{
  "abstract": "Photons from ultrastable lasers can remain coherent over distances approaching the Earth-Sun separation, enabling optical clocks projected to lose less than one second over the age of the Universe. Yet characterizing these photons poses an identifiability problem: a two-laser heterodyne measurement produces a single beatnote linewidth that conflates contributions from both lasers. For more than half a century, the standard solution has been the three-cornered-hat (TCH) method, which requires three independent ultrastable lasers. Here we derive the mathematical form and elucidate the physical origin of asymmetric beatnote-linewidth distributions arising from finite photon wave trains, a long-observed feature not captured by canonical Gaussian or Lorentzian statistics. This finding accurately recovers two linewidths hidden in laser beatnote statistics without a third laser. The framework consistently captures the observed coherence-length and coherence-time statistics of photons, while comparison with TCH measurements confirms the quantitative validity of the extracted individual linewidths across five independent ultrastable-laser datasets spanning nearly two orders of magnitude. Most notably, the method resolves the 7.8-mHz linewidth of a cryogenic silicon-cavity laser beating with a broader laser. This transformative function of beatnote-linewidth distributions, together with the resulting method, could fundamentally advance optical clocks and precision metrology.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.36592",
  "author_total": 15,
  "authors": [
    {
      "name": "Jingming Chen"
    },
    {
      "name": "Yuanchen Qi"
    },
    {
      "name": "Yuzheng Pang"
    },
    {
      "name": "Jie Miao"
    },
    {
      "name": "Congyu Wang"
    },
    {
      "name": "Yuan Yao"
    },
    {
      "name": "Zhi-Ang Chen"
    },
    {
      "name": "Run-Qi Lei"
    },
    {
      "name": "Zheyi Ge"
    },
    {
      "name": "Yanyi Jiang"
    },
    {
      "name": "Xibo Zhang"
    },
    {
      "name": "Xiaopeng Xie"
    },
    {
      "name": "Jianjun Wu"
    },
    {
      "name": "Duo Pan"
    },
    {
      "name": "Jingbiao Chen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/aszw9w5t4jdab.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.36592",
  "fulltext_url": null,
  "id": "aszw9w5t4jdab",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.36592",
  "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",
      "3107|Advanced Frequency and Time Standards"
    ]
  ],
  "openalex": "W7214886121",
  "pdf_url": "https://arxiv.org/pdf/2609.36592",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/aszw9w5t4jdab.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.36592",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.36592"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Accurate recovery of the two linewidths hidden in laser beatnote statistics",
  "title_text": "Accurate recovery of the two linewidths hidden in laser beatnote statistics",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/aszw9w5t4jdab",
  "venue": "arXiv",
  "versions": []
}