{
  "abstract": "Compact ultrafast laser combs around the 2 $μ$m atmospheric transmission window are of growing interest for direct spectroscopy and as drivers for nonlinear conversion to otherwise hard-to-reach spectral regions. Dual-comb systems in this region remain very scarce: existing implementations rely mostly on nonlinear conversion, resulting in complex systems with poor conversion efficiency and overall low average and peak power. In this paper, we report on a watt-level dual-comb laser directly emitting at 2.1 $μ$m. The system is based on a single-cavity, soft-aperture Kerr-lens mode-locked (KLM) laser using a broadband holmium (Ho)-doped CaAlGdO$_4$ (CALGO) gain crystal. The laser delivers a total output power exceeding 2 W (1 W per comb) with a sub-100-fs pulse duration (50 nm bandwidth) at a repetition rate of 96.5 MHz, corresponding to a pulse energy of 10 nJ and a peak power of 100 kW per comb. To assess the source's potential for future spectroscopic applications, we characterize the free-running dual comb in detail for frequency stability, phase noise, and relative intensity noise (RIN), and benchmark the achievable spectral resolution by measuring spectral modulations imposed by Fabry-Pérot etalons. Our system combines the compactness, high efficiency, and passive mutual coherence of a single-cavity oscillator with watt-level average power at 2.1 $μ$m, making it a promising source for environmental sensing in the atmospheric transmission window, or as a driver for nonlinear frequency conversion, for example, to the MIR and THz regions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.21766",
  "author_total": 7,
  "authors": [
    {
      "name": "Mykyta Redkin"
    },
    {
      "name": "Yicheng Wang"
    },
    {
      "name": "Marcel van Delden"
    },
    {
      "name": "Robin Löscher"
    },
    {
      "name": "Oliver Nagy"
    },
    {
      "name": "Sergei Tomilov"
    },
    {
      "name": "Clara J. Saraceno"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/drnqbjvaxy3ey.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.21766",
  "fulltext_url": null,
  "id": "drnqbjvaxy3ey",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.21766",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.optics"
    ],
    [
      "openalex",
      "3107|Advanced Fiber Laser Technologies"
    ]
  ],
  "openalex": "W7222467301",
  "pdf_url": "https://arxiv.org/pdf/2610.21766",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/drnqbjvaxy3ey.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:50Z",
      "native_id": "2610.21766",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.21766"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Watt-level single-cavity dual-comb laser at 2.1 $μ$m wavelength",
  "title_text": "Watt-level single-cavity dual-comb laser at 2.1 μm wavelength",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:50Z",
  "url": "https://research.draconitic.com/paper/drnqbjvaxy3ey",
  "venue": "arXiv",
  "versions": []
}