Determination of the chromatic dispersion in single-mode fiber waveguides by a ring interferometer method

A method was developed and apparatus was assembled for determination of the spectral dependence of the chromatic dispersion in a long ( ~ 1 km) section of a single-mode fiber waveguide with the aid of a ring interferometer in which the radiation phase was modulated. The radiation source was a halogen lamp coupled to a monochromator. The reproducibility in the determination of the delay time was δτ ~ 0.04 ns/km. The measured chromatic dispersion agreed well with that calculated using the refractive index profile of the blank from which the investigated fiber waveguide was drawn.