Coupling of Cutoff Modes in a Chain of Nonlinear Metallic Nanorods**Supported by the National Basic Research Program of China under Grant No 2012CB921502, the National Natural Science Foundation of China under Grant Nos 11374150, 11074120, 11274163 and 11274164, and the Priority Academic Program Development of Jiangsu Higher Education Institutions of China.

Abstract

We study the coupling of cutoff modes in a chain of metallic nanorods embedded in a Kerr nonlinear optical medium with strong near-field interactions analytically. Based on a quasidiscreteness approach, we derive a system of two coupled nonlinear Schrödinger equations governing the evolution of the envelopes of these modes. It is shown that this system supports a variety of subwavelength plasmonic lattice vector solitons of the bright-bright, bright-dark, dark-bright, and dark-dark type through a cross-phase modulation. It is also shown that the existence of different solitons depends strongly on the gap width scaled for the rod radius and the type of nonlinearity of the embedded medium.