▎ 摘　　要

We used pump-probe spectroscopy to study the dependence of optical pump-induced change of graphene extinction coefficient on polarization. We find that the optical pump-induced change of graphene extinction coefficient is polarization-dependent for light with energy identical to that of the excitation light; this dependence decreases rapidly after optical excitation. However, the change of extinction coefficient is isotropic for light with energy much smaller than that of the excitation light. The spatial distribution of momenta of non-equilibrium carriers accounts for this polarization dependence. These results provide a potential way for manipulating graphene's transient optical response characteristics for applications in ultrafast photonics. (C) 2015 Optical Society of America