Varifocal occlusion in optical see-through near-eye display with single phase-only liquid crystal on silicon

We propose a novel near-eye display optics that supports three-dimensional mutual occlusion. By exploiting the polarization-control properties of the phase-only liquid crystal on silicon (LCoS), we achieve real see-through scene masking as well as virtual digital scene imaging using a single LCoS. Dynamic depth control of the real scene mask and virtual digital image is also achieved by using a focus tunable lens (FTL) pair of opposite curvatures. The proposed configuration using a single LCoS and opposite curvature FTL pair enables the self-alignment of the mask and image at arbitrary depth without distorting the see-through view of the real scene. We verified the feasibility of the proposed optics using two optical benchtop setups: one with two off-the-shelf FTLs for continuous depth control, and the other with a single Pancharatnam-Berry phase type FTL for the improved form factor.