ORCID Profile
0000-0003-2123-1345
Current Organisation
University of New South Wales
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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)
Classical Physics | Electrostatics and Electrodynamics | Photonics and Electro-Optical Engineering (excl. Communications) | Nanophotonics | Microwave and Millimetrewave Theory and Technology | Communications Technologies | Optical Physics | Interdisciplinary Engineering not elsewhere classified | Microelectronics and Integrated Circuits | Microelectromechanical Systems (MEMS) | Electrical and Electronic Engineering | Photonics, Optoelectronics and Optical Communications | Nonlinear Optics and Spectroscopy | Classical and Physical Optics | Acoustics and Acoustical Devices; Waves |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Engineering | Road Safety | Automotive Equipment | Emerging Defence Technologies | Expanding Knowledge in the Biological Sciences | Expanding Knowledge in Technology
Related Links
Publications
Chiral meta-atoms rotated by light
Publisher: AIP Publishing
Date: 16-07-2012
DOI: 10.1063/1.4737441
Abstract: We study the opto-mechanical properties of coupled chiral meta-atoms based on a pair of twisted split-ring resonators. By using a simple analytical model in conjunction with the Maxwell stress tensor, we capture insight into the mechanism and find that this structure can be used as a general prototype of subwavelength light-driven actuators over a wide range of frequencies. This coupled structure can provide a strong and tunable torque, and can support different opto-mechanical modes, including uniform rotation, periodically variable rotation and d ed oscillations. Our results suggest that chiral meta-atoms are good candidates for creating sub-wavelength motors or wrenches controlled by light.
Tilted response of fishnet metamaterials at near-infrared optical wavelengths
Publisher: American Physical Society (APS)
Date: 05-03-2010
Circular dichroism of four-wave mixing in nonlinear metamaterials
Publisher: American Physical Society (APS)
Date: 25-11-2013
Nonlinear response via intrinsic rotation in metamaterials
Publisher: American Physical Society (APS)
Date: 20-06-2013
A Terahertz gradient metasurface based on hybridized dipole andquadrupole resonances
Publisher: IOP Publishing
Date: 24-11-2020
Graphene metasurfaces for arbitrary wavefront control
Publisher: IEEE
Date: 10-2017
Fast tunable terahertz absorber based on a MEMS-driven metamaterial
Publisher: OSA
Date: 2017
Linear and nonlinear coupling in metamaterials
Publisher: IEEE
Date: 09-2012
Self-tuning mechanisms of nonlinear split-ring resonators
Publisher: AIP Publishing
Date: 10-2007
DOI: 10.1063/1.2794733
Abstract: We study both theoretically and experimentally the dynamic tunability of the magnetic resonance of a single nonlinear split-ring resonator with varactor diode at microwave frequencies. We demonstrate different tuning regimes with and without an inductive coil in parallel with the varactor. We show that the coil changes the sign of the nonlinearity and eliminates the memory effect caused by charge accumulation across the varactor. In addition, at higher powers the nonlinear response of the split-ring resonator becomes multivalued, paving a way for creating bistable tunable metamaterials.
Acoustofluidics 24: theory and experimental measurements of acoustic interaction force
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2LC00447J
Abstract: This tutorial review covers theoretical and experimental aspects of acoustic interaction force, as one of the driving forces of acoustophoresis. The non-reciprocity, rotational coupling, viscosity effects, and particle agglomeration are discussed.
Observation of tunneling of slow and fast electromagnetic modes in coupled periodic waveguides
Publisher: AIP Publishing
Date: 07-02-2011
DOI: 10.1063/1.3553785
Abstract: We report the experimental observation of tunneling of slow and fast electromagnetic modes in coupled periodic waveguides shifted longitudinally by half of modulation period. According to the symmetry analysis, such a coupler supports two electromagnetic modes with exactly matched slow or fast group velocities but different phase velocities for frequencies close to the edge of the photonic band. We confirm the predicted properties of the modes by directly extracting their dispersion and group velocities from the near-field measurements using specialized Bloch-wave spectral analysis method.
Willis Coupling-Induced Acoustic Radiation Force and Torque Reversal
Publisher: American Physical Society (APS)
Date: 17-10-2022
Realistic prediction and engineering of high-Q modes to implement stable Fano resonances in acoustic devices
Publisher: Springer Science and Business Media LLC
Date: 27-10-2023
Pneumatically switchable graded index metamaterial lens
Publisher: AIP Publishing
Date: 21-01-2013
DOI: 10.1063/1.4788918
Abstract: A low-profile pneumatically switchable graded index metamaterial lens operating at 9 GHz is proposed and practically demonstrated. An effective graded refractive index is engineered using an array of electric resonators of differing resonant frequency. Normal orientation of the resonators allows ultrathin single metamaterial layer lens design. Switching between focusing and non-focusing states is practically demonstrated by shorting the gaps in split ring resonators and eliminating the resonant response and the phase difference between the elements across the lens with pneumatically actuated metal patches that are pressed against the gaps of the resonators as the pressure in the chamber is reduced.
Metamaterial tuning by manipulation of near-field interaction
Publisher: American Physical Society (APS)
Date: 19-10-2010
Electroactive Tuning of Double‐Layered Metamaterials Based on π‐Conjugated Polymer Actuators
Publisher: Wiley
Date: 05-10-2015
Light coupling in microwave metamaterials
Publisher: IEEE
Date: 09-2013
Microacoustic Metagratings at Ultra‐High Frequencies Fabricated by Two‐Photon Lithography
Publisher: Wiley
Date: 24-04-2022
Abstract: The recently proposed bianisotropic acoustic metagratings offer promising opportunities for passive acoustic wavefront manipulation, which is of particular interest in flat acoustic lenses and ultrasound imaging at ultra‐high frequency ultrasound. Despite this fact, acoustic metagratings have never been scaled to MHz frequencies that are common in ultrasound imaging. One of the greatest challenges is the production of complex microscopic structures. Owing to two‐photon polymerization, a novel fabrication technique from the view of acoustic metamaterials, it is now possible to precisely manufacture sub‐wavelength structures in this frequency range. However, shrinking in size poses another challenge the increasing thermoviscous effects lead to a drop in efficiency and a frequency downshift of the transmission peak and must therefore be taken into account in the design. In this work three microacoustic metagrating designs refracting a normally incident wave toward −35° at 2 MHz are proposed. In order to develop meta‐atoms insensitive to thermoviscous effects shape optimization techniques incorporating the linearized Navier–Stokes equations discretized with finite element method are used. The authors report for the first time microscopic acoustic metamaterials manufactured using two‐photon polymerization and, subsequently, experimentally verify their effectiveness using an optical microphone as a detector in a range from 1.8 to 2.2 MHz.
Comparison of layered based SAW sensors
Publisher: Elsevier BV
Date: 06-2003
Optimization of film thickness for thermoelectric micro-Peltier cooler
Publisher: SPIE
Date: 28-02-2005
DOI: 10.1117/12.582256
Scalable Metagrating for Efficient Ultrasonic Focusing
Publisher: American Physical Society (APS)
Date: 06-12-2021
Optical activity and coupling in twisted dimer meta-atoms
Publisher: AIP Publishing
Date: 12-03-2012
DOI: 10.1063/1.3694269
Abstract: We analyse the optical activity in twisted dimers, the meta-atoms of a chiral metamaterial, by introducing a simple yet accurate model for the coupling between them. The near-field interaction coefficients are derived from a Lagrangian model and include the effects of retardation, whereas the far-field radiation is based on a multipole expansion. We show that the optimum twist angle varies with frequency, and near resonance is substantially lower than 45 degrees, which is the lowest symmetry configuration. Our approach is accurate over a wide frequency range, including the resonant regions with the highest optical activity. In contrast to other models of near-field interaction, it requires no fitted parameters or homogenization procedure and is directly applicable to a wide variety of resonant particles.
A study of CO sensors with oscillatory response
Publisher: Elsevier BV
Date: 12-2003
Sound trapping in an open resonator
Publisher: Springer Science and Business Media LLC
Date: 10-08-2021
DOI: 10.1038/S41467-021-25130-4
Abstract: The ability of sound energy confinement with high-quality factor resonance is of vital importance for acoustic devices requiring high intensity and hypersensitivity in biological ultrasonics, enhanced collimated sound emission (i.e. sound laser) and high-resolution sensing. However, structures reported so far have been experimentally demonstrated with a limited quality factor of acoustic resonances, up to several tens in an open resonator. The emergence of bound states in the continuum makes it possible to realize high quality factor acoustic modes. Here, we report the theoretical design and experimental demonstration of acoustic bound states in the continuum supported by a single open resonator. We predicted that such an open acoustic resonator could simultaneously support three types of bound states in the continuum, including symmetry protected bound states in the continuum, Friedrich-Wintgen bound states in the continuum induced by mode interference, as well as a new type-mirror symmetry induced bound states in the continuum. We also experimentally demonstrated their existence with quality factor up to one order of magnitude greater than the highest quality factor reported in an open resonator.
High-Efficiency Refracting Millimeter-Wave Metasurfaces
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2020
Polarization phenomena in periodic metasurfaces at oblique incidence
Publisher: IEEE
Date: 08-2014
Infrared metamaterials tuned by liquid crystals
Publisher: IEEE
Date: 12-2010
Multistability in nonlinear left-handed transmission lines
Publisher: AIP Publishing
Date: 30-06-2008
DOI: 10.1063/1.2955531
Abstract: Employing a nonlinear left-handed transmission line as a model system, we demonstrate experimentally the multistability phenomena predicted theoretically for microstructured left-handed metamaterials with a nonlinear response. We show that the bistability is associated with the period doubling, which at higher power may result in chaotic dynamics of the transmission line.
Accurate Metasurface Synthesis Incorporating Near-Field Coupling Effects
Publisher: American Physical Society (APS)
Date: 04-06-2019
Bandwidth and Size Limits of Achromatic Printed-Circuit Metasurfaces
Publisher: The Optical Society
Date: 26-10-2018
DOI: 10.1364/OE.26.029440
Terahertz focusing of multiple wavelengths by graphene metasurfaces
Publisher: AIP Publishing
Date: 18-01-2016
DOI: 10.1063/1.4940231
Abstract: Metasurfaces can achieve nearly arbitrary wavefront control based on manipulation of the wave phase profile. We propose a metasurface based on double graphene cut-wire resonators which can cover the complete 2π phase region with high reflection efficiency. This full phase coverage is essential for efficient wavefront manipulation, without reflecting energy into unwanted channels. A mirror capable of focusing multiple wavelengths is demonstrated numerically based on the proposed structure. The mirror can effectively focus terahertz (THz) waves from 1.2 to 1.9 THz to the same focal point by changing the Fermi level of each graphene resonator separately. The presented metasurface could provide a powerful platform for controlling THz waves, including focusing, beam steering, beam shaping, and holography.
Coupled Electromagnetic and Elastic Dynamics in Metamaterials
Publisher: Springer International Publishing
Date: 02-11-2014
Photosensitive SRR-metamaterials
Publisher: IEEE
Date: 07-2013
Achromatic Huygens’ Metalenses with Deeply Subwavelength Thickness
Publisher: Wiley
Date: 03-09-2020
Substrate-induced bianisotropy in metamaterials
Publisher: AIP Publishing
Date: 30-08-2010
DOI: 10.1063/1.3486480
Abstract: We demonstrate that the presence of a supporting substrate can break the symmetry of a metamaterial structure, changing the symmetry of its effective parameters, and giving rise to bianisotropy. This indicates that magnetoelectric coupling will occur in all metamaterials fabricated on a substrate, including those with symmetric designs.
Dispersion extraction with near-field measurements in periodic waveguides
Publisher: The Optical Society
Date: 25-02-2009
DOI: 10.1364/OE.17.003716
Abstract: We formulate and demonstrate experimentally the high-resolution spectral method based on Bloch-wave symmetry properties for extracting mode dispersion in periodic waveguides from measurements of near-field profiles. We characterize both the propagating and evanescent modes, and also determine the litudes of forward and backward waves in different waveguide configurations, with the estimated accuracy of several percent or less. Whereas the commonly employed spatial Fourier-transform (SFT) analysis provides the wavenumber resolution which is limited by the inverse length of the waveguide, we achieve precise dispersion extraction even for compact photonic structures.
Analysing and manipulating near-field interaction in metamaterials
Publisher: IEEE
Date: 09-2010
Measuring monopole and dipole polarizability of acoustic meta-atoms
Publisher: AIP Publishing
Date: 26-11-2018
DOI: 10.1063/1.5052661
Abstract: We present a method to extract monopole and dipole polarizability from experimental measurements of two-dimensional acoustic meta-atoms. In contrast to extraction from numerical results, this enables all second-order effects and uncertainties in material properties to be accounted for. We apply the technique to 3D-printed labyrinthine meta-atoms of a variety of geometries. We show that the polarizability of structures with a shorter acoustic path length agrees well with numerical results. However, those with longer path lengths suffer strong additional d ing, which we attribute to the strong viscous and thermal losses in narrow channels.
Elastic metamaterials for tuning circular polarization of electromagnetic waves
Publisher: Springer Science and Business Media LLC
Date: 20-06-2016
DOI: 10.1038/SREP28273
Abstract: Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.
Direct visualization of a Friedrich-Wintgen quasi-bound state in the continuum
Publisher: Research Square Platform LLC
Date: 23-05-2023
DOI: 10.21203/RS.3.RS-2311624/V1
Abstract: Bound states in the continuum (BICs) are a well known phenomenon in physics, particularly in quantum physics and wave physics. Since BICs are local states, their existence typically manifests as Fano resonances in the transmission or reflection spectrum. However, to date no direct or visual proof of an acoustic BIC has been reported. We demonstrate the existence of a Friedrich-Wintgen BIC in an open acoustic cavity by theory and experiments. The appearance of the BIC is characterized by the vanished line width of the Fano resonance in the measured transmission spectrum. Our theoretical predictions accurately match the experimental observations. We map the pressure field of the transparent open cavity hosting a Friedrich-Wintgen BIC using laser Doppler vibrometry, which is the first reported visualization of an acoustic BIC. Mapping the pressure field of the BIC is a new technique to extract real sound pressure values of high-Q modes. We can draw conclusions from the pressure values on the confinement of the BIC. Our results facilitate the future development of applications of BICs in the field of acoustics, as acoustic sources, filters, and sensors.
Bandwidth limit and synthesis approach for single resonance ultrathin metasurfaces
Publisher: IOP Publishing
Date: 06-10-2020
Abstract: Metasurfaces have emerged as a promising technology for the manipulation of electromagnetic waves within a thin layer. In planar ultrathin metasurfaces, there exist rigorous design methods, based on the equivalent surface impedance of patterned metallic layers on dielectric substrates. In this work, we derive a limit on bandwidth achievable in these metasurfaces, based on constraints that their meta-atoms should be passive, causal and lossless and that they should obey the time-bandwidth product rules of a single resonance structure. The results show that in addition to elementary design parameters involving variation of the surface impedance, the bandwidth is critically limited by the dielectric substrate thickness and permittivity. We then propose a synthesis method for broadband ultrathin metasurfaces, based on an LC resonance fit of the required surface impedance and experimentally verify a broadband dispersive structure at millimeter-wave frequencies. This results in a bandwidth enhancement of over 90%, relative to a reference metasurface created with the narrowband design process.
Tunable and nonlinear fishnet metamaterials based on liquid crystal infiltration
Publisher: SPIE
Date: 24-09-2012
DOI: 10.1117/12.931309
Nonlinear interaction of meta-atoms through optical coupling
Publisher: AIP Publishing
Date: 06-01-2014
DOI: 10.1063/1.4861388
Ultrathin tunable terahertz absorber based on MEMS-driven metamaterial
Publisher: Springer Science and Business Media LLC
Date: 28-08-2017
DOI: 10.1038/MICRONANO.2017.33
Abstract: The realization of high-performance tunable absorbers for terahertz frequencies is crucial for advancing applications such as single-pixel imaging and spectroscopy. Based on the strong position sensitivity of metamaterials’ electromagnetic response, we combine meta-atoms that support strongly localized modes with suspended flat membranes that can be driven electrostatically. This design maximizes the tunability range for small mechanical displacements of the membranes. We employ a micro-electro-mechanical system technology and successfully fabricate the devices. Our prototype devices are among the best-performing tunable THz absorbers demonstrated to date, with an ultrathin device thickness (~1/50 of the working wavelength), absorption varying between 60% and 80% in the initial state when the membranes remain suspended, and fast switching speed (~27 μs). The absorption is tuned by an applied voltage, with the most marked results achieved when the structure reaches the snap-down state. In this case, the resonance shifts by % of the linewidth (14% of the initial resonance frequency), and the absolute absorption modulation measured at the initial resonance can reach 65%. The demonstrated approach can be further optimized and extended to benefit numerous applications in THz technology.
Experimental studies of binary metamaterials
Publisher: IEEE
Date: 06-2007
Correcting the Fabry-Perot artifacts in metamaterial retrieval procedures
Publisher: American Physical Society (APS)
Date: 12-2011
Scattering of electromagnetic waves in metamaterial superlattices
Publisher: AIP Publishing
Date: 14-05-2007
DOI: 10.1063/1.2741148
Abstract: The authors study experimentally both transmission and reflection of microwave radiation from metamaterial superlattices created by layers of periodically arranged wires and split-ring resonators. The authors measure the dependence of the metamaterial resonance on the spatial period of the superlattice and demonstrate resonance broadening and splitting for the binary metamaterial structures.
Second harmonic generation with zero phase velocity waves
Publisher: AIP Publishing
Date: 18-04-2011
DOI: 10.1063/1.3580616
Abstract: We design a dual-band nonlinear composite right-left handed transmission line with phase-matching achieved between the fundamental frequency and second harmonic when both interacting waves have zero phase velocity. Additionally, we show that such a transmission line supports a new regime where the generation of backward second harmonic waves is achieved from a backward fundamental frequency wave.
Acoustic radiation force and radiation torque beyond particles: Effects of nonspherical shape and Willis coupling
Publisher: American Physical Society (APS)
Date: 15-12-2021
Near-field interaction of twisted split-ring resonators
Publisher: American Physical Society (APS)
Date: 15-06-2011
Influence of the substrate on negative index fishnet metamaterials
Publisher: Elsevier BV
Date: 12-2010
Femtosecond laser inscribed waveguide and micro-chip laser operation at 1.07μm in Yb3+ doped germanate glass
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539820
Comparison of conductometric gas sensitivity of surface acoustic wave modes in layered structures
Publisher: American Scientific Publishers
Date: 2005
DOI: 10.1166/SL.2005.011
Tuning the nonlinear response of coupled split-ring resonators
Publisher: AIP Publishing
Date: 20-02-2012
DOI: 10.1063/1.3689775
Abstract: We introduce the concept of controlling the nonlinear response of the metamaterial by altering its internal structure. We experimentally demonstrate tuning of the nonlinear response of two coupled split-ring resonators by changing their mutual position. This effect is achieved through modification of the structure of the coupled resonant modes and their interaction with the incident field. By offsetting the resonators we control the maximum currents through the nonlinear elements, which affect the nonlinear response of the system.
Characterization of Broadband Focusing Microwave Metasurfaces at Oblique Incidence
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2022
Interference between the Modes of an All-Dielectric Meta-atom
Publisher: American Physical Society (APS)
Date: 07-03-2017
Tunable Meta-Liquid Crystals
Publisher: Wiley
Date: 08-12-2015
Abstract: Meta-liquid crystals, a novel form of tunable 3D metamaterials, are proposed and experimentally demonstrated in the terahertz frequency regime. A morphology change under a bias electric field and a strong modulation of the transmission are observed. In comparison to conventional liquid crystals, there is considerable freedom to prescribe the electromagnetic properties through the judicious design of the meta-atom geometry.
Electromagnetic tuning of resonant transmission in magnetoelastic metamaterials
Publisher: AIP Publishing
Date: 21-04-2014
DOI: 10.1063/1.4873936
Abstract: We demonstrate an analogue of electromagnetically-induced transparency (EIT) in a magnetoelastic metamaterial system and experimentally realize nonlinear electromagnetic tuning of this EIT-like transmission. We study a single meta-molecule, consisting of two split-ring resonators (SRRs) and one closed-ring resonator, with one SRR free to rotate about the common axis of the structure in response to torques induced by the microwave pump. We observe EIT-like narrow-band resonant transmission in the carefully optimized device, which we characterize in a microwave waveguide, and verify that the resonance is due to the hybridized mode of all three resonators. We demonstrate nonlinear spectral narrowing and an increase of the group delay upon increasing the pump power and show the significant role of the intrinsic rotation of the freely rotatable SRR in this process.
Reconfigurable Acoustic Metagrating for High-Efficiency Anomalous Reflection
Publisher: American Physical Society (APS)
Date: 29-06-2020
Hybrid nanoantennas for directional emission enhancement
Publisher: AIP Publishing
Date: 12-2014
DOI: 10.1063/1.4903219
Abstract: Plasmonic and dielectric nanoparticles offer complementary strengths regarding their use as optical antenna elements. While plasmonic nanoparticles are well-known to provide strong decay rate enhancement for localized emitters, all-dielectric nanoparticles can enable high directivity combined with low losses. Here, we suggest a hybrid metal-dielectric nanoantenna consisting of a gold nanorod and a silicon nanodisk, which combines all these advantages. Our numerical analysis reveals a giant enhancement of directional emission together with simultaneously high radiation efficiency (exceeding 70%). The suggested hybrid nanoantenna has a subwavelength footprint, and all parameters and materials are chosen to be compatible with fabrication by two-step electron-beam lithography.
Detecting and segmenting overlapping red blood cells in microscopic images of thin blood smears
Publisher: SPIE
Date: 06-03-2018
DOI: 10.1117/12.2293762
Malaria Screener: a smartphone application for automated malaria screening
Publisher: Springer Science and Business Media LLC
Date: 11-11-2020
DOI: 10.1186/S12879-020-05453-1
Abstract: Light microscopy is often used for malaria diagnosis in the field. However, it is time-consuming and quality of the results depends heavily on the skill of microscopists. Automating malaria light microscopy is a promising solution, but it still remains a challenge and an active area of research. Current tools are often expensive and involve sophisticated hardware components, which makes it hard to deploy them in resource-limited areas. We designed an Android mobile application called Malaria Screener, which makes smartphones an affordable yet effective solution for automated malaria light microscopy. The mobile app utilizes high-resolution cameras and computing power of modern smartphones to screen both thin and thick blood smear images for P. falciparum parasites. Malaria Screener combines image acquisition, smear image analysis, and result visualization in its slide screening process, and is equipped with a database to provide easy access to the acquired data. Malaria Screener makes the screening process faster, more consistent, and less dependent on human expertise. The app is modular, allowing other research groups to integrate their methods and models for image processing and machine learning, while acquiring and analyzing their data.
Experimental manipulations of the biomass of introduced carp (Cyprinus carpio) in billabongs. I. Impacts on water-column properties
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/MF97031
Abstract: Two billabongs on the floodplain of the Murrumbidgee River, Australia, were partitioned in half with impermeable plastic barriers for four months from summer to winter 1995. The densities of carp were manipulated to establish high- and low-carp biomass treatments in each billabong. Final standing stocks of carp in the high- and low-carp treatments of each billabong were 1181 and 101 kg ha-1 , and 669 and 348 kg ha-1 , respectively. Turbidity, phytoplankton biomass and total and dissolved phosphorus concentrations were similar in both ends of each billabong before the establishment of the plastic barriers. Throughout the experimental period, turbidity and phytoplankton biomass were significantly higher in the high-carp treatment in both billabongs. However, the two billabongs had different temporal patterns for both turbidity and phytoplankton biomass. Concentrations of total phosphorus were usually greater in the high-carp end of each billabong but there was no consistent pattern for dissolved phosphorus. Carp had a significant impact on turbidity and intensity of algal bloom but this varied with carp biomass and billabong sediment type, and factors other than carp usually contributed to most of the variation in measured water quality.
Optimum sensitive area of surface acoustic wave resonator chemical and bio-sensors
Publisher: IEEE
Date: 2005
Resonant dynamics of arbitrarily shaped meta-atoms
Publisher: American Physical Society (APS)
Date: 06-08-2014
Dynamic optical activity and self-oscillation in torsional metamaterials
Publisher: IEEE
Date: 09-2013
Broadband chiral metamaterials with large optical activity
Publisher: American Physical Society (APS)
Date: 10-03-2014
Development of an Equivalent Circuit Model for the Design of Array of Electrically Small Antennas
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Polarization-Induced Chirality in Metamaterials via Optomechanical Interaction
Publisher: Wiley
Date: 27-12-2016
Giant nonlinear optical activity in chiral metamaterials
Publisher: IEEE
Date: 12-2010
Tunable focusing by a flexible metasurface
Publisher: Elsevier BV
Date: 09-2017
Twists and shifts make nonlinear metamaterials
Publisher: IEEE
Date: 05-2013
Structural tunability in metamaterials
Publisher: AIP Publishing
Date: 24-08-2009
DOI: 10.1063/1.3211920
Abstract: We propose an efficient approach for tuning the transmission characteristics of metamaterials through a continuous adjustment of the lattice structure and confirm it experimentally in the microwave range. The concept is rather general and applicable to various metamaterials as long as the effective medium description is valid. The demonstrated continuous tuning of a metamaterial response is highly desirable for a number of emerging applications of metamaterials, including sensors, filters, and switches, realizable in a wide frequency range.
Polarization properties of optical metasurfaces of different symmetries
Publisher: American Physical Society (APS)
Date: 05-05-2015
Purcell effect in hyperbolic metamaterial resonators
Publisher: American Physical Society (APS)
Date: 16-11-2015
Printed tapered leaky-wave antennas for W-band frequencies
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2021
Flexible Helices for Nonlinear Metamaterials
Publisher: Wiley
Date: 21-05-2013
Abstract: The successful fabrication and experimental verification of a novel metamaterial based on flexible metallic helices is reported. The helices undergo compression under the influence of incident radiation, demonstrating a nonlinear chiral electromagnetic response, associated with the power-dependent change in the helix pitch. This design is promising for application to power-dependent polarization rotation of propagating waves.
Interaction of twisted split ring resonators
Publisher: IEEE
Date: 05-2011
Symmetry properties of metamaterials at oblique incidence
Publisher: IEEE
Date: 09-2013
Dispersionless optical activity in metamaterials
Publisher: AIP Publishing
Date: 20-05-2013
DOI: 10.1063/1.4807438
Abstract: We introduce a chiral metamaterial with strong, non-resonant optical activity and very low polarization ellipticity. We achieve this by combining a meta-atom and its complementary structure into a meta-molecule, resulting in the coupling of magnetic and electric dipole responses. In contrast to either a pair of crosses or complementary crosses, this structure has low dispersion in the optical activity at the transmission resonance. We also study the excitation mechanism in this structure and optimize the optical activity through changing the twist angle.
A finite element approach for 3-dimensional simulation of layered acoustic wave transducers
Publisher: IEEE
Date: 2002
Huygens’ Metadevices for Parametric Waves
Publisher: American Physical Society (APS)
Date: 20-09-2018
Electrically tunable terahertz metamaterials with embedded large-area transparent thin-film transistor arrays
Publisher: Springer Science and Business Media LLC
Date: 22-03-2016
DOI: 10.1038/SREP23486
Abstract: Engineering metamaterials with tunable resonances are of great importance for improving the functionality and flexibility of terahertz (THz) systems. An ongoing challenge in THz science and technology is to create large-area active metamaterials as building blocks to enable efficient and precise control of THz signals. Here, an active metamaterial device based on enhancement-mode transparent amorphous oxide thin-film transistor arrays for THz modulation is demonstrated. Analytical modelling based on full-wave techniques and multipole theory exhibits excellent consistent with the experimental observations and reveals that the intrinsic resonance mode at 0.75 THz is dominated by an electric response. The resonant behavior can be effectively tuned by controlling the channel conductivity through an external bias. Such metal/oxide thin-film transistor based controllable metamaterials are energy saving, low cost, large area and ready for mass-production, which are expected to be widely used in future THz imaging, sensing, communications and other applications.
Strong terahertz absorption in all-dielectric Huygens’ metasurfaces
Publisher: IOP Publishing
Date: 19-09-2016
DOI: 10.1088/0957-4484/27/42/424003
Abstract: We propose an all dielectric metamaterial that acts as a perfect terahertz absorber without a ground plane. The unit cell consists of a dielectric cylinder embedded in a low index material. In order to achieve near-perfect terahertz absorption (99.5%) we employ impedance matching of the electric and magnetic resonances within the cylinders of the Huygens' metasurface. The impedance matching is controlled by changing the aspect ratio between the height and diameter of the cylinder. We show that the absorption resonance can be tuned to particular frequencies from 0.3 to 1.9 THz via changing the geometry of the structure while keeping a nearly constant aspect ratio of the cylinders.
Spatial dispersion of multilayer fishnet metamaterials
Publisher: The Optical Society
Date: 20-06-2012
DOI: 10.1364/OE.20.015100
Tuning methods for metamaterials
Publisher: SPIE
Date: 30-04-2010
DOI: 10.1117/12.855119
Metamaterials with conformational nonlinearity
Publisher: Springer Science and Business Media LLC
Date: 02-11-2011
DOI: 10.1038/SREP00138
Tuning linear and nonlinear properties of broadside-coupled resonators
Publisher: IEEE
Date: 08-2011
Polyaniline Nanofiber Based Surface Acoustic Wave Gas Sensors—Effect of Nanofiber Diameter on $\hbox{H}_{2}$ Response
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2007
Switchable graded index microwave metamaterial lens design using pneumatic actuation
Publisher: IEEE
Date: 12-2012
Post-processing approach for tuning multi-layered metamaterials
Publisher: AIP Publishing
Date: 13-10-2014
DOI: 10.1063/1.4897949
Abstract: We propose a post-processing approach to efficiently tune the resonance frequency in double-layered terahertz metamaterials separated by a bonding agent. By heating the bonding agent, it is possible to move one metamaterial layer laterally with respect to the other. This changes the coupling between adjacent layers, thereby shifting the resonance frequency. The resonance frequency of the stacked layers continuously shifts as a function of the lateral displacement, reaching a maximum shift of 92 GHz (31% of the center frequency). We discuss the effects of vertical separation on the tunability of the two-layered structure. The post-processing approach is rather general and can be applied to different paired metamaterials in various wavelength ranges, paving the way to efficiently assemble and fine tune metamaterial sensors and filters.
Strong Broadband Terahertz Optical Activity through Control of the Blaschke Phase with Chiral Metasurfaces
Publisher: American Physical Society (APS)
Date: 21-07-2017
General Framework of Bound States in the Continuum in an Open Acoustic Resonator
Publisher: American Physical Society (APS)
Date: 08-11-2022
Sound Trapping in an Open Resonator
Publisher: Research Square Platform LLC
Date: 11-03-2021
DOI: 10.21203/RS.3.RS-284982/V1
Abstract: The ability of extreme sound energy confinement with high-quality factor (Q-factor) resonance is of vital importance for acoustic devices requiring high intensity and hypersensitivity in biological ultrasonics, enhanced collimated sound emission (i.e. sound laser) and high-resolution sensing. However, structures reported so far demonstrated a limited quality factor (Q-factor) of acoustic resonances, up to several tens in an open resonator. The emergence of bound states in the continuum (BIC) makes it possible to realize high-Q factor acoustic modes. Here, we report the theoretical design and experimental demonstration of acoustic BICs supported by a single open resonator. We predicted that such an open acoustic resonator could simultaneously support three types of BICs, including symmetry protected BIC, Friedrich-Wintgen BIC induced by mode interference, as well as a new kind of BIC: mirror-symmetry induced BIC. We also experimentally demonstrated the existence of all three types of BIC with Q-factor up to one order of magnitude greater than the highest Q-factor reported in an open resonator.
Experimental observation of slow light tunneling in coupled periodic waveguides
Publisher: IEEE
Date: 07-2008
Huygens Metasurface Lens for W-Band Switched Beam Antenna Applications
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Dual‐Region Resonant Meander Metamaterial
Publisher: Wiley
Date: 19-02-2020
Tunable fishnet metamaterials infiltrated by liquid crystals
Publisher: AIP Publishing
Date: 10-05-2010
DOI: 10.1063/1.3427429
Abstract: We analyze numerically the optical response and effective macroscopic parameters of fishnet metamaterials infiltrated with a nematic liquid crystal. We show that even a small amount of liquid crystal can provide tuning of the structures due to reorientation of the liquid crystal director. This enables switchable optical metamaterials, where the refractive index can be switched from positive to negative by an external field. This tuning is primarily determined by the shift in the cut-off wavelength of the holes, with only a small influence due to the change in plasmon dispersion.
Metahouse: Noise‐Insulating Chamber Based on Periodic Structures
Publisher: Wiley
Date: 09-11-2022
Abstract: Noise pollution remains a challenging problem requiring the development of novel systems for noise insulation. Extensive work in the field of acoustic metamaterials has led to various ventilated structures which, however, are usually demonstrated for rather narrow regions of the audible spectrum. In this work, the idea of metamaterial‐based systems is further extended, developing the concept of a metahouse chamber representing a ventilated structure for multiple band noise insulation. Broad stop‐bands originate from strong coupling between pairs of Helmholtz resonators constituting the structure. The averaged transmission −18.6 dB are demonstrated numerically and experimentally within the spectral range from 1500 to 16 500 Hz. The sparseness of the structure together with the possibility to use optically transparent materials suggest that the chamber may be also characterized by partial optical transparency depending on the mutual position of structural elements. The obtained results are promising for development of novel noise‐insulating structures advancing urban science.
Acoustic metamaterial capsule for reduction of stage machinery noise
Publisher: Acoustical Society of America (ASA)
Date: 03-2020
DOI: 10.1121/10.0000857
Abstract: Noise mitigation of stage machinery can be quite demanding and requires innovative solutions. In this work, an acoustic metamaterial capsule is proposed to reduce the noise emission of several stage machinery drive trains, while still allowing the ventilation required for cooling. The metamaterial capsule consists of c-shape meta-atoms, which have a simple structure that facilitates manufacturing. Two different metamaterial capsules are designed, simulated, manufactured, and experimentally validated that utilize an ultra-sparse and air-permeable reflective meta-grating. Both designs demonstrate transmission loss peaks that effectively suppress gear mesh noise or other narrow band noise sources. The ventilation by natural convection was numerically verified, and was shown to give adequate cooling, whereas a conventional sound capsule would lead to overheating. The noise spectra of three common stage machinery drive trains are numerically modelled, enabling one to design meta-gratings and determine their noise suppression performance. The results fulfill the stringent stage machinery noise limits, highlighting the benefit of using metamaterial capsules of simple c-shape structure.
Asymmetric parametric amplification in nonlinear left-handed transmission lines
Publisher: AIP Publishing
Date: 23-02-2009
DOI: 10.1063/1.3089842
Abstract: We study parametric lification in nonlinear left-handed transmission lines, which serve as model systems for nonlinear negative-index metamaterials. We experimentally demonstrate the lification of a weak signal in the three following regimes: with the signal in the left-handed band, with the signal in the stop band, and with the signal at a defect frequency. In particular, we demonstrate the lification of the incident wave by up to 15 dB in the left-handed regime.
Observation of slow-light dynamics in coupled periodic waveguides
Publisher: IEEE
Date: 06-2009
H2 and NO2 gas sensors with ZnO nanobelt layer on 36° LiTaO3 and 64° LiNbO3 SAW transducers
Publisher: IEEE
Date: 2005
Self-oscillations in nonlinear torsional metamaterials
Publisher: IOP Publishing
Date: 18-07-2013
Acoustic meta-atom with experimentally verified maximum Willis coupling
Publisher: Springer Science and Business Media LLC
Date: 17-07-2019
DOI: 10.1038/S41467-019-10915-5
Abstract: Acoustic metamaterials are structures with exotic acoustic properties, with promising applications in acoustic beam steering, focusing, impedance matching, absorption and isolation. Recent work has shown that the efficiency of many acoustic metamaterials can be enhanced by controlling an additional parameter known as Willis coupling, which is analogous to bianisotropy in electromagnetic metamaterials. The magnitude of Willis coupling in a passive acoustic meta-atom has been shown theoretically to have an upper limit, however the feasibility of reaching this limit has not been experimentally investigated. Here we introduce a meta-atom with Willis coupling which closely approaches this theoretical limit, that is much simpler and less prone to thermo-viscous losses than previously reported structures. We perform two-dimensional experiments to measure the strong Willis coupling, supported by numerical calculations. Our meta-atom geometry is readily modeled analytically, enabling the strength of Willis coupling and its peak frequency to be easily controlled.
Magnetoelastic metamaterials
Publisher: Springer Science and Business Media LLC
Date: 13-11-2012
DOI: 10.1038/NMAT3168
Abstract: The study of advanced artificial electromagnetic materials, known as metamaterials, provides a link from material science to theoretical and applied electrodynamics, as well as to electrical engineering. Being initially intended mainly to achieve negative refraction, the concept of metamaterials quickly covered a much broader range of applications, from microwaves to optics and even acoustics. In particular, nonlinear metamaterials established a new research direction giving rise to fruitful ideas for tunable and active artificial materials. Here we introduce the concept of magnetoelastic metamaterials, where a new type of nonlinear response emerges from mutual interaction. This is achieved by providing a mechanical degree of freedom so that the electromagnetic interaction in the metamaterial lattice is coupled to elastic interaction. This enables the electromagnetically induced forces to change the metamaterial structure, dynamically tuning its effective properties. This concept leads to a new generation of metamaterials, and can be compared to such fundamental concepts of modern physics as optomechanics of photonic structures or magnetoelasticity in magnetic materials.
Finite-element analysis for simulation of layered SAW devices with XY LiNbO 3 substrate
Publisher: SPIE
Date: 11-2002
DOI: 10.1117/12.469080
Detecting and Segmenting White Blood Cells in Microscopy Images of Thin Blood Smears
Publisher: IEEE
Date: 10-2017
Electromagnetic wave analogue of an electronic diode
Publisher: IOP Publishing
Date: 18-03-2011
Temperature control of terahertz metamaterials with liquid crystals
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2013
Deeply Subwavelength Metasurface Resonators for Terahertz Wavefront Manipulation
Publisher: Wiley
Date: 13-08-2019
Hybrid metal-dielectric nanoantennas for directional emission enhancement
Publisher: OSA
Date: 2015
Nonlinear electric metamaterials
Publisher: AIP Publishing
Date: 24-08-2009
DOI: 10.1063/1.3212726
Abstract: We propose and design a new type of nonlinear metamaterials exhibiting a resonant electric response at microwave frequencies. By introducing a varactor diode as a nonlinear element within each resonator, we are able to shift the frequency of the electric mode stop band by changing the incident power without affecting the magnetic response. These elements could be combined with the previously developed nonlinear magnetic metamaterials in order to create negative index media with a control over both electric and magnetic nonlinearities.
Spatial sensitivity distribution of surface acoustic wave resonator sensors
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2007
Spontaneous chiral symmetry breaking in metamaterials
Publisher: Springer Science and Business Media LLC
Date: 18-07-2014
DOI: 10.1038/NCOMMS5441
Abstract: Spontaneous chiral symmetry breaking underpins a variety of areas such as subatomic physics and biochemistry, and leads to an impressive range of fundamental phenomena. Here we show that this prominent effect is now available in artificial electromagnetic systems, enabled by the advent of magnetoelastic metamaterials where a mechanical degree of freedom leads to a rich variety of strong nonlinear effects such as bistability and self-oscillations. We report spontaneous symmetry breaking in torsional chiral magnetoelastic structures where two or more meta-molecules with opposite handedness are electromagnetically coupled, modifying the system stability. Importantly, we show that chiral symmetry breaking can be found in the stationary response of the system, and the effect is successfully demonstrated in a microwave pump-probe experiment. Such symmetry breaking can lead to a giant nonlinear polarization change, energy localization and mode splitting, which provides a new possibility for creating an artificial phase transition in metamaterials, analogous to that in ferrimagnetic domains.
The sub-wavelength imaging performance of disordered wire media
Publisher: Elsevier BV
Date: 05-2008
Second harmonic generation in the zero-index regime
Publisher: IEEE
Date: 08-2011
Novel nonlinear chiral metamaterials
Publisher: IEEE
Date: 07-2013
Liquid crystal based nonlinear fishnet metamaterials
Publisher: AIP Publishing
Date: 19-03-2012
DOI: 10.1063/1.3695165
Abstract: We study experimentally the nonlinear properties of fishnet metamaterials infiltrated with nematic liquid crystals and find that moderate laser powers result in significant changes of the optical transmission of the composite structures. We also show that the nonlinear response of our structure can be further tuned with a bias electric field, enabling the realization of electrically tunable nonlinear metamaterials.
Mechanically tunable bi-layer terahertz metamaterials
Publisher: OSA
Date: 2015
Nonlinear control of tunneling through an epsilon-near-zero channel
Publisher: American Physical Society (APS)
Date: 29-06-2009
Layered SAW nitrogen dioxide sensor with WO3 selective layer
Publisher: SPIE
Date: 25-04-2003
DOI: 10.1117/12.512086
Magnetoelastic metamaterials
Publisher: IEEE
Date: 05-2011
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