基于贝里相位的光学超颖表面波前调控特性及应用

Optical metasurfaces have the advantages of ultrathin surface-confined planar structures, ultra-small pixel size, broadband dispersion-less property and point to point controllability, thus can flexibly modulate the flow of light. Metasurfaces have been one of the quickly developed cutting edge research fields with potential important applications. Based on our previous research achievements of Pancharatnam-Berry type metasurfaces, this project is aimed at the development of the innovative theoretical, functional applications, and active tunabilities of the metasurfaces. The main research tasks and key solutions are as follows: (1) Establishing and improving the three-dimensional electric/magnetic dipole radiation theoretical model to analyze the interaction of light and metasurfaces with arbitrary incident conditions, developing analytical/semi-analytical algorithm to calculate the vector wavefront distributions through metasurfaces; (2) Studying the effective methods to enhance the efficiency of transmitted metasurfaces in visible range; (3) Revealing the multiplexing mechanisms of metasurfaces devices, to extend the abilities of various wavefront controlling with large capacity and high resolution; (4) Exploring the physical mechanisms of active wavefront tunabilites based on metasurface-graphene or metasurface-phase change material composite structures under external modulation conditions. Through the systematic studies, we lay a solid foundation of a novel type of metasurface devices with high efficiency, multi-functionality and active tunability.

超颖表面以其平面超薄、超小像素、宽带无色散以及逐点调控等优势，具备灵活的波前调控能力，成为近年来快速发展的微纳光学前沿研究领域。本项目在申请人前期提出的基于贝里相位超颖表面的研究基础上，针对超颖表面的理论设计、功能应用、动态可调仍面临的若干瓶颈问题开展系统研究。建立任意入射条件下光与超颖单元相互作用的三维电/磁偶极矩理论解析模型，发展超颖表面对光场波前逐点调控的解析/半解析矢量算法；研究提高可见光波段透射型超颖表面能量利用率的有效方案；深入分析基于超颖表面的各类复用机制, 实现超大容量、高分辨率的超颖表面多功能光波前调控；探索改变外部调制参数情况下超颖表面－石墨烯或超颖表面－相变材料复合结构对光场主动调控的物理机制，为发展出一类高效率、功能化、主动调控的超颖表面器件奠定坚实基础。

本项目主要研究基于贝里相位的超颖表面对波前的近远场调控物理机制和功能应用。本项目在完成过程中，提出了一系列提高超颖表面能量利用率，扩展超颖表面信息容量的相关理论设计和算法，并进行实验验证，比较全面地完成了研究计划中的各要点。主要研究成果有：（1）利用超颖表面实现对局部辐射场的相位、振幅、偏振等进行人为调控，产生高阶矢量光束及独立可选择衍射级次激发；（2）利用超颖表面实现空间、波长、偏振特性，实现高分辨率全息混合复用，并进一步研究宽带多平面复用算法；（3）利用理论解析算法和优化算法结合，实现大容量三维涡旋阵列生成，从而实现超颖表面多功能应用拓展和信息容量提高；（4）利用超颖表面实现表面等离激元任意波形面内操纵及多端口可调定向激发；以及（5）利用超颖表面复合结构实现对光场的主动可调特性，探索曲面共形超颖表面对光场的调制特性等。这些成果为今年研制开发新型的微纳光学器件和集成提供了理论依据，具有实际指导意义。围绕如上几个方面，一批有意义的成果在国际本领域主流刊物上发表，共发表SCI论文10篇，其中大部分论文发表在影响因子大于３的高水平期刊上。本项目为发展出一类高效率、功能化、平面超薄的亚波长光电器件奠定坚实基础。