Light odyssey from Syracuse siege to laser applications  Summary

Light odyssey from Syracuse siege to laser applications  Summary

By E.H. Amara, Research Director at CDTA

The light sources found in nature can be from extraterrestrial sources (Sun, moonlight, aurora borealis, stars), as also at our planet through the light from atmospheric phenomena (lightning, fires lightning), geological (volcanic eruptions, lava), or biological (fireflies, jellyfish). To be able to use light mainly to illuminate, means have been discovered or invented by man to produce it (torch, oil lamp, candle, incandescent lamp, Neon lamp, etc.). Other applications could be envisaged from the properties of light. Man has been interested in its properties since antiquity, it was the advent of optics. This branch of physics deals with light, its behavior and its properties. Our presentation will retrace through the history of optics the odyssey of light since its first military application due to Archimedes who would have destroyed the Roman fleet by the concentration by fiery mirrors of the Sun’s rays on the Roman ships. We will review the contribution of Hellenic and Muslim civilizations from antiquity until the fall of Granada (1492), then its evolution from the 17th to the 20th centuries, with the concepts of corpuscular and then wave nature of light. The works of Pérot and Fabry on resonant cavities (1898), those of Einstein on stimulated emission (1917), and those of Kastler on optical pumping (1949), made it possible to develop the first laser by Maiman in 1960. Applications of lasers quickly appeared in the 1960s, and then entered the industry from 1980.