Structured light in metamaterials II

14:00 Invited talk : The singularities of crystal optics, including biaxiality, chirality, dichroism and bianisotropy

Michael Berry

University of Bristol (United Kingdom)

Crystal optics requires many parameters. Navigating in crystal space to reveal the essential optical physics involves three types of singularity. For each point in crystal space, there are singularities in the two-dimensional wave-direction space. (1) are degeneracies: the optic axes, namely Hamilton-cone intersections of the index surfaces, or (with absorption) branch points. (2) C points and (3) L lines, where an eigenpolarization is purely circular or purely linear. In crystal space, these singularities interact in topologically identifiable ways.
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14:20 Invited talk : Gate-tunable conducting oxide metasurfaces

Yao-Wei Huang (1),Ho Wai Howard Lee (2),Ruzan Sokhoyan (2),Krishnan Thyagarajan (2),Seunghoon Han (2),Georgia Papadakis (2),Din Ping Tsai (3),Harry A. Atwater (2)

(1)California Institute of Technology (Taiwan) , (2)California Institute of Technology (USA) , (3)National Taiwan University (Taiwan)

We demonstrate an electrically tunable metasurface element capable of providing phase shifts of nearly 2Pi based on conducting oxide field-effect dynamics. We further show the controllable diffraction patterns by selective gating the nanoantenna array to a 2-level or 4-level grating system with different applied biases. This work provides insight towards dynamic beam steering, reconfigurable imaging, and high capacity data storage based on electrically tunable metasurfaces.
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14:40 Invited talk : Three-Dimensional Metasurface Carpet Cloak

Xiang Zhang, Xingjie Ni

University of California (USA)

We show that ultrathin metasurfaces can be used for creating transformation optics devices by its phase modulation capability. We here experimentally demonstrate a three-dimensional metasurface carpet cloak using the concept of reflection phase manipulation. We design carpet cloak so that at each local point on the interface of the cloaked region the phase of the light scattered by the interface is the same as that reflected from a flat mirror.
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15:00 Invited talk : Active Dielectric and Metallic Metasurfaces: Strong Coupling, Tuning and Nonlinearities

Igal Brener

Sandia National Labs (USA)

Metasurfaces, or arrays of 2D metamaterial resonators can couple efficiently to emitters and several excitations in semiconductors. I will present an overview of active metasurfaces, both metallic and dielectric, and different coupling mechanisms that can be used for active tuning and enhancement of optical nonlinearities.
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15:20 Invited talk : Left-handed optomechanics with dielectric metasurfaces

Davit Hakobyan (1),Etienne Brasselet (2)

(1)University of Bordeaux (France) , (2)University of Bordeaux (France)

Counter-intuitive optomechanical effects using dielectric metasurfaces is reported. It is shown experimentally that light-scattering from a dielectric material with subwavelength features can lead to the angular analog of so-called negative optical forces.
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15:40 Invited talk : Structured materials and structured light for photonics

Robert Boyd, M. Zahirul Alam, Peter Banzer, Saumya Choudhary, Israel De Leon, Matthew Horton, Ebrahim Karimi, Sebastian A. Schulz, Jeremy Upham

University of Ottawa (Canada)

We review recent work aimed at studying the optical properties of structured materials. We are particularly concerned with determining how the nonlinear optical properties of materials depend on the nature of the structuring. We also explore specific examples of structured surfaces. For instance, we study the nonlinear optical properties of a surface plasmon polariton, and we show how to form a metasurface that will convert a Gaussian laser beam to one that carries orbital angular momentum.
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