ORCID Profile
0000-0002-2419-4431
Current Organisation
Monash University
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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.
Nanotechnology | Optical fibre communication systems and technologies | Photonics and Electro-Optical Engineering (excl. Communications) | Interdisciplinary Engineering not elsewhere classified | Optical And Photonic Systems | Numerical and Computational Mathematics not elsewhere classified | Artificial Intelligence and Image Processing | Electrical and Electronic Engineering | Nanophotonics | Developmental Psychology and Ageing | Nanomaterials | Communications Technologies | Communications engineering | Electrical and Electronic Engineering not elsewhere classified | Other Electronic Engineering | Psychology | Interdisciplinary Engineering Not Elsewhere Classified | Central Nervous System | Photonic and electro-optical devices sensors and systems (excl. communications) | Engineering electromagnetics | Medical Biotechnology Diagnostics (incl. Biosensors) | Electronics sensors and digital hardware | Wireless communication systems and technologies (incl. microwave and millimetrewave) | Other Information, Computing And Communication Sciences | Optics And Opto-Electronic Physics | Nanobiotechnology | Pattern Recognition | Nanofabrication, Growth and Self Assembly
Expanding Knowledge in Technology | Expanding Knowledge in Engineering | Neurodegenerative Disorders Related to Ageing | Network transmission equipment | Expanding Knowledge in the Medical and Health Sciences | Modules—other processes | Other | Computer software and services not elsewhere classified | Civil | Diagnostic Methods | Expanding Knowledge in the Physical Sciences |
Publisher: IOP Publishing
Date: 18-10-2012
DOI: 10.1088/0957-4484/23/44/444006
Abstract: We study guided optical modes of a planar plasmonic waveguide filled with a generic anisotropic medium. In particular, we show that both surface and oscillatory modes exist for such waveguides and find their numbers for two specific forms of the anisotropy tensor. We also show that lossless waveguides, characterized by a diagonal permittivity tensor, support simultaneously both the forward and backward propagating modes (surface or oscillatory type) with antisymmetric field patterns. Another family of guided oscillatory modes may be supported by the waveguide if its anisotropy is created by an external magnetic field. These new modes are asymmetric in nature, exhibit extremely low effective refractive indices and may propagate over macroscopic distances without significant attenuation, while remaining strongly confined to the waveguide.
Publisher: Institution of Engineering and Technology (IET)
Date: 2007
DOI: 10.1049/EL:20073712
Publisher: IOP Publishing
Date: 11-01-2018
Publisher: IOP Publishing
Date: 08-09-2021
Publisher: American Physical Society (APS)
Date: 20-12-2022
Publisher: OSA
Date: 2010
Publisher: IEEE
Date: 08-2011
Publisher: The Optical Society
Date: 06-11-2012
DOI: 10.1364/OE.20.026275
Publisher: Optica Publishing Group
Date: 07-12-2009
DOI: 10.1364/OE.17.023423
Publisher: AIP Publishing
Date: 05-06-2015
DOI: 10.1063/1.4922124
Abstract: We have modeled and numerically simulated the performance of a dielectric-loaded graphene surface-plasmon-polariton (DL-GSPP) waveguide as a biochemical sensing device. In our device, the conventionally used gold layer is replaced with a graphene microribbon for the detection of biochemical molecules. The graphene layer is incorporated to minimize ohmic losses and to enhance the adsorption of biomolecules so that the sensor sensitivity is increased significantly. The sensor performance is quantified through numerical simulations carried out by varying device parameters such as waveguide length, effective mode index, dimension of the dielectric ridge, and the length and the number of graphene layers. One of the prominent features of our DL-GSPP waveguide sensor is that its length is in the millimeter range, an essential requirement for realistic plasmonic waveguide sensors. The average sensitivity of DL-GSPP structure is found to be in the range of 3–6 μRIU (refractive index units), which is comparable to the values obtained using surface-plasmon resonance (1–10 μRIU) and long-range waveguide sensors (0.1–5 μRIU).
Publisher: American Physical Society (APS)
Date: 06-07-2020
Publisher: IEEE
Date: 12-2014
Publisher: The Optical Society
Date: 23-01-2012
DOI: 10.1364/OE.20.002858
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TC04051B
Abstract: Under aggregation-free conditions, linear relationships between longitudinal plasmonic peak intensity and temperature have been revealed for poly( N -isopropylacrylamide)-capped gold nanorods and nanobipyramids.
Publisher: AIP Publishing
Date: 21-08-2017
DOI: 10.1063/1.4998459
Abstract: The ability to control light-matter interactions in quantum objects opens up many avenues for new applications. We look at this issue within a fully quantized framework using a fundamental theory to describe mirror-assisted resonance energy transfer (RET) in nanostructures. The process of RET communicates electronic excitation between suitably disposed donor and acceptor particles in close proximity, activated by the initial excitation of the donor. Here, we demonstrate that the energy transfer rate can be significantly controlled by careful positioning of the RET emitters near a mirror. The results deliver equations that elicit new insights into the associated modification of virtual photon behavior, based on the quantum nature of light. In particular, our results indicate that energy transfer efficiency in nanostructures can be explicitly expedited or suppressed by a suitably positioned neighboring mirror, depending on the relative spacing and the dimensionality of the nanostructure. Interestingly, the resonance energy transfer between emitters is observed to “switch off” abruptly under suitable conditions of the RET system. This allows one to quantitatively control RET systems in a new way.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2006
Publisher: American Chemical Society (ACS)
Date: 26-02-2014
DOI: 10.1021/NN406015D
Abstract: Spaser is a nanoscale source of surface plasmons comprising a plasmonic resonator and gain medium to replenish energy losses. Here we propose a carbon-based spaser design in which a graphene nanoflake (GNF) resonator is coupled to a carbon nanotube (CNT) gain element. We theoretically demonstrate that the optically excited CNT can nonradiatively transfer its energy to the localized plasmon modes of the GNF because of the near-field interaction between the modes and the CNT excitons. By calculating the localized fields of the plasmon modes and the matrix elements of the plasmon-exciton interaction, we find the optimal geometric and material parameters of the spaser that yield the highest plasmon generation rate. The results obtained may prove useful in designing robust and ultracompact coherent sources of surface plasmons for plasmonic nanocircuits.
Publisher: IEEE
Date: 12-2014
Publisher: IOP Publishing
Date: 18-02-2021
Abstract: Electronic excitation energy transfer is a ubiquitous process that has generated prime research interest since its discovery. Recently developed variational polaron transformation-based second-order master equation is capable of interpolating between Förster and Redfield limits with exceptional accuracy. Forms of spectral density functions studied so far through the variational approach provide theoretical support for various experiments. Recently introduced ohmic like spectral density function that can account for logarithmic perturbations provides generality and exposition to a unique and practical set of environments. In this paper, we exploit the energy transfer dynamics of a two-level system attached to an ohmic like spectral density function with logarithmic perturbations using a variational polaron transformed master equation. Our results demonstrate that even for a relatively large bath coupling strength, quantum coherence effects can be increased by introducing logarithmic perturbations of the order of one and two in super-ohmic environments. Moreover, for particular values of the ohmicity parameter, the effect of logarithmic perturbations is observed to be insignificant for the overall dynamics. In regard to ohmic environments, as logarithmic perturbations increase, d ing characteristics of the coherent transient dynamics also increase in general. It is also shown that, having logarithmic perturbations of the order of one in an ohmic environment can result in a less efficient energy transfer for relatively larger system bath coupling strengths.
Publisher: CRC Press
Date: 10-10-2013
DOI: 10.1201/B15615
Publisher: American Chemical Society (ACS)
Date: 27-09-2016
Publisher: IEEE
Date: 12-2009
Publisher: IEEE
Date: 12-2010
Publisher: Institute of Electronics, Information and Communications Engineers (IEICE)
Date: 05-2005
Publisher: Wiley
Date: 14-05-2018
Abstract: The electronic, optical, thermal, and magnetic properties of an extrinsic bulk semiconductor can be finely tuned by adjusting its dopant concentration. Here, it is demonstrated that such a doping concept can be extended to plasmonic nanomaterials. Using two-dimensional (2D) assemblies of Au@Ag and Au nanocubes (NCs) as a model system, detailed experimental and theoretical studies are carried out, which reveal collective semiconductor n -doping-like plasmonic properties. A threshold doping concentration of Au@Ag NCs is observed, below which p-doping dominates and above which n-doping prevails. Furthermore, Au@Ag NC dopants can be converted into corresponding Au seed "voids" dopants by selectively removing Ag without changing the overall structural integrity. The results show that the plasmonic doping concept may serve as a general design principle guiding synthesis and assembly of plasmonic metamaterials for programmable optoelectronic devices.
Publisher: IOP Publishing
Date: 21-08-2023
Abstract: This study introduces a novel theoretical framework for detecting and decoding wireless communication signals in the nanoscale range operating at terahertz (THz) frequencies. Initially, we investigate the Floquet states in a dressed 2D semiconductor quantum well and derive an analytical expression to determine its longitudinal conductivity. The results indicate that the longitudinal conductivity of a dressed 2D semiconductor can be tailored to specific requirements by manipulating the frequency of the external dressing field. Furthermore, carefully selecting the intensity and polarization type of the external dressing field enables fine-tuning and optimization of the conductivity. To evaluate the effectiveness of each dressing field configuration, we present a figure of Merit (FoM) assessment that determines the maximum possible change in conductivity within the considered frequency range. The proposed theory introduces a mechanism capable of identifying frequency-modulated communication signals in the THz range and performing frequency demodulation. We comprehensively analyze of the demodulator’s transfer function in the receiver. Consequently, we establish that the transfer function exhibits linear behavior over a specific frequency range, rendering it suitable for frequency demodulation. Finally, we provide a numerical illustration of a frequency demodulation scenario. The breakthrough uncovered in this study opens up possibilities for the development of high-efficiency, lightweight, and cutting-edge chip-scale wireless communication devices, circuits, and components.
Publisher: IEEE
Date: 2007
DOI: 10.1109/FBIT.2007.22
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NH00393J
Abstract: A plasmonic skin has been demonstrated with an elastomer-supported, highly ordered, and closely packed plasmonic nanocrystal array (plasmene).
Publisher: American Physical Society (APS)
Date: 28-03-2011
Publisher: American Chemical Society (ACS)
Date: 08-01-2016
Abstract: Anisotropic plasmonic nanoparticles have been successfully used as constituent elements for growing ordered nanoparticle arrays. However, orientational control over their spatial ordering remains challenging. Here, we report on a self-assembled two-dimensional (2D) nanoparticle liquid crystalline superstructure (NLCS) from bipyramid gold nanoparticles (BNPs), which showed four distinct orientational packing orders, corresponding to horizontal alignment (H-NLCS), circular arrangement (C-NLCS), slanted alignment (S-NLCS), and vertical alignment (V-NLCS) of constituent particle building elements. These packing orders are characteristic of the unique shape of BNPs because all four packing modes were observed for particles with various sizes. Nevertheless, only H-NLCS and V-NLCS packing orders were observed for the free-standing ordered array nanosheets formed from a drying-mediated self-assembly at the air/water interface of a sessile droplet. This is due to strong surface tension and the absence of particle-substrate interaction. In addition, we found the collective plasmonic coupling properties mainly depend on the packing type, and characteristic coupling peak locations depend on particle sizes. Interestingly, surface-enhanced Raman scattering (SERS) enhancements were heavily dependent on the orientational packing ordering. In particular, V-NLCS showed the highest Raman enhancement factor, which was about 77-fold greater than the H-NLCS and about 19-fold greater than C-NLCS. The results presented here reveal the nature and significance of orientational ordering in controlling plasmonic coupling and SERS enhancements of ordered plasmonic nanoparticle arrays.
Publisher: Springer Science and Business Media LLC
Date: 27-02-2014
Publisher: The Optical Society
Date: 22-12-2010
DOI: 10.1364/OE.19.000206
Publisher: Springer Science and Business Media LLC
Date: 21-04-2017
DOI: 10.1038/S41598-017-00785-6
Abstract: Being an enabling technology for applications such as ultrasensitive biosensing and surface enhanced spectroscopy, enormous research interests have been focused on further boosting the local field enhancement at Fano resonance. Here, we demonstrate a plasmonic Fano resonance resulting from the interference between a narrow magnetic dipole mode and a broad electric dipole mode in a split-ring resonator (SRR) coupled to a nanoarc structure. Strikingly, when subjected to an azimuthally polarized beam (APB) excitation, the intensity enhancement becomes more than 60 times larger than that for a linearly polarized beam (LPB). We attribute this intensity enhancement to the improved conversion efficiency between the excitation and magnetic dipole mode along with improved near-field coupling. The APB excited Fano structure is further used as a nanoruler and beam misalignment sensor, due to the high sensitivity of intensity enhancement and scattering spectra to structure irregularities and excitation beam misalignment. Interestingly, we find that, regardless of the presence of structural translations, the proposed structure still maintains over 60 times better intensity enhancement under APB excitation compared to LPB excitation. Moreover, even if the APB excitation is somewhat misaligned, our Fano structure still manages to give a larger intensity enhancement than its counterpart excited by LPB.
Publisher: The Optical Society
Date: 28-09-2011
DOI: 10.1364/OE.19.019973
Publisher: Optica Publishing Group
Date: 2007
DOI: 10.1364/OE.15.011570
Abstract: We demonstrate a novel scheme to generate multiple wavelengths in the L-band using a Brillouin-Erbium fiber laser. Our scheme utilizes extraneous lified spontaneous emission in the C-band as a secondary pump source for a passive Erbium-doped fiber gain section along the cavity. The Brillouin gain medium is generated by the 6.7 km long of single mode fiber (SMF-28). We experimentally demonstrate that a total of 28 stable output channels with a spacing of 0.089 nm can be generated using our new scheme. This represents a 33% increase in the number of wavelengths generated compared with conventional schemes.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CP03043B
Abstract: Hot electron injection from a metallic nanotube under optical illumination into a semiconductor layer in contact with its inner boundary.
Publisher: The Optical Society
Date: 19-07-2017
DOI: 10.1364/OE.25.018265
Publisher: The Optical Society
Date: 23-09-2010
DOI: 10.1364/OE.18.021427
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-1999
DOI: 10.1109/68.803051
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CP04544A
Abstract: Machine learning techniques can predict the solution temperature of thermosensitive polymer-capped nanoparticle solutions to within 1 °C of accuracy.
Publisher: American Chemical Society (ACS)
Date: 28-12-2011
DOI: 10.1021/NN204498J
Abstract: The self-assembly of monodisperse inorganic nanoparticles into highly ordered arrays (superlattices) represents an exciting route to materials and devices with new functions. It allows programming their properties by varying the size, shape, and composition of the nanoparticles, as well as the packing order of the assemblies. While substantial progress has been achieved in the fabrication of superlattice materials made of nanospheres, limited advances have been made in growing similar materials with anisotropic building blocks, which is particularly true for free-standing two-dimensional superlattices. In this paper, we report the controlled growth of free-standing, large-area, monolayered gold-nanorod superlattice sheets by polymer ligands in an entropy-driven interfacial self-assembly process. Furthermore, we experimentally characterize the plasmonic properties of horizontally aligned sheets (H-sheets) and vertically aligned sheets (V-sheets) and show that observed features can be well described using a theoretical model based on the discrete-dipole approximation. Our polymer-ligand-based strategy may be extended to other anisotropic plasmonic building blocks, offering a robust and inexpensive avenue to plasmonic nanosheets for various applications in nanophotonic devices and sensors.
Publisher: American Physical Society (APS)
Date: 06-2020
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: American Chemical Society (ACS)
Date: 02-11-2017
Abstract: The inception of the plasmonic laser or spaser (surface plasmon lification by stimulated emission of radiation) concept in 2003 provides a solution for overcoming the diffraction limit of electromagnetic waves in miniaturization of traditional lasers into the nanoscale. From then on, many spaser designs have been proposed. However, all existing designs use closed resonators. In this work, we use cavity quantum electrodynamics analysis to theoretically demonstrate that it is possible to design an electric spaser with an open resonator or a closed resonator with much weak feedback in the extreme quantum limit in an all-carbon platform. A carbon nanotube quantum dot plays the role of a gain element, and Coulomb blockade is observed. Graphene nanoribbons are used as the resonator, and surface plasmon polariton field distribution with quantum electrodynamics features can be observed. From an engineering perspective, our work makes preparations for integrating spasers into nanocircuits and/or photodynamic therapy applications.
Publisher: The Optical Society
Date: 25-07-2019
DOI: 10.1364/OL.44.003813
Publisher: Elsevier
Date: 2010
Publisher: IEEE
Date: 11-2007
Publisher: Wiley
Date: 09-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2009
Publisher: Springer Berlin Heidelberg
Date: 2010
Publisher: Optica Publishing Group
Date: 24-12-2009
DOI: 10.1364/OL.35.000055
Publisher: Elsevier BV
Date: 2013
Publisher: AIP Publishing
Date: 24-02-2015
DOI: 10.1063/1.4907536
Abstract: Cubic dielectric nanoparticles are promising candidates for futuristic low-loss, ultra-compact, nanophotonic applications owing to their larger optical coefficients, greater packing density, and relative ease of fabrication as compared to spherical nanoparticles besides possessing negligible heating at nanoscale in contrast to their metallic counterparts. Here, we present the first theoretical demonstration of azimuthally symmetric, ultra-directional Kerker's-type scattering of simple dielectric nanocubes in visible and near-infrared regions via simultaneous excitation and interference of optically induced electric- and magnetic-resonances up to quadrupolar modes. Unidirectional forward-scattering by in idual nanocubes is observed at the first generalized-Kerker's condition for backward-scattering suppression, having equal electric- and magnetic-dipolar responses. Both directionality and magnitude of these unidirectional-scattering patterns get enhanced where matching electric- and magnetic-quadrupolar responses spectrally overlap. While preserving azimuthal-symmetry and backscattering suppression, a nanocube homodimer provides further directionality improvement for increasing interparticle gap, but with reduced main-lobe magnitude due to emergence of side-scattering lobes from diffraction-grating effect. We thoroughly investigate the influence of interparticle gap on scattering patterns and propose optimal range of gap for minimizing side-scattering lobes. Besides suppressing undesired side-lobes, significant enhancement in scattering magnitude and directionality is attained with increasing number of nanocubes forming a linear chain. Optimal directionality, i.e., the narrowest main-scattering lobe, is found at the wavelength of interfering quadrupolar resonances whereas the largest main-lobe magnitude is observed at the wavelength satisfying the first Kerker's condition. These unique optical properties of dielectric nanocubes thus can revolutionize their applications at visible and near-infrared regions in the fields of nanoantennas, nanolasers, photovoltaics, and even in biomedicine.
Publisher: IEEE
Date: 2005
Publisher: Springer Science and Business Media LLC
Date: 18-02-2016
DOI: 10.1038/SREP21470
Abstract: We propose a nano-scale current-direction-switching device(CDSD) that operates based on the novel phenomenon of geometrical asymmetry between two hot-electron generating plasmonic nanostructures. The proposed device is easy to fabricate and economical to develop compared to most other existing designs. It also has the ability to function without external wiring in nano or molecular circuitry since it is powered and controlled optically. We consider a such CDSD made of two dissimilar nanorods separated by a thin but finite potential barrier and theoretically derive the frequency-dependent electron/current flow rate. Our analysis takes in to account the quantum dynamics of electrons inside the nanorods under a periodic optical perturbation that are confined by nanorod boundaries, modelled as finite cylindrical potential wells. The influence of design parameters, such as geometric difference between the two nanorods, their volumes and the barrier width on quality parameters such as frequency-sensitivity of the current flow direction, magnitude of the current flow, positive to negative current ratio and the energy conversion efficiency is discussed by considering a device made of Ag/TiO 2 /Ag. Theoretical insight and design guidelines presented here are useful for customizing our proposed CDSD for applications such as self-powered logic gates, power supplies and sensors.
Publisher: Springer Science and Business Media LLC
Date: 21-10-2020
DOI: 10.1038/S41597-020-00699-5
Abstract: Simultaneous [18 F]-fluorodeoxyglucose positron emission tomography and functional magnetic resonance imaging (FDG-PET/fMRI) provides the capability to image two sources of energetic dynamics in the brain – cerebral glucose uptake and the cerebrovascular haemodynamic response. Resting-state fMRI connectivity has been enormously useful for characterising interactions between distributed brain regions in humans. Metabolic connectivity has recently emerged as a complementary measure to investigate brain network dynamics. Functional PET (fPET) is a new approach for measuring FDG uptake with high temporal resolution and has recently shown promise for assessing the dynamics of neural metabolism. Simultaneous fMRI/fPET is a relatively new hybrid imaging modality, with only a few biomedical imaging research facilities able to acquire FDG PET and BOLD fMRI data simultaneously. We present data for n = 27 healthy young adults (18–20 yrs) who underwent a 95-min simultaneous fMRI/fPET scan while resting with their eyes open. This dataset provides significant re-use value to understand the neural dynamics of glucose metabolism and the haemodynamic response, the synchrony, and interaction between these measures, and the development of new single- and multi-modality image preparation and analysis procedures.
Publisher: IEEE
Date: 2003
Publisher: IEEE
Date: 2006
Publisher: Elsevier BV
Date: 08-2014
Publisher: Springer Science and Business Media LLC
Date: 15-08-2015
Publisher: IEEE
Date: 2003
Publisher: The Optical Society
Date: 07-11-2013
Publisher: IEEE
Date: 07-2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-1997
DOI: 10.1109/2944.605670
Publisher: IEEE
Date: 2005
Publisher: Springer Science and Business Media LLC
Date: 07-03-2018
DOI: 10.1038/S41598-018-22528-X
Abstract: Electroconvulsive therapy (ECT) is an effective treatment option for severe mental illness during pregnancy. However, there is little knowledge about the amount of electric field produced inside the foetus, which is important to understand the effects of ECT on the foetal excitable tissues. Thus, in this paper, the electric field strength inside the foetus was computed and compared to the basic restriction of the International Commission for Non-Ionizing Radiation Protection (ICNIRP). A computational human phantom representing a 30-weeks pregnant female, four types of electrode placements and a range of stimulus pulse width (0.25 ms–2 ms) and frequency (10 Hz–140 Hz) were used to compute the electric field inside the foetus. A linear relationship between the maximum electric field inside the foetal brain and the electrode current was derived. The results suggest that, considering the maximum current output, pulse width, and frequency range of constant-current ECT devices, the electric field produced inside the foetal brain is most likely below the ICNIRP basic restriction. This is based on the practical scenario of a 30-weeks foetus with a bottom-up and head-down foetal position and the mother taller than 1.62 m.
Publisher: Optica Publishing Group
Date: 30-10-2009
DOI: 10.1364/OE.17.020878
Publisher: IEEE
Date: 2003
Publisher: IOP Publishing
Date: 18-10-2013
Publisher: The Optical Society
Date: 10-03-2014
DOI: 10.1364/OE.22.006229
Publisher: IEEE
Date: 2005
DOI: 10.1109/WI.2005.70
Publisher: IEEE
Date: 04-2010
Publisher: IEEE
Date: 08-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2005
Publisher: American Chemical Society (ACS)
Date: 05-01-2018
Abstract: Self-assembly of nanoparticles represents a simple yet efficient route to synthesize designer materials with unusual properties. However, the previous assembled structures whether by surfactants, polymer, or DNA ligands are "static" or "frozen" building block structures. Here, we report the growth of transformable self-assembled nanosheets which could enable reversible switching between two types of nanosheets and even evolving into erse third generation nanosheet structures without losing pristine periodicity. Such in situ transformation of nanoparticle building blocks can even be achieved in a free-standing two-dimensional system and three-dimensional origami. The success in such in situ nanocrystal transformation is attributed to robust "plant-cell-wall-like" ion-permeable reactor arrays from densely packed polymer ligands, which spatially define and confine nanoscale nucleation/growth/etching events. Our strategy enables efficient fabrication of nanocrystal nanosheets with programmable building blocks for innovative applications in adaptive tactile metamaterials, optoelectronic devices, and sensors.
Publisher: IEEE
Date: 08-2011
Publisher: AIP Publishing
Date: 21-03-2016
DOI: 10.1063/1.4944635
Abstract: We design and analyze an ultra-thin metasurface consists of mono-layer all-dielectric fishnet structure. It is demonstrated that coherent perfect absorption (CPA) can be achieved in such a metasurface, and the coherent absorptivity is controllable from 0.38% to 99.85% by phase modulation. The angular selectivity of the metasurface shows the feasibility of CPA in oblique incidence circumstances, where the CPA frequency splits into two frequency bands for TE and TM polarizations. Further study reveals that while retaining CPA, the CPA frequency of the metasurface can be manipulated from 8.56 to 13.47 GHz by solely adjusting the thickness of the fishnet metasurface.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2009
Publisher: IEEE
Date: 12-2007
Publisher: IOP Publishing
Date: 16-01-2018
Publisher: IEEE
Date: 2006
Publisher: Optica Publishing Group
Date: 26-03-2009
DOI: 10.1364/OE.17.005807
Abstract: We present a novel method for maximizing signal gain in continuously pumped silicon-waveguide Raman lifiers made with silicon-on-insulator technology. Our method allows for pump-power depletion during Raman lification and makes use of a variational technique. Its use leads to a system of four coupled nonlinear differential equations, whose numerical solution provides the optimal axial profile of the effective mode area along the waveguide length that maximizes the output signal power for a given lifier length and a preset input (or output) cross-section area. In practice, the optimum profile can be realized by varying the cross-section area of a silicon waveguide along its length by tapering its width appropriately.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2019
Publisher: The Optical Society
Date: 08-06-2012
DOI: 10.1364/OL.37.002295
Publisher: Optica Publishing Group
Date: 2006
DOI: 10.1364/OE.14.010278
Abstract: Designing metropolitan wavelength ision multiplexing (WDM) ring networks with minimum deployment cost is a demanding issue in Telecommunication Network planning . We have already presented lifier placement methods to minimize the number of lifiers in WDM rings for the case all lifiers follow a unique gain model. In this paper, we take into account different types of lifiers with predefined fixed characteristics and costs. We also formulate fiber dispersion limitations on the ring design, and present two efficient methods for placing lifiers and Dispersion Compensation Modules (DCMs) in WDM rings to minimize the total deployment cost of the system. The first method deals with both linear and nonlinear equations and uses a mixed integer nonlinear programming (MINLP) solver where the second method applies the linear approximation of nonlinear constraints, and uses a mixed integer linear programming (MILP) solver to minimize the total cost of the system. We carry out Simulation experiments to confirm the applicability of the methods and compare the results for various network configurations.
Publisher: American Chemical Society (ACS)
Date: 03-12-2020
Publisher: The Optical Society
Date: 10-03-2011
DOI: 10.1364/OL.36.000936
Publisher: AIP Publishing
Date: 29-09-2014
DOI: 10.1063/1.4896972
Abstract: We develop a method for realizing coherent perfect absorption in thin metamaterial systems, based on the coupled-mode theory of Fano resonance. Coherent perfect absorption refers to the complete absorption of symmetric plane waves incident on opposite sides of the system, due to critical coupling into the dissipative degrees of freedom. Using the reflection and transmission spectra measured on a limited number of s les, our theory predicts the precise frequency and metamaterial parameter values required to achieve coherent perfect absorption. The coupled-mode theory and the design method are found to agree well with full-wave numerical simulations of a subwavelength-thickness metamaterial surface with a pair of bright and dark plasmonic modes.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2007
Publisher: Springer Berlin Heidelberg
Date: 2011
Publisher: Hindawi Limited
Date: 2008
DOI: 10.1155/2008/784354
Abstract: An approximate numerical technique for modeling optical pulse propagation through weakly scattering biological tissue is developed by solving the photon transport equation in biological tissue that includes varying refractive index and varying scattering/absorption coefficients. The proposed technique involves first tracing the ray paths defined by the refractive index profile of the medium by solving the eikonal equation using a Runge-Kutta integration algorithm. The photon transport equation is solved only along these ray paths, minimizing the overall computational burden of the resulting algorithm. The main advantage of the current algorithm is that it enables to discretise the pulse propagation space adaptively by taking optical depth into account. Therefore, computational efficiency can be increased without compromising the accuracy of the algorithm.
Publisher: Informa UK Limited
Date: 10-10-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4NR06756H
Abstract: We report on a robust nanotemplating approach to synthesize plasmonic multilayered core-satellite (MCS) nanoassemblies. Templated with gold nanorods, ultrathin Au/Ag alloy cages and satellite gold nanoparticles can be constructed sequentially by galvanic replacement reactions and electrostatic self-assembly, respectively, forming structurally well-defined MCS. The MCS nanoassemblies exhibit strong broadband plasmon resonances from ∼440 to ∼1100 nm, and their resonant features can be fine-tuned by adjusting the size and number density of satellite nanoparticles and by adjusting the thickness of the silica spacer between cage and satellite particles. Such fine-engineered MCS nanoassemblies enable precise programming of the strength and distribution of "hot spots" to maximize the overall enhancement of surface enhanced Raman scattering.
Publisher: Springer Berlin Heidelberg
Date: 2011
Publisher: IOP Publishing
Date: 24-05-2019
Publisher: Optica Publishing Group
Date: 06-11-2009
DOI: 10.1364/OE.17.021179
Publisher: Optica Publishing Group
Date: 11-03-2010
DOI: 10.1364/OE.18.006191
Publisher: Optica Publishing Group
Date: 2007
DOI: 10.1364/OE.15.013282
Abstract: We develop a simple formula for estimating the effect of Four- Wave Mixing (FWM) on received signal quality in coherent optical systems using Orthogonal Frequency Division Multiplexing (OFDM) for dispersion compensation. This shows the nonlinear limit is substantially independent of the number of OFDM subcarriers. Our analysis agrees well with full split-step Fourier method simulations, so allows the nonlinear limit of multi-span systems to be estimated without lengthy simulations.
Publisher: American Physical Society (APS)
Date: 25-04-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2005
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: American Chemical Society (ACS)
Date: 11-11-2021
Publisher: American Physical Society (APS)
Date: 18-09-2018
Publisher: IEEE
Date: 07-2006
Publisher: The Optical Society
Date: 30-01-2014
DOI: 10.1364/OE.22.002681
Publisher: IEEE
Date: 08-2006
Publisher: IEEE
Date: 08-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2014
Publisher: The Optical Society
Date: 09-05-2014
DOI: 10.1364/OE.22.011966
Publisher: MDPI AG
Date: 23-01-2009
DOI: 10.3390/S90100696
Publisher: AIP Publishing
Date: 03-02-2014
DOI: 10.1063/1.4863929
Abstract: A terahertz fishnet metamaterial, consisting of a gallium arsenide substrate sandwiched between multi-layer graphene-dielectric composites, is theoretically studied. Detailed analysis shows that this metamaterial has a left-handed transmission peak accompanied with an abnormal phase dispersion and a clear negative refractive index which originates from simultaneous magnetic and electric resonances. Our structure is unique because it has no metallic parts to achieve the left-handed properties. The most important utility of this metamaterial comes from the fact that its left-handed features can be dynamically controlled by applying external bias to shift the Fermi level in graphene.
Publisher: Optica Publishing Group
Date: 2005
Abstract: Cross-gain modulation between pairs of counter-propagating pulses within a semiconductor optical lifier is used as a pulse delay detector. Unlike previous designs based on differential photodiodes, the difference between average powers of the pulse trains after propagation are deduced from the voltage difference between two contacts on the SOA, eliminating the photodiodes and two optical couplers. Simulations show the design can be improved by adding a third contact. The linearity, sensitivity and noise performance of the design equal or surpass the original design.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2019
Publisher: The Optical Society
Date: 31-05-2019
DOI: 10.1364/PRJ.7.000693
Publisher: The Optical Society
Date: 13-05-2011
DOI: 10.1364/OL.36.001926
Publisher: The Electromagnetics Academy
Date: 2011
DOI: 10.2528/PIER10102901
Publisher: Optica Publishing Group
Date: 16-09-2009
DOI: 10.1364/OE.17.017570
Publisher: The Optical Society
Date: 09-02-2018
DOI: 10.1364/PRJ.6.000157
Publisher: American Physical Society (APS)
Date: 30-06-2014
Publisher: Optica Publishing Group
Date: 18-11-2009
DOI: 10.1364/OE.17.022124
Publisher: The Optical Society
Date: 26-06-2017
DOI: 10.1364/OE.25.015737
Publisher: The Optical Society
Date: 06-03-2012
Publisher: IEEE
Date: 07-2006
Publisher: AIP Publishing
Date: 06-04-2016
DOI: 10.1063/1.4945378
Abstract: We present a comprehensive analysis of a spaser made of a circular shaped highly doped molybdenum disulfide (MoS2) resonator. “Spaser” is an acronym for “surface plasmon lification by stimulated emission of radiation”–a nanoscale source of surface plasmons generated by stimulated emission in a plasmonic resonator which receives energy nonradiatively. By considering localized surface plasmon modes, operation characteristics of the model are analysed, and tunability of the design is demonstrated. We find the optimum geometric and material parameters of the spaser that provides efficient outputs and carryout a comparative analysis with a similar circular spaser made of graphene. Owing to physical and chemical properties of MoS2 and the active medium, the proposed design delivers efficient outputs in terms of spaser mode energy, operating thresholds, Q-factor, and electric field litude. Lower operating thresholds and higher mode energies are notable advantages of the design. Owing to having many superior features to existing similar designs, this MoS2 spaser may be much suited for applications in nanoplasmonic devices.
Publisher: Springer Science and Business Media LLC
Date: 28-12-2015
Publisher: The Optical Society
Date: 19-06-2013
DOI: 10.1364/OE.21.015335
Publisher: The Electromagnetics Academy
Date: 2011
Publisher: Optica Publishing Group
Date: 16-03-2010
DOI: 10.1364/OE.18.006628
Publisher: IEEE
Date: 07-2012
Publisher: IEEE
Date: 05-2008
Publisher: The Optical Society
Date: 15-09-2010
DOI: 10.1364/OL.35.003138
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2008
Publisher: Cambridge University Press
Date: 03-02-2011
Abstract: Over the past two decades, optical lifiers have become of key importance in modern communications. In addition to this, the technology has applications in cutting-edge research such as biophotonics and lab-on-a-chip devices. This book provides a comprehensive treatment of the fundamental concepts, theory and analytical techniques behind the modern optical lifier technology. The book covers all major optical lification schemes in conventional materials, including the Raman and parametric gain processes. The final chapter is devoted to optical gain in metamaterials, a topic that has been attracting considerable attention in recent years. The authors emphasize analytical insights to give a deeper, more intuitive understanding of various lification schemes. The book assumes background knowledge of electrical engineering or applied physics, including exposure to electrodynamics and wave motion, and is ideal for graduate students and researchers in physics, optics, bio-optics and communications.
Publisher: American Chemical Society (ACS)
Date: 10-04-2018
Publisher: IOP Publishing
Date: 13-05-2021
Abstract: We design a tunable plasmonic resonator that may have applications in sensing and plasmon generation—our design uses graphene-based Bragg reflectors of periodically modulated conductivity. Specifically, we explore and utilize the ability to use an array of Gaussian conductivity gratings as fully reflecting mirrors for surface plasmon polaritons (SPPs) propagating along a two-dimensional graphene sheet sandwiched between two dielectric materials. Graphene supports SPPs in the near-infrared to terahertz (THz) regime of the electromagnetic spectrum compared to those observed in metal-dielectric systems. Our resonator is fundamentally different from other similar published resonator designs because the distributed reflectors provide light confinement in both the horizontal and the vertical directions. As a result, the resonator is compact in the vertical-direction as we no longer use traditional mirrors or dielectric assisted gratings. Besides, conventional resonator designs only support a single, fixed resonant frequency, set by the mirror reflectivity and the cavity material’s properties. The versatility of graphene is that its Fermi energy can be electrically varied, thus allowing us to change the peak reflectivity of the graphene Bragg-grating without physically changing its physical dimensions. Therefore, by varying the Bragg wavelength, we can shift the resonance frequency of the cavity. One use of our resonator is in plasmonic lasers. We illustrate this use by analyzing the resonator parameters such as the linewidth and the quality factor of the plasmonic resonator.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2006
Publisher: Optica Publishing Group
Date: 22-01-2020
DOI: 10.1364/OE.380057
Abstract: We investigated the optical binding force in a plasmonic heterodimer structure consisting of two nano-disks. It is found that when illuminated by a tightly focused radially polarized beam (RPB), the plasmon modes of the two nano-disks are strongly hybridized, forming bonding/antibonding modes. An interesting observation of this setup is that the direction of the optical binding force can be controlled by changing the wavelength of illumination, the location of the dimer, the diameter of the nano-disks, and the dimer gap size. Further analysis yields that the inhomogeneous polarization state of RPB can be utilized to readily control the bonding type of plasmon modes and distribute the underlying local field confined in the gap (the periphery) of the dimer, leading to a positive (negative) optical binding force. Our findings provide a clear strategy to engineer optical binding forces via changes in device geometry and its illumination profile. Thus, we envision a significant role for our device in emerging nanophotonics structures.
Publisher: Optica Publishing Group
Date: 2004
Abstract: We show that it is possible to find analytic expressions for characterizing the evolution of signal and noise photon numbers along the active fiber of a forward-pumped Raman lifier with unequal signal and pump loss coefficients. We confirm the validity of the result by comparing the analytical solutions with numerical calculations and by analytically deriving the well-known 3 dB noise figure limit for high Raman gain. Apart from aiding the analysis and design of forward pumped Raman lifiers, these results also enable one to find approximate analytical solutions for bidirectional Raman lifiers and backward pumped Raman lifiers with Rayleigh backscattering and Brillouin scattering.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2016
Publisher: IOP Publishing
Date: 25-06-2014
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-1998
DOI: 10.1109/3.663457
Publisher: The Optical Society
Date: 20-03-2013
DOI: 10.1364/OL.38.001046
Publisher: American Physical Society (APS)
Date: 25-02-2016
Publisher: IEEE
Date: 2007
Publisher: IEEE
Date: 05-2008
Publisher: SPIE-Intl Soc Optical Eng
Date: 07-11-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC45506H
Abstract: We report on the synthesis and characterization of single-crystal caged gold nanorods (CGNRs) which exhibited broadband plasmonic resonances. Redshift of plasmon resonance can be realized by increasing the length, whereas blueshift can be achieved by increasing either the overall width of the cage or the thickness of nanocage walls.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2010
Publisher: The Optical Society
Date: 08-08-2011
DOI: 10.1364/OE.19.016058
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2013
Publisher: Springer Science and Business Media LLC
Date: 23-07-2015
DOI: 10.1038/SREP12140
Abstract: Localised surface plasmons create a non-equilibrium high-energy electron gas in nanostructures that can be injected into other media in energy harvesting applications. Here, we derive the rate of this localised-surface-plasmon mediated generation of hot electrons in nanorods and the rate of injecting them into other media by considering quantum mechanical motion of the electron gas. Specifically, we use the single-electron wave function of a particle in a cylindrical potential well and the electric field enhancement factor of an elongated ellipsoid to derive the energy distribution of electrons after plasmon excitation. We compare the performance of nanorods with equivolume nanoparticles of other shapes such as nanospheres and nanopallets and report that nanorods exhibit significantly better performance over a broad spectrum. We present a comprehensive theoretical analysis of how different parameters contribute to efficiency of hot-electron harvesting in nanorods and reveal that increasing the aspect ratio can increase the hot-electron generation and injection, but the volume shows an inverse dependency when efficiency per unit volume is considered. Further, the electron thermalisation time shows much less influence on the injection rate. Our derivations and results provide the much needed theoretical insight for optimization of hot-electron harvesting process in highly adaptable metallic nanorods.
Publisher: American Physical Society (APS)
Date: 03-01-2022
Publisher: The Optical Society
Date: 16-02-2018
DOI: 10.1364/OE.26.005052
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3506140
Publisher: Springer Science and Business Media LLC
Date: 22-01-2016
Publisher: The Optical Society
Date: 11-02-2019
DOI: 10.1364/OE.27.004944
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2000
DOI: 10.1109/68.896330
Publisher: IOP Publishing
Date: 19-12-2019
Publisher: IEEE
Date: 12-2010
Publisher: The Optical Society
Date: 11-02-2019
DOI: 10.1364/OE.27.005116
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2008
Publisher: American Physical Society (APS)
Date: 28-02-2023
Publisher: Springer Science and Business Media LLC
Date: 26-05-2015
Publisher: Optica Publishing Group
Date: 22-03-2021
DOI: 10.1364/PRJ.414613
Abstract: Plasmonic particle-on-film nanocavities, supporting gap modes with ultra-small volume, provide a great solution to boost light–matter interactions at the nanoscale. In this work, we report on the photoluminescence (PL) enhancement of monolayer MoS 2 using high order modes of an Au nanosphere dimer-on-film nanocavity (DoFN). The high order plasmon modes, consisting of two bonding quadrupoles in the dimer and their images in the Au film, are revealed by combining the polarization-resolved scattering spectra with the numerical simulations. Further integrating the monolayer MoS 2 into the DoFN, these high order modes are used to enhance PL intensity through simultaneously boosting the absorption and emission processes, producing a 1350-fold enhancement factor. It opens an avenue to enhance the light–matter interaction with high order plasmon modes and may find applications in future optoelectronics and nanophotonics devices.
Publisher: IEEE
Date: 2005
Publisher: AIP Publishing
Date: 14-05-2018
DOI: 10.1063/1.5025354
Abstract: We demonstrate that it is possible to derive an approximate analytical expression to characterize the spasing (L-L) curve of a coherently enhanced spaser with 3-level gain-medium chromophores. The utility of this solution stems from the fact that it enables optimization of the large parameter space associated with spaser designing, a functionality not offered by the methods currently available in the literature. This is vital for the advancement of spaser technology towards the level of device realization. Owing to the compact nature of the analytical expressions, our solution also facilitates the grouping and identification of key processes responsible for the spasing action, whilst providing significant physical insights. Furthermore, we show that our expression generates results within 0.1% error compared to numerically obtained results for pumping rates higher than the spasing threshold, thereby drastically reducing the computational cost associated with spaser designing.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2007
Publisher: IEEE
Date: 10-2016
Publisher: American Physical Society (APS)
Date: 17-08-2016
Publisher: The Optical Society
Date: 29-05-2018
Publisher: Optica Publishing Group
Date: 2005
Abstract: Using numerical simulations, we show that cross-gain modulation between pairs of counter-propagating pulses within a semiconductor optical lifier can be used to detect the range and reflectivity of a target, forming a compact time-of-flight laser ranger. The range is deduced from multiple contacts along the SOA. The SOA also provides gain to the optical pulses reflected off the target. A single external component is required to provide pulses into back of the SOA, with the front of the SOA being directly coupled to the target.
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2004
Publisher: Elsevier BV
Date: 10-2007
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4NR06429A
Abstract: We systematically investigated the size- and shape-dependent SERS activities of plasmonic core-shell nanoparticles towards detection of the pesticide thiram. Monodisperse Au@Ag nanocubes (NCs) and Au@Ag nanocuboids (NBs) were synthesized and their Ag shell thickness was precisely adjusted from ∼1 nm to ∼16 nm. All these nanoparticles were used as SERS substrates for thiram detection, and the Raman intensities with three different lasers (514 nm, 633 nm and 782 nm) were recorded and compared. Our results clearly show that: (1) the excitation wavelength discriminated particle shapes regardless of particle sizes, and the maximized Raman enhancement was observed when the excitation wavelength approaches the SERS peak (provided there is significant local electric field confinement on the plasmonic nanostructures at that wavelength) (2) at the optimized laser wavelength, the maximum Raman enhancement was achieved at a certain threshold of particle size (or silver coating thickness). By exciting particles at their optimized sizes with the corresponding optimized laser wavelengths, we achieved a detection limit of roughly around 100 pM and 80 pM for NCs and NBs, respectively.
Publisher: American Physical Society (APS)
Date: 19-06-2017
Publisher: Elsevier BV
Date: 11-2013
Publisher: Institution of Engineering and Technology (IET)
Date: 2012
DOI: 10.1049/EL.2012.2739
Publisher: Elsevier BV
Date: 07-2015
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.NUCMEDBIO.2015.05.001
Abstract: The purpose of this study was to compare two amyloid imaging agents, [(11)C]BF227 and [(18)F]FACT (derivative from [(11)C]BF227) through quantitative pharmacokinetics analysis in human brain. Positron emission tomography studies were performed on six elderly healthy control (HC) subjects and seven probable Alzheimer's disease (AD) patients with [(11)C]BF227 and 10 HC subjects and 10 probable AD patients with [(18)F]FACT. Data from nine regions of interest were analyzed by several approaches, namely non-linear least-squared fitting methods with arterial input functions (one-tissue compartment model(1TCM), two-tissue compartment model (2TCM)), Logan plot, and linearized methods with reference region (Reference Logan plot (RefLogan), MRTM0, MRTM2). We also evaluated SUV and SUVR for both tracers. The parameters estimated by several approaches were compared between two tracers for detectability of differences between HC and AD patients. For [(11)C]BF227, there were no significant difference of VT (2TCM, 1TCM) and SUV in all regions (Student t-test p<0.05) and significant differences in the DVRs (Logan, RefLogan, and MRTM2) and SUVRs in six neocortical regions (p<0.05) between the HC and AD groups. For [(18)F]FACT, significant differences in DVRs (RefLogan, MRTM0, and MRTM2) were observed in more than four neocortical regions between the HC and AD groups (p<0.05), and the significant differences were found in SUVRs for two neocortical regions (inferior frontal coretex and lateral temporal coretex). Our results showed that both tracers can clearly distinguish between HC and AD groups although the pharmacokinetics and distribution patterns in brain for two tracers were substantially different. This study revealed that although the PET amyloid imaging agents [(11)C]BF227 and [(18)F]FACT have similar chemical and biological properties, they have different pharmacokinetics, and caution must be paid for usage of the tracers.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2019
Publisher: American Physical Society (APS)
Date: 08-03-2018
Publisher: The Optical Society
Date: 11-09-2014
DOI: 10.1364/OE.22.022763
Publisher: Optica Publishing Group
Date: 2005
Abstract: Using the principle of energy conservation and laws of geometrical optics, we derive the photon transport equation for turbid biological media with spatially varying isotropic refractive index. We show that when the refractive index is constant, our result reduces to the standard radiative transfer equation and when the medium is lossless and free of scattering to the well known geometrical optics equations in refractive media.
Publisher: The Optical Society
Date: 17-12-2010
DOI: 10.1364/OE.18.027916
Publisher: AIP Publishing
Date: 02-11-2015
DOI: 10.1063/1.4934859
Abstract: We carried out a detailed analysis of a circular graphene spaser made of a circular graphene flake and a quantum cascade well structure. Owing to unique properties of graphene and quantum cascade well structure, the proposed design shows high mechanical and thermal stability and low optical losses. Additionally, operation characteristics of the model are analysed and tunability of the device is demonstrated. Some advantages of the proposed design include compact size, lower power operation, and the ability to set the operating wavelength over a wide range from Mid-IR to Near-IR. Thus, it can have wide spread applications including designing of ultracompact and ultrafast devices, nanoscopy and biomedical applications.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2009
Publisher: The Optical Society
Date: 24-01-2014
DOI: 10.1364/OE.22.002132
Publisher: IEEE
Date: 09-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2010
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2009
Publisher: The Optical Society
Date: 25-06-2014
DOI: 10.1364/OE.22.016408
Publisher: Elsevier BV
Date: 09-2013
Publisher: The Optical Society
Date: 02-2011
DOI: 10.1364/OE.19.002922
Publisher: American Chemical Society (ACS)
Date: 06-11-2014
DOI: 10.1021/JP508108A
Publisher: Wiley
Date: 09-03-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2009
Publisher: The Optical Society
Date: 06-09-2012
Publisher: The Optical Society
Date: 10-12-2012
DOI: 10.1364/OL.37.005151
Publisher: IEEE
Date: 09-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2005
Publisher: IEEE
Date: 12-2008
Publisher: The Optical Society
Date: 18-07-2019
DOI: 10.1364/PRJ.7.000868
Publisher: American Physical Society (APS)
Date: 20-09-2011
Publisher: AIP Publishing
Date: 16-07-2012
DOI: 10.1063/1.4737643
Abstract: The concept of light lification in a system of zero-index metamaterial with gain inserts is studied. We demonstrate that the radiation from a point source embedded in the system can be effectively lified and the net gain is independent of the positions of gain inserts and the source. We further investigate how the net gain grows with the imaginary part of the inserts’ permittivities and find that it saturates when the imaginary part is sufficiently large. It is also shown that the efficiency of lification is significantly reduced when lossy inserts are introduced into the system.
Publisher: The Optical Society
Date: 14-12-2010
DOI: 10.1364/OL.35.004190
Publisher: The Optical Society
Date: 03-02-2015
DOI: 10.1364/OE.23.003236
Publisher: IEEE
Date: 08-2011
Publisher: IEEE
Date: 08-2012
Publisher: The Optical Society
Date: 02-03-2017
DOI: 10.1364/OE.25.005781
Publisher: OSA
Date: 2013
Publisher: Hindawi Limited
Date: 2011
DOI: 10.1155/2011/581810
Abstract: We theoretically study the problem of Raman gain maximization in uniform silicon photonic-crystal waveguides supporting slow optical modes. For the first time, an exact solution to this problem is obtained within the framework of the undepleted-pump approximation. Specifically, we derive analytical expressions for the maximum signal gain, optimal input pump power, and optimal length of a silicon Raman lifier and demonstrate that the ultimate gain is achieved when the pump beam propagates at its maximum speed. If the signal’s group velocity can be reduced by a factor of 10 compared to its value in a bulk silicon, it may result in ultrahigh gains exceeding 100 dB. We also optimize the device parameters of a silicon Raman lifier in the regime of strong pump depletion and come up with general design guidelines that can be used in practice.
Publisher: The Optical Society
Date: 11-07-2013
Publisher: American Physical Society (APS)
Date: 06-07-2021
Publisher: The Optical Society
Date: 13-03-2012
DOI: 10.1364/OE.20.007151
Publisher: IOP Publishing
Date: 10-01-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2013
Publisher: AIP Publishing
Date: 25-03-2013
DOI: 10.1063/1.4799281
Abstract: We present an effective method for actively controlling intrinsic resonances of optical metamaterials using graphene. Exploiting the Fermi level shift and associated variations in optical transitions of graphene due to voltage biasing, we attain the ability to significantly modulate the intrinsic resonance of the fishnet structure. Despite being atomically thin and having a weak optical response, graphene can be strongly coupled with the left-handed resonance of the fishnet metamaterial. We unambiguously demonstrate that the resonant transmission, absorption, and effective constitutive parameters of the graphene-coupled fishnet metamaterial can be precisely controlled by varying the bias voltage.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2010
Publisher: The Optical Society
Date: 08-2016
DOI: 10.1364/OE.24.018332
Publisher: American Chemical Society (ACS)
Date: 02-10-2014
DOI: 10.1021/NN504615A
Abstract: We introduce Plasmene- in analogy to graphene-as free-standing, one-particle-thick, superlattice sheets of nanoparticles ("meta-atoms") from the "plasmonic periodic table", which has implications in many important research disciplines. Here, we report on a general bottom-up self-assembly approach to fabricate giant plasmene nanosheets (i.e., plasmene with nanoscale thickness but with macroscopic lateral dimensions) as thin as ∼40 nm and as wide as ∼3 mm, corresponding to an aspect ratio of ∼75,000. In conjunction with top-down lithography, such robust giant nanosheets could be milled into one-dimensional nanoribbons and folded into three-dimensional origami. Both experimental and theoretical studies reveal that our giant plasmene nanosheets are analogues of graphene from the plasmonic nanoparticle family, simultaneously possessing unique structural features and plasmon propagation functionalities.
Publisher: Optica Publishing Group
Date: 13-02-2009
DOI: 10.1364/OL.34.000536
Abstract: We present approximate analytical expressions describing nonlinear interaction of two optical waves copropagating inside a silicon waveguide in the presence of linear losses, stimulated Raman scattering, and free-carrier absorption. Our approach avoids the undepleted-pump approximation, which we show to be inadequate to describe accurately the Raman-gain process. Based on our calculations, we propose a new generalized definition for the effective length and show that it provides better insight into the impact of nonlinear absorption on Raman lification in silicon waveguides.
Publisher: IEEE
Date: 2005
Publisher: The Optical Society
Date: 28-07-2011
DOI: 10.1364/OE.19.015459
Publisher: IOP Publishing
Date: 09-2020
Publisher: IEEE
Date: 09-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2012
Publisher: The Optical Society
Date: 23-08-2011
DOI: 10.1364/OL.36.003374
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2010
Publisher: IOP Publishing
Date: 03-2013
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: The Optical Society
Date: 05-12-2012
DOI: 10.1364/BOE.4.000015
Publisher: Optica Publishing Group
Date: 24-06-2010
DOI: 10.1364/OL.35.002221
Publisher: The Optical Society
Date: 05-07-2010
DOI: 10.1364/OL.35.002343
Publisher: SPIE
Date: 10-02-2011
DOI: 10.1117/12.873651
Publisher: SPIE
Date: 09-10-2012
DOI: 10.1117/12.930253
Publisher: The Optical Society
Date: 06-09-2011
Publisher: American Physical Society (APS)
Date: 26-03-2020
Publisher: The Optical Society
Date: 13-07-2018
DOI: 10.1364/OL.43.003413
Publisher: The Optical Society
Date: 31-10-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1NR08343K
Abstract: Poly( N -isopropylacrylamide) (PNIPAM) has been used to modify chiral plasmonic nanoparticles. The thermoresponsive studies reveal the impact of achiral dielectric nanoenvironment on chiral plasmonic responses.
Publisher: Optica Publishing Group
Date: 21-08-2008
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2009
Publisher: American Physical Society (APS)
Date: 31-01-2022
Publisher: The Optical Society
Date: 13-08-2012
DOI: 10.1364/OL.37.003444
Publisher: Elsevier BV
Date: 12-2015
Publisher: AIP Publishing
Date: 17-06-2013
DOI: 10.1063/1.4812200
Abstract: We theoretically demonstrate an advanced optical modulator based on graphene-enabled metamaterial with voltage-controllable reflectance. A significant modulation depth of the reflection coefficient is achieved through a voltage biasing of the graphene's Fermi level, leading to an almost instantaneous change in the effective permittivity of the graphene. We show that even a single graphene layer integrated into the structure of a simple metamaterial absorber enables a relative change in the reflectance as high as 361% at near-infrared frequencies. The designed modulator may be used in optical communication systems and biomedical sensing apparatus.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2012
Publisher: Springer Science and Business Media LLC
Date: 09-05-2015
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: The Optical Society
Date: 06-03-2012
DOI: 10.1364/OE.20.006616
Publisher: Optica Publishing Group
Date: 17-10-2008
DOI: 10.1364/OE.16.017792
Abstract: A novel algorithm for mapping the photon transport equation (PTE) to Maxwell's equations is presented. Owing to its accuracy, wave propagation through biological tissue is modeled using the PTE. The mapping of the PTE to Maxwell's equations is required to model wave propagation through foreign structures implanted in biological tissue for sensing and characterization of tissue properties. The PTE solves for only the magnitude of the intensity but Maxwell's equations require the phase information as well. However, it is possible to construct the phase information approximately by solving the transport of intensity equation (TIE) using the full multigrid algorithm.
Publisher: AIP Publishing
Date: 08-04-2014
DOI: 10.1063/1.4870862
Abstract: Despite chiral metamaterials being widely appreciated for their giant optical activity and negative refractive index with respect to the transmitted electromagnetic waves, little research efforts are devoted to effects occurring upon optical reflection from such metamaterials. Here, we theoretically demonstrate highly energy-efficient cross-polarization conversion for a normally incident wave reflecting from metamaterial with a broken four-fold symmetry of chiral structure. We do this by designing metamaterial that makes the polarization plane of a linearly polarized electromagnetic wave reflected from its surface almost perpendicular to the polarization plane of the incident wave. Using reflection from this metamaterial, one can also freely convert between left-handed and right-handed circular polarizations without significant energy loss. The proposed chiral metamaterial may prove useful in electromagnetic communication systems, polarization controllable antennas, and on-chip biomedical sensors.
Publisher: IOP Publishing
Date: 02-12-2019
Publisher: Hindawi Limited
Date: 08-2012
DOI: 10.1155/2012/907183
Abstract: Most metamaterials exhibit pronounced anisotropic properties that are crucial for the understanding of their superior optical behavior, especially when they are integrated into the structure of a plasmonic waveguide. In this paper, we analytically solve the dispersion relation for a slot plasmonic waveguide filled with an anisotropic-stratified metamaterial and reveal that it supports two modes featuring relatively long propagation lengths in the limit of vanishing slot thickness. We classify these modes according to their physical origin and study the variation of their dispersion properties with material parameters.
Publisher: Cold Spring Harbor Laboratory
Date: 23-09-2019
DOI: 10.1101/778357
Abstract: Functional positron emission tomography (fPET) is a neuroimaging method involving continuous infusion of 18-F-fluorodeoxyglucose (FDG) radiotracer during the course of the PET examination. Compared with the conventional bolus administered static FDG PET which provides only a snapshot of the averaged glucose uptake into the brain in a limited dynamic time window, fPET offers a significantly wider time window to study the dynamics of glucose uptake. Several earlier studies have applied fPET to investigate brain FDG uptake and study its relationship with functional magnetic resonance imaging (fMRI). However, due to the unique characteristics of fPET signals, modelling of the fPET signal is a complex task and poses challenges for accurate interpretation of the results. This study applies independent component analysis (ICA) to analyze resting state fPET data, and to compare the performance of ICA and general linear modelling (GLM) for estimation of brain activation in response to tasks. The fPET signal characteristics were compared using GLM and ICA methods to model the fPET visual activation data. Our aim was to evaluate GLM and ICA methods for analyzing task fPET datasets and present ICA method in the analysis of resting state fPET datasets. Using both simulation and in-vivo experimental datasets, we show that both methods can successfully identify task related brain activation. We report fPET metabolic resting state brain networks analyzed using the fPET ICA method in a cohort of healthy subjects. Functional PET provides a unique method to map dynamic changes of glucose uptake in the resting human brain and in response to extrinsic stimulation.
Publisher: American Chemical Society (ACS)
Date: 09-12-2021
Publisher: American Physical Society (APS)
Date: 29-08-2019
Publisher: AIP Publishing
Date: 07-01-2013
DOI: 10.1063/1.4774320
Abstract: Although zero-index metamaterials (ZIMs) have been extensively studied in electromagnetics, their applications in plasmonics have not been investigated so far. In this Letter, we propose strategies for efficient manipulation of surface plasmon polariton (SPP) flow using anisotropic ZIMs. Through rigorous theoretical analysis backed up by full-wave simulations, we suggest two applications of anisotropic ZIMs in plasmonics, namely, adjusting the phase delay of SPPs and guiding SPPs about a rounded metal corner. The proposed applications of ZIMs may prove useful for plasmonic interconnects in integrated ultra-high speed circuitry.
Publisher: IEEE
Date: 07-2012
Publisher: American Physical Society (APS)
Date: 14-07-2015
Publisher: Optica Publishing Group
Date: 10-04-2009
Publisher: IEEE
Date: 06-2013
Publisher: IEEE
Date: 12-2010
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3314272
Publisher: The Optical Society
Date: 12-08-2010
DOI: 10.1364/OE.18.018324
Publisher: Springer Science and Business Media LLC
Date: 28-03-2013
Abstract: We theoretically study the properties of the optimal size distribution in the ensemble of hollow gold nanoshells (HGNs) that exhibits the best performance at in vivo biomedical applications. For the first time, to the best of our knowledge, we analyze the dependence of the optimal geometric means of the nanoshells’ thicknesses and core radii on the excitation wavelength and the type of human tissue, while assuming lognormal fit to the size distribution in a real HGN ensemble. Regardless of the tissue type, short-wavelength, near-infrared lasers are found to be the most effective in both absorption- and scattering-based applications. We derive approximate analytical expressions enabling one to readily estimate the parameters of optimal distribution for which an HGN ensemble exhibits the maximum efficiency of absorption or scattering inside a human tissue irradiated by a near-infrared laser.
Start Date: 2018
End Date: 2021
Funder: Australian Research Council
View Funded ActivityStart Date: 2020
End Date: 2022
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2014
End Date: 05-2017
Amount: $315,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 12-2005
End Date: 12-2007
Amount: $99,696.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2011
End Date: 06-2015
Amount: $540,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2025
Amount: $491,321.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2008
End Date: 12-2011
Amount: $345,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2019
End Date: 12-2022
Amount: $673,460.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2020
End Date: 05-2023
Amount: $460,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 12-2024
Amount: $545,000.00
Funder: Australian Research Council
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