Coherence and Statistical Properties of a Two-Mode Laser Beam

The first- and second-order correlation functions for the field obtained by the superposition of two laser modes through a Young's experiment are discussed both experimentally and theoretically. An electronic method we have developed for measuring certain values of the second-order correlation is contrasted with the method based on photon counting. It is shown that, in some cases, interference experiments may have advantages over the photocounting technique.