{
  "annotation_id": "22122bca-b8c9-49ef-941c-c46d5833c84d",
  "date_created": "2026-03-02T18:01:10.317000Z",
  "date_modified": "2026-03-02T18:01:10.317000Z",
  "file_hash": "bfadb001fba132270817d28ebd7b27dc2199c26e4c4864f918b4aee606c4e0b8",
  "private": false,
  "record": {
    "abstract": "Laser interferometry is an extensively used diagnostic for plasma\nexperiments. Existing plasma interferometers are designed on the presumption\nthat the scene and reference beam path lengths have to be equal, a requirement\nthat is costly in both the number of optical components and the alignment\ncomplexity. It is shown here that having equal path lengths is not necessary -\ninstead what is required is that the path length difference be an even multiple\nof the laser cavity length. This assertion has been verified in a heterodyne\nlaser interferometer that measures typical line-average densities of $\\sim\n10^{21}/\\textrm{m}^2$ with an error of $\\sim 10^{19}/\\textrm{m}^2$.",
    "arxiv_id": "physics/0608082",
    "authors": [
      "Deepak Kumar",
      "Paul M. Bellan"
    ],
    "categories": [
      "physics.plasm-ph"
    ],
    "doi": "10.1063/1.2336769",
    "title": "Heterodyne interferometer with unequal path lengths",
    "url": "https://arxiv.org/abs/physics/0608082"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "04d4f0fa-adcc-45a7-ba2a-8efebe784b6b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}