基于超表面微纳结构的视网膜成像显示仿真研究  

Simulation study on retinal imaging display based on meta-surface micro-nano structures

作　　者：杨兰兰[1] 覃涛 屠彦[1] 仲雪飞[1] 王莉莉[1] 张宇宁[1] 王保平[1] Yang Lanlan;Qin Tao;Tu Yan;Zhong Xuefei;Wang Lili;Zhang Yuning;Wang Baoping(School of Electronic Science and Engineering,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学电子科学与工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2024年第4期990-996,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家重点研发计划资助项目(2023YFC3603603);江苏省基础研究计划资助项目(BK20212006);江苏省重点研发计划资助项目(BE2022064-4)。

摘　　要：基于广义斯涅尔定律及几何相位超表面调控原理,利用时域有限差分法研究了超表面微纳结构的聚焦特性,设计了基于麦克斯韦观察法的视网膜投影成像系统,以高斯光源模拟细光束实现了整个系统成像的仿真.首先,基于TiO_(2)超表面单元,设计了半径4.875μm、数值孔径0.44的超透镜,光线焦点位置仿真值与设计值误差仅为0.4%.然后,研究发现相同数值孔径的超透镜具有相同的成像效果,表明可将微观层面仿真推广到大尺寸.最后,对视网膜投影成像系统进行了仿真,结果表明可实现带有图案信息的像源的成像,且不同位置成像面均可还原像源图案,证明人眼的调焦不影响虚拟图像的清晰度,可有效解决辐辏聚焦矛盾.基于超表面微纳结构的视网膜投影成像显示为超薄超轻无辐辏聚焦矛盾的近眼显示器件的发展提供了一种新的选择.Based on generalized Snell's law and geometric phase metasurface regulation principle,the focusing characteristics of metasurface micro-nano structures were investigated using the finite-difference time-domain(FDTD)method.A retinal projection imaging system based on the Maxwellian view method was designed,and the imaging simulation of the whole system was realized by simulating the thin beam with Gaussian light source.Firstly,based on the TiO_(2)nano-structure unit,the metalens with a radius of 4.875μm and a numerical aperture of 0.44 was realized.The error between the simulation value and the design value of the focus position is only 0.4%.Then,it is proved that the same numerical aperture of the metalens has the same imaging effect,and therefore the micro-level simulation can be extended to large size.Finally,the simulation of the retinal projection imaging system shows that imaging of image sources with pattern information can be achieved.In addition,the image source pattern can be restored on the different imaging surfaces.It means that the focusing of the eyes does not affect the resolution of the virtual image,and the vergence-accommodation conflict(VAC)can be effectively solved.The retinal projection imaging display based on metasurface micro-nano structure provides a new choice for the development of ultra-thin,ultra-light and non-VAC near-eye display devices.

关 键 词：超表面 时域有限差分 超透镜 视网膜投影成像显示 辐辏聚焦矛盾 

分 类 号：TN27[电子电信—物理电子学]