Analyzing exit pupil expansion induced interference in diffractive AR waveguide combiners

Exit pupil expansion is one the main functionalities of diffractive augmented reality (AR) waveguide combiners. Generation of interference is an inherent problem in diffractive exit pupil expansion gratings. It can significantly reduce the image quality of AR waveguide displays. In this paper, we explain qualitatively how these interference effects are generated and how they appear in the output image uniformity. We also present simulation results for two solutions preserving image sharpness. The simulation results were obtained via numerical multi-variable optimization in the Dispelix Waveguide Studio.