Surface plasmon coupling to nanoscale Schottky-type electrical detectors

We have investigated the near-field coupling of surface plasmons to a titanium/CdS nanowire interface for two different device configurations. A bare aluminum grating on an underlying aluminum layer exhibited the expected stronger electrical signal for perpendicular versus parallel light polarization. An opposite intensity ratio was detected when the grating and the Schottky contact are connected via an aluminum-silica-aluminum sandwich structure. Based upon finite difference time domain device simulations, the enhanced coupling for parallel polarization is attributed to the emergence of a transversal electric wave within the metal-insulator-metal structure. (C) 2010 American Institute of Physics. [doi:10.1063/1.3503534]