We investigate modulational instability in normally dispersive highly birefringent fibers. By means of a technique based on a two-frequency pump field we are able to provide evidence for strong nonlinear dependence of the modulational instability spectra. This dependence manifests itself by the appearance of a nonlinear spectral gap in which modulational instability vanishes.
© 1996 Optical Society of America
P. Tchofo Dinda, G. Millot, E. Seve, and M. Haelterman, "Demonstration of a nonlinear gap in the modulational instability spectra of wave propagation in highly birefringent fibers," Opt. Lett. 21, 1640-1642 (1996)