Switchable Plasmonic–Dielectric Resonators with Metal–Insulator Transitions

• Published in: ACS photonics Vol. 5; no. 2; pp. 371 - 377
• Main Authors: Butakov, Nikita A, Valmianski, Ilya, Lewi, Tomer, Urban, Christian, Ren, Zhensong, Mikhailovsky, Alexander A, Wilson, Stephen D, Schuller, Ivan K, Schuller, Jon A
• Format: Journal Article
• Language: English
• Published: American Chemical Society 21.02.2018
• Subjects: phase change materials; vanadium dioxide; tunable metasurfaces; metal−insulator transition
• ISSN: 2330-4022; 2330-4022
• DOI: 10.1021/acsphotonics.7b00334

Nanophotonic resonators offer the ability to design nanoscale optical elements and engineered materials with unconventional properties. Dielectric-based resonators intrinsically support a complete multipolar resonant response with low absorption, while metallic resonators provide extreme light confinement and enhanced photon–electron interactions. Here, we construct resonators out of a prototypical metal–insulator transition material, vanadium dioxide (VO2), and demonstrate switching between dielectric and plasmonic resonances. We first characterize the temperature-dependent infrared optical constants of VO2 single crystals and thin-films. We then fabricate VO2 wire arrays and disk arrays. We show that wire resonators support dielectric resonances at low temperatures, a damped scattering response at intermediate temperatures, and plasmonic resonances at high temperatures. In disk resonators, however, upon heating, there is a pronounced enhancement of scattering at intermediate temperatures and a substantial narrowing of the phase transition. These findings may lead to the design of novel nanophotonic devices that incorporate thermally switchable plasmonic–dielectric behavior.