Gwanho Yoon

Gwanho Yoon received his bachelor's degree at mechanical engineering department in Pohang University of Science and Technologyin 2015, and Ph.D. degree at mechanical engineering department in PohangUniversity of Science and Technology in 2020. After that, he works as apostdoctoral researcher at mechanical engineering department in Pohang University of Science and Technology. From 2021, he works as an assistant professor at department of manufacturing systems and design engineering in Seoul National University of Science and Technology.

Scalable manufacturing of dielectricmetasurfaces

GwanhoYoon¹

¹Department of Manufacturing Systems andDesign Engineering, Seoul National University of Science and Technology, Seoul01811, Republic of Korea

Metasurfaces that consist of subwavelength antenna array have demonstrated many promising applications such as achromatic lenses, high-resolution holograms and subwavelength color printing. Plasmonic metasurfaces suffer from low efficiency in the visible whereas dielectric materials such as titanium dioxidedrastically increase efficiency in the whole visible range. However, practicaluse of metasurfaces is still hindered by limitations of conventional nanofabrication.

Here, wedemonstrate a highly-productive scalable nanoprinting method to manufacture dielectric metasurfaces at low cost. A main idea is that transferred patternsof UV-curable resin from a printing mold directly work as metasurfaces withoutany secondary operations such as thin film deposition and etching, but theproblem is that the refractive index of the typical resin is not high enoughfor metasurfaces. Therefore, we develop the effective medium of nanoparticle composite (NPC) that consists of high-index dielectric nanoparticle (NP)inclusion in the matrix of UV-curable resin. This hierarchy enables to achievethe sufficiently-high refractive index for metasurfaces. The effective refractive index of the NPC is calculated using an effective medium approximation, and the theoretical prediction agrees well with experimental measurements which confirm that the effective refractive index of the NPC canbe increased and controlled by the content of NPs. Experimental demonstrationof high-efficiency dielectric metasurfaces including metaholograms and metalenses confirms the feasibility of our method that overcomes the bottlenecks in practical use of metasurfaces.