衍射光学元件具有独特的负色散性质和以其任意的相位分布实现对光波面的任意相位调制的特点,用在光学系统中可大大简化系统结构,而光学塑料在进一步减轻系统重量方面有优势。设计了应用于头盔显示器的折／衍混合全塑料目镜,其有效焦距为30 mm,视场角为40°,出瞳距离为20 mm,出瞳直径为8 mm,由三个折射透镜和一个衍射面组成。该目镜的最大镜头直径为26 mm,总重量为7 g。对于目镜中需要重点校正的像散和垂轴色差的最大值分别为0.58 mm和18 μm,而最大畸变也仅为3.3％;角分辨率为0.44 mrad,小于人眼的最小角分辨率。

The diffractive optical element, with the negative dispersive characteristic and the random phase distributing to realize random phase modulation for wave-front, is helpful to simplify the optical system, and the optical plastic elements further reduce the weight of the system. A plastic hybrid diffractive-refractive eyepiece for head-mounted display is designed, the features of the eyepiece are 30 mm effective focal length, 40° field-of-view (FOV), 20 mm exit pupil and 8 mm exit pupil size, and which consists of three lens and one diffractive element. The maximal diameter of lens and the overall weight of this eyepiece are 26 mm and 7 g, respectively. For the image quality, the astigmatic and lateral color of the key aberrations of eyepiece are 0.58 mm and 18 μm, and the distortion is only 3.3%. The angular resolution of this eyepiece is 0.44 mrad and less than that of human eyes.