Date of Award

2026

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Electrical Engineering (PhD)

Administrative Home Department

Department of Electrical and Computer Engineering

Advisor 1

Elena Semouchkina

Committee Member 1

Durdu Güney

Committee Member 2

Paul L. Bergstrom

Committee Member 3

Ramy El-Ganainy

Abstract

This work investigates dramatic effects produced by the presence of physical boundaries of finite-size metasurfaces, composed of identical cylindrical dielectric resonators without broken symmetry, on the complexity of their responses, observed at normal plane wave incidence, when constituent particles can support only dipolar Mie resonances. Owing to their periodicity, metasurfaces are conventionally analysed using their unit cells with periodic boundary conditions, so that their “finiteness” remains largely under-studied, even though all practical systems are finite.  We demonstrate the opportunities to excite in these finite structures extra high-quality resonance modes, quite distinct from the resonant modes in infinite structures and explain the reasons for their formation. We explore the formation of different types of high-quality modes in metasurface fragments of different configurations and sizes that allows for providing the guidance for configuring their optimal designs. High-quality resonance modes obtained in finite structures with small footprint can realize various functionalities in sensing, filtering, waveguiding and imaging. Analysis of energy band diagrams allowed for revealing that breaking structure symmetry owing to its finiteness led to coupling of dark guided Bloch modes to bright Mie resonances. The integrated modes resulted in the formation of high-quality bonding-type modes. Energy trapping in bonding modes illustrated by inter-resonator coupling and confirmed by scattering patterns enhanced the quality of hybrid resonance modes. Similarities and differences of the obtained results with the existing theories of high-quality integrated resonances are addressed. Details of the quality factors for different configurations of fragments are highlighted, and possible application of configurations with best high Q modes for refractive index sensing is discussed.

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