  Using propagating surface plasmons (SPs) on silver nanowire (NW), we
demonstrate that focused laser light at the end of silver nanowire can excite
single quantum dot (QD) microns away from the excitation spot. The QD-NW
interaction allows the excited QD convert part of its energy into propagating
SPs which then can be detected at the remote sites. Simultaneous multi-QDs
remote-excitation and detection are also realized. Furthermore, the tight
confinement of propagating SPs around the NW surface enables selective
excitation of QDs very close in space, which cannot be realized under
conventional excitation condition. This remote excitation and detection
approach may find applications in optical imaging and sensing of chemical and
biological systems.
