  It is shown theoretically and experimentally that passage of a laser beam
through particular conventional Ronchi gratings prepares the beam in an altered
state that violates quantum duality. The violation is characterized by a
readily measured net transfer of energy between the prepared beam and an
unmodified beam from a similar, independent laser. Notably, the experiment is
conducted with the beams at macroscopic power levels where measurability of the
duality-violating transfer is vastly improved over that of the discrete photon
regime. These results are consistent with other recently reported experiments
that have challenged the validity of the duality-related principle of
complementarity.
