{
  "abstract": "A new approach of silicon-lithium niobate (Si-LN) grating couplers (GCs) with a fully-etched structure is proposed. The coupling strength is engineered through subwavelength structures, allowing improved directionality. The adjoint-based inverse design method is simultaneously adopted to achieve efficient coupling between photonic circuits and fibers. Considering the birefringence of LN, the proposed Si-LN GCs are optimized and fabricated for TE mode along the crystallographic Z and Y directions. The experimentally measured coupling efficiencies are -3.3 dB and -3.9 dB along the crystallographic Z and Y directions, respectively. The measured 3-dB bandwidths are broader than 54 nm and the back reflections can be suppressed down to -15 dB over 50 nm for both directions. The proposed Si-LN GCs are realized by only single-step Si etching, offering a practical solution for fast device prototyping in Si-LN photonic integrated circuits.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.25839",
  "author_total": 4,
  "authors": [
    {
      "name": "Jing Wang"
    },
    {
      "name": "Yang Liu"
    },
    {
      "name": "Shitong Su"
    },
    {
      "name": "Weiwen Zou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7svgjnj29b7jz.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.25839",
  "fulltext_url": null,
  "id": "7svgjnj29b7jz",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.25839",
  "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": "W7223027386",
  "pdf_url": "https://arxiv.org/pdf/2610.25839",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7svgjnj29b7jz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.25839",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.25839"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "High-Efficiency Silicon-Lithium Niobate Grating Coupler enabled by Fully-Etched Subwavelength Structures",
  "title_text": "High-Efficiency Silicon-Lithium Niobate Grating Coupler enabled by Fully-Etched Subwavelength Structures",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/7svgjnj29b7jz",
  "venue": "arXiv",
  "versions": []
}