The first-time observation of Poisson’s (or Arago’s) spot in 1818 constituted one of the most relevant experiments in the history of optics, helping discard the (at the time) favored position of attributing a corpuscular nature to light. When Fresnel presented his theory of diffraction before the French Academy of Sciences, Poisson, a member of the committee, scoffed at the fact that Fresnel’s approach predicted a bright spot in the shadow of a circular obstacle placed in the way of a beam of light. Here, we demonstrate this effect in VirtualLab Fusion, and, with the help of programmable functions, also the diffraction effects caused by different obstacles can be studied. For the latter case, we present an example of the modeling of a double-slit via a functional embodiment.
Observation of the Poisson Spot
The vital role of diffraction in the Poisson-spot experiment provided proof of the wavelike nature of light. We perform here a simulation of this key experiment.