# [TECH] Laser (Device)

**The Laser** (Light Amplification by Stimulated Emission of Radiation) is a device producing coherent, monochromatic, collimated light, with applications spanning communications, manufacturing, medicine, and precision measurement.

## Overview

Theodore Maiman's first ruby laser (1960) was quickly followed by helium-neon (1960), semiconductor (1962), CO₂ (1964), and dye lasers. By the 1980s, semiconductor diode lasers enabled CD players, optical fiber communications, laser printers, and barcode scanners. High-power lasers cut and weld steel. Ultrashort pulse lasers (femtosecond) enable eye surgery (LASIK), multiphoton microscopy, and attosecond physics. Laser interferometry at LIGO detects gravitational waves.

## Key Actors

- **Companies**: Hughes Aircraft (first laser), Bell Labs, Coherent Inc. (1966), II-VI (now Coherent), IPG Photonics, JDSU, Lumentum
- **Inventors**: Theodore Maiman (1927–2007), Nick Holonyak Jr. (diode laser, 1962)

## Key Patents

- Schawlow, A. & Townes, C. US Patent 2,929,922 (1960) — laser (optical maser)
- Hall, R.N. US Patent 3,245,002 (1966) — semiconductor laser

## Economic Value

Global laser market: **USD 19 billion/year** (2023, Strategies Unlimited). Industrial laser applications (cutting, welding): USD 5B. Medical lasers: USD 3B. Laser communications (optical fiber): enables USD 30B+ infrastructure. Consumer (barcode, DVD, laser pointers): USD 3B.

## Notes

Strategies Unlimited *Annual Laser Market Review* 2023. Optical fiber communications, enabled by semiconductor lasers, supports the internet — value USD 11T+/year. Medical laser vision correction (LASIK) alone: 9M procedures/year, USD 3B market.

## What This Enables

- **[TECH] Optical Fiber Communications** — Semiconductor laser diodes operating at 1310/1550 nm are the light sources in every fiber-optic transmitter.
- **[TECH] LIGO Gravitational Wave Detector** — LIGO uses a stabilised Nd:YAG laser at 1064 nm as its reference light source for the 4 km interferometer arms.

## Discovery Character
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**Surprise level**: High — Early assessments called the laser "a solution looking for a problem." Within a decade it had found hundreds of problems: fiber optic communications, surgery, precision measurement, barcode scanning, CD players, and gravitational wave detection all depend on it. The breadth of application exceeded all forecasts.
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**Mode**: Systematic-engineering following systematic theory. Maiman's ruby laser (1960) was rapid systematic engineering: he selected ruby over more fashionable materials by correctly calculating its quantum efficiency (others had dismissed ruby as inefficient based on an error). He succeeded in weeks where better-funded groups had spent years. The lesson is that systematic engineering guided by correct physics beats Edisonian searching.
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# Parents

* [SCI] Laser Physics & Stimulated Emission
* [SCI] Laser Physics & Stimulated Emission