Particle plasmons resonant characteristics in arrays of strongly coupled gold nanoparticles

Using the finite difference time domain (FDTD) method, we investigated the optical properties of a periodic array of strongly coupled gold nanoparticles (MNPs). We show the two kinds properties of transmission spectra with both different interparticle spaces and different radii of the particles. It is found that some distinct extra resonant peaks appear in the forbidden band gap and the resonant frequency depends strongly on the space between the particles and the radius of the particles. Based on the localized nature of the field distribution, we also show clearly the presence of local plasmons resonant modes that originate from quadrupole plasmon polaritons.