Near-field probing of Mie resonances in single TiO.sub.2./sub. microspheres at terahertz frequencies

0440831 - FZÚ 2015 RIV US eng J - Journal Article
Mitrofanov, O. - Dominec, Filip - Kužel, Petr - Reno, J.L. - Brener, I. - Chung, U.-C. - Elissalde, C. - Maglione, M. - Mounaix, P.
Near-field probing of Mie resonances in single TiO₂ microspheres at terahertz frequencies.
Optics Express. Roč. 22, č. 19 (2014), s. 23034-23042. ISSN 1094-4087
R&D Projects: GA ČR(CZ) GA14-25639S
EU Projects: European Commission(XE) 607521 - NOTEDEV
Institutional support: RVO:68378271
Keywords : metamaterials * near-field microscopy * resonators * terahertz imaging
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 3.488, year: 2014

We show experimentally that polycrystalline TiO2 spheres, 20-30 micrometers in diameter, exhibit a magnetic dipole Mie resonance in the THz frequency band with a narrow linewidth. We detect and investigate the magnetic dipole and electric dipole resonances in single high-permittivity TiO2 microspheres, using a near-field probe with a sub-wavelength size aperture and THz time-domain spectroscopy technique. The Mie resonance signatures are observed in the electric field amplitude and phase spectra, as well as in the electric field distribution near the microspheres. The narrow linewidth and the sub-wavelength size make the TiO2 microspheres excellent candidates for realizing low-loss THz metamaterials.
Permanent Link: http://hdl.handle.net/11104/0243935