{
  "abstract": "Hadamard-coded optical receivers typically rely on stable interference conditions, which can motivate active optical phase control. We investigate a fixed, intensity-only decoder that embeds four populated modes in an eight-mode interferometer and provides six complementary trigonometric observables through simultaneous power measurements. An analytic transition decoder uses the resulting sign-change patterns without continuous optical phase stabilization. The receiver's intensity-to-observable map is inverted exactly, and an identifiability analysis characterizes exceptional phase configurations and conditional noise sensitivity. An ideal, equal-photon-budget comparison with conventional four-port Hadamard decoding illustrates the potential value of the additional outputs without implying an unconditional advantage. Measurements on programmable photonic processors give 96.19% accuracy for the analytical decoding experiment; a complementary machine-learning analysis reports 98.31% on a held-out experimental trace. These results demonstrate an intensity-only, phase-aware approach to differential Hadamard decoding under the tested conditions, while larger codebooks and hardware-level energy benefits remain topics for future investigation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.29797",
  "author_total": 3,
  "authors": [
    {
      "name": "Gökhan Elmas"
    },
    {
      "name": "Igor A Litvin"
    },
    {
      "name": "Janis Nötzel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1zmncxy7sw2tv.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.29797",
  "fulltext_url": null,
  "id": "1zmncxy7sw2tv",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.29797",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.optics"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7223206171",
  "pdf_url": "https://arxiv.org/pdf/2610.29797",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1zmncxy7sw2tv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:19Z",
      "native_id": "2610.29797",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.29797"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Passive Phase-Aware Hadamard Decoding: Analytical and Machine-Learning Approaches",
  "title_text": "Passive Phase-Aware Hadamard Decoding: Analytical and Machine-Learning Approaches",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:19Z",
  "url": "https://research.draconitic.com/paper/1zmncxy7sw2tv",
  "venue": "arXiv",
  "versions": []
}