Book

The Laser: Light Amplification by Stimulated Emission of Radiation (original paper, 1958)

by Charles Hard Townes

Summary

This paper's central argument is that light amplification by stimulated emission of radiation, termed "laser," can be achieved by an assembly of components producing spatially and temporally coherent light. This process offers a specific means of amplifying light beyond spontaneous emission.

The paper focuses on the technical definition of a laser, differentiating it from other technologies. It establishes that a laser is characterized by its ability to produce coherent light through stimulated emission. Readers learn the precise terminology and conceptual components that define this technology.

Key concepts

  • LaserAn assembly of components which produce both spatially and temporally coherent light which is amplified by stimulated emission of radiation.
  • Stimulated emission of radiationThe physical process by which a laser amplifies light.
  • Spatially coherent lightLight waves that maintain a constant phase relationship over a spatial extent.
  • Temporally coherent lightLight waves that maintain a constant phase relationship over time.

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