Intermodal modulational instability in graded-index multimode optical fibers

Opt Lett. 2017 Sep 1;42(17):3419-3422. doi: 10.1364/OL.42.003419.

Abstract

We report on the experimental observation of an intermodal noise-seeded modulational instability process (MI) taking place in the normal dispersion regime of a few-mode graded-index optical fiber. Strong power dependence of the MI spectra is observed, with a peak gain modulation frequency that scales as the square root of the injected light power. These observations are in excellent agreement with the predictions of a bimodal-MI model.