Experimental study of elementary inter-modal nonlinear interactions in a long few-mode fiber

We report the results of an experimental investigation of inter-modal nonlinearities in a 4.7-km few-mode fiber (FMF). Both inter-modal cross-phase modulation (IM-XPM) and inter-modal four-wave mixing (IM-FWM) have been observed between waves separated by a several Terahertz.