Collaborating with Jean Brossel, he researched quantum mechanics, the interaction between light and atoms, and spectroscopy.

He won the Nobel Prize in Physics in 1966 "for the discovery and development of optical methods for studying Hertzian resonances in atoms".

He was president of the board of the Institut d'optique théorique et appliquée and served as the first chairman of the non-governmental organization (NGO) Action Against Hunger.

Over the forty years that followed, this group trained many young physicists, including Nobel laureates Claude Cohen Tannoudji and Serge Haroche, and had a significant impact on the development of atomic physics in France.

[6][7] As a result, for the first time in human history, a World Constituent Assembly convened to draft and adopt the Constitution for the Federation of Earth.