# [TECH] Optical Fiber Communications
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**Optical Fiber Communications** transmits data as light pulses through glass fibers, providing the high-bandwidth, low-loss backbone of the internet and global telecommunications.
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## Overview
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Charles Kao (1966) showed that glass fibers could transmit light over long distances if impurities were reduced. Corning Glass (1970) produced fibers with 20 dB/km loss — the threshold for practicality. Erbium-doped fiber amplifiers (1987) eliminated the need for electronic repeaters every 100 km. Wavelength-division multiplexing (WDM) allows dozens of different wavelengths (colours) on one fiber, multiplying capacity. Transatlantic fiber cables (1988) replaced satellite links; submarine cables now carry ~99% of international internet traffic.
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## Key Actors
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- **Companies**: Corning (optical fiber, 1970), AT&T Bell Labs, Ciena (WDM, 1992), Pirelli Cables, NEC, Alcatel-Lucent
- **Inventors**: Charles Kao (1933–2018), Robert Maurer, Donald Keck, Peter Schultz (Corning trio)
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## Key Patents
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- Maurer, R., Keck, D. & Schultz, P. US Patent 3,711,262 (1973) — low-loss optical fiber
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## Economic Value
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Global fiber optics market: **$20 billion/year** (2023, Grand View Research). Optical fiber enables the internet, which contributes ~$11T/year to global GDP. Submarine cable systems alone carry $10T/day in financial transactions.
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## Notes
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Grand View Research *Optical Fiber Market* 2023. **Nobel Prize 2009** to Charles Kao. McKinsey estimate of internet GDP contribution from *The Internet Economy* report.
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# Parents
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* [TECH] Laser (Device)⏎