Photon Correlation Measurements with Beamsplitter and Photomultipliers (Lajos Jánossy)
This chapter includes a brief biography of Lajos Jánossy (1912–1978) presented by Sándor Varró (Sect. 18.1) and his translation into English from Hungarian of Jánossy’s group paper of 1954 year “Coincidences of photons traveling in coherent beams of light” (Sect. 18.2). Starting with cosmic rays research and the study of statistics of coincidences in Geiger counters, Jánossy brought some of these techniques to investigation of photon correlations using a beamsplitter and photomultipliers. Although no correlations were observed in these experiments, Jánossy’s papers of 1954–1955 are considered as forerunners of the Hanbury Brown–Twiss type correlations with visible light.