title: Near-Field Imaging of Phased Array Metasurfaces.
abstract: Phased-antenna metasurfaces can impart abrupt, spatially dependent changes to the amplitude, phase, and polarization of light and thus mold wavefronts in a desired fashion. Here we present an experimental and computational near-field study of metasurfaces based on near-resonant V-shaped antennas and connect their near- and far-field optical responses. We show that far fields can be obtained from limited, experimentally obtained knowledge of the near fields, paving the way for experimental near-field characterization of metasurfaces and other optical nanostructures and prediction of their far fields from the near-field measurements.
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.|‡Fakultät für Physik, Ludwig-Maximilians-Universität, 80799 München, Germany.
authors.forename: Bernhard J
authors.initials: BJ
authors.lastname: Bohn
authors.affiliation: §CIC nanoGUNE, 20018 Donostia, San Sebastian, Basque Country, Spain.
authors.forename: Martin
authors.initials: M
authors.lastname: Schnell
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.|∥Department of Electrical and Computer Engineering, University of Wisconsin - Madison, Madison, Wisconsin 53706, United States.
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Kats
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Francesco
authors.initials: F
authors.lastname: Aieta
authors.affiliation: #CIC nanoGUNE and EHU/UPV, 20018 Donostia, San Sebastian, Basque Country, Spain.|⊥IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Basque Country, Spain.
authors.forename: Rainer
authors.initials: R
authors.lastname: Hillenbrand
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
keywords: Optical antennas; SNOM; metasurfaces; near field; plasmonics