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Sample records for based optically transparent

  1. An innovative transparent cranial window based on skull optical clearing An innovative transparent cranial window

    Science.gov (United States)

    Wang, J.; Zhang, Y.; Xu, T. H.; Luo, Q. M.; Zhu, D.

    2012-06-01

    Noninvasive optical methods for viewing the structural and functional organization of cortex have been playing important roles in brain research, which usually suffer from turbid skull. Various cranial window models based on surgical operation have been proposed, but have respective limitations. Here, an innovative transparent cranial window of mouse was established by topically treatment with a skull optical clearing solution (SOCS), rather than by craniotomy. Based on the experiment of optical clearing efficacy of skull in vitro, we found that the turbid skull became transparent within 25 min after application of SOCS. The USAF target is visible through the treated skull, and the calculated resolution can achieve 8.4 μm. After the in vivo skull was topically treated with SOCS, the cortical micro-vessels can be visible clearly. The quantitative analysis indicated that the minimum resolution diameter of micro-vessels in 14.4±0.8 μm through the transparent cranial window closed to that in 12.8±0.9 μm of the exposed cortical micro-vessels. Further, preliminary results from Laser Speckle Imaging demonstrated that there was no influence on cortical blood flow distribution of mouse after topically treatment with SOCS on skull. This transparent cranial window will provide a convenient model for cortex imaging in vivo, which is very significant for neuroscience research.

  2. Reconfigurable optical routers based on Coupled Resonator Induced Transparency resonances.

    Science.gov (United States)

    Mancinelli, M; Bettotti, P; Fedeli, J M; Pavesi, L

    2012-10-08

    The interferometric coupling of pairs of resonators in a resonator sequence generates coupled ring induced transparency (CRIT) resonances. These have quality factors an order of magnitude greater than those of single resonators. We show that it is possible to engineer CRIT resonances in tapered SCISSOR (Side Coupled Integrated Space Sequence of Resonator) to realize fast and efficient reconfigurable optical switches and routers handling several channels while keeping single channel addressing capabilities. Tapered SCISSORs are fabricated in silicon-on-insulator technology. Furthermore, tapered SCISSORs show multiple-channel switching behavior that can be exploited in DWDM applications.

  3. Optical quantum memory based on electromagnetically induced transparency.

    Science.gov (United States)

    Ma, Lijun; Slattery, Oliver; Tang, Xiao

    2017-04-01

    Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.

  4. Water-based metamaterial absorbers for optical transparency and broadband microwave absorption

    Science.gov (United States)

    Pang, Yongqiang; Shen, Yang; Li, Yongfeng; Wang, Jiafu; Xu, Zhuo; Qu, Shaobo

    2018-04-01

    Naturally occurring water is a promising candidate for achieving broadband absorption. In this work, by virtue of the optically transparent character of the water, the water-based metamaterial absorbers (MAs) are proposed to achieve the broadband absorption at microwave frequencies and optical transparence simultaneously. For this purpose, the transparent indium tin oxide (ITO) and polymethyl methacrylate (PMMA) are chosen as the constitutive materials. The water is encapsulated between the ITO backed plate and PMMA, serving as the microwave loss as well as optically transparent material. Numerical simulations show that the broadband absorption with the efficiency over 90% in the frequency band of 6.4-30 GHz and highly optical transparency of about 85% in the visible region can be achieved and have been well demonstrated experimentally. Additionally, the proposed water-based MA displays a wide-angle absorption performance for both TE and TM waves and is also robust to the variations of the structure parameters, which is much desired in a practical application.

  5. Properties of Siloxane Based Optical Waveguides Deposited on Transparent Paper and Foil

    Directory of Open Access Journals (Sweden)

    V. Prajzler

    2016-06-01

    Full Text Available In this paper, we present the properties of flexible planar optical waveguides made of siloxane-based polymer deposited on Xerox transparent paper and PLEXIGLAS foil substrate. Measurement of optical properties such as the waveguiding properties and refractive index is carried out by the prism coupling technique for five wavelengths (473, 632.8, 964, 1311 and 1552 nm and propagation optical loss were measured by the fibre probe technique at a wavelength of 632.8 nm (He-Ne laser. The measurement proved waveguiding properties for all measured wavelengths and the losses generally did not exceed 0.40 dB/cm; the best samples had optical losses around 0.24 dB/cm.

  6. Optical properties of graphene-based materials in transparent polymer matrices

    Energy Technology Data Exchange (ETDEWEB)

    Bayrak, Osman; Demirci, Emrah, E-mail: E.Demirci@lboro.ac.uk; Silberschmidt, Vadim V. [Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Ionita, Mariana [Advanced Polymer Materials Group, University Politehnica of Bucharest, 132 Calea Grivitei, 010737 Bucharest (Romania)

    2016-08-22

    Different aspects of graphene-based materials (GBMs) and GBM-nanocomposites have been investigated due to their intriguing features; one of these features is their transparency. Transparency of GBMs has been of an interest to scientists and engineers mainly with regard to electronic devices. In this study, optical transmittance of structural, purpose-made nanocomposites reinforced with GBMs was analyzed to lay a foundation for optical microstructural characterization of nanocomposites in future studies. Two main types of GBM reinforcements were studied, graphene oxide (GO) and graphite nanoplates (GNPs). The nanocomposites investigated are GO/poly(vinyl alcohol), GO/sodium alginate, and GNP/epoxy with different volume fractions of GBMs. Together with UV-visible spectrophotometry, image-processing-assisted micro and macro photography were used to assess the transparency of GBMs embedded in the matrices. The micro and macro photography methods developed were proven to be an alternative way of measuring light transmittance of semi-transparent materials. It was found that there existed a linear relationship between light absorbance and a volume fraction of GBMs embedded in the same type of polymer matrices, provided that the nanocomposites of interest had the same thicknesses. This suggests that the GBM dispersion characteristics in the same type of polymer are similar and any possible change in crystal structure of polymer due to different volumetric contents of GBM does not have an effect on light transmittance of the matrices. The study also showed that the same types of GBMs could display different optical properties in different matrix materials. The results of this study will help to develop practical microstructural characterization techniques for GBM-based nanocomposites.

  7. Bit-rate-transparent optical RZ-to-NRZ format conversion based on linear spectral phase filtering

    DEFF Research Database (Denmark)

    Maram, Reza; Da Ros, Francesco; Guan, Pengyu

    2017-01-01

    We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal.......We propose a novel and strikingly simple design for all-optical bit-rate-transparent RZ-to-NRZ conversion based on optical phase filtering. The proposed concept is experimentally validated through format conversion of a 640 Gbit/s coherent RZ signal to NRZ signal....

  8. Optical properties of photodetectors based on single GaN nanowires with a transparent graphene contact

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, A. V., E-mail: A.Babichev@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Institute (Russian Federation); Zhang, H.; Guan, N. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France); Egorov, A. Yu. [ITMO University (Russian Federation); Julien, F. H.; Messanvi, A. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France); Durand, C.; Eymery, J. [University Grenoble Alpes (France); Tchernycheva, M. [University Paris Saclay, Institut d’Electronique Fondamentale, UMR 8622 CNRS (France)

    2016-08-15

    We report the fabrication and optical and electrical characterization of photodetectors for the UV spectral range based on single p–n junction nanowires with a transparent contact of a new type. The contact is based on CVD-grown (chemical-vapor deposition) graphene. The active region of the nitride nanowires contains a set of 30 radial In{sub 0.18}Ga{sub 0.82}N/GaN quantum wells. The structure is grown by metal-organic vaporphase epitaxy. The photodetectors are fabricated using electron-beam lithography. The current–voltage characteristics exhibit a rectifying behavior. The spectral sensitivity of the photodetector is recorded starting from 3 eV and extending far in the UV range. The maximal photoresponse is observed at a wavelength of 367 nm (sensitivity 1.9 mA/W). The response switching time of the photodetector is less than 0.1 s.

  9. Data Transparent and Polarization Insensitive All-Optical Switch based on Fibers with Enhanced Nonlinearity

    Directory of Open Access Journals (Sweden)

    M. Komanec

    2014-09-01

    Full Text Available We have developed a data transparent optical packet switch prototype employing wavelength conversion based on four-wave mixing. The switch is composed of an electro-optical control unit and an all-optical switching segment. To achieve higher switching efficiencies, Ge-doped silica suspended-core and chalcogenide arsenicselenide single-mode fibers were experimentally evaluated and compared to conventional highly-nonlinear fiber. Improved connectorization technology has been developed for Ge-doped suspended-core fiber, where we achieved connection losses of 0.9 dB. For the arsenic-selenide fiber we present a novel solid joint technology, with connection losses of only 0.25 dB, which is the lowest value presented up-to-date. Conversion efficiency of -13.7 dB was obtained for the highly-nonlinear fiber, which is in perfect correlation with previously published results and thus verifies the functionality of the prototype. Conversion efficiency of -16.1 dB was obtained with arsenic-selenide fiber length reduced to five meters within simulations, based on measurement results with a 26 m long component. Employment of such a short arsenic-selenide fiber segment allows significant broadening of the wavelength conversion spectral range due to possible neglection of dispersion.

  10. Optically transparent semiconducting polymer nanonetwork for flexible and transparent electronics

    Science.gov (United States)

    Yu, Kilho; Park, Byoungwook; Kim, Geunjin; Kim, Chang-Hyun; Park, Sungjun; Kim, Jehan; Jung, Suhyun; Jeong, Soyeong; Kwon, Sooncheol; Kang, Hongkyu; Kim, Junghwan; Yoon, Myung-Han; Lee, Kwanghee

    2016-01-01

    Simultaneously achieving high optical transparency and excellent charge mobility in semiconducting polymers has presented a challenge for the application of these materials in future “flexible” and “transparent” electronics (FTEs). Here, by blending only a small amount (∼15 wt %) of a diketopyrrolopyrrole-based semiconducting polymer (DPP2T) into an inert polystyrene (PS) matrix, we introduce a polymer blend system that demonstrates both high field-effect transistor (FET) mobility and excellent optical transparency that approaches 100%. We discover that in a PS matrix, DPP2T forms a web-like, continuously connected nanonetwork that spreads throughout the thin film and provides highly efficient 2D charge pathways through extended intrachain conjugation. The remarkable physical properties achieved using our approach enable us to develop prototype high-performance FTE devices, including colorless all-polymer FET arrays and fully transparent FET-integrated polymer light-emitting diodes. PMID:27911774

  11. Optically transparent and environmentally durable superhydrophobic coating based on functionalized SiO2 nanoparticles

    Science.gov (United States)

    Schaeffer, Daniel A.; Polizos, Georgios; Barton Smith, D.; Lee, Dominic F.; Hunter, Scott R.; Datskos, Panos G.

    2015-02-01

    Optical surfaces such as mirrors and windows that are exposed to outdoor environmental conditions are susceptible to dust buildup and water condensation. The application of transparent superhydrophobic coatings on optical surfaces can improve outdoor performance via a ‘self-cleaning’ effect similar to the Lotus effect. The contact angle (CA) of water droplets on a typical hydrophobic flat surface varies from 100° to 120°. Adding roughness or microtexture to a hydrophobic surface leads to an enhancement of hydrophobicity and the CA can be increased to a value in the range of 160°-175°. This result is remarkable because such behavior cannot be explained using surface chemistry alone. When surface features are on the order of 100 nm or smaller, they exhibit superhydrophobic behavior and maintain their optical transparency. In this work we discuss our results on transparent superhydrophobic coatings that can be applied across large surface areas. We have used functionalized silica nanoparticles to coat various optical elements and have measured the CA and optical transmission between 190 and 1100 nm on these elements. The functionalized silica nanoparticles were dissolved in a solution of the solvents, while the binder used was a polyurethane clearcoat. This solution was spin-coated onto a variety of test glass substrates, and following a curing period of about 30 min, these coatings exhibited superhydrophobic behavior with a static CA ≥ 160°.

  12. Optically transparent and environmentally durable superhydrophobic coating based on functionalized SiO₂ nanoparticles.

    Science.gov (United States)

    Schaeffer, Daniel A; Polizos, Georgios; Smith, D Barton; Lee, Dominic F; Hunter, Scott R; Datskos, Panos G

    2015-02-06

    Optical surfaces such as mirrors and windows that are exposed to outdoor environmental conditions are susceptible to dust buildup and water condensation. The application of transparent superhydrophobic coatings on optical surfaces can improve outdoor performance via a 'self-cleaning' effect similar to the Lotus effect. The contact angle (CA) of water droplets on a typical hydrophobic flat surface varies from 100° to 120°. Adding roughness or microtexture to a hydrophobic surface leads to an enhancement of hydrophobicity and the CA can be increased to a value in the range of 160°-175°. This result is remarkable because such behavior cannot be explained using surface chemistry alone. When surface features are on the order of 100 nm or smaller, they exhibit superhydrophobic behavior and maintain their optical transparency. In this work we discuss our results on transparent superhydrophobic coatings that can be applied across large surface areas. We have used functionalized silica nanoparticles to coat various optical elements and have measured the CA and optical transmission between 190 and 1100 nm on these elements. The functionalized silica nanoparticles were dissolved in a solution of the solvents, while the binder used was a polyurethane clearcoat. This solution was spin-coated onto a variety of test glass substrates, and following a curing period of about 30 min, these coatings exhibited superhydrophobic behavior with a static CA ≥ 160°.

  13. Optical thermometry based on luminescence behavior of Dy{sup 3+}-doped transparent LaF{sub 3} glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Y.Y. [Nanjing University of Posts and Telecommunications, College of Electronic Science and Engineering, Nanjing (China); Nanjing University of Posts and Telecommunications, College of Science, Nanjing (China); Cheng, S.J.; Wang, X.F. [Nanjing University of Posts and Telecommunications, College of Electronic Science and Engineering, Nanjing (China); Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing, Jiangsu (China); Yan, X.H. [Nanjing University of Posts and Telecommunications, College of Electronic Science and Engineering, Nanjing (China); Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Science, Nanjing (China)

    2015-11-15

    Dy{sup 3+}-doped transparent LaF{sub 3} glass ceramics were fabricated, and its structures of resulting glass ceramics are studied by the X-ray diffraction and transmission electron microscopy. Optical temperature sensing of the resulting glass ceramics in the temperature range from 298 to 523 K is studied based on the down-conversion luminescence of Dy{sup 3+} ion. By using fluorescence intensity ratio method, the {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} of Dy{sup 3+} ions are verified as thermally coupled levels. A minimum S{sub R} = 1.16 x 10{sup -4} K{sup -1} is obtained at T = 294 K. By doping Eu{sup 3+} ion, the overall emission color of Eu{sup 3+}-Dy{sup 3+} co-doped transparent glass ceramics can be tuned from white to yellow with the temperature increase through energy transfer between Eu{sup 3+} and Dy{sup 3+}. Additionally, the thermal stability of the Dy{sup 3+} single-doped transparent glass ceramics becomes higher after doping Eu{sup 3+} ion. (orig.)

  14. Optically Transparent Nanoporous Glasspolymer Composites

    National Research Council Canada - National Science Library

    O'Brien, D. J; Juliano, T. F; Patel, P. J; McKnight, S. H

    2006-01-01

    .... This transparent nanocomposite is created by infiltrating nanoporous glass (Vycor, Corning Inc.) with different polymers. The Vycor pores (4-6 nm) are much smaller than the wavelength of light, thus refractive index matching with the polymer is not necessary for transparency.

  15. Printed optically transparent graphene cellulose electrodes

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

    2016-02-01

    Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

  16. Subnanometer-accuracy optical distance ruler based on fluorescence quenching by transparent conductors

    NARCIS (Netherlands)

    Moerland, R.J.; Hoogenboom, J.P.

    2016-01-01

    Available data: Complex refractive index of Indium Tin Oxide, http://dx.doi.org/10.4121/uuid:59febf27-a532-4ac9-8ec0-29d4195b2c8c Transparent conductive oxides (TCOs), such as the well-known indium-tin oxide, find widespread use in modern (nano)technological applications because of their unique

  17. Electromagnetically induced transparency in optical microcavities

    Directory of Open Access Journals (Sweden)

    Liu Yong-Chun

    2017-03-01

    Full Text Available Electromagnetically induced transparency (EIT is a quantum interference effect arising from different transition pathways of optical fields. Within the transparency window, both absorption and dispersion properties strongly change, which results in extensive applications such as slow light and optical storage. Due to the ultrahigh quality factors, massive production on a chip and convenient all-optical control, optical microcavities provide an ideal platform for realizing EIT. Here we review the principle and recent development of EIT in optical microcavities. We focus on the following three situations. First, for a coupled-cavity system, all-optical EIT appears when the optical modes in different cavities couple to each other. Second, in a single microcavity, all-optical EIT is created when interference happens between two optical modes. Moreover, the mechanical oscillation of the microcavity leads to optomechanically induced transparency. Then the applications of EIT effect in microcavity systems are discussed, including light delay and storage, sensing, and field enhancement. A summary is then given in the final part of the paper.

  18. Optically-transparent radiation-shielding composition

    International Nuclear Information System (INIS)

    Bolles, T.F.; Fleming, P.B.

    1976-01-01

    An optically transparent, essentially colorless radiation shielding material for high energy radiation contains a combination of lead or thallium salts of C 1 to C 5 organic acids and may contain lead or thallium salts of mineral acids. Shields of complex shapes are easily constructed

  19. Electro-optic transparent frequency conversion of a continuous light wave based on multistage phase modulation.

    Science.gov (United States)

    Hisatake, Shintaro; Kobayashi, Tetsuro

    2006-02-15

    Frequency conversion of a continuous light wave based on multistage phase modulation has been investigated both analytically and numerically. The proposed frequency-conversion process consists of three stages: (i) phase modulation and chirp compression to generate a pulse train, (ii) Doppler shift of the pulse center frequency in a second phase modulation, and (iii) demodulation of the pulse train. By controlling the modulation power we can select the destination frequency from an equally spaced grid separated by the modulation frequency. A conversion efficiency of approximately 40% has been numerically confirmed with respect to a destination frequency of +/- 50 channels. Carrier frequency conversion of an analog data stream is numerically demonstrated.

  20. Electrical and optical study of transparent V-based oxide semiconductors prepared by magnetron sputtering under different conditions

    Directory of Open Access Journals (Sweden)

    E. Prociow

    2011-04-01

    Full Text Available This work is focused on structural, optical and electrical behaviors of vanadium-based oxide thin films prepared by magnetron sputtering under different conditions. Thin films have been deposited on glass substrates from metallic vanadium target at low sputtering pressure. Different working gases: argon/oxygen mixture, and especially pure oxygen gas, have been applied. Results of X-ray diffraction together with optical transmission and temperature- dependent electrical resistivity measurements have been presented. Transmission coefficient, cut-off wavelength and the width of the optical band gap have been calculated from optical measurements. The d.c. resistivity values at room temperature and thermal activation energy have been obtained from electrical investigations. The influence of sputtering process conditions on optical and electrical properties has been discussed.

  1. Physical impairment aware transparent optical networks

    Science.gov (United States)

    Antona, Jean-Christophe; Morea, Annalisa; Zami, Thierry; Leplingard, Florence

    2009-11-01

    As illustrated by optical fiber and optical amplification, optical telecommunications have appeared for the last ten years as one of the most promising candidates to increase the transmission capacities. More recently, the concept of optical transparency has been investigated and introduced: it consists of the optical routing of Wavelength Division Multiplexed (WDM) channels without systematic optoelectronic processing at nodes, as long as propagation impairments remain acceptable [1]. This allows achieving less power-consuming, more scalable and flexible networks, and today partial optical transparency has become a reality in deployed systems. However, because of the evolution of traffic features, optical networks are facing new challenges such as demand for higher transmitted capacity, further upgradeability, and more automation. Making all these evolutions compliant on the same current network infrastructure with a minimum of upgrades is one of the main issues for equipment vendors and operators. Hence, an automatic and efficient management of the network needs a control plan aware of the expected Quality of Transmission (QoT) of the connections to set-up with respect to numerous parameters such as: the services demanded by the customers in terms of protection/restoration; the modulation rate and format of the connection under test and also of its adjacent WDM channels; the engineering rules of the network elements traversed with an accurate knowledge of the associated physical impairments. Whatever the method and/or the technology used to collect this information, the issue about its accuracy is one of the main concerns of the network system vendors, because an inaccurate knowledge could yield a sub-optimal dimensioning and so additional costs when installing the network in the field. Previous studies [1], [2] illustrated the impact of this knowledge accuracy on the ability to predict the connection feasibility. After describing usual methods to build

  2. Optical cavity-assisted broadband optical transparency of a plasmonic metal film

    International Nuclear Information System (INIS)

    Liu, Zhengqi; Nie, Yiyou; Yuan, Wen; Liu, Xiaoshan; Huang, Shan; Gao, Huogui; Gu, Gang; Liu, Guiqiang; Chen, Jing

    2015-01-01

    We theoretically present a powerful method to achieve a continuous metal film structure with broadband optical transparency via introducing a dielectric Fabry–Pérot (FP) cavity. An incident optical field could be efficiently coupled and confined with the strong localized plasmons by the non-close-packed plasmonic crystal at the input part and could then become re-radiated output via the transmission channel supported by the dielectric cavity. The formed photonic-plasmonic system could therefore make the seamless metal film structure have a superior near-unity transparency (up to 97%) response and a broadband transparent spectrum with bandwidth >245 nm (with transmittance >90%) in the optical regime. The observed optical properties of the proposed structure can be highly tuned via varying the structural parameters. Based on the colloidal assembly method, the proposed plasmonic crystal can be fabricated in a large area. In addition, the achieved optical transparency can be retained in the extremely roughed metal film structure. Thereby, the findings could offer a feasible way to achieve a broadband transparent metal film structure and hold potential applications in transparent electrodes, touch screens and interactive electronics. (paper)

  3. Multichannel packets buffering in cascaded double-loop optical buffer based on the pure phase switching of gain-transparent semiconductor optical amplifier

    Science.gov (United States)

    Yongjun, Wang; Xiangjun, Xin; Chao, Shang

    2014-01-01

    An innovative cascaded double-loop optical buffer (DLOB) with a large dynamic variable delay suitable for buffering multichannel data packets is proposed and demonstrated. In this buffer, the pure phase modulation of the gain-transparent semiconductor optical amplifier (GT-SOA) is used as the optical switching, and then an experimental system with two buffering units is established. The data packets carried out on four different wavelengths have been stored for 12 round trips successively in DLOB1 and DLOB2, and a long delay time of 39.6 μs has been achieved. The pulse distortion, pattern effect, and channel crosstalk caused by the SOA's nonlinear gain, carrier recovery time, cross-phase modulation, and cross-gain modulation have been eliminated clearly, and the accumulation of ASE noise has also been effectively mitigated. The signal details, the eye diagrams, and the bit error ratio curves for all four wavelengths show that the proposed optical buffer is an effective approach for buffering multichannel data packets, especially when the GT-SOA's transmission loss decreases in the near future.

  4. Direct milling and casting of polymer-based optical waveguides for improved transparency in the visible range

    DEFF Research Database (Denmark)

    Snakenborg, Detlef; Perozziello, Gerardo; Klank, Henning

    2006-01-01

    with integrated optical waveguides. Polymethylinethacrylate (PMMA) is dissolved in anisole and 'doped' with styrene-arcylonitrile copolymer to vary the refractive index. The doped PMMA with a higher refractive index is then spin coated onto a PMMA substrate with a lower refractive index to provide waveguide...

  5. Fabrication and characterization of cellulose nanocrystal based transparent electroactive polyurethane

    Science.gov (United States)

    Ko, Hyun-U.; Kim, Hyun Chan; Kim, Jung Woong; Zhai, Lindong; Jayaramudu, Tippabattini; Kim, Jaehwan

    2017-08-01

    This paper reports cellulose nanocrystal (CNC) based transparent and electroactive polyurethane (CPPU), suitable for actively tunable optical lens. CNC is used for high dielectric filler to improve electromechanical behavior of CPPU. For high transparency and homogeneous distribution of CNC in polyurethane, CNC-poly[di(ethylene glycol) adipate] is used to play a role of polyol and isocyanate salt. The fabricated CPPU exhibits high transparency (>90%) and 10% of electromechanical strain under 3 V μm-1 electric field. Mechanical, dielectric properties as well as physical and chemical characteristics are investigated to prove the electromechanical behavior of CPPU.

  6. High Fidelity Additive Manufacturing of Optically Transparent Glass Structures

    Science.gov (United States)

    Inamura, Chikara

    Glass has been an integral part of human civilization with expressions across scales and disciplines: from the microscope to the telescope, from fiber optics to mobile interface, and from the petri dish to a building envelope. Such a diverse range of applications is enabled by the inherent material properties including mechanical strength, optical transparency and chemical inertness. Additive manufacturing provides opportunities for integrating the unique properties of glass to engineer novel structures that are functionary graded through precise spatiotemporal deposition of molten glass. This talk presents the Mediated Matter Group's latest development of a novel additive manufacturing platform, and related processes, for 3D Printing optically transparent glass for architectural scale applications.

  7. National Transparent Optical Network Consortium (NTONC)

    National Research Council Canada - National Science Library

    Daspit, Paul

    2004-01-01

    ... (DWDM) transport, switching technologies and control strategies required to develop, deploy and operate the terabit per second optical networks needed to meet requirements of Next Generation Internet applications...

  8. Highly linear and transparent 3-18 GHz optical microwave link

    DEFF Research Database (Denmark)

    Nielsen, Torben Nørskov; Gliese, Ulrik Bo; Christensen, T.

    1994-01-01

    A highly linear optical microwave link transmitter based on heterodyne phase-locked DFB lasers is presented. The transmitter is transparent for FM and PM input signals with carrier frequencies ranging from 3-18 GHz. Distortion-free transmission of a 7.6 GHz FM PAL video signal over 25 km of optical...

  9. Fabrication of optically transparent chitin nanocomposites

    Science.gov (United States)

    Shams, M. Iftekhar; Ifuku, Shinsuke; Nogi, Masaya; Oku, Takeshi; Yano, Hiroyuki

    2011-02-01

    This paper demonstrates the preparation of chitin nanofibers from crab shells using a simple mechanical treatment. The nanofibers are small enough to retain the transparency of neat acrylic resin. Possessing hydroxyl and amine/ N-acetyl functionalities, water suspension of chitin nanofibers was vacuum-filtered 9 times faster than cellulose nanofibers to prepare a nanofiber sheet of 90 mm in diameter. This is a prominent advantage of chitin nanofibers over cellulose nanofibers in terms of commercial application. Interestingly, chitin acrylic resin films exhibited much higher transparency than cellulose acrylic resin films owing to the close affinity between less hydrophilic chitin and hydrophobic resin. Furthermore, the incorporation of chitin nanofibers contributes to the significant improvement of the thermal expansion and mechanical properties of the neat acrylic resin. The properties of high light transmittance and low thermal expansion make chitin nanocomposites promising candidates for the substrate in a continuous roll-to-roll process in the manufacturing of various optoelectronic devices such as flat panel displays, bendable displays, and solar cells.

  10. Optically transparent, scratch-resistant, diamond-like carbon coatings

    Science.gov (United States)

    He, Xiao-Ming; Lee, Deok-Hyung; Nastasi, Michael A.; Walter, Kevin C.; Tuszewski, Michel G.

    2003-06-03

    A plasma-based method for the deposition of diamond-like carbon (DLC) coatings is described. The process uses a radio-frequency inductively coupled discharge to generate a plasma at relatively low gas pressures. The deposition process is environmentally friendly and scaleable to large areas, and components that have geometrically complicated surfaces can be processed. The method has been used to deposit adherent 100-400 nm thick DLC coatings on metals, glass, and polymers. These coatings are between three and four times harder than steel and are therefore scratch resistant, and transparent to visible light. Boron and silicon doping of the DLC coatings have produced coatings having improved optical properties and lower coating stress levels, but with slightly lower hardness.

  11. Optically transparent composite diamond/Ti electrodes

    Czech Academy of Sciences Publication Activity Database

    Ashcheulov, Petr; Taylor, Andrew; More Chevalier, Joris; Kovalenko, A.; Remeš, Zdeněk; Drahokoupil, Jan; Hubík, Pavel; Fekete, Ladislav; Klimša, Ladislav; Kopeček, Jaromír; Remiášová, Jarmila; Kohout, Michal; Frank, Otakar; Kavan, Ladislav; Mortet, Vincent

    2017-01-01

    Roč. 119, Aug (2017), s. 179-189 ISSN 0008-6223 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA13-31783S Grant - others:FUNBIO(XE) CZ.2.16/3.1.00/21568; AV ČR(CZ) Fellowship J. E. Purkyně; AV ČR(CZ) MSM100101602 Program:Program na podporu mezinárodní spolupráce začínajících výzkumných pracovníků Institutional support: RVO:68378271 ; RVO:61388955 Keywords : diamond * transparent film * composite electrode * conductive thin film Subject RIV: BM - Solid Matter Physics ; Magnetism; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Physical chemistry (UFCH-W) Impact factor: 6.337, year: 2016

  12. Optical characteristics of transparent samarium oxide thin films ...

    Indian Academy of Sciences (India)

    2016-10-07

    Oct 7, 2016 ... spectra at nearly normal incident light. The estimated direct optical band gap energy (Ed g) values were found to increase by increasing the annealing temperatures. The dispersion curves of the refractive index of Sm2O3 thin films were found to obey the single oscillator model. Keywords. Transparent oxide ...

  13. Microstructural and optical properties of transparent conductive ZnO ...

    Indian Academy of Sciences (India)

    Administrator

    Microstructural and optical properties of transparent conductive. ZnO :Al : Mo films deposited by template-assisted sol–gel method. H -Y HE*, J -F HUANG, Z HE, J LU and Q SHEN. College of Materials Science and Engineering, Shaanxi University of Science and Technology, China 710021. MS received 11 November 2012 ...

  14. Optical characteristics of transparent samarium oxide thin films ...

    Indian Academy of Sciences (India)

    Transparent metal oxide thin films of samarium oxide (Sm 2 O 3 ) were prepared on pre-cleaned fused optically flat quartz substrates by radio-frequency (RF) sputtering technique. The as-deposited thin films were annealed at different temperatures (873, 973 and 1073 K) for 4 h in air under normal atmospheric pressure.

  15. Mechanically flexible optically transparent porous mono-crystalline silicon substrate

    KAUST Repository

    Rojas, Jhonathan Prieto

    2012-01-01

    For the first time, we present a simple process to fabricate a thin (≥5μm), mechanically flexible, optically transparent, porous mono-crystalline silicon substrate. Relying only on reactive ion etching steps, we are able to controllably peel off a thin layer of the original substrate. This scheme is cost favorable as it uses a low-cost silicon <100> wafer and furthermore it has the potential for recycling the remaining part of the wafer that otherwise would be lost and wasted during conventional back-grinding process. Due to its porosity, it shows see-through transparency and potential for flexible membrane applications, neural probing and such. Our process can offer flexible, transparent silicon from post high-thermal budget processed device wafer to retain the high performance electronics on flexible substrates. © 2012 IEEE.

  16. Investigations on magnetic field induced optical transparency in magnetic nanofluids

    Science.gov (United States)

    Mohapatra, Dillip Kumar; Philip, John

    2018-02-01

    We study the magnetic field induced optical transparency and its origin in magnetic nanoemulsion of droplets of average size ∼200 nm containing superparamagnetic iron oxide nanoparticles. Beyond a certain volume fraction (Φ > 0.0021) of magnetic nanoemulsion and a critical magnetic field (Hc1), the transmitted light intensity increases drastically and reaches a maximum at another critical magnetic field (Hc2), beyond which the transmitted light intensity decreases and reaches a plateau. Interestingly, the transmitted light intensity at Hc2 is found to increase linearly with Φ and the critical magnetic fields Hc1 and Hc2 follow power law decay with Φ (i.e. Hc ∼ Φ-x), with exponents 0.48 and 0.27, respectively. The light intensity recovers to its initial value when the magnetic field is switched off, indicating the perfect reversibility of the field induced transparency process. The observed straight line scattered patterns above Hc2, on a screen placed perpendicular to the incident beam, confirms the formation of rod like anisotropic nanostructures perpendicular to the direction of light propagation. The magneto-optical measurements in the emulsion confirm that the observed field induced transparency in magnetic emulsions for Φ > 0.0021 is due to the optical birefringence caused by the rod like nanostructures. The reduced birefringence is found to be proportional to the square of the applied magnetic field. This finding offers several possibilities in using magnetic nanofluids in tunable optical devices.

  17. Electrically conductive, optically transparent polymer/carbon nanotube composites

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Jr., Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  18. Electrically modulated transparent liquid crystal-optical grating projection

    DEFF Research Database (Denmark)

    Buss, Thomas; Smith, Cameron; Kristensen, Anders

    2013-01-01

    A transparent, fully integrated electrically modulated projection technique is presented based on light guiding through a thin liquid crystal layer covering sub-wavelength gratings. The reported device operates at 10 V with response times of 4.5 ms. Analysis of the liquid crystal alignment shows...

  19. Transparency

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel

    2016-01-01

    This article challenges the view of transparency as a matter of providing openness, insight, and clarity by conceptualizing it as a form of visibility management. We tend to think of transparency as a process of ensuring accountability through the timely and public disclosure of information...... articulates the complexities and dynamics of visibility management and highlights a set of critical questions about the politics, technologies, and power effects of contemporary transparency regimes....

  20. Transparent, flexible, and solid-state supercapacitors based on graphene electrodes

    Directory of Open Access Journals (Sweden)

    Y. Gao

    2013-07-01

    Full Text Available In this study, graphene-based supercapacitors with optical transparency and mechanical flexibility have been achieved using a combination of poly(vinyl alcohol/phosphoric acid gel electrolyte and graphene electrodes. An optical transmittance of ∼67% in a wavelength range of 500-800 nm and a 92.4% remnant capacitance under a bending angle of 80° have been achieved for the supercapacitors. The decrease in capacitance under bending is ascribed to the buckling of the graphene electrode in compression. The supercapacitors with high optical transparency, electrochemical stability, and mechanical flexibility hold promises for transparent and flexible electronics.

  1. Transparency

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Albu, Oana Brindusa

    2017-01-01

    Transparency is an increasingly prominent research topic in many scholarly disciplines and offers valuable insights for organizational communication. This entry provides an overview of the historical background and identifies some themes that presently inform the transparency literature. The entry...... then outlines the most important dimensions of the concept of transparency by highlighting two paradigmatic positions underpinning contemporary research in this area: namely, informational approaches that focus on the sharing of information and the perceived quality of that information and social process...... orientations that explore the dynamics of transparency in organizational settings. The entry highlights emergent methodological and conceptual insights concerning transparency as a dynamic and paradoxical social process with performative characteristics – an approach that remains underexplored....

  2. Transparent conducting oxides for electro-optical plasmonic modulators

    Directory of Open Access Journals (Sweden)

    Babicheva Viktoriia E.

    2015-06-01

    Full Text Available The ongoing quest for ultra-compact optical devices has reached a bottleneck due to the diffraction limit in conventional photonics. New approaches that provide subwavelength optical elements, and therefore lead to miniaturization of the entire photonic circuit, are urgently required. Plasmonics, which combines nanoscale light confinement and optical-speed processing of signals, has the potential to enable the next generation of hybrid information-processing devices, which are superior to the current photonic dielectric components in terms of speed and compactness. New plasmonic materials (other than metals, or optical materials with metal-like behavior, have recently attracted a lot of attention due to the promise they hold to enable low-loss, tunable, CMOScompatible devices for photonic technologies. In this review, we provide a systematic overview of various compact optical modulator designs that utilize a class of the most promising new materials as the active layer or core— namely, transparent conducting oxides. Such modulators can be made low-loss, compact, and exhibit high tunability while offering low cost and compatibility with existing semiconductor technologies. A detailed analysis of different configurations and their working characteristics, such as their extinction ratio, compactness, bandwidth, and losses, is performed identifying the most promising designs.

  3. Ultra-Thin Optically Transparent Carbon Electrodes Produced from Layers of Adsorbed Proteins

    Science.gov (United States)

    Alharthi, Sarah A.; Benavidez, Tomas E.; Garcia, Carlos D.

    2013-01-01

    This work describes a simple, versatile, and inexpensive procedure to prepare optically transparent carbon electrodes, using proteins as precursors. Upon adsorption, the protein-coated substrates were pyrolyzed under reductive conditions (5% H2) to form ultra-thin, conductive electrodes. Because proteins spontaneously adsorb to interfaces forming uniform layers, the proposed method does not require a precise control of the preparation conditions, specialized instrumentation, or expensive precursors. The resulting electrodes were characterized by a combination of electrochemical, optical, and spectroscopic means. As a proof-of-concept, the optically-transparent electrodes were also used as substrate for the development of an electrochemical glucose biosensor. The proposed films represent a convenient alternative to more sophisticated, and less available, carbon-based nanomaterials. Furthermore, these films could be formed on a variety of substrates, without classical limitations of size or shape. PMID:23421732

  4. Optically Transparent Thin-Film Electrode Chip for Spectroelectrochemical Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Shirmir D.; Lines, Amanda M.; Lynch, John A.; Bello, Job M.; Heineman, William R.; Bryan, Samuel A.

    2017-07-03

    The electrochemical and spectroelectrochemical applications of an optically transparent thin film electrode chip are investigated. The working electrode is composed of indium tin oxide (ITO); the counter and quasi-reference electrodes are composed of platinum. The stability of the platinum quasi-reference electrode is modified by coating it with a planar, solid state Ag/AgCl layer. The Ag/AgCl reference is characterized with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Open circuit potential measurements indicate that the potential of the planar Ag/AgCl electrode varies a maximum of 20 mV over four days. Cyclic voltammetry measurements show that the electrode chip is comparable to a standard electrochemical cell. Randles-Sevcik analysis of 10 mM K3[Fe(CN)6] in 0.1 M KCl using the electrode chip shows a diffusion coefficient of 1.59 × 10-6 cm2/s, in comparison to the standard electrochemical cell value of 2.38 × 10-6 cm2/s. By using the electrode chip in an optically transparent thin layer electrode (OTTLE), the spectroelectrochemical modulation of [Ru(bpy)3]2+ florescence was demonstrated, achieving a detection limit of 36 nM.

  5. Two-dimensional materials based transparent flexible electronics

    Science.gov (United States)

    Yu, Lili; Ha, Sungjae; El-Damak, Dina; McVay, Elaine; Ling, Xi; Chandrakasan, Anantha; Kong, Jing; Palacios, Tomas

    2015-03-01

    Two-dimensional (2D) materials have generated great interest recently as a set of tools for electronics, as these materials can push electronics beyond traditional boundaries. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. These thin, lightweight, bendable, highly rugged and low-power devices may bring dramatic changes in information processing, communications and human-electronic interaction. In this report, for the first time, we demonstrate two complex transparent flexible systems based on molybdenum disulfide (MoS2) grown by chemical vapor method: a transparent active-matrix organic light-emitting diode (AMOLED) display and a MoS2 wireless link for sensor nodes. The 1/2 x 1/2 square inch, 4 x 5 pixels AMOLED structures are built on transparent substrates, containing MoS2 back plane circuit and OLEDs integrated on top of it. The back plane circuit turns on and off the individual pixel with two MoS2 transistors and a capacitor. The device is designed and fabricated based on SPICE simulation to achieve desired DC and transient performance. We have also demonstrated a MoS2 wireless self-powered sensor node. The system consists of as energy harvester, rectifier, sensor node and logic units. AC signals from the environment, such as near-field wireless power transfer, piezoelectric film and RF signal, are harvested, then rectified into DC signal by a MoS2 diode. CIQM, CICS, SRC.

  6. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    Directory of Open Access Journals (Sweden)

    Aliya A. Dewani

    2015-02-01

    Full Text Available A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm, flexible transparent plastic substrate (relative permittivity 3.2. It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  7. Spectroscopic and electrochemical characterization of nanostructured optically transparent carbon electrodes.

    Science.gov (United States)

    Benavidez, Tomás E; Garcia, Carlos D

    2013-07-01

    The present paper describes the results related to the optical and electrochemical characterization of thin carbon films fabricated by spin coating and pyrolysis of AZ P4330-RS photoresist. The goal of this paper is to provide comprehensive information allowing for the rational selection of the conditions to fabricate optically transparent carbon electrodes (OTCE) with specific electrooptical properties. According to our results, these electrodes could be appropriate choices as electrochemical transducers to monitor electrophoretic separations. At the core of this manuscript is the development and critical evaluation of a new optical model to calculate the thickness of the OTCE by variable angle spectroscopic ellipsometry. Such data were complemented with topography and roughness (obtained by atomic force microscopy), electrochemical properties (obtained by cyclic voltammetry), electrical properties (obtained by electrochemical impedance spectroscopy), and structural composition (obtained by Raman spectroscopy). Although the described OTCE were used as substrates to investigate the effect of electrode potential on the real-time adsorption of proteins by ellipsometry, these results could enable the development of other biosensors that can be then integrated into various CE platforms. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Theoretical Analysis and Design of Ultrathin Broadband Optically Transparent Microwave Metamaterial Absorbers

    Directory of Open Access Journals (Sweden)

    Ruixiang Deng

    2018-01-01

    Full Text Available Optically Transparent Microwave Metamaterial Absorber (OTMMA is of significant use in both civil and military field. In this paper, equivalent circuit model is adopted as springboard to navigate the design of OTMMA. The physical model and absorption mechanisms of ideal lightweight ultrathin OTMMA are comprehensively researched. Both the theoretical value of equivalent resistance and the quantitative relation between the equivalent inductance and equivalent capacitance are derived for design. Frequency-dependent characteristics of theoretical equivalent resistance are also investigated. Based on these theoretical works, an effective and controllable design approach is proposed. To validate the approach, a wideband OTMMA is designed, fabricated, analyzed and tested. The results reveal that high absorption more than 90% can be achieved in the whole 6~18 GHz band. The fabricated OTMMA also has an optical transparency up to 78% at 600 nm and is much thinner and lighter than its counterparts.

  9. Oxidation of copper nanowire based transparent electrodes in ambient conditions and their stabilization by encapsulation: application to transparent film heaters

    Science.gov (United States)

    Celle, Caroline; Cabos, Anthony; Fontecave, Thomas; Laguitton, Bruno; Benayad, Anass; Guettaz, Laure; Pélissier, Nathalie; Huong Nguyen, Viet; Bellet, Daniel; Muñoz-Rojas, David; Simonato, Jean-Pierre

    2018-02-01

    Whereas the integration of silver nanowires in functional devices has reached a fair level of maturity, the integration of copper nanowires still remains difficult, mainly due to the intrinsic instability of copper nanowires in ambient conditions. In this paper, copper nanowire based transparent electrodes with good performances (33 Ω sq-1 associated with 88% transparency) were obtained, and their degradation in different conditions was monitored, in particular by electrical measurements, transmission electron microscopy, x-ray photoelectron spectrometry and Auger electron spectroscopy. Several routes to stabilize the random networks of copper nanowires were evaluated. Encapsulation through laminated barrier film with optical clear adhesive and atmospheric pressure spatial atomic layer deposition were found to be efficient and were used for the fabrication of transparent film heaters.

  10. Optically transparent, superhydrophobic, biocompatible thin film coatings and methods for producing same

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Beth L.; Aytug, Tolga; Paranthaman, Mariappan Parans; Simpson, John T.; Hillesheim, Daniel A.; Trammell, Neil E.

    2017-09-05

    An optically transparent, hydrophobic coating, exhibiting an average contact angle of at least 100 degrees with a drop of water. The coating can be produced using low-cost, environmentally friendly components. Methods of preparing and using the optically transparent, hydrophobic coating.

  11. Fully transparent thin-film transistor devices based on SnO2 nanowires.

    Science.gov (United States)

    Dattoli, Eric N; Wan, Qing; Guo, Wei; Chen, Yanbin; Pan, Xiaoqing; Lu, Wei

    2007-08-01

    We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nano-wires. The nanowire-based devices exhibit uniform characteristics with average field-effect mobilities exceeding 100 cm2/V x s. Prototype nano-wire-based TFT (NW-TFT) devices on glass substrates showed excellent optical transparency and transistor performance in terms of transconductance, bias voltage range, and on/off ratio. High on-currents and field-effect mobilities were obtained from the NW-TFT devices even at low nanowire coverage. The SnO2 nanowire-based TFT approach offers a number of desirable properties such as low growth cost, high electron mobility, and optical transparency and low operation voltage, and may lead to large-scale applications of transparent electronics on diverse substrates.

  12. An optically transparent metasurface for broadband microwave antireflection

    Science.gov (United States)

    Zhao, Jie; Zhang, Cheng; Cheng, Qiang; Yang, Jin; Cui, Tie Jun

    2018-02-01

    Metamaterial absorbers and diffusers provide powerful routes to decrease the backward reflection significantly with advantages of ultrathin profile and customized bandwidth. Simultaneous control of the absorption and scattering behaviors of the metamaterials which helps to improve the suppression capabilities of backward reflection, however, still remains a challenge. Aiming at this goal, we propose a metasurface constituted by two kinds of elements in a pseudorandom arrangement. By the use of indium tin oxide with moderate sheet resistance in the meta-atoms, enhanced absorption of energy can be achieved in a broad spectrum when interacted with illuminated waves. In the meanwhile, electromagnetic diffusion will be invoked from the destructive interference among the elements, giving rise to significant reduction of specular reflection as a result. Excellent agreements are observed between simulation and experiment with pronounced reflection suppression from 6.8 GHz to 19.4 GHz. In addition, the optical transparence of the patterns and substrates makes the proposed metasurface a promising candidate for future applications like photovoltaic solar cells and electromagnetic shielding glasses.

  13. Optically transparent UWB antenna for wireless application & energy harvesting

    OpenAIRE

    Peter, Thomas

    2012-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Transparent UWB antennas have been the focus of this PhD research. The use of transparent UWB antennas for stealth and energy harvesting has been the underlying applications that have given impetus to this research. Such transparent antennas being built on materials that are discreet, flexible, conformal, conductive and having the ability to provide good antenna performance on glass to ser...

  14. Generation and control of optical frequency combs using cavity electromagnetically induced transparency

    Science.gov (United States)

    Li, Jiahua; Qu, Ye; Yu, Rong; Wu, Ying

    2018-02-01

    We explore theoretically the generation and all-optical control of optical frequency combs (OFCs) in photon transmission based on a combination of single-atom-cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT). Here an external control field is used to form the cavity dark mode of the CQED system. When the strengths of the applied EIT control field are appropriately tuned, enhanced comb generation can be achieved. We discuss the properties of the dark mode and clearly show that the formation of the dark mode enables the efficient generation of OFCs. In our approach, the comb spacing is determined by the beating frequency between the driving pump and seed lasers. Our demonstrated theory may pave the way towards all-optical coherent control of OFCs using a CQED architecture.

  15. Secured Optical Communications Using Quantum Entangled Two-Photon Transparency Modulation

    Science.gov (United States)

    Kojima, Jun (Inventor); Nguyen, Quang-Viet (Inventor); Lekki, John (Inventor)

    2015-01-01

    A system and method is disclosed wherein optical signals are coded in a transmitter by tuning or modulating the interbeam delay time (which modulates the fourth-order coherence) between pairs of entangled photons. The photon pairs are either absorbed or not absorbed (transparent) by an atomic or molecular fluorescer in a receiver, depending on the inter-beam delay that is introduced in the entangled photon pairs. Upon the absorption, corresponding fluorescent optical emissions follow at a certain wavelength, which are then detected by a photon detector. The advantage of the disclosed system is that it eliminates a need of a coincidence counter to realize the entanglement-based secure optical communications because the absorber acts as a coincidence counter for entangled photon pairs.

  16. Review of flexible and transparent thin-film transistors based on zinc oxide and related materials

    Science.gov (United States)

    Zhang, Yong-Hui; Mei, Zeng-Xia; Liang, Hui-Li; Du, Xiao-Long

    2017-04-01

    Flexible and transparent electronics enters into a new era of electronic technologies. Ubiquitous applications involve wearable electronics, biosensors, flexible transparent displays, radio-frequency identifications (RFIDs), etc. Zinc oxide (ZnO) and relevant materials are the most commonly used inorganic semiconductors in flexible and transparent devices, owing to their high electrical performances, together with low processing temperatures and good optical transparencies. In this paper, we review recent advances in flexible and transparent thin-film transistors (TFTs) based on ZnO and relevant materials. After a brief introduction, the main progress of the preparation of each component (substrate, electrodes, channel and dielectrics) is summarized and discussed. Then, the effect of mechanical bending on electrical performance is highlighted. Finally, we suggest the challenges and opportunities in future investigations. Project supported by the National Natural Science Foundation of China (Grants Nos. 61306011, 11274366, 51272280, 11674405, and 11675280).

  17. Dynamic Holography Method for Nondestructive Testing of Optical Homogeneity of Transparent Media

    Energy Technology Data Exchange (ETDEWEB)

    Bogodaev, N. V.; Ivleva, L. I., E-mail: ivleva@ran.gpi.ru; Lykov, P. A.; Osiko, V. V.; Gordeev, A. A. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2010-11-15

    The potential of the dynamic holography method for testing the phase optical homogeneity of media transparent in visible light has been considered. This method is based on imaging samples in the scheme of two-wave mixing of the second-harmonic radiation of a Nd:YAG laser and image amplification in a photorefractive barium-strontium niobate crystal. Examples of identifying phase inhomogeneities at a level of 10{sup -5} cm{sup -1} and less in crystals of different compositions are presented.

  18. Corundum-based transparent infrared absorbers

    KAUST Repository

    Schwingenschlögl, Udo

    2009-10-01

    Hypothetical corundum-based compounds are studied by electronic structure calculations. One quarter of the Al atoms in Al2O3 is replaced by a 3d transition metal from the M = Ti, ..., Zn (d1, ..., d9) series. Structure optimisations are performed for all the M-Al2O3 compounds and the electronic states are evaluated. Due to the M substitutes, narrow partially filled bands are formed at the Fermi energy. Beyond, for M = Ni and M = Cu the optical properties of Al2O3 in the visible range are conserved, while for M = Ti, ..., Co the systems form high accuracy optical filters. Since the compounds absorb the infrared radiation, the M = Ni and M = Cu systems are good candidates for heat-protective coatings. © 2009 Elsevier B.V. All rights reserved.

  19. Radio-frequency transparent demodulation for broadband hybrid wireless-optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Sambaraju, Rakesh; Alemany, Ruben

    2010-01-01

    A novel demodulation technique which is transparent to radio-frequency (RF) carrier frequency is presented and experimentally demonstrated for multigigabit wireless signals. The presented demodulation technique employs optical single-sideband filtering, coherent detection, and baseband digital si...

  20. High-Strength and Optically Transparent Fiber-Reinforced Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For many applications there exists a need for mechanically strong composite materials of high optical quality and transparency equivalent to window glass. One method...

  1. Transparent non-linear optical composites based on glass and ferroelectric KNbSi.sub.2./sub.O.sub.7./sub..

    Czech Academy of Sciences Publication Activity Database

    Sigaev, V. N.; Sukhov, S.S.; Sarkisov, P. D.; Stefanovich, S. Yu.; Pernice, P.; Aronne, A.; Gregora, Ivan

    2005-01-01

    Roč. 318, - (2005), s. 95-104 ISSN 0015-0193 Grant - others:Russian Fondation of Basic Research(RU) 02-03-32105; NATO SfP program(XX) SfP -977980; Italien Ministry of Education, Univerity and Research, FIRB(IT) RBNE0155X7 Institutional research plan: CEZ:AV0Z10100520 Keywords : ferroelectric * glass composites * optical non-linearity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.459, year: 2005

  2. Mechanically flexible and optically transparent three-dimensional nanofibrous amorphous aerocellulose.

    Science.gov (United States)

    Ayadi, Farouk; Martín-García, Beatriz; Colombo, Massimo; Polovitsyn, Anatolii; Scarpellini, Alice; Ceseracciu, Luca; Moreels, Iwan; Athanassiou, Athanassia

    2016-09-20

    Aerocelluloses are considered as "third generation" aerogels after the silica and synthetic polymer-based ones. However, their brittleness and low optical translucency keep quite narrow their fields of applications. Here, both issues are addressed successfully through the fabrication of flexible and mechanically robust amorphous aerocellulose with high optical transparency, using trifluoroacetic acid as a solvent and ethanol as a non-solvent. The developed aerocellulose displays a meso-macroporous interconnected nanofibrous cellulose skeleton with low density and high specific surface area. We demonstrate its high efficiency as supporting matrix for nanoscale systems by incorporating a variety of colloidal quatum dots, that provide bright and stable photoluminescence to the flexible aerocellulose host. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. TRANSPARENCY IN ELECTRONIC BUSINESS NEGOTIATIONS – EVIDENCE BASED ANALYSIS

    Directory of Open Access Journals (Sweden)

    Radoslav Delina

    2014-12-01

    Full Text Available Purpose: In current economy, where ICT plays a crucial role for being competitive and effective, businesses are facing higher pressures of flexibility and efficiency than ever before. Transparency is often considered as a suitable mechanism for better market prices and more efficient market environment. Electronic business environment provides the possibility to set up more transparent environment and bring higher competitiveness and efficiency on the market. The paper analyse the impact of transparency on prices in e-procurement.Methodology: Reverse auctions are considered as transparent tool simulating in partial level real competition. Together, it allows to examine several levels of transparency set up in auction negotiation process. The impact of transparency on final prices was analysed on real data using relation based analysis were different situations of transparency set up is compared against achieved final price.Findings: Research results based on real data shows, that generally, the transparency in electronic reverse auction can lead to more negative prices agreed by purchasers as current scientific and commercial promotions.Research limitation: Significance of research results is limited due to still low readiness and skills of e-procurers. The validation of results is needed to realized within longer period of time and from environments with different level of e-readiness. Together, it reveal that transparency is more complex issue where the significance of transparency can reveal its sense in some specific situations on the market and negotiation.Value of paper: Evidenced based research reveal some controversy results which support new scientific efforts in microeconomics and socio-economic impact of ICT fields. Together, it affects real practitioners in way how to use and perceive claimed impact of reverse auction solutions.

  4. Transparent conducting oxides for electro-optical plasmonic modulators

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Boltasseva, Alexandra; Lavrinenko, Andrei V.

    2015-01-01

    of themost promising new materials as the active layer or core—namely, transparent conducting oxides. Such modulatorscan be made low-loss, compact, and exhibit high tunabilitywhile offering low cost and compatibility with existingsemiconductor technologies. A detailed analysis of differentconfigurations...

  5. Microstructural and optical properties of transparent conductive ZnO ...

    Indian Academy of Sciences (India)

    Administrator

    Transparent conductive ZnO : Al : Mo films with a molar ratio of Zn : Al : Mo = 99 : 0⋅99 : 0⋅01 ... electronic industries, including solar cells, gas sensors, ... prevent the formation of hydroxide. The volume of the solution was expanded to 100 mL by adding ethanol, so that the molar concentration of the Zn2+ cation reached.

  6. Optical storage with electromagnetically induced transparency in cold atoms at a high optical depth

    Science.gov (United States)

    Zhang, Shanchao; Zhou, Shuyu; Liu, Chang; Chen, J. F.; Wen, Jianming; Loy, M. M. T.; Wong, G. K. L.; Du, Shengwang

    2012-06-01

    We report experimental demonstration of efficient optical storage with electromagnetically induced transparency (EIT) in a dense cold ^85Rb atomic ensemble trapped in a two-dimensional magneto-optical trap. By varying the optical depth (OD) from 0 to 140, we observe that the optimal storage efficiency for coherent optical pulses has a saturation value of 50% as OD > 50. Our result is consistent with that obtained from hot vapor cell experiments which suggest that a four-wave mixing nonlinear process degrades the EIT storage coherence and efficiency. We apply this EIT quantum memory for narrow-band single photons with controllable waveforms, and obtain an optimal storage efficiency of 49±3% for single-photon wave packets. This is the highest single-photon storage efficiency reported up to today and brings the EIT atomic quantum memory close to practical application because an efficiency of above 50% is necessary to operate the memory within non-cloning regime and beat the classical limit.

  7. Accounting for PMD Temporal Correlation During Lightpath Set Up in Transparent Optical Networks

    DEFF Research Database (Denmark)

    Sambo, Nicola; Secondini, Marco; Andriolli, Nicola

    2010-01-01

    stochastic characteristics. Moreover, PMD depends on time-variant factors, such as the temperature and the fiber stress. When implementing a dynamic GMPLS-controlled transparent optical network, the GMPLS protocol suite must take into account physical impairment information in order to establish lightpaths...... that the instantaneous DGD is not detrimental. Additionally, given PMD temporal correlation properties, once that the instantaneous DGD is not detrimental, it continues to be not detrimental within considerable time ranges. Therefore, more accurate models can be implemented in the GMPLS control plane to account for PMD....... In this paper we propose a novel lightpath provisioning scheme based on a PMD prediction model which accounts for PMD temporal correlation properties. The proposed PMD-temporal-correlation (PTC) based lightpath provisioning scheme is compared with a scheme based on a classical PMD model. Simulation results show...

  8. Three-dimensional graphene foam-based transparent conductive electrodes in GaN-based blue light-emitting diodes

    Science.gov (United States)

    Kim, Byung-Jae; Yang, Gwangseok; Joo Park, Min; Seop Kwak, Joon; Hyeon Baik, Kwang; Kim, Donghwan; Kim, Jihyun

    2013-04-01

    We demonstrated three-dimensional (3D) graphene foam-based transparent conductive electrodes in GaN-based blue light-emitting diodes (LEDs). A 3D graphene foam structure grown on 3D Cu foam using a chemical vapor deposition method was transferred onto a p-GaN layer of blue LEDs. Optical and electrical performances were greatly enhanced by employing 3D graphene foam as transparent conductive electrodes in blue LED devices, which were analyzed by electroluminescence measurements, micro-Raman spectroscopy, and light intensity-current-voltage testing. The forward operating voltage and the light output power at an injection current of 100 mA of the GaN-based blue LEDs with a graphene foam-based transparent conductive electrode were improved by ˜26% and ˜14%, respectively. The robustness, high transmittance, and outstanding conductivity of 3D graphene foam show great potentials for advanced transparent conductive electrodes in optoelectronic devices.

  9. An optically transparent, flexible, patterned and conductive silk biopolymer film (Conference Presentation)

    Science.gov (United States)

    Umar, Muhammad; Min, Kyungtaek; Kim, Sunghwan

    2017-02-01

    Transparent, flexible, and conducting films are of great interest for wearable electronics. For better biotic/abiotic interface, the films to integrate the electronics components requires the patterned surface conductors with optical transparency, smoothness, good electrical conductivity, along with the biofriendly traits of films. We focus on silk fibroin, a natural biopolymer extracted from the Bombyx mori cocoons, for this bioelectronics applications. Here we report an optically transparent, flexible, and patterned surface conductor on a silk film by burying a silver nanowires (AgNW) network below the surface of the silk film. The conducting silk film reveals high optical transparency of 80% and the excellent electronic conductivity of 15 Ω/sq, along with smooth surface. The integration of light emitting diode (LED) chip on the patterned electrodes confirms that the current can flow through the transparent and patterned electrodes on the silk film, and this result shows an application for integration of functional electronic/opto-electronic devices. Additionally, we fabricate a transparent and flexible radio frequency (RF) antenna and resistor on a silk film and apply these as a food sensor by monitoring the increasing resistance by the flow of gases from the spoiled food.

  10. An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Ooi, P.C. [Mechanical Engineering, The University of Auckland (New Zealand); Aw, K.C., E-mail: k.aw@auckland.ac.nz [Mechanical Engineering, The University of Auckland (New Zealand); Gao, W. [Chemical and Materials Engineering, The University of Auckland (New Zealand); Razak, K.A. [School of Materials and Mineral Resources Engineering, Universiti Sains (Malaysia); NanoBiotechnology Research and Innovation, INFORMM, Universiti Sains (Malaysia)

    2013-10-01

    In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted.

  11. An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

    International Nuclear Information System (INIS)

    Ooi, P.C.; Aw, K.C.; Gao, W.; Razak, K.A.

    2013-01-01

    In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted

  12. Optical characteristics of transparent samarium oxide thin films ...

    Indian Academy of Sciences (India)

    2016-10-07

    Oct 7, 2016 ... important factor in optical communication. The deter- mination of the optical properties of any ... Post-annealing treatment plays a critical role in the final structure and properties of the TMO thin films. ..... A significant success of Wemple and Di Domenico model is that it relates the dispersion energy (Ed).

  13. Transparent, Flexible Strain Sensor Based on a Solution-Processed Carbon Nanotube Network.

    Science.gov (United States)

    Lee, Jieun; Lim, Meehyun; Yoon, Jinsu; Kim, Min Seong; Choi, Bongsik; Kim, Dong Myong; Kim, Dae Hwan; Park, Inkyu; Choi, Sung-Jin

    2017-08-09

    The demands for transparent, flexible electronic devices are continuously increasing due to their potential applications to the human body. In particular, skin-like, transparent, flexible strain sensors have been developed to realize multifunctional human-machine interfaces. Here, we report a sandwich-like structured strain sensor with excellent optical transparency based on highly purified, solution-processed, 99% metallic CNT-polydimethylsiloxane (PDMS) composite thin films. Our CNT-PDMS composite strain sensors are mechanically compliant, physically robust, and easily fabricated. The fabricated strain sensors exhibit a high optical transparency of over 92% in the visible range with acceptable sensing performances in terms of sensitivity, hysteresis, linearity, and drift. We also found that the sensitivity and linearity of the strain sensors can be controlled by the number of CNT sprays; hence, our sensor can be applied and controlled based on the need of individual applications. Finally, we investigated the detections of human activities and emotions by mounting our transparent strain sensor on various spots of human skins.

  14. Transparent ceramic photo-optical semiconductor high power switches

    Science.gov (United States)

    Werne, Roger W.; Sullivan, James S.; Landingham, Richard L.

    2016-01-19

    A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.

  15. Transparent silicon strip sensors for the optical alignment of particle detector systems

    International Nuclear Information System (INIS)

    Blum, W.; Kroha, H.; Widmann, P.

    1995-05-01

    Modern large-area precision tracking detectors require increasing accuracy for the alignment of their components. A novel multi-point laser alignment system has been developed for such applications. The position of detector components with respect to reference laser beams is monitored by semi-transparent optical position sensors which work on the principle of silicon strip photodiodes. Two types of custom designed transparent strip sensors, based on crystalline and on amorphous silicon as active material, have been studied. The sensors are optimised for the typical diameters of collimated laser beams of 3-5 mm over distances of 10-20 m. They provide very high position resolution, on the order of 1 μm, uniformly over a wide measurement range of several centimeters. The preparation of the sensor surfaces requires special attention in order to achieve high light transmittance and minimum distortion of the traversing laser beams. At selected wavelengths, produced by laser diodes, transmission rates above 90% have been achieved. This allows to position more than 30 sensors along one laser beam. The sensors will be equipped with custom designed integrated readout electronics. (orig.)

  16. Transparent infrared-emitting CeF3:Yb-Er polymer nanocomposites for optical applications.

    Science.gov (United States)

    Tan, Mei Chee; Patil, Swanand D; Riman, Richard E

    2010-07-01

    Bright infrared-emitting nanocomposites of unmodified CeF(3):Yb-Er with polymethyl-methacrylate (PMMA) and polystyrene (PS), which offer a vast range of potential applications, which include optical amplifiers, waveguides, laser materials, and implantable medical devices, were developed. For the optical application of these nanocomposites, it is critical to obtain highly transparent composites to minimize absorption and scattering losses. Preparation of transparent composites typically requires powder processing approaches that include sophisticated particle size control, deagglomeration, and dispersion stabilization methods leading to an increase in process complexity and processing steps. This work seeks to prepare transparent composites with high solids loading (>5 vol%) by matching the refractive index of the inorganic particle with low cost polymers like PMMA and PS, so as to circumvent the use of any complex processing techniques or particle surface modification. PS nanocomposites were found to exhibit better transparency than the PMMA nanocomposites, especially at high solids loading (>/=10 vol%). It was found that the optical transparency of PMMA nanocomposites was more significantly affected by the increase in solids loading and inorganic particle size because of the larger refractive index mismatch of the PMMA nanocomposites compared to that of PS nanocomposites. Rayleigh scattering theory was used to provide a theoretical estimate of the scattering losses in these ceramic-polymer nanocomposites.

  17. A transparent Pyrex μ-reactor for combined in situ optical characterization and photocatalytic reactivity measurements

    International Nuclear Information System (INIS)

    Dionigi, F.; Hansen, O.; Nielsen, M. G.; Chorkendorff, I.; Vesborg, P. C. K.; Pedersen, T.

    2013-01-01

    A new Pyrex-based μ-reactor for photocatalytic and optical characterization experiments is presented. The reactor chamber and gas channels are microfabricated in a thin poly-silicon coated Pyrex chip that is sealed with a Pyrex lid by anodic bonding. The device is transparent to light in the UV-vis-near infrared range of wavelengths (photon energies between ∼0.4 and ∼4.1 eV). The absorbance of a photocatalytic film obtained with a light transmission measurement during a photocatalytic reaction is presented as a proof of concept of a photocatalytic reactivity measurement combined with in situ optical characterization. Diffuse reflectance measurements of highly scattering photocatalytic nanopowders in a sealed Pyrex μ-reactor are also possible using an integrating sphere as shown in this work. These experiments prove that a photocatalyst can be characterized with optical techniques after a photocatalytic reaction without removing the material from the reactor. The catalyst deposited in the cylindrical reactor chamber can be illuminated from both top and bottom sides and an example of application of top and bottom illumination is presented

  18. Flexible transparent aerogels as window retrofitting films and optical elements with tunable birefringence

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qingkun; Frazier, Allister W.; Zhao, Xinpeng; De La Cruz, Joshua A.; Hess, Andrew J.; Yang, Ronggui; Smalyukh, Ivan I.

    2018-06-01

    Experimental realization of optically transparent, mechanically robust and flexible aerogels has been a longstanding challenge, which limits their practical applications in energy-saving devices, such as thermally insulating films for enhancing energy efficiency of windows. The poor transparency precluded even hypothetical consideration of the possibility of birefringent aerogels. We develop birefringent and optically isotropic aerogels that combine properties of thermal super-insulation, mechanical robustness and flexibility, and transparency to visible-spectrum light. This unusual combination of physical properties is achieved by combining liquid crystalline self-organization of cellulose nanofibers with polysiloxane cross-linking and control of the nanoscale porosity to form hybrid organic-inorganic mesostructured aerogels. Potential applications of these inexpensive materials range from single pane window retrofitting to smart fabrics.

  19. Optical trap for both transparent and absorbing particles in air using a single shaped laser beam.

    Science.gov (United States)

    Redding, Brandon; Pan, Yong-Le

    2015-06-15

    Optical trapping of airborne particles is emerging as an essential tool in applications ranging from online characterization of living cells and aerosols to particle transport and delivery. However, existing optical trapping techniques using a single laser beam can trap only transparent particles (via the radiative pressure force) or absorbing particles (via the photophoretic force), but not particles of either type-limiting the utility of trapping-enabled aerosol characterization techniques. Here, we present the first optical trapping technique capable of trapping both transparent and absorbing particles with arbitrary morphology using a single shaped laser beam. Such a general-purpose optical trapping mechanism could enable new applications such as trapping-enabled aerosol characterization with high specificity.

  20. On optimal designs of transparent WDM networks with 1 + 1 protection leveraged by all-optical XOR network coding schemes

    Science.gov (United States)

    Dao, Thanh Hai

    2018-01-01

    Network coding techniques are seen as the new dimension to improve the network performances thanks to the capability of utilizing network resources more efficiently. Indeed, the application of network coding to the realm of failure recovery in optical networks has been marking a major departure from traditional protection schemes as it could potentially achieve both rapid recovery and capacity improvement, challenging the prevailing wisdom of trading capacity efficiency for speed recovery and vice versa. In this context, the maturing of all-optical XOR technologies appears as a good match to the necessity of a more efficient protection in transparent optical networks. In addressing this opportunity, we propose to use a practical all-optical XOR network coding to leverage the conventional 1 + 1 optical path protection in transparent WDM optical networks. The network coding-assisted protection solution combines protection flows of two demands sharing the same destination node in supportive conditions, paving the way for reducing the backup capacity. A novel mathematical model taking into account the operation of new protection scheme for optimal network designs is formulated as the integer linear programming. Numerical results based on extensive simulations on realistic topologies, COST239 and NSFNET networks, are presented to highlight the benefits of our proposal compared to the conventional approach in terms of wavelength resources efficiency and network throughput.

  1. Graphene-based transparent electrodes for hybrid solar cells

    Directory of Open Access Journals (Sweden)

    Pengfei eLi

    2014-11-01

    Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

  2. Optical and electrical characterization at the nanoscale with a transparent probe of a scanning tunnelling microscope

    International Nuclear Information System (INIS)

    Sychugov, Ilya; Omi, Hiroo; Murashita, Tooru; Kobayashi, Yoshihiro

    2009-01-01

    A new type of scanning probe microscope, combining features of the scanning tunnelling microscope, the scanning tunnelling luminescence microscope with a transparent probe and the aperture scanning near-field optical microscope, is described. Proof-of-concept experiments were performed under ultrahigh vacuum conditions at varying temperature on GaAs/AlAs heterostructures.

  3. Transmission and transparent wavelength conversion of an optically labeled signal using ASK/DPSK orthogonal modulation

    DEFF Research Database (Denmark)

    Chi, Nan; Zhang, Jianfeng; Holm-Nielsen, Pablo Villanueva

    2003-01-01

    We report an experimental investigation of transmission and transparent wavelength conversion properties of a two-level optically labeled signal using amplitude-shift-keying/differential-phase-shift-keying orthogonal modulation. Error-free transmission of a 10-Gb/s payload and 2.5-Gb/s label over...

  4. Preparation, characterization and photocatalytic activity of optically transparent titanium dioxide particles

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Bakardjieva, Snejana; Murafa, Nataliya; Šubrt, Jan; Měšťánková, Hana; Jirkovský, Jaromír

    2007-01-01

    Roč. 105, č. 1 (2007), s. 38-46 ISSN 0254-0584 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40400503 Keywords : optically transparent particles * polyethyleneglycol * anatase Subject RIV: CA - Inorganic Chemistry Impact factor: 1.871, year: 2007

  5. A transparent electrode based on a metal nanotrough network.

    Science.gov (United States)

    Wu, Hui; Kong, Desheng; Ruan, Zhichao; Hsu, Po-Chun; Wang, Shuang; Yu, Zongfu; Carney, Thomas J; Hu, Liangbing; Fan, Shanhui; Cui, Yi

    2013-06-01

    Transparent conducting electrodes are essential components for numerous flexible optoelectronic devices, including touch screens and interactive electronics. Thin films of indium tin oxide-the prototypical transparent electrode material-demonstrate excellent electronic performances, but film brittleness, low infrared transmittance and low abundance limit suitability for certain industrial applications. Alternatives to indium tin oxide have recently been reported and include conducting polymers, carbon nanotubes and graphene. However, although flexibility is greatly improved, the optoelectronic performance of these carbon-based materials is limited by low conductivity. Other examples include metal nanowire-based electrodes, which can achieve sheet resistances of less than 10Ω □(-1) at 90% transmission because of the high conductivity of the metals. To achieve these performances, however, metal nanowires must be defect-free, have conductivities close to their values in bulk, be as long as possible to minimize the number of wire-to-wire junctions, and exhibit small junction resistance. Here, we present a facile fabrication process that allows us to satisfy all these requirements and fabricate a new kind of transparent conducting electrode that exhibits both superior optoelectronic performances (sheet resistance of ~2Ω □(-1) at 90% transmission) and remarkable mechanical flexibility under both stretching and bending stresses. The electrode is composed of a free-standing metallic nanotrough network and is produced with a process involving electrospinning and metal deposition. We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape.

  6. Optoelectrochemical biorecognition by optically transparent highly conductive graphene-modified fluorine-doped tin oxide substrates.

    Science.gov (United States)

    Lamberti, F; Brigo, L; Favaro, M; Luni, C; Zoso, A; Cattelan, M; Agnoli, S; Brusatin, G; Granozzi, G; Giomo, M; Elvassore, N

    2014-12-24

    Both optical and electrochemical graphene-based sensors have gone through rapid development, reaching high sensitivity at low cost and with fast response time. However, the complex validating biochemical operations, needed for their consistent use, currently limits their effective application. We propose an integration strategy for optoelectrochemical detection that overcomes previous limitations of these sensors used separately. We develop an optoelectrochemical sensor for aptamer-mediated protein detection based on few-layer graphene immobilization on selectively modified fluorine-doped tin oxide (FTO) substrates. Our results show that the electrochemical properties of graphene-modified FTO samples are suitable for complex biological detection due to the stability and inertness of the engineered electrodic interface. In addition, few-layer immobilization of graphene sheets through electrostatic linkage with an electrochemically grafted FTO surface allows obtaining an optically accessible and highly conductive platform. As a proof of concept, we used insulin as the target molecule to reveal in solution. Because of its transparency and low sampling volume (a few microliters), our sensing unit can be easily integrated in lab-on-a-chip cell culture systems for effectively monitoring subnanomolar concentrations of proteins relevant for biomedical applications.

  7. Optical label-controlled transparent metro-access network interface

    DEFF Research Database (Denmark)

    Osadchiy, Alexey Vladimirovich

    This thesis presents results obtained during the course of my PhD research on optical signal routing and interfacing between the metropolitan and access segments of optical networks. Due to both increasing capacity demands and variety of emerging services types, new technological challenges...... are arising for seamlessly interfacing metropolitan and access networks. Therefore, in this PhD project, I have analyzed those technological challenges and identified the key aspects to be addressed. I have also proposed and experimentally verified a number of solutions to metropolitan and access networks...... interfacing and signal routing. Equipment and infrastructure simplification was recognized as the path towards more efficient metropolitan and access networks providing a spectrum of high-bandwidth services to large number of users. Several approaches have been proposed and developed in order to enable...

  8. Flexible, Transparent, and Conductive Film Based on Random Networks of Ag Nanowires

    Directory of Open Access Journals (Sweden)

    Shunhua Wang

    2013-01-01

    Full Text Available Flexible, transparent, and conductive films based on random networks of Ag nanowires were prepared by vacuum-filtrating method. The size of Ag nanowires prepared by hydrothermal method is uniform, with a relatively smaller diameter and a longer length, thereby achieving a high aspect ratio (>1000. The films fabricated by Ag nanowires exhibit the excellent transparency with a 92% optical transmittance and a low surface resistivity of 11 Ωsq−1. Importantly, both the transmittance and sheet resistance decrease with the increasing of the Ag nanowires contents. When the contents of Ag nanowires are up to 200 mg/m2 especially, the surface resistivity quickly falls below 5 Ωsq−1. Also, these films are robust, which have almost no change in sheet resistance after the repeating bends over 200 cycles. These encouraging results may have a potential application in flexible and transparent electronics and other heating systems.

  9. Single crystal growth and optical properties of a transparent perovskite oxide LaInO3

    Science.gov (United States)

    Jang, Dong Hyun; Lee, Woong-Jhae; Sohn, Egon; Kim, Hyung Joon; Seo, Dongmin; Park, Ju-Young; Choi, E. J.; Kim, Kee Hoon

    2017-03-01

    Transparent LaInO3 single crystals have been grown using the optical floating zone method. Optimal growth, resulting in the highest optical transparency and best crystallinity, has been found at a growth speed of 15 mm/h and an O2 gas pressure of 10 bar. Under these conditions, single crystals as large as ˜4 × 4 mm2 have been obtained. Chemical compositions and structural analyses reveal that the resulting LaInO3 single crystal is stoichiometric without any impurity phase and forms an orthorhombic perovskite structure. Optical transmission spectra exhibit multiple optical transitions in a wide spectral range (0.5-4.2 eV). Although the main optical absorption occurs at ˜4.13 eV, weak absorption starts to develop from ˜1.4 eV, in agreement with an activation energy of ˜0.7 eV derived from electrical resistivity measurements. The dielectric constant ɛ is found to be 23.7 at room temperature. This LaInO3 single crystal can be used as a transparent perovskite substrate for growing oxide semiconductors with lattice constants close to ˜4.12 Å, such as doped BaSnO3.

  10. Increasing input power dynamic range of SOA by shifting the transparent wavelength of tunable optical filter

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2001-01-01

    Gain-saturation-induced self-phase modulation (SPM) leading to pulse distortion in a semiconductor optical amplifier (SOA) is overcome by shifting a tunable optical filter (TOF). A recovered or broadened pulse can be obtained after filtering the amplified pulse in the SOA even if the short pulse...... to a longer wavelength for RZ signals and to a shorter for NRZ signals. 80-Gb/s optical time division multiplexing (OTDM) signal amplification in the SOA is demonstrated for the first time. We also demonstrate that a large IPDR for the 80-Gb/s OTDM signal can be obtained by shifting the TOF....... is only 2-3 ps long. The input power dynamic range (IPDR) can be strongly increased by shifting the TOF and the direction of the shifted transparent wavelength is different for 10 Gb/s return-to-zero (RZ) or nonreturn-to-zero (NRZ) signals. The transparent wavelength of the TOF should be shifted...

  11. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2013-05-30

    Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  12. Situation Awareness-Based Agent Transparency

    Science.gov (United States)

    2014-04-01

    incorporates natural language instructions (e.g., simple, spoken commands) provided by the supervisor to subordinates based on shared mental models (Calhoun et...Swingley, D.; Gahegan, M. Visual Semiotics and Uncertainty Visualization: An Empirical Study. IEEE Transactions on Visualization and Computer

  13. Toward transparent nanocomposites based on polystyrene matrix and PMMA-grafted CeO2 nanoparticles.

    Science.gov (United States)

    Parlak, Onur; Demir, Mustafa M

    2011-11-01

    The association of transparent polymer and nanosized pigment particles offers attractive optical materials for various potential and existing applications. However, the particles embedded into polymers scatter light due to refractive index (RI) mismatch and reduce transparency of the resulting composite material. In this study, optical composites based on polystyrene (PS) matrix and poly(methyl methacrylate) (PMMA)-grafted CeO(2) hybrid particles were prepared. CeO(2) nanoparticles with an average diameter of 18 ± 8 nm were precipitated by treating Ce(NO(3))·6H(2)O with urea in the presence of a polymerizable surfactant, 3-methacyloxypropyltrimethoxy silane. PMMA chains were grafted on the surface of the nanoparticles upon free radical in situ solution polymerization. While blending of unmodified CeO(2) particles with PS resulted in opaque films, the transparency of the composite films was remarkably enhanced when prepared by PMMA-grafted CeO(2) hybrid particles, particularly those having a PMMA thickness of 9 nm. The improvement in transparency is presumably due to the reduction in RI mismatch between CeO(2) particles and the PS matrix when using PMMA chains at the interface.

  14. Optically transparent super-hydrophobic thin film fabricated by reusable polyurethane-acrylate (PUA) mold

    Science.gov (United States)

    Park, J.-S.; Park, J.-H.; Lee, D.-W.

    2018-02-01

    In this paper, we describe a simple manufacturing method for producing an optically transparent super-hydrophobic polymer thin film using a reusable photo-curable polymer mold. Soluble photoresist (PR) molds were prepared with under-exposed and under-baked processes, which created unique hierarchical micro/nano structures. The reverse phase of the PR mold was replicated on the surface of polydimethylsiloxane (PDMS) substrates. The unique patterns on the replicated PDMS molds were successfully transferred back to the UV curable polyurethane-acrylate (PUA) using a laboratory-made UV exposure system. Continuous production of the super-hydrophobic PDMS thin film was demonstrated using the reusable PUA mold. In addition, hydrophobic nano-silica powder was sprayed onto the micro/nano structured PDMS surfaces to further improve hydrophobicity. The fabricated PDMS thin films with hierarchical surface texturing showed a water contact angle  ⩾150°. Excellent optical transmittance within the range of visible light of wavelengths between 400-800 nm was experimentally confirmed using a spectrophotometer. High efficiency of the super-hydrophobic PDMS film in optical transparency was also confirmed using solar panels. The fabricated PUA molds are very suitable for use in roll-to-roll or roll-to-plate systems which allow continuous production of super-hydrophobic thin films with an excellent optical transparency.

  15. Broadband optical modulators based on graphene supercapacitors.

    Science.gov (United States)

    Polat, Emre O; Kocabas, Coskun

    2013-01-01

    Optical modulators are commonly used in communication and information technology to control intensity, phase, or polarization of light. Electro-optic, electroabsorption, and acousto-optic modulators based on semiconductors and compound semiconductors have been used to control the intensity of light. Because of gate tunable optical properties, graphene introduces new potentials for optical modulators. The operation wavelength of graphene-based modulators, however, is limited to infrared wavelengths due to inefficient gating schemes. Here, we report a broadband optical modulator based on graphene supercapacitors formed by graphene electrodes and electrolyte medium. The transparent supercapacitor structure allows us to modulate optical transmission over a broad range of wavelengths from 450 nm to 2 μm under ambient conditions. We also provide various device geometries including multilayer graphene electrodes and reflection type device geometries that provide modulation of 35%. The graphene supercapacitor structure together with the high-modulation efficiency can enable various active devices ranging from plasmonics to optoelectronics.

  16. Stretchable Transparent Electrode Arrays for Simultaneous Electrical and Optical Interrogation of Neural Circuits in Vivo.

    Science.gov (United States)

    Zhang, Jing; Liu, Xiaojun; Xu, Wenjing; Luo, Wenhan; Li, Ming; Chu, Fangbing; Xu, Lu; Cao, Anyuan; Guan, Jisong; Tang, Shiming; Duan, Xiaojie

    2018-04-09

    Recent developments of transparent electrode arrays provide a unique capability for simultaneous optical and electrical interrogation of neural circuits in the brain. However, none of these electrode arrays possess the stretchability highly desired for interfacing with mechanically active neural systems, such as the brain under injury, the spinal cord, and the peripheral nervous system (PNS). Here, we report a stretchable transparent electrode array from carbon nanotube (CNT) web-like thin films that retains excellent electrochemical performance and broad-band optical transparency under stretching and is highly durable under cyclic stretching deformation. We show that the CNT electrodes record well-defined neuronal response signals with negligible light-induced artifacts from cortical surfaces under optogenetic stimulation. Simultaneous two-photon calcium imaging through the transparent CNT electrodes from cortical surfaces of GCaMP-expressing mice with epilepsy shows individual activated neurons in brain regions from which the concurrent electrical recording is taken, thus providing complementary cellular information in addition to the high-temporal-resolution electrical recording. Notably, the studies on rats show that the CNT electrodes remain operational during and after brain contusion that involves the rapid deformation of both the electrode array and brain tissue. This enables real-time, continuous electrophysiological monitoring of cortical activity under traumatic brain injury. These results highlight the potential application of the stretchable transparent CNT electrode arrays in combining electrical and optical modalities to study neural circuits, especially under mechanically active conditions, which could potentially provide important new insights into the local circuit dynamics of the spinal cord and PNS as well as the mechanism underlying traumatic injuries of the nervous system.

  17. Optical find of hypersonic surface acoustic waves in bulk transparent materials

    Science.gov (United States)

    Jiménez Riobóo, Rafael J.; Sánchez-Sánchez, Alberto; Prieto, Carlos

    2016-07-01

    It is shown that direct information from surface acoustic waves (SAWs) of bulk transparent materials can be obtained by using Brillouin light scattering (BLS). The study of surface phonons by means of an optical spectroscopy such as BLS has been historically constrained to nontransparent and highly reflecting bulk and film samples or even to very thin films deposited on reflecting substrates. Probably due to its low signal and to the narrow window in experimental conditions, it was assumed for years that bulk transparent samples were not suited for Brillouin spectroscopy in order to get information on SAWs, negating this optical technique in the search for SAW properties. The reported experiments on transparent glasses and single crystals (cubic MgO and trigonal sapphire) prove that there is no intrinsic physical reason not to collect SAW propagation velocity data from transparent bulk samples and opens a challenge to apply the Brillouin spectroscopy in a wider scenario to obtain direct information, in a nondestructive and contactless way, about SAWs in bulk materials.

  18. Optically and thermally controlled terahertz metamaterial via transition between direct and indirect electromagnetically induced transparency

    Directory of Open Access Journals (Sweden)

    Jiawei Sui

    2014-12-01

    Full Text Available This passage presents a design of tunable terahertz metamaterials via transition between indirect and direct electromagnetically induced transparency (EIT effects by changing semiconductor InSb’s properties to terahertz wave under optical and thermal stimuli. Mechanical model and its electrical circuit model are utilized in analytically calculating maximum transmission of transparency window. Simulated results show consistency with the analytical expressions. The results show that the metamaterials hold 98.4% modulation depth at 189 GHz between 300 K, σInSb =256000 S/m, and 80 K, σInSb =0.0162 S/m conditions , 1360 ps recovery time of the excited electrons in InSb under optical stimulus at 300 K mainly considering the direct EIT effect, and minimum bandwidth 1 GHz.

  19. Electrically Conductive, Optically Transparent Polymer/Carbon Nanotube Composites and Process for Preparation Thereof

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  20. Optically and thermally controlled terahertz metamaterial via transition between direct and indirect electromagnetically induced transparency

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Jiawei, E-mail: suijiaweiat163@163.com; Feng, Ls [Department of Instrumental Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China)

    2014-12-15

    This passage presents a design of tunable terahertz metamaterials via transition between indirect and direct electromagnetically induced transparency (EIT) effects by changing semiconductor InSb’s properties to terahertz wave under optical and thermal stimuli. Mechanical model and its electrical circuit model are utilized in analytically calculating maximum transmission of transparency window. Simulated results show consistency with the analytical expressions. The results show that the metamaterials hold 98.4% modulation depth at 189 GHz between 300 K, σ{sub InSb} =256000 S/m, and 80 K, σ{sub InSb} =0.0162 S/m conditions , 1360 ps recovery time of the excited electrons in InSb under optical stimulus at 300 K mainly considering the direct EIT effect, and minimum bandwidth 1 GHz.

  1. Tuning optical properties of transparent conducting barium stannate by dimensional reduction

    Directory of Open Access Journals (Sweden)

    Yuwei Li

    2015-01-01

    Full Text Available We report calculations of the electronic structure and optical properties of doped n-type perovskite BaSnO3 and layered perovskites. While doped BaSnO3 retains its transparency for energies below the valence to conduction band onset, the doped layered compounds exhibit below band edge optical conductivity due to transitions from the lowest conduction band. This gives absorption in the visible for Ba2SnO4. Thus, it is important to minimize this phase in transparent conducting oxide (TCO films. Ba3Sn2O7 and Ba4Sn3O10 have strong transitions only in the red and infrared, respectively. Thus, there may be opportunities for using these as wavelength filtering TCO.

  2. TRANSPARENT CONCRETE

    OpenAIRE

    Sandeep Sharma*, Dr. O.P. Reddy

    2017-01-01

    Transparent concrete is the new type of concrete introduced in todays world which carries special property of light transmitting due to presence of light Optical fibres. Which is also known as translucent concrete or light transmitting concrete, it is achieved by replacing coarse aggregates with transparent alternate materials (Optical fibres). The binding material in transparent concrete may be able to transmit light by using clear resins the concrete mix. The concrete used in industry in pr...

  3. Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.

    Science.gov (United States)

    Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad

    2018-04-18

    Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.

  4. Optical haze of randomly arranged silver nanowire transparent conductive films with wide range of nanowire diameters

    Directory of Open Access Journals (Sweden)

    M. Marus

    2018-03-01

    Full Text Available The effect of the diameter of randomly arranged silver nanowires on the optical haze of silver nanowire transparent conductive films was studied. Proposed simulation model behaved similarly with the experimental results, and was used to theoretically study the optical haze of silver nanowires with diameters in the broad range from 30 nm and above. Our results show that a thickening of silver nanowires from 30 to 100 nm results in the increase of the optical haze up to 8 times, while from 100 to 500 nm the optical haze increases only up to 1.38. Moreover, silver nanowires with diameter of 500 nm possess up to 5% lower optical haze and 5% higher transmittance than 100 nm thick silver nanowires for the same 10-100 Ohm/sq sheet resistance range. Further thickening of AgNWs can match the low haze of 30 nm thick AgNWs, but at higher transmittance. The results obtained from this work allow deeper analysis of the silver nanowire transparent conductive films from the perspective of the diameter of nanowires for various optoelectronic devices.

  5. Towards transparent all-optical label-swapped networks: 40 Gbit/s ultra-fast dynamic wavelength routing using integrated devices

    DEFF Research Database (Denmark)

    Seoane, Jorge; Holm-Nielsen, Pablo Villanueva; Jeppesen, Palle

    2006-01-01

    All-optical routing of 40 Gbit/s 1.6 ns packets is demonstrated employing integrated devices based on SOA-MZIs. The scheme allows wavelength transparent operation and sub-nanosecond dynamic wavelength selection for future packet/label switched networks....

  6. A transparent Pyrex μ-reactor for combined in situ optical characterization and photocatalytic reactivity measurements

    DEFF Research Database (Denmark)

    Dionigi, Fabio; Nielsen, Morten Godtfred; Pedersen, Thomas

    2013-01-01

    A new Pyrex-based μ-reactor for photocatalytic and optical characterization experiments is presented. The reactor chamber and gas channels are microfabricated in a thin poly-silicon coated Pyrex chip that is sealed with a Pyrex lid by anodic bonding. The device is transparent to light in the UV...

  7. Spin-Based Photonics via Electromagnetically Induced Transparency

    Science.gov (United States)

    2006-11-01

    DISTWISUTIOM STATEr -ME T A Approved for Public Release Distribution Unlimited Final Technical Report Spin-Based Photonics via Electromagnetically...N00014-03-1-0827 Summary Research efforts have focused on the development and implementation of electromagnetically-induced transparency (EIT) from... Research associated, University of Arizona Rolf Binder, Co-PI, University of Arizona J. Furdyna, Co-PI, University of Notre Dame Hailin Wang, Pl, University

  8. Transparent Electrodes Based on Silver Nanowire Networks: From Physical Considerations towards Device Integration.

    Science.gov (United States)

    Bellet, Daniel; Lagrange, Mélanie; Sannicolo, Thomas; Aghazadehchors, Sara; Nguyen, Viet Huong; Langley, Daniel P; Muñoz-Rojas, David; Jiménez, Carmen; Bréchet, Yves; Nguyen, Ngoc Duy

    2017-05-24

    The past few years have seen a considerable amount of research devoted to nanostructured transparent conducting materials (TCM), which play a pivotal role in many modern devices such as solar cells, flexible light-emitting devices, touch screens, electromagnetic devices, and flexible transparent thin film heaters. Currently, the most commonly used TCM for such applications (ITO: Indium Tin oxide) suffers from two major drawbacks: brittleness and indium scarcity. Among emerging transparent electrodes, silver nanowire (AgNW) networks appear to be a promising substitute to ITO since such electrically percolating networks exhibit excellent properties with sheet resistance lower than 10 Ω/sq and optical transparency of 90%, fulfilling the requirements of most applications. In addition, AgNW networks also exhibit very good mechanical flexibility. The fabrication of these electrodes involves low-temperature processing steps and scalable methods, thus making them appropriate for future use as low-cost transparent electrodes in flexible electronic devices. This contribution aims to briefly present the main properties of AgNW based transparent electrodes as well as some considerations relating to their efficient integration in devices. The influence of network density, nanowire sizes, and post treatments on the properties of AgNW networks will also be evaluated. In addition to a general overview of AgNW networks, we focus on two important aspects: (i) network instabilities as well as an efficient Atomic Layer Deposition (ALD) coating which clearly enhances AgNW network stability and (ii) modelling to better understand the physical properties of these networks.

  9. Optically transparent and durable Al2O3 coatings for harsh environments by ultra short pulsed laser deposition

    Science.gov (United States)

    Korhonen, Hannu; Syväluoto, Aki; Leskinen, Jari T. T.; Lappalainen, Reijo

    2018-01-01

    Nowadays, an environmental protection is needed for a number of optical applications in conditions quickly impairing the clarity of optical surfaces. Abrasion resistant optical coatings applied onto plastics are usually based on alumina or polysiloxane technology. In many applications transparent glasses and ceramics need a combination of abrasive and chemically resistant shielding or other protective solutions like coatings. In this study, we intended to test our hypothesis that clear and pore free alumina coating can be uniformly distributed on glass prisms by ultra short pulsed laser deposition (USPLD) technique to protect the sensitive surfaces against abrasives. Abrasive wear tests were carried out by the use of SiC emery paper using specified standard procedures. After the wear tests the measured transparencies of coated prisms turned out to be close those of the prisms before coating. The coating on sensitive surfaces consistently displayed enhanced wear resistance exhibiting still high quality, even after severe wear testing. Furthermore, the coating modified the surface properties towards hydrophobic nature in contrast to untreated prisms, which became very hydrophilic especially due to wear.

  10. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

    2015-08-31

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

  11. Biocompatible Optically Transparent MEMS for Micromechanical Stimulation and Multimodal Imaging of Living Cells.

    Science.gov (United States)

    Fior, Raffaella; Kwok, Jeanie; Malfatti, Francesca; Sbaizero, Orfeo; Lal, Ratnesh

    2015-08-01

    Cells and tissues in our body are continuously subjected to mechanical stress. Mechanical stimuli, such as tensile and contractile forces, and shear stress, elicit cellular responses, including gene and protein alterations that determine key behaviors, including proliferation, differentiation, migration, and adhesion. Several tools and techniques have been developed to study these mechanobiological phenomena, including micro-electro-mechanical systems (MEMS). MEMS provide a platform for nano-to-microscale mechanical stimulation of biological samples and quantitative analysis of their biomechanical responses. However, current devices are limited in their capability to perform single cell micromechanical stimulations as well as correlating their structural phenotype by imaging techniques simultaneously. In this study, a biocompatible and optically transparent MEMS for single cell mechanobiological studies is reported. A silicon nitride microfabricated device is designed to perform uniaxial tensile deformation of single cells and tissue. Optical transparency and open architecture of the device allows coupling of the MEMS to structural and biophysical assays, including optical microscopy techniques and atomic force microscopy (AFM). We demonstrate the design, fabrication, testing, biocompatibility and multimodal imaging with optical and AFM techniques, providing a proof-of-concept for a multimodal MEMS. The integrated multimodal system would allow simultaneous controlled mechanical stimulation of single cells and correlate cellular response.

  12. Graphene Transparent Conductive Electrodes

    Data.gov (United States)

    National Aeronautics and Space Administration — As an atomic layer of graphite, graphene has ultrahigh optical transparency and superior electron mobility. We plan to develop graphene transparent conductive...

  13. Transparent electrode designs based on optimal nano-patterning of metallic films

    KAUST Repository

    Catrysse, Peter B.

    2010-09-10

    Transparent conductive electrodes are critical to the operation of optoelectronic devices, such as photovoltaic cells and light emitting diodes. Effective electrodes need to combine excellent electrical and optical properties. Metal oxides, such as indium tin oxide, are commonly used. There is substantial interest in replacing them, however, motivated by practical problems and recent discoveries regarding the optics of nano-patterned metals. When designing nano-patterned metallic films for use as electrodes, one needs to account for both optical and electrical properties. In general, it is insufficient to optimize nano-structured films based upon optical properties alone, since structural variations will also affect the electrical properties. In this work, we investigate the need for simultaneous optical and electrical performance by analyzing the optical properties of a class of nano-patterned metallic electrodes that is obtained by a constant-sheet-resistance transformation. Within such a class the electrical and optical properties can be separated, i.e., the sheet resistance can be kept constant and the transmittance can be optimized independently. For simple one-dimensional periodic patterns with constant sheet-resistance, we find a transmission maximum (polarization-averaged) when the metal sections are narrow (< 40 nm, ~ 10% metal fill-factor) and tall (> 100 nm). Our design carries over to more complex two-dimensional (2D) patterns. This is significant as there are no previous reports regarding numerical studies on the optical and electrical properties of 2D nano-patterns in the context of electrode design.

  14. ZnO as dielectric for optically transparent non-volatile memory

    International Nuclear Information System (INIS)

    Salim, N. Tjitra; Aw, K.C.; Gao, W.; Wright, Bryon E.

    2009-01-01

    This paper discusses the application of a DC sputtered ZnO thin film as a dielectric in an optically transparent non-volatile memory. The main motivation for using ZnO as a dielectric is due to its optical transparency and mechanical flexibility. We have established the relationship between the electrical resistivity (ρ) and the activation energy (E a ) of the electron transport in the conduction band of the ZnO film. The ρ of 2 x 10 4 -5 x 10 7 Ω-cm corresponds to E a of 0.36-0.76 eV, respectively. The k-value and optical band-gap for films sputtered with Ar:O 2 ratio of 4:1 are 53 ± 3.6 and 3.23 eV, respectively. In this paper, the basic charge storage element for a non-volatile memory is a triple layer dielectric structure in which a 50 nm thick ZnO film is sandwiched between two layers of methyl silsesquioxane sol-gel dielectric of varying thickness. A pronounced clockwise capacitance-voltage (C-V) hysteresis was observed with a memory window of 6 V. The integration with a solution-processable pentacene, 13,6-N-Sulfinylacetamodipentacene resulted in an optically transparent organic field effect transistor non-volatile memory (OFET-NVM). We have demonstrated that this OFET-NVM can be electrically programmed and erased at low voltage (± 10 V) with a threshold voltage shift of 4.0 V.

  15. Poisson-Spot Intensity Reduction with a Partially-Transparent Petal-Shaped Optical Mask

    Science.gov (United States)

    Shiri, Shahram; Wasylkiwskyj, Wasyl

    2013-01-01

    The presence of Poisson's spot, also known as the spot of Arago, formed along the optical axis in the geometrical shadow behind an obstruction, has been known since the 18th century. The presence of this spot can best be described as the consequence of constructive interference of light waves diffracted on the edge of the obstruction where its central position can··be determined by the symmetry of the object More recently, the elimination of this spot has received attention in the fields of particle physics, high-energy lasers, astronomy and lithography. In this paper, we introduce a novel, partially transparent petaled mask shape that suppresses the bright spot by up to 10 orders of magnitude in intensity, with powerful applications to many of the above fields. The optimization technique formulated in this design can identify mask shapes having partial transparency only near the petal tips.

  16. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    International Nuclear Information System (INIS)

    Aytug, Tolga; Simpson, John T; Lupini, Andrew R; Trejo, Rosa M; Jellison, Gerald E; Ivanov, Ilia N; Pennycook, Stephen J; Hillesheim, Daniel A; Winter, Kyle O; Christen, David K; Hunter, Scott R; Allen Haynes, J

    2013-01-01

    We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie–Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military. (paper)

  17. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    Science.gov (United States)

    Aytug, Tolga; Simpson, John T.; Lupini, Andrew R.; Trejo, Rosa M.; Jellison, Gerald E.; Ivanov, Ilia N.; Pennycook, Stephen J.; Hillesheim, Daniel A.; Winter, Kyle O.; Christen, David K.; Hunter, Scott R.; Haynes, J. Allen

    2013-08-01

    We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

  18. Transparent thin films of indium tin oxide: Morphology-optical investigations, inter dependence analyzes

    Science.gov (United States)

    Prepelita, P.; Filipescu, M.; Stavarache, I.; Garoi, F.; Craciun, D.

    2017-12-01

    Using a fast and eco-friendly deposition method, ITO thin films with different thicknesses (0.5 μm-0.7 μm) were deposited on glass substrates by radio frequency magnetron sputtering technique. A comparative analysis of these oxide films was then carried out. AFM investigations showed that the deposited films were smooth, uniform and having a surface roughness smaller than 10 nm. X-ray diffraction investigations showed that all samples were polycrystalline and the grain sizes of the films, corresponding to (222) cubic reflection, were found to increase with the increasing film thickness. The optical properties, evaluated by UV-VIS-NIR (190-3000 nm) spectrophotometer, evidenced that the obtained thin films were highly transparent, with a transmission coefficient between 90 and 96%, depending on the film thickness. Various methods (Swanepoel and Drude) were employed to appreciate the optimal behaviour of transparent oxide films, in determining the dielectric optical parameters and refractive index dispersion for ITO films exhibiting interference patterns in the optical transmission spectra. The electrical conductivity also increased as the film thickness increased.

  19. Transparent and flexible photodetectors based on CH3NH3PbI3 perovskite nanoparticles

    Science.gov (United States)

    Jeon, Young Pyo; Woo, Sung Jun; Kim, Tae Whan

    2018-03-01

    Transparent and flexible photodetectors (PDs) based on CH3NH3PbI3 perovskite nanoparticles (NPs) were fabricated by using co-evaporation of methyl ammonium iodide and lead iodide. X-ray diffraction patterns and high-resolution transmission electron microscopy images demonstrated the formation of perovskite NPs. The optical transmittance of the perovskite NPs/glass was above 80% over the entire range of visible wavelengths, indicative of high transparency. The PDs based on CH3NH3PbI3 perovskite NPs were sensitive to a broad range of visible light from 450 to 650 nm. The currents in the PDs under exposure to red, green, and blue light-emitting diodes were enhanced to 5, 10, and 20 times that of the PD in the dark, respectively. The rise and the decay times of the PDs were 50 and 120 μs. The current in the perovskite NP PD on a polyethylene terephthalate substrate was enhanced by approximately 69% when the NP PD was exposed to a blue LED emitting at a wavelength of 459 nm. Despite multiple bending, the transparent and flexible PDs based on methyl ammonium iodide and lead iodide NPs showed reproducibility and high stability in performance.

  20. Preparation and characterization of transparent PMMA-cellulose-based nanocomposites.

    Science.gov (United States)

    Kiziltas, Esra Erbas; Kiziltas, Alper; Bollin, Shannon C; Gardner, Douglas J

    2015-01-01

    Nanocomposites of polymethylmethacrylate (PMMA) and cellulose were made by a solution casting method using acetone as the solvent. The nanofiber networks were prepared using three different types of cellulose nanofibers: (i) nanofibrillated cellulose (NFC), (ii) cellulose nanocrystals (CNC) and (iii) bacterial cellulose from nata de coca (NDC). The loading of cellulose nanofibrils in the PMMA varied between 0.25 and 0.5 wt%. The mechanical properties of the composites were evaluated using a dynamic mechanical thermal analyzer (DMTA). The flexural modulus of the nanocomposites reinforced with NDC at the 0.5 wt% loading level increased 23% compared to that of pure PMMA. The NFC composite also exhibited a slightly increased flexural strength around 60 MPa while PMMA had a flexural strength of 57 MPa. The addition of NDC increased the storage modulus (11%) compared to neat PMMA at room temperature while the storage modulus of PPMA/CNC nanocomposite containing 0.25 and 0.5 wt% cellulose increased about 46% and 260% to that of the pure PMMA at the glass transition temperature, respectively. Thermogravimetric analysis (TGA) indicated that there was no significant change in thermal stability of the composites. The UV-vis transmittance of the CNF nanocomposites decreased by 9% and 27% with the addition of 0.25 wt% CNC and NDC, respectively. This work is intended to spur research and development activity for application of CNF reinforced PMMA nanocomposites in applications such as: packaging, flexible screens, optically transparent films and light-weight transparent materials for ballistic protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Investigation of ITO free transparent conducting polymer based electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Vikas; Sapna,; Sachdev, Kanupriya [Department of Physics, Malaviya National Institute of Technology Jaipur, JLN Marg, Jaipur-India-302017 (India)

    2016-05-23

    The last few decades have seen a significant improvement in organic semiconductor technology related to solar cell, light emitting diode and display panels. The material and structure of the transparent electrode is one of the major concerns for superior performance of devices such as OPV, OLED, touch screen and LCD display. Commonly used ITO is now restricted due to scarcity of indium, its poor mechanical properties and rigidity, and mismatch of energy levels with the active layer. Nowadays DMD (dielectric-metal-dielectric) structure is one of the prominent candidates as alternatives to ITO based electrode. We have used solution based spin coated polymer layer as the dielectric layer with silver thin film embedded in between to make a polymer-metal-polymer (PMP) structure for TCE applications. The PMP structure shows low resistivity (2.3 x 10{sup −4}Ω-cm), high carrier concentration (2.9 x 10{sup 21} cm{sup −3}) and moderate transparency. The multilayer PMP structure is characterized with XRD, AFM and Hall measurement to prove its suitability for opto-electronic device applications.

  2. Magnetically Induced Optical Transparency on a Forbidden Transition in Strontium for Cavity-Enhanced Spectroscopy

    Science.gov (United States)

    Winchester, Matthew N.; Norcia, Matthew A.; Cline, Julia R. K.; Thompson, James K.

    2017-06-01

    In this Letter we realize a narrow spectroscopic feature using a technique that we refer to as magnetically induced optical transparency. A cold ensemble of 88Sr atoms interacts with a single mode of a high-finesse optical cavity via the 7.5 kHz linewidth, spin forbidden 1S0 to 3P1 transition. By applying a magnetic field that shifts two excited state Zeeman levels, we open a transmission window through the cavity where the collective vacuum Rabi splitting due to a single level would create destructive interference for probe transmission. The spectroscopic feature approaches the atomic transition linewidth, which is much narrower than the cavity linewidth, and is highly immune to the reference cavity length fluctuations that limit current state-of-the-art laser frequency stability.

  3. Optical transparency and electrical conductivity of nonstoichiometric ultrathin InxOy films

    International Nuclear Information System (INIS)

    Joseph, Shay; Berger, Shlomo

    2011-01-01

    The effect of thickness and composition on the electrical conductivity and optical transparency, mainly in the infrared, of ultrathin In x O y films was studied. In x O y films 35-470 A thick with oxygen atomic fractions of ∼0.3 and ∼0.5 were prepared via dc magnetron sputtering. All films were polycrystalline, consisting of only the cubic bixbiyte phase of In 2 O 3 . The average grain size of the films increased from 30 to 95 nm as the film thickness increased. The weak dependence of the electrical conductivity on the frequency and the low activation energies for conduction, a few hundredths of an eV, provided an indication that free band conduction was the primary electrical conduction mechanism in the case of all ultrathin In x O y films. It was found that introducing a high degree of nonstoichiometry in the form of oxygen deficiency did not help improve the electrical conductivity, since not all vacancies contributed two free electrons for conduction and due to impurity scattering. The optical nature of these films, studied mainly by ellipsometry, was found to be dependent on the film's composition and thickness. In the infrared, the dielectric function of all In x O y films was consistent with the Drude model, inferring that the transparency loss in this region was a result of free charge carriers. In the visible however, In x O y films under 170 A, which had an oxygen atomic fraction of ∼0.5, were modeled by extending the Drude model to the shorter wavelengths. Films over 170 A, with the same composition, were modeled using the Cauchy dispersion model, meaning that no absorption was measured. These results indicate that, optically, under specific compositions, ultrathin In x O y films undergo a transition from metalliclike behavior to dielectric behavior with increasing film thickness. Using a figure of merit approach, it was determined that a nonstoichiometric 230 A thick In x O y film, with an oxygen atomic fraction of ∼0.3, had the best combination

  4. Transparent and stretchable strain sensors based on metal nanowire microgrids for human motion monitoring.

    Science.gov (United States)

    Cho, Ji Hwan; Ha, Sung-Hun; Kim, Jong-Man

    2018-04-02

    Optical transparency is increasingly considered as one of the most important characteristics required in advanced stretchable strain sensors for application in body-attachable systems. In this paper, we present an entirely solution-processed fabrication route to highly transparent and stretchable resistive strain sensors based on silver nanowire microgrids (AgNW-MGs). The AgNW-MG strain sensors are readily prepared by patterning the AgNWs on a stretchable substrate into a MG geometry via a mesh-template-assisted contact-transfer printing. The MG has a unique architecture comprising the AgNWs and can be stretched to ε = 35%, with high gauge factors of ∼6.9 for ε = 0%-30% and ∼41.1 for ε = 30%-35%. The sensor also shows a high optical transmittance of 77.1% ± 1.5% (at 550 nm) and stably maintains the remarkable optical performance even at high strains. In addition, the sensor responses are found to be highly reversible with negligible hysteresis and are reliable even under repetitive stretching-releasing cycles (1000 cycles at ε = 10%). The practicality of the AgNW-MG strain sensor is confirmed by successfully monitoring a wide range of human motions in real time after firmly laminating the device onto various body parts.

  5. Transparent and stretchable strain sensors based on metal nanowire microgrids for human motion monitoring

    Science.gov (United States)

    Cho, Ji Hwan; Ha, Sung-Hun; Kim, Jong-Man

    2018-04-01

    Optical transparency is increasingly considered as one of the most important characteristics required in advanced stretchable strain sensors for application in body-attachable systems. In this paper, we present an entirely solution-processed fabrication route to highly transparent and stretchable resistive strain sensors based on silver nanowire microgrids (AgNW-MGs). The AgNW-MG strain sensors are readily prepared by patterning the AgNWs on a stretchable substrate into a MG geometry via a mesh-template-assisted contact-transfer printing. The MG has a unique architecture comprising the AgNWs and can be stretched to ɛ = 35%, with high gauge factors of ˜6.9 for ɛ = 0%-30% and ˜41.1 for ɛ = 30%-35%. The sensor also shows a high optical transmittance of 77.1% ± 1.5% (at 550 nm) and stably maintains the remarkable optical performance even at high strains. In addition, the sensor responses are found to be highly reversible with negligible hysteresis and are reliable even under repetitive stretching-releasing cycles (1000 cycles at ɛ = 10%). The practicality of the AgNW-MG strain sensor is confirmed by successfully monitoring a wide range of human motions in real time after firmly laminating the device onto various body parts.

  6. Dynamically controllable plasmon induced transparency based on hybrid metal-graphene metamaterials.

    Science.gov (United States)

    Yan, Xicheng; Wang, Tao; Xiao, Shuyuan; Liu, Tingting; Hou, Haowen; Cheng, Le; Jiang, Xiaoyun

    2017-10-24

    Novel hybrid metal-graphene metamaterials featuring dynamically controllable single, double and multiple plasmon induced transparency (PIT) windows are numerically explored in the terahertz (THz) regime. The designed plasmonic metamaterials composed of a strip and a ring with graphene integration generate a novel PIT window. Once the ring is divided into pairs of asymmetrical arcs, double PIT windows both with the spectral contrast ratio 100% are obtained, where one originates from the destructive interference between bright-dark modes, and the other is based on the interaction of bright-bright modes. Just because the double PIT windows are induced by two different mechanisms, the continuously controllable conductivity and damping of graphene are employed to appropriately interpret the high tunability in double transparency peaks at the resonant frequency, respectively. Moreover, multiple PIT windows can be achieved by introducing an additional bright mode to form the other bright-bright modes coupling. At the PIT transparent windows, the dispersions undergo tremendous modifications and the group delays reach up to 43 ps, 22 ps, and 25 ps, correspondingly. Our results suggest the existence of strong interaction between the monolayer graphene layer and metal-based resonant plasmonic metamaterials, which may hold widely applications in filters, modulators, switching, sensors and optical buffers.

  7. Fully patterned and low temperature transparent ZnO-based inverters

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Heredia, G. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Department of Materials Science and Engineering, University of Texas at Dallas (United States); Mejia, I.; Rivas-Aguilar, M.E.; Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas (United States); Martinez-Landeros, V.H. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Department of Materials Science and Engineering, University of Texas at Dallas (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Unidad Monterrey, México (Mexico); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas (United States)

    2013-10-31

    The fabrication and characterization of transparent logic inverters based on zinc oxide (ZnO) thin film transistors (TFTs) is reported. The inverters are fabricated using standard photolithographic techniques on glass substrates, and the entire fabrication process temperature is maintained < 100 °C, which render the devices suitable for flexible and transparent electronics applications. Pulsed laser deposition is used to deposit aluminum-doped zinc oxide and ZnO as electrode and active semiconductor materials, respectively. Electrical characterization for individual TFTs demonstrate mobilities of ∼ 10 cm{sup 2}/V-s, threshold voltages of 6 V, sub-threshold slopes of 630 mV/decade and I{sub ON}/I{sub OFF} ratios of 5 × 10{sup 6}. Films characterized by UV-Vis showed optical transmission > 80% in the visible spectrum. The inverters are analyzed with AC input signals at frequencies of 100 and 500 Hz. The AC response shows an average rise and fall time transitions of 0.65 and 0.44 ms, respectively. Measured inverters delay is in the order of 0.21 ms. - Highlights: • Logic inverters based on zinc oxide thin film transistors. • Inverters fabricated using temperatures below 100 °C and standard photolithography. • Transparent aluminum-doped zinc oxide as gate, drain and source electrodes. • Devices with total transmittance in the visible range above 80%. • AC inverter response up to 500 Hz.

  8. Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges

    International Nuclear Information System (INIS)

    Lothongkam, Chaiyaporn

    2014-01-01

    statistical analysis based on the 2-parameter Weibull distribution function. The investigations revealed that the virgin translucent silicone rubber has a large elastic region with an acceptable plastic deformation and also provides an AC 50 Hz dielectric strength of approximately 24 kV/mm for 0.5 mm thickness. These values enable considering the tested translucent silicone as replacement material for an opaque elastomer that is currently used for a rubber stress cone of HV cable accessories.. Unfortunately, its optical transmittance is poor compared to optically clear transparent silicone rubbers. On the other hand, the mechanical properties of virgin transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the AC dielectric strength values in either 28 kV/mm or 29 kV/mm for 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide a positive impact on the ultimate elongation of silicone rubbers. Hence, the elongation at break of virgin transparent silicone rubbers must be improved before they can be used as insulating material for a rubber stress cone. In addition, the influence of mechanical tensile stress on the dielectric strength of the virgin translucent silicone rubber was investigated. The results show that mechanical tensile stress does not negatively influence on dielectric strength of such silicone rubber, so it can be well-operated under combined electrical and mechanical stresses. Beside the improvement of optical PD detection performance in the translucent silicone insulation materials, the influence of fluorescent dye's modification was investigated. The results indicate that the commercially available fluorescent dyes of 0.02 wt. % mixed into the translucent silicone polymer do not negatively influence on the E b value of such silicone

  9. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  10. Manufacturing process scale-up of optical grade transparent spinel ceramic at ArmorLine Corporation

    Science.gov (United States)

    Spilman, Joseph; Voyles, John; Nick, Joseph; Shaffer, Lawrence

    2013-06-01

    While transparent Spinel ceramic's mechanical and optical characteristics are ideal for many Ultraviolet (UV), visible, Short-Wave Infrared (SWIR), Mid-Wave Infrared (MWIR), and multispectral sensor window applications, commercial adoption of the material has been hampered because the material has historically been available in relatively small sizes (one square foot per window or less), low volumes, unreliable supply, and with unreliable quality. Recent efforts, most notably by Technology Assessment and Transfer (TA and T), have scaled-up manufacturing processes and demonstrated the capability to produce larger windows on the order of two square feet, but with limited output not suitable for production type programs. ArmorLine Corporation licensed the hot-pressed Spinel manufacturing know-how of TA and T in 2009 with the goal of building the world's first dedicated full-scale Spinel production facility, enabling the supply of a reliable and sufficient volume of large Transparent Armor and Optical Grade Spinel plates. With over $20 million of private investment by J.F. Lehman and Company, ArmorLine has installed and commissioned the largest vacuum hot press in the world, the largest high-temperature/high-pressure hot isostatic press in the world, and supporting manufacturing processes within 75,000 square feet of manufacturing space. ArmorLine's equipment is capable of producing window blanks as large as 50" x 30" and the facility is capable of producing substantial volumes of material with its Lean configuration and 24/7 operation. Initial production capability was achieved in 2012. ArmorLine will discuss the challenges that were encountered during scale-up of the manufacturing processes, ArmorLine Optical Grade Spinel optical performance, and provide an overview of the facility and its capabilities.

  11. Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses

    KAUST Repository

    Mansour, Ahmed

    2015-07-22

    The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant cost in optical transmission. We demonstrate doping of few layers graphene with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine leads to air-stable transparent conducting electrodes with five-fold improvement of sheet resistance reaching at the cost of only 2-3% loss of optical transmission. The remarkably low tradeoff in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the workfunction by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics and beyond.

  12. Optical and electrical properties of structured multilayer with tunable transparency rate

    International Nuclear Information System (INIS)

    Bou, Adrien; Torchio, Philippe; Barakel, Damien; Guillou, Aurélie; Thoulon, Pierre-Yves; Ricci, Marc; Ayachi, Boubakeur

    2015-01-01

    An experimental study has been carried out on structured multilayer with tunable transparency rate. In this paper, we present the optical and electrical characterization of an oxide | metal | oxide structured electrode manufactured by e-beam deposition and patterned by a lift-off process. The obtained samples are made of grids with different geometrical parameters that lead to varying surface coverage rate on glass. The electrical and optical parameters of SnO x |Ag|SnO x grids are investigated to determine the efficiency, sustainability and limitations of such structures. A linear relationship between the transmittance of the electrodes and the increase of the surface coverage rate is obtained. Coupled to an optimization process, we are able to define a high transparency in a chosen spectral range. Electrical results show a relative stability of the resistivity from 2.9   ×   10   −  4  Ω.cm for an as-grown electrode to 5.6   ×   10   −  4  Ω.cm for a structured electrode with a surface coverage rate of 59%. (paper)

  13. Carbon Nanotube Networks Reinforced by Silver Nanowires with Improved Optical Transparency and Conductivity

    Science.gov (United States)

    Martine, Patricia; Fakhimi, Azin; Lin, Ling; Jurewicz, Izabela; Dalton, Alan; Zakhidov, Anvar A.; Baughman, Ray H.

    2015-03-01

    We have fabricated highly transparent and conductive free-standing nanocomposite thin film electrodes by adding silver nanowires (AgNWs) to dry-spun Multiwall Carbon Nanotube (MWNT) aerogels. This nanocomposite exhibits desirable properties such as high optical transmittance, excellent flexibility and enhanced electrical conductivity. The incorporation of the AgNWs to the MWNT aerogels was accomplished by using a spray coating method. The optical transparency and sheet resistance of the nanocomposite was tuned by adjusting the concentration of AgNWs, back pressure and nozzle distance of the spray gun to the MWNT aerogel during deposition. As the solvent evaporated, the aerogel MWNT bundles densified via surface tension which caused the MWNT bundles to collapse. This adjustable process was responsible in forming well defined apertures that increased the nanocomposite's transmittance up to 90 percent. Via AgNWs percolation and random interconnections between separate MWNT bundles in the aerogel matrix, the sheet resistance decreased from 1 K ohm/sq to less than 100 ohm/sq. Alan G. MacDiarmid NanoTech Institute

  14. Transparent plastic scintillators for neutron detection based on lithium salicylate

    Science.gov (United States)

    Mabe, Andrew N.; Glenn, Andrew M.; Carman, M. Leslie; Zaitseva, Natalia P.; Payne, Stephen A.

    2016-01-01

    Transparent plastic scintillators with pulse shape discrimination containing 6Li salicylate have been synthesized by bulk polymerization with a maximum 6Li loading of 0.40 wt%. Photoluminescence and scintillation responses to gamma-rays and neutrons are reported herein. Plastics containing 6Li salicylate exhibit higher light yields and permit a higher loading of 6Li as compared to previously reported plastics based on lithium 3-phenylsalicylate. However, pulse shape discrimination performance is reduced in lithium salicylate plastics due to the requirement of adding more nonaromatic monomers to the polymer matrix as compared to those based on lithium 3-phenylsalicylate. Reduction in light yield and pulse shape discrimination performance in lithium-loaded plastics as compared to pulse shape discrimination plastics without lithium is interpreted in terms of energy transfer interference by the aromatic lithium salts.

  15. Analogue of electromagnetically-induced-transparency based on graphene nanotube waveguide

    International Nuclear Information System (INIS)

    Wei, Buzheng; Jian, Shuisheng

    2017-01-01

    A graphene-based nanotube waveguide system is proposed and designed to realize the analogue of electromagnetically-induced-transparency. The two nanotubes act as side coupled cavity rings which can be treated as the bright and dark resonators. By mimicking the quantum nonlinear optical interference, the light at resonant frequency makes the opaque system transparent. Conveniently, the working transparency window can be dynamically controlled by shifting the Fermi energy level of graphene without refabricating the device. Furthermore, the shape of the transmission spectrum can be tuned either by adjusting the waveguide coupling distance or by the cavity ring coupling distance. If the ring radius gets bigger, higher order of modes are excited in the dark resonator consequently. Meaningfully, the light travels at resonant frequency can be efficiently slowed down and the highest group delay reaches 25 ps. In the end, some concerns about the practical realization of such device are discussed. The structure may find potential applications in nano technology or light storage field. (paper)

  16. Analogue of electromagnetically-induced-transparency based on graphene nanotube waveguide

    Science.gov (United States)

    Wei, Buzheng; Jian, Shuisheng

    2017-09-01

    A graphene-based nanotube waveguide system is proposed and designed to realize the analogue of electromagnetically-induced-transparency. The two nanotubes act as side coupled cavity rings which can be treated as the bright and dark resonators. By mimicking the quantum nonlinear optical interference, the light at resonant frequency makes the opaque system transparent. Conveniently, the working transparency window can be dynamically controlled by shifting the Fermi energy level of graphene without refabricating the device. Furthermore, the shape of the transmission spectrum can be tuned either by adjusting the waveguide coupling distance or by the cavity ring coupling distance. If the ring radius gets bigger, higher order of modes are excited in the dark resonator consequently. Meaningfully, the light travels at resonant frequency can be efficiently slowed down and the highest group delay reaches 25 ps. In the end, some concerns about the practical realization of such device are discussed. The structure may find potential applications in nano technology or light storage field.

  17. UV shielding with visible transparency based properties of poly (styrene-co-acrylonitrile)/Ag doped ZnO nanocomposite

    Science.gov (United States)

    Singh, Rajender; Verma, Karan; Singh, Tejbir; Barman, P. B.; Sharma, Dheeraj

    2018-02-01

    Development of ultraviolet (UV) shielding with visible transparency based thermoplastic polymer nanocomposite (PNs) presents an important requisite in terms of their efficiency and cost. Present study contributed for the same approach by dispersion of Ag doped ZnO nanoparticles upto 10 wt% in poly (styrene-co-acrylonitrile) matrix by insitu emulsion polymerization method. The crystal and chemical structure of PNs has been analyzed by x-ray diffraction (XRD) and fourier infrared spectrometer (FTIR) techniques. The morphological and elemental information of synthesized nanomaterial has been studied by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) technique. The optical properties of PNs has been studied by UV-visible spectroscopy technique. The incorporation of nanoparticles in polymer matrix absorb the complete UV light with visible transparency. The present reported polymer nanocomposite (PNs) have tuned refractive index with UV blocking and visible transparency based properties which can serve as a viable alternative as compared to related conventional materials.

  18. Healable, Transparent, Room-Temperature Electronic Sensors Based on Carbon Nanotube Network-Coated Polyelectrolyte Multilayers.

    Science.gov (United States)

    Bai, Shouli; Sun, Chaozheng; Yan, Hong; Sun, Xiaoming; Zhang, Han; Luo, Liang; Lei, Xiaodong; Wan, Pengbo; Chen, Xiaodong

    2015-11-18

    Transparent and conductive film based electronics have attracted substantial research interest in various wearable and integrated display devices in recent years. The breakdown of transparent electronics prompts the development of transparent electronics integrated with healability. A healable transparent chemical gas sensor device is assembled from layer-by-layer-assembled transparent healable polyelectrolyte multilayer films by developing effective methods to cast transparent carbon nanotube (CNT) networks on healable substrates. The healable CNT network-containing film with transparency and superior network structures on self-healing substrate is obtained by the lateral movement of the underlying self-healing layer to bring the separated areas of the CNT layer back into contact. The as-prepared healable transparent film is assembled into healable transparent chemical gas sensor device for flexible, healable gas sensing at room temperature, due to the 1D confined network structure, relatively high carrier mobility, and large surface-to-volume ratio. The healable transparent chemical gas sensor demonstrates excellent sensing performance, robust healability, reliable flexibility, and good transparency, providing promising opportunities for developing flexible, healable transparent optoelectronic devices with the reduced raw material consumption, decreased maintenance costs, improved lifetime, and robust functional reliability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Flexible Transparent Supercapacitors Based on Hierarchical Nanocomposite Films.

    Science.gov (United States)

    Chen, Fanhong; Wan, Pengbo; Xu, Haijun; Sun, Xiaoming

    2017-05-31

    Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.

  20. Bromination of graphene: a new route to making high performance transparent conducting electrodes with low optical losses

    KAUST Repository

    Mansour, Ahmed

    2015-09-03

    The high optical transmittance, electrical conductivity, flexibility and chemical stability of graphene have triggered great interest in its application as a transparent conducting electrode material and as a potential replacement for indium doped tin oxide. However, currently available large scale production methods such as chemical vapor deposition produce polycrystalline graphene, and require additional transfer process which further introduces defects and impurities resulting in a significant increase in its sheet resistance. Doping of graphene with foreign atoms has been a popular route for reducing its sheet resistance which typically comes at a significant loss in optical transmission. Herein, we report the successful bromine doping of graphene resulting in air-stable transparent conducting electrodes with up to 80% reduction of sheet resistance reaching ~180 Ω/ at the cost of 2-3% loss of optical transmission in case of few layer graphene and 0.8% in case of single layer graphene. The remarkably low tradeoff in optical transparency leads to the highest enhancements in figure of merit reported thus far. Furthermore, our results show a controlled increase in the workfunction up to 0.3 eV with the bromine content. These results should help pave the way for further development of graphene as potentially a highly transparent substitute to other transparent conducting electrodes in optoelectronic devices.

  1. Transparent Flexible Multifunctional Nanostructured Architectures for Non-optical Readout, Proximity, and Pressure Sensing.

    Science.gov (United States)

    Kulkarni, Mohit Rameshchandra; John, Rohit Abraham; Rajput, Mayank; Tiwari, Naveen; Yantara, Natalia; Nguyen, Anh Chien; Mathews, Nripan

    2017-05-03

    Electronic skins need to be versatile and able to detect multiple inputs beyond simple pressure and touch while having attributes of transparency and facile manufacturability. Herein, we demonstrate a versatile nanostructured transparent sensor capable of detecting wide range of pressures and proximity as well as novel nonoptical detection of printed patterns. The architecture and fabrication processes are straightforward and show robustness to repeated cycling and testing. The sensor displays good sensitivity and stability from 30 Pa to 5 kPa without the use of microstructuration and is conformal and sensitive to be utilized as a wrist-based heart-rate monitor. Highly sensitive proximity detection is shown from a distance of 9 cm. Finally, a unique nonoptical pattern recognition dependent on the difference in the dielectric constant between ink and paper is also demonstrated, indicating the multifunctionality of this simple architecture.

  2. Preparation and RGB upconversion optic properties of transparent anti-counterfeiting films.

    Science.gov (United States)

    Yao, Weijing; Tian, Qingyong; Liu, Jun; Xue, Qingwen; Li, Mengxiao; Liu, Li; Lu, Qiang; Wu, Wei

    2017-10-26

    Advanced anti-counterfeiting labels have aroused an intensive interest in packaging industry to avoid the serious issue of counterfeit. However, the preparation and cost of the existing labels associated with the drawbacks, including the complex and high-cost equipment, limit the protection of the authenticity of goods. Herein, we developed a series of anti-counterfeiting labels based on multicolor upconversion micro-particles (UCMPs) inks via straightforward and low-cost solutions, including spin-coating, stamping and screen printing. The UCMPs were synthesized through a facile hydrothermal process and displayed tunable red (R), green (G) and blue (B) color by doping different lanthanide ions, which are Er 3+ /Tm 3+ , Yb 3+ /Er 3+ and Yb 3+ /Tm 3+ in NaYF 4 hosts, respectively. The optimal UCMPs inks were deposited on a flexible polyethylene terephthalate (PET) substrate to obtain transparent anti-counterfeiting labels possessing higher transmittance, stronger upconversion fluorescence intensity and good photostability. Under ambient conditions, the patterns and films were transparent, but could exhibit multicolor light under 980 nm laser excitation. They can be used as anti-counterfeiting labels for die-cutting packages to further elevate the security of goods. The tunable and designable transparent anti-counterfeiting labels based on RGB UCMPs inks exhibit the merits of low-cost, easy-manufacture and versatility, underlying the practical application in the field of anti-counterfeiting.

  3. Two transparent optical sensors for the positioning of detectors using a reference laser beam

    International Nuclear Information System (INIS)

    Barriere, J.Ch.; Blumenfeld, H.; Bourdinaud, M.; Cloue, O.; Guyot, C.; Molinie, F.; Ponsot, P.; Saudemont, J.C.; Schuller, J.P.; Schune, Ph.; Sube, S.

    1999-01-01

    We have developed two different optical systems in order to position detectors with respect to a reference laser beam. The first system, a telescope, permits the absolute positioning of an element with respect to a reference laser beam. The resolution is of the order of 10 μm in translation and 50 μrad in rotation. It is highly transparent (-90%) permitting several elements to be aligned. A calibration procedure has also been studied and is currently being tested in order to obtain an absolute alignment information. The second system is a highly transparent (95%) two dimensional position sensor which allows the accurate positioning (below 20 μm) of several (up to ten) elements to which each sensor is attached, transversally to a laser beam used as a reference straight line. The present useful area of the first sensor is 20 x 20 mm 2 and is 15 x 15 mm 2 for the second. In both case it can be further increased to meet the experiment's requirement. (authors)

  4. Structural, optical and electrical characterization of ITO, ITO/Ag and ITO/Ni transparent conductive electrodes

    International Nuclear Information System (INIS)

    Ali, Ahmad Hadi; Shuhaimi, Ahmad; Hassan, Zainuriah

    2014-01-01

    We report on the transparent conductive oxides (TCO) characteristics based on the indium tin oxides (ITO) and ITO/metal thin layer as an electrode for optoelectronics device applications. ITO, ITO/Ag and ITO/Ni were deposited on Si and glass substrate by thermal evaporator and radio frequency (RF) magnetron sputtering at room temperature. Post deposition annealing was performed on the samples in air at moderate temperature of 500 °C and 600 °C. The structural, optical and electrical properties of the ITO and ITO/metal were characterized using X-ray diffraction (XRD), UV–Vis spectrophotometer, Hall effect measurement system and atomic force microscope (AFM). The XRD spectrum reveals significant polycrystalline peaks of ITO (2 2 2) and Ag (1 1 1) after post annealing process. The post annealing also improves the visible light transmittance and electrical resistivity of the samples. Figure of merit (FOM) of the ITO, ITO/Ag and ITO/Ni were determined as 5.5 × 10 −3 Ω −1 , 8.4 × 10 −3 Ω −1 and 3.0 × 10 −5 Ω −1 , respectively. The results show that the post annealed ITO with Ag intermediate layer improved the efficiency of the transparent conductive electrodes (TCE) as compared to the ITO and ITO/Ni.

  5. 3-D neurohistology of transparent tongue in health and injury with optical clearing

    Directory of Open Access Journals (Sweden)

    Tzu-En eHua

    2013-10-01

    Full Text Available Tongue receives extensive innervation to perform taste, sensory, and motor functions. Details of the tongue neuroanatomy and its plasticity in response to injury offer insights to investigate tongue neurophysiology and pathophysiology. However, due to the dispersed nature of the neural network, standard histology cannot provide a global view of the innervation. We prepared transparent mouse tongue by optical clearing to reveal the spatial features of the tongue innervation and its remodeling in injury. Immunostaining of neuronal markers, including PGP9.5 (pan-neuronal marker, calcitonin gene-related peptide (sensory nerves, tyrosine hydroxylase (sympathetic nerves, and vesicular acetylcholine transporter (cholinergic parasympathetic nerves and neuromuscular junctions, was combined with vessel painting and nuclear staining to label the tissue network and architecture. The tongue specimens were immersed in the optical-clearing solution to facilitate photon penetration for 3-dimensiontal (3-D confocal microscopy. Taking advantage of the transparent tissue, we simultaneously revealed the tongue microstructure and innervation with subcellular-level resolution. 3-D projection of the papillary neurovascular complex and taste bud innervation was used to demonstrate the spatial features of tongue mucosa and the panoramic imaging approach. In the tongue injury induced by 4-nitroquinoline 1-oxide administration in the drinking water, we observed neural tissue remodeling in response to the changes of mucosal and muscular structures. Neural networks and the neuromuscular junctions were both found rearranged at the peri-lesional region, suggesting the nerve-lesion interactions in response to injury. Overall, this new tongue histological approach provides a useful tool for 3-D imaging of neural tissues to better characterize their roles with the mucosal and muscular components in health and disease.

  6. Analysis of Local Financial Management Transparency Based on Websites on Local Government in Java

    Directory of Open Access Journals (Sweden)

    Anissa Adriana

    2018-03-01

    Full Text Available The aim of this research is to analyze financial management transparency of local governments in Java using scoring and rating. The financial management transparency of the local governments is scored based on presentation of local financial information uploaded on each local government’s official website in Jawa in the fiscal years 2016.This research is a qualitative research with the object of research is all local government in Java. Data analysis in two levels, namely the transparency of local government financial management and identification of local government characteristics based on transparency of financial management. Data analysis in two levels, namely the transparency of local government financial management and identification of local government characteristics based on transparency of financial management. The results show that the Special Capital Region of Jakarta obtained the highest transparency index, at 58, 02% whereas Madiun Regency received the lowest transparency index, at 3, 40%. The average transparency index in Jawa for the fiscal years 2016 was still low, at only 19, 59%.The conclusion of this research is that Java regional governments consider the transparency of local financial management using less important websites because it is considered as a better thing not delivered to the public.

  7. High performance and low cost transparent electrodes based on ultrathin Cu layer.

    Science.gov (United States)

    Ebner, David; Bauch, Martin; Dimopoulos, Theodoros

    2017-04-17

    Transparent electrodes based on an ultrathin Cu layer, embedded between two dielectrics, are optimized by simulations and experiments. Different dielectrics are screened in transfer matrix simulations for maximizing the broad-band transmittance. Based on this, sputtered electrodes were developed with the Cu embedded between TiOX-coated glass or PET substrate and an Al-doped ZnO (AZO) top layer. It is found that, for ultrathin Cu layers, increased sputter power fosters island coalescence, leading to superior optical and electrical performance compared to previously reported Cu-based electrodes. Simulations showed that the electrode design optimized with air as ambient medium has to be adapted in the case of electrode implementation in a hybrid perovskite solar cell of inverted architecture.

  8. ZnO based transparent conductive oxide films with controlled type of conduction

    Energy Technology Data Exchange (ETDEWEB)

    Zaharescu, M., E-mail: mzaharescu@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Mihaiu, S., E-mail: smihaiu@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Toader, A. [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Atkinson, I., E-mail: irinaatkinson@yahoo.com [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Calderon-Moreno, J.; Anastasescu, M.; Nicolescu, M.; Duta, M.; Gartner, M. [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Vojisavljevic, K.; Malic, B. [Institute Jožef Stefan, Ljubljana (Slovenia); Ivanov, V.A.; Zaretskaya, E.P. [State Scientific and Production Association “Scientific-Practical Materials Research Center of the National Academy of Science Belarus, P. Brovska str.19, 220072, Minsk (Belarus)

    2014-11-28

    The transparent conductive oxide films with controlled type of conduction are of great importance and their preparation is intensively studied. In our work, the preparation of such films based on doped ZnO was realized in order to achieve controlled type of conduction and high concentration of the charge carriers. Sol–gel method was used for films preparation and several dopants were tested (Sn, Li, Ni). Multilayer deposition was performed on several substrates: SiO{sub 2}/Si wafers, silica-soda-lime and/or silica glasses. The structural and morphological characterization of the obtained films were done by scanning electron microscopy, X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy and atomic force microscopy respectively, while spectroscopic ellipsometry and transmittance measurements were done for determination of optical properties. The selected samples with the best structural, morphological and optical properties were subjected to electrical measurement (Hall and Seebeck effect). In all studied cases, samples with good adherence and homogeneous morphology as well as monophasic wurtzite type structure were obtained. The optical constants (refractive index and extinction coefficient) were calculated from spectroscopic ellipsometry data using Cauchy model. Films with n- or p-type conduction were obtained depending on the composition, number of deposition and thermal treatment temperature. - Highlights: • Transparent conductive ZnO based thin films were prepared by the sol–gel method. • Controlled type of conduction is obtained in (Sn, Li) doped and Li-Ni co-doped ZnO films. • Hall and Seebeck measurements proved the p-type conductivity for Li-Ni co-doped ZnO films. • The p-type conductivity was maintained even after 4-months of storage. • Influence of dopant- and substrate-type on the ZnO films properties was established.

  9. Silver nanowire-based transparent, flexible, and conductive thin film

    Directory of Open Access Journals (Sweden)

    Liu Cai-Hong

    2011-01-01

    Full Text Available Abstract The fabrication of transparent, conductive, and uniform silver nanowire films using the scalable rod-coating technique is described in this study. Properties of the transparent conductive thin films are investigated, as well as the approaches to improve the performance of transparent silver nanowire electrodes. It is found that silver nanowires are oxidized during the coating process. Incubation in hydrogen chloride (HCl vapor can eliminate oxidized surface, and consequently, reduce largely the resistivity of silver nanowire thin films. After HCl treatment, 175 Ω/sq and approximately 75% transmittance are achieved. The sheet resistivity drops remarkably with the rise of the film thickness or with the decrease of transparency. The thin film electrodes also demonstrated excellent flexible stability, showing < 2% resistance change after over 100 bending cycles.

  10. Highly conductive and transparent carbon nanotube-based electrodes for ultrathin and stretchable organic solar cells

    International Nuclear Information System (INIS)

    Fan Qingxia; Zhang Qiang; Zhou Wenbin; Yang Feng; Zhang Nan; Xiao Shiqi; Gu Xiaogang; Xiao Zhuojian; Chen Huiliang; Wang Yanchun; Liu Huaping; Zhou Weiya

    2017-01-01

    In this work, we have presented a freestanding and flexible CNT-based film with sheet resistance of 60 Ω/□ and transmittance of 82% treated by nitric acid and chloroauric acid in sequence. Based on modified CNT film as a transparent electrode, we have demonstrated an ultrathin, flexible organic solar cell (OSC) fabricated on 2.5-μm PET substrate. The efficiency of OSC, combined with a composite film of poly (3-hexylthiophene) (P3HT) and phenyl-C61 butyric acid methyl ester (PCBM) as an active layer and with a thin layer of methanol soluble biuret inserted between the photoactive layer and the cathode, can be up to 2.74% which is approximate to that of the reference solar cell fabricated with ITO-coated glass (2.93%). Incorporating the as-fabricated ITO-free OSC with pre-stretched elastomer, 50% compressive deformation can apply to the solar cells. The results show that the as-prepared CNT-based hybrid film with outstanding electrical and optical properties could serve as a promising transparent electrode for low cost, flexible and stretchable OSCs, which will broaden the applications of OSC and generate more solar power than it now does. (paper)

  11. Transparent plastic scintillators for neutron detection based on lithium salicylate

    Energy Technology Data Exchange (ETDEWEB)

    Mabe, Andrew N., E-mail: mabe2@llnl.gov; Glenn, Andrew M.; Carman, M. Leslie; Zaitseva, Natalia P.; Payne, Stephen A.

    2016-01-11

    Transparent plastic scintillators with pulse shape discrimination containing {sup 6}Li salicylate have been synthesized by bulk polymerization with a maximum {sup 6}Li loading of 0.40 wt%. Photoluminescence and scintillation responses to gamma-rays and neutrons are reported herein. Plastics containing {sup 6}Li salicylate exhibit higher light yields and permit a higher loading of {sup 6}Li as compared to previously reported plastics based on lithium 3-phenylsalicylate. However, pulse shape discrimination performance is reduced in lithium salicylate plastics due to the requirement of adding more nonaromatic monomers to the polymer matrix as compared to those based on lithium 3-phenylsalicylate. Reduction in light yield and pulse shape discrimination performance in lithium-loaded plastics as compared to pulse shape discrimination plastics without lithium is interpreted in terms of energy transfer interference by the aromatic lithium salts. - Highlights: • Plastic scintillator with 0.4% {sup 6}Li loading is reported using lithium salicylate. • Influence of lithium salts on the scintillation mechanism is explored. • New lithium-loaded scintillator provides improved light yield and reduced cost.

  12. Transparent and Flexible Surface-Enhanced Raman Scattering (SERS) Sensors Based on Gold Nanostar Arrays Embedded in Silicon Rubber Film.

    Science.gov (United States)

    Park, Seungyoung; Lee, Jiwon; Ko, Hyunhyub

    2017-12-20

    Integration of surface-enhanced Raman scattering (SERS) sensors onto transparent and flexible substrates enables lightweight and deformable SERS sensors which can be wrapped or swabbed on various nonplanar surfaces for the efficient collection and detection of analytes on various surfaces. However, the development of transparent and flexible SERS substrates with high sensitivity is still challenging. Here, we demonstrate a transparent and flexible SERS substrate with high sensitivity based on a polydimethylsiloxane (PDMS) film embedded with gold nanostar (GNS) assemblies. The flexible SERS substrates enable conformal coverage on arbitrary surfaces, and the optical transparency allows light interaction with the underlying contact surface, thereby providing highly sensitive detection of analytes adsorbed on arbitrary metallic and dielectric surfaces which otherwise do not provide any noticeable Raman signals of analytes. In particular, when the flexible SERS substrates are covered onto metallic surfaces, the SERS enhancement is greatly improved because of the additional plasmon couplings between GNS and metal film. We achieve the detection capability of a trace amount of benzenethiol (10 -8 M) and enormous SERS enhancement factor (∼1.9 × 10 8 ) for flexible SERS substrates on Ag film. In addition, because of the embedded structure of GNS monolayers within the PDMS film, SERS sensors maintain the high sensitivity even after mechanical deformations of stretching, bending, and torsion for 100 cycles. The transparent and flexible SERS substrates introduced in this study are applicable to various SERS sensing applications on nonplanar surfaces, which are not achievable for hard SERS substrates.

  13. Structural, optical and electrochemical properties of F-doped vanadium oxide transparent semiconducting thin films

    Science.gov (United States)

    Mousavi, M.; Khorrami, Gh. H.; Kompany, A.; Yazdi, Sh. Tabatabai

    2017-12-01

    In this study, F-doped vanadium oxide thin films with doping levels up to 60 at % were prepared by spray pyrolysis method on glass substrates. To measure the electrochemical properties, some films were deposited on fluorine-tin oxide coated glass substrates. The effect of F-doping on the structural, electrical, optical and electrochemical properties of vanadium oxide samples was investigated. The X-ray diffractographs analysis has shown that all the samples grow in tetragonal β-V2O5 phase structure with the preferred orientation of [200]. The intensity of (200) peak belonging to β-V2O5 phase was strongest in the undoped vanadium oxide film. The scanning electron microscopy images show that the samples have nanorod- and nanobelt-shaped structure. The size of the nanobelts in the F-doped vanadium oxide films is smaller than that in the pure sample and the width of the nanobelts increases from 30 to 70 nm with F concentration. With increasing F-doping level from 10 to 60 at %, the resistivity, the transparency and the optical band gap decrease from 111 to 20 Ω cm, 70 to 50% and 2.4 to 2.36 eV, respectively. The cyclic voltammogram (CV) results show that the undoped sample has the most extensive CV and by increasing F-doping level from 20 to 60 at %, the area of the CV is expanded. The anodic and cathodic peaks in F-doped samples are stronger.

  14. Defects and properties of cadmium oxide based transparent conductors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Kin Man, E-mail: kinmanyu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Detert, D. M.; Dubon, O. D. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Chen, Guibin [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department and Jiangsu Key Laboratory for Chemistry of Low Dimensional Materials, Huaiyin Normal University, Jiangsu 223300 (China); Zhu, Wei [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics and The Center for Physical Experiments, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu, Chaoping [Department of Physics and Materials Science, City University of Hong Kong, Kowloon (Hong Kong); Grankowska, S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Institute of Experimental Physics (IEP UW), Warsaw University, Warsaw (Poland); Hsu, L. [Department of Postsecondary Teaching and Learning, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Walukiewicz, Wladek [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-05-14

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (<200 °C), sputter deposition tends to trap both oxygen vacancies and compensating defects in the CdO film resulting in materials with high electron concentration of ∼2 × 10{sup 20}/cm{sup 3} and mobility in the range of 40–100 cm{sup 2}/V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O{sub 2} partial pressure in the sputter gas mixture results in films with resistivity from ∼4 × 10{sup −4} to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 10{sup 21 }cm{sup −3} and electron mobility higher than 120 cm{sup 2}/V s can be achieved. Thermal annealing of doped CdO films in N{sub 2} ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ∼1 eV and that the mobility of sputtered deposited CdO is limited

  15. Defects and properties of cadmium oxide based transparent conductors

    Science.gov (United States)

    Yu, Kin Man; Detert, D. M.; Chen, Guibin; Zhu, Wei; Liu, Chaoping; Grankowska, S.; Hsu, L.; Dubon, O. D.; Walukiewicz, Wladek

    2016-05-01

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (concentration of ˜2 × 1020/cm3 and mobility in the range of 40-100 cm2/V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O2 partial pressure in the sputter gas mixture results in films with resistivity from ˜4 × 10-4 to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 1021 cm-3 and electron mobility higher than 120 cm2/V s can be achieved. Thermal annealing of doped CdO films in N2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ˜1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of ˜5-6 × 1020/cm3. The calculations offer an insight into understanding of the effects of defects on electrical properties of undoped and doped CdO and offer a potential to use similar methods to

  16. Defects and properties of cadmium oxide based transparent conductors

    International Nuclear Information System (INIS)

    Yu, Kin Man; Detert, D. M.; Dubon, O. D.; Chen, Guibin; Zhu, Wei; Liu, Chaoping; Grankowska, S.; Hsu, L.; Walukiewicz, Wladek

    2016-01-01

    Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (<200 °C), sputter deposition tends to trap both oxygen vacancies and compensating defects in the CdO film resulting in materials with high electron concentration of ∼2 × 10 20 /cm 3 and mobility in the range of 40–100 cm 2 /V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O 2 partial pressure in the sputter gas mixture results in films with resistivity from ∼4 × 10 −4 to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 10 21  cm −3 and electron mobility higher than 120 cm 2 /V s can be achieved. Thermal annealing of doped CdO films in N 2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ∼1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of

  17. Versatile and Tunable Transparent Conducting Electrodes Based on Doped Graphene

    KAUST Repository

    Mansour, Ahmed E.

    2016-11-25

    The continued growth of the optoelectronics industry and the emergence of wearable and flexible electronics will continue to place an ever increasing pressure on replacing ITO, the most widely used transparent conducting electrode (TCE). Among the various candidates, graphene shows the highest optical transmittance in addition to promising electrical transport properties. The currently available large-scale synthesis routes of graphene result in polycrystalline samples rife with grain boundaries and other defects which limit its transport properties. Chemical doping of graphene is a viable route towards increasing its conductivity and tuning its work function. However, dopants are typically present at the surface of the graphene sheet, making them highly susceptible to degradation in environmental conditions. Few-layers graphene (FLG) is a more resilient form of graphene exhibiting higher conductivity and performance stability under stretching and bending as contrasted to single-layer graphene. In addition FLG presents the advantage of being amenable bulk doping by intercalation. Herein, we explore non-covalent doping routes of CVD FLG, such as surface doping, intercalation and combination thereof, through in-depth and systematic characterization of the electrical transport properties and energy levels shifts. The intercalation of FLG with Br2 and FeCl3 is demonstrated, showing the highest improvements of the figure of merit of TCEs of any doping scheme, which results from up to a five-fold increase in conductivity while maintaining the transmittance within 3% of that for the pristine value. Importantly the intercalation yields TCEs that are air-stable, due to encapsulation of the intercalant in the bulk of FLG. Surface doping with novel solution-processed metal-organic molecular species (n- and p-type) is demonstrated with an unprecedented range of work function modulation, resulting from electron transfer and the formation of molecular surface dipoles. However

  18. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The proposed interferometer set-up is quite suitable for performing optical test studies on phase (transparent) objects in real-time. Recording schemes for the formation of holographic optical elements and the related technique for the realization of the interferometer set-up along with the experimental results have been ...

  19. Electromagnetically induced transparency control in terahertz metasurfaces based on bright-bright mode coupling

    Science.gov (United States)

    Yahiaoui, R.; Burrow, J. A.; Mekonen, S. M.; Sarangan, A.; Mathews, J.; Agha, I.; Searles, T. A.

    2018-04-01

    We demonstrate a classical analog of electromagnetically induced transparency (EIT) in a highly flexible planar terahertz metamaterial (MM) comprised of three-gap split-ring resonators. The keys to achieve EIT in this system are the frequency detuning and hybridization processes between two bright modes coexisting in the same unit cell as opposed to bright-dark modes. We present experimental verification of two bright modes coupling for a terahertz EIT-MM in the context of numerical results and theoretical analysis based on a coupled Lorentz oscillator model. In addition, a hybrid variation of the EIT-MM is proposed and implemented numerically to dynamically tune the EIT window by incorporating photosensitive silicon pads in the split gap region of the resonators. As a result, this hybrid MM enables the active optical control of a transition from the on state (EIT mode) to the off state (dipole mode).

  20. Experimental demonstration of a simple, optically transparent, add/drop multiplexer at 2.5 Gb/s without local optical source

    NARCIS (Netherlands)

    Rijnders, J.M.; van Bochove, A.C.; van Deventer, M.O.

    1996-01-01

    We present a novel add/drop multiplexer and experimentally demonstrate its operation at 2.5 Gb/s. No local laser is needed since the wavelength- and modulation format transparent 'add' is accomplished by using optical switches, delay lines and the 'dropped' input. Applications are found in flexible,

  1. Fabrication, optical and scintillation properties of transparent YAG:Ce ceramics

    Science.gov (United States)

    Osipov, V. V.; Ishchenko, A. V.; Shitov, V. A.; Maksimov, R. N.; Lukyashin, K. E.; Platonov, V. V.; Orlov, A. N.; Osipov, S. N.; Yagodin, V. V.; Viktorov, L. V.; Shulgin, B. V.

    2017-09-01

    Highly transparent YAG:Ce ceramics (transmission of 72-82% for 2-mm-thick samples in 550-900 nm wavelength range) were fabricated by solid-state reactive sintering using a mixture of Ce2xY2-2xO3 (x = 0.001, 0.01, 0.03, and 0.05) and Al2O3 nanopowders synthesized by laser ablation with an additional round of pre-calcining before compaction. The synthesized YAG:Ce ceramic materials showed intense luminescence with a maximum at 525-545 nm. The measured absolute light yields of the synthesized YAG:Ce ceramics were 18-21 photon/MeV for 1-5 at.% Ce and 5 photon/MeV for 0.1 at.% Ce. The energy resolutions of the fabricated thin ceramic samples (2 mm) under 662 keV gamma ray were measured to be 10-15%. The decay curves of scintillations consisted of two components with the decay times depending on the Ce3+ concentration. The sample doped with 5 at.% of Ce exhibited the main fast component with 26 ns decay time. The measured data was compared to that of YAG:Ce and well-known CsI:Tl single crystal scintillators. The influence of dopant concentration on the optical, luminescence and scintillation properties was discussed.

  2. Electromagnetically induced transparency and ultraslow optical solitons in a coherent atomic gas filled in a slot waveguide.

    Science.gov (United States)

    Xu, Jin; Huang, Guoxiang

    2013-02-25

    We investigate the electromagnetically induced transparency (EIT) and nonlinear pulse propagation in a Λ-type three-level atomic gas filled in a slot waveguide, in which electric field is strongly confined inside the slot of the waveguide due to the discontinuity of dielectric constant. We find that EIT effect can be greatly enhanced due to the reduction of optical-field mode volume contributed by waveguide geometry. Comparing with the atomic gases in free space, the EIT transparency window in the slot waveguide system can be much wider and deeper, and the Kerr nonlinearity of probe laser field can be much stronger. We also prove that using slot waveguide ultraslow optical solitons can be produced efficiently with extremely low generation power.

  3. Optical Sky Brightness and Transparency during the Winter Season at Dome A Antarctica from the Gattini-All-Sky Camera

    Science.gov (United States)

    Yang, Yi; Moore, Anna M.; Krisciunas, Kevin; Wang, Lifan; Ashley, Michael C. B.; Fu, Jianning; Brown, Peter J.; Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Hu, Zhongwen; Lawrence, Jon S.; Luong-Van, Daniel; Riddle, Reed L.; Shang, Zhaohui; Sims, Geoff; Storey, John W. V.; Suntzeff, Nicholas B.; Tothill, Nick; Travouillon, Tony; Yang, Huigen; Yang, Ji; Zhou, Xu; Zhu, Zhenxi

    2017-07-01

    The summit of the Antarctic plateau, Dome A, is proving to be an excellent site for optical, near-infrared, and terahertz astronomical observations. Gattini is a wide-field camera installed on the PLATO instrument module as part of the Chinese-led traverse to Dome A in 2009 January. We present here the measurements of sky brightness with the Gattini ultra-large field of view (90^\\circ × 90^\\circ ) in the photometric B-, V-, and R-bands; cloud cover statistics measured during the 2009 winter season; and an estimate of the sky transparency. A cumulative probability distribution indicates that the darkest 10% of the nights at Dome A have sky brightness of S B = 22.98, S V = 21.86, and S R = 21.68 mag arcsec-2. These values were obtained during the year 2009 with minimum aurora, and they are comparable to the faintest sky brightness at Maunakea and the best sites of northern Chile. Since every filter includes strong auroral lines that effectively contaminate the sky brightness measurements, for instruments working around the auroral lines, either with custom filters or with high spectral resolution instruments, these values could be easily obtained on a more routine basis. In addition, we present example light curves for bright targets to emphasize the unprecedented observational window function available from this ground-based site. These light curves will be published in a future paper.

  4. Mesoscopic Rydberg Gate Based on Electromagnetically Induced Transparency

    International Nuclear Information System (INIS)

    Mueller, M.; Lesanovsky, I.; Zoller, P.; Weimer, H.; Buechler, H. P.

    2009-01-01

    We demonstrate theoretically a parallelized C-NOT gate which allows us to entangle a mesoscopic ensemble of atoms with a single control atom in a single step, with high fidelity and on a microsecond time scale. Our scheme relies on the strong and long-ranged interaction between Rydberg atoms triggering electromagnetically induced transparency. By this we can robustly implement a conditional transfer of all ensemble atoms between two logical states, depending on the state of the control atom. We outline a many-body interferometer which allows a comparison of two many-body quantum states by performing a measurement of the control atom.

  5. Enhanced optical, electrical, and mechanical characteristics of ZnO/Ag grids/ZnO flexible transparent electrodes

    Science.gov (United States)

    Wang, Chen-Tao; Ting, Chu-Chi; Kao, Po-Ching; Li, Shan-Rong; Chu, Sheng-Yuan

    2017-08-01

    This study demonstrates well-designed tri-layer flexible transparent conducting electrodes (TCEs), whose structure is ZnO (20 nm)/Ag grids (4, 6, 8, 10 nm)/ZnO (20 nm) (ZAZ), fabricated via thermal deposition. The optical, electrical, and mechanical characteristics of the proposed structure are improved compared to those of MoO3/Ag grids/MoO3 (MAM) electrodes. The transmittance at 550 nm, sheet resistance, and figure of merit of the proposed ZAZ electrodes with 6-nm silver grids are 78.58%, 9.3 Ω/square, and 9.6 × 10-3, respectively, which are better than those of MAM electrodes (66.25%, 9.7 Ω/square, and 1.6 × 10-3, respectively). It is found that the enhancement of the electrical characteristics of ZAZ can be ascribed to the improved crystallization of ZnO films. ZnO films with improved crystallization and a larger grain size can inhibit carriers from scattering at inter-grain boundaries. Based on a bending test, the strains of ZAZ electrodes under tension and compression were 0.616%, 0.633%, and those of MAM electrodes were 0.62% and 0.65%, respectively. The sheet resistance of the ZAZ structure increases significantly after 800 bending cycles, while that of the MAM structure increases significantly after only 200 bending cycles. These data indicate that ZAZ electrodes have significantly improved mechanical properties and durability compared to those of MAM electrodes in the bending test under both tensile and compressive stress. The proposed TCEs show good optical, electrical, and mechanical characteristics and have potential for application in optoelectronics.

  6. Transparent conductive graphene electrode in GaN-based ultra-violet light emitting diodes.

    Science.gov (United States)

    Kim, Byung-Jae; Mastro, Michael A; Hite, Jennifer; Eddy, Charles R; Kim, Jihyun

    2010-10-25

    We report a graphene-based transparent conductive electrode for use in ultraviolet (UV) GaN light emitting diodes (LEDs). A few-layer graphene (FLG) layer was mechanically deposited. UV light at a peak wavelength of 368 nm was successfully emitted by the FLG layer as transparent contact to p-GaN. The emission of UV light through the thin graphene layer was brighter than through the thick graphene layer. The thickness of the graphene layer was characterized by micro-Raman spectroscopy. Our results indicate that this novel graphene-based transparent conductive electrode holds great promise for use in UV optoelectronics for which conventional ITO is less transparent than graphene.

  7. A novel optically transparent RF shielding for fully integrated PET/MRI systems

    Science.gov (United States)

    Parl, C.; Kolb, A.; Schmid, A. M.; Wehrl, H. F.; Disselhorst, J. A.; Soubiran, P. D.; Stricker-Shaver, D.; Pichler, B. J.

    2017-09-01

    Preclinical imaging benefits from simultaneous acquisition of high-resolution anatomical and molecular data. Additionally, PET/MRI systems can provide functional PET and functional MRI data. To optimize PET sensitivity, we propose a system design that fully integrates the MRI coil into the PET system. This allows positioning the scintillators near the object but requires an optimized design of the MRI coil and PET detector. It further requires a new approach in realizing the radiofrequency (RF) shielding. Thus, we propose the use of an optically transparent RF shielding material between the PET scintillator and the light sensor, suppressing the interference between both systems. We evaluated two conductive foils (ITO, 9900) and a wire mesh. The PET performance was tested on a dual-layer scintillator consisting of 12  ×  12 LSO matrices, shifted by half a pitch. The pixel size was 0.9  ×  0.9 mm2 the lengths were 10.0 mm and 5.0 mm, respectively. For a light sensor, we used a 4  ×  4 SiPM array. The RF attenuation was measured from 320 kHz to 420 MHz using two pick-up coils. MRI-compatibility and shielding effect of the materials were evaluated with an MRI system. The average FWHM energy resolution at 511 keV of all 144 crystals of the layer next to the SiPM was deteriorated from 15.73  ±  0.24% to 16.32  ±  0.13%, 16.60  ±  0.25%, and 19.16  ±  0.21% by the ITO foil, 9900 foil, mesh material, respectively. The average peak-to-valley ratio of the PET detector changed from 5.77  ±  0.29 to 4.50  ±  0.39, 4.78  ±  0.48, 3.62  ±  0.16, respectively. The ITO, 9900, mesh attenuated the scintillation light by 11.3  ±  1.6%, 11.0  ±  1.8%, 54.3  ±  0.4%, respectively. To attenuate the RF from 20 MHz to 200 MHz, mesh performed better than copper. The results show that an RF shielding material that is sufficiently transparent for

  8. A new architecture as transparent electrodes for solar and IR applications based on photonic structures via soft lithography

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, Ping [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Transparent conducting electrodes with the combination of high optical transmission and good electrical conductivity are essential for solar energy harvesting and electric lighting devices. Currently, indium tin oxide (ITO) is used because ITO offers relatively high transparency (>80%) to visible light and low sheet resistance (Rs = 10 ohms/square (Ω /2)) for electrical conduction. However, ITO is costly due to limited indium reserves, and it is brittle. These disadvantages have motivated the search for other conducting electrodes with similar or better properties. There has been research on a variety of electrode structures involving carbon nanotube networks, graphene films, nanowire and nanopatterned meshes and grids. Due to their novel characteristics in light manipulation and collection, photonic crystal structures show promise for further improvement. Here, we report on a new architecture consisting of nanoscale high aspect ratio metallic photonic structures as transparent electrodes fabricated via a combination of processes. For (Au) and silver (Ag) structures, the visible light transmission can reach as high as 80%, and the sheet resistance of the structure can be as low as 3.2Ω /2. The optical transparency of the high aspect ratio metal structures at visible wavelength range is comparable to that of ITO glass, while their sheet resistance is more than 3 times lower, which indicates a much higher electrical conductivity of the metal structures. Furthermore, the high aspect ratio metal structures have very high infrared (IR) reflection (90%) for the transverse magnetic (TM) mode, which can lead to the development of fabrication of metallic structures as IR filters for heat control applications. Investigations of interdigitated structures based on the high aspect ratio metal electrodes are ongoing to study the feasibility in smart window applications in light transmission modulation.

  9. Towards Extreme Field Physics: Relativistic Optics and Particle Acceleration in the Transparent-Overdense Regime

    Science.gov (United States)

    Hegelich, B. Manuel

    2011-10-01

    A steady increase of on-target laser intensity with also increasing pulse contrast is leading to light-matter interactions of extreme laser fields with matter in new physics regimes which in turn enable a host of applications. A first example is the realization of interactions in the transperent-overdense regime (TOR), which is reached by interacting a highly relativistic (a0 >10), ultra high contrast laser pulse [1] with a solid density target, turning it transparent to the laser by the relativistic mass increase of the electrons. Thus, the interactions becomes volumetric, increasing the energy coupling from laser to plasma, facilitating a range of effects, including relativistic optics and pulse shaping, mono-energetic electron acceleration [3], highly efficient ion acceleration in the break-out afterburner regime [4], and the generation of relativistic and forward directed surface harmonics. Experiments at the LANL 130TW Trident laser facility successfully reached the TOR, and show relativistic pulse shaping beyond the Fourier limit, the acceleration of mono-energetic ~40 MeV electron bunches from solid targets, forward directed coherent relativistic high harmonic generation >1 keV Break-Out Afterburner (BOA) ion acceleration of Carbon to >1 GeV and Protons to >100 MeV. Carbon ions were accelerated with a conversion efficiency of >10% for ions >20 MeV and monoenergetic carbon ions with an energy spread of ICF diagnostics over ion fast ignition to medical physics. Furthermore, TOR targets traverse a wide range of HEDP parameter space during the interaction ranging from WDM conditions (e.g. brown dwarfs) to energy densities of ~1011 J/cm3 at peak, then dropping back to the underdense but extremely hot parameter range of gamma-ray bursts. Whereas today this regime can only be accessed on very few dedicated facilities, employing special targets and pulse cleaning technology, the next generation of laser facilities will operate in this regime by default, turning its

  10. Transparent Conductive Nanofiber Paper for Foldable Solar Cells.

    Science.gov (United States)

    Nogi, Masaya; Karakawa, Makoto; Komoda, Natsuki; Yagyu, Hitomi; Nge, Thi Thi

    2015-11-26

    Optically transparent nanofiber paper containing silver nanowires showed high electrical conductivity and maintained the high transparency, and low weight of the original transparent nanofiber paper. We demonstrated some procedures of optically transparent and electrically conductive cellulose nanofiber paper for lightweight and portable electronic devices. The nanofiber paper enhanced high conductivity without any post treatments such as heating or mechanical pressing, when cellulose nanofiber dispersions were dropped on a silver nanowire thin layer. The transparent conductive nanofiber paper showed high electrical durability in repeated folding tests, due to dual advantages of the hydrophilic affinity between cellulose and silver nanowires, and the entanglement between cellulose nanofibers and silver nanowires. Their optical transparency and electrical conductivity were as high as those of ITO glass. Therefore, using this conductive transparent paper, organic solar cells were produced that achieved a power conversion of 3.2%, which was as high as that of ITO-based solar cells.

  11. Promoting Sustainability Transparency in European Local Governments: An Empirical Analysis Based on Administrative Cultures

    Directory of Open Access Journals (Sweden)

    Andrés Navarro-Galera

    2017-03-01

    Full Text Available Nowadays, the transparency of governments with respect to the sustainability of public services is a very interesting issue for stakeholders and academics. It has led to previous research and international organisations (EU, IMF, OECD, United Nations, IFAC, G-20, World Bank to recommend promotion of the online dissemination of economic, social and environmental information. Based on previous studies about e-government and the influence of administrative cultures on governmental accountability, this paper seeks to identify political actions useful to improve the practices of transparency on economic, social and environmental sustainability in European local governments. We perform a comparative analysis of sustainability information published on the websites of 72 local governments in 10 European countries grouped into main three cultural contexts (Anglo-Saxon, Southern European and Nordic. Using international sustainability reporting guidelines, our results reveal significant differences in local government transparency in each context. The most transparent local governments are the Anglo-Saxon ones, followed by Southern European and Nordic governments. Based on individualized empirical results for each administrative style, our conclusions propose useful policy interventions to enhance sustainability transparency within each cultural tradition, such as development of legal rules on transparency and sustainability, tools to motivate local managers for online diffusion of sustainability information and analysis of information needs of stakeholders.

  12. Wave-function analysis of dynamic cancellation of ac Stark shifts in optical lattice clocks by use of pulsed Raman and electromagnetically-induced-transparency techniques

    International Nuclear Information System (INIS)

    Yoon, Tai Hyun

    2007-01-01

    We study analytically the dynamic cancellation of ac Stark shift in the recently proposed pulsed electromagnetically-induced-transparency (EIT-)Raman optical lattice clock based on the wave-function formalism. An explicit expression for the time evolution operator corresponding to the effective two-level interaction Hamiltonian has been obtained in order to explain the atomic phase shift cancellation due to the ac Stark shift induced by the time-separated laser pulses. We present how to determine an optimum value of the common detuning of the driving fields at which the atomic phase shift cancels completely with the parameters for the practical realization of the EIT-Raman optical lattice clock with alkaline-earth-metal atoms

  13. Development of Solution-Processable, Optically Transparent Polyimides with Ultra-Low Linear Coefficients of Thermal Expansion

    Directory of Open Access Journals (Sweden)

    Masatoshi Hasegawa

    2017-10-01

    the polymerizability with aromatic diamines and the CTE values of the resultant PI films. For three isomers of hydrogenated pyromellitic dianhydride, the steric structure effect on the polymerizability and the properties of the PI films is discussed. 1,2,3,4-Cyclobutanetetracarboxylic dianhydride (CBDA is a very unusual cycloaliphatic tetracarboxylic dianhydride that is suitable for reducing the CTE. For example, the PI system derived from CBDA and 2,2′-bis(trifluoromethylbenzidine (TFMB yields a colorless PI film with a relatively low CTE (21 ppm·K−1. However, this PI is insoluble in common organic solvents, which means that it is neither solution-processable nor compatible with the chemical imidization process; furthermore, the film is somewhat brittle (εb < 10%. In addition, the effect of the film preparation route on the film properties is shown to be significant. Films prepared via chemical imidization always have higher optical transparency and lower CTE values than those prepared via the conventional two-step process (i.e., precursor casting and successive thermal imidization. These results suggest that compatibility with the chemical imidization process is the key for achieving our goal. To dramatically improve the solubility in the CBDA-based PI systems, a novel amide-containing aromatic diamine (AB-TFMB, which possesses the structural features of TFMB and 4,4′-diaminobenzanilide (DABA, is proposed. The CBDA(70;6FDA(30/AB-TFMB copolymer has an ultra-low CTE (7.3 ppm·K−1, excellent optical transparency (T400 = 80.6%, yellowness index (YI = 2.5, and haze = 1.5%, a very high Tg (329 °C, sufficient ductility (εb max > 30%, and good solution-processability. Therefore, this copolymer is a promising candidate for use as a novel coating-type plastic substrate material. This paper also discusses how the target properties can be achieved without the help of cycloaliphatic monomers. Thus, elaborate molecular design allows the preparation of highly

  14. Graphene-based stretchable and transparent moisture barrier

    Science.gov (United States)

    Won, Sejeong; Van Lam, Do; Lee, Jin Young; Jung, Hyun-June; Hur, Min; Kim, Kwang-Seop; Lee, Hak-Joo; Kim, Jae-Hyun

    2018-03-01

    We propose an alumina-deposited double-layer graphene (2LG) as a transparent, scalable, and stretchable barrier against moisture; this barrier is indispensable for foldable or stretchable organic displays and electronics. Both the barrier property and stretchability were significantly enhanced through the introduction of 2LG between alumina and a polymeric substrate. 2LG with negligible polymeric residues was coated on the polymeric substrate via a scalable dry transfer method in a roll-to-roll manner; an alumina layer was deposited on the graphene via atomic layer deposition. The effect of the graphene layer on crack generation in the alumina layer was systematically studied under external strain using an in situ micro-tensile tester, and correlations between the deformation-induced defects and water vapor transmission rate were quantitatively analyzed. The enhanced stretchability of alumina-deposited 2LG originated from the interlayer sliding between the graphene layers, which resulted in the crack density of the alumina layer being reduced under external strain.

  15. Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

    Directory of Open Access Journals (Sweden)

    Nishizawa S.

    2013-08-01

    Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

  16. Layer 2 and 3 contention resolution and radio-over-fiber in OCDMA PON for transparent optical access in personal networks

    NARCIS (Netherlands)

    Huiszoon, B.; Hartog, F.T.H. den; Larrodé, M.G.; Koonen, A.M.J.

    2008-01-01

    In this paper, we analyze, for the first time, the eminent role of optical transparent networking in personal networks. We show how an optical access network mitigates many issues with respect to connectivity and mobility management. A concrete personal network user-scenario deduces requirements for

  17. Unidirectional plasmonically induced transparency behavior in a compact graphene-based waveguide

    International Nuclear Information System (INIS)

    Zhang, Zhengren; Long, Yang; Zang, Xiaofei

    2017-01-01

    A graphene-based waveguide structure is proposed to achieve a unidirectional plasmonically induced transparency (PIT) behavior. In this structure, a standing-wave cavity can be formed in the graphene waveguide by controlling the Fermi energy at a different part of the graphene. Two resonant graphene ribbons are placed at the node and antinode of the standing-wave cavity field, respectively. Its corresponding optical response coming from different incident sides show a unidirectional PIT behavior. This is because the excited bright resonant graphene ribbon located at antinode inhibits the field strength on its downstream side and causes the field redistribution on its upstream side. When the wave propagates along the sequence node-antinode, the redistribution field will excite the dark resonant graphene ribbon, such that both ribbons couple coherently and the PIT behavior appears. In contrast, when the wave propagates along the sequence antinode-node, the dark resonant graphene ribbon remains dark, and no PIT appears. Our results may benefit novel nonreciprocal devices in the future. (paper)

  18. Enhanced electrical conductivity in Xe ion irradiated CNT based transparent conducting electrode on PET substrate

    Science.gov (United States)

    Surbhi; Sharma, Vikas; Singh, Satyavir; Garg, Priyanka; Asokan, K.; Sachdev, Kanupriya

    2018-02-01

    An investigation of MWCNT-based hybrid electrode films with improved electrical conductivity after Xe ion irradiation is reported. A multilayer hybrid structure of Ag-MWCNT layer embedded in between two ZnO layers was fabricated and evaluated, pre and post 100 keV Xe ion irradiation, for their performance as Transparent Conducting Electrode in terms of their optical and electrical properties. X-ray diffraction pattern exhibits highly c-axis oriented ZnO films with a small variation in lattice parameters with an increase in ion fluence. There is no significant change in the surface roughness of these films. Raman spectra were used to confirm the presence of CNT. The pristine multilayer films exhibit an average transmittance of ˜70% in the entire visible region and the transmittance increases with Xe ion fluence. A significant enhancement in electrical conductivity post-Xe ion irradiation viz from 1.14 × 10-7 Ω-1 cm-1 (pristine) to 7.04 × 103 Ω-1 cm-1 is seen which is due to the high connectivity in the top layer with Ag-CNT hybrid layer facilitating the smooth transfer of electrons.

  19. Surface Property and Stability of Transparent Superhydrophobic Coating Based on SiO2-Polyelectrolyte Multilayer

    Directory of Open Access Journals (Sweden)

    Sunisa JINDASUWAN

    2016-05-01

    Full Text Available Artificial superhydrophobic films were deposited onto a glass slide by performing layer-by-layer deposition of 3.5 bilayers of poly(allylamine hydrochloride/ poly(acrylic acid polyelectrolyte, followed by a layer of SiO2 nanoparticles of various amounts to enhance the surface roughness and a fluorosilane to reduce the surface free energy. Higher SiO2 content incorporated into the films resulted in rougher surface and higher water contact angle. The total surface free energy determined by using the Owens-Wendt equation dramatically decreased from 31.46 mJ·m-2 for the film having the relatively flat surface to only 1.16 mJ·m-2 for the film having the highest surface roughness of 60.2 ± 1.1 nm. All the films were optically transparent and had excellent adhesion based on the peel test. Indoor and accelerated weathering tests revealed good weathering stability.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12952

  20. New transparent flexible nanopaper as ultraviolet filter based on red emissive Eu(III) nanofibrillated cellulose

    Science.gov (United States)

    Zhang, Zhao; Chang, Hui; Xue, Bailiang; Han, Qing; Lü, Xingqiang; Zhang, Sufeng; Li, Xinping; Zhu, Xunjin; Wong, Wai-kwok; Li, Kecheng

    2017-11-01

    A new kind of highly red emissive and transparent nanopapers as ultraviolet filter are produced from lanthanide complex Eu(TTA)3(H2O)2 grafted nanofibrillated cellulose (NFC) by a filtration process using a Buchner funnel. The nanopapers Eu-NFC 1-4 with different thickness (0.023 mm, 1; 0.04 mm, 2; 0.081 mm, 3 and 0.1 mm, 4) possess a fibres with dimensions of approximately 50 nm in diameter and several micrometres in length. Those nanopapers exhibit excellent ultraviolet A (UVA; 320-400 nm) filter property and high optical transmittance (>73% at wavelength of 600 nm). The presence of Eu(TTA)3(H2O)2 in Eu-NFC nanopapers can block 97% UVA (at 348 nm) light and convert it into pure red emission (CIE: x = 0.663, y = 0.333) through the efficient triplet-triplet energy transfer process. The efficient red emission can significantly improve the photo-stability of β-diketones type UVA filter. It can sustain for 10 h without decomposition under UV irradiation at 365 nm, which makes it possible to be applied in UVA filters. Moreover, its low coefficient of thermal expansion (CTE: 6.39 ppm K-1 of nanocellulose), is superior to petroleum-based materials for red organic light-emitting devices.

  1. Roll-To-Roll Printing of Meter-Scale Composite Transparent Electrodes with Optimized Mechanical and Optical Properties for Photoelectronics.

    Science.gov (United States)

    Meng, Xiangchuan; Hu, Xiaotian; Yang, Xia; Yin, Jingping; Wang, Qingxia; Huang, Liqiang; Yu, Zoukangning; Hu, Ting; Tan, Licheng; Zhou, Weihua; Chen, Yiwang

    2018-03-14

    Flexible transparent electrodes are an indispensable component for flexible optoelectronic devices. In this work, the meter-scale composite transparent electrodes (CTEs) composed of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and Ag grid/polyethylene terephthalate (PET) with optimized mechanical and optical properties are demonstrated by slot-die roll-to-roll technique with solution printing method under a low cost ($15-20 per square meter), via control of the viscosity and surface energy of PEDOT:PSS ink as well as the printing parameters. The CTEs show excellent flexibility remaining 98% of the pristine value after bending 2000 times under various bending situations, and the square resistance ( R s ) of CTEs can be reduced to 4.5-5.0 Ω/sq with an appropriate transmittance. Moreover, the optical performances, such as haze, extinction coefficient, and refractive index, are investigated, as compared with indium tin oxide/PET, which are potential for the inexpensive optoelectronic flexible devices. The CTEs could be successfully employed in polymer solar cells with different areas, showing a maximal power conversion efficiency of 8.08%.

  2. Impact of transparent electrode on photoresponse of ZnO-based phototransistor

    International Nuclear Information System (INIS)

    Lee, Seunghyup; Ahn, Seung-Eon; Jeon, Yongwoo; Ahn, Ji-Hoon; Song, Ihun; Kim, Jungwoo; Choi, Hyung; Chung, U-in; Park, Jaechul; Jeon, Sanghun; Yun, Dong-Jin

    2013-01-01

    ZnO-based photo-thin film transistors with enhanced photoresponse were developed using transparent conductive oxide contacts. Changing the electrode from opaque Mo to transparent In-Zn-O increases the photocurrent by five orders of magnitude. By changing the opacity of each source and drain electrode, we could observe how the photoresponse is affected. We deduce that the photocurrent generation mechanism is based on an energy band change due to the photon irradiation. More importantly, we reveal that the photocurrent is determined by the energy barrier of injected electrons at the interface between the source electrode and the active layer

  3. Optical, mechanical and fractographic response of transparent alumina ceramics on erbium doping

    Czech Academy of Sciences Publication Activity Database

    Drdlík, D.; Drdlíková, K.; Hadraba, Hynek; Máca, K.

    2017-01-01

    Roč. 37, č. 14 (2017), s. 4265-4270 ISSN 0955-2219 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : Alumina * Erbia * Fractography * Hardness * Transparency Subject RIV: JH - Ceramics , Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 3.411, year: 2016

  4. Fully solution-processed transparent electrodes based on silver nanowire composites for perovskite solar cells

    Science.gov (United States)

    Kim, Areum; Lee, Hongseuk; Kwon, Hyeok-Chan; Jung, Hyun Suk; Park, Nam-Gyu; Jeong, Sunho; Moon, Jooho

    2016-03-01

    We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution-processed transparent conductive electrode, Au/spiro-OMeTAD/CH3NH3PbI3 + m-Al2O3/ZnO/ITO/AgNW/ITO, exhibited a power conversion efficiency of 8.44% (comparable to that of the FTO/glass-based counterpart at 10.81%) and were stable for 30 days in ambient air. Our results demonstrate the feasibility of using AgNWs as a transparent bottom electrode in perovskite solar cells produced by a fully printable process.We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution

  5. Scalable Inkjet-Based Structural Color Printing by Molding Transparent Gratings on Multilayer Nanostructured Surfaces.

    Science.gov (United States)

    Jiang, Hao; Kaminska, Bozena

    2018-04-24

    To enable customized manufacturing of structural colors for commercial applications, up-scalable, low-cost, rapid, and versatile printing techniques are highly demanded. In this paper, we introduce a viable strategy for scaling up production of custom-input images by patterning individual structural colors on separate layers, which are then vertically stacked and recombined into full-color images. By applying this strategy on molded-ink-on-nanostructured-surface printing, we present an industry-applicable inkjet structural color printing technique termed multilayer molded-ink-on-nanostructured-surface (M-MIONS) printing, in which structural color pixels are molded on multiple layers of nanostructured surfaces. Transparent colorless titanium dioxide nanoparticles were inkjet-printed onto three separate transparent polymer substrates, and each substrate surface has one specific subwavelength grating pattern for molding the deposited nanoparticles into structural color pixels of red, green, or blue primary color. After index-matching lamination, the three layers were vertically stacked and bonded to display a color image. Each primary color can be printed into a range of different shades controlled through a half-tone process, and full colors were achieved by mixing primary colors from three layers. In our experiments, an image size as big as 10 cm by 10 cm was effortlessly achieved, and even larger images can potentially be printed on recombined grating surfaces. In one application example, the M-MIONS technique was used for printing customizable transparent color optical variable devices for protecting personalized security documents. In another example, a transparent diffractive color image printed with the M-MIONS technique was pasted onto a transparent panel for overlaying colorful information onto one's view of reality.

  6. Experimental and theoretical investigation of semiconductor optical amplifier (SOA) based all-optical switches

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup

    2004-01-01

    optical networks. The factors governing the modulation bandwidth of SOAs are determined, and schemes for reducing detrimental patterning effects are discussed. Three types of SOA-based switches are investigated numerically: so-called standardmode and differential-mode switches, and the filtering assisted......This thesis analyzes semiconductor optical amplifier (SOA) based all-optical switches experimentally and through numerical simulations. These devices are candidates for optical signal processing functionalities such as wavelength conversion, regeneration, and logic processing in future transparent...... switch. Differential -mode switches are shown to eliminate one contribution to the patterning effects, referred to as the linear patterning. This enables operation at bitrates far beyond the limit set by the carrier lifetime, but ultimately a saturation-induced patterning effect, nonlinear patterning...

  7. Color transparency

    International Nuclear Information System (INIS)

    Miller, G.A.

    1993-01-01

    Imagine shooting a beam of protons of high momentum P through an atomic nucleus. Usually the nuclear interactions prevent the particles from emerging with momentum ∼P. Further, the angular distribution of elastically scattered protons is close to the optical diffraction pattern produced by a black disk. Thus the nucleus acts as a black disk and is not transparent. However, certain high momentum transfer reactions in which a proton is knocked out of the nucleus may be completely different. Suppose that the high momentum transfer process leads to the formation of a small-size color singlet wavepacket that is ejected from the nucleus. The effects of gluons emitted by color singlet systems of closely separated quarks and gluons tend to cancel. Thus the wavepacket-nuclear interactions are suppressed, the nucleus becomes transparant and one says that color transparency CT occurs. The observation of CT also requires that the wavepacket not expand very much while it moves through the nucleus. Simple quantum mechanical formulations can assess this expansion. The creation of a small-sized wavepacket is expected in asymptotic perturbative effects. The author reviews the few experimental attempts to observe color transparency in nuclear (e,e'p) and (p,pp) reactions and interpret the data and their implications

  8. Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency.

    Science.gov (United States)

    Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

    2018-03-02

    Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO 3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

  9. Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency

    Science.gov (United States)

    Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

    2018-03-01

    Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

  10. Plasmon induced transparency and refractive index sensing in a new type of graphene-based plasmonic waveguide

    Science.gov (United States)

    Wu, Di; Tian, Jinping; Li, Lu; Yang, Rongcao

    2018-04-01

    The plasmon induced transparency (PIT) effect is investigated in a graphene-based waveguide, which is composed of a graphene bus waveguide side-coupled with a graphene strip directly and a graphene ring indirectly. Conventional numerical simulations based on finite element method (FEM) are used to study the transmission properties through optimizing the relevant parameters, and it is proved that the simulation results agree well with the analytical results. Then as one of the potential application branches of the PIT-like effect, the property of refractive index sensing with a higher sensitivity of 4160 nm/RIU is further studied. The result can help to deepen the understanding of PIT-like effect and nano sensor, and it would be also beneficial for the studies and applications of nanoscale graphene-based optical devices.

  11. Optical based tactile shear and normal load sensor

    Energy Technology Data Exchange (ETDEWEB)

    Salisbury, Curt Michael

    2015-06-09

    Various technologies described herein pertain to a tactile sensor that senses normal load and/or shear load. The tactile sensor includes a first layer and an optically transparent layer bonded together. At least a portion of the first layer is made of optically reflective material. The optically transparent layer is made of resilient material (e.g., clear silicone rubber). The tactile sensor includes light emitter/light detector pair(s), which respectively detect either normal load or shear load. Light emitter(s) emit light that traverses through the optically transparent layer and reflects off optically reflective material of the first layer, and light detector(s) detect and measure intensity of reflected light. When a normal load is applied, the optically transparent layer compresses, causing a change in reflected light intensity. When shear load is applied, a boundary between optically reflective material and optically absorptive material is laterally displaced, causing a change in reflected light intensity.

  12. Reducing the impact of inhomogeneous broadening on quantum dot based electromagnetically induced transparency

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Mørk, Jesper

    2009-01-01

    Slow light based on electromagnetically induced transparency in an inhomogeneously broadened quantum dot medium is investigated theoretically. Three schemes, , V, and Λ, are compared and it is shown that the V-scheme gives a group velocity that is more than three orders of magnitude smaller...

  13. Electromagnetically induced transparency and absorption due to optical and ground-state coherences in 6Li

    International Nuclear Information System (INIS)

    Fuchs, J; Duffy, G J; Rowlands, W J; Lezama, A; Hannaford, P; Akulshin, A M

    2007-01-01

    We present an experimental study of sub-natural width resonances in fluorescence from a collimated beam of 6 Li atoms excited on the D 1 and D 2 lines by a bichromatic laser field. We show that in addition to ground-state Zeeman coherence, coherent population oscillations between ground and excited states contribute to the sub-natural resonances. High-contrast resonances of electromagnetically induced transparency and electromagnetically induced absorption due to both effects, i.e., ground-state Zeeman coherence and coherent population oscillations, are observed

  14. Optical spectroscopy study of transparent noncarious human dentin and dentin-enamel junction

    Science.gov (United States)

    Demos, Stavros G.; Balooch, Mehdi; Marshall, Grayson W.; Marshall, Sally J.; Gallagher, R. R.

    2000-03-01

    Improving our knowledge of the morphology, composition and properties of the dentin, enamel, and the dentin-enamel junction (DEJ) is vital for the development of improved restorative materials and clinical placement techniques. Most studies of dental tissues have used light microscopy for characterization. In our investigation, the spectroscopic properties of normal and non-carious transparent human root dentin, and the dentin-enamel junction were investigated using emission imaging microscopy, and micro-spectroscopy. Experimental results reveal new information on the structural and biochemical characteristics of these dental tissues.

  15. Optical Spectroscopy Study of Transparent Non-Carious Human Dentin and Dentin-Enamel Junction

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, G.W.; Marshall, S.J.; Gallagher, R.R.; Demos, S.

    1999-12-14

    Improving our knowledge of the morphology, composition and properties of the dentin, enamel, and the dentin-enamel junction (DEJ) is vital for the development of improved restorative materials and clinical placement techniques. Most studies of dental tissues have used light microscopy for characterization. In our investigation, the spectroscopic properties of normal and non-carious transparent human root dentin, and the dentin-enamel junction were investigated using emission imaging microscopy, and micro-spectroscopy. Experimental results reveal new information on the structural and biochemical characteristics of these dental tissues.

  16. Graphene based silicon–air grating structure to realize electromagnetically-induced-transparency and slow light effect

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Buzheng; Liu, Huaiqing [Key Lab of All Optical Network & Advanced Telecommunication Network of EMC, Beijing Jiaotong University, Beijing 100044 (China); Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044 (China); Ren, Guobin, E-mail: gbren@bjtu.edu.cn [Key Lab of All Optical Network & Advanced Telecommunication Network of EMC, Beijing Jiaotong University, Beijing 100044 (China); Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044 (China); Yang, Yuguang; Ye, Shen; Pei, Li; Jian, Shuisheng [Key Lab of All Optical Network & Advanced Telecommunication Network of EMC, Beijing Jiaotong University, Beijing 100044 (China); Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044 (China)

    2017-01-23

    Highlights: • The EIT and slow light effect are achieved by our novel graphene based structure. • Excellent tunability of wide wavelength range can be obtained only by a small change in Fermi energy level. • The group velocity of incident light is reduced to more than 1/600 of that in vacuum. • Position control is realized by designing a graded period grating. - Abstract: A broad band tunable graphene based silicon–air grating structure is proposed. Electromagnetically-induced-transparency (EIT) window can be successfully tuned by virtually setting the desired Fermi energy levels on graphene sheets. Carrier mobility plays an important role in modulating the resonant depth. Furthermore, by changing the grating periods, light can be trapped at corresponding resonant positions where slow down factor is relatively larger than in the previous works. This structure can be used as a highly tunable optoelectronic device such as optical filter, broad-band modulator, plasmonic switches and buffers.

  17. Optical intensities of Pr3+ ions in transparent oxyfluoride glass and glass-ceramic. Applications of the standard and modified Judd-Ofelt theories

    International Nuclear Information System (INIS)

    Genova, R.T.; Martin, I.R.; Rodriguez-Mendoza, U.R.; Lahoz, F.; Lozano-Gorrin, A.D.; Nunez, P.; Gonzalez-Platas, J.; Lavin, V.

    2004-01-01

    The optical characterisation of Pr 3+ ions in transparent SiO 2 -Al 2 O 3 -CdF 2 -PbF 2 -YF 3 based glass and glass-ceramic have been performed. From absorption and emission spectra the oscillator strengths of the 4f 2 -4f 2 electronic transitions have been obtained. The intensity parameters have been calculated using both the Judd-Ofelt theory and the modified theory developed by Kornienko, Kaminskii and Dunina. A comparison of the experimental oscillator strengths, the spontaneous emission probabilities and the lifetimes of the 3 P 0 level and those calculated using the above theoretical procedures has been performed for both samples. The root mean square deviation found using the standard Judd-Ofelt theory is larger than the value obtained with the modified treatment

  18. Diamond x-ray optics: Transparent, resilient, high-resolution, and wavefront preserving

    International Nuclear Information System (INIS)

    Shvyd’ko, Yuri; Blank, Vladimir; Terentyev, Sergey

    2017-01-01

    Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. Furthermore, they are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

  19. High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

    KAUST Repository

    Du, Qing Guo

    2016-02-24

    We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips. © 2016 Optical Society of America.

  20. Light storage in an optically thick atomic ensemble under conditions of electromagnetically induced transparency and four-wave mixing

    International Nuclear Information System (INIS)

    Phillips, Nathaniel B.; Novikova, Irina; Gorshkov, Alexey V.

    2011-01-01

    We study the modification of a traditional electromagnetically induced transparency (EIT) stored-light technique that includes both EIT and four-wave mixing (FWM) in an ensemble of hot Rb atoms. The standard treatment of light storage involves the coherent and reversible mapping of one photonic mode onto a collective spin coherence. It has been shown that unwanted, competing processes such as four-wave mixing are enhanced by EIT and can significantly modify the signal optical pulse propagation. We present theoretical and experimental evidence to indicate that, while a Stokes field is indeed detected upon retrieval of the signal field, any information originally encoded in a seeded Stokes field is not independently preserved during the storage process. We present a simple model that describes the propagation dynamics of the fields and the impact of FWM on the spin wave.

  1. Standard Test Method for Measuring Optical Angular Deviation of Transparent Parts Using the Double-Exposure Method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the measurement of the optical angular deviation of a light ray imposed by flat transparent parts such as a commercial or military aircraft windshield, canopy or cabin window. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 Exceptions—The values given in parentheses are for information only. Also, print size is provided in inch-pound measurements. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  2. Cu Microbelt Network Embedded in Colorless Polyimide Substrate: Flexible Heater Platform with High Optical Transparency and Superior Mechanical Stability.

    Science.gov (United States)

    Lee, Ji-Hyun; Youn, Doo-Young; Luo, Zhenhao; Moon, Ji Young; Choi, Seon-Jin; Kim, Chanhoon; Kim, Il-Doo

    2017-11-15

    Metal nanowires have been considered as essential components for flexible transparent conducting electrodes (TCEs) with high transparency and low sheet resistance. However, large surface roughness and high interwire junction resistance limit the practical use of metal wires as TCEs. Here, we report Cu microbelt network (Cu MBN) with coalescence junction and low surface roughness for next-generation flexible TCEs. In particular, the unique embedded structure of Cu MBN in colorless polyimide (cPI) film was achieved to reduce the surface roughness as well as enhance mechanical stability. The TCEs using junction-free Cu MBN embedded in cPI exhibited excellent mechanical stability up to 100 000 bending cycles, high transparency of 95.18%, and a low sheet resistance of 6.25 Ω sq -1 . Highly robust Cu MBN-embedded cPI-based TCE showed outstanding flexible heater performance, i.e., high saturation temperature (120 °C) at very low voltage (2.3 V), owing to the high thermal stability of cPI and excellent thermal conductivity of the Cu MBN.

  3. A Cost-Effective Transparency-Based Digital Imaging for Efficient and Accurate Wound Area Measurement

    Science.gov (United States)

    Li, Pei-Nan; Li, Hong; Wu, Mo-Li; Wang, Shou-Yu; Kong, Qing-You; Zhang, Zhen; Sun, Yuan; Liu, Jia; Lv, De-Cheng

    2012-01-01

    Wound measurement is an objective and direct way to trace the course of wound healing and to evaluate therapeutic efficacy. Nevertheless, the accuracy and efficiency of the current measurement methods need to be improved. Taking the advantages of reliability of transparency tracing and the accuracy of computer-aided digital imaging, a transparency-based digital imaging approach is established, by which data from 340 wound tracing were collected from 6 experimental groups (8 rats/group) at 8 experimental time points (Day 1, 3, 5, 7, 10, 12, 14 and 16) and orderly archived onto a transparency model sheet. This sheet was scanned and its image was saved in JPG form. Since a set of standard area units from 1 mm2 to 1 cm2 was integrated into the sheet, the tracing areas in JPG image were measured directly, using the “Magnetic lasso tool” in Adobe Photoshop program. The pixel values/PVs of individual outlined regions were obtained and recorded in an average speed of 27 second/region. All PV data were saved in an excel form and their corresponding areas were calculated simultaneously by the formula of Y (PV of the outlined region)/X (PV of standard area unit) × Z (area of standard unit). It took a researcher less than 3 hours to finish area calculation of 340 regions. In contrast, over 3 hours were expended by three skillful researchers to accomplish the above work with traditional transparency-based method. Moreover, unlike the results obtained traditionally, little variation was found among the data calculated by different persons and the standard area units in different sizes and shapes. Given its accurate, reproductive and efficient properties, this transparency-based digital imaging approach would be of significant values in basic wound healing research and clinical practice. PMID:22666449

  4. A cost-effective transparency-based digital imaging for efficient and accurate wound area measurement.

    Directory of Open Access Journals (Sweden)

    Pei-Nan Li

    Full Text Available Wound measurement is an objective and direct way to trace the course of wound healing and to evaluate therapeutic efficacy. Nevertheless, the accuracy and efficiency of the current measurement methods need to be improved. Taking the advantages of reliability of transparency tracing and the accuracy of computer-aided digital imaging, a transparency-based digital imaging approach is established, by which data from 340 wound tracing were collected from 6 experimental groups (8 rats/group at 8 experimental time points (Day 1, 3, 5, 7, 10, 12, 14 and 16 and orderly archived onto a transparency model sheet. This sheet was scanned and its image was saved in JPG form. Since a set of standard area units from 1 mm(2 to 1 cm(2 was integrated into the sheet, the tracing areas in JPG image were measured directly, using the "Magnetic lasso tool" in Adobe Photoshop program. The pixel values/PVs of individual outlined regions were obtained and recorded in an average speed of 27 second/region. All PV data were saved in an excel form and their corresponding areas were calculated simultaneously by the formula of Y (PV of the outlined region/X (PV of standard area unit × Z (area of standard unit. It took a researcher less than 3 hours to finish area calculation of 340 regions. In contrast, over 3 hours were expended by three skillful researchers to accomplish the above work with traditional transparency-based method. Moreover, unlike the results obtained traditionally, little variation was found among the data calculated by different persons and the standard area units in different sizes and shapes. Given its accurate, reproductive and efficient properties, this transparency-based digital imaging approach would be of significant values in basic wound healing research and clinical practice.

  5. A Web-based Tool for Transparent, Collaborative Urban Water System Planning for Monterrey, Mexico

    Science.gov (United States)

    Rheinheimer, D. E.; Medellin-Azuara, J.; Garza Díaz, L. E.; Ramírez, A. I.

    2017-12-01

    Recent rapid advances in web technologies and cloud computing show great promise for facilitating collaboration and transparency in water planning efforts. Water resources planning is increasingly in the context of a rapidly urbanizing world, particularly in developing countries. In such countries with democratic traditions, the degree of transparency and collaboration in water planning can mean the difference between success and failure of water planning efforts. This is exemplified in the city of Monterrey, Mexico, where an effort to build a new long-distance aqueduct to increase water supply to the city dramatically failed due to lack of transparency and top-down planning. To help address, we used a new, web-based water system modeling platform, called OpenAgua, to develop a prototype decision support system for water planning in Monterrey. OpenAgua is designed to promote transparency and collaboration, as well as provide strong, cloud-based, water system modeling capabilities. We developed and assessed five water management options intended to increase water supply yield and/or reliability, a dominant water management concern in Latin America generally: 1) a new long-distance source (the previously-rejected project), 2) a new nearby reservoir, 3) expansion/re-operation of an existing major canal, 4) desalination, and 5) industrial water reuse. Using the integrated modeling and analytic capabilities of OpenAgua, and some customization, we assessed the performance of these options for water supply yield and reliability to help identify the most promising ones. In presenting this assessment, we demonstrate the viability of using online, cloud-based modeling systems for improving transparency and collaboration in decision making, reducing the gap between citizens, policy makers and water managers, and future directions.

  6. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

  7. On event-based optical flow detection

    Directory of Open Access Journals (Sweden)

    Tobias eBrosch

    2015-04-01

    Full Text Available Event-based sensing, i.e. the asynchronous detection of luminance changes, promises low-energy, high dynamic range, and sparse sensing. This stands in contrast to whole image frame-wise acquisition by standard cameras. Here, we systematically investigate the implications of event-based sensing in the context of visual motion, or flow, estimation. Starting from a common theoretical foundation, we discuss different principal approaches for optical flow detection ranging from gradient-based methods over plane-fitting to filter based methods and identify strengths and weaknesses of each class. Gradient-based methods for local motion integration are shown to suffer from the sparse encoding in address-event representations (AER. Approaches exploiting the local plane like structure of the event cloud, on the other hand, are shown to be well suited. Within this class, filter based approaches are shown to define a proper detection scheme which can also deal with the problem of representing multiple motions at a single location (motion transparency. A novel biologically inspired efficient motion detector is proposed, analyzed and experimentally validated. Furthermore, a stage of surround normalization is incorporated. Together with the filtering this defines a canonical circuit for motion feature detection. The theoretical analysis shows that such an integrated circuit reduces motion ambiguity in addition to decorrelating the representation of motion related activations.

  8. Fabrication of semi-transparent super-hydrophobic surface based on silica hierarchical structures

    KAUST Repository

    Chen, Ping-Hei

    2011-01-01

    This study successfully develops a versatile method of producing superhydrophobic surfaces with micro/nano-silica hierarchical structures on glass surfaces. Optically transparent super hydrophobic silica thin films were prepared by spin-coating silica particles suspended in a precursor solution of silane, ethanol, and H2O with molar ratio of 1:4:4. The resulting super hydrophobic films were characterized by scanning electron microscopy (SEM), optical transmission, and contact angle measurements. The glass substrates in this study were modified with different particles: micro-silica particles, nano-silica particles, and hierarchical structures. This study includes SEM micrographs of the modified glass surfaces with hierarchical structures at different magnifications. © 2011 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

  9. Properties of TiO{sub 2}-based transparent conducting oxides

    Energy Technology Data Exchange (ETDEWEB)

    Hitosugi, Taro [Kanagawa Academy of Science and Technology (KAST), 213-0012 Kawasaki (Japan); Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 980-8577 Sendai (Japan); Yamada, Naoomi; Nakao, Shoichiro [Kanagawa Academy of Science and Technology (KAST), 213-0012 Kawasaki (Japan); Hirose, Yasushi; Hasegawa, Tetsuya [Kanagawa Academy of Science and Technology (KAST), 213-0012 Kawasaki (Japan); Department of Chemistry, University of Tokyo, 113-0033 Tokyo (Japan)

    2010-07-15

    The development and properties of titanium dioxide (TiO{sub 2})-based transparent conducting oxides (TCO), which exhibit properties comparable to those of In{sub 2-x}Sn{sub x}O{sub 3} (ITO), are reviewed in this article. An epitaxial thin film of anatase Ti{sub 0.94}Nb{sub 0.06}O{sub 2} exhibited a resistivity ({rho}) of 2.3 x 10{sup -4}{omega} cm and internal transmittance of {proportional_to}95% in the visible light region. Furthermore, we prepared polycrystalline films with {rho} of 6.4 x 10{sup -4}{omega} cm at room temperature on glass substrates by using sputtering. We focus on characteristics unique to TiO{sub 2}-based TCO, such as a high refractive index, high transmittance in infrared, and high stability in reducing atmospheres. Possible applications of TiO{sub 2}-based TCOs, as well as the mechanism of the transparent conducting properties found in this d-electron-based TCO, are discussed in this review. Photograph showing TiO{sub 2}-based TCO on a transparent plastic film. Note that the film appears greenish due to interference in the film originating from its high refractive index. This high refractive index is one of the unique characteristics of TiO{sub 2}-based TCO. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  10. The Shadow of Enlightenment Optical and Political Transparency in France 1789-1848

    CERN Document Server

    Levitt, Theresa

    2009-01-01

    This book is the first to place revolutionary advances in light and optics in the cultural context of France in the first half of the nineteenth century. The narrative follows the work and careers of France's two chief rivals on the subject of light: Arago and Biot. Their disagreement began on the subject of technical optics, but expanded to include politics, religion, agricultural policy, education, dinner companions, housing arrangements, photography, railroads, vital forces,astrology, the Egyptian calendar, and colonial slavery. At the heart of their disagreement was always a question of vi

  11. Optically transparent diamond-PDMS microfluidic system for electronic monitoring of cells

    Czech Academy of Sciences Publication Activity Database

    Babchenko, Oleg; Kromka, Alexander; Conde, J.P.; Chu, V.; Schmiedinger, T.; Rezek, Bohuslav

    2014-01-01

    Roč. 251, č. 12 (2014), s. 2593-2598 ISSN 0370-1972 R&D Projects: GA ČR GAP108/12/0996 Institutional support: RVO:68378271 Keywords : cells culturing * diamond sensor * electrical characterization * microfluidic system * optical monitoring * surface conductivity Subject RIV: BO - Biophysics Impact factor: 1.489, year: 2014

  12. Controlling the stability of nonlinear optical modes via electromagnetically induced transparency

    Science.gov (United States)

    Zhang, Kun; Liang, Yi-zeng; Lin, Ji; Li, Hui-jun

    2018-02-01

    We propose a scheme to generate and stabilize the high-dimensional spatial solitons via electromagnetically induced transparency (EIT). The system we consider is a resonant atomic ensemble having Λ configuration. We illustrate that under EIT conditions the equation satisfied by the probe field envelope is reduced to a saturable nonlinear Schrödinger equation with the trapping potential, provided by a far-detuned laser field and a random magnetic field. We present high-dimensional soliton solutions exhibiting many interesting characteristics, including diversity (i.e., many different types of soliton solutions can be found, including bright, ring multipole bright, ring multipole defect mode, multiring bright, multiring defect mode, and vortices solitons), the phase transition between bright soliton and higher-order defect modes (i.e., the phase transition can be realized by controlling the nonlinear coefficient or the intensity of the trapping potential), and stability (i.e., various solitons can be stabilized by the Gaussian potential provided by the far detuned laser field, or the random potential provided by the magnetic field). We also find that some solitons are the extension of the linear eigenmode, whereas others entirely derive from the role of nonlinearity. Compared with previous studies, we not only show the diverse soliton solutions in the same system but also find the boundary of the phase transition for the type of solitons. In addition, we present the possibility of using the random potential to stabilize various solitons and vortices.

  13. Optical Humidity Sensing Using Transparent Hybrid Film Composed of Cationic Magnesium Porphyrin and Clay Mineral.

    Science.gov (United States)

    Fujimura, Takuya; Shimada, Tetsuya; Sasai, Ryo; Takagi, Shinsuke

    2018-03-13

    A transparent hybrid film composed of cationic magnesium porphyrin and clay mineral was developed, and its chromic behavior depending on relative humidity (RH) was investigated. The hybrid film was obtained via intercalation of magnesium porphyrin into clay film; magnesium porphyrin was intercalated into the interlayer spaces of the clay mineral without aggregation. The absorption spectra of the hybrid film showed red shifts compared to the aqueous solution of magnesium porphyrin because of the π-conjugated system extension with coplanarization of the meso-substituted pyridinium group and porphyrin ring. The absorption maximum of the hybrid film was gradually shifted to a shorter wavelength, and the color of the hybrid film was changed with increasing RH. The X-ray diffraction measurement suggested that the basal space of clay was expanded with increasing RH, indicating that the interlayer space of clay was expanded by water adsorption, and the spectral shift was induced by the change in coplanarization degree between the porphyrin ring and meso-substituted pyridinium groups.

  14. ITO/Poly(Aniline/Sol-Gel Glass: An Optically Transparent, pH-Responsive Substrate for Supported Lipid Bilayers

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Obeidi

    2013-01-01

    Full Text Available Described here is fabrication of a pH-sensitive, optically transparent transducer composed of a planar indium-tin oxide (ITO electrode overcoated with a poly(aniline (PANI thin film and a porous sol-gel layer. Adsorption of the PANI film renders the ITO electrode sensitive to pH, whereas the sol-gel spin-coated layer makes the upper surface compatible with fusion of phospholipid vesicles to form a planar supported lipid bilayer (PSLB. The response to changes in the pH of the buffer contacting the sol-gel/PANI/ITO electrode is pseudo-Nernstian with a slope of 52 mV/pH over a pH range of 4–9. Vesicle fusion forms a laterally continuous PSLB on the upper sol-gel surface that is fluid with a lateral lipid diffusion coefficient of 2.2 μm2/s measured by fluorescence recovery after photobleaching. Due to its lateral continuity and lack of defects, the PSLB blocks the pH response of the underlying electrode to changes in the pH of the overlying buffer. This architecture is simpler to fabricate than previously reported ITO electrodes derivatized for PSLB formation and should be useful for optical monitoring of proton transport across supported membranes derivatized with ionophores and ion channels.

  15. Optical Control of Magnetic Feshbach Resonances by Closed-Channel Electromagnetically Induced Transparency

    Science.gov (United States)

    Jagannathan, A.; Arunkumar, N.; Joseph, J. A.; Thomas, J. E.

    2016-02-01

    We control magnetic Feshbach resonances in an optically trapped mixture of the two lowest hyperfine states of a 6Li Fermi gas, using two optical fields to create a dark state in the closed molecular channel. In the experiments, the narrow Feshbach resonance is tuned by up to 3 G. For the broad resonance, the spontaneous lifetime is increased to 0.4 s at the dark-state resonance, compared to 0.5 ms for single-field tuning. We present a new model of light-induced loss spectra, employing continuum-dressed basis states, which agrees in shape and magnitude with loss measurements for both broad and narrow resonances. Using this model, we predict the trade-off between tunability and loss for the broad resonance in 6Li, showing that our two-field method substantially reduces the two-body loss rate compared to single-field methods for the same tuning range.

  16. An Investigation on Properties of Transparent Concretes

    OpenAIRE

    TOPÇU, İlker Bekir; UYGUNOĞLU, Tayfun

    2016-01-01

    Transparentconcrete is a cement-based building material which has optical properties dueto the embedded light transmitting elements within the composite. In thisstudy, the design of transparent concrete, its mechanical properties, lighttransmission properties of optical fibers and the use of optic fibers werediscussed. The study was performed as a literature review, and it was focusedon the light absorption of translucent concrete, transmission, the mechanismand losses in the transmission. In...

  17. Fabrication and scintillation properties of highly transparent Pr:LuAG ceramics using Sc,La-based isovalent sintering aids

    Czech Academy of Sciences Publication Activity Database

    Shen, Y.; Feng, X.; Babin, Vladimir; Nikl, Martin; Vedda, A.; Moretti, F.; Dell'Orto, E.; Pan, Y.; Li, J.; Zeng, Y.

    2013-01-01

    Roč. 39, č. 5 (2013), s. 5985-5990 ISSN 0272-8842 R&D Projects: GA MŠk LH12185; GA AV ČR KAN300100802 Institutional support: RVO:68378271 Keywords : Pr:LuAG transparent ceramics * isovalent sintering aids * scintillation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.086, year: 2013

  18. an optical tweezer based study

    Indian Academy of Sciences (India)

    Shankar Ghosh

    2006-11-12

    Nov 12, 2006 ... Liquid-Solid interface. Liquid-liquid interface. Shankar Ghosh. Motion of a sphere in an .... Bare mass of a colloidal sphere ∼ 10^15Kg. Note : The effective mass scales with viscosity and not with the density. Shankar Ghosh. Motion of a sphere in an oscillatory boundary layer: an optical tweezer based study ...

  19. Highly conductive, transparent flexible films based on open rings of multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Ko, Wen-Yin; Su, Jun-Wei; Guo, Chian-Hua; Fu, Shu-Juan; Hsu, Chuen-Yuan; Lin, Kuan-Jiuh

    2011-01-01

    Open rings of multi-walled carbon nanotubes were stacked to form porous networks on a poly(ethylene terephthalate) substrate to form a flexible conducting film (MWCNT-PET) with good electrical conductivity and transparency by a combination of ultrasonic atomization and spin-coating technique. To enhance the electric flexibility, we spin-coated a cast film of poly(vinyl alcohol) onto the MWCNT-PET substrate, which then underwent a thermo-compression process. Field-emission scanning electron microscopy of the cross-sectional morphology illustrates that the film has a robust network with a thickness of ∼ 175 nm, and it remarkably exhibits a sheet resistance of approximately 370 Ω/sq with ∼ 77% transmittance at 550 nm even after 500 bending cycles. This electrical conductivity is much superior to that of other MWCNT-based transparent flexible films.

  20. Transparency in Transcribing: Making Visible Theoretical Bases Impacting Knowledge Construction from Open-Ended Interview Records

    Directory of Open Access Journals (Sweden)

    Audra Skukauskaite

    2012-01-01

    Full Text Available This article presents a reflexive analysis of two transcripts of an open-ended interview and argues for transparency in transcribing processes and outcomes. By analyzing ways in which a researcher's theories become consequential in producing and using transcripts of an open-ended interview, this paper makes visible the importance of examining and presenting theoretical bases of transcribing decisions. While scholars across disciplines have argued that transcribing is a theoretically laden process (GREEN, FRANQUIZ & DIXON, 1997; KVALE & BRINKMAN, 2009, few have engaged in reflexive analyses of the data history to demonstrate the consequences particular theoretical and methodological approaches pose in producing knowledge claims and inciting dialogues across traditions. The article demonstrates how theory-method-claim relationships in transcribing influence research transparency and warrantability. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1201146

  1. Acoustic imaging of vapor bubbles through optically non-transparent media

    International Nuclear Information System (INIS)

    Kolbe, W.F.; Turko, B.T.; Leskovar, B.

    1983-10-01

    A preliminary investigation of the feasibility of acoustic imaging of vapor bubbles through optically nontransparent media is described. Measurements are reported showing the echo signals produced by air filled glass spheres of various sizes positioned in an aqueous medium as well as signals produced by actual vapor bubbles within a water filled steel pipe. In addition, the influence of the metallic wall thickness and material on the amplitude of the echo signals is investigated. Finally several examples are given of the imaging of spherical bubbles within metallic pipes using a simulated array of acoustic transducers mounted circumferentially around the pipe. The measurement procedures and a description of the measuring system are also given

  2. Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystals

    DEFF Research Database (Denmark)

    Albert, Magnus; Dantan, Aurelien Romain; Drewsen, Michael

    2011-01-01

    The control of one light field by another, ultimately at the single photon level1, 2, 3, 4, 5, 6, 7, is a challenging task that has numerous interesting applications within nonlinear optics4, 5 and quantum information science6, 7, 8. This type of control can only be achieved through highly...... transmission to full absorption of a single photon probe field are achieved within unprecedentedly narrow EIT windows of a few tens of kilohertz. By applying a weak switching field, this allows us to demonstrate nearly perfect switching of the transmission of the probe field. The results represent important...

  3. A transparent flexible z-axis sensitive multi-touch panel based on colloidal ITO nanocrystals.

    Science.gov (United States)

    Sangeetha, N M; Gauvin, M; Decorde, N; Delpech, F; Fazzini, P F; Viallet, B; Viau, G; Grisolia, J; Ressier, L

    2015-08-07

    Bottom-up fabrication of a flexible multi-touch panel prototype based on transparent colloidal indium tin oxide (ITO) nanocrystal (NC) films is presented. A series of 7% Sn(4+) doped ITO NCs protected by oleate, octanoate and butanoate ligands are synthesized and characterized by a battery of techniques including, high resolution transmission electron microscopy, X-ray diffraction, (1)H, (13)C and (119)Sn nuclear magnetic resonance spectroscopy, and the related diffusion ordered spectroscopy. Electrical resistivities of transparent films of these NCs assembled on flexible polyethylene terephthalate substrates by convective self-assembly from their suspension in toluene decrease with the ligand length, from 220 × 10(3) for oleate ITO to 13 × 10(3)Ω cm for butanoate ITO NC films. A highly transparent, flexible touch panel based on a matrix of strain gauges derived from the least resistive film of 17 nm butanoate ITO NCs sensitively detects the lateral position (x, y) of the touch as well as its intensity over the z-axis. Being compatible with a stylus or bare/gloved finger, a larger version of this module may be readily implemented in upcoming flexible screens, enabling navigation capabilities over all three axes, a feature highly desired by the display industry.

  4. Transparent Low Electrostatic Charge Films Based on Carbon Nanotubes and Polypropylene. Homopolymer Cast Films

    Directory of Open Access Journals (Sweden)

    Zoe Vineth Quiñones-Jurado

    2018-01-01

    Full Text Available Use of multi-wall carbon nanotubes (MWCNTs in external layers (A-layers of ABA-trilayer polypropylene films was investigated, with the purpose of determining intrinsic and extrinsic factors that could lead to antistatic behavior of transparent films. The incorporation of 0.01, 0.1, and 1 wt % of MWCTNs in the A-layers was done by dilution through the masterbatch method. Masterbatches were fabricated using isotactic polypropylene (iPP with different melt flow indexes 2.5, 34, and 1200 g/10 min, and using different ultrasound assist methods. It was found that films containing MWCNTs show surface electrical resistivity of 1012 and 1016 Ω/sq, regardless of the iPP melt flow index (MFI and masterbatch fabrication method. However, electrostatic charge was found to depend upon the iPP MFI, the ultrasound assist method and MWCNT concentration. A percolation electron transport mechanism was determined most likely responsible for this behavior. Optical properties for films containing MWCNTs do not show significant differences compared to the reference film at MWCNT concentrations below 0.1 wt %. However, an enhancement in brightness was observed, and it was attributed to ordered iPP molecules wrapping the MWCNTs. Bright transparent films with low electrostatic charge were obtained even for MWCNTs concentrations as low as 0.01 wt %.

  5. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga; Simpson, John T.; Lupini, Andrew R.; Trejo, Rosa M.; Jellison, Gerald E.; Ivanov, Ilia N.; Pennycook, Stephen J.; Hillesheim, Daniel A.; Winter, Kyle O.; Christen, David K.; Hunter, Scott R.; Allen Haynes, J.

    2013-07-15

    Inspired by highly non-wetting natural biological surfaces (e.g., lotus leaves and water strider legs), artificial superhydrophobic surfaces that exhibit water droplet contact angles exceeding 150o have previously been constructed by utilizing various synthesis strategies.[ , , ] Such bio-inspired, water-repellent surfaces offer significant potential for numerous uses ranging from marine applications (e.g., anti-biofouling, anti-corrosion), anti-condensation (e.g., anti-icing, anti-fogging), membranes for selective separation (e.g., oil-water, gas-liquid), microfluidic systems, surfaces requiring reduced maintenance and cleaning, to applications involving glasses and optical materials.[ ] In addition to superhydrophobic attributes, for integration into device systems that have extended operational limits and overall improved performance, surfaces that also possess multifunctional characteristics are desired, where the functionality should match to the application-specific requirements.

  6. Optical Design of Porous ZnO/TiO2 Films for Highly Transparent Glasses with Broadband Ultraviolet Protection

    Directory of Open Access Journals (Sweden)

    Han Sung Song

    2017-01-01

    Full Text Available We present a design of a bilayer porous film structure on a glass substrate for the highly efficient ultraviolet (UV protection with high visible-light transparency. To effectively block UVB (280–315 nm and UVA (315–400 nm, titanium dioxide (TiO2 and zinc oxide (ZnO are used as absorbing layers having the appropriate coverages in different UV ranges with extinction coefficients, respectively. We show the process of refractive index (RI matching by controlling porosity (Pr. Effective RIs of porous media with TiO2 and ZnO were calculated based on volume averaging theory. Transmittances of the designed films with different effective RIs were calculated using rigorous coupled-wave analysis method. Using admittance loci method, the film thickness was optimized in center wavelengths from 450 to 550 nm. The results show that the optimal design provides high UV shielding performance at both UVA and UVB with high transparency in the visible range. We also analyze electrical field distributions in each layer and angle dependency with 3D HSV color map.

  7. Integrated-optics-based optical coherence tomography

    NARCIS (Netherlands)

    Nguyen, D.V.

    2013-01-01

    Optical coherence tomography (OCT) is a high resolution, imaging technique that has developed over the last 20 years from a complicated laboratory setup into a ready-to-use commercially available device. Instead of using electronic time gating as being used by ultrasound (US) imaging, in OCT, the

  8. Reduced graphene oxide filled poly(dimethyl siloxane) based transparent stretchable, and touch-responsive sensors

    International Nuclear Information System (INIS)

    Ponnamma, Deepalekshmi; Sadasivuni, Kishor Kumar; Cabibihan, John-John; Yoon, W. Jong; Kumar, Bijandra

    2016-01-01

    The ongoing revolution in touch panel technology and electronics demands the need for thin films, which are flexible, stretchable, conductive, and highly touch responsive. In this regard, conductive elastomer nanocomposites offer potential solutions for these stipulations; however, viability is limited to the poor dispersion of conductive nanomaterials such as graphene into the matrix. Here, we fabricated a reduced graphene oxide (rGO) and poly(dimethylsiloxane) (PDMS) elastomer based transparent and flexible conductive touch responsive film by dispersing rGO honeycombs uniformly into PDMS elastomer through an ionic liquid (IL) modification. Pursuing a simple, scalable, and safe method of solution casting, this provides a versatile and creative design of a transparent and stretchable rGO/IL-PDMS capacitive touch responsive, where rGO acts as a sensing element. This transparent film with ∼70% transmittance exhibits approximately a five times faster response in comparison to rGO/PDMS film, with negligible degradation over time. The performance of this touch screen film is expected to have applications in the emerging field of foldable electronics.

  9. Reduced graphene oxide filled poly(dimethyl siloxane) based transparent stretchable, and touch-responsive sensors

    Science.gov (United States)

    Ponnamma, Deepalekshmi; Sadasivuni, Kishor Kumar; Cabibihan, John-John; Yoon, W. Jong; Kumar, Bijandra

    2016-04-01

    The ongoing revolution in touch panel technology and electronics demands the need for thin films, which are flexible, stretchable, conductive, and highly touch responsive. In this regard, conductive elastomer nanocomposites offer potential solutions for these stipulations; however, viability is limited to the poor dispersion of conductive nanomaterials such as graphene into the matrix. Here, we fabricated a reduced graphene oxide (rGO) and poly(dimethylsiloxane) (PDMS) elastomer based transparent and flexible conductive touch responsive film by dispersing rGO honeycombs uniformly into PDMS elastomer through an ionic liquid (IL) modification. Pursuing a simple, scalable, and safe method of solution casting, this provides a versatile and creative design of a transparent and stretchable rGO/IL-PDMS capacitive touch responsive, where rGO acts as a sensing element. This transparent film with ˜70% transmittance exhibits approximately a five times faster response in comparison to rGO/PDMS film, with negligible degradation over time. The performance of this touch screen film is expected to have applications in the emerging field of foldable electronics.

  10. Reduced graphene oxide filled poly(dimethyl siloxane) based transparent stretchable, and touch-responsive sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ponnamma, Deepalekshmi [Center for Advanced Materials, Qatar University, P. O. Box 2713, Doha (Qatar); Sadasivuni, Kishor Kumar; Cabibihan, John-John [Mechanical and Industrial Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); Yoon, W. Jong [School of Science, Technology, Engineering, and Mathematics, University of Washington, Bothell, Washington 98011 (United States); Kumar, Bijandra, E-mail: bijandra.kumar@louisville.edu [Conn Center for Renewable Energy Research, University of Louisville, Louisville, Kentucky 40292 (United States); Research and Development Centre in Pharmaceutical Science and Applied Chemistry, Poona College of Pharmacy, Bharati Vidyapeeth Deemed University Erandawane, Pune 411038 (India)

    2016-04-25

    The ongoing revolution in touch panel technology and electronics demands the need for thin films, which are flexible, stretchable, conductive, and highly touch responsive. In this regard, conductive elastomer nanocomposites offer potential solutions for these stipulations; however, viability is limited to the poor dispersion of conductive nanomaterials such as graphene into the matrix. Here, we fabricated a reduced graphene oxide (rGO) and poly(dimethylsiloxane) (PDMS) elastomer based transparent and flexible conductive touch responsive film by dispersing rGO honeycombs uniformly into PDMS elastomer through an ionic liquid (IL) modification. Pursuing a simple, scalable, and safe method of solution casting, this provides a versatile and creative design of a transparent and stretchable rGO/IL-PDMS capacitive touch responsive, where rGO acts as a sensing element. This transparent film with ∼70% transmittance exhibits approximately a five times faster response in comparison to rGO/PDMS film, with negligible degradation over time. The performance of this touch screen film is expected to have applications in the emerging field of foldable electronics.

  11. Optical Enzyme Sensor for Urea Determination via Immobilized pH Indicator and Urease onto Transparent Membranes

    Directory of Open Access Journals (Sweden)

    Milka Krysteva

    2003-01-01

    Full Text Available Transparent triacetylcellulose membranes with immobilized pH indicator (neutral red as well as with simultaneously immobilized urease and neutral red were used as optical sensors for determination of urea concentrations in model solutions. Decomposition of urea with the enzyme urease is accompanied by evolution of ammonia. This leads to the changes of the neutral red absorption, which is proportional to the substrate (urea within certain concentration limits in model solution. As a result of the investigation, standard curves were plotted for determination of urea over the range of 1 to 500 mM using immobilized indicator and free urease. Simultaneous immobilization of indicator and urease permitted determination of urea in the interval 50 to 500 mM. The membrane used contained 0.169 U urease activity on an area of 1.7 cm2. The standard curves were plotted using the linear region of the kinetic curves for the corresponding substrate concentrations. A possible scheme of the interaction between the activated triacetylcellulose membrane and the indicator and enzyme is proposed. The membranes obtained are suitable for repeated ecological applications where urea is to be determined.

  12. Structural and Optical Investigations of Radiation Damage in Transparent PET Polymer Films

    Directory of Open Access Journals (Sweden)

    Shiv Govind Prasad

    2011-01-01

    Full Text Available Effects of gamma irradiation at different doses up to 135 kGy on polyethylene terephthalate (PET polymer films have been investigated by X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, and ultraviolet-visible (UV-VIS spectroscopy. From XRD analysis, it was found that even at a high dose of gamma irradiation of 135 kGy, crystallinity of the PET samples remain unchanged. However, the FTIR peak at 871 cm−1 (depicting C–H bending mode of out-of-plane vibration and another at 1303 cm−1 (representing C–H bending mode of in-plane vibration disappear for gamma-irradiated PET. In this study, it has also been found that γ-irradiation in air enhances the optical absorption in the wavelength region 320–370 nm. This has been attributed to free radicals being produced in the polymer by the γ-radiation. Further, the free radicals react with oxygen of air to form carbonyl group and hydroxyls. With increasing γ-dose, there is a red shift of the UV—near visible cutoff for PET. XRD and FTIR observations on γ-damage have been correlated.

  13. Preparation and Optical Properties of Infrared Transparent 3Y-TZP Ceramics

    Directory of Open Access Journals (Sweden)

    Chuanfeng Wang

    2017-04-01

    Full Text Available In the present study, a tough tetragonal zirconia polycrystalline (Y-TZP material was developed for use in high-speed infrared windows and domes. The influence of the preparation procedure and the microstructure on the material’s optical properties was evaluated by SEM and FT-IR spectroscopy. It was revealed that a high transmittance up to 77% in the three- to five-micrometer IR region could be obtained when the sample was pre-sintered at 1225 °C and subjected to hot isostatic pressing (HIP at 1275 °C for two hours. The infrared transmittance and emittance at elevated temperature were also examined. The in-line transmittance remained stable as the temperature increased to 427 °C, with degradation being observed only near the infrared cutoff edge. Additionally, the emittance property of 3Y-TZP ceramic at high temperature was found to be superior to those of sapphire and spinel. Overall, the results indicate that Y-TZP ceramic is a potential candidate for high-speed infrared windows and domes.

  14. A Novel Supercritical Fluid-Assisted Fabrication Technique for Producing Transparent Nanocomposites

    Science.gov (United States)

    2013-10-03

    methacrylate) (PMMA) and cellulose nanocrystals ( CNC ) nanocomposites 2. Transparent green polymer blends based on polylactic acid (PLA) and polypropylene...Fig-1: Schematic of SIFT Technology Fig-2: Optical Transparency of Neat PMMA and PMMA-1% CNC Nanocomposite Fig-3: Optical...Transparency at 400 and 700nm Wavelengths Fig-4: Tensile Moduli and Strain-at-break of PMMA and PMMA- CNC Nanocomposites ARO-STIR Program Final Progress

  15. On the Transparency of Client/Server-Based Haptic Interaction with Deformable Objects.

    Science.gov (United States)

    Schuwerk, Clemens; Xu, Xiao; Steinbach, Eckehard

    2017-01-01

    This paper studies the transparency of client/server-based haptic interaction with simulated deformable objects. In the considered remote interaction scenario, the server simulates the computationally expensive finite-element-based object deformation at a low temporal update rate and transmits the result to the clients. There, the received deformation data is applied to the polygon mesh, which is used to locally render force feedback with a penalty-based force rendering algorithm at the required high rate. Based on a one-dimensional deformable object example, we analyze the transparency of this multi-rate architecture for a two-user interaction. Communication delay leads to increased force magnitudes and an increased impedance displayed to the clients that actively interact with the object. We propose a method that adjusts the stiffness used in the local force rendering at the clients to compensate for this effect. The conducted objective and subjective evaluations show that the proposed method successfully compensates for the effect of communication delay in the tested delay range of up to 100 ms.

  16. A Compact Closed-Loop Optogenetics System Based on Artifact-Free Transparent Graphene Electrodes

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2018-03-01

    Full Text Available Electrophysiology is a decades-old technique widely used for monitoring activity of individual neurons and local field potentials. Optogenetics has revolutionized neuroscience studies by offering selective and fast control of targeted neurons and neuron populations. The combination of these two techniques is crucial for causal investigation of neural circuits and understanding their functional connectivity. However, electrical artifacts generated by light stimulation interfere with neural recordings and hinder the development of compact closed-loop systems for precise control of neural activity. Here, we demonstrate that transparent graphene micro-electrodes fabricated on a clear polyethylene terephthalate film eliminate the light-induced artifact problem and allow development of a compact battery-powered closed-loop optogenetics system. We extensively investigate light-induced artifacts for graphene electrodes in comparison to metal control electrodes. We then design optical stimulation module using micro-LED chips coupled to optical fibers to deliver light to intended depth for optogenetic stimulation. For artifact-free integration of graphene micro-electrode recordings with optogenetic stimulation, we design and develop a compact closed-loop system and validate it for different frequencies of interest for neural recordings. This compact closed-loop optogenetics system can be used for various applications involving optogenetic stimulation and electrophysiological recordings.

  17. Optical and fundamental band gaps disparity in transparent conducting oxides: new findings for the [Formula: see text] and [Formula: see text] systems.

    Science.gov (United States)

    Sabino, Fernando P; Nunes Oliveira, Luiz; Wei, Su-Huai; Da Silva, Juarez L F

    2017-03-01

    The optical band gap, extracted from absorption measurements, defines the figure of merit for transparent conducting oxides (TCOs). In many oxides, such as [Formula: see text] or [Formula: see text], inversion symmetry introduces a selection rule that blocks transitions from the valence-band maximum to the conduction-band minimum. This raises the absorption threshold and enlarges the optical gap relative to the fundamental band gap. Here, we present density-functional computations identifying two optical gaps, either of which can be detected, depending on the optical light intensity. Under strong illumination, weak transitions from [Formula: see text]-points near the valence-band maximum contribute significantly to the absorption spectrum and define an optical gap matching the fundamental gap. Low optical intensities by contrast give prominence to the large optical gap determined by the selection rule. While experimental conditions have favored observation of the former optical gap in [Formula: see text], in contrast, absorption measurements in [Formula: see text] have focused on the latter. Our findings explain the disparity between the optical and fundamental gaps in bixbyite [Formula: see text] and predict that, measured under low illumination, the optical gap for rutile [Formula: see text] will increase, from 3.60 eV to 4.34 eV.

  18. Magnetron sputtered Hf-B-Si-C-N films with controlled electrical conductivity and optical transparency, and with ultrahigh oxidation resistance

    Czech Academy of Sciences Publication Activity Database

    Šímová, V.; Vlček, J.; Zuzjaková, Š.; Houška, J.; Shen, Y.; Jiang, J. C.; Meletis, E. I.; Peřina, Vratislav

    2018-01-01

    Roč. 653, č. 5 (2018), s. 333-340 ISSN 0040-6090 R&D Projects: GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : Hf-B-Si-C-N films * pulsed reactive magnetron sputtering * electrical conductivitiy * optical transparency * high-temperature oxidation resistance Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.879, year: 2016

  19. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  20. High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

    Science.gov (United States)

    Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

    2018-02-01

    In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10-5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V-1 s-1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

  1. Highly Conductive, Transparent Flexible Films Based on Metal Nanoparticle-Carbon Nanotube Composites

    Directory of Open Access Journals (Sweden)

    Wen-Yin Ko

    2013-01-01

    Full Text Available Metallic nanoparticles decorated on MWCNTs based transparent conducting thin films (TCFs show a cheap and efficient option for the applications in touch screens and the replacement of the ITO film because of their interesting properties of electrical conductivity, mechanical property, chemical inertness, and other unique properties, which may not be accessible by their individual components. However, a great challenge that always remains is to develop effective ways to prepare junctions between metallic nanoparticles and MWCNTs for the improvement of high-energy barriers, high contact resistances, and weak interactions which could lead to the formation of poor conducting pathways and result in the CNT-based devices with low mechanical flexibility. Herein, we not only discuss recent progress in the preparation of MNP-CNT flexible TCFs but also describe our research studies in the relevant areas. Our result demonstrated that the MNP-CNT flexible TCFs we prepared could achieve a highly electrical conductivity with the sheet resistance of ~100 ohm/sq with ~80% transmittance at 550 nm even after being bent 500 times. This electrical conductivity is much superior to the performances of other MWCNT-based transparent flexible films, making it favorable for next-generation flexible touch screens and optoelectronic devices.

  2. Rabi oscillations and self-induced transparency in InAs/InP quantum dot semiconductor optical amplifier operating at room temperature.

    Science.gov (United States)

    Karni, Ouri; Capua, Amir; Eisenstein, Gadi; Sichkovskyi, Vitalii; Ivanov, Vitalii; Reithmaier, Johann Peter

    2013-11-04

    We report direct observations of Rabi oscillations and self-induced transparency in a quantum dot optical amplifier operating at room temperature. The experiments make use of pulses whose durations are shorter than the coherence time which are characterized using Cross-Frequency-Resolved Optical Gating. A numerical model which solves the Maxwell and Schrödinger equations and accounts for the inhomogeneously broadened nature of the quantum dot gain medium confirms the experimental results. The model is also used to explain the relationship between the observability of Rabi oscillations, the pulse duration and the homogeneous and inhomogeneous spectral widths of the semiconductor.

  3. Implementation of transparency and accountability under risk-based audit of electronic procurement system

    Directory of Open Access Journals (Sweden)

    M.S. Pysmenna

    2017-08-01

    Full Text Available The research analyzes the international norms and practice of realization of the purpose of state audit authorities. It is established that the activities of the state audit are aimed at improving the lives of citizens, and for this purpose the control authority, through the implementation of the principles, should achieve the goals of strengthening the principles of accountability, transparency and integrity in government and public institutions, demonstrating constant importance for citizens, parliament and other stakeholders, maintaining integrity. The study of domestic legislation on state audit in relation to compliance with international norms is conducted; the gaps and inconsistencies regarding compliance with the basic principles of transparency and accountability that ensure the purpose of the control authority activities are identified. It is determined that in order to formulate reports on the results of public procurement audits for informing the public, it is necessary to improve and apply a broader methodology of risk-based audit. The article investigates the preconditions and identifies the risks of the electronic procurement system, provides their characteristics and identifies the areas, which are negatively affected by the risks. The author identifies the information components and management functions that cannot be performed qualitatively because of the existence of risks and threats; the author also specifies the procedures for internal control over the process of administration of public procurement, and if the procedures are faced with failure, it increases the identified risks. It is proved that the proposed method of identification and evaluation of the risks of the electronic public procurement system can be used not only as a verification tool but also as the basis for compilation of reports due to the grouping of violations of the negative consequences of risks for the functioning of the system. This will ensure the

  4. Single-walled carbon nanotube based transparent immunosensor for detection of a prostate cancer biomarker osteopontin

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Abhinav; Hong, Seongkyeol; Singh, Renu [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); Jang, Jaesung, E-mail: jjang@unist.ac.kr [School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of)

    2015-04-15

    Highlights: • A transparent CNT immunosensor is presented for detection of a prostate cancer biomarker osteopontin. • This immunosensor showed a highly linear and reproducible behavior from 1 pg mL{sup −1} to 1 μg mL{sup −1}. • The limit of detection of the immunosensor was 0.3 pg mL{sup −1}. • This immunosensor demonstrated high selectivity against bovine serum albumin and human serum. - Abstract: Osteopontin (OPN) is involved in almost all steps of cancer development, and it is being investigated as a potential biomarker for a diagnosis and prognosis of prostate cancer. Here, we report a label-free, highly sensitive and transparent immunosensor based on single-walled carbon nanotubes (SWCNTs) for detection of OPN. A high density of −COOH functionalized SWCNTs was deposited between two gold/indium tin oxide electrodes on a glass substrate by dielectrophoresis. Monoclonal antibodies specific to OPN were covalently immobilized on the SWCNTs. Relative resistance change of the immunosensors was measured as the concentration of OPN in phosphate buffer saline (PBS) and human serum was varied from 1 pg mL{sup −1} to 1 μg mL{sup −1} for different channel lengths of 2, 5, and 10 μm, showing a highly linear and reproducible behavior (R{sup 2} > 97%). These immunosensors were also specific to OPN against another test protein, bovine serum albumin, PBS and human serum, showing that a limit of detection for OPN was 0.3 pg mL{sup −1}. This highly sensitive and transparent immunosensor has a great potential as a simple point-of-care test kit for various protein biomarkers.

  5. Observation of convection phenomenon by high-performance transparent heater based on Pt-decorated Ni micromesh

    Directory of Open Access Journals (Sweden)

    Han-Jung Kim

    2017-02-01

    Full Text Available In this study, we report for the first time on the convection phenomenon for the consistent and sensitive detection of target materials (particulate matter (PM or gases with a high-performance transparent heater. The high-performance transparent heater, based on Pt-decorated Ni micromesh, was fabricated by a combination of transfer printing process and Pt sputtering. The resulting transparent heater exhibited excellent mechanical durability, adhesion with substrates, flexibility, and heat-generating performance. We monitored the changes in the PM concentration and temperature in an airtight chamber while operating the heater. The temperature in the chamber was increased slightly, and the PM2.5 concentration was increased by approximately 50 times relative to the initial state which PM is deposed in the chamber. We anticipate that our experimental findings will aid in the development and application of heaters for sensors and actuators as well as transparent electrodes and heating devices.

  6. Influence of ionizing radiation on optical hardness of transparent dielectrics to action of huge intensity laser light

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Khalilov, R.A.

    2006-01-01

    Full text: This paper presents results of researches of optical hardness of γ -irradiated with doze 10 4 - 10 9 rad alkali-silicate (K, GLS, LGS) and quartz (KU, KV, KSG) glasses against influence of radiation neodymium laser with intensity q = 0,1-1000 GWt/cm 2 . It is observed, that the laser produces damage of surface and volume of investigated glasses before and after γ-irradiation. This damage has threshold character and is always accompanied by a bright luminescence of plasma. Definition of threshold values of intensity superficial q s and volumetric q d laser produced damage was made by the complex method - fixing the moment of damage of transparent dielectric by simultaneous registration of the laser impulse which has passed through plasma of breakdown, mass-charge spectrum of ions of plasma and measuring the energy falling on the glass, and of penetrated and mirror-image radiations; and by optical microscopy. This method of research of influence γ-induced in transparent dielectric radiating defects on its optical stability against influence of laser radiation allows not only to define values q s and q d in the investigated interval of dozes, but also to investigate in details physical phenomena taking place in this process of interaction. On the basis of the received data quantitative characteristics of optical durability of the investigated glasses on wave length of λ1,06 microns depending on dozes of γ-irradiation and intensity of laser radiation are made. Doze dependences of charge and power spectra and quantitative characteristics of ions of plasma of breakdown were investigated at q≥ q s . In the investigated interval of dozes of γ- irradiation and intensity of laser radiation by a method of optical microscopy the morphology of occurring laser damage as surfaces, and volume of glass is also studied. It is found, that γ -induced defects in investigated glasses strongly effect on thresholds of damage q s and q d and on characteristics of ions

  7. Optical, morphological properties and surface energy of the transparent Li4Ti5O12 (LTO) thin film as anode material for secondary type batteries

    Science.gov (United States)

    Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan

    2016-03-01

    LTO thin film was deposited for the first time on a glass microscope slide (MS) by RF magnetron sputtering technology. This method has been suitable for preparation of high-quality thin films. The surface properties of the produced film were determined by atomic force microscope (AFM). The surface of the produced film appeared smooth and homogeneous. LTO coated on MS had compact structure and low roughness. A UV-vis spectrophotometer was used to determine intensity of light passing through the samples. Thus, according to the results obtained the produced film was highly transparent. The refractive index of the LTO thin film was presented in a low MSE value by spectroscopic ellipsometry (SE) and it was about 1.5. The optical band gap (E g) was determined by the Tauc method. The produced LTO thin film exhibited a wide band gap semiconductor property with a band gap energy of about 2.95 eV. Finally, the surface free energy of the LTO thin film was calculated from the contact angle measurements using the Lewis acid-base, OWRK/Fowkes, Wu and Zisman methods.

  8. Knowledge-based optical system design

    Science.gov (United States)

    Nouri, Taoufik

    1992-03-01

    This work is a new approach for the design of start optical systems and represents a new contribution of artificial intelligence techniques in the optical design field. A knowledge-based optical-systems design (KBOSD), based on artificial intelligence algorithms, first order logic, knowledge representation, rules, and heuristics on lens design, is realized. This KBOSD is equipped with optical knowledge in the domain of centered dioptrical optical systems used at low aperture and small field angles. It generates centered dioptrical, on-axis and low-aperture optical systems, which are used as start systems for the subsequent optimization by existing lens design programs. This KBOSD produces monochromatic or polychromatic optical systems, such as singlet lens, doublet lens, triplet lens, reversed singlet lens, reversed doublet lens, reversed triplet lens, and telescopes. In the design of optical systems, the KBOSD takes into account many user constraints such as cost, resistance of the optical material (glass) to chemical, thermal, and mechanical effects, as well as the optical quality such as minimal aberrations and chromatic aberrations corrections. This KBOSD is developed in the programming language Prolog and has knowledge on optical design principles and optical properties. It is composed of more than 3000 clauses. Inference engine and interconnections in the cognitive world of optical systems are described. The system uses neither a lens library nor a lens data base; it is completely based on optical design knowledge.

  9. Optical computation based on nonlinear total reflectional optical ...

    Indian Academy of Sciences (India)

    ∗ ... kind of all-optical computation which is based on the polarization coding technique and the nonlinear total reflectional ..... [8] G P Agrawal, Nonlinear fiber optics, 3rd edn (Academic Press, Boston, 2005). S X Qian and R Y Zhu, Nonlinear ...

  10. Optical computation based on nonlinear total reflectional optical ...

    Indian Academy of Sciences (India)

    A new scheme of binary half adder and full adder is proposed. It realizes a kind of all-optical computation which is based on the polarization coding technique and the nonlinear total reflectional optical switches. Author Affiliations. Jianqi Zhang1 Huan Xu2. Laboratory of Photonic Information Technology, School of ...

  11. Inkjet printing of metal-oxide-based transparent thin-film capacitors

    Science.gov (United States)

    Matavž, A.; Malič, B.; Bobnar, V.

    2017-12-01

    We report on the inkjet printing of transparent, thin-film capacitors (TTFCs) composed of indium-zinc-oxide electrodes and a tantalum-oxide-based dielectric on glass substrates. The printing parameters were adapted for the sequential deposition of functional layers, resulting in approximately 100-nm-thick transparent capacitors with a uniform thickness. The relatively high electrical resistivity of the electrodes is reflected in the frequency dispersive dielectric behaviour, which is explained in terms of an equivalent circuit. The resistivity of the electrode strongly decreases with the number of printing passes; consequently, any misalignment of the printed layers is detected in the measured response. At low frequency, the TTFCs show a stable intrinsic dielectric response and a high capacitance density of ˜280 nF/cm2. The good dielectric performance as well as the low leakage-current density (8 × 10-7 A/cm2 at 1 MV cm-1) of our capacitors indicates that inkjet printing can be used to produce all-printed, high-quality electrical devices.

  12. A Fully Transparent Flexible Sensor for Cryogenic Temperatures Based on High Strength Metallurgical Graphene

    Directory of Open Access Journals (Sweden)

    Ryszard Pawlak

    2016-12-01

    Full Text Available Low-temperature electronics operating in below zero temperatures or even below the lower limit of the common −65 to 125 °C temperature range are essential in medical diagnostics, in space exploration and aviation, in processing and storage of food and mainly in scientific research, like superconducting materials engineering and their applications—superconducting magnets, superconducting energy storage, and magnetic levitation systems. Such electronic devices demand special approach to the materials used in passive elements and sensors. The main goal of this work was the implementation of a fully transparent, flexible cryogenic temperature sensor with graphene structures as sensing element. Electrodes were made of transparent ITO (Indium Tin Oxide or ITO/Ag/ITO conductive layers by laser ablation and finally encapsulated in a polymer coating. A helium closed-cycle cryostat has been used in measurements of the electrical properties of these graphene-based temperature sensors under cryogenic conditions. The sensors were repeatedly cooled from room temperature to cryogenic temperature. Graphene structures were characterized using Raman spectroscopy. The observation of the resistance changes as a function of temperature indicates the potential use of graphene layers in the construction of temperature sensors. The temperature characteristics of the analyzed graphene sensors exhibit no clear anomalies or strong non-linearity in the entire studied temperature range (as compared to the typical carbon sensor.

  13. A tunable fiber-optic LED illumination system for non-invasive measurements of the characteristics of a transparent fiber

    Science.gov (United States)

    Świrniak, Grzegorz; Głomb, Grzegorz

    2017-06-01

    This study reports an application of a fiber-optic LED-based illumination system to solve an inverse problem in optical measurements of characteristics of a single-mode fiber. The illumination system has the advantages of low temporal coherence, high intensity, collimation, and thermal stability of the emission spectrum. The inverse analysis is investigated to predict the values of the diameter and refractive index of a single-mode fiber and applies to the far field scattering pattern in the vicinity of a polychromatic rainbow. As the inversion possibility depends considerably on the properties of the incident radiation, a detailed discussion is provided on both the specification of the illumination system as well as preliminary characteristics of the produced radiation. The illumination system uses a direct coupling between a thermally-stabilized LED junction and a plastic optical fiber, which transmits light to an optical collimator. A numerical study of fiber-to-LED coupling efficiency helps to understand the influence of lateral and longitudinal misalignments on the output power.

  14. Design and realization of transparent solar modules based on luminescent solar concentrators integrating nanostructured photonic crystals

    Science.gov (United States)

    Jiménez‐Solano, Alberto; Delgado‐Sánchez, José‐Maria; Calvo, Mauricio E.; Miranda‐Muñoz, José M.; Lozano, Gabriel; Sancho, Diego; Sánchez‐Cortezón, Emilio

    2015-01-01

    Abstract Herein, we present a prototype of a photovoltaic module that combines a luminescent solar concentrator integrating one‐dimensional photonic crystals and in‐plane CuInGaSe2 (CIGS) solar cells. Highly uniform and wide‐area nanostructured multilayers with photonic crystal properties were deposited by a cost‐efficient and scalable liquid processing amenable to large‐scale fabrication. Their role is to both maximize light absorption in the targeted spectral range, determined by the fluorophore employed, and minimize losses caused by emission at angles within the escape cone of the planar concentrator. From a structural perspective, the porous nature of the layers facilitates the integration with the thermoplastic polymers typically used to encapsulate and seal these modules. Judicious design of the module geometry, as well as of the optical properties of the dielectric mirrors employed, allows optimizing light guiding and hence photovoltaic performance while preserving a great deal of transparency. Optimized in‐plane designs like the one herein proposed are of relevance for building integrated photovoltaics, as ease of fabrication, long‐term stability and improved performance are simultaneously achieved. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. PMID:27656090

  15. Design and realization of transparent solar modules based on luminescent solar concentrators integrating nanostructured photonic crystals.

    Science.gov (United States)

    Jiménez-Solano, Alberto; Delgado-Sánchez, José-Maria; Calvo, Mauricio E; Miranda-Muñoz, José M; Lozano, Gabriel; Sancho, Diego; Sánchez-Cortezón, Emilio; Míguez, Hernán

    2015-12-01

    Herein, we present a prototype of a photovoltaic module that combines a luminescent solar concentrator integrating one-dimensional photonic crystals and in-plane CuInGaSe 2 (CIGS) solar cells. Highly uniform and wide-area nanostructured multilayers with photonic crystal properties were deposited by a cost-efficient and scalable liquid processing amenable to large-scale fabrication. Their role is to both maximize light absorption in the targeted spectral range, determined by the fluorophore employed, and minimize losses caused by emission at angles within the escape cone of the planar concentrator. From a structural perspective, the porous nature of the layers facilitates the integration with the thermoplastic polymers typically used to encapsulate and seal these modules. Judicious design of the module geometry, as well as of the optical properties of the dielectric mirrors employed, allows optimizing light guiding and hence photovoltaic performance while preserving a great deal of transparency. Optimized in-plane designs like the one herein proposed are of relevance for building integrated photovoltaics, as ease of fabrication, long-term stability and improved performance are simultaneously achieved. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd.

  16. Indium oxide-based transparent conductive films deposited by reactive sputtering using alloy targets

    Science.gov (United States)

    Miyazaki, Yusuke; Maruyama, Eri; Jia, Junjun; Machinaga, Hironobu; Shigesato, Yuzo

    2017-04-01

    High-quality transparent conductive oxide (TCO) films, Sn-doped In2O3 (ITO) and In2O3-ZnO (IZO), were successfully deposited on either synthetic silica or polyethylene terephthalate (PET) substrates in the “transition region” by reactive dc magnetron sputtering using In-Zn and In-Sn alloy targets, respectively, with a specially designed plasma emission feedback system. The composition, crystallinity, surface morphology, and electrical and optical properties of the films were analyzed. All of the IZO films were amorphous, whereas the ITO films were polycrystalline over a wide range of deposition conditions. The minimum resistivities of the IZO and ITO films deposited on the heated PET substrates at 150 °C were 3.3 × 10-4 and 5.4 × 10-4 Ω·cm, respectively. By applying rf bias to unheated PET substrates, ITO films with a resistivity of 4.4 × 10-4 Ω·cm were deposited at a dc self-bias voltage of -60 V.

  17. Fabrication of transparent superhydrophobic silica-based film on a glass substrate

    Science.gov (United States)

    Wang, Shing-Dar; Luo, Shih-Shiang

    2012-05-01

    Tetraethoxysilane (TEOS) was hydrolyzed in an acidic environment and then reacted with hexamethyldisilazane (HMDS) to obtain a superhydrophobic transparent film on a glass substrate. The molar ratios of water and ethanol to TEOS, the pH value of the acidic (or basic) water that is used to hydrolyze TEOS, the heat treatment conditions and other factors were investigated systematically to optimize the transmission through, and the contact angle of water on the film. HMDS (total amount of HMDS/TEOS = 2) was divided into 20 parts, which were added into the sol successively to prevent the sudden production of a large quantity of NH3 in a small area of the sol. The optical and hydrophobic properties of the sol gel continued to change after it had been prepared. The conditions that TEOS was hydrolyzed with acidic water at pH 1.2 at 70 °C and the sol gel was aged at 20 °C for 48 h realized transmission of 90.9% and a water contact angle of 154.3°. No additional surface chemistry modification was needed.

  18. Transparency in Organizing

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa

    to being a solution for efficiency and democratic organizing, is a communicatively contested process which may lead to unintended consequences. The dissertation shows that transparency is performative: it can impact authority by de/legitimating action, shape the processes of organizational identity co......This dissertation provides a critical analysis of transparency in the context of organizing. The empirical material is based on qualitative studies of international cooperative organizations. The dissertation seeks to contribute to transparency and organizing scholarship by adopting a communication...

  19. Spectral and optical performance of electrochromic poly(3,4-ethylenedioxythiophene) (PEDOT) deposited on transparent conducting oxide coated glass and polymer substrates

    International Nuclear Information System (INIS)

    Sindhu, S.; Narasimha Rao, K.; Ahuja, Sharath; Kumar, Anil; Gopal, E.S.R.

    2006-01-01

    Electrochromic devices utilizing conjugated polymers as electrochromic layers have gained increasing attention owing to their optical properties, fast switching times and contrast ratios. Polyethylenedioxythiophene (PEDOT) is an excellent material from its electrochromic properties, high conductivity and high stability in the doped form. Aqueous dispersions of PEDOT were either spin coated or electro-polymerized on transparent conducting oxide coated glass and polyethylene tetraphthalate (PET) film substrates. The spectro- and opto-electrochemical studies of the films on transparent conducting oxide coated glass/PET substrates were performed. These films have application in the fabrication of electrochromic windows (smart windows). Smart window devices having excellent switching characteristics over wide range of temperature are used for glazing applications. The aerospace industry is interested in the development of visors and windows that can control glare for pilots and passengers, especially if the coatings can be made on curved surfaces and electrically conducting

  20. Analysis of a time-lens based optical frame synchronizer and retimer for 10G Ethernet aiming at a Tb/s optical router/switch design

    DEFF Research Database (Denmark)

    Laguardia Areal, Janaina; Hu, Hao; Peucheret, Christophe

    2010-01-01

    This paper analyzes experimentally and by numerical simulations an optical frame retimer and synchronizer unit for 10 Gbit/s Ethernet input frames. The unit is envisaged to be applied in the design of an optically transparent router for Optical Time Division Multiplexed (OTDM) links, aggregating...... traffic from several 10 Gbit/s Ethernet (10 GE) links. The scheme is based on time-lenses implemented through a combination of a sinusoidally driven optical phase modulation and linear dispersion. Our analysis extracts the operation range of the scheme used for synchronization and retiming in the context...

  1. Transparency in Organizing

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa

    This dissertation provides a critical analysis of transparency in the context of organizing. The empirical material is based on qualitative studies of international cooperative organizations. The dissertation seeks to contribute to transparency and organizing scholarship by adopting a communication...... centred approach to explore the implications of pursuing ideals of transparency in organizational relationships. The dissertation is comprised of four papers each contributing to extant debates in organizational studies and transparency literature. The findings indicate that transparency, in contrast...... to being a solution for efficiency and democratic organizing, is a communicatively contested process which may lead to unintended consequences. The dissertation shows that transparency is performative: it can impact authority by de/legitimating action, shape the processes of organizational identity co...

  2. Passive polarization agile antenna based on the electromagnetically induced transparency-like effect

    International Nuclear Information System (INIS)

    Zhu, Lei; Meng, Fan-Yi; Wu, Qun; Chen, Wan; Fu, Jia-Hui; Dong, Liang

    2014-01-01

    We propose a design method for a passive polarization agile antenna based on the electromagnetically induced transparency-like (EIT-like) effect. Benefiting from strong dispersion properties governed by EIT-like effects, the proposed structure can endow electromagnetic waves transmitted through it with quite different polarization states at very close frequencies. The experimental measurement was conducted to demonstrate agile polarization controls by placing a designed EIT-like waveplate in front of a standard microwave horn antenna. Results show that the polarization state of radiated waves by the horn antenna with a waveplate can be easily transformed among linear, circular and elliptical polarizations through fine-tuning the operating frequency, which is extremely important for certain special applications, e.g. electronic countermeasures. Our scheme could also be utilized at higher operating frequencies by the simply scaling principle. (paper)

  3. Passive polarization agile antenna based on the electromagnetically induced transparency-like effect

    Science.gov (United States)

    Zhu, Lei; Meng, Fan-Yi; Wu, Qun; Dong, Liang; Chen, Wan; Fu, Jia-Hui

    2014-10-01

    We propose a design method for a passive polarization agile antenna based on the electromagnetically induced transparency-like (EIT-like) effect. Benefiting from strong dispersion properties governed by EIT-like effects, the proposed structure can endow electromagnetic waves transmitted through it with quite different polarization states at very close frequencies. The experimental measurement was conducted to demonstrate agile polarization controls by placing a designed EIT-like waveplate in front of a standard microwave horn antenna. Results show that the polarization state of radiated waves by the horn antenna with a waveplate can be easily transformed among linear, circular and elliptical polarizations through fine-tuning the operating frequency, which is extremely important for certain special applications, e.g. electronic countermeasures. Our scheme could also be utilized at higher operating frequencies by the simply scaling principle.

  4. Vector magnetometry based on electromagnetically induced transparency in linearly polarized light

    International Nuclear Information System (INIS)

    Yudin, V. I.; Taichenachev, A. V.; Dudin, Y. O.; Velichansky, V. L.; Zibrov, A. S.; Zibrov, S. A.

    2010-01-01

    We develop a generalized principle of electromagnetically induced transparency (EIT) vector magnetometry based on high-contrast EIT resonances and the symmetry of atom-light interaction in the linearly polarized bichromatic fields. Operation of such vector magnetometer on the D 1 line of 87 Rb has been demonstrated. The proposed compass-magnetometer has an increased immunity to shifts produced by quadratic Zeeman and ac-Stark effects, as well as by atom-buffer gas and atom-atom collisions. In our proof-of-principle experiment the detected angular sensitivity to magnetic field orientation is 10 -3 deg/Hz 1/2 , which is limited by laser intensity fluctuations, light polarization quality, and magnitude of the magnetic field.

  5. Transparent and flexible write-once-read-many (WORM) memory device based on egg albumen

    Science.gov (United States)

    Qu, Bo; Lin, Qianru; Wan, Tao; Du, Haiwei; Chen, Nan; Lin, Xi; Chu, Dewei

    2017-08-01

    Egg albumen, as an important protein resource in nature, is an interesting dielectric material exhibiting many fascinating properties for the development of environmentally friendly electronic devices. Taking advantage of their extraordinary transparency and flexibility, this paper presents an innovative preparation approach for albumen thin film based write-once-read-many-times (WORM) memory devices in a simple, cost-effective manner. The fabricated device shows superior data retention properties including non-volatile character (over 105 s) and promising great read durability (106 times). Furthermore, our results suggested that the electric-field-induced trap-controlled space charge limited current (SCLC) conduction is responsible for the observed resistance switching effect. The present study may likely reveal another pathway towards complete see-through electrical devices.

  6. Transparent and flexible write-once-read-many (WORM) memory device based on egg albumen

    International Nuclear Information System (INIS)

    Qu, Bo; Lin, Qianru; Wan, Tao; Du, Haiwei; Chen, Nan; Lin, Xi; Chu, Dewei

    2017-01-01

    Egg albumen, as an important protein resource in nature, is an interesting dielectric material exhibiting many fascinating properties for the development of environmentally friendly electronic devices. Taking advantage of their extraordinary transparency and flexibility, this paper presents an innovative preparation approach for albumen thin film based write-once-read-many-times (WORM) memory devices in a simple, cost-effective manner. The fabricated device shows superior data retention properties including non-volatile character (over 10 5 s) and promising great read durability (10 6 times). Furthermore, our results suggested that the electric-field-induced trap-controlled space charge limited current (SCLC) conduction is responsible for the observed resistance switching effect. The present study may likely reveal another pathway towards complete see-through electrical devices. (paper)

  7. Tailoring polarization of electromagnetically induced transparency based on non-centrosymmetric metasurfaces

    Science.gov (United States)

    Li, Hai-ming; Xue, Feng

    2017-09-01

    In this manuscript, tailoring polarization of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the bright mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a polarization insensitive EIT-like transmission window can be observed at specific polarization angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring polarization of EIT-like metamaterial with large group index at specific polarization angles may have potential application in slow light devices.

  8. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...... wavelength. It is shown that it is possible to tune and modulate a DFB fiber laser with both strain from a piezoelectric transducer and by temperature through resistive heating of a methal film. Both a chemical deposited silver layer and an electron-beam evaporation technique has been investigated, to find...

  9. Organizational Transparency

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa; Flyverbom, Mikkel

    2018-01-01

    Transparency is an increasingly prominent area of research that offers valuable insights for organizational studies. However, conceptualizations of transparency are rarely subject to critical scrutiny and thus their relevance remains unclear. In most accounts, transparency is associated...... that shape the extant literature, with a focus on three dimensions: conceptualizations, conditions, and consequences. The contribution of the study is twofold: (a) On a conceptual level, we provide a framework that articulates two paradigmatic positions underpinning discussions of transparency, verifiability...... with the sharing of information and the perceived quality of the information shared. This narrow focus on information and quality, however, overlooks the dynamics of organizational transparency. To provide a more structured conceptualization of organizational transparency, this article unpacks the assumptions...

  10. Research of detection depth for graphene-based optical sensor

    Science.gov (United States)

    Yang, Yong; Sun, Jialve; Liu, Lu; Zhu, Siwei; Yuan, Xiaocong

    2018-03-01

    Graphene-based optical sensors have been developed for research into the biological intercellular refractive index (RI) because they offer greater detection depths than those provided by the surface plasmon resonance technique. In this Letter, we propose an experimental approach for measurement of the detection depth in a graphene-based optical sensor system that uses transparent polydimethylsiloxane layers with different thicknesses. The experimental results show that detection depths of 2.5 μm and 3 μm can be achieved at wavelengths of 532 nm and 633 nm, respectively. These results prove that graphene-based optical sensors can realize long-range RI detection and are thus promising for use as tools in the biological cell detection field. Additionally, we analyze the factors that influence the detection depth and provide a feasible approach for detection depth control based on adjustment of the wavelength and the angle of incidence. We believe that this approach will be useful in RI tomography applications.

  11. Transparent conductors based on microscale/nanoscale materials for high performance devices

    Science.gov (United States)

    Gao, Tongchuan

    Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), at panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell's equations and Poisson's equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 O/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short

  12. Highly transparent and flexible bio-based polyimide/TiO2 and ZrO2 hybrid films with tunable refractive index, Abbe number, and memory properties.

    Science.gov (United States)

    Huang, Tzu-Tien; Tsai, Chia-Liang; Tateyama, Seiji; Kaneko, Tatsuo; Liou, Guey-Sheng

    2016-07-07

    The novel bio-based polyimide (4ATA-PI) and the corresponding PI hybrids of TiO2 or ZrO2 with excellent optical properties and thermal stability have been prepared successfully. The highly transparent 4ATA-PI containing carboxylic acid groups in the backbone could provide reaction sites for organic-inorganic bonding to obtain homogeneous hybrid films. These PI hybrid films showed a tunable refractive index (1.60-1.81 for 4ATA-PI/TiO2 and 1.60-1.80 for 4ATA-PI/ZrO2), and the 4ATA-PI/ZrO2 hybrid films revealed a higher optical transparency and Abbe's number than those of the 4ATA-PI/TiO2 system due to a larger band gap of ZrO2. By introducing TiO2 and ZrO2 as the electron acceptor into the 4ATA-PI system, the hybrid materials have a lower LUMO energy level which could facilitate and stabilize the charge transfer complex. Therefore, memory devices derived from these PI hybrid films exhibited tunable memory properties from DRAM, SRAM, to WORM with a different TiO2 or ZrO2 content from 0 wt% to 50 wt% with a high ON/OFF ratio (10(8)). In addition, the different energy levels of TiO2 and ZrO2 revealed specifically unique memory characteristics, implying the potential application of the prepared 4ATA-PI/TiO2 and 4ATA-PI/ZrO2 hybrid films in highly transparent memory devices.

  13. Positron annihilation in transparent ceramics

    International Nuclear Information System (INIS)

    Husband, P; Selim, F A; Bartošová, I; Slugeň, V

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics. (paper)

  14. Optical properties and optimization of electromagnetically induced transparency in strained InAs/GaAs quantum dot structures

    DEFF Research Database (Denmark)

    Barettin, D.; Houmark-Nielsen, Jakob; Lassen, B.

    2009-01-01

    Using multiband k center dot p theory we study the size and geometry dependence on the slow light properties of conical semiconductor quantum dots. We find the V-type scheme for electromagnetically induced transparency (EIT) to be most favorable and identify an optimal height and size for efficie...

  15. Transparent mediation-based access to multiple yeast data sources using an ontology driven interface.

    Science.gov (United States)

    Briache, Abdelaali; Marrakchi, Kamar; Kerzazi, Amine; Navas-Delgado, Ismael; Rossi Hassani, Badr D; Lairini, Khalid; Aldana-Montes, José F

    2012-01-25

    Saccharomyces cerevisiae is recognized as a model system representing a simple eukaryote whose genome can be easily manipulated. Information solicited by scientists on its biological entities (Proteins, Genes, RNAs...) is scattered within several data sources like SGD, Yeastract, CYGD-MIPS, BioGrid, PhosphoGrid, etc. Because of the heterogeneity of these sources, querying them separately and then manually combining the returned results is a complex and time-consuming task for biologists most of whom are not bioinformatics expert. It also reduces and limits the use that can be made on the available data. To provide transparent and simultaneous access to yeast sources, we have developed YeastMed: an XML and mediator-based system. In this paper, we present our approach in developing this system which takes advantage of SB-KOM to perform the query transformation needed and a set of Data Services to reach the integrated data sources. The system is composed of a set of modules that depend heavily on XML and Semantic Web technologies. User queries are expressed in terms of a domain ontology through a simple form-based web interface. YeastMed is the first mediation-based system specific for integrating yeast data sources. It was conceived mainly to help biologists to find simultaneously relevant data from multiple data sources. It has a biologist-friendly interface easy to use. The system is available at http://www.khaos.uma.es/yeastmed/.

  16. Continuous production of flexible carbon nanotube-based transparent conductive films

    International Nuclear Information System (INIS)

    Fraser, I Stuart; Windle, Alan H; Motta, Marcelo S; Schmidt, Ron K

    2010-01-01

    This work shows a simple, single-stage, scalable method for the continuous production of high-quality carbon nanotube-polymer transparent conductive films from carbon feedstock. Besides the ease of scalability, a particular advantage of this process is that the concentration of nanotubes in the films, and thus transparency and conductivity, can be adjusted by changing simple process parameters. Therefore, films can be readily prepared for any application desired, ranging from solar cells to flat panel displays. Our best results show a surface resistivity of the order of 300 Ω square -1 for a film with 80% transparency, which is promising at this early stage of process development.

  17. Continuous production of flexible carbon nanotube-based transparent conductive films

    Science.gov (United States)

    Fraser, I. Stuart; Motta, Marcelo S.; Schmidt, Ron K.; Windle, Alan H.

    2010-08-01

    This work shows a simple, single-stage, scalable method for the continuous production of high-quality carbon nanotube-polymer transparent conductive films from carbon feedstock. Besides the ease of scalability, a particular advantage of this process is that the concentration of nanotubes in the films, and thus transparency and conductivity, can be adjusted by changing simple process parameters. Therefore, films can be readily prepared for any application desired, ranging from solar cells to flat panel displays. Our best results show a surface resistivity of the order of 300 Ω square-1 for a film with 80% transparency, which is promising at this early stage of process development.

  18. Nanocellulose reinforcement of Transparent Composites

    Science.gov (United States)

    Joshua Steele; Hong Dong; James F. Snyder; Josh A. Orlicki; Richard S. Reiner; Alan W. Rudie

    2012-01-01

    In this work, we evaluate the impact of nanocellulose reinforcement on transparent composite properties. Due to the small diameter, high modulus, and high strength of cellulose nanocrystals, transparent composites that utilize these materials should show improvement in bulk mechanical performances without a corresponding reduction in optical properties. In this study...

  19. Double-resonance optical-pumping effect and ladder-type electromagnetically induced transparency signal without Doppler background in cesium atomic vapour cell

    International Nuclear Information System (INIS)

    Yang Bao-Dong; Gao Jing; Liang Qiang-Bing; Wang Jie; Zhang Tian-Cai; Wang Jun-Min

    2011-01-01

    In a Doppler-broadened ladder-type cesium atomic system (6S 1/2 -6P 3/2 -8S 1/2 ), this paper characterizes electromagnetically induced transparency (EIT) in two different experimental arrangements, and investigates the influence of the double-resonance optical-pumping (DROP) effect on EIT in both arrangements. When the probe laser is weak, DROP is explicitly suppressed. When the probe laser is moderate, population of the intermediate level (6P 3/2 F' = 5) is remarkable, therefore DROP is mixed with EIT. An interesting bimodal spectrum with the broad component due to DROP and the narrow part due to EIT has been clearly observed in cesium 6S 1/2 F = 4−6P 3/2 F' = 5−8S 1/2 F″ = 4 transitions. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  20. Transparent Pd Wire Network-Based Areal Hydrogen Sensor with Inherent Joule Heater.

    Science.gov (United States)

    Walia, Sunil; Gupta, Ritu; Rao, K D M; Kulkarni, Giridhar U

    2016-09-07

    A high degree of transparency in devices is considered highly desirable for futuristic technology. This demands that both the active material and the electrodes are made of transparent materials. In this work, a transparent Pd wire network (∼1 cm(2)), fabricated using crackle lithography technique with sheet resistance and transmittance of ∼200 Ohm per square and ∼80%, respectively, serves multiple roles; besides being an electrode, it acts as an active material for H2 sensing as well as an in-built electrothermal heater. The sensor works over a wide range of hydrogen (H2) concentration down to 0.02% with a response time of ∼41 s, which could be improved to ∼13 s by in situ Joule heating to ∼75 °C. Importantly, the device has the potential of scale-up to a window size transparent panel and to be flexible when desired.

  1. Transparent Runtime Migration of Loop-Based Traces of Processor Instructions to Reconfigurable Processing Units

    Directory of Open Access Journals (Sweden)

    João Bispo

    2013-01-01

    Full Text Available The ability to map instructions running in a microprocessor to a reconfigurable processing unit (RPU, acting as a coprocessor, enables the runtime acceleration of applications and ensures code and possibly performance portability. In this work, we focus on the mapping of loop-based instruction traces (called Megablocks to RPUs. The proposed approach considers offline partitioning and mapping stages without ignoring their future runtime applicability. We present a toolchain that automatically extracts specific trace-based loops, called Megablocks, from MicroBlaze instruction traces and generates an RPU for executing those loops. Our hardware infrastructure is able to move loop execution from the microprocessor to the RPU transparently, at runtime, and without changing the executable binaries. The toolchain and the system are fully operational. Three FPGA implementations of the system, differing in the hardware interfaces used, were tested and evaluated with a set of 15 application kernels. Speedups ranging from 1.26 to 3.69 were achieved for the best alternative using a MicroBlaze processor with local memory.

  2. A Resource Service Model in the Industrial IoT System Based on Transparent Computing.

    Science.gov (United States)

    Li, Weimin; Wang, Bin; Sheng, Jinfang; Dong, Ke; Li, Zitong; Hu, Yixiang

    2018-03-26

    The Internet of Things (IoT) has received a lot of attention, especially in industrial scenarios. One of the typical applications is the intelligent mine, which actually constructs the Six-Hedge underground systems with IoT platforms. Based on a case study of the Six Systems in the underground metal mine, this paper summarizes the main challenges of industrial IoT from the aspects of heterogeneity in devices and resources, security, reliability, deployment and maintenance costs. Then, a novel resource service model for the industrial IoT applications based on Transparent Computing (TC) is presented, which supports centralized management of all resources including operating system (OS), programs and data on the server-side for the IoT devices, thus offering an effective, reliable, secure and cross-OS IoT service and reducing the costs of IoT system deployment and maintenance. The model has five layers: sensing layer, aggregation layer, network layer, service and storage layer and interface and management layer. We also present a detailed analysis on the system architecture and key technologies of the model. Finally, the efficiency of the model is shown by an experiment prototype system.

  3. Optical transparency and mechanical properties of semi-refined iota carrageenan film reinforced with SiO2 as food packaging material

    Science.gov (United States)

    Aji, Afifah Iswara; Praseptiangga, Danar; Rochima, Emma; Joni, I. Made; Panatarani, Camellia

    2018-02-01

    Food packaging is important for protecting food from environmental influences such as heat, light, water vapor, oxygen, dirt, dust particles, gas emissions and so on, which leads to decrease the quality of food. The most widely used type of packaging in the food industry is plastic which is made from synthetic polymers and takes hundreds of years to biodegrade. Recently, food packaging with high bio-degradability is being developed using biopolymer combined with nanoparticles as reinforcing agent (filler) to improve its properties. In this study, semi-refined iota carrageenan films were prepared by incorporating SiO2 nanoparticles as filler at different concentrations (0%, 0.5%, 1.0% and 1.5% w/w carrageenan) using solution casting method. The optical transparency and mechanical properties (tensile strength and elongation at break) of the films were analyzed. The results showed that incorporation of SiO2 nanoparticles to carrageenan matrix on optical transparency of the films. For the mechanical properties, the highest tensile strength was found for incorporation of 0.5% SiO2, while the elongation at break of the films improved with increasing SiO2 concentration.

  4. The role of air annealing on the optical and scintillation properties of Mg co-doped Pr:LuAG transparent ceramics

    Science.gov (United States)

    Hu, Zewang; Cao, Maoqing; Chen, Haohong; Shi, Yun; Kou, Huamin; Xie, Tengfei; Wu, Lexiang; Pan, Yubai; Feng, Xiqi; Vedda, Anna; Beitlerova, A.; Nikl, M.; Li, Jiang

    2017-10-01

    Polycrystalline 0.2at%Pr:Lu3Al5O12 (Pr:LuAG) transparent ceramics were fabricated by solid-state reaction using 0.01 wt% MgO as sintering aid. The as-sintered ceramics were annealed in air at different temperatures. Optical absorption, photoluminescence, X-ray excited luminescence and pulse height spectra obtained after different annealing were compared. Modifications of the oxygen vacancy concentrations are found to govern the changes of the optical and scintillation response for annealing temperatures lower than 1000 °C, while the oxidation of Pr3+ to Pr4+ plays a more important role for higher temperatures. Air annealing up to 700 °C is an effective tool to improve the 5d-4f emission efficiency of MgO co-doped Pr:LuAG transparent ceramics. The highest radioluminescence intensity is obtained for the 700 °C annealed sample. At variance, higher temperature annealing leads to the deterioration of 5d-4f photoluminescence and scintillation properties because of the self-absorption of Pr4+ and energy transfer from Pr3+ to Pr4+. In addition, we find that the 4f-4f slow emission of ceramics shows different response characteristics under different irradiation sources.

  5. Fiber optic-based biosensor

    Science.gov (United States)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  6. Novel optical password security technique based on optical fractal synthesizer

    Science.gov (United States)

    Wu, Kenan; Hu, Jiasheng; Wu, Xu

    2009-06-01

    A novel optical security technique for safeguarding user passwords based on an optical fractal synthesizer is proposed. A validating experiment has been carried out. In the proposed technique, a user password is protected by being converted to a fractal image. When a user sets up a new password, the password is transformed into a fractal pattern, and the fractal pattern is stored in authority. If the user is online-validated, his or her password is converted to a fractal pattern again to compare with the previous stored fractal pattern. The converting process is called the fractal encoding procedure, which consists of two steps. First, the password is nonlinearly transformed to get the parameters for the optical fractal synthesizer. Then the optical fractal synthesizer is operated to generate the output fractal image. The experimental result proves the validity of our method. The proposed technique bridges the gap between digital security systems and optical security systems and has many advantages, such as high security level, convenience, flexibility, hyper extensibility, etc. This provides an interesting optical security technique for the protection of digital passwords.

  7. Evaluation of Hot Isostatic Pressing Parameters on the Optical and Ballistic Properties of Spinel for Transparent Armor

    Science.gov (United States)

    2006-11-01

    pressing process that is driving the continued interest. Previous work also has identified that hot-pressing followed by hot isostatic pressing...HIPing) is the most promising method for processing transparent spinel4,5. Previous work compared hot-pressing and sintering; the HIP conditions...LITHCO, Bessemer , NC) by shaking with a TURBULA mixer (Glen Mills, Inc., Clifton, NJ) for 60 minutes in a high density polyethylene container. The

  8. Transparent Electrode Based on Silver Nanowires and Polyimide for Film Heater and Flexible Solar Cell

    Directory of Open Access Journals (Sweden)

    Xin He

    2017-11-01

    Full Text Available Transparent, conductive, and flexible Ag nanowire (NW-polyimide (PI composite films were fabricated by a facile solution method. Well-dispersed Ag NWs result in percolation networks on the PI supporting layer. A series of films with transmittance values of 53–80% and sheet resistances of 2.8–16.5 Ω/sq were investigated. To further verify the practicability of the Ag NWs-PI film in optoelectronic devices, we utilized it in a film heater and a flexible solar cell. The film heater was able to generate a temperature of 58 °C at a driving voltage of 3.5 V within 20 s, indicating its potential application in heating devices that require low power consumption and fast response. The flexible solar cell based on the composite film with a transmittance value of 71% presented a power conversion efficiency of 3.53%. These successful applications proved that the fabricated Ag NWs-PI composite film is a good candidate for application in flexible optoelectronic devices.

  9. Transparent Electrode Based on Silver Nanowires and Polyimide for Film Heater and Flexible Solar Cell.

    Science.gov (United States)

    He, Xin; Duan, Feng; Liu, Junyan; Lan, Qiuming; Wu, Jianhao; Yang, Chengyan; Yang, Weijia; Zeng, Qingguang; Wang, Huafang

    2017-11-29

    Transparent, conductive, and flexible Ag nanowire (NW)-polyimide (PI) composite films were fabricated by a facile solution method. Well-dispersed Ag NWs result in percolation networks on the PI supporting layer. A series of films with transmittance values of 53-80% and sheet resistances of 2.8-16.5 Ω/sq were investigated. To further verify the practicability of the Ag NWs-PI film in optoelectronic devices, we utilized it in a film heater and a flexible solar cell. The film heater was able to generate a temperature of 58 °C at a driving voltage of 3.5 V within 20 s, indicating its potential application in heating devices that require low power consumption and fast response. The flexible solar cell based on the composite film with a transmittance value of 71% presented a power conversion efficiency of 3.53%. These successful applications proved that the fabricated Ag NWs-PI composite film is a good candidate for application in flexible optoelectronic devices.

  10. Enhancing the electrical properties of a flexible transparent graphene-based field-effect transistor using electropolished copper foil for graphene growth.

    Science.gov (United States)

    Tsai, Lei-Wei; Tai, Nyan-Hwa

    2014-07-09

    Flexible transparent graphene-based field-effect transistors (Gr-FETs) were fabricated using large-area single-layer graphene synthesized through low-pressure chemical vapor deposition on a pretreated copper (Cu) foil, followed by transfer of the graphene from the Cu foil to a poly(ethylene terephthalate) (PET) substrate. The electropolishing method was adopted to smooth the surface of the Cu foil, which is a crucial factor because it affects the defect density of graphene films on the PET substrate after transfer and the electronic transport property of the graphene-based devices. The influence of the electropolishing process on the graphene properties was examined using a Raman spectroscope, a scanning electron microscope, and an optical microscope. When the electropolishing process was adopted to improve the graphene quality, the carrier mobility of the flexible transparent Gr-FETs was enhanced from 90 to 340 cm(2)/(V s). Furthermore, variation of the carrier mobility was lower than 10% when the bending radius of the flexible device was decreased from 6.0 to 1.0 cm.

  11. Optimization-based adaptive optics for optical coherence tomography

    NARCIS (Netherlands)

    Verstraete, H.R.G.W.

    2017-01-01

    Optical coherence tomography (OCT) is a technique for non-invasive imaging based on low coherence interferometry. Its main application is found in ophthalmology, where it is used for 3D in vivo imaging of the cornea and the retina. OCT has evolved over the past decade as one of the most important

  12. Silicon based ultrafast optical waveform sampling

    DEFF Research Database (Denmark)

    Ji, Hua; Galili, Michael; Pu, Minhao

    2010-01-01

    A 300 nmx450 nmx5 mm silicon nanowire is designed and fabricated for a four wave mixing based non-linear optical gate. Based on this silicon nanowire, an ultra-fast optical sampling system is successfully demonstrated using a free-running fiber laser with a carbon nanotube-based mode-locker as th......A 300 nmx450 nmx5 mm silicon nanowire is designed and fabricated for a four wave mixing based non-linear optical gate. Based on this silicon nanowire, an ultra-fast optical sampling system is successfully demonstrated using a free-running fiber laser with a carbon nanotube-based mode......-locker as the sampling source. A clear eye-diagram of a 320 Gbit/s data signal is obtained. The temporal resolution of the sampling system is estimated to 360 fs....

  13. Optical sensors based on plastic fibers.

    Science.gov (United States)

    Bilro, Lúcia; Alberto, Nélia; Pinto, João L; Nogueira, Rogério

    2012-01-01

    The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this paper, the current state of the art of plastic optical fiber technology will be reviewed, namely its main characteristics and sensing advantages. Several measurement techniques will be described, with a strong focus on interrogation approaches based on intensity variation in transmission and reflection. The potential applications involving structural health monitoring, medicine, environment and the biological and chemical area are also presented.

  14. Optical touch screen based on waveguide sensing

    DEFF Research Database (Denmark)

    Pedersen, Henrik Chresten; Jakobsen, Michael Linde; Hanson, Steen Grüner

    2011-01-01

    We disclose a simple, optical touch screen technique based on a planar injection molded polymer waveguide, a single laser, and a small linear detector array. The solution significantly reduces the complexity and cost as compared to existing optical touch technologies. Force detection of a touching...

  15. Miniaturized optical sensors based on lens arrays

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, M.L.; Larsen, H.E.

    2005-01-01

    A suite of optical sensors based on the use of lenticular arrays for probing mechanical deflections will be displayed. The optical systems are well suited for miniaturization, and utilize speckles as the information-carriers. This implementation allows for acquiring directional information...

  16. Mobile based optical form evaluation system

    Directory of Open Access Journals (Sweden)

    Asım Sinan YÜKSEL

    2016-05-01

    Full Text Available Optical forms that contain multiple-choice answers are widely used both for electing students and evaluating student achievements in education systems in our country and worldwide. Optical forms are evaluated by employing optical mark recognition techniques through optical readers. High cost of these machines, limited access to them, long waiting time for evaluation results make the process hard for educationists working in cities or countries. In this study, a mobile application was developed for the educationists who own mobile phones or tablets for the purpose of evaluating students' answer sheets quickly and independent of location and optical readers. Optical form recognition, reading and evaluation processes are done on the image of student's answer sheet that is taken with the mobile phone or tablet of educationist. The Android based mobile application that we developed has a user-friendly interface, high success rate and is the first of our knowledge application that operates on mobile platforms in this field.

  17. Flexible, transparent and exceptionally high power output nanogenerators based on ultrathin ZnO nanoflakes

    Science.gov (United States)

    van Ngoc, Huynh; Kang, Dae Joon

    2016-02-01

    Novel nanogenerator structures composed of ZnO nanoflakes of less than 10 nm thickness were fabricated using a novel method involving a facile synthetic route and a rational design. The fabricated nanogenerators exhibited a short-circuit current density of 67 μA cm-2, a peak-to-peak open-circuit voltage of 110 V, and an overall output power density exceeding 1.2 mW cm-2, and to the best of our knowledge, these are the best values that have been reported so far in the literature on ZnO-based nanogenerators. We demonstrated that our nanogenerator design could instantaneously power 20 commercial green light-emitting diodes without any additional energy storage processes. Both the facile synthetic route for the ZnO nanoflakes and the straightforward device fabrication process present great scaling potential in order to power mobile and personal electronics that can be used in smart wearable systems, transparent and flexible devices, implantable telemetric energy receivers, electronic emergency equipment, and other self-powered nano/micro devices.Novel nanogenerator structures composed of ZnO nanoflakes of less than 10 nm thickness were fabricated using a novel method involving a facile synthetic route and a rational design. The fabricated nanogenerators exhibited a short-circuit current density of 67 μA cm-2, a peak-to-peak open-circuit voltage of 110 V, and an overall output power density exceeding 1.2 mW cm-2, and to the best of our knowledge, these are the best values that have been reported so far in the literature on ZnO-based nanogenerators. We demonstrated that our nanogenerator design could instantaneously power 20 commercial green light-emitting diodes without any additional energy storage processes. Both the facile synthetic route for the ZnO nanoflakes and the straightforward device fabrication process present great scaling potential in order to power mobile and personal electronics that can be used in smart wearable systems, transparent and flexible

  18. Fiber optic based optical coherence tomography (OCT) for dental applications

    Energy Technology Data Exchange (ETDEWEB)

    Everett, M. J., LLNL

    1998-06-02

    We have developed a hand-held fiber optic based optical coherence tomography (OCT) system for scanning of the oral cavity We have produced, using this scanning device, in viva cross-sectional images of hard and soft dental tissues in human volunteers Clinically relevant anatomical structures, including the gingival margin, periodontal sulcus, and dento-enamel junction, were visible in all the images The dento-enamel junction and the alveolar bone were identifiable in approximately two thirds of the images These images represent, to our knowledge, the first in viva OCT images of human dental tissue.

  19. Multicasting based optical inverse multiplexing in elastic optical network.

    Science.gov (United States)

    Guo, Bingli; Xu, Yingying; Zhu, Paikun; Zhong, Yucheng; Chen, Yuanxiang; Li, Juhao; Chen, Zhangyuan; He, Yongqi

    2014-06-16

    Optical multicasting based inverse multiplexing (IM) is introduced in spectrum allocation of elastic optical network to resolve the spectrum fragmentation problem, where superchannels could be split and fit into several discrete spectrum blocks in the intermediate node. We experimentally demonstrate it with a 1-to-7 optical superchannel multicasting module and selecting/coupling components. Also, simulation results show that, comparing with several emerging spectrum defragmentation solutions (e.g., spectrum conversion, split spectrum), IM could reduce blocking performance significantly but without adding too much system complexity as split spectrum. On the other hand, service fairness for traffic with different granularity of these schemes is investigated for the first time and it shows that IM performs better than spectrum conversion and almost as well as split spectrum, especially for smaller size traffic under light traffic intensity.

  20. Radiation imaging with optically read out GEM-based detectors

    Science.gov (United States)

    Brunbauer, F. M.; Lupberger, M.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

    2018-02-01

    Modern imaging sensors allow for high granularity optical readout of radiation detectors such as MicroPattern Gaseous Detectors (MPGDs). Taking advantage of the high signal amplification factors achievable by MPGD technologies such as Gaseous Electron Multipliers (GEMs), highly sensitive detectors can be realised and employing gas mixtures with strong scintillation yield in the visible wavelength regime, optical readout of such detectors can provide high-resolution event representations. Applications from X-ray imaging to fluoroscopy and tomography profit from the good spatial resolution of optical readout and the possibility to obtain images without the need for extensive reconstruction. Sensitivity to low-energy X-rays and energy resolution permit energy resolved imaging and material distinction in X-ray fluorescence measurements. Additionally, the low material budget of gaseous detectors and the possibility to couple scintillation light to imaging sensors via fibres or mirrors makes optically read out GEMs an ideal candidate for beam monitoring detectors in high energy physics as well as radiotherapy. We present applications and achievements of optically read out GEM-based detectors including high spatial resolution imaging and X-ray fluorescence measurements as an alternative readout approach for MPGDs. A detector concept for low intensity applications such as X-ray crystallography, which maximises detection efficiency with a thick conversion region but mitigates parallax-induced broadening is presented and beam monitoring capabilities of optical readout are explored. Augmenting high resolution 2D projections of particle tracks obtained with optical readout with timing information from fast photon detectors or transparent anodes for charge readout, 3D reconstruction of particle trajectories can be performed and permits the realisation of optically read out time projection chambers. Combining readily available high performance imaging sensors with compatible

  1. HDMI optical extender based on parallel optical transmitter and receiver

    Science.gov (United States)

    Luo, Zhixiang; Zhu, Zhishi; Zhang, Hailiang

    2009-08-01

    High-Definition Multimedia Interface(HDMI) can carry high quality multi-channel audio data and can carry all standard and highdefinition video formats. To send the information form video source to the display unit, the HDMI cable which carries four differential pairs is used. Now HDMI 1.3 increases its single-link bandwidth from 165MHz (4.95 gigabits per second) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices, so the traditional copper wire cable imposes limits on signal transmission distance and signal quality at so high speed. Optical fiber is of low dispersion, which in turn has the strength of longer signal transmission distance and better signal transmission quality in comparison to the traditional copper wire cable. So the optical extender consisting of two modules - one transmitter and one receiver- is developed. The transmitter connects to a computer/DVD player etc. The receiver connects to a display. Between the two modules, four-core ribbon fibre is used to transmit the video and audio signals. HDMI needs four differential pairs, so we design the parallel optical transmitter based on VCSEL array and VCSEL driver chip HXT3404 from Gigoptix and the parallel optical receiver based on PIN array and transimpedance amplifier chip HXR3404. Each channel can reach 3.125Gbps, so the data speed of the optical extender is 12.5Gbps. The experiment shows that the optical extender can transfer the video and audio data to the display uint 100 meter away.

  2. Singly-resonant optical parametric oscillator based on KTA crystal

    Indian Academy of Sciences (India)

    Since the first demonstration of OPO by Giordmaine and Miller in 1965 using. LiNbO3 crystal [1] there has been a lot of improvement in this front making it a real tool for different applications. This becomes possible due to the advent of novel non-linear materials having wide transparency range with very low optical losses,.

  3. On the study of oil paint adhesion on optically transparent glass: Conservation of reverse paintings on glass

    Energy Technology Data Exchange (ETDEWEB)

    Bayle, M. [Historic and Ancient Materials Group, School of Chemistry, University of Lincoln, Brayford Pool, Lincoln LN6 7TS (United Kingdom); Waugh, D.G., E-mail: d.waugh@chester.ac.uk [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Thornton Science Park, Ince, Chester CH2 4NU (United Kingdom); Colston, B.J. [Historic and Ancient Materials Group, School of Chemistry, University of Lincoln, Brayford Pool, Lincoln LN6 7TS (United Kingdom); Lawrence, J. [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Thornton Science Park, Ince, Chester CH2 4NU (United Kingdom)

    2015-12-01

    Highlights: • Adhesion characteristics analysed with respect to reverse paintings on glass. • Physical properties of surfaces and pigments found to affect cohesion and adhesion. • Environmental effects on pigment adhesion to glass have been documented. • Vermillion pigment hardest compared to other pigments, especially with adhesives. • Wettability used to assess adhesion properties relating to reverse paintings on glass. - Abstract: Reverse painting on glass is a technique which consists of applying a cold paint layer on the reverse-side of glass. The main challenge facing these artworks is the fragile adhesion of the pictorial layer – a simple movement can modify the appearance of the painting. This paper details a study into the adhesion parameters of pigments on glass and the comparison between different pigments. The relationships between the binder (linseed oil) with pigments and the glass with or without the use of an adhesive are studied. Physical analyses by surface characterisation have been carried out to better understand the influence of the pigment. The use of a sessile drop device, optical microscopy, scanning electron microscopy (SEM), a surface 3D profiler and a pencil hardness scratch tester were necessary to establish a comparison of the pictorial layer adhesion. A comparison of the effect of two adhesives, namely ox gall and gum arabic, has shown that the adhesion is not only linked to the physical parameters but that possible chemical reactions can influence the results. Finally, a treatment based on humidity-extreme storage has shown the weakness of some pictorial layers.

  4. On the study of oil paint adhesion on optically transparent glass: Conservation of reverse paintings on glass

    International Nuclear Information System (INIS)

    Bayle, M.; Waugh, D.G.; Colston, B.J.; Lawrence, J.

    2015-01-01

    Highlights: • Adhesion characteristics analysed with respect to reverse paintings on glass. • Physical properties of surfaces and pigments found to affect cohesion and adhesion. • Environmental effects on pigment adhesion to glass have been documented. • Vermillion pigment hardest compared to other pigments, especially with adhesives. • Wettability used to assess adhesion properties relating to reverse paintings on glass. - Abstract: Reverse painting on glass is a technique which consists of applying a cold paint layer on the reverse-side of glass. The main challenge facing these artworks is the fragile adhesion of the pictorial layer – a simple movement can modify the appearance of the painting. This paper details a study into the adhesion parameters of pigments on glass and the comparison between different pigments. The relationships between the binder (linseed oil) with pigments and the glass with or without the use of an adhesive are studied. Physical analyses by surface characterisation have been carried out to better understand the influence of the pigment. The use of a sessile drop device, optical microscopy, scanning electron microscopy (SEM), a surface 3D profiler and a pencil hardness scratch tester were necessary to establish a comparison of the pictorial layer adhesion. A comparison of the effect of two adhesives, namely ox gall and gum arabic, has shown that the adhesion is not only linked to the physical parameters but that possible chemical reactions can influence the results. Finally, a treatment based on humidity-extreme storage has shown the weakness of some pictorial layers.

  5. Application of nanostructural materials in electro optical measuring sets of big powers based on usage of optical effects

    Science.gov (United States)

    Salihov, Aidar I.; Tljavlin, Anfar Z.; Kusimov, Salavat M.

    2005-06-01

    Optically transparent nanostructural materials show to themselves a heightened interest owing to display in them the new physic mechanical properties. Variation of structure of the materials received by methods of intensive plastic deformation, results in variation of many fundamental parameters. Among them special interest was caused with variations of fundamental magnetic characteristics. One of them is the magnetization of saturation, which is usually structurally tolerant, but reflects changes in an atomic-crystal structure of solids. Even in the first probing of the transparent nanostructures, received by intensive deformation by torsion of samples, was found that the magnetization of saturation was revealed at room temperature in comparison with coarse-grained samples. High-power measuring devices are based on Faraday effect, representing itself rotation of a plane of polarization of linearly polarized light in optical active substances under action of a magnetic field. Application of nanostructural materials in the optical insulator, which is the main part of the measuring device, allows improving the measuring characteristics of instruments qualitatively. Brought losses in Faraday cell make 0,35 -0,89 dB instead of 0,7 - I,2 dB, and value of the backward losses makes not less than 62 dB instead of 55 dB. Undoubtedly, improvement of the given parameters allows making the measuring operations with the greater accuracy, reducing both absolute, and relative errors.

  6. Fabrication of a transparent conducting electrode based on graphene/silver nanowires via layer-by-layer method for organic photovoltaic devices.

    Science.gov (United States)

    Tugba Camic, B; Oytun, Faruk; Hasan Aslan, M; Jeong Shin, Hee; Choi, Hyosung; Basarir, Fevzihan

    2017-11-01

    A solution-processed transparent conducting electrode was fabricated via layer-by-layer (LBL) deposition of graphene oxide (GO) and silver nanowires (Ag NWs). First, graphite was oxidized with a modified Hummer's method to obtain negatively-charged GO sheets, and Ag NWs were functionalized with cysteamine hydrochloride to acquire positively-charged silver nanowires. Oppositely-charged GO and Ag NWs were then sequentially coated on a 3-aminopropyltriethoxysilane modified glass substrate via LBL deposition, which provided highly controllable thin films in terms of optical transmittance and sheet resistance. Next, the reduction of GO sheets was performed to improve the electrical conductivity of the multilayer films. The resulting GO/Ag NWs multilayer was characterized by a UV-Vis spectrometer, field emission scanning electron microscope (FE-SEM), optical microscope (OM) and sheet resistance using a four-point probe method. The best result was achieved with a 2-bilayer film, resulting in a sheet resistance of 6.5Ω sq -1 with an optical transmittance of 78.2% at 550nm, which values are comparable to those of commercial ITO electrodes. The device based on a 2-bilayer hybrid film exhibited the highest device efficiency of 1.30% among the devices with different number of graphene/Ag NW LBL depositions. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Atomically Bonded Transparent Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL

    2015-08-01

    Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

  8. Conductive bridge random access memory characteristics of SiCN based transparent device due to indium diffusion

    Science.gov (United States)

    Kumar, Dayanand; Aluguri, Rakesh; Chand, Umesh; Tseng, Tseung-Yuen

    2018-03-01

    In this work, the transparent bipolar resistive switching characteristics of a SiCN-based ITO/SiCN/AZO structure due to In diffusion from ITO is studied. The SiCN based device is found to be 80% transparent in the visible wavelength region. This device, with AZO as both top and bottom electrodes, does not show any RRAM property due to deposition of the high quality O2-free SiCN film. Replacing the AZO top electrode with ITO in this device results in good resistive switching (RS) characteristics with a high on/off ratio and long retention. Replacing the SiCN film with ZrO2 also results in excellent RS characteristics due to the formation of an oxygen vacancies filament inside the ZrO2 film. A resistance ratio of on/off is found to be higher in the SiCN based device compared to that of the ZrO2 device. Diffusion of In from ITO into the SiCN film on application of high positive voltage during forming can be attributed to the occurrence of RS in the device, which is confirmed by the analyses of energy dispersive spectroscopy and secondary-ion mass spectrometry. This study shows a pathway for the fabrication of CBRAM based transparent devices for non-volatile memory application.

  9. The effects of transparency on perceived and actual competence of a content-based recommender.

    NARCIS (Netherlands)

    H. Cramer; B. Wielinga; S. Ramlal; V. Evers; L. Rutledge (Lloyd); N. Stash

    2008-01-01

    htmlabstractPerceptions of a system’s competence influence acceptance of that system [31]. Ideally, users’ perception of competence matches the actual competence of a system. This paper investigates the relation between actual and perceived competence of transparent Semantic Web recommender

  10. Direct ink write fabrication of transparent ceramic gain media

    Science.gov (United States)

    Jones, Ivy Krystal; Seeley, Zachary M.; Cherepy, Nerine J.; Duoss, Eric B.; Payne, Stephen A.

    2018-01-01

    Solid-state laser gain media based on the garnet structure with two spatially distinct but optically contiguous regions have been fabricated. Transparent gain media comprised of a central core of Y2.97Nd0.03Al5.00O12.00 (Nd:YAG) and an undoped cladding region of Y3Al5O12 (YAG) were fabricated by direct ink write and transparent ceramic processing. Direct ink write (DIW) was employed to form the green body, offering a general route to preparing functionally structured solid-state laser gain media. Fully-dense transparent optical ceramics in a "top hat" geometry with YAG/Nd:YAG have been fabricated by DIW methods with optical scatter at 1064 nm of <3%/cm.

  11. Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

    Directory of Open Access Journals (Sweden)

    Yongbing Long

    2014-08-01

    Full Text Available Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE polarized and transverse-magnetic(TM polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

  12. Influence of annealing temperature on structural and optical properties of Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} transparent films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Ramírez, Ángel de Jesús [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); García-Murillo, Antonieta, E-mail: angarciam@ipn.mx [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Carrillo-Romo, Felipe de Jesús [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Garrido-Hernández, Aristeo [Instituto Politécnico Nacional, CIITEC IPN, Cerrada de Cecati S/N, 02250 México D.F. (Mexico); Universidad Tecnológica de Tecámac, División de Nanotecnología, Carretera Federal México- Pachuca Km 37.5, Sierra Hermosa, 55740, Edo. De México (Mexico); García-Hernández, Margarita [Universidad Autónoma Metropolitana, Departamento de Ciencias Naturales, Unidad Cuajimalpa, Pedro Antonio de los Santos 84, 11850 México D.F. (Mexico)

    2015-10-15

    Highlights: • Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} films were synthesized by sol–gel and by dip-coating technique. • Effects of annealing treatment on structural and optical properties were studied. • Optogeometrical characteristics of synthesized films were analyzed. • X-ray diffraction results showed that Lu{sub 2}O{sub 3}:Eu{sup 3+}, Tb{sup 3+} crystallizes at 700 °C. • High reddish emission on transparent films with at least 1 μm thick was observed. - Abstract: High-optical quality Lu{sub 2}O{sub 3}:Eu{sup 3+} 5 mol%, X Tb{sup 3+} (X = 0–0.04 mol%) thin films were prepared by the sol–gel process and dip-coating technique. The procedure was as follows: lutetium, europium and terbium nitrates were used as precursors, and ethanol as a solvent. Etylenglycol (EG) was added as a sol stabilizer, and the pH was adjusted by acetic acid. After 10 dipping-cycles, followed by an annealing process (600–900 °C) for 1 h, transparent, smooth and crack-free films (ra = 8–9 nm) were formed. The X-ray diffraction (XRD) results showed crystallized films into the cubic structure at 800 °C. The ellipsometry results showed that the thickness of the films varied from 1 to 1.4 μm at 1000 and 600 °C, respectively. Finally, the films presented a typical Eu{sup 3+} red emission at 611 nm ({sup 5}D{sub 0} → {sup 7}F{sub 2}); furthermore, the effect of the Tb{sup 3+} content showed that the highest emission intensity corresponded to the lower Tb{sup 3+} content.

  13. Photovoltaic cells based on ternary P3HT:PCBM:polymethine dye active layer transparent in the visible range of light

    Energy Technology Data Exchange (ETDEWEB)

    Bliznyuk, Valery N., E-mail: vblizny@clemson.edu [Department of Materials Science and Engineering, Clemson University, Clemson, SC, 29634 (United States); Gasiorowski, Jacek [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Ishchenko, Alexander A.; Bulavko, Gennadiy V. [Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanskaya str., Kiev 02660 (Ukraine); Rahaman, Mahfujur [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Hingerl, Kurt [Center for Interface and Nanoanalytics, Johannes Kepler University, Linz 4040 (Austria); Zahn, Dietrich R.T. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Sariciftci, Niyazi S. [Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz 4040 (Austria)

    2016-12-15

    Highlights: • Addition of a polymethine dye to P3HT:PCBM bulk-heterojunction (BHJ) films leads to a compositionally induced transparency in the system. • Variation of the complex refractive index in binary and ternary BHJ films has been studied with spectroscopic ellipsometry. • Power conversion efficiency of ternary BHJ solar cells is determined by the dye composition and photodoping. - Abstract: Optical and photovoltaic properties were studied for ternary photovoltaic cells containing a traditional donor-acceptor bulk-heterojunction (BHJ) active layer modified with polymethine dye molecules in a broad range of compositions and wavelengths. An effect of composition induced optical transparency, due to the strong modification of the density of states, was observed for symmetrical compositions with approximately equal amount of components. Based on our spectroscopic ellipsometry and atomic force microscopy (AFM) studies we can suggest that the variation of the refractive index, which is significantly reduced in the visible range for ternary systems, is involved in the physical mechanism of the phenomenon. Despite of an addition of the IR absorbing component (which allows broadening of the absorption band to up to 800 nm) no improvement in the power conversion efficiency (PCE) is observed in comparison to the binary BHJ system (P3HT:PCBM). Nevertheless, we believe that further advance of the efficiency will be possible if the energy levels will be chemically designed to avoid formation of charge traps at the BHJ interface during light excitation. Such fine adjustment of the system should become possible with a proper choice of polymer:dye composition due to a high versatility of the polymethine dyes demonstrated in previous studies.

  14. Microcontroller-based locking in optics experiments

    International Nuclear Information System (INIS)

    Huang, K.; Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J.

    2014-01-01

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments

  15. Biaxial crystal-based optical tweezers

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Maksimyak, Andrew P.; Maksimyak, Peter P.

    2010-01-01

    We suggest an optical tweezer setup based on an optically biaxial crystal. To control movements of opaque particles, we use shifts. The results of experimental studies are reported which are concerned with this laser tweezer setup. We demonstrate a movement of microparticles of toner using a sing...... a singular-optical trap, rotation of particles due to orbital angular momentum of the field, and converging or diverging of two different traps when changing transmission plane of polariser at the input of our polarisation interferometer....

  16. Facile Preparation of Carbon-Nanotube-based 3-Dimensional Transparent Conducting Networks for Flexible Noncontact Sensing Device

    KAUST Repository

    Tai, Yanlong

    2016-04-12

    Here, we report the controllable fabrication of transparent conductive films (TCFs) for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS). How baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (> 69 %, PET = 90 %), and good stability when subjected to cyclic loading (> 1000 cycles, better than indium tin oxide film) during processing. Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5×5 sensing pixels).

  17. Optical Ring Resonator Based Temperature Sensor

    Science.gov (United States)

    Addya, Subhankar; Dey, Sabitabrata; Mandal, Sanjoy

    2017-12-01

    Temperature sensor based on optical ring resonator has been demonstrated with its constituent material as silicon (Si-fiber) and germanium (Ge-fiber) in this work. It has been done through optical delay line signal processing technique in Z-domain. The group indices of both the materials vary with the change in temperature due to the thermo-optic effect in materials. Thus temperature dependence of free spectral range forms the basis of modeling the sensors. Silicon (Si) fiber based optical sensor can sense the temperature in the range 30-500 °C and that for germanium (Ge) fiber the range is -25 to 300 °C. Obtained temperature sensitivities for Ge and Si-fibers are 5.55 and 2.97 MHz/°C respectively.

  18. Duality based optical flow algorithms with applications

    DEFF Research Database (Denmark)

    Rakêt, Lars Lau

    We consider the popular TV-L1 optical flow formulation, and the so-called duality based algorithm for minimizing the TV-L1 energy. The original formulation is extended to allow for vector valued images, and minimization results are given. In addition we consider different definitions of total...... variation regularization, and related formulations of the optical flow problem that may be used with a duality based algorithm. We present a highly optimized algorithmic setup to estimate optical flows, and give five novel applications. The first application is registration of medical images, where X...... the motion estimation from the surrounding frames directly to the unknown frame by parametrizing the optical flow objective function such that the interpolation assumption is directly modeled. This reparametrization is a powerful trick that results in a number of appealing properties, in particular...

  19. Effects of in situ plasma treatment on optical and electrical properties of index-matched transparent conducting oxide layer

    International Nuclear Information System (INIS)

    Lim, Yong Hwan; Yoo, Hana; Choi, Bum Ho; Kim, Young Baek; Lee, Jong Ho; Shin, Dong Chan

    2010-01-01

    We investigated the effects of in situ plasma-treatment on optical and electrical properties of index-matched indium tin oxide (IMITO) thin film. To render the IMITO-coated surface hydrophilic and study the optical and electrical characteristics, we performed in situ oxygen plasma post-treatment without breaking vacuum. The 94.6% transmittance in the visible wavelength range (400-700 nm) increased on average to 96.4% and the maximum transmittance reached 98% over a broad wavelength range. The surface roughness and sheet resistance improved from 0.9 nm and 200 Ω/sq to 0.0905 nm and 100 Ω/sq, respectively, by in situ plasma post-treatment. We confirmed by contact angle measurement that the hydrophobic IMITO surface was altered to hydrophilic. The improved optical and electrical characteristics of in situ plasma-treated IMITO makes it adequate for high-resolution liquid crystal on silicon displays.

  20. Development and applications of transparent conductive nanocellulose paper.

    Science.gov (United States)

    Li, Shaohui; Lee, Pooi See

    2017-01-01

    Increasing attention has been paid to the next generation of 'green' electronic devices based on renewable nanocellulose, owing to its low roughness, good thermal stability and excellent optical properties. Various proof-of-concept transparent nanopaper-based electronic devices have been fabricated; these devices exhibit excellent flexibility, bendability and even foldability. In this review, we summarize the recent progress of transparent nanopaper that uses different types of nanocellulose, including pure nanocellulose paper and composite nanocellulose paper. The latest development of transparent and flexible nanopaper electronic devices are illustrated, such as electrochromic devices, touch sensors, solar cells and transistors. Finally, we discuss the advantages of transparent nanopaper compared to conventional flexible plastic substrate and the existing challenges to be tackled in order to realize this promising potential.

  1. Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

    Science.gov (United States)

    Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

    2015-12-01

    Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

  2. Flexible transparent electrodes based on silver nanowires synthesized via a simple method

    Science.gov (United States)

    Li, De; Han, Tao; Zhang, Lei; Zhang, Huai; Chen, Hui

    2017-09-01

    Silver nanowires (Ag NWs) with the length of approximately 60 µm and the diameter of approximately 300 nm are prepared via a simple, cost-effective, high-yield and eco-friendly procedure under a high molar concentration ratio of silver nitrate (AgNO3) solution to poly(vinyl pyrrolidone) solution. The pre-synthesized Ag NWs were analysed by scanning electron microscopy, X-ray diffraction and UV-visible spectrophotometer. Furthermore, the as-prepared silver nanowires were roll-coated on the surfaces of the polyethylene terephthalate (PET) substrates. By optimizing the concentration of silver nanowire solution, the flexible Ag NW/PET transparent electrodes with a sheet resistance of 3.8 Ω sq-1 at a transmittance of 70% can be fabricated. The results reported in this paper provide a basis for optimizing the growth of silver nanowires and performances of transparent electrodes.

  3. Transparency of Computational Intelligence Models

    Science.gov (United States)

    Owotoki, Peter; Mayer-Lindenberg, Friedrich

    This paper introduces the behaviour of transparency of computational intelligence (CI) models. Transparency reveals to end users the underlying reasoning process of the agent embodying CI models. This is of great benefit in applications (e.g. data mining, entertainment and personal robotics) with humans as end users because it increases their trust in the decisions of the agent and their acceptance of its results. Our integrated approach, wherein rules are just one of other transparency factors (TF), differs from previous related efforts which have focused mostly on generation of comprehensible rules as explanations. Other TF include degree of confidence measure and visualization of principal features. The transparency quotient is introduced as a measure of the transparency of models based on these factors. The transparency enabled generalized exemplar model has been developed to demonstrate the TF and transparency concepts introduced in this paper.

  4. Transparent Façade Panel Typologies Based on Recyclable Polymer Materials

    Directory of Open Access Journals (Sweden)

    Harry Giles

    2012-11-01

    Full Text Available Buildings are large consumers of energy. In the United States of America; they constitute over 33% of the total annual energy consumption, produce 35% of the total carbon dioxide emissions and attribute 40% of landfill wastes. The building industry is also a large consumer of non-renewable materials and this trend has escalated dramatically over the past century. It is essential that we find ways to save on energy consumption through the use of solar energy, improved thermal insulation, and alternative efficient glazed façade systems. In this paper, we demonstrate how alternative typologies of transparent and translucent load-bearing façade systems based on biocomposite and recyclable materials, are structurally and thermally efficient at the same time they contribute towards reduced pollutant emissions and non-renewable material uses.Composite insulated panel systems are used extensively in the engineering and building industry, owing to their structural and thermal efficiency. However, these systems are generally opaque and offer little flexibility in building applications. As an alternative, we demonstrate how building products comprised of hybrid material typologie scan be made to perform efficiently as load-bearing façade systems that substitute for current glazing systems with adequate thermal and structural performance, which also possess good light transmission characteristics and integral shading capability. The materials are configured to work as composite panel systems made from a combination of biocomposite and recyclable polymer materials. These materials are environmentally sustainable, because they either originate from naturally grown renewable resources or are recyclable. Our research program includes the design and development of prototype panel systems; the evaluation of structural and thermal performance, together with their role in reducing energy consumption and pollution emission through life cycle analysis. The paper

  5. Transparency International

    NARCIS (Netherlands)

    Hulten, van M. (Michel)

    2009-01-01

    Established in 1993, Transparency International (TI) defines itself as “the global civil society organization leading the fight against corruption, that brings people together in a powerful worldwide coalition to end the devastating impact of corruption on men, women and children around the

  6. Public Transparency

    OpenAIRE

    UNCTAD; World Bank

    2018-01-01

    This note provides guidance on the type of information about agricultural investments that investors and governments can make publicly available. Transparency about certain aspects of investments can improve relations between investors and communities, enable external stakeholders to hold investors to commitments, and improve investors’ public image. Although some information should be kep...

  7. Characterization of imprinted gratings based on transparent materials by transmission scatterometry

    KAUST Repository

    Pietroy, David

    2013-06-01

    Transmission scatterometry is studied as a characterization tool for gratings nanoimprinted in a resist layer spincoated on the top of a transparent substrate. In this case, the larger part of the incident signal is transmitted which can make the reflection analysis harder. Although the backward reflections in the substrate induce an error which is difficult to correct, results are shown to be in good agreement with SEM measurements and reflection mode scatteromerty. © 2013 Elsevier B.V. All rights reserved.

  8. Transparent wood for functional and structural applications

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yang, Xuan; Berglund, Lars

    2017-12-01

    Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  9. Optical-Based Artificial Palpation Sensors for Lesion Characterization

    Directory of Open Access Journals (Sweden)

    Hee-Jun Park

    2013-08-01

    Full Text Available Palpation techniques are widely used in medical procedures to detect the presence of lumps or tumors in the soft breast tissues. Since these procedures are very subjective and depend on the skills of the physician, it is imperative to perform detailed a scientific study in order to develop more efficient medical sensors to measure and generate palpation parameters. In this research, we propose an optical-based, artificial palpation sensor for lesion characterization. This has been developed using a multilayer polydimethylsiloxane optical waveguide. Light was generated at the critical angle to reflect totally within the flexible and transparent waveguide. When a waveguide was compressed by an external force, its contact area would deform and cause the light to scatter. The scattered light was captured by a high-resolution camera and saved as an image format. To test the performance of the proposed system, we used a realistic tissue phantom with embedded hard inclusions. The experimental results show that the proposed sensor can detect inclusions and provide the relative value of size, depth, and Young’s modulus of an inclusion.

  10. Electromagnetically induced transparency in quantum dot systems

    International Nuclear Information System (INIS)

    Jiang Yiwen; Zhu Kadi; Wu Zhuojie; Yuan Xiaozhong; Yao Ming

    2006-01-01

    Electromagnetically induced transparency (EIT) in quantum dot exciton systems in which the exciton behaves as a two-level system is investigated theoretically. It is shown that due to strong exciton-phonon coupling EIT can occur in such a quantum dot system and ultraslow light can propagate. The nonlinear optical absorption and Kerr coefficient based on EIT are also calculated. The numerical results show that giant nonlinear optical effects can be obtained while the frequency of the signal field differs only by an amount of LO phonon frequency from the exciton frequency in quantum dot systems

  11. Time-lens based optical packet pulse compression and retiming

    DEFF Research Database (Denmark)

    Laguardia Areal, Janaina; Hu, Hao; Palushani, Evarist

    2010-01-01

    This paper presents a new optical circuit that performs both pulse compression and frame synchronization and retiming. Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This scheme is optically transparent and does not require clock...... recovery, resulting in a potentially very efficient solution. The scheme uses a time-lens, implemented through a sinusoidally driven optical phase modulation, combined with a linear dispersion element. As time-lenses are also used for pulse compression, we design the circuit also to perform pulse...

  12. Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica

    Directory of Open Access Journals (Sweden)

    Bogdanowicz Robert

    2014-12-01

    Full Text Available Abstract A conductive boron-doped diamond (BDD grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD. The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm-1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.

  13. A high-response transparent heater based on a CuS nanosheet film with superior mechanical flexibility and chemical stability.

    Science.gov (United States)

    Xie, Shuyao; Li, Teng; Xu, Zijie; Wang, Yanan; Liu, Xiangyang; Guo, Wenxi

    2018-04-05

    Transparent heaters are widely used in technologies such as window defrosting/defogging, displays, gas sensing, and medical equipment. Apart from mechanical robustness and electrical and optical reliabilities, outstanding chemical stability is also critical to the application of transparent heaters. In this regard, we first present a highly flexible and large-area CuS transparent heater fabricated by a colloidal crackle pattern method with an optimized sheet resistance (Rs) as low as 21.5 Ω sq-1 at a ∼80% transmittance. The CuS transparent heater exhibits remarkable mechanical robustness during bending tests as well as high chemical stability against acid and alkali environments. In the application as a transparent heater, the CuS heater demonstrates a high thermal resistance of 197 °C W-1 cm2 with a fast switching time (solar panels. These CuS network TCEs with high flexibility, transparency, conductivity, and chemical stability could be widely used in wearable electronic products.

  14. Self-powered flexible and transparent photovoltaic detectors based on CdSe nanobelt/graphene Schottky junctions.

    Science.gov (United States)

    Gao, Zhiwei; Jin, Weifeng; Zhou, Yu; Dai, Yu; Yu, Bin; Liu, Chu; Xu, Wanjin; Li, Yanping; Peng, Hailin; Liu, Zhongfan; Dai, Lun

    2013-06-21

    Flexible and transparent electronic and optoelectronic devices have attracted more and more research interest due to their potential applications in developing portable, wearable, low-cost, and implantable devices. We have fabricated and studied high-performance flexible and transparent CdSe nanobelt (NB)/graphene Schottky junction self-powered photovoltaic detectors for the first time. Under 633 nm light illumination, typical photosensitivity and responsivity of the devices are about 1.2 × 10(5) and 8.7 A W(-1), respectively. Under 3500 Hz switching frequency, the response and recovery times of them are about 70 and 137 μs, respectively, which, to the best of our knowledge, are the best reported values for nanomaterial based Schottky junction photodetectors up to date. The detailed properties of the photodetectors, such as the influences of incident light wavelength and light intensity on the external quantum efficiency and speed, are also investigated. Detailed discussions are made in order to understand the observed phenomena. Our work demonstrates that the self-powered flexible and transparent CdSe NB/graphene Schottky junction photovoltaic detectors have a bright application prospect.

  15. Transparent Wood Smart Windows: Polymer Electrochromic Devices Based on Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) Electrodes.

    Science.gov (United States)

    Lang, Augustus W; Li, Yuanyuan; De Keersmaecker, Michel; Shen, D Eric; Österholm, Anna M; Berglund, Lars; Reynolds, John R

    2018-03-09

    Transparent wood composites, with their high strength and toughness, thermal insulation, and excellent transmissivity, offer a route to replace glass for diffusely transmitting windows. Here, conjugated-polymer-based electrochromic devices (ECDs) that switch on-demand are demonstrated using transparent wood coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a transparent conducting electrode. These ECDs exhibit a vibrant magenta-to-clear color change that results from a remarkably colorless bleached state. Furthermore, they require low energy and power inputs of 3 mWh m -2 at 2 W m -2 to switch due to a high coloration efficiency (590 cm 2  C -1 ) and low driving voltage (0.8 V). Each device component is processed with high-throughput methods, which highlights the opportunity to apply this approach to fabricate mechanically robust, energy-efficient smart windows on a large scale. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  16. Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Besleaga, C.; Stan, G.E.; Pintilie, I. [National Institute of Materials Physics, 405A Atomistilor, 077125 Magurele-Ilfov (Romania); Barquinha, P.; Fortunato, E. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal); Martins, R., E-mail: rm@uninova.pt [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, and CEMOP-UNINOVA, 2829-516 Caparica (Portugal)

    2016-08-30

    Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

  17. Transparent field-effect transistors based on AlN-gate dielectric and IGZO-channel semiconductor

    International Nuclear Information System (INIS)

    Besleaga, C.; Stan, G.E.; Pintilie, I.; Barquinha, P.; Fortunato, E.; Martins, R.

    2016-01-01

    Highlights: • TFTs based on IGZO channel semiconductor and AlN gate dielectric were fabricated. • AlN films – a viable and cheap gate dielectric alternative for transparent TFTs. • Influence of gate dielectric layer thickness on TFTs electrical characteristics. • No degradation of AlN gate dielectric was observed during devices stress testing. - Abstract: The degradation of thin-film transistors (TFTs) caused by the self-heating effect constitutes a problem to be solved for the next generation of displays. Aluminum nitride (AlN) is a viable alternative for gate dielectric of TFTs due to its good thermal conductivity, matching coefficient of thermal expansion to indium–gallium–zinc-oxide, and excellent stability at high temperatures. Here, AlN thin films of different thicknesses were fabricated by a low temperature reactive radio-frequency magnetron sputtering process, using a low cost, metallic Al target. Their electrical properties have been thoroughly assessed. Furthermore, the 200 nm and 500 nm thick AlN layers have been integrated as gate-dielectric in transparent TFTs with indium–gallium–zinc-oxide as channel semiconductor. Our study emphasizes the potential of AlN thin films for transparent electronics, whilst the functionality of the fabricated field-effect transistors is explored and discussed.

  18. Optical and electrical properties of transparent conducting B-doped ZnO thin films prepared by various deposition methods

    Energy Technology Data Exchange (ETDEWEB)

    Nomoto, Jun-ichi; Miyata, Toshihiro; Minami, Tadatsugu [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

    2011-07-15

    B-doped ZnO (BZO) thin films were prepared with various thicknesses up to about 500 nm on glass substrates at 200 deg. C by dc or rf magnetron sputtering deposition, pulsed laser deposition (PLD), and vacuum arc plasma evaporation (VAPE) methods. Resistivities of 4-6 x 10{sup -4}{Omega} cm were obtained in BZO thin films prepared with a B content [B/(B + Zn) atomic ratio] around 1 at. % by PLD and VAPE methods: Hall mobilities above 40 cm{sup 2}/Vs and carrier concentrations on the order of 10{sup 20} cm{sup -3}. All 500-nm-thick-BZO thin films prepared with a resistivity on the order of 10{sup -3}-10{sup -4}{Omega} cm exhibited an averaged transmittance above 80% in the wavelength range of 400-1100 nm. The resistivity in BZO thin films prepared with a thickness below about 500 nm was found to increase over time with exposure to various high humidity environments. In heat-resistance tests, the resistivity stability of BZO thin films was found to be nearly equal to that of Ga-doped ZnO thin films, so these films were judged suitable for use as a transparent electrode for thin-film solar cells.

  19. Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

    Science.gov (United States)

    Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

    2016-01-01

    Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240–260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180–210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time. PMID:26837848

  20. Enhanced protein adsorption and cellular adhesion using transparent titanate nanotube thin films made by a simple and inexpensive room temperature process: application to optical biochips.

    Science.gov (United States)

    Nador, Judit; Orgovan, Norbert; Fried, Miklos; Petrik, Peter; Sulyok, Attila; Ramsden, Jeremy J; Korosi, Laszlo; Horvath, Robert

    2014-10-01

    A new type of titanate nanotube (TNT) coating is investigated for exploitation in biosensor applications. The TNT layers were prepared from stable but additive-free sols without applying any binding compounds. The simple, fast spin-coating process was carried out at room temperature, and resulted in well-formed films around 10nm thick. The films are highly transparent as expected from their nanostructure and may, therefore, be useful as coatings for surface-sensitive optical biosensors to enhance the specific surface area. In addition, these novel coatings could be applied to medical implant surfaces to control cellular adhesion. Their morphology and structure was characterized by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM), and their chemical state by X-ray photoelectron spectroscopy (XPS). For quantitative surface adhesion studies, the films were prepared on optical waveguides. The coated waveguides were shown to still guide light; thus, their sensing capability remains. Protein adsorption and cell adhesion studies on the titanate nanotube films and on smooth control surfaces revealed that the nanostructured titanate enhanced the adsorption of albumin; furthermore, the coatings considerably enhanced the adhesion of living mammalian cells (human embryonic kidney and preosteoblast). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Transparent conductive graphene textile fibers

    Science.gov (United States)

    Neves, A. I. S.; Bointon, T. H.; Melo, L. V.; Russo, S.; de Schrijver, I.; Craciun, M. F.; Alves, H.

    2015-05-01

    Transparent and flexible electrodes are widely used on a variety of substrates such as plastics and glass. Yet, to date, transparent electrodes on a textile substrate have not been explored. The exceptional electrical, mechanical and optical properties of monolayer graphene make it highly attractive as a transparent electrode for applications in wearable electronics. Here, we report the transfer of monolayer graphene, grown by chemical vapor deposition on copper foil, to fibers commonly used by the textile industry. The graphene-coated fibers have a sheet resistance as low as ~1 kΩ per square, an equivalent value to the one obtained by the same transfer process onto a Si substrate, with a reduction of only 2.3 per cent in optical transparency while keeping high stability under mechanical stress. With this approach, we successfully achieved the first example of a textile electrode, flexible and truly embedded in a yarn.

  2. Nanocrystalline Zn{sub 1−x}Mn{sub x}O thin film based transparent Schottky diodes

    Energy Technology Data Exchange (ETDEWEB)

    Gayen, R.N. [Department of Physics, Presidency University, Kolkata 700073 (India); Paul, R., E-mail: rajiv2008juniv@gmail.com [Birck Nanotechnology Center, Purdue University, IN 47907 (United States)

    2016-04-30

    Highly transparent and nanocrystalline Zn{sub 1−x}Mn{sub x}O (x = 0, 0.008, 0.017, 0.046) thin films have been synthesized by sol–gel spin coating technique on glass and SnO{sub 2} coated glass substrates. The microstructural and compositional analyses confirm the incorporation of Mn in hexagonal ZnO lattice without affecting its structure. Zn{sub 1−x}Mn{sub x}O thin films are highly transparent in the visible region of electromagnetic spectrum. The optical band gap, estimated from the transmittance spectra, decreases from 3.32 to 3.21 eV with the increase in Mn content in ZnO films. Photoluminescence study reveals that Mn introduces more defects in ZnO suppressing the excitonic recombination by the defect center (oxygen vacancy) induced recombination. The non-linear current–voltage characteristics at room temperature reveal Schottky barrier junction formation of Zn{sub 1−x}Mn{sub x}O films with Ag. The diode parameters, extracted from the thermionic emission model, vary with Mn incorporation in ZnO. Both the ideality factor and potential barrier height decrease from 6.5 and 0.63 for pure ZnO to 4.7 and 0.54 respectively, for Zn{sub 0.954}Mn{sub 0.046}O film. The series resistance that arises from the defect distributions at the interface and effects the charge transport through the junction, also decreases for higher percentage of Mn in Zn{sub 1−x}Mn{sub x}O thin films. - Highlights: • Mn doped transparent ZnO thin film synthesis using sol–gel spin coating • Particle size and optical band-gap decreases with increasing Mn doping. • Absence of any secondary phase upto 4.6 at.% of Mn which substitutes Zn sites in ZnO lattice • Interesting Schottky diode characteristics with Ag contact • Ideality factor and barrier height decreases with increasing Mn content.

  3. Synthesis and properties of regenerated cellulose-based hydrogels with high strength and transparency for potential use as an ocular bandage

    International Nuclear Information System (INIS)

    Patchan, M.; Graham, J.L.; Xia, Z.; Maranchi, J.P.; McCally, R.; Schein, O.; Elisseeff, J.H.; Trexler, M.M.

    2013-01-01

    Cellulose is a biologically derived material with excellent wound-healing properties. The high strength of cellulose fibers and the ability to synthesize gels with high optical transparency make these materials suitable for ocular applications. In this study, cellulose materials derived from wood pulp, cotton, and bacterial sources were dissolved in lithium chloride/N,N-dimethylacetamide to form regenerated cellulose hydrogels. Material properties of the resulting hydrogels, including water content, optical transparency, and tensile and tear strengths, were evaluated. Synthesis parameters, including activation time, dissolution time, relative humidity, and cellulose concentration, were found to impact the material properties of the resulting hydrogels. Overnight activation time improves the optical transparency of the hydrogels from 77% to 97% at 550 nm, whereas controlling cellulose concentration improves their tear strength by as much as 200%. On the basis of the measured transmittance and strength values of the regenerated hydrogels prepared via the optimized synthesis parameters, Avicel PH 101, Sigma-Aldrich microcrystalline cellulose 435236, and bacterial cellulose types were prioritized for future biocompatibility testing and potential clinical investigation. - Highlights: • Hydrogels were prepared (via LiCl/DMAc) from 7 different types of cellulose. • Synthesis parameters (activation, gelation, and concentration) were optimized. • Impact of synthesis parameters on transparency and strength was explored

  4. Optical computation based on nonlinear total reflectional optical ...

    Indian Academy of Sciences (India)

    All-optical parallel computation is the key technology in all-optical net [1]. It is also the essential part of the optical computer [2]. Optical computing was a hot research field in the 1980s. But this work was not progressed because of material limitations. [3]. It received attention again with its progression in the last decades.

  5. Effect of Chemical Composition on the Optical Properties and Fracture Toughness of Transparent Magnesium Aluminate Spinel Cerami

    Czech Academy of Sciences Publication Activity Database

    Dericioglu, A. F.; Boccaccini, A. R.; Dlouhý, Ivo; Kagawa, Y.

    2005-01-01

    Roč. 46, č. 5 (2005), s. 996-1003 ISSN 1345-9678 R&D Projects: GA AV ČR(CZ) IAA2041003 Institutional research plan: CEZ:AV0Z2041904; CEZ:AV0Z20410507 Keywords : MgAl2O4 spinel * optical properties * fracture toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.103, year: 2005

  6. Bismuth modified physical, structural and optical properties of mid-IR transparent zinc boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, R.S.; Dhankhar, Sunil; Punia, R., E-mail: rajeshpoonia13@gmail.com; Nanda, Kirti; Kishore, N.

    2014-02-25

    Highlights: • Novel materials transmitting in mid-infrared spectral region. • Studied glasses may be good candidates for military and non-linear applications. • Hydrogenic excitonic model is applicable. • Transformation of TeO{sub 4} structural units into TeO{sub 3} units with increase in bismuth content. • B{sub 2}O{sub 3} exists in the both BO{sub 3} trigonal and BO{sub 4} tetrahedral structural units. -- Abstract: Tellurium oxide based quaternary glasses in the system TeO{sub 2}⋅B{sub 2}O{sub 3}⋅Bi{sub 2}O{sub 3}⋅ZnO have been prepared by melt quenching technique. Amorphous nature of the samples has been ascertained by X-ray Diffractogram. The values of density and molar volume increase with increase in Bi{sub 2}O{sub 3} content. Theoretical calculations of crystalline volume (V{sub c}) have also been made. The glass transition temperature (T{sub g}) has been determined using differential scanning calorimetry (DSC) and its value is observed to decrease with increase in Bi{sub 2}O{sub 3} content. IR and Raman spectra of the present glass system indicate that ZnO acts as network modifier and exists in ZnO{sub 4} units. TeO{sub 2} exists as TeO{sub 3}, TeO{sub 4}, and TeO{sub 6} structural units and the number of TeO{sub 4} groups decreases with increase in bismuth content except for the glass sample with x = 5, which shows maximum number of TeO{sub 4} structural units among all other studied glass samples and transformation of some of TeO{sub 4} structural units into TeO{sub 3} structural units is observed with increase in bismuth content. Bismuth plays the role of network modifier with BiO{sub 6} octahedral structural units for glass samples with x = 5, 10, and 15, whereas, exists in network forming BiO{sub 3} pyramidal structural units for glass sample with x = 20. B{sub 2}O{sub 3} exists in the form of BO{sub 3} trigonal and BO{sub 4} tetrahedral structural units. The transmittance of the present glasses is observed to be very high (up to 95

  7. A Non-Ventilated Solar Façade Concept Based on Selective and Transparent Insulation Material Integration: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Miroslav Čekon

    2017-06-01

    Full Text Available A new solar façade concept based on transparent insulation and a selective absorber is proposed, tested and compared with conventional insulation and a non-selective type of absorber, respectively. The presented study focuses on an experimental non-ventilated solar type of façade exposed to solar radiation both in the laboratory and in outdoor tests. Due to the high solar absorbance level of the façade, high- and low-emissivity contributions were primarily analysed. All of the implemented materials were contrasted from the thermal and optical point of view. An analysis was made of both thermodynamic and steady state procedures affecting the proposed solar façade concept. Experimental full scale tests on real building components were additionally involved during summer monitoring. An indicator of the temperature response generated by solar radiation exposure demonstrates the outdoor performance of the façade is closely related to overheating phenomena. From the thermal point of view, the proposed transparent insulation and selective absorber concept corresponds to the performance of conventional thermal insulation of identical material thickness; however, the non-selective prototype only provides 50% thermal performance. The results of the solar-based experiments show that with a small-scale experimental prototype, approximately no significant difference is measured when compared with a non-selective absorber type. The only difference was achieved at the maximum of 2.5 K, when the lower temperature was obtained in the solar selective concept. At the full-scale outdoor mode, the results indicate a maximum of 3.0 K difference, however the lower temperature achieves a non-selective approach. This solar façade can actively contribute to the thermal performance of building components during periods of heating.

  8. Respiration rate detection based on intensity modulation using plastic optical fiber

    Directory of Open Access Journals (Sweden)

    Mohd Anwar Zawawi

    2017-01-01

    Full Text Available This paper presents the implementation of respiration rate measurement via a simple intensity-based optical fiber sensor using optical fiber technology. The breathing rate is measured based on the light intensity variation due to the longitudinal gap changes between two separated fibers. In order to monitor the breathing rate continuously, the output from the photodetector conditioning circuit is connected to a low-cost Arduino kit. At the sensing point, two optical fiber cables are positioned in series with a small gap and fitted inside a transparent plastic tube. To ensure smooth movement of the fiber during inhale and exhale processes as well as to maintain the gap of the fiber during idle condition, the fiber is attached firmly to a stretchable bandage. This study shows that this simple fiber arrangement can be applied to detect respiration activity which might be critical for patient monitoring.

  9. Respiration rate detection based on intensity modulation using plastic optical fiber

    Science.gov (United States)

    Anwar, Zawawi Mohd; Ziran Nurul Sufia, Nor; Hadi, Manap

    2017-11-01

    This paper presents the implementation of respiration rate measurement via a simple intensity-based optical fiber sensor using optical fiber technology. The breathing rate is measured based on the light intensity variation due to the longitudinal gap changes between two separated fibers. In order to monitor the breathing rate continuously, the output from the photodetector conditioning circuit is connected to a low-cost Arduino kit. At the sensing point, two optical fiber cables are positioned in series with a small gap and fitted inside a transparent plastic tube. To ensure smooth movement of the fiber during inhale and exhale processes as well as to maintain the gap of the fiber during idle condition, the fiber is attached firmly to a stretchable bandage. This study shows that this simple fiber arrangement can be applied to detect respiration activity which might be critical for patient monitoring.

  10. Transparency International

    OpenAIRE

    Hulten, van, M. (Michel)

    2009-01-01

    Established in 1993, Transparency International (TI) defines itself as “the global civil society organization leading the fight against corruption, that brings people together in a powerful worldwide coalition to end the devastating impact of corruption on men, women and children around the world”. Its stated goal is “to take action to combat corruption and prevent criminal activities arising from corruption so as to help build a world in which Government, politics, business...

  11. Flexible, Stretchable, and Transparent Planar Microsupercapacitors Based on 3D Porous Laser-Induced Graphene.

    Science.gov (United States)

    Song, Weixing; Zhu, Jianxiong; Gan, Baoheng; Zhao, Shuyu; Wang, Hui; Li, Congju; Wang, Jie

    2018-01-01

    The graphene with 3D porous network structure is directly laser-induced on polyimide sheets at room temperature in ambient environment by an inexpensive and one-step method, then transferred to silicon rubber substrate to obtain highly stretchable, transparent, and flexible electrode of the all-solid-state planar microsupercapacitors. The electrochemical capacitance properties of the graphene electrodes are further enhanced by nitrogen doping and with conductive poly(3,4-ethylenedioxythiophene) coating. With excellent flexibility, stretchability, and capacitance properties, the planar microsupercapacitors present a great potential in fashionable and comfortable designs for wearable electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Optical stimulator for vision-based sensors

    DEFF Research Database (Denmark)

    Rössler, Dirk; Pedersen, David Arge Klevang; Benn, Mathias

    2014-01-01

    stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high......We have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical...... precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations...

  13. Wideband optical vector network analyzer based on optical single-sideband modulation and optical frequency comb.

    Science.gov (United States)

    Xue, Min; Pan, Shilong; He, Chao; Guo, Ronghui; Zhao, Yongjiu

    2013-11-15

    A novel approach to increase the measurement range of the optical vector network analyzer (OVNA) based on optical single-sideband (OSSB) modulation is proposed and experimentally demonstrated. In the proposed system, each comb line in an optical frequency comb (OFC) is selected by an optical filter and used as the optical carrier for the OSSB-based OVNA. The frequency responses of an optical device-under-test (ODUT) are thus measured channel by channel. Because the comb lines in the OFC have fixed frequency spacing, by fitting the responses measured in all channels together, the magnitude and phase responses of the ODUT can be accurately achieved in a large range. A proof-of-concept experiment is performed. A measurement range of 105 GHz and a resolution of 1 MHz is achieved when a five-comb-line OFC with a frequency spacing of 20 GHz is applied to measure the magnitude and phase responses of a fiber Bragg grating.

  14. Novel Transparent Phosphor Conversion Matrix with High Thermal Conductivity for Next Generation Phosphor-Converted LED-based Solid State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Bockstaller, Michael [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-02-06

    The low thermal conductivity of state-of-the-art polymer encapsulants (k ~ 0.15 Wm-1K-1) limits the efficiency and power density of current phosphor conversion light emitting diodes (pc-LEDs). The technical objective of this project was to demonstrate synthesis and processing schemes for the fabrication of polymer hybrid encapsulants with a thermal conductivity exceeding k = 0.4 Wm-1K-1 for LED applications. The ‘hybrid polymer’ approach encompasses the dispersion of high thermal conductivity particle fillers (zinc oxide, ZnO as well as the alpha-polymorph of alumina, Al2O3) within a polysiloxane matrix (poly(dimethylsiloxane), PDMS as well as poly(phenyl methyl siloxane), PPMS) to increase the thermal conductivity while maintaining optical transparency and photothermal stability at levels consistent with LED applications. To accomplish this goal, a novel synthesis method for the fabrication of nanosized ZnO particles was developed and a novel surface chemistry was established to modify the surface of zinc oxide particle fillers and thus to enable their dispersion in poly(dimethyl siloxane) (PDMS) matrix polymers. Molecular dynamics and Mie simulations were used to optimize ligand structure and to enable the concurrent mixing of particles in PDMS/PPMS embedding media while also minimizing the thermal boundary resistance as well as optical scattering of particle fillers. Using this approach the synthesis of PDMS/ZnO hybrid encapsulants exhibiting a thermal conductivity of 0.64 Wm-1K-1 and optical transparency > 0.7 mm-1 was demonstrated. A forming process based on micromolding was developed to demonstrate the forming of particle filled PDMS into film and lens shapes. Photothermal stability testing revealed stability of the materials for approximately 4000 min when exposed to blue light LED (450 nm, 30 W/cm2). One postgraduate and seven graduate students were supported by the project. The research performed within this project led to fifteen publications in peer

  15. Surface Modifier-Free Organic-Inorganic Hybridization to Produce Optically Transparent and Highly Refractive Bulk Materials Composed of Epoxy Resins and ZrO2 Nanoparticles.

    Science.gov (United States)

    Enomoto, Kazushi; Kikuchi, Moriya; Narumi, Atsushi; Kawaguchi, Seigou

    2018-04-02

    Surface modifier-free hybridization of ZrO 2 nanoparticles (NPs) with epoxy-based polymers is demonstrated for the first time to afford highly transparent and refractive bulk materials. This is achieved by a unique and versatile hybridization via the one-pot direct phase transfer of ZrO 2 NPs from water to epoxy monomers without any aggregation followed by curing with anhydride. Three types of representative epoxy monomers, bisphenol A glycidyl ether (BADGE), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate (CEL), and 1,3,5-tris(3-(oxiran-2-yl)propyl)-1,3,5-triazinane-2,4,6-trione (TEPIC) are used to produce transparent viscous dispersions. The resulting ZrO 2 NPs are thoroughly characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), FT-IR, and solid state 13 C CP/MAS NMR measurements. The results from DLS and TEM analyses indicate nanodispersion of ZrO 2 into epoxy monomers as a continuous medium. A surface modification mechanism and the binding fashion during phase transfer are proposed based on the FT-IR and solid state 13 C CP/MAS NMR measurements. Epoxy-based hybrid materials with a high transparency and refractive index are successfully fabricated by heat curing or polymerizing a mixture of monomers containing epoxy-functionalized ZrO 2 NPs and methylhexahydrophthalic anhydride (MHHPA) in the presence of a phosphoric catalyst (PX). The TEM and small-angle X-ray scattering measurements of the hybrids show a nanodispersion of ZrO 2 in the epoxy networks. The refractive index at 594 nm ( n 594 ) increases up to 1.765 for BADGE-based hybrids, 1.667 for CEL-based hybrids, and 1.693 for TEPIC-based hybrids. Their refractive indices and Abbe's numbers are quantitatively described by the Lorentz-Lorenz effective medium expansion theory. Their transmissivity is also reasonably explained using Fresnel refraction, Rayleigh scattering, and the Lambert-Beer theories. This surface modifier-free hybridization provides a

  16. Selectively Transparent and Conducting Photonic Crystals and their Potential to Enhance the Performance of Thin-Film Silicon-Based Photovoltaics and Other Optoelectronic Devices

    Science.gov (United States)

    O'Brien, Paul G.

    2011-12-01

    The byproducts of human engineered energy production are increasing atmospheric CO2 concentrations well above their natural levels and accompanied continual decline in the natural reserves of fossil fuels necessitates the development of green energy alternatives. Solar energy is attractive because it is abundant, can be produced in remote locations and consumed on site. Specifically, thin-film silicon-based photovoltaic (PV) solar cells have numerous inherent advantages including their availability, non-toxicity, and they are relatively inexpensive. However, their low-cost and electrical performance depends on reducing their thickness to as great an extent as possible. This is problematic because their thickness is much less than their absorption length. Consequently, enhanced light trapping schemes must be incorporated into these devices. Herein, a transparent and conducting photonic crystal (PC) intermediate reflector (IR), integrated into the rear side of the cell and serving the dual function as a back-reflector and a spectral splitter, is identified as a promising method of boosting the performance of thin-film silicon-based PV. To this end a novel class of PCs, namely selectively transparent and conducting photonic crystals (STCPC), is invented. These STCPCs are a significant advance over existing 1D PCs because they combine intense wavelength selective broadband reflectance with the transmissive and conductive properties of sputtered ITO. For example, STCPCs are made to exhibit Bragg-reflectance peaks in the visible spectrum of 95% reflectivity and have a full width at half maximum that is greater than 200nm. At the same time, the average transmittance of these STCPCs is greater than 80% over the visible spectrum that is outside their stop-gap. Using wave-optics analysis, it is shown that STCPC intermediate reflectors increase the current generated in micromorph cells by 18%. In comparison, the more conventional IR comprised of a single homogeneous

  17. Chemical bonding in copper-based transparent conducting oxides: CuMO{sub 2} (M = In, Ga, Sc)

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, K G; Morgan, B J; Allen, J P; Scanlon, D O; Watson, G W, E-mail: scanloda@tcd.ie, E-mail: watsong@tcd.ie [School of Chemistry and CRANN, Trinity College Dublin, Dublin 2 (Ireland)

    2011-08-24

    The geometry and electronic structure of copper-based p-type delafossite transparent conducting oxides, CuMO{sub 2} (M = In, Ga, Sc), are studied using the generalized gradient approximation (GGA) corrected for on-site Coulomb interactions (GGA + U). The bonding and valence band compositions of these materials are investigated, and the origins of changes in the valence band features between group 3 and group 13 cations are discussed. Analysis of the effective masses at the valence and conduction band edge explains the experimentally reported conductivity trends.

  18. Flexible optical fiber sensor based on polyurethane

    DEFF Research Database (Denmark)

    Kaysir, Md Rejvi; Stefani, Alessio; Lwin, Richard

    Polyurethane (PU) based hollow core fibers are investigated as optical sensors. The flexibility of PU fibers makes it suitable for sensing mechanical perturbations. We fabricated a PU fiber using the fiber drawing method, characterized the fiber and experimentally demonstrated a simple way...

  19. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  20. Optical voice encryption based on digital holography.

    Science.gov (United States)

    Rajput, Sudheesh K; Matoba, Osamu

    2017-11-15

    We propose an optical voice encryption scheme based on digital holography (DH). An off-axis DH is employed to acquire voice information by obtaining phase retardation occurring in the object wave due to sound wave propagation. The acquired hologram, including voice information, is encrypted using optical image encryption. The DH reconstruction and decryption with all the correct parameters can retrieve an original voice. The scheme has the capability to record the human voice in holograms and encrypt it directly. These aspects make the scheme suitable for other security applications and help to use the voice as a potential security tool. We present experimental and some part of simulation results.

  1. TRANSPARENCY METERS AND GAS ANALYZERS BASED ON TWO-WAVELENGTH SEMICONDUCTOR LASERS

    Directory of Open Access Journals (Sweden)

    V. L. Kozlov

    2011-01-01

    Full Text Available Construction techniques of precision measuring instruments of optical characteristics on the basis of two-wave lasers with use of basic and nephelometer methods are presented. System stability to changes of hardware constants, influence of an environment, pollution of optics is shown. The system automatically takes into account changes of a controllable line length that expands functionalities of a measuring instrument. 

  2. Morphological and optical comparison of the Si doped GaN thin film deposited onto the transparent substrates

    Science.gov (United States)

    Özen, Soner; Şenay, Volkan; Pat, Suat; Korkmaz, Şadan

    2016-04-01

    The aim of this paper is to expand the body of knowledge about the silicon doped gallium nitride thin films deposited on different substrates. The physical properties of the Si doped GaN thin films deposited on the glass and polyethylene terephthalate substrates by thermionic vacuum arc which is plasma production technique were investigated. Thermionic vacuum arc method is a method of producing pure material plasma. The Si doped GaN thin films were analyzed using the following methods and the devices: atomic force microscopy, x-ray diffraction device, spectroscopic ellipsometer and energy dispersive x-ray spectroscopy detector. The produced Si doped GaN thin films are in the (113) orientation. The thicknesses and refractive index were determined by using Cauchy dispersion model. Surface morphologies of produced thin films are homogenous and low roughness. Our analysis showed that the thermionic vacuum arc method present important advantages for optical and industrial applications.

  3. Underwater Object Segmentation Based on Optical Features

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2018-01-01

    Full Text Available Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object of interest, and, therefore, we can initially identify the region of target objects if the collimation of artificial light is recognized. Based on this concept, we propose an optical feature extraction, calculation, and decision method to identify the collimated region of artificial light as a candidate object region. Then, the second phase employs a level set method to segment the objects of interest within the candidate region. This two-phase structure largely removes background noise and highlights the outline of underwater objects. We test the performance of the method with diverse underwater datasets, demonstrating that it outperforms previous methods.

  4. Reset Tree-Based Optical Fault Detection

    Directory of Open Access Journals (Sweden)

    Howon Kim

    2013-05-01

    Full Text Available In this paper, we present a new reset tree-based scheme to protect cryptographic hardware against optical fault injection attacks. As one of the most powerful invasive attacks on cryptographic hardware, optical fault attacks cause semiconductors to misbehave by injecting high-energy light into a decapped integrated circuit. The contaminated result from the affected chip is then used to reveal secret information, such as a key, from the cryptographic hardware. Since the advent of such attacks, various countermeasures have been proposed. Although most of these countermeasures are strong, there is still the possibility of attack. In this paper, we present a novel optical fault detection scheme that utilizes the buffers on a circuit’s reset signal tree as a fault detection sensor. To evaluate our proposal, we model radiation-induced currents into circuit components and perform a SPICE simulation. The proposed scheme is expected to be used as a supplemental security tool.

  5. Understanding the mechanisms leading to failure in metallic nanowire-based transparent heaters, and solution for stability enhancement

    Science.gov (United States)

    Lagrange, M.; Sannicolo, T.; Muñoz-Rojas, D.; Guillo Lohan, B.; Khan, A.; Anikin, M.; Jiménez, C.; Bruckert, F.; Bréchet, Y.; Bellet, D.

    2017-02-01

    Silver nanowire (AgNW) networks are emerging as one of the most promising alternatives to indium tin oxide (ITO) for transparent electrodes in flexible electronic devices. They can be used in a variety of optoelectronic applications such as solar cells, touch panels and organic light-emitting diodes. Recently they have also proven to be very efficient when used as transparent heaters (THs). In addition to the study of AgNW networks acting as THs in regular use, i.e. at low voltage and moderate temperature, their stability and physical behavior at higher voltages and for longer durations should be studied in view of their integration into real devices. The properties of AgNW networks deposited by spray coating on glass or flexible transparent substrates are thoroughly studied via in situ measurements. The AgNW networks’ behavior at different voltages for different durations and under different atmospheric conditions, both in air and under vacuum, has been examined. At low voltage, a reversible electrical response is observed while irreversibility and even failure are observed at higher voltages. In order to gain a deeper insight into the behavior of AgNW networks used as THs, simple but realistic physical models are proposed and are found to be in fair agreement with the experimental data. Finally, as the stability of AgNW networks is a key issue, we demonstrate that coating AgNW networks with a very thin layer of TiO2 using atomic layer deposition (ALD) improves the material’s resistance against electrical and thermal instabilities without altering optical transmittance. We show that the critical annealing temperature associated to network breakdown increases from 270 °C for the as-deposited AgNW networks to 420 °C for AgNW networks coated with TiO2. Similarly, the electrical failure which occurs at 7 V for the as-deposited networks increases to 13 V for TiO2-coated networks. TiO2 is also proved to stabilize AgNW networks during long duration operation and at

  6. Electromagnetically induced transparency metamaterial based on spoof localized surface plasmons at terahertz frequencies

    Science.gov (United States)

    Liao, Zhen; Liu, Shuo; Ma, Hui Feng; Li, Chun; Jin, Biaobing; Cui, Tie Jun

    2016-01-01

    We numerically and experimentally demonstrate a plasmonic metamaterial whose unit cell is composed of an ultrathin metallic disk and four ultrathin metallic spiral arms at terahertz frequencies, which supports both spoof electric and magnetic localized surface plasmon (LSP) resonances. We show that the resonant wavelength is much larger than the size of the unit particle, and further find that the resonant wavelength is very sensitive to the particle’s geometrical dimensions and arrangements. It is clearly illustrated that the magnetic LSP resonance exhibits strong dependence to the incidence angle of terahertz wave, which enables the design of metamaterials to achieve an electromagnetically induced transparency effect in the terahertz frequencies. This work opens up the possibility to apply for the surface plasmons in functional devices in the terahertz band. PMID:27277417

  7. CMOS compatible route for GaAs based large scale flexible and transparent electronics

    KAUST Repository

    Nour, Maha A.

    2014-08-01

    Flexible electronics using gallium arsenide (GaAs) for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. Here we describe a state-of-the-art CMOS compatible batch fabrication process of transforming traditional electronic circuitry into large-area flexible, semitransparent platform. We show a simple release process for peeling off 200 nm of GaAs from 200 nm GaAs/300 nm AlAs stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes which contributes to the better transparency (45 % at 724 nm wavelength) observed.

  8. A neutron scintillator based on transparent nanocrystalline CaF{sub 2}:Eu glass ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Struebing, Christian; Kang, Zhitao, E-mail: zhitao.kang@gtri.gatech.edu [Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Chong, JooYun; Wagner, Brent [Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Lee, Gyuhyon; Ding, Yong [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Zavala, Martin; Erickson, Anna [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Wang, Cai-Lin; Diawara, Yacouba [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6460 (United States); Engels, Ralf [Forschungszentrum Jülich GmbH, Jülich 52425 (Germany)

    2016-04-11

    There are no efficient Eu{sup 2+} doped glass neutron scintillators reported due to low doping concentrations of Eu{sup 2+} and the amorphous nature of the glass matrix. In this work, an efficient CaF{sub 2}:Eu glass ceramic neutron scintillator was prepared by forming CaF{sub 2}:Eu nanocrystals in a {sup 6}Li-containing glass matrix. Through appropriate thermal treatments, the scintillation light yield of the transparent glass ceramic was increased by a factor of at least 46 compared to the as-cast amorphous glass. This improvement was attributed to more efficient energy transfer from the CaF{sub 2} crystals to the Eu{sup 2+} emitting centers. Further light yield improvement is expected if the refractive index of the glass matrix can be matched to the CaF{sub 2} crystal.

  9. High-dynamic-range microscope imaging based on exposure bracketing in full-field optical coherence tomography.

    Science.gov (United States)

    Leong-Hoi, Audrey; Montgomery, Paul C; Serio, Bruno; Twardowski, Patrice; Uhring, Wilfried

    2016-04-01

    By applying the proposed high-dynamic-range (HDR) technique based on exposure bracketing, we demonstrate a meaningful reduction in the spatial noise in image frames acquired with a CCD camera so as to improve the fringe contrast in full-field optical coherence tomography (FF-OCT). This new signal processing method thus allows improved probing within transparent or semitransparent samples. The proposed method is demonstrated on 3 μm thick transparent polymer films of Mylar, which, due to their transparency, produce low contrast fringe patterns in white-light interference microscopy. High-resolution tomographic analysis is performed using the technique. After performing appropriate signal processing, resulting XZ sections are observed. Submicrometer-sized defects can be lost in the noise that is present in the CCD images. With the proposed method, we show that by increasing the signal-to-noise ratio of the images, submicrometer-sized defect structures can thus be detected.

  10. Room temperature transparent conducting oxides based on zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Clatot, J. [Laboratoire de Reactivite et de Chimie des Solides, UMR CNRS 6007, 33, rue Saint-Leu, 80039 Amiens (France); Campet, G. [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB), CNRS, 87 Avenue du Docteur A. Schweitzer, 33608 Pessac Cedex (France); Zeinert, A. [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, 33 rue St. Leu, 80039, Amiens (France); Labrugere, C. [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB), CNRS, 87 Avenue du Docteur A. Schweitzer, 33608 Pessac Cedex (France); Rougier, A., E-mail: aline.rougier@u-picardie.fr [Laboratoire de Reactivite et de Chimie des Solides, UMR CNRS 6007, 33, rue Saint-Leu, 80039 Amiens (France)

    2011-04-01

    Doped zinc oxide thin films are grown on glass substrate at room temperature under oxygen atmosphere, using pulsed laser deposition (PLD). O{sub 2} pressure below 1 Pa leads to conductive films. A careful characterization of the film stoichiometry and microstructure using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) concludes on a decrease in crystallinity with Al and Ga additions ({<=}3%). The progressive loss of the (0 0 2) orientation is associated with a variation of the c parameter value as a function of the film thickness and substrate nature. ZnO:Al and ZnO:Ga thin films show a high optical transmittance (>80%) with an increase in band gap from 3.27 eV (pure ZnO) to 3.88 eV and 3.61 eV for Al and Ga doping, respectively. Optical carrier concentration, optical mobility and optical resistivity are deduced from simulation of the optical data.

  11. Transparent nanostructured cellulose acetate films based on the self assembly of PEO-b-PPO-b-PEO block copolymer.

    Science.gov (United States)

    Gutierrez, Junkal; Carrasco-Hernandez, Sheyla; Barud, Hernane S; Oliveira, Rafael L; Carvalho, Renata A; Amaral, André C; Tercjak, Agnieszka

    2017-06-01

    In this study fabrication and characterization of transparent nanostructured composite films based on cellulose triacetate (CTA) and poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (EPE) triblock copolymer were presented. The effect of the addition of EPE triblock copolymer on the thermal stability, morphology, and mechanical properties of cellulose triacetate films was investigated. The triblock EPE was chosen since PEO blocks interact favorably with CTA, whereas, PPO blocks remain immiscible which provokes a microphase separation. This allows to obtain EPE/CTA composite films with ordered microphase-separated structures where PPO spherical microdomains are well-dispersed in PEO/CTA matrix by simple solvent-evaporation process. During this process, PEO block chains selectively interact with CTA by strong interpolymer hydrogen-bonding while PPO block microseparated. The addition even 40wt% of EPE leads to nanostructured EPE/CTA composite. The cytotoxicity assay of CTA and EPE/CTA composite films confirm non-toxic character of designed transparent nanostructured composites based on sustainable matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Highly transparent Tb3Al5O12 magneto-optical ceramics sintered from co-precipitated powders with sintering aids

    Science.gov (United States)

    Dai, Jiawei; Pan, Yubai; Xie, Tengfei; Kou, Huamin; Li, Jiang

    2018-04-01

    Highly transparent terbium aluminum garnet (Tb3Al5O12, TAG) magneto-optical ceramics were fabricated from co-precipitated nanopowders with tetraethoxysilane (TEOS) as sintering aid by vacuum sintering combined with hot isostatic pressing (HIP) post-treatment. The ball milled TAG powder shows better dispersity than the as-synthesized powder, and its average particle size is about 80 nm. For the ceramic sample pre-sintered at 1720 °C for 20 h with HIP post-treated at 1700 °C for 3 h, the in-line transmittance exceeds 76% in the region of 400-1580nm (except the absorption band), reaching a maximum value of 81.8% at the wavelength of 1390 nm. The microstructure of the TAG ceramic is homogeneous and its average grain size is approximately 19.7 μm. The Verdet constant of the sample is calculated to be -182.7 rad·T-1·m-1 at room temperature.

  13. Optical and electrical properties of transparent conducting gallium-doped ZnO electrodes prepared by atomic layer deposition for application in organic solar cells

    International Nuclear Information System (INIS)

    Song, Yoon Seog; Seong, Nak Jin; Choi, Kyu Jeong; Ryu, Sang Ouk

    2013-01-01

    Transparent and conducting gallium-doped ZnO electrodes were fabricated by means of atomic layer deposition. The electrode showed the lowest resistivity of 7.19 × 10 −4 Ω cm at a 5% cyclic layer deposition ratio of Trimethyl-gallium and Diethyl-zinc chemicals. The electrodes showed minimum resistivity when deposited at a temperature of 250 °C. The electrode also showed optical transmittance of about 82%–89% with film thicknesses between 100 nm and 300 nm. An organic solar cell made with a 300-nm-thick gallium-doped ZnO electrode exhibited 2.5% power conversion efficiency, and an efficiency equivalent to that of cells made with conventional indium tin oxide electrodes. - Highlights: • Ga-doped ZnO thin films were successfully grown by atomic layer deposition • The grown thin film has low resistivity compatible to conventional ITO electrodes • The Ga-doped ZnO films were successfully integrated into organic solar cells • The power conversion efficiency was equivalent to the cells with ITO electrodes

  14. Riboflavin-induced oxidation in fish oil-in-water emulsions: Impact of particle size and optical transparency.

    Science.gov (United States)

    Uluata, Sibel; McClements, D Julian; Decker, Eric A

    2016-12-15

    The influence of particle size and optical properties on the stability of fish oil-in-water emulsions to riboflavin-induced oxidation by blending different combinations of small (d=44nm) and large (d=216nm) lipid droplets was examined. Emulsion turbidity increased with increasing mean droplet diameter due to greater light scattering by larger particles. The influence of droplet size on the stability of the emulsions to riboflavin-induced lipid oxidation during storage at 20 or 37°C was measured. At 37°C, the rate of lipid hydroperoxide formation increased with decreasing droplet diameter, but there were no significant differences in propanal concentrations. At 20°C, both peroxide and propanal values indicated that the rate of oxidation increased with decreasing droplet size. These data show that riboflavin was more effective at promoting oxidation in nanoemulsions containing small droplets because light was able to penetrate more easily and generate reactive oxygen species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. A FRAMEWORK FOR TRANSPARENCY IN INTERNATIONAL TRADE

    Directory of Open Access Journals (Sweden)

    Bernal Turnes, Paloma

    2015-01-01

    Full Text Available The aim of this paper is to cover the gap in literature about transparency in the context of international trade facilitation. It focuses on the importance of transparency in achieving growth in international trade and the differences between non-transparent practices and corruption in global trade. Managing the disclosure of information about rules, regulations and laws is not the only trade policy instrument where transparency becomes important. To build a framework on levels of transparency we developed a matrix classifying the transparency of each country based on ease of doing business and levels of bribery. Four different strategies are explained based on the different scenarios of transparency in international trade. The main conclusions reflect that disclosure of information is not enough to guarantee transparency and monitoring of transparency must be improved.

  16. Lignin-Retaining Transparent Wood.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

    2017-09-11

    Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  17. Tungsten oxide proton conducting films for low-voltage transparent oxide-based thin-film transistors

    International Nuclear Information System (INIS)

    Zhang, Hongliang; Wan, Qing; Wan, Changjin; Wu, Guodong; Zhu, Liqiang

    2013-01-01

    Tungsten oxide (WO x ) electrolyte films deposited by reactive magnetron sputtering showed a high room temperature proton conductivity of 1.38 × 10 −4 S/cm with a relative humidity of 60%. Low-voltage transparent W-doped indium-zinc-oxide thin-film transistors gated by WO x -based electrolytes were self-assembled on glass substrates by one mask diffraction method. Enhancement mode operation with a large current on/off ratio of 4.7 × 10 6 , a low subthreshold swing of 108 mV/decade, and a high field-effect mobility 42.6 cm 2 /V s was realized. Our results demonstrated that WO x -based proton conducting films were promising gate dielectric candidates for portable low-voltage oxide-based devices.

  18. High performance flexible metal oxide/silver nanowire based transparent conductive films by a scalable lamination-assisted solution method

    Directory of Open Access Journals (Sweden)

    Hua Yu

    2017-03-01

    Full Text Available Flexible MoO3/silver nanowire (AgNW/MoO3/TiO2/Epoxy electrodes with comparable performance to ITO were fabricated by a scalable solution-processed method with lamination assistance for transparent and conductive applications. Silver nanoparticle-based electrodes were also prepared for comparison. Using a simple spin-coating and lamination-assisted planarization method, a full solution-based approach allows preparation of AgNW-based composite electrodes at temperatures as low as 140 °C. The resulting flexible AgNW-based electrodes exhibit higher transmittance of 82% at 550 nm and lower sheet resistance about 12–15 Ω sq−1, in comparison with the values of 68% and 22–25 Ω sq−1 separately for AgNP based electrodes. Scanning electron microscopy (SEM and Atomic force microscopy (AFM reveals that the multi-stacked metal-oxide layers embedded with the AgNWs possess lower surface roughness (<15 nm. The AgNW/MoO3 composite network could enhance the charge transport and collection efficiency by broadening the lateral conduction range due to the built of an efficient charge transport network with long-sized nanowire. In consideration of the manufacturing cost, the lamination-assisted solution-processed method is cost-effective and scalable, which is desire for large-area fabrication. While in view of the materials cost and comparable performance, this AgNW-based transparent and conductive electrodes is potential as an alternative to ITO for various optoelectronic applications.

  19. Transparent Ferroelectric Capacitors on Glass

    Directory of Open Access Journals (Sweden)

    Daniele Sette

    2017-10-01

    Full Text Available We deposited transparent ferroelectric lead zirconate titanate thin films on fused silica and contacted them via Al-doped zinc oxide (AZO transparent electrodes with an interdigitated electrode (IDE design. These layers, together with a TiO2 buffer layer on the fused silica substrate, are highly transparent (>60% in the visible optical range. Fully crystallized Pb(Zr0.52Ti0.48O3 (PZT films are dielectrically functional and exhibit a typical ferroelectric polarization loop with a remanent polarization of 15 μC/cm2. The permittivity value of 650, obtained with IDE AZO electrodes is equivalent to the one measured with Pt electrodes patterned with the same design, which proves the high quality of the developed transparent structures.

  20. Transparent Low Molecular Weight Poly(Ethylene Glycol Diacrylate-Based Hydrogels as Film Media for Photoswitchable Drugs

    Directory of Open Access Journals (Sweden)

    Théophile Pelras

    2017-11-01

    Full Text Available Hydrogels have shown a great potential as materials for drug delivery systems thanks to their usually excellent bio-compatibility and their ability to trap water-soluble organic molecules in a porous network. In this study, poly(ethylene glycol-based hydrogels containing a model dye were synthesized by ultraviolet (UV-A photopolymerization of low-molecular weight macro-monomers and the material properties (dye release ability, transparency, morphology, and polymerization kinetics were studied. Real-time infrared measurements revealed that the photopolymerization of the materials was strongly limited when the dye was added to the uncured formulation. Consequently, the procedure was adapted to allow for the formation of sufficiently cured gels that are able to capture and later on to release dye molecules in phosphate-buffered saline solution within a few hours. Due to the transparency of the materials in the 400–800 nm range, the hydrogels are suitable for the loading and excitation of photoactive molecules. These can be uptaken by and released from the polymer matrix. Therefore, such materials may find applications as cheap and tailored materials in photodynamic therapy (i.e., light-induced treatment of skin infections by bacteria, fungi, and viruses using photoactive drugs.

  1. Biometric Image Recognition Based on Optical Correlator

    Directory of Open Access Journals (Sweden)

    David Solus

    2017-01-01

    Full Text Available The aim of this paper is to design a biometric images recognition system able to recognize biometric images-eye and DNA marker. The input scenes are processed by user-friendly software created in C# programming language and then are compared with reference images stored in database. In this system, Cambridge optical correlator is used as an image comparator based on similarity of images in the recognition phase.

  2. Optical fiber-based photomechanical molecular delivery system

    Science.gov (United States)

    Nakano, Koki; Sato, Shunichi; Kawauchi, Satoko; Ashida, Hiroshi; Nishidate, Izumi

    2014-02-01

    Molecular delivery based on nanosecond pulsed laser-induced photomechanical waves (PMWs) enables endoscopic application by using an optical fiber for laser transmission. In our previous fiber system, a laser target, which was a black natural rubber film as a laser absorbing material covered with an optically transparent polyethylene terephthalate disk to confine the laser-induced plasma, was attached to the output end of a 1 mm core diameter quartz fiber. There were two problems in that system: 1) the outer diameter was large (~2.7 mm) and 2) available peak pressure rapidly decreased with increasing pulse number. In this study, we developed a new fiber delivery system to overcome these problems. As a laser absorbing material, we used a cap-type silicone rubber containing carbon black, into which the fiber output end can simply be inserted. The fiber end surface works to confine the laser-induced plasma. The outer diameter of the fiber system was reduced to ~1.4 mm. At an output laser fluence of 1.2 J/cm2, peak pressure of the first PMW pulse exceeded ~40 MPa. With successive 10 laser pulses, decreasing rate of the peak pressure was 22%, which was considerably lower than that with the previous fiber system (82%), enabling generation of at least successive 30 pulses of PMW with the same cap-type target. With this fiber system, we attempted transfer of plasmid DNA encoding EGFP (enhanced green fluorescence protein) to the rat skin as a test tissue in vivo, showing site-selective efficient gene expression.

  3. Metal nanogrids, nanowires, and nanofibers for transparent electrodes

    KAUST Repository

    Hu, Liangbing

    2011-10-01

    Metals possess the highest conductivity among all room-temperature materials; however, ultrathin metal films demonstrate decent optical transparency but poor sheet conductance due to electron scattering from the surface and grain boundaries. This article discusses engineered metal nanostructures in the form of nanogrids, nanowires, or continuous nanofibers as efficient transparent and conductive electrodes. Metal nanogrids are discussed, as they represent an excellent platform for understanding the fundamental science. Progress toward low-cost, nano-ink-based printed silver nanowire electrodes, including silver nanowire synthesis, film fabrication, wire-wire junction resistance, optoelectronic properties, and stability, are also discussed. Another important factor for low-cost application is to use earth-abundant materials. Copper-based nanowires and nanofibers are discussed in this context. Examples of device integrations of these materials are also given. Such metal nanostructure-based transparent electrodes are particularly attractive for solar cell applications. © 2011 Materials Research Society.

  4. Influence of oblique-angle sputtered transparent conducting oxides on performance of Si-based thin film solar cells

    International Nuclear Information System (INIS)

    Leem, Jung Woo; Yu, Jae Su

    2011-01-01

    The transparent conducting oxide (TCO) films with low-refractive-index (low-n) are fabricated by the oblique-angle sputtering method. By using the experimentally measured physical data of the fabricated low-n TCO films as the simulation parameters, the effect of low-n TCOs on the performance of a-Si:H/μc-Si:H tandem thin film solar cells is investigated using Silvaco ATLAS. The Al-doped zinc oxide, indium tin oxide (ITO), and Sb-doped tin oxide films are deposited at the flux incidence angles of θ i = 0 (normal sputtering) and θ i = 80 from the sputtering target during the sputtering process. The oblique-angle sputtered films at θ i = 80 show the inclined columnar nanostructures compared to those at θ i = 0 , modifying the optical properties of the films. This is caused mainly by the increase of porosity within the film which leads to its low-n characteristics. The a-Si:H/μc-Si:H tandem thin film solar cell incorporated with the low-n ITO film exhibits an improvement in the conversion efficiency of ∝1% under AM1.5g illumination because of its higher transmittance and lower absorption compared to that with the ITO film at θ i = 0 , indicating a conversion efficiency of 13.75%. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Influence of oblique-angle sputtered transparent conducting oxides on performance of Si-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Leem, Jung Woo; Yu, Jae Su [Department of Electronics and Radio Engineering, Kyung Hee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2011-09-15

    The transparent conducting oxide (TCO) films with low-refractive-index (low-n) are fabricated by the oblique-angle sputtering method. By using the experimentally measured physical data of the fabricated low-n TCO films as the simulation parameters, the effect of low-n TCOs on the performance of a-Si:H/{mu}c-Si:H tandem thin film solar cells is investigated using Silvaco ATLAS. The Al-doped zinc oxide, indium tin oxide (ITO), and Sb-doped tin oxide films are deposited at the flux incidence angles of {theta}{sub i} = 0 (normal sputtering) and {theta}{sub i} = 80 from the sputtering target during the sputtering process. The oblique-angle sputtered films at {theta}{sub i} = 80 show the inclined columnar nanostructures compared to those at {theta}{sub i} = 0 , modifying the optical properties of the films. This is caused mainly by the increase of porosity within the film which leads to its low-n characteristics. The a-Si:H/{mu}c-Si:H tandem thin film solar cell incorporated with the low-n ITO film exhibits an improvement in the conversion efficiency of {proportional_to}1% under AM1.5g illumination because of its higher transmittance and lower absorption compared to that with the ITO film at {theta}{sub i} = 0 , indicating a conversion efficiency of 13.75%. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Photographic-Based Optical Evaluation of Tissues and Biomaterials Used for Corneal Surface Repair: A New Easy-Applied Method.

    Directory of Open Access Journals (Sweden)

    Miguel Gonzalez-Andrades

    Full Text Available Tissues and biomaterials used for corneal surface repair require fulfilling specific optical standards prior to implantation in the patient. However, there is not a feasible evaluation method to be applied in clinical or Good Manufacturing Practice settings. In this study, we describe and assess an innovative easy-applied photographic-based method (PBM for measuring functional optical blurring and transparency in corneal surface grafts.Plastic compressed collagen scaffolds (PCCS and multilayered amniotic membranes (AM samples were optically and histologically evaluated. Transparency and image blurring measures were obtained by PBM, analyzing photographic images of a standardized band pattern taken through the samples. These measures were compared and correlated to those obtained applying the Inverse Adding-Doubling (IAD technique, which is the gold standard method.All the samples used for optical evaluation by PBM or IAD were histological suitable. PCCS samples presented transmittance values higher than 60%, values that increased with increasing wavelength as determined by IAD. The PBM indicated that PCCS had a transparency ratio (TR value of 80.3 ± 2.8%, with a blurring index (BI of 50.6 ± 4.2%. TR and BI obtained from the PBM showed a high correlation (ρ>|0.6| with the diffuse transmittance and the diffuse reflectance, both determined using the IAD (p<0.005. The AM optical properties showed that there was a largely linear relationship between the blurring and the number of amnion layers, with more layers producing greater blurring.This innovative proposed method represents an easy-applied technique for evaluating transparency and blurriness of tissues and biomaterials used for corneal surface repair.

  7. Sintering, Thermal Conductivity, Optical and Lasing Properties of Doped-Lu2O3 Fiberous Transparent Ceramics

    Science.gov (United States)

    2016-02-26

    specimens with Yb2O3 contents from 0 to 8 mol% are shown in Figure 9. Spectra were normalized to a thickness of 1.462 mm based on the Beer - Lambert law , and...Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law , no person shall be subject to any penalty for failing...GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) Robert F. Speyer, Professor, School of Materials Science and Engineering 5d. PROJECT NUMBER

  8. A new method for obtaining transparent electrodes

    DEFF Research Database (Denmark)

    Malureanu, Radu; Zalkovskij, Maksim; Song, Zhengyong

    2012-01-01

    In this article, we propose a simple scheme to make a metallic film on a semi-infinite substrate optically transparent, thus obtaining a completely transparent electrode in a desired frequency range. By placing a composite layer consisting of dielectric and metallic stripes on top of the metallic...

  9. Optically Transparent Cathode for Dye-Sensitized Solar Cells Based on Graphene Nanoplatelets

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Yum, J. H.; Graetzel, M.

    2011-01-01

    Roč. 5, č. 1 (2011), s. 165-172 ISSN 1936-0851 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400804; GA AV ČR KAN200100801 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * dye sensitized solar cells * electrochemical impendance Subject RIV: CG - Electrochemistry Impact factor: 10.774, year: 2011

  10. Advanced Waveguide Lasers Based on Optically Transparent Polycrystalline Materials for Power Scaling Studies

    Science.gov (United States)

    2015-02-20

    propagation length (high-gain and high-efficiency). Fig 1. Design of a waveguide sample. A slab sample with the dimension (62 x...16 x 1.2mmt) as the waveguide sample was prepared by bonding in the middle of the slab and tested for high power laser experiment. When the absorbed...composite sample may be cracked . Therefore, it is important to develop powders with similar shrinkage behavior although they have different chemical

  11. Advanced Optical Signal Processing using Time Lens based Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Lillieholm, Mads

    2016-01-01

    An overview of recent progress on time lens based advanced optical signal processing is presented, with a special focus on all-optical ultrafast 640 Gbit/s all-channel serial-to-parallel conversion, and scalable WDM regeneration....

  12. Carbon nanotube-graphene composite film as transparent conductive electrode for GaN-based light-emitting diodes

    KAUST Repository

    Kang, Chun Hong

    2016-08-23

    Transparent conductive electrodes (TCE) made of carbon nanotube (CNT) and graphene composite for GaN-based light emitting diodes (LED) are presented. The TCE with 533-Ω/□ sheet resistance and 88% transmittance were obtained when chemical-vapor-deposition grown graphene was fused across CNT networks. With an additional 2-nm thin NiOx interlayer between the TCE and top p-GaN layer of the LED, the forward voltage was reduced to 5.12 V at 20-mA injection current. Four-fold improvement in terms of light output power was observed. The improvement can be ascribed to the enhanced lateral current spreading across the hybrid CNT-graphene TCE before injection into the p-GaN layer.

  13. Hollow Few-Layer Graphene-Based Structures from Parafilm Waste for Flexible Transparent Supercapacitors and Oil Spill Cleanup.

    Science.gov (United States)

    Nguyen, Duc Dung; Hsieh, Ping-Yen; Tsai, Meng-Ting; Lee, Chi-Young; Tai, Nyan-Hwa; To, Bao Dong; Vu, Duc Tu; Hsu, Chia Chen

    2017-11-22

    We report a versatile strategy to exploit parafilm waste as a carbon precursor for fabrication of freestanding, hollow few-layer graphene fiber mesh (HFGM) structures without use of any gaseous carriers/promoters via an annealing route. The freestanding HFGMs possess good mechanical flexibility, tailorable transparency, and high electrical conductivity, consequently qualifying them as promising electrochemical electrodes. Because of the hollow spaces, electrolyte ions can easily access into and contact with interior surfaces of the graphene fibers, accordingly increasing electrode/electrolyte interfacial area. As expected, solid-state supercapacitors based on the HFGMs exhibit a considerable enhancement in specific capacitance (20-30 fold) as compared to those employing chemical vapor deposition compact graphene films. Moreover, the parafilm waste is found to be beneficial for one-step fabrication of nanocarbon/few-layer graphene composite meshes with superior electrochemical performance, outstanding superhydrophobic property, good self-cleaning ability, and great promise for oil spill cleanup.

  14. Transparent 3D display for augmented reality

    Science.gov (United States)

    Lee, Byoungho; Hong, Jisoo

    2012-11-01

    Two types of transparent three-dimensional display systems applicable for the augmented reality are demonstrated. One of them is a head-mounted-display-type implementation which utilizes the principle of the system adopting the concave floating lens to the virtual mode integral imaging. Such configuration has an advantage in that the threedimensional image can be displayed at sufficiently far distance resolving the accommodation conflict with the real world scene. Incorporating the convex half mirror, which shows a partial transparency, instead of the concave floating lens, makes it possible to implement the transparent three-dimensional display system. The other type is the projection-type implementation, which is more appropriate for the general use than the head-mounted-display-type implementation. Its imaging principle is based on the well-known reflection-type integral imaging. We realize the feature of transparent display by imposing the partial transparency to the array of concave mirror which is used for the screen of reflection-type integral imaging. Two types of configurations, relying on incoherent and coherent light sources, are both possible. For the incoherent configuration, we introduce the concave half mirror array, whereas the coherent one adopts the holographic optical element which replicates the functionality of the lenslet array. Though the projection-type implementation is beneficial than the head-mounted-display in principle, the present status of the technical advance of the spatial light modulator still does not provide the satisfactory visual quality of the displayed three-dimensional image. Hence we expect that the head-mounted-display-type and projection-type implementations will come up in the market in sequence.

  15. Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.......Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  16. Modulatable optical radiators and metasurfaces based on quantum nanoantennas

    KAUST Repository

    Chen, Pai-Yen

    2015-01-20

    We investigate the tunable and switchable optical radiators and metamaterials formed by metallic nanodipole antennas with submicroscopic gaps (1.2 nm), of which linear and third-order nonlinear quantum conductivities are observed due to the photon-assisted tunneling effect. The quantum conductivities induced at the nanogap are relevant to power dissipations, which can be enhanced by the strongly localized optical fields associated with the plasmonic resonance. We demonstrate that the scattering property of an individual quantum nanoantenna and the transparency of a metamasurface constituted of it can be tuned by electrostatically controlling the linear conductivity (electronic tuning) or by adjusting the irradiation intensity that varies the nonlinear quantum conductivity (all-optical tuning).

  17. Electrically Tunable Metamaterials Based on Multimaterial Nanowires Incorporating Transparent Conductive Oxides.

    Science.gov (United States)

    Salary, Mohammad Mahdi; Mosallaei, Hossein

    2017-08-30

    We present novel design approaches for metasurfaces and metamaterials with electrical tunability offering real-time manipulation of light and serving as multifunctional devices in near-infrared frequency regime (at the specific wavelength of 1.55 μm). For this purpose, we integrate indium-tin-oxide (ITO) as a tunable electro-optical material into multimaterial nanowires with metal-oxide-semiconductor and metal-insulator-metal configurations. In particular, an active metasurface operating in the transmission mode is designed which allows for modulation of the transmitted light phase over 280 degrees. This large phase modulation is afforded in the cost of low transmission efficiency. We demonstrate the use of such active metasurfaces for tunable bending and focusing in free-space. Moreover, we investigate the implementation of this material in deeply subwavelength multimaterial nanowires, which can yield strong variations in the effective refractive index by the virtue of internal homogenization enabling tunability of the performance in gradient refractive index metamaterials. In the theoretical modeling of these structures, we adopt a hierarchical multiscale approach by linking drift-diffusion transport model with the electromagnetic model which rigorously characterizes the electro-optical effects.

  18. Environmental stability of high-mobility indium-oxide based transparent electrodes

    Directory of Open Access Journals (Sweden)

    Thanaporn Tohsophon

    2015-11-01

    Full Text Available Large-scale deployment of a wide range of optoelectronic devices, including solar cells, critically depends on the long-term stability of their front electrodes. Here, we investigate the performance of Sn-doped In2O3 (ITO, H-doped In2O3 (IO:H, and Zn-doped In2O3 (IZO electrodes under damp heat (DH conditions (85 °C, 85% relative humidity. ITO, IO:H capped with ITO, and IZO show high stability with only 3%, 9%, and 13% sheet resistance (Rs degradation after 1000 h of DH, respectively. For uncapped IO:H, we find a 75% Rs degradation, due to losses in electron Hall mobility (μHall. We propose that this degradation results from chemisorbed OH- or H2O-related species in the film, which is confirmed by thermal desorption spectroscopy and x-ray photoelectron spectroscopy. While μHall strongly degrades during DH, the optical mobility (μoptical remains unchanged, indicating that the degradation mainly occurs at grain boundaries.

  19. All-optical signal processing of OTDM and OFDM signals based on time-domain optical fourier transformation

    DEFF Research Database (Denmark)

    Galili, Michael; Guan, Pengyu; Lillieholm, Mads

    2017-01-01

    In the talk, we will review recent work on optical signal processing based on time lenses. Various applications of optical Fourier transformation for optical communications will be discussed.......In the talk, we will review recent work on optical signal processing based on time lenses. Various applications of optical Fourier transformation for optical communications will be discussed....

  20. Knowledge-based optical system design: some optical systems generated by the KBOSD

    Science.gov (United States)

    Nouri, Taoufik; Erard, Pierre-Jean

    1993-04-01

    This work is a new approach for the design of start optical systems and represents a new contribution of artificial intelligence techniques in the optical design field. A knowledge-based optical-systems design (KBOSD), based on artificial intelligence algorithms, first order logic, knowledge representation, rules, and heuristics on lens design, is realized. This KBOSD is equipped with optical knowledge in the domain of centered dioptrical optical systems used at low aperture and small field angles. This KBOSD generates centered dioptrical, on-axis and low-aperture optical-systems, which are used as start systems for the subsequent optimization by existing lens design programs. This KBOSD produces monochromatic or polychromatic optical systems, such as singlet lens, doublet lens, triplet lens, reversed singlet lens, reversed doublet lens, reversed triplet lens, and telescopes. In the design of optical systems, the KBOSD takes into account many user constraints such as cost, resistance of the optical material (glass) to chemical, thermal, and mechanical effects, as well as the optical quality such as minimal aberrations and chromatic aberrations corrections. This KBOSD is developed in the programming language Prolog and has knowledge on optical design principles and optical properties and uses neither a lens library nor a lens data base, it is completely based on optical design knowledge.

  1. Wave-mixing-induced transparency with zero phase shift in atomic vapors

    Science.gov (United States)

    Zhou, F.; Zhu, C. J.; Li, Y.

    2017-12-01

    We present a wave-mixing induced transparency that can lead to a hyper-Raman gain-clamping effect. This new type of transparency is originated from a dynamic gain cancellation effect in a multiphoton process where a highly efficient light field of new frequency is generated and amplified. We further show that this novel dynamic gain cancellation effect not only makes the medium transparent to a probe light field at appropriate frequency but also eliminates the probe field propagation phase shift. This gain-cancellation-based induced transparency holds for many potential applications on optical communication and may lead to effective suppression of parasitic Raman/hyper-Raman noise field generated in high intensity optical fiber transmissions.

  2. Active microring based tunable optical power splitters

    Science.gov (United States)

    Peter, Eldhose; Thomas, Arun; Dhawan, Anuj; Sarangi, Smruti R.

    2016-01-01

    In this paper we propose a set of novel tunable optical power splitters based on active microring resonators. They work by operating ring resonators in the transient zone between full resonance and off-resonance states for a specific wavelength. We can achieve different split ratios by either varying the bias voltage, or by selectively enabling a given resonator with a specific split ratio among an array of ring resonators. We take 500 ps to tune the resonator, which is at least 10× better that competing designs. Its split ratio varies from 0.4 to 1.8 for an applied voltage range of 0-5 V.

  3. Optical Properties of Bismuth Tellurite Based Glass

    Science.gov (United States)

    Oo, Hooi Ming; Mohamed-Kamari, Halimah; Wan-Yusoff, Wan Mohd Daud

    2012-01-01

    A series of binary tellurite based glasses (Bi2O3)x (TeO2)100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases. PMID:22605999

  4. Optical Properties of Bismuth Tellurite Based Glass

    Directory of Open Access Journals (Sweden)

    Hooi Ming Oo

    2012-04-01

    Full Text Available A series of binary tellurite based glasses (Bi2O3x (TeO2100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO. The Fourier transform infrared spectroscopy (FTIR results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases.

  5. ITO-Free Solution-Processed Flexible Electrochromic Devices Based on PEDOT:PSS as Transparent Conducting Electrode.

    Science.gov (United States)

    Singh, Rekha; Tharion, Joseph; Murugan, Sengottaiyan; Kumar, Anil

    2017-06-14

    Electrochromic devices (ECDs) are emerging as novel technology for various applications ranging from commercialized smart window glasses, goggles, and autodimming rear view mirrors to uncommon yet more sophisticated applications such as infrared camouflage in military and thermal control in space satellites. The development of low-power, lightweight, inexpensive, and flexible devices is the need of the hour. In this respect, utilizing PEDOT:PSS as transparent conducting electrode (TCE) to replace indium tin oxide (ITO) and metal based TCEs for ECDs is a promising solution for the aforementioned requirements. In this work we have demonstrated the performance of PEDOT:PSS films coated on flexible substrates, treated with PTSA-DMSO, as TCEs for ECD applications and their comparison with that of ITO based ECDs. The PEDOT:PSS based flexible TCEs used in this study have conductivity of 1400-1500 S·cm -1 and figure of merit (FoM) of 70-77. The process of increasing the conductivity of PEDOT:PSS films also led to the broadening of the conducting potential window (CPW), which is important for electrochemical applications of PEDOT:PSS when used as a stand-alone electrode. More than achieving a comparable electrochromic contrast, switching time, and coloration efficiency with respect to the ITO based ECDs, PEDOT:PSS devices also had the added advantage of good mechanical flexibility. These devices demonstrated superior stability during electrochemical cycling and multiple mechanical bending tests, making them an inexpensive alternative to the costly ITO based ECD technology.

  6. Electromagnetically induced transparency in 6Li

    International Nuclear Information System (INIS)

    Fuchs, J; Duffy, G J; Rowlands, W J; Akulshin, A M

    2006-01-01

    We report electromagnetically induced transparency for the D1 and D2 lines in 6 Li in both a vapour cell and an atomic beam. Electromagnetically induced transparency is created using copropagating mutually coherent laser beams with a frequency difference equal to the hyperfine ground state splitting of 228.2 MHz. The effects of various optical polarization configurations and applied magnetic fields are investigated. In addition, we apply an optical Ramsey spectroscopy technique which further reduces the observed resonance width

  7. Optical measuring system with an interrogator and a polymer-based single-mode fibre optic sensor system

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to an optical measuring system comprising a polymer-based single-mode fibre-optic sensor system (102), an optical interrogator (101), and an optical arrangement (103) interconnecting the optical interrogator (101) and the polymer-based single-mode fibre-optic sensor...... system (102). The invention further relates to an optical interrogator adapted to be connected to a polymer-based single-mode fibre-optic sensor system via an optical arrangement. The interrogator comprises a broadband light source arrangement (104) and a spectrum analysing arrangement which receives...... and analyses light reflected from the polymer-based single- mode fibre-optic sensor system....

  8. Roll-to-roll-compatible, flexible, transparent electrodes based on self-nanoembedded Cu nanowires using intense pulsed light irradiation

    Science.gov (United States)

    Zhong, Zhaoyang; Woo, Kyoohee; Kim, Inhyuk; Hwang, Hyewon; Kwon, Sin; Choi, Young-Man; Lee, Youngu; Lee, Taik-Min; Kim, Kwangyoung; Moon, Jooho

    2016-04-01

    Copper nanowire (Cu NW)-based flexible transparent conductive electrodes (FTCEs) have been investigated in detail for use in various applications such as flexible touch screens, organic photovoltaics and organic light-emitting diodes. In this study, hexadecylamine (HDA) adsorbed onto the surface of NWs is changed into polyvinylpyrrolidone (PVP) via a ligand exchange process; the high-molecular-weight PVP enables high dispersion stability. Intense pulsed light (IPL) irradiation is used to remove organic species present on the surface of the NWs and to form direct connections between the NWs rapidly without any atmospheric control. NWs are self-nanoembedded into a plastic substrate after IPL irradiation, which results in a smooth surface, strong NW/substrate adhesion, excellent mechanical flexibility and enhanced oxidation stability. Moreover, Cu NW FTCEs with high uniformities are successfully fabricated on a large area (150 mm × 200 mm) via successive IPL irradiation that is synchronized with the motion of the sample stage. This study demonstrates the possibility of roll-to-roll-based, large-scale production of low-cost, high-performance Cu NW-based FTCEs.Copper nanowire (Cu NW)-based flexible transparent conductive electrodes (FTCEs) have been investigated in detail for use in various applications such as flexible touch screens, organic photovoltaics and organic light-emitting diodes. In this study, hexadecylamine (HDA) adsorbed onto the surface of NWs is changed into polyvinylpyrrolidone (PVP) via a ligand exchange process; the high-molecular-weight PVP enables high dispersion stability. Intense pulsed light (IPL) irradiation is used to remove organic species present on the surface of the NWs and to form direct connections between the NWs rapidly without any atmospheric control. NWs are self-nanoembedded into a plastic substrate after IPL irradiation, which results in a smooth surface, strong NW/substrate adhesion, excellent mechanical flexibility and enhanced

  9. Polyethylene laser welding based on optical absorption variations

    Science.gov (United States)

    Galtieri, G.; Visco, A.; Nocita, D.; Torrisi, L.; Ceccio, G.; Scolaro, C.

    2016-04-01

    Polymeric materials, both pure and containing nanostructures, can be prepared as thin sheets in order to produce joints with an interface between an optically transparent sheet and an optically absorbent substrate to be welded by infrared pulsed laser irradiation. The Laser Transmission Welding (LTW) technique has been successfully applied in order to join two or more thermoplastic polymeric sheets that must have a similar chemical composition. In this research work, polymeric joints of Ultra High Molecular Weight Polyethylene sheets were realized, characterized and welded. Some polymer sheets were doped, at different concentrations, with carbon nano-particles absorbent the laser radiation. A pulsed laser operating in the wavelength region 532 nm with intensity of the order of 109 Watt/cm2 was employed to be transmitted by the transparent polymer and to be absorbed by the carbon enriched surface. At the interface of the two polymers the released energy induces melting, that is assisted by pressure, producing a fast and resistant welding zone. Mechanical and optical characterizations and surface analyses are presented and discussed.

  10. Optical/Infrared Signatures for Space-Based Remote Sensing

    National Research Council Canada - National Science Library

    Picard, R. H; Dewan, E. M; Winick, J. R; O'Neil, R. R

    2007-01-01

    This report describes work carried out under the Air Force Research Laboratory's basic research task in optical remote-sensing signatures, entitled Optical / Infrared Signatures for Space-Based Remote Sensing...

  11. Toward transparent and self-activated graphene harmonic transponder sensors

    Science.gov (United States)

    Huang, Haiyu Harry; Sakhdari, Maryam; Hajizadegan, Mehdi; Shahini, Ali; Akinwande, Deji; Chen, Pai-Yen

    2016-04-01

    We propose the concept and design of a transparent, flexible, and self-powered wireless sensor comprising a graphene-based sensor/frequency-modulator circuitry and a graphene antenna. In this all-graphene device, the multilayered-graphene antenna receives the fundamental tone at C band and retransmits the frequency-modulated sensed signal (harmonic tone) at X band. The frequency orthogonality between the received/re-transmitted signals may enable high-performance sensing in severe interference/clutter background. Here, a fully passive, quad-ring frequency multiplier is proposed using graphene field-effect transistors, of which the unique ambipolar charge transports render a frequency doubling effect with conversion gain being chemically sensitive to exposed gas/molecular/chemical/infectious agents. This transparent, light-weight, and self-powered system may potentially benefit a number of wireless sensing and diagnosis applications, particularly for smart contact lenses/glasses and microscope slides that require high optical transparency.

  12. Applications and Optimization of Optical Time Lenses based on Four-Wave Mixing in Highly Nonlinear Fibre

    DEFF Research Database (Denmark)

    Lillieholm, Mads

    2017-01-01

    Optical Fourier transformations enabled by the versatile time lens (quadratic phase modulator), have been demonstrated for numerous optical signal processing applications. Applications include ultrafast optical oscilloscopes, high resolution spectralanalysers, and the processing of ultrahigh......-speed communication signals, to enable e.g. such varied applications as phase regeneration for wavelength-division multiplexing (WDM) signals, conversion between spectrally efficient formats and receivers with reduced complexity for advanced optical multiplexing formats. Four-wave mixing (FWM) is showing promise...... as a method to implement time lenses, for its ability to impart a parabolic phase profile with high fidelity, and to transparently process and preserve arbitrary amplitude and phase information at ultrahigh data rates. Many time lens demonstrations have been based on FWM with linearly chirped pump pulses...

  13. Stability analysis in a ROADM-based multi-channel quasi-ring optical network

    Science.gov (United States)

    Tsai, Jimmy; Wang, Zheng; Pan, Yan; Kilper, Daniel C.; Pavel, Lacra

    2015-01-01

    Future networks require dynamic physical layer capabilities to enable rapid and on-demand reconfiguration, while ensuring stability. This paper addresses stability analysis of a ROADM-based quasi-ring optical network. A ROADM-based quasi-ring is the simplest configuration in which channel power excursions can self-propagate indefinitely and be unstable. This network configuration is composed of two reconfigurable optical add-drop multiplexers (ROADMs) each equipped with a constant gain optical amplifier and a wavelength selective switch. Over the amplified spans, two sets of lightpaths (added/dropped by opposite ROADMs) are transmitted in mirror image of each other and form an overlapping ring. Sufficient stability conditions for the quasi-ring as well as an L2 bound for the channel power excursions are derived based on Lyapunov analysis and the small gain theorem. These conditions are functions of the amplifier gain coupling quantified by its Lipschitz constant. Numerical results that verify and compare the theoretical results are provided. The platform used is Bell Lab's A Transparent Optical Mesh (ATOM) simulator, set up for dynamic network loading and input channel disturbance scenarios.

  14. Optical conductivity of iron-based superconductors.

    Science.gov (United States)

    Charnukha, A

    2014-06-25

    The new family of unconventional iron-based superconductors discovered in 2006 immediately relieved their copper-based high-temperature predecessors as the most actively studied superconducting compounds in the world. The experimental and theoretical effort made in order to unravel the mechanism of superconductivity in these materials has been overwhelming. Although our understanding of their microscopic properties has been improving steadily, the pairing mechanism giving rise to superconducting transition temperatures up to 55 K remains elusive. And yet the hope is strong that these materials, which possess a drastically different electronic structure but similarly high transition temperatures compared to the copper-based compounds, will shed essential new light onto the several-decade-old problem of unconventional superconductivity. In this work we review the current understanding of the itinerant-charge-carrier dynamics in the iron-based superconductors and parent compounds largely based on the optical conductivity data the community has gleaned over the past seven years using such experimental techniques as reflectivity, ellipsometry, and terahertz transmission measurements and analyze the implications of these studies for the microscopic properties of the iron-based materials as well as the mechanism of superconductivity therein.

  15. Optical conductivity of iron-based superconductors

    International Nuclear Information System (INIS)

    Charnukha, A

    2014-01-01

    The new family of unconventional iron-based superconductors discovered in 2006 immediately relieved their copper-based high-temperature predecessors as the most actively studied superconducting compounds in the world. The experimental and theoretical effort made in order to unravel the mechanism of superconductivity in these materials has been overwhelming. Although our understanding of their microscopic properties has been improving steadily, the pairing mechanism giving rise to superconducting transition temperatures up to 55 K remains elusive. And yet the hope is strong that these materials, which possess a drastically different electronic structure but similarly high transition temperatures compared to the copper-based compounds, will shed essential new light onto the several-decade-old problem of unconventional superconductivity. In this work we review the current understanding of the itinerant-charge-carrier dynamics in the iron-based superconductors and parent compounds largely based on the optical-conductivity data the community has gleaned over the past seven years using such experimental techniques as reflectivity, ellipsometry, and terahertz transmission measurements and analyze the implications of these studies for the microscopic properties of the iron-based materials as well as the mechanism of superconductivity therein. (topical review)

  16. Retina image–based optic disc segmentation

    Directory of Open Access Journals (Sweden)

    Ching-Lin Wang

    2016-05-01

    Full Text Available The change of optic disc can be used to diagnose many eye diseases, such as glaucoma, diabetic retinopathy and macular degeneration. Moreover, retinal blood vessel pattern is unique for human beings even for identical twins. It is a highly stable pattern in biometric identification. Since optic disc is the beginning of the optic nerve and main blood vessels in retina, it can be used as a reference point of identification. Therefore, optic disc segmentation is an important technique for developing a human identity recognition system and eye disease diagnostic system. This article hence presents an optic disc segmentation method to extract the optic disc from a retina image. The experimental results show that the optic disc segmentation method can give impressive results in segmenting the optic disc from a retina image.

  17. High Mobility of Graphene-Based Flexible Transparent Field Effect Transistors Doped with TiO2 and Nitrogen-Doped TiO2.

    Science.gov (United States)

    Wu, Yu-Hsien; Tseng, Po-Yuan; Hsieh, Ping-Yen; Chou, Hung-Tao; Tai, Nyan-Hwa

    2015-05-13

    Graphene with carbon atoms bonded in a honeycomb lattice can be tailored by doping various species to alter the electrical properties of the graphene for fabricating p-type or n-type field-effect transistors (FETs). In this study, large-area and single-layer graphene was grown on electropolished Cu foil using the thermal chemical vapor deposition method; the graphene was then transferred onto a poly(ethylene terephthalate) (PET) substrate to produce flexible, transparent FETs. TiO2 and nitrogen-doped TiO2 (N-TiO2) nanoparticles were doped on the graphene to alter its electrical properties, thereby enhancing the carrier mobility and enabling the transistors to sense UV and visible light optically. The results indicated that the electron mobility of the graphene was 1900 cm(2)/(V·s). Dopings of TiO2 and N-doped TiO2 (1.4 at. % N) lead to n-type doping effects demonstrating extremely high carrier mobilities of 53000 and 31000 cm(2)/(V·s), respectively. Through UV and visible light irradiation, TiO2 and N-TiO2 generated electrons and holes; the generated electrons transferred to graphene channels, causing the FETs to exhibit n-type electric behavior. In addition, the Dirac points of the graphene recovered to their original state within 5 min, confirming that the graphene-based FETs were photosensitive to UV and visible light. In a bending state with a radius of curvature greater than 2.0 cm, the carrier mobilities of the FETs did not substantially change, demonstrating the application possibility of the fabricated graphene-based FETs in photosensors.

  18. Fiber optic-based regenerable biosensor

    Science.gov (United States)

    Sepaniak, Michael J.; Vo-Dinh, Tuan

    1993-01-01

    A fiber optic-based regenerable biosensor. The biosensor is particularly suitable for use in microscale work in situ. In one embodiment, the biosensor comprises a reaction chamber disposed adjacent the distal end of a waveguide and adapted to receive therein a quantity of a sample containing an analyte. Leading into the chamber is a plurality of capillary conduits suitable for introducing into the chamber antibodies or other reagents suitable for selective interaction with a predetermined analyte. Following such interaction, the contents of the chamber may be subjected to an incident energy signal for developing fluorescence within the chamber that is detectable via the optical fiber and which is representative of the presence, i.e. concentration, of the selected analyte. Regeneration of the biosensor is accomplished by replacement of the reagents and/or the analyte, or a combination of these, at least in part via one or more of the capillary conduits. The capillary conduits extend from their respective terminal ends that are in fluid communication with the chamber, away from the chamber to respective location(s) remote from the chamber thereby permitting in situ location of the chamber and remote manipulation and/or analysis of the activity with the chamber.

  19. Silicon-Chip-Based Optical Frequency Combs

    Science.gov (United States)

    2015-10-26

    microresonator,” Phys. Rev. Lett. 107, 063901 (2011). [54] H. Jung, et al., “Optical frequency comb generation from aluminum nitride microring resonator...supercontinuum generation in silicon nitride waveguides. 15. SUBJECT TERMS Nonlinear optics, parametric mixing, nanophotonics, optical frequency combs 16...Finally, we investigated comb generation via coherent supercontinuum generation in silicon nitride waveguides. Our research effort illustrates that the

  20. All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

    Science.gov (United States)

    Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

    2011-11-21

    We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. © 2011 Optical Society of America

  1. Novel Ethernet Based Optical Local Area Networks for Computer Interconnection

    NARCIS (Netherlands)

    Radovanovic, Igor; van Etten, Wim; Taniman, R.O.; Kleinkiskamp, Ronny

    2003-01-01

    In this paper we present new optical local area networks for fiber-to-the-desk application. Presented networks are expected to bring a solution for having optical fibers all the way to computers. To bring the overall implementation costs down we have based our networks on short-wavelength optical

  2. Flexible Transparent Films Based on Nanocomposite Networks of Polyaniline and Carbon Nanotubes for High-Performance Gas Sensing.

    Science.gov (United States)

    Wan, Pengbo; Wen, Xuemei; Sun, Chaozheng; Chandran, Bevita K; Zhang, Han; Sun, Xiaoming; Chen, Xiaodong

    2015-10-28

    A flexible, transparent, chemical gas sensor is assembled from a transparent conducting film of carbon nanotube (CNT) networks that are coated with hierarchically nanostructured polyaniline (PANI) nanorods. The nanocomposite film is synthesized by in-situ, chemical oxidative polymerization of aniline in a functional multiwalled CNT (FMWCNT) suspension and is simultaneously deposited onto a flexible polyethylene terephthalate (PET) substrate. An as-prepared flexible transparent chemical gas sensor exhibits excellent transparency of 85.0% at 550 nm using the PANI/FMWCNT nanocomposite film prepared over a reaction time of 8 h. The sensor also shows good flexibility, without any obvious decrease in performance after 500 bending/extending cycles, demonstrating high-performance, portable gas sensing at room temperature. This superior performance could be attributed to the improved electron transport and collection due to the CNTs, resulting in reliable and efficient sensing, as well as the high surface-to-volume ratio of the hierarchically nanostructured composites. The excellent transparency, improved sensing performance, and superior flexibility of the device, may enable the integration of this simple, low-cost, gas sensor into handheld flexible transparent electronic circuitry and optoelectronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Reconfigurable Optical Signal Processing Based on a Distributed Feedback Semiconductor Optical Amplifier.

    Science.gov (United States)

    Li, Ming; Deng, Ye; Tang, Jian; Sun, Shuqian; Yao, Jianping; Azaña, José; Zhu, Ninghua

    2016-01-27

    All-optical signal processing has been considered a solution to overcome the bandwidth and speed limitations imposed by conventional electronic-based systems. Over the last few years, an impressive range of all-optical signal processors have been proposed, but few of them come with reconfigurability, a feature highly needed for practical signal processing applications. Here we propose and experimentally demonstrate an analog optical signal processor based on a phase-shifted distributed feedback semiconductor optical amplifier (DFB-SOA) and an optical filter. The proposed analog optical signal processor can be reconfigured to perform signal processing functions including ordinary differential equation solving and temporal intensity differentiation. The reconfigurability is achieved by controlling the injection currents. Our demonstration provitdes a simple and effective solution for all-optical signal processing and computing.

  4. Reconfigurable Optical Signal Processing Based on a Distributed Feedback Semiconductor Optical Amplifier

    Science.gov (United States)

    Li, Ming; Deng, Ye; Tang, Jian; Sun, Shuqian; Yao, Jianping; Azaña, José; Zhu, Ninghua

    2016-01-01

    All-optical signal processing has been considered a solution to overcome the bandwidth and speed limitations imposed by conventional electronic-based systems. Over the last few years, an impressive range of all-optical signal processors have been proposed, but few of them come with reconfigurability, a feature highly needed for practical signal processing applications. Here we propose and experimentally demonstrate an analog optical signal processor based on a phase-shifted distributed feedback semiconductor optical amplifier (DFB-SOA) and an optical filter. The proposed analog optical signal processor can be reconfigured to perform signal processing functions including ordinary differential equation solving and temporal intensity differentiation. The reconfigurability is achieved by controlling the injection currents. Our demonstration provitdes a simple and effective solution for all-optical signal processing and computing. PMID:26813252

  5. Optical Biosensors Based on Semiconductor Nanostructures

    Directory of Open Access Journals (Sweden)

    Raúl J. Martín-Palma

    2009-06-01

    Full Text Available The increasing availability of semiconductor-based nanostructures with novel and unique properties has sparked widespread interest in their use in the field of biosensing. The precise control over the size, shape and composition of these nanostructures leads to the accurate control of their physico-chemical properties and overall behavior. Furthermore, modifications can be made to the nanostructures to better suit their integration with biological systems, leading to such interesting properties as enhanced aqueous solubility, biocompatibility or bio-recognition. In the present work, the most significant applications of semiconductor nanostructures in the field of optical biosensing will be reviewed. In particular, the use of quantum dots as fluorescent bioprobes, which is the most widely used application, will be discussed. In addition, the use of some other nanometric structures in the field of biosensing, including porous semiconductors and photonic crystals, will be presented.

  6. Transparent and Stretchable High-Performance Supercapacitors Based on Wrinkled Graphene Electrodes

    Science.gov (United States)

    2013-12-18

    High-Performance Supercapacitors Based onWrinkledGraphene Electrodes Tao Chen,† Yuhua Xue,† Ajit K. Roy,‡ and Liming Dai†,* †Center of Advanced Science...batteries,4 and textile super- capacitors,7 have been developed to retain their functions even when they were under large strains (up to 40%). Along... electrodes and the associated supercapacitor cells cannot be both trans- parent and stretchable.1318 It is highly desirable to integrate the

  7. Flexible transparent electrode

    Science.gov (United States)

    Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

    2011-06-01

    This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

  8. Wearable Electricity Generators Fabricated Utilizing Transparent Electronic Textiles Based on Polyester/Ag Nanowires/Graphene Core-Shell Nanocomposites.

    Science.gov (United States)

    Wu, Chaoxing; Kim, Tae Whan; Li, Fushan; Guo, Tailiang

    2016-07-26

    The technological realization of wearable triboelectric generators is attractive because of their promising applications in wearable self-powered intelligent systems. However, the low electrical conductivity, the low electrical stability, and the low compatibility of current electronic textiles (e-textiles) and clothing restrict the comfortable and aesthetic integration of wearable generators into human clothing. Here, we present high-performance, transparent, smart e-textiles that employ commercial textiles coated with silver nanowire/graphene sheets fabricated by using a scalable, environmentally friendly, full-solution process. The smart e-textiles show superb and stable conduction of below 20 Ω/square as well as excellent flexibility, stretchability, foldability, and washability. In addition, wearable electricity-generating textiles, in which the e-textiles act as electrodes as well as wearable substrates, are presented. Because of the high compatibility of smart e-textiles and clothing, the electricity-generating textiles can be easily integrated into a glove to harvest the mechanical energy induced by the motion of the fingers. The effective output power generated by a single generator due to that motion reached as high as 7 nW/cm(2). The successful demonstration of the electricity-generating glove suggests a promising future for polyester/Ag nanowire/graphene core-shell nanocomposite-based smart e-textiles for real wearable electronic systems and self-powered clothing.

  9. Infrared/submillimeter optical properties data base

    Science.gov (United States)

    Alley, Phillip W.

    1989-01-01

    The general goal was to build a data base containing optical properties, such as reflectance, transmittance, refractive index, in the far infrared to submillimeter wavelength region. This data base would be limited to selected crystalline materials and temperature between 300 and 2 K. The selected materials were: lithium, lead, and strontium; the bromides of potassium and thallium; the carbides of silicone and tungsten; and the materials of KRS5, KRS6, diamond, and sapphire. Last summer, barium fluoride was selected as prototype material for building the data base. This summer the literature search, preparation of the data for barium fluoride was completed. In addition the literature search for data related to the compounds mentioned was completed. The current status is that barium fluoride is in a form suitable for a NASA internal publication. The papers containing the data on the other materials were xeroxed and they are ready to be reduced. On the reverse side, the top figure is a sample combination of data for the index of refraction at 300 K. The lower figure shows the transmittance vs wavelength at 300 and 80 K. These figures are a sample of many which were developed. Since barium fluoride was studied more than most of the materials listed above, it is clear that additional measurements should be made to fill in the gaps present on both temperature and wavelength data.

  10. Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.

    Science.gov (United States)

    Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo

    2017-07-19

    Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.

  11. Key Topics in Producing New Ultraviolet Led and Laser Devices Based on Transparent Semiconductor Zinc Oxide

    International Nuclear Information System (INIS)

    Tuezemen, S.

    2004-01-01

    Recently, it has been introduced that ZnO as II-VI semiconductor is promising various technological applications, especially for optoelectronic short wavelength light emitting devices due to its wide and direct band gap profile. The most important advantage of ZnO over the other currently used wide band gap semiconductors such as GaN is that its nearly 3 times higher exciton binding energy (60 meV), which permits efficient excitonic emission at room temperature and above. As-grown ZnO is normally n-type because of the Zn-rich defects such as zinc interstitials (Zn i ) oxygen vacancies (Vo), natively acting as shallow donors and main source of n-type conductivity in as-grown material. Therefore, making p-type ZnO has been more difficult due to unintentional compensation of possible acceptors by these residual donors. In order to develop electro luminescent and laser devices based on the ultraviolet (UV) exciton emission of ZnO, it will be important to fabricate good p-n junctions. Attempts to observe p-type conductivity in ours and our collaborators' laboratories in USA, either by co-doping with N or tuning O pressure have been first successful achievements, resulting in hole concentrations up to 10 1 9 cm - 3 in reactively sputtered thin layers of ZnO. Moreover, in order to produce ZnO based quantum well lasers similar to the previously introduced n-AlGaAs/GaAs/p-AlGaAs structures; we have attempted to grow Zn 1 -xSn x O thin films to enlarge the band gap energy. An increase up to 170 meV has been observed in Zn 1 -xSn x O thin films and this is enough barrier to be able to trap electron-hole pairs in quantum well structures. As a result, two important key issues; p-type conductivity and enhancement of the band gap energy in order to step forward towards the production of electro luminescent UV LEDs and quantum well lasers have been investigated and will be presented in this study

  12. Temperature-controlled transparent-film heater based on silver nanowire-PMMA composite film

    Science.gov (United States)

    He, Xin; Liu, A.'lei; Hu, Xuyang; Song, Mingxia; Duan, Feng; Lan, Qiuming; Xiao, Jundong; Liu, Junyan; Zhang, Mei; Chen, Yeqing; Zeng, Qingguang

    2016-11-01

    We fabricated a high-performance film heater based on a silver nanowire and polymethyl methacrylate (Ag NW-PMMA) composite film, which was synthesized with the assistance of mechanical lamination and an in situ transfer method. The films exhibit excellent conductivity, high figure of merit, and strong adhesion of percolation network to substrate. By controlling NW density, we prepared the films with a transmittance of 44.9-85.0% at 550 nm and a sheet resistance of 0.13-1.40 Ω sq-1. A stable temperature ranging from 130 °C-40 °C was generated at 3.0 V within 10-30 s, indicating that the resulting film heaters show a rapid thermal response, low driving voltage and stable temperature recoverability. Furthermore, we demonstrated the applications of the film heater in defrosting and a physical therapeutic instrument. A fast defrosting on the composite film with a transmittance of 88% was observed by applying a 9 V driving voltage for 20 s. Meanwhile, we developed a physical therapeutic instrument with two modes of thermotherapy and electronic-pulse massage by using the composite films as two electrodes, greatly decreasing the weight and power consumption compared to a traditional instrument. Therefore, Ag NW-PMMA film can be a promising candidate for diversified heating applications.

  13. All-optical VPN utilizing DSP-based digital orthogonal filters access for PONs

    Science.gov (United States)

    Zhang, Xiaoling; Zhang, Chongfu; Chen, Chen; Jin, Wei; Qiu, Kun

    2018-04-01

    Utilizing digital filtering-enabled signal multiplexing and de-multiplexing, a cost-effective all-optical virtual private network (VPN) system is proposed, for the first time to our best knowledge, in digital filter multiple access passive optical networks (DFMA-PONs). Based on the DFMA technology, the proposed system can be easily designed to meet the requirements of next generation network's flexibility, elasticity, adaptability and compatibility. Through dynamic digital filter allocation and recycling, the proposed all-optical VPN system can provide dynamic establishments and cancellations of multiple VPN communications with arbitrary traffic volumes. More importantly, due to the employment of DFMA technology, the system is not limited to a fixed signal format and different signal formats such as pulse amplitude modulation (PAM), quadrature amplitude modulation (QAM) and orthogonal frequency division multiplexing (OFDM) can be used. Moreover, one transceiver is sufficient to simultaneously transmit upstream (US)/VPN data to optical line terminal (OLT) or other VPN optical network units (ONUs), thus leading to great reduction in network constructions and operation expenditures. The proposed all-optical VPN system is demonstrated with the transceiver incorporating the formats of QAM and OFDM, which can be made transparent to downstream (DS), US and VPN communications. The bit error rates (BERs) of DS, US and VPN for OFDM signals are below the forward-error-correction (FEC) limit of 3 . 8 × 10-3 when the received optical powers are about -16.8 dBm, -14.5 dBm and -15.7 dBm, respectively.

  14. Direct Spectroscopy in Hollow Optical with Fiber-Based Optical Frequency Combs

    Science.gov (United States)

    2015-07-09

    Perrella, P. S. Light, F. Benabid, and A. N. Luiten, "Towards a compact optical fibre clock," in Precision Electromagnetic Measurements (CPEM), 2010...AFRL-OSR-VA-TR-2015-0184 DIRECT SPECTROSCOPY IN HOLLOW OPTICAL WITH FIBER-BASED OPTICAL FREQUENCY COMBS Kristan Corwin KANSAS STATE UNIVERSITY Final...Performance 3.  DATES COVERED (From - To)      01-06-2011 to 31-05-2015 4.  TITLE AND SUBTITLE DIRECT SPECTROSCOPY IN HOLLOW OPTICAL WITH FIBER-BASED

  15. Semi-transparent solar cells

    Science.gov (United States)

    Sun, J.; Jasieniak, J. J.

    2017-03-01

    Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies.

  16. All-optical microwave signal processing based on optical phase modulation

    Science.gov (United States)

    Zeng, Fei

    This thesis presents a theoretical and experimental study of optical phase modulation and its applications in all-optical microwave signal processing, which include all-optical microwave filtering, all-optical microwave mixing, optical code-division multiple-access (CDMA) coding, and ultrawideband (UWB) signal generation. All-optical microwave signal processing can be considered as the use of opto-electronic devices and systems to process microwave signals in the optical domain, which provides several significant advantages such as low loss, low dispersion, light weight, high time bandwidth products, and immunity to electromagnetic interference. In conventional approaches, the intensity of an optical carrier is modulated by a microwave signal based on direct modulation or external modulation. The intensity-modulated optical signal is then fed to a photonic circuit or system to achieve specific signal processing functionalities. The microwave signal being processed is usually obtained based on direct detection, i.e., an opto-electronic conversion by use of a photodiode. In this thesis, the research efforts are focused on the optical phase modulation and its applications in all-optical microwave signal processing. To avoid using coherent detection which is complicated and costly, simple and effective phase modulation to intensity modulation (PM-IM) conversion schemes are pursued. Based on a theoretical study of optical phase modulation, two approaches to achieving PM-IM conversions are proposed. In the first approach, the use of chromatic dispersion induced by a dispersive device to alter the phase relationships among the sidebands and the optical carrier of a phase-modulated optical signal to realize PM-IM conversion is investigated. In the second approach, instead of using a dispersive device, the PM-IM conversion is realized based on optical frequency discrimination implemented using an optical filter. We show that the proposed PM-IM conversion schemes can be

  17. An Optical Biosensing Strategy Based on Selective Light Absorption and Wavelength Filtering from Chromogenic Reaction

    Directory of Open Access Journals (Sweden)

    Hyeong Jin Chun

    2018-03-01

    Full Text Available To overcome the time and space constraints in disease diagnosis via the biosensing approach, we developed a new signal-transducing strategy that can be applied to colorimetric optical biosensors. Our study is focused on implementation of a signal transduction technology that can directly translate the color intensity signals—that require complicated optical equipment for the analysis—into signals that can be easily counted with the naked eye. Based on the selective light absorption and wavelength-filtering principles, our new optical signaling transducer was built from a common computer monitor and a smartphone. In this signal transducer, the liquid crystal display (LCD panel of the computer monitor served as a light source and a signal guide generator. In addition, the smartphone was used as an optical receiver and signal display. As a biorecognition layer, a transparent and soft material-based biosensing channel was employed generating blue output via a target-specific bienzymatic chromogenic reaction. Using graphics editor software, we displayed the optical signal guide patterns containing multiple polygons (a triangle, circle, pentagon, heptagon, and 3/4 circle, each associated with a specified color ratio on the LCD monitor panel. During observation of signal guide patterns displayed on the LCD monitor panel using a smartphone camera via the target analyte-loaded biosensing channel as a color-filtering layer, the number of observed polygons changed according to the concentration of the target analyte via the spectral correlation between absorbance changes in a solution of the biosensing channel and color emission properties of each type of polygon. By simple counting of the changes in the number of polygons registered by the smartphone camera, we could efficiently measure the concentration of a target analyte in a sample without complicated and expensive optical instruments. In a demonstration test on glucose as a model analyte, we

  18. Optical driven electromechanical transistor based on tunneling effect.

    Science.gov (United States)

    Jin, Leisheng; Li, Lijie

    2015-04-15

    A new electromechanical transistor based on an optical driven vibrational ring structure has been postulated. In the device, optical power excites the ring structure to vibrate, which acts as the shuttle transporting electrons from one electrode to the other forming the transistor. The electrical current of the transistor is adjusted by the optical power. Coupled opto-electro-mechanical simulation has been performed. It is shown from the dynamic analysis that the stable working range of the transistor is much wider than that of the optical wave inside the cavity, i.e., the optical resonance enters nonperiodic states while the mechanical vibration of the ring is still periodic.

  19. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS-. P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation coefficient (Kd) and an optical ...

  20. Vertical diffuse attenuation coefficient (Kd) based optical ...

    Indian Academy of Sciences (India)

    The optical classification of the different water types provides vital input for studies related to primary productivity, water clarity and determination of euphotic depth. Image data of the IRS- P3 MOS-B, for Path 90 of 27th February, 1998 was used for deriving vertical diffuse attenuation Coeffcient () and an optical ...

  1. Towards risk-based drought management in the Netherlands: making water supply levels transparent to water users

    Science.gov (United States)

    Maat Judith, Ter; Marjolein, Mens; Vuren Saskia, Van; der Vat Marnix, Van

    2016-04-01

    To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, assessed the impact of climate change and socio-economic development, and explored strategies to deal with these impacts. The Programme initiated a joint approach to water supply management with stakeholders and developed a national adaptation plan that is able to adapt to future uncertain conditions. The adaptation plan consists of a set of preferred policy pathways - sequences of possible actions and measures through time - to achieve targets while responding in a flexible manner to uncertain developments over time, allowing room to respond to new opportunities and insights. With regard to fresh water allocation, the Delta Programme stated that supplying water of sufficient quality is a shared responsibility that requires cohesive efforts among users in the main and regional water system. The national and local authorities and water users involved agreed that the water availability and, where relevant, the water quality should be as transparent and predictable as possible under normal, dry and extremely dry conditions. They therefore introduced the concept of "water supply service levels", which should describe water availability and quality that can be delivered with a certain return period, for all regions and all relevant water users in the Netherlands. The service levels form an addition to the present policy and should be decided on by 2021. At present water allocation during periods of (expected) water shortage occurs according to a prearranged ranking system (a water hierarchy scheme based on a list of priorities), if water availability drops below a critical low level. The aim is to have supply levels available that are based on the probability of occurrence and economic impact of water shortage, and that are transparent for all water users in the regional water systems and the main water system. As part of the European project

  2. Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd3Al5O12)

    Science.gov (United States)

    Li, Ji-Guang; Sakka, Yoshio

    2015-02-01

    This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd3+ to the activator. Ce3+ doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out.

  3. Noninvasive blood pressure measurement scheme based on optical fiber sensor

    Science.gov (United States)

    Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

    2016-10-01

    Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

  4. Inverse Mapping Structures onto Transparency

    Science.gov (United States)

    Ferris, Kim F.; Sun, Xin; Whitney, Paul A.

    2008-03-01

    Composite materials have continued to make a number of improvements in physical properties (mechanical moduli), but lag behind in optical responses such as transparency. The hybrid nature of the composite material, particle and host matrix, divides light scattering issues into particle size regimes, where the particle size d >> lambda and approximations such as anomalous dispersion have proven useful, and dceramic-polymer composite as a case example, we have used black box optimization methods to examine the practical bounds for each regime and to assess design rules. These guidelines suggest limitations for particle morphologies and the optical properties of the component materials.

  5. Study of research-based teaching mode in the course of Geometric Optics and Optical Instruments

    Science.gov (United States)

    Wang, Zefeng; Geng, Meihua; Cheng, Xiangai; Jiang, Zongfu

    2017-08-01

    Modern teaching opinions require research-based teaching mode in research universities. It is an advanced teaching mode enabling students to explore science and technology autonomously. It has a lot of advantages comparing with the conventional knowledge-oriented teaching mode. In this paper, we show some understanding of research-based teaching mode. And based on the course features of Geometric optics and optical instruments and characteristics of students, we explore the research-based teaching mode in the part of Practical Optical Systems.

  6. Optical Engines as Representative Tools in the Development of New Combustion Engine Concepts Moteurs transparents comme outils représentatifs dans le développement de nouveaux concepts des moteurs à combustion interne

    Directory of Open Access Journals (Sweden)

    Kashdan J.

    2011-11-01

    (EGR. A comparison has been made between simulated EGR (using pure nitrogen with real EGR under Diesel LTC conditions. Finally, “pure”, single component fuels are often employed in optical Diesel engines due to laser diagnostic constraints. However, these fuels generally differ from standard Diesel fuel in terms of cetane number and fuel volatility which can significantly influence the combustion and emissions characteristics in optical engines. These aspects have also been investigated within the present study. An improved understanding of the differences between optical and all-metal engines has allowed us to develop appropriate strategies to compensate for these differences on the optical engine. It is shown here that combustion phasing (and engine-out emissions matching between optical and all-metal engines can be achieved even for advanced LTC Diesel combustion strategies. The ability to ensure fully representative combustion and emissions behaviour of optical engines ultimately increases the value of optical engine data, highlighting the importance of using such engines as research tools for the further development of innovative, low emission combustion concepts. Les moteurs monocylindres transparents sont employés comme outils de recherche et de développement des moteurs à combustion interne. Ils permettent l’utilisation de techniques de diagnostics non-intrusifs (qualitatifs et quantitatifs pour étudier des phénomènes comme l’aérodynamique interne, la préparation du mélange, la combustion et la formation de polluants. Ces données expérimentales sont importantes pour la validation des modèles numériques et permettent également d’obtenir une compréhension détaillée des phénomènes physiques se déroulant dans la chambre. Les données recueillies aident au développement des nouvelles stratégies de combustion telles que la combustion homogène (HCCI et la combustion Diesel à basse température (LTC. Dans ce contexte, il est important

  7. Optical microscopic imaging based on VRML language

    Science.gov (United States)

    Zhang, Xuedian; Zhang, Zhenyi; Sun, Jun

    2009-11-01

    As so-called VRML (Virtual Reality Modeling Language), is a kind of language used to establish a model of the real world or a colorful world made by people. As in international standard, VRML is the main kind of program language based on the "www" net building, which is defined by ISO, the kind of MIME is x-world or x-VRML. The most important is that it has no relationship with the operating system. Otherwise, because of the birth of VRML 2.0, its ability of describing the dynamic condition gets better, and the interaction of the internet evolved too. The use of VRML will bring a revolutionary change of confocal microscope. For example, we could send different kinds of swatch in virtual 3D style to the net. On the other hand, scientists in different countries could use the same microscope in the same time to watch the same samples by the internet. The mode of sending original data in the model of text has many advantages, such as: the faster transporting, the fewer data, the more convenient updating and fewer errors. In the following words we shall discuss the basic elements of using VRML in the field of Optical Microscopic imaging.

  8. Up to 20 Gbit/s bit-rate transparent integrated interferometric wavelength converter

    DEFF Research Database (Denmark)

    Jørgensen, Carsten; Danielsen, Søren Lykke; Hansen, Peter Bukhave

    1996-01-01

    We present a compact and optimised multiquantum-well based, integrated all-active Michelson interferometer for 26 Gbit/s optical wavelength conversion. Bit-rate transparent operation is demonstrated with a conversion penalty well below 0.5 dB at bit-rates ranging from 622 Mbit/s to 20 Gbit/s....

  9. Glass-based integrated optical splitters: engineering oriented research

    Science.gov (United States)

    Hao, Yinlei; Zheng, Weiwei; Yang, Jianyi; Jiang, Xiaoqing; Wang, Minghua

    2010-10-01

    Optical splitter is one of most typical device heavily demanded in implementation of Fiber To The Home (FTTH) system. Due to its compatibility with optical fibers, low propagation loss, flexibility, and most distinguishingly, potentially costeffectiveness, glass-based integrated optical splitters made by ion-exchange technology promise to be very attractive in application of optical communication networks. Aiming at integrated optical splitters applied in optical communication network, glass ion-exchange waveguide process is developed, which includes two steps: thermal salts ion-exchange and field-assisted ion-diffusion. By this process, high performance optical splitters are fabricated in specially melted glass substrate. Main performance parameters of these splitters, including maximum insertion loss (IL), polarization dependence loss (PDL), and IL uniformity are all in accordance with corresponding specifications in generic requirements for optic branching components (GR-1209-CORE). In this paper, glass based integrated optical splitters manufacturing is demonstrated, after which, engineering-oriented research work results on glass-based optical splitter are presented.

  10. Transparent graphene microstrip filters for wireless communications

    Science.gov (United States)

    Wang, Jinchen; Guan, Yifei; Yu, Hua; Li, Na; Wang, Shuopei; Shen, Cheng; Dai, Zhijiang; Gan, Decheng; Yang, Rong; He, Songbai; Zhang, Guangyu

    2017-08-01

    A microstrip is an indispensable component for wireless communication circuits. With the development of 5G technology, optically transparent microstrip filters urgently need to be developed. In this work, we have theoretically and experimentally demonstrated the immense potential of graphene microstrips for transparent wireless communication circuits in the 5G era. Both wideband and dual-band transparent graphene microstrip filters have shown more than 80% optical transmissivity in the region from 250 nm to 2000 nm with good frequency responses. S and C band microwave signals can transmit along the graphene microstrip lines effectively while coupling excitations produce relatively large insertion losses. Our results show that transparent microstrips designed with high-quality graphene will largely scale down the size of the wireless devices and thus play an irreplaceable role in the 5G era.

  11. Peering into Transparency

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger; Cheney, George

    2015-01-01

    The current emphasis on organizational transparency signifies a growing demand for insight, clarity, accountability, and participation. Holding the promise of improved access to valid and trustworthy knowledge about organizations, the transparency pursuit has great potential for enhanced organiza...

  12. Mining and biodiversity offsets: a transparent and science-based approach to measure "no-net-loss".

    Science.gov (United States)

    Virah-Sawmy, Malika; Ebeling, Johannes; Taplin, Roslyn

    2014-10-01

    Mining and associated infrastructure developments can present themselves as economic opportunities that are difficult to forego for developing and industrialised countries alike. Almost inevitably, however, they lead to biodiversity loss. This trade-off can be greatest in economically poor but highly biodiverse regions. Biodiversity offsets have, therefore, increasingly been promoted as a mechanism to help achieve both the aims of development and biodiversity conservation. Accordingly, this mechanism is emerging as a key tool for multinational mining companies to demonstrate good environmental stewardship. Relying on offsets to achieve "no-net-loss" of biodiversity, however, requires certainty in their ecological integrity where they are used to sanction habitat destruction. Here, we discuss real-world practices in biodiversity offsetting by assessing how well some leading initiatives internationally integrate critical aspects of biodiversity attributes, net loss accounting and project management. With the aim of improving, rather than merely critiquing the approach, we analyse different aspects of biodiversity offsetting. Further, we analyse the potential pitfalls of developing counterfactual scenarios of biodiversity loss or gains in a project's absence. In this, we draw on insights from experience with carbon offsetting. This informs our discussion of realistic projections of project effectiveness and permanence of benefits to ensure no net losses, and the risk of displacing, rather than avoiding biodiversity losses ("leakage"). We show that the most prominent existing biodiversity offset initiatives employ broad and somewhat arbitrary parameters to measure habitat value and do not sufficiently consider real-world challenges in compensating losses in an effective and lasting manner. We propose a more transparent and science-based approach, supported with a new formula, to help design biodiversity offsets to realise their potential in enabling more responsible

  13. CCD-based optical CT scanning of highly attenuating phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nowais, Shamsa [Department of Physics, University of Surrey, Guildford (United Kingdom); Doran, Simon J [CRUK Clinical MR Research Group, Institute of Cancer Research, Sutton (United Kingdom)], E-mail: Simon.Doran@icr.ac.uk

    2009-05-01

    The introduction of optical computed tomography (optical-CT) offers economic and easy to use 3-D optical readout for gel dosimeters. However, previous authors have noted some challenges regarding the accuracy of such imaging techniques at high values of optical density. In this paper, we take a closer look at the 'cupping' artefact evident in both light-scattering polymer systems and highly light absorbing phantoms using our CCD-based optical scanner. In addition, a technique is implemented whereby the maximum measurable optical absorbance is extended to correct for any errors that may have occurred in the estimated value of the dark current or ambient light reaching the detector. The results indicate that for absorbance values up to 2.0, the optical scanner results have good accuracy, whereas this is not the case at high absorbance values for reasons yet to be explained.

  14. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  15. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    International Nuclear Information System (INIS)

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 x 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V x ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V x , the polarization of an incoming, linearly polarized, laser beam is rotated by 90 degree. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 x 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches

  16. Peptide Optical waveguides.

    Science.gov (United States)

    Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil

    2017-02-01

    Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  17. Photonic processing and realization of an all-optical digital comparator based on semiconductor optical amplifiers

    Science.gov (United States)

    Singh, Simranjit; Kaur, Ramandeep; Kaler, Rajinder Singh

    2015-01-01

    A module of an all-optical 2-bit comparator is analyzed and implemented using semiconductor optical amplifiers (SOAs). By employing SOA-based cross phase modulation, the optical XNOR logic is used to get an A=B output signal, where as AB¯ and A¯B> logics operations are used to realize A>B and Aoperations results along with the wide open eye diagrams are obtained. It is suggested that the proposed system would be promising in all-optical high speed networks and computing systems.

  18. Synthesis of Ultrathin Copper Nanowires Using Tris(trimethylsilyl)silane for High-Performance and Low-Haze Transparent Conductors.

    Science.gov (United States)

    Cui, Fan; Yu, Yi; Dou, Letian; Sun, Jianwei; Yang, Qin; Schildknecht, Christian; Schierle-Arndt, Kerstin; Yang, Peidong

    2015-11-11

    Colloidal metal nanowire based transparent conductors are excellent candidates to replace indium-tin-oxide (ITO) owing to their outstanding balance between transparency and conductivity, flexibility, and solution-processability. Copper stands out as a promising material candidate due to its high intrinsic conductivity and earth abundance. Here, we report a new synthetic approach, using tris(trimethylsilyl)silane as a mild reducing reagent, for synthesizing high-quality, ultrathin, and monodispersed copper nanowires, with an average diameter of 17.5 nm and a mean length of 17 μm. A study of the growth mechanism using high-resolution transmission electron microscopy reveals that the copper nanowires adopt a five-fold twinned structure and evolve from decahedral nanoseeds. Fabricated transparent conducting films exhibit excellent transparency and conductivity. An additional advantage of our nanowire transparent conductors is highlighted through reduced optical haze factors (forward light scattering) due to the small nanowire diameter.

  19. Digitally tunable optical filter based on DWDM thin film filters and semiconductor optical amplifiers.

    Science.gov (United States)

    Li, Xinwan; Chen, Jianping; Wu, Guiling; Ye, Ailun

    2005-02-21

    We demonstrate a novel digitally tunable optical filter, which is based on dense wavelength division multiplexed (DWDM) thin film filters and semiconductor optical amplifiers (SOA). It has the advantages of fast tuning speed, large tuning range, good temperature stability, simple control mechanism. It is also scalable without bringing additional insertion loss. The passband wavelengths are in consistency with those suggested by ITUT.

  20. Optical phantoms of varying geometry based on thin building blocks with controlled optical properties

    NARCIS (Netherlands)

    de Bruin, Daniel M.; Bremmer, Rolf H.; Kodach, Vitali M.; de Kinkelder, Roy; van Marle, Jan; van Leeuwen, Ton; Faber, Dirk J.

    2010-01-01

    Current innovations in optical imaging, measurement techniques, and data analysis algorithms express the need for reliable testing and comparison methods. We present the design and characterization of silicone elastomer-based optical phantoms. Absorption is included by adding a green dye and

  1. Optical Generation of Fuzzy-Based Rules

    Science.gov (United States)

    Gur, Eran; Mendlovic, David; Zalevsky, Zeev

    2002-08-01

    In the last third of the 20th century, fuzzy logic has risen from a mathematical concept to an applicable approach in soft computing. Today, fuzzy logic is used in control systems for various applications, such as washing machines, train-brake systems, automobile automatic gear, and so forth. The approach of optical implementation of fuzzy inferencing was given by the authors in previous papers, giving an extra emphasis to applications with two dominant inputs. In this paper the authors introduce a real-time optical rule generator for the dual-input fuzzy-inference engine. The paper briefly goes over the dual-input optical implementation of fuzzy-logic inferencing. Then, the concept of constructing a set of rules from given data is discussed. Next, the authors show ways to implement this procedure optically. The discussion is accompanied by an example that illustrates the transformation from raw data into fuzzy set rules.

  2. The role of air annealing on the optical and scintillation properties of Mg co-doped Pr:LuAG transparent ceramics

    Czech Academy of Sciences Publication Activity Database

    Hu, Z.; Cao, M.; Chen, H.; Shi, Y.; Kou, H.; Xie, T.; Wu, L.; Pan, Y.; Feng, X.; Vedda, A.; Beitlerová, Alena; Nikl, Martin; Li, J.

    2017-01-01

    Roč. 72, Oct (2017), s. 201-207 ISSN 0925-3467 R&D Projects: GA ČR GA16-15569S Institutional support: RVO:68378271 Keywords : Mg co-doped Pr:LuAG * transparent ceramics * annealing effect * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.238, year: 2016

  3. Development of a highly transparent fluorescent optical sensor for transverse positioning of multiple elements with respect to a reference laser beam [for ATLAS experiment

    CERN Document Server

    Barrière, J C; Bourdinaud, M; Cloué, O; Molinie, F; Schune, P

    1999-01-01

    A new type of highly transparent (95%) two dimensional position sensor has been developed which allows the accurate positioning (below 10 mu m r.m.s.) of successive elements to which each sensor is attached, transversely to a laser beam used as a reference straight line. The present useful area of the sensor is about 15*15 mm/sup 2/, and can be further increased. (3 refs).

  4. Transparent conducting oxides and production thereof

    Science.gov (United States)

    Gessert, Timothy A; Yoshida, Yuki; Coutts, Timothy J

    2014-05-27

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target (110) doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber (100). The method may also comprise depositing a metal oxide on the target (110) to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  5. Management Concerns for Optical Based Filing Systems

    Science.gov (United States)

    1990-03-01

    Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN INFORMATION SYSTEMS from the NAVAL POSTGRADUATE SCHOOL March... social security number (SSN) of an individual may be inadequate if there are many records for an individual. While descriptors from a particular record...displayed. - Source The Hanbook ofOptical Memor Syste s p. 6.0-Z Optical Disk Intitute, 1989 Figure 4. Retrieval Time Factors 42 V. SERVICE RECORD

  6. Innovative transparent armour concepts

    NARCIS (Netherlands)

    Carton, E.P.; Broos, J.P.F.

    2011-01-01

    Ever since WWII transparent armour consists of a multi-layer of glass panels bonded by thin polymer bond-films using an autoclave process. TNO has worked on the development of innovative transparent armour concepts that are lighter and a have better multi-hit capacity. Two new transparent armour

  7. The influence of corporate social responsibility, ability, reputation, and transparency on hotel customer loyalty in the U.S.: a gender-based approach

    OpenAIRE

    Kim, Sung-Bum; Kim, Dae-Young

    2016-01-01

    This research explored a conceptual framework incorporating interrelationships among corporate social responsibility (CSR), corporate ability (CA), corporate reputation (CR), and CSR-related transparency on customer loyalty within the hotel context. In this study, we also analyzed consumers? propensity to support CSR initiatives through the socio-demographic indicator of gender. We used independent sample t test and multiple regression analysis to test hypotheses based on 487 responses from A...

  8. Fully transparent conformal organic thin-film transistor array and its application as LED front driving.

    Science.gov (United States)

    Cui, Nan; Ren, Hang; Tang, Qingxin; Zhao, Xiaoli; Tong, Yanhong; Hu, Wenping; Liu, Yichun

    2018-02-22

    A fully transparent conformal organic thin-film field-effect transistor array is demonstrated based on a photolithography-compatible ultrathin metallic grid gate electrode and a solution-processed C 8 -BTBT film. The resulting organic field-effect transistor array exhibits a high optical transparency of >80% over the visible spectrum, mobility up to 2 cm 2 V -1 s -1 , on/off ratio of 10 5 -10 6 , switching current of >0.1 mA, and excellent light stability. The transparent conformal transistor array is demonstrated to adhere well to flat and curved LEDs as front driving. These results present promising applications of the solution-processed wide-bandgap organic semiconductor thin films in future large-scale transparent conformal active-matrix displays.

  9. Transparency as an element of public confidence

    International Nuclear Information System (INIS)

    Kim, H.K.

    2007-01-01

    In the modern society, there is increasing demands for greater transparency. It has been discussed with respect to corruption or ethics issues in social science. The need for greater openness and transparency in nuclear regulation is widely recognised as public expectations on regulator grow. It is also related to the digital and information technology that enables disclosures of every activity and information of individual and organisation, characterised by numerous 'small brothers'. Transparency has become a key word in this ubiquitous era. Transparency in regulatory activities needs to be understood in following contexts. First, transparency is one of elements to build public confidence in regulator and eventually to achieve regulatory goal of providing the public with satisfaction at nuclear safety. Transparent bases of competence, independence, ethics and integrity of working process of regulatory body would enhance public confidence. Second, activities transmitting information on nuclear safety and preparedness to be accessed are different types of transparency. Communication is an active method of transparency. With increasing use of web-sites, 'digital transparency' is also discussed as passive one. Transparency in regulatory process may be more important than that of contents. Simply providing more information is of little value and specific information may need to be protected for security reason. Third, transparency should be discussed in international, national and organizational perspectives. It has been demanded through international instruments. for each country, transparency is demanded by residents, public, NGOs, media and other stakeholders. Employees also demand more transparency in operating and regulatory organisations. Whistle-blower may appear unless they are satisfied. Fourth, pursuing transparency may cause undue social cost or adverse effects. Over-transparency may decrease public confidence and the process for transparency may also hinder

  10. Transparent Electrodes with Nanotubes and Graphene for Printed Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Marcin Słoma

    2014-01-01

    Full Text Available We report here on printed electroluminescent structures containing transparent electrodes made of carbon nanotubes and graphene nanoplatelets. Screen-printing and spray-coating techniques were employed. Electrodes and structures were examined towards optical parameters using spectrophotometer and irradiation meter. Electromechanical properties of transparent electrodes are exterminated with cyclical bending test. Accelerated aging process was conducted according to EN 62137 standard for reliability tests of electronics. We observed significant negative influence of mechanical bending on sheet resistivity of ITO, while resistivity of nanotube and graphene based electrodes remained stable. Aging process has also negative influence on ITO based structures resulting in delamination of printed layers, while those based on carbon nanomaterials remained intact. We observe negligible changes in irradiation for structures with carbon nanotube electrodes after accelerated aging process. Such materials demonstrate a high application potential in general purpose electroluminescent devices.

  11. Traffic allocation strategies in WSS-based dynamic optical networks

    OpenAIRE

    Shakeri, Ali; Garrich, Miquel; Bravalheri, Anderson; Careglio, Davide; Solé Pareta, Josep; Fumagalli, Andrea

    2017-01-01

    Elastic optical networking (EON) is a viable solution to meet future dynamic capacity requirements of Internet service provider and inter-datacenter networks. At the core of EON, wavelength selective switches (WSSs) are applied to individually route optical circuits, while assigning an arbitrary bandwidth to each circuit. Critically, the WSS control scheme and configuration time may delay the creation time of each circuit in the network. In this paper, we first detail the WSS-based optical da...

  12. The influence of corporate social responsibility, ability, reputation, and transparency on hotel customer loyalty in the U.S.: a gender-based approach.

    Science.gov (United States)

    Kim, Sung-Bum; Kim, Dae-Young

    2016-01-01

    This research explored a conceptual framework incorporating interrelationships among corporate social responsibility (CSR), corporate ability (CA), corporate reputation (CR), and CSR-related transparency on customer loyalty within the hotel context. In this study, we also analyzed consumers' propensity to support CSR initiatives through the socio-demographic indicator of gender. We used independent sample t test and multiple regression analysis to test hypotheses based on 487 responses from American participants. Four antecedents (i.e., CSR, CA, CR, and transparency) exhibited favorable effects on customer loyalty. Among these four factors, the positively perceived CSR initiatives had a greater impact on customer loyalty. In addition, according to our findings, female participants were more likely to have a positive perception of the four antecedents than males.

  13. The art of transparency.

    Science.gov (United States)

    Sayim, Bilge; Cavanagh, Patrick

    2011-01-01

    Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles.

  14. Large Optical Telescope Based on High Efficiency Thin Film Planar Diffractive Optics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In future ground-based receivers for deep-space optical communications with spacecraft, aperture diameters of the order of 10 meters are required even with the most...

  15. Plasticized Polymer Interlayer for Low-Temperature Fabrication of a High-Quality Silver Nanowire-Based Flexible Transparent and Conductive Film

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Wonhee; Kang, Hong Suk; Choi, Jaeho; Lee, Hongkyung; Kim, Hee-Tak

    2017-04-18

    Silver nanowires (AgNWs) are one of the most promising materials to replace commercially available indium tin oxide in flexible transparent conductive films (TCFs); however, there are still numerous problems originating from poor AgNW junction formation and improper AgNW embedment into transparent substrates. To mitigate these problems, high-temperature processes have been adopted; however, unwanted substrate deformation prevents the use of these processes for the formation of flexible TCFs. In this work, we present a novel poly(methyl methacrylate) interlayer plasticized by dibutyl phthalate for low-temperature fabrication of AgNW-based TCFs, which does not cause any substrate deformation. By exploiting the viscoelastic properties of the plasticized interlayer near the lowered glass-transition temperature, a monolithic junction of AgNWs on the interlayer and embedment of the interconnected AgNWs into the interlayer are achieved in a single-step pressing. The resulting AgNW-TCFs are highly transparent (~92% at a wavelength of 550 nm), highly conductive (<90 Ω/sq), and environmentally and mechanically robust. Therefore, the plasticized interlayer provides a simple and effective route to fabricate high-quality AgNW-based TCFs.

  16. Electromagnetically induced transparency in an open multilevel system

    International Nuclear Information System (INIS)

    Li Tian; Lu Meiju; Weinstein, Jonathan D.

    2011-01-01

    Electromagnetically induced transparency in a multilevel system is investigated in 173 Yb. The level structure investigated is ''open'' in that the light that gives rise to the transparency also resonantly couples the atoms to excited states which do not exhibit electromagnetically induced transparency. The resulting reduction of transparency is investigated experimentally and theoretically. It is found that, while the transparency is poor in certain regimes, it can be made to perform arbitrarily well in the limit of a large intensity imbalance between the optical fields.

  17. Elongation-based fiber optic tunable filter

    Science.gov (United States)

    Pérez-Sánchez, G. G.; Mejia-Islas, J. A.; Andrade-González, E. A.; Pérez-Torres, J. R.

    2017-09-01

    This paper focuses on introducing the results of a model using a control system for an optical filter that can be tuned, using a solution that employs both, an elongation control system and a fiber Bragg grating. At the first stage, the optical characterization of the filter was made, then the stepper motors were chosen for the desired wavelength selection with a couple of pulleys which produce the grating elongation and, as a consequence, the wavelength shifting. The pulleys diameters were calculated to produce 0.8 nm shift for each filtering wavelength using a control program.

  18. Broadband illusion optical devices based on conformal mappings

    Science.gov (United States)

    Xiong, Zhan; Xu, Lin; Xu, Ya-Dong; Chen, Huan-Yang

    2017-10-01

    In this paper, we propose a simple method of illusion optics based on conformal mappings. By carefully developing designs with specific conformal mappings, one can make an object look like another with a significantly different shape. In addition, the illusion optical devices can work in a broadband of frequencies.

  19. Photodiode Based Detection for Multiple Trap Optical Tweezers

    DEFF Research Database (Denmark)

    Ott, Dino

    This thesis is concerned with the position tracking of microscopic, optically trapped particles and the quantification of the forces acting on them. A new detection method for simultaneous, three-dimensional tracking of multiple particles is presented, its performance is evaluated, and its...... usefulness is illustrated in specific application examples. Optical traps enable contact-less, all-optical manipulation of microscopic objects. Over the last decades, this laser-based micro-manipulation tool has facilitated numerous exciting discoveries within biology and physics, and it is today regarded...... as one of the workhorses of biophysical research. There exists a variety of implementations of optical traps, from simple single traps to complex multiple traps with engineered three-dimensional light fields. In comparison to single beam optical traps, multiple beam optical traps offer more freedom...

  20. Transparent Memory For Harsh Electronics

    KAUST Repository

    Ho, C. H.

    2017-03-14

    As a new class of non-volatile memory, resistive random access memory (RRAM) offers not only superior electronic characteristics, but also advanced functionalities, such as transparency and radiation hardness. However, the environmental tolerance of RRAM is material-dependent, and therefore the materials used must be chosen carefully in order to avoid instabilities and performance degradation caused by the detrimental effects arising from environmental gases and ionizing radiation. In this work, we demonstrate that AlN-based RRAM displays excellent performance and environmental stability, with no significant degradation to the resistance ratio over a 100-cycle endurance test. Moreover, transparent RRAM (TRRAM) based on AlN also performs reliably under four different harsh environmental conditions and 2 MeV proton irradiation fluences, ranging from 1011 to 1015 cm-2. These findings not only provide a guideline for TRRAM design, but also demonstrate the promising applicability of AlN TRRAM for future transparent harsh electronics.

  1. Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles.

    Science.gov (United States)

    Bucaro, Michael A; Kolodner, Paul R; Taylor, J Ashley; Sidorenko, Alex; Aizenberg, Joanna; Krupenkin, Tom N

    2009-04-09

    In this paper, we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality-for example, a dynamic 3D projector, i.e., a light source which can scan an image onto a moving, nonplanar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

  2. Through a glass darkly - the meaning of transparency

    International Nuclear Information System (INIS)

    Loy, J.

    2007-01-01

    The paper first discusses the word 'transparency'. It is a metaphor drawn from optics; it is a term used in social and political science; the international civil society organisation. 'Transparency International' sees it as the paradigm to fight corruption in the world. From this discussion, the paper offers a working definition applicable to a nuclear regulatory organisation. The paper describes a difference between having transparent process, which might be called passive transparency; and transparent engagement with stakeholders -- active transparency. It discusses some of the issues and problems that arise for a nuclear regulatory organisation seeking to operate transparently. Much of the difficulty with true transparency is that it reveals the 'untidiness' of life. 'We see now as through a glass darkly'. What is the general view of society and the cultural attitudes towards Government agencies revealing that they are not perfect'? Can you have a transparent nuclear regulator of a secretive industry and with other stakeholders having political agendas? How can a technical 'judgment call' ever be fully transparent? Can an active culture of transparency sometimes result in a mere public relations campaign? Can transparency in a nuclear regulatory create expectations amongst stakeholders that will prove impossible to meet? These questions are discussed with some real-life examples. The paper concludes with some suggested 'fundamentals' for transparency in nuclear regulatory organisations. (author)

  3. Transparent antennas for solar cell integration

    Science.gov (United States)

    Yasin, Tursunjan

    Transparent patch antennas are microstrip patch antennas that have a certain level of optical transparency. Highly transparent patch antennas are potentially suitable for integration with solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas employed on small satellites compete with solar cells for surface area. However, a transparent patch antenna can be placed directly on top of solar cells and resolve the issue of competing for limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells' point of view. On the other hand, the antenna should possess at least acceptable radiation properties at the same time. This dissertation focuses on some of the most important concerns from the perspective of small satellite applications. For example, an optimization method to simultaneously improve both optical transparency and radiation efficiency of the antenna is studied. Active integrated antenna design method is extended to meshed patch applications in an attempt to improve the overall power efficiency of the front end communication subsystem. As is well known, circular polarization is immune from Faraday rotation effect in the ionosphere and thus can avoid a 3-dB loss in geo-satellite communication. Therefore, this research also aims to present design methods for circularly polarized meshed patch antennas. Moreover, a meshed patch antenna capable of supporting a high communication data rate is investigated. Lastly, other types of transparent patch antennas are also analyzed and compared to meshed patches. In summary, many properties of transparent patch antennas are examined in order to meet different design requirements.

  4. Flame-retardant polyvinyl alcohol membrane with high transparency based on a reactive phosphorus-containing compound

    Science.gov (United States)

    Peng, Sha; Zhou, Ming; Liu, Feiyan; Zhang, Chang; Liu, Xueqing; Liu, Jiyan; Zou, Liyong; Chen, Jia

    2017-08-01

    Flame-retardant polyvinyl alcohol (PVA) membranes with high transparency and flexibility were prepared by mixing an aqueous solution of a phosphorus-containing acrylic acid (AOPA) with PVA. The reaction between AOPA and PVA, the transparency, the crystallinity and the flexibility of the membrane were investigated with Fourier transform infrared spectrometry (FTIR), UV-vis light transmittance, X-ray diffraction and tensile tests, respectively. The limited oxygen index (LOI) and vertical flame (UL 94 VTM), microscale combustion calorimetry, thermogravimetric analysis (TGA) and TGA-FTIR were employed to evaluate the flame retardancy as well as to reveal the corresponding mechanisms. Results showed that PVA containing 30 wt% of AOPA can reach the UL 94 VTM V0 rating with an LOI of 27.3% and retain 95% of the original transparency of pure PVA. Adding AOPA reduces crystallinity of PVA, while the flexibility is increased. AOPA depresses the thermal degradation of PVA and promotes char formation during combustion. The proposed decomposition mechanism indicates that AOPA acts mainly in the condensed phase.

  5. Organizational Transparency in the Internet Industry

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel

    Reporting from an empirical investigation at Google and Facebook, this paper conceptualizes the stabilization of transparency as a form and norm conduct connecting and shaping technical, financial, cultural and political processes in the Internet industry. Rather than approach transparency...... on transparency, we have very few in-depth empirical investigations of its organizational and regulatory ramifications, particularly in the Internet industry. Based on interviews and extensive empirical material about Google's and Facebook's engagement with transparency idea(l)s, the paper shows how...... as a panacea to concerns about privacy, organizational conduct and accountability, this paper explores the boundary work that goes into doing and promising transparency Using insights from the literature on transparency, ´sociologies of translations' and process approaches to organization, this paper captures...

  6. Organizational Transparency in the Internet Industry

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel

    Reporting from an empirical investigation at Google and Facebook, this paper conceptualizes the stabilization of transparency as a form and norm conduct connecting and shaping technical, financial, cultural and political processes in the Internet industry. Rather than approach transparency...... as a panacea to concerns about privacy, organizational conduct and accountability, this paper explores the boundary work that goes into doing and promising transparency Using insights from the literature on transparency, ´sociologies of translations' and process approaches to organization, this paper captures...... on transparency, we have very few in-depth empirical investigations of its organizational and regulatory ramifications, particularly in the Internet industry. Based on interviews and extensive empirical material about Google's and Facebook's engagement with transparency idea(l)s, the paper shows how...

  7. Proposal for electro-optic multiplier based on dual transverse electro-optic Kerr effect.

    Science.gov (United States)

    Li, Changsheng

    2008-10-20

    A novel electro-optic multiplier is proposed, which can perform voltage multiplication operation by use of the Kerr medium exhibiting dual transverse electro-optic Kerr effect. In this kind of Kerr medium, electro-optic phase retardation is proportional to the square of its applied electric field, and orientations of the field-induced birefringent axes are only related to the direction of the field. Based on this effect, we can design an electro-optic multiplier by selecting the crystals of 6/mmm, 432, and m3m classes and isotropic Kerr media such as glass. Simple calculation demonstrates that a kind of glass-ceramic material with a large Kerr constant can be used for the design of the proposed electro-optic multiplier.

  8. Cascadable all-optical inverter based on a nonlinear vertical-cavity semiconductor optical amplifier.

    Science.gov (United States)

    Zhang, Haijiang; Wen, Pengyue; Esener, Sadik

    2007-07-01

    We report, for the first time to our knowledge, the operation of a cascadable, low-optical-switching-power(~10 microW) small-area (~100 microm(2)) high-speed (80 ps fall time) all-optical inverter. This inverter employs cross-gain modulation, polarization gain anisotropy, and highly nonlinear gain characteristics of an electrically pumped vertical-cavity semiconductor optical amplifier (VCSOA). The measured transfer characteristics of such an optical inverter resemble those of standard electronic metal-oxide semiconductor field-effect transistor-based inverters exhibiting high noise margin and high extinction ratio (~9.3 dB), making VCSOAs an ideal building block for all-optical logic and memory.

  9. Fullerene-Based Electron Transport Layers for Semi-Transparent MAPbBr3 Perovskite Films in Planar Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2016-10-01

    Full Text Available In this study, four kinds of structures—[6,6]-phenyl-C61-butyric acid methyl ester (PCBM, PCBM/fullerene (C60, C60/bathocuproine (BCP, and PCBM/C60/BCP—were used as electron transport layers, and the structure, and optical and electronic behaviors of MAPbBr3 perovskite layers after annealing treatments were observed. The experimental results indicate that PCBM/C60 bi-layer structure is acceptable for MAPbBr3 planar perovskite solar cells due to electron step transporting. Low-temperature annealing is suitable for smooth and large grain MAPbBr3 films. The semi-transparent yellow C60/PCBM/MAPbBr3/PEDOT:PSS/ITO glass-structure solar cells exhibit the best performance with a power conversion efficiency of 4.19%. The solar cells are revealed to be suitable for application in building integrated photovoltaic (BIPV systems.

  10. Fused Silica and Other Transparent Window Materials

    Science.gov (United States)

    Salem, Jon

    2016-01-01

    Several transparent ceramics, such as spinel and AlONs are now being produced in sufficient large areas to be used in space craft window applications. The work horse transparent material for space missions from Apollo to the International Space Station has been fused silica due in part to its low coefficient of expansion and optical quality. Despite its successful use, fused silica exhibits anomalies in its crack growth behavior, depending on environmental preconditioning and surface damage. This presentation will compare recent optical ceramics to fused silica and discuss sources of variation in slow crack growth behavior.

  11. Semitransparent inverted organic solar cell with improved absorption and reasonable transparency perception based on the nanopatterned MoO3/Ag/MoO3 anode

    Science.gov (United States)

    Tian, Ximin; Zhang, Ye; Hao, Yuying; Cui, Yanxia; Wang, Wenyan; Shi, Fang; Wang, Hua; Wei, Bin; Huang, Wei

    2015-01-01

    We demonstrate an inverted low bandgap semitransparent organic solar cell with improved absorption as well as reasonable transparency perception based on a nanopatterned MoO3/Ag/MoO3 (MAM) multilayer film as the transparent anode under illumination from the MAM side. The integrated absorption efficiency of the active layer at normal hybrid-polarized incidence considering an AM 1.5G solar spectrum is up to 51.69%, increased by 18.53% as compared to that of the equivalent planar device (43.61%) and reaching 77.3% of that of the corresponding opaque nanopatterned device (66.90%). Detailed investigations reveal that the excitation of plasmonic waveguide modes (at transverse magnetic polarization) and photonic modes (at transverse electric polarization) are responsible for the observed enhancement in absorption. Importantly, the proposed device exhibits an average transmittance of up to 28.4% and an average transparency perception of 26.3% for the human eyes under hybrid-polarized light illumination along with a good color rendering property. Additionally, our proposal works very well over a fairly wide angular range.

  12. Flexible optical network components based on densely integrated microring resonators

    NARCIS (Netherlands)

    Geuzebroek, D.H.

    2005-01-01

    This thesis addresses the design, realization and characterization of reconfigurable optical network components based on multiple microring resonators. Since thermally tunable microring resonators can be used as wavelength selective space switches, very compact devices with high complexity and

  13. A Compact, Waveguide Based Programmable Optical Comb Generator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA Phase I STTR effort will establish the feasibility of developing a compact broadband near to mid-IR programmable optical comb for use in laser based remote...

  14. Thermally stable, transparent, pressure-sensitive adhesives from epoxidized and dihydroxyl soybean oil.

    Science.gov (United States)

    Ahn, B Kollbe; Kraft, Stefan; Wang, D; Sun, X Susan

    2011-05-09

    Thermal stability and optical transparency are important factors for flexible electronics and heat-related applications of pressure-sensitive adhesives (PSAs). However, current acryl- and rubber-based PSAs cannot attain the required thermal stability, and silicon-based PSAs are much more expensive than the alternatives. Oleo-chemicals including functionalized plant oils have great potential to replace petrochemicals. In this study, novel biobased PSAs from soybean oils were developed with excellent thermal stability and transparency as well as peel strength comparable to current PSAs. In addition, the fast curing (drying) property of newly developed biobased PSAs is essential for industrial applications. The results show that soybean oil-based PSA films and tapes have great potential to replace petro-based PSAs for a broad range of applications including flexible electronics and medical devices because of their thermal stability, transparency, chemical resistance, and potential biodegradability from triglycerides.

  15. Chemical Design and Example of Transparent Bipolar Semiconductors.

    Science.gov (United States)

    Arai, Takeshi; Iimura, Soshi; Kim, Junghwan; Toda, Yoshitake; Ueda, Shigenori; Hosono, Hideo

    2017-11-29

    Transparent bipolar semiconductors (TBSCs) are in demand for transparent electronics to serve as the basis for next generation optoelectronic devices. However, the poor carrier controllability in wide-bandgap materials makes the realization of a bipolar nature difficult. Only two materials, CuInO 2 and SnO, have been reported as TBSCs. To satisfy demand for the coexistence of transparency and bipolarity, we propose a design concept with three strategies; choice of early transition metals (eTM) such as Y 3+ and Zr 4+ for improving controllability of carrier doping, design of chemical bonds to obtain an appropriate band structure for bipolar doping, and use of a forbidden band-edge transition to retain transparency. This approach is verified through a practical examination of a candidate material, tetragonal ZrOS, which is chosen by following the criteria. ZrOS exhibits an excellent controllability of the electrical conductivity (10 -7 -10 -2 S cm -1 ), p- or n-type nature with ∼10 -2 S cm -1 by Y or F doping, respectively, and optically wide gap (below 10 -4 cm -1 up to ∼2.5 eV). This concept provides a new kind of TBSC based on eTM ionic compounds.

  16. Optical Flow based Robot Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Kahlouche Souhila

    2008-11-01

    Full Text Available In this paper we try to develop an algorithm for visual obstacle avoidance of autonomous mobile robot. The input of the algorithm is an image sequence grabbed by an embedded camera on the B21r robot in motion. Then, the optical flow information is extracted from the image sequence in order to be used in the navigation algorithm. The optical flow provides very important information about the robot environment, like: the obstacles disposition, the robot heading, the time to collision and the depth. The strategy consists in balancing the amount of left and right side flow to avoid obstacles, this technique allows robot navigation without any collision with obstacles. The robustness of the algorithm will be showed by some examples.

  17. Development of theoretical oxygen saturation calibration curve based on optical density ratio and optical simulation approach

    Science.gov (United States)

    Jumadi, Nur Anida; Beng, Gan Kok; Ali, Mohd Alauddin Mohd; Zahedi, Edmond; Morsin, Marlia

    2017-09-01

    The implementation of surface-based Monte Carlo simulation technique for oxygen saturation (SaO2) calibration curve estimation is demonstrated in this paper. Generally, the calibration curve is estimated either from the empirical study using animals as the subject of experiment or is derived from mathematical equations. However, the determination of calibration curve using animal is time consuming and requires expertise to conduct the experiment. Alternatively, an optical simulation technique has been used widely in the biomedical optics field due to its capability to exhibit the real tissue behavior. The mathematical relationship between optical density (OD) and optical density ratios (ODR) associated with SaO2 during systole and diastole is used as the basis of obtaining the theoretical calibration curve. The optical properties correspond to systolic and diastolic behaviors were applied to the tissue model to mimic the optical properties of the tissues. Based on the absorbed ray flux at detectors, the OD and ODR were successfully calculated. The simulation results of optical density ratio occurred at every 20 % interval of SaO2 is presented with maximum error of 2.17 % when comparing it with previous numerical simulation technique (MC model). The findings reveal the potential of the proposed method to be used for extended calibration curve study using other wavelength pair.

  18. XBRL and Financial Reporting Transparency

    Directory of Open Access Journals (Sweden)

    Mihaela Enachi

    2013-02-01

    Full Text Available Using eXtensible Business Reporting Language (XBRL in financial reporting increases transparency by allowing viewing the details of the information provided by organizations without subdividing it and the possibility of easy access and processing information, even if it is presented in different languages or it results from the application of different regulations. Through this paper we try to emphasize the transparency ensured to financial reporting by using XBRL, which is why wetransposed in this modern format, partially, the contents of one of the components of financial reports, namely, the balance sheet. In this process we based on the requirements of the Romanian accountingregulations in compliance with European directives, XML requirements and XBRL requirements concerning schemas, linkbase files and instances, and we used three of the modules of Altova MissionKit application (XMLSpy, MapForce and StyleVision, while taking into account the best practices in the field.Keywords: financial reporting, XBRL, transparency, specification, taxonomy, instance

  19. Transparent stereoscopic display and application

    Science.gov (United States)

    Ranieri, Nicola; Seifert, Hagen; Gross, Markus

    2014-03-01

    Augmented reality has become important to our society as it can enrich the actual world with virtual information. Transparent screens offer one possibility to overlay rendered scenes with the environment, acting both as display and window. In this work, we review existing transparent back-projection screens for the use with active and passive stereo. Advantages and limitations are described and, based on these insights, a passive stereoscopic system using an anisotropic back-projection foil is proposed. To increase realism, we adapt rendered content to the viewer's position using a Kinect tracking system, which adds motion parallax to the binocular cues. A technique well known in control engineering is used to decrease latency and increase frequency of the tracker. Our transparent stereoscopic display prototype provides immersive viewing experience and is suitable for many augmented reality applications.

  20. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)