全息波导耦出光栅出瞳亮度均匀性的改善

Improvement of brightness uniformity of out-coupling grating in holographic waveguide

目前在AR领域,存在着全息波导显示系统的耦出光栅出瞳亮度不均匀的问题,设计并制作了一种衍射效率渐变的全息光栅以进一步提高显示光路中耦出光栅的出瞳亮度均匀性。提出移动遮挡板方案,以实现分区域地改变全息干版的曝光时间,使得到的全息光栅的衍射效率具有渐变特性,并对实验结果进行研究和分析。结果表明,系统中耦出光栅的出瞳亮度均匀性由28.57%提高到57.14%。因此采用的全息光学元件的拍摄光路和曝光方法,可以有效改善全息波导耦出光栅出瞳亮度均匀性。

At present,there is a problem of uneven brightness of the out-coupling grating of the holographic waveguide display system in the field of AR.In this paper,a holographic grating with a diffractive efficiency gradient is designed and fabricated to further improve the brightness uniformity of out-coupling grating in the display optical path.Based on theoretical analysis and discussion,this paper proposes a scheme of moving the shutter to realize the change of the exposure time of the holographic plate by divisional region,so that the diffraction efficiency of the obtained holographic grating has a gradual characteristicThe final experimental results are studied and analyzed.The results show that the uniformity of the exit pupil brightness of the coupled grating in the system increases from 28.57%to 57.14%.Therefore,the photographic optical path and exposure method of the holographic optical element used in this paper can effectively improve the uniformity of the exit pupil brightness of the holographic waveguide coupling out grating.