Enhancement of evanescent field of metamaterials–core slab waveguide using metamaterials-buffer layer

A metamaterials (MTM)-core slab waveguide overlaid with a MTM buffer layer was used to enhance an evanescent field. The guided modes were graphically obtained by a new dispersion equation of the four-layered MTM-core slab waveguide modeled to have four layers, including an air layer, buffer layer, slab waveguide layer, and substrate layer. With the tuning of the refractive index and width of the MTM-buffer layer, abuffer layer with one-tenth of the core-layer width was obtained together with the refractive index of 1.7, making the evanescent field increase up to 1.8 times. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.8.084601]