2026-06-11 筑波大学
キラル（鏡像を重ね合わせることができない構造）なπ共役高分子（炭素原子の単結合と二重結合が交互に連なった分子）が形成するマイクロ球体において、球体表面に渦状の分子配向が生じることを見いだしました。また、この球体では、レーザー発振が円環放射（土星の輪）状に起こることが分かりました。
＜関連情報＞
- https://www.tsukuba.ac.jp/journal/technology-materials/20260611140000.html
- https://pubs.acs.org/doi/10.1021/jacs.6c01819
キラルポリマー微小球からの角度選択的光共鳴と円形放射状レーザー発振 Angle-Selective Optical Resonance and Circular Radial Lasing from a Chiral Polymeric Microsphere
Osamu Oki,Wenbo Lin,Soh Kushida,Sota Nakayama,Hiroshi Yamagishi,Fumio Sasaki,Jer-Shing Huang,Satoshi Iwamoto,and Yohei Yamamoto
Journal of the American Chemical Society Published: June 8, 2026
DOI:https://doi.org/10.1021/jacs.6c01819
Abstract
Spheres are inherently isotropic in structure, while their optical isotropy can be broken when the refractive index distribution is not isotropic. For microspheres made of molecules, spheres with bipolar or twisted-bipolar molecular configuration exhibit distinctive birefringence inside the sphere. However, impacts of the molecular arrangement on the spherical surface to optical functions have not yet been elaborated. Herein, we present optical sphere resonators exhibiting angular-selective resonance and lasing derived from its topological and chiral surface. Self-assembly of chiral π-conjugated polymers forms microspheres, whose surface is featured with the swirl molecular arrangement arising from diametrical topological defects. Despite its spherical morphology, the microsphere shows angular-selective whispering gallery mode (WGM) resonance emission, which is predominantly localized along the particular circular orbits. Furthermore, upon strong photoexcitation, the microsphere exhibits WGM laser oscillation with a distinct azimuthal direction. This work demonstrates the impacts of the textured spherical surface on optical properties and provides the virtues of the chiral sphere resonators as spatio-selective light amplifiers and directional lasers without shape change.
