Invention of the Free Electron Laser

The 150 years since Maxwell's formulation of the field equations, Lorentz's formulation of his force law, and Einstein's formulation of special relativity have seen electrodynamics emerge as one of the most fundamental elements of scientific and technical progress in the 20th and 21st centuries. Beginning with the analysis and demonstration of Hertzian waves, these fundamental contributions have launched a series of recurring cycles of discovery and application, in which each new discovery has been exploited to support new applications, which in turn have facilitated additional new discoveries and so on, revolutionizing in the process major elements of our economy with yet more to come through the research now in progress. It is the purpose of this article to relate my recollections of the invention and development of the free electron laser (FEL) within the context of the pervasive influence of the science and technology of electrodynamics in the 20th century.