Abstract

Duality is often used to highlight the difference between quantum mechanics and classical physics. It expresses the fact, that observation of interference and which-way information are mutually exclusive. It has been vividly discussed^1,2 recently, whether or not the loss of interference in an arbitrary which-way experiment can always be attributed to mechanical forces. While a lot of Gedanken experiments have been proposed, there are only a few experimental results. We now report on an experiment that addresses precisely this question.³

© 1998 Optical Society of America