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Showing papers by "Din Ping Tsai published in 2012"


Journal ArticleDOI
TL;DR: This work combines theory and experiment to demonstrate that a carefully designed gradient meta-surface supports high-efficiency anomalous reflections for near-infrared light following the generalized Snell's law, and the reflected wave becomes a bounded surface wave as the incident angle exceeds a critical value.
Abstract: We combine theory and experiment to demonstrate that a carefully designed gradient meta-surface supports high-efficiency anomalous reflections for near-infrared light following the generalized Snell's law, and the reflected wave becomes a bounded surface wave as the incident angle exceeds a critical value. Compared to previously fabricated gradient meta-surfaces in infrared regime, our samples work in a shorter wavelength regime with a broad bandwidth (750-900 nm), exhibit a much higher conversion efficiency (∼80%) to the anomalous reflection mode at normal incidence, and keep light polarization unchanged after the anomalous reflection. Finite-difference-time-domain (FDTD) simulations are in excellent agreement with experiments. Our findings may lead to many interesting applications, such as antireflection coating, polarization and spectral beam splitters, high-efficiency light absorbers, and surface plasmon couplers.

1,105 citations


Journal ArticleDOI
07 Aug 2012-ACS Nano
TL;DR: These findings support a new approach to investigating localized plasmon-induced effects and charge separation in photoelectrochemical processes, and solar water splitting was used herein as platform to explore mechanisms of enhancement of surface plAsmon resonance.
Abstract: Artificial photosynthesis using semiconductors has been investigated for more than three decades for the purpose of transferring solar energy into chemical fuels. Numerous studies have revealed that the introduction of plasmonic materials into photochemical reaction can substantially enhance the photo response to the solar splitting of water. Until recently, few systematic studies have provided clear evidence concerning how plasmon excitation and which factor dominates the solar splitting of water in photovoltaic devices. This work demonstrates the effects of plasmons upon an Au nanostructure–ZnO nanorods array as a photoanode. Several strategies have been successfully adopted to reveal the mutually independent contributions of various plasmonic effects under solar irradiation. These have clarified that the coupling of hot electrons that are formed by plasmons and the electromagnetic field can effectively increase the probability of a photochemical reaction in the splitting of water. These findings suppor...

302 citations


Journal ArticleDOI
TL;DR: In this article, the feasibility of the realization of micromachined tunable metamaterials via structure reconfiguration and the current state of the art in the fabrication technologies of structurally reconfigurable metammaterial elements are reviewed.
Abstract: This paper reviews micromachined tunable metamaterials, whereby the tuning capabilities are based on the mechanical reconfiguration of the lattice and/or the metamaterial element geometry. The primary focus of this review is the feasibility of the realization of micromachined tunable metamaterials via structure reconfiguration and the current state of the art in the fabrication technologies of structurally reconfigurable metamaterial elements. The micromachined reconfigurable microstructures not only offer a new tuning method for metamaterials without being limited by the nonlinearity of constituent materials, but also enable a new paradigm of reconfigurable metamaterial-based devices with mechanical actuations. With recent development in nanomachining technology, it is possible to develop structurally reconfigurable metamaterials with faster tuning speed, higher density of integration and more flexible choice of the working frequencies.

284 citations


Journal ArticleDOI
TL;DR: A terahertz metamaterial with anisotropy tunable from positive to negative values is demonstrated based on the Maltese-cross pattern, which offers new opportunities for the development of teraHertz variable waveplates, tunable filters and polarimetry.
Abstract: Dichroic polarizers and waveplates exploiting anisotropic materials have vast applications in displays and numerous optical components, such as filters, beamsplitters and isolators. Artificial anisotropic media were recently suggested for the realization of negative refraction, cloaking, hyperlenses, and controlling luminescence. However, extending these applications into the terahertz domain is hampered by a lack of natural anisotropic media, while artificial metamaterials offer a strong engineered anisotropic response. Here we demonstrate a terahertz metamaterial with anisotropy tunable from positive to negative values. It is based on the Maltese-cross pattern, where anisotropy is induced by breaking the four-fold symmetry of the cross by displacing one of its beams. The symmetry breaking permits the excitation of a Fano mode active for one of the polarization eigenstates controlled by actuators using microelectromechanical systems. The metamaterial offers new opportunities for the development of terahertz variable waveplates, tunable filters and polarimetry.

226 citations


Journal ArticleDOI
TL;DR: In this paper, a shape-controllable bimetallic gold/silver nanostructured material is synthesized by mixing HAuCl4, AgNO3 and ascorbic acid with shaking for 20 s.
Abstract: This work demonstrates a simple method for synthesizing a shape-controllable bimetallic gold/silver nanostructured material. Spiky star-shaped gold/silver nanoparticles are obtained by mixing HAuCl4, AgNO3 and ascorbic acid with shaking for 20 s. The wide range of star shapes and irregular quasi-spherical nanoparticles is tailored by tuning the ratio of metal precursors. The wavelengths absorbed by the nanoparticles can be tuned from visible light to near infrared by controlling their shape. To maintain the morphology of the nanoparticles, enhance their thermal stability and support their application in biological systems, modified chitosan was utilized for the properties and to keep the material well dispersed in solution in deionized water. The moderate concentration of modified chitosan capped bimetallic star-shaped nanoparticles not only ensured non-toxicity to normal cells and cancer cells, but also promoted high efficiency photothermal ablation of cancer cells. Ultimately, this nanotechnology-driven assay has huge potential for application in rapid synthesis, tunable absorption and non-cytotoxic photothermal therapy for the effective treatment of cancer.

199 citations


Journal ArticleDOI
TL;DR: This paper presents two new related classes of plasmonic metamaterial composed of purposely arranged of four U-shaped split ring resonators that show profound resonant toroidal responses at optical frequencies.
Abstract: Toroidal multipoles are the subject of growing interest because of their unusual electromagnetic properties different from the electric and magnetic multipoles. In this paper, we present two new related classes of plasmonic metamaterial composed of purposely arranged of four U-shaped split ring resonators (SRRs) that show profound resonant toroidal responses at optical frequencies. The toroidal and magnetic responses were investigated by the finite-element simulations. A phenomenon of reversed toroidal responses at higher and lower resonant frequencies has also been reported between this two related metamaterials which results from the electric and magnetic dipoles interaction. Finally, we propose a physical model based on coupled LC circuits to quantitatively analyze the coupled system of the plasmonic toroidal metamaterials.

167 citations


Journal ArticleDOI
TL;DR: It is shown that a laminar liquid flow in an optofluidic channel exhibits spatially variable dielectric properties that support novel wave-focussing and interference phenomena, which are distinctively different from the discrete diffraction observed in solid waveguide arrays.
Abstract: Transformation optics represents a new paradigm for designing light-manipulating devices, such as cloaks and field concentrators, through the engineering of electromagnetic space using materials with spatially variable parameters. Here we analyse liquid flowing in an optofluidic waveguide as a new type of controllable transformation optics medium. We show that a laminar liquid flow in an optofluidic channel exhibits spatially variable dielectric properties that support novel wave-focussing and interference phenomena, which are distinctively different from the discrete diffraction observed in solid waveguide arrays. Our work provides new insight into the unique optical properties of optofluidic waveguides and their potential applications.

164 citations


Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate theoretically and confirm experimentally a new mechanism of resonant electromagnetic transparency, which yields extremely narrow isolated symmetric Lorentzian lines of full transmission in metamaterials.
Abstract: We demonstrate theoretically and confirm experimentally a new mechanism of resonant electromagnetic transparency, which yields extremely narrow isolated symmetric Lorentzian lines of full transmission in metamaterials. It exploits the long sought non-trivial non-radiating charge-current excitation based on toroidal dipole moment, predicted to generate waves of gauge-irreducible vector potential in the complete absence of scattered electromagnetic fields.

161 citations


Journal ArticleDOI
TL;DR: In this paper, the effect localized surface plasmon resonance (LSPR) of Au nanoparticles on the photocatalytic activity of TiO2 film was studied.
Abstract: The effect localized surface plasmon resonance (LSPR) of Au nanoparticles was studied on the photocatalytic activity of TiO2 film. We used the thermal hydrolysis method to prepare 300 nm TiO2 film and the sodium citrate reduced method to synthesize gold nanoparticles. The photocatalytic activities of Au/TiO2, Au@SiO2/TiO2, and TiO2 films were evaluated by the degree of MB photodegradation under similar conditions with simultaneous UV (365 nm) and visible-light (400 nm Au/TiO2 > TiO2. Although the SiO2 shell prevented the electron trap effect, the MB photodegradation efficiency of Au@SiO2/TiO2 was superior to that of Au/TiO2 because its LSPR was much higher. To validate the experimental results, the electric field intensity around the gold nanoparticles was simulated by the finite element method (FEM). In the presence of gold nanoparticles, the LSPR effect increased the surrounding intensity of e...

102 citations


Journal ArticleDOI
TL;DR: In this article, a three-dimensional photonic metamaterial consisting of an array of erected U-shape plasmonic gold nanostructures that exhibits the PIT phenomenon with magnetic dipolar interaction between magnetic meta molecules is presented.
Abstract: In a laser-driven atomic quantum system, a continuous state couples to a discrete state resulting in quantum interference that provides a transmission peak within a broad absorption profile the so-called electromagnetically induced transparency (EIT). In the field of plasmonic metamaterials, the subwavelength metallic structures play a role similar to atoms in nature. The interference of their near-field coupling at plasmonic resonance leads to a plasmon induced transparency (PIT) that is analogous to the EIT of atomic systems. A sensitive control of the PIT is crucial to a range of potential applications such as slowing light and biosensor. So far, the PIT phenomena often arise from the electric resonance, such as an electric dipole state coupled to an electric quadrupole state. Here we report the first three-dimensional photonic metamaterial consisting of an array of erected U-shape plasmonic gold nanostructures that exhibits PIT phenomenon with magnetic dipolar interaction between magnetic meta molecules. We further demonstrate using a numerical simulation that the coupling between the different excited pathways at an intermediate resonant wavelength allows for a pi phase shift resulting in a destructive interference. A classical RLC circuit was also proposed to explain the coupling effects between the bright and dark modes of EIT-like electromagnetic spectra. This work paves a promising approach to achieve magnetic plasmon devices.

76 citations


Journal ArticleDOI
TL;DR: In this paper, a femtosecond laser-induced forward transfer for high-throughput and efficient fabrication of periodic multilayer plasmonic metamaterials is demonstrated.
Abstract: A novel method based on femtosecond laser-induced forward transfer for high-throughput and efficient fabrication of periodic multilayer plasmonic metamaterials is demonstrated. With precisely controlling laser raster path applied on sputtered multilayer thin films, the laser-ablated materials can be transferred to another substrate leaving the fabricated multilayer structure on the original substrate. Subsequently, three-dimensional metamaterials can be made by multilayer structuring. Moreover, all the experimental results show that to create such multilayer split resonant rings (SRRs) with uniform profile, the laser fluence should be fine controlled under proper conditions. The optical property of fabricated multilayer SRR array is investigated by optical measurements and finite-difference time-domain simulations, showing various resonant modes in the middle-IR region. The calculated induced current distributions exhibit rich resonance properties of the structures as well. This work markedly extends the laser direct writing technique to a wide application in fabricating complicated metamaterials and plasmonic devices efficiently.

Journal ArticleDOI
26 Jun 2012-ACS Nano
TL;DR: Using a femtosecond laser, the laser-direct-writing technique is transformed into a highly efficient method that can process AgO(x) thin films into Ag nanostructures at a fast scanning rate of 2000 μm(2)/min.
Abstract: Using a femtosecond laser, we have transformed the laser-direct-writing technique into a highly efficient method that can process AgOx thin films into Ag nanostructures at a fast scanning rate of 2...

Journal ArticleDOI
TL;DR: In this article, the plasmonic resonance modes and coupling effects of single silver nanobeads and dimers were investigated using the three-dimensional finite element method, and it was shown that only the bonding mode can be found for low-refractive index cores.
Abstract: We investigate the plasmonic resonance modes and coupling effects of single silver nanobeads and silver nanobead dimers. Numerical investigation using the three-dimensional finite element method indicates that silver nanobeads exhibit two plasmonic resonances corresponding to the bonding and anti-bonding modes, respectively. The boundary symmetry on the inner and outer surfaces of the silver nanobeads can be broken by increasing the refractive indices of the cores filling the dielectric holes. It is shown that only the bonding mode can be found for low-refractive index cores, whereas both bonding and anti-bonding modes can be found for high-refractive index cores.

Journal ArticleDOI
TL;DR: In this article, a self-assembly strategy for fabricating 3D metamaterials is presented, which represents the desired 3D curving prongs of the split ring resonators (SRRs) erected by metal stress force with appropriate thin film parameters.
Abstract: We demonstrate a self-assembly strategy for fabricating three dimensional (3D) metamaterials. This strategy represents the desired 3D curving prongs of the split ring resonators (SRRs) erected by metal stress force with appropriate thin film parameters. Transmittance spectra and field patterns corresponding to each resonance modes are calculated by finite element method (FEM). The eigen-modes of the SRRs can be excited by normal illumination with polarization state parallel to the erected SRRs, which are unlike for the cases of planar SRRs. This method opens a promising fabrication process for the application of tailored 3D SRRs.

Patent
21 Jan 2012
TL;DR: In this article, a non-visible particle detection device includes an optical module capable of converting an ionizing radiation into visible light, which is attached to the image capturing module of a mobile device.
Abstract: A non-visible particle detection device includes an optical module capable of converting an ionizing radiation into visible light. The optical module includes has an attachment unit that is configured to removably attach the optical module to the image capturing module of a mobile device. The image capturing module generates a photon digital image based on the photons converted from the ionizing radiation. The mobile device can be implemented with a radiation dose determining module to execute a radiation dose equivalent calculation method. Based on the pixel brightness analysis of the photon digital image, the radiation equivalent dose can be determined. This method sums up the total brightness of all pixels in the images, determines whether the total brightness is smaller than the minimum effective brightness, and determines the radiation equivalent dose when the total brightness is equal to or larger than the minimum effective brightness.

Journal ArticleDOI
TL;DR: The fabricated GaN-based membrane HCG reflectors revealed high reflectivity at 460 nm band with large stopband width of 60 nm in the TE polarization measured by using the micro-reflectivity spectrometer, and showed good agreement with simulated ones.
Abstract: The GaN-based membrane high contrast grating (HCG) reflectors have been fabricated and investigated. The structural parameters including grating periods, grating height, filling factors and air-gap height were calculated to realize high reflectivity spectra with broad bandwidth by the rigorous coupled-wave analysis and finite-difference time-domain method. Based on the optimized simulation results, the GaN-based membrane HCGs were fabricated by e-beam lithography and focused-ion beam process. The fabricated GaN-based membrane HCG reflectors revealed high reflectivity at 460 nm band with large stopband width of 60 nm in the TE polarization measured by using the micro-reflectivity spectrometer. The experimental results also showed a good agreement with simulated ones. We believe this study will be helpful for development of the GaN-based novel light emitting devices in the blue or UV region.

05 Jan 2012
TL;DR: A self-assembly strategy for fabricating three dimensional (3D) metamaterials that represents the desired 3D curving prongs of the split ring resonators (SRRs) erected by metal stress force with appropriate thin film parameters is demonstrated.
Abstract: This paper demonstrates a self-assembly strategy for fabricating three dim ensional (3D) metamaterials. This strategy represents the desired 3D curving prongs of the split ring resonators (SRRs) erected by metal stress force with appropriate thin film parameters. Transmittance spectra and field distribution corresponding to each resonance modes are calculated by finite element method (FEM). The eigen-modes of the SRRs can be excited by normal illuminati on with polarization state parallel to the erected SRRs, which are unlike for the cases of planar SRR s . This method opens a promising fabrication process for the application of tailored 3D SRRs .

Journal ArticleDOI
TL;DR: A transformation optofluidic Y-branch splitter with large-angle bending and tuning based on the design of a spatially variable index is introduced, which has high potential applications in biological, chemical and biomedical solution measurement and detection.
Abstract: Transformation optics is a new art of light bending by designing materials with spatially variable parameters for developing wave-manipulation devices. Here, we introduce a transformation optofluidic Y-branch splitter with large-angle bending and tuning based on the design of a spatially variable index. Differing from traditional splitters, the optofluidic splitter is achieved in an inhomogeneous medium by coordinate transformation. The designed bidirectional gradient index (GRIN) distribution can be achieved practically by the convection-diffusion process of liquid flowing streams. The transformation optofluidic splitter can achieve a much larger split angle with little bend loss than the traditional ones. In the experiments, a large tunable split angle up to 30° is achieved by tuning the flow rates, allowing optical signals to be freely transferred to different channels. Besides the symmetrical branch splitting, asymmetrical Y-branch splitting with approximately equal power splitting is also demonstrated by changing the composition of the liquids. The optofluidic splitter has high potential applications in biological, chemical and biomedical solution measurement and detection.

Journal ArticleDOI
TL;DR: An innovative active imaging device named gain-assisted hybrid-superlens hyperlens is proposed and an excellent resolution power much better than the diffraction limit value can be achieved.
Abstract: We propose an innovative active imaging device named gain-assisted hybrid-superlens hyperlens and examine its resolving power theoretically. This semi-cylindrical device consists of a core of semi-cylindrical super-lens and a half cylindrical outer shell of hyperlens. Both the superlens and hyperlens parts of the device are appropriately designed multi-layered metal-dielectric structures having indefinite eigenvalues of dielectric tensors. The dielectric layers of the hyperlens are doped with Coumarin, which play the role of gain medium. The gain medium is analyzed thoroughly using a generic four-level system model, and the permittivity of the gain medium is extracted from this analysis for simulating the imaging characteristics of the device. According to our simulation at wavelength of 365 nm, an excellent resolution power much better than the diffraction limit value can be achieved.

Journal ArticleDOI
TL;DR: The sulfonated graphene nanosheet-supported platinum (s-Pt/GNS) catalyst synthesized via a simple thermal treatment in the presence of concentrated sulfuric acid was reported in this article.

Journal ArticleDOI
TL;DR: The physics behind strikingly different orders of magnitude in enhancement that have been observed are shown, fundamental explanation for not observing quenching of Raman processes is provided, and the path to optimization of both photoluminescence and Raman enhancement is outlined.
Abstract: We present a comparative study on the enhancement of photoluminescence and Raman processes by a single metal nanoparticle. Taking an analytical approach, we show the physics behind strikingly different orders of magnitude in enhancement that have been observed, provide fundamental explanation for not observing quenching of Raman processes, and outline the path to optimization of both photoluminescence and Raman enhancement.

Journal ArticleDOI
TL;DR: Observations reveal that surface plasmon waves can be highly directed and focused via this nanofence pattern and demonstrate the potential applications of these nanophotonic devices.
Abstract: Using femtosecond laser-induced forward transfer techniques we have fabricated gold dots and nanoparticles on glass substrates, as well as nanobumps on gold thin film. The surface morphologies of these structures with different laser fluences and film thicknesses are investigated. We also study the focusing and defocusing properties of the nanofence-an arranged nanobump pattern-by the total-internal reflection microscope. Observations reveal that surface plasmon waves can be highly directed and focused via this nanofence pattern. Results are in good agreement with the simulation results using the finite-element method and demonstrate the potential applications of these nanophotonic devices. Furthermore, we utilize high laser energy to fabricate plasmonic waveguides, and also succeed in transferring the waveguides to another substrate. The attenuation rates of the light propagating in the waveguides are observed to achieve 0.31 dB μm(-1) and 0.48 dB μm(-1) on the target and receiver sides, respectively.

Journal ArticleDOI
TL;DR: A rotating disk reactor that significantly increases the process efficiency has been designed and evaluated for application to photocatalytic decomposition of dye pollutants in aqueous solutions and the simulation results show promising scale-up potential of the reactor.
Abstract: Solar wastewater treatment based on photocatalytic reactions is a green process that utilizes renewable energy resources and minimizes secondary pollution. Reactor design plays an important role in promoting treatment efficiency and throughput density (based on unit volume of the reactor). A rotating disk reactor that significantly increases the process efficiency has been designed and evaluated for application to photocatalytic decomposition of dye pollutants in aqueous solutions. In this process, a novel multi-layer rotating disk reactor (MLRDR) was presented. Photocatalyst (TiO2) particles are immobilized on the surfaces of disks. Within each layer of the reactor, methyl orange aqueous solution is allowed to flow from the center of the disk in a radial direction along the surface of the disk, which is rotating at high speed and is irradiated with UV lamps. The effluent is then directed to the center of another layer that lies underneath. Up to four stacked layers have been tested in this study, and the effects due to the number of the layers and volumetric flow rate on reaction conversion are investigated. The efficiency of this photocatalytic reactor exhibits complex dependence on these parameters. With selected operating conditions, conversions greater than 95% can be achieved within seconds of residence time. Design equations of the reactor have been derived based on fluid dynamics and kinetic models, and the simulation results show promising scale-up potential of the reactor.

Journal ArticleDOI
TL;DR: In this article, a near-field cover glass slip (NF-CGS) was developed to improve the resolution of optical microscopy beyond the diffraction limit, where a multi-layered structure of cover glass/ZnS-SiO2 (130 nm)/AgOx (15 nm)/ ZnS−SiO 2 (40 nm) was employed to generate the optical coupling effect for increasing the contrast and enhancing resolution of imaging.
Abstract: This study presents a novel near-field optics technology. A near-field cover glass slip (NF-CGS) was developed to improve the resolution of optical microscopy beyond the diffraction limit. A multi-layered structure of cover glass/ZnS-SiO2 (130 nm)/AgOx (15 nm)/ ZnS-SiO2 (40 nm) was employed to generate the optical coupling effect for increasing the contrast and enhancing resolution of imaging. This novel innovation is expected to be employed in near-field imaging techniques for samples in different environments because of its simplicity, rapid laser scanning, and minimal costs. Experimental results of 500 nm, 200 nm, and 100 nm standard polystyrene nanospheres on NF-CGS and normal cover glass are demonstrated and imaged by using a laser scanning confocal microscope.

Journal ArticleDOI
TL;DR: In this article, Fan-shaped forward scattering of an individual nanobump is observed, and a quarter-circle structure composed of nanobumps is exploited to manipulate scattering from each Nanobump.
Abstract: Backward and forward scattering of surface plasmonic wave interactions from gold nanobumps on the surface of a 30-nm gold thin film demonstrate three-dimensional (3-D) focusing and diverging properties. Fan-shaped forward scattering of an individual nanobump is observed. A quarter-circle structure composed of nanobumps is exploited to manipulate scattering from each nanobump. Experimental results show that 3-D propagation vectors generated by the gold nanobumps with their heights of 16 nm can deflect the surface plasmonic waves to produce 3-D focusing at 3.6 μm above the surface of the gold film. We clearly demonstrate that 3-D forward and backward focusing from gold nanobumps are with different amplitudes and directions of the vertical propagation vectors.

Journal ArticleDOI
TL;DR: Handedness-sensitive surface plasmon polariton emission in mirror-symmetric ensembles of elliptical nanoholes made in a thin gold film is reported and an analytical model based on anisotropic polarizability of each nanohole is presented.
Abstract: We report handedness-sensitive surface plasmon polariton (SPP) emission in mirror-symmetric ensembles of elliptical nanoholes made in a thin gold film. It is found by means of rigorous calculations and scanning near-field optical microscopy that SPP excitation direction depends on the direction of circularly polarized illumination E-vector rotation. An analytical model based on anisotropic polarizability of each nanohole is presented. Both the experimental and calculated results are in agreement with Curie’s principle, and contribute to better understanding of symmetry in plasmonics.

Journal ArticleDOI
TL;DR: In this paper, the Goos-Hanchen (GH) lateral shift of a reflected light beam from various devices based on the surface plasmon (SP) excitation at metal-dielectric interfaces was investigated.
Abstract: Optical sensing of temperature variations is explored by studying the Goos–Hanchen (GH) lateral shift of a reflected light beam from various device based on the surface plasmon (SP) excitation at metal-dielectric interfaces. Both the Kretchman and the Sarid geometry will be considered, where the temperature variations of the GH shifts associated with excitation of both the regular and the long-range SP will be studied. It is found that while the SP-induced shifts and their temperature sensitivities are much greater than those from a bare metallic surface, these sensitivities are comparable between the shifts induced by the different kinds of SP, although the long-range SP can in general induce much greater values in the GH shifts, as reported recently in the literature.

Journal ArticleDOI
TL;DR: In this paper, the optical response of graded-index spherical metallic nanoparticles is studied in the modified long wavelength approximation with electrodynamic effects accounted for to the lowest order of the inverse of the wavelength.
Abstract: The optical response of graded-index spherical metallic nanoparticles is studied in the modified long wavelength approximation with electrodynamic effects accounted for to the lowest order of the inverse of the wavelength. An effective-medium approach is adopted which leads to the conclusion that the first-order dynamical effects will enter mainly via the polarizability and not the effective dielectric function of the system. Numerical studies using various graded Drude functions show that these effects are not only significant for particles of large sizes but can also be appreciable for smaller particles with varying index profile.

Patent
21 Jan 2012
TL;DR: A handheld facial analyzing device based on estimating the characteristics of human facial skin includes an image capturing unit, a memory unit, display unit, processing unit, and a user interface as mentioned in this paper.
Abstract: A handheld facial analyzing device based on estimating the characteristics of human facial skin includes an image capturing unit, a memory unit, a display unit, a processing unit, and a user interface. The processing unit receives an instruction from the user interface corresponding to a position on the image data displayed by the display unit and generates a facial analysis result having information on skin roughness and wrinkles from the gray-scale image data corresponding to the image data in accordance to the position in the instruction.

Patent
29 Nov 2012
TL;DR: In this article, the authors proposed a radiation detection device consisting of a mobile phone, an optical module, calculation, and notification, which can be separated from the mobile phone to measure and evaluate an equivalent dose of radiation.
Abstract: PROBLEM TO BE SOLVED: To provide a highly convenient radiation detection deviceSOLUTION: A radiation detection device 10 includes a mobile phone 20, an optical module 11, calculation means 22, and notification means 23 The mobile phone 20 has a camera 21 and a display screen 24 The optical module 11 is provided on the mobile phone 20 and can be separated from the mobile phone 20 The calculation means 22 measures and evaluates an equivalent dose of radiation The notification means 23 dynamically displays calculation results such as the equivalent dose of radiation or an energy spectrum of radiation on the display screen 24 of the mobile phone 20