Quantum dots (QDs) coupled to optical cavities constitute a scalable, robust, on-chip, semiconductor platform for probing fundamental cavity quantum electrodynamics. Very strong interaction between light and matter can be achieved in this system as a result of the eld localization inside sub-cubic wavelength volumes leading to vacuum Rabi frequencies in the range of 10s of GHz. Such strong light-matter interaction produces an optical nonlinearity that is present even at single-photon level and is tunable at a very fast time-scale. This enables one to go beyond fundamental cavity quantum electrodynamics (CQED) studies and to employ such e ects for building practical information processing devices. My PhD work has focused on both fundamental physics of the coupled QD-nanocavity system, as well as on several proof-of-principle devices for low-power optical information processing based on this platform. We have demonstrated the e ects of photon blockade and photon-induced tunneling, which con rm the quantum nature of the coupled dot-cavity system. Using these e ects and the photon correlation measurements of light transmitted through the dot-cavity system, we identify the rst and second order energy manifolds of the Jaynes-Cummings ladder describing the strong coupling between the quantum dot and the cavity eld, and propose a new way to generate multi-Fock states with high purity. In addition, the interaction of the quantum dot with its semiconductor environment gives rise to novel phenomena unique to a solid state cavity QED system, namely phonon-mediated o -resonant dot-cavity coupling. We have employed this effect to perform cavity-assisted resonant quantum dot spectroscopy, which allows us to resolve frequency features far below the limit of a conventional spectrometer. Finally, the applications of such a coupled dot-cavity system in optical information processing including ultrafast, low power all-optical switching and electro-optic modulation are explored. With the light-matter interactions controlled at the most fundamental level, the nano-photonic devices we implemented on this platform operate at extremely low control powers and could achieve switching speeds potentially exceeding 10 GHz.

High quality factor, small mode volume photonic crystal cavities and single emitter quantum dots are the topic of this dissertation. They are studied as both a combined system with InAs quantum dots grown in the center of a 2D GaAs photonic crystal slab nanocavity as well as individually. The individual studies are concerned with passive 1D silicon photonic crystal nanobeam cavities and deterministic, site-selectively grown arrays of InAs quantum dots. For the combined system, strong light matter coupling in a quantum dot photonic crystal slab nanocavity is discussed. Vacuum Rabi splitting is seen when the interaction strength exceeds the dissipative processes of the coupled system. In order to increase the probability of a spectral matching between cavity modes and quantum dot transitions, a technique for condensing an inert gas onto a sample is used. This can lead to a spectral tuning of up to 4 nm of the cavity mode with minimal change in the cavity quality factor while maintaining cryogenic temperatures down to 4 K. The effect of a large density of quantum dots within a quantum dot photonic crystal slab nanocavity is also addressed. Gain and absorption effects are found to occur, changing the cavity emission linewidth from that of its intrinsic value, as well as lasing with a low number of quantum dots and with high spontaneous emission coupling factors. Additionally, methods for improving the quality factor of GaAs photonic crystal cavities and better understanding different loss mechanisms are discussed. In the individual studies, the site-selective growth of InAs quantum dots on pre-structured GaAs wafers is shown as a promising method for the eventual deterministic fabrication of photonic crystal cavities to single quantum dots. An in-situ annealing step is used to reduce quantum dot density, helping ensure that dots are not grown in unwanted locations. Given silicon's potential for achieving higher quality factors than its GaAs counterpart, a study of 1D passive silicon photonic crystal nanobeam cavities is carried out. Transmission through a coupled microfiber is used to measure quality factors of the cavities and compared with that of a crossed polarized resonant scattering measurement.

Mots-clés de l'auteur: cavity quantum electrodynamics ; nanophotonic ; semiconductor ; quantum dot ; optical cavity ; photonic crystal ; Jaynes-Cummings model ; Purcell effect ; decoherence ; dephasing ; phonon ; optical supermode.

This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.

The physics of strong light-matter coupling has been addressed in different scientific communities over the last three decades. Since the early eighties, atoms coupled to optical and microwave cavities have led to pioneering demonstrations of cavity quantum electrodynamics, Gedanken experiments, and building blocks for quantum information processing, for which the Nobel Prize in Physics was awarded in 2012. In the framework of semiconducting devices, strong coupling has allowed investigations into the physics of Bose gases in solid-state environments, and the latter holds promise for exploiting light-matter interaction at the single-photon level in scalable architectures. More recently, impressive developments in the so-called superconducting circuit QED have opened another fundamental playground to revisit cavity quantum electrodynamics for practical and fundamental purposes. This book aims at developing the necessary interface between these communities, by providing future researchers with a robust conceptual, theoretical and experimental basis on strong light-matter coupling, both in the classical and in the quantum regimes. In addition, the emphasis is on new forefront research topics currently developed around the physics of strong light-matter interaction in the atomic and solid-state scenarios.