Improved technique for measuring refractive index and thickness of a transparent plate

摘要

The phase difference between s- and p-polarizations of a circularly polarized heterodyne light beam reflected from a transparent plate is measured. The measured data is substituted into the specially derived equations and the refractive index can be calculated. Next, the variations of phase difference between s- and p-polarizations due to the wavelength shift and the extraction of the plate in a modified Michelson interferometer are measured. Then, its thickness can be calculated based on the measured value of refractive index, the variations of phase difference, and the specified value of wavelength shift.