A compact in-situ ellipsometer using the liquid crystal variable retarder

Abstract

For monitoring the optical properties of material under a dynamical processing, we design a compact in-situ ellipsometry by using a liquid crystal (LC) phase retarder. Since the key issue of an accurate ellipsometer is the alignment of each optical component in the system, hence we not only proposed the alignment procedure, we also calibrated the phase retardation of LC retarder for this in-situ ellipsometry. The azimuths of polarizers and phase retarders can be aligned by the analytical solutions of the azimuthal deviations. The phase retardation can be directly determined by the intensity ratio technique.