Afshar experiment

Shahriar Afshar's experimental work was done initially at the Institute for Radiation-Induced Mass Studies (IRIMS)[12] in Boston and later reproduced at Harvard University, while he was there as a visiting researcher.

[2] The experiment was featured as the cover story in the July 24, 2004 edition of the popular science magazine New Scientist endorsed by professor John G. Cramer of the University of Washington.

[4] A follow-up paper was published in a scientific journal Foundations of Physics in January 2007[3] and featured in New Scientist in February 2007.

In Afshar's variant, light generated by a laser passes through two closely spaced circular pinholes (not slits).

[3] When the light acts as a wave, because of quantum interference one can observe that there are regions that the photons avoid, called dark fringes.

2) so that the wires lie in the dark fringes of an interference pattern which is produced by the dual pinhole setup.

Afshar argues that this behavior contradicts the principle of complementarity to the extent that it shows both wave and particle characteristics in the same experiment for the same photons.

Fig.1 Experiment without obstructing wire grid
Fig.2 Experiment with obstructing wire grid and one pinhole covered
Fig.3 Experiment with wire grid and both pinholes open. The wires lie in the dark fringes and thus block very little light