Light-Matter Interactions with Photonic Quasiparticles

Abstract

The interactions of matter with electromagnetic fields underlie very many physical phenomena. The physics of these interactions is greatly simplified by their weakness, enabling us to understand them largely at the lowest order in various parameters (e.g., field strength, atomic size, fine-structure constant). This understanding is challenged by recent experiments coupling light to collective electromagnetic excitations in solids ("photonic quasiparticles"), whose strongly confined electromagnetic fields can interact strongly with matter.

This thesis describes how the rules of light-matter interactions are altered when bound and free electrons interact with photonic quasiparticles, and some applications that result. In the first major part of the thesis, I will develop effects arising from the linear optical properties of these excitations, in perturbative and non-perturbative regimes of QED, which give rise to new schemes for generating entangled photons, for X-ray sources, and even for high-energy particle detectors. The second major part of this thesis develops the new physics arising from the nonlinear optical properties of these photonic quasiparticles, and focuses particularly on the development of new non-perturbative nonlinear dissipation and gain phenomena. As an application, I show how these high-order nonlinearity may enable for the first time the deterministic, steady-state generation of large optical Fock and sub-Poissonian states.