Design and Fabrication of Two-dimensional Holographic Grating Waveguide

Augmented reality (AR) is a technology that integrates virtual images with the real world. As the computational power of mobile electronic devices continues to advance, AR-capable mobile devices are emerging as the next-generation computing platform. To expand the exit pupil diameter and field of view of volumetric holographic grating waveguides, a novel design method for a dual-volume holographic grating waveguide with two-dimensional pupil and field of view expansion has been developed. Leveraging the multiplexing characteristics of photopolymers, we superimposed two incoherent one-dimensional gratings on a holographic material layer, achieving dual-channel propagation of the field of view, with each channel occupying half of the total field of view. These channels are then concatenated to form a complete field of view. This approach not only enlarges the eyebox but also enhances the field of view angle of the system. A performance analysis of the fabricated holographic waveguide confirms the feasibility and correctness of the proposed two-dimensional holographic waveguide in expanding both the two-dimensional eye box and the field of view. Through eye box expansion, the eye box reached 13 mm × 16 mm, the diagonal field of view reached 55°.