Zhu Xiaolong, Engelberg Jacob, Remennik Sergei, Zhou Binbin, Pedersen Jonas Nyvold, Uhd Jepsen Peter, Levy Uriel, Kristensen Anders
State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
Department of Health Technology, Technical University of Denmark, Kongens Lyngby 2800, Denmark.
Nano Lett. 2022 Apr 13;22(7):2786-2792. doi: 10.1021/acs.nanolett.1c04874. Epub 2022 Mar 21.
One of the challenges for metasurface research is upscaling. The conventional methods for fabrication of metasurfaces, such as electron-beam or focused ion beam lithography, are not scalable. The use of ultraviolet steppers or nanoimprinting still requires large-size masks or stamps, which are costly and challenging in further handling. This work demonstrates a cost-effective and lithography-free method for printing optical metasurfaces. It is based on resonant absorption of laser light in an optical cavity formed by a multilayer structure of ultrathin metal and dielectric coatings. A nearly perfect light absorption is obtained via interferometric control of absorption and operating around a critical coupling condition. Controlled by the laser power, the surface undergoes a structural transition from random, semiperiodic, and periodic to amorphous patterns with nanoscale precision. The reliability, upscaling, and subwavelength resolution of this approach are demonstrated by realizing metasurfaces for structural colors, optical holograms, and diffractive optical elements.
超表面研究面临的挑战之一是扩大规模。制造超表面的传统方法，如电子束光刻或聚焦离子束光刻，无法扩大规模。使用紫外步进光刻机或纳米压印仍然需要大尺寸的掩模或印章，这成本高昂且在后续处理中具有挑战性。这项工作展示了一种用于打印光学超表面的经济高效且无需光刻的方法。它基于由超薄金属和介电涂层的多层结构形成的光学腔中激光的共振吸收。通过吸收的干涉控制并在临界耦合条件附近操作，可获得近乎完美的光吸收。受激光功率控制，表面以纳米级精度经历从随机、半周期和周期到非晶图案的结构转变。通过实现用于结构色、光学全息图和衍射光学元件的超表面，证明了该方法的可靠性、可扩展性和亚波长分辨率。
