# [TECH] Semiconductor Lasers & LEDs
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**Semiconductor Lasers** (laser diodes) and **LEDs** (light-emitting diodes) are optoelectronic devices that convert electrical current to light, enabling optical communications, displays, lighting, and optical storage.
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## Overview
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Nick Holonyak demonstrated the first visible LED (red, 1962, GE). Semiconductor laser diodes achieved room-temperature continuous-wave operation (1970, Alferov/Kroemer type double heterostructure; **Nobel 2000**). Blue LEDs (Nakamura, Akasaki, Amano, 1993–1994; **Nobel 2014**) completed the RGB triad and enabled white LED lighting. Vertical-cavity surface-emitting lasers (VCSELs) enabled optical mice and 3D sensing. Distributed feedback (DFB) lasers are the workhorses of optical fiber networks.
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## Key Actors
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- **Companies**: Nichia (Nakamura's LEDs), Osram, Cree, II-VI/Coherent, Lumentum, Sony (optical storage lasers)
- **Inventors**: Nick Holonyak Jr. (1928–2022), Shuji Nakamura (1954–, **Nobel 2014**)
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## Key Patents
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- Nakamura, S. US Patent 5,578,839 (1996) — blue InGaN LED (Nichia)
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## Economic Value
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Global LED market: **$75 billion/year** (2023, MarketsandMarkets). LED lighting alone saves ~$50B/year in electricity costs globally vs. incandescent. Semiconductor laser/optical comms: $20B/year hardware.
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## Notes
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LED lighting energy savings from IEA *Tracking Clean Energy Progress* 2023. MarketsandMarkets *LED Market* 2023.
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# Parents
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* [SCI] Semiconductor Physics⏎