【摘要】 增强现实（AR）是一种将虚拟影像叠加到现实环境的显示设备，在军事、医疗等领域具有广阔的应用前景。为提高AR显示系统的视场角，使用亚波长光栅作为双通道光波导耦合元件，基于矢量衍射理论调制光栅±1级衍射效率，并通过严格耦合波分析法（RCWA）对光栅进行仿真分析。仿真结果显示，单通道波导结构在50°视场下衍射效率在60%以上，双通道波导结构在100°视场下平均衍射效率达到70%以上，且双通道波导在400～800 nm波段范围内最低衍射效率在60%以上，转置光栅分区反射效率分别为30%、35%、32%。结果表明，相较单通道波导，双通道波导结构可以实现更大的视场角。更多还原

【Abstract】 Augmented reality is a display device that overlays virtual images into the real environment,which has a broad application prospect in military,medical and other fields. In order to improve the field of view angle of the AR display system,the sub-wavelength grating is used as the dual-channel optical waveguide coupling element. The ±1 order diffraction efficiency of the grating is modulated based on the vector diffraction theory,and the grating is simulated and analyzed by strict coupled wave analysis(RCWA). The simulation results show that the diffraction efficiency of single-channel waveguide structure is more than 60% in 50° field of view,the average diffraction efficiency of dual-channel waveguide structure is more than 70% in 100° field of view,and the lowest diffraction efficiency of dual-channel waveguide in 400～800 nm band is more than 60%. The reflection efficiency of transposed grating is 30%,35% and 32%,respectively. The results show that the dual-channel waveguide structure can achieve a larger field of view angle than the single-channel waveguide.更多还原