Abstract

Topology optimization is a powerful iterative inverse design technique in metasurface engineering and can transform an initial layout into a high-performance device. With this method, devices are optimized within a local design phase space, making the identification of suitable initial geometries essential. In this Letter, we examine the impact of initial geometric layout on the performance of large-angle (75 deg) topology-optimized metagrating deflectors. We find that when conventional metasurface designs based on dielectric nanoposts are used as initial layouts for topology optimization, the final devices have efficiencies around 65%. In contrast, when random initial layouts are used, the final devices have ultra-high efficiencies that can reach 94%. Our numerical experiments suggest that device topologies based on conventional metasurface designs may not be suitable to produce ultra-high-efficiency, large-angle metasurfaces. Rather, initial geometric layouts with non-trivial topologies and shapes are required.

© 2017 Optical Society of America

Analysis of material selection on dielectric metasurface performance

Jianji Yang and Jonathan A. Fan
Opt. Express 25(20) 23899-23909 (2017)

Topology-optimized catenary-like metasurface for wide-angle and high-efficiency deflection: from a discrete to continuous geometric phase

Mingfeng Xu, Mingbo Pu, Di Sang, Yuhan Zheng, Xiong Li, Xiaoliang Ma, Yinghui Guo, Renyan Zhang, and Xiangang Luo
Opt. Express 29(7) 10181-10191 (2021)

Robust design of topology-optimized metasurfaces

Evan W. Wang, David Sell, Thaibao Phan, and Jonathan A. Fan
Opt. Mater. Express 9(2) 469-482 (2019)

Freestanding dielectric nanohole array metasurface for mid-infrared wavelength applications

Jun Rong Ong, Hong Son Chu, Valerian Hongjie Chen, Alexander Yutong Zhu, and Patrice Genevet
Opt. Lett. 42(13) 2639-2642 (2017)

Low-index second-order metagratings for large-angle anomalous reflection

Xipu Dong, Jierong Cheng, Fei Fan, and Shengjiang Chang
Opt. Lett. 44(4) 939-942 (2019)