This work presents the application of Fourier Transform Analysis to obtain interaction free spectrometric measurements by means of quantum vacuum states interference. The technique relies on the basic quantum mechanical property, stating that conjugate variables are Fourier Transform pairs. Integrated Optics is exploited to set up the experimental apparatus due to the main advantages that this approach presents from the operational point of view. In particular, a 980nm laser radiation is injected in an interferometer having a Er3+ doped crystal in one arm. The pump radiation generates conversion photons propagating in the apparatus. A wavelength band filter, (975±25) nm, is placed before the detector, thus allowing to detect only the pump photons. Generating a variable phase shift δ between the two arms and detecting the interferometer output, a series of interferograms is obtained, presenting beatings …