Long-range interaction of localized surface plasmons in periodic and random patterns of Au nanoparticles

The plasmon resonance of periodic and random arrays of Au-nanodiscs and nano-squares was investigated experimentally and numerically. By randomization, plasmon resonance spectra become broadened, however, the electro-magnetic field enhancement is augmented by a factor of 10-10 times at some specific wavelength as shown by the finite-element time-domain calculations. The spatial localization takes place at a fewer hot-spots. The randomized structures are promising for the applications in opto-electronics, sensing and light harvesting