Voir sur FrenchStream. The film discusses the evolution and potential of using light waves, particularly coherent light, for communication. It highlights the development of lasers at Bell Telephone Laboratories, explaining how they produce a highly controlled and intense beam of light that could revolutionize communication. The film emphasizes the vast possibilities of lasers, including applications in telecommunications, surgery, and exploring the universe, suggesting that this technology represents a significant step in humanity's understanding and use of light.