Investigation of Black-Gray Soliton Interaction

We demonstrate the first experimental investigation of the interaction between black and gray solitons in an optical fiber. The fiber length equals 8 soliton distances. The repulsive character of the interaction is observed during the walk-off of the gray soliton through the black one inside the finite-width background carrier pulse. Opposite cases of the gray soliton phase profile are studied, corresponding to gray pulses with a group velocity higher and smaller than that of the carrier pulse. Numerical simulations presented show good agreement with experimental data.