Showing papers by "Din Ping Tsai published in 2008"
TL;DR: The proposed structure exhibits a redshifted localized surface plasmon that can be tuned over an extended wavelength range by varying the dielectric constant in DHs and the thickness of the nanocylinder silver shell.
Abstract: Near-field optical properties and surface plasmon effects in a silver-shell nanocylinder pair with five different dielectric holes (DHs) that interact with a transverse magnetic mode incident plane wave are simulated by use of the finite-element method, which includes the investigation of particle-particle interaction. The proposed structure exhibits a redshifted localized surface plasmon that can be tuned over an extended wavelength range by varying the dielectric constant in DHs and the thickness of the nanocylinder silver shell. The increase in the near-field intensity is attributed to a larger effective size of DH that is filled with a higher refractive medium.
63 citations
TL;DR: In this article, a high birefringence and low loss index-guiding photonic crystal fiber (PCF) using the complex unit cells in cladding by the finite-element method was proposed.
60 citations
TL;DR: In this article, a novel high-birefringence index-guiding photonic crystal fiber (PCF) is proposed, which is composed of a solid silica core and a cladding with two differently sized squeezed elliptical air-holes.
Abstract: We propose a novel high-birefringence index-guiding photonic crystal fiber (PCF). This PCF is composed of a solid silica core and a cladding with two differently sized squeezed elliptical air-holes. The mode birefringence of a fundamental mode in such PCFs is analyzed numerically by the finite-element method. Numerical results reveal that an extraordinarily high modal birefringence at the excitation wavelength of λ=1550 nm, 2.6×10-2, is acquired. The contributions of the cladding with two different sizes of air-hole ellipticity, the center-to-center distance between the air-holes, and the the number of cladding rings as well as the confinement loss to the birefringence are systematically evaluated. The evolution of birefringence with the structural variations shows that our highly birefringent fiber can be designed in a controlled manner.
51 citations
TL;DR: In this paper, a seed-mediated growth method for the synthesis of iron oxide nanoparticles with tunable size distribution and magnetic properties was proposed. But the size distribution of seed and iron oxide was not investigated.
Abstract: We report here the development of a seed-mediated growth method for the synthesis of iron oxide nanoparticles with tunable size distribution and magnetic properties. We have investigated the size distribution of seed as well as iron oxide nanoparticles during the growth process using transmission electron microscopy (TEM). It has been observed that the distribution of size gradually becomes narrow with time via the intraparticle ripening process and Oswald ripening process. The magnetization measurements were performed using a superconducting quantum interference device (SQUID) from room temperature t o5Kt odetermine the effect of size distribution on the blocking temperature (Tb) and splitting temperature (Tsplitting). The thermogravimetric analyses exhibited the size-dependent weight loss of the magnetic nanoparticles. The in vitro cytotoxicity tests were also performed to determine the cell viability as a function of size and concentration of the magnetic nanoparticles.
50 citations
TL;DR: In this article, a simulation of scattering field interactions and surface plasmon resonance (SPR) in coupled silver nanospheres is performed using the finite element method, which includes the influences of near-field enhancements of electric field by the particle sizes, separation distances, propagation directions, as well as the polarizations of the incident wave.
Abstract: Scattering field interactions and surface plasmon resonance (SPR) in coupled silver nanospheres are simulated by using the finite-element method, which includes the influences of near-field enhancements of electric field by the particle sizes, separation distances, propagation directions, as well as the polarizations of the incident wave. The proposed structures exhibit a red- and blue-shifted that can be tuned by varying the particle sizes and the separation distances, respectively. Implications for surface-enhance Raman scattering and nano-optics are discussed in three-dimensional models. The evolution of SPR and nano-photonic device with the structural variations can be designed in a controlled manner.
43 citations
TL;DR: In this article, the nanoscale surface electrical properties of aluminum zinc oxide (AZO) films that were prepared by pulsed laser deposition (PLD) at various substrate temperatures for use as anode materials in polymer light-emitting diodes (PLEDs).
Abstract: Conducting atomic force microscopy and scanning surface potential microscopy were adopted to study the nanoscale surface electrical properties of aluminum zinc oxide (AZO) films that were prepared by pulsed laser deposition (PLD) at various substrate temperatures for use as anode materials in polymer light-emitting diodes (PLEDs). Experimental results indicate that when substrate temperatures exceed 100°C, the local conductivity and work function are positively correlated with the concentrations of Al dopant and O2− on AZO surface. When the substrate temperature is approximately 150°C, the percentage coverage of conducting regions of the AZO surface and the mean work function are 90.20% and 4.85eV, respectively. Additionally, both microcosmic uniformities meet the standard applied to PLEDs. This low-temperature condition for PLD significantly reduces the yield rate of impurities when AZO vacuum evaporation is performed on a plastic substrate, supporting various applications of AZO films.
42 citations
TL;DR: In this paper, a localized surface plasmon polariton (LSPP) mode was used for an IR reflection-type notch filter with an ultrahigh immunity for the angular deviation.
Abstract: A plasmonic infrared (IR) filter was experimentally and theoretically investigated. A localized surface plasmon polariton (LSPP) mode which was angle-independent in almost fully incident angle was observed. Through the use of the LSPP mode, an IR reflection-type notch filter with an ultrahigh immunity for the angular deviation was realized. An angle-independent reflection dip was designed at lambda = 6.2 mum with a full-width at half-maximum of 0.5 mum. The experimental result shows that the position and the line shape of the resonant dip at lambda = 6.2 mum remain the same for an increasing incident angle from 20deg to 60deg. The optical properties can be engineered by tuning thickness of the cavity layer. The proposed notch filter presents a large angular tolerance means that the superior angular stability makes it more feasible as it is put into practical applications.
32 citations
TL;DR: 3-dimensional finite-difference time-domain method is used to investigate surface polariton coupling between two nano-recording marks which are of different shapes and the influence of these coupling effects on read-out reflection signal will be discussed.
Abstract: We use 3-dimensional finite-difference time-domain method to investigate surface polariton coupling between two nano-recording marks which are of different shapes. The different coupling characteristics and the influence of these coupling effects on read-out reflection signal will be discussed.
26 citations
TL;DR: An optical pump‐probe system (static media tester) is used to measure the optical response of a phase‐change recording layer (Ge2Sb2Te5) and demonstrate the high contrast of optical recording with a ZnOx nanostructured thin film in short pulse durations.
Abstract: Recently, use of nanostructured materials as a near-field optical active layer has attracted a lot of interest. The non-linear optical properties and strong enhancements of metallic oxide nanostructured thin films are key functions in applications of promising nanophotonics. For the importance of ultra-high density optical data storage, we continue investigating the ultra-high density recording property of near-field optical disk consisting of zinc oxide (ZnO(x)) nanostructured thin film. A carrier-to-noise ratio above 38 dB at a recording mark size of 100 nm can be obtained in the ZnO(x) near-field optical disk by a DVD driver tester directly. In this article, we use an optical pump-probe system (static media tester) to measure the optical response of a phase-change recording layer (Ge(2)Sb(2)Te(5)) and demonstrate the high contrast of optical recording with a ZnO(x) nanostructured thin film in short pulse durations. Also, we investigate the dependence of writing power and the optical response in conventional re-writable recording layers and the phase-change material with ZnO(x) nanostructured thin film.
10 citations
TL;DR: In this article, the temperature dependence of the optical/spectroscopic properties of metallic nanoparticles (in particular nanoshells) including absorption, scattering, and enhanced-Raman scattering for admolecules is studied via theoretical modeling.
9 citations
TL;DR: In this article, a numerical study of high birefringence induced by four types of elliptical air holes in photonic crystal fibers (PCFs) was carried out by using the finite element method.
Abstract: This paper presents a numerical study of high birefringence induced by four types (Type 1–4) of different sizes of elliptical air holes in photonic crystal fibers (PCFs). The numerical simulation is carried out by using the finite element method. The statistical correlations between the birefringence and the various parameters are obtained. Based on our results, the birefringence is found to be largely dependent on the variation of the normalized frequency, size ratio, effective area of the circular and elliptical air holes, and the ring number of cladding. Two of our suggested structures, Type 1 and Type 3, can considerably enhance the birefringence in PCFs leading to values as high as and , respectively, which are much higher than that obtained by a conventional step-index fiber.
TL;DR: In this paper, the concept of reciprocity symmetry for nonrelativistic quantum mechanics with nonlocal interactions is established for matter-wave propagation, with previous results in the literature extended to include non-local interactions, where it is shown that reciprocity can be violated for the motion of a charged particle in an external electromagnetic field.
Abstract: The concept of reciprocity symmetry for matter-wave propagation is established for nonrelativistic quantum mechanics with previous results in the literature extended to include nonlocal interactions Examples are given for cases with both local and nonlocal potentials, where we show in particular that reciprocity can be violated for the motion of a charged particle in an external electromagnetic field In addition, this symmetry is applied to interpret a recent analysis [Phys Rev A 64, 042716 (2001)] on the symmetry of transmission through one-dimensional complex potentials, with the emphasis that the validity of reciprocity can go beyond that of time-reversal symmetry, such as in the presence of absorption in which the latter symmetry breaks down
TL;DR: The calculated results demonstrate that each mode of plasmonic resonance has maximum resonance strength at a particular film thickness of the metamaterial, and show that there might be an effective light propagation length that will let the coupling efficiency between evanescent light source and SPs resonance become a maximum.
Abstract: The characteristics of plasmonic resonance in a dielectric-sandwiched metamaterial film at visible wavelengths of 650 and 568 nm have been investigated (for both p- and s-polarized light). Our calculated results demonstrate that each mode of plasmonic resonance has maximum resonance strength at a particular film thickness of the metamaterial. We also demonstrated that the effect of evanescent field enhancement is due to plasmonic resonances of the sandwiched metamaterial system. And the stronger the plasmonic resonance strength the larger the evanescent field is enhanced at the interfaces of the metamaterial film. Also we see that the plasmonic resonances in a sandwiched metamaterial are influenced not only by the materials that constitute the interfaces but also by the thickness of surrounding dielectrics or distance between evanescent light source and metamaterial film. Finally, our results show that there might be an effective light propagation length that will let the coupling efficiency between evanescent light source and SPs resonance become a maximum. These properties of plasmonic resonances to structure parameters of metamaterial film and its surrounding dielectrics provide a useful way to control the optical responses of an optoelectronic device when the wavelength of light source is fixed. That is, by suitably choosing light polarizations, thickness of the metamaterial thin film or the surrounding dielectrics and the position of evanescent light source, it is possible to modulate the plasmonic resonance wavenumber or resonance strength of the system. Therefore, the optical responses of the system can be modulated. Our results will be helpful for the structure design to control the behaviours of coupled plasmonic resonances and consequently the optical properties of the dielectric-sandwiched metamaterial film.
TL;DR: In this paper, the super-resolution properties of super-RENS were analyzed by a simplified Fourier optics approach using statistical averages of near-field optical disks with random nanostructures.
Abstract: Super-resolution properties of super-resolution near-field structures (super-RENS) are analyzed by a simplified Fourier optics approach. Statistical averages of near-field optical disks with random nanostructures are calculated to realize their general behaviors. Averaged readout waveforms of near-field optical disks with random apertures are calculated numerically. The resolution of a near-field optical disk is determined by the size and shape of the random nanostructure.
TL;DR: In this article, the plasmon and distribution effects of collective localized surface plasmons between incident light and active layer of PtO x -type super resolution near field structure (super-RENS) have been studied using finite-difference time-domain method.
01 Oct 2008
TL;DR: In this paper, a plasmonic liquid-liquid (PLL) waveguide using Au nano-particles (NPs) colloidal solution is configured on a micro-optical-fluidic-system (MOFS) chip for the interest extensions of SPR assisted measurements.
Abstract: A plasmonic liquid-liquid (PLL) waveguide using Au nano-particles (NPs) colloidal solution is configured on a micro-optical-fluidic-system (MOFS) chip [1] for the interest extensions of surface plasmon resonance (SPR) assisted measurements. For characterizing the PLL waveguide, the propagating modes are studied with the scattering images and the measurement of the transmission spectrum. Controllability on the modes of SPR propagation in PLL waveguide is demonstrated.
TL;DR: In this paper, the authors investigated the transmission properties of a plasmonic multilayer structure with a defect, which can be a nanoslit, and showed that the increased transmission factor has a maximum of 5.5 and it also performs loose angle tolerances of 10 and 20° for 1 and 3 dB losses, respectively.
Abstract: The transmission properties of a plasmonic multilayer structure with a defect, which can be a nanoslit, were investigated. The transmission spectrum through the slit embedded in the plasmonic multilayer structure presents a Fano-like shape at a transmission peak of 580 nm. The enhanced transmission is due to the localized surface plasmon resonant within the cavity of the plasmonic multilayer. The increased transmission factor has a maximum of 5.5 and it also performs loose angle tolerances of 10 and 20° for 1 and 3 dB losses, respectively.
07 Nov 2008
TL;DR: In this paper, a 3D finite-difference time-domain method was used to investigate surface polariton coupling effects between two nano-recording marks which are of different shapes.
Abstract: We use 3-dimensional finite-difference time-domain method to investigate surface polariton coupling effects between two nano-recording marks which are of different shapes. The behavior of near-field optical interactions and their influence on reflected read-out signal will be discussed.
01 Dec 2008
TL;DR: In this paper, a plasmonic liquid-liquid (PLL) waveguide using Au nanoparticles (NPs) colloidal solution is configured on a micro-optical-fluidic system (MOFSOFS) chip.
Abstract: A plasmonic liquid-liquid (PLL) waveguide using Au nano-particles (NPs) colloidal solution is configured on a micro-optical-fluidic system (Mmicro-optical-fluidic system (MOFSOFS) chip for interest extensions of surface plasmon resonance (SPR) assisted measurements For characterizing the PLL waveguide, the propagating modes are studied with the scattering images and the measurement of transmission spectrum Controllability on modes of SPR propagation in PLL waveguide is demonstrated