Coherence and statistics of a one-atom laser in a photonic crystal microcavity

Through calculating the quantum degree of second-order coherence and photon number distribution numerically, we investigate the coherence and statistics of a one-atom laser where a coherently driven two-level atom is coupled to a photonic crystal microcavity. By going beyond the previous theoretical studies, we show that in the presence of non-secular terms the cavity field displays a variable degree of second-order coherence as a function of discontinuities in the photonic density of states. The cavity field is characterized by photon antibunching and sub-Poissonian statistics for large discontinuities. In the case of a vanishing photonic density of states on the lower Mollow sideband, we can obtain only weak antibunching. If the jump in the photonic density of states is small, the bunching and super-Poissonian statistics field is generated in the cavity. Consequently, the cavity field exhibits certain non-classical features when non-secular interaction is included into the dynamics of the system. The theoretical analysis and numerical calculations presented here coincide with recent experimental observations.