Congratulations to Dr. Rusnė Ivaškevičiūtė-Povilauskienė on defending PhD Thesis

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.

FTMC THz photonics lab at Rusnė Ivaškevičiūtė-Povilauskienė PhD defense: (from left to right) dr. Irmantas Kašalynas, dr. Dalius Seliuta, phd student Surya Revanth , dr. Ignas Grigelionis, dr. Rusnė Ivaškevičiūtė-Povilauskienė, phd student Justinas Jorudas, phd student Vladislovas Čižas, dr. Linas Minkevičius, dr. Vytautas Jakštas, dr. Domas Jokubauskis, and prof. dr. Gintaras Valušis.

IRMMW-THz 2023

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:

Coexistence of Bloch and Parametric Mechanisms of High-Frequency Gain in Doped Superlattices

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: .

Electro-optical modulation of terahertz beam by drifting space-charge domains in n-GaN epilayers

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.

Traces of charge current density j, the electro-optic modulation of THz beam transmission ΔTeo, and the sample specific resistance, Edc/j, found as a ratio between measurements of applied electric field and current density traces.

The open access research article is available through

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).

Narrowband Thermal Terahertz Emission of Ti/Au Metasurface on Homoepitaxial GaAs

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

This research has received funding from the Research Council of Lithuania (LMTLT), agreement No. S-MIP-22-76.

A Review: Semiconductor Characterization by Terahertz Excitation Spectroscopy

A comprehensive review written by Arūnas Krotkus, Ignas Nevinskas and Ričardas Norkus on the terahertz excitation spectroscopy and it’s applications is recently published in the journal “Materials” by MDPI Publisher. The experimental technique known as the THz excitation spectroscopy is used as a contactless method to study the band structure and investigate the ultrafast processes of various technologically important materials. A recent decade of investigations with the THz excitation spectroscopy method is reviewed in this paper.

The review is available as an open access publication through this DOI:

The 2023 terahertz science and technology roadmap

New roadmap for THz science and technology is just published in the Journal of Physics D: Applied Physics by IOP Publishing. Among the number of distinguished authors one can find Gintaras Valušis who have significantly contributed to the publication. Congratulations!

The roadmap is a collection of sections addressing the particular aspects of latest THz technology developments. It is indeed the excellent source to get the insights to the future of THz science.

The publication under open access license can be accessed trough this DOI:

European patent on the method of polymethylmethaacrylate (PMMA) removal from a graphene surface by photoexposure was published by EPO

European Patent Office (EPO) published our patent EP3936476B1 — just before 55th FiDi (National Physicist’s Day)! Green method of PolyMethylMethaAcrylate (PMMA) removal from a Graphene surface by photoexposure was invented by Natalia Alexeeva and Irmantas Kašalynas. Read details about EP3936476 here:

How Lithuanian semiconductor creators impressed colleagues from Taiwan

EN: In the “Curiosity Gene” episode the significance and future of semiconductor technologies in Lithuania in the new light of Taiwan transfer of transistor manufacture secrets to Lithuania is presented. The head of FTMC prof. Gintaras Valušis and senior research fellow dr. Linas Minkevičius talks straight from THz Photonics Lab of FTMC. The episode in Lithuanian language can be accessed through this link to the archives of national broadcaster LRT.

LT: “Smalsumo genas” laidoje pasakojama apie puslaidininkinių technologijų svarbą ir perspektyvas Lietuvoje, Taivanui perleidžiant tranzistorių gamybos paslaptis. Laidoje iš Terahercų fotonikos laboratorijos kalba FTMC direktorius prof. Gintaras Valušis ir mokslininkas dr. Linas Minkevičius. Laidos įrašą kviečiame pažiūrėti paspaudus šią nuorodą į LRT mediateką.

European patent on the method for fabrication of recessed electrical elements (EP3975224) is published by EPO

European Patent Office (EPO) just published the patent for the method for fabrication of recessed electrical elements (EP3975224) by inventors Irmantas Kašalynas (head of our lab), Simonas Indrašiūnas, Pawel Prystawko, and Piotr Kruszewski. Two later inventors are our collaborators from Institute of High Pressure Physics at Polish
Academy of Sciences, Poland. The patent can be accessed here: