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Updated: Aug 4, 2025
Demonstration of Equal-Intensity Beam Generation by Dielectric Metasurfaces
Published on: June 7, 2019
Sodium-Based Concave Metasurfaces for High Performing Plasmonic Optical Filters by Templated
Yuhan Yang1, Hanyu Fu1, Huanhuan Su2
1National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, P. R. China.
Abstract:
Optical filters have aroused tremendous excitement in advanced photonic instruments and modern digital displays due to their flexible capability of spectrum manipulation. Plasmonic metasurfaces of narrow bandwidth, high spectral contrast, and robust structure tolerance are highly desired for optical filtration (especially in the visible regime) but rather challenging as large spectral broadening from intrinsic ohmic loss and design/fabrication deviations. Here the high-performing sodium-based metasurfaces are demonstrated for optical filtration across 450 to 750 nm by unique structure design of spatially decoupled concave surfaces and precise fabrication through templated solidification of liquid metals. Thanks to the distinct suppression of metallic loss as well as fabrication tolerance of interfacial structures, the as-prepared concave metasurfaces enable a minimum linewidth of ≈15 nm, a maximal optical contrast of ≈93%, and a high measure-to-design spectral match ratio ≈1500. These results have for the first time pushed the operation wavelengths of sodium-based plasmonic devices from infrared to visible which in turn demonstrates the capability of filling the blank of commercial dielectric optical filters thus far.
