Colloidal Mie Resonators for All‐Dielectric Metaoptics

Abstract

High refractive index dielectric nanostructures exhibiting electric and magnetic Mie resonances offer a powerful platform for realizing unprecedented control of electromagnetic waves at the nanoscale and enhanced light–matter interactions. Dielectric metasurfaces with a variety of functionalities are realized due to the recent developments of nanofabrication technologies. In addition, colloidal dispersions of high refractive index dielectric nanoparticles have emerged as a special form of metamaterials that leads to a wider range of applications in photonics. This review focuses on the recent developments of colloidal Mie resonators made of moderate (2.5–3.5) to high (>3.5) refractive index dielectrics operating in the visible to near‐infrared range. Starting from the brief summary of fundamental properties of spherical dielectric nanoparticles, fabrication methods of colloidal Mie resonators composed of different materials and optical functionalities such as the enhanced light–matter interactions, the chirality, and the structural color generation are overviewed.

Structure–Property–Performance Relationships of Dielectric Cu2O Nanoparticles for Mie Resonance-Enhanced Dye Sensitization

“…The Mie resonances can occur in plasmonic materials that exhibit negative permittivity (ɛ < 0) as well as dielectric (ɛ > 0) materials with moderate (2.5-3.5) and high refractive index values (>3.5). [24][25][26][27][28][29][30][31][32] The dielectric Mie resonance-enhanced dye-sensitization proposed in Figure 1c is, therefore, most suitable for DSP systems built on metal oxide semiconductors with moderate and high refractive index values. Such metal oxide semiconductors include cerium(IV) oxide (CeO2), cuprous oxide (Cu2O), hematite iron oxide (α-Fe2O3), and titanium dioxide (TiO2).…”

Structure–Property–Performance Relationships of Cuprous Oxide Nanostructures for Dielectric Mie Resonance-Enhanced Photocatalysis

“…When Mie resonances occur in the positive permittivity region (ε > 0), the resonances are known as dielectric resonances. Specifically, dielectric resonances can occur in materials with moderate (2.5–3.5) and high refractive indices (>3.5) . Compared to plasmonic Mie resonances, which exhibit only the electric multipole resonances (e.g., electric dipole, quadrupole.…”

Template‐Assisted Self‐Assembly of Colloidal Silicon Nanoparticles for All‐Dielectric Nanoantenna

“…Furthermore, a variety of highly sophisticated metasurfaces composed of designed arrays of high-index NPs such shape uniformity of NPs. [32] Unfortunately, many of Si NP samples previously produced [33][34][35] do not satisfy these requirements, and thus the template-assisted self-assembly method has not been successfully applied for the formation of the assembly. As a result, optical studies of dielectric NP oligomers have been limited to a few kinds of very simple structures such as the dimers accidentally formed by agglomeration of NPs.…”