Angle‐, Polarization‐, and Wavelength‐Resolved Light Scattering of Single Mie Resonators Using Fourier‐Plane Spectroscopy

A solution‐based bottom‐up process to produce one‐ and two‐dimensional arrays of densely packed spherical nanoparticles (NPs) of crystalline silicon (Si), having the lowest order Mie resonance in the visible range, is developed. First, an agglomeration‐free solution of Si NPs with a narrow size distribution is prepared. By using grooves fabricated on the surface of a polymer as a template, arrays of Si NPs with different shapes are formed by a template‐assisted self‐assembly method, and then they are transferred to an arbitrary substrate. To demonstrate proper formation of Si NP arrays, polarization‐resolved scattering spectra are measured for different size linear arrays, i.e., a monomer to a pentamer, of Si NPs placed on a silica substrate. The observed spectra are well‐reproduced by the numerical simulations. When the polarization direction of incident light is parallel to the array axis, the scattering spectra are strongly modified from that of a Si NP monomer due to near‐field coupling of the electric dipole (ED) modes. In a Si NP tetramer, the peak of the ED mode overlaps with that of the magnetic dipole (MD) mode and strong forward scattering is observed at the MD peak wavelength due to the Kerker effect.

show abstract

“…The polarization dependence arises from different radiation patterns between ED and MD modes. [ 47 ]…”

Section: Resultsmentioning

confidence: 99%

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

Negoro

Sugimoto

Hinamoto

et al. 2022

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…26,33 Thanks to the spherical shape and high crystallinity, the single NP scattering spectrum agrees quite well with the theory (Figure 1b). 28,34 Figure 1c shows the photographs of Si NP inks containing different average diameter Si NPs (D = 104, 126, and 164 nm) taken in the illustrated setup. The concentrations of Si NPs are <4.0 μg/ mL.…”

Section: Resultsmentioning

confidence: 99%

“…First, we study the effect of multiple scattering on the hue, saturation, and brightness of a Si NP ink. The analysis of multiple scattering is not straightforward because the radiation pattern of a Si NP is highly anisotropic 21 and depends on the wavelength, 28 which switches from the forward to backward radiation in a relatively narrow spectral range. The nonzero absorption coefficient of Si in a blue− green range makes the treatment more complicated.…”

Section: Introductionmentioning

confidence: 99%

“…The nonzero absorption coefficient of Si in a blue–green range makes the treatment more complicated. In order to quantitatively predict a reflection color of Si NP inks with different concentrations, we develop a Monte Carlo simulation approach that takes into account the wavelength and angle-dependent scattering behavior of individual Si NPs . We demonstrate experimentally and theoretically that the reflection color, especially the hue and saturation, of a Si NP ink depends strongly on the concentration mainly due to multiple scattering in a long wavelength range.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Color Toning of Mie Resonant Silicon Nanoparticle Color Inks

Okazaki

Sugimoto

Hinamoto

et al. 2021

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

An ink of silicon nanoparticles (Si NPs) having the lowest-order Mie resonance in the visible range can generate noniridescent and nonfading structural colors in a wide area through a painting process. However, the strong wavelength dependence of the radiation pattern and the extinction coefficient make the multiple reflection behavior very complicated, and thus, a reliable tool is necessary to predict the hue, saturation, and brightness of the reflection color. In this work, a Monte Carlo simulation to predict the reflection color of Si NP inks is first developed. The simulation takes into account the scattering and absorption cross-sections, a radiation pattern of an individual NP, and multiple scattering in NP dispersion. The simulation shows that the reflection color of a Si NP ink depends strongly on the concentration because of the wavelength dependence of the multiple scattering behavior. To extend the controllable range of the hue, saturation, and brightness of Si NP inks, a mixture ink with light-absorbing carbon black (CB) NPs is developed. It is experimentally demonstrated that the combination of the Kerker-type back scattering of a Si NP and a broad absorption by a CB NP allows us to control the hue, saturation, and brightness in a wide range and to realize vivid reflection colors under room light.

show abstract

“…Figure a shows a schematic of the experimental setup for single particle scattering spectroscopy under dark‐field illumination. [ 42 ] The polarization and azimuthal angle of illumination (φ) are defined by using a polarizer and a pinhole, respectively. Figure 5b shows the illumination and detection configurations at φ = 0°.…”

Section: Resultsmentioning

confidence: 99%

Silicon Nanosphere with Accessible Magnetic Hotspot

Matsumori

Sugimoto

Fujii

2022

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

High refractive index dielectric nanoparticles supporting the magnetic dipole (MD) Mie resonance are capable of inducing strongly enhanced magnetic field at an optical frequency, and have great potential for enhancing light–matter interactions such as magnetic dipole transitions of ions and molecules. However, the magnetic hotspot is usually located inside a nanoparticle and thus the development of technology to access the hotspot remains an urgent issue. Here, a silicon (Si) nanosphere having an access hole to the magnetic hotspot is proposed. Numerical simulations for a Si nanosphere with a hole of different diameters and depths are performed. Then, a solution‐based process to dig an access hole to a Si nanosphere is developed. A spectroscopic method to analyze nanohole‐induced anisotropy of a spherical nanoantenna is also developed. Finally, in combination with numerical simulations and angle‐resolved scattering measurements of a Si nanosphere with a nanohole, it is shown that the magnetic field intensity is 100‐fold enhanced at the nanohole.

show abstract

Angle‐, Polarization‐, and Wavelength‐Resolved Light Scattering of Single Mie Resonators Using Fourier‐Plane Spectroscopy

Abstract: Figure 7. a) Simulated and b) measured scattering spectra under s-and p-polarized illumination. The data are obtained from Figure 6 at θ = 90°.

Cited by 13 publications

References 55 publications

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

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

Color Toning of Mie Resonant Silicon Nanoparticle Color Inks

Silicon Nanosphere with Accessible Magnetic Hotspot

Contact Info

Product

Resources

About