Hybridization of open photonic resonators

The control of the interaction between light and matter is of paramount importance in many modern technologies, with applications ranging from sensing to telecommunication and quantum information. Nanophotonic resonators allow to enhance this interaction by the storage and confinement of the light field.
This thesis studies the hybridization of eigenmodes of nano- and microresonators, and in particular the properties of hybrid resonators composed of a dielectric cavity and plasmonic nanoantennas. Due to their lossy nature, in particular radiation, photonic resonators can only be well described in the framework of quasinormal modes theory (QNM). We confirm the relevance of such theories by investigating the physics of the perturbation of high-Q dielectric cavities aided by numerical and experimental works. Then we propose a theory to study the hybridization of multiple resonators and predict the properties of the ensemble. In the context of antenna-cavity hybrids, previous works have demonstrated the great potential of such resonators to enhance light-matter interaction further than what is achieved with their components taken individually. Here we show, with theoretical and experimental works that such resonators also offer additional degrees of control over the properties of the emitted light, such as directionality or beams carrying a pure orbital angular momentum. We furthermore investigate the performances of such hybrid resonators in the context of molecular optomechanics. Indeed, we show they can be an excellent platform to enhance Raman scattering, while simultaneously offering input and output channels with controllable properties for the pump and Raman signals.