The invention relates to a method and to a device for determining at least one piece of polarization information on a measurement point of a target sample, the device comprising:—a light source capable of emitting a rectilinearly polarized light beam, the light beam being intended to be reflected by the measurement point—a means for computing polarization information on the measurement point using the beam reflected by the target sample—at least one waveguide for guiding the incident beam towards the target sample and the reflected beam towards the computing means and—a means for rotating the polarization, capable of rotating two orthogonal polarimetric components of the incident beam after passing through the waveguide and two orthogonal polarimetric components of the reflected beam before passing through the waveguide.
