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Proceedings Paper

Spin controlled transmission in dielectric metasurfaces (Conference Presentation)
Author(s): Amr M. Shaltout; Jorik van de Groep; Yefei Wang; Mark L. Brongersma

Paper Abstract

Spin polarized light is commonly used to sense chiral structures, which are very recurrent in biological materials and organic compounds. Therefore, manipulating optical spin has many applications in bio-sensing, stereochemistry, and DNA structural analysis. Devices that demonstrate spin dependent optical response typically require multi-layer bianaisotropic structures or biaxial crystals. Dielectric metasurfaces can provide lighter, simpler and more efficient approach. We design and implement a silicon based metasurface that transmit only one optical spin and reflect the other. Utilizing an array of highly anisotropic rectangular silicon nano-antennas with high aspect ratio. These nano-antenna induce two kinds of optical phase-shifts which are independently controlled. One of them is the phase-shift induced by electric and magnetic Mie resonances excited inside the Silicon nano-antennas which is controlled by antennas' dimensions, while the other one is the Pancharatnam-Berry phase-shift controlled by the geometric orientations of the nano-antennas. A planar array of Si nano-antennas with different dimensions (i.e, different Mie Scattering phases), and different orientations (i.e, different geometric phases) are judiciously designed to achieve the spin based performance. The Mie phase and geometric phase coherently interact to interfere constructively for one optical spin and destructively for the other, leading to the differential optical response between opposite spins. The effect is experimentally demonstrated in the visible and NIR spectral range.

Paper Details

Date Published: 17 September 2018
Proc. SPIE 10719, Metamaterials, Metadevices, and Metasystems 2018, 1071916 (17 September 2018); doi: 10.1117/12.2321236
Show Author Affiliations
Amr M. Shaltout, Stanford Univ. (United States)
Jorik van de Groep, Stanford Univ. (United States)
Yefei Wang, Stanford Univ. (United States)
Mark L. Brongersma, Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 10719:
Metamaterials, Metadevices, and Metasystems 2018
Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)

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