ORCID Profile
0000-0001-9268-4793
Current Organisations
Nottingham Trent University
,
National University of Singapore
,
National Technical University of Ukraine Kiev Polytechnic Institute
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Nanotechnology | Nanophotonics | Photonics and Electro-Optical Engineering (excl. Communications) | Optical Technology | Photonics, Optoelectronics and Optical Communications | Nonlinear Optics and Spectroscopy | Nanofabrication, Growth and Self Assembly | Nanomaterials | Optometry and Ophthalmology | Optical Physics | Optical Properties of Materials |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Technology | Energy Conservation and Efficiency not elsewhere classified | Technological and Organisational Innovation | Automotive Equipment | Expanding Knowledge in Engineering
Related Links
Publications
Smart wearable triboelectric nanogenerator for self-powered bioelectronics and therapeutics
Publisher: Elsevier BV
Date: 04-2023
High-Efficiency Visible Light Manipulation Using Dielectric Metasurfaces
Publisher: Springer Science and Business Media LLC
Date: 24-04-2019
DOI: 10.1038/S41598-019-42444-Y
Abstract: The development of a miniaturised device that provides efficient beam manipulation with high transmittance is extremely desirable for the broad range of applications including holography, metalens, and imaging. Recently, the potential of dielectric metasurfaces has been unleashed to efficiently manipulate the beam with full 2π-phase control by overlapping the electric and magnetic dipole resonances. However, in the visible range for available materials, it comes with the price of higher absorption that reduces efficiency. Here, we have considered dielectric amorphous silicon (a-Si) nanodisk and engineered them in such a way which provides minimal absorption loss in the visible range. We have experimentally demonstrated meta-deflector with high transmittance which operates in the visible wavelengths. The supercell of proposed meta-deflector consists of 15 amorphous silicon nanodisks numerically shows the transmission efficiency of 95% and deflection efficiency of 95% at operating wavelength of 715 nm. However, experimentally measured transmission and deflection efficiencies are 83% and 71%, respectively, having the experimental deflection angle of 8.40°. Nevertheless, by reducing the supercell length, the deflection angle can be controlled, and the value 15.50° was experimentally achieved using eight disks supercell. Our results suggest a new way to realise the highly transmittance metadevice with full 2π-phase control operating with the visible light which could be applicable in the imaging, metalens, holography, and display applications.
Multipolar analysis of second-harmonic generation in (111) Gallium Arsenide nanoparticles
Publisher: IOP Publishing
Date: 03-2020
DOI: 10.1088/1742-6596/1461/1/012185
Abstract: We perform multipolar analysis of second-harmonic generation (SHG) from (111)-grown gallium arsenide (GaAs) nanoantennas and discuss its specifics. It was experimentally demonstrated that the conversion efficiency in axially-symmetric (111) GaAs nanoparticles remains constant under the polarization rotation of normally incident radiation in a wide range of particle sizes, while the SHG radiation pattern changes. We apply the analytical method based on the Lorentz lemma to explain this behaviour. The induced nonlinear current is decomposed into two rotating contributions, which are shown to generate multipoles of different parities. Thus, the total SHG intensity in the far-field is proved to be independent of the in-plane rotation of the pump polarization. Nevertheless, due to the threefold symmetry of the crystal with regard to the (111) direction, the SHG radiation pattern rotates around the polar axis repeating its shape every 60°.
Nonlinear Generation of Vector Beams From AlGaAs Nanoantennas
Publisher: American Chemical Society (ACS)
Date: 31-10-2016
DOI: 10.1021/ACS.NANOLETT.6B03525
Abstract: The quest for nanoscale light sources with designer radiation patterns and polarization has motivated the development of nanoantennas that interact strongly with the incoming light and are able to transform its frequency, radiation, and polarization patterns. Here, we demonstrate dielectric AlGaAs nanoantennas for efficient second harmonic generation, enabling the control of both directionality and polarization of nonlinear emission. This is enabled by specialized III-V semiconductor nanofabrication of high-quality AlGaAs nanostructures embedded in optically transparent low-index material, thus allowing for simultaneous forward and backward nonlinear emission. We show that the nanodisk AlGaAs antennas can emit second harmonic in preferential direction with a backward-to-forward ratio of up to five and can also generate complex vector polarization beams, including beams with radial polarization.
Magnetic-electric interference in metal-dielectric-metal oligomers: generation of magneto-electric Fano resonance
Publisher: The Optical Society
Date: 20-09-2012
DOI: 10.1364/OME.2.001407
Sum-Frequency Generation in High-Q GaP Metasurfaces Driven by Leaky-Wave Guided Modes
Publisher: American Chemical Society (ACS)
Date: 22-07-2022
DOI: 10.1021/ACS.NANOLETT.2C01349
Abstract: Resonant metasurfaces provide a unique platform for enhancing multiwave nonlinear interactions. However, the difficulties over mode matching and material transparency place significant challenges in the enhancement of these multiwave processes. Here we demonstrate efficient nonlinear sum-frequency generation (SFG) in multiresonant GaP metasurfaces based on guided-wave bound-state in the continuum resonances. The excitation of the metasurface by two near-infrared input beams generates strong SFG in the visible spectrum with a conversion efficiency of 2.5 × 10
Low-loss volume modes in a lamellar hyperbolic metamaterial slab
Publisher: Optica Publishing Group
Date: 12-03-2020
DOI: 10.1364/JOSAB.376752
Abstract: We have studied, both theoretically and experimentally, the excitation of volume modes in a lamellar metal/dielectric metamaterial with hyperbolic dispersion. The highly efficient light penetration through tens of metamaterial layers is consistent with a relatively low propagation loss. The volume modes were found to be highly sensitive to the surface roughness of the layers, which can be a detrimental factor in device applications.
Temporal broadening of attosecond photoelectron wavepackets from solid surfaces
Publisher: The Optical Society
Date: 16-04-2015
Resonant Dielectric Metagratings for Response Intensified Optical Sensing
Publisher: Wiley
Date: 04-08-2022
Abstract: The development of nanoscale optical sensors is desirable for a broad range of applications, including wearable medical‐diagnostics, biochemical detection, and environmental monitoring. Optical detection platforms based on resonant nanostructures are the golden standard for miniaturized footprint and high optical sensitivity. These sensors function by measuring a shift in resonance wavelength upon binding of analytes to their surface. However, such measurements are sensitive to intensity fluctuations of the illuminating source and its wavelength calibration, which limits their applicability. Here, a novel optical sensing concept based on diffraction measurements from resonant dielectric metagratings is proposed and experimentally demonstrated. It is shown that this approach enables the direct measurement of unknown analytes with enhanced sensitivity and without the need for intensity calibrations. The intensified sensitivity of this metagrating‐sensor is derived from combining the resonant phenomena of the nanostructures with the tailored diffraction from the metagrating, thereby providing the highest sensitivity demonstrated to date amongst grating‐based sensors. As a proof of concept, the metagrating‐sensor was validated using an antibody binding assay, achieving a femtomolar‐level limit of detection. Due to their high sensitivity and robust performance, the proposed metagrating sensors pave the way for novel miniaturized medical diagnostics and biosensing applications.
Nanoceramics: Synthesis, Characterization, and Applications
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/528348
Light–Matter interactions on the nanoscale
Publisher: Beilstein Institut
Date: 10-08-2018
DOI: 10.3762/BJNANO.9.201
Flatband mode in photonic moiré superlattice for boosting second-harmonic generation with monolayer van der Waals crystals
Publisher: Optica Publishing Group
Date: 26-04-2022
DOI: 10.1364/OL.453625
Abstract: We theoretically investigate boosting second-harmonic generation (SHG) of monolayer van der Waals crystals by employing flatband modes hosted by photonic moiré superlattices. Such a system with high quality factor and a monolayer crystal accommodated on the top of it, provides a unique opportunity to enhance and manipulate SHG emission. We show that employing a doubly resonant diagram on such a moiré superlattice system not only boosts the SHG, but also tunes the directional emission of the second-harmonic wave. Moreover, we demonstrate that a structured beam illumination could further boost SHG, with the phase structure retrieved through a two-beam second-harmonic interference configuration. These results suggest the flatband modes in moiré superlattice as a promising platform for boosting SHG with monolayer van der Waals crystals, offering new possibilities for developing compact nonlinear photonic devices.
Unveiling the Origin of Third Harmonic Generation in Hybrid ITO-Plasmonic Crystals
Publisher: Wiley
Date: 30-03-2015
Influence of symmetry breaking in pentamers on Fano resonance and near-field energy localization
Publisher: The Optical Society
Date: 02-11-2011
DOI: 10.1364/OME.1.001409
Boosting second-harmonic generation in the
LiNbO 3
Publisher: American Physical Society (APS)
Date: 12-09-2022
Electrically programmable solid-state metasurfaces via flash localised heating
Publisher: Springer Science and Business Media LLC
Date: 22-02-2023
DOI: 10.1038/S41377-023-01078-6
Abstract: In the last decades, metasurfaces have attracted much attention because of their extraordinary light-scattering properties. However, their inherently static geometry is an obstacle to many applications where dynamic tunability in their optical behaviour is required. Currently, there is a quest to enable dynamic tuning of metasurface properties, particularly with fast tuning rate, large modulation by small electrical signals, solid state and programmable across multiple pixels. Here, we demonstrate electrically tunable metasurfaces driven by thermo-optic effect and flash-heating in silicon. We show a 9-fold change in transmission by V biasing voltage and the modulation rise-time of µs. Our device consists of a silicon hole array metasurface encapsulated by transparent conducting oxide as a localised heater. It allows for video frame rate optical switching over multiple pixels that can be electrically programmed. Some of the advantages of the proposed tuning method compared with other methods are the possibility to apply it for modulation in the visible and near-infrared region, large modulation depth, working at transmission regime, exhibiting low optical loss, low input voltage requirement, and operating with higher than video-rate switching speed. The device is furthermore compatible with modern electronic display technologies and could be ideal for personal electronic devices such as flat displays, virtual reality holography and light detection and ranging, where fast, solid-state and transparent optical switches are required.
Far‐Field Polarization Engineering from Nonlinear Nanoresonators
Publisher: Wiley
Date: 10-10-2022
Abstract: Nanoresonators fabricated from low‐loss dielectrics with second‐order nonlinearity have emerged as a widespread platform for nonlinear frequency conversion at the nanoscale. However, a persisting challenge in this research is the generated complex far‐field polarization state of the upconverted light, which is a limiting factor in many applications. It will be highly desirable to generate uniform far‐field polarization states across all propagation directions, to control the polarization truly along the optical axis and to simultaneously be able to tune the polarization along the entire circumference of the Poincaré sphere by solely modifying the excitation polarization. Here, a nonlinear nanoresonator combining all these properties is theoretically proposed and experimentally demonstrated. At first, an analytical model connecting the induced multipolar content of a nanoresonator with a desired far‐field polarization is derived. Based on this, a nonlinear dielectric nanoresonator is designed to enable sum‐frequency generation (SFG) with highly pure and tuneable far‐field polarization states. In the experiment, the nanoresonators fabricated from the III‐V semiconductor gallium arsenide in (110)‐orientation are excited in an SFG scheme with in idually controllable excitation beams. The generation of highly uniform and tuneable far‐field polarization states is demonstrated by combining back‐focal plane measurements with Stokes polarimetry.
Plasmonic Nanoantennas for Multispectral Surface-Enhanced Spectroscopies
Publisher: American Chemical Society (ACS)
Date: 29-08-2013
DOI: 10.1021/JP404535X
Shaping the third-harmonic radiation from silicon nanodimers
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6NR09702B
Abstract: Recent progress in the study of resonant light confinement in high-index dielectric nanostructures suggests a new route for achieving efficient control of both electric and magnetic components of light. It also leads to the enhancement of nonlinear effects near electric and magnetic Mie resonances with an engineered radiation directionality. Here we study the third-harmonic generation from dimers composed of pairs of two identical silicon nanoparticles and demonstrate, both numerically and experimentally, that the multipolar harmonic modes generated by the dimers near the Mie resonances allow the shaping of the directionality of nonlinear radiation.
Forward and Backward Switching of Nonlinear Unidirectional Emission from GaAs Nanoantennas.
Publisher: American Chemical Society (ACS)
Date: 26-12-2020
Abstract: High-index III-V semiconductor nanoantennas have gained great attention for enhanced nonlinear light-matter interactions, in the past few years. However, the complexity of nonlinear emission profiles imposes severe constraints on practical applications, such as in optical communications and integrated optoelectronic devices. These complexities include the lack of unidirectional nonlinear emission and the severe challenges in switching between forward and backward emissions, due to the structure of the susceptibility tensor of the III-V nanoantennas. Here, we propose a solution to both issues via engineering the nonlinear tensor of the nanoantennas. The special nonlinear tensorial properties of zinc-blende material can be used to engineer the nonlinear characteristics via growing the nanoantennas along different crystalline orientations. Based on the nonlinear multipolar effect, we have designed and fabricated (110)-grown GaAs nanoantennas, with engineered tensorial properties, embedded in a transparent low-index material. Our technique provides an approach not only for unidirectional second-harmonic generation (SHG) forward or backward emission but also for switching from one to another. Importantly, switching the SHG emission directionality is obtained only by rotating the polarization of the incident light, without the need for physical variation of the antennas or the environment. This characteristic is an advantage, as compared to other nonlinear nanoantennas, including (100)- and (111)-grown III-V counterparts or silicon and germanium nanoantennas. Indeed, (110)-GaAs nanoantennas allow for engineering the nonlinear nanophotonic systems including nonlinear "Huygens metasurfaces" and offer exciting opportunities for various nonlinear nanophotonics technologies, such as nanoscale light routing and light sources, as well as multifunctional flat optical elements.
Reversible Image Contrast Manipulation with Thermally Tunable Dielectric Metasurfaces.
Publisher: Wiley
Date: 05-03-2019
Abstract: Increasing demand for higher resolution of miniaturized displays requires techniques achieving high contrast tunability of the images. Employing metasurfaces for image contrast manipulation is a new and rapidly growing field of research aiming to address this need. Here, a new technique to achieve image tuning in a reversible fashion is demonstrated by dielectric metasurfaces composed of subwavelength resonators. It is demonstrated that by controlling the temperature of a metasurface the encoded transmission pattern can be tuned. To this end, two sets of nanoresonators composed of nonconcentric silicon disks with a hole that exhibit spectrally sharp Fano resonances and forming a Yin-Yang pattern are designed and fabricated. Through exploitation of the thermo-optical properties of silicon, full control of the contrast of the Yin-Yang image is demonstrated by altering the metasurface temperature by ΔT ≈ 100 °C. This is the first demonstrated technique to control an image contrast by temperature. Importantly, the turning technique does not require manipulating the external stimulus, such as polarization or angle of the illumination and/or the refractive index of this environment. These results open many opportunities for transparent displays, optical switches, and tunable illumination systems.
Ultrasensitive Broadband Probing of Molecular Vibrational Modes with Multifrequency Optical Antennas
Publisher: American Chemical Society (ACS)
Date: 07-12-2012
DOI: 10.1021/NN304860T
Abstract: Optical antennas represent an enabling technology for enhancing the detection of molecular vibrational signatures at low concentrations and probing the chemical composition of a s le in order to identify target molecules. However, efficiently detecting different vibrational modes to determine the presence (or the absence) of a molecular species requires a multispectral interrogation in a window of several micrometers, as many molecules present informative fingerprint spectra in the mid-infrared between 2.5 and 10 μm. As most nanoantennas exhibit a narrow-band response because of their dipolar nature, they are not suitable for such applications. Here, we propose the use of multifrequency optical antennas designed for operating with a bandwidth of several octaves. We demonstrate that surface-enhanced infrared absorption gains in the order of 10(5) can be easily obtained in a spectral window of 3 μm with attomolar concentrations of molecules, providing new opportunities for ultrasensitive broadband detection of molecular species via vibrational spectroscopy techniques.
Adiabatic Nanofocusing in Hybrid Gap Plasmon Waveguides on the Silicon-on-Insulator Platform
Publisher: American Chemical Society (ACS)
Date: 20-01-2016
DOI: 10.1021/ACS.NANOLETT.5B04931
Abstract: We present an experimental demonstration of a new class of hybrid gap plasmon waveguides on the silicon-on-insulator (SOI) platform. Created by the hybridization of the plasmonic mode of a gap in a thin metal sheet and the transverse-electric (TE) photonic mode of an SOI slab, this waveguide is designed for efficient adiabatic nanofocusing simply by varying the gap width. For gap widths greater than 100 nm, the mode is primarily photonic in character and propagation lengths can be many tens of micrometers. For gap widths below 100 nm, the mode becomes plasmonic in character with field confinement predominantly within the gap region and with propagation lengths of a few microns. We estimate the electric field intensity enhancement in hybrid gap plasmon waveguide tapers at 1550 nm by three-photon absorption of selectively deposited CdSe/ZnS quantum dots within the gap. Here, we show electric field intensity enhancements of up to 167 ± 26 for a 24 nm gap, proving the viability of low loss adiabatic nanofocusing on a commercially relevant photonics platform.
Tuning Interior Nanogaps of Double-shelled Au/Ag Nanoboxes for Surface-Enhanced Raman Scattering
Publisher: Springer Science and Business Media LLC
Date: 11-02-2015
DOI: 10.1038/SREP08382
Abstract: Double-shelled Au/Ag hollow nanoboxes with precisely controlled interior nanogaps (1 to 16 nm) were synthesized for gap-tunable surface-enhanced Raman scattering (SERS). The double-shelled nanoboxes were prepared via a two-step galvanic replacement reaction approach using Ag nanocubes as the templates, while 4-aminothiolphenol (4-ATP) as SERS probe molecules were loaded between the two shells. More than 10-fold enhancement of SERS is observed from the double-shelled nanoboxes than Ag nanocubes. In addition, the SERS of the double-shelled nanoboxes increase significantly with the decrease of gap size, consistent with the theoretical prediction that smaller gap size induces larger localized electromagnetic enhancement.
Third-harmonic-upconversion enhancement from a single semiconductor nanoparticle coupled to a plasmonic antenna
Publisher: Springer Science and Business Media LLC
Date: 09-03-2014
Abstract: The ability to convert low-energy quanta into a quantum of higher energy is of great interest for a variety of applications, including bioimaging, drug delivery and photovoltaics. Although high conversion efficiencies can be achieved using macroscopic nonlinear crystals, upconverting light at the nanometre scale remains challenging because the subwavelength scale of materials prevents the exploitation of phase-matching processes. Light-plasmon interactions that occur in nanostructured noble metals have offered alternative opportunities for nonlinear upconversion of infrared light, but conversion efficiency rates remain extremely low due to the weak penetration of the exciting fields into the metal. Here, we show that third-harmonic generation from an in idual semiconductor indium tin oxide nanoparticle is significantly enhanced when coupled within a plasmonic gold dimer. The plasmonic dimer acts as a receiving optical antenna, confining the incident far-field radiation into a near field localized at its gap the indium tin oxide nanoparticle located at the plasmonic dimer gap acts as a localized nonlinear transmitter upconverting three incident photons at frequency ω into a photon at frequency 3ω. This hybrid nanodevice provides third-harmonic-generation enhancements of up to 10(6)-fold compared with an isolated indium tin oxide nanoparticle, with an effective third-order susceptibility up to 3.5 × 10(3) nm V(-2) and conversion efficiency of 0.0007%. We also show that the upconverted third-harmonic emission can be exploited to probe the near-field intensity at the plasmonic dimer gap.
Nonlinear Optical Magnetism Revealed by Second-Harmonic Generation in Nanoantennas
Publisher: American Chemical Society (ACS)
Date: 22-05-2017
DOI: 10.1021/ACS.NANOLETT.7B01488
Abstract: Nonlinear effects at the nanoscale are usually associated with the enhancement of electric fields in plasmonic structures. Recently emerged new platform for nanophotonics based on high-index dielectric nanoparticles utilizes optically induced magnetic response via multipolar Mie resonances and provides novel opportunities for nanoscale nonlinear optics. Here, we observe strong second-harmonic generation from AlGaAs nanoantennas driven by both electric and magnetic resonances. We distinguish experimentally the contribution of electric and magnetic nonlinear response by analyzing the structure of polarization states of vector beams in the second-harmonic radiation. We control continuously the transition between electric and magnetic nonlinearities by tuning polarization of the optical pump. Our results provide a direct observation of nonlinear optical magnetism through selective excitation of multipolar nonlinear modes in nanoantennas.
Unveiling the Origin of Third Harmonic Generation in Hybrid ITO-Plasmonic Crystals
Publisher: Wiley
Date: 06-2015
Enhanced light–matter interactions in dielectric nanostructures via machine-learning approach
Publisher: SPIE-Intl Soc Optical Eng
Date: 29-04-2020
Unveiling the Correlation between Nanometer-Thick Molecular Monolayer Sensitivity and Near-Field Enhancement and Localization in Coupled Plasmonic Oligomers
Publisher: American Chemical Society (ACS)
Date: 22-08-2014
DOI: 10.1021/NN5028714
Abstract: Metal nanoclusters, sometimes called metamolecules or plasmonic oligomers, exhibit interesting optical properties such as Fano resonances and optical chirality. These properties promise a variety of practical applications, particularly in ultrasensitive biochemical sensing. Here we investigate experimentally the sensitivities of plasmonic pentamers and quadrumers to the adsorption of self-assembled nanometer-thick alkanethiol monolayers. The monolayer sensitivity of such oligomers is found to be significantly higher than that of single plasmonic nanoparticles and depends on the nanocluster arrangement, constituent nanoparticle shape, and the plasmon resonance wavelength. Together with full-wave numerical simulation results and the electromagnetic perturbation theory, we unveil a direct correlation between the sensitivity and the near-field intensity enhancement and spatial localization in the plasmonic "hot" spots generated in each nanocluster. Our observation is beyond conventional considerations (such as optimizing nanoparticle geometry or narrowing resonance line width) for improving the sensing performance of metal nanoclusters-based biosensors and opens the possibilities of using plasmonic nanoclusters for single-molecule detection and identification.
Enhanced four-wave mixing from multi-resonant silicon dimer-hole membrane metasurfaces
Publisher: IOP Publishing
Date: 03-2022
Abstract: Tailoring optically resonant features in dielectric metasurfaces unveils a robust scheme to control electromagnetic near fields of light and thus to boost the nanoscale nonlinear light–matter interactions. Membrane metasurfaces offer unique possibilities for supporting multipolar resonances and meanwhile maintaining high mode volume for enhancing nonlinear frequency conversion. Here we design a silicon membrane metasurface consisting of dimer airy holes, as a versatile platform for generating four-wave mixing (FWM). We show that such a metasurface exhibits a multi-resonant feature, including a quasi bound state in the continuum (BIC) generated by the collective toroidal dipole mode excited in the designed subdiffractive periodic system. We show that via employing the BIC mode in the short-wave infrared (SWIR), together with other resonant enhanced electric near fields in the near-infrared (NIR) region, simultaneously, one can convert invisible SWIR light to visible light radiation with high efficiency, via FWM. We experimentally demonstrated a significant FWM emission enhancement from our metasurface, which leads to a conversion efficiency of 0.76 × 10 −6 using pump and signal beam peak intensities as low as 0.33 GW cm −2 and 0.17 GW cm −2 , respectively. Our results open new routes for enhancing nonlinear efficiencies for up-conversion processes.
Structural Flexibility and Disassembly Kinetics of Single Ferritins using Optical Nanotweezers
Publisher: Cold Spring Harbor Laboratory
Date: 23-09-2023
Reversible Thermal Tuning of All‐Dielectric Metasurfaces
Publisher: Wiley
Date: 03-07-2017
Spontaneous photon-pair generation from a dielectric nanoantenna
Publisher: The Optical Society
Date: 04-11-2019
Surface that perceives depth: 3D imaging with metasurfaces
Publisher: SPIE-Intl Soc Optical Eng
Date: 21-06-2019
High Fluence Chromium and Tungsten Bowtie Nano-antennas
Publisher: Springer Science and Business Media LLC
Date: 10-09-2019
DOI: 10.1038/S41598-019-49517-Y
Abstract: Nano-antennas are replicas of antennas that operate at radio-frequencies, but with considerably smaller dimensions when compared with their radio frequency counterparts. Noble metals based nano-antennas have the ability to enhance photoinduced phenomena such as localized electric fields, therefore-they have been used in various applications ranging from optical sensing and imaging to performance improvement of solar cells. However, such nano-structures can be damaged in high power applications such as heat resisted magnetic recording, solar thermo-photovoltaics and nano-scale heat transfer systems. Having a small footprint, nano-antennas cannot handle high fluences (energy density per unit area) and are subject to being damaged at adequately high power (some antennas can handle just a few milliwatts). In addition, given that nano-antennas are passive devices driven by external light sources, the potential damage of the antennas limits their use with high power lasers: this liability can be overcome by employing materials with high melting points such as chromium (Cr) and tungsten (W). In this article, we fabricate chromium and tungsten nano-antennas and demonstrate that they can handle 110 and 300 times higher fluence than that of gold (Au) counterpart, while the electric field enhancement is not significantly reduced.
Dual bound states in the continuum enhanced second harmonic generation with transition metal dichalcogenides monolayer
Publisher: Opto-Electronic Advances
Date: 2022
Complex-Birefringent Dielectric Metasurfaces for Arbitrary Polarization-Pair Transformations
Publisher: American Chemical Society (ACS)
Date: 16-10-2020
Dual‐Region Resonant Meander Metamaterial
Publisher: Wiley
Date: 19-02-2020
Boosting third-harmonic generation by a mirror-enhanced anapole resonator
Publisher: Springer Science and Business Media LLC
Date: 25-07-2018
DOI: 10.1038/S41377-018-0051-8
Abstract: We demonstrate that a dielectric anapole resonator on a metallic mirror can enhance the third harmonic emission by two orders of magnitude compared to a typical anapole resonator on an insulator substrate. By employing a gold mirror under a silicon nanodisk, we introduce a novel characteristic of the anapole mode through the spatial overlap of resonantly excited Cartesian electric and toroidal dipole modes. This is a remarkable improvement on the early demonstrations of the anapole mode in which the electric and toroidal modes interfere off-resonantly. Therefore, our system produces a significant near-field enhancement, facilitating the nonlinear process. Moreover, the mirror surface boosts the nonlinear emission via the free-charge oscillations within the interface, equivalent to producing a mirror image of the nonlinear source and the pump beneath the interface. We found that these improvements result in an extremely high experimentally obtained efficiency of 0.01%.
High-Efficiency Second Harmonic Generation from a Single Hybrid ZnO Nanowire/Au Plasmonic Nano-Oligomer
Publisher: American Chemical Society (ACS)
Date: 30-10-2014
DOI: 10.1021/NL503332F
Abstract: We introduce a plasmonic-semiconductor hybrid nanosystem, consisting of a ZnO nanowire coupled to a gold pentamer oligomer by crossing the hot-spot. It is demonstrated that the hybrid system exhibits a second harmonic (SH) conversion efficiency of ∼3 × 10(-5)%, which is among the highest values for a nanoscale object at optical frequencies reported so far. The SH intensity was found to be ∼1700 times larger than that from the same nanowire excited outside the hot-spot. Placing high nonlinear susceptibility materials precisely in plasmonic confined-field regions to enhance SH generation opens new perspectives for highly efficient light frequency up-conversion on the nanoscale.
Visible-Band Chiroptical Meta-devices with Phase-Change Adjusted Optical Chirality
Publisher: American Chemical Society (ACS)
Date: 16-09-2022
DOI: 10.1021/ACS.NANOLETT.2C02739
Abstract: Low-cost large-area chirality meta-devices (CMDs) with adjustable optical chirality are of great interest for polarization-sensitive imaging, stereoscopic display, enantioselectivity analysis, and catalysis. Currently, CMDs with adjusted chiroptical responses in the mid-infrared to terahertz band have been demonstrated by exploiting photocarriers of silicon, pressure, and phase-change of GSTs but are still absent in the visible band, which in turn limits the development of chiral nanophotonic devices. Herein, by employing a phase-change material (Sb
Highly-Efficient Longitudinal Second-Harmonic Generation from Doubly-Resonant AlGaAs Nanoantennas
Publisher: MDPI AG
Date: 17-09-2018
Abstract: We design an asymmetric nonlinear optical nanoantenna composed of a dielectric nanodisc and an adjacent nanobar. The proposed composite structure made of AlGaAs exhibits resonant response at both the fundamental and doubled frequencies. Being driven by the strong magnetic dipole resonance at the pump wavelength and a high-quality mode at the harmonic wavelength, the efficient second-harmonic radiation is generated predominantly along the vertical directions under the normally incident plane-wave excitation.
Photonic Fractal Metamaterials: A Metal–Semiconductor Platform with Enhanced Volatile‐Compound Sensing Performance
Publisher: Wiley
Date: 22-10-2020
Nonlinear frequency conversion in optical nanoantennas and metasurfaces: materials evolution and fabrication
Publisher: Opto-Electronic Advances
Date: 2018
Exploiting plasmonics for THz and infrared sensing
Publisher: SPIE
Date: 21-05-2014
DOI: 10.1117/12.2053242
Influence of plasmon destructive interferences on optical properties of gold planar quadrumers
Publisher: IOP Publishing
Date: 04-05-2011
DOI: 10.1088/0957-4484/22/24/245204
Abstract: Arrays of planar symmetric gold quadrumers consisting of a central nano-disc surrounded by three similar nano-discs belonging to the D(3h) point group were designed and fabricated. Since the geometrical configuration of quadrumers is the same as planar trigonal molecules, nano-discs can play the roles of artificial atoms to study the coupling trends among them. The plasmonic properties of the nano-disc structures are investigated by reflection spectrum measurement and finite-difference time-domain calculation with good agreement. Plasmon interaction among the nano-discs is also studied via a mass-spring coupled oscillator model. A pronounced Fano resonance (FR) is observed for the fabricated nano-discs with inter-disk gaps of around 18 nm during light irradiation at normal incidence. Although the obtained FR is independent of the excitation polarization, the near-field energy spatial distribution can be flexibly tuned by the polarization direction. This has potential applications in nano-lithography, optical switching and nonlinear spectroscopy.
Nanostructured Dielectric Fractals on Resonant Plasmonic Metasurfaces for Selective and Sensitive Optical Sensing of Volatile Compounds
Publisher: Wiley
Date: 04-06-2018
Abstract: Advances in the understanding and fabrication of plasmonic nanostructures have led to a plethora of unprecedented optoelectronic and optochemical applications. Plasmon resonance has found widespread use in efficient optical transducers of refractive index changes in liquids. However, it has proven challenging to translate these achievements to the selective detection of gases, which typically adsorb non-specifically and induce refractive index changes below the detection limit. Here, it's shown that integration of tailored fractals of dielectric TiO
Split-ball resonator as a three-dimensional analogue of planar split-rings
Publisher: Springer Science and Business Media LLC
Date: 16-01-2014
DOI: 10.1038/NCOMMS4104
Abstract: Split-ring resonators are basic elements of metamaterials, which can induce a magnetic response in metallic nanosctructures. Tunability of such response up to the visible frequency range is still a challenge. Here we introduce the concept of the split-ball resonator and demonstrate the strong magnetic response in the visible for both gold and silver spherical plasmonic nanoparticles with nanometre scale cuts. We realize this concept experimentally by employing the laser-induced transfer method to produce near-perfect metallic spheres and helium ion beam milling to make cuts with the clean straight sidewalls and nanometre resolution. The magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. This method can be applied to the structuring of arbitrary three-dimensional features on the surface of nanoscale resonators. It provides new ways for engineering hybrid resonant modes and ultra-high near-field enhancement.
Bound States in the Continuum in Asymmetric Dielectric Metasurfaces
Publisher: Wiley
Date: 27-12-2022
Abstract: It is well established that for symmetry‐protected bound states in the continuum (BICs), introducing the broken geometry symmetry in a dielectric metasurface transforms such a BIC into a quasi‐BIC (QBIC) with high‐quality factor (Q‐factor). Typically, the smaller the asymmetry parameter, the larger the Q‐factor. However, it is very challenging to fabricate such nanostructures with an ultra‐small asymmetry parameter, thus limiting the measured Q‐factor of QBIC. In this work, the authors demonstrated that BICs can be sustained at Γ‐point in an asymmetric dielectric metasurface, whose unit cell is composed of a dielectric cuboid with an off‐centre hole inside it. Multipole decompositions and near‐field distributions indicate that the toroidal dipole dominates the nature of such a QBIC. Furthermore, the authors found that such a BIC is robust against the shape of the hole. Besides, two BICs at different wavelengths can be achieved by applying either a rectangular hole or a rectangular lattice. Finally, the authors presented experimental verifications of BIC types by fabricating asymmetric silicon metasurfaces. Measurement results show that the Q‐factor of QBIC can reach almost 5,000. The results may enrich the library of BICs and find exciting applications in developing high‐performance photonics devices, such as nanolasers, biosensors and enhanced nonlinear harmonic generation.
High‐Temperature Large‐Scale Self‐Assembly of Highly Faceted Monocrystalline Au Metasurfaces
Publisher: Wiley
Date: 20-11-2019
Tunable unidirectional nonlinear emission from transition-metal-dichalcogenide metasurfaces
Publisher: Springer Science and Business Media LLC
Date: 22-09-2021
DOI: 10.1038/S41467-021-25717-X
Abstract: Nonlinear light sources are central to a myriad of applications, driving a quest for their miniaturisation down to the nanoscale. In this quest, nonlinear metasurfaces hold a great promise, as they enhance nonlinear effects through their resonant photonic environment and high refractive index, such as in high-index dielectric metasurfaces. However, despite the sub-diffractive operation of dielectric metasurfaces at the fundamental wave, this condition is not fulfilled for the nonlinearly generated harmonic waves, thereby all nonlinear metasurfaces to date emit multiple diffractive beams. Here, we demonstrate the enhanced single-beam second- and third-harmonic generation in a metasurface of crystalline transition-metal-dichalcogenide material, offering the highest refractive index. We show that the interplay between the resonances of the metasurface allows for tuning of the unidirectional second-harmonic radiation in forward or backward direction, not possible in any bulk nonlinear crystal. Our results open new opportunities for metasurface-based nonlinear light-sources, including nonlinear mirrors and entangled-photon generation.
Selective Third-Harmonic Generation by Structured Light in Mie-Resonant Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 15-12-2018
Second order nonlinear frequency generation at the nanoscale in dielectric platforms
Publisher: Informa UK Limited
Date: 13-01-2022
Synthetic Plasmonic Nanocircuits and the Evolution of Their Correlated Spatial Arrangement and Resonance Spectrum
Publisher: American Chemical Society (ACS)
Date: 23-12-2020
Nonlinear Anisotropic Dielectric Metasurfaces for Ultrafast Nanophotonics
Publisher: American Chemical Society (ACS)
Date: 09-2017
Polarisation-independent enhanced scattering by tailoring asymmetric plasmonic systems
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR00029K
Abstract: Polarised light provides an efficient way for dynamic control over local optical properties of nanoscale plasmonic structures. Yet many applications that utilise control over the plasmonic near-field would benefit if the plasmonic device maintained the same magnitude of optical response for all polarisations. Here we show that completely asymmetric nanostructures can be designed to exhibit a broadband polarisation-independent and enhanced optical response. We provide both analytical and experimental results on two sets of plasmonic trimer nanostructures consisting of unequal nanodisks/apertures with different gap spacing. We show that, at certain inter-particle separations, enhanced far-field cross sections are independent to the incident polarisation, while still demonstrating nontrivial near-field control.
Realization of Variable Three-Dimensional Terahertz Metamaterial Tubes for Passive Resonance Tunability
Publisher: Wiley
Date: 22-03-2012
Edge Detection with Mie-Resonant Dielectric Metasurfaces
Publisher: American Chemical Society (ACS)
Date: 16-02-2021
Tailored Hypersound Generation in Single Plasmonic Nanoantennas
Publisher: American Chemical Society (ACS)
Date: 02-2016
DOI: 10.1021/ACS.NANOLETT.5B04991
Abstract: Ultrashort laser pulses impinging on a plasmonic nanostructure trigger a highly dynamic scenario in the interplay of electronic relaxation with lattice vibrations, which can be experimentally probed via the generation of coherent phonons. In this Letter, we present studies of hypersound generation in the range of a few to tens of gigahertz on single gold plasmonic nanoantennas, which have additionally been subjected to predesigned mechanical constraints via silica bridges. Using these hybrid gold/silica nanoantennas, we demonstrate experimentally and via numerical simulations how mechanical constraints allow control over their vibrational mode spectrum. Degenerate pump-probe techniques with double modulation are performed in order to detect the small changes produced in the probe transmission by the mechanical oscillations of these single nanoantennas.
Tailoring Second-Harmonic Emission from (111)-GaAs Nanoantennas
Publisher: American Chemical Society (ACS)
Date: 28-05-2019
DOI: 10.1021/ACS.NANOLETT.9B01112
Abstract: Second-harmonic generation (SHG) in resonant dielectric Mie-scattering nanoparticles has been hailed as a powerful platform for nonlinear light sources. While bulk-SHG is suppressed in elemental semiconductors, for ex le, silicon and germanium due to their centrosymmetry, the group of zincblende III-V compound semiconductors, especially (100)-grown AlGaAs and GaAs, have recently been presented as promising alternatives. However, major obstacles to push the technology toward practical applications are the limited control over directionality of the SH emission and especially zero forward/backward radiation, resulting from the peculiar nature of the second-order nonlinear susceptibility of this otherwise highly promising group of semiconductors. Furthermore, the generated SH signal for (100)-GaAs nanoparticles depends strongly on the polarization of the pump. In this work, we provide both theoretically and experimentally a solution to these problems by presenting the first SHG nanoantennas made from (111)-GaAs embedded in a low index material. These nanoantennas show superior forward directionality compared to their (100)-counterparts. Most importantly, based on the special symmetry of the crystalline structure, it is possible to manipulate the SHG radiation pattern of the nanoantennas by changing the pump polarization without affecting the linear properties and the total nonlinear conversion efficiency, hence paving the way for efficient and flexible nonlinear beam-shaping devices.
Correction to “Tailored Hypersound Generation in Single Plasmonic Nanoantennas”
Publisher: American Chemical Society (ACS)
Date: 24-02-2016
Electrically-tunable solid-state metasurfaces via flash localised heating
Publisher: Research Square Platform LLC
Date: 24-05-2022
DOI: 10.21203/RS.3.RS-1665364/V1
Abstract: Metasurfaces have recently realised many revolutionary applications such as metalenses, equation solvers, beam shapers, and holographic projection.1–4 However, the conventional metasurfaces are monotask due to their fixed dimensions. Therefore, realising multitask metasurfaces for applications such as beam steering, optical switches and meta-displays, which require fast and dynamic reconfigurability, has bottlenecked. To address this technological challenge, there has been a quest to enable tunability via mechanical tilting or stretching the s les, rotating the illumination angle or the incident light polarisation, use of chemical reactions, and others.5–8 However, most of these approaches still suffer from slow tuning rate, weak modulation, and bulky or non-solid state components. Here, we introduce electrically tunable metasurfaces that offer up to 9 folds surge in transmission, i.e. 90% transmission modulation depth, with switching time µs, i.e. one order of magnitude faster than video frame rates. To realise such a breakthrough, we have driven the designed metasurface by V spiked voltage, asymmetrically, for the first time in optoelectronics.
Non-plasmonic nanoantennas for surface enhanced spectroscopies with ultra-low heat conversion
Publisher: Springer Science and Business Media LLC
Date: 04-08-2015
DOI: 10.1038/NCOMMS8915
Abstract: Nanoplasmonics has recently revolutionized our ability to control light on the nanoscale. Using metallic nanostructures with tailored shapes, it is possible to efficiently focus light into nanoscale field ‘hot spots’. High field enhancement factors have been achieved in such optical nanoantennas, enabling transformative science in the areas of single molecule interactions, highly enhanced nonlinearities and nanoscale waveguiding. Unfortunately, these large enhancements come at the price of high optical losses due to absorption in the metal, severely limiting real-world applications. Via the realization of a novel nanophotonic platform based on dielectric nanostructures to form efficient nanoantennas with ultra-low light-into-heat conversion, here we demonstrate an approach that overcomes these limitations. We show that dimer-like silicon-based single nanoantennas produce both high surface enhanced fluorescence and surface enhanced Raman scattering, while at the same time generating a negligible temperature increase in their hot spots and surrounding environments.
Nonlinear Symmetry Breaking in Symmetric Oligomers
Publisher: American Chemical Society (ACS)
Date: 16-02-2017
Deeply Subwavelength Metasurface Resonators for Terahertz Wavefront Manipulation
Publisher: Wiley
Date: 13-08-2019
Localized Nanopore Fabrication via Controlled Breakdown
Publisher: MDPI AG
Date: 12-07-2022
DOI: 10.3390/NANO12142384
Abstract: Nanopore sensors provide a unique platform to detect in idual nucleic acids, proteins, and other biomolecules without the need for fluorescent labeling or chemical modifications. Solid-state nanopores offer the potential to integrate nanopore sensing with other technologies such as field-effect transistors (FETs), optics, plasmonics, and microfluidics, thereby attracting attention to the development of commercial instruments for diagnostics and healthcare applications. Stable nanopores with ideal dimensions are particularly critical for nanopore sensors to be integrated into other sensing devices and provide a high signal-to-noise ratio. Nanopore fabrication, although having benefited largely from the development of sophisticated nanofabrication techniques, remains a challenge in terms of cost, time consumption and accessibility. One of the latest developed methods—controlled breakdown (CBD)—has made the nanopore technique broadly accessible, boosting the use of nanopore sensing in both fundamental research and biomedical applications. Many works have been developed to improve the efficiency and robustness of pore formation by CBD. However, nanopores formed by traditional CBD are randomly positioned in the membrane. To expand nanopore sensing to a wider biomedical application, controlling the localization of nanopores formed by CBD is essential. This article reviews the recent strategies to control the location of nanopores formed by CBD. We discuss the fundamental mechanism and the efforts of different approaches to confine the region of nanopore formation.
Resonant harmonic generation in AlGaAs nanoantennas probed by cylindrical vector beams
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NR08034H
Abstract: Cylindrical vector beams with radial and azimuthal polarizations are used to study harmonic generation from in idual AlGaAs nanoantennas.
Beyond the Hybridization Effects in Plasmonic Nanoclusters: Diffraction-Induced Enhanced Absorption and Scattering
Publisher: Wiley
Date: 03-09-2013
Abstract: It is demonstrated herein both theoretically and experimentally that Young's interference can be observed in plasmonic structures when two or three nanoparticles with separation on the order of the wavelength are illuminated simultaneously by a plane wave. This effect leads to the formation of intermediate-field hybridized modes with a character distinct of those mediated by near-field and/or far-field radiative effects. The physical mechanism for the enhancement of absorption and scattering of light due to plasmonic Young's interference is revealed, which we explain through a redistribution of the Poynting vector field and the formation of near-field subwavelength optical vortices.
The Interplay of Symmetry and Scattering Phase in Second Harmonic Generation from Gold Nanoantennas
Publisher: American Chemical Society (ACS)
Date: 26-07-2016
DOI: 10.1021/ACS.NANOLETT.6B02485
Abstract: Nonlinear phenomena are central to modern photonics but, being inherently weak, typically require gradual accumulation over several millimeters. For ex le, second harmonic generation (SHG) is typically achieved in thick transparent nonlinear crystals by phase-matching energy exchange between light at initial, ω, and final, 2ω, frequencies. Recently, metamaterials imbued with artificial nonlinearity from their constituent nanoantennas have generated excitement by opening the possibility of wavelength-scale nonlinear optics. However, the selection rules of SHG typically prevent dipole emission from simple nanoantennas, which has led to much discussion concerning the best geometries, for ex le, those breaking centro-symmetry or incorporating resonances at multiple harmonics. In this work, we explore the use of both nanoantenna symmetry and multiple harmonics to control the strength, polarization and radiation pattern of SHG from a variety of antenna configurations incorporating simple resonant elements tuned to light at both ω and 2ω. We use a microscopic description of the scattering strength and phases of these constituent particles, determined by their relative positions, to accurately predict the SHG radiation observed in our experiments. We find that the 2ω particles radiate dipolar SHG by near-field coupling to the ω particle, which radiates SHG as a quadrupole. Consequently, strong linearly polarized dipolar SHG is only possible for noncentro-symmetric antennas that also minimize interference between their dipolar and quadrupolar responses. Metamaterials with such intra-antenna phase and polarization control could enable compact nonlinear photonic nanotechnologies.
Theory, Observation, and Ultrafast Response of the Hybrid Anapole Regime in Light Scattering
Publisher: Wiley
Date: 02-08-2021
Abstract: Modern nanophotonics has witnessed the rise of “electric anapoles” (EDAs), destructive interferences of electric and toroidal electric dipoles, actively exploited to resonantly decrease radiation from nanoresonators. However, the inherent duality in Maxwell equations suggests the intriguing possibility of “magnetic anapoles,” involving a nonradiating composition of a magnetic dipole and a magnetic toroidal dipole. Here, a hybrid anapole (HA) of mixed electric and magnetic character is predicted and observed experimentally via dark field spectroscopy, with all the dominant multipoles being suppressed by the toroidal terms in a nanocylinder. Breaking the spherical symmetry allows to overlap up to four anapoles stemming from different multipoles with just two tuning parameters. This effect is due to a symmetry‐allowed connection between the resonator multipolar response and its eigenstates. The authors delve into the physics of such current configurations in the stationary and transient regimes and explore new ultrafast phenomena arising at sub‐picosecond timescales, associated with the HA dynamics. The theoretical results allow the design of non‐Huygens metasurfaces featuring a dual functionality: perfect transparency in the stationary regime and controllable ultrashort pulse beatings in the transient. Besides offering significant advantages with respect to EDAs, HAs can play an essential role in developing the emerging field of ultrafast resonant phenomena.
Subgroup Decomposition of Plasmonic Resonances in Hybrid Oligomers: Modeling the Resonance Lineshape
Publisher: American Chemical Society (ACS)
Date: 29-03-2012
DOI: 10.1021/NL3003683
Abstract: Plasmonic resonances with a Fano lineshape observed in metallic nanoclusters often arise from the destructive interference between a dark, subradiant mode and a bright, super-radiant one. A flexible control over the Fano profile characterized by its linewidth and spectral contrast is crucial for many potential applications such as slowing light and biosensing. In this work, we show how one can easily but significantly tailor the overall spectral profile in plasmonic nanocluster systems, for ex le, quadrumers and pentamers, by selectively altering the particle shape without a need to change the particle size, interparticle distance, or the number of elements of the oligomers. This is achieved through decomposing the whole spectrum into two separate contributions from subgroups, which are efficiently excited at their spectral peak positions. We further show that different strengths of interference between the two subgroups must be considered for a full understanding of the resulting spectral lineshape. In some cases, each subgroup is separately active in distinct frequency windows with only small overlap, leading to a simple convolution of the subspectra. Variation in particle shape of either subgroup results in the tuning of the overall spectral lineshape, which opens a novel pathway for shaping the plasmonic response in small nanoclusters.
Polarization-controlled spatial localization of near-field energy in planar symmetric coupled oligomers
Publisher: Springer Science and Business Media LLC
Date: 22-12-2011
Dynamic Nonlinear Image Tuning through Magnetic Dipole Quasi‐BIC Ultrathin Resonators
Publisher: Wiley
Date: 23-05-2019
Plasmonic linear nanomotor using lateral optical forces
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-11-2020
Abstract: A nanoscale metal particle functions as a light-powered linear motor via engineering its localized surface plasmons.
Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.ENVPOL.2015.08.015
Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment (ii) evaluate their toxicity and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air s les collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas.
Quasi-bound states in the continuum with a stable resonance wavelength in dimer dielectric metasurfaces
Publisher: Walter de Gruyter GmbH
Date: 05-2023
Abstract: Symmetry-protected bound states in the continuum (SP-BICs) are one of the most intensively studied BICs. Typically, SP-BICs must be converted into quasi-BICs (QBICs) by breaking the unit cell’s symmetry so that they can be accessed by the external excitation. The symmetry-broken usually results in a varied resonance wavelength of QBICs which are also highly sensitive to the asymmetry parameters. In this work, we demonstrate that QBICs with a stable resonance wavelength can be realized by breaking translational symmetry in an all-dielectric metasurface. The unit cell of metasurface is made of a silicon nanodisk dimer. The Q-factor of QBICs is precisely tuned by changing the interspacing of two nanodisks while their resonance wavelength is quite stable against the interspacing. We also find that such BICs show weak dependence on the shape of the nanodisk. Multiple decompositions indicate that the toroidal dipole dominates this type of QBIC. The resonance wavelengths of QBICs can be tuned only by changing either the lattice constants or the radius of nanodisk. Finally, we present experimental demonstrations on such a QBIC with a stable resonance wavelength. The highest measured Q-factor of QBICs is . Our results may find promising applications in enhancing light–matter interaction.
Infrared upconversion imaging in nonlinear metasurfaces
Publisher: SPIE-Intl Soc Optical Eng
Date: 15-06-2021
Planar narrow bandpass filter based on Si resonant metasurface
Publisher: AIP Publishing
Date: 05-08-2021
DOI: 10.1063/5.0058768
Abstract: Optically resonant dielectric metasurfaces offer unique capability to fully control the wavefront, polarization, intensity, or spectral content of light based on the excitation and interference of different electric and magnetic Mie multipolar resonances. Recent advances of the wide accessibility in nanofabrication and nanotechnologies have led to a surge in the research field of high-quality functional optical metasurfaces, which can potentially replace or even outperform conventional optical components with ultra-thin features. Replacing conventional optical filtering components with metasurface technology offers remarkable advantages, including lower integration cost, ultra-thin compact configuration, easy combination with multiple functions, and less restriction on materials. Here, we propose and experimentally demonstrate a planar narrow bandpass filter based on the optical dielectric metasurface composed of Si nanoresonators in arrays. A broadband transmission spectral valley (around 200 nm) has been realized by combining electric and magnetic dipole resonances adjacent to each other. Meanwhile, we obtain a narrow-band transmission peak by exciting a high-quality leaky mode, which is formed by partially breaking a bound state in the continuum generated by the collective longitudinal magnetic dipole resonances in the metasurface. Owing to the in-plane inversion symmetry of our nanostructure, the radiation of this antisymmetric mode is inhibited at far field, manifesting itself a sharp Fano-shape peak in the spectrum. Our proposed metasurface-based filter shows a stable performance for oblique light incidence with small angles (within 10°). Our work implies many potential applications of nanoscale photonics devices, such as displays, spectroscopy, etc.
Hybrid Metasurface Based Tunable Near-Perfect Absorber and Plasmonic Sensor
Publisher: MDPI AG
Date: 27-06-2018
DOI: 10.3390/MA11071091
Generation of pronounced Fano resonances and tuning of subwavelength spatial light distribution in plasmonic pentamers
Publisher: The Optical Society
Date: 03-2011
DOI: 10.1364/OE.19.004949
Third Harmonic Generation Enhanced by Multipolar Interference in Complementary Silicon Metasurfaces
Publisher: American Chemical Society (ACS)
Date: 02-2018
Optical Monitoring of In Situ Iron Loading into Single, Native Ferritin Proteins
Publisher: American Chemical Society (ACS)
Date: 13-04-2023
Programmable structured surfaces can change the future of wireless communications
Publisher: Springer Science and Business Media LLC
Date: 28-06-2022
DOI: 10.1038/S41377-022-00878-6
Abstract: An innovative time-varying metasurface has been reported to realise dual-channel data transmissions for light-to-microwave signal conversion. Such a novel technique is a remarkable step forward to realise full-spectrum networks for catering for the growing demand for wireless communications. Moreover, this technique enriches the functionalities of tunable metasurfaces and stimulates new information-oriented applications.
Multiresonant Broadband Optical Antennas As Efficient Tunable Nanosources of Second Harmonic Light
Publisher: American Chemical Society (ACS)
Date: 27-08-2012
DOI: 10.1021/NL302665M
Abstract: We report the experimental realization of efficient tunable nanosources of second harmonic light with in idual multiresonant log-periodic optical antennas. By designing the nanoantenna with a bandwidth of several octaves, simultaneous enhancement of fundamental and harmonic fields is observed over a broad range of frequencies, leading to a high second harmonic conversion efficiency, together with an effective second order susceptibility within the range of values provided by widespread inorganic crystals. Moreover, the geometrical configuration of the nanoantenna makes the generated second harmonic signal independent from the polarization of the fundamental excitation. These results open new possibilities for the development of efficient integrated nonlinear nanodevices with high frequency tunability.
A Search Space Reduction Strategy and a Mathematical Model for Multistage Transmission Expansion Planning with $$N-1$$ N - 1 Security Constrains
Publisher: Springer Science and Business Media LLC
Date: 30-09-2014
High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces
Publisher: Beilstein Institut
Date: 06-02-2018
DOI: 10.3762/BJNANO.9.44
Abstract: Novel types of optical hybrid metasurfaces consist of metallic and dielectric elements are designed and proposed for controlling the interference between magnetic and electric modes of the system, in a reversible manner. By employing the thermo-optical effect of silicon and gold nanoantennas we demonstrate an active control on the excitation and interference between electric and magnetic modes, and subsequently, the Kerker condition, as a directive radiation pattern with zero backscattering, via temperature control as a versatile tool. This control allows precise tuning optical properties of the system and stimulating switchable sharp spectral Fano-like resonance. Furthermore, it is shown that by adjusting the intermediate distance between metallic and dielectric elements, opposite scattering directionalities are achievable in an arbitrary wavelength. Interestingly, this effect is shown to have a direct influence on nonlinear properties, too, where 10-fold enhancement in the intensity of third harmonic light can be obtained for this system, via heating. This hybrid metasurface can find a wide range of applications in slow light, nonlinear optics and bio-chemical sensing.
Fano resonance in novel plasmonic nanostructures
Publisher: Wiley
Date: 23-07-2012
Related Organisations
National Technical University Of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”
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Imperial College London
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