“Hot spots” induced near-field enhancements in Au nanoshell and Au nanoshell dimer

摘要: The influence of “hot spots” on the near-field properties Au nanoshell and dimers have been investigated by means finite element method. It is found with increasing pinhole radius R that maximal enhancement for parallel to polarization increases from 17.906 at R=0 nm 36.979 R=0.8 nm, then almost shows a negligible dependence. Large electric fields also can be observed inside perpendicular polarization, which radius. dimer depends strongly propagation directions incident light. Exponential decay behavior field in junction as function separation. Furthermore, very strong between two nanoshells when pinholes are located near gap nanoshells.