Georges Bruhat's half-shadow elliptical analyzer (1930)

Jobin Yvon designed an instrument that analyzed elliptically polarized light using the method described by Georges Bruhat. Featuring a half-wavelength half-blade followed by a linear polarizer, it allows the axes of an elliptical polarization to be isolated with great precision. The zero contrast between the two hemispheres corresponds to one of the axes of the incident polarization.