  Polarization correlations of two distant observers are observed by using
coherent light fields based on Stapp's formulation of nonlocality. Using a
50/50 beam splitter transformation, a vertically polarized coherent light field
is found to be entangled with a horizontally polarized coherent noise field.
The superposed light fields at each output port of the beam splitter are sent
to two distant observers, where the fields are interfered and manipulated at
each observer by using a quarter wave plate and an analyzer. The interference
signal contains information of the projection angle of the analyzer, which is
hidden by the phase noises. The nonlocal correlations between the projection
angles of two distant observers are established by analyzing their data through
analog signal multiplication without any post-selection technique. This scheme
can be used to implement Ekert's protocol for quantum key distribution.
