用于彩色屏显的双层耦合光栅设计  

Design of Double-Layer Coupling Gratings for Full-Color Helmet Mounted Display

作　　者：尤勐[1,2] 黄战华[1,2] 蔡怀宇[1,2] 

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072 [2]天津大学光电信息技术教育部重点实验室,天津300072

出　　处：《光学学报》2012年第10期29-34,共6页Acta Optica Sinica

摘　　要：在彩色波导全息平视器的设计中,易出现色彩不均和结构复杂的问题。将折射率、厚度各异的膜层,分别嵌入双层波导中,对一种新型的双层耦合光栅结构进行了优化设计。基于严格耦合波理论(RCWA)的计算表明,该双层光栅可实现主视场内较均匀的彩色成像,且结构精简。相较于传统的体全息元件,该结构批量制造的可靠性更高。双层光栅的设计分别以470nm和632nm为中心波长,实现衍射能量的相互补偿。优化结构参数后,当入射角在[-11°,11°]内变化时,主视场内RGB三波长的衍射效率(DE)可大于85%,各波长间最大的效率差异可小于5%。In the design of full-color waveguide holographic head-up display, the color is always uneven or the structure is over-complex. A novel double coupling grating structure is designed and optimized with embedded layers of different refractive indexes and thicknesses. Based on rigorous coupled-wave analysis （RCWA）, the calculations show that the structure can achieve a more uniform color imaging in the primary field of view. Itrs simplified and reliable for mass production. The double-grating is designed with central wavelength of 470 nm and 632 nm, respectively, to compensate the diffraction energy. After optimization, when the incident angle changes during the range from -11°to 11°, the diffraction efficiency （DE） of the RGB wavelengths is greater than 85 % in the primary field of view and the maximum efficiency differs by less than 5 %.

关 键 词：光栅 衍射效率 严格耦合波理论 

分 类 号：O436.1[机械工程—光学工程]