Solitons in a third-order nonlinear Schrödinger equation with the pseudo-Raman scattering and spatially decreasing second-order dispersion
N. V. Aseeva, E. M. Gromov, I. V. Onosova, V. V. Tyutin
National Research University Higher School of Economics (HSE), 603155 Nizhny Novgorod, Russia
Abstract
Evolution of solitons is addressed in the framework of a third-
order nonlinear Schrödinger equation (NLSE), including nonlinear
dispersion, third-order dispersion and a pseudo-stimulated-Raman-scattering
(pseudo-SRS) term, i.e., a spatial-domain counterpart of the SRS term which
is well known as a part of the temporal-domain NLSE in optics. In this
context, it is induced by the underlying interaction of the high-frequency
envelope wave with a damped low-frequency wave mode. Also spatial
inhomogeneity of the second-order dispersion (SOD) is assumed. As a result it
is shown that the wavenumber downshift of solitons, caused by the pseudo-SRS,
can be compensated with the upshift provided by decreasing SOD coefficients.
Analytical results and numerical results are in a good agreement.