P HYSICAL R EVIEW LETTERS

Abstract

We observe strong violation of Bells inequality in an Einstein-Podolsky-Rosen-type experiment with independent observers. Our experiment definitely implements the ideas behind the well-known work by Aspect et al. We for the first time fully enforce the condition of locality, a central assumption in the derivation of Bells theorem. The necessary spacelike separation of the observations is achieved by sufficient physical distance between the measurement stations, by ultrafast and random setting of the analyzers, and by completely independent data registration.