含多层衍射光学元件的折/衍射混合头盔目镜

 基于对多层衍射元件的衍射效率的理论分析，设计了用于头盔显示器的含有多层衍射元件的60°视场折/衍射混合目镜系统。系统在设计波段和整个视场范围内衍射效率均在90 %以上，提高了光能利用率和像面对比度。目镜的出瞳距离为22 mm，出瞳直径为8 mm。调制传递函数（MTF）在25 lp/mm时全视场均在0.38以上，满足VGA分辨率要求。目镜中畸变为4.8%，垂轴色差最大为10 μm。整个系统结构紧凑，镜头总长26.8 mm，最大直径16 mm，全系统质量仅8 g，实现了光学系统的轻小型化

Hybrid refractive/diffractive eyepiece for head-mounted display with multilayer diffractive optical element

Based on the theory analysis of diffraction efficiency of multilayer diffractive optical element (MDOE), a hybrid diffractive-refractive eyepiece for head-mounted display (HMD) with MDOE was designed. The diffraction efficiency of the system at each field of view (FOV) and in design wave band was lager than 90%, which improved the utilization rate of energy and contrast ratio of image. The exit pupil distance and diameter of 60° FOV eyepiece were 22 mm and 8 mm. The distortion was less than 4.8 % and the maximum lateral color difference was 10 μm. The modulation transfer function (MTF) value was more than 0.38 for all FOV at spatial frequency 25 lp/mm. It met the requirement of VGA resolution. The structure of the total system is compact, the length of lens is 26.8 mm, the maximum diameter is 16 mm, and the weight of the entire system is only 8 g. It realizes the miniaturization optical system.