Concept of a liquid-crystal polarization beamsplitter based on binary phase gratings

We propose a concept of fabricating a liquid-crystal (LC) polarization beamsplitter based on binary phase gratings. The binary grating phenomenon in the LC layer physically originates from two different interfacial interactions at periodically alternating domain boundaries. The periodic LC domains are produced by employing a single-step photoalignment technique which precisely controls the surface orientation of the LC molecules in an alternating homeotropic and hybrid aligned geometry. In this binary configuration, the polarization-separating phase modulation of an input beam is achieved in a wide range of the wavelengths under an applied voltage. The experimental data are consistent with our linearly graded binary model.