PhD thesis supervisor: dr. Dovilė Čibiraitė-Lukenskienė (apply for recommendation)
Investigation of field-effect transistor-based detectors in 2 – 5 THz range aiming for compact terahertz receivers for atmosphere research
With the rapid development of quantum cascade lasers in the field of atmospheric research, there is an increasing demand for smaller and more compact systems. The aim of this study is to develop fast and compact sensors based on field-effect transistors operating in the 2–5 THz range and to investigate their characteristics and optical response. For this purpose, a dedicated measurement setup will be developed.
The experiments will be carried out using an optically pumped molecular terahertz (THz) laser operating in the 0.58–7.3 THz frequency range, a frequency spectrometer, a liquid nitrogen or liquid helium cryostat, and other necessary equipment. During the study, the following sample characteristics will be measured: (i) electrical, (ii) optical, (iii) frequency, and (iv) temperature-dependent properties (T = 80–350 K), in order to understand the operating limits of such sensors.
The measured data will be analyzed using resistive and plasmonic mixing theories, with the goal of improving modeling procedures for the design of high-frequency devices. In addition, the applicability of these detectors for the development of high-frequency receivers will be investigated, with potential use in atmospheric spectroscopy, communication, and imaging systems.