Fig. 1
(a) Schematic representation of the Freedman-Clauser (FC) experiment. Polarization correlated photons are emitted from source S, pass through rotated polarizing filters FA and FB, and are detected by quantum-sensitive photomultiplier tubes A and B. (b) The "Malus" modification of FC experiment in which the photon in arm A passes through no filters while the photon in arm B passes through two filters. (c) The "Furry" modification of FC experiment in which both photons are placed in a definite but random polarization state on leaving the source S through the use of auxiliary filters rotated through random angle (phi). (d) Coincidence rate angular dependence R(
rel) in the above three experiments, with "Malus" corresponding to (a) and (b) and "Furry" corresponding to (c).