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 %.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2012年第10期29-34,共6页
Acta Optica Sinica
关键词
光栅
衍射效率
严格耦合波理论
grating
diffraction efficiency
rigorous coupled-wave analysis
