Broadband high-efficiency dielectric metalenses based on quasi-continuous nanostrips
基于准连续纳米跳闸的宽带高效电介质金属系统
準連続ナノトリップに基づく広帯域高効率誘電体金属システム
준연속 나노 스위치 기반 광대역 고효율 전매체 금속 시스템
Sistema de metal dieléctrico de alta eficiencia de banda ancha basado en nanoviajes cuasicocontinuos
Système de métal diélectrique à haut rendement à large bande basé sur le déclenchement nanométrique quasi - continu
Широкополосная высокоэффективная диэлектрическая металлическая система на основе квазинепрерывных нано - выключателей
¹ Key laboratory of optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044, China
中国 重庆 重庆大学光电技术及系统教育部重点实验室
² Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems, Harbin Institute of Technology, Shenzhen 518055, China
中国 深圳 哈尔滨工业大学 广东省半导体光电材料与智能光子系统重点实验室 微纳光电信息系统理论与技术工信部重点实验室
³ Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
中国 长沙 湖南大学物理与微电子科学学院 低维结构物理与器件湖南省重点实验室 微纳光电器件及应用教育部重点实验室
Benefiting from the abrupt phase changes within subwavelength thicknesses, metasurfaces have been widely applied for lightweight and compact optical systems. Simultaneous broadband and high-efficiency characteristics are highly attractive for the practical implementation of metasurfaces. However, current metasurface devices mostly adopt discrete micro/nano structures, which rarely realize both merits simultaneously.
In this paper, dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this limitation. Via quasi-continuous nanostrips metasurface, a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally demonstrated. The quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000 nm and keep a high power efficiency.
The average efficiency of the fabricated metalens reaches 54.24%, showing a significant improvement compared to the previously reported metalenses with the same thickness. The proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.
