{
  "abstract": "We propose a structure-aware, hierarchical locally periodic eigenmode expansion (HLP-EME) framework for efficiently simulating millimeter-scale integrated Bragg gratings (IBGs) with complex modulation on silicon-on-insulator platforms. HLP-EME discretizes continuously varying grating parameter profiles into piecewise-constant blocks and exploits the resulting local periodicity of the physical grating structure by reusing the S-matrix of a representative period within each block. This strategy reduces full-device simulation times for millimeter-scale IBGs to a few minutes, providing a speedup exceeding three orders of magnitude over conventional 3D-FDTD simulations. The method accommodates diverse IBG configurations, including intra-mode gratings, mode-converting multimode gratings and grating-assisted contra-directional couplers. Experimental results validate the predicted reflection spectra of several complex-modulated IBGs and the reflection phase response of one representative design. The framework is further extended to curved waveguides and successfully captures curvature-induced spectral distortions in millimeter-long, Gaussian-apodized spiral IBGs. Combining full-vectorial modeling with high computational efficiency, HLP-EME provides a powerful tool for designing and optimizing long, complex IBG-based photonic devices.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.30224",
  "author_total": 5,
  "authors": [
    {
      "name": "Rui Cheng"
    },
    {
      "name": "Jia Meng"
    },
    {
      "name": "Ping Yu"
    },
    {
      "name": "Jihao Wang"
    },
    {
      "name": "Zikun Xie"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c166e7yk1sqxe.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.30224",
  "fulltext_url": null,
  "id": "c166e7yk1sqxe",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.30224",
  "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.optics"
    ],
    [
      "openalex",
      "2208|Photonic and Optical Devices"
    ]
  ],
  "openalex": "W7214285600",
  "pdf_url": "https://arxiv.org/pdf/2609.30224",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/c166e7yk1sqxe.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.30224",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.30224"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Efficient simulation of millimeter-scale complex-modulated integrated Bragg gratings via hierarchical locally periodic eigenmode expansion",
  "title_text": "Efficient simulation of millimeter-scale complex-modulated integrated Bragg gratings via hierarchical locally periodic eigenmode expansion",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/c166e7yk1sqxe",
  "venue": "arXiv",
  "versions": []
}