Transparent Nanoprobes in Integrated Plasmonic Circuits Based on Plasmonic Cloaking

Using exotic subwavelength structures to conceal objects has generated sensational articles about ``invisibility cloaks'', but there are more subtle applications as well. This study extends one cloaking technique from the usual free-space geometries to the guided-wave structures of optical communications circuitry. Nanoprobes in the light path of an integrated plasmonic circuit can be efficiently hidden, and although the cloaked objects do not disturb the flow of light, they nevertheless do interact with it. This permits the probes to exchange information with the outside world, and so cunningly these ``invisibility cloaks'' can be exploited to produce signal antennas or detectors.