Controlling photon emission by single emitters with nanostructures is crucial for scalable on-chip information processing. Nowadays, nanoresonators can affect the lifetime of linear dipole emitters, while nanoantennas can steer the emission direction. Expanding this control to the emission of orbital angular momentum-changing transitions would enable a future coupling between solid state and photonic qubits. As these transitions are associated with circular dipoles, such control requires knowledge of the interaction of a complex dipole with optical eigenstates containing local helicity. We experimentally map the coupling of classical, circular dipoles to photonic modes in a photonic crystal waveguide. We show that, depending on the combination of the local helicity of the mode and the dipole helicity, circular dipoles can couple to left- or rightwards propagating modes with a near-unity directionality. The experimental maps are in excellent agreement with calculations. Our measurements, therefore, demonstrate the possibility of coupling the spin to photonic pathway.

NPG
dx.doi.org/10.1038/ncomms7695
Nature Commun.

le Feber, B, Rotenberg, N, & Kuipers, L.K. (2015). Nanophotonic control of circular dipole emission. Nature Commun., 6(Article number: 6695), 1–6. doi:10.1038/ncomms7695