Optical Activity: Giant Optical Activity in an All‐Dielectric Spiral Nanoflower (Small 31/2018)

In article number 1800485, Ting-Hui Xiao, Zhenzhou Cheng, and Keisuke Goda report the development of an all-dielectric spiral nanoflower that exhibits giant optical activity. The largest-to-date circular-intensity difference of ≈35% is experimentally demonstrated by optimizing a magnetic quadrupole contribution of the nanoflower to scattered light. The nanoflower overcomes bottlenecks of traditional metallic platforms and enables the development of diverse chiroptical devices and applications in stereochemistry, analytical chemistry, and spin photonics.