We demonstrate theoretically how local strains in graphene can be tailored to generate a valley-polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys ($K$ or $K^{\prime }$) show different Brewster-like angles and Goos-Hänchen shifts, exhibiting a close analogy with light propagating behavior. In a strain-induced waveguide, electrons in $K$ and $K^{\prime }$ valleys have different group velocities, which can be used to construct a valley filter in graphene without the need for any external fields.

• Received 7 October 2010

DOI:https://doi.org/10.1103/PhysRevLett.106.176802