Group velocity dispersion in fused-silica sample measured using white-light interferometry with the equalization wavelength determination

Group velocity dispersion (GVD) in fused-silica sample of known thickness is measured in the spectral range from 490 to 870 nm using a new technique of white-light spectral interferometry. In the experimental set-up with the compensated Michelson interferometer and fused-silica sample inserted in it, the equalization wavelength as a function of the mirror displacement in the interferometer is measured by a low-resolution miniature fibre-optic spectrometer. From the measured values either the differential group refractive index of the sample as a function of the wavelength or the difference of the mirror displacements at two different wavelengths is obtained to determine the GVD in the sample. Moreover it is confirmed that the GVD in the fused-silica sample agrees well with that resulting from the Sellmeier dispersion equation.