Second Harmonic Generation Optical Rotation Solely Attributable to Chirality in Plasmonic Metasurfaces

Joel T. Collins, David C. Hooper, Andrew G. Mark, Christian Kuppe, Ventsislav K. Valev

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Chiral plasmonic nanostructures, those lacking mirror symmetry, can be designed to manipulate the polarization of incident light resulting in chiroptical (chiral optical) effects such as circular dichroism (CD) and optical rotation (OR). Due to high symmetry sensitivity, corresponding effects in second-harmonic generation (SHG-CD and SHG-OR) are typically much stronger in comparison. These nonlinear effects have long been used for chiral molecular analysis and characterization; however both linear and nonlinear optical rotation can occur even in achiral structures, if the structure is birefringent due to anisotropy. Crucially, chiroptical effects resulting from anisotropy typically exhibit a strong dependence on structural orientation. Here we report a large second-harmonic generation optical rotation of ±45°, due to intrinsic chirality in a highly anisotropic helical metamaterial. The SHG intensity is found to strongly relate to the structural anisotropy; however, the angle of SHG-OR is invariant under sample rotation. We show that by tuning the geometry of anisotropic nanostructures, the interaction between anisotropy, chirality, and experimental geometry can allow even greater control over the chiroptical properties of plasmonic metamaterials.

Original languageEnglish
Pages (from-to)5445–5451
Number of pages7
JournalACS Nano
Volume12
Issue number6
Early online date31 May 2018
DOIs
Publication statusPublished - 26 Jun 2018

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Keywords

  • chirality
  • optical rotation
  • second-harmonic generation

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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