ORCID

0000-0003-2504-1303

Keywords

Topological Photonics, Non-Hermitian systems, Programmable integrated photonics

Abstract

The interplay between non-Hermiticity and topology has emerged as a frontier in photonics, with important implications for quantum optics, lasers, and sensors. While conventional approaches rely on Hermitian band structures, recent theory shows that loss and dissipation can themselves give rise to novel topological phenomena. In this dissertation, we experimentally explore this paradigm using programmable integrated photonic platforms based on coupled silicon ring resonators. We first demonstrate that purely non-Hermitian effects, without any underlying Hermitian topology, can induce topological edge states. Implementing a non-Hermitian Aubry–Andre–Harper model with loss modulation, we observe edge-localized modes in both periodic and quasiperiodic configurations and establish their robustness against disorder. Building on this, we report the first experimental realization of topology generated solely by engineered dissipation, highlighting loss modulation as a practical tool for photonic design. Beyond demonstrating these states, we introduce strategies for their controlled excitation and selection. An incoherence-assisted excitation scheme shows that incoherent light can selectively excite topological modes in a non-Hermitian SSH lattice, removing the need for precise phase control. We also realize a non-Hermitian photonic filter that exploits dissipation to isolate a desired state, creating a dissipation-free subspace that enhances protection and robustness. In parallel, we explore Hamiltonian learning in complex photonic systems. Using supervised machine learning applied to spectral data, we accurately predict onsite losses and resonance shifts, providing a scalable and non-invasive route to system characterization. Finally, we extend our study to next-nearest-neighbor couplings by experimentally realizing an extended SSH model with a phase diagram analogous to the Haldane model, revealing how such couplings modify edge states. Together, these results advance the experimental control of non-Hermitian and topological photonics, opening new pathways toward practical topological devices and deeper exploration of non-Hermitian matter.

Completion Date

2025

Semester

Fall

Committee Chair

Andrea Blanco-Redondo

Degree

Doctor of Philosophy (Ph.D.)

College

College of Optics and Photonics

Department

CREOL, college of optics and photonics

Format

PDF

Identifier

DP0029816

Document Type

Thesis

Campus Location

Orlando (Main) Campus

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