Electromagnetic energy transport via linear chains of silver nanoparticles.

We propose the idea of a subwavelength-sized light guide represented by a linear chain of spherical metal nanoparticles in which light is transmitted by electrodynamic interparticle coupling. The light-transport properties of this system are investigated by use of model calculations based on generalized Mie theory. Considering Ag particles of 50-nm diameter, we find optimum guiding conditions for an interparticle spacing of 25 nm, and a corresponding 1/e signal-damping length of 900 nm is evaluated. The proposed principle of optical energy transport may be useful for subwavelength transmission lines within integrated optics circuits and for near-field optical microscopy.