Influence of the Purcell effect on the purity of bright single photon sources

Purcell effect is a powerful tool to efficiently collect single photons emitted by semiconductor quantum dots. However, it is common to observe a degraded single photon purity when a quantum dot is inserted in an optical microcavity. Here, we investigate the role of the cavity coupling on the single photon purity for a quantum dot deterministically coupled to a pillar cavity mode. We show that the degradation of the purity cannot be attributed to cavity feeding effects but is fully explained by recapture processes. A good single photon purity is therefore easily restored using an intra-dot excitation scheme.