[1] He was a pupil of August Kundt at the University of Strasbourg, where he received his doctorate in 1887 with a thesis on the phase change of light upon reflection, and methods to determine the thickness of thin films.

Together with Theodor des Coudres, he built an excellent physical institute there, and appointed Peter Debye and Gregor Wentzel.

Nowadays, quantum optics replaced the problem of visualizing light waves with that of simultaneously measuring their phase and amplitude.

Monochromatic light would result in a uniform wavelength, hence a regular standing waves pattern, parallel to the mirror's surface.

Wiener added benzene to the wedge after having been criticized for not considering the possibility of having photographed thin-film interference fringes rather than standing waves.

[11] With Nernst, he repeated Wiener's experiment using a fluorescent film as detector, in order to prove that the effect was due to electric fields.

A photographic experiment for validating Fresnel's theory had already been suggested by Wilhelm Zenker (1829-1899), after a call by the French Academy of Sciences in 1865.

By exposing a thicker film, to be observed by reflection rather than by transparency, Gabriel Lippmann discovered interferential color photography, which he was awarded the Nobel prize for.