Open AccessTunable subwavelength hot spot of dipole nanostructure based on VO_2 phase transition
Author(s) -
Jun-Bum Park,
Il-Min Lee,
Seung–Yeol Lee,
Kyuho Kim,
Dabin Choi,
Eui Young Song,
Byoungho Lee
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.015205
Subject(s) - materials science , hot spot (computer programming) , nanostructure , dipole , optics , photonics , wavelength , phase (matter) , optoelectronics , phase transition , semiconductor , intensity (physics) , nanotechnology , condensed matter physics , physics , quantum mechanics , computer science , operating system
We propose a novel approach to generate and tune a hot spot in a dipole nanostructure of vanadium dioxide (VO2) laid on a gold (Au) substrate. By inducing a phase transition of the VO2, the spatial and spectral distributions of the hot spot generated in the feed gap of the dipole can be tuned. Our numerical simulation based on a finite-element method shows a strong intensity enhancement difference and tunability near the wavelength of 678 nm, where the hot spot shows 172-fold intensity enhancement when VO2 is in the semiconductor phase. The physical mechanisms of forming the hot spots at the two-different phases are discussed. Based on our analysis, the effects of geometric parameters in our dipole structure are investigated with an aim of enhancing the intensity and the tunability. We hope that the proposed nanostructure opens up a practical approach for the tunable near-field nano-photonic devices.