摘要
A transversal mode with zero group velocity and non-zero phase velocity that can exist in chains of silver nano- spheres in the optical frequency range was theoretically studied. It is shown that the external source radiating a narrow-band non-monochromatic signal can excite in the chain a mixture of standing and slowly travelling waves. The standing wave com- ponent (named as resonator mode) is strongly dominating. The physical reason of such a regime is a sign-varying distribution of power flux over the cross section of the chain. This situation is similar to the scenario of the propagation of a wave along the boundary between the right-handed and left-handed media where the spatial distribution of the light intensity is vortex. However, in the present case there is no boundary between media and the boundary between the positive and negative power fluxes is a cylindric tube in free space whose axis is the axis of the chain.
A transversal mode with zero group velocity and non-zero phase velocity that can exist in chains of silver nanospheres in the optical frequency range was theoretically studied. It is shown that the external source radiating a narrow-band non-monochromatic signal can excite in the chain a mixture of standing and slowly travelling waves. The standing wave component (named as resonator mode) is strongly dominating. The physical reason of such a regime is a sign-varying distribution of power flux over the cross section of the chain. This situation is similar to the scenario of the propagation of a wave along the boundary between the right-handed and left-handed media where the spatial distribution of the light intensity is vortex. However, in the present case there is no boundary between media and the boundary between the positive and negative power fluxes is a cylindric tube in free space whose axis is the axis of the chain.