(a) Sketch of light helicity-dependent optical spin-transfer torque on a DW. Optically generated spin-polarized photo-electrons exert spin-transfer torque only on the rotating magnetization of the DW in the perpendicular magnetized film. Outside the DW, electron spin-polarization and magnetization are collinear. (b) Differential MOKE image of the initialized DW position where the DW is geometrically pinned at the cross entrance of a 4 μm wide Hall bar. After saturation, a reversed domain is nucleated by the Oersted field generated by the nucleation current IN. Subsequently, the single DW propagates to its initial position when applying a small magnetic field of BA∼0.2 mT. The initial straight DW position can also be detected by a AHE measurement when applying the current ID along the Hall bar. The corresponding Hall signal VH corresponds to ∼11% of the total signal on compete magnetization reversal.