Sample records for cell light scattering

  1. Biological cell classification by multiangle light scattering (United States)

    Salzman, G.C.; Crowell, J.M.; Mullaney, P.F.


    The specification is directed to an apparatus and method for detecting light scattering from a biological cell. Light, preferably from a coherent source of radiation, intercepts an individual biological cell in a stream of cells passing through the beam. Light scattered from the cell is detected at a selected number of angles between 0 and 90/sup 0/ to the longitudinal axis of the beam with a circular array of light responsive elements which produce signals representative of the intensity of light incident thereon. Signals from the elements are processed to determine the light-scattering pattern of the cell and therefrom its identity.

  2. Light scattering by aggregated red blood cells (United States)

    Tsinopoulos, Stephanos V.; Sellountos, Euripides J.; Polyzos, Demosthenes


    In low flow rates, red blood cells (RBCs) fasten together along their axis of symmetry and form a so-called rouleaux. The scattering of He-Ne laser light by a rouleau consisting of n (2 less-than-or-equal n less-than-or-equal 8) average-sized RBCs is investigated. The interaction problem is treated numerically by means of an advanced axisymmetric boundary element--fast Fourier transform methodology. The scattering problem of one RBC was solved first, and the results showed that the influence of the RBC's membrane on the scattering patterns is negligible. Thus the rouleau is modeled as an axisymmetric, homogeneous, low-contrast dielectric cylinder, on the surface of which appears, owing to aggregated RBCs, a periodic roughness along the direction of symmetry. The direction of the incident laser light is considered to be perpendicular to the scatterer's axis of symmetry. The differential scattering cross sections in both perpendicular and parallel scattering planes and for all the scattering angles are calculated and presented in detail.

  3. Backward elastic light scattering of malaria infected red blood cells (United States)

    Lee, Seungjun; Lu, Wei


    We investigated the backward light scattering pattern of healthy and malaria (Plasmodium falciparum) parasitized red blood cells. The spectrum could clearly distinguish between predominant ring stage infected blood cells and healthy blood cells. Further, we found that infected samples mixed with different stages of P. falciparum showed different signals, suggesting that even variance in parasite stages could also be detected by the spectrum. These results together with the backward scattering technique suggest the potential of non-invasive diagnosis of malaria through light scattering of blood cells near the surface of human body, such as using eyes or skin surface.

  4. Comparative Study of Light Scattering from Hepatoma Cells and Hepatocytes (United States)

    Lin, Xiaogang; Wang, Rongrong; Guo, Yongcai; Gao, Chao; Guo, Xiaoen


    Primary liver cancer is one of the highest mortality malignant tumors in the world. China is a high occurrence area of primary liver cancer. Diagnosis of liver cancer, especially early diagnosis, is essential for improving patients' survival. Light scattering and measuring method is an emerging technology developed in recent decades, which has attracted a large number of biomedical researchers due to its advantages, such as fast, simple, high accuracy, good repeatability, and non-destructive. The hypothesis of this project is that there may be some different light scattering information between hepatoma cells and hepatocyte. Combined with the advantages of the dynamic light scattering method and the biological cytology, an experimental scheme to measure the light scattering information of cells was formulated. Hepatoma cells and hepatic cells were irradiated by a semiconductor laser (532 nm). And the Brookhaven BI-200SM wide-angle light scattering device and temperature control apparatus were adopted. The light scattering information of hepatoma cells and hepatic cells in vitro within the 15°C to 30°C temperature range was processed by a BI-9000AT digital autocorrelator. The following points were found: (a) the scattering intensities of human hepatic cells and hepatoma cells are nearly not affected by the temperature factor, and the former is always greater than the latter and (b) the relaxation time of hepatoma cells is longer than that of hepatic cells, and both the relaxation time are shortened with increasing temperature from 15°C to 25°C. It can be concluded that hepatoma cells could absorb more incident light than hepatic cells. The reason may be that there exists more protein and nucleic acid in cancerous cells than normal cells. Furthermore, based on the length relaxation time, a conclusion can be inferred that the Brownian movement of cancer cells is greater.

  5. Adenovirus Particle Quantification in Cell Lysates Using Light Scattering. (United States)

    Hohl, Adrian; Ramms, Anne Sophie; Dohmen, Christian; Mantwill, Klaus; Bielmeier, Andrea; Kolk, Andreas; Ruppert, Andreas; Nawroth, Roman; Holm, Per Sonne


    Adenoviral vector production for therapeutic applications is a well-established routine process. However, current methods for measurement of adenovirus particle titers as a quality characteristic require highly purified virus preparations. While purified virus is typically obtained in the last step of downstream purification, rapid and reliable methods for adenovirus particle quantification in intermediate products and crude lysates to allow for optimization and validation of cell cultures and intermediate downstream processing steps are currently not at hand. Light scattering is an established process to measure virus particles' size, though due to cell impurities, adequate quantification of adenovirus particles in cell lysates by light scattering has been impossible until today. This report describes a new method using light scattering to measure virus concentration in nonpurified cell lysates. Here we report application of light scattering, a routine method to measure virus particle size, to virus quantification in enzymatically conditioned crude lysates. Samples are incubated with phospholipase A2 and benzonase and filtered through a 0.22 μm filter cartridge prior to quantification by light scattering. Our results show that this treatment provides a precise method for fast and easy determination of total adenovirus particle numbers in cell lysates and is useful to monitor virus recovery throughout all downstream processing.

  6. Optical Imaging of Cells with Gold Nanoparticle Clusters as Light Scattering Contrast Agents

    DEFF Research Database (Denmark)

    Tanev, Stoyan


    This chapter has two main objectives. First, to review a number of examples illustrating the application of the FDTD approach to the modeling of some typical light scattering configurations that could be associated with flow cytometry. Second, to provide a thorough discussion of these new...... developments in advanced cytometry research by pointing out potential new research directions. A brief description of the FDTD method focusing on the features associated with its application to modeling of light scattering and OPCM cell imaging experiments is provided. The examples include light scattering...

  7. Flow microfluorometric and light-scatter measurement of nuclear and cytoplasmic size in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Steinkamp, J.A.; Hansen, K.M.; Crissman, H.A.


    A technique for rapid measurement of nuclear and cytoplasmic size relationships in mammalian cell populations has been developed. Based on fluorescence staining of either the nucleus alone or in combination with the cytoplasm using two-color fluorescence methods, this technique permits the simultaneous determination of nuclear and cytoplasmic diameters from fluorescence and light-scatter measurements. Cells stained in liquid suspension pass through a flow chamber at a constant velocity, intersecting a laser beam which excites cell fluorescence and causes light scatter. Depending upon which analysis procedure is used, optical sensors measure nuclear fluorescence and light scatter (whole cell size) or two-color nuclear and cytoplasmic fluorescence from individual cells crossing the laser beam. The time durations of signals generated by the nucleus and cytoplasm are converted electronically into signals proportional to the respective diameters and are displayed as frequency distribution histograms. Illustrative examples of measurements on uniform microspheres, cultured mammalian cells and human exfoliated gynecologic cells are presented.

  8. The measurement and modelling of light scattering by phytoplankton cells at narrow forward angles (United States)

    MacCallum, Iain; Cunningham, Alex; McKee, David


    A procedure has been devised for measuring the angular dependence of light scattering from suspensions of phytoplankton cells at forward angles from 0.25° to 8°. The cells were illuminated with a spatially-filtered laser beam and the angular distribution of scattered light measured by tracking a photodetector across the Fourier plane of a collecting lens using a stepper-motor driven stage. The procedure was calibrated by measuring scattering from latex bead suspensions with known size distributions. It was then used to examine the scattering from cultures of the unicellular algae Isochrysis galbana (4 µm × 5 µm), Dunaliella primolecta (6 µm × 7 µm) and Rhinomonas reticulata (5 µm × 11 µm). The results were compared with the predictions of Mie theory. Excellent agreement was obtained for spherical particles. A suitable choice of spherical-equivalent scattering parameters was required to enable reasonable agreement within the first diffraction lobe for ellipsoidal particles.

  9. Flow cytometry of human embryonic kidney cells: A light scattering approach (United States)

    Kunze, M. E.; Goolsby, C. L.; Todd, P. W.; Morrison, D. R.; Lewis, M. L.


    The mammalian kidney contains cells that transport water, convert vitamin D to active forms, synthesize hormones such a renin and erythropoietin, and produce enzymes such as urokinase, a plasminogen activator. Several of these functions are maintained by human embryonic kidney cells (HEK) cultivated in vitro. Biochemical study of these functions in their individual cell types in vitro requires purified populations of cells. Light-scattering activated cell sorting (LACS) was explored as a means of achieving such purifications. It was found that HEK cells at the first 1 to 5 passages in culture were heterogeneous with respect to 2-parameter light scattering intensity distribution, in which combined measurements included forward angle scattering (2.5 to 19 deg), 90 deg scattering, and time-of-flight size measurements. Size was measured at a resolution of 0.15 microns/channel in 256 channels using pulse-height independent pulse-width measurements. Two-parameter distributions combining these measurements were obtained for HEK cell subpopulations that had been purified by microgravity electrophoresis and subsequently propagated in culture. These distributions contained at least 3 subpopulations in all purified fractions, and results of experiments with prepurified cultured HEK cells indicated that subpopulations of living cells that were high in plasminogen-activator activity also contained the highest per cent of cells with high 90 deg light scatter intensity.

  10. Detection of internal structure by scattered light intensity: Application to kidney cell sorting (United States)

    Goolsby, C. L.; Kunze, M. E.


    Scattered light measurements in flow cytometry were sucessfully used to distinguish cells on the basis of differing morphology and internal structure. Differences in scattered light patterns due to changes in internal structure would be expected to occur at large scattering angles. Practically, the results of these calculations suggest that in experimental situations an array of detectors would be useful. Although in general the detection of the scattered light intensity at several intervals within the 10 to 60 region would be sufficient, there are many examples where increased sensitivity could be acheived at other angles. The ability to measure at many different angular intervals would allow the experimenter to empirically select the optimum intervals for the varying conditions of cell size, N/C ratio, granule size and internal structure from sample to sample. The feasibility of making scattered light measurements at many different intervals in flow cytometry was demonstrated. The implementation of simplified versions of these techniques in conjunction with independant measurements of cell size could potentially improve the usefulness of flow cytometry in the study of the internal structure of cells.

  11. Four-Parameter white blood cell differential counting based on light scattering measurements

    NARCIS (Netherlands)

    Terstappen, Leonardus Wendelinus Mathias Marie; de Grooth, B.G.; Visscher, K.; Kouterik, F.A.; Greve, Jan


    Measurement of the depolarized orthogonal light scattering in flow cytometry enables one to discriminate human eosinephilic granulocytes from neutrophilic granulocytes. We use this method to perform a four-parameter differential white blood cell analysis. A simple flow cytometer was built equipped

  12. Study of light scattering by a granulated coated sphere - a model of granulated blood cells

    NARCIS (Netherlands)

    Yurkin, M.A.; de Kanter, D.; Hoekstra, A.G.


    We performed extensive simulations of light scattering by granulated coated sphere model using the discrete dipole approximation and varying model parameters in the ranges of sizes and refractive indices of granulated blood cells. We compared these results with predictions of Maxwell-Garnett

  13. Synthetic Fourier transform light scattering. (United States)

    Lee, Kyeoreh; Kim, Hyeon-Don; Kim, Kyoohyun; Kim, Youngchan; Hillman, Timothy R; Min, Bumki; Park, Yongkeun


    We present synthetic Fourier transform light scattering, a method for measuring extended angle-resolved light scattering (ARLS) from individual microscopic samples. By measuring the light fields scattered from the sample plane and numerically synthesizing them in Fourier space, the angle range of the ARLS patterns is extended up to twice the numerical aperture of the imaging system with unprecedented sensitivity and precision. Extended ARLS patterns of individual microscopic polystyrene beads, healthy human red blood cells (RBCs), and Plasmodium falciparum-parasitized RBCs are presented.

  14. Dielectric Scattering Patterns for Efficient Light Trapping in Thin-Film Solar Cells. (United States)

    van Lare, Claire; Lenzmann, Frank; Verschuuren, Marc A; Polman, Albert


    We demonstrate an effective light trapping geometry for thin-film solar cells that is composed of dielectric light scattering nanocavities at the interface between the metal back contact and the semiconductor absorber layer. The geometry is based on resonant Mie scattering. It avoids the Ohmic losses found in metallic (plasmonic) nanopatterns, and the dielectric scatterers are well compatible with nearly all types of thin-film solar cells, including cells produced using high temperature processes. The external quantum efficiency of thin-film a-Si:H solar cells grown on top of a nanopatterned Al-doped ZnO, made using soft imprint lithography, is strongly enhanced in the 550-800 nm spectral band by the dielectric nanoscatterers. Numerical simulations are in good agreement with experimental data and show that resonant light scattering from both the AZO nanostructures and the embedded Si nanostructures are important. The results are generic and can be applied on nearly all thin-film solar cells.

  15. Quantitative analysis of gold and carbon nanoparticles in mammalian cells by flow cytometry light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Gang [Nanjing University, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences (China); Liu, Naicheng; Wang, Zhenheng [Nanjing University, Department of Orthopedics, Jinling Hospital, School of Medicine (China); Shi, Tongguo; Gan, Jingjing; Wang, Zhenzhen; Zhang, Junfeng, E-mail: [Nanjing University, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences (China)


    Nanoparticle-based applications for diagnostics and therapeutics have been extensively studied. These applications require a profound understanding of the fate of nanoparticles (NPs) in cellular environments. However, until now, few analytical methods are available and most of them rely on fluorescent properties or special elements of NPs; therefore, for NPs without observable optical properties or special elements, the existing methods are hardly applicable. In this study, we introduce a flow cytometry light scattering (FCLS)-based approach that quantifies in situ NPs accurately in mammalian cells. Continuous cells of heterogeneous human epithelial colorectal adenocarcinoma (Caco-2 cells), mouse peritoneal macrophages (MPM), and human adenocarcinomic alveolar basal epithelia (A549 cells) were cultured with NPs with certain concentrations and size. The intensity of the flow cytometric side scattered light, which indicates the quantity of NPs in the cells, was analyzed. The result shows an accurate size- and dose-dependent uptake of Au NPs (5, 30, 250 nm) in Caco-2 cells. The size- and dose- dependence of Au NPs (5, 30, 250 nm) and carbon NPs (50, 500 nm) in cells was validated by transmission electron microscope (TEM). This paper demonstrates the great potential of flow cytometry light scattering in the quantitative study of the size and dose effect on in situ metallic or non-metallic NPs in mammalian cells.

  16. Quantitative analysis of gold and carbon nanoparticles in mammalian cells by flow cytometry light scattering (United States)

    Zhou, Gang; Liu, Naicheng; Wang, Zhenheng; Shi, Tongguo; Gan, Jingjing; Wang, Zhenzhen; Zhang, Junfeng


    Nanoparticle-based applications for diagnostics and therapeutics have been extensively studied. These applications require a profound understanding of the fate of nanoparticles (NPs) in cellular environments. However, until now, few analytical methods are available and most of them rely on fluorescent properties or special elements of NPs; therefore, for NPs without observable optical properties or special elements, the existing methods are hardly applicable. In this study, we introduce a flow cytometry light scattering (FCLS)-based approach that quantifies in situ NPs accurately in mammalian cells. Continuous cells of heterogeneous human epithelial colorectal adenocarcinoma (Caco-2 cells), mouse peritoneal macrophages (MPM), and human adenocarcinomic alveolar basal epithelia (A549 cells) were cultured with NPs with certain concentrations and size. The intensity of the flow cytometric side scattered light, which indicates the quantity of NPs in the cells, was analyzed. The result shows an accurate size- and dose-dependent uptake of Au NPs (5, 30, 250 nm) in Caco-2 cells. The size- and dose- dependence of Au NPs (5, 30, 250 nm) and carbon NPs (50, 500 nm) in cells was validated by transmission electron microscope (TEM). This paper demonstrates the great potential of flow cytometry light scattering in the quantitative study of the size and dose effect on in situ metallic or non-metallic NPs in mammalian cells.

  17. Diagnostic features in two-dimensional light scattering patterns of normal and dysplastic cervical cell nuclei (United States)

    Arifler, Dizem; MacAulay, Calum; Follen, Michele; Guillaud, Martial


    Dysplastic progression in epithelial tissues is linked to changes in morphology and internal structure of cell nuclei. These changes lead to alterations in nuclear light scattering profiles that can potentially be monitored for diagnostic purposes. Numerical tools allow for simulation of complex nuclear models and are particularly useful for quantifying the optical response of cell nuclei as dysplasia progresses. In this study, we first analyze a set of quantitative histopathology images from twenty cervical biopsy sections stained with Feulgen-thionin. Since Feulgen-thionin is stoichiometric for DNA, the images enable us to obtain detailed information on size, shape, and chromatin content of all the segmented nuclei. We use this extensive data set to construct realistic three-dimensional computational models of cervical cell nuclei that are representative of four diagnostic categories, namely normal or negative for dysplasia, mild dysplasia, moderate dysplasia, and severe dysplasia or carcinoma in situ (CIS). We then carry out finite-difference time-domain simulations to compute the light scattering response of the constructed models as a function of the polar scattering angle and the azimuthal scattering angle. The results show that these two-dimensional scattering patterns exhibit characteristic intensity ridges that change form with progression of dysplasia; pattern processing reveals that Haralick features can be used to distinguish moderately and severely dysplastic or CIS nuclei from normal and mildly dysplastic nuclei. Our numerical study also suggests that different angular ranges need to be considered separately to fully exploit the diagnostic potential of two-dimensional light scattering measurements.

  18. Flow cytometry with gold nanoparticlesand their clusters as scattering contrast agents: FDTD simulation of light-cell interaction

    DEFF Research Database (Denmark)

    Tanev, Stoyan; Sun, Wenbo; Pond, James


    The formulation of the Finite-Difference Time-Domain (FDTD) approach is presented in the framework of its potential applications to in vivo flow cytometry based on light scattering. The consideration is focused on comparison of light scattering by a single biological cell alone in controlled refr...

  19. 2D light scattering static cytometry for label-free single cell analysis with submicron resolution. (United States)

    Xie, Linyan; Yang, Yan; Sun, Xuming; Qiao, Xu; Liu, Qiao; Song, Kun; Kong, Beihua; Su, Xuantao


    Conventional optical cytometric techniques usually measure fluorescence or scattering signals at fixed angles from flowing cells in a liquid stream. Here we develop a novel cytometer that employs a scanning optical fiber to illuminate single static cells on a glass slide, which requires neither microfluidic fabrication nor flow control. This static cytometric technique measures two dimensional (2D) light scattering patterns via a small numerical aperture (0.25) microscope objective for label-free single cell analysis. Good agreement is obtained between the yeast cell experimental and Mie theory simulated patterns. It is demonstrated that the static cytometer with a microscope objective of a low resolution around 1.30 μm has the potential to perform high resolution analysis on yeast cells with distributed sizes. The capability of the static cytometer for size determination with submicron resolution is validated via measurements on standard microspheres with mean diameters of 3.87 and 4.19 μm. Our 2D light scattering static cytometric technique may provide an easy-to-use, label-free, and flow-free method for single cell diagnostics. © 2015 International Society for Advancement of Cytometry.

  20. Light absorption enhancement in thin-film GaAs solar cells with flattened light scattering substrates (United States)

    Sai, Hitoshi; Mizuno, Hidenori; Makita, Kikuo; Matsubara, Koji


    A flattened light scattering substrate (FLiSS) was investigated for enhancing the light absorption in thin-film GaAs solar cells. The FLiSS investigated in this work was limited to those composed of periodic refractive index distribution, although its concept is not necessarily limited to such a structure. The following guidelines were found via optical simulation: (i) the morphological distribution of refractive indices in a FLiSS plays a key role, and an inverted pyramid-like shape is very efficient in light scattering. (ii) There are an optimum period and a depth in a FLiSS, although efficient light scattering is achievable in a wide parameter space. However, periods less than 0.4 μm result in poor light scattering effect. (iii) The contrast in the refractive indices of the two materials in the FLiSS should be large enough, typically Δn > 1.5. At the same time, parasitic absorption loss in the FLiSS must be minimized. An optimized FLiSS, which satisfies the requirements mentioned above, can increase the absorption in thin GaAs cells more efficiently than a flat reflector, and a high current density of approximately 30 mA/cm2 is potentially achievable with a 1-μm-thick absorber. For experimental verification, a 2D grating FLiSS with InZnO and amorphous Si was developed and applied to thin film GaAs solar cells. As a result, a significant increase in the current density as well as in the spectral response in a long wavelength region was demonstrated, as expected from the optical simulation.

  1. Transparency Effect of Electrolyte on Light Back-Scattering in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    N. Sharifi


    Full Text Available Conventionally, a film of TiO2 particles of ~300 nm size is employed in DSCs as the back reflector film to enhance the light harvesting. In this study, two electrolytes with different transparencies, iodide-based and cobalt-based electrolytes, were used to investigate the transparency effect of electrolytes on light back-scattering from back scattering layer and also to study its effect on the performance of DSCs. The use of cobalt-based electrolyte is recommended from the view point of optical properties as due to the light absorption in electrolytes, the current density losses are 2.9mA/cm2 and 4.2 mA/cm2 in cobalt- and iodide-based electrolytes, respectively, and the transmission of 100% is observed for cobalt-based electrolyte in 500-600 nm in spite of iodide-based electrolyte. Use of light back-scattering layer, unlike iodide-based cell, causes external quantum efficiency in cobalt-base cell to increase for the wavelengths lower than 350 nm since cobalt-base electrolyte has transparency in this region. In addition, optical calculations demonstrate that in the range 400-500 nm, in which dye has a noticeable absorption, absorption loss is 40% and 30% for iodide- and cobalt-based electrolytes, respectively.

  2. Cell light scattering characteristic numerical simulation research based on FDTD algorithm (United States)

    Lin, Xiaogang; Wan, Nan; Zhu, Hao; Weng, Lingdong


    In this study, finite-difference time-domain (FDTD) algorithm has been used to work out the cell light scattering problem. Before beginning to do the simulation contrast, finding out the changes or the differences between normal cells and abnormal cells which may be cancerous or maldevelopment is necessary. The preparation of simulation are building up the simple cell model of cell which consists of organelles, nucleus and cytoplasm and setting up the suitable precision of mesh. Meanwhile, setting up the total field scattering field source as the excitation source and far field projection analysis group is also important. Every step need to be explained by the principles of mathematic such as the numerical dispersion, perfect matched layer boundary condition and near-far field extrapolation. The consequences of simulation indicated that the position of nucleus changed will increase the back scattering intensity and the significant difference on the peak value of scattering intensity may result from the changes of the size of cytoplasm. The study may help us find out the regulations based on the simulation consequences and the regulations can be meaningful for early diagnosis of cancers.

  3. Plasmonic Light Scattering in Textured Silicon Solar Cells with Indium Nanoparticles from Normal to Non-Normal Light Incidence

    Directory of Open Access Journals (Sweden)

    Wen-Jeng Ho


    Full Text Available In this study, we sought to improve the light trapping of textured silicon solar cells using the plasmonic light scattering of indium nanoparticles (In NPs of various dimensions. The light trapping modes of textured-silicon surfaces with and without In NPs were investigated at an angle of incidence (AOI ranging from 0° to 75°. The optical reflectance, external quantum efficiency (EQE, and photovoltaic performance were first characterized under an AOI of 0°. We then compared the EQE and photovoltaic current density-voltage (J-V as a function of AOI in textured silicon solar cells with and without In NPs. We observed a reduction in optical reflectance and an increase in EQE when the cells textured with pyramidal structures were coated with In NPs. We also observed an impressive increase in the average weighted external quantum efficiency (∆EQEw and short-circuit current-density (∆Jsc in cells with In NPs when illuminated under a higher AOI. The ∆EQEw values of cells with In NPs were 0.37% higher than those without In NPs under an AOI of 0°, and 3.48% higher under an AOI of 75°. The ∆Jsc values of cells with In NPs were 0.50% higher than those without In NPs under an AOI of 0°, and 4.57% higher under an AOI of 75°. The application of In NPs clearly improved the light trapping effects. This can be attributed to the effects of plasmonic light-scattering over the entire wavelength range as well as an expanded angle of incident light.

  4. Plasmonic scattering nanostructures for efficient light trapping in flat CZTS solar cells (United States)

    Abdelraouf, Omar A. M.; Abdelrahaman, M. Ismail; Allam, Nageh K.


    CZTS (Cu2ZnSnS4) is a promising absorbing layer in photovoltaic devices, due to it is low cost, abundancy, and non-toxicity. However, recent developments in CZTS solar cells showed efficiency reaching barely over 9%. The low efficiency of CZTS solar cells is the main obstacle for replacing conventional high cost bulk silicon photovoltaic with CZTS solar cells. Herein, we propose an alternative route for enhancing the efficiency of CZTS solar cells by using plasmonic scattering nanostructures on the top surface of the CZTS active layer. Metamaterial and plasmonic nanostructures can confine, absorb, guide or scatter incident light in the nanoscale. Each one of these phenomena totally depends on the material type, shape, and geometrical dimensions of the used nanostructures. Therefore, theoretical study of different shapes and materials can guide the highest performance of desired phenomena. In this work, we studied the effect of changing plasmonic metal nanopyramids height, periodicity, and tapering angle on light scattering inside active layer of the CZTS solar cells. By sweeping pyramids height from 100nm to 300nm, periodicity of closed nanopyramids from 100nm to 180nm, and using pyramid base length 25nm, 50nm, 75nm, we found good enhancements in light absorption inside the active layer over reference planar CZTS structures. Each plasmonic CZTS solar cell structure is designed and analyzed using there dimensional (3D) finite element method (FEM) simulations. Using periodic boundary condition for simulating a smaller cell, and with mesh size is ten times smaller than lowest simulated wavelength. Input port energy came from air mass 1.5 sun light over wavelength range from 300nm to 800nm. Also, we studied effect of replacing molybdenum with refractory plasmonics titanium nitride (TiN). TiN is a promising plasmonic material as it has a similar plasmonic properties to gold at visible wavelength. After using TiN, we found also enhancements in light absorption. These

  5. Kinetics of red blood cell rouleaux formation studied by light scattering (United States)

    Szołna-Chodór, Alicja; Bosek, Maciej; Grzegorzewski, Bronisław


    Red blood cell (RBC) rouleaux formation was experimentally studied using a light scattering technique. The suspensions of RBCs were obtained from the blood of healthy donors. Hematocrit of the samples was adjusted ranging from 1% to 4%. Measurements of the intensity of the coherent component of light scattered by the suspensions were performed and the scattering coefficient of the suspensions was determined. The number of RBCs per rouleaux was obtained using anomalous diffraction theory. The technique was used to show the effect of time, hematocrit, and sample thickness on the process. The number of cells per rouleaux first increases linearly, reaches a critical value at ˜3 cells per rouleaux, and then a further increase in the rouleaux size is observed. The kinetic constant of the rouleaux growth in the linear region is found to be independent of hematocrit. The aggregation rate increases as the sample thickness increases. The time at which the critical region appears strongly decreases as the hematocrit of the suspension increases.

  6. Light scattering reviews 8 radiative transfer and light scattering

    CERN Document Server

    Kokhanovsky, Alexander A


    Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

  7. Light Scattering Spectroscopy: From Elastic to Inelastic (United States)

    Perelman, Lev T.; Modell, Mark D.; Vitkin, Edward; Hanlon, Eugene B.

    This chapter reviews light scattering spectroscopic techniques in which coherent effects are critical because they define the structure of the spectrum. In the case of elastic light scattering spectroscopy, the targets themselves, such as aerosol particles in environmental science or cells and subcellular organelles in biomedical applications, play the role of microscopic optical resonators. In the case of inelastic light scattering spectroscopy or Raman spectroscopy, the spectrum is created due to light scattering from vibrations in molecules or optical phonons in solids. We will show that light scattering spectroscopic techniques, both elastic and inelastic, are emerging as very useful tools in material and environmental science and in biomedicine.

  8. Critical fluid light scattering (United States)

    Gammon, Robert W.


    The objective is to measure the decay rates of critical density fluctuations in a simple fluid (xenon) very near its liquid-vapor critical point using laser light scattering and photon correlation spectroscopy. Such experiments were severely limited on Earth by the presence of gravity which causes large density gradients in the sample when the compressibility diverges approaching the critical point. The goal is to measure fluctuation decay rates at least two decades closer to the critical point than is possible on earth, with a resolution of 3 microK. This will require loading the sample to 0.1 percent of the critical density and taking data as close as 100 microK to the critical temperature. The minimum mission time of 100 hours will allow a complete range of temperature points to be covered, limited by the thermal response of the sample. Other technical problems have to be addressed such as multiple scattering and the effect of wetting layers. The experiment entails measurement of the scattering intensity fluctuation decay rate at two angles for each temperature and simultaneously recording the scattering intensities and sample turbidity (from the transmission). The analyzed intensity and turbidity data gives the correlation length at each temperature and locates the critical temperature. The fluctuation decay rate data from these measurements will provide a severe test of the generalized hydrodynamic theories of transport coefficients in the critical regions. When compared to equivalent data from binary liquid critical mixtures they will test the universality of critical dynamics.

  9. Physical discrimination between human T-lymphocyte subpopulations by means of light scattering, revealing two populations of T8-positive cells

    NARCIS (Netherlands)

    Terstappen, Leonardus Wendelinus Mathias Marie; de Grooth, B.G.; Nolten, G.M.J.; ten Napel, C.H.H.; van Berkel, W.; Greve, Jan


    Light-scattering properties of human T-lymphocyte subpopulations selected by immunofluorescence were studied. Based on differences in orthogonal light scattering, two subpopulations of T8-positive cells can be distinguished. The first population (T8a) has the same orthogonal light-scattering

  10. Non-label bioimaging utilizing scattering lights (United States)

    Watanabe, Tomonobu M.; Ichimura, Taro; Fujita, Hideaki


    Optical microscopy is an indispensable tool for medical and life sciences. Especially, the microscopes utilized with scattering light offer a detailed internal observation of living specimens in real time because of their non-labeling and non-invasive capability. We here focus on two kinds of scattering lights, Raman scattering light and second harmonic generation light. Raman scattering light includes the information of all the molecular vibration modes of the molecules, and can be used to distinguish types and/or state of cell. Second harmonic generation light is derived from electric polarity of proteins in the specimen, and enables to detect their structural change. In this conference, we would like to introduce our challenges to extract biological information from those scattering lights.

  11. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.


    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  12. Influence of structural length-scale variations on azimuth-resolved light scattering patterns of inhomogeneous cell models (United States)

    Arifler, Dizem; Guillaud, Martial


    Optical scattering provides an intrinsic contrast mechanism for the diagnosis of early precancerous changes in tissues. There have been a multitude of numerical studies targeted at delineating the relationship between cancer-related alterations in morphology and internal structure of cells and the resulting changes in their optical scattering properties. Despite these efforts, we still need to further our understanding of inherent scattering signatures that can be linked to precancer progression. As such, computational studies aimed at relating electromagnetic wave interactions to cellular and subcellular structural alterations are likely to provide a quantitative framework for a better assessment of the diagnostic content of optical signals. In this study, we aim to determine the influence of structural length-scale variations on two-dimensional light scattering properties of cells. We numerically construct cell models with different lower bounds on the size of refractive index heterogeneities and we employ the finite-difference time-domain method to compute their azimuth-resolved light scattering patterns. The results indicate that changes in length-scale variations can significantly alter the two-dimensional scattering patterns of cell models. More specifically, the degree of azimuthal asymmetry characterizing these patterns is observed to be highly dependent on the range of length-scale variations. Overall, the study described here is expected to offer useful insights into whether azimuth-resolved measurements can be explored for diagnostic purposes.

  13. Light scattering by small particles

    CERN Document Server

    Hulst, H C van de


    ""A must for researchers using the techniques of light scattering."" ? S. C. Snowdon, Journal of the Franklin InstituteThe measurement of light scattering of independent, homogeneous particles has many useful applications in physical chemistry, meteorology and astronomy. There is, however, a sizeable gap between the abstract formulae related to electromagnetic-wave-scattering phenomena, and the computation of reliable figures and curves. Dr. van de Hulst's book enables researchers to bridge that gap. The product of twelve years of work, it is an exhaustive study of light-scattering properties

  14. Improved light trapping in microcrystalline silicon solar cells by plasmonic back reflector with broad angular scattering and low parasitic absorption

    NARCIS (Netherlands)

    Tan, H.; Sivec, L.; Yan, B.; Santbergen, R.; Zeman, M.; Smets, A.H.M.


    We show experimentally that the photocurrent of thin-film hydrogenated microcrystalline silicon (?c-Si:H) solar cells can be enhanced by 4.5?mA/cm2 with a plasmonic back reflector (BR). The light trapping performance is improved using plasmonic BR with broader angular scattering and lower parasitic

  15. Flow cytometry with gold nanoparticles and their clusters as scattering contrast agents: FDTD simulation of light-cell interaction. (United States)

    Tanev, Stoyan; Sun, Wenbo; Pond, James; Tuchin, Valery V; Zharov, Vladimir P


    The formulation of the finite-difference time-domain (FDTD) approach is presented in the framework of its potential applications to in-vivo flow cytometry based on light scattering. The consideration is focused on comparison of light scattering by a single biological cell alone in controlled refractive-index matching conditions and by cells labeled by gold nanoparticles. The optical schematics including phase contrast (OPCM) microscopy as a prospective modality for in-vivo flow cytometry is also analyzed. The validation of the FDTD approach for the simulation of flow cytometry may open up a new avenue in the development of advanced cytometric techniques based on scattering effects from nanoscale targets. 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  16. Light scattering reviews 9 light scattering and radiative transfer

    CERN Document Server

    Kokhanovsky, Alexander A


    This book details modern methods of the radiative transfer theory. It presents recent advances in light scattering (measurements and theory) and highlights the newest developments in remote sensing of aerosol and cloud properties.

  17. Dark-field light scattering imaging of living cancer cell component from birth through division using bioconjugated gold nanoprobes. (United States)

    Qian, Wei; Huang, Xiaohua; Kang, Bin; El-Sayed, Mostafa A


    Novel methods and technologies that could extend and complement the capabilities of the prevailing fluorescence microscope in following the cell cycle under different perturbations are highly desirable in the area of biological and biomedical imaging. We report a newly designed instrument for long-term light scattering live cell imaging based on integrating a homebuilt environmental cell incubation minichamber and an angled dark-field illumination system into a conventional inverted light microscope. Peptide-conjugated gold nanoparticles that are selectively delivered to either the cytoplasmic or nuclear region of the cell are used as light scattering contrast agents. The new system enables us to carry out continuous and intermittence-free dark-field live cell imaging over several tens of hours. A variety of applications of this imaging system are demonstrated, such as monitoring the nuclear uptake of peptide-conjugated gold nanoparticles, tracking the full cycle of cancer cells from birth to division, following the chromosome dynamics during cell mitosis, and observing the intracellular distribution of gold nanoparticles after cell division. We also discuss the overall effect of nuclear targeting gold nanoparticles on the cell viability of parent and daughter cells.

  18. Broadband Light Absorption and Efficient Charge Separation Using a Light Scattering Layer with Mixed Cavities for High-Performance Perovskite Photovoltaic Cells with Stability. (United States)

    Moon, Byeong Cheul; Park, Jung Hyo; Lee, Dong Ki; Tsvetkov, Nikolai; Ock, Ilwoo; Choi, Kyung Min; Kang, Jeung Ku


    CH3 NH3 PbI3 is one of the promising light sensitizers for perovskite photovoltaic cells, but a thick layer is required to enhance light absorption in the long-wavelength regime ranging from PbI2 absorption edge (500 nm) to its optical band-gap edge (780 nm) in visible light. Meanwhile, the thick perovskite layer suppresses visible-light absorption in the short wavelengths below 500 nm and charge extraction capability of electron-hole pairs produced upon light absorption. Herein, we find that a new light scattering layer with the mixed cavities of sizes in 100 and 200 nm between transparent fluorine-doped tin oxide and mesoporous titanium dioxide electron transport layer enables full absorption of short-wavelength photons (λ cell with a light scattering layer of mixed cavities is stabilized due to suppressed charge accumulation. Consequently, this work provides a new route to realize broadband light harvesting of visible light for high-performance perovskite photovoltaic cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Light scattering by soap films

    NARCIS (Netherlands)

    Vrij, A.

    A theory is constructed describing the scattering from a liquid film (e.g., a soap film) of a light beam polarized normal to the plane of incidence. This scattering is due to the small irregular corrugations caused by thermal motion. The interference of the reflected incident beam with its multiple

  20. Scattering of light by crystals

    CERN Document Server

    Hayes, William


    This authoritative graduate-level text describes inelastic light scattering by crystals and its use in the investigation of solid-state excitation, with experimental techniques common to all types of excitation. 1978 edition.

  1. Confocal light scattering and absorption spectroscopic microscopy (United States)

    Qiu, Le; Vitkin, Edward; Salahuddin, Saira; Zaman, Munir M.; Andersson, Charlotte; Freedman, Steven D.; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.


    We have developed a novel optical method for observing submicron intracellular structures in living cells which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light scattering spectroscopy (LSS). CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales on the order of 100 nm. In addition, it provides not only size information but also information about the biochemical and physical properties of the cell.

  2. Mesoporous inverse opal TiO2 film as light scattering layer for dye-sensitized solar cell. (United States)

    Jin, Mingshi; Kim, Sung Soo; Yoon, Minyoung; Li, Zhenghua; Lee, Yoon Yun; Kim, Ji Man


    The light harvesting efficiency of dye-sensitized solar cells was enhanced by using a scattering layer. Such as sphere type TiO2, inverse photonic crystal TiO2, hollow spherical TiO2. Among these materials, the TiO2 with inverse photonic crystal (IPC) structure, synthesized by self-assembly using spherical templates, has attracted much attention due to their photonic crystal characteristics and light scattering effects. However, when applied in the DSSCs, the surface area of IPC is very low that caused insufficient adsorption amount of dye molecules. In the present work, a scattering layer with mesoporous inverse photonic crystal (MIPC) TiO2 film was fabricated by the sol-gel reactions with surfactant-assisted sol-gel method using poly(methyl methacrylate) as the template and titanium (IV) isopropoxide as the TiO2 precursor. After removing the PMMA and surfactant, a highly ordered macroporous structure with mesopores were successfully obtained. The surface area and total pore volume of the MIPC were 82 m2/g and 0.31 cm3/g, respectively, which is much larger than those of the IPC. The DSSCs with the scattering layer of MIPC film exhibited 18 and 10% higher photo-conversion efficiency than those of cells only with a nano-crystalline TiO2 film and with scattering layer of IPC film. From UV-visible spectra of dye solutions, the MIPC film showed a higher amount of absorbed dye molecules than those of the reference and IPC films. Accordingly, an increase in the photo-current density through abundant adsorption of the dye, coupled with inherent light scattering ability can improve overall photo-conversion efficiency.

  3. Light Scattering in Solid IX

    CERN Document Server

    Cardona, Manuel


    This is the ninth volume of a well-established series in which expert practitioners discuss topical aspects of light scattering in solids. It reviews recent developments concerning mainly semiconductor nanostructures and inelastic x-ray scattering, including both coherent time-domain and spontaneous scattering studies. In the past few years, light scattering has become one of the most important research and characterization methods for studying carbon nanotubes and semiconducting quantum dots, and a crucial tool for exploring the coupled exciton--photon system in semiconductor cavities. Among the novel techniques discussed in this volume are pump--probe ultrafast measurements and those which use synchrotron radiation as light source. The book addresses improvements in the intensity, beam quality and time synchronization of modern synchrotron sources, which made it possible to measure the phonon dispersion in very small samples and to determine electronic energy bands as well as enabling real-time observations...

  4. Enhancement of Raman light scattering in dye-labeled cell membrane on metal-containing conducting polymer film (United States)

    Grushevskaya, H. V.; Krylova, N. G.; Lipnevich, I. V.; Orekhovskaja, T. I.; Egorova, V. P.; Shulitski, B. G.


    An enhanced Raman spectroscopy method based on a plasmon resonance in ultrathin metal-containing LB-film deposited on nanoporous anodic alumina supports has been proposed. This material has been utilized to enhance Raman scattering of light in fluorescent-labeled subcellular membrane structures. It has been shown that the plasmon resonance between vibrational modes of the organometallic complexes monolayers and dye-labeled subcellular structures happens. It makes possible to detect interactions between living cell monolayers and an extracellular matrix.

  5. Scattered light characterization of FORTIS (United States)

    McCandliss, Stephan R.; Carter, Anna; Redwine, Keith; Teste, Stephane; Pelton, Russell; Hagopian, John; Kutyrev, Alexander; Li, Mary J.; Moseley, S. Harvey


    We describe our efforts to build a Wide-Field Lyman alpha Geocoronal simulator (WFLaGs) for characterizing the end-to-end sensitivity of FORTIS (Far-UV Off Rowland-circle Telescope for Imaging and Spectroscopy) to scattered Lyman α emission from outside of the nominal (1/2 degree)2 field-of-view. WFLaGs is a 50 mm diameter F/1 aluminum parabolic collimator fed by a hollow cathode discharge lamp with a 80 mm clear MgF2 window housed in a vacuum skin. It creates emission over a 10 degree FOV. WFLaGS will allow us to validate and refine a recently developed scattered light model and verify our scatter light mitigation strategies, which will incorporate low scatter baffle materials, and possibly 3-d printed light traps, covering exposed scatter centers. We present measurements of scattering intensity of Lyman alpha as a function of angle with respect to the specular reflectance direction for several candidate baffle materials. Initial testing of WFLaGs will be described.

  6. Laser light scattering basic principles and practice

    CERN Document Server

    Chu, Benjamin


    Geared toward upper-level undergraduate and graduate students, this text introduces the interdisciplinary area of laser light scattering, focusing chiefly on theoretical concepts of quasielastic laser scattering.

  7. Fourier transform light scattering angular spectroscopy using digital inline holography. (United States)

    Kim, Kyoohyun; Park, YongKeun


    A simple and practical method for measuring the angle-resolved light scattering (ARLS) from individual objects is reported. Employing the principle of inline holography and a Fourier transform light scattering technique, both the static and dynamic scattering patterns from individual micrometer-sized objects can be effectively and quantitatively obtained. First, the light scattering measurements were performed on individual polystyrene beads, from which the refractive index and diameter of each bead were retrieved. Also, the measurements of the static and dynamic light scattering from intact human red blood cells are demonstrated. Using the present method, an existing microscope can be directly transformed into a precise instrument for ARLS measurements.

  8. Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering (United States)

    Jo, Youngju; Jung, Jaehwang; Lee, Jee Woong; Shin, Della; Park, Hyunjoo; Nam, Ki Tae; Park, Ji-Ho; Park, Yongkeun


    Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from -70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth.

  9. Angle-resolved light scattering of individual rod-shaped bacteria based on Fourier transform light scattering. (United States)

    Jo, YoungJu; Jung, JaeHwang; Lee, Jee Woong; Shin, Della; Park, HyunJoo; Nam, Ki Tae; Park, Ji-Ho; Park, YongKeun


    Two-dimensional angle-resolved light scattering maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform light scattering techniques, the light scattering patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from -70° to 70°. The measured light scattering patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic light scattering. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in light scattering within bacterial species is related to the cellular dry mass and growth.

  10. Light scattering near phase transitions

    CERN Document Server

    Cummins, HZ


    Since the development of the laser in the early 1960's, light scattering has played an increasingly crucial role in the investigation of many types of phase transitions and the published work in this field is now widely dispersed in a large number of books and journals.A comprehensive overview of contemporary theoretical and experimental research in this field is presented here. The reviews are written by authors who have actively contributed to the developments that have taken place in both Eastern and Western countries.

  11. Real-Time Light Scattering Tracking of Gold Nanoparticles- bioconjugated Respiratory Syncytial Virus Infecting HEp-2 Cells (United States)

    Wan, Xiao-Yan; Zheng, Lin-Ling; Gao, Peng-Fei; Yang, Xiao-Xi; Li, Chun-Mei; Li, Yuan Fang; Huang, Cheng Zhi


    Real-time tracking of virus invasion is crucial for understanding viral infection mechanism, which, however, needs simple and efficient labeling chemistry with improved signal-to-noise ratio. For that purpose, herein we investigated the invasion dynamics of respiratory syncytial virus (RSV) through dark-field microscopic imaging (iDFM) technique by using Au nanoparticles (AuNPs) as light scattering labels. RSV, a ubiquitous, non-segmented, pleiomorphic and negative-sense RNA virus, is an important human pathogen in infants, the elderly, and the immunocompromised. In order to label the enveloped virus of paramyxoviridae family, an efficient streptavidin (SA)-biotin binding chemistry was employed, wherein AuNPs and RSV particles modified with SA and biotin, respectively, allowing the AuNP-modified RSVs to maintain their virulence without affecting the native activities of RSV, making the long dynamic visualization successful for the RSV infections into human epidermis larynx carcinoma cells.

  12. The influence of different metal ions on light scattering properties of pattern microbial fuel cells' bacteria Desulfuromonas acetoxidans (United States)

    Vasyliv, Oresta M.; Bilyy, Olexsandr I.; Getman, Vasyl'B.; Ferensovyich, Yaroslav P.; Yaremyk, Roman Y.; Hnatush, Svitlana O.


    Microbial fuel cell (MFC) technologies represent the newest approach for generating electricity - bioelectricity generation from biomass using bacteria. Desulfuromonas acetoxidans are aquatic obligatory anaerobic sulfur-reducing bacteria that possess an ability to produce electric current in the processes of organic matter oxidation and Fe3+- or Mn4+- reduction. These are pattern objects for MFC systems. They could be applied as a highly effective and self-sustaining model of wastewater treatment which contains energy in the form of biodegradable organic matter. But wastewaters contain high concentrations of xenobiotics, such as different heavy metals that have a detrimental effect towards all living organisms. The influence of different concentrations of MnCl2×4H2O, FeSO4 CuSO4, CdSO4, ZnSO4 and PbNO3 on light scattering properties of aquatic D. acetoxidans bacteria on the base of their cells' size distribution and relative content has been investigated by the new method of measurement. The cell distribution curve was in the range of 0.4 - 1.4 μm. The most crucial changes of cell concentration dependences, compared with other investigated metal ions, have been observed under the influence of copper ions. The ability of D. acetoxidans bacteria to produce electric current upon the specific cultivation conditions and the influence of Fe2+ and Mn2+ has been verified.

  13. Scattering theory of stochastic electromagnetic light waves. (United States)

    Wang, Tao; Zhao, Daomu


    We generalize scattering theory to stochastic electromagnetic light waves. It is shown that when a stochastic electromagnetic light wave is scattered from a medium, the properties of the scattered field can be characterized by a 3 x 3 cross-spectral density matrix. An example of scattering of a spatially coherent electromagnetic light wave from a deterministic medium is discussed. Some interesting phenomena emerge, including the changes of the spectral degree of coherence and of the spectral degree of polarization of the scattered field.

  14. ATLAS Event Display: Light-by-Light Scattering

    CERN Multimedia

    ATLAS Collaboration


    An event display of light-by-light scattering in ultra-peripheral lead+lead collisions at 5.02 TeV with the ATLAS detector at the LHC. The event 461251458 from run 287931 recorded on 13 December 2015 at 09:51:07 is shown. Two back-to-back photons with an invariant mass of 24 GeV with no additional activity in the detector are presented. All calorimeter cells with E>500 MeV are shown.

  15. Low-cost high-haze films based on ZnO nanorods for light scattering in thin c-Si solar cells (United States)

    Strano, V.; Smecca, E.; Depauw, V.; Trompoukis, C.; Alberti, A.; Reitano, R.; Crupi, I.; Gordon, I.; Mirabella, S.


    Light scattering from ZnO nanorods (NR) is investigated, modeled, and applied to a solar cell. ZnO NR (120-1300 nm long, 280-60 nm large), grown by low-cost chemical bath deposition at 90 °C, exhibit diffused-to-total transmitted light as high as 70% and 30% in the 400 and 1000 nm wavelength range, respectively. Data and scattering simulation show that ZnO NR length plays a crucial role in light diffusion effect. A transparent ZnO NR film grown on glass and placed on top of a 1 μm thick c-Si solar cell is shown to enhance the light-current conversion efficiency for wavelengths longer than 600 nm.

  16. Study of erythrocyte membrane fluctuation using light scattering analysis (United States)

    Lee, Hoyoon; Lee, Sangyun; Park, YongKeun; Shin, Sehyun


    It is commonly known that alteration of erythrocyte deformability lead to serious microcirculatory diseases such as retinopathy, nephropathy, etc. Various methods and technologies have been developed to diagnose such membrane properties of erythrocytes. In this study, we developed an innovative method to measure hemorheological characteristics of the erythrocyte membrane using a light scattering analysis with simplified optic setting and multi-cell analysis as well. Light scattering intensity through multiple erythrocytes and its power density spectrum were obtained. The results of light scattering analyses were compared in healthy control and artificially hardened sample which was treated with glutaraldehyde. These results were further compared with conventional assays to measure deformable property in hemorheology. We found that light scattering information would reflect the disturbance of membrane fluctuation in artificially damaged erythrocytes. Therefore, measuring fluctuation of erythrocyte membrane using light scattering signal could facilitate simple and precise diagnose of pathological state on erythrocyte as well as related complications.

  17. Stimulated Raman scattering excited by incoherent light in plasma

    Directory of Open Access Journals (Sweden)

    Yao Zhao


    Full Text Available Stimulated Raman scattering (SRS excited by incoherent light is studied via particle-in-cell simulations. It is shown that a large bandwidth of incoherent light can reduce the growth of SRS and electron heating considerably in the linear stage. However, different components of the incoherent light can be coupled by the Langmuir waves, so that stimulated Raman backward scattering can develop. When the bandwidth of incoherent light is larger than the Langmuir wave frequency, forward SRS can be seeded between different components of the incoherent light. The incoherent light can only increase the time duration for nonlinear saturation but cannot diminish the saturation level obviously.

  18. The Amsterdam-Granada Light Scattering Database

    NARCIS (Netherlands)

    Muñoz, O.; Moreno, F.; Guirado, D.; Dabrowska, D.D.; Volten, H.; Hovenier, J.W.


    The Amsterdam Light Scattering Database proved to be a very successful way of promoting the use of the data obtained with the Amsterdam Light Scattering apparatus at optical wavelengths. Many different research groups around the world made use of the experimental data. After the closing down of the

  19. Scattering of light and other electromagnetic radiation

    CERN Document Server

    Kerker, Milton


    The Scattering of Light and Other Electromagnetic Radiation discusses the theory of electromagnetic scattering and describes some practical applications. The book reviews electromagnetic waves, optics, the interrelationships of main physical quantities and the physical concepts of optics, including Maxwell's equations, polarization, geometrical optics, interference, and diffraction. The text explains the Rayleigh2 theory of scattering by small dielectric spheres, the Bessel functions, and the Legendre functions. The author also explains how the scattering functions for a homogenous sphere chan

  20. Loading and testing a light scattering cell with a binary fluid mixture near its critical composition (United States)

    Jacobs, Donald T.; Becker, James S.


    Critical phenomena has been the subject of physics research for many years. However, only in recent years has the research effort become intense. The current intensity has caused the study of critical phenomena to be grouped into a previous older era and a present contemporary era. Turbidity cell filling with methanol cyclohexane is one of the first steps toward a further understanding of critical phenomena. Work performed during the research period is outlined. During this period, research was spent developing apparatus and techniques that will make it possible to study critical phenomena through turbidity measurements on methanol cyclohexane. Topics covered range from the orientation of turbidity cell parts for assembly to the filling apparatus and procedure used when th cell is built. The last section will briefly cover some of the observations made when viewing the cell in a controlled water bath. However, before mention is made of the specifics of the summer research, a short introduction to critical phenomena and turbidity and how they relate to this experiment is provided.

  1. Light scattering in ophthalmic research (United States)

    Tuchin, Valery V.


    In the overview optical models of cornea, sclera, and crystalline lens humor will be presented. On the basis of these models eye tissue transmittance spectra and scattering indicatrices for the main informative elements of the mueller matrix will be analyzed. This paper will discuss some problems of eye tissue optical characteristics control, and possibilities and perspectives of elastic scattering spectroscopy in cataract diagnostics.

  2. Detection of Silver Nanoparticles in Cells by Flow Cytometry Using Light Scattering and Far-red Fluorescence (United States)

    The cellular uptake of different sized silver nanoparticles (l0 nm, 50 nm, and 75nm) coated with polyvinylpyrrolidone (PVP) or citrate in ARPE-19 cells following 24 hour incubation was detected by side scatter through the use of a flow cytometer. A large far red fluorescence sign...

  3. Fluctuations in doubly scattered laser light

    NARCIS (Netherlands)

    Rijswijk, F.C. van; Smith, U.L.


    Fluctuations in laser light, doubly scattered by brownian particles, were analysed by measuring the spectral noise power of the photodetector current. Scattering took place at two spatially separated systems of spherical particles. Analytic expressions for the field and intensity correlations are

  4. The Amsterdam-Granada Light Scattering Database (United States)

    Muñoz, O.; Moreno, F.; Guirado, D.; Dabrowska, D. D.; Volten, H.; Hovenier, J. W.


    The Amsterdam Light Scattering Database proved to be a very successful way of promoting the use of the data obtained with the Amsterdam Light Scattering apparatus at optical wavelengths. Many different research groups around the world made use of the experimental data. After the closing down of the Dutch scattering apparatus, a modernized and improved descendant, the IAA Cosmic Dust Laboratory (CoDuLab), has been constructed at the Instituto de Astrofísica de Andalucía (IAA) in Granada, Spain. The first results of this instrument for water droplets and for two samples of clay particles have been published. We would now like to make these data also available to the community in digital form by introducing a new light scattering database, the Amsterdam-Granada Light Scattering Database ( By combining the data from the two instruments in one database we ensure the continued availability of the old data, and we prevent fragmentation of important data over different databases. In this paper we present the Amsterdam-Granada Light Scattering Database.

  5. Ultrasonic trap for light scattering measurement (United States)

    Barton, Petr; Pavlu, Jiri


    Light scattering is complex phenomenon occurring widely in space environments, including the dense dusty clouds, nebulas or even the upper atmosphere of the Earth. However, when the size of the dust (or of other scattering center) is close to the incident light wavelength, theoretical determination is difficult. In such case, Mie theory is to be used but there is a lack of the material constants for most space-related materials. For experimental measurement of light scattering, we designed unique apparatus, based on ultrasonic trap. Using acoustic levitation we are able to capture the dust grain in midair, irradiate it with laser, and observe scattering directly with goniometer-mounted photodiode. Advantage of this approach is ability to measure directly in the air (thus, no need for the carrier medium) and possibility to study non-spherical particles. Since the trap development is nearly finished and initial experiments are carried out, the paper presents first tests on water droplets.

  6. Effect of large TiO2 Nanoparticles as Light Scatter in Matrix of Small Nanoparticles to Improve the Efficiency in Dye- Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    M. Hamadanian


    Full Text Available In this study, we investigated the effect of using large TiO2 nanoparticles in the matrix of small nanoparticles to improve the performance of dye-sensitized solar cells (DSSCs, as light scatter to increase the light harvesting. The mixed powder was deposited by electrophoretic deposition (EPD on FTO (F-SnO2 coated glass. It is shown that adding small quantity of larger nanoparticles can enhance the performance of DSSCs. This paper also studies the deferential scanning calorimetry (DSC of mixed powders to detect the phase transitions, due to the change of weight percentage between large and small nanoparticles.

  7. Application of orthogonal light scattering for routine screening of lymphocyte samples

    NARCIS (Netherlands)

    Terstappen, Leonardus Wendelinus Mathias Marie; de Grooth, B.G.; van Berkel, W.; ten Napel, C.H.H.; Greve, Jan


    Orthogonal and forward light-scattering properties of lymphocytes were measured from patients with different lymphocytic diseases in order to determine the potential value of light scattering as a screening device. Monitoring of orthogonal light scattering of lymphocytes of a B-cell chronic

  8. Spatial quantum correlations in multiple scattered light

    NARCIS (Netherlands)

    Lodahl, P.; Mosk, Allard; Lagendijk, Aart


    We predict a new spatial quantum correlation in light propagating through a multiple scattering random medium. The correlation depends on the quantum state of the light illuminating the medium, is infinite in range, and dominates over classical mesoscopic intensity correlations. The spatial quantum

  9. The Whiteness of Things and Light Scattering (United States)

    Gratton, L. M.; Lopez-Arias, T.; Calza, G.; Oss, S.


    We discuss some simple experiments dealing with intriguing properties of light and its interaction with matter. In particular, we show how to emphasize that light reflection, refraction and scattering can provide a proper, physical description of human perception of the "colour" white. These experiments can be used in the classroom with an enquiry…

  10. Nanometer-scale sizing accuracy of particle suspensions on an unmodified cell phone using elastic light scattering.

    Directory of Open Access Journals (Sweden)

    Zachary J Smith

    Full Text Available We report on the construction of a Fourier plane imaging system attached to a cell phone. By illuminating particle suspensions with a collimated beam from an inexpensive diode laser, angularly resolved scattering patterns are imaged by the phone's camera. Analyzing these patterns with Mie theory results in predictions of size distributions of the particles in suspension. Despite using consumer grade electronics, we extracted size distributions of sphere suspensions with better than 20 nm accuracy in determining the mean size. We also show results from milk, yeast, and blood cells. Performing these measurements on a portable device presents opportunities for field-testing of food quality, process monitoring, and medical diagnosis.

  11. Nanometer-scale sizing accuracy of particle suspensions on an unmodified cell phone using elastic light scattering. (United States)

    Smith, Zachary J; Chu, Kaiqin; Wachsmann-Hogiu, Sebastian


    We report on the construction of a Fourier plane imaging system attached to a cell phone. By illuminating particle suspensions with a collimated beam from an inexpensive diode laser, angularly resolved scattering patterns are imaged by the phone's camera. Analyzing these patterns with Mie theory results in predictions of size distributions of the particles in suspension. Despite using consumer grade electronics, we extracted size distributions of sphere suspensions with better than 20 nm accuracy in determining the mean size. We also show results from milk, yeast, and blood cells. Performing these measurements on a portable device presents opportunities for field-testing of food quality, process monitoring, and medical diagnosis.

  12. Enhanced Efficiency in Dye-Sensitized Solar Cells by Electron Transport and Light Scattering on Freestanding TiO2 Nanotube Arrays

    Directory of Open Access Journals (Sweden)

    Won-Yeop Rho


    Full Text Available Dye-sensitized solar cells (DSSCs were fabricated with closed- or open-ended freestanding TiO2 nanotube arrays as photoelectrodes that were decorated with carbon materials and large TiO2 nanoparticles (NPs to enhance energy conversion efficiency. The energy conversion efficiency of DSSCs based on open-ended freestanding TiO2 nanotube arrays increased from 4.47% to 5.39%, compared to the DSSCs based on closed-ended freestanding TiO2 nanotube arrays. In DSSCs based on the open-ended freestanding TiO2 nanotube arrays, the energy conversion efficiency with carbon materials increased from 5.39% to 6.19% due to better electron transport, and that with a scattering layer from 5.39% to 6.24% due to more light harvesting compared to the DSSCs without carbon materials or scattering layer. Moreover, the energy conversion efficiency of DSSCs based on the open-ended freestanding TiO2 nanotube arrays with both carbon materials and scattering layer increased from 5.39% to 6.98%, which is an enhancement of 29.50%. In DSSCs based on the TiO2 nanotube arrays, the carbon materials can improve electron transport by π-π conjugation, and the large TiO2 NPs can enhance the capacity to light-harvest by scattering.

  13. Early detection of precancer using Polarized Light Scattering Spectroscopy (United States)

    Gurjar, Rajan; Backman, Vadim; Itzkan, Irving; Dasari, Ramachandra; Perelman, Lev; Feld, Michael; Badizadegan, Kamran


    We have developed a light scattering technique to detect early pre-cancerous changes in the tissues which, line the epithelial surfaces of the body. The majority of cancers are epithelial in nature. We use light reflection spectroscopy to observe the earliest sign, the enlargement of the index of the cells which, line this layer. Our method is based on the feature that single scattering in the backward direction retains the polarization of the light incident on nucleus in the epithelial layer whereas multiple scattering destroys the polarization. Collecting the backscattering spectral intensities of both polarizations, and taking their difference, we extract the single scattering component. The signals are analyzed to extract the nuclear density, size and the relative refractive index. The experimental results will be presented to illustrate the physical basis of the technique, and its biological application.

  14. Light scattering instrumentation for micro gravity research (United States)

    Wyatt, Philip J.


    The analysis of light scattered from an ensemble of particles has long been a preferred method for characterizing their physical properties. Instrumentation to perform the measurements which forms the basis for such analysis is available in many forms based upon a variety of different experimental techniques. A system is presented which is singularly applicable for making many types of measurements in a microgravity environment. The commercial version of this device, the DAWN-F, has been used in many labs throughout the world to perform analyses of particular importance for both research and production. Light scattering theory is reviewed and the structure and function of the system is described.

  15. Higher moments of scattered light fields by heterodyne analysis (United States)

    Harris, M.; Paerson, G. N.; Hill, C. A.; Vaughan, J. M.


    A simple scattering experiment employing heterodyne detection and operating in Gaussian scattering regime (with large number of illuminated independent scatterers) is shown to yield experimental values of higher-order moments of scattered light intensity distribution in agreement with theoretical predictions. This permits assessment of Gaussian behavior. Laser light scattering from a rotating glass screen is used in the study.

  16. High-Energy Compton Scattering Light Sources

    CERN Document Server

    Hartemann, Fred V; Barty, C; Crane, John; Gibson, David J; Hartouni, E P; Tremaine, Aaron M


    No monochromatic, high-brightness, tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray sources include: nuclear resonance fluorescence spectroscopy, time-resolved positron annihilation spectroscopy, and MeV flash radiography. The peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale with the electron beam brightness and the drive laser pulse energy. This gamma 2

  17. Light Scattering Tools for Cosmic Dust Modeling (United States)

    Il'in, V. B.; Voshchinnikov, N. V.; Farafonov, V. G.; Henning, Th.; Perelman, A. Ya.

    Because cosmic dust grains vary significantly in both morphology and chemical composition, it is necessary to develop different light scattering tools to analyze their scattering properties and to reconcile these properties with observations. We present a set of recently developed tools which includes a database of optical constants of materials of astronomical interest, exact and approximate methods and numerical codes using various models of a non-spherical inhomogeneous scatterer, a database of optical properties of non-spherical particles, a new approach to find a solution of ill-posed inverse problems in optics, and an original polarized radiation-transfer code applicable to 3D media populated by aligned non-spherical scatterers.

  18. Light-like scattering in quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bjerrum-Bohr, N.E.J. [Niels Bohr International Academy & Discovery Center, Niels Bohr Institute,University of Copenhagen, Blegdamsvej 17, Copenhagen Ø, DK-2100 (Denmark); Donoghue, John F. [Department of Physics-LGRT, University of Massachusetts,Amherst, MA, 01003 (United States); Holstein, Barry R. [Department of Physics-LGRT, University of Massachusetts,Amherst, MA, 01003 (United States); Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA, 93016 (United States); Planté, Ludovic; Vanhove, Pierre [CEA, DSM, Institut de Physique Théorique, IPhT, CNRS MPPU, URA2306,Saclay, Gif-sur-Yvette, F-91191 (France)


    We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin-(1/2), spin-1) from an external massive scalar field, such as the Sun or a black hole. This is achieved by treating general relativity as an effective field theory and identifying the non-analytic pieces of the one-loop gravitational scattering amplitude. It is emphasized throughout the paper how modern amplitude techniques, involving spinor-helicity variables, unitarity, and squaring relations in gravity enable much simplified computations. We directly verify, as predicted by general relativity, that all classical effects in our computation are universal (in the context of matter type and statistics). Using an eikonal procedure we confirm the post-Newtonian general relativity correction for light-like bending around large stellar objects. We also comment on treating effects from quantum ℏ dependent terms using the same eikonal method.

  19. Dynamic light scattering study of microemulsion (United States)

    Sharifi, Soheil; Alavi, Alireza


    Brownian motion is a subject of renewed interest since the development of photon correlation spectroscopy (PCS) in the last decade. The dynamic properties of microemulsions and colloidal systems are studied by measuring the relaxation of concentration fluctuations. The mixture of C12E5nanoemulsion with PEG have been studied by small-angle X-ray scattering and dynamic light scattering in order to determine structure and dynamic of the system. Light scattering experiment shown an exponential relaxation for pure C12E5 nanoemulsion that the shape of the relaxation change with increasing of polymer concentration in the C12E5 nanoemulsion, that relaxation becomes non-exponential, which demonstrates increase of cooperatively in the C12E5 nanoemulsion.

  20. Light Scattering based detection of food pathogens (United States)

    The current methods for detecting foodborne pathogens are mostly destructive (i.e., samples need to be pretreated), and require time, personnel, and laboratories for analyses. Optical methods including light scattering based techniques have gained a lot of attention recently due to its their rapid a...

  1. Protoplanetary disks and exoplanets in scattered light

    NARCIS (Netherlands)

    Stolker, T.


    High-contrast imaging facilitates the direct detection of protoplanetary disks in scattered light and self-luminous exoplanets on long-period orbits. The combined power of extreme adaptive optics and differential imaging techniques delivers high spatial resolution images of disk morphologies down to

  2. Aerosol light-scattering in the Netherlands

    NARCIS (Netherlands)

    Brink, H.M. ten; Veefkind, J.P.; Waijers-IJpelaan, A.; Hage, J.C. van der


    The relation between the (midday) aerosol light-scattering and the concentrations of nitrate and sulfate has been assessed at a site near the coast of the North Sea in The Netherlands. Midday was selected for the measurements because this is the time at which the aerosol is most effective in the

  3. Quasi-Elastic Light Scattering in Ophthalmology (United States)

    Ansari, Rafat R.

    The eye is not just a "window to the soul"; it can also be a "window to the human body." The eye is built like a camera. Light which travels from the cornea to the retina traverses through tissues that are representative of nearly every tissue type and fluid type in the human body. Therefore, it is possible to diagnose ocular and systemic diseases through the eye. Quasi-elastic light scattering (QELS) also known as dynamic light scattering (DLS) is a laboratory technique routinely used in the characterization of macromolecular dispersions. QELS instrumentation has now become more compact, sensitive, flexible, and easy to use. These developments have made QELS/DLS an important tool in ophthalmic research where disease can be detected early and noninvasively before the clinical symptoms appear.

  4. Solvothermal Synthesis of Hierarchical TiO2Microstructures with High Crystallinity and Superior Light Scattering for High-Performance Dye-Sensitized Solar Cells. (United States)

    Li, Zhao-Qian; Mo, Li-E; Chen, Wang-Chao; Shi, Xiao-Qiang; Wang, Ning; Hu, Lin-Hua; Hayat, Tasawar; Alsaedi, Ahmed; Dai, Song-Yuan


    In this article, hierarchical TiO 2 microstructures (HM-TiO 2 ) were synthesized by a simple solvothermal method adopting tetra-n-butyl titanate as the titanium source in a mixed solvent composed of N,N-dimethylformamide and acetic acid. Due to the high crystallinity and superior light-scattering ability, the resultant HM-TiO 2 are advantageous as photoanodes for dye-sensitized solar cells. When assembled to the entire photovoltaic device with C101 dye as a sensitizer, the pure HM-TiO 2 -based solar cells showed an ultrahigh photovoltage up to 0.853 V. Finally, by employing the as-obtained HM-TiO 2 as the scattering layer and optimizing the architecture of dye-sensitized solar cells, both higher photovoltage and incident photon-to-electron conversion efficiency value were harvested with respect to TiO 2 nanoparticles-based dye-sensitized solar cells, resulting in a high power conversion efficiency of 9.79%. This work provides a promising strategy to develop photoanode materials with outstanding photoelectric conversion performance.

  5. Probing colloidal particle aggregation by light scattering. (United States)

    Trefalt, Gregor; Szilagyi, Istvan; Oncsik, Tamas; Sadeghpour, Amin; Borkovec, Michal


    The present article reviews recent progress in the measurement of aggregation rates in colloidal suspensions by light scattering. Time-resolved light scattering offers the possibility to measure absolute aggregation rate constants for homoaggregation as well as heteroaggregation processes. We further discuss the typical concentration dependencies of the aggregation rate constants on additives. Addition of simple salts containing monovalent counterions leads to screening of the electrostatic repulsion of the charged particles and a transition from slow to rapid aggregation. Addition of salts containing multivalent counterions may lead to a charge reversal, which results in a sequence of two instability regions. Heteroaggregation rates between oppositely charged particles decrease with increasing salt level. This decrease is caused by screening of the electrostatic attraction between these particles.

  6. Laser Light Scattering by Shock Waves (United States)

    Panda, J.; Adamovsky, G.


    Scattering of coherent light as it propagates parallel to a shock wave, formed in front of a bluff cylindrical body placed in a supersonic stream, is studied experimentally and numerically. Two incident optical fields are considered. First, a large diameter collimated beam is allowed to pass through the shock containing flow. The light intensity distribution in the resultant shadowgraph image, measured by a low light CCD camera, shows well-defined fringes upstream and downstream of the shadow cast by the shock. In the second situation, a narrow laser beam is brought to a grazing incidence on the shock and the scattered light, which appears as a diverging sheet from the point of interaction, is visualized and measured on a screen placed normal to the laser path. Experiments are conducted on shocks formed at various free-stream Mach numbers, M, and total pressures, P(sub 0). It is found that the widths of the shock shadows in a shadowgraph image become independent of M and P(sub 0) when plotted against the jump in the refractive index, (Delta)n, created across the shock. The total scattered light measured from the narrow laser beam and shock interaction also follows the same trend. In the numerical part of the study, the shock is assumed to be a 'phase object', which introduces phase difference between the upstream and downstream propagating parts of the light disturbances. For a given shape and (Delta)n of the bow shock the phase and amplitude modulations are first calculated by ray tracing. The wave front is then propagated to the screen using the Fresnet diffraction equation. The calculated intensity distribution, for both of the incident optical fields, shows good agreement with the experimental data.

  7. Light scattering measurement of sodium polyacrylate products (United States)

    Lama, Nisha; Norwood, David; Boone, Steven; Massie-Boyer, Valerie


    In the presentation, we will describe the use of a multi-detector HPLC incorporating the DAWN EOS multi-angle laser light scattering (MALLS) detector to measure the properties such as molecular weight, RMS radius, contour and persistence length and polydispersity of sodium polyacrylate products. The samples of sodium polyacrylate are used in various industries as thickening agents, coating dispersants, artificial snow, laundry detergent and disposable diapers. Data and results obtained from the experiment will be presented.

  8. Theory of diffusive light scattering cancellation cloaking

    CERN Document Server

    Farhat, Mohamed; Guenneau, Sebastien; Bagci, Hakan; Salama, Khaled Nabil; Alu, Andrea


    We report on a new concept of cloaking objects in diffusive light regime using the paradigm of the scattering cancellation and mantle cloaking techniques. We show numerically that an object can be made completely invisible to diffusive photon density waves, by tailoring the diffusivity constant of the spherical shell enclosing the object. This means that photons' flow outside the object and the cloak made of these spherical shells behaves as if the object were not present. Diffusive light invisibility may open new vistas in hiding hot spots in infrared thermography or tissue imaging.

  9. Color stimuli perception in presence of light scattering


    OZONLINSH, Maris; Ikaunieks, Gatis; Karitans, Varis; Colomb, Michèle


    Perception of different color contrast stimuli was studied in the presence of light scattering: in a fog chamber in Clermont-Ferrand and in laboratory conditions where light scattering of similar levels was obtained, using different light scattering eye occluders. Blue (shortest wavelength) light is scattered in fog to the greatest extent, causing deterioration of vision quality especially for the monochromatic blue stimuli.However, for the color stimuli presented on a white backgrou...

  10. Light scattering of thin azobenzene side-chain polyester layers

    DEFF Research Database (Denmark)

    Kerekes, Á.; Lörincz, E.; Ramanujam, P.S.


    Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering characteris...... for the domain size in thin liquid crystalline polyester layers being responsible for the dominant light scattering. The characteristic domain Sizes obtained from the Fourier transformation of polarization microscopic Pictures confirm these values.......Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering...... characteristics than the liquid crystalline polyester. The amorphous samples have negligible polarization part orthogonal to the incident beam. the liquid crystalline samples have relative high orthogonal polarization part in light scattering, The light scattering results can be used to give a lower limit...

  11. The role of cellular environment in dynamic light scattering (United States)

    An, Ran; Jeong, Kwan; Turek, John; Nolte, David


    We have developed motility contrast imaging (MCI) as a coherence-domain volumetric imaging approach that uses subcellular dynamics as an endogenous imaging contrast agent of living tissue. Fluctuation spectroscopy analysis of dynamic light scattering (DLS) from 3-D tissue has identified functional frequency bands related to organelle transport, membrane undulations and cell shape change. In this paper, we track the behavior of dynamic light scattering as we bridge the gap between the two extremes of 2-D cell culture on the one hand, and 3-D tissue spheroids on the other. In a light backscattering geometry, we capture speckle from 2-D cell culture consisting of isolated cells or planar rafts of cells on cell-culture surfaces. DLS from that cell culture shows differences and lower sensitivity to intra-cellular dynamics compared with the 3-D tissue. The motility contrast is weak in this limit. As the cellular density increases to cover the surface, the motility contrast increases. As environmental perturbations or pharmaceuticals are applied, the fluctuation spectral response becomes more dramatic as the dimensionality of the cellular aggregations increases. We show that changing optical thickness of the cellular-to-tissue targets usually causes characteristic frequency shifts in the spectrograms, while changing cellular dimensionality causes characteristic frequencies to be enhanced or suppressed.

  12. Looking for Dust-Scattering Light Echoes (United States)

    Mills, Brianna; Heinz, Sebastian; Corrales, Lia


    Galactic X-ray transient sources such as neutron stars or black holes sometimes undergo an outburst in X-rays. Ring structures have been observed around three such sources, produced by the X-ray photons being scattered by interstellar dust grains along our line of sight. These dust-scattering light echoes have proven to be a useful tool for measuring and constraining Galactic distances, mapping the dust structure of the Milky Way, and determining the dust composition in the clouds producing the echo. Detectable light echoes require a sufficient quantity of dust along our line of sight, as well as bright, short-lived Galactic X-ray flares. Using data from the Monitor of All-Sky X-ray Image (MAXI) on-board the International Space Station, we ran a peak finding algorithm in Python to look for characteristic flare events. Each flare was characterized by its fluence, the integrated flux of the flare over time. We measured the distribution of flare fluences to show how many observably bright flares were recorded by MAXI. This work provides a parent set for dust echo searches in archival X-ray data and will inform observing strategies with current and future X-ray missions such as Athena and Lynx.

  13. Light scattering by microorganisms in the open ocean (United States)

    Stramski, Dariusz; Kiefer, Dale A.

    Recent enumeration and identification of marine particles that are less than 2μm in diameter, suggests that they may be the major source of light scattering in the open ocean. The living components of these small particles include viruses, heterotrophic and photoautotrophic bacteria and the smallest eucaryotic cells. In order to examine the relative contribution by these (and other) microorganisms to scattering, we have calculated a budget for both the total scattering and backscattering coefficients (at 550nm) of suspended particles. This budget is determined by calculating the product of the numerical concentration of particles of a given category and the scattering cross-section of that category. Values for this product are then compared to values for the particulate scattering coefficients predicted by the models of GORDON and MOREL (1983) and MOREL (1988). In order to make such a comparison, we have estimated both the total scattering and backscattering cross-section of various microbial components that include viruses, heterotrophic bacteria, prochlorophytes, cyanobacteria, ultrananoplankton (2-8μm), larger nanoplankton (8-20μm) and microplankton (>20 μm). Such determinations are based upon Mie scattering calculations and measurements of the cell size distribution and the absorption and scattering coefficients of microbial cultures. In addition, we have gathered published information on the numerical concentration of living and detrial marine particles in the size range from 0.03 to 100μm. The results of such a study are summarized as follows. The size distribution of microorganisms in the ocean roughly obeys an inverse 4th power law over three orders of magnitude in cell diameter, from 0.2 to 100μm. Thus, the size distribution of living organisms is similar to that for total particulate matter as determined by electronic particle counters. For representative values of refractive index, it appears that most of the scattering in the sea comes from

  14. Fourier-transform light scattering of individual colloidal clusters. (United States)

    Yu, HyeonSeung; Park, HyunJoo; Kim, Youngchan; Kim, Mahn Won; Park, YongKeun


    We present measurements of the scalar-field light scattering of individual dimer, trimer, and tetrahedron shapes among colloidal clusters. By measuring the electric field with quantitative phase imaging at the sample plane and then numerically propagating to the far-field scattering plane, the two-dimensional light-scattering patterns from individual colloidal clusters are effectively and precisely retrieved. The measured scattering patterns are consistent with simulated patterns calculated from the generalized multiparticle Mie solution.

  15. Factors affecting intraocular light scattering from different color straylight sources (United States)

    Ikaunieks, Gatis; Ozolinsh, Maris


    Important optical parameter of the eye is intraocular light scattering. Straylight can reduce visual acuity, contrast sensitivity. It is one of the main factors for glare, especially for drivers at night, when there is light source some distance away from the fixation point. There are many factors, which can affect amount of light scattering in the eye. To assess the effect of the color of the straylight source on retinal image quality at different light scattering levels, retinal straylight was measured with and without light scattering occluder. Red, green and blue colors were choosed for straylight source. Psychophysical and electrophysiological methods were used to evaluate light scattering effect on perception on different color stimuli. Results show that straylight values are the greatest for blue color with and without light scattering occluder. In measurements without light scattering occluder ratio of straylight values for red and green color are different between subjects. Using light scattering occluder straylight values for green color are greater than for red color. Optical and anatomical factors which can induce these spectral variations are discussed. Psychophysical and electrophysiological methods showed the similar changes in results with straylight values when light scattering were increased.

  16. Modeling fluorescent light distributions in scattering media (United States)

    Phillips, Kevin G.; Jacques, Steven L.


    It is hoped that the non-invasive optical characterization of physiological features of normal and diseased epithelia can be assessed through the fluorescent emission of such tissues. With a high percentage of cancers arising in the epithelium, the characterization of carcinogenesis in such tissues is imperative. Fluorescent emission from the epithelium, e.g. oral mucosa, has been shown to be sensitive to physiological features, such as cellular morphology, and the amount and types of biochemical agents present in the tissue. Efforts to distinguish the spectral signatures of diseased and healthy states of tissues from fluorescence have been confounded by the distortion of the intrinsic fluorescent signature as a result of wavelength dependent absorption and scattering within the tissue. Theoretical models of light propagation in biological media are required for understanding the distortion of the intrinsic fluorescence arising from compromised tissues. In this work we model the distortion of the intrinsic fluorescence emitted from a tissue with wavelength dependent optical properties, arising from varying blood and water content, using the radiative transport equation. As an example, we demonstrate the ability of blood and water content to distort the signal of a white light source as it is embedded deeper into a tissue.

  17. Fundamentals of ophthalmic diagnostical methods based on laser light scattering (United States)

    Tuchin, Valery V.; Maksimova, Irina L.; Kochubey, Vyacheslav I.; Semyonova, Tatjana N.; Tatarintsev, Sergey N.; Babkova, N. L.


    The basic principles of light scattering methods which should be very useful for ophthalmic disease diagnostics and monitoring are discussed. As an example a human eye lens tissue was considered. Angular-dependent scattering spectra and scattering matrix elements M12, M33, M34 and M44 are suggested as informative parameters for eye lens aging and cataract monitoring.

  18. Measuring the dynamics of structural changes in biological macromolecules from light scattering data (United States)

    Johnson, Adriel D.


    Examining techniques to study the dynamics of structural changes in various molecules has been an ongoing goal of the space program. Knowing how these phenomena occur in biological systems is fundamental to understanding what is necessary for life to remain functional in the space environment. A hierarchy of biological organization is functionally described when cells join together small organic molecules to form larger and more complex molecules. Characterizing the architecture of a particular macromolecule helps determine how that molecule works in the living cell and is basic to the diversity of life. Understanding this arrangement involves the correlation of the structure of macromolecules with their functions. A light scattering photometer was developed for detecting continuous measurement of the angular spectrum of light scattered by dynamically changing systems. The analysis of light scattered by biological macromolecules can be used to determine concentration, size, shape, molecular weight, and structural changes of cells, such as erythrocytes. Some light scattering photometers can collect and store 120 angular scattering spectra per minute, with an angular resolution of 0.2 deg which can be displayed with computer graphics. The light scattering photometer does the following: functions to produce and detect scattered light; determines scatter angles; and collects, stores, and analyzes data.

  19. Light scattering studies on solutions containing calcium phosphates

    NARCIS (Netherlands)

    Feenstra, T.P.; Bruyn, P.L. de

    A number of light scattering experiments was performed on calcium and phosphate containing solutions at pH 8.33 and 26°C. Supplementary information was obtained by means of dynamic light scattering, scanning electron microscopy, and transmission electron microscopy. The measurements prove that

  20. Light Scattering and Current Enhancement for Microcrystalline Silicon Thin-Film Solar Cells on Aluminium-Induced Texture Glass Superstrates with Double Texture

    Directory of Open Access Journals (Sweden)

    Yunfeng Yin


    Full Text Available Microcrystalline silicon (μc-Si:H thin-film solar cells are processed on glass superstrates having both micro- and nanoscale surface textures. The microscale texture is realised at the glass surface, using the aluminium-induced texturing (AIT method, which is an industrially feasible process enabling a wide range of surface feature sizes (i.e., 700 nm–3 μm of the textured glass. The nanoscale texture is made by conventional acid etching of the sputter-deposited transparent conductive oxide (TCO. The influence of the resulting “double texture” on the optical scattering is investigated by means of atomic force microscopy (AFM (studying the surface topology, haze measurements (studying scattering into air, and short-circuit current enhancement measurements (studying scattering into silicon. A predicted enhanced optical scattering efficiency is experimentally proven by a short-circuit current enhancement ΔIsc of up to 1.6 mA/cm2 (7.7% relative increase compared to solar cells fabricated on a standard superstrate, that is, planar glass covered with nanotextured TCO. Enhancing the autocorrelation length (or feature size of the AIT superstrates might have the large potential to improve the μc-Si:H thin-film solar cell efficiency, by reducing the shunting probability of the device while maintaining a high optical scattering performance.

  1. Positron Production in Multiphoton Light-by-Light Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Koffas, Thomas


    We present the results of an experimental study on e{sup +}e{sup -} pair production during the collision of a low emittance 46.6 GeV electron beam with terawatt laser pulses from a Nd:glass laser at 527 nm wavelength and with linear polarization. The experiment was conducted at the Final Focus Test Beam facility in the Stanford Linear Accelerator Center. Results with a 49.1 GeV electron beam are also included. A signal of 106 {+-} 14 positrons for the 46.6 GeV electron beam case and of 22 {+-} 10 positrons for the 49.1 GcV case above background, has been detected. We interpret the positrons as the products of a two-step process during which laser photons are backscattered to high energy gamma photons that absorb in their turn several laser photons in order to produce a e{sup +}e{sup -} pair. The data compare well with the existing theoretical models. This is the first observation in the laboratory of inelastic Light-by-Light scattering with only real photons. Alternatively, the data are interpreted as a manifestation of the spontaneous breakdown of the vacuum under the influence of an intense external alternating electric field.

  2. Evaluation of aggregate stability of Haplic Stagnosols using dynamic light scattering, phase analysis light scattering and color coordinates

    Czech Academy of Sciences Publication Activity Database

    Artemyeva, Z.; Žigová, Anna; Kirillova, N.; Šťastný, Martin; Holubík, O.; Podrázký, V.


    Roč. 63, č. 13 (2017), s. 1838-1851 ISSN 0365-0340 Institutional support: RVO:67985831 Keywords : land use * aggregate stability * organo- clay complexes * dynamic light scattering * phase analysis light scattering * color coordinates Subject RIV: DF - Soil Science Impact factor: 2.137, year: 2016

  3. Absorption and scattering of light by small particles

    CERN Document Server

    Bohren, Craig F


    Absorption and Scattering of Light by Small Particles. Treating absorption and scattering in equal measure, this self-contained, interdisciplinary study examines and illustrates how small particles absorb and scatter light. The authors emphasize that any discussion of the optical behavior of small particles is inseparable from a full understanding of the optical behavior of the parent material-bulk matter. To divorce one concept from the other is to render any study on scattering theory seriously incomplete. Special features and important topics covered in this book include:. * Classical theor

  4. Light scattering by nonspherical particles theory, measurements, and applications

    CERN Document Server

    Mishchenko, Michael I; Travis, Larry D


    There is hardly a field of science or engineering that does not have some interest in light scattering by small particles. For example, this subject is important to climatology because the energy budget for the Earth's atmosphere is strongly affected by scattering of solar radiation by cloud and aerosol particles, and the whole discipline of remote sensing relies largely on analyzing the parameters of radiation scattered by aerosols, clouds, and precipitation. The scattering of light by spherical particles can be easily computed using the conventional Mie theory. However, most small solid part

  5. Scattering light interference from liquid crystal polymer dispersion films (United States)

    Huang, Chi-Yen; Tsai, Ming-Shann; Lin, Chi-Huang; Fuh, Andy Y.


    The Quetelet-type ring pattern is observed in liquid crystal polymer dispersion (LCPD) films. The clusters of the polymer network and liquid crystal (LC) domains with different director axes in the LCPD films serve as scatterers. Cells with unidirectional and multidirectional rubbins are fabricated. Experimental results show that the polarization of incident light, the applied voltage and the ambient temperature significantly affect the ring intensities. However, the contribution of the LC domains is not evident until the voltage is applied. Finally, rubbing the cells in multiple directions reveals that measurement of the Quetelet-type ring intensity can be used to readily identify the orientation of the liquid crystals. This finding also reveals that the LCs in an LCPD mixture are aligned closer to the final rubbing direction than are pure LCs in a multidirectional rubbed cell. A simple model was proposed to explain the observations.

  6. Investigation of the effect of scattering agent and scattering albedo on modulated light propagation in water. (United States)

    Mullen, Linda; Alley, Derek; Cochenour, Brandon


    A recent paper described experiments completed to study the effect of scattering on the propagation of modulated light in laboratory tank water [Appl. Opt.48, 2607 (2009)APOPAI0003-693510.1364/AO.48.002607]. Those measurements were limited to a specific scattering agent (Maalox antacid) with a fixed scattering albedo (0.95). The purpose of this paper is to study the effects of different scattering agents and scattering albedos on modulated light propagation in water. The results show that the scattering albedo affects the number of attenuation lengths that the modulated optical signal propagates without distortion, while the type of scattering agent affects the degree to which the modulation is distorted with increasing attenuation length. © 2011 Optical Society of America

  7. Monte Carlo, small angle light scattering, and dynamic light scattering studies of dilute polymer solutions (United States)

    McNamara, Joseph E.

    The adsorption of negatively charged polymer, negative/neutral block copolymer and a polyampholyte to patterned surfaces is investigated using off-lattice Monte Carlo simulations. The surface is decorated by stripe and checkerboard patterns of mixed charges. The polymer has periodic charge segments, which potentially match the periodicity of the surface pattern. Results show that the chain entropy of a flexible polymer disrupts and prevents full pattern recognition. Quantities such as average adsorption energy and the radii of gyration of the adsorbed polymer are calculated and found to be dictated by the size of the surface pattern and its correlation to the polymer charge density. We performed small angle light scattering on dilute-solution-grown polyethylene crystals grown from quenches in para-xylene. The quench depths ranged from 60 to 85°C for 0.05 wt.% and 0.1 wt.% linear-low-polydispersity polyethylenes. We found asymmetric scattering patterns for the lower temperature quenches to 65°C, and symmetric scattering patterns for the higher temperature quenches to 80°C. There is a smooth transition from asymmetric to symmetric scattering as we change the quench depth. The correlation lengths d=2pi/qmax corresponding to the peaks of intensity versus q ranged from 15 to 30 mum. We find evidence that these length scales correspond to assemblies of single polyethylene crystals. Also, we have performed dynamic light scattering on solutions of sodium-poly(styrene-sulfonate) (NaPSS) and poly(ethylene-oxide) (PEO) in water with BaCl2. The fast mode ( Dfast) and slow mode (Dslow) diffusion coefficients were measured as a function of polymer concentration for both polymers in dilute solution. We found that the diffusion coefficients remained relatively constant in the concentration regimes investigated and Dfast and Dslow for both polymers differed by about 1½ orders of magnitude: 1.1 x 10-6 cm2/s versus 7.8 x 10-8 cm2/s for NaPSS and 6.7 x 10-7 cm2/s versus 4.2 x 10

  8. Light scattering by particles in water theoretical and experimental foundations

    CERN Document Server

    Jonasz, Miroslaw


    Light scattering-based methods are used to characterize small particles suspended in water in a wide range of disciplines ranging from oceanography, through medicine, to industry. The scope and accuracy of these methods steadily increases with the progress in light scattering research. This book focuses on the theoretical and experimental foundations of the study and modeling of light scattering by particles in water and critically evaluates the key constraints of light scattering models. It begins with a brief review of the relevant theoretical fundamentals of the interaction of light with condensed matter, followed by an extended discussion of the basic optical properties of pure water and seawater and the physical principles that explain them. The book continues with a discussion of key optical features of the pure water/seawater and the most common components of natural waters. In order to clarify and put in focus some of the basic physical principles and most important features of the experimental data o...

  9. Light scattering by magnons in whispering gallery mode cavities (United States)

    Sharma, Sanchar; Blanter, Yaroslav M.; Bauer, Gerrit E. W.


    Brillouin light scattering is an established technique to study magnons, the elementary excitations of a magnet. Its efficiency can be enhanced by cavities that concentrate the light intensity. Here, we theoretically study inelastic scattering of photons by a magnetic sphere that supports optical whispering gallery modes in a plane normal to the magnetization. Magnons with low angular momenta scatter the light in the forward direction with a pronounced asymmetry in the Stokes and the anti-Stokes scattering strength, consistent with earlier studies. Magnons with large angular momenta constitute Damon-Eschbach modes which are shown to inelastically reflect light. The reflection spectrum contains either a Stokes or anti-Stokes peak, depending on the direction of the magnetization, a selection rule that can be explained by the chirality of the Damon-Eshbach magnons. The controllable energy transfer can be used to manage the thermodynamics of the magnet by light.

  10. Scattering of Sculpted Light in Intact Brain Tissue, with implications for Optogenetics (United States)

    Favre-Bulle, Itia A.; Preece, Daryl; Nieminen, Timo A.; Heap, Lucy A.; Scott, Ethan K.; Rubinsztein-Dunlop, Halina


    Optogenetics uses light to control and observe the activity of neurons, often using a focused laser beam. As brain tissue is a scattering medium, beams are distorted and spread with propagation through neural tissue, and the beam’s degradation has important implications in optogenetic experiments. To address this, we present an analysis of scattering and loss of intensity of focused laser beams at different depths within the brains of zebrafish larvae. Our experimental set-up uses a 488 nm laser and a spatial light modulator to focus a diffraction-limited spot of light within the brain. We use a combination of experimental measurements of back-scattered light in live larvae and computational modelling of the scattering to determine the spatial distribution of light. Modelling is performed using the Monte Carlo method, supported by generalised Lorenz-Mie theory in the single-scattering approximation. Scattering in areas rich in cell bodies is compared to that of regions of neuropil to identify the distinct and dramatic contributions that cell nuclei make to scattering. We demonstrate the feasibility of illuminating individual neurons, even in nucleus-rich areas, at depths beyond 100 μm using a spatial light modulator in combination with a standard laser and microscope optics.

  11. Light Scattering by Optically Soft Particles Theory and Applications

    CERN Document Server

    Sharma, Subodh K


    The present monograph deals with a particular class of approximation methods in the context of light scattering by small particles. This class of approximations has been termed as eikonal or soft particle approximations. The eikonal approximation was studied extensively in the potential scattering and then adopted in optical scattering problems. In this context, the eikonal and other soft particle approximations pertain to scatterers whose relative refractive index compared to surrounding medium is close to unity. The study of these approximations is very important because soft particles occur abundantly in nature. For example, the particles that occur in ocean optics, biomedical optics, atmospheric optics and in many industrial applications can be classified as soft particles. This book was written in recognition of the long-standing and current interest in the field of scattering approximations for soft particles. It should prove to be a useful addition for researchers in the field of light scattering.

  12. Novel Quantum Effects in Light Scattering from Cold Trapped Atoms (United States)

    Orlowski, A.; Gajda, M.; Krekora, P.; Glauber, R. J.; Mostowski, J.

    Both far off-resonance and resonant scattering of light from single atoms trapped by 3D harmonic potentials has thoroughly been studied. Novel effects are predicted for different physical regimes. We have shown that dynamics of the atomic center-of-mass strongly influences the scattering cross section. Possibility of using spectrum of the scattered light in far-off-resonance regime to nondestructively measure the temperature of ultracold atoms is advocated: off-resonance scattering can be used as an `optical thermometer'. The realistic Compton-like regime in resonant scattering has been investigated in detail. Another interesting quantum effect in resonant regime, which has not been discussed here due to the lack of space, is the time resolved scattering, showing up when the atom can remain in the excited state long enough to make many trips back and forth in the trap before emitting a photon. The possibility of the experimental observation of the predicted effects is now being scrutinized.

  13. Interactive directional subsurface scattering and transport of emergent light

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Frisvad, Jeppe Revall; Mosegaard, Jesper


    need to store elements of irradiance from specific directions. To include changes in subsurface scattering due to changes in the direction of the incident light, we instead sample incident radiance and store scattered radiosity. This enables us to accommodate not only the common distance......-based analytical models for subsurface scattering but also directional models. In addition, our method enables easy extraction of virtual point lights for transporting emergent light to the rest of the scene. Our method requires neither preprocessing nor texture parameterization of the translucent objects....... To build our maps of scattered radiosity, we progressively render the model from different directions using an importance sampling pattern based on the optical properties of the material. We obtain interactive frame rates, our subsurface scattering results are close to ground truth, and our technique...

  14. Characterization of Platelet Concentrates Using Dynamic Light Scattering

    National Research Council Canada - National Science Library

    Labrie, Audrey; Marshall, Andrea; Bedi, Harjot; Maurer-Spurej, Elisabeth


    .... ThromboLUX is a non-invasive, optical test utilizing dynamic light scattering to characterize a platelet sample by the relative quantity of platelets, microparticles, and other particles present in the sample...

  15. Light scattering from polymer solutions and nanoparticle dispersions

    CERN Document Server

    Schärtl, Wolfgang; Janca, Josef


    Light scattering is a very powerful method to characterize the structure of polymers and nanoparticles in solution. Recent technical developments have strongly enhanced the possible applications of this technique, overcoming previous limitations like sample turbidity or insufficient experimental time scales. However, despite their importance, these new developments have not yet been presented in a comprehensive form. In addition, and maybe even more important to the broad audience, there lacks a simple-to-read textbook for students and non-experts interested in the basic principles and fundamental techniques of light scattering. As part of the Springer Laboratory series, this book tries not only to provide such a simple-to-read and illustrative textbook about the seemingly very complicated topic of light scattering from polymers and nanoparticles in dilute solution, but also intends to cover some of the newest technical developments in experimental light scattering.

  16. Angular resolved light scattering microscopy on human chromosomes (United States)

    Müller, Dennis; Stark, Julian; Kienle, Alwin


    Angular resolved scattering light measurements on chromosomes are compared to Discrete Dipole Approximation (DDA) simulations using Atomic Force Microscopy (AFM) based geometrical models. This could present a novel, marker-free method for human chromosome karyotyping.

  17. Synthesis and nonlinear light scattering of microemulsions and nanoparticle suspensions (United States)

    Salazar-Alvarez, German; Björkman, Eva; Lopes, Cesar; Eriksson, Anders; Svensson, Sören; Muhammed, Mamoun


    Microemulsions composed of normal or inverse micellar solutions and aqueous suspensions of pristine (uncoated) or silica-coated iron oxide nanoparticles, mainly γ-Fe2O3, were synthesised and their optical limiting properties investigated. The microemulsions are colorless solutions with high transparency for visible wavelengths while the aqueous suspensions of iron oxide are of pale yellow colour. Optical limiting experiments performed in 2 mm cells using a f/5 optical system with a frequency doubled Nd:YAG laser delivering 5 ns pulses with 10 Hz repetition rate, showed clamping levels of ˜3 μJ for the suspensions of both pristine and silica-coated iron oxide nanoparticles. A strong photoinduced nonlinear light scattering was observed for the water-in-oil microemulsion and the aqueous suspensions of nanoparticles while oil-in-water microemulsions did not show a significant nonlinear effect. Measurements carried out using an integrating sphere further verified that the photoinduced nonlinear light scattering is the dominating nonlinear mechanism while the nonlinear absorption of iron oxide nanoparticles is negligible at 532 nm.

  18. Synthesis of aerogel tiles with high light scattering length

    CERN Document Server

    Danilyuk, A F; Okunev, A G; Onuchin, A P; Shaurman, S A


    The possibility of aerogel tiles production for RICH detectors is described. Monolithic blocks of silica aerogel were synthesized by two-step sol-gel processing of tetraethoxysilane Si(OEt) sub 4 followed by high temperature supercritical drying with organic solvent. The important characteristic of aerogel is the light scattering length. In the wide range of refraction indexes the light scattering length exceeds 4 cm at 400 nm.

  19. Scaling in light scattering by sharp conical metal tips

    CERN Document Server

    Pors, Anders; Bozhevolnyi, Sergey I


    Using the electrostatic approximation, we analyze electromagnetic fields scattered by sharp conical metal tips, which are illuminated with light polarized along the tip axis. We establish scaling relations for the scattered field amplitude and phase, whose validity is verified with numerical simulations. Analytic expressions for the wavelength, at which the scattered field near the tip changes its direction, and field decay near the tip extremity are obtained, relating these characteristics to the cone angle and metal permittivity. The results obtained have important implications to various tip-enhanced phenomena, ranging from Raman and scattering near-field imaging to photoemission spectroscopy and nano-optical trapping.

  20. Polarized light scattering as a probe for changes in chromosome structure

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Daniel Benjamin [Univ. of California, Berkeley, CA (United States)


    Measurements and calculations of polarized light scattering are applied to chromosomes. Calculations of the Mueller matrix, which completely describes how the polarization state of light is altered upon scattering, are developed for helical structures related to that of chromosomes. Measurements of the Mueller matrix are presented for octopus sperm heads, and dinoflagellates. Comparisons of theory and experiment are made. A working theory of polarized light scattering from helices is developed. The use of the first Born approximation vs the coupled dipole approximation are investigated. A comparison of continuous, calculated in this work, and discrete models is also discussed. By comparing light scattering measurements with theoretical predictions the average orientation of DNA in an octopus sperm head is determined. Calculations are made for the Mueller matrix of DNA plectonemic helices at UV, visible and X-ray wavelengths. Finally evidence is presented that the chromosomes of dinoflagellates are responsible for observed differential scattering of circularly-polarized light. This differential scattering is found to vary in a manner that is possibly correlated to the cell cycle of the dinoflagellates. It is concluded that by properly choosing the wavelength probe polarized light scattering can provide a useful tool to study chromosome structure.

  1. Application of light scattering to coatings a user's guide

    CERN Document Server

    Diebold, Michael P


    The book begins with the fundamentals of light scattering, first by individual particles, then by small groups of particles, and finally by the trillions of particles present in a real-life paint film. From there, Dr. Diebold focuses on application of these fundamentals to paint formulation. The scope includes both theory and practice with an emphasis on application (from both performance and cost standpoints). The book gives a clear understanding of light scattering principles and application of these principles to paint formulation (with a focus on TiO2 - the strongest scattering material a

  2. Scattering of light from the liquid scintillator used in SNO+ (United States)

    Major, Timothy


    SNO+ is a double-beta decay experiment currently under construction in Sudbury, Ontario. It will contain approximately a kiloton of liquid scintillator loaded with a neodymium isotope that it is thought may undergo neutrinoless double-beta decay. To simulate events and to interpret data, it is important to understand how light scatters in the liquid scintillator, including the angular distribution of scattered photons. This talk will highlight the status of SNO+ and discuss a measurement of the distribution of scattered light from a sample of liquid scintillator.


    Gotterer, Gerald S.; Thompson, Thomas E.; Lehninger, Albert L.


    Angular light-scattering studies have been carried out on suspensions of isolated rat liver mitochondria. The angular scatter pattern has a large forward component, typical of large particles. Changes in dissymmetry and in the intensity of light scattered at 90° have been correlated with changes in optical density during the course of mitochondrial swelling and contraction. Such changes can be measured at mitochondrial concentrations much below those required for optical density measurements. Changes in mitochondrial geometry caused by factors "leaking" from mitochondria, not detectable by optical density measurements, have been demonstrated by measuring changes in dissymmetry. Angular light-scattering measurements therefore offer the advantages of increased sensitivity and of added indices of changes in mitochondrial conformation. PMID:19866589

  4. Characterization of light scattering in translucent ceramics (United States)

    Illarramendi, M. A.; Aramburu, I.; Fernandez, J.; Balda, R.; Williams, S. N.; Adegoke, J. A.; Noginov, M. A.


    We have obtained expressions for the reflectance and transmittance of a scattering medium with weak absorption in terms of a diffusion model, where the source is an incoming beam, whose intensity exponentially decays along the propagation path. We have applied three experimental techniques, one of which is based on the developed model, to determine the transport mean-free-path in translucent samples of Nd:YAG ceramics.

  5. Quantum noise frequency correlations of multiply scattered light

    DEFF Research Database (Denmark)

    Lodahl, Peter


    Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....

  6. Optical memory effect from polarized Laguerre-Gaussian light beam in light-scattering turbid media (United States)

    Shumyatsky, Pavel; Milione, Giovanni; Alfano, Robert R.


    Propagation effects of polarized Laguerre-Gaussian light with different orbital angular momentum (L) in turbid media are described. The optical memory effect in scattering media consisting of small and large size (compared to the wavelength) scatterers is investigated for scattered polarized light. Imaging using polarized laser modes with a varying orbital strength L-parameter was performed. The backscattered image quality (contrast) was enhanced by more than an order of magnitude using circularly polarized light when the concentration of scatterers was close to invisibility of the object.

  7. Light Scattering by Surface Tension Waves. (United States)

    Weisbuch, G.; Garbay, F.


    This simple and inexpensive experiment is an illustration of the physical concepts of interaction between light and surface tension waves, and provides a new method of measuring surface tension. (Author/GA)

  8. Electrical generation of stationary light in random scattering media (United States)

    Redmond, S. M.; Armstrong, G. L.; Chan, H.-Y.; Mattson, E.; Mock, A.; Li, B.; Potts, J. R.; Cui, M.; Rand, S. C.; Oliveira, S. L.; Marchal, J.; Hinklin, T.; Laine, R. M.


    In recent years there has been great interest in controlling the speed of propagation of electromagnetic waves. In gases and crystals, coherent techniques have been applied to alter the speed of light without changing the physical or chemical structure of the medium. Also, light transmitted by highly disordered solids has exhibited signatures of Anderson localization, indicating the existence of a regime of ``stopped'' light that is mediated by random elastic scattering. However, to date, light has not been generated in a random medium as a pointlike excitation that is fixed in space from the outset. Here we report experimental evidence for the electrical generation and confinement of light within nanosized volumes of a random dielectric scattering medium in which a population inversion has been established, and discuss the properties of these novel light sources.

  9. Using light scattering to determine the stoichiometry of protein complexes. (United States)

    Mogridge, Jeremy


    The stoichiometry of a protein complex can be calculated from an accurate measurement of the complex's molecular weight. Multiangle laser light scattering in combination with size exclusion chromatography and interferometric refractometry provides a powerful means for determining the molecular weights of proteins and protein complexes. In contrast to conventional size exclusion chromatography and analytical centrifugation, measurements do not rely on the use of molecular weight standards and are not affected by the shape of the proteins. The technique is based on the direct relationship between the amount of light scattered by a protein in solution, and the product of its concentration and molecular weight. A typical experimental configuration includes a size exclusion column to fractionate the sample, a light scattering detector to measure scattered light, and an interferometric refractometer to measure protein concentration. The determination of the molecular weight of an anthrax toxin complex will be used to illustrate how multiangle laser light scattering can be used to determine the stoichiometry of protein complexes.

  10. Investigation of ferrofluid nanostructure by laser light scattering: medical applications (United States)

    Nepomnyashchaya, E. K.; Velichko, E. N.; Pleshakov, I. V.; Aksenov, E. T.; Savchenko, E. A.


    Investigation of ferrofluids nanostructure by the laser light scattering technique is presented. Experimental studies involved measurements of the intensity of the laser radiation scattered by ferrofluid particles in interaction with albumin and under the influence of magnetic field. The effects of the magnitude and duration of the applied magnetic field on the formation of aggregates of magnetic nanoparticles and also the influence of magnetic fluids of different concentrations on blood proteins are considered. The findings may be useful for medical applications.

  11. An experimental study of light scattering by large, irregular particles (United States)

    Mcguire, Audrey F.; Hapke, Bruce W.


    The intensity and polarization of light scattered by a variety of types of artificial partices large compared to the wavelength were measured as a function of phase angle. Shape, surface roughness, absorption coefficient, and internal scattering coefficient were varied systematically and their effects studied. Scattering by clear, smooth-surfaced spheres is in quantitative agreement with the predictions of the geometrical optics (ray theory) approximation to physical optics (Mie theory). The phase functions of almost all of the particles measured have both forward and backward scattering lobes. A two-parameter, double Henyey-Greenstein function generally provides reasonably good descriptions of the data, while keeping the number of free parameters to the minimum necessary. On a double Henyey- Greenstein parameter plot all of the particles fall into an L-shaped area of restricted size in which the location is characteristic of the particle type. Formalisms based on the equivalent slab model are also given for estimating the scattering efficiency of a large, irregular particle. For most dielectric particles the transmitted, forward scattered light is partially negatively polarized. It is this component that is respopnsible for the well-known maximum in the polarization curves of planetary regoliths at phase angles around 100 deg. For phase angles between about 30 deg and 70 deg the internally scattered light is found to be randomly polarized in the particles studied here, so that the only contribution to the second component of the Stokes vector is by Fresnel reflection from the particle surface. If this empirical result is general, measurement of the second Stokes vector of the light scattered from a regolith at these angles may provide a method of remotely measuring the mean refractive index.

  12. Multiple Scattering of Light in Superdiffusive Media (United States)

    Bertolotti, Jacopo; Vynck, Kevin; Wiersma, Diederik S.


    Light transport in superdiffusive media of finite size is studied theoretically. The intensity Green’s function for a slab geometry is found by discretizing the fractional diffusion equation and employing the eigenfunction expansion method. Truncated step length distributions and complex boundary conditions are considered. The profile of a coherent backscattering cone is calculated in the superdiffusion approximation.

  13. Resonance light scattering determination of metallothioneins using levofloxacin-palladium complex as a light scattering probe (United States)

    Xue, Jin-Hua; Qian, Qiu-Mei; Wang, Yong-Sheng; Meng, Xia-Ling; Liu, Lu


    A novel method of resonance light scattering (RLS) was developed for the analysis of trace metallothioneins (MTs) in human urine. In a CH3COOH-CH3COONa buffer solution of pH 4.5, the formation of a complex between levofloxacin (LEV)-Pd and MTs led to enhance the RLS intensity of the system, and the enhanced RLS intensity at 468 nm was proportional to the concentration of MTs in the range of 0.059-22.4 μg mL-1. The linear regression equation was ΔI = 127.5 ρ (μg mL-1)-88.02 with a correlation coefficient of 0.9992, and the detection limit of 17.8 ng mL-1. The relative standard deviation and the average recovery were 3.8-5.4% (n = 11) and 92.15%, respectively. The proposed method is convenient, reliable and sensitive, and has been used successfully for the determination of trace MTs in human urine samples.

  14. Single particle analysis with a 360/sup 0/ light scattering photometer

    Energy Technology Data Exchange (ETDEWEB)

    Bartholdi, M.F.


    Light scattering by single spherical homogeneous particles in the diameter range 1 to 20 and relative refractive index 1.20 is measured. Particle size of narrowly dispersed populations is determined and a multi-modal dispersion of five components is completely analyzed. A 360/sup 0/ light scattering photometer for analysis of single particles has been designed and developed. A fluid stream containing single particles intersects a focused laser beam at the primary focal point of an ellipsoidal reflector ring. The light scattered at angles theta = 2.5/sup 0/ to 177.5/sup 0/ at phi = 0/sup 0/ and 180/sup 0/ is reflected onto a circular array of photodiodes. The ellipsoidal reflector is situated in a chamber filled with fluid matching that of the stream to minimize refracting and reflecting interfaces. The detector array consists of 60 photodiodes each subtending 3/sup 0/ in scattering angle on 6/sup 0/ centers around 360/sup 0/. 32 measurements on individual particles can be acquired at rates of 500 particles per second. The intensity and angular distribution of light scattered by spherical particles are indicative of size and relative refractive index. Calculations, using Lorenz--Mie theory, of differential scattering patterns integrated over angle corresponding to the detector geometry determined the instrument response to particle size. From this the expected resolution and experimental procedures are determined.Ultimately, the photometer will be utilized for identification and discrimination of biological cells based on the sensitivity of light scattering to size, shape, refractive index differences, internal granularity, and other internal morphology. This study has demonstrated the utility of the photometer and indicates potential for application to light scattering studies of biological cells.

  15. Color stimuli perception in presence of light scattering. (United States)

    Ozolinsh, Maris; Colomb, Michéle; Ikaunieks, Gatis; Karitans, Varis


    Perception of different color contrast stimuli was studied in the presence of light scattering: in a fog chamber in Clermont-Ferrand and in laboratory conditions where light scattering of similar levels was obtained, using different light scattering eye occluders. Blue (shortest wavelength) light is scattered in fog to the greatest extent, causing deterioration of vision quality especially for the monochromatic blue stimuli. However, for the color stimuli presented on a white background, visual acuity in fog for blue Landolt-C optotypes was higher than for red and green optotypes on the white background. The luminance of color Landolt-C optotypes presented on a LCD screen was chosen corresponding to the blue, green, and red color contributions in achromatic white stimuli (computer digital R, G, or B values for chromatic stimuli equal to RGB values in the achromatic white background) that results in the greatest luminance contrast for the white-blue stimuli, thus advancing the visual acuity for the white-blue stimuli. Besides such blue stimuli on the white background are displayed with a uniform, spatially unmodulated distribution of the screen blue phosphor emission over the entire area of the screen including the stimulus C optotype area. It follows that scattering, which has the greatest effect on the blue component of screen luminance, has the least effect on the perception of white-blue stimuli.

  16. T-matrix based inverse light scattering analysis using angle resolved low coherence interferometry (United States)

    Giacomelli, Michael; Chalut, Kevin; Ostrander, Julie; Wax, Adam


    Inverse light scattering methods have been applied by several groups as a means to probe cellular structure in both clinical and scientific applications with sub-wavelength accuracy. These methods determine the geometric properties of tissue scatterers based on far field scattering patterns. Generally, structure is determined by measuring scattering over some range of angles, wavelengths, or polarizations and then fitting the observed data to a database of simulated scattering selected from a range of probable geometries. We have developed new light scattering software based on the T-matrix method that creates databases of scattering from spheroidal objects, representing a substantial improvement over Mie theory, a method limited to simulating scattering from spheres. The computational cost of the T-matrix method is addressed through a simple but massively parallel program that concurrently simulates scattering across hundreds of PCs. We are exploring the use of these T-matrix databases in inverting interferometric measurements of angle-resolved scattering from spheroidal cell nuclei using a technique called angle-resolved low coherence interferometry (a/LCI). With a/LCI, we have previously distinguished between healthy and dysplastic tissue in both cell cultures and in ex vivo rat and hamster tissue using Mie theory to measure nuclear diameter. We now present nuclear volume and spheroidal aspect ratio measurements of unstained, living MCF7 cells using the improved T-matrix database to analyze a/LCI data. We achieve measurement accuracy equivalent to conventional image analysis of stained samples. We will further validate the approach by comparing experimental measurements of scattering from polystyrene microspheroids, and show that the T-matrix is a suitable replacement for Mie theory in ex vivo tissue samples.

  17. Compton scattering of twisted light: Angular distribution and polarization of scattered photons (United States)

    Stock, S.; Surzhykov, A.; Fritzsche, S.; Seipt, D.


    Compton scattering of twisted photons is investigated within a nonrelativistic framework using first-order perturbation theory. We formulate the problem in the density-matrix theory, which enables one to gain new insights into scattering processes of twisted particles by exploiting the symmetries of the system. In particular, we analyze how the angular distribution and polarization of the scattered photons are affected by the parameters of the initial beam such as the opening angle and the projection of orbital angular momentum. We present analytical and numerical results for the angular distribution and the polarization of Compton scattered photons for initially twisted light and compare them with the standard case of plane-wave light.

  18. An empirical correction for moderate multiple scattering in super-heterodyne light scattering (United States)

    Botin, Denis; Mapa, Ludmila Marotta; Schweinfurth, Holger; Sieber, Bastian; Wittenberg, Christopher; Palberg, Thomas


    Frequency domain super-heterodyne laser light scattering is utilized in a low angle integral measurement configuration to determine flow and diffusion in charged sphere suspensions showing moderate to strong multiple scattering. We introduce an empirical correction to subtract the multiple scattering background and isolate the singly scattered light. We demonstrate the excellent feasibility of this simple approach for turbid suspensions of transmittance T ≥ 0.4. We study the particle concentration dependence of the electro-kinetic mobility in low salt aqueous suspension over an extended concentration regime and observe a maximum at intermediate concentrations. We further use our scheme for measurements of the self-diffusion coefficients in the fluid samples in the absence or presence of shear, as well as in polycrystalline samples during crystallization and coarsening. We discuss the scope and limits of our approach as well as possible future applications.

  19. Dynamic light scattering with applications to chemistry, biology, and physics

    CERN Document Server

    Berne, Bruce J


    Lasers play an increasingly important role in a variety of detection techniques, making inelastic light scattering a tool of growing value in the investigation of dynamic and structural problems in chemistry, biology, and physics. Until the initial publication of this work, however, no monograph treated the principles behind current developments in the field.This volume presents a comprehensive introduction to the principles underlying laser light scattering, focusing on the time dependence of fluctuations in fluid systems; it also serves as an introduction to the theory of time correlation f

  20. Dynamic Light Scattering Signal Conditioning for Data Processing (United States)

    Rei, Silviu; Chicea, Dan; Ilie, Beriliu; Olaru, Sorin


    When performing data acquisition for a Dynamic Light Scattering experiment, one of the most important aspect is the filtering and conditioning of the electrical signal. The signal is amplified first and then fed as input for the analog digital convertor. As a result a digital time series is obtained. The frequency spectrum is computed by the logical unit offering the basis for further Dynamic Light Scattering analysis methods. This paper presents a simple setup that can accomplish the signal conditioning and conversion to a digital time series.

  1. Inelastic light scattering in low dimensional semiconductors

    CERN Document Server

    Watt, M


    frequencies of the surface phonon peaks showed good agreement with calculated frequencies based on vibrations in small, geometrically-regular crystals. The main contribution of this work is the study of the surface phonons of the GaAs quantum cylinders. This is the first time that surface phonons have been observed in small fabricated samples: all previous work has involved specially-prepared crystalline powders or else comparatively large slab geometries. The conclusion that can be drawn from this work is that the cylinders are not only well-defined (as observed from the SEM micrographs) but they are also crystalline. The implication is that such structures can now be fabricated at a sufficiently high level to allow progress in prototype devices such as the quantum dot laser. Raman scattering is a powerful technique with which to study the lattice vibrations of semiconductors. Investigations of the phonons of GalnAs-InP heterostructures have shown that although the phonons in GalnAs quantum wells resembled t...

  2. Noninvasive monitoring of the thermal stress in RPE using light scattering spectroscopy (United States)

    Schule, Georg; Huie, Philip; Vankov, Alexander B.; Vitkin, Edward; Fang, Hui; Hanlon, Eugene B.; Perelman, Lev T.; Palanker, Daniel V.


    Introduction: Light Scattering Spectroscopy has been a recently developed as a non-invasive technique capable of sizing the cellular organelles. With this technique, we monitor the heat-induced sub-cellular structural transformations in a human RPE cell culture. Material and Methods: A single layer of human RPE cells (ATCC) was grown on a glass slide. Cells are illuminated with light from a fiber-coupled broadband tungsten lamp. The backscattered (180 degree) light spectra are measured with an optical multichannel analyzer (OMA). Spectra are measured during heating of the sample. Results: We reconstructed the size distribution of sub-micron organelles in the RPE cells and observed temperature-related changes in the scattering density of the organelles in the 200-300nm range (which might be peroxisomes, microsomes or lysosomes). The sizes of the organelles did not vary with temperature, so the change in scattering is most probably due to the change in the refractive indexes. As opposed to strong spectral variation with temperature, the total intensity of the backscattered light did not significantly change in the temperature range of 32-49 °C. Conclusion: We demonstrate that Light Scattering Spectroscopy is a powerful tool for monitoring the temperature-induced sub-cellular transformations. This technique providing an insight into the temperature-induced cellular processes and can play an important role in quantitative assessment of the laser-induced thermal effects during retinal laser treatments, such as Transpupillary Thermal Therapy (TTT), photocoagulation, and Photodynamic Therapy (PDT).

  3. How to distinguish scattered and absorbed light from re-emitted light for white LEDs?

    NARCIS (Netherlands)

    Meretska, Maryna; Lagendijk, Aart; Thyrrestrup Nielsen, Henri; Mosk, Allard; IJzerman, Wilbert; Vos, Willem L.


    We have studied the light transport through phosphor diffuser plates that are used in commercial solid-state lighting modules (Fortimo). These polymer plates contain YAG:Ce+3 phosphor particles that scatter, absorb and re-emit incident light in the visible wavelength range (400-700 nm). To

  4. Engineering of light confinement in strongly scattering disordered media


    Riboli, F; Caselli, N; Vignolini, S; Intonti, F; Vynck, K; Barthelemy, VMP Veronique; Gerardino, A; Balet, LP Laurent; Li, L Ligui = Lianhe; Fiore, A Andrea; Gurioli, M; Wiersma, DS


    Disordered photonic materials can di use and localize light through random multiple scattering, o ering opportunities to study mesoscopic phenomena, control light–matter interactions, and provide new strategies for photonic applications. Light transport in such media is governed by photonic modes characterized by resonances with finite spectral width and spatial extent. Considerable steps have been made recently towards control over the transport using wavefront shaping techniques. The select...

  5. Dynamic light scattering study of peanut agglutinin: Size, shape and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 31; Issue 5. Dynamic light scattering study of peanut agglutinin: Size, shape and urea denaturation ... Peanut agglutinin (PNA) is a homotetrameric protein with a unique open quaternary structure. PNA shows non-two state profile in chaotrope induced denaturation. It passes ...

  6. Quasi-elastic laser light scattering study of polyacrylamide hydrogel ...

    Indian Academy of Sciences (India)

    Polyacrylamide (PAAm) hydrogels immersed in water and aqueous NaCl solutions were investigated for their structure and dynamics using static and quasi-elastic laser light scattering (QELS) techniques. Ensemble-averaged electric field correlation function (, ) obtained from the non-ergodic analysis of ...

  7. HeNe-laser light scattering by human dental enamel

    NARCIS (Netherlands)

    Zijp, [No Value; tenBosch, JJ; Groenhuis, RAJ


    Knowledge of the optical properties of tooth enamel and an understanding of the origin of these properties are necessary for the development of new optical methods for caries diagnosis and the measurement of tooth color. We measured the scattering intensity functions for HeNe-laser light of 80- to

  8. Light scattering of PMMA latex particles in benzene: structural effects

    NARCIS (Netherlands)

    Nieuwenhuis, E.A.; Vrij, A.


    Intra- and interparticle structural effects were studied in polymethylmethacrylate (PMMA) latex dispersions in a nonpolar solvent with the technique of light scattering. The required transparency of the dispersions was attained by a close matching of the refractive index of PMMA and solvent, for

  9. Quantum correlations induced by multiple scattering of quadrature squeezed light

    DEFF Research Database (Denmark)

    Lodahl, Peter


    Propagating quadrature squeezed light through a multiple scattering random medium is found to induce pronounced spatial quantum correlations that have no classical analogue. The correlations are revealed in the number of photons transported through the sample that can be measured from the intensity...


    Indian Academy of Sciences (India)

    an exceptionally clear crystal of gypsum have been able to reproduce a photograph showing the six components with the main line of unaltered. * In his valedictory lecture to the Central College Physical Society on the 25th of. February 1938, Sir C. V. Raman remarked that the study of light scattering in crystals should yield ...

  11. Using Light Scattering to Track, Characterize and Manipulate Colloids

    NARCIS (Netherlands)

    van Oostrum, P.D.J.|info:eu-repo/dai/nl/304829897


    A new technique is developed to analyze in-line Digital Holographic Microscopy images, making it possible to characterize, and track colloidal particles in three dimensions at unprecedented accuracy. We took digital snapshots of the interference pattern between the light scattered by micrometer

  12. Parasitic light scattered by complex optical coatings: modelization and metrology (United States)

    Zerrad, Myriam; Lequime, Michel; Liukaityte, Simona; Amra, Claude


    Optical components realized for space applications have to be mastered in term of parasitic light. This paper present the last improvements performed at the Institute Fresnel to predict and measure scattering losses of optical components with a special care to complex optical coatings. Agreement between numerical models and metrology is now excellent. Some examples will be presented.

  13. Gynecologic specimen analysis by multiangle light scattering in a flow system

    Energy Technology Data Exchange (ETDEWEB)

    Salzman, G.C.; Crowell, J.M.; Hansen, K.M.; Ingram, M.; Mullaney, P.F.


    A flow-system instrument is described in which the laser light scattered by a mammalian cell is sampled simultaneously at up to 32 angles between 0/sup 0/ and 21/sup 0/ from the laser beam axis as the cell passes through the beam. The scatter pattern for each cell is stored by a computer for later analysis. Various data-processing techniques are discussed. Results of preliminary application of the instrument to the analysis of normal and abnormal gynecologic specimens are presented.

  14. Double-layered liquid crystal light shutter for control of absorption and scattering of the light incident to a transparent display device (United States)

    Huh, Jae-Won; Yu, Byeong-Hun; Shin, Dong-Myung; Yoon, Tae-Hoon


    Recently, a transparent display has got much attention as one of the next generation display devices. Especially, active studies on a transparent display using organic light-emitting diodes (OLEDs) are in progress. However, since it is not possible to obtain black color using a transparent OLED, it suffers from poor visibility. This inevitable problem can be solved by using a light shutter. Light shutter technology can be divided into two types; light absorption and scattering. However, a light shutter based on light absorption cannot block the background image perfectly and a light shutter based on light scattering cannot provide black color. In this work we demonstrate a light shutter using two liquid crystal (LC) layers, a light absorption layer and a light scattering layer. To realize a light absorption layer and a light scattering layer, we use the planar state of a dye-doped chiral nematic LC (CNLC) cell and the focal-conic state of a long-pitch CNLC cell, respectively. The proposed light shutter device can block the background image perfectly and show black color. We expect that the proposed light shutter can increase the visibility of a transparent display.

  15. Multiple light scattering and absorption in reef-building corals. (United States)

    Terán, Emiliano; Méndez, Eugenio R; Enríquez, Susana; Iglesias-Prieto, Roberto


    We present an experimental and numerical study of the effects of multiple scattering on the optical properties of reef-building corals. For this, we propose a simplified optical model of the coral and describe in some detail methods for characterizing the coral skeleton and the layer containing the symbiotic algae. The model is used to study the absorption of light by the layer of tissue containing the microalgae by means of Monte Carlo simulations. The results show that, through scattering, the skeleton homogenizes and enhances the light environment in which the symbionts live. We also present results that illustrate the modification of the internal light environment when the corals loose symbionts or pigmentation.

  16. Simulations of the Light Scattering Properties of Metal/Oxide Core/Shell Nanospheres

    Directory of Open Access Journals (Sweden)

    F. Ruffino


    Full Text Available Given the importance of the optical properties of metal/dielectric core/shell nanoparticles, in this work we focus our attention on the light scattering properties, within the Mie framework, of some specific categories of these noteworthy nanostructures. In particular, we report theoretical results of angle-dependent light scattering intensity and scattering efficiency for Ag/Ag2O, Al/Al2O2, Cu/Cu2O, Pd/PdO, and Ti/TiO2 core/shell nanoparticles as a function of the core radius/shell thickness ratio and on a relative comparison. The results highlight the light scattering characteristics of these systems as a function of the radius/shell thickness ratio, helping in the choice of the more suitable materials and sizes for specific applications (i.e., dynamic light scattering for biological and molecular recognition, increasing light trapping in thin-film silicon, organic solar cells for achieving a higher photocurrent.

  17. Measurement of bone mineral density via light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Ugryumova, Nadya; Matcher, Stephen John; Attenburrow, Don P [Biomedical Physics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)


    In this study we have investigated the potential of optical techniques to monitor changes in bone mineral density (BMD) via changes in scattering coefficient. For each of five bone samples, diffuse reflection and transmission coefficients were measured over the wavelength range 520-960 nm using an integrating sphere and CCD spectrometer. These were converted into optical absorption and scattering coefficients using a Monte Carlo inversion procedure. Measurements were made on samples immersed in formic acid solution for different lengths of time in order to investigate the effect of reduction in BMD on the optical properties. After full demineralization, the optical scattering coefficient fell by a factor 4. From the observed degree of fluctuation of the measurements, we estimate that BMD could be measured with an accuracy of 7% if optical scattering can be measured with an accuracy of 10%. We also report preliminary measurements of bone scattering using optical coherence tomography (OCT). An inter-side variability of 3% is obtained on dry samples with and without overlying periosteum. These results suggest that minimally invasive techniques for measuring optical scattering, such as OCT, may have a role in monitoring regional changes in BMD. This could be an important advance in our understanding of bone remodelling and its relationship to osteoarthritis. Both the integrating sphere and OCT measurements also suggest that light transport in bone is spatially anisotropic. OCT was used to assess probability of obtaining results in vivo.

  18. Quantum Interference and Entanglement Induced by Multiple Scattering of Light

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Mortensen, Asger; Lodahl, Peter


    We report on the effects of quantum interference induced by the transmission of an arbitrary number of optical quantum states through a multiple-scattering medium. We identify the role of quantum interference on the photon correlations and the degree of continuous variable entanglement between two...... output modes. It is shown that quantum interference survives averaging over all ensembles of disorder and manifests itself as increased photon correlations due to photon antibunching. Furthermore, the existence of continuous variable entanglement correlations in a volume speckle pattern is predicted. Our...... results suggest that multiple scattering provides a promising way of coherently interfering many independent quantum states of light of potential use in quantum information processing....

  19. Integrated pillar scatterers for speeding up classification of cell holograms. (United States)

    Lugnan, Alessio; Dambre, Joni; Bienstman, Peter


    The computational power required to classify cell holograms is a major limit to the throughput of label-free cell sorting based on digital holographic microscopy. In this work, a simple integrated photonic stage comprising a collection of silica pillar scatterers is proposed as an effective nonlinear mixing interface between the light scattered by a cell and an image sensor. The light processing provided by the photonic stage allows for the use of a simple linear classifier implemented in the electric domain and applied on a limited number of pixels. A proof-of-concept of the presented machine learning technique, which is based on the extreme learning machine (ELM) paradigm, is provided by the classification results on samples generated by 2D FDTD simulations of cells in a microfluidic channel.

  20. Dust grain characterization — Direct measurement of light scattering (United States)

    BartoÅ, P.; Pavlů, J.


    Dust grains play a key role in dusty plasma since they interact with the plasma we can use them to study plasma itself. The grains are illuminated by visible light (e.g., a laser sheet) and the situation is captured with camera. Despite of simplicity, light scattering on similar-to-wavelength sized grains is complex phenomenon. Interaction of the electromagnetic wave with material has to be computed with respect to Maxwell equations — analytic solution is nowadays available only for several selected shapes like sphere, coated sphere, or infinite cylinder. Moreover, material constants needed for computations are usually unknown. For computation result verification and material constant determination, we designed and developed a device directly measur­ing light scattering profiles. Single dust grains are trapped in the ultrasonic field (so called "acoustic levitation") and illuminated by the laser beam. Scattered light is then measured by a photodiode mounted on rotating platform. Synchronous detection is employed for a noise reduction. This setup brings several benefits against conventional methods: (1) it works in the free air, (2) the measured grain is captured for a long time, and (3) the grain could be of arbitrary shape.

  1. Feasibility of field-based light scattering spectroscopy (United States)

    Yang, Changhuei; Perelman, Lev T.; Wax, Adam; Dasari, Ramachandra R.; Feld, Michael S.


    Light scattering spectroscopy (LSS) is a new technique capable of accurately measuring the features of nuclei and other cellular organelles in situ. We present the considerations required to implement and interpret field- based detection in LSS, where the scattered electric field is detected interferometrically, and demonstrate that the technique is experimentally feasible. A theoretical formalism for modeling field-based LSS signals based on Mie scattering is presented. Phase-front uniformity is shown to play an important and novel role. Results of heterodyne experiments with polystyrene microspheres that localize LSS signals to a region about 30 micrometers in axial extent are reported. In addition, differences between field-based LSS and the earlier intensity-based LSS are discussed.

  2. Multiple light scattering in multilayered media: theory, experiments

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A. da; Andraud, C.; Charron, E.; Stout, B.; Lafait, J


    The model presented here is based on the resolution of the radiative transfer equation, by the Discrete Ordinate Method, in the steady-state domain. A matricial formulation leads to the resolution of the problem of light scattering through multislabs, with index mismatch at each interface. In that way, the angular distribution of out-going fluxes is obtained. A complete dissociation between volume and interfaces behaviors allows the introduction of elaborated theories to describe them properly. An analytical scattering theory based on the T-matrix formalism is introduced to account for interactions between scatterers, when high volume fractions are considered. Theoretical calculations are compared with experiments obtained with a spectro-scatterometer.

  3. Coherent multiple light scattering in Faraday active materials (United States)

    Schertel, L.; Aubry, G. J.; Aegerter, C. M.; Maret, G.


    Wave propagation in multiple scattering media shows various kinds of coherent phenomena such as coherent backscattering [1, 2] or Anderson localization [3], both of which are intimately connected to the concept of reciprocity. Manipulating reciprocity in such media is a powerful tool to study these phenomena in experiments [4]. Here we discuss the manipulation of reciprocity in reflection and transmission geometry for the case of light propagation in magneto-optical media. We show new experiments on coherent backscattering and speckle correlations in strongly scattering samples containing Faraday active materials (CeF3) with transport mean free path in the μm range, at low temperatures (T < 10 K) and high fields (B = 18 T). Under such conditions we observe the effect of a Faraday rotation saturation in multiple scattering measurements.

  4. Understanding the role of silica nanospheres with their light scattering and energy barrier properties in enhancing the photovoltaic performance of ZnO based solar cells. (United States)

    Banik, Avishek; Ansari, Mohammad Shaad; Sahu, Tushar Kanta; Qureshi, Mohammad


    The present study discusses the design and development of a dye sensitized solar cell (DSSC) using a hybrid composite of ZnO nanoparticles (ZnO NP) and silica nanospheres (SiO 2 NS). A ≈22% enhancement in the overall power conversion efficiency (PCE, η) was observed for the device fabricated with a binary hybrid composite of 1 wt% SiO 2 NS and ZnO NP compared to the pristine ZnO NP device. A systematic investigation revealed the dual function of the silica nanospheres in enhancing the device efficacy compared to the bare ZnO NP based device. Sub-micron sized SiO 2 NS can boost the light harvesting efficiency of the photoanode by optical confinement, resulting in increased propagation length of the incident light by multiple internal reflections, which was confirmed by UV-Vis diffused reflectance spectroscopy. Electrochemical impedance spectroscopic (EIS) analysis showed a reduced recombination of photo-generated electrons to the I - /I 3 - redox shuttle in the case of the composite photoanode. The higher recombination resistance (R ct ) in the case of a 1 wt% composite indicates that the SiO 2 NS serves as a partial energy barrier layer to retard the interfacial recombination (back transfer) of photo-generated electrons at the working electrode/electrolyte interface, increasing the device efficiency.

  5. Light source distribution and scattering phase function influence light transport in diffuse multi-layered media (United States)

    Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine


    Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

  6. Supercontinuum Light Sources for Hyperspectral Subsurface Laser Scattering

    DEFF Research Database (Denmark)

    Nielsen, Otto Højager Attermann; Dahl, Anders Lindbjerg; Larsen, Rasmus


    A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based on a super......A materials structural and chemical composition influences its optical scattering properties. In this paper we investigate the use of subsurface laser scattering (SLS) for inferring structural and chemical information of food products. We have constructed a computer vision system based...... on a supercontinuum laser light source and an Acousto- Optic Tunable Filter (AOTF) to provide a collimated light source, which can be tuned to any wavelength in the range from 480 to 900 nm. We present the newly developed hyperspectral vision system together with a proof-of-principle study of its ability...... to discriminate between dairy products with either similar chemical or structural composition. The combined vision system is a new way for industrial food inspection allowing non-intrusive online process inspection of parameters that is hard with existing technology....

  7. Dynamic light scattering on bioconjugated laser generated gold nanoparticles.

    Directory of Open Access Journals (Sweden)

    Massimo Zimbone

    Full Text Available Gold nanoparticles (AuNPs conjugated to DNA are widely used for biomedical targeting and sensing applications. DNA functionalization is easily reached on laser generated gold nanoparticles because of their unique surface chemistry, not reproducible by other methods. In this context, we present an extensive investigation concerning the attachment of DNA to the surface of laser generated nanoparticles using Dynamic Light Scattering and UV-Vis spectroscopy. The DNA conjugation is highlighted by the increase of the hydrodynamic radius and by the UV-Vis spectra behavior. Our investigation indicates that Dynamic Light Scattering is a suitable analytical tool to evidence, directly and qualitatively, the binding between a DNA molecule and a gold nanoparticle, therefore it is ideal to monitor changes in the conjugation process when experimental conditions are varied.

  8. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail:; Tufaile, A.P.B.


    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  9. Measurement of subcellular morphology by light scatter filtering with a digital micromirror device (United States)

    Pasternack, Robert M.; Qian, Zhen; Zheng, Jing-Yi; Boustany, Nada N.


    Light scattering methods for assessing structural properties of cells and tissues quantitatively measure morphometric parameters directly without the need for staining. We demonstrate an optical scattering filtering method used in a biological setting that is sensitive to quantifying object orientation and aspect ratio. These parameters are measured in cells both sensitive to and resistant to mitochondrial-mediated apoptosis, the latter having been demonstrated to have shorter mitochondria than apoptosis competent cells. The implementation of the digital micromirror device (DMD) allows for robust filtering of the scatter data, which we implement with Gabor-like filters chosen for their ability to intelligently confine the filter response both in the image and in the scatter regimes. By strategically applying Gabor-like filters to the specific frequencies and orientations in the scatter data, relative changes in object size, orientation and aspect ratio may be derived. Furthermore, using a DMD and filtering the optical scatter data in analog allows us to decouple image resolution from frequency resolution and measure these parameters with high sensitivity for objects within the resolution of the optical system despite an undersampled, lower resolution digital image. As a result, this measurement may be made at lower magnifications with higher throughput and ultimately on a larger population of living and unstained cells imaged simultaneously.

  10. Multivariate analysis of light scattering spectra of liquid dairy products (United States)

    Khodasevich, M. A.


    Visible light scattering spectra from the surface layer of samples of commercial liquid dairy products are recorded with a colorimeter. The principal component method is used to analyze these spectra. Vectors representing the samples of dairy products in a multidimensional space of spectral counts are projected onto a three-dimensional subspace of principal components. The magnitudes of these projections are found to depend on the type of dairy product.

  11. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey


    VISIBLE LIGHT SCATTER AS A QUANTITATIVE INFORMATION SOURCE ON MILK CONSTITUENTS A. Melenteva 1, S. Kucheryavski 2, A. Bogomolov 1,31Samara State Technical University, Molodogvardeyskaya Street 244, 443100 Samara, Russia. 2Aalborg University, campus Esbjerg, Niels Bohrs vej 8, 6700 Esbjerg, Denmar...... research area are presented and discussed. References: [1] A. Bogomolov, S. Dietrich, B. Boldrini, R.W. Kessler, Food Chemistry (2012), doi:10.1016/j.foodchem.2012.02.077....

  12. Factors affecting light scatter in contact lens wearers. (United States)

    Elliott, D B; Mitchell, S; Whitaker, D


    We measured forward light scatter at 3.5, 10, and 28 degrees using a portable stray light meter. Subjects included 66 normal subjects (age range 19 to 79 years), 17 established hydrophilic contact lens wearers, and 15 rigid gas permeable (RGP) contact lens wearers. Contact lens deposits were measured using a modified Rudko procedure and a Leitz/Wild Makroscope M240. Corneal health was assessed using slitlamp biomicroscopy. Results showed a significant increase in light scatter with age, particularly after the age of 40 years. Stray light scores were significantly lower in pigmented non-Caucasian subjects, particularly at larger angles. The stray light scores were significantly greater in contact lens wearers than in age-matched normals, but were not found to correlate with the amount of lens deposits. Scores from hydrophilic lens wearers after removal of their lenses were significantly higher than results from RGP wearers after removal of their lenses and from age-matched normals. This suggests the presence of subclinical corneal edema in some of these subjects.

  13. Light beating spectroscopy of Brillouin scattering in gases and solids (United States)

    Yogi, Takeshi; Sakai, Keiji; Takagi, Kenshiro


    The experimental system of optical beating spectroscopy was improved, and the increased sensitivity and frequency resolution were demonstrated in the Brillouin scattering experiments in solids, crown glass (BK7), and polymethylmetacrylate (PMMA), and also in gases, air, and nitrogen. For their weak light scattering ability, these substances are very tough specimens for Brillouin scattering studies, and the classical spectrometer of Fabry-Pérot étalon has been so far used for the frequency analysis. The phonon peaks were observed with the present light beating system in BK7 at room temperature over the wave number range from k /2π=1.03×104to8.84×104m-1 (corresponding frequency from 61.6to548MHz), and the spectra were fitted with Gaussian curves since a condenser lens in the incident light path caused a large instrumental width that overwhelmed the intrinsic phonon width. The spectra in PMMA were analyzed with Voigt functions. The dispersion relations obtained in these solids were in good agreement with the literature values of ultrasonic velocity. The spectra in air were well fitted with Lorentzian curve representing the phonon lifetime, and the absorption as well as the phase velocity was obtained.

  14. Research Update: A minimal region of squid reflectin for vapor-induced light scattering (United States)

    Dennis, Patrick B.; Singh, Kristi M.; Vasudev, Milana C.; Naik, Rajesh R.; Crookes-Goodson, Wendy J.


    Reflectins are a family of proteins found in the light manipulating cells of cephalopods. These proteins are made up of a series of conserved repeats that contain highly represented amino acids thought to be important for function. Previous studies demonstrated that recombinant reflectins cast into thin films produced structural colors that could be dynamically modulated via changing environmental conditions. In this study, we demonstrate light scattering from reflectin films following exposure to a series of water vapor pulses. Analysis of film surface topography shows that the induction of light scatter is accompanied by self-assembly of reflectins into micro- and nanoscale features. Using a reductionist strategy, we determine which reflectin repeats and sub-repeats are necessary for these events following water vapor pulsing. With this approach, we identify a singly represented, 23-amino acid region in reflectins as being sufficient to recapitulate the light scattering properties observed in thin films of the full-length protein. Finally, the aqueous stability of reflectin films is leveraged to show that pre-exposure to buffers of varying pH can modulate the ability of water vapor pulses to induce light scatter and protein self-assembly.

  15. Controlling stimulated Raman scattering by two-color light in inertial confinement fusion (United States)

    Liu, Z. J.; Chen, Y. H.; Zheng, C. Y.; Cao, L. H.; Li, B.; Xiang, J.; Hao, L.; Lan, K.


    A method is proposed to control the stimulated Raman scattering in the inertial confinement fusion by using auxiliary 2ω light to suppress the stimulated Raman scattering of the 3ω light. In this scheme, inverse bremsstrahlung absorption and parametric instabilities in the 2ω light increase the electron temperature and the plasma-density fluctuation, thus preventing the development of Raman scattering of the 3ω light. This scheme is successfully demonstrated by both one-dimensional kinetic simulations and two-dimensional radiative hydrodynamic simulations. The one-dimensional Vlasov results show that the time-averaged transmissivity of the 3ω light increases from 0.75 to 0.95 under certain conditions. Results obtained using the particle-in-cell method with Monte Carlo collisions show that the electron temperature is greatly increased with the increasing intensity of the 2ω light. The two-dimensional radiative hydrodynamic simulation results show that the electron temperature increases from 3.2 keV to 3.5 keV, and the time-averaged backscattering level decreases from 0.28 to 0.1 in the presence of the auxiliary 2ω light.

  16. Engineering of light confinement in strongly scattering disordered media. (United States)

    Riboli, Francesco; Caselli, Niccolò; Vignolini, Silvia; Intonti, Francesca; Vynck, Kevin; Barthelemy, Pierre; Gerardino, Annamaria; Balet, Laurent; Li, Lianhe H; Fiore, Andrea; Gurioli, Massimo; Wiersma, Diederik S


    Disordered photonic materials can diffuse and localize light through random multiple scattering, offering opportunities to study mesoscopic phenomena, control light-matter interactions, and provide new strategies for photonic applications. Light transport in such media is governed by photonic modes characterized by resonances with finite spectral width and spatial extent. Considerable steps have been made recently towards control over the transport using wavefront shaping techniques. The selective engineering of individual modes, however, has been addressed only theoretically. Here, we experimentally demonstrate the possibility to engineer the confinement and the mutual interaction of modes in a two-dimensional disordered photonic structure. The strong light confinement is achieved at the fabrication stage by an optimization of the structure, and an accurate and local tuning of the mode resonance frequencies is achieved via post-fabrication processes. To show the versatility of our technique, we selectively control the detuning between overlapping localized modes and observe both frequency crossing and anti-crossing behaviours, thereby paving the way for the creation of open transmission channels in strongly scattering media.

  17. Efficient Light Extraction from Organic Light-Emitting Diodes Using Plasmonic Scattering Layers

    Energy Technology Data Exchange (ETDEWEB)

    Rothberg, Lewis


    Our project addressed the DOE MYPP 2020 goal to improve light extraction from organic light-emitting diodes (OLEDs) to 75% (Core task 6.3). As noted in the 2010 MYPP, “the greatest opportunity for improvement is in the extraction of light from [OLED] panels”. There are many approaches to avoiding waveguiding limitations intrinsic to the planar OLED structure including use of textured substrates, microcavity designs and incorporating scattering layers into the device structure. We have chosen to pursue scattering layers since it addresses the largest source of loss which is waveguiding in the OLED itself. Scattering layers also have the potential to be relatively robust to color, polarization and angular distributions. We note that this can be combined with textured or microlens decorated substrates to achieve additional enhancement.

  18. Optimization of the Photoanode of CdS Quantum Dot-Sensitized Solar Cells Using Light-Scattering TiO2 Hollow Spheres (United States)

    Marandi, Maziar; Rahmani, Elham; Ahangarani Farahani, Farzaneh


    CdS quantum dot-sensitized solar cells (QDSCs) have been fabricated and their photoanode optimized by altering the thickness of the photoelectrode and CdS deposition conditions and applying a ZnS electron-blocking layer and TiO2 hollow spheres. Hydrothermally grown TiO2 nanocrystals (NCs) with dominant size of 20 nm were deposited as a sublayer in the photoanode with thickness in the range from 5 μm to 10 μm using a successive ionic layer adsorption and reaction (SILAR) method. The number of deposition cycles was altered over a wide range to obtain optimized sensitization. Photoanode thickness and number of CdS sensitization cycles around the optimum values were selected and used for ZnS deposition. ZnS overlayers were also deposited on the surface of the photoanodes using different numbers of cycles of the SILAR process. The best QDSC with the optimized photoelectrode demonstrated a 153% increase in efficiency compared with a similar cell with ZnS-free photoanode. Such bilayer photoelectrodes were also fabricated with different thicknesses of TiO2 sublayers and one overlayer of TiO2 hollow spheres (HSs) with external diameter of 500 nm fabricated by liquid-phase deposition with carbon spheres as template. The optimization was performed by changing the photoanode thickness using a wide range of CdS sensitizing cycles. The maximum energy conversion efficiency was increased by about 77% compared with a similar cell with HS-free photoelectrode. The reason was considered to be the longer path length of the incident light inside the photoanode and greater light absorption. A ZnS blocking layer was overcoated on the surface of the bilayer photoanode with optimized thickness. The number of CdS sensitization cycles was also changed around the optimized value to obtain the best QDSC performance. The number of ZnS deposition cycles was also altered in a wide range for optimization of the photovoltaic performance. It was shown that the maximum efficiency was increased by

  19. Optimization of the Photoanode of CdS Quantum Dot-Sensitized Solar Cells Using Light-Scattering TiO2 Hollow Spheres (United States)

    Marandi, Maziar; Rahmani, Elham; Ahangarani Farahani, Farzaneh


    CdS quantum dot-sensitized solar cells (QDSCs) have been fabricated and their photoanode optimized by altering the thickness of the photoelectrode and CdS deposition conditions and applying a ZnS electron-blocking layer and TiO2 hollow spheres. Hydrothermally grown TiO2 nanocrystals (NCs) with dominant size of 20 nm were deposited as a sublayer in the photoanode with thickness in the range from 5 μm to 10 μm using a successive ionic layer adsorption and reaction (SILAR) method. The number of deposition cycles was altered over a wide range to obtain optimized sensitization. Photoanode thickness and number of CdS sensitization cycles around the optimum values were selected and used for ZnS deposition. ZnS overlayers were also deposited on the surface of the photoanodes using different numbers of cycles of the SILAR process. The best QDSC with the optimized photoelectrode demonstrated a 153% increase in efficiency compared with a similar cell with ZnS-free photoanode. Such bilayer photoelectrodes were also fabricated with different thicknesses of TiO2 sublayers and one overlayer of TiO2 hollow spheres (HSs) with external diameter of 500 nm fabricated by liquid-phase deposition with carbon spheres as template. The optimization was performed by changing the photoanode thickness using a wide range of CdS sensitizing cycles. The maximum energy conversion efficiency was increased by about 77% compared with a similar cell with HS-free photoelectrode. The reason was considered to be the longer path length of the incident light inside the photoanode and greater light absorption. A ZnS blocking layer was overcoated on the surface of the bilayer photoanode with optimized thickness. The number of CdS sensitization cycles was also changed around the optimized value to obtain the best QDSC performance. The number of ZnS deposition cycles was also altered in a wide range for optimization of the photovoltaic performance. It was shown that the maximum efficiency was increased by

  20. Ultraviolet refractometry using field-based light scattering spectroscopy (United States)

    Fu, Dan; Choi, Wonshik; Sung, Yongjin; Oh, Seungeun; Yaqoob, Zahid; Park, YongKeun; Dasari, Ramachandra R.; Feld, Michael S.


    Accurate refractive index measurement in the deep ultraviolet (UV) range is important for the separate quantification of biomolecules such as proteins and DNA in biology. This task is demanding and has not been fully exploited so far. Here we report a new method of measuring refractive index using field-based light scattering spectroscopy, which is applicable to any wavelength range and suitable for both solutions and homogenous objects with well-defined shape such as microspheres. The angular scattering distribution of single microspheres immersed in homogeneous media is measured over the wavelength range 260 to 315 nm using quantitative phase microscopy. By least square fitting the observed scattering distribution with Mie scattering theory, the refractive index of either the sphere or the immersion medium can be determined provided that one is known a priori. Using this method, we have measured the refractive index dispersion of SiO2 spheres and bovine serum albumin (BSA) solutions in the deep UV region. Specific refractive index increments of BSA are also extracted. Typical accuracy of the present refractive index technique is ≤0.003. The precision of refractive index measurements is ≤0.002 and that of specific refractive index increment determination is ≤0.01 mL/g. PMID:20372622

  1. Focusing light through scattering media by transmission matrix inversion. (United States)

    Xu, Jian; Ruan, Haowen; Liu, Yan; Zhou, Haojiang; Yang, Changhuei


    Focusing light through scattering media has broad applications in optical imaging, manipulation and therapy. The contrast of the focus can be quantified by peak-to-background intensity ratio (PBR). Here, we theoretically and numerically show that by using a transmission matrix inversion method to achieve focusing, within a limited field of view and under a low noise condition in transmission matrix measurements, the PBR of the focus can be higher than that achieved by conventional methods such as optical phase conjugation or feedback-based wavefront shaping. Experimentally, using a phase-modulation spatial light modulator, we increase the PBR by 66% over that achieved by conventional methods based on phase conjugation. In addition, we demonstrate that, within a limited field of view and under a low noise condition in transmission matrix measurements, our matrix inversion method enables light focusing to multiple foci with greater fidelity than those of conventional methods.

  2. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University (United States)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang


    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  3. Microchip Flow Cytometer with Integrated Polymer Optical Elements for Measurement of Scattered Light

    DEFF Research Database (Denmark)

    Wang, Zhenyu; El-Ali, Jamil; Perch-Nielsen, Ivan Ryberg


    Flow cytometry is a very powerful method for biophysical measurement of microparticles, such as cells and bacteria. In this paper, we report an innovative microsystem, in which several different optical elements (waveguides, lenses and fiber-to-waveguide couplers) are integrated with microfluidic...... extinction showed excellent linear relationship with the sizes of the beads. To our knowledge this is the first time forward scattered light and incident light extinction were measured in a microsystem using integrated optics. The microsystem can be applied for analyzing different kinds of particles...... and cells, and can easily be integrated with other microfluidic components....

  4. Confocal Light Absorption and Scattering Spectroscopic (CLASS) imaging: From cancer detection to sub-cellular function (United States)

    Qiu, Le

    Light scattering spectroscopy (LSS), an optical technique that relates the spectroscopic properties of light elastically scattered by small particles to their size, refractive index and shape, has been recently successfully employed for sensing morphological and biochemical properties of epithelial tissues and cells in vivo. LSS does not require exogenous markers, is non-invasive, and, due to its multispectral nature, can sense biological structures well beyond the diffraction limit. All that makes LSS be a very good candidate to be used both in clinical medicine for in vivo detection of disease and in cell biology to monitor cell function on the organelle scale. Recently we developed two LSS-based imaging modalities: clinical Polarized LSS (PLSS) Endoscopic Technique for locating early pre-cancerous changes in GI tract and Confocal Light Absorption and Scattering Spectroscopic (CLASS) Microscopy for studying cells in vivo without exogenous markers. One important application of the clinical PLSS endoscopic instrument, a noncontact scanning imaging device compatible with the standard clinical endoscopes and capable of detecting dysplastic changes, is to serve as a guide for biopsy in Barrett's esophagus (BE). The instrument detects parallel and perpendicular components of the polarized light, backscattered from epithelial tissues, and determines characteristics of epithelial nuclei from the residual spectra. It also can find tissue oxygenation, hemoglobin content and other properties from the diffuse light component. By rapidly scanning esophagus the PLSS endoscopic instrument makes sure the entire BE portion is scanned and examined for the presence of dysplasia. CLASS microscopy, on the other hand, combines principles of light scattering spectroscopy (LSS) with confocal microscopy. Its main purpose is to image cells on organelle scale in vivo without the use of exogenous labels which may affect the cell function. The confocal geometry selects specific region and

  5. Neutron and light scattering studies of polymers adsorbed on laponite

    CERN Document Server

    Nelson, A R J


    The adsorption of poly(ethylene oxide) (PEO) and various poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic) copolymers onto the synthetic clay Laponite, was investigated using Small Angle Neutron Scattering (SANS) and Dynamic Light Scattering (DLS). The Laponite particles are anisotropic, with a relatively high aspect ratio; but are the same order of magnitude in size as the polymer radius of gyration. Consequently, the particles present a radically different adsorption geometry compared to a locally planar interface, that is assumed by the majority of adsorption studies. The PEO homo-polymer formed thin layers, with the layer thickness being much smaller on the face than on the edge of the particle. Furthermore, the face thickness remained constant with increasing molecular weight, unlike the edge thickness, which grew with a small power law dependence on the molecular weight. Although the hydrodynamic thicknesses (DLS) were larger than those observed with SANS, the layer thicknesses ...

  6. Resonant depolarized dynamic light scattering of silver nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Zimbone, M., E-mail: [CNR-IMM (Italy); Messina, E. [IPCF-CNR Istituto per i Processi Chimico-Fisici (Italy); Compagnini, G.; Fragalà, M. E. [Dipartimento di Scienze Chimiche (Italy); Calcagno, L. [Dipartimento di Fisica ed Astronomia (Italy)


    Polarized and depolarized dynamic light scattering (DDLS) methodology was carried out on silver nanoplatelets showing strong plasmon-enhanced scattering. The hydrodynamic properties of the nanoparticles were determined by measuring the translation diffusion coefficient for “out resonant” condition and the rotational diffusion coefficient for “in resonant” condition. The results have been interpreted by applying an oblate ellipsoidal model, which allows a direct evaluation of nanoplatelets’ size and shape in agreement with scanning electron microscopy. The characterised nanoplatelets reveal a transversal size of 20 nm and a longitudinal length in the range 65–92 nm. Our investigation shows that DDLS in resonant condition is a simple and powerful technique to determine the size and shape of plasmonic nanoparticles and it can be successfully applied to characterise the dynamics of metallic nanoplatelets.

  7. Dynamic light scattering in veterinary medicine: refinement of diagnostic criteria (United States)

    Dubin, Stephen; Zietz, Stanley; Gabriel, Karl L.; Gabriel, David; DellaVecchia, Michael A.; Ansari, Rafat R.


    In dynamic light scattering (DLS), the structure or material of interest, suspended in a fluid, is illuminated by a beam of laser light and the scattered light is interpreted in terms of diffusion coefficient, particle size or its distribution. DLS has shown clear promise as a non-invasive, objective and precise diagnostic modality for investigation of lens opacity (cataract) and other medical and toxicological problems. The clinical potential of LDS has been demonstrated in several species both in vivo and in vitro. In many clinical cases, discernment between normal and diseased patients is possible by simple inspection of the particle size distribution. However a more rigorous and sensitive classification scheme is needed, particularly for evaluation of therapy and estimation of tissue injury. The data supplied by DLS investigation is inherently multivariate and its most efficient interpretation requires a multivariate approach which includes the variability among specimens as well as any correlation among the variables (e.g. across the particle size distribution). We present a brief review of DLS methodology, illustrative data and our efforts toward a diagnostic classification scheme. In particular we will describe application of the Mahalanobis distance and related statistical methods to DLS data.

  8. Wide-field imaging through scattering media by scattered light fluorescence microscopy (United States)

    Zhou, Yulan; Li, Xun


    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

  9. Influence of low concentrations of scatterers and signal detection time on the results of their measurements using dynamic light scattering (United States)

    Bunkin, N. F.; Shkirin, A. V.; Suyazov, N. V.; Chaikov, L. L.; Chirikov, S. N.; Kirichenko, M. N.; Nikiforov, S. D.; Tymper, S. I.


    The influence of limited detection time on the form of the autocorrelation function (ACF) has been analysed for measurements in low-concentration suspensions by dynamic light scattering with allowance for the spatial distribution of the laser beam intensity. The general view of the ACF of the scattered light intensity is obtained for a Gaussian beam and a finite measurement time. The results of the theoretical analysis are compared with the experimental data and the results obtained by computer simulation of the scattering from an ensemble of particles involved in Brownian motion in a Gaussian beam. It is shown that, in the case of low suspension concentrations, the ACF distortions related to finite detection time lead to underestimation of the particle sizes and occurrence of an artefact peak in the distribution of the scattered light intensity over scatterer sizes. An empirical dependence of the measured size of particles on their number in the scattering volume is found.

  10. Longitudinal W boson scattering in a light scalar top scenario (United States)

    Ishiwata, Koji; Yonekura, Yuki


    Scalar tops in the supersymmetric model affect the potential of the standard model-like Higgs at the quantum level. In light of the equivalence theorem, the deviation of the potential from the standard model can be traced by longitudinal gauge bosons. In this work, high-energy longitudinal W boson scattering is studied in a TeV-scale scalar top scenario. O (1 - 10 %) deviation from the standard model prediction in the differential cross section is found, depending on whether the observed Higgs mass is explained only by scalar tops or by additional contributions at a higher scale.

  11. Spectator-Tagged Deeply Virtual Compton Scattering on Light Nuclei


    Armstrong, Whitney; Arrington, John; Cloët, Ian; Freese, Adam; Hafidi, Kawtar; Hattawy, Mohammad; Riordan, Seamus; Johnston, Sereres; Potteveld, David; Reimer, Paul; Ye, Zhihong; Ball, Jacques; Defurne, Maxime; Garcon, Michel; Moutarde, Herve


    The three-dimensional picture of quarks and gluons in the proton is set to be revealed through Deeply virtual Compton scattering while a critically important puzzle in the one-dimensional picture remains, namely, the origins of the EMC effect. Incoherent nuclear DVCS, i.e. DVCS on a nucleon inside a nucleus, can reveal the 3D partonic structure of the bound nucleon and shed a new light on the EMC effect. However, the Fermi motion of the struck nucleon, off-shell effects and final-state intera...

  12. Polarized scattered light from self-luminous exoplanets. Three-dimensional scattering radiative transfer with ARTES (United States)

    Stolker, T.; Min, M.; Stam, D. M.; Mollière, P.; Dominik, C.; Waters, L. B. F. M.


    Context. Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a horizontally-inhomogeneous atmosphere causes the disk-integrated polarization of the thermal radiation to be linearly polarized, possibly detectable with the newest generation of high-contrast imaging instruments. Aims: We aim to investigate the effect of latitudinal and longitudinal cloud variations, circumplanetary disks, atmospheric oblateness, and cloud particle properties on the integrated degree and direction of polarization in the near-infrared. We want to understand how 3D atmospheric asymmetries affect the polarization signal in order to assess the potential of infrared polarimetry for direct imaging observations of planetary-mass companions. Methods: We have developed a three-dimensional Monte Carlo radiative transfer code (ARTES) for scattered light simulations in (exo)planetary atmospheres. The code is applicable to calculations of reflected light and thermal radiation in a spherical grid with a parameterized distribution of gas, clouds, hazes, and circumplanetary material. A gray atmosphere approximation is used for the thermal structure. Results: The disk-integrated degree of polarization of a horizontally-inhomogeneous atmosphere is maximal when the planet is flattened, the optical thickness of the equatorial clouds is large compared to the polar clouds, and the clouds are located at high altitude. For a flattened planet, the integrated polarization can both increase or decrease with respect to a spherical planet which depends on the horizontal distribution and optical thickness of the clouds. The direction of polarization can be either parallel or perpendicular to the projected direction of the rotation axis when clouds are zonally distributed. Rayleigh scattering by submicron-sized cloud particles will maximize the polarimetric signal whereas the integrated degree of polarization is significantly reduced with micron

  13. Light-scattering studies of bull spermatozoa. II. Interaction and concentration effects.


    Woolford, M.W.; Harvey, J D


    The complete autocorrelation function of the intensity fluctuations of laser light scattered from motile bull spermatozoa is shown to depend upon several factors not previously considered. Samples of bull spermatozoa generally contain a substantial proportion of dead cells, which give rise to slowly decaying components of the autocorrelation function. Whereas previous work has concentrated on the form of the fast decaying autocorrelation component, we are concerned here with the relative ampl...

  14. Correlation and image recognition with surface-scattered light. (United States)

    Christie, S; Kvasnik, F


    Image recognition by use of coherent optical processors and light diffusely scattered from the surface of an optically rough object is reported. A theoretical description is presented and shows that the image speckles are carriers for the Fourier spectra of the object at the matched spatial-filter plane. Experimental results of optical autocorrelation and cross correlation are given. The change in the intensity of the correlation peak that arises from the translation and the rotation of objects and from the lateral and axial movements of the matched filter are examined. The system is shown to be tolerant to misalignments in the positions of the object and matched filter. It is also shown that, when diffuse light is input into the coherent optical processor, the position of the Fourier plane is no longer precisely defined and spatial multiplexing would be possible.

  15. Investigating the Microstructure of Carbopol by Light Scattering (United States)

    Lee, David; Bailey, Arthur; Frisken, Barbara


    Carbopol, a family of cross-linked acrylic acid-based polymers and a well-known thickener used in personal care, household and industrial products, is often used as a model yield-stress fluid because it is transparent and its rheological properties can be precisely tuned by sample preparation conditions. Carbopol dispersions behave as an elastic solid but they will flow when the applied stress exceeds a sample-dependent yield value. Both the yield stress phenomena and the range of potential applications recommend study of the microscopic structure and properties of yield stress fluids as this will lead to a fundamental understanding of this behaviour. Light scattering experiments investigating Carbopol ETD2050 dispersed in water have revealed that the Carbopol microstructure consists of a highly cross-linked inner region surrounded by a lightly cross-linked outer region. Experiments also show that the length scales and mass fractal dimension depend on the sample concentration and pH.

  16. Galactic Latitude Dependence of Near-infrared Diffuse Galactic Light: Thermal Emission or Scattered Light? (United States)

    Sano, K.; Matsuura, S.


    Near-infrared (IR) diffuse Galactic light (DGL) consists of scattered light and thermal emission from interstellar dust grains illuminated by the interstellar radiation field (ISRF). At 1.25 and 2.2 μ {{m}}, a recent observational study shows that intensity ratios of the DGL to interstellar 100 μ {{m}} dust emission steeply decrease toward high Galactic latitudes (b). In this paper, we investigate the origin(s) of the b-dependence on the basis of models of thermal emission and scattered light. Combining a thermal emission model with the regional variation of the polycyclic aromatic hydrocarbon abundance observed with Planck, we show that the contribution of the near-IR thermal emission component to the observed DGL is lower than ∼ 20 % . We also examine the b-dependence of the scattered light, assuming a plane–parallel Galaxy with smooth distributions of the ISRF and dust density along the vertical direction, and assuming a scattering phase function according to a recently developed model of interstellar dust. We normalize the scattered light intensity to the 100 μ {{m}} intensity corrected for deviation from the cosecant-b law according to the Planck observation. As the result, the present model that considers the b-dependence of dust and the ISRF properties can account for the observed b-dependence of the near-IR DGL. However, the uncertainty in the correction for the 100 μ {{m}} emission is large, and other normalizing quantities may be appropriate for a more robust analysis of the DGL.


    Energy Technology Data Exchange (ETDEWEB)

    Birnstiel, Tilman; Andrews, Sean M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pinilla, Paola; Kama, Mihkel, E-mail:, E-mail:, E-mail:, E-mail: [Leiden Observatory, P.O. Box 9513, 2300 RA, Leiden (Netherlands)


    Recent imaging of protoplanetary disks with high resolution and contrast have revealed a striking variety of substructure. Of particular interest are cases where near-infrared scattered light images show evidence for low-intensity annular “gaps.” The origins of such structures are still uncertain, but the interaction of the gas disk with planets is a common interpretation. We study the impact that the evolution of the solid material can have on the observable properties of disks in a simple scenario without any gravitational or hydrodynamical disturbances to the gas disk structure. Even with a smooth and continuous gas density profile, we find that the scattered light emission produced by small dust grains can exhibit ring-like depressions similar to those presented in recent observations. The physical mechanisms responsible for these features rely on the inefficient fragmentation of dust particles. The occurrence and position of the proposed “gap” features depend most strongly on the dust-to-gas ratio, the fragmentation threshold velocity, the strength of the turbulence, and the age of the disk, and should be generic (at some radius) for typically adopted disk parameters. The same physical processes can affect the thermal emission at optically thin wavelengths (∼1 mm), although the behavior can be more complex; unlike for disk–planet interactions, a “gap” should not be present at these longer wavelengths.

  18. Fining of Red Wine Monitored by Multiple Light Scattering. (United States)

    Ferrentino, Giovanna; Ramezani, Mohsen; Morozova, Ksenia; Hafner, Daniela; Pedri, Ulrich; Pixner, Konrad; Scampicchio, Matteo


    This work describes a new approach based on multiple light scattering to study red wine clarification processes. The whole spectral signal (1933 backscattering points along the length of each sample vial) were fitted by a multivariate kinetic model that was built with a three-step mechanism, implying (1) adsorption of wine colloids to fining agents, (2) aggregation into larger particles, and (3) sedimentation. Each step is characterized by a reaction rate constant. According to the first reaction, the results showed that gelatin was the most efficient fining agent, concerning the main objective, which was the clarification of the wine, and consequently the increase in its limpidity. Such a trend was also discussed in relation to the results achieved by nephelometry, total phenols, ζ-potential, color, sensory, and electronic nose analyses. Also, higher concentrations of the fining agent (from 5 to 30 g/100 L) or higher temperatures (from 10 to 20 °C) sped up the process. Finally, the advantage of using the whole spectral signal vs classical univariate approaches was demonstrated by comparing the uncertainty associated with the rate constants of the proposed kinetic model. Overall, multiple light scattering technique showed a great potential for studying fining processes compared to classical univariate approaches.

  19. Online submicron particle sizing by dynamic light scattering using autodilution (United States)

    Nicoli, David F.; Elings, V. B.


    Efficient production of a wide range of commercial products based on submicron colloidal dispersions would benefit from instrumentation for online particle sizing, permitting real time monitoring and control of the particle size distribution. Recent advances in the technology of dynamic light scattering (DLS), especially improvements in algorithms for inversion of the intensity autocorrelation function, have made it ideally suited to the measurement of simple particle size distributions in the difficult submicron region. Crucial to the success of an online DSL based instrument is a simple mechanism for automatically sampling and diluting the starting concentrated sample suspension, yielding a final concentration which is optimal for the light scattering measurement. A proprietary method and apparatus was developed for performing this function, designed to be used with a DLS based particle sizing instrument. A PC/AT computer is used as a smart controller for the valves in the sampler diluter, as well as an input-output communicator, video display and data storage device. Quantitative results are presented for a latex suspension and an oil-in-water emulsion.

  20. Flow speed measurement using two-point collective light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeier, N.P


    Measurements of turbulence in plasmas and fluids using the technique of collective light scattering have always been plagued by very poor spatial resolution. In 1994, a novel two-point collective light scattering system for the measurement of transport in a fusion plasma was proposed. This diagnostic method was design for a great improvement of the spatial resolution, without sacrificing accuracy in the velocity measurement. The system was installed at the W7-AS steallartor in Garching, Germany, in 1996, and has been operating since. This master thesis is an investigation of the possible application of this new method to the measurement of flow speeds in normal fluids, in particular air, although the results presented in this work have significance for the plasma measurements as well. The main goal of the project was the experimental verification of previous theoretical predictions. However, the theoretical considerations presented in the thesis show that the method can only be hoped to work for flows that are almost laminar and shearless, which makes it of very small practical interest. Furthermore, this result also implies that the diagnostic at W7-AS cannot be expected to give the results originally hoped for. (au) 1 tab., 51 ills., 29 refs.

  1. Efficiency Enhancement of Gallium Arsenide Photovoltaics Using Solution-Processed Zinc Oxide Nanoparticle Light Scattering Layers

    Directory of Open Access Journals (Sweden)

    Yangsen Kang


    Full Text Available We demonstrate a high-throughput, solution-based process for subwavelength surface texturing of a III-V compound solar cell. A zinc oxide (ZnO nanoparticle ink is spray-coated directly on top of a gallium arsenide (GaAs solar cell. The nanostructured ZnO films have demonstrated antireflection and light scattering properties over the visible/near-infrared (NIR spectrum. The results show a broadband spectral enhancement of the solar cell external quantum efficiency (EQE, a 16% enhancement of short circuit current, and a 10% increase in photovoltaic efficiency.

  2. Enhanced photovoltaic performance utilizing effective charge transfers and light scattering effects by the combination of mesoporous, hollow 3D-ZnO along with 1D-ZnO in CdS quantum dot sensitized solar cells. (United States)

    Chetia, Tridip Ranjan; Barpuzary, Dipankar; Qureshi, Mohammad


    A combination of 3-dimensional (3D) hollow mesoporous ZnO microspheres (ZnO HMSP) and vertically grown one-dimensional ZnO nanowires (1D ZnO NWs) on a fluorine doped tin oxide (FTO) coated glass substrate has been investigated as a photoanode for a CdS quantum dot-sensitized solar cell (QSSC). A comparative study of the photovoltaic performance of the solar cell with devices fabricated with pristine ZnO HMSPs and ZnO NWs was carried out. The proposed photovoltaic device exhibits an enhancement in power conversion efficiency (PCE) upto ∼74% and ∼35%, as compared to the 1D ZnO NW and ZnO HMSP based solar cells. The maximum incident photon-to-current conversion efficiency (IPCE) for the solar cell was observed to be ∼40%, whereas for the devices fabricated with bare ZnO HMSP and ZnO NW the IPCE were only ∼32% and ∼19%, respectively. The enhanced photovoltaic performance of the solar cell is attributed to the high Brunauer-Emmett-Teller (BET) surface area, efficient light-scattering effects and facilitated diffusion of the electrolyte for better functioning of the redox couple (S(2-)/Sn(2-)) in the hybrid photoanode. Moreover, a faster electron transport through 1D ZnO NWs provides better charge collection from the photoactive layer, which leads to an increase in the short circuit current density of the device. The present study highlights the design and development of a new hybrid photoanode for solar harvesting.

  3. Polyelectrolyte Conformation, Interactions and Hydrodynamics as Studied by Light Scattering. (United States)

    Ghosh, Snehasish

    Polyelectrolyte conformation, interactions and hydrodynamics show a marked dependence on the ionic strength (C_{rm s}) of the medium, the concentration (C_{rm p}) of the polymer itself and their charge density (xi). The apparent electrostatic persistence length obtained from static light scattering varied approximately as the inverse square root of C _{rm s} for highly pure, high molecular weight hyaluronate (HA) as well as for variably ionized acrylamide/sodium acrylate copolymers (NaPAA), and linearly with xi. The experimental values of persistence length and second virial coefficient (A_2) are compared to predictions from theories based on the Debye-Huckel approximation for the Poisson-Boltzmann equation and on excluded-volume. Although the mean square radius of gyration () depended strongly on C _{rm s}. decreasing with increasing C_{rm s} for both HA and NaPAA indicating clear evidence of polyion expansion, dynamic light scattering values of the translational diffusion coefficient (D) remains constant when extrapolated to infinite polymer concentration for both the polymers. The behavior of D is compared to predictions from coupled mode theory in the linear limit. The effects of NaOH on the conformations, interactions, diffusion and hydrolysis rates of HA are characterized in detail using static, dynamic and time-dependent light scattering supplemented by size exclusion chromatography (SEC). For the HA , A_2 and the hydrolysis rates all resemble superposing titration curves, while the D remains independent of both the concentration of NaOH, and the contraction of . The indication is that the interactions, conformations and the hydrolysis rates are all controlled by the titration of the HA hydroxyl groups by the NaOH to yield -O ^-, which (i) destroys single strand hydrogen bonds, leading to de-stiffening and contraction of the HA coil and a large decrease in intermolecular interaction, and (ii) slowly depolymerizes HA. The experimental results of HA

  4. Light scattering study of zinc oxide nanoparticles for the application of its anti-bacterial property

    Directory of Open Access Journals (Sweden)

    S. Roy


    Full Text Available Investigations on the anti-bacterial activity of ZnO nanoparticles on Staphylococcus aureus were made by using bio-technical method. Light scattering properties of these particles were studied as a function of scattering angle by using a versatile laboratory light scattering setup in order to find the scattering profile of ZnO nanoparticles and also the mode of action of these particles on bacterial property.

  5. Characterization of aniosotropic nano-particles by using depolarized dynamic light scattering in the near field

    NARCIS (Netherlands)

    Brogioli, D.; Salerno, D.; Cassina, V.; Sacanna, S.|info:eu-repo/dai/nl/311471676; Philipse, A.P.|info:eu-repo/dai/nl/073532894; Croccolo, F.; Mantegazza, F.


    Light scattering techniques are widely used in many fields of condensed and soft matter physics. Usually these methods are based on the study of the scattered light in the far field. Recently, a new family of near field detection schemes has been developed, mainly for the study of small angle light

  6. Light scattering by planetary-regolith analog samples: computational results (United States)

    Väisänen, Timo; Markkanen, Johannes; Hadamcik, Edith; Levasseur-Regourd, Anny-Chantal; Lasue, Jeremie; Blum, Jürgen; Penttilä, Antti; Muinonen, Karri


    We compute light scattering by a planetary-regolith analog surface. The corresponding experimental work is from Hadamcik et al. [1] with the PROGRA2-surf [2] device measuring the polarization of dust particles. The analog samples are low density (volume fraction 0.15 ± 0.03) agglomerates produced by random ballistic deposition of almost equisized silica spheres (refractive index n=1.5 and diameter 1.45 ± 0.06 µm). Computations are carried out with the recently developed codes entitled Radiative Transfer with Reciprocal Transactions (R2T2) and Radiative Transfer Coherent Backscattering with incoherent interactions (RT-CB-ic). Both codes incorporate the so-called incoherent treatment which enhances the applicability of the radiative transfer as shown by Muinonen et al. [3]. As a preliminary result, we have computed scattering from a large spherical medium with the RT-CB-ic using equal-sized particles with diameters of 1.45 microns. The preliminary results have shown that the qualitative characteristics are similar for the computed and measured intensity and polarization curves but that there are still deviations between the characteristics. We plan to remove the deviations by incorporating a size distribution of particles (1.45 ± 0.02 microns) and detailed information about the volume density profile within the analog surface. Acknowledgments: We acknowledge the ERC Advanced Grant no. 320773 entitled Scattering and Absorption of Electromagnetic Waves in Particulate Media (SAEMPL). Computational resources were provided by CSC - IT Centre for Science Ltd, Finland. References: [1] Hadamcik E. et al. (2007), JQSRT, 106, 74-89 [2] Levasseur-Regourd A.C. et al. (2015), Polarimetry of stars and planetary systems, CUP, 61-80 [3] Muinonen K. et al. (2016), extended abstract for EMTS.

  7. Fractal analysis of photoinduced light-scattering patterns in stoichiometric LiNbO3 crystals (United States)

    Sidorov, N. V.; Manukovskaya, D. V.; Palatnikov, M. N.


    We have analyzed the fractal dimension of photoinduced light-scattering patterns in stoichiometric lithium niobate single crystals of different genesis and, based on this analysis, we have investigated the dynamics of manifestation of laser-induced defects in different layers of the photoinduced light-scattering pattern in these crystals. Energy transfer between photoinduced light-scattering layers has been revealed. We have shown that, as distinct from the method of investigation of the photoinduced light scattering by measuring the time dynamics of the opening angle of the indicatrix of the speckle structure of the photoinduced light scattering, the investigation of the time dynamics of the fractal dimension of different layers of the photoinduced light-scattering pattern makes it possible to register particular features of time changes of the order of laser-induced defects in the crystal.

  8. Dielectric and metal target identification based on polarized light scattering analysis: a numerical study (United States)

    Yan, Zhen-Gang; Sun, Weiping; Ren, Meng; Lv, Hongpeng; Li, Jie; Xue, Liang; Yan, Keding; Wang, Shouyu


    In order to quantitatively analyze scattering from two dimensional randomly rough Gaussian surfaces, Kirchhoff approximation method is adopted in numerical calculation for analyzing full angular Stokes vectors of light scattering. With studying both the p- and s-polarized scattering fields from various materials such as metals and dielectrics, it is found that V components of scattering light from metals and dielectrics are different. Via analytical calculation according to slope probability density, the V component difference is attributed to refractive index of materials. Both numerical and analytical calculations prove the V component difference in light scattering can act as a criterion for metal and dielectric identification.

  9. Light Scattering By Nonspherical Particles: Current Status and Challenging Issues (United States)

    Mishchenko, Michael; Hansen, James E. (Technical Monitor)


    Quantitative analyses of remote sensing measurements of aerosols, clouds, precipitation, and particulate surfaces as well as computations of the Earth's radiation balance require detailed understanding of the interaction of small particles with light and other electromagnetic radiation. The convenient availability of the Lorenz-Mie theory has led to a widespread practice of treating all particles as if they were spheres. However, many natural and anthropogenic particles have nonspherical shapes, and the accumulated knowledge suggests that their scattering and radiative properties can be dramatically different from those of equivalent spheres. This presentation will summarize the recent significant progress achieved in the area of electromagnetic scattering by nonspherical particles and outline major problems that still await solution. The talk will cover the following specific topics: (1) comparison of most widely used exact and approximate theoretical techniques; (2) outline of laboratory and field measurement techniques; (3) compare theory and experiment; (4) need for a statistical approach in dealing with natural particles; (5) remote sensing and radiative transfer applications; and (6) major unsolved problems.

  10. Light scattering by lunar-like particle size distributions (United States)

    Goguen, Jay D.


    A fundamental input to models of light scattering from planetary regoliths is the mean phase function of the regolith particles. Using the known size distribution for typical lunar soils, the mean phase function and mean linear polarization for a regolith volume element of spherical particles of any composition were calculated from Mie theory. The two contour plots given here summarize the changes in the mean phase function and linear polarization with changes in the real part of the complex index of refraction, n - ik, for k equals 0.01, the visible wavelength 0.55 micrometers, and the particle size distribution of the typical mature lunar soil 72141. A second figure is a similar index-phase surface, except with k equals 0.1. The index-phase surfaces from this survey are a first order description of scattering by lunar-like regoliths of spherical particles of arbitrary composition. They form the basis of functions that span a large range of parameter-space.

  11. 2D Static Light Scattering for Dairy Based Applications

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke

    are evaluated and discussed. There is a major emphasis on using 2DSLS to discriminate between different protein microstructures in yogurt products. This potentially allows for process control, in relation to microstructure, during yogurt manufacture. As microstructure is critical for consumer acceptability......, this specific process control can be highly beneficial. To provide suitable reference measures on the actual microstructure, we investigate how to quantify micrographs of yogurts objectively. We provide a comparative study, that includes a broad range of different image texture descriptors.......Throughout this thesis we investigate a recently introduced optical technique denoted 2D static light scattering (2DSLS). The technique is remote sensing, non-invasive, highly flexible, and appears to be well suited for in-line process control. Moreover, the output signal contains contributions...

  12. Manipulating scattering of ultracold atoms with light-induced dissipation

    Directory of Open Access Journals (Sweden)

    Mikhail eLemeshko


    Full Text Available Recently it has been shown that pairs of atoms can form metastable bonds due to non-conservative forces induced by dissipation [Lemeshko&Weimer, Nature Comm. textbf{4}, 2230 (2013]. Here we study the dynamics of interaction-induced coherent population trapping -- the process responsible for the formation of dissipatively bound molecules. We derive the effective dissipative potentials induced between ultracold atoms by laser light, and study the time evolution of the scattering states. We demonstrate that binding occurs on short timescales of $sim10~mu$s, even if the initial kinetic energy of the atoms significantly exceeds the depth of the dissipative potential. Dissipatively-bound molecules with preordained bond lengths and vibrational wavefunctions can be created and detected in current experiments with ultracold atoms.

  13. Diffusing-wave spectroscopy in a standard dynamic light scattering setup (United States)

    Fahimi, Zahra; Aangenendt, Frank J.; Voudouris, Panayiotis; Mattsson, Johan; Wyss, Hans M.


    Diffusing-wave spectroscopy (DWS) extends dynamic light scattering measurements to samples with strong multiple scattering. DWS treats the transport of photons through turbid samples as a diffusion process, thereby making it possible to extract the dynamics of scatterers from measured correlation functions. The analysis of DWS data requires knowledge of the path length distribution of photons traveling through the sample. While for flat sample cells this path length distribution can be readily calculated and expressed in analytical form; no such expression is available for cylindrical sample cells. DWS measurements have therefore typically relied on dedicated setups that use flat sample cells. Here we show how DWS measurements, in particular DWS-based microrheology measurements, can be performed in standard dynamic light scattering setups that use cylindrical sample cells. To do so we perform simple random-walk simulations that yield numerical predictions of the path length distribution as a function of both the transport mean free path and the detection angle. This information is used in experiments to extract the mean-square displacement of tracer particles in the material, as well as the corresponding frequency-dependent viscoelastic response. An important advantage of our approach is that by performing measurements at different detection angles, the average path length through the sample can be varied. For measurements performed on a single sample cell, this gives access to a wider range of length and time scales than obtained in a conventional DWS setup. Such angle-dependent measurements also offer an important consistency check, as for all detection angles the DWS analysis should yield the same tracer dynamics, even though the respective path length distributions are very different. We validate our approach by performing measurements both on aqueous suspensions of tracer particles and on solidlike gelatin samples, for which we find our DWS-based microrheology

  14. Light-scattering signal may indicate critical time zone to rescue brain tissue after hypoxia (United States)

    Kawauchi, Satoko; Sato, Shunichi; Uozumi, Yoichi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto


    A light-scattering signal, which is sensitive to cellular/subcellular structural integrity, is a potential indicator of brain tissue viability because metabolic energy is used in part to maintain the structure of cells. We previously observed a unique triphasic scattering change (TSC) at a certain time after oxygen/glucose deprivation for blood-free rat brains; TSC almost coincided with the cerebral adenosine triphosphate (ATP) depletion. We examine whether such TSC can be observed in the presence of blood in vivo, for which transcranial diffuse reflectance measurement is performed for rat brains during hypoxia induced by nitrogen gas inhalation. At a certain time after hypoxia, diffuse reflectance intensity in the near-infrared region changes in three phases, which is shown by spectroscopic analysis to be due to scattering change in the tissue. During hypoxia, rats are reoxygenated at various time points. When the oxygen supply is started before TSC, all rats survive, whereas no rats survive when the oxygen supply is started after TSC. Survival is probabilistic when the oxygen supply is started during TSC, indicating that the period of TSC can be regarded as a critical time zone for rescuing the brain. The results demonstrate that light scattering signal can be an indicator of brain tissue reversibility.

  15. Evaluation of anemia diagnosis based on elastic light scattering (Conference Presentation) (United States)

    Tong, Lieshu; Wang, Xinrui; Xie, Dengling; Chen, Xiaoya; Chu, Kaiqin; Dou, Hu; Smith, Zachary J.


    Currently, one-third of humanity is still suffering from anemia. In China the most common forms of anemia are iron deficiency and Thalassemia minor. Differentiating these two is the key to effective treatment. Iron deficiency is caused by malnutrition and can be cured by iron supplementation. Thalassemia is a hereditary disease in which the hemoglobin β chain is lowered or absent. Iron therapy is not effective, and there is evidence that iron therapy may be harmful to patients with Thalassemia. Both anemias can be diagnosed using red blood cell morphology: Iron deficiency presents a smaller mean cell volume compared to normal cells, but with a wide distribution; Thalassemia, meanwhile, presents a very small cell size and tight particle size distribution. Several researchers have proposed diagnostic indices based on red cell morphology to differentiate these two diseases. However, these indices lack sensitivity and specificity and are constructed without statistical rigor. Using multivariate methods we demonstrate a new classification method based on red cell morphology that diagnoses anemia in a Chinese population with enough accuracy for its use as a screening method. We further demonstrate a low cost instrument that precisely measures red cell morphology using elastic light scattering. This instrument is combined with an automated analysis program that processes scattering data to report red cell morphology without the need for user intervention. Despite using consumer-grade components, when comparing our experimental results with gold-standard measurements, the device can still achieve the high precision required for sensing clinically significant changes in red cell morphology.

  16. TURBISCAN MA 2000: multiple light scattering measurement for concentrated emulsion and suspension instability analysis. (United States)

    Mengual, O; Meunier, G; Cayré, I; Puech, K; Snabre, P


    Emulsion or suspension destabilisation often results from coalescence or particle aggregation (flocculation) leading to particle migration (creaming or sedimentation). Creaming and sedimentation are often considered as reversible, while coalescence and flocculation spell disaster for the formulator. Thus, it is of prime importance to detect coalescence or cluster formation at an early stage to shorten the ageing tests and to improve the formulations. This work mainly concerns the independent and anisotropic scattering of light from an emulsion or suspension in a cylindrical glass measurement cell, in relation with the optical analyser TURBISCAN MA 2000. The propagation of light through a concentrated dispersion can be used to characterise the system physico-chemical stability. Indeed, photons undergo many scattering events in an optically thick dispersion before escaping the medium and entering a receiver aperture. Multiple scattering thus contributes significantly to the transmitted and backscattered flux measured by TURBISCAN MA 2000. We present statistical models and numerical simulations for the radiative transfer in a suspension (plane or cylindrical measurement cells) only involving the photon mean path length, the asymmetry factor and the geometry of the light receivers. We further have developed an imaging method with high grey level resolution for the visualisation and the analysis of the surface flux in the backscattered spot light. We compare the results from physical models and numerical simulations with the experiments performed with the imaging method and the optical analyser TURBISCAN MA 2000 for latex beads suspensions (variable size and particle volume fraction). We then present a few examples of concentrated emulsion and suspension instability analysis with TURBISCAN 2000. It is shown that the instrument is able to characterise particle or aggregate size variation and particle/aggregate migration and to detect these phenomena much more earlier

  17. Spatial quantum correlations induced by random multiple scattering of quadrature squeezed light

    DEFF Research Database (Denmark)

    Lodahl, Peter


    The authors demonstrates that spatial quantum correlations are induced by multiple scattering of quadrature squeezed light through a random medium. As a consequence, light scattered along two different directions by the random medium will not be independent, but be correlated to an extent that ca...... only be described by a quantum mechanical theory for multiple scattering. The spatial quantum correlation is revealed in the fluctuations of the total intensity transmission or reflection through the multiple scattering medium.......The authors demonstrates that spatial quantum correlations are induced by multiple scattering of quadrature squeezed light through a random medium. As a consequence, light scattered along two different directions by the random medium will not be independent, but be correlated to an extent that can...

  18. Measurements of strong correlations in the transport of light through strongly scattering materials

    NARCIS (Netherlands)

    Akbulut, D.


    In this thesis, we study light transport through multiple scattering random photonic materials. Light incident on such materials undergoes many scattering events before exiting the material. The relation between the incident and the transmitted fields is determined by the optical transmission matrix

  19. Discrimination of human cytotoxic lymphocytes from regulatory and B-lymphocytes by orthogonal light scattering

    NARCIS (Netherlands)

    Terstappen, Leonardus Wendelinus Mathias Marie; de Grooth, B.G.; ten Napel, C.H.H.; van Berkel, W.; Greve, Jan


    Light scattering properties of human lymphocyte subpopulations selected by immunofluorescence were studied with a flow cytometer. Regulatory and B-lymphocytes showed a low orthogonal light scatter signal, whereas cytotoxic lymphocytes identified with leu-7, leu-11 and leu-15 revealed a large

  20. Numerical analysis of space-weathering effects on light scattering by asteroid surfaces (United States)

    Markkanen, J.; Martikainen, J.; Penttilä, A.; Muinonen, K.


    We have developed a novel radiative transfer (RT) / geometric optics (GO) numerical approach which allows us to model space-weathering effects on light scattering by planetary surfaces. Our analysis show that the space weathering has a major impact on light-scattering features of asteroids at the visible wavelengths.

  1. The polarization of light scattered by small particles: a personal review

    NARCIS (Netherlands)

    Hovenier, J.W.


    A personal review of the author's field of research is presented at the occasion of his receipt of the first Van de Hulst Light-Scattering Award. Special attention is given to the relation between the author's work and the contributions of Professor H.C. van de Hulst to the field of light scattering

  2. A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

    NARCIS (Netherlands)

    Bruining, J.; Fijnaut, H.M.

    We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due

  3. Optical evaluation of Fricke xylenol orange gel by light scattered at 90 degrees

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, J; Alwan, R; Guermeur, F; Makovicka, L; Bailly, Y [IRMA/ENISYS/FEMTO-ST UMR 6174 CNRS, Universite de Franche-Comte, Pole Universitaire, BP 71427, 25211 Montbeliard Cedex (France); Spevacek, V; Cechak, T [Department of Dosimetry and Application of Ionizing Radiation, FNSPE, Czech Technical University in Prague, Brehova 7, Praha 1, 115 19 (Czech Republic); Martin, E [Department of Radiotherapy, CH Belfort-Montbeliard, 25209 Montbeliard (France)], E-mail:


    This communication presents optical method for evaluation of Fricke xylenol gel (FXG) using light scattered at 90 degrees to initial direction. Although Fricke gel is predominantly absorbing, gelatine matrix scatters enough light which could be collected and related to dose delivered to gel. Initials experiments were oriented to determination applicability of this approach.

  4. Light transfer in agar immobilized microalgae cell cultures (United States)

    Kandilian, Razmig; Jesus, Bruno; Legrand, Jack; Pilon, Laurent; Pruvost, Jérémy


    This paper experimentally and theoretically investigates light transfer in agar-immobilized cell cultures. Certain biotechnological applications such as production of metabolites secreted by photosynthetic microorganisms require cells to be immobilized in biopolymers to minimize contamination and to facilitate metabolite recovery. In such applications, light absorption by cells is one of the most important parameters affecting cell growth or metabolite productivity. Modeling light transfer therein can aid design and optimize immobilized-cell reactors. In this study, Parachlorella kessleri cells with areal biomass concentrations ranging from 0.36 to 16.9 g/m2 were immobilized in 2.6 mm thick agar gels. The average absorption and scattering cross-sections as well as the scattering phase function of P. kessleri cells were measured. Then, the absorption and transport scattering coefficients of the agar gel were determined using an inverse method based on the modified two-flux approximation. The forward model was used to predict the normal-hemispherical transmittance and reflectance of the immobilized-cell films accounting for absorption and scattering by both microalgae and the agar gel. Good agreement was found between the measured and predicted normal-hemispherical transmittance and reflectance provided absorption and scattering by agar were taken into account. Moreover, good agreement was found between experimentally measured and predicted mean rate of photon absorption. Finally, optimal areal biomass concentration was determined to achieve complete absorption of the incident radiation.


    Directory of Open Access Journals (Sweden)



    Full Text Available Anharmonic phonon contributions to Raman scattering in locally anharmonic crystal systems in the framework of the pseudospin-electron model with tunneling splitting of levels are investigated. The case of strong pseudospin-electron coupling is considered. Pseudospin and electron contributions to scattering are taken into account. Frequency dependences of Raman scattering intensity for different values of model parameters and for different polarization of scattering and incident light are investigated.

  6. Chemotaxis in Dictyostelium discoideum : Effect of Concanavalin A on Chemoattractant Mediated Cyclic GMP Accumulation and Light Scattering Decrease

    NARCIS (Netherlands)

    Mato, José M.; Haastert, Peter J.M. van; Krens, Frans A.; Konijn, Theo M.


    In cells of the cellular slime mold Dictyostelium discoideum concanavalin A (Con A), at a concentration of 100 µg per ml, inhibits folic acid and cyclic AMP induced decrease in light scattering. Con A has no effect on folic acid mediated cyclic GMP accumulation and increases cyclic AMP mediated

  7. Study of light scattering using C-Quant® in patients with Fuchs' endothelial dystrophy: A pilot study. (United States)

    Castaño-Martín, B; Gros-Otero, J; Martínez, J; Teus, M


    The purpose of this study was to determine the light scattering in patients with Fuchs' endothelial dystrophy without clinically significant corneal oedema, and evaluate its relationship with endothelial cell count, corneal thickness, and corneal biomechanical parameters. The values of light scattering were measured by C-Quant® (Oculus Optikgeräte GmbH, Germany) in 32 eyes of 17 patients diagnosed with Fuchs' endothelial dystrophy without clinically significant corneal oedema. Corneal biomechanical properties were determined using ORA (ocular response) and Corvis ST® (tonometry). A light scattering value outside the normal range was observed in 93.8% of eyes studied. No statistically significant association (P>.05) was found between the values of the measured light scattering by C-Quant® and endothelial count, pachymetry, or corneal biomechanical properties. In this study, changes were found in the values of light scattering values of patients with corneal Fuchs' endothelial dystrophy. This change does not appear to correlate significantly with disease severity. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Portable bacterial identification system based on elastic light scatter patterns. (United States)

    Bae, Euiwon; Ying, Dawei; Kramer, Donald; Patsekin, Valery; Rajwa, Bartek; Holdman, Cheryl; Sturgis, Jennifer; Davisson, V Jo; Robinson, J Paul


    Conventional diagnosis and identification of bacteria requires shipment of samples to a laboratory for genetic and biochemical analysis. This process can take days and imposes significant delay to action in situations where timely intervention can save lives and reduce associated costs. To enable faster response to an outbreak, a low-cost, small-footprint, portable microbial-identification instrument using forward scatterometry has been developed. This device, weighing 9 lb and measuring 12 × 6 × 10.5 in., utilizes elastic light scatter (ELS) patterns to accurately capture bacterial colony characteristics and delivers the classification results via wireless access. The overall system consists of two CCD cameras, one rotational and one translational stage, and a 635-nm laser diode. Various software algorithms such as Hough transform, 2-D geometric moments, and the traveling salesman problem (TSP) have been implemented to provide colony count and circularity, centering process, and minimized travel time among colonies. Experiments were conducted with four bacteria genera using pure and mixed plate and as proof of principle a field test was conducted in four different locations where the average classification rate ranged between 95 and 100%.

  9. Portable bacterial identification system based on elastic light scatter patterns

    Directory of Open Access Journals (Sweden)

    Bae Euiwon


    Full Text Available Abstract Background Conventional diagnosis and identification of bacteria requires shipment of samples to a laboratory for genetic and biochemical analysis. This process can take days and imposes significant delay to action in situations where timely intervention can save lives and reduce associated costs. To enable faster response to an outbreak, a low-cost, small-footprint, portable microbial-identification instrument using forward scatterometry has been developed. Results This device, weighing 9 lb and measuring 12 × 6 × 10.5 in., utilizes elastic light scatter (ELS patterns to accurately capture bacterial colony characteristics and delivers the classification results via wireless access. The overall system consists of two CCD cameras, one rotational and one translational stage, and a 635-nm laser diode. Various software algorithms such as Hough transform, 2-D geometric moments, and the traveling salesman problem (TSP have been implemented to provide colony count and circularity, centering process, and minimized travel time among colonies. Conclusions Experiments were conducted with four bacteria genera using pure and mixed plate and as proof of principle a field test was conducted in four different locations where the average classification rate ranged between 95 and 100%.

  10. Physiological and pathological clinical conditions and light scattering in brain (United States)

    Kurata, Tsuyoshi; Iwata, Sachiko; Tsuda, Kennosuke; Kinoshita, Masahiro; Saikusa, Mamoru; Hara, Naoko; Oda, Motoki; Ohmae, Etsuko; Araki, Yuko; Sugioka, Takashi; Takashima, Sachio; Iwata, Osuke


    MRI of preterm infants at term commonly reveals subtle brain lesions such as diffuse white matter injury, which are linked with later cognitive impairments. The timing and mechanism of such injury remains unclear. The reduced scattering coefficient of near-infrared light (μs’) has been shown to correlate linearly with gestational age in neonates. To identify clinical variables associated with brain μs’, 60 preterm and full-term infants were studied within 7 days of birth. Dependence of μs’ obtained from the frontal head on clinical variables was assessed. In the univariate analysis, smaller μs’ was associated with antenatal glucocorticoid, emergency Caesarean section, requirement for mechanical ventilation, smaller gestational age, smaller body sizes, low 1- and 5-minute Apgar scores, higher cord blood pH and PO2, and higher blood HCO3- at the time of study. Multivariate analysis revealed that smaller gestational age, requirement for mechanical ventilation, and higher HCO3- at the time of study were correlated with smaller μs’. Brain μs’ depended on variables associated with physiological maturation and pathological conditions of the brain. Further longitudinal studies may help identify pathological events and clinical conditions responsible for subtle brain injury and subsequent cognitive impairments following preterm birth.

  11. Light scattering studies of irradiated {kappa}- and {iota}-carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan) and Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines)]. E-mail:; Nasimova, I.R. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Physics Department, Moscow State University, Moscow 119992 (Russian Federation); Aranilla, C.T. [Philippine Nuclear Research Institute, Commonwealth Ave., Diliman, Quezon City (Philippines); Shibayama, M. [Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, 106-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan)]. E-mail:


    The relationships between the molecular weight (Mw) and the characteristic decay time distribution function G({gamma}) of irradiated kappa ({kappa}-) and iota ({iota}-) carrageenan were studied by static and dynamic light scattering (DLS). Mw and the characteristic decay time ({gamma}{sup -1}) are both steep decreasing exponential function with radiation dose. The dynamic behavior of irradiated {iota}-carrageenan was compared to irradiated {kappa}-carrageenan by DLS. The intensity correlation function of both carrageenans shifted towards shorter relaxation times with increasing radiation dose. Irradiated {iota}-carrageenan like {kappa}-carrageenan exhibits power law behavior at 0-50 kGy (at 0.05-0.1M KCl) indicating similar gelation behaviors. The temperature at which transition from coil to helix takes place (conformational transition temperature) decreases with increasing irradiation dose. A new faster relaxation mode appears at around 0.1-1 ms for both carrageenans between 100 and 150 kGy. Maximum peak height for this mode is at 100 kGy which corresponds to the optimum biological activity of {kappa}- and {iota}-carrageenan.

  12. Validation of in-line surface characterization by light scattering in Robot Assisted Polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo


    The suitability of a commercial scattered light sensor for in-line characterization of fine surfaces in the roughness range Sa 1 – 30 nm generated by the Robot Assisted Polishing (RAP) was investigated and validated. A number of surfaces were generated and directly measured with the scattered light...... sensor on the machine in a shop floor environment. Scattered light roughness measurements of the whole surfaces were performed to investigate the measurement method suitability for 100% quality control. For comparison, the surfaces were measured with reference optical instruments in laboratory conditions....... Comparison of the scattered light measurements results taken on the machine with the reference optical roughness measurements taken in laboratory demonstrate the capability of the scattered light sensor for robust in-line surface characterization. This allows for the RAP process control by proper process...

  13. Changes in the spectrum of light scattered from a rough dielectric film on a metal surface (United States)

    Gu, Zu-Han


    Theoretical calculations have shown that in order to obtain changes in the spectrum of light scattered from a randomly rough surface that are large enough to be observed experimentally, this spectrum should be measured at angles of scattering in the near vicinity of features in the scattering pattern whose angular positions depend strongly on the frequency of the incident light. A scattering system that possessses such features is a dielectric film deposited on the planar surface of a reflecting substrate whose illuminated surface is a 2D randomly rough surface. When the dielectric surface is weakly rough, coherent light scattered from this system consists of speckle spots that arrange themselves into concentric interference rings, called Selenyi rings, centered at the normal to the mean surfaces. The angular positions of these rings (intensity maxima) are independent of the angle of incidence of the incident light. When the dielectric surface is strongly rough the angular positions of these rings now depend on the angle of incidence, and they are called Quetelet rings. The angular positions of both types of rings depend strongly on the wavelength of the incident light. Therefore, the spectrum of the scattered light, measured at a scattering angle close to the position of one of these rings, can differ significantly from that of the incident light. In this paper we study experimentally the scattering of light from the system just described, namely a dielectric film deposited on the planar surface of a metallic substrate, when the illuminated surface of the film is a 2D randomly rough surface. We find large changes in the spectrum of the scattered light at scattering angles in the neighborhood of the fringes in the scattering pattern to which this system gives rise.

  14. Parametric study of ionomer dispersions in catalyst inks by dynamic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Le Marquand, P.; Xie, Z.; Peron, J.; Navessin, T.; Holdcroft, S. [National Research Council of Canada, Vancouver, BC (Canada). Inst. for Fuel Cell Innovation


    This study investigated the effects of ink formulation and preparation on the particle size distribution (PSD) of proton exchange membrane fuel cell (PEMFC) membrane exchange assemblies (MEA). The physical and structural characteristics of different ink types were evaluated in relation to various deposition methods and MEA microstructure and performance. Model systems of an ionomer and dispersing solvent were investigated. PSDs were measured using a dynamic light scattering instrument with a backscattering angle of 173 degrees. The filtration, ionomer concentration, and solvent proportions of binary dispersants were discussed. Single solvent systems with different structures, functional groups and dielectric strengths were also investigated. PSD analyses of Nafion and SPEEK catalyst inks were also conducted.

  15. On stimulated scattering of laser light in inertial fusion energy targets

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, Lj [National Inst. for Fusion Science, The Graduate Univ. for Advanced Studies, Toki, Gifu (Japan); Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Ishiguro, S. [National Inst. for Fusion Science, Theory and Computer Simulation Center, Toki, Gifu (Japan); Sato, T. [JAMSTEC, Earth Simulator Center, Yokohama, Kanagawa (Japan)


    Propagation of a laser light through regions of an underdense plasma is an active research topic in laser fusion. In particular, a large effort has been invested in studies of stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) which can reflect laser energy and produce energetic particles to preheat a fusion energy target. Experiments, theory and simulations agree on a complex interplay between various laser-plasma instabilities. By particle-in-cell simulations of an underdense electron-plasma, we have found, apart from the standard SRS, a strong backscattering near the electron plasma frequency at densities beyond the quarter critical. This novel instability, recognized in recent experiments as stimulated laser scattering on a trapped electron-acoustic mode (SEAS), is absent from a classical theory of laser-parametric instabilities. A parametric excitation of SEAS instability, is explained by a three-wave resonant decay of the incident laser light into a standing backscattered wave and a slow trapped electron acoustic wave ({omega} < {omega}{sub p}). Large SEAS pulsations, eventually suppressed by relativistic heating of electrons, are observed in our simulations. This phenomenon seems relevant to future hohlraum target and fast ignition experiments. (author)

  16. Photovoltaic cell with light trapping for enhanced efficiency (United States)

    Brener, Igal; Fofang, Nche Tumasang; Luk, Ting S.


    The efficiency of a photovoltaic cell is enhanced by light trapping using Mie-scattering nanostructures. In one embodiment, an array of nanocylinders is formed on the front surface of a silicon film to enhance forward scattering into the film, and an array of nanocylinders is formed on the back surface to enhance backscattering so that more light is absorbed within the silicon film. In an alternate embodiment, a mirror layer is formed on the back surface of the silicon film to reflect light within the film back toward the front-surface nanocylinder array.

  17. Rational design of Raman-labeled nanoparticles for a dual-modality, light scattering immunoassay on a polystyrene substrate. (United States)

    Israelsen, Nathan D; Wooley, Donald; Hanson, Cynthia; Vargis, Elizabeth


    Surface-enhanced Raman scattering (SERS) is a powerful light scattering technique that can be used for sensitive immunoassay development and cell labeling. A major obstacle to using SERS is the complexity of fabricating SERS probes since they require nanoscale characterization and optical uniformity. The light scattering response of SERS probes may also be modulated by the substrate used for SERS analysis. A typical SERS substrate such as quartz can be expensive. Polystyrene is a cheaper substrate option but can decrease the SERS response due to interfering Raman emission peaks and high background fluorescence. The goal of this research is to develop an optimized process for fabricating Raman-labeled nanoparticles for a SERS-based immunoassay on a polystyrene substrate. We have developed a method for fabricating SERS nanoparticle probes for use in a light scattering immunoassay on a polystyrene substrate. The light scattering profile of both spherical gold nanoparticle and gold nanorod SERS probes were characterized using Raman spectroscopy and optical absorbance spectroscopy. The effects of substrate interference and autofluorescence were reduced by selecting a Raman reporter with a strong light scattering response in a spectral region where interfering substrate emission peaks are minimized. Both spherical gold nanoparticles and gold nanorods SERS probes used in the immunoassay were detected at labeling concentrations in the low pM range. This analytical sensitivity falls within the typical dynamic range for direct labeling of cell-surface biomarkers using SERS probes. SERS nanoparticle probes were fabricated to produce a strong light scattering signal despite substrate interference. The optical extinction and inelastic light scattering of these probes was detected by optical absorbance spectroscopy and Raman spectroscopy, respectively. This immunoassay demonstrates the feasibility of analyzing strongly enhanced Raman signals on polystyrene, which is an

  18. Light Conversion and Scattering in UV Protective Textiles

    Directory of Open Access Journals (Sweden)

    Grancarić Ana Marija


    Full Text Available The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA, UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm, the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration

  19. Spectroscopic study of light scattering in linear alkylbenzene for liquid scintillator neutrino detectors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiang, E-mail: [Hubei Nuclear Solid Physics Key Laboratory, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan (China); Liu, Qian, E-mail: [School of Physics, University of Chinese Academy of Sciences, 100049, Beijing (China); Han, Junbo [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074, Wuhan (China); Zhang, Zhenyu [Hubei Nuclear Solid Physics Key Laboratory, Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan (China); Zhang, Xuan; Ding, Yayun [Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing (China); Zheng, Yangheng [School of Physics, University of Chinese Academy of Sciences, 100049, Beijing (China); Zhou, Li; Cao, Jun; Wang, Yifang [Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing (China)


    We have set up a light scattering spectrometer to study the depolarization of light scattering in linear alkylbenzene. The scattering spectra show that the depolarized part of light scattering is due to Rayleigh scattering. The additional depolarized Rayleigh scattering can make the effective transparency of linear alkylbenzene much better than expected. Therefore, sufficient scintillation photons can transmit through large liquid scintillator detector, such as that of the JUNO experiment. Our study is crucial to achieving an unprecedented energy resolution of 3 %/√(E(MeV)) required for the JUNO experiment to determine the neutrino mass hierarchy. The spectroscopic method can also be used to examine the depolarization of other organic solvents used in neutrino experiments.

  20. Chiral symmetry and dispersion relations: from $\\pi \\pi$ scattering to hadronic light-by-light.

    CERN Document Server

    CERN. Geneva


    Chiral symmetry provides strong constraints on hadronic matrix elements at low energy, which are most efficiently derived with chiral perturbation theory. As an effective quantum field theory the latter also accounts for rescattering or unitarity effects, albeit only perturbatively, via the loop expansion. In cases where rescattering effects are important it becomes necessary to go beyond the perturbative expansion, e.g. by using dispersion relations. A matching between the chiral and the dispersive representation provides in several cases results of high precision. I will discuss this approach with the help of a few examples, like $\\pi \\pi$ scattering (which has been tested successfully by CERN experiments like NA48/2 and DIRAC), $\\eta \\to 3 \\pi$ and the hadronic light-by-light contribution to $(g-2)_\\mu$. For the latter quantity the implementation of the dispersive approach has opened up the way to a model-independent calculation and the concrete possibility to significantly reduce the theoretical uncertain...

  1. arXiv Light-by-Light Scattering Constraint on Born-Infeld Theory

    CERN Document Server

    Ellis, John; You, Tevong


    The recent measurement by ATLAS of light-by-light scattering in LHC Pb-Pb collisions is the first direct evidence for this basic process. We find that it excludes a range of the mass scale of a nonlinear Born-Infeld extension of QED that is ≲100  GeV, a much stronger constraint than those derived previously. In the case of a Born-Infeld extension of the standard model in which the U(1)Y hypercharge gauge symmetry is realized nonlinearly, the limit on the corresponding mass reach is ∼90  GeV, which, in turn, imposes a lower limit of ≳11  TeV on the magnetic monopole mass in such a U(1)Y Born-Infeld theory.

  2. Observing light-by-light scattering at the Large Hadron Collider. (United States)

    d'Enterria, David; da Silveira, Gustavo G


    Elastic light-by-light scattering (γγ→γγ) is open to study at the Large Hadron Collider thanks to the large quasireal photon fluxes available in electromagnetic interactions of protons (p) and lead (Pb) ions. The γγ→γγ cross sections for diphoton masses m(γγ)>5 GeV amount to 12 fb, 26 pb, and 35 nb in p-p, p-Pb, and Pb-Pb collisions at nucleon-nucleon center-of-mass energies √(s(NN))=14, 8.8, and 5.5 TeV, respectively. Such a measurement has no substantial background in Pb-Pb collisions where one expects about 20 signal events per run, after typical detector acceptance and reconstruction efficiency selections.

  3. Intraocular light scatter, reflections, fluorescence and absorption: what we see in the slit lamp. (United States)

    van den Berg, Thomas J T P


    Much knowledge has been collected over the past 20 years about light scattering in the eye- in particular in the eye lens- and its visual effect, called straylight. It is the purpose of this review to discuss how these insights can be applied to understanding the slit lamp image. The slit lamp image mainly results from back scattering, whereas the effects on vision result mainly from forward scatter. Forward scatter originates from particles of about wavelength size distributed throughout the lens. Most of the slit lamp image originates from small particle scatter (Rayleigh scatter). For a population of middle aged lenses it will be shown that both these scatter components remove around 10% of the light from the direct beam. For slit lamp observation close to the reflection angles, zones of discontinuity (Wasserspalten) at anterior and posterior parts of the lens show up as rough surface reflections. All these light scatter effects increase with age, but the correlations with age, and also between the different components, are weak. For retro-illumination imaging it will be argued that the density or opacity seen in areas of cortical or posterior subcapsular cataract show up because of light scattering, not because of light loss. NOTES: (1) Light scatter must not be confused with aberrations. Light penetrating the eye is divided into two parts: a relatively small part is scattered, and removed from the direct beam. Most of the light is not scattered, but continues as the direct beam. This non-scattered part is the basis for functional imaging, but its quality is under the control of aberrations. Aberrations deflect light mainly over small angles (light scatter is important because of the straylight effects over large angles (>1°), causing problems like glare and hazy vision. (2) The slit lamp image in older lenses and nuclear cataract is strongly influenced by absorption. However, this effect is greatly exaggerated by the light path lengths concerned. This

  4. Light transmittance of 1-piece hydrophobic acrylic intraocular lenses with surface light scattering removed from cadaver eyes. (United States)

    Werner, Liliana; Morris, Caleb; Liu, Erica; Stallings, Shannon; Floyd, Anne; Ollerton, Andrew; Leishman, Lisa; Bodnar, Zachary


    To assess the potential effect of surface light scattering on light transmittance of 1-piece hydrophobic acrylic intraocular lenses (IOLs) with or without a blue-light filter. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Intraocular lenses were obtained from human cadavers (49 IOLs total; 36 with blue-light filter) and from finished-goods inventory (controls). The IOLs were removed from cadaver eyes and the power and model matched to unused controls. After surface proteins were removed, the IOLs were hydrated for 24 hours at room temperature. Surface light scattering was measured with a Scheimpflug camera (EAS-1000 Anterior Segment Analysis System). Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration; RSA-PE-20 integrating sphere). Hydrated scatter values ranged from 4.8 to 202.5 computer-compatible tape (CCT) units for explanted IOLs with blue-light filter and 1.5 to 11.8 CCT units for controls; values ranged from 6.0 to 137.5 CCT units for explanted IOLs without a blue-light filter and 3.5 to 9.6 CCT units for controls. In both groups, there was a tendency toward increasing scatter values with increasing postoperative time. No differences in light transmittance were observed between explanted IOLs and controls in both groups (IOLs with blue-light filter: P=.407; IOL with no blue-light filter: P=.487; both paired t test). Although surface light scattering of explanted IOLs was significantly higher than that of controls and appeared to increase with time, no effect was observed on light transmittance of 1-piece hydrophobic acrylic IOLs with or without a blue-light filter. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Condensation nucleation light scattering detection for capillary electrophoresis. (United States)

    Szostek, B; Koropchak, J A


    We describe two means for interfacing condensation nucleation light scattering detection to capillary electrophoresis (CE). With the first method, a fused-silica capillary was used for the separation and the CE was grounded through a Nafion membrane that also connected the system to a microconcentric pneumatic nebulizer. Limits of detection (LODs) for underivatized amino acids were at the low microgram per milliliter level, and separation efficiencies were ∼9 times lower than the optimum predicted for these species based on the injection plug width and axial dispersion by diffusion. LODs were limited by background nonvolatiles resulting from dissolution of fused silica at the high pHs used for the separations. An alternate system employed PEEK capillaries which acted as the separation capillary and also as the inner nebulizer capillary. In this case, the exit end of the capillary was coated with conductive paint which extended to the tip of the nebulizer, was in contact with the CE buffer, and was grounded to complete the CE circuit. Response was nonlinear and the separation efficiency of this system was somewhat lower than that for the Nafion membrane system. Response as peak heights for all of the amino acids and peptides studied was nearly identical on a mass basis. With this system, much lower background signals were obtained, and as a result, LODs for underivatized amino acids and peptides were below the 1 μg/mL level, corresponding to less than 10 pg or less than 100 fmol injected. Both systems were fairly simple, effective means to generate aerosols with the low flows of CE and should be applicable to interfacing of other aerosol-based detectors with CE.

  6. Review of interferometric spectroscopy of scattered light for the quantification of subdiffractional structure of biomaterials (United States)

    Cherkezyan, Lusik; Zhang, Di; Subramanian, Hariharan; Capoglu, Ilker; Taflove, Allen; Backman, Vadim


    Optical microscopy is the staple technique in the examination of microscale material structure in basic science and applied research. Of particular importance to biology and medical research is the visualization and analysis of the weakly scattering biological cells and tissues. However, the resolution of optical microscopy is limited to ≥200 nm due to the fundamental diffraction limit of light. We review one distinct form of the spectroscopic microscopy (SM) method, which is founded in the analysis of the second-order spectral statistic of a wavelength-dependent bright-field far-zone reflected-light microscope image. This technique offers clear advantages for biomedical research by alleviating two notorious challenges of the optical evaluation of biomaterials: the diffraction limit of light and the lack of sensitivity to biological, optically transparent structures. Addressing the first issue, it has been shown that the spectroscopic content of a bright-field microscope image quantifies structural composition of samples at arbitrarily small length scales, limited by the signal-to-noise ratio of the detector, without necessarily resolving them. Addressing the second issue, SM utilizes a reference arm, sample arm interference scheme, which allows us to elevate the weak scattering signal from biomaterials above the instrument noise floor.

  7. Finite-difference time domain solution of light scattering by arbitrarily shaped particles and surfaces

    DEFF Research Database (Denmark)

    Tanev, Stoyan; Sun, Wenbo


    This chapter reviews the fundamental methods and some of the applications of the three-dimensional (3D) finite-difference time-domain (FDTD) technique for the modeling of light scattering by arbitrarily shaped dielectric particles and surfaces. The emphasis is on the details of the FDTD algorithms...... for particle and surface scattering calculations and the uniaxial perfectly matched layer (UPML) absorbing boundary conditions for truncation of the FDTD grid. We show that the FDTD approach has a significant potential for studying the light scattering by cloud, dust, and biological particles. The applications...... of the FDTD approach for beam scattering by arbitrarily shaped surfaces are also discussed....

  8. Measurements of scattering and absorption in mammalian cell suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, J.R.; Johnson, T.M.; Freyer, J.P.


    During the past several years a range of spectroscopies, including fluorescence and elastic-scatter spectroscopy, have been investigated for optically based detection of cancer and other tissue pathologies. Both elastic-scatter and fluorescence signals depend, in part, on scattering and absorption properties of the cells in the tissue. Therefore an understanding of the scattering and absorption properties of cells is a necessary prerequisite for understanding and developing these techniques. Cell suspensions provide a simple model with which to begin studying the absorption and scattering properties of cells. In this study we have made preliminary measurements of the scattering and absorption properties of suspensions of mouse mammary carcinoma cells (EMT6) over a broad wavelength range (380 nm to 800 nm).

  9. Measurements of scattering and absorption in mammalian cell suspensions (United States)

    Mourant, Judith R.; Freyer, James P.; Johnson, Tamara M.


    During the past several years a range of spectroscopies, including fluorescence and elastic- scatter spectroscopy, have been investigated for optically based detection of cancer and other tissue pathologies. Both elastic-scatter and fluorescence signals depend, in part, on scattering and absorption properties of the cells in the tissue. Therefore an understanding of the scattering and absorption properties of cells is a necessary prerequisite for understanding and developing these techniques. Cell suspensions provide a simple model with which to begin studying the absorption and scattering properties of cells. In this study we have made preliminary measurements of the scattering and absorption properties of suspensions of mouse mammary carcinoma cells (EMT6) over a broad wavelength range (380 nm to 800 nm).

  10. Critical behavior of 2,6-dimethylpyridine-water: Measurements of specific heat, dynamic light scattering, and shear viscosity

    DEFF Research Database (Denmark)

    Mirzaev, S. Z.; Behrends, R.; Heimburg, Thomas Rainer


    2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April......2,6-dimethylpyridine-water, specific heat, dynamic light scattering, shear viscosity Udgivelsesdato: 14 April...

  11. Scattering matrix measurements and light-scattering calculations of calcite particles

    Directory of Open Access Journals (Sweden)

    D. D. Dabrowska


    Full Text Available We present measurements of the complete scattering matrix as a function of the scattering angle of a sample of calcite particles collected near Lecce, Italy. The measurements are done at a wavelength of 647 nm in the scattering angle range 3°−177°. FESEM and SEM images show that the sample consists largely of flake-like particles. Ten different flake-like geometries are randomly generated and their scattering properties are simulated with DDA for sizes from 0.1 μm to 1 μm. Some preliminary comparisons of the simulations and the measurements are shown.

  12. Asymmetrical flow field-flow fractionation with multi-angle light scattering and quasi-elastic light scattering for characterization of polymersomes: comparison with classical techniques. (United States)

    Till, Ugo; Gaucher-Delmas, Mireille; Saint-Aguet, Pascale; Hamon, Glenn; Marty, Jean-Daniel; Chassenieux, Christophe; Payré, Bruno; Goudounèche, Dominique; Mingotaud, Anne-Françoise; Violleau, Frédéric


    Polymersomes formed from amphiphilic block copolymers, such as poly(ethyleneoxide-b-ε-caprolactone) (PEO-b-PCL) or poly(ethyleneoxide-b-methylmethacrylate), were characterized by asymmetrical flow field-flow fractionation coupled with quasi-elastic light scattering (QELS), multi-angle light scattering (MALS), and refractive index detection, leading to the determination of their size, shape, and molecular weight. The method was cross-examined with more classical ones, like batch dynamic and static light scattering, electron microscopy, and atomic force microscopy. The results show good complementarities between all the techniques; asymmetrical flow field-flow fractionation being the most pertinent one when the sample exhibits several different types of population.

  13. Stimulated light emission and inelastic scattering by a classical linear system of rotating particles. (United States)

    Asenjo-Garcia, Ana; Manjavacas, Alejandro; de Abajo, F Javier García


    The rotational dynamics of particles subject to external illumination is found to produce light amplification and inelastic scattering at high rotation velocities. Light emission at frequencies shifted with respect to the incident light by twice the rotation frequency dominates over elastic scattering within a wide range of light and rotation frequencies. Remarkably, net amplification of the incident light is produced in this classical linear system via stimulated emission. Large optically induced acceleration rates are predicted in vacuum accompanied by moderate heating of the particle, thus supporting the possibility of observing these effects under extreme rotation conditions. © 2011 American Physical Society

  14. Condition for far-zone spectral isotropy of an electromagnetic light wave on weak scattering. (United States)

    Wang, Tao; Zhao, Daomu


    The far-zone spectral isotropy of an electromagnetic light wave on scattering has been discussed. It is shown that a sufficient condition for the far-zone spectral isotropy of an electromagnetic light wave on scattering can be expressed by the following two requirements: the two-point correlation function of the dielectric susceptibility of the scattering medium obeys the so-called scaling law, and the normalized spectrum of the incident light wave has the same distribution along the two perpendicular directions.


    The use of White cells (J. V. White . ’Long optical paths at large aperture’, J. Opt. Soc. Am. 32:285 (1942)) as light gatherers is analyzed in this...unobservable. It is evident, therefore, that White cells and the sources used with them must be properly designed and applied to be effective. (Author)

  16. Do epidermal lens cells facilitate the absorptance of diffuse light? (United States)

    Brodersen, Craig R; Vogelmann, Thomas C


    Many understory plants rely on diffuse light for photosynthesis because direct light is usually scattered by upper canopy layers before it strikes the forest floor. There is a considerable gap in the literature concerning the interaction of direct and diffuse light with leaves. Some understory plants have well-developed lens-shaped epidermal cells, which have long been thought to increase the absorption of diffuse light. To assess the role of epidermal cell shape in capturing direct vs. diffuse light, we measured leaf reflectance and transmittance with an integrating sphere system using leaves with flat (Begonia erythrophylla, Citrus reticulata, and Ficus benjamina) and lens-shaped epidermal cells (B. bowerae, Colocasia esculenta, and Impatiens velvetea). In all species examined, more light was absorbed when leaves were irradiated with direct as opposed to diffuse light. When leaves were irradiated with diffuse light, more light was transmitted and more was reflected in both leaf types, resulting in absorptance values 2-3% lower than in leaves irradiated with direct light. These data suggest that lens-shaped epidermal cells do not aid the capture of diffuse light. Palisade and mesophyll cell anatomy and leaf thickness appear to have more influence in the capture and absorption of light than does epidermal cell shape.

  17. The role of meson exchanges in light-by-light scattering (United States)

    Lebiedowicz, Piotr; Szczurek, Antoni


    We discuss the role of meson exchange mechanisms in γγ → γγ scattering. Several pseudoscalar (π0, η, η‧ (958), ηc (1 S), ηc (2 S)), scalar (f0 (500), f0 (980), a0 (980), f0 (1370), χc0 (1 P)) and tensor (f2 (1270), a2 (1320), f2‧ (1525), f2 (1565), a2 (1700)) mesons are taken into account. We consider not only s-channel but also for the first time t- and u-channel meson exchange amplitudes corrected for off-shell effects including vertex form factors. We find that, depending on not well known vertex form factors, the meson exchange amplitudes interfere among themselves and could interfere with fermion-box amplitudes and modify the resulting cross sections. The meson contributions are shown as a function of collision energy as well as angular distributions are presented. Interesting interference effects separately for light pseudoscalar, scalar and tensor meson groups are discussed. The meson exchange contributions may be potentially important in the context of a measurement performed recently in ultraperipheral collisions of heavy ions by the ATLAS collaboration. The light-by-light interactions could be studied in future in electron-positron collisions by the Belle II at SuperKEKB accelerator.

  18. Planet signatures in collisionally active debris discs: scattered light images (United States)

    Thebault, P.; Kral, Q.; Ertel, S.


    Context. Planet perturbations have been often invoked as a potential explanation for many spatial structures that have been imaged in debris discs. So far this issue has been mostly investigated with pure N-body numerical models, which neglect the crucial effect collisions within the disc can have on the disc's response to dynamical perturbations. Aims: We numerically investigate how the coupled effect of collisions and radiation pressure can affect the formation and survival of radial and azimutal structures in a disc perturbed by a planet. We consider two different set-ups: a planet embedded within an extended disc and a planet exterior to an inner debris ring. One important issue we want to address is under which conditions a planet's signature can be observable in a collisionally active disc. Methods: We use our DyCoSS code, which is designed to investigate the structure of perturbed debris discs at dynamical and collisional steady-state, and derive synthetic images of the system in scattered light. The planet's mass and orbit, as well as the disc's collisional activity (parameterized by its average vertical optical depth τ0) are explored as free parameters. Results: We find that collisions always significantly damp planet-induced spatial structures. For the case of an embedded planet, the planet's signature, mostly a density gap around its radial position, should remain detectable in head-on images if Mplanet ≥ MSaturn. If the system is seen edge-on, however, inferring the presence of the planet is much more difficult, as only weak asymmetries remain in a collisionally active disc, although some planet-induced signatures might be observable under very favourable conditions. For the case of an inner ring and an external planet, planetary perturbations cannot prevent collision-produced small fragments from populating the regions beyond the ring. The radial luminosity profile exterior to the ring is in most cases close to the one it should have in the absence

  19. Identifying mitosis deep in tissue using dynamic light scattering fluctuation spectroscopy (United States)

    An, Ran; Jeong, Kwan; Turek, John; Nolte, David


    In the cell cycle, mitosis is the most dramatic phase, especially in Telophase and Cytokinesis. For single cells and cell monolayer, there are precise microscopic studies of mitosis, while for 3-D tissue such as tumor spheroids the light signal is obscured by the high background of diffusely scattered light. Therefore, the mitosis phase cannot be detected deep inside 3-D tissue using conventional microscopic techniques. In this work, we detect mitosis in living tissue using Tissue Dynamic Imaging (TDI). We trace depth-gated dynamic speckles from a tumor spheroid (up to 1mm in diameter) using coherence-gated digital holography imaging. Frequency-versus-time spectrograms depend on specific types of perturbation such as cell shape change, membrane undulation and cell organelles movements. By using these spectral responses as functional finger prints, we can identify mitosis events from different voxels at a specified depth inside tumor spheroids. By performing B-scans of the tumor spheroid, we generate 3-D mitosis maps (or movies) for the entire tumor spheroids. We show that for healthy tumor spheroids, the mitosis events only happen within the proliferating shell. We also compare results when anti-cancer drugs are applied to arrest, release and synchronize mitosis. This shows the application of TDI for drug screening. The technique can identify and monitor complex motilities inside 3-D tissue with a strong potential for drug diagnosis and developmental biology studies.

  20. Multiple scattering of elliptically polarized light in two-dimensional medium with large inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Gorodnichev, E. E., E-mail: [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)


    For elliptically polarized light incident on a two-dimensional medium with large inhomogeneities, the Stokes parameters of scattered waves are calculated. Multiple scattering is assumed to be sharply anisotropic. The degree of polarization of scattered radiation is shown to be a nonmonotonic function of depth when the incident wave is circularly polarized or its polarization vector is not parallel to the symmetry axis of the inhomogeneities.

  1. Whole-field measurement of three-dimensional stress by scattered-light photoelasticity with unpolarized light

    Directory of Open Access Journals (Sweden)

    Kihara T.


    Full Text Available In digital scattered-light photoelasticity with unpolarized light (DSLPUL, secondary principal stress direction ψj and total relative phase retardation ρjtot in a three-dimensional stressed model with rotation of the principal stress axes are obtained by measuring Stokes parameters of scattered light from optical slices. The present paper describes intelligibly the principle of DSLPUL, and then demonstrates that the ψj and ρjtot in a frozen stress sphere model are nondestructively measured over the entire field.

  2. Investigation of light scattering characteristics of individual leukocytes using three-dimensional refractive index maps (United States)

    Sung, Kung-Bin; Lin, Yang-Hsien; Lin, Fong-jheng; Hsieh, Chao-Mao; Wu, Shang-Ju


    Three-dimensional (3D) refractive-index (RI) microscopy is an emerging technique suitable for live-cell imaging due to its label-free and fast 3D imaging capabilities. We have developed a common-path system to acquire 3D RI microscopic images of cells with excellent speed and stability. After obtaining 3D RI distributions of individual leukocytes, we used a 3D finite-difference time-domain tool to study light scattering properties. Backscattering spectra of lymphocytes, monocytes and neutrophils are different from each other. Backscattering spectra of lymphocytes matched well with those of homogeneous spheres as predicted by Mie theory while backscattering spectra of neutrophils are significantly more intense than those of the other two types. This suggests the possibility of classifying the three types of leukocytes based on backscattering.

  3. Dynamic light scattering for the characterization and counting of extracellular vesicles: a powerful noninvasive tool (United States)

    Palmieri, Valentina; Lucchetti, Donatella; Gatto, Ilaria; Maiorana, Alessandro; Marcantoni, Margherita; Maulucci, Giuseppe; Papi, Massimiliano; Pola, Roberto; De Spirito, Marco; Sgambato, Alessandro


    Extracellular vesicles (EVs) are cell-to-cell shuttles that have recently drawn interest both as drug delivery platforms and disease biomarkers. Despite the increasingly recognized relevance of these vesicles, their detection, and characterization still have several technical drawbacks. In this paper, we accurately assess the size distribution and concentration of EVs by using a high-throughput non-perturbative technique such as Dynamic Light Scattering (DLS). The vesicle radii distribution, as further confirmed by Atomic Force Microscopy experiments, ranges from 10 to 80 nm and appears very asymmetric towards larger radii with a main peak at roughly 30 nm. By combining DLS and Bradford assay, we also demonstrate the feasibility of recovering the concentration and its distribution of proteins contained inside vesicles. The sensitivity of our approach allows to detect protein concentrations as low as 0.01 mg/ml.

  4. Why circumstellar disks are so faint in scattered light : the case of HD 100546

    NARCIS (Netherlands)

    Mulders, G. D.; Min, M.; Dominik, C.; Debes, J. H.; Schneider, G.

    Context. Scattered light images of circumstellar disks play an important role in characterizing the planet forming environments around young stars. The characteristic size of the scattering dust grains can be estimated from the observed brightness asymmetry between the near and far side of the disk,

  5. Why circumstellar disks are so faint in scattered light: the case of HD 100546

    NARCIS (Netherlands)

    Mulders, G.D.; Min, M.; Dominik, C.; Debes, J.H.; Schneider, G.


    Context. Scattered light images of circumstellar disks play an important role in characterizing the planet forming environments around young stars. The characteristic size of the scattering dust grains can be estimated from the observed brightness asymmetry between the near and far side of the disk,

  6. Spontaneous Rayleigh-Brillouin scattering of ultraviolet light in nitrogen, dry and moist air

    NARCIS (Netherlands)

    Witschas, B.; Vieitez, M.O.; van Duijn, E.-J.; Reitebuch, O.; Van de Water, W.; Ubachs, W.M.G.


    Atmospheric lidar techniques for the measurement of wind, temperature, and optical properties of aerosols rely on the exact knowledge of the spectral line shape of the scattered laser light on molecules. We report on spontaneous Rayleigh-Brillouin scattering measurements in the ultraviolet at a

  7. Laser light-scattering spectroscopy: a new application in the study of ciliary activity. (United States)

    Lee, W I; Verdugo, P


    A uniquely precise and simple method to study ciliary activity by laser light-scattering spectroscopy has been developed and validated. A concurrent study of the effect of Ca2+ on ciliary activity in vitro by laser scattering spectroscopy and high speed cinematography has demonstrated that this new method is simpler and as accurate and reproducible as the high speed film technique.

  8. Development of a multispectral light-scatter sensor for bacterial colonies (United States)

    We report a multispectral elastic-light-scatter instrument that can simultaneously detect three-wavelength scatter patterns and associated optical densities from individual bacterial colonies, overcoming the limits of the single-wavelength predecessor. Absorption measurements on liquid bacterial sam...

  9. Bio-inspired, colorful, flexible, defrostable light-scattering hybrid films for the effective distribution of LED light. (United States)

    An, Seongpil; Jo, Hong Seok; Kim, Yong Il; Song, Kyo Yong; Kim, Min-Woo; Lee, Kyu Bum; Yarin, Alexander L; Yoon, Sam S


    Bioluminescent jellyfish has a unique structure derived from fiber/polymer interfaces that is advantageous for effective light scattering in the dark, deep sea water. Herein, we demonstrate the fabrication of bio-inspired hybrid films by mimicry of the jellyfish's structure, leading to excellent light-scattering performance and defrosting capability. A haze value reaching 59.3% and a heating temperature of up to 292 °C were achieved with the films. Accordingly, the developed surface constitutes an attractive optical device for lighting applications, especially for street or vehicle luminaries for freezing Arctic-climate countries. The morphological details of the hybrid films were revealed by scanning electron microscopy. The light-scattering properties of these films were examined by ultraviolet-visible-infrared spectrophotometry and anti-glare effect analyses. The defrosting performance of the hybrid films was evaluated via heating tests and infra-red observations.

  10. Comparison of particle size of cracking catalyst determined by laser light scattering and dry sieve methods

    Energy Technology Data Exchange (ETDEWEB)

    Dishman, K.L.; Doolin, P.K.; Hoffman, J.F. (Ashland Petroleum Co., Ashland, KY (United States))


    A method of interconversion of dry sieve and laser light scattering particle size values has been developed for cracking catalysts. Values obtained by light scattering techniques were consistently larger than those obtained by dry sieve analysis. The differences were primarily due to lack of sphericity of the particles. The particle size distribution determined by light scattering techniques was based on an average particle diameter. Conversely, the sieve measured the smallest diameter of the particle which can pass through the opening. Microscopic examination of commercial cracking catalysts confirmed their nonuniformity. The sphericity of the catalyst particles decreased as particle size increased. Therefore, the divergence between the laser light scattering and dry sieving value became greater as the catalyst particle size increased.

  11. Modeling of the Autofluorescence Spectra of the Crystalline Lens with Cataract Taking into Account Light Scattering (United States)

    Shapovalov, K. A.; Salmin, V. V.; Lazarenko, V. I.; Gar‧kavenko, V. V.


    The model of the autofluorescence spectrum formation of a crystalline lens taking into account light scattering was presented. Cross sections of extinction, scattering and absorption were obtained numerically for models of normal crystalline lens and cataract according to the Mie theory for polydisperse systems. To validate the model, data on the autofluorescence spectra of the normal lens and cataracts were obtained using an experimental ophthalmologic spectrofluorometer with excitation by UV light emitting diodes. In the framework of the model, the influence of the lens light scattering on the shape of the luminescence spectrum was estimated. It was found that the changes in the fluorescence spectrum of lenses with cataracts can be completely interpreted by the light scattering.

  12. Neutron and photon (light) scattering on solitons in the quasi-one-dimensional magnetics

    CERN Document Server

    Abdulloev, K O


    The general expression we have found earlier for the dynamics form-factor is used to analyse experiments on the neutron and photon (light) scattering by the gas of solitons in quasi-one-dimensional magnetics (Authors)

  13. Light scattering reviews 7 radiative transfer and optical properties of atmosphere and underlying surface

    CERN Document Server

    Kokhanovsky, Alexander A


    This book describes modern advances in radiative transfer and light scattering. Coverage includes fast radiative transfer techniques, use of polarization in remote sensing and recent developments in remote sensing of snow properties from space observations.

  14. Protein analysis by dynamic light scattering: Methods and techniques for students

    National Research Council Canada - National Science Library

    Lorber, Bernard; Fischer, Frédéric; Bailly, Marc; Roy, Hervé; Kern, Daniel


    Dynamic light scattering (DLS) analyses are routinely used in biology laboratories to detect aggregates in macromolecular solutions, to determine the size of proteins, nucleic acids, and complexes or to monitor the binding of ligands...

  15. Small-angle light scattering by monolayer of liquid crystal droplets in polymer matrix

    Directory of Open Access Journals (Sweden)

    A. V. Konkolovich


    Full Text Available A method for modeling the angular distribution of light scattered by a monolayer of liquid crystal droplets dispersed in polymer matrix is developed. It is based on the anomalous diffraction and interference approximations.

  16. Polarized and depolarized light-scattering studies on Brownian diffusional and critical fluid systems: theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, C.M.


    An effort to expand light-scattering autocorrelation techniques to Brownian diffusional and critical fluid systems in which multiple scattering effects are important, and to understand the observed similarity of the Rayleigh linewidth of light scattered from these two seemingly different systems is discussed. A formalism was developed to find the light field multiply scattered from a suspension of Brownian diffusing particles. For the field doubly scattered from a system of noninteracting Brownian particles, the intensity and correlation time were much less dependent on the scattering angle than for the singly scattered component. The polarized and depolarized correlation times of light scattered from Brownian particle systems were measured. The double-scattering formalism was extended to light scattered from critical fluid systems. In the region k xi greater than 5 the doubly and singly scattered correlation times were nearly equal. The dynamic droplet model of critical phenomena was developed which gives the proper, experimentally verified, forms for the intensity and linewidth of light scattered from a critical fluid. To test the dynamic droplet model and the mode theories Rayleigh linewidth predictions, light-scattering measurements were performed on the critical fluid system methanol and cyclohexane. The data agreed with both the dynamic droplet and decoupled mode theory predictions. The depolarized scattered spectra from a critical fluid were measured, and qualitative agreement with the double-scattering theory was found. 57 figures, 5 tables.

  17. Coupling of light into the fundamental diffusion mode of a scattering medium (Conference Presentation) (United States)

    Ojambati, Oluwafemi S.; Yılmaz, Hasan; Lagendijk, Ad; Mosk, Allard P.; Vos, Willem L.


    Diffusion equation describes the energy density inside a scattering medium such as biological tissues and paint [1]. The solution of the diffusion equation is a sum over a complete set of eigensolutions that shows a characteristic linear decrease with depth in the medium. It is of particular interest if one could launch energy in the fundamental eigensolution, as this opens the opportunity to achieve a much greater internal energy density. For applications in optics, an enhanced energy density is vital for solid-state lighting, light harvesting in solar cells, low-threshold random lasers, and biomedical optics. Here we demonstrate the first ever selective coupling of optical energy into a diffusion eigensolution of a scattering medium of zinc oxide (ZnO) paint. To this end, we exploit wavefront shaping to selectively couple energy into the fundamental diffusion mode, employing fluorescence of nanoparticles randomly positioned inside the medium as a probe of the energy density. We observe an enhanced fluorescence in case of optimized incident wavefronts, and the enhancement increases with sample thickness, a typical mesoscopic control parameter. We interpret successfully our result by invoking the fundamental eigensolution of the diffusion equation, and we obtain excellent agreement with our observations, even in absence of adjustable parameters [2]. References [1] R. Pierrat, P. Ambichl, S. Gigan, A. Haber, R. Carminati, and R. Rotter, Proc. Natl. Acad. Sci. U.S.A. 111, 17765 (2014). [2] O. S. Ojambati, H. Yilmaz, A. Lagendijk, A. P. Mosk, and W. L. Vos, arXiv:1505.08103.

  18. Reflection Matrix Method for Controlling Light After Reflection From a Diffuse Scattering Surface (United States)



  19. The scatter of light of different colour in the atmosphere.

    NARCIS (Netherlands)

    Schreuder, D.A.


    It is often claimed (Devaux) that yellow light is superior to white light for vehicle headlamps. This claim is supported by evidence of a physical, physiological and psychological nature. In most cases, it appears that the advantages of yellow light are small, and can usually be neglected

  20. Longitudinal intensity distribution near the focus produced by light through scattering media (United States)

    Ji, Xuan-Xuan; Wan, Li-Peng; Chen, Zi-Yang; Pu, Ji-Xiong


    Speckle pattern is formed when coherent light passes through scattering media. It has been demonstrated that after appropriately optimizing the phase of the incident light, a bright focal spot in the target point can be obtained for the case that the light passes through the scattering medium. However, until now the focused intensity distribution near the focus seems unclear. In this paper we experimentally investigate some factors influencing the longitudinal intensity distribution near the focus in details. It is shown that the desired longitudinal focused intensity distribution can be obtained by optimizing the incident light. The results may have potential applications in particle manipulation and laser processing, etc.

  1. Spectral bandwidth reduction of Thomson scattered light by pulse chirping

    Directory of Open Access Journals (Sweden)

    Isaac Ghebregziabher


    Full Text Available Based on single particle tracking in the framework of classical Thomson scattering with incoherent superposition, we developed a relativistic, three-dimensional numerical model that calculates and quantifies the characteristics of emitted radiation when a relativistic electron beam interacts with an intense laser pulse. This model has been benchmarked against analytical expressions, based on the plane wave approximation to the laser field, derived by Esarey et al. [Phys. Rev. E 48, 3003 (1993PLEEE81063-651X10.1103/PhysRevE.48.3003]. For laser pulses of sufficient duration, we find that the scattered radiation spectrum is broadened due to interferences arising from the pulsed nature of the laser. We find that by appropriately chirping the scattering laser pulse, spectral broadening can be minimized, and the peak on-axis brightness of the emitted radiation is increased by a factor of approximately 5.

  2. Exploiting breakdown of the similarity relation for diffuse light transport: simultaneous retrieval of scattering anisotropy and diffusion constant (United States)

    Svensson, T.; Savo, R.; Alerstam, E.; Vynck, K.; Burresi, M.; Wiersma, D. S.


    As manifested in the similarity relation of diffuse light transport, it is difficult to assess single scattering characteristics from multiply scattered light. We take advantage of the limited validity of the diffusion approximation of light transport and demonstrate, experimentally and numerically, that even deep into the multiple scattering regime, time-resolved detection of transmitted light allows simultaneous assessment of both single scattering anisotropy and scattering mean free path, and therefore also macroscopic parameters like the diffusion constant and the transport mean free path. This is achieved via careful assessment of early light and matching against Monte Carlo simulations of radiative transfer.

  3. Spectrum of an electromagnetic light wave on scattering from an anisotropic semisoft boundary medium. (United States)

    Wang, Tao; Jiang, Zhenfei; Ji, Xiaoling; Zhao, Daomu


    Spectral shifts and spectral switches of a polychromatic electromagnetic light wave on scattering from an anisotropic semisoft boundary medium are discussed. It is shown that both the property of the incident field and the character of the scattering medium play roles in the change of the spectrum of the far-zone scattered field. It is also shown that the distribution of the far-zone scattered spectrum, including the magnitude of the spectral shift and the direction at which the spectral switch occurs, is rotationally nonsymmetric.

  4. Observation of spatial quantum correlations induced by multiple scattering of nonclassical light

    DEFF Research Database (Denmark)

    Smolka, Stephan; Huck, Alexander; Andersen, Ulrik Lund


    and negative spatial quantum correlations are observed when varying the quantum state incident to the multiple scattering medium, and the strength of the correlations is controlled by the number of photons. The experimental results are in excellent agreement with recent theoretical proposals by implementing...... the full quantum model of multiple scattering.......We present the experimental realization of spatial quantum correlations of photons that are induced by multiple scattering of squeezed light. The quantum correlation relates photons propagating along two different light paths through the random medium and is infinite in range. Both positive...

  5. Nucleon–nucleon scattering in the light of supersymmetric quantum ...

    Indian Academy of Sciences (India)


    May 2, 2014 ... J Bhoi, U Laha and K C Panda interest to generate supersymmetric partners of the latter and study their partner poten- tials, related physical observables etc., which have important applications in quantum scattering theory. Arnold and Mackellar [5] parametrized Hulthen potential to fit the deuteron binding.

  6. Spherically symmetric inhomogeneous bianisotropic media: Wave propagation and light scattering

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Shalin, Alexander S.; Lavrinenko, Andrei


    We develop a technique for finding closed-form expressions for electromagnetic fields in radially inhomogeneous bianisotropic media, both the solutions of the Maxwell equations and material tensors being defined by the set of auxiliary two-dimensional matrices. The approach is applied to determin...... the scattering cross-sections by spherical particles, the fields inside which correspond to the Airy-exponential waves....

  7. Light scattering and random lasing in aqueous suspensions of hexagonal boron nitride nanoflakes (United States)

    O’Brien, S. A.; Harvey, A.; Griffin, A.; Donnelly, T.; Mulcahy, D.; Coleman, J. N.; Donegan, J. F.; McCloskey, D.


    Liquid phase exfoliation allows large scale production of 2D materials in solution. The particles are highly anisotropic and strongly scatter light. While spherical particles can be accurately and precisely described by a single parameter—the radius, 2D nanoflakes, however, cannot be so easily described. We investigate light scattering in aqueous solutions of 2D hexagonal boron nitride nanoflakes in the single and multiple scattering regimes. In the single scattering regime, the anisotropic 2D materials show a much stronger depolarization of light when compared to spherical particles of similar size. In the multiple scattering regime, the scattering as a function of optical path for hexagonal boron nitride nanoflakes of a given lateral length was found to be qualitatively equivalent to scattering from spheres with the same diameter. We also report the presence of random lasing in high concentration suspensions of aqueous h-BN mixed with Rhodamine B dye. The h-BN works as a scattering agent and Rhodamine B as a gain medium for the process. We observed random lasing at 587 nm with a threshold energy of 0.8 mJ.

  8. Experimental demonstration of singular-optical colouring of regularly scattered white light

    DEFF Research Database (Denmark)

    Angelsky, O.V.; Hanson, Steen Grüner; Maksimyak, P.P.


    Experimental interference modelling of the effects of colouring of a beam traversing a light-scattering medium is presented. It is shown that the result of colouring of the beam at the output of the medium depends on the magnitudes of the phase delays of the singly forward scattered partial signals....... The colouring mechanism has for the first time experimentally been illustrated for a forward propagating beam through a light-scattering medium. This is showed in video-fragments of the interferograms recorded within the zero interference fringe with a gradual change of the path difference of the interfering...... polychromatic wave trains. Spectral investigation of the effects of colouring has been carried out using a solution of liquid crystal in a polymer matrix. The amplitude ratio of the non-scattered and the singly forward scattered interfering components significantly affects the colour intensity. It has further...

  9. Comparison of analytical calculations with experimental measurements for polarized light scattering by microorganisms (United States)

    Hull, Patricia G.; Shaw, Felecia G.; Quinby-Hunt, Mary S.; Shapiro, Daniel B.; Hunt, Arlon J.; Leighton, Terrence


    The consequences of light scattering from both spherical and non-spherical particles on the propagation of light in the ocean were investigated. The scattering from an ensemble of non- spherical micro-organisms is calculated using the coupled-dipole approximation with an orientational average over Euler angles using Gauss-Legendre integration. Mie calculations provide rigorous solutions for spherical particles and are considerably less computer intensive than the coupled-dipole approximation. Furthermore, they have been shown to accurately predict the scattering for marine organisms that are nearly spherical. Scattering matrix elements calculated using the coupled-dipole approximation were compared with those obtained using Mie calculations in the limit as an ellipsoidal object approaches a sphere in order to assess the limits of applicability of the Mie theory to ellipsoidal particles. Experimental measurements of the scattering matrix elements for spherical particles (latex spheres) and ellipsoidal particles (Bacillus subtilis) were used to test the validity of our analytical approach.

  10. [Light scattering extinction properties of atmospheric particle and pollution characteristics in hazy weather in Hangzhou]. (United States)

    Xu, Chang; Ye, Hui; Shen, Jian-Dong; Sun, Hong-Liang; Hong, Sheng-Mao; Jiao, Li; Huang, Kan


    In order to evaluate the influence of particle scattering on visibility, light scattering coefficient, particle concentrations and meteorological factor were simultaneously monitored from July 2011 to June 2012 in Hangzhou. Daily scattering coefficients ranged from 108.4 to 1 098.1 Mm(-1), with an annual average concentration of 428.6 Mm(-1) ± 200.2 Mm(-1). Seasonal variation of scattering coefficients was significant, with the highest concentrations observed in autumn and winter and the lowest in summer. It was found there were two peaks for the average diurnal variations of the scattering coefficient, which could be observed at 08:00 and 21:00. The scattering efficiencies of PM2.5 and PM10 were 7.6 m2 x g(-1) and 4.4 m2 x g(-1), respectively. The particle scattering was about 90.2 percent of the total light extinction. The scattering coefficients were 684.4 Mm(-1) ± 218.1 Mm(-1) and 1 095.4 Mm(-1) ± 397.7 Mm(-1) in hazy and heavy hazy days, respectively, which were 2.6 and 4.2 times as high as in non-hazy weather, indicating that particle scattering is the main factor for visibility degradation and the occurrence of hazy weather in Hangzhou.

  11. Label-free identification of individual bacteria using Fourier transform light scattering. (United States)

    Jo, YoungJu; Jung, JaeHwang; Kim, Min-Hyeok; Park, HyunJoo; Kang, Suk-Jo; Park, YongKeun


    Rapid identification of bacterial species is crucial in medicine and food hygiene. In order to achieve rapid and label-free identification of bacterial species at the single bacterium level, we propose and experimentally demonstrate an optical method based on Fourier transform light scattering (FTLS) measurements and statistical classification. For individual rod-shaped bacteria belonging to four bacterial species (Listeria monocytogenes, Escherichia coli, Lactobacillus casei, and Bacillus subtilis), two-dimensional angle-resolved light scattering maps are precisely measured using FTLS technique. The scattering maps are then systematically analyzed, employing statistical classification in order to extract the unique fingerprint patterns for each species, so that a new unidentified bacterium can be identified by a single light scattering measurement. The single-bacterial and label-free nature of our method suggests wide applicability for rapid point-of-care bacterial diagnosis.

  12. Label-free identification of individual bacteria using Fourier transform light scattering

    CERN Document Server

    Jo, YoungJu; Kim, Min-hyeok; Park, HyunJoo; Kang, Suk-Jo; Park, YongKeun


    Rapid identification of bacterial species is crucial in medicine and food hygiene. In order to achieve rapid and label-free identification of bacterial species at the single bacterium level, we propose and experimentally demonstrate an optical method based on Fourier transform light scattering (FTLS) measurements and statistical classification. For individual rod-shaped bacteria belonging to four bacterial species (Listeria monocytogenes, Escherichia coli, Lactobacillus casei, and Bacillus subtilis), two-dimensional angle-resolved light scattering maps are precisely measured using FTLS technique. The scattering maps are then systematically analyzed, employing statistical classification in order to extract the unique fingerprint patterns for each species, so that a new unidentified bacterium can be identified by a single light scattering measurement. The single-bacterial and label-free nature of our method suggests wide applicability for rapid point-of-care bacterial diagnosis.

  13. Sub-Nyquist sampling boosts targeted light transport through opaque scattering media

    CERN Document Server

    Shen, Yuecheng; Ma, Cheng; Wang, Lihong V


    Optical time-reversal techniques are being actively developed to focus light through or inside opaque scattering media. When applied to biological tissue, these techniques promise to revolutionize biophotonics by enabling deep-tissue non-invasive optical imaging, optogenetics, optical tweezers and photodynamic therapy. In all previous optical time-reversal experiments, the scattered light field was well-sampled during wavefront measurement and wavefront reconstruction, following the Nyquist sampling criterion. Here, we overturn this conventional practice by demonstrating that even when the scattered field is under-sampled, light can still be focused through or inside opaque media. Even more surprisingly, we show both theoretically and experimentally that the focus achieved by under-sampling is usually about one order of magnitude brighter than that achieved by conventional well-sampling conditions. Moreover, sub-Nyquist sampling improves the signal-to-noise ratio and the collection efficiency of the scattered...

  14. Stray light analysis for the Thomson scattering diagnostic of the ETE Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Berni, L. A. [Instituto Nacional de Pesquisas Espaciais (INPE), Laboratorio Associado de Sensores e Materiais (LAS), 12.227-010 Sao Jose dos Campos, SP (Brazil); Albuquerque, B. F. C. [Instituto Nacional de Pesquisas Espaciais (INPE), Engenharia e Tecnologia Espaciais, Divisao de Eletronica Aeroespacial, 12.227-010 Sao Jose dos Campos, SP (Brazil)


    Thomson scattering is a well-established diagnostic for measuring local electron temperature and density in fusion plasma, but this technique is particularly difficult to implement due to stray light that can easily mask the scattered signal from plasma. To mitigate this problem in the multipoint Thomson scattering system implemented at the ETE (Experimento Tokamak Esferico) a detailed stray light analysis was performed. The diagnostic system was simulated in ZEMAX software and scattering profiles of the mechanical parts were measured in the laboratory in order to have near realistic results. From simulation, it was possible to identify the main points that contribute to the stray signals and changes in the dump were implemented reducing the stray light signals up to 60 times.

  15. Spectral and angular distribution of light scattered from the elytra of two carabid beetle species

    Directory of Open Access Journals (Sweden)

    Raabe D.


    Full Text Available Color in living organisms is primarily generated by two mechanisms: selective absorption by pigments and structural coloration, or a combination of both. In this study, we investigated the coloration of cuticle from the wings (elytra of the two ground beetle species Carabus auronitens and Carabus auratus. The greenish iridescent color of both species is created by a multilayer structure consisting of periodically alternating layers with different thicknesses and composition which is located in the 1-2 µm thick outermost layer of the cuticle (epicuticle. Illuminated with white light, reflectance spectra in both linear polarisation show an angle-dependent characteristic peak in the blue/green region of the spectrum. Furthermore, the reflected light is polarised linearly. Scattering experiments with laser illumination at 532 nm show diffuse scattering over a larger angular range. The polarisation dependence of the scattered light is consistent with the interpretation of small inhomogeneities as scattering centres in the elytra.

  16. Monolayer spectroscopy of live standard cells: light transmission and adsorption (United States)

    Uhlemann, Juergen; Topfer, Ellen; Freyer, Richard; Vixaysakd, Darany; Entzeroth, Rudolf; Weck-Heimann, Andreas


    Photons irradiated into biological materials show interactions with cells, molecules and molecule structures, the amount of interaction being dependent on wavelength, energy density, radiation duration and properties of biological materials. Soft tissue is known to have photons strongly forward scattered, because of the inhomogeneity of its cellular and subcellular structures. The geometric dimensions of the scattering centers are in the order of wavelengths (Mie-scattering). Investigations described in this paper will show the influence of photons on single, live standard cells and how the light transmission through a monolayer cell will change within a measuring time of up to one hour and in dependence on cell intensity. Experiments were carried out in vivo with monolayers of standard bovine kidney cells by means of optical spectroscopy in a range of wavelengths from 200 nm to 1.500 nm. Cell cultures as mono cell layers in chambers of glasses were developed by a nutrient solution within 3 days. The growth of the cell layers was microscopically controlled. Details are described in the paper. Spectrophotometric measurements in visual- and near infrared range were carried out with cells on chambers of glasses (in nutrient solutions). Various effects, such as color of the nutrient solution or dying of cell regions will influence the measuring results. The measurements allow conclusions as to the determination of optimal wavelengths for an optical inspection of tissue. A photon scattering is possible preferably at the boundaries (cell faces, nuclear membrane, alteration of refractive index).

  17. Effect of scattering albedo on attenuation and polarization of light underwater. (United States)

    Cochenour, Brandon; Mullen, Linda; Muth, John


    Recent work on underwater laser communication links uses polarization discrimination to improve system performance [Appl. Opt.48, 328 (2009)] [in Proceedings of IEEE Oceans 2009 (IEEE, 2009), pp. 1-4]. In the laboratory, Maalox antacid is commonly used as a scattering agent. While its scattering function closely mimics that of natural seawaters, its scattering albedo can be much higher, as Maalox particles tend to be less absorbing. We present a series of experiments where Nigrosin dye is added to Maalox in order to more accurately recreate real-world absorption and scattering properties. We consider the effect that scattering albedo has on received power and the degree of depolarization of forward-scattered light in the context of underwater laser communication links.

  18. Light polarization oscillations induced by photon-photon scattering (United States)

    Briscese, Fabio


    We consider the Heisenberg-Euler action for an electromagnetic field in vacuum, which includes quantum corrections to the Maxwell equations induced by photon-photon scattering. We show that, in some configurations, the plane monochromatic waves become unstable, due to the appearance of secularities in the dynamical equations. These secularities can be treated using a multiscale approach, introducing a slow time variable. The amplitudes of the plane electromagnetic waves satisfy a system of ordinary differential nonlinear equations in the slow time. The analysis of this system shows that, due to the effect of photon-photon scattering, in the unstable configurations the electromagnetic waves oscillate periodically between left-hand-sided and right-hand-sided polarizations. Finally, we discuss the physical implications of this finding and the possibility of disclosing traces of this effect in optical experiments.

  19. Temporal Quantum Correlation in Inelastic Light Scattering from Water (United States)

    Saraiva, Andre; Kasperczyk, Mark; de Aguiar Junior, Filomeno; Rabelo, Cassiano; Santos, Marcelo; Novotny, Lukas; Jorio, Ado

    Water is one of the most prevalent chemicals on our planet, an integral part of both our environment and our existence as a species. Yet it is also rich in anomalous behaviors. Here we reveal that liquid water is a novel - yet ubiquitous - source for quantum correlated photon pairs. The photon pairs are produced through Raman scattering, and the correlations arise from the shared quantum of a vibrational mode between the Stokes and anti-Stokes scattering events. We confirm the nonclassical nature of the produced photon pairs by showing that the cross-correlation and autocorrelations of the signals violate a Cauchy-Schwarz inequality by over five orders of magnitude. The unprecedented degree of violating the inequality in pure water, as well as the well-defined polarization properties of the photon pairs, points to its usefulness in quantum information.

  20. Temporal Quantum Correlations in Inelastic Light Scattering from Water (United States)

    Kasperczyk, Mark; de Aguiar Júnior, Filomeno S.; Rabelo, Cassiano; Saraiva, Andre; Santos, Marcelo F.; Novotny, Lukas; Jorio, Ado


    Water is one of the most prevalent chemicals on our planet, an integral part of both our environment and our existence as a species. Yet it is also rich in anomalous behaviors. Here we reveal that water is a novel—yet ubiquitous—source for quantum correlated photon pairs at ambient conditions. The photon pairs are produced through Raman scattering, and the correlations arise from the shared quantum of a vibrational mode between the Stokes and anti-Stokes scattering events. We confirm the nonclassical nature of the produced photon pairs by showing that the cross-correlation and autocorrelations of the signals violate a Cauchy-Schwarz inequality by over 5 orders of magnitude. The unprecedented degree of violating the inequality in pure water, as well as the well-defined polarization properties of the photon pairs, points to its usefulness in quantum information.

  1. Impact of polishing on the light scattering at aerogel surface

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Danilyuk, A.F. [Novosibirsk State University, Novosibirsk (Russian Federation); Boreskov Institute of Catalysis SB RAS, Novosibirsk (Russian Federation); Katcin, A.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Kononov, S.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Kirilenko, P.S. [Novosibirsk State University, Novosibirsk (Russian Federation); Kravchenko, E.A., E-mail: [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Kuyanov, I.A. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Onuchin, A.P.; Ovtin, I.V. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Novosibirsk State Technical University, Novosibirsk (Russian Federation); Predein, A.Yu.; Protsenko, R.S. [Boreskov Institute of Catalysis SB RAS, Novosibirsk (Russian Federation)


    Particle identification power of modern aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing cannot be described by the standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for the Focusing Aerogel RICH detectors.

  2. Resonant chirality in light scattered from magnetodielectric particles

    CERN Document Server

    Nieto-Vesperinas, Manuel


    We show that the total heliciity of the field scattered by a magnetodielectric particle, bi-isotropic or not, is enhanced not only because of the resonant polarizabilities, but also due to the interference between the left and right circularly polarized components of the incident wave, which in absence of incident helicity does not necessarily require the particle to be chiral. This latter effect goes beyond standard dichroism and may be considered a generalization of this phenomenon.

  3. Alpha Inelastic Scattering and Cluster Structures in Light Nuclei

    CERN Document Server

    Kawabata, T


    The cluster structures of the excited states in 11B and 13C were discussed by measuring the isoscalar monopole strengths in the inelastic scattering at E = 388 MeV. It was found that the 1/2− 2 , 1/2− 3 , and 1/2− 4 states in 13C are candidates for the cluster states with a 3 + n molecular configuration.

  4. Light scattering by coated sphere immersed in absorbing medium: a comparison between the FDTD and analytic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sun Wenbo E-mail:; Loeb, Norman G.; Fu Qiang


    A recently developed finite-difference time domain scheme is examined using the exact analytic solutions for light scattering by a coated sphere immersed in an absorbing medium. The relative differences are less than 1% in the extinction, scattering, and absorption efficiencies and less than 5% in the scattering phase functions. The definition of apparent single-scattering properties is also discussed.

  5. Phase measurement of light absorption and scatter in human tissue (United States)

    Chance, B.; Cope, M.; Gratton, E.; Ramanujam, N.; Tromberg, B.


    Analog and digital technologies are presented for precise measurement of propagation delay of photons from source and detector placed on portions of the human body. The goal of the apparatus design is to quantify absorption (μa) and scattering (μs') induced by biological pigments and biological structures, respectively. Body tissues are highly scattering with a mean distance between scatterers of less than a mm (at 700-850 nm). Significant absorption is mainly due to 5%-10% of the tissue volume occupied by blood. Measurement of μa and μs' is done by both time and frequency domain equipment. This article focuses upon frequency domain equipment because of its simplicity, reduced noise bandwidth, versatility, and the strong analogy to very high frequency/ultrahigh frequency communication devices, particularly those using phase modulation. Comparisons are made of homodyne and heterodyne systems together with evaluation of single and multiple side band systems, with particular emphasis on methods for multiplexed optical and radio frequencies by frequency encoding or time-sharing technologies. The applications of these phase modulation systems to quantitative brain and muscle blood oximetry, functional activity of the forebrain, and other important problems of medical science, are presented.

  6. Polarized scattered light from self-luminous exoplanets : Three-dimensional scattering radiative transfer with ARTES

    NARCIS (Netherlands)

    Stolker, T.; Min, M.; Stam, D.M.; Mollière, P.; Dominik, C.; Waters, L. B.F.M.


    Context. Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a horizontally-inhomogeneous atmosphere causes the disk-integrated polarization of the thermal radiation to be linearly polarized, possibly detectable with the newest

  7. Dispersion relation for hadronic light-by-light scattering: two-pion contributions (United States)

    Colangelo, Gilberto; Hoferichter, Martin; Procura, Massimiliano; Stoffer, Peter


    In this third paper of a series dedicated to a dispersive treatment of the hadronic light-by-light (HLbL) tensor, we derive a partial-wave formulation for two-pion intermediate states in the HLbL contribution to the anomalous magnetic moment of the muon ( g - 2) μ , including a detailed discussion of the unitarity relation for arbitrary partial waves. We show that obtaining a final expression free from unphysical helicity partial waves is a subtle issue, which we thoroughly clarify. As a by-product, we obtain a set of sum rules that could be used to constrain future calculations of γ ∗ γ ∗ → ππ. We validate the formalism extensively using the pion-box contribution, defined by two-pion intermediate states with a pion-pole left-hand cut, and demonstrate how the full known result is reproduced when resumming the partial waves. Using dispersive fits to high-statistics data for the pion vector form factor, we provide an evaluation of the full pion box, a μ π - box = - 15.9(2) × 10- 11. As an application of the partial-wave formalism, we present a first calculation of ππ-rescattering effects in HLbL scattering, with γ ∗ γ ∗ → ππ helicity partial waves constructed dispersively using ππ phase shifts derived from the inverse-amplitude method. In this way, the isospin-0 part of our calculation can be interpreted as the contribution of the f 0(500) to HLbL scattering in ( g - 2) μ . We argue that the contribution due to charged-pion rescattering implements corrections related to the corresponding pion polarizability and show that these are moderate. Our final result for the sum of pion-box contribution and its S-wave rescattering corrections reads a μ π - box + a μ, J = 0 ππ, π - pole LHC = - 24(1) × 10- 11.

  8. Small-angle neutron and dynamic light scattering study of gelatin ...

    Indian Academy of Sciences (India)

    The state of intermolecular aggregates and that of folded gelatin molecules could be characterized by dynamic laser light and small-angle neutron scattering experiments, which implied spontaneous segregation of particle sizes preceding coacervation, which is a liquid-liquid phase transition phenomenon. Dynamic light ...

  9. Maximizing the information transfer in a quantum-limited light-scattering system

    DEFF Research Database (Denmark)

    Lading, Lars; Jørgensen, Thomas Martini


    A quantum-limited light-scattering system is considered. The spatial configuration that maximizes a given figure of merit is investigated, assuming that the emitted light has Poisson photon statistics. A specific system for measuring the velocity of a small particle is considered as an example. A...

  10. Mid-infrared (λ = 8.4-9.9 μm) light scattering from porcine tissue (United States)

    Liakat, Sabbir; Michel, Anna P. M.; Bors, Kevin A.; Gmachl, Claire F.


    Back-scattering of mid-infrared light from porcine skin is studied versus wavelength and angle for a Quantum Cascade laser and a broadband infrared light source. Scattering is detected over 30° away from the specular angle for both sources, and modulation patterns with angle are seen when using the laser. A nonlinear increase in scattered light intensity versus input power indicates that directional scattering from within the skin is dominant. Collagen fibers in the dermis layer, over 200 μm deep into the skin, are conducive to such scattering. We conclude that mid-infrared light penetrates deep enough for potential glucose detection in dermal interstitial fluid.

  11. Morphology effect on the light scattering and dynamic response of polymer network liquid crystal phase modulator. (United States)

    Xiangjie, Zhao; Cangli, Liu; Jiazhu, Duan; Jiancheng, Zeng; Dayong, Zhang; Yongquan, Luo


    Polymer network liquid crystal (PNLC) was one of the most potential liquid crystal for submillisecond response phase modulation, which was possible to be applied in submillisecond response phase only spatial light modulator. But until now the light scattering when liquid crystal director was reoriented by external electric field limited its phase modulation application. Dynamic response of phase change when high voltage was applied was also not elucidated. The mechanism that determines the light scattering was studied by analyzing the polymer network morphology by SEM method. Samples were prepared by varying the polymerization temperature, UV curing intensity and polymerization time. The morphology effect on the dynamic response of phase change was studied, in which high voltage was usually applied and electro-striction effect was often induced. The experimental results indicate that the polymer network morphology was mainly characterized by cross linked single fibrils, cross linked fibril bundles or even both. Although the formation of fibril bundle usually induced large light scattering, such a polymer network could endure higher voltage. In contrast, although the formation of cross linked single fibrils induced small light scattering, such a polymer network cannot endure higher voltage. There is a tradeoff between the light scattering and high voltage endurance. The electro-optical properties such as threshold voltage and response time were taken to verify our conclusion. For future application, the monomer molecular structure, the liquid crystal solvent and the polymerization conditions should be optimized to generate optimal polymer network morphology.

  12. Experimental light scattering by ultrasonically controlled small particles - Implications for Planetary Science (United States)

    Gritsevich, M.; Penttilä, A.; Maconi, G.; Kassamakov, I.; Markkanen, J.; Martikainen, J.; Väisänen, T.; Helander, P.; Puranen, T.; Salmi, A.; Hæggström, E.; Muinonen, K.


    We present the results obtained with our newly developed 3D scatterometer - a setup for precise multi-angular measurements of light scattered by mm- to µm-sized samples held in place by sound. These measurements are cross-validated against the modeled light-scattering characteristics of the sample, i.e., the intensity and the degree of linear polarization of the reflected light, calculated with state-of-the-art electromagnetic techniques. We demonstrate a unique non-destructive approach to derive the optical properties of small grain samples which facilitates research on highly valuable planetary materials, such as samples returned from space missions or rare meteorites.

  13. A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner, E-mail: [Institut für Biophysik, Goethe-Universität Frankfurt am Main, Max-von Laue-Straße 1, D-60438 Frankfurt am Main (Germany)


    A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

  14. A setup for simultaneous measurement of infrared spectra and light scattering signals: Watching amyloid fibrils grow from intact proteins (United States)

    Li, Yang; Maurer, Jürgen; Roth, Andreas; Vogel, Vitali; Winter, Ernst; Mäntele, Werner


    A setup for the simultaneous measurement of mid-infrared spectra and static light scattering is described that can be used for the analysis of the formation of nanoscale and microscopic aggregates from smaller molecules to biopolymers. It can be easily integrated into sample chambers of infrared spectrometers or combined with laser beams from tunable infrared lasers. Here, its use for the analysis of the formation of amyloid fibrils from intact proteins is demonstrated. The formation of amyloid fibrils or plaques from proteins is a widespread and pathogenetic relevant process, and a number of diseases are caused and correlated with the deposition of amyloid fibrils in cells and tissues. The molecular mechanisms of these transformations, however, are still unclear. We report here the simultaneous measurement of infrared spectra and static light scattering for the analysis of fibril formation from egg-white lysozyme. The transformation of the native form into non-native forms rich in β-sheet structure is measured by analysis of the amide I spectral region in the infrared spectra, which is sensitive for local structures. At the same time, light scattering signals at forward direction as well as the forward/backward ratio, which are sensitive for the number of scattering centers and their approximate sizes, respectively, are collected for the analysis of fibril growth. Thermodynamic and kinetic parameters as well as mechanistic information are deduced from the combination of the two complementary techniques.

  15. Theoretical analysis and experiment performance of slow-light based on stimulated Brillouin scattering (SBS) (United States)

    Zhou, Hongyan; Zhong, Kun; Zhang, Ru; Lang, Peilin


    Slow light technology will play a key role in future all-optical communication. The slow-light technology based on stimulated Brillouin scattering has become a research highlight because of its additional advantages, such as compatibility of the devices with existing telecommunication systems, room-temperature operation, and tunable at arbitrary wavelengths. According to the propagation of a cw pulse through a Brillouin fiber amplifier, whose frequency is near the Stokes resonance, via three-wave coupling equations, both pump depletion and fiber losses taken into consideration, the principle of how slow-light effect based on stimulated Brillouin scattering produced and the mathematical expression of time delay are strictly deduced. A delay of 8 ns is obtained when the input Stokes pulse is 200ns and the SBS (stimulated Brillouin scattering) gain G is ~18 in our designed experiment of SBS slow-light system. Then the extent of transformation from pump waves to Stokes waves is measured using MATLAB numerical simulation according to the experiment dates, based on the relation between output pump light power and input pump light power and also the relation between output Stokes light power and input pump light power. And the relation between the input light power and propagation distance is discussed as well. Finally the relation between slow light pulse delay and SBS gain is also obtained.

  16. Sub-Nyquist sampling boosts targeted light transport through opaque scattering media. (United States)

    Shen, Yuecheng; Liu, Yan; Ma, Cheng; Wang, Lihong V


    Optical time-reversal techniques are being actively developed to focus light through or inside opaque scattering media. When applied to biological tissue, these techniques promise to revolutionize biophotonics by enabling deep-tissue non-invasive optical imaging, optogenetics, optical tweezing, and phototherapy. In all previous optical time-reversal experiments, the scattered light field was well-sampled during wavefront measurement and wavefront reconstruction, following the Nyquist sampling criterion. Here, we overturn this conventional practice by demonstrating that even when the scattered field is under-sampled, light can still be focused through or inside scattering media. Even more surprisingly, we show both theoretically and experimentally that the focus achieved by under-sampling can be one order of magnitude brighter than that achieved under the well-sampling conditions used in previous works, where 3×3 to 5×5 pixels were used to sample one speckle grain on average. Moreover, sub-Nyquist sampling improves the signal-to-noise ratio and the collection efficiency of the scattered light. We anticipate that this newly explored under-sampling scheme will transform the understanding of optical time reversal and boost the performance of optical imaging, manipulation, and communication through opaque scattering media.

  17. Differential spectral imaging with gold nanorod light scattering labels (United States)

    Qiu, Le; Vitkin, Edward; Guo, Lianyu; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.


    Gold nanorods have the potential to be employed as extremely bright molecular marker labels. However, samples containing a large number of gold nanorods usually exhibit relatively wide spectral lines. This linewidth limits the use of the nanorods since it would be rather difficult to image several types of nanorod markers simultaneously. We measured native scattering spectra of single gold nanorods with the CLASS microscope and found that single gold nanorods have a narrow spectrum as predicted by the theory. That suggests that nanorod-based molecular markers with controlled narrow aspect ratios should provide spectral lines sufficiently narrow for effective biomedical imaging.

  18. Skeletal light-scattering accelerates bleaching response in reef-building corals. (United States)

    Swain, Timothy D; DuBois, Emily; Gomes, Andrew; Stoyneva, Valentina P; Radosevich, Andrew J; Henss, Jillian; Wagner, Michelle E; Derbas, Justin; Grooms, Hannah W; Velazquez, Elizabeth M; Traub, Joshua; Kennedy, Brian J; Grigorescu, Arabela A; Westneat, Mark W; Sanborn, Kevin; Levine, Shoshana; Schick, Mark; Parsons, George; Biggs, Brendan C; Rogers, Jeremy D; Backman, Vadim; Marcelino, Luisa A


    At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as 'microscopic' reduced-scattering coefficient, μ'(S,m)), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-μ'(S,m) corals bleach at higher rate and severity than high-μ'(S,m) corals and the Symbiodinium associated with low-μ'(S,m) corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-μ'(S,m) corals. While symbionts associated with low-[Formula: see text] corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor

  19. Asymmetric Flow-Field Flow Fractionation (AF4) of Aqueous C60 Aggregates with Dynamic Light Scattering Size and LC-MS (United States)

    Current methods for the size determination of nanomaterials in aqueous suspension include dynamic or static light scattering and electron or atomic force microscopy techniques. Light scattering techniques are limited by poor resolution and the scattering intensity dependence on p...

  20. Light scattering by a nematic liquid crystal droplet: Wentzel–Kramers–Brillouin approximation

    Energy Technology Data Exchange (ETDEWEB)

    Loiko, V. A., E-mail:; Konkolovich, A. V.; Miskevich, A. A. [National Academy of Science of Belarus, Stepanov Institute of Physics (Belarus)


    Light scattering by an optically anisotropic liquid crystal (LC) droplet of a nematic in an isotropic polymer matrix is considered in the Wentzel–Kramers–Brillouin (WKB) approximation. General relations are obtained for elements of the amplitude matrix of light scattering by a droplet of arbitrary shape and for the structure of the director field. Analytic expressions for the amplitude matrices are derived for spherical LC droplets with a uniformly oriented structure of local optical axes for strictly forward and strictly backward scattering. The efficiency factors of extinction and backward scattering for a spherical nonabsorbing LC droplet depending on the LC optical anisotropy, refractive index of the polymer, illumination conditions, and orientation of the optical axis of the droplet are analyzed. Verification of the obtained solutions has been performed.

  1. A simple student laboratory practice for the study of light scattering by cylindrical bodies (United States)

    Mabiala Masiala, Toto; Phuku Phuati, Edmond; Kazadi Mukenga, B. Albert


    The study of light scattering by cylindrical bodies is of great importance in many aspects, but most of the time; it is studied in a very theoretical manner. In that work, we present a simple manner to study scattering of light by cylindrical bodies. The method combines the use of a simple experimental set-up using a He-Ne laser as a source, a circular paper screen, and the use of a simple code for simulation using the Lorentz-Mie formalism. In that way, the student can compare the experimental results with the simulation. They can qualitatively notice the difference of the behavior of scattering by a low-loss dielectric cylinder, a metallic cylinder, and an absorbing cylinder. Simulation can help students to follow the evolution of the scattering regime when the relative diameter of the cylinder, with respect to the incident wavelength, changes. A focus is stressed especially when the radius becomes far below the wavelength.

  2. Measuring spatially- and directionally-varying light scattering from biological material. (United States)

    Harvey, Todd Alan; Bostwick, Kimberly S; Marschner, Steve


    Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Milli-scale and macro-scale effects determine where on the organism's body, and from what viewpoints and under what illumination, the iridescent colors are seen. Thus, the highly directional flash of brilliant color from the iridescent throat of a hummingbird is inadequately explained by its nano-scale structure alone and questions remain. From a given observation point, which milli-scale elements of the feather are oriented to reflect strongly? Do some species produce broader "windows" for observation of iridescence than others? These and similar questions may be asked about any organisms that have evolved a particular surface appearance for signaling, camouflage, or other reasons. In order to study the directional patterns of light scattering from feathers, and their relationship to the bird's milli-scale morphology, we developed a protocol for measuring light scattered from biological materials using many high-resolution photographs taken with varying illumination and viewing directions. Since we measure scattered light as a function of direction, we can observe the characteristic features in the directional distribution of light scattered from that particular feather, and because barbs and barbules are resolved in our images, we can clearly attribute the directional features to these different milli-scale structures. Keeping the specimen intact preserves the gross-scale scattering behavior seen in nature. The method described here presents a generalized protocol for analyzing spatially- and directionally-varying light scattering from complex biological materials at multiple

  3. Characterization of the angular memory effect of scattered light in biological tissues. (United States)

    Schott, Sam; Bertolotti, Jacopo; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain


    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues and therefore grants access to superficial brain layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations ('angular memory effect') are of a very short range and should theoretically be only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range and thus the possible field-of-view by more than an order of magnitude compared to isotropic scattering for ∼1 mm thick tissue layers.

  4. In vivo transcranial measurement of light scattering in rat brains during hypoxia (United States)

    Kawauchi, Satoko; Sato, Shunichi; Uozumi, Yoichi; Nawashiro, Hiroshi; Ishihara, Miya; Kikuchi, Makoto


    Measurement of intrinsic optical signals (IOSs) is attractive for noninvasive, real-time monitoring of tissue viability in brains. We previously performed measurement of IOSs for a rat global ischemic brain model that was made by rapidly removing blood by saline infusion, and observed that after an induction of ischemia, a unique triphasic change in light scattering occurred. This scattering change preceded the reduction of CuA in cytochrome c oxidase which has been shown to correlate with cerebral ATP decrease. In the present study, we examined whether such triphasic scattering change can be observed in the presence of blood in vivo. Transcranial measurement of diffuse reflectance was performed using a broadband tungsten lamp for a rat brain during hypoxia that was induced by N2 inhalation. The reflectance spectral changes in the visible (500-600 nm) and near-infrared (NIR) (650-850 nm) regions were analyzed to monitor changes in hemodynamics and light scattering, respectively. After starting N2 inhalation, reflectance signals in the visible region showed an increase in deoxy-hemoglobin concentration, and about 80 s after full deoxygenation of hemoglobins, reflectance signals in the NIR region showed a similar triphasic change, which was attributable to change in light scattering. Simultaneous measurement of cerebral EEG showed that neuronal activity ceased about 50 s before this triphasic scattering change. These results show that light scattering will become an important indicator of loss of tissue viability in brain; brain tissue can probably be saved if reoxygenation is achieved before starting this scattering change.

  5. Autocorrelation of scattered laser light for ultrasound-modulated optical tomography in dense turbid media. (United States)

    Li, Hui; Wang, Lihong V


    Based on measurement of the intensity autocorrelation function, a new method to determine the modulation depth of scattered laser light modulated by an ultrasonic wave in turbid media was applied to ultrasound-modulated optical tomography. Good signal-to-noise ratios and high sensitivities were demonstrated. Images of double optically absorbing objects buried in a highly optically scattering gel sample were obtained. The contrast was more than 10%, and the spatial resolution was approximately 2 mm.

  6. Autocorrelation of scattered laser light for ultrasound-modulated optical tomography in dense turbid media


    Li, Hui; Wang, Lihong V.


    Based on measurement of the intensity autocorrelation function, a new method to determine the modulation depth of scattered laser light modulated by an ultrasonic wave in turbid media was applied to ultrasound-modulated optical tomography. Good signal-to-noise ratios and high sensitivities were demonstrated. Images of double optically absorbing objects buried in a highly optically scattering gel sample were obtained. The contrast was more than 10%, and the spatial resolution was approximately...

  7. Light Scatter in Optical Materials: Advanced Haze Modeling (United States)


    glare. Haze can be inherent in the material, a result of the molding process, or a result of surface texture. Haze can also be a result of...detector (10 mm diameter silicon photodiode) located 1000 mm from the sample. A partially-collimated probe beam of 532 nm laser light was used to

  8. Optical fibre probes in the measurement of scattered light ...

    Indian Academy of Sciences (India)


    Jan 8, 2014 ... Optical fibre probes or optrodes often form the heart of multimode fibre-based measurements and sensors. An optrode usually comprises a bundle of multimode fibres, out of which one or more fibres are used for irradiating the sample, and the remaining fibres are used to collect the light ...

  9. Noise from scattered light in Virgo's second science run data

    NARCIS (Netherlands)

    Accadia, T.; Bulten, H.J.; Rabeling, D.S.; van den Brand, J.F.J.


    Virgo is one of the large, ground-based interferometers aimed at detecting gravitational waves. One of the technical problems limiting its sensitivity is caused by light in the output beams which is backscattered by seismically excited surfaces and couples back into the main beam of the

  10. Determining the Liquid Light Scattering Cross Section and Depolarization Spectra Using Polarized Resonance Synchronous Spectroscopy. (United States)

    Athukorale, Sumudu A; Zhou, Yadong; Zou, Shengli; Zhang, Dongmao


    Rayleigh scattering is a universal material property because all materials have nonzero polarizability. Reliable quantification of the material light scattering cross section in the liquid phase and its depolarization spectra is, however, challenging due to a host of sample and instrument issues. Using the recently developed polarized resonance synchronous spectroscopic method, we reported the light scattering cross section and depolarization spectra measured for a total of 29 liquids including water, methanol, ethanol, 1-propanol, 1-butanol, dimethylformamide, carbon disulfide, dimethyl sulfoxide, hexane and two hexane isomers (3-methylpentane and 2,3-dimethylbutane), tetrahydrofuran, cyclohexane, acetonitrile, pyridine, chloromethanes including di-, tri, tetrachloromethane, acetone, benzene and eight benzene derivatives (toluene, fluorobenzene, 1,2-, 1,3-, and 1,4-difluorobenzene, chlorobenzene, 1,2- and 1,3-dichlorobenzene, and nitrobenzene). The solvent light scattering depolarization is wavelength-independent for the model solvents, and it varies from 0.023 ± 0.011 for CCl4 to 0.619 ± 0.022 for nitrobenzene. The light scattering cross-section spectra can be approximated with the function of σ(λ) = αλ(-4) with the α value varying from 7.2 ± 0.2 × 10(-45) cm(6) for water to a maximum of 8.5 ± 0.6 × 10(-43) cm(6) for nitrobenzene. Structural isomerization has no significant effect on either the depolarization or the scattering cross sections for both hexanes and difluorobenzene isomers. This work represents the most comprehensive experimental study on liquid light scattering features. The insight from this work should be important for understanding the correlation between the material structure and optical properties. The described method can be readily implemented by researchers with access to conventional spectrofluorometers equipped with excitation and detection polarizers.

  11. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation. (United States)

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Shi, Junhui; Wang, Lihong V


    Wavefront shaping based on digital optical phase conjugation (DOPC) focuses light through or inside scattering media, but the low speed of DOPC prevents it from being applied to thick, living biological tissue. Although a fast DOPC approach was recently developed, the reported single-shot wavefront measurement method does not work when the goal is to focus light inside, instead of through, highly scattering media. Here, using a ferroelectric liquid crystal based spatial light modulator, we develop a simpler but faster DOPC system that focuses light not only through, but also inside scattering media. By controlling 2.6 × 105 optical degrees of freedom, our system focused light through 3 mm thick moving chicken tissue, with a system latency of 3.0 ms. Using ultrasound-guided DOPC, along with a binary wavefront measurement method, our system focused light inside a scattering medium comprising moving tissue with a latency of 6.0 ms, which is one to two orders of magnitude shorter than those of previous digital wavefront shaping systems. Since the demonstrated speed approaches tissue decorrelation rates, this work is an important step toward in vivo deep-tissue non-invasive optical imaging, manipulation, and therapy.

  12. Light focusing through a multiple scattering medium: ab initio computer simulation (United States)

    Danko, Oleksandr; Danko, Volodymyr; Kovalenko, Andrey


    The present study considers ab initio computer simulation of the light focusing through a complex scattering medium. The focusing is performed by shaping the incident light beam in order to obtain a small focused spot on the opposite side of the scattering layer. MSTM software (Auburn University) is used to simulate the propagation of an arbitrary monochromatic Gaussian beam and obtain 2D distribution of the optical field in the selected plane of the investigated volume. Based on the set of incident and scattered fields, the pair of right and left eigen bases and corresponding singular values were calculated. The pair of right and left eigen modes together with the corresponding singular value constitute the transmittance eigen channel of the disordered media. Thus, the scattering process is described in three steps: 1) initial field decomposition in the right eigen basis; 2) scaling of decomposition coefficients for the corresponding singular values; 3) assembling of the scattered field as the composition of the weighted left eigen modes. Basis fields are represented as a linear combination of the original Gaussian beams and scattered fields. It was demonstrated that 60 independent control channels provide focusing the light into a spot with the minimal radius of approximately 0.4 μm at half maximum. The intensity enhancement in the focal plane was equal to 68 that coincided with theoretical prediction.

  13. The impacts of light scattering by clouds on longwave radiative transfer (United States)

    Kuo, C. P.; Yang, P.; Huang, X.; Feldman, D.; Flanner, M.


    In the longwave spectrum, clouds modulate energy budgets in the climate system through scattering, absorbing and emitting radiation. On the average, ice clouds tend to warm the climate, while liquid water clouds cool the climate, due to the distinct physical and optical properties of ice and liquid water clouds. General circulation models (GCMs) are the most popular tool to investigate the influences of clouds on climate. However, most GCMs, due to computational complexity, neglect multiple scattering effects in longwave radiative transfer calculations. To evaluate the potential impacts of neglecting longwave multiple scattering, we conduct sensitivity studies, utilizing the ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis atmospheric profiles, a modified RRTMG_LW (Longwave Rapid Radiative Transfer Model for GCM applications) and the MODIS (Moderate Resolution Imaging Spectroradiometer) collection 6 level 3 cloud retrieval products. The modified RRTMG_LW uses the 16-stream DISORT (Discrete Ordinates Radiative Transfer Program for a Multi-Layered Plane-Parallel Medium) as a robust radiative solver to calculate longwave fluxes. In the study, the bias in longwave flux (simulated without, minus simulated with, light scattering by ice and liquid water clouds) represents the influence of neglecting light scattering. Biases of upward flux at the top of the atmosphere, downward flux at the surface, and net flux into the atmosphere are presented. The preliminary results show that the absence of longwave light scattering could lead to considerable biases in global and regional flux simulations.

  14. Effect of corneal light scatter on vision: a review of the literature

    Directory of Open Access Journals (Sweden)

    Leopoldo Spadea


    Full Text Available The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it.

  15. Coherent light scattering of heterogeneous randomly rough films and effective medium in the theory of electromagnetic wave multiple scattering

    Energy Technology Data Exchange (ETDEWEB)

    Berginc, G [THALES, 2 avenue Gay-Lussac 78995 ELANCOURT (France)


    We have developed a general formalism based on Green's functions to calculate the coherent electromagnetic field scattered by a random medium with rough boundaries. The approximate expression derived makes it possible to determine the effective permittivity, which is generalised for a layer of an inhomogeneous random medium with different types of particles and bounded with randomly rough interfaces. This effective permittivity describes the coherent propagation of an electromagnetic wave in a random medium with randomly rough boundaries. We have obtained an expression, which contains the Maxwell – Garnett formula at the low-frequency limit, and the Keller formula; the latter has been proved to be in good agreement with experiments for particles whose dimensions are larger than a wavelength. (coherent light scattering)

  16. Importance of light scattering properties of cloud particles on calculating the earth energy cycle (United States)

    Letu, H.; Nakajima, T. Y.; Nagao, T. M.; Ishimoto, H.


    The Earth is an open system, and the energy cycle of the Earth is not always a certain amount. In other words, the energy cycle in the nature is imbalance. A better understanding of the earth energy cycle is very important to study global climate change. the IPCC-AR4 reported that the cloud in the atmosphere are still characterized by large uncertainties in the estimation of their effects on energy sysle of the Earth's atmosphere. There are two types of cloud in the atmosphere, which are Cirrus and warm water cloud. In order to strongly reflect visible wavelength from sun light, thick water cloud has the effect of cooling the earth surface. When Cirrus is compared to water cloud, temperature is almost lower. Thus, there is a feature that Cirrus is easy to absorb long-wave radiation than warm water cloud. However, in order to quantitatively evaluate the reflection and absorption characteristics of cloud on remote senssing application and energy cycle of the imbalance of nature, it is necessary to obtain the scattering properties of cloud particles. Since the shapes of the water cloud particle are close to spherical, scattering properties of the particles can be calculated accurately by the Mie theory. However, Cirrus particles have a complex shape, including hexagonal, plate, and other non- spherical shapes. Different from warm water cloud partical, it is required to use several different light scattering methods when calculating the light scattering properties of the non-spherical Cirrus cloud particals. Ishimoto et al. [2010, 2012] and Masuda et al. [2012] developed the Finite-Difference Time Domain method (FDTD) and Improved Geometrical-Optics Method (IGOM) for the solution of light scattering by non-spherical particles. Nakajima et al [1997,2009] developed the LIght Scattering solver for Arbitral Shape particle (Lisas)-Geometrical-Optics Method (GOM) and Surface Integral Equations Method of Müller-type (SIEMM) to calculate the light scattering properties for

  17. Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, A E; Potapov, V T [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino Branch, Fryazino, Moscow region (Russian Federation); Gorshkov, B G [OOO ' Petrofaiber' , Russia, Tula region, Novomoskovsk (Russian Federation)


    Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer to external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)

  18. Continuous-wave spatial quantum correlations of light induced by multiple scattering

    DEFF Research Database (Denmark)

    Smolka, Stephan; Ott, Johan Raunkjær; Huck, Alexander


    We present theoretical and experimental results on spatial quantum correlations induced by multiple scattering of nonclassical light. A continuous-mode quantum theory is derived that enables determining the spatial quantum correlation function from the fluctuations of the total transmittance and ...... theory and form a basis for future research on, e. g., quantum interference of multiple quantum states in a multiple scattering medium.......We present theoretical and experimental results on spatial quantum correlations induced by multiple scattering of nonclassical light. A continuous-mode quantum theory is derived that enables determining the spatial quantum correlation function from the fluctuations of the total transmittance...... and reflectance. Utilizing frequency-resolved quantum noise measurements, we observe that the strength of the spatial quantum correlation function can be controlled by changing the quantum state of an incident bright squeezed-light source. Our results are found to be in excellent agreement with the developed...

  19. Numerical simulations of scattering of light from two-dimensional surfaces using the Reduced Rayleigh Equation

    CERN Document Server

    Nordam, Tor; Simonsen, Ingve


    A formalism is introduced for the nonperturbative purely numerical solution of the reduced Rayleigh equation for the scattering of light from two-dimensional penetrable rough surfaces. As an example, we in this way study the scattering of p- or s-polarized light from two-dimensional dielectric or metallic randomly rough surfaces by calculating the full angular distribution of the co- and cross-polarized intensity of the scattered light. In particular, we present calculations of the mean differential reflection coefficient for glass and silver surfaces characterized by Gaussian and cylindrical power spectra. We find our results to be in agreement with previous work. The proposed method is found, within the validity of the Rayleigh hypothesis, to give reliable results. In particular, for a non-absorbing metal the conservation of energy is explicitly checked, and found to be satisfied to within 0.03% or better for the simulation results presented.

  20. Determination of liquid-liquid critical point composition using 90∘ laser light scattering (United States)

    Williamson, J. Charles; Brown, Allison M.; Helvie, Elise N.; Dean, Kevin M.


    Despite over a century of characterization efforts, liquid-liquid critical point compositions are difficult to identify with good accuracy. Reported values vary up to 10% for even well-studied systems. Here, a technique is presented for high-precision determination of the critical composition of a partially miscible binary liquid system. Ninety-degree laser light-scattering intensities from single-phase samples are analyzed using an equation derived from nonclassical power laws and the pseudospinodal approximation. Results are reported for four liquid-liquid systems (aniline + hexane, isobutyric acid + water, methanol + cyclohexane, and methanol + carbon disulfide). Compared to other methods, the 90∘ light-scattering approach has a strong dependence on composition near the critical point, is less affected by temperature fluctuations, and is insensitive to the presence of trace impurities in the samples. Critical compositions found with 90∘ light scattering are precise to the parts-per-thousand level and show long-term reproducibility.

  1. Overcoming Angular Dependency When Teaching Light Scattering Using a Spectrofluorometer: The Molecular Weight of Latex Beads (United States)

    Santos, Nuno C.; Fernandes, Miguel X. J. J.; Castanho, Miguel A. R. B.


    When using a spectrofluorometer in light-scattering experiments, it is impossible to perform angle-dependent studies. At first glance, this restriction seems to students to be an insurmountable obstacle. However, a spectrofluorometer offers some potentialities not available with classical laser light scattering spectroscopy, namely, the availability of broader wavelength ranges. Changing the wavelength changes the magnitude of the scattering vector. This has the same effect as a change in the measurement angle. Thus, it is possible to overcome angle dependency by accounting for wavelength dependency. This "shift" in dependencies is easily accessed by students because it results directly from the usual formalisms used in light scattering. Moreover, the students are encouraged, in practice, to elaborate innovative solutions, even from classical formalisms. This methodology is applied to the calculation of a series of molecular weights of polystyrene latex spheres. This system has several advantages: (i) water miscibility, (ii) definite shape, (iii) monodispersity (both size and shape), (iv) low cost, and (v) availability of latex spheres in a wide variety of sizes and composition. Although very well characterized with respect to size and shape (mainly by dynamic light scattering and electronic microscopy), latex spheres have been poorly studied in terms of molecular weight. Consequently, working in an innovative area of research proves stimulating for the students.

  2. Light scattering by lungs correlates with stereological measurements. (United States)

    Suzuki, S; Butler, J P; Oldmixon, E H; Hoppin, F G


    The pattern of light backscattered by lung tissue should depend strongly on the size of air spaces and equivalently on the internal surface area of the lung. To verify and apply this, we shone a laser beam into excised lungs through the pleural surface and measured the backscattered light surrounding the beam with a focused photodetector. The intensity, I, fell off as a function of distance, r, from the point of entry of light. The configurations of I(r) curves corresponded closely to theory over a 3-decade range of I. I(r) changed systematically with lung volume. The optical mean free path, lambda, was calculated from I(r) curves in a series of canine lobes fixed immediately after optical scanning and was compared with stereological measurement of mean linear intercept, Lm, an index of alveolar size. At high lung volumes the relation of lambda to Lm was consistent with reflection by alveolar septa. At lower lung volumes there appeared to be, additionally, a substantial refractive component. This technique is independent of current stereological methods and has the advantages of being noninvasive, continuous, and potentially applicable to dynamic events in unfixed lungs.

  3. Application of dynamic light scattering for studying the evolution of micro- and nano-droplets (United States)

    Derkachov, G.; Jakubczyk, D.; Kolwas, K.; Shopa, Y.; Woźniak, M.; Wojciechowski, T.


    The dynamic light scattering (DLS) technique was used for studying the processes of aggregation of spherical SiO2 particles in various diethylene glycol (DEG) suspensions. The suspensions were studied in a cuvette, in a millimeter-sized droplet and in a micrometer-sized droplet. For the first time DLS signals for droplets of picolitre volume, levitated in an electrodynamic quadrupole trap, were obtained. It is shown that the correlation analysis of light scattered from a micro-droplet allows monitoring the changes of its internal structure, as well as its motions: trap-constricted Brownian motions and random rotations.

  4. Studying aerosol light scattering based on aspect ratio distribution observed by fluorescence microscope. (United States)

    Li, Li; Zheng, Xu; Li, Zhengqiang; Li, Zhanhua; Dubovik, Oleg; Chen, Xingfeng; Wendisch, Manfred


    Particle shape is crucial to the properties of light scattered by atmospheric aerosol particles. A method of fluorescence microscopy direct observation was introduced to determine the aspect ratio distribution of aerosol particles. The result is comparable with that of the electron microscopic analysis. The measured aspect ratio distribution has been successfully applied in modeling light scattering and further in simulation of polarization measurements of the sun/sky radiometer. These efforts are expected to improve shape retrieval from skylight polarization by using directly measured aspect ratio distribution.

  5. Light scattering from aqueous solutions of colloid metal nanoparticles stabilized by natural polysaccharide arabinogalactan. (United States)

    Gasilova, Ekaterina R; Toropova, Anna A; Bushin, Stanislav V; Khripunov, Albert K; Grischenko, Ludmila A; Aleksandrova, Galina P


    Colloids of metal nanoparticles (NPs) of Au, Ag, Pd, and Pt protected by natural polymer arabinogalactan (ARB) extracted from Larix sibirica were studied. The nanocomposites were prepared by reduction of metal salts in the water solutions of ARB. We carried out dynamic (DLS) and static light scattering resonantly enhanced by the NP plasmons. The translational diffusion was examined via DLS and a polarized interferometer. The virgin ARB was shown to form aggregates in dilute aqueous solutions. The introduction of NPs reduced the size of the virgin ARB aggregates. The aggregate forms as viewed by the scanning electron microscopy support the light scattering results.

  6. Electron scattering disintegration processes on light nuclei in covariant approach

    Directory of Open Access Journals (Sweden)

    Kuznietsov P.E.


    Full Text Available We provide general analysis of electro-break up process of compound scalar system. We use covariant approach with conserved EM current, which gives the ability to include strong interaction into QED. Therefore, we receive the ability to describe disintegration processes on nonlocal matter fields applying standard Feynman rules of QED. Inclusion of phase exponent into wave function receives a physical sense while we deal with the dominance of strong interaction in the process. We apply Green’s function (GF formalism to describe disintegration processes. Generalized gauge invariant electro-break up process amplitude is considered. One is a sum of traditional pole series and the regular part. We explore the deposits of regular part of amplitude, and its physical sense. A transition from virtual to real photon considered in photon point limit. The general analysis for electro-break up process of component scalar system is given. Precisely conserved nuclear electromagnetic currents at arbitrary square of transited momentum are received. The only undefined quantity in theory is vertex function. Therefore, we have the opportunity to describe electron scattering processes taking into account minimal necessary set of parameters.

  7. Electron scattering disintegration processes on light nuclei in covariant approach (United States)

    Kuznietsov, P. E.; Kasatkin, Yu. A.; Klepikov, V. F.


    We provide general analysis of electro-break up process of compound scalar system. We use covariant approach with conserved EM current, which gives the ability to include strong interaction into QED. Therefore, we receive the ability to describe disintegration processes on nonlocal matter fields applying standard Feynman rules of QED. Inclusion of phase exponent into wave function receives a physical sense while we deal with the dominance of strong interaction in the process. We apply Green's function (GF) formalism to describe disintegration processes. Generalized gauge invariant electro-break up process amplitude is considered. One is a sum of traditional pole series and the regular part. We explore the deposits of regular part of amplitude, and its physical sense. A transition from virtual to real photon considered in photon point limit. The general analysis for electro-break up process of component scalar system is given. Precisely conserved nuclear electromagnetic currents at arbitrary square of transited momentum are received. The only undefined quantity in theory is vertex function. Therefore, we have the opportunity to describe electron scattering processes taking into account minimal necessary set of parameters.

  8. Formation of the angular dependence of intensity of the light scattered on the optically dense atomic ensemble

    Directory of Open Access Journals (Sweden)

    Nikolay V. Larionov


    Full Text Available The probe light scattering on the cold optically dense atomic ensemble is studied theoretically in the paper. In order to describe multiple scattering of light in the context of quantum electrodynamics, the Konstantinov–Perel–Keldysh diagram technique has been used. This technique allows to rewrite the considered case of light scattering in terms of diagram series where each term describes incoherent scattering of certain order. Decoding these terms allowed us to obtain the explicit analytical expression for the cross-section of multiple incoherent scattering for the case of stationary two-level atoms (transition Jg = 0 → Je = 1. The numerical analysis of this expression carried out by applying the Monte-Carlo simulation made it possible to find an influence of different orders of scattering on forming the angular dependence of scattered light intensity.

  9. Scattered-Light Echoes from the Historical Galactic Supernovae Cassiopeia A and Tycho (SN 1572)

    Energy Technology Data Exchange (ETDEWEB)

    Rest, A; Welch, D L; Suntzeff, N B; Oaster, L; Lanning, H; Olsen, K; Smith, R C; Becker, A C; Bergmann, M; Challis, P; Clocchiatti, A; Cook, K H; Damke, G; Garg, A; Huber, M E; Matheson, T; Minniti, D; Prieto, J L; Wood-Vasey, W M


    We report the discovery of an extensive system of scattered light echo arclets associated with the recent supernovae in the local neighborhood of the Milky Way: Tycho (SN 1572) and Cassiopeia A. Existing work suggests that the Tycho SN was a thermonuclear explosion while the Cas A supernova was a core collapse explosion. Precise classifications according to modern nomenclature require spectra of the outburst light. In the case of ancient SNe, this can only be done with spectroscopy of their light echo, where the discovery of the light echoes from the outburst light is the first step. Adjacent light echo positions suggest that Cas A and Tycho may share common scattering dust structures. If so, it is possible to measure precise distances between historical Galactic supernovae. On-going surveys that alert on the development of bright scattered-light echo features have the potential to reveal detailed spectroscopic information for many recent Galactic supernovae, both directly visible and obscured by dust in the Galactic plane.

  10. Advanced Light Management Approaches for Thin-Film Silicon Solar Cells

    NARCIS (Netherlands)

    Zeman, M.; Isabella, O.; Jäger, K.; Santbergen, R.; Solntsev, S.; Topic, M.; Krc, J.


    Light management is important for improving the performance of thin-film solar cells. Advanced concepts of efficient light scattering and trapping inside the cell structures need to be investigated. An important tool for design and optimisation of the concepts present optical modelling and

  11. Influence of nearly resonant light on the scattering length in low-temperature atomic gases

    CERN Document Server

    Fedichev, P O; Shlyapnikov, G V; Walraven, J T M


    We develop the idea of manipulating the scattering length a in low-temperature atomic gases by using nearly resonant light. As found, if the incident light is close to resonance with one of the bound p levels of electronically excited molecule, then virtual radiative transitions of a pair of interacting atoms to this level can significantly change the value and even reverse the sign of a. The decay of the gas due to photon recoil, resulting from the scattering of light by single atoms, and due to photoassociation can be minimized by selecting the frequency detuning and the Rabi frequency. Our calculations show the feasibility of optical manipulations of trapped Bose condensates through a light-induced change in the mean field interaction between atoms, which is illustrated for ^7Li.

  12. Characterization of uranium corrosion product colloids by dynamic light scattering.

    Energy Technology Data Exchange (ETDEWEB)

    Mertz, C.; Bowers, D.; Goldberg, M.; Shelton-Davis, C.


    The Department of Energy plans to dispose of approximately 2100 metric tons of spent metallic uranium fuel in the mined repository at Yucca Mountain. Laboratory studies at Argonne National Laboratory have shown that corrosion of metallic uranium fuel with groundwater generates significant quantities of stable colloids. This finding is considered very important in light of the recent report (1) of rapid subsurface transport of radionuclides at the Nevada Test Site via colloids. Thus, sparingly soluble radionuclides can be transported with the colloids through the subsurface aqueous environment to much greater distances than is predicted based on the aqueous volubility of the radionuclides alone. Accordingly, characterization of colloids generated by fuel corrosion is necessary for assessing the long-term fate and transport of radionuclides in the repository environment.

  13. Light scattering, straylight, and optical quality in hydrophobic acrylic intraocular lenses with subsurface nanoglistenings. (United States)

    Werner, Liliana; Stover, John C; Schwiegerling, Jim; Das, Kamal K


    To evaluate forward light scattering and straylight in single-piece hydrophobic acrylic intraocular lenses (IOLs) (Acrysof) removed from cadaver eyes and design- and power-matched controls, as well as the effect of subsurface nanoglistenings on other optical quality and performance indicators. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Seventeen single-piece IOLs (11 blue light-filtering; 6 without blue-light filter) with subsurface nanoglistenings were removed from cadaver eyes. The Complete Angle Scatter Instrument scatterometer was used to measure the forward-scattered light; straylight values at various angles were calculated. The modulation transfer function (MTF) and Badal images were also obtained. Backscatter was measured with a Scheimpflug camera (EAS-1000) and light transmittance with a spectrophotometer (Lambda 35 UV-VIS) to confirm findings in previous studies. The mean straylight values at a scattered angle of 10 degrees were 1.06 ± 0.23 log(s) for blue light-filtering IOLs, 0.97 ± 0.28 log(s) for IOLs without a blue-light filter, and 0.22 ± 0.22 log(s) for controls. The MTF and Badal image contrast of IOLs removed from cadaver eyes were similar to control values (no subsurface nanoglistenings). Backscatter was significantly higher in IOLs from cadaver eyes, although light transmittance was similar to that of controls. Straylight in hydrophobic IOLs resulting from subsurface nanoglistenings was well below the value of straylight hindrance and would not cause noticeable visual impairments. Dr. Das is an employee of Alcon Laboratories, Inc. The Complete Angle Instrument scatterometer was developed by Dr. Stover at the Scatterworks, Inc. Neither of the other authors has a financial or proprietary interest in any method or material mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  14. Multiple scattering of polarized light in birefringent slab media: experimental verifications and simulations. (United States)

    Otsuki, Soichi


    The effective scattering Mueller matrices were measured for backward and forward scattering by applying a narrow polarized light on a polyacrylamide slab gel, which was strained vertically to generate birefringence inside. Monte Carlo simulations were performed in conditions that were the same as possible. The measured and simulated matrices were simplified to the reduced ones. They agreed well in both original and reduced forms. While they approximately take reciprocal forms for backward scattering, they approximately satisfy matrix forms that correspond to a reciprocal position of the mirror image for forward scattering. The reduced matrices were factorized by the Lu-Chipman polar decomposition to obtain the polarization parameters. The polarization parameters were in good agreement between the measurement and simulation and showed characteristic features of anisotropic slab media with a birefringence axis parallel to the slab surface.

  15. High Precision Stokes Polarimetry for Scattering Light using Wide Dynamic Range Intensity Detector

    Directory of Open Access Journals (Sweden)

    Shibata Shuhei


    Full Text Available This paper proposes a Stokes polarimetry for scattering light from a sample surface. To achieve a high accuracy measurement two approaches of an intensity detector and analysis algorism of a Stokes parameter were proposed. The dynamic range of this detector can achieve up to 1010 by combination of change of neutral-density (ND filters having different density and photon counting units. Stokes parameters can be measured by dual rotating of a retarder and an analyzer. The algorism of dual rotating polarimeter can be calibrated small linear diattenuation and linear retardance error of the retarder. This system can measured Stokes parameters from −20° to 70° of its scattering angle. It is possible to measure Stokes parameters of scattering of dust and scratch of optical device with high precision. This paper shows accuracy of this system, checking the polarization change of scattering angle and influence of beam size.

  16. Observation of mean path length invariance in light-scattering media. (United States)

    Savo, Romolo; Pierrat, Romain; Najar, Ulysse; Carminati, Rémi; Rotter, Stefan; Gigan, Sylvain


    The microstructure of a medium strongly influences how light propagates through it. The amount of disorder it contains determines whether the medium is transparent or opaque. Theory predicts that exciting such a medium homogeneously and isotropically makes some of its optical properties depend only on the medium's outer geometry. Here, we report an optical experiment demonstrating that the mean path length of light is invariant with respect to the microstructure of the medium it scatters through. Using colloidal solutions with varying concentration and particle size, the invariance of the mean path length is observed over nearly two orders of magnitude in scattering strength. Our results can be extended to a wide range of systems-however ordered, correlated, or disordered-and apply to all wave-scattering problems. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  17. Differing self-similarity in light scattering spectra: A potential tool for pre-cancer detection

    CERN Document Server

    Ghosh, Sayantan; Purwar, Harsh; Jagtap, Jaidip; Pradhan, Asima; Ghosh, Nirmalya; Panigrahi, Prasanta K


    The fluctuations in the elastic light scattering spectra of normal and dysplastic human cervical tissues analyzed through wavelet transform based techniques reveal clear signatures of self-similar behavior in the spectral fluctuations. Significant differences in the power law behavior ascertained through the scaling exponent was observed in these tissues. The strong dependence of the elastic light scattering on the size distribution of the scatterers manifests in the angular variation of the scaling exponent. Interestingly, the spectral fluctuations in both these tissues showed multi-fractality (non-stationarity in fluctuations), the degree of multi-fractality being marginally higher in the case of dysplastic tissues. These findings using the multi-resolution analysis capability of the discrete wavelet transform can contribute to the recent surge in the exploration for non-invasive optical tools for pre-cancer detection.

  18. A high-power spatial filter for Thomson scattering stray light reduction (United States)

    Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.


    The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.

  19. Out-of-plane light-scattering polarimetric imaging of a thread surface (United States)

    Liu, Cheng-Yang; Chang, Li-Jen


    A novel polarimetric measurement based on hemispherical light-scattering for the assessment of superficial screw is presented. The optical system is capable of capturing polarized light images. The effect of the thread surface backscattering is estimated with the use of in-plane and out-of-plane illumination. The angular distributions of polarized light scattered by the ISO metric screws are measured for light incident from a green laser. A partial Stokes vector imaging detector is mounted on a motorized rotating arm at an oblique angle to the sample normal and consists of a 10-bit scientific camera, an object lens, and a polarizer. The partial Stokes vector images of light scattered towards the camera are generated for each direction and a useful decomposition of the partial Stokes vector is presented. The thread surface effects can be minimized using out-of-plane polarized illumination in conjunction with polarized images. The experimental result may provide a new polarized imaging technique for using visible light to inspect the key features of a screw in automated optical inspection system.

  20. White light photothermal lens spectrophotometer for the determination of absorption in scattering samples. (United States)

    Marcano, Aristides; Alvarado, Salvador; Meng, Junwei; Caballero, Daniel; Moares, Ernesto Marín; Edziah, Raymond


    We developed a pump-probe photothermal lens spectrophotometer that uses a broadband arc-lamp and a set of interference filters to provide tunable, nearly monochromatic radiation between 370 and 730 nm as the pump light source. This light is focused onto an absorbing sample, generating a photothermal lens of millimeter dimensions. A highly collimated monochromatic probe light from a low-power He-Ne laser interrogates the generated lens, yielding a photothermal signal proportional to the absorption of light. We measure the absorption spectra of scattering dye solutions using the device. We show that the spectra are not affected by the presence of scattering, confirming that the method only measures the absorption of light that results in generation of heat. By comparing the photothermal spectra with the usual absorption spectra determined using commercial transmission spectrophotometers, we estimate the quantum yield of scattering of the sample. We discuss applications of the device for spectroscopic characterization of samples such as blood and gold nanoparticles that exhibit a complex behavior upon interaction with light.

  1. A tissue-engineered 3D model of light scattering in atherosclerotic plaques (United States)

    Levitz, David; Hinds, Monica T.; Wang, Ruikang K.; Ma, Zhenhe; Ishii, Katsu; Tran, Noi; McCarty, Owen J. T.; Hanson, Stephen R.; Jacques, Steven L.


    The development of atherosclerotic plaques includes changes in the cellular and extracellular composition of the arterial wall. Although these changes in composition affect the manner in which light scatters in the vessel wall and thus affect any optical signal, experimentally determining how features of atherosclerosis affect optical signals has remained elusive. Using current tissue-engineering methods, we developed a 3D tissue construct model for assessing how certain features of atherosclerosis (the increased concentrations of lipids and macrophages) affect optical signals. The model is based on vascular tissue constructs made of smooth muscle cells (SMCs) and macrophages (M\\Fgr s) that are co-cultured inside a 3D scaffold matrix of collagen fibers with interspersed lipids. To make the scaffold matrix, powdered collagen was dissolved in acetic acid, homogenized, and neutralized by sequential dialyses to yield a soft gel of 2 μm thick collagen fibers in which cells were seeded. In "normal" constructs, only SMCs were seeded in the collagen gel; in "athero-like" constructs, both SMCs and M\\Fgr s (loaded or unloaded with lipid) were seeded in the gel. To demonstrate the use of this model, sets of slab-shaped normal and athero-like constructs were imaged by optical coherence tomography (OCT) and qualitatively analyzed. 2D frames from 3D OCT image cubes were compared to 2D histology sections. Our results indicate that the cellular composition of the construct affects morphological features of the OCT image.

  2. Wavelength dependence of light diffusion in strongly scattering macroporous gallium phosphide

    NARCIS (Netherlands)

    Peeters, W.H.; Vellekoop, Ivo Micha; Mosk, Allard; Lagendijk, Aart


    We present time-resolved measurements of light transport through strongly scattering macroporous gallium phosphide at various vacuum wavelengths between 705 nm and 855 nm. Within this range the transport mean free path is strongly wavelength dependent, whereas the observed energy velocity is shown

  3. Relative contribution of submicron and supermicron particles to aerosol light scattering in the marine boundary layer

    NARCIS (Netherlands)

    Kleefeld, C.; O'Dowd, C.D.; O'Reilly, S.; Jennings, S.G.; Aalto, P.; Becker, E.; Kunz, G.J.; Leeuw, G. de


    Measurements of the aerosol light scattering coefficient (σsp) at a wavelength of λ - 550 nm were conducted at a coastal atmospheric research station in the east Atlantic Ocean during June 1999. Size distribution measurements between diameters of 3 nm and 40 um (at ambient humidity) were used to

  4. Scattering of light by a periodic structure in the presence of ...

    Indian Academy of Sciences (India)

    The earlier prediction, before our technique was introduced, had placed the limit of detection, by intensity measurements alone, at (0/) ∼ 0.33, where 0 is the coherence length of light for scattering by the rough part of the surface and is the wavelength of the periodic part of the surface. In our earlier works we have ...

  5. Light scattering changes follow evoked potentials from hippocampal Schaeffer collateral stimulation

    DEFF Research Database (Denmark)

    Rector, D M; Poe, G R; Kristensen, Morten Pilgaard


    We assessed relationships of evoked electrical and light scattering changes from cat dorsal hippocampus following Schaeffer collateral stimulation. Under anesthesia, eight stimulating electrodes were placed in the left hippocampal CA field and an optic probe, coupled to a photodiode or a charge-c...


    NARCIS (Netherlands)

    ZIJP, [No Value; TENBOSCH, JJ


    The scattering phase functions for HeNe-laser light of dentine sections 10-20-mu-m thick were measured. The functions perpendicular to the tubules had first-order maxima at angles of 4-degrees for bovine dentine and 5-degrees for human dentine; those parallel to the tubules showed no first-order

  7. Protein Analysis by Dynamic Light Scattering: Methods and Techniques for Students (United States)

    Lorber, Bernard; Fischer, Frederic; Bailly, Marc; Roy, Herve; Kern, Daniel


    Dynamic light scattering (DLS) analyses are routinely used in biology laboratories to detect aggregates in macromolecular solutions, to determine the size of proteins, nucleic acids, and complexes or to monitor the binding of ligands. This article is written for graduate and undergraduate students with access to DLS and for faculty members who…

  8. Autocorrelation function of scattered light for a binary fluid near the critical mixing point (United States)

    Bendjaballah, C.


    A time-to-amplitude conversion technique was applied to measure the second-order autocorrelation function of light scattering by a binary fluid from concentration fluctuations of the fluid very close to the critical point. The experimental setup included two photomultipliers, a time-to-amplitude converter, and a pulse height analyzer.

  9. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, Anna; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.


    A low coherence Mach–Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scatteredphotons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  10. Pretransitional phenomena of a colloid polymer mixture studied with static and dynamic light scattering

    NARCIS (Netherlands)

    Bodnár, I.; Dhont, J.K.G.; Lekkerkerker, H.N.W.


    A mixture of hard-sphere colloidal silica particles (radius 48 nm) and a nonadsorbing polymer (poly-(dimethylsiloxane), radius of gyration 23 nm) is studied by means of static and dynamic light scattering near the binodal. The spinodal is determined from an extrapolation of the diffusion

  11. Interaction between Humic Acid and Lysozyme, Studied by Dynamic Light Scattering and Isothermal Titration Calorimetry

    NARCIS (Netherlands)

    Tan, Wen Feng; Koopal, Luuk K.; Norde, Willem


    Interactions of purified Aldrich humic acid (PAHA) with the protein lysozyme (LSZ) are studied with dynamic light scattering and isothermal titration calorimetry by mixing LSZ and PAHA at various mass ratios. In solution LSZ is positive and PAHA is negative at the investigated pH values. Up to

  12. Experimental light scattering by fluffy aggregates of magnesiosilica, ferrosilica, and alumina cosmic dust analogs

    NARCIS (Netherlands)

    Volten, H.; Muñoz, O.; Hovenier, J.W.; Rietmeijer, F.J.M.; Nuth, J.A.; Waters, L.B.F.M.; van der Zande, W.J.


    Context: Fluffy aggregates are generally assumed to be important constituents of circumstellar and interplanetary environments as well as to be present among the solid debris ejected from active comets. Aims: We experimentally study light scattering properties of several fluffy aggregate samples.

  13. Light Scattering of TiO2 Nanoparticles Embedded in Polyurethane

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Canulescu, Stela; Johansen, Villads Egede

    A new approach of enhancing light scattering in polyurethane polymer through the effect of TiO2 nanoparticles (NP) is explored. The TiO2 NP with sizes of 360 nm, 410 nm and 500 nm were dispersed in polyurethane polymer in concentrations ranging from 0.25 wt% up to 2 wt%. Reflectivity and UV...

  14. Light-scattering properties of undiluted human blood subjected to simple shear

    NARCIS (Netherlands)

    Steenbergen, Wiendelt; Kolkman, R.G.M.; de Mul, F.F.M.


    An experimental investigation was performed into the effect of simple shear on the light-scattering properties of undiluted human blood. Undiluted human blood was enclosed between two glass plates with an adjustable separation between 30 and 120 mm and with one plate moving parallel to the other.

  15. Concentrated, polydisperse solutions of colloidal particles. Light scattering and sedimentation of hard-sphere mixture

    NARCIS (Netherlands)

    Vrij, A.


    The usefulness of the hard-sphere model in characterizing polydispersity in concentrated colloidal solutions is stressed. A recently derived equation for (∂ρi/∂μj)μ is used to give a simpler route for application to light scattering and sedimentation in multicomponent and polydisperse systems. Some


    NARCIS (Netherlands)



    The reduced scattering cross section per unit of volume SIGMA(s)' = SIGMA(s)(1 - g) is an important parameter to describe light propagation in media with scattering and absorption. Mie calculations of the asymmetry factor g for nonabsorbing spheres and Q(sca), the ratio of the scattering cross

  17. Mathematical and computational aspects of quaternary liquid mixing free energy measurement using light scattering. (United States)

    Wahle, Chris W; Ross, David S; Thurston, George M


    We provide a mathematical and computational analysis of light scattering measurement of mixing free energies of quaternary isotropic liquids. In previous work, we analyzed mathematical and experimental design considerations for the ternary mixture case [D. Ross, G. Thurston, and C. Lutzer, J. Chem. Phys. 129, 064106 (2008); C. Wahle, D. Ross, and G. Thurston, J. Chem. Phys. 137, 034201 (2012)]. Here, we review and introduce dimension-free general formulations of the fully nonlinear partial differential equation (PDE) and its linearization, a basis for applying the method to composition spaces of any dimension, in principle. With numerical analysis of the PDE as applied to the light scattering implied by a test free energy and dielectric gradient combination, we show that values of the Rayleigh ratio within the quaternary composition tetrahedron can be used to correctly reconstruct the composition dependence of the free energy. We then extend the analysis to the case of a finite number of data points, measured with noise. In this context the linearized PDE describes the relevant diffusion of information from light scattering noise to the free energy. The fully nonlinear PDE creates a special set of curves in the composition tetrahedron, collections of which form characteristics of the nonlinear and linear PDEs, and we show that the information diffusion has a time-like direction along the positive normals to these curves. With use of Monte Carlo simulations of light scattering experiments, we find that for a modest laboratory light scattering setup, about 100-200 samples and 100 s of measurement time are enough to be able to measure the mixing free energy over the entire quaternary composition tetrahedron, to within an L(2) error norm of 10(-3). The present method can help quantify thermodynamics of quaternary isotropic liquid mixtures.

  18. Study of the scattering of the light in aqueous samples collagen in the presence of nanoparticles and curcuma pigment (United States)

    Silva, F. M. L.; Alencar, L. D. S.; Bernardi, M. I. B.; Lima, F. W. S.; Melo, C. A. S.


    In this work we investigate the scattering of light in means turbid in the presence or not of pigment and nanoparticles. For this we initially using a sample of collagen from means turbid with and without the presence of curcuma pigments and nanoparticles. Our results show that the light scattering is more intense in the samples with nanoparticles and curcuma pigment.

  19. Smectic ordering in nematic and smectic liquid-crystalline films probed by means of surface light scattering

    NARCIS (Netherlands)

    Böttger, A.; Frenkel, D.; Joosten, J.G.H.; Krooshof, G.


    We present the first results of experiments that measure the intensity of light scattered by capillary waves on the surface of free-standing liquid-crystalline thin films. The intensity of the scattered light provides information about the surface tension of the liquid-air interfaces and, more

  20. Improved thin film solar cell with Rayleigh scattering in porous silicon pipes

    Energy Technology Data Exchange (ETDEWEB)

    Skryshevsky, V.A.; Laugier, A. (Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France). Lab. de Physique de la Matiere)


    The development of thin film solar cells on cheap substrates requires new approaches to enhance the cell efficiency. In the present work we analyse solar cells with porous silicon diffusor arrays in the form of pipes within the deposited silicon layer. The contribution of Rayleigh scattering on full randomized nanosize crystallites of porous silicon pipes to the cell efficiency was simulated depending on the pipe geometry, their depth in the silicon film, surface recombination rate and diffusion length. The simulation shows that the efficiency improvement, due to the performance of light trapping, achieves significant values at the technical attainable characteristics of the porous layer. The effect of light trapping increases with the insertion of pipe arrays close to the rear side of the cell and for Si films having a low diffusion length. The work states that the geometric dimensions of pipes drastically alter the benefit of this cell design. (orig.) 20 refs.

  1. Archean Earth Atmosphere Fractal Haze Aggregates: Light Scattering Calculations and the Faint Young Sun Paradox (United States)

    Boness, D. A.; Terrell-Martinez, B.


    As part of an ongoing undergraduate research project of light scattering calculations involving fractal carbonaceous soot aggregates relevant to current anthropogenic and natural sources in Earth's atmosphere, we have read with interest a recent paper [E.T. Wolf and O.B Toon,Science 328, 1266 (2010)] claiming that the Faint Young Sun paradox discussed four decades ago by Carl Sagan and others can be resolved without invoking heavy CO2 concentrations as a greenhouse gas warming the early Earth enough to sustain liquid water and hence allow the origin of life. Wolf and Toon report that a Titan-like Archean Earth haze, with a fractal haze aggregate nature due to nitrogen-methane photochemistry at high altitudes, should block enough UV light to protect the warming greenhouse gas NH3 while allowing enough visible light to reach the surface of the Earth. To test this hypothesis, we have employed a rigorous T-Matrix arbitrary-particle light scattering technique, to avoid the simplifications inherent in Mie-sphere scattering, on haze fractal aggregates at UV and visible wavelenths of incident light. We generate these model aggregates using diffusion-limited cluster aggregation (DLCA) algorithms, which much more closely fit actual haze fractal aggregates than do diffusion-limited aggregation (DLA) algorithms.

  2. Focusing light through scattering media by polarization modulation based generalized digital optical phase conjugation (United States)

    Yang, Jiamiao; Shen, Yuecheng; Liu, Yan; Hemphill, Ashton S.; Wang, Lihong V.


    Optical scattering prevents light from being focused through thick biological tissue at depths greater than ˜1 mm. To break this optical diffusion limit, digital optical phase conjugation (DOPC) based wavefront shaping techniques are being actively developed. Previous DOPC systems employed spatial light modulators that modulated either the phase or the amplitude of the conjugate light field. Here, we achieve optical focusing through scattering media by using polarization modulation based generalized DOPC. First, we describe an algorithm to extract the polarization map from the measured scattered field. Then, we validate the algorithm through numerical simulations and find that the focusing contrast achieved by polarization modulation is similar to that achieved by phase modulation. Finally, we build a system using an inexpensive twisted nematic liquid crystal based spatial light modulator (SLM) and experimentally demonstrate light focusing through 3-mm thick chicken breast tissue. Since the polarization modulation based SLMs are widely used in displays and are having more and more pixel counts with the prevalence of 4 K displays, these SLMs are inexpensive and valuable devices for wavefront shaping.

  3. Stimulated-emission-depletion microscopy with a multicolor stimulated-Raman-scattering light source. (United States)

    Rankin, Brian R; Kellner, Robert R; Hell, Stefan W


    We describe a subdiffraction-resolution far-field fluorescence microscope employing stimulated emission depletion (STED) with a light source consisting of a microchip laser coupled into a standard single-mode fiber, which, via stimulated Raman scattering (SRS), yields a comb-like spectrum of seven discrete peaks extending from the fundamental wavelength at 532 nm to 620 nm. Each of the spectral peaks can be used as STED light for overcoming the diffraction barrier. This SRS light source enables the simple implementation of multicolor STED and provides a spectral output with multiple available wavelengths from green to red with potential for further expansion.

  4. Light comfort zones of mesopelagic acoustic scattering layers in two contrasting optical environments

    KAUST Repository

    Røstad, Anders


    We make a comparison of the mesopelagic sound scattering layers (SLs) in two contrasting optical environments; the clear Red Sea and in murkier coastal waters of Norway (Masfjorden). The depth distributions of the SL in Masfjorden are shallower and narrower than those of the Red Sea. This difference in depth distribution is consistent with the hypothesis that the organisms of the SL distribute according to similar light comfort zones (LCZ) in the two environments. Our study suggest that surface and underwater light measurements ranging more than10 orders of magnitude is required to assess the controlling effects of light on SL structure and dynamics.

  5. Near-field imaging of out-of-plane light scattering in photonic crystal slabs

    DEFF Research Database (Denmark)

    Volkov, Valentyn; Bozhevolnyi, Sergey; Taillaert, Dirk


    A collection scanning near-field optical microscope (SNOM) is used to image the propagating of light at telecommunication wavelengths (1520-1570 nm) along photonic crystal (PC) slabs, which combine slab waveguides with in-plane PCs consisting of one- and two-dimensional gratings. The efficient out......-of-plane light scattering is directly observed for both 1D and 2D gratings (period 590 nm) fabricated on silicon-on-insulator wafers and the corresponding SNOM images are presented. Using the obtained SNOM images, we analyze light intensity distributions along PC gratings measured at different wavelengths and...

  6. Anomalous diffraction approximation to the light scattering coefficient spectra of marine particles with power-law size distribution. (United States)

    Matciak, Maciej


    Based on anomalous diffraction approximation, analytical expressions for the scattering coefficient of marine particles with power-law size distribution in the infinite domain of sizes (0, ∞) were derived. Comparison with the exact Mie solution for the light scattering by spheres indicated that the obtained expressions can describe the relative spectral variability of the scattering coefficient well. This is demonstrated and discussed for the scattering spectra of main types of marine particulates characterized by different optical properties.

  7. Light Scattering Strategy for the Investigation of Time-Evolving Heterogeneous Supramolecular Self-Assemblies (United States)

    Jouault, Nicolas; Moulin, Emilie; Giuseppone, Nicolas; Buhler, Eric


    Supramolecular self-assembly is a multiple length-scale and time-dependent process involving many coexisting components. Such complexity requires suitable strategies to extract quantitative dynamical and structural information on all involved species. Here, we detail an original light scattering method to study the kinetics of tailored triarylamine molecules capable of self-assembling in supramolecular highly conductive nanowires upon light exposure. These micrometric assemblies cause the emergence of intermittences in the scattered intensity and the construction of a predominant slow mode in the correlation function making separation between small-and large-size species impossible using conventional treatments. Our strategy is based on the time monitoring of intermittences and allows us to determine the fraction of nanowires as well as those of small critical nuclei and triarylamine building blocks as a function of time and light exposure, in good agreement with recent theoretical predictions.

  8. The spectral energy distribution of the scattered light from dark clouds (United States)

    Mattila, Kalevi; Schnur, G. F. O.


    A dark cloud is exposed to the ambient radiation field of integrated starlight in the Galaxy. Scattering of starlight by the dust particles gives rise to a diffuse surface brightness of the dark nebula. The intensity and the spectrum of this diffuse radiation can be used to investigate, e.g., the scattering parameters of the dust, the optical thickness of the cloud, and as a probe of the ambient radiation field at the location of the cloud. An understanding of the scattering process is also a prerequisite for the isolation of broad spectral features due to fluorescence or to any other non-scattering origin of the diffuse light. Model calculations are presented for multiple scattering in a spherical cloud. These calculations show that the different spectral shapes of the observed diffuse light can be reproduced with standard dust parameters. The possibility to use the observed spectrum as a diagnostic tool for analyzing the thickness of the cloud and the dust particle is discussed.

  9. Silver nanoparticles on nanopatterned LiF(110) surface studied by extreme ultraviolet light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Giglia, Angelo, E-mail:; Nannarone, Stefano [Istituto Officina dei Materiali - Consiglio Nazionale delle Ricerche, Laboratorio Tecnologie Avanzate e NanoSCienza, Area Science Park Basovizza, S.S. 14 Km 163.5, 34149 Trieste (Italy); Miotti, Paolo [Istituto di Fotonica e Nanotecnologie - Consiglio Nazionale delle Ricerche, Via Trasea 7, 35131 Padova (Italy); Parisse, Pietro [Sincrotrone Trieste S.C.p.A., S.S. 14 km 163.5, 34149 Basovizza, Trieste (Italy)


    A LiF(110) surface featuring a ridge-and-valley nanopatterned structure periodic along the [−1,1,0] direction (period and height of the order of 30 nm and 10 nm, respectively) formed by [001] macrosteps exposing (100) and (010) facets was functionalized by rows of Ag nanoparticles and studied by elastic light scattering in the energy range 50–100 eV. Families of diffraction efficiencies curves were taken at grazing incidence angle and fixed photon energy as a function of scattering angle, and elastic scattering curves were taken at fixed scattering angle as a function of energy. The scattering curves presented well-defined features ascribable to the periodicities of the surface, or equivalently to the reciprocal q{sub X} vectors correlated with the power spectral density features of topological images of atomic force microscopy. Other characteristics of the functionalized surface, including the height of ridge-valley profile, the Ag nanoparticle dimensions, and the material distribution in the scattering plane, were obtained by fitting the experimental zero and first order efficiency curves to simulation results of a parameterized model. The simulations were carried out adapting an in-house code based on the electromagnetic differential method, and the different material properties were taken into account by a space dependent complex dielectric constant. Information along the direction perpendicular to the scattering plane was not accessible but morphological insights were obtained combining light diffraction with atomic force microscopy. The results indicate nanoparticles with a quasi-ellipsoidal shape prolate along the ridge direction with minor and major axes of ∼12 nm and ∼21 nm, respectively.

  10. Microscopic theory of linear light scattering from mesoscopic media and in near-field optics. (United States)

    Keller, Ole


    On the basis of quantum mechanical response theory a microscopic propagator theory of linear light scattering from mesoscopic systems is presented. The central integral equation problem is transferred to a matrix equation problem by discretization in transitions between pairs of (many-body) energy eigenstates. The local-field calculation which appears from this approach is valid down to the microscopic region. Previous theories based on the (macroscopic) dielectric constant concept make use of spatial (geometrical) discretization and cannot in general be trusted on the mesoscopic length scale. The present theory can be applied to light scattering studies in near-field optics. After a brief discussion of the macroscopic integral equation problem a microscopic potential description of the scattering process is established. In combination with the use of microscopic electromagnetic propagators the formalism allows one to make contact to the macroscopic theory of light scattering and to the spatial photon localization problem. The quantum structure of the microscopic conductivity response tensor enables one to establish a clear physical picture of the origin of local-field phenomena in mesoscopic and near-field optics. The Huygens scalar propagator formalism is revisited and its generality in microscopic physics pointed out.

  11. Long-term effect of surface light scattering and glistenings of intraocular lenses on visual function. (United States)

    Hayashi, Ken; Hirata, Akira; Yoshida, Motoaki; Yoshimura, Koichi; Hayashi, Hideyuki


    To investigate the long-term effect of surface light scattering and glistenings of various intraocular lenses (IOLs) on visual function and optical aberrations after cataract surgery. Case-control study. Thirty-five eyes that underwent implantation of a hydrophobic acrylic, silicone, or polymethyl methacrylate (PMMA) IOL more than 10 years ago were recruited. The scattering light intensity of the surface and internal matrix of the optic was measured using Scheimpflug photography. Visual acuity (VA) was measured using VA charts, and contrast VA and that with glare (glare VA) were examined using a contrast sensitivity tester. Ocular higher-order aberrations (HOAs) were measured using a Hartmann-Shack aberrometer. Mean scattering light intensity of the surface and internal matrix of the optic was significantly higher in the acrylic group than in the silicone and PMMA groups (P ocular and internal optic HOAs in the acrylic group. At more than 10 years postoperatively, visual function, including contrast sensitivity, and ocular HOAs were comparable among eyes that received acrylic, silicone, and PMMA IOLs. Surface scattering and glistenings with the acrylic IOLs were not significantly correlated with visual function and optical aberrations. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Light scattering optimization of chitin random network in ultrawhite beetle scales (United States)

    Utel, Francesco; Cortese, Lorenzo; Pattelli, Lorenzo; Burresi, Matteo; Vignolini, Silvia; Wiersma, Diederik


    Among the natural white colored photonics structures, a bio-system has become of great interest in the field of disordered optical media: the scale of the white beetle Chyphochilus. Despite its low thickness, on average 7 μm, and low refractive index, this beetle exhibits extreme high brightness and unique whiteness. These properties arise from the interaction of light with a complex network of chitin nano filaments embedded in the interior of the scales. As it's been recently claimed, this could be a consequence of the peculiar morphology of the filaments network that, by means of high filling fraction (0.61) and structural anisotropy, optimizes the multiple scattering of light. We therefore performed a numerical analysis on the structural properties of the chitin network in order to understand their role in the enhancement of the scale scattering intensity. Modeling the filaments as interconnected rod shaped scattering centers, we numerically generated the spatial coordinates of the network components. Controlling the quantities that are claimed to play a fundamental role in the brightness and whiteness properties of the investigated system (filling fraction and average rods orientation, i.e. the anisotropy of the ensemble of scattering centers), we obtained a set of customized random networks. FDTD simulations of light transport have been performed on these systems, observing high reflectance for all the visible frequencies and proving the implemented algorithm to numerically generate the structures is suitable to investigate the dependence of reflectance by anisotropy.

  13. Probing helium interfaces with light scattering: from fluid mechanics to statistical physics. (United States)

    Wolf, P E; Bonnet, F; Guyon, L; Lambert, T; Perraud, S; Puech, L; Rousset, B; Thibault, P


    We have investigated the formation of helium droplets in two physical situations. In the first one, droplets are atomised from superfluid or normal liquid by a fast helium vapour flow. In the second, droplets of normal liquid are formed inside porous glasses during the process of helium condensation. The context, aims, and results of these experiments are reviewed, with focus on the specificity of light scattering by helium. In particular, we discuss how, for different reasons, the closeness to unity of the index of refraction of helium allows in both cases to minimise the problem of multiple scattering and obtain results which it would not be possible to get using other fluids.

  14. 3D radiative transfer code for polarized scattered light with aligned grains (United States)

    Pelkonen, V.-M.; Penttilä, A.; Juvela, M.; Muinonen, K.


    We are working on a 3D Monte Carlo radiative transfer code which incorporates hierarchical grid structure (octree) and the full Stokes vector for both the incoming radiation and the radiation scattered by dust grains. The dust model can include different populations of dust, differing in composition, size distribution, shapes, and orientation. The non-spherical dust grains can be randomly aligned, or a fraction of them can be aligned with the magnetic fields (in particular, by the radiation field via radiative torques, RATs). The code will be a valuable tool in studying polarized scattered light from cometary comae in the solar system and from protoplanetary disks in the exoplanetary context.

  15. Evidence for light-by-light scattering in heavy-ion collisions with the ATLAS detector at the LHC (United States)

    Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S. H.; Abouzeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adamczyk, L.; Adelman, J.; Adersberger, M.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agheorghiesei, C.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akatsuka, S.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alshehri, A. A.; Alstaty, M.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antel, C.; Antonelli, M.; Antonov, A.; Antrim, D. J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Araujo Ferraz, V.; Arce, A. T. H.; Ardell, R. E.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Baines, J. T.; Bajic, M.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisits, M.-S.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska-Blenessy, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beermann, T. A.; Begalli, M.; Begel, M.; Behr, J. K.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernardi, G.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethani, A.; Bethke, S.; Bevan, A. J.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; Bilbao de Mendizabal, J.; Billoud, T. R. V.; Bilokon, H.; Bindi, M.; Bingul, A.; Bini, C.; Biondi, S.; Bisanz, T.; Bittrich, C.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blue, A.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bokan, P.; Bold, T.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Bossio Sola, J. D.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Briglin, D. L.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruni, L. S.; Brunt, B. H.; Bruschi, M.; Bruscino, N.; Bryant, P.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Buehrer, F.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burger, A. M.; Burghgrave, B.; Burka, K.; Burke, S.; Burmeister, I.; Burr, J. T. P.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Callea, G.; Caloba, L. P.; Calvente Lopez, S.; Calvet, D.; Calvet, S.; Calvet, T. P.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Camincher, C.; Campana, S.; Campanelli, M.; Camplani, A.; Campoverde, A.; Canale, V.; Cano Bret, M.; Cantero, J.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, I.; Carli, T.; Carlino, G.; Carlson, B. T.; Carminati, L.; Carney, R. M. D.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Casper, D. W.; Castelijn, R.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavallaro, E.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Celebi, E.; Ceradini, F.; Cerda Alberich, L.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, S. K.; Chan, W. S.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chatterjee, A.; Chau, C. C.; Chavez Barajas, C. A.; Che, S.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, H. J.; Cheng, Y.; Cheplakov, A.; Cheremushkina, E.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiarelli, G.; Chiodini, G.; Chisholm, A. S.; Chitan, A.; Chiu, Y. H.; Chizhov, M. V.; Choi, K.; Chomont, A. R.; Chouridou, S.; Chow, B. K. B.; Christodoulou, V.; Chromek-Burckhart, D.; Chu, M. C.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocca, C.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, M. R.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Colasurdo, L.; Cole, B.; Colijn, A. P.; Collot, J.; Colombo, T.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Consorti, V.; Constantinescu, S.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cormier, F.; Cormier, K. J. R.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crawley, S. J.; Creager, R. A.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cueto, A.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cúth, J.; Czirr, H.; Czodrowski, P.; D'Amen, G.; D'Auria, S.; D'Onofrio, M.; da Cunha Sargedas de Sousa, M. J.; da Via, C.; Dabrowski, W.; Dado, T.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Dang, N. P.; Daniells, A. C.; Dann, N. S.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Daubney, T.; Davey, W.; David, C.; Davidek, T.; Davies, M.; Davison, P.; Dawe, E.; Dawson, I.; de, K.; de Asmundis, R.; de Benedetti, A.; de Castro, S.; de Cecco, S.; de Groot, N.; de Jong, P.; de la Torre, H.; de Lorenzi, F.; de Maria, A.; de Pedis, D.; de Salvo, A.; de Sanctis, U.; de Santo, A.; de Vasconcelos Corga, K.; de Vivie de Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Dehghanian, N.; Deigaard, I.; Del Gaudio, M.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; Della Volpe, D.; Delmastro, M.; Delporte, C.; Delsart, P. A.; Demarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Denysiuk, D.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; di Ciaccio, A.; di Ciaccio, L.; di Clemente, W. K.; di Donato, C.; di Girolamo, A.; di Girolamo, B.; di Micco, B.; di Nardo, R.; di Petrillo, K. F.; di Simone, A.; di Sipio, R.; di Valentino, D.; Diaconu, C.; Diamond, M.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Díez Cornell, S.; Dimitrievska, A.; Dingfelder, J.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Djuvsland, J. I.; Do Vale, M. A. B.; Dobos, D.; Dobre, M.; Doglioni, C.; Dolejsi, J.; Dolezal, Z.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Drechsler, E.; Dris, M.; Du, Y.; Duarte-Campderros, J.; Duchovni, E.; Duckeck, G.; Ducourthial, A.; Ducu, O. A.; Duda, D.; Dudarev, A.; Dudder, A. Chr.; Duffield, E. M.; Duflot, L.; Dührssen, M.; Dumancic, M.; Dumitriu, A. E.; Duncan, A. K.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Durglishvili, A.; Duschinger, D.; Dutta, B.; Dyndal, M.; Eckardt, C.; Ecker, K. M.; Edgar, R. C.; Eifert, T.; Eigen, G.; Einsweiler, K.; Ekelof, T.; El Kacimi, M.; El Kosseifi, R.; Ellajosyula, V.; Ellert, M.; Elles, S.; Ellinghaus, F.; Elliot, A. A.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Ennis, J. S.; Erdmann, J.; Ereditato, A.; Ernis, G.; Ernst, M.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Ezhilov, A.; Fabbri, F.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Falla, R. J.; Faltova, J.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farina, C.; Farina, E. M.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Faucci Giannelli, M.; Favareto, A.; Fawcett, W. J.; Fayard, L.; Fedin, O. L.; Fedorko, W.; Feigl, S.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Feremenga, L.; Fernandez Martinez, P.; Fernandez Perez, S.; Ferrando, J.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Fischer, A.; Fischer, C.; Fischer, J.; Fisher, W. C.; Flaschel, N.; Fleck, I.; Fleischmann, P.; Fletcher, R. R. M.; Flick, T.; Flierl, B. M.; Flores Castillo, L. R.; Flowerdew, M. J.; Forcolin, G. T.; Formica, A.; Forti, A.; Foster, A. G.; Fournier, D.; Fox, H.; Fracchia, S.; Francavilla, P.; Franchini, M.; Franchino, S.; Francis, D.; Franconi, L.; Franklin, M.; Frate, M.; Fraternali, M.; Freeborn, D.; Fressard-Batraneanu, S. M.; Freund, B.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fusayasu, T.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gach, G. P.; Gadatsch, S.; Gadomski, S.; Gagliardi, G.; Gagnon, L. G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Ganguly, S.; Gao, J.; Gao, Y.; Gao, Y. S.; Garay Walls, F. M.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gascon Bravo, A.; Gasnikova, K.; Gatti, C.; Gaudiello, A.; Gaudio, G.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Gee, C. N. P.; Geisen, M.; Geisler, M. P.; Gellerstedt, K.; Gemme, C.; Genest, M. H.; Geng, C.; Gentile, S.; Gentsos, C.; George, S.; Gerbaudo, D.; Gershon, A.; Ghasemi, S.; Ghneimat, M.; Giacobbe, B.; Giagu, S.; Giannetti, P.; Gibson, S. M.; Gignac, M.; Gilchriese, M.; Gillberg, D.; Gilles, G.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giorgi, F. M.; Giraud, P. F.; Giromini, P.; Giugni, D.; Giuli, F.; Giuliani, C.; Giulini, M.; Gjelsten, B. K.; Gkaitatzis, S.; Gkialas, I.; Gkougkousis, E. L.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glaysher, P. C. F.; Glazov, A.; Goblirsch-Kolb, M.; Godlewski, J.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gonçalo, R.; Goncalves Gama, R.; Goncalves Pinto Firmino da Costa, J.; Gonella, G.; Gonella, L.; Gongadze, A.; González de La Hoz, S.; Gonzalez-Sevilla, S.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorini, B.; Gorini, E.; Gorišek, A.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Goudet, C. R.; Goujdami, D.; Goussiou, A. G.; Govender, N.; Gozani, E.; Graber, L.; Grabowska-Bold, I.; Gradin, P. O. J.; Gramling, J.; Gramstad, E.; Grancagnolo, S.; Gratchev, V.; Gravila, P. M.; Gray, H. M.; Greenwood, Z. D.; Grefe, C.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Grevtsov, K.; Griffiths, J.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grivaz, J.-F.; Groh, S.; Gross, E.; Grosse-Knetter, J.; Grossi, G. C.; Grout, Z. J.; Guan, L.; Guan, W.; Guenther, J.; Guescini, F.; Guest, D.; Gueta, O.; Gui, B.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gumpert, C.; Guo, J.; Guo, W.; Guo, Y.; Gupta, R.; Gupta, S.; Gustavino, G.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Gutschow, C.; Guyot, C.; Guzik, M. P.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haber, C.; Hadavand, H. K.; Hadef, A.; Hageböck, S.; Hagihara, M.; Hakobyan, H.; Haleem, M.; Haley, J.; Halladjian, G.; Hallewell, G. D.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamilton, A.; Hamity, G. N.; Hamnett, P. G.; Han, L.; Han, S.; Hanagaki, K.; Hanawa, K.; Hance, M.; Haney, B.; Hanke, P.; Hansen, J. B.; Hansen, J. D.; Hansen, M. C.; Hansen, P. H.; Hara, K.; Hard, A. S.; Harenberg, T.; Hariri, F.; Harkusha, S.; Harrington, R. D.; Harrison, P. F.; Hartjes, F.; Hartmann, N. M.; Hasegawa, M.; Hasegawa, Y.; Hasib, A.; Hassani, S.; Haug, S.; Hauser, R.; Hauswald, L.; Havener, L. B.; Havranek, M.; Hawkes, C. M.; Hawkings, R. J.; Hayakawa, D.; Hayden, D.; Hays, C. P.; Hays, J. M.; Hayward, H. S.; Haywood, S. J.; Head, S. J.; Heck, T.; Hedberg, V.; Heelan, L.; Heidegger, K. K.; Heim, S.; Heim, T.; Heinemann, B.; Heinrich, J. J.; Heinrich, L.; Heinz, C.; Hejbal, J.; Helary, L.; Held, A.; Hellman, S.; Helsens, C.; Henderson, J.; Henderson, R. C. W.; Heng, Y.; Henkelmann, S.; Correia, A. M. Henriques; Henrot-Versille, S.; Herbert, G. H.; Herde, H.; Herget, V.; Hernández Jiménez, Y.; Herten, G.; Hertenberger, R.; Hervas, L.; Herwig, T. C.; Hesketh, G. G.; Hessey, N. P.; Hetherly, J. W.; Higashino, S.; Higón-Rodriguez, E.; Hill, E.; Hill, J. C.; Hiller, K. H.; Hillier, S. J.; Hinchliffe, I.; Hirose, M.; Hirschbuehl, D.; Hiti, B.; Hladik, O.; Hoad, X.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoenig, F.; Hohn, D.; Holmes, T. R.; Homann, M.; Honda, S.; Honda, T.; Hong, T. M.; Hooberman, B. H.; Hopkins, W. H.; Horii, Y.; Horton, A. J.; Hostachy, J.-Y.; Hou, S.; Hoummada, A.; Howarth, J.; Hoya, J.; Hrabovsky, M.; Hristova, I.; Hrivnac, J.; Hryn'Ova, T.; Hrynevich, A.; Hsu, P. J.; Hsu, S.-C.; Hu, Q.; Hu, S.; Huang, Y.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Huhtinen, M.; Huo, P.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibragimov, I.; Iconomidou-Fayard, L.; Iengo, P.; Igonkina, O.; Iizawa, T.; Ikegami, Y.; Ikeno, M.; Ilchenko, Y.; Iliadis, D.; Ilic, N.; Introzzi, G.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Ishijima, N.; Ishino, M.; Ishitsuka, M.; Issever, C.; Istin, S.; Ito, F.; Iturbe Ponce, J. M.; Iuppa, R.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jabbar, S.; Jackson, P.; Jain, V.; Jakobi, K. B.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jamin, D. O.; Jana, D. K.; Jansky, R.; Janssen, J.; Janus, M.; Janus, P. A.; Jarlskog, G.; Javadov, N.; Javůrek, T.; Javurkova, M.; Jeanneau, F.; Jeanty, L.; Jejelava, J.; Jelinskas, A.; Jenni, P.; Jeske, C.; Jézéquel, S.; Ji, H.; Jia, J.; Jiang, H.; Jiang, Y.; Jiang, Z.; Jiggins, S.; Jimenez Pena, J.; Jin, S.; Jinaru, A.; Jinnouchi, O.; Jivan, H.; Johansson, P.; Johns, K. A.; Johnson, C. A.; Johnson, W. J.; Jon-And, K.; Jones, R. W. L.; Jones, S.; Jones, T. J.; Jongmanns, J.; Jorge, P. M.; Jovicevic, J.; Ju, X.; Juste Rozas, A.; Köhler, M. K.; Kaczmarska, A.; Kado, M.; Kagan, H.; Kagan, M.; Kahn, S. J.; Kaji, T.; Kajomovitz, E.; Kalderon, C. W.; Kaluza, A.; Kama, S.; Kamenshchikov, A.; Kanaya, N.; Kaneti, S.; Kanjir, L.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kaplan, L. S.; Kar, D.; Karakostas, K.; Karastathis, N.; Kareem, M. J.; Karentzos, E.; Karpov, S. N.; Karpova, Z. M.; Karthik, K.; Kartvelishvili, V.; Karyukhin, A. N.; Kasahara, K.; Kashif, L.; Kass, R. D.; Kastanas, A.; Kataoka, Y.; Kato, C.; Katre, A.; Katzy, J.; Kawade, K.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kay, E. F.; Kazanin, V. F.; Keeler, R.; Kehoe, R.; Keller, J. S.; Kempster, J. J.; Keoshkerian; Kepka, O.; Kerševan, B. P.; Kersten, S.; Keyes, R. A.; Khader, M.; Khalil-Zada, F.; Khanov, A.; Kharlamov, A. G.; Kharlamova, T.; Khodinov, A.; Khoo, T. J.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kido, S.; Kilby, C. R.; Kim, H. Y.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kind, O. M.; King, B. T.; Kirchmeier, D.; Kirk, J.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kiuchi, K.; Kivernyk, O.; Kladiva, E.; Klapdor-Kleingrothaus, T.; Klein, M. H.; Klein, M.; Klein, U.; Kleinknecht, K.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klingl, T.; Klioutchnikova, T.; Kluge, E.-E.; Kluit, P.; Kluth, S.; Knapik, J.; Kneringer, E.; Knoops, E. B. F. G.; Knue, A.; Kobayashi, A.; Kobayashi, D.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Koffas, T.; Koffeman, E.; Köhler, N. M.; Koi, T.; Kolb, M.; Koletsou, I.; Komar, A. A.; Komori, Y.; Kondo, T.; Kondrashova, N.; Köneke, K.; König, A. C.; Kono, T.; Konoplich, R.; Konstantinidis, N.; Kopeliansky, R.; Koperny, S.; Kopp, A. K.; Korcyl, K.; Kordas, K.; Korn, A.; Korol, A. A.; Korolkov, I.; Korolkova, E. V.; Kortner, O.; Kortner, S.; Kosek, T.; Kostyukhin, V. V.; Kotwal, A.; Koulouris, A.; Kourkoumeli-Charalampidi, A.; Kourkoumelis, C.; Kourlitis, E.; Kouskoura, V.; Kowalewska, A. B.; Kowalewski, R.; Kowalski, T. Z.; Kozakai, C.; Kozanecki, W.; Kozhin, A. S.; Kramarenko, V. A.; Kramberger, G.; Krasnopevtsev, D.; Krasznahorkay, A.; Krauss, D.; Kravchenko, A.; Kremer, J. A.; Kretz, M.; Kretzschmar, J.; Kreutzfeldt, K.; Krieger, P.; Krizka, K.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Krumnack, N.; Kruse, M. C.; Kruskal, M.; Kubota, T.; Kucuk, H.; Kuday, S.; Kuechler, J. T.; Kuehn, S.; Kugel, A.; Kuger, F.; Kuhl, T.; Kukhtin, V.; Kukla, R.; Kulchitsky, Y.; Kuleshov, S.; Kulinich, Y. P.; Kuna, M.; Kunigo, T.; Kupco, A.; Kuprash, O.; Kurashige, H.; Kurchaninov, L. L.; Kurochkin, Y. A.; Kurth, M. G.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; Kwan, T.; Kyriazopoulos, D.; La Rosa, A.; La Rosa Navarro, J. L.; La Rotonda, L.; Lacasta, C.; Lacava, F.; Lacey, J.; Lacker, H.; Lacour, D.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Lammers, S.; Lampl, W.; Lançon, E.; Landgraf, U.; Landon, M. P. J.; Lanfermann, M. C.; Lang, V. S.; Lange, J. C.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Lanza, A.; Lapertosa, A.; Laplace, S.; Laporte, J. F.; Lari, T.; Lasagni Manghi, F.; Lassnig, M.; Laurelli, P.; Lavrijsen, W.; Law, A. T.; Laycock, P.; Lazovich, T.; Lazzaroni, M.; Le, B.; Le Dortz, O.; Le Guirriec, E.; Le Quilleuc, E. P.; Leblanc, M.; Lecompte, T.; Ledroit-Guillon, F.; Lee, C. A.; Lee, S. C.; Lee, L.; Lefebvre, B.; Lefebvre, G.; Lefebvre, M.; Legger, F.; Leggett, C.; Lehan, A.; Lehmann Miotto, G.; Lei, X.; Leight, W. A.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Lemmer, B.; Leney, K. J. C.; Lenz, T.; Lenzi, B.; Leone, R.; Leone, S.; Leonidopoulos, C.; Lerner, G.; Leroy, C.; Lesage, A. A. J.; Lester, C. G.; Levchenko, M.; Levêque, J.; Levin, D.; Levinson, L. J.; Levy, M.; Lewis, D.; Leyton, M.; Li, B.; Li, C.; Li, H.; Li, L.; Li, L.; Li, Q.; Li, S.; Li, X.; Li, Y.; Liang, Z.; Liberti, B.; Liblong, A.; Lie, K.; Liebal, J.; Liebig, W.; Limosani, A.; Lin, S. C.; Lin, T. H.; Lindquist, B. E.; Lionti, A. E.; Lipeles, E.; Lipniacka, A.; Lisovyi, M.; Liss, T. M.; Lister, A.; Litke, A. M.; Liu, B.; Liu, H.; Liu, H.; Liu, J.; Liu, J. B.; Liu, K.; Liu, L.; Liu, M.; Liu, Y. L.; Liu, Y.; Livan, M.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lo, C. Y.; Lo Sterzo, F.; Lobodzinska, E. M.; Loch, P.; Loebinger, F. K.; Loew, K. M.; Loginov, A.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Long, B. A.; Long, J. D.; Long, R. E.; Longo, L.; Looper, K. A.; Lopez, J. A.; Lopez Mateos, D.; Lopez Paz, I.; Lopez Solis, A.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Lösel, P. J.; Lou, X.; Lounis, A.; Love, J.; Love, P. A.; Lu, H.; Lu, N.; Lu, Y. J.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Luedtke, C.; Luehring, F.; Lukas, W.; Luminari, L.; Lundberg, O.; Lund-Jensen, B.; Luzi, P. M.; Lynn, D.; Lysak, R.; Lytken, E.; Lyubushkin, V.; Ma, H.; Ma, L. L.; Ma, Y.; Maccarrone, G.; Macchiolo, A.; MacDonald, C. M.; Maček, B.; Machado Miguens, J.; Madaffari, D.; Madar, R.; Maddocks, H. J.; Mader, W. F.; Madsen, A.; Maeda, J.; Maeland, S.; Maeno, T.; Maevskiy, A.; Magradze, E.; Mahlstedt, J.; Maiani, C.; Maidantchik, C.; Maier, A. A.; Maier, T.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Malaescu, B.; Malecki, Pa.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyukov, S.; Mamuzic, J.; Mancini, G.; Mandelli, L.; Mandić, I.; Maneira, J.; Manhaes de Andrade Filho, L.; Manjarres Ramos, J.; Mann, A.; Manousos, A.; Mansoulie, B.; Mansour, J. D.; Mantifel, R.; Mantoani, M.; Manzoni, S.; Mapelli, L.; Marceca, G.; March, L.; Marchiori, G.; Marcisovsky, M.; Marjanovic, M.; Marley, D. E.; Marroquim, F.; Marsden, S. P.; Marshall, Z.; Martensson, M. U. F.; Marti-Garcia, S.; Martin, C. B.; Martin, T. A.; Martin, V. J.; Martin Dit Latour, B.; Martinez, M.; Martinez Outschoorn, V. I.; Martin-Haugh, S.; Martoiu, V. S.; Martyniuk, A. C.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, L.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mättig, P.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Maznas, I.; Mazza, S. M.; Mc Fadden, N. C.; McGoldrick, G.; McKee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McClymont, L. I.; McDonald, E. F.; McFayden, J. A.; McHedlidze, G.; McMahon, S. J.; McNamara, P. C.; McPherson, R. A.; Meehan, S.; Megy, T. J.; Mehlhase, S.; Mehta, A.; Meideck, T.; Meier, K.; Meineck, C.; Meirose, B.; Melini, D.; Mellado Garcia, B. R.; Melo, M.; Meloni, F.; Menary, S. B.; Meng, L.; Meng, X. T.; Mengarelli, A.; Menke, S.; Meoni, E.; Mergelmeyer, S.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Meyer Zu Theenhausen, H.; Miano, F.; Middleton, R. P.; Miglioranzi, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milesi, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Minaenko, A. A.; Minami, Y.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Minegishi, Y.; Ming, Y.; Mir, L. M.; Mistry, K. P.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Miucci, A.; Miyagawa, P. S.; Mizukami, A.; Mjörnmark, J. U.; Mlynarikova, M.; Moa, T.; Mochizuki, K.; Mogg, P.; Mohapatra, S.; Molander, S.; Moles-Valls, R.; Monden, R.; Mondragon, M. C.; Mönig, K.; Monk, J.; Monnier, E.; Montalbano, A.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Morange, N.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Morgenstern, S.; Mori, D.; Mori, T.; Morii, M.; Morinaga, M.; Morisbak, V.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Morvaj, L.; Moschovakos, P.; Mosidze, M.; Moss, H. J.; Moss, J.; Motohashi, K.; Mount, R.; Mountricha, E.; Moyse, E. J. W.; Muanza, S.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, R. S. P.; Muenstermann, D.; Mullen, P.; Mullier, G. A.; Munoz Sanchez, F. J.; Murray, W. J.; Musheghyan, H.; Muškinja, M.; Myagkov, A. G.; Myska, M.; Nachman, B. P.; Nackenhorst, O.; Nagai, K.; Nagai, R.; Nagano, K.; Nagasaka, Y.; Nagata, K.; Nagel, M.; Nagy, E.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Naranjo Garcia, R. F.; Narayan, R.; Narrias Villar, D. I.; Naryshkin, I.; Naumann, T.; Navarro, G.; Nayyar, R.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Negri, A.; Negrini, M.; Nektarijevic, S.; Nellist, C.; Nelson, A.; Nelson, M. E.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neves, R. M.; Newman, P. R.; Ng, T. Y.; Nguyen Manh, T.; Nickerson, R. B.; Nicolaidou, R.; Nielsen, J.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolopoulos, K.; Nilsen, J. K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nishu, N.; Nisius, R.; Nobe, T.; Noguchi, Y.; Nomachi, M.; Nomidis, I.; Nomura, M. A.; Nooney, T.; Nordberg, M.; Norjoharuddeen, N.; Novgorodova, O.; Nowak, S.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nurse, E.; Nuti, F.; O'Neil, D. C.; O'Rourke, A. A.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermann, T.; Ocariz, J.; Ochi, A.; Ochoa, I.; Ochoa-Ricoux, J. P.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Oide, H.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Oleiro Seabra, L. F.; Olivares Pino, S. A.; Oliveira Damazio, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onogi, K.; Onyisi, P. U. E.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero Y Garzon, G.; Otono, H.; Ouchrif, M.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Owen, M.; Owen, R. E.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Pacheco Rodriguez, L.; Padilla Aranda, C.; Pagan Griso, S.; Paganini, M.; Paige, F.; Pais, P.; Palacino, G.; Palazzo, S.; Palestini, S.; Palka, M.; Pallin, D.; Panagiotopoulou, E. St.; Panagoulias, I.; Pandini, C. E.; Panduro Vazquez, J. G.; Pani, P.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, A. J.; Parker, M. A.; Parker, K. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pascuzzi, V. R.; Pasner, J. M.; Pasqualucci, E.; Passaggio, S.; Pastore, Fr.; Pataraia, S.; Pater, J. R.; Pauly, T.; Pearce, J.; Pearson, B.; Pedersen, L. E.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Penc, O.; Peng, C.; Peng, H.; Penwell, J.; Peralva, B. S.; Perego, M. M.; Perepelitsa, D. V.; Perini, L.; Pernegger, H.; Perrella, S.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petroff, P.; Petrolo, E.; Petrov, M.; Petrucci, F.; Pettersson, N. E.; Peyaud, A.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Pickering, M. A.; Piegaia, R.; Pilcher, J. E.; Pilkington, A. D.; Pin, A. W. J.; Pinamonti, M.; Pinfold, J. L.; Pirumov, H.; Pitt, M.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Pluth, D.; Podberezko, P.; Poettgen, R.; Poggioli, L.; Pohl, D.; Polesello, G.; Poley, A.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Ponomarenko, D.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Poppleton, A.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozo Astigarraga, M. E.; Pralavorio, P.; Pranko, A.; Prell, S.; Price, D.; Price, L. E.; Primavera, M.; Prince, S.; Proklova, N.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Puddu, D.; Puri, A.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Raddum, S.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Raine, J. A.; Rajagopalan, S.; Rangel-Smith, C.; Ratti, M. G.; Rauch, D. M.; Rauscher, F.; Rave, S.; Ravenscroft, T.; Ravinovich, I.; Rawling, J. H.; Raymond, M.; Read, A. L.; Readioff, N. P.; Reale, M.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reed, R. G.; Reeves, K.; Rehnisch, L.; Reichert, J.; Reiss, A.; Rembser, C.; Ren, H.; Rescigno, M.; Resconi, S.; Resseguie, E. D.; Rettie, S.; Reynolds, E.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Richter, S.; Richter-Was, E.; Ricken, O.; Ridel, M.; Rieck, P.; Riegel, C. J.; Rieger, J.; Rifki, O.; Rijssenbeek, M.; Rimoldi, A.; Rimoldi, M.; Rinaldi, L.; Ristić, B.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Rizzi, C.; Roberts, R. T.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Rodina, Y.; Rodriguez Perez, A.; Rodriguez Rodriguez, D.; Roe, S.; Rogan, C. S.; Røhne, O.; Roloff, J.; Romaniouk, A.; Romano, M.; Romano Saez, S. M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Rosati, S.; Rosbach, K.; Rose, P.; Rosien, N.-A.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, J. H. N.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Russell, H. L.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryu, S.; Ryzhov, A.; Rzehorz, G. F.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Saha, P.; Sahinsoy, M.; Saimpert, M.; Saito, M.; Saito, T.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salazar Loyola, J. E.; Salek, D.; Sales de Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sammel, D.; Sampsonidis, D.; Sánchez, J.; Sanchez Martinez, V.; Sanchez Pineda, A.; Sandaker, H.; Sandbach, R. L.; Sander, C. O.; Sandhoff, M.; Sandoval, C.; Sankey, D. P. C.; Sannino, M.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sasaki, O.; Sato, K.; Sauvan, E.; Savage, G.; Savard, P.; Savic, N.; Sawyer, C.; Sawyer, L.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schachtner, B. M.; Schaefer, D.; Schaefer, L.; Schaefer, R.; Schaeffer, J.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Schiavi, C.; Schier, S.; Schildgen, L. K.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt-Sommerfeld, K. R.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, S.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schopf, E.; Schott, M.; Schouwenberg, J. F. P.; Schovancova, J.; Schramm, S.; Schuh, N.; Schulte, A.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwarz, T. A.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Sciandra, A.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Seema, P.; Seidel, S. C.; Seiden, A.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shaikh, N. W.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Shen, Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shirabe, S.; Shiyakova, M.; Shlomi, J.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shope, D. R.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sickles, A. M.; Sidebo, P. E.; Sideras Haddad, E.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silverstein, S. B.; Simak, V.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simon, M.; Sinervo, P.; Sinev, N. B.; Sioli, M.; Siragusa, G.; Siral, I.; Sivoklokov, S. Yu.; Sjölin, J.; Skinner, M. B.; Skubic, P.; Slater, M.; Slavicek, T.; Slawinska, M.; Sliwa, K.; Slovak, R.; Smakhtin, V.; Smart, B. H.; Smiesko, J.; Smirnov, N.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, J. W.; Smith, M. N. K.; Smith, R. W.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snyder, I. M.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Sokhrannyi, G.; Solans Sanchez, C. A.; Solar, M.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Son, H.; Song, H. Y.; Sopczak, A.; Sorin, V.; Sosa, D.; Sotiropoulou, C. L.; Soualah, R.; Soukharev, A. M.; South, D.; Sowden, B. C.; Spagnolo, S.; Spalla, M.; Spangenberg, M.; Spanò, F.; Sperlich, D.; Spettel, F.; Spieker, T. M.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; St. Denis, R. D.; Stabile, A.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, G. H.; Stark, J.; Stark, S. H.; Staroba, P.; Starovoitov, P.; Stärz, S.; Staszewski, R.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Suchek, S.; Sugaya, Y.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Suruliz, K.; Suster, C. J. E.; Sutton, M. R.; Suzuki, S.; Svatos, M.; Swiatlowski, M.; Swift, S. P.; Sydorenko, A.; Sykora, I.; Sykora, T.; Ta, D.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tanaka, J.; Tanaka, M.; Tanaka, R.; Tanaka, S.; Tanioka, R.; Tannenwald, B. B.; Tapia Araya, S.; Tapprogge, S.; Tarem, S.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, A. C.; Taylor, G. N.; Taylor, P. T. E.; Taylor, W.; Teixeira-Dias, P.; Temple, D.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Tepel, F.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Tibbetts, M. J.; Ticse Torres, R. E.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tipton, P.; Tisserant, S.; Todome, K.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, B.; Tornambe, P.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Treado, C. J.; Trefzger, T.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Trofymov, A.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tsang, K. W.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tu, Y.; Tudorache, A.; Tudorache, V.; Tulbure, T. T.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turgeman, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Ucchielli, G.; Ueda, I.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usui, J.; Vacavant, L.; Vacek, V.; Vachon, B.; Valderanis, C.; Valdes Santurio, E.; Valencic, N.; Valentinetti, S.; Valero, A.; Valéry, L.; Valkar, S.; Vallier, A.; Valls Ferrer, J. A.; van den Wollenberg, W.; van der Graaf, H.; van Eldik, N.; van Gemmeren, P.; van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varni, C.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vasquez, G. A.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veeraraghavan, V.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vetterli, M. C.; Viaux Maira, N.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vishwakarma, A.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vlasak, M.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, Q.; Wang, R.; Wang, S. M.; Wang, T.; Wang, W.; Wang, W.; Wang, Z.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, A. F.; Webb, S.; Weber, M. S.; Weber, S. W.; Weber, S. A.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M. D.; Werner, P.; Wessels, M.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A.; White, M. J.; White, R.; Whiteson, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilk, F.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winston, O. J.; Winter, B. T.; Wittgen, M.; Wobisch, M.; Wolf, T. M. H.; Wolff, R.; Wolter, M. W.; Wolters, H.; Worm, S. D.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xi, Z.; Xia, L.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yigitbasi, E.; Yildirim, E.; Yorita, K.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J.; Yuan, L.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zacharis, G.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, L.; Zhang, M.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Y.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, M.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zou, R.; Zur Nedden, M.; Zwalinski, L.


    Light-by-light scattering (γγ --> γγ) is a quantum-mechanical process that is forbidden in the classical theory of electrodynamics. This reaction is accessible at the Large Hadron Collider thanks to the large electromagnetic field strengths generated by ultra-relativistic colliding lead ions. Using 480 μb-1 of lead-lead collision data recorded at a centre-of-mass energy per nucleon pair of 5.02 TeV by the ATLAS detector, here we report evidence for light-by-light scattering. A total of 13 candidate events were observed with an expected background of 2.6 +/- 0.7 events. After background subtraction and analysis corrections, the fiducial cross-section of the process Pb + Pb (γγ) --> Pb(*) + Pb(*)γγ, for photon transverse energy ET > 3 GeV, photon absolute pseudorapidity |η| mass greater than 6 GeV, diphoton transverse momentum lower than 2 GeV and diphoton acoplanarity below 0.01, is measured to be 70 +/- 24 (stat.) +/- 17 (syst.) nb, which is in agreement with the standard model predictions.

  16. Backscattering of linearly polarized light from turbid tissue-like scattering medium with rough surface (United States)

    Doronin, Alexander; Tchvialeva, Lioudmila; Markhvida, Igor; Lee, Tim K.; Meglinski, Igor


    In the framework of further development of a unified computational tool for the needs of biomedical optics, we introduce an electric field Monte Carlo (MC) model for simulation of backscattering of coherent linearly polarized light from a turbid tissue-like scattering medium with a rough surface. We consider the laser speckle patterns formation and the role of surface roughness in the depolarization of linearly polarized light backscattered from the medium. The mutual phase shifts due to the photons' pathlength difference within the medium and due to reflection/refraction on the rough surface of the medium are taken into account. The validation of the model includes the creation of the phantoms of various roughness and optical properties, measurements of co- and cross-polarized components of the backscattered/reflected light, its analysis and extensive computer modeling accelerated by parallel computing on the NVIDIA graphics processing units using compute unified device architecture (CUDA). The analysis of the spatial intensity distribution is based on second-order statistics that shows a strong correlation with the surface roughness, both with the results of modeling and experiment. The results of modeling show a good agreement with the results of experimental measurements on phantoms mimicking human skin. The developed MC approach can be used for the direct simulation of light scattered by the turbid scattering medium with various roughness of the surface.

  17. Characterization of strongly scattering nanoporous materials as miniaturized multipass cell for tunable diode laser absorption spectroscopy (United States)

    Venturini, F.; Schönherr, V.; Rey, J. M.; Adolfsson, E.


    Through the confinement of gas in nanoporous materials, it is possible to significantly increase the path length for light-gas interaction. This enables the observation of much stronger absorption features for the confined gas molecules. In this work, we systematically characterized a variety of disordered strongly scattering ZrO_2 and Al_2O_3 nanoporous ceramic materials to exploit the potential of gas in scattering media absorption spectroscopy. As a result, we identified a material with an unprecedented performance in terms of optical path length enhancement. In ZrO_2 with thicknesses above 6 mm, the path enhancement exceeds 1000. The results obtained with near-infrared absorption spectroscopy on oxygen were validated by time-of-flight measurements at 700 nm, thus demonstrating their robustness. Finally, we report quantitative oxygen concentration measurement using nanoporous materials as miniaturized random-scattering multipass cell with an extremely simple and low-cost setup.

  18. Stochastic methods for light propagation and recurrent scattering in saturated and nonsaturated atomic ensembles (United States)

    Lee, Mark D.; Jenkins, Stewart D.; Ruostekoski, Janne


    We derive equations for the strongly coupled system of light and dense atomic ensembles. The formalism includes an arbitrary internal-level structure for the atoms and is not restricted to weak excitation of atoms by light. In the low-light-intensity limit for atoms with a single electronic ground state, the full quantum field-theoretical representation of the model can be solved exactly by means of classical stochastic electrodynamics simulations for stationary atoms that represent cold atomic ensembles. Simulations for the optical response of atoms in a quantum degenerate regime require one to synthesize a stochastic ensemble of atomic positions that generates the corresponding quantum statistical position correlations between the atoms. In the case of multiple ground levels or at light intensities where saturation becomes important, the classical simulations require approximations that neglect quantum fluctuations between the levels. We show how the model is extended to incorporate corrections due to quantum fluctuations that result from virtual scattering processes. In the low-light-intensity limit, we illustrate the simulations in a system of atoms in a Mott-insulator state in a two-dimensional optical lattice, where recurrent scattering of light induces strong interatomic correlations. These correlations result in collective many-atom subradiant and superradiant states and a strong dependence of the response on the spatial confinement within the lattice sites.

  19. Convergent close-coupling approach to light and heavy projectile scattering on atomic and molecular hydrogen (United States)

    Bray, I.; Abdurakhmanov, I. B.; Bailey, J. J.; Bray, A. W.; Fursa, D. V.; Kadyrov, A. S.; Rawlins, C. M.; Savage, J. S.; Stelbovics, A. T.; Zammit, M. C.


    The atomic hydrogen target has played a pivotal role in the development of quantum collision theory. The key complexities of computationally managing the countably infinite discrete states and the uncountably infinite continuum were solved by using atomic hydrogen as the prototype atomic target. In the case of positron or proton scattering the extra complexity of charge exchange was also solved using the atomic hydrogen target. Most recently, molecular hydrogen has been used successfully as a prototype molecule for developing the corresponding scattering theory. We concentrate on the convergent close-coupling computational approach to light projectiles, such as electrons and positrons, and heavy projectiles, such as protons and antiprotons, scattering on atomic and molecular hydrogen.

  20. Plane-wave coupling formalism for T -matrix simulations of light scattering by nonspherical particles (United States)

    Theobald, Dominik; Egel, Amos; Gomard, Guillaume; Lemmer, Uli


    The computation of light scattering by the superposition T -matrix scheme has been restricted thus far to systems made of particles that are either sparsely distributed or of near-spherical shape. In this work, we extend the range of applicability of the T -matrix method by accounting for the coupling of scattered fields between highly nonspherical particles in close vicinity. This is achieved using an alternative formulation of the translation operator for spherical vector wave functions, based on a plane-wave expansion of the particle's scattered electromagnetic field. The accuracy and versatility of the present approach is demonstrated by simulating arbitrarily oriented and densely packed spheroids, for both dielectric and metallic particles.

  1. Light scattering and photon statistics of quantum emitters coupled to metallic nanoparticles

    Directory of Open Access Journals (Sweden)

    O. Di Stefano


    Full Text Available We study theoretically the quantum optical properties of hybrid artificial molecules composed of an individual quantum emitter and a metallic nanoparticle. The coupling between the two systems can give rise to a Fano interference effect which strongly influences the quantum statistical properties of the scattered photons: a small frequency shift of the incident light field may cause changes in the intensity correlation function of the scattered field of orders of magnitude. The system opens a good perspective for applications in active metamaterials and ultracompact single-photon devices. We also demonstrate with accurate scattering calculations that a system constituted by a single quantum emitter (a semiconductor quantum dot placed in the gap between two metallic nanoparticles can display the vacuum Rabi splitting.

  2. Influence of water uptake on the aerosol particle light scattering coefficients of the Central European aerosol

    Directory of Open Access Journals (Sweden)

    Paul Zieger


    Full Text Available The influence of aerosol water uptake on the aerosol particle light scattering was examined at the regional continental research site Melpitz, Germany. The scattering enhancement factor f(RH, defined as the aerosol particle scattering coefficient at a certain relative humidity (RH divided by its dry value, was measured using a humidified nephelometer. The chemical composition and other microphysical properties were measured in parallel. f(RH showed a strong variation, e.g. with values between 1.2 and 3.6 at RH=85% and λ=550 nm. The chemical composition was found to be the main factor determining the magnitude of f(RH, since the magnitude of f(RH clearly correlated with the inorganic mass fraction measured by an aerosol mass spectrometer (AMS. Hysteresis within the recorded humidograms was observed and explained by long-range transported sea salt. A closure study using Mie theory showed the consistency of the measured parameters.

  3. Light scattering by epitaxial VO{sub 2} films near the metal-insulator transition point

    Energy Technology Data Exchange (ETDEWEB)

    Lysenko, Sergiy, E-mail:; Fernández, Felix; Rúa, Armando; Figueroa, Jose; Vargas, Kevin; Cordero, Joseph [Department of Physics, University of Puerto Rico, Mayaguez, Puerto Rico 00681 (United States); Aparicio, Joaquin [Department of Physics, University of Puerto Rico-Ponce, Ponce, Puerto Rico 00732 (United States); Sepúlveda, Nelson [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)


    Experimental observation of metal-insulator transition in epitaxial films of vanadium dioxide is reported. Hemispherical angle-resolved light scattering technique is applied for statistical analysis of the phase transition processes on mesoscale. It is shown that the thermal hysteresis strongly depends on spatial frequency of surface irregularities. The transformation of scattering indicatrix depends on sample morphology and is principally different for the thin films with higher internal elastic strain and for the thicker films where this strain is suppressed by introduction of misfit dislocations. The evolution of scattering indicatrix, fractal dimension, surface power spectral density, and surface autocorrelation function demonstrates distinctive behavior which elucidates the influence of structural defects and strain on thermal hysteresis, twinning of microcrystallites, and domain formation during the phase transition.

  4. Size distribution and radial density profile of synaptic vesicles by SAXS and light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Castorph, Simon; Salditt, Tim [Institute for X-ray Physics, Goettingen (Germany); Holt, Matthew; Jahn, Reinhard [Max Plank Institute for Biophysical Chemistry, Goettingen (Germany); Sztucki, Michael [European Synchrotron Radiation Facility, Grenoble (France)


    Synaptic vesicles are small membraneous organelles within the nerve terminal, encapsulating neurotransmitters by a lipid bilayer. The transport of the neurotransmitter, the fusion at the plasma membrane, and the release of the stored neurotransmitters into the synaptic cleft are since long know as essential step in nerve conduction of the chemical synapse. A detailed structural view of these molecular mechanisms is still lacking, not withstanding the enormous progress in the field during recent years. From measurements and quantitative fitting of small angle X-ray scattering curves and dynamic light scattering the averaged structural properties of synaptic vesicles can be determined. We present SAXS measurements and fits revealing the width of the size distribution function and details of the radial scattering length profile of synaptic vesicles from rat brain. Representative values for the inner and outer radius and the size polydispersity as well as the density and width of the outer protein layer are obtained.

  5. Scattering matrix analysis for evaluating the photocurrent in hydrogenated-amorphous-silicon-based thin film solar cells. (United States)

    Shin, Myunghun; Lee, Seong Hyun; Lim, Jung Wook; Yun, Sun Jin


    A scattering matrix (S-matrix) analysis method was developed for evaluating hydrogenated amorphous silicon (a-Si:H)-based thin film solar cells. In this approach, light wave vectors A and B represent the incoming and outgoing behaviors of the incident solar light, respectively, in terms of coherent wave and incoherent intensity components. The S-matrix determines the relation between A and B according to optical effects such as reflection and transmission, as described by the Fresnel equations, scattering at the boundary surfaces, or scattering within the propagation medium, as described by the Beer-Lambert law and the change in the phase of the propagating light wave. This matrix can be used to evaluate the behavior of angle-incident coherent and incoherent light simultaneously, and takes into account not only the light scattering process at material boundaries (haze effects) but also nonlinear optical processes within the material. The optical parameters in the S-matrix were determined by modeling both a 2%-gallium-doped zinc oxide transparent conducting oxide and germanium-compounded a-Si:H (a-SiGe:H). Using the S-matrix equations, the photocurrent for an a-Si:H/a-SiGe:H tandem cell and the optical loss in semitransparent a-Si:H solar cells for use in building-integrated photovoltaic applications were analyzed. The developed S-matrix method can also be used as a general analysis tool for various thin film solar cells.

  6. Computational modeling and experimental characterization of bacterial microcolonies for rapid detection using light scattering (United States)

    Bai, Nan

    A label-free and nondestructive optical elastic forward light scattering method has been extended for the analysis of microcolonies for food-borne bacteria detection and identification. To understand the forward light scattering phenomenon, a model based on the scalar diffraction theory has been employed: a bacterial colony is considered as a biological spatial light modulator with amplitude and phase modulation to the incoming light, which continues to propagate to the far-field to form a distinct scattering 'fingerprint'. Numerical implementation via angular spectrum method (ASM) and Fresnel approximation have been carried out through Fast Fourier Transform (FFT) to simulate this optical model. Sampling criteria to achieve unbiased and un-aliased simulation results have been derived and the effects of violating these conditions have been studied. Diffraction patterns predicted by these two methods (ASM and Fresnel) have been compared to show their applicability to different simulation settings. Through the simulation work, the correlation between the colony morphology and its forward scattering pattern has been established to link the number of diffraction rings and the half cone angle with the diameter and the central height of the Gaussian-shaped colonies. In order to experimentally prove the correlation, a colony morphology analyzer has been built and used to characterize the morphology of different bacteria genera and investigate their growth dynamics. The experimental measurements have demonstrated the possibility of differentiating bacteria Salmonella, Listeria, Escherichia in their early growth stage (100˜500 µm) based on their phenotypic characteristics. This conclusion has important implications in microcolony detection, as most bacteria of our interest need much less incubation time (8˜12 hours) to grow into this size range. The original forward light scatterometer has been updated to capture scattering patterns from microcolonies. Experiments have

  7. A comparative study of processing simulated and experimental data in elastic laser light scattering. (United States)

    Popovici, M A; Mincu, N; Popovici, A


    The intensity of the laser light scattered by a suspension of biological particles undergoing Brownian motion contains information about their size distribution function and optical properties. We used several methods (implemented in MathCAD programs), including a new one, to invert the Fredholm integral equation of the first kind, which represents the angular dependence of the elastic scattering of light. The algorithms were first tested on different sets of simulated data. Experimental data were obtained using biological samples and an experimental arrangement which are briefly described. We study the stability of the inversion procedures relative to the noise levels, and compute the first two moments of the retrieved size distribution function. A comparison of the results corresponding to simulated and experimental data is done, to select the best processing algorithm.

  8. Phonon anharmonicity in zirconium tungstate single crystal investigated by broadband light scattering (United States)

    Oishi, Eiichi; Fujii, Yasuhiro; Katayama, Daisuke; Koreeda, Akitoshi; Nagakubo, Akira; Ogi, Hirotsugu


    We measured light scattering in a single crystal of ZrW2O8 (ZWO) in the frequency range between 0.1 and 1100 cm-1 and in the temperature range between 3.5 and 300 K. From the temperature dependence of the optical and acoustic phonon frequencies, we found that low-frequency phonon modes below 100 cm-1 have large relative temperature coefficients (total anharmonicity values). The longitudinal acoustic mode, whose Brillouin light scattering has not been reported thus far, was found to have the largest negative total anharmonicity in a wide temperature range, indicating the possibility that the acoustic modes, as well as the low-frequency optical modes that are associated with the motions of WO4 and ZrO6 polyhedra, should contribute to the negative thermal expansion of ZWO.

  9. Simultaneous measurement of amyloid fibril formation by dynamic light scattering and fluorescence reveals complex aggregation kinetics.

    Directory of Open Access Journals (Sweden)

    Aaron M Streets

    Full Text Available An apparatus that combines dynamic light scattering and Thioflavin T fluorescence detection is used to simultaneously probe fibril formation in polyglutamine peptides, the aggregating subunit associated with Huntington's disease, in vitro. Huntington's disease is a neurodegenerative disorder in a class of human pathologies that includes Alzheimer's and Parkinson's disease. These pathologies are all related by the propensity of their associated protein or polypeptide to form insoluble, β-sheet rich, amyloid fibrils. Despite the wide range of amino acid sequence in the aggregation prone polypeptides associated with these diseases, the resulting amyloids display strikingly similar physical structure, an observation which suggests a physical basis for amyloid fibril formation. Thioflavin T fluorescence reports β-sheet fibril content while dynamic light scattering measures particle size distributions. The combined techniques allow elucidation of complex aggregation kinetics and are used to reveal multiple stages of amyloid fibril formation.

  10. Scattering of slow-light gap solitons with charges in a two-level medium

    Energy Technology Data Exchange (ETDEWEB)

    Leon, J; Anghel-Vasilescu, P; Allegra, N [Laboratoire de Physique Theorique et Astroparticules, Universite de Montpellier 2 (CNRS-IN2P3), F34095 Montpellier (France); Ginovart, F [Laboratoire FOTON, Universite de Rennes, ENSSAT (CNRS), F22305 Lannion (France)


    The Maxwell-Bloch system describes a quantum two-level medium interacting with a classical electromagnetic field by mediation of the population density. This population density variation is a purely quantum effect which is actually at the very origin of nonlinearity. The resulting nonlinear coupling possesses particularly interesting consequences at the resonance (when the frequency of the excitation is close to the transition frequency of the two-level medium) as e.g. slow-light gap solitons that result from the nonlinear instability of the evanescent wave at the boundary. As nonlinearity couples the different polarizations of the electromagnetic field, the slow-light gap soliton is shown to experience effective scattering with charges in the medium, allowing it for instance to be trapped or reflected. This scattering process is understood qualitatively as being governed by a nonlinear Schroedinger model in an external potential related to the charges (the electrostatic permanent background component of the field)

  11. Investigating acoustic-induced deformations in a foam using multiple light scattering. (United States)

    Erpelding, M; Guillermic, R M; Dollet, B; Saint-Jalmes, A; Crassous, J


    We have studied the effect of an external acoustic wave on bubble displacements inside an aqueous foam. The signature of the acoustic-induced bubble displacements is found using a multiple light scattering technique, and occurs as a modulation on the photon correlation curve. Measurements for various sound frequencies and amplitudes are compared to analytical predictions and numerical simulations. These comparisons finally allow us to elucidate the nontrivial acoustic displacement profile inside the foam; in particular, we find that the acoustic wave creates a localized shear in the vicinity of the solid walls holding the foam, as a consequence of inertial contributions. This study of how bubbles "dance" inside a foam as a response to sound turns out to provide new insights on foam acoustics and sound transmission into a foam, foam deformation at high frequencies, and analysis of light scattering data in samples undergoing nonhomogeneous deformations.

  12. Sizing aerosolized fractal nanoparticle aggregates through Bayesian analysis of wide-angle light scattering (WALS) data (United States)

    Huber, Franz J. T.; Will, Stefan; Daun, Kyle J.


    Inferring the size distribution of aerosolized fractal aggregates from the angular distribution of elastically scattered light is a mathematically ill-posed problem. This paper presents a procedure for analyzing Wide-Angle Light Scattering (WALS) data using Bayesian inference. The outcome is probability densities for the recovered size distribution and aggregate morphology parameters. This technique is applied to both synthetic data and experimental data collected on soot-laden aerosols, using a measurement equation derived from Rayleigh-Debye-Gans fractal aggregate (RDG-FA) theory. In the case of experimental data, the recovered aggregate size distribution parameters are generally consistent with TEM-derived values, but the accuracy is impaired by the well-known limited accuracy of RDG-FA theory. Finally, we show how this bias could potentially be avoided using the approximation error technique.

  13. Quantitative and Isolated Measurement of Far-Field Light Scattering by a Single Nanostructure (United States)

    Kim, Donghyeong; Jeong, Kwang-Yong; Kim, Jinhyung; Ee, Ho-Seok; Kang, Ju-Hyung; Park, Hong-Gyu; Seo, Min-Kyo


    Light scattering by nanostructures has facilitated research on various optical phenomena and applications by interfacing the near fields and free-propagating radiation. However, direct quantitative measurement of far-field scattering by a single nanostructure on the wavelength scale or less is highly challenging. Conventional back-focal-plane imaging covers only a limited solid angle determined by the numerical aperture of the objectives and suffers from optical aberration and distortion. Here, we present a quantitative measurement of the differential far-field scattering cross section of a single nanostructure over the full hemisphere. In goniometer-based far-field scanning with a high signal-to-noise ratio of approximately 27.4 dB, weak scattering signals are efficiently isolated and detected under total-internal-reflection illumination. Systematic measurements reveal that the total and differential scattering cross sections of a Au nanorod are determined by the plasmonic Fabry-Perot resonances and the phase-matching conditions to the free-propagating radiation, respectively. We believe that our angle-resolved far-field measurement scheme provides a way to investigate and evaluate the physical properties and performance of nano-optical materials and phenomena.

  14. Label-free, non-invasive light scattering sensor for rapid screening of Bacillus colonies. (United States)

    Singh, Atul K; Sun, Xiulan; Bai, Xingjian; Kim, Huisung; Abdalhaseib, Maha Usama; Bae, Euiwon; Bhunia, Arun K


    Bacillus species are widely distributed in nature and have great significance both as industrially beneficial microbes and as public health burdens. We employed a novel light-scattering sensor, BARDOT (bacterial rapid detection using optical scattering technology) for instant screening of colonies of Bacillus species on agar plates. A total of 265 Bacillus and non-Bacillus isolates from our collection were used to develop and verify scatter image libraries including isolates from food, environmental and clinical samples. All Bacillus species (n=118) were detected with a high positive predictive value, PPV (≥90%) while non-Bacillus spp. had very low PPV (Bacillus colonies on phenol red mannitol (PRM) generated the highest differential scatter patterns and were used in subsequent studies. Surface plot analysis of scatter patterns confirmed differences for Bacillus and non-Bacillus isolates. BARDOT successfully detected Bacillus from inoculated baby formula, cheese, and naturally contaminated bovine unpasteurized milk in 7-16h. Ten of 129 colonies (isolates) from seven milk samples were Bacillus and remainders were non-Bacillus spp. BARDOT results were confirmed by PCR and 16S rDNA sequencing. This study demonstrates that BARDOT could be used as a screening tool to identify relevant Bacillus colonies from a community prior to genome sequencing. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Scattering of Light in Defocusing Media upon Linear Substrate Analysis of Formal Solutions

    CERN Document Server

    Ochirbat, G


    An analysis of formal solutions to the system of Maxwell equations has been performed for a scattering problem of stationary TM light waves in defocusing matter on a linear substrate. Bruster waves have been observed. A nontrivial plane wave has been found for which relation between a refraction constant and an intensity-dependent dielectric constant has been found. An asymptotic plane TM wave has been obtained, and a procedure of its finding has been elaborated.

  16. Dynamic Light Scattering as a Probe af Nanosized Entities: Applications In Materials and Life Sciences (United States)

    Yannopoulos, S. N.

    The ability of dynamic light scattering (DLS) to probe dynamics in non-crystalline media and to provide by virtue of this rather accurate estimations of dimensions of nanosized entities is discussed in this contribution. Selected applications of DLS in materials science (supercooled liquids) and life sciences (use of DLS as a diagnostic tool for early cataract detection in the ocular lens) are briefly discussed.

  17. Probability density cloud as a geometrical tool to describe statistics of scattered light. (United States)

    Yaitskova, Natalia


    First-order statistics of scattered light is described using the representation of the probability density cloud, which visualizes a two-dimensional distribution for complex amplitude. The geometric parameters of the cloud are studied in detail and are connected to the statistical properties of phase. The moment-generating function for intensity is obtained in a closed form through these parameters. An example of exponentially modified normal distribution is provided to illustrate the functioning of this geometrical approach.

  18. Note on the use of localized beam models for light scattering theories in spherical coordinates. (United States)

    Wang, Jiajie; Gouesbet, Gèrard


    Localized beam models provide the most efficient and enlightening ways to evaluate beam shape coefficients of electromagnetic arbitrary shaped beams for use in light scattering theories. At the present time, they are valid in spherical and (circular and elliptical) cylindrical coordinates. A misuse of localized beam models in spherical coordinates recently appeared several times in the literature. We therefore present a warning to avoid the propagation of an incorrect use of localized beam models.

  19. Probability density cloud as a geometrical tool to describe statistics of scattered light (United States)

    Yaitskova, Natalia


    First-order statistics of scattered light is described using the representation of probability density cloud which visualizes a two-dimensional distribution for complex amplitude. The geometric parameters of the cloud are studied in detail and are connected to the statistical properties of phase. The moment-generating function for intensity is obtained in a closed form through these parameters. An example of exponentially modified normal distribution is provided to illustrate the functioning of this geometrical approach.

  20. Probing interactions and phase separations of proteins, colloids, and polymers with light scattering (United States)

    Parmar, Avanish Singh

    The broad objective of my research is to investigate the physical characteristics and interactions of macromolecules and nanoparticles, and the corresponding effects on their phase separation behavior using static and dynamic light scattering (SLS & DLS). Light scattering provides a non-invasive technique for monitoring the in-situ behavior of solutes in solution, including solute interactions, sizes, shapes, aggregation kinetics and even rheological properties of condensed phases. Initially, we investigated lysozyme solutions for the presence of preformed aggregates and clusters that can distort the kinetics of protein crystal nucleation studies in this important model system for protein crystallization. We found that both undersaturated and supersaturated lysozyme solutions contained population of large, pre-existing protein aggregate. Separating these clusters and analyzing their composition with gel chromatography indicated that these clusters represented pre-formed lysozyme aggregates, and not extrinsic protein contamination. We investigated the effect of chaotropic versus kosmotropic ions (water structure breakers vs. structure makers) on the hydration layer and hydrodynamic interactions of hen egg white lysozyme. Surprisingly, neither chaotropic nor kosmotropic ions affected the protein hydration layer. Salt-effects on direct and hydrodynamic protein interactions were determined as function of the solutions ionic strength and temperature. Using both static and dynamic light scattering, we investigated the nucleation of gold nanoparticles forming from supersaturated gold sols. We observed that two well separated populations of nuclei formed essentially simultaneously, with sizes of 3nm vs. several tens of nanometer, respectively. We explore the use of lysozyme as tracer particle for diffusion-base measurements of electrolyte solutions. We showed that the unusual stability of lysozyme and its enhanced colloidal stability enable viscosity measurement of salts

  1. Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations. (United States)

    Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin


    Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns.

  2. Noise from scattered light in Virgo's second science run data

    Energy Technology Data Exchange (ETDEWEB)

    Accadia, T; Belletoile, A [Laboratoire d' Annecy-le-Vieux de Physique des Particules (LAPP), IN2P3/CNRS, Universite de Savoie, F-74941 Annecy-le-Vieux (France); Acernese, F; Barone, F [INFN, Sezione di Napoli, Universita di Napoli ' Federico II' , Complesso Universitario di Monte S Angelo, I-80126 Napoli, Universita di Salerno, Fisciano, I-84084 Salerno (Italy); Antonucci, F; Astone, P [INFN, Sezione di Roma, Universita ' La Sapienza' , I-00185 Roma (Italy); Ballardin, G [European Gravitational Observatory (EGO), I-56021 Cascina (PI) (Italy); Barsuglia, M; Bouhou, B [AstroParticule et Cosmologie (APC), CNRS: UMR7164-IN2P3-Observatoire de Paris-Universite Denis Diderot-Paris 7 - CEA : DSM/IRFU (France); Bauer, Th S; Beker, M G; Blom, M [Nikhef, National Institute for Subatomic Physics, PO Box 41882, 1009 DB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Birindelli, S; Bondu, F [Universite Nice-Sophia-Antipolis, CNRS, Observatoire de la Cote d' Azur, F-06304 Nice, Institut de Physique de Rennes, CNRS, Universite de Rennes 1, 35042 Rennes (France); Bitossi, M; Bonelli, L; Boschi, V [INFN, Sezione di Pisa, Universita di Pisa, I-56127 Pisa, Universita di Siena, I-53100 Siena (Italy); Bizouard, M A [LAL, Universite Paris-Sud, IN2P3/CNRS, F-91898 Orsay, ESPCI, CNRS, F-75005 Paris (France); Bonnand, R [Laboratoire des Materiaux Avances (LMA), IN2P3/CNRS, F-69622 Villeurbanne, Lyon (France); Bosi, L, E-mail: irene.fiori@ego-gw.i [INFN, Sezione di Perugia, Universita di Perugia, I-06123 Perugia (Italy)


    Virgo is one of the large, ground-based interferometers aimed at detecting gravitational waves. One of the technical problems limiting its sensitivity is caused by light in the output beams which is backscattered by seismically excited surfaces and couples back into the main beam of the interferometer. The resulting noise was thoroughly studied, measured and mitigated before Virgo's second science run (VSR2). The residual noise during VSR2, which increases in periods with a large microseism activity, is accurately predicted by the theoretical model. The scattered light has been associated with transient events in the gravitational-wave signal of the interferometer.

  3. Long-Term Changes in Light Scattering in Chesapeake Bay Inferred from Secchi Depth, Light Attenuation, and Remote Sensing Measurements (United States)

    Gallegos, Charles L.; Werdell, P. Jeremy; McClain, Charles R.


    The relationship between the Secchi depth (Z(sub SD)) and the diffuse attenuation coefficient for photosynthetically active radiation (K(sub d)(PAR)), and in particular the product of the two, Z(sub SD) X K(sub d)(PAR), is governed primarily by the ratio of light scattering to absorption. We analyzed measurements of Z(sub SD) and K(sub d)(PAR) at main stem stations in Chesapeake Bay and found that the Z(sub SD) X K(sub d)(PAR) product has declined at rates varying from 0.020 to 0.033 /yr over the 17 to 25 years of measurement, implying that there has been a long -term increase in the scattering-to-absorption ratio. Remote sensing reflectance at the green wavelength most relevant to Z(sub SD) and K(sub d)(PAR) in these waters, R(sub rs)(555), did not exhibit an increasing trend over the 10 years of available measurements. To reconcile the observations we constructed a bio-optical model to calculate Z(sub SD), K(sub d)(PAR), Z(sub SD) X K(sub d)(PAR), and R(sub rs)(555) as a function of light attenuating substances and their mass-specific absorption and scattering coefficients. When simulations were based exclusively on changes in concentrations of light attenuating substances, a declining trend in Z(sub SD) E K(sub d) entailed an increasing trend in R(sub rs)(555), contrary to observations. To simulate both decreasing Z(sub SD) X K(sub d)(PAR) and stationary R(sub rs)(555), it was necessary to allow for a declining trend in the ratio of backscattering to total scattering. Within our simulations, this was accomplished by increasing the relative proportion of organic detritus with high mass-specific scattering and low backscattering ratio. An alternative explanation not explicitly modeled is an increasing tendency for the particulate matter to occur in large aggregates. Data to discriminate between these alternatives are not available.

  4. Focusing light through strongly scattering media by controlling binary amplitude optimization using genetic algorithm (United States)

    Liu, Zhipeng; Zhang, Bin; Feng, Qi; Chen, Zhaoyang; Lin, Chengyou; Ding, Yingchun


    Focusing light through strongly scattering media plays an important role in biomedical imaging and therapy. Here, we experimentally demonstrate light focusing through ZnO sample by controlling binary amplitude optimization using genetic algorithm. In the experiment, we use a Micro Electro-Mechanical System (MEMS)-based digital micromirror device (DMD) which is in amplitude-only modulation mode. The DMD consists of 1920×1080 square mirrors that can be independently controlled to reflect light to a desired position. We control only 160 thousand mirrors which are divided into 400 segments to modulate light focusing through the scattering media using advanced genetic algorithm. Light intensity at the target position is enhanced up to 50+/-5 times the average speckle intensity. The diameters of focusing spot can be changed ranging from 7 μm to 70 μm at arbitrary positions and multiple foci are obtained simultaneously. The spatial arrangement of multiple foci can be flexibly controlled. The advantage of DMDs lies in their switching speed up to 30 kHz, which has the potential to generate a focus in an ultra-short period of time. Our work provides a reference for the study of high speed wavefront shaping that is required in vivo tissues imaging.

  5. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue (United States)

    Lyndby, Niclas H.; Kühl, Michael; Wangpraseurt, Daniel


    Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.

  6. Characterizing Reversible Protein Association at Moderately High Concentration Via Composition-Gradient Static Light Scattering. (United States)

    Some, Daniel; Pollastrini, Joseph; Cao, Shawn


    Analysis of weakly self-associating macromolecules at concentrations beyond a few g/L is challenging on account of the confounding effect of thermodynamic nonideality on the association signal. When the reversible association comprises only 1 or 2 oligomeric species in equilibrium with the monomer, the nonideality may be accounted for in a relatively rigorous manner, but if more association states are involved, the analysis becomes quite complex. We show that under reasonable assumptions, the nonideality in a composition-gradient static light scattering measurement may be accounted for in a simple fashion. The correction is applied to determining the stoichiometry and binding affinity of a protein previously characterized via sedimentation equilibrium and dynamic light scattering. The results of the new analysis are remarkably self-consistent and in line with the expectations for the form of self-association predicted previously from analysis of the surface residuals, establishing composition-gradient multi-angle static light scattering with nonideality corrections as a critical technology for characterizing associative interactions in concentrated solutions. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  7. Simultaneous Analysis of Secondary Structure and Light Scattering from Circular Dichroism Titrations: Application to Vectofusin-1 (United States)

    Vermeer, Louic S.; Marquette, Arnaud; Schoup, Michel; Fenard, David; Galy, Anne; Bechinger, Burkhard


    Circular Dichroism data are often decomposed into their constituent spectra to quantify the secondary structure of peptides or proteins but the estimation of the secondary structure content fails when light scattering leads to spectral distortion. If peptide-induced liposome self-association occurs, subtracting control curves cannot correct for this. We show that if the cause of the light scattering is independent from the peptide structural changes, the CD spectra can be corrected using principal component analysis (PCA). The light scattering itself is analysed and found to be in good agreement with backscattering experiments. This method therefore allows to simultaneously follow structural changes related to peptide-liposome binding as well as peptide induced liposome self-association. We apply this method to study the structural changes and liposome binding of vectofusin-1, a transduction enhancing peptide used in lentivirus based gene therapy. Vectofusin-1 binds to POPC/POPS liposomes, causing a reversal of the negative liposome charge at high peptide concentrations. When the peptide charges exactly neutralise the lipid charges on both leaflets reversible liposome self-association occurs. These results are in good agreement with biological observations and provide further insight into the conditions required for efficent transduction enhancement. PMID:28004740

  8. Selenium-induced cataract--a correlation of dry mass content and light scattering. (United States)

    Palmquist, B M; Fagerholm, P; Landau, I


    Selenium-induced cataracts in young rats were used to compare light scattering and dry mass concentration along the lens axis. Selenium-treated rats and control rats were examined 1, 2, 4 and 6 days after subcutaneous injection of selenium or 0.9% NaCl. The development of nuclear cataract was followed with a Scheimpflug slit-lamp camera. Light-scattering was determined by densitometry of the negatives taken by the Scheimpflug camera. Dry mass concentration was determined by quantitative microradiography of the extracted lenses. Increasing light scatter was seen from day 2 to day 6. The dry mass concentration, however, was not changed until day 6. Two distinct zones were found surrounding the center of the nucleus, one with increased and one with decreased dry mass. The rapid changes in dry mass concentration were probably caused by shifts in water distribution within the lens. Similar zones of hydration have also been found in human senile nuclear cataract. Selenium-induced cataract in the rat is discussed in relation to human nuclear cataract.

  9. Collision-induced light scattering in a thin xenon layer between graphite slabs - MD study. (United States)

    Dawid, A; Górny, K; Wojcieszyk, D; Dendzik, Z; Gburski, Z


    The collision-induced light scattering many-body correlation functions and their spectra in thin xenon layer located between two parallel graphite slabs have been investigated by molecular dynamics computer simulations. The results have been obtained at three different distances (densities) between graphite slabs. Our simulations show the increased intensity of the interaction-induced light scattering spectra at low frequencies for xenon atoms in confined space, in comparison to the bulk xenon sample. Moreover, we show substantial dependence of the interaction-induced light scattering correlation functions of xenon on the distances between graphite slabs. The dynamics of xenon atoms in a confined space was also investigated by calculating the mean square displacement functions and related diffusion coefficients. The structural property of confined xenon layer was studied by calculating the density profile, perpendicular to the graphite slabs. Building of a fluid phase of xenon in the innermost part of the slot was observed. The nonlinear dependence of xenon diffusion coefficient on the separation distance between graphite slabs has been found. Copyright © 2014. Published by Elsevier B.V.

  10. Coherent self-heterodyne detection of spontaneously Brillouin-scattered light waves in a single-mode fiber (United States)

    Shimizu, Kaoru; Horiguchi, Tsuneo; Koyamada, Yahei; Kurashima, Toshio


    Time-domain reflectometry of spontaneous Brillouin scattering in a single-mode optical fiber is performed with a coherent self-heterodyne detection system containing a recently proposed external frequency translator and a single light-wave source. The light wave is divided into probe and reference light waves. The frequency of the probe light wave is upconverted by the translator by an amount approximately equal to the Brillouin frequency shift. The frequency-converted probe is launched into the fiber and spontaneously Brillouin scattered. As the frequency of the scattered probe is downconverted to near that of the reference light wave, coherent self-heterodyne detection of spontaneous Brillouin scattering becomes possible without having to use a fast-speed detector.

  11. New evaluation of thermal neutron scattering libraries for light and heavy water

    Directory of Open Access Journals (Sweden)

    Marquez Damian Jose Ignacio


    Full Text Available In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates, and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem. To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of

  12. New evaluation of thermal neutron scattering libraries for light and heavy water (United States)

    Marquez Damian, Jose Ignacio; Granada, Jose Rolando; Cantargi, Florencia; Roubtsov, Danila


    In order to improve the design and safety of thermal nuclear reactors and for verification of criticality safety conditions on systems with significant amount of fissile materials and water, it is necessary to perform high-precision neutron transport calculations and estimate uncertainties of the results. These calculations are based on neutron interaction data distributed in evaluated nuclear data libraries. To improve the evaluations of thermal scattering sub-libraries, we developed a set of thermal neutron scattering cross sections (scattering kernels) for hydrogen bound in light water, and deuterium and oxygen bound in heavy water, in the ENDF-6 format from room temperature up to the critical temperatures of molecular liquids. The new evaluations were generated and processable with NJOY99 and also with NJOY-2012 with minor modifications (updates), and with the new version of NJOY-2016. The new TSL libraries are based on molecular dynamics simulations with GROMACS and recent experimental data, and result in an improvement of the calculation of single neutron scattering quantities. In this work, we discuss the importance of taking into account self-diffusion in liquids to accurately describe the neutron scattering at low neutron energies (quasi-elastic peak problem). To improve modeling of heavy water, it is important to take into account temperature-dependent static structure factors and apply Sköld approximation to the coherent inelastic components of the scattering matrix. The usage of the new set of scattering matrices and cross-sections improves the calculation of thermal critical systems moderated and/or reflected with light/heavy water obtained from the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. For example, the use of the new thermal scattering library for heavy water, combined with the ROSFOND-2010 evaluation of the cross sections for deuterium, results in an improvement of the C/E ratio in 48 out of 65

  13. First results from light scattering enhancement factor over central Indian Himalayas during GVAX campaign. (United States)

    Dumka, U C; Kaskaoutis, D G; Sagar, Ram; Chen, Jianmin; Singh, Narendra; Tiwari, Suresh


    The present work examines the influence of relative humidity (RH), physical and optical aerosol properties on the light-scattering enhancement factor [f(RH=85%)] over central Indian Himalayas during the Ganges Valley Aerosol Experiment (GVAX). The aerosol hygroscopic properties were measured by means of DoE/ARM (US Department of Energy, Atmospheric Radiation Measurement) mobile facility focusing on periods with the regular instrumental operation (November-December 2011). The measured optical properties include aerosol light-scattering (σsp) and absorption (σap) coefficients and the intensive parameters i.e., single scattering albedo (SSA), scattering Ångström exponent (SAE), absorption Ångström exponent (AAE) and light scattering enhancement factor (f(RH)=σsp(RH, λ)/σsp(RHdry, λ)). The measurements were separated for sub-micron (affects the aerosol hygroscopicity since mean f(RH=85%) of 1.27±0.12 and 1.32±0.14 are found for D10μm and D1μm, respectively. These f(RH) values are relatively low suggesting the enhanced presence of soot and carbonaceous particles from biomass burning activities, which is verified via backward air-mass trajectories. Similarly, the light-scattering enhancement rates are ~0.20 and 0.17 for the D1μm and D10μm particles, respectively. However, a general tendency for increasing f(RH) and γ is shown for higher σsp and σap values indicating the presence of rather aged smoke plumes, coated with industrial aerosols over northern India, with mean SSA, SAE and AAE values of 0.92, 1.00 and 1.15 respectively. On the other hand, a moderate-to-small dependence of f(RH) and γ on SAE, AAE, and SSA was observed for both particle sizes. Furthermore, f(RH) exhibits an increasing tendency with the number of cloud condensation nuclei (NCCN) indicating larger particle hygroscopicity but without significant dependence on the activation ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Quantitative imaging of epithelial cell scattering identifies specific inhibitors of cell motility and cell-cell dissociation

    NARCIS (Netherlands)

    Loerke, D.; le Duc, Q.; Blonk, I.; Kerstens, A.; Spanjaard, E.; Machacek, M.; Danuser, G.; de Rooij, J.


    The scattering of cultured epithelial cells in response to hepatocyte growth factor (HGF) is a model system that recapitulates key features of metastatic cell behavior in vitro, including disruption of cell-cell adhesions and induction of cell migration. We have developed image analysis tools that

  15. Characterisation of scattering properties and evaluation of light transmittance of a scattering glazing unit for daylighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, G.; Sarotto, M. [IEN Galileo Ferraris, Torino (Italy); Maccari, A.; Zinzi, M. [ENEA-TML, CR Casaccia, Rome (Italy); Polato, P. [Stazione Sperimentale del Vetro, Murano-Venezia (Italy)


    Glazing with diffusing behaviour is used for daylighting applications whenever direct solar radiation should be avoided, as in office rooms, exhibition areas and so on. In this way, the discomfort phenomena due to glare effects and inadequate distribution of illuminance typical of conventional glazing can be avoided. At the moment, there are no standard procedures for the luminous characterisation of diffusing glazing. This implies a lack of information about scattering properties, as well as a wrong estimation of optical parameters as a result of measurements carried out using inaccurate procedures. Furthermore, the use of these data as inputs for simulation codes leads to a wrong estimation of the luminous environment and, in particular, of illuminance levels in a built up space. In this paper, a thorough optical investigation is carried out on a commercial laminated glass with a diffusing plastic sheet, to be used as a single or double-glazed unit. The characterisation concerns several experimental and evaluation sections: 1. Investigation with a goniophotometer, in order to obtain the normal-directional transmittance function of the sample; 2. Analysis of measurement uncertainties and their influence on the characterisation of the sample behaviour; 3. Determination of the light transmittance, by means of integrating sphere measurements, and following extrapolation procedures from the experimental results; 4. Determination of the scattering indices of the glazing unit, also considering the recent data reduction approaches developed within the IEA SH and C programme Task 21 and the RE-VIS Joule project frameworks; 5. Accurate daylighting simulations of an office room using Radiance. (au)

  16. Focusing light inside dynamic scattering media with millisecond digital optical phase conjugation (Conference Presentation) (United States)

    Liu, Yan; Ma, Cheng; Shen, Yuecheng; Wang, Lihong V.


    Optical phase conjugation based wavefront shaping techniques are being actively developed to focus light through or inside scattering media such as biological tissue, and they promise to revolutionize optical imaging, manipulation, and therapy. The speed of digital optical phase conjugation (DOPC) has been limited by the low speeds of cameras and spatial light modulators (SLMs), preventing DOPC from being applied to thick living tissue. Recently, a fast DOPC system was developed based on a single-shot wavefront measurement method, a field programmable gate array (FPGA) for data processing, and a digital micromirror device (DMD) for fast modulation. However, this system has the following limitations. First, the reported single-shot wavefront measurement method does not work when our goal is to focus light inside, instead of through, scattering media. Second, the DMD performed binary amplitude modulation, which resulted in a lower focusing contrast compared with that of phase modulations. Third, the optical fluence threshold causing DMDs to malfunction under pulsed laser illumination is lower than that of liquid crystal based SLMs, and the system alignment is significantly complicated by the oblique reflection angle of the DMD. Here, we developed a simple but high-speed DOPC system using a ferroelectric liquid crystal based SLM (512 × 512 pixels), and focused light through three diffusers within 4.7 ms. Using focused-ultrasound-guided DOPC along with a double exposure scheme, we focused light inside a scattering medium containing two diffusers within 7.7 ms, thus achieving the fastest digital time-reversed ultrasonically encoded (TRUE) optical focusing to date.

  17. Role of minerogenic particles in light scattering in lakes and a river in central New York. (United States)

    Peng, Feng; Effler, Steven W; O'Donnell, David; Perkins, Mary Gail; Weidemann, Alan


    The role of minerogenic particles in light scattering in several lakes and a river (total of ten sites) in central New York, which represent a robust range of scattering conditions, was evaluated based on an individual particle analysis technique of scanning electron microscopy interfaced with automated x-ray microanalysis and image analysis (SAX), in situ bulk measurements of particle scattering and backscattering coefficients (bp and bbp), and laboratory analyses of common indicators of scattering. SAX provided characterizations of the elemental x-ray composition, number concentration, particle size distribution (PSD), shape, and projected area concentration of minerogenic particles (PAVm) of sizes>0.4 microm. Mie theory was applied to calculate the minerogenic components of bp (bm) and bbp (bb,m) with SAX data. Differences in PAVm, associated primarily with clay minerals and CaCO3, were responsible for most of the measured differences in both bp and bbp across the study sites. Contributions of the specified minerogenic particle classes to bm were found to correspond approximately to their contributions to PAVm. The estimates of bm represented substantial fractions of bp, whereas those of bb,m were the dominant component of bbp. The representativeness of the estimates of bm and bb,m was supported by their consistency with the bulk measurements. Greater uncertainty prevails for the bb,m estimates than those for bm, associated primarily with reported deviations in particle shapes from sphericity. The PSDs were well represented by the "B" component of the two-component model or a three parameter generalized gamma distribution [Deep-Sea Res. Part I 40, 1459 (1993)]. The widely applied Junge (hyperbolic) function performed poorly in representing the PSDs and the size dependency of light scattering in these systems, by overrepresenting the concentrations of submicrometer particles especially. Submicrometer particles were not important contributors to bm or bb,m.

  18. Dual wavelength multiple-angle light scattering system for cryptosporidium detection (United States)

    Buaprathoom, S.; Pedley, S.; Sweeney, S. J.


    A simple, dual wavelength, multiple-angle, light scattering system has been developed for detecting cryptosporidium suspended in water. Cryptosporidium is a coccidial protozoan parasite causing cryptosporidiosis; a diarrheal disease of varying severity. The parasite is transmitted by ingestion of contaminated water, particularly drinking-water, but also accidental ingestion of bathing-water, including swimming pools. It is therefore important to be able to detect these parasites quickly, so that remedial action can be taken to reduce the risk of infection. The proposed system combines multiple-angle scattering detection of a single and two wavelengths, to collect relative wavelength angle-resolved scattering phase functions from tested suspension, and multivariate data analysis techniques to obtain characterizing information of samples under investigation. The system was designed to be simple, portable and inexpensive. It employs two diode lasers (violet InGaN-based and red AlGaInP-based) as light sources and silicon photodiodes as detectors and optical components, all of which are readily available. The measured scattering patterns using the dual wavelength system showed that the relative wavelength angle-resolved scattering pattern of cryptosporidium oocysts was significantly different from other particles (e.g. polystyrene latex sphere, E.coli). The single wavelength set up was applied for cryptosporidium oocysts'size and relative refractive index measurement and differential measurement of the concentration of cryptosporidium oocysts suspended in water and mixed polystyrene latex sphere suspension. The measurement results showed good agreement with the control reference values. These results indicate that the proposed method could potentially be applied to online detection in a water quality control system.

  19. Study of the relative humidity dependence of aerosol light-scattering in southern Spain

    Directory of Open Access Journals (Sweden)

    Gloria Titos


    Full Text Available This investigation focuses on the characterisation of the aerosol particle hygroscopicity. Aerosol particle optical properties were measured at Granada, Spain, during winter and spring seasons in 2013. Measured optical properties included particle light-absorption coefficient (σap and particle light-scattering coefficient (σsp at dry conditions and at relative humidity (RH of 85±10%. The scattering enhancement factor, f(RH=85%, had a mean value of 1.5±0.2 and 1.6±0.3 for winter and spring campaigns, respectively. Cases of high scattering enhancement were more frequent during the spring campaign with 27% of the f(RH=85% values above 1.8, while during the winter campaign only 8% of the data were above 1.8. A Saharan dust event (SDE, which occurred during the spring campaign, was characterised by a predominance of large particles with low hygroscopicity. For the day when the SDE was more intense, a mean daily value of f(RH=85%=1.3±0.2 was calculated. f(RH=85% diurnal cycle showed two minima during the morning and afternoon traffic rush hours due to the increase in non-hygroscopic particles such as black carbon and road dust. This was confirmed by small values of the single-scattering albedo and the scattering Ångstrom exponent. A significant correlation between f(RH=85% and the fraction of particulate organic matter and sulphate was obtained. Finally, the impact of ambient RH in the aerosol radiative forcing was found to be very small due to the low ambient RH. For high RH values, the hygroscopic effect should be taken into account since the aerosol forcing efficiency changed from −13 W/m2 at dry conditions to −17 W/m2 at RH=85%.

  20. Acid Treatment of Titania Pastes to Create Scattering Layers in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Trystan Watson


    Full Text Available In dye-sensitized solar cells (DSC scattering layers are used to increase the path length of light incident on the TiO2 film. This is typically achieved by the deposition of an additional TiO2 layer on top of an existing transparent film and designed to trap light. In this work we show that a simple acid pretreatment can lead to the formation of a scattering “skin” on the surface of a single TiO2 film performing a similar function to a scattering layer without any additional depositions. This is important in increasing manufacturing throughput for DSCs as further TiO2 depositions require additional materials and heat treatment. The pretreatment leads to self-assembly of a scattering layer of TiO2 which covers the surface on short-term immersion (<30 min and penetrates the bulk layer upon longer immersion. The method has been shown to increase the efficiency of the device by 20%.

  1. Holographic Imaging and Iterative Phase Optimization Methods for Focusing and Transmitting Light in Scattering Media (United States)

    Purcell, Michael James

    Existing methods for focusing and imaging through strongly scattering materials are often limited by speed, the need for invasive feedback, and the shallow depth of penetration of photons into the material. These limitations have motivated the present research into the development of a new iterative phase optimization method for improving transmission of light through a sample of strongly scattering material. A new method, based on the detection of back-scattered light combined with active (phase-only) wavefront control was found to be partially successful, decreasing the power of backscattered incident light at 488 nm wavelength by approximately 35% in a 626 mum thick sample of Yttria (Y2O3) nanopowder (mean particle size 26 nm) in clear epoxy with transport mean free path length ˜116 mum. However, the observed transmitted power did not show simultaneous improvement. The conclusion was reached that scattering to the sides of the sample and polarization scrambling were responsible for the lack of improved transmission with this method. Some ideas for improvement are discussed in the thesis. This research subsequently led to the development of a lensless holographic imaging method based on a rotating diffuser for statistical averaging of the optical signal for overcoming speckle caused by reflection from a rough surface. This method made it possible to reduce background variations of intensity due to speckle and improve images reflected from rough, immobile surfaces with no direct path for photons between the object and camera. Improvements in the images obtained with this technique were evaluated quantitatively by comparing SSIM indices and were found to offer practical advances for transmissive and reflective geometries alike.

  2. Matter from light-light scattering via Breit-Wheeler events produced by two interacting Compton sources

    Directory of Open Access Journals (Sweden)

    Illya Drebot


    Full Text Available We present the dimensioning of a photon-photon collider based on Compton gamma sources for the observation of Breit-Wheeler pair production and QED γγ events. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two gamma ray beams through Compton back scattering with two J-class lasers. Tuning the system energy above the Breit-Wheeler cross section threshold, a flux of electron-positron pairs is generated out of light-light interaction. The process is analyzed by start-to-end simulations. Realistic numbers of the secondary particle yield, referring to existing state-of-the-art set-ups and a discussion of the feasibility of the experiment taking into account the background signal are presented.

  3. Quantification of Doppler broadening in path length resolved diffusive light scattering using phase modulated low-coherence interferometry (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton G.; Steenbergen, Wiendelt


    We describe path length resolved Doppler measurements of the multiply scattered light in turbid media using phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. A Doppler broadened phase modulation interference peak observed at the modulation frequency shows an increase in the average Doppler shift with optical path length. The path length dependent Doppler broadening of scattered light due to the detection of multiple scattered light is measured from the Lorentzian linewidth and the results are compared with the predictions of Diffusive Wave Spectroscopy. For particles with small scattering anisotropy, the diffusion approximation shows good agreement with our experimental results. For anisotropic scatterers, the experimental results show deviations from the Diffusion theory. The optical path lengths are determined experimentally from the Zero order moment of the phase modulation peak around the modulation frequency and the results are validated with the Monte Carlo technique.

  4. In vivo optical path lengths and path length resolved doppler shifts of multiply scattered light. (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G; Steenbergen, Wiendelt


    % and that measured on the dorsal and palmar sides of the forearm are 32% and 17%, respectively. The path length distributions depend on the skin site that is being probed and the intra-individual inter-site variability is higher than the inter-individual within-site variability measured on comparable sites between different individuals. In this study, we demonstrated, for the first time to our knowledge, that in vivo path length resolved perfusion measurements are feasible. Optical path length distributions of multiply scattered light, spanning a range of 0-6 mm, and their response to external stimuli such as occlusion and capsicum cream provocation have been measured. This method will enable better interpretation of inter- and intra-individual inter-site variations in the LDF readings that are introduced by the variance in tissue optical properties. The inter- and intra-individual inter-site variations measured with our setup results indicate that that these variations should be taken into account while comparing the perfusion readings from comparable sites between individuals and from different sites of the same individual. Furthermore, the observed inter- and intra-individual inter-site variations in path length resolved Doppler measurements indicate the inherent limitation of conventional LDPM that restrict its clinical usefulness, due to its dependence on the unknown photon path length. Consequently, this method will enable to correctly interpret or counter-act the inter- and intra-individual inter-site variations in the LDF readings introduced by the variance in tissue optical properties. This approach also enables to discriminate between the Doppler-shifted photons resulting from interaction with the moving red blood cells and the non-shifted light scattered only by the surrounding static tissue matrices. © 2010 Wiley-Liss, Inc.

  5. Uncertainty of scattered light roughness measurements based on speckle correlation methods (United States)

    Patzelt, Stefan; Stöbener, Dirk; Ströbel, Gerald; Fischer, Andreas


    Surface micro topography measurement (e.g., form, waviness, roughness) is a precondition to assess the surface quality of technical components with regard to their applications. Well defined, standardized measuring devices measure and specify geometrical surface textures only under laboratory conditions. Laser speckle-based roughness measurement is a parametric optical scattered light measuring technique that overcomes this confinement. Field of view dimensions of some square millimeters and measuring frequencies in the kHz domain enable in-process roughness characterization of even moving part surfaces. However, camera exposure times of microseconds or less and a high detector pixel density mean less light energy per pixel due to the limited laser power. This affects the achievable measurement uncertainty according to the Heisenberg uncertainty principle. The influence of fundamental, inevitable noise sources such as the laser shot noise and the detector noise is not quantified yet. Therefore, the uncertainty for speckle roughness measurements is analytically estimated. The result confirms the expected inverse proportionality of the measurement uncertainty to the square root of the illuminating light power and the direct proportionality to the detector readout noise, quantization noise and dark current noise, respectively. For the first time it is possible to quantify the achievable measurement uncertainty u(Sa) < 1 nm for the scattered light measuring system. The low uncertainty offers ideal preconditions for in-process roughness measurements in an industrial environment with an aspired resolution of 1 nm.

  6. A portable optical waveguide resonance light-scattering scanner for microarray detection. (United States)

    Xing, Xuefeng; Liu, Wanyao; Li, Tao; Xing, Shu; Fu, Xueqi; Wu, Dongyang; Liu, Dianjun; Wang, Zhenxin


    In the present work, a portable and low-cost planar waveguide based resonance light scattering (RLS) scanner (termed as: PW-RLS scanner) has been developed for microarray detection. The PW-RLS scanner employs a 2 × 4 white light emitting diode array (WLEDA) as the excitation light source, a folded optical path with a complementary metal oxide semiconductor (CMOS) as the signal/image acquisition device and stepper motors with gear drives as the mechanical drive system. The biological binding/recognizing events on the microarray can be detected with an evanescent waveguide-directed illumination and light-scattering label (e.g., nanoparticles) while the microarray slide acts as an evanescent waveguide substrate. The performance of the as-developed PW-RLS scanner has been evaluated by analyzing type 2 diabetes mellitus (T2DM) risk genes. Highly selective and sensitive (less than 1% allele frequency at the attomole-level) T2DM risk gene detection is achieved using single-stranded DNA functionalized gold nanoparticles (ssDNA-GNPs) as detection probes. Additionally, the successful simultaneous analysis of 15 T2DM patient genotypes suggests that the device has great potential for the realization of a personalized diagnostic test for a given disease or patient follow-up.

  7. Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST). (United States)

    Jacobson, C M; Borchardt, M T; Den Hartog, D J; Falkowski, A F; Morton, L A; Thomas, M A


    The Thomson scattering diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser light. Stray light saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via Rayleigh scattering calibration. Furthermore, stray light contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray light levels during a vacuum vessel vent are used to identify stray light sources and strategies for reduction of stray light levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray light levels. Modeling produces qualitatively similar stray light distributions to MST measurements, and quantifies the mitigation effects of stray light mitigation strategies prior to implementation.

  8. Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST)

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, C. M., E-mail:; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Morton, L. A.; Thomas, M. A. [Department of Physics, University of Wisconsin–Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)


    The Thomson scattering diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser light. Stray light saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via Rayleigh scattering calibration. Furthermore, stray light contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray light levels during a vacuum vessel vent are used to identify stray light sources and strategies for reduction of stray light levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray light levels. Modeling produces qualitatively similar stray light distributions to MST measurements, and quantifies the mitigation effects of stray light mitigation strategies prior to implementation.

  9. Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST) (United States)

    Jacobson, C. M.; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Morton, L. A.; Thomas, M. A.


    The Thomson scattering diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser light. Stray light saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via Rayleigh scattering calibration. Furthermore, stray light contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray light levels during a vacuum vessel vent are used to identify stray light sources and strategies for reduction of stray light levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray light levels. Modeling produces qualitatively similar stray light distributions to MST measurements, and quantifies the mitigation effects of stray light mitigation strategies prior to implementation.

  10. Optical and Physicochemical Properties of Brown Carbon Aerosol: Light Scattering, FTIR Extinction Spectroscopy, and Hygroscopic Growth. (United States)

    Tang, Mingjin; Alexander, Jennifer M; Kwon, Deokhyeon; Estillore, Armando D; Laskina, Olga; Young, Mark A; Kleiber, Paul D; Grassian, Vicki H


    A great deal of attention has been paid to brown carbon aerosol in the troposphere because it can both scatter and absorb solar radiation, thus affecting the Earth's climate. However, knowledge of the optical and chemical properties of brown carbon aerosol is still limited. In this study, we have investigated different aspects of the optical properties of brown carbon aerosol that have not been previously explored. These properties include extinction spectroscopy in the mid-infrared region and light scattering at two different visible wavelengths, 532 and 402 nm. A proxy for atmospheric brown carbon aerosol was formed from the aqueous reaction of ammonium sulfate with methylglyoxal. The different optical properties were measured as a function of reaction time for a period of up to 19 days. UV/vis absorption experiments of bulk solutions showed that the optical absorption of aqueous brown carbon solution significantly increases as a function of reaction time in the spectral range from 200 to 700 nm. The analysis of the light scattering data, however, showed no significant differences between ammonium sulfate and brown carbon aerosol particles in the measured scattering phase functions, linear polarization profiles, or the derived real parts of the refractive indices at either 532 or 402 nm, even for the longest reaction times with greatest visible extinction. The light scattering experiments are relatively insensitive to the imaginary part of the refractive index, and it was only possible to place an upper limit of k ≤ 0.01 on the imaginary index values. These results suggest that after the reaction with methylglyoxal the single scattering albedo of ammonium sulfate aerosol is significantly reduced but that the light scattering properties including the scattering asymmetry parameter, which is a measure of the relative amount of forward-to-backward scattering, remain essentially unchanged from that of unprocessed ammonium sulfate. The optical extinction properties

  11. Blue light inhibits proliferation of melanoma cells (United States)

    Becker, Anja; Distler, Elisabeth; Klapczynski, Anna; Arpino, Fabiola; Kuch, Natalia; Simon-Keller, Katja; Sticht, Carsten; van Abeelen, Frank A.; Gretz, Norbert; Oversluizen, Gerrit


    Photobiomodulation with blue light is used for several treatment paradigms such as neonatal jaundice, psoriasis and back pain. However, little is known about possible side effects concerning melanoma cells in the skin. The aim of this study was to assess the safety of blue LED irradiation with respect to proliferation of melanoma cells. For that purpose we used the human malignant melanoma cell line SK-MEL28. Cell proliferation was decreased in blue light irradiated cells where the effect size depended on light irradiation dosage. Furthermore, with a repeated irradiation of the melanoma cells on two consecutive days the effect could be intensified. Fluorescence-activated cell sorting with Annexin V and Propidium iodide labeling did not show a higher number of dead cells after blue light irradiation compared to non-irradiated cells. Gene expression analysis revealed down-regulated genes in pathways connected to anti-inflammatory response, like B cell signaling and phagosome. Most prominent pathways with up-regulation of genes were cytochrome P450, steroid hormone biosynthesis. Furthermore, even though cells showed a decrease in proliferation, genes connected to the cell cycle were up-regulated after 24h. This result is concordant with XTT test 48h after irradiation, where irradiated cells showed the same proliferation as the no light negative control. In summary, proliferation of melanoma cells can be decreased using blue light irradiation. Nevertheless, the gene expression analysis has to be further evaluated and more studies, such as in-vivo experiments, are warranted to further assess the safety of blue light treatment.

  12. Characterization of Nanocellulose Using Small-Angle Neutron, X-ray, and Dynamic Light Scattering Techniques. (United States)

    Mao, Yimin; Liu, Kai; Zhan, Chengbo; Geng, Lihong; Chu, Benjamin; Hsiao, Benjamin S


    Nanocellulose extracted from wood pulps using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and sulfuric acid hydrolysis methods was characterized by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) techniques. The dimensions of this nanocellulose (TEMPO-oxidized cellulose nanofiber (TOCN) and sulfuric acid hydrolyzed cellulose nanocrystal (SACN)) revealed by the different scattering methods were compared with those characterized by transmission electron microscopy (TEM). The SANS and SAXS data were analyzed using a parallelepiped-based form factor. The width and thickness of the nanocellulose cross section were ∼8 and ∼2 nm for TOCN and ∼20 and ∼3 nm for SACN, respectively, where the fitting results from SANS and SAXS profiles were consistent with each other. DLS was carried out under both the VV mode with the polarizer and analyzer parallel to each other and the HV mode having them perpendicular to each other. Using rotational and translational diffusion coefficients obtained under the HV mode yielded a nanocellulose length qualitatively consistent with that observed by TEM, whereas the length derived by the translational diffusion coefficient under the VV mode appeared to be overestimated.

  13. Light scattering and absorption by fractal-like carbonaceous chain aggregates: comparison of theories and experiment. (United States)

    Chakrabarty, Rajan K; Moosmüller, Hans; Arnott, W Patrick; Garro, Mark A; Slowik, Jay G; Cross, Eben S; Han, Jeong-Ho; Davidovits, Paul; Onasch, Timothy B; Worsnop, Douglas R


    This study compares the optical coefficients of size-selected soot particles measured at a wavelength of 870 nm with those predicted by three theories, namely, Rayleigh-Debye-Gans (RDG) approximation, volume-equivalent Mie theory, and integral equation formulation for scattering (IEFS). Soot particles, produced by a premixed ethene flame, were size-selected using two differential mobility analyzers in series, and their scattering and absorption coefficients were measured with nephelometry and photoacoustic spectroscopy. Scanning electron microscopy and image processing techniques were used for the parameterization of the structural properties of the fractal-like soot aggregates. The aggregate structural parameters were used to evaluate the predictions of the optical coefficients based on the three light-scattering and absorption theories. Our results show that the RDG approximation agrees within 10% with the experimental results and the exact electromagnetic calculations of the IEFS theory. Volume-equivalent Mie theory overpredicts the experimental scattering coefficient by a factor of approximately 3.2. The optical coefficients predicted by the RDG approximation showed pronounced sensitivity to changes in monomer mean diameter, the count median diameter of the aggregates, and the geometric standard deviation of the aggregate number size distribution.

  14. Simulation of light scattering for surfaces with statistically distributed subwavelength cavities (United States)

    Tausendfreund, A.; Patzelt, S.; Mader, D.; Simon, S.; Goch, G.


    This paper deals with an efficient computation method for scattered light intensity distributions, which occur, if a nanostructured surface is illuminated with a monochromatic laser beam of several millimeters in diameter. The minimization of the computational amount is an essential precondition in connection with the development of powerful design tools for laser optical surface measuring methods, which derive structure characterizing attributes from structure dependent scattering effects. The presented approach differs from concepts based on near-field solutions of the Maxwell equations (finite element methods (FEM), finite difference time domain methods (FDTD)) or approximation methods for the near-field (Discrete Dipole Approximation (DDA), Generalized Multipole Technique (GMT)) as the near-field is not computed. Instead, an electrically equivalent model based on pre-computed radiation sources like Huygens point sources, dipoles, quadrupoles, etc. is used, which for standard geometrical nanostructures (cylindrical holes, spheres and ellipsoids) leads to the same far-field distributions as the conventional methods. In order to simulate the scattered light by an arbitrary surface it is divided into subwavelength geometries, which can be substituted by electrically equivalent dipole radiation sources. The far-field is calculated with a numerical scalar method. The computational effort is much smaller compared to algorithms based on the solution of Maxwell's equations.

  15. Area densitometry using rotating Scheimpflug photography for posterior capsule opacification and surface light scattering analyses. (United States)

    Minami, Keiichiro; Honbo, Masato; Mori, Yosai; Kataoka, Yasushi; Miyata, Kazunori


    To compare area densitometry analysis using rotating Scheimpflug photography in quantifications of posterior capsule opacification (PCO) and surface light scattering with previous anterior-segment analyzer measurement. Miyata Eye Hospital, Miyazaki, Japan. Prospective observational case series. Scheimpflug images of eyes with foldable intraocular lenses (IOLs) were obtained using rotating and fixed Scheimpflug photography. Area densitometry on the posterior and anterior surfaces was conducted for PCO and surface light scattering analyses, respectively, with an identical area size. Correlation between two measurements was analyzed using linear regression. The study included 105 eyes of 74 patients who received IOLs 1 to 18 years (mean, 4.9 ± 4.5 years) postoperatively. In the PCO analysis on the posterior IOL surface, there was a significant correlation between the two measurements (P photography exhibited saturation due to intensive scatterings. Area densitometry combined with a rotating Scheimpflug photography was exchangeable to previously established densitometry measurement, and allowed successive evaluation in longer-term observations. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  16. Development and Characterization of Dynamic Light Scattering Instrumentation to Determine Nanoparticle Size (United States)

    Harding, Sam; Harding, Jacob; Holman, Kate; Sebastian, Tj; Simpson, Jeff

    Dynamic Light Scattering (DLS) provides a high-throughput and accurate measurement of particle sizes for monodisperse (MD), spherical nanoparticles (NPs). We report on the development and characterization of homebuilt DLS instrumentation to measure the size of MD NPs of gold and polystyrene. HeNe and Ar-ion lasers comprise the excitation sources for the scattering experiment. An avalanche photodiode detects the scattered light and an autocorrelation card analyzes the signal to provide a measurement of the translational diffusion coefficient, which allows for the determination of NP diameter. We have tested our apparatus using commercially-produced gold NPs in the range of 10nm to 200nm. Given the strong temperature-dependence of the viscosity, periodic ambient temperature measurements were used to produce dynamic values for viscosity and hence minimize uncertainty in the determination of NP size. Additionally, we will compare our DLS results to NP size measurements obtained by Atomic Force Microscopy (AFM). S.H., K.H., T.J.S. and J.H. acknowledge support from Towson University. J.R.S. acknowledges support from NSF - CBET #1236083.

  17. [Research on particle size and size distribution of nanocrystals in urines by laser light scattering method]. (United States)

    Wan, Mu-Hua; Zhao, Mei-Xia; Ouyang, Jian-Ming


    In the present paper laser light scattering method was used to investigate the particle size and size distribution of nanoparticles simultaneously in urines of lithogenic patients and healthy persons. This method is economic, rapid, accurate and easy to operate. The results showed that healthy urines are more stable than lithogenic urines. In urines of healthy human, the ultrafine crystals were well scattered and not aggregated with a smaller size. However, the ultrafine crystals in lithogenic urine have a broad size distribution, which increases the aggregation trend of nanocrystals. Based on the intensity-autocorrelation curve, the stability of urine samples of both healthy human and lithogenic patients was comparatively investigated. The relationship between the measurement results and the methods of handling sample was studied. The results show that a stable urine sample can be obtained by diluting the urine with a ratio of 20%, then centrifuging it at 4,000 round per minute for 15 minutes or filtrating it with 1.2 microm cellulose acetate filter. The results of laser light scattering method are consistent with that obtained by transmission electron microscopy (TEM). The reasons for the stability of urines are explained from the points of Van der Waals force, urine viscosity, pH value, ionic strength, surface charge and zeta potential of the ultrafine crystals, and so on. The results in this paper provide a new thought for preventing formation and recurrence of urinary stones.

  18. Sub-diffusive spatial frequency domain imaging: light scattering as a biomarker (Conference Presentation) (United States)

    McClatchy, David M.; Rizzo, Elizabeth J.; Kanick, Stephen C.; Krishnaswamy, Venkataramanan; Elliott, Jonathan T.; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.


    In spatial frequency domain imaging (SFDI), a spatially modulated intensity pattern is projected on to tissue, with the demodulated reflectance having more superficial sensitivity with increasing spatial modulation frequency. With sub-diffusive SFDI, very high (>0.5 mm-1) spatial modulation frequencies are projected yielding sensitivity to the directionality of light scattering with only few scattering events occurring and sub-millimeter penetration depth and spatial resolution. This technique has been validated in a series of phantom experiments, where fractal distributions of polystyrene spheres were imaged, and through a model based inversion, the size scale distribution versus overall density of these particles could be separated and visualized in spatially resolved maps. With sensitivity to localized light scattering over a wide field of view (11 cm x 14 cm), this technique is being translated for the application of intraoperative breast tumor margin assessment. To test sensitivity to changes in human breast tissue morphology, a cohort of over 30 freshly excised human breast tissue specimens, including adipose, fibroglandular, fibroadenoma, and invasive carcinoma, have been imaged and co-registered to whole specimen histology. Statistical analysis of the distributions of both textual raw reflectance parameters and model based optical properties for each type of tissue will be presented. Furthermore, classification algorithm development and analysis to predicted likelihood of cancer on the surface of the tissue will also be presented. Reflectance maps, optical property maps, and probability likelihood maps of spatially heterogeneous samples with multiple tissue types will also be shown.

  19. A study into light scattering and absorption by aluminum nanoparticles in PETN (United States)

    Aduev, B.; Nurmukhametov, D.; Zvekov, A.; Nikitin, A.


    The paper is devoted to experimental and theoretical research into nanopartides' optic properties in pentaerythritol tetranitrate (petn) matrix. A photometric sphere was applied for the transmittance and sum of transmittance and reflectance measurement of petn pressed pellets containing aluminum nanoparticles at the light wavelength 643 nm. The theory of light propagation in terms of spherical harmonics solution of radiative transfer equation in the slab geometry with Fresnel boundary conditions was developed. The properties of aluminum nanoparticles were evaluated in terms of Mie theory. The absorbed energy distribution inside the sample was calculated. It was shown that the Beer's type law is applicable approximately. The apparent light absorption cross section determined, which takes into account both scattering and absorption, is bigger than the geometrical one. The aluminum refractive index value, estimated during comparison of theory with the experimental data, agrees well with the handbook's data.

  20. Enhanced photoluminescence of Si nanocrystals-doped cellulose nanofibers by plasmonic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Hiroshi [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary Street, Boston, Massachusetts 02215 (United States); Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Zhang, Ran [Division of Materials Science and Engineering, Boston University, 15 Saint Mary' s Street, Brookline, Massachusetts 02446 (United States); Reinhard, Björn M. [Department of Chemistry and Photonics Center, Boston University, Boston, Massachusetts 02215 (United States); Fujii, Minoru [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Perotto, Giovanni; Marelli, Benedetto; Omenetto, Fiorenzo G. [Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155 (United States); Dal Negro, Luca, E-mail: [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary Street, Boston, Massachusetts 02215 (United States); Division of Materials Science and Engineering, Boston University, 15 Saint Mary' s Street, Brookline, Massachusetts 02446 (United States)


    We report the development of bio-compatible cellulose nanofibers doped with light emitting silicon nanocrystals and Au nanoparticles via facile electrospinning. By performing photoluminescence (PL) spectroscopy as a function of excitation wavelength, we demonstrate plasmon-enhanced PL by a factor of 2.2 with negligible non-radiative quenching due to plasmon-enhanced scattering of excitation light from Au nanoparticles to silicon nanocrystals inside the nanofibers. These findings provide an alternative approach for the development of plasmon-enhanced active systems integrated within the compact nanofiber geometry. Furthermore, bio-compatible light-emitting nanofibers prepared by a cost-effective solution-based processing are very promising platforms for biophotonic applications such as fluorescence sensing and imaging.

  1. Characterization of Ag/Pt core-shell nanoparticles by UV-vis absorption, resonance light-scattering techniques. (United States)

    Chen, Langxing; Zhao, Wenfeng; Jiao, Yufen; He, Xiwen; Wang, Jing; Zhang, Yukui


    The water-soluble Ag/Pt core-shell nanoparticles were prepared by deposition Pt over Ag colloidal seeds with the seed-growth method using K2PtCl4 with trisodium citrate as reduced agent. The Ag:Pt ratio is varied from 9:1 to 1:3 for synthesizing Pt shell layer of different thickness. A remarkable shift and broadening of Ag surface plasmon band around 410 nm was observed. The contrast of TEM images of Ag/Pt colloids has been obtained. Various techniques, such as transmission electron microscopy (TEM), UV-vis absorption and resonance light-scattering spectroscopy were used to characterize nanoparticles. The data of TEM, UV-vis and resonance light-scattering spectrum all confirm formation of Ag/Pt core-shell nanoparticles. Resonance light-scattering and emission spectrum show the Ag and Ag/Pt core-shell nanoparticles have a nonlinear light-scattering characteristic.

  2. Improving scattering layer through mixture of nanoporous spheres and nanoparticles in ZnO-based dye-sensitized solar cells. (United States)

    Kim, Chohui; Choi, Hongsik; Kim, Jae Ik; Lee, Sangheon; Kim, Jinhyun; Lee, Woojin; Hwang, Taehyun; Kang, Suji; Moon, Taeho; Park, Byungwoo


    A scattering layer is utilized by mixing nanoporous spheres and nanoparticles in ZnO-based dye-sensitized solar cells. Hundred-nanometer-sized ZnO spheres consisting of approximately 35-nm-sized nanoparticles provide not only effective light scattering but also a large surface area. Furthermore, ZnO nanoparticles are added to the scattering layer to facilitate charge transport and increase the surface area as filling up large voids. The mixed scattering layer of nanoparticles and nanoporous spheres on top of the nanoparticle-based electrode (bilayer geometry) improves solar cell efficiency by enhancing both the short-circuit current (J sc) and fill factor (FF), compared to the layer consisting of only nanoparticles or nanoporous spheres.

  3. Fundamental study for scattering suppression in biological tissue using digital phase-conjugate light with intensity modulation (United States)

    Toda, Sogo; Kato, Yuji; Kudo, Nobuki; Shimizu, Koichi


    For transillumination imaging of an animal body, we have attempted to suppress the scattering effect in a turbid medium. It is possible to restore the optical image before scattering using phase-conjugate light. We examined the effect of intensity information as well as the phase information for the restoration of the original light distribution. In an experimental analysis using animal tissue, the contributions of the phase- and the intensity-information to the image restoration through turbid medium were demonstrated.

  4. Detection of Changes on and below the Surface in Epithelium Mucosal Tissue Structure using Scattered Light (United States)

    Taslidere, Ezgi

    The aim of this work is to answer the question of whether it is possible to detect changes on and below the surface in epithelium tissue structure using light reflected from the tissue over an area (2-D scan) illuminated by an optical sensor (fiber) emitting light at either one wavelength or with white light. Towards that end we model the 2-D reflected scans using a Stochastic Decomposition Method (SDM). The emphasis in this work is on the novelty of the proposed model and its theoretical pinning and foundation. The model is biologically motivated by the stochastic textural nature of the tissue. We model the textural content (which relates to tissue morphology) that manifests itself in the 2-D scans. Unlike previous works that analyze the scattered signal at one spot at various wavelengths, our method statistically analyzes 2-D scans of light scattering data over an area, and extracts from the data features (SDM parameters) that change with changes in the tissue morphology. The examination of an area rather than a spot not only leads to a more reliable calculation of the extracted parameters using single techniques (e.g. nuclear size distribution), but it also leads to the computation of additional information embedded in the spatial texture that our decomposition technique arrives at by modeling the hidden correlations that are obtained only by interrogating a wide sample area. To the best of our knowledge, this is the first attempt at modeling the scattered light over an area using a stochastic decomposition model that allows for the assessment of correlation and textural characteristics that otherwise could not be revealed when the analysis of the scattering signal is a function of wavelength or angle. We also come up with a segmentation technique to raise a flag on the fly when a transition occurs between different mucosal architectures on the surface. The segmentation is based on a novel difference metric for detecting an abrupt change in the parameters

  5. Energy-dependent microscopic optical potential for scattering of nucleons on light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Farag, M.Y.H.; Esmael, E.H. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Maridi, H.M. [Cairo University, Physics Department, Faculty of Science, Giza (Egypt); Taiz University, Physics Department, Faculty of Applied Science, Taiz (Yemen)


    We present an energy-dependent microscopic optical model potential for elastic scattering of nucleons on light nuclei. The single-folding model is used for the real part of the optical potential (OP), while the imaginary part is derived within the high-energy approximation theory. The energy dependence of the OP is determined from the parameterization of the volume integrals those calculated from the best-fit OP that fit the experimental data of the cross sections and analyzing powers. This energy-dependent OP is successfully applied to analyze the proton elastic scattering of {sup 4,6,i8}He, {sup 6,7}Li, and {sup 9,10}Be nuclei at low and intermediate incident energies up to 200MeV/nucleon. (orig.)

  6. Investigating the microstructure of a yield-stress fluid by light scattering (United States)

    Lee, David; Gutowski, Iris A.; Bailey, Arthur E.; Rubatat, Laurent; de Bruyn, John R.; Frisken, Barbara J.


    We report the results of an experimental study of the microstructure of dispersions of Carbopol ETD 2050, a model yield-stress fluid. Using two different light scattering instruments, measurements were made over three decades in scattering wave vector, from 0.02 to 25 μm-1. These measurements reveal microstructure characterized by two length scales: a longer length scale, 6μm and larger, that depends on Carbopol concentration and the pH of the dispersion and a shorter length scale of approximately 400 nm that is independent of both sample concentration and pH. We relate these results to shear rheology measurement of the yield stress of these materials.


    Directory of Open Access Journals (Sweden)

    Tirshu M.


    Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

  8. Analysis of Dragon's Breath and Scattered Light Detector Anomalies on WFC3/UVIS (United States)

    Fowler, Julia; Markwardt, Larissa; Bourque, Matthew; Anderson, Jay


    We summarize the examination of the light anomalies known as Dragon's Breath and Scattered Light for the UVIS channel of Wide Field Camera 3 (WFC3) of the Hubble Space Telescope (HST). We present three methods for WFC3 users to help avoid these effects during observation planning. We analyzed all of the full-frame wide and long pass filters with exposure times ≥ 300 seconds, comprising ∼13% of WFC3/UVIS on-orbit data (∼20% of all full-frame data, and ∼35% of all full-frame ≥300 second exposures.) We find that stars producing Dragon's Breath peak at specific orientations to the detector and V-band magnitudes. The bulk of these stars fall along the vertical and horizontal edges, within ∼490 pixels of the image frame. The corners of the detector show significantly fewer instances of Dragon's Breath and Scattered Light, though still a few occurrences. Furthermore, matching stars outside the field of the image to V-band magnitude data from the Hubble Guide Star Catalog II (GSC-II) shows that stars causing the anomaly consistently peak around a V-band magnitude of 11.9 or 14.6, whereas the general trend of objects lying outside the field instead peaks around a magnitude of 16.5 within our exposure time and filter selection.

  9. DaMaSCUS: the impact of underground scatterings on direct detection of light dark matter (United States)

    Emken, Timon; Kouvaris, Chris


    Conventional dark matter direct detection experiments set stringent constraints on dark matter by looking for elastic scattering events between dark matter particles and nuclei in underground detectors. However these constraints weaken significantly in the sub-GeV mass region, simply because light dark matter does not have enough energy to trigger detectors regardless of the dark matter-nucleon scattering cross section. Even if future experiments lower their energy thresholds, they will still be blind to parameter space where dark matter particles interact with nuclei strongly enough that they lose enough energy and become unable to cause a signal above the experimental threshold by the time they reach the underground detector. Therefore in case dark matter is in the sub-GeV region and strongly interacting, possible underground scatterings of dark matter with terrestrial nuclei must be taken into account because they affect significantly the recoil spectra and event rates, regardless of whether the experiment probes DM via DM-nucleus or DM-electron interaction. To quantify this effect we present the publicly available Dark Matter Simulation Code for Underground Scatterings (DaMaSCUS), a Monte Carlo simulator of DM trajectories through the Earth taking underground scatterings into account. Our simulation allows the precise calculation of the density and velocity distribution of dark matter at any detector of given depth and location on Earth. The simulation can also provide the accurate recoil spectrum in underground detectors as well as the phase and amplitude of the diurnal modulation caused by this shadowing effect of the Earth, ultimately relating the modulations expected in different detectors, which is important to decisively conclude if a diurnal modulation is due to dark matter or an irrelevant background.

  10. Light scattering and transmission measurement using digital imaging for online analysis of constituents in milk (United States)

    Jain, Pranay; Sarma, Sanjay E.


    Milk is an emulsion of fat globules and casein micelles dispersed in an aqueous medium with dissolved lactose, whey proteins and minerals. Quantification of constituents in milk is important in various stages of the dairy supply chain for proper process control and quality assurance. In field-level applications, spectrophotometric analysis is an economical option due to the low-cost of silicon photodetectors, sensitive to UV/Vis radiation with wavelengths between 300 - 1100 nm. Both absorption and scattering are witnessed as incident UV/Vis radiation interacts with dissolved and dispersed constituents in milk. These effects can in turn be used to characterize the chemical and physical composition of a milk sample. However, in order to simplify analysis, most existing instrument require dilution of samples to avoid effects of multiple scattering. The sample preparation steps are usually expensive, prone to human errors and unsuitable for field-level and online analysis. This paper introduces a novel digital imaging based method of online spectrophotometric measurements on raw milk without any sample preparation. Multiple LEDs of different emission spectra are used as discrete light sources and a digital CMOS camera is used as an image sensor. The extinction characteristic of samples is derived from captured images. The dependence of multiple scattering on power of incident radiation is exploited to quantify scattering. The method has been validated with experiments for response with varying fat concentrations and fat globule sizes. Despite of the presence of multiple scattering, the method is able to unequivocally quantify extinction of incident radiation and relate it to the fat concentrations and globule sizes of samples.

  11. Attenuation, scattering, and depolarization of light by gold nanorods with silver shells (United States)

    Khlebtsov, B. N.; Khanadeev, V. A.; Khlebtsov, N. G.


    Gold nanoparticles with silver nanoshells are obtained by synthesizing gold nanorods in a growing solution containing cetyltrimethylammonium bromide, subsequent separation in a concentration gradient of glycerol, and reduction of silver nitrate by ascorbic acid under alkaline conditions in the presence of polyvinylpyrrolidone. The formation of silver nanoshells was monitored by the shift of plasmon resonances of extinction and differential light scattering, by the appearance of characteristics peaks of silver in the energy dispersive X-ray (EDX) spectra of samples, by the data of transmission electron microscopy, and by visual changes in the color of colloids. The spectrum of the intensity ratio of the co- and cross-polarized compo- nents of light scattered by gold-silver nanorods is measured for the first time, and it is observed that the maximum is shifted by 80-100 nm compared to previously published spectra of gold nanorods (Khlebtsov et al., J. Phys. Chem. C 112, 12760 (2008)). The extinction and light scattering spectra are calculated by the method of separation of variables using the model of a confocal two-layer spheroid and these calculations are found to agree with spectral measurements. A method for determining the thickness of a silver nanolayer by the spectral shift of an extinction longitudinal resonance is described. The obtained data of optical spectroscopy and transmission electron microscopy and estimations of the mass of the deposited metal show that the aver-age thickness of the silver layer varies from 0.12 to 4 nm as the Ag/Au ratio changes from 2/80 to 90/80 μg/μg.

  12. Improvement of photon management in partial rear contact solar cells using a combination of DBR and Mie scatterers (United States)

    Mitra, Suchismita; Ghosh, Hemanta; Saha, Hiranmay; Kumar Datta, Swapan; Chaudhuri, Partha; Banerjee, Chandan


    In this article, we present systematic simulations and numerical analysis of a novel light trapping scheme in a partial rear contact (PRC) solar cell involving a combined effect of rear located Distributed Bragg Reflectors (DBRs) and Mie scatterers comprising of dielectric nanoparticles (DNP), thereby, enhancing the efficiency of the device. We have studied the effect of three different types of DBRs in combination with embedded silica (SiO2) DNPs which scatter light into silicon substrate of PRC c-Si solar cell. The materials for DBRs are chosen in such a way that they may serve the dual purpose of reflecting more than 90% of incident light at the rear surface and passivating it as well. The internal reflection from the rear surface, absorption enhancement ratio and average scattering angle have been computed from 3-dimensional finite difference time domain (FDTD) simulations and performing numerical analysis later on. Further, these results are used in the analysis of basic solar cell to extract the parameters like short circuit current density, open circuit voltage, fill factor, reverse saturation current density and efficiency of solar cell. It has been observed that significant increase in efficiency can be achieved for solar cells having 10-100 μm thick substrates by incorporating this light trapping scheme. Beyond 100 μm thickness, the conversion efficiency approaches a saturation value. Moreover, a combination of DBR with silica nanoparticles results in maximum efficiency near 50 μm thickness of solar cell thereby improving the baseline efficiency from 20.3% to an absolute value of 22.9%. This study opens up a new perspective of light management using the advantages of highly reflective DBRs and highly scattering DNPs which can be incorporated in a rather simple and inexpensive way for thin (<100 μm) silicon solar cells.

  13. Elastic properties of boron carbide films via surface acoustic waves measured by Brillouin light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Salas, E.; Jimenez-Villacorta, F.; Jimenez Rioboo, R.J.; Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Sanchez-Marcos, J. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Munoz-Martin, A.; Prieto, J.E.; Joco, V. [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)


    Surface acoustic wave (SAW) velocity has been determined by high resolution Brillouin light scattering to study the mechano-elastic properties of boron carbide films prepared by radio frequency (RF) sputtering. The comparison of experimentally observed elastic behaviour with simulations made by considering film composition obtained from elastic recoil detection analysis-time of flight (ERDA-ToF) spectroscopy allows establishing that elastic properties are determined by that of crystalline boron carbide with a lessening of the SAW velocity values due to surface oxidation. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Brillouin light scattering from shear waves in an epoxy resin through the glass transition (United States)

    Comez, L.; Fioretto, D.; Verdini, L.; Rolla, P. A.


    The temperature dependences of the characteristic frequency and lifetime of hypersonic transverse acoustic waves in the epoxy system EPON 828 have been probed by means of the Brillouin light scattering technique. Evidence has been found of a very broad dispersion region, together with a discontinuity close to the glass transition temperature 0953-8984/9/19/016/img7. For temperatures higher than 0953-8984/9/19/016/img7, the shear loss data obtained from Brillouin spectra are in quantitative agreement with dielectric data for the same system. For lower temperatures, the Brillouin data deviate from the dielectric ones, the former being more sensitive to the secondary relaxation processes.

  15. Characterization of a large glycoprotein proteoglycan by size-exclusion chromatography combined with light and X-ray scattering methods. (United States)

    Watanabe, Yasushi; Inoko, Yoji


    The molecular weight and chain conformation of a proteoglycan derived from shark cartilage in solution were characterized by size-exclusion chromatography combined with low-angle laser light scattering and small-angle X-ray scattering methods. The total molecular weight of the proteoglycan was 3.9±0.2 million and the molecular weight of the main component was about 2.0±0.2 million. The X-ray scattering data revealed that the main components of the proteoglycan are nearly equal to a chain with excluded volume and their persistence lengths range from 13.5 to 16.4nm. These results show that size-exclusion chromatography combined with low-angle laser light scattering and small-angle X-ray scattering measurements are complementarily useful for characterization of large biopolymers in solution. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Scattering Intensity and Directionality Probed Along Individual Zinc Oxide Nanorods with Precisely Controlled Light Polarization and Nanorod Orientation

    Directory of Open Access Journals (Sweden)

    Daniel S. Choi


    Full Text Available We elucidated the light-matter interaction of individual ZnO NRs with a monochromatic beam of linearly polarized light that scatters elastically from the ZnO NRs by performing forward scattering and back-aperture imaging in a dark-field setting. We precisely controlled the electric field vector of the incident light and the NR orientation within the plane of light interaction during both modes of measurement, and spatially resolved the scattering response from different interaction points along the NR long axis. We then discerned, for the first time, the effects of light polarization, analyzer angle, and NR orientation on the intensity and directionality of the optical responses both qualitatively and quantitatively along the length of the single ZnO NRs. We identified distinctive scattering profiles from individual ZnO NRs subject to incident light polarization with controlled NR orientation from the forward dark-field scattering and back-aperture imaging modes. The fundamental light interaction behavior of ZnO NRs is likely to govern their functional outcomes in photonics, optoelectronics, and sensor devices. Hence, our efforts provided much needed insight into unique optical responses from individual 1D ZnO nanomaterials, which could be highly beneficial in developing next-generation optoelectronic systems and optical biodetectors with improved device efficiency and sensitivity.

  17. Unidirectional and bidirectional light beam splitting in photonic crystal with elliptical and circular scatterers (United States)

    Feng, Shuai


    The light beam splitting characters of the two-dimensional asymmetric photonic crystal structures are studied, which are composed of elliptical and circular silicon rods immersed in air. Through interlacing the elliptical and circular silicon rods along the interface of the two photonic crystals, the unidirectional light splitting phenomena are achieved, where the light beam propagates towards two opposite directions within different frequency regions. A bidirectional three-channel light beam splitting behavior is also observed within another frequency region. The light transmission characters can be altered by rotating the elliptical rods in the unit cell. The unidirectional three-output-channel beam splitting behavior is achieved, while the light beam propagating along the opposite direction experiences a self-collimation behavior and keeps its transmitting direction unchanged.

  18. On the Scalar Scattering Theory for Thin-Film Solar Cells

    NARCIS (Netherlands)

    Jäger, K.


    Nano-textured interfaces between two media of different refractive indices scatter light. The angular distribution and the intensity of the scattered light are deter- mined by the geometry of the nano-textures and the difference of the refractive indices of the two media. Thin-film silicon solar

  19. Discrimination between Doppler-shifted and non-shifted light in coherence domain path length resolved measurements of multiply scattered light

    NARCIS (Netherlands)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt


    We show a novel technique to distinguish between Doppler shifted and unshifted light in multiple scattering experiments on mixed static and dynamic media. With a phase modulated low coherence Mach- Zehnder interferometer, optical path lengths of shifted and unshifted light and path length dependent

  20. Feasibility Study of an Optical Caustic Plasmonic Light Scattering Sensor for Human Serum Anti-Dengue Protein E Antibody Detection. (United States)

    García, Antonio A; Franco, Lina S; Pirez-Gomez, Miguel A; Pech-Pacheco, José L; Mendez-Galvan, Jorge F; Machain-Williams, Carlos; Talavera-Aguilar, Lourdes; Espinosa-Carrillo, José H; Duarte-Villaseñor, Miriam M; Be-Ortiz, Christian; Espinosa-de Los Monteros, Luz E; Castillo-Pacheco, Ariel; Garcina-Rejon, Julian E


    Antibody detection and accurate diagnosis of tropical diseases is essential to help prevent the spread of disease. However, most detection methods lack cost-effectiveness and field portability, which are essential features for achieving diagnosis in a timely manner. To address this, 3D-printed oblate spheroid sample chambers were fabricated to measure green light scattering of gold nanoparticles using an optical caustic focus to detect antibodies. Scattering signals of 20-200 nm gold nanoparticles using a green laser were compared to green light emitting diode (LED) light source signals and to Mie theory. The change in signal from 60 to 120 nm decreased in the order of Mie Theory > optical caustic scattering > 90° scattering. These results suggested that conjugating 60 nm gold nanoparticles and using an optical caustic system to detect plasmonic light scattering, would result in a sensitive test for detecting human antibodies in serum. Therefore, we studied the light scattering response of conjugated gold nanoparticles exposed to different concentrations of anti-protein E antibody, and a feasibility study of 10 human serum samples using dot blot and a handheld optical caustic-based sensor device. The overall agreement between detection methods suggests that the new sensor concept shows promise to detect gold nanoparticle aggregation in a homogeneous assay. Further testing and protocol optimization is needed to draw conclusions on the positive and negative predictive values for this new testing system.

  1. Feasibility Study of an Optical Caustic Plasmonic Light Scattering Sensor for Human Serum Anti-Dengue Protein E Antibody Detection (United States)

    García, Antonio A.; Pirez-Gomez, Miguel A.; Pech-Pacheco, José L.; Mendez-Galvan, Jorge F.; Machain-Williams, Carlos; Talavera-Aguilar, Lourdes; Espinosa-Carrillo, José H.; Duarte-Villaseñor, Miriam M.; Be-Ortiz, Christian; Espinosa-de los Monteros, Luz E.; Castillo-Pacheco, Ariel; Garcia-Rejon, Julian E.


    Antibody detection and accurate diagnosis of tropical diseases is essential to help prevent the spread of disease. However, most detection methods lack cost-effectiveness and field portability, which are essential features for achieving diagnosis in a timely manner. To address this, 3D-printed oblate spheroid sample chambers were fabricated to measure green light scattering of gold nanoparticles using an optical caustic focus to detect antibodies. Scattering signals of 20–200 nm gold nanoparticles using a green laser were compared to green light emitting diode (LED) light source signals and to Mie theory. The change in signal from 60 to 120 nm decreased in the order of Mie Theory > optical caustic scattering > 90° scattering. These results suggested that conjugating 60 nm gold nanoparticles and using an optical caustic system to detect plasmonic light scattering, would result in a sensitive test for detecting human antibodies in serum. Therefore, we studied the light scattering response of conjugated gold nanoparticles exposed to different concentrations of anti-protein E antibody, and a feasibility study of 10 human serum samples using dot blot and a handheld optical caustic-based sensor device. The overall agreement between detection methods suggests that the new sensor concept shows promise to detect gold nanoparticle aggregation in a homogeneous assay. Further testing and protocol optimization is needed to draw conclusions on the positive and negative predictive values for this new testing system. PMID:28817080

  2. Frequency-modulated light scattering interferometry employed for optical properties and dynamics studies of turbid media (United States)

    Mei, Liang; Somesfalean, Gabriel; Svanberg, Sune


    In the present work, fiber-based frequency-modulated light scattering interferometry (FMLSI) is developed and employed for studies of optical properties and dynamics in liquid phantoms made from Intralipid®. The fiber-based FMLSI system retrieves the optical properties by examining the intensity fluctuations through the turbid medium in a heterodyne detection scheme using a continuous-wave frequency-modulated coherent light source. A time resolution of 21 ps is obtained, and the experimental results for the diluted Intralipid phantoms show good agreement with the predicted results based on published data. The present system shows great potential for assessment of optical properties as well as dynamic studies in liquid phantoms, dairy products, and human tissues. PMID:25136504

  3. In vivo light scattering for the detection of cancerous and precancerous lesions of the cervix

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, Judith R [Los Alamos National Laboratory


    A noninvasive optical diagnostic system for detection of cancerous and precancerous lesions of the cervix was evaluated in vivo. The optical system included a fiber-optic probe designed to measure polarized and unpolarized light transport properties of a small volume of tissue. An algorithm for diagnosing tissue based on the optical measurements was developed that used four optical properties, three of which were related to light scattering properties and the fourth of which was related to hemoglobin concentration. A sensitivity of {approx}77% and specificities in the mid 60% range were obtained for separating high grade squamous intraepithelial lesions and cancer from other pathologies and normal tissue. The use of different cross-validation methods in algorithm development is analyzed, and the relative difficulties of diagnosing certain pathologies are assessed. Furthermore, the robustness of the optical system for use by different doctors and to changes in fiber-optic probe are also assessed, and potential improvements in the optical system are discussed.

  4. Structural characterization of amphiphilic homopolymer micelles using light scattering, SANS, and cryo-TEM. (United States)

    Patterson, Joseph P; Kelley, Elizabeth G; Murphy, Ryan P; Moughton, Adam O; Robin, Mathew; Lu, Annhelen; Colombani, Olivier; Chassenieux, Christophe; Cheung, David; Sullivan, Millicent O; Epps, Thomas H; O'Reilly, Rachel K


    We report the aqueous solution self-assembly of a series of poly(N-isopropylacrylamide) (PNIPAM) polymers end-functionalized with a hydrophobic sulfur-carbon-sulfur (SCS) pincer ligand. Although the hydrophobic ligand accounted for structural details were investigated using light scattering, cryogenic transmission electron microscopy (cryo-TEM), and small angle neutron scattering (SANS). Radial density profiles extracted from the cryo-TEM micrographs suggested that the PNIPAM chains formed a diffuse corona with a radially decreasing corona density profile and provided valuable a priori information about the micelle structure for SANS data modeling. SANS analysis indicated a similar profile in which the corona surrounded a small hydrophobic core containing the pincer ligand. The similarity between the SANS and cryo-TEM results demonstrated that detailed information about the micelle density profile can be obtained directly from cryo-TEM and highlighted the complementary use of scattering and cryo-TEM in the structural characterization of solution-assemblies, such as the SCS pincer-functionalized homopolymers described here.

  5. Metamaterial-based theoretical description of light scattering by metallic nano-hole array structures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada); Najiminaini, Mohamadreza; Carson, Jeffrey J. L. [Lawson Health Research Institute, St. Joseph' s Health Care, 268 Grosvenor Street, London N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London N6A 3K7 (Canada); Balakrishnan, Shankar [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada); Lawson Health Research Institute, St. Joseph' s Health Care, 268 Grosvenor Street, London N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London N6A 3K7 (Canada)


    We have experimentally and theoretically investigated the light-matter interaction in metallic nano-hole array structures. The scattering cross section spectrum was measured for three samples each having a unique nano-hole array radius and periodicity. Each measured spectrum had several peaks due to surface plasmon polaritons. The dispersion relation and the effective dielectric constant of the structure were calculated using transmission line theory and Bloch's theorem. Using the effective dielectric constant and the transfer matrix method, the surface plasmon polariton energies were calculated and found to be quantized. Using these quantized energies, a Hamiltonian for the surface plasmon polaritons was written in the second quantized form. Working with the Hamiltonian, a theory of scattering cross section was developed based on the quantum scattering theory and Green's function method. For both theory and experiment, the location of the surface plasmon polariton spectral peaks was dependant on the array periodicity and radii of the nano-holes. Good agreement was observed between the experimental and theoretical results. It is proposed that the newly developed theory can be used to facilitate optimization of nanosensors for medical and engineering applications.

  6. Green light for quantitative live-cell imaging in plants. (United States)

    Grossmann, Guido; Krebs, Melanie; Maizel, Alexis; Stahl, Yvonne; Vermeer, Joop E M; Ott, Thomas


    Plants exhibit an intriguing morphological and physiological plasticity that enables them to thrive in a wide range of environments. To understand the cell biological basis of this unparalleled competence, a number of methodologies have been adapted or developed over the last decades that allow minimal or non-invasive live-cell imaging in the context of tissues. Combined with the ease to generate transgenic reporter lines in specific genetic backgrounds or accessions, we are witnessing a blooming in plant cell biology. However, the imaging of plant cells entails a number of specific challenges, such as high levels of autofluorescence, light scattering that is caused by cell walls and their sensitivity to environmental conditions. Quantitative live-cell imaging in plants therefore requires adapting or developing imaging techniques, as well as mounting and incubation systems, such as micro-fluidics. Here, we discuss some of these obstacles, and review a number of selected state-of-the-art techniques, such as two-photon imaging, light sheet microscopy and variable angle epifluorescence microscopy that allow high performance and minimal invasive live-cell imaging in plants. © 2018. Published by The Company of Biologists Ltd.

  7. Inkjet-printed polymer-based scattering layers for enhanced light outcoupling from top-emitting organic light-emitting diodes (United States)

    Heinrichsdobler, Armin; Engelmayer, Manuel; Riedel, Daniel; Brabec, Christoph J.; Wehlus, Thomas


    High refractive index polymer-based scattering layers used as internal light extraction layers are a promising low-cost approach to enhance the luminous efficacy of organic light-emitting diodes (OLEDs). In order to avoid damaging of the OLED layers a structured and contactless deposition method for the polymer-based scattering layers is required. For enhanced lifetime of the devices the water diffusion through the scattering layer has to be eliminated by a structured patterning technique. Inkjet printing offers both a contactless and structured deposition. In this study we evaluate inkjet printing of nanocomposite polymer-based scattering layers for OLEDs. A detailed view on the material and process development is given. This involves an optimization of ink formulation, printing parameters as well as layer formation. The resulting haze values of the scattering layers at 550 nm vary between 40% and 90% for different layer thicknesses. The gain in external quantum efficacy of top-emitting OLEDs induced by light scattering compared to reference devices peaks at a factor of 2.3. The obtained results are discussed and verified by an optical volume scattering simulation model which will be presented in full detail. Also a parameter variation study and its impact on extraction efficiency will be shown.

  8. A non-invasive method for the assessment of hemostasis in vivo by using dynamic light scattering (United States)

    Fine, I.; Kaminsky, A.; Kuznik, B.; Shenkman, L.


    We present a new non-invasive method for assessing hemostasis in vivo. This method is based on the analysis of the movement characteristics of red blood cells (RBCs) during blood stasis condition. Stasis is intermittently induced by occlusion of arterial blood flow at the finger root. We assumed that under zero flow conditions, RBC movement is driven mostly by Brownian motion, and we characterized the RBC movement by utilizing the dynamic light scattering (DLS) technique in vivo. We found that during the stasis the RBCs diffusion coefficient in plasma decreases. We speculate that the RBC diffusion coefficient is most strongly related to endothelial and hemostatic activity. This assumption is supported by our findings that RBC movement, being expressed through the characteristics of the measured DLS signal, is correlative to the biological age and also is related to the coagulation factors. This new method can serve as a new diagnostic and research tool for the assessment of hemostasis and vascular function.

  9. Impact of Polarizing Non-Lambertian Surface and Volume Scattering on Polarized Light Signatures: Importance to Remote Sensing (United States)


    polarized light. Although thermal radiation is initially unpolarized when emitted in the atmosphere, it becomes polarized by scattering processes with...light. Utilization of the polarized bi-directional reflection capabilities in VDISORT-MOD5 will enhance our understanding of the interaction fundamental spectral signature development, surface modeling, experimental validation, synthetic image generation, and improvement of both

  10. Device reflectivity as a simple rule for predicting the suitability of scattering foils for improved OLED light extraction

    NARCIS (Netherlands)

    Levell, J.W.; Harkema, S.; Pendyala, R.K.; Rensing, P.A.; Senes, A.; Bollen, D.; MacKerron, D.; Wilson, J.S.


    A general challenge in Organic Light Emitting Diodes (OLEDs) is to extract the light efficiently from waveguided modes within the device structure. This can be accomplished by applying an additional scattering layer to the substrate which results in outcoupling increases between 0% to <100% in

  11. Characterization of enzymatically induced aggregation of casein micelles in natural concentration by in situ static light scattering and ultra low shear viscosimetry

    DEFF Research Database (Denmark)

    Lehner, D.; Worning, Peder; G, Fritz


    The aggregation of casein micelles in undiluted skim milk after the addition of chymosin was studied bystatic light scattering and ultra low shear viscometry. The static light scattering measurements were madewith two different sample thicknesses, 72 and 16 mum. The scattering data were analyzed...

  12. Here Be Dragons: Characterization of ACS/WFC Scattered Light Anomalies (United States)

    Porterfield, B.; Coe, D.; Gonzaga, S.; Anderson, J.; Grogin, N.


    We present a study characterizing scattered light anomalies that occur near the edges of Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) images. We inspected all 8,573 full-frame ACS/WFC raw images with exposure times longer than 350 seconds obtained in the F606W and F814W filters from 2002 to October 2013. We visually identified two particular scattered light artifacts known as "dragon's breath" and edge glow. Using the 2MASS point source catalog and Hubble Guide Star Catalog (GSC II), we identified the stars that caused these artifacts. The stars are all located in narrow bands ( 3" across) just outside the ACS/WFC field of view (2" - 16" away). We provide a map of these risky areas around the ACS/WFC detectors - users should avoid positioning bright stars in these regions when designing ACS/WFC imaging observations. We also provide interactive webpages which display all the image artifacts we identified, allowing users to see examples of the severity of artifacts they might expect for a given stellar magnitude at a given position relative to the ACS/WFC field of view. On average, 10th (18th) magnitude stars produce artifacts about 1,000 (100) pixels long. But the severity of these artifacts can vary strongly with small positional shifts (∼ 1"). The results are similar for both filters (F606W and F814W) when expressed in total fluence, or flux multiplied by exposure time.

  13. Molecular dynamics of supercooled ionic liquids studied by light scattering and dielectric spectroscopy (United States)

    Pabst, Florian; Gabriel, Jan; Weigl, Peter; Blochowicz, Thomas


    We investigate molecular dynamics of two supercooled room temperature ionic liquids (RTILs) above of their glass transition temperature by means of dynamic light scattering and broadband dielectric spectroscopy from nanoseconds up to ≈105s . We show that a direct comparison of the raw data of these two techniques allows us to identify the reorientation of ions in the dielectric data, giving experimental evidence to a very recently proposed model of Gainaru et al. [1], stating that the conductivity process in ionic liquids takes place through a reorientational step of ions escaping their cage formed by surrounding counterions. Within this approach we can also understand the apparent decoupling of time constants from dielectric spectroscopy and light scattering, often found in ionic liquids, in a very natural way. Furthermore, as a consequence of knowing the reorientational part of the dielectric spectrum, we are able to show that two more processes contribute to these spectra, which are due to electrode polarization effects. The relative position of all three contributions vary among the systems and may overshadow each other, thus complicating the data analysis and favor misinterpretations.

  14. Dynamic light scattering and atomic force microscopy techniques for size determination of polyurethane nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Giehl Zanetti-Ramos, Betina [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil)], E-mail:; Beddin Fritzen-Garcia, Mauricia [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil); Schweitzer de Oliveira, Cristian; Avelino Pasa, Andre [Laboratorio de Filmes Finos e Superficie, Departamento de Fisica (Brazil); Soldi, Valdir [Grupo de Estudos em Materiais Polimericos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borsali, Redouane [Centre de Recherche sur les Macromolecules Vegetales CERMAV/CNRS, 38041 - Grenoble (France); Creczynski-Pasa, Tania Beatriz [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil)


    Nanoparticles have applications in various industrial fields principally in drug delivery. Nowadays, there are several processes for manufacturing colloidal polymeric systems and methods of preparation as well as of characterization. In this work, Dynamic Light Scattering and Atomic Force Microscopy techniques were used to characterize polyurethane nanoparticles. The nanoparticles were prepared by miniemulsion technique. The lipophilic monomers, isophorone diisocyanate (IPDI) and natural triol, were emulsified in water containing surfactant. In some formulations the poly(ethylene glycol) was used as co-monomer to obtain the hydrophilic and pegylated nanoparticles. Polyurethane nanoparticles observed by atomic force microscopy (AFM) were spherical with diameter around 209 nm for nanoparticles prepared without PEG. From AFM imaging two populations of nanoparticles were observed in the formulation prepared with PEG (218 and 127 nm) while dynamic light scattering (DLS) measurements showed a monodisperse size distribution around 250 nm of diameters for both formulations. The polydispersity index of the formulations and the experimental procedures could influence the particle size determination with these techniques.

  15. Dynamic light scattering study of inhibition of nucleation and growth of hydroxyapatite crystals by osteopontin.

    Directory of Open Access Journals (Sweden)

    John R de Bruyn

    Full Text Available We study the effect of isoforms of osteopontin (OPN on the nucleation and growth of crystals from a supersaturated solution of calcium and phosphate ions. Dynamic light scattering is used to monitor the size of the precipitating particles and to provide information about their concentration. At the ion concentrations studied, immediate precipitation was observed in control experiments with no osteopontin in the solution, and the size of the precipitating particles increased steadily with time. The precipitate was identified as hydroxyapatite by X-ray diffraction. Addition of native osteopontin (nOPN extracted from rat bone caused a delay in the onset of precipitation and reduced the number of particles that formed, but the few particles that did form grew to a larger size than in the absence of the protein. Recombinant osteopontin (rOPN, which lacks phosphorylation, caused no delay in initial calcium phosphate precipitation but severely slowed crystal growth, suggesting that rOPN inhibits growth but not nucleation. rOPN treated with protein kinase CK2 to phosphorylate the molecule (p-rOPN produced an effect similar to that of nOPN, but at higher protein concentrations and to a lesser extent. These results suggest that phosphorylations are critical to OPN's ability to inhibit nucleation, whereas the growth of the hydroxyapatite crystals is effectively controlled by the highly acidic OPN polypeptide. This work also demonstrates that dynamic light scattering can be a powerful tool for delineating the mechanism of protein modulation of mineral formation.


    Energy Technology Data Exchange (ETDEWEB)

    Follette, Katherine B.; Close, Laird M. [Steward Observatory, The University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Swearingen, Jeremy R.; Sitko, Michael L.; Champney, Elizabeth H. [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Van der Marel, Nienke; Maaskant, Koen; Min, Michiel [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Takami, Michihiro [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Kuchner, Marc J; McElwain, Michael W. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Muto, Takayuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551 (Japan); Mayama, Satoshi [The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Fukagawa, Misato [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Russell, Ray W. [The Aerospace Corporation, Los Angeles, CA 90009 (United States); Kudo, Tomoyuki [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Kusakabe, Nobuhiko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hashimoto, Jun [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks St., Norman, OK 73019 (United States); Abe, Lyu [Laboratoire Lagrange, UMR7293, Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d' Azur, 28 avenue Valrose, F-06108 Nice Cedex 2 (France); and others


    We present the first resolved near-infrared imagery of the transition disk Oph IRS 48 (WLY 2-48), which was recently observed with ALMA to have a strongly asymmetric submillimeter flux distribution. H-band polarized intensity images show a ∼60 AU radius scattered light cavity with two pronounced arcs of emission, one from northeast to southeast and one smaller, fainter, and more distant arc in the northwest. K-band scattered light imagery reveals a similar morphology, but with a clear third arc along the southwestern rim of the disk cavity. This arc meets the northwestern arc at nearly a right angle, revealing the presence of a spiral arm or local surface brightness deficit in the disk, and explaining the east-west brightness asymmetry in the H-band data. We also present 0.8-5.4 μm IRTF SpeX spectra of this object, which allow us to constrain the spectral class to A0 ± 1 and measure a low mass accretion rate of 10{sup –8.5} M {sub ☉} yr{sup –1}, both consistent with previous estimates. We investigate a variety of reddening laws in order to fit the multiwavelength spectral energy distribution of Oph IRS 48 and find a best fit consistent with a younger, higher luminosity star than previous estimates.

  17. Focusing light through strongly scattering media using genetic algorithm with SBR discriminant (United States)

    Zhang, Bin; Zhang, Zhenfeng; Feng, Qi; Liu, Zhipeng; Lin, Chengyou; Ding, Yingchun


    In this paper, we have experimentally demonstrated light focusing through strongly scattering media by performing binary amplitude optimization with a genetic algorithm. In the experiments, we control 160 000 mirrors of digital micromirror device to modulate and optimize the light transmission paths in the strongly scattering media. We replace the universal target-position-intensity (TPI) discriminant with signal-to-background ratio (SBR) discriminant in genetic algorithm. With 400 incident segments, a relative enhancement value of 17.5% with a ground glass diffuser is achieved, which is higher than the theoretical value of 1/(2π )≈ 15.9 % for binary amplitude optimization. According to our repetitive experiments, we conclude that, with the same segment number, the enhancement for the SBR discriminant is always higher than that for the TPI discriminant, which results from the background-weakening effect of SBR discriminant. In addition, with the SBR discriminant, the diameters of the focus can be changed ranging from 7 to 70 μm at arbitrary positions. Besides, multiple foci with high enhancement are obtained. Our work provides a meaningful reference for the study of binary amplitude optimization in the wavefront shaping field.

  18. Solution and conformational properties of wheat beta-D-glucans studied by light scattering and viscometry. (United States)

    Li, Wei; Cui, Steve W; Wang, Qi


    The solution properties of wheat beta-glucan were investigated by light scattering and viscometric methods. The hydrodynamic radius (R(h)), weight average molecular weight (M(w)), radius of gyration (R(g)), and the second virial coefficient (A(2)) of wheat beta-glucan were determined by both dynamic and static light scattering methods, whereas the critical concentrations (c) of the solution were derived from [eta] via viscometric method. The structure sensitive parameters, rho (1.52-1.62), the conformation parameter nu (0.62), and the Mark-Houwink-Sakurada exponents alpha (0.78) confirmed the random coil conformation of wheat beta-glucan in 0.5 M NaOH solution. The characteristic ratio (4.97) was obtained by the random flight model, and the statistical segment length (8.83 nm) was derived from the wormlike cylinder model. It was found that the wormlike cylinder model could explain the chain stiffness better than the random flight model, which suggested an extended random coil conformation of wheat beta-glucan in 0.5 M NaOH solution. The study also revealed that the structure feature of wheat beta-glucan; that is, the higher trisaccharide-to-tetrasaccharide ratio contributed to the stiffer chain conformation compared with other cereal beta-glucans.

  19. Complete time-resolved polarimetry of scattered light at the National Ignition Facility (United States)

    Turnbull, David; Ayers, Shannon; Bell, Perry; Chow, Robert; Frieders, Gene; Hibbard, Robin L.; Michel, Pierre; Ralph, Joseph E.; Ross, James S.; Stanley, Joel R.; Vickers, James L.; Zeid, Ziad M.; Moody, John D.


    The 3ω scattered light polarimetry diagnostic in the 30° incidence cone backscatter diagnostic at the National Ignition Facility (NIF) is being upgraded to measure the full time-resolved Stokes vector. Previously, the diagnostic had a single channel capable of diagnosing the time-integrated balance of the horizontal and vertical polarizations. Two additional channels were added - one that measures the balance of the 45° and 135° projections, and another that measures the right- and left-circular polarizations - and together the three complete the Stokes vector measurement. A division-of-aperture scheme is employed in which three nearby portions of the near field are sampled simultaneously. Time resolution is obtained by relaying an image of the measured regions onto a set of fibers coupled to diodes. The new diagnostic will be capable of measuring scattered light signals crossed-beam energy transfer in indirect-drive inertial confinement fusion experiments. It will also be used to diagnose Faraday rotation induced by magnetic fields in collisionless shock and turbulent dynamo experiments later this year.

  20. Laser Light Scattering Diagnostic for Measurement of Flow Velocity in Vicinity of Propagating Shock Waves (United States)

    Seasholtz, Richard G.; Buggele, Alvin E.


    A laser light scattering diagnostic for measurement of dynamic flow velocity at a point is described. The instrument is being developed for use in the study of propagating shock waves and detonation waves in pulse detonation engines under development at the NASA Glenn Research Center (GRC). The approach uses a Fabry-Perot interferometer to measure the Doppler shift of laser light scattered from small (submicron) particles in the flow. The high-speed detection system required to resolve the transient response as a shock wave crosses the probe volume uses fast response photodetectors, and a PC based data acquisition system. Preliminary results of measurements made in the GRC Mach 4, 10 by 25 cm supersonic wind tunnel are presented. Spontaneous condensation of water vapor in the flow is used as seed. The tunnel is supplied with continuous air flow at up to 45 psia and the flow is exhausted into the GRC laboratory-wide altitude exhaust system at pressures down to 0.3 psia.