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Multifunctional 25D metastructures enabled by adjoint optimization

Mansouree, Mahdad and Kwon, Hyounghan and Arbabi, Ehsan and McClung, Andrew and Faraon, Andrei and Arbabi, Amir (2020) Multifunctional 25D metastructures enabled by adjoint optimization. Optica, 7 (1). pp. 77-84. ISSN 2334-2536.

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Optical metasurfaces are two-dimensional arrays of meta-atoms that modify different characteristics of light such as phase, amplitude, and polarization. One intriguing feature that distinguishes them from conventional optical components is their multifunctional capability. However, multifunctional metasurfaces with efficiencies approaching those of their single-functional counterparts require more degrees of freedom. Here we show that 2.5D metastructures, which are stacked layers of interacting metasurface layers, provide sufficient degrees of freedom to implement efficient multifunctional devices. The large number of design parameters and their intricate intercoupling make the design of multifunctional 2.5D metastructures a complex task, and unit-cell approaches to metasurface design produce suboptimal devices. We address this issue by designing 2.5D metastructures using the adjoint optimization technique. Instead of designing unit cells individually, our technique considers the structure as a whole, accurately accounting for inter-post and inter-layer coupling. As proof of concept, we experimentally demonstrate a double-wavelength metastructure, designed using adjoint optimization, that has significantly higher efficiencies than a similar device designed with a simplified approach conventionally used in metasurface design. The 2.5D metastructure architecture empowered by the optimization-based design technique is a general platform for realizing high-performance multifunctional components and systems.

Item Type:Article
Related URLs:
URLURL TypeDescription Information
Arbabi, Ehsan0000-0002-5328-3863
McClung, Andrew0000-0001-6995-3289
Faraon, Andrei0000-0002-8141-391X
Arbabi, Amir0000-0001-8831-7552
Additional Information:© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. Received 6 August 2019; revised 2 December 2019; accepted 10 December 2019 (Doc. ID 374787); published 17 January 2020. Funding: Defense Advanced Research Projects Agency; Samsung Advanced Institute of Technology.
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Samsung Advanced Institute of TechnologyUNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:20200130-150837293
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Official Citation:Mahdad Mansouree, Hyounghan Kwon, Ehsan Arbabi, Andrew McClung, Andrei Faraon, and Amir Arbabi, "Multifunctional 2.5D metastructures enabled by adjoint optimization," Optica 7, 77-84 (2020)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:101012
Deposited By: Tony Diaz
Deposited On:30 Jan 2020 23:17
Last Modified:30 Jan 2020 23:17

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