Experimental test for violation of duality on a photon beam
  We test for evidence violating the duality invariant ratio of photon beam irradiance and wave intensity. Split beams from a 633 nm HeNe laser are intersected at a diffraction grating complementary to the resultant interference pattern. An output beam from the grating, depleted in irradiance relative to wave intensity from the perspective of local realism, is transiently intersected with a beam from an independent HeNe laser and measured irradiance is amplified by ~4% in conflict with quantum mechanics. 
Daniel Mirell, Stuart Mirell