Abstract : Cavity Quantum Electrodynamics (CQED) studies the light-matter interaction at the most fundamental level, ie when matter is well described by a two-level system and when light can be reduced to a single mode of the electromagnetic eld. The rst eects of CQED have been demonstrated in the 80ies in the eld of atomic physics. Thanks to impressive progress in micro and nanoscale fabrication techniques, Purcell eect and strong coupling could be reached for articial atoms coupled to semiconducting cavities during the past decade. Those systems are interesting for their high scalability and their potential for on-chip realisation. Within this context, semiconducting quantum dots (QD) are very promising candidates. However, due to the solid surrounding matrix, which is a source of decoherence, those systems diverge from the paradigm of atomic physics. For QDs in particular, this coupling can be important and thus highly modies the results. We propose here to study the measurement of the Purcell factor, which is an important factor of merit for CQED, in the case of a QD embedded in a micropillar type cavity. Several approaches are presented, which are compared to one-another, and which take into account the specicities of QDs. We show that the use of a more precise model is necessary to interpret the obtained results. The last chapter is devoted to an interesting application for this type of systems which consists in using the saturation of the quantum dot to implement a optical non-linearity at the single photon level.