The Impulse Response of an Optical Fiber With Parabolic Index Profile

To the paraxial approximation there is no difference in the group delay of the modes of a parabolic index fiber. However, the wave optics treatment of the infinitely extended parabolic index medium predicts a slight difference in the group delay of the various modes. This result is used in this paper to predict the shape and width of the impulse response function of a parabolic index fiber with finite radius.