Non-monotonic shift of the SPR band due to radiative coupling of two dimensional gold nano-particle arrays

In this paper, the surface plasmon resonance (SPR) wavelength of arrangement-dependent gold liner nanochain, square arranged nanoarray and curved nanochain are theoretically studied. Dipolar electrostatic and electrodynamics is concerned. For the liner chains, with increase number of the sphere, the plasmon peak wavelength varies non-monotonically in p-polarization, whereas it varies monotonically in s-polarization. For the square arranged array, it has greater resonance wavelength variations, and resonance wavelength can change from red shift to blue shift simply by changing the distance. The behavior of resonance wavelength for curved chain is similar to that of liner chain, and curved chain can be considered as a mixture of several short liner chains. The real part of additional field factor affects the resonance wavelength, and the real electrodynamics' part of additional field factor causes non-monotonic shift of resonance wavelength. According to these results, controlling the resonance wavelength by changing the shape of nanoarray is attainable.