Wu Yuanjun, Pan Chang, Lu Changtai, Zhang Yinxin, Zhang Lin, Huang Zhanhua
Opt Express. 2023 Sep 25;31(20):32799-32812. doi: 10.1364/OE.499177.
For a waveguide display device, the field of view (FOV) is a key parameter for evaluating its optical performance. To address this issue, we propose a hybrid waveguide system, which is composed of two projectors, two in-couplers, two half-mirror arrays and an out-coupler. We use two projectors to generate the left and right parts of the output image separately, which can increase the upper limit of the FOV significantly. Unlike conventional waveguide-based system, we use half-mirror arrays instead of folding gratings to realize 2D exit pupil expansion. By doing so, the total internal reflection condition can always be met during the pupil expansion process. To solve the difficulty in designing collimating optical system with large FOV, we propose a method of tilting the projection system. The hybrid waveguide system can realize a FOV of 88°(H) × 53°(V).
对于波导显示设备而言，视场（FOV）是评估其光学性能的关键参数。为解决这一问题，我们提出了一种混合波导系统，该系统由两台投影仪、两个输入耦合器、两个半反射镜阵列和一个输出耦合器组成。我们使用两台投影仪分别生成输出图像的左右部分，这可以显著提高视场的上限。与传统的基于波导的系统不同，我们使用半反射镜阵列而非折叠光栅来实现二维出射光瞳扩展。通过这样做，在光瞳扩展过程中总能满足全内反射条件。为解决设计大视场准直光学系统的困难，我们提出了一种倾斜投影系统的方法。该混合波导系统可实现88°（水平）×53°（垂直）的视场。
