講演情報
[8p-A22-2]Broadband Visible Reflective Circular Dichroism in an Aluminum Chiral Metasurface
〇Atsushi Motogaito1, Ryune Fukushi1, Yoshiki Takeshima1, Kotaro Ito1, Takeshi Kato2,3, Kazumasa Hiramatsu1 (1.Grad. Sch. Eng., Mie Univ., 2.IMaSS, Nagoya Univ., 3.Grad. Sch. Eng., Nagoya Univ.)
キーワード：
Chiral Metasurface、Circular Dichroism、Aluminum Plasmonics
Chiral metasurfaces have attracted considerable attention for polarization control and chiral sensing because they exhibit circular dichroism (CD) much stronger than that of natural materials. In this study, we investigate broadband reflective circular dichroism (RCD) in a visible-light aluminum (Al) chiral metasurface fabricated using a lift-off-free double-layer structure. Reflectance spectra under circularly polarized illumination were measured and analyzed by rigorous coupled-wave analysis (RCWA). Broadband visible RCD was experimentally observed over the wavelength range of 508–640 nm, with a maximum value of approximately 0.12 near 540 nm. Numerical analysis revealed that polarization-dependent localization of electromagnetic fields and magnetic responses plays a key role in the generation of broadband RCD. The demonstrated Al chiral metasurface provides a promising platform for visible–UV chiroptical devices, surface-enhanced circular dichroism (SECD), and chiral sensing applications.