Abstract

It is well known that according to both classical and quantum theory interference effects can still be observed by measuring intensity correlations rather than the intensity itself even in those cases in which no conventional (firstorder) interference patterns exist. Indeed, intensity correlations between two different points in the interference field of two classical plane waves with random and uncorrelated phases have maximum relative modulation amplitude of 1/2. In contrast to this, quantum fields may interfere to generate a relative modulation amplitude of up to 1. Experiments by Mandel et al^[1] are in favour of the quantum mechanical result.

© 1992 IQEC