Selective optical-optical switching for planar plasmonic waveguides and nodes

Two nodes are studied as means to perform selective optical-optical switching of four planar thin surface plasmon waveguides by interfering TEM10, TEM01, and TEM00 light beams incident upon a node. One node uses a flat-apex pyramidal reflector to reflect the incident light toward the waveguides' ends. An alternative node is a simple square aperture, which couples surface plasmons through light diffraction at the aperture's edges. Numerical calculations predict switching contrast, coupling efficiencies, and cross-talk between waveguides. Individually turned-off waveguides are shown to have their coupled surface plasmons attenuated by at least -10 dB and up to -21 dB. (c) 2008 Optical Society of America.