  We compare the optical response of isolated nanowires, double-wire systems,
and Pi-structures, and show that their radiation is well described in terms of
their electric and magnetic dipole moments. We also show that both dielectric
permittivity and magnetic permeability can be negative at optical and near
infrared frequencies, and demonstrate the connection between the geometry of
the system and its resonance characteristics. We conclude that plasmonic
nanowires can be employed for developing novel negative-index materials.
Finally, we demonstrate that it is possible to construct a nanowire-based
"transparent nanoresonator" with dramatically enhanced intensity and metal
concentration below 5 %.
