  We introduce chiral gradient metasurfaces that allow perfect transmission of
all the incident wave into a desired direction and simultaneous perfect
rotation of the polarization of the refracted wave with respect to the incident
one. Besides using gradient polarization densities which provide bending of the
refracted wave with respect to the incident one, using metasurface inclusions
that are chiral allows the polarization of the refracted wave to be rotated. We
suggest a possible realization of the proposed device by discretizing the
required equivalent surface polarization densities realized by proper helical
inclusions at each discretization point. By only using a single optically thin
layer of chiral inclusions, we are able to unprecedentedly deflect a normal
incident plane wave to a refracted plane wave at $45^{\circ}$ with $72\%$ power
efficiency which is accompanied by a $90^{\circ}$ polarization rotation. The
proposed concepts and design method may find practical applications in
polarization rotation devices at microwaves as well as in optics, especially
when the incident power is required to be deflected.
