Refraction and dispersion measurement using dispersive Michelson interferometer

A new approach to a dispersive Michelson interferometer (DMI) is introduced. Rings of Equal Chromatic Order (RECO) are formed by a DMI illuminated by a white light source and crossed with an auxiliary dispersion spectrograph. The theoretical foundations are developed and then applied to different glass plates (BAK1, BK7, N-LAF35 and SK4) of thicknesses (12.101, 12.473, 9.930 and 6.602 mm), respectively. The sample is introduced in one of the arms of the interferometer. The refraction and dispersion of the samples are deduced from a single RECO interferogram. The refractive index and its variation are measured across the spectral range: 0.500-0.650 µm with relative errors of 10−3 and 1.6 ×10−4, respectively. A good agreement between our measurements and reference data is found.