M2.7: Fourier spectroscopy
In this experiment the reflectance of crystals in the infrared spectral range are studied polarization dependent. From the reflectance the frequency, strength, and the damping of lattice vibrations are obtained by fitting the data using a Drude model. The experimental technique used to measure the reflectance is Fourier spectroscopy. Here not the spectrum itself but its Fourier transform the so called interferogram is measured. The spectrum is calculated from the interferogram by a Fourier transformation. The effect of different choices of parameters applying the Fourier transformation is studied by measuring absorption lines of water vapour.