Department of Optoelectronics

Head of department prof. Gintaras Valušis
phone +370 5 2649211

Department is active in both fundamental and applied research in the fields of semiconducting materials physics and technology, optoelectronic device technology and applications. Modern epitaxial growth equipment available at the Department allows us to produce semiconductor structures from novel materials such as group III bismides, and fabricate from these structures optoelectronic components for infrared and terahertz spectral ranges. Researchers of the Department have complex experimental facilities for optical characterization of different materials; they have developed numerous unique terahertz spectroscopy and imaging techniques.


Laboratory of Ultrafast optoelectronics

  • Tunable wavelength femtosecond duration pulsed optical parametric generator (ORPHEUS, Light Conversion);
  • Ti:sapphire femtosecond laser (MIRA, Coherent);
  • Ti:sapphire femtosecond laser (Femtolaser);
  • Yb:KGW femtosecond laser oscillator (Light Conversion);
  • Er:fiber femtosecond laser (Toptica);
  • THz time-domain spectroscopy system;
  • Optical pump – THz probe system.
Optoelectronic Technology Laboratory  
  • Veeco GENxplor molecular beam epitaxy system is designed for the epitaxial growth of high quality III-V semiconductor compounds with very high deposition control accuracy on substrates up to 3’’ in diameter. The system is equipped with In, Ga, Al, Bi metallic sources, As, Sb crackers and Si, Be and Te for doping.
  • SVT “III-V MBE System Model C-V-2“  for the growth of III-V semiconducting layers and quantum structures. The device is equipped with In, Ga, Al, Bi metallic sources, As bulk and cracker and Si and Be for doping.
  • Integrated Vacuum Deposition System Model TFDS- 870 – intended for metal contacts deposition. Presently is possible to deposit Au, Ge, Ti, Ni, Al, AuGe one or multilayer contacts.
Semiconductor Optics Laboratory  
  • Modulation spectroscopy setup (photo- and electroreflectance, SPV, l‑modulation; spectral range  0.5 – 4 eV).
  • Low-temperature optical spectroscopy setup (photo- and electroreflectance, PL, PLE, l‑modulation; spectral range 0.56 – 5 eV, temperature range 4 – 300 K).
  • Spectroscopic ellipsometry setup (RC2 Woolam and RAE ellipsometers; spectral range 0.4 – 6.2 eV).
  • Setup of polarization modulation and magnetooptics (PEM, B ~ 3 T).
  • FTIR spectroscopy setup (Vertex 70v FT, spectral range 0.01 – 0.7 eV).
  • Light scattering setup  (1.5 – 4 eV).
  • Shimadzu UV-3600 spectrophotometer with integrating sphere.
Terahertz photonics laboratory  
  • Edinburgh Instruments THz laser FIRL-100;
  • VDI frequency multiplier chains for 100/200/300/600 GHz;
  • Thermo Scientific Fourier transform infrared spectrometer Nicolet 8700;
  • Custom‐designed vacuum Fourier transform infrared spectrometer;
  • Toptica Terascan 780 system;
  • Custom‐designed Spectroscopic THz imaging system;
  • Janis Research closed cycle LHe cryostat with optical windows and electrical connectors;
  • Custom‐designed LN2 cryostat with optical windows and electrical connectors;
  • Probes station and laboratory equipment for I/V and C/V measurements under low- and high-voltage bias in dc-, ac-, and pulse regime.
  • European Space Agency (ESA) project „Bismides for InfraRed photoDetector applications“(BIRD)
    The project is focused on the development of technology of novel semiconductor compounds – dilute bismides. Strong influence of Bi atoms incorporated into various A3B5 (GaAs, GaInAs, and InAs) semiconductors on their electronic band structure enables growth of bismides on different substrates materials (GaAs, InP, and GaSb) with much narrower bandgaps photosensitive at near- and mid-infrared wavelengths. The main objectives of the project are to verify the suitability of optimized bulk bismide layers technologies for two applications: i) as a materials with ~1 eV energy bandgap for highly efficient multijunction (3J or 4J) photovoltaic solar cells, and ii) as substrates for photodiodes and focal-plane-arrays sensitive at infrared wavelengths up to 4 mm.
    Project duration 2016 01 18-2018 01 17
    The Prime Contractor is State Research Institute Center for Physical Sciences and Technology (FTMC)
    The project budget is 199 135 EURo

  • FP7 Marie Curie ITN project NOTEDEV (Novel terahertz devices)
    NOTEDEV (Novel Type of Terahertz Devices) is a Marie Curie Initial Training Network that aims to tackle the terahertz gap. A consortium of leading European Universities and industrial partners are collaborating to conduct research and to train young physicists and device engineers in this field. Terahertz sources and detectors have powerful potential for applications in biology, medicine, security and non-destructive testing. Some devices are currently in operation, but to benefit from the full potential of Terahertz frequencies there is an urgent need for developments in efficient, cheap, reliable, scalable and portable THz devices. In the Center for Physical Sciences and Technology, development of semiconducting THz components for Time-Domain Spectroscopy (TDS) systems activated by 1.55 μm femtosecond (fs) laser pulses is in progress.  These fs lasers would ensure a cost-effective and compact THz-TDS system.
    Project duration 2014 10 01-2017 09 30
    The Prime Contractor is Durham university, FTMC group leader is A. Krotkus
    The project budget is 185 000 EUR

  • Nonpolar ZnO thin films: Growth-related structural and optical properties (Mutual Funds Taiwan – Latvia – Lithuania, 2014-2016)
  • Project LAT-04/2016 (3500-P330) „Compact integrated THz components and spectroscopic THz imaging systems – KITKAS“, LAT-04/2016 (Research Council of Lithuania, 2016-2018). Coordinator – Irmantas Kašalynas

  • Project MIP-71/2015 „Bismuth quantum dots in GaAs matrix – BiNano“, (Research Council of Lithuania, 2015-2017).  Coordinator – Renata Butkutė (Dalius Seliuta)

  • Project MIP-14281 „Active metamaterial investigation and application for terahertz switching and modulation“ (Research Council of Lithuania, 2014 – 2017) Coordinator – Žilvinas Kancleris (Dalius Seliuta). 

Most important publications
  1. Sandra Stanionytė, Vaidas Pačebutas, Bronislovas Čechavičius, Andrius Bičiūnas, Andrejus Geižutis, Virginijus Bukauskas, Renata Butkutė, Arūnas Krotkus. Impact of thermal treatments on epitaxial GayIn1−yAs1−xBi x layers luminescent properties. Journal of materials science. ISSN 0022-2461. 2018, vol. 53, iss. 11, p. 8339-8346.
  2. Vytautas Janonis, Vytautas Jakštas, Irmantas Kašalynas, Pawel Prystawko, Piotr Kruszewski. Reflectivity of plasmon–phonon modes in grating coupled AlGaN/GaN heterostructures grown on SiC and GaN substrates. Physica status solidi. B, Basic solid state physics. ISSN 0370- 1972. 2018, vol. 255, iss. 5, art. no. 1700498, p. 1-6.
  3. Ignas Grigelionis, Vytautas Jakštas, Vytautas Janonis, Irmantas Kašalynas, Pawel Prystawko, Piotr Kruszewski, Michal Leszczynski. Terahertz electroluminescence of shallow impurities in AlGaN/GaN heterostructures at temperatures above 80 K. Physica status solidi. B, Basic solid state physics. ISSN 0370-1972. 2018, vol. 255, iss. 5, art. no. 1700421, p. 1-5.
  4. Domas Jokubauskis, Linas Minkevičius, Mindaugas Karaliūnas, Simonas Indrišiūnas, Irmantas Kašalynas, Gediminas Račiukaitis, Gintaras Valušis. Fibonacci terahertz imaging by silicon diffractive optics. Optics letters. ISSN 0146-9592. 2018, vol. 43, iss.12, p. 2795-2798.
  5. Anders Elfwing, Ponseca Jr., Carlito S., Ouyang Liangqi, Andžej Urbanovič, Arūnas Krotkus, Tu Deyu, Forchheimer Robert, Inganäs Olle. Conducting helical structures from celery decorated with a metallic conjugated polymer give resonances in the terahertz range. Advanced functional materials. ISSN 1616-301X. 2018, vol. 28, iss. 24, art. no 1706595, p. 1-8.
  6. Milda Tamošiūnaitė, Simonas Indrišiūnas, Vincas Tamošiūnas, Linas Minkevičius, Andžej Urbanovič, Gediminas Račiukaitis, Irmantas Kašalynas, Gintaras Valušis. Focusing of terahertz radiation with laser-ablated antireflective structures. IEEE transactions on terahertz science and technology. ISSN 2156-342X. 2018, vol. 8, iss. 5, p. 541-548.
  7. Vaidas Pačebutas, Sandra Stanionytė, Andrius Arlauskas, Ričardas Norkus, Renata Butkutė, Andrejus Geižutis, Bronislovas Čechavičius, Arūnas Krotkus. Terahertz excitation spectra of GaAsBi alloys. Journal of physics D: Applied physics. ISSN 0022-3727. 2018, vol. 51, iss. 47, art. no. 474001, p. 1-7.
  8. Vilius Palenskis, Linas Minkevičius, Jonas Matukas, Domas Jokubauskis, Sandra Pralgauskaitė, Dalius Seliuta, Bronislovas Čechavičius, Renata Butkutė, Gintaras Valušis. InGaAs diodes for terahertz sensing-effect of molecular beam epitaxy growth conditions. Sensors. ISSN 1424-8220. 2018, vol. 18, iss. 11, art. no. 3760, p. 1-13.
  9. Uroš Puc, Abina Andreja, Anton Jeglič, Aleksander Zidanšek, Irmantas Kašalynas, Rimvydas Venckevičius, Gintaras Valušis. Spectroscopic analysis of melatonin in the terahertz frequency range. Sensors. ISSN 1424-8220. 2018, vol. 18, iss. 12, art. no. 4098, p. 1-12.
  10. Kęstutis Ikamas, Ignas Nevinskas, Arūnas Krotkus, Alvydas Lisauskas. Silicon field effect transistor as the nonlinear detector for terahertz autocorellators. Sensors. ISSN 1424-8220. 2018, vol. 18, iss. 11, art. no. 3735, p. 1-11.
  11. Ričardas Norkus, Andrius Arlauskas, Arūnas Krotkus. Terahertz excitation spectra of InP single crystals. Semiconductor science and technology. ISSN 0268-1242. 2018, vol. 33, iss. 7, art. no. 075010, p. 1-5.
  12. Vytautas Karpus, Ričardas Norkus, Renata Butkutė, Sandra Stanionytė, Bronislovas Čechavičius, Arūnas Krotkus. THz-excitation spectroscopy technique for band-offset determination. Optics express. ISSN 1094-4087. 2018, vol. 26, no. 26, p. 33807-33817.
  13. Mindaugas Karaliūnas, Kinan E. Nasser, Andžej Urbanovič, Irmantas Kašalynas, Dalia Bražinskienė, Svajus Asadauskas, Gintaras Valušis. Non-destructive inspection of food and technical oils by terahertz spectroscopy. Scientific reports. eISSN 2045-2322. 2018, vol. 8, art. no. 18025, p. 1-11.
  14. Karolis Ratautas, Mindaugas Andrulevičius, Aldona Jagminienė, Ina Stankevičienė, Eugenijus Norkus, Gediminas Račiukaitis. Laser-assisted selective copper deposition on commercial PA6 by catalytic electroless plating – process and activation mechanism. Applied surface science. ISSN 0169-4332. 2019, vol. 470, p. 405-410.
  15. Dalius Seliuta, Gediminas Šlekas, Gintaras Valušis, Žilvinas Andrius Kancleris. Fano resonance arising due to direct interaction of plasmonic and lattice modes in a mirrored array of split ring resonators. Optics letters. ISSN 0146-9592. 2019, vol. 44, iss. 4, p. 759-762.
  16. Ignas Grigelionis, Justinas Jorudas, Vytautas Jakštas, Vytautas Janonis, Irmantas Kašalynas, Pawel Prystawko, Piotr Kruszewski, Michal Leszczyński. Terahertz electroluminescence of shallow impurities in AlGaN/GaN heterostructures at 20 K and 110 K temperature. Materials science in semiconductor processing. ISSN 1369-8001. 2019, vol. 93, p. 280-283.
  17. Alesia Paddubskaya, Marina Demidenko, Konstantin Batrakov, Gintaras Valušis, Tommi Sakari Kaplas, Yuri Svirko, Polina Kuzhir. Tunable perfect THz absorber based on a stretchable ultrathin carbon-polymer bilayer. Materials. ISSN 1996-1944. 2019, vol. 12, iss. 1, art. no. 143, p. 1-11.
  18. Domas Jokubauskis, Linas Minkevičius, Dalius Seliuta, Irmantas Kašalynas, Gintaras Valušis. Terahertz homodyne spectroscopic imaging of concealed low-absorbing objects. Optical engineering. ISSN 0091-3286. 2019, vol. 58, iss. 2, art. no. 023104, p. 1-4.
  19. Roman Viter, Maryna Savchuk, Nickolay Starodub, Zigmas Balevičius, Saulius Tumėnas, Almira Ramanavičienė, Daniels Jevdokimovs, Donats Erts, Igor Iatsunskyi, Arūnas Ramanavičius. Photoluminescence immunosensor based on bovine leukemia virus proteins immobilized on the ZnO nanorods. Sensors and actuators B: Chemical. ISSN 0925-4005. 2019, vol. 285, p. 601-606.
  20. Justinas Glemža, Vilius Palenskis, Andrejus Geižutis, Bronislovas Čechavičius, Renata Butkutė, Sandra Pralgauskaitė, Jonas Matukas. Low-frequency noise investigation of 1.09 μm GaAsBi laser diodes. Materials. ISSN 1996-1944. 2019, vol. 12, iss. 4, art. no. 673, p. 1-13.
  21. Simonas Indrišiūnas, Heiko Richter, Ignas Grigelionis, Vytautas Janonis, Linas Minkevičius, Gintaras Valušis, Gediminas Račiukaitis, Till Hagelschuer, Heinz-Wilhelm Hübers, Irmantas Kašalynas. Laser-processed diffractive lenses for the frequency range of 4.7 THz. Optics letters. ISSN 0146-9592. 2019, vol. 44, no. 5, p. 1210-1213.