Generation of Vectorial Optical Fields with Slot-Antenna-Based Metasurface

Document Type

Article

Publication Date

10-2015

Publication Source

Optics Letters

Abstract

A transmission-type metasurface composed of carefully designed rectangular slot antennas for the generation of vectorial optical fields is proposed and demonstrated. Acting as local linear polarizers, these slot antennas enable the spatial modulation of optical fields in amplitude, phase, and polarization for the cross-polarized component of the scattered field. As an illustration, a metasurface capable of forming a radially polarized scattered field with specific vectorial beam patterns with appropriate excitation at normal incidence is designed, fabricated, and tested. The radially polarized scattered field is designed to be further tightly focused by a high numerical aperture objective lens in order to obtain a uniform longitudinally polarized optical needle field along the propagation direction. Characterization experiments demonstrate that its overall extinction ratio satisfies the amplitude modulation requirement, and a corresponding π phase modulation is realized as proposed.

Inclusive pages

4711-4714

ISBN/ISSN

0146-9592

Comments

Permission documentation is on file.

Publisher

Optical Society of America

Volume

40

Issue

20

Peer Reviewed

yes

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