We report a two-photon interference experiment that realizes a postselection-free test of Bell's inequality based on energy-time entanglement. In contrast with all previous experiments of this type, the employed entangled states are obtained without the use of a beam splitter or a short coincidence window to "throw away" unwanted amplitudes. A (95.0±1.4)% interference fringe visibility is observed, implying a strong violation of the Bell inequality. The scheme is very compact and has demonstrated excellent stability, suggesting that it may be useful, for example, in practical quantum cryptography.
|Original language||English (US)|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|State||Published - Jan 1 1996|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics