Physics and Applications of Exceptional Surfaces
Open Access
- Author:
- Soleymani, Sina
- Graduate Program:
- Engineering Science and Mechanics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- November 16, 2021
- Committee Members:
- Melik Demirel, Major Field Member
Sahin Ozdemir, Chair & Dissertation Advisor
Parisa Shokouhi, Outside Field Member
Shengxi Huang, Outside Unit Member
Albert Segall, Program Head/Chair - Keywords:
- Exceptional Surfaces
Exceptional Points
Non-Hermitian Optics
Parity-Time symmetric Photonics - Abstract:
- In this dissertation, I present my theoretical and experimental research about exceptional points, its applications in optics, and the experimental realization of the exceptional surface concept. Whispering gallery mode microresonators which are the platform of our study is briefly discussed, and their characterization methods are presented. Non-Hermitian photonics and related phenomena and the background are discussed briefly. The exotic features of non-Hermitian physics and the spectral degeneracies known as exceptional points are explained and the design of a resonator-based photonic system which allows tuning the system controllably to and from EPs is demonstrated via creating non-Hermiticity via unidirectional coupling between two optical modes of the resonator. We have demonstrated, for the first time, chiral and degenerate perfect absorption on exceptional surfaces and studied thermal behavior of WGM microresonators on the exceptional surfaces. In addition to exceptional surfaces and chiral perfect absorption, we investigated theoretically optical forces in non-Hermitian systems, in particular in a parity-time symmetric coupled waveguide system. First, we utilized generalized Wigner-Smith operator and eigenmode optimization methods to maximize optical forces on a nanoparticle in a Hermitian coupled waveguide system confirming that these two methods give similar results. Since Wigner-Smith operator method is not applicable in non-Hermitian settings, we use eigenmode optimization method in PT-symmetric coupled waveguides system to demonstrate optimal forces and their control. I have also contributed to the theoretical efforts of two collaborative studies. In the first one, we have studied optomechanical coupling in a microbottle resonator to achieve high mechanical frequency and quality factors for room temperature quantum optomechanics. In the second one, we studied exceptional points in the tunable collective light-matter interactions in a system of a Terahertz cavity field coupled to molecular vibrations.