The mid-infrared (MIR) region is one of the most thriving spectral regions as it contains the vibrational resonances of several molecules of interest, as well as the absorption bands for hot bodies. In this work, we propose a novel dielectric waveguide that confines the light in a nanoscale air gap. This dielectric waveguide is a suitable candidate for on-chip sensing. Detailed dispersion analysis of this 3D waveguide is also provided. The effect of the refractive index change in the gap is studied and shows very high sensitivity and causes significant changes in the modal parameters. We also show that these waveguide modes exhibit plasmonic-like characteristics at the MIR region with controllable plasma frequency, without the inclusion of any metals. This waveguide is also utilized in various on-chip applications with nanoscale confinement at the MIR region.

Date Published: 16 March 2015
PDF: 6 pages
Proc. SPIE 9357, Physics and Simulation of Optoelectronic Devices XXIII, 93571G (16 March 2015); doi: 10.1117/12.2078331

Published in SPIE Proceedings Vol. 9357:
Physics and Simulation of Optoelectronic Devices XXIII
Bernd Witzigmann; Marek Osiński; Fritz Henneberger; Yasuhiko Arakawa, Editor(s)