  We study on rational solutions on nonzero background of coupled Sasa-Satsuma
equations through Darboux transformation method, which take into account third
order dispersion, the term with self-frequency shift, and the term describing
self-steepening corrections to the cubic nonlinearity. We find there are some
new types of localized waves in the coupled system, such as dark-antidark
soliton pair, W-shaped soliton, dark W-shaped soliton, and the combined
localized waves of them. The results indicate that there are abundant novel
localized waves in the two-mode fiber with these high-order effects, which
would inspire experimental realization in the related physical systems.
