  We study Klein tunneling in polariton graphene. We show that the photonic
spin-orbit coupling associated with the energy splitting between TE and TM
photonic modes can be described as an emergent gauge field. It suppresses the
Klein tunnelling in small energy range close to the Dirac points. Thanks to
polariton spin-anisotropic interactions, polarized optical pumping allows to
create potential barriers acting on a single polariton spin. We show that the
resulting spin-dependent Klein tunneling can be used to create a perfectly
transmitting polarization rotator operating at microscopic scale.
