A system and method for measuring interferences are disclosed. The system is based on the concept of a composite interferometer. The sample is measured while a simultaneous compensation of the phase deviation due to the relative displacement of the optical delay component between the measurements at different pixels of the sample is performed. In the application of profilometry, the information of the surface profile of a material is obtained from the phase shift of the interference signal. By using the proposed compensation mechanism, an axial resolution at nanometer scale can be achieved. For the measurement of a thin film, a polarized probe beam is oblique incident on the sample. The system can perform a simultaneous measurement of the refractive index and the thickness of the thin film. From the ratio of the intensities of the interferograms of TE and TM waves as well as the phase shifts of the interferograms, the refractive index and the thickness of the thin film can then be obtained simultaneously.