light wavelength 
 illumination is different at different wavelengths.\nThe losses are attrib
 uted to the electromagnetic absorption by the CNT layers with differences 
 stemming from variations in nanotube densities and total lengths of the tr
 ansferred samples on the DRWs. The increased absorbance at lower frequenci
 es has also been previously observed for CNTs.\nCarbon based nanomaterials
  are perspective materials for very wide applications in millimeter wave a
 nd THz frequency range. Phase shifter based on DRW loaded with CNT layer i
 s a perspective candidate for ultra-wide band device application. The ultr
 a-wide band optically controlled CNT-based phase shifter can enable THz be
 am steering.\n\nhttps://events.ncbj.gov.pl/event/75/contributions/777/
LOCATION:Novotel Warszawa Centrum Róża
URL:https://events.ncbj.gov.pl/event/75/contributions/777/
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