Nonlocal Effects on Optical Gradient Force from Coupled Surface Plasmon Polaritons in Wire Medium Waveguides

Abstract

We analytically study optical gradient forces from the mutual coupling between surface plasmon polariton (SPP) modes at the interfaces of two wire medium metamaterial waveguides separated by a linear dielectric. Based on the nonlocal model, dispersion properties and optical gradient forces from coupled SPP modes are analyzed mainly and compared with the local case. The forces from the coupled SPP modes are calculated by Maxwell stress tensor. Numerical results show that the nonlocal effects on dispersion properties and optical forces are very large, especially in the case of large propagation constant, and that symmetric (antisymmetric) SPP modes give rise to an attractive (repulsive) interaction, respectively. In addition, the nonlocal effects on the cutoff frequency for the antisymmetric SPP modes are clarified. These properties indicate that the force from the coupled SPPs at wire medium metamaterials offer another avenue for controlling the growth and self-assembling of artificial metamaterials.