Abstract

Since the famous works by Hanbury Brown and Twiss, the existence of intensity correlations in thermal light is a well-known fact. A little less evident is that two independent thermal sources form a fourth-order interference pattern. This simple result is sometimes forgotten when the experiments on quantum intensity interference are discussed: there is nothing quantum in the very fact that the intensities of two independent beams interfere. The difference between quantum and classical predictions is only quantitative.¹

© 1996 Optical Society of America