Diagnosis of modal and chromatic dispersions for the LP and LP modes through temporal decomposition by means of Fourier transform.

We provide a novel approach for estimating the modal and chromatic dispersions of the and modes traversing a two-mode fiber (TMF). A modal interferometer is used to measure the differential group delay (DGD) and chromatic dispersion for the two modes in the 1260-1360 nm telecommunication band. The measurement principle is based on an investigation of a transmitted spectrum through temporal decomposition by means of a Fourier transform. The diagnosis of the DGD and chromatic dispersion for the two modes is discussed theoretically and experimentally. The experimental results obtained here exactly match those obtained previously. The salient feature of the present method is that the modal interferometer configuration makes it possible to measure both the DGD and chromatic dispersion and also estimate the shape of optical pulses traversing a TMF.