Integrated optical (IO) microsystems for interferometric analysis can be used in sensing applications playing quite different roles; in particular they can operate by detecting the transmission changes induced by some chemical or biological adsorbate coming in contact with the optical chip in a region close to an integrated waveguide and interacting with the evanescent field coupled to the waveguide. Alternatively, IO microsystems can act as transducers of the variations of the properties of an optical signal, namely the intensity, originated by the presence of chemical or biological compounds along the optical path between a light source and the IO microsystem. In the last case, we are dealing with IO microsystems suitable to perform Absorption or Emission Fourier Spectroscopy. In both cases, interferometry is the most convenient tool that can be used to perform high resolution …