The terahertz (THz) part of the electromagnetic (EM) spectrum is attractive for a number of diverse applications: it promises large channel capacity for short-range wireless communication; enhanced sensitivity in air pollution monitoring and unique capabilities in imaging.

Efficient generation and sensitive detection of THz waves remains one of the main challenges limiting future applications in this part of the EM spectrum. Special opto-electronic techniques have recently been developed to detect THz waves. Among them is the opto-electronic sampling, in which photoconductive THz antennas are used. The THz antenna is combined with a photoconductive switch, which changes its resistivity when it is gated by a short optical pulse. This produces a photocurrent proportional to the amplitude of the THz wave.

In one Project, a compact dedicated transimpedance amplifier will be designed, build and tested with a THz photoconductive antenna. The goal is to develop a compact low-noise detector for opto-electronic sampling of THz signals. Performance of the THz detection system will be compared to commercial general purpose amplifier systems.

In another Project, the semiconductor active region will be designed to incorporate photonic and plasmonic nano-structures in order to enhance the sensitivity of the photo-conductive THz detector.

Terahertz (THz) photonics systems, systems that use THz electromagnetic waves (0.1-10THz), typically rely on free-space THz beam propagation due to the lack of commercial THz waveguides. Waveguides however cam make THz systems compact and adjustable to desired applications and therefore transform THz systems in the same way silica fibre transformed optical systems. In this project hollow-core THz waveguides will be investigated for transmission of THz waves.

The project will address propagation of broad-band THz signals in multimode waveguides. It will involve numerical and analytical modelling of the THz waveguides and signal deformation in waveguides. The goal is to evaluate performance of the most promising THz waveguides for signal transmission applications.

Terahertz (THz) near-field microscopy

Terahertz waveguides

Organic electronics and two-photon excitation photo-luminescence spectroscopy