Department of Optoelectronics, Center for Physical Sciences and Technology (FTMC)
PhD These under the title “Optical and Electrical Investigation of GaN-based HEMT and Graphene Structures for Applications in THz Detection” was successfully defended by Justinas Jorudas. The PhD thesis is highlighted with 28 scientific papers and conference proceedings according to Web of Science. Congratulations to dr. Justinas Jorudas and academic supervisor dr. Irmantas Kašalynas with outstanding achievement.
The new research paper by Justinas Jorudas et al. just recently was published in the journal Nanotechnology by IOP Publishing. The study reports on one of the first successful attempts to layer down the nm-scale-thick graphitic film on the wide-spectral-range transparent membrane. The results are promising in the field of development of broadband barometric radiation detectors.
The work is a result of fruitful collaboration between researchers in Center of Photonics Research, University of Eastern Finland, University of Pisa and Istitutute Nanoscienze in Italy and THz Photonics Laboratory at Center for Physical Sciences and Technology in Lithuania.
Full free access paper is available here.
This week we celebrate the issue of Laser & Photonics Review with a cover decorated with our graphical abstract from the article by Sergejus Orlov, Rusnė Ivaškevičiūtė-Povilauskienė et al. This promoted review paper is available as free access publication through the link: https://doi.org/10.1002/lpor.202470028
Išsamus ir įkvepiantis pokalbis su mūsų terahercų fotonikos laboratorijos vyriausiuoju moksliniu darbuotoju, optoelektronikos skyriaus vedėju, ir FTMC direktoriumi akademiku prof. habil. dr. Gintaru Valušiu apie Lietuvos ateities viziją.
“[..] reikalingas bendras supratimas, kad mes visi čia esame labai reikalingi, kad visi galime prisidėti prie proveržio, surasti savo vietą čia ir dabar” – sako Gintaras Valušis.
Interviu galima rasti čia. Interviu paskelbtas lrt.lt žinių portale.
A new research recently published in the scientific journal Food Bioscience includes the THz time-domain spectroscopy results of the bovine bone powder. The optical properties were measured in THz range for adult cows’ femur and tibia bones from the same breed and in the age range from 93 to 120 months. The spectral data were analyzed using principal component analysis and agglomerative hierarchical clustering techniques.
Results of the study showed that the anatomy of the bones was more significant rather than the age. Interestingly, refractive index increased with age of the cattle and was
higher for femur bone if comped to tibia bone.
The work was accomplished in collaboration with Pontificia Universidad Católica de Chile, Millennium Institute for Research in Optics (Chile) and INRAE – Centre Clermont-Auvergne-Rhône-Alpes (France)
The paper can be accessed through this link: 10.1016/j.fbio.2024.103978
We are celebrating exceptional event – Rusnė Ivaškevičiūtė-Povilauskienė PhD thesis defense. She proved herself as a valuable member of our community. Her outstanding work, doctoral thesis Optical Engineering In Terahertz Imaging And 2D Materials Inspections, is well supported with fascinating papers in top scientific journals such as Light: Science and Applications by Nature Publishing Group, Journal of Applied Physics by AIP Publishing, Optical Materials Express by Optica Publishing Group and other. We also congratulate PhD supervisor Gintaras Valušis with this occasion.
We wish best luck to dr. Rusnė Ivaškevičiūtė-Povilauskienė in her future academic career.
This week the lab staff is visiting Montreal, Canada, for 48th International Conference on Infrared , Millimeter, and Terahertz Waves. It is indeed the main event in the field of terahertz research. This year Terahertz Photonics Laboratory contributed 8 talks in various THz research fields.
Here are the list of presentations and the presenting authors:
Nonparaxial Imaging Using Terahertz Structured Light by Gintaras Valušis et al.
Terahertz And DC Conductivity Of Pyrolyzed Photoresist Films by Justinas Jorudas et al.
This Study Explores The Use Of Passive And Flexible Optics Elements To Achieve THz Beam Profile Engineering For Imaging Applications Via Mechanical Bending by Linas Minkevičius et al.
THz Detection Optimization Of Antenna Coupled AlGaN/GaN High Electron Mobility Transistors by Maxim Moscotin et al.
A Design And Performance Of A Low-cost THz Imaging System Using InP Gunn Diode Emitter, Paraffin Wax Optics And Commercially Available GaAs HEMTs by Linas Minkevičius et al.
Coherent Thermal Emission From Circular N-GaN Surface Relief Gratings 100% by Vytautas Janonis et al.
Two- And Four-step Phase Shifting Methods For Terahertz Holography by Rusnė Ivaskevičiūtė-Povilauskienė et al.
Polarization Selective Dual Frequency Metasurface-based Resonant Thermal Terahertz Emitters On N-GaAs/GaAs by Ignas Grigelionis et al.
The link to conference webpage: https://www.irmmw-thz.org/conference/
New open access article is published in the journal Nanomaterials (MDPI) by Vladislovas Čižas, Natalia Alexeeva, Kirill N. Alekseev and Gintaras Valušis. Theoretical study dives into the physical mechanisms of high-frequency gain in a doped semiconductor superlattice
The findings of the research contributes to the advancement of new miniature GHz–THz frequency generators, amplifiers, and dividers operating at room temperature.
The research was partially funded by the Marius Jakulis Jason Foundation and the Research Council of Lithuania (No 01.2.2-LMT-K-718-03-0096).
The paper can be reached through this DOI: . https://doi.org/10.3390/nano13131993
The research article by Roman B. Balagula, Liudvikas Subačius, Paweł Prystawko, and Irmantas Kašalynas is published in Journal of Applied Physics, AIP Publishing. The work entitled “Electro-optical modulation of terahertz beam by drifting space-charge domains in n-GaN epilayers” investigates the transmission modulation of THz field in GaN semiconductor as a response to space-charge domains under near-to-breakdown electrical field conditions.
The open access research article is available through https://doi.org/10.1063/5.0152661
The work was supported by the Research Council of Lithuania through the “Hybrid plasmonic components for THz range (T-HP)” Project (Grant No. DOTSUT-184) funded by the European Regional Development Fund according to the supported activity “Research Projects Implemented by World-class Researcher Groups” under the Measure No. 01.2.2-LMT-K-718-03-0096. The work at Warsaw was supported by the National Center for Research and Development (Grant No. TECHMATSTRATEG-III/0003/2019/EnerGaN).
New work by I. Grigelionis et al. was published in the scientific journal Sensors from MDPI publisher. Authors report on the experimental evidence of thermal terahertz emission tailored by magnetic polariton excitations in entirely GaAs-based structures equipped with metasurfaces. Thermal emission was measured at 390 C temperature in the range from 0.7 THz to 1.3 THz, depending on the size of the square metacells.
The magnetic polariton resonance quality factors obtained at elevated temperatures (Q ~ 3.3 to 5.2) are very similar to those of MIM structures as well as to 2D plasmon resonance quality at cryogenic temperatures.
The open access paper can be reached through https://doi.org/10.3390/s23104600
This research has received funding from the Research Council of Lithuania (LMTLT), agreement No. S-MIP-22-76.