We demonstrate experimentally the existence of cross-phase-modulation-induced modulational instability in the absence of group-velocity mismatch between the interacting nonlinear dispersive waves. The experiment is performed by means of a normally dispersive isotropic bimodal fiber. The group-velocity mismatch between the fundamental and the first-order modes that constitute the two interacting waves is controlled by wavelength tuning. A strong power dependence of the modulational instability spectra is observed near the condition of group-velocity matching.
© 1997 Optical Society of America
G. Millot, S. Pitois, P. Tchofo Dinda, and M. Haelterman, "Observation of modulational instability induced by velocity-matched cross-phase modulation in a normally dispersive bimodal fiber," Opt. Lett. 22, 1686-1688 (1997)