Scholarlink

<p>We gained insights into how the geometrical parameters of core–shell SiO<sub>2</sub>@Au and SiO<sub>2</sub>@Ag nanohelix arrays influence their optical activity. The enhanced optical activity of these structures manifested as an asymmetrical optical response when they were illuminated with circularly polarized light with different handedness. The tunability and enhancement of the optical activity in the visible spectrum were realized by exploiting the chiral morphology and plasmonic properties of these nanostructures. The chirality-induced differential transmission spectra were calculated for a left-handed helix array with varying geometric parameters. The spectra initially dipped into the negative value before proceeding toward the positive value. The optical behavior was remarkably affected by an increase in the major radius and metal shell thickness of the nanohelix, as evidenced by the red and blue shifts observed in the spectral position of the negative peak, respectively. These two parameters could act as the main controls for tuning the optical response. Although the total height and core radius had a minimal effect on the optical behavior, they could offer additional degrees of freedom. The magnitude of the differential spectra showed an enhanced sensitivity to structural changes in SiO<sub>2</sub>@Ag helix arrays. The derived value of the dissymmetry factor was nearly 1.8, suggesting that the optical activity of core–shell plasmonic nanohelix arrays is improved compared with that of the chiral structures reported in literature. Such findings can lead to novel nanocomposite designs with robust optical chirality in the visible wavelength region.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Influence of Geometrical Parameters on the Optical Activity of Core–Shell SiO2@Au and SiO2@Ag Plasmonic Nanohelix Arrays

  • 期刊论文

  • 发表日期：

    2025年2月18日

查看全文
  • Bassam AL-Qadi

摘要

We gained insights into how the geometrical parameters of core–shell SiO2@Au and SiO2@Ag nanohelix arrays influence their optical activity. The enhanced optical activity of these structures manifested as an asymmetrical optical response when they were illuminated with circularly polarized light with different handedness. The tunability and enhancement of the optical activity in the visible spectrum were realized by exploiting the chiral morphology and plasmonic properties of these nanostructures. The chirality-induced differential transmission spectra were calculated for a left-handed helix array with varying geometric parameters. The spectra initially dipped into the negative value before proceeding toward the positive value. The optical behavior was remarkably affected by an increase in the major radius and metal shell thickness of the nanohelix, as evidenced by the red and blue shifts observed in the spectral position of the negative peak, respectively. These two parameters could act as the main controls for tuning the optical response. Although the total height and core radius had a minimal effect on the optical behavior, they could offer additional degrees of freedom. The magnitude of the differential spectra showed an enhanced sensitivity to structural changes in SiO2@Ag helix arrays. The derived value of the dissymmetry factor was nearly 1.8, suggesting that the optical activity of core–shell plasmonic nanohelix arrays is improved compared with that of the chiral structures reported in literature. Such findings can lead to novel nanocomposite designs with robust optical chirality in the visible wavelength region.