Terahertz spectroscopy is a very sensitive non-contact technique that can be used for a broad range of applications to investigate the intermolecular hydrogen-bonding vibrations, crystalline structure lattice vibrations or low-frequency internal vibrations. Our research group is using the Terahertz time domain spectroscopy (THz-TDS) technology that allows to measure the time-dependent electric field, recording the THz pulse intensity and its phase.
This laboratory has a TPS Spectra 3000 Terahertz (THz) spectrometer with modular sample compartment for transmission, ATR analysis, XY Mapping and reflectance imaging (RIM). It is working at frequencies ranging between 0.06 and 4 THz (corresponding to 2 to 133 cm-1), with a maximum spectral resolution of 7.5 GHz (0.25 cm-1). Using these modules, the transmittance and reflectance signals can be obtained for different type of samples, solids, liquids, suspensions, slurries and thin films. If the thickness of the sample it is known, absorption coefficients, refractive index, dielectric constant (real and imaginary parts) can be also determined to investigate and monitories changes within the studied samples in real time.
The main applications rely on the study of micro-, macro- and nanostructured materials having special dielectric properties (e.g. ferroelectric materials); real time investigations on material dielectric properties with changing the environment conditions; non - invasive material integrity 3D imaging such as surfaces and compositions of different optical active and passive components; detection of cracks and defects in materials surface and depth: ceramics, solar cells materials/systems, thin films; biomedical imaging.
Relevant publications:
- Kelly, J., N. Kljun, P.-O. Olsson, L. Mihai, B. Liljeblad, P. Weslien, L. Klemedtsson, L. Eklundh. "Challenges and best practices for deriving temperature data from an uncalibrated UAV thermal infrared camera." Remote Sensing 11, no. 5 (2019): 567. https://doi.org/10.3390/rs11050567
- 2. Čermák, J., Mihai L., Sporea D., Galagan Y., Fait J., Artemenko A., Štenclová P., Rezek B., Straticiuc M., Burducea I. "Proton irradiation induced changes in glass and polyethylene terephthalate substrates for photovoltaic solar cells." Solar Energy Materials and Solar Cells 186 (2018): 284-290. https://doi.org/10.1016/j.solmat.2018.06.046
- 3. Sporea, D., Mihai L., Sporea A., Vâţã I. "Optical and THz investigations of mid-IR materials exposed to alpha particle irradiation." Scientific reports 7, no. 1 (2017): 1-7. https://doi.org/10.1038/srep40209
In collaboration with:
- ”Horia Hulubei” National Institute of Physics and Nuclear Engineering, Romania.
- National Institute for R and D in Microtechnologies – IMT, Romania.
- Faculty of Physics, University of Bucharest, Romania.
- Tampere University of Technology, Finland.
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
- Holst Centre – Solliance, Eindhoven, Netherlands.
- School of Electrical Engineering and Computer Science Department of Physics, Max Planck Centre for Extreme and Quantum Photonics University of Ottawa, Canada.