Geometrical techniques for controlling electromagnetic waves II
14:00 Invited talk : Modeling Artificial Structures Through Accelerated Multilayered Periodic Potentials
Guido Valerio (1),Ferhat Turker Celepcikay (2),Donald R. Wilton (3),David R. Jackson (3),Alessandro Galli (4)
(1)UPMC University (France) , (2)Turgut Ozal University (Turkey) , (3)University of Houston (USA) , (4)Sapienza University (Italy) In this paper we describe the acceleration of series expressing the potentials due to periodic vertical currents in layered media. This computation is relevant to the numerical study of periodic structures for synthesizing artificial materials or surfaces. Asymptotic extractions are performed, leading to faster-converging expressions. These extracted terms are then efficiently computed through a modified Ewald summation method, thus achieving Gaussian convergence.
14:20 Invited talk : Geometries, Rays, and Waves
Paul Kinsler, Martin W. McCall
Imperial College London (United Kingdom) The use of a generalized and orientation dependent refractive index allows us to model the entirety of possible ray-based transformation devices, including cloaks and carpets. We show here how such ray devices generate constitutive parameters that match full wave theories design to a remarkable extent, notably for both electromagnetism and pressure acoustics. However, comparative full wave FDTD simulations reveal that boundary impedance matching as in e.g. the original invisibility cloak is not sufficient to achieve perfect invisibility.
14:40 Invited talk : Omnidirectional Concentrators and Absorbers: Trapping Light at any Angle
Alexander Kildishev, Ludmila Prokopeva
Purdue University (USA) We present a general approach for ray tracing in 3D omnidirectional concentrators with the refractive index distribution being conformally scaled from the exterior boundary up to the absorbing core. We illustrate our theory with examples of trapping the obliquely incident light in cylindrical, spherical, and spheroidal concentrators. The proposed approach can be used for modeling conformally scaled graded index lenses for arbitrary incidence angles, the method is essential for non-imaging optics applications in IR-sensing, mobile photovoltaics, and microwave focusing.
15:00 : Exact analysis of a Veselago Lens using eigenstates of Maxwell's equations
David J. Bergman, Asaf Farhi
Tel Aviv University (Israel) A new approach is applied to the discussion of perfect imaging by a Veselago Lens. This is based upon the eigenstates of Maxwell's equations. Sub-wavelength resolution is obtained, but not at the geometric optics foci.
15:15 : Perfect light absorption and plasmonic sensing from self-assembled optical metasurfaces
Fumin Huang (1),Matthew Millyard (1),Stacey Drakeley (1),Antony Murphy (1),Richard White (2),Elisabetta Spigone (2),Jani Kivioja (2),Jeremy Baumberg (3)
(1)Queen's University Belfast (United Kingdom) , (2)Nokia Research Centre (United Kingdom) , (3)University of Cambridge (United Kingdom) We present experimental results about a new class of optical metasurfaces which exhibit omnidirectional near-zero reflectance in the optical frequency region. The zero reflectance film shows optimal plasmonic sensing performance, exhibiting the largest spectral shift per unit refractive index. These metasurfaces can be manufactured at large scales through cost-effective self-assembly methods, making them potential candidates for widespread applications.
15:30 : Controlling Light in Transformation Optical Waveguides through an enhanced thermo-optic effect
Hui Liu (1),Chong Sheng (1),Shining Zhu (1),Dentcho Genov (2)
(1)Nanjing University (China) , (2)Louisiana Tech University (USA) A controlling laser produces inhomogeneous refractive index inside a waveguide through the photothermal effect. The trajectory of waveguide beam is continuously tuned. This work provides an approach toward optical control of transformation optical devices.