基于MEMS技术的超表面三维显示研究

Metasurface 3D Display Based on MEMS Technology

三维物体的空间结构复杂,光波场很难用具体的函数准确描述,三维显示非常困难。提出一种硅基微机电系统(MEMS)二维扫描平台与超表面元件集成的三维显示技术,利用视觉暂留特性,建立快速三维显示扫描片上结构,理论上实现了物像信息的三维图像的重构。利用层析法实现物体的三维显示,采用Gerchberg-Saxton(GS)算法获得单层二维图像单元相位值,建立基于几何相位原理的二维超表面结构,获得了二维全息平面像。依据空间、时间序列构建了由离散的多层超表面二维全息像形成的物体三维显示。结果表明:所获得的二维全息像峰值信噪比大于20 dB;所设计的片上二维扫描平台在0.1 s内能够完成9幅二维全息像的叠加,三维显示的帧率达11 frame/s。研究成果为快速调制的三维显示提供了微型化的系统级解决方案和理论模型。

The spatial structure of 3D objects is inherently complex,and making an accurate description of the light wave field using specific functions is challenging.Hence,achieving 3D display is very difficult.In this paper,a 3D display technology is proposed by integrating the silicon-based micro-electro-mechanical system(MEMS)2D scanning platform with the metasurface element.By leveraging the persistence of vision,an on-chip scanning structure was created to realize 3D display.As a result,the object image information was theoretically reconfigured to 3D display.Further,the chromatography method was used to construct 3D display,and the phase value of the single layer 2D image element was obtained using the Gerchberg-Saxton(GS)algorithm.Then,2D metasurface structures were established based on the geometric phase principle,and the corresponding 2D holographic plane images were achieved based on the principle of Fraunhofer diffraction.Finally,a 3D display was built through those above discrete metasurface holograms according to space and time series.The results show that the peak signal-to-noise ratio of 2D holograms is greater than 20 dB.Moreover,the proposed on-chip 2D scanning platform can assemble nine pieces of 2D holograms within O.1 s,thereby enabling a reconfigured 3D display that can achieve a frame rate of 11 frame/s.Thus,this research findings provide a miniaturized system-level settlement and theoretical model for fast-modulating 3D display.