WorldWideScience

Sample records for laue lens design

  1. Soft gamma-ray optics: new Laue lens design and performance estimates

    CERN Document Server

    Barriere, N; Abrosimov, N; Von Ballmoos, P; Bastie, P; Courtois, P; Jentschel, M; Knödlseder, J; Rousselle, J; Ubertini, P

    2009-01-01

    Laue lenses are an emerging technology based on diffraction in crystals that allows the concentration of soft gamma rays. This kind of optics that works in the 100 keV - 1.5 MeV band can be used to realize an high-sensitivity and high-angular resolution telescope (in a narrow field of view). This paper reviews the recent progresses that have been done in the development of efficient crystals, in the design study and in the modelisation of the answer of Laue lenses. Through the example of a new concept of 20 m focal length lens focusing in the 100 keV - 600 keV band, the performance of a telescope based on a Laue lens is presented. This lens uses the most efficient mosaic crystals in each sub-energy range in order to yield the maximum reflectivity. Imaging capabilities are investigated and shows promising results.

  2. A focal plane detector design for a wide-band Laue-lens telescope

    DEFF Research Database (Denmark)

    Caroli, E.; Auricchio, N.; Amati, L.

    2005-01-01

    , and the detection of nuclear and annihilation lines. Recently the development of high energy Laue lenses with broad energy bandpasses from 60 to 600 keV have been proposed for a Hard X ray focusing Telescope (HAXTEL) in order to study the X-ray continuum of celestial sources. The required focal plane detector...

  3. A focal plane detector design for a wide-band Laue-lens telescope

    CERN Document Server

    Caroli, E; Amati, L; Bezsmolnyy, Y; Budtz-Jorgensen, C; Silva, R M C; Frontera, F; Pisa, A; Del Sordo, S; Stephen, J B; Ventura, G; Caroli, Ezio; Auricchio, Natalia; Amati, Lorenzo; Bezsmolnyy, Yuriy; Budtz-Jorgensen, Carl; Silva, Rui M. Curado da; Frontera, Filippo; Pisa, Alessandro; Sordo, Stefano Del; Stephen, John B.; Ventura, Giulio

    2006-01-01

    The energy range above 60 keV is important for the study of many open problems in high energy astrophysics such as the role of Inverse Compton with respect to synchrotron or thermal processes in GRBs, non thermal mechanisms in SNR, the study of the high energy cut-offs in AGN spectra, and the detection of nuclear and annihilation lines. Recently the development of high energy Laue lenses with broad energy bandpasses from 60 to 600 keV have been proposed for a Hard X ray focusing Telescope (HAXTEL) in order to study the X-ray continuum of celestial sources. The required focal plane detector should have high detection efficiency over the entire operative range, a spatial resolution of about 1 mm, an energy resolution of a few keV at 500 keV and a sensitivity to linear polarization. We describe a possible configuration of the focal plane detector based on several CdTe/CZT pixelated layers stacked together to achieve the required detection efficiency at high energy. Each layer can operate both as a separate posit...

  4. Simulation of a Laue lens with bent Ge(111) crystals

    CERN Document Server

    Valsan, Vineeth; Frontera, Filippo; Liccardo, Vincenzo; Caroli, Ezio; Stephen, John B

    2015-01-01

    In the context of Laue project for focusing hard X-/ soft gamma-rays, an entire Laue lens, using bent Ge(111) crystal tiles, with 40 meters curvature radius, is simulated with a focal length of 20 meters. The focusing energy band is between 80 keV and 600 keV. The distortion of the output image of the lens on the focal plane due to the effect of crystal tile misalignment as well as the radial distortion arising from the curvature of the crystal is discussed in detail. Expected detection efficiency and instrument background is also estimated. Finally the sensitivity of the Laue lens is calculated. A quantitative analysis of the results of these simulation is also presented.

  5. An "ESA-affordable" Laue-lens

    DEFF Research Database (Denmark)

    Lund, Niels

    2005-01-01

    With ESA's INTEGRAL mission gamma-ray astronomy has advanced to the point where major scientific advances must be expected from detailed studies of the many new point sources. The interest in developing focusing telescopes operating in the soft gamma-ray regime up to 1 MeV is therefore mounting...... constraints of a specific medium size launch vehicle. The introduction of the lens mass as a primary design driver has some surprising effects for the choice of material for the crystals and new tradeoff considerations are introduced....

  6. Multilayer Laue Lens Growth at NSLS-II

    Energy Technology Data Exchange (ETDEWEB)

    Conley R.; Bouet, N.; Lauer, K.; Carlucci-Dayton, M.; Biancarosa, J.; Boas, L.; Drannbauer, J.; Feraca, J.; Rosenbaum, L.

    2012-08-15

    The new NSLS-II deposition laboratory has been commissioned to include a variety of thin-film characterization equipment and a next-generation deposition system. The primary goal for this effort is R&D on the multilayer Laue lens (MLL), which is a new type of x-ray optic with the potential for an unprecedented level of x-ray nano-focusing. This unique deposition system contains many design features in order to facilitate growth of combined depth-graded and laterally graded multilayers with precise thickness control over many thousands of layers, providing total film growth in one run of up to 100 {micro}m thick or greater. A precision in-vacuum linear motor servo system raster scans a substrate over an array of magnetrons with shaped apertures at well-defined velocities to affect a multilayer coating. The design, commissioning, and performance metrics of the NSLS-II deposition system will be discussed. Latest growth results of both MLL and reflective multilayers in this machine will be presented.

  7. Rapid and Accurate Assembly Method for a New Laue Lens Prototype

    DEFF Research Database (Denmark)

    Wade, Colin; Barriere, Nicolas; Hanlon, Lorraine

    2015-01-01

    The Laue lens is a technology for gamma-ray astrophysics whereby gamma-rays of particular energies can be focused by a suitable arrangement of crystals. The Laue lens assembly station at UC Berkeley was used to build a technological demonstrator addressing the key issues of crystal mounting speed...

  8. Submicron focusing of XUV radiation from a laser plasma source using a multilayer Laue lens

    Science.gov (United States)

    Reese, M.; Schäfer, B.; Großmann, P.; Bayer, A.; Mann, K.; Liese, T.; Krebs, H. U.

    2011-01-01

    The focusing properties of a one-dimensional multilayer Laue lens (MLL) were investigated using monochromatic soft X-ray radiation from a table-top, laser-produced plasma source. The MLL was fabricated by a focused ion beam (FIB) structuring of pulsed laser deposited ZrO2/Ti multilayers. This novel method offers the potential to overcome limitations encountered in electron lithographic processes. Utilizing this multilayer Laue lens, a line focus of XUV radiation from a laser-induced plasma in a nitrogen gas puff target could be generated. The evaluated focal length is close to the designed value of 220 μm for the measurement wavelength of 2.88 nm. Divergence angle and beam waist diameter are measured by a moving knife edge and a far-field experiment, determining all relevant second-order moments based beam parameters. The waist diameter has been found to be approximately 370 nm (FWHM).

  9. Hard X / soft gamma ray polarimetry using a Laue lens

    CERN Document Server

    Barrière, Nicolas M; Ubertini, Pietro

    2011-01-01

    Hard X / soft gamma-ray polarimetric analysis can be performed efficiently by the study of Compton scattering anisotropy in a detector composed of fine pixels. But in the energy range above 100 keV where sources flux are extremely weak and instrumental background very strong, such delicate measurement is actually very difficult to perform. Laue lens is an emerging technology based on diffraction in crystals allowing the concentration of soft gamma rays. This kind of optics can be applied to realize an efficient high-sensitivity and high-angular resolution telescope, at the cost of a field of view reduced to a few arcmin though. A 20 m focal length telescope concept focusing in the 100 keV - 600 keV energy range is taken as example here to show that recent progresses in the domain of high-reflectivity crystals can lead to very appealing performance. The Laue lens being fully transparent to polarization, this kind of telescope would be well suited to perform polarimetric studies since the ideal focal plan is a ...

  10. R&D progress on second-generation crystals for Laue lens applications

    CERN Document Server

    Barrière, N; Bastie, P; Courtois, P; Abrosimov, N V; Andersen, K; Buslaps, T; Camus, T; Halloin, H; Jentschel, M; Knödlseder, J; Roudil, G; Serre, D; Skinner, G

    2007-01-01

    The concept of a gamma-ray telescope based on a Laue lens offers the possibility to increase the sensitivity by more than an order of magnitude with respect to existing instruments. Laue lenses have been developed by our collaboration for several years : the main achievement of this R&D program was the CLAIRE lens prototype. Since then, the endeavour has been oriented towards the development of efficient diffracting elements (crystal slabs), the aim being to step from a technological Laue lens to a scientifically exploitable lens. The latest mission concept featuring a gamma-ray lens is the European Gamma-Ray Imager (GRI) which intends to make use of the Laue lens to cover energies from 200 keV to 1300 keV. Investigations of two promising materials, low mosaicity copper and gradient concentration silicon-germanium are presented in this paper. The measurements have been performed during three runs on beamline ID15A of the European Synchrotron Radiation Facility, and on the GAMS 4 instrument of the Institut...

  11. One dimensional focusing with high numerical aperture multilayer Laue lens

    Energy Technology Data Exchange (ETDEWEB)

    Bajt, Saša, E-mail: sasa.bajt@desy.de; Prasciolu, Mauro [Photon Science, DESY, Notkestrasse 85, 22607 Hamburg (Germany); Morgan, Andrew J. [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg (Germany); Chapman, Henry N. [Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg (Germany); Dept. of Physics, University of Hamburg, Luruper Chaussee 149, 22607 Hamburg (Germany); Centre for Ultrafast Imaging, Luruper Chaussee 149, 22607 Hamburg (Germany); Krzywinski, Jacek [SLAC, 2575 Sand Hill Rd., Menlo Park, CA 94025 (United States); Andrejczuk, Andrzej [Faculty of Physics, University of Bialystok, K. Ciolkowskiego 1L, 15-245, Bialystok (Poland)

    2016-01-28

    Multilayer Laue lenses (MLLs) capitalize on the developments in multilayer deposition technologies for fabricating reflective coatings, specifically undertaken for EUV lithography, where layer thicknesses of several nanometers can be achieved. MLLs are deposited layer by layer, with their thicknesses following the zone plate law, and then pieces are sliced and extracted for use in focusing. Rays are reflected in the Laue geometry. The efficiency of a MLL can be very high, and is maximized by making the slice equal to about a half Pendellosung period so that most energy is transferred from the undiffracted to the diffracted beam, and by ensuring that the Bragg condition is met at each point in the zone plate. This latter condition requires that the layers are tilted to the beam by an amount that varies with layer position; e.g. for focusing a collimated beam, the layers should be normal to a cylinder of radius of twice the focal length. We have fabricated such tilted-zone MLLs and find that they exhibit improved efficiency across their entire pupil as compared with parallel-zone MLLs. This leads to a higher effective NA of the optic and hence higher resolution.

  12. A positron annihilation radiation telescope using Laue diffraction in a crystal lens

    Energy Technology Data Exchange (ETDEWEB)

    Smither, R.K. (Argonne National Lab., IL (United States)); von Ballmoos, P. (Toulouse-3 Univ., 31 (France). Centre d' Etude Spatiale des Rayonnements)

    1993-03-01

    We present a new type of gamma-ray telescope featuring a Laue diffraction lens, a detector module with a 3-by-3 germanium array, and a balloon gondola stabilized to 5 arc sec pointing accuracy. The instrument's lens is designed to collect 511 keV photons on its 150 CM[sup 2] effective area and focus them onto a small detector having only [approx]14 CM[sup 3] of equivalent volume for background noise. As a result, this telescope overcomes the mass-sensitivity impasse of present detectors in which the collection areas are identical to the detection area. The sensitivity of our instrument is anticipated to be 3 [times] 10[sup [minus]5] ph cm[sup [minus]2] S[sup [minus]1] at 511 key with an angular resolution of 15 arc sec and an energy resolution of 2 keV. These features will allow the resolve of a possible energetically narrow 511 keV positron annihilation line both energy-wise and spatially within a Galactic Center microquasar'' as 1El740.7-2942 or GRS1758-258. In addition to the galactic microquasars,'' other prime objectives include Cyg X-1, X-ray binaries, pulsars, and AGNS.

  13. A positron annihilation radiation telescope using Laue diffraction in a crystal lens

    Energy Technology Data Exchange (ETDEWEB)

    Smither, R.K. [Argonne National Lab., IL (United States); von Ballmoos, P. [Toulouse-3 Univ., 31 (France). Centre d`Etude Spatiale des Rayonnements

    1993-03-01

    We present a new type of gamma-ray telescope featuring a Laue diffraction lens, a detector module with a 3-by-3 germanium array, and a balloon gondola stabilized to 5 arc sec pointing accuracy. The instrument`s lens is designed to collect 511 keV photons on its 150 CM{sup 2} effective area and focus them onto a small detector having only {approx}14 CM{sup 3} of equivalent volume for background noise. As a result, this telescope overcomes the mass-sensitivity impasse of present detectors in which the collection areas are identical to the detection area. The sensitivity of our instrument is anticipated to be 3 {times} 10{sup {minus}5} ph cm{sup {minus}2} S{sup {minus}1} at 511 key with an angular resolution of 15 arc sec and an energy resolution of 2 keV. These features will allow the resolve of a possible energetically narrow 511 keV positron annihilation line both energy-wise and spatially within a Galactic Center ``microquasar`` as 1El740.7-2942 or GRS1758-258. In addition to the galactic ``microquasars,`` other prime objectives include Cyg X-1, X-ray binaries, pulsars, and AGNS.

  14. Developing a method for soft gamma-ray Laue lens assembly and calibration

    CERN Document Server

    Barrière, Nicolas M; Boggs, Steven E; Lowell, Alexander; Wade, Colin; Baugh, Max; von Ballmoos, Peter; Abrosimov, Nikolay V; Hanlon, Lorraine

    2013-01-01

    Laue lenses constitute a promising option for concentrating soft gamma rays with a large collection area and reasonable focal lengths. In astronomy they could lead to increased telescope sensitivity by one to two orders of magnitude, in particular for faint nuclear gamma-ray lines, but also for continua like hard X-ray tails from a variety of compact objects. Other fields like Homeland security and nuclear medicine share the same need for more sensitive gamma-ray detection systems and could find applications for gamma-ray focusing optics. There are two primary challenges for developing Laue lenses: the search for high-reflectivity and reproducible crystals, and the development of a method to accurately orient and fix the thousands of crystals constituting a lens. In this paper we focus on the second topic. We used our dedicated X-ray beamline and Laue lens assembly station to build a breadboard lens made of 15 crystals. This allowed us to test our tools and methods, as well as our simulation code and calibrat...

  15. Unveiling Physical Processes in Type Ia Supernovae with a Laue Lens Telescope

    Science.gov (United States)

    Barriere, Nicolas; Boggs, S. E.; Tomsick, J. A.

    2010-03-01

    Despite their use as standard candles in cosmological studies, many fundamental aspects of Type Ia supernovae (SNIa) remain uncertain, including the progenitor systems, the explosion trigger and the detailed nuclear burning physics. The most popular model involves an accreting CO white dwarf undergoing a thermonuclear runaway, converting a substantial fraction of the stellar mass to 56Ni. The radioactive decay chain 56Ni -> 56Co -> 56Fe powers both the SNIa optical light curve and produces several gamma-ray lines, including bright lines at 158 keV and 847 keV. Observations of the spectrum and light curve of any of these lines would be extremely valuable in constraining and discriminating between the currently competing models of SNIa. However, these lines are weak in flux and evolve relatively quickly by gamma-ray standards: to be able to study a handful SNIa per year, the required sensitivity is about 10-6 ph/cm2/s at 847 keV and 10-7 ph/s/cm2 at 158 keV for 3% broadened lines, and these levels must be achieved in 105 s. A Laue lens telescope offers a novel and powerful method of achieving these extremely challenging requirements. In this paper, we briefly introduce the Laue lens principle and state-of-the-art technologies, and we demonstrate how a space-borne telescope based on a Laue lens focusing on a Compton camera could bring about the long-awaited observational clues leading to a better understanding of SNIa physics.

  16. Development of a 3D CZT detector prototype for Laue Lens telescope

    OpenAIRE

    Caroli, Ezio; Auricchio, Natalia; Del Sordo, Stefano; Abbene, Leonardo; Budtz-JøRgensen, Carl; Casini, Fabio; Curado da Silva, Rui M.; Kuvvetli, Irfan; Milano, Luciano; Natalucci, Lorenzo; Quadrini, Egidio M.; Stephen, John B.; Ubertini, Pietro; Zanichelli, Massimiliano; Zappettini, Andrea

    2010-01-01

    We report on the development of a 3D position sensitive prototype suitable as focal plane detector for Laue lens telescope. The basic sensitive unit is a drift strip detector based on a CZT crystal, (~19×8 mm2 area, 2.4 mm thick), irradiated transversally to the electric field direction. The anode side is segmented in 64 strips, that divide the crystal in 8 independent sensor (pixel), each composed by one collecting strip and 7 (one in common) adjacent drift strips. The drift strips are biase...

  17. Laue lens for radiotherapy applications through a focused hard x-ray beam: a feasibility study on requirements and tolerances

    Science.gov (United States)

    Camattari, Riccardo

    2017-09-01

    Focusing a hard x-ray beam would represent an innovative technique for tumour treatment, since such a beam may deliver a dose to a tumour located at a given depth under the skin, sparing the surrounding healthy cells. A detailed study of a focusing system for hard x-ray aimed at radiotherapy is presented here. Such a focusing system, named Laue lens, exploits x-ray diffraction and consists of a series of crystals disposed as concentric rings capable of concentrating a flux of x-rays towards a focusing point. A feasibility study regarding the positioning tolerances of the crystalline optical elements has been carried out. It is shown that a Laue lens can effectively be used in the context of radiotherapy for tumour treatments provided that the mounting errors are below certain values, which are reachable in the modern micromechanics. An extended survey based on an analytical approach and on simulations is presented for precisely estimating all the contributions of each mounting error, analysing their effect on the focal spot of the Laue lens. Finally, a simulation for evaluating the released dose in a water phantom is shown.

  18. Development of a 3D CZT detector prototype for Laue Lens telescope

    Science.gov (United States)

    Caroli, Ezio; Auricchio, Natalia; Del Sordo, Stefano; Abbene, Leonardo; Budtz-Jørgensen, Carl; Casini, Fabio; Curado da Silva, Rui M.; Kuvvetlli, Irfan; Milano, Luciano; Natalucci, Lorenzo; Quadrini, Egidio M.; Stephen, John B.; Ubertini, Pietro; Zanichelli, Massimiliano; Zappettini, Andrea

    2010-07-01

    We report on the development of a 3D position sensitive prototype suitable as focal plane detector for Laue lens telescope. The basic sensitive unit is a drift strip detector based on a CZT crystal, (~19×8 mm2 area, 2.4 mm thick), irradiated transversally to the electric field direction. The anode side is segmented in 64 strips, that divide the crystal in 8 independent sensor (pixel), each composed by one collecting strip and 7 (one in common) adjacent drift strips. The drift strips are biased by a voltage divider, whereas the anode strips are held at ground. Furthermore, the cathode is divided in 4 horizontal strips for the reconstruction of the third interaction position coordinate. The 3D prototype will be made by packing 8 linear modules, each composed by one basic sensitive unit, bonded on a ceramic layer. The linear modules readout is provided by a custom front end electronics implementing a set of three RENA-3 for a total of 128 channels. The front-end electronics and the operating logics (in particular coincidence logics for polarisation measurements) are handled by a versatile and modular multi-parametric back end electronics developed using FPGA technology.

  19. Optical laue diffraction on photonic structures designed by laser lithography

    Science.gov (United States)

    Samusev, K. B.; Rybin, M. V.; Lukashenko, S. Yu.; Limonov, M. F.

    2016-06-01

    Two-dimensional photonic crystals with square symmetry C 4v were obtained using the laser lithography method. The structure of these samples was studied by scanning electron microscopy. Optical Laue diffraction for monochromatic light was studied experimentally depending on the incidence angle of laser beam and lattice constant. Interpretation of the observed diffraction patterns is given in the framework of the Laue diffraction mechanism for an one-dimensional chain of scattering elements. Red thresholds for different diffraction orders were determined experimentally and theoretically. The results of calculations are in an excellent agreement with experiment.

  20. Rapid and Accurate Assembly Method for a New Laue Lens Prototype

    DEFF Research Database (Denmark)

    Wade, Colin; Barriere, Nicolas; Hanlon, Lorraine;

    2015-01-01

    , crystal position and orientation accuracy, and crystal reflectivity. The new prototype is a lens segment containing a total of 48 5 x 5 mm2 crystals - 36 Iron and 12 Aluminium. The segment is composed of 8 partial rings, each of which is aligned to diffract an energy between 95 and 130 keV from a source...

  1. A CZT high efficiency detector with 3D spatial resolution for Laue lens applications

    DEFF Research Database (Denmark)

    Auricchio, N.; Basili, A.; Caroli, E.

    2010-01-01

    high performance focal plane detectors in order to exploit to the maximum the intrinsic capabilities of these new high energy telescopes. We describe the ongoing development of a three dimensional (3D) position sensitive device suitable as the basic unit of a high efficiency focal plane detector...... one collecting strip and 8 drift strips. The drift strips are biased by a voltage divider. The cathode is divided into 4 horizontal strips for the reconstruction of the third coordinate of the interaction. The final 3D prototype is made by packing 8 linear modules, each composed of one basic sensitive...... unit, bonded onto a supporting ceramic layer. The readout electronics implements the new RENA-3 Asics and the data handling system uses custom designed FPGA based electronics to provide both the ASIC operation and the acquisition logic....

  2. A course in lens design

    CERN Document Server

    Velzel, Chris

    2014-01-01

    A Course in Lens Design is an instruction in the design of image-forming optical systems. It teaches how a satisfactory design can be obtained in a straightforward way. Theory is limited to a minimum, and used to support the practical design work. The book introduces geometrical optics, optical instruments and aberrations. It gives a description of the process of lens design and of the strategies used in this process. Half of its content is devoted to the design of sixteen types of lenses, described in detail from beginning to end. This book is different from most other books on lens design because it stresses the importance of the initial phases of the design process: (paraxial) lay-out and (thin-lens) pre-design. The argument for this change of accent is that in these phases much information can be obtained about the properties of the lens to be designed. This information can be used in later phases of the design. This makes A Course in Lens Design a useful self-study book, and a suitable basis for an intro...

  3. Experimental and theoretical study of diffraction properties of various crystals for the realization of a soft gamma-ray Laue lens

    CERN Document Server

    Barriere, Nicolas; von Ballmoos, Peter; Abrosimov, Nikolai V; Courtois, Pierre; Bastie, Pierre; Camus, Thierry; Jentschel, Michael; Kurlov, Vladimir N; Natalucci, Lorenzo; Roudil, Gilles; Brejnholt, Nicolai Frisch; Serre, Denis

    2009-01-01

    Crystals are the elementary constituents of Laue lenses, an emerging technology which could allow the realization of a space borne telescope 10 to 100 times more sensitive than existing ones in the 100 keV - 1.5 MeV energy range. This study addresses the current endeavor to the development of efficient crystals for the realization of a Laue lens. In the theoretical part 35 candidate-crystals both pure and two-components are considered. Their peak reflectivity at 100 keV, 500 keV and 1 MeV is calculated assuming they are mosaic crystals. It results that a careful selection of crystals can allow a reflectivity above 30% over the whole energy range, and even reaching 40% in its lower part. Experimentally, we concentrated on three different materials (Si_{1-x}Ge_x with gradient of composition, mosaic Cu and Au) that have been measured both at ESRF and ILL using highly-monochromatic beams ranging from 300 keV up to 816 keV. The aim was to check their homogeneity, quality and angular spread (mosaicity). These cryst...

  4. Panoramic lens designed with transformation optics

    Science.gov (United States)

    Wang, Huaping; Deng, Yangyang; Zheng, Bin; Li, Rujiang; Jiang, Yuyu; Dehdashti, Shahram; Xu, Zhiwei; Chen, Hongsheng

    2017-01-01

    The panoramic lens is a special kind of lens, which is applied to observe full view. In this letter, we theoretically present a panoramic lens (PL) using transformation optics method. The lens is designed with inhomogeneous and anisotropic constitutive parameters, which has the ability to gather light from all directions and confine light within the visual angle of observer. Simulation results validate our theoretical design.

  5. Transferring Lens Prescriptions Between Lens-Design Programs

    Science.gov (United States)

    Stacy, John E.; Wooley, Laura; Carlin, Brian

    1989-01-01

    Optical Lens Prescription Data Formatter computer program enables user to transfer complicated lens prescriptions quickly and easily from one major optical-design program to another and back again. One can take advantage of inherent strength of either program. Programs are ACCOS V from Scientific Calculations, Inc., of Fishers, NY, and CODE V from Optical Research Associates of Pasadena, CA. VAX version written in FORTRAN.

  6. An inverse and analytic lens design method

    OpenAIRE

    Lu, Yang; Lakshminarayanan, Vasudevan

    2016-01-01

    Traditional lens design is a numerical and forward process based on ray tracing and aberration theory. This method has limitations because the initial configuration of the lens has to be specified and the aberrations of the lenses have to considered. This paper is an initial attempt to investigate an analytic and inverse lens design method, called Lagrange, to overcome these barriers. Lagrange method tries to build differential equations in terms of the system parameters and the system input ...

  7. The 2010 IODC lens design problem: the green lens

    Science.gov (United States)

    Juergens, Richard C.

    2010-08-01

    The lens design problem for the 2010 IODC is to design a 100 mm focal length lens in which every optical surface has the same radius of curvature, positive or negative, or is plano. The lens is used monochromatically at 532 nm and is made of only Schott N-BK7 glass. The goal of the problem is to maximize the product of the semi-field of view and the entrance pupil diameter while holding the distortion to within +/-5% and the RMS wavefront error to <= 0.07 wave within the field of view. There were 37 entries from eight different countries. Four different commercial lens design programs were used, along with two custom, in-house programs. The number of lens elements in the entries ranged from 3 to 64. The overall length of the lenses varied from 105 mm to 3.6 km. The winning entry had an entrance pupil diameter of 81.3 mm and a semi-field of view of 43.5° for a merit function product of 3537.

  8. Experimental and theoretical study of the diffraction properties of various crystals for the realization of a soft gamma-ray Laue lens

    DEFF Research Database (Denmark)

    Barriere, N.; Rousselle, J.; von Ballmoos, P.

    2009-01-01

    Crystals are the elementary constituents of Laue lenses, an emerging technology which could allow the realization of a space-borne telescope 10-100 times more sensitive than existing ones, in the 100 keV-1.5 MeV energy range. This paper addresses the development of efficient crystals for the real......Crystals are the elementary constituents of Laue lenses, an emerging technology which could allow the realization of a space-borne telescope 10-100 times more sensitive than existing ones, in the 100 keV-1.5 MeV energy range. This paper addresses the development of efficient crystals...

  9. Algorithm design of liquid lens inspection system

    Science.gov (United States)

    Hsieh, Lu-Lin; Wang, Chun-Chieh

    2008-08-01

    In mobile lens domain, the glass lens is often to be applied in high-resolution requirement situation; but the glass zoom lens needs to be collocated with movable machinery and voice-coil motor, which usually arises some space limits in minimum design. In high level molding component technology development, the appearance of liquid lens has become the focus of mobile phone and digital camera companies. The liquid lens sets with solid optical lens and driving circuit has replaced the original components. As a result, the volume requirement is decreased to merely 50% of the original design. Besides, with the high focus adjusting speed, low energy requirement, high durability, and low-cost manufacturing process, the liquid lens shows advantages in the competitive market. In the past, authors only need to inspect the scrape defect made by external force for the glass lens. As to the liquid lens, authors need to inspect the state of four different structural layers due to the different design and structure. In this paper, authors apply machine vision and digital image processing technology to administer inspections in the particular layer according to the needs of users. According to our experiment results, the algorithm proposed can automatically delete non-focus background, extract the region of interest, find out and analyze the defects efficiently in the particular layer. In the future, authors will combine the algorithm of the system with automatic-focus technology to implement the inside inspection based on the product inspective demands.

  10. Managing as designing with a positive lens

    NARCIS (Netherlands)

    Avital, M.; Boland, R.J.; Avital, M.; Boland, R.J.; Cooperrider, D.L.

    2007-01-01

    The role and potential contribution of a positive lens to the design of systems and organizations is the focus of this essay. The positive lens refers to an emerging perspective in the social sciences that emphasizes a positive stance toward our capacity to construct better organizations and technol

  11. Lens Design Using Group Indices of Refraction

    Science.gov (United States)

    Vaughan, A. H.

    1995-01-01

    An approach to lens design is described in which the ratio of the group velocity to the speed of light (the group index) in glass is used, in conjunction with the more familiar phase index of refraction, to control certain chromatic properties of a system of thin lenses in contact. The first-order design of thin-lens systems is illustrated by examples incorporating the methods described.

  12. Photon nanojet lens: design, fabrication and characterization

    Science.gov (United States)

    Xu, Chen; Zhang, Sichao; Shao, Jinhai; Lu, Bing-Rui; Mehfuz, Reyad; Drakeley, Stacey; Huang, Fumin; Chen, Yifang

    2016-04-01

    In this paper, a novel nanolens with super resolution, based on the photon nanojet effect through dielectric nanostructures in visible wavelengths, is proposed. The nanolens is made from plastic SU-8, consisting of parallel semi-cylinders in an array. This paper focuses on the lens designed by numerical simulation with the finite-difference time domain method and nanofabrication of the lens by grayscale electron beam lithography combined with a casting/bonding/lift-off transfer process. Monte Carlo simulation for injected charge distribution and development modeling was applied to define the resultant 3D profile in PMMA as the template for the lens shape. After the casting/bonding/lift-off process, the fabricated nanolens in SU-8 has the desired lens shape, very close to that of PMMA, indicating that the pattern transfer process developed in this work can be reliably applied not only for the fabrication of the lens but also for other 3D nanopatterns in general. The light distribution through the lens near its surface was initially characterized by a scanning near-field optical microscope, showing a well defined focusing image of designed grating lines. Such focusing function supports the great prospects of developing a novel nanolithography based on the photon nanojet effect.

  13. Application of optical polymers in lens design

    Science.gov (United States)

    Sultanova, Nina; Kasarova, Stefka; Nikolov, Ivan

    2016-03-01

    Optical, some thermal and elastic properties of optical polymers which are of importance in lens design are considered. Results are based on precise measurement of refraction of materials. Ultrasonic investigation of elastic moduli is carried out. Comparison to properties of Schott glasses is accomplished. Examples on the design of all-plastic and hybrid glass-plastic systems are presented.

  14. An inverse and analytic lens design method

    CERN Document Server

    Lu, Yang

    2016-01-01

    Traditional lens design is a numerical and forward process based on ray tracing and aberration theory. This method has limitations because the initial configuration of the lens has to be specified and the aberrations of the lenses have to considered. This paper is an initial attempt to investigate an analytic and inverse lens design method, called Lagrange, to overcome these barriers. Lagrange method tries to build differential equations in terms of the system parameters and the system input and output (object and image). The generalized Snell's law in three dimensional space and the normal of a surface in fundamental differential geometry are applied. Based on the Lagrange method equations for a single surface system are derived which can perfectly image a point object.

  15. A correlation of thin lens approximation to thick lens design by using context based method in optics education

    Science.gov (United States)

    Farsakoglu, O. F.; Inal Atik, Ipek; Kocabas, Hikmet

    2014-07-01

    The effect of Coddington factors on aberration functions has been analysed using thin lens approximation with optical glass parameters. The dependence of spherical aberration on Coddington shape factor for the various optical glasses in real lens design was discussed using exact ray tracing for the optics education and training purposes. Thin lens approximation and thick lens design are generally taught with only lecturing method. But, thick lens design is closely related to the real life. Hence, it is more appropriate to teach thin lens approximation and thick lens design with real-life context based approach. Context based teaching can be effective in solving problems in which the subject is very difficult and irrelevant. It also provides extensive evidence for optics education that students are generally unable to correctly apply the concepts of lens design to optical instruments currently used. Therefore, the outline of real-life context based thick lens design lessons were proposed and explained in detail considering thin lens approximation.

  16. Hemispherical Laue camera

    Science.gov (United States)

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  17. Preliminary of Optical Lens Design for Micro-Satellite

    Science.gov (United States)

    Rachim, Elvira; Mukhtar Tahir, Andi; Herawan, Agus

    2017-01-01

    The development of micro satellites for the last two decades is emerging rapidly as the need of satellite communication usage is increasing. Earth observation is one of the example of how satellites are on demand. Most observation satellites consist of sensors and imaging system on-board. One of the key element to have a good imaging system is a special optical lens system design. Such lens is designed specifically by calculating every parameter such as refractive, reflective indexes, type of surface, distance and many more. Manufactured lenses sometimes do not match the requirement of an imager system hence the special lens design is needed. This paper will first briefly describe the history of optic, theory related to lens system, then the design and the analysis of lens system for micro-satellites generally and LAPAN A4 particularly.

  18. Why are there so many system shapes in lens design?

    NARCIS (Netherlands)

    Bociort, F.

    2010-01-01

    The presence of many local minima in the merit function landscape is perhaps the most difficult challenge in lens design. We present a simplified mathematical model that illustrates why the number of local minima increases rapidly with each additional lens added to the imaging system. Comparisons wi

  19. A bent Laue-Laue monochromator for a synchrotron-based computed tomography system

    CERN Document Server

    Ren, B; Chapman, L D; Ivanov, I; Wu, X Y; Zhong, Z; Huang, X

    1999-01-01

    We designed and tested a two-crystal bent Laue-Laue monochromator for wide, fan-shaped synchrotron X-ray beams for the program multiple energy computed tomography (MECT) at the National Synchrotron Light Source (NSLS). MECT employs monochromatic X-ray beams from the NSLS's X17B superconducting wiggler beamline for computed tomography (CT) with an improved image quality. MECT uses a fixed horizontal fan-shaped beam with the subject's apparatus rotating around a vertical axis. The new monochromator uses two Czochralski-grown Si crystals, 0.7 and 1.4 mm thick, respectively, and with thick ribs on their upper and lower ends. The crystals are bent cylindrically, with the axis of the cylinder parallel to the fan beam, using 4-rod benders with two fixed rods and two movable ones. The bent-crystal feature of the monochromator resolved the difficulties we had had with the flat Laue-Laue design previously used in MECT, which included (a) inadequate beam intensity, (b) excessive fluctuations in beam intensity, and (c) i...

  20. Design and simulation of large field plate lithography lens

    Science.gov (United States)

    Deng, Chao; Xing, Tingwen; Lin, Wumei; Zhu, Xianchang

    2016-10-01

    Because industry demand for LED,LCD panel continues to increase, the high yield of micron-scale resolution lithography is increasingly prominent for manufacturers, which requires the field of lithography objective lens becomes larger. This paper designed a lithography lens with large field, whose effective image side field will reach to 132 × 132mm.Subsequently, the tolerance was analysed by simulation for the optical system. Finally, it is proved that the design meets the requirements of micron-scale resolution.

  1. Effects of Different Contact Lens Designs on Visual Quality Among the Soft Spherical Contact Lens Users

    Directory of Open Access Journals (Sweden)

    Mustafa Demir

    2013-10-01

    Full Text Available Purpose: To evaluate the effects of different lens designs on visual quality among soft spherical contact lens users. Material and Method: Forty eyes of twenty patients from our contact lens unit were included in this study. Refractive errors of the patients were between -0.50 and -6.0 diopters with 0.05. Total higher order aberration mean rms value was 0.29±0.10 µm without glasses, while it was 0.33±0.10 µm with Balafilcon A lenses and 0.31±0.10 µm with Senofilcon A lenses. Higher order aberration values measured after contact lens application did not show a significant difference for two contact lens designs (p>0.05. Discussion: High and low contrast sensitivity values were better with spectacles compared to contact lenses. We did not observe significant difference in higher order aberration values and visual quality between aspheric and spheric designed lenses. (Turk J Ophthalmol 2013; 43: 321-5

  2. Numerical implementation of generalized Coddington equations for ophthalmic lens design

    Science.gov (United States)

    Rojo, P.; Royo, S.; Ramírez, J.; Madariaga, I.

    2014-02-01

    A method for general implementation in any software platform of the generalized Coddington equations is presented, developed, and validated within a Matlab environment. The ophthalmic lens design strategy is presented thoroughly, and the basic concepts of generalized ray tracing are introduced. The methodology for ray tracing is shown to include two inter-related processes. Firstly, finite ray tracing is used to provide the main direction of propagation of the considered ray at the incidence point of interest. Afterwards, generalized ray tracing provides the principal curvatures of the local wavefront at that point, and its orientation after being refracted by the lens. The curvature values of the local wavefront are interpreted as the sagital and tangential powers of the lens at the point of interest. The proposed approach is validated using a double-check of the calculated lens performance in the spherical lens case: while finite ray tracing is validated using a commercial ray tracing software, generalized ray tracing is validated using a software application for ophthalmic lens design based on the classical version of Coddington equations. Equations of the complete tracing process are developed in detail for the case of generic astigmatic ophthalmic lenses as an example. Three-dimensional representation of the sagital and tangential powers of the ophthalmic lens at all directions of gaze then becomes possible, and results are presented for lenses with different geometries.

  3. The Influence of Different OK Lens Designs on Peripheral Refraction.

    Science.gov (United States)

    Kang, Pauline; Swarbrick, Helen

    2016-09-01

    To compare peripheral refraction changes along the horizontal and vertical meridians induced by three different orthokeratology (OK) lens designs: BE, Paragon CRT, and Contex lenses. Nineteen subjects (6M, 13F, mean age 28 ± 7 years) were initially fitted with BE OK lenses in both eyes which were worn overnight for 14 days. Central and peripheral refraction and corneal topography were measured at baseline and after 14 nights of lens wear. After a minimum 2-week washout period, one randomly selected eye was re-fitted with a Paragon CRT lens and the other eye with a Contex OK lens. Measurements were repeated before and after 14 nights of lens wear. The three different OK lenses caused significant changes in peripheral refraction along both the horizontal and vertical visual fields (VFs). BE and Paragon CRT lenses induced a significant hyperopic shift within the central ±20° along the horizontal VF and at all positions along the vertical meridian except at 30° in the superior VF. There were no significant differences in peripheral refraction changes induced between BE and Paragon CRT lenses. When comparing BE and Contex OK lens designs, BE caused greater hyperopic shifts at 10° and 30° in the temporal VF and at center, 10°, and 20° in the superior VF along the vertical meridian. Furthermore, BE lenses caused greater reduction in Flat and Steep K values compared to Contex OK. OK lenses induced significant changes in peripheral refraction along the horizontal and vertical meridians. Despite the clinically significant difference in central corneal flattening induced by BE and Contex OK lenses, relative peripheral refraction changes differed minimally between the three OK lens designs. If the peripheral retina influences refractive error development, these results suggest that myopia control effects are likely to be similar between different OK lens designs.

  4. Gravitational Lens: Deep Space Probe Design

    Science.gov (United States)

    2012-03-01

    List of Abbreviations Abbreviation Page FSM Focal Space Mission . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 CMB Cosmic Microwave...concert with the sun’s gravitational lens to image nearby solar systems and/or other pertinent astronomical objects, e.g. the Cosmic Microwave Background...CMB) radiation. 1.2 Thesis Objective In Deep Space Flight and Communications Claudio Maccone uses the mass, radius , mean density, and Schwarzschild

  5. Design of wide field and high resolution video lens

    Science.gov (United States)

    Xiao, Ze-xin; Zhan, Binzhou; Han, Haimei

    2009-11-01

    Online detecting is increasingly used in industrial process for the requirement of product quality improving. It is a trend that the "machine detecting" with "machine version + computer intelligence" as new method replaces traditional manual "eye observation". The essential of "machine detecting" is that image of object being collected with high resolution video lens on sensor panel of photoelectric (CCD ,CMOS) and detecting result being automatically gained by computer after the image saved and processed. "Machine detecting" is developing rapidly with the universal reception by enterprises because of its fine accurateness, high efficiency and the real time. Video lens is one of the important components of machine version system. Requirements of wide field and high resolution enlarged the complexity of video lens design. In this paper a design case used in visible light with field diameter Φ32mm, β=-0.25× and NA'=0.15. We give design parameters of the video lens which obtained with theoretically calculating and Oslo software optimization: MTF>0.3 in full field and 215lp/mm, distortion <0.05%.This lens has an excellent optic performance to match with 1.3 million pixels 1/2"CCD, and a high performance price ratio for being consist of only 7 single lens in the way of 5 units.

  6. IODC 1998 Lens Design Problem Revisited: A Strategy for Simplifying Glass Choices in an Apochromatic Design

    Energy Technology Data Exchange (ETDEWEB)

    Seppala, L G

    2000-09-15

    A glass-choice strategy, based on separately designing an achromatic lens before progressing to an apochromatic lens, simplified my approach to solving the International Optical Design Conference (IODC) 1998 lens design problem. The glasses that are needed to make the lens apochromatic are combined into triplet correctors with two ''buried'' surfaces. By applying this strategy, I reached successful solutions that used only six glasses--three glasses for the achromatic design and three additional glasses for the apochromatic design.

  7. Aspherical Lens Design Using Genetic Algorithm for Reducing Aberrations in Multifocal Artificial Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Chih-Ta Yen

    2015-09-01

    Full Text Available A complex intraocular lens (IOL design involving numerous uncertain variables is proposed. We integrated a genetic algorithm (GA with the commercial optical design software of (CODE V to design a multifocal IOL for the human eye. We mainly used an aspherical lens in the initial state to the crystalline type; therefore, we used the internal human eye model in the software. The proposed optimized algorithm employs a GA method for optimally simulating the focusing function of the human eye; in this method, the thickness and curvature of the anterior lens and the posterior part of the IOL were varied. A comparison of the proposed GA-designed IOLs and those designed using a CODE V built-in optimal algorithm for 550 degrees myopia and 175 degrees astigmatism conditions of the human eye for pupil size 6 mm showed that the proposed IOL design improved the spot size of root mean square (RMS, tangential coma (TCO and modulation transfer function (MTF at a spatial frequency of 30 with a pupil size of 6 mm by approximately 17%, 43% and 35%, respectively. However, the worst performance of spherical aberration (SA was lower than 46%, because the optical design involves a tradeoff between all aberrations. Compared with the traditional CODE V built-in optimal scheme, the proposed IOL design can efficiently improve the critical parameters, namely TCO, RMS, and MTF.

  8. Electrostatic afocal-zoom lens design using computer optimization technique

    Energy Technology Data Exchange (ETDEWEB)

    Sise, Omer, E-mail: omersise@gmail.com

    2014-12-15

    Highlights: • We describe the detailed design of a five-element electrostatic afocal-zoom lens. • The simplex optimization is used to optimize lens voltages. • The method can be applied to multi-element electrostatic lenses. - Abstract: Electron optics is the key to the successful operation of electron collision experiments where well designed electrostatic lenses are needed to drive electron beam before and after the collision. In this work, the imaging properties and aberration analysis of an electrostatic afocal-zoom lens design were investigated using a computer optimization technique. We have found a whole new range of voltage combinations that has gone unnoticed until now. A full range of voltage ratios and spherical and chromatic aberration coefficients were systematically analyzed with a range of magnifications between 0.3 and 3.2. The grid-shadow evaluation was also employed to show the effect of spherical aberration. The technique is found to be useful for searching the optimal configuration in a multi-element lens system.

  9. Hard x-ray broad band Laue lenses (80 - 600 keV): building methods and performances

    CERN Document Server

    Virgilli, E; Rosati, P; Liccardo, V; Squerzanti, S; Carassiti, V; Caroli, E; Auricchio, N; Stephen, J B

    2015-01-01

    We present the status of the laue project devoted to develop a technology for building a 20 meter long focal length Laue lens for hard x-/soft gamma-ray astronomy (80 - 600 keV). The Laue lens is composed of bent crystals of Gallium Arsenide (GaAs, 220) and Germanium (Ge, 111), and, for the first time, the focusing property of bent crystals has been exploited for this field of applications. We show the preliminary results concerning the adhesive employed to fix the crystal tiles over the lens support, the positioning accuracy obtained and possible further improvements. The Laue lens petal that will be completed in a few months has a pass band of 80 - 300 keV and is a fraction of an entire Laue lens capable of focusing X-rays up to 600 keV, possibly extendable down to 20 - 30 keV with suitable low absorption crystal materials and focal length. The final goal is to develop a focusing optics that can improve the sensitivity over current telescopes in this energy band by 2 orders of magnitude.

  10. Design of an ultraviolet projection lens by using a global search algorithm and computer optimization

    Science.gov (United States)

    Zoric, Nenad; Livshits, Irina; Dilworth, Don; Okishev, Sergey

    2017-02-01

    This paper describes a method for designing an ultraviolet (UV) projection lens for microlithography. Our approach for meeting this objective is to use a starting design automatically obtained by the DSEARCH feature in the SYNOPSYS™ lens design program. We describe the steps for getting a desired starting point for the projection lens and discuss optimization problems unique to this system, where the two parts of the projection lens are designed independently.

  11. A Computational Lens on Design Research

    Science.gov (United States)

    Hoyles, Celia; Noss, Richard

    2015-01-01

    In this commentary, we briefly review the collective effort of design researchers to weave theory with empirical results, in order to gain a better understanding of the processes of learning. We seek to respond to this challenging agenda by centring on the evolution of one sub-field: namely that which involves investigations within a…

  12. A Computational Lens on Design Research

    Science.gov (United States)

    Hoyles, Celia; Noss, Richard

    2015-01-01

    In this commentary, we briefly review the collective effort of design researchers to weave theory with empirical results, in order to gain a better understanding of the processes of learning. We seek to respond to this challenging agenda by centring on the evolution of one sub-field: namely that which involves investigations within a…

  13. Numerical implementation of generalized Coddington equations for ophthalmic lens design

    OpenAIRE

    Rojo Badenas, Pilar; Royo Royo, Santiago; RAMÍREZ,JORGE; Madariaga, Inés

    2014-01-01

    A method for general implementation in any software platform of the generalized Coddington equations is presented, developed, and validated within a Matlab environment. The ophthalmic lens design strategy is presented thoroughly, and the basic concepts of generalized ray tracing are introduced. The methodology for ray tracing is shown to include two inter-related processes. Firstly, finite ray tracing is used to provide the main direction of propagation of the considered ray at the incidence ...

  14. A design study of a magnifying magnetic lens for proton radiography

    Institute of Scientific and Technical Information of China (English)

    YANG Guo-Jun; ZHANG Zhuo; WEI Tao; HE Xiao-Zhong; LONG Ji-Dong; SHI Jin-Shui; ZHANG Kai-Zhi

    2012-01-01

    Magnifying magnetic lenses can be used in high-energy proton microscopes.The -I lens suggested by Zumbro is analyzed in this paper,and a new type of magnetic lens called a lengthened lens is introduced.Theoretical analysis shows that the lengthened lens can form a magnifying lens,and at the same time the main advantages of a Zumbro lens are inherited.Using the My-BOC beam dynamics code,an example of the design is shown.The results show that the method of designing magnifying magnetic lenses is effective.

  15. Superiority of zoom lens coupling in designing a novel X-ray image detector

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We design a novel X-ray image detector by lens coupling a Gd2O2S:Tb intensifying screen with a high performance low-light-level (L3,which often means luminescence less than 10-3 Lux) image intensifier.Different coupling effects on imaging performance between zoom lens and fix-focus lens are analyzed theoretically.In experiment,for designing a detector of 15-inch visual field,the system coupled by zoom lens is of 12.25-1p/cm resolution,while the one with fix-focus lens is 10 lp/cm.The superiority of zoom lens is validated.It is concluded that zoom lens preserves the image information better than fix-focus lens and improves the imaging system's performance in this design,which is referential to the design of other optical imaging systems.

  16. Design and analysis of an adaptive lens that mimics the performance of the crystalline lens in the human eye

    Science.gov (United States)

    Santiago-Alvarado, Agustin; Cruz-Félix, Angel S.; Iturbide-Jiménez, F.; Martínez-López, M.; Ramírez-Como, M.; Armengol-Cruz, V.; Vásquez-Báez, I.

    2014-09-01

    Tunable lenses are optical systems that have attracted much attention due to their potential applications in such areas like ophthalmology, machine vision, microscopy and laser processing. In recent years we have been working in the analysis and performance of a liquid-filled variable focal length lens, this is a lens that can modify its focal length by changing the amount of water within it. Nowadays we extend our study to a particular adaptive lens known as solid elastic lens (SEL) that it is formed by an elastic main body made of Polydimethylsiloxane (PDMS Sylgard 184). In this work, we present the design, simulation and analysis of an adaptive solid elastic lens that in principle imitates the accommodation process of the crystalline lens in the human eye. For this work, we have adopted the parameters of the schematic eye model developed in 1985 by Navarro et al.; this model represents the anatomy of the eye as close as possible to reality by predicting an acceptable and accurate quantity of spherical and chromatic aberrations without any shape fitting. An opto-mechanical analysis of the accommodation process of the adaptive lens is presented, by simulating a certain amount of radial force applied onto the SEL using the finite element method with the commercial software SolidWorks®. We also present ray-trace diagrams of the simulated compression process of the adaptive lens using the commercial software OSLO®.

  17. Concept design and simulation of a concentration lens with uniform square irradiance

    Science.gov (United States)

    Li, Dianhong; Xuan, Yimin

    2017-10-01

    A planar concentration lens comprised of square and rectangular lenses for solar concentration application is presented. The design of the concentration lens was based on the concept of Fresnel lens and the layout of the square light spot was proposed to match the receiving area. The uniformity of the light spot was determined by the structure of the concentration lens, which has different structures for different design wavelengths. The uniformity of the light spot and concentration ratio of the concentration lens were simulated. The numerical results indicate that the concentration ratio and uniformity of the light spot decrease with the increment of the wavelength. In order to improve the performance of the concentration lens, a novel hybrid wavelength structures was designed. The analysis results reveal that both the spot uniformity and concentration ratio of such a novel concentration lens were insensitive to the wavelengths variation. In addition, the angular tolerance of the concentration lens was discussed for different incident angles.

  18. Progressive addition lens design by optimizing NURBS surface

    Science.gov (United States)

    Liu, Yen-Liang; Hsu, Wei-Yao; Cheng, Yuan-Chieh; Su, Guo-Dung

    2011-10-01

    Progressive addition lenses (PAL) are used to compensate presbyopia, which is induced by losing accommodation of elder eyes. These eyes need different optical power provided by eye glasses while watching objects at different distance. A smaller optical power is required in further distance and a larger one in nearer zone. A progressive addition lens can provides different power requirements in one piece of lens. This paper introduces a whole process of PAL production, from design, fabrication, to measurement. The PAL is designed by optimizing NURBS surface. Parameters of merit function are adjusted to design lenses with different specifications. The simulation results confirm that the power distributes as expected and cylinders are controlled under an acceptable level. Besides, sample lenses have been fabricated and measured. We apply precise-machining to produce the molds for plastic injection. Then, the samples are produced by injecting polycorbonate to the molds. Finally, Ultra Accuracy 3D Profilemeter is used to measure the sample PALs. Practical examinations shows that our designs are achievable and feasible in practice use.

  19. Preliminary Design Study of the Hollow Electron Lens for LHC

    CERN Document Server

    Perini, Diego; CERN. Geneva. ATS Department

    2017-01-01

    A Hollow Electron Lens (HEL) has been proposed in order to improve performance of halo control and collimation in the Large Hadron Collider in view of its High Luminosity upgrade (HL-LHC). The concept is based on a beam of electrons that travels around the protons for a few meters. The electron beam is produced by a cathode and then guided by a strong magnetic field generated by a set of superconducting solenoids. The first step of the design is the definition of the magnetic fields that drive the electron trajectories. The estimation of such trajectories by means of a dedicated MATLAB® tool is presented. The influence of the main geometrical and electrical parameters are analysed and discussed. Then, the main mechanical design choices for the solenoids, cryostats gun and collector are described. The aim of this paper is to provide an overview of the preliminary design of the Electron Lens for LHC. The methods used in this study also serve as examples for future mechanical and integration designs of similar ...

  20. Design of a Test Bench for Intraocular Lens Optical Characterization

    Science.gov (United States)

    Alba-Bueno, Francisco; Vega, Fidel; Millán, María S.

    2011-01-01

    The crystalline lens is the responsible for focusing at different distances (accommodation) in the human eye. This organ grows throughout life increasing in size and rigidity. Moreover, due this growth it loses transparency through life, and becomes gradually opacified causing what is known as cataracts. Cataract is the most common cause of visual loss in the world. At present, this visual loss is recoverable by surgery in which the opacified lens is destroyed (phacoemulsification) and replaced by the implantation of an intraocular lens (IOL). If the IOL implanted is mono-focal the patient loses its natural capacity of accommodation, and as a consequence they would depend on an external optic correction to focus at different distances. In order to avoid this dependency, multifocal IOLs designs have been developed. The multi-focality can be achieved by using either, a refractive surface with different radii of curvature (refractive IOLs) or incorporating a diffractive surface (diffractive IOLs). To analyze the optical quality of IOLs it is necessary to test them in an optical bench that agrees with the ISO119679-2 1999 standard (Ophthalmic implants. Intraocular lenses. Part 2. Optical Properties and Test Methods). In addition to analyze the IOLs according to the ISO standard, we have designed an optical bench that allows us to simulate the conditions of a real human eye. To do that, we will use artificial corneas with different amounts of optical aberrations and several illumination sources with different spectral distributions. Moreover, the design of the test bench includes the possibility of testing the IOLs under off-axis conditions as well as in the presence of decentration and/or tilt. Finally, the optical imaging quality of the IOLs is assessed by using common metrics like the Modulation Transfer Function (MTF), the Point Spread Function (PSF) and/or the Strehl ratio (SR), or via registration of the IOL's wavefront with a Hartmann-Shack sensor and its

  1. Design of a Test Bench for Intraocular Lens Optical Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Alba-Bueno, Francisco; Vega, Fidel; Millan, Maria S, E-mail: francisco.alba-bueno@upc.edu, E-mail: fvega@oo.upc.edu, E-mail: millan@oo.upc.edu [Departamento de Optica y Optometria, Universidad Politecnica de Cataluna, C/ Violinista Vellsola 37, 08222 Terrassa (Spain)

    2011-01-01

    The crystalline lens is the responsible for focusing at different distances (accommodation) in the human eye. This organ grows throughout life increasing in size and rigidity. Moreover, due this growth it loses transparency through life, and becomes gradually opacified causing what is known as cataracts. Cataract is the most common cause of visual loss in the world. At present, this visual loss is recoverable by surgery in which the opacified lens is destroyed (phacoemulsification) and replaced by the implantation of an intraocular lens (IOL). If the IOL implanted is mono-focal the patient loses its natural capacity of accommodation, and as a consequence they would depend on an external optic correction to focus at different distances. In order to avoid this dependency, multifocal IOLs designs have been developed. The multi-focality can be achieved by using either, a refractive surface with different radii of curvature (refractive IOLs) or incorporating a diffractive surface (diffractive IOLs). To analyze the optical quality of IOLs it is necessary to test them in an optical bench that agrees with the ISO119679-2 1999 standard (Ophthalmic implants. Intraocular lenses. Part 2. Optical Properties and Test Methods). In addition to analyze the IOLs according to the ISO standard, we have designed an optical bench that allows us to simulate the conditions of a real human eye. To do that, we will use artificial corneas with different amounts of optical aberrations and several illumination sources with different spectral distributions. Moreover, the design of the test bench includes the possibility of testing the IOLs under off-axis conditions as well as in the presence of decentration and/or tilt. Finally, the optical imaging quality of the IOLs is assessed by using common metrics like the Modulation Transfer Function (MTF), the Point Spread Function (PSF) and/or the Strehl ratio (SR), or via registration of the IOL's wavefront with a Hartmann-Shack sensor and its

  2. Designated Communities”: Through the Lens of the Web

    Directory of Open Access Journals (Sweden)

    Yunhyong Kim

    2015-02-01

    Full Text Available The notion of a “designated community” has always been a rather elusive concept across the digital curation landscape. This paper is an effort to revisit the concept to stir up new discussions in the area. More specifically, this study offers a perspective on designated communities through the lens of the web, powered by developments in the last ten years in social media. The research presents a multi-faceted analysis of communities based on HTML content from online web pages to propose heuristics for defining designated communities based on the technology they adopt, properties of knowledge organisation, and how they link to each other. This impacts the building of quantifiable models of designated communities, estimating curation risks associated to the community and further, refining approaches to preservation strategies that meet the needs of the community.

  3. Focusing effect of bent GaAs crystals for gamma-ray Laue lenses: Monte Carlo and experimental results

    CERN Document Server

    Virgilli, E; Rosati, P; Bonnini, E; Buffagni, E; Ferrari, C; Stephen, J B; Caroli, E; Auricchio, N; Basili, A; Silvestri, S

    2015-01-01

    We report on results of observation of the focusing effect from the planes (220) of Gallium Arsenide (GaAs) crystals. We have compared the experimental results with the simulations of the focusing capability of GaAs tiles through a developed Monte Carlo. The GaAs tiles were bent using a lapping process developed at the cnr/imem - Parma (Italy) in the framework of the laue project, funded by ASI, dedicated to build a broad band Laue lens prototype for astrophysical applications in the hard X-/soft gamma-ray energy range (80-600 keV). We present and discuss the results obtained from their characterization, mainly in terms of focusing capability. Bent crystals will significantly increase the signal to noise ratio of a telescope based on a Laue lens, consequently leading to an unprecedented enhancement of sensitivity with respect to the present non focusing instrumentation.

  4. An Ultrasonic Lens Design Based on Prefractal Structures

    OpenAIRE

    Sergio Castiñeira-Ibáñez; Daniel Tarrazó-Serrano; Constanza Rubio; Pilar Candelas; Antonio Uris

    2016-01-01

    The improvement in focusing capabilities of a set of annular scatterers arranged in a fractal geometry is theoretically quantified in this work by means of the finite element method (FEM). Two different arrangements of rigid rings in water are used in the analysis. Thus, both a Fresnel ultrasonic lens and an arrangement of rigid rings based on Cantor prefractals are analyzed. Results show that the focusing capacity of the modified fractal lens is better than the Fresnel lens. This new lens is...

  5. Laue 2007: international workshop on advanced Laue diffraction in frontier science

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, S.I.; Akgul, G.; Aksoy, F.; Andersen, K.; Andersson, M.; Anfinrud, Ph.; Baruchel, J.; Bastie, P.; Bau, R.; Blakeley, M.; Bourgeois, D.; Brau, D.; Bravin, A.; Cammarata, M.; Christensen, M.; Cole, J.; Courtois, P.; Cousson, A.; Eggonopoulos-Papadopoulos, B.; Daoud-Aladine, M.A.; Dera, P.; Feng, R.; Fiedler, St.; Fischer, H.; Fisher, St.; Folami, S.; Fosu, M.A.; Fuente, F.; Fullagar, W.; Fulla Marsa, D.; Ghosh, R.; Giles, C.; Goossens, D.; Goujon, A.; Gutmann, M.; Heger, G.; Henry, E.; Hewat, A.; Hossmann, Ch.; Ivanov, A.; Jauch, W.; Jorgensen, R.; Katona, G.; Keen, D.; Kong, Q.; Koshihara, Sh.Y.; Lauss, B.; Laue, M.V.; Lecomte, C.; Legrand, V.; Lemee-Cailleau, M.H.; Marmeggi, J.C.; Martinez-Criado, G.; Mason, S.; McIntyre, G.; Mailleur, F.; Micha, J.S.; Moffat, K.; Mohammed Mustapha, A.; Ouladdiaf, B.; Pahl, R.; Parise, J.; Pearson, A.; Pecaut, J.; Popov, A.; Prokleska, J.; Raitman, E.; Ren, Z.; Rodriguez-Carvajal, J.; Sasaki, J.; Schmidt, M.; Schotte, F.; Stirling, W.; Suominen Fuller, M.; Tanaka, I.; Timmins, P.; Tomking, P.; Turner, M.; Van Thor, J.; Vettier, Ch.; Wildes, A.; Wilson, Ch.; Wohri, A.; Wulf, M.; Zhao, Y

    2007-07-01

    Laue diffraction is currently undergoing a lively renaissance due to new instrumental developments at both synchrotron X-ray and neutron sources. The aim of the workshop Laue-2007 is to offer state-of-the-art experimental methods and hands-on experience of data analysis for exploration, using single-crystal Laue diffraction, of the crystalline structure of complex materials in extreme cases. The oral sessions cover the following topics: -) history and renaissance of Laue diffraction, -) modern X-ray techniques, -) modern neutron techniques, -) applications, -) analysis and software demonstrations including hands-on experience, and -) future directions. This document gathers the abstracts of the presentations and of the posters.

  6. Von Laue's theorem and its applications

    CERN Document Server

    Wang, Changbiao

    2012-01-01

    Von Laue's theorem is strictly proved in detail to clarify confusions in textbook and literature. This theorem is used to analyze the classical electron and the static electric field confined in a finite region of space.

  7. Development of multilayer Laue Lenses for soft X-ray radiation

    Energy Technology Data Exchange (ETDEWEB)

    Liese, Tobias; Krebs, Hans-Ulrich [Institut fuer Materialphysik, Universitaet Goettingen (Germany); Reese, Michael; Grossmann, Peter; Mann, Klaus [Laser-Laboratorium Goettingen e.V. (Germany)

    2010-07-01

    Despite the improvements of fabrication techniques for Fresnel zone plates as diffractive optics for X-ray microscopy, the spatial resolution with high diffraction efficiencies has reached a limit mostly. A novel approach to focusing soft X-rays in the water window regime (2.3-4.4 nm) is to prepare non-periodic multilayer structures using as 1-dimensional zone plates in Laue diffraction geometry. For this purpose ZrO{sub 2}/Ti multilayers were deposited by pulsed laser deposition (PLD) on Si(111) substrates in ultrahigh vacuum. The interfaces within the multilayer are positioned according to the Fresnel zone plate law. In this contribution, results of the Laue Lens fabrication by focused ion beam (FIB) and lens characteristics measured by a table-top X-ray source are presented.

  8. An Ultrasonic Lens Design Based on Prefractal Structures

    Directory of Open Access Journals (Sweden)

    Sergio Castiñeira-Ibáñez

    2016-04-01

    Full Text Available The improvement in focusing capabilities of a set of annular scatterers arranged in a fractal geometry is theoretically quantified in this work by means of the finite element method (FEM. Two different arrangements of rigid rings in water are used in the analysis. Thus, both a Fresnel ultrasonic lens and an arrangement of rigid rings based on Cantor prefractals are analyzed. Results show that the focusing capacity of the modified fractal lens is better than the Fresnel lens. This new lens is believed to have potential applications for ultrasonic imaging and medical ultrasound fields.

  9. Time of flight Laue fiber diffraction studies of perdeuterated DNA

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, V.T.; Whalley, M.A.; Mahendrasingam, A.; Fuller, W. [Keele Univ. (United Kingdom)] [and others

    1994-12-31

    The diffractometer SXD at the Rutherford Appleton Laboratory ISIS pulsed neutron source has been used to record high resolution time-of-flight Laue fiber diffraction data from DNA. These experiments, which are the first of their kind, were undertaken using fibers of DNA in the A conformation and prepared using deuterated DNA in order to minimis incoherent background scattering. These studies complement previous experiments on instrument D19 at the Institute Laue Langevin using monochromatic neutrons. Sample preparation involved drawing large numbers of these deuterated DNA fibers and mounting them in a parallel array. The strategy of data collection is discussed in terms of camera design, sample environment and data collection. The methods used to correct the recorded time-of-flight data and map it into the final reciprocal space fiber diffraction dataset are also discussed. Difference Fourier maps showing the distribution of water around A-DNA calculated on the basis of these data are compared with results obtained using data recorded from hydrogenated A-DNA on D19. Since the methods used for sample preparation, data collection and data processing are fundamentally different for the monochromatic and Laue techniques, the results of these experiments also afford a valuable opportunity to independently test the data reduction and analysis techniques used in the two methods.

  10. Integral freeform illumination lens design of LED based pico-projector.

    Science.gov (United States)

    Zhao, Shuang; Wang, Kai; Chen, Fei; Qin, Zong; Liu, Sheng

    2013-05-01

    In this paper, an illumination lens design for a LED-based pico-projector is presented. Different from the traditional illumination systems composed by lens group, the integral illumination lens consists of a total internal reflector (TIR) and a freeform surface. TIR acts as collimation lens and its top surface formed by a freeform surface reshapes the nonuniform circular light pattern generated by TIR to be rectangular and uniform. Diameter and height of the lens are 16 and 10 mm, respectively. An optimization method to deal with the problem of extended light source is also presented in detail in this paper. According to the simulation results of the final optimized lens, 77% (neglecting the effect of polarization) of the power of light source is collected on liquid crystal on silicon panel with a 16∶9 ratio and illumination uniformity achieves 92%.

  11. Optimizing distance image quality of an aspheric multifocal intraocular lens using a comprehensive statistical design approach.

    Science.gov (United States)

    Hong, Xin; Zhang, Xiaoxiao

    2008-12-01

    The AcrySof ReSTOR intraocular lens (IOL) is a multifocal lens with state-of-the-art apodized diffractive technology, and is indicated for visual correction of aphakia secondary to removal of cataractous lenses in adult patients with/without presbyopia, who desire near, intermediate, and distance vision with increased spectacle independence. The multifocal design results in some optical contrast reduction, which may be improved by reducing spherical aberration. A novel patent-pending approach was undertaken to investigate the optical performance of aspheric lens designs. Simulated eyes using human normal distributions were corrected with different lens designs in a Monte Carlo simulation that allowed for variability in multiple surgical parameters (e.g. positioning error, biometric variation). Monte Carlo optimized results indicated that a lens spherical aberration of -0.10 microm provided optimal distance image quality.

  12. Gradient-index ophthalmic lens design and polymer material studies

    Science.gov (United States)

    Fischer, David Joel

    Unifocal ophthalmic lenses are conventionally designed using homogeneous glass or plastic materials and aspheric surfaces. The desired power and aberration correction are provided by selection of surface shape and refractive index. This thesis studies the design of ophthalmic lenses utilizing gradient-index (GRIN) materials for both the optical power and aberration control. This is done using geometrical optical theory and ray-tracing simulations. Progressive addition lenses (PALS) are vision correction lenses with a continuous change in power used to treat presbyopia. The power variation is typically located in the lower half of the lens. Progressive addition lenses are currently made with aspheric surfaces to achieve the focal power transition and aberration control. These surfaces have at most, mirror symmetry about the vertical axis. The possible design of progressive addition lenses with GRIN materials has not been well studied. This thesis studies PALS and identifies how gradient-index materials can be used to provide both the power progression and aberration control. The optical theory for rotationally symmetric and asymmetric power additions is given. Analytical and numerical methods for calculating the index profile are used, and the results examined using ray-tracing simulations. The theory developed for ophthalmic lenses is applied to the design of GRIN axicon. This is the first GRIN axicon manufactured, and is fabricated using ion-exchanged GRIN glass. Experimental measurements of its performance are compared and found to match theoretical predictions. This demonstrates the generality of the theory developed: it may be applied to non-visual applications, and even to non-imaging applications. Realistic implementation of GRIN technology to ophthalmic application requires the fabrication of large scale refractive index gradients in polymer material systems. The methyl-methacrylate/styrene copolymer system is studied to develop an empirical model of its

  13. Deconvolution method in designing freeform lens array for structured light illumination.

    Science.gov (United States)

    Ma, Donglin; Feng, Zexin; Liang, Rongguang

    2015-02-10

    We have developed a deconvolution freeform lens array design approach to generate high-contrast structured light illumination patterns. This method constructs the freeform lens array according to the point response obtained by deconvoluting the prescribed illumination pattern with the blur response of the extended light source. This design method is more effective in designing a freeform lens array to achieve accurate structured light patterns. For a sinusoidal fringe pattern, the contrast ratio can be as high as 97%, compared to 62% achieved by the conventional ray mapping method.

  14. Design of Novel Compound Fresnel Lens for High-Performance Photovoltaic Concentrator

    Directory of Open Access Journals (Sweden)

    Lei Jing

    2012-01-01

    Full Text Available We present a new design of compound Fresnel-R concentrator which is composed of two lenses: a primary lens (Fresnel lens that works by total internal reflection at outer sawteeth but refraction at inner sawteeth, and a ringed secondary lens that works by refraction. In contrast to previous Fresnel lens concentrators, this design increases the acceptance angle, improves the irradiance uniformity on the solar cell, and reduces the aspect ratio significantly. Meanwhile several sawteeth of the primary Fresnel lens can correspond to a same ring of secondary lens, which will efficiently lower the complexity of designing and manufacturing. Moreover, in order to reduce the influence of manufacturing tolerances and to increase the optical efficiency further, the central part of the bottom of the secondary lens which directly adhered to the solar cell is designed as a cone-shaped prism to collect the sunlight that does not reach the solar cell. Finally, we provide simulations and analyses of the design method an optical efficiency more than 80% and an aspect ratio smaller than 0.5 can be achieved.

  15. Design of tracking and detecting lens system by diffractive optical method

    Science.gov (United States)

    Yang, Jiang; Qi, Bo; Ren, Ge; Zhou, Jianwei

    2016-10-01

    Many target-tracking applications require an optical system to acquire the target for tracking and identification. This paper describes a new detecting optical system that can provide automatic flying object detecting, tracking and measuring in visible band. The main feature of the detecting lens system is the combination of diffractive optics with traditional lens design by a technique was invented by Schupmann. Diffractive lens has great potential for developing the larger aperture and lightweight lens. First, the optical system scheme was described. Then the Schupmann achromatic principle with diffractive lens and corrective optics is introduced. According to the technical features and requirements of the optical imaging system for detecting and tracking, we designed a lens system with flat surface Fresnel lens and cancels the optical system chromatic aberration by another flat surface Fresnel lens with effective focal length of 1980mm, an F-Number of F/9.9 and a field of view of 2ωω = 14.2', spatial resolution of 46 lp/mm and a working wavelength range of 0.6 0.85um. At last, the system is compact and easy to fabricate and assembly, the diffuse spot size and MTF function and other analysis provide good performance.

  16. A simulation study on the focal plane detector of the LAUE project

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M., E-mail: mkhalil@in2p3.fr [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); Frontera, F. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Caroli, E. [INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Virgilli, E.; Valsan, V. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy)

    2015-06-21

    The LAUE project, supported by the Italian Space Agency (ASI), is devoted to the development of a long focal length (even 20 m or longer) Laue lens for gamma ray astronomy between 80 and 600 keV. These lenses take advantage of Bragg diffraction to focus radiation onto a small spot drastically improving the signal to noise ratio as well as reducing the required size of the detector significantly. In this paper we present a Monte-Carlo simulation study with MEGALIB to optimize, for space applications, the detector size to achieve high detection efficiency, and to optimize the position resolution of the detector to reconstruct the Point Spread Function of the lens considered for the LAUE project. Then we will show simulations, using the SILVACO semiconductor simulation toolkit, on the optimized detector to estimate its capacitance per channel and depletion voltage. In all of the simulations, two materials were compared; a low density material (Silicon) and a high density material (Germanium). - Highlights: • The quantized Hall plateaus and Shubnikov de Haas oscillations in transition metal doped topological insulators are observed. • The evidence of a two-dimensional/layered transport of the bulk electrons is reported. • An obvious ferromagnetism in doped topological insulators is observed. • Care should be taken to pindown the transport of the topological SS in topological insulators.

  17. Two-lens designs for modern uncooled and cooled IR imaging devices

    Science.gov (United States)

    Schuster, Norbert; Franks, John

    2013-10-01

    In recent years, thermal detectors with a 17 μm pixel pitch have become well-established for use in various applications, such as thermal imaging in cars. This has allowed the civilian infrared market to steadily mature. The main cost for these lens designs comes from the number of lenses used. The development of thermal detectors, which are less sensitive than quantum detectors, has compelled camera manufacturers to demand very fast F-numbers such as f/1.2 or faster. This also minimizes the impact of diffraction in the 8-12 μmm waveband. The freedom afforded by the choice of the stop position in these designs has been used to create high-resolution lenses that operate near the diffraction limit. Based on GASIR®1, a chalcogenide glass, two-lens designs have been developed for all pixel counts and fields of view. Additionally, all these designs have been passively athermalized, either optically or mechanically. Lenses for cooled quantum detectors have a defined stop position called the cold stop (CS) near the FPA-plane. The solid angle defined by the CS fixes not only the F-number (which is less fast than for thermal detectors), but determines also the required resolution. The main cost driver of these designs is the lens diameter. Lenses must be sufficiently large to avoid any vignetting of ray bundles intended to reach the cooled detector. This paper studies the transfer of approved lens design principles for thermal detectors to lenses for cooled quantum detectors with CS for same pixel count at three horizontal fields of view: a 28° medium field lens, an 8° narrow field lens, and a 90° wide field lens. The lens arrangements found for each category have similar lens costs.

  18. Improving the lens design and performance of a contemporary electromagnetic shock wave lithotripter

    Science.gov (United States)

    Neisius, Andreas; Smith, Nathan B.; Sankin, Georgy; Kuntz, Nicholas John; Madden, John Francis; Fovargue, Daniel E.; Mitran, Sorin; Lipkin, Michael Eric; Simmons, Walter Neal; Preminger, Glenn M.; Zhong, Pei

    2014-01-01

    The efficiency of shock wave lithotripsy (SWL), a noninvasive first-line therapy for millions of nephrolithiasis patients, has not improved substantially in the past two decades, especially in regard to stone clearance. Here, we report a new acoustic lens design for a contemporary electromagnetic (EM) shock wave lithotripter, based on recently acquired knowledge of the key lithotripter field characteristics that correlate with efficient and safe SWL. The new lens design addresses concomitantly three fundamental drawbacks in EM lithotripters, namely, narrow focal width, nonidealized pulse profile, and significant misalignment in acoustic focus and cavitation activities with the target stone at high output settings. Key design features and performance of the new lens were evaluated using model calculations and experimental measurements against the original lens under comparable acoustic pulse energy (E+) of 40 mJ. The −6-dB focal width of the new lens was enhanced from 7.4 to 11 mm at this energy level, and peak pressure (41 MPa) and maximum cavitation activity were both realigned to be within 5 mm of the lithotripter focus. Stone comminution produced by the new lens was either statistically improved or similar to that of the original lens under various in vitro test conditions and was significantly improved in vivo in a swine model (89% vs. 54%, P = 0.01), and tissue injury was minimal using a clinical treatment protocol. The general principle and associated techniques described in this work can be applied to design improvement of all EM lithotripters. PMID:24639497

  19. Improving the lens design and performance of a contemporary electromagnetic shock wave lithotripter.

    Science.gov (United States)

    Neisius, Andreas; Smith, Nathan B; Sankin, Georgy; Kuntz, Nicholas John; Madden, John Francis; Fovargue, Daniel E; Mitran, Sorin; Lipkin, Michael Eric; Simmons, Walter Neal; Preminger, Glenn M; Zhong, Pei

    2014-04-01

    The efficiency of shock wave lithotripsy (SWL), a noninvasive first-line therapy for millions of nephrolithiasis patients, has not improved substantially in the past two decades, especially in regard to stone clearance. Here, we report a new acoustic lens design for a contemporary electromagnetic (EM) shock wave lithotripter, based on recently acquired knowledge of the key lithotripter field characteristics that correlate with efficient and safe SWL. The new lens design addresses concomitantly three fundamental drawbacks in EM lithotripters, namely, narrow focal width, nonidealized pulse profile, and significant misalignment in acoustic focus and cavitation activities with the target stone at high output settings. Key design features and performance of the new lens were evaluated using model calculations and experimental measurements against the original lens under comparable acoustic pulse energy (E+) of 40 mJ. The -6-dB focal width of the new lens was enhanced from 7.4 to 11 mm at this energy level, and peak pressure (41 MPa) and maximum cavitation activity were both realigned to be within 5 mm of the lithotripter focus. Stone comminution produced by the new lens was either statistically improved or similar to that of the original lens under various in vitro test conditions and was significantly improved in vivo in a swine model (89% vs. 54%, P = 0.01), and tissue injury was minimal using a clinical treatment protocol. The general principle and associated techniques described in this work can be applied to design improvement of all EM lithotripters.

  20. STRONG LENS TIME DELAY CHALLENGE. I. EXPERIMENTAL DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    Dobler, Gregory [Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, CA 93106 (United States); Fassnacht, Christopher D.; Rumbaugh, Nicholas [Department of Physics, University of California, 1 Shields Avenue, Davis, CA 95616 (United States); Treu, Tommaso; Liao, Kai [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Marshall, Phil [Kavli Institute for Particle Astrophysics and Cosmology, P.O. Box 20450, MS29, Stanford, CA 94309 (United States); Hojjati, Alireza [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada); Linder, Eric, E-mail: tt@astro.ucla.edu [Lawrence Berkeley National Laboratory and University of California, Berkeley, CA 94720 (United States)

    2015-02-01

    The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ∼10{sup 3} strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a ''Time Delay Challenge'' (TDC). The challenge is organized as a set of ''ladders'', each containing a group of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.

  1. RF Lens-Embedded Massive MIMO Systems: Fabrication Issues and Codebook Design

    Science.gov (United States)

    Kwon, Taehoon; Lim, Yeon-Geun; Min, Byung-Wook; Chae, Chan-Byoung

    2016-07-01

    In this paper, we investigate a radio frequency (RF) lens-embedded massive multiple-input multiple-output (MIMO) system and evaluate the system performance of limited feedback by utilizing a technique for generating a suitable codebook for the system. We fabricate an RF lens that operates on a 77 GHz (mmWave) band. Experimental results show a proper value of amplitude gain and an appropriate focusing property. In addition, using a simple numerical technique--beam propagation method (BPM)--we estimate the power profile of the RF lens and verify its accordance with experimental results. We also design a codebook--multi-variance codebook quantization (MVCQ)--for limited feedback by considering the characteristics of the RF lens antenna for massive MIMO systems. Numerical results confirm that the proposed system shows significant performance enhancement over a conventional massive MIMO system without an RF lens.

  2. The Design of Lens Imaging System by Means of Fractional Fourier Transform

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiannong; XU Qiang; D.R.Selviah

    2002-01-01

    The relation between the 2nd fractional Fourier transform and the imaging process of an optical system is discussed. By changing the coordinate scales of the input plane in respect to the magnification of the optical imaging system, the fractional Fourier transform can be a powerful tool in designing specific imaging system. The Gaussian imaging formula of single lens is obtained by using the tool. Finally the procedures are generalized for designing a double-lens imaging system through an example.

  3. Optical design of f-theta lens for dual wavelength selective laser melting

    Science.gov (United States)

    Feng, Lianhua; Cao, Hongzhong; Zhang, Ning; Xu, Xiping; Duan, Xuanming

    2016-10-01

    F-theta lens is an important unit for selective laser melting (SLM) manufacture. The dual wavelength f-theta lens has not been used in SLM manufacture. Here, we present the design of the f-theta lens which satisfies SLM manufacture with coaxial 532 nm and 1030 nm 1080 nm laser beams. It is composed of three pieces of spherical lenses. The focal spots for 532 nm laser and 1030 nm 1080 nm laser are smaller than 35 μm and 70 μm, respectively. The results meet the demands of high precision SLM. The chromatic aberration could cause separation between two laser focal spots in the scanning plane, so chromatic aberration correction is very important to our design. The lateral color of the designed f-theta lens is less than 11 μm within the scan area of 150 mm x 150 mm, which meet the application requirements of dual wavelength selective laser melting.

  4. Strong Lens Time Delay Challenge: I. Experimental Design

    CERN Document Server

    Dobler, Gregory; Treu, Tommaso; Marshall, Phillip J; Liao, Kai; Hojjati, Alireza; Linder, Eric; Rumbaugh, Nicholas

    2013-01-01

    The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters as well as probe the dark matter (sub-)structure within the lens galaxy. The number of lenses with measured time delays is growing rapidly as a result of some dedicated efforts; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ~1000 lens systems consisting of a foreground elliptical galaxy producing multiple images of a background quasar. In an effort to assess the present capabilities of the community to accurately measure the time delays in strong gravitational lens systems, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we invite the community to take part in a "Time Delay Challenge" (TDC). The challenge is organized as a set of "ladders", each containing a group of simulated datasets to be analyzed blindly by participating independent analysis teams. Each rung on a ladder consists of a set of realistic mock observed le...

  5. New concentrator multifocal Fresnel lens for improved uniformity: design and characterization

    Science.gov (United States)

    Vázquez-Moliní, Daniel; Fernández-Balbuena, Antonio Álvarez; Bernabeu, Eusebio; Muñoz de Luna Clemente, Javier; Domingo-Marique, Alfonso; García-Botella, Ángel

    2009-08-01

    The emergence of high efficiency photovoltaic cells is leading the industry into using solar concentrators in order to reduce costs by decreasing the number of cells used. In this paper Optics department of Universidad Complutense de Madrid has designed a multifocal Fresnel lens of PMMA and has studied the main parameters that have influence on its final function. This has been done by taking into account its manufacturing tolerances. The lens is square shaped with sides measuring 270 mm and it is composed of three different zones based on three different criteria: The central zone has been designed by using paraxial formulation, the intermediate one has been designed based on Fresnel classical formula while the marginal zone's purpose is to deflect the light by total internal reflection on prism faces. All three zones have different focal areas and different optical axis so the energy distribution will be more uniform whilst avoiding cell damage caused by hot spots. The design stage is feedback through simulations using a ray tracer software. In order to characterize the lens operation a measure of optical concentration was first taken on different lens areas using an integrating sphere. Finally, the lens performance in terms of concentration and in terms of uniformity at the focal spot was studied by processing the images taken with a CCD camera on a screen placed at the focal plane of the lens.

  6. Athermal design for mid-wave infrared lens with long EFFL

    Science.gov (United States)

    Bai, Yu; Xing, Tingwen

    2016-10-01

    When the environment temperature has changed, then each parameter in infrared lens has also changed, thus the image quality became bad, so athermal technology is one of key technology in designing infrared lens. The temperature influence of each parameter in infrared lens is analyzed in the paper. In the paper, an athermal mid-wave infrared optical system with long focal length by Code-v optical design software was presented. The parameters of the athermal infrared system are 4.0 f/number, 704mm effective focal length (EFL) , 1° field of view and 3.7-4.8 μm spectrum region 100% cold shield efficiency. When the spatial frequency is 16lp/mm, the Modulation Transfer Function (MTF) of all the field of view was above 0.5 from the working temperature range -40° to 60°. From the image quality and thermal analysis result, we knew that the lens had good athermal performance.

  7. Analysis, Design and Fabrication of centimeter-wave Dielectric Fresnel Zone Plate Lens and reflector

    CERN Document Server

    Mahmoudi, A; Mahmoudi, Ali; Azalzadeh, Reza

    2005-01-01

    Fresnel lens has a long history in optics. This concept at non-optical wavelengths is also applicable. In this paper we report design and fabrication of a half and quarter wave dielectric Fresnel lens made of Plexiglas, and a Fresnel reflector at 11.1 GHz frequency. We made two lenses and one reflector at same frequency and compare their gain and radiation pattern to simulated results. Some methods for better focusing action will be introduced.

  8. First-order method of zoom lens design by means of generalized parameters.

    Science.gov (United States)

    Khorokhorov, Alexei M; Piskunov, Dmitry E; Shirankov, Alexander F

    2016-08-01

    A method of paraxial zoom lens design is proposed that makes it possible to determine the optical powers and component movements of a zoom lens with the required zoom ratio. The method is based on the theory of generalized parameters, which can be used to analyze a zoom system by varying only one parameter. All possible zoom lenses with two movable components are considered for an object at infinity.

  9. Meta-lens design with low permittivity dielectric materials through smart transformation optics

    Science.gov (United States)

    Kim, Junhyun; Shin, Dongheok; Choi, Seungjae; Yoo, Do-Sik; Seo, Ilsung; Kim, Kyoungsik

    2015-09-01

    We report here a design method based on smart transformation optics (STO) to control the range of the permittivity values of the materials required to manufacture transformation optics devices. In particular, we show that it is possible to reduce the maximum electric permittivity value required to realize a STO device with certain functionality by means of a simple conceptual elastic stretching process. We illustrate the design procedure with two types of collimator meta-lens designs, which we call warping space collimator meta-lens and half fisheye collimator meta-lens, respectively. We provide design examples of these two types of lenses with the help of COMSOL Multiphysics software. These two design examples are fabricated with commonly available dielectric materials by means of 3D printing technology. For the functional verification of these two collimator lenses, we provide measurement results obtained with transverse electric waves of frequency range 7-13GHz.

  10. Application of Q-type aspheric surface in the design of Wynne-Dyson projection lens

    Science.gov (United States)

    Ho, Cheng-Fang; Peng, Wei-Jei; Hsu, Wei-Yao

    2016-10-01

    ITRC dedicates in high precision optics for more than 40 years and focuses in lithography optics for projection system recently. The first project of the lithography optics in ITRC is an i-line Wynne-Dyson projection lens for 3D-ICs applications. The Wynne-Dyson projection lens is a classical design for unity magnification projection system. We take the advantages of the established benefits of Wynne-Dyson lens and modify it. ITRC`s Wynne-Dyson lens is a 0.16 NA system with unity magnification, which is designed in double telecentricity and long working distance. The projection lens comprises three lenses and one concave mirror. Two aspheric surfaces are deployed in lens 1 and concave mirror. A lens with aspheric surfaces can correct for aberration and deliver a higher performance with fewer lens elements; therefore it has advantages of compact and light. However, aspheres are more difficult to fabricate and higher cost than spherical surface. In order to control the testability and manufacturability of the aspheric surface, the Q-type aspheric surfaces are applied in our design phase and manufacture process. We optimize for both performance and manufacturability by Q-type aspheric surfaces. Not only a testable and manufacturable asphere can be approached but also an additional benefits of less sensitive and cost-effective to manufacture to the required specification. In this paper, the Q-type aspheric surfaces and slope constraint are applied to a Wynne-Dyson projection lens, the testability of Q-type aspheric surfaces by the departure from best-fit-sphere and fringe density of interferometry are estimated. Furthermore, subaperture stitching interferometer system (ASI, from QED technologies) is also applied for testability comparison. The tolerance and sensitivity are also discussed. Finally, the results show a diffraction limit approached lens with testable aspheric surface is designed using Q-type aspheric surface. One of the asphere is 150 m departure from best

  11. Short-focus and ultra-wide-angle lens design in wavefront coding

    Science.gov (United States)

    Zhang, Jiyan; Huang, Yuanqing; Xiong, Feibing

    2016-10-01

    Wavefront coding (WFC) is a hybrid technology designed to increase depth of field of conventional optics. The goal of our research is to apply this technology to the short-focus and ultra-wide-angle lens which suffers from the aberration related with large field of view (FOV) such as coma and astigmatism. WFC can also be used to compensate for other aberration which is sensitive to the FOV. Ultra-wide-angle lens has a little depth of focus because it has small F number and short-focus. We design a hybrid lens combing WFC with the ultra-wide-angle lens. The full FOV and relative aperture of the final design are up to170° and 1/1.8 respectively. The focal length is 2 mm. We adopt the cubic phase mask (CPM) in the design. The conventional design will have a wide variation of the point spread function (PSF) across the FOV and it is very sensitive with the variation of the FOV. The new design we obtain the PSF is nearly invariant over the whole FOV. But the result of the design also shows the little difference between the horizontal and vertical length of the PSF. We analyze that the CPM is non-symmetric phase mask and the FOV is so large, which will generate variation in the final image quality. For that reason, we apply a new method to avoid that happened. We try to make the rays incident on the CPM with small angle and decrease the deformation of the PSF. The experimental result shows the new method to optimize the CPM is fit for the ultra-wide-angle lens. The research above will be a helpful instruction to design the ultra-wide-angle lens with WFC.

  12. Automation Enhancement of Multilayer Laue Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Lauer K. R.; Conley R.

    2010-12-01

    X-ray optics fabrication at Brookhaven National Laboratory has been facilitated by a new, state of the art magnetron sputtering physical deposition system. With its nine magnetron sputtering cathodes and substrate carrier that moves on a linear rail via a UHV brushless linear servo motor, the system is capable of accurately depositing the many thousands of layers necessary for multilayer Laue lenses. I have engineered a versatile and automated control program from scratch for the base system and many subsystems. Its main features include a custom scripting language, a fully customizable graphical user interface, wireless and remote control, and a terminal-based interface. This control system has already been successfully used in the creation of many types of x-ray optics, including several thousand layer multilayer Laue lenses.Before reaching the point at which a deposition can be run, stencil-like masks for the sputtering cathodes must be created to ensure the proper distribution of sputtered atoms. Quality of multilayer Laue lenses can also be difficult to measure, given the size of the thin film layers. I employ my knowledge of software and algorithms to further ease these previously painstaking processes with custom programs. Additionally, I will give an overview of an x-ray optic simulator package I helped develop during the summer of 2010. In the interest of keeping my software free and open, I have worked mostly with the multiplatform Python and the PyQt application framework, utilizing C and C++ where necessary.

  13. Design and experimental study on Fresnel lens of the combination of equal-width and equal-height of grooves

    Science.gov (United States)

    Guo, Limin; Liu, Youqiang; Huang, Rui; Wang, Zhiyong

    2017-06-01

    High concentrating PV systems rely on large Fresnel lens that must be precisely oriented in the direction of the Sun to maintain high concentration ratio. We propose a new Fresnel lens design method combining equal-width and equal-height of grooves in this paper based on the principle of focused spot maximum energy. In the ring band near the center of Fresnel lens, the design with equal-width grooves is applied, and when the given condition is reached, the design with equal-height grooves is introduced near the edges of the Fresnel lens, which ensures all the lens grooves are planar. In this paper, we establish a Fresnel lens design example model by Solidworks, and simulate it with the software ZEMAX. An experimental test platform is built to test, and the simulation correctness is proved by experiments. Experimental result shows the concentrating efficiency of this example is 69.3%, slightly lower than the simulation result 75.1%.

  14. Design and fabrication of concave-convex lens for head mounted virtual reality 3D glasses

    Science.gov (United States)

    Deng, Zhaoyang; Cheng, Dewen; Hu, Yuan; Huang, Yifan; Wang, Yongtian

    2015-08-01

    As a kind of light-weighted and convenient tool to achieve stereoscopic vision, virtual reality glasses are gaining more popularity nowadays. For these glasses, molded plastic lenses are often adopted to handle both the imaging property and the cost of massive production. However, the as-built performance of the glass depends on both the optical design and the injection molding process, and maintaining the profile of the lens during injection molding process presents particular challenges. In this paper, optical design is combined with processing simulation analysis to obtain a design result suitable for injection molding. Based on the design and analysis results, different experiments are done using high-quality equipment to optimize the process parameters of injection molding. Finally, a single concave-convex lens is designed with a field-of-view of 90° for the virtual reality 3D glasses. The as-built profile error of the glass lens is controlled within 5μm, which indicates that the designed shape of the lens is fairly realized and the designed optical performance can thus be achieved.

  15. Spatial filter lens design for the main laser of the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Korniski, R. J., Optics 1 Inc, Westlake Village, CA

    1998-06-05

    The National Ignition Facility (NIF), being designed and constructed at Lawrence Livermore National Laboratory (LLNL), comprises 192 laser beams The lasing medium is neodymium in phosphate glass with a fundamental frequency (1{omega}) of 1 053{micro}m Sum frequency generation in a pair of conversion crystals (KDP/KD*P) will produce 1 8 megajoules of the third harmonic light (3{omega} or {lambda}=351{micro}m) at the target The purpose of this paper is to provide the lens design community with the current lens design details of the large optics in the Main Laser This paper describes the lens design configuration and design considerations of the Main Laser The Main Laser is 123 meters long and includes two spatial filters one 13 5 meters and one 60 meters These spatial filters perform crucial beam filtering and relaying functions We shall describe the significant lens design aspects of these spatial filter lenses which allow them to successfully deliver the appropriate beam characteristic onto the target For an overview of NIF please see ``Optical system design of the National Ignition Facility,`` by R Edward English. et al also found in this volume.

  16. Design and Optimization of Fresnel Lens for High Concentration Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Lei Jing

    2014-01-01

    Full Text Available A practical optimization design is proposed, in which the solar direct light spectrum and multijunction cell response range are taken into account in combination, particularly for the Fresnel concentrators with a high concentration and a small aspect ratio. In addition, the change of refractive index due to temperature variation in outdoor operation conditions is also considered in the design stage. The calculation results show that this novel Fresnel lens achieves an enhancement of energy efficiency of about 10% compared with conventional Fresnel lens for a given solar spectrum, solar cell response, and corrected sunshine hours of different ambient temperature intervals.

  17. Design of macro-filter-lens with simultaneous chromatic and geometric aberration correction.

    Science.gov (United States)

    Prasad, Dilip K; Brown, Michael S

    2014-01-01

    A macro-filter-lens design that can correct for chromatic and geometric aberrations simultaneously while providing for a long focal length is presented. The filter is easy to fabricate since it involves two spherical surfaces and a planar surface. Chromatic aberration correction is achieved by making all the rays travel the same optical distance inside the filter element (negative meniscus). Geometric aberration is corrected for by the lens element (plano-convex), which makes the output rays parallel to the optic axis. This macro-filter-lens design does not need additional macro lenses and it provides an inexpensive and optically good (aberration compensated) solution for macro imaging of objects not placed close to the camera.

  18. High Performance FOV Switching Mechanism Design for an Infrared Zoom Lens

    Directory of Open Access Journals (Sweden)

    Chun-Ju Huang

    2011-12-01

    Full Text Available This paper presents the design and implementation of a prototype dual FOV (field-of-view zoom lens mechanism. The infrared zoom lens uses a permanent magnet DC motor for the motion driver and a microcontroller as the controller. Through the cooperation of two major sensor signals, a shaft encoder and a position sensor, the FOV switching mechanism can achieve both high-speed and high-precision alignment. Experimental results showed an alignment accuracy average of 0.155 mrads and less than 0.5 second alignment settling time. Despite the influence of the non-zero backlash and the A/D uncertainty on the infrared zoom lens, the goal of alignment can be reached by the cooperation between the two major sensors and the controller. The control strategy for switching control was also proposed to help reaching the high-speed precision design specifications.

  19. The design and application of large area intensive lens array focal spots measurement system

    Science.gov (United States)

    Chen, Bingzhen; Yao, Shun; Yang, Guanghui; Dai, Mingchong; Wang, Zhiyong

    2014-12-01

    Concentrating Photovoltaic (CPV) modules are getting thinner and using smaller cells now days. Correspondingly, large area intensive lens arrays with smaller unit dimension and shorter focal length are wanted. However, the size and power center of lens array focal spots usually differ from the design value and are hard to measure, especially under large area situation. It is because the machining error and deformation of material of the lens array are hard to simulate in the optical design process. Thus the alignment error between solar cells and focal spots in the module assembly process will be hard to control. Under this kind of situation, the efficiency of CPV module with thinner body and smaller cells is much lower than expected. In this paper, a design of large area lens array focal spots automatic measurement system is presented, as well as its prototype application results. In this system, a four-channel parallel light path and its corresponding image capture and process modules are designed. These modules can simulate focal spots under sunlight and have the spots image captured and processed using charge coupled devices and certain gray level algorithm. Thus the important information of focal spots such as spot size and location will be exported. Motion control module based on grating scale signal and interval measurement method are also employed in this system in order to get test results with high speed and high precision on large area lens array no less than 1m×0.8m. The repeatability of the system prototype measurement is +/-10μm with a velocity of 90 spot/min. Compared to the original module assembled using coordinates from optical design, modules assembled using data exported from the prototype is 18% higher in output power, reaching a conversion efficiency of over 31%. This system and its design can be used in the focal spot measurement of planoconvex lens array and Fresnel lens array, as well as other kinds of large area lens array application

  20. Design study for a 16x zoom lens system for visible surveillance camera

    Science.gov (United States)

    Vella, Anthony; Li, Heng; Zhao, Yang; Trumper, Isaac; Gandara-Montano, Gustavo A.; Xu, Di; Nikolov, Daniel K.; Chen, Changchen; Brown, Nicolas S.; Guevara-Torres, Andres; Jung, Hae Won; Reimers, Jacob; Bentley, Julie

    2015-09-01

    *avella@ur.rochester.edu Design study for a 16x zoom lens system for visible surveillance camera Anthony Vella*, Heng Li, Yang Zhao, Isaac Trumper, Gustavo A. Gandara-Montano, Di Xu, Daniel K. Nikolov, Changchen Chen, Nicolas S. Brown, Andres Guevara-Torres, Hae Won Jung, Jacob Reimers, Julie Bentley The Institute of Optics, University of Rochester, Wilmot Building, 275 Hutchison Rd, Rochester, NY, USA 14627-0186 ABSTRACT High zoom ratio zoom lenses have extensive applications in broadcasting, cinema, and surveillance. Here, we present a design study on a 16x zoom lens with 4 groups (including two internal moving groups), designed for, but not limited to, a visible spectrum surveillance camera. Fifteen different solutions were discovered with nearly diffraction limited performance, using PNPX or PNNP design forms with the stop located in either the third or fourth group. Some interesting patterns and trends in the summarized results include the following: (a) in designs with such a large zoom ratio, the potential of locating the aperture stop in the front half of the system is limited, with ray height variations through zoom necessitating a very large lens diameter; (b) in many cases, the lens zoom motion has significant freedom to vary due to near zero total power in the middle two groups; and (c) we discuss the trade-offs between zoom configuration, stop location, packaging factors, and zoom group aberration sensitivity.

  1. Study of optical Laue diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarthy, Giridhar, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Allam, Srinivasa Rao, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Satyanarayana, S. V. M., E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Sharan, Alok, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com [Department of Physics, Pondicherry University, Puducherry-605014 (India)

    2014-10-15

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  2. Chaotic behavior in an algorithm to escape from poor local minima in lens design

    NARCIS (Netherlands)

    Van Turnhout, M.; Bociort, F.

    2009-01-01

    In lens design, damped least-squares methods are typically used to find the nearest local minimum to a starting configuration in the merit function landscape. In this paper, we explore the use of such a method for a purpose that goes beyond local optimization. The merit function barrier, which

  3. Design Research through the Lens of Sociology of Technology

    DEFF Research Database (Denmark)

    Berntsen, Hilde Østerås; Seim, Rikke

    2007-01-01

    The use of an approach to design research inspired by Sociology of Technology offers a nuanced understanding of design processes. The purpose of this paper is to explore how terminology derived from the socio-technical theory of Actor Network (ANT) can be used to understand the complexity of design......-design of existing workspace and work practice in an industrial company. The case study (i) illustrates a socio-technical approach to design research and (ii) shows how ANT terminology can be applied in an analysis of the course of events in a design process with numerous actors involved....

  4. Laue optics for nuclear astrophysics: New detector requirements for focused gamma-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Barriere, N. [INAF - IASF Roma, via Fosso del Cavaliere 100, 00133 Roma (Italy)], E-mail: nicolas.barriere@iasf-roma.inaf.it; Ballmoos, P. von [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Abrosimov, N.V. [IKZ, Max Born-Str. 2, D-12489 Berlin (Germany); Bastie, P. [LSP UMR 5588, 140 Av. de la physique, 38402 Saint Martin d' Heres (France); Camus, T. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Courtois, P.; Jentschel, M. [ILL, 6 rue Jules Horowitz, 38042 Grenoble (France); Knoedlseder, J. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Natalucci, L. [INAF - IASF Roma, via Fosso del Cavaliere 100, 00133 Roma (Italy); Roudil, G.; Rousselle, J. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Wunderer, C.B. [SSL, University of California at Berkeley, CA 94708 (United States); Kurlov, V.N. [Institute of Solid State Physics of Russian Academy of Sciences, 142432 Chernogolovka (Russian Federation)

    2009-10-21

    Nuclear astrophysics presents an extraordinary scientific potential for the study of the most powerful sources and the most violent events in the Universe. But in order to take full advantage of this potential, telescopes should be at least an order of magnitude more sensitive than present technologies. Today, Laue lenses have demonstrated their capability of focusing gamma-rays in the 100 keV-1 MeV domain, enabling the possibility of building a new generation of instruments for which sensitive area is decoupled from collecting area. Thus we have now the opportunity of dramatically increase the signal/background ratio and hence improve significantly the sensitivity. With a lens, the best detector is no longer the largest possible within a mission envelope. The point spread function of a Laue lens measures a few centimeters in diameter, but the field of view is limited by the detector size. Requirements for a focal plane instrument are presented in the context of the Gamma-Ray Imager mission (proposed to European Space Agency, ESA in the framework of the first Cosmic Vision AO): a 15-20 cm a side finely pixellated detector capable of Compton events reconstruction seems to be optimal, giving polarization and background rejection capabilities and 30 arcsec of angular resolution within a field of view of 5 arc min.

  5. Conceptual design study of a 5 kilowatt solar dynamic Brayton power system using a dome Fresnel lens solar concentrator

    Science.gov (United States)

    Oneill, Mark J.; Mcdanal, A. J.; Spears, Don H.

    1989-01-01

    The primary project objective was to generate a conceptual design for a nominal 5 kW solar dynamic space power system, which uses a unique, patented, transmittance-optimized, dome-shaped, point-focus Fresnel lens as the optical concentrator. Compared to reflective concentrators, the dome lens allows 200 times larger slope errors for the same image displacement. Additionally, the dome lens allows the energy receiver, the power conversion unit (PCU), and the heat rejection radiator to be independently optimized in configuration and orientation, since none of these elements causes any aperture blockage. Based on optical and thermal trade studies, a 6.6 m diameter lens with a focal length of 7.2 m was selected. This lens should provide 87 percent net optical efficienty at 800X geometric concentration ratio. The large lens is comprised of 24 gores, which compactly stow together during launch, and automatically deploy on orbit. The total mass of the microglass lens panels, the graphite/epoxy support structure, and miscellaneous hardware is about 1.2 kg per square meter of aperture. The key problem for the dome lens approach relates to the selection of a space-durable lens material. For the first time, all-glass Fresnel lens samples were successfully made by a sol-gel casting process.

  6. Eliminating chromatic aberration in Gauss-type lens design using a novel genetic algorithm.

    Science.gov (United States)

    Fang, Yi-Chin; Tsai, Chen-Mu; Macdonald, John; Pai, Yang-Chieh

    2007-05-01

    Two different types of Gauss lens design, which effectively eliminate primary chromatic aberration, are presented using an efficient genetic algorithm (GA). The current GA has to deal with too many targets in optical global optimization so that the performance is not much improved. Generally speaking, achromatic aberrations have a great relationship with variable glass sets for all elements. For optics whose design is roughly convergent, glass sets for optics will play a significant role in axial and lateral color aberration. Therefore better results might be derived from the optimal process of eliminating achromatic aberration, which could be carried out by finding feasible glass sets in advance. As an alternative, we propose a new optimization process by using a GA and involving theories of geometrical optics in order to select the best optical glass combination. Two Gauss-type lens designs are employed in this research. First, a telephoto lens design is sensitive to axial aberration because of its long focal length, and second, a wide-angle Gauss design is complicated by lateral color aberration at the extreme corners because Gauss design is well known not to deal well with wide-angle problems. Without numbers of higher chief rays passing the element, it is difficult to correct lateral color aberration altogether for the Gauss design. The results and conclusions show that the attempts to eliminate primary chromatic aberrations were successful.

  7. Practical guide to saddle-point construction in lens design

    NARCIS (Netherlands)

    Bociort, F.; Van Turnhout, M.; Marinescu, O.

    2007-01-01

    Saddle-point construction (SPC) is a new method to insert lenses into an existing design. With SPC, by inserting and extracting lenses new system shapes can be obtained very rapidly, and we believe that, if added to the optical designer’s arsenal, this new tool can significantly increase design prod

  8. Practical guide to saddle-point construction in lens design

    NARCIS (Netherlands)

    Bociort, F.; Van Turnhout, M.; Marinescu, O.

    2007-01-01

    Saddle-point construction (SPC) is a new method to insert lenses into an existing design. With SPC, by inserting and extracting lenses new system shapes can be obtained very rapidly, and we believe that, if added to the optical designer’s arsenal, this new tool can significantly increase design

  9. Gradient Index Polymer Optics: Achromatic Singlet Lens Design

    Science.gov (United States)

    2010-01-01

    achromatic singlet lenses. The designs are based on gradient index lenses fabricated from nanolayered polymer materials. Raytraced results confirm the...fabricated from nanolayered polymer materials. Raytraced results confirm the achromatic performance of the designs. OCIS codes: (110.2760) Gradient...lenses in Zemax®. In order to model these lenses, user-defined surfaces had to be developed for the software. RL RG z y • • Δz • tc •n0 n1• Raytrace

  10. Free-form thin lens design with light scattering surfaces for practical LED down light illumination

    Science.gov (United States)

    Lin, Raychiy J.; Sun, Ching-Cherng

    2016-05-01

    The free-form optical quasilens surface technology was utilized to develop and design a solid transparent plastic optical lens for the LED down light with the narrow angular light distribution requirement in the LED lighting applications. In order to successfully complete the mission, the precise mid-field angular distribution model of the LED light source was established and built. And also the optical scattering surface property of the Harvey BSDF scattering model was designed, measured, and established. Then, the optical simulation for the entire optical system was performed to develop and design this solid transparent plastic optical lens system. Finally, the goals of 40 deg angular light distribution pattern defined at full width half maximum with glare reduced in the areas of interest and the optical performance of nearly 82% light energy transmission optics were achieved for the LED down light illumination.

  11. Optical design and multiobjective optimization of miniature zoom optics with liquid lens element.

    Science.gov (United States)

    Sun, Jung-Hung; Hsueh, Bo-Ren; Fang, Yi-Chin; MacDonald, John; Hu, Chao-Chang

    2009-03-20

    We propose an optical design for miniature 2.5x zoom fold optics with liquid elements. First, we reduce the volumetric size of the system. Second, this newly developed design significantly reduces the number of moving groups for this 2.5x miniature zoom optics (with only two moving groups compared with the four or five groups of the traditional zoom lens system), thanks to the assistance of liquid lens elements in particular. With regard to the extended optimization of this zoom optics, relative illuminance (RI) and the modulation transfer function (MTF) are considered because the more rays passing through the edge of the image, the lower will be the MTF, at high spatial frequencies in particular. Extended optimization employs the integration of the Taguchi method and the robust multiple criterion optimization (RMCO) approach. In this approach, a Pareto optimal robust design solution is set with the aid of a certain design of the experimental set, which uses analysis of variance results to quantify the relative dominance and significance of the design factors. It is concluded that the Taguchi method and RMCO approach is successful in optimizing the RI and MTF values of the fold 2.5x zoom lens system and yields better and more balanced performance, which is very difficult for the traditional least damping square method to achieve.

  12. Design of an LED Spotlight Lens%一种LED射灯透镜的设计

    Institute of Scientific and Technical Information of China (English)

    谢拥军; 徐健; 苏丹

    2014-01-01

    The generatrix of collimating total internal reflection ( TIR) lens is obtained against point source model via mathematical modeling with Snell’s law and Fermat principle, and then the fly-eye lens is designed to control the divergence angle of the emergent light. The TIR lens is modeled with 3D software and used in conjunction with extended source 3030 LED. The design meets the requirements after the simulation verification of optical software. Finally, the effects of aperture value of fly-eye lens and arrangement density on light-emitting angle of the emergent light and central light intensity are discussed and analyzed. Its conclusion helps to reduce the development period of such lens.%利用斯涅尔定律、费马原理,针对点光源模型,通过数学建模得到准直全内反射(Total internal reflection, TIR)透镜的母线,再通过设计复眼透镜来控制其出射光的发散角。利用3D软件完成复眼TIR透镜建模,并将其与扩展光源3030 LED配合使用,经光学软件模拟验证,达到了设计要求。最后讨论并分析了复眼透镜孔径值、复眼透镜的排列密度对出发光角度、中心光强的影响,其结论有助于缩短此类透镜的开发周期。

  13. Using GRIN to save 50% lens weight for an 8x rifle scope design

    Science.gov (United States)

    Flynn, R. A.; Beadie, G.

    2017-05-01

    Starting with a literature-based design for a rifle scope, we demonstrate the potential to replace large, heavy glass lenses with polymer-based GRIN lenses with little optical penalty, while saving 50% of the lens weight in the system. Several properties of the primary design are chosen to favor manufacturability, such as leaving glass for the external surfaces and choosing polymers and GRIN geometries based on proven fabrication techniques. Compared to the reference design which weighed 154 g, the GRIN-substituted design weighed 78 g while maintaining visually constant performance from 0-40°C.

  14. Design, characterization and visual performance of a new multizone contact lens

    CERN Document Server

    Rodriguez-Vallejo, Manuel; Monsoriu, Juan A; Furlan, Walter D

    2016-01-01

    Objectives: To analyze the whole process involved in the production of a new bifocal Multizone Contact Lens (MCL) for presbyopia. Methods: The optical quality of a new MCL was evaluated by ray tracing software in a model eye with pupil different diameters with the lens centered and decentered. A stock of low addition (+1.5 D) MCL for presbyopia was ordered for manufacturing. Power profiles were measured with a contact lens power mapper, processed with a custom software and compared with the theoretical design. Nine lenses from the stock were fitted to presbyopic subjects and the visual performance was evaluated with new APPs for iPad Retina. Results: Numerical simulations showed that the trough the focus curve provided by MCL has an extended depth of focus. The optical quality was not dependent on pupil size and only decreased for lens decentered with a pupil diameter of 4.5 mm. The manufactured MCL showed a smoothed power profile with a less-defined zones. The bias between experimental and theoretical zone s...

  15. FEA Analysis of AP-0 Target Hall Collection Lens (Current Design)

    Energy Technology Data Exchange (ETDEWEB)

    Hurh, P.G.; Tang, Z.

    2001-06-22

    The AP-0 Target Hall Collection Lens is a pulsed device which focuses anti-protons just downstream of the Target. Since the angles at which the anti-protons depart the Target can be quite large, a very high focusing strength is required to maximize anti-proton capture into the downstream Debuncher Ring. The current design of the Collection Lens was designed to operate with a focusing gradient of 1,000 T/m. However, multiple failures of early devices resulted in lowering the normal operating gradient to about 750 T/m. At this gradient, the Lens design fares much better, lasting several million pulses, but ultimately still fails. A Finite Element Analysis (FEA) has been performed on this Collection Lens design to help determine the cause and/or nature of the failures. The Collection Lens magnetic field is created by passing high current through a central conductor cylinder. A uniform current distribution through the cylinder will create a tangential or azimuthal magnetic field that varies linearly from zero at the center of the cylinder to a maximum at the outer surface of the cylinder. Anti-proton particles passing through this cylinder (along the longitudinal direction) will see an inward focusing kick back toward the center of the cylinder proportional to the magnetic field strength. For the current Lens design a gradient of 1,000 T/m requires a current of about 580,000 amps. Since the DC power and cooling requirements would be prohibitive, the Lens is operated in a pulsed mode. Each pulse is half sine wave in shape with a pulse duration of about 350 microseconds. Because of the skin effect, the most uniform current density actually occurs about two-thirds of the way through the pulse. This means that the maximum current of the pulse is actually higher than that required in the DC case (about 670,000 amps). Since the beam must pass through the central conductor cylinder it must be made of a conducting material that is also very 'transparent' to the beam

  16. Advancements in transformation optics-enabled gradient-index lens design

    Science.gov (United States)

    Campbell, Sawyer D.; Brocker, Donovan E.; Nagar, Jogender; Easum, John A.; Werner, Douglas H.; Werner, Pingjuan L.

    2015-09-01

    Transformation Optics (TO) provides the mathematical framework for representing the behavior of electromagnetic radiation in a given geometry by "transforming" it to an alternative, usually more desirable, geometry through an appropriate mapping of the constituent material parameters. Using a quasi-conformal mapping, the restrictions on the required material parameters can be relaxed allowing isotropic inhomogeneous all-dielectric materials to be employed. This approach has led to the development of a new and powerful design tool for gradient-index (GRIN) optical systems. Using TO, aspherical lenses can be transformed to simpler spherical and flat geometries or even rotationally-asymmetric shapes which result in true 3D GRIN profiles. TO can also potentially be extended to collapse an entire lens system into a representative GRIN profile thus reducing its physical dimensions while retaining the optical performance of the original system. However, dispersion effects of the constituent materials often limit the bandwidth of metamaterial and TO structures thus restricting their potential applicability. Nonetheless, with the proper pairing of GRIN profile and lens geometry to a given material system, chromatic aberrations can be minimized. To aid in the GRIN construction, we employ advanced multi-objective optimization algorithms which allow the designer to explicitly view the trade-offs between all design objectives such as RMS spot size, field-of-view (FOV), lens thickness, 𝛥𝑛, and focal drift due to chromatic aberrations. We present an overview of our TO-enabled GRIN lens design process and analysis techniques while demonstrating designs which minimize the presence of mono- and poly-chromatic aberrations and discuss their requisite material systems.

  17. Design and development of a laminated glass-plastic Fresnel lens for point focus photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    Matalon, L. A.

    1982-08-01

    The design and development of a laminated glass-plastic Fresnel lens for point focus photovoltaic systems use is described. The objective of this development was to examine the feasibility of producing lenses with a cost effectiveness superior to that of lenses made by casting of acrylic. The procedure used in executing this development, the method used in cost effectiveness evaluation, results obtained and recommendations for further work are presented.

  18. Zoom lens design for 10.2-megapixel APS-C digital SLR cameras.

    Science.gov (United States)

    Sun, Wen-Shing; Chu, Pu-Yi; Tien, Chuen-Lin; Chung, Meng-Feng

    2017-01-20

    A zoom lens design for a 10.2-megapixel digital single-lens reflex (SLR) camera with an advanced photo system type-C (APS-C) CCD image sensor is presented. The proposed zoom lens design consists of four groups of 3× zoom lenses with a focal length range of 17-51 mm. In the optimization process, 107 kinds of Schott glass combined with 26 kinds of plastic materials, as listed in Code V, are used. The best combination of glass and plastic materials is found based on the nd-Vd diagram. The modulation transfer function (MTF) was greater than 0.509 at 42  lp/mm, the lateral chromatic aberration was less than 5 μm, the optical distortion was less than 1.97%, and the relative illumination was greater than 80.05%. We also performed the tolerance analysis with the 2σ (97.7%) position selected and given tolerance tables and results for three zooming positions, which made the design more practical for manufacturing.

  19. Design of a compact focusing lens system with short acceleration tube at 300 kV

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Yasuyuki, E-mail: ishii.yasuyuki@jaea.go.jp [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Ohkubo, Takeru; Kojima, Takuji; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-10-15

    A compact focusing lens system with high demagnification over 1500 was designed to form an ion nanobeam with 346 keV energy by adding a short distance acceleration tube for beam acceleration and focusing downstream of the existing double acceleration lens system. The demagnification, focusing points and aberrations of the acceleration tube were studied using beam trajectory calculation. The acceleration tube was designed to have a length of 140 mm and a demagnification of 2 at its acceleration tube voltage of 300 kV, which resulted in a new compact focusing lens system with a total length of about 640 mm. In addition, the maximum voltage and electric-field of the acceleration tube were confirmed experimentally on the built device to be 300 kV and 30 kV/cm, respectively. The final beam size formed by the system was estimated to be 130 nm in diameter using the design parameters. The result suggests that an ion nanobeam of 346 keV can be formed by an apparatus having the reasonable length of 2 m, which permits us to develop a system for 1 MV by elongating its tube length.

  20. Design of a solar-blind ultraviolet zoom lens in corona detection

    Science.gov (United States)

    Kang, Sirui; Fan, Wenwen; Chen, Yu

    2016-11-01

    Based on the requirements of corona detection on searching targets with large field of view and detecting objects with small field of view, a refractive zoom optical system using mechanical compensation technology, which operates at 0.24μm~0.28μm wavelength ,is designed with aspherical surfaces. S8844-0909 ultraviolet CCD is selected as a sensor with pixel size 24μm×24μm. The zooming region is 35mm~70mm with F number of 3.5 and the corresponding field of view of 7°~14°.The zoom lens consists of seven lenses with two aspherical surfaces, so it has the advantages of compact size and simple structure. The results show that in full zooming range, the MTF values over all fields of view are above 0.8 at cut-off frequency 21lp/mm. The distortion is less than 5%.The zoom lens system has good image quality and stable image plane, which meets the overall design requirements of the optical system. Keywords: Corona detection, Zoom lens, Aspheric surface

  1. Design of compact freeform lens for application specific Light-Emitting Diode packaging.

    Science.gov (United States)

    Wang, Kai; Chen, Fei; Liu, Zongyuan; Luo, Xiaobing; Liu, Sheng

    2010-01-18

    Application specific LED packaging (ASLP) is an emerging technology for high performance LED lighting. We introduced a practical design method of compact freeform lens for extended sources used in ASLP. A new ASLP for road lighting was successfully obtained by integrating a polycarbonate compact freeform lens of small form factor with traditional LED packaging. Optical performance of the ASLP was investigated by both numerical simulation based on Monte Carlo ray tracing method and experiments. Results demonstrated that, comparing with traditional LED module integrated with secondary optics, the ASLP had advantages of much smaller size in volume (approximately 1/8), higher system lumen efficiency (approximately 8.1%), lower cost and more convenience for customers to design and assembly, enabling possible much wider applications of LED for general road lighting. Tolerance analyses were also conducted. Installation errors of horizontal and vertical deviations had more effects on the shape and uniformity of radiation pattern compared with rotational deviation. The tolerances of horizontal, vertical and rotational deviations of this lens were 0.11 mm, 0.14 mm and 2.4 degrees respectively, which were acceptable in engineering.

  2. Eye models for the prediction of contrast vision in patients with new intraocular lens designs

    Science.gov (United States)

    Piers, Patricia A.; Sverker Norrby, N. E.; Mester, Ulrich

    2004-04-01

    Theoretical calculations of the polychromatic modulation transfer function (MTF) and wave-front aberration were performed with physiological eye models. These eye models have an amount of spherical aberration that is representative of a normal population of pseudophakic eyes implanted with two different types of intraocular lens (IOL) made from high-refractive-index silicone. These theoretical calculations were compared with the measured contrast sensitivity function (CSF) under mesopic lighting conditions and with wave-front aberration (obtained with a Hartmann-Shack wave-front sensor) collected from 37 patients bilaterally implanted with the same types of lens. The relationships between the ocular wave-front aberration and the MTF predicted by the eye models and the CSF and the ocular wave-front aberration measured in eyes implanted with IOLs were investigated. The predicted improvements in MTF and wave-front aberration correlated well with the improvements measured in practice. Physiological eye models are therefore useful tools for IOL design.

  3. Design of thin-film photonic metamaterial L\\"uneburg lens using analytical approach

    CERN Document Server

    Gao, Hanhong; Johnson, Steven G; Barbastathis, George

    2011-01-01

    We design an all-dielectric L\\"uneburg lens as an adiabatic space-variant lattice explicitly accounting for finite film thickness. We describe an all-analytical approach to compensate for the finite height of subwavelength dielectric structures in the pass-band regime. This method calculates the effective refractive index of the infinite-height lattice from effective medium theory, then embeds a medium of the same effective index into a slab waveguide of finite height and uses the waveguide dispersion diagram to calculate a new effective index. The results are compared with the conventional numerical treatment - a direct band diagram calculation, using a modified three-dimensional lattice with the superstrate and substrate included in the cell geometry. We show that the analytical results are in good agreement with the numerical ones, and the performance of the thin-film L\\"uneburg lens is quite different than the estimates obtained assuming infinite height.

  4. Design of Fresnel Lens-Type Multi-Trapping Acoustic Tweezers

    Directory of Open Access Journals (Sweden)

    You-Lin Tu

    2016-11-01

    Full Text Available In this paper, acoustic tweezers which use beam forming performed by a Fresnel zone plate are proposed. The performance has been demonstrated by finite element analysis, including the acoustic intensity, acoustic pressure, acoustic potential energy, gradient force, and particle distribution. The acoustic tweezers use an ultrasound beam produced by a lead zirconate titanate (PZT transducer operating at 2.4 MHz and 100 Vpeak-to-peak in a water medium. The design of the Fresnel lens (zone plate is based on air reflection, acoustic impedance matching, and the Fresnel half-wave band (FHWB theory. This acoustic Fresnel lens can produce gradient force and acoustic potential wells that allow the capture and manipulation of single particles or clusters of particles. Simulation results strongly indicate a good trapping ability, for particles under 150 µm in diameter, in the minimum energy location. This can be useful for cell or microorganism manipulation.

  5. Aspherical lens design using hybrid neural-genetic algorithm of contact lenses.

    Science.gov (United States)

    Yen, Chih-Ta; Ye, Jhe-Wen

    2015-10-01

    The design of complex contact lenses involves numerous uncertain variables. How to help an optical designer to first design the optimal contact lens to reduce discomfort when wearing a pair of glasses is an essential design concern. This study examined the impact of aberrations on contact lenses to optimize a contact lens design for myopic and astigmatic eyes. In general, two aspherical surfaces can be assembled in an optical system to reduce the overall volume size. However, this design reduces the spherical aberration (SA) values at wide contact radii. The proposed optimization algorithm with optical design can be corrected to improve the SA value and, thus, reduce coma aberration (TCO) values and enhance the modulation transfer function (MTF). This means integrating a modified genetic algorithm (GA) with a neural network (NN) to optimize multiple-quality characteristics, namely the SA, TCO, and MTF, of contact lenses. When the proposed optional weight NN-GA is implemented, the weight values of the fitness function can be varied to adjust system performance. The method simplifies the selection of parameters in the optimization of optical systems. Compared with the traditional CODE V built-in optimal scheme, the proposed scheme is more flexible and intuitive to improve SA, TCO, and MTF values by 50.03%, 45.78%, and 24.7%, respectively.

  6. Concepts of the mosaic array of numerous ultra-small lens (MANUL) design

    Science.gov (United States)

    Pál, A.; Mészáros, L.

    2016-08-01

    In order to provide a continuous, multi-color time-domain surveying of the brightest regime of the naked-eye optical sky, we designed the Mosaic Array of Numerous Ultrasmall Lens (MANUL). This device is a palm-sized "astronomical observatory," featuring optics, filters and all necessary electronics (including a TCP/IP-based downlink), all are mounted on 2-inch printed circuit boards. Based on these units, a modular and mosaic arrangement of CMOS imaging sensors with an effective resolution of 1'/pixel can be built. Here we introduce the main design concepts, the early prototyping and the results of the preliminary photometric quality analysis of this initiative.

  7. Posterior capsular opacification and intraocular lens decentration. Part I: Comparison of various posterior chamber lens designs implanted in the rabbit model.

    Science.gov (United States)

    Hansen, S O; Solomon, K D; McKnight, G T; Wilbrandt, T H; Gwin, T D; O'Morchoe, D J; Tetz, M R; Apple, D J

    1988-11-01

    Experimental phacoemulsification procedures were performed in 54 Rex rabbits. In 96 eyes, posterior chamber intraocular lenses (IOLs) were implanted in the capsular sac, and 12 eyes served as controls with no lens implantation. The IOLs were divided into eight groups consisting of both one-piece and three-piece styles with various optic designs. Each lens was evaluated for the relative effect on posterior capsular opacification (PCO) and optic decentration, two of the most common complications of modern cataract surgery and IOL implantation. Optics with a convex-anterior, plano-posterior design (the type of IOL optic most frequently implanted today) had the highest incidence of PCO. With capsular fixated IOLs, the features that have a statistically significant impact on reducing PCO include (1) one-piece, all-polymethylmethacrylate (PMMA) IOL styles, (2) a biconvex or posterior convex optic design, and (3) angulated loops. Lens decentration was not affected by the optic design, but statistical analysis showed that one-piece, all-PMMA IOL construction provided the most consistent centration.

  8. Improved design of three-dimensional lens for low concentrator PV modules; Teishukogata taiyo denchiyo sanjigen lens no koseinoka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Goma, S.; Yoshioka, K.; Saito, T. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan)

    1997-11-25

    Attention is paid to reduction in area required for solar cells by solar concentration as a means of solving cost limits of solar cells and unstable supply of Si materials. Low concentration solar cells are effective from the aspects of utilization of scattered light and unnecessary ray tracing. The optical concentration ratio was calculated of three-dimensional lens having design values of various north/south and east/west direction allowable incidence half angles. The three-dimensional lens are designed by cutting a rectangular parallelepiped by the two-dimensional composite elliptical plane designed by various allowable incidence half angles from two directions of north/south and east/west. Using Perez`s sky solar radiation models and meteorological data HASP, calculated were the annual accumulated global radiation ratio on an inclined surface and the optical efficiency. Calculated were the solar cell area ratio and solar concentration area ratio of the concentration type to obtain solar radiation the same as that of the planar type. From the optimization calculation, it was found that lens are optimal which have design values of north/south and east/west direction allowable incidence half angles of 30-70deg. The solar cell area ratio is 57% and the solar concentration area ratio is 1.2 times. It was found that by making the module area 1.2 times, more than 40% of the solar cells used can be saved. 5 refs., 8 figs.

  9. The study about forming high-precision optical lens minimalized sinuous error structures for designed surface

    Science.gov (United States)

    Katahira, Yu; Fukuta, Masahiko; Katsuki, Masahide; Momochi, Takeshi; Yamamoto, Yoshihiro

    2016-09-01

    Recently, it has been required to improve qualities of aspherical lenses mounted on camera units. Optical lenses in highvolume production generally are applied with molding process using cemented carbide or Ni-P coated steel, which can be selected from lens material such as glass and plastic. Additionally it can be obtained high quality of the cut or ground surface on mold due to developments of different mold product technologies. As results, it can be less than 100nmPV as form-error and 1nmRa as surface roughness in molds. Furthermore it comes to need higher quality, not only formerror( PV) and surface roughness(Ra) but also other surface characteristics. For instance, it can be caused distorted shapes at imaging by middle spatial frequency undulations on the lens surface. In this study, we made focus on several types of sinuous structures, which can be classified into form errors for designed surface and deteriorate optical system performances. And it was obtained mold product processes minimalizing undulations on the surface. In the report, it was mentioned about the analyzing process by using PSD so as to evaluate micro undulations on the machined surface quantitatively. In addition, it was mentioned that the grinding process with circumferential velocity control was effective for large aperture lenses fabrication and could minimalize undulations appeared on outer area of the machined surface, and mentioned about the optical glass lens molding process by using the high precision press machine.

  10. Miniature objective lens for array digital pathology: design improvement based on clinical evaluation

    Science.gov (United States)

    McCall, Brian; Pierce, Mark; Graviss, Edward A.; Richards-Kortum, Rebecca R.; Tkaczyk, Tomasz S.

    2016-03-01

    A miniature objective designed for digital detection of Mycobacterium tuberculosis (MTB) was evaluated for diagnostic accuracy. The objective was designed for array microscopy, but fabricated and evaluated at this stage of development as a single objective. The counts and diagnoses of patient samples were directly compared for digital detection and standard microscopy. The results were found to be correlated and highly concordant. The evaluation of this lens by direct comparison to standard fluorescence sputum smear microscopy presented unique challenges and led to some new insights in the role played by the system parameters of the microscope. The design parameters and how they were developed are reviewed in light of these results. New system parameters are proposed with the goal of easing the challenges of evaluating the miniature objective and maintaining the optical performance that produced the agreeable results presented without over-optimizing. A new design is presented that meets and exceeds these criteria.

  11. [Lens platform].

    Science.gov (United States)

    Łukaszewska-Smyk, Agnieszka; Kałuzny, Józef

    2010-01-01

    The lens platform defines lens structure and lens material. Evolution of lens comprises change in their shape, angulation of haptens and transition of three-piece lens into one-piece lens. The lens fall into two categories: rigid (PMMA) and soft (siliconic, acrylic, colameric). The main lens maaterials are polymers (hydrophilic and hydrophobic). The lens platform has an effect on biocompatibility, bioadhesion, stability of lens in capsule, degree of PCO evolution and sensitiveness to laser damages.

  12. Design and development of a high-concentration and high-efficiency photovoltaic concentrator using a curved Fresnel lens

    Energy Technology Data Exchange (ETDEWEB)

    Scharlack, R.S.; Moffat, A.

    1983-08-01

    Thermo Electron has designed a high concentration photovoltaic module that uses a domed, point-focus Fresnel lens. Their design, design optimization process, and results from lens and receiver tests are described in this report. A complete module has not been fabricated and probably will not be fabricated in the future; however, Thermo Electron's optical design, analysis, and testing of both secondary optical units and domed Fresnel lenses have made a significant contribution to our project. Tooling errors prevented the lens from reaching its potential efficiency by the end of the contract, and resolution of these tooling problems is currently being attempted with a follow-on contract, No. 68-9463.

  13. Rapid cooled lens cell

    Science.gov (United States)

    Stubbs, David M.; Hsu, Ike C.

    1991-12-01

    This paper describes the optomechanical design, thermal analysis, fabrication, and test evaluation processes followed in developing a rapid cooled, infrared lens cell. Thermal analysis was the key engineering discipline exercised in the design phase. The effect of thermal stress on the lens, induced by rapid cooling of the lens cell, was investigated. Features of this lens cell that minimized the thermal stress will be discussed in a dedicated section. The results of thermal analysis on the selected lens cell design and the selection of the flow channel design in the heat exchanger will be discussed. Throughout the paper engineering drawings, illustrations, analytical results, and photographs of actual hardware are presented.

  14. Circuit design for the retina-like image sensor based on space-variant lens array

    Science.gov (United States)

    Gao, Hongxun; Hao, Qun; Jin, Xuefeng; Cao, Jie; Liu, Yue; Song, Yong; Fan, Fan

    2013-12-01

    Retina-like image sensor is based on the non-uniformity of the human eyes and the log-polar coordinate theory. It has advantages of high-quality data compression and redundant information elimination. However, retina-like image sensors based on the CMOS craft have drawbacks such as high cost, low sensitivity and signal outputting efficiency and updating inconvenience. Therefore, this paper proposes a retina-like image sensor based on space-variant lens array, focusing on the circuit design to provide circuit support to the whole system. The circuit includes the following parts: (1) A photo-detector array with a lens array to convert optical signals to electrical signals; (2) a strobe circuit for time-gating of the pixels and parallel paths for high-speed transmission of the data; (3) a high-precision digital potentiometer for the I-V conversion, ratio normalization and sensitivity adjustment, a programmable gain amplifier for automatic generation control(AGC), and a A/D converter for the A/D conversion in every path; (4) the digital data is displayed on LCD and stored temporarily in DDR2 SDRAM; (5) a USB port to transfer the data to PC; (6) the whole system is controlled by FPGA. This circuit has advantages as lower cost, larger pixels, updating convenience and higher signal outputting efficiency. Experiments have proved that the grayscale output of every pixel basically matches the target and a non-uniform image of the target is ideally achieved in real time. The circuit can provide adequate technical support to retina-like image sensors based on space-variant lens array.

  15. The rectenna design on contact lens for wireless powering of the active intraocular pressure monitoring system.

    Science.gov (United States)

    Cheng, H W; Jeng, B M; Chen, C Y; Huang, H Y; Chiou, J C; Luo, C H

    2013-01-01

    This paper proposed a wireless power harvesting system with micro-electro-mechanical-systems (MEMS) fabrication for noninvasive intraocular pressure (IOP) measurement on soft contact lens substructure. The power harvesting IC consists of a loop antenna, an impedance matching network and a rectifier. The proposed IC has been designed and fabricated by CMOS 0.18 um process that operates at the ISM band of 5.8 GHz. The antenna and the power harvesting IC would be bonded together by using flip chip bonding technologies without extra wire interference. The circuit utilized an impedance transformation circuit to boost the input RF signal that improves the circuit performance. The proposed design achieves an RF-to-DC conversion efficiency of 35% at 5.8 GHz.

  16. [System design of open-path natural gas leakage detection based on Fresnel lens].

    Science.gov (United States)

    Xia, Hui; Liu, Wen-Qing; Zhang, Yu-Jun; Kan, Rui-Feng; Cui, Yi-Ben; Wang, Min; He, Ying; Cui, Xiao-Juan; Ruan, Jun; Geng, Hui

    2009-03-01

    Based on the technology of tunable diode laser absorption spectroscopy (TDLAS) in conjunction with second harmonic wave detection, a long open-path TDLAS system using a 1.65 microm InGaAsP distributed feedback laser was developed, which is used for detecting pipeline leakage. In this system, a high cost performance Fresnel lens is used as the receiving optical system, which receives the laser-beam reflected by a solid corner cube reflector, and focuses the receiving laser-beam to the InGaAs detector. At the same time, the influences of the concentration to the fluctuation of light intensity were taken into account in the process of measurement, and were eliminated by the method of normalized light intensity. As a result, the measurement error caused by the fluctuation of light intensity was made less than 1%. The experiment of natural gas leakage detection was simulated, and the detection sensitivity is 0.1 x 10(-6) (ratio by volume) with a total path of 320 m. According to the receiving light efficiency of the optical system and the detectable minimum light intensity of the detector, the detectable maximal optical path of the system was counted to be 2 000 m. The results of experiment show that it is a feasible design to use the Fresnel lens as the receiving optical system and can satisfy the demand of the leakage detection of natural gas.

  17. Design of an efficient Fresnel-type lens utilizing double total internal reflection for solar energy collection.

    Science.gov (United States)

    Wallhead, Ian; Jiménez, Teresa Molina; Ortiz, Jose Vicente García; Toledo, Ignacio Gonzalez; Toledo, Cristóbal Gonzalez

    2012-11-05

    A novel of Fresnel-type lens for use as a solar collector has been designed which utilizes double total internal reflection (D-TIR) to optimize collection efficiency for high numerical aperture lenses (in the region of 0.3 to 0.6 NA). Results show that, depending on the numerical aperture and the size of the receiver, a collection efficiency theoretical improvement on the order of 20% can be expected with this new design compared with that of a conventional Fresnel lens.

  18. Design and construction of an electrostatic quadrupole doublet lens for nuclear microprobe application

    Science.gov (United States)

    Manuel, Jack E.; Szilasi, Szabolcs Z.; Phillips, Dustin; Dymnikov, Alexander D.; Reinert, Tilo; Rout, Bibhudutta; Glass, Gary A.

    2017-08-01

    An electrostatic quadrupole doublet lens system has been designed and constructed to provide strong, mass-independent focusing of 1-3 MeV ions to a 1 μm2 spot size. The electrostatic doublet consists of four sets of gold electrodes deposited on quartz rods that are positioned in a precision machined rigid frame. The 38 mm electrodes are fixed in a quadrupole doublet arrangement having a bore diameter of 6.35 mm. The coating process allows uniform, 360° coverage with minimal edge defects. Determined via optical interferometry, typical surface roughness is 6 nm peak to valley. Radial and coaxial alignment of the electrodes within the frame is accomplished by using a combination of rigid and adjustable mechanical supports. Axial alignment along the ion beam is accomplished via external manipulators. COMSOL Multiphysics® v5.2 and Propagate Rays and Aberrations by Matrices (PRAM) were used to simulate ion trajectories through the system.

  19. Comparison of different Kerr-lens mode locking laser design techniques

    Science.gov (United States)

    Moreno-Larios, José Agustín.; Rosete-Aguilar, Martha; Garduño-Mejía, Jesús

    2016-04-01

    Three numerical methods for the design of Kerr Lens Mode-Locking (KLML) ultrashort pulse cavities that use a solid state Brewster-cut nonlinear gain medium are compared. The nonlinear medium is modeled first deploying a matrix approximation that considers non-coupled (tangential analysis is independent of sagittal analysis) Kerr and thermal self-focusing; and second with a differential equation that relates the real and imaginary parts of the inverse of the complex Gaussian beam parameter. The third comparison is against a matrix analysis method that considers the coupling between the sagittal and tangential modes inside the nonlinear medium in order to determine the impact of this effect. The three methods search the self-consistency condition for the complex beam parameter and the results are compared.

  20. Micro-lens array design on a flexible light-emitting diode package for indoor lighting.

    Science.gov (United States)

    Lee, Hsiao-Wen; Lin, Bor-Shyh

    2015-10-01

    An advanced, ultra-thin, flexible LED (FLED) package technique is first proposed in this study, where a polyimide substrate was used as the lead frame package material due to its physical stability in thermal processing. The experimental results showed that the thickness of the mockup sample measured by a vernier caliper was 260 μm and 35% thinner than the Panasonic organic LED lighting panel announced on 4 March 2014 in Tokyo. Moreover, the flexible angle of the ultra-thin LED package was 200.54° when it surrounded a disk with a 1 cm radius. A design of a micro-lens array manufactured by silicone molding on the FLED is also proposed in this study. Finally, different types of micro-lenses were applied to different lighting regions to investigate their lighting effects.

  1. Design of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp

    Science.gov (United States)

    Wang, Hong; Li, Xiufeng; Ge, Peng

    2017-02-01

    We propose a design method of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp. The TIR freeform surface controls the edge rays of the LED source. It totally reflects the edge rays and makes them emit from the top surface of the lens. And the middle rays of the LED source go through the refractive surface and reach the measured plane. We simulate the model by Monte Carlo method. Simulation results show that the front fog lamp system can satisfy the requirement of ECE R19 Rev7. The light control efficiency can reach up to 76%.

  2. Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

    Directory of Open Access Journals (Sweden)

    Packer M

    2016-06-01

    Full Text Available Mark Packer Mark Packer MD Consulting, Inc., Boulder, CO, USA Abstract: The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL, and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.. Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594=1.33; P=0.18. The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks

  3. Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

    Science.gov (United States)

    Packer, Mark

    2016-01-01

    The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.). Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594)=1.33; P=0.18). The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks. PMID:27354760

  4. Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens.

    Science.gov (United States)

    Packer, Mark

    2016-01-01

    The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.). Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594)=1.33; P=0.18). The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks.

  5. Design of anisotropic focusing metasurface and its application for high-gain lens antenna

    Science.gov (United States)

    Guo, Wenlong; Wang, Guangming; Li, Haipeng; Li, Tangjing; Ge, Qichao; Zhuang, Yaqiang

    2017-03-01

    In this paper, we propose an anisotropic focusing metasurface with function of focusing orthogonally polarized waves in refraction and reflection modes respectively. By employing four layered metallic patches spaced by triple layered dielectric spacers, an anisotropic phase element is designed with capability of transmitting x-polarized waves but reflecting y-polarized beams efficiently. Composed of 21 × 21 cells and with size of 105 × 105 mm2, a focusing metasurface operating at 15 GHz is designed with the same focal length of 30 mm for x- and y-polarized waves. By setting a patch antenna at the focal point, the metasurface sample is employed to enhance gain of the radiation source. For verification, the metasurface sample is fabricated and measured. The antenna performance, in terms of realized boresight gain and operating bandwidth under x- and y-polarized waves illumination, is presented. Results show that the 1 dB gain bandwidths are respectively from 14.7 to 15.3 GHz and 14.7 to 15.2 GHz, and the gain are enhanced by 14.1 dB, 15.1 dB in refraction and reflection modes when the metasurface is impinged by x- and y-polarized spherical waves. The proposed anisotropic metasurface may afford an alternative for designing anisotropic planar lens or high-gain antenna.

  6. [Femtosecond laser-assisted lens surgery depending on interface design and laser pulse energy: results of the first 200 cases].

    Science.gov (United States)

    Mayer, W J; Klaproth, O K; Ostovic, M; Hengerer, F H; Kohnen, T

    2014-12-01

    This study was designed to evaluate the effectiveness and safety of femtosecond laser-assisted lens surgery depending on interface design and laser pulse energy settings. In this non-randomized, consecutive case series200 eyes underwent femtosecond laser-assisted (LenSx, Alcon) lens surgery between November 2012 and June 2013. Group 1 consisted of 85 eyes with 60 cataracts and 25 refractive lens exchanges (RLE) which were treated with a curved direct contact interface, and group 2 consisting of 115 eyes with 72 cataracts and 43 RLEs treated with a modified interface using an additional soft contact lens (SoftFit™, Alcon) between the corneal surface and the interface. The degree of opacity of the lens in cataract eyes was measured with a Scheimpflug camera. Afterwards, phacoemulsification was performed with intraocular lens (IOL) implantation in all eyes. Primary endpoints were the effective phacoemulsification time (EPT), the average laser treatment time and the occurrence of intraoperative complications. The mean EPT in group 1 was 1.62 ± 1.12 s (cataract 1.94 ± 1.31 s, RLE 1.29 ± 1.01 s) and in group 2 the mean EPT was 1.66 ± 0.92 s (cataract 1.98 ± 1.28 s, RLE 1.33 ± 1.22 s, p = 0.32 between groups). The laser treatment lasted on average 48.90 ± 2.45 s (group 1) and 49.70 ± 2.87 s (group 2) with an average lens fragmentation thickness of 3401.48 ± 401.12 µm (all groups). In four cases of group 1, a second applanation of the interface was necessary. Furthermore, one anterior capsule tear, 39 cases of intraoperative wrinkling of the corneal surface and 21 cases in which the corneal incision had to be opened manually were documented in group 1. In group 2 no second applanation of the interface, no anterior capsule tears and no corneal wrinkling but 9 cases with a manual opening of corneal incisions were documented (p interface and reduced laser pulse energy.

  7. Clinical Trials of Exterior Non Implanted Interference-Based Extended Depth of Focus Intra Ocular Lens Design

    Directory of Open Access Journals (Sweden)

    Zeev Zalevsky

    2014-10-01

    Full Text Available In this paper, we present the clinical trials performed with intra ocular lens (IOL design, realizing an interference-based extended depth of focus concept, with an external glass plate. The purpose of such extended depth of focus-based IOL design is to prevent cataract patients from needing to use different types of glasses (for reading and for distance vision after undergoing surgery.

  8. Design, simulation, and measurement of LED reading lamp with non-axisymmetrical reflector and freeform lens

    Science.gov (United States)

    Chao, Wei-Yang; Chen, Yi-Yung; Whang, Allen Jong-Woei; Lu, Ming-Jun

    2011-10-01

    With the rapid development of various types of digi-readers, such as i-Pad, Kindle, and so on, non-self-luminous type has an advantage, low power consumption. This type of digi-reader reflects the surrounding light to display so it is no good at all to read under dim environment. In this paper, we design a LED lamp for a square lighted range with low power consumption. The e-book is about 12cm x 9cm, the total flux of LED is 3 Lm, and the LED lamp is put on the upper brink of the panel with 6cm height and 45 degree tilted angle. For redistributing the energy, the LED lamp has a freeform lens to control the light of small view angle and a non-axisymmetrical reflector to control the light of large view angle and create a rectangular-like spot. In accordance with the measurement data, the proposed optical structure achieves that the power consumption of LED light source is only 90mW, the average illumination is about 200 Lux, the uniformity of illumination is over 0.7, and the spot is rectangular-like with precise light/dark cutting-off line. Our designed optical structure significantly increases the efficiency of light using and meets the environmental goal of low energy consumption.

  9. Advanced gradient-index lens design tools to maximize system performance and reduce SWaP

    Science.gov (United States)

    Campbell, Sawyer D.; Nagar, Jogender; Brocker, Donovan E.; Easum, John A.; Turpin, Jeremiah P.; Werner, Douglas H.

    2016-05-01

    GRadient-INdex (GRIN) lenses have long been of interest due to their potential for providing levels of performance unachievable with traditional homogeneous lenses. While historically limited by a lack of suitable materials, rapid advancements in manufacturing techniques, including 3D printing, have recently kindled a renewed interest in GRIN optics. Further increasing the desire for GRIN devices has been the advent of Transformation Optics (TO), which provides the mathematical framework for representing the behavior of electromagnetic radiation in a given geometry by "transforming" it to an alternative, usually more desirable, geometry through an appropriate mapping of the constituent material parameters. Using TO, aspherical lenses can be transformed to simpler spherical and flat geometries or even rotationally-asymmetric shapes which result in true 3D GRIN profiles. Meanwhile, there is a critical lack of suitable design tools which can effectively evaluate the optical wave propagation through 3D GRIN profiles produced by TO. Current modeling software packages for optical lens systems also lack advanced multi-objective global optimization capability which allows the user to explicitly view the trade-offs between all design objectives such as focus quality, FOV, ▵nand focal drift due to chromatic aberrations. When coupled with advanced design methodologies such as TO, wavefront matching (WFM), and analytical achromatic GRIN theory, these tools provide a powerful framework for maximizing SWaP (Size, Weight and Power) reduction in GRIN-enabled optical systems. We provide an overview of our advanced GRIN design tools and examples which minimize the presence of mono- and polychromatic aberrations in the context of reducing SWaP.

  10. Automated indexing of Laue images from polycrystalline materials

    Energy Technology Data Exchange (ETDEWEB)

    Chung, J.S.; Ice, G.E. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1998-12-31

    Third generation hard x-ray synchrotron sources and new x-ray optics have revolutionized x-ray microbeams. Now intense sub-micron x-ray beams are routinely available for x-ray diffraction measurement. An important application of sub-micron x-ray beams is analyzing polycrystalline material by measuring the diffraction of individual grains. For these measurements, conventional analysis methods will not work. The most suitable method for microdiffraction on polycrystalline samples is taking broad-bandpass or white-beam Laue images. With this method, the crystal orientation and non-isostatic strain can be measured rapidly without rotation of sample or detector. The essential step is indexing the reflections from more than one grain. An algorithm has recently been developed to index broad bandpass Laue images from multi-grain samples. For a single grain, a unique set of indices is found by comparing measured angles between Laue reflections and angles between possible indices derived from the x-ray energy bandpass and the scattering angle 2 theta. This method has been extended to multigrain diffraction by successively indexing points not recognized in preceding indexing iterations. This automated indexing method can be used in a wide range of applications.

  11. Fitting an MSD (mini scleral design) rigid contact lens in advanced keratoconus with INTACS.

    Science.gov (United States)

    Dalton, Kristine; Sorbara, Luigina

    2011-12-01

    Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients.

  12. Design and fabrication of an elliptical micro-lens array with grating for laser safety

    Science.gov (United States)

    Li, L. H.; Wu, B. Q.; Chan, C. Y.; Lee, W. B.; Dong, L. H.

    2015-10-01

    With the enormous expansion of laser usage in medicine, industry and research, all facilities must formulate and adhere to specific safety methods that appropriately address user protection. The protective ellipticalal microstructure with grating is a novel technology which can provide the principal means of ensuring against ocular injury, and must be worn at all times during laser operation. On the basis of Fresnel's law and the diffractive law, Solidworks and Lighttools software are applied to design the elliptical micro-lens array and correspondent grating. The height of the microstructure is 100um and its period is 3mm. The period of grating is 5um. It is shown that the amount of emergent light of a specific wavelength (1064nm) can reflect more than 40° from the incident light through simulation, while the incident light is perpendicular to the microstructure. The fabrication adopts the ultra-precision single point diamond method and injection molding method. However, it is found in the test that the surface roughness has a serious effect on the angle between the emergent and incident light. As a result, the element can reflect the vertical incidence beam into a tilted emergent beam with a certain angular degree , as well as protecting users from laser damage injures.

  13. Study of focusing characteristics of ultrasound for designing acoustic lens in ultrasonic moxibustion device

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Hyun; Song, Sung Jin; Kim, Hak Joon [School of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kim, Ki Bok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2015-04-15

    Traditional moxibustion therapy can cause severe pain and leave scarring burns at the moxibustion site as it relies on the practitioner's subjective and qualitative treatment. Recently, ultrasound therapy has received attention as an alternative to moxibustion therapy owing to its objectiveness and quantitative nature. However, in order to convert ultrasound energy into heat energy, there is a need to precisely understand the ultrasound-focusing characteristics of the acoustic lens. Therefore, in this study, an FEM simulation was performed for acoustic lenses with different geometries a concave lens and zone lens as the geometry critically influences ultrasound focusing. The acoustic pressure field, amplitude, and focal point were also calculated. Furthermore, the performance of the fabricated acoustic lens was verified by a sound pressure measurement experiment.

  14. Business model design through a designer's lens: Translating, transferring and transforming cognitive configurations into action

    NARCIS (Netherlands)

    Simonse, W.L.; Badke-Schaub, P.G.

    2015-01-01

    Strategic managers are challenged to take advantage of digitalisation opportunities related to services of social media and web 2.0 technologies. Business innovations such as crowd sourcing platforms require a new way of integrating business to technology, articulated in a new business model designs

  15. Ultra-wide to mid-wide angle 3X zoom and focus adjustable lens design for industrial video endoscope

    Science.gov (United States)

    Yang, Dongmin

    2012-11-01

    Optical zoom lens design for industrial video endoscope faces tremendous challenges in stringent compactness requirement in both diameter and rigid length dimensions, as well as harsh environmental requirements such as high working temperature. Industrial video endoscope with optical zoom capability is increasingly demanded by market yet nowadays no such product has been commercialized. Once it succeeds, it will provide huge benefits to customers in improvement of remote visual inspection work quality and productivity. A 3X continuous optical zoom lens design with short focal length is presented in this paper. It is capable to change Field of View from ultra-wide angle as 120degrees to mid-wide angle as 40degrees. Focus distance change is from infinity to as close as 5mm. The whole lens train has a maximum diameter of 3.0mm, and overall length of 8.7mm, which makes it practical to be integrated into a 6mm industrial video endoscope. Image quality in terms of contrast and resolution exceeds today's existing commercial 6mm industrial video endoscopes. The design has also considered cost and product ruggedness requests.

  16. Manufacturing of advanced bent crystals for Laue Optics for Gamma ObservationS (LOGOS)

    Energy Technology Data Exchange (ETDEWEB)

    Mazzolari, Andrea, E-mail: mazzolari@fe.infn.it [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1/c, 44122 Ferrara (Italy); INFN, Section of Ferrara (Italy); Camattari, Riccardo; Bellucci, Valerio; Paternò, Gianfranco [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1/c, 44122 Ferrara (Italy); INFN, Section of Ferrara (Italy); Scian, Carlo; Mattei, Giovanni [University of Padova, Department of Physics and Astronomy Galileo Galilei (Italy); Guidi, Vincenzo [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1/c, 44122 Ferrara (Italy); INFN, Section of Ferrara (Italy)

    2015-07-15

    X- and γ-ray detection is currently a hot topic for a wide scientific community, spanning from astrophysics to nuclear medicine. However, lack of optics capable of focusing photons of energies in the energy range 0.1–1 MeV leaves the photon detection to a direct-view approach, resulting in a limited efficiency and resolution. The main scope of the INFN-LOGOS project is the development of technologies that enable manufacturing highly performing optical elements to be employed in the realization of hard X-ray lenses. Such lenses, typically named Laue lenses, consist of an ensemble of crystals disposed in concentric rings in order to diffract the incident radiation towards the focus of the lens, where a detector is placed. In particular, the INFN-LOGOS project aims at the realization of intrinsically bent silicon and germanium crystals exploiting the quasi-mosaic effect for focusing hard X-rays. Crystal manufacturing relies on a proper revisitation of techniques typically employed in silicon micromachining, such as thin film deposition and patterning or ion implantation.

  17. Design and fabrication of one-dimensional focusing X-ray compound lens with Al material

    Institute of Scientific and Technical Information of China (English)

    Zichun Le; Ming Zhang; Jingqiu Liang; Wen Dong; Kai Liu; Bisheng Quan

    2006-01-01

    @@ A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced,the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach.A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented.In addition,a two-time coating method is used to improve the numerical apertures of the compound lenses.Furthermore,the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.

  18. 一种LED均匀照明的透镜设计%A Lens Design for LED Uniform Illumination

    Institute of Scientific and Technical Information of China (English)

    王晶; 张宁; 徐熙平; 乔杨

    2015-01-01

    由于LED发射光强的逐渐提高,许多照明系统使用单颗LED作为光源就可以满足不同场合的需求。通过对LED的发光特性的分析,提出了一种以单颗LED作为光源的均匀照明透镜的设计。首先由Snell定律和能量守恒定律构建出满足设计条件的透镜的数学方程,运用MATLAB进行编程解出该方程,再使用Pro/E对求解出的坐标点进行拟合来得到透镜模型,最后用TracePro将得到的透镜模型进行光线追击,通过得到的照度图可知最终达到在规定区域内均匀照明的需求。%With the increasing of emission intensity of LED, illumination system with a single LED light source can meet requirements in many fields. According to the characteristics of LED source, a method of lens design of LED uniform illumination was proposed. At first,a lens design equation by Snell's law and the law of conservation of ener-gy was formulated;and the result of the equation was solved by MATLAB. Then the profile curves were acquired by curve fitting of the coordinate spots with software Pro/E;so the lens model could be got. At last,the lens model was introduced into TracePro and rays were traced. Finally the uniform illumination at target area was obtained.

  19. Designing null phase screens to test a fast plano-convex aspheric lens

    Science.gov (United States)

    DelOlmo-Márquez, Jesús; Castán-Ricaño, Diana; Avendaño-Alejo, Maximino; Díaz-Uribe, Rufino

    2015-08-01

    We have obtained a formula to represent the wavefront produced by a plano-convex aspheric lens with symmetry of revolution considering a plane wavefront propagating parallel to the optical axis and impinging on the refracting surface, it is called a zero-distance phase front, being it the first wavefront to be out of the optical system. Using a concept of differential geometry called parallel curves it is possible to obtain an analytic formula to represent the wavefront propagated at arbitrary distances through the optical axis. In order to evaluate qualitatively a plano-convex aspheric lens, we have modified slightly an interferometer Tywman-Green as follow: In the reference beam we use a plane mirror and the beam of test we have used a spatial light modulator (SLM) to compensate the phase produced by the lens under test. It will be called a null phase interferometer. The main idea is to recombine both wavefronts in order to get a null interferogram, otherwise we will associate the patterns of the interferogram to deformations of the lens under test. The null phase screens are formed with concentric circumferences assuming different gray levels printed on SLM.

  20. Bragg-von Laue diffraction generalized to twisted X-rays.

    Science.gov (United States)

    Jüstel, Dominik; Friesecke, Gero; James, Richard D

    2016-03-01

    A pervasive limitation of nearly all practical X-ray methods for the determination of the atomic scale structure of matter is the need to crystallize the molecule, compound or alloy in a sufficiently large (∼ 10 × 10 × 10 µm) periodic array. In this paper an X-ray method applicable to structure determination of some important noncrystalline structures is proposed. It is designed according to a strict mathematical analog of von Laue's method, but replacing the translation group by another symmetry group, and simultaneously replacing plane waves by different exact closed-form solutions of Maxwell's equations. Details are presented for helical structures like carbon nanotubes or filamentous viruses. In computer simulations the accuracy of the determination of structure is shown to be comparable to the periodic case.

  1. A Two-Stage Taguchi Design ExampleImage Quality Promotion in Miniature Camera/Cell-Phone Lens

    Directory of Open Access Journals (Sweden)

    Luke K. Wang

    2012-07-01

    Full Text Available A simple, practical manufacturing process, integrating manufacturing capability-oriented design (MCOD philosophy and Taguchi’s method, is presented to tackle the high resolution miniature camera/cell phone lens issues at the manufacturing phase. Meanwhile, we also use optical software to create an analytical simulation model to investigate the quality characteristics due to lens’ thickness, eccentricity, surface profile, and air lens’ gap; a single quality characteristics expressed in terms of modulation transfer function (MTF is defined. Optimal combination of process parameters in experimental scenario using Taguchi’s method is performed, and the results are judged and analyzed by the indices of signal-to-noise ratio (S/N and the analysis of variance (ANOVA. The key idea of the two-stage design is to utilize optical software to conduct the sensitivity analysis of MTF first; an analytical model, dependent on actual process parameters at manufacturing stage, is constructed next; and finally by substituting these outputs from the analytical model back to the optical software to verify the design criterion and do the modifications. By minimizing both the theoretical errors at design stage and the complexity in the manufacturing process, we are able to seeking for the most economical solution, simultaneously attain the optimal/suboptimal combination of process parameters or control factors in lens manufacturing issue.

  2. Design of object surveillance system based on enhanced fish-eye lens

    Institute of Scientific and Technical Information of China (English)

    Jianhui Wu; Kuntao Yang; Qiaolian Xiang; Nanyang Zhang

    2009-01-01

    A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor (DSP). The improved fish-eye lens images an ellipse picture on the charge-coupled device (CCD) surface, which increases both the utilization rate of the 4:3 rectangular CCD and the imaging resolution, and remains the view angle of 183°. The algorithm of auto-adapted renewal background subtraction (ARBS) is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies en-vironments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.

  3. Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

    OpenAIRE

    Packer M

    2016-01-01

    Mark Packer Mark Packer MD Consulting, Inc., Boulder, CO, USA Abstract: The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS A...

  4. X-ray micro Laue diffraction tomography analysis of a solid oxide fuel cell1

    Science.gov (United States)

    Ferreira Sanchez, Dario; Villanova, Julie; Laurencin, Jérôme; Micha, Jean-Sébastien; Montani, Alexandre; Gergaud, Patrice; Bleuet, Pierre

    2015-01-01

    The relevance of micro Laue diffraction tomography (µ-LT) to investigate heterogeneous polycrystalline materials has been studied. For this purpose, a multiphase solid oxide fuel cell (SOFC) electrode composite made of yttria-stabilized zirconia and nickel oxide phases, with grains of about a few micrometres in size, has been analyzed. In order to calibrate the Laue data and to test the technique’s sensitivity limits, a monocrystalline germanium sample of about 8 × 4 µm in cross-section size has also been studied through µ-LT. The SOFC and germanium Laue diffraction pattern analyses are compared and discussed. The indexing procedure has been successfully applied for the analysis of the germanium Laue data, and the depth-resolved two-dimensional cartographies of the full deviatoric strain tensor components were obtained. The development and application of an original geometrical approach to analyze the SOFC Laue data allowed the authors to resolve grains with sizes of about 3 µm and to identify their individual Laue patterns; by indexing those Laue patterns, the crystalline phases and orientations of most of the grains identified through the geometrical approach could be resolved. PMID:25844076

  5. Challenges, constraints and results of lens design in 8-12micron waveband for bolometer-FPAs having a pixel pitch 12micron

    Science.gov (United States)

    Schuster, Norbert; Franks, John

    2013-06-01

    In the 8-12 micron waveband Focal Plane Arrays (FPA) are available with a pixel pitch of 12 microns or less. High resolution FPAs with VGA, XGA and SXGA resolution should become available at a reasonable price. These will require new lens designs to give the required fields of view. The challenge for the Optical Designer is to design lenses when the pixel pitch of the detector is the same as the wavelength of the light imaged. The lens specification will need to give more thought to the resolution required by the system. A smaller pixel pitch detector defines a requirement for a shorter focal length to give the same field of view. This will have a number of effects upon the lens design. Geometrical aberrations decrease proportionally with the focal length. Reverse telephoto layouts will become more common, particularly when the system has a shutter. The increase in pixel count will require wide field of view lenses which present particular challenges. The impact of diffraction effects on the lens design is considerably increased. The fast F-number causes an increase in the diffraction limit of the system, but also increases geometric aberrations by a cube law. Therefore the balance between the diffraction limited and the aberration limited performance becomes more difficult. The first approach of the designer is to re-use proven designs originally intended for use with 17micron detectors. Some of these designs will have adequate performance at the Nyquist limit of the 12 micron detectors. Even smaller detector pitches, such as 10 micron, will demand new approaches to Infra Red lens design. The traditional approach will quickly increase the number of elements to 3 or even more. This could lead to the lenses with medium fields of view driving the system cost. A close cooperation between the camera developer and lens designer will become necessary in order to explore alternate approaches, such as wavefront coding, in order to reach the most cost effective solution.

  6. Laue-DIC: a new method for improved stress field measurements at the micrometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J., E-mail: johannpetit@u-paris10.fr [LEME, Université Paris Ouest, 50 rue de Sèvres, F-92410 Ville d’Avray (France); Castelnau, O. [PIMM, CNRS, Arts and Métiers ParisTech, 151 Bd de l’Hopital, F-75013 Paris (France); Bornert, M. [Laboratoire Navier, Université Paris-Est, École des Ponts ParisTech, F-77455 Marne-la-Vallée (France); Zhang, F. G. [PIMM, CNRS, Arts and Métiers ParisTech, 151 Bd de l’Hopital, F-75013 Paris (France); Hofmann, F.; Korsunsky, A. M. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Faurie, D. [LSPM, CNRS, Université Paris 13, 93430 Villetaneuse (France); Le Bourlot, C. [INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Micha, J. S. [Université Grenoble Alpes, INAC-SPrAM, F-38000 Grenoble (France); CNRS, SPrAM, F-38000 Grenoble (France); CRG-IF BM32 at ESRF, 71 Avenue des Martyrs, F-38000 Grenoble (France); Robach, O.; Ulrich, O. [Université Grenoble Alpes, INAC-SPrAM, F-38000 Grenoble (France); CRG-IF BM32 at ESRF, 71 Avenue des Martyrs, F-38000 Grenoble (France); CEA, INAC-SP2M, F-38000 Grenoble (France)

    2015-05-09

    The increment of elastic strain distribution, with a micrometer spatial resolution, is obtained by the correlation of successive Laue images. Application to a bent Si crystal allows evaluation of the accuracy of this new Laue-DIC method, which is about 10{sup −5}. A better understanding of the effective mechanical behavior of polycrystalline materials requires an accurate knowledge of the behavior at a scale smaller than the grain size. The X-ray Laue microdiffraction technique available at beamline BM32 at the European Synchrotron Radiation Facility is ideally suited for probing elastic strains (and associated stresses) in deformed polycrystalline materials with a spatial resolution smaller than a micrometer. However, the standard technique used to evaluate local stresses from the distortion of Laue patterns lacks accuracy for many micromechanical applications, mostly due to (i) the fitting of Laue spots by analytical functions, and (ii) the necessary comparison of the measured pattern with the theoretical one from an unstrained reference specimen. In the present paper, a new method for the analysis of Laue images is presented. A Digital Image Correlation (DIC) technique, which is essentially insensitive to the shape of Laue spots, is applied to measure the relative distortion of Laue patterns acquired at two different positions on the specimen. The new method is tested on an in situ deformed Si single-crystal, for which the prescribed stress distribution has been calculated by finite-element analysis. It is shown that the new Laue-DIC method allows determination of local stresses with a strain resolution of the order of 10{sup −5}.

  7. Optical design study and prototyping of a dual-field zoom lens imaging in the 1-5 micron infrared waveband

    Science.gov (United States)

    Reshidko, Dmitry; Reshidko, Pavel; Carmeli, Ran

    2015-09-01

    Optical systems can provide simultaneous imaging in several spectral bands and thus be much more useful. A new and current generation of focal plane arrays is allowing detection in more than one spectral region. The design of a refractive imaging lens for such detectors requires correcting chromatic aberrations over the wider range of wavelengths. However, the fewer available refracting materials, the material properties that change between the spectral bands, and the system transmission requirements make the design of such lenses particularly challenging. We present a dual-field zoom lens designed for a cooled detector sensing across short-wave infrared (SWIR) and midwave infrared (MWIR) spectral bands (continuous imaging for 1-5 μm). This zoom lens has a 75 mm focal length in the wide mode and a 250mm focal length in the narrow mode, and operates at f/4.7 in both discrete zoom positions. The lens is actively compensated to work in thermal environments from -20°C to +60°C. We discuss the optical design methodology, review the selection of materials and coatings for the optical elements, and analyze the transmission of the lens and optical performance. A prototype system has been manufactured and assembled. We validate our design with experimental data.

  8. Development of a bent Laue beam-expanding double-crystal monochromator for biomedical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Mercedes, E-mail: mercedes.m@usask.ca [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); Samadi, Nazanin [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Belev, George [Canadian Light Source, 44 Innovation Boulevard, Saskatoon, Saskatchewan (Canada); Bassey, Bassey [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); Lewis, Rob [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Monash University, Clayton, Victoria 3800 (Australia); Aulakh, Gurpreet [University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada); Chapman, Dean [University of Saskatchewan, 116 Science Place, Room 163, Saskatoon, Saskatchewan (Canada); University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan (Canada)

    2014-03-13

    A bent Laue beam-expanding double-crystal monochromator was developed and tested at the Biomedical Imaging and Therapy beamline at the Canadian Light Source. The expander will reduce scanning time for micro-computed tomography and allow dynamic imaging that has not previously been possible at this beamline. The Biomedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source has produced some excellent biological imaging data. However, the disadvantage of a small vertical beam limits its usability in some applications. Micro-computed tomography (micro-CT) imaging requires multiple scans to produce a full projection, and certain dynamic imaging experiments are not possible. A larger vertical beam is desirable. It was cost-prohibitive to build a longer beamline that would have produced a large vertical beam. Instead, it was proposed to develop a beam expander that would create a beam appearing to originate at a source much farther away. This was accomplished using a bent Laue double-crystal monochromator in a non-dispersive divergent geometry. The design and implementation of this beam expander is presented along with results from the micro-CT and dynamic imaging tests conducted with this beam. Flux (photons per unit area per unit time) has been measured and found to be comparable with the existing flat Bragg double-crystal monochromator in use at BMIT. This increase in overall photon count is due to the enhanced bandwidth of the bent Laue configuration. Whilst the expanded beam quality is suitable for dynamic imaging and micro-CT, further work is required to improve its phase and coherence properties.

  9. Design for an efficient single photon source based on a single quantum dot embedded in a parabolic solid immersion lens.

    Science.gov (United States)

    Devaraj, Vasanthan; Baek, Jongseo; Jang, Yudong; Jeong, Hyuk; Lee, Donghan

    2016-04-18

    We have designed a single photon emitter based on a single quantum dot embedded within a single mode parabolic solid immersion lens (pSIL) and a capping low-index pSIL. Numerical simulations predicted that the emitter performance should exhibit a high photon collection efficiency with excellent far-field emission properties, broadband operation, and good tolerance in its geometric (spatial configuration) parameters. Good geometric tolerance in a single-mode pSIL without yielding significant losses in the photon collection efficiency is advantageous for device fabrication. The low-index top pSIL layer provided this structure with a high photon collection efficiency, even in the case of a small numerical aperture (NA). Photon collection efficiencies of 64% and 78% were expected for NA values of 0.41 and 0.5, respectively. In addition to the benefits listed above, our combined pSIL design provided excellent broadband performance in a 100 nm range.

  10. Development of a 3D CZT detector prototype for Laue Lens telescope

    DEFF Research Database (Denmark)

    Caroli, Ezio; Auricchio, Natalia; Del Sordo, Stefano

    2010-01-01

    implementing a set of three RENA-3 for a total of 128 channels. The front-end electronics and the operating logics (in particular coincidence logics for polarisation measurements) are handled by a versatile and modular multi-parametric back end electronics developed using FPGA technology....

  11. WSi2/Si Multilayer Sectioning by Reactive Ion Etching for Multilayer Laue Lens Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Bouet, N.; Conley, R.; Biancarosaa, J.; Divanc, R.; Macrander, A. T.

    2010-08-01

    SPIE Conference paper/talk presentation: Introduction: Reactive ion etching (RIE) has been employed in a wide range of fields such as semiconductor fabrication, MEMS (microelectromechanical systems), and refractive x-ray optics with a large investment put towards the development of deep RIE. Due to the intrinsic differing chemistries related to reactivity, ion bombardment, and passivation of materials, the development of recipes for new materials or material systems can require intense effort and resources. For silicon in particular, methods have been developed to provide reliable anisotropic profiles with good dimensional control and high aspect ratios1,2,3, high etch rates, and excellent material to mask etch selectivity...

  12. Development of design of CLA: target lens line-focusing system

    Science.gov (United States)

    Li, Xuechun; Zhu, Jianqiang

    1999-08-01

    In this paper the principle of CLA-target system to obtain focal line with homogenous intensity distribution was described. And tow new structure modal CLA used for improving the homogeneous of focal line was described and the numerical results of the classical CLA and new type CLA was also given. Those result showed that the focal line long-range intensity distribution can be improved greatly by using CLA with optimized unequal cylindrical lens element for beam with Gaussian intensity distribution and by using hybrid element CLA for the case of super-Gaussian distribution. The optimal process was treated by simulated annealing method. The intensity modulation decreased to 0.7 percent for optimized 4-element unequal width CLA system when incident laser with Gaussian section distribution.

  13. Large-Scale Nanofabrication of Designed Nanostructures Using Angled Nanospherical-Lens Lithography for Surface Enhanced Infrared Absorption Spectroscopy.

    Science.gov (United States)

    Chien, Yi-Hsin; Wang, Chang-Han; Liu, Chi-Ching; Chang, Shih-Hui; Kong, Kien Voon; Chang, Yun-Chorng

    2017-07-26

    Nanophotonics has been a focused research discipline for the past decade and has resulted in many novel concepts that promise to change human life. However, the actual penetration of this research into real products is severely limited mostly due to the slow development of economic nanofabrication. In this study, we have demonstrated a versatile and low-cost nanofabrication method referred to as "angled nanospherical-lens lithography (A-NLL)", which is able to produce large-scale and periodic nanopatterns. The nanopatterns designed within a two-dimensional polar chart can be carefully fabricated on the substrate. The fabricated patterns easily cover an area larger than 1 cm(2), which is beneficial as platforms for surface enhanced infrared absorption (SEIRA) where an expensive and bulky IR microscope is not required. We believe that the proposed A-NLL method is ideal for industrialization of future nanophotonic applications.

  14. Motion-free hybrid design laser beam propagation analyzer using a digital micromirror device and a variable focus liquid lens.

    Science.gov (United States)

    Sheikh, Mumtaz; Riza, Nabeel A

    2010-06-01

    To the best of our knowledge, we propose the first motion-free laser beam propagation analyzer with a hybrid design using a digital micromirror device (DMD) and a liquid electronically controlled variable focus lens (ECVFL). Unlike prior analyzers that require profiling the beam at multiple locations along the light propagation axis, the proposed analyzer profiles the beam at the same plane for multiple values of the ECVFL focal length, thus eliminating beam profiler assembly motion. In addition to measuring standard Gaussian beam parameters, the analyzer can also be used to measure the M(2) beam propagation parameter of a multimode beam. Proof-of-concept beam parameter measurements with the proposed analyzer are successfully conducted for a 633 nm laser beam. Given the all-digital nature of the DMD-based profiling and all-analog motion-free nature of the ECVFL beam focus control, the proposed analyzer versus prior art promises better repeatability, speed, and reliability.

  15. Contrast visual acuity after multifocal intraocular lens implantation:aspheric versus spherical design

    Directory of Open Access Journals (Sweden)

    Jun-Hua Li

    2014-02-01

    Full Text Available AIM: To evaluate contrast visual acuity (CVA after implantation of an aspheric apodized diffractive intraocular lens (IOL or a spherical apodized diffractive IOL in cataract surgery.METHOD: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL (30 eyes and a spherical AcrySof ReSTOR SN60D3 IOL (30 eyes. CVA with best distance correction was measured at 4 contrast levels (100%, 25%, 10% and 5% under 3 levels of chart luminance [250, 85 and 25 candelas per square meter (cd/m2] using a multi-functional visual acuity tester (MFVA-100.RESULTS:At 12 months after surgery, there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m2 (P100%=0.875 and P25%=0.057 and 85cd/m2 (P100%=0.198 and P25%=0.193 between the aspheric group and the spherical group. However, the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m2 (P10%=0.042 and P5%=0.007 and 85cd/m2 (P10%=0.002 and P5%=0.039. Under the luminance level of 25cd/m2, no significant differences was found in the 100% CVA between the 2 group (P100%=0.245, while aspheric group had better visual acuity in the remaining 3 contracts (P25%=0.023, P10%=0.026 and P5%=0.002, respectively.CONCULSION:The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.Keyword:cataract surgery; intraocular lens; contrast sensitivity; visual acuity

  16. Optical lens-shift design for increasing spatial resolution of 3D ToF cameras

    Science.gov (United States)

    Lietz, Henrik; Hassan, M. Muneeb; Eberhardt, Jörg

    2017-02-01

    Sensor resolution of 3D time-of-flight (ToF) outdoor-capable cameras is strongly limited because of its large pixel dimensions. Computational imaging permits enhancement of the optical system's resolving power without changing physical sensor properties. Super-resolution (SR) algorithms superimpose several sub-pixel-shifted low-resolution (LR) images to overcome the system's limited spatial sampling rate. In this paper, we propose a novel opto-mechanical system to implement sub-pixel shifts by moving an optical lens. This method is more flexible in terms of implementing SR techniques than current sensor-shift approaches. In addition, we describe a SR observation model that has been optimized for the use of LR 3D ToF cameras. A state-of-the-art iteratively reweighted minimization algorithm executes the SR process. It is proven that our method achieves nearly the same resolution increase as if the pixel area would be halved physically. Resolution enhancement is measured objectively for amplitude images of a static object scene.

  17. James Webb Space Telescope Optical Simulation Testbed II. Design of a Three-Lens Anastigmat Telescope Simulator

    CERN Document Server

    Choquet, Élodie; N'Diaye, Mamadou; Perrin, Marshall D; Soummer, Rémi

    2014-01-01

    The James Webb Space Telescope (JWST) Optical Simulation Testbed (JOST) is a tabletop experiment designed to reproduce the main aspects of wavefront sensing and control (WFSC) for JWST. To replicate the key optical physics of JWST's three-mirror anastigmat (TMA) design at optical wavelengths we have developed a three-lens anastigmat optical system. This design uses custom lenses (plano-convex, plano-concave, and bi-convex) with fourth-order aspheric terms on powered surfaces to deliver the equivalent image quality and sampling of JWST NIRCam at the WFSC wavelength (633~nm, versus JWST's 2.12~micron). For active control, in addition to the segmented primary mirror simulator, JOST reproduces the secondary mirror alignment modes with five degrees of freedom. We present the testbed requirements and its optical and optomechanical design. We study the linearity of the main aberration modes (focus, astigmatism, coma) both as a function of field point and level of misalignments of the secondary mirror. We find that t...

  18. Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry.

    Science.gov (United States)

    Bordy, J M; Gualdrini, G; Daures, J; Mariotti, F

    2011-03-01

    The work package two of the ORAMED project--Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme--is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of H(p)(3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, D(lens,est) through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of D(lens).

  19. Design, assembly, and testing of a high-resolution relay lens used for holography with operation at both doubled and tripled Nd:YAG laser wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Sorenson, Danny S [Los Alamos National Laboratory; Pazuchanics, Peter D [Los Alamos National Laboratory; Malone, Robert M [NSTEC; Cox, Brian C [NSTEC; Frogget, Brent C [NSTEC; Kaufman, Morris I [NSTEC; Capelle, Gene A [NSTEC/SB; Grover, M [NSTEC/SB; Stevens, Gerald D [NSTEC/SB; Turley, William D [NSTEC/SB

    2009-01-01

    The design and assembly of a nine-element lens that achieves >2000 1p/mm resolution at a 355-nm wavelength (ultraviolet) has been completed. By adding a doublet to this lens system, operation at a 532-nm wavelength (green) with > 1100 1p/mm resolution is achieved. This lens is used with high-power laser light to record holograms of fast-moving ejecta particles from a shocked metal surface located inside a test package. Part of the lens and the entire test package are under vacuum with a 1-cm air gap separation. Holograms have been recorded with both doubled and tripled Nd:YAG laser light. The UV operation is very sensitive to the package window's tilt. If this window is tilted by more than 0.1 degrees, the green operation performs with better resolution than that of the UV operation. The setup and alignment are performed with green light, but the dynamic recording can be done with either UV light or green light. A resolution plate can be temporarily placed inside the test package so that a television microscope located beyond the hologram position can archive images of resolution patterns that prove that the calibration wires., interference filter, holographic plate, and relay lenses are in their correct positions. Part of this lens is under vacuum, at the point where the laser illumination passes through a focus. Alignment and tolerancing of this high-resolution lens are presented. Resolution variation across the 12-mm field of view and throughout the 5-mm depth of field is discussed for both wavelengths.

  20. Optical design of fish-eye lens used for monitoring system%用于监控系统的鱼眼镜头光学设计

    Institute of Scientific and Technical Information of China (English)

    梁久伟; 罗春华; 杨铭

    2011-01-01

    The bionics principle is used based on the principle of fish-eye lens and monitor control system requirements. A fish-eye lens that FOV is 180° and relative aperture is 1/1. 6 is designed with the optical system design software ZEMAX to meet the requirement of the monitor control system on panoramic monitor. The designed system consists nine lenses. The total length is 68. 5mm, image receiver is 1/3 inch CCD, the MTF value is more than 0. 3 within 0. 7 FOV at 80lp/mm, the MTF value of FOV are more than 0. 5 within 0 FOV at 120lp/mm. The lens has high distortion because of this lens is a fish-eye lens. Its barrel distortion approximates to 100% within 1. 0 FOV.%为了满足监控系统中单镜头可实现全景监控的需求,运用仿生学原理,在原有鱼眼镜头的基础上结合监控系统的需求,运用ZEMAX软件设计了一款视场为180°,相对孔径为1/1.6的鱼眼镜头.该镜头由9片透镜组成,总长度为68.5mm,采用1/3英寸CCD作为图像接收器件.在120lp/mm时,其MTF曲线在轴上大于0.4,在80lp/mm时,在0.7带上大于0.3.由于是超广角镜头,此镜头畸变很大,在边缘视场具有接近100%的桶形畸变.

  1. Wood lens design philosophy based on a binary additive manufacturing technique

    Science.gov (United States)

    Marasco, Peter L.; Bailey, Christopher

    2016-04-01

    Using additive manufacturing techniques in optical engineering to construct a gradient index (GRIN) optic may overcome a number of limitations of GRIN technology. Such techniques are maturing quickly, yielding additional design degrees of freedom for the engineer. How best to employ these degrees of freedom is not completely clear at this time. This paper describes a preliminary design philosophy, including assumptions, pertaining to a particular printing technique for GRIN optics. It includes an analysis based on simulation and initial component measurement.

  2. LASER INDUCED THERMAL LENS EFFECT

    Institute of Scientific and Technical Information of China (English)

    沈俊; 黄孟才; 江景云; 施教芳

    1991-01-01

    The thermal lens effect has emerged in recent years as a novel ,highly sensitive tool for the study of the very weak molecular absorption of light energy,This paper discusses the theory and technique of the thermal lens measurement.Some opplications of the thermal lens measurement are described.A mode-mismatched dual-beam thermal lens experimental arragement with a modulated probe beam ,designed by the authors.for trace analysis is presented,and its detection limit was found to be 4.1×10-7 for Cu(Ⅱ) in ethanol and 80 mW excitation power.

  3. Verification of the weak equivalence principle with Laue diffracting neutrons: Test experiment

    Science.gov (United States)

    Vezhlev, E. O.; Voronin, V. V.; Kuznetsov, I. A.; Semenikhin, S. Yu.; Fedorov, V. V.

    2013-07-01

    We propose a novel experiment to test the weak equivalence principle (WEP) for the Laue diffracting neutron. Our experiment is based on an essential magnification of an external affect on neutron diffracting by Laue for the Bragg angles close to the right one in couple with additional enhancement factor which exists due to the delay of the Laue diffracting neutron at such Bragg angles. This enhancement phenomena is proposed to be utilized for measuring the force which deviates from zero if WEP is violated. The accuracy of measuring inertial to gravitational neutron masses ratio for the introduced setup can reach ˜10-5, which is more than one order superior to the best present-day result.

  4. Design and performance of a 30 KV electron gun with ten independent cathodes & a magnetic lens.

    Energy Technology Data Exchange (ETDEWEB)

    Rudys, Joseph Matthew; Reed, Kim Warren

    2006-08-01

    Measurements on a 30 kV electron gun with ten independent cathodes, operating in a 6.5 Tesla (T) magnetic field are presented. An earlier paper covered the design of this electron gun [1]. Experimental results are compared to model predictions. Beam current is compared to theoretical space charge limited flow.

  5. The design of double electrostatic-lens optics for resonance enhanced multiphoton ionization and photoelectron imaging experiments

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Zehua; Li, Chunsheng; Qin, Zhengbo, E-mail: wave0403@163.com, E-mail: xfzheng@mail.ahnu.edu.cn; Zheng, Xianfeng, E-mail: wave0403@163.com, E-mail: xfzheng@mail.ahnu.edu.cn; Yao, Guanxin; Zhang, Xianyi; Cui, Zhifeng [Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000 (China)

    2015-06-15

    Compared to single ion/electron-optics for velocity-map imaging, a double-focusing lens assembly designed not only allows for mapping velocity imaging of photoelectrons but also allows for investigating the vibrational structure of the intermediate states of neutral species in resonance enhanced multiphoton ionization (REMPI) spectra. In this presentation, in order to record REMPI and photoelectron spectra separately, we have constructed a compact photoelectron velocity-map imaging (VMI) apparatus combined with an opposite linear Wiley-Mclaren time-of-flight mass spectrometer (TOFMS). A mass resolution (m/Δm) of ∼1300 for TOFMS and electron energy resolution (ΔE/E) of 2.4% for VMI have been achieved upon three-photon ionization of Xe atom at 258.00 nm laser wavelength. As a benchmark, in combination of one-color (1 + 1) REMPI and photoelectron imaging of benzene via 6{sup 1} and 6{sup 1}1{sup 1} vibronic levels in the S{sub 1} state, the vibrational structures of the cation and photoelectron angular anisotropy are unraveled. In addition, two-color (1 + 1′) REMPI and photoelectron imaging of aniline was used to complete the accurate measurement of ionization potential (62 271 ± 3 cm{sup −1}). The results suggest that the apparatus is a powerful tool for studying photoionization dynamics in the photoelectron imaging using vibrational-state selected excitation to the intermediate states of neutrals based on REMPI technique.

  6. Fo cusing p erformance of hard X-ray single Kinoform lens%Kinoform单透镜的硬X射线聚焦性能∗

    Institute of Scientific and Technical Information of China (English)

    陈直; 许良; 陈荣昌; 杜国浩; 邓彪; 谢红兰; 肖体乔

    2015-01-01

    Kinoform单透镜可以高效聚焦硬X射线至纳米量级,在X射线纳米显微学和纳米光谱学领域有着重要的应用前景。基于衍射光学和傅里叶光学理论,给出了X射线经由Kinoform单透镜聚焦的物理模型,基于数值模拟,研究了不同材料、光子能量、台阶数量和顶点曲率半径对Kinoform单透镜聚焦性能的影响。结果表明,孔径为1 mm的Kinoform单透镜对30 keV的X射线聚焦,可以得到14 nm焦斑、62µm焦深,且可实现4个量级的光强增益和大于30%的光强透过率。%Nowadays, X-ray nanoprobe plays an important role in many research fields, ranging from materials science to geophysics and environmental science, to biophysics and protein crystallography. Refractive lenses, mirrors, and Laue lenses, can all focus X-rays into a spot with a size of less than 50 nm. To design a refractive lens at fixed wavelengths, absorption in the lens material can be significantly reduced by removing 2π phase-shifting regions. This permits short focal length devices to be fabricated with small radii of curvatures at the lens apex. This feature allows one to obtain a high efficiency X-ray focusing. The reduced absorption loss also enables optics with a larger aperture, and hence improving the resolution for focusing. Since the single Kinoform lens can focus hard X-ray into a spot on a nanoscale efficiently, it has very important application prospect in X-ray nano-microscopy and nano-spectroscopy. We present a theoretical analysis of optical properties of the single Kinoform lens. Using Fermat’s principle of least time, an exact solution of the single Kinoform lens figure is derived. The X-ray diffraction theory is reviewed. The complex amplitude transmittance function of the X-ray single Kinoform lens is derived. According to Fourier optics and optical diffraction theory, we set up the physical model of X-ray single Kinoform lens focusing. Employing this physical model, we study

  7. 单反相机立体摄取镜头的研制%Design of Three-dimensional Intake Lens in SLR Camera

    Institute of Scientific and Technical Information of China (English)

    贾正松; 张德忠

    2011-01-01

    提出一种单镜头立体照相方案,通过对镜头立体光圈及其控制电路的设计,制造出用于单反数码相机的立体镜头,并分析该技术方案所获立体图像的特点.实践表明,该镜头结构简单、使用方便、能一次性形成多种立体图像,有利于立体照相技术的推广.%A single-lens stereo camera program is proposed. Through the lens aperture and the three-dimensional design of the control circuit, three-dimensional lens is created for SLR digital cameras. The technical program is analyzed and three-dimensional image features are obtained. Practical results show that the lens structure is simple, and easy to use, can form a variety of one-time three-dimensional images. So it is helpful for the promotion of three-dimensional radiographic technique.

  8. Double einzel lens extraction for the JYFL 14 GHz ECR ion source designed with IBSimu

    Science.gov (United States)

    Toivanen, V.; Kalvas, T.; Koivisto, H.; Komppula, J.; Tarvainen, O.

    2013-05-01

    In order to improve the performance of the JYFL 14 GHz electron cyclotron resonance ion source (ECRIS) and initiate low energy beam transport (LEBT) upgrade at the University of Jyväskylä, Department of Physics (JYFL) accelerator laboratory, a new ion beam extraction system has been designed and installed. The development of the new extraction was performed with the ion optical code IBSimu, making it the first ECRIS extraction designed with the code. The measured performance of the new extraction is in good agreement with the simulations. Compared to the old extraction the new system provides improved beam quality, i.e. lower transverse emittance values and improved structure of beam profiles, and transmission efficiency of the LEBT and the JYFL K-130 cyclotron. For example, the transmission efficiencies of 40Ar8+ and 84Kr16+ beams have increased by 80 and 90%, respectively. The new extraction system is capable of handling higher beam currents than the old one, which has been demonstrated by extracting new 4He+ and 4He2+ record beam currents of 1.12 mA and 720 μA, exceeding the old records of the JYFL 14 GHz ECRIS by a factor of two.

  9. Design of the partial concentrator lens for III-V on Si static concentration

    Science.gov (United States)

    Araki, Kenji; Ota, Yasuyuki; Lee, Kan-Hua; Nishioka, Kensuke; Yamaguchi, Masafumi

    2017-09-01

    To compete with the flat-plate crystalline Silicon cell module, III-V on Si structure is developed. However, it is clear that the situation of the higher cost of III-V cell relative to the Silicon cell will be unchanged. Then, it is preferred concentrating III-V cell for further savings. The partial concentrator is expanding the acceptance angle despite the higher concentration ratio. It is achieved by better performance balance of on-axis and high incidence angle. The new and generalized design method of the partial concentrator was developed. The profile function was constructed by selected Zernike's polynomial considering rotational symmetry. The full conditions of the calculation including the initial value and the radial and azimuthal degree of the function were examined. It was found that the recommended radial and azimuthal degree were 12 and 12.

  10. Optics design for J-TEXT ECE imaging with field curvature adjustment lens

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y.; Zhao, Z.; Liu, W. D.; Xie, J., E-mail: jlxie@ustc.edu.cn [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Hu, X.; Muscatello, C. M.; Domier, C. W.; Luhmann, N. C.; Chen, M.; Ren, X. [University of California at Davis, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Zhuang, G.; Yang, Z. [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-11-15

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas. Of particular importance has been microwave electron cyclotron emission imaging (ECEI) for imaging T{sub e} fluctuations. Key to the success of ECEI is a large Gaussian optics system constituting a major portion of the focusing of the microwave radiation from the plasma to the detector array. Both the spatial resolution and observation range are dependent upon the imaging optics system performance. In particular, it is critical that the field curvature on the image plane is reduced to decrease crosstalk between vertical channels. The receiver optics systems for two ECEI on the J-TEXT device have been designed to ameliorate these problems and provide good performance with additional field curvature adjustment lenses with a meniscus shape to correct the aberrations from several spherical surfaces.

  11. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil......Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...... of probabilistic functionalism, and concerns the environment and the mind, and adaptation by the latter to the former. This entry is about the lens model, and probabilistic functionalism more broadly. Focus will mostly be on firms and their employees, but, to fully appreciate the scope, we have to keep in mind...

  12. Progressive lens design method based on addition power curve transformation%基于加光曲线变换的渐进镜片设计方法

    Institute of Scientific and Technical Information of China (English)

    薛登攀; 李湘宁; 李笑

    2012-01-01

    Starting with the vertex definition of spectacle lens, the principle and structure of the progressive addition lens, the rule and method of meridian designing are introduced. The type of addition power curve in the periphery area is chose, and then, the surface power distribution of the lens is given by the method based on transformation of meridian addition power law under the boundary conditions. To compare with the traditional methods, this one has the advantages not only in the unified power distribution form of the progressive addition lens, but also with more freedom and flexibility choice for the designer. The lens surface sag, power and astigmatism distribution can be obtained according to differential geometry of curving surface. It is proved by an embodiment that the required progressive addition lens can be designed with this method.%从眼镜片用顶焦度的定义出发,探讨了渐进加光镜片的原理和结构,介绍了子午线设计的原则和方法.选择镜片周边的加光曲线形式,通过在边界条件下对子午加光曲线做变换,确定镜片表面的屈光度分布,给出了基于加光曲线变换的设计方法.与传统方法相比,不仅在形式上统一了渐进加光镜片的屈光度分布,而且还为设计者提供了更自由灵活的选择.利用曲面微分几何原理获得镜片表面面型矢高,计算屈光度和像散分布.通过实例设计表明,此方法可以设计出所需渐进特征的加光镜片.

  13. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil......Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...

  14. Modern lens antennas for communications engineering

    CERN Document Server

    Thornton, John

    2012-01-01

    The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

  15. Computer simulation design of millimeter-wave Rotman lens antenna%毫米波Rotman透镜天线的计算机仿真设计

    Institute of Scientific and Technical Information of China (English)

    刘敏; 丁君; 郭陈江

    2013-01-01

    A millimeter-wave Rotman lens multibeam antenna with opetating frequency 37GHz and 7 beams is designed in this paper. The choices of Rotman lens focal length are analyzed to achieve the minimum phase errors. Rotman lens and antenna array are realized with microstrip and simulated together. Simulations show that this antenna can achieve multibeam and wide-angle scanning.%设计了一个频率在37 GHz的7波束毫米波Rotman透镜多波束天线.分析了透镜焦距的选择方法,以实现最小的相位误差.Rotman透镜采用微带形式实现,天线单元采用微带贴片天线,并实现了Rotman透镜与天线阵列的整体仿真.结果表明,该天线可以实现多波束宽角度的扫描特性.

  16. High-energy transmission Laue micro-beam X-ray diffraction: a probe for intra-granular lattice orientation and elastic strain in thicker samples.

    Science.gov (United States)

    Hofmann, Felix; Song, Xu; Abbey, Brian; Jun, Tea-Sung; Korsunsky, Alexander M

    2012-05-01

    An understanding of the mechanical response of modern engineering alloys to complex loading conditions is essential for the design of load-bearing components in high-performance safety-critical aerospace applications. A detailed knowledge of how material behaviour is modified by fatigue and the ability to predict failure reliably are vital for enhanced component performance. Unlike macroscopic bulk properties (e.g. stiffness, yield stress, etc.) that depend on the average behaviour of many grains, material failure is governed by `weakest link'-type mechanisms. It is strongly dependent on the anisotropic single-crystal elastic-plastic behaviour, local morphology and microstructure, and grain-to-grain interactions. For the development and validation of models that capture these complex phenomena, the ability to probe deformation behaviour at the micro-scale is key. The diffraction of highly penetrating synchrotron X-rays is well suited to this purpose and micro-beam Laue diffraction is a particularly powerful tool that has emerged in recent years. Typically it uses photon energies of 5-25 keV, limiting penetration into the material, so that only thin samples or near-surface regions can be studied. In this paper the development of high-energy transmission Laue (HETL) micro-beam X-ray diffraction is described, extending the micro-beam Laue technique to significantly higher photon energies (50-150 keV). It allows the probing of thicker sample sections, with the potential for grain-level characterization of real engineering components. The new HETL technique is used to study the deformation behaviour of individual grains in a large-grained polycrystalline nickel sample during in situ tensile loading. Refinement of the Laue diffraction patterns yields lattice orientations and qualitative information about elastic strains. After deformation, bands of high lattice misorientation can be identified in the sample. Orientation spread within individual scattering volumes is

  17. 自由曲面LED汽车前照灯光学透镜设计方法%Design method of LED headlamp freeform optical lens

    Institute of Scientific and Technical Information of China (English)

    王洪; 陈赞吉; 吴衡; 葛鹏

    2014-01-01

    由于LED配光特性不同于传统光源,为了将LED应用于汽车照明中需对LED进行二次光学设计。文中根据LED汽车前照灯的配光特性,提出了一种自由曲面LED汽车前照灯光学透镜的设计方法。首先由能量守恒原理,在接收屏上的坐标和透镜自由曲面上的坐标之间建立能量的一一对应关系,基于非成像光学理论,采用照度优化设计法,运用数值计算求解出光学透镜曲面各个点坐标的坐标值,并使用三维模型软件制作出透镜光学模型。通过蒙特卡洛模拟法来追迹光线仿真,最后的配光效果完全满足《汽车用LED前照灯》(GB25991-2010)标准,系统的光学效率得到显著提高,可达到91%。%Different from the light distribution characteristics of the traditional light source, LED light characteristics are more complex, the second optical design for LED used in automotive lighting needs to be done. According to the light distribution characteristics of LED automobile headlamp, a freeform optical lens design method for LED headlamp was presented in this paper. By establishing one- to- one relationship between the coordinates of point on the receiving surface and the coordinates of point on the freeform surface of lens according to energy conservation principle, determining the mapping relationship between the energy and the lens, and applying the illumination optimization method, the coordinates of point on the freeform surface of lens was solved out with numerical methods based on non- imaging optics theory, then modeling software was used to establish an optical model for the freeform optical lens. Through tracing the light with Monte Carlo simulation method, the final effect of light distribution fully meets the Automotive headlamps with LED light sources and/or LED modules (GB25991-2010) standards. The simulation results show that the optical efficiency is improved greatly and can be up to 91%.

  18. Bionic intraocular lens with variable focus and integrated structure

    Science.gov (United States)

    Liang, Dan; Wang, Xuan-Yin; Du, Jia-Wei; Xiang, Ke

    2015-10-01

    This paper proposes a bionic accommodating intraocular lens (IOL) for ophthalmic surgery. The designed lens has a solid-liquid mixed integrated structure, which mainly consists of a support ring, elastic membrane, rigid lens, and optical liquid. The lens focus can be adjusted through the deformation of the lens front surface when compressed. The integrated structure of the IOL is presented, as well as a detailed description of the lens materials and fabrication process. Images under different radial pressures are captured, and the lens deformation process, accommodating range, density, and optical property are analyzed. The designed lens achieves a 14.6 D accommodating range under a radial pressure of 51.4 mN and a 0.24 mm alteration of the lens outer radius. The deformation property of the lens matches well with the characteristic of the eye and shows the potential to help patients fully recover their vision accommodation ability after the cataract surgery.

  19. Moiré pattern from a multiple Bragg–Laue interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Kenji, E-mail: hirano-k@sit.jp; Fukamachi, Tomoe; Kanematsu, Yoshinobu; Jongsukswat, Sukswat; Negishi, Riichirou; Ju, Dongying [Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293 (Japan); Hirano, Keiichi [Institute of Material Structure Science, KEK-PF, High Energy Accelerator Research Organization, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Kawamura, Takaaki [Department of Mathematics and Physics, University of Yamanashi, Kofu, Yamanashi 400-8510 (Japan)

    2012-01-01

    A moiré pattern is observed by dividing the incident beam into two and formed by multiple Bragg–Laue interference fringes corresponding to the two incident beams. The coherency of X-rays from a bending-magnet beamline is evaluated using the moiré pattern. In X-ray section topography of Si 220 diffraction in a multiple Bragg–Laue mode, a moiré pattern is observed when the incident beam is divided into two parts by inserting a platinum wire in the middle of the beam. The moiré pattern can be explained by the summation of two interference fringes corresponding to the two incident beams. The coherency of the X-rays from the bending-magnet beamline is estimated using the moiré pattern.

  20. X-ray dark-field imaging and its application. Laue case analyzer

    CERN Document Server

    Ando, M

    2003-01-01

    A system on X-ray dark-field imaging under development and its application is reported. That comprises an asymmetric monochromator and a Laue case analyzer that has a specified thickness for a given X-ray photon energy or wavelength and a sample locating inbetween these. This system uses Si 4,4,0 diffraction for both X-ray optics element in a parallel arrangement. In order to achieve the dark-field imaging condition the Si Laue analyzer should be 1.075 mm in thickness for the X-ray energy of 35 keV. Since this system is very simple one can expect a variety of applications including material science, biology, palaeontology and clinical medicine where a large view area with size of 100 mm x 100 mm is needed. (author)

  1. A neutron image plate quasi-Laue diffractometer for protein crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Cipriani, F.; Castagna, J.C.; Wilkinson, C. [European Molecular Biology Laboratory, Grenoble (France)] [and others

    1994-12-31

    An instrument which is based on image plate technology has been constructed to perform cold neutron Laue crystallography on protein structures. The crystal is mounted at the center of a cylindrical detector which is 400mm long and has a circumference of 1000mm, with gadolinium oxide-containing image plates mounted on its exterior surface. Laue images registered on the plate are read out by rotating the drum and translating a laser read head parallel to the cylinder axis, giving a pixel size of 200{mu}m x 200{mu}m and a total read time of 5 minutes. Preliminary results indicate that it should be possible to obtain a complete data set from a protein crystal to atomic resolution in about two weeks.

  2. LED Freeform Lens Design for Street Uniform Illumination%用于道路均匀照明的 LED 自由曲面透镜设计

    Institute of Scientific and Technical Information of China (English)

    贺志华; 董前民; 王少雷; 李敏

    2014-01-01

    鉴于LED在道路照明应用中的复杂性和特殊性,以非成像光学为基础,提出了一种新颖的用于道路均匀照明透镜设计方案。运用微分几何原理,建立自由曲面面型的一阶拟线性双曲型偏微分方程,并在matlab中进行数值求解,将所得面型数据导入SolidWorks中建立透镜模型,该透镜将LED朗伯分布转化为道路照明所需的蝙蝠翼分布。通过Tracepro对所建透镜进行光线追迹,结果表明10m处目标面的整体均匀度在85%以上,能量利用率为89.2%。在对扩展光源配光时,该光学系统仍保持较好的照明效果,不仅有效照明区域符合预期,且照度均匀度优于0.80。用DIALux模拟该透镜组成的5×10式模组的路灯系统的照明效果,结果显示路面照度均匀度达0.83,符合国家标准。%Given the complexity and particularity of the LED in the application of street lighting , this paper presents a new lens design method for street uniform lighting based on non-imaging optics .Using the theory of differential geometry to set up the first-order quasi-linear hyperbolic partial differential equations of the freeform lens surface , and solve it by numerical solution in matlab , using the data of the lens profile , the lens model is established in SolidWorks .The designed lens can convert the Lambert distribution of the LED into the bat wing distribution for street lighting .The designed optical system simulated with ray-tracing in TracePro, the results show that the overall uniformity of the 10m distance target plane is above 85%, and the efficiency is 89 .2%.This optical system still maintains good lighting effect when point at extended light source .Not only is the effective illumination area in line with expectations , but also can keep the uniformity above 80%.The street lighting system , which uses the designed lens consisting of 5 ×10-in modular, simulated the lighting effects in DIALux .The

  3. First results of the EXILL and FATIMA campaign at the Institut Laue Langevin

    Energy Technology Data Exchange (ETDEWEB)

    Jolie, Jan; Regis, Jean-Marc; Saed-Samii, Nima; Warr, Nigel [IKP, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Wilmsen, Dennis [IKP, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); GANIL, BP 55027 (France); France, Gilles de; Clement, Emmanuel [GANIL, BP 55027 (France); Blanc, Aurelien; Jentschel, Michael; Koester, Uli; Mutti, Paolo; Soldner, Thorsten [ILL, 71 Av. des Martyrs, 38042 Grenoble (France); Simpson, Gary [University of Western Scotland, Paisley, PA1 2BE (United Kingdom); UIrban, Waldek [Faculty of Physics, University of Warsaw, 02-093 Warsaw (Poland); Bruce, Alison; Lalskovski, Stefan [SCEM, University of Brighton, Brighton BN2 4GJ (United Kingdom); Fraile, Luis [Grupo de Fisica Nuclear, Universidad Complutese, 28040 Madrid (Spain); Kroell, Thorsten [Institut fuer Kernphysik, TU Darmstadt, Darmstadt (Germany); Podolyak, Zsolt; Regan, Patrick [Dept. of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Korten, Wolfram [CEA, Centre de Saclay, IRFU, 91191 Gif-sur-Yvette (France); Ur, Calin; Marginean, Nicu [Horia Hulubei NIPNE, 77125 Bucharest (Romania)

    2015-07-01

    At the PF1B cold neutron beam line at the Institut Laue Langevin the EXILL and FATIMA array consisting of 8 EXOGAM clover Ge detectors and 16 LaBr3(Ce) scintillators was used for the measurement of lifetimes using the generalised centroid difference method. The studied nuclei were formed by the (n,γ) and (n,fission) reactions. We report on the set-up and present first results on {sup 90}Zr and {sup 196}Pt.

  4. A Theoretical Study of the Two-Dimensional Point Focusing by Two Multilayer Laue Lenses.

    Energy Technology Data Exchange (ETDEWEB)

    Yan,H.; Maser, J.; Kang, H.C.; Macrader, A.; Stephenson, B.

    2008-08-10

    Hard x-ray point focusing by two crossed multilayer Laue lenses is studied using a full-wave modeling approach. This study shows that for a small numerical aperture, the two consecutive diffraction processes can be decoupled into two independent ones in respective directions. Using this theoretical tool, we investigated adverse effects of various misalignments on the 2D focus profile and discussed the tolerance to them. We also derived simple expressions that described the required alignment accuracy.

  5. Ewald: an extended wide-angle Laue diffractometer for the second target station of the Spallation Neutron Source.

    Science.gov (United States)

    Coates, Leighton; Robertson, Lee

    2017-08-01

    Visualizing hydrogen atoms in biological materials is one of the biggest remaining challenges in biophysical analysis. While X-ray techniques have unrivaled capacity for high-throughput structure determination, neutron diffraction is uniquely sensitive to hydrogen atom positions in crystals of biological materials and can provide a more complete picture of the atomic and electronic structures of biological macromolecules. This information can be essential in providing predictive understanding and engineering control of key biological processes, for example, in catalysis, ligand binding and light harvesting, and to guide bioengineering of enzymes and drug design. One very common and large capability gap for all neutron atomic resolution single-crystal diffractometers is the weak flux of available neutron beams, which results in limited signal-to-noise ratios giving a requirement for sample volumes of at least 0.1 mm(3). The ability to operate on crystals an order of magnitude smaller (0.01 mm(3)) will open up new and more complex systems to studies with neutrons which will help in our understanding of enzyme mechanisms and enable us to improve drugs against multi resistant bacteria. With this is mind, an extended wide-angle Laue diffractometer, 'Ewald', has been designed, which can collect data using crystal volumes below 0.01 mm(3).

  6. Design and analyses of an ultra-thin flat lens for wave front shaping in the visible

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kai, E-mail: nianhua110@hotmail.com [Department of Biomedical Engineering, Bioengineering College of Chongqing University, Chongqing University, Chongqing 400044 (China); Li, Yiyan, E-mail: liy10@unlv.nevada.edu [Department of Electrical and Computer Engineering, University of Nevada, Las Vegas, Las Vegas, NV 89154-4026 (United States); Tian, Xuelong, E-mail: xltian@cqu.edu.cn [Department of Biomedical Engineering, Bioengineering College of Chongqing University, Chongqing University, Chongqing 400044 (China); Zeng, Dajun, E-mail: dajunzeng@163.com [Department of Biomedical Engineering, Bioengineering College of Chongqing University, Chongqing University, Chongqing 400044 (China); Gao, Xueli, E-mail: 2455031293@qq.com [Department of Biomedical Engineering, Bioengineering College of Chongqing University, Chongqing University, Chongqing 400044 (China)

    2015-12-04

    An ultra-thin flat lens is proposed for focusing circularly polarized light in the visible range. Anisotropic C-shaped nanoantennas with phase discontinuities are used to form the metasurface of the lens. The phase response of the C-shaped nanoantennas can be manipulated by simply rotating the angle of the unit nanoantenna. A 600 nm incident circularly polarized light is focused by the proposed techniques. Good agreements are observed by using our MoM and a commercial FDTD software package. The computation time spent by using MoM is approximately 10–100 times smaller than using FDTD. All the results show the proposed nanoantenna array has a great potential for nanoscale optical microscopy, solar cell energy conversion enhancement, as well as integrated optical circuits. - Highlights: • Successfully focusing a 600 nm light using a circularly C-shaped nanoantenna array. • The computation time spent by using MoM is approximately 10–100 times smaller than FDTD. • A good agreement is observed using our MoM to the classic FDTD method.

  7. Experimental Contact Lens to Prevent Glaucoma-Induced Blindness

    Science.gov (United States)

    ... Home Page An Experimental Contact Lens to Prevent Glaucoma-Induced Blindness By Sharon Reynolds Posted January 23, 2014 An experimental contact lens design releases a glaucoma medicine at a steady rate for up to ...

  8. Extraction of accurate structure-factor amplitudes from Laue data: wavelength normalization with wiggler and undulator X-ray sources.

    Science.gov (United States)

    Srajer, V; Crosson, S; Schmidt, M; Key, J; Schotte, F; Anderson, S; Perman, B; Ren, Z; Teng, T Y; Bourgeois, D; Wulff, M; Moffat, K

    2000-07-01

    Wavelength normalization is an essential part of processing of Laue X-ray diffraction data and is critically important for deriving accurate structure-factor amplitudes. The results of wavelength normalization for Laue data obtained in nanosecond time-resolved experiments at the ID09 beamline at the European Synchrotron Radiation Facility, Grenoble, France, are presented. Several wiggler and undulator insertion devices with complex spectra were used. The results show that even in the most challenging cases, such as wiggler/undulator tandems or single-line undulators, accurate wavelength normalization does not require unusually redundant Laue data and can be accomplished using typical Laue data sets. Single-line undulator spectra derived from Laue data compare well with the measured incident X-ray spectra. Successful wavelength normalization of the undulator data was also confirmed by the observed signal in nanosecond time-resolved experiments. Single-line undulators, which are attractive for time-resolved experiments due to their high peak intensity and low polychromatic background, are compared with wigglers, based on data obtained on the same crystal.

  9. Optimization of Zoom Lens with Discrete State of Liquid Lens Elements by Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Cheng-Mu Tsai

    2015-01-01

    Full Text Available This paper is to employ liquid lens elements to design a lens with zoom function by using the genetic algorithm (GA optimization. The liquid lens elements used in the proposal can apply voltage adjustment to generate the electrical field that induces the liquid with electric conductivity to vary the surface curvature between two different kinds of liquids. According to the voltage level, the liquid lens element makes the discrete variation of the curvature and thickness realize the zoom function without moving the lens groups so that the overall length can be reduced. However, it is difficult to design the zoom lens under the discrete variation of the curvature and thickness in the liquid lens elements and the mechanical space that is constantly limited. The GA offers a flexible way for lens optimization. We regarded the spot size as the fitness function to look for the optimum curvatures, thickness, and the corresponding statuses of liquid lens elements for the zoom lens. As a result, the zoom lens with constant space can be realized by running the selection, crossover, and mutation operation in the GA optimization.

  10. Contact lens in keratoconus

    Directory of Open Access Journals (Sweden)

    Varsha M Rathi

    2013-01-01

    Full Text Available Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP lenses, soft and soft toric lenses, piggy back contact lenses (PBCL, hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL.

  11. Crystallography using synchrotron radiation X-ray. Application of Weissenberg and time resolved Laue methods to macromolecular structure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sakabe, Noriyoshi [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1994-12-31

    The three-dimensional structures of macromolecules under static and dynamic conditions are very important for the study of molecular biology. X-ray crystallography is the most powerful tool to obtain the three-dimensional structures of the macromolecules of especially large size, for which synchrotron radiation X-ray is used, The collection of diffraction data is the first, most important step for crystalline structure analysis. Efforts have been exerted to establish the data collection system using monochromatic synchrotron radiation X-ray (SRX). The diffraction intensity data collection system combined with a newly developed Weissenberg camera for macromolecules and an image plate (IP) using SRX has been established at the Photon Factory. Many important biological structures by high resolution have already come out with this data collection system, which is used also for the study on enzymatic reaction mechanism. A time resolved Laue camera has been designed, and the preliminary experiment has been carried out in the Photon Factory. These systems are reported. (K.I.).

  12. Polarisation measurements with a CdTe pixel array detector for Laue hard X-ray focusing telescopes

    CERN Document Server

    Caroli, E; Pisa, A; Stephen, J B; Frontera, F; Castanheira, M T D; Sordo, S; Caroli, Ezio; Silva, Rui M. Curado da; Pisa, Alessandro; Stephen, John B.; Frontera, Filippo; Castanheira, Matilde T. D.; Sordo, Stefano del

    2006-01-01

    Polarimetry is an area of high energy astrophysics which is still relatively unexplored, even though it is recognized that this type of measurement could drastically increase our knowledge of the physics and geometry of high energy sources. For this reason, in the context of the design of a Gamma-Ray Imager based on new hard-X and soft gamma ray focusing optics for the next ESA Cosmic Vision call for proposals (Cosmic Vision 2015-2025), it is important that this capability should be implemented in the principal on-board instrumentation. For the particular case of wide band-pass Laue optics we propose a focal plane based on a thick pixelated CdTe detector operating with high efficiency between 60-600 keV. The high segmentation of this type of detector (1-2 mm pixel size) and the good energy resolution (a few keV FWHM at 500 keV) will allow high sensitivity polarisation measurements (a few % for a 10 mCrab source in 106s) to be performed. We have evaluated the modulation Q factors and minimum detectable polaris...

  13. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    Directory of Open Access Journals (Sweden)

    Ladan Espandar

    2011-01-01

    Full Text Available Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular lens (IOL. The hydrophilic design of the lens is optimized to address dysphotopsia while maintaining biocompatibility, optical clarity, resistance to damage, and resistance to biocontamination. Aspheric lenses decrease postoperative spherical aberration. The addition of the Softec lens provides clinicians with another option for IOL placement; however, randomized comparative studies of this lens to others already on the market remain to be completed.Keywords: hydrophilic acrylic intraocular lens, Softec HD intraocular lens, aspheric intraocular lens, IOL

  14. Design of a proton-electron beam overlap monitor for the new RHIC electron lens, based on detecting energetic backscattered electrons

    Energy Technology Data Exchange (ETDEWEB)

    Thieberger T.; Beebe, E.; Fischer, W.; Gassner, D.; Gu, X.; Hamdi, K.; Hock, J.; Minty, M.; Miller, T.; Montag, C.; Pikin, A.

    2012-04-15

    The optimal performance of the two electron lenses that are being implemented for high intensity polarized proton operation of RHIC requires excellent collinearity of the {approx}0.3 mm RMS wide electron beams with the proton bunch trajectories over the {approx}2m interaction lengths. The main beam overlap diagnostic tool will make use of electrons backscattered in close encounters with the relativistic protons. These electrons will spiral along the electron guiding magnetic field and will be detected in a plastic scintillator located close to the electron gun. A fraction of these electrons will have energies high enough to emerge from the vacuum chamber through a thin window thus simplifying the design and operation of the detector. The intensity of the detected electrons provides a measure of the overlap between the e- and the opposing proton beams. Joint electron arrival time and energy discrimination may be used additionally to gain some longitudinal position information with a single detector per lens.

  15. Partial Lens Design Based on the LED Road Lighting%基于 LED 道路照明的偏光透镜设计

    Institute of Scientific and Technical Information of China (English)

    王少雷; 张莉; 李敏; 贺志华; 王乐

    2014-01-01

    In this paper , we designed a partial lens used in LED road lighting , which was based on non-uniform grid partition method .The lens can project more light on the road .The design of the partial lens reduces the light pollution , and improves the utilization of road lighting effectively .And it is not affected by the installation height of lamps and the placement of light pole , it greatly improves the lamp shape and the beautiful design flexibility .The uniformity is 77.6%, which is simulated in the optical software Lighttools . When the light absorption loss of the material and reflection loss of the interface are fully considered , the light energy utilization is as high as 84.5%.And the IES model of light distribution curve of the partial lens is calculated in the lighting simulation software Dialux , the brightness uniformity is 0.74 , and the TI is controlled in 9%.These indicators of intensity of illumination uniformity , brightness uniformity and glare control meet the requirements of The Standards of Street Lighting Design completely.It will have a broad prospect in the application and promotion of road lighting in the future .%基于非均匀网格划分法设计了一种用于LED道路照明的偏光透镜。该透镜能够把LED发出的光线更多地投射在路面上。这种偏光透镜设计减少了道路外的光污染,同时有效提高了路面的光线利用率。在光学软件Lighttools的模拟中,测得整个光学系统照度均匀度为77.6%。并且充分考虑材料的吸收损失和界面的反射损失后,光能利用率高达84.5%。在照明仿真软件Dialux中对该偏光透镜的配光曲线IES模型导入后在模拟道路中进行计算仿真,得到其亮度总均匀度为0.74,并且眩光限制阈值增量控制在9%。所以,该偏光透镜的亮度均匀度、照度均匀度及眩光控制等指标都很好地满足了我国《城市道路照明设计标准》的要求。

  16. New source for ultracold neutrons at the Institut Laue-Langevin

    Science.gov (United States)

    Piegsa, F. M.; Fertl, M.; Ivanov, S. N.; Kreuz, M.; Leung, K. K. H.; Schmidt-Wellenburg, P.; Soldner, T.; Zimmer, O.

    2014-07-01

    A new intense superthermal source for ultracold neutrons (UCN) was installed at a dedicated beam line at the Institut Laue-Langevin. Incident neutrons with a wavelength of 0.89 nm are converted to UCN in a 5-liter volume filled with superfluid He4 at a temperature of about 0.7 K. The UCN can be extracted to room temperature experiments. We present the cryogenic setup of the source, a characterization of the cold neutron beam, and UCN production measurements, where a UCN density in the production volume of at least 55 per cm3 was determined.

  17. New source for ultracold neutrons at the Institut Laue-Langevin

    CERN Document Server

    Piegsa, F M; Ivanov, S N; Kreuz, M; Leung, K K H; Schmidt-Wellenburg, P; Soldner, T; Zimmer, O

    2014-01-01

    A new intense superthermal source for ultracold neutrons (UCN) has been installed at a dedicated beam line at the Institut Laue-Langevin. Incident neutrons with a wavelength of 0.89 nm are converted to UCN in a five liter volume filled with superfluid $^4$He at a temperature of about 0.7 K. The UCN can be extracted to room temperature experiments. We present the cryogenic setup of the source, a characterization of the cold neutron beam, and UCN production measurements, where a UCN density in the production volume of at least 55 per cm$^3$ was determined.

  18. Nanosecond x-ray Laue diffraction apparatus suitable for laser shock compression experiments.

    Science.gov (United States)

    Suggit, Matthew; Kimminau, Giles; Hawreliak, James; Remington, Bruce; Park, Nigel; Wark, Justin

    2010-08-01

    We have used nanosecond bursts of x-rays emitted from a laser-produced plasma, comprised of a mixture of mid-Z elements, to produce a quasiwhite-light spectrum suitable for performing Laue diffraction from single crystals. The laser-produced plasma emits x-rays ranging in energy from 3 to in excess of 10 keV, and is sufficiently bright for single shot nanosecond diffraction patterns to be recorded. The geometry is suitable for the study of laser-shocked crystals, and single-shot diffraction patterns from both unshocked and shocked silicon crystals are presented.

  19. Dynamical focusing by bent, asymmetrically cut perfect crystals in Laue geometry.

    Science.gov (United States)

    Guigay, J P; Ferrero, C

    2016-07-01

    A semi-analytical approach based on the influence functions of a point source located on the crystal surface has been adopted to show that the focusing ability of cylindrically bent Laue crystals may be strongly enhanced by replacing symmetrically cut crystals with asymmetrically cut crystals. This approach is generally applicable to any distance between the X-ray source and the focusing bent crystal. A mathematically straightforward method to simplify the derivation of the already known expression of the influence functions in the case of deformed crystals with a constant strain gradient (e.g. cylindrically bent crystals) is also presented.

  20. Trends of contact lens prescribing in Jordan.

    Science.gov (United States)

    Haddad, Mera F; Bakkar, May; Gammoh, Yazan; Morgan, Philip

    2016-10-01

    To evaluate contact lens prescribing trends among optometrists in Jordan. Optometrists from 173 practices in Jordan were surveyed about prescribing contact lenses in their practice. Practitioners were required to record information for the last 10 patients that visited their practice. Demographic data such as age and gender was obtained for each patient. In addition, data relating to lens type, lens design, replacement methods and the care regime advised to each patient were recorded. Practitioners were required to provide information relating to their education and years of experience. The influence of education and experience with respect to lens prescribing trends was explored using linear regression models for the proportions of lens types fitted for patients. A total of 1730 contact lens fits were analyzed. The mean (±SD) age of lens wearers was 26.6 (±7.9) years, of whom 65% were female. Conventional hydrogel lenses were the most prescribed lenses, accounting for 60.3% of the fits, followed by silicone hydrogel lenses (31.3%), and rigid lenses (8.4%). In terms of lens design, spherical lenses appeared to be most commonly prescribed on monthly basis. Daily disposable lenses were second most prescribed lens modality, accounting for 20.4% of the study sample. Multi-purpose solution (MPS) was the preferred care regimen, with a prevalence of 88.1% reported in the study sample, compared to hydrogen peroxide (1-step and 2-step), which represented only 2.8% of the patients in this study. A relationship was established between the two educational groups for rigid lens prescribing (F=17.4, ptrends among optometrists in Jordan. Contact lens prescribing in terms of lens type, lens design, modality of wear and care regimen agree with global market trends with small variations. This report will help practitioners and the industry to detect any deficiencies in the contact lens market in Jordan, which will ease implementing current and future plans in developing contact

  1. Physics of electrostatic lens

    Science.gov (United States)

    1981-09-01

    The purpose of this program was to study the physics of the ion-energy boosting electrostatic lens for collective ion acceleration in the Luce diode. Extensive work was done in preparation for experiments on the PI Pulserad 1150. Analytic work was done on the orbit of protons in a mass spectrometer and a copper stack for nuclear activation analysis of proton energy spectrum has been designed. Unfortunately, a parallel program which would provide the Luce diode for the collective ion acceleration experiment never materialized. As a result no experiments were actually performed on the Pulserad 1150.

  2. Long-term pathologic follow-up of obsolete design: Choyce Mark VIII anterior chamber intraocular lens.

    Science.gov (United States)

    Ollerton, Andrew; Stagg, Brian C; Leishman, Lisa; Bodnar, Zachary; Werner, Liliana; Mamalis, Nick

    2012-02-01

    We analyzed an enucleated eye that was blind and painful from a 66-year-old patient implanted with a Tennant modification of the Choyce Mark VIII anterior chamber intraocular lens (IOL) as a secondary procedure in 1978. The eye developed glaucoma, with implantation of an Ahmed valve in 2006. Gross and light microscopic analyses showed corneal decompensation and vascularization, peripheral anterior and posterior synechiae, iris thinning, significant changes in the iris pigmented layer, fibrous tissue on the anterior surface of the iris, and Soemmerring ring formation in the periphery of capsular bag remnants. In addition, there was severe attenuation of the nerve fiber layer and extensive cupping of the optic disc. The IOL surface was overall smooth and regular, without warping of the footplates, and was partially covered by clumps of various cell elements, including giant cells intermixed with pigment. This study represents the longest clinicopathologic correlation report on this IOL. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  3. Design Multi- beam Dielectric Lens Antenna for Passive Millimeter Wave Imaging%毫米波多波束介质透镜天线设计

    Institute of Scientific and Technical Information of China (English)

    刘传全; 关福宏; 孙晓玮

    2011-01-01

    In this paper,aiming at the requirement of passive millimeter wave imaging, the traditional tapered slot antenna is improved. A new structure tapered slot antenna with corrugated edges and coupled dipole is applied as feed of dielectric lens antenna, feeding by microstrip with angle - slotline transition. Three - dimensional electromagnetic simulation software is used for simulation and design of the specific size parameters and the tapered slot antenna is measured; Key parameters and radiation patterns of multi - beam dielectric lens antenna with array feed is obtained by simulation.%研究优化天线设计问题,针对被动毫米波成像的需求,要求天线对目标实时扫描成像.传统结构的渐变缝隙天线性能和扫描成像数据率低,效果差.为解决上述问题,提出一种新结构,采用褶皱边缘和缝隙加偶极子的新型渐变缝隙天线作为透镜天线的馈源,以斜角微带-槽线过渡结构对渐变缝隙天线馈电,并利用三维电磁场仿真软件仿真设计了具体尺寸参数,并测试了相关结果.优化仿真得到了阵列馈源介质透镜多波束天线设计的关键参数和辐射方向图.最后进行仿真,结果表明,所设计的天线能很好的满足被动毫米波成像系统的需求.

  4. Improved multislice calculations for including higher-order Laue zones effects

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, I., E-mail: Ivan.Lobato@ua.ac.be [University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van Dyck, D. [University of Antwerp, Department of Physics, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2012-08-15

    A new method for including higher-order Laue zones (HOLZs) effects in an efficient way in electron scattering simulations has been developed and tested by detail calculations. The calculated results by the conventional multislice (CMS) method and the improved conventional multislice (ICMS) method using a large dynamical aperture to avoid numerical errors are compared with accurate results. We have found that the zero-order Laue zones (ZOLZs) reflection cannot be properly described only using the projected potential in the whole unit cell; in general, we need to subslice the electrostatic potential inside the unit cell. It is shown that the ICMS method has higher accuracy than the CMS method for the calculation of the ZOLZ, HOLZ and Pseudo-HOLZ reflections. Hence, ICMS method allows to use a larger slice thickness than the CMS method and reduces the calculation time. -- Highlights: Black-Right-Pointing-Pointer We have developed and tested a new method for including HOLZ effects in an efficient way in electron scattering simulations. Black-Right-Pointing-Pointer The ICMS method has higher accuracy than the CMS method for the calculation of the ZOLZ, HOLZ and Pseudo-HOLZ reflections. Black-Right-Pointing-Pointer ICMS method allows to use a larger slice thickness than the CMS method and reduces the calculation time.

  5. Laue diffraction: The key to neutron crystallography from submillimetric-volume single crystals

    Science.gov (United States)

    Lemée-Cailleau, M.-H.; McIntyre, G. J.; Wilkinson, C.

    2005-12-01

    For several decades, chemists and physicists have been fascinated by molecular compounds rich in delocalized electrons. In the solid state these compounds may offer a very rich fan of properties: optical, conduction and dielectric, magneticldots Each state is the result of a delicate balance amongst intra- and/or intermolecular interactions which can be controlled, not just by direct chemical substitution, but also by external parameters such as temperature, pressure, continuous electric or magnetic fields, or by light. The recent evolution of this field of science towards more and more sophisticated materials makes also more and more difficult their crystal growth. While neutron scattering is an extremely powerful technique to get precise structural information, it is also often disregarded in this field because usually large single crystals are required. With the recent renaissance of Laue techniques using the very intense flux provided by the reactor of the Institut Laue-Langevin (ILL), accurate structural and/or magnetic information can be now extracted routinely from molecular crystals of volume 0.1 mm3 or smaller, with easy possibilities of high pressure (up to 3 GPa) down to 0.2 K. A general survey of these new possibilities is illustrated by an example taken from the field of low-dimensional organic complexes.

  6. 热透镜效应补偿的高功率 Nd∶YAG 激光器的优化设计%Optimal design of high power Nd∶YAG laser based on compensation of thermal lens effect

    Institute of Scientific and Technical Information of China (English)

    吴羽; 龙晓莉; 焦中兴; 何广源; 张倩

    2015-01-01

    In order to obtain 1064nm laser with high power and high beam quality , a laser resonator was designed to solve thermal lens effect with a concave lens as compensation lens .The selection of the compensation lens was analyzed .A Nd∶YAG laser with a compensation lens and a plano-plano cavity was verified in the experiment .High beam quality 55W 1064nm laser was obtained when the focal length of the concave lens was 250mm and the transmittance of the output mirror was 30%.This research is helpful to the design of laser resonators with high power and beam quality .%为了获得高功率、高光束质量的1064nm激光,采用凹透镜作为补偿透镜来补偿激光棒的热透镜效应。对补偿透镜的选取进行理论分析,并使用所设计的包含补偿透镜的平平谐振腔Nd∶YAG激光器进行了实验验证。在实验中,使用焦距为250mm的凹透镜、透过率为30%的输出耦合镜,获得了55W 的高功率、高光束质量的1064nm激光输出。结果表明,此项研究对高功率、高光束质量激光器谐振腔的设计是有帮助的。

  7. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  8. Nanoparticle-Laden Contact Lens for Controlled Ocular Delivery of Prednisolone: Formulation Optimization Using Statistical Experimental Design

    Directory of Open Access Journals (Sweden)

    Amr ElShaer

    2016-04-01

    Full Text Available Human eye is one of the most accessible organs in the body, nonetheless, its physiology and associated precorneal factors such as nasolacrimal drainage, blinking, tear film, tear turnover, and induced lacrimation has significantly decreased the residence time of any foreign substances including pharmaceutical dosage forms. Soft contact lenses are promising delivery devices that can sustain the drug release and prolong residence time by acting as a geometric barrier to drug diffusion to tear fluid. This study investigates experimental parameters such as composition of polymer mixtures, stabilizer and the amount of active pharmaceutical ingredient on the preparation of a polymeric drug delivery system for the topical ocular administration of Prednisolone. To achieve this goal, prednisolone-loaded poly (lactic-co-glycolic acid (PLGA nanoparticles were prepared by single emulsion solvent evaporation method. Prednisolone was quantified using a validated high performance liquid chromatography (HPLC method. Nanoparticle size was mostly affected by the amount of co-polymer (PLGA used whereas drug load was mostly affected by amount of prednisolone (API used. Longer homogenization time along with higher amount of API yielded the smallest size nanoparticles. The nanoparticles prepared had an average particle size of 347.1 ± 11.9 nm with a polydispersity index of 0.081. The nanoparticles were then incorporated in the contact lens mixture before preparing them. Clear and transparent contact lenses were successfully prepared. When the nanoparticle (NP-loaded contact lenses were compared with control contact lenses (unloaded NP contact lenses, a decrease in hydration by 2% (31.2% ± 1.25% hydration for the 0.2 g loaded NP contact lenses and light transmission by 8% (unloaded NP contact lenses 94.5% NP 0.2 g incorporated contact lenses 86.23%. The wettability of the contact lenses remained within the desired value (<90 °C even upon incorporation of the NP. NP

  9. Real-time microstructure imaging by Laue microdiffraction: A sample application in laser 3D printed Ni-based superalloys

    Science.gov (United States)

    Zhou, Guangni; Zhu, Wenxin; Shen, Hao; Li, Yao; Zhang, Anfeng; Tamura, Nobumichi; Chen, Kai

    2016-06-01

    Synchrotron-based Laue microdiffraction has been widely applied to characterize the local crystal structure, orientation, and defects of inhomogeneous polycrystalline solids by raster scanning them under a micro/nano focused polychromatic X-ray probe. In a typical experiment, a large number of Laue diffraction patterns are collected, requiring novel data reduction and analysis approaches, especially for researchers who do not have access to fast parallel computing capabilities. In this article, a novel approach is developed by plotting the distributions of the average recorded intensity and the average filtered intensity of the Laue patterns. Visualization of the characteristic microstructural features is realized in real time during data collection. As an example, this method is applied to image key features such as microcracks, carbides, heat affected zone, and dendrites in a laser assisted 3D printed Ni-based superalloy, at a speed much faster than data collection. Such analytical approach remains valid for a wide range of crystalline solids, and therefore extends the application range of the Laue microdiffraction technique to problems where real-time decision-making during experiment is crucial (for instance time-resolved non-reversible experiments).

  10. Design of large dimension and rear projecting lens in laser display system%大屏背投激光显示广角镜头的设计

    Institute of Scientific and Technical Information of China (English)

    陈旭; 冯玉涛; 刘伟奇; 魏忠伦; 康玉思

    2011-01-01

    研究了背投激光显示广角投影镜头的设计,并给出了1个162.6 cm(64 in)背投激光显示广角镜头的设计实例.投影镜头前的光学引擎采用数字光处理显示方式,并应用数字微镜晶片(DMD)进行数字光学处理.系统焦距为7.38mm;设计波长为F,d,C;F数为2.46;全视场达到100°;在空间调制器DMD的Nyquist频率处,90%以上视场的MTF>0.6.系统渐晕系数为负,提高了投影显示像面边缘的光照度;全视场畸变<1.4%,1个像元尺寸内集中了点目标能量的90%以上.系统中使用了1个直角棱镜对光路进行折叠,减小了镜头长度,使棱镜展开后系统全长为259 mm.此外,该镜头只使用了1个二次项为0的非球面(高次项至8次),保证了镜头加工的可行性.设计结果显示,本文提出的设计方法有利于降低投影系统成本,实现产业化生产.%After comparing different structures of wide-angle projecting lenses, a wide-angle lens for 162.6 cm(64 in) rear projection laser display is designed. The focal length of the system is 7.38 mm,the wavelength used in the design is F, d, C and the full field of view reaches 100°. The technical indii of the projection lens are summarized as follows: DMD (Digital Micromirror Device) is used in the light digital processing, 90% MTF is greater than 0. 6 at the Nyquist frequency; the barrel distortion of the system is smaller than 1.4% ,and 90% of the energy in the point target is focused in a pixel dimension. Furthermore,a right angle prism is used to fold the optical path to decrease the length of the lens,so that the whole optical length of the system is 259 mm after outspreading the right angle prism. The vignetting factor of the wide angle is negative, which enhances the image illumination after projection. Moreover, an aspheric surface with the small size, zero conic constant and the maximum eight order coefficient is used to promise the feasibility of the mounting. Analytical results show that the

  11. Panoramic lens applications revisited

    Science.gov (United States)

    Thibault, Simon

    2008-04-01

    During the last few years, innovative optical design strategies to generate and control image mapping have been successful in producing high-resolution digital imagers and projectors. This new generation of panoramic lenses includes catadioptric panoramic lenses, panoramic annular lenses, visible/IR fisheye lenses, anamorphic wide-angle attachments, and visible/IR panomorph lenses. Given that a wide-angle lens images a large field of view on a limited number of pixels, a systematic pixel-to-angle mapping will help the efficient use of each pixel in the field of view. In this paper, we present several modern applications of these modern types of hemispheric lenses. Recently, surveillance and security applications have been proposed and published in Security and Defence symposium. However, modern hemispheric lens can be used in many other fields. A panoramic imaging sensor contributes most to the perception of the world. Panoramic lenses are now ready to be deployed in many optical solutions. Covered applications include, but are not limited to medical imaging (endoscope, rigiscope, fiberscope...), remote sensing (pipe inspection, crime scene investigation, archeology...), multimedia (hemispheric projector, panoramic image...). Modern panoramic technologies allow simple and efficient digital image processing and the use of standard image analysis features (motion estimation, segmentation, object tracking, pattern recognition) in the complete 360° hemispheric area.

  12. Test experiment to search for a neutron EDM by the Laue diffraction method

    CERN Document Server

    Fedorov, V V; Lelievre-Berna, E; Nesvizhevsky, V V; Petoukhov, A; Semenikhin, S Y; Soldner, T; Tasset, F; Voronin, V V

    2005-01-01

    A prototype experiment to measure the neutron electric dipole moment (nEDM) by spin-rotation in a non-centrosymmetric crystal in Laue geometry was carried out in order to investigate the statistical sensitivity and systematic effects of the method. The statistical sensitivity to the nEDM was about $6\\cdot 10^{-24}$ e$\\cdot $cm per day and can be improved by one order of magnitude for the full scale setup. Systematics was limited by the homogeneity of the magnetic field in the crystal region and by a new kind of spin rotation effect. We attribute this effect to a difference of the two Bloch waves amplitudes in the crystal, which is caused by the presence of a small crystal deformation due to a temperature gradient. In a revised scheme of the experiment, this effect could be exploited for a purposeful manipulation of the Bloch waves.

  13. The new powder diffractometer D1B of the Institut Laue Langevin

    Science.gov (United States)

    Puente Orench, I.; Clergeau, J. F.; Martínez, S.; Olmos, M.; Fabelo, O.; Campo, J.

    2014-11-01

    D1B is a medium resolution high flux powder diffractometer located at the Institut Laue Langevin, ILL. D1B a suitable instrument for studying a large variety of polycrystalline materials. D1B runs since 1998 as a CRG (collaborating research group) instrument, being exploited by the CNRS (Centre National de la Recherche Scientifique, France) and CSIC (Consejo Superior de Investigaciones Cientificas, Spain). In 2008 the Spanish CRG started an updating program which included a new detector and a radial oscillating collimator (ROC). The detector, which has a sensitive height of 100mm, covers an angular range of 128°. Its 1280 gold wires provide a neutron detection point every 0.1°. The ROC is made of 198 gadolinium- based absorbing collimation blades, regular placed every 0.67°. Here the present characteristics of D1B are reviewed and the different experimental performances will be presented.

  14. INTERFACE RESIDUAL STRESSES IN DENTAL ZIRCONIA USING LAUE MICRO-DIFFRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Bale, H. A.; Tamura, N.; Coelho, P.G.; Hanan, J. C.

    2009-01-01

    Due to their aesthetic value and high compressive strength, dentists have recently employed ceramics for restoration materials. Among the ceramic materials, zirconia provides high toughness and crack resistant characteristics. Residual stresses develop in processing due to factors including grain anisotropy and thermal coefficient mismatch. In the present study, polychromatic X-ray (Laue) micro-diffraction provided grain orientation and residual stresses on a clinically relevant zirconia model ceramic disk. A 0.5 mm x 0.024 mm region on zirconia was examined on a 500 nm scale for residual stresses using a focused poly-chromatic synchrotron X-ray beam. Large stresses ranging from - to + 1GPa were observed at some grains. On average, the method suggests a relatively small compressive stress at the surface between 47 and 75 MPa depending on direction.

  15. Applying an Activity Theory Lens to Designing Instruction for Learning about the Structure, Behavior, and Function of a Honeybee System

    Science.gov (United States)

    Danish, Joshua A.

    2014-01-01

    This article reports on a study in which activity theory was used to design, implement, and analyze a 10-week curriculum unit about how honeybees collect nectar with a particular focus on complex systems concepts. Students (n = 42) in a multi-year kindergarten and 1st-grade classroom participated in this study as part of their 10 regular classroom…

  16. The Optical Design of a System using a Fresnel Lens that Gathers Light for a Solar Concentrator and that Feeds into Solar Alignment Optics

    Science.gov (United States)

    Wilkerson, Gary W.; Huegele, Vinson

    1998-01-01

    The Marshall Space Flight Center (MSFC) has been developing a space deployable, lightweight membrane concentrator to focus solar energy into a solar furnace while remaining aligned to the sun. For an inner surface, this furnace has a cylindrical heat exchanger cavity coaligned to the optical axis; the furnace warms gas to propel the spacecraft. The membrane concentrator is a 1727 mm (68.00 in.) diameter, F/1.7 Fresnel lens. This large membrane is made from polyimide and is 0.076 mm (0.0030 in.) thick; it has the Fresnel grooves cast into it. The solar concentrator system has a super fast paraboloid reflector near the lens focus and immediately adjacent to the cylindrical exchanger cavity. The paraboloid collects the wide bandwidth and some of the solar energy scattered by the Fresnel lens. Finally, the paraboloid feeds the light into the cylinder. The Fresnel lens also possesses a narrow annular zone that focuses a reference beam toward four detectors that keep the optical system aligned to the sun; thus, occurs a refracting lens that focuses two places! The result can be summarized as a composite Fresnel lens for solar concentration and alignment.

  17. The Deep Lens Survey

    CERN Document Server

    Wittman, D; Dell'Antonio, I P; Becker, A C; Margoniner, V E; Cohen, J; Norman, D; Loomba, D; Squires, G; Wilson, G; Stubbs, C; Hennawi, J F; Spergel, D N; Boeshaar, P C; Clocchiatti, A; Hamuy, M; Bernstein, G; González, A; Guhathakurta, R; Hu, W; Seljak, U; Zaritsky, D

    2002-01-01

    The Deep Lens Survey (DLS) is a deep BVRz' imaging survey of seven 2x2 degree fields, with all data to be made public. The primary scientific driver is weak gravitational lensing, but the survey is also designed to enable a wide array of other astrophysical investigations. A unique feature of this survey is the search for transient phenomena. We subtract multiple exposures of a field, detect differences, classify, and release transients on the Web within about an hour of observation. Here we summarize the scientific goals of the DLS, field and filter selection, observing techniques and current status, data reduction, data products and release, and transient detections. Finally, we discuss some lessons which might apply to future large surveys such as LSST.

  18. Conjugate metamaterials and the perfect lens

    CERN Document Server

    Xu, Yadong; Xu, Lin; Chen, Huanyang

    2015-01-01

    In this letter, we show how transformation optics makes it possible to design what we call conjugate metamaterials. We show that these materials can also serve as substrates for making a subwavelength-resolution lens. The so-called "perfect lens", which is a lens that could focus all components of light (including propagating and evanescent waves), can be regarded as a limiting case, in which the respective conjugate metamaterials approach the characteristics of left-handed metamaterials, which have a negative refractive index.

  19. Contact lens in keratoconus

    OpenAIRE

    Varsha M Rathi; Preeji S Mandathara; Srikanth Dumpati

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the En...

  20. Iatrogenic Lens Injuries

    Directory of Open Access Journals (Sweden)

    Ümit Kamış

    2012-12-01

    Full Text Available During intraocular surgery, undesired damages of various etiology may occur in adjacent tissues. One of these tissues is the crystalline lens, which may be traumatized both in anterior segment and posterior segment surgeries, and when damaged, it usually causes marked decrease in visual acuity. The leading causes of iatrogenic lens injuries are intravitreal injection, laser iridotomy, phakic intraocular lens implantation, anterior chamber paracentesis, and vitreoretinal surgery. When crystalline lens damage occurs, its negative effect on visual function may be eliminated by performing cataract surgery intraoperatively or in elective conditions. (Turk J Ophthalmol 2012; 42: Supplement 27-30

  1. A Spectrometer Based on Diffractive Lens

    Institute of Scientific and Technical Information of China (English)

    WANG Daoyi; YAN Yingbai; JIN Guofan; WU Minxian

    2001-01-01

    A novel spectrometer is designed based on diffractive lens. It is essentially a flat field spectrometer. All the focal points are along the optical axis. Besides, all the asymmetrical aberrations vanish in our mounting. Thus low aberration can be obtained. In this article a diffractive lens is modeled as a special grating and analyzed by using a grating-based method. And a stigmatic point is introduced to reduce the aberrations.

  2. Lightweight autoclavable wide-angle contact lens for vitreous surgery.

    Science.gov (United States)

    Chalam, K V; Gupta, Shailesh K; Agarwal, Swati

    2007-01-01

    The authors describe an autoclavable, self-stabilizing, lightweight wide-angle contact lens for vitrectomy. The lens has two optical pieces with perforated plastic casing to sustain a high temperature (150 degrees C) for autoclaving. The lens has a 106 degrees static and 127 degrees dynamic field of view. The footplates and reduced weight (2.4 grams) due to the plastic casing allow self-stabilization of the lens. The open lens design.with high temperature resistant plastic prevents fogging during autoclaving and surgery. The autoclavable, self-stabilizing, lightweight wide-angle contact lens allows visualization of the peripheral retina during surgery and faster sterilization by autoclaving between surgeries without the disadvantage of lens fogging.

  3. Re-evaluating Science and Technology trough the lens of Arts and Graphic Design. A case study in La Spezia.

    Science.gov (United States)

    Locritani, Marina; Stroobant, Mascha; Talamoni, Roberta; Merlino, Silvia; Guccinelli, Giacomo; Benvenuti, Lucrezia; Zatta, Consuelo; Stricker, Federica; Zappa, Franco; Sgherri, Matteo

    2016-04-01

    The Human society is getting more and more involved with scientific and environmental issues both in terms of consciousness of good practices or participation in legislative decision-making processes. A common effort to preserve our planet is asked every day, for example through recycling practices, reduction of pollutant emission, use of alternative energies and awareness of risks natural and human-induced hazards. In addition, public opinion is often involved for issues of scientific interest (e.g. genetically modified organisms GMO). Unfortunately, the Eurobarometer (Eurobarometer Special 419 Report, Public perceptions of Science, Research and Innovation, 2014) indicates, especially for the Italian population, a low interest in science and therefore a lack of confidence in the potential of the research. It is hence important for people to be informed of the progress made by science and the importance of the researchers' role. Education, awareness and dissemination of scientific results and issues must be made through simple and appealing channels that must reach all levels of society and age groups: from children to older people. A common and comprehensible language for everyone can be found in Graphic Arts. For this reasons, the working group for science dissemination of La Spezia has increased, in recent years, close relationship with some artists (especially graphic designers). The collaboration between two different worlds (art and science) has allowed us to see an unusual approach and to translate concepts developed in images which everyone can understand also under an emotional point of view. Different techniques and tools based on the target to be reached have been employed. 1. Conferences. Gender differences issues in science professions and more generally in society has been addressed through interactive conferences and round tables during the European Researchers' Night 2015 and other occasions for general public. Arguments and questions were described

  4. Study of imperfect natural diamonds with the application of the X-ray synchrotron radiation (the 'Laue-SR' method)

    CERN Document Server

    Rylov, G M; Sobolev, N V; Kulipanov, G N; Kondratyev, V I; Tolochko, B P; Sharafutdinov, M R

    2001-01-01

    The 'Laue-SR' method has been realised for fast gathering experimental data in the study of imperfect natural and synthesised diamonds which are hard to investigate with the conventional X-ray methods. Time to obtain a diffraction pattern with the use of the polychromatic SR is shorter by several orders; the resolution of the image of substructure defects of a crystal lattice (as compared to the conventional Laue method) is improved by an order and does not vanish even at large disorientation or other non-coherent disturbances of the crystal lattice. The 'Laue-SR' method is especially appropriate for the study of intact, sufficiently large diamond crystals (up to 5 mm), since the diamond has a small coefficient of the X-ray absorption and is practically transparent in the operational range of the SR waves, lambda=0.5-1.5 A. This method was shown to be applied successfully for an accelerated study of a large bulk of imperfect natural diamond crystals without any preliminary preparation and without their destru...

  5. Dislocation-based plasticity model and micro-beam Laue diffraction analysis of polycrystalline Ni foil: A forward prediction

    Science.gov (United States)

    Song, Xu; Hofmann, Felix; Korsunsky, Alexander M.

    2010-10-01

    A physically-based, rate and length-scale dependent strain gradient crystal plasticity framework was employed to simulate the polycrystalline plastic deformation at the microscopic level in a large-grained, commercially pure Ni sample. The latter was characterised in terms of the grain morphology and orientation (in the bulk) by micro-beam Laue diffraction experiments carried out on beamline B16 at Diamond Light Source. The corresponding finite element model was developed using a grain-based mesh with the specific grain orientation assignment appropriate for the sample considered. Sample stretching to 2% plastic strain was simulated, and a post-processor was developed to extract the information about the local lattice misorientation (curvature), enabling forward-prediction of the Laue diffraction patterns. The 'streaking' phenomenon of the Laue spots (anisotropic broadening of two-dimensional (2D) diffraction peaks observed on the 2D detector) was correctly captured by the simulation, as constructed by direct superposition of reflections from different integration points within the diffraction gauge volume. Good agreement was found between the images collected from experiments and simulation patterns at various positions in the sample.

  6. Superlensing Microscope Objective Lens

    CERN Document Server

    Yan, Bing; Parker, Alan; Lai, Yukun; Thomas, John; Yue, Liyang; Monks, James

    2016-01-01

    Conventional microscope objective lenses are diffraction limited, which means that they cannot resolve features smaller than half the illumination wavelength. Under white light illumination, such resolution limit is about 250-300 nm for an ordinary microscope. In this paper, we demonstrate a new superlensing objective lens which has a resolution of about 100 nm, offering at least two times resolution improvement over conventional objectives in resolution. This is achieved by integrating a conventional microscope objective lens with a superlensing microsphere lens using a 3D printed lens adaptor. The new objective lens was used for label-free super-resolution imaging of 100 nm-sized engineering and biological samples, including a Blu-ray disc sample, semiconductor chip and adenoviruses. Our work creates a solid base for developing a commercially-viable superlens prototype, which has potential to transform the field of optical microscopy and imaging.

  7. Variable-focus cylindrical liquid lens array

    Science.gov (United States)

    Zhao, Wu-xiang; Liang, Dong; Zhang, Jie; Liu, Chao; Zang, Shang-fei; Wang, Qiong-hua

    2013-06-01

    A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2 and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for autostereoscopic 3D displays is emphasized.

  8. Design and Calibration of Double Lens 3D Camera System%双镜头3D摄像系统的设计与标定

    Institute of Scientific and Technical Information of China (English)

    梁发云; 何小明; 尤鹏飞; 王婧; 陈志文; 帖志成

    2013-01-01

    Stereo depth and parallax are closely related with the intrinsic parameters and the relation of mutual positions in 3D camera system.In this paper,the combined 3D camera system is designed on the base of the mathematical model of double lens 3D camera system and a new method of stereo calibration based on the imaging chessboard is proposed.It directly adopts LCD monitor to produce dynamic calibration target.Intrinsic and external parameters are calculated with calibration toolbox,and parameters are used to prove the rationality of the design of combined 3D camera system structure.The experimental results show that this calibration method not only acquires high precision,but also its process is convenient and fast,and can be applied to 3D camera system.The combined 3D camera system after calibration is in line with the human eye stereo vision.%3D摄像系统的内参数以及相互位置关系与视差、立体深度密切相关.在双镜头3D摄像系统数学模型的基础上设计了组合式3D摄像系统,提出了一种基于显像棋盘作为标定靶面的新方法,直接利用液晶显示器生成动态标定靶面,运用标定工具箱对双摄像头内外参数进行标定,并利用标定的参数验证组合式3D摄像系统结构设计的合理性.实验表明,该标定方法方便、快捷,操作过程简单,取得了较高的精度,适合3D摄像系统的标定,标定后的组合式3D摄像系统符合人眼立体视觉.

  9. 二氧化碳探测仪典型透镜支撑结构的设计及分析%Design and analysis of support structure for typical lens of carbon dioxide detector

    Institute of Scientific and Technical Information of China (English)

    梁彪; 刘伟

    2011-01-01

    为了降低外界载荷和温度变化对二氧化碳探测仪光学系统透镜面形及共轴的影响,根据系统的特点和技术要求,对其典型透镜的支撑结构进行了研究,设计了一种径向挠性支撑结构并建立了3D实体模型。运用工程CAD分析软件,采用非线性有限元分析方法对其进行了动静刚度特性和热特性仿真分析,验证了支撑结构设计的合理性。分析结果表明,透镜结构组件的一阶固有频率为1 301 Hz;利用面型拟合,得到了各工况下镜面面形误差值为PV≤λ/10,RMS≤λ/50,偏转误差≤1″。该径向支撑结构能很好地保持透镜共轴精度,减小了温度变化对镜面变形的影响,各项结果满足设计要求,证明了结构设计的合理性。%To decrease the influence of external loads and temperature changes on the surface deformation and alignment of a lens,a typical lens support structure was investigated based on the characteristics and technical requirements of carbon dioxide detectors for optical systems and specifications.A radial support structure was proposed and its 3D model was established.In order to verify the reasonability of the structure,the dynamic and static rigidities as well as thermal characteristics were analyzed by using a nonlinear analysis method through CAD engineering analytical software.The analysis results indicate that the first frequency of lens subassembly is 1 301 Hz,and lens surface shape error is as follows:PV≤λ/10,RMS≤λ/50,Tilt error≤1″.The radial support structure can keep lens centration well and reduce the influence of temperature diversification on the lens surface deformation.These results validate the rationality of structure and satisfy the design requirements.

  10. A laboratory based system for Laue micro x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N.

    2007-02-28

    A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References).

  11. The Laue diffraction method to search for a neutron EDM. Experimental test of the sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, V.V. E-mail: vfedorov@mail.pnpi.spb.ru; Lapin, E.G.; Lelievre-Berna, E.; Nesvizhevsky, V.V.; Petoukhov, A.K.; Semenikhin, S.Yu.; Soldner, T.; Tasset, F.; Voronin, V.V

    2005-01-01

    The feasibility of an experiment to search for the neutron electric dipole moment (EDM) by Laue diffraction in crystals without a center of symmetry was tested. At the PF1A beam of the ILL reactor a record time delay of {tau}{approx}2 ms for the passage of neutrons through a quartz crystal was reached for the (1 1 0) plane and diffraction angles equal to 88.5 degrees. That corresponds to an effective neutron velocity in the crystal of 20 m/s, while the velocity of the incident neutron was 800 m/s. It was shown experimentally that the value {tau}N{sup 1/2}, determining the method's sensitivity, has a maximum for the Bragg angle equal to 86 deg. The results allow us to estimate the statistical sensitivity of the method for the neutron EDM. For the PF1B beam of the ILL reactor the sensitivity can reach {approx}6x10{sup -25} e cm per day for the available quartz crystal.

  12. Fabrication of multilayer Laue lenses by a combination of pulsed laser deposition and focused ion beam.

    Science.gov (United States)

    Liese, Tobias; Radisch, Volker; Krebs, Hans-Ulrich

    2010-07-01

    X-ray diffractive techniques using Fresnel zone plate lenses of various forms are of great technical interest because of their ability to form images at very high spatial resolution, but the zone plates are unfortunately very hard to produce by lithography. Alternatively, multilayer Laue lenses (MLLs) and multilayer zone plates are used due to the higher and easily adjustable aspect ratio necessary for different wavelengths. In this paper, the fabrication of a MLL by a combination of pulsed laser deposition and focused ion beam machining is described. All steps of the production of a Ti/ZrO(2) microlens test structure with focal length of 220 microm (for a wavelength of 2.88 nm in the "water window" regime) are explained in detail. It is shown that this combination of two powerful techniques is very effective for the fabrication of MLL. All steps can be done in a very precise and controlled way without introducing damage to the grown multilayer structures.

  13. Feasibility analyses for HEU to LEU fuel conversion of the LAUE Langivin Institute (ILL) High Flux Reactor (RHF).

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, J.; Tentner. A.; Bergeron, A.; Nuclear Engineering Division

    2010-08-19

    The High Flux Reactor (RHF) of the Laue Langevin Institute (ILL) based in Grenoble, France is a research reactor designed primarily for neutron beam experiments for fundamental science. It delivers one of the most intense neutron fluxes worldwide, with an unperturbed thermal neutron flux of 1.5 x 10{sup 15} n/cm{sup 2}/s in its reflector. The reactor has been conceived to operate at a nuclear power of 57 MW but currently operates at 52 MW. The reactor currently uses a Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most worldwide research and test reactors have already started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on a mixture of uranium and molybdenum (UMo) is expected to allow the conversion of compact high performance reactors like the RHF. This report presents the results of reactor design, performance and steady state safety analyses for conversion of the RHF from the use of HEU fuel to the use of UMo LEU fuel. The objective of this work was to show that is feasible, under a set of manufacturing assumptions, to design a new RHF fuel element that could safely replace the HEU element currently used. The new proposed design has been developed to maximize performance, minimize changes and preserve strong safety margins. Neutronics and thermal-hydraulics models of the RHF have been developed and qualified by benchmark against experiments and/or against other codes and models. The models developed were then used to evaluate the RHF performance if LEU UMo were to replace the current HEU fuel 'meat' without any geometric change to the fuel plates. Results of these direct replacement analyses have shown a significant degradation of the RHF performance, in terms of both neutron flux and cycle

  14. Unitary lens semiconductor device

    Science.gov (United States)

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  15. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  16. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  17. 实现LED矩形均匀照明的透镜设计%Lens design for uniform illumination of rectangle area with LED

    Institute of Scientific and Technical Information of China (English)

    李竞

    2011-01-01

    Lens for uniform illumination of rectangle area with LED light source was designed. Based on differential geometry, a series of partial non-linear equations were constructed. According to the conservation law of energy, energy mapping relations between the source and the target plane were constructed. The points of the surface were obtained by solving the equations with fourth order Runge-Kutta formulas, and the desired free-form surface was got by curve fitting with Rhinoceros software. With ray tracing in ASAP software, the result indicates that the optical efficiency is more than 94. 01%, and the illumination uniformity of the predetermined illumination area on the target plane is better than 92. 73%. The continuity of the free-form surface was also analyzed, and the result shows that the continuity of the freeform surface is determined by energy mapping relations.%随着大功率LED发射光强的不断提高,采用单粒LED为光源的照明系统已得到普遍应用.设计一种以LED为光源实现矩形均匀照明的透镜,根据微分几何的理论建立透镜面型所满足的微分方程,然后根据能量映射关系和能量守恒定律建立面型与目标面坐标点之间的关系,并通过四阶龙格-库塔法求解微分方程得到面型数据,利用所得的面型数据在三维建模软件Rhinoceros中构建出所求透镜面型,并将透镜导入ASAP进行模拟.模拟结果表明:该光学系统效率达到94.01%,目标面照度均匀性优于92.73%.最后分析了自由曲面的连续性,指出能量映射关系决定着自由曲面的连续性.

  18. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct ... easy answer, and neither one considers long-term impacts. Phakic Intraocular Lenses for Nearsightedness FEB 27, 2017 ...

  19. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... lenses without a prescription in the United States. All contact lenses are medical devices that require a ... no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted ...

  20. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her with a corneal abrasion. ... Studies Look at Effects of Marijuana on Vision FEB ...

  1. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her ...

  2. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms ...

  3. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... ask for a prescription. There is no such thing as a "one size fits all" contact lens. ...

  4. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Vision and Daily Eye Drops After One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume Contacts May Contain Chemicals ...

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... 2016 More Eye Health News Studies Look at Effects of Marijuana on Vision FEB 28, 2017 By ...

  6. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ...

  7. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Contact Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent ... Worse? May 16, 2016 More Eye Health News New Dry Eye Treatment is a Tear-Jerker JUL ...

  8. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... glow-in-the-dark lizard lenses, costume contacts can certainly add a spooky, eye-popping touch. But ... consideration as a standard contact lens because they can be purchased over-the-counter or on the ...

  9. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ...

  10. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Healthy Contact Lens Use May 31, 2016 Is El Niño Making Your Allergies Worse? May 16, 2016 ... Number: * Email: * Enter code: * Message: Thank you Your feedback has been sent.

  11. Achromatic Fresnel Lens with Improved Efficiency for PV Systems

    Directory of Open Access Journals (Sweden)

    Mario González Montes

    2014-01-01

    Full Text Available This work is aimed to design and evaluate different achromatic Fresnel lens solutions capable of operating as concentrators aimed at photovoltaic cells systems. Throughout this study, the theoretical parametric design of the achromatic lens will be shown together with a series of simulations to verify the performance of each lens topology. The results will be compared with a standard Fresnel lens to ascertain the validity and effectiveness of the obtained design. Finally, a novel kind of hybrid lens is proposed, which combines the advantages of each type of lens (standard and Fresnel according to the optimal operating region of each design. Efficiency and concentration ratios of each particular lens are shown, regarding lens dimension, light’s incidence angle, or wavelength. Through this innovative achromatic design concentration ratios above 1000 suns, which hardly reach standard Fresnel lenses. Furthermore chromatic dispersion is minimized and the efficiency rate is over 85% of efficiency for a wide spectral range (from 350 nm to 1100 nm.

  12. Cryogenically cooled bent double-Laue monochromator for high-energy undulator X-rays (50-200 keV).

    Science.gov (United States)

    Shastri, S D; Fezzaa, K; Mashayekhi, A; Lee, W K; Fernandez, P B; Lee, P L

    2002-09-01

    A liquid-nitrogen-cooled monochromator for high-energy X-rays consisting of two bent Si(111) Laue crystals adjusted to sequential Rowland conditions has been in operation for over two years at the SRI-CAT sector 1 undulator beamline of the Advanced Photon Source (APS). It delivers over ten times more flux than a flat-crystal monochromator does at high energies, without any increase in energy width (DeltaE/E approximately 10(-3)). Cryogenic cooling permits optimal flux, avoiding a sacrifice from the often employed alternative technique of filtration - a technique less effective at sources like the 7 GeV APS, where considerable heat loads can be deposited by high-energy photons, especially at closed undulator gaps. The fixed-offset geometry provides a fully tunable in-line monochromatic beam. In addition to presenting the optics performance, unique crystal design and stable bending mechanism for a cryogenically cooled crystal under high heat load, the bending radii adjustment procedures are described.

  13. Single-crystal diamond refractive lens for focusing X-rays in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, S.; Baryshev, Sergey; Butler, J. E.; Antipova, O.; Liu, Zunping; Stoupin, S.

    2016-01-01

    The fabrication and performance evaluation of single-crystal diamond refractive X-ray lenses of which the surfaces are paraboloids of revolution for focusing X-rays in two dimensions simultaneously are reported. The lenses were manufactured using a femtosecond laser micromachining process and tested using X-ray synchrotron radiation. Such lenses were stacked together to form a standard compound refractive lens (CRL). Owing to the superior physical properties of the material, diamond CRLs could become indispensable wavefront-preserving primary focusing optics for X-ray free-electron lasers and the next-generation synchrotron storage rings. They can be used for highly efficient refocusing of the extremely bright X-ray sources for secondary optical schemes with limited aperture such as nanofocusing Fresnel zone plates and multilayer Laue lenses.

  14. Single-crystal diamond refractive lens for focusing X-rays in two dimensions.

    Science.gov (United States)

    Antipov, S; Baryshev, S V; Butler, J E; Antipova, O; Liu, Z; Stoupin, S

    2016-01-01

    The fabrication and performance evaluation of single-crystal diamond refractive X-ray lenses of which the surfaces are paraboloids of revolution for focusing X-rays in two dimensions simultaneously are reported. The lenses were manufactured using a femtosecond laser micromachining process and tested using X-ray synchrotron radiation. Such lenses were stacked together to form a standard compound refractive lens (CRL). Owing to the superior physical properties of the material, diamond CRLs could become indispensable wavefront-preserving primary focusing optics for X-ray free-electron lasers and the next-generation synchrotron storage rings. They can be used for highly efficient refocusing of the extremely bright X-ray sources for secondary optical schemes with limited aperture such as nanofocusing Fresnel zone plates and multilayer Laue lenses.

  15. Single Crystal Diamond Refractive Lens for Focusing X-rays in Two Dimensions

    CERN Document Server

    Antipov, S; Butler, J E; Antipova, O; Liu, Z; Stoupin, S

    2015-01-01

    We report the fabrication and performance evaluation of single crystal diamond refractive X-ray lenses with a paraboloid of rotation form factor for focusing X-rays in two dimensions simultaneously. The lenses were manufactured using a femtosecond laser micromachining process and tested using X-ray synchrotron radiation. Such lenses can be stacked together to form a traditional compound refractive lens (CRL). Due to the superior physical properties of the material, diamond CRLs are enabling and indispensable wavefront-preserving primary focusing optics for X-ray free-electron lasers and the next-generation synchrotron storage rings. They can be used for highly efficient refocusing of the extremely bright X-ray sources on secondary optical schemes with limited aperture such as nanofocusing Fresnel zone plates and multilayer Laue lenses.

  16. Patient acceptability of the Tecnis® multifocal intraocular lens

    Directory of Open Access Journals (Sweden)

    Sood P

    2011-03-01

    Full Text Available Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anterior prolate IOL with a diffractive multifocal lens design. The design aims to minimize spherical aberration and improve range of focus. The purpose of this review is to assess patient acceptability of the Tecnis® multifocal intraocular lens.Keywords: Tecnis®, intraocular lens, multifocal, presbyopia 

  17. Optimized Design and Simulation of Composite Fresnel Lens%复合型菲涅耳透镜的优化设计及仿真

    Institute of Scientific and Technical Information of China (English)

    殷丹艳; 王淮生; 骆青君

    2016-01-01

    Objective The efficiency of concentrating photovoltaic power is an important parameter in concentrating solar system.To improve the uniformity of the condensing spot and the photoelectric con-version efficiency,the traditional Fresnel lens was improved by increasing the light transmittance and the uniformity of the surface light intensity of the battery of the composite Fresnel lens.Methods The com-posite lens consists of internal ordinary Fresnel lens annular lens and the external double total internal re-flection annular lens.The internal ordinary Fresnel lens has been divided into odd units,in each of which the width was equal to the width of the battery.The wedge angles in the same unit were equal to each oth-er,thus having sun light refraction with the equal width.The light emitted formed a light band with uni-form intensity,suitable for photovoltaic power generation.Therefore,the sunlight into the lens was su-perposed on the surface of the battery with equal illumination.This method replaced secondary mirrors. In addition,the simulation was realized by making the complex three-dimensional modeling in the Pro En-gineer software and importing the model into TracePro.Results Setting the focal length of the Fresnel lens to 100 mm,the inner radius 36 mm,the corresponding aperture angle 20°,the outer diameter 110 mm, and the corresponding aperture angle 30°,and defining sunlight parameters led to the uniform illumination map The results showed the 91.4% optical efficiency and the 85.9% homogenization.Compared with the common Fresnel lens light distribution map of the same size,the uniformity of focal spot on photovoltaic panels on was significantly increased and the irradiance between the center and the edge had little differ-ence.Conclusion The optimized composite lens has higher uniformity and optical transmission efficiency.%目的:在聚光太阳能系统中,聚光光伏的效率是重要衡量参数之一。为了提高聚光光斑的均匀性以及光

  18. 实现大范围均匀照明的LED透镜二次光学设计%Secondary Optical Design for Light Emitting Diodes Lens with Wide Range and High Uniformity Illumination

    Institute of Scientific and Technical Information of China (English)

    芦佳宁; 余杰; 童玉珍; 张国义

    2012-01-01

    Proposed is a new and accessible method to design LED free-form lens with wide range and high uniformity illumination. Based on the energy conservation law and light refraction Shell's law, free-form lens are calculated by the Matlab programming. CAD software is used to compose the solid model of free-form lens. With optical simulation software Tracepro, ray tracing is used to verify the secondary optical design with the height of lighting source as 3 m and the diameter of circular receiving surface as 10 m. The illumination uniformity higher than 80% is realized.%提出了一种新的、利于实施计算的实现大范围均匀照明的LED灯具透镜设计方法。基于能量守恒定理和光线折射Snell定理,通过Matlab编程计算出自由曲面透镜坐标点。借助CAD软件和光学模拟软件Tracepro,模拟了自由曲面透镜的具体应用,在光源高为3m,接收面直径为10m的圆形照明区域,得到了均匀度达80%以上的照度分布,该设计可以应用在商场、工厂等室内照明灯具上。

  19. Photonic crystal based polarization insensitive flat lens

    Science.gov (United States)

    Turduev, M.; Bor, E.; Kurt, H.

    2017-07-01

    The paper proposes a new design of an inhomogeneous artificially created photonic crystal lens structure consisting of annular dielectric rods to efficiently focus both transverse electric and transverse magnetic polarizations of light into the same focal point. The locations of each individual cell that contains the annular dielectric rods are determined according to a nonlinear distribution function. The inner and outer radii of the annular photonic dielectric rods are optimized with respect to the polarization insensitive frequency response of the transmission spectrum of the lens structure. The physical background of the polarization insensitive focusing mechanism is investigated in both spatial and frequency domains. Moreover, polarization independent wavefront transformation/focusing has been explored in detail by investigating the dispersion relation of the structure. Corresponding phase index distribution of the lens is attained for polarization insensitive normalized frequency range of a/λ  =  0.280 and a/λ  =  0.300, where a denotes the lattice constant of the designed structure and λ denotes the wavelength of the incident light. We show the wave transformation performance and focal point movement dynamics for both polarizations of the lens structure by specially adjusting the length of the structure. The 3D finite-difference time domain numerical analysis is also performed to verifiy that the proposed design is able to focus the wave regardless of polarization into approximately the same focal point (difference between focal distances of both polarizations stays below 0.25λ) with an operating bandwidth of 4.30% between 1476 nm and 1541 nm at telecom wavelengths. The main superiorities of the proposed lens structure are being all dielectric and compact, and having flat front and back surfaces, rendering the proposed lens design more practical in the photonic integration process in various applications such as optical switch

  20. Rose-K versus soper contact lens in keratoconus: A randomized comparative trial

    Directory of Open Access Journals (Sweden)

    Raghav Gupta

    2014-01-01

    Conclusion: Both the contact lens designs provide an equal improvement in visual acuity in patients with Keratoconus. However, Rose-K contact lens provides greater comfort, better quality of vision and requires less chair time compared with the Soper lens and hence may possibly have a greater acceptability.

  1. Evolutionary algorithm for optimization of nonimaging Fresnel lens geometry.

    Science.gov (United States)

    Yamada, N; Nishikawa, T

    2010-06-21

    In this study, an evolutionary algorithm (EA), which consists of genetic and immune algorithms, is introduced to design the optical geometry of a nonimaging Fresnel lens; this lens generates the uniform flux concentration required for a photovoltaic cell. Herein, a design procedure that incorporates a ray-tracing technique in the EA is described, and the validity of the design is demonstrated. The results show that the EA automatically generated a unique geometry of the Fresnel lens; the use of this geometry resulted in better uniform flux concentration with high optical efficiency.

  2. Research on Lens Design Sense Experience Ways in Animation Storyboard Teaching%镜头感设计的情境体验方式在动画分镜教学中的运用探究

    Institute of Scientific and Technical Information of China (English)

    郑群

    2014-01-01

    Lens sense design is an vital link in animation storyboard, in order to make the picture more visual impact, a variety of lens effects need to be reasonable integrated in storyboard design. This article in detail explains how to utilize a shot in the picture storyboard teaching, with scene experience to let students learn easier, and roundly improve the verisimilitude of visual effects in works.%镜头感的设计是动画分镜中至关重要的一环,为了使画面更具视觉冲击力,需要将多种镜头效果合理融入分镜设计中,本文将详细阐述如何将镜头感灵活运用在画面分镜教学中,并通过情景体验方式使学生更易掌握,最终使作品在视觉效果的灵动性上得以全面提升。

  3. Optical Design of F- theta Lens for Dual Wavelength Selective Laser Melting%双波长选区激光熔化成形中F-theta镜头光学设计

    Institute of Scientific and Technical Information of China (English)

    冯联华; 张宁; 曹洪忠; 徐熙平; 段宣明

    2016-01-01

    F-theta lens is an important unit for selective laser melting (SLM) manufacture and generally use a single wavelength as the light source. The dual wavelength f-theta lens has not been used in SLM manufacture. In order to improve the SLM formability, we present the design of the f-theta lens satisfied coaxial dual wavelength SLM manu-facture. Linear scanning was achieved by introducing negative distortion, and chromatic aberration correction was achieved by choosing appropriate glass material and the structural optimization. It is composed of three pieces of spheri-cal lenses. In the scan area of 120mm × 120mm, the focal spots for 532nm laser and 1080nm laser are smaller than 30μm and 60μm,respectively. The lateral color of the designed f-theta lens is less than 1μm between the two wave-lengths,which meet the high precision application requirements of dual wavelength selective laser melting.%在选区激光熔化成形设备中,F-theta镜头是其重要的组成单元,一般采用单一波长作为光源。为了改善选区激光熔化成形性能,首次设计了由三片球面透镜组成的用于共轴双波长选区激光熔化成形的f-theta镜头。通过引入负畸变实现线性扫描,并选择合适玻璃材料、结构设计来消除色差。在扫描面积为120mm×120mm范围内,适用激光波长为532nm和1080nm,对这两波长激光的聚焦光斑分别小于30μm和60μm,横向色差分离小于1μm,满足高精度双波长激光同时共轴选区熔化成形的应用需求。

  4. Fundamentals of concentric lens systems synthesis

    Science.gov (United States)

    Ezhova, Kseniia; Zverev, Victor; Tochilina, Tatiana; Tymoshchuk, Irina

    2016-09-01

    Introduction of coefficients defining the relationship of the radii of curvature of the surfaces of concentric optical systems, allowed the transformation of the obtained analytical relations in a system of two equations with two unknowns. It is shown that the existence of the solution of the system of equations determined by the optical constants of the selected lens material. The results of the analysis of the conditions of the chromatic aberration correction position and the sequence of obtaining of the system equations define the theoretical basis of the engineering method of parametric synthesis of concentric lens systems. Application of the developed method is illustrated by examples of calculation particular systems design build.

  5. Scleral Lens Prescription and Management Practices: The SCOPE Study.

    Science.gov (United States)

    Harthan, Jennifer; Nau, Cherie B; Barr, Joseph; Nau, Amy; Shorter, Ellen; Chimato, Nicolette T; Hodge, David O; Schornack, Muriel M

    2017-04-06

    To assess current scleral lens prescription and management practices by conducting an international online survey of eye care providers. The SCOPE (Scleral Lenses in Current Ophthalmic Practice: an Evaluation) study group designed and administered an online survey regarding current scleral lens prescription and management practices. The survey was open from January 15 to March 31, 2015, and generated 723 responses from individuals who had fit at least 5 patients with scleral lenses. Respondents (n=663) prescribed scleral lenses that ranged from 15 to 17 mm in diameter (65%), smaller than 15 mm (18%), and larger than 18 mm (17%). More than 50 lens designs were identified. Average daily wearing time of 11.8 hr was consistent across 651 respondents, and 475/651 (73%) recommended midday removal on some, most, or all days. Most respondents recommended nonpreserved saline to fill the bowl of the lens before application (single-use vials, 392/653 [60%]; bottled products, 372/653 [57%]). A hydrogen peroxide-based disinfection system was the most commonly recommended care product (397/651 [61%]). A reasonable degree of consensus exists regarding some aspects of scleral lens prescription and management (average lens diameter, daily wearing time, and use of nonpreserved products for lens application). Further study is needed to develop evidence-based guidelines for scleral lens prescription and management.

  6. Design of an X-ray detecting system based on square polycapillary X-ray lens%一种基于方形多毛细管透镜的X射线探测系统设计

    Institute of Scientific and Technical Information of China (English)

    易龙涛; 孙天希; 王锴; 彭诗棋; 韩悦; 张爽; 刘志国

    2016-01-01

    An X-ray detecting system based on square polycapillary X-ray lens was designed, which had a very small X-ray collection angle. The square polycapillary X-ray lens is an X-ray control device based on total X-ray reflection. The X-ray in large range can be focused on an X-ray CCD detector by the square polycapillary X-ray lens. By measuring the transmission characteristic of the square polycapillary X-ray lens and creating the data modelling, the data detected by the X-ray CCD detector could be corrected and the information of the X-ray in the entry end of the square polycapillary X-ray lens could be restored. The transmission characteristic of the square polycapillary X-ray lens was simulated by the light trajectory tracking method. The results show that this system is suitable for large area X-ray imaging when the energy of the X-ray is lower than 20 keV. It is also suitable for collecting X-ray to improve the detection efficiency when the energy of the X-ray is lower than 14.6 keV. The above characteristics show that this system is not only suitable for some special detecting such as pulsar navigation, but also suitable for normal X-ray detecting.%设计了一种基于方形多毛细管X射线透镜的X射线探测系统,该系统具有较小的X射线收集角。方形多毛细管X射线透镜是一种基于X射线全反射的X射线调控器件,可将大面积范围内的X射线汇聚至X射线CCD探测器。通过测定X射线在方形多毛细管X射线透镜中的传输特性、建立数据模型,可校正X射线CCD所测数据并还原透镜入口端的入射X射线信息。通过光线轨迹追踪方法模拟了方形多毛细管X射线透镜的传输特性。结果表明,该系统适合探测能量低于21.5 keV的X射线,用于大面积成像;也适合探测能量低于14.6 keV的X射线,用于提高探测效率。该系统不仅可用于诸如X射线脉冲星导航等特殊应用,也可用于常规X射线探测。

  7. Solar powered desalination system using Fresnel lens

    Science.gov (United States)

    Sales, M. T. B. F.

    2016-11-01

    The Philippines is surrounded by coastal areas and these areas can be a potential source for potable water. This study aims to design and construct a solar powered desalination system using Fresnel lens. The experimental study was conducted using polluted salt water for the sample and desalination was carried out using the designed system. The desalination system was composed of the solar concentrator, solar still and the condenser system. The Fresnel lens was made of acrylic plastic and was an effective solar concentrator. Solar stills made of dark colored glass bottles were effective in absorbing the solar energy. The condenser system made of polybutylene and polystyrene were effective in condensing the vapor at ambient temperature. The shortest time of vaporization of the salt water was at 293 sec and the optimum angle of position of the lens was 36.42°. The amount of condensate collected was directly proportional to the amount of salt water in the solar still. The highest mean efficiency of the designed set-up was 34.82%. The water produced by the solar powered desalination system using Fresnel lens passed the standards set by WHO (World Health Organization) for drinking water.

  8. Thin Lens Ray Tracing.

    Science.gov (United States)

    Gatland, Ian R.

    2002-01-01

    Proposes a ray tracing approach to thin lens analysis based on a vector form of Snell's law for paraxial rays as an alternative to the usual approach in introductory physics courses. The ray tracing approach accommodates skew rays and thus provides a complete analysis. (Author/KHR)

  9. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Lens Use May 31, 2016 Is El Niño Making Your Allergies Worse? May 16, 2016 More Eye ... EyeSmart Embed EyeSmart videos on your website Promotional materials for eye health observances EyeSmart resources are also ...

  10. Comparison of Strong Gravitational Lens Model Software II. HydraLens: Computer-Assisted Strong Gravitational Lens Model Generation and Translation

    CERN Document Server

    Lefor, Alsn T

    2015-01-01

    The behavior of strong gravitational lens model software in the analysis of lens models is not necessarily consistent among the various software available, suggesting that the use of several models may enhance the understanding of the system being studied. Among the publicly available codes, the model input files are heterogeneous, making the creation of multiple models tedious. An enhanced method of creating model files and a method to easily create multiple models, may increase the number of comparison studies. HydraLens simplifies the creation of model files for four strong gravitational lens model software packages, including Lenstool, Gravlens/Lensmodel, glafic and PixeLens, using a custom designed GUI for each of the four codes that simplifies the entry of the model for each of these codes, obviating the need for user manuals to set the values of the many flags and in each data field. HydraLens is designed in a modular fashion, which simplifies the addition of other strong gravitational lens codes in th...

  11. Magnifying lens for 800 MeV proton radiography.

    Science.gov (United States)

    Merrill, F E; Campos, E; Espinoza, C; Hogan, G; Hollander, B; Lopez, J; Mariam, F G; Morley, D; Morris, C L; Murray, M; Saunders, A; Schwartz, C; Thompson, T N

    2011-10-01

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  12. Dielectric Optical-Controlled Magnifying Lens by Nonlinear Negative Refraction

    CERN Document Server

    Cao, Jianjun; Zheng, Yuanlin; Chen, Xianfeng; Liang, Xiaogan; Wan, Wenjie

    2014-01-01

    A simple optical lens plays an important role for exploring the microscopic world in science and technology by refracting light with tailored spatially varying refractive index. Recent advancements in nanotechnology enable novel lenses, such as, superlens, hyperlens, Luneburg lens, with sub-wavelength resolution capabilities by specially designing materials' refractive indices with meta-materials and transformation optics. However, these artificially nano/micro engineered lenses usually suffer high losses from metals and are highly demanding in fabrication. Here we experimentally demonstrate for the first time a nonlinear dielectric magnifying lens using negative refraction by degenerate four-wave mixing in a plano-concave glass slide, obtaining magnified images. Moreover, we transform a nonlinear flat lens into a magnifying lens by introducing transformation optics into nonlinear regime, achieving an all-optical controllable lensing effect through nonlinear wave mixing, which may have many potential applicat...

  13. Design of antimagnetic lens window of mine-used infrared thermometers%矿用红外测温仪镜头窗口防磁设计

    Institute of Scientific and Technical Information of China (English)

    李立明; 陈影

    2012-01-01

    矿用高压供电设备温度过高时容易发生故障,由于供电设备周围存在大量的感应磁场,影响红外测温仪测量的准确性。红外测温仪的屏蔽外壳的材料为硅钢,镜头窗口处的电磁泄漏是电磁屏蔽效能下降的主要原因。在镜头窗口贴上ITO膜后,仿真得出的屏蔽效能达到了A级50dB以上,满足了屏蔽效能要求,提高了温度测量的准确性。%Overhigh of the hot points on the high-voltage power supply equipment used in the mine easily brings about accidents,and since there are lots of induced magnetic fields around the power supply equipments,the accuracy of the infrared thermometer can not be guaranteed.Silicon steel was selected as the shielding enclosure material of the infrared thermometer,the electromagnetic leakage at the lens window was the main cause of decrease in electromagnetic shielding capacity.After applying ITO film on the lens window,simulated shielding capacity reached 50 dB of grade A,which met the requirement of shielding capacity and improved the accuracy of the temperature measurement.

  14. Finite Element Analysis of the LOLA Receiver Telescope Lens

    Science.gov (United States)

    Matzinger, Elizabeth

    2007-01-01

    This paper presents the finite element stress and distortion analysis completed on the Receiver Telescope lens of the Lunar Orbiter Laser Altimeter (LOLA). LOLA is one of six instruments on the Lunar Reconnaissance Orbiter (LRO), scheduled to launch in 2008. LOLA's main objective is to produce a high-resolution global lunar topographic model to aid in safe landings and enhance surface mobility in future exploration missions. The Receiver Telescope captures the laser pulses transmitted through a diffractive optical element (DOE) and reflected off the lunar surface. The largest lens of the Receiver Telescope, Lens 1, is a 150 mm diameter aspheric lens originally designed to be made of BK7 glass. The finite element model of the Receiver Telescope Lens 1 is comprised of solid elements and constrained in a manner consistent with the behavior of the mounting configuration of the Receiver Telescope tube. Twenty-one temperature load cases were mapped to the nodes based on thermal analysis completed by LOLA's lead thermal analyst, and loads were applied to simulate the preload applied from the ring flexure. The thermal environment of the baseline design (uncoated BK7 lens with no baffle) produces large radial and axial gradients in the lens. These large gradients create internal stresses that may lead to part failure, as well as significant bending that degrades optical performance. The high stresses and large distortions shown in the analysis precipitated a design change from BK7 glass to sapphire.

  15. Design of wide-angle projection lens for 4k digital projector%4k 数字放映机广角放映镜头的设计

    Institute of Scientific and Technical Information of China (English)

    刘宵婵; 陈琛; 宋涛; 张禹; 李维善; 刘红军

    2014-01-01

    To meet the need of 4k short distance movie projection ,a wide-angle projection lens was designed ,which is suitable for projectors with three-digital-micromirror-device (DMD) chips .The largest projection ratio could be 0 .75∶1 ,the relative aperture is 1/2 .2 ,the invert-ed telephoto ratio is 4 .6∶1 .At the Nyquist frequency of 66lp/mm ,the resolution of center field is 0 .42 ,and the resolution of marginal field is 0 .25 .T he max lateral chromatic aberration is 3 .7 μm ,w hich is less than 0 .5 pixel ,and the max distortion is 2 .5% .T he feature of invert-ed telephoto was deeply analyzed ,and the methods for choosing structure ,distributing focal power and calculating key parameters were provided in the paper ,additional ,the issues nee-ding pay attention during aberration correction were contained .Finally ,a wide-angle projec-tion lens with high resolution which could meet all the indices was designed ,besides that ,the lens has the feature of easy structure ,low cost and high quality .%为满足4k电影的短距离放映需求,设计一款广角放映镜头,可适配于采用三芯片DMD技术的放映机,最大投射比可达0.75∶1,相对孔径为1/2.2,反远比为4.6∶1,在66lp/mm的Nyquist频率处,MTF值为0.42,边缘视场MTF值为0.25。最大横向色差为3.7μm<0.5pixel,最大畸变为2.5%。分析了反远距形式的特点,给出了合理选型、分配光焦度和计算关键技术参数的方法,以及像差校正过程中应注意的问题。最终设计出了符合设计指标的具有高分辨率的广角放映镜头,该镜头结构简单、成本低。

  16. A single-pixel wireless contact lens display

    Science.gov (United States)

    Lingley, A. R.; Ali, M.; Liao, Y.; Mirjalili, R.; Klonner, M.; Sopanen, M.; Suihkonen, S.; Shen, T.; Otis, B. P.; Lipsanen, H.; Parviz, B. A.

    2011-12-01

    We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists of an antenna, a 500 × 500 µm2 silicon power harvesting and radio integrated circuit, metal interconnects, insulation layers and a 750 × 750 µm2 transparent sapphire chip containing a custom-designed micro-light emitting diode with peak emission at 475 nm, all integrated onto a contact lens. The display can be powered wirelessly from ~1 m in free space and ~2 cm in vivo on a rabbit. The display was tested on live, anesthetized rabbits with no observed adverse effect. In order to extend display capabilities, design and fabrication of micro-Fresnel lenses on a contact lens are presented to move toward a multipixel display that can be worn in the form of a contact lens. Contact lenses with integrated micro-Fresnel lenses were also tested on live rabbits and showed no adverse effect.

  17. Remote cooling by a novel thermal lens with anisotropic positive thermal conductivity

    Science.gov (United States)

    Sun, Fei; He, Sailing

    2017-01-01

    A novel thermal lens that can achieve a remote cooling effect is designed by transformation thermodynamics. The effective distance between the separate hot source and cold source is shortened by our shelled thermal lens without any negative thermal conductivity. Numerical simulations verify the performance of our thermal lens. Based on the effective medium theory, we also propose a practical way to realize our lens using two-layered isotropic thermal media that are both found in nature. The proposed thermal lens will have potential applications in remote temperature control and in creating other thermal illusions.

  18. Laue crystal structure of Shewanella oneidensis cytochrome c nitrite reductase from a high-yield expression system

    Energy Technology Data Exchange (ETDEWEB)

    Youngblut, Matthew; Judd, Evan T.; Srajer, Vukica; Sayyed, Bilal; Goelzer, Tyler; Elliott, Sean J.; Schmidt, Marius; Pacheco, A. Andrew (UW); (UC); (BU)

    2012-09-11

    The high-yield expression and purification of Shewanella oneidensis cytochrome c nitrite reductase (ccNiR) and its characterization by a variety of methods, notably Laue crystallography, are reported. A key component of the expression system is an artificial ccNiR gene in which the N-terminal signal peptide from the highly expressed S. oneidensis protein 'small tetraheme c' replaces the wild-type signal peptide. This gene, inserted into the plasmid pHSG298 and expressed in S. oneidensis TSP-1 strain, generated approximately 20 mg crude ccNiR per liter of culture, compared with 0.5-1 mg/L for untransformed cells. Purified ccNiR has nitrite and hydroxylamine reductase activities comparable to those previously reported for Escherichia coli ccNiR, and is stable for over 2 weeks in pH 7 solution at 4 C. UV/vis spectropotentiometric titrations and protein film voltammetry identified five independent one-electron reduction processes. Global analysis of the spectropotentiometric data also allowed determination of the extinction coefficient spectra for the five reduced ccNiR species. The characteristics of the individual extinction coefficient spectra suggest that, within each reduced species, the electrons are distributed among the various hemes, rather than being localized on specific heme centers. The purified ccNiR yielded good-quality crystals, with which the 2.59-{angstrom}-resolution structure was solved at room temperature using the Laue diffraction method. The structure is similar to that of E. coli ccNiR, except in the region where the enzyme interacts with its physiological electron donor (CymA in the case of S. oneidensis ccNiR, NrfB in the case of the E. coli protein).

  19. Image registration reveals central lens thickness minimally increases during accommodation

    Directory of Open Access Journals (Sweden)

    Schachar RA

    2017-09-01

    Full Text Available Ronald A Schachar,1 Majid Mani,2 Ira H Schachar31Department of Physics, University of Texas at Arlington, Arlington, TX, 2California Retina Associates, El Centro, 3Byers Eye Institute of Stanford University, Palo Alto, CA, USAPurpose: To evaluate anterior chamber depth, central crystalline lens thickness and lens curvature during accommodation.Setting: California Retina Associates, El Centro, CA, USA.Design: Healthy volunteer, prospective, clinical research swept-source optical coherence biometric image registration study of accommodation.Methods: Ten subjects (4 females and 6 males with an average age of 22.5 years (range: 20–26 years participated in the study. A 45° beam splitter attached to a Zeiss IOLMaster 700 (Carl Zeiss Meditec Inc., Jena, Germany biometer enabled simultaneous imaging of the cornea, anterior chamber, entire central crystalline lens and fovea in the dilated right eyes of subjects before, and during focus on a target 11 cm from the cornea. Images with superimposable foveal images, obtained before and during accommodation, that met all of the predetermined alignment criteria were selected for comparison. This registration requirement assured that changes in anterior chamber depth and central lens thickness could be accurately and reliably measured. The lens radii of curvatures were measured with a pixel stick circle.Results: Images from only 3 of 10 subjects met the predetermined criteria for registration. Mean anterior chamber depth decreased, −67 µm (range: −0.40 to −110 µm, and mean central lens thickness increased, 117 µm (range: 100–130 µm. The lens surfaces steepened, anterior greater than posterior, while the lens, itself, did not move or shift its position as appeared from the lack of movement of the lens nucleus, during 7.8 diopters of accommodation, (range: 6.6–9.7 diopters.Conclusion: Image registration, with stable invariant references for image correspondence, reveals that during accommodation a

  20. Optical design of two-axes parabolic trough collector and two-section Fresnel lens for line-to-spot solar concentration.

    Science.gov (United States)

    Ramírez, Carlos; León, Noel; García, Héctor; Aguayo, Humberto

    2015-06-01

    Solar tracking concentrators are optical systems that collect the solar energy flux either in a line or spot using reflective or refractive surfaces. The main problem with these surfaces is their manufacturing complexity, especially at large scales. In this paper, a line-to-spot solar tracking concentrator is proposed. Its configuration allows for a low-cost solar concentrator system. It consists of a parabolic trough collector (PTC) and a two-section PMMA Fresnel lens (FL), both mounted on a two-axis solar tracker. The function of the PTC is to reflect the incoming solar radiation toward a line. Then, the FL, which is placed near the focus, transforms this line into a spot by refraction. It was found that the system can achieve a concentration ratio of 100x and concentrate an average solar irradiance of 518.857W/m2 with an average transmittance of 0.855, taking into account the effect of the chromatic aberration.

  1. Research of the long-focus Maksutov telephoto lens

    Science.gov (United States)

    Tarasov, I. P.; Tsyganok, E. A.

    2016-04-01

    The article presents the research result and the optical design of long-focus telephoto lens for photo shooting by the academician Maksutov's scheme. It shows a review of lenses for photo shooting on the market today, and also an analysis of the correctional possibilities which is based on the scheme is presented; studied long-focus telephoto lens is compared with its closest analog, the calculation of a new telephoto lens with higher image quality is made on the basis of that comparison.

  2. Adaptive neuro-fuzzy estimation of optimal lens system parameters

    Science.gov (United States)

    Petković, Dalibor; Pavlović, Nenad T.; Shamshirband, Shahaboddin; Mat Kiah, Miss Laiha; Badrul Anuar, Nor; Idna Idris, Mohd Yamani

    2014-04-01

    Due to the popularization of digital technology, the demand for high-quality digital products has become critical. The quantitative assessment of image quality is an important consideration in any type of imaging system. Therefore, developing a design that combines the requirements of good image quality is desirable. Lens system design represents a crucial factor for good image quality. Optimization procedure is the main part of the lens system design methodology. Lens system optimization is a complex non-linear optimization task, often with intricate physical constraints, for which there is no analytical solutions. Therefore lens system design provides ideal problems for intelligent optimization algorithms. There are many tools which can be used to measure optical performance. One very useful tool is the spot diagram. The spot diagram gives an indication of the image of a point object. In this paper, one optimization criterion for lens system, the spot size radius, is considered. This paper presents new lens optimization methods based on adaptive neuro-fuzzy inference strategy (ANFIS). This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated.

  3. Flat acoustic lens by acoustic grating with curled slits

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Pai; Xiao, Bingmu; Wu, Ying, E-mail: ying.wu@kaust.edu.sa

    2014-10-03

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry–Perot resonance. - Highlights: • Expression of transmission coefficient of an acoustic grating with curled slits. • Non-dispersive and tunable effective medium parameters for the acoustic grating. • A flat acoustic focusing lens with gradient index by using the acoustic grating.

  4. Anisotropic and omnidirectional focusing in Luneburg lens structure with gradient photonic crystals

    Science.gov (United States)

    Zhao, Yuan-Yuan; Zhang, Yong-Liang; Zheng, Mei-Ling; Dong, Xian-Zi; Duan, Xuan-Ming; Zhao, Zhen-Sheng

    2017-01-01

    We propose a flexible design for implementation of the Luneburg lens with gradient photonic crystals. The full-wave simulation results demonstrate the excellent performance of omnidirectional focusing of the designed Luneburg lens over a broad frequency band, and firstly exhibit anisotropic focusing in the designed Luneburg lens with a specific frequency band. In this study, our effort is focused on figuring out the operating wavelength range where the effective medium approximation theory is applicable, and the mechanism for generating anisotropic and omnidirectional focusing in Luneburg lens structure.

  5. Test results of high-precision large cryogenic lens holders

    Science.gov (United States)

    Gal, C.; Reutlinger, A.; Boesz, A.; Leberle, T.; Mottaghibonab, A.; Eckert, P.; Dubowy, M.; Gebler, H.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

    2012-09-01

    For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system [1]. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (?170 mm) at cryogenic temperatures (150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that are mounted in a separate lens barrel design. Each lens has its separate mechanical interface to the lens barrel, the so called adaption ring. The performance of the lens holder design is verified by adapted test equipment and test facility including an optical metrology system. The characterization of the lens deformation and displacement (decenter, tilt) due to mechanical loads of the holder itself as well as thermally induced loads are driven by the required submicron precision range and the operational thermal condition. The surface deformation of the lens and its holder is verified by interferometric measurements, while tilt and position accuracy are measured by in-situ fibre based distance sensors. The selected distance measurement sensors have the capability to measure in a few mm range with submicron resolution in ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance: impacts such as temperature fluctuation, surface roughness, surface reflectivity, straylight effects, etc. on the measured distance are carefully calibrated. Inbuilt thermal expansion effects of the fibre sensors are characterized and proven with lens dummy with quasi zero CTE. The paper presents the test results and measured performance of the high precision large cryogenic lens holders attained by the metrology system. These results are presented on behalf of the EUCLID consortium.

  6. Hybrid Refractive-Diffractive Achromatic System Design with Photon Sieve-Lens Combination%光子筛-透镜组合的折衍混合消色差系统设计

    Institute of Scientific and Technical Information of China (English)

    何渝; 赵立新; 唐燕; 陈铭勇; 朱江平

    2012-01-01

    Photon sieve is a diffractive optical element with large chromatic aberration, which is not suitable for imaging in wide spectral. The focal length of photon sieve decreases when the incident wavelength increases, while the focal length of positive refractive lens increases when the incident wavelength increases. The design applying the method of hybrid refractive-diffractive into the photon sieve achromatic is proposed. These opposite dispersive characteristics are used in this method. A plano-convex len is placed close to side of a photon sieve in order to achieve achromatic design. Then the achromatic system is designed in the visible spectrum. The analysis shows that the system is achromatic and has a certain ability of secondary spectrum correction. The relative error between focal lengths of achromatic wavelength and centre wavelength is 0. 33%. The imaging spectral bandwidth is 20 nm. Compared with ordinary single photon sieve, the design broadens the imaging spectrum range. Compared with the hybrid refractive-diffractive system using zone plate, a smaller focusing spot can be achieved.%光子筛作为一种衍射光学元件,具有较大的色散,不适用于宽光谱成像.光子筛的焦距随着入射波长的增大而减小,而正的折射透镜焦距随着入射波长的增大而增大.应用了折衍混合方法进行光子筛消色差的设计.该设计利用二者相反的色散特性,在光子筛的一侧紧密放置一平凸透镜,从而实现光子筛的消色差设计.并针对可见光光谱进行了设计,分析表明该方法能够实现消色差,且具有一定校正二级光谱的能力,消色差波长与中心波长处焦距相对误差为0.33%,成像光谱带宽为20 nm.与普通单个光子筛相比,该方法有效拓宽了光子筛的成像光谱范围.与使用波带片的折衍混合系统相比,聚焦光斑更小.

  7. Patient acceptability of the Tecnis® multifocal intraocular lens

    OpenAIRE

    Woodward, Maria; Sood,Priyanka

    2011-01-01

    Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL) designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anter...

  8. A stereoscopic lens for digital cinema cameras

    Science.gov (United States)

    Lipton, Lenny; Rupkalvis, John

    2015-03-01

    Live-action stereoscopic feature films are, for the most part, produced using a costly post-production process to convert planar cinematography into stereo-pair images and are only occasionally shot stereoscopically using bulky dual-cameras that are adaptations of the Ramsdell rig. The stereoscopic lens design described here might very well encourage more live-action image capture because it uses standard digital cinema cameras and workflow to save time and money.

  9. A Broadband Bessel Beam Launcher Using Metamaterial Lens.

    Science.gov (United States)

    Qi, Mei Qing; Tang, Wen Xuan; Cui, Tie Jun

    2015-06-30

    An approach of generating broadband Bessel beams is presented. The broadband Bessel beams are produced by a gradient index (GRIN) metamaterial lens illuminated by broadband waveguide antenna. The metamaterial lens is constructed with multi-layered structure and each layer is composed of GRIN metamaterials. The metamaterials are designed as dielectric plates printed with metallic patterns in the center region and drilled by air holes near the edge, which operate in wide band. The metamaterial lens serves as a convertor which transforms the spherical beams emitted from feed into conical beams. The conical beams form quasi-Bessel beams in the near-field region. The aperture diameter of the GRIN lens is much larger than the operating wavelength to guarantee the transformation. In principle, this kind of metamaterial lens can produce Bessel beams at arbitrary distance by designing the refractive-index distribution. To verify the approach, we have designed, fabricated and tested a metamaterial lens. Full-wave simulation and experiment results have proved that the generated Bessel beams can be maintained in distance larger than 1 meter within a ranging from 12 GHz to 18 GHz.

  10. [Intraocular lens implantation in developmental lens disorders in children].

    Science.gov (United States)

    Kanigowska, Krystyna; Grałek, Mirosława; Kepa, Beata; Chipczyńska, Barbara

    2009-01-01

    The pediatric cataract surgery in eyes with developmental disorders, stay with still considerable challenge. At children, the lasting vision development extorts necessity quick settlement of refraction defect formed after operation. The intraocular lens old boy with cataract in microspherophakia and 12 years old boy with cataract in lens with coloboma. One-piece flexible and rigid PMMA intraocular lens was placed with success at posterior chamber without scleral fixations and without using capsular tension ring in this cases. After 3 years of observation there were no decentration or dislocation of intraocular lens in both children. Authors concluded that in some cases posterior chamber intraocular lens implantation despite defective zonular or capsular support, can make up the effective method of surgical treatment without risk of early dislocation.

  11. Single-shot full strain tensor determination with microbeam X-ray Laue diffraction and a two-dimensional energy-dispersive detector.

    Science.gov (United States)

    Abboud, A; Kirchlechner, C; Keckes, J; Conka Nurdan, T; Send, S; Micha, J S; Ulrich, O; Hartmann, R; Strüder, L; Pietsch, U

    2017-06-01

    The full strain and stress tensor determination in a triaxially stressed single crystal using X-ray diffraction requires a series of lattice spacing measurements at different crystal orientations. This can be achieved using a tunable X-ray source. This article reports on a novel experimental procedure for single-shot full strain tensor determination using polychromatic synchrotron radiation with an energy range from 5 to 23 keV. Microbeam X-ray Laue diffraction patterns were collected from a copper micro-bending beam along the central axis (centroid of the cross section). Taking advantage of a two-dimensional energy-dispersive X-ray detector (pnCCD), the position and energy of the collected Laue spots were measured for multiple positions on the sample, allowing the measurement of variations in the local microstructure. At the same time, both the deviatoric and hydrostatic components of the elastic strain and stress tensors were calculated.

  12. Projection lens design of wide band dynamic infrared scene simulator with digital micromirror device%宽波段DMD动态红外景象仿真器投影光学系统设计

    Institute of Scientific and Technical Information of China (English)

    党东妮; 季轶群; 沈为民

    2012-01-01

    宽波段红外景象仿真器可用于内场评价和验证中波/长波红外双波段成像仪.详细介绍了基于数字微镜器件(DMD)的动态红外景象仿真器的组成和工作原理.重点介绍了覆盖中波和长波红外的宽波段红外投影光学系统的指标要求、设计思想和设计结果.基于离轴三反射镜系统设计的系统,具有无色差、适用波段宽、相对孔径大、结构较紧凑、成像质量好等优点.根据待测设备要求,设计了一款口径100、相对孔径F/2.84、全面视场角4.4°、成像质量接近于衍射极限的宽波段投影光学系统.%Wide band infrared scene simulator can be used to evaluate and verify the performance of middle (MWIR) and/or long(LWIR) wavelength infrared dual-band imagers. The construction and work principle of dynamic infrared scene simulator based digital micromirror device (DMD) were introduced in detail. The required performance, design idea and result of its projection lens covering MWTR and LWIR bands were analyzed and reported. The designed optical system was based on off-axial three-mirror system and had the advantages of achromatism, wide usable band, high speed, relative compactness and good imaging quality. According to the requirement of tested instrument, a projection lens was designed, which had 3-12 |xm of wide band, 100 mm of entrance pupil diameter, 2.84 of F-No, 284 mm of effective focal length and 4.4 degrees of area full field of view, and approached its diffraction-limited performance.

  13. Rose-K contact lens for keratoconus

    Directory of Open Access Journals (Sweden)

    Jain Arun

    2007-01-01

    Full Text Available Aim: To report clinical experience and the comparative value of axial and instantaneous topography data in fitting Rose-K design contact lenses in moderate and severe keratoconus. Materials and Methods: Thirty-eight eyes (of 23 patients with keratoconus were fitted with Rose-K design contact lenses and followed up for at least six months or more. Visual acuity with habitual vision correction available was measured. Axial and instantaneous topography maps for each eye were recorded. Contact lens wear comfort was graded on a ten point rating scale every three months. Results: Fourteen (100% moderate keratoconus eyes (average Sim K 48.61 ± 1.24D and 23 of 24 (96% of severe keratoconus eyes (average Sim K 60.88 ± 5.31D were successfully fitted with the Rose-K lenses. Final fit contact lenses in severe keratoconus had statistically significant steeper base curves compared to average axial corneal curvature than in moderate keratoconus eyes. Average simulated corneal curvature on axial maps predicted final fit contact lens base curves significantly better than on instantaneous maps. Thirty-three of the 37 eyes fitted with contact lenses maintained wear comfort over average follow up period of 13 ± 3.5 months. Conclusions: Rose-K design rigid contact lenses are successful in visually rehabilitating 100% of moderate and 96% of severe keratoconus eyes. Most patients (90% maintained contact lens wear comfort. Corneal curvature on axial maps is a better predictive of base curve of final fit contact lens.

  14. Critical Assessment of Correction Methods for Fisheye Lens Distortion

    Science.gov (United States)

    Liu, Y.; Tian, C.; Huang, Y.

    2016-06-01

    A fisheye lens is widely used to create a wide panoramic or hemispherical image. It is an ultra wide-angle lens that produces strong visual distortion. The distortion modeling and estimation of the fisheye lens are the crucial step for fisheye lens calibration and image rectification in computer vision and close-range photography. There are two kinds of distortion: radial and tangential distortion. Radial distortion is large for fisheye imaging and critical for the subsequent image processing. Although many researchers have developed calibration algorithms of radial distortion of fisheye lens, quantitative evaluation of the correction performance has remained a challenge. This is the first paper that intuitively and objectively evaluates the performance of five different calibration algorithms. Upto- date research on fisheye lens calibration is comprehensively reviewed to identify the research need. To differentiate their performance in terms of precision and ease-using, five methods are then tested using a diverse set of actual images of the checkerboard that are taken at Wuhan University, China under varying lighting conditions, shadows, and shooting angles. The method of rational function model, which was generally used for wide-angle lens correction, outperforms the other methods. However, the one parameter division model is easy for practical use without compromising too much the precision. The reason is that it depends on the linear structure in the image and requires no preceding calibration. It is a tradeoff between correction precision and ease-using. By critically assessing the strengths and limitations of the existing algorithms, the paper provides valuable insight and guideline for future practice and algorithm development that are important for fisheye lens calibration. It is promising for the optimal design of lens correction models that are suitable for the millions of portable imaging devices.

  15. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device.

    Science.gov (United States)

    Abboud, A; Kirchlechner, C; Send, S; Micha, J S; Ulrich, O; Pashniak, N; Strüder, L; Keckes, J; Pietsch, U

    2014-11-01

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots' energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the "3D detector method" as a promising tool for material investigations to separate bending and strain for technical materials.

  16. Effect of crystalline lens surfaces and refractive index on image quality by model simulation analysis

    Institute of Scientific and Technical Information of China (English)

    Meimei Kong; Zhishan Gao; Lei Chen; Xinhua Li

    2008-01-01

    The surfaces and refractive index of crystalline lens play an important role in the optical performance of human eye.On the basis of two eye models,which are widely applied at present,the effect of lens surfaces and its refractive index distribution on optical imaging is analyzed with the optical design software ZEMAX (Zemax Development Co.,San Diego,USA).The result shows that good image quality can be provided by the aspheric lens surfaces or (and) the gradient-index (GRIN) distribution.It has great potential in the design of intraocular lens (IOL).The eye models with an intraocular implantation are presented.

  17. Dielectric Optical-Controllable Magnifying Lens by Nonlinear Negative Refraction

    Science.gov (United States)

    Cao, Jianjun; Shang, Ce; Zheng, Yuanlin; Feng, Yaming; Chen, Xianfeng; Liang, Xiaogan; Wan, Wenjie

    2015-01-01

    A simple optical lens plays an important role for exploring the microscopic world in science and technology by refracting light with tailored spatially varying refractive indices. Recent advancements in nanotechnology enable novel lenses, such as, superlens and hyperlens, with sub-wavelength resolution capabilities by specially designed materials’ refractive indices with meta-materials and transformation optics. However, these artificially nano- or micro-engineered lenses usually suffer high losses from metals and are highly demanding in fabrication. Here, we experimentally demonstrate, for the first time, a nonlinear dielectric magnifying lens using negative refraction by degenerate four-wave mixing in a plano-concave glass slide, obtaining magnified images. Moreover, we transform a nonlinear flat lens into a magnifying lens by introducing transformation optics into the nonlinear regime, achieving an all-optical controllable lensing effect through nonlinear wave mixing, which may have many potential applications in microscopy and imaging science. PMID:26149952

  18. Ultra-precision molding of chalcogenide glass aspherical lens

    Science.gov (United States)

    Zhang, Feng; Wang, Zhibin; Zhang, Yunlong; Su, Ying; Guo, Rui; Xu, Zengqi; Liu, Xuanmin

    2016-10-01

    With the development of infrared optical systems in military and civil areas, chalcogenide glass aspherical lens possess some advantages, such as large infrared transmission, good thermal stability performance and image quality. Aspherical lens using chalcogenide glass can satisfy the requirements of modern infrared optical systems. Therefore, precision manufacturing of chalcogenide glass aspheric has received more and more attention. The molding technology of chalcogenide glass aspheric has become a research hotspot, because it can achieve mass and low cost manufacturing. The article of molding technology is focusing on a kind of chalcogenide glass aspherical lens. We report on design and fabrication of the mold that through simulation analysis of molding. Finally, through molding test, the fabrication of mold's surface and parameters of molding has been optimized, ensuring the indicators of chalcogenide glass aspherical lens meet the requirements.

  19. Plasma lens experiments at the Final Focus Test Beam

    Energy Technology Data Exchange (ETDEWEB)

    Barletta, B. [California Univ., Los Angeles, CA (United States)]|[Lawrence Berkeley Lab., CA (United States); Chattopadhyay, S. [Lawrence Berkeley Lab., CA (United States); Chen, P. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)] [and others

    1993-04-01

    We intend to carry out a series of plasma lens experiments at the Final Focus Test Beam facility at SLAC. These experiments will be the first to study the focusing of particle beams by plasma focusing devices in the parameter regime of interest for high energy colliders, and is expected to lead to plasma lens designs capable of unprecedented spot sizes. Plasma focusing of positron beams will be attempted for the first time. We will study the effects of lens aberrations due to various lens imperfections. Several approaches will be applied to create the plasma required including laser ionization and beam ionization of a working gas. At an increased bunch population of 2.5 {times} 10{sup 10}, tunneling ionization of a gas target by an electron beam -- an effect which has never been observed before -- should be significant. The compactness of our device should prove to be of interest for applications at the SLC and the next generation linear colliders.

  20. Regional multiaxial mechanical properties of the porcine anterior lens capsule.

    Science.gov (United States)

    David, G; Pedrigi, R M; Heistand, M R; Humphrey, J D

    2007-02-01

    The lens capsule of the eye plays fundamental biomechanical roles in both normal physiological processes and clinical interventions. There has been modest attention given to the mechanical properties of this important membrane, however, and prior studies have focused on 1-D analyses of the data. We present results that suggest that the porcine anterior lens capsule has a complex, regionally dependent, nonlinear, anisotropic behavior. Specifically, using a subdomain inverse finite element method to analyze data collected via a new biplane video-based test system, we found that the lens capsule is nearly isotropic (in-plane) near the pole but progressively stiffer in the circumferential compared to the meridional direction as one approaches the equator. Because the porcine capsule is a good model of the young human capsule, there is strong motivation to determine if similar regional variations exist in the human lens capsule for knowledge of such complexities may allow us to improve the design of surgical procedures and implants.

  1. Bio-inspired fluidic lens surgical camera for MIS.

    Science.gov (United States)

    Tsai, Frank S; Johnson, Daniel; Cho, Sung Hwan; Qiao, Wen; Arianpour, Ashkan; Lo, Yu-Hwa

    2009-01-01

    We report a new type of surgical camera that will greatly improve minimally invasive surgery (MIS). The key enabling technology for this camera is a unique type of lens-bio-inspired fluidic lens, which is a bio-mimetic lens that can change its curvature, just like the way human crystalline lens can accommodate. Because of its curvature changing capability, it is now possible to design a new regime of optical systems where auto-focusing and optical zoom can be performed without moving the lens positions, as is done in typical cameras. Hence, miniaturized imaging system with high functionality can be achieved with such technology. MIS is a surgical technique where small incisions are made on the abdominal wall as opposed to a large cut in open surgery. This type of surgery ensures faster patient recovery. The key tool for MIS is its surgical camera, or laparoscope. Traditional laparoscope is long and rigid and limits the field of view. To further advance MIS technology, we utilized bio-inspired fluidic lens to design a highly versatile imager that is small, can change its field of view or zoom optically, works in low light conditions, and varies the viewing angles. The surgical camera prototype is small (total track<17 mm), possesses 3X optical zoom, operates with light emitting diode (LED) lighting, among many other unique features.

  2. Lens Systems for Sky Surveys and Space Surveillance

    Science.gov (United States)

    Ackermann, M.; McGraw, J.; Zimmer, P.

    2013-09-01

    Since the early days of astrophotography, lens systems have played a key role in capturing images of the night sky. The first images were attempted with visual-refractors. These were soon followed with color-corrected refractors and finally specially designed photo-refractors. Being telescopes, these instruments were of long-focus and imaged narrow fields of view. Simple photographic lenses were soon put into service to capture wide-field images. These lenses also had the advantage of requiring shorter exposure times than possible using large refractors. Eventually, lenses were specifically designed for astrophotography. With the introduction of the Schmidt-camera and related catadioptric systems, the popularity of astrograph lenses declined, but surprisingly, a few remained in use. Over the last 30 years, as small CCDs have displaced large photographic plates, lens systems have again found favor for their ability to image great swaths of sky in a relatively small and simple package. In this paper, we follow the development of lens-based astrograph systems from their beginnings through the current use of both commercial and custom lens systems for sky surveys and space surveillance. Some of the optical milestones discussed include the early Petzval-type portrait lenses, the Ross astrographic lens and the current generation of optics such as the commercial 200mm camera lens by Canon, and the Russian VT-53e in service with ISON.

  3. Retina projection using curved lens arrays

    Science.gov (United States)

    Yen, Hao-Ren; Su, Guo-Dung J.

    2016-09-01

    In this paper, we propose a multi-channel imaging system which combines the principles of an insect's compound eye and optical cluster eye. The system consists of two curved structure lens arrays with different pitches. Both of them have the same curvature and the radiuses of the lenses in the arrays are optimized to focus rays on the retina. The optical axes of different channels are tilted to each other in order to reduce the optical system volume and transmit a wide field of view. Each channel of an array of multiple optical system transfers only a part of the field of view. Each partial image passes through each channel and stitches together on the retina to reconstruct a complete image. In order to simulate the image stitching, we also build an eye model. The thickness from the panel to the last surface of lens group is less than 25mm. The panel size is designed to be 4 inch which is the scale of eyeglass. The system can provide a large field of view about 150 degrees which is much wider than the commercial products. By using the 3D printer, we can make a model of lens array to achieve our design.

  4. Ultrasound field measurement using a binary lens

    CERN Document Server

    Clement, Gregory T; Kamakura, Tomoo

    2014-01-01

    Field characterization methods using a scattering target in the absence of a point-like receiver have been well described in which scattering is recorded by a relatively large receiver located outside the field of measurement. Unfortunately, such methods are prone to artifacts due to averaging across the receiver surface. To avoid this problem while simultaneously increasing the gain of a received signal, the present study introduces a binary plate lens designed to focus spherically-spreading waves onto a planar region having a nearly-uniform phase proportional to that of the target location. The lens is similar to a zone plate, but modified to produce a bi-convex-like behavior, such that it focuses both planar and spherically spreading waves. A measurement device suitable for characterizing narrowband ultrasound signals in air is designed around this lens by coupling it to a target and planar receiver. A prototype device is constructed and used to characterize the field of a highly-focused 400 kHz air transd...

  5. A polycarbonate ophthalmic-prescription lens series.

    Science.gov (United States)

    Davis, J K

    1978-08-01

    Improvements in polycarbonate material, production techniques, and scratch-resistant coatings, combined with a process-oriented design, have resulted in a precision lens series. Surface quality is comparable to that of untreated glass ophthalmic lenses. The repeatability of the process results in closely controlled axial power and off-axis performance. For most lens prescriptions, the ANSI Z80.1 optical-center specifications for prescription accuracy are maintained through a total field of view of 40 deg for an 8-mm range of center-of-rotation distances. Off-axis astigmatism is controlled for near-point seeing. The lenses are both lighter and thinner than those of crown glass. A scratch-resistant coating reduces the reflections normally associated with high-index (1.586) materials. Impact resistance exceeds that required by ANSI Z80.7 and is many times that required by ANSI Z80.1.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper analyzes experimentally and by numerical simulations an optical frame retimer and synchronizer unit for 10 Gbit/s Ethernet input frames. The unit is envisaged to be applied in the design of an optically transparent router for Optical Time Division Multiplexed (OTDM) links, aggregating...

  7. Wake monochromator in asymmetric and symmetric Bragg and Laue geometry for self-seeding the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni; Serkez, Svitozar; Tolkiehn, Martin

    2013-01-01

    We discuss the use of self-seeding schemes with wake monochromators to produce TW power, fully coherent pulses for applications at the dedicated bio-imaging bealine at the European X-ray FEL, a concept for an upgrade of the facility beyond the baseline previously proposed by the authors. We exploit the asymmetric and symmetric Bragg and Laue reflections (sigma polarization) in diamond crystal. Optimization of the bio-imaging beamline is performed with extensive start-to-end simulations, which also take into account effects such as the spatio-temporal coupling caused by the wake monochromator. The spatial shift is maximal in the range for small Bragg angles. A geometry with Bragg angles close to pi/2 would be a more advantageous option from this viewpoint, albeit with decrease of the spectral tunability. We show that it will be possible to cover the photon energy range from 3 keV to 13 keV by using four different planes of the same crystal with one rotational degree of freedom.

  8. Wake monochromator in asymmetric and symmetric Bragg and Laue geometry for self-seeding the European X-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni; Serkez, Svitozar; Tolkiehn, Martin [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-01-15

    We discuss the use of self-seeding schemes with wake monochromators to produce TW power, fully coherent pulses for applications at the dedicated bio-imaging beamline at the European X-ray FEL, a concept for an upgrade of the facility beyond the baseline previously proposed by the authors. We exploit the asymmetric and symmetric Bragg and Laue reflections (sigma polarization) in diamond crystal. Optimization of the bio-imaging beamline is performed with extensive start-to-end simulations, which also take into account effects such as the spatio-temporal coupling caused by the wake monochromator. The spatial shift is maximal in the range for small Bragg angles. A geometry with Bragg angles close to {pi}/2 would be a more advantageous option from this viewpoint, albeit with decrease of the spectral tunability. We show that it will be possible to cover the photon energy range from 3 keV to 13 keV by using four different planes of the same crystal with one rotational degree of freedom.

  9. High resolution short focal distance Bent Crystal Laue Analyzer for copper K edge x-ray absorption spectroscopy.

    Science.gov (United States)

    Kujala, N G; Karanfil, C; Barrea, R A

    2011-06-01

    We have developed a compact short focal distance Bent Crystal Laue Analyzer (BCLA) for Cu speciation studies of biological systems with specific applications to cancer biology. The system provides high energy resolution and high background rejection. The system is composed of an aluminum block serving as a log spiral bender for a 15 micron thick Silicon 111 crystal and a set of soller slits. The energy resolution of the BCLA-about 14 eV at the Cu Kα line- allows resolution of the Cu Kα(1) and CuKα(2) lines. The system is easily aligned by using a set of motorized XYZ linear stages. Two operation modes are available: incident energy scans (IES) and emission energy scans (EES). IES allows scanning of the incident energy while the BCLA system is maintained at a preselected fixed position--typically CuKα(1) line. EES is used when the incident energy is fixed and the analyzer is scanned to provide the peak profile of the emission lines of Cu.

  10. Use of a miniature diamond-anvil cell in high-pressure single-crystal neutron Laue diffraction

    Directory of Open Access Journals (Sweden)

    Jack Binns

    2016-05-01

    Full Text Available The first high-pressure neutron diffraction study in a miniature diamond-anvil cell of a single crystal of size typical for X-ray diffraction is reported. This is made possible by modern Laue diffraction using a large solid-angle image-plate detector. An unexpected finding is that even reflections whose diffracted beams pass through the cell body are reliably observed, albeit with some attenuation. The cell body does limit the range of usable incident angles, but the crystallographic completeness for a high-symmetry unit cell is only slightly less than for a data collection without the cell. Data collections for two sizes of hexamine single crystals, with and without the pressure cell, and at 300 and 150 K, show that sample size and temperature are the most important factors that influence data quality. Despite the smaller crystal size and dominant parasitic scattering from the diamond-anvil cell, the data collected allow a full anisotropic refinement of hexamine with bond lengths and angles that agree with literature data within experimental error. This technique is shown to be suitable for low-symmetry crystals, and in these cases the transmission of diffracted beams through the cell body results in much higher completeness values than are possible with X-rays. The way is now open for joint X-ray and neutron studies on the same sample under identical conditions.

  11. Handbook of optical design

    CERN Document Server

    Malacara-Hernández, Daniel

    2013-01-01

    Handbook of Optical Design, Third Edition covers the fundamental principles of geometric optics and their application to lens design in one volume. It incorporates classic aspects of lens design along with important modern methods, tools, and instruments, including contemporary astronomical telescopes, Gaussian beams, and computer lens design. Written by respected researchers, the book has been extensively classroom-tested and developed in their lens design courses. This well-illustrated handbook clearly and concisely explains the intricacies of optical system design and evaluation. It also di

  12. Lightweight Inexpensive Ozone Lidar Telescope Using a Plastic Fresnel Lens

    Science.gov (United States)

    DeYoung, Russell J.; Notari, Anthony; Carrion, William; Pliutau, Denis

    2014-01-01

    An inexpensive lightweight ozone lidar telescope was designed, constructed and operated during an ozone lidar field campaign. This report summarizes the design parameters and performance of the plastic Fresnel lens telescope and shows the ozone lidar performance compared to Zemax calculations.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    compression, as well. The overall design is: (1) Pulses are converted from NRZ to RZ; (2) pulses are synchronized, retimed and further compressed at the specially designed time-lens; and (3) with adequate optical delays, frames from different input interfaces are added, with a simple optical coupler...

  14. Bionic optical imaging system with aspheric solid-liquid mixed variable-focus lens

    Science.gov (United States)

    Du, Jia-Wei; Wang, Xuan-Yin; Liang, Dan

    2016-02-01

    A bionic optical imaging system with an aspheric solid-liquid mixed variable-focus lens was designed and fabricated. The entire system mainly consisted of a doublet lens, a solid-liquid mixed variable-focus lens, a connecting part, and a CCD imaging device. To mimic the structure of the crystalline lens, the solid-liquid mixed variable-focus lens consisted of a polydimethylsiloxane (PDMS) lens, a polymethyl methacrylate lens, and the liquid of ethyl silicone oil. By pumping liquid in or out of the cavity using a microinjector, the curvatures of the front and rear surfaces of the PDMS lens were varied, resulting in a change of focal length. The overall structure of the system was presented, as well as a detailed description of the solid-liquid mixed variable-focus lens, material, and fabrication process. Under different injection volumes, the deformation of the PDMS lens was measured and simulated, pictures were captured, and the optical performance was analyzed in simulations and experiments. The focal length of the system ranged from 25.05 to 14.61 mm, and the variation of the diopter was 28.5D, which was larger than that of the human eye.

  15. Connexin hemichannels in the lens

    Directory of Open Access Journals (Sweden)

    Eric C Beyer

    2014-02-01

    Full Text Available The normal function and survival of cells in the avascular lens is facilitated by intercellular communication through an extensive network of gap junctions formed predominantly by three connexins (Cx43, Cx46, and Cx50. In expression systems, these connexins can all induce hemi-channel currents, but other lens proteins (e.g., pannexin1 can also induce similar currents. Hemichannel currents have been detected in isolated lens fiber cells. These hemichannels may make significant contributions to normal lens physiology and pathophysiology. Studies of some connexin mutants linked to congenital cataracts have implicated hemichannels with aberrant voltage-dependent gating or modulation by divalent cations in disease pathogenesis. Hemichannels may also contribute to age- and disease-related cataracts.

  16. Surveying the citizen science landscape: an exploration of the design, delivery and impact of citizen science through the lens of the Open Air Laboratories (OPAL) programme.

    Science.gov (United States)

    Davies, Linda; Fradera, Roger; Riesch, Hauke; Lakeman-Fraser, Poppy

    2016-07-22

    This paper provides a short introduction to the topic of citizen science (CS) identifying the shift from the knowledge deficit model to more inclusive, participatory science. It acknowledges the benefits of new technology and the opportunities it brings for mass participation and data manipulation. It focuses on the increase in interest in CS in recent years and draws on experience gained from the Open Air Laboratories (OPAL) programme launched in England in 2007. The drivers and objectives for OPAL are presented together with background information on the partnership, methods and scales. The approaches used by researchers ranged from direct public participation in mass data collection through field surveys to research with minimal public engagement. The supporting services focused on education, particularly to support participants new to science, a media strategy and data services. Examples from OPAL are used to illustrate the different approaches to the design and delivery of CS that have emerged over recent years and the breadth of opportunities for public participation the current landscape provides. Qualitative and quantitative data from OPAL are used as evidence of the impact of CS. While OPAL was conceived ahead of the more recent formalisation of approaches to the design, delivery and analysis of CS projects and their impact, it nevertheless provides a range of examples against which to assess the various benefits and challenges emerging in this fast developing field.

  17. Gravitational lens surveys with LOFAR

    CERN Document Server

    Wucknitz, O

    2008-01-01

    Deep surveys planned as a Key Science Project of LOFAR provide completely new opportunities for gravitational lens searches. For the first time do large-scale surveys reach the resolution required for a direct selection of lens candidates using morphological criteria. We briefly describe the strategies that we will use to exploit this potential. The long baselines of an international E-LOFAR are essential for this project.

  18. Ascorbate in the ocular lens

    OpenAIRE

    Mody, Vino C. Jr

    2006-01-01

    Purpose: First, we intended to establish a method for sample preparation for measurement of ascorbate in whole rat and guinea pig lenses utilizing ultrafiltration and high performance liquid chromatography with ultraviolet radiation detection. Then, we aimed to investigate whether, in the albino rat, lens ascorbate concentration depends on solid dietary intake. Finally, we investigated if, in the pigmented guinea pig, lens ascorbate concentration may be elevated with drinkin...

  19. Phakic Intraocular lens- a review

    OpenAIRE

    Cruz, Francisco Miguel

    2015-01-01

    Introduction: Intraocular refractive procedures with the implantation of a Phakic Intraocular lens have become a safe efficient and predictable alternative for treating high ametropias when the use of corneal photoablative procedures is not possible. The implantation of Phakic intraocular lens preservs the accomodative function,is a reversable refractive procedure, with minimal induction of higher order aberrations compaed with corneal photoablative procedures. Methods: An analytical review o...

  20. Optical near-field microscopy of light focusing through a photonic crystal flat lens.

    Science.gov (United States)

    Fabre, Nathalie; Lalouat, Loïc; Cluzel, Benoit; Mélique, Xavier; Lippens, Didier; de Fornel, Frédérique; Vanbésien, Olivier

    2008-08-15

    We report here the direct observation by using a scanning near-field microscopy technique of the light focusing through a photonic crystal flat lens designed and fabricated to operate at optical frequencies. The lens is fabricated using a III-V semiconductor slab, and we directly visualize the propagation of the electromagnetic waves by using a scanning near-field optical microscope. We directly evidence spatially, as well as spectrally, the focusing operating regime of the lens. At last, in light of the experimental scanning near-field optical microscope pictures, we discuss the lens ability to focus light at a subwavelength scale.

  1. The Lissajous lens: a three-dimensional absolute optical instrument without spherical symmetry.

    Science.gov (United States)

    Danner, Aaron J; Dao, H L; Tyc, Tomáš

    2015-03-09

    We propose a three dimensional optical instrument with an isotropic gradient index in which all ray trajectories form Lissajous curves. The lens represents the first absolute optical instrument discovered to exist without spherical symmetry (other than trivial cases such as the plane mirror or conformal maps of spherically-symmetric lenses). An important property of this lens is that a three-dimensional region of space can be imaged stigmatically with no aberrations, with a point and its image not necessarily lying on a straight line with the lens center as in all other absolute optical instruments. In addition, rays in the Lissajous lens are not confined to planes. The lens can optionally be designed such that no rays except those along coordinate axes form closed trajectories, and conformal maps of the Lissajous lens form a rich new class of optical instruments.

  2. 基于无缝平凹透镜阵列的LCD背光模组设计%Design of LCD Backlight Module Based on Piano-Concave Lens Array

    Institute of Scientific and Technical Information of China (English)

    谢莉; 孙可; 刘浩; 陈刚

    2011-01-01

    针对大尺寸LCD直下式背光模组的均匀性问题提出了一种无缝平凹透镜阵列,用以代替常用的扩散膜.模拟了106.68 mm(42 in)LED背光源的光学分布,得到了合适的透镜半径、结构以及LED阵列间距,分析了平凹透镜阵列半径和平凹透镜阵列与光源的相对位置对匀光作用的影响.结果表明:半径为1 mm、厚度为2 mm的无缝平凹透镜阵列较好地起到了匀光的效果,接收面的照度均匀性为88.61%.%In order to improve the uniformity of the LCD backlight, a kind of plano-concave lens array was used in straight down type LCD backlight module instead of the diffusion films. For 106. 68 mm (42 in) LCD monitor LED backlight, the illuminance distribution was simulated, and the optimized lens radius,structure, distance of LED array were determined. The effect of different lens radius and lens array position on the uniformity of backlight was also discussed. The results show that the plano-concave lens array can diffuses lights better when the radius of lens is 1 mm and the thickness of lens is 2 mm, the uniformity of light reaches 88.61%.

  3. Manufacturing injection-moleded Fresnel lens parquets for point-focus concentrating photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    Peters, E.M.; Masso, J.D. [AOtec, Southbridge, MA (United States)

    1995-10-01

    This project involved the manufacturing of curved-faceted, injection-molded, four-element Fresnel lens parquets for concentrating photovoltaic arrays. Previous efforts showed that high-efficiency (greater than 82%) Fresnel concentrators could be injection molded. This report encompasses the mold design, molding, and physical testing of a four-lens parquet for a solar photovoltaic concentrator system.

  4. Three-element zoom lens with fixed distance between focal points.

    Science.gov (United States)

    Mikš, Antonin; Novák, Jiří; Novák, Pavel

    2012-06-15

    This work deals with a theoretical analysis of zoom lenses with a fixed distance between focal points. Equations are derived for the primary (paraxial) design of the basic parameters of a three-element zoom lens. It is shown that the number of optical elements for such a lens must be larger than two.

  5. Sensitivity of imaging properties of metal-dielectric layered flat lens to fabrication inaccuracies

    DEFF Research Database (Denmark)

    Kotynski, R.; Baghdasaryan, H.; Stefaniuk, T.;

    2010-01-01

    We characterize the sensitivity of imaging properties of a layered silver-TiO2 flat lens to fabrication inaccuracies. The lens is designed for approximately diffraction-free imaging with subwavelength resolution at distances in the order of a wavelength. Its operation may be attributed to self...

  6. An electrostatic deceleration lens for highly charged ions.

    Science.gov (United States)

    Rajput, J; Roy, A; Kanjilal, D; Ahuja, R; Safvan, C P

    2010-04-01

    The design and implementation of a purely electrostatic deceleration lens used to obtain beams of highly charged ions at very low energies is presented. The design of the lens is such that it can be used with parallel as well as diverging incoming beams and delivers a well focused low energy beam at the target. In addition, tuning of the final energy of the beam over a wide range (1 eV/q to several hundred eV/q, where q is the beam charge state) is possible without any change in hardware configuration. The deceleration lens was tested with Ar(8+), extracted from an electron cyclotron resonance ion source, having an initial energy of 30 keV/q and final energies as low as 70 eV/q have been achieved.

  7. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  8. Broadband Wide Angle Lens Implemented with Dielectric Metamaterials

    Directory of Open Access Journals (Sweden)

    Anthony Starr

    2011-08-01

    Full Text Available The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar detector and emitter arrays. Using the recently developed technique of transformation optics, it is possible to transform the curved focal surface to a flat plane while maintaining the perfect focusing behavior of the Luneburg over a wide field of view. Here we apply these techniques to a lesser-known refractive Luneburg lens and implement the design with a metamaterial composed of a semi-crystalline distribution of holes drilled in a dielectric. In addition, we investigate the aberrations introduced by various approximations made in the implementation of the lens. The resulting design approach has improved mechanical strength with small aberrations and is ideally suited to implementation at infrared and visible wavelengths.

  9. Broadband Wide Angle Lens Implemented with Dielectric Metamaterials

    Science.gov (United States)

    Hunt, John; Kundtz, Nathan; Landy, Nathan; Nguyen, Vinh; Perram, Tim; Starr, Anthony; Smith, David R.

    2011-01-01

    The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar detector and emitter arrays. Using the recently developed technique of transformation optics, it is possible to transform the curved focal surface to a flat plane while maintaining the perfect focusing behavior of the Luneburg over a wide field of view. Here we apply these techniques to a lesser-known refractive Luneburg lens and implement the design with a metamaterial composed of a semi-crystalline distribution of holes drilled in a dielectric. In addition, we investigate the aberrations introduced by various approximations made in the implementation of the lens. The resulting design approach has improved mechanical strength with small aberrations and is ideally suited to implementation at infrared and visible wavelengths. PMID:22164056

  10. Intraocular camera for retinal prostheses: Refractive and diffractive lens systems

    Science.gov (United States)

    Hauer, Michelle Christine

    The focus of this thesis is on the design and analysis of refractive, diffractive, and hybrid refractive/diffractive lens systems for a miniaturized camera that can be surgically implanted in the crystalline lens sac and is designed to work in conjunction with current and future generation retinal prostheses. The development of such an intraocular camera (IOC) would eliminate the need for an external head-mounted or eyeglass-mounted camera. Placing the camera inside the eye would allow subjects to use their natural eye movements for foveation (attention) instead of more cumbersome head tracking, would notably aid in personal navigation and mobility, and would also be significantly more psychologically appealing from the standpoint of personal appearances. The capability for accommodation with no moving parts or feedback control is incorporated by employing camera designs that exhibit nearly infinite depth of field. Such an ultracompact optical imaging system requires a unique combination of refractive and diffractive optical elements and relaxed system constraints derived from human psychophysics. This configuration necessitates an extremely compact, short focal-length lens system with an f-number close to unity. Initially, these constraints appear highly aggressive from an optical design perspective. However, after careful analysis of the unique imaging requirements of a camera intended to work in conjunction with the relatively low pixellation levels of a retinal microstimulator array, it becomes clear that such a design is not only feasible, but could possibly be implemented with a single lens system.

  11. Electro-optically actuated liquid-lens zoom

    Science.gov (United States)

    Pütsch, O.; Loosen, P.

    2012-06-01

    Progressive miniaturization and mass market orientation denote a challenge to the design of dynamic optical systems such as zoom-lenses. Two working principles can be identified: mechanical actuation and application of active optical components. Mechanical actuation changes the focal length of a zoom-lens system by varying the axial positions of optical elements. These systems are limited in speed and often require complex coupled movements. However, well established optical design approaches can be applied. In contrast, active optical components change their optical properties by varying their physical structure by means of applying external electric signals. An example are liquidlenses which vary their curvatures to change the refractive power. Zoom-lenses benefit from active optical components in two ways: first, no moveable structures are required and second, fast response characteristics can be realized. The precommercial development of zoom-lenses demands simplified and cost-effective system designs. However the number of efficient optical designs for electro-optically actuated zoom-lenses is limited. In this paper, the systematic development of an electro-optically actuated zoom-lens will be discussed. The application of aberration polynomials enables a better comprehension of the primary monochromatic aberrations at the lens elements during a change in magnification. This enables an enhanced synthesis of the system behavior and leads to a simplified zoom-lens design with no moving elements. The change of focal length is achieved only by varying curvatures of targeted integrated electro-optically actuated lenses.

  12. Effects of contact lens wearing on keratoconus: a confocal microscopy observation

    Science.gov (United States)

    Ghosh, Somnath; Mutalib, Haliza A; Sharanjeet-Kaur; Ghoshal, Rituparna; Retnasabapathy, Shamala

    2017-01-01

    AIM To evaluate the corneal cell morphology of new keratoconus patients wearing two different types of rigid gas-permeable (RGP) contact lenses for 1y. METHODS Thirty nine eyes of 39 new keratoconus patients were selected and randomly fitted with two types of RGP contact lenses. Group 1 had 21 eyes with regular rigid gas-permeable (RRGP) contact lens and rest 18 eyes were in group 2 with specially designed rigid gas-permeable (SRGP) contact lens. Corneal cell morphology was evaluated using a slit scanning confocal microscope at no-lens wear and after 1y of contact lens wearing. RESULTS After 1y of contact lens wearing in group 1, the mean anterior and posterior stromal keratocyte density were significantly less (P=0.006 and P=0.001, respectively) compared to no-lens wear. The mean cell area of anterior and posterior stromal keratocyte were also significantly different (P=0.005 and P=0.001) from no-lens wear. The anterior and posterior stromal haze increased by 18.74% and 23.81%, respectively after 1y of contact lens wearing. Whereas in group 2, statistically significant changes were observed only in cell density & area of anterior stroma (P=0.001 and P=0.001, respectively) after 1y. While, level of anterior and posterior stromal haze increased by 16.67% and 11.11% after 1y of contact lens wearing. Polymegathism and pleomorphism also increased after 1y of contact lens wearing in both the contact lens groups. CONCLUSION Confocal microscopy observation shows the significant alterations in corneal cell morphology of keratoconic corneas wearing contact lenses especially in group 1. The type of contact lens must be carefully selected to minimize changes in corneal cell morphology. PMID:28251081

  13. Chitah: Strong-gravitational-lens hunter in imaging surveys

    Energy Technology Data Exchange (ETDEWEB)

    Chan, James H. H.; Suyu, Sherry H.; Chiueh, Tzihong; More, Anupreeta; Marshall, Philip J.; Coupon, Jean; Oguri, Masamune; Price, Paul

    2015-07-07

    Strong gravitationally lensed quasars provide powerful means to study galaxy evolution and cosmology. Current and upcoming imaging surveys will contain thousands of new lensed quasars, augmenting the existing sample by at least two orders of magnitude. To find such lens systems, we built a robot, Chitah, that hunts for lensed quasars by modeling the configuration of the multiple quasar images. Specifically, given an image of an object that might be a lensed quasar, Chitah first disentangles the light from the supposed lens galaxy and the light from the multiple quasar images based on color information. A simple rule is designed to categorize the given object as a potential four-image (quad) or two-image (double) lensed quasar system. The configuration of the identified quasar images is subsequently modeled to classify whether the object is a lensed quasar system. We test the performance of Chitah using simulated lens systems based on the Canada–France–Hawaii Telescope Legacy Survey. For bright quads with large image separations (with Einstein radius ${r}_{\\mathrm{ein}}\\gt 1\\buildrel{\\prime\\prime}\\over{.} 1$) simulated using Gaussian point-spread functions, a high true-positive rate (TPR) of $\\sim 90\\%$ and a low false-positive rate of $\\sim 3\\%$ show that this is a promising approach to search for new lens systems. We obtain high TPR for lens systems with ${r}_{\\mathrm{ein}}\\gtrsim 0\\buildrel{\\prime\\prime}\\over{.} 5$, so the performance of Chitah is set by the seeing. We further feed a known gravitational lens system, COSMOS 5921+0638, to Chitah, and demonstrate that Chitah is able to classify this real gravitational lens system successfully. Our newly built Chitah is omnivorous and can hunt in any ground-based imaging surveys.

  14. Wide-aperture aspherical lens for high-resolution terahertz imaging

    Science.gov (United States)

    Chernomyrdin, Nikita V.; Frolov, Maxim E.; Lebedev, Sergey P.; Reshetov, Igor V.; Spektor, Igor E.; Tolstoguzov, Viktor L.; Karasik, Valeriy E.; Khorokhorov, Alexei M.; Koshelev, Kirill I.; Schadko, Aleksander O.; Yurchenko, Stanislav O.; Zaytsev, Kirill I.

    2017-01-01

    In this paper, we introduce wide-aperture aspherical lens for high-resolution terahertz (THz) imaging. The lens has been designed and analyzed by numerical methods of geometrical optics and electrodynamics. It has been made of high-density polyethylene by shaping at computer-controlled lathe and characterized using a continuous-wave THz imaging setup based on a backward-wave oscillator and Golay detector. The concept of image contrast has been implemented to estimate image quality. According to the experimental data, the lens allows resolving two points spaced at 0.95λ distance with a contrast of 15%. To highlight high resolution in the THz images, the wide-aperture lens has been employed for studying printed electronic circuit board containing sub-wavelength-scale elements. The observed results justify the high efficiency of the proposed lens design.

  15. 新型智能材料微小型光学镜头致动器的设计与性能研究%Design and Performance Investigation for Miniature Optical Lens IPMC Actuators

    Institute of Scientific and Technical Information of China (English)

    王延杰; 王永泉; 陈花玲; 朱子才; 罗斌

    2012-01-01

    为了使微小型光学镜头驱动系统满足低能耗、高稳定性以及结构简单的要求,采用新型智能材料IPMC设计了一种微小型的光学镜头致动器,并对其输出力、位移及响应速度等性能进行了研究.根据直线驱动要求确定了瓣形和环形结构;通过化学还原方法制备了IPMC材料,采用激光切割技术分别制作出5种形状的环形和瓣形致动器,并对其性能进行了测试.利用有限元软件,通过等效热模型分析了致动器的基本性能,结果表明:实验测试与理论分析结果一致,误差率在10%以内;瓣形致动器的总体位移性能比环形致动器的好;在3V驱动电压下两者的位移均大于200 μm;当内圆半径为2 mm、瓣数为8时,致动器的最大位移与响应速度均最佳.%To meet the requirements of low consumption, high stability and simplicity for the op-tical lens driving system, ionic polymer-metal composite (IPMC) , a new kind of intelligent mate-rial is adopted to design a miniature optical lens actuator, and its output force, displacement, and response speed are investigated respectively. For the purpose of linear driving, two kinds of actu-ating structures, the petal-shaped and annular structures are determined. Then, IPMC is pre-pared by chemical reduction method and five kinds of petal-shaped and annular actuators are man-ufactured by laser cutting and their performances arc tested. The performances of the actuators with different structure parameters are analyzed using an equivalent thermal model via software FEA. The analytical results coincide well with the experimental ones with error less than 10%, and the displacement performance of petal-shaped actuator is better than that of the annular one. Under actuation voltage of 3 V, both actuators can get displacement over 200 μa The annular actuator with an inner radius of 2 mm and the petal-shaped actuator with 8 petals achieve better performances in both displacement and

  16. Neutronics Conversion Analyses of the Laue-Langevin Institute (ILL) High Flux Reactor (RHF)

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Dionne, B. [Argonne National Lab. (ANL), Argonne, IL (United States); Calzavara, Y. [Inst. Laue-Langevin (ILL), Grenoble (France)

    2014-09-30

    The following report describes the neutronics results obtained with the MCNP model of the RHF U7Mo LEU reference design that has been established in 2010 during the feasibility analysis. This work constitutes a complete and detailed neutronics analysis of that LEU design using models that have been significantly improved since 2010 and the release of the feasibility report. When possible, the credibility of the neutronics model is tested by comparing the HEU model results with experimental data or other codes calculations results. The results obtained with the LEU model are systematically compared to the HEU model. The changes applied to the neutronics model lead to better comparisons with experimental data or improved the calculation efficiency but do not challenge the conclusion of the feasibility analysis. If the U7Mo fuel is commercially available, not cost prohibitive, a back-end solution is established and if it is possible to manufacture the proposed element, neutronics analyses show that the performance of the reactor would not be challenged by the conversion to LEU fuel.

  17. Tinting of intraocular lens implants

    Energy Technology Data Exchange (ETDEWEB)

    Zigman, S.

    1982-06-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users.

  18. International rigid contact lens prescribing.

    Science.gov (United States)

    Efron, Nathan; Morgan, Philip B; Helland, Magne; Itoi, Motozumi; Jones, Deborah; Nichols, Jason J; van der Worp, Eef; Woods, Craig A

    2010-06-01

    Rigid lenses have been fitted less since the introduction of soft lenses nearly 40 years ago. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 facilitate an accurate characterization of the pattern of the decline of rigid lens fitting during the first decade of this century. There is a trend for rigid lenses to be utilized primarily for refitting those patients who are already successful rigid lens wearers-most typically older females being refit with higher Dk materials. Rigid lenses are generally fitted on a full-time basis (four or more days of wear per week) without a planned replacement schedule. Orthokeratology is especially popular in the Netherlands, but is seldom prescribed in the other countries surveyed.

  19. The SNAP Strong Lens Survey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, P.

    2005-01-03

    Basic considerations of lens detection and identification indicate that a wide field survey of the types planned for weak lensing and Type Ia SNe with SNAP are close to optimal for the optical detection of strong lenses. Such a ''piggy-back'' survey might be expected even pessimistically to provide a catalogue of a few thousand new strong lenses, with the numbers dominated by systems of faint blue galaxies lensed by foreground ellipticals. After sketching out our strategy for detecting and measuring these galaxy lenses using the SNAP images, we discuss some of the scientific applications of such a large sample of gravitational lenses: in particular we comment on the partition of information between lens structure, the source population properties and cosmology. Understanding this partitioning is key to assessing strong lens cosmography's value as a cosmological probe.

  20. Planar immersion lens with metasurfaces

    CERN Document Server

    Ho, John S; Tanabe, Yuji; Yeh, Alexander J; Fan, Shanhui; Poon, Ada S Y

    2015-01-01

    The solid immersion lens is a powerful optical tool that allows light entering material from air or vacuum to focus to a spot much smaller than the free-space wavelength. Conventionally, however, they rely on semispherical topographies and are non-planar and bulky, which limits their integration in many applications. Recently, there has been considerable interest in using planar structures, referred to as metasurfaces, to construct flat optical components for manipulating light in unusual ways. Here, we propose and demonstrate the concept of a planar immersion lens based on metasurfaces. The resulting planar device, when placed near an interface between air and dielectric material, can focus electromagnetic radiation incident from air to a spot in material smaller than the free-space wavelength. As an experimental demonstration, we fabricate an ultrathin and flexible microwave lens and further show that it achieves wireless energy transfer in material mimicking biological tissue.

  1. Algebraic Lens Distortion Model Estimation

    Directory of Open Access Journals (Sweden)

    Luis Alvarez

    2010-07-01

    Full Text Available A very important property of the usual pinhole model for camera projection is that 3D lines in the scene are projected to 2D lines. Unfortunately, wide-angle lenses (specially low-cost lenses may introduce a strong barrel distortion, which makes the usual pinhole model fail. Lens distortion models try to correct such distortion. We propose an algebraic approach to the estimation of the lens distortion parameters based on the rectification of lines in the image. Using the proposed method, the lens distortion parameters are obtained by minimizing a 4 total-degree polynomial in several variables. We perform numerical experiments using calibration patterns and real scenes to show the performance of the proposed method.

  2. Holographic Lens for Pilot’s Head-Up Display

    Science.gov (United States)

    1976-02-01

    corners is thought to be a limitation imposed by the present relay lens design rather than a property of the holographic element. The effective f...conclusion is partiidly misleading, in that Figuras 33a and 33b represent only those fans traced along the x and y axes of the pupil; no in-fornia- tion

  3. Holographic Rovers: Augmented Reality and the Microsoft HoloLens

    Science.gov (United States)

    Toler, Laura

    2017-01-01

    Augmented Reality is an emerging field in technology, and encompasses Head Mounted Displays, smartphone apps, and even projected images. HMDs include the Meta 2, Magic Leap, Avegant Light Field, and the Microsoft HoloLens, which is evaluated specifically. The Microsoft HoloLens is designed to be used as an AR personal computer, and is being optimized with that goal in mind. Microsoft allied with the Unity3D game engine to create an SDK for interested application developers that can be used in the Unity environment.

  4. Integrated Lens Antennas for Multi-Pixel Receivers

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam

    2011-01-01

    Future astrophysics and planetary experiments are expected to require large focal plane arrays with thousands of detectors. Feedhorns have excellent performance, but their mass, size, fabrication challenges, and expense become prohibitive for very large focal plane arrays. Most planar antenna designs produce broad beam patterns, and therefore require additional elements for efficient coupling to the telescope optics, such as substrate lenses or micromachined horns. An antenna array with integrated silicon microlenses that can be fabricated photolithographically effectively addresses these issues. This approach eliminates manual assembly of arrays of lenses and reduces assembly errors and tolerances. Moreover, an antenna array without metallic horns will reduce mass of any planetary instrument significantly. The design has a monolithic array of lens-coupled, leaky-wave antennas operating in the millimeter- and submillimeter-wave frequencies. Electromagnetic simulations show that the electromagnetic fields in such lens-coupled antennas are mostly confined in approximately 12 15 . This means that one needs to design a small-angle sector lens that is much easier to fabricate using standard lithographic techniques, instead of a full hyper-hemispherical lens. Moreover, this small-angle sector lens can be easily integrated with the antennas in an array for multi-pixel imager and receiver implementation. The leaky antenna is designed using double-slot irises and fed with TE10 waveguide mode. The lens implementation starts with a silicon substrate. Photoresist with appropriate thickness (optimized for the lens size) is spun on the substrate and then reflowed to get the desired lens structure. An antenna array integrated with individual lenses for higher directivity and excellent beam profile will go a long way in realizing multi-pixel arrays and imagers. This technology will enable a new generation of compact, low-mass, and highly efficient antenna arrays for use in multi

  5. Elastic constants of the human lens capsule.

    Science.gov (United States)

    Fisher, R F

    1969-03-01

    1. A technique is described whereby the elasticity of the human lens capsule has been determined at birth and throughout life. This technique requires three separate determinations: (a) thickness; (b) stress and strain; (c) Poisson's ratio; (a) the capsule was clamped between accurately perforated ground glass plates and its thickness determined by noting the change in depth of focus between Latex spherules adhering to its upper and lower surfaces; (b) the undisturbed capsule was then placed in a specially designed glass distension apparatus and the relationship between volume and pressure recorded when it was distended with isotonic saline. The permeability of the capsule was also measured; (c) in some cases Poisson's ratio was determined by measuring the change of thickness of the capsule and the height to which it rose when distended with isotonic saline at different pressures. An apparatus was designed for this purpose.2. The average thickness of the anterior capsule increases from birth until about the 60th year but thereafter it decreases slightly.3. Poisson's ratio was about 0.47 for both cat and human capsule, and no significant variations with age in human capsule could be detected.4. Corrected volume pressure curves obeyed Hook's law almost to the point of capsule rupture.5. In childhood Young's Modulus of elasticity is about 6 x 10(7) dyn/cm(2) and decreases to 3 x 10(7) dyn/cm(2) at 60 and 1.5 x 10(7) dyn/cm(2) in extreme old age.6. The ultimate tensile stress was 2.3 x 10(7) dyn/cm(2) in young capsules and 0.7 x 10(7) dyn/cm(2) in old ones. The maximum percentage elongation was 29 per cent and independent of age.7. The implications of these findings are discussed in relation to(a) the mechanical properties of the lens capsule;(b) the ageing of the lens capsule and basement membranes; and(c) the decrease in elasticity of the lens capsule as a cause of presbyopia.

  6. Gravitational Lens Modeling with Genetic Algorithms and Particle Swarm Optimizers

    CERN Document Server

    Rogers, Adam

    2011-01-01

    Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear optimization by an advanced genetic algorithm (GA) and particle swarm optimizer (PSO). These global optimization routines are designed to explore the parameter space thoroughly, mapping model degeneracies in detail. We develop a novel method that determines the L-curve for each solution automa...

  7. An X-ray Raman spectrometer for EXAFS studies on minerals: bent Laue spectrometer with 20 keV X-rays.

    Science.gov (United States)

    Hiraoka, N; Fukui, H; Tanida, H; Toyokawa, H; Cai, Y Q; Tsuei, K D

    2013-03-01

    An X-ray Raman spectrometer for studies of local structures in minerals is discussed. Contrary to widely adopted back-scattering spectrometers using ≤10 keV X-rays, a spectrometer utilizing ~20 keV X-rays and a bent Laue analyzer is proposed. The 20 keV photons penetrate mineral samples much more deeply than 10 keV photons, so that high intensity is obtained owing to an enhancement of the scattering volume. Furthermore, a bent Laue analyzer provides a wide band-pass and a high reflectivity, leading to a much enhanced integrated intensity. A prototype spectrometer has been constructed and performance tests carried out. The oxygen K-edge in SiO(2) glass and crystal (α-quartz) has been measured with energy resolutions of 4 eV (EXAFS mode) and 1.3 eV (XANES mode). Unlike methods previously adopted, it is proposed to determine the pre-edge curve based on a theoretical Compton profile and a Monte Carlo multiple-scattering simulation before extracting EXAFS features. It is shown that the obtained EXAFS features are reproduced fairly well by a cluster model with a minimal set of fitting parameters. The spectrometer and the data processing proposed here are readily applicable to high-pressure studies.

  8. SimpLens: Interactive gravitational lensing simulator

    Science.gov (United States)

    Saha, Prasenjit; Williams, Liliya L. R.

    2016-06-01

    SimpLens illustrates some of the theoretical ideas important in gravitational lensing in an interactive way. After setting parameters for elliptical mass distribution and external mass, SimpLens displays the mass profile and source position, the lens potential and image locations, and indicate the image magnifications and contours of virtual light-travel time. A lens profile can be made shallower or steeper with little change in the image positions and with only total magnification affected.

  9. Characterization of an aerodynamic lens for transmitting particles > 1 micrometer in diameter into the Aerodyne aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    L. R. Williams

    2013-06-01

    Full Text Available We have designed and characterized a new inlet and aerodynamic lens for the Aerodyne aerosol mass spectrometer (AMS that transmits particles between 80 nm and more than 3 μm in diameter. The design of the inlet and lens was optimized with computational fluid dynamics (CFD modeling of particle trajectories. Major changes include a redesigned critical orifice holder and valve assembly, addition of a relaxation chamber behind the critical orifice, and a higher lens operating pressure. The transmission efficiency of the new inlet and lens was characterized experimentally with size-selected particles. Experimental measurements are in good agreement with the calculated transmission efficiency.

  10. Can manipulation of orthokeratology lens parameters modify peripheral refraction?

    Science.gov (United States)

    Kang, Pauline; Gifford, Paul; Swarbrick, Helen

    2013-11-01

    To investigate changes in peripheral refraction, corneal topography, and aberrations induced by changes in orthokeratology (OK) lens parameters in myopes. Subjects were fitted with standard OK lenses that were worn overnight for 2 weeks. Peripheral refraction, corneal topography, and corneal surface aberrations were measured at baseline and after 14 nights of OK lens wear. Subsequent to a 2-week washout period, subjects were refitted with another set of lenses where one eye was randomly assigned to wear an OK lens with a smaller optic zone diameter (OZD) and the other eye with a steeper peripheral tangent. Measurements were taken again at a second baseline and after 14 days of overnight wear of the second OK lens set. Standard OK lenses with a 6-mm OZD and 1/4 peripheral tangent caused significant changes in both peripheral refraction and corneal topography. Significant hyperopic shift occurred in the central visual field (VF) while a myopic shift was found at 35 degrees in the nasal VF. OK induced significant reductions in corneal power at all positions along the horizontal corneal chord except at 2.4 mm nasal where there was no significant change and at 2.8 mm nasal where there was an increase in corneal refractive power. A positive shift in spherical aberration was induced for all investigated lens designs except for the 1/2 tangent design when calculated over a 4-mm pupil. Reducing OZD and steepening the peripheral tangent did not cause significant changes in peripheral refraction or corneal topography profiles across the horizontal meridian. OK lenses caused significant changes in peripheral refraction, corneal topography, and corneal surface aberrations. Modifying OZD and peripheral tangent made no significant difference to the peripheral refraction or corneal topography profile. Attempting to customize refraction and topography changes through manipulation of OK lens parameters appears to be a difficult task.

  11. Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients

    Science.gov (United States)

    Hu, Shufang; Wang, Mingling; Xiao, Tianlin; Zhao, Zhenquan

    2016-01-01

    Aim: To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. Settings and Design: Retrospective, noncomparable consecutive case series study. Materials and Methods: Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. Results: Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or <20/1000. Within a 1.1–4.2-year follow-up period, a significant increase, equal to or better than 20/66, in UCVA was observed in six (55%) cases, and in best-corrected VA (BCVA) was observed in nine (82%) cases. Postoperative BCVA was 20/40 or better in seven cases (64%). After combined surgery, the iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. Conclusions: Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support. PMID:27146932

  12. In vivo human crystalline lens topography.

    Science.gov (United States)

    Ortiz, Sergio; Pérez-Merino, Pablo; Gambra, Enrique; de Castro, Alberto; Marcos, Susana

    2012-10-01

    Custom high-resolution high-speed anterior segment spectral domain optical coherence tomography (OCT) was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo. The system was provided with custom algorithms for denoising and segmentation of the images, as well as for fan (scanning) and optical (refraction) distortion correction, to provide fully quantitative images of the anterior and posterior crystalline lens surfaces. The method was tested on an artificial eye with known surfaces geometry and on a human lens in vitro, and demonstrated on three human lenses in vivo. Not correcting for distortion overestimated the anterior lens radius by 25% and the posterior lens radius by more than 65%. In vivo lens surfaces were fitted by biconicoids and Zernike polynomials after distortion correction. The anterior lens radii of curvature ranged from 10.27 to 14.14 mm, and the posterior lens radii of curvature ranged from 6.12 to 7.54 mm. Surface asphericities ranged from -0.04 to -1.96. The lens surfaces were well fitted by quadrics (with variation smaller than 2%, for 5-mm pupils), with low amounts of high order terms. Surface lens astigmatism was significant, with the anterior lens typically showing horizontal astigmatism ([Formula: see text] ranging from -11 to -1 µm) and the posterior lens showing vertical astigmatism ([Formula: see text] ranging from 6 to 10 µm).

  13. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens. 886.3600 Section 886.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials...

  14. 室内可见光通信系统中菲涅尔透镜接收天线的设计研究∗%Design and study of Fresnel lens for an antenna in indo or visible light communication system

    Institute of Scientific and Technical Information of China (English)

    李湘; 蓝天; 王云; 王龙辉

    2015-01-01

    针对基于白光LED室内可见光无线光通信技术的应用需求,设计了等齿距平面菲涅尔透镜.相比常规透镜光接收天线,菲涅尔透镜具有聚焦能力强、焦距短、透镜厚度薄、重量轻、成本低等优点.利用Trace pro软件对设计进行了模拟仿真,分析了透镜不同设计参数对接收天线光学增益、光学效率及光斑尺寸的影响,讨论了透镜在平行光斜入射时的会聚情况.结果表明,平面点聚焦菲涅尔透镜的光学效率可达92.1%,适用于小视场、高增益接收光学系统前端.%Indoor visible light communication is a novel wireless communication based on white LED technology. For its application needs, equal-pitch flat Fresnel lens is designed. Compared with traditional lens, Fresnel lens has several advantages including strong focus ability, short focal length, thin thickness, light weight, low cost, etc. The optical concentration ratio, the optical efficiency and the spot size of these Fresnel lenses are analyzed respectively with different parameters by means of Trace pro. Furthermore, the concentration performance is discussed at different incident angles. The results indicate that this kind of Fresnel lens could be used as an antenna of high-gain and small field, and the optical efficiency could be obtained to be 92.1%.

  15. Professoren og Ålen

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2016-01-01

    Biolog og havforsker Johannes Schmidt regnes for at være Danmarks mest betydningsfulde havforsker gennem tiderne. Hans mange forskningsbaserede jordomsejlinger bragte ham til eksotiske egne og til opdagelsen af adskillige nye dyrearter. Dog blev særligt ålen og dens gydepladser et hovedfokus...

  16. Professoren og Ålen

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2016-01-01

    Biolog og havforsker Johannes Schmidt regnes for at være Danmarks mest betydningsfulde havforsker gennem tiderne. Hans mange forskningsbaserede jordomsejlinger bragte ham til eksotiske egne og til opdagelsen af adskillige nye dyrearter. Dog blev særligt ålen og dens gydepladser et hovedfokus for ...

  17. Estimation of the hybrid lens parameters through rigid gas permeable lens fitting

    OpenAIRE

    Hasani, Mohammadali; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbas Ali; Dadbin, Nooshin; khabazkhoob, Mehdi

    2016-01-01

    Purpose To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens. Methods Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with the hybrid contact lens. The relationship between the base curvature of the RGP and the vault of the hybrid lens and the correlation between their powers were analyzed. Results We found a linear relationship betw...

  18. Multifocal contact lens myopia control.

    Science.gov (United States)

    Walline, Jeffrey J; Greiner, Katie L; McVey, M Elizabeth; Jones-Jordan, Lisa A

    2013-11-01

    Previous studies on soft multifocal contact lens myopia control published in the peer-reviewed literature reported findings of noncommercial contact lenses worn for 1 year or less. This study sought to determine the progression of myopia and axial elongation of children fitted with commercially available distance center soft multifocal contact lenses for 2 years. Eight- to eleven-year-old children with -1.00 D to -6.00 D spherical component and less than 1.00 D astigmatism were fitted with soft multifocal contact lenses with a +2.00 D add (Proclear Multifocal "D"; CooperVision, Fairport, NY). They were age- and gender-matched to participants from a previous study who were fitted with single-vision contact lenses (1 Day Acuvue; Vistakon, Jacksonville, FL). A-scan ultrasound and cycloplegic autorefraction were performed at baseline, after 1 year, and after 2 years. Multilevel modeling was used to compare the rate of change of myopia and axial length between single-vision and soft multifocal contact lens wearers. Forty participants were fitted with soft multifocal contact lenses, and 13 did not contribute complete data (5 contributed 1 year of data). The adjusted mean ± standard error spherical equivalent progression of myopia at 2 years was -1.03 ± 0.06 D for the single-vision contact lens wearers and -0.51 ± 0.06 for the soft multifocal contact lens wearers (p < 0.0001). The adjusted mean axial elongation was 0.41 ± 0.03 and 0.29 ± 0.03 for the single-vision and soft multifocal contact lens wearers, respectively (p < 0.0016). Soft multifocal contact lens wear resulted in a 50% reduction in the progression of myopia and a 29% reduction in axial elongation during the 2-year treatment period compared to a historical control group. Results from this and other investigations indicate a need for a long-term randomized clinical trial to investigate the potential for soft multifocal contact lens myopia control.

  19. Lens stem cells may reside outside the lens capsule: an hypothesis

    Directory of Open Access Journals (Sweden)

    Meyer Rita A

    2007-06-01

    Full Text Available Abstract In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors. Historically, the lens has been viewed as a closed system, in which cells at the periphery of the lens epithelium differentiate into fiber cells. Theoretical considerations led us to question whether the intracapsular lens is indeed self-contained. Since stem cells generate tumors and the lens does not naturally develop tumors, we reasoned that lens stem cells may not be present within the capsule. We hypothesize that lens stem cells reside outside the lens capsule, in the nearby ciliary body. Our ideas challenge the existing lens biology paradigm. We begin our discussion with lens background information, in order to describe our lens stem cell hypothesis in the context of published data. Then we present the ciliary body as a possible source for lens stem cells, and conclude by comparing the ocular lens with the corneal epithelium.

  20. Design and Fabrication of the Micro Lens Array Based on SU- 8%基于SU-8的微透镜阵列的设计和制作

    Institute of Scientific and Technical Information of China (English)

    刘建林; 张斌珍; 崔敏; 张剑; 季长红

    2012-01-01

    Using SU- 8 as a structural material, the micro lens arrays with the primary optical axis parallel to the substrate were processed by UV light lithography process, especially inclined exposure technology, and the diameter of a single micro lens is about 500 μm. The exposure dosage, pre-baking time, post-baking time and development time for processing the lens were confirmed preliminarily, providing a reference for processing lens with different size. Micro lens arrays based on the processing method can obtain the focusing, reflection, diffraction, phase modulation and other control for the beam to finally realize functions such as photo switch, attenuation, sweep and image formation, providing convenient for other micro optical device integration, such as spectroscope and reflector. Meanwhile, the micro lens arrays can be integrated in the micro flow cytometry to make fluorescence detection of sample flow, which greatly improves the detection accuracy.%以SU-8作为结构材料,采用紫外光刻工艺,尤其以斜曝光工艺为主,加工出主光轴平行于衬底基片的微透镜阵列,单个微透镜的直径大约为500 μm.初步确定出加工此透镜所需要的曝光剂量、前烘时间、后烘时间和显影时间,为加工其他尺寸的透镜提供参考.基于此方法加工的微透镜阵列能够对光束进行聚焦、反射、衍射、相位调制等控制,从而可最终实现光开关、衰减、扫描和成像等功能,为其他微型光学器件,如分光镜和反射镜等的系统集成提供极大的便利.同时,此微透镜阵列也会被集成在微流细胞仪中用来对流式细胞仪中样本流做荧光检测,极大地提高了检测的精度.

  1. Imaging Functions of Quasi-Periodic Nanohole Array as an Ultra-Thin Planar Optical Lens

    Directory of Open Access Journals (Sweden)

    Tsung Sheng Kao

    2015-06-01

    Full Text Available In this paper, the lensing functions and imaging abilities of a quasi-periodic nanohole array in a metal screen have been theoretically investigated and demonstrated. Such an optical binary mask with nanoholes designed in an aperiodic arrangement can function as an ultra-thin planar optical lens, imaging complex structures composed of multiple light sources at tens of wavelengths away from the lens surface. Via resolving two adjacent testing objects at different separations, the effective numerical aperture (N.A. and the effective imaging area of the planar optical lens can be evaluated, mimicking the imaging function of a conventional lens with high N.A. Furthermore, by using the quasi-periodic nanohole array as an ultra-thin planar optical lens, important applications such as X-ray imaging and nano-optical circuits may be found in circumstances where conventional optical lenses cannot readily be applied.

  2. Parameters measurement of rigid gas permeable contact lens based on optical coherence tomography

    Science.gov (United States)

    Zhu, Dexi; Shen, Meixiao; Li, Yiyu

    2012-10-01

    Spectral domain optical coherence tomography (OCT) was developed in order to measure the geometric parameters of rigid gas permeable (RGP) contact lens. With custom designed OCT system, an ultra-high axial resolution of 3.3 μm in lens was achieved. The OCT image was corrected to eliminate the optical distortion and actual surfaces of lens were shown in contour map. Central thickness, lens diameter, base curve and front surface curvature at optical zone were calculated from the contour map. The results match well with the real values measured by conventional instruments. Our research indicates that OCT can be used to test the RGP lens in a simple and exact way.

  3. Active compensation of wavefront aberrations by controllable heating of lens with electric film heater matrix.

    Science.gov (United States)

    Chen, Hua; Hou, Lv; Zhou, Xinglin

    2016-08-20

    We present a new apparatus for active compensation of wavefront aberrations by controllable heating of a lens using a film heater matrix. The annular electric film heater matrix, comprising 24 individual heaters, is attached to the periphery of a lens. Utilizing the linear superposition, and wavefront change proportional to the heating energy properties induced by heating, a controllable wavefront can be defined by solving a linear function. The two properties of wavefront change of a lens have been confirmed through a specially designed experiment. The feasibility of the compensation method is validated by compensating the wavefront of a plate lens. The results show that the wavefront of the lens changes from 12.52 to 2.95 nm rms after compensation. With a more precise electric controlling board, better results could be achieved.

  4. Paraxial analysis of four-component zoom lens with fixed distance between focal points.

    Science.gov (United States)

    Miks, Antonin; Novak, Jiri

    2012-07-20

    Zoom lenses with a fixed distance between focal points are analyzed. Formulas are derived for the primary design of basic parameters of a four-component zoom lens. It is also demonstrated that a three-component zoom lens can be analyzed using derived formulas. Zoom lenses with such a design can be used in a 4-f system with variable magnification or as a part of a double side telecentric lenses with variable magnification.

  5. Tubular astigmatism-tunable fluidic lens.

    Science.gov (United States)

    Kopp, Daniel; Zappe, Hans

    2016-06-15

    We demonstrate a new means to fabricate three-dimensional liquid lenses which may be tuned in focal length and astigmatism. Using actuation by electrowetting-on-dielectrics, astigmatism in arbitrary directions may be tuned independently, with almost no cross talk between orthogonal orientations. The lens is based on electrodes structured on planar polyimide foils and subsequently rolled, enabling high-resolution patterning of complex electrodes along the azimuthal and radial directions of the lens. Based on a design established through fluidic and optical simulations, the astigmatism tuning is experimentally verified by a change of the corresponding Zernike coefficients measured using a Shack-Hartmann wavefront sensor. It was seen that the back focal length can be tuned by 5 mm and 0° and 45° astigmatism by 3 μm through application of voltages in the range of 50  Vrms. It was observed that the cross talk with other aberrations is very low, suggesting a novel means for astigmatism control in imaging systems.

  6. Scleral lens for keratoconus: technology update

    Directory of Open Access Journals (Sweden)

    Rathi VM

    2015-10-01

    Full Text Available Varsha M Rathi,1 Preeji S Mandathara,2 Mukesh Taneja,1 Srikanth Dumpati,1 Virender S Sangwan1 1L V Prasad Eye Institute, Hyderabad, India; 2School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia Abstract: Scleral lenses are large diameter lenses which rest over the sclera, unlike the conventional contact lenses which rest on the cornea. These lenses are fitted to not touch the cornea and there is a space created between the cornea and the lens. These lenses are inserted in the eyes after filling with sterile isotonic fluid. Generally, scleral contact lenses are used for high irregular astigmatism as seen in various corneal ectatic diseases such as keratoconus, pellucid marginal degeneration, or/and as liquid bandage in ocular surface disorders. In this article, we review the new developments, that have taken place over the years, in the field of scleral contact lenses as regard to new designs, materials, manufacturing technologies, and fitting strategies particularly for keratoconus. Keywords: keratoconus, scleral lens, technology update, PROSE

  7. Conjunctival impression cytology in contact lens wearers.

    Directory of Open Access Journals (Sweden)

    Simon Priya

    2002-01-01

    Full Text Available PURPOSE: To evaluate the cytological changes in conjunctiva following regular contact lens wear and to determine the correlation, if any, between severity of cytological alteration and symptoms related to contact lens wear. METHODS: One hundred eyes (50 normal asymptomatic subjects who served as a control group were studied by conjunctival impression cytology (CIC. These subjects were fitted with rigid gas permeable (RGP or soft contact lenses and were followed up at the end of 3 and 6 months. At each follow-up visit the CIC was repeated. A filter paper with the impression specimen was stained with periodic acid schiff (PAS and haematoxylin stain to study goblet cell loss. Papanicolaou stain was done to study squamous metaplasia. The cytological changes were graded using the system described by Natadisastra et al. RESULTS: Severity of cytological changes increased with the duration of contact lens wear (P = 0.00001. At the end of 6 months, 60% of symptomatic eyes wearing soft contact lens and RGP lens showed abnormal CIC changes. None of the asymptomatic RGP contact lens wearing eyes showed abnormal CIC changes whereas 33.4% of the asymptomatic soft contact lens wearing eyes showed abnormal CIC changes (P = 0.033. Epithelial changes occurred within 3-6 months of contact lens fitting. CONCLUSION: Severity of cytological changes increased with duration of lens wear (P = 0.00001. Prevalence and severity of cytological alteration is more in symptomatic contact lens wearers. Soft contact lens wearers although asymptomatic showed severe CIC changes.

  8. Implementation of a capsular bag model to enable sufficient lens stabilization within a mechanical eye model

    Science.gov (United States)

    Bayer, Natascha; Rank, Elisabet; Traxler, Lukas; Beckert, Erik; Drauschke, Andreas

    2015-03-01

    Cataract still remains the leading cause of blindness affecting 20 million people worldwide. To restore the patients vision the natural lens is removed and replaced by an intraocular lens (IOL). In modern cataract surgery the posterior capsular bag is maintained to prevent inflammation and to enable stabilization of the implant. Refractive changes following cataract surgery are attributable to lens misalignments occurring due to postoperative shifts and tilts of the artificial lens. Mechanical eye models allow a preoperative investigation of the impact of such misalignments and are crucial to improve the quality of the patients' sense of sight. Furthermore, the success of sophisticated IOLs that correct high order aberrations is depending on a critical evaluation of the lens position. A new type of an IOL holder is designed and implemented into a preexisting mechanical eye model. A physiological representation of the capsular bag is realized with an integrated film element to guarantee lens stabilization and centering. The positioning sensitivity of the IOL is evaluated by performing shifts and tilts in reference to the optical axis. The modulation transfer function is used to measure the optical quality at each position. Lens stability tests within the holder itself are performed by determining the modulation transfer function before and after measurement sequence. Mechanical stability and reproducible measurement results are guaranteed with the novel capsular bag model that allows a precise interpretation of postoperative lens misalignments. The integrated film element offers additional stabilization during measurement routine without damaging the haptics or deteriorating the optical performance.

  9. Soft wearable contact lens sensor for continuous intraocular pressure monitoring.

    Science.gov (United States)

    Chen, Guo-Zhen; Chan, Ion-Seng; Leung, Leo K K; Lam, David C C

    2014-09-01

    Intraocular pressure (IOP) is a primary indicator of glaucoma, but measurements from a single visit to the clinic miss the peak IOP that may occur at night during sleep. A soft chipless contact lens sensor that allows the IOP to be monitored throughout the day and at night is developed in this study. A resonance circuit composed of a thin film capacitor coupled with a sensing coil that can sense corneal curvature deformation is designed, fabricated and embedded into a soft contact lens. The resonance frequency of the sensor is designed to vary with the lens curvature as it changes with the IOP. The frequency responses and the ability of the sensor to track IOP cycles were tested using a silicone rubber model eye. The results showed that the sensor has excellent linearity with a frequency response of ∼8 kHz/mmHg, and the sensor can accurately track fluctuating IOP. These results showed that the chipless contact lens sensor can potentially be used to monitor IOP to improve diagnosis accuracy and treatment of glaucoma.

  10. Study on Titanium Nitride Film Modified for Intraocular Lens

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective:To study the characteristics of the intraocular lens using ion beam sputtering depositing titanium nitride thin film on the intraocular lens(IOLs).Methods:To deposite titanium nitride thin film on the top of intraocular lens by ion beam sputtering depositing.We analyzed the surface morphology of intraocular lens through SEM and AFM.We detected intraocular lens resolution through the measurement of intraocular lens.Biocompatibility of intraocular lens is preliminary evaluated in this test.Results:T...

  11. Research on the relation between the contact angle and the interface curvature radius of electrowetting liquid zoom lens

    Science.gov (United States)

    Zhao, Cunhua; Liang, Huiqin; Cui, Dongqing; Hong, Xinhua; Wei, Daling; Gao, Changliu

    2011-08-01

    In the ultralight or ultrathin applied domain of zoom lens, the traditional glass / plastic lens is limited for manufacture technology or cost. Therefore, a liquid lens was put forward to solve the problems. The liquid zoom lens has the merits of lower cost, smaller volume, quicker response, lower energy consumption, continuous zoom and higher accuracy. In liquid zoom lens the precise focal length is obtained by the contact angle changing to affect the curvature radius of interface. In our works, the relations of the exerted voltage, the contact angle, the curvature radius and the focal length were researched and accurately calculated. The calculation of the focal length provides an important theoretical basis for instructing the design of liquid zoom lens.

  12. Lens Coupled Quantum Cascade Laser

    Science.gov (United States)

    Hu, Qing (Inventor); Lee, Alan Wei Min (Inventor)

    2013-01-01

    Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.

  13. Fresnel Lens with Embedded Vortices

    Directory of Open Access Journals (Sweden)

    Sunil Vyas

    2012-01-01

    Full Text Available Vortices of different charges are embedded in a wavefront that has quadratic phase variation, and the intensity distribution near the focal plane is studied. This method may be useful in realizing complicated beam profiles. We have experimentally demonstrated the generation of vortex arrays having integer as well as fractional topological charges that produce different intensity profiles at the focal plane. The phase variation realized on a spatial light modulator (SLM acts as a Fresnel lens with embedded vortices.

  14. Fast-response liquid-crystal lens for 3D displays

    Science.gov (United States)

    Liu, Yifan; Ren, Hongwen; Xu, Su; Li, Yan; Wu, Shin-Tson

    2014-02-01

    Three-dimensional (3D) display has become an increasingly important technology trend for information display applications. Dozens of different 3D display solutions have been proposed. The autostereoscopic 3D display based on lenticular microlens array is a promising approach, and fast-switching microlens array enables this system to display both 3D and conventional 2D images. Here we report two different fast-response microlens array designs. The first one is a blue phase liquid crystal lens driven by the Pedot: PSS resistive film electrodes. This BPLC lens exhibits several attractive features, such as polarization insensitivity, fast response time, simple driving scheme, and relatively low driving voltage, as compared to other BPLC lens designs. The second lens design has a double-layered structure. The first layer is a polarization dependent polymer microlens array, and the second layer is a thin twisted-nematic (TN) liquid crystal cell. When the TN cell is switched on/off, the traversing light through the polymeric lens array is either focused or defocused, so that 2D/3D images are displayed correspondingly. This lens design has low driving voltage, fast response time, and simple driving scheme. Simulation and experiment demonstrate that the performance of both switchable lenses meet the requirement of 3D display system design.

  15. 便携式脉冲调制型医用半导体激光器的驱动电源及光学透镜系统的设计%The design of pulse modulation driving circuit and optical lens system for portable medical semiconductor laser

    Institute of Scientific and Technical Information of China (English)

    闫振宇; 黄时俊; 龚琬玲; 陈仲本

    2012-01-01

    针对脉冲激光器穴位照射治疗的特点,对半导体激光二极管(LD)的驱动电路及光学镜头系统的设计进行了研究。本文设计了一款新型的锂电池供电便携式脉冲医用激光器,介绍了采用脉冲调制恒流驱动的原理以及采用透镜组和电路调整的方法改变激光照射功率密度的光学镜头的设计方法。该款脉冲激光器适用于激光体外穴位照射,对激光临床应用有一定的意义。%In the view of the laser therapy of acupuncture with pulsed laser, we study a semiconductor laser diode driving circuit and a new design of the optical lens system. This paper devises a new type of lithium battery powered medical pulsed laser with the advantages of portable. We describe the basic principle of the pulse signal modulation circuit for LD, and illuminate the design method of the optical lens system which adjusts the lens system and circuit parameter to change the laser power density. This type of device is applicable to the therapy that low intensive laser irradiates directly on the acupuncture point, and has certain significance to the application of laser in clinical medicine.

  16. Contact lens wear is intrinsically inflammatory.

    Science.gov (United States)

    Efron, Nathan

    2017-01-01

    Eye-care practitioners typically associate ocular inflammation during contact lens wear with serious complications such as microbial keratitis; however, more subtle mechanisms may be at play. This paper tests the notion that contact lens wear is intrinsically inflammatory by exploring whether uncomplicated contact lens wear meets the classical, clinical definition of inflammation - rubor (redness), calor (heat), tumor (swelling), dolor (pain) and functio laesa (loss of function) - as well as the contemporary, sub-clinical definition of inflammation (cellular and biochemical reactions). It is demonstrated that all of these clinical and sub-clinical criteria are met with hydrogel lens wear and most are met with silicone hydrogel lens wear, indicating that uncomplicated contact lens wear is intrinsically inflammatory. Consideration of both traditional and contemporary thinking about the role of inflammation in the human body leads to the perhaps surprising conclusion that the chronic, low grade, sub-clinical inflammatory status of the anterior eye during contact lens wear, which may be termed 'para-inflammation', is a positive, protective phenomenon, whereby up-regulation of the immune system, in a non-damaging way, maintains the eye in a state of 'heightened alert', ready to ward off any extrinsic noxious challenge. Characterisation of this inflammatory status may lead to the development of lens engineering or pharmacological strategies to modulate contact lens-induced inflammation, so as to render lens wear more safe and comfortable. © 2016 Optometry Australia.

  17. Photochromic lens mirror-coated with Cr

    Science.gov (United States)

    Shin, Sungho; Lee, Myeongkyu

    2007-11-01

    We have designed and fabricated mirror-coated photochromic lenses for use in sunglasses. These lenses consisted of a Cr thin film sandwiched between two SiO2 layers on the front surface and an anti-reflection (AR) coating on the backside. The SiO2 films above and below the Cr layer were introduced as the protection and buffer layers, respectively. The AR coating was to suppress back-reflection from the lens surface. Deposition of all coating layers were carried out by an e-beam evaporator under Ar atmosphere at P = 10-5 Torr and T = 70 °C. As expected, the overall transmittance decreased with increasing Cr thickness. For a Cr layer of 5 nm thickness, it changed from about 45% in the bleached state down to 25% after exposure to sunlight. This is consistent with the transmission range typically required for sunglasses.

  18. Real-time tracking of CO migration and binding in the α and β subunits of human hemoglobin via 150-ps time-resolved Laue crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Schotte, Friedrich; Cho, Hyun Sun [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520 (United States); Soman, Jayashree [Department of Biochemistry and Cell Biology, and W.M. Keck Center for Computational Biology, Rice University, Houston, TX 77251-1892 (United States); Wulff, Michael [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France); Olson, John S. [Department of Biochemistry and Cell Biology, and W.M. Keck Center for Computational Biology, Rice University, Houston, TX 77251-1892 (United States); Anfinrud, Philip A., E-mail: anfinrud@nih.gov [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520 (United States)

    2013-08-30

    Highlights: ► 150-ps Time-resolved Laue crystallography has unveiled ligand dynamics in hemoglobin. ► Significant kinetic differences are observed in the α and β subunits of hemoglobin. ► The B-site lifetime is ∼1.6 ns in β, and ∼18 ns in α. ► The B-site location in β is ∼0.25 Å closer to the binding site than in α. ► The correlation between CO position and rebinding rate suggests distal control. - Abstract: We have developed the method of picosecond Laue crystallography and used this capability to probe ligand dynamics in tetrameric R-state hemoglobin (Hb). Time-resolved, 2 Å-resolution electron density maps of photolyzed HbCO reveal the time-dependent population of CO in the binding (A) and primary docking (B) sites of both α and β subunits from 100 ps to 10 μs. The proximity of the B site in the β subunit is about 0.25 Å closer to its A binding site, and its k{sub BA} rebinding rate (∼300 μs{sup −1}) is six times faster, suggesting distal control of the rebinding dynamics. Geminate rebinding in the β subunit exhibits both prompt and delayed geminate phases. We developed a microscopic model to quantitatively explain the observed kinetics, with three states for the α subunit and four states for the β subunit. This model provides a consistent framework for interpreting rebinding kinetics reported in prior studies of both HbCO and HbO{sub 2}.

  19. Design and fabrication of cascaded X-ray planar parab olic comp ound refractive lens%级联式平面抛物面型X射线组合折射透镜的设计与制作

    Institute of Scientific and Technical Information of China (English)

    付明磊; 乐孜纯; 周寒青; 张明; 全必胜; 王华; 毛成文; 王昌辉; 沈小燕

    2014-01-01

    Due to its attractive features such as compact size, simple to align and wide working range of photon energy, the X-ray compound refractive lens (CRL) has gradually become one of the standard accessories to focus the X-ray beams from the synchrotron radiation light source. In this paper, a cascaded planar parabolic CRL is designed and fabricated. The novel CRL is composed of type I and type II refractive elements in order to achieve a small spot size while maintaining the transmission. In type I refractive element, the parabolic geometry aperture (R0) is large, while, in type II refractive element, the radius of curvature (R) at the parabolic vertex is small. So N1 numbers of type I and N2 numbers of type II refractive elements are cascaded to form a single-chip CRL. A cascaded X-ray planar parabolic CRL is constructed using PMMA material by means of LIGA techniques. The main structural parameters of type I refractive elements are:N1 =15, R1 =200 µm, 2R01 =564 µm. The main structural parameters of type II refractive elements are: N2 =20, R2 = 50 µm, 2R02 = 140 µm. The cascaded planar parabolic CRL is tested on the beam line whose original incident X-ray spot is 200 µm × 100 µm at Shanghai synchrotron radiation facility. The measured lateral focusing spot size is 24.9 µm@8 keV, the transmission rate is 2.19%and the focal length is 1.052 m.%X射线组合折射透镜(CRL)已逐步成为同步辐射光源下X射线聚焦光学器件的标准配件之一,它具有结构紧凑、易调节校准、适用光子能量范围大等优点.本文设计了一种级联式平面抛物面型CRL,它将N1个具有较大抛物面几何孔径(R0)的折射单元I与N2个具有较小抛物面顶点曲率半径(R)的折射单元II级联,以解决常规CRL设计过程中焦斑尺寸与透过率的矛盾.采用PMMA材料,利用LIGA技术制作了一组级联式平面抛物面型CRL,其中折射单元I的主要结构参数为N1=15, R1=200µm,2R01=564µm;折射单元II

  20. Opto-mechatronics issues in solid immersion lens based near-field recording

    Science.gov (United States)

    Park, No-Cheol; Yoon, Yong-Joong; Lee, Yong-Hyun; Kim, Joong-Gon; Kim, Wan-Chin; Choi, Hyun; Lim, Seungho; Yang, Tae-Man; Choi, Moon-Ho; Yang, Hyunseok; Rhim, Yoon-Chul; Park, Young-Pil

    2007-06-01

    We analyzed the effects of an external shock on a collision problem in a solid immersion lens (SIL) based near-field recording (NFR) through a shock response analysis and proposed a possible solution to this problem with adopting a protector and safety mode. With this proposed method the collision between SIL and media can be avoided. We showed possible solution for contamination problem in SIL based NFR through a numerical air flow analysis. We also introduced possible solid immersion lens designs to increase the fabrication and assembly tolerances of an optical head with replicated lens. Potentially, these research results could advance NFR technology for commercial product.

  1. Analysis of Rotman Lens Antenna for Different Substrates for Circular Contour

    Directory of Open Access Journals (Sweden)

    Shruti Vashist

    2014-07-01

    Full Text Available This paper presents a trifocal Rotman lens design approach. The effect due to change of substrate on the circular contour is observed. The shape of the beam contour is taken as circular. Different substrates can be used for the fabrication of the lens. Three different materials have been used to fabricate the lens antenna .A three beam prototype feeding five element antenna array working in ISM band has been simulated using RLD1.7.Effects on the performance of the antenna is observed.

  2. Generation of terahertz hollow beams by a photonic quasi-crystal flat lens

    Science.gov (United States)

    Feng, Bo; Liu, Exian; Wang, Ziming; Cai, Weicheng; Liu, Hongfei; Wang, Shuo; Liang, Taiyuan; Xiao, Wei; Liu, Jianjun

    2016-06-01

    We have designed a decagonal photonic quasi-crystal (PQC) flat lens, which turns an incident terahertz (THz) plane wave into a hollow beam easily and flexibly. The features of the THz hollow beam can be controlled by varying the parameters of a point defect in the center of the lens, i.e., the PQC flat lens can be used as a flexible tool for THz optical captivity or optical tweezer. The results showing that an airy disk, whose mean beam width is similar to the incident wavelength and power-in-the-bucket (PIB) is more than 96%, can be generated in the far field.

  3. Effects of resonator input power on Kerr lens mode-locked lasers

    Indian Academy of Sciences (India)

    S Kazempour; A Keshavarz; G Honarasa

    2015-07-01

    Using the ABCD matrix method, the common stability region between the sagittal and tangential planes of a four-mirror Kerr lens mode-locked (KLM) laser cavity is obtained for different ranges of input power. In addition, the effect of the input power on the Kerr lens sensitivity is investigated. Optimal input power and position for highest Kerr lens sensitivity in the stability region are presented and self-starting regime has been achieved. Results show that the resonator input power has a great influence on designing the KLM lasers which can be used in fabricating an optimal femtosecond laser.

  4. Smart multifunction diffractive lens experimental validation for future PV cell applications.

    Science.gov (United States)

    Albarazanchi, Abbas; Gérard, Philippe; Ambs, Pierre; Meyrueis, Patrick; Nguyen, Giang-Nam; Heggarty, Kevin

    2016-01-25

    Recently, diffractive optical elements (DOE's) have attracted more attention for applications to third generation PV cells. Some DOE types can provide multiple functions such as spectrum splitting and beam concentration (SSBC) simultaneously. An off-axis diffractive lens has been designed and its ability to achieve the SSBC proved experimentally. This lens can be used to separate the solar spectrum in the Vis-NIR range into two bands with a low concentration factor, and about 70% optical efficiency. It is expected that this kind of lens can be integrated with the lateral multijunction PV cells to build an effective compact solar system.

  5. In-the-bag decentration of an intraocular lens in a patient with a tendency to hypertrophic scarring

    Science.gov (United States)

    Joshi, Rajesh Subhash

    2016-01-01

    Summary We report a case of rapid anterior lens capsular contraction leading to decentration of a hydrophilic acrylic lens with stiff haptics (Rayner design). To our knowledge, this is the first report to investigate early capsular contraction with folding of the haptic over the optic in a patient with a tendency toward hypertrophic scar formation. PMID:27330480

  6. Characteristics of corneal lens chitin in dragonfly compound eyes.

    Science.gov (United States)

    Kaya, Murat; Sargin, Idris; Al-Jaf, Ivan; Erdogan, Sevil; Arslan, Gulsin

    2016-08-01

    Chitin in the compound eyes of arthropods serves as a part of the visual system. The quality of chitin in such highly specialised body parts deserves more detailed examination. Chitin in the corneal (ommatidial) lenses of dragonfly (Sympetrum fonscolombii) compound eyes was isolated by using the classical chemical method. The chitin content of the corneal lenses was determined to be quite high (20.3±0.85%). The FT-IR analysis showed that corneal lens chitin was in the α-form as found in all arthropod species where mechanical strength is required. The surface morphology analysis by scanning electron microscopy revealed that the outer part of corneal lenses consisted of long chitin fibrils with regular arrays of papillary structures while the smoother inner part had concentric lamellated chitin formation with shorter chitin nanofibrils. Chitinase enzymatic digestion studies, elemental analysis results and the degree of acetylation value showed the purity of chitin samples from corneal lens. The maximum degradation temperature value of the corneal lens chitin was observed at 369.2°C. X-ray analysis revealed that corneal lens chitin has high crystallinity index; 96.4%. Identification of chitin found in ommaditia of insect compound eyes can provide insights into insect vision and chitin-based optical material design studies.

  7. Evolution of a pre and post lens tear film with a contact lens

    Science.gov (United States)

    Gerhart, Matthew; Anderson, Daniel

    2012-11-01

    The work is the development, implementation, and analysis of a two-dimensional tear film model including a porous contact lens. The geometry of the problem is: a pre-lens layer that is a thin tear film between the outside air and contact lens, a contact lens that is a rigid but movable porous substrate, and a post-lens layer that is a thin film layer between the contact lens and the cornea. We are looking at short and long term behavior of the evolution of the thin film in the pre-lens layer coupled with the porous layer and the thin squeeze film in the post-lens layer. We model the different behaviors that arise as the Darcy number, evaporation effects, and boundary flux conditions change.

  8. Association between multifocal soft contact lens decentration and visual performance

    Directory of Open Access Journals (Sweden)

    Fedtke C

    2016-06-01

    .191|. Conversely, a moderate but significant correlation with total MFCL decentration was found in the non-presbyopic group for most of the vision variables, indicating a decrease in vision as decentration increased. Conclusion: Certain MFCLs decentered more than others; the same lens designs also ­induced significant amounts of third-order aberrations. An association between MFCL decentration and seven out of nine vision variables was found in the non-presbyopic group, ie, the group where lenses were most decentered, which had larger pupils and lower levels of inherent third-order aberrations. Keywords: vision, multifocal contact lenses, decentration, higher-order aberrations

  9. Lateral shear interferometry with holo shear lens

    Science.gov (United States)

    Joenathan, C.; Mohanty, R. K.; Sirohi, R. S.

    1984-12-01

    A simple method for obtaining lateral shear using holo shear lenses (HSL) has been discussed. This simple device which produces lateral shears in the orthogonal directions has been used for lens testing. The holo shear lens is placed at or near the focus of the lens to be tested. It has also been shown that HSL can be used in speckle shear interferometry as it performs both the functions of shearing and imaging.

  10. Hemispherical projection lens for insect behavior analysis

    Science.gov (United States)

    Aikio, Mika; Takalo, Jouni; Lempeä, Mikko; Vähäsöyrinki, Mikko

    2010-05-01

    Virtual reality projection systems have been used formerly to study if mammals, including humans, are able to act in or understand virtual environments. Insects have been more difficult to study in such circumstances, one of the factors being their large, almost hemispherical field of view. Designing such a projection system that is capable of fulfilling the full field of vision of an insect is a challenging task. Normally, when designing a photographic objective, one of the goals is to minimize field curvature in order to provide sharp image through the whole sensor surface. However, because the image surface in this case is a sphere, flat field is not desirable and the design task becomes an opposite of a typical camera lens. Introducing field curvature becomes mandatory. We have designed and built a system with satisfactory image quality throughout the whole spherical surface with reasonable number of lenses as an add-on for common digital projectors. The manufactured system is able to project an image to a solid angle of 11.95 steradians, and when compared to the whole sphere which is represented with a solid angle of 4π steradians, approximately 5 % of the total sphere area is not illuminated.

  11. A Magnification Lens for Interactive Volume Visualization

    Energy Technology Data Exchange (ETDEWEB)

    LaMar, E; Hamann, B; Joy, K I

    2001-07-19

    Volume visualization of large data sets suffers from the same problem that many other visualization modalities suffer from: either one can visualize the entire data set and lose small details or visualize a small region and lose the context. In this paper, they present a magnification lens technique for volume visualization. While the notion of a magnification-lens is not new, and other techniques attempt to simulate the physical properties of a magnifying lens, their contribution is in developing a magnification lens that is fast, can be implemented using a fairly small software overhead, and has a natural, intuitive appearance. The issue with magnification lens is the border, or transition, region. The lens center and exterior have a constant zoom factor, and are simple to render. It is the border region that blends between the external and interior magnification, and has a non-constant magnification. They use the perspective-correct textures capability, available in most current graphics systems, to produce a lens with a tessellated border region that approximates linear compression with respect to the radius of the magnification lens. They discuss how a cubic border can mitigate the discontinuities resulting from the use of a linear function, without significant performance loss. They discuss various issues concerning development of a three-dimensional magnification lens.

  12. A combined Kirkpatrick-Baez mirror and multilayer lens for sub-10 nm x-ray focusing

    Directory of Open Access Journals (Sweden)

    A. Ruhlandt

    2012-03-01

    Full Text Available We have used a combined optical system of a high gain elliptic Kirkpatrick-Baez mirror system (KB and a multilayer Laue lens (MLL positioned in the focal plane of the KB for hard x-rays nano-focusing. The two-step focusing scheme is based on a high acceptance and high gain elliptical mirror with moderate focal length and a MLL with ultra-short focal length. Importantly, fabrication constraints, i.e. in mirror polishing and bending, as well as MLL deposition can be significantly relaxed, since (a the mirror focus in the range of 200-500 nm is sufficient, and (b the number of layers of the MLL can be correspondingly small. First demonstrations of this setup at the coherence beamline of the PETRA III storage ring yield a highly divergent far-field diffraction pattern, from which the autocorrelation function of the near-field intensity distribution was obtained. The results show that the approach is well suited to reach smallest spot sizes in the sub-10nm range at high flux.

  13. A combined Kirkpatrick-Baez mirror and multilayer lens for sub-10 nm x-ray focusing

    Energy Technology Data Exchange (ETDEWEB)

    Ruhlandt, A.; Krueger, S. P.; Osterhoff, M.; Giewekemeyer, K.; Salditt, T. [Institut fuer Roentgenphysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Liese, T.; Radisch, V.; Krebs, H. U. [Institut fuer Materialphysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2012-03-15

    We have used a combined optical system of a high gain elliptic Kirkpatrick-Baez mirror system (KB) and a multilayer Laue lens (MLL) positioned in the focal plane of the KB for hard x-rays nano-focusing. The two-step focusing scheme is based on a high acceptance and high gain elliptical mirror with moderate focal length and a MLL with ultra-short focal length. Importantly, fabrication constraints, i.e. in mirror polishing and bending, as well as MLL deposition can be significantly relaxed, since (a) the mirror focus in the range of 200-500 nm is sufficient, and (b) the number of layers of the MLL can be correspondingly small. First demonstrations of this setup at the coherence beamline of the PETRA III storage ring yield a highly divergent far-field diffraction pattern, from which the autocorrelation function of the near-field intensity distribution was obtained. The results show that the approach is well suited to reach smallest spot sizes in the sub-10nm range at high flux.

  14. [The artificial lens: the folly of yesterday, the standard of today].

    Science.gov (United States)

    Meur, G

    1999-01-01

    Traditional cataract operation (dislocation of the crystalline lens into the vitreous body by external pressure or by needling) is nearly as old as mankind. The idea of implanting an artificial lenticulus is not new but this was only performed for the first time in 1949. In the last 50 years, a better knowledge of corneal and retinal physiology, as well as the improvements of intraocular lens material and design, have led to very safe routine surgery.

  15. Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

    Science.gov (United States)

    Pintwala, Robert; Postnikoff, Cameron; Molladavoodi, Sara; Gorbet, Maud

    2015-03-01

    Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal biocompatibility, specifically through the quantification of cell-surface markers of leukocyte activation.

  16. 两种不同攀设计非球面人工晶状体伪调节相关研究%Changes of pseudophakic accommodation of aspheric intraocular lens designs in phacoemulsification

    Institute of Scientific and Technical Information of China (English)

    赵玉琴; 李英俊; 金龙山

    2015-01-01

    Objective To compare the pseudophakic accommodation of different designs of aspheric intraocular lens (IOL) in phacoemulsification.Methods One hundred and twenty-six eyes with cataract surgery were randomized into 2 groups:an Acrysof IQ SN60WF (Alcon Laboratories,Fort Worth,Texas,USA) IOL group (59 eyes) and Akreos Adapt AO (Bausch & Lomb.,Rochester,NY,USA)IOL group (67 eyes).Patients were examined using anterior segment optical coherence tomography (AS-OCT),including anterior chamber depth (ACD),pupil diameter,and amplitude of pseudophakic accommodation,preoperatively and 6 months postoperatively.Results The IQ IOLs and AO IOLs group of mean pseudophakic accommodation was (1.26±0.34)D and (1.09±0.51)D,respectively,there was statistically significantly different (t =2.314,P =0.041).The mean pupil diameter measurements for IQ group and AO IOL group were (0.52±0.20)mm and (0.49±0.16)mm,respectively,which showed no statistically significant differences (t =0.946,P =0.541).The amplitude of pseudophakic accommodation was negative correlated with pupil diameter (r =-0.651,P =0.024).Conclusions The movement of aspheric IOLs in eyes after cataract surgery is an important mechanism for attaining good near vision without additional correction,2-point haptic design IOLs provide better pseudophakic accommodation than that of Four-point haptic designs.%目的 比较两种不同攀设计的非球面人工晶状体在囊袋内植入后伪调节力的差异.方法 临床病例对照研究.选择2012年5~12月在延边大学附属医院眼科行超声乳化白内障摘除联合人工晶状体植入术的老年性白内障患者82例(126只眼),应用随机数字表法髓机分为两组,SN60WF为IQ组植入“L”形Acrysof IQ SN60WF (Alcon Laboratories,Fort Worth,Texas,USA)人工晶状体(59只眼);Adapt AO为AO组植入一体四点Akreos Adapt AO (Bausch&Lomb,Rochester,NY,USA)人工晶状体(67只眼).采用眼前段光学相干断层扫描仪(AS-OCT)实时测量人工晶

  17. The Simulation and Optimization of Aspheric Plastic Lens Injection Molding

    Institute of Scientific and Technical Information of China (English)

    WEN Jialing; WEN Pengfei

    2005-01-01

    For the purpose of reducing the volumetric shrinkage and volumetric shrinkage variation, the process in injection molding of aspheric plastic lens was simulated, and several process parameters which include holding pressure, melt temperature, mold temperature, fill time, holding pressure time and cooling time were optimized by using an orthogonal experimental design method. Finally, the optimum process parameters and the influence degree of process parameters on the average volumetric shrinkage and the volumetric shrinkage variation are obtained.

  18. Cellulose/polyvinyl alcohol-based hydrogels for reconfigurable lens

    Science.gov (United States)

    Jayaramudu, T.; Ko, Hyun-U.; Gao, Xiaoyuan; Li, Yaguang; Kim, Sang Youn; Kim, Jaehwan

    2016-04-01

    Electroactive hydrogels are attractive for soft robotics and reconfigurable lens applications. Here we describe the design and fabrication of cellulose-poly vinyl alcohol based hydrogels. The fabricated hydrogels were confirmed by Fourier transformer spectroscopy, swelling studies, thermal analysis, surface morphology of fabricated hydrogel was study by using scanning electron microscopy. The effect of poly vinyl alcohol concentration on the optical and electrical behavior of hydrogels was studied.

  19. Paediatric intraocular lens implants: accuracy of lens power calculations.

    Science.gov (United States)

    O'Gallagher, M K; Lagan, M A; Mulholland, C P; Parker, M; McGinnity, G; McLoone, E M

    2016-09-01

    PurposeThis study aims to evaluate the accuracy of lens prediction formulae on a paediatric population.MethodsA retrospective case-note review was undertaken of patients under 8 years old who underwent cataract surgery with primary lens implantation in a regional referral centre for paediatric ophthalmology, excluding those whose procedure was secondary to trauma. Biometric and refractive data were analysed for 43 eyes, including prediction errors (PE). Statistical measures used included mean absolute error (MAE), median absolute error (MedAE), Student's t-test and Lin's correlation coefficient.ResultsThe mean PE using the SRK-II formula was +0.96 D (range -2.47D to +2.41 D, SD 1.33 D, MAE 1.38 D, MedAE 1.55, n=15). The mean PE was smaller using SRK/T (-0.18 D, range -3.25 D to +3.95 D, SD 1.70 D, MAE 1.30 D, MedAE 1.24, n=27). We performed an analysis of the biometry data using four different formula (Hoffer Q, Holladay 1, SRK-II and SRK/T). Hoffer Q showed a smaller MedAE than other formulae but also a myopic bias.ConclusionOur clinical data suggest SRK/T was more accurate in predicting post-operative refraction in this cohort of paediatric patients undergoing cataract surgery. Hoffer Q may have improved accuracy further.

  20. Magnetic field, temperature and mechanical crack performance of a GdBCO magnetic lens

    Science.gov (United States)

    Zhang, Z. Y.; Matsumoto, S.; Teranishi, R.; Kiyoshi, T.

    2012-11-01

    Magnetic field concentration by using the diamagnetism of a superconductor is a novel technique that has been experimentally demonstrated in magnetic lenses. A magnetic lens consists of a hollow superconductor cylinder with a tapered inner diameter within which the magnetic flux is concentrated by diamagnetism. Magnetic lenses are very promising for use in compact high magnetic field systems. However, magnetic lenses with large inner diameters are required to facilitate sample access during use. In this study, an optimized GdBaCuO magnetic lens with large inner and outer diameters was designed and its performance was investigated in liquid nitrogen, liquid helium, and a cryocooler-cooled cryostat. A lens with an inner diameter of 12 mm was constructed by stacking three specially machined GdBaCuO bulk pieces. This magnetic lens cracked due to the large flux jump that occurred when the concentrated field of the magnetic lens exceeded 10 T at 4.2 K. The cracked lens was subsequently impregnated with epoxy resin. A concentrated field of 12.42 T was realized when the background field was 8 T at 20 K and no flux jumps occurred. This result demonstrates that this GdBCO magnetic lens is promising for use in compact superconducting magnet systems.

  1. An acoustic Maxwell’s fish-eye lens based on gradient-index metamaterials

    Science.gov (United States)

    Yuan, Bao-guo; Tian, Ye; Cheng, Ying; Liu, Xiao-jun

    2016-10-01

    We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging. Project supported by the National Basic Research Program of China (Grant No. 2012CB921504), the National Natural Science Foundation of China (Grant Nos. 11574148, 11474162, 1274171, 11674172, and 11674175), and the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant Nos. 20110091120040 and 20120091110001).

  2. Flat lens for seismic waves

    CERN Document Server

    Brule, Stephane; Guenneau, Sebastien

    2016-01-01

    A prerequisite for achieving seismic invisibility is to demonstrate the ability of civil engineers to control seismic waves with artificially structured soils. We carry out large-scale field tests with a structured soil made of a grid consisting of cylindrical and vertical holes in the ground and a low frequency artificial source (< 10 Hz). This allows the identification of a distribution of energy inside the grid, which can be interpreted as the consequence of an effective negative refraction index. Such a flat lens reminiscent of what Veselago and Pendry envisioned for light opens avenues in seismic metamaterials to counteract the most devastating components of seismic signals.

  3. Atom lens without chromatic aberrations

    CERN Document Server

    Efremov, Maxim A; Schleich, Wolfgang P

    2012-01-01

    We propose a lens for atoms with reduced chromatic aberrations and calculate its focal length and spot size. In our scheme a two-level atom interacts with a near-resonant standing light wave formed by two running waves of slightly different wave vectors, and a far-detuned running wave propagating perpendicular to the standing wave. We show that within the Raman-Nath approximation and for an adiabatically slow atom-light interaction, the phase acquired by the atom is independent of the incident atomic velocity.

  4. Intraocular lens with accommodation capacity

    OpenAIRE

    Dorronsoro, Carlos; Alejandre, Nicolás; Bekesi, Nandor; Marcos, Susana

    2014-01-01

    Intraocular lens with accommodation capacity comprising a first optical member (1) having a dynamic optical power, to which a second optical member (2) with a fixed optical power is affixed, in such a manner that at least a central part of each of one of one of the curved surfaces (2a, 2b) of the second optical member (2) and of at least one of the surfaces (1a, 1b) of the first optical member (1) are in contact with each other, the second optical member (2) and the first optical member (1) p...

  5. Optical performance of a PDMS tunable lens with automatically controlled applied stress

    Science.gov (United States)

    Cruz-Felix, Angel S.; Santiago-Alvarado, Agustín.; Hernández-Méndez, Arturo; Reyes-Pérez, Emilio R.; Tepichín-Rodriguez, Eduardo

    2016-09-01

    The advances in the field of adaptive optics and in the fabrication of tunable optical components capable to automatically modify their physical features are of great interest in areas like machine vision, imaging systems, ophthalmology, etc. Such components like tunable lenses are used to reduce the overall size of optical setups like in small camera systems and even to imitate some biological functions made by the human eye. In this direction, in the last years we have been working in the development and fabrication of PDMS-made tunable lenses and in the design of special mechanical mounting systems to manipulate them. A PDMS-made tunable lens was previously designed by us, following the scheme reported by Navarro et al. in 1985, in order to mimic the accommodation process made by the crystalline lens of the human eye. The design included a simulation of the application of radial stress onto the lens and it was shown that the effective focal length was indeed changed. In this work we show the fabrication process of this particular tunable lens and an optimized mechanism that is able to automatically change the curvature of both surfaces of the lens by the application of controlled stress. We also show results of a study and analysis of aberrations performed to the Solid Elastic Lens (SEL).

  6. Contact lens intolerance: refitting with dual axis lens for corneal refractive therapy

    Science.gov (United States)

    López-López, María; Pelegrín-Sánchez, José Miguel; Sobrado-Calvo, Paloma; García-Ayuso, Diego

    2011-01-01

    Corneal refractive therapy is a non-surgical procedure whose main purpose is to improve uncorrected visual acuity during the day, without spectacles or contact lenses. We report an adult woman who shows contact lens intolerance and does not want to wear eyeglasses. We used dual axis contact lens to improve lens centration. We demonstrate a maintained unaided visual acuity during one year of treatment. In conclusion, we can consider refitting with dual axis lens for corneal refractive therapy as a non-surgical option for patients who show contact lens intolerance.

  7. Fabricating customized hydrogel contact lens

    Science.gov (United States)

    Childs, Andre; Li, Hao; Lewittes, Daniella M.; Dong, Biqin; Liu, Wenzhong; Shu, Xiao; Sun, Cheng; Zhang, Hao F.

    2016-10-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spectra range from 400 nm to 800 nm. The Young’s modulus (1.47 MPa) and hydrophobicity (with a sessile drop contact angle of 40.5°) have also been characterized experimentally. Retinal imaging using optical coherence tomography in rats wearing our customized contact lenses has the quality comparable to the control case without the contact lens. Our method could significantly reduce the cost and the lead time for fabricating soft contact lenses with customized shapes, and benefit the laboratorial-used contact lenses in pre-clinical studies.

  8. Plasma Lens for Muon and Neutrino Beams

    Energy Technology Data Exchange (ETDEWEB)

    Kahn,S.A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J.C.; Hershcovitch, A.; Johnson, B.M.

    2008-06-23

    The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented.

  9. Liquid lens using acoustic radiation force.

    Science.gov (United States)

    Koyama, Daisuke; Isago, Ryoichi; Nakamura, Kentaro

    2011-03-01

    A liquid lens is proposed that uses acoustic radiation force with no mechanical moving parts. It consists of a cylindrical acrylic cell filled with two immiscible liquids (degassed water and silicone oil) and a concave ultrasound transducer. The focal point of the transducer is located on the oil-water interface, which functions as a lens. The acoustic radiation force is generated when there is a difference in the acoustic energy densities of different media. An acoustic standing wave was generated in the axial direction of the lens and the variation of the shape of the oil-water interface was observed by optical coherence tomography (OCT). The lens profile can be rapidly changed by varying the acoustic radiation force from the transducer. The kinematic viscosity of silicone oil was optimized to minimize the response times of the lens. Response times of 40 and 80 ms when switching ultrasonic radiation on and off were obtained with a kinematic viscosity of 200 cSt. The path of a laser beam transmitted through the lens was calculated by ray-tracing simulations based on the experimental results obtained by OCT. The transmitted laser beam could be focused by applying an input voltage. The liquid lens could be operated as a variable-focus lens by varying the input voltage.

  10. Metasurface lens: Shrinking the camera size

    Science.gov (United States)

    Sun, Cheng

    2017-01-01

    A miniaturized camera has been developed by integrating a planar metasurface lens doublet with a CMOS image sensor. The metasurface lens doublet corrects the monochromatic aberration and thus delivers nearly diffraction-limited image quality over a wide field of view.

  11. 不同设计多焦点人工晶状体植入术后视觉质量的比较%Comparison of postoperative visual quality with different multifocal intraocular lens designs

    Institute of Scientific and Technical Information of China (English)

    宋慧; 汤欣; 邢晓杰

    2012-01-01

    Objective To compare postoperative visual function and quality after 3 different multifocal intraocular lenses (MIOLs) were implanted:REZOOM (refractive MIOL),Tecnis ZMA00 (all optical diffractive MIOL) and Acri.Lisa 366D (refractive diffractive MIOL).Methods This was a prospective case-control study.Forty eyes of 29 patients who underwent cataract phacoemulsification and MIOL implantation in Tianjin Eye Hospital cataract center were selected from September 2008 to March 2010.Fifteen eyes were implanted with REZOOM,12 eyes with Tecnis ZMAO0,and 13 eyes with Acri.Lisa 366D.Patients were reviewed after 3 months or more following surgery.Colenbrander Mixed Contrast Card Set vision test cards were used to measure intermediate and near visual acuity under the best corrected distance visual acuity.Then iTrace visual function analyzer checks were used to plot 5,10,15,20,25,and 30 c/d for modulation transfer function (MTF) and to measure intraocular aberrations as well as pupil diameter.Data were analyzed using a one-way ANOVA.Results The differences in best corrected distance,intermediate,near visual acuity among the 3 groups were not statistically significant.Three months or more after MIOL implantation,all examined patients from the 3 groups had best corrected distance visual acuity with 20/25 or better visual acuity.Forty-seven percent,42% and 54% patients in REZOOM,ZMA00 and Acri.Lisa 366D groups had intermediate visual acuities with 20/25 or better under the best corrected distance visual acuity.In corresponding group,13%,31% and 50% with 20/25 or better best corrected near visual acuity.Exccept for trefoil,There were statistically significant differences among the 3 groups in spherical and coma aberrations compared with the spherical intraocular lens (IOL) (Ar40e) and Tetraflex IOL.There were no statistically significant differences in MTF among the 3 groups except at 5 c/d.Conclusion The differences among the 3 MIOLs for far visual acuity after surgery

  12. Luneburg lens with extended flat focal surface for electronic scan applications.

    Science.gov (United States)

    Li, Ying; Zhu, Qi

    2016-04-01

    Luneburg lens with flat focal surface has been developed to work together with planar antenna feeds for beam steering applications. According to our analysis of the conventional flattened Luneburg lens, it cannot accommodate enough feeding elements which can cover its whole scan range with half power beamwidths (HPBWs). In this paper, a novel Luneburg lens with extended flat focal surface is proposed based on the theory of Quasi-Conformal Transformation Optics (QCTO), with its beam steering features reserved. To demonstrate this design, a three-dimensional (3D) prototype of this novel extend-flattened Luneburg lens working at Ku band is fabricated based on 3D printing techniques, whose flat focal surface is attached to a 9-element microstrip antenna array to achieve different scan angles. Our measured results show that, with different antenna elements being fed, the HPBWs can cover the whole scan range.

  13. Novel switching mode in a vertically aligned liquid crystal contact lens.

    Science.gov (United States)

    Syed, Ishtiaque M; Kaur, Sarabjot; Milton, Harry E; Mistry, Devesh; Bailey, James; Morgan, Philip B; Jones, J Cliff; Gleeson, Helen F

    2015-04-20

    Liquid crystal (LC) contact lenses are emerging as an exciting technology for vision correction. A homeotropically (vertical) aligned LC lens is reported that offers improved optical quality and simplified construction techniques over previously reported LC contact lens designs. The lens has no polarization dependence in the off state and produces a continuous change in optical power of up to 2.00 ± 0.25 D with a voltage applied. The variation in optical power results from the voltage-induced change in refractive index of the nematic LC layer, from 1.52 to a maximum of 1.72. One device substrate is treated with an alignment layer that is a mixture of planar and homeotropic polyimides, rubbed to induce a preferred director orientation in the switched state. Defects that could occur during switching are thus avoided and the lens exhibits excellent optical quality with a continuous variation in focal power.

  14. Far-field characteristics of the square grooved-dielectric lens antenna for the terahertz band.

    Science.gov (United States)

    Pan, Wu; Zeng, Wei

    2016-09-10

    In order to improve the gain and directionality of a terahertz antenna, a square grooved-dielectric lens antenna based on a Fresnel zone plate is proposed. First, a diagonal horn, which is adopted as the primary feed antenna, is designed. Then, the far-field characteristics of the lens antenna are studied by using Fresnel-Kirchhoff diffraction theory and the paraxial approximation. The effects of the full-wave period, the focus diameter ratio, the subregion, and the dielectric substrate thickness on radiation characteristics are studied. The experimental results show that the proposed lens antenna has axisymmetric radiation patterns. The gain is over 26.1 dB, and the 3 dB main lobe beam width is lower than 5.6° across the operation band. The proposed lens antenna is qualified for applications in terahertz wireless communication systems.

  15. Bacterial assay of contact lens wearers.

    Science.gov (United States)

    Hart, D E; Hosmer, M; Georgescu, M; Farris, R L

    1996-03-01

    The goal of the project was to determine the quantity of bacteria on the contact lens and adjacent areas of the eye. This paper is a quantitative study of the contact lens and ocular aerobic microbiota in a mixed group of daily and extended wear disposable contact lens users. The contact lens, the lower fornix, tears collecting at the lower fornix, and edge of the lower lid at the Meibomian gland margin were assayed for the quantity of bacterial colony forming units (CFU). Eighteen patients wearing 49 disposable high water content hydrogel contact lenses were assayed and the mean lens age was 8.8 +/- 4.6 days. Three patients wore their lenses on a daily wear basis and 15 on an extended wear schedule. Tear samples were obtained with sterile microbial loops and the lens was macerated into small particles with a tissue grinder. The samples were poured onto the surface of chocolate agar plates and incubated at 35 degrees C for 48 h in 5% Co2. The lid margin revealed the greatest bacterial presence (mean = 9.7 CFU; median = 2 CFU; mode = 0 CFU). The lens showed the next greatest presence of CFU (mean = 4.5 CFU; median = 1 CFU; mode = 0). The fornix and tears revealed the least bacterial presence (fornix: mean = 2.6 CFU; median = 0 CFU; mode = 0 CFU). The bacteria were coagulase-negative staphylococci. The bacterial assay of disposable lens wearing contact lens subjects indicates that the lid margins are the greatest source of bacteria with the tears being the lowest. These studies support the concept that in the eye, the lens typically does not possess a large number of bacteria under normal conditions.

  16. Effects of High Volume MOSFET Usage on Dosimetry in Pediatric CT, Pediatric Lens of the Eye Dose Reduction Using Siemens Care kV, & Designing Quality Assurance of a Cesium Calibration Source

    Science.gov (United States)

    Smith, Aaron Kenneth

    taking the standard deviation of a large regions of interest in both the lung and the soft tissue of the chest to measure the noise. Results: The proof of concept experiment found that the main cable of the MOSET, not the ends closest to the reading tip, is the most attenuating part of the cable. The proof of concept also found that increasing the number of MOSFET layers to 1, 2, 3, and 4 layers decreased the dose to the center of the phantom by 17.92, 28.04, 39.98, 42.49% respectively. Increasing the percent of the block phantom covered to 10, 30, and 50% coverage decreased the dose to the center of the phantom by 17.92, 17.80, and 18.17% respectively. Project 2: Pediatric Lens of the Eye Dose Reduction Using Siemens Care kV: Purpose: The Siemens Care kV is a software that recommends a tube potential (kV) setting for CT scans based on the thickness of the anatomy being scanned in order to reduce dose on a patient to patient basis. Pediatric cranial scans at Duke do not use this software nor do they use tube current modulation. Dose to the lens of the eye in pediatric patients can lead to lens opacity later in life [10]. The goal of this project was to determine if Care kV can be used in pediatric cranial scans to reduce the dose to the lens of the eye while maintaining adequate image quality. Materials and Methods: A Siemens SOMATOM Force CT scanner performing a routine cranial scan protocol was used in concert with two Atom Dosimetry Phantoms (1-year-old and 5-year-old) and MOSFET dosimeters to determine the effect changing the reference tube potential of the Care kV software would have on dose and image quality (measured with CNR). The settings used with Care kV were off, and semi reference tube potential 120, 110, and 100 kV. Results: Dose to the lens of the eye was reduced for the 1-year old phantom by 9.601, 17.572, and 19.724% by using Care kV with tube potential set to 120, 110 and 100 kV respectively. Dose to the lens of the eye was reduced for the 5-year old

  17. A study for the special Fresnel lens for high efficiency solar concentrators

    Science.gov (United States)

    Lin, Jian-Shian; Huang, Wei-Chih; Hsu, Hsiu-Chen; Chang, Ming-Wen; Liu, Chung-Ping

    2005-08-01

    Design a Fresnel lens for a concentrator to collect more sunlight onto the solar cell due to the efficiency and cost. Since 1970, the non-imaging concentrator was used for solar energy; most of them were reflecting mirrors. The non-imaging optical system provides large aperture and forgiving imaging requirements. The Fresnel lens used in non-imaging optical system was usually called non-imaging Fresnel lens. In this research, the Fresnel lenses were refracting optical elements but diffracting ones. According to the method of Ralf Leutz and Akio Suzuki [2], using minimum deviation and minimum dispersion to design a non-imaging Fresnel lens, which obeys the edge ray principle. Use optical software TracePro to simulate the non-imaging Fresnel lens, and each pitch size was 0.3mm and 200mm focus distant. Discusses the losses of non-imaging Fresnel lens and find out the relation of efficiency and F-Number. The optical concentration ratio could reach 15X (2-D) and 230X (3-D).

  18. Symmetrical optical imaging system with bionic variable-focus lens for off-axis aberration correction

    Science.gov (United States)

    Wang, Xuan-Yin; Du, Jia-Wei; Zhu, Shi-Qiang

    2017-09-01

    A bionic variable-focus lens with symmetrical layered structure was designed to mimic the crystalline lens. An optical imaging system based on this lens and with a symmetrical structure that mimics the human eye structure was proposed. The refractive index of the bionic variable-focus lens increases from outside to inside. The two PDMS lenses with a certain thickness were designed to improve the optical performance of the optical imaging system and minimise the gravity effect of liquid. The paper presents the overall structure of the optical imaging system and the detailed description of the bionic variable-focus lens. By pumping liquid in or out of the cavity, the surface curvatures of the rear PDMS lens were varied, resulting in a change in the focal length. The focal length range of the optical imaging system was 20.71-24.87 mm. The optical performance of the optical imaging system was evaluated by imaging experiments and analysed by ray tracing simulations. On the basis of test and simulation results, the optical performance of the system was quite satisfactory. Off-axis aberrations were well corrected, and the image quality was greatly improved.

  19. Microwave Nondestructive Evaluation of Dielectric Materials with a Metamaterial Lens

    Science.gov (United States)

    Shreiber, Daniel; Gupta, Mool; Cravey, Robin L.

    2008-01-01

    A novel microwave Nondestructive Evaluation (NDE) sensor was developed in an attempt to increase the sensitivity of the microwave NDE method for detection of defects small relative to a wavelength. The sensor was designed on the basis of a negative index material (NIM) lens. Characterization of the lens was performed to determine its resonant frequency, index of refraction, focus spot size, and optimal focusing length (for proper sample location). A sub-wavelength spot size (3 dB) of 0.48 lambda was obtained. The proof of concept for the sensor was achieved when a fiberglass sample with a 3 mm diameter through hole (perpendicular to the propagation direction of the wave) was tested. The hole was successfully detected with an 8.2 cm wavelength electromagnetic wave. This method is able to detect a defect that is 0.037 lambda. This method has certain advantages over other far field and near field microwave NDE methods currently in use.

  20. Formation flying for a Fresnel lens observatory mission

    CERN Document Server

    Krizmanic, J; Gehrels, N; Krizmanic, John; Skinner, Gerry; Gehrels, Neil

    2006-01-01

    The employment of a large area Phase Fresnel Lens (PFL) in a gamma-ray telescope offers the potential to image astrophysical phenomena with micro-arcsecond angular resolution. In order to assess the feasibility of this concept, two detailed studies have been conducted of formation flying missions in which a Fresnel lens capable of focussing gamma-rays and the associated detector are carried on two spacecraft separated by up to 10$^6$ km. These studies were performed at the NASA Goddard Space Flight Center Integrated Mission Design Center (IMDC) which developed spacecraft, orbital dynamics, and mission profiles. The results of the studies indicated that the missions are challenging but could be accomplished with technologies available currently or in the near term. The findings of the original studies have been updated taking account of recent advances in ion thruster propulsion technology.

  1. Mechanical Design Report DARPA BOSS Program

    Science.gov (United States)

    2008-03-21

    had been learned. Design mechanical components based on optical design Provide feedback to optical designers Provide feedback to optical...Components Lens Evaluation CWRU Incorporate feedback in design Develop new lens structures and fabrication techniques Incorporate feedback in...zoom process. Effective focal length ( EFL ) was used as the independent variable because it is tied directly to the image magnification (zoom), and

  2. Focusing high-energy x-rays by a PMMA compound x-ray lens on Beijing synchrotron radiation facility

    Institute of Scientific and Technical Information of China (English)

    Le Zi-Chun; Liang Jing-Qiu; Dong Wen; Zhu Pei-Ping; Peng Liang-Qiang; Wang Wei-Biao; Huang Wan-Xia; Yuan Qing-Xi; Wang Jun-Yue

    2007-01-01

    The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors' recent research on a polymethyl methacrylate (PMMA) compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.

  3. Stretched Lens Array (SLA) Photovoltaic Concentrator Hardware Development and Testing

    Science.gov (United States)

    Piszczor, Michael; O'Neill, Mark J.; Eskenazi, Michael

    2003-01-01

    Over the past two years, the Stretched Lens Array (SLA) photovoltaic concentrator has evolved, under a NASA contract, from a concept with small component demonstrators to operational array hardware that is ready for space validation testing. A fully-functional four panel SLA solar array has been designed, built and tested. This paper will summarize the focus of the hardware development effort, discuss the results of recent testing conducted under this program and present the expected performance of a full size 7kW array designed to meet the requirements of future space missions.

  4. Planoconcave lens by negative refraction of stacked subwavelength hole arrays.

    Science.gov (United States)

    Beruete, M; Navarro-Cía, M; Sorolla, M; Campillo, I

    2008-06-23

    This work presents the design of a planoconcave parabolic negative index metamaterial lens operating at millimeter wavelengths fabricated by using stacked subwavelength hole arrays. A staircase approximation to the ideal parabola profile has been done by removing step by step one lattice in each dimension of the transversal section. Theory predicts power concentration at the focal point of the parabola when the refractive index equals -1. Both simulation and measurement results exhibit an excellent agreement and an asymmetrical focus has been observed. The possibility to design similar planoconcave devices in the terahertz and optical wavelengths could be a reality in the near future.

  5. New trends in intraocular lens imaging

    Science.gov (United States)

    Millán, María S.; Alba-Bueno, Francisco; Vega, Fidel

    2011-08-01

    As a result of modern technological advances, cataract surgery can be seen as not only a rehabilitative operation, but a customized procedure to compensate for important sources of image degradation in the visual system of a patient, such as defocus and some aberrations. With the development of new materials, instruments and surgical techniques in ophthalmology, great progress has been achieved in the imaging capability of a pseudophakic eye implanted with an intraocular lens (IOL). From the very beginning, optical design has played an essential role in this progress. New IOL designs need, on the one hand, theoretical eye models able to predict optical imaging performance and on the other hand, testing methods, verification through in vitro and in vivo measurements, and clinical validation. The implant of an IOL requires a precise biometry of the eye, a prior calculation from physiological data, and an accurate position inside the eye. Otherwise, the effects of IOL calculation errors or misplacements degrade the image very quickly. The incorporation of wavefront aberrometry into clinical ophthalmology practice has motivated new designs of IOLs to compensate for high order aberrations in some extent. Thus, for instance, IOLs with an aspheric design have the potential to improve optical performance and contrast sensitivity by reducing the positive spherical aberration of human cornea. Monofocal IOLs cause a complete loss of accommodation that requires further correction for either distance or near vision. Multifocal IOLs address this limitation using the principle of simultaneous vision. Some multifocal IOLs include a diffractive zone that covers the aperture in part or totally. Reduced image contrast and undesired visual phenomena, such as halos and glare, have been associated to the performance of multifocal IOLs. Based on a different principle, accommodating IOLs rely on the effort of the ciliary body to increase the effective power of the optical system of the

  6. Noncontact optical measurement of lens capsule thickness ex vivo

    Science.gov (United States)

    Ziebarth, Noel M.; Manns, Fabrice; Uhlhorn, Stephen; Parel, Jean-Marie

    2004-07-01

    Purpose: To design a non-contact optical system to measure lens capsule thickness in cadaver eyes. Methods: The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused onto the tissue using an aspheric lens (NA=0.68) mounted on a motorized translation stage. Light reflected from the sample is collected by the fiber coupler and sent to a silicon photodiode connected to a power meter. Peaks in the power signal are detected when the focal point of the aspheric lens coincides with the capsule boundaries. The capsule thickness is proportional to the distance between successive peaks. Anterior and posterior lens capsule thickness measurements were performed on 13 human, 10 monkey, and 34 New Zealand white rabbit lenses. The cadaver eyes were prepared for optical measurements by bonding a PMMA ring on the sclera. The posterior pole was sectioned, excess vitreous was removed, and the eye was placed on a Teflon slide. The cornea and iris were then sectioned. After the experiments, the lenses were excised, placed in 10% buffered formalin, and prepared for histology. Results: Central anterior lens capsule thickness was 9.4+/-2.9μm (human), 11.2+/-6.6μm (monkey), and 10.3+/-3.6μm (rabbit) optically and 14.9+/-1.6μm (human), 17.7+/-4.9μm (monkey), and 12.6+/-2.3μm (rabbit) histologically. The values for the central posterior capsule were 9.4+/-2.9μm (human), 6.6+/-2.5μm (monkey), and 7.9+/-2.3μm (rabbit) optically and 4.6+/-1.4μm (human), 4.5+/-1.2μm (monkey), and 5.7+/-1.7μm (rabbit) histologically. Conclusions: This study demonstrates that a non-contact optical system can successfully measure lens capsule thickness in cadaver eyes.

  7. Advances in lenticular lens arrays for visual display

    Science.gov (United States)

    Johnson, R. Barry; Jacobsen, Gary A.

    2005-08-01

    Lenticular lens arrays are widely used in the printed display industry and in specialized applications of electronic displays. In general, lenticular arrays can create from interlaced printed images such visual effects as 3-D, animation, flips, morph, zoom, or various combinations. The use of these typically cylindrical lens arrays for this purpose began in the late 1920's. The lenses comprise a front surface having a spherical crosssection and a flat rear surface upon where the material to be displayed is proximately located. The principal limitation to the resultant image quality for current technology lenticular lenses is spherical aberration. This limitation causes the lenticular lens arrays to be generally thick (0.5 mm) and not easily wrapped around such items as cans or bottles. The objectives of this research effort were to develop a realistic analytical model, to significantly improve the image quality, to develop the tooling necessary to fabricate lenticular lens array extrusion cylinders, and to develop enhanced fabrication technology for the extrusion cylinder. It was determined that the most viable cross-sectional shape for the lenticular lenses is elliptical. This shape dramatically improves the image quality. The relationship between the lens radius, conic constant, material refractive index, and thickness will be discussed. A significant challenge was to fabricate a diamond-cutting tool having the proper elliptical shape. Both true elliptical and pseudo-elliptical diamond tools were designed and fabricated. The plastic sheets extruded can be quite thin (< 0.25 mm) and, consequently, can be wrapped around cans and the like. Fabrication of the lenticular engraved extrusion cylinder required remarkable development considering the large physical size and weight of the cylinder, and the tight mechanical tolerances associated with the lenticular lens molds cut into the cylinder's surface. The development of the cutting tool and the lenticular engraved

  8. PMMA lens with high efficiency and reliability

    Science.gov (United States)

    Matsuzaki, Ichiro; Abe, Koji; Fujita, Katsuhiro

    2013-09-01

    Polymethyl Methacrylate (PMMA) Fresnel lenses are increasingly being used in concentrated photovoltaic (CPV) systems installed outdoors and, accordingly, emphasis is being placed on the durability of such lenses with regard to light transmittance when subject to ultraviolet (UV) light and dust exposure. Accelerated testing methods for evaluating durability under UV exposure were established, allowing development of a lens material with improved UV resistance. Simultaneously, through a proprietary molding method, a Fresnel lens that boasts favorable light concentration efficiency with little deformation even after prolonged outdoor use was developed. Moreover, the lens incorporates a new hard-coat finish that possesses sand durability and UV resistance comparable to that of tempered glass.

  9. Vitreous Humor Changes Expression of Iron-Handling Proteins in Lens Epithelial Cells

    Science.gov (United States)

    Goralska, Malgorzata; Fleisher, Lloyd N.; McGahan, M. Christine

    2017-01-01

    Purpose In humans, vitrectomy is associated with development of nuclear cataracts. Iron catalyzes free radical formation causing oxidative damage, which is implicated in cataract formation. This study was designed to determine if vitreous humor, which can initiate differentiation of lens epithelial cells, would have an effect on iron-handling proteins. Methods Cultured canine lens epithelial cells were treated with collected canine vitreous humor. Lysates of treated and control cells were separated by SDS-PAGE. Ferritin H- and L-chains, transferrin receptor 1, and aquaporin 0 were immunodetected and quantitated with specific antibodies. Morphologic changes in treated cells were assessed. Results Treatment of lens epithelial cells with a 33% (vol/vol) solution of vitreous humor changed the morphology of lens cells and induced expression of aquaporin 0, a marker of fiber cell differentiation that was undetectable in control cells. Treatment did not modify the size of iron-handling proteins but significantly increased content of ferritin from 2.9- to 8.8-fold over control and decreased levels of transferrin receptor by 37% to 59%. Conclusions Vitreous humor may significantly limit iron uptake by transferrin/transferrin receptor pathway, and by increasing ferritin levels could profoundly increase the iron-storage capacity of ferritin in lens cells. Vitreous humor may play a significant protective role against iron-catalyzed oxidative damage of lens epithelial cells and therefore in the formation of cataracts. PMID:28245299

  10. Alignment tolerant expanded beam connector based on a gapless fiber-lens interface.

    Science.gov (United States)

    Lee, Yong-Geon; Park, Chang-Hyun; Back, Seon-Woo; Kim, Haeng-Jeong; Lee, Sang-Shin

    2016-01-10

    An expanded beam connector (EBC) has been proposed and realized, where a single-mode fiber is seamlessly integrated with a ball lens exhibiting a near-zero back focal length (BFL) so that the incoming small mode exiting the fiber translates into an enlarged collimated beam via the lens. The structural tolerance for the fiber-optic connector is primarily relaxed by relieving the restrictions imposed on the meticulous control of the gap between the lens and the fiber. The EBC has been designed through rigorous ray-optic simulations and then constructed based on a ball lens in LASF35 (n=∼1.98 at λ=1.3  μm), exhibiting an ultrashort BFL of ∼13  μm. It was practically confirmed that an input mode of a ∼10  μm spot relating to the single-mode fiber could be efficiently converted into a highly collimated beam of a ∼350  μm spot that emanates from the ball lens, leading to a 35-fold beam expansion. The alignment tolerance for the fiber as well as the connector unit was scrutinized with respect to the angular tilt and transverse displacement. The measured insertion loss for the EBC, allowing for no separation between the fiber and ball lens, was slightly over 0.8 dB.

  11. A novel application of a Fresnel lens for a solar stove and solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Valmiki, M.M.; Li, Peiwen; Heyer, Javier; Morgan, Matthew; Albinali, Abdulla; Alhamidi, Kamal; Wagoner, Jeremy [Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, AZ 85721 (United States)

    2011-05-15

    This paper presents a novel design and the prototyped solar cooking stove which uses a large Fresnel lens for the concentration of sunlight. The technology demonstrates high safety and efficiency of solar cooking and heating using Fresnel lenses which are low cost and available from off-the-shelf. The stove has a fixed heat-receiving area located at the focal point of the lens. The sunlight tracking system rotates the Fresnel lens about its focal point in both zenith and azimuth angles. The tracking is accomplished through a revolving motion of two rotation arms that hold the lens and a horizontal rotation of a platform that the lens system stands on. The rotation of the arms tracks the sunlight in zenith plane, while the rotation of the platform tracks in the azimuth plane. Since the solar tracking allows the Fresnel lens to concentrate sunlight to a fixed small heat-receiving area, relatively low heat loss and high energy efficiency is made possible. The heat is used to maintain a stovetop surface at temperatures around as high as 300 C, which is practical for cooking applications in a very safe, user-friendly, and convenient manner. The system also demonstrates the possibility of transferring heat using a working fluid for indoor heating and cooking. Wider applications using the system for solar thermal collection and utilization are also undergoing development. (author)

  12. First catalog of strong lens candidates in the COSMOS field

    CERN Document Server

    Faure, Cecile; Covone, Giovanni; Tasca, Lidia; Leauthaud, Alexie; Capak, Peter; Jahnke, Knud; Smolcic, Vernesa; de la Torre, Sylvain; Ellis, Richard; Finoguenov, Alexis; Heymans, Catherine; Koekemoer, Anton; Le Fevre, Olivier; Massey, Richard; Mellier, Yannick; Refregier, Alexandre; Rhodes, Jason; Scoville, Nick; Schinnerer, Eva; Taylor, James; Van Waerbeke, Ludovic; Walcher, Jakob

    2008-01-01

    We present the first catalog of 67 strong galaxy-galaxy lens candidates discovered in the 1.64 square degree Hubble Space Telescope COSMOS survey. Twenty of these systems display multiple images or strongly curved large arcs. Our initial search is performed by visual inspection of the data and is restricted, for practical considerations, to massive early-type lens galaxies with arcs found at radii smaller than ~5''. Simple mass models are constructed for the best lens candidates and our results are compared to the strong lensing catalogs of the SLACS survey and the CASTLES database. These new strong galaxy-galaxy lensing systems constitute a valuable sample to study the mass distribution of early-type galaxies and their associated dark matter halos. We further expect this sample to play an important role in the testing of software algorithms designed to automatically search for strong gravitational lenses. From our analysis a robust lower limit is derived for the expected occurrence of strong galaxy-galaxy sy...

  13. Chitah: Strong-gravitational-lens hunter in imaging surveys

    CERN Document Server

    Chan, James H H; Chiueh, Tzihong; More, Anupreeta; Marshall, Philip J; Coupon, Jean; Oguri, Masamune; Price, Paul

    2014-01-01

    Strong gravitationally lensed quasars provide powerful means to study galaxy evolution and cosmology. Current and upcoming imaging surveys will contain thousands of new lensed quasars, augmenting the existing sample by at least two orders of magnitudes. To find such lens systems, we built a robot, Chitah, that hunts for lensed quasars by modeling the configuration of the multiple quasar images. Specifically, given an image of an object that might be a lensed quasar, Chitah first disentangles the light from the supposed lens galaxy and the light from the multiple quasar images based on color information. A simple rule is designed to categorize the given object into a potential four-image (quad) or two-image (double) lensed quasar system. The configuration of the identified quasar images is subsequently modeled to classify whether the object is a lensed quasar system. We test the performance of Chitah using simulated lens systems based on the Canada-France-Hawaii-Telescope Legacy Survey. For bright quads with l...

  14. Twenty Meter Space Telescope Based on Diffractive Fresnel Lens

    Energy Technology Data Exchange (ETDEWEB)

    Early, J; Hyde, R; Baron, R

    2003-06-26

    Diffractive lenses offer two potential advantages for very large aperture space telescopes; very loose surface-figure tolerances and physical implementation as thin, flat optical elements. In order to actually realize these advantages one must be able to build large diffractive lenses with adequate optical precision and also to compactly stow the lens for launch and then fully deploy it in space. We will discuss the recent fabrication and assembly demonstration of a 5m glass diffractive Fresnel lens at LLNL. Optical performance data from smaller full telescopes with diffractive lens and corrective optics show diffraction limited performance with broad bandwidths. A systems design for a 20m space telescope will be presented. The primary optic can be rolled to fit inside of the standard fairings of the Delta IV vehicle. This configuration has a simple deployment and requires no orbital assembly. A twenty meter visible telescope could have a significant impact in conventional astronomy with eight times the resolution of Hubble and over sixty times the light gathering capacity. If the light scattering is made acceptable, this telescope could also be used in the search for terrestrial planets.

  15. Adaptive Semi-linear Inversion of Strong Gravitational Lens Imaging

    CERN Document Server

    Nightingale, James

    2014-01-01

    We present a new pixelized method for the inversion of gravitationally lensed extended source images which we term adaptive semi-linear inversion (SLI). At the heart of the method is an h-means clustering algorithm which is used to derive a source plane pixelization that adapts to the lens model magnification. The distinguishing feature of adaptive SLI is that every pixelization is derived from a random initialization, ensuring that data discretization is performed in a completely different and unique way for every lens model parameter set. We compare standard SLI on a fixed source pixel grid with the new method and demonstrate the shortcomings of the former when modeling singular power law ellipsoid (SPLE) lens profiles. In particular, we demonstrate the superior reliability and efficiency of adaptive SLI which, by design, fixes the number of degrees of freedom (NDOF) of the optimization and thereby removes biases present with other methods that allow the NDOF to vary. In addition, we highlight the importanc...

  16. Alignment and Testing of a Telecentric Zoom Lens Used for the Cygnus X-ray Source

    Energy Technology Data Exchange (ETDEWEB)

    Malone, R. M. [NSTec; Baker, S. A. [NSTec; Brown, K. K. [NSTec; Castaneda, J. J. [NSTec; Curtis, A. H. [NSTec; Danielson, J. [NSTec; Droemer, D. W. [NSTec; Esquibel, D. L. [NSTec; Haines, T. J. [LANL; Hollabaugh, J. S. [NSTec; Howe, R. A. [NSTec; Huerta, J. A. [NSTec; King, N. S. P. [LANL; Lutz, S. S. [NSTec; Kaufman, M. I. [NSTec; McGillivray, K. D. [NSTec; Smith, A. D. [NSTec; Stokes, B. M. [NSTec; Tibbitts, A. [NSTec

    2013-09-01

    Cygnus is a high-energy radiographic x-ray source. Three large zoom lenses have been assembled to collect images from large scintillators. A large elliptical pellicle (394 × 280 mm) deflects the scintillator light out of the x-ray path into an eleven-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of objects of different sizes, the scintillator and zoom lens are translated along the x-ray axis, and the zoom lens magnification changes. Zoom magnification is also changed when different-sized recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one doublet and allowing all other lenses to be repositioned, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 540 nm (for future operations). All lenses have an anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, the scintillator, and the CCD camera move during zoom operations. One doublet has x-y compensation. Alignment of the optical elements was accomplished using counter propagating laser beams and monitoring the retro-reflections and steering collections of laser spots. Each zoom lens uses 60 lb of glass inside the 425 lb mechanical structure, and can be used in either vertical or horizontal orientation.

  17. Intraocular lens power calculation after corneal refractive surgery using serf-designed computer software programmed with optimized calculation method%应用优化计算方法与计算机软件计算角膜屈光手术后人工晶状体屈光力

    Institute of Scientific and Technical Information of China (English)

    郭海科; 金海鹰; Gerd.U.AUFFARTH; 张洪洋

    2010-01-01

    目的 对准分子激光角膜屈光手术后人工晶状体屈光力的计算方法进行优化,并开发为计算机软件,评价其准确性与可靠性.方法 对人工晶状体屈光力计算方法进行优化,包括:角膜屈光力的矫正计算;人工晶状体有效位置的计算与双K值法(double-K method)的应用;标准化计算公式的应用.将计算方法编写为计算机应用软件(IOL calculator for post-refractive cases).应用该软件对49例角膜屈光手术后的白内障患者的人工晶状体屈光力进行计算,以白内障手术后实际屈光状态为标准,预测屈光状态与实际屈光状态之间的差异为预测误差,预测误差的绝对值为绝对预测误差.以SPSS 11.0软件分析预测误差与绝对预测误差的平均值与分布.结果 白内障手术后屈光状态为-2.50~0.75 D,平均为(-0.78±o.83)D,3眼(6.1%)为正视,36眼(73.5%)为近视,10眼(20.4%)为远视.预测误差为-1.26~1.96 D,平均(-0.02±0.75)D,接近于正视性屈光状态.绝对预测误差为0~1.96 D,平均(0.62±0.42)D,绝对预测误差≤0.5 D者19眼(38.8%),>0.5 D且≤1.0 D者22眼(44.9%),>1.0 D且≤1.5 D者7眼(14.3%),>1.5 D 且≤2.0 D者1眼(2.0%).结论 通过优化计算方法与开发计算机软件,可以充分简化准分子激光角膜屈光手术后人工晶状体屈光力的计算过程,并提高计算的准确性与可靠性.%Objective To evaluate intraocular lens power calculation after laser refractive surgery using an optimized calculation method and self-designed computer software. Methods Intraocular lens power calculation method was optimized in the following aspects: corrective algorithm for corneal power estimation; algorithm for effective lens position estimation and double-K method for intraocular lens power calculation; and standardized formula for intraocular lens power calculation.The calculation method was programmed into self-designed computer software (IOL calculator for post

  18. Restoring lens capsule integrity enhances lens regeneration in New Zealand albino rabbits and cats.

    Science.gov (United States)

    Gwon, A; Gruber, L J; Mantras, C

    1993-11-01

    In studies conducted by numerous investigators for 150 years, lenses regenerated following endocapsular lens extraction in New Zealand albino rabbits have been irregular in shape, appearing primarily doughnut-shaped as a result of lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. In the present study, we restored the lens capsule integrity by inserting a collagen patch at the time of surgery to seal the anterior capsulotomy and to improve the shape and structure of the regenerated lenses. We then filled the capsule bag with air to prevent adhesions between the anterior and posterior capsule and maintain capsule tautness and shape. Lens regeneration was first noted as early as one to two weeks. Regenerated lens filled approximately 50% of the capsule bag at two weeks and 100% by five weeks. Subsequent growth was in the anterior-posterior direction and measured by A-scan biometry. Lens thickness increased by 0.3 mm per month. The regenerated lenses were spherical with normal cortical structure and a nuclear opacity. In conclusion, restoration of lens capsular integrity with a collagen patch following endocapsular lens extraction enhanced the shape, structure, and growth rate of the regenerated lenses. In addition, lens regeneration was shown to occur in two cats.

  19. Conjunctival Microbiome Changes Associated With Soft Contact Lens and Orthokeratology Lens Wearing.

    Science.gov (United States)

    Zhang, Haikun; Zhao, Fuxin; Hutchinson, Diane S; Sun, Wenfeng; Ajami, Nadim J; Lai, Shujuan; Wong, Matthew C; Petrosino, Joseph F; Fang, Jianhuo; Jiang, Jun; Chen, Wei; Reinach, Peter S; Qu, Jia; Zeng, Changqing; Zhang, Dake; Zhou, Xiangtian

    2017-01-01

    Usage of different types of contact lenses is associated with increased risk of sight-threatening complications. Changes in the ocular microbiome caused by contact lens wear are suggested to affect infection development in those individuals. To address this question, this study compares conjunctival microbial communities in contact lens wearers with those in noncontact lens wearers. Paired-end sequencing of the V3 region of the 16S rRNA gene was used to characterize the bacterial communities on the conjunctival surfaces of contact lens wearers and nonwearers. No differences in microbial diversity were detected between contact lens wearers and nonwearers. Nevertheless, some slight microbe variability was evident between these two different groups. Bacillus, Tatumella and Lactobacillus abundance was less in orthokeratology lens (OKL) wearers than in nonwearers. In soft contact lenses (SCL) wearers, Delftia abundance decreased whereas Elizabethkingia levels increased. The difference in the SCL and nonwearer group was smaller than that in the OKL group. Variations in the conjunctival taxonomic composition between SCL wearers were larger than those in other groups. Sex differences in the conjunctival microbiota makeup were only evident among nonwearers. Even though there were slight percentage changes between contact lens wearers and nonwearers in some microbes, there were no differences in their diversity. On the other hand, contact lens usage might cause relative abundance of some taxa to change. Our results will help assess whether or not conjunctival microbiome changes caused by contact lens wear affect infection risk.

  20. The correction of electron lens aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, P.W., E-mail: peter.hawkes@cemes.fr

    2015-09-15

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. - Highlights: • Geometrical aberration correction. • Chromatic aberration correction. • 50 pm resolution. • High-resolution electron energy-loss spectroscopy. • Extensive bibliographies.

  1. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  2. Ensuring Safe Use of Contact Lens Solution

    Science.gov (United States)

    ... evaluating contact lens solutions and the development of Acanthamoeba keratitis, a rare but serious eye infection that's ... contact lenses to water has been associated with Acanthamoeba keratitis, a corneal infection that is resistant to ...

  3. PMMA-based ophthalmic contact lens for vision correction of strabismus

    Science.gov (United States)

    Asgharzadeh Shishavan, Amir; Nordin, Leland; Tjossem, Paul; Abramoff, Michael D.; Toor, Fatima

    2016-09-01

    In this work we present the design of a novel ophthalmic prismatic contact lens to correct for strabismus. Strabismus, colloquially called "crossed-eyes" or "wall eyes," is a condition in which the eyes are not properly aligned with each other. To our knowledge there are no contact lenses that allow for strabismus correction. To address this, we have designed a poly methyl methacrylate (PMMA) based prismatic correction contact lens. Therefore, we modeled a Fresnel lens with the appropriate optical properties and a human eye in COMSOL Multiphysics Ray Optics module. Our first design was created by mapping Fresnel lenses onto the curved surface of the eye, the focus of light on retina was suboptimal. Next we determined two more potential solutions and improved the light focus on the retina but there were still some issues. A small fraction of light ( 5%) diverged and could not be focused. Due to dispersive characteristic of PMMA, chromatic aberration was present. We will use our ray optics solution and convert into a metasurface nanophotonic lens that has the identical behavior and mitigates the issues related with prismatic lens.

  4. Flat-Base Broadband Multibeam Luneburg Lens for Wide Angle Scan

    CERN Document Server

    Jain, Sidharath

    2013-01-01

    In this paper we present the design of a flat-base Luneburg type of lens antenna, designed for wide angle scan. The antenna consists of a 11-layer lens, fed at its base by a 6x6 array of waveguides. The lens is broadband and has a high aperture efficiency, only 1 dB below that of a reference aperture antenna with uniform amplitude and phase distributions. Its sidelobe level is -21 dB at boresight and -13 dB when the scan angle is 64 degrees. It shows good performance when compared to the flat Luneburg lens previously reported in the literature, in terms of gain, scan capability, as well as ease of fabrication. It is shown to have the capability of producing multiple beams simultaneously, multiple angle, scan capability. Two different methodologies have been used to design the 6x6 feed array of waveguides for the lens. The first of these utilizes a conventional perfect electric conductor (PEC) waveguide, while the second employs materials for the guided wave region that have a high permittivity at frequencies ...

  5. Role of Aquaporin 0 in lens biomechanics.

    Science.gov (United States)

    Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

  6. Veselago lens by photonic hyper-crystals

    CERN Document Server

    Huang, Zun

    2014-01-01

    An imaging system functioning as a Veselago lens has been proposed based on the novel concept of photonic "hyper-crystal" -- an artificial optical medium synthesizing the properties of hyperbolic materials and photonic crystals. This Veselago lens shows a nearly constant negative refractive index and substantially reduced image aberrations. It can find potential applications in photolithography and hot-spots detection of silicon-based integrated circuits.

  7. In vivo human crystalline lens topography

    OpenAIRE

    Ortiz, Sergio; Pérez Merino, Pablo; Gambra, Enrique; Castro, Alberto; Marcos, Susana

    2012-01-01

    Custom high-resolution high-speed anterior segment spectral domain optical coherence tomography (OCT) was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo. The system was provided with custom algorithms for denoising and segmentation of the images, as well as for fan (scanning) and optical (refraction) distortion correction, to provide fully quantitative images of the anterior and posterior crystalline lens surfaces. The method was tested on an artificial eye ...

  8. Environmental standards for intraocular lens implantation.

    Science.gov (United States)

    Crawford, B A; Kaufman, D V

    1984-02-01

    Successful implantation of prosthetic devices depends upon their freedom from postoperative inflammation and infection. Techniques and lessons learned in orthopaedic and other implant surgery should be applied to intraocular lens implantation. The avoidance of contamination by particles and micro-organisms is one essential principle of the surgical procedure. Practical steps are described to reduce both types of contamination. These measures taken together are recommended for adoption as a standard of environmental safety for lens implantation.

  9. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    OpenAIRE

    Elena Bonafonte Marquez; Sergio Bonafonte Royo

    2015-01-01

    We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL) implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for i...

  10. Introduction to the development of intraocular lens

    Science.gov (United States)

    Li, Yifan; Peng, Runling; Hu, Shuilan; Wei, Maowei; Chen, Jiabi

    2013-08-01

    In order to cure the cataract disease or injuries in eyes, intraocular lens(IOL) has been studied all the time to replace the crystalline lens in human eyes. Researches on IOL are started early from 19th century, and it develops greatly in the hundreds years after. This article introduces several main kinds of IOLs that appear in the development history of IOL, and raises the double-liquid zoom IOL based on electrowetting, which will be the trend of IOL study.

  11. Evolution and the Calcite Eye Lens

    CERN Document Server

    Williams, Vernon L

    2013-01-01

    Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

  12. Multiocular image sensor with on-chip beam-splitter and inner meta-micro-lens for single-main-lens stereo camera.

    Science.gov (United States)

    Koyama, Shinzo; Onozawa, Kazutoshi; Tanaka, Keisuke; Saito, Shigeru; Kourkouss, Sahim Mohamed; Kato, Yoshihisa

    2016-08-01

    We developed multiocular 1/3-inch 2.75-μm-pixel-size 2.1M- pixel image sensors by co-design of both on-chip beam-splitter and 100-nm-width 800-nm-depth patterned inner meta-micro-lens for single-main-lens stereo camera systems. A camera with the multiocular image sensor can capture horizontally one-dimensional light filed by both the on-chip beam-splitter horizontally dividing ray according to incident angle, and the inner meta-micro-lens collecting the divided ray into pixel with small optical loss. Cross-talks between adjacent light field images of a fabricated binocular image sensor and of a quad-ocular image sensor are as low as 6% and 7% respectively. With the selection of two images from one-dimensional light filed images, a selective baseline for stereo vision is realized to view close objects with single-main-lens. In addition, by adding multiple light field images with different ratios, baseline distance can be tuned within an aperture of a main lens. We suggest the electrically selective or tunable baseline stereo vision to reduce 3D fatigue of viewers.

  13. New configuration of a lens for a 35-mm cinema projector.

    Science.gov (United States)

    Mittal, M K; Gupta, B N; Sharma, K D

    1990-06-01

    A new lens system configuration having seven uncemented elements made of Indian optical glasses has been developed. It has focal length of 75 mm, relative aperture of f/1.4 and is to be used in a 35-mm cinema projector objective. To compare the performance of this lens system, a commonly used design of seven uncemented elements based on double-Gauss configuration was also developed. The performance of the designs was evaluated by plotting aberration curves, energy distribution curves, and the geometrical MTF curves. The proposed new configuration gives better performance compared with the double-Gauss configuration being used currently.

  14. Lens Biology is a Dimension of Neurobiology.

    Science.gov (United States)

    Frederikse, Peter; Kasinathan, Chinnaswamy

    2017-02-04

    There is a second cell type in your body that expresses scores of the most intensively studied genes in neuroscience and exclusively shares critical interdependent modes of molecular regulation that include a network first described as responsible for the basic bifurcation of neuronal from non-neuronal gene expression in vertebrates. Neurons and lens cells are among the most ancient animal cell types, yet neurons have an exclusive status also attributed to roles underlying sensation, movement, and cognition. However, this status is challenged by cells in the lens of the eye. The extent and detail of internally consistent parallels with neuron biology now catalogued in their second native cell type in the lens provide a detailed model of interdependent neuron gene expression in lens development and non-neuronal role in vision. These comprehensive parallels identify the lens as a dimension of neurobiology and a fundamental new perspective on neurodevelopment and its disorders. Finally, this understanding identifies that hallmark neuronal gene expression and key modes of associated molecular regulation evolved in tandem in the lens.

  15. Conservation through the economics lens.

    Science.gov (United States)

    Farley, Joshua

    2010-01-01

    Although conservation is an inherently transdisciplinary issue, there is much to be gained from examining the problem through an economics lens. Three benefits of such an approach are laid out in this paper. First, many of the drivers of environmental degradation are economic in origin, and the better we understand them, the better we can conserve ecosystems by reducing degradation. Second, economics offers us a when-to-stop rule, which is equivalent to a when-to-conserve rule. All economic production is based on the transformation of raw materials provided by nature. As the economic system grows in physical size, it necessarily displaces and degrades ecosystems. The marginal benefits of economic growth are diminishing, and the marginal costs of ecological degradation are increasing. Conceptually, we should stop economic growth and focus on conservation when the two are equal. Third, economics can help us understand how to efficiently and justly allocate resources toward conservation, and this paper lays out some basic principles for doing so. Unfortunately, the field of economics is dominated by neoclassical economics, which builds an analytical framework based on questionable assumptions and takes an excessively disciplinary and formalistic approach. Conservation is a complex problem, and analysis from individual disciplinary lenses can make important contributions to conservation only when the resulting insights are synthesized into a coherent vision of the whole. Fortunately, there are a number of emerging transdisciplines, such as ecological economics and environmental management, that are dedicated to this task.

  16. Mini-scleral Contact Lens for Management of Poor Visual Outcomes after Intrastromal Corneal Ring Segments Implantation in Keratoconus

    Science.gov (United States)

    Alipour, Fatemeh; Rahimi, Firoozeh; Hashemian, Mohammad Naser; Ajdarkosh, Zahra; Roohipoor, Ramak; Mohebi, Masoumeh

    2016-01-01

    Purpose: To evaluate the feasibility and efficacy of mini-scleral design (MSD) contact lenses to treat keratoconus patients who were unsatisfied with the results of corneal inlay. Methods: In this prospective interventional case series, 9 eyes of 6 keratoconus patients who were unsatisfied with the results of corneal inlay were fitted with MSD contact lenses. Demographic data, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and higher order aberrations (HOAs) were evaluated before contact lens fitting. Corrected visual acuity by placing the MSD contact lens with or without over-refraction, and HOAs were measured one hour after contact lens fitting. One month after contact lens wearing, corrected visual acuity by placing the MSD contact lens with over-refraction and possible contact lens related problems were assessed. Ocular comfort and contact lens handling problems were asked in follow-up visits. The data was analyzed using descriptive statistical tests. Results: Nine eyes of 6 patients were successfully fitted with the mini-scleral lens. Fitting was ideal in 7 eyes and acceptable in 2 eyes. Mean corrected visual acuity by placing the MSD lens without over-refraction was 0.09 (range, 0.00-0.15) LogMAR which was significantly better than the mean BSCVA of 0.38 (range, 0.2-0.6) LogMAR (P = 0.007). The mean root mean square (RMS) of third-order coma and trefoil significantly decreased after MSD contact lens fitting (P = 0.012 and P = 0.015, respectively); however, changes in the fourth-order spherical aberration were not statistically significant (P = 0.336). Conclusion: Mini-scleral contact lenses may be helpful in the management of visually unsatisfied patients after corneal inlay. PMID:27621780

  17. Tethered capsule OCT endomicroscopy for upper gastrointestinal tract imaging by using ball lens probe (Conference Presentation)

    Science.gov (United States)

    Dong, Jing; Gora, Michalina J.; Reddy, Rohith; Trasischker, Wolfgang; Poupart, Oriane; Lu, Weina; Carruth, Robert W.; Grant, Catriona N.; Soomro, Amna R.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

    2016-03-01

    While endoscopy is the most commonly used modality for diagnosing upper GI tract disease, this procedure usually requires patient sedation that increases cost and mandates its operation in specialized settings. In addition, endoscopy only visualizes tissue superfically at the macroscopic scale, which is problematic for many diseases that manifest below the surface at a microscopic scale. Our lab has previously developed technology termed tethered capsule OCT endomicroscopy (TCE) to overcome these diagnostic limitations of endoscopy. The TCE device is a swallowable capsule that contains optomechanical components that circumferentially scan the OCT beam inside the body as the pill traverses the organ via peristalsis. While we have successfully imaged ~100 patients with the TCE device, the optics of our current device have many elements and are complex, comprising a glass ferrule, optical fiber, glass spacer, GRIN lens and prism. As we scale up manufacturing of this device for clinical translation, we must decrease the cost and improve the manufacturability of the capsule's optical configuration. In this abstract, we report on the design and development of simplificed TCE optics that replace the GRIN lens-based configuration with an angle-polished ball lens design. The new optics include a single mode optical fiber, a glass spacer and an angle polished ball lens, that are all fusion spliced together. The ball lens capsule has resolutions that are comparable with those of our previous GRIN lens configuration (30µm (lateral) × 7 µm (axial)). Results in human subjects show that OCT-based TCE using the ball lens not only provides rapid, high quality microstructural images of upper GI tract, but also makes it possible to implement this technology inexpensively and on a larger scale.

  18. Consumer electronic optics: how small can a lens be: the case of panomorph lenses

    Science.gov (United States)

    Thibault, Simon; Parent, Jocelyn; Zhang, Hu; Du, Xiaojun; Roulet, Patrice

    2014-09-01

    In 2014, miniature camera modules are applied to a variety of applications such as webcam, mobile phone, automotive, endoscope, tablets, portable computers and many other products. Mobile phone cameras are probably one of the most challenging parts due to the need for smaller and smaller total track length (TTL) and optimized embedded image processing algorithms. As the technology is developing, higher resolution and higher image quality, new capabilities are required to fulfil the market needs. Consequently, the lens system becomes more complex and requires more optical elements and/or new optical elements. What is the limit? How small an injection molded lens can be? We will discuss those questions by comparing two wide angle lenses for consumer electronic market. The first lens is a 6.56 mm (TTL) panoramic (180° FOV) lens built in 2012. The second is a more recent (2014) panoramic lens (180° FOV) with a TTL of 3.80 mm for mobile phone camera. Both optics are panomorph lenses used with megapixel sensors. Between 2012 and 2014, the development in design and plastic injection molding allowed a reduction of the TTL by more than 40%. This TTL reduction has been achieved by pushing the lens design to the extreme (edge/central air and material thicknesses as well as lens shape). This was also possible due to a better control of the injection molding process and material (low birefringence, haze and thermal stability). These aspects will be presented and discussed. During the next few years, we don't know if new material will come or new process but we will still need innovative people and industries to push again the limits.

  19. Early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: an economic evaluation based on data from the EAGLE trial

    Science.gov (United States)

    Javanbakht, Mehdi; Azuara-Blanco, Augusto; Burr, Jennifer M; Ramsay, Craig; Cooper, David; Cochran, Claire; Norrie, John; Scotland, Graham

    2017-01-01

    Objective To investigate the cost-effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma (PACG) compared to standard care. Design Cost-effectiveness analysis alongside a multicentre pragmatic two-arm randomised controlled trial. Patients were followed-up for 36 months, and data on health service usage and health state utility were collected and analysed within the trial time horizon. A Markov model was developed to extrapolate the results over a 5-year and 10-year time horizon. Setting 22 hospital eye services in the UK. Population Males and females aged 50 years or over with newly diagnosed PACG or primary angle closure (PAC). Interventions Lens extraction compared to standard care (ie, laser iridotomy followed by medical therapy and glaucoma surgery). Outcome measures Costs of primary and secondary healthcare usage (UK NHS perspective), quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER) for lens extraction versus standard care. Results The mean age of participants was 67.5 (8.42), 57.5% were women, 44.6% had both eyes eligible, 1.4% were of Asian ethnicity and 35.4% had PAC. The mean health service costs were higher in patients randomised to lens extraction: £2467 vs £1486. The mean adjusted QALYs were also higher with early lens extraction: 2.602 vs 2.533. The ICER for lens extraction versus standard care was £14 284 per QALY gained at three years. Modelling suggests that the ICER may drop to £7090 per QALY gained by 5 years and that lens extraction may be cost saving by 10 years. Our results are generally robust to changes in the key input parameters and assumptions. Conclusions We find that lens extraction has a 67–89% chance of being cost-effective at 3 years and that it may be cost saving by 10 years. Trial registration number ISRCTN44464607; Results. PMID:28087548

  20. Long-range visible light communication system based on LED collimating lens

    Science.gov (United States)

    Chen, Yingcong; Wen, Shangsheng; Wu, Yuxiang; Ren, Yuanyuan; Guan, Weipeng; Zhou, Yunlin

    2016-10-01

    An advanced visible light communication (VLC) system is proposed for long-range VLC, such as marine communication. The design of the system is conducted into two parts. Firstly, we design and optimize a collimating lens for the optical antenna by using Taguchi method. The lighting effects and optical power of the receiving end in different distances are simulated by TracePro software. Then, the long-range VLC channel is reconstructed by integrating the influence of the atmospheric attenuation and frequency response. The performance of the OOK coding VLC system is tested by Matlab software. The results show that: the emitting angle of the optimized collimating lens is 1.7°. By using 1 W LED and collimating lens as an optical antenna, the system can achieve a data rate of 210 Mbit/s at a bit error rate of 10-3 in 90 m.

  1. Electron Lens Construction for the Integrable Optics Test Accelerator at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    McGee, Mike [Fermilab; Carlson, Kermit [Fermilab; Nobrega, Lucy [Fermilab; Stancari, Giulio [Fermilab; Valishev, Alexander [Fermilab

    2016-06-01

    The Integrable Optics Test Accelerator (IOTA) is proposed for operation at Fermilab. The goal of IOTA is to create practical nonlinear accelerator focusing systems with a large frequency spread and stable particle motion. The IOTA is a 40 m circumference, 150 MeV (e-), 2.5 MeV (p⁺) diagnostic test ring. Construction of an electron lens for IOTA is necessary for both electron and proton operation. Components required for the Electron Lens design include; a 0.8 T conventional water-cooled main solenoid, and magnetic bending and focusing elements. The foundation of the design relies on repurposing the Fermilab Tevatron Electron Lens II (TELII) gun and collector under ultra-high vacuum (UHV) conditions.

  2. Freeform lens collimating spectrum-folded Hadamard transform near-infrared spectrometer

    Science.gov (United States)

    Wang, Xiaoduo; Liu, Hua; Juschkin, Larissa; Li, Yunpeng; Xu, Jialin; Quan, Xiangqian; Lu, Zhenwu

    2016-12-01

    A novel Hadamard transform spectrometer collimated by a freeform lens has been designed, which doubles the working spectral range while the spectral resolution is maintained. The freeform lens is designed to redistribute the broadband spectra of the source from 800 nm to 2400 nm into two collimated beams with different wavelengths and different tilting angles, to achieve the folding of spectra on the digital micro-mirror devices (DMD). It is constructed by solving two partial differential equations. The grating diffraction efficiency of the two split beams are more uniform and higher compared with the traditional method. The simulation results show that the bandwidth of the spectrometer is doubled and the spectral resolution is better than 10 nm. The optical system becomes more compact, and the energy efficiency is improved by 11.98% by folding the spectra with one freeform lens and one grating.

  3. A slide rule for calculating the ocular accommodation of an ametrope corrected with a spectacle lens.

    Science.gov (United States)

    Wang, Guang-Ji

    2007-07-01

    A slide rule has been designed to calculate the ocular accommodation of an ametrope corrected with a spectacle lens. The slide rule makes the calculation itself easier to perform than with traditional methods and is easily applicable in a clinical setting. In the slide rule, there are 3 scales indicating the power of the spectacle lens, the viewing distance, and the ocular accommodation. The most accurate accommodative unit was used to design the slide rule. The ocular accommodation is the product of the accommodative unit and the dioptric viewing distance. The calculating results are accurate from +21 diopters to all minus powers of the spectacle lens. In a clinical setting, the patients can be advised how much accommodation they exert before and after the refractive surgeries.

  4. The Sloan Lens ACS Survey. V. The full ACS strong-lens sample

    NARCIS (Netherlands)

    Bolton, Adam S.; Burles, Scott; Koopmans, Leon V. E.; Treu, Tommaso; Gavazzi, Raphael; Moustakas, Leonidas A.; Wayth, Randall; Schlegel, David J.

    2008-01-01

    We present the definitive data for the full sample of 131 strong gravitational lens candidates observed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope by the Sloan Lens ACS (SLACS) Survey. All targets were selected for higher redshift emission lines and lower redshift

  5. Effect of infusion bottle height on lens power after lens refilling with and without a plug

    NARCIS (Netherlands)

    Koopmans, SA; Terwee, T; Haitjema, HJ; Kooijman, AC; Barkhof, J

    2003-01-01

    Purpose: To evaluate the influence of intraoperative infusion bottle height on the power of refilled pig lenses. Setting: Research Laboratory, Pharmacia Intraocular Lens Manufacturing Plant, Groningen, The Netherlands. Methods: This study comprised 2 groups of pig eyes. In 1 group, the lens was refi

  6. Gravitational binary-lens events with prominent effects of lens orbital motion

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.; Han, C.; Choi, J.-Y. [Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Kubiak, M.; Soszyński, I.; Pietrzyński, G.; Poleski, R.; Ulaczyk, K.; Pietrukowicz, P.; Kozłowski, S.; Skowron, J.; Wyrzykowski, Ł. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, A.; Gaudi, B. S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Beaulieu, J.-P. [Institut d' Astrophysique de Paris, UMR 7095 CNRS-Université Pierre and Marie Curie, 98bis Bd Arago, F-75014 Paris (France); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Depoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Dong, Subo [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Collaboration: OGLE Collaboration; μFUN Collaboration; PLANET Collaboration; RoboNet Collaboration; and others

    2013-12-01

    Gravitational microlensing events produced by lenses composed of binary masses are important because they provide a major channel for determining physical parameters of lenses. In this work, we analyze the light curves of two binary-lens events, OGLE-2006-BLG-277 and OGLE-2012-BLG-0031, for which the light curves exhibit strong deviations from standard models. From modeling considering various second-order effects, we find that the deviations are mostly explained by the effect of the lens orbital motion. We also find that lens parallax effects can mimic orbital effects to some extent. This implies that modeling light curves of binary-lens events not considering orbital effects can result in lens parallaxes that are substantially different from actual values and thus wrong determinations of physical lens parameters. This demonstrates the importance of routine consideration of orbital effects in interpreting light curves of binary-lens events. It is found that the lens of OGLE-2006-BLG-277 is a binary composed of a low-mass star and a brown dwarf companion.

  7. The Sloan Lens ACS Survey. V. The full ACS strong-lens sample

    NARCIS (Netherlands)

    Bolton, Adam S.; Burles, Scott; Koopmans, Leon V. E.; Treu, Tommaso; Gavazzi, Raphael; Moustakas, Leonidas A.; Wayth, Randall; Schlegel, David J.

    2008-01-01

    We present the definitive data for the full sample of 131 strong gravitational lens candidates observed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope by the Sloan Lens ACS (SLACS) Survey. All targets were selected for higher redshift emission lines and lower redshift c

  8. DISSECTING THE GRAVITATIONAL LENS B1608+656. I. LENS POTENTIAL RECONSTRUCTION

    NARCIS (Netherlands)

    Suyu, S. H.; Marshall, P. J.; Blandford, R. D.; Fassnacht, C. D.; Koopmans, L. V. E.; McKean, J. P.; Treu, T.

    2009-01-01

    Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential ( m

  9. Common path ball lens probe for optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Singh, Kanwarpal; Yamada, Daisuke; Tearney, Guillermo J.

    2016-02-01

    Background: Common path probes are highly desirable for optical coherence tomography (OCT) as they reduce system complexity and cost. In this work we report an all-fiber common path side viewing monolithic probe for coronary artery imaging. Methods: Our common path probe was designed for spectrometer based Fourier domain OCT at 1310 nm wavelength. Light from the fiber expands in the coreless fiber region and then focussed by the ball lens. Reflection from ball lens-air interface served as reference signal. The monolithic ball lens probe was assembled within a 560 µmouter diameter drive shaft which was attached to a rotary junction. The drive shaft was placed inside an outer, transparent sheath of 800 µm diameter. Results: With a source input power of 25 mW, we could achieve sensitivity of 100.5 dB. The axial resolution of the system was found to be 15.6 µm in air and the lateral resolution (full width half maximum) was approximately 49 µm. As proof of principal, images of skin acquired using this probe demonstrated clear visualization of the stratum corneum, epidermis, and papillary dermis, along with sweat ducts. Conclusion: In this work we have demonstrated a monolithic, ball lens common, path probe for OCT imaging. The designed ball lens probe is easy to fabricate using a laser splicer. Based on the features and capability of common path probes to provide a simpler solution for OCT, we believe that this development will be an important enhancement for certain types of catheters.

  10. Electrically tunable micro-lens with a strain-enhanced polymer nanocomposite actuator (Conference Presentation)

    Science.gov (United States)

    Costache, Florenta A.; Pawlik, Boscij; Rieck, Andreas

    2017-02-01

    A fluid-filled micro-lens concept with an electrically driven polymer actuator was developed in view of optimization of its variation in focal length. The high strain electrostrictive terpolymer P(VDF-TrFE-CFE) was first used in the actuator design for this purpose. Our study showed that the electric field-induced strain in polymer thin films could be even further enhanced by mixing high-k BaTiO3 nanoparticles in the terpolymer. A newly developed nanocomposite P(VDF-TrFE-CFE) / BaTiO3 ring-shaped actuator was implemented into the 3 mm aperture, liquid-filled micro-lens concept. The micro-lens was fabricated in a wafer-level process flow, which included micromachining of fluidic chambers on silicon wafers, thin film nanocomposite actuator processing, assembly through wafer bonding and chip filling with liquids. Particular characteristics of the nanocomposite were taken into account such as the homogeneous nanoparticle dispersion into the thin film with impact on thin film dielectric breakdown, electrode adherence as well as nanocomposite film etching. Variable focal length micro-lenses conceps with a single fluidic chamber but also with two fluidic chambers (a design, which can potentially improve the lens membrane stability) were fabricated and characterized. We could demonstrate a wide focal length variation of tens of diopters first for a single chamber plano-convex micro-lens obtained by adjusting the voltage applied on the integrated actuator.

  11. Reducing aberration effect of Fourier transform lens by modifying Fourier spectrum of diffractive optical element in beam shaping optical system.

    Science.gov (United States)

    Zhang, Fang; Zhu, Jing; Song, Qiang; Yue, Weirui; Liu, Jingdan; Wang, Jian; Situ, Guohai; Huang, Huijie

    2015-10-20

    In general, Fourier transform lenses are considered as ideal in the design algorithms of diffractive optical elements (DOEs). However, the inherent aberrations of a real Fourier transform lens disturb the far field pattern. The difference between the generated pattern and the expected design will impact the system performance. Therefore, a method for modifying the Fourier spectrum of DOEs without introducing other optical elements to reduce the aberration effect of the Fourier transform lens is proposed. By applying this method, beam shaping performance is improved markedly for the optical system with a real Fourier transform lens. The experiments carried out with a commercial Fourier transform lens give evidence for this method. The method is capable of reducing the system complexity as well as improving its performance.

  12. An improved spinning lens test to determine the stiffness of the human lens

    Science.gov (United States)

    Burd, H.J.; Wilde, G.S.; Judge, S.J.

    2011-01-01

    It is widely accepted that age-related changes in lens stiffness are significant for the development of presbyopia. However, precise details on the relative importance of age-related changes in the stiffness of the lens, in comparison with other potential mechanisms for the development of presbyopia, have not yet been established. One contributing factor to this uncertainty is the paucity and variability of experimental data on lens stiffness. The available published data generally indicate that stiffness varies spatially within the lens and that stiffness parameters tend to increase with age. However, considerable differences exist between these published data sets, both qualitatively and quantitatively. The current paper describes new and improved methods, based on the spinning lens approach pioneered by Fisher, R.F. (1971) ‘The elastic constants of the human lens’, Journal of Physiology, 212, 147–180, to make measurements on the stiffness of the human lens. These new procedures have been developed in an attempt to eliminate, or at least substantially reduce, various systematic errors in Fisher’s original experiment. An improved test rig has been constructed and a new modelling procedure for determining lens stiffness parameters from observations made during the test has been devised. The experiment involves mounting a human lens on a vertical rotor so that the lens spins on its optical axis (typically at 1000 rpm). An automatic imaging system is used to capture the outline of the lens, while it is rotating, at pre-determined angular orientations. These images are used to quantify the deformations developed in the lens as a consequence of the centripetal forces induced by the rotation. Lens stiffness is inferred using axisymmetric finite element inverse analysis in which a nearly-incompressible neo-Hookean constitutive model is used to represent the mechanics of the lens. A numerical optimisation procedure is used to determine the stiffness parameters

  13. Corneal topography and soft contact lens fit.

    Science.gov (United States)

    Young, Graeme; Schnider, Cristina; Hunt, Chris; Efron, Suzanne

    2010-05-01

    To determine which ocular topography variables affect soft contact lens fit. Fifty subjects each wore three pairs of soft lenses in random succession (Vistakon Acuvue 2, Vistakon Acuvue Advance, Ciba Vision Night & Day), and various aspects of lens fit were evaluated. The steeper base curves of each type were worn in one eye and the flatter base curves in the other eye. Corneal topography data were collected using a Medmont E300 corneal topographer (Camberwell, Australia). Corneal curvature, shape factor (SF), and corneal height were measured over a 10 mm chord and also over the maximum measurable diameter. These were measured in the horizontal, vertical, steepest, and flattest meridians. With each lens type, the steeper base curve provided the best fit on the greatest proportion of eyes and the significant differences in various aspects of fit were noted between base curves. For each lens type, there was no significant difference in mean K-reading between those eyes best fit with the steeper base curve and those eyes best fit with the flatter base curve. Two of the lenses showed a positive correlation between centration and horizontal corneal height (maximum), whereas one lens showed a negative correlation between centration and horizontal SF (SF = e). Several lenses showed a positive correlation between post-blink movement and horizontal or vertical corneal SF. The measurement of corneal topography using current Placido disc instrumentation allows a better prediction of soft lens fit than by keratometry, but it is not reliable enough to enable accurate selection of the best fitting base curve. Some correlations are evident between corneal measurements; however, trial fitting remains the method of choice for selection of soft lens base curve.

  14. Preliminary 3D In-situ measurements of the texture evolution of strained H2O ice during annealing using neutron Laue diffractometry

    Science.gov (United States)

    Journaux, Baptiste; Montagnat, Maurine; Chauve, Thomas; Ouladdiaf, Bachir; Allibon, John

    2015-04-01

    Dynamic recrystallization (DRX) strongly affects the evolution of microstructure (grain size and shape) and texture (crystal preferred orientation) in materials during deformation at high temperature. Since texturing leads to anisotropic physical properties, predicting the effect of DRX is essential for industrial applications, for interpreting geophysical data and modeling geodynamic flows, and predicting ice sheet flow and climate evolution. A large amount of literature is available related to metallurgy, geology or glaciology, but there remains overall fundamental questions about the relationship between nucleation, grain boundary migration and texture development at the microscopic scale. Previous measurements of DRX in ice were either conducted using 2D ex-situ techniques such as AITA [1,2] or Electron Backscattering Diffraction (EBSD) [3], or using 3D statistical ex-situ [4] or in-situ [5] techniques. Nevertheless, all these techniques failed to observe at the scale of nucleation processes during DRX in full 3D. Here we present a new approach using neutron Laue diffraction, which enable to perform 3D measurements of in-situ texture evolution of strained polycrystalline H2O ice (>2% at 266 K) during annealing at the microscopic scale. Thanks the CYCLOPS instrument [6] (Institut Laue Langevin Grenoble, France) and the intrinsic low background of this setup, preliminary observations enabled us to follow, in H2O ice, the evolution of serrated grain boundaries, and kink-band during annealing. Our observations show a significant evolution of the texture and internal misorientation over the course of few hours at an annealing temperature of 268.5 K. In the contrary, ice kink-band structures seem to be very stable over time at near melting temperatures. The same samples have been analyzed ex-situ using EBSD for comparison. These results represent a first step toward in-situ microscopic measurements of dynamic recrystallization processes in ice during strain. This

  15. [Representation and mathematical analysis of human crystalline lens].

    Science.gov (United States)

    Tălu, Stefan; Giovanzana, Stefano; Tălu, Mihai

    2011-01-01

    The surface of human crystalline lens can be described and analyzed using mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the lens. The mathematical models used in lens biomechanics allow the study and the behavior of crystalline lens on variables and complex dynamic loads. Also, the lens biomechanics has the potential to improve the results in the development of intraocular lenses and cataract surgery. The paper presents the most representative mathematical models currently used for the modeling of human crystalline lens, both optically and biomechanically.

  16. Imaging characteristics of a volume holographic lens

    Science.gov (United States)

    Yang, Jing; Jiang, Zhu-qing; Xu, Zhi-qiang; Liu, Shao-jie; Sun, Ya-jun; Tao, Shi-quan

    2009-07-01

    A volume holographic grating lens can reconstruct the three-dimensional information by conducting multiple optical slicing of an object based on Bragg selectivity of the volume holographic grating. In this paper, we employ the point-spread function of volume holographic imaging system to theoretically analyze its imaging resolution. In the experiments, the volume holographic gratings are made with a spherical reference (SR) and a planar reference (PR), respectively, and used as volume holographic imaging lens in our imaging system. The longitudinal and lateral defocusing characteristics of volume holographic lens with SR and with PR are investigated experimentally by displacing the interested objects from original reference location, respectively. The effects of the parameters of the volume holographic lens on the longitudinal and lateral resolution are also discussed. The experimental results show that increasing the size of the volume holographic lens can improve the depth resolution, and in particular, it has greater influence on SR VHI. The lateral selectivity of SR VHI is more sensitive than that of PR VHI, and the Bragg degenerate diffraction of PR VHI on the y axis is obviously observed.

  17. Complementary safety assessment in the light of the Fukushima accident - Laue Langevin Institute; Evaluation complementaire de la surete au regard de l'accident de Fukushima - Institut Laue Langevin

    Energy Technology Data Exchange (ETDEWEB)

    Desbriere; Caillot; Bidet [ILL, 6 rue Jules Horowitz, 38042 Grenoble cedex 9 (France)

    2012-03-08

    This CSA (Complementary Safety Assessment) analyses the robustness of the Grenoble High Flux reactor to extreme situations such as those that led to the Fukushima accident and proposes a series of improvements. Robustness is the ability for the facility to withstand events beyond the level for which the facility was designed. Robustness is linked to safety margins but also to the situations leading to a sudden deterioration of the accident sequence (cliff edge effect). Safety is not only a matter of design or of engineered systems, it is also a matter of organization. So issues like crisis organization and work organization via subcontracting are also taken into consideration. This report is divided into 9 main chapters: 1) main features of the high flux reactor, 2) macroscopic study of safety, identification of structures and equipment essential to safety, 3) earthquake risk, 4) flood risk, 5) risks due to other extreme natural disasters, 6) the loss of electrical power supplies and of cooling systems, 7) management of severe accidents, 8) subcontracting policy, 9) synthesis and improvements. This study confirms the robustness of the facility and a series of improvements and modifications is proposed to face very unlikely situations (especially plurality of failures) that were not taken into account in baseline safety studies. (A.C.)

  18. 对数螺旋型劳厄弯晶的X射线单色成像应用%Logarithmic Spiral Bent Laue Crystals for X-Ray Monochromatic Imaging Applications

    Institute of Scientific and Technical Information of China (English)

    毋玉芬; 肖沙里; 鲁建; 钱家渝; 刘利锋; 黄显宾

    2013-01-01

    Taking advantages of the monochromatic X-ray diffraction property of Laue crystals,an innovative use of logarithmic spiral bent Laue crystals for X-ray monochromatic imaging is investigated.According to the ray tracing method and the surface equation of the logarithmic spiral,the imaging principles and characteristics of the logarithmic spiral bent Laue crystals are studied,including the condition that the diffracted beam can be separated from the transmitted beam,the magnifications and the field of view (FOV).A logarithmic spiral bent quartz (1010) Laue crystal analyzer is developed.With the proposed crystal analyzer,the monochromatic backlight imaging experiment for the mesh grid with a diameter of 50 μm is carried out by taking an X-ray source of Cu target as the backlighter.The experimental results show that the spatial resolution of the analyzer is approximately 11.9 μm under a source diameter of 110 μm.Furthermore,the FOVs of the crystal analyzer are 22.3557 mm and 8.2602 mm in horizontal and vertical directions,respectively.%利用劳厄晶体研究了X射线的单色衍射性质,研究了对数螺旋型劳厄弯晶在等离子体X射线单色成像中的应用.根据光线追迹原理及对数螺旋线的表面方程,研究了对数螺旋型劳厄弯晶的单色成像原理,分析了单色衍射像不受透射白光X射线影响的准则,以及子午、弧矢放大倍数和单色成像视场等性能参数.研制了石英晶体(1010)对数螺旋劳厄弯晶分析器,以铜靶X射线源作为背光源,对网丝直径为50 μm的金属网格进行了单色背光成像实验.实验结果表明,当背光源尺寸为110 μm时,对数螺旋型劳厄弯晶的空间分辨力约为11.9μm,分析器在子午和弧矢方向的视场分别达到22.3557 mm和8.2602 mm.

  19. Apoptosis in the lens anlage of the heritable lens aplastic mouse (lap mouse).

    Science.gov (United States)

    Aso, S; Tashiro, M; Baba, R; Sawaki, M; Noda, S; Fujita, M

    1998-08-01

    Adult homozygous lap mice show various eye abnormalities, such as aphakia, retinal disorganization, and dysplasia of the cornea and anterior chamber. In the fetal eye of a homozygous lap mouse, the lens placode seems to develop normally. However, the lens vesicle progresses abnormally to form a mass of cells without a cavity, and the mass vanishes soon afterward. We examined cell death in the lens anlage of this mutant. The lens anlagen of homozygous lap and normal mice from days 10 to 12 of gestation were observed by light microscopy after DNA end-labeling by immunohistochemistry and by transmission electron microscopy. By light microscopy, a slight frequency of cell death was detected in the lens anlage encircling the surface ectoderm and in the anlage or in the anlage of both homozygous lap mice and normal mice at day 10 of gestation. Cell death was seen in the lens anlage encircling the surface ectoderm in the normal mouse and sporadically in the anlage of the homozygous lap mouse at day 10.5 of gestation. Cell death was visible at the area of the lens vesicle attached to the surface ectoderm and encircling the surrounding surface ectoderm in the normal mouse, and in the lens anlage encircling the surface ectoderm and the apex areas of the lens anlage in the homozygous lap mouse at day 11 of gestation. At day 12 of gestation, almost no cell death was observed in the lens anlage of the normal mouse. However, extensive areas of cell death were still seen in the lens anlage at its apex, at the inner region, and encircling the surface ectoderm in the homozygous lap mouse. Electron microscopic observation showed that the dead cells observed in the lens anlagen by light microscopy in normal and lap mice are the result of apoptosis. In lap mice, cells with cytoplasmic condensation were observed mainly at days 10 and 10.5 of gestation. Many apoptotic bodies which had been phagocytosed by adjacent cells were seen predominantly at day 11 of gestation. At day 12 of

  20. Water soluble drug releasing soft contact lens in response to pH of tears

    Science.gov (United States)

    Kim, G.; Noh, H.

    2016-06-01

    Human tear characteristics including pH and compositions can vary significantly depending on physical and environmental factors. Contact lenses directly contact with human tears can be swelled or de-swelled depending on the pH of the solution due to the nature of the hydrogel. For examples, anionic hydrogels, when the solution's pH is low, is shrunken due to the electric attraction force within the hydrogel network; the opposite phenomenon appears when the solution is basic. The purpose of this study was to evaluate the extent of water soluble drug, hydroxyl propyl methyl cellulose, released from contact lens according to the pH of the artificial tears. Artificial tears are prepared by mixing lysozyme, albumin, sodium chloride, potassium chloride, and calcium chloride following physiological concentrations. Hydrogel contact lens was thermally polymerized using HEMA, EGDMA, and AIBN. The prepared hydrogel lens was immersed in drug for 3 hours and the eluted drug mass was measured as a function of the time. As a result, the drug was released from the lens for 12 hours in all the pH of artificial tears. At the lower pH of artificial tears (pH 5.8), the total amount of dye emitted from the lens was increased than the total amount of dye emitted at the basic tear (pH 8.4). Also, initial burst at acidic tears was increased within 1 hour. Release pattern of water-soluble drug from hydrogel lens turned out to be different depending on the pH of the artificial tears. When designing drug releasing contact lens, physiological pH of tears should be considered.