The conoscopic micro-profilometer system realized at INOA is composed of a commercial Conoprobe mounted on two motorized high-precision linear stages.

The probe (Conoprobe 1000 by Optimet) working principle is as follows:

a light beam projected by a diode laser on the sample is both reflected and back scattered, and it impinges on a uniaxial birefrangent crystal placed between two circular polarizers.

The ordinary and the extraordinary beams are then generated inside the crystal and produce an interference pattern on a photosensitive pixel array;

the measurement of the interference fringes allows to calculate the distance between the probe and the sample (quota).