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.
© 1996 Optical Society of America
Yuri S. Kivshar and Vsevolod V. Afanasjev, "Drift instability of dark solitons in saturable media," Opt. Lett. 21, 1135-1137 (1996)