{
  "abstract": "Dielectric multilayer mirrors are essential components in optical experiments using high-power lasers, where titanium dioxide (TiO$_2$) is widely employed as a high-refractive-index dielectric material. In this study, we investigate the nonlinear optical response of TiO$_2$ under intense ultrashort laser pulses using real-time first-principles electron-dynamics simulations based on time-dependent density functional theory (TDDFT). We reveal intensity-dependent absorption driven by multiphoton excitation and optically excited free carriers, and simulate the resulting electron-light coupled dynamics in TiO$_2$ nanofilms using a multiscale Maxwell-TDDFT framework. Direct evaluation of the reflected and transmitted fields shows reduced reflectance at high intensities ($I \\sim 10^{13}$ W/cm$^2$), demonstrating a pronounced nonlinear optical response. Furthermore, the optical response properties are compared among various stable and metastable crystalline phases of TiO$_2$-rutile, anatase, brookite, TiO$_2$-II, and TiO$_2$-B-as well as an amorphous supercell model. These results provide microscopic insight into intensity-dependent optical degradation in TiO$_2$-based dielectric optical components exposed to intense femtosecond laser fields.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.25129",
  "author_total": 4,
  "authors": [
    {
      "name": "Koya Shimaoka"
    },
    {
      "name": "Yusuke Kondo"
    },
    {
      "name": "Kazunori Shibata"
    },
    {
      "name": "Mitsuharu Uemoto"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/87sryamvq3c28.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.25129",
  "fulltext_url": null,
  "id": "87sryamvq3c28",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.25129",
  "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",
      "cond-mat.mtrl-sci"
    ],
    [
      "arxiv",
      "physics.optics"
    ],
    [
      "openalex",
      "3107|Laser-Matter Interactions and Applications"
    ]
  ],
  "openalex": "W7204476179",
  "pdf_url": "https://arxiv.org/pdf/2608.25129",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/87sryamvq3c28.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "2608.25129",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.25129"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "First-Principles Prediction of Nonlinear Optical Response in TiO$_2$ for High-Power Dielectric Mirror Applications",
  "title_text": "First-Principles Prediction of Nonlinear Optical Response in TiO_2 for High-Power Dielectric Mirror Applications",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/87sryamvq3c28",
  "venue": "arXiv",
  "versions": []
}