{
  "annotation_id": "ce682024-ec3e-4f5a-9082-0193c37f7263",
  "date_created": "2026-03-02T18:02:16.487000Z",
  "date_modified": "2026-03-02T18:02:16.487000Z",
  "file_hash": "bc3877b0fc1db614668b0d4e203425cd94d10100a540e1e9e9569d26c3cc724a",
  "private": false,
  "record": {
    "abstract": "The aim of this review paper is to enlighten some recent progresses in\nquantum optical metrology in the part of quantum efficiency measurements of\nphoto-detectors performed with bi-photon states. The intrinsic correlated\nnature of entangled photons from Spontaneous Parametric Down Conversion\nphenomenon has opened wide horizons to a new approach for the absolute\nmeasurement of photo-detector quantum efficiency, outgoing the requirement for\nconventional standards of optical radiation; in particular the simultaneous\nfeature of the creation of conjugated photons led to a well known technique of\ncoincidence measurement, deeply understood and implemented for standard uses.\nOn the other hand, based on manipulation of entanglement developed for Quantum\nInformation protocols implementations, a new method has been proposed for\nquantum efficiency measurement, exploiting polarisation entanglement in\naddition to energy-momentum and time ones, that is based on conditioned\npolarisation state manipulation. In this review, after a general discussion on\nabsolute photo-detector calibration, we compare these different methods, in\norder to give an accurate operational sketch of the absolute quantum efficiency\nmeasurement state of the art.",
    "arxiv_id": "quant-ph/0505227",
    "authors": [
      "G. Brida",
      "M. Genovese",
      "M. Gramegna"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1002/lapl.200510077",
    "journal_ref": "Laser Physics Letters 3 (2006) 115",
    "title": "Twin-photon techniques for photo-detector calibration",
    "url": "https://arxiv.org/abs/quant-ph/0505227"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "996d6129-0f7c-428a-a393-e6dfa17c14ca",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}