Multifunctional 25D metastructures enabled by adjoint optimization
Abstract
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.
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.Attached Files
Published - optica-7-1-77.pdf
Supplemental Material - 4320487.pdf
Files
Name | Size | Download all |
---|---|---|
md5:345a6a526ec638e4c8481f1793a58144
|
4.2 MB | Preview Download |
md5:868b94424832d93e9158bbfecf1f36dc
|
5.2 MB | Preview Download |
Additional details
- Eprint ID
- 101012
- Resolver ID
- CaltechAUTHORS:20200130-150837293
- Defense Advanced Research Projects Agency (DARPA)
- Samsung Advanced Institute of Technology
- Created
-
2020-01-30Created from EPrint's datestamp field
- Updated
-
2023-06-01Created from EPrint's last_modified field