One-dimensional-diffraction-grating-based waveguide holographic periscopes with two-coordinate exit-pupil expansion

Subject of study. Waveguide holographic periscopes (WHPs) based on one-dimensional diffraction gratings (DGs) and their application to exit-pupil multiplication in augmented-reality displays are studied. Aim of study. The aim of this study is to identify new, more energy-efficient design variants of WHPs. Method. In this study, computer modeling was performed with original software. Experimental samples of WHPs were fabricated, and prototype augmented-reality display systems, based on these periscopes, were developed. Main results. The results show that, in the considered configurations, when waveguide rays reconstruct the DGs, the 2nd diffraction orders arise, whose intensity, in certain cases, can exceed that of the 1st diffraction orders. The multiplied rays at the output of the WHP remain parallel, and the system remains anaberrational in a first approximation. For WHPs based on such a one-dimensional surface-relief-phase DG, a regime of two-dimensional multiplication of the exit pupil under oblique beam incidence is revealed. Practical significance. The proposed scheme for constructing a waveguide holographic exit-pupil multiplexer provides significantly high energy efficiency (up to 8–10 times for certain field-of-view angles) while maintaining exceptional structural simplicity. The proposed solutions can be used in the development of head-up and augmented-reality display systems.