基于双重体光栅的波导显示系统视场扩展研究

Field-of-View Expansion of Waveguide Display System with Double-Layer Volume Grating

体全息波导显示系统的视场角受限于光栅衍射响应带宽,无法满足人们对大视场显示的需求。为扩展波导显示视场角,基于严格耦合波理论模型分析了波导显示视场角的影响因素,进一步提出了一种可有效扩展衍射响应带宽的双重体光栅波导结构,通过变角度分次曝光法完成光栅制备,并搭建全息波导显示系统。成像结果表明,该显示系统的水平和竖直视场角可分别扩展至33.4°和22.6°,对角线视场角为40.3°。

The fields-of-view of volume holographic waveguide display systems are often limited by the grating diffraction response bandwidth,which still cannot meet people’s needs for large field-of-view display.In order to expand the field-of-view of the waveguide display,the influencing factors of the field-of-view of the waveguide display are analyzed based on the strictly coupled wave theory model,and a double-layer volume grating waveguide structure that can effectively expand the diffraction response bandwidth is proposed.The grating is prepared by the variable-angle fractional exposure method,and the holographic waveguide display system is built.The imaging results show that the horizontal and vertical fields-of-view of the display system can be expanded to 33.4° and 22.6° respectively,and the diagonal viewing angle is 40.3°.