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') show different
Brewster-like angles and Goos-H\"anchen shifts, exhibiting a close analogy with
light propagating behavior. In a strain-induced waveguide, electrons in K and
K' valleys have different group velocities, which can be used to construct a
valley filter in graphene without the need for any external fields.Comment: 5 pages, 4 figure
