{
  "annotation_id": "ed935c4c-8245-481b-a072-7cf053fc5a7c",
  "date_created": "2026-03-02T18:02:50.894000Z",
  "date_modified": "2026-03-02T18:02:50.894000Z",
  "file_hash": "0a82440b7954fbc717ae00cdb2a841f5af4ddc0ff8fc332c834b39060b0993d2",
  "private": false,
  "record": {
    "abstract": "We present a model of optical communication system for high-bit-rate data\ntransmission in the nonreturn-to-zero (NRZ) format over transoceanic distance.\nThe system operates in a small group velocity dispersion regime, and the model\nequation is given by the Whitham equations describing the slow modulation of\nmulti-phase wavetrains of the (defocusing) nonlinear Schr\\\"odinger (NLS)\nequation. The model equation is of hyperbolic type, and certain initial NRZ\npulse with phase modulation develops a shock. We then show how one can obtain a\nglobal solution by choosing an appropriate Riemann surface on which the Whitham\nequation is defined. The present analysis may be interpreted as an alternative\nto the method of inverse scattering transformation for the NLS solitons. We\nalso discuss wavelength-division-multiplexing (WDM) in the NRZ format by using\nthe Whitham equation for a coupled NLS equation, and show that there exists a\nhydro-dynamic-type instability between channels.",
    "arxiv_id": "solv-int/9709012",
    "authors": [
      "Yuji Kodama"
    ],
    "categories": [
      "solv-int",
      "nlin.SI"
    ],
    "title": "The Whitham Equations for Optical Communications: Mathematical Theory of   NRZ",
    "url": "https://arxiv.org/abs/solv-int/9709012"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "40072416-86a6-4dbb-b3e0-ddbadc10da18",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}