Opt Express. 2023 Feb 13;31(4):6601-6614. doi: 10.1364/OE.482447.
We propose a two-dimensional exit pupil expansion (2D-EPE) design of a diffractive waveguide (DW) based on polarization volume grating (PVG). The designed waveguide structure and pupil expansion principle are introduced in this paper. The light propagation behavior and available field of view (FoV) of the proposed waveguide are investigated by simulations. In addition, the waveguide sample based on the proposed design is prepared, and an imaging system based on a monochromatic MicroLED projector is built for AR imaging experiments. The experimental results show that the prepared waveguide system can achieve a clear AR display with a diagonal FoV of 30° and obtain an exit pupil magnification of nearly 20 times compared to the entrance pupil size. The optical imaging efficiency was measured to be 3.85%, and the backward light leakage rate was as low as 8.7%. This work further enhances the feasibility and practicality of the PVG-waveguide technology and provides a promising candidate for AR-DW applications.
我们提出了一种基于偏振体光栅（PVG）的衍射波导（DW）的二维出射瞳孔扩展（2D-EPE）设计。本文介绍了所设计的波导结构和瞳孔扩展原理。通过模拟研究了所提出的波导的光传播行为和可用视场（FoV）。此外，还制备了基于所提出设计的波导样品，并为 AR 成像实验构建了基于单色 MicroLED 投影仪的成像系统。实验结果表明，所制备的波导系统能够实现对角线 FoV 为 30°的清晰 AR 显示，并与入瞳尺寸相比，获得近 20 倍的出射瞳孔放大倍率。测量的光学成像效率为 3.85%，后向光泄漏率低至 8.7%。这项工作进一步增强了 PVG 波导技术的可行性和实用性，为 AR-DW 应用提供了有前途的候选方案。
