TY - JOUR

T1 - Time-Domain Topology Optimization of Arbitrary Dispersive Materials for Broadband 3D Nanophotonics Inverse Design

AU - Gedeon, Johannes

AU - Hassan, Emadeldeen

AU - Calà Lesina, Antonio

N1 - Funding Information: We acknowledge the computing time granted by the Resource Allocation Board and provided on the supercomputer Lise and Emmy at NHR@ZIB and NHR@Göttingen as part of the NHR infrastructure. The calculations for this research were conducted with computing resources under the project nip00059. We acknowledge the central computing cluster operated by Leibniz University IT Services (LUIS) at the Leibniz University Hannover. We acknowledge the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453), and under the Project CA 2763/2-1 (Project ID 527470210). A.C.L. acknowledges the German Federal Ministry of Education and Research (BMBF) under the Tenure-Track Program. The publication of this article was funded by the Open Access Publishing Fund of the Leibniz University Hannover. Funding Information: We acknowledge the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453), and under the Project CA 2763/2-1 (Project ID 527470210). A.C.L. acknowledges the German Federal Ministry of Education and Research (BMBF) under the Tenure-Track Program. The publication of this article was funded by the Open Access Publishing Fund of the Leibniz University Hannover.

PY - 2023/11/15

Y1 - 2023/11/15

N2 - In the last decades, nanostructures have unlocked myriads of functionalities in nanophotonics by engineering light-matter interaction beyond what is possible with conventional bulk optics. The space of parameters available for design is practically unlimited due to the large variety of optical materials and nanofabrication techniques. Thus, computational approaches are necessary to efficiently search for the optimal solutions. In this paper, we enable the free-form inverse design in 3D of linear optical materials with arbitrary dispersion and anisotropy. This is achieved by (1) deriving an analytical adjoint scheme based on the complex-conjugate pole-residue pair model in the time domain and (2) its implementation in a parallel finite-difference time-domain framework with a topology optimization routine, efficiently running on high-performance computing systems. Our method is tested on the design problem of field confinement using dispersive nanostructures. The obtained designs satisfy the fundamental curiosity of how free-form metallic and dielectric nanostructures perform when optimized in 3D, also in comparison to fabrication-constrained designs. Unconventional free-form designs revealed by computational methods, although may be challenging or unfeasible to realize with current technology, bring new insights into how light can more efficiently interact with nanostructures and provide new ideas for forward design.

AB - In the last decades, nanostructures have unlocked myriads of functionalities in nanophotonics by engineering light-matter interaction beyond what is possible with conventional bulk optics. The space of parameters available for design is practically unlimited due to the large variety of optical materials and nanofabrication techniques. Thus, computational approaches are necessary to efficiently search for the optimal solutions. In this paper, we enable the free-form inverse design in 3D of linear optical materials with arbitrary dispersion and anisotropy. This is achieved by (1) deriving an analytical adjoint scheme based on the complex-conjugate pole-residue pair model in the time domain and (2) its implementation in a parallel finite-difference time-domain framework with a topology optimization routine, efficiently running on high-performance computing systems. Our method is tested on the design problem of field confinement using dispersive nanostructures. The obtained designs satisfy the fundamental curiosity of how free-form metallic and dielectric nanostructures perform when optimized in 3D, also in comparison to fabrication-constrained designs. Unconventional free-form designs revealed by computational methods, although may be challenging or unfeasible to realize with current technology, bring new insights into how light can more efficiently interact with nanostructures and provide new ideas for forward design.

KW - adjoint method

KW - FDTD method

KW - inverse design

KW - optical dispersion

KW - time domain

KW - topology optimization

UR - http://www.scopus.com/inward/record.url?scp=85178058762&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2305.00234

DO - 10.48550/arXiv.2305.00234

M3 - Article

AN - SCOPUS:85178058762

VL - 10

SP - 3875

EP - 3887

JO - ACS PHOTONICS

JF - ACS PHOTONICS

SN - 2330-4022

IS - 11

ER -