We study numerically the evolution of ultrashort pulses in passive uniform photonic-crystal fibers designed such that their nonlinear Kerr coefficient $\gamma$ varies considerably with wavelength. Such fibers exhibit a zero-nonlinearity wavelength in addition to the zero-dispersion wavelength. We show that soliton evolution is affected considerably by the relative locations of the zero-nonlinearity and zero-dispersion wavelengths with respect to the input wavelength. Among the features observed numerically are as follows: the enhancement or suppression of the Raman-induced redshift of fundamental solitons, amplification or suppression of a dispersive wave shed by the soliton, and the splitting of a fundamental soliton into two co-propagating solitons through a dispersive wave that forms a soliton in the normal-dispersion region because of a negative value of $\gamma$ in this region.

• Received 22 April 2018

DOI:https://doi.org/10.1103/PhysRevA.98.013830