Interferometry technique for refractive index measurements at subcentimeter wavelengths

We demonstrate the interferometry technique for the refractive index measurements at subcentimeter wavelengths. The method is based on a path length sweeping being introduced into one of the interferometer arms, while the sample is tilted out of its normal position with respect to the incident electromagnetic radiation. The determination of the refractive index is realized through the recording of the interference patterns at several tilt angles.