Abstract

Precise control over light polarization is critical for advancing technologies in telecommunica- tions, quantum computing, and image sensing. However, existing methods for manipulating polarization around exceptional points in non-Hermitian systems, have exclusively focused on circular polarization and work with reflected light. To address this limitation, we de- velop a novel metasurface platform with high-Q resonators that enables tunable control of polarization exceptional points across arbitrary ellipticity for transmitted light. Our design uses orthogonally polarized guided mode resonators in a two-layer silicon metasurface, where careful tuning of the dipolar guided mode resonances (DGMRs) and layer spacing allows us to control the ellipticity of exceptional points. Leveraging high-quality factor resonances, we achieve strong orthogonal mode coupling over distances up to a quarter wavelength. This platform exhibits omnipolarizer behavior and the corresponding phase singularity can im- print phase shifts from 0 to 2π with small perturbations in the geometry. We then leverage the phase singularity to create a diffraction grating by creating a periodic metasurface that staggers two meta-atoms with a relative transmitted phase of π. This approach opens new possibilities for polarization control and programmable wavefront shaping, offering significant potential for next-generation optical devices.

Committee Chair

Mark Lawrence

Committee Members

Janet Sorrells, Lan Yang

Degree

Master of Science (MS)

Author's Department

Electrical & Systems Engineering

Author's School

McKelvey School of Engineering

Document Type

Thesis

Date of Award

Fall 12-2024

Language

English (en)

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