Broadband near-infrared fibers dispersion measurement using white-light spectral interferometry

A new technique for an experimental determination of the effective refractive index, group refractive index and dispersion of fibers in a broad near-infrared spectral range is presented. The method is based on a white-light spectral interference which utilizes an unbalanced Michelson interferometer. The effective refractive index is obtained by a direct fitting the cosine function to the spectral interference pattern recorded by a low resolution spectrometer. The method has been tested in the spectral range of 1000–1700 nm both with standard telecommunication fibers and a sample of a photonic fiber. The accuracy of dispersion measurement (0.16psnm·km) exceeds those from the previously reported near-infrared white-light spectral interference methods.