Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topology optimization of freeform large-area metasurfaces   We demonstrate optimization of optical metasurfaces over $10^5$--$10^6$
degrees of freedom in two and three dimensions, 100--1000+ wavelengths
($\lambda$) in diameter, with 100+ parameters per $\lambda^2$. In particular,
we show how topology optimization, with one degree of freedom per
high-resolution "pixel," can be extended to large areas with the help of a
locally periodic approximation that was previously only used for a few
parameters per $\lambda^2$. In this way, we can computationally discover
completely unexpected metasurface designs for challenging multi-frequency,
multi-angle problems, including designs for fully coupled multi-layer
structures with arbitrary per-layer patterns. Unlike typical metasurface
designs based on subwavelength unit cells, our approach can discover both sub-
and supra-wavelength patterns and can obtain both the near and far fields.

14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys