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
