Single- and double-hump femtosecond vector solitons in the coupled Sasa-Satsuma system

We construct the Darboux transformation of the coupled Sasa-Satsuma system and represent the N-soliton solutions in terms of the five-component Wronskian. We give the parametric criterion for the appearance of single- and double-hump soliton profiles, and analyze the structure and stability of double-hump solitons. We also reveal the polarization-changing collisions occurring in the femtosecond vector solitons with the third-order dispersion, self-steepening, and stimulated Raman scattering effects. Such nontrivial collisions may have applications in the ultrafast all-optical switching, computation, and signal control.