title: Drift instability of dark solitons in saturable media.
abstract: It is shown that dark solitons display an inherent instability for a strong saturation of the nonlinear refractive index provided that the background intensity exceeds a certain critical value. Such an instability manifests itself as a drift of a black soliton that transform into a gray soliton and radiation.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kivshar
authors.forename: V V
authors.initials: VV
authors.lastname: Afanasjev