[17p-WL2_201-1~16] 3.11 Nanoscale optical science and near-field optics

2:45 PM - 3:00 PM JST(5:45 AM - 6:00 AM UTC)

[17p-WL2_201-6] Fabrication and Optical Characterization of Al Plasmonic Chiral Metasurfaces Exhibiting Broadband Reflective Circular Dichroism in the Visible Region

〇Kotaro Ito¹, Takeshi Kato^2,3, Kazumasa Hiramatsu¹, Atsushi Motogaito¹ (1.Mie Univ., 2.IMaSS Nagoya Univ., 3.Nagoya Univ.)

Keywords:

Chiral metasurface,Surface plasmon resonance,Reflective circular dichroism

In this study, we designed, fabricated, and characterized an aluminum (Al) plasmonic chiral metasurface exhibiting high circular dichroism over a broad visible wavelength range. A reflective metasurface composed of convex Al chiral nanostructures was designed, and numerical simulations based on rigorous coupled-wave analysis (RCWA) demonstrated a strong reflective circular dichroism (RCD) exceeding 0.4 in the wavelength range of 380–650 nm. Based on the design, samples were fabricated and their optical properties were evaluated by reflectance measurements. The fabricated metasurface exhibited a maximum RCD of 0.18 in the visible region from 400 to 500 nm. Comparison with simulations revealed that the RCD is highly sensitive to the Al film thickness, providing important design guidelines for further optimization of fabrication processes and broadband visible metasurface devices.