How perfect a perfect absorber can be?

How perfect a perfect absorber can be?

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物質理工学院 Saulius Juodkazis特任教授の国際共著論文

“Detailed Experiment-Theory Comparison of Mid-Infrared Metasurface Perfect Absorbers”

が、Micromachines に掲載されました。(DOI: https://doi.org/10.3390/mi11040409

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<Abstract>

Realisation of a perfect absorber A=1 with transmittance and reflectance T=R=0 by a thin metasurface is one of the hot topics in recent nanophotonics prompted by energy harvesting and sensor applications ( A+R+T=1 is the energy conservation). Here we tested the optical properties of over 400 structures of metal–insulator–metal (MIM) metasurfaces for a range of variation in thickness of insulator, diameter of a disc and intra-disc distance both experimentally and numerically. Conditions of a near perfect absorption A>95% with simultaneously occurring anti-reflection property ( R<5% ) was experimentally determined. Differences between the bulk vs. nano-thin film properties at mid-IR of the used materials can be of interest for plasmonic multi-metal alloys and high entropy metals.