Three new azobenzene polymers have been synthesized by polymerization of cyanazobenzene monomers with different numbers of methylene groups attached to the cyanazobenzene dye. The rearrangement of the anisotropic azobenzene moieties in them was initiated by illumination with linearly polarized light (488 nm), and the optical anisotropy due to this arrangement has been investigated. The photobirefringence can be erased by illumination with circularly polarized light and re-induced to the same value with linearly polarized light. We show that films from these polymers can be used as optically controlled reversible polarization elements.