Separation of measurement of the refractive index and the geometrical thickness by use of a wavelength-scanning interferometer with a confocal microscope

摘要

An improved system for the separate measurement of the refractive index and the geometrical thickness that constitutes a hybrid configuration of a confocal microscope and a wavelength-scanning heterodyne interferometer with a laser diode is presented. Thc optical path difference can be measured in less than 1 s, which is 10 times quicker than with the low-coherence interferometry previously used, and with a resolution of 10 μm with a fixed reference mirror. Separate measurement of thc refractive index and thc geometrical thickness of glass plates was demonstrated by usc of the arrangement in place of the low-coherence interferometer used previously.