Chromatic dispersion measurement in graded-index multimode optical fibers

The chromatic dispersion observed in a graded-index multimode optical fiber is a function of the radial position of the launched light. When a graded-index multimode optical fiber is overfilled spatially and angularly, the chromatic dispersion observed is an average (composite) chromatic dispersion over all of the possible launches. Under certain assumptions, the relationship between the chromatic dispersion observed for the overfilled fiber and the chromatic dispersion of any restrictive launch can be determined. This relationship can be used to predict the composite graded-index multimode optical fiber chromatic dispersion from the measurement of the chromatic dispersion of a single simplified launch, such as a single-mode fiber launch. Preliminary experimental results confirm this approach.>