The Vicissitudes of the Concept of Photon in the Twentieth Century

By Indianara Lima Silva

Universidade Federal da Bahia and Massachusetts Institute of Technology


One of the key concepts in current physics and technology is the concept of photon. Not by chance we have journals and professional societies titled Nature Photonic and IEEE Photonic Society. Nevertheless, optics and the concept of photon have not had a soft development. Brown and Pike (1995, 1406), for instance, describing the history of optics in the 20th century, called the time from 1930 to 1960 of “the calm before another storm”. I am interested in narrating that storm. Therefore, my research project roughly covers the period between 1956 and 1986, however, I will have as background the articles published by Schrödinger and by others since 1927 challenging the need of the concept of photon introduced by Einstein in 1905. I focus on the experiment performed by Hanbury Brown and Twiss in 1956; on the theoretical treatment given by Glauber in the 1960s to the theory of the quantum coherence; on the experiments carried out in the 1970s, such as the antibunching of photons; on the experiment with single photons performed by Aspect in 1986. In this perspective, I am interested in the debates about these experimental results and theoretical breakthroughs motivated by them, on the technical improvements which allowed the improvement of the apparatus, and on the professional and cultural settings in which these physicists were immersed, with special attention to their professional and intellectual interests, and the new concept of photon that emerged with the quantum optics.