基于消色差超构光栅的AR显示光波导

Augmented Reality Display Optical Waveguide Based on Achromatic Metagrating

增强现实(AR)技术将计算机生成的虚拟信息融入现实世界,可为使用者提供沉浸式的体验,被认为是下一代显示技术,但依旧存在一些问题。针对AR显示系统中色差、色彩均匀性、光场均匀性等问题,设计一种基于消色差超构光栅的光波导解决方案。仿真超构光栅的耦出响应,在单层超构光栅的情况下,实现了三种波长光(473,532,620 nm)相同角度入射和相同角度出射,消除了色差。采用双层超构光栅,在实现消色差的基础上,进一步实现了对不同波长光的强度比例可调和耦出效率可调,改善了色彩均匀度,有望用于扩瞳。所提基于消色差超构光栅的AR显示光波导设计有望为头戴式AR显示设备提供全新设计思路。

Augmented reality(AR)technology integrates computer-generated virtual information into the real world,providing users with an immersive experience.AR technology is considered next-generation display technology;however,there are issues.In this paper,an optical waveguide design based on achromatic metagratings is proposed to solve the problems of chromatic aberration,color uniformity,and light field uniformity in the AR display system.The coupling response of metagratings is simulated.In the case of a single-layer metagrating,the light with three wavelengths(473,532,and 620 nm)is incident and emitted at the same angle,eliminating chromatic aberration.Based on this,we designed a double-layer metagrating.With the double-layer metagrating,the intensity ratio and coupling efficiency of light with different wavelengths can be adjusted,and color uniformity can be improved,which is expected to be used for pupil expansion.The proposed AR display optical waveguide design based on achromatic metagratings will offer a new design idea for AR head-mounted displays.