Quantum phenomena can nowadays be engineered to realize fundamentally new applications. This is the field of quantum technology, which holds the promise of revolutionizing computation, communication and metrology. By encoding the information in quantum mechanical systems, it appears to be possible to solve classically intractable problems, achieve absolute security in distant communications and beat the classical limits for precision measurements. Single photons as quantum information carriers play a central role in this field, as they can be easily manipulated and can be used to implement many quantum protocols. A key aspect is the interfacing between photons and matter quantum systems, a fundamental operation both for the generation and the readout of the photons. This has been driving a lot of research toward the realization of efficient atom-cavity systems, which allows the deterministic and reversible transfer of the information between the flying photons and the optical transition of a stationary atom. The realization of such systems in the solid-state gives the possibility of fabricating integrated and scalable quantum devices. With this objective, in this thesis work, we study the light-matter interface provided by a single semiconductor quantum dot, acting as an artificial atom, deterministically coupled to a micropillar cavity. Such a device is shown to be an efficient emitter and receiver of single photons, and is used to implement basic quantum functionalities.First, under resonant optical excitation, the device is shown to act as a very bright source of single photons. The strong acceleration of the spontaneous emission in the cavity and the electrical control of the structure, allow generating highly indistinguishable photons with a record brightness. This new generation of single photon sources can be used to generate path entangled NOON states. Such entangled states are important resources for sensing application, but their full characterizatiob has been scarcely studied. We propose here a novel tomography method to fully characterize path entangled N00N state and experimentally demonstrate the method to derive the density matrix of a two-photon path entangled state. Finally, we study the effect of the quantum dot-cavity device as a non-linear filter. The optimal light matter interface achieved here leads to the observation of an optical nonlinear response at the level of a single incident photon. This effect is used to demonstrate the filtering of single photon Fock state from classical incident light pulses. This opens the way towards the realization of efficient photon-photon effective interactions in the solid state, a fundamental step to overcome the limitations arising from the probabilistic operations of linear optical gates that are currently employed in quantum computation and communication.