Abstract

A number of optical experiments in which quantum mechanics is tested and the laws of classical probability are violated will be described. These all make use of the phenomenon in non-linear optics known as parametric down-conversion, in which an incident pump photon effectively splits into two correlated, lower frequency signal and idler photons in an entangled quantum state. We show that two-photon coincidence measurements of signal and idler photons violate classical probability by at least 600 standard deviations. Other measurements involving two down-converters lead to the realization of a ″quantum eraser″ and suggest a reinterpretation of the usual quantum wave function.

© 1992 Optical Society of America