This thesis starts with an introduction to the quantum electrodynamical description of the interaction between light and matter. The role of optical cavities is discussed and the basic properties... Show moreThis thesis starts with an introduction to the quantum electrodynamical description of the interaction between light and matter. The role of optical cavities is discussed and the basic properties of rare-earth ions are reviewed. In Chapter 2 a bare ring resonator that is coupled to a waveguide is studied. Transmission spectra are measured, from which optical properties of the ring resonator and the waveguide are characterized. Chapter 3 addresses two technical issues that are essential for the research presented in this thesis: the implantation of rare-earth ions into the ring resonator and the permanent fiber connections to the waveguides. Chapter 4 is devoted to the research on the enhancement of the spontaneous emission rate in an ytterbium-doped ring resonator in the temperature range of 5.5-295 K as a result of the Purcell effect. Chapter 5 presents the results of measurements performed on an ytterbium-doped ring resonator in a dilution refrigerator in the range of 12 mK-4.7 K. In Chapter 6 collective effects of an ensemble of emitters in a cavity are theoretically studied with different initial states and pure dephasing rates by using the quantum Monte Carlo method. Chapter 7 concludes the thesis and presents an outlook for future work. Show less
The initial goal of this thesis was to demonstrate chaos in an open two-mirror resonator. We have designed a bifocal mirror that forms a resonator with an unstable inner and a stable outer part. To... Show moreThe initial goal of this thesis was to demonstrate chaos in an open two-mirror resonator. We have designed a bifocal mirror that forms a resonator with an unstable inner and a stable outer part. To be able to distinguish phenomena unique for configuration from phenomena also present in conventional resonators, i.e., roughness-induced scattering and aberrations, the performance of a conventional stable resonator is investigated first. Roughness-induced scattering turns out to affect the cavity finesse as well as the average power throughput and produces mode coupling close to frequency-degenerate points. We demonstrate, furthermore, a method to accurately determine aberrations by measuring the Gouy phase of subsequent higher-order modes around frequency-degeneracy. The bifocal mirror is not fabricated by traditional grinding and polishing, but by diamond-machining. The eigenmodes of a resonator with one diamond-machined bifocal mirror turn out to be Laguerre-Gaussian. We demonstrate furthermore, the coupling of two resonators based on transmission spectra and patterns, and report on the ability of the configuration to fulfill the basic requirements to obtain chaos. Show less
