一种单色全息平板波导显示系统的研究

Study on monochromatic holographic planar waveguide display system

设计了一种由耦出线性全息光栅和耦入体全息光栅组成的单色全息平板波导显示系统。该系统的工作原理是微型显示器发出的单色图像光波信息经过准直透镜后,通过耦入体全息光栅和耦出线性光栅把图像光波信息从平板玻璃的一端耦入,另外一端耦出,最终在出瞳位置进入人眼。介绍了全息光栅的特点,利用耦合波理论与K矢量闭合法理论推导全息光栅的视场角,同时介绍了全息光栅的设计方法,该方法是通过分束镜将激光分为物光波和参考光波,且按照一定的入射角度在全息干板上发生干涉来实现。模拟仿真结果表明:该系统显示视场角为18°×14°,出瞳距离为30mm,传递函数MTF在30lp/mm时均在0.3以上,满足目视系统的使用要求,可以应用于新一代头盔显示系统中。

A monochromatic holographic planar waveguide display system consisting of an outcoupled linear holographic grating and an in-coupled volume holographic grating was designed.The working principle of the system is that,first the monochromatic image light wave information emitted by the micro-display passes through the collimating lens,then the image light wave information is coupled from one end of the planar glass and coupled to the other end by incoupled volume holographic grating and out-coupled linear grating,and finally enters the human eye at the exit pupil position.Its characteristics of the holographic grating were introduced.The angle of view of the holographic grating was deduced theoretically using the coupled wave theory and the K-vector closed legitimate,and the design method of the holographic grating was introduced at the same time.The method divides the laser into object light wave and reference light wave by beam splitter,and realizes interference on the holographic plate according to a certain angle of incidence.The final simulation results show that the system displays a field of view angle of 18°×14°,an exit pupil distance of 30 mm,and the modulation transfer functions(MTFs)are all above 0.3 at 30 lp/mm,which satisfies the requirements of the visual system and can be applied to a new generation of helmet display systems.