Penta-channel waveguide-based near-eye display with two-dimensional pupil expansion

Abstract

We present a penta-channel waveguide-based near-eye display as an ultra-wide-angle architecture for the metaverse. The core concept is to divide one field of view into five by placing the couplers within the regions, where only the subsets of field of view are located. Compared to its counterparts, including the single, double, triple and quad channels, our penta-channel waveguide can push the envelope of field of view further. With the aid of k-space diagram, the upper limit of field of view is illustrated and deduced. The design rules of the waveguide, 4-level grating as the in-coupler, and two-dimensional binary grating as the out-coupler are expounded. Through the rigorous coupled-wave analysis, the efficiencies of gratings can be calculated and optimized. As an overall evaluation, its key performance indicators are summarized as follows. Field of view is 109° (diagonal), eye relief is 10 mm, exit pupil is 6.2 × 6.2 mm², and pupil uniformity is 54 %.