title: Composite functional metasurfaces for multispectral achromatic optics.
abstract: Nanostructured metasurfaces offer unique capabilities for subwavelength control of optical waves. Based on this potential, a large number of metasurfaces have been proposed recently as alternatives to standard optical elements. In most cases, however, these elements suffer from large chromatic aberrations, thus limiting their usefulness for multiwavelength or broadband applications. Here, in order to alleviate the chromatic aberrations of individual diffractive elements, we introduce dense vertical stacking of independent metasurfaces, where each layer is made from a different material, and is optimally designed for a different spectral band. Using this approach, we demonstrate a triply red, green and blue achromatic metalens in the visible range. We further demonstrate functional beam shaping by a self-aligned integrated element for stimulated emission depletion microscopy and a lens that provides anomalous dispersive focusing. These demonstrations lead the way to the realization of ultra-thin superachromatic optical elements showing multiple functionalities-all in a single nanostructured ultra-thin element.
authors.affiliation: Department of Physical Electronics, Fleischman Faculty of Engineering, Tel-Aviv University, 69978 Tel-Aviv, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Avayu
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Euclides
authors.initials: E
authors.lastname: Almeida
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Yehiam
authors.identifier: 0000-0003-0064-6605
authors.initials: Y
authors.lastname: Prior
authors.affiliation: Department of Physical Electronics, Fleischman Faculty of Engineering, Tel-Aviv University, 69978 Tel-Aviv, Israel.|Tel-Aviv University Center for Light-Matter-Interaction, Tel Aviv 76100, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Ellenbogen