{
  "abstract": "Gradient-based design of large optical surfaces hits a memory wall: a stored-history time-domain adjoint needs $24N_t$ bytes per cell for $N_t$ steps, and every field update is bound by memory bandwidth. Here we present a validated framework that removes this wall and makes globally optimized freeform meta-optics practical. Its finite-difference time-domain adjoint reconstructs interior fields backwards from two recorded planes, so volume memory no longer grows with $N_t$, and fused kernels raise memory-bandwidth use on an H200 GPU from 6.4% to a remarkable 56% of peak. Overlapping tiles, coupled by angular-spectrum propagation and distributed over GPUs, keep tile memory independent of the aperture. Within hours on one GPU node, we optimize, against one global objective, every density variable of single-layer metasurfaces 100 to 200 $μ$m across, and design a nine-wavelength lens, a color hologram and a polarization-switched hologram. Confirmed by an independent solver within 1.6%, they substantially outperform meta-atom designs, reaching 1.64, 1.65 and 1.24 times their objectives.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.30039",
  "author_total": 2,
  "authors": [
    {
      "name": "Hyoseok Park"
    },
    {
      "name": "Yeonsang Park"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/28eqsava6s6h8.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.30039",
  "fulltext_url": null,
  "id": "28eqsava6s6h8",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.30039",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.comp-ph"
    ],
    [
      "arxiv",
      "physics.optics"
    ],
    [
      "openalex",
      "2208|Electromagnetic Simulation and Numerical Methods"
    ]
  ],
  "openalex": "W7214390511",
  "pdf_url": "https://arxiv.org/pdf/2609.30039",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/28eqsava6s6h8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:22Z",
      "native_id": "2609.30039",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.30039"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.comp-ph",
      "subfield": "computational"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Inverse design of large-scale freeform meta-optics by breaking the memory wall of full-wave simulation",
  "title_text": "Inverse design of large-scale freeform meta-optics by breaking the memory wall of full-wave simulation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:22Z",
  "url": "https://research.draconitic.com/paper/28eqsava6s6h8",
  "venue": "arXiv",
  "versions": []
}