Local field enhancement and its wavelength tuning in metal nanoparticle arrays

Plasmon resonances in metal nanoparticle (NP) arrays are tunable. Here, we show that narrowband field enhancement in the arrayed NPs are also tunable and its magnitude is even larger than that of single NPs, due to recycling of the scattering loss. In addition, we disclose the non-monotonous dependence of the field enhancement on the tuning wavelength, and demonstrate anisotropy resonance and field enhancement in the arrayed nanostructures. Their dual resonance characteristics may be applied in designing photoluminescence and lasing devices to enhance both the excitation and photon emission efficiencies. (C) 2019 The Japan Society of Applied Physics