Investigation of electric/magnetic local interaction between Si photonic-crystal nanocavities and Au meta-atoms

We experimentally investigate nanoscale local interaction in a composite system consisting of dielectric photoniccrystal nanocavity and metallic meta-atoms. The Q factor of the composite system changes by a maximum of about 10 dB based on the relative position and the type of meta-atoms. The emission by meta-atoms dominates the nano-cavity emission when they are in the electric or magnetic antinodes of the cavity field. Circularly polarized emission is achieved by tuning the polarization, the position, and the coupling phase of each meta-atom with respect to the nanocavity. Utilization of the local interaction with meta-atoms is shown to be useful as a new degree of freedom in tailoring the characteristics of nanocavities.