Substrate-mediated sub-diffraction guiding of optical signals through a linear chain of metal nanoparticles: Polarization dependence and the role of the dispersion relation

We theoretically investigate the efficiency of transmitting optical signals through a linear chain consisting of identical and equidistantly spaced silver nanoparticles in the presence of a reflecting substrate. The energy exchange between surface plasmon polaritons of the chain and the substrate can give rise to an increased transmission. We focus on the effects of the polar- ization of the excitation and the role of the dispersion relation of the collective chain-substrate modes

Asymmetric transport of light in linearly arrayed metallic nano-particles

A strong asymmetric light transport in a linear chain of spherical and equidistantly spaced silver metal nano-particles (MNPs) located near a substrate is reported. The contrast ratio of the proposed structure is above 0.95. We have studied the propagation of light in the array with respect to the metal and the size of the last nano-particle of the chain and the nature of the substrate. It is shown also that the presence of a copper or gold substrate enhance the guiding properties of the array. This structure opens the possibility to design various optical devices such as broadband antennae and optical diodes