Optically mediated spin current and Fano resonance in an Aharonov-Bohm ring with a quantum dot

► Optically controlled spin transport and Fano interference in an AB ring are studied. ► Fano resonant line shape is deformed and sensitive to the light strength. ► Direction of the spin polarization can be modulated by the irradiation and bias. ► Direct tunneling of two leads can induce a sharp sign reversal of spin polarization.