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1.
Sci Rep ; 9(1): 12774, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31485008

RESUMO

Precipitation is useful information for assessing vital water resources, agriculture, ecosystems and hydrology. Data-driven model predictions using deep learning algorithms are promising for these purposes. Echo state network (ESN) and Deep Echo state network (DeepESN), referred to as Reservoir Computing (RC), are effective and speedy algorithms to process a large amount of data. In this study, we used the ESN and the DeepESN algorithms to analyze the meteorological hourly data from 2002 to 2014 at the Tainan Observatory in the southern Taiwan. The results show that the correlation coefficient by using the DeepESN was better than that by using the ESN and commercial neuronal network algorithms (Back-propagation network (BPN) and support vector regression (SVR), MATLAB, The MathWorks co.), and the accuracy of predicted rainfall by using the DeepESN can be significantly improved compared with those by using ESN, the BPN and the SVR. In sum, the DeepESN is a trustworthy and good method to predict rainfall; it could be applied to global climate forecasts which need high-volume data processing.

2.
Sci Rep ; 9(1): 5134, 2019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30914670

RESUMO

Refractive index sensors based on surface plasmon resonance (SPR) promise to deliver high sensitivities. However, these sensitivities depend on the derivative of the monitored SPR parameters near resonance, so this dependency leads to a relatively narrow detection range for refractive index changes. Herein, we introduce an idea to improve the detection range refractive index through a high-contrast-index curved waveguide surrounded with an outer gold ring. The proposed detection technique, based on the output power measurement of the curved waveguide, offers a linear response over an ultrabroad range of the refractive index for a surrounding medium from n = 1 to 2.36. Meanwhile, an theoretically ultrahigh refractive index resolution (RIU) of 4.53 × 10-10 could be accessible for such a broad testing range, available for both gas and aqueous chemical sample refractive indices Furthermore, the power detection approach enables an integrated photodetector for a lab-on-chip sensor platform, revealing a high potential for a multifunctional, compact, and highly sensitive sensor-on-chip device.

3.
Micromachines (Basel) ; 9(5)2018 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30424159

RESUMO

In this work, we dealt with the optimization of the pulley-type ring resonator using the offset of the straight input and output waveguide at the junction with the curved waveguide. We adopted the finite-difference time-domain method to simulate the structure. It was found that the coupling loss could be significantly reduced and the critical coupling could be precisely tuned. This results in the possibility of the Q-factor being higher than that of the structure without waveguide offset. In this study, the Q-factor of the ring resonator is increased from 9180 to 11,302. The corresponding enhancement is 23.1%.

4.
ACS Appl Mater Interfaces ; 10(46): 39898-39903, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30372020

RESUMO

The desire to improve human lives has led to striking development in biosensing technologies. While the ongoing research efforts are mostly dedicated to enhancing speed and sensitivity of the sensor, a third consideration that has become increasingly important is compactness, which is strongly desired in emergency situations and personal health management. Surface plasmon resonance imaging (SPRi) is one of the few techniques that can potentially fulfill all the three goals, considering its multiplexed assay capability. However, miniaturizing SPRi biosensors remains elusive as it entails complicated optical gears. Here, we significantly slim the architecture of SPRi devices by visualizing the varied local density of states around analytes. The unusual detection scheme is realized by building a gain-assisted SPRi with InGaN quantum wells (QWs), where the QW-plasmon coupling efficiency hinges on localized refractive index variation. This new modality abolishes the prism, the polarizer, and the beam-tracking components in the most used Kretschmann configuration without compromising the performances.

5.
Materials (Basel) ; 10(11)2017 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-29137204

RESUMO

A linear-polarization rotator based on the optically tunable pitch of chiral-azobenzene-doped liquid crystals (CAdLCs) has been investigated. It is shown that the orientation of linearly polarized (LP) light can be optically tuned using CAdLCs and that the transmitted light possesses a good degree of linear polarization (DoLP). Experimental and simulation (4 × 4 Berreman matrix) results show that the rotation angle is dependent on the pitch as well as the number of turns of the cholesteric LC helix. Some causes to affect the DoLP of the output LP lights during photoisomerization are also discussed. Moreover, a calibration term, ß(t), is also introduced to elucidate the behavior of the discontinuous change of the CAdLC pitch in a fixed cell thickness.

6.
Sci Rep ; 6: 22196, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26915332

RESUMO

In this article, the polarization-conversion effects of a gammadion-shaped metasurface in transmission and reflection modes are discussed. In our experiment, the polarization-conversion effect of a gammadion-shaped metasurface is investigated because of the contribution of the phase and amplitude anisotropies. According to our experimental and simulated results, the polarization property of the first-order transmitted diffraction is dominated by linear anisotropy and has weak depolarization; the first-order reflected diffraction exhibits both linear and circular anisotropies and has stronger depolarization than the transmission mode. These results are different from previously published research. The Mueller matrix ellipsometer and polar decomposition method will aid in the investigation of the polarization properties of other nanostructures.

7.
Opt Express ; 24(26): 29963-29971, 2016 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-28059381

RESUMO

Polymer-dispersed liquid crystals (PDLCs) have attracted considerable attention for optical device applications in recent years. However, the high operating voltage of PDLCs limits their applications. This study reports a simple approach used for the first time to decrease the operating voltage of PDLCs by means of doping 3 µm-diameter silver-coated polystyrene microspheres (Ag-coated PSMSs) into PDLCs. Ag-coated PSMSs construct an induced electric field between each other when an external electric field is applied. This induced electric field can enhance the effective electric field so the operating voltage can be actively reduced from 77 V to 40 V. Such PDLCs also possess a high contrast ratio of >50 and a high on-state transmittance of ~73%. Therefore, PDLCs doped with Ag-coated PSMSs maintain a high contrast ratio and improve their electro-optical properties.

8.
Biosens Bioelectron ; 77: 1201-7, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26595485

RESUMO

Evanescent-wave excited fluorescence technology has been demonstrated to enhance sensitivity and reduce matrix effects, making it suitable for biosensor development. In this study, we developed a liposome-based, total internal reflection fluorescence, fiber-optic biosensor (TIRF-FOB) for protein detection, which integrates a liposomal amplifier and sandwich immunoassay format with TIRF-FOB. In addition, the antibody-tagged and fluorophore-entrapped liposomes for heterogeneous detection of target molecules were designed and synthesized. This biosensor successfully detected the target protein (model analyzed here is IgG) with a limit of detection (LOD) of 2.0 attomoles for the target protein (equivalent to 2.0 pg/mL of protein presented in 150 µL of sample solution). The features of this ultra-sensitive liposomal TIRF-FOB are (i) fluorescence is excited via evanescent waves and amplified via liposomes; (ii) the use of two polyclonal antibodies in the sandwich assay format increases the specificity and lowers the cost of our assay. Based on the exceptional detection sensitivity and cost-effectiveness, we believe that the proposed biosensor has great potential as a practical, clinical diagnostic tool in the near future.


Assuntos
Técnicas Biossensoriais/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Imunoglobulina G/análise , Lipossomos/química , Análise Serial de Proteínas/instrumentação , Espectrometria de Fluorescência/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Imunoensaio/instrumentação
9.
Opt Express ; 23(11): 14695-706, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26072828

RESUMO

We present a detailed study of the optically and electrically pumped emission in the BSB-Cz/PVK bilayer waveguide devices. By optical pumping we demonstrate that PVK as a spacer between fluorescent BSB-Cz and ITO electrode allows the significant reduction of the threshold for amplified spontaneous emission (ASE) of BSB-Cz. The simulation provides a better understanding of how the PVK thickness affects the waveguide mode field distribution and hence the ASE threshold of BSB-Cz. On the other hand, the BSB-Cz/PVK bilayer OLED exhibits the external quantum efficiency of >1% and anisotropic electroluminescence with spectrally narrowed edge emission at the cutoff wavelength controlled by the BSB-Cz thickness. When tuning the cutoff wavelength to match the peak gain of BSB-Cz, we demonstrate an intense, particularly narrow edge emission (~5 nm) without obvious degradation of efficiency at a high current density of 1000 mA/cm2, suggesting a reliable device performance for high-power applications and further exploration of electrically-pumped ASE.

10.
Sci Rep ; 5: 10078, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25993265

RESUMO

In this work, we study the performances of ring resonators of different type by analyzing the bending loss and the condition of the critical coupling. We propose that the bending loss of microring can be reduced by wrapping a concentrically curved waveguide. The difference of propagation constant between two concentrically curved waveguides can be tuned by adjusting the bus waveguide width to optimize the critical coupling. Furthermore, we propose to enlarge the difference of the propagation constant between two concentrically curved waveguides to maintain the circulating light in the ring to obtain higher quality factor. In this study, the highest quality factor that we measured is 7 × 10(5).

11.
Opt Express ; 22(19): 22590-7, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25321728

RESUMO

In this work, we optimize the structure of the photonic crystal fibers by using genetic algorithms to provide strong light confinement in fiber and small half diffraction angle of output beam. Furthermore, this article shows the potentials of this study, such as optimizing three purposes at the same time and the arbitrary structure design is achieved. We report two optimized results obtained by different optimization conditions. The results show that the half diffraction angle of the output beam of the photonic crystal fibers can be reduced.


Assuntos
Algoritmos , Técnicas Genéticas/instrumentação , Luz , Desenho de Equipamento , Humanos
12.
Opt Express ; 22 Suppl 6: A1619-33, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25607319

RESUMO

We report a new simple and inexpensive sub-micrometer two dimensional patterning technique. This technique combines a use of a photomask featured with self-organized particles in the micro- to nano-meter size range and a photoresist-covered substrate. The photomask was prepared by depositing monodispersed silicon dioxide (SiO(2))- or polystyrene- spheres on a quartz substrate to form a close-packed pattern. The patterning technique can be realized in two configurations: a hard-contact mode or a soft-contact mode. In the first configuration, each sphere acts as a micro ball-lens that focuses light and exposes the photoresist underneath the sphere. The developed pattern therefore reproduces exactly the same spatial arrangement as the close-packed spheres but with a feature size of developed hole smaller than the diameter of the sphere. In the soft-contact mode, an air gap of few micrometers thick is introduced between the 2D array of self-organized spheres and the photoresist-covered substrate. In this case, a phase mask behavior is obtained which results in an exposure area with a lattice period being half of the sphere diameter. A 2D lattice structure with period and feature size of a developed hole as small as 750 nm and 420 nm, respectively, was realized in this configuration. We further applied this technique to host the deposition of organic films into the 2D nanostructure and demonstrated the realization of green and red nano-structured OLEDs.


Assuntos
Lentes , Iluminação/instrumentação , Nanopartículas/química , Nanopartículas/ultraestrutura , Semicondutores , Dióxido de Silício/química , Cristalização/métodos , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Miniaturização , Compostos Orgânicos/química , Fotografação/métodos , Impressão Tridimensional , Propriedades de Superfície
13.
Opt Express ; 21(8): 9947-58, 2013 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-23609700

RESUMO

In this article, we propose an optical heterodyne common-path gyroscope which has common-path configuration and full-dynamic range. Different from traditional non-common-path optical heterodyne technique such as Mach-Zehnder or Michelson interferometers, we use a two-frequency laser light source (TFLS) which can generate two orthogonally polarized light with a beat frequency has a common-path configuration. By use of phase measurement, this optical heterodyne gyroscope not only has the capability to overcome the drawback of the traditional interferometric fiber optic gyro: lack for full-dynamic range, but also eliminate the total polarization rotation caused by SMFs. Moreover, we also demonstrate the potential of miniaturizing this gyroscope as a chip device. Theoretically, if we assume that the wavelength of the laser light is 1550nm, the SMFs are 250m in length, and the radius of the fiber ring is 3.5cm, the bias stability is 0.872 deg/hr.


Assuntos
Aceleração , Interferometria/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento
14.
Opt Express ; 19(12): 11890-6, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21716422

RESUMO

The attenuator for the wavelength at 1550 nm is fabricated by using the capillary effect to infiltrate liquid crystal (LC) E7 into hollow waveguides (HWGs) on silicon substrate with SiO2 cladding layer. The length of the waveguide is 0.4 cm. The device can be operated with relatively low driving voltage below 5 V(pp) with the distance between two electrodes to be 9 µm. The light attenuation of the device can be over 30 dB. The performance of the device is independent of the polarization states of the input light.

15.
Appl Opt ; 50(2): 227-30, 2011 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-21221149

RESUMO

In this paper, we describe a theoretical and experimental study of a wavelength-selective filter derived from hollow optical waveguides composed of Bragg reflectors with defect layers on a silicon substrate. The defect states of the transmission filter at wavelengths of 1519 and 1571 nm were realized using one-dimensional photonic crystals (1D PCs) formed from a-Si and SiO(2). The transmission spectra of the filter waveguides and the band structure of the defect 1D PCs were calculated using the two-dimensional finite-difference time-domain and transfer matrix methods, respectively. The device exhibited the narrow bandwidths of 0.5 and 1.1 nm for wavelengths of 1571 and 1519 nm, respectively.

16.
Anal Chem ; 82(14): 5944-50, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20557064

RESUMO

The development of rapid and sensitive methods for the detection of immunogenic tumor-associated antigen is important not only for understanding their roles in cancer immunology but also for the development of clinical diagnostics. Alpha-enolase (ENO1), a p48 molecule, is widely distributed in a variety of tissues, whereas gamma-enolase (ENO2) and beta-enolase (ENO3) are found exclusively in neuron/neuroendocrine and muscle tissues, respectively. Because ENO1 has been correlated with small cell lung cancer, nonsmall cell lung cancer, and head and neck cancer, it can be used as a potential diagnostic marker for lung cancer. In this study, we developed a simple, yet novel and sensitive, electrochemical sandwich immunosensor for the detection of ENO1; it operates through physisorption of anti-ENO1 monoclonal antibody on polyethylene glycol-modified disposable screen-printed electrode as the detection platform, with polyclonal secondary anti-ENO1-tagged, gold nanoparticle (AuNP) congregates as electrochemical signal probes. The immunorecognition of the sample ENO1 by the congregated AuNP@antibody occurred on the surface of the electrodes; the electrochemical signal from the bound AuNP congregates was obtained after oxidizing them in 0.1 M HCl at 1.2 V for 120 s, followed by the reduction of AuCl(4-) in square wave voltammetry (SWV) mode. The resulting sigmoidally shaped dose-response curves possessed a linear dynamic working range from 10(-8) to 10(-12) g/mL. This AuNP congregate-based assay provides an amplification approach for detecting ENO1 at trace levels, leading to a detection limit as low as 11.9 fg (equivalent to 5 microL of a 2.38 pg/mL solution).


Assuntos
Antígenos de Neoplasias/análise , Técnicas Eletroquímicas/métodos , Ouro/química , Neoplasias Pulmonares/diagnóstico , Nanopartículas Metálicas/química , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Antígenos de Neoplasias/imunologia , Técnicas Biossensoriais/métodos , Eletrodos , Humanos , Fosfopiruvato Hidratase/análise , Fosfopiruvato Hidratase/imunologia , Polietilenoglicóis/química
17.
Biosens Bioelectron ; 25(2): 320-5, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19660929

RESUMO

In order to enhance the sensitivity of conventional immunoassay technology for the detection of SARS coronavirus (SARS-CoV) nucleocapsid protein (N protein), we developed a localized surface plasmon coupled fluorescence (LSPCF) fiber-optic biosensor that combines sandwich immunoassay with the LSP technique. Experimentally, a linear relationship between the fluorescence signal and the concentration of recombinant SARS-CoV N (GST-N) protein in buffer solution could be observed from 0.1 pg/mL to 1 ng/mL. In addition, the concentration of GST-N protein in diluted serum across a similar range could also be measured. The correlation coefficients (linear scale) for these two measurements were 0.9469 and 0.9624, respectively. In comparison with conventional enzyme linked immunosorbent assay (ELISA), the detection limit of the LSPCF fiber-optic biosensor for the GST-N protein was improved at least 10(4)-fold using the same monoclonal antibodies. Therefore, the LSPCF fiber-optic biosensor shows an ability to detect very low concentration (approximately 1 pg/mL) of SARS-CoV N protein in serum. The biosensor should help with the early diagnosis of SARS infection.


Assuntos
Técnicas Biossensoriais/instrumentação , Análise Química do Sangue/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Proteínas do Nucleocapsídeo/sangue , Vírus da SARS/metabolismo , Espectrometria de Fluorescência/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos
18.
Opt Express ; 17(8): 6519-24, 2009 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-19365476

RESUMO

In this study we develop an efficient light harvesting scheme that can enhance the efficiency of GaAs solar cells using self-assembled microspheres. Based on the scattering of the microspheres and the theory of photonic crystals, the path length can be increased. In addition, the self-assembly of microspheres is one of the simplest and the fastest methods with which to build a 2D periodic structure. The experimental results are confirmed by the use of a simulation in which a finite-difference time-domain (FDTD) method is used to analyze the absorption and electric field of the 2D periodic structure. Both the results of the numerical simulations and the experimental results show an increase in the conversion power efficiency of GaAs solar cell of about 25% when 1 microm microspheres were assembled on the surface of GaAs solar cells.


Assuntos
Arsenicais/química , Fontes de Energia Elétrica , Gálio/química , Refratometria/instrumentação , Energia Solar , Arsenicais/efeitos da radiação , Desenho Assistido por Computador , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Gálio/efeitos da radiação , Luz , Microesferas , Refratometria/métodos , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade
19.
Inorg Chem ; 48(4): 1519-23, 2009 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-19159316

RESUMO

Four isostructural organically templated lanthanide oxalatophosphates, (H(4)APPIP)[Ln(3)(C(2)O(4))(5.5)(H(2)PO(4))(2)].5H(2)O (Ln = Er-Lu and APPIP = 1,4-bis(3-aminopropyl)piperazine), have been synthesized under hydrothermal conditions and characterized by single-crystal and powder X-ray diffraction. Their structures contain LnO(8) trigonal dodecahedra linked by three bis-bidentate oxalates to form layers in the (102) plane, which are connected by dihydrogen phosphate and bis-monodentate oxalate ligands to form a 3D framework. The charge-compensating tetraprotonated 1,4-bis(3-aminopropyl)piperazinium cations and lattice water molecules are located in the 12-membered ring straight channels. They are the first examples of organically templated lanthanide oxalatophosphates. The thermal stability, guest desorption-sorption properties, variable-temperature in situ powder X-ray diffraction, magnetic susceptibility, and photoluminescence spectrum of the Er compound and catalytic activity of the Yb compound for the Biginelli reaction have also been studied.

20.
Opt Express ; 16(19): 15069-73, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18795044

RESUMO

In this study, a hollow bent waveguide with distributed Bragg reflectors (DBR) in silicon substrate was presented theoretically and experimentally. We used the two-dimensional finite-difference time-domain method to simulate bending transmission efficiencies for arc- and cut-type 90 degrees -bent waveguides. The air core was embedded by Si(3)N(4)/SiO(2) multilayer. The multilayer stacks were deposited by using plasma-enhanced chemical vapor deposition on the top and bottom of air core. The lowest 90 degree bending loss is around 3.9dB for the arc-type bending waveguides and 0.8dB for cut-type bending waveguides, respectively. This waveguide demonstrates a possibility for higher density of integration in planar light wave circuits.


Assuntos
Desenho Assistido por Computador , Modelos Teóricos , Óptica e Fotônica/instrumentação , Refratometria/instrumentação , Silício/química , Simulação por Computador , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização
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