Coupling of surface plasmon waves in metal/dielectric gap waveguides and single interface waveguides

Low-loss, high-integration photonic routing may be realized with a surface plasmon waveguide of the vertical metal/dielectric interface on a substrate. End-fire coupling of light into surface plasmon waves through a metal/dielectric/metal gap waveguide coupler and conversion of surface plasmon modes between the gap waveguides and single metal/dielectric interface waveguides is discussed. High efficiency in coupling of incident light into surface plasmons for waveguiding is quantitatively shown. The coupling efficiency of surface plasmons between the gap waveguide and the conjunct single interface waveguide can reach as high as more than 80% at the wavelength of 600 nm. (c) 2007 Optical Society of America.