WorldWideScience

Sample records for non-linear electro-optic materials

  1. Passive electro optical materials and applications

    Science.gov (United States)

    Diekstall, K.; Gutu-Nelle, A.; Lauckner, J.; Lutz, F.; Mueller, S.; Seibold, G.; Schichl, H.; Volz, H.

    1980-12-01

    Electro-optical ceramics made of lead/lanthanum/zirconates/titanates (PLZT) can be economically manufactured by coprecipitation of the base materials and by vacuum sintering of the sintering of the green blocks. Magnesium additives reduce by half the operating voltage required to achieve an equal contrast ratio. Transparent electrodes deposited by sputtering tin-indium oxide remain transparent up to 2400 nm. The contrast ratio in the scattering mode amounts typically to 100 : 1 at 500 nm and 5 : 1 at 1000 nm, while in the birefrigence mode it amounts typically to 10,000 : 1 at 800 V/mm, at a thickness of 0.4 mm. Functional blocks were designed to demonstrate and test applications: a laser modular; a light intensity attenuator; welding protection goggles; and numerical displays. The first promising results with sputtered thin films indicate future suitability for displays. Multiple light modulators for opto-electronic nonimpact printing presently appear to be the most important application area.

  2. Rational design of organic electro-optic materials

    CERN Document Server

    Dalton, L R

    2003-01-01

    Quantum mechanical calculations are used to optimize the molecular first hyperpolarizability of organic chromophores and statistical mechanical calculations are used to optimize the translation of molecular hyperpolarizability to macroscopic electro-optic activity (to values of greater than 100 pm V sup - sup 1 at telecommunications wavelengths). Macroscopic material architectures are implemented exploiting new concepts in nanoscale architectural engineering. Multi-chromophore-containing dendrimers and dendronized polymers not only permit optimization of electro-optic activity but also of auxiliary properties including optical loss (both absorption and scattering), thermal and photochemical stability and processability. New reactive ion etching and photolithographic techniques permit the fabrication of three-dimensional optical circuitry and the integration of that circuitry with semiconductor very-large-scale integration electronics and silica fibre optics. Electro-optic devices have been fabricated exploiti...

  3. Rational design of organic electro-optic materials

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, L R [Departments of Chemistry and Electrical Engineering, University of Washington, Seattle, WA 98195-1700 (United States)

    2003-05-28

    Quantum mechanical calculations are used to optimize the molecular first hyperpolarizability of organic chromophores and statistical mechanical calculations are used to optimize the translation of molecular hyperpolarizability to macroscopic electro-optic activity (to values of greater than 100 pm V{sup -1} at telecommunications wavelengths). Macroscopic material architectures are implemented exploiting new concepts in nanoscale architectural engineering. Multi-chromophore-containing dendrimers and dendronized polymers not only permit optimization of electro-optic activity but also of auxiliary properties including optical loss (both absorption and scattering), thermal and photochemical stability and processability. New reactive ion etching and photolithographic techniques permit the fabrication of three-dimensional optical circuitry and the integration of that circuitry with semiconductor very-large-scale integration electronics and silica fibre optics. Electro-optic devices have been fabricated exploiting stripline, cascaded prism and microresonator device structures. Sub-1 V drive voltages and operational bandwidths of greater than 100 GHz have been demonstrated. Both single-and double-ring microresonators have been fabricated for applications such as active wavelength division multiplexing. Free spectral range values of 1 THz and per channel modulation bandwidths of 15 GHz have been realized permitting single-chip data rates of 500 Gb s{sup -1}. Other demonstrated devices include phased array radar, optical gyroscopes, acoustic spectrum analysers, ultrafast analog/digital converters and ultrahigh bandwidth signal generators. (topical review)

  4. Waveguide electro-optic modulators based on self-assembled material systems

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi-fu; MA Jing; SUN De-gui; XU Guo-yang; HO Seng-Tiong; ZHU Pei-wang; KANG Hu; Antonio Facchetti; Tobin J. Marks

    2005-01-01

    Fabrication and characterization of electro-optic modulators based on the novel organic electro-optic materials composed of self-assembled superlattices (SAS) were presented, both wet-dipping self-assembly and vapor phase deposition approaches were discussed. Prototype waveguide electro-optic modulators were fabricated using SAS films integrated with low-loss polymeric materials functioning as partial guiding and cladding layers.Promising electro-optic thin film materials including DTPT and PEPCOOH grown from the vapor phase were used for fabrication and test of electro-optic prototype modulators. Finally,the EO coefficient of tens of pm/V was obtained,which can sufficiently support high-speed and small size EO modulators.

  5. Material optimization for electro-optic modulation and cascading

    Science.gov (United States)

    Reyes, Jorge; Darracq, Bruno; Canva, Michael; Blanchard-Desce, Mireille H.; Chaput, Frederic; Lahlil, Khalid; Boilot, Jean-Pierre; Brun, Alain; Levy, Yves

    2000-11-01

    A large effort has been devoted to the preparation of organic polymeric materials for electro-optic modulation and more recently for cascading based processes. These materials contain push-pull chromophores either incorporated as guest in a high Tg polymeric matrix (doped polymers) or grafted onto the polymeric matrix. These systems present several advantages but require significant improvement at the molecular level- by designing optimized chromophores with very large molecular figure of merit specific to each application targeted. The sol-gel route was used to prepare hybrid organic-inorganic materials, for the fabrication of amorphous solids of various shapes (bulk, think films...). The results obtained on optimized chromophore-doped poled thin films emphasize that intermolecular interactions have to be taken into account, as already pointed out by Dalton and coworkers. By combining a molecular engineering strategy for getting large molecular figure of merit and by controlling the intermolecular dipole-dipole interactions via both tuning the push-pull chromophore concentration and the incorporation screening carbazole moieties in high concentration. This strategy allows us to obtain a r33 of about 50 pm/V at 831 nm for a new optimized chromophore structure. In parallel, these thin films are being processed to be used as passive components for integrated optics.

  6. Strained silicon as a new electro-optic material

    DEFF Research Database (Denmark)

    Jacobsen, Rune Shim; Andersen, Karin Nordström; Borel, Peter Ingo

    2006-01-01

    of a silicon waveguide, and the induced nonlinear coefficient, (2) 15 pm V-1, makes it possible to realize a silicon electro-optic modulator. The strain-induced linear electro-optic effect may be used to remove a bottleneck5 in modern computers by replacing the electronic bus with a much faster optical...... processing and transmission could potentially be performed by all-silicon electronic and optical components. Here we have discovered that a significant linear electro-optic effect is induced in silicon by breaking the crystal symmetry. The symmetry is broken by depositing a straining layer on top...... functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon3. Recently, however, a continuous-wave Raman silicon laser was demonstrated4; if an effective modulator could also be realized in silicon, data...

  7. Theory-Guided Design of Organic Electro-Optic Materials and Devices

    Directory of Open Access Journals (Sweden)

    Stephanie Benight

    2011-08-01

    Full Text Available Integrated (multi-scale quantum and statistical mechanical theoretical methods have guided the nano-engineering of controlled intermolecular electrostatic interactions for the dramatic improvement of acentric order and thus electro-optic activity of melt-processable organic polymer and dendrimer electro-optic materials. New measurement techniques have permitted quantitative determination of the molecular order parameters, lattice dimensionality, and nanoscale viscoelasticity properties of these new soft matter materials and have facilitated comparison of theoretically-predicted structures and thermodynamic properties with experimentally-defined structures and properties. New processing protocols have permitted further enhancement of material properties and have facilitated the fabrication of complex device structures. The integration of organic electro-optic materials into silicon photonic, plasmonic, and metamaterial device architectures has led to impressive new performance metrics for a variety of technological applications.

  8. Orientational dynamics in dye-doped organic electro-optic materials

    DEFF Research Database (Denmark)

    Apitz, D.; Svanberg, C.; Jespersen, K.G.

    2003-01-01

    The time dependent birefringence of polymer-based electro-optic materials is investigated using ellipsometry. We show that the birefringence after switching off the poling field does not depend only on the induced refractive index, but also on how that level was reached. The role of the poling...... voltage and poling time is discussed in turn-on and turn-off experiments and an original curve-fit function is introduced. We also propose a schematic model of the polymer dynamics in the system, which is consistent with complementary dielectric measurements. © 2003 American Institute of Physics. © 2003...

  9. Sol-Gel Material-Enabled Electro-Optic Polymer Modulators.

    Science.gov (United States)

    Himmelhuber, Roland; Norwood, Robert A; Enami, Yasufumi; Peyghambarian, Nasser

    2015-07-27

    Sol-gels are an important material class, as they provide easy modification of material properties, good processability and are easy to synthesize. In general, an electro-optic (EO) modulator transforms an electrical signal into an optical signal. The incoming electrical signal is most commonly information encoded in a voltage change. This voltage change is then transformed into either a phase change or an intensity change in the light signal. The less voltage needed to drive the modulator and the lower the optical loss, the higher the link gain and, therefore, the better the performance of the modulator. In this review, we will show how sol-gels can be used to enhance the performance of electro-optic modulators by allowing for designs with low optical loss, increased poling efficiency and manipulation of the electric field used for driving the modulator. The optical loss is influenced by the propagation loss in the device, as well as the losses occurring during fiber coupling in and out of the device. In both cases, the use of sol-gel materials can be beneficial due to the wide range of available refractive indices and low optical attenuation. The influence of material properties and synthesis conditions on the device performance will be discussed.

  10. Sol-Gel Material-Enabled Electro-Optic Polymer Modulators

    Directory of Open Access Journals (Sweden)

    Roland Himmelhuber

    2015-07-01

    Full Text Available Sol-gels are an important material class, as they provide easy modification of material properties, good processability and are easy to synthesize. In general, an electro-optic (EO modulator transforms an electrical signal into an optical signal. The incoming electrical signal is most commonly information encoded in a voltage change. This voltage change is then transformed into either a phase change or an intensity change in the light signal. The less voltage needed to drive the modulator and the lower the optical loss, the higher the link gain and, therefore, the better the performance of the modulator. In this review, we will show how sol-gels can be used to enhance the performance of electro-optic modulators by allowing for designs with low optical loss, increased poling efficiency and manipulation of the electric field used for driving the modulator. The optical loss is influenced by the propagation loss in the device, as well as the losses occurring during fiber coupling in and out of the device. In both cases, the use of sol-gel materials can be beneficial due to the wide range of available refractive indices and low optical attenuation. The influence of material properties and synthesis conditions on the device performance will be discussed.

  11. A deterministic guide for material and mode dependence of on-chip electro-optic modulator performance

    Science.gov (United States)

    Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

    2017-10-01

    Electro-optic modulation is a key function in optical data communication and possible future optical computing engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While high-performing modulators were demonstrated before, the approaches were taken as ad-hoc. Here we show the first systematic investigation to incorporate a holistic analysis for high-performance and ultra-compact electro-optic modulators on-chip. We show that intricate interplay between active modulation material and optical mode plays a key role in the device operation. Based on physical tradeoffs such as index modulation, loss, optical confinement factors and slow-light effects, we find that bias-material-mode regions exist where high phase modulation and high loss (absorption) modulation is found. This work paves the way for a holistic design rule of electro-optic modulators for on-chip integration.

  12. High Cost Performance Organic-Inorganic Hybrid Material for Electro-optic Devices

    Institute of Scientific and Technical Information of China (English)

    SUN Jie; ZHU Gui-Hua; SUN Xiao-Qiang; LI Tong; GAO Wei-Nan; ZHANG Da-Ming; HOU A-lin

    2009-01-01

    We report a low-cost electro-optic (EO) sol-gel material with large EO coefficient and excellent poling stability for EO devices. Disperse red 1 (DR1) chromophore is doped in the three-dimensional silicon dioxide/titanium dioxide network possessing a high γ33 (88pm/V at 1300 nm wavelength and 71 pm/V at 1550nm wavelength). Favourable poled stability (less than 5% relaxed after 2500 hours at 80 ℃) and low absorption are demonstrated. Strip-loaded waveguide Mach-Zehnder (M-Z) modulators are implemented based on this synthesized EO material, showing 7 V half-wave voltage and less than 9dB insertion loss at 1550nm wavelength.

  13. A magneto-electro-optical effect in a plasmonic nanowire material

    Science.gov (United States)

    Valente, João; Ou, Jun-Yu; Plum, Eric; Youngs, Ian J.; Zheludev, Nikolay I.

    2015-01-01

    Electro- and magneto-optical phenomena play key roles in photonic technology enabling light modulators, optical data storage, sensors and numerous spectroscopic techniques. Optical effects, linear and quadratic in external electric and magnetic field are widely known and comprehensively studied. However, optical phenomena that depend on the simultaneous application of external electric and magnetic fields in conventional media are barely detectable and technologically insignificant. Here we report that a large reciprocal magneto-electro-optical effect can be observed in metamaterials. In an artificial chevron nanowire structure fabricated on an elastic nano-membrane, the Lorentz force drives reversible transmission changes on application of a fraction of a volt when the structure is placed in a fraction-of-tesla magnetic field. We show that magneto-electro-optical modulation can be driven to hundreds of thousands of cycles per second promising applications in magneto-electro-optical modulators and field sensors at nano-tesla levels. PMID:25906761

  14. Structure/property relationships in non-linear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.M. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)]|[Durham Univ. (United Kingdom); Howard, J.A.K. [Durham Univ. (United Kingdom); McIntyre, G.J. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    The application of neutrons to the study of structure/property relationships in organic non-linear optical materials (NLOs) is described. In particular, charge-transfer effects and intermolecular interactions are investigated. Charge-transfer effects are studied by charge-density analysis and an example of one such investigation is given. The study of intermolecular interactions concentrates on the effects of hydrogen-bonding and an example is given of two structurally similar molecules with very disparate NLO properties, as a result of different types of hydrogen-bonding. (author). 3 refs.

  15. Electro-optic and magneto-dielectric properties of multifunctional nitride and oxide materials

    Science.gov (United States)

    Dixit, Ambesh

    Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties. Thin films of InN nitride compound semiconductors and closely related alloys have been investigated to understand the effects of intrinsic defects on the materials properties while considering possible applications of highly degenerate InN thin films. As grown rf sputtered InN films on c-axis (0001) sapphire exhibit highly degenerate n-type behaviour due to oxygen defects introduced during growth. The effect of oxygen in InN matrix has been further investigated by intentionally adding oxygen into the films. These studies confirm that oxygen is one of the main sources of donor electrons in degenerate InN. Above some critical concentration of oxygen, secondary phases of In 2O3 and In-O-N complexes were formed. It was also possible to tune the carrier concentration to produce changes in the plasmon frequency, which varied from 0.45 eV to 0.8 eV. This characteristic energy scale suggests that these highly degenerate InN thin films could be used for thermophotovoltaic cells, optical filters, and other IR electro-optic applications. To probe the magnetism in transition metal doped InN system, In 0.98Cr0.02N and In0.95Cr0.05N thin films were fabricated. Our results suggest that these films develop ferromagnetic order above room temperature

  16. INNOVATIONS IN THE SYNTHESIS AND CHARACTERIZATION OF ELECTRO-OPTICAL MATERIALS BASED ON POLYMERS WITH CARBAZOLIC SEQUENCES

    Directory of Open Access Journals (Sweden)

    Ionica Ionita

    2011-05-01

    Full Text Available We live in a complex world where revolutionary progress has been and continues to be made in communications, computer memory, and data processing. There is a growing need for new technologies that rapidly detect and treat diseases at an early stage or even pre-stage. As we are accustomed to these advances, our expectations will demand more compact, energy-efficient, rapidly responding, and environmentally safe technologies. Since the discovery of the photorefractive effect in organic polymers, carbazole-containing polymers have also attracted much attention because of their photoconductivity. In this context, multicomponent polymers with structural units containing both photoconductive and electro-optic functionalities in the side chain can be regarded as potentially suitable materials for photorefractive applications. Azobenzene photochemistry is a fascinating area of investigation, on one hand, because it is fairly well known, and on the other hand, because it has produced and continues to reveal completely unexpected phenomena, some of them still unexplained. When the azobenzene group is incorporated into a polymer, its photoisomerization can have a wide range of unexpected possible consequences. Connecting the carbazole sequence with azo sequence, using en spacer with  electrons, can enhance the electro-optical properties of the polymer materials based on carbazole. That can be realized first by (copolymerization of the monomers with the azo-carbazole sequences. Secondly, the chemical transformations of the polymers contented by (copolymerization of the known monomers with the carbazole monomers will be used. In these ideas the goal of this paper is an investigation of the scientifically literature regarding the new electro-active materials, peculiarly photorefractive alongside of our results in this field.

  17. Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

    CERN Document Server

    Ohtsu, Motoichi

    2005-01-01

    This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  18. Non-linear Constitutive Model for the Oligocarbonate Polyurethane Material

    Institute of Scientific and Technical Information of China (English)

    Marek Pawlikowski

    2014-01-01

    The polyurethane,which was the subject of the constitutive research presented in the paper,was based on oligocarbonate diols Desmophen C2100 produced by Bayer@.The constitutive modelling was performed with a view to applying the material as the inlay of intervertebral disc prostheses.The polyurethane was assumed to be non-linearly viscohyperelastic,isotropic and incompressible.The constitutive equation was derived from the postulated strain energy function.The elastic and rheological constants were identified on the basis of experimental tests,i.e.relaxation tests and monotonic uniaxial tests at two different strain rates,i.e.λ =0.1 min-1 and λ =1.0 min-1.The stiffness tensor was derived and introduced to Abaqus@finite element (FE) software in order to numerically validate the constitutive model.The results of the constants identification and numerical implementation show that the derived constitutive equation is fully adequate to model stress-strain behavior of the polyurethane material.

  19. Electro-optical properties of photochemically stable polymer-stabilized blue-phase material

    Energy Technology Data Exchange (ETDEWEB)

    Chojnowska, O., E-mail: ochojnowska@wat.edu.pl; Dąbrowski, R. [Institute of Chemistry, Military University of Technology, Warsaw 00-908 (Poland); Yan, J.; Chen, Y.; Wu, S. T. [College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816 (United States)

    2014-12-07

    Polymer-stabilized blue-phase liquid crystal (BPLC) comprising fluorinated compounds with high resistivity and photochemical stability is demonstrated. The Kerr constant, driving voltage, and response time of this BPLC are measured using an in-plane switching liquid crystal cell. At 20 °C, the measured total response time is faster than 0.7 ms and Kerr constant is 2 nm/V{sup 2}. This fluorinated BPLC material is a promising candidate for next-generation photonic and display devices, because it can be used in active matrix addressed devices.

  20. Investigation of Electron Transfer-Based Photonic and Electro-Optic Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Bromenshenk, Jerry J; Abbott, Edwin H; Dickensheets, David; Donovan, Richard P; Hobbs, J D; Spangler, Lee; McGuirl, Michele A; Spangler, Charles; Rebane, Aleksander; Rosenburg, Edward; Schmidt, V H; Singel, David J

    2008-03-28

    Montana's state program began its sixth year in 2006. The project's research cluster focused on physical, chemical, and biological materials that exhibit unique electron-transfer properties. Our investigators have filed several patents and have also have established five spin-off businesses (3 MSU, 2 UM) and a research center (MT Tech). In addition, this project involved faculty and students at three campuses (MSU, UM, MT Tech) and has a number of under-represented students, including 10 women and 5 Native Americans. In 2006, there was an added emphasis on exporting seminars and speakers via the Internet from UM to Chief Dull Knife Community College, as well as work with the MT Department of Commerce to better educate our faculty regarding establishing small businesses, licensing and patent issues, and SBIR program opportunities.

  1. Non-Linear Optical Studies of IR Materials with Infrared Femtosecond Laser

    Science.gov (United States)

    2016-12-15

    AFRL-RD-PS- AFRL-RD-PS- TR-2016-0055 TR-2016-0055 NON-LINEAR OPTICAL STUDIES OF IR MATERIALS WITH INFRARED FEMTOSECOND LASER Enam...ANDREAS SCHMITT-SODY, DR-III ERIN PETTYJOHN, DR-III Program Manager Deputy Chief, High Power Electromagnetics Division This...TITLE AND SUBTITLE Non-Linear Optical Studies of IR Materials with Infrared Femtosecond Laser 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9451-14-1

  2. Non-linear modeling of active biohybrid materials

    KAUST Repository

    Paetsch, C.

    2013-11-01

    Recent advances in engineered muscle tissue attached to a synthetic substrate motivate the development of appropriate constitutive and numerical models. Applications of active materials can be expanded by using robust, non-mammalian muscle cells, such as those of Manduca sexta. In this study, we propose a model to assist in the analysis of biohybrid constructs by generalizing a recently proposed constitutive law for Manduca muscle tissue. The continuum model accounts (i) for the stimulation of muscle fibers by introducing multiple stress-free reference configurations for the active and passive states and (ii) for the hysteretic response by specifying a pseudo-elastic energy function. A simple example representing uniaxial loading-unloading is used to validate and verify the characteristics of the model. Then, based on experimental data of muscular thin films, a more complex case shows the qualitative potential of Manduca muscle tissue in active biohybrid constructs. © 2013 Elsevier Ltd. All rights reserved.

  3. Effect of a Polymercaptan Material on the Electro-Optical Properties of Polymer-Dispersed Liquid Crystal Films

    Directory of Open Access Journals (Sweden)

    Yujian Sun

    2016-12-01

    Full Text Available Polymer-dispersed liquid crystal (PDLC films were prepared by the ultraviolet-light-induced polymerization of photopolymerizable monomers in nematic liquid crystal/chiral dopant/thiol-acrylate reaction monomer composites. The effects of the chiral dopant and crosslinking agents on the electro-optical properties of the PDLC films were systematically investigate. While added the chiral dopant S811 into the PDLC films, the initial off-state transmittance of the films was decreased. It was found that the weight ratio among acrylate monomers, thiol monomer PETMP and the polymercaptan Capcure 3-800 showed great influence on the properties of the fabricated PDLC films because of the existence of competition between thiol-acrylate reaction and acrylate monomer polymerization reaction. While adding polymercaptans curing agent Capcure 3-800 with appropriate concentration into the PDLC system, lower driven voltage and higher contrast ratio were achieved. This made the polymer network and electro-optical properties of the PDLC films easily tunable by the introduction of the thiol monomers.

  4. New Crystalline Materials for Nonlinear Frequency Conversion, Electro-Optic Modulation, and Mid-Infrared Gain Media

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J

    2002-08-09

    New crystalline materials were investigated for applications in frequency conversion of near-infrared wavelengths and as gain media for tunable mid-infrared solid-state lasers. GaCa{sub 4}O(BO{sub 3}){sub 3} (GdCOB), YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB), LaCa{sub 4}O(BO{sub 3}){sub 3} (LaCOB), and Gd{sub 0.275}Y{sub 0.725}Ca{sub 4}O(BO{sub 3}){sub 3} were characterized for frequency conversion of 1 {micro}m lasers. For type I doubling at 1064 nm, LaCOB, GdCOB, and YCOB were found to have effective coupling coefficients (d{sub eff}) of 0.52 {+-} 0.05, 0.78 {+-} 0.06, and 1.12 {+-} 0.07 pm/V, respectively. LaCOB was measured to have angular and thermal sensitivities of 1224 {+-} 184 (cm-rad){sup -1} and < 0.10 (cm-{sup o}C){sup -1}, respectively. The effective coupling coefficient for type II noncritically phasematched (NCPM) doubling at 1064 nm in Gd{sub 0.275}Y{sub 0.725}Ca{sub 4}O(BO{sub 3}){sub 3} was measured to be 0.37 {+-} 0.04 pm/V. We predict LaCOB to have a type I NCPM fundamental wavelength of 1042 {+-} 1.5 nm. Due to its low angular and thermal sensitivities for doubling near 1047 nm, LaCOB has potential for frequency doubling of high-average power Nd:LiYF{sub 4} and Yb:Sr{sub 5}(P0{sub 4}){sub 3}F lasers. LaCOB, GdCOB, and YCOB were also investigated for optical parametric oscillator applications and we determined that they may have potential in a Ti:sapphire pumped oscillator. The effective linear electro-optic coefficients (r{sub eff}) were measured along dielectric directions in YCOB and a maximum r{sub eff} of 10.8 pm/V was found. For a crystal with a 5:1 aspect ratio, the corresponding half-wave voltage at 1064 nm would be 19.6 kV. Therefore a Pockels cell composed of two YCOB crystals with 5:1 aspect ratios would have a required half-wave voltage <10 kV. Moderate coupling coefficients (3 x KH{sub 2}PO{sub 4}), low thermal sensitivities, ease of growth to large sizes, non-hygroscopicity, and favorable polishing and coating characteristics make La

  5. An electro-optic waveform interconnect based on quantum interference

    CERN Document Server

    Qin, Li-Guo; Gong, Shang-Qing

    2016-01-01

    The ability to modulate an optical field via an electric field is regarded as a key function of electro-optic interconnects, which are used in optical communications and information processing systems. One of the main required devices for such interconnects is the electro-optic modulator (EOM). Current EOM based on the electro-optic effect and the electro-absorption effect often is bulky and power inefficient due to the weak electro-optic properties of its constituent materials. Here we propose a new mechanism to produce an arbitrary-waveform EOM based on the quantum interference, in which both the real and imaginary parts of the susceptibility are engineered coherently with the superhigh efficiency. Based on this EOM, a waveform interconnect from the voltage to the modulated optical absorption is realised. We expect that such a new type of electro-optic interconnect will have a broad range of applications including the optical communications and network.

  6. The preparation and optical characterisation of novel organic crystals with applications in non linear devices

    CERN Document Server

    Wilkie, S

    2000-01-01

    In recent years, novel non-linear organic materials have generated great interest in the development of all-optical non-linear devices. Such materials have been optically characterised, mainly for the purposes of second harmonic generation and electro-optic modulation, within the Chemistry department of Strathclyde University since the mid-1980's. This thesis documents the continued development and enhancement of this core research speciality in the growth, preparation and optical characterisation of two such novel organic non-linear materials, namely NMU and MBANP. A literature search that reviewed the linear and non-linear optical properties of a select number of novel organic non-linear materials was conducted. All too often sample crystal quality was not detailed and hence the quality of crystals upon which the material characterisation was based remained unknown. Surprisingly, the availability of reliable, accurate data was found to be scarce. The optical investigation of NMU represented the first ever e...

  7. Electro-optic sampling of THz pulses at the CTR source at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, Steffen

    2012-06-15

    Several applications in material science, non-linear optics and solid-state physics require short pulses with a high pulse energy of radiation in the far-infrared and in the terahertz (THz) regime in particular. As described in the following, coherent transition radiation generated by high-relativistic electron bunches at FLASH provides broadband single-cycle pulses of sub-picosecond length. The pulses are characterized using the quantitative and time-resolved technique of electro-optic sampling showing peak field strengths in the order of 1 MV/cm.

  8. A new approach of binary addition and subtraction by non-linear material based switching technique

    Indian Academy of Sciences (India)

    Archan Kumar Das; Partha Partima Das; Sourangshu Mukhopadhyay

    2005-02-01

    Here, we refer a new proposal of binary addition as well as subtraction in all-optical domain by exploitation of proper non-linear material-based switching technique. In this communication, the authors extend this technique for both adder and subtractor accommodating the spatial input encoding system.

  9. Metal-organic frameworks as competitive materials for non-linear optics.

    Science.gov (United States)

    Mingabudinova, L R; Vinogradov, V V; Milichko, V A; Hey-Hawkins, E; Vinogradov, A V

    2016-09-26

    The last five years have witnessed a huge breakthrough in the creation and the study of the properties of a new class of compounds - metamaterials. The next stage of this technological revolution will be the development of active, controllable, and non-linear metamaterials, surpassing natural media as platforms for optical data processing and quantum information applications. However, scientists are constantly faced with the need to find new methods that can ensure the formation of quantum and non-linear metamaterials with higher resolution. One such method of producing metamaterials in the future, which will provide scalability and availability, is chemical synthesis. Meanwhile, the chemical synthesis of organized 3D structures with a period of a few nanometers and a size of up to a few millimeters is not an easy task and is yet to be resolved. The most promising avenue seems to be the use of highly porous structures based on metal-organic frameworks that have demonstrated their unique properties in the field of non-linear optics (NLO) over the past three years. Thus, the aim of this review is to examine current progress and the possibilities of using metal-organic frameworks in the field of non-linear optics as chemically obtained metamaterials of the future. The review begins by presenting the theoretical principles of physical phenomena represented by mathematical descriptions for clarity. Major attention is paid to the second harmonic generation (SHG) effect. In this section we compare inorganic single crystals, which are most commonly used to study the effect in question, to organic materials, which also possess the required properties. Based on these data, we present a rationale for the possibility of studying the non-linear optical properties of metal-organic structures as well as describing the use of synthetic approaches and the difficulties associated with them. The second part of the review explicitly acquaints the reader with a new class of materials

  10. High frequency electro-optic measurement of strained silicon racetrack resonators

    CERN Document Server

    Borghi, M; Merget, F; Witzens, J; Bernard, M; Ghulinyan, M; Pucker, G; Pavesi, L

    2015-01-01

    The observation of the electro-optic effect in strained silicon waveguides has been considered as a direct manifestation of an induced $\\chi^{(2)}$ non-linearity in the material. In this work, we perform high frequency measurements on strained silicon racetrack resonators. Strain is controlled by a mechanical deformation of the waveguide. It is shown that any optical modulation vanishes independently of the applied strain when the applied voltage varies much faster than the carrier effective lifetime, and that the DC modulation is also largely independent of the applied strain. This demonstrates that plasma carrier dispersion is responsible for the observed electro-optic effect. After normalizing out free carrier effects, our results set an upper limit of $8\\,pm/V$ to the induced high-speed $\\chi^{(2)}_{eff,zzz}$ tensor element at an applied stress of $-0.5\\,GPa$. This upper limit is about one order of magnitude lower than the previously reported values for static electro-optic measurements.

  11. A non-linear homogeneous model for bone-like materials under compressive load.

    Science.gov (United States)

    Mengoni, M; Voide, R; de Bien, C; Freichels, H; Jérôme, C; Léonard, A; Toye, D; Müller, R; van Lenthe, G H; Ponthot, J P

    2012-02-01

    Finite element (FE) models accurately compute the mechanical response of bone and bone-like materials when the models include their detailed microstructure. In order to simulate non-linear behavior, which currently is only feasible at the expense of extremely high computational costs, coarser models can be used if the local morphology has been linked to the apparent mechanical behavior. The aim of this paper is to implement and validate such a constitutive law. This law is able to capture the non-linear structural behavior of bone-like materials through the use of fabric tensors. It also allows for irreversible strains using an elastoplastic material model incorporating hardening. These features are expressed in a constitutive law based on the anisotropic continuum damage theory coupled with isotropic elastoplasticity in a finite strain framework. This material model was implemented into metafor (LTAS-MNNL, University of Liège, Belgium), a non-linear FE software. The implementation was validated against experimental data of cylindrical samples subjected to compression. Three materials with bone-like microstructure were tested: aluminum foams of variable density (ERG, Oakland, CA, USA), polylactic acid foam (CERM, University of Liège, Liège, Belgium), and cancellous bone tissue of a deer antler (Faculty of Veterinary Medicine, University of Liège, Liège, Belgium).

  12. Non-linear model of impurity diffusion in nanoporous materials upon ultrasonic treatment

    Directory of Open Access Journals (Sweden)

    R.M. Peleshchak

    2014-06-01

    Full Text Available Non-linear theory of diffusion of impurities in porous materials upon ultrasonic treatment is described. It is shown that at a defined value of deformation amplitude, an average concentration of vacancies and temperature as a result of the effect of ultrasound possibly leads to the formation of nanoclusters of vacancies and to their periodic educations in porous materials. It is shown that at a temperature smaller than some critical value, a significant growth of a diffusion coefficient is observed in porous materials.

  13. An electro-optical and electron injection study of benzothiazole-based squaraine dyes as efficient dye-sensitized solar cell materials: a first principles study.

    Science.gov (United States)

    Al-Fahdan, Najat Saeed; Asiri, Abdullah M; Irfan, Ahmad; Basaif, Salem A; El-Shishtawy, Reda M

    2014-12-01

    Squaraine dyes have attracted significant attention in many areas of daily life from biomedical imaging to semiconducting materials. Moreover, these dyes are used as photoactive materials in the field of solar cells. In the present study, we investigated the structural, electronic, photophysical, and charge transport properties of six benzothiazole-based squaraine dyes (Cis-SQ1-Cis-SQ3 and Trans-SQ1-Trans-SQ3). The effect of electron donating (-OCH3) and electron withdrawing (-COOH) groups was investigated intensively. Ground state geometry and frequency calculations were performed by applying density functional theory (DFT) at B3LYP/6-31G** level of theory. Absorption spectra were computed in chloroform at the time-dependent DFT/B3LYP/6-31G** level of theory. The driving force of electron injection (ΔG (inject)), relative driving force of electron injection (ΔG r (inject)), electronic coupling constants (|VRP|) and light harvesting efficiency (LHE) of all six compounds were calculated and compared with previously studied sensitizers. The ΔG (inject), ΔG r (inject) and |VRP| of all six compounds revealed that these sensitizers would be efficient dye-sensitized solar cell materials. Cis/Trans-SQ3 exhibited superior LHE as compared to other derivatives. The Cis/Trans geometric effect was studied and discussed with regard to electro-optical and charge transport properties.

  14. Electro-optic methods for longitudinal bunch diagnostics at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, B.R.

    2007-07-15

    Precise measurements of the temporal profile of sub-picosecond electron bunches are of high interest for the optimization and operation of VUV and X-ray free electron lasers. In this thesis, the shortest electro-optic signals measured so far for electron bunch diagnostics are presented, reaching a time resolution of better than 50 fs (rms). The e ects that introduce signal distortions and limit the time resolution are studied in numerical simulations for different electro-optic detection materials and techniques. The time resolution is mainly limited by lattice resonances of the electro-optic crystal. Electro-optic signals as short as 54 fs (rms) are obtained with gallium phosphide (GaP) crystals in a crossed polarizer detection scheme using temporally resolved electro-optic detection. Measuring near crossed polarization, where the electro-optic signal is proportional to the velocity field of the relativistic electron bunch, the shortest obtained signal width is 70 fs (rms). The electro-optic signals are compared to electron bunch shapes that are measured simultaneously with a transverse deflecting structure with 20 fs resolution. Numerical simulations using the bunch shapes as determined with the transverse deflecting cavity as input data are in excellent agreement with electro-optical signals obtained with GaP, both for temporally and spectrally resolved measurements. In the case of zinc telluride (ZnTe) the observed signals are slightly broader and significantly smaller than expected from simulations. These discrepancies are probably due to the poor optical quality of the available ZnTe crystals. (orig.)

  15. An all-optical matrix multiplication scheme with non-linear material based switching system

    Institute of Scientific and Technical Information of China (English)

    Archan Kumar Das; Sourangshu Mukhopadhyay

    2005-01-01

    Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of parallelism. Several optical methods are proposed in support of the above processing. In many algebraic,arithmetic, and image processing schemes fundamental logic and memory operations are conducted exploring all-optical devices. In this communication we report an all-optical matrix multiplication operation with non-linear material based switching circuit.

  16. Results from the electro-optic sensors domain of the materials and components for missiles innovation and technology partnership (phase 1)

    Science.gov (United States)

    Bray, Mark E.; Shears, Robert A.

    2013-10-01

    The Materials and Components for Missiles Innovation and Technology Partnership (ITP) is a research programme supporting research for guided weapons at Technology Readiness Levels 1 to 4. The Anglo-French initiative is supported by the DGA and the MoD, with matched funding from industry. A major objective is to foster projects which partner UK and French universities, SMEs and larger companies. The first projects started in January 2008 and the first phase completed in spring 2013. Providing funding is secured, the next phase of the programme is due to start later in 2013. Selex ES leads Domain 3 of the MCM-ITP which develops Electro-Optic sensor technology. In collaboration with DGA, MoD and MBDA, the prime contractor, we identified 4 key objectives for the first ITP phase and focussed resources on achieving these. The objectives were to enable better imagery, address operationally stressing scenarios, provide low overall through life cost and improve active and semi-active sensors Nine normal projects and one ITP innovation fund project have been supported within the domain. The technology providers have included 3 SMEs and 8 research centres from both the United Kingdom and France. Highlights of the projects are included. An outline of the priorities for the domain for the new phase ise provided and we encourage organisations with suitable technology to contact us to get involved.

  17. Electro-Optic System Development Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Electro-Optic System Development Lab serves as a development facility for electro-optical systems ranging from visible through long wave infrared. Capabilities...

  18. Electro-optical properties of polymer stabilized cholesteric liquid crystal film

    Institute of Scientific and Technical Information of China (English)

    Ma Ji; Zheng Zhi-Gang; Liu Yong-Gang; Xuan Li

    2011-01-01

    Liquid crystals (LCs) and polymers are extensively used in various electro-optical applications. In this paper, normal mode polymer stabilized cholesteric LC film is prepared and studied. The effects of chiral dopant and monomer concentrations on the electro-optical properties, such as contrast ratio, driving voltage, hysteresis width and response time, are investigated. The reasons of electro-optical properties influenced by the concentrations of the materials are discussed. Through the proper material recipe, the electro-optical properties of polymer stabilized cholesteric LC film can be optimized.

  19. Non-linear, visual-rich supplemental material designed for an introductory course in veterinary anesthesia.

    Science.gov (United States)

    Dyson, Doris H

    2003-01-01

    A possible reason for superficial learning in an introductory anesthesia course was considered to be a lack of visual reinforcement at the time of examination preparation. Students had limited access to live animal laboratories and clinical cases during the course, reducing their ability to depend on experiential learning. In an attempt to improve student learning, simple presentation software was used to develop a supplemental CD. The design involved multiple PowerPoint presentations that incorporated text, pictures, videos, and self-assessments. Non-linear exploration of the topics covered was made possible by extensive use of hyperlinks within and between presentations, moving the student to definitions, background material, videos, advanced details, and previously covered information. Comments received from students on a prototype were positive overall, and improvements were made related to their feedback. Other supplemental materials and lecture presentations can easily incorporate the techniques described here.

  20. Performance analysis of flow lines with non-linear flow of material

    CERN Document Server

    Helber, Stefan

    1999-01-01

    Flow line design is one of the major tasks in production management. The decision to install a set of machines and buffers is often highly irreversible. It determines both cost and revenue to a large extent. In order to assess the economic impact of any possible flow line design, production rates and inventory levels have to be estimated. These performance measures depend on the allocation of buffers whenever the flow of material is occasionally disrupted, for example due to machine failures or quality problems. The book describes analytical methods that can be used to evaluate flow lines much faster than with simulation techniques. Based on these fast analytical techniques, it is possible to determine a flow line design that maximizes the net present value of the flow line investment. The flow of material through the line may be non-linear, for example due to assembly operations or quality inspections.

  1. Numerical estimation of 3D mechanical forces exerted by cells on non-linear materials.

    Science.gov (United States)

    Palacio, J; Jorge-Peñas, A; Muñoz-Barrutia, A; Ortiz-de-Solorzano, C; de Juan-Pardo, E; García-Aznar, J M

    2013-01-04

    The exchange of physical forces in both cell-cell and cell-matrix interactions play a significant role in a variety of physiological and pathological processes, such as cell migration, cancer metastasis, inflammation and wound healing. Therefore, great interest exists in accurately quantifying the forces that cells exert on their substrate during migration. Traction Force Microscopy (TFM) is the most widely used method for measuring cell traction forces. Several mathematical techniques have been developed to estimate forces from TFM experiments. However, certain simplifications are commonly assumed, such as linear elasticity of the materials and/or free geometries, which in some cases may lead to inaccurate results. Here, cellular forces are numerically estimated by solving a minimization problem that combines multiple non-linear FEM solutions. Our simulations, free from constraints on the geometrical and the mechanical conditions, show that forces are predicted with higher accuracy than when using the standard approaches.

  2. Non-linear states of a positive or negative refraction index material in a cavity with feedback

    Science.gov (United States)

    Mártin, D. A.; Hoyuelos, M.

    2010-06-01

    We study a system composed by a cavity with plane mirrors containing a positive or negative refraction index material with third order effective electric and magnetic non-linearities. The aim of the work is to present a general picture of possible non-linear states in terms of the relevant parameters of the system. The parameters are the ones that appear in a reduced description that has the form of the Lugiato-Lefever equation. This equation is obtained from two coupled non-linear Schrödinger equations for the electric and magnetic field amplitudes.

  3. Exploring the synthesis of hexaborides: The basis of a new chemistry for the preparation of electro-optical materials

    Science.gov (United States)

    Kanakala, Raghunath

    Magnetic, electric, and physical properties, of the rare earth metal borides are of special interest. The covalent bonding between the boron atoms in these materials imparts a great strength, stability, and high melting point to these borides. LaB6 finds additional applications as an electron emission material in the cathode units of electron microscopes, which need point sources for formation of the electron beam with high current density. Also, thin films of LaB6 are potential candidates for plasma devices because of the high secondary electron emission coefficient. Thus, the main aim of this research was to synthesize LaB6, SmB6, and YB6, materials through a simple and easy to scale up combustion process. To the best of our knowledge, this is the first report of a low temperature combustion synthesis method for producing rare-earth hexaboride materials. We have performed an in-depth exploration of the ideal processing conditions for the synthesis of hexaboride materials using easy to handle chemicals and low processing temperatures via combustion synthesis. Previous reports on the synthesis of hexaboride materials makes use of highly toxic and dangerous gases as precursor materials. Thus, our technique is superior to any other chemical schemes for producing hexaboride materials. In this project, different precursors were used in the experiments in order to explore reaction mechanisms. Boron powders from Sigma-Aldrich, which had an average particle size of 1--5 mum, and boron powders from Noval Industrial Group, which had an average particle size around 500 nm, were used. The final results showed that boride materials synthesized using the boron from Noval Industrial Group yielded highly unagglomerated powders, although the average particle size is similar to that of the powders synthesized using the boron from Sigma-Aldrich. Combustion synthesis without water and with gradual heating of the powders yielded the best results. The powders in the as

  4. Crystal growth of an organic non-linear optical material from the vapour phase

    CERN Document Server

    Hou, W

    1999-01-01

    Due to the potential applications of organic non-linear optical materials in the areas of optical processing and communication, the investigation of the crystal growth of new organic NLO materials has been an active field for the last 20 years. For such uses it is necessary to produce single crystals of high quality and perfection, free of strain and defects. When crystals are grown from the solution and the melt, solvent and the decomposition component in the melt can introduce impurities and imperfection to the as-grown crystals. For crystals grown from vapour phase, in the absence of the solvent, this cannot occur and the method promises to yield single crystals of higher quality. Despite this attraction, little attention has been paid to the vapour phase growth of organic NLO crystals. It was with this in mind that the following investigation was carried out. Using Methyl p-hydroxybenzoate (p-MHB), a potential organic NLO material, a comparison investigation was made of its crystal growth from both the va...

  5. Missile Electro-Optical Countermeasures Simulation Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory comprises several hardware-in-the-loop missile flight simulations designed specifically to evaluate the effectiveness of electro-optical air defense...

  6. Electro-Optics/Low Observables Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Electro-Optics/Low Observables Laboratory supports graduate instruction for students enrolled in the Low Observables program. Its purpose is to introduce these...

  7. Cavity equations for a positive or negative refraction index material with electric and magnetic non-linearities

    CERN Document Server

    Mártin, Daniel A; 10.1103/PhysRevE.80.056601

    2012-01-01

    We study evolution equations for electric and magnetic field amplitudes in a ring cavity with plane mirrors. The cavity is filled with a positive or negative refraction index material with third order effective electric and magnetic non-linearities. Two coupled non-linear equations for the electric and magnetic amplitudes are obtained. We prove that the description can be reduced to one Lugiato Lefever equation with generalized coefficients. A stability analysis of the homogeneous solution, complemented with numerical integration, shows that any combination of the parameters should correspond to one of three characteristic behaviors.

  8. Expanded porphyrins as third order non-linear optical materials: Some structure-function correlations

    Indian Academy of Sciences (India)

    Sabapathi Gokulnath; Tavarekere K Chandrashekar

    2008-01-01

    In this paper, the non-linear optical properties of representative core-modified expanded porphyrins have been investigated with an emphasis on the structure-property relationship between the aromaticity and conformational behaviour. It has been shown that the measured two-photon absorption cross section (2) values depend on the structure of macrocycle, its aromaticity and the number of -electrons in conjugation.

  9. A new method of binary addition scheme with massive use of non-linear material based system

    Institute of Scientific and Technical Information of China (English)

    Kuladeep Roy Chowdhury; Sourangshu Mukhopadhyay

    2003-01-01

    The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speedperformance (above GHz) are not expected at all in conventional electronic mechanism. To achieve highspeed performance we may think on the introduction of optics instead of electronics for information pro-cessing and computing. Non-linear optical material is a successful candidate in this regard to play a majorrole in the optically controlled switching systems and therefore in all-optical parallel computation thesematerials can show a very good potential aspect. In this paper, we have proposed a new method of anoptical half adder as well as full adder circuit for binary addition using non-linear and linear optical ma-terials.

  10. Fiber Acousto-Electro-Optic Modulator

    Institute of Scientific and Technical Information of China (English)

    Anen; Jiang

    2003-01-01

    A new kind of fiber acousto-electro-optic modulator is made by using Lithium Niobate crystal. This kind of modulator can be used in fiber communication, and its center frequency can be changed by directed current voltages.

  11. Numerical scheme for non-linear model of supercritical fluid extraction from polydisperse ground plant material: single transport system

    Science.gov (United States)

    Salamatin, A.

    2016-11-01

    Numerical algorithm is developed for modelling non-linear mass transfer process in supercritical fluid extraction (SFE). The ground raw material is considered as polydisperse, characterized by discrete number of effective particle fractions. Two continuous interacting counterparts separated by permeable membrane are distinguished in plant material build-up. The apoplast plays role of transport channels during extraction, and symplast contains extractable oil. The complete SFE model is non-linear as a result of non-linearity of oil dissolution kinetics. The computational scheme is based on the finite-volume approximation method and Thomas elimination procedure. The resulting system of algebraic equations is solved iteratively. Special attention is paid to polydisperse substrates, when particle scale characteristics of all fractions interact with each other through pore phase concentration on the vessel scale. Stability of the developed algorithm is demonstrated in numerical tests. Special iterative procedure guarantees a monotonic decrease of oil content in individual particles of substrate. It is also shown that in the limit of the so-called shrinking core approach the number of mesh nodes on a particle scale should be increased.

  12. Innovative, Inexpensive Etching Technique Developed for Polymer Electro- Optical Structures

    Science.gov (United States)

    Nguyen, Hung D.

    1999-01-01

    Electro-optic, polymer-based integrated optic devices for high-speed communication and computing applications offer potentially significant advantages over conventional inorganic electro-optic crystals. One key area of integrated optical technology--primary processing and fabrication--may particularly benefit from the use of polymer materials. However, as efforts concentrate on the miniaturization of electro-integrated circuit pattern geometries, the ability to etch fine features and smoothly sloped sidewalls is essential to make polymers useful for electro-integrated circuit applications. There are many existing processes available to etch polymer materials, but they all yield nearly vertical sidewalls. Vertical sidewalls are too difficult to reliably cover with a metal layer, and incomplete metalization degrades microwave performance, particularly at high frequency. However, obtaining a very sloped sidewall greatly improves the deposition of metal on the sidewall, leading to low-loss characteristics, which are essential to integrating these devices in highspeed electro-optic modulators. The NASA Lewis Research Center has developed in-house an inexpensive etching technique that uses a photolithography method followed by a simple, wet chemical etching process to etch through polymer layers. In addition to being simpler and inexpensive, this process can be used to fabricate smoothly sloped sidewalls by using a commercial none rodible mask: Spin-On-Glass. A commercial transparent material, Spin-On-Glass, uses processes and equipment similar to that for photoresist techniques.

  13. Applications of lasers and electro-optics

    Science.gov (United States)

    Tan, B. C.; Low, K. S.; Chen, Y. H.; Ahmad, Harith; Tou, T. Y.

    Supported by the IRPA Programme on Laser Technology and Applications, many types of lasers have been designed, constructed and applied in various areas of science, medicine and industries. Amongst these lasers constructed were high power carbon dioxide lasers, rare gas halide excimer lasers, solid state Neodymium-YAG lasers, nitrogen lasers, flashlamp pumped dye lasers and nitrogen and excimer laser pumped dye lasers. These lasers and the associated electro-optics system, some with computer controlled, are designed and developed for the following areas of applications: (1) industrial applications of high power carbon dioxide lasers for making of i.c. components and other materials processing purposes -- prototype operational systems have been developed; (2) Medical applications of lasers for cancer treatment using the technique of photodynamic therapy -- a new and more effective treatment protocol has been proposed; (3) agricultural applications of lasers in palm oil and palm fruit-fluorescence diagnostic studies -- fruit ripeness signature has been developed and palm oil oxidation level were investigated; (4) development of atmospheric pollution monitoring systems using laser lidar techniques -- laboratory scale systems were developed; and (5) other applications of lasers including laser holographic and interferometric methods for the non destructive testing of materials.

  14. Electro-optical switching of liquid crystals of graphene oxide

    Science.gov (United States)

    Song, Jang-Kun

    Electric field effects on aqueous graphene-oxide (GO) dispersions are reviewed in this chapter. In isotropic and biphasic regimes of GO dispersions, in which the inter-particle friction is low, GO particles sensitively respond to the application of electric field, producing field-induced optical birefringence. The electro-optical sensitivity dramatically decreases as the phase transits to the nematic phase; the increasing inter-particle friction hinders the rotational switching of GO particles. The corresponding Kerr coefficient reaches the maximum near the isotropic to biphasic transition concentration, at which the Kerr coefficient is found be c.a. 1:8 · 10-5 mV-2, the highest value ever reported in all Kerr materials. The exceptionally large Kerr effect arises from the Maxwell- Wagner polarization of GO particles with an extremely large aspect ratio and a thick electrical double layer (EDL). The polarization sensitively depends on the ratio of surface and bulk conductivities in dispersions. As a result, low ion concentration in bulk solvent is highly required to achieve a quality electro-optical switching in GO dispersions. Spontaneous vinylogous carboxylic reaction in GO particles produces H+ ions, resulting in spontaneous degradation of electro-optical response with time, hence the removal of residual ions by using a centrifuge cleaning process significantly improves the electro-optical sensitivity. GO particle size is another important parameter for the Kerr coefficient and the response time. The best performance is observed in a GO dispersion with c.a. 0.5 μm mean size. Dielectrophoretic migration of GO particles can be also used to manipulate GO particles in solution. Using these unique features of GO dispersions, one can fabricate GO liquid crystal devices similar to conventional liquid crystal displays; the large Kerr effect allows fabricating a low power device working at extremely low electric fields.

  15. A norbornene polymer brush for electro-optic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yue; Spring, Andrew M.; Yu, Feng; Yamamoto, Kazuhiro [Institute for Materials Chemistry and Engineering, Kyushu University, 6–1 Kasuga Fukuoka 816–8580 (Japan); Aoki, Isao; Otomo, Akira [National Institute of Information and Communications Technology, 588–2 Iwaoka, Nishi-ku, Kobe 651–2492 (Japan); Yokoyama, Shiyoshi, E-mail: s_yokoyama@cm.kyushu-u.ac.jp [Institute for Materials Chemistry and Engineering, Kyushu University, 6–1 Kasuga Fukuoka 816–8580 (Japan)

    2014-03-03

    Norbornene-dicarboximide derived polymer brushes containing Disperse Red 1 appended chromophores have been prepared by sequencial ring opening metathesis polymerization and atom transfer radical polymerization. This brush was then employed as an electro-optic polymer host for high molecular hyperpolarizability phenyl vinylene thiophene vinylene (FTC) bridge chromophores in a binary chromophore system. The r{sub 33} of the polymer brush/bi-chromophore network was evaluated via in situ poling and was measured as 94 pm/V compared to the benchmark polymethylmethacrylate (PMMA) system of 76 pm/V with an identical chromophore. Furthermore, our polymer brush/bi-chromophore network exhibited an enhanced poling efficiency of 1.37 (nm/V){sup 2} as compared to a simple PMMA - FTC host - guest 0.70 (nm/V){sup 2}. - Highlights: • Synthesis of a norbornene polymer brush. • Use of this polymer brush as a host for electro-optic materials. • The polymer brush enables a large electro-optic coefficient r{sub 33}.

  16. Updated Lagrangian finite element formulations of various biological soft tissue non-linear material models: a comprehensive procedure and review.

    Science.gov (United States)

    Townsend, Molly T; Sarigul-Klijn, Nesrin

    2016-01-01

    Simplified material models are commonly used in computational simulation of biological soft tissue as an approximation of the complicated material response and to minimize computational resources. However, the simulation of complex loadings, such as long-duration tissue swelling, necessitates complex models that are not easy to formulate. This paper strives to offer the updated Lagrangian formulation comprehensive procedure of various non-linear material models for the application of finite element analysis of biological soft tissues including a definition of the Cauchy stress and the spatial tangential stiffness. The relationships between water content, osmotic pressure, ionic concentration and the pore pressure stress of the tissue are discussed with the merits of these models and their applications.

  17. Synthesis and non linear optical properties of new inorganic-organic hybrid material: 4-Benzylpiperidinium sulfate monohydrate

    Science.gov (United States)

    Kessentini, Yassmin; Ahmed, Ali Ben; Al-Juaid, Salih S.; Mhiri, Tahar; Elaoud, Zakaria

    2016-03-01

    Single crystals of 4-benzyl-piperidine sulfate monohydrate were grown by slow evaporation method at room temperature. The synthesized compound was characterized by means of single-crystal X-ray diffraction, FT-IR and Raman spectroscopy, UV-visible and photoluminescence studies. The title compound crystallises at room temperature in the non centrosymmetric space group P212121.The recorded UV-visible spectrum show good transparency in the visible region and indicates a non-zero value of the first Hyperpolarizability. Photoluminescence spectrum shows a broad and intense band at 440 nm and indicates that the crystal emits blue fluorescence. We also report DFT calculations of the electric dipole moments (μ), Polarizability (α), the static first Hyperpolarizability (β) and HOMO-LUMO analysis of the title compound was theoretically investigated by GAUSSIAN 03 package. The calculated static first Hyperpolarizability is equal to 6.4022 × 10-31 esu. The results show that 4-benzyl-piperidine sulfate monohydrate crystal might have important non linear optical behavior and can be a potential non linear optical material of interest.

  18. Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems

    Energy Technology Data Exchange (ETDEWEB)

    Massoudi, M.C.; Tran, P.X.

    2006-01-01

    We discuss three boundary value problems in the flow and heat transfer analysis in flowing granular materials: (i) the flow down an inclined plane with radiation effects at the free surface; (ii) the natural convection flow between two heated vertical walls; (iii) the shearing motion between two horizontal flat plates with heat conduction. It is assumed that the material behaves like a continuum, similar to a compressible nonlinear fluid where the effects of density gradients are incorporated in the stress tensor. For a fully developed flow the equations are simplified to a system of three nonlinear ordinary differential equations. The equations are made dimensionless and a parametric study is performed where the effects of various dimensionless numbers representing the effects of heat conduction, viscous dissipation, radiation, and so forth are presented.

  19. Understanding of Materials State and its Degradation using Non-Linear Ultrasound (NLU) Approaches

    Science.gov (United States)

    2011-07-01

    at Ultrasonic Frequencies, Journal of Applied Physics 105, 043520, Hikata A., Chick B. B., and Elbaum C., (1965) Dislocation Contribution to the...Second Harmonic Generation of ultrasonic waves, Journal of Applied Physics Vol. 36 Number1 Hikata A. and Elbaum C., (1966) Generation of...Material Damage in a Nickel-base Superalloy using Nonlinear Rayleigh Surface Waves, Journal of Applied Physics 99, 124913 Hurley D. C., Balzar D

  20. Fluorinated and Non-Fluorinated Electro-Optic Copolymers: Determination of the Time and Temperature Stability of the Induced Electro-Optic Coefficient

    Directory of Open Access Journals (Sweden)

    Alessandro Belardini

    2012-10-01

    Full Text Available Organic fluorinated materials demonstrate their excellent electro-optic properties and versatility for technological applications. The partial substitution of hydrogen with fluorine in carbon-halides bounds allows the reduction of absorption losses at the telecommunication wavelengths. In these interesting compounds, the electro-optic coefficient was typically induced by a poling procedure. The magnitude and the time stability of the coefficient is an important issue to be investigated in order to compare copolymer species. Here, a review of different measurement techniques (such as nonlinear ellipsometry, second harmonic generation, temperature scanning and isothermal relaxation was shown and applied to a variety of fluorinated and non-fluorinated electro-optic compounds.

  1. The Electro-Optic Beam Position Monitor

    CERN Document Server

    Doherty, James

    2013-01-01

    This reports outlines the development of a new ultra-wideband electro-optic beam position monitor (EO-BPM) for use in the Large Hadron Collider (LHC) which utilises birefringent crystals and the Pockels effect to monitor beam position. The physical principles behind the operation of the device and tested topology, which incorporates two Lithium Tantalate crystals, is discussed.

  2. Basic electro-optics for electrical engineers

    CERN Document Server

    Boreman, Glenn D

    1999-01-01

    This text introduces imaging, radiometry, sources, detectors, and lasers, with special emphasis on flux-transfer issues. The first-order approach enables students to make back-of-the-envelope calculations needed for initial setup of optical apparatus. It is intended for students and newcomers to electro-optics.

  3. Analysis of linear elasticity and non-linearity due to plasticity and material damage in woven and biaxial braided composites

    Science.gov (United States)

    Goyal, Deepak

    Textile composites have a wide variety of applications in the aerospace, sports, automobile, marine and medical industries. Due to the availability of a variety of textile architectures and numerous parameters associated with each, optimal design through extensive experimental testing is not practical. Predictive tools are needed to perform virtual experiments of various options. The focus of this research is to develop a better understanding of linear elastic response, plasticity and material damage induced nonlinear behavior and mechanics of load flow in textile composites. Textile composites exhibit multiple scales of complexity. The various textile behaviors are analyzed using a two-scale finite element modeling. A framework to allow use of a wide variety of damage initiation and growth models is proposed. Plasticity induced non-linear behavior of 2x2 braided composites is investigated using a modeling approach based on Hill's yield function for orthotropic materials. The mechanics of load flow in textile composites is demonstrated using special non-standard postprocessing techniques that not only highlight the important details, but also transform the extensive amount of output data into comprehensible modes of behavior. The investigations show that the damage models differ from each other in terms of amount of degradation as well as the properties to be degraded under a particular failure mode. When compared with experimental data, predictions of some models match well for glass/epoxy composite whereas other's match well for carbon/epoxy composites. However, all the models predicted very similar response when damage factors were made similar, which shows that the magnitude of damage factors are very important. Full 3D as well as equivalent tape laminate predictions lie within the range of the experimental data for a wide variety of braided composites with different material systems, which validated the plasticity analysis. Conclusions about the effect of

  4. Simulations of heart valves by thin shells with non-linear material properties

    Science.gov (United States)

    Borazjani, Iman; Asgharzadeh, Hafez; Hedayat, Mohammadali

    2016-11-01

    The primary function of a heart valve is to allow blood to flow in only one direction through the heart. Triangular thin-shell finite element formulation is implemented, which considers only translational degrees of freedom, in three-dimensional domain to simulate heart valves undergoing large deformations. The formulation is based on the nonlinear Kirchhoff thin-shell theory. The developed method is intensively validated against numerical and analytical benchmarks. This method is added to previously developed membrane method to obtain more realistic results since ignoring bending forces can results in unrealistic wrinkling of heart valves. A nonlinear Fung-type constitutive relation, based on experimentally measured biaxial loading tests, is used to model the material properties for response of the in-plane motion in heart valves. Furthermore, the experimentally measured liner constitutive relation is used to model the material properties to capture the flexural motion of heart valves. The Fluid structure interaction solver adopts a strongly coupled partitioned approach that is stabilized with under-relaxation and the Aitken acceleration technique. This work was supported by American Heart Association (AHA) Grant 13SDG17220022 and the Center of Computational Research (CCR) of University at Buffalo.

  5. A natural neighbour method based on Fraeijs de Veubeke variational principle for materially non-linear problems

    Institute of Scientific and Technical Information of China (English)

    Xiang Li; Serge Cescotto; Barbara Rossi

    2009-01-01

    The natural neighbour method can be considered as one of many variants of the meshless methods. In the present paper, a new approach based on the Fraeijs de Veubeke (FdV) functional, which is initially developed for linear elasticity, is extended to the case of geometrically linear but materially non-linear solids. The new approach provides an original treatment to two classical problems: the numerical evaluation of the integrals over the domain A and the enforcement of boundary conditions of the type ui = uion Su. In the absence of body forces (Fi = 0), it will be shown that the calculation of integrals of the type fA .dA can be avoided and that boundary conditions of the type ui = ui on Su can be imposed in the average sense in general and exactly if ui is linear between two contour nodes, which is obviously the case for ui = 0.

  6. Springback Analysis in Sheet Metal Forming of Non-linear Work-Hardening material Under Pure Bending

    Science.gov (United States)

    Lal, Radha Krishna; Dwivedi, Jai Prakash; Bhagat, Manish Kumar; Singh, Virendra Pratap

    2016-09-01

    This paper deals with the springback analysis in sheet metal forming for non-linear work-hardening material under pure bending. Using the deformation theory of plasticity, formulation of the problem and spring back ratio is derived using Ramberg-Osgood stress strain relationship with Tresca and Von-Mises yielding criteria. The results have been representing the effect of different value of Y/E or σo/E ratio, different values of strain hardening index (n), Poisson's ratio (ν) and thickness on springback ratio (R0/Rf). The main aim of this paper is to study the effects of the thickness, Y/E ratio, n and Poisson's ratio in spring back ratio.

  7. Exciton Dynamics and Many Body Interactions in Layered Semiconducting Materials Revealed with Non-linear Coherent Spectroscopy

    Science.gov (United States)

    Dey, Prasenjit

    understanding the basic unexplored science as well as creating technological developments. The dephasing dynamics in semiconductors typically occur in the picosecond to femtosecond timescale, thus the use of ultrafast laser spectroscopy is a potential route to probe such excitonic responses. The focus of this dissertation is two-fold: firstly, to develop the necessary instrumentation to accurately probe the aforementioned parameters and secondly, to explore the quantum dynamics and the underlying many-body interactions in different layered semiconducting materials. A custom-built multidimensional optical non-linear spectrometer was developed in order to perform two-dimensional spectroscopic (2DFT) measurements. The advantages of this technique are multifaceted compared to regular one-dimensional and non-linear incoherent techniques. 2DFT technique is based on an enhanced version of Four wave mixing experiments. This powerful tool is capable of identifying the resonant coupling, probing the coherent pathways, unambiguously extracting the homogeneous linewidth in the presence of inhomogeneity and decomposing a complex spectra into real and imaginary parts. It is not possible to uncover such crucial features by employing one dimensional non-linear technique. Monolayers as well as bulk TMDs and group III-VI bulk layered materials are explored in this dissertation. The exciton quantum dynamics is explored with three pulse four-wave mixing whereas the phase sensitive measurements are obtained by employing two-dimensional Fourier transform spectroscopy. Temperature and excitation density dependent 2DFT experiments unfold the information associated with the many-body interactions in the layered semiconducting samples.

  8. Electro-optical properties, decomposition pathways and the hydrostatic pressure-dependent behaviours of a double-cation hydrogen storage material of Al$_3$Li$_4$(BH$_4$)$_{13}$

    Indian Academy of Sciences (India)

    MEHMET SIMSEK

    2017-09-01

    Electro-optical properties, the decomposition pathways and the pressure-dependent behaviours of Al$_3$Li$_4$(BH$_4$)$_{13}$ have been investigated using a first-principle plane-wave pseudopotential method. Al$_3$Li$_4$(BH$_4$)$_{13}$ is a kindof double-cation borohydride, consisting of distorted tetrahedral anions [Al(BH$_4$)$_4$]$^−$ and cations [Li$_4$(BH$_4$)]$^{3+}$, which obeys the stability criteria of decomposition reactions. Herein, two possible decomposition reactions of the compound are proposed, which release 18 hydrogen molecules (about 12.03 wt%) in the first reaction and 24 hydrogen molecules (about16.04 wt%) in the second reaction. On increasing the pressure on the structure, the lattice parameter, the volume of unitcell, the quasiparticle band gap and also enthalpy of the system decrease nearly monotonically; therefore, the acceptor levelsgradually get filled and the Fermi level shifts upward. Results of computational investigations of the structural, electronic andthermodynamic parameters and their pressure-dependent behaviours indicate that Al$_3$Li$_4$(BH$_4$)$_{13}$ has intriguing properties. Therefore, it would be a very promising material for hydrogen storage technology.

  9. A mixed finite element formulation for a non-linear, transversely isotropic material model for the cardiac tissue.

    Science.gov (United States)

    Thorvaldsen, Tom; Osnes, Harald; Sundnes, Joakim

    2005-12-01

    In this paper we present a mixed finite element method for modeling the passive properties of the myocardium. The passive properties are described by a non-linear, transversely isotropic, hyperelastic material model, and the myocardium is assumed to be almost incompressible. Single-field, pure displacement-based formulations are known to cause numerical difficulties when applied to incompressible or slightly compressible material cases. This paper presents an alternative approach in the form of a mixed formulation, where a separately interpolated pressure field is introduced as a primary unknown in addition to the displacement field. Moreover, a constraint term is included in the formulation to enforce (almost) incompressibility. Numerical results presented in the paper demonstrate the difficulties related to employing a pure displacement-based method, applying a set of physically relevant material parameter values for the cardiac tissue. The same problems are not experienced for the proposed mixed method. We show that the mixed formulation provides reasonable numerical results for compressible as well as nearly incompressible cases, also in situations of large fiber stretches. There is good agreement between the numerical results and the underlying analytical models.

  10. Quantum Modelling of Electro-Optic Modulators

    CERN Document Server

    Capmany, Jose

    2011-01-01

    Many components that are employed in quantum information and communication systems are well known photonic devices encountered in standard optical fiber communication systems, such as optical beamsplitters, waveguide couplers and junctions, electro-optic modulators and optical fiber links. The use of these photonic devices is becoming increasingly important especially in the context of their possible integration either in a specifically designed system or in an already deployed end-to-end fiber link. Whereas the behavior of these devices is well known under the classical regime, in some cases their operation under quantum conditions is less well understood. This paper reviews the salient features of the quantum scattering theory describing both the operation of the electro-optic phase and amplitude modulators in discrete and continuous-mode formalisms. This subject is timely and of importance in light of the increasing utilization of these devices in a variety of systems, including quantum key distribution an...

  11. Parallel High Order Accuracy Methods Applied to Non-Linear Hyperbolic Equations and to Problems in Materials Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Jan Hesthaven

    2012-02-06

    Final report for DOE Contract DE-FG02-98ER25346 entitled Parallel High Order Accuracy Methods Applied to Non-Linear Hyperbolic Equations and to Problems in Materials Sciences. Principal Investigator Jan S. Hesthaven Division of Applied Mathematics Brown University, Box F Providence, RI 02912 Jan.Hesthaven@Brown.edu February 6, 2012 Note: This grant was originally awarded to Professor David Gottlieb and the majority of the work envisioned reflects his original ideas. However, when Prof Gottlieb passed away in December 2008, Professor Hesthaven took over as PI to ensure proper mentoring of students and postdoctoral researchers already involved in the project. This unusual circumstance has naturally impacted the project and its timeline. However, as the report reflects, the planned work has been accomplished and some activities beyond the original scope have been pursued with success. Project overview and main results The effort in this project focuses on the development of high order accurate computational methods for the solution of hyperbolic equations with application to problems with strong shocks. While the methods are general, emphasis is on applications to gas dynamics with strong shocks.

  12. On the potential importance of non-linear viscoelastic material modelling for numerical prediction of brain tissue response: test and application.

    Science.gov (United States)

    Brands, Dave W A; Bovendeerd, Peter H M; Wismans, Jac S H M

    2002-11-01

    In current Finite Element (FE) head models, brain tissue is commonly assumed to display linear viscoelastic material behaviour. However, brain tissue behaves like a non-linear viscoelastic solid for shear strains above 1%. The main objective of this study was to study the effect of non-linear material behaviour on the predicted brain response. We used a non-linear viscoelastic constitutive model, developed on the basis of experimental shear data presented elsewere. First we tested the numerical implementation of the constitutive model by simulating the response of a silicone gel (Sylgard 572 A&B) filled cylindrical cup, subjected to a transient rotational acceleration. The experimental results could be reproduced within 9%. Subsequently, the effect of non-linear material modelling on computed brain response was investigated in an existing three-dimensional head model subjected to an eccentric rotation. At the applied external load strains in the brain were approximately ten times larger than was expected on the basis of published data. This is probably caused by the values of the shear moduli applied in the model. These are at least a factor of ten lower than the ones used in head models in literature but comparable to material data in recent literature. Non-linear material behaviour was found to influence the levels of predicted strains (+20%) and stresses (-11%) but not their temporal and spatial distribution. The pressure response was independent of non-linear material behaviour. In fact it could be predicted by the equilibrium of momentum, and thus it is independent of the choice of the brain constitutive model.

  13. Low Loss Electro-Optic Polymer Based Fast Adaptive Phase Shifters Realized in Silicon Nitride and Oxynitride Waveguide Technology

    Directory of Open Access Journals (Sweden)

    Lars Baudzus

    2016-08-01

    Full Text Available We present a comprehensive study on how to design and fabricate low loss electro-optic phase shifters based on an electro-optic polymer and the silicon nitride and silicon oxynitride waveguide material systems. The loss mechanisms of phase shifters with an electro-optic (EO polymer cladding are analyzed in detail and design solutions to achieve lowest losses are presented. In order to verify the low loss design a proof of concept prototype phase shifter was fabricated, which exhibits an attenuation of 0.8 dB/cm at 1550 nm and an electro-optic efficiency factor of 27%. Furthermore, the potential of this class of phase shifters is evaluated in numerical simulations, from which the optimal design parameters and achievable figures of merit were derived. The presented phase shifter design has its potential for application in fast adaptive multi stage devices for optical signal processing.

  14. Synthesis, photophysical and electro-optical properties of bis-carbazolyl methane based host material for pure-blue phosphorescent OLED

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Byoung-Joon; Yook, Kyoung Soo; Lee, Jun Yeob [Department of Polymer Science and Engineering and Center for Photofunctional Energy Materials, Dankook University, Yongin, Gyeonggi 448-701 (Korea, Republic of); Shin, Seunghan [Chonan R and D Center, KITECH, Chonan, Chungnam 330-825 (Korea, Republic of); Hwang, Seok-Ho, E-mail: bach@dankook.ac.kr [Department of Polymer Science and Engineering and Center for Photofunctional Energy Materials, Dankook University, Yongin, Gyeonggi 448-701 (Korea, Republic of)

    2012-10-15

    A new high triplet-energy host material, 9-(4-(bis(9-ethyl-9H-carbazol-3-yl)methyl)phenyl)-9H-carbazole (bis-CMPC), was synthesized and its device performance of phosphorescent organic light-emitting diode was investigated. This host material showed a high triplet energy ({approx}2.95 eV) and good thermal stability. Highly efficient pure-blue PHOLED was obtained when employing bis-CMPC as the host material and bis((3,5-difluoro-4-cyanophenyl)pyridine) iridium picolinate as the guest material. The maximum external quantum efficiency of the device reached as high as 13.3% with a pure-blue color coordinate of (0.14, 0.21). - Graphical abstract: Highlights: Black-Right-Pointing-Pointer Synthesis of 9-(4-(bis(9-ethyl-9H-carbazol-3-yl)methyl)phenyl)-9H-carbazole. Black-Right-Pointing-Pointer Synthesized host material showed high triplet energy level and thermal stability. Black-Right-Pointing-Pointer Maximum external quantum efficiency of the device as high as 13.3%. Black-Right-Pointing-Pointer The device showed a pure-blue color coordinate of (0.14, 0.21).

  15. Electro-Optical Data Acquisition and Tracking System

    Data.gov (United States)

    Federal Laboratory Consortium — The Electro-Optical Data Acquisition and Tracking System (EDATS) dynamically tracks and measures target signatures. It consists of an instrumentation van integrated...

  16. Electro-optic imaging Fourier transform spectrometer

    Science.gov (United States)

    Chao, Tien-Hsin (Inventor); Znod, Hanying (Inventor)

    2009-01-01

    An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.

  17. Electro-optical detection of charged particles

    CERN Document Server

    Semertzidis, Y K; Kowalski, L A; Kraus, D E; Larsen, R; Lazarus, D M; Magurno, B; Nikas, D; Ozben, C; Srinivasan-Rao, T; Tsang, Thomas

    2000-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO sub 3 crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams.

  18. Theory of Electro-optic Modulation via a Quantum Dot Coupled to a Nano-resonator

    CERN Document Server

    Majumdar, Arka; Faraon, Andrei; Vuckovic, Jelena

    2009-01-01

    In this paper, we analyze the performance of an electro-optic modulator based on a single quantum dot strongly coupled to a nano-resonator, where electrical control of the quantum dot frequency is achieved via quantum confined Stark effect. Using realistic system parameters, we show that modulation speeds of a few tens of GHz are achievable with this system, while the energy per switching operation can be as small as 0.5 fJ. In addition, we study the non-linear distortion, and the effect of pure quantum dot dephasing on the performance of the modulator.

  19. Analysis and Evaluation of Technical Data on the Photochromic and Non-Linear Optical Properties of Materials

    Science.gov (United States)

    1990-06-25

    t ,, A FILE C’D AD-A2 23 855 Sixth Quarterly Technical Report Analysis and Evaluation of Technical Data on the Photochromic and Non-Linear Optical...the back surface of a transparent support and place an absorbing beam dump behind and at an angle to that of the reflective coating . In this

  20. Electro-optic effect and photoelastic effect of feroelectric relaxors

    Science.gov (United States)

    Takeda, Kotaro; Hoshina, Takuya; Takeda, Hiroaki; Tsurumi, Takaaki

    2016-10-01

    To understand the origin of the electro-optic effect (EO-effect) of ferroelectric relaxors, the relationships among the quadratic EO-coefficient, photoelastic coefficient, and electron density were elucidated. The quadratic EO-coefficient is given by the product of the photoelastic and electrostrictive coefficients. Materials consisting of heavy elements normally exhibit high refractive indices and large photoelastic effects, indicating that the photoelastic coefficient increases with electron density of materials. The photoelastic coefficient was calculated as a function of the electron density of materials. The equations derived in this study were experimentally confirmed using lanthanum-added lead-zirconate-titanate (PLZT) transparent ceramics. It was found that the origin of the EO-effect in ferroelectric relaxors was the photoelastic effect coupled with electric-field-induced strain via the piezoelectric and electrostrictive effects.

  1. Electro-optics and lasers in Israel

    Science.gov (United States)

    Van Zwaren, Joesph

    1992-05-01

    With over 3,000 scientists, engineers, and technicians spread out in some 86 companies, and in 10 universities and research institutes, all within less than a 2 hour drive from one another, Israel has no doubt one of the largest concentrations of researchers and skilled manpower in electro-optics and lasers in the world. This report presents an up-to-date picture of the field in Israel, covering the industry, academia and education. The recent wave of Russian immigration is bringing thousands of scientists and tens of thousands of engineers and is expected to make an impact on the field of electro-optics and lasers. A million immigrants from Russia are expected to come between 1990 and 1995. There were 3,700 scientists and 2,800 engineers among the first 200,000 Soviet immigrants. As most of this qualified manpower can not be expected to be absorbed by the existing industry, the Israeli government is actively encouraging local and foreign investors and local and multinational companies to help develop new and expanded high-tech enterprises in Israel. The Ministry of Industry and Trade has embarked upon a broad ranged program for industrial growth and immigrant absorption with the goal of doubling technology-based exports in the next four years. The Ministry of Science and Technology has started a program supporting R&D projects at the different universities for immigrant scientists with the goal of capitalizing on the talents of the newcomers to strengthen academia.

  2. Electro-optic Laser-Sampled Neutron Detector

    Energy Technology Data Exchange (ETDEWEB)

    J. Kenneth Shultis; Douglas McGregor

    2009-11-30

    A new method of detecting radiation which can allow for long distance measurements is being investigated. The device is primarily for neutrons detection althought it could, in principle, be used for gamma ray detection. The neutron detection medium is a solid, transparent, electro-optical material, such as lithium niobate, lithium tantalite, or barium borate. Crystals of these materials act as optical gates to laser light, allowing light to pass through only when a neutron interaction occurs in the crystal. Typical light detection devices, such as CCD cameras or photomultiplier tubes, can be used to signal when light passes through the crystal. The overall goal of the project is to investigate the feasibility of such devices for the detection of neutron radiation and to quantify their capabilities and limitations.

  3. Future electro-optical sensors and processing in urban operations

    NARCIS (Netherlands)

    Grönwall, C.; Schwering, P.B.; Rantakokko, J.; Benoist, K.W.; Kemp, R.A.W.; Steinvall, O.; Letalick, D.; Björkert, S.

    2013-01-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of

  4. Electro-optical techniques for signal conditioning

    Science.gov (United States)

    Helfrich, R. W.

    1981-01-01

    Electro-optical (EO) processing is discussed as a potential alternative to the all-digital approach to signal processing. Nonuniformity compensation can be done by normalizing all the single element detectors outputs in a staring array for both gain and level. Distortion correction can be accomplished with blackbodies, scene statistics or defocused optics. An algorithm used in digital signal conditioning that can be closely approximated by EO techniques is Local Area Brightness Control (LABC). In a digital processor, LABC is performed on a pixel-by-pixel basis, resulting in an enormous amount of calculation. A partially defocused optical system can be used in an EO analog to the digital system. For both nonuniformity compensation and LABC, the EO technique can result in great simplification.

  5. Hybrid Electro-Optically Modulated Microcombs

    CERN Document Server

    Del'Haye, Pascal; Diddams, Scott A

    2012-01-01

    Optical frequency combs based on mode-locked lasers have proven to be invaluable tools for a wide range of applications in precision spectroscopy and metrology. A novel principle of optical frequency comb generation in whispering-gallery mode microresonators ("microcombs") has been developed recently, which represents a promising route towards chip-level integration and out-of-the-lab use of these devices. Presently, two families of microcombs have been demonstrated: combs with electronically detectable mode spacing that can be directly stabilized, and broadband combs with up to octave-spanning spectra but mode spacings beyond electronic detection limits. However, it has not yet been possible to achieve these two key requirements simultaneously, as will be critical for most microcomb applications. Here we present a key step to overcome this problem by interleaving an electro-optic comb with the spectrum from a parametric microcomb. This allows, for the first time, direct control and stabilization of a microco...

  6. Efficient Non Linear Loudspeakers

    DEFF Research Database (Denmark)

    Petersen, Bo R.; Agerkvist, Finn T.

    2006-01-01

    Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...... by changing the voice coil layout. This deliberate non-linear design has the benefit that a smaller amplifier can be used, which has the benefit of reducing system cost as well as reducing power consumption....

  7. Photoinduced electro-optics measurements of biosilica transformation to cristobalite

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Ido [Department of Chemistry and the Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 52900 (Israel); Aluma, Yaniv; Ilan, Micha [Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Kityk, Iwan [Institute of Electronic Systems, Faculty of Electrical Engineering, Czestochowa University, Czestochowa 42-201 (Poland); Mastai, Yitzhak, E-mail: Yitzhak.Mastai@biu.ac.il [Department of Chemistry and the Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan 52900 (Israel)

    2015-03-15

    In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica. - Graphical abstract: The phase transformation of biosilica from marine sponges to Cristobalite under thermal treatment was investigated using photoinduced electro optics measurements. The figure shows the changes of the electro-optic coefficient of cristobalite and biosilica. - Highlights: • We examine phase transformation of biosilica. • We report transition from amorphous biosilica to crystalline Cristobalite. • Biosilica transformation to Cristobalite at temperature of 850 °C. • Biosilica transformation is studied with photoinduced measurements. • We examine changes in the photoinduced linear electro optics properties.

  8. Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching

    Science.gov (United States)

    Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P.

    2017-03-01

    Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986); V. R. Almeida et al., Nature 431, 1081 (2004); and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013)]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.

  9. Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching

    Directory of Open Access Journals (Sweden)

    Mostafa Shalaby

    2017-03-01

    Full Text Available Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986; V. R. Almeida et al., Nature 431, 1081 (2004; and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.

  10. Hydrogen bonding intermolecular effect on electro-optical response of doped 6PCH nematic liquid crystal with some azo dyes

    Science.gov (United States)

    Kiani, S.; Zakerhamidi, M. S.; Tajalli, H.

    2016-05-01

    Previous studies on the electro-optical responses of dye-doped liquid crystal have shown that dopant material have a considerable effect on their electro-optical responses. Despite the studies carried out on electro-optical properties of dye-doped liquid crystal, no attention has been paid to study of the interaction and structural effects in this procedure. In this paper, linear dyes and with similar structure were selected as dopants. The only difference in used dyes is the functional groups in their tails. So, doping of these dyes into liquid crystals determines the influence of interaction type on electro-optical behaviours of the doped systems. Therefore, in this work, two aminoazobenzene ("A-dye": hydrogen bond donor) and dimethyl-aminoazobenzene ("B-dye") dyes with different compositional percentages in liquid crystal host were used. Electro-optical Kerr behaviour, the pre-transition temperature and third order nonlinear susceptibility were investigated. The obtained results effectively revealed that type of interactions between the dye and liquid crystal is determinative of behavioral difference of doped system, compared to pure liquid crystal. Also, pre-transitional behaviour and thereupon Kerr electro-optical responses were affected by formed interactions into doped systems. In other words, it will be shown that addition of any dopants in liquid crystal, regardless of the nature of interactions, cannot cause appropriate electro-optical responses. In fact, type of dye, nature of interactions between dopant and liquid crystalline host as well as concentration of dye are the key factors in selecting the appropriate liquid crystal and dopant dye.

  11. Non-linear and non-local transport processes in heterogeneous media: from long-range correlated percolation to fracture and materials breakdown

    Science.gov (United States)

    Sahimi, Muhammad

    1998-12-01

    We review and discuss recent progress in modelling non-linear and non-local transport processes in heterogeneous media. The non-locality that we consider is caused by long-range correlations that either exist in the morphology of the media, or are caused by the transport processes themselves. The interplay between the non-linearity and non-locality is discussed in depth with the aim of establishing that, often non-linearity and non-locality are “two sides of the same coin”, such that one may have no meaning without the presence of the other one. First, we discuss linear and scalar, but non-local transport processes and, in particular, consider those in percolation systems with long-range correlations. It appears that there are significant differences between percolative transport processes in which the long-range correlations (or the covariance function) decrease with the distance r between two points, and those in which they increase as r does. Application of this problem to flow and transport in geological formations is discussed. We then consider linear vector percolation, one type of which, the rigidity percolation, provides an example of a non-local vector transport in heterogeneous media. Applications of vector percolation to modelling elastic properties of glasses, composite solids and rock, mechanical and viscoelastic properties of polymers, and vibrations and dynamical properties of heterogeneous materials are discussed. Non-linear and non-local scalar transport processes are discussed next, including various breakdown phenomena in disordered composites, power-law transport, piecewise linear transport characterized by a threshold, and non-linear processes that arise as a result of imposing a large external potential gradient on a heterogeneous medium. Their relevance to flow of non-Newtonian fluids in porous media, to electrical currents and dielectric breakdown in composite solids and doped polycrystalline semiconductors, and several other problems is

  12. Efficient Non Linear Loudspeakers

    DEFF Research Database (Denmark)

    Petersen, Bo R.; Agerkvist, Finn T.

    2006-01-01

    Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...... by changing the voice coil layout. This deliberate non-linear design has the benefit that a smaller amplifier can be used, which has the benefit of reducing system cost as well as reducing power consumption.......Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...

  13. Silicon electro-optic modulator with high-permittivity gate dielectric layer

    Institute of Scientific and Technical Information of China (English)

    Mengxia Zhu; Zhiping Zhou; Dingshan Gao

    2009-01-01

    A high-permittivity (high-k) material is applied as the gate dielectric layer in a silicon metal-oxidesemiconductor (MOS) capacitor to form a special electro-optic (EO) modulator.Both induced charge density and modulation efficiency in the proposed modulator are improved due to the special structure design and the application of the high-k material.The device has an ultra-compact dimension of 691 μm in length.

  14. Study of electro-optic effect in asymmetrically ramped AlInGaAs multiple quantum well structures

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq, Muhammad Usman; Peters, Frank H.; Corbett, Brian [Tyndall National Institute, Lee Maltings, Cork (Ireland); Department of Physics, University College Cork, Cork (Ireland); O' Callaghan, James; Roycroft, Brendan; Thomas, Kevin; Pelucchi, Emanuele [Tyndall National Institute, Lee Maltings, Cork (Ireland)

    2016-04-15

    We investigate the electro-optic properties of two oppositely ramped asymmetric quantum well structures in the AlInGaAs material system. The grading of the bandgap in the quantum wells has been achieved by changing the ratio of Al to Ga in the quaternary alloy during the epitaxial growth. The surface normal photo-response and the Fabry-Perot fringe shift in straight waveguides are compared for both structures as a function of applied voltage at 1550 nm for TE-polarized light. The measurements show a change in the refractive index due to a red shift of the excitonic resonances due to the quantum-confined Stark effect. The 10 quantum well structure with a ramp up of the bandgap in the growth direction leads to the figure of merit of the voltage for a π phase shift, V{sub π} by length, L, V{sub π} x L, of 6 as compared to 7 V . mm in the structure with a ramp in opposite direction. Further investigations show that the reduction in V{sub π} is due to increased absorption at high reverse bias which induces a non-linear phase change. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Enhanced Kerr electro-optic nonlinearity through cascaded Pockels effects

    CERN Document Server

    Li, Guang-Zhen; Jiang, Hao-Wei; Chen, Xian-Feng

    2015-01-01

    We demonstrated a large enhancement of Kerr electro-optic nonlinearity through cascaded Pockels effects in a domain inversion ferroelectric crystal. We designed a structure that can implement the cascaded Pockels effects and second-harmonic generation simultaneously. The energy coupling between the fundamental lights of different polarizations led to a large nonlinear phase shift, and thus an effective electro-optic nonlinear refractive index. The effective nonlinearity can be either positive or negative, causing the second-harmonic spectra to move towards the coupling center, which in turn, offered us a way to measure the effective electro-optic nonlinear refractive index. The corresponding enhanced Kerr electro-optic nonlinearity is more than three orders of magnitude higher than the intrinsic value. These results open a door to manipulate the nonlinear phase by applying external electric field instead of light intensity in noncentrosymmetric crystals.

  16. Photoinduced electro-optics measurements of biosilica transformation to cristobalite

    Science.gov (United States)

    Fuchs, Ido; Aluma, Yaniv; Ilan, Micha; Kityk, Iwan; Mastai, Yitzhak

    2015-03-01

    In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica.

  17. Electro-Optic Imaging Fourier Transform Spectral Polarimeter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Boulder Nonlinear Systems, Inc. (BNS) proposes to develop an Electro-Optic Imaging Fourier Transform Spectral Polarimeter (E-O IFTSP). The polarimetric system is...

  18. High-Speed Electro-Optic Modulator Integrated with Graphene-Boron Nitride Heterostructure and Photonic Crystal Nanocavity

    CERN Document Server

    Gao, Yuanda; Gan, Xuetao; Li, Luozhou; Peng, Cheng; Meric, Inanc; Wang, Lei; Szep, Attila; Walker, Dennis; Hone, James; Englund, Dirk

    2014-01-01

    Nanoscale and power-efficient electro-optic (EO) modulators are essential components for optical interconnects that are beginning to replace electrical wiring for intra- and inter-chip communications. Silicon-based EO modulators show sufficient figures of merits regarding device footprint, speed, power consumption and modulation depth. However, the weak electro-optic effect of silicon still sets a technical bottleneck for these devices, motivating the development of modulators based on new materials. Graphene, a two-dimensional carbon allotrope, has emerged as an alternative active material for optoelectronic applications owing to its exceptional optical and electronic properties. Here, we demonstrate a high-speed graphene electro-optic modulator based on a graphene-boron nitride (BN) heterostructure integrated with a silicon photonic crystal nanocavity. Strongly enhanced light-matter interaction of graphene in a submicron cavity enables efficient electrical tuning of the cavity reflection. We observe a modul...

  19. Determining large deflections in rectangular combined loaded cantilever beams made of non-linear Ludwick type material by means of different arc length assumptions

    Indian Academy of Sciences (India)

    Ibrahim Eren

    2008-02-01

    In this study, large deflection of cantilever beams of Ludwick type material subjected to a combined loading consisting of a uniformly distributed load and one vertical concentrated load at the free end was investigated. In calculations, both material and geometrical non-linearity have been considered. Horizontal and vertical deflections magnitudes were calculated throughout Euler–Bernoulli curvature-moment relationship assuming different arc lengths. Vertical deflections were calculated by using Runge–Kutta method. More simple and easily understandable results have been obtained compared to the previous studies about the issue and compatible values have been obtained for most of the compared values.

  20. Terahertz wave electro-optic measurements with optical spectral filtering

    Energy Technology Data Exchange (ETDEWEB)

    Ilyakov, I. E., E-mail: igor-ilyakov@mail.ru; Shishkin, B. V. [Institute of Applied Physic RAS, Nizhny Novgorod 603950 (Russian Federation); Kitaeva, G. Kh. [Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Akhmedzhanov, R. A. [Institute of Applied Physic RAS, Nizhny Novgorod 603950 (Russian Federation); N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950 (Russian Federation)

    2015-03-23

    We propose electro-optic detection techniques based on variations of the laser pulse spectrum induced during pulse co-propagation with terahertz wave radiation in a nonlinear crystal. Quantitative comparison with two other detection methods is made. Substantial improvement of the sensitivity compared to the standard electro-optic detection technique (at high frequencies) and to the previously shown technique based on laser pulse energy changes is demonstrated in experiment.

  1. PREFACE: Colloidal and molecular electro-optics Colloidal and molecular electro-optics

    Science.gov (United States)

    Palberg, Thomas; Löwen, Hartmut

    2010-12-01

    The Kerr effect, also known as the quadratic electro-optic effect, was discovered more than a hundred years ago by John Kerr, a Scottish physicist [1]. It describes the change in the refractive index of a material in response to an applied electric field. Around 1950 its application swayed from simple to complex fluids. A strong contribution was made through a number of seminal papers by the French polymer scientist H Benoit [2-4]. These and others initiated wide interest from researchers working on macromolecular solutions or colloidal dispersions. Experimental activities were further boosted by the advent of the laser and theoretical approaches strongly drew from growing computer power. Use of AC or pulsed field techniques, as well as of inhomogeneous fields, including laser tweezers, studies of electrophoretic, dielectrophoretic, electro-osmotic and other types of motion by advanced optical methods and combinations with other external fields have had the greatest impact on our understanding of the electric field induced optical properties of soft matter systems. Today the field has matured and its techniques are broadly employed as versatile tools with applications ranging from biological systems to electronic ink. Fundamental interest still continues but more and more side branches have evolved fruitfully. This collection of papers was, therefore, brought together to take a fresh look at this traditional field. Further, we are to celebrate 35 years of a successful conference series, ELOPTO, with the last one held at Waldthausen Castle hosted by the Johannes Gutenberg University, MainzNote1 and the DFG Collaborative Research Centre TR6 'Physics of colloidal dispersions in external fields'Note2. In this issue we have collected the articles of some of the leading experts in the area, well garnished with novel approaches and clever ideas by younger colleagues. With our selection we hope to cover a representative spectrum of the ongoing research, catch the most

  2. Highly Sensitive Electro-Optic Modulators

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, Peter S [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestation of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.

  3. Electro-optics of perovskite solar cells

    Science.gov (United States)

    Lin, Qianqian; Armin, Ardalan; Nagiri, Ravi Chandra Raju; Burn, Paul L.; Meredith, Paul

    2015-02-01

    Organohalide-perovskite solar cells have emerged as a leading next-generation photovoltaic technology. However, despite surging efficiencies, many questions remain unanswered regarding the mechanisms of operation. Here we report a detailed study of the electro-optics of efficient CH3NH3PbI3-perovskite-only planar devices. We report the dielectric constants over a large frequency range. Importantly, we found the real part of the static dielectric constant to be ∼70, from which we estimate the exciton-binding energy to be of order 2 meV, which strongly indicates a non-excitonic mechanism. Also, Jonscher's Law behaviour was consistent with the perovskite having ionic character. Accurate knowledge of the cell's optical constants allowed improved modelling and design, and using this information we fabricated an optimized device with an efficiency of 16.5%. The optimized devices have ∼100% spectrally flat internal quantum efficiencies and minimal bimolecular recombination. These findings establish systematic design rules to achieve silicon-like efficiencies in simple perovskite solar cells.

  4. Non-centrosymmetric crystals of new N-benzylideneaniline derivatives as potential materials for non-linear optics.

    Science.gov (United States)

    Souza, Talita Evelyn; Rosa, Iara Maria Landre; Legendre, Alexandre Oliveira; Paschoal, Diego; Maia, Lauro J Q; Dos Santos, Hélio F; Matins, Felipe Terra; Doriguetto, Antonio Carlos

    2015-08-01

    Three new N-benzylideneaniline derivatives [p-nitrobenzylidene-p-phenylamineaniline (I), 2,4-dinitrobenzylidene-p-phenylamineaniline (II) and p-dinitrobenzylidene-p-diethylamineaniline (III)] containing electron-push-pull groups have been prepared. They present a planar N-benzylideneaniline core and neighbouring functional atoms, which are related through an efficient intramolecular charge transfer (CT). Two of the derivatives crystallize in non-centrosymmetric space groups, a necessary condition for non-linear optical (NLO) responses. The NLO properties were calculated for the molecular conformations determined by single-crystal X-ray diffraction as well as for the four molecules packed into each corresponding unit cell, using a quantum-chemical method at the cam-B3LYP/NLO-V level of theory. As expected from antiparallel face-to-face stacking through centrosymmetry, the main NLO descriptors - namely, the first hyperpolarizability (βtot) and its projection on the dipole moment direction (βvec) - are almost zero for the tetramer of derivative III. Interestingly, the calculated first hyperpolarizability decreases in the non-centrosymmetric unit-cell content of derivative II when compared to its single molecule, which may be related to its molecular pillaring, similar to that observed in derivative III. On the other hand, a desirable magnification of the NLO properties was found for packed units of derivative I, which may be a consequence of its parallel face-to-tail stacking with the CT vectors of all molecules pointing in the same direction. Moreover, the CT vector of compound I makes an angle of θ = 33.6° with its crystal polar axis, resulting in a higher-order parameter (cos(3)θ = 0.6) compared with the other derivatives. This is in line with the higher macroscopic second-order NLO response predicted for derivative I, βtot = 120.4 × 10(-30) e.s.u.

  5. [Progress of electro-optic polymer in the field of generation and detection of Terahertz waves by all-optical technique].

    Science.gov (United States)

    Wang, Xuan; Jiang, Qiang; Wang, Yue; Zhang, Wen-long; Li, Zhi-yuan

    2014-08-01

    Research on and development of the high amplitude, broadband terahertz system based on ultra-short pulse, low-power laser system is a hot spot in the field of terahertz. So far, for all the reported THz bandwidths broader than 10 THz, there always exist strong dispersion and absorption gaps associated with the lattice resonance in either the photoconductive materials or crystalline EO materials. If such THz sources and detectors are employed in spectroscopic studies, spectral information in these gaps cannot be extracted. One of the advantages of using amorphous electro-optic polymer films as THz emitters and sensors is that there is no dispersion or absorption resulting from the lattice resonance effect, making a gap-free THz spectrum possible. Another advantage of electro-optic polymer films is the ease of fabrication and handling, in contrast to the extremely thin crystalline electro-optic materials used for existing broadband THz system. In addition, we can engineer the electro-optic polymeric materials to achieve small phase mismatch and high electro-optic coefficients such that brightness and broad bandwidth of THz radiation can be obtained. In this thesis a theoretical description of electro-optic effect based on electro-optic polymer and the second- order nonlinear chromophores synthesis is reviewed. In the past 20 years, progress in electro-optic polymer in the field of generating and detecting terahertz radiation by all-optical techniques is summarized, including the terahertzs systems based on copolymer and the guest-host polymer induced by Titanium doped sapphire femtosecond laser and based on the guest-host polymer at communication wavelengths.

  6. Double lens device for tunable harmonic generation of laser beams in KBBF/RBBF crystals or other non-linear optic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Adam

    2017-08-22

    A method and apparatus to generate harmonically related laser wavelengths includes a pair of lenses at opposing faces of a non-linear optical material. The lenses are configured to promote incoming and outgoing beams to be normal to each outer lens surface over a range of acceptance angles of the incoming laser beam. This reduces reflection loss for higher efficiency operation. Additionally, the lenses allow a wider range of wavelengths for lasers for more universal application. Examples of the lenses include plano-cylindrical and plano-spherical form factors.

  7. Ultrabroadband Electro-Optic Modulator Based on Hybrid Silicon-Polymer Dual Vertical Slot Waveguide

    Directory of Open Access Journals (Sweden)

    Shouyuan Shi

    2011-01-01

    Full Text Available We present a novel hybrid silicon-polymer dual slot waveguide for high speed and ultra-low driving voltage electro-optic (EO modulation. The proposed design utilizes the unique properties of ferroelectric materials such as LiNbO3 to achieve dual RF and optical modes within a low index nanoslot. The tight mode concentration and overlap in the slot allow the infiltrated organic EO polymers to experience enhanced nonlinear interaction with the applied electric field. Half-wavelength voltage-length product and electro-optic response are rigorously simulated to characterize the proposed design, which reveals ultrabroadband operation, up to 250 GHz, and subvolt driving voltage for a 1 cm long modulator.

  8. Effective electro-optical modulation with high extinction ratio by a graphene-silicon microring resonator

    DEFF Research Database (Denmark)

    Ding, Yunhong; Zhu, Xiaolong; Xiao, Sanshui

    2015-01-01

    comprehensively study the interaction between graphene and a microring resonator, and its influence on the optical modulation depth. We demonstrate graphene-silicon microring devices showing a high modulation depth of 12.5 dB with a relatively low bias voltage of 8.8 V. On-off electro-optical switching......Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultra-large absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of the Fermi level enables electro-optical...... modulation, optical-optical switching, and other optoelectronics applications. However, achieving a high modulation depth remains a challenge because of the modest graphene-light interaction in the graphene-silicon devices, typically, utilizing only a monolayer or few layers of graphene. Here, we...

  9. Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

    Directory of Open Access Journals (Sweden)

    John F. Whitaker

    2011-01-01

    Full Text Available In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms of optical alignment, spatial resolution, and especially, a low degree of field invasiveness. We propose and review five distinct types of fiber-coupled electro-optic sensor probes. The design guidelines for each probe type and their performances in absolute electric-field measurements are compared and summarized.

  10. High-frequency electro-optic measurement of strained silicon racetrack resonators.

    Science.gov (United States)

    Borghi, M; Mancinelli, M; Merget, F; Witzens, J; Bernard, M; Ghulinyan, M; Pucker, G; Pavesi, L

    2015-11-15

    The observation of the electro-optic effect in strained silicon waveguides has been considered a direct manifestation of an induced χ(2) nonlinearity in the material. In this work, we perform high-frequency measurements on strained silicon racetrack resonators. Strain is controlled by a mechanical deformation of the waveguide. It is shown that any optical modulation vanishes, independent of the applied strain, when the applied voltage varies much faster than the carrier effective lifetime and that the DC modulation is also largely independent of the applied strain. This demonstrates that plasma carrier dispersion is responsible for the observed electro-optic effect. After normalizing out free-carrier effects, our results set an upper limit of (8±3) pm/V to the induced high-speed effective χeff,zzz(2) tensor element at an applied stress of -0.5 GPa. This upper limit is about 1 order of magnitude lower than previously reported values for static electro-optic measurements.

  11. Optical and Electro-Optical Instrumentation (Guest Editorial

    Directory of Open Access Journals (Sweden)

    S. S. Negi

    2013-12-01

    Full Text Available Importance of Optical and Electro-Optical Instrumentation is growing by leaps and bounds in the modern day battlefield.  Night vision devices both image intensifier (II Tube based and thermal imagers (TIs are true force multipliers as they allow weapons and equipments to be used during day and night in fair and bad weather conditions. Growing trends in the thermal imaging area are mega pixels arrays with smaller pixel size, active and passive imaging at the focal plane, new detector materials operating at elevated temperature, dual color detectors, advanced signal and image processing, sensor and image fusion and automatic target recognition capability. With sufficient exploitations of these devices on ground, worldwide focus is towards the militarization of space by deploying multi / hyper spectral imagers for better target discrimination.  Low power non-lethal laser instrumentation is also emerging as another key area to fight a battle taking the shapes of Laser range finders, gap measuring devices, precision guided munitions, and laser proximity fuzes. The key trends in laser instrumentation area are eye-safe lasers, laser diodes arrays, diode pumped laser designators, high power lasers with  adaptive beam-shaping, sensor fuzed seekers and 3-D laser imaging.Defence Science Journal, 2013, 63(6, pp.543-544, DOI:http://dx.doi.org/10.14429/dsj.63.5746

  12. A high average power electro-optic switch using KTP

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, C.A.; Cook, W.M.; Velsko, S.P.

    1994-04-01

    High damage threshold, high thermal conductivity, and small thermo-optic coefficients make KTiOPO{sub 4} (KTP) an attractive material for use in a high average power Q-switch. However, electro-chromic damage and refractive index homogeneity have prevented the utilization of KTP in such a device in the past. This work shows that electro-chromic damage is effectively suppressed using capacitive coupling, and a KTP crystal can be Q-switched for 1.5 {times} 10{sup 9} shots without any detectable electro-chromic damage. In addition, KTP with the high uniformity and large aperture size needed for a KTP electro-optic Q-switch can be obtained from flux crystals grown at constant temperature. A thermally compensated, dual crystal KTP Q-switch, which successfully produced 50 mJ pulses with a pulse width of 8 ns (FWHM), has been constructed. In addition, in off-line testing the Q-switch showed less than 7% depolarization at an average power loading of 3.2 kW/cm{sup 2}.

  13. A Numerical Approach for Non-Linear Moisture Flow in Porous Materials with Account to Sorption Hysteresis

    DEFF Research Database (Denmark)

    Johannesson, Björn; Nyman, U.

    2010-01-01

    A numerical approach for moisture transport in porous materials like concrete is presented. The model considers mass balance equations for the vapour phase and the water phase in the material together with constitutive equations for the mass flows and for the exchange of mass between the two phases....... History-dependent sorption behaviour is introduced by considering scanning curves between the bounding desorption and absorption curves. The method, therefore, makes it possible to calculate equilibrium water contents for arbitrary relative humidity variations at every material point considered......-Raphson equilibrium iteration scheme within the time steps. Examples are presented illustrating the performance and potential of the model. Two different types of measurements on moisture content profiles in concrete are used to verify the relevance of the novel proposed model for moisture transport and sorption...

  14. Embodiment of Learning in Electro-Optical Signal Processors

    Science.gov (United States)

    Hermans, Michiel; Antonik, Piotr; Haelterman, Marc; Massar, Serge

    2016-09-01

    Delay-coupled electro-optical systems have received much attention for their dynamical properties and their potential use in signal processing. In particular it has recently been demonstrated, using the artificial intelligence algorithm known as reservoir computing, that photonic implementations of such systems solve complex tasks such as speech recognition. Here we show how the backpropagation algorithm can be physically implemented on the same electro-optical delay-coupled architecture used for computation with only minor changes to the original design. We find that, compared when the backpropagation algorithm is not used, the error rate of the resulting computing device, evaluated on three benchmark tasks, decreases considerably. This demonstrates that electro-optical analog computers can embody a large part of their own training process, allowing them to be applied to new, more difficult tasks.

  15. Non-Linear Optical Phenomena in Detecting Materials as a Possibility for Fast Timing in Detectors of Ionizing Radiation

    CERN Document Server

    Korjik, M. V.; Buganov, O.; Fedorov, A. A.; Emelianchik, I.; Griesmayer, E.; Mechinsky, V.; Nargelas, S.; Sidletskiy, O.; Tamulaitis, G.; Tikhomirov, S. N.; Vaitkevicius, A.

    2016-01-01

    The time resolution of the detectors currently in use is limited by 50-70 ps due to the spontaneous processes involved in the development of the response signal, which forms after the relaxation of carriers generated during the interaction. In this study, we investigate the feasibility of exploiting sub-picosecond phenomena occurring after the interaction of scintillator material with ionizing radiation by probing the material with ultra-short laser pulses. One of the phenomena is the elastic polarization due to the local lattice distortion caused by the displacement of electrons and holes generated by ionization. The key feature of the elastic polarization is its short response time, which makes it prospective for using as an optically detectable time mark. The nonlinear optical absorption of femtosecond light pulses of appropriate wavelength is demonstrated to be a prospective tool to form the mark. This study was aimed at searching for inorganic crystalline media combining scintillation properties and non-...

  16. Building electro-optical systems making it all work

    CERN Document Server

    Hobbs, Philip C D

    2009-01-01

    Praise for the First Edition ""Now a new laboratory bible for optics researchers has joined the list: it is Phil Hobbs's Building Electro-Optical Systems: Making It All Work.""-Tony Siegman, Optics & Photonics News Building a modern electro-optical instrument may be the most interdisciplinary job in all of engineering. Be it a DVD player or a laboratory one-off, it involves physics, electrical engineering, optical engineering, and computer science interacting in complex ways. This book will help all kinds of technical people sort through the complexit

  17. Fast switchable electro-optic radial polarization retarder

    CERN Document Server

    Lim, B C; Lai, W J; Hong, M H

    2008-01-01

    A fast, switchable electro-optic radial polarization retarder (EO-RPR) fabricated using the electro-optic ceramic PMN-PT is presented. This EO-RPR is useful for fast, switchable generation of pure cylindrical vector beam. When used together with a pair of half-wave plates, the EO-RPR can change circularly polarized light into any cylindrical vector beam of interest such as radially or azimuthally polarized light. Radially and azimuthally polarized light with purities greater than 95% are generated experimentally. The advantages of using EO-RPR include fast response times, low driving voltage and transparency in a wide spectral range (500 -7000 nm).

  18. Electro-optical properties of tetragonal KNbO3

    Indian Academy of Sciences (India)

    P U Sastry

    2007-06-01

    Linear electro-optical tensor coefficients and optical susceptibility of tetragonal KNbO3 are calculated using a formalism based on bond charge theory. Results are in close agreement with the experimental data. The covalent Nb–O bonding network comprising the distorted NbO6 octahedral groups in the structure is found to be a major contributor to the electro-optic coefficients making these groups more sensitive to these properties than the KO12 groups. The orientations of the chemical bonds play an important role in determining these properties.

  19. Time-Resolved Terahertz Spectroscopy with Free-Space Electro-Optic Sampling

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang-Liang; ZHAO Guo-Zhong; ZHONG Hua; HU Ying; ZHANG Cun-Lin

    2004-01-01

    @@ We present a time-resolved ultrafast measurement in terahertz (THz) frequency region by means of the free-space electro-optic sampling. The fast delay scan technique is used to suppress the noise with low frequency and to improve the signal-to-noise ratio of the system. The transmission spectra of different materials are obtained.The optical properties of these materials in a THz region are shown. The broadening of spectrum and chirping phenomena are illustrated. We find that polystyrene is an excellent material for the THz application.

  20. External Electro-optic Sampling Utilizing an Asymmetric Fabry-Pérot Film of Poled Electro-optical Polymer

    Institute of Scientific and Technical Information of China (English)

    陈开鑫; 杨罕; 张大明; 张红波; 衣茂斌

    2001-01-01

    External electro-optic sampling has been first demonstrated using a poled electro-optical polymer asymmetricFabry-Pérot film, placed freely on the indium-tin oxide coplanar waveguide transmission line and used as anelectro-optic probe tip. Only one laser beam is required due to the fact that the asymmetric Fabry-Pérot film isutilized to convert the phase modulation to amplitude modulation. A 1.2 GHz microwave signal is sampled, andthe voltage sensitivity of about 2 m V/Hz is obtained. The results are promising for technical applications inhigh-speed electronic devices and monolithic microwave integrated circuits research.

  1. Application of electro-optic sampling in FEL diagnostics

    NARCIS (Netherlands)

    Yan, X.; MacLeod, A. M.; Gillespie, W. A.; Knippels, G.M.H.; Oepts, D.; van der Meer, A. F. G.

    2001-01-01

    The electro-optic sampling technique has been used for the full characterization (both amplitude and phase) of freely propagating pulsed electromagnetic radiation (such as FEL pulses, transition radiation) and for the quasistatic electric field of relativistic electron bunches. Measurements of the e

  2. Asymmetric Threat Assessment Using Electro-Optical Image Systems

    NARCIS (Netherlands)

    Schwering, P.B.W.; Schutte, K.

    2010-01-01

    Asymmetric threat assessment from military platforms, including early detection and classification by electro-optical means, is a complicated matter. These threats can be for instance explosives-packed rubber boats, minecarrying swimmers and divers in a marine environment or terrorists, improvised e

  3. Algorithm for the treatment of the material plastic anisotropy and its introduction into a non-linear structural analysis code (NOSA)

    Energy Technology Data Exchange (ETDEWEB)

    Toselli, G. [ENEA, Centro Ricerche Ezio Clementel, Bologna, (Italy). Dipt. Innovazione; Mirco, A. M. [Bologna Univ., Bologna (Italy). Dipt. di Matematica

    1999-07-01

    In this technical report the thesis of doctor's degree in Mathematics of A.M. Mirco is reported; it has been developed at ENEA research centre 'E. Clementel' in Bologna (Italy) in the frame of a collaboration between the section MACO (Applied Physics Division - Innovation Department) of ENEA at Bologna and the Department of Mathematics of the mathematical, physical and natural sciences faculty of Bologna University. Substantially, studies and research work, developed in these last years at MACO section, are here presented; they have led to the development of a constitutive model, based on Hill potential theory, for the treatment, in plastic field, of metal material anisotropy induced by previous workings and to the construction of the corresponding FEM algorithm for the non-linear structural analysis NOSA, oriented in particular to the numerical simulation of metal forming. Subsequently, an algorithm extension (proper object of the thesis), which has given, beyond a more rigorous formalization, also significant improvements. [Italian] In questo rapporto tecnico viene riportata la tesi di laurea in matematica di A. M. Mirco, tesi svolta presso il centro ricerche E. Clementel dell'ENEA di Bologna nell'ambito di un accordo di collaborazione fra la sezione MACO (Divisione Fisica Applicata - Dipartimento di Innovazione) dell'ENEA di Bologna ed il Dipartimento di matematica della facolta' di scienze matematiche, fisiche e naturali dell'universita' degli studi di Bologna. Sostanzialmente, vengono presentati gli studi ed il lavoro di ricerca, svolti in questi ultimi anni presso la sezione MACO, che hanno portato allo sviluppo di un modello costitutivo, basato sulla teoria del potenziale di Hill, per il trattamento in campo plastico, dell'anisotropia indotta da lavorazioni precedenti per un materiale metallico ed alla costruzione del corrispondente algoritmo basato sul metodo degli elementi finiti per il codice di analisi

  4. Automatic Laser Glare Suppression in Electro-Optical Sensors

    Directory of Open Access Journals (Sweden)

    Gunnar Ritt

    2015-01-01

    Full Text Available Progress in laser technology has led to very compact but nevertheless powerful laser sources. In the visible and near infrared spectral region, lasers of any wavelength can be purchased. Continuous wave laser sources pose an especially serious threat to the human eye and electro-optical sensors due to their high proliferation and easy availability. The manifold of available wavelengths cannot be covered by conventional safety measures like absorption or interference filters. We present a protection concept for electro-optical sensors to suppress dazzling in the visible spectral region. The key element of the concept is the use of a digital micromirror device (DMD in combination with wavelength multiplexing. This approach allows selective spectral filtering in defined regions of interest in the scene. The system offers the possibility of automatic attenuation of dazzling laser radiation.

  5. Laser pulse spectral shaping based on electro-optic modulation

    Institute of Scientific and Technical Information of China (English)

    Yanhai Wang; Jiangfeng Wang; You'en Jiang; Yan Bao; Xuechun Li; Zunqi Lin

    2008-01-01

    A new spectrum shaping method, based on electro-optic modulation, to alleviate gain narrowing in chirped pulse amplification (CPA) system, is described and numerically simulated. Near-Fourier transform-limited seed laser pulse is chirped linearly through optical stretcher. Then the chirped laser pulse is coupled into integrated waveguide electro-optic modulator driven by an aperture-coupled-stripline (ACSL) electricalwaveform generator, and the pulse shape and amplitude are shaped in time domain. Because of the directrelationship between frequency interval and time interval of the linearly chirped pulse, the laser pulse spectrum is shaped correspondingly. Spectrum-shaping examples are modeled numerically to determine the spectral resolution of this technique. The phase error introduced in this method is also discussed.

  6. Electro-optic techniques in electron beam diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    van Tilborg, Jeroen; Toth, Csaba; Matlis, Nicholas; Plateau, Guillaume; Leemans, Wim

    2011-06-17

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  7. Precursor polymer approach towards functional conjugated polymer networks and ultrathin film electro-optical applications

    Science.gov (United States)

    Taranekar, Prasad

    Conjugated polymers are organic semiconductors which are of interest to a wide variety of optical, electronic, opto-electronic, and sensory applications; including light emitting diodes, thin film transistors, photovoltaic cells, and chemical sensors. While conducting polymers have some similarities to conventional polymeric materials, it is clearly the extensive main chain pi-conjugated structure and its implicit electro-optical properties that make it distinct. The same structure, however, gives it "chain stiffness" that affects its physical behavior. As a direct consequence of this, virtually all unsubstituted conducting polymers are found to be intractable and insoluble. This dissertation details the issue of tailoring the electro-optical properties and processability of conjugated polymers via a novel "precursor polymer approach". In this approach, electroactive side group units of either similar or different kind are tethered to a polymeric backbone. This combination determines the eventual electro-optical and electrochemical properties of these polymers including their ability to form ultrathin films. Thus, the desired macroscopic property is transformed by designing new precursor polymer structures, manipulating polymer-based compositions and blends, and the exploration and exploitation of their electrochemical processing conditions. In Chapters 2, 3, and 4, we have used single or binary electroactive compositions of species such as pyrrole, thiophene, carbazole and terthiophene are tethered to a linear polymeric backbone. Besides, the linear approach, in Chapters 5 and 6, we have also explored the use of generational dendrimers as backbone with carbazole units attached as peripheral electroactive groups. These precursor polymers were then subjected to electrochemical cross-linking to generate high optical quality ultrathin films on a conducting substrate such as indium tin oxide (ITO) or Au surfaces. The reaction of such electroactive species inimically

  8. Electro-optic product design for manufacture: where next?

    Science.gov (United States)

    Barr, John R. M.; MacDonald, M.; Jeffery, G.; Troughton, M.

    2016-10-01

    Manufacturing of electro-optic products for military environments poses a large number of apparently intractable and mutually contradictory problems. The ability to successfully engage in this area presents an intellectual challenge of a high order. The Advanced Targeting Sector of Leonardo's Airborne and Space Systems Division, based in Edinburgh, has developed a successful range of electro-optic products and transitioned these into a volume, and high value, manufacturing environment. As products cycle through the design process, there has been strong feedback from users, suppliers, and most importantly from our manufacturing organization, that has driven evolution of our design practices. It is fair to say that recent pointer trackers and lasers bear little resemblance to those designed and built 10 years ago. Looking ahead, this process will only continue. There are interesting technologies that will drive improvements in manufacturability, reliability and usability of electro-optic products. Examples might include freeform optics, additive manufacture of metal components, and laser welding of optics to metals, to name but a few. These have uses across our product portfolio and, when sufficiently matured, will have a major impact on the product quality and reliability

  9. Polymer waveguide systems for nonlinear and electro-optic applications

    Science.gov (United States)

    Pantelis, Philip; Hill, Julian R.; Kashyap, Raman

    1991-12-01

    Waveguides with photochromic or electro-optic properties have been fabricated by a new technique using spin coating of polymers, or guest/host-polymer systems, on to grooves etched in an indium phosphide wafer. Monomoded waveguides at 633 nm, and at 1320 and 1550 nm (wavelengths of telecommunications interest) have been fabricated. These guides have good quality cleaved ends which allow efficient coupling of light from monomoded standard lensed silica fibers. An example of an electro-optic application is given in the form of a phase modulator. This device uses a side-chain polymer as the waveguide core that develops linear electro-optic properties following an electric field alignment process. It was found to have a switching voltage of 30 V, for a (pi) phase change, and had a total insertion loss of 9.4 dB. Waveguides with photochromic properties have also been produced using Aberchrome 670 (a commercially available fulgide) as a guest in a poly(methyl methacrylate) polymer host. Refractive index, optical loss, photochromic activity, and film forming properties of differing concentrations of guest (up to 20% concentration by weight) have been measured and are reported.

  10. 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.

  11. On-chip microwave-to-optical quantum coherent converter based on a superconducting resonator coupled to an electro-optic microresonator

    Science.gov (United States)

    Javerzac-Galy, C.; Plekhanov, K.; Bernier, N. R.; Toth, L. D.; Feofanov, A. K.; Kippenberg, T. J.

    2016-11-01

    We propose a device architecture capable of direct quantum coherent electro-optical conversion of microwave-to-optical photons. The hybrid system consists of a planar superconducting microwave circuit coupled to an integrated whispering-gallery-mode microresonator made from an electro-optical material. We show that by exploiting the large vacuum electric field of the planar microwave resonator, electro-optical (vacuum) coupling strengths g0 as large as ˜2 π O (10 -100 ) kHz are achievable with currently available technology—a more than 3 orders of magnitude improvement over prior designs and realizations. Operating at millikelvin temperatures, such a converter would enable high-efficiency conversion of microwave-to-optical photons. We analyze the added noise and show that maximum quantum coherent conversion efficiency is achieved for a multiphoton cooperativity of unity which can be reached with optical power as low as O (1 ) mW.

  12. On-chip microwave-to-optical quantum coherent converter based on a superconducting resonator coupled to an electro-optic microresonator

    CERN Document Server

    Javerzac-Galy, Clément; Bernier, Nathan; Toth, Laszlo D; Feofanov, Alexey K; Kippenberg, Tobias J

    2015-01-01

    We propose a device architecture capable of direct quantum electro-optical conversion of microwave to optical photons. The hybrid system consists of a planar superconducting microwave circuit coupled to an integrated whispering-gallery-mode microresonator made from an electro-optical material. We show that electro-optical (vacuum) coupling rates $g_0$ as large as$\\sim 2\\pi \\, \\mathcal{O}(10-100)$ kHz are achievable with currently available technology, due to the small mode volume of the planar microwave resonator. Operating at millikelvin temperatures, such a converter would enable high-efficiency conversion of microwave to optical photons. We analyze the added noise, and show that maximum conversion efficiency is achieved for a multi-photon cooperativity of unity which can be reached with optical power as low as $ \\mathcal{O}(1)\\,\\mathrm{mW} $.

  13. Synthesis and characterization of cross-linkable polyurethane-imide electro-optic waveguide polymer

    Science.gov (United States)

    Wang, Long-De; Tang, Jie; Li, Ruo-Zhou; Zhang, Tong; Tong, Ling; Tang, Jing

    2016-01-01

    The novel electro-optic (EO) polymers of fluorinated cross-linkable polyurethane-imides (CLPUI) were designed and synthesized by polycondensation of azo chromophore C1 and C2, diisocyanate MDI, and aromatic dianhydride 6FDA. Molecular structural characterization for the resulting polymers was achieved by 1HNMR, FT-IR, elemental analysis, and gel permeation chromatography. The polymers exhibit good film-forming properties, high glass transition temperature ( T g) in the range of 193-200 °C, and thermal stability up to 290 °C. The polymers that possess a high EO coefficient (γ_{33} = 48 and 56 pm/V) at 1550 nm for poled polymer thin films were measured by the simple reflection technique. Excellent temporal stability and low optical losses in the range of 1.1-1.7 dB/cm at 1550 nm were observed for these polymers. Using the synthesized side-chain electro-optic CLPUI as the active core material and of a fluorinated polyimide as cladding material, we have designed and successfully fabricated the high-performance polymer waveguide Mach-Zehnder EO modulators.

  14. Polymer Electro-optic Modulator Linear Bias Using the Thermo-optic Effect

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-Qiang; CHEN Chang-Ming; LI Xiao-Dong; WANG Xi-Bin; YANG Tian-Fu; ZHANG Da-Ming; WANG Fei; XIE Zhi-Yuan

    2012-01-01

    A quasi-rectangular waveguide polymer Mach-Zehnder (M-Z) electro-optic (EO) modulator based on an organic/inorganic hybrid material with thermal bias control is fabricated and demonstrated. Linear bias for the modulator is obtained through thermo-optic effect. The optical output is adjusted by changing phase difference between the two arms of the M-Z interferometer. A power consumption of 16.1 mW for π phase change is observed owing to the application of silica cladding. This approach is proved to be effective to suppress direct current drift in polymer EO modulators.%A quasi-rectangular waveguide polymer Mach-Zehnder (M-Z) electro-optic (EO) modulator based on an organic/inorganic hybrid material with thermal bias control is fabricated and demonstrated.Linear bias for the modulator is obtained through thermo-optic effect.The optical output is adjusted by changing phase difference between the two arms of the M-Z interferometer.A power consumption of 16.1 m W for π phase change is observed owing to the application of silica cladding.This approach is proved to be effective to suppress direct current drift in polymer EO modulators.

  15. Optimization Design Parameters of Electro-optic Modulators for Low Loss Wide Bandwidth Capability of Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-06-01

    Full Text Available The effects of temperature, and operating signal wavelength on high frequency radio frequency transmission characteristics are deeply investigated against various materials based electro optic modulator devices such as lithium Niobate (LiNbO3, polymer, and semiconductor materials. On the other hand, we have developed the optimization of the electro optic modulator parameters where the effective index plays an essential role in the evaluation of the bandwidth structure. The effects of design parameters on the modulating voltage and optical bandwidth are also investigated for different materials based electro optic modulators by using rigorous transmission modeling techniques. The low loss wide bandwidth capability of optoelectronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high capacity optical communication systems has required the use of modulation techniques in optical transmitters and receivers. This paper has presented the low loss wide bandwidth for different electrooptic modulators based on design of optimization parameters for high speed transmission performance.

  16. Weather and Atmospheric Effects on the Measurement and Use of Electro-Optical Signature Data

    Science.gov (United States)

    2017-02-01

    Atmospheric Effects on the Measurement and Use of Electro-Optical Signature Data RCC 469-17 February 2017 3 Table 1. General Sub- Region Terms of the...Atmospheric Effects on the Measurement and Use of Electro-Optical Signature Data RCC 469-17 February 2017 6 eye in all quantities. Multiple human eye ...on the Measurement and Use of Electro-Optical Signature Data RCC 469-17 February 2017 7 Table 4. Relative Spectral Response of the Eye λ

  17. Electro-optic and Many-body Effects on Optical Absorption of Twisted Bilayer Graphene

    Science.gov (United States)

    Lee, Kan-Heng; Huang, Lujie; Kim, Cheol-Joo; Park, Jiwoong

    2015-03-01

    In twisted bilayer graphene (tBLG), the interlayer rotation angle between the two graphene layers induces additional angle-dependent van Hove singularities (vHSs) in its band structure where the two Dirac cones from each layer intersect. These vHSs introduce extra angle-dependent absorption peaks in the optical absorption spectra of tBLG. Here, we experimentally investigate the effects of the overall doping and the interlayer potential on these interlayer absorption features at various angles. We independently tune the doping concentration of each layer with a newly-developed, optically transparent, dual-gate transistor geometry to perform simultaneous optical and electrical measurements. Our data show strong electro-optic phenomena in the optical absorption of tBLG: the peak energy and width of the interlayer resonance feature sensitively depends on the overall doping and interlayer potential. We explain our observation using a simple band picture as well as many-body effects. Our study provides a powerful experimental platform for studying more complicated structures such as rotated tri- and multi-layer graphene systems in the future. Moreover, the understanding of electro-optic and many-body effects in these materials opens up a way for novel electrochromic devices.

  18. Electro-optic analyzer of angular momentum hyperentanglement.

    Science.gov (United States)

    Wu, Ziwen; Chen, Lixiang

    2016-02-25

    Characterizing a high-dimensional entanglement is fundamental in quantum information applications. Here, we propose a theoretical scheme to analyze and characterize the angular momentum hyperentanglement that two photons are entangled simultaneously in spin and orbital angular momentum. Based on the electro-optic sampling with a proposed hyper-entanglement analyzer and the simple matrix operation using Cramer rule, our simulations show that it is possible to retrieve effectively both the information about the degree of polarization entanglement and the spiral spectrum of high-dimensional orbital angular momentum entanglement.

  19. Track Initiation for Electro-Optical Tracking of Space Objects

    Science.gov (United States)

    Xu, Z. W.; Wang, X.

    2016-03-01

    Aimed at the track initiation for the electro-optical tracking of space objects, and based on modified Hough transformation, a track initiation algorithm without prior information is proposed to realize the fully robotic identification and tracking of moving objects. The method is valid for the tracking of multi-target as well as with a non-continuous sequence. Simulation shows that the method is effective and applicable for operational usage, and is especially good for the search and discovery of new objects.

  20. Electro-optic probe measurements of electric fields in plasmas

    Science.gov (United States)

    Nishiura, M.; Yoshida, Z.; Mushiake, T.; Kawazura, Y.; Osawa, R.; Fujinami, K.; Yano, Y.; Saitoh, H.; Yamasaki, M.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2017-02-01

    The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

  1. Electro-Optical Modulator Bias Control Using Bipolar Pulses

    Science.gov (United States)

    Farr, William; Kovalik, Joseph

    2007-01-01

    An improved method has been devised for controlling the DC bias applied to an electro-optical crystal that is part of a Mach-Zehnder modulator that generates low-duty-cycle optical pulses for a pulse-position modulation (PPM) optical data-communication system. In such a system, it is desirable to minimize the transmission of light during the intervals between pulses, and for this purpose, it is necessary to maximize the extinction ratio of the modulator (the ratio between the power transmitted during an "on" period and the power transmitted during an "off" period). The present method is related to prior dither error feedback methods, but unlike in those methods, there is no need for an auxiliary modulation subsystem to generate a dithering signal. Instead, as described below, dither is effected through alternation of the polarity of the modulation signal. The upper part of Figure 1 schematically depicts a Mach-Zehnder modulator. The signal applied to the electro-optical crystal consists of a radio-frequency modulating pulse signal, VRF, superimposed on a DC bias Vbias. Maximum extinction occurs during the off (VRF = 0) period if Vbias is set at a value that makes the two optical paths differ by an odd integer multiple of a half wavelength so that the beams traveling along the two paths interfere destructively at the output beam splitter. Assuming that the modulating pulse signal VRF has a rectangular waveform, maximum transmission occurs during the "on" period if the amplitude of VRF is set to a value, V , that shifts the length of the affected optical path by a half wavelength so that now the two beams interfere constructively at the output beam splitter. The modulating pulse signal is AC-coupled from an amplifier to the electro-optical crystal. Sometimes, two successive pulses occur so close in time that the operating point of the amplifier drifts, one result being that there is not enough time for the signal level to return to ground between pulses. Also, the

  2. Electro-Optics of an Experimental Quantum-Optical Photometer

    Science.gov (United States)

    Solomos, N. H.

    2010-07-01

    The first working version of a new ultrafast three-beam photon counting photometer (QOP) has been materialized and demonstrated by the Applied Physics / Electro-optics Laboratory of the Hellenic Naval Academy in Piraeus. The QOP has been installed on the new 0.51m TVD telescope. The instrument is currently being used for quantum-optical study of atmospheric transmission in green monochromatic light over slant paths, at the RFK/Eudoxos Observatories. Actively quenched Single Photon Avalanche Diode detectors can be interchangeably deployed in addition to PMTs and LLL-CCDs. It is also intended for the testing of various approaches for solving the difficult problem of coupling light efficiently to the very small sensitive areas of SPADS, either using fiber couplers, or novel technologies like dedicated fiber tapers. Some particulars of the instrument design philosophy and its optomechanical construction are very briefly mentioned further below. However, it is appropriate to comment, firstly, on its purpose/rationale: The successful formalism of Glauber that led to the quantum-optical framework pertinent to the study of light in the terrestrial laboratories could, perhaps, be proven equally fruitful if applied to celestial light as well. Adopting the new idea of describing an arbitrary light state in terms of coherence functions, it is easily concluded that conventional astronomical instrumentation measures only spatial (imaging) or temporal (spectroscopy) coherence properties of the incoming photon stream. However, higher order spatiotemporal coherence (manifested as correlations among separated photon detection events) convey blueprints of the emission mechanism itself or even of the photon scattering history written in the course of the long path from the emitter to the telescope. To extract this information, high photon fluxes and unprecedented timing resolutions are needed. Our gradual entrance to the era of Extremely Large Telescopes combined with certain new

  3. A new electro-optic waveguide architecture and the unprecedented devices it enables

    Science.gov (United States)

    Davis, Scott R.; Rommel, Scott D.; Farca, George; Anderson, Michael H.

    2008-04-01

    A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

  4. Non-linear canonical correlation

    NARCIS (Netherlands)

    van der Burg, Eeke; de Leeuw, Jan

    1983-01-01

    Non-linear canonical correlation analysis is a method for canonical correlation analysis with optimal scaling features. The method fits many kinds of discrete data. The different parameters are solved for in an alternating least squares way and the corresponding program is called CANALS. An

  5. Non-Linear Mixed Logit

    DEFF Research Database (Denmark)

    Andersen, Steffen; Harrison, Glenn W.; Hole, Arne Risa

    2012-01-01

    We develop an extension of the familiar linear mixed logit model to allow for the direct estimation of parametric non-linear functions defined over structural parameters. Classic applications include the estimation of coefficients of utility functions to characterize risk attitudes and discountin...

  6. Non-linear finite element analysis in structural mechanics

    CERN Document Server

    Rust, Wilhelm

    2015-01-01

    This monograph describes the numerical analysis of non-linearities in structural mechanics, i.e. large rotations, large strain (geometric non-linearities), non-linear material behaviour, in particular elasto-plasticity as well as time-dependent behaviour, and contact. Based on that, the book treats stability problems and limit-load analyses, as well as non-linear equations of a large number of variables. Moreover, the author presents a wide range of problem sets and their solutions. The target audience primarily comprises advanced undergraduate and graduate students of mechanical and civil engineering, but the book may also be beneficial for practising engineers in industry.

  7. Modeling of multilayer electrode performance in transverse electro-optic modulators

    Directory of Open Access Journals (Sweden)

    Minmin Zhu

    2011-12-01

    Full Text Available For some electro-optic (EO modulators, lowering the driving voltage is necessary to reduce the power consumption of the modulators. There are four significant factors influencing the driving voltage of the EO modulators: geometrical parameters of wafer and electrodes, surface and embedded electrodes, material properties of wafer, and structure of modulators. Using the superposition method and surface charge technique, the electric fields, halfwave voltages, switching times and optical transmissions of EO modulators with two-layer, three-layer, and four-layer electrodes are calculated, respectively. It is found that the halfwave voltage decreases while the switching time increase slightly as the number of layers increases. Such study demonstrates that using multilayer electrodes is an effective technique of lowering the halfwave voltage, which may have implication of EO modulator design.

  8. Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.

    Science.gov (United States)

    Xiao, Pingping; Wang, Xianping; Sun, Jingjing; Huang, Meizhen; Chen, Xianfeng; Cao, Zhuangqi

    2012-06-18

    A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established. With this correlation and the measurement of the effective RI change to the applied voltage, the quadratic EO and CPE coefficients of PMN-PT ceramics are obtained simultaneously. The obtained results are further checked by fitting the variations of effective RI to a quadratic function. Our measurement method can be extended to a wide range of other materials.

  9. Capacitively-Induced Free-Carrier Effects in Nanoscale Silicon Waveguides for Electro-Optic Modulation

    CERN Document Server

    Sharma, Rajat; Lin, Hung-Hsi; Isichenko, Andrei; Vallini, Felipe; Fainman, Yeshaiahu

    2015-01-01

    We fabricate silicon waveguides in silicon-on-insulator (SOI) wafers clad with either silicon dioxide, silicon nitride, or aluminum oxide, and by measuring the electro-optic behavior of ring resonators, we characterize the cladding-dependent and capacitively-induced free-carrier effects in each of these waveguides. By comparing our measured data with simulation results, we confirm that the observed voltage dependencies of the transmission spectra are due to changes in the concentrations of holes and electrons within the semiconductor waveguide, and we show for the first time how strongly these effects depend on the cladding material which comes into contact with the silicon waveguide. Additionally, the waveguide loss is found to have a particularly high sensitivity to the applied voltage, and may therefore find use in a wide range of applications which require low- or high-loss propagation. Collectively, these phenomena may be incorporated into more complex waveguide designs in the future to create high-effic...

  10. Synthesis, characterizations and electro-optical properties of nonlinear optical polyimide/silica hybrid

    Directory of Open Access Journals (Sweden)

    2007-03-01

    Full Text Available Transparent Nonlinear Optical (NLO inorganic/organic (polyimide/silica hybrid composites with covalent links between the inorganic and the organic networks were prepared by the sol-gel method. The silica content in the hybrid films was varied from 0 to 22.5/wt%. The prepared PI hybrids were characterized by IR, UV-Vis, Thermogravimetric analysis (TGA, X-ray diffraction (XRD, Scanning Electron Microscopy (SEM and Transmission Electron Microscopy (TEM. They exhibited fair good optical transparency. The SiO2 phase was well dispersed in the polymer matrix. DSC and TGA results showed that these hybrid materials had excellent thermal stability. The polymer solutions could be spin coated on the indium-tin-oxide (ITO glass to form optical quality thin films. The electro-optic coefficients (γ33 at the wavelength of 832 nm for polymer thin films poled were in the range of 19-27 pm/V.

  11. Electro-optically tunable diffraction grating with photoaligned liquid crystals

    Science.gov (United States)

    Węgłowski, Rafał; Kozanecka-Szmigiel, Anna; Piecek, Wiktor; Konieczkowska, Jolanta; Schab-Balcerzak, Ewa

    2017-10-01

    This work shows the possibility of fabricating one- and two-dimensional diffraction structures based on liquid crystals photoaligned with the layers of photosensitive azobenzene poly(ester imide). The gratings involve a micron-sized planar-twisted nematic alignment. The diffraction efficiency of these gratings is controlled by a uniform electric field applied across the cell. The electro-optical measurements showed short switching times (0.8 ms and 7 ms for τrise and τdecay respectively) and low driving electric fields (1 . 5 V / μm) of 1st order diffracted light. The LC grating is regarded as an amplitude grating in the low electric field region and a phase grating in the high electric field region. Moreover the diffraction efficiency is polarization-independent in the wide range of external electric fields.

  12. Control Schemes for Driving Electro-optic Array Beam Deflectors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The beam deflectors based on electro-optic phased array(EOPA) is mainly described, and then an analysis on existing control schemes for driving the EOPA beam deflectors, based on custom hard-wired electronics or based on software in a microcontroller, is made. Compared with these, a driving and control system for a multi-channel EOPA beam deflector is presented, in which the control assignment is implemented with a field programmable gate array(FPGA) chip. For different performance requirements, two control schemes, one with the serial scheme and another with the parallel scheme, have been explored and rapidly prototyped in Xilinx FPGA chips. With the control structures for the EOPA beam deflector, scanning rates of 588kHz and 5MHz can be respectively reached.

  13. Double-Teeth-Shaped Plasmonic Waveguide Electro-Optical Switches

    Institute of Scientific and Technical Information of China (English)

    ZHU Jia-Hu; HUANG Xu-Guang; MEI Xian

    2011-01-01

    @@ An electro-optical switch based on a plasmonic T-shaped waveguide structure with a double-teeth-shaped waveguide filled with 4-dimet4ylamino-N-methyl-4stilbazolium tosylate is proposed and numerically investigated.TheFinite-difference time domain simulation results reveal that the structure can operate as a circuit switch by controlling the external voltages V1 and/or V2.The proposed structure can also operate as a variable optical attenuator, which can continuously attenuate the power of a light beam from 6dB to 30dB by an external electrical field.The structure is of small size of a few hundred nanometers.Our results may open a possibility to construct nanoscale high-density photonic integration circuits.

  14. Electro-Optical Detection of Charged Particle Beams

    CERN Document Server

    Semertzidis, Y K; Kowalski, L A; Kraus, D E; Larsen, R C; Lazarus, D M; Magurno, B; Srinivasan-Rao, T; Tsang, Thomas; Usack, V

    1999-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the propagation of laser light in a birefringent crystal at the Brookhaven National Laboratory Accelerator Test Facility. Polarized infrared light was coupled to a LiNbO3 crystal through a polarization maintaining fiber of 4 micron diameter. An electron beam in 10ps bunches of 1mm diameter was scanned across the crystal. The modulation of the laser light during passage of the electron beam was observed using a photodiode with 45GHz bandwidth. The fastest rise time measured, 120ps, was made in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. Both polarization dependent and polarization independent effects were observed. This technology holds promise of greatly improved spatial and temporal resolution of charged particle beams.

  15. Differential and Integral Isoconversional Non-linear Methods and Their Application to Energetic Materials.III.Non-isothermal Decomposition Reaction Kinetics of Benzotrifuroxan

    Institute of Scientific and Technical Information of China (English)

    GAO Hong-Xu; ZHAO Feng-Qi; HU Rong-Zu; ZHANG Hai; DONG Hai-Shan; YAO Pu; XU Zhou; HU Gang

    2008-01-01

    The thermal behaviour and decomposition reaction kinetics of benzotrifuroxan(BTF)were determined by TG and DSC techniques.The kinetic parameters of the exothermic decomposition reaction in a temperature pro-grammed mode(the apparent activation energy Ea and pre-exponential factor A)were calculated by a single non-isothermal DSC curve.The E values calculated using the Kissinger and Flynn-Wall-Ozawa equations and inte-gral isoconversional non-linear equations were used to check the validity of activation energy by a single non-isothermal DSC curve.The results show that the kinetic model function in integral form and the values of Ea respectively.The critical temperature of thermal explosion of BTF is 257.33 ℃.

  16. Non-linear Ultrasound Imaging

    DEFF Research Database (Denmark)

    Du, Yigang

    without iteration steps. The ASA is implemented in combination with Field II and extended to simulate the pulsed ultrasound fields. The simulated results from a linear array transducer are made by the ASA based on Field II, and by a released non-linear simulation program- Abersim, respectively....... The calculation speed of the ASA is increased approximately by a factor of 140. For the second harmonic point spread function the error of the full width is 1.5% at -6 dB and 6.4% at -12 dB compared to Abersim. To further investigate the linear and non-linear ultrasound fields, hydrophone measurements.......3% relative to the measurement from a 1 inch diameter transducer. A preliminary study for harmonic imaging using synthetic aperture sequential beamforming (SASB) has been demonstrated. A wire phantom underwater measurement is made by an experimental synthetic aperture real-time ultrasound scanner (SARUS...

  17. Design principles and realization of electro-optical circuit boards

    Science.gov (United States)

    Betschon, Felix; Lamprecht, Tobias; Halter, Markus; Beyer, Stefan; Peterson, Harry

    2013-02-01

    The manufacturing of electro-optical circuit boards (EOCB) is based to a large extent on established technologies. First products with embedded polymer waveguides are currently produced in series. The range of applications within the sensor and data communication markets is growing with the increasing maturity level. EOCBs require design flows, processes and techniques similar to existing printed circuit board (PCB) manufacturing and appropriate for optical signal transmission. A key aspect is the precise and automated assembly of active and passive optical components to the optical waveguides which has to be supported by the technology. The design flow is described after a short introduction into the build-up of EOCBs and the motivation for the usage of this technology within the different application fields. Basis for the design of EOCBs are the required optical signal transmission properties. Thereafter, the devices for the electro-optical conversion are chosen and the optical coupling approach is defined. Then, the planar optical elements (waveguides, splitters, couplers) are designed and simulated. This phase already requires co-design of the optical and electrical domain using novel design flows. The actual integration of an optical system into a PCB is shown in the last part. The optical layer is thereby laminated to the purely electrical PCB using a conventional PCB-lamination process to form the EOCB. The precise alignment of the various electrical and optical layers is thereby essential. Electrical vias are then generated, penetrating also the optical layer, to connect the individual electrical layers. Finally, the board has to be tested electrically and optically.

  18. Assessment of Spacecraft Operational Status Using Electro-Optical Predictive Techniques

    Science.gov (United States)

    Swann, D.; Klem, B.; McCoy, B.

    2010-09-01

    The current class of small satellite systems presents an analyst responsible for monitoring spacecraft operational status and early detection of detrimental anomalies with a broad variety of sensing and identification issues and challenges. Simple, small, cube-shaped satellites, without protruding solar panel appendages, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical sensors. This paper will describe spacecraft optical signature modeling and simulation techniques to develop sensing and identification algorithms for observing and characterizing key spacecraft features. The simulation results are based on electro-optical signatures apparent to nonimaging sensors, along with related observable features derived from multicolor and multiviewing aspect scenarios. This model and simulation analysis capability is used to support programs to monitor spacecraft performance status and identify anomalies associated with spacecraft damage/deterioration due to space debris or micrometeorite impact, thruster exhaust deposition or material aging. The development of state-of-the-art optical signature modeling tools to perform high-fidelity satellite models (such as the Air Force Academy FalconSat-5 or AFRL TacSat-3) simulations to characterize spectral radiant intensities apparent to passive, remote, nonresolved imaging sensors are described in detail. Simulations are performed for a comprehensive scenario range of natural (solar and earth) illumination and viewing conditions. Results are generated for comparing baseline, streamlined geometry models with the actual higher fidelity models that capture vehicle small-size hardware components and modifications. Output consisting of radiant intensity history apparent to ground-based sensor locations for vehicle trajectories that capture a comprehensive range of illumination conditions from the sun and underlying earth scene are presented for extensive spectral band

  19. Simulation of electro-optical imaging system based on OpenGL

    Science.gov (United States)

    Zhu, Yong; Fu, Qiang; Duan, Jin; Jing, Wen-bo

    2013-08-01

    With the development of electro-optical imaging system technology and simulation technology, and the demand of optimizing the new type electro-optical imaging system theoretical model, more and more scientific research institutes, colleges and universities research on the simulation of electro-optical imaging system, and the better results were obtained. Simulation technology saved the cost of system design development, meanwhile, some complex and hard to re-implement experiments can be carried repeatedly. According to the demand of complex environment construction technology and the requirement of imaging simulation system fidelity, considering the performance of electro-optical imaging system, an electro-optical imaging system is modeled. The modeling has two aspects which is scene characteristic modeling and electro-optical system modeling. Scene characteristic modeling can construct dynamic scenes in different kinds of complex environments by using powerful OpenGL three-dimension model visualization technology. Electro-optical system modeling is consist of optical system and imaging detector. Electro-optical imaging system simulation model is established with the analysis of electro-optical imaging system theory. The use of modular design concept and general interface technology is combined. Different imaging effect is received under different parameters by modifying the model's related parameters. The experimental results show that, the image produced from simulation basically reflects the performance of imaging system, so this kind of image can be used as a information source for imaging system performance analysis. It provides a simple and feasible method for the analysis of imaging system performance, which has a very important practical significance.

  20. Shot noise reduced terahertz detection via spectrally post-filtered electro-optic sampling

    CERN Document Server

    Porer, Michael; Huber, Rupert

    2016-01-01

    In ultrabroadband terahertz electro-optic sampling, spectral filtering of the gate pulse can strongly reduce the quantum noise while the signal level is only weakly affected. The concept is tested for phase-matched electro-optic detection of field transients centered at 45 THz with 12-fs near-infrared gate pulses in AgGaS2. Our new approach increases the experimental signal-to-noise ratio by a factor of 3 compared to standard electro-optic sampling. Under certain conditions an improvement factor larger than 5 is predicted by our theoretical analysis.

  1. Measurement of the linear electro-optic coefficient of a minute cBN sample

    Institute of Scientific and Technical Information of China (English)

    DOU; Qingping; MA; Haitao; JIA; Gang; CHEN; Zhanguo; ZHANG

    2005-01-01

    Cubic boron nitride (Cbn) is a kind of artificial (synthetic) crystal. Transverse electro-optic modulation in a minute Cbn sample was carried out. Basing on the practical form of the crystal, we established the theoretical and experimental method according to the sample. For the first time, the linear electro-optic effect was observed in Cbn, and half-wave voltage of the Cbn sample was measured successfully. Furthermore, its linear electro-optic coefficient was calculated at 1.17×10-14 m/V.

  2. Photoelectrochemistry of Electronic and Electro-Optical Materials

    Science.gov (United States)

    1992-09-01

    Etching of Blazed Echelle Gratings in n-GaAs", presented at the Fall Meeting of the Electrochemical Society , Chicago, IL, October 9-14, 1988. 3...SiC", Fall Meeting of the Electrochemical Society , Hollywood, FL, October 15-20, 1989. 5. "Morphology Control of Photoelectrochemically Etched...Profiles in n-GaAs", presented at the Fall Meeting of the Electrochemical Society , Hollywood, FL, October 15-20, 1989. 6. "The Evaluation of

  3. Modelling Loudspeaker Non-Linearities

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.

    2007-01-01

    This paper investigates different techniques for modelling the non-linear parameters of the electrodynamic loudspeaker. The methods are tested not only for their accuracy within the range of original data, but also for the ability to work reasonable outside that range, and it is demonstrated...... that polynomial expansions are rather poor at this, whereas an inverse polynomial expansion or localized fitting functions such as the gaussian are better suited for modelling the Bl-factor and compliance. For the inductance the sigmoid function is shown to give very good results. Finally the time varying...

  4. Progress in Nano-Electro-Optics VII Chemical, Biological, and Nanophotonic Technologies for Nano-Optical Devices and Systems

    CERN Document Server

    Ohtsu, Motoichi

    2010-01-01

    This book focuses on chemical and nanophotonic technology to be used to develop novel nano-optical devices and systems. It begins with temperature- and photo-induced phase transition of ferromagnetic materials. Further topics include: energy transfer in artificial photosynthesis, homoepitaxial multiple quantum wells in ZnO, near-field photochemical etching and nanophotonic devices based on a nonadiabatic process and optical near-field energy transfer, respectively and polarization control in the optical near-field for optical information security. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  5. Future electro-optical sensors and processing in urban operations

    Science.gov (United States)

    Grönwall, Christina; Schwering, Piet B.; Rantakokko, Jouni; Benoist, Koen W.; Kemp, Rob A. W.; Steinvall, Ove; Letalick, Dietmar; Björkert, Stefan

    2013-10-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and

  6. Electro-Optic Laser Scanners for Space-Based Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this phase II SBIR is to design and build new non-mechanical, electro-optic (EO) laser scanners that will be suitable for space based laser ranging,...

  7. High Power Electro-Optic Modulator for Space-Based Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I effort will establish the feasibility of developing a fiber coupled, high power, electro-optically controlled, space...

  8. Electro-Optic Laser Scanners for Space-Based Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Vescent Photonics propose to design and build revolutionary non-mechanical, electro-optic (EO) laser scanners that will be suitable for space based laser ranging,...

  9. Structure Design of Polymer Electro-Optic Modulator with Ultra- Broadband

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Using finite element method, lots of calculating focusing on polymer electro-optic modulators with ultra-broadband were done, a few structures were analyzed. Coplanar waveguide electrode system was advanced, a few real examples was given.

  10. A Novel Electro-Optic Polymer Modulator Based on Long Period Fiber Gratings

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Dong; Li Pei; Bin Li; Shui-sheng Jian

    2003-01-01

    A novel high-speed electro-optic (EO) polymer modulator based on long period gratings (LPG) is designed. Using the theory of multi-cladding optical waveguide, we achieved relationship between modulate voltage and LPG’s resonant wavelength.

  11. A Novel Electro-Optic Polymer Modulator Based on Long Period Fiber Gratings

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel high-speed electro-optic (EO) polymer modulator based on long period gratings (LPG) is designed. Using the theory of multi-cladding optical waveguide, we achieved relationship between modulate voltage and LPG's resonant wavelength.

  12. Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is an advanced Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System (ATTIREOIS). ATTIREOIS sensor payload consists of two sets of...

  13. Tunable Optical Filters Having Electro-optic Whispering-gallery-mode Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy (Inventor); Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor); Maleki, Lutfollah (Inventor)

    2006-01-01

    Tunable optical filters using whispering-gallery-mode (WGM) optical resonators are described. The WGM optical resonator in a filter exhibits an electro-optical effect and hence is tunable by applying a control electrical signal.

  14. High Power Electro-Optic Modulator for Space-Based Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ADVR, Inc. proposes the development of a fiber coupled, high power, electro-optically controlled, space qualified, phase modulator for the NASA Laser Interferometer...

  15. Electro-optical and dielectric properties of a high tilt antiferroelectric liquid crystal mixture (W-193B)

    Energy Technology Data Exchange (ETDEWEB)

    Nayek, Prasenjit; Ghosh, Sharmistha; Kundu, Sudarshan; Roy, Subir Kr [Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700032 (India); Majumder, Tapas Pal [Department of Physics, University of Kalyani, Kalyani-741235, West Bengal (India); Bennis, Noureddine; Oton, Jose Manuel [Department of TecnologIa Fotonica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Dabrowski, Roman, E-mail: spskr@iacs.res.i [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland)

    2009-11-21

    The electro-optical properties and dielectric relaxation have been investigated for an antiferroelectric liquid crystal mixture W-193B. The material exhibits smectic A*, smectic C* and a wide range of anticlinic smectic C{sub A}{sup *} phases. The high tilt and broad room temperature smectic C{sub A}{sup *} phase make it a good candidate for antiferroelectric display materials. Dielectric studies have been made in a planarly aligned cell in the frequency range 10 Hz-13 MHz. Dielectric spectroscopy reveals the existence of soft mode in the smectic A* phase and Goldstone mode in the smectic C* phase. In the smectic C{sub A}{sup *} phase the dielectric spectrum of the material exhibits two absorption peaks related to the rotational fluctuation around the short axis of the molecules and antiphase azimuthal angle fluctuation, respectively, and are separated by about two orders of frequency. Electro-optical response using a low frequency triangular wave showed a very high quasi-static contrast ratio of 132 : 1, threshold voltage of around 7 V and saturation of 17 V. Surface-stabilized, low thickness cells of this mixture showed a perfect double hysteresis loop with a 1 Hz triangular signal, reaching different transmission levels for different voltage amplitudes. These levels can be stabilized with a single holding voltage, making it possible for the material to be passively multiplexed at video rate.

  16. Electro-optic sampling of near-infrared waveforms

    Science.gov (United States)

    Keiber, Sabine; Sederberg, Shawn; Schwarz, Alexander; Trubetskov, Michael; Pervak, Volodymyr; Krausz, Ferenc; Karpowicz, Nicholas

    2016-03-01

    Access to the complete electric field evolution of a laser pulse is essential for attosecond science in general, and for the scrutiny and control of electron phenomena in solid-state physics specifically. Time-resolved field measurements are routine in the terahertz spectral range, using electro-optic sampling (EOS), photoconductive switches and field-induced second harmonic generation. EOS in particular features outstanding sensitivity and ease of use, making it the basis of time-resolved spectroscopic measurements for studying charge carrier dynamics and active optical devices. In this Letter, we show that careful optical filtering allows the bandwidth of this technique to be extended to wavelengths as short as 1.2 μm (230 THz) with half-cycle durations 2.3 times shorter than the sampling pulse. In a proof-of-principle application, we measure the influence of optical parametric amplification (OPA) on the electric field dynamics of a few-cycle near-infrared (NIR) pulse.

  17. Electro-Optical Design for Efficient Visual Communication

    Science.gov (United States)

    Huck, Friedrich O.; Fales, Carl L.; Jobson, Daniel J.; Rahman, Zia-Ur

    1995-01-01

    Visual communication, in the form of telephotography and television, for example, can be regarded as efficient only if the amount of information that it conveys about the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. Elsewhere we have addressed the problem of assessing the end to end performance of visual communication systems in terms of their efficiency in this sense by integrating the critical limiting factors that constrain image gathering into classical communications theory. We use this approach to assess the electro-optical design of image gathering devices as a function of the f number and apodization of the objective lens and the aperture size and sampling geometry of the phot-detection mechanism. Results show that an image gathering device that is designed to optimize information capacity performs similarly to the human eye. For both, the performance approaches the maximum possible, in terms of the efficiency with which the acquired information can be transmitted as decorrelated data, and the fidelity, sharpness, and clearity with which fine detail can be restored.

  18. Electro-Optical Imaging Fourier-Transform Spectrometer

    Science.gov (United States)

    Chao, Tien-Hsin; Zhou, Hanying

    2006-01-01

    An electro-optical (E-O) imaging Fourier-transform spectrometer (IFTS), now under development, is a prototype of improved imaging spectrometers to be used for hyperspectral imaging, especially in the infrared spectral region. Unlike both imaging and non-imaging traditional Fourier-transform spectrometers, the E-O IFTS does not contain any moving parts. Elimination of the moving parts and the associated actuator mechanisms and supporting structures would increase reliability while enabling reductions in size and mass, relative to traditional Fourier-transform spectrometers that offer equivalent capabilities. Elimination of moving parts would also eliminate the vibrations caused by the motions of those parts. Figure 1 schematically depicts a traditional Fourier-transform spectrometer, wherein a critical time delay is varied by translating one the mirrors of a Michelson interferometer. The time-dependent optical output is a periodic representation of the input spectrum. Data characterizing the input spectrum are generated through fast-Fourier-transform (FFT) post-processing of the output in conjunction with the varying time delay.

  19. Configuration of electro-optic fire source detection system

    Science.gov (United States)

    Fabian, Ram Z.; Steiner, Zeev; Hofman, Nir

    2007-04-01

    The recent fighting activities in various parts of the world have highlighted the need for accurate fire source detection on one hand and fast "sensor to shooter cycle" capabilities on the other. Both needs can be met by the SPOTLITE system which dramatically enhances the capability to rapidly engage hostile fire source with a minimum of casualties to friendly force and to innocent bystanders. Modular system design enable to meet each customer specific requirements and enable excellent future growth and upgrade potential. The design and built of a fire source detection system is governed by sets of requirements issued by the operators. This can be translated into the following design criteria: I) Long range, fast and accurate fire source detection capability. II) Different threat detection and classification capability. III) Threat investigation capability. IV) Fire source data distribution capability (Location, direction, video image, voice). V) Men portability. ) In order to meet these design criteria, an optimized concept was presented and exercised for the SPOTLITE system. Three major modular components were defined: I) Electro Optical Unit -Including FLIR camera, CCD camera, Laser Range Finder and Marker II) Electronic Unit -including system computer and electronic. III) Controller Station Unit - Including the HMI of the system. This article discusses the system's components definition and optimization processes, and also show how SPOTLITE designers successfully managed to introduce excellent solutions for other system parameters.

  20. Bandwidth enhancement of electro-optic field sensing using photonic down-mixing with harmonic sidebands.

    Science.gov (United States)

    Lee, Dong-Joon; Whitaker, John F

    2008-09-15

    We demonstrate that harmonic sidebands of an electro-optic modulator's driving frequency can be used as the local oscillator in a photonic down-mixing process in order to significantly enhance the bandwidth of near-field, electro-optic, microwave measurements. The creation of second- and third-order-harmonic modulation sidebands on a laser-diode output are described, with heterodyne down-conversion of microwave signals taking place within an electro-optic sensor crystal. The measurement bandwidth of an electro-optic microwave probe can thus be enhanced by as much as a factor of three with respect to the use of conventional, fundamental-harmonic sidebands. Carrier-sideband analysis from the measured optical spectrum indicates that millimeter-wave-frequency local-oscillator sidebands can be created using a Ku-band electro-optic modulator and that the electro-optic-signal-modulation depth can be enhanced by suppressing the light-beam carrier component. Transverse near-field distributions from high frequency patch antennas are extracted using both second- and third-order-harmonic sidebands.

  1. Internal model control of a fast steering mirror for electro-optical fine tracking

    Science.gov (United States)

    Xia, Yun-xia; Bao, Qi-liang; Wu, Qiong-yan

    2010-11-01

    The objective of this research is to develop advanced control methods to improve the bandwidth and tracking precision of the electro-optical fine tracking system using a fast steering mirror (FSM). FSM is the most important part in this control system. The model of FSM is established at the beginning of this paper. Compared with the electro-optical fine tracking system with ground based platform, the electro-optical fine tracking system with movement based platform must be a wide bandwidth and a robustness system. An advanced control method based on internal model control law is developed for electro-optical fine tracking system. The IMC is an advanced algorithm. Theoretically, it can eliminate disturbance completely and make sure output equals to input even there is model error. Moreover, it separates process to the system dynamic characteristic and the object perturbation. Compared with the PID controller, the controller is simpler and the parameter regulation is more convenient and the system is more robust. In addition, we design an improved structure based on classic IMC. The tracking error of the two-port control system is much better than which of the classic IMC. The simulation results indicate that the electro-optical control system based on the internal model control algorithm is very effective. It shows a better performance at the tracing precision and the disturbance suppresses. Thus a new method is provided for the high-performance electro-optical fine tracking system.

  2. Fundamental limits on the electro-optic device figure of merit

    CERN Document Server

    Mossman, Sean; Kuzyk, Mark G

    2016-01-01

    Device figures of merit are commonly employed to assess bulk material properties for a particular device class, yet these properties ultimately originate in the linear and nonlinear susceptibilities of the material which are not independent of each other. In this work, we calculate the electro-optic device figure of merit based on the half-wave voltage and linear loss, which is important for phase modulators and serves as the simplest example of the approach. This figure of merit is then related back to the microscopic properties in the context of a dye-doped polymer, and its fundamental limits are obtained to provide a target. Surprisingly, the largest figure of merit is not always associated with a large nonlinear-optical response, the quantity that is most often the focus of optimization. An important lesson to materials design is that the figure of merit alone should be optimized. The best device materials can have low nonlinearity provided that the loss is low; or, near resonance high loss may be desirab...

  3. NICMOS non-linearity tests

    Science.gov (United States)

    de Jong, Roelof

    2005-07-01

    This program incorporates a number of tests to analyse the count rate dependent non-linearity seen in NICMOS spectro-photometric observations. In visit 1 we will observe a few fields with stars of a range in luminosity in NGC1850 with NICMOS in NIC1 in F090M, F110W and F160W and NIC2 F110W, F160W, and F180W. We will repeat the observations with flatfield lamp on, creating artificially high count-rates, allowing tests of NICMOS linearity as function of count rate. To access the effect of charge trapping and persistence, we first take darks {so there is not too much charge already trapped}, than take exposures with the lamp off, exposures with the lamp on, and repeat at the end with lamp off. Finally, we continue with taking darks during occultation. In visit 2 we will observe spectro-photometric standard P041C using the G096 and G141 grisms in NIC3, and repeat the lamp off/on/off test to artificially create a high background. In visits 3&4 we repeat photometry measurements of faint standard stars SNAP-2 and WD1657+343, on which the NICMOS non-linearity was originally discovered using grism observations. These measurements are repeated, because previous photometry was obtained with too short exposure times, hence substantially affected by charge trapping non-linearity. Measurements will be made with NIC1: Visit 5 forms the persistence test of the program. The bright star GL-390 {used in a previous persistence test} will iluminate the 3 NICMOS detectors in turn for a fixed time, saturating the center many times, after which a series of darks will be taken to measure the persistence {i.e. trapped electrons and the decay time of the traps}. To determine the wavelength dependence of the trap chance, exposures of the bright star in different filters will be taken, as well as one in the G096 grism with NIC3. Most exposures will be 128s long, but two exposures in the 3rd orbit will be 3x longer, to seperate the effects of count rate versus total counts of the trap

  4. Dependence of electro-optical properties on the deposition conditions of chemical bath deposited CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dona, J.M.; Herrero, J. [CIEMAT, Madrid (Spain). Inst. de Energias Renovables

    1997-11-01

    Lately, there has been a sharp increase in the publication of papers on chemical bath deposition of CdS thin films and related materials due to successful results obtained using this method to fabricate CdS thin-film buffer layers for CuInSe{sub 2}- and CdTe-based polycrystalline thin-film solar cells. Generally, these papers focus on previously proposed methods of studying film characteristics without a systematic study of the influence of deposition conditions on film characteristics. In this paper the authors present an exhaustive study of the chemical bath-deposited CdS thin films electro-optical properties dependence on deposition variables. The authors propose not only a set of conditions for obtaining CdS thin films by this method but additionally, suitable deposition process conditions for certain application requirements, such as buffer layers for thin-film solar cells. The observed electro-optical characteristics dependence on the deposition variables corroborates the chemical mechanism that they proposed previously for this process.

  5. Canopy induced aberration correction in airborne electro-optical imaging systems

    Science.gov (United States)

    Harder, James A.; Sprague, Michaelene W.

    2011-11-01

    An increasing number of electro-optical systems are being used by pilots in tactical aircraft. This means that the afore mentioned systems must operate through the aircrafts canopy, unfortunately the canopy functions as a less than ideal lens element in the electro-optical sensor optical path. The canopy serves first and foremost as an aircraft structural component, considerations like minimizing the drag co-efficient and the ability to survive bird strikes take precedence over achieving optimal optical characteristics. This paper describes how the authors characterized the optical characteristics of an aircraft canopy. Families of modulation transfer functions were generated, for various viewing geometries through the canopy and for various electro-optical system entrance pupil diameters. These functions provided us with the means to significantly reduce the effect of the canopy "lens" on the performance of a representative electro-optical system, using an Astigmatic Corrector Lens. A comparison of the electro-optical system performance with and without correction is also presented.

  6. Design and implementation of an electro-optical backplane with pluggable in-plane connectors

    Science.gov (United States)

    Pitwon, Richard C. A.; Hopkins, Ken; Wang, Kai; Selviah, David R.; Baghsiahi, Hadi; Offrein, Bert J.; Dangel, Roger; Horst, Folkert; Halter, Markus; Gmür, Max

    2010-02-01

    The design, implementation and characterisation of an electro-optical backplane and an active pluggable optical connector technology are presented. The connection architecture adopted allows line cards to mate and unmate from a passive electro-optical backplane with embedded polymeric waveguides. The active connectors incorporate photonics interfaces operating at 850 nm and a mechanism to passively align the interface to the embedded optical waveguides. A demonstration platform has been constructed to assess the viability of embedded electro-optical backplane technology in dense data storage systems. The electro-optical backplane is comprised of both copper layers and one polymeric optical layer, whereon waveguides have been patterned by a direct laser writing scheme. The optical waveguide design includes arrayed multimode waveguides with a pitch of 250 μm, multiple cascaded waveguide bends, non-orthogonal crossovers and in-plane connector interfaces. In addition, a novel passive alignment method has been employed to simplify high precision assembly of the optical receptacles on the backplane. The in-plane connector interface is based on a two lens free space coupling solution, which reduces susceptibility to contamination. The loss profiles of the complex optical waveguide layout has been characterised and successful transfer of 10.3 Gb/s data along multiple waveguides in the electro-optical backplane demonstrated.

  7. Modelling the Electro-Optic Properties of Liquid Crystals.

    Science.gov (United States)

    MacGregor, Alastair R.

    Available from UMI in association with The British Library. Requires signed TDF. Liquid crystals (LCs) have been recognised as a phase of matter intermediate between solid and liquid for about 100 years. During this time a large variety of mesophases have been discovered but it is only recently that their physics have begun to be understood. However if LCs are to continue to compete successfully in the displays market an improved understanding of their electro-optic properties must be gained. This thesis describes work carried out on two different types of LC: nematic and ferroelectric chiral smectic C (SmC^{*} ). In the former the molecules are orientationally ordered and randomly positioned while in the latter they are orientationally ordered and arranged in layers. The local mean molecular orientation is called the director and defines the uniaxial optic axis in both types of LC. In a nematic guest-host (NGH) LC an anisotropically absorbing dye is dissolved in the LC and the dye molecules align so that their maximum absorption axis is parallel to the director. When an electric field is applied to a cell containing NGHLC the molecules tend to rotate, because of their dielectric anisotropy, and alter the cell's transmittance. Previous attempts to model the change in optical transmittance with voltage have assumed that the LC and dye molecules are perfectly aligned with the director. In this work the disorder of the molecules about the director is taken into account and the overall agreement between theory and experiment is improved considerably. A method of calculating how the SmC^ {*} director configuration and layer orientation vary with voltage is presented. This method is tested by calculating the transmittance of a 7 mu m thick SmC^{* } LC cell for different azimuthal orientations of the cell between crossed polarisers. It is shown that the theoretical and measured orientations which give minimum transmittance are in good agreement. It is also shown that the

  8. Terrain-aided localization using electro-optical sensing (TALEOS)

    Science.gov (United States)

    Collins, Peter R. C.; Stephens, Arthur S.; Greenway, Phil; Deaves, Rob H.; Priestley, M. D. J.; Bullen, Mark

    1997-06-01

    The next generation of weapons systems will benefit from an array of new technologies which, when integrated, will provide the capability of accurately selecting the correct target. For example, target image features can be extracted from high resolution satellite data and this information can be fused with feature positions obtained from a weapon's imaging sensor. This will allow automatic target recognition to be performed. Terrain aided localization using electro-optical sensing (TALEOS) is a robust method of enhancing the performance of an imaging system through the exploitation of other sources of information. The primary image processing technique used in TALEOS is model-matching. The objective of model-matching is to discover the 3D position and orientation of an object (the model) with respect to the sensor reference frame by performing a match with corresponding features. In TALEOS, the model is derived from remotely sensed data and contains information about potentially observable features which might be extracted from the image. Embedded in this extended model is information about specific targets, including their known or estimated position, and features which characterize them. The Sowerby Research Center terrain model facility was used to gather realistic imagery. The terrain model is a 300:1 scale model of a 25 square kilometer area of real terrain. An overhead gantry system carries a video camera over the model enabling a wide variety of flight scenarios to be simulated experimentally. By a combination of special paint schemes and video inversion, pictures of the terrain model can provide a realistic simulation of infrared imagery. An image database was simulated using an overhead view of the model as if seen from a 'satellite' or reconnaissance aircraft. This imagery was utilized to evaluate the performance of the TALEOS technique for comparison with theoretical results. TALEOS integrates the data from the image processing subsystem with data from

  9. Electro-Optic Property Research of Blue Phase Liquid Crystals%蓝相液晶光电特性研究

    Institute of Scientific and Technical Information of China (English)

    倪水彬; 朱吉亮; 钟恩伟; 陆建钢

    2012-01-01

    蓝相液晶由于其特有的扭曲双螺旋结构,具有快速响应特性与宏观上的光学各向同性.通过聚合物稳定的方法,可以提升其热稳定性,但是也导致了驱动性能下降,磁滞效应增强等问题.文章通过研究手性掺杂和聚合物网络对蓝相液晶材料体系的作用以及不同温度下的磁滞效应,探索蓝相液晶器件光电特性的影响因子,为改善蓝相液晶材料的光电特性提供理论上的支持.%Blue phase liquid crystals (BPLCs) show fast response time and macroscopic optical isotropy due to their double twist cylinder structure. With polymer stabilization, the thermal stability of BPLCs can be improved dramatically. However, it induces some problems to the electro-optic properties of BPLCs material such as high driving voltage, hysteresis and so on. In this paper, different concentrations of chiral dopant, polymer network of the BPLC, and temperature effect are investigated to improve the electro-optic properties of BPLCs and analyze the mechanism that affect the electro-optic properties of the BPLCs device.

  10. Optimized design and fabrication of nanosecond response electro optic switch based on ultraviolet-curable polymers

    Institute of Scientific and Technical Information of China (English)

    赵旭亮; 岳远斌; 刘通; 孙健; 王希斌; 孙小强; 陈长鸣; 张大明

    2015-01-01

    A nanosecond response waveguide electro-optic (EO) switch based on ultraviolet (UV) sensitive polymers of Norland optical adhesive (NOA73) and Dispersed Red 1 (DR1) doped SU-8 (DR1/SU-8) is designed and fabricated. The absorption properties, refractive indexes, and surface morphologies of NOA73 film are characterized. The single-mode transmission condition is computed by the effective index method, and the percentage of optical field distributed in EO layer is optimized to be 93.78%. By means of spin-coating, thermal evaporation, photolithography, and inductively coupled plasma etching, a Mach–Zehnder inverted-rib waveguide EO switch with micro-strip line electrode is fabricated on a silicon substrate. Scanning electron microscope characterization proves the physic-chemical compatibility between NOA73 cladding and DR1/SU-8 core material. The optical transmission loss of the fabricated switch is measured to be 2.5 dB/cm. The rise time and fall time of switching are 3.199 ns and 2.559 ns, respectively. These results indicate that the inverted-rib wave-guide based on UV-curable polymers can effectively reduce the optical transmission loss and improve the time response performance of an EO switch.

  11. Development and characterization of thermally stable electro-optic polymers and devices (Presentation Recording)

    Science.gov (United States)

    Otomo, Akira; Aoki, Isao; Yamada, Chiyumi; Yamada, Toshiki

    2015-10-01

    Electro-optic (EO) polymers are key materials for next generation optical communications not only in wide area network but also in local area and storage area network because EO polymer modulator can be operated at fast speed more than 100 GHz with low energy consumption and can be miniaturized in combination with silicon photonics. In practical applications, thermal stability is one of the important issues to be considered for developing EO polymers. Since EO activity of the polymer is proportional to dipole orientation factor of the EO moieties, electric field assisted poling around glass transition temperature (Tg) of the polymer is necessary. However, the poled order of the molecules relaxes gradually at finite temperature, and then EO activity decreases after long period of time. We have successfully developed thermally stable EO polymers that have high-Tg up to 180 °C. They show excellent thermal stability with the Telcordia thermal test. Thermal stability is also characterized by thermally stimulated depolarization current (TSDC) measurement. Analyzing the TSDC, we can estimate the activation energy and relaxation time of polarization at any temperature. We will discuss thermal stability of the high-Tg EO polymers and devices.

  12. Damage analysis of CMOS electro-optical imaging system by a continuous wave laser

    Science.gov (United States)

    Yoon, Sunghee; Jhang, Kyung-Young; Shin, Wan-Soon

    2016-08-01

    EOIS (electro-optical imaging system) is vulnerable to laser beam because EOIS focuses the incident laser beam onto the image sensor via lens module. Accordingly, the laser-induced damage of EOIS is necessary to be identified for the counter-measure against the laser attack. In this study, the damage of CMOS EOIS and image sensor induced by CW (continuous wave) NIR (near infrared) laser was experimentally investigated. When the laser was emitted to CMOS EOIS, a temporary damage was occurred first such as flickering or dazzling and then a permanent damage was followed as the increase of laser irradiance and irradiation time. If the EIOS is composed of the optical equipment made of heatresistant material, laser beam can penetrate the lens module of EOIS without melting the lens and lens guide. Thus, it is necessary to investigate the damage of CMOS image sensor by the CW laser and we performed experimentally investigation of damage on the CMOS image sensor similar with case of CMOS EOIS. And we analyzed the experiment results by using OM (optical microscopy) and check the image quality through tomography. As the increase of laser irradiance and irradiation time, the permanent damage such as discoloration and breakdown were sequentially appeared.

  13. Design and investigation of a novel silicon/ferroelectric hybrid electro-optical microring modulator

    Science.gov (United States)

    Qi, Zhipeng; Hu, Guohua; Liu, Chang; Li, Lei; Yun, Binfeng; Zhang, Ruohu; Cui, Yiping

    2017-02-01

    A silicon (Si) and lanthanum-doped lead zirconium titanate (PLZT) hybrid microring modulator based on silicon-on-insulator (SOI) platform is designed theoretically and investigated numerically in this paper. The heterogeneous integration of PLZT film with Si material enables the waveguide to acquire both excellent electro-optical property and strong mode confinement capacity. Such hybrid microring modulator (100 μm in radius) has a PLZT rib-loaded cladding and is integrated with optimized tuning electrodes. The simulation results demonstrated that the Si/PLZT hybrid microring modulator could operate at 14 GHz with a relative high modulation efficiency (<0.8 V cm), which is much better than the other proposed Si/ferroelectric modulators. Meanwhile, under a driving voltage of 20 V, our modulator exhibits an extinction ratio of 32 dB at 1550.22 nm wavelength and a resonant wavelength tunability of 25 pm/V for TE mode. With these outstanding performances, the Si/PLZT hybrid microring modulator holds a great potential as a reliable on-chip device for optical communications and links.

  14. One-dimensional photonic crystal slot waveguide for silicon-organic hybrid electro-optic modulators.

    Science.gov (United States)

    Yan, Hai; Xu, Xiaochuan; Chung, Chi-Jui; Subbaraman, Harish; Pan, Zeyu; Chakravarty, Swapnajit; Chen, Ray T

    2016-12-01

    In an on-chip silicon-organic hybrid electro-optic (EO) modulator, the mode overlap with EO materials, in-device effective r33, and propagation loss are among the most critical factors that determine the performance of the modulator. Various waveguide structures have been proposed to optimize these factors, yet there is a lack of comprehensive consideration on all of them. In this Letter, a one-dimensional (1D) photonic crystal (PC) slot waveguide structure is proposed that takes all these factors into consideration. The proposed structure takes advantage of the strong mode confinement within a low-index region in a conventional slot waveguide and the slow-light enhancement from the 1D PC structure. Its simple geometry makes it robust to resist fabrication imperfections and helps reduce the propagation loss. Using it as a phase shifter in a Mach-Zehnder interferometer structure, an integrated silicon-organic hybrid EO modulator was experimentally demonstrated. The observed effective EO coefficient is as high as 490 pm/V. The measured half-wave voltage and length product is less than 1  V·cm and can be further improved. A potential bandwidth of 61 GHz can be achieved and further improved by tailoring the doping profile. The proposed structure offers a competitive novel phase-shifter design, which is simple, highly efficient, and with low optical loss, for on-chip silicon-organic hybrid EO modulators.

  15. Simulation of non-linear ultrasound fields

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Fox, Paul D.; Wilhjelm, Jens E.

    2002-01-01

    An approach for simulating non-linear ultrasound imaging using Field II has been implemented using the operator splitting approach, where diffraction, attenuation, and non-linear propagation can be handled individually. The method uses the Earnshaw/Poisson solution to Burgcrs' equation for the non......-linear ultrasound imaging in 3D using filters or pulse inversion for any kind of transducer, focusing, apodization, pulse emission and scattering phantom. This is done by first simulating the non-linear emitted field and assuming that the scattered field is weak and linear. The received signal is then the spatial...

  16. Efficient single sideband microwave to optical conversion using an electro-optical whispering gallery mode resonator

    CERN Document Server

    Rueda, Alfredo; Collodo, Michele C; Vogl, Ulrich; Stiller, Birgit; Schunk, Gerhard; Strekalov, Dmitry V; Marquardt, Christoph; Fink, Johannes M; Painter, Oskar; Leuchs, Gerd; Schwefel, Harald G L

    2016-01-01

    Linking classical microwave electrical circuits to the optical telecommunication band is at the core of modern communication. Future quantum information networks will require coherent microwave-to-optical conversion to link electronic quantum processors and memories via low-loss optical telecommunication networks. Efficient conversion can be achieved with electro-optical modulators operating at the single microwave photon level. In the standard electro-optic modulation scheme this is impossible because both, up- and downconverted, sidebands are necessarily present. Here we demonstrate true single sideband up- or downconversion in a triply resonant whispering gallery mode resonator by explicitly addressing modes with asymmetric free spectral range. Compared to previous experiments, we show a three orders of magnitude improvement of the electro-optical conversion efficiency reaching 0.1% photon number conversion for a 10GHz microwave tone at 0.42mW of optical pump power. The presented scheme is fully compatible...

  17. Single-shot electro-optic sampling of coherent transition radiation at the A0 Photoinjector

    CERN Document Server

    Maxwell, T J; Piot, P; Thurman-Keup, R

    2012-01-01

    Future collider applications and present high-gradient laser plasma wakefield accelerators operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. Potential applications in shot-to-shot, non-interceptive diagnostics continue to be pursued for live beam monitoring of collider and pump-probe experiments. Related to our developing work with electro-optic imaging, we present results on single-shot electro-optic sampling of the coherent transition radiation from bunches generated at the A0 photoinjector.

  18. Measurement of Sub-Picosecond Electron Bunches via Electro-Optic Sampling of Coherent Transition Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Timothy John [Northern Illinois U.

    2012-01-01

    Future collider applications as well as present high-gradient laser plasma wakefield accelerators and free-electron lasers operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. We present results on the single-shot electro-optic spectral decoding of coherent transition radiation from bunches generated at the Fermilab A0 photoinjector laboratory. A longitudinal double-pulse modulation of the electron beam is also realized by transverse beam masking followed by a transverse-to-longitudinal phase-space exchange beamline. Live profile tuning is demonstrated by upstream beam focusing in conjunction with downstream monitoring of single-shot electro-optic spectral decoding of the coherent transition radiation.

  19. Electro-optic dual-comb interferometry over 40-nm bandwidth

    CERN Document Server

    Duran, Vicente; Torres-Company, Victor

    2016-01-01

    Dual-comb interferometry is a measurement technique that uses two laser frequency combs to retrieve complex spectra in a line-by-line basis. This technique can be implemented with electro-optic frequency combs, offering intrinsic mutual coherence, high acquisition speed and flexible repetition-rate operation. A challenge with the operation of this kind of frequency comb in dual-comb interferometry is its limited optical bandwidth. Here, we use coherent spectral broadening and demonstrate electro-optic dual-comb interferometry over the entire telecommunications C band (200 lines covering ~ 40 nm, measured within 10 microseconds at 100 signal-to-noise ratio per spectral line). These results offer new prospects for electro-optic dual-comb interferometry as a suitable technology for high-speed broadband metrology, for example in optical coherence tomography or coherent Raman microscopy.

  20. Electro-Optical Imaging Microscopy of Dye-Doped Artificial Lipidic Membranes

    Science.gov (United States)

    Hajj, Bassam; De Reguardati, Sophie; Hugonin, Loïc; Le Pioufle, Bruno; Osaki, Toshihisa; Suzuki, Hiroaki; Takeuchi, Shoji; Mojzisova, Halina; Chauvat, Dominique; Zyss, Joseph

    2009-01-01

    Artificial lipidic bilayers are widely used as a model for the lipid matrix in biological cell membranes. We use the Pockels electro-optical effect to investigate the properties of an artificial lipidic membrane doped with nonlinear molecules in the outer layer. We report here what is believed to be the first electro-optical Pockels signal and image from such a membrane. The electro-optical dephasing distribution within the membrane is imaged and the signal is shown to be linear as a function of the applied voltage. A theoretical analysis taking into account the statistical orientation distribution of the inserted dye molecules allows us to estimate the doped membrane nonlinearity. Ongoing extensions of this work to living cell membranes are discussed. PMID:19948120

  1. Synthesis and Non-linear Optical(NLO) Properties of a Series of Alkoxysilane Derivative Chromophores

    Institute of Scientific and Technical Information of China (English)

    SHI Zuo-sen; ZHANG Xiao-long; WANG Shi-wei; ZHAO Li-sha; CUI Zhan-chen

    2009-01-01

    @@ 1 Introduction Nonlinear optical materials(NLO) have drawn a great intrest of some scholars and scientists in the last dacades because of their tremendous potential application in optoelectronic~[1]. The fabrication of efficient optoelectron devices is a challenging task because such systems need to meet the stringentable requirements for high optical quality and large and sustainable electro-optical(EO) response[2]. In pursuit of NLO materials with excellent optoelectronic property, a number of organic and inorganic materials have been investigated. Among them, organic-inorganic hybrid materials have drawn a great interest due to their good thermal stabilities, low optical loss and convenience in fabricating their thin films[3-6].

  2. SCALE FACTOR DETERMINATION METHOD OF ELECTRO-OPTICAL MODULATOR IN FIBER-OPTIC GYROSCOPE

    Directory of Open Access Journals (Sweden)

    A. S. Aleynik

    2016-05-01

    Full Text Available Subject of Research. We propose a method for dynamic measurement of half-wave voltage of electro-optic modulator as part of a fiber optic gyroscope. Excluding the impact of the angular acceleration o​n measurement of the electro-optical coefficient is achieved through the use of homodyne demodulation method that allows a division of the Sagnac phase shift signal and an auxiliary signal for measuring the electro-optical coefficient in the frequency domain. Method. The method essence reduces to decomposition of step of digital serrodyne modulation in two parts with equal duration. The first part is used for quadrature modulation signals. The second part comprises samples of the auxiliary signal used to determine the value of the scale factor of the modulator. Modeling is done in standalone model, and as part of a general model of the gyroscope. The applicability of the proposed method is investigated as well as its qualitative and quantitative characteristics: absolute and relative accuracy of the electro-optic coefficient, the stability of the method to the effects of angular velocities and accelerations, method resistance to noise in actual devices. Main Results. The simulation has showed the ability to measure angular velocity changing under the influence of angular acceleration, acting on the device, and simultaneous measurement of electro-optical coefficient of the phase modulator without interference between these processes. Practical Relevance. Featured in the paper the ability to eliminate the influence of the angular acceleration on the measurement accuracy of the electro-optical coefficient of the phase modulator will allow implementing accurate measurement algorithms for fiber optic gyroscopes resistant to a significant acceleration in real devices.

  3. Non-Linear Dynamics of Saturn's Rings

    Science.gov (United States)

    Esposito, L. W.

    2015-12-01

    results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects of the rings and can renew rings by shielding and recycling the material within them, depending on how long the mass is sequestered. We can ask: Are Saturn's rings a chaotic non-linear driven system?

  4. Unprecedented highest electro-optic coefficient of 226 pm/V for electro-optic polymer/TiO₂ multilayer slot waveguide modulators.

    Science.gov (United States)

    Jouane, Y; Chang, Y-C; Zhang, D; Luo, J; Jen, A K-Y; Enami, Y

    2014-11-03

    We investigated the electrical properties and optical quality of two layers a titanium dioxide (TiO₂) selective layer and a sol-gel silica cladding layer for use as coating layers for nonlinear optic (NLO) polymers in electro-optic (EO) polymer/TiO₂ multilayer slot waveguide modulators. We used a simple ellipsometric reflective technique developed by Teng and Man to measure the electro-optic (EO) coefficients of poled thin films of an EO polymer in an EO multilayer device. The Pockels coefficient was enhanced up to 226 and 198 pm/V at wavelengths of 1.31 and 1.55 μm, respectively, when optimally poled with TiO₂ and a sol-gel silica cladding.

  5. Electric field and temperature measurement using ultra wide bandwidth pigtailed electro-optic probes.

    Science.gov (United States)

    Bernier, Maxime; Gaborit, Gwenaël; Duvillaret, Lionel; Paupert, Alain; Lasserre, Jean-Louis

    2008-05-01

    We present pigtailed electro-optic probes that allow a simultaneous measurement of high frequency electric fields and temperature using a unique laser probe beam. This has been achieved by the development of a novel probe design associated with a fully automated servo-controlled optical bench, initially developed to stabilize the electric field sensor response. The developed electro-optic probes present a stable response in outdoors conditions over a time duration exceeding 1 h, a frequency bandwidth from kHz to tens of GHz with a sensitivity of 0.7 Vm(-1)Hz(-(1/2)), and a temperature accuracy of 40 mK.

  6. Bubbling effect in the electro-optic delayed feedback oscillator coupled network

    Science.gov (United States)

    Liu, Lingfeng; Lin, Jun; Miao, Suoxia

    2017-03-01

    Synchronization in the optical systems coupled network always suffers from bubbling events. In this paper, we numerically investigate the statistical properties of the synchronization characteristics and bubbling effects in the electro-optic delayed feedback oscillator coupled network with different coupling strength, delay time and gain coefficient. Furthermore, we compare our results with the synchronization properties of semiconductor laser (SL) coupled network, which indicates that the electro-optic delayed feedback oscillator can be better to suppress the bubbling effects in the synchronization of coupled network under the same conditions.

  7. Spherical Refractive Correction With an Electro-Optical Liquid Lens in a Double-Pass System

    Science.gov (United States)

    Sanàbria, F.; Díaz-Doutón, F.; Aldaba, M.; Pujol, J.

    2013-09-01

    In this study we show a novel double-pass configuration to correct the spherical refractive error by means of an electro-optical liquid lens.The proposed method enables spherical correction in the -12 D to +7 D range without movable parts using an electro-optical liquid lens.We have measured the optical performance of the spherical corrector in terms of power, pupil size and optical quality verifying that it fitsthe requirements to be applied to a double-pass system. We have also evaluated the performance of the proposed method in patients bycomparison with a conventional double-pass system using a Badal optometer.

  8. Systems engineering and analysis of electro-optical and infrared systems

    CERN Document Server

    Arrasmith, William Wolfgang

    2015-01-01

    Introduction to Electro-optic and Infrared (EO/IR) Systems Engineering?Radiation in the Visible and Infrared Parts of the Electromagnetic SpectrumRadiation SourcesThe Effect of the Atmosphere on Optical PropagationBasic OpticsOptical ModulationThe Detection of Optical RadiationNoise in the Optical Detection ProcessTechnical Performance Measures and Metrics of Optical DetectorsModern Detectors and their Measures of PerformanceThe Effects of Cooling on Optical Detector NoiseSignal and Image ProcessingElectro-Optic and Infrared Systems AnalysisLaser Imaging Systems?Spectral Imaging?LIDAR and LADA

  9. Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    CERN Document Server

    Pan, R; Lefevre, T; Gillepsie, WA; CERN. Geneva. ATS Department

    2015-01-01

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding(EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  10. Linear electro-optical properties of tetragonal BaTiO3

    Indian Academy of Sciences (India)

    P U Sastry

    2002-09-01

    Linear optical susceptibility and clamped linear electro-optical tensor coefficients of tetragonal BaTiO3 are calculated using a formalism based on bond charge theory. Calculated values are in close agreement with experimental data. The covalent Ti–O bonds constituting distorted TiO6 octahedral groups are found to be major contributors to the electro-optic coefficients making them more sensitive than the BaO12 groups for these properties. Orientations of chemical bonds play an important role in determining these properties.

  11. Processing Approach of Non-linear Adjustment Models in the Space of Non-linear Models

    Institute of Scientific and Technical Information of China (English)

    LI Chaokui; ZHU Qing; SONG Chengfang

    2003-01-01

    This paper investigates the mathematic features of non-linear models and discusses the processing way of non-linear factors which contributes to the non-linearity of a nonlinear model. On the basis of the error definition, this paper puts forward a new adjustment criterion, SGPE.Last, this paper investigates the solution of a non-linear regression model in the non-linear model space and makes the comparison between the estimated values in non-linear model space and those in linear model space.

  12. Non-linear elastic deformations

    CERN Document Server

    Ogden, R W

    1997-01-01

    Classic in the field covers application of theory of finite elasticity to solution of boundary-value problems, analysis of mechanical properties of solid materials capable of large elastic deformations. Problems. References.

  13. A new generation of previously unrealizable photonic devices as enabled by a unique electro-optic waveguide architecture

    Science.gov (United States)

    Davis, Scott R.; Rommel, Scott D.; Farca, George; Anderson, Michael H.

    2008-08-01

    A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

  14. Non-Linear Approximation of Bayesian Update

    KAUST Repository

    Litvinenko, Alexander

    2016-06-23

    We develop a non-linear approximation of expensive Bayesian formula. This non-linear approximation is applied directly to Polynomial Chaos Coefficients. In this way, we avoid Monte Carlo sampling and sampling error. We can show that the famous Kalman Update formula is a particular case of this update.

  15. Non-linear finite element modeling

    DEFF Research Database (Denmark)

    Mikkelsen, Lars Pilgaard

    The note is written for courses in "Non-linear finite element method". The note has been used by the author teaching non-linear finite element modeling at Civil Engineering at Aalborg University, Computational Mechanics at Aalborg University Esbjerg, Structural Engineering at the University...... on the governing equations and methods of implementing....

  16. Neural Networks for Non-linear Control

    DEFF Research Database (Denmark)

    Sørensen, O.

    1994-01-01

    This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process.......This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process....

  17. Neural Networks for Non-linear Control

    DEFF Research Database (Denmark)

    Sørensen, O.

    1994-01-01

    This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process.......This paper describes how a neural network, structured as a Multi Layer Perceptron, is trained to predict, simulate and control a non-linear process....

  18. Generalized non-linear strength theory and transformed stress space

    Institute of Scientific and Technical Information of China (English)

    YAO Yangping; LU Dechun; ZHOU Annan; ZOU Bo

    2004-01-01

    Based on the test data of frictional materials and previous research achievements in this field, a generalized non-linear strength theory (GNST) is proposed. It describes non-linear strength properties on the π-plane and the meridian plane using a unified formula, and it includes almost all the present non-linear strength theories, which can be used in just one material. The shape of failure function of the GNST is a smooth curve between the SMP criterion and the Mises criterion on the π-plane, and an exponential curve on the meridian plane. Through the transformed stress space based on the GNST, the combination of the GNST and various constitutive models using p and q as stress parameters can be realized simply and rationally in three-dimensional stress state.

  19. Broadband millimeter-wave electro-optic modulator using multi-patch antennas for pico-cell radar networks

    Science.gov (United States)

    Wijayanto, Yusuf Nur; Kanno, Atsushi; Kawanishi, Tetsuya

    2015-01-01

    An electro-optic (EO) modulator using multi patch antennas is proposed for broadband millimeter-wave bands in pico-cell radar networks. The proposed device is composed of multi patch antennas with a gap fabricated on a LiNbO3 crystal bonded with a low-k dielectric material. Multiple millimeter-wave operational frequencies can be received by the multi patch antennas and converting directly to lightwave signals through the Pockel effects of the LiNbO3 crystal. By adjusting the metal patch size for receiving with relatively close millimeter-wave frequencies, the bandwidth of the EO modulator can be enlarged. Based on that, bandwidth of over 30% in millimeter-wave bands can be achieved using the proposed device.

  20. Dielectric and electro-optical properties of polymer-stabilized liquid crystal. II. Polymer PiBMA dispersed in MBBA

    Science.gov (United States)

    Tripathi, Pankaj Kumar; Pande, Mukti; Singh, Shri

    2016-09-01

    In continuation of our earlier work (Pande et al. in Appl Phys A 122:217-226, 2016), we report the results of dielectric and electro-optical properties of pure MBBA and PSLC (polymer PiBMA dispersed in MBBA) systems. The polymer networks domains formed are found to be anisotropic and are oriented in the direction of electric field for both the planar and homeotropic alignment cells. The dielectric anisotropy, optical anisotropy, response time, threshold voltage, splay elastic constant and rotational viscosity were observed for both the LC and PSLC systems with electric field. The liquid crystal properties are affected significantly with increasing concentration of polymer in pure LC material. It has been observed that the polymer networks interaction plays a major role in changing the properties of PSLC system. The effect of dielectric loss and dielectric permittivity on both pure LC and PSLC systems is also discussed.

  1. Discrete spatial solitons formed in periodically poled lithium niobate by electro-optical effect

    Institute of Scientific and Technical Information of China (English)

    Xi Gu (顾希); Xianfeng Chen (陈险峰); Yuping Chen (陈玉萍); Yuxing Xia (夏宇兴); Yingli Chen (陈英礼)

    2003-01-01

    We report the numerical observation of discrete spatial solitons in a periodically poled lithium niobate waveguide array by applying an electrical field through electro-optical effect. We show that discrete spatial soliton can be controlled by applied voltage in the periodically poled lithium niobate.

  2. Recent Progress in Silicon Electro-optic Modulators for High Speed Applications

    Institute of Scientific and Technical Information of China (English)

    XIAO Xi; YU Jin-zhong

    2008-01-01

    Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.

  3. Optimization of electro-optic phase shifters for integrated optical phased arrays

    Science.gov (United States)

    Macik, Dwayne D.; Bravo, Tyler E.; Pentecost, Seeley M.; Espinal, Francisco A.; Madsen, Christi K.

    2017-05-01

    A low-loss, high-speed optical phased array (OPA) has been designed and fabricated. Two different platforms have been utilized in combination to leverage electro-optic (EO) tuning. A lithium niobate (LiNbO3) optical phased array was fabricated and used in conjunction with a silicon nitride (Si3N4) 8x8 waveguide array that condenses the output pitch and utilizes the TriplexTM waveguide technology. This OPA allows for the non-mechanical beam steering (NMBS) of 1550 nm light on an edge coupled optic platform and takes advantage of the high electro-optic coefficient and high speed capability of LiNbO3 for electro-optic phase tuning. This coupled OPA has an overall insertion loss of 3.5 dB which is advantageous to silicon-on-insulator OPAs that have shown overall insertion losses of 14 dB. To characterize and tune this device, a 3 lens imaging system was employed to produce both near- and far- field intensity patterns of the output of the OPA on a static image plane. At the image plane, a high resolution infrared camera was used to observe the resulting intensity pattern. The control software for tuning the OPA reads the intensity incident at a specified position on the detector array, and has a PWM interface to drive the electro-optic phase controls. Beam steering was accomplished using an iterative tuning algorithm.

  4. Quantum nondemolition measurement with a nonclassical meter input and an electro-optic enhancement

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Buchler, B.C.; Bachor, H.A.

    2002-01-01

    Optical quantum nondemolition measurements are performed using a beamsplitter with a nonclassical meter input and a electro-optic feedforward loop. The nonclassical meter input is provided by a stable 4.5 dB amplitude squeezed source generated by an optical parametric amplifier. We show...

  5. Electro-Optical Interference Laser Radiation Modulator (Elektroopticheskii Interfentsionnyi Modulyator Lazernogo Izlucheniya),

    Science.gov (United States)

    A modulator constructed on the basis of the Rozhdestvenskiy interferometer has been described. Characteristic static curves have been obtained in a... modulator working with one or two electro-optical crystals. A comparison of the interference and ordinary amplitude modulators has been given. (Author)

  6. Large-area Fabry-Perot modulator based on electro-optic polymers

    DEFF Research Database (Denmark)

    Benter, Nils; Bertram, Ralph Peter; Soergel, Elisabeth

    2006-01-01

    We present a large-area electro-optic Fabry-Perot modulator utilizing a photoaddressable bis-azo polymer placed between two dielectric mirrors with an open aperture of 2 cm. A modulation efficientcy of 1% at an effective modulation voltage of 20 V for a wavelength of 1.55 mymeter is demonstrated...

  7. Polymer stabilized liquid crystals: Topology-mediated electro-optical behavior and applications

    Science.gov (United States)

    Weng, Libo

    There has been a wide range of liquid crystal polymer composites that vary in polymer concentration from as little as 3 wt.% (polymer stabilized liquid crystal) to as high as 60 wt.% (polymer dispersed liquid crystals). In this dissertation, an approach of surface polymerization based on a low reactive monomer concentration about 1 wt.% is studied in various liquid crystal operation modes. The first part of dissertation describes the development of a vertical alignment (VA) mode with surface polymer stabilization, and the effects of structure-performance relationship of reactive monomers (RMs) and polymerization conditions on the electro-optical behaviors of the liquid crystal device has been explored. The polymer topography plays an important role in modifying and enhancing the electro-optical performance of stabilized liquid crystal alignment. The enabling surface-pinned polymer stabilized vertical alignment (PSVA) approach has led to the development of high-performance and fast-switching displays with controllable pretilt angle, increase in surface anchoring energy, high optical contrast and fast response time. The second part of the dissertation explores a PSVA mode with in-plane switching (IPS) and its application for high-efficiency and fast-switching phase gratings. The diffraction patterns and the electro-optical behaviors including diffraction efficiency and response time are characterized. The diffraction grating mechanism and performance have been validated by computer simulation. Finally, the advantages of surface polymerization approach such as good optical contrast and fast response time have been applied to the fringe-field switching (FFS) system. The concentration of reactive monomer on the electro-optical behavior of the FFS cells is optimized. The outstanding electro-optical results and mechanism of increase in surface anchoring strength are corroborated by the director field simulation. The density and topology of nanoscale polymer protrusions

  8. Foundations of the non-linear mechanics of continua

    CERN Document Server

    Sedov, L I

    1966-01-01

    International Series of Monographs on Interdisciplinary and Advanced Topics in Science and Engineering, Volume 1: Foundations of the Non-Linear Mechanics of Continua deals with the theoretical apparatus, principal concepts, and principles used in the construction of models of material bodies that fill space continuously. This book consists of three chapters. Chapters 1 and 2 are devoted to the theory of tensors and kinematic applications, focusing on the little-known theory of non-linear tensor functions. The laws of dynamics and thermodynamics are covered in Chapter 3.This volume is suitable

  9. Numerical simulation of non-linear phenomena in geotechnical engineering

    DEFF Research Database (Denmark)

    Sørensen, Emil Smed

    Geotechnical problems are often characterized by the non-linear behavior of soils and rock which are strongly linked to the inherent properties of the porous structure of the material as well as the presence and possible flow of any surrounding fluids. Dynamic problems involving such soil-fluid i...

  10. Computational Study of Linear and Nonlinear Optical Properties of Single Molecules and Clusters of Organic Electro-Optic Chromophores

    Science.gov (United States)

    Garrett, Kerry

    Organic electro-optic (OEO) materials integrated into silicon-organic hybrid (SOH) devices afford significant improvements in size, weight, power, and bandwidth (SWAP) performance of integrated electronic/photonic systems critical for current and next generation telecommunication, computer, sensor, transportation, and defense technologies. Improvement in molecular first hyperpolarizability, and in turn electro-optic activity, is crucial to further improvement in the performance of SOH devices. The timely preparation of new chromophores with improved molecular first hyperpolarizability requires theoretical guidance; however, common density functional theory (DFT) methods often perform poorly for optical properties in systems with substantial intramolecular charge transfer character. The first part of this dissertation describes the careful evaluation of popular long-range correction (LC) and range-separated hybrid (RSH) density functional theory (DFT) for definition of structure/function relationships crucial for the optimization of molecular first hyperpolarizability, beta. In particular, a benchmark set of well-characterized OEO chromophores is used to compare calculated results with the corresponding experimentally measured linear and nonlinear optical properties; respectively, the wavelength of the peak one-photon absorption energy, lambdamax, and beta. A goal of this work is to systematically determine the amount of exact exchange in LC/RSH-DFT methods required for accurately computing these properties for a variety OEO chromophores. High-level electron correlation (post-Hartree-Fock) methods are also investigated and compared with DFT. Included are results for the computation of beta using second-order Moller-Plesset perturbation theory (MP2) and the double-hybrid method, B2PLYP. The second part of this work transitions from single-molecule studies to computing bulk electronic and nonlinear optical properties of molecular crystals and isotropic ensembles of a

  11. Processing and Properties of High Performance Lead Free Electro-Optic Ceramics

    Science.gov (United States)

    Dupuy, Alexander Davis

    Electro-optic (EO) materials allow for the precise control of light using electrical signals, which has allowed for the advancement of an incredible array of photonic technologies such as laser systems and optical telecommunications. Most EO devices currently utilize single crystals, but high performance EO single crystals often have composition limitations since dopants can segregate and not all compositions can be grown using equilibrium restricted techniques. Bulk polycrystalline ceramic materials can potentially overcome such limitations and allow for the exploration of new EO systems. Due to the specific microstructures required for transparency, conventional processing techniques have difficulty in producing bulk polycrystalline EO ceramics. Reported here for the first time are the optical and EO properties of a new class of transparent lead free ceramic that outperforms EO materials in use today. This material is a barium titanate (BaTiO3) based solid solution, (1-x)Ba(Zr0.2Ti0.8)O 3-x(Ba0.7Ca0.3)TiO3 referred to here as BXT. The EO material was successfully processed using the Current Activated Pressure Assisted Densification (CAPAD) technique, commonly called Spark Plasma Sintering (SPS), which has been shown to be effective at consolidating optical materials. Using this technique along with a new powder synthesis method, it was possible to produce a transparent EO BXT ceramic with a highly dense and homogeneously reacted microstructure. Densified BXT shows a remarkable EO coefficient of 530 pm/V, which is superior not only to state of the art LiNbO3 crystals but also top-quality lead containing ferroelectric ceramics such as PLZT. This exceptional coefficient will allow for miniaturized EO systems with reduced operating voltages. The mechanisms behind the high EO performance in BXT were determined using additional EO and ferroelectric measurements. These measurements indicate that BXT undergoes a field induced structural evolution which heavily

  12. Novel electro-optical phase modulator based on GaInAs/InP modulation-doped quantum-well structures

    DEFF Research Database (Denmark)

    Thirstrup, C.

    1992-01-01

    A novel electro-optical phase modulator working at 1.55 µm is analyzed and proposed. It is shown by a numerical model that in a GaInAs/InP pn-nin-pn multiple-quantum-well waveguide structure, large optical phase modulation can be obtained at small intensity modulation and with improved performance...... compared to what is achieved in quantum confined Stark effect modulators of the same material system. The device proposed is based on a modulation of the quasi-Fermi energies of the electrons in the GaInAs quantum wells. This operational principle allows GHz modulation frequencies. Applied Physics Letters...

  13. Non-Linear Relativity in Position Space

    CERN Document Server

    Kimberly, D; Medeiros-Neto, J F; Kimberly, Dagny; Magueijo, João; Medeiros, João

    2003-01-01

    We propose two methods for obtaining the dual of non-linear relativity as previously formulated in momentum space. In the first we allow for the (dual) position space to acquire a non-linear representation of the Lorentz group independently of the chosen representation in momentum space. This requires a non-linear definition for the invariant contraction between momentum and position spaces. The second approach, instead, respects the linearity of the invariant contraction. This fully fixes the dual of momentum space and dictates a set of energy-dependent space-time Lorentz transformations. We discuss a variety of physical implications that would distinguish these two strategies. We also show how they point to two rather distinct formulations of theories of gravity with an invariant energy and/or length scale.

  14. Correlations and Non-Linear Probability Models

    DEFF Research Database (Denmark)

    Breen, Richard; Holm, Anders; Karlson, Kristian Bernt

    2014-01-01

    the dependent variable of the latent variable model and its predictor variables. We show how this correlation can be derived from the parameters of non-linear probability models, develop tests for the statistical significance of the derived correlation, and illustrate its usefulness in two applications. Under......Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations between...... certain circumstances, which we explain, the derived correlation provides a way of overcoming the problems inherent in cross-sample comparisons of the parameters of non-linear probability models....

  15. Non-linear (loop) quantum cosmology

    CERN Document Server

    Bojowald, Martin; Dantas, Christine C; Jaffe, Matthew; Simpson, David

    2012-01-01

    Inhomogeneous quantum cosmology is modeled as a dynamical system of discrete patches, whose interacting many-body equations can be mapped to a non-linear minisuperspace equation by methods analogous to Bose-Einstein condensation. Complicated gravitational dynamics can therefore be described by more-manageable equations for finitely many degrees of freedom, for which powerful solution procedures are available, including effective equations. The specific form of non-linear and non-local equations suggests new questions for mathematical and computational investigations, and general properties of non-linear wave equations lead to several new options for physical effects and tests of the consistency of loop quantum gravity. In particular, our quantum cosmological methods show how sizeable quantum corrections in a low-curvature universe can arise from tiny local contributions adding up coherently in large regions.

  16. Real-time digital signal processing for live electro-optic imaging.

    Science.gov (United States)

    Sasagawa, Kiyotaka; Kanno, Atsushi; Tsuchiya, Masahiro

    2009-08-31

    We present an imaging system that enables real-time magnitude and phase detection of modulated signals and its application to a Live Electro-optic Imaging (LEI) system, which realizes instantaneous visualization of RF electric fields. The real-time acquisition of magnitude and phase images of a modulated optical signal at 5 kHz is demonstrated by imaging with a Si-based high-speed CMOS image sensor and real-time signal processing with a digital signal processor. In the LEI system, RF electric fields are probed with light via an electro-optic crystal plate and downconverted to an intermediate frequency by parallel optical heterodyning, which can be detected with the image sensor. The artifacts caused by the optics and the image sensor characteristics are corrected by image processing. As examples, we demonstrate real-time visualization of electric fields from RF circuits.

  17. Novel Electro-Optical Modulator Utilizing GeO2-Doped Silica Waveguide

    Institute of Scientific and Technical Information of China (English)

    LI Jiusheng; JIA Dagong

    2009-01-01

    In order to achieve a modulator with broad bandwidth and perfect impedance match,a novel electro-optical modulator based on GeO2-doped silica waveguides on silicon substrate is designed.The finite element model of the whole electro-optical modulator is established by means of ANSYS.With the finite element method analysis,the performance of the novel modulator is predicted.The simulation reveals that the designed modulator operates with a product of 3 dB optical bandwidth and modulating length of 226.59 GHz-cm,and a characteristic impedance of 51.6 Ω at 1 550 nm wavelength.Moreover,the calculated electrical reflected power of coplanar waveguide electrode is below -20 dB in the frequency ranging from 45 MHz to 65 GHz.Therefore,the designed modulator has wide modulation bandwidth and perfect impedance match.

  18. High-speed and low-power electro-optical DSP coprocessor.

    Science.gov (United States)

    Tamir, Dan E; Shaked, Natan T; Wilson, Peter J; Dolev, Shlomi

    2009-08-01

    A fast, power-efficient electro-optical vector-by-matrix multiplier (VMM) architecture is presented. Careful design of an electrical unit supporting high-speed data transfer enables this architecture to overcome bottlenecks encountered by previous VMM architectures. Based on the proposed architecture, we present an electro-optical digital signal processing (DSP) coprocessor that can achieve a significant speedup of 2-3 orders of magnitude over existing DSP technologies and execute more than 16 teraflops. We show that it is feasible to implement the system using off-the-shelf components, analyze the performance of the architecture with respect to primitive DSP operations, and detail the use of the new architecture for several DSP applications.

  19. Paraxial Theory of Direct Electro-optic Sampling of the Quantum Vacuum

    Science.gov (United States)

    Moskalenko, A. S.; Riek, C.; Seletskiy, D. V.; Burkard, G.; Leitenstorfer, A.

    2015-12-01

    Direct detection of vacuum fluctuations and analysis of subcycle quantum properties of the electric field are explored by a paraxial quantum theory of ultrafast electro-optic sampling. The feasibility of such experiments is demonstrated by realistic calculations adopting a thin ZnTe electro-optic crystal and stable few-femtosecond laser pulses. We show that nonlinear mixing of a short near-infrared probe pulse with the multiterahertz vacuum field leads to an increase of the signal variance with respect to the shot noise level. The vacuum contribution increases significantly for appropriate length of the nonlinear crystal, short pulse duration, tight focusing, and a sufficiently large number of photons per probe pulse. If the vacuum input is squeezed, the signal variance depends on the probe delay. Temporal positions with a noise level below the pure vacuum may be traced with subcycle resolution.

  20. Femtosecond fibre laser stabilisation to an optical frequency standard using a KTP electro-optic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Nyushkov, B N [Novosibirsk State University, Novosibirsk (Russian Federation); Pivtsov, V S; Koliada, N A [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Kaplun, A B; Meshalkin, A B [S.S. Kutateladze Institute of Heat Physics, Siberian Division of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2015-05-31

    A miniature intracavity KTP-based electro-optic phase modulator has been developed which can be used for effective stabilisation of an optical frequency comb of a femtosecond erbiumdoped fibre laser to an optical frequency standard. The use of such an electro-optic modulator (EOM) has made it possible to extend the working frequency band of a phase-locked loop system for laser stabilisation to several hundred kilohertz. We demonstrate that the KTP-based EOM is sufficiently sensitive even at a small optical length, which allows it to be readily integrated into cavities of femtosecond fibre lasers with high mode frequency spacings (over 100 MHz). (extreme light fields and their applications)

  1. Nuclear reactor pulse calibration using a CdZnTe electro-optic radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Geuther, Jeffrey A. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Neihart, James L.; Riedel, Todd A. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Rojeski, Ronald A. [Nanometrics, Inc., 1550 Buckeye Drive, Milpitas, CA 95035 (United States); Saddler, Jeffrey L. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Schmidt, Aaron J.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-07-15

    A CdZnTe electro-optic radiation detector was used to calibrate nuclear reactor pulses. The standard configuration of the Pockels cell has collimated light passing through an optically transparent CdZnTe crystal located between crossed polarizers. The transmitted light was focused onto an IR sensitive photodiode. Calibrations of reactor pulses were performed using the CdZnTe Pockels cell by measuring the change in the photodiode current, repeated 10 times for each set of reactor pulses, set between 1.00 and 2.50 dollars in 0.50 increments of reactivity. - Highlights: Black-Right-Pointing-Pointer We demonstrated the first use of an electro-optic device to trace reactor pulses in real-time. Black-Right-Pointing-Pointer We examined the changes in photodiode current for different reactivity insertions. Black-Right-Pointing-Pointer Created a linear best fit line from the data set to predict peak pulse powers.

  2. Algebraic approach to electro-optic modulation of light: Exactly solvable multimode quantum model

    CERN Document Server

    Miroshnichenko, George P; Trifanov, Alexander I; Gleim, Artur V

    2016-01-01

    We theoretically study electro-optic light modulation based on the quantum model where the linear electro-optic effect and the externally applied microwave field result in the interaction between optical cavity modes. The model assumes that the number of interacting modes is finite and effects of the mode overlapping coefficient on the strength of the intermode interaction can be taken into account through dependence of the coupling coefficient on the mode characteristics. We show that, under certain conditions, the model is exactly solvable and, in the semiclassical approximation where the microwave field is treated as a classical mode, can be analyzed using the technique of the Jordan mappings for the su(2) Lie algebra. Analytical results are applied to study effects of light modulation on the frequency dependence of the photon counting rate. We also establish the conditions of validity of the semiclassical approximation by applying the methods of polynomially deformed Lie algebras for analysis of the model...

  3. INCREASING MEASUREMENT ACCURACY IN ELECTRO-OPTICAL METHOD FOR MEASURING VELOCITY OF DETONATION

    Directory of Open Access Journals (Sweden)

    Mario Dobrilović

    2014-12-01

    Full Text Available In addition to other detonation parameters detonation velocity is a value that provides indirect information on the strength i.e. brisance of an explosive and explosive performance. In addition to that, detonation velocity is a value which can be measured in a relatively simpler and more precise manner, by developed and accessible methods when compared to other detonation parameters Due to its simple use, compact instruments and satisfactory accuracy, electro-optical method of detonation velocity measurement is widely used. The paper describes the electro-optical measurement method and points out the factors that affect its accuracy. The accuracy of measurement is increased and measurement uncertainty is reduced by the measurement result analysis with the application of different measurement setups.

  4. Latest electro-optic and photonic devices for security and military applications

    Science.gov (United States)

    Jha, A. R.

    2006-09-01

    This paper reveals performance capabilities of state-of-the-art electro-optic and photonic devices, which are best suited for security and defense system applications. These devices can be used in battlefield, space surveillance, medical diagnosis, and detection of terrorist activities. Performance capabilities of fiber optic components for possible applications in WDM and DWDM systems are summarized. Photonic devices for covert military and security communication applications are identified with particular emphasis on performance and reliability. Performance parameters of Erbium-doped fiber amplifiers (EDFAs), Erbium-doped waveguide amplifiers (EDWAs), and optical hybrid amplifiers (OHAs) comprising of EDFAs and Raman amplifiers are discussed with emphasis on bandwidth, gain-flatness, data handling capability, channel capacity and cost-effectiveness. Performance parameters of very long wavelength infrared (VLWIR) detectors are summarized, which have potential applications in remote sensing and ballistic missile defense applications. Electro-optic and photonic devices best suited for security and defense applications are identified.

  5. Electro-optical Measurements of Ultrashort 45 MeV Electron Beam Bunches

    CERN Document Server

    Tsang, Thomas; Kowalski, L A; Larsen, R; Lazarus, D M; Nikas, D; Ozben, C; Semertzidis, Y K; Srinivasan-Rao, T

    2000-01-01

    We have measured the temporal duration of 45 MeV picosecond electron beam bunches using a noninvasive electro-optical (EO) technique. The amplitude of the EO modulation was found to increase linearly with electron beam charge and decrease inversely with distance from the electron beam. The risetime of the temporal signal was limited by our detection system to ~70ps. The EO signal due to ionization caused by the electrons traversing the EO crystal was also observed. It has a distinctively long decay time constant and signal polarity opposite to that due to the field induced by the electron beam. The electro-optical technique may be ideal for the measurement of bunch length of femtosecond, relativistic, high energy, charged, particle beams.

  6. Low-power Terahertz Time-Domain Spectroscopy with optimized electro-optical detection

    DEFF Research Database (Denmark)

    Gorenflo, Stefan; Hinkov, Iliyana; Lambrecht, Armin

    2005-01-01

    A Terahertz Time-Domain Spectroscopy (THz-TDS) system with electro-optical detector based on a ZnTe crystal is presented. The pump laser is a Ti:Sa laser with pulse duration of approx. 10 fs at a central wavelength of 800 nm. Using an optimized detection configuration, a signal-to-noise ratio bet...... better than 103 is achieved, applying an optical laser power of only 25mW. Several substances can be clearly distinguished on the basis of their specific THz absorption spectra.......A Terahertz Time-Domain Spectroscopy (THz-TDS) system with electro-optical detector based on a ZnTe crystal is presented. The pump laser is a Ti:Sa laser with pulse duration of approx. 10 fs at a central wavelength of 800 nm. Using an optimized detection configuration, a signal-to-noise ratio...

  7. Wideband Analog Transmission System Based on the External Intensity Electro-Optic Modulator

    Directory of Open Access Journals (Sweden)

    Jiri Svarny

    2016-01-01

    Full Text Available The work deals with design and integration of an analog electro-optic transmission system suitable for some specialized tasks of diagnostics and measurements. The system is based on principle of external intensity modulation of fiber guided laser radiation. Besides wideband and almost lossless transmission the system tolerates extreme length of the transmitting medium and ensures ultimate galvanic barrier between the input and output.

  8. Electro-optical measurements of 3D-stc detectors fabricated at ITC-irst

    Energy Technology Data Exchange (ETDEWEB)

    Zoboli, Andrea [INFN and Department of ICT, University of Trento, via Sommarive, 14 - 38050 Povo di Trento (Italy)], E-mail: zoboli@dit.unitn.it; Boscardin, Maurizio [ITC-irst, Microsystems Division, via Sommarive, 18 - 38050 Povo di Trento (Italy); Bosisio, Luciano [INFN and Department of Physics, University of Trieste, via A. Valerio, 2 - 34127 Trieste (Italy); Dalla Betta, Gian-Franco [INFN and Department of ICT, University of Trento, via Sommarive, 14 - 38050 Povo di Trento (Italy); Piemonte, Claudio; Pozza, Alberto; Ronchin, Sabina; Zorzi, Nicola [ITC-irst, Microsystems Division, via Sommarive, 18 - 38050 Povo di Trento (Italy)

    2007-12-11

    In the past two years 3D silicon radiation detectors have been developed at ITC-irst (Trento, Italy). As a first step toward full 3D devices, simplified structures featuring columnar electrodes of one doping type only were fabricated. This paper reports the electro-optical characterization of 3D test diodes made with this approach. Experimental results and TCAD simulations provide good insight into the charge collection mechanism and response speed limitation of these structures.

  9. Electro-optical cavity-dumped Ce:Nd:YAG laser for aesthetic medicine

    Science.gov (United States)

    Lv, Yuandong; Liu, Jiaqi; Hao, Lijun

    2012-11-01

    An electro-optical cavity-dumped 20 Hz Ce:Nd:YAG laser with an optimized thermal-insensitive concavo-convex cavity for aesthetic medicine was demonstrated. The pulse width remained constant at 6.0 ns. The maximum output energy and peak power were 120 mJ and 20 MW, respectively. The average output energy was very stable. The fluctuations of average output energy within 6 cycles and 10 min were 0.89% and 7.9%, respectively.

  10. Photoluminescence and electro-optic properties of small (25-35 nm diameter) quantum boxes

    Science.gov (United States)

    Davis, L.; Ko, K. K.; Li, W.-Q.; Sun, H. C.; Lam, Y.; Brock, T.; Pang, S. W.; Bhattacharya, P. K.; Rooks, M. J.

    1993-05-01

    The luminescence and electro-optic properties of buried 25-35 nm quantum boxes have been measured. The quantum boxes were defined by a combination of molecular beam epitaxial growth and regrowth, electron beam lithography, and dry etching. The photoluminescence from 35 nm boxes shows a blue shift of about 15 meV compared to the bulk luminescence and an enhancement, taking into account the fill factor. An enhanced effective linear electrooptic coefficient is observed for the quantum boxes.

  11. A Community Format for Electro-Optic Space Situational Awareness (EOSSA) Data Products

    Science.gov (United States)

    2014-09-01

    Awareness (SSA) community. With the increase in the number of Electro-Optical (EO) sensors collecting photometric, radiometric , and spectroscopic data...Optical (EO) sensors collecting photometric, radiometric , and spectroscopic data on man-made Resident Space Objects (RSOs) for Space Situational...comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE SEP 2014 2. REPORT TYPE 3. DATES

  12. Electro-Optical System Simulation and Performance Prediction Extensions to EODES

    Science.gov (United States)

    2010-01-01

    performed a preliminary validation of the Streak Tube Imaging Lidar (STIL) model using data from an August 2001 field test of electro-optical imaging...situations. It was also determined that the long fall time (see Fig. 2) of the proposed photodetector did adversely impact image quality. These... Lidar (STIL) sensor showed good agreement between EODES simulations and actual sensor imagery. In addition, the image quality predicted by EODES

  13. Optimum design of a polymer electro-optic microring resonator switch

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Novel transfer functions are presented for a polymer electro-optic microring resonator switches. The resonating process of the light in the microring is simulated using the formulas. Then the optimization of the structural parameters is performed,and the characteristics are analyzed, such as the resonance time, output spectrum, operation voltage, insertion loss and crosstalk were analyzed. The simulation results show that the designed device exhibits favorable switching functions.

  14. An Electro-Optic Modulator Based on GeO2-Doped Silica Ridge Waveguides with Thermal Poling

    Institute of Scientific and Technical Information of China (English)

    曹霞; 何赛灵

    2003-01-01

    A Mach-Zehnder electro-optic modulator is designed and fabricated based on upper-clad GeO2-doped silica ridge waveguides with thermal poling. The electro-optic coefficient obtained is about 0.05 pm/V and is polarizationinsensitive. An extinction ratio of over 17dB is achieved. The transmission loss of the modulator for the TE mode is 2-3 dB higher than that for the TM mode after the poling.

  15. On-chip electro-optic tuning of a lithium niobate microresonator with integrated in-plane microelectrodes

    CERN Document Server

    Wang, Min; Fang, Zhiwei; Liao, Yang; Wang, Peng; CHu, Wei; Qiao, Lingling; Lin, Jintian; Fang, Wei; Cheng, Ya

    2016-01-01

    We demonstrate electro-optic tuning of an on-chip lithium niobate microresonator with integrated in-plane microelectrodes. First two metallic microelectrodes on the substrate were formed via femtosecond laser process. Then a high-Q lithium niobate microresonator located between the microelectrodes was fabricated by femtosecond laser direct writing accompanied by focused ion beam milling. Due to the efficient structure designing, high electro-optical tuning coefficient of 3.41 pm/V was observed.

  16. Novel electro-optical coupling technique for magnetic resonance-compatible positron emission tomography detectors.

    Science.gov (United States)

    Olcott, Peter D; Peng, Hao; Levin, Craig S

    2009-01-01

    A new magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL) diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  17. Novel Electro-Optical Coupling Technique for Magnetic Resonance-Compatible Positron Emission Tomography Detectors

    Directory of Open Access Journals (Sweden)

    Peter D. Olcott

    2009-03-01

    Full Text Available A new magnetic resonance imaging (MRI-compatible positron emission tomography (PET detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  18. Optical modulation techniques for analog signal processing and CMOS compatible electro-optic modulation

    Science.gov (United States)

    Gill, Douglas M.; Rasras, Mahmoud; Tu, Kun-Yii; Chen, Young-Kai; White, Alice E.; Patel, Sanjay S.; Carothers, Daniel; Pomerene, Andrew; Kamocsai, Robert; Beattie, James; Kopa, Anthony; Apsel, Alyssa; Beals, Mark; Mitchel, Jurgen; Liu, Jifeng; Kimerling, Lionel C.

    2008-02-01

    Integrating electronic and photonic functions onto a single silicon-based chip using techniques compatible with mass-production CMOS electronics will enable new design paradigms for existing system architectures and open new opportunities for electro-optic applications with the potential to dramatically change the management, cost, footprint, weight, and power consumption of today's communication systems. While broadband analog system applications represent a smaller volume market than that for digital data transmission, there are significant deployments of analog electro-optic systems for commercial and military applications. Broadband linear modulation is a critical building block in optical analog signal processing and also could have significant applications in digital communication systems. Recently, broadband electro-optic modulators on a silicon platform have been demonstrated based on the plasma dispersion effect. The use of the plasma dispersion effect within a CMOS compatible waveguide creates new challenges and opportunities for analog signal processing since the index and propagation loss change within the waveguide during modulation. We will review the current status of silicon-based electrooptic modulators and also linearization techniques for optical modulation.

  19. Electro-optic architecture (EOA) for sensors and actuators in aircraft propulsion systems

    Science.gov (United States)

    Glomb, W. L., Jr.

    1989-06-01

    Results of a study to design an optimal architecture for electro-optical sensing and control in advanced aircraft and space systems are described. The propulsion full authority digital Electronic Engine Control (EEC) was the focus for the study. The recommended architecture is an on-engine EEC which contains electro-optic interface circuits for fiber-optic sensors on the engine. Size and weight are reduced by multiplexing arrays of functionally similar sensors on a pair of optical fibers to common electro-optical interfaces. The architecture contains common, multiplex interfaces to seven sensor groups: (1) self luminous sensors; (2) high temperatures; (3) low temperatures; (4) speeds and flows; (5) vibration; (6) pressures; and (7) mechanical positions. Nine distinct fiber-optic sensor types were found to provide these sensing functions: (1) continuous wave (CW) intensity modulators; (2) time division multiplexing (TDM) digital optic codeplates; (3) time division multiplexing (TDM) analog self-referenced sensors; (4) wavelength division multiplexing (WDM) digital optic code plates; (5) wavelength division multiplexing (WDM) analog self-referenced intensity modulators; (6) analog optical spectral shifters; (7) self-luminous bodies; (8) coherent optical interferometers; and (9) remote electrical sensors. The report includes the results of a trade study including engine sensor requirements, environment, the basic sensor types, and relevant evaluation criteria. These figures of merit for the candidate interface types were calculated from the data supplied by leading manufacturers of fiber-optic sensors.

  20. Ultrahigh Q whispering gallery mode electro-optic resonators on a silicon photonic chip.

    Science.gov (United States)

    Soltani, Mohammad; Ilchenko, Vladimir; Matsko, Andrey; Savchenkov, Anatoliy; Schlafer, John; Ryan, Colm; Maleki, Lute

    2016-09-15

    Crystalline whispering gallery mode (WGM) electro-optic resonators made of LiNbO3 and LiTaO3 are critical for a wide range of applications in nonlinear and quantum optics, as well as RF photonics, due to their remarkably ultrahigh Q(>108) and large electro-optic coefficient. Achieving efficient coupling of these resonators to planar on-chip optical waveguides is essential for any high-yield and robust practical applications. However, it has been very challenging to demonstrate such coupling while preserving the ultrahigh Q properties of the resonators. Here, we show how the silicon photonic platform can overcome this long-standing challenge. Silicon waveguides with appropriate designs enable efficient and strong coupling to these WGM electro-optic resonators. We discuss various integration architectures of these resonators onto a silicon chip and experimentally demonstrate critical coupling of a planar Si waveguide and an ultrahigh QLiTaO3 resonator (Q∼108). Our results show a promising path for widespread and practical applications of these resonators on a silicon photonic platform.

  1. A robust fibre laser system for electro-optic electron bunch profile measurements at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Wissmann, Laurens-Georg

    2012-08-15

    For the electro-optic measurement of electron bunch profiles at FLASH a robust ytterbium doped fibre laser (YDFL) system has been developed consisting of a laser oscillator and a two-staged amplifier. The oscillator is designed to meet the specifications of high reliability and low noise operation. The amplifier makes use of tailored nonlinearity to enhance the spectral bandwidth of the output laser pulses. Active repetition rate control enables sub-picosecond synchronisation of the laser to the accelerator reference RF. Using a two-stage gating scheme the output pulse train repetition rate is adopted to the accelerator repetition rate. An experimental site used for electro-optic electron bunch diagnostics has been redesigned to support single-shot bunch profile measurements based on spectral decoding. An existing bunch profile monitor with a similar laser system was upgraded and electro-optic bunch profile measurements were conducted, allowing for a comparison with measurements done with other longitudinal electron bunch diagnostics and with former measurements.

  2. Non-Linear Logging Parameters Inversion

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The non-linear logging parameters inversion is based on the field theory, information optimization and predication theory. It uses seismic charaoters,geological model and logging data as a restriction to inverse 2D, 3D logging parameters data volume. Using this method,

  3. Non linear system become linear system

    Directory of Open Access Journals (Sweden)

    Petre Bucur

    2007-01-01

    Full Text Available The present paper refers to the theory and the practice of the systems regarding non-linear systems and their applications. We aimed the integration of these systems to elaborate their response as well as to highlight some outstanding features.

  4. Oscillatons formed by non linear gravity

    CERN Document Server

    Obregón, O; Schunck, F E; Obregon, Octavio; Schunck, Franz E.

    2004-01-01

    Oscillatons are solutions of the coupled Einstein-Klein-Gordon (EKG) equations that are globally regular and asymptotically flat. By means of a Legendre transformation we are able to visualize the behaviour of the corresponding objects in non-linear gravity where the scalar field has been absorbed by means of the conformal mapping.

  5. Correlations and Non-Linear Probability Models

    DEFF Research Database (Denmark)

    Breen, Richard; Holm, Anders; Karlson, Kristian Bernt

    2014-01-01

    Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations betwee...... certain circumstances, which we explain, the derived correlation provides a way of overcoming the problems inherent in cross-sample comparisons of the parameters of non-linear probability models.......Although the parameters of logit and probit and other non-linear probability models are often explained and interpreted in relation to the regression coefficients of an underlying linear latent variable model, we argue that they may also be usefully interpreted in terms of the correlations between...... the dependent variable of the latent variable model and its predictor variables. We show how this correlation can be derived from the parameters of non-linear probability models, develop tests for the statistical significance of the derived correlation, and illustrate its usefulness in two applications. Under...

  6. Controller reconfiguration for non-linear systems

    NARCIS (Netherlands)

    Kanev, S.; Verhaegen, M.

    2000-01-01

    This paper outlines an algorithm for controller reconfiguration for non-linear systems, based on a combination of a multiple model estimator and a generalized predictive controller. A set of models is constructed, each corresponding to a different operating condition of the system. The interacting m

  7. Theoretical study of second-order non-linear optical properties of pyrromethene dyes for photonic application

    Energy Technology Data Exchange (ETDEWEB)

    Acebal, P; Blaya, S; Carretero, L [Departamento de Ciencia y Tecnologia de Materiales, Universidad Miguel Hernandez, Avenida Ferrocarril s/n, Apartado 032002, Edificio Torrevaillo, Elx (Alicante) (Spain)

    2003-06-28

    Second-order non-linear optical properties and the ground state dipole moment of 2-, 6-, and 8-substituted dipyrromethene-BF{sub 2} complexes were evaluated using ab initio quantum mechanical methods and compared with those of a standard push-pull chromophore. The theoretical values obtained are discussed in terms of the different contributions of each spatial region using the electron density derivatives with respect to an applied electric field. As results, an origin for the second hyperpolarizability and a methodology for improving the performance of these compounds are proposed. The two-level model has been use to study the electro-optic properties of the substituted dipyrromethene-BF{sub 2} complexes, and the applicability of this method has been discussed in terms of the electron density derivatives.

  8. Non-linear optical processes involving excited subbands in laser-dressed quantum wires with triangular cross-section

    Science.gov (United States)

    Radu, A.; Duque, C. A.

    2015-08-01

    The conduction subband structure of a triangular cross-section GaAs/AlGaAs quantum well wire under intense laser field is theoretically investigated by taking into account a finite confining potential. The calculation of the subband energy levels is based on a two-dimensional finite element method within the effective mass approximation. It is shown that a transversally polarized laser field non-uniformly shifts the subband energy levels and could be used for tuning the intersubband transitions and altering the related optical susceptibilities. We found that the non-resonant laser field allows the magnification and the red- or blueshift of the third-order non-linear susceptibility peaks for particular polarizations of the pump light and proper laser parameter values. The effects of the laser dressing field on the intersubband third harmonic generation and quadratic electro-optical process are discussed.

  9. Non-linear dendrites can tune neurons

    Directory of Open Access Journals (Sweden)

    Romain Daniel Cazé

    2014-03-01

    Full Text Available A signature of visual, auditory, and motor cortices is the presence of neurons tuned to distinct features of the environment. While neuronal tuning can be observed in most brain areas, its origin remains enigmatic, and new calcium imaging data complicate this problem. Dendritic calcium signals, in a L2/3 neuron from the mouse visual cortex, display a wide range of tunings that could be different from the neuronal tuning (Jia et al 2010. To elucidate this observation we use multi-compartmental models of increasing complexity, from a binary to a realistic biophysical model of L2/3 neuron. These models possess non-linear dendritic subunits inside which the result of multiple excitatory inputs is smaller than their arithmetic sum. While dendritic non-linear subunits are ad-hoc in the binary model, non-linearities in the realistic model come from the passive saturation of synaptic currents. Because of these non-linearities our neuron models are scatter sensitive: the somatic membrane voltage is higher when presynaptic inputs target different dendrites than when they target a single dendrite. This spatial bias in synaptic integration is, in our models, the origin of neuronal tuning. Indeed, assemblies of presynaptic inputs encode the stimulus property through an increase in correlation or activity, and only the assembly that encodes the preferred stimulus targets different dendrites. Assemblies coding for the non-preferred stimuli target single dendrites, explaining the wide range of observed tunings and the possible difference between dendritic and somatic tuning. We thus propose, in accordance with the latest experimental observations, that non-linear integration in dendrites can generate neuronal tuning independently of the coding regime.

  10. Electro-optical phenomena based on ionic liquids in an optofluidic waveguide.

    Science.gov (United States)

    He, Xiaodong; Shao, Qunfeng; Cao, Pengfei; Kong, Weijie; Sun, Jiqian; Zhang, Xiaoping; Deng, Youquan

    2015-03-01

    An optofluidic waveguide with a simple two-terminal electrode geometry, when filled with an ionic liquid (IL), forms a lateral electric double-layer capacitor under a direct current (DC) electric field, which allows the realization of an extremely high carrier density in the vicinity of the electrode surface and terminals to modulate optical transmission at room temperature under low voltage operation (0 to 4 V). The unique electro-optical phenomenon of ILs was investigated at three wavelengths (663, 1330 and 1530 nm) using two waveguide geometries. Strong electro-optical modulations with different efficiencies were observed at the two near-infrared (NIR) wavelengths, while no detectable modulation was observed at 663 nm. The first waveguide geometry was used to investigate the position-dependent modulation along the waveguide; the strongest modulation was observed in the vicinity of the electrode terminal. The modulation phase is associated with the applied voltage polarity, which increases in the vicinity of the negative electrode and decreases at the positive electrode. The second waveguide geometry was used to improve the modulation efficiency. Meanwhile, the electro-optical modulations of seven ILs were compared at an applied voltage ranging from ±2 V to ±3.5 V. The results reveal that the modulation amplitude and response speed increase with increasing applied voltage, as well as the electrical conductivity of ILs. Despite the fact that the response speed isn't fast due to the high ionic density of ILs, the modulation amplitude can reach up to 6.0 dB when a higher voltage (U = ±3.5 V) is applied for the IL [Emim][BF4]. Finally, the physical explanation of the phenomenon was discussed. The effect of the change in IL structure on the electro-optical phenomena was investigated in another new experiment. The results reveal that the electro-optical phenomenon is probably caused mainly by the change in carrier concentration (ion redistribution near charged

  11. NON-LINEAR FINITE ELEMENT MODELING OF DEEP DRAWING PROCESS

    Directory of Open Access Journals (Sweden)

    Hasan YILDIZ

    2004-03-01

    Full Text Available Deep drawing process is one of the main procedures used in different branches of industry. Finding numerical solutions for determination of the mechanical behaviour of this process will save time and money. In die surfaces, which have complex geometries, it is hard to determine the effects of parameters of sheet metal forming. Some of these parameters are wrinkling, tearing, and determination of the flow of the thin sheet metal in the die and thickness change. However, the most difficult one is determination of material properties during plastic deformation. In this study, the effects of all these parameters are analyzed before producing the dies. The explicit non-linear finite element method is chosen to be used in the analysis. The numerical results obtained for non-linear material and contact models are also compared with the experiments. A good agreement between the numerical and the experimental results is obtained. The results obtained for the models are given in detail.

  12. Electro-optic switching in iron oxide nanoparticle embedded paramagnetic chiral liquid crystal via magneto-electric coupling

    Energy Technology Data Exchange (ETDEWEB)

    Goel, Puja, E-mail: pujagoel@gmail.com [Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 110012 (India); Arora, Manju; Biradar, Ashok M. [Materials Physics and Engineering Division, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India)

    2014-03-28

    The variation in optical texture, electro-optic, and dielectric properties of iron oxide nanoparticles (NPs) embedded ferroelectric liquid crystal (FLC) with respect to change in temperature and electrical bias conditions are demonstrated in the current investigations. Improvement in spontaneous polarization and response time in nanocomposites has been attributed to magneto-electric (ME) coupling resulting from the strong interaction among the ferromagnetic nanoparticle's exchange field (due to unpaired e{sup −}) and the field of liquid crystal molecular director. Electron paramagnetic resonance spectrum of FLC material gives a broad resonance signal with superimposed components indicating the presence of a source of spin. This paramagnetic behavior of host FLC material had been a major factor in strengthening the guest host interaction by giving an additional possibility of (a) spin-spin interaction and (b) interactions between magnetic-dipole and electric-dipole moments (ME effects) in the composite materials. Furthermore, the phenomenon of dielectric and static memory effect in these composites are also observed which yet again confirms the coupling of magnetic NP's field with FLC's director orientation. We therefore believe that such advanced soft materials holding the optical and electrical properties of conventional LCs with the magnetic and electronic properties of ferromagnetic nanoparticles are going to play a key role in the development of futuristic multifunctional optical devices.

  13. Electro-optical properties of dislocations in silicon and their possible application for light emitters

    Energy Technology Data Exchange (ETDEWEB)

    Arguirov, Tzanimir Vladimirov

    2007-10-14

    This thesis addresses the electro-optical properties of silicon, containing dislocations. The work demonstrates that dislocation specific radiation may provide a means for optical diagnostics of solar cell grade silicon. It provides insight into the mechanisms governing the dislocation recombination activity, their radiation, and how are they influenced by other defects present in silicon. We demonstrate that photoluminescence mapping is useful for monitoring the recombination activity in solar cell grade silicon and can be applied for identification of contaminants, based on their photoluminescence signatures. It is shown that the recombination at dislocations is strongly influenced by the presence of metals at the dislocation sites. The dislocation radiation activity correlates with their electrical activity. It is shown that the dislocation and band-to-band luminescence are essentially anti-correlated. {beta}FeSi{sub 2} precipitates, with a luminescence at 0.8 eV, were detected within the grains of block cast materials. They exhibit a characteristic feature of quantum dots, namely blinking. The second aspect of the thesis concerns the topic of silicon based light emitters for on-chip optical interconnects. The goal is an enhancement of sub-band-gap or band-to-band radiation by controlled formation of dislocation-rich areas in microelectronics-grade silicon as well as understanding of the processes governing such enhancement. For light emitters based on band-to-band emission it is shown, that internal quantum efficiency of nearly 2 % can be achieved, but the emission is essentially generated in the bulk of the wafer. On the other hand, light emitters utilizing the emission from dislocation-rich areas of a well localized wafer depth were explored. Three different methods for reproducible formation of a dislocation-rich region beneath the wafer surface were investigated and evaluated in view of their room temperature sub-band-gap radiation: (1) silicon implantation

  14. Transparent conducting oxides for electro-optical plasmonic modulators

    DEFF Research Database (Denmark)

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

    2015-01-01

    ), or optical materials with metal-like behavior,have recently attracted a lot of attention due to thepromise they hold to enable low-loss, tunable, CMOScompatibledevices for photonic technologies. In this review,we provide a systematic overview of various compactoptical modulator designs that utilize a class...... and their working characteristics, suchas their extinction ratio, compactness, bandwidth, andlosses, is performed identifying the most promising designs....

  15. An electro-optical timing diagnostic for pump-probe experiments at the free-electron laser in Hamburg FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Azima, Armin

    2009-07-15

    Femtosecond pump-probe experiments have extensively been used to follow atomic and molecular motion in time. The very intense extreme ultraviolet XUV light of the Free electron LASer in Hamburg FLASH facility allows to investigate fundamental processes such as direct one or few photon inner shell ionizations. A supplementary Ti:Sapphire near infrared femtosecond laser system allows to perform two-color pump-probe experiments with FLASH involving intense laser fields of hugely different photon energies. Within this work a bunch arrival measurement system has been built, which assists these two-color pump-probe experiments to reduce the temporal jitter of FLASH and to increase the temporal resolution. The diagnostic is based upon an electro-optical detection scheme and measures the relative arrival time between the Ti:Sapphire femtosecond pulse and the electron bunch, which generates the self-amplified by stimulated emission SASE XUV pulse in the undulator section of FLASH. Key feature of the diagnostic is a 150 m long glass fiber pulse transport line, which inflicts non-linear dispersion. A dispersion control system to compensate for this higher order dispersion has been developed including the control and programming of a spatial light phase modulator. It was possible to transport a 90 fs FWHM short near infrared femtosecond laser pulse Fourier limited by the dispersion compensated glass fiber. The electro-optical signal induced by the FLASH electron bunch was generated, characterized and optimized. The signal features beside the designated bunch arrival timing capability the additional possibility to measure the longitudinal electron bunch density distribution of an arbitrary bunch of FLASH in a single shot with a temporal resolution of below 100 fs RMS. Timing and bunch analysis capabilities of the developed diagnostic have been cross-checked with other comparable diagnostics at FLASH like the transversal deflecting cavity structure named LOLA. Finally, the

  16. Stability analysis and non-linear behaviour of structural systems using the complex non-linear modal analysis (CNLMA)

    OpenAIRE

    Sinou, Jean-Jacques; Thouverez, Fabrice; Jezequel, Louis

    2006-01-01

    International audience; Herein, a novel non-linear procedure for producing non-linear behaviour and stable limit cycle amplitudes of non-linear systems subjected to super-critical Hopf bifurcation point is presented. This approach, called Complex Non-Linear Modal Analysis (CNLMA), makes use of the non-linear unstable mode which governs the non-linear dynamic of structural systems in unstable areas. In this study, the computational methodology of CNLMA is presented for the systematic estimatio...

  17. Nanomaterials for LightManagement in Electro-Optical Devices

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Vo-Van [Concordia University, Montréal, Québec, H4B 1R6, Canada; Singh, Jai [Charles Darwin University, Darwin, Australia; Tanemura, Sakae [Japan Fine Ceramics Center, Nagoya, Japan; Hu, Michael Z. [ORNL

    2012-01-01

    In the past decade, nanostructured materials and nanoparticles have emerged as the necessary ingredients for electrooptical applications and enhancement of device performance, in particular by making use of the light management aspects of the nanomaterials. The application areas that are being transformed profoundly include smart coating devices (e.g., electrochromic, photochromic, and thermochromic devices), solar energy, and sensing. Despite the large volume of work in the past on smart coating devices, and in particular on electrochromic devices and thermochromic fenestrations, for optical transmission or reflection control, applications remain limited because of slow response time and nonuniformity in the case of large surfaces. Recent works in the field indicate that nanostructured electrochromic coatings would be an integral part of the solution to the above problem. One aspect that can thus be focused on would be the fabrication and characterization of the nanostructured smart coating materials and their compatibility with other layers in the overall smart coating device. In the area of solar photovoltaics, nanomaterials have been used in designing light-trapping schemes for inorganic as well as organic solar cells. One particular category of solar cells that has attracted much interest is the plasmonic solar cells in which metallic nanoparticles are incorporated, helping in enhancing their energy conversion efficiency. Nanostructured solar cells would eventually develop into a 'game changing' technology for making solar cells that are affordable and highly efficient, providing a sizeable alternative energy source for our ever-increasing energy needs. Sensors based on the optical properties of constituting nanostructures and nanoparticles also form a most interesting class of bio- and electrochemical sensing devices. The possibility of synthetizing nanoparticles and structures of specifically desired sizes and shapes has indeed opened a whole new

  18. Non-Linear Dynamics and Fundamental Interactions

    CERN Document Server

    Khanna, Faqir

    2006-01-01

    The book is directed to researchers and graduate students pursuing an advanced degree. It provides details of techniques directed towards solving problems in non-linear dynamics and chos that are, in general, not amenable to a perturbative treatment. The consideration of fundamental interactions is a prime example where non-perturbative techniques are needed. Extension of these techniques to finite temperature problems is considered. At present these ideas are primarily used in a perturbative context. However, non-perturbative techniques have been considered in some specific cases. Experts in the field on non-linear dynamics and chaos and fundamental interactions elaborate the techniques and provide a critical look at the present status and explore future directions that may be fruitful. The text of the main talks will be very useful to young graduate students who are starting their studies in these areas.

  19. High definition in-situ electro-optical characterization for Roll to Roll printed electronics

    DEFF Research Database (Denmark)

    Pastorelli, Francesco

    2017-01-01

    Resume: Printed electronics is emerging as a new, large scale and cost effective technology that will be disruptive in fields such as energy harvesting, consumer electronics and medical sensors. The performance of printed organic electronic devices relies principally on the carrier mobility...... and molecular packing of the polymer semiconductor material. Unfortunately, the analysis of such materials is generally performed with destructive techniques, which are hard to make compatible with in situ measurements, and pose a great obstacle for the mass production of printed electronics devices. A rapid......-photon induced photoluminescence (TPPL) and second harmonic response. We anticipate that this non-linear optical method will substantially contribute to the understanding of printed electronic devices and demonstrate it as a promising novel tool for non-destructive and facile testing of materials during printing...

  20. Non-linear estimation is easy

    OpenAIRE

    Fliess, Michel; Join, Cédric; Sira-Ramirez, Hebertt

    2008-01-01

    International audience; Non-linear state estimation and some related topics, like parametric estimation, fault diagnosis, and perturbation attenuation, are tackled here via a new methodology in numerical differentiation. The corresponding basic system theoretic definitions and properties are presented within the framework of differential algebra, which permits to handle system variables and their derivatives of any order. Several academic examples and their computer simulations, with on-line ...

  1. Non-linear Loudspeaker Unit Modelling

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Agerkvist, Finn T.

    2008-01-01

    Simulations of a 6½-inch loudspeaker unit are performed and compared with a displacement measurement. The non-linear loudspeaker model is based on the major nonlinear functions and expanded with time-varying suspension behaviour and flux modulation. The results are presented with FFT plots of three...... frequencies and different displacement levels. The model errors are discussed and analysed including a test with loudspeaker unit where the diaphragm is removed....

  2. Non-linear estimation is easy

    CERN Document Server

    Fliess, Michel; Sira-Ramirez, Hebertt

    2007-01-01

    Non-linear state estimation and some related topics, like parametric estimation, fault diagnosis, and perturbation attenuation, are tackled here via a new methodology in numerical differentiation. The corresponding basic system theoretic definitions and properties are presented within the framework of differential algebra, which permits to handle system variables and their derivatives of any order. Several academic examples and their computer simulations, with on-line estimations, are illustrating our viewpoint.

  3. Improving electro-optic window reliability with DIACER coatings

    Science.gov (United States)

    Carasso, M. L.; Adair, J. H.; Demkowicz, P. A.; Gilbert, D. G.; Singh, Rajiv K.

    1997-06-01

    Most commercial diamond synthesis processes involve some form of chemical vapor deposition (CVD) which results in heterogeneous nucleation on the surface of window or dome materials. Generally, these processes have relatively long deposition times driven by the slow CVD kinetics. An alternate method called DIACERTM uses an aqueous seed crystal dispersion applied to the window substrates prior to CVD. These seed crystals reduce nucleation times and speed CVD deposition rates. Thicker coatings can be produced by repeating the seeding/CVD cycle until the required thickness is achieved. This paper reviews DIACERTM coating results on silicon substrates. Scanning electron microscopy and atomic force microscopy images of images of the coatings are presented. IR transmission results are presented both before and after sand and rain erosion exposures. The results of this testing will show DICERTM coatings to durable for the protection of silicon substrates after exposure to severe sand environments.

  4. Non-linear Behavior of Curved Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian; Jolma, P.; Karjalainen, J. P.;

    2003-01-01

    In this paper the non-linear behavior of curved sandwich panels is investigated both numerically and experimentally. Focus is on various aspects of finite element modeling and calculation procedures. A simply supported, singly curved, CFRP/PVC sandwich panel is analyzed under uniform pressure load...... and results are compared to test data. A novel test arrangement utilizing a water filled cushion to create the uniform pressure load on curved panel specimen is used to obtain the experimental data. The panel is modeled with three different commercial finite element codes. Two implicit and one explicit code...... are used with various element types, modeling approaches and material models. The results show that the theoretical and experimental methods generally show fair agreement in panel non-linear behavior before collapse. It is also shown that special attention to detail has to be taken, because the predicted...

  5. Time-resolved absolute measurements by electro-optic effect of giant electromagnetic pulses due to laser-plasma interaction in nanosecond regime

    Science.gov (United States)

    Consoli, F.; de Angelis, R.; Duvillaret, L.; Andreoli, P. L.; Cipriani, M.; Cristofari, G.; di Giorgio, G.; Ingenito, F.; Verona, C.

    2016-06-01

    We describe the first electro-optical absolute measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054 nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261 kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation.

  6. 40 Gb/s Microstrip Line Polymer Electro-Optic Modulators%40Gb/s微带线电极聚合物电光调制器

    Institute of Scientific and Technical Information of China (English)

    白一鸣; 曲欣; 王晓林; 王士杰; 吴伯瑜

    2011-01-01

    40 Gb/s polymer electro-optic modulators with microstrip line traveling-wave electrode are designed, fabricated and tested. Assuming that the electro-optic coefficient γ33 of the core polymer is 30 pm/V, the performance parameters of the designed modulator are half-wave voltage Vx = 4. 94 V and modulation bandwidth 42 GHz. The modulator is fabricated using the second-order nonlinear optical polymer material BPAN-NT with a completely independent intellectual property as the core layer material of the polymer electro-optic modulator. After that, the performances of the modulators in direct current (DC), low frequencies and microwave regions are tested. The low-frequency (237 Hz) Vx values at 1. 31 and 1. 55 μm wavelengths are 32. 1 and 40. 5 V, respectively. The electro-optic coefficient of core layer material γ33 is thus obtained as 3.856 pm/V. The extinction ratio is measured to be 20 dB. Within the frequencies ranging from 50 MHz to 40 GHz, the actual measured microwave attenuation coefficient ao of the electrode system is 0. 6 dB·cm-1 ·GHz-1/2, Using this value, the modulation bandwidth of the modulator is calculated to be 42.70 GHz. The modulation indices are measured by using optical spectrum analyzer in the frequency range from 7.5 to 16 GHz and from 32 to 40 GHz. And the frequency response curve of the modulation index M of the electro-optic polymer modulator is also obtained. The 3 dB bandwidth of the 40 Gb/s modulator is 30 GHz.%设计、制作和测试了用于1.31和1.55 μm光波长的40 Gb/s微带线行波电极的电光调制器.假设聚合物材料的电光系数γ33=30 pm/V,设计的调制器性能参数分别是半波电压Vπ=4.92 V和调制带宽42 GHz.用有完全自主知识产权的二阶非线性光学聚合物材料BPAN-NT作为芯层材料制作了聚合物电光调制器.对调制器的各项特性参数进行了直流、低频和微波的测试,在1.31和1.55 μm波长上测得低频(237 Hz)Vπ分别为32.1和40.5 V,折算得

  7. Electro-optical switching at 1550 nm using a two-state GeSe phase-change layer.

    Science.gov (United States)

    Soref, Richard; Hendrickson, Joshua; Liang, Haibo; Majumdar, Arka; Mu, Jianwei; Li, Xun; Huang, Wei-Ping

    2015-01-26

    New designs for electro-optical free-space and waveguided 2 x 2 switches are presented and analyzed at the 1.55 μm telecoms wavelength. The proposed devices employ a ~10 nm film of GeSe that is electrically actuated to transition the layer forth-and-back from the amorphous to the crystal phase, yielding a switch with two self-sustaining states. This phase change material was selected for its very low absorption loss at the operation wavelength, along with its electro-refraction Δn ~0.6. All switches are cascadeable into N x M devices. The free-space prism-shaped structures use III-V prism material to match the GeSe crystal index. The Si/GeSe/Si "active waveguides" are quite suitable for directional-coupler switches as well as Mach-Zehnder devices-all of which have an active length 16x less than that in the free-carrier art.

  8. Actively stabilized wavelength-insensitive carrier elimination from an electro-optically modulated laser beam

    CERN Document Server

    Cooper, Nathan; Dunning, Alexander; Freegarde, Tim

    2012-01-01

    We demonstrate a simple and robust technique for removal of the carrier wave from a phase-modulated laser beam, using a non-interferometric method that is insensitive to the modulation frequency and instead exploits the polarization-dependence of electro-optic modulation. An actively stabilized system using feedback via a liquid crystal cell yields long-term carrier suppression in excess of 28 dB at the expense of a 6.5 dB reduction in sideband power.

  9. New Remote Gas Sensor Using Rapid Electro-Optical Path Switching

    Science.gov (United States)

    Sachse, G. W.; Lebel, P. J.; Wallio, H. A.; Vay, S. A.; Wang, L. G.

    1994-01-01

    Innovative gas filter correlation radiometer (GFCR) features nonmechanical switching of internal optical paths. Incoming radiation switched electro-optically, by means of polarization, between two optical paths, one of which contains correlation gas cell while other does not. Advantages include switching speed, 2 to 3 orders of magnitude faster than mechanical techniques, and high reliability. Applications include regional studies of atmospheric chemistry from either manned or unmanned aircraft as well as satellite studies of global distributions, sources and sink mechanisms for key species involved in chemistry of troposphere. Commercial applications: ability to survey many miles of natural gas pipelines rapidly from aircraft, pinpointing gas leaks by measuring methane at 2.3 micrometers.

  10. A polymer electro-optic modulator with ultra wide-band and low driving voltage

    Institute of Scientific and Technical Information of China (English)

    Kambiz Abedi; Habib Vahidi

    2011-01-01

    In this paper,a polymer electro optic modulator is designed and simulated using the full vectorial finite element method.First order edge elements are used in finite element implementation,and the finite element technique is used to obtain modulator response thoroughly.From the numerical analysis,frequency dispersions of modulator's important parameters,such as microwave effective index nm,microwave characteristic impedance Zt and microwave loss α,are extracted.Our design exhibits electrical bandwidth of 260 GHz and drive voltage of about 2.8 V·cm in this frequency.

  11. Thermally Stable Guest-Host Polyetherketone Poled Polymer for Electro-Optical Applications

    Institute of Scientific and Technical Information of China (English)

    潘奇伟; 房昌水; 秦志辉; 顾庆天; 吴祥雯; 史伟; 余金中

    2002-01-01

    The high glass transition temperature polymer polyetherketone doped with disperse red 13 (DR13/PEK-c) has been prepared by the spin-coating method. Through in situ second-harmonic generation, the corona poling temperature was optimized by measuring the temperature dependence of the in situ second-harmonic generation signal intensity under the poling electric field. The linear electro-optic coefficients of the poled polymer films have been determined at 632.8nm by using a simple interferometric technique. The polymer system was measured after 13000h, and found that it remained at 80% of its initial value.

  12. The precision analysis of continuous zoom lens in airborne electro-optical pod

    Science.gov (United States)

    Yang, Xiao-xu; Li, Da-wei; Han, Jun-feng; Dong, Qiang; Huang, Wei; Wei, Yu

    2014-02-01

    In the research of electro-optical pod, this paper propose a mission requirements that continuous zoom lens system is using for measuring angle in the process. This paper analyzes the influence of angle measurement accuracy from focal length and optical axis errors in the process of continuous zoom, and given the mathematical model of the influence of angle measurement accuracy. The simulation analysis indicated that Angle measuring accuracy is affected by the process of continuous zoom. The simulation analysis results have certain instructive significance to engineering practice.

  13. 40 GHz electro-optic modulation in hybrid silicon-organic slotted photonic crystal waveguides.

    Science.gov (United States)

    Wülbern, Jan Hendrik; Prorok, Stefan; Hampe, Jan; Petrov, Alexander; Eich, Manfred; Luo, Jingdong; Jen, Alex K-Y; Jenett, Martin; Jacob, Arne

    2010-08-15

    In this Letter we demonstrate broadband electro-optic modulation with frequencies of up to 40 GHz in slotted photonic crystal waveguides based on silicon-on-insulator substrates covered and infiltrated with a nonlinear optical polymer. Two-dimensional photonic crystal waveguides in silicon enable integrated optical devices with an extremely small geometric footprint on the scale of micrometers. The slotted waveguide design optimizes the overlap of the optical and electric fields in the second-order nonlinear optical medium and, hence, the interaction of the optical and electric waves.

  14. Field-effect active plasmonics for ultracompact electro-optic switching

    OpenAIRE

    Müstecaplıoğlu, Özgür E.; Çetin, Arif E.; Yanık, Ahmet A.; Mertiri, Alket; Erramilli, Shyamsunder; Altuğ, Hatice

    2012-01-01

    Field-effect active plasmonics for ultracompact electro-optic switching Arif E. Çetin, Ahmet A. Yanik, Alket Mertiri, Shyamsunder Erramilli, Özgür E. Müstecaplolu, and Hatice Altug Citation: Applied Physics Letters 101, 121113 (2012); doi: 10.1063/1.4754139 View online: http://dx.doi.org/10.1063/1.4754139 View Table of Contents: http://scitation.aip.org/content/aip/journal/apl/101/12?ver=pdfcov Published by the AIP Publishing Articles you may be interested in A proposal f...

  15. Mid-infrared dual-comb spectroscopy with electro-optic modulators

    CERN Document Server

    Yan, Ming; Iwakuni, Kana; Millot, Guy; Hänsch, Theodor W; Picqué, Nathalie

    2016-01-01

    We demonstrate dual-comb spectroscopy based on difference frequency generation of frequency-agile near-infrared frequency combs, produced with the help of electro-optic modulators. The combs have a remarkably flat intensity distribution and their positions and line spacings can be selected freely by simply dialing a knob. We record, in the 3-micron region, Doppler-limited absorption spectra with resolved comb lines within milliseconds. Precise molecular line parameters are retrieved. Our technique holds promise for fast and sensitive time-resolved studies e.g. of trace gases.

  16. Characteristics of Electro-Optic Device Using Conducting Polymers, Polythiophene and Polypyrrole Films

    Science.gov (United States)

    Kaneto, Keiichi; Yoshino, Katsumi; Inuishi, Yoshio

    1983-07-01

    Detailed characteristics of electro-optic elements (color switching and memory) utilizing the spectral change of conducting polymers by electrochemical doping and undoping are studied. The response time of color switching, for example, red≤ftrightarrowblue in polythiophene film in the electrolyte of LiBF4/acetonitrile is 30˜100 msec under the applied voltages of -2.0{≤ftrightarrow}+4.0 V vs. Li plate. More than 103 cycles of color switch are observed quite reproducibly. Three color states of yellow green, dark brown and blue are demonstrated for polypyrrole film.

  17. Graphene photonics for resonator-enhanced electro-optic devices and all-optical interactions

    Science.gov (United States)

    Englund, Dirk R.; Gan, Xuetao

    2017-03-21

    Techniques for coupling light into graphene using a planar photonic crystal having a resonant cavity characterized by a mode volume and a quality factor and at least one graphene layer positioned in proximity to the planar photonic crystal to at least partially overlap with an evanescent field of the resonant cavity. At least one mode of the resonant cavity can couple into the graphene layer via evanescent coupling. The optical properties of the graphene layer can be controlled, and characteristics of the graphene-cavity system can be detected. Coupling light into graphene can include electro-optic modulation of light, photodetection, saturable absorption, bistability, and autocorrelation.

  18. Graphene photonics for resonator-enhanced electro-optic devices and all-optical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Englund, Dirk R.; Gan, Xuetao

    2017-03-21

    Techniques for coupling light into graphene using a planar photonic crystal having a resonant cavity characterized by a mode volume and a quality factor and at least one graphene layer positioned in proximity to the planar photonic crystal to at least partially overlap with an evanescent field of the resonant cavity. At least one mode of the resonant cavity can couple into the graphene layer via evanescent coupling. The optical properties of the graphene layer can be controlled, and characteristics of the graphene-cavity system can be detected. Coupling light into graphene can include electro-optic modulation of light, photodetection, saturable absorption, bistability, and autocorrelation.

  19. Development of laser marking system with electro-optic Q-switch

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung; Kim, Jeong Moog; Kim, Kwang Suk; Park, Seung Kyu; Baik, Sung Hoon

    1995-11-01

    We developed a high repetition electro-optic Q switch Nd:YAG laser and scan system for laser marking. We localized the scan mirrors and their mounts. We made the database for the optical properties of commercial flat-field lenses with our optics design software. We fabricated the detailed network between the galvanometer based beam scanning system and the laser generator. To accelerate the commercialization by the joint company, the training and transfer of technology were pursued in the joint participation by company researchers from the early stage. (author). 8 refs., 6 tabs., 27 figs.

  20. Silicon-on-Insulator Based Electro-optic Variable Optical Attenuator with a Series Structure

    Institute of Scientific and Technical Information of China (English)

    HE Yue-Jiao; LI Fang; LIU Yu-Liang

    2005-01-01

    An electro-optic variable optical attenuator in silicon-on-insulator is designed and fabricated. A series structure is used to improve the device efficiency. Compared to the attenuator in the single p-i-n diode structure in the same modulating length, the attenuation range of the device in the series structure improves 2-3 times in the same injecting current density, while the insertion loss is not affected. The maximum dynamic attenuation of the device is greater than 30dB. The response frequency is obtained to be about 2MHz.

  1. ElectroOptical measurements of ultrashort 45 MeV electron beam bunch

    CERN Document Server

    Nikas, D; Kowalski, L A; Larsen, R; Lazarus, D M; Ozben, C; Semertzidis, Y K; Tsang, Thomas; Srinivasan-Rao, T

    2001-01-01

    We have made an observation of 45 MeV electron beam bunches using the nondestructive electro-optical (EO) technique. The amplitude of the EO modulation was found to increase linearly with electron beam charge and decrease inversely with the optical beam path distance from the electron beam. The risetime of the signal was bandwidth limited by our detection system to \\~70ps. An EO signal due to ionization caused by the electrons traversing the EO crystal was also observed. The EO technique may be ideal for the measurement of bunch structure with femtosecond resolution of relativistic charged particle beam bunches.

  2. Invariant electro-optical system for deflection measurement of floating docks

    Science.gov (United States)

    Gorbachev, Alexey A.; Hoang, Anh Phuong

    2017-06-01

    An electro-optical system for deflection measurement of floating docks is represented in this paper. This system contains a base unit with two measurement channels observing opposite directions of the dock. It also includes a set of reference marks and an industrial computer. The measurement unit contains of a camera with long focal-length lens and a beam splitter. The effect of the beam splitter turning point on the image position of the reference mark on the camera is analyzed as well in this paper.

  3. Non Linear Behaviour in Learning Processes

    OpenAIRE

    Manfredi, Paolo; Manfredi, Vicenzo Rosario

    2003-01-01

    This article is mainly based on R. E. Kahn's contribution to the book Non Linear Dynamics in Human Behavior. As stressed by Bronowski, both in art and in science, a person becomes creative by finding "a new unity" that is a link between things which were not thought alike before. Indeed the creative mind is a mind that looks for unexpected likeness finding a more profound unity, a pattern behind chaotic phenomena. In the context of scientific discovery, it can also be argued that creativi...

  4. BRST structure of non-linear superalgebras

    CERN Document Server

    Asorey, M; Radchenko, O V; Sugamoto, A

    2008-01-01

    In this paper we analyse the structure of the BRST structure of nonlinear superalgebras. We consider quadratic non-linear superalgebras where a commutator (in terms of (super) Poisson brackets) of the generators is a quadratic polynomial of the generators. We find the explicit form of the BRST charge up to cubic order in Faddeev-Popov ghost fields for arbitrary quadratic nonlinear superalgebras. We point out the existence of constraints on structure constants of the superalgebra when the nilpotent BRST charge is quadratic in Faddeev-Popov ghost fields. The general results are illustrated by simple examples of superalgebras.

  5. Limits on Non-Linear Electrodynamics

    CERN Document Server

    Fouché, M; Rizzo, C

    2016-01-01

    In this paper we set a framework in which experiments whose goal is to test QED predictions can be used in a more general way to test non-linear electrodynamics (NLED) which contains low-energy QED as a special case. We review some of these experiments and we establish limits on the different free parameters by generalizing QED predictions in the framework of NLED. We finally discuss the implications of these limits on bound systems and isolated charged particles for which QED has been widely and successfully tested.

  6. Low-loss, silicon integrated, aluminum nitride photonic circuits and their use for electro-optic signal processing.

    Science.gov (United States)

    Xiong, Chi; Pernice, Wolfram H P; Tang, Hong X

    2012-07-11

    Photonic miniaturization requires seamless integration of linear and nonlinear optical components to achieve passive and active functions simultaneously. Among the available material systems, silicon photonics holds immense promise for optical signal processing and on-chip optical networks. However, silicon is limited to wavelengths above 1.1 μm and does not provide the desired lowest order optical nonlinearity for active signal processing. Here we report the integration of aluminum nitride (AlN) films on silicon substrates to bring active functionalities to chip-scale photonics. Using CMOS-compatible sputtered thin films we fabricate AlN-on-insulator waveguides that exhibit low propagation loss (0.6 dB/cm). Exploiting AlN's inherent Pockels effect we demonstrate electro-optic modulation up to 4.5 Gb/s with very low energy consumption (down to 10 fJ/bit). The ultrawide transparency window of AlN devices also enables high speed modulation at visible wavelengths. Our low cost, wideband, carrier-free photonic circuits hold promise for ultralow power and high-speed signal processing at the microprocessor chip level.

  7. Effect of MWCNTs on the electro-optic properties of 5CB LC cells during the Freedericksz Transition

    Science.gov (United States)

    Eakle, Matthew; Georgiev, Georgi; Atherton, Timothy; Cebe, Peggy

    2014-03-01

    Multi-walled carbon nanotubes (MWCNTs) affect the electro-optic properties of liquid crystals, but the mechanisms of interaction between the two remain not well understood. To address this, we are investigating the effect of alternating electric fields on the optical properties and Freedericksz Transition of 5CB liquid crystal with different concentrations of MWCNTs. 5CB cells with ITO electrodes were made using spin-coated PVA for sample alignment and MylarTM spacer films to control the thickness, which ranged from 12 to 23 microns. Transmission optical ellipsometry was used to measure the optical retardance (phase delay) and uniaxial director angle of 5CB liquid crystals as the peak voltage of a high-frequency (1 kHz - 1 MHz) AC electric field was varied from 0 to 10 V. For constant frequency, the Freedericksz Transition was noted by a sharp decrease in retardance from an initial plateau, which gradually decreased toward zero as the voltage increased. With increasing frequency, the decay broadened and the Freedericksz Transition occurred at higher voltage. Numerical simulations of CNT-facilitated switching are also presented. Research was funded by the National Science Foundation, Polymers Program of the Division of Materials Research, through DMR-12061010.

  8. Low-loss, silicon integrated, aluminum nitride photonic circuits and their use for electro-optic signal processing

    CERN Document Server

    Xiong, Chi; Tang, Hong X

    2014-01-01

    Photonic miniaturization requires seamless integration of linear and nonlinear optical components to achieve passive and active functions simultaneously. Among the available material systems, silicon photonics holds immense promise for optical signal processing and on-chip optical networks. However, silicon is limited to wavelengths above 1100 nm and does not provide the desired lowest order optical nonlinearity for active signal processing. Here we report the integration of aluminum nitride (AlN) films on silicon substrates to bring active functionalities to chip-scale photonics. Using CMOS-compatible sputtered thin films we fabricate AlN-on-insulator waveguides that exhibit low propagation loss (0.6 dB/cm). Exploiting AlN's inherent Pockels effect we demonstrate electro-optic modulation up to 4.5 Gb/s with very low energy consumption (down to 10 fJ/bit). The ultra-wide transparency window of AlN devices also enables high speed modulation at visible wavelengths. Our low cost, wideband, carrier-free photonic ...

  9. Dielectric and electro-optic studies of a bimesogenic liquid crystal composed of bent-core and calamitic units.

    Science.gov (United States)

    Balachandran, R; Panov, V P; Vij, J K; Shanker, G; Tschierske, C; Merkel, K; Kocot, A

    2014-09-01

    A bimesogen, BR1, composed of a bent-core and calamitic unit, linked laterally via a flexible spacer is investigated by dielectric and electro-optic techniques. X-ray results show the presence of clusters in the nematic phase, and the cluster size is of the order of the thickness of a single layer. The splitting of the small-angle scattering Δχ/2 is about 50°, which indicates SmC like clusters with a significant tilt of the molecules in the quasilayers. The sign reversal of the dielectric anisotropy Δε' is observed as a function of frequency; the behavior is rather similar to that exhibited by the conventional dual frequency nematics, composed of a calamitic mesogen, with the exception that it occurs at much lower frequencies in this material. Interestingly, as the bimesogen enters its nematic phase, the average permittivity decreases as the temperature is lowered. This indicates the onset of antiparallel association of some of the dipoles in the system, and this type of association is much more prominent in BR1 in comparison to other bent-core liquid crystalline systems composed of the same bisbenzoate core unit. The analysis of the dielectric spectra using the Maier-Meier model confirms the onset of an antiparallel correlation of dipoles occurring at the isotropic to nematic phase transition temperature. Additionally these results support a model of the cluster where the transverse dipole moments in the neighboring layers are antiparalleled to each other.

  10. A COMPUTER PROGRAMME FOR THE NON-LINEAR ANALYSIS OF COMPLETE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Turgay ÇOŞGUN

    2003-02-01

    Full Text Available The progress made on the analysis of the structures by using non-linear theory and the significant findings on both theorical and empirical works, enable better understanding of the behaviours of structures under external loads. Determination of the failure load and designing the structures accordingly requires developments of analysis methods, which take both the non-linear behaviour of structural elements and the non-linear effects of geometric changes into consideration. Therefore, in this study, a FORTRAN code, which analyses structures and calculates the failure loads by considering the non-linear behaviour of materials under increasing loads (due to the non-linear relationship of stress-strain and moment-curvature and second-order theory of structural systems is developed.

  11. Measurement of Frequency Shift Characteristics Based on LiNbO3 Waveguide Electro-Optic Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    Zhou Meng; Hui-Juan Zhou; Yi Liao; Qiong Yao

    2008-01-01

    High-speed and wide-band LiNbO3 waveguide electro-optic intensity modulator has drawn great attention in the field of optical fiber communi-cation and sensor. This paper reports the research results on the measurement of frequency shift character-istics of Mach-Zehnder electro-optic intensity modulator. Two measurement methods of frequency shift character-istics for high and low frequency modulations are studied in theory and experiment and demonstrate different results. The realization of a multi-wavelength optical source based on Mach-Zehnder electro-optic intensity modulator has been introduced. The technique to reach the maximum intensity for interesting shift frequency, particularly for heterodyne detection of Brillouin distributed optical fiber sensing, has been given.

  12. H-infinity mix sensitivity controller design based on GIMC for electro-optical stabilization and tracking system

    Science.gov (United States)

    Liu, Zi-dong; Bao, Qi-liang; Xia, Yunxia; Liu, Xiang

    2013-08-01

    Electro-optical stabilization and tracking system is critical and difficult issue in satellite laser communication. Moreover, line-of-sight stabilized system is the kernel of implementing electro-optical stabilization and tracking system, which can be used to isolate the vibration of the moving platform of the satellite and the disturbance of the space environment. In this paper, we propose a new method, which using H∞ mix sensitivity based on generalized internal model controller (GIMC), to design the control system of the electro-optical stabilized platform. It is well known that there is an intrinsic conflict between performance and robustness in the standard feedback framework. Generalized internal model controller is a new architecture which can separate the performance and robustness design in controller design. This architecture has two parts: a high performance controller, say K0,which is designed by PI controller in this paper, and then a robustification controller, say Q, which is designed to improve the ability of the anti disturbance by using H-infinity mix sensitivity controller design method. In this paper, we also present the steps of controller design by using this method to make it easier to use. Based on the proposed method, numerical simulation and experiment are both carried out for a gyro stabilized platform of electro-optical tacking system. Both the numerical simulated and the experimental results show that the electro-optical stabilized platform using the H-infinity mix sensitivity controller design method based on GIMC is accurate and effective. Comparing with the same PI controller in standard feedback framework, the proposed method can guarantee the high tracking performance as same as the PI controller and improve the external disturbance restraining ability a lot. In conclusion, H-infinity mix sensitivity controller design method based on GIMC is a new approach for gyro stabilized platform of electro-optical stabilization and tracking

  13. Improved performance of traveling wave directional coupler modulator based on electro-optic polymer

    CERN Document Server

    Zhang, Xingyu; Lin, Che-yun; Wang, Alan X; Hosseini, Amir; Lin, Xiaohui; Chen, Ray T

    2014-01-01

    Polymer based electro-optic modulators have shown great potentials in high frequency analog optical links. Existing commercial LiNibO3 Mach-Zehnder modulators have intrinsic drawbacks in linearity to provide high fidelity communication. In this paper, we present the design, fabrication and characterization of a traveling wave directional coupler modulator based on electro-optic polymer, which is able to provide high linearity, high speed, and low optical insertion loss. A silver ground electrode is used to reduce waveguide sidewall roughness due to the scattering of UV light in photolithography process in addition to suppressing the RF loss. A 1-to-2 multi-mode interference 3dB-splitter, a photobleached refractive index taper and a quasi-vertical taper are used to reduce the optical insertion loss of the device. The symmetric waveguide structure of the MMI-fed directional coupler is intrinsically bias-free, and the modulation is obtained at the 3-dB point regardless of the ambient temperature. By achieving lo...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-31

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

  15. Development of in-orbit refocusing mechanism for SpaceEye-1 electro-optical payload

    Science.gov (United States)

    Lee, Minwoo; Kim, Jongun; Chang, Jin-Soo; Kang, Myung-Seok

    2016-09-01

    SpaceEye-1 earth observation satellite, developed by Satrec Initiative Co. Ltd., is a 300 kg scale spacecraft with high resolution electro-optical payload (EOS-D) which performs 1 m GSD, 12 km swath in low earth orbit. Metering structure of EOS-D is manufactured with Carbon Fiber Reinforced Plastic (CFRP). Due to the moisture emission from CFRP metering structure, this spaceborne electro-optical payload undergoes shrinkage after orbit insertion. The shrinkage of metering structure causes change of the distance between primary and secondary mirror. In order to compensate the moisture shrinkage effect, two types of thermal refocusing mechanism were developed, analyzed and applied to EOS-D. Thermal analysis simulating in-orbit thermal condition and thermo-elastic displacement analysis was conducted to calculate the performance of refocusing mechanism. For each EOS-D telescope, analytical refocusing range (displacement change between primary and secondary mirror) was 2.5 um and 3.6 um. Thus, the refocusing mechanism can compensate the dimensional instability of metering structure caused by moisture emission. Furthermore, modal, static and wavefront error analysis was conducted in order to evaluate natural frequency, structural stability and optical performance. As a result, it can be concluded that the refocusing system of EOS-D payload can perform its function in orbit.

  16. High sensitivity photonic time-stretch electro-optic sampling of terahertz pulses

    CERN Document Server

    Szwaj, Christophe; Parquier, Marc Le; Roy, Pascale; Manceron, Laurent; Brubach, Jean-Blaise; Tordeux, Marie-Agnès; Bielawski, Serge

    2016-01-01

    Single-shot recording of terahertz electric signals has recently become possible at high repetition rates, by using the photonic time-stretch electro-optic sampling (EOS) technique. However the moderate sensitivity of time-stretch EOS is still a strong limit for a range of applications. Here we present a variant enabling to increase the sensitivity of photonic time-stretch for free-propagating THz signals. A key point is to integrate the idea presented in Ref. [Ahmed et al., Rev. Sci. Instrum. 85, 013114 (2014)], for upgrading classical time-stretch systems. The method is tested using the high repetition rate terahertz coherent synchrotron radiation source (CSR) of the SOLEIL synchrotron radiation facility. The signal-to-noise ratio of our terahertz digitizer could thus be straightforwardly improved by a factor $\\approx 6.5$, leading to a noise-equivalent input electric field below $1.25$~V/cm inside the electro-optic crystal, over the 0-300~GHz band (i.e, 2.3~$\\mu$V/cm/$\\sqrt{\\text{Hz}}$). The sensitivity is...

  17. Impact of lateral carrier confinement on electro-optical tuning properties of polariton condensates

    Energy Technology Data Exchange (ETDEWEB)

    Brodbeck, S.; Suchomel, H.; Amthor, M.; Wolf, A.; Kamp, M. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Schneider, C. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Mediterranean Institute of Fundamental Physics, Via Appia Nuova 31, 00040 Rome (Italy); Höfling, S. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY 16 9SS (United Kingdom)

    2015-07-27

    Electro-optical measurements on exciton-polaritons below and above the condensation threshold are performed on high quality, pin-doped microcavities with embedded GaAs quantum wells. Applying an external electric field shifts the polariton emission by hundreds of μeV both in the linear and the nonlinear regime. We study three device geometries to investigate the influence of carrier confinement in the plane of the quantum well on the electro-optical tuning properties. In the conventional micropillar geometry, the electric field tuning behavior is dominated by the effects of carrier tunneling and electric field screening that manifest in a blueshift of the polariton emission. In stark contrast, for a planar sample geometry, we can significantly extend the range of electric fields and a redshift is observed. To separate the contributions of quantum confined Stark effect and reduced exciton oscillator strength to the energy shift, we study a third sample where the etching of micropillars is stopped just above the active region. In this semi-planar geometry, exciton and polariton emissions can be measured simultaneously. As for the planar geometry, redshifts of the polariton emission are observed below and above threshold that are well reproduced by theoretical shifts.

  18. EVALUATION METHOD FOR PARASITIC EFFECTS OF THE ELECTRO-OPTICAL MODULATOR IN A FIBER OPTIC GYROSCOPE

    Directory of Open Access Journals (Sweden)

    S. A. Volkovskiy

    2016-09-01

    Full Text Available Subject of Research.The paper proposes an original method for studying the parasitic effects in the electro-optic modulator of the fiber optic gyroscope. Proposed method is based on the usage of a special waveform phase modulation signal. Method. The essence of the proposed method lies in modification of serrodyne modulation signal, thereby providing a periodic displacement of the phase difference signal to the maximum of the interference curve. In this case, the intensity level reflects the influence of parasitic effects with the degree of manifestation being determined by the sequence of voltage control signals applied to the modulator. Enumeration of combinations of control signals and the corresponding intensity levels gives the possibility to observe an empirical dependence of the parasitic effects and use it later for compensation. Main Results. The efficiency of the proposed method is demonstrated by the program model of the fiber optic gyroscope. The results of the method application on a production sample of the device were obtained. Comparison with the results of direct estimate of the parasitic intensity modulation effect testifies to the effectiveness of the proposed method. Practical Relevance. The method can be used as a diagnostic tool to quantify the influence of parasitic effects in the electro-optic modulator of the fiber optic gyroscope as well as for their subsequent compensation.

  19. Analysis of electro-optic switches with series-coupled multiple microring resonators

    Institute of Scientific and Technical Information of China (English)

    YAN Xin; MA Chun-sheng; ZHENG Chuan-tao; WANG Xian-yin; ZHANG Da-ming

    2009-01-01

    In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius ofthe microring is 15.2 μm, the coupling gap between the microring and the channel is 0.14 μm, and the one between the microring and the microring is 0.6 μm, microring number M is 4, the switching voltage is 4 V, the insertion loss is 5.4 dB, and the crosstalk is -20 dB. The output spectrum is much flatter and much steeper than that of the single microring.

  20. Electro-optic properties of indium/erbium-codoped lithium niobate crystal for integrated optics

    Science.gov (United States)

    Du, Wan-Ying; Zhang, Zi-Bo; Ren, Shuai; Wong, Wing-Han; Yu, Dao-Yin; Pun, Edwin Yue-Bun; Zhang, De-Long

    2017-02-01

    Clamped and unclamped electro-optic coefficients γ13 and γ33 of In3+/Er3+-codoped LiNbO3 crystals, which were grown by Czochralski method from the melts containing 0.5 mol% Er2O3 while varied In2O3 contents of 0.0, 0.5, 1.0 and 1.5 mol%, were measured by Mach-Zehnder interferometry. The results show that In3+/Er3+ codoping does not cause change of γ13 and γ33, and both γ13 and γ33 can be regarded as unchanged in the studied In3+ concentration range of 0-2.6 mol% (in crystal) within the experimental error of 3%. The small doping effect is desired in light of the electro-optic application of the crystal. A qualitative, comprehensible explanation for the small effect is given on the basis of the EO coefficient model of LiNbO3 and doping effect on the defect structure of LiNbO3.

  1. Performance of an electro-optical solar compass in partially obscured Sun conditions.

    Science.gov (United States)

    Bollanti, S; De Meis, D; Di Lazzaro, P; Flora, F; Gallerano, G P; Mezi, L; Murra, D; Vicca, D

    2016-04-20

    Solar compasses are designed to accurately find true North on sunny days. However, no data on their performance are available when sunlight is partially blocked, e.g., by a cloud. We have measured, for the first time to the best of our knowledge, the performance of one of the most accurate electro-optical solar compasses (accuracy better than 0.01  deg) as a function of the solar disk obscuration during the Sun's eclipse on 20 March 2015. The measurements show that the accuracy level is mainly dependent on the asymmetry of the obscuration with respect to the main axis of the optical detection system and, to a lesser extent, on the percentage of the solar disk covered. In particular, azimuth measurement suffered a maximum deviation of 0.08 deg when 35% of the solar disk was asymmetrically obscured. The deviation was smaller when 46% of the solar disk was more symmetrically obscured. This experiment demonstrates that, even in the case of a partially obscured Sun, the electro-optical solar compass maintains an accuracy better than magnetic and electronic compasses.

  2. High sensitivity photonic time-stretch electro-optic sampling of terahertz pulses

    Science.gov (United States)

    Szwaj, C.; Evain, C.; Le Parquier, M.; Roy, P.; Manceron, L.; Brubach, J.-B.; Tordeux, M.-A.; Bielawski, S.

    2016-10-01

    Single-shot recording of terahertz electric signals has recently become possible at high repetition rates, by using the photonic time-stretch electro-optic sampling (EOS) technique. However the moderate sensitivity of time-stretch EOS is still a strong limit for a range of applications. Here we present a variant enabling to increase the sensitivity of photonic time-stretch for free-propagating THz signals. The ellipticity of the laser probe is enhanced by adding a set of Brewster plates, as proposed by Ahmed et al. [Rev. Sci. Instrum. 85, 013114 (2014)] in a different context. The method is tested using the high repetition rate terahertz coherent synchrotron radiation source of the SOLEIL synchrotron radiation facility. The signal-to-noise ratio of our terahertz digitizer could thus be straightforwardly improved by a factor ≈6.5, leading to a noise-equivalent input electric field below 1.25 V/cm inside the electro-optic crystal, over the 0-300 GHz band (i.e., 2.3 μ V / cm / √{ Hz } ). The sensitivity is scalable with respect to the available laser power, potentially enabling further sensitivity improvements when needed.

  3. Single-shot electron bunch length measurements using a spatial electro-optical autocorrelation interferometer.

    Science.gov (United States)

    Sütterlin, Daniel; Erni, Daniel; Schlott, Volker; Sigg, Hans; Jäckel, Heinz; Murk, Axel

    2010-10-01

    A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.

  4. Electro-optical equivalent calibration technology for high-energy laser energy meters.

    Science.gov (United States)

    Wei, Ji Feng; Chang, Yan; Sun, Li Qun; Zhang, Kai; Hu, Xiao Yang; Zhang, Wei

    2016-04-01

    Electro-optical equivalent calibration with high calibration power and high equivalence is particularly well-suited to the calibration of high-energy laser energy meters. A large amount of energy is reserved during this process, however, which continues to radiate after power-off. This study measured the radiation efficiency of a halogen tungsten lamp during power-on and after power-off in order to calculate the total energy irradiated by a lamp until the high-energy laser energy meter reaches thermal equilibrium. A calibration system was designed based on the measurement results, and the calibration equivalence of the system was analyzed in detail. Results show that measurement precision is significantly affected by the absorption factor of the absorption chamber and by heat loss in the energy meter. Calibration precision is successfully improved by enhancing the equivalent power and reducing power-on time. The electro-optical equivalent calibration system, measurement uncertainty of which was evaluated as 2.4% (k = 2), was used to calibrate a graphite-cone-absorption-cavity absolute energy meter, yielding a calibration coefficient of 1.009 and measurement uncertainty of 3.5% (k = 2). A water-absorption-type high-energy laser energy meter with measurement uncertainty of 4.8% (k = 2) was considered the reference standard, and compared to the energy meter calibrated in this study, yielded a correction factor of 0.995 (standard deviation of 1.4%).

  5. Electro-optical equivalent calibration technology for high-energy laser energy meters

    Science.gov (United States)

    Wei, Ji Feng; Chang, Yan; Sun, Li Qun; Zhang, Kai; Hu, Xiao Yang; Zhang, Wei

    2016-04-01

    Electro-optical equivalent calibration with high calibration power and high equivalence is particularly well-suited to the calibration of high-energy laser energy meters. A large amount of energy is reserved during this process, however, which continues to radiate after power-off. This study measured the radiation efficiency of a halogen tungsten lamp during power-on and after power-off in order to calculate the total energy irradiated by a lamp until the high-energy laser energy meter reaches thermal equilibrium. A calibration system was designed based on the measurement results, and the calibration equivalence of the system was analyzed in detail. Results show that measurement precision is significantly affected by the absorption factor of the absorption chamber and by heat loss in the energy meter. Calibration precision is successfully improved by enhancing the equivalent power and reducing power-on time. The electro-optical equivalent calibration system, measurement uncertainty of which was evaluated as 2.4% (k = 2), was used to calibrate a graphite-cone-absorption-cavity absolute energy meter, yielding a calibration coefficient of 1.009 and measurement uncertainty of 3.5% (k = 2). A water-absorption-type high-energy laser energy meter with measurement uncertainty of 4.8% (k = 2) was considered the reference standard, and compared to the energy meter calibrated in this study, yielded a correction factor of 0.995 (standard deviation of 1.4%).

  6. Measurement of z-axis deviation angle of electro-optic crystal by conoscopic interference

    Science.gov (United States)

    Li, Dong; Liu, Yong; Liu, Xu; Jiang, Hongzhen; Zheng, Fanglan

    2016-09-01

    Properties of plasma electrode pockels cell is directly affected by the Z-axis deviation angle of the electro-optic crystal. Therefore, high precision measurement of the Z-axis deviation angle is indispensable. By using conoscopic interference technique, a measurement system for Z-axis deviation angle of electro-optic crystal is introduced. The principle of conoscopic interference method is described in detail, and a series of techniques are implied in this measurement system to improve the accuracy. High-precision positioning method of the crystal based on Michelson interference is proposed to determine the normal consistency of crystal, which can ensure the high positioning repeatability of crystal in the measurement process. The positioning comparison experiment of the crystal shows that the standard deviation of our method is less than 1pixel, which is much better than the traditional method (nearly 4pixels). Moreover, melatope extraction algorithm of optical axis based on image matching technique is proposed to ensure the melatope can be extracted in high precision. Calibration method of the normal of transmission surface of crystal is also proposed. The experiment results show that the PV and rms of Z-axis deviation angle is less than 0.05mrad and 0.02mrad, respectively. The repeatability accuracy is less than 0.01mrad.

  7. High sensitivity electro-optic modulation of slow light in ellipse rods PC-CROW

    Science.gov (United States)

    Li, Changhong; Wan, Yong; Zong, Weihua

    2017-07-01

    A tunable slow light with low group velocity, high buffer performance and high sensitivity is realized in photonic crystal coupled resonator optical waveguide (PC-CROW) with elliptical rod around cavity. By adjusting the long axis and short axis of the elliptical rods, the slow light and buffer performance of PC-CROW are optimized. As ae=0.42a, be=0.20a, the group velocity is below 2.3053×10-4c, simultaneously, the buffer capacity C and delay time Ts reach the optimum value of 9.8214 bit and 354.8 ps. Then the dynamic modulation of the slow light and buffer performance based on this optimized structure has been discussed systematically. Thanks to the electro-optic effect of the polystyrene substrate, the guided mode shifts linearly to short wavelength in sensitivity of 3.0 nm/mV around 1550 nm, as the applied voltage increases. The modulation sensitivities of delay time and buffer capacity are 0.445 ns/mV and 0.051 bit/mV, respectively. These results show a considerable potential for this structure that can be dynamically controlled according to the practical requirements by electro-optic effect in PC-CROW.

  8. Electro-optical study of the exposure of Azospirillum brasilense carbohydrate epitopes.

    Science.gov (United States)

    Guliy, Olga I; Matora, Larisa Yu; Dykman, Lev A; Staroverov, Sergey A; Burygin, Gennady L; Bunin, Viktor D; Burov, Andrei M; Ignatov, Oleg V

    2015-01-01

    The exposure of Azospirillum brasilense carbohydrate epitopes was investigated by electro-optical analysis of bacterial cell suspensions. To study changes in the electro-optical (EO) properties of the suspensions, we used antibodies generated to the complete lipopolysaccharide of A. brasilense type strain Sp7 and also antibodies to the smooth and rough O polysaccharides of Sp7. After 18 hr of culture growth, the EO signal of the suspension treated with antibodies to smooth O polysaccharide was approximately 20% lower than that of the suspension treated with antibodies to complete lipopolysaccharide (control). After 72 hr of culture growth, the strongest EO signal was observed for the cells treated with antibodies to rough O polysaccharide (approximately 46% greater than the control), whereas for the cells treated with antibodies to smooth O polysaccharide, it was much lower (approximately 23% of the control). These data were confirmed by electron microscopy. The results of the study may have importance for the rapid evaluation of changes in lipopolysaccharide form in microbial biotechnology, when the antigenic composition of the bacterial surface requires close control.

  9. Electromechanical and electro-optical functions of plasticized PVC with colossal dielectric constant

    Science.gov (United States)

    Sato, Hiromu; Hirai, Toshihiro

    2013-04-01

    A soft dielectric polymer, plasticized poly(vinyl chloride) (PVC gel), has been known as a characteristic actuator with electrotactic creep deformation. The deformation can be applied for bending and contraction. The mechanism of the deformation has been attributed to the colossal dielectric constant of the gel induced by dc field. The dielectric constant at 1 Hz, jumps from less than10 to thousand times larger value. The huge dielectric constant suggests the gel can have electro-optic function. In this paper, we introduce the gel can bend light direction by applying a dc electric field. The PVC gel can bend light direction depending on the electric field. Detailed feature of the light bending will be introduced and discussed. Bending angle can be controlled by dielectric plasticizer and electric field. The components of the gel, PVC and plasticizer themselves, did not show any effect of electro-optical function like the PVC gel. The same feature can be observed in other polymer, like poly(vinyl alcohol)-dimethyl sulphoxide gel, too.

  10. Long-term cavity closure in non-linear rocks

    Science.gov (United States)

    Cornet, Jan; Dabrowski, Marcin; Schmid, Daniel Walter

    2017-08-01

    -field deformation rate. The solution remains valid in the limit of ideal power-law fluid when \\overline M_s = 1/n. The solution is based on an approximation which transforms the non-linear isotropic constitutive law into a linear anisotropic one in the far field. The proposed approximate solution for closure velocity for general far-field load is based on the two end-member analytical solutions. They are additively combined after replacing the material threshold viscosity μ0 by the apparent background viscosity due to the far-field shear. Benchmarking the solution shows that there is a 50 per cent misfit at most between the analytical and the numerical solution for closure rate. Comparing the closure velocities obtained with a Carreau viscosity model with the ones from a power-law material shows an increase of several orders of magnitude for pressure loads smaller than 2{μ _0}D_{II}^*. Far field shear can also increase hole closure rate by several orders of magnitude. Compared with other available solutions, the approximate solution presented here ensures that both speed ups are taken into account making it well suited for actual underground conditions where both diffusion creep and shear stresses occur. The additional closure mechanisms considered here can potentially explain the fast closure rates observed underground without referring to transient mechanisms.

  11. Experimental and theoretical investigation of electro-optic and all-optical implementations of wavelength converting 2R-regenerators

    DEFF Research Database (Denmark)

    Wolfson, David; Mikkelsen, Benny; Danielsen, Søren Lykke

    1998-01-01

    We investigate and compare the regenerative capability of electro-optic wavelength converters based on electrically controlled external Mach-Zehnder (MZ) modulators and all-optical wavelength converters based on all-optically controlled external MZ modulators. The latter incorporates semiconductor...... optical amplifiers (SOAs) as optically controlled phase shifters. Experiments demonstrate a 5-6 dB noise suppression capability for both the electro-optic and the all-optical implementation of the wavelength-converting regenerators. The performance can be further improved by cascading two converters...

  12. Reprint of: Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    Energy Technology Data Exchange (ETDEWEB)

    Pan, R., E-mail: rui.pan@stfc.ac.uk [Accelerator Science and Technology Centre, Science and Technology Facilities Council, Darebsury Laboratory, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); School of Engineering, Physics and Mathematics, University of Dundee, Nethergate, Dundee DD1 4HN (United Kingdom); Jamison, S.P. [Accelerator Science and Technology Centre, Science and Technology Facilities Council, Darebsury Laboratory, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Lefevre, T. [CERN, CH-1211 Geneva 23 (Switzerland); Gillespie, W.A. [School of Engineering, Physics and Mathematics, University of Dundee, Nethergate, Dundee DD1 4HN (United Kingdom)

    2016-09-11

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding (EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  13. Study of Electro-Optical Measuring System for Measuring the Swaying of Rocket Launcher and Artillery Systems

    Institute of Scientific and Technical Information of China (English)

    LI Yang; YAN Yu-feng; CAI Li-juan; LIU Zhen-bo

    2008-01-01

    A scheme is proposed, of that the axis of directional barrel is simulated by a laser beam and an electro-optical axial angle encoder is using to measure the swaying of rocket Muncher or artillery. The measuring principle is stated, and an electro-optical measuring system is designed, including automatic force-applying device, angle-measurement device and photodetecting screen. The measurement accuracy of the system is analyzed. The measuring error of system is less then 17.3"(0.08 mil).

  14. Reprint of: Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    Science.gov (United States)

    Pan, R.; Jamison, S. P.; Lefevre, T.; Gillespie, W. A.

    2016-09-01

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding (EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  15. Non-linear feedback neural networks VLSI implementations and applications

    CERN Document Server

    Ansari, Mohd Samar

    2014-01-01

    This book aims to present a viable alternative to the Hopfield Neural Network (HNN) model for analog computation. It is well known that the standard HNN suffers from problems of convergence to local minima, and requirement of a large number of neurons and synaptic weights. Therefore, improved solutions are needed. The non-linear synapse neural network (NoSyNN) is one such possibility and is discussed in detail in this book. This book also discusses the applications in computationally intensive tasks like graph coloring, ranking, and linear as well as quadratic programming. The material in the book is useful to students, researchers and academician working in the area of analog computation.

  16. Non-linear optical titanyl arsenates: Crystal growth and properties

    Science.gov (United States)

    Nordborg, Jenni Eva Louise

    Crystals are appreciated not only for their appearance, but also for their unique physical properties which are utilized by the photonic industry in appliances that we come across every day. An important part of enabling the technical use of optical devices is the manufacture of crystals. This dissertation deals with a specific group of materials called the potassium titanyl phosphate (KIP) family, known for their non-linear optical and ferroelectric properties. The isomorphs vary in their linear optical and dielectric properties, which can be tuned to optimize device performance by forming solid solutions of the different materials. Titanyl arsenates have a wide range of near-infrared transmission which makes them useful for tunable infrared lasers. The isomorphs examined in the present work were primarily RbTiOASO4 (RTA) and CsTiOAsO4 (CTA) together with the mixtures RbxCs 1-xTiOAsO4 (RCTA). Large-scale crystals were grown by top seeding solution growth utilizing a three-zone furnace with excellent temperature control. Sufficiently slow cooling and constant upward lifting produced crystals with large volumes useable for technical applications. Optical quality RTA crystals up to 10 x 12 x 20 mm were grown. The greater difficulty in obtaining good crystals of CTA led to the use of mixed RCTA materials. The mixing of rubidium and cesium in RCTA is more favorable to crystal growth than the single components in pure RTA and CTA. Mixed crystals are rubidium-enriched and contain only 20-30% of the cesium concentration in the flux. The cesium atoms show a preference for the larger cation site. The network structure is very little affected by the cation substitution; consequently, the non-linear optical properties of the Rb-rich isomorphic mixtures of RTA and CTA can be expected to remain intact. Crystallographic methods utilizing conventional X-ray tubes, synchrotron radiation and neutron diffraction have been employed to investigate the properties of the atomic

  17. Optimal non-linear health insurance.

    Science.gov (United States)

    Blomqvist, A

    1997-06-01

    Most theoretical and empirical work on efficient health insurance has been based on models with linear insurance schedules (a constant co-insurance parameter). In this paper, dynamic optimization techniques are used to analyse the properties of optimal non-linear insurance schedules in a model similar to one originally considered by Spence and Zeckhauser (American Economic Review, 1971, 61, 380-387) and reminiscent of those that have been used in the literature on optimal income taxation. The results of a preliminary numerical example suggest that the welfare losses from the implicit subsidy to employer-financed health insurance under US tax law may be a good deal smaller than previously estimated using linear models.

  18. Chaotic Discrimination and Non-Linear Dynamics

    Directory of Open Access Journals (Sweden)

    Partha Gangopadhyay

    2005-01-01

    Full Text Available This study examines a particular form of price discrimination, known as chaotic discrimination, which has the following features: sellers quote a common price but, in reality, they engage in secret and apparently unsystematic price discounts. It is widely held that such forms of price discrimination are seriously inconsistent with profit maximization by sellers.. However, there is no theoretical salience to support this kind of price discrimination. By straining the logic of non-linear dynamics this study explains why such secret discounts are chaotic in the sense that sellers fail to adopt profit-maximising price discounts. A model is developed to argue that such forms of discrimination may derive from the regions of instability of a dynamic model of price discounts.

  19. Symmetries in Non-Linear Mechanics

    CERN Document Server

    Aldaya, Victor; López-Ruiz, Francisco F; Cossío, Francisco

    2014-01-01

    In this paper we exploit the use of symmetries of a physical system so as to characterize the corresponding solution manifold by means of Noether invariants. This constitutes a necessary preliminary step towards the correct quantisation in non-linear cases, where the success of Canonical Quantisation is not guaranteed in general. To achieve this task "point symmetries" of the Lagrangian are generally not enough, and the notion of contact transformations is in order. The use of the Poincar\\'e-Cartan form permits finding both the symplectic structure on the solution manifold, through the Hamilton-Jacobi transformation, and the required symmetries, realized as Hamiltonian vector fields, associated with functions on the solution manifold (thus constituting an inverse of the Noether Theorem), lifted back to the evolution space through the inverse of this Hamilton-Jacobi mapping. In this framework, solutions and symmetries are somehow identified and this correspondence is also kept at a perturbative level. We prese...

  20. Risks of non-linear climate change

    Energy Technology Data Exchange (ETDEWEB)

    Van Ham, J.; Van Beers, R.J.; Builtjes, P.J.H.; Koennen, G.P.; Oerlemans, J.; Roemer, M.G.M. [TNO-SCMO, Delft (Netherlands)

    1995-12-31

    Climate forcing as a result of increased concentrations of greenhouse gases has been primarily addressed as a problem of a possibly warmer climate. So far, such change has been obscured in observations, possibly as a result of natural climate variability and masking by aerosols. Consequently, projections of the effect of climate forcing have to be based on modelling, more specifically by applying Global Circulation Models GCMs. These GCMs do not cover all possible feedbacks; neither do they address all specific possible effects of climate forcing. The investigation reviews possible non-linear climate change which does not fall within the coverage of present GCMs. The review includes the potential relevance of changes in biogeochemical cycles, aerosol and cloud feedback, albedo instability, ice-flow instability, changes in the thermohaline circulation and changes resulting from stratospheric cooling. It is noted that these changes may have different time horizons. Three from the investigated issues provide indications for a possible non-linear change. On the decadal scale stratospheric cooling, which is the result of the enhanced greenhouse effect, in combination with a depleted ozone layer, could provide a positive feedback to further ozone depletion, in particular in the Arctic. Decreasing albedo on the Greenland ice sheet may enhance the runoff from this ice sheet significantly in case of warming on a timescale of a few centuries. Changes in ocean circulation in the North Atlantic could seasonally more than compensate a global warming of 3C in North-West Europe on a timescale of centuries to a millennium. 263 refs.

  1. The non-linear evolution of edge localized modes

    Energy Technology Data Exchange (ETDEWEB)

    Wenninger, Ronald

    2013-01-09

    Edge localized modes (ELMs) are instabilities in the edge of tokamak plasmas in the high confinement regime (H-mode). Without them the edge transport in ordinary H-mode plasmas is too low to establish a stationary situation. However in a future device large unmitigated ELMs are believed to cause divertor power flux densities far in excess of tolerable material limits. Hence the size of energy loss per ELM and the resulting ELM frequency must be controlled. To proceed in understanding how the ELM size is determined and how ELM mitigation methods work it is necessary to characterize the non-linear evolution of pedestal erosion. In order to achieve this experimental data is compared to the results of ELM simulations with the code JOREK (reduced MHD, non-linear) applying a specially developed synthetic magnetic diagnostic. The experimental data are acquired by several fast sampling diagnostics at the experiments ASDEX Upgrade and TCV at a large number of toroidal/poloidal positions. A central element of the presented work is the detailed characterization of dominant magnetic perturbations during ELMs. These footprints of the instability can be observed most intensely in close temporal vicinity to the onset of pedestal erosion. Dominant magnetic perturbations are caused by current perturbations located at or inside the last closed flux surface. In ASDEX Upgrade under certain conditions dominant magnetic perturbations like other H-mode edge instabilities display a similarity to solitons. Furthermore - as expected - they are often observed to be correlated to a perturbation of electron temperature. In TCV it is possible to characterize the evolution of the toroidal structure of dominant magnetic perturbations. Between growing above the level of background fluctuations and the maximum perturbation level for all time instance a similar toroidal structure is observed. This rigid mode-structure is an indication for non-linear coupling. Most frequently the dominant toroidal

  2. Non-linear excitation of quantum emitters in two-dimensional hexagonal boron nitride

    CERN Document Server

    Schell, Andreas W; Takashima, Hideaki; Takeuchi, Shigeki; Aharonovich, Igor

    2016-01-01

    Two-photon absorption is an important non-linear process employed for high resolution bio-imaging and non-linear optics. In this work we realize two-photon excitation of a quantum emitter embedded in a two-dimensional material. We examine defects in hexagonal boron nitride and show that the emitters exhibit similar spectral and quantum properties under one-photon and two-photon excitation. Furthermore, our findings are important to deploy two-dimensional hexagonal boron nitride for quantum non-linear photonic applications.

  3. SOME PROBLEMS CONCERNING FREE NON-LINEAR VIBRATIONS OF BEAM STRUCTURES

    Directory of Open Access Journals (Sweden)

    S. V. Bosakov

    2008-01-01

    Full Text Available The paper analyzes an influence of physical non-linearity material account on vibrations of single beams with various support fixing. The authors also analyze power criteria for existing stable periodic vibrations and dependence of vibration period on initial power is determined in the paper. Accurate values of an amplitude and non-linear bending vibration period of beams have been also determined as a conservative system with due account of initial conditions. A number of examples are given that clearly illustrate the obtained solutions and show an influence rate of the mentioned effects on amplitude-frequency characteristics of non-linear systems. 

  4. Experimental and numeric studies of one electro-optical flexible pipe (umbilical); Estudos numericos e experimentais de um umbilical eletro-optico

    Energy Technology Data Exchange (ETDEWEB)

    Lepore, Paula Ferreira; Buelta Martinez, Miguel Angel [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    2005-07-01

    This work had as objective to develop, to implant, to survey and to test an experimental and numerical model of structural, applicable analysis of umbilical structures. An ample study of the behavior of its constituent layers was carried through, in special of its nucleus and material constituents, when operating under different conditions of tensions and deformations. As support for this work, experimental tests for one type of electro-optic umbilical with typical transversal section had been carried through. This was made with the intention to optimize the developed numerical model. With this model of structural analysis, the project of umbilicals could highly improved, in terms of the total weight of the handle, which is one of the great problems for its use in great depths, with the maximum of efficiency and the minimum of losses, foreseeing and hindering operation imperfections that can come to occur due to extreme deformation or electric rupture of the layers, hoses or handles. (author)

  5. Electro-optic Effects in Special Asymmetric Quantum Wells%一种特殊的非对称量子阱中的电光效应

    Institute of Scientific and Technical Information of China (English)

    俞友宾; 郭康贤; 于凤梅

    2004-01-01

    Recently, there has been an increasing interest in nonlinear optical properties of semiconductor quantum well structures, because of their relevance for studying practical applications and as a probe for the electronic structure of mesoscopic media. In this paper, the nonlinear electro-optic effects in special asymmetric quantum wells are studied. Because of this kind of quantum well is more approximate a practical quantum well between the conduction band and valence band, and it can be realized very easily in experiment. The analytical expressions of electro-optic coefficient have been derived by compact density-matrix approach and the numerical results were presented for GaAs/AlGaAs asymmetric quantum wells. The shape of the quantum well varying with the parameter a and the parameter V0 were plotted. Itis found that the asyrmnetry of the quantum wells enhances with the increase of parameter a. On the contrary, the asymmetry of the quantum walls decreases with the increase of the parameter Vo. The maximum values of the electro-optic coefficient varying with the parameter a and the parameter V0 were plotted. The numerical results show the electro-optic coefficient enhances with the increases of the parameter a and the decrease of the parameter V0. Therefore, it is found that the electro-optic coefficient increases with the enhancement of the quantum wells' asymmetry. The electro-optic coefficient as afunction of the photon energy with different values of parameter a and different values of parameter V0 were also plotted. It can be observed that there are three peak values in the figures, respectively. And it is obvious that the larger the asymmetry of quantum wells is, the bigger the peak value is. It can be seen that with the increase of the asymmetry of quantum well, the peaks move to the low energy side.Moreover, the electro-optic coefficient obtained in this special quantum well is as large as 104 m/V.With the advances of nanofabrication technology recently, it

  6. Non-Linear Dynamics of Saturn’s Rings

    Science.gov (United States)

    Esposito, Larry W.

    2015-11-01

    Non-linear processes can explain why Saturn’s rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. We find that stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, pushing the system across thresholds that lead to persistent states.Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity, and allows aggregates to grow. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit.Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like ‘straw’ that can explain the halo structure and spectroscopy: This requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping at perturbed regions in Saturn’s rings creates both high velocity dispersion and large aggregates at these distances, explaining both small and large particles observed there. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating the Markov chain as an asymmetric random walk with reflecting boundaries allows us to determine the power law index from results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects

  7. Polycarbonate-Based Blends for Optical Non-linear Applications

    Science.gov (United States)

    Stanculescu, F.; Stanculescu, A.

    2016-02-01

    This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

  8. Polycarbonate-Based Blends for Optical Non-linear Applications.

    Science.gov (United States)

    Stanculescu, F; Stanculescu, A

    2016-12-01

    This paper presents some investigations on the optical and morphological properties of the polymer (matrix):monomer (inclusion) composite materials obtained from blends of bisphenol A polycarbonate and amidic monomers. For the preparation of the composite films, we have selected monomers characterised by a maleamic acid structure and synthesised them starting from maleic anhydride and aniline derivatives with -COOH, -NO2, -N(C2H5)2 functional groups attached to the benzene ring. The composite films have been deposited by spin coating using a mixture of two solutions, one containing the matrix and the other the inclusion, both components of the composite system being dissolved in the same solvent. The optical transmission and photoluminescence properties of the composite films have been investigated in correlation with the morphology of the films. The scanning electron microscopy and atomic force microscopy have revealed a non-uniform morphology characterised by the development of two distinct phases. We have also investigated the generation of some optical non-linear (ONL) phenomena in these composite systems. The composite films containing as inclusions monomers characterised by the presence of one -COOH or two -NO2 substituent groups to the aromatic nucleus have shown the most intense second-harmonic generation (SHG). The second-order optical non-linear coefficients have been evaluated for these films, and the effect of the laser power on the ONL behaviour of these materials has also been emphasised.

  9. 无人机光电载荷及其应用%UAV Electro-optical Payloads and Application

    Institute of Scientific and Technical Information of China (English)

    王正林

    2013-01-01

      简要介绍了无人机优势及应用范围,对目前世界上主要固定翼无人机及无人直升机的光电载荷进行了研究分析,在此基础上,对新型无人飞行器概念平台进行介绍。最后总结了无人机光电载荷发展趋势,即随着无人机平台技术及光电载荷技术的迅速发展,长航时、良好隐身性、多用途、具备主动光电干扰能力、高智能将是无人机光电载荷的发展趋势。%The advantages and applications of unmanned aerial vehicle (UAV) are briefly introduced. The electro-optical payloads on fixed wing UAV and UAV helicopter are analyzed. Based on this, the new UAV plat⁃form is introduced. The development trends of UAV electro-optical payloads are summarized in the end. With the rapid development of UAV platform technology and electro-optical payload technology, UAV electro-opti⁃cal payloads will have the characteristics of long endurance, good stealthy, multipurpose, active electro-optical jamming ability and high intelligence.

  10. Optimized Optical Rectification and Electro-optic Sampling in ZnTe Crystals with Chirped Femtosecond Laser Pulses

    DEFF Research Database (Denmark)

    Erschens, Dines Nøddegaard; Turchinovich, Dmitry; Jepsen, Peter Uhd

    2011-01-01

    We report on optimization of the intensity of THz signals generated and detected by optical rectification and electro-optic sampling in dispersive, nonlinear media. Addition of a negative prechirp to the femtosecond laser pulses used in the THz generation and detection processes in 1-mm thick ZnT...

  11. Electro-optical properties of a polymer light-emitting diode with an injection-limited hole contact

    NARCIS (Netherlands)

    van Woudenbergh, T; Blom, PWM; Huiberts, JN

    2003-01-01

    The electro-optical characteristics of a polymer light-emitting diode with a strongly reduced hole injection have been investigated. A silver contact on poly-dialkoxy-p-phenylene vinylene decreases the hole injection by five orders of magnitude, resulting in both a highly reduced light output and cu

  12. On the design and construction of drifting-mine test targets for sonar, radar and electro-optical detection experiments

    NARCIS (Netherlands)

    Dol, H.S.

    2014-01-01

    The timely detection of small hazardous objects at the sea surface, such as drifting mines, is challenging for ship-mounted sensor systems, both for underwater sensor systems like sonar and above-water sensor systems like radar and electro-optics (lidar, infrared/visual cameras). This is due to the

  13. Electro-optical effects in porous PET films filled with liquid crystal: new possibilities for fiber optics and THZ applications.

    Science.gov (United States)

    Chopik, A; Pasechnik, S; Semerenko, D; Shmeliova, D; Dubtsov, A; Srivastava, A K; Chigrinov, V

    2014-03-15

    The results of investigation of electro-optical properties of porous polyethylene terephthalate films filled with a nematic liquid crystal (5 CB) are presented. It is established that the optical response of the samples on the applied voltage drastically depends on the frequency range. At low frequencies of applied electrical field (foptical response arises as an impulse of light intensity, which decays for the time essentially shorter than the electric pulse duration. At high frequencies (f>fc) electric field induces an overall change in the light intensity, which is typical for an electro-optical response of a liquid crystal (LC) layer in a conventional "sandwich"-like cell. The dependences of critical frequency fc, threshold voltages, and characteristic times on a pore diameter d were established. The peculiarities of electro-optical effects can be explained in the framework of the approach which connects the variations of light intensity with the corresponding changes of the effective refractive index n(eff) of a composite LC media. The unusual behavior of the electro-optical response at low frequencies is assigned to the orienting action of the specific shear flow typical for electrokinetic phenomena in polar liquids.

  14. Modeling Non-Linear Material Properties in Composite Materials

    Science.gov (United States)

    2016-06-28

    will be used to calculate the thermal strains. In equation [6], α is the coefficient of thermal expansion tensor . To determine the effects of the...governing equation for the microscale, where I is the identity tensor and Hk(y) is a Y-periodic tensor on the micro- scale relating T1 to the macro...9c] is the governing equation for the global scale. In this equation, � represents the effective thermal conductivity tensor , � is the

  15. Characterization of the electro-optical transceivers in the KM3NeT optical network

    Directory of Open Access Journals (Sweden)

    Pulvirenti S.

    2016-01-01

    Full Text Available KM3NeT is a future research infrastructure hosting a network of neutrino telescopes in the abyss of the Mediterranean Sea. The whole data transport over an optical network is based on the Dense Wavelength Division Multiplexing technique with optical channels spaced 50 GHz apart and a bit rate of 1.25 Gbps. Over the telescope lifetime, precise temperature control of the laser is required to maintain stability of the central frequency, complying with the recommendations of the International Telecommunication Union. We will report on the characterisation of the tuneable features of the electro-optical transceivers required to compensate for the expected wavelength drift due to aging factors. Preliminary results will be showed.

  16. Aluminum nitride electro-optic phase shifter for backend integration on silicon.

    Science.gov (United States)

    Zhu, Shiyang; Lo, Guo-Qiang

    2016-06-13

    An AlN electro-optic phase shifter with a parallel plate capacitor structure is fabricated on Si using the back-end complementary metal-oxide-semiconductor technology, which is feasible for multilayer photonics integration. The modulation efficiency (Vπ⋅Lπ product) measured from the fabricated waveguide-ring resonators and Mach-Zehnder Interferometer (MZI) modulators near the 1550-nm wavelength is ∼240 V⋅cm for the transverse electric (TE) mode and ∼320 V⋅cm for the transverse magnetic (TM) mode, from which the Pockels coefficient of the deposited AlN is deduced to be ∼1.0 pm/V for both TE and TM modes. The methods for further modulation efficiency improvement are addressed.

  17. Retardance and flicker modeling and characterization of electro-optic linear retarders by averaged Stokes polarimetry.

    Science.gov (United States)

    Martínez, Francisco J; Márquez, Andrés; Gallego, Sergi; Francés, Jorge; Pascual, Inmaculada; Beléndez, Augusto

    2014-02-15

    A polarimetric method for the measurement of linear retardance in the presence of phase fluctuations is presented. This can be applied to electro-optic devices behaving as variable linear retarders. The method is based on an extended Mueller matrix model for the linear retarder containing the time-averaged effects of the instabilities. As a result, an averaged Stokes polarimetry technique is proposed to characterize both the retardance and its flicker magnitude. Predictive capability of the approach is experimentally demonstrated, validating the model and the calibration technique. The approach is applied to liquid crystal on silicon displays (LCoS) using a commercial Stokes polarimeter. Both the magnitude of the average retardance and the amplitude of its fluctuation are obtained for each gray level value addressed, thus enabling a complete phase characterization of the LCoS.

  18. A compact plasmonic MOS-based 2×2 electro-optic switch

    Science.gov (United States)

    Ye, Chenran; Liu, Ke; Soref, Richard A.; Sorger, Volker J.

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, indium-tin-oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with silicon-on-insulator platforms for low-cost manufacturing.

  19. High-speed switching of biphoton delays through electro-optic pump frequency modulation

    Directory of Open Access Journals (Sweden)

    Ogaga D. Odele

    2017-01-01

    Full Text Available The realization of high-speed tunable delay control has received significant attention in the scene of classical photonics. In quantum optics, however, such rapid delay control systems for entangled photons have remained undeveloped. Here for the first time, we demonstrate rapid (2.5 MHz modulation of signal-idler arrival times through electro-optic pump frequency modulation. Our technique applies the quantum phenomenon of nonlocal dispersion cancellation along with pump frequency tuning to control the relative delay between photon pairs. Chirped fiber Bragg gratings are employed to provide large amounts of dispersion which result in biphoton delays exceeding 30 ns. This rapid delay modulation scheme could be useful for on-demand single-photon distribution in addition to quantum versions of pulse position modulation.

  20. A 130 GHz Electro-Optic Ring Modulator with Double-Layer Graphene

    Directory of Open Access Journals (Sweden)

    Lei Wu

    2017-02-01

    Full Text Available The optical absorption coefficient of graphene will change after injecting carriers. Based on this principle, a high-speed double-layer graphene electro-optic modulator with a ring resonator structure was designed in this paper. From the numerical simulations, we designed a modulator. Its optical bandwidth is larger than 130 GHz, the switching energy is 0.358 fJ per bit, and the driven voltage is less than 1.2 V. At the same time, the footprint of the proposed modulator is less than 10 microns squared, which makes the process compatible with the Complementary Metal Oxide Semiconductors (CMOS process. This will provide the possibility for the on-chip integration of the photoelectric device.

  1. A Single Shot, Sub-picosecond Beam Bunch Characterization with Electro-optic Techniques

    CERN Document Server

    Semertzidis, Y K; Castillo, V; Larsen, R; Lazarus, D M; Nikas, D; Ozben, C; Srinivasan-Rao, T; Stillman, A; Tsang, Thomas; Kowalski, L A

    2001-01-01

    In the past decade, the bunch lengths of electrons in accelerators have decreased dramatically to the range of a few picoseconds \\cite{Uesaka94,Trotz97}. Measurement of the length as well as the longitudinal profile of these short bunches have been a topic of research in a number of institutions \\cite{Uesaka97,Liu97,Hutchins00}. One of the techniques uses the electric field induced by the passage of electrons in the vicinity of a birefringent crystal to change its optical characteristics. Well-established electro-optic techniques can then be used to measure the temporal characteristics of the electron bunch. In this paper we present a novel, non-invasive, single-shot approach to improve the resolution to tens of femtoseconds so that sub-millimeter bunch length can be measured.

  2. Reconfigurable electro-optical directed-logic circuit using carrier-depletion micro-ring resonators.

    Science.gov (United States)

    Qiu, Ciyuan; Gao, Weilu; Soref, Richard; Robinson, Jacob T; Xu, Qianfan

    2014-12-15

    Here we demonstrate a reconfigurable electro-optical directed-logic circuit based on a regular array of integrated optical switches. Each 1×1 optical switch consists of a micro-ring resonator with an embedded lateral p-n junction and a micro-heater. We achieve high-speed on-off switching by applying electrical logic signals to the p-n junction. We can configure the operation mode of each switch by thermal tuning the resonance wavelength. The result is an integrated optical circuit that can be reconfigured to perform any combinational logic operation. As a proof-of-principle, we fabricated a multi-spectral directed-logic circuit based on a fourfold array of switches and showed that this circuit can be reconfigured to perform arbitrary two-input logic functions with speeds up to 3  GB/s.

  3. Study on electro-optic properties of two-dimensional PLZT photonic crystal band structure

    Institute of Scientific and Technical Information of China (English)

    TONG Kai; WU Xiao-gang; WANG Mei-ting

    2011-01-01

    The band characteristics of two-dimensional (2D) lead lanthanum zirconate titanate (PLZT) photonic cystals are analyzed by finite element method. The electro-optic effect of PLZT can cause the refractive index change when it is imposed by the applied electric field, and the band structure of 2D photonic crystals based on PLZT varies accordingly. The effect of the applied electric field on the structural characteristics of the first and second band gaps in 2D PLZT photonic crystals is analyzed in detail. And the results show that for each band gap, the variations of start wavelength, cut-off wavelength and bandwidth are proportional to quadratic of the electric field.

  4. Correlations of electro-optical and nanostructural properties of CdTe thin films

    Science.gov (United States)

    Levi, D. H.; Moutinho, H. R.; Hasoon, F. S.; Ahrenkiel, R. K.; Kazmerski, L. L.; Al-Jassim, M. M.

    1996-01-01

    This paper presents correlations of macroscopic optical properties with the nanoscale physical and electronic structure of CdTe/CdS thin films used for photovoltaic cell fabrication. We have studied the evolution of these properties under systematic variation of post-growth treatment conditions for several standard deposition techniques. The electro-optical properties and nanostructure depend strongly on deposition conditions and post-growth treatments. Our results indicate that the standard CdCl2—heat treatment enhances grain size and passivates defects. We have also found strong evidence for sulfur diffusion across the CdTe—CdS interface. This interdiffusion produces a thin layer at the junction with a bandgap lower than the rest of the absorber layer. This effect could have important implications for photoexcited carrier collection in photovoltaic applications.

  5. Correlations of electro-optical and nanostructural properties of CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Levi, D.H.; Moutinho, H.R.; Hasoon, F.S.; Ahrenkiel, R.K.; Kazmerski, L.L.; Al-Jassim, M.M. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401 (United States)

    1996-01-01

    This paper presents correlations of macroscopic optical properties with the nanoscale physical and electronic structure of CdTe/CdS thin films used for photovoltaic cell fabrication. We have studied the evolution of these properties under systematic variation of post-growth treatment conditions for several standard deposition techniques. The electro-optical properties and nanostructure depend strongly on deposition conditions and post-growth treatments. Our results indicate that the standard CdCl{sub 2}{emdash}heat treatment enhances grain size and passivates defects. We have also found strong evidence for sulfur diffusion across the CdTe{emdash}CdS interface. This interdiffusion produces a thin layer at the junction with a bandgap lower than the rest of the absorber layer. This effect could have important implications for photoexcited carrier collection in photovoltaic applications. {copyright} {ital 1996 American Institute of Physics.}

  6. Evaluations on aero-optic effects of subsonic airborne electro-optical system

    Institute of Scientific and Technical Information of China (English)

    Kexin Yin; Huilin Jiang

    2006-01-01

    @@ A simple method based on CFD code and Matlab for aero-optic effects is presented. Density fluctuation from CFD code due to the changes of such factors as altitude, speed, equipment location, and wavelength is introduced as an input to Matlab. The overall calculations are in Matlab. The results show that the performance of electro-optical (EO) system can be improved when the altitude increasing, the speed is as slowly as possible, and the equipment location moves to the leading edge of the airborne platform as far as possible, for the wavelength there is an optimum one when the indexes of contrast and resolution of the system are both considered. All of these methods can minimize the optical aberrations. Several numerical simulations demonstrate the method.

  7. Electro-optic and dynamic studies of biphenyl benzoate ferroelectric liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hemine, J., E-mail: hemine1@yahoo.f [Laboratoire de Physique de la Matiere Condensee, Universite Hassan II, Mohammedia-Casablanca, BP 146, F.S.T. Mohammedia (Morocco); Daoudi, A. [Universite Lille Nord de France, F-59000 Lille (France); ULCO, LDSMM, F-59140 Dunkerque (France); CNRS UMR8024, F-59140 Dunkerque (France); Legrand, C. [Universite Lille Nord de France, F-59000 Lille (France); ULCO, LEMCEL, F-62228 Calais (France); El kaaouachi, A.; Nafidi, A. [Laboratoire de Physique de la Matiere Condensee, Faculte des Sciences Ibnou Zohr, BP 28/S 80000 Agadir (Morocco); Ismaili, M.; Isaert, N. [Universite Lille Nord de France, F-59000 Lille (France); USTL, LDSMM, F-59655 Villeneuve d' Ascq (France); CNRS UMR8024, F-59655 Villeneuve d' Ascq (France); Nguyen, H.T. [Centre de Recherche Paul Pascal, Universite de Bordeaux 1, 33600 Pessac (France)

    2010-05-01

    We present electro-optic and dynamic properties on three homologous of biphenyl benzoate series of ferroelectric liquid crystals (FLCs) exhibiting the chiral smectic C phase (SmC*). The three compounds present high spontaneous polarization and show the SmC*-SmA*-N* phase sequence. Dielectric spectroscopy was used to provide the dynamics and dipolar ordering of the ferroelectric phase. The Goldstone relaxation mode was studied for sample cells on planar geometry without a DC bias voltage. The rotational viscosity corresponding to molecular motions in the SmC* phase was determined from dielectric measurements. The Arrhenius-type behavior of the rotational viscosity was found and the corresponding activation energies were evaluated.

  8. Stabilisation of a fibre frequency synthesiser using acousto-optical and electro-optical modulators

    Science.gov (United States)

    Koliada, N. A.; Nyushkov, B. N.; Pivtsov, V. S.; Dychkov, A. S.; Farnosov, S. A.; Denisov, V. I.; Bagayev, S. N.

    2016-12-01

    A fibre-optic frequency synthesiser is developed that is stabilised to the optical frequency standard based on molecular iodine ({\\text{Nd : YAG/I}}2). The possibility of transferring stability of the optical frequency standard to other optical frequencies in the IR range 1 - 2 \\unicode{956}{\\text{m}} and to the RF range by using synthesiser phase-locked loops (PLLs) with acousto-optical and electro-optical modulators is experimentally demonstrated. The additive instability introduced into the optical frequency comb of the synthesiser (which arises due to PLL residual random errors) is several orders less than the intrinsic instability of the reference optical frequency standard employed (i.e., is noticeably less than 1 × 10-13 for 1 {\\text{s}} and 5 × 10-15 for 1000 {\\text{s}}).

  9. A compact plasmonic MOS-based 2x2 electro-optic switch

    CERN Document Server

    Ye, Chenran; Soref, Richard A; Sorger, Volker J

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, Indium-Tin-Oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 dB (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with Siliconon- Insulator platforms to for low-cost manufacturing.

  10. Design of a multi-point microwave interferometer using the electro-optic effect

    Science.gov (United States)

    Specht, Paul E.; Cooper, Marcia A.; Jilek, Brook A.

    2017-01-01

    A multi-point microwave interferometer (MPMI) concept is presented for non-invasively monitoring the internal transit of a shock, detonation, or reaction front in energetic media. The concept utilizes an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser with a microwave signal. Polarization optics convert this phase lag into an amplitude modulation. A heterodyne interferometer compares the modulated laser beam to a constant reference. This enables the detection of changes in the modulating microwave frequency generated by the motion of the measurement surface. The design is scalable and makes use of the established construction and analysis methods employed in photonic Doppler velocimetry (PDV). The technical challenges associated with the concept are the frequency stability of the lasers, the amount of light return after EO modulation, and the frequency uncertainty of fast Fourier transform (FFT) methods.

  11. An investigation on a novel PDLC film’s fabrication and its electro-optical properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A polymer dispersed liquid crystal (PDLC) film that has good electro-optical properties is produced by the method of polymerized-induced phase separation. Based on the application foreground, its capability parameters, such as contrast ratio, work voltage, and visual angle, are characterized for the first time by a white light but not a fixed wavelength light. The results show the PDLC film has a low work-voltage of 20 V, more than 150° visual angle, high stability, and long lifetime. The differences between plastic and glass ITO-coated substrates of PDLC films are also studied in this paper. The plastic substrate has better property and will have a wider perspective especially in the portable, tender and folded display devices. Due to adjustable properties of film by electric field, PDLC has the potential application for display device, sensor, switch, grating, and new generation analytical apparatus.

  12. An innovative procedure for calibration of strapdown electro-optical sensors onboard unmanned air vehicles.

    Science.gov (United States)

    Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio; Rispoli, Attilio

    2010-01-01

    This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms).

  13. Spectral Shearing of Quantum Light Pulses by Electro-Optic Phase Modulation.

    Science.gov (United States)

    Wright, Laura J; Karpiński, Michał; Söller, Christoph; Smith, Brian J

    2017-01-13

    Frequency conversion of nonclassical light enables robust encoding of quantum information based upon spectral multiplexing that is particularly well-suited to integrated-optics platforms. Here we present an intrinsically deterministic linear-optics approach to spectral shearing of quantum light pulses and show it preserves the wave-packet coherence and quantum nature of light. The technique is based upon an electro-optic Doppler shift to implement frequency shear of heralded single-photon wave packets by ±200  GHz, which can be scaled to an arbitrary shift. These results demonstrate a reconfigurable method to controlling the spectral-temporal mode structure of quantum light that could achieve unitary operation.

  14. Electro-optic modulation methods in range-gated active imaging.

    Science.gov (United States)

    Chen, Zhen; Liu, Bo; Liu, Enhai; Peng, Zhangxian

    2016-01-20

    A time-resolved imaging method based on electro-optic modulation is proposed in this paper. To implement range resolution, two kinds of polarization-modulated methods are designed, and high spatial and range resolution can be achieved by the active imaging system. In the system, with polarization beam splitting the incident light is split into two parts, one of which is modulated with cos(2) function and the other is modulated with sin(2) function. Afterward, a depth map can be obtained from two simultaneously received images by dual electron multiplying charge-coupled devices. Furthermore, an intensity image can also be obtained from the two images. Comparisons of the two polarization-modulated methods indicate that range accuracy will be promoted when the polarized light is modulated before beam splitting.

  15. Lidar Electro-Optic Beam Switch with a Liquid Crystal Variable Retarder

    Science.gov (United States)

    Baer, James

    2012-01-01

    A document discusses a liquid crystal variable retarder, an electro-optic element that changes the polarization of an optical beam in response to a low-voltage electronic signal. This device can be fabricated so that the element creates, among other states, a half-wave of retardance that can be reduced to a very small retardance. When aligned to a polarized source, this can act to rotate the polarization by 90 in one state, but generate no rotation in the other state. If the beam is then incident on a polarization beam splitter, it will efficiently switch from one path to the other when the voltage is applied. The laser beam switching system has no moving parts, improving reliability over mechanical switching. It is low cost, tolerant of high laser power density, and needs only simple drive electronics, minimizing the required system resources.

  16. Strictly non-blocking 4×4 silicon electro-optic switch matrix

    Science.gov (United States)

    Zhou, Pei-Ji; Xing, Jie-Jiang; Li, Xian-Yao; Li, Zhi-Yong; Yu, Jin-Zhong; Yu, Yu-De

    2015-12-01

    The first path-independent insertion-loss (PILOSS) strictly non-blocking 4×4 silicon electro-optic switch matrix is reported. The footprint of this switch matrix is only 4.6 mm×1.0 mm. Using single-arm modulation, the crosstalk measured in this test is -13 dB˜ -27 dB. And a maximum crosstalk deterioration of 6dB caused by two-path interference is also found. Project supported by the National Basic Research Program of China (Grant No. 2011CB301701), the National High Technology Research and Development Program of China (Grant Nos. 2013AA014402, 2012AA012202, and 2015AA016904), and the National Natural Science Foundation of China (Grant Nos. 61275065 and 61107048).

  17. Defect enhanced optic and electro-optic properties of lead zirconate titanate thin films

    Directory of Open Access Journals (Sweden)

    M. M. Zhu

    2011-12-01

    Full Text Available Pb(Zr1-xTixO3 (PZT thin films near phase morphotropic phase boundary were deposited on (Pb0.86La0.14TiO3-coated glass by radio frequency sputtering. A retrieved analysis shows that the lattice parameters of the as-grown PZT thin films were similar to that of monoclinic PZT structure. Moreover, the PZT thin films possessed refractive index as high as 2.504 in TE model and 2.431 in TM model. The as-grown PZT thin film had one strong absorption peak at 632.6 nm, which attributed to lead deficiency by quantitative XPS analysis. From the attractive properties achieved, electro-optic and photovoltaic characteristic of the films were carried out.

  18. Photolithography by a tunable electro-optical lithium niobate phase array

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Photolithography experiments are performed by means of an optical phase mask with electrooptically tunable phase step.The phase mask consists of a 2-dimensional hexagonal lattice of inverted ferroelectric domains fabricated on a z-cut lithium niobate substrate. The electro-optically tunable phase step, between inverted domain, is obtained by the application of an external electric field along the z axis of the crystal via transparent electrodes. The collimated beam of an argon laser passes through the phase mask and the near field intensity patterns, at different planes of the Talbot length and for different values of the applied voltage, are used for photolithographic experiments. Preliminary results are shown and further applications are discussed.

  19. Self-referencing a continuous-wave laser with electro-optic modulation

    CERN Document Server

    Beha, Katja; Del'Haye, Pascal; Coillet, Aurélien; Diddams, Scott A; Papp, Scott B

    2015-01-01

    We phase-coherently measure the frequency of continuous-wave (CW) laser light by use of optical-phase modulation and f-2f nonlinear interferometry. Periodic electro-optic modulation (EOM) transforms the CW laser into a continuous train of picosecond optical pulses. Subsequent nonlinear-fiber broadening of this EOM frequency comb produces a supercontinuum with 160 THz of bandwidth. A critical intermediate step is optical filtering of the EOM comb to reduce electronic-noise-induced decoherence of the supercontinuum. Applying f-2f self-referencing with the supercontinuum yields the carrier-envelope offset frequency of the EOM comb, which is precisely the difference of the CW laser frequency and an exact integer multiple of the EOM pulse repetition rate. Here we demonstrate absolute optical frequency metrology and synthesis applications of the self-referenced CW laser with <5E-14 fractional accuracy and stability.

  20. Design of slotted high quality factor photonic-crystal nanocavities embedded in electro-optic polymers

    Science.gov (United States)

    Nakadai, Masahiro; Konoike, Ryotaro; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

    2017-09-01

    We improve design quality factors of slotted photonic crystal nanocavities embedded in electro-optic polymers (EOPs), which enables control of resonant wavelengths without the use of light-absorbing free carriers. We form nanocavities by modifying single- and double-slotted line-defect waveguides with lattice-constant modulations analytically determined based on dispersions of the waveguides. A double-slotted nanocavity achieves a fourfold increase in Q factor (36 million) compared to a single-slotted nanocavity with similar modulation of lattice constants. Both structures can realize large concentration of light in the EOP region (50%), and resonant wavelength modulations of ∼0.01% are expected with applied voltage of 2 V.

  1. Loop-locked coherent population trapping magnetometer based on a fiber electro-optic modulator.

    Science.gov (United States)

    Hu, Yong; Feng, Y Y; Xu, Chi; Xue, H B; Sun, Li

    2014-04-01

    We have set up a coherent population trapping (CPT)-based magnetometer prototype with the D1 line of ⁸⁷Rb atoms. The dichromatic light field is derived from a fiber electro-optic modulator (FEOM) connected to an external cavity laser diode. A CPT resonance signal with a 516 Hz linewidth is observed. By feeding back the derivative of the resonance curve to the FEOM with a proportional integral controller, of which the voltage output is directly converted to the measured magnetic field intensity, the resonance peak is locked to the environmental magnetic field. The measurement data we have achieved are well matched with the data measured by a commercial fluxgate magnetometer within 2 nT, and the sensitivity is better than 8 pT/√Hz in a parallel B field.

  2. An Innovative Procedure for Calibration of Strapdown Electro-Optical Sensors Onboard Unmanned Air Vehicles

    Directory of Open Access Journals (Sweden)

    Attilio Rispoli

    2010-01-01

    Full Text Available This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms.

  3. Bandwidth manipulation of quantum light by an electro-optic time lens

    CERN Document Server

    Karpinski, Michal; Wright, Laura J; Smith, Brian J

    2016-01-01

    The ability to manipulate the spectral-temporal waveform of optical pulses has enabled a wide range of applications from ultrafast spectroscopy to high-speed communications. Extending these concepts to quantum light has the potential to enable breakthroughs in optical quantum science and technology. However, filtering and amplifying often employed in classical pulse shaping techniques are incompatible with non-classical light. Controlling the pulsed mode structure of quantum light requires efficient means to achieve deterministic, unitary manipulation that preserves fragile quantum coherences. Here we demonstrate an electro-optic method for modifying the spectrum of non-classical light by employing a time lens. In particular we show highly-efficient wavelength-preserving six-fold compression of single-photon spectral intensity bandwidth, enabling over a two-fold increase of single-photon flux into a spectrally narrowband absorber. These results pave the way towards spectral-temporal photonic quantum informati...

  4. Selecting among competing models of electro-optic, infrared camera system range performance

    Science.gov (United States)

    Nichols, Jonathan M.; Hines, James E.; Nichols, James D.

    2013-01-01

    Range performance is often the key requirement around which electro-optical and infrared camera systems are designed. This work presents an objective framework for evaluating competing range performance models. Model selection based on the Akaike’s Information Criterion (AIC) is presented for the type of data collected during a typical human observer and target identification experiment. These methods are then demonstrated on observer responses to both visible and infrared imagery in which one of three maritime targets was placed at various ranges. We compare the performance of a number of different models, including those appearing previously in the literature. We conclude that our model-based approach offers substantial improvements over the traditional approach to inference, including increased precision and the ability to make predictions for some distances other than the specific set for which experimental trials were conducted.

  5. Measurement of Wave Electric Fields in Plasmas by Electro-Optic Probe

    CERN Document Server

    Nishiura, M; Mushiake, T; Kawazura, Y; Osawa, R; Fujinami, K; Yano, Y; Saitoh, H; Yamasaki, M; Kashyap, A; Takahashi, N; Nakatsuka, M; Fukuyama, A

    2016-01-01

    Electric field measurement in plasmas permits quantitative comparison between the experiment and the simulation in this study. An electro-optic (EO) sensor based on Pockels effect is demonstrated to measure wave electric fields in the laboratory magnetosphere of the RT-1 device with high frequency heating sources. This system gives the merits that electric field measurements can detect electrostatic waves separated clearly from wave magnetic fields, and that the sensor head is separated electrically from strong stray fields in circumference. The electromagnetic waves are excited at the double loop antenna for ion heating in electron cyclotron heated plasmas. In the air, the measured wave electric fields are in good absolute agreement with those predicted by the TASK/WF2 code. In inhomogeneous plasmas, the wave electric fields in the peripheral region are enhanced compared with the simulated electric fields. The potential oscillation of the antenna is one of the possible reason to explain the experimental resu...

  6. Suppression of Classical and Quantum Radiation Pressure Noise via Electro-Optic Feedback

    CERN Document Server

    Buchler, B C; Shaddock, D A; Ralph, T C; McClelland, D E; Buchler, Ben C.; Gray, Malcolm B.; Shaddock, Daniel A.; Ralph, Timothy C.; Clelland, David E. Mc

    1998-01-01

    We present theoretical results that demonstrate a new technique to be used to improve the sensitivity of thermal noise measurements: intra-cavity intensity stabilisation. It is demonstrated that electro-optic feedback can be used to reduce intra-cavity intensity fluctuations, and the consequent radiation pressure fluctuations, by a factor of two below the quantum noise limit. We show that this is achievable in the presence of large classical intensity fluctuations on the incident laser beam. The benefits of this scheme are a consequence of the sub-Poissonian intensity statistics of the field inside a feedback loop, and the quantum non-demolition nature of radiation pressure noise as a readout system for the intra-cavity intensity fluctuations.

  7. Non-Linear Sigma Model on Conifolds

    CERN Document Server

    Parthasarathy, R

    2002-01-01

    Explicit solutions to the conifold equations with complex dimension $n=3,4$ in terms of {\\it{complex coordinates (fields)}} are employed to construct the Ricci-flat K\\"{a}hler metrics on these manifolds. The K\\"{a}hler 2-forms are found to be closed. The complex realization of these conifold metrics are used in the construction of 2-dimensional non-linear sigma model with the conifolds as target spaces. The action for the sigma model is shown to be bounded from below. By a suitable choice of the 'integration constants', arising in the solution of Ricci flatness requirement, the metric and the equations of motion are found to be {\\it{non-singular}}. As the target space is Ricci flat, the perturbative 1-loop counter terms being absent, the model becomes topological. The inherent U(1) fibre over the base of the conifolds is shown to correspond to a gauge connection in the sigma model. The same procedure is employed to construct the metric for the resolved conifold, in terms of complex coordinates and the action ...

  8. Non-Linear Electrohydrodynamics in Microfluidic Devices

    Directory of Open Access Journals (Sweden)

    Jun Zeng

    2011-03-01

    Full Text Available Since the inception of microfluidics, the electric force has been exploited as one of the leading mechanisms for driving and controlling the movement of the operating fluid and the charged suspensions. Electric force has an intrinsic advantage in miniaturized devices. Because the electrodes are placed over a small distance, from sub-millimeter to a few microns, a very high electric field is easy to obtain. The electric force can be highly localized as its strength rapidly decays away from the peak. This makes the electric force an ideal candidate for precise spatial control. The geometry and placement of the electrodes can be used to design electric fields of varying distributions, which can be readily realized by Micro-Electro-Mechanical Systems (MEMS fabrication methods. In this paper, we examine several electrically driven liquid handling operations. The emphasis is given to non-linear electrohydrodynamic effects. We discuss the theoretical treatment and related numerical methods. Modeling and simulations are used to unveil the associated electrohydrodynamic phenomena. The modeling based investigation is interwoven with examples of microfluidic devices to illustrate the applications.

  9. Quantification of helicopter rotor downwash effects on electro-optical defensive aids suites

    Science.gov (United States)

    Seiffer, Dirk P.; Eisele, Christian; Henriksson, Markus; Sjöqvist, Lars; Möller, Sebastian; Togna, Fabio; Velluet, Marie-Thérèse

    2015-10-01

    The performance of electro-optical platform protection systems can be degraded significantly by the propagation environment around the platform. This includes aero-optical effects and zones of severe turbulence generated by engine exhausts. For helicopters rotor tip vortices and engine exhaust gases that are pressed down by the rotor airflow form the so called downwash phenomena. The downwash is a source for perturbations. A wide range of spatial and temporal fluctuations in the refractive index of air can occur. The perturbations from the turbulent flow cause detrimental effects on energy delivery, angle of arrival fluctuations, jam-code transmission, tracking accuracy and imaging performance in general. Therefore the effects may especially have a severe impact on the performance of laser-based protection systems like directed infrared countermeasures (DIRCM). The chain from passive missile detection and warning to obtaining an optical break-lock by the use of an active laser system will be influenced. To anticipate the installed performance of an electro-optical defensive aids suite (DAS) for helicopter platforms it is necessary to develop models for the prediction of the perturbations. Modelled results have to be validated against experimental findings. However, the data available in open literature on the effects of rotor downwash from helicopters on optical propagation is very limited. To collect necessary data and to obtain a first impression about the magnitude of occurring effects the European defence agency group (EDA) on "airborne platform effects on lasers and warning sensors (ALWS)" decided to design and perform a field trial on the premises of the Italian Air Force Flight Test Center in Pratica di Mare, Italy. ALWS is a technical arrangement under the Europa MoU among France, Germany, Italy, Sweden and the United Kingdom.

  10. A novel electro-optical pump-probe system for bioelectromagnetic investigations

    Science.gov (United States)

    De Angelis, Annalisa; Couderc, Vincent; Leproux, Philippe; Labruyère, Alexis; Tonello, Alessandro; El Amari, Saad; Arnaud-Cormos, Delia; Leveque, Philippe

    2012-10-01

    In the area of bioelectromagnetic studies there is a growing interest to understand the mechanisms leading to nanosecond electric fields induced electroporation. Real-time imaging techniques at molecular level could probably bring further advances on how electric fields interact with living cells. However the investigations are limited by the present-day lack of these kinds of advanced instrumentations. In this context, we present an innovative electro-optical pump-probe system. The aim of our project is to provide a performing and compact device for electrical stimulation and multiplex Coherent anti-Stokes Raman Scattering (M-CARS) imaging of biological cells at once. The system consists of a 1064 nm sub-nanosecond laser source providing both a monochromatic pump and a polychromatic Stokes optical beam used in a CARS process, as well as the trigger beam for the optoelectronic switching-based electrical pulse generator. The polychromatic Stokes beam (from 600 to 1700 nm) results from a supercontinuum generation in a photonic crystal fiber (PCF). A detailed spectro-temporal characterization of such a broadband spectrum shows the impact of the nonlinear propagation in the fiber on the Stokes wave. Despite the temporal distortions observable on Stokes pulse profiles, their spectral synchronization with the pump pulse remains possible and efficient in the interesting region between 1100 nm and 1700 nm. The electrical stimulation device consists of a customized generator combining microstrip-line technology and laser-triggered photoconductive semiconductor switches. Our experimental characterization highlights the capability for such a generator to control the main pulse parameters (profile, amplitude and duration) and to be easily synchronized with the imaging system. We finally test and calibrate the system by means of a KDP crystal. The preliminary results suggest that this electro-optical system provides a suitable tool for real-time investigation of

  11. Ultra-light weight undamped tuned dynamic absorber for cryogenically cooled infrared electro-optic payload

    Science.gov (United States)

    Veprik, Alexander; Babitsky, Vladimir

    2017-04-01

    Attenuation of tonal cryocooler induced vibration in infrared electro-optical payloads may be achieved by using of Tuned Dynamic Absorber (TDA) which is, generally speaking, a passive, weakly damped mass-spring system the resonant frequency of which is precisely matched with the driving frequency. Added TDA results in a favorable modification of the frequency response functions of combined structure. In particular, a favorable antiresonant notch appears at the frequency of tonal excitation along with the adjacent secondary resonance, the width and depth of which along with its closeness to the secondary resonance are strongly dependent on the mass and damping ratios. Using heavier TDA favorably results in wider and deeper antiresonant notch along with increased gap between antiresonant and resonant frequencies. Lowering damping in TDA favorably results in deepening the antiresonant notch. The weight of TDA is usually subjected to tight design constrains. Use of lightweight TDA not only diminishes the attainable performance but also complicates the procedure of frequency matching. Along these lines, even minor frequency deviations may negate the TDA performance and even result in TDA failure in case of resonant build up. The authors are presenting theoretical and practical aspects of designing and constructing ultra-light weight TDA in application to vibration attenuation of electro-optical infrared payload relying on Split Stirling linear cryocooler, the driving frequency of which is fixed and may be accurately tuned and maintained using a digital controller over the entire range of working conditions and lifetime; the lack of mass ratio is compensated by minimizing the damping ratio. In one particular case, in excess of 100-fold vibration attenuation has been achieved by adding as little as 5% to the payload weight.

  12. Electro-optical circuit board with single-mode glass waveguide optical interconnects

    Science.gov (United States)

    Brusberg, Lars; Neitz, Marcel; Pernthaler, Dominik; Weber, Daniel; Sirbu, Bogdan; Herbst, Christian; Frey, Christopher; Queisser, Marco; Wöhrmann, Markus; Manessis, Dionysios; Schild, Beatrice; Oppermann, Hermann; Eichhammer, Yann; Schröder, Henning; Hâkansson, Andreas; Tekin, Tolga

    2016-03-01

    A glass optical waveguide process has been developed for fabrication of electro-optical circuit boards (EOCB). Very thin glass panels with planar integrated single-mode waveguides can be embedded as a core layer in printed circuit boards for high-speed board-level chip-to-chip and board-to-board optical interconnects over an optical backplane. Such singlemode EOCBs will be needed in upcoming high performance computers and data storage network environments in case single-mode operating silicon photonic ICs generate high-bandwidth signals [1]. The paper will describe some project results of the ongoing PhoxTroT project, in which a development of glass based single-mode on-board and board-to-board interconnection platform is successfully in progress. The optical design comprises a 500 μm thin glass panel (Schott D263Teco) with purely optical layers for single-mode glass waveguides. The board size is accommodated to the mask size limitations of the fabrication (200 mm wafer level process, being later transferred also to larger panel size). Our concept consists of directly assembling of silicon photonic ICs on cut-out areas in glass-based optical waveguide panels. A part of the electrical wiring is patterned by thin film technology directly on the glass wafer surface. A coupling element will be assembled on bottom side of the glass-based waveguide panel for 3D coupling between board-level glass waveguides and chip-level silicon waveguides. The laminate has a defined window for direct glass access for assembling of the photonic integrated circuit chip and optical coupling element. The paper describes the design, fabrication and characterization of glass-based electro-optical circuit board with format of (228 x 305) mm2.

  13. Nuclear reactor pulse tracing using a CdZnTe electro-optic radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: nuclearengg@gmail.com [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Geuther, Jeffrey A. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Neihart, James L.; Riedel, Todd A. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Rojeski, Ronald A. [Nanometrics, Inc., 1550 Buckeye Drive, Milpitas CA 95035 (United States); Ugorowski, Philip B.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States)

    2012-07-11

    CdZnTe has previously been shown to operate as an electro-optic radiation detector by utilizing the Pockels effect to measure steady-state nuclear reactor power levels. In the present work, the detector response to reactor power excursion experiments was investigated. Peak power levels during an excursion were predicted to be between 965 MW and 1009 MW using the Fuchs-Nordheim and Fuchs-Hansen models and confirmed with experimental data from the Kansas State University TRIGA Mark II nuclear reactor. The experimental arrangement of the Pockels cell detector includes collimated laser light passing through a transparent birefringent crystal, located between crossed polarizers, and focused upon a photodiode. The birefringent crystal, CdZnTe in this case, is placed in a neutron beam emanating from a nuclear reactor beam port. After obtaining the voltage-dependent Pockels characteristic response curve with a photodiode, neutron measurements were conducted from reactor pulses with the Pockels cell set at the 1/4 and 3/4 wave bias voltages. The detector responses to nuclear reactor pulses were recorded in real-time using data logging electronics, each showing a sharp increase in photodiode current for the 1/4 wave bias, and a sharp decrease in photodiode current for the 3/4 wave bias. The polarizers were readjusted to equal angles in which the maximum light transmission occurred at 0 V bias, thereby, inverting the detector response to reactor pulses. A high sample rate oscilloscope was also used to more accurately measure the FWHM of the pulse from the electro-optic detector, 64 ms, and is compared to the experimentally obtained FWHM of 16.0 ms obtained with the {sup 10}B-lined counter.

  14. An airborne thematic thermal infrared and electro-optical imaging system

    Science.gov (United States)

    Sun, Xiuhong; Shu, Peter

    2011-08-01

    This paper describes an advanced Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System (ATTIREOIS) and its potential applications. ATTIREOIS sensor payload consists of two sets of advanced Focal Plane Arrays (FPAs) - a broadband Thermal InfraRed Sensor (TIRS) and a four (4) band Multispectral Electro-Optical Sensor (MEOS) to approximate Landsat ETM+ bands 1,2,3,4, and 6, and LDCM bands 2,3,4,5, and 10+11. The airborne TIRS is 3-axis stabilized payload capable of providing 3D photogrammetric images with a 1,850 pixel swathwidth via pushbroom operation. MEOS has a total of 116 million simultaneous sensor counts capable of providing 3 cm spatial resolution multispectral orthophotos for continuous airborne mapping. ATTIREOIS is a complete standalone and easy-to-use portable imaging instrument for light aerial vehicle deployment. Its miniaturized backend data system operates all ATTIREOIS imaging sensor components, an INS/GPS, and an e-Gimbal™ Control Electronic Unit (ECU) with a data throughput of 300 Megabytes/sec. The backend provides advanced onboard processing, performing autonomous raw sensor imagery development, TIRS image track-recovery reconstruction, LWIR/VNIR multi-band co-registration, and photogrammetric image processing. With geometric optics and boresight calibrations, the ATTIREOIS data products are directly georeferenced with an accuracy of approximately one meter. A prototype ATTIREOIS has been configured. Its sample LWIR/EO image data will be presented. Potential applications of ATTIREOIS include: 1) Providing timely and cost-effective, precisely and directly georeferenced surface emissive and solar reflective LWIR/VNIR multispectral images via a private Google Earth Globe to enhance NASA's Earth science research capabilities; and 2) Underflight satellites to support satellite measurement calibration and validation observations.

  15. TOD: a new method to characterize electro-optical system performance

    Science.gov (United States)

    Bijl, Piet; Valeton, J. M.

    1998-08-01

    The current standard to characterize Electro-Optical system performance is the MRTD (Minimum Resolvable Temperature Difference) for thermal imagers and the MRC (Minimum Resolvable Contrast) for visual devices. This standard has at least three serious disadvantages: (1) the standard 4-bar test pattern is theoretically and practically unsuitable for 1D or 2D spatially sampled systems such as pixel-array camera's, (2) spatial phase is not taken into account, and (3) the results depend on the observer's subjective decision criterion. We propose an adequate and easily applicable alternative: TOD (Triangle Orientation Discrimination threshold). The TOD is based on an improved test pattern, a better defined observer task, and a solid psychophysical measurement procedure. The new method has theoretical and practical advantages: it is suitable for pixel-array camera's, scanning systems and other (Electro-) Optical imaging systems in both the thermal and vision domain, it has a close relationship to real target acquisition, and the observer task is easy. The results are free from observer bias and allow statistical significance tests. The method lends itself very well for automatic measurement, and can be extended for future sensor systems that include advanced image processing. The TOD curve can be implemented easily in a TA model such as ACQUIRE. An observer performance study with real targets shows that the TOD curve predicts TA performance better than the MRC does. The method has been implemented successfully in a thermal imager field test apparatus called TIPI, and may be implemented in current MRTD and MRC test equipment with little effort.

  16. 2-port internal model control for gyro stabilized platform of electro-optical tracking system

    Science.gov (United States)

    Xia, Yun-xia; Bao, Qi-liang; Li, Zhi-jun; Wu, Qiong-yan

    2012-06-01

    Line-of-sight stabilized system, which can be used to isolate the vibration of the moving bed and the disturbance of environment, is the most important part of an electro-optical tracking system. The steady precision and robustness are the key issues of recent researches. In this paper, a novel control approach so called 2-Port Internal Model Control (2-PIMC) for line-of-sight stabilized system is proposed. By adding a parallel feedback control loop on the basis of Internal Model Control (IMC), the 2-PIMC method can improve precision while it also has strong robustness as the IMC. The robustness and the static error of 2-PIMC method were subsequently analyzed. Based on this novel method, Simulation and experiment are both carried out for a gyro stabilized platform of electro-optical tracking system. The experiments include a shaking table which can generate disturbance as the moving bed and a gyro stabilized platform which is mounted on the shaking table. The experimental result indicated that the gyro stabilized platform using 2-PIMC method is accurate and effective. Comparing with PI control, the following error and disturbance restraining error were both greatly improved at low-frequency and mid-frequency by the 2-PIMC method proposed. The improvement of precision is more than 10dB at 4Hz. In addition, the 2-PIMC method doesn't need any extra sensors for the platform and it's easy for parameters regulation. It can be concluded that the2-PIMC method is a new approach for the high-performance gyro stabilized platform and might have broad application prospect.

  17. Non-Linear Unit Root Properties of Crude Oil Production

    OpenAIRE

    Svetlana Maslyuk; Russell Smyth

    2007-01-01

    While there is good reason to expect crude oil production to be non-linear, previous studies that have examined the stochastic properties of crude oil production have assumed that crude oil production follows a linear process. If crude oil production is a non-linear process, conventional unit root tests, which assume linear and systematic adjustment, could interpret departure from linearity as permanent stochastic disturbances. The objective of this paper is to test for non-linearities and un...

  18. Non-Gaussianity vs. non-linearity of cosmological perturbations

    CERN Document Server

    Verde, L

    2001-01-01

    Following the discovery of the CMB, the hot big-bang model has become the standard cosmological model. In this theory, small primordial fluctuations are subsequently amplified by gravity to form the large-scale structure seen today. Different theories for unified models of particle physics, lead to different predictions for the statistical properties of the primordial fluctuations, that can be divided in two classes: gaussian and non-gaussian. Convincing evidence against or for gaussian initial conditions would rule out many scenarios and point us towards a physical theory for the origin of structures. The statistical distribution of cosmological perturbations, as we observe them, can deviate from the gaussian distribution in several different ways. Even if perturbations start off gaussian, non-linear gravitational evolution can introduce non-gaussian features. Additionally, our knowledge of the Universe comes principally from the study of luminous material such as galaxies, but these might not be faithful tr...

  19. Non-linear scalable TFETI domain decomposition based contact algorithm

    Science.gov (United States)

    Dobiáš, J.; Pták, S.; Dostál, Z.; Vondrák, V.; Kozubek, T.

    2010-06-01

    The paper is concerned with the application of our original variant of the Finite Element Tearing and Interconnecting (FETI) domain decomposition method, called the Total FETI (TFETI), to solve solid mechanics problems exhibiting geometric, material, and contact non-linearities. The TFETI enforces the prescribed displacements by the Lagrange multipliers, so that all the subdomains are 'floating', the kernels of their stiffness matrices are known a priori, and the projector to the natural coarse grid is more effective. The basic theory and relationships of both FETI and TFETI are briefly reviewed and a new version of solution algorithm is presented. It is shown that application of TFETI methodology to the contact problems converts the original problem to the strictly convex quadratic programming problem with bound and equality constraints, so that the effective, in a sense optimal algorithms is to be applied. Numerical experiments show that the method exhibits both numerical and parallel scalabilities.

  20. Effect of higher order non-linearity in frequency variation of self-phase modulation in optical fiber communication

    Institute of Scientific and Technical Information of China (English)

    Abhijit Sinha; Sourangshu Mukhopadhyay

    2004-01-01

    In optical soliton propagation through a single mode optical fiber,it is established that self-phase mod ulation is maintained by the third order non-linearity of the silica-based glass material of the fiber.In this paper we show that the fifth order non-linearity has also some contribution in frequency variation of self-phase modulation.

  1. Modeling, Simulation, and Characterization of Electro-Optic Polymer Waveguide Devices.

    Science.gov (United States)

    Ma, Jiong

    The primary objective of this thesis is to investigate the properties of optical polymer waveguides and switches, develop a phenomenological CAD tool, and to use this phenomenological tool to design optical polymer devices for high-speed interconnects in VLSI systems. In the investigations of optical polymer waveguides, a new phenomenological bleaching model that is able to predict optical index profiles for photobleached polymer films was developed. The theoretical model shows good agreement with measured results for the effective index and optical field distributions of waveguides, and the absorption of films. Based on this bleaching model, we can predict the index profile for polymer channel waveguides and formulate design rules for active optical switches and modulators. The model has been successfully applied to photobleached PMMA/DR1 and Ultem/DEDR1 waveguides. An experimental technique to determine the poling -induced optical birefringence and optical nonlinearity is also discussed. In this technique, absorption measurements are performed immediately after poling. The poling-induced index changes as a function of wavelength are obtained from the absorption changes using a Kramers-Kronig transformation. An alternative method for predicting the poling-induced index changes, requiring a combination of waveguide measurement techniques and order parameter calculations, exhibits good agreement. By combining the poling effects with the photobleaching index profile, a CAD tool has been developed to calculate the optical field distribution and loss which allows the design of active electro-optical modulators. Using the CAD tool together with an equivalent circuit model of electro-optic polymer switches, circuit level comparisons of a CMOS strip line interconnect with an external polymer modulator interconnect were performed in terms of power dissipation, bandwidth, and connection density. HSPICE was used as a circuit simulation tool. Based on this analysis, it is

  2. Design, synthesis and characterization of novel nonlinear optical chromophores for electro-optical applications

    Science.gov (United States)

    Liu, Feng

    This dissertation involves the design, synthesis and characterization of second order nonlinear optical chromophores for electro-optic applications. The design concept, that poling efficiency and macroscopic nonlinearities can be improved by modifying a chromophore's shape, has been explored. Chapter 1 gives an introduction into theoretical background of nonlinear optics and electro-optic phenomenon in organic molecules and poled polymers. Chapter 2 involves the design and synthesis of GLD-2 and GLD-3 chromophores, both with bulky substituents on the ring-fused bridge. The optical studies and HRS measurement show that the two alkyl groups on the bridge blueshift the lambdamax in chloroform by 20 nm and decrease the beta values. DSC and TGA thermal analysis show Td of GLD-2 and GLD-3 over 240°C. The maximum achievable r33 of GLD-2/PMMA is 61 pm/V, compared to the 92.4 pm/V of GLD-1/PMMA. But GLD-2/APC shows r33 of 45.2pm/V, higher than GLD-1/APC due to the improved compatibility with APC. The optical loss of 13 wt% GLD-2/PMMA at 1.55mum is 1.4 dB compared to the 2.3 dB of 17 wt% GLD-1/PMMA. Optical loss studies prove that adding two bulky substituents on bridge help attenuate electrostatic interactions. GLD-3 show deteriorated solubility in common used organic solvents, probably due to the combination of two TBDMS and two lengthy alkyl groups. Chapter 3 presents synthesis of thiophene-based chromophores with variously positioned TBDMS groups. The optical studies of these chromophores show one TBDMSO substitution on the thiophene bridge yields little influence on the lambda max in chloroform. FTCDS chromophore with two TBDMS groups, one on donor and one on thiophene bridge, shows to be the best structure with regards the thermal stability and achievable maximum EO coefficient value, 65.9 pm/V, at only 24 wt% loading density at 1.3 mum. Chapter 4 deals with three novel bridges for NLO chromophores. Synthetic methodologies of the diketone precursor of rigidified

  3. Organic non-linear optics and opto-electronics

    Science.gov (United States)

    Maldonado, J. L.; Ramos-Ortíz, G.; Rodríguez, M.; Meneses-Nava, M. A.; Barbosa-García, O.; Santillán, R.; Farfán, N.

    2010-12-01

    π-conjugated organic molecules and polymers are of great importance in physics, chemistry, material science and engineering. It is expected that, in the near future, organic materials will find widespread use in many technological applications. In the case of organic opto-electronic systems, the list of devices includes light emitting diodes (OLEDs), photovoltaic cells (OPVs), field-effect transistors (OFET), photorefractive materials for light manipulation, among others. These materials are also used for photonic applications: all-optical switching, modulators, optical correlators, plastic waveguides, all polymeric integrated circuits, solid-state lasers, and for biophotonic applications as in the case of the development of organic labels for multiphoton microscopy and photodynamic therapy. The advances in the developing of organic compounds with better mechanical, electrical, and optical (linear and non-linear) characteristics are of a great importance for this field. Here, we present the research on this area carried out at the Centro de Investigaciones en Óp-tica (CIO), in collaboration with Chemistry Departments of different institutions. This work focuses on the optical characterization of materials through several techniques such as TOF, FWM, TBC, THG Maker Fringes, HRS, Z-scan, and TPEF. Additionally, some applications, such as dynamic holography by using photorefractive polymers, and OPVs cells will be discussed.

  4. A single-shot, multiwavelength electro-optic data-acquisition system for inertial confinement fusion applications (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, W. R.; Zhao, C.; Ji, L.; Roides, R. G. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States); Miller, K. [National Security Technology, Santa Barbara, California 93111 (United States); Beeman, B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    Electro-optic data-acquisition systems encode the output from voltage-history diagnostics onto optical signals. The optical signals can propagate long distances over fiber-optic links without degrading the bandwidth of the encoded signal while protecting the recording electronics from overvoltage damage. The sinusoidal response and tolerance to high-input voltages of the Mach-Zehnder modulator used for the encoding leads to the additional advantage of a high dynamic range and a reduced need for manually swapping attenuators. We have demonstrated a single-shot, electro-optic data-acquisition system with a 600:1 dynamic range. This system provides optical isolation and a bandwidth of 6 GHz. The prototype system uses multiple optical wavelengths to allow for the multiplexing of up to eight signals onto one photodetector.

  5. Mesoporous sol-gel silica cladding for hybrid TiO2/electro-optic polymer waveguide modulators.

    Science.gov (United States)

    Enami, Yasufumi; Kayaba, Yasuhisa; Luo, Jingdong; Jen, Alex K-Y

    2014-06-30

    We report the efficient poling of an electro-optic (EO) polymer in a hybrid TiO(2)/electro-optic polymer multilayer waveguide modulator on mesoporous sol-gel silica cladding. The mesoporous sol-gel silica has nanometer-sized pores and a low refractive index of 1.24, which improves mode confinement in the 400-nm-thick EO polymer film in the modulators and prevents optical absorption from the lower Au electrode, thereby resulting in a lower half-wave voltage of the modulators. The half-wave voltage (Vπ) of the hybrid modulator fabricated on the mesoporous sol-gel silica cladding is 6.0 V for an electrode length (Le) of 5 mm at a wavelength of 1550 nm (VπLe product of 3.0 V·cm) using a low-index guest-host EO polymer (in-device EO coefficient of 75 pm/V).

  6. Electro-optic Mach-Zehnder Interferometer based Optical Digital Magnitude Comparator and 1's Complement Calculator

    Science.gov (United States)

    Kumar, Ajay; Raghuwanshi, Sanjeev Kumar

    2016-06-01

    The optical switching activity is one of the most essential phenomena in the optical domain. The electro-optic effect-based switching phenomena are applicable to generate some effective combinational and sequential logic circuits. The processing of digital computational technique in the optical domain includes some considerable advantages of optical communication technology, e.g. immunity to electro-magnetic interferences, compact size, signal security, parallel computing and larger bandwidth. The paper describes some efficient technique to implement single bit magnitude comparator and 1's complement calculator using the concepts of electro-optic effect. The proposed techniques are simulated on the MATLAB software. However, the suitability of the techniques is verified using the highly reliable Opti-BPM software. It is interesting to analyze the circuits in order to specify some optimized device parameter in order to optimize some performance affecting parameters, e.g. crosstalk, extinction ratio, signal losses through the curved and straight waveguide sections.

  7. Design of 1-bit and 2-bit magnitude comparators using electro-optic effect in Mach-Zehnder interferometers

    Science.gov (United States)

    Kumar, Santosh; Bisht, Ashish; Singh, Gurdeep; Choudhary, Kuldeep; Raina, K. K.; Amphawan, Angela

    2015-12-01

    The Mach-Zehnder interferometer (MZI) structures collectively show powerful capability in switching an input optical signal to a desired output port from a collection of output ports. Hence, it is possible to construct complex optical combinational digital circuits using the electro-optic effect constituting MZI structure as a basic building block. Optical switches have been designed for 1-bit and 2-bit magnitude comparators based on electro-optic effect using Mach-Zehnder interferometers. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. Analysis of some factors influencing the performances of proposed device has been discussed properly. The study is verified using beam propagation method.

  8. High Spatial Resolution Electro -Optic Field -Mapping for Three Orthogonal Field Components in a Micro -Structured Electrode

    Institute of Scientific and Technical Information of China (English)

    Yoshiro Matsuo; Tetsuya Kawanishi; Satoshi Oikawa; Kaoru Higuma; Masayuki Izutsu

    2003-01-01

    @@ The optically based technique of electro-optic (EO)sampling has been used for diagnosing the internal high-speed signals of integrated circuits [1]. One of the features that make the EO sampling technique very promising is a minimal probe: the EO sampling technique does not require an electrode and ground plane incorporated as part of a probe so that, compared with conventional metal probes, the invasiveness of an EO probe is minimal.

  9. High Spatial Resolution Electro -Optic Field -Mapping for Three Orthogonal Field Components in a Micro -Structured Electrode

    Institute of Scientific and Technical Information of China (English)

    Yoshiro; Matsuo; Tetsuya; Kawanishi; Satoshi; Oikawa; Kaoru; Higuma; Masayuki; Izutsu

    2003-01-01

    The optically based technique of electro-optic (EO) sampling has been used for diagnosing the internal high-speed signals of integrated circuits.One of the features that make the EO sampling technique very promising is a minimal probe: the EO sampling technique does not require an electrode and ground plane incorporated as part of a probe so that, compared with conventional metal probes, the invasiveness of an EO probe is minimal.

  10. A systematic optimization of design parameters in strained silicon waveguides to further enhance the linear electro-optic effect

    Science.gov (United States)

    Olivares, Irene; Angelova, Todora I.; Pinilla-Cienfuegos, Elena; Sanchis, Pablo

    2016-05-01

    The electro-optic Pockels effect may be generated in silicon photonics structures by breaking the crystal symmetry by means of a highly stressing cladding layer (typically silicon nitride, SiN) deposited on top of the silicon waveguide. In this work, the influence of the waveguide parameters on the strain distribution and its overlap with the optical mode to enhance the Pockels effect has been analyzed. The optimum waveguide structure have been designed based on the definition and quantification of a figure of merit. The fabrication of highly stressing SiN layers by PECVD has also been optimized to characterize the designed structures. The residual stress has been controlled during the growth process by analyzing the influence of the main deposition parameters. Therefore, two identical samples with low and high stress conditions were fabricated and electro-optically characterized to test the induced Pockels effect and the influence of carrier effects. Electro-optical modulation was only measured in the sample with the high stressing SiN layer that could be attributed to the Pockels effect. Nevertheless, the influence of carriers were also observed thus making necessary additional experiments to decouple both effects.

  11. Multi-Site Simultaneous Time-Resolved Photometry with a Low Cost Electro-Optics System

    Directory of Open Access Journals (Sweden)

    Forrest Gasdia

    2017-05-01

    Full Text Available Sunlight reflected off of resident space objects can be used as an optical signal for astrometric orbit determination and for deducing geometric information about the object. With the increasing population of small satellites and debris in low Earth orbit, photometry is a powerful tool in operational support of space missions, whether for anomaly resolution or object identification. To accurately determine size, shape, spin rate, status of deployables, or attitude information of an unresolved resident space object, multi-hertz sample rate photometry is required to capture the relatively rapid changes in brightness that these objects can exhibit. OSCOM, which stands for Optical tracking and Spectral characterization of CubeSats for Operational Missions, is a low cost and portable telescope system capable of time-resolved small satellite photometry, and is field deployable on short notice for simultaneous observation from multiple sites. We present the electro-optical design principles behind OSCOM and light curves of the 1.5 U DICE-2 CubeSat and simultaneous observations of the main body of the ASTRO-H satellite after its fragmentation event.

  12. Multi-Sensor Fusion of Infrared and Electro-Optic Signals for High Resolution Night Images

    Directory of Open Access Journals (Sweden)

    Victor Lawrence

    2012-07-01

    Full Text Available Electro-optic (EO image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF of a uniform detector array and the incoherent optical transfer function (OTF of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1 inverse filter-based IR image transformation; (2 EO image edge detection; (3 registration; and (4 blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available.

  13. Quasi-phase-matched electro-optic modulators for high-speed signal processing

    Science.gov (United States)

    Toney, James E.; Stenger, Vincent E.; Busch, James; Pontius, Peter; Clabough, Michael; Pollick, Andrea; Sriram, Sri

    2013-01-01

    This paper reports on the design, fabrication and testing of quasi-phase-matched (QPM) lithium niobate electro-optic modulators optimized for the 40-60 GHz frequency range. The device used a single-drive, coplanar-waveguide (cpw) electrode structure that provided a good balance between impedance and RF loss, and a DC Vπ.L product of approximately 10 V.cm. Ferroelectric domain engineering enabled push-pull operation with a single drive, while achieving low chirp. A custom developed pulsed poling process was used to fabricate periodic domain QPM structures in lithium niobate. QPM periods were in the range of 3 mm to 4.5 mm, depending on the design frequency. The pulse method enabled precise domain definition with a minimum of overpoling. Low-loss diffused optical waveguides were fabricated by an annealed proton exchange (APE) process. By operating in both co-propagating and counter-propagating modes, the QPM devices can be used to implement dual band RF bandpass filters simultaneously covering both 10-20 GHz and 40-60 GHz frequency bands. Arrays of QPM device structures demonstrated in this work form the basis for a reconfigurable RF photonic filter. The RF photonic QPM technology enables efficient concurrent antenna remoting and filtering functionality. Applications of the technology include fiber radio for cellular access and finite impulse response filters for wideband electronic warfare receivers.

  14. Optimization design of optical waveguide in Mach-Zehnder electro-optical polymer modulator

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan; ZHANG Xiao-xia; LIAO Jin-kun

    2011-01-01

    @@ In order to reduce transmission loss of the optical waveguide in Mach-Zehnder (M-Z) electro-optical (EO) polymer modulator,the basic iterative formula of semi-vector finite-difference beam propagation method (FD-BPM) is obtained from the scalar wave equation.The transition waveguide is combined with S-type bend branch waveguide for the M-Z EO modulator in the branch waveguide.The effects of structure parameters such as ridge width, length of the branch waveguide and interferometer spacing on the transmission loss are systematically studied by using the semi-vector FD-BPM method.The structure is optimized as an S-sine bend branch waveguide, with rib width w=7 μm, length of branch waveguide L=1200μm and interferometer spacing G=22 μm.The results show that the optimized structure can reduce transmission loss to 0.083 dB,which have a certain reference value to the design of optical waveguide in M-Z polymer modulator.

  15. Ultra-thin silicon/electro-optic polymer hybrid waveguide modulators

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Feng; Spring, Andrew M. [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Sato, Hiromu [Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Maeda, Daisuke; Ozawa, Masa-aki; Odoi, Keisuke [Nissan Chemical Industries, Ltd., 2-10-1 Tuboi Nishi, Funabashi, Chiba 274-8507 (Japan); Aoki, Isao; Otomo, Akira [National Institute of Information and Communications Technology, 588-2 Iwaoka, Nishi-ku, Kobe 651-2492 (Japan); Yokoyama, Shiyoshi, E-mail: s-yokoyama@cm.kyushu-u.ac.jp [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan)

    2015-09-21

    Ultra-thin silicon and electro-optic (EO) polymer hybrid waveguide modulators have been designed and fabricated. The waveguide consists of a silicon core with a thickness of 30 nm and a width of 2 μm. The cladding is an EO polymer. Optical mode calculation reveals that 55% of the optical field around the silicon extends into the EO polymer in the TE mode. A Mach-Zehnder interferometer (MZI) modulator was prepared using common coplanar electrodes. The measured half-wave voltage of the MZI with 7 μm spacing and 1.3 cm long electrodes is 4.6 V at 1550 nm. The evaluated EO coefficient is 70 pm/V, which is comparable to that of the bulk EO polymer film. Using ultra-thin silicon is beneficial in order to reduce the side-wall scattering loss, yielding a propagation loss of 4.0 dB/cm. We also investigated a mode converter which couples light from the hybrid EO waveguide into a strip silicon waveguide. The calculation indicates that the coupling loss between these two devices is small enough to exploit the potential fusion of a hybrid EO polymer modulator together with a silicon micro-photonics device.

  16. Measurement of the linear electro-optic tensor of cubic boron nitride single crystals

    Institute of Scientific and Technical Information of China (English)

    Shuang Wang; Gang Jia; Xiuhuan Liu; Shipeng Chi; Jingcheng Zhu; Yanjun Gao; Pingwei Zhou; Zhanguo Chen

    2012-01-01

    The transverse electro-optic (EO) modulation system is built based on cubic boron nitride (cBN) single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of the system includes two parts that can be measured respectively and the value of elements in the linear EO tensor of the cBN crystal can be obtained.This method does not need to measure the absolute light intensity.All of the surfaces of the tiny cBN crystals whose hardness is next to the hardest diamonds are {111} planes.The rectangular parallelepiped cBN samples are obtained by cleaving along {110} planes and subsequently grinding and polishing {112} planes of the tiny octahedral cBN flakes.Three identical non-zero elements of the EO tensor of the cBN crystal are measured via two sample configurations,and the measured results are very close,about 3.68 and 3.95 pm/V,respectively,which are larger than the linear EO coefficients of the general Ⅲ-Ⅴ compounds.

  17. Dielectric and electro-optic measurements of nematic liquid crystals doped with carbon nanotubes

    Science.gov (United States)

    Peterson, Matthew; Georgiev, Georgi; Atherton, Timothy; Cebe, Peggy

    We studied the effects of carbon nanotubes (CNTs) on the dielectric and electro-optic properties of nematic 5CB liquid crystals (LCs). Samples containing 0.01%, 0.10% and 1.00% CNTs by weight were prepared. Anti- parallel rubbed cells with a nominal thickness of 10 μm were prepared using indium tin oxide coated glass cells and a polyimide alignment layer. The capacitance and dissipation factor were measured using an Agilent 4284A precision LCR meter. From these measurements, the complex dielectric permittivity was determined as a function of frequency. Analysis of the low frequency regime (f <1000 Hz) indicates that 5CB samples containing CNTs have a higher conductance than neat samples. The Fréedericksz transition critical voltage was noted by a sharp increase in capacitance after an initial plateau. Numerical simulations of CNT-facilitated switching show that polarization induced on the nanotubes from capacitive effects can significantly reduce the critical voltage in DC electric fields, in agreement with experimental results. Measurements of the critical voltage over a range of frequencies will also be presented. Research was supported by the National Science Foundation, DMR1206010.

  18. Bandwidth manipulation of quantum light by an electro-optic time lens

    Science.gov (United States)

    Karpiński, Michał; Jachura, Michał; Wright, Laura J.; Smith, Brian J.

    2017-01-01

    The ability to manipulate the spectral-temporal waveform of optical pulses has enabled a wide range of applications from ultrafast spectroscopy to high-speed communications. Extending these concepts to quantum light has the potential to enable breakthroughs in optical quantum science and technology. However, filtering and amplifying often employed in classical pulse shaping techniques are incompatible with non-classical light. Controlling the pulsed mode structure of quantum light requires efficient means to achieve deterministic, unitary manipulation that preserves fragile quantum coherences. Here, we demonstrate an electro-optic method for modifying the spectrum of non-classical light by employing a time lens. In particular, we show highly efficient, wavelength-preserving, sixfold compression of single-photon spectral intensity bandwidth, enabling over a twofold increase of single-photon flux into a spectrally narrowband absorber. These results pave the way towards spectral-temporal photonic quantum information processing and facilitate interfacing of different physical platforms where quantum information can be stored or manipulated.

  19. Electro-optic metal-insulator-semiconductor-insulator-metal Mach-Zehnder plasmonic modulator

    Science.gov (United States)

    Thomas, Roney; Ikonic, Zoran; Kelsall, Robert W.

    2012-01-01

    The performance of a CMOS-compatible electro-optic Mach-Zehnder plasmonic modulator is investigated using electromagnetic and carrier transport simulations. Each arm of the Mach-Zehnder device comprises a metal-insulator-semiconductor-insulator-metal (MISIM) structure on a buried oxide substrate. Quantum mechanical effects at the oxide/semiconductor interfaces were considered in the calculation of electron density profiles across the structure, in order to determine the refractive index distribution and its dependence on applied bias. This information was used in finite element simulations of the electromagnetic modes within the MISIM structure in order to determine the Mach-Zehnder arm lengths required to achieve destructive interference and the corresponding propagation loss incurred by the device. Both inversion and accumulation mode devices were investigated, and the layer thicknesses and height were adjusted to optimise the device performance. A device loss of <8 dB is predicted for a MISIM structure with a 25 nm thick silicon layer, for which the device length is <3 μm, and <5 dB loss is predicted for the limiting case of a 5 nm thick silicon layer in a 1.2 μm long device: in both cases, the maximum operating voltage is 7.5 V.

  20. Single-shot time-resolved THz spectroscopy using non-collinear electro-optic imaging

    Science.gov (United States)

    Wang, Zhenyou; Su, Fuhai; Hegmann, Frank A.

    2010-03-01

    We demonstrate a technique for rapid substance identification via single-shot, coherent THz imaging using non-collinear electro-optic sampling. A THz probe pulse generated in ZnTe is transmitted through the sample then focused on a (110) ZnTe detection crystal. An 800nm, 100fs optical pulse employed as a sampling beam passes through the ZnTe detection crystal at an angle of 7^o relative to the THz beam.footnotetextT. Yasuda et al., Opt. Commun. 267, 128 (2006) The THz field induced birefringence is resolved as a variation of the intensity of the sampling pulse transmitted through a crossed polarizer. The modified sampling beam spot is imaged using a CCD camera. Because of the non-collinear geometry, the spatial overlap between the THz field and the optical pulse depends on the temporal position within the THz waveform. Consequently, we obtain high-resolution 2D images of the THz waveform without scanning the relative path length. The resolution of the absorption spectra extracted from wet paper and lactose using the single-shot imaging approach is comparable to the resolution obtained through conventional scanning lock-in measurements. Possible applications for substance detection are discussed.

  1. Electro-optic delay oscillator with nonlocal nonlinearity: Optical phase dynamics, chaos, and synchronization.

    Science.gov (United States)

    Lavrov, Roman; Peil, Michael; Jacquot, Maxime; Larger, Laurent; Udaltsov, Vladimir; Dudley, John

    2009-08-01

    We demonstrate experimentally how nonlinear optical phase dynamics can be generated with an electro-optic delay oscillator. The presented architecture consists of a linear phase modulator, followed by a delay line, and a differential phase-shift keying demodulator (DPSK-d). The latter represents the nonlinear element of the oscillator effecting a nonlinear transformation. This nonlinearity is considered as nonlocal in time since it is ruled by an intrinsic differential delay, which is significantly greater than the typical phase variations. To study the effect of this specific nonlinearity, we characterize the dynamics in terms of the dependence of the relevant feedback gain parameter. Our results reveal the occurrence of regular GHz oscillations (approximately half of the DPSK-d free spectral range), as well as a pronounced broadband phase-chaotic dynamics. Beyond this, the observed dynamical phenomena offer potential for applications in the field of microwave photonics and, in particular, for the realization of novel chaos communication systems. High quality and broadband phase-chaos synchronization is also reported with an emitter-receiver pair of the setup.

  2. TADPOLE for longitudinal electron-bunch diagnostics based on electro-optic upconversion

    Energy Technology Data Exchange (ETDEWEB)

    Schwinkendorf, Jan-Patrick, E-mail: jan-patrick.schwinkendorf@desy.de; Wunderlich, Steffen, E-mail: steffen.wunderlich@desy.de; Schaper, Lucas; Schmidt, Bernhard; Osterhoff, Jens

    2014-03-11

    Electron-bunch diagnostics are desired to utilize unambiguous, non-destructive, single-shot techniques. Various methods fulfill the latter two demands, but feature significant ambiguities and constraints in the reconstruction of time-domain electron-bunch profiles, e.g. uncertainties arising from the phase retrieval of coherent radiation using the Kramers–Kronig relation. We present a novel method of measuring the spectral phase. The measurement is based on upconversion in an electro-optic crystal, where the THz-field spectrum of fs-electron bunches is shifted to the near-infrared. This technique allows the single-shot detection of its longitudinal form factor in both, amplitude and phase. The spectral phase and amplitude information is measured and thus the temporal profile reconstructed using temporal analysis by dispersing a pair of light E-fields, also known as TADPOLE. This is a combination of frequency resolved optical gating (FROG) and spectral interferometry, enabling the temporal measurement of low-power laser pulses. In this procedure, a narrow-bandwidth laser pulse detecting the longitudinal variations in the transverse electric field of an electron bunch via frequency mixing is interfered with a broadband and FROG-characterized reference pulse. The longitudinal beam profile may therefore be unambiguously inferred from the generated interferogram and the detected spectral-phase-information of the reference pulse.

  3. TADPOLE for longitudinal electron-bunch diagnostics based on electro-optic upconversion

    Energy Technology Data Exchange (ETDEWEB)

    Schwinkendorf, Jan-Patrick; Wunderlich, Steffen; Schmidt, Bernhard; Osterhoff, Jens [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-01

    Electron-bunch diagnostics are desired to utilize unambiguous, non-destructive, single-shot techniques. Various methods fulfill the latter two demands, but feature significant ambiguities and constraints in the reconstruction of a time-domain electron-bunch profile, as for example uncertainties due to the phase retrieval of coherent radiation using the Kramers-Kronig relation. We present a novel method of upconverting the THz-field spectrum of fs electron bunches at the free-electron laser FLASH into the near-infrared in an electro-optic crystal. This technique allows the single-shot detection of its longitudinal form factor in both, amplitude and phase. The spectral phase and amplitude information is measured and thus the temporal profile reconstructed using temporal analysis by dispersing a pair of light E-fields, also known as TADPOLE. This is a combination of frequency resolved optical gating (FROG) and spectral interferometry, which enables the temporal measurement of low-power laser pulses. In this experiment, a narrow-bandwidth laser pulse detecting the longitudinal electric field of an electron bunch is interfered with a broadband and FROG-characterized reference pulse. The longitudinal beam profile may therefore be unambiguously inferred from the generated interferogram and the detected spectral-phase-information of the reference pulse.

  4. Multi-Site Simultaneous Time-Resolved Photometry with a Low Cost Electro-Optics System.

    Science.gov (United States)

    Gasdia, Forrest; Barjatya, Aroh; Bilardi, Sergei

    2017-05-30

    Sunlight reflected off of resident space objects can be used as an optical signal for astrometric orbit determination and for deducing geometric information about the object. With the increasing population of small satellites and debris in low Earth orbit, photometry is a powerful tool in operational support of space missions, whether for anomaly resolution or object identification. To accurately determine size, shape, spin rate, status of deployables, or attitude information of an unresolved resident space object, multi-hertz sample rate photometry is required to capture the relatively rapid changes in brightness that these objects can exhibit. OSCOM, which stands for Optical tracking and Spectral characterization of CubeSats for Operational Missions, is a low cost and portable telescope system capable of time-resolved small satellite photometry, and is field deployable on short notice for simultaneous observation from multiple sites. We present the electro-optical design principles behind OSCOM and light curves of the 1.5 U DICE-2 CubeSat and simultaneous observations of the main body of the ASTRO-H satellite after its fragmentation event.

  5. Miniaturized Low-power Electro-optic Modulator Based on Silicon Integrated Nanophotonics and Organic Polymers

    CERN Document Server

    Zhang, Xingyu; Luo, Jingdong; Jen, Alex K -Y; Chen, Ray T

    2014-01-01

    We design and demonstrate a compact, low-power, low-dispersion and broadband optical modulator based on electro-optic (EO) polymer refilled silicon slot photonic crystal waveguide (PCW). The EO polymer is engineered for large EO activity and near-infrared transparency. The half-wave switching-voltage is measured to be V{\\pi}=0.97V over optical spectrum range of 8nm, corresponding to a record-high effective in-device r33 of 1190pm/V and V{\\pi} L of 0.291Vmm in a push-pull configuration. Excluding the slow-light effect, we estimate the EO polymer is poled with an ultra-high efficiency of 89pm/V in the slot. In addition, to achieve high-speed modulation, silicon PCW is selectively doped to reduce RC time delay. The 3-dB RF bandwidth of the modulator is measured to be 11GHz, and a modulation response up to 40GHz is observed.

  6. Complexity in electro-optic delay dynamics: modelling, design and applications.

    Science.gov (United States)

    Larger, Laurent

    2013-09-28

    Nonlinear delay dynamics have found during the last 30 years a particularly prolific exploration area in the field of photonic systems. Besides the popular external cavity laser diode set-ups, we focus in this article on another experimental realization involving electro-optic (EO) feedback loops, with delay. This approach has strongly evolved with the important technological progress made on broadband photonic and optoelectronic devices dedicated to high-speed optical telecommunications. The complex dynamical systems performed by nonlinear delayed EO feedback loop architectures were designed and explored within a huge range of operating parameters. Thanks to the availability of high-performance photonic devices, these EO delay dynamics led also to many successful, efficient and diverse applications, beyond the many fundamental questions raised from the observation of experimental behaviours. Their chaotic motion allowed for a physical layer encryption method to secure optical data, with a demonstrated capability to operate at the typical speed of modern optical telecommunications. Microwave limit cycles generated in similar EO delay oscillators showed significantly improved spectral purity thanks to the use of a very long fibre delay line. Last but not least, a novel brain inspired computational principle has been recently implemented physically in photonics for the first time, again on the basis of an EO delay dynamical system. In this latter emerging application, the computed result is obtained by a proper 'read-out' of the complex nonlinear transients emerging from a fixed point, the transient being issued by the injection of the information signal to be processed.

  7. Spatial and temporal variability in response to hybrid electro-optical stimulation

    Science.gov (United States)

    Duke, Austin R.; Lu, Hui; Jenkins, Michael W.; Chiel, Hillel J.; Jansen, E. Duco

    2012-06-01

    Hybrid electro-optical neural stimulation is a novel paradigm combining the advantages of optical and electrical stimulation techniques while reducing their respective limitations. However, in order to fulfill its promise, this technique requires reduced variability and improved reproducibility. Here we used a comparative physiological approach to aid the further development of this technique by identifying the spatial and temporal factors characteristic of hybrid stimulation that may contribute to experimental variability and/or a lack of reproducibility. Using transient pulses of infrared light delivered simultaneously with a bipolar electrical stimulus in either the marine mollusk Aplysia californica buccal nerve or the rat sciatic nerve, we determined the existence of a finite region of excitability with size altered by the strength of the optical stimulus and recruitment dictated by the polarity of the electrical stimulus. Hybrid stimulation radiant exposures yielding 50% probability of firing (RE50) were shown to be negatively correlated with the underlying changes in electrical stimulation threshold over time. In Aplysia, but not in the rat sciatic nerve, increasing optical radiant exposures (J cm-2) beyond the RE50 ultimately resulted in inhibition of evoked potentials. Accounting for the sources of variability identified in this study increased the reproducibility of stimulation from 35% to 93% in Aplysia and 23% to 76% in the rat with reduced variability.

  8. Highly Linear, Broadband Optical Modulator Based on Electro-optic Polymer

    CERN Document Server

    Zhang, Xingyu; Lin, Che-yun; Wang, Alan X; Hosseini, Amir; Chen, Ray T

    2014-01-01

    In this paper, we present the design, fabrication and characterization of a traveling wave directional coupler modulator based on electro-optic polymer, which is able to provide both high linearity and broad bandwidth. The high linearity is realized by introducing domain-inversion technique in the two-domain directional coupler. A travelling wave electrode is designed to function with bandwidth-length product of 302GHz cm, by achieving low microwave loss, excellent impedance matching and velocity matching, as well as smooth electric field profile transformation. The 3-dB bandwidth of the device is measured to be 10GHz. The spurious free dynamic range of about 110dB Hz^(2/3) is measured over the modulation frequency range 2-8GHz. To the best of our knowledge, such high linearity is first measured at the frequency up to 8GHz. In addition, a 1-to-2 multi-mode interference 3dB-splitter, a photobleached refractive index taper and a quasi-vertical taper are used to reduce the optical insertion loss of the device.

  9. Exploring electro-optic effect of impurity doped quantum dots in presence of Gaussian white noise

    Science.gov (United States)

    Pal, Suvajit; Ganguly, Jayanta; Saha, Surajit; Ghosh, Manas

    2016-01-01

    We explore the profiles of electro-optic effect (EOE) of impurity doped quantum dots (QDs) in presence and absence of noise. We have invoked Gaussian white noise in the present study. The quantum dot is doped with Gaussian impurity. Noise has been administered to the system additively and multiplicatively. A perpendicular magnetic field acts as a confinement source and a static external electric field has been applied. The EOE profiles have been followed as a function of incident photon energy when several important parameters such as electric field strength, magnetic field strength, confinement energy, dopant location, relaxation time, Al concentration, dopant potential, and noise strength possess different values. In addition, the role of mode of application of noise (additive/multiplicative) on the EOE profiles has also been scrutinized. The EOE profiles are found to be adorned with interesting observations such as shift of peak position and maximization/minimization of peak intensity. However, the presence of noise and also the pathway of its application bring about rich variety in the features of EOE profiles through some noticeable manifestations. The observations indicate possibilities of harnessing the EOE susceptibility of doped QD systems in presence of noise.

  10. Resonator-Based Silicon Electro-Optic Modulator with Low Power Consumption

    Science.gov (United States)

    Xin, Maoqing; Danner, Aaron J.; Eng Png, Ching; Thor Lim, Soon

    2009-04-01

    This paper demonstrates, via simulation, an electro-optic modulator based on a subwavelength Fabry-Perot resonator cavity with low power consumption of 86 µW/µm. This is, to the best of our knowledge, the lowest power reported for silicon photonic bandgap modulators. The device is modulated at a doped p-i-n junction overlapping the cavity in a silicon waveguide perforated with etched holes, with the doping area optimized for minimum power consumption. The surface area of the entire device is only 2.1 µm2, which compares favorably to other silicon-based modulators. A modulation speed of at least 300 MHz is detected from the electrical simulator after sidewall doping is introduced which is suitable for sensing or fiber to the home (FTTH) technologies, where speed can be traded for low cost and power consumption. The device does not rely on ultra-high Q, and could serve as a sensor, modulator, or passive filter with built-in calibration.

  11. Fast Interrogation of Fiber Bragg Gratings with Electro-Optical Dual Optical Frequency Combs.

    Science.gov (United States)

    Posada-Roman, Julio E; Garcia-Souto, Jose A; Poiana, Dragos A; Acedo, Pablo

    2016-11-26

    Optical frequency combs (OFC) generated by electro-optic modulation of continuous-wave lasers provide broadband coherent sources with high power per line and independent control of line spacing and the number of lines. In addition to their application in spectroscopy, they offer flexible and optimized sources for the interrogation of other sensors based on wavelength change or wavelength filtering, such as fiber Bragg grating (FBG) sensors. In this paper, a dual-OFC FBG interrogation system based on a single laser and two optical-phase modulators is presented. This architecture allows for the configuration of multimode optical source parameters such as the number of modes and their position within the reflected spectrum of the FBG. A direct read-out is obtained by mapping the optical spectrum onto the radio-frequency spectrum output of the dual-comb. This interrogation scheme is proposed for measuring fast phenomena such as vibrations and ultrasounds. Results are presented for dual-comb operation under optimized control. The optical modes are mapped onto detectable tones that are multiples of 0.5 MHz around a center radiofrequency tone (40 MHz). Measurements of ultrasounds (40 kHz and 120 kHz) are demonstrated with this sensing system. Ultrasounds induce dynamic strain onto the fiber, which generates changes in the reflected Bragg wavelength and, hence, modulates the amplitude of the OFC modes within the reflected spectrum. The amplitude modulation of two counterphase tones is detected to obtain a differential measurement proportional to the ultrasound signal.

  12. Graphical and Analytical Analysis of the Non-Linear PLL

    NARCIS (Netherlands)

    de Boer, Bjorn; Radovanovic, S.; Annema, Anne J.; Nauta, Bram

    The fixed width control pulses from the Bang-Bang Phase Detector in non-linear PLLs allow for operation at higher data rates than the linear PLL. The high non-linearity of the Bang- Bang Phase Detector gives rise to unwanted effects, such as limit-cycles, not yet fully described. This paper

  13. Non-linear stochastic response of a shallow cable

    DEFF Research Database (Denmark)

    Larsen, Jesper Winther; Nielsen, Søren R.K.

    2004-01-01

    The paper considers the stochastic response of geometrical non-linear shallow cables. Large rain-wind induced cable oscillations with non-linear interactions have been observed in many large cable stayed bridges during the last decades. The response of the cable is investigated for a reduced two-degrees-of-freedom...

  14. Non-linear Frequency Scaling Algorithm for FMCW SAR Data

    NARCIS (Netherlands)

    Meta, A.; Hoogeboom, P.; Ligthart, L.P.

    2006-01-01

    This paper presents a novel approach for processing data acquired with Frequency Modulated Continuous Wave (FMCW) dechirp-on-receive systems by using a non-linear frequency scaling algorithm. The range frequency non-linearity correction, the Doppler shift induced by the continuous motion and the ran

  15. Non Linear Gauge Fixing for FeynArts

    CERN Document Server

    Gajdosik, Thomas

    2007-01-01

    We review the non-linear gauge-fixing for the Standard Model, proposed by F. Boudjema and E. Chopin, and present our implementation of this non-linear gauge-fixing to the Standard Model and to the minimal supersymmetric Standard Model in FeynArts.

  16. Identification of Non-Linear Structures using Recurrent Neural Networks

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    1995-01-01

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  17. Identification of Non-Linear Structures using Recurrent Neural Networks

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  18. Identification of Non-Linear Structures using Recurrent Neural Networks

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Hansen, H. I.

    1995-01-01

    Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure.......Two different partially recurrent neural networks structured as Multi Layer Perceptrons (MLP) are investigated for time domain identification of a non-linear structure....

  19. Non-linear wave packet dynamics of coherent states

    Indian Academy of Sciences (India)

    J Banerji

    2001-02-01

    We have compared the non-linear wave packet dynamics of coherent states of various symmetry groups and found that certain generic features of non-linear evolution are present in each case. Thus the initial coherent structures are quickly destroyed but are followed by Schrödinger cat formation and revival. We also report important differences in their evolution.

  20. Laser and nonlinear optical materials: SPIE volume 681

    Energy Technology Data Exchange (ETDEWEB)

    De Shazer, L.G.

    1987-01-01

    This book contains papers arranged under the following session headings: Nonlinear optical crystals; Laser host crystals; Electro-optic and magneto-optic materials; and Characterization of optical materials.

  1. Non-linear dynamics of wind turbine wings

    DEFF Research Database (Denmark)

    Larsen, Jesper Winther; Nielsen, Søren R.K.

    2006-01-01

    by the rotation of the aerodynamic load and the curvature, as well as inertial induced non-linearities caused by the support point motion. The non-linear partial differential equations of motion in the moving frame of reference have been discretized, using the fixed base eigenmodes as a functional basis......The paper deals with the formulation of non-linear vibrations of a wind turbine wing described in a wing fixed moving coordinate system. The considered structural model is a Bernoulli-Euler beam with due consideration to axial twist. The theory includes geometrical non-linearities induced....... Important non-linear couplings between the fundamental blade mode and edgewise modes have been identified based on a resonance excitation of the wing, caused by a harmonically varying support point motion with the circular frequency omega. Assuming that the fundamental blade and edgewise eigenfrequencies...

  2. Employment of CB models for non-linear dynamic analysis

    Science.gov (United States)

    Klein, M. R. M.; Deloo, P.; Fournier-Sicre, A.

    1990-01-01

    The non-linear dynamic analysis of large structures is always very time, effort and CPU consuming. Whenever possible the reduction of the size of the mathematical model involved is of main importance to speed up the computational procedures. Such reduction can be performed for the part of the structure which perform linearly. Most of the time, the classical Guyan reduction process is used. For non-linear dynamic process where the non-linearity is present at interfaces between different structures, Craig-Bampton models can provide a very rich information, and allow easy selection of the relevant modes with respect to the phenomenon driving the non-linearity. The paper presents the employment of Craig-Bampton models combined with Newmark direct integration for solving non-linear friction problems appearing at the interface between the Hubble Space Telescope and its solar arrays during in-orbit maneuvers. Theory, implementation in the FEM code ASKA, and practical results are shown.

  3. Non-linear dielectric monitoring of biological suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Treo, E F; Felice, C J [Departamento de BioingenierIa, Universidad Nacional de Tucuman and Consejo Nacional de Investigaciones Cientificas y Tecnicas. CC327, CP4000, San Miguel de Tucuman (Argentina)

    2007-11-15

    Non-linear dielectric spectroscopy as a tool for in situ monitoring of enzyme assumes a non-linear behavior of the sample when a sinusoidal voltage is applied to it. Even many attempts have been made to improve the original experiments, all of them had limited success. In this paper we present upgrades made to a non-linear dielectric spectrometer developed and the results obtained when using different cells. We emphasized on the electrode surface, characterizing the grinding and polishing procedure. We found that the biological medium does not behave as expected, and the non-linear response is generated in the electrode-electrolyte interface. The electrochemistry of this interface can bias unpredictably the measured non-linear response.

  4. Developing Non-linear Viscous-Elastic Material Construction in ANSYS With UPFs%用ANSYS的UPFs对非线性黏弹性本构模型进行二次开发

    Institute of Scientific and Technical Information of China (English)

    吴艺

    2011-01-01

    In order to provide more references for UPFs users and break the application limitation of ANSYS in seismic area for the lack of nonlinear viscous-elastic material model, the nonlinear viucous-elastic material model was developed in ANSYS with UPFs and verified by example, and the procedure of developing material model with UPFs of ANSYS is demonstrated deliberately. Additionally, the problems encountered during this developing and their solutions and technical experiences were presented. Verifying shows that the development of nonlinear viscous-elastic material model with UPFs is successful; the solutions of programming problems and techniques are effective; the nonlinear viscous-elastic material model developed by this paper can extend application of ANSYS in geotechni-cal and structural seismic engineering; the successful UPFs experiences can be referenced by UPFs users.%UPFs是大型通用商业有限元软件ANSYS强大的二次开发工具,为了ANSYS用户在使用UPFs进行二次开发时有更多的参考并弥补ANSYS因无非线性黏弹性本构模型而在抗震工程应用中严重受限的不足,在ANSYS中用UPFs对非线性黏弹性本构模型进行二次开发和算例验证,结合实例详细演示了用ANSYS的UPFs进行本构模型二次开发的具体过程,并对应用UPFs时所碰到的实际问题及解决办法和经验技巧进行了总结。算例验证结果表明,所开发的本构模型可使ANSYS更好地应用于岩土和结构抗震工程当中,开发的技术和经验可供UPFs用户参考。

  5. Dynamics of glass-forming liquids. XIX. Rise and decay of field induced anisotropy in the non-linear regime.

    Science.gov (United States)

    Young-Gonzales, Amanda R; Samanta, Subarna; Richert, Ranko

    2015-09-14

    For glycerol and three monohydroxy alcohols, we have measured the non-linear dielectric effects resulting from the application and removal of a high dc bias electric field. The field effects are detected by virtue of a small amplitude harmonic field, from which time resolved changes in the dielectric loss are derived. The changes in permittivity are dominated by modifications of the time constants (rather than amplitudes) which display two contributions: a heating-like decrease of relaxation times that originates from the time dependent field when the bias is switched on and off and a slowing down of the dynamics resulting from the field induced reduction of configurational entropy. As observed for the electro-optical Kerr effect, the rise of the entropy change is slower than its decay, a feature that we rationalize on the basis of the quadratic dependence of the entropy change on polarization. For glycerol, the observed steady state level of the field induced shift of the glass transition temperature (+84 mK) matches the expectation based on the entropy change and its impact on dynamics via the Adam-Gibbs relation (+88 mK). For the alcohols, these non-linear effects rise and decay on the time scales of the prominent dielectric Debye process, underscoring the relation of these features to polarization anisotropy, opposed to mechanical or enthalpy relaxation which are orders of magnitude faster in these systems. A model is discussed which captures the observed magnitudes as well as time dependences in a near quantitative fashion. It is demonstrated that the high bias field modifies the response of polarization to the ac field, including a temporary change in the low field susceptibility.

  6. Non-linear theory of elasticity

    CERN Document Server

    Lurie, AI

    2012-01-01

    This book examines in detail the Theory of Elasticity which is a branch of the mechanics of a deformable solid. Special emphasis is placed on the investigation of the process of deformation within the framework of the generally accepted model of a medium which, in this case, is an elastic body. A comprehensive list of Appendices is included providing a wealth of references for more in depth coverage. The work will provide both a stimulus for future research in this field as well as useful reference material for many years to come.

  7. Inorganic nanoclusters in organic glasses - novel materials for electro-optical applications

    NARCIS (Netherlands)

    Künstle, H.C.; Möller, Martin; Künstle, Holger; Moller, M.; Kunz, Martin

    1991-01-01

    Polymer glasses which contain regularly arranged ultrasmall inorganic crystallites or clusters of CdS, CoS, NiS, ZnS have been prepared from functionalized diblock copolymers. Size and surface structure dependent variation of the ionization or redox potential respectively the band gap energy of the

  8. Numerical modelling in non linear fracture mechanics

    Directory of Open Access Journals (Sweden)

    Viggo Tvergaard

    2007-07-01

    Full Text Available Some numerical studies of crack propagation are based on using constitutive models that accountfor damage evolution in the material. When a critical damage value has been reached in a materialpoint, it is natural to assume that this point has no more carrying capacity, as is done numerically in the elementvanish technique. In the present review this procedure is illustrated for micromechanically based materialmodels, such as a ductile failure model that accounts for the nucleation and growth of voids to coalescence, and a model for intergranular creep failure with diffusive growth of grain boundary cavities leading to micro-crack formation. The procedure is also illustrated for low cycle fatigue, based on continuum damage mechanics. In addition, the possibility of crack growth predictions for elastic-plastic solids using cohesive zone models to represent the fracture process is discussed.

  9. Reproducing Kernel Particle Method for Non-Linear Fracture Analysis

    Institute of Scientific and Technical Information of China (English)

    Cao Zhongqing; Zhou Benkuan; Chen Dapeng

    2006-01-01

    To study the non-linear fracture, a non-linear constitutive model for piezoelectric ceramics was proposed, in which the polarization switching and saturation were taken into account. Based on the model, the non-linear fracture analysis was implemented using reproducing kernel particle method (RKPM). Using local J-integral as a fracture criterion, a relation curve of fracture loads against electric fields was obtained. Qualitatively, the curve is in agreement with the experimental observations reported in literature. The reproducing equation, the shape function of RKPM, and the transformation method to impose essential boundary conditions for meshless methods were also introduced. The computation was implemented using object-oriented programming method.

  10. Energia total de ruptura: um teste biomecânico para avaliação de material biológico com propriedade viscoelástica não linear Total energy of rupture: a biomechanical test to evaluate non-linear viscoelastic biological material

    Directory of Open Access Journals (Sweden)

    Feng Chung Wu

    2004-12-01

    Full Text Available Objetivo: Apresentação do teste biomecânico Energia Total de Ruptura para o estudo da resistência intrínseca de material biológico com propriedade viscoelástica não-linear representado neste trabalho por segmento íntegro de cólon descendente de rato. Métodos: Implementação do teste biomecânico Energia Total de Ruptura e do Sistema de Aquisição e Análise de dados Biomecânicos - SABI 2.0. Para esse fim, foram utilizados conceitos físico-mecânicos, computacionais e biomecânicos e como corpos de teste, 15 espécimes de cólon descendente de ratos. Resultados: O teste biomecânico Energia Total de Ruptura permitiu o cálculo da energia total acumulada necessária para promover a ruptura dos corpos de prova durante os ensaios mecânicos. Por meio da automatização e gerenciamento da aquisição e análise dos dados capturados foi possível a geração de gráficos e relatórios descritivos e estatísticos. Conclusão: Fundamentado em conceitos físico-mecânicos, computacionais e biomecânicos, o teste Energia Total de Ruptura pôde proporcionar análise matemática do comportamento dos segmentos de cólon descendente de ratos durante os ensaios, demonstrando ser um possível método de medição da resistência intrínseca desse material biológico com propriedade viscoelástica não-linear.Purpose: Presentation of the Total Energy of Rupture biomechanical test to evaluate the intrinsic resistance of the rat’s left colon which presents a non-linear viscoelastic property. Methods: Implementation of Total Energy of Rupture test (ETR and the Biomechanical Data Acquisition and Analysis System (SABI 2.0 based on physic-mechanical, computational and biomechanical concepts. Fifteen specimens of Wistar adults rat’s left colon where considered for experiments. Results: Using the TER biomechanical test it was possible calculate the accumulated total energy necessary to promote the specimens rupture during the mechanical trial. It was

  11. Laser-based satellite communication systems stabilized by non-mechanical electro-optic scanners

    Science.gov (United States)

    Ziemkiewicz, Michael; Davis, Scott R.; Rommel, Scott D.; Gann, Derek; Luey, Benjamin; Gamble, Joseph D.; Anderson, Mike

    2016-05-01

    Laser communications systems provide numerous advantages for establishing satellite-to-ground data links. As a carrier for information, lasers are characterized by high bandwidth and directionality, allowing for fast and secure transfer of data. These systems are also highly resistant to RF influences since they operate in the infrared portion of the electromagnetic spectrum, far from radio bands. In this paper we will discuss an entirely non-mechanical electro-optic (EO) laser beam steering technology, with no moving parts, which we have used to form robust 400 Mbps optical data connections through air. This technology will enable low cost, compact, and rugged free space optical (FSO) communication modules for small satellite applications. The EO beam-steerer at the heart of this system is used to maintain beam pointing as the satellite orbits. It is characterized by extremely low values for size, weight and power consumption (SWaP) - approximately 300 cm3, 300 g, and 5 W respectively, which represents a marked improvement compared to heavy, and power-consuming gimbal mechanisms. It is capable of steering a 500 mW, 1 mm short wave infrared (SWIR) beam over a field of view (FOV) of up to 50° x 15°, a range which can be increased by adding polarization gratings, which provide a coarse adjust stage at the EO beam scanner output. We have integrated this device into a communication system and demonstrated the capability to lock on and transmit a high quality data stream by modulation of SWIR power.

  12. Fast Interrogation of Fiber Bragg Gratings with Electro-Optical Dual Optical Frequency Combs

    Directory of Open Access Journals (Sweden)

    Julio E. Posada-Roman

    2016-11-01

    Full Text Available Optical frequency combs (OFC generated by electro-optic modulation of continuous-wave lasers provide broadband coherent sources with high power per line and independent control of line spacing and the number of lines. In addition to their application in spectroscopy, they offer flexible and optimized sources for the interrogation of other sensors based on wavelength change or wavelength filtering, such as fiber Bragg grating (FBG sensors. In this paper, a dual-OFC FBG interrogation system based on a single laser and two optical-phase modulators is presented. This architecture allows for the configuration of multimode optical source parameters such as the number of modes and their position within the reflected spectrum of the FBG. A direct read-out is obtained by mapping the optical spectrum onto the radio-frequency spectrum output of the dual-comb. This interrogation scheme is proposed for measuring fast phenomena such as vibrations and ultrasounds. Results are presented for dual-comb operation under optimized control. The optical modes are mapped onto detectable tones that are multiples of 0.5 MHz around a center radiofrequency tone (40 MHz. Measurements of ultrasounds (40 kHz and 120 kHz are demonstrated with this sensing system. Ultrasounds induce dynamic strain onto the fiber, which generates changes in the reflected Bragg wavelength and, hence, modulates the amplitude of the OFC modes within the reflected spectrum. The amplitude modulation of two counterphase tones is detected to obtain a differential measurement proportional to the ultrasound signal.

  13. An approach for a comprehensive automation of electro-optical (EO) sensor characterization setups

    Science.gov (United States)

    Dave, Amit; Sharma, Jitendra; Sukheja, Anil; Kumar, Sumit; Mishra, Ashish; Goswami, D. R.

    2016-05-01

    Space Applications Centre develops various electro-optical (EO) sensors for space borne platforms and inter-planetary missions. Sensor complexities vary for different applications and therefore performance evaluation and characterization pose different challenges. Performance optimization tasks demand repeated measurements and characterization needs to be done under different phases of testing. It is difficult to meet such requirements in case of short sensor development lifecycles or tight schedules. Activities which are amenable to automation are identified and targeted to reduce the manual intervention and to avoid delays due to errors and to speed up the overall activity. Laboratory instruments, either in-house developed or COTS, play an important role in automating the test setup as they have different types of interfaces and have their own complications. In order to make an automated test setup, software intelligence need to be built based on the instrument feedback and the other check points based on the test sequence. A complete automation needs machine intelligence and sufficient amount of traceability, so that the process can be easily verified for confidence. Overall software architecture should be such that it allows connecting various types of instruments, decision making based on output of the device under test, complete traceability and fault tolerance. In this paper authors have identified the activities that can be automated for various EO sensor categories and approaches are discussed for automation with radiometric calibration, spectral response measurement and focusing as test cases. Also, software architecture is presented which allows uniform access to instruments, back-end database and macro level automation process.

  14. Electro-optic testbed utilizing a dynamic range gated Rayleigh beacon for atmospheric turbulence profiling

    Science.gov (United States)

    Zuraski, Steven M.; Fiorino, Steven T.; Beecher, Elizabeth A.; Figlewski, Nathan M.; Schmidt, Jason D.; McCrae, Jack E.

    2016-10-01

    The Photometry Analysis and Optical Tracking and Evaluation System (PANOPTES) Quad Axis Telescope is a unique four axis mount Ritchey-Chretien 24 inch telescope capable of tracking objects through the zenith without axes rotation delay (no Dead Zone). This paper describes enhancement components added to the quad axis mount telescope that will enable measurements supporting novel research and field testing focused on `three-dimensional' characterization of turbulent atmospheres, mitigation techniques, and new sensing modalities. These all support research and operational techniques relating to astronomical imaging and electro-optical propagation though the atmosphere, relative to sub-meter class telescopes in humid, continental environments. This effort will use custom designed and commercial off the shelf hardware; sub-system components discussed will include a wavefront sensor system, a co-aligned beam launch system, and a fiber coupled research laser. The wavefront sensing system has the ability to take measurements from a dynamic altitude adjustable laser beacon scattering spot, a key concept that enables rapid turbulence structure parameter measurements over an altitude varied integrated atmospheric volume. The sub-components are integrated with the overall goal of measuring a height-resolved volumetric profile for the atmospheric turbulence structure parameter at the site, and developing mobile techniques for such measurements. The design concept, part selection optimization, baseline component lab testing, and initial field measurements, will be discussed in the main sections of this paper. This project is a collaborative effort between the Air Force Research Labs Sensors Directorate and the Air Force Institute of Technology Center for Directed Energy.

  15. High-frequency effects in 1D spring-mass systems with strongly non-linear inclusions

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Snaeland, S.O.; Thomsen, Jon Juel

    2010-01-01

    -like systems with embedded non-linear parts, where the masses interact with a limited set of neighbour masses. The presented analytical and numerical results show that the effective properties for LF wave propagation can be altered by establishing HF standing waves in the non-linear regions of the chain......This work generalises the possibilities to change the effective material or structural properties for low frequency (LF) wave propagation, by using high-frequency (HF) external excitation combined with strong non-linear and non-local material behaviour. The effects are demonstrated on 1D chain....... The changes affect the effective stiffness and damping of the system....

  16. Asymptotic Stability of Interconnected Passive Non-Linear Systems

    Science.gov (United States)

    Isidori, A.; Joshi, S. M.; Kelkar, A. G.

    1999-01-01

    This paper addresses the problem of stabilization of a class of internally passive non-linear time-invariant dynamic systems. A class of non-linear marginally strictly passive (MSP) systems is defined, which is less restrictive than input-strictly passive systems. It is shown that the interconnection of a non-linear passive system and a non-linear MSP system is globally asymptotically stable. The result generalizes and weakens the conditions of the passivity theorem, which requires one of the systems to be input-strictly passive. In the case of linear time-invariant systems, it is shown that the MSP property is equivalent to the marginally strictly positive real (MSPR) property, which is much simpler to check.

  17. NON-LINEAR FORCED VIBRATION OF AXIALLY MOVING VISCOELASTIC BEAMS

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaodong; Chen Li-Qun

    2006-01-01

    The non-linear forced vibration of axially moving viscoelastic beams excited by the vibration of the supporting foundation is investigated. A non-linear partial-differential equation governing the transverse motion is derived from the dynamical, constitutive equations and geometrical relations. By referring to the quasi-static stretch assumption, the partial-differential non-linearity is reduced to an integro-partial-differential one. The method of multiple scales is directly applied to the governing equations with the two types of non-linearity, respectively. The amplitude of near- and exact-resonant steady state is analyzed by use of the solvability condition of eliminating secular terms. Numerical results are presented to show the contributions of foundation vibration amplitude, viscoelastic damping, and nonlinearity to the response amplitude for the first and the second mode.

  18. Slope Safety Calculation With A Non-Linear Mohr Criterion Using Finite Element Method

    DEFF Research Database (Denmark)

    Clausen, Johan; Damkilde, Lars

    2005-01-01

    Safety factors for soil slopes are calculated using a non-linear Mohr envelope. The often used linear Mohr-Coulomb envelope tends to overestimate the safety as the material parameters are usually determined at much higher stress levels, than those present at slope failure. Experimental data...

  19. Optimal experimental design for non-linear models theory and applications

    CERN Document Server

    Kitsos, Christos P

    2013-01-01

    This book tackles the Optimal Non-Linear Experimental Design problem from an applications perspective. At the same time it offers extensive mathematical background material that avoids technicalities, making it accessible to non-mathematicians: Biologists, Medical Statisticians, Sociologists, Engineers, Chemists and Physicists will find new approaches to conducting their experiments. The book is recommended for Graduate Students and Researchers.

  20. Peri-implantitis: a complex condition with non-linear characteristics

    NARCIS (Netherlands)

    Papantonopoulos, G.H.; Gogos, C.; Housos, E.; Bountis, T.; Loos, B.G.

    2015-01-01

    Aim To cluster peri-implantitis patients and explore non-linear patterns in peri-implant bone levels. Materials and Methods Clinical and radiographic variables were retrieved from 94 implant-treated patients (340 implants, mean 7.1 ± 4.1 years in function). Kernel probability density estimations on

  1. Adaptive Kronrod-Patterson integration of non-linear finite-element matrices

    DEFF Research Database (Denmark)

    Janssen, Hans

    2010-01-01

    Efficient simulation of unsaturated moisture flow in porous media is of great importance in many engineering fields. The highly non-linear character of unsaturated flow typically gives sharp moving moisture fronts during wetting and drying of materials with strong local moisture permeability and ...

  2. Peri-implantitis: a complex condition with non-linear characteristics

    NARCIS (Netherlands)

    Papantonopoulos, G.H.; Gogos, C.; Housos, E.; Bountis, T.; Loos, B.G.

    2015-01-01

    Aim To cluster peri-implantitis patients and explore non-linear patterns in peri-implant bone levels. Materials and Methods Clinical and radiographic variables were retrieved from 94 implant-treated patients (340 implants, mean 7.1 ± 4.1 years in function). Kernel probability density estimations on

  3. Slope Safety Calculation With A Non-Linear Mohr Criterion Using Finite Element Method

    DEFF Research Database (Denmark)

    Clausen, Johan; Damkilde, Lars

    2005-01-01

    Safety factors for soil slopes are calculated using a non-linear Mohr envelope. The often used linear Mohr-Coulomb envelope tends to overestimate the safety as the material parameters are usually determined at much higher stress levels, than those present at slope failure. Experimental data...

  4. How does the increment of hetero-cyclic conjugated moieties affect electro-optical and charge transport properties of novel naphtha-difuran derivatives? A computational approach.

    Science.gov (United States)

    Chaudhry, Aijaz Rasool; Ahmed, R; Irfan, Ahmad; Muhammad, Shabbir; Shaari, A; Al-Sehemi, Abdullah G

    2014-12-01

    We have investigated computationally the effects of π-conjugation extension on naphtha[2,1-b:6,5-b'] difuran (DPNDF); where we increase the number of fused NDF (central core) and furan rings in the parent molecule. The molecular structures of all analogues have been optimized at the ground (S0) and first excited (S1) states using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), respectively. Then highest occupied molecular orbitals (HOMOs), the lowest unoccupied molecular orbitals (LUMOs), photophysical properties, adiabatic/vertical electron affinities (EAa)/(EAv), adiabatic/vertical ionization potentials (IPa)/(IPv), and hole/electron reorganization energies λh/λe have been investigated. The effect of NDF and furan rings on structural and electro-optical properties has also been studied. Our calculated reorganization energies of 1a, 1b, and 2c reveal them, materials with balanced hole/electron charge transport, whereas 2a and 2b are good hole-transport materials. By increasing the number of furan rings; the photostability was augmented in 2a, 2b, and 2c.

  5. Filtering Non-Linear Transfer Functions on Surfaces.

    Science.gov (United States)

    Heitz, Eric; Nowrouzezahrai, Derek; Poulin, Pierre; Neyret, Fabrice

    2014-07-01

    Applying non-linear transfer functions and look-up tables to procedural functions (such as noise), surface attributes, or even surface geometry are common strategies used to enhance visual detail. Their simplicity and ability to mimic a wide range of realistic appearances have led to their adoption in many rendering problems. As with any textured or geometric detail, proper filtering is needed to reduce aliasing when viewed across a range of distances, but accurate and efficient transfer function filtering remains an open problem for several reasons: transfer functions are complex and non-linear, especially when mapped through procedural noise and/or geometry-dependent functions, and the effects of perspective and masking further complicate the filtering over a pixel's footprint. We accurately solve this problem by computing and sampling from specialized filtering distributions on the fly, yielding very fast performance. We investigate the case where the transfer function to filter is a color map applied to (macroscale) surface textures (like noise), as well as color maps applied according to (microscale) geometric details. We introduce a novel representation of a (potentially modulated) color map's distribution over pixel footprints using Gaussian statistics and, in the more complex case of high-resolution color mapped microsurface details, our filtering is view- and light-dependent, and capable of correctly handling masking and occlusion effects. Our approach can be generalized to filter other physical-based rendering quantities. We propose an application to shading with irradiance environment maps over large terrains. Our framework is also compatible with the case of transfer functions used to warp surface geometry, as long as the transformations can be represented with Gaussian statistics, leading to proper view- and light-dependent filtering results. Our results match ground truth and our solution is well suited to real-time applications, requires only a few

  6. Non-linear model for compression tests on articular cartilage.

    Science.gov (United States)

    Grillo, Alfio; Guaily, Amr; Giverso, Chiara; Federico, Salvatore

    2015-07-01

    Hydrated soft tissues, such as articular cartilage, are often modeled as biphasic systems with individually incompressible solid and fluid phases, and biphasic models are employed to fit experimental data in order to determine the mechanical and hydraulic properties of the tissues. Two of the most common experimental setups are confined and unconfined compression. Analytical solutions exist for the unconfined case with the linear, isotropic, homogeneous model of articular cartilage, and for the confined case with the non-linear, isotropic, homogeneous model. The aim of this contribution is to provide an easily implementable numerical tool to determine a solution to the governing differential equations of (homogeneous and isotropic) unconfined and (inhomogeneous and isotropic) confined compression under large deformations. The large-deformation governing equations are reduced to equivalent diffusive equations, which are then solved by means of finite difference (FD) methods. The solution strategy proposed here could be used to generate benchmark tests for validating complex user-defined material models within finite element (FE) implementations, and for determining the tissue's mechanical and hydraulic properties from experimental data.

  7. New composite glass materials for non linear optical applications

    DEFF Research Database (Denmark)

    Menke, Y.; Ferraris, M.; Corbari, C.

    2004-01-01

    Metal nanocluster composite glasses were prepared via evaporation of a thin gold layer followed by diffusion. The effect of the deposition conditions, resulting in different evaporated gold thicknesses, and the influence of diffusion temperature and time have been studied. Resonance enhancement o...

  8. Preparation of Stable Photopatternable Polymeric Materials for Non- linear Optics

    Science.gov (United States)

    1993-05-01

    of limited versatility and is incompatible with the azobenzene and stilbene based chromo- phores.6’ 7 In addition it has proven extremely difficult...could not be achieved using dibutyltin dilaurate as a catalyst due to the occurrence of a trou- blesome transesterification side reaction of the...methacrylate moiety. Therefore, diazab- icyclo[2.2.2]-octane was used to catalyze the polymerization of monomer Q with iso- phorone diisocyanate. After

  9. Geometrically non linear analysis of functionally graded material ...

    African Journals Online (AJOL)

    user

    However, FGM plates under mechanical loading ..... vector is obtained from the tangent stiffness matrix, using the latest known solution and the process will ..... His areas of interests are Alternative fuels & CFD, Optimization techniques, soft.

  10. Fluid flow of incompressible viscous fluid through a non-linear elastic tube

    Energy Technology Data Exchange (ETDEWEB)

    Lazopoulos, A.; Tsangaris, S. [National Technical University of Athens, Fluids Section, School of Mechanical Engineering, Zografou, Athens (Greece)

    2008-11-15

    The study of viscous flow in tubes with deformable walls is of specific interest in industry and biomedical technology and in understanding various phenomena in medicine and biology (atherosclerosis, artery replacement by a graft, etc) as well. The present work describes numerically the behavior of a viscous incompressible fluid through a tube with a non-linear elastic membrane insertion. The membrane insertion in the solid tube is composed by non-linear elastic material, following Fung's (Biomechanics: mechanical properties of living tissue, 2nd edn. Springer, New York, 1993) type strain-energy density function. The fluid is described through a Navier-Stokes code coupled with a system of non linear equations, governing the interaction with the membrane deformation. The objective of this work is the study of the deformation of a non-linear elastic membrane insertion interacting with the fluid flow. The case of the linear elastic material of the membrane is also considered. These two cases are compared and the results are evaluated. The advantages of considering membrane nonlinear elastic material are well established. Finally, the case of an axisymmetric elastic tube with variable stiffness along the tube and membrane sections is studied, trying to substitute the solid tube with a membrane of high stiffness, exhibiting more realistic response. (orig.)

  11. A Method on Non-Linear Correction of Broadband LFMCW Signal Utilizing Its Relative Sweep Non-Linear Error

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a method on non-linear correction of broadband LFMCW signal utilizing its relativenonlinear error. The deriving procedure and the results simulated by a computer and tested by a practical system arealso introduced. The method has two obvious advantages compared with the previous methods: (1) Correction has norelation with delay time td and sweep bandwidth B; (2) The inherent non-linear error of VCO has no influence on thecorrection and its last results.

  12. Determination of the complex linear electro-optic coefficient of GaAs and InP

    Energy Technology Data Exchange (ETDEWEB)

    Pristovsek, Markus [Technische Universitaet Berlin, Institut fuer Festkoerperphysik, Hardenbergstrasse 36, 10623 Berlin (Germany)

    2010-08-15

    The complex linear electro-optic coefficient d{sub 41} was determined for the first time above the fundamental band gap of GaAs and InP by measuring the doping induced band bending of several oxidized samples in reflectance anisotropy spectroscopy. From the real and imaginary part of the change of the spectra for different carrier concentrations the spectral change of d{sub 41} was calculated. This is the first determination of the imaginary part Im(d{sub 41}). (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  13. Low voltage integrated optics electro-optical modulator applied to optical voltage transformer based on WLI technique

    Science.gov (United States)

    Santos, J. C.; Rubini, J.; Silva, L. P. C.; Caetano, R. E.

    2015-09-01

    The use of two electro-optical modulators linked in series, one for sensing and one for recovering signals, was formerly presented by some of the authors as a solution for interrogation of optical fiber sensor systems based on WLI method. A key feature required from such systems is that half-wave voltage (Vπ) of recovering modulator must be as small as possible. Aiming at meeting this requirement, in this paper it is presented the use of an unbalanced Michelson Interferometer implemented using an integrated optics component as recover interferometer in an optical voltage transformer intended for high voltage measurements.

  14. Electro-optical determination of the constant electric dipole of disperse particles by the method of crossed electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Voitylov, V.V.; Spartakov, A.A.; Tolstoi, N.A.; Trusov, A.A.; Boitsova, I.N. [St. Petersburg State Univ. (Russian Federation)

    1995-04-01

    An electro-optical method of crossed electric fields is proposed for determining constant dipole colloidal particles moments of colloidal particles. Fields of this type make it possible to study the motion of colloidal particles determined exclusively by their constant moments, which substantially improves the measurement accuracy of these moments. This is of particular importance for the investigation of colloidal particles with constant dipole moments less than or comparable to induced dipole moments. For a number of disperse systems, the constant dipole moments per unit area of particles are determined. It is shown that the values of these specific moments are close to each other.

  15. Compact silicon-on-insulator-based 2 × 2 Mach-Zehnder interferometer electro-optic switch with low crosstalk

    Institute of Scientific and Technical Information of China (English)

    Jiejiang Xing; Zhiyong Li; Peiji Zhou; Yuanhao Gong; Yude Yu; Manqing Tan; Jinzhong Yu

    2015-01-01

    We report a compact 2 × 2 Mach-Zehnder interferometer (MZI) electro-optic switch fabricated on a siliconon-insulator using standard complementary metal-oxide semiconductor (CMOS) processes.With a short modulation arm length of 200 μm,the crosstalk is reduced to-22 dB by the new modulation scheme of push-pull modulation with a pre-biased π/2 phase shift.The new modulation scheme can also work with a fast switching time of about 5.4 ns.

  16. Effects of chromophore concentration and film thickness on thermo-optic properties of electro-optic fluorinated polyimide films

    Institute of Scientific and Technical Information of China (English)

    Hongxiang Song; Chengxun Wu

    2007-01-01

    Electro-optic (EO) effect and thermo-optic (TO) effect are jointly considered on the basis of field-induced and temperature-affected perturbations of the operating point in waveguide components. TO coefficients of EO fluorinated polyimide films with side-chain azobenzene chromophore were measured by attenuatedtotal-reflection (ATR) technique at different temperatures with TE- and TM-polarized lights, respectively.It is found that the absolute values of TO coefficients increase with the increments of both chromophore concentration and film thickness, but the polarization dependence of TO coefficients increases with the increment of chromophore concentration and decreases with the increment of film thickness.

  17. Nanosecond Pulse Shaping with Fiber-Based Electro-Optical Modulators and a Double-Pass Tapered Amplifier

    CERN Document Server

    Rogers, Charles E

    2015-01-01

    We describe a system for generating frequency-chirped and amplitude-shaped pulses on time scales from sub-nanosecond to ten nanoseconds. The system starts with cw diode-laser light at 780 nm and utilizes fiber-based electro-optical phase and intensity modulators, driven by an arbitrary waveform generator, to generate the shaped pulses. These pulses are subsequently amplified to several hundred mW with a tapered amplifier in a delayed double-pass configuration. Frequency chirps up to 5 GHz in 2 ns and pulse widths as short as 0.15 ns have been realized.

  18. Design of Optical Tunable CNOT (XOR) and XNOR Logic Gates Based on 2D-Photonic Crystal Cavity Using Electro-Optic Effect

    CERN Document Server

    Abbasian, Karim; Sadeghi, Parvin

    2016-01-01

    We have proposed optical tunable CNOT (XOR) and XNOR logic gates using two-dimensional photonic crystal (2DPhC) cavities. Where, air rods with square lattice array have been embedded in Ag-Polymer substrate with refractive index of 1.59. In this work, we have enhanced speed of logic gates by applying two input signals with a phase dif?ference at the same wavelength for 2DPhC cavities. Where, we have adjusted the phases of input and control signals equal with {\\pi}/3 and zero, respectively. The response time of the structure and quality factor of the cavities are in the range of femtosecond and 2000, respectively. Then, we have used electro-optic property of the substrate material to change the cavities resonance wavelengths. By this means, we could design the logic gates and demonstrate a tunable range of 23nm for their operation wavelength. The quality factor and the response times of cavities remain constant in the tunable range of wavelength, approximately. The evaluated least ON to OFF logic-level contras...

  19. Non-linear homogenized and heterogeneous FE models for FRCM reinforced masonry walls in diagonal compression

    Science.gov (United States)

    Bertolesi, Elisa; Milani, Gabriele; Poggi, Carlo

    2016-12-01

    Two FE modeling techniques are presented and critically discussed for the non-linear analysis of tuff masonry panels reinforced with FRCM and subjected to standard diagonal compression tests. The specimens, tested at the University of Naples (Italy), are unreinforced and FRCM retrofitted walls. The extensive characterization of the constituent materials allowed adopting here very sophisticated numerical modeling techniques. In particular, here the results obtained by means of a micro-modeling strategy and homogenization approach are compared. The first modeling technique is a tridimensional heterogeneous micro-modeling where constituent materials (bricks, joints, reinforcing mortar and reinforcing grid) are modeled separately. The second approach is based on a two-step homogenization procedure, previously developed by the authors, where the elementary cell is discretized by means of three-noded plane stress elements and non-linear interfaces. The non-linear structural analyses are performed replacing the homogenized orthotropic continuum with a rigid element and non-linear spring assemblage (RBSM). All the simulations here presented are performed using the commercial software Abaqus. Pros and cons of the two approaches are herein discussed with reference to their reliability in reproducing global force-displacement curves and crack patterns, as well as to the rather different computational effort required by the two strategies.

  20. Massive Neutrinos and the Non-linear Matter Power Spectrum

    CERN Document Server

    Bird, Simeon; Haehnelt, Martin G

    2011-01-01

    We perform an extensive suite of N-body simulations of the matter power spectrum, incorporating massive neutrinos in the range M = 0.15-0.6 eV, probing the non-linear regime at scales k < 10 hMpc-1 at z < 3. We extend the widely used HALOFIT approximation (Smith et al. 2003) to account for the effect of massive neutrinos on the power spectrum. In the strongly non-linear regime HALOFIT systematically over-predicts the suppression due to the free-streaming of the neutrinos. The maximal discrepancy occurs at k \\sim 1hMpc-1, and is at the level of 10% of the total suppression. Most published constraints on neutrino masses based on HALOFIT are not affected, as they rely on data probing the matter power spectrum in the linear or mildly non-linear regime. However, predictions for future galaxy, Lyman-alpha forest and weak lensing surveys extending to more non-linear scales will benefit from the improved approximation to the non-linear matter power spectrum we provide. Our approximation reproduces the induced n...

  1. Analytical exact solution of the non-linear Schroedinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Alisson Xavier; Rocha Filho, Tarcisio Marciano da [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Fisica. Grupo de Fisica e Matematica

    2011-07-01

    Full text: In this work we present how to classify and obtain analytical solutions of the Schroedinger equation with a generic non-linearity in 1+1 dimensions. Our approach is based on the determination of Lie symmetry transformation mapping solutions into solutions, and non-classical symmetry transformations, mapping a given solution into itself. From these symmetries it is then possible to reduce the equation to a system of ordinary differential equations which can then be solved using standard methods. The generic non-linearity is handled by considering it as an additional unknown in the determining equations for the symmetry transformations. This results in an over-determined system of non-linear partial differential equations. Its solution can then be determined in some cases by reducing it to the so called involutive (triangular) form, and then solved. This reduction is very tedious and can only performed using a computer algebra system. Once the determining system is solved, we obtain the explicit form for the non-linearity admitting a Lie or non-classical symmetry. The analytical solutions are then derived by solving the reduced ordinary differential equations. The non-linear determining system for the non-classical symmetry transformations and Lie symmetry generators are obtaining using the computer algebra package SADE (symmetry analysis of differential equations), developed at our group. (author)

  2. The Importance of Non-Linearity on Turbulent Fluxes

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2007-01-01

    Two new non-linear models for the turbulent heat fluxes are derived and developed from the transport equation of the scalar passive flux. These models are called as non-linear eddy diffusivity and non-linear scalar flux. The structure of these models is compared with the exact solution which...... is derived from the Cayley-Hamilton theorem and contains a three term-basis plus a non-linear term due to scalar fluxes. In order to study the performance of the model itself, all other turbulent quantities are taken from a DNS channel flow data-base and thus the error source has been minimized. The results...... are compared with the DNS channel flow and good agreement is achieved. It has been shown that the non-linearity parts of the models are important to capture the true path of the streamwise scalar fluxes. It has also been shown that one of model constant should have negative sign rather than positive, which had...

  3. Static compressive strength prediction of open-hole structure based on non-linear shear behavior and micro-mechanics

    Science.gov (United States)

    Li, Wangnan; Cai, Hongneng; Li, Chao

    2014-11-01

    This paper deals with the characterization of the strength of the constituents of carbon fiber reinforced plastic laminate (CFRP), and a prediction of the static compressive strength of open-hole structure of polymer composites. The approach combined with non-linear analysis in macro-level and a linear elastic micromechanical failure analysis in microlevel (non-linear MMF) is proposed to improve the prediction accuracy. A face-centered cubic micromechanics model is constructed to analyze the stresses in fiber and matrix in microlevel. Non-interactive failure criteria are proposed to characterize the strength of fiber and matrix. The non-linear shear behavior of the laminate is studied experimentally, and a novel approach of cubic spline interpolation is used to capture significant non-linear shear behavior of laminate. The user-defined material subroutine UMAT for the non-linear share behavior is developed and combined in the mechanics analysis in the macro-level using the Abaqus Python codes. The failure mechanism and static strength of open-hole compressive (OHC) structure of polymer composites is studied based on non-linear MMF. The UTS50/E51 CFRP is used to demonstrate the application of theory of non-linear MMF.

  4. Manufacture tolerance analysis and control for a polymer on-silicon Mach-Zehnder-interferometer-based electro-optic switch

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chuan-tao; MA Chun-sheng; YAN Xin; CUI Zhan-chen; ZHANG Da-ming

    2011-01-01

    To enhance the electro-optic (EO) modulation efficiency and realize the impedance-matching, a polymer-on-silicon multi mode interference (MMI) Mach-Zehnder interferometer (MZI) -based electro-optic (EO) switch is designed and optimized.Under the central operation wavelength of 1550 nm, the driving voltages of the designed switch are O and ±1.375 V,respectively, with a short active region length of 5 mm, and the characteristic impedance of the electrode is about 49.6 Ω.The manufacture tolerance is analyzed for instructing the device fabrication. The results show that to realize ideal switching function, high fabrication accuracy on the buffer thickness, core thickness, electrode width and MMI wavegnide width is extremely required, and a small voltage drift of-0.03-0.05 V is also expected for reducing the crosstalk to less than -30 dB.The allowed 3 dB bandwidth is 60 nm, and within this spectrum range, the insertion loss and crosstalk are less than 6.71 dB and -30 dB, respectively.

  5. Electro-optic Properties of DR1 Doped SiO_2 Organic/inorganic Guest-host Films

    Institute of Scientific and Technical Information of China (English)

    LIU Shao-lin; YANG Han; JIN Ru-long; YAN Zhao-xu; YI Mao-bin

    2009-01-01

    We made a comprehensive investigation on the electro-optic(EO) properties of hybrid sol-gel silica film doped with Dispersed Red 1 dye(DRl/SiO_2). An important finding is that the dipoles which don't orient along the direction of corona poling field in the films can be instantaneously poled by alternate modulation electrical field. This instant poling effect results in the EO coefficients dependent on the frequency and intensity of alternate modulation electric field, and some experiments have proved it. We also investigated the electro-optic coefficients and thickness of films at different stir temperatures(T_s) of start solution and at different number densities of DR1. Experimentally the DR1 number density was optimized to an order of 10~(21)/cm~3 and a large EO coefficient of γ_(33)= 37 pm/V for DR1/SiO_2 film was measured by simple reflection technique at 1 kHz frequencies of modulation electric field. These findings may benefit the practical application of DR1/SiO_2 films in the field of EO modulator and EO probing.

  6. Effects of carbon nanotubes on liquid crystal order parameter and Freedericksz transition in electro-optic cells

    Science.gov (United States)

    Georgiev, Georgi; Gombos, Erin; McIntyre, Michael; Mattera, Michael; Gati, Peter; Cabrera, Yaniel; Cebe, Peggy

    2010-03-01

    We studied the effects of multiwalled carbon nanotubes (MWCTs) at low concentrations (0.01 wt %) on the Freedericksz transition of a 4-Cyano-4'-pentylbipenyl (5CB) liquid crystal using transmission ellipsometry. In addition, we calibrated the altitudinal angle of CNTs as a function of the electric field and directed the azimuthal angle which gave us complete control of the 3D orientation of the CNTs. Our results show that in the presence of CNTs the voltage and width for the Freedericksz transition are reduced by a factor of 1.8 as compared to the control electro-optic cell without CNTs. The shift in transition voltage correlates with increase in order parameter of the electro-optic cell as measured by our polarized UV/Vis absorption spectroscopy results. Research supported by: Assumption College Faculty Development Grant, funding for students' stipends, instrumentation and supplies, the NSF Polymers Program of the DME, grant (DMR-0602473) and NASA grant (NAG8-1167).

  7. Electro-optic comb based real time ultra-high sensitivity phase noise measurement system for high frequency microwaves.

    Science.gov (United States)

    Kuse, N; Fermann, M E

    2017-06-06

    Recent progress in ultra low phase noise microwave generation indispensably depends on ultra low phase noise characterization systems. However, achieving high sensitivity currently relies on time consuming averaging via cross correlation, which sometimes even underestimates phase noise because of residual correlations. Moreover, extending high sensitivity phase noise measurements to microwaves beyond 10 GHz is very difficult because of the lack of suitable high frequency microwave components. In this work, we introduce a delayed self-heterodyne method in conjunction with sensitivity enhancement via the use of higher order comb modes from an electro-optic comb for ultra-high sensitivity phase noise measurements. The method obviates the need for any high frequency RF components and has a frequency measurement range limited only by the bandwidth (100 GHz) of current electro-optic modulators. The estimated noise floor is as low as -133 dBc/Hz, -155 dBc/Hz, -170 dBc/Hz and -171 dBc/Hz without cross correlation at 1 kHz, 10 kHz, 100 kHz and 1 MHz Fourier offset frequency for a 10 GHz carrier, respectively. Moreover, since no cross correlation is necessary, RF oscillator phase noise can be directly suppressed via feedback up to 100 kHz frequency offset.

  8. Direct electro-optical pumping for hybrid CdSe nanocrystal/III-nitride based nano-light-emitting diodes

    Science.gov (United States)

    Mikulics, M.; Arango, Y. C.; Winden, A.; Adam, R.; Hardtdegen, A.; Grützmacher, D.; Plinski, E.; Gregušová, D.; Novák, J.; Kordoš, P.; Moonshiram, A.; Marso, M.; Sofer, Z.; Lüth, H.; Hardtdegen, H.

    2016-02-01

    We propose a device concept for a hybrid nanocrystal/III-nitride based nano-LED. Our approach is based on the direct electro-optical pumping of nanocrystals (secondary excitation) by electrically driven InGaN/GaN nano-LEDs as the primary excitation source. To this end, a universal hybrid optoelectronic platform was developed for a large range of optically active nano- and mesoscopic structures. The advantage of the approach is that the emission of the nanocrystals can be electrically induced without the need of contacting them. The proof of principal was demonstrated for the electro-optical pumping of CdSe nanocrystals. The nano-LEDs with a diameter of 100 nm exhibit a very low current of ˜8 nA at 5 V bias which is several orders of magnitude smaller than for those conventionally used. The leakage currents in the device layout were typically in the range of 8 pA to 20 pA/cm2 at 5 V bias. The photon-photon down conversion efficiency was determined to be 27%. Microphotoluminescence and microelectroluminescence characterization demonstrate the potential for future optoelectronics and highly secure "green" information technology applications.

  9. Research on Airborne Electro-Optical Tracking and Sighting System Based on Fuzzy PID and H∞ Control

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance, and its control system consists of stabilizing and tracking components. Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition, and its robustness should be very good; tracking control is applied to compensate tracking error of angular position. A mathematical model is established by taking the control of yaw loop as example. H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter. A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control. Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good, especially when the model parameters change and the multi-disturbance exists, the system capability has little fall, but this system still can effectively track a target.

  10. High-Contrast Electro-Optic Modulation of a Photonic Crystal Nanocavity by Electrical Gating of Graphene

    CERN Document Server

    Gan, Xuetao; Gao, Yuanda; Mak, Kin Fai; Yao, Xinwen; Li, Luozhou; Szep, Attila; Walker, Dennis; Hone, James; Heinz, Tony F; Englund, Dirk

    2012-01-01

    We demonstrate a high-contrast electro-optic modulation of a photonic crystal nanocavity integrated with an electrically gated monolayer graphene. A high quality (Q) factor air-slot nanocavity design is employed for high overlap between the optical field and graphene sheet. Tuning of graphene's Fermi level up to 0.8 eV enables efficient control of its complex dielectric constant, which allows modulation of the cavity reflection in excess of 10 dB for a swing voltage of only 1.5 V. We also observe a controllable resonance wavelength shift close to 2 nm around a wavelength of 1570 nm and a Q factor modulation in excess of three. These observations allow cavity-enhanced measurements of the graphene complex dielectric constant under different chemical potentials, in agreement with a theoretical model of the graphene dielectric constant under gating. This graphene-based nanocavity modulation demonstrates the feasibility of high-contrast, low-power frequency-selective electro-optic nanocavity modulators in graphene...

  11. A Comparison between Two Heterodyne Light Sources Using Different Electro-Optic Modulators for Optical Temperature Measurements at Visible Wavelengths

    Directory of Open Access Journals (Sweden)

    Ruey-Ching Twu

    2010-10-01

    Full Text Available In this paper we have successfully demonstrated a z-propagating Zn-indiffused lithium niobate electro-optic modulator used for optical heterodyne interferometry. Compared to a commercial buck-type electro-optic modulator, the proposed waveguide-type modulator has a lower driving voltage and smaller phase variation while measuring visible wavelengths of 532 nm and 632.8 nm. We also demonstrate an optical temperature measurement system using a homemade modulator. The results show that the measurement sensitivities are almost the same values of 25 deg/°C for both the homemade and the buck-type modulators for a sensing light with a wavelength of 632.8 nm. Because photorefractive impacts are essential in the buck-type modulator at a wavelength of 532 nm, it is difficult to obtain reliable phase measurements, whereas the stable phase operation of the homemade one allows the measurement sensitivity to be improved up to 30 deg/°C with the best measurement resolution at about 0.07 °C for 532 nm.

  12. Photo-stimulated electro-optic response of liquid-crystalline system with trans-cis photo-isomerizable agent

    Science.gov (United States)

    Hadjichristov, G. B.; Marinov, Y. G.; Yelamaggad, C. V.

    2014-12-01

    A rather strong photo-stimulated enhancement of photo-induced bend flexoelectric effect based on trans-cis photoisomerization of azo bond was found in a guest-host system formed from the nematic liquid crystal (LC) N-(4-methoxybenzylidene)-4-butylaniline (MBBA) as a host, and the azobenzene LC 4-hexyloxybenzoloxy-4'-cyanoazobenzene, as a guest photoactive agent at 1 wt.% concentration. Upon application of electric field, thin homeotropic layers of thickness 100 pm containing this photo-sensitized LC mixture were investigated as subjected to a relatively weak illumination with UV light (λ = 375 nm, from narrow-band light-emitting diode, LED). The stimulation of the photoactive electro-optic response of azobenzene-doped MBBA (owing to enhanced photo-induced bend flexoelectric effect driven by the photo-isomerizable dopants) was achieved by pre-resonant excitation of the photoactive agent. The degree of the effect measured is of potential interest for thin-film photoactive electro-optic applications. The UV light-induced effect in azobenzene-doped MBBA was reversible; the back (relaxation) process was stimulated by light in the blue from a LED with broadband spectrum centered at 455 nm.

  13. Controlling ultrafast currents by the non-linear photogalvanic effect

    CERN Document Server

    Wachter, Georg; Lemell, Christoph; Tong, Xiao-Min; Yabana, Kazuhiro; Burgdörfer, Joachim

    2015-01-01

    We theoretically investigate the effect of broken inversion symmetry on the generation and control of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on time-dependent density functional theory predict ultrafast DC currents that can be viewed as a non-linear photogalvanic effect. Most surprisingly, the direction of the current undergoes a sudden reversal above a critical threshold value of laser intensity I_c ~ 3.8*10^13 W/cm2. We trace this switching to the transition from non-linear polarization currents to the tunneling excitation regime. We demonstrate control of the ultrafast currents by the time delay between two laser pulses. We find the ultrafast current control by the non-linear photogalvanic effect to be remarkably robust and insensitive to laser-pulse shape and carrier-envelope phase.

  14. An algorithm for earthwork allocation considering non-linear factors

    Institute of Scientific and Technical Information of China (English)

    WANG Ren-chao; LIU Jin-fei

    2008-01-01

    For solving the optimization model of earthwork allocation considering non-linear factors, a hybrid al-gorithm combined with the ant algorithm (AA) and particle swarm optimization (PSO) is proposed in this pa-per. Then the proposed method and the LP method are used respectively in solving a linear allocation model of a high rockfill dam project. Results obtained by these two methods are compared each other. It can be conclu-ded that the solution got by the proposed method is extremely approximate to the analytic solution of LP method. The superiority of the proposed method over the LP method in solving a non-linear allocation model is illustrated by a non-linear case. Moreover, further researches on improvement of the algorithm and the allocation model are addressed.

  15. Non-linear behaviour of large-area avalanche photodiodes

    CERN Document Server

    Fernandes, L M P; Monteiro, C M B; Santos, J M; Morgado, R E

    2002-01-01

    The characterisation of photodiodes used as photosensors requires a determination of the number of electron-hole pairs produced by scintillation light. One method involves comparing signals produced by X-ray absorptions occurring directly in the avalanche photodiode with the light signals. When the light is derived from light-emitting diodes in the 400-600 nm range, significant non-linear behaviour is reported. In the present work, we extend the study of the linear behaviour to large-area avalanche photodiodes, of Advanced Photonix, used as photosensors of the vacuum ultraviolet (VUV) scintillation light produced by argon (128 nm) and xenon (173 nm). We observed greater non-linearities in the avalanche photodiodes for the VUV scintillation light than reported previously for visible light, but considerably less than the non-linearities observed in other commercially available avalanche photodiodes.

  16. Pattern formation due to non-linear vortex diffusion

    Science.gov (United States)

    Wijngaarden, Rinke J.; Surdeanu, R.; Huijbregtse, J. M.; Rector, J. H.; Dam, B.; Einfeld, J.; Wördenweber, R.; Griessen, R.

    Penetration of magnetic flux in YBa 2Cu 3O 7 superconducting thin films in an external magnetic field is visualized using a magneto-optic technique. A variety of flux patterns due to non-linear vortex diffusion is observed: (1) Roughening of the flux front with scaling exponents identical to those observed in burning paper including two distinct regimes where respectively spatial disorder and temporal disorder dominate. In the latter regime Kardar-Parisi-Zhang behavior is found. (2) Fractal penetration of flux with Hausdorff dimension depending on the critical current anisotropy. (3) Penetration as ‘flux-rivers’. (4) The occurrence of commensurate and incommensurate channels in films with anti-dots as predicted in numerical simulations by Reichhardt, Olson and Nori. It is shown that most of the observed behavior is related to the non-linear diffusion of vortices by comparison with simulations of the non-linear diffusion equation appropriate for vortices.

  17. Non-linear system identification in flow-induced vibration

    Energy Technology Data Exchange (ETDEWEB)

    Spanos, P.D.; Zeldin, B.A. [Rice Univ., Houston, TX (United States); Lu, R. [Hudson Engineering Corp., Houston, TX (United States)

    1996-12-31

    The paper introduces a method of identification of non-linear systems encountered in marine engineering applications. The non-linearity is accounted for by a combination of linear subsystems and known zero-memory non-linear transformations; an equivalent linear multi-input-single-output (MISO) system is developed for the identification problem. The unknown transfer functions of the MISO system are identified by assembling a system of linear equations in the frequency domain. This system is solved by performing the Cholesky decomposition of a related matrix. It is shown that the proposed identification method can be interpreted as a {open_quotes}Gram-Schmidt{close_quotes} type of orthogonal decomposition of the input-output quantities of the equivalent MISO system. A numerical example involving the identification of unknown parameters of flow (ocean wave) induced forces on offshore structures elucidates the applicability of the proposed method.

  18. Non-linear Growth Models in Mplus and SAS.

    Science.gov (United States)

    Grimm, Kevin J; Ram, Nilam

    2009-10-01

    Non-linear growth curves or growth curves that follow a specified non-linear function in time enable researchers to model complex developmental patterns with parameters that are easily interpretable. In this paper we describe how a variety of sigmoid curves can be fit using the Mplus structural modeling program and the non-linear mixed-effects modeling procedure NLMIXED in SAS. Using longitudinal achievement data collected as part of a study examining the effects of preschool instruction on academic gain we illustrate the procedures for fitting growth models of logistic, Gompertz, and Richards functions. Brief notes regarding the practical benefits, limitations, and choices faced in the fitting and estimation of such models are included.

  19. Change-Of-Bases Abstractions for Non-Linear Systems

    CERN Document Server

    Sankaranarayanan, Sriram

    2012-01-01

    We present abstraction techniques that transform a given non-linear dynamical system into a linear system or an algebraic system described by polynomials of bounded degree, such that, invariant properties of the resulting abstraction can be used to infer invariants for the original system. The abstraction techniques rely on a change-of-basis transformation that associates each state variable of the abstract system with a function involving the state variables of the original system. We present conditions under which a given change of basis transformation for a non-linear system can define an abstraction. Furthermore, the techniques developed here apply to continuous systems defined by Ordinary Differential Equations (ODEs), discrete systems defined by transition systems and hybrid systems that combine continuous as well as discrete subsystems. The techniques presented here allow us to discover, given a non-linear system, if a change of bases transformation involving degree-bounded polynomials yielding an alge...

  20. Selected Aspects Of Modelling Of Non-Linear Behaviour Of Concrete During Tensile Test Using Multiplas Library

    Directory of Open Access Journals (Sweden)

    Hokeš Filip

    2015-12-01

    Full Text Available The subject of this paper is to describe some of the aspects manifesting in the use of the elastoplastic material model library multiPlas, which was developed to support non-linear computations in the ANSYS system. The text focuses on the analysis of numerical simulations of a virtual tension test in several case studies, thereby the text endeavours to describe the problems connected with modelling non-linear behaviour of concrete in a tensile area.