  We demonstrate applications of a novel scheme which is used for measuring
refractive index and thickness of thin film by analyzing the relative phase
difference and reflected ratio at reflection point of a monolithic folded
Fabry-Perot cavity (MFC). The complex refractive index and the thickness are
calculated according to the Fresnel formula. Results show that the proposed
method has a big improvement in accuracy with simple and clear operating
process compared with the conventional Ellipsometry.
