Dr. Mario Hentschel

4th Physics Institute and Research Center SCoPE, University of Stuttgart

We experimentally implement a novel strategy for dielectric nanophotonics: Resonant subwavelength localized confinement of light in air. We demonstrate that voids created in high-index dielectric host materials support localized resonant modes with exceptional optical properties. Due to the confinement in air, the modes do not suffer from the loss and dispersion of the dielectric host medium. We experimentally realize these resonant Mie voids by focused ion beam milling as well as reactive ion etching into bulk silicon and gallium arsenide wafers and experimentally demonstrate resonant light confinement down to the UV spectral range at 265 nm (4.68 eV). Furthermore, we utilize the bright, intense, and naturalistic colours for nanoscale colour printing.  Mie voids are also  an ideal platform for refractive index sensing in single voids with volumes down to 100 attoliters and sensitivities On the order of 400 nm per refractive index unit. Taking the signal-to-noise ratio of our measurements into account,  we are able to detect refractive index changes as small as 6.9 x 10-4 in a defined volume of just 850 attoliters. We also demonstrate the use of Mie voids for the all-optical detection, sizing, and counting of micro- and  nanoplastic particles.