A novel scheme for measuring the relative phase difference between S and P polarization in optically denser medium

We demonstrate applications of a novel setup which is used for measuring relative phase difference between S and P polarization at oblique incidence point in optically denser medium by analyzing the relative frequency shift of adjacent axial modes of S and P resonances of a monolithic folded Fabry-Perot cavity (MFC). The relative frequency shift of adjacent axial modes of S and P resonances of MFC is around 1.030 GHz for the confocal MFC cavity and 0.3869 GHz for the parallel MFC cavity respectively. The relative phase difference at reflection point A in optically denser medium is inferred to be around -167.4{\deg} for confocal cavity and -201.1{\deg} for parallel cavity separately. This scheme can be used to measure the relative phase difference in optically denser mediums which is out of measuring range of Ellipsometry.