Title

Chiral Metamaterials of Plasmonic Slanted Nanoapertures with Symmetry Breaking

Abstract

We propose a universal design scheme for a new type of chiral metamaterials based on plasmonic slanted nanoapertures simply milled in a single metal layer. Strong optical chirality is introduced by tilting nanoapertures with almost arbitrary shape along a certain direction to break all the mirror symmetries. As a typical example, chiral metamaterial based on slanted split-ring apertures is demonstrated with giant circular dichroism in transmission (CDT) over 78% at 760 nm. We reveal that the high CDT originates from the circularly dichroic mode coupling process in the slanted nanoapertures induced by spin-dependent field overlap conditions. Furthermore, tunable CDT is presented through the in-plane rotation of nanoapertures to form chiral images with controllable image contrast. Besides, chiral metamaterials with slanted nanoapertures of two other shapes including L-shaped aperture and rectangular aperture are also presented with large circular dichroism. We envision that our demonstrated chiral metamaterials enable promising platforms for a variety of applications in nonlinear optics, chiral imaging and sensing, spectroscopy, and polarization manipulation.

Department(s)

Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center

Comments

The authors acknowledge support from the Office of Naval Research under Grant N00014-16-1-2408, and the National Science Foundation under Grant ECCS-1653032 and DMR1552871. The authors thank the facility support from the Materials Research Center at Missouri S&T. The authors also thank D. Rosenmann and D. A. Czaplewski at the Argonne National Laboratory for the gold film deposition. This work was performed in part at the Center for Nanoscale Materials, a U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences User Facility under Contract No. DE-AC02- 06CH11357.

Keywords and Phrases

Dichroism; Nonlinear optics; Optical design; Plasmons; Surface plasmon resonance; 3D fabrication; Chiral metamaterials; Mode coupling; Plasmonics; Rectangular aperture; Single metal layers; Symmetry-breaking; Metamaterials; Circular dichroism

International Standard Serial Number (ISSN)

1530-6984; 1530-6992

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2018 American Chemical Society (ACS), All rights reserved.

PubMed ID

29206469

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