# How Corning Invented Modern Fiber Optic Cables > 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. - **Patent:** US 3711262 - **Original title:** Method of producing optical waveguide fibers - **Owner:** Corning Glass Works - **Granted:** 1973 - **Status:** Public domain (expired) - **Times cited:** 86 - **Field:** telecommunications, materials, mechanical ## 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. ## The clever bit The innovation was the realization that you could create a solid fiber by collapsing a tube, ensuring the core and cladding were perfectly aligned and fused during the drawing process. ## Real-world examples 1. Undersea transoceanic internet cables 2. Fiber-to-the-home (FTTH) broadband connections 3. High-speed enterprise data center networking ## Why it matters This patent represents the birth of the modern telecommunications backbone. By demonstrating a viable way to produce low-loss glass fibers, it enabled the transition from copper wires to light-based data transmission, which now carries the vast majority of global internet traffic. ## Frequently asked questions ### What does How Corning Invented Modern Fiber Optic Cables cover? 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. ### Who owns patent US 3711262? Corning Glass Works owns this patent, granted in 1973. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 3711262 cited by? This patent has been cited by 86 later patents that build on its ideas. ### What problem does this patent solve? This patent represents the birth of the modern telecommunications backbone. By demonstrating a viable way to produce low-loss glass fibers, it enabled the transition from copper wires to light-based data transmission, which now carries the vast majority of global internet traffic. ### What does this patent NOT cover? Does not cover the chemical vapor deposition processes (like MCVD) that later became the industry standard for mass production. **Full plain-English explainer:** https://patentbrief.org/patent/us/3711262/optical-fiber-waveguide **Original patent:** https://patents.google.com/patent/US3711262 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [Connecting Different Types of Fiber Optic Cables with an Adapter](https://patentbrief.org/patent/us/12517303/optical-waveguide-adapter-assembly) — This patent describes a special adapter that smoothly connects a traditional solid core optical fiber to a newer hollow core optical fiber by carefully changing the light's beam size as it passes between them. - [How a Special Fiber Stub Cleans Up Light Signals](https://patentbrief.org/patent/us/7267494/fiber-stub-for-cladding-mode-coupling-reduction) — This patent describes a short piece of optical fiber, called a fiber stub, designed to prevent unwanted light from escaping the fiber's core and interfering with data transmission by using a ferrule with a specific optical property. - [How a Multi-Core Optical Fiber Reduces Signal Interference](https://patentbrief.org/patent/us/11480727/multi-core-optical-fiber) — This patent describes a multi-core optical fiber designed for short-distance data transmission, featuring a specific linear arrangement of at least four cores with alternating designs to minimize signal leakage between them. - [Routing Light Between Fiber Cores Using Special Reflectors](https://patentbrief.org/patent/us/11646794/fiber-optic-connectors-and-connectorized-fiber-optic-cables-that-include-integra) — This patent describes a fiber optic connector that uses tiny, specially designed reflectors called holographic Bragg gratings to precisely guide light signals from one optical fiber to multiple other fibers, even separating different colors (wavelengths) of light. - [How Glass Fibers Are Spun for Insulation](https://patentbrief.org/patent/us/2133235/fiberglass-glass-wool-slayter) — A 1933 invention by Games Slayter that describes the process of melting glass and blasting it into fine, flexible fibers to create insulation.