How can I reproduce the wavefront interference photon detector seen on Nova?

davesplays

I am looking for someone that can tell me how to reproduce this experiment sen on nova last week A rectangular black box was used with a low power ? 1mw red laser . A long box was used there were 2 vertical openings left and right of the laser path to the photon detector. There was no direct line of sight path to the photon detector. The wavefront that apparently preceded the laser's source of photons produced and third interference photon detection smear directly inline with the laser whose path was obstructed.