{
  "annotation_id": "e5b8066c-d404-41b8-b68a-75ad45e79395",
  "date_created": "2026-03-02T18:00:57.341000Z",
  "date_modified": "2026-03-02T18:00:57.341000Z",
  "file_hash": "02344ff4738f6166d80a27b254c2f94883f1160be47d770130a3531180067633",
  "private": false,
  "record": {
    "abstract": "We have constructed an achromatic half wave plate (AHWP) suitable for the\nmillimeter wavelength band. The AHWP was made from a stack of three sapphire\na-cut birefringent plates with the optical axes of the middle plate rotated by\n50.5 degrees with respect to the aligned axes of the other plates. The measured\nmodulation efficiency of the AHWP at 110 GHz was $96 \\pm 1.5$%. In contrast,\nthe modulation efficiency of a single sapphire plate of the same thickness was\n$43 \\pm 4$%. Both results are in close agreement with theoretical predictions.\nThe modulation efficiency of the AHWP was constant as a function of incidence\nangles between 0 and 15 degrees. We discuss design parameters of an AHWP in the\ncontext of astrophysical broad band polarimetry at the millimeter wavelength\nband.",
    "arxiv_id": "physics/0503122",
    "authors": [
      "S. Hanany",
      "J. Hubmayr",
      "B. R. Johnson",
      "T. Matsumura",
      "P. Oxley",
      "M. Thibodeau"
    ],
    "categories": [
      "physics.optics",
      "astro-ph"
    ],
    "doi": "10.1364/AO.44.004666",
    "title": "A Millimeter-Wave Achromatic Half Wave Plate",
    "url": "https://arxiv.org/abs/physics/0503122"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8016bedb-c86e-4ee3-9acd-b9a2d5755716",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}