André Maréchal

Robert Gaston André Maréchal (10 December 1916 – 14 October 2007) was a French researcher and administrator in optics.

André Maréchal was former[clarify] director general of the French Institut d'Optique.

For his thesis research, he investigated the combined effects of diffraction and aberrations and derived what is now known as the Maréchal criterion.

Formally, that a wavefront can be regarded as diffraction-limited if its RMS phase error is 14 times less than its wavelength.

Maréchal served as president of the International Commission for Optics (1962–1966), honorary vice president of the Comité français de physique, and was a founding member of the Franco-Finnish Association for Scientific and Technical Research.