Anti-dark solitons in a single mode fiber laser

Highlights: • Anti-dark solitons have been experimentally confirmed in fiber lasers. • The fiber laser works near the zero group velocity dispersion where 3^rd order dispersion play an important role. • The features of anti-dark solitons accord well with the predictions of NLSE. We report on the experimental observation of temporal anti-dark solitons in optical fibers. Under suitable condition the average dynamics of light propagation in a unidirectional fiber ring laser is governed by the nonlinear Schrödinger equation (NLSE). Dark solitons were found in the fiber laser in the net normal cavity dispersion region. We further show experimentally that at net normal near zero cavity dispersion, where the third-order dispersion plays a role, either the dark solitons, or anti-dark solitons, or coexistence of both types of solitons could be obtained in the same fiber laser.