VILNIUS TECH Library invites you to follow the published new dissertations. The dissertation „Electrodynamical investigation of the photonic metamaterials“ („Fotoninių metamedžiagų elektrodinaminis tyrimas“) prepared by VILNIUS TECH, Athanasios Ioannidis. The doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2019–2023, Supervisor – Assoc. Prof. Dr Tatjana Gric.
The dissertation was defended at the public meeting of the Dissertation Defence Council of Electrical and Electronic Engineering in the SRA-I Meeting Hall of Vilnius Gediminas Technical University at 10 a.m. on 18 December 2023.
The dissertation investigates the possibilities of applying the Maxwell–Garnett approach for homogenising different types of metamaterial structures, such as conventional nanowires, spiral nanowires, and nanostructured composite cases. The research aims to study the dispersion maps of the surface plasmon polaritons (SPPs) propagating at different interfaces, such as metallic nanowire metamaterial interface and the hollow-core metamaterial interface, nanostructured metamaterial and corrugated metal interface, spiral nanowire metamaterial and air interface, nanocomposite and hypercrystal interface. This dissertation aims to analyse the properties of the dispersion and loss of SPPs at the investigated interfaces, aiming to achieve absorption enhancement, enabling the possible creation of the aircraft coating model, and allowing for the cancellation along with the antenna systems. The dissertation enables to analyse system engineering tools, such as the angle of the spiral, the number of grooves, etc., aiming to conclude the tunability possibilities of the structure’s properties. Relevant dispersion relations are derived by matching the tangential components of the electrical and magnetic fields. It is demonstrated that tuning can be achieved by modifying the parameters of the metamaterial building blocks. Moreover, the tunability of the nanowire metamaterials can be enhanced further by changing either the metamaterial filling ratio or metamaterial cell geometry. Calculated dispersion relations and propagation lengths of plasmon modes in the system are presented. It has been concluded that the frequency range of the surface waves’ existence can be significantly increased by dealing with the nanowire metamaterial interface. The possible application of the proposed tunable structures is in antenna and aircraft noise reduction system design.
Doctoral dissertation readers can search via VILNIUS TECH Virtual Library.