{
  "annotation_id": "aeb235cc-d05d-4a26-b14f-a7a3ea18855b",
  "date_created": "2026-03-02T18:00:32.594000Z",
  "date_modified": "2026-03-02T18:00:32.594000Z",
  "file_hash": "58ade3b5eaa4f54ae8b1bdb9ef3b7a3fb5f9417872d53999cb25ff61cb85639c",
  "private": false,
  "record": {
    "abstract": "The frequency of the Calcium ^3P_1--^1S_0 intercombination line at 657 nm is\nphase-coherently measured in terms of the output of a primary cesium frequency\nstandard using an optical frequency comb generator comprising a sub-10 fs\nKerr-lens mode-locked Ti:Sapphire laser and an external microstructure fiber\nfor self-phase-modulation. The measured frequency of \\nu_Ca = 455 986 240 494\n276 Hz agrees within its relative uncertainty of 4 10^-13 with the values\npreviously measured with a conceptually different harmonic frequency chain and\nwith the value recommended for the realization of the SI unit of length.",
    "arxiv_id": "physics/0010016",
    "authors": [
      "J. Stenger",
      "T. Binnewies",
      "G. Wilpers",
      "F. Riehle",
      "H. R. Telle",
      "J. K. Ranka",
      "R. S. Windeler",
      "A. J. Stentz"
    ],
    "categories": [
      "physics.optics"
    ],
    "doi": "10.1103/PhysRevA.63.021802",
    "title": "Phase-coherent frequency measurement of the Ca intercombination line at   657 nm with a Kerr-lens mode-locked femtosecond laser",
    "url": "https://arxiv.org/abs/physics/0010016"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "5823e1a1-7b6f-4f28-987f-750615b7aac5",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}