Design of high efficiency achromatic metalens with large operation bandwidth using bilayer architecture
基于双层结构的大工作带宽高效消色差元透镜设计
二分子膜アーキテクチャを使用した広い動作帯域幅を備えた高効率アクロマティックメタレンズの設計
이중층 아키텍처를 사용하여 넓은 동작 대역폭을 갖는 고효율 무채색 금속 설계
Diseño de metalentes acromáticos de alta eficiencia con gran ancho de banda de operación utilizando arquitectura bicapa
Conception de métalènes achromatiques à haute efficacité avec une large bande passante de fonctionnement en utilisant une architecture bicouche
Разработка высокоэффективных ахроматических металин с большой полосой пропускания с использованием двухслойной архитектуры
Yilin Wang 王艺霖 ¹, Qingbin Fan 范庆斌 ¹, Ting Xu 徐挺 ¹ ²
¹ National Laboratory of Solid-State Microstructures, Key Laboratory of Intelligent Optical Sensing and Integration and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
中国 南京 南京大学 现代工程与应用科学学院 固体微结构物理国家重点实验室 智能光传感与调控技术教育部重点实验室
² Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
中国 南京 南京大学人工微结构科学与技术协同创新中心
Achromatic metalens composed of arrays of subwavelength nanostructures with spatially varying geometries is attractive for a number of optical applications. However, the limited degree of freedom in the single layer achromatic metasurface design makes it difficult to simultaneously guarantee the sufficient phase dispersion and high diffraction efficiency, which restricts the achromatic bandwidth and efficiency of metalens.
Here we propose and demonstrate a high efficiency achromatic metalens with diffraction-limited focusing capability at the wavelength ranging from 1000 nm to 1700 nm. The metalens comprises two stacked nanopillar metasurfaces, by which the required focusing phase and dispersion compensation can be controlled independently. As a result, in addition to the large achromatic bandwidth, the averaged focusing efficiency of the bilayer metalens is higher than 64% at the near-infrared region.
Our design opens up the possibility to obtain the required phase dispersion and efficiency simultaneously, which is of great significance to design broadband metasurface-based optical devices.
