We measure fourth-order interference occurring when energy-entangled photon pairs are launched into opposite ports of a single-mode-fibre interferometer. The resulting 90% coincidence fringe visibility is limited only by dispersion and polarisation alignment. The experiment could be extended to one consisting of two identical well-separated interferometers to demonstrate violations of local realism at kilometer separations.
|Number of pages||6|
|Publication status||Published - 10 Apr 1993|