Sub-wavelength plasmonic modes in a conductor-gap-dielectric system with a nanoscale gap

• DOI: 10.1364/oe.18.000348
• Publication Date: 2009-12-24T14:28:01Z
• Authors: Ivan Avrutsky; Richard Soref; Walter Buchwald
• Keywords: Cladding (metalworking); Cutoff frequency

We study guided modes in a conductor-gap-dielectric (CGD) system that includes low-index dielectric gap layer of deep sub-wavelength thickness sandwiched between conductor and high-index cladding. Analysis the dispersion equation for CGD provides an analytical estimation cut-off layer. This mode is unusual because it exists when less than cutoff thickness. In direction normal to interfaces, modal electric field tightly confined within gap. Sub-wavelength lateral confinement readily provided by spatial variation gap-layer thickness: localizes at narrowest Various schemes are proposed verified numerical simulations. Possible applications include surface-plasmon nano-lasers (SPASERs) sensors. If these plasmonic waveguides scaled operation far infrared rather telecomm wavelengths, then propagation losses dramatically reduced, thereby enabling construction practical chip-scale integrated circuits or PLICs.