Anti-dark solitons in a single mode fiber laser

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.