Quality of photon antibunching in two cavity-waveguide arrangements on a chip

A quantum emitter coupled to an optical bimodal cavity in the solid-state implementation has recently proven to be an excellent platform for coherent generation of nonclassical light on a chip. However, the impacts of the structural couplings between the photonic modes via different arrangements of optical cavity and waveguide are rarely considered. Here, we explore in detail the characteristics of the photon antibunching in bimodal cavity quantum electrodynamics (QED) via taking into account two different cavity-waveguide arrangements: (i) an inline geometry and (ii) a side-coupled geometry. In our scheme, both cavity modes are simultaneously coupled to a two-level emitter but are not directly coupled to each other, owing to their orthogonal polarizations. It is clearly shown that the quality of the photon antibunching in the bimodal cavity QED, namely, the smallness of the second-order intensity correlation function at zero time, is closely related to the cavity-waveguide arrangements. The optimal photon antibunching can be achieved in the side-coupled geometry and the antibunching quality is about two orders of magnitude lower than that in the inline geometry. This enhancement of the photon antibunching is ascribed to the combination of two kinds of quantum interference effects in the waveguide-cavity QED system. We also find that the side-coupled architecture can make the device robust against the frequency mismatch between the two cavity modes, as compared to the inline geometry. In addition, we find that this mismatch can be used to generate better antibunching. The realization of our proposal with existing cavity-waveguide QED architectures is also discussed.1 MoreReceived 15 September 2018DOI:https://doi.org/10.1103/PhysRevA.98.053801©2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCavity quantum electrodynamicsQuantum description of light-matter interactionQuantum interference effectsTechniquesCavity resonatorsAtomic, Molecular & Optical