French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light.  (Wikipedia)
Other accomplishments include explaining the polarization of light , its diffraction and numerous innovations in lens design. My candidate for Mr. Optics

While Isaac Newton's theories held sway,
Streams of particles were held as light.
Thomas Young showed they were waves, like water
but the English and French still believed Newton

"Streams of particles are light" they said
Augustin-Jean said "no, light oscillates".
The English and French didn't believe him either.
The French Academy held a competition on light.

Augustin-Jean said "but light undulates".
Ampere said enter the race, tell us why it's a wave
Fresnel entered the competition for the Grand Prix
It was Fresnel versus the French corpusculars

Simeon Poisson, a judge of the race, told the committee,
"Fresnel says waves will have a spot of light in the shadow"
The committee did the experiment-- Fresnel was right
Augustin-Jean Fresnel's spot convinced the world.

Isaac Newton's optics held sway no more,
And light was a wave for a hundred years,
until we found out it was both wave and particle,
but mostly a wave