Spectral Modulation through the Hybridization of Mie-Scatterers and Quasi-Guided Mode Resonances: Realizing Full and Gradients of Structural Color

Jang, Jaehyuck; Badloe, Trevon; Yang, Younghwan; Lee, Taejun; Mun, Jungho; Rho, Junsuk

doi:10.1021/acsnano.0c05656

Cited by 126 publications

(115 citation statements)

References 52 publications

Supporting

Mentioning

115

Contrasting

Order By: Relevance

“…As a result, since the complex refractive index of a‐Si:H can be fine‐tuned by controlling the structural disorder of silicon‐hydrogen bonding through the deposition parameters of PECVD, in addition to the ease of fabrication and increased substrate selectivity, low‐loss a‐Si:H is a promising material to significantly improve the efficiency of silicon‐based photonic devices that could play a key role in future photonic applications. [ 51,52 ] In combination with promising design methods such as semi‐continuous metasurfaces, [ 53–55 ] deep‐learning processes, [ 56,57 ] and topological optimization, [ 58 ] low‐loss a‐Si:H is a candidate for the use in all‐dielectric metasurfaces at visible frequencies.…”

Section: Discussionmentioning

confidence: 99%

Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low‐Loss Photonic Platform at Visible Frequencies

et al. 2021

Self Cite

View full text Add to dashboard Cite

The high refractive index of hydrogenated amorphous silicon (a‐Si:H) at optical frequencies is an essential property for the efficient modulation of the phase and amplitude of light. However, substantial optical loss represented by its high extinction coefficient prevents it from being utilized widely. Here, the bonding configurations of a‐Si:H are investigated, in order to manipulate the extinction coefficient and produce a material that is competitive with conventional transparent materials, such as titanium dioxide and gallium nitride. This is achieved by controlling the hydrogenation and silicon disorder by adjusting the chemical deposition conditions. The extinction coefficient of the low‐loss a‐Si:H reaches a minimum of 0.082 at the wavelength of 450 nm, which is lower than that of crystalline silicon (0.13). Beam‐steering metasurfaces are demonstrated to validate the low‐loss optical properties, reaching measured efficiencies of 42%, 62%, and 75% at the wavelengths of 450, 532, and 635 nm, respectively. Considering its compatibility with mature complementary metal–oxide–semiconductor processes, the low‐loss a‐Si:H will provide a platform for efficient photonic operating in the full visible regime.

show abstract

Section: Discussionmentioning

confidence: 99%

Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low‐Loss Photonic Platform at Visible Frequencies

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The enhancement of scattering resonances of Si NCs via hybridization with the lattice modes has been studied in the past for periodic arrays of Si nanoparticles. [ 33,35 ] In this article, however, the close vicinity of the randomly positioned Si NCs in each region allows this process to convert such a region into a coherent unit or network. The strength of the hybridization of such units with the lattice modes depends on the detuning of the RA from the scattering resonances of individual Si NCs and optical confinement supported by the structure.…”

Section: Discussionmentioning

confidence: 99%

“…As discussed in the following, the nature of the inter‐NC coupling can be associated with the dipole resonances of the individual Si NCs. [ 35 ]…”

Section: Lattice‐induced Coherent Coupling Of Si Ncsmentioning

confidence: 99%

“…The results in Figure 3a′–c′ suggest that when the refractive index condition is satisfied, i.e.,

n_{sub} \approx n_{sup}

, and the planar diffractive coupling becomes efficient, i.e., RA condition is met, a Si NC experiences a much stronger electric field coupling with other Si NCs. This refers to the lattice‐induced inter‐NC coupling, leading to coherent coupling of Si NCs [ 35 ] and formation of field hotspots between Si NCs. [ 29 ] The in‐phase coupling of Si NCs also suggests coherent networks of Si NCs that extend along the length of each region, which is far larger than the sizes of each Si NC.…”

Section: Lattice‐induced Coherent Coupling Of Si Ncsmentioning

confidence: 99%

See 1 more Smart Citation

Coherent Networks of Si Nanocrystals: Tunable Collective Resonances with Narrow Spectral Widths

Sadeghi

Gutha

2021

Advanced Photonics Research

View full text Add to dashboard Cite

The ultralong coherent networks of Si nanocrystals (NCs) via lattice‐enhanced dipole–dipole coupling and the formation of disordered arrays of phase‐correlated field hotspots are studied. Such arrays occur in structures consisting of Si NCs randomly positioned inside long strips that are periodically repeated. The theoretical results predict the formation of all‐dielectric coherent networks of Si NCs, formed via in‐phase coupling of the resonances generated by diffraction of light. Such networks are extended along the lengths of the strips while supporting high field enhancement associated with the phase‐correlated chains of field hotspots between the nanocrystals. It is shown that these phenomena occur at the wavelengths where the Rayleigh anomaly condition is satisfied. Under this condition the electric field is squeezed between two field‐impenetrable regions, causing efficient concentration of electromagnetic energy along the disordered arrays of Si NCs in each strip. The results show that these arrays act as coherently assembled units that are efficiently coupled with the lattice modes, forming highly tunable collective resonances with spectral widths less than 5 nm. These results pave the way for all‐dielectric‐tunable optical filters with very small losses and near‐perfect reflectivity and laser systems based on Si NCs.

show abstract

“…As a validation of the completely switchable encryption, practical applications of QR code encryption, two-color image switching, and overlapped images resolving are demonstrated. Our polarization-sensitive metasurfaces could be integrated and used as high-security information encryption, security tag, multichannel imaging, and dynamic display [46][47][48].…”

Section: Discussionmentioning

confidence: 99%

Near-zero reflection of all-dielectric structural coloration enabling polarization-sensitive optical encryption with enhanced switchability

et al. 2020

Self Cite

View full text Add to dashboard Cite

Structural coloration using metasurfaces has been steadily researched to overcome the limitations of conventional color printing using pigments by improving the resolution, lowering the toxicity, and increasing the durability. Many metasurfaces have been demonstrated for dynamic structural coloration to convert images at the visible spectrum. However, the previous works cannot reach near-zero scattering when colors are turned-off, preventing it from being cryptographic applications. Herein, we propose a completely on/off switchable structural coloration with polarization-sensitive metasurfaces, enabling full-colored images to be displayed and hidden through the control of the polarization of incident light. It is confirmed that the nanostructure exhibits the polarization-dependent magnetic field distributions, and near-zero scattering is realized when the polarization of incident light is perpendicular to the long axis of the nanofins. Also, the metasurfaces are made up of triple-nanofin structures whose lengths affect locations of resonance peaks, resulting in full-color spectrum coverages. With such advantages, a QR code image, a two-color object image, and an overlapped dual-portrait image are obtained with the metasurfaces. Such demonstrations will provide potential applications in the fields of high-security information encryption, security tag, multichannel imaging, and dynamic displays.

show abstract

Spectral Modulation through the Hybridization of Mie-Scatterers and Quasi-Guided Mode Resonances: Realizing Full and Gradients of Structural Color

Cited by 126 publications

References 52 publications

Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low‐Loss Photonic Platform at Visible Frequencies

Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low‐Loss Photonic Platform at Visible Frequencies

Coherent Networks of Si Nanocrystals: Tunable Collective Resonances with Narrow Spectral Widths

Near-zero reflection of all-dielectric structural coloration enabling polarization-sensitive optical encryption with enhanced switchability

Contact Info

Product

Resources

About