Abstract
Two-color photon pairs are selected by two double apertures placed to satisfy the phase-matching conditions at a down-conversion crystal. The different wavelengths are superposed at spatially separated points on a beamsplitter and coincident two-photon detections are measured. On adjusting phase plates in the beams before the beamsplitter an apparent nonlocal fourth-order interference effect is seen which violates Bell’s inequality by several standard deviations.
- Received 26 February 1990
DOI:https://doi.org/10.1103/PhysRevLett.64.2495
©1990 American Physical Society
