Date of Award

2025

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Applied Physics (PhD)

Administrative Home Department

Department of Physics

Advisor 1

Jae Yong Suh

Committee Member 1

Miguel Levy

Committee Member 2

Durdu Guney

Committee Member 3

Ramy El-Ganainy

Abstract

This work presents different ways to engineer light-matter interactions by using nanostructures to exploit quantum-optical phenomena. First, sodium (Na) is predicted to be an ideal plasmonic material due to its ultra-low optical losses from the visible to the near-infrared (NIR). However, Na has practical limitations due to its high chemical reactivity. Using a scalable fabrication method for Na plasmonic nanostructures by combining phase-shift photolithography and a thermo-assisted spin-coating process, we produced nano-pit arrays of varying periodicities (300-600 nm), supporting tunable surface plasmon polariton (SPP) modes spanning visible to NIR. These structures demonstrated SPP resonances as narrow as 9.3 nm, with linewidth narrowing towards the NIR, highlighting their potential for low-loss NIR plasmonic applications. An encapsulation strategy was employed successfully, stabilizing the Na structures in ambient conditions for over two months. Continuing to explore the alkali metal library, we extended this approach to potassium (K) and sodium-potassium (NaK) liquid alloys, introducing a thermo-assisted nanoscale embossing (TANE) fabrication technique. This enabled the fabrication of high-quality plasmonic nanostructures with resonances as narrow as 15 nm in the NIR. Exploiting the Na-K eutectic phase diagram, we further expanded possibilities in liquid NaK plasmonics, enabling new platforms for active metamaterials and advanced photonic devices. Finally, quasi-two-dimensional (2D) perovskites with superlattice structures were investigated as platforms for room-temperature superfluorescence. Using steady-state and time-resolved spectroscopy, we identified characteristic signatures of superfluorescence– narrow emission linewidth, quadratic emission dependence on excitation power, and a delayed emission burst. These properties were unique to quasi-2D perovskites and absent in its 3D bulk form. Scanning transmission electron microscopy (STEM) confirmed superlattice formation, suggesting its presence is essential for superfluorescence. These results indicate that the search for new superfluorescent materials should prioritize exploring analogous materials with well-defined superlattice structures.

Creative Commons License

Creative Commons Attribution-Share Alike 4.0 License
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.

Available for download on Tuesday, October 14, 2025

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