Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

NEMS-tunable dielectric chiral metasurfaces.

ABSTRACT: Active control of strong chiroptical responses in metasurfaces can offer new opportunities for optical polarization engineering. Plasmonic active chiral metasurfaces have been investigated before, but their tunable chiroptical responses is limited due to inherent loss of plasmonic resonances, thus stimulating research in low loss active dielectric chiral metasurfaces. Among diverse tuning methods, electrically tunable dielectric chiral metasurfaces are promising thanks to their potential for on-chip integration. Here, we experimentally demonstrate nano-electromechanically tunable dielectric chiral metasurfaces with reflective circular dichroism (CD). We show a difference between absolute reflection under circulary polarized incident light with orthogonal polarization of over 0.85 in simulation and over 0.45 experimentally. The devices enable continuous control of CD by induced electrostatic forces from 0.45 to 0.01 with an electrical bias of 3V. This work highlights the potential of nano-electromechanically tunable metasurfaces for scalable optical polarization modulators.

SUBMITTER: Kwon H

PROVIDER: S-EPMC9390947 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

NEMS-tunable dielectric chiral metasurfaces.

Kwon Hyounghan H Faraon Andrei A

ACS photonics 20210908 10

Active control of strong chiroptical responses in metasurfaces can offer new opportunities for optical polarization engineering. Plasmonic active chiral metasurfaces have been investigated before, but their tunable chiroptical responses is limited due to inherent loss of plasmonic resonances, thus stimulating research in low loss active dielectric chiral metasurfaces. Among diverse tuning methods, electrically tunable dielectric chiral metasurfaces are promising thanks to their potential for on- ...[more]

PMID: 35989884

Similar Datasets

All-Dielectric Chiral Metasurfaces Based on Crossed-Bowtie Nanoantennas.

Project description:Circular dichroism spectroscopy is a technique used to discriminate molecular chirality, which is essential in fields like biology, chemistry, or pharmacology where different chiral agents often show different biological activities. Nevertheless, due to the inherently weak molecular-chiroptical activity, this technique is limited to high concentrations or large analyte volumes. Finding novel ways to enhance the circular dichroism would boost the performance of these techniques. So far, the enhancement of light-matter interaction mediated by plasmons is the most common way to develop chiral plasmonic structures with extraordinarily strong chiroptical responses. However, absorptive losses of metals at optical frequencies has hindered its practical use in many scenarios. In this work, we propose an all-dielectric low-loss chiral metasurface with unit cells built by high-refractive-index crossed-bowtie nanoantennas. These unit cells, built of silicon, strongly increase the chiroptical effect through the simultaneous interaction of their electric and magnetic modes, which in contrast to other recent proposals shows at the same time a high concentration of the electric field in its gap that leads to the presence of hotspots. The proposed structure exhibits a circular dichroism spectra up to 3-fold higher than that of previous proposals that use complex plasmonic or hybrid nanostructures, making it a clear alternative to develop low-loss metasurfaces with potential applications in chiral target sensing/biosensing. For completeness, single triangular shaped and symmetric (achiral) bowtie nanostructures were also studied as possible candidates for a detection up to the single-molecule level due the lack of a circular dichroism background of the nanostructures themselves.

| S-EPMC6921257 | biostudies-literature

Tunable Light Field Modulations with Chip- and Fiber-Compatible Monolithic Dielectric Metasurfaces.

Project description:Metasurfaces with a high engineering degree of freedom are promising building blocks for applications in metalenses, beam deflectors, metaholograms, sensing, and many others. Though the fundamental and technological challenges, proposing tunable metasurfaces is still possible. Previous efforts in this field are mainly taken on designing sophisticated structures with active materials introduced. Here, we present a generic kind of monolithic dielectric metasurfaces for tunable light field modulations. Changes in the period number and surrounding refractive index enable discrete and continuous modulations of spatial light fields, respectively. We exemplify this concept in monolithic Lithium Niobate metasurfaces for tunable metalenses and beam deflectors. The utilization of monolithic dielectric materials facilitates the ready integration of the metasurfaces with both chip and optical fiber platforms. This concept is not limited by the availability of active materials or expensive and time-consuming fabrication techniques, which can be applied to any transparent dielectric materials and various optical platforms.

| S-EPMC9823379 | biostudies-literature

Tunable Chiral Optics in All-Solid-Phase Reconfigurable Dielectric Nanostructures.

Project description:Subwavelength nanostructures with tunable compositions and geometries show favorable optical functionalities for the implementation of nanophotonic systems. Precise and versatile control of structural configurations on solid substrates is essential for their applications in on-chip devices. Here, we report all-solid-phase reconfigurable chiral nanostructures with silicon nanoparticles and nanowires as the building blocks in which the configuration and chiroptical response can be tailored on-demand by dynamic manipulation of the silicon nanoparticle. We reveal that the optical chirality originates from the handedness-dependent coupling between optical resonances of the silicon nanoparticle and the silicon nanowire via numerical simulations and coupled-mode theory analysis. Furthermore, the coexisting electric and magnetic resonances support strong enhancement of optical near-field chirality, which enables label-free enantiodiscrimination of biomolecules in single nanostructures. Our results not only provide insight into the design of functional high-index materials but also bring new strategies to develop adaptive devices for photonic and electronic applications.

| S-EPMC7855985 | biostudies-literature

Planar chiral metasurfaces with maximal and tunable chiroptical response driven by bound states in the continuum.

Project description:Optical metasurfaces with high quality factors (Q-factors) of chiral resonances can boost substantially light-matter interaction for various applications of chiral response in ultrathin, active, and nonlinear metadevices. However, current approaches lack the flexibility to enhance and tune the chirality and Q-factor simultaneously. Here, we suggest a design of chiral metasurface supporting bound state in the continuum (BIC) and demonstrate experimentally chiroptical responses with ultra-high Q-factors and near-perfect circular dichroism (CD = 0.93) at optical frequencies. We employ the symmetry-reduced meta-atoms with high birefringence supporting winding elliptical eigenstate polarizations with opposite helicity. It provides a convenient way for achieving the maximal planar chirality tuned by either breaking in-plane structure symmetry or changing illumination angle. Beyond linear CD, we also achieved strong near-field enhancement CD and near-unitary nonlinear CD in the same planar chiral metasurface design with circular eigen-polarization. Sharply resonant chirality realized in planar metasurfaces promises various practical applications including chiral lasers and chiral nonlinear filters.

| S-EPMC9287326 | biostudies-literature

<i>In situ</i> tunable circular dichroism of flexible chiral metasurfaces composed of plasmonic nanorod trimers.

Project description:The circularly polarized light source is one of the keys to chiral photonic circuits and systems. However, it is difficult to integrate conventional light-emitting devices with circular polarization converters directly into compact chip-scale photonic systems partly because of their bulky structures. In this study, in situ optical chirality tunable nanorod trimer metasurfaces consisting of two types of nanorod dimers are demonstrated and integrated with a flexible polydimethylsiloxane (PDMS) substrate. The optical chirality variations originating from the tunable asymmetricity of nanorod trimers under different stretching scenarios are evaluated. Through the processes, the gap distances between nanorods are varied, and the degree of circular polarization of the transmitted wave is controlled through the manipulation of localized surface plasmon resonance (LSPR) coupling. The results reveal the circular dichroism tunability and durability of fabricated chiral metasurfaces which can be important elements for chip-scale flexible optoelectronic integrated circuits for sensing, display and communication applications.

| S-EPMC9418018 | biostudies-literature

Efficient visible light modulation based on electrically tunable all dielectric metasurfaces embedded in thin-layer nematic liquid crystals.

Project description:All-dielectric metasurfaces have attracted attention for highly efficient visible light manipulation. So far, however, they are mostly passive devices, while those allowing dynamic control remain a challenge. A highly efficient tuning mechanism is immersing the metasurface in a birefringent liquid crystal (LC), whose refractive index can be electrically controlled. Here, an all-dielectric tunable metasurface is demonstrated based on this concept, operating at visible frequencies and based on TiO2 nanodisks embedded in a thin LC layer. Small driving voltages from 3~5 V are sufficient to tune the metasurface resonances, with an associated transmission modulation of more than 65%. The metasurface optical responses, including the observed electric and magnetic dipole resonance shifts as well as the interfacial anchoring effect of the LC induced by the presence of the nanostructures, are systematically discussed. The dynamic tuning observed in the transmission spectra can pave the way to dynamically tunable metasurface devices for efficient visible light modulation applications.

| S-EPMC6572778 | biostudies-literature

Generalized Brewster effect in dielectric metasurfaces.

Project description:Polarization is a key property defining the state of light. It was discovered by Brewster, while studying light reflected from materials at different angles. This led to the first polarizers, based on Brewster's effect. Now, one of the trends in photonics is the study of miniaturized devices exhibiting similar, or improved, functionalities compared with bulk optical elements. In this work, it is theoretically predicted that a properly designed all-dielectric metasurface exhibits a generalized Brewster's effect potentially for any angle, wavelength and polarization of choice. The effect is experimentally demonstrated for an array of silicon nanodisks at visible wavelengths. The underlying physics is related to the suppressed scattering at certain angles due to the interference between the electric and magnetic dipole resonances excited in the nanoparticles. These findings open doors for Brewster phenomenon to new applications in photonics, which are not bonded to a specific polarization or angle of incidence.

| S-EPMC4735648 | biostudies-literature

Multifunctional interleaved geometric-phase dielectric metasurfaces.

Project description:Shared-aperture technology for multifunctional planar systems, performing several simultaneous tasks, was first introduced in the field of radar antennas. In photonics, effective control of the electromagnetic response can be achieved by a geometric-phase mechanism implemented within a metasurface, enabling spin-controlled phase modulation. The synthesis of the shared-aperture and geometric-phase concepts facilitates the generation of multifunctional metasurfaces. Here shared-aperture geometric-phase metasurfaces were realized via the interleaving of sparse antenna sub-arrays, forming Si-based devices consisting of multiplexed geometric-phase profiles. We study the performance limitations of interleaved nanoantenna arrays by means of a Wigner phase-space distribution to establish the ultimate information capacity of a metasurface-based photonic system. Within these limitations, we present multifunctional spin-dependent dielectric metasurfaces, and demonstrate multiple-beam technology for optical rotation sensing. We also demonstrate the possibility of achieving complete real-time control and measurement of the fundamental, intrinsic properties of light, including frequency, polarization and orbital angular momentum.

| S-EPMC6062311 | biostudies-literature

Ultrafast optical pulse shaping using dielectric metasurfaces.

Project description:Advances in ultrafast lasers, chirped pulse amplifiers, and frequency comb technology require fundamentally new pulse-modulation strategies capable of supporting unprecedentedly large bandwidth and high peak power while maintaining high spectral resolution. We demonstrate how dielectric metasurfaces can be leveraged to shape the temporal profile of a near-infrared femtosecond pulse. Finely tailored pulse-shaping operations, including splitting, compression, chirping, and higher-order distortion, are achieved using a Fourier-transform setup embedding metasurfaces able to manipulate, simultaneously and independently, the amplitude and phase of the constituent frequency components of the pulse. Exploiting metasurfaces to manipulate the temporal characteristics of light expands their impact and opens new vistas in the field of ultrafast science and technology.

| S-EPMC6689470 | biostudies-literature

High-Index Dielectric Metasurfaces Performing Mathematical Operations.

Project description:Image processing and edge detection are at the core of several newly emerging technologies, such as augmented reality, autonomous driving, and more generally object recognition. Image processing is typically performed digitally using integrated electronic circuits and algorithms, implying fundamental size and speed limitations, as well as significant power needs. On the other hand, it can also be performed in a low-power analog fashion using Fourier optics, requiring, however, bulky optical components. Here, we introduce dielectric metasurfaces that perform optical image edge detection in the analog domain using a subwavelength geometry that can be readily integrated with detectors. The metasurface is composed of a suitably engineered array of nanobeams designed to perform either first- or second-order spatial differentiation. We experimentally demonstrate the second-derivative operation on an input image, showing the potential of all-optical edge detection using a silicon metasurface geometry working at a numerical aperture as large as 0.35.

| S-EPMC6909238 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data