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How did Augustin-Jean Fresnel’s theory of light successfully predict the Poisson bright spot?

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The Greek philosopher Plato — Realism Plato, marble portrait bust copied from an original of the 4th century bce; in the Capitoline Museums, Rome.

Augustin-Jean Fresnel’s theory of light successfully predicted the Poisson bright spot by applying the wave theory of light, specifically utilizing Christiaan Huygens’s principle that every point on a wave front acts as a secondary source of spherical wavelets.1

When Fresnel submitted his mathematical description of diffraction to the French Academy of Sciences in 1818, the judge Siméon-Denis Poisson attempted to discredit the model by highlighting a counterintuitive prediction: if a parallel beam of light encountered a small spherical obstacle, the wave model necessitated a bright spot at the exact center of the circular shadow.231

Poisson considered this result absurd, but an experiment conducted by François Arago confirmed the existence of the spot, now known as Poisson’s spot. This experimental verification vindicated Fresnel’s wave model over the prevailing corpuscular theory, providing a landmark success for the wave nature of light.231