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arXiv · 2501.07979

Scalable freeform optimization of wide-aperture 3D metalenses by zoned discrete axisymmetry

Mengdi Sun·Ata Shakeri·Arvin Keshvari·Dimitrios Giannakopoulos·Qing Wang·Wei Ting Chen·Steven G. Johnson·Zin Lin
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Abstract

We introduce a novel framework for design and optimization of 3D freeform metalenses that attains nearly linear scaling of computational cost with diameter, by breaking the lens into a sequence of radial "zones" with $n$-fold discrete axisymmetry, where $n$ increases with radius. This allows vastly more design freedom than imposing continuous axisymmetry, while avoiding the compromises of the locally periodic approximation (LPA) or scalar diffraction theory. Using a GPU-accelerated finite-difference time-domain (FDTD) solver in cylindrical coordinates, we perform full-wave simulation and topology optimization within each supra-wavelength zone. We validate our approach by designing millimeter and centimeter-scale, poly-achromatic, 3D freeform metalenses which outperform the state of the art. By demonstrating the scalability and resulting optical performance enabled by our "zoned discrete axisymmetry" (ZDA) and supra-wavelength domain decomposition, we highlight the potential of our framework to advance large-scale meta-optics and next-generation photonic technologies.

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Mengdi Sun, Ata Shakeri, Arvin Keshvari, Dimitrios Giannakopoulos, Qing Wang, Wei Ting Chen, Steven G. Johnson, Zin Lin. 2025-01-14. Scalable freeform optimization of wide-aperture 3D metalenses by zoned discrete axisymmetry. https://doi.org/10.1021/acsphotonics.5c00505

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