PhD thesis supervisor: dr. Vytautas Jukna (apply for recommendation)
Soft terahertz (thz) optical elements based on dynamically reconfigurable structures
In recent years, terahertz (THz) radiation sources have achieved significantly higher stability, power, spectral and spatial coherence, enabling rapid expansion of their applications from materials research and biological structure diagnostics to imaging systems and short-range communication technologies. However, THz optical elements remain predominantly static, limiting the achievable degree of beam control and restricting system flexibility.
This project aims to investigate soft and dynamically reconfigurable materials for the development of actively tunable THz optical elements. By inducing resonant volume or surface oscillations in such soft media, it is expected to create controllable static and dynamic refractive index profiles that modify the optical path and, for example, enable THz beam focusing, diffraction-order generation via tunable gratings, or other forms of spatial beam modulation. Continuous or discrete adjustments of oscillation frequency or amplitude would allow real‑time control of focal length or diffraction period, providing exceptional functional versatility. A simple illustrative example is the parabolic surface formed by a rotating liquid, acting as a lens; more complex structures may be obtained using density‑stratified liquids or ferromagnetic fluids whose distribution is controlled by magnetic fields.
Such a platform based on dynamically reconfigurable soft materials could unlock new possibilities for flexible THz optics and substantially broaden the landscape of THz photonics applications.