My research interests include development of THz sources and applications of THz radiation.
- Optimised hybrid photoconductive antennas for efficient THz generation.
In the past five years numerous attempts to increase the efficiency of PCA by placing nanoscale plasmonic electrodes – metal optical nanoantennas into the gap of the PCA were demonstrated. Such PCAs, combining the photoconductive switch generating the THz radiation with metallic nanoantennas, which increase the absorption efficiency of the optical pump into the semiconductor substrate, are called Hybrid Photoconductive Antennas (HPCA). This approach has eventually reached its limit.
To boost generation efficiency further we propose to use dielectric metasurfaces instead of metal. They better enhance the absorption, yet not affecting the antenna impedance, thus offering better performance.
2. THz Pulse Time-domain Holography.
This method is the powerful technique for high-resolution amplitude and phase THz imaging that allows mapping spectroscopic information across the imaged object. We considered most sought after applications of phase imaging provided by this technique and experimentally demonstrated the ability of the method to reconstruct smooth and stepped relief features of an object that is transparent in THz region. Phase distribution not only reveals the object features qualitatively, but also allows the reconstruction of the object thickness pattern, even in low signal-to-noise registration conditions.
3. Quantum dot based photoconductive antennas.
Quantum Dot based photoconductive antennas have been proposed. The QD substrate allowed significant enhancement of pumping conditions, both in terms of power and wavelength range, and enabled the use of compact semiconductor lasers as pump sources, thus reducing the geometrical size and price for the THz spectroscopic setup. Antennas were shown to operate in both pulsed and CW regimes and to work without breaks under pump powers of up to 1W
4. Ultrafast Optical Pump-THz Probe Spectroscopy.
THz pump-probe measurements allow for free carrier monitoring in photoconductive media and are efficient tool for semiconductor materials evaluation and studying the interband and intraband processes.