{
  "annotation_id": "25d341a5-8b78-4603-aa65-a3a1a47c989b",
  "date_created": "2026-03-02T18:01:10.915000Z",
  "date_modified": "2026-03-02T18:01:10.915000Z",
  "file_hash": "c1c65ecd215f5a168ea103f7cd69d04d1092fcdf661eebb450e6bd07ff4aef2a",
  "private": false,
  "record": {
    "abstract": "The identification of the refractive index and wave vector for general\n(possibly active) linear, isotropic, homogeneous, and non-spatially dispersive\nmedia is discussed. Correct conditions for negative refraction necessarily\ninclude the global properties of the permittivity and permeability functions\n$\\epsilon=\\epsilon(\\omega)$ and $\\mu=\\mu(\\omega)$. On the other hand, a\nnecessary and sufficient condition for left-handedness can be identified at a\nsingle frequency ($\\re\\epsilon/|\\epsilon|+\\re\\mu/|\\mu|\u003c0$). At oblique\nincidence to semi-infinite, active media it is explained that the wave vector\ngenerally loses its usual interpretation for real frequencies.",
    "arxiv_id": "physics/0607104",
    "authors": [
      "Johannes Skaar"
    ],
    "categories": [
      "physics.optics"
    ],
    "doi": "10.1364/OL.31.003372",
    "journal_ref": "Optics Letters 31, pp. 3372-3374 (2006)",
    "title": "On resolving the refractive index and the wave vector",
    "url": "https://arxiv.org/abs/physics/0607104"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "5559fe49-587e-47ec-ac10-e98d6b162f65",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}