Tailoring nonlinear circular dichroism in nanostructures and metasurfaces [Invited]
Year: 2026
Authors: Menshikov E., De Angelis C., Frizyuk K.
Autors Affiliation: Univ Brescia, Dept Informat Engn, via Branze 38, I-25123 Brescia, Italy; Natl Inst Opt Natl Res Council, Via Branze 45, I-25123 Brescia, Italy; Karlsruhe Inst Technol, Inst Theoret Festkoerperphys, Kaiserstr 12, D-76131 Karlsruhe, Germany.
Abstract: Nonlinear circular dichroism can emerge in achiral nanostructures made of non-centrosymmetric materials due to the symmetry interplay between the particle and the nonlinear susceptibility tensor chi (2). In this work, we numerically demonstrate controlled tuning of second-harmonic circular dichroism (SH-CD) in nanostructures and metasurfaces by engineered symmetry breaking. Two mechanisms are considered: uniaxial stretching of a cluster of nanoresonators and local refractive-index modification within a high-symmetry structure. In both cases, symmetry reduction from Cnv or Dnh to lower-symmetry configurations enables nonzero SH-CD and allows switching its sign. Contrary to naive intuition, the absence or presence of global structural chirality does not guarantee the absence or presence of nonlinear circular dichroism. We further discuss subtle aspects of these symmetry conditions, their range of applicability, and their relation to geometric-phase concepts and lattice-induced chirality.(c) 2026 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
Journal/Review: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
Volume: 43 (10) Pages from: C32 to: C40
More Information: Alexander von Humboldt Foundation; Erasmus Mundus EMIMEP (CUPD81I24000080006) ; European Union Program RESTART-SMART (CUP E63C22002040007).KeyWords: 2nd-harmonic Generation; Conservation; ChiralityDOI: 10.1364/JOSAB.599859
