Excitation and coupling of dual resonance modes in Si/Au hybrid nanosphere

The hybrid nanosphere (NS) is an efficient resonance-coupled nanoplatform, which has important applications in the integrated on-chip nanoscale white sources and nanophotonics devices. In this paper, the Si/Au hybrid NS is acted as a resonance-coupled nanoplatform to combinate Mie resonance and surface plasmon resonance. The excited magnetic dipole resonance (MDR) of Si NS can significantly enhance its quantum efficiency of white-light emission. However, the characteristic wavelength corresponding to MDR of Si NS with a larger diameter (d) will be close to or longer than the absorption limit (∼1100 nm). Fortunately, it was found that the electric resonance coupling in Si/Au hybrid NS with larger size can circumvent the absorption limit of Si NS at the near-infrared band and size limitation of NS to modulate its fluorescence radiation, exploiting a novel strategy for the wider spectral excitation of indirect band gap silicon nanostructured white light source.