title: Single-mode plasmonic waveguiding properties of metal nanowires with dielectric substrates.
abstract: Single-mode plasmonic waveguiding properties of metal nanowires with dielectric substrates are investigated using a finite-element method. Au and Ag are selected as plasmonic materials for nanowire waveguides with diameters down to 5-nm-level. Typical dielectric materials with relatively low to high refractive indices, including magnesium fluoride (MgF2), silica (SiO2), indium tin oxide (ITO) and titanium dioxide (TiO2), are used as supporting substrates. Basic waveguiding properties, including propagation constants, power distributions, effective mode areas, propagation distances and losses are obtained at the typical plasmonic resonance wavelength of 660 nm. Compared to that of a freestanding nanowire, the mode area of a substrate-supported nanowire could be much smaller while maintaining an acceptable propagation length. For example, the mode area and propagation length of a 100-nm-diameter Ag nanowire with a MgF2 substrate are about 0.004 μm2 and 3.4 μm, respectively. The dependences of waveguiding properties on geometric and material parameters of the nanowire-substrate system are also provided. Our results may provide valuable references for waveguiding dielectric-supported metal nanowires for practical applications.
authors.affiliation: Department of Physics and Institute of Nanoscience, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Yipei
authors.initials: Y
authors.lastname: Wang
authors.forename: Yaoguang
authors.initials: Y
authors.lastname: Ma
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.forename: Limin
authors.initials: L
authors.lastname: Tong
mesh_terms: D017076:Computer-Aided Design; D017097:Electric Impedance; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*