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.
Original patent title: “Method of producing optical waveguide fibers”
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. Granted to Corning Glass Works in 1973 with 86 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
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.
The gap
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.
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
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.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Undersea transoceanic internet cables
Fiber-to-the-home (FTTH) broadband connections
High-speed enterprise data center networking
Why it matters
The bigger picture
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.
Filed
May 11, 1970
Granted
January 16, 1973
Market context
Who's building on this
Companies in this space
Corning remains a dominant leader in the manufacturing of optical fiber. Companies like Prysmian Group and Sumitomo Electric have also built massive operations based on the fundamental principles of glass fiber drawing established here.
Market impact
This invention effectively launched the fiber optic industry, rendering long-distance copper telecommunications obsolete for high-bandwidth applications. It triggered a massive shift in infrastructure investment that continues to define how global data is moved today.
Claim 1 — Plain English
What this patent covers
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.
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.
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.
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
39/40
Highly cited
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$43K – $138K
Midpoint $86K · expired or expiring · industry ×2.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Keck, D., & Schultz, P. (1973). How Corning Invented Modern Fiber Optic Cables (U.S. Patent No. 3,711,262). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/3711262/optical-fiber-waveguide
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
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.
Same assignee
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