消色差超表面镜和阵列研究

Along with the development of Optics and Nanophotonics, several issues have gradually stepped to the core position that attracted attentions all around the world, in particular for the miniaturization and the control of the difference in spectral response (chromatic effect) of the optical components. The former issue focuses on the recently heated optical integration, which directly determines the practicability and scalability of optical systems, as well as the possibility of multi-functionality integration. As for the latter one, the full-color or full bandwidth devices are in great demand in our recent life. Unfortunately, the chromatic aberration stems from the intrinsic dispersion characteristics of the optical materials strongly degrades the performance of optical devices. Therefore, miniaturization of optical devices without chromatic aberration consequently become highly desirable for the future optical components that have great prospect in a variety of applications, such as multi-color imaging systems, planar optoelectronics and so on. Metasurfaces have been proposed to address this issue for their abilities in flexibly shaping the electromagnetic field by manipulating its phase, amplitude, and polarization at will within a compact and easy-of-fabrication system. Many pioneering works have realized achromatic metasurface devices with limited discrete wavelengths. However, the truly broadband achromatic metasurface devices those perfectly suppress the chromatic aberration in a continuous bandwidth is still missing. Here, we aim to design a perfect achromatic metalens in a broad wavelength band. And based on such approach, we can further do dispersion engineering, such as superchromatic. Moreover, the achromatic metalens array will also be considered in this project.

随着光学和光子学的发展，一些课题逐渐走进了人们的视野，并成为领域发展的核心问题。这些课题包括研究光学系统的最小化和光学系统对频率的不同响应。前者即现今光学和光子学领域中最受关注的光学集成化问题，它直接决定了复杂的光学体系的实用性和可扩展性。而后者则与体系的色差问题相关，它决定了体系是否可以全彩或者宽带应用的问题。然而，色差普遍存在于所有光学材料。色差的存在会严重影响和限制光学系统的功能。因此如何实现集成的消色差的光学体系，就成为我们研究的一个重要课题。超表面可以作为传统光学器件的优秀替代方案，实现超薄光学系统。通过精确调节散射场的相位，偏振和强度，可以任意操控光场的各种性质。可是现有超表面消色差方案都是针对个别频率的消色差，真正连续的宽带的消色差超表面还是空白。本项目拟研制宽带连续频段的消色差超表面器件。并利用超表面的色差调控，研制超色差器件等器件。我们还会将研究拓展到消色差超透镜阵列。

申请人创新的发展了相位拆分原理，填补了宽带连续消色差器件设计原理的空白，并首次在近红外实现了宽带连续消色差超构表面器件。基于这项研究成果和申请人在微纳光学领域的研究基础，申请人在本项目研究器件获得了多项创新性研究成果：.1. 将基础相位和色差相位区分开，理清了光学器件所产生的各种相位的不同物理意义。同时对这两种相位的独立调控，可以有效的实现完美的色差调控。申请人使用只与超构单元的几何对称性相关的几何相位（与波长无关）和与超构单元中局域电磁共振相关的共振相位（与波长相关），分别实现基础相位和色差相位，成功的给出了多种宽带色差调控器件的设计方案。.2.使用纳米柱和槽结合的单元结构，首次使用超构透镜实现可见光全彩成像和视频拍摄。使用此超构透镜组成毫米尺寸的阵列，实现了可见光频段的宽带消色差光场成像，获得了高分辨率的空间三维信息。.3.针对长波段光学材料的不足，将消色差超构透镜设计拓展到长波段，实现了中红外和太赫兹消色差超构透镜，填补了这个波段消色差透镜的空白。.4.将超构透镜阵列与非线性晶体结合，同时产生了10╳10个自发参量下转换过程，制备出了100维的高维路径纠缠光源，并实现了多光子态的产生。.申请人在项目研究期间以第一作者和通讯作者发表论文19篇，包括1篇Science，2篇Nature Nanotechnology，1篇Advanced Materials，等等。总被引次数超过2000次。