Vol. 49, Issue 4, pp. 655-667 (2019)

Abstract

A core-shell nanocube antenna is proposed to numerically simulate broadband unidirectional scattering. Comparing the scattering of a dielectric nanocube and core-shell nanocube, it is found that the core-shell nanocube has a higher forward/backward ratio and better unidirectional scattering efficiency. In order to further enhance forward scattering efficiency and reduce the side-lobe of scattering, the particle chain of core-shell nanocubes is proposed by arranging multiple nanoparticles. It is possible to achieve better unidirectional scattering over a wide spectral range. In addition, we also numerically studied the effect of the gap between the particles and the radius of the metal core on unidirectional scattering. It is demonstrated that the optimal gap should be selected to achieve ideal unidirectional forward scattering. The unique optical properties of core-shell nanocubes have important practical applications particularly in the fields of nanoantennas, photovoltaic devices, and nanolasers that require reflection suppression.