Compact Augmented Reality Combiner Using Pancharatnam-Berry Phase Lens

A compact augmented reality (AR) combiner using Pancharatnam-Berry phase (PBP) lens and holographic optical element (HOE) is proposed. PBP lens is activated as a convex lens or a concave lens according to the polarization state of the input light wave. By using this characteristic, a thin AR eyepiece with a large numerical aperture (NA) is constructed. The AR eyepiece operates as a convex lens for the input light with a right-handed circular polarization state and operates as a transparent plate for the left-handed circularly polarized light. In order to adopt this AR eyepiece to the AR combiner, a chromatic aberration should be compensated. To resolve the chromatic aberration, HOE which diffracts the light rays with different profiles according to the input wavelength is designed. By combining this HOE with the AR eyepiece and a light guide, a compact AR combiner providing a wide field of view (FOV) is designed. A prototype of the proposed AR combiner is presented along with experimental results and analysis.