{
  "patent_number": "US 3711262",
  "country": "US",
  "title": "How Corning Invented Modern Fiber Optic Cables",
  "original_title": "Method of producing optical waveguide fibers",
  "summary": "A 1970 method for creating glass fibers that carry light over long distances by layering glass inside a tube and drawing it into a thin, solid strand.",
  "what_it_does": "The patent describes a process for manufacturing optical waveguides by depositing a thin film of glass with a specific refractive index onto the inner surface of a glass tube. This tube, which has a different refractive index, acts as the cladding. The combined structure is then heated and drawn, causing the tube to collapse inward and form a solid, thin fiber. This creates a core of high-purity glass surrounded by a cladding layer, which is the essential structure required to keep light trapped inside the fiber via total internal reflection.",
  "what_it_does_not_cover": [
    "Does not cover the chemical vapor deposition processes (like MCVD) that later became the industry standard for mass production.",
    "Does not cover the use of plastic or polymer-based optical fibers.",
    "Does not cover the specific electronic hardware used to transmit or receive the light signals.",
    "Does not cover fiber optic cables that do not use a core-cladding structure with differing refractive indices."
  ],
  "filed": "1970-05-11",
  "granted": "1973-01-16",
  "expires": "1990-05-11",
  "status": "expired",
  "holder": "Corning Glass Works",
  "holder_url": "https://patentbrief.org/company/corning-glass-works",
  "inventors": [
    {
      "name": "D Keck",
      "url": "https://patentbrief.org/inventor/d-keck"
    },
    {
      "name": "P Schultz",
      "url": "https://patentbrief.org/inventor/p-schultz"
    }
  ],
  "times_cited": 86,
  "tags": [
    "telecommunications",
    "materials",
    "mechanical"
  ],
  "abstract": "A METHOD OF PRODUCING AN OPTICAL WAVEGUIDE BY FIRST FORMING A FILM OF GLASS WITH A PRESELECTED INDEX OF REFRACTION ON THE INSIDE WALL OF A GLASS TUBE HAVING A DIFFERENT PRESELECTED INDEX OF REFRACTION. THIS GLASS TUBE AND GLASS FILM COMBINATION IS THEN DRAWN TO REDUCE THE CROSS-SECTIONAL AREA AND TO COLLAPSE THE FILM OF GLASS TO FORM A FIBER HAVING A SOLID CROSS-SECTIONAL AREA; THE CORE BEING FORMED FROM THE GLASS FILM, AND THE CLADDING BEING FORMED FROM THE GLASS TUBE.",
  "url": "https://patentbrief.org/patent/us/3711262/optical-fiber-waveguide",
  "markdown_url": "https://patentbrief.org/patent/us/3711262/optical-fiber-waveguide/md",
  "google_patents_url": "https://patents.google.com/patent/US3711262",
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}