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arXiv · 1905.09213

High-NA Achromatic Metalenses by Inverse Design

Haejun Chung·Owen D. Miller
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Abstract

We use inverse design to discover metalens structures that exhibit broadband, achromatic focusing across low, moderate, and high numerical apertures. We show that standard unit-cell approaches cannot achieve high-efficiency high-NA focusing, even at a single frequency, due to the incompleteness of the unit-cell basis, and we provide computational upper bounds on their maximum efficiencies. At low NA, our devices exhibit the highest theoretical efficiencies to date. At high NA -- of 0.9 with translation-invariant films and of 0.99 with "freeform" structures -- our designs are the first to exhibit achromatic high-NA focusing.

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Haejun Chung, Owen D. Miller. 2019-05-22. High-NA Achromatic Metalenses by Inverse Design. https://doi.org/10.1364/oe.385440

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