WorldWideScience

Sample records for internal photon emitters

  1. Nanodiamond Emitters of Single Photons

    Directory of Open Access Journals (Sweden)

    Vlasov I.I.

    2015-01-01

    Full Text Available Luminescence properties of single color centers were studied in nanodiamonds of different origin. It was found that single photon emitters could be realized even in molecularsized diamond (less than 2 nm capable of housing stable luminescent center “silicon-vacancy.” First results on incorporation of single-photon emitters based on luminescent nanodiamonds in plasmonic nanoantennas to enhance the photon count rate and directionality, diminish the fluorescence decay time, and provide polarization selectivity are presented.

  2. Emitters of N-photon bundles.

    Science.gov (United States)

    Muñoz, C Sánchez; Del Valle, E; Tudela, A González; Müller, K; Lichtmannecker, S; Kaniber, M; Tejedor, C; Finley, J J; Laussy, F P

    2014-07-01

    Controlling the ouput of a light emitter is one of the basic tasks of photonics, with landmarks such as the laser and single-photon sources. The development of quantum applications makes it increasingly important to diversify the available quantum sources. Here, we propose a cavity QED scheme to realize emitters that release their energy in groups, or "bundles" of N photons, for integer N. Close to 100% of two-photon emission and 90% of three-photon emission is shown to be within reach of state of the art samples. The emission can be tuned with system parameters so that the device behaves as a laser or as a N-photon gun. The theoretical formalism to characterize such emitters is developed, with the bundle statistics arising as an extension of the fundamental correlation functions of quantum optics. These emitters will be useful for quantum information processing and for medical applications.

  3. Solid-state single-photon emitters

    Science.gov (United States)

    Aharonovich, Igor; Englund, Dirk; Toth, Milos

    2016-10-01

    Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

  4. Two-photon interference from two blinking quantum emitters

    Science.gov (United States)

    Jöns, Klaus D.; Stensson, Katarina; Reindl, Marcus; Swillo, Marcin; Huo, Yongheng; Zwiller, Val; Rastelli, Armando; Trotta, Rinaldo; Björk, Gunnar

    2017-08-01

    We investigate the effect of blinking on the two-photon interference measurement from two independent quantum emitters. We find that blinking significantly alters the statistics in the Hong-Ou-Mandel second-order intensity correlation function g(2 )(τ ) and the outcome of two-photon interference measurements performed with independent quantum emitters. We theoretically demonstrate that the presence of blinking can be experimentally recognized by a deviation from the gD(2 )(0 ) =0.5 value when distinguishable photons from two emitters impinge on a beam splitter. Our findings explain the significant differences between linear losses and blinking for correlation measurements between independent sources and are experimentally verified using a parametric down-conversion photon-pair source. We show that blinking imposes a mandatory cross-check measurement to correctly estimate the degree of indistinguishability of photons emitted by independent quantum emitters.

  5. Photon pair source via two coupling single quantum emitters

    Institute of Scientific and Technical Information of China (English)

    彭勇刚; 郑雨军

    2015-01-01

    We study the two coupling two-level single molecules driven by an external field as a photon pair source. The proba-bility of emitting two photons, P2, is employed to describe the photon pair source quality in a short time, and the correlation coefficient RAB is employed to describe the photon pair source quality in a long time limit. The results demonstrate that the coupling single quantum emitters can be considered as a stable photon pair source.

  6. Efficient low-temperature thermophotovoltaic emitters from metallic photonic crystals.

    Science.gov (United States)

    Nagpal, Prashant; Han, Sang Eon; Stein, Andreas; Norris, David J

    2008-10-01

    We examine the use of metallic photonic crystals as thermophotovoltaic emitters. We coat silica woodpile structures, created using direct laser writing, with tungsten or molybdenum. Optical reflectivity and thermal emission measurements near 650 degrees C demonstrate that the resulting structures should provide efficient emitters at relatively low temperatures. When matched to InGaAsSb photocells, our structures should generate over ten times more power than solid emitters while having an optical-to-electrical conversion efficiency above 32%. At such low temperatures, these emitters have promise not only in solar energy but also in harnessing geothermal and industrial waste heat.

  7. Hybrid genetic optimization for design of photonic crystal emitters

    Science.gov (United States)

    Rammohan, R. R.; Farfan, B. G.; Su, M. F.; El-Kady, I.; Reda Taha, M. M.

    2010-09-01

    A unique hybrid-optimization technique is proposed, based on genetic algorithms (GA) and gradient descent (GD) methods, for the smart design of photonic crystal (PhC) emitters. The photonic simulation is described and the granularity of photonic crystal dimensions is considered. An innovative sliding-window method for performing local heuristic search is demonstrated. Finally, the application of the proposed method on two case studies for the design of a multi-pixel photonic crystal emitter and the design of thermal emitter in thermal photovoltaic is demonstrated. Discussion in the report includes the ability of the optimal PhC structures designed using the proposed method, to produce unprecedented high emission efficiencies of 54.5% in a significantly long wavelength region and 84.9% at significantly short wavelength region.

  8. Very bright, near-infrared single photon emitters in diamond

    Directory of Open Access Journals (Sweden)

    D. W. M. Lau

    2013-09-01

    Full Text Available We demonstrate activation of bright diamond single photon emitters in the near infrared range by thermal annealing alone, i.e., without ion implantation. The activation is crucially dependent on the annealing ambient. The activation of the single photon emitters is only observed when the sample is annealed in forming gas (4% H2 in Ar above temperatures of 1000 °C. By contrast, no emitters are activated by annealing in vacuum, oxygen, argon or deuterium. The emitters activated by annealing in forming gas exhibit very bright emission in the 730-760 nm wavelength range and have linewidths of ∼1.5-2.5 nm at room temperature.

  9. Localization of Narrowband Single Photon Emitters in Nanodiamonds.

    Science.gov (United States)

    Bray, Kerem; Sandstrom, Russell; Elbadawi, Christopher; Fischer, Martin; Schreck, Matthias; Shimoni, Olga; Lobo, Charlene; Toth, Milos; Aharonovich, Igor

    2016-03-23

    Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bioimaging. However, current understanding of the origin of these emitters is extremely limited. In this work, we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond and are directly relevant to fabrication of novel quantum optics devices and sensors.

  10. Localization of narrowband single photon emitters in nanodiamonds

    CERN Document Server

    Bray, Kerem; Elbadawi, Christopher; Fischer, Martin; Schreck, Matthias; Shimoni, Olga; Lobo, Charlene; Toth, Milos; Aharonovich, Igor

    2016-01-01

    Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bio-imaging. However, current understanding of the origin of these emitters is extremely limited. In this work we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond, and are directly relevant to fabrication of novel quantum optics devices and sensors.

  11. High-efficiency photonic crystal narrowband thermal emitters

    Science.gov (United States)

    Farfan, G. B.; Su, M. F.; Reda Taha, M. M.; El-Kady, I.

    2010-02-01

    Photonic crystals (PhC) are artificial structures fabricated with a periodicity in the dielectric function. This periodic electromagnetic potential results in creation of energy bandgaps where photon propagation is prohibited. PhC structures have promising use in thermal applications if optimized to operate at specific thermal emission spectrum. Here, novel utilization of optimized PhC's in thermal applications is presented. We demonstrate through numerical simulation the modification of the thermal emission spectrum by a metallic photonic crystal (PhC) to create high-efficiency multispectral thermal emitters. These emitters funnel radiation from a broad emission spectrum associated with a Plancklike distribution into a prescribed narrow emission band. A detailed quantitative evaluation of the spectral and power efficiencies of a PhC thermal emitter and its portability across infrared (IR) spectral bands are provided. We show an optimized tungsten PhC with a predominant narrow-band emission profile with an emitter efficiency that is more than double that of an ideal blackbody and ~65-75% more power-efficiency across the IR spectrum. We also report on using optimal three-dimensional Lincoln log photonic crystal (LL-PhC) emitters for thermophotovoltaic (TPV) generation as opposed to using a passive filtering approach to truncate the broadband thermal source emission to match the bandgap of a photovoltaic (PV) cell. The emitter performance is optimized for the 1-2μm PV band using different PhC materials, specifically copper, silver and gold. The use of the proposed PhC in TPV devices can produce significant energy savings not reported before. The optimal design of the PhC geometry is obtained by implementing a variety of optimization methods integrated with artificial intelligence (AI) algorithms.

  12. 99% efficiency in collecting photons from a single emitter

    CERN Document Server

    Chen, Xue-Wen; Sandoghdar, Vahid

    2011-01-01

    In Nature Photonics 5, 166 (2011), we reported on a planar dielectric antenna that achieved 96% efficiency in collecting the photons emitted by a single molecule. In that work the transition dipole moment of the molecule was set perpendicular to the antenna plane. Here, we present an extension of that scheme that reaches collection efficiencies beyond 99% for emitters with arbitrarily oriented dipole moments. Our work opens important doors in a wide range of contexts including quantum optics, quantum metrology, nano-analytics, and biophysics. In particular, we provide antenna parameters to realize ultrabright single-photon sources in high-index materials such as semiconductor quantum dots and color centers in diamond, as well as sensitive detection of single molecules in nanofluidic devices.

  13. Internal emitter limits for iodine, radium and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Schlenker, R.A.

    1984-08-15

    This paper identifies some of the issues which arise in the consideration of the derivation of new limits on exposure to internal emitters. Basic and secondary radiation protection limits are discussed. Terms are defined and applied to the limitation of risk from stochastic effects. Non-stochastic data for specific internal emitters (/sup 131/I and the radium isotopes) are presented. Emphasis is placed on the quantitative aspects of the limit setting problem. 65 references, 2 figures, 12 tables.

  14. Coherent single-photon absorption by single emitters coupled to one-dimensional nanophotonic waveguides

    DEFF Research Database (Denmark)

    Chen, Yuntian; Wubs, Martijn; Mørk, Jesper;

    2011-01-01

    We study the dynamics of single-photon absorption by a single emitter coupled to a one-dimensional waveguide that simultaneously provides channels for spontaneous emission (SE) decay and a channel for the input photon. We have developed a time-dependent theory that allows us to specify any input ...... can be improved by a further 4% by engineering the dispersion. Efficient single-photon absorption by a single emitter has potential applications in quantum communication and quantum computation....

  15. Radiation doses and risks from internal emitters

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, John [Health Protection Agency, Radiation Protection Division, CRCE, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Day, Philip [School of Chemistry, University of Manchester, Manchester M13 9PL (United Kingdom)], E-mail: john.harrison@hpa.org.uk, E-mail: philip.day@manchester.ac.uk

    2008-06-01

    This review updates material prepared for the UK Government Committee Examining Radiation Risks from Internal Emitters (CERRIE) and also refers to the new recommendations of the International Commission on Radiological Protection (ICRP) and other recent developments. Two conclusions from CERRIE were that ICRP should clarify and elaborate its advice on the use of its dose quantities, equivalent and effective dose, and that more attention should be paid to uncertainties in dose and risk estimates and their implications. The new ICRP recommendations provide explanations of the calculation and intended purpose of the protection quantities, but further advice on their use would be helpful. The new recommendations refer to the importance of understanding uncertainties in estimates of dose and risk, although methods for doing this are not suggested. Dose coefficients (Sv per Bq intake) for the inhalation or ingestion of radionuclides are published as reference values without uncertainty. The primary purpose of equivalent and effective dose is to enable the summation of doses from different radionuclides and from external sources for comparison with dose limits, constraints and reference levels that relate to stochastic risks of whole-body radiation exposure. Doses are calculated using defined biokinetic and dosimetric models, including reference anatomical data for the organs and tissues of the human body. Radiation weighting factors are used to adjust for the different effectiveness of different radiation types, per unit absorbed dose (Gy), in causing stochastic effects at low doses and dose rates. Tissue weighting factors are used to take account of the contribution of individual organs and tissues to overall detriment from cancer and hereditary effects, providing a simple set of rounded values chosen on the basis of age- and sex-averaged values of relative detriment. While the definition of absorbed dose has the scientific rigour required of a basic physical quantity

  16. In-plane emission of indistinguishable photons generated by an integrated quantum emitter

    CERN Document Server

    Kalliakos, Sokratis; Schwagmann, Andre; Bennett, Anthony J; Ward, Martin B; Ellis, David J P; Skiba-Szymanska, Joanna; Farrer, Ian; Griffiths, Jonathan P; Jones, Geb A C; Ritchie, David A; Shields, Andrew J

    2014-01-01

    We demonstrate the emission of indistinguishable photons along a semiconductor chip originating from carrier recombination in an InAs quantum dot. The emitter is integrated in the waveguiding region of a photonic crystal structure, allowing for on-chip light propagation. We perform a Hong-Ou-Mandel-type of experiment with photons collected from the exit of the waveguide and we observe two-photon interference under continuous wave excitation. Our results pave the way for the integration of quantum emitters in advanced photonic quantum circuits.

  17. Reconstruction of the environmental correlation function from single emitter photon statistics: a non-Markovian approach

    CERN Document Server

    Shikerman, Faina; Pe'er, Avi

    2012-01-01

    We consider the two-level system approximation of a single emitter driven by a continuous laser pump and simultaneously coupled to the electromagnetic vacuum and to a thermal reservoir beyond the Markovian approximation. We discuss the connection between a rigorous microscopic theory and the phenomenological spectral diffusion approach, used to model the interaction of the emitter with the thermal bath, and obtained analytic expressions relating the thermal correlation function to the single emitter photon statistics.

  18. Two-photon interference from independent cavity-coupled emitters on-a-chip

    CERN Document Server

    Kim, Je-Hyung; Leavitt, Richard P; Waks, Edo

    2016-01-01

    Interactions between solid-state quantum emitters and cavities are important for a broad range of applications in quantum communication, linear optical quantum computing, nonlinear photonics, and photonic quantum simulation. These applications often require combining many devices on a single chip with identical emission wavelengths in order to generate two-photon interference, the primary mechanism for achieving effective photon-photon interactions. Such integration remains extremely challenging due to inhomogeneous broadening and fabrication errors that randomize the resonant frequencies of both the emitters and cavities. In this letter we demonstrate two-photon interference from independent cavity-coupled emitters on the same chip, providing a potential solution to this long-standing problem. We overcome spectral mismatch between different cavities due to fabrication errors by depositing and locally evaporating a thin layer of condensed nitrogen. We integrate optical heaters to tune individual dots within e...

  19. Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings

    CERN Document Server

    Gonzalez-Ballestero, C; Vidal, F J Garcia; Gonzalez-Tudela, A

    2016-01-01

    We demonstrate the possibility of designing efficient, non reciprocal few-photon devices by exploiting the chiral coupling between two waveguide modes and a single quantum emitter. We show how this system can induce non-reciprocal photon transport at the single-photon level and act as an optical diode. Afterwards, we also show how the same system shows a transistor-like behaviour for a two-photon input. The efficiency in both cases is shown to be large for feasible experimental implementations. Our results illustrate the potential of chiral waveguide-emitter couplings for applications in quantum circuitry.

  20. Wiring up pre-characterized single-photon emitters by laser lithography

    Science.gov (United States)

    Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

    2016-08-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

  1. Non-blinking single-photon emitters in silica

    NARCIS (Netherlands)

    Rabouw, F.T.; Cogan, N.M.B.; Berends, Anne; van der Stam, Ward; Vanmaekelbergh, Daniel|info:eu-repo/dai/nl/304829137; Koenderink, A.F.; Kraus, T.D.; de Mello-Donega, Celso|info:eu-repo/dai/nl/125593899

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at

  2. Photon scattering by a three-level emitter in a one-dimensional waveguide

    CERN Document Server

    Witthaut, D

    2010-01-01

    We discuss the scattering of photons from a three-level emitter in a one-dimensional waveguide, where the transport is governed by the interference of spontaneously emitted and directly transmitted waves. The scattering problem is solved in closed form for different level structures. Several possible applications are discussed: The state of the emitter can be switched deterministically by Raman scattering, thus enabling applications in quantum computing such as a single photon transistor. An array of emitters gives rise to a photonic band gap structure, which can be tuned by a classical driving laser. A disordered array leads to Anderson localization of photons, where the localization length can again be controlled by an external driving.

  3. Nonclassical light from a large number of independent single-photon emitters

    CERN Document Server

    Lachman, Lukáš; Filip, Radim

    2016-01-01

    Nonclassical quantum effects gradually reach domains of physics of large systems previously considered as purely classical. We derive a hierarchy of operational criteria suitable for a reliable detection of nonclassicality of light from an arbitrarily large ensemble of independent single-photon emitters. We show, that such large ensemble can always emit nonclassical light without any phase reference and under realistic experimental conditions including incoherent background noise. The nonclassical light from the large ensemble of the emitters can be witnessed much better than light coming from a single or a few emitters.

  4. Strong nonlinearity-induced correlations for counterpropagating photons scattering on a two-level emitter

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara; Mørk, Jesper

    2015-01-01

    We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could...... be quantified via a reduction in coincidence clicks in a Hong–Ou–Mandel measurement setup, analogous to a linear beam splitter. Changes to the spectra and phase of the scattered photons, however, would lead to reduced interference with other photons when implemented in a larger optical circuit. We introduce...... suitable fidelity measures which account for these changes and find that high values can still be achieved even when accounting for all properties of the scattered photonic state....

  5. Biologic data, models, and dosimetric methods for internal emitters

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D.A.

    1990-01-01

    The absorbed radiation dose from internal emitters has been and will remain a pivotal factor in assessing risk and therapeutic utility in selecting radiopharmaceuticals for diagnosis and treatment. Although direct measurements of absorbed dose and dose distributions in vivo have been and will continue to be made in limited situations, the measurement of the biodistribution and clearance of radiopharmaceuticals in human subjects and the use of this data is likely to remain the primary means to approach the calculation and estimation of absorbed dose from internal emitters over the next decade. Since several approximations are used in these schema to calculate dose, attention must be given to inspecting and improving the application of this dosimetric method as better techniques are developed to assay body activity and as more experience is gained in applying these schema to calculating absorbed dose. Discussion of the need for considering small scale dosimetry to calculate absorbed dose at the cellular level will be presented in this paper. Other topics include dose estimates for internal emitters, biologic data mathematical models and dosimetric methods employed. 44 refs.

  6. Commensurate germanium light emitters in silicon-on-insulator photonic crystal slabs.

    Science.gov (United States)

    Jannesari, R; Schatzl, M; Hackl, F; Glaser, M; Hingerl, K; Fromherz, T; Schäffler, F

    2014-10-20

    We report on the fabrication and characterization of silicon-on-insulator (SOI) photonic crystal slabs (PCS) with commensurately embedded germanium quantum dot (QD) emitters for near-infrared light emission. Substrate pre-patterning defines preferential nucleation sites for the self-assembly of Ge QDs during epitaxial growth. Aligned two-dimensional photonic crystal slabs are then etched into the SOI layer. QD ordering enhances the photoluminescence output as compared to PCSs with randomly embedded QDs. Rigorously coupled wave analysis shows that coupling of the QD emitters to leaky modes of the PCS can be tuned via their location within the unit cell of the PCS.

  7. Scattering of two photons on a quantum emitter in a one-dimensional waveguide: exact dynamics and induced correlations

    DEFF Research Database (Denmark)

    Nysteen, Anders; Kristensen, Philip Trøst; McCutcheon, Dara

    2015-01-01

    We develop a wavefunction approach to describe the scattering of two photons on a quantum emitter embedded in a one-dimensional waveguide. Our method allows us to calculate the exact dynamics of the complete system at all times, as well as the transmission properties of the emitter. We show...... that the nonlinearity of the emitter with respect to incoming photons depends strongly on the emitter excitation and the spectral shape of the incoming pulses, resulting in transmission of the photons which depends crucially on their separation and width. In addition, for counter-propagating pulses, we analyze...... the induced level of quantum correlations in the scattered state, and we show that the emitter behaves as a nonlinear beam-splitter when the spectral width of the photon pulses is similar to the emitter decay rate....

  8. Near-unity coupling efficiency of a quantum emitter to a photonic crystal waveguide.

    Science.gov (United States)

    Arcari, M; Söllner, I; Javadi, A; Lindskov Hansen, S; Mahmoodian, S; Liu, J; Thyrrestrup, H; Lee, E H; Song, J D; Stobbe, S; Lodahl, P

    2014-08-29

    A quantum emitter efficiently coupled to a nanophotonic waveguide constitutes a promising system for the realization of single-photon transistors, quantum-logic gates based on giant single-photon nonlinearities, and high bit-rate deterministic single-photon sources. The key figure of merit for such devices is the β factor, which is the probability for an emitted single photon to be channeled into a desired waveguide mode. We report on the experimental achievement of β=98.43%±0.04% for a quantum dot coupled to a photonic crystal waveguide, corresponding to a single-emitter cooperativity of η=62.7±1.5. This constitutes a nearly ideal photon-matter interface where the quantum dot acts effectively as a 1D "artificial" atom, since it interacts almost exclusively with just a single propagating optical mode. The β factor is found to be remarkably robust to variations in position and emission wavelength of the quantum dots. Our work demonstrates the extraordinary potential of photonic crystal waveguides for highly efficient single-photon generation and on-chip photon-photon interaction.

  9. Bright and stable visible-spectrum single photon emitter in silicon carbide

    CERN Document Server

    Lienhard, Benjamin; Mouradian, Sara; Dolde, Florian; Tran, Toan Trong; Aharonovich, Igor; Englund, Dirk R

    2016-01-01

    Single photon sources are of paramount importance in quantum communication, quantum computation, and quantum metrology. In particular, there is great interest to realize scalable solid state platforms that can emit triggered photons on demand to achieve scalable nanophotonic networks. We report on a visible-spectrum single photon emitter in 4H-silicon carbide (SiC). The emitter is photostable at room- and low-temperature enabling photon counts per second (cps) in excess of 2$\\times$10$^6$ from unpatterned, bulk SiC. It exists in two orthogonally polarized states, which have parallel absorption and emission dipole orientations. Low temperature measurements reveal a narrow zero phonon line (linewidth $30~$% of the total photoluminescence spectrum.

  10. High quality GaAs single photon emitters on Si substrate

    Energy Technology Data Exchange (ETDEWEB)

    Bietti, S.; Sanguinetti, S. [Dipartimento di Scienza dei Materiali and L-NESS, Università, di Milano Bicocca, Via Cozzi 53,I-20125 Milano (Italy); Cavigli, L.; Accanto, N.; Vinattieri, A. [Dipartimento di Fisica e Astronomia, LENS and CNISM, Università, di Firenze, Via Sansone 1, I-50019 Firenze (Italy); Minari, S.; Abbarchi, M. [Dipartimento di Fisica e Astronomia, LENS and CNISM, Universita di Firenze, Via Sansone 1, I-50019 Firenze (Italy); Isella, G. [Dipartimento di Fisica and L-NESS, Politecnico di Milano, Via Anzani 42, 22100 Como (Italy); Frigeri, C. [CNR-IMEM Institute, Parco Area delle Scienze 31/A, 43100 Parma (Italy); Gurioli, M. [Dipartimento di Fisica e Astronomia, LENS and CNISM, Universita, di Firenze, Via Sansone 1, I-50019 Firenze (Italy)

    2013-12-04

    We describe a method for the direct epitaxial growth of a single photon emitter, based on GaAs quantum dots fabricated by droplet epitaxy, working at liquid nitrogen temperatures on Si substrates. The achievement of quantum photon statistics up to T=80 K is directly proved by antibunching in the second order correlation function as measured with a H anbury Brown and Twiss interferometer.

  11. Phonon-Assisted Two-Photon Interference from Remote Quantum Emitters.

    Science.gov (United States)

    Reindl, Marcus; Jöns, Klaus D; Huber, Daniel; Schimpf, Christian; Huo, Yongheng; Zwiller, Val; Rastelli, Armando; Trotta, Rinaldo

    2017-07-12

    Photonic quantum technologies are on the verge of finding applications in everyday life with quantum cryptography and quantum simulators on the horizon. Extensive research has been carried out to identify suitable quantum emitters and single epitaxial quantum dots have emerged as near-optimal sources of bright, on-demand, highly indistinguishable single photons and entangled photon-pairs. In order to build up quantum networks, it is essential to interface remote quantum emitters. However, this is still an outstanding challenge, as the quantum states of dissimilar "artificial atoms" have to be prepared on-demand with high fidelity and the generated photons have to be made indistinguishable in all possible degrees of freedom. Here, we overcome this major obstacle and show an unprecedented two-photon interference (visibility of 51 ± 5%) from remote strain-tunable GaAs quantum dots emitting on-demand photon-pairs. We achieve this result by exploiting for the first time the full potential of a novel phonon-assisted two-photon excitation scheme, which allows for the generation of highly indistinguishable (visibility of 71 ± 9%) entangled photon-pairs (fidelity of 90 ± 2%), enables push-button biexciton state preparation (fidelity of 80 ± 2%) and outperforms conventional resonant two-photon excitation schemes in terms of robustness against environmental decoherence. Our results mark an important milestone for the practical realization of quantum repeaters and complex multiphoton entanglement experiments involving dissimilar artificial atoms.

  12. Broadband tunable hybrid photonic crystal-nanowire light emitter

    CERN Document Server

    Wilhelm, Christophe E; Xiong, Qihua; Soci, Cesare; Lehoucq, Gaëlle; Dolfi, Daniel; De Rossi, Alfredo; Combrié, Sylvain

    2015-01-01

    We integrate about 100 single Cadmium Selenide semiconductor nanowires in self-standing Silicon Nitride photonic crystal cavities in a single processing run. Room temperature measurements reveal a single narrow emission linewidth, corresponding to a Q-factor as large as 5000. By varying the structural parameters of the photonic crystal, the peak wavelength is tuned, thereby covering the entire emission spectral range of the active material. A very large spectral range could be covered by heterogeneous integration of different active materials.

  13. On-chip photonic-phononic emitter-receiver apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Jonathan Albert; Jarecki, Jr., Robert L.; Rakich, Peter Thomas; Wang, Zheng; Shin, Heedeuk; Siddiqui, Aleem; Starbuck, Andrew Lea

    2017-07-04

    A radio-frequency photonic devices employs photon-phonon coupling for information transfer. The device includes a membrane in which a two-dimensionally periodic phononic crystal (PnC) structure is patterned. The device also includes at least a first optical waveguide embedded in the membrane. At least a first line-defect region interrupts the PnC structure. The first optical waveguide is embedded within the line-defect region.

  14. Single photon transport in two waveguides chirally coupled by a quantum emitter.

    Science.gov (United States)

    Cheng, Mu-Tian; Ma, Xiao-San; Zhang, Jia-Yan; Wang, Bing

    2016-08-22

    We investigate single photon transport in two waveguides coupled to a two-level quantum emitter (QE). With the deduced analytical scattering amplitudes, we show that under condition of the chiral coupling between the QE and the photon in the two waveguides, the QE can play the role of ideal quantum router to redirect a single photon incident from one waveguide into the other waveguide with a probability of 100% in the ideal condition. The influences of cross coupling between two waveguides and dissipations on the routing are also shown.

  15. Lower Emittance Lattice for the Advanced Photon Source Upgrade Using Reverse Bending Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Borland, M.; Berenc, T.; Sun, Y.; Sajaev, V.

    2017-06-01

    The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring to a hybrid seven-bend-achromat design [1]. The nominal design provides a natural emittance of 67 pm [2]. By adding reverse dipole fields to several quadrupoles [3, 4] we can reduce the natural emittance to 41 pm while simultaneously providing more optimal beta functions in the insertion devices and increasing the dispersion function at the chromaticity sextupole magnets. The improved emittance results from a combination of increased energy loss per turn and a change in the damping partition. At the same time, the nonlinear dynamics performance is very similar, thanks in part to increased dispersion in the sextupoles. This paper describes the properties, optimization, and performance of the new lattice.

  16. Continuous-wave mid-infrared photonic crystal light emitters at room temperature

    Science.gov (United States)

    Weng, Binbin; Qiu, Jijun; Shi, Zhisheng

    2017-01-01

    Mid-infrared photonic crystal enhanced lead-salt light emitters operating under continuous-wave mode at room temperature were investigated in this work. For the device, an active region consisting of 9 pairs of PbSe/Pb0.96Sr0.04Se quantum wells was grown by molecular beam epitaxy method on top of a Si(111) substrate which was initially dry-etched with a two-dimensional photonic crystal structure in a pattern of hexagonal holes. Because of the photonic crystal structure, an optical band gap between 3.49 and 3.58 µm was formed, which matched with the light emission spectrum of the quantum wells at room temperature. As a result, under optical pumping, using a near-infrared continuous-wave semiconductor laser, the device exhibited strong photonic crystal band-edge mode emissions and delivered over 26.5 times higher emission efficiency compared to the one without photonic crystal structure. The output power obtained was up to 7.68 mW (the corresponding power density was 363 mW/cm2), and a maximum quantum efficiency reached to 1.2%. Such photonic crystal emitters can be used as promising light sources for novel miniaturized gas-sensing systems.

  17. Light scattering and photon statistics of quantum emitters coupled to metallic nanoparticles

    Directory of Open Access Journals (Sweden)

    O. Di Stefano

    2011-09-01

    Full Text Available We study theoretically the quantum optical properties of hybrid artificial molecules composed of an individual quantum emitter and a metallic nanoparticle. The coupling between the two systems can give rise to a Fano interference effect which strongly influences the quantum statistical properties of the scattered photons: a small frequency shift of the incident light field may cause changes in the intensity correlation function of the scattered field of orders of magnitude. The system opens a good perspective for applications in active metamaterials and ultracompact single-photon devices. We also demonstrate with accurate scattering calculations that a system constituted by a single quantum emitter (a semiconductor quantum dot placed in the gap between two metallic nanoparticles can display the vacuum Rabi splitting.

  18. PECASE: Resonantly-Enhanced Lanthanide Emitters for Subwavelength-Scale, Active Photonics

    Science.gov (United States)

    2015-03-19

    AFRL-AFOSR-VA-TR-2016-0052 PECASE- RESONATLY-ENHANCHED LANTHANIDE EMITTERS FOR SUBWAVELENGTH-SCALE, ACTIVE Photonics Rashid Zia BROWN UNIVERSITY IN... Rashid Zia and Jonathan A. Kurvits 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION...during reporting period: [1] Christopher M. Dodson and Rashid Zia, “Magnetic dipole and electric quadrupole transitions in the trivalent lanthanide

  19. Microwave Photonic Architecture for Direction Finding of LPI Emitters: Front End Analog Circuit Design and Component Characterization

    Science.gov (United States)

    2016-09-01

    PHOTONIC ARCHITECTURE FOR DIRECTION FINDING OF LPI EMITTERS: FRONT-END ANALOG CIRCUIT DESIGN AND COMPONENT CHARACTERIZATION by Chew K. Tan...PHOTONIC ARCHITECTURE FOR DIRECTION FINDING OF LPI EMITTERS: FRONT-END ANALOG CIRCUIT DESIGN AND COMPONENT CHARACTERIZATION 5. FUNDING NUMBERS 6. AUTHOR... ANALOG CIRCUIT DESIGN AND COMPONENT CHARACTERIZATION Chew K. Tan Military Expert 6, Republic of Singapore Navy B.E. (Hons), University of New

  20. Statistics of scattered photons from a driven three-level emitter in 1D open space

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Dibyendu [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Div. and Center for Nonlinear Studies; Bondyopadhaya, Nilanjan [Visva-Bharati University, Santiniketan (India). Integrated Science Education and Research Centre

    2014-01-07

    We derive the statistics of scattered photons from a Λ- or ladder-type three-level emitter (3LE) embedded in a 1D open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency (EIT) which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as strength of the control beam is ramped up from zero to a higher value where the ATS appears.

  1. A stable, single-photon emitter in a thin organic crystal for application to quantum-photonic devices

    CERN Document Server

    Polisseni, Claudio; Boissier, Sebastien; Grandi, Samuele; Clark, Alex S; Hinds, E A

    2016-01-01

    Single organic molecules offer great promise as bright, reliable sources of identical single photons on demand, capable of integration into solid-state devices. It has been proposed that such molecules in a crystalline organic matrix might be placed close to an optical waveguide for this purpose, but so far there have been no demonstrations of sufficiently thin crystals, with a controlled concentration of suitable dopant molecules. Here we present a method for growing very thin anthracene crystals from super-saturated vapour, which produces crystals of extreme flatness and controlled thickness. We show how this crystal can be doped with a widely adjustable concentration of dibenzoterrylene (DBT) molecules and we examine the optical properties of these molecules to demonstrate their suitability as quantum emitters in nanophotonic devices. Our measurements show that the molecules are available in the crystal as single quantum emitters, with a well-defined polarisation relative to the crystal axes, making them a...

  2. Efficiency droop in indium gallium nitride light emitters: An introduction to photon quenching processes

    Science.gov (United States)

    Sarkissian, Raymond

    This thesis contains work from two separate projects, a study of the efficiency of light emitting diodes, and a tapered-fiber approach to photonic crystal integrated photonics. The first part of this thesis describes an experimental investigation of the quantum efficiency of InGaN-based light emitters. Blue and Green LEDs that utilize InGaN quantum wells for their active medium suffer from a reduction in efficiency with increasing bias. This phenomenon is called efficiency droop. In this thesis experimental evidence for significant quenching of photon population in InGaN is presented and its relevance to the efficiency droop problem in InGaN-based light emitting structures is discussed. An equilibrium rate equation model is set up to demonstrate that radiative efficiency for this loss mechanism not only has a similar dependence on carrier density as Auger recombination process, but it also possesses the right order of magnitude making it difficult to distinguish between the two and possibly leading to errors in interpretation. The impact of photon quenching processes on device performance is emphasized by demonstrating loss of efficiency for spectral regions where there is experimental evidence for photon quenching. We have observed this phenomenon for both c-plane and m-plane light emitting structures. Both structures exhibit droop-like behavior for spectral regions where there is evidence for photon quenching. We have also observed and characterized the dynamical Stark effect for an m-plane light emitter considered in this manuscript. Our results revealed localization centers with a corresponding band-edge energy of 388nm and an excitonic binding energy of 17.81mev. Furthermore, fabrication of a photonic crystal waveguide fiber taper coupler is demonstrated with a peak coupling efficiency of 97 %. All four ports of the device are accessible providing an opportunity for investigation of simultaneous interaction of different light sources inside the photonic

  3. Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide

    Science.gov (United States)

    Fuchs, F.; Stender, B.; Trupke, M.; Simin, D.; Pflaum, J.; Dyakonov, V.; Astakhov, G. V.

    2015-07-01

    Vacancy-related centres in silicon carbide are attracting growing attention because of their appealing optical and spin properties. These atomic-scale defects can be created using electron or neutron irradiation; however, their precise engineering has not been demonstrated yet. Here, silicon vacancies are generated in a nuclear reactor and their density is controlled over eight orders of magnitude within an accuracy down to a single vacancy level. An isolated silicon vacancy serves as a near-infrared photostable single-photon emitter, operating even at room temperature. The vacancy spins can be manipulated using an optically detected magnetic resonance technique, and we determine the transition rates and absorption cross-section, describing the intensity-dependent photophysics of these emitters. The on-demand engineering of optically active spins in technologically friendly materials is a crucial step toward implementation of both maser amplifiers, requiring high-density spin ensembles, and qubits based on single spins.

  4. Experimental Demonstration of a Hybrid-Quantum-Emitter Producing Individual Entangled Photon Pairs in the Telecom Band

    Science.gov (United States)

    Chen, Geng; Zou, Yang; Zhang, Wen-Hao; Zhang, Zi-Huai; Zhou, Zong-Quan; He, De-Yong; Tang, Jian-Shun; Liu, Bi-Heng; Yu, Ying; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Han, Yong-Jian; Li, Chuan-Feng; Guo, Guang-Can

    2016-05-01

    Quantum emitters generating individual entangled photon pairs (IEPP) have significant fundamental advantages over schemes that suffer from multiple photon emission, or schemes that require post-selection techniques or the use of photon-number discriminating detectors. Quantum dots embedded within nanowires (QD-NWs) represent one of the most promising candidate for quantum emitters that provide a high collection efficiency of photons. However, a quantum emitter that generates IEPP in the telecom band is still an issue demanding a prompt solution. Here, we demonstrate in principle that IEPPs in the telecom band can be created by combining a single QD-NW and a nonlinear crystal waveguide. The QD-NW system serves as the single photon source, and the emitted visible single photons are split into IEPPs at approximately 1.55 μm through the process of spontaneous parametric down conversion (SPDC) in a periodically poled lithium niobate (PPLN) waveguide. The compatibility of the QD-PPLN interface is the determinant factor in constructing this novel hybrid-quantum-emitter (HQE). Benefiting from the desirable optical properties of QD-NWs and the extremely high nonlinear conversion efficiency of PPLN waveguides, we successfully generate IEPPs in the telecom band with the polarization degree of freedom. The entanglement of the generated photon pairs is confirmed by the entanglement witness. Our experiment paves the way to producing HQEs inheriting the advantages of multiple systems.

  5. Fabrication of an Omnidirectional 2D Photonic Crystal Emitter for Thermophotovoltaics

    Science.gov (United States)

    Stelmakh, V.; Chan, W. R.; Ghebrebrhan, M.; Soljacic, M.; Joannopoulos, J. D.; Celanovic, I.

    2016-11-01

    In a thermophotovoltaic (TPV) system, a heat source brings an emitter to incandescence and the spectrally confined thermal radiation is converted to electricity by a low-bandgap photovoltaic (PV) cell. Efficiency is dominated by the emitter's ratio of in-band emissivity (convertible by the PV cell) to out-of-band emissivity (inconvertible). Two-dimensional photonic crystals (PhCs) offer high in-band emissivity and low out-of-band emissivity at normal incidence, but have reduced in-band emissivity off-normal. According to Lambert's law, most thermal radiation occurs off-normal. An omnidirectional PhC capable of high in-band emissivity at all angles would increase total in-band power by 55% at 1200°C. In this work, we present the first experimental demonstration an omnidirectional hafnia-filled 2D tantalum PhC emitter suitable for TPV applications such as combustion, radioisotope, and solar TPV. Dielectric filling improved the hemispherical performance without sacrificing stability or ease of fabrication. The numerical simulations, fabrication processes, and optical and thermal characterizations of the PhC are presented in this paper.

  6. Low emittance pion beams generation from bright photons and relativistic protons

    CERN Document Server

    Serafini, L; Petrillo, V

    2015-01-01

    Present availability of high brilliance photon beams as those produced by X-ray Free Electron Lasers in combination with intense TeV proton beams typical of the Large Hadron Collider makes it possible to conceive the generation of pion beams via photo-production in a highly relativistic Lorentz boosted frame: the main advantage is the low emittance attainable and a TeV-class energy for the generated pions, that may be an interesting option for the production of low emittance muon and neutrino beams. We will describe the kinematics of the two classes of dominant events, i.e. the pion photo-production and the electron/positron pair production, neglecting other small cross-section possible events like Compton and muon pair production. Based on the phase space distributions of the pion and muon beams we will analyze the pion beam brightness achievable in three examples, based on advanced high efficiency high repetition rate FELs coupled to LHC or Future Circular Collider (FCC) proton beams, together with the stud...

  7. Temperature tunability of quantum emitter - cavity coupling in a photonic wire microcavity with shielded sidewall loss

    CERN Document Server

    Bernard, M

    2016-01-01

    Recent technological advancements have allowed to implement in solid-state cavity-based devices phenomena of quantum nature such as vacuum Rabi splitting, controllable single photon emission and quantum entanglement. For a sufficiently strong coupling between a quantum emitter and a cavity, large quality factors ($Q$) along with small modal volume ($V_{eff}$) are essential. Here we show that by applying a 5nm Al coating to the sidewalls of a submicrometer-sized Fabry-P\\'{e}rot microcavity, the cavity $Q$ can be temperature-tuned from few hundreds at room temperatures to 2$\\times$10$^5$ below 30~K. This is achieved by, first, a complete shielding of the sidewall loss with ideally reflecting lateral metallic mirrors and, secondly, a dramatic decrease of the cavity's axial loss for small-sized devices due to the largely off-axis wavevector within the multilayered structure. Our findings offer a novel temperature-tunable platform to study quantum electrodynamical phenomena of emitter-cavity coupling. We demonstra...

  8. Statistical measurements of quantum emitters coupled to Anderson-localized modes in disordered photonic-crystal waveguides

    NARCIS (Netherlands)

    Javadi, A.; Maibom, S.; Sapienza, L.; Thyrrestrup Nielsen, H.; Garcia, P.D.; Lodahl, P.

    2014-01-01

    We present a statistical study of the Purcell enhancement of the light emission from quantum dots coupled to Anderson-localized cavities formed in disordered photonic-crystal waveguides. We measure the time-resolved light emission from both single quantum emitters coupled to Anderson-localized cavit

  9. Pulsed sextupole injection for Beijing Advanced Photon Source with ultralow emittance

    CERN Document Server

    Yi, JIAO

    2013-01-01

    In this paper we present the physical design of the pulsed sextupole injection system for Beijing Advanced Photon Source (BAPS) with an ultralow emittance. The BAPS ring lattice is designed in such a way that two options of pulsed sextupole injection are allowed, i.e., with septum and pulsed sextupole in different drift spaces or in the same drift space. We give the magnetic parameters of the injection system and the optimal condition of the optical functions for both options. In addition, we find that the pulsed sextupole induces position-dependent dispersive effect and causes non-ignorable effect on the injection efficiency in a storage ring with a relatively small acceptance, which should be well considered.

  10. Heralded quantum repeater based on the scattering of photons off single emitters using parametric down-conversion source.

    Science.gov (United States)

    Song, Guo-Zhu; Wu, Fang-Zhou; Zhang, Mei; Yang, Guo-Jian

    2016-06-28

    Quantum repeater is the key element in quantum communication and quantum information processing. Here, we investigate the possibility of achieving a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We design the compact quantum circuits for nonlocal entanglement generation, entanglement swapping, and entanglement purification, and discuss the feasibility of our protocols with current experimental technology. In our scheme, we use a parametric down-conversion source instead of ideal single-photon sources to realize the heralded quantum repeater. Moreover, our protocols can turn faulty events into the detection of photon polarization, and the fidelity can reach 100% in principle. Our scheme is attractive and scalable, since it can be realized with artificial solid-state quantum systems. With developed experimental technique on controlling emitter-waveguide systems, the repeater may be very useful in long-distance quantum communication.

  11. Fundamental Limits to Coherent Scattering and Photon Coalescence from Solid-State Quantum Emitters [arXiv

    DEFF Research Database (Denmark)

    Iles-Smith, Jake; McCutcheon, Dara; Mørk, Jesper

    2016-01-01

    The desire to produce high-quality single photons for applications in quantum information science has lead to renewed interest in exploring solid-state emitters in the weak excitation regime. Under these conditions it is expected that photons are coherently scattered, and so benefit from...... find that the sideband resulting from non-Markovian relaxation of the phonon environment leads to a fundamental limit to the fraction of coherently scattered light and to the visibility of two-photon coalescence at weak driving, both of which are absent for atomic systems or within simpler Markovian...

  12. The visibility of Lyman Alpha Emitters: constraining reionization, ionizing photons and dust

    CERN Document Server

    Hutter, A; Partl, A M; Müller, V

    2014-01-01

    We couple state of the art cosmological simulations (GADGET-2) with a dust model and a radiative transfer code (pCRASH) to build a complete model for high-redshift Lyman Alpha emitters (LAEs). Due to poor constraints available on the escape fraction of HI ionizing photons (f_esc) from galaxies, we use five different values f_esc=0.05,0.25,0.5,0.75,0.95 to post-process the cosmological simulation with pCRASH. Starting from a completely neutral Universe, we run pCRASH until reionization is complete, i.e. the average neutral hydrogen (HI) fraction drops to ~ 10^-4. For a given f_esc and combination, the only free-parameter left to match model results to observations is the relative escape of Lyman Alpha (Lya) and continuum photons from the galactic environment (f_\\alpha/f_c). Starting from a scenario wherein dust is homogeneously distributed (f_\\alpha/f_c ~ 0.68), we find that the observed LAE UV and Lya luminosity functions (LFs) jointly constrain f_esc ~ 0.05 and and f_\\alpha/f_c such that a decrease in th...

  13. Ordered arrays of InGaN/GaN dot-in-a-wire nanostructures as single photon emitters

    Science.gov (United States)

    Lazić, Snežana; Chernysheva, Ekaterina; Gačević, Žarko; García-Lepetit, Noemi; van der Meulen, Herko P.; Müller, Marcus; Bertram, Frank; Veit, Peter; Christen, Jürgen; Torres-Pardo, Almudena; González Calbet, José M.; Calleja, Enrique; Calleja, José M.

    2015-03-01

    The realization of reliable single photon emitters operating at high temperature and located at predetermined positions still presents a major challenge for the development of solid-state systems for quantum light applications. We demonstrate single-photon emission from two-dimensional ordered arrays of GaN nanowires containing InGaN nanodisks. The structures were fabricated by molecular beam epitaxy on (0001) GaN-on-sapphire templates patterned with nanohole masks prepared by colloidal lithography. Low-temperature cathodoluminescence measurements reveal the spatial distribution of light emitted from a single nanowire heterostructure. The emission originating from the topmost part of the InGaN regions covers the blue-to-green spectral range and shows intense and narrow quantum dot-like photoluminescence lines. These lines exhibit an average linear polarization ratio of 92%. Photon correlation measurements show photon antibunching with a g(2)(0) values well below the 0.5 threshold for single photon emission. The antibunching rate increases linearly with the optical excitation power, extrapolating to the exciton decay rate of ~1 ns-1 at vanishing pump power. This value is comparable with the exciton lifetime measured by time-resolved photoluminescence. Fast and efficient single photon emitters with controlled spatial position and strong linear polarization are an important step towards high-speed on-chip quantum information management.

  14. Mid-infrared quantum dot emitters utilizing planar photonic crystal technology.

    Energy Technology Data Exchange (ETDEWEB)

    Subramania,Ganapathi Subramanian; Lyo, Sungkwun Kenneth; Cederberg, Jeffrey George; Passmore, Brandon Scott; El-Kady, Ihab Fathy; Shaner, Eric Arthur

    2008-09-01

    The three-dimensional confinement inherent in InAs self-assembled quantum dots (SAQDs) yields vastly different optical properties compared to one-dimensionally confined quantum well systems. Intersubband transitions in quantum dots can emit light normal to the growth surface, whereas transitions in quantum wells emit only parallel to the surface. This is a key difference that can be exploited to create a variety of quantum dot devices that have no quantum well analog. Two significant problems limit the utilization of the beneficial features of SAQDs as mid-infrared emitters. One is the lack of understanding concerning how to electrically inject carriers into electronic states that allow optical transitions to occur efficiently. Engineering of an injector stage leading into the dot can provide current injection into an upper dot state; however, to increase the likelihood of an optical transition, the lower dot states must be emptied faster than upper states are occupied. The second issue is that SAQDs have significant inhomogeneous broadening due to the random size distribution. While this may not be a problem in the long term, this issue can be circumvented by using planar photonic crystal or plasmonic approaches to provide wavelength selectivity or other useful functionality.

  15. Monte Carlo calculation of dose rate conversion factors for external exposure to photon emitters in soil

    CERN Document Server

    Clouvas, A; Antonopoulos-Domis, M; Silva, J

    2000-01-01

    The dose rate conversion factors D/sub CF/ (absorbed dose rate in air per unit activity per unit of soil mass, nGy h/sup -1/ per Bq kg/sup -1/) are calculated 1 m above ground for photon emitters of natural radionuclides uniformly distributed in the soil. Three Monte Carlo codes are used: 1) The MCNP code of Los Alamos; 2) The GEANT code of CERN; and 3) a Monte Carlo code developed in the Nuclear Technology Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte Carlo results is tested by the comparison of the unscattered flux obtained by the three Monte Carlo codes with an independent straightforward calculation. All codes and particularly the MCNP calculate accurately the absorbed dose rate in air due to the unscattered radiation. For the total radiation (unscattered plus scattered) the D/sub CF/ values calculated from the three codes are in very good agreement between them. The comparison between these results and the results deduced previously by other authors indicates a good ag...

  16. Heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Song, Guo-Zhu; Zhang, Mei; Ai, Qing; Yang, Guo-Jian [Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875 (China); Alsaedi, Ahmed; Hobiny, Aatef [NAAM-Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Deng, Fu-Guo, E-mail: fgdeng@bnu.edu.cn [Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875 (China); NAAM-Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia)

    2017-03-15

    We propose a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We show the details by implementing nonlocal entanglement generation, entanglement swapping, and entanglement purification modules with atoms in waveguides, and discuss the feasibility of the repeater with currently achievable technology. In our scheme, the faulty events can be discarded by detecting the polarization of the photons. That is, our protocols are accomplished with a fidelity of 100% in principle, which is advantageous for implementing realistic long-distance quantum communication. Moreover, additional atomic qubits are not required, but only a single-photon medium. Our scheme is scalable and attractive since it can be realized in solid-state quantum systems. With the great progress on controlling atom-waveguide systems, the repeater may be very useful in quantum information processing in the future.

  17. International photonics training: a case study

    Science.gov (United States)

    Sporea, Dan; Massa, Nicholas; Donnelly, Judith F.; Hanes, Fenna

    2007-06-01

    From 2004, the Center for Science Education and Training (CSET) participated to the European Union-funded educational network "Hands-on Science". The aim of the Romanian team was to transform teachers and students from end-users of educational aids to active designers and developers of instructional materials. Several science fields were identified, including photonics. The team at CSET is now focusing on: lasers and their applications, optical fiber communications, solar energy as a sustainable source, and the use of optical spectroscopy in physics and chemistry. CSET initiated an international collaboration with the New England Board of Higher Education (NEBHE) in Boston, Mass., when the Center enrolled an experienced Romanian high school science teacher in a twelve-week "Introduction to Photonics" laboratory-based professional development course. The course was developed by NEBHE through an Advanced Technological Education (ATE) program grant from National Science Foundation and is designed for high school and community college educators from both science and technology instructional areas. The paper reports the experience of this international participation which was made possible since the course is delivered via the Internet by Three Rivers Community College, Norwich, Conn. Its impact on photonics education in Romania and the USA is analyzed, as the participant teacher shares her experiences with teachers and faculty in the "Introduction to Photonics" course and with those enrolled into the Romanian "Hands-on-Science" program.

  18. Design of main linac emittance tuning bumps for the Compact Linear Collider and the International Linear Collider

    Directory of Open Access Journals (Sweden)

    Peder Eliasson

    2008-01-01

    Full Text Available The installation of elements in the main linac of future linear colliders can only be done with a limited precision. The inevitable misalignments lead to unacceptable emittance growth. Beam-based alignment, e.g., one-to-one correction, dispersion free steering, or ballistic alignment, is necessary to reduce the emittance growth. In some cases, this is, however, not sufficient. For further reduction of the emittance growth, so-called emittance tuning bumps have to be used. A general strategy for the design of emittance tuning bumps has been developed and tested. Simulations suggest that the method can be conveniently used to understand the weaknesses of existing emittance tuning bumps and to significantly improve their performance in terms of, e.g., emittance reduction capability and convergence speed. An example of an application is the design of ten orthogonal knobs that, according to simulations, can reduce the normalized emittance growth in the Compact Linear Collider (CLIC main linac from 23.8 to 0.34 nm with convergence within two iterations. Four orthogonal knobs have also been designed for the International Linear Collider (ILC. Simulations show that these knobs converge within a single iteration and reduce normalized emittance growth from 3.8 to 0.05 nm.

  19. Vertically integrated (Ga, In)N nanostructures for future single photon emitters operating in the telecommunication wavelength range.

    Science.gov (United States)

    Winden, A; Mikulics, M; Grützmacher, D; Hardtdegen, H

    2013-10-11

    Important technological steps are discussed and realized for future room-temperature operation of III-nitride single photon emitters. First, the growth technology of positioned single pyramidal InN nanostructures capped by Mg-doped GaN is presented. The optimization of their optical characteristics towards narrowband emission in the telecommunication wavelength range is demonstrated. In addition, a device concept and technology was developed so that the nanostructures became singularly addressable. It was found that the nanopyramids emit in the telecommunication wavelength range if their size is chosen appropriately. A p-GaN contacting layer was successfully produced as a cap to the InN pyramids and the top p-contact was achievable using an intrinsically conductive polymer PEDOT:PSS, allowing a 25% increase in light transmittance compared to standard Ni/Au contact technology. Single nanopyramids were successfully integrated into a high-frequency device layout. These decisive technology steps provide a promising route to electrically driven and room-temperature operating InN based single photon emitters in the telecommunication wavelength range.

  20. Control of coherent information via on chip photonic-phononic emitter-receivers

    CERN Document Server

    Shin, Heedeuk; Jarecki, Robert; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T

    2014-01-01

    Rapid progress in silicon photonics has fostered numerous chip-scale sensing, computing, and signal processing technologies. However, many crucial filtering and signal delay operations are difficult to perform with all-optical devices. Unlike photons propagating at luminal speeds, GHz-acoustic phonons with slow velocity allow information to be stored, filtered, and delayed over comparatively smaller length-scales with remarkable fidelity. Hence, controllable and efficient coupling between coherent photons and phonons enables new signal processing technologies that greatly enhance the performance and potential impact of silicon photonics. Here, we demonstrate a novel mechanism for coherent information processing based on traveling-wave photon-phonon transduction, which achieves a phonon emit-and-receive process between distinct nanophotonic waveguides. Using this device physics-which can support 1-20GHz frequencies-we create wavelength-insensitive radio-frequency photonic filters with an unrivaled combination ...

  1. Control over few-photon pulses by a time-periodic modulation of the photon emitter coupling

    Science.gov (United States)

    Pletyukhov, Mikhail; Pedersen, Kim G. L.; Gritsev, Vladimir

    2017-04-01

    We develop a Floquet scattering formalism for the description of quasistationary states of microwave photons in a one-dimensional waveguide interacting with a nonlinear cavity by means of a periodically modulated coupling. This model is inspired by the recent progress in engineering of tunable coupling schemes with superconducting qubits. We argue that our model can realize the quantum analog of an optical chopper. We find strong periodic modulations of the transmission and reflection envelopes in the scattered few-photon pulses, including photon compression and blockade, as well as dramatic changes in statistics. Our theoretical analysis allows us to explain these nontrivial phenomena as arising from nonadiabatic memory effects.

  2. Treatment planning for internal emitter therapy: Methods, applications and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Sgouros, G. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    1999-01-01

    Treatment planning involves three basic steps: (1) a procedure must be devised that will provide the most relevant information, (2) the procedure must be applied and (3) the resulting information must be translated into a definition of the optimum implementation. There are varying degrees of treatment planning that may be implemented in internal emitter therapy. As in chemotherapy, the information from a Phase 1 study may be used to treat patients based upon body surface area. If treatment planning is included on a patient-specific basis, a pretherapy, trace-labeled, administration of the radiopharmaceutical is generally required. The data collected following the tracer dose may range from time-activity curves of blood and whole-body for use in blood, marrow or total body absorbed dose estimation to patient imaging for three-dimensional internal emitter dosimetry. The most ambitious approach requires a three-dimensional set of images representing radionuclide distribution (SPECT or PET) and a corresponding set of images representing anatomy (CT or MRI). The absorbed dose (or dose-rate) distribution may be obtained by convolution of a point kernel with the radioactivity distribution or by direct Monte Carlo calculation. A critical requirement for both techniques is the development of an overall structure that makes it possible, in a routine manner, to input the images, to identify the structures of interest and to display the results of the dose calculations in a clinically relevant manner. 52 refs., 4 figs., 1 tab.

  3. Control of spontaneous emission of a single quantum emitter through a time-modulated photonic-band-gap environment

    Science.gov (United States)

    Calajò, Giuseppe; Rizzuto, Lucia; Passante, Roberto

    2017-08-01

    We consider the spontaneous emission of a two-level quantum emitter, such as an atom or a quantum dot, in a modulated time-dependent environment with a photonic band gap. An example of such an environment is a dynamical photonic crystal or any other environment with a band gap whose properties are modulated in time, in the effective mass approximation. After introducing our model of a dynamical photonic crystal, we show that it allows new possibilities to control and tailor the physical features of the emitted radiation, specifically its frequency spectrum. In the weak-coupling limit and in an adiabatic case, we obtain the emitted spectrum and we show the appearance of two lateral peaks due to the presence of the modulated environment, separated from the central peak by the modulation frequency. We show that the two side peaks are not symmetric in height, and that their height ratio can be exploited to investigate the density of states of the environment. Our results show that a dynamical environment can give further possibilities to modify the spontaneous emission features, such as its spectrum and emission rate, with respect to a static one. Observability of the phenomena we obtain is discussed, as well as relevance for tailoring and engineering radiative processes.

  4. Heterostructures with CdTe/ZnTe quantum dots for single photon emitters grown by molecular beam epitaxy

    Science.gov (United States)

    Sorokin, S. V.; Sedova, I. V.; Gronin, S. V.; Belyaev, K. G.; Rakhlin, M. V.; Toropov, A. A.; Mukhin, I. S.; Ivanov, S. V.

    2016-12-01

    We report on the molecular beam epitaxy (MBE) of heterostructures with CdTe/ZnTe quantum dots (QDs) with relatively low surface density, which could be used as single-photon emitters. The QDs were formed on the surface of a 3.1- to 4.5-monolayer-thick two-dimensional strained CdTe layer by depositing amorphous Te layer and its fast thermal desorption. Subsequent thermal annealing of the surface with QDs in the absence of external Te flux led to strong broadening and short-wavelength shift of the QD photoluminescence (PL) peak. Measurement of the micro-PL spectra of individual CdTe/ZnTe quantum dots in fabricated mesastructures with a diameter of 200—1000 nm allowed estimation of the QD surface density as 1010 cm-2.

  5. Statistics of decay dynamics of quantum emitters in disordered photonic-crystal waveguides

    DEFF Research Database (Denmark)

    Javadi, Alisa; Garcia-Fernandez, Pedro David; Sapienza, Luca;

    2014-01-01

    We present a statistical analysis of the spontaneous emission of quantum dots coupled to Anderson-localized cavities in disordered photonic-crystal waveguides.We observe an average Purcell factor of ∼ 5 with a maximum value of 24.......We present a statistical analysis of the spontaneous emission of quantum dots coupled to Anderson-localized cavities in disordered photonic-crystal waveguides.We observe an average Purcell factor of ∼ 5 with a maximum value of 24....

  6. Fluorescence lifetime of emitters with broad homogeneous linewidths modified in opal photonic crystals

    DEFF Research Database (Denmark)

    Nikolaev, Ivan S.; Lodahl, Peter; Vos, Willem L.

    2008-01-01

    We have investigated the dynamics of spontaneous emission from dye molecules embedded in opal photonic crystals. Fluorescence lifetimes of Rhodamine 6G (R6G) dye were measured as a function of both optical frequency and crystal lattice parameter of the polystyrene opals. Due to the broad homogene...

  7. Control of single photon emitters in semiconductor nanowires by surface acoustic waves

    Science.gov (United States)

    Lazić, S.; Hernández-Mínguez, A.; Santos, P. V.

    2017-08-01

    We report on an experimental study into the effects of surface acoustic waves on the optical emission of dot-in-a-nanowire heterostructures in III-V material systems. Under direct optical excitation, the excitonic energy levels in III-nitride dot-in-a-nanowire heterostructures oscillate at the acoustic frequency, producing a characteristic splitting of the emission lines in the time-integrated photoluminescence spectra. This acoustically induced periodic tuning of the excitonic transition energies is combined with spectral detection filtering and employed as a tool to regulate the temporal output of anti-bunched photons emitted from these nanowire quantum dots. In addition, the acoustic transport of electrons and holes along a III-arsenide nanowire injects the electric charges into an ensemble of quantum dot-like recombination centers that are spatially separated from the optical excitation area. The acoustic population and depopulation mechanism determines the number of carrier recombination events taking place simultaneously in the ensemble, thus allowing control of the anti-bunching degree of the emitted photons. The results presented are relevant for the dynamic control of single photon emission in III-V semiconductor heterostructures.

  8. Si-based light emitter in an integrated photonic circuit for smart biosensor applications

    Science.gov (United States)

    Germer, S.; Cherkouk, C.; Rebohle, L.; Helm, M.; Skorupa, W.

    2013-05-01

    The motivation for integrated Silicon-based optoelectronics is the creation of low-cost photonics for mass-market applications. Especially, the growing demand for sensitive biochemical sensors in the environmental control or medicine leads to the development of integrated high resolution sensors. Here we present initial results in the integration and butt-coupling of a Si-based light emitting device (LED) [1-3] to a waveguide into a photonic circuit. Our first approach deals with the design, fabrication and characterization of the dielectric high contrast waveguide as an important component, beside the LED, for the development of a Si-based biodetection system. In this work we demonstrate design examples of Si3N4/SiO2-waveguides, which were calculated using MATLAB, the effective index method (EIM) and the finite element method (FEM), with a 0.45μm thick and 0.7μm wide core which shows a high confinement factor of ~74% and coupling efficiency of ~66% at 1.55μm, respectively. The fabrication was done by plasma enhanced chemical vapour deposition (PECVD), optical lithography and reactive ion etching (RIE). Additionally, we characterized the deposited layers via ellipsometry and the etched structures by scanning electron microscopy (SEM). The obtained results establish principles for Si-based LED butt-coupling to a powerful optical waveguide-based interconnect with effective light absorption and an adequate coupling efficiency.

  9. Biokinetic and dosimetric modelling in the estimation of radiation risks from internal emitters.

    Science.gov (United States)

    Harrison, John

    2009-06-01

    . Radon-222 is the one internal emitter for which control of exposure is based on direct information on cancer risks, with extensive information available on lung cancer induction by radon progeny in mines and consistent data on risks in homes. The dose per unit (222)Rn exposure can be calculated by comparing lung cancer risk estimates derived for (222)Rn exposure and for external exposure of the Japanese survivors. Remarkably similar values are obtained by this method and by calculations using the ICRP model of the respiratory tract, providing good support for model assumptions. Other informative comparisons with risks from external exposure can be made for Thorotrast-induced liver cancer and leukaemia, and radium-induced bone cancer. The bone-seeking alpha emitters, plutonium-239 and radium isotopes, are poorer leukaemogens than predicted by models. ICRP dose coefficients are published as single values without consideration of uncertainties. However, it is clear that full consideration of uncertainties is appropriate when considering best estimates of doses and risks to individuals or specific population groups. An understanding of the component uncertainties in the calculation of dose coefficients can be seen as an important goal and should help inform judgements on the control of exposures. The routine consideration of uncertainties in dose assessments, if achievable, would be of questionable value when doses are generally maintained at small fractions of limits.

  10. Highly reduced fine-structure splitting in InAs/InP quantum dots offering an efficient on-demand entangled 1.55-microm photon emitter.

    Science.gov (United States)

    He, Lixin; Gong, Ming; Li, Chuan-Feng; Guo, Guang-Can; Zunger, Alex

    2008-10-10

    To generate entangled photon pairs via quantum dots (QDs), the exciton fine-structure splitting (FSS) must be comparable to the exciton homogeneous linewidth. Yet in the (In,Ga)As/GaAs QD, the intrinsic FSS is about a few tens microeV. To achieve photon entanglement, it is necessary to cherry-pick a sample with extremely small FSS from a large number of samples or to apply a strong in-plane magnetic field. Using theoretical modeling of the fundamental causes of FSS in QDs, we predict that the intrinsic FSS of InAs/InP QDs is an order of magnitude smaller than that of InAs/GaAs dots, and, better yet, their excitonic gap matches the 1.55 microm fiber optic wavelength and, therefore, offers efficient on-demand entangled photon emitters for long distance quantum communication.

  11. Dispersion Properties in Total Internal Reflective Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    WEN Hua; HAO Dong-shan

    2004-01-01

    The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index, effective normalized frequency and dispersion management solitons. It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion. The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.

  12. Ultimate parameters of the photon collider at the international linear collider

    Indian Academy of Sciences (India)

    V I Telnov

    2007-12-01

    At linear colliders, the + - luminosity is limited by beam-collision effects, which determine the required emittances of beams in damping rings (DRs). In collisions at the photon collider, these effects are absent, and so smaller emittances are desirable. In the present damping ring designs, nominal DR parameters correspond to those required for + - collisions. In this note, I would like to stress once again that as soon as we plan the photon collider mode of ILC operation, the damping ring emittances are dictated by the photon collider requirements - namely, they should be as small as possible. This can be achieved by adding more wigglers to the DRs; the incremental cost is easily justified by a considerable potential improvement of the luminosity. No expert analysis exists as of now, but it seems realistic to obtain a factor five increase of the luminosity compared to the `nominal' DR design.

  13. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1985-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. We determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentially exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individual more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. We computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. 14 refs., 8 tabs.

  14. Internal conversions in Higgs decays to two photons

    OpenAIRE

    Firan, Ana; Stroynowski, Ryszard

    2007-01-01

    We evaluate the partial widths for internal conversions in the Higgs decays to two photons. For the Higgs masses of interest at LHC in the range of 100-150 GeV, the conversions to pairs of fermions represent significant fraction of Higgs decays.

  15. First International Conference on Applications of Photonic Technology (ICAPT'94)

    CERN Document Server

    Chrostowski, Jacek; Measures, Raymond; Applications of Photonic Technology

    1995-01-01

    In this book we present a snapshot of the state of the art in photonics in 1994, showing typical applications and emerging new ones; discussing the key technologies behind these applications, their limitations, and prospects. The articles in this book are extended versions of the papers presented at the first International Conference on Applications ofPhotonic Technology (ICAPT'94), held in Toronto, Canada, on June 21-23, 1994. Photonics has been recognized as one of the key technologies for the 21 st century, as electronics was the technology of the 20th centrury and electrical engineering changed the life of people in the 19th century. According to the recent report of the Organization for Economic Cooperation and Development in Paris (OECD), the market for photonics will grow dramatically in the next 10 years with an expected world-wide expenditure of US $230 billion from some US $30 billion in 1992. The explosion of information technology was the largest driving force for the deployment of photonic techno...

  16. 3rd International Conference on Photonics, Optics and Laser Technology

    CERN Document Server

    Raposo, Maria

    2016-01-01

    The book provides a collection of selected papers presented to the third International Conference on Photonics, Optics and Laser Technology PHOTOPTICS 2015, covering the three main conference scientific areas of “Optics”, “Photonics” and “Lasers”. The selected papers, in two classes full and short, result from a double blind review carried out by the conference program committee members which are highly qualified experts in conference topic areas.

  17. 2nd International Conference on Photonics, Optics and Laser Technology

    CERN Document Server

    Raposo, Maria

    2016-01-01

    This collection of the selected papers presented to the Second International Conference on Photonics, Optics and laser technology PHOTOPTICS 2014 covers the three main conference scientific areas of “Optics”, “Photonics” and “Lasers”. The selected papers, in two classes full and short, result from a double blind review carried out by conference Program Committee members who are highly qualified experts in the conference topic areas.

  18. PHOTON09. Proceedings of the international conference on the structure and interactions of the photon including the 18th international workshop on photon-photon collisions and the international workshop on high energy photon linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Olaf; Diehl, Markus; Schoerner-Sadenius, Thomas; Steinbrueck, Georg (eds.)

    2010-01-15

    The following topics were dealt with: Electroweak and new physics, photon-collider technology, low-energy photon experiments, prompt photons, photon structure, jets and heavy flavours, vacuum polarization and light-by-light scattering, small-x processes, diffraction, total cross sections, exclusive channels and resonances, photons in astroparticle physics. (HSI)

  19. Coupling single emitters to quantum plasmonic circuits

    DEFF Research Database (Denmark)

    Huck, Alexander; Andersen, Ulrik Lund

    2016-01-01

    In recent years, the controlled coupling of single-photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic nonlinearity on a nanoscaled platform. In this article, we will review the recent progress on coupling single emitters...

  20. γ-H2AX Kinetic Profile in Mouse Lymphocytes Exposed to the Internal Emitters Cesium-137 and Strontium-90.

    Directory of Open Access Journals (Sweden)

    Helen C Turner

    Full Text Available In the event of a dirty bomb scenario or an industrial nuclear accident, a significant dose of volatile radionuclides such as 137Cs and 90Sr may be dispersed into the atmosphere as a component of fallout and inhaled or ingested by hundreds and thousands of people. To study the effects of prolonged exposure to ingested radionuclides, we have performed long-term (30 day internal-emitter mouse irradiations using soluble-injected 137CsCl and 90SrCl2 radioisotopes. The effect of ionizing radiation on the induction and repair of DNA double strand breaks (DSBs in peripheral mouse lymphocytes in vivo was determined using the γ-H2AX biodosimetry marker. Using a serial sacrifice experimental design, whole-body radiation absorbed doses for 137Cs (0 to 10 Gy and 90Sr (0 to 49 Gy were delivered over 30 days following exposure to each radionuclide. The committed absorbed doses of the two internal emitters as a function of time post exposure were calculated based on their retention parameters and their derived dose coefficients for each specific sacrifice time. In order to measure the kinetic profile for γ-H2AX, peripheral blood samples were drawn at 5 specific timed dose points over the 30-day study period and the total γ-H2AX nuclear fluorescence per lymphocyte was determined using image analysis software. A key finding was that a significant γ-H2AX signal was observed in vivo several weeks after a single radionuclide exposure. A mechanistically-motivated model was used to analyze the temporal kinetics of γ-H2AX fluorescence. Exposure to either radionuclide showed two peaks of γ-H2AX: one within the first week, which may represent the death of mature, differentiated lymphocytes, and the second at approximately three weeks, which may represent the production of new lymphocytes from damaged progenitor cells. The complexity of the observed responses to internal irradiation is likely caused by the interplay between continual production and repair of DNA

  1. Triggered mesa-top single photon emitter arrays and on-chip integration with dielectric nanoantenna-waveguide systems

    CERN Document Server

    Zhang, Jiefei; Lu, Siyuan; Madhukar, Anupam

    2016-01-01

    Nanophotonic quantum information processing systems require spatially ordered, spectrally uniform single photon sources (SPSs), integrated on-chip with co-designed light manipulating elements providing emission rate enhancement, emitted photon guidance, and lossless propagation. Towards this objective, we introduce and report on systems comprising an SPS array with each SPS surrounded by a dielectric building block (DBB) based multifunctional light manipulation unit (LMU). For the SPS array, we report triggered single photon emission at 77K from GaAs(001)/InGaAs single quantum dots (SQDs) grown selectively on top of nanomesas using the approach of substrate-encoded size-reducing epitaxy (SESRE). Systematic temperature and power dependent photoluminescence (PL), PL excitation, time-resolved PL, and emission statistics studies reveal high spectral uniformity and single photon emission at 77.4K with $g^{(2)}$(0) of 0.24 $\\pm$ 0.07. The SESRE based SPS arrays, following growth of a planarizing overlayer, are read...

  2. Design of main linac emittance tuning bumps for the Compact Linear Collider and the International Linear Collider

    CERN Document Server

    Eliasson, Peder

    2008-01-01

    The installation of elements in the main linac of future linear colliders can only be done with a limited precision. The inevitable misalignments lead to unacceptable emittance growth. Beam-based alignment, e.g., one-to-one correction, dispersion free steering, or ballistic alignment, is necessary to reduce the emittance growth. In some cases, this is, however, not sufficient. For further reduction of the emittance growth, so-called emittance tuning bumps have to be used. A general strategy for the design of emittance tuning bumps has been developed and tested. Simulations suggest that the method can be conveniently used to understand the weaknesses of existing emittance tuning bumps and to significantly improve their performance in terms of, e.g., emittance reduction capability and convergence speed. An example of an application is the design of ten orthogonal knobs that, according to simulations, can reduce the normalized emittance growth in the Compact Linear Collider (CLIC) main linac from 23.8 to 0.34 nm...

  3. Internal quantum efficiency and Auger recombination in green, yellow and red InGaN-based light emitters grown along the polar direction

    Science.gov (United States)

    Ngo, Thi Huong; Gil, Bernard; Damilano, Benjamin; Lekhal, Kaddour; De Mierry, Philippe

    2017-03-01

    We comparatively study the onset of photo-induced non-radiative intrinsic Auger recombination processes for red, yellow and green light emitting InGaNsbnd GaN hetero-structures grown along the polar orientation. We find a dramatic reduction of the photo excitation densities triggering the domination of Auger effect with increasing emission wavelength; that is to say in concert with the enhancement of the internal electric field in the structure. In long wavelength emitters, the internal electric field is stronger, and hence reducing the impact of the internal electric field is more critical.

  4. Internal quantum efficiency mapping analysis for a >20%-efficiency n-type bifacial solar cell with front-side emitter formed by BBr3 thermal diffusion

    Science.gov (United States)

    Simayi, Shalamujiang; Mochizuki, Toshimitsu; Kida, Yasuhiro; Shirasawa, Katsuhiko; Takato, Hidetaka

    2017-10-01

    This paper presents a large-area (239-cm2) high-efficiency n-type bifacial solar cell that is processed using tube-furnace thermal diffusion employing liquid sources BBr3 for the front-side boron emitter and POCl3 for the rear-side phosphorus back surface field (BSF). The SiN x /Al2O3 stack was applied to the front-side boron emitter as a passivation layer. Both the front and rear-side electrodes are obtained using screen-printed contacts with H-patterns. The resulting highest-efficiency solar cell has front- and rear-side efficiencies of 20.3 and 18.7%, respectively, while the corresponding bifaciality is up to 92%. Finally, the passivation quality of the SiN x /Al2O3 stack on the front-side boron emitter and rear-side phosphorus BSF is investigated and visualized by measuring the internal quantum efficiency mapping of the bifacial solar cell.

  5. Combustion powered thermophotovoltaic emitter system

    Energy Technology Data Exchange (ETDEWEB)

    McHenry, R.S. [Naval Academy, Annapolis, MD (United States). Naval Architecture, Ocean and Marine Engineering

    1995-07-01

    The US Naval Academy (USNA) has recently completed an engineering design project for a high temperature thermophotovoltaic (TPV) photon emitter. The final apparatus was to be portable, completely self contained, and was to incorporate cycle efficiency optimization such as exhaust stream recuperation. Through computer modeling and prototype experimentation, a methane fueled emitter system was designed from structural ceramic materials to fulfill the high temperature requirements necessary for high system efficiency. This paper outlines the engineering design process, discusses obstacles and solutions encountered, and presents the final design.

  6. Novel Propagation Properties of Total Internal Reflection Photonic Crystal Fibres with Rhombic Air Holes

    Institute of Scientific and Technical Information of China (English)

    YAN Hai-Feng; YU Zhong-Yuan; LIU Yu-Min; TIAN Hong-Da; HAN Li-Hong

    2011-01-01

    We investigate the propagation properties of a multi-layer photonic crystal fiber with novel rhombic air holes using the finite element method,and calculate the dependence of the propagation properties on the wavelength in the fiber with different geometrical structural parameters,including the internal angle and the external arrangement of the rhombic air holes.Optimizing these parameters,we design a photonic crystal which exhibits both a small dispersion value and low loss near the wavelength of 1.55 μm.Photonic crystal fibers are known as microstructured optical fibers or multi-hole optical fibers,and their cross sections have periodic structures with hollows in the centers due to one or more missing air holes as shown in Fig.1.The light wave can propagate along this hollow structure,which can be considered as the core of the fiber.According to the light-guiding mechanism,there are two types of photonic crystal fibers:total internal reflection photonic crystal fibers and photonic bandgap photonic crystal fibers.[1] The propagation properties of total internal reflection photonic crystal fibers are determined by the arrangements of holes in the transverse field.[1,2] With the flexibility to control the arrangement,size and shape of the air holes,various photonic crystal fibers with different optical properties can be designed as desired.Recently the microstructural design of photonic crystal fibers has drawn extensive attention over the world.[3] As a novel kind of optical fiber,photonic crystal fibers have been widely used for optoelectronic devices.%We investigate the propagation properties of a multi-layer photonic crystal fiber with novel rhombic air holes using the finite element method, and calculate the dependence of the propagation properties on the wavelength in the fiber with different geometrical structural parameters, including the internal angle and the external arrangement of the rhombic air holes. Optimizing these parameters, we design a photonic

  7. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

  8. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    This book covers modern photonics accessibly and discusses the basic physical principles underlying all the applications and technology of photonicsThis volume covers the basic physical principles underlying the technology and all applications of photonics from statistical optics to quantum optics. The topics discussed in this volume are: Photons in perspective; Coherence and Statistical Optics; Complex Light and Singular Optics; Electrodynamics of Dielectric Media; Fast and slow Light; Holography; Multiphoton Processes; Optical Angular Momentum; Optical Forces, Trapping and Manipulation; Pol

  9. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible cov

  10. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying thescience and technology of nanophotonics, its materials andstructures This volume presents nanophotonic structures and Materials.Nanophotonics is photonic science and technology that utilizeslight/matter interactions on the nanoscale where researchers arediscovering new phenomena and developing techniques that go wellbeyond what is possible with conventional photonics andelectronics.The topics discussed in this volume are: CavityPhotonics; Cold Atoms and Bose-Einstein Condensates; Displays;E-paper; Graphene; Integrated Photonics; Liquid Cry

  11. EDITORIAL: Photonica 2011: 3rd International School and Conference on Photonics Photonica 2011: 3rd International School and Conference on Photonics

    Science.gov (United States)

    Petrović, Jovana; Stepić, Milutin; Hadžievski, Ljupčo

    2012-04-01

    Photonics is a rapidly growing discipline of physics that investigates properties of light and its interaction with matter and develops devices based on these properties. Due to both the fundamental and applied nature of photonics research, it pervades many branches of modern technology: quantum mechanics, material science, electronics, telecommunications, biology, medicine, material processing, etc. The borders between these subjects are being erased, generating new research areas such as silicon photonics, biophotonics and quantum photonics. Diverse branches of photonics are united in a common effort to further miniaturize photonic devices, integrate them with existing technologies and develop new technologies. The International School and Conference on Photonics—Photonica—is a biennial forum for the education of young scientists, exchanging new knowledge and ideas, and fostering collaboration between scientists working in photonic science and technology. Conference topics cover a broad range of research activities in optical materials, metamaterials and plasmonics, nonlinear optics, lasers, laser spectroscopy, biophotonics, optoelectronics, optocommunications, photonic crystals, holography, quantum optics and related topics in atomic physics. The aim of the organizers is to provide a platform for discussing new developments, concepts and future trends of various disciplines of photonics by bringing together researchers from academia, government and industrial laboratories. The educational element of Photonica—a series of tutorials and keynote talks—enables students and young researchers to better understand the fundamentals and their use on a route to applications, and informs both young and experienced scientists of new directions of research. The introductory lectures that are directly related to the state-of-the-art are followed by presentations and discussions on recent results during oral and vibrant poster presentations. This Topical Issue is

  12. FOREWORD: International Scientific Seminars on "Fundamental and Applied Problems of Photonics and Condensed Matter Physics"

    Science.gov (United States)

    Yurchenko, Stanislav; Ryzhii, Viktor

    2015-01-01

    International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics'' were held in Bauman Moscow State Technical University (BMSTU) in May - June 2014. The idea of the Seminars was to organize a series of meetings between young scientists and discuss actual problems and the latest results in Photonics and Condensed Matter Physics. There were eight Sessions: Modern Problems of Condensed Matter Physics; Laser Physics; Spectroscopy of Condensed Matter; Terahertz Optical Technology; Optical Signals Processing; Physics of Optical Strong Correlated Systems; Complex Dusty Plasma Physics; Biomediacal Applications of Photonics. Seminars were organized by the young group of scientists and students from Research and Educational Center ''Photonics and Infrared Technology'' at BMSTU. It brought a significant contribution to the development of youth science in the field of Physics and Photonics in Russia. More than 100 young scientists and students participated in the Seminars in spring - summer 2014. The International Scientific Seminars were supported by the Russian Foundation for Basic Research (grant # 14-08-06030-g). This volume contains proceedings of the International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics''. Stanislav Yurchenko and Viktor Ryzhii Bauman Moscow State Technical University

  13. Brownian Emitters

    Science.gov (United States)

    Tsekov, Roumen

    2016-06-01

    A Brownian harmonic oscillator, which dissipates energy either by friction or via emission of electromagnetic radiation, is considered. This Brownian emitter is driven by the surrounding thermo-quantum fluctuations, which are theoretically described by the fluctuation-dissipation theorem. It is shown how the Abraham-Lorentz force leads to dependence of the half-width on the peak frequency of the oscillator amplitude spectral density. It is found that for the case of a charged particle moving in vacuum at zero temperature, its root-mean-square velocity fluctuation is a universal constant, equal to roughly 1/18 of the speed of light. The relevant Fokker-Planck and Smoluchowski equations are also derived.

  14. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  15. Visible Spectrum Incandescent Selective Emitter

    Energy Technology Data Exchange (ETDEWEB)

    Sonsight Inc.

    2004-04-30

    The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination

  16. Coupling single emitters to quantum plasmonic circuits

    Science.gov (United States)

    Huck, Alexander; Andersen, Ulrik L.

    2016-09-01

    In recent years, the controlled coupling of single-photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic nonlinearity on a nanoscaled platform. In this article, we will review the recent progress on coupling single emitters to nanowires towards the construction of a new platform for strong light-matter interaction. The control over such a platform might open new doors for quantum information processing and quantum sensing at the nanoscale and for the study of fundamental physics in the ultrastrong coupling regime.

  17. Coupling single emitters to quantum plasmonic circuits

    CERN Document Server

    Huck, Alexander

    2016-01-01

    In recent years the controlled coupling of single photon emitters to propagating surface plasmons has been intensely studied, which is fueled by the prospect of a giant photonic non-linearity on a nano-scaled platform. In this article we will review the recent progress on coupling single emitters to nano-wires towards the construction of a new platform for strong light-matter interaction. The control over such a platform might open new doors for quantum information processing and quantum sensing at the nanoscale, and for the study of fundamental physics in the ultra-strong coupling regime.

  18. Correlated spontaneous emission of fluorescent emitters mediated by single plasmons

    CERN Document Server

    Bouchet, Dorian; Ithurria, Sandrine; Gulinatti, Angelo; Rech, Ivan; Carminati, Rémi; De Wilde, Yannick; Krachmalnicoff, Valentina

    2016-01-01

    Manipulating the spontaneous emission of a fluorescent emitter can be achieved by placing the emitter in a nanostructured environment. A privileged spot is occupied by plasmonic structures that provide a strong confinement of the electromagnetic field, which results in an enhancement of the emitter-environment interaction. While plasmonic nanostructures have been widely exploited to control the emission properties of single photon emitters, performing the coupling between quantum emitters with plasmons poses a huge challenge. In this Letter we report on a first crucial step towards this goal by the observation of correlated emission between a single CdSe/CdS/ZnS quantum dot exhibiting single photon statistics and a fluorescent nanobead located micrometers apart. This is accomplished by coupling both emitters to a silver nanowire. Single-plasmons are created on the latter from the quantum dot, and transfer energy to excite in turn the fluorescent nanobead.

  19. Metabolomic and lipidomic analysis of serum from mice exposed to an internal emitter, cesium-137, using a shotgun LC-MS(E) approach.

    Science.gov (United States)

    Goudarzi, Maryam; Weber, Waylon M; Mak, Tytus D; Chung, Juijung; Doyle-Eisele, Melanie; Melo, Dunstana R; Brenner, David J; Guilmette, Raymond A; Fornace, Albert J

    2015-01-02

    In this study ultra performance liquid chromatography (UPLC) coupled to time-of-flight mass spectrometry in the MS(E) mode was used for rapid and comprehensive analysis of metabolites in the serum of mice exposed to internal exposure by Cesium-137 ((137)Cs). The effects of exposure to (137)Cs were studied at several time points after injection of (137)CsCl in mice. Over 1800 spectral features were detected in the serum of mice in positive and negative electrospray ionization modes combined. Detailed statistical analysis revealed that several metabolites associated with amino acid metabolism, fatty acid metabolism, and the TCA cycle were significantly perturbed in the serum of (137)Cs-exposed mice compared with that of control mice. While metabolites associated with the TCA cycle and glycolysis increased in their serum abundances, fatty acids such as linoleic acid and palmitic acid were detected at lower levels in serum after (137)Cs exposure. Furthermore, phosphatidylcholines (PCs) were among the most perturbed ions in the serum of (137)Cs-exposed mice. This is the first study on the effects of exposure by an internal emitter in serum using a UPLC-MS(E) approach. The results have put forth a panel of metabolites, which may serve as potential serum markers to (137)Cs exposure.

  20. Emittance Theory for Thin Film Selective Emitter

    Science.gov (United States)

    Chubb, Donald L.; Lowe, Roland A.; Good, Brian S.

    1994-01-01

    Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

  1. Project Adopsys as an example of international collaboration in the field of photonics

    Science.gov (United States)

    Zoric, Nenad; Livshits, Irina; Urbach, Paul

    2015-01-01

    Tendencies of international cooperation in engineering education became very visible during recent years. We demonstrate this statement on one currently running EU project ADOPSYS in the field of optical design, which is an important part of engineering education in photonics. This example shows the importance of the input from different countries and organizations - both from industry and academia. Seven universities and eight optical companies are involved in the project ADOPSYS. Sharing experience of Academia education activity we provide new international type of education "free-of borders". We are going to discuss the key enable technology - PHOTONICS, which is widely used in modern society. Engineering science became very international. For communicating between people from different countries the English language is now used almost exclusively. For a fruitful collaboration between people from different nations, in multi-national projects, tolerance and respect are required between people of different political, cultural, educational backgrounds.

  2. Emittance exchange results

    Energy Technology Data Exchange (ETDEWEB)

    Fliller, R.P., III; /Brookhaven; Koeth, T.; /Rutgers U., Piscataway

    2009-09-01

    The promise of next-generation light sources depends on the availability of ultra-low emittance electron sources. One method of producing low transverse emittance beams is to generate a low longitudinal emittance beam and exchange it with a large transverse emittance. Experiments are underway at Fermilab's A0 Photoinjector and ANL's Argonne Wakefield Accelerator using the exchange scheme of Kim and Sessler. The experiment at the A0 Photoinjector exchanges a large longitudinal emittance with a small transverse emittance. AWA expects to exchange a large transverse emittance with a small longitudinal emittance. In this paper we discuss recent results at A0 and AWA and future plans for these experiments.

  3. Emittance Exchange Results

    Energy Technology Data Exchange (ETDEWEB)

    Fliller III,R.; Koeth, T.

    2009-05-04

    The promise of next-generation light sources depends on the availability of ultra-low emittance electron sources. One method of producing low transverse emittance beams is to generate a low longitudinal emittance beam and exchange it with a large transverse emittance. Experiments are underway at Fermilab's A0 Photoinjector and ANL's Argonne Wakefield Accelerator using the exchange scheme of Kim and Sessler. The experiment at the A0 Photoinjector exchanges a large longitudinal emittance with a small transverse emittance. AWA expects to exchange a large transverse emittance with a small longitudinal emittance. In this paper we discuss recent results at A0 and AWA and future plans for these experiments.

  4. Aberration Corrected Emittance Exchange

    CERN Document Server

    Nanni, Emilio A

    2015-01-01

    Full exploitation of emittance exchange (EEX) requires aberration-free performance of a complex imaging system including active radio-frequency (RF) elements which can add temporal distortions. We investigate the performance of an EEX line where the exchange occurs between two dimensions with normalized emittances which differ by orders of magnitude. The transverse emittance is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. Aberration correction is performed on the four most dominant aberrations. These include temporal aberrations that are corrected with higher order magnetic optical elements located where longitudinal and transverse emittance are coupled. We demonstrate aberration-free performance of emittances differing by 4 orders of magnitude, i.e. an initial transverse emittance of $\\epsilon_x=1$ pm-rad is exchanged with a longitudinal emittance of $\\epsilon_z=10$ nm-rad.

  5. Mesa-top quantum dot single photon emitter arrays: Growth, optical characteristics, and the simulated optical response of integrated dielectric nanoantenna-waveguide systems

    Science.gov (United States)

    Zhang, Jiefei; Chattaraj, Swarnabha; Lu, Siyuan; Madhukar, Anupam

    2016-12-01

    Nanophotonic quantum information processing systems require spatially ordered, spectrally uniform single photon sources (SPSs) integrated on-chip with co-designed light manipulating elements providing emission rate enhancement, emitted photon guidance, and lossless propagation. Towards this goal, we consider systems comprising an SPS array with each SPS coupled to a dielectric building block (DBB) based multifunctional light manipulation unit (LMU). For the SPS array, we report triggered single photon emission from GaAs(001)/InGaAs single quantum dots grown selectively on top of nanomesas using the approach of substrate-encoded size-reducing epitaxy (SESRE). Systematic temperature and power dependent photoluminescence (PL), PL excitation, time-resolved PL, and emission statistics studies reveal high spectral uniformity and single photon emission at 8 K with g(2)(0) of 0.19 ± 0.03. The SESRE based SPS arrays, following growth of a planarizing overlayer, are readily integrable with LMUs fabricated subsequently using either the 2D photonic crystal approach or, as theoretically examined here, DBB based LMUs. We report the simulated optical response of SPS embedded in DBB based nanoantenna-waveguide structures as the multifunctional LMU. The multiple functions of emission rate enhancement, guiding, and lossless propagation are derived from the behavior of the same collective Mie resonance (dominantly magnetic) of the interacting DBB based LMU tuned to the SPS targeted emission wavelength of 980 nm. The simulation utilizes an analytical approach that provides physical insight into the obtained numerical results. Together, the combined experimental and modelling demonstrations open a rich approach to implementing co-designed on-chip integrated SPS-LMUs that, in turn, serve as basic elements of integrated nanophotonic information processing systems.

  6. Total bremsstrahlung spectra of thick lead compounds produced by {sup 90}Sr beta emitter in photon energy region of 10–100 keV

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Suhansar Jit [Department of Physics, B.B.S.B Polytechnic, Fatehgarh Sahib, Punjab (India); Singh, Tajinder, E-mail: tajindersingh2k9@gmail.com [Department of Physics, Mata Gujri College, Fatehgarh Sahib, Punjab (India); Singh, Doordarshi [Department of Mechanical Engineering, B.B.S.B Engineering College, Fatehgarh Sahib, Punjab (India); Singh, Amrit [Department of Physics, Baba Ajay Singh Khalsa College, Gurdas Nangal, Gurdaspur, Punjab (India); Dhaliwal, A.S. [Department of Physics, Sant Longowal Institute of Engineering & Technology, Longowal (Sangrur), Punjab (India)

    2017-06-15

    Highlights: • Total bremsstrahlung spectra in thick targets of Pb compounds by {sup 90}Sr in energy range 10–100 keV. • Experimental results show better agreement with the model which includes PB in SA up to 30 keV. • At higher photon energy region 30–100 keV the model which describes OB is more accurate. • Experimental results show positive deviations from the entire models at higher energy end spectrum. - Abstract: The total bremsstrahlung spectra in the thick targets of lead acetate trihydrate (Pb(CH{sub 3}COO){sub 2}·3H{sub 2}O), lead nitrate Pb(NO{sub 3}){sub 2} and lead chloride (PbCl{sub 2}) produced by {sup 90}Sr beta particles have been investigated in the photon energy region of 10–100 keV. The experimental bremsstrahlung spectra have been compared with the theoretical models Elwert corrected (non relativistic) Bethe Heitler theory, modified Elwert factor (relativistic) Bethe Heitler theory for ordinary bremsstrahlung and modified Elwert factor (relativistic) Bethe Heitler theory which includes polarization bremsstrahlung in the stripped atom approximation. The experimental results show better agreement with theoretical model that includes polarization bremsstrahlung in stripped approximation in the photon energy region below 30 keV. However, at higher photon energy region 30–100 keV, the theoretical model which describes ordinary bremsstrahlung is more accurate to describe the experimental bremsstrahlung spectra. The experimental results show positive deviations from the entire theoretical models at higher energy end of the spectrum. The results indicate that polarization bremsstrahlung plays important role in the formation of total bremsstrahlung spectra in lead compounds produced by continuous beta particles at low photon energy region of 10–30 keV.

  7. [Low-dose rate brachytherapy with locally integrated beta emitters after internal urethrotomy. A pilot project using an animal model].

    Science.gov (United States)

    Weidlich, P; Adam, C; Sroka, R; Lanzl, I; Assmann, W; Stief, C

    2007-09-01

    The treatment of urethral strictures represents an unsolved urological problem. The effect of a (32)P-coated urethral catheter in the sense of low-dose rate brachytherapy to modulate wound healing will be analyzed in an animal experiment. Unfortunately it is not possible to present any results because this is being studied for the first time and there are no experiences with low-dose rate brachytherapy and this form of application in the lower urinary tract. Furthermore the animal experiment will only start in the near future. Both decade-long experiences with radiotherapy to treat benign diseases and our own results of previous studies in otolaryngology and ophthalmology let us expect a significantly lower formation of urethral strictures after internal urethrotomy. This study will contribute to improving the treatment of urethral strictures as demanded in previous papers.

  8. Vacuum Rabi spectra of a single quantum emitter

    CERN Document Server

    Ota, Yasutomo; Kumagai, Naoto; Iwamoto, Satoshi; Arakawa, Yasuhiko

    2015-01-01

    We report the observation of the vacuum Rabi splitting of a single quantum emitter by measuring its direct spontaneous emission into free space. We used a semiconductor quantum dot inside a photonic crystal nanocavity, in conjunction with an appropriate cavity design and filtering with a polarizer and an aperture, enabling the extraction of the inherently-weak emitter's signal. The emitter's vacuum Rabi spectra exhibit clear differences to those measured by detecting the cavity photon leakage. Moreover, we observed an asymmetric vacuum Rabi spectrum induced by interference between the emitter and cavity detection channels. Our observations lay the groundwork for accessing various cavity quantum electrodynamics phenomena that manifest themselves only in the emitter's direct spontaneous emission.

  9. Properties of nanolasers based on few discrete emitters

    DEFF Research Database (Denmark)

    Lund, Anders Mølbjerg; Nielsen, Per Kær; Lorke, Michael

    2012-01-01

    to a high-Q optical cavity. This system has previously been studied for the one and two emitters case, see e.g. [1, 2]. The emitters and cavity are modelled as two-level systems and a harmonic oscillator, respectively. The coupled system is modelled using the Jaynes-Cummings Hamiltonian and the two......-level systems are pumped incoherently by a rate P. Solutions are found using the corresponding master equation. However, with cavity populations exceeding 100 and several emitters, the dimension of the Hilbert space of the system becomes too large to handle efficiently on a conventional computer. E.g. for four...... emitters and 100 photon states the density matrix has more than 2.5 × 106 elements. We have been able to simplify the problem significantly by adiabatically eliminating the photon-assisted polarizations and the correlations between emitters and cavity [3]. This results in a set of rate equations...

  10. Controlled chemical modification of the internal surface of photonic crystal fibers for application as biosensitive elements

    Science.gov (United States)

    Pidenko, Sergey A.; Burmistrova, Natalia A.; Pidenko, Pavel S.; Shuvalov, Andrey A.; Chibrova, Anastasiya A.; Skibina, Yulia S.; Goryacheva, Irina Y.

    2016-10-01

    Photonic crystal fibers (PCF) are one of the most promising materials for creation of constructive elements for bio-, drug and contaminant sensing based on unique optical properties of the PCF as effective nanosized optical signal collectors. In order to provide efficient and controllable binding of biomolecules, the internal surface of glass hollow core photonic crystal fibers (HC-PCF) has been chemically modified with silanol groups and functionalized with (3-aminopropyl) triethoxysilane (APTES). The shift of local maxima in the HC-PCF transmission spectrum has been selected as a signal for estimating the amount of silanol groups on the HC-PCF inner surface. The relationship between amount of silanol groups on the HC-PCF inner surface and efficiency of following APTES functionalization has been evaluated. Covalent binding of horseradish peroxidase (chosen as a model protein) on functionalized PCF inner surface has been performed successively, thus verifying the possibility of creating a biosensitive element.

  11. Cavity-Enhanced Single-Photon Source Based on the Silicon-Vacancy Center in Diamond

    Science.gov (United States)

    Benedikter, Julia; Kaupp, Hanno; Hümmer, Thomas; Liang, Yuejiang; Bommer, Alexander; Becher, Christoph; Krueger, Anke; Smith, Jason M.; Hänsch, Theodor W.; Hunger, David

    2017-02-01

    Single-photon sources are an integral part of various quantum technologies, and solid-state quantum emitters at room temperature appear to be a promising implementation. We couple the fluorescence of individual silicon-vacancy centers in nanodiamonds to a tunable optical microcavity to demonstrate a single-photon source with high efficiency, increased emission rate, and improved spectral purity compared to the intrinsic emitter properties. We use a fiber-based microcavity with a mode volume as small as 3.4 λ3 and a quality factor of 1.9 ×1 04 and observe an effective Purcell factor of up to 9.2. Furthermore, we study modifications of the internal rate dynamics and propose a rate model that closely agrees with the measurements. We observe lifetime changes of up to 31%, limited by the finite quantum efficiency of the emitters studied here. With improved materials, our achieved parameters predict single-photon rates beyond 1 GHz.

  12. Deterministic coupling of a single silicon-vacancy color center to a photonic crystal cavity in diamond

    CERN Document Server

    Riedrich-Möller, Janine; Pauly, Christoph; Mücklich, Frank; Fischer, Martin; Gsell, Stefan; Schreck, Matthias; Becher, Christoph

    2014-01-01

    Deterministic coupling of single solid-state emitters to nanocavities is the key for integrated quantum information devices. We here fabricate a photonic crystal cavity around a preselected single silicon-vacancy color center in diamond and demonstrate modification of the emitters internal population dynamics and radiative quantum efficiency. The controlled, room-temperature cavity coupling gives rise to a resonant Purcell enhancement of the zero-phonon transition by a factor of 19, coming along with a 2.5-fold reduction of the emitter's lifetime.

  13. Two-dimensionally confined topological edge states in photonic crystals

    Science.gov (United States)

    Barik, Sabyasachi; Miyake, Hirokazu; DeGottardi, Wade; Waks, Edo; Hafezi, Mohammad

    2016-11-01

    We present an all-dielectric photonic crystal structure that supports two-dimensionally confined helical topological edge states. The topological properties of the system are controlled by the crystal parameters. An interface between two regions of differing band topologies gives rise to topological edge states confined in a dielectric slab that propagate around sharp corners without backscattering. Three-dimensional finite-difference time-domain calculations show these edges to be confined in the out-of-plane direction by total internal reflection. Such nanoscale photonic crystal architectures could enable strong interactions between photonic edge states and quantum emitters.

  14. Two-Dimensionally Confined Topological Edge States in Photonic Crystals

    CERN Document Server

    Barik, Sabyasachi; DeGottardi, Wade; Waks, Edo; Hafezi, Mohammad

    2016-01-01

    We present an all-dielectric photonic crystal structure that supports two-dimensionally confined helical topological edge states. The topological properties of the system are controlled by the crystal parameters. An interface between two regions of differing band topologies gives rise to topological edge states confined in a dielectric slab that propagate around sharp corners without backscattering. Three dimensional finite-difference time-domain calculations show these edges to be confined in the out-of-plane direction by total internal reflection. Such nanoscale photonic crystal architectures could enable strong interactions between photonic edge states and quantum emitters.

  15. Inspiration, imagination and implementation: International Year of Light activities of the Photonics Academy of Wales at Bangor (PAWB)

    Science.gov (United States)

    Davies, Ray; Shore, K. Alan

    2016-09-01

    Since the establishment of the Photonics Academy of Wales in 2005, several generations of participants have been encouraged to use their imagination in devising, designing and building novel photonics devices of benefit to society. In pursuing photonics projects within PAWB, the participants have gained a practical proficiency in photonics experimentation and photonics product design. The Photonics Academy of Wales @ Bangor ( PAWB) assumed responsibility for the coordination of a series of events in Wales, UK as part of global activities celebrating 2015 as the International Year of Light. PAWB has worked with several organisations and individuals to devise a programme of events which are focussed on conveying the significance of light and its technologies to a broad swathe of the population. These events take into account the bi-lingual nature of Wales with significant events being delivered in the Welsh language. Arrangement and delivery of the events has largely been undertaken on a voluntary basis albeit with some funding having been obtained from supportive bodies and organisations. The presentation will report on the events which were organised and also will present examples of novel photonics devices developed by students working with PAWB. Being aware of the importance of creating an on-going interest in the topics treated during the International Year of Light, some attention will also be given to legacy activities beyond 2015. A specific concern is the identification of effective mechanisms for engagement with photonics industry.

  16. Assessment of uncertainties in the lung activity measurement of low-energy photon emitters using Monte Carlo simulation of ICRP male thorax voxel phantom.

    Science.gov (United States)

    Nadar, M Y; Akar, D K; Rao, D D; Kulkarni, M S; Pradeepkumar, K S

    2015-12-01

    Assessment of intake due to long-lived actinides by inhalation pathway is carried out by lung monitoring of the radiation workers inside totally shielded steel room using sensitive detection systems such as Phoswich and an array of HPGe detectors. In this paper, uncertainties in the lung activity estimation due to positional errors, chest wall thickness (CWT) and detector background variation are evaluated. First, calibration factors (CFs) of Phoswich and an array of three HPGe detectors are estimated by incorporating ICRP male thorax voxel phantom and detectors in Monte Carlo code 'FLUKA'. CFs are estimated for the uniform source distribution in lungs of the phantom for various photon energies. The variation in the CFs for positional errors of ±0.5, 1 and 1.5 cm in horizontal and vertical direction along the chest are studied. The positional errors are also evaluated by resizing the voxel phantom. Combined uncertainties are estimated at different energies using the uncertainties due to CWT, detector positioning, detector background variation of an uncontaminated adult person and counting statistics in the form of scattering factors (SFs). SFs are found to decrease with increase in energy. With HPGe array, highest SF of 1.84 is found at 18 keV. It reduces to 1.36 at 238 keV. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Programmable Quantum Photonic Processor Using Silicon Photonics

    Science.gov (United States)

    2017-04-01

    carbon nanotubes , as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. The...demonstrations, we leveraged an advanced silicon photonics foundry process (OPSIS) to integrate spectral stabilization and filtering of the pump field ...and ballistic quantum computing. Single photon sources based on atomic emitters have improved greatly over recent years -- for example, emission from

  18. Nanocomposite plasmonic fluorescence emitters with core/shell configurations

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Xiaoyu; Brener, Igal; Luk, Ting Shan

    2010-07-16

    This paper is focused on the optical properties of nanocomposite plasmonic emitters with core/shell configurations, where a fluorescence emitter is located inside a metal nanoshell. Systematic theoretical investigations are presented for the influence of material type, core radius, shell thickness, and excitation wavelength on the internal optical intensity, radiative quantum yield, and fluorescence enhancement of the nanocomposite emitter. It is our conclusion that: (i) an optimal ratio between the core radius and shell thickness is required to maximize the absorption rate of fluorescence emitters, and (ii) a large core radius is desired to minimize the non-radiative damping and avoid significant quantum yield degradation of light emitters. Several experimental approaches to synthesize these nanocomposite emitters are also discussed. Furthermore, our theoretical results are successfully used to explain several reported experimental observations and should prove useful for designing ultra-bright core/shell nanocomposite emitters.

  19. Nanocomposite plasmonic fluorescence emitters with core/shell configurations.

    Energy Technology Data Exchange (ETDEWEB)

    Brener, Igal; Luk, Ting Shan; Miao, Xiaoyu

    2010-06-01

    This paper is focused on the optical properties of nanocomposite plasmonic emitters with core/shell configurations, where a fluorescence emitter is located inside a metal nanoshell. Systematic theoretical investigations are presented for the influence of material type, core radius, shell thickness, and excitation wavelength on the internal optical intensity, radiative quantum yield, and fluorescence enhancement of the nanocomposite emitter. It is our conclusion that: (i) an optimal ratio between the core radius and shell thickness is required to maximize the absorption rate of fluorescence emitters, and (ii) a large core radius is desired to minimize the non-radiative damping and avoid significant quantum yield degradation of light emitters. Several experimental approaches to synthesize these nanocomposite emitters are also discussed. Furthermore, our theoretical results are successfully used to explain several reported experimental observations and should prove useful for designing ultra-bright core/shell nanocomposite emitters.

  20. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1988-07-01

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  1. MONTE CARLO SIMULATION OF THE BREMSSTRAHLUNG RADIATION FOR THE MEASUREMENT OF AN INTERNAL CONTAMINATION WITH PURE-BETA EMITTERS IN VIVO.

    Science.gov (United States)

    Fantínová, K; Fojtík, P; Malátová, I

    2016-09-01

    Rapid measurement techniques are required for a large-scale emergency monitoring of people. In vivo measurement of the bremsstrahlung radiation produced by incorporated pure-beta emitters can offer a rapid technique for the determination of such radionuclides in the human body. This work presents a method for the calibration of spectrometers, based on the use of UPh-02T (so-called IGOR) phantom and specific (90)Sr/(90)Y sources, which can account for recent as well as previous contaminations. The process of the whole- and partial-body counter calibration in combination with application of a Monte Carlo code offers readily extension also to other pure-beta emitters and various exposure scenarios. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Alpha particle emitters in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ({sup 211}At) and natural bismuth-212 ({sup 212}Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ({sup 223}Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs.

  3. PREFACE: XXVIII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2013)

    Science.gov (United States)

    Xiao, Guoqing; Cai, Xiaohong; Ding, Dajun; Ma, Xinwen; Zhao, Yongtao

    2014-04-01

    The 28th International Conference on Photonic, Electronic and Atomic Collisions (XXVIII ICPEAC) was held by the Institute of Modern Physics, Chinese Academy of Sciences (IMP) on 24-30 July, 2013 in Lanzhou, China. The 444 conference participants came from 37 countries and/or regions. Five plenary lectures, more than 80 progress reports and special reports had been arranged according to the decision of the ICPEAC International General Committee. Meanwhile, more than 650 abstracts were selected as poster presentations. Before the conference, three highly distinguished scientists, Professor Joachim Burgdöorfer, Professor Hossein Sadeghpour and Professor Yasunori Yamazaki, presented tutorial lectures with the support of the IMP Branch of Youth Innovation Promotion Association, CAS (IMP-YIPA). During the conference, Professor Jianwei Pan from University of Sciences and Technology in China presented an enlightening public lecture on quantum communication. Furthermore, 2013 IUPAP Young Scientist Prize was awarded to Dr T Jahnke from Johann Wolfgang Goethe University of Germany. The Sheldon Datz Prize for an Outstanding Young Scientist Attending ICPEAC was awarded to Dr Diogo Almeida from University of Fribourg of Switzerland. As a biannual academic conference, ICPEAC is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, atomic, ionic, molecular, cluster collisions with matter. With a history back to 1958, ICPEAC came to China for the very first time. IMP has been preparing the conference six years before, ever since the ICPEAC International General Committee made the decision to hold the XXVIII ICPEAC in Lanzhou. This proceedings includes the papers of the two plenary lectures, 40 progress reports, 17 special reports and 337 posters, which were reviewed and revised according to the comments of the referees. The Local Organizing Committee would like to

  4. The DIORAMA Neutron Emitter

    Energy Technology Data Exchange (ETDEWEB)

    Terry, James Russell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    Emission of neutrons in a given event is modeled by the DioramaEmitterNeutron object, a subclass of the abstract DioramaEmitterModule object. The GenerateEmission method of this object is the entry point for generation of a neutron population for a given event. Shown in table 1, this method requires a number of parameters to be defined in the event definition.

  5. Fully tuneable, Purcell-enhanced solid-state quantum emitters

    Energy Technology Data Exchange (ETDEWEB)

    Petruzzella, M., E-mail: m.petruzzella@tue.nl; Xia, T.; Pagliano, F.; Birindelli, S.; Zobenica, Z.; Fiore, A. [COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, NL-5600MB Eindhoven (Netherlands); Midolo, L. [Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Li, L. H.; Linfield, E. H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-10-05

    We report the full energy control over a semiconductor cavity-emitter system, consisting of single Stark-tunable quantum dots embedded in mechanically reconfigurable photonic crystal membranes. A reversible wavelength tuning of the emitter over 7.5 nm as well as an 8.5 nm mode shift are realized on the same device. Harnessing these two electrical tuning mechanisms, a single exciton transition is brought on resonance with the cavity mode at several wavelengths, demonstrating a ten-fold enhancement of its spontaneous emission. These results open the way to bring several cavity-enhanced emitters mutually into resonance and therefore represent a key step towards scalable quantum photonic circuits featuring multiple sources of indistinguishable single photons.

  6. PREFACE: XXIX International Conference on Photonic, Electronic, and Atomic Collisions (ICPEAC2015)

    Science.gov (United States)

    Díaz, C.; Rabadán, I.; García, G.; Méndez, L.; Martín, F.

    2015-09-01

    The 29th International Conference on Photonic, Electronic and Atomic Collisions (XXIX ICPEAC) was held at the Palacio de Congresos ''El Greco'', Toledo, Spain, on 22-28 July, 2015, and was organized by the Universidad Autónoma de Madrid (UAM) and the Consejo Superior de Investigaciones Científicas (CSIC). ICPEAC is held biannually and is one of the most important international conferences on atomic and molecular physics. The topic of the conference covers the recent progresses in photonic, electronic, and atomic collisions with matter. With a history back to 1958, ICPEAC came to Spain in 2015 for the very first time. UAM and CSIC had been preparing the conference for six years, ever since the ICPEAC International General Committee made the decision to hold the XXIX ICPEAC in Toledo. The conference gathered 670 participants from 52 countries and attracted 854 contributed papers for presentation in poster sessions. Among the latter, 754 are presented in issues 2-12 of this volume of the Journal of Physics Conference Series. In addition, five plenary lectures, including the opening one by the Nobel laureate Prof. Ahmed H. Zewail and the lectures by Prof. Maciej Lewenstein, Prof. Paul Scheier, Prof. Philip H. Bucksbaum, and Prof. Stephen J. Buckman, 62 progress reports and 26 special reports were presented following the decision of the ICPEAC International General Committee. Detailed write-ups of most of the latter are presented in issue 1 of this volume, constituting a comprehensive tangible record of the meeting. On the occasion of the International Year of Light (IYL2015) and with the support of the Fundación Española para la Ciencia y la Tecnología (FECYT), the program was completed with two public lectures delivered by the Nobel laureate Prof. Serge Haroche and the Príncipe de Asturias laureate Prof. Pedro M. Echenique on, respectively, ''Fifty years of laser revolutions in physics'rquot; and ''The sublime usefulness of useless science''. Also a

  7. Quantum-dot emitters in photonic nanostructures

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Stobbe, Søren; Lodahl, Peter

    2010-01-01

    The spontaneous emission from self-assembled semiconductor quantum dots is strongly influenced by the environment in which they are placed. This can be used to determine fundamental optical properties of the quantum dots as well as to manipulate and control the quantum-dot emission itself....

  8. Poster - Thur Eve - 46: The upcoming international code of practice for small static photon field dosimetry.

    Science.gov (United States)

    Palmans, H; Alfonso, R; Andreo, P; Capote, R; Huq, M S; Izewska, J; Johansson, J; Kilby, W; Mackie, T R; Meghzifene, A; Rosser, K; Seuntjens, J; Ullrich, W

    2012-07-01

    The increased use of small photon fields in stereotactic and intensity-modulated radiotherapy has raised the need for standardizing the dosimetry of such fields using procedures consistent with those for conventional radiotherapy. An international working group, established by the IAEA in collaboration with AAPM and IPEM, is finalising a Code of Practice for the dosimetry of small static photon fields. Procedures for reference dosimetry in nonstandard machine specific reference (msr) fields are provided following the formalism of Alfonso et al. (Med. Phys. 35: 5179; 2008). Reference dosimetry using ionization chambers in machines that cannot establish a conventional 10 cm × 10 cm reference field is based on either a direct calibration in the msr field traceable to primary standards, a calibration in a reference field and a generic correction factor or the product of a correction factor for a virtual reference field and a correction factor for the difference between the msr and virtual fields. For the latter method, procedures are provided for determining the beam quality in non-reference conditions. For the measurement of field output factors in small fields, procedures for connecting large field measurements using ionization chambers to small field measurements using high-resolution detectors such as diodes, diamond, liquid ion chambers, organic scintillators and radiochromic film are given. The Code of Practice also presents consensus data on correction factors for use in conjunction with measured, detector-specific output factors. Further research to determine missing data according to the proposed framework will be strongly encouraged by publication of this document. © 2012 American Association of Physicists in Medicine.

  9. 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.

  10. The photonic nanowire: A highly efficient single-photon source

    DEFF Research Database (Denmark)

    Gregersen, Niels

    2014-01-01

    The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency.......The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency....

  11. Single-bunch emittance dilution in the perfect ILC main linac

    Institute of Scientific and Technical Information of China (English)

    WANG Dou; GAO Jie

    2011-01-01

    In the ILC(International Linear Collider)main linac, low emittance preservation is the most important issue for beam dynamics study. As the main sources of emittance dilution, the dispersive and wakefield effects were studied in this paper. The theoretical calculations and numerical simulations of these two effects on single-bunch emittance dilution, without any misalignment errors, are presented in detail.

  12. PREFACE: Proceedings of the International Conference on Optical, Optoelectronic and Photonic Materials and Applications (ICOOPMA) 2014

    Science.gov (United States)

    Sweeney, Stephen J.; Jha, Animesh

    2015-06-01

    Developments in the connected fields of optics, optoelectronics and photonics have had a profound effect on the emergence of modern technologies and their influence on our lives. In all of these fields, understanding and improving the basic underlying materials is of crucial importance for the development of systems and applications. The International Conference on Optical, Optoelectronic and Photonic Materials and Applications (ICOOPMA) has successfully married these fields and become a regular feature in the conference calendar. The 6th conference in the series, held at the University of Leeds from 27th July - 1st August, 2014, continued the ICOOPMA tradition and attracted 220 international delegates with a diverse range of disciplines and interests. The 59 papers in this Proceedings provide an excellent overview of the topics presented. The conference consisted of four thematic areas in the fields of inorganic semiconductors, carbon and polymeric materials, inorganic glasses and crystalline materials, and metamaterials and plasmonics where each theme area included research on basic materials through to device applications. The conference began with a Workshop organised by Professor Dan Hewak (University of Southampton) with speakers covering Organic Optoelectronic Complexes (Dr Richard Curry, University of Surrey), Metamaterials (Dr Vassili Fedotov, University of Southampton), Graphene (Dr Monica Craciun, University of Exeter) and Amorphous Semiconductors (Dr Jiri Orava, University of Cambridge and Tohoku University). This provided an excellent overview of a representative range of the important topics that were discussed further at the conference. The conference included a banquet which successfully combined excellent food with a relaxing opportunity for the conference delegates to socialise and network. The pinnacle of the evening was the after dinner speech given by our distinguished guest, Professor Sir David Payne (University of Southampton), who gave a

  13. Single photon delayed feedback: a way to stabilize intrinsic quantum cavity electrodynamics.

    Science.gov (United States)

    Carmele, Alexander; Kabuss, Julia; Schulze, Franz; Reitzenstein, Stephan; Knorr, Andreas

    2013-01-01

    We propose a scheme to control cavity quantum electrodynamics in the single photon limit by delayed feedback. In our approach a single emitter-cavity system, operating in the weak coupling limit, can be driven into the strong coupling-type regime by an external mirror: The external loop produces Rabi oscillations directly connected to the electron-photon coupling strength. As an expansion of typical cavity quantum electrodynamics, we treat the quantum correlation of external and internal light modes dynamically and demonstrate a possible way to implement a fully quantum mechanical time-delayed feedback. Our theoretical approach proposes a way to experimentally feedback control quantum correlations in the single photon limit.

  14. Quantum dot resonant tunneling diode single photon detector with aluminum oxide aperture defined tunneling area

    DEFF Research Database (Denmark)

    Li, H.W.; Kardynal, Beata; Ellis, D.J.P.

    2008-01-01

    Quantum dot resonant tunneling diode single photon detector with independently defined absorption and sensing areas is demonstrated. The device, in which the tunneling is constricted to an aperture in an insulating layer in the emitter, shows electrical characteristics typical of high quality...... resonant tunneling diodes. A single photon detection efficiency of 2.1%+/- 0.1% at 685 nm was measured corresponding to an internal quantum efficiency of 14%. The devices are simple to fabricate, robust, and show promise for large absorption area single photon detectors based on quantum dot structures....

  15. WIMP search in the mono-photon channel at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Habermehl, Moritz [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2016-07-01

    The International Linear Collider (ILC) is a planned electron-positron collider with √(s) tunable from 250 to 500 GeV, with a possible upgrade to 1 TeV. Besides precision measurements of the Higgs boson its physics goals comprise searches for physics beyond the Standard Model, e.g. searches for Dark Matter. This collider search assumes the production of WIMPs in pairs. They are not visible in the detector but the energy carried away can be observed via an additional (''tag'') particle. Photon emission from the initial state leads to the almost model independent signature: e{sup +}e{sup -} → χχγ. As this analysis tests couplings between WIMPs and leptons it is complementary to analogues searches at the LHC. A precise study is facilitated by the clean environment of lepton colliders with small systematics of electroweak backgrounds. While the conceptual feasibility and the sensitivity reach of the ILC have been shown in the past, this talk focusses on the consequences for the detector design. The requirements for the central detector as well as for the instrumentation of the forward region are discussed in the context of the ILD detector concept.

  16. Scanning Emitter Lifetime Imaging Microscopy for Spontaneous Emission Control

    DEFF Research Database (Denmark)

    Frimmer, Martin; Chen, Yuntian; Koenderink, A. Femius

    2011-01-01

    We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nanophotonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment while...

  17. Photon Factory Activity Report, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Photon Factory Activity Report no.12 deals with our activities in the period from October 1993 through September 1994. We operate two light sources at the Photon Factory; the 2.5-GeV Photon Factory storage ring, which is a dedicated light source, and the 6.5-GeV TRISTAN Accumulation Ring, which is parasitically used as a light source. We keep more than seventy experimental stations at two facilities, and accept experiments primarily according to approval by the Program Advisory Committee. The number of proposals to the Photon Factory has been still growing. Three-hundred eighty two proposals were approved by the PAC in FY1994, which is an increase by thirteen percent compared to the previous year. Remarkable was growth in biology proposals, particularly proposals in protein crystallography. In FY 1994, we accepted approximately 20,000 man-days as general users, and almost ten percent of them were from abroad. We always open the facility to users, not only domestic but also international. Recently we have been concentrating our effort to upgrading of the light sources and reconstruction of the experimental stations to keep the Photon Factory an attractive research facility in the forthcoming years. We have already started a program of reducing the emittance of the 2.5-GeV storage ring, which now operates with an emittance of 110 nm-rad, to 27 nm-rad by modifying the lattice, with the goal of operation at the reduced emittance in the fall of 1997. We also have conceived of a conversion of the TRISTAN Accumulation Ring to a dedicated light source of high energies. The on-going TRISTAN project will terminate by the end of 1995, and the TRISTAN Main Ring will be converted to a new B-Factory. At this moment, the TRISTAN Accumulation Ring will be disused as the injector to the Main Ring, and conversion of the AR to a dedicated light source becomes possible. (J.P.N.)

  18. Nonblinking Emitters with Nearly Lifetime-Limited Linewidths in CVD Nanodiamonds

    Science.gov (United States)

    Li, Ke; Zhou, Yu; Rasmita, A.; Aharonovich, I.; Gao, W. B.

    2016-08-01

    Near transform-limited single-photon sources are required for perfect photon indistinguishability in quantum networks. Having such sources in nanodiamonds is particularly important since it can enable engineering hybrid quantum-photonic systems. In this paper, we report the generation of optically stable, nearly transform-limited single silicon-vacancy emitters in nanodiamonds. Lines as narrow as 325 MHz are reported, which is close to the lifetime-limited linewidth (141 MHz). Moreover, the emitters exhibit minimal spectrum diffusion and high photostability, even if pumped well above saturation. Our results suggest that nanodiamonds can host color centers with superior properties suitable for hybrid photonic devices and quantum information.

  19. Spectral beam combining of multi-single emitters

    Science.gov (United States)

    Wang, Baohua; Guo, Weirong; Guo, Zhijie; Xu, Dan; Zhu, Jing; Zhang, Qiang; Yang, Thomas; Chen, Xiaohua

    2016-03-01

    Spectral beam combination expands the output power while keeps the beam quality of the combined beam almost the same as that of a single emitter. Spectral beam combination has been successfully achieved for high power fiber lasers, diode laser arrays and diode laser stacks. We have recently achieved the spectral beam combination of multiple single emitter diode lasers. Spatial beam combination and beam transformation are employed before beams from 25 single emitter diode lasers can be spectrally combined. An average output power about 220W, a spectral bandwidth less than 9 nm (95% energy), a beam quality similar to that of a single emitter and electro-optical conversion efficiency over 46% are achieved. In this paper, Rigorous Coupled Wave analysis is used to numerically evaluate the influence of emitter width, emitter pitch and focal length of transform lens on diffraction efficiency of the grating and spectral bandwidth. To assess the chance of catastrophic optical mirror damage (COMD), the optical power in the internal cavity of a free running emitter and the optical power in the grating external cavity of a wavelength locked emitter are theoretically analyzed. Advantages and disadvantages of spectral beam combination are concluded.

  20. 1979 international symposium on lepton and photon interactions at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, T.B.W.; Abarbanel, H.D.I.

    1979-01-01

    This symposium on Leptons and Photons is ninth in the series of biannual meetings which began at Cambridge, Massachusetts, in 1963. Abstracts of individual items from the symposium were prepared separately for the data base. (GHT)

  1. Carbon Nanotube Field Emitters

    OpenAIRE

    Zhbanov, Alexander; Pogorelov, Evgeny; Chang, Yia-Chung

    2010-01-01

    In this chapter we theoretically investigate the field emission from carbon nanotube field emitters in diode configuration between a flat anode and cathode. Exact analytical formulas of the electrical field, field enhancement factor, ponderomotive force, and field emission current are found. Applied voltage, height of the needle, radius of curvature on its top, and the work function are the parameters at our disposal. The field enhancement factor, total force and emission current, as well as ...

  2. Tunable narrow band source via the strong coupling between optical emitter and nanowire surface plasmons

    CERN Document Server

    Yang, J; Niu, Y P; Qi, Y H; Zhou, F X; Gong, S Q

    2014-01-01

    The spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two-level emitter coupled to the propagating surface plasmon. But the width can not be narrowed any further because of the loss of the photon out of system by spontaneous emission from the emitter. Here we propose a new scheme to construct a narrow-band source via a one-dimensional waveguide coupling with a three-level emitter. It is shown that the reflective spectrum width can be narrowed avoiding the impact of the loss. This approach opens up the possibility of plasmonic ultranarrow single-photon source.

  3. Deterministic strain-induced arrays of quantum emitters in a two-dimensional semiconductor

    Science.gov (United States)

    Branny, Artur; Kumar, Santosh; Proux, Raphaël; Gerardot, Brian D

    2017-01-01

    An outstanding challenge in quantum photonics is scalability, which requires positioning of single quantum emitters in a deterministic fashion. Site positioning progress has been made in established platforms including defects in diamond and self-assembled quantum dots, albeit often with compromised coherence and optical quality. The emergence of single quantum emitters in layered transition metal dichalcogenide semiconductors offers new opportunities to construct a scalable quantum architecture. Here, using nanoscale strain engineering, we deterministically achieve a two-dimensional lattice of quantum emitters in an atomically thin semiconductor. We create point-like strain perturbations in mono- and bi-layer WSe2 which locally modify the band-gap, leading to efficient funnelling of excitons towards isolated strain-tuned quantum emitters that exhibit high-purity single photon emission. We achieve near unity emitter creation probability and a mean positioning accuracy of 120±32 nm, which may be improved with further optimization of the nanopillar dimensions. PMID:28530219

  4. Deterministic strain-induced arrays of quantum emitters in a two-dimensional semiconductor

    Science.gov (United States)

    Branny, Artur; Kumar, Santosh; Proux, Raphaël; Gerardot, Brian D.

    2017-05-01

    An outstanding challenge in quantum photonics is scalability, which requires positioning of single quantum emitters in a deterministic fashion. Site positioning progress has been made in established platforms including defects in diamond and self-assembled quantum dots, albeit often with compromised coherence and optical quality. The emergence of single quantum emitters in layered transition metal dichalcogenide semiconductors offers new opportunities to construct a scalable quantum architecture. Here, using nanoscale strain engineering, we deterministically achieve a two-dimensional lattice of quantum emitters in an atomically thin semiconductor. We create point-like strain perturbations in mono- and bi-layer WSe2 which locally modify the band-gap, leading to efficient funnelling of excitons towards isolated strain-tuned quantum emitters that exhibit high-purity single photon emission. We achieve near unity emitter creation probability and a mean positioning accuracy of 120+/-32 nm, which may be improved with further optimization of the nanopillar dimensions.

  5. On the similarity of particle and photon tunneling and multiple internal reflections in one-dimensional, two-dimensional and three-dimensional photon tunneling

    Science.gov (United States)

    Olkhovsky, V. S.

    2014-05-01

    The formal mathematical analogy between time-dependent quantum equation for the nonrelativistic particles and time-dependent equation for the propagation of electromagnetic waves had been studied in [A. I. Akhiezer and V. B. Berestezki, Quantum Electrodynamics (FM, Moscow, 1959) [in Russian] and S. Schweber, An Introduction to Relativistic Quantum Field Theory, Chap. 5.3 (Row, Peterson & Co, Ill, 1961)]. Here, we deal with the time-dependent Schrödinger equation for nonrelativistic particles and with time-dependent Helmholtz equation for electromagnetic waves. Then, using this similarity, the tunneling and multiple internal reflections in one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) particle and photon tunneling are studied. Finally, some conclusions and future perspectives for further investigations are presented.

  6. Electrical control of optical emitter relaxation pathways enabled by graphene

    Science.gov (United States)

    Tielrooij, K. J.; Orona, L.; Ferrier, A.; Badioli, M.; Navickaite, G.; Coop, S.; Nanot, S.; Kalinic, B.; Cesca, T.; Gaudreau, L.; Ma, Q.; Centeno, A.; Pesquera, A.; Zurutuza, A.; de Riedmatten, H.; Goldner, P.; García de Abajo, F. J.; Jarillo-Herrero, P.; Koppens, F. H. L.

    2015-03-01

    Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of fundamental interest and has many applications in the fields of quantum optics, photovoltaics, photodetection, biosensing and light emission. Advanced dielectric, semiconductor and metallic systems have been developed to tailor the interaction between an emitter and its environment. However, active control of the energy flow from an emitter into optical, electronic or plasmonic excitations has remained challenging. Here, we demonstrate in situ electrical control of the relaxation pathways of excited erbium ions, which emit light at the technologically relevant telecommunication wavelength of 1.5 μm. By placing the erbium at a few nanometres distance from graphene, we modify the relaxation rate by more than a factor of three, and control whether the emitter decays into electron-hole pairs, emitted photons or graphene near-infrared plasmons, confined to control of the local density of optical states constitute a new paradigm for active (quantum) photonics and can be applied using any combination of light emitters and two-dimensional materials.

  7. Study of Lower Emittance Lattices for SPEAR3

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaobiao; Nosochkov, Yuri; Safranek, James A.; Wang, Lanfa; /SLAC

    2011-11-08

    We study paths to significantly reduce the emittance of the SPEAR3 storage ring. Lattice possibilities are explored with the GLASS technique. New lattices are designed and optimized for practical dynamic aperture and beam lifetime. Various techniques are employed to optimize the nonlinear dynamics, including the Elegant-based genetic algorithm. Experimental studies are also carried out on the ring to validate the lattice design. The SPEAR3 storage ring is a third generation light source which has a racetrack layout with a circumference of 234.1 m. The requirement to maintain the photon beamline positions put a significant constraint on the lattice design. Consequently the emittance of SPEAR3 is not on par with some of the recently-built third generation light sources. The present operational lattice has an emittance of 10 nm. For the photon beam brightness of SSRL to remain competitive among the new or upgraded ring-based light sources, it is necessary to significantly reduce the emittance of SPEAR3. In this paper we report our ongoing effort to develop a lower emittance solution for SSRL. We first show the potential of the SPEAR3 lattice with results of the standard cell study using the GLASS technique. This is followed by a discussion of the design strategy for full-ring linear lattices. Several lattice options are compared. We then show the methods and results for dynamic aperture optimization. Experiments were also conducted on the SPEAR3 ring to implement the lattice and to measure the key lattice parameters.

  8. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  9. PREFACE: XXVII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011)

    Science.gov (United States)

    Williams, I. D.; van der Hart, H. W.; McCann, J. F.; Crothers, D. S. F.

    2012-11-01

    The XXVII International Conference on Photonic, Electronic and Atomic Collisions was held at Queen's University Belfast, Northern Ireland, 27 July - 2 August 2011. Members of the Local Organising Committee were drawn from the School of Mathematics and Physics of Queen's University Belfast, the School of Physical Sciences at Dublin City University, the School of Physics at University College Dublin and the Department of Experimental Physics at the National University of Ireland, Maynooth. The Conference was attended by 566 participants with contributions from 54 countries. The meeting attracted 786 contributed papers for presentation in the poster sessions. The conference included 20 Special Reports selected from the contributed papers, and these are included in part 1 of this volume. During the meeting a total of 65 Progress Reports were also presented, and the authors invited to submit written versions of their talks (see Part 1). Of the total number of contributed papers, 663 are included as refereed abstracts in parts 2 to 15 of this volume of Journal of Physics: Conference Series. Part 1 of this volume includes detailed write-ups of the majority of plenary lectures, progress reports and special reports, constituting a comprehensive tangible record of the meeting, and is additionally published in hard-copy as the Conference Proceedings. There were 5 plenary lectures given by Margaret Murnane on Ultrafast processes in atomic dynamics; Chris Greene on Few-body highly-correlated dynamics; Michael Allan on Electron-molecule collisions; Yasunori Yamazaki on Antiproton and positron collisions and Thomas Stöhlker on Relativistic ion collisions. Ian Spielman, winner of the IUPAP Young Scientist Prize for 2011, gave a special lecture entitled Modifying interatomic interactions using Raman coupling: a tale of slowly colliding Bose-Einstein condensates. In addition an evening public lecture by Mike Baillie on How precise tree-ring dating raises issues concerning the

  10. Waveguide coupled resonance fluorescence from on-chip quantum emitter.

    Science.gov (United States)

    Makhonin, Maxim N; Dixon, James E; Coles, Rikki J; Royall, Ben; Luxmoore, Isaac J; Clarke, Edmund; Hugues, Maxime; Skolnick, Maurice S; Fox, A Mark

    2014-12-10

    Resonantly driven quantum emitters offer a very promising route to obtain highly coherent sources of single photons required for applications in quantum information processing (QIP). Realizing this for on-chip scalable devices would be important for scientific advances and practical applications in the field of integrated quantum optics. Here we report on-chip quantum dot (QD) resonance fluorescence (RF) efficiently coupled into a single-mode waveguide, a key component of a photonic integrated circuit, with a negligible resonant laser background and show that the QD coherence is enhanced by more than a factor of 4 compared to off-resonant excitation. Single-photon behavior is confirmed under resonant excitation, and fast fluctuating charge dynamics are revealed in autocorrelation g((2)) measurements. The potential for triggered operation is verified in pulsed RF. These results pave the way to a novel class of integrated quantum-optical devices for on-chip quantum information processing with embedded resonantly driven quantum emitters.

  11. Nanowire-based Quantum Photonics

    NARCIS (Netherlands)

    Bulgarini, G.

    2014-01-01

    In this thesis work, I studied individual quantum dots embedded in one-dimensional nanostructures called nanowires. Amongst the effects given by the nanometric dimensions, quantum dots enable the generation of single light particles: photons. Single photon emitters and detectors are central building

  12. Efficient room-temperature source of polarized single photons

    Science.gov (United States)

    Lukishova, Svetlana G.; Boyd, Robert W.; Stroud, Carlos R.

    2007-08-07

    An efficient technique for producing deterministically polarized single photons uses liquid-crystal hosts of either monomeric or oligomeric/polymeric form to preferentially align the single emitters for maximum excitation efficiency. Deterministic molecular alignment also provides deterministically polarized output photons; using planar-aligned cholesteric liquid crystal hosts as 1-D photonic-band-gap microcavities tunable to the emitter fluorescence band to increase source efficiency, using liquid crystal technology to prevent emitter bleaching. Emitters comprise soluble dyes, inorganic nanocrystals or trivalent rare-earth chelates.

  13. International Conference on Applications of Photonic Technology, Communications, Sensing, Materials and Signal Processing

    CERN Document Server

    Lessard, Roger; ICAPT '96; Applications of photonic technology 2

    1997-01-01

    This book presents a current review ofphotonic technologies and their applications. The papers published in this book are extended versions of the papers presented at the Inter­ national Conference on Applications ofPhotonic Technology (ICAPT'96) held in Montreal, Canada, on July 29 to August 1, 1996. The theme of this event was "Closing the Gap Between Theory, Developments and Applications. " The term photonics covers both optics and optical engineering areas of growing sci­ entific and commercial importance throughout the world. It is estimated that photonic tech­ nology-related applications to increase exponentially over the next few years and will play a significant role in the global economy by reaching a quarter of a trillion of US dollars by the year 2000. The global interest and advancements of this technology are represented in this book, where leading scientists of twenty-two countries with advanced technology in photon­ ics present their latest results. The papers selected herein are ...

  14. Low-emittance tuning at the Cornell Electron Storage Ring

    CERN Document Server

    Shanks, James; Sagan, David

    2013-01-01

    In 2008 the Cornell Electron/Positron Storage Ring (CESR) was reconfigured from an electron/positron collider to serve as a testbed for the International Linear Collider (ILC) damping rings. One of the primary goals of the CESR Test Accelerator (CesrTA) project is to develop low emittance tuning techniques to achieve sub-10pm geometric vertical emittance at 2.085 GeV. This paper discusses the tuning methods used at CesrTA to achieve low-emittance conditions. A minimum vertical emittance of 8.7 +2.9/-3.4(sys) +/-0.2(stat) pm has been achieved at 2.085 GeV. In various configurations and beam energies the correction technique routinely achieves vertical emittance <15 pm after correction. Beam-based measurement and correction requires about 15 minutes. Simulations modeling the effects of magnet misalignments, BPM errors, and emittance correction algorithm suggest the residual vertical emittance measured at the conclusion of the tuning procedure is dominated by sources other than optics errors and misalignments...

  15. Evaluation of dual energy quantitative CT for determining the spatial distributions of red marrow and bone for dosimetry in internal emitter radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Goodsitt, Mitchell M., E-mail: goodsitt@umich.edu; Shenoy, Apeksha; Howard, David; Christodoulou, Emmanuel; Dewaraja, Yuni K. [Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Shen, Jincheng [Department of Biostatistics, University of Michigan, 1415 Washington Heights, Ann Arbor, Michigan 48109 (United States); Schipper, Matthew J. [Department of Radiation Oncology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Wilderman, Scott [Department of Nuclear Engineering, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Chun, Se Young [Ulsan National Institute of Science and Technology (UNIST), School of Electrical and Computer Engineering, Ulsan 689-798 (Korea, Republic of)

    2014-05-15

    Purpose: To evaluate a three-equation three-unknown dual-energy quantitative CT (DEQCT) technique for determining region specific variations in bone spongiosa composition for improved red marrow dose estimation in radionuclide therapy. Methods: The DEQCT method was applied to 80/140 kVp images of patient-simulating lumbar sectional body phantoms of three sizes (small, medium, and large). External calibration rods of bone, red marrow, and fat-simulating materials were placed beneath the body phantoms. Similar internal calibration inserts were placed at vertebral locations within the body phantoms. Six test inserts of known volume fractions of bone, fat, and red marrow were also scanned. External-to-internal calibration correction factors were derived. The effects of body phantom size, radiation dose, spongiosa region segmentation granularity [single (∼17 × 17 mm) region of interest (ROI), 2 × 2, and 3 × 3 segmentation of that single ROI], and calibration method on the accuracy of the calculated volume fractions of red marrow (cellularity) and trabecular bone were evaluated. Results: For standard low dose DEQCT x-ray technique factors and the internal calibration method, the RMS errors of the estimated volume fractions of red marrow of the test inserts were 1.2–1.3 times greater in the medium body than in the small body phantom and 1.3–1.5 times greater in the large body than in the small body phantom. RMS errors of the calculated volume fractions of red marrow within 2 × 2 segmented subregions of the ROIs were 1.6–1.9 times greater than for no segmentation, and RMS errors for 3 × 3 segmented subregions were 2.3–2.7 times greater than those for no segmentation. Increasing the dose by a factor of 2 reduced the RMS errors of all constituent volume fractions by an average factor of 1.40 ± 0.29 for all segmentation schemes and body phantom sizes; increasing the dose by a factor of 4 reduced those RMS errors by an average factor of 1.71 ± 0.25. Results

  16. Hafnia-plugged microcavities for thermal stability of selective emitters

    Science.gov (United States)

    Lee, Heon-Ju; Smyth, Katherine; Bathurst, Stephen; Chou, Jeffrey; Ghebrebrhan, Michael; Joannopoulos, John; Saka, Nannaji; Kim, Sang-Gook

    2013-06-01

    Two-dimensional arrays of micro-cavities effectively control photon motion and selectively emit radiation tailored to the preferred bandgap of photovoltaic (PV) cells, thus enhancing the efficiency of thermophotovoltaic energy conversion. At the high operating temperatures, however, the micro- and nano-patterned structures of the selective emitters quickly lose their integrity--obliterating the tight tolerances required for precise spectral control. Even if oxidation, recrystallization, and grain growth could be avoided with single-crystal tungsten (W) selective emitters with vacuum packaging, surface diffusion, evaporation, and re-condensation are not avoidable in long-term operation at high temperatures. The concept of a planar array of plugged micro-cavities to suppress the curvature-dependent thermal degradation modes is proposed and tested. Based on scale-accelerated failure tests of silicon devices, the lifetime of W selective emitters operating at 1100 K is estimated to be at least 30 yr.

  17. Emitter Design and Numerical Simulation Based on the Extenics Theory

    Directory of Open Access Journals (Sweden)

    Jiang Fan

    2014-05-01

    Full Text Available In order to improve the performance of emitter, the extenics theory is introduced, whose divergent thinking is used to resolve the conflict of anti-clogging and energy dissipation and a new structure is proposed. The wide triangular areas are designed to reduce the flow rate behind of the each orifice and be easy to precipitation of impurities. The orifices are set to gradually decrease water kinetic energy and the flow channel is designed to be dismantle. The numerical simulation technology is used to analyze the internal flow field of emitter, the flow field results show that the improved emitter has great effect of energy dissipation and anti-clogging. As the same time, the structure of emitter is optimized and L1 = 31 mm, L2 = 21 mm, L3 = 8 mm and L4 = 5 mm are the optimization size values.

  18. Experimental Chiral Dynamics New Opportunities with Polarized Internal Targets and Almost-Real Photon Tagging

    CERN Document Server

    Bernstein, A M

    1998-01-01

    Experiments on pion (Goldstone Boson) photoproduction from the nucleon tests the ability to make QCD predictions at confinement scale energies. Experiments with both polarized beams and targets have the potential sensitivity to demonstrate the dynamic isospin breaking effects of the up and down quark mass difference, whereas experiments on Compton scattering from the nucleon will incisively probe its chiral structure by measuring all of the spin dependent amplitudes. These and other types of photo-induced measurements on nuclei could be possible at BLAST with the addition of an almost-real photon tagging system and a forward low energy recoil ion hodoscope.

  19. Coupling of individual quantum emitters to channel plasmons

    CERN Document Server

    Bermúdez-Ureña, Esteban; Geiselmann, Michael; Marty, Renaud; Radko, Ilya P; Holmgaard, Tobias; Alaverdyan, Yury; Moreno, Esteban; García-Vidal, Francisco J; Bozhevolnyi, Sergey I; Quidant, Romain

    2015-01-01

    Efficient light-matter interaction lies at the heart of many emerging technologies that seek on-chip integration of solid-state photonic systems. Plasmonic waveguides, which guide the radiation in the form of strongly confined surface plasmon-polariton modes, represent a promising solution to manipulate single photons in coplanar architectures with unprecedented small footprints. Here we demonstrate coupling of the emission from a single quantum emitter to the channel plasmon polaritons supported by a V-groove plasmonic waveguide. Extensive theoretical simulations enable us to determine the position and orientation of the quantum emitter for optimum coupling. Concomitantly with these predictions, we demonstrate experimentally that 42% of a single nitrogen vacancy centre emission efficiently couples into the supported modes of the V-groove. This work paves the way towards practical realization of efficient and long distance transfer of energy for integrated solid-state quantum systems.

  20. Voltage controlled optics of a monolayer semiconductor quantum emitter

    Science.gov (United States)

    Chakraborty, Chitraleema; Goodfellow, Kenneth; Kinnischtzke, Laura; Vamivakas, Nick; University of Rochester Team

    2015-03-01

    Two-dimensional atomically thin materials are being actively investigated for next generation optoelectronic devices. Particularly exciting are transition metal dichalcogenides (TMDC) since these materials exhibit a band gap, and support valley specific exciton mediated optical transitions. In this work we report the observation of single photon emission in the TMDC tungsten diselenide. We present magneto-optical spectroscopy results and demonstrate voltage controlled photoluminescence of these localized quantum emitters.

  1. Beta emitters and radiation protection

    DEFF Research Database (Denmark)

    Jødal, Lars

    2009-01-01

    , and 90Y, using data from a freely available database. Bremsstrahlung yields were calculated for 90Y shielded by lead, aluminium, or perspex. Bremsstrahlung spectrum from 90Y shielded by perspex was measured, and attenuation of spectrum by lead was calculated. Whole-body and finger doses to persons...... preparing 90Y-Zevalin were measured. CONCLUSIONS. Good laboratory practice is important to keep radiation doses low. To reduce bremsstrahlung, 90Y should not be shielded by lead but instead perspex (10 mm) or aluminium (5 mm). Bremsstrahlung radiation can be further reduced by adding a millimetre of lead......BACKGROUND. Beta emitters, such as 90Y, are increasingly being used for cancer treatment. However, beta emitters demand other precautions than gamma emitters during preparation and administration, especially concerning shielding. AIM. To discuss practical precautions for handling beta emitters...

  2. Single-bunch emittance dilution in the perfect ILC main linac

    Institute of Scientific and Technical Information of China (English)

    王逗; 高杰

    2011-01-01

    In the ILC (International Linear Collider) main linac, low emittance preservation is the most important issue for beam dynamics study. As the main sources of emittance dilution, the dispersive and wakefield effects were studied in this paper. The theoreti

  3. Cell analysis using a multiple internal reflection photonic lab-on-a-chip.

    Science.gov (United States)

    Vila-Planas, Jordi; Fernández-Rosas, Elisabet; Ibarlucea, Bergoi; Demming, Stefanie; Nogués, Carme; Plaza, Jose A; Domínguez, Carlos; Büttgenbach, Stephanus; Llobera, Andreu

    2011-09-29

    Here we present a protocol for analyzing cell cultures using a photonic lab-on-a-chip (PhLoC). By using a broadband light source and a spectrometer, the spectrum of a given cell culture with an arbitrary population is acquired. The PhLoC can work in three different regimes: light scattering (using label-free cells), light scattering plus absorption (using stained cells) and, by subtraction of the two former regimes, absorption (without the scattering band). The acquisition time of the PhLoC is ∼30 ms. Hence, it can be used for rapid cell counting, dead/live ratio estimation or multiparametric measurements through the use of different dyes. The PhLoC, including microlenses, micromirrors and microfluidics, is simply fabricated in a single-mask process (by soft lithographic methods) using low-cost materials. Because of its low cost it can easily be implemented for point-of-care applications. From raw substrates to final results, this protocol can be completed in 29 h.

  4. PREFACE: 1st International School and Conference "Saint Petersburg OPEN 2014" on Optoelectronics, Photonics, Engineering and Nanostructures

    Science.gov (United States)

    2014-09-01

    Dear Colleagues, 1st International School and Conference "Saint Petersburg OPEN 2014" on Optoelectronics, Photonics, Engineering and Nanostructures was held on March 25 - 27, 2014 at St. Petersburg Academic University - Nanotechnology Research and Education Centre of the Russian Academy of Sciences. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology. The keynote speakers were: Mikhail Glazov (Ioffe Physico-Technical Institute RAS, Russia) Vladimir Dubrovskii (Saint Petersburg Academic University RAS, Russia) Alexey Kavokin (University of Southampton, United Kingdom and St. Petersburg State University, Russia) Vladimir Korenev (Ioffe Physico-Technical Institute RAS, Russia) Sergey Kukushkin (Institute of Problems of Mechanical Engineering RAS, Russia) Nikita Pikhtin (Ioffe Physico-Technical Institute RAS, Russia and "Elfolum" Ltd., Russia) Dmitry Firsov (Saint Petersburg State Polytechnical University, Russia) During the poster session all undergraduate and graduate students attending the conference presented their works. Sufficiently large number of participants with more than 160 student attendees from all over the world allowed the Conference to provide a fertile ground for the fruitful discussions between the young scientists as well as to become a perfect platform for the valuable discussions between student authors and highly experienced scientists. The best student papers, which were selected by the Program Committee and by the invited speakers basing on the theses and their poster presentation, were awarded with diplomas of the conference - see the photos. This year's School and Conference is supported by SPIE (The International Society for Optics and Photonics), OSA (The Optical Society), St. Petersburg State Polytechnical University and by Skolkovo Foundation. It is a continuation of the annual schools and

  5. Optical Signatures of Quantum Emitters in Suspended Hexagonal Boron Nitride.

    Science.gov (United States)

    Exarhos, Annemarie L; Hopper, David A; Grote, Richard R; Alkauskas, Audrius; Bassett, Lee C

    2017-03-28

    Hexagonal boron nitride (h-BN) is rapidly emerging as an attractive material for solid-state quantum engineering. Analogously to three-dimensional wide-band-gap semiconductors such as diamond, h-BN hosts isolated defects exhibiting visible fluorescence at room temperature, and the ability to position such quantum emitters within a two-dimensional material promises breakthrough advances in quantum sensing, photonics, and other quantum technologies. Critical to such applications is an understanding of the physics underlying h-BN's quantum emission. We report the creation and characterization of visible single-photon sources in suspended, single-crystal, h-BN films. With substrate interactions eliminated, we study the spectral, temporal, and spatial characteristics of the defects' optical emission. Theoretical analysis of the defects' spectra reveals similarities in vibronic coupling to h-BN phonon modes despite widely varying fluorescence wavelengths, and a statistical analysis of the polarized emission from many emitters throughout the same single-crystal flake uncovers a weak correlation between the optical dipole orientations of some defects and h-BN's primitive crystallographic axes, despite a clear misalignment for other dipoles. These measurements constrain possible defect models and, moreover, suggest that several classes of emitters can exist simultaneously throughout free-standing h-BN, whether they be different defects, different charge states of the same defect, or the result of strong local perturbations.

  6. Biofilm structure and its influence on clogging in drip irrigation emitters distributing reclaimed wastewater

    Institute of Scientific and Technical Information of China (English)

    YAN Dazhuang; BAI Zhihui; Mike Rowan; GU Likun; Ren Shumei; YANG Peiling

    2009-01-01

    Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy (SEM) revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides (EPS) and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide and phospholipid fatty acids (PLFAs) showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coefficient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path (Emitter C) had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies.

  7. Assessment of beta-emitter radionuclides in biological samples using liquid scintillation counting. Application to the study of internal doses in molecular and cellular biology techniques; Evaluacion en muestras biologicas de radionucleidos emisores beta mediante espectrometria de centelleo en fase liquida. Aplicaciones al estudio de dosis internas en tecnicas de investigacion de biologia molecular y celular

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, I.; Delgado, A.; Navarro, T.; Macias, M. T.

    2007-07-01

    The radioisotopic techniques used in Molecular and Cellular Biology involve external and internal irradiation risk. It is necessary to control the possible internal contamination associated to the development of these techniques. The internal contamination risk can be due to physical and chemical properties of the labelled compounds, aerosols generated during the performance technique. The aim of this work was to estimate the possible intake of specific beta emitters during the technique development and to propose the required criterions to perform Individual Monitoring. The most representative radioisotopic techniques were selected attending their potential risk of internal contamination. Techniques were analysed applying IAEA methodology according to the used activity in each technique. It was necessary to identify the worker groups that would require individual monitoring on the base of their specific risk. Different measurement procedures were applied to study the possible intake in group risk and more than 160 persons were measured by in vitro bioassay. (Author) 96 refs.

  8. Some remarks on photons statistics in the LS-counter

    Energy Technology Data Exchange (ETDEWEB)

    Broda, R. [Institute of Atomic Energy, Radioisotope Centre POLATOM, 05-400 Otwock-Swierk (Poland)], E-mail: r.broda@polatom.pl

    2008-06-15

    The available experimental data relating to processes in the liquid scintillation (LS) detector that lead to fluorescence have been analysed and the evaluated number of photons created are given. The evaluated global distribution of photons emitted from the LS-vial in the case of low-energy emitters is presented. The global distribution of photons is well fitted by the Polya distribution.

  9. Optical characterization of OLED emitter properties by radiation pattern analyses

    Energy Technology Data Exchange (ETDEWEB)

    Flaemmich, Michael

    2011-09-08

    Researches in both, academia and industry are investigating optical loss channels in OLED layered systems by means of optical simulation tools in order to derive promising concepts for a further enhancement of the overall device performance. Besides other factors, the prospects of success of such optimization strategies rely severely on the credibility of the optical input data. The present thesis provides a guideline to measure the active optical properties of OLED emitter materials in situ by radiation pattern analyses. Reliable and widely applicable methods are introduced to determine the internal electroluminescence spectrum, the profile of the emission zone, the dipole emitter orientation, and the internal luminescence quantum efficiency of emissive materials from the optical far field emission of OLEDs in electrical operation. The proposed characterization procedures are applied to sets of OLEDs containing both, fluorescent polymeric materials as well as phosphorescent small-molecular emitters, respectively. On the one hand, quite expected results are obtained. On the other hand, several novel and truly surprising results are found. Most importantly, this thesis contains the first report of a non-isotropic, mainly parallel emitter orientation in a phosphorescent small-molecular guest-host system (Ir(MDQ)2(acac) in a-NPD). Due to the latter result, emitter orientation based optimization of phosphorescent OLEDs seems to be within reach. Since parallel dipoles emit preferably into air, the utilization of smart emissive materials with advantageous molecular orientation is capable to boost the efficiency of phosphorescent OLEDs by 50%. Materials design, the influence of the matrix material and the substrate, as well as film deposition conditions are just a few parameters that need to be studied further in order to exploit the huge potential of the dipole emitter orientation in phosphorescent OLEDs.

  10. Review of Emittance and Stability Monitoring Using Synchrotron Radiation Monitors

    CERN Document Server

    Holldack, K; Peatman, W B

    2001-01-01

    Different techniques of emittance and stability monitoring using bend magnet and undulator radiation will be reviewed. Besides imaging methods for emittance monitoring , the problem of XBPM's used for the measurement of the centre of mass position of the undulator beams will be treated in detail. The key feature of these monitors is a careful electron optical design to take account of gap dependent changes of the shape and photon energy of the undulator beam as well as spurious signals from dipoles and high heat load. The reason for the fact that these monitors work well on low energy machines like BESSY II but often fail due in high energy machines will be demonstrated by experimental results obtained on different types of BESSY II insertion devices such as undulators, wavelength shifters, multipole wigglers and electromagnetic undulators. Experimental results of global and local orbit monitoring and a proof of principle of a XBPM-based local feedback will be shown.

  11. Quantum Optics with Photonic Nanowires and Photonic Trumpets: Basics and Applications

    DEFF Research Database (Denmark)

    Gerard, J.; Claudon, J.; Munsch, M.

    Optimizing the coupling between a localized quantum emitter and a single-mode optical channel represents a powerful route to realise bright sources of non-classical light states. Reversibly, the e±cient absorption of a photon impinging on the emitter is key to realise a spin-photon interface......, the node of future quantum networks. Besides optical microcavities [1], photonic wires have recently demonstrated in this context an appealing potential [2, 3]. For instance, single photon sources (SPS) based on a single quantum dot in a vertical photonic wire with integrated bottom mirror and tapered tip...... have enabled for the ¯rst time to achieve simultaneously a very high e±ciency (0.72 photon per pulse) and a very pure single photon emission (g(2)(0)

  12. Engineering and localization of quantum emitters in large hexagonal boron nitride layers

    CERN Document Server

    Choi, Sumin; ElBadawi, Christopher; Lobo, Charlene; Wang, Xuewen; Juodkazis, Saulius; Seniutinas, Gediminas; Toth, Milos; Aharonovich, Igor

    2016-01-01

    Hexagonal boron nitride (hBN) is a wide bandgap van der Waals material that has recently emerged as promising platform for quantum photonics experiments. In this work we study the formation and localization of narrowband quantum emitters in large flakes (up to tens of microns wide) of hBN. The emitters can be activated in as-grown hBN by electron irradiation or high temperature annealing, and the emitter formation probability can be increased by ion implantation or focused laser irradiation of the as-grown material. Interestingly, we show that the emitters are always localized at edges of the flakes, unlike most luminescent point defects in 3D materials. Our results constitute an important step on the road map of deploying hBN in nanophotonics applications.

  13. Emitter and absorber assembly for multiple self-dual operation and directional transparency

    CERN Document Server

    Kalozoumis, P A; Kodaxis, G; Diakonos, F K; Schmelcher, P

    2016-01-01

    A recursive scheme for the design of scatterers acting simultaneously as emitters and absorbers, such as lasers and coherent perfect absorbers in optics, at multiple prescribed frequencies is proposed. The approach is based on the assembly of non-Hermitian emitter and absorber units into self-dual emitter-absorber trimers at different composition levels, exploiting the simple structure of the corresponding transfer matrices. In particular, lifting the restriction to parity-time-symmetric setups enables the realization of emitter and absorber action at distinct frequencies and provides flexibility in the choice of realistic parameters. We further show how the same assembled scatterers can be rearranged to produce unidirectional and bidirectional transparency at the selected frequencies. With the design procedure being generically applicable to wave scattering in single-channel settings, we demonstrate it with concrete examples of photonic multilayer setups.

  14. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D;

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  15. Electric field distribution of electron emitter surfaces

    Science.gov (United States)

    Tagawa, M.; Takenobu, S.; Ohmae, N.; Umeno, M.

    1987-03-01

    The electric field distribution of a tungsten field emitter surface and a LaB6 thermionic emitter surface has been studied. The computer simulation of electric field distribution on the emitter surface was carried out with a charge simulation method. The electric field distribution of the LaB6 thermionic emitter was experimentally evaluated by the Schottky plot. Two independent equations are necessary for obtaining local electric field and work function; the Fowler-Nordheim equation and the equation of total energy distribution of emitted electron being used to evaluate the electric field distribution of the tungsten field emitter. The experimental results agreed with the computer simulation.

  16. Entropy driven multi-photon frequency up-conversion

    CERN Document Server

    Manor, Assaf; Rotschild, Carmel

    2013-01-01

    Frequency up-conversion of few low-energy photons into a single high-energy photon, greatly contributes to imaging, light sources, detection and other fields of research. However, it offers negligible efficiency when up-converting many photons. This is because coherent process are fundamentally limited due to momentum conservation requirements, while in incoherent up-conversion the finite intermediate states lifetime requires huge intensities. Thermodynamically, conventional incoherent up-conversion is driven by the internal energy of the incoming photons. However, a system can also drive work through change in its collective properties such as entropy. Here we experimentally demonstrate entropy driven ten-fold up-conversion from 10.6{\\mu} to 1{\\mu}m at internal efficiency above 27% and total efficiency above 10%. In addition, the emitted radiance at 1{\\mu}m exceeds the maximal possible Black-Body radiance of our device, indicating emitter's effective-temperature that is considerably above the bulk-temperatur...

  17. Feasibility of a ring FEL at low emittance storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, I., E-mail: ilya.agapov@xfel.eu

    2015-09-01

    A scheme for generating coherent radiation at latest generation low emittance storage rings such as PETRA III at DESY (Balewski et al., 2004 [1]) is proposed. The scheme is based on focusing and subsequent defocusing of the electron beam in the longitudinal phase space at the undulator location. The expected performance characteristics are estimated for radiation in the wavelength range of 500–1500 eV. It is shown that the average brightness is increased by several orders of magnitude compared to spontaneous undulator radiation, which can open new perspectives for photon-hungry soft X-ray spectroscopy techniques.

  18. Beam emittance measurements at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Manfred; Eddy, Nathan; Hu, Martin; Scarpine, Victor; Syphers, Mike; Tassotto, Gianni; Thurman-Keup, Randy; Yang, Ming-Jen; Zagel, James; /Fermilab

    2008-01-01

    We give short overview of various beam emittance measurement methods, currently applied at different machine locations for the Run II collider physics program at Fermilab. All these methods are based on beam profile measurements, and we give some examples of the related instrumentation techniques. At the end we introduce a multi-megawatt proton source project, currently under investigation at Fermilab, with respect to the beam instrumentation challenges.

  19. Compact Rare Earth Emitter Hollow Cathode

    Science.gov (United States)

    Watkins, Ronald; Goebel, Dan; Hofer, Richard

    2010-01-01

    A compact, high-current, hollow cathode utilizing a lanthanum hexaboride (LaB6) thermionic electron emitter has been developed for use with high-power Hall thrusters and ion thrusters. LaB6 cathodes are being investigated due to their long life, high current capabilities, and less stringent xenon purity and handling requirements compared to conventional barium oxide (BaO) dispenser cathodes. The new cathode features a much smaller diameter than previously developed versions that permit it to be mounted on axis of a Hall thruster ( internally mounted ), as opposed to the conventional side-mount position external to the outer magnetic circuit ("externally mounted"). The cathode has also been reconfigured to be capable of surviving vibrational loads during launch and is designed to solve the significant heater and materials compatibility problems associated with the use of this emitter material. This has been accomplished in a compact design with the capability of high-emission current (10 to 60 A). The compact, high-current design has a keeper diameter that allows the cathode to be mounted on the centerline of a 6- kW Hall thruster, inside the iron core of the inner electromagnetic coil. Although designed for electric propulsion thrusters in spacecraft station- keeping, orbit transfer, and interplanetary applications, the LaB6 cathodes are applicable to the plasma processing industry in applications such as optical coatings and semiconductor processing where reactive gases are used. Where current electrical propulsion thrusters with BaO emitters have limited life and need extremely clean propellant feed systems at a significant cost, these LaB6 cathodes can run on the crudest-grade xenon propellant available without impact. Moreover, in a laboratory environment, LaB6 cathodes reduce testing costs because they do not require extended conditioning periods under hard vacuum. Alternative rare earth emitters, such as cerium hexaboride (CeB6) can be used in this

  20. Room-temperature single-photon sources based on nanocrystal fluorescence in photonic/plasmonic nanostructures

    Science.gov (United States)

    Lukishova, S. G.; Winkler, J. M.; Bissell, L. J.; Mihaylova, D.; Liapis, Andreas C.; Shi, Z.; Goldberg, D.; Menon, V. M.; Boyd, R. W.; Chen, G.; Prasad, P.

    2014-10-01

    Results are presented here towards robust room-temperature SPSs based on fluorescence in nanocrystals: colloidal quantum dots, color-center diamonds and doped with trivalent rare-earth ions (TR3+). We used cholesteric chiral photonic bandgap and Bragg-reflector microcavities for single emitter fluorescence enhancement. We also developed plasmonic bowtie nanoantennas and 2D-Si-photonic bandgap microcavities. The paper also provides short outlines of other technologies for room-temperature single-photon sources.

  1. Plasmonic-enhanced two-photon fluorescence with single gold nanoshell

    Science.gov (United States)

    Zhang, TianYue; Lu, GuoWei; Shen, HongMing; Perriat, P.; Martini, M.; Tillement, O.; Gong, QiHuang

    2014-06-01

    Single gold nanoshell with mutilpolar plasmon resonances is proposed to enhance two-photon fluorescence efficiently. The single emitter single nanoshell configuration is studied systematically by employing the finite-difference time-domain method. The emitter located inside or outside the nanoshell at various positions leads to a significantly different enhancement effect. The fluorescent emitter placed outside the nanoshell can achieve large fluorescence intensity given that both the position and orientation of the emission dipole are optimally controlled. In contrast, for the case of the emitter placed inside the nanoshell, it can experience substantial two-photon fluorescence enhancement without strict requirements upon the position and dipole orientations. Metallic nanoshell encapsulating many fluorescent emitters should be a promising nanocomposite configuration for bright two-photon fluorescence label. The results provide a comprehensive understanding about the plasmonic-enhanced two-photon fluorescence behaviors, and the nanocomposite configuration has great potential for optical detecting, imaging and sensing in biological applications.

  2. Near-infrared-to-visible highly selective thermal emitters based on an intrinsic semiconductor.

    Science.gov (United States)

    Asano, Takashi; Suemitsu, Masahiro; Hashimoto, Kohei; De Zoysa, Menaka; Shibahara, Tatsuya; Tsutsumi, Tatsunori; Noda, Susumu

    2016-12-01

    Control of the thermal emission spectra of emitters will result in improved energy utilization efficiency in a broad range of fields, including lighting, energy harvesting, and sensing. In particular, it is challenging to realize a highly selective thermal emitter in the near-infrared-to-visible range, in which unwanted thermal emission spectral components at longer wavelengths are significantly suppressed, whereas strong emission in the near-infrared-to-visible range is retained. To achieve this, we propose an emitter based on interband transitions in a nanostructured intrinsic semiconductor. The electron thermal fluctuations are first limited to the higher-frequency side of the spectrum, above the semiconductor bandgap, and are then enhanced by the photonic resonance of the structure. Theoretical calculations indicate that optimized intrinsic Si rod-array emitters with a rod radius of 105 nm can convert 59% of the input power into emission of wavelengths shorter than 1100 nm at 1400 K. It is also theoretically indicated that emitters with a rod radius of 190 nm can convert 84% of the input power into emission of emissivity of 0.77 at a wavelength of 790 nm and a very low background emissivity of <0.02 to 0.05 at 1100 to 7000 nm, under operation at 1273 K. Use of a nanostructured intrinsic semiconductor that can withstand high temperatures is promising for the development of highly efficient thermal emitters operating in the near-infrared-to-visible range.

  3. A tunable waveguide-coupled cavity design for scalable interfaces to solid-state quantum emitters

    Directory of Open Access Journals (Sweden)

    Sara L. Mouradian

    2017-04-01

    Full Text Available Photonic nanocavities in diamond have emerged as useful structures for interfacing photons and embedded atomic color centers, such as the nitrogen vacancy center. Here, we present a hybrid nanocavity design that enables (i a loaded quality factor exceeding 50 000 (unloaded Q>106 with 75% of the enhanced emission collected into an underlying waveguide circuit, (ii MEMS-based cavity spectral tuning without straining the diamond, and (iii the use of a diamond waveguide with straight sidewalls to minimize surface defects and charge traps. This system addresses the need for scalable on-chip photonic interfaces to solid-state quantum emitters.

  4. Silicon photonics fundamentals and devices

    CERN Document Server

    Deen, M Jamal

    2012-01-01

    The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...

  5. A semiconductor photon-sorter

    Science.gov (United States)

    Bennett, A. J.; Lee, J. P.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

    2016-10-01

    Obtaining substantial nonlinear effects at the single-photon level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the photons. We report effective interactions between photons, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.

  6. A chip-scale, telecommunications-band frequency conversion interface for quantum emitters.

    Science.gov (United States)

    Agha, Imad; Ates, Serkan; Davanço, Marcelo; Srinivasan, Kartik

    2013-09-09

    We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable for common single photon emitters. Four-wave-mixing Bragg scattering in silicon nitride waveguides is used to demonstrate frequency upconversion and downconversion between the 980 nm and 1550 nm wavelength regions, with signal-to-background levels > 10 and conversion efficiency of ≈ -60 dB at low continuous wave input pump powers ( 25 % in existing geometries. Finally, we present waveguide designs that can be used to connect shorter wavelength (637 nm to 852 nm) quantum emitters with 1550 nm.

  7. A new method of emittance measurement for electron beams from the Micro-emitter

    Energy Technology Data Exchange (ETDEWEB)

    Ishizuka, Hiroshi [Fukuoka Inst. of Technology (Japan); Nakahara, Yuriko; Kawasaki, Sunao; Musyoki, Stephen; Shimizu, Hiroshi; Watanabe, Akihiko; Shiho, Makoto

    1994-03-01

    Recently a new type of cathode called Micro-emitter is in progress. This cathode is micro fabricated field emitter having the characteristics of very low emittance and high brightness. We can not measure the emittance of the cathode with conventional method like pepper-pot method. The reasons are ; 1. The angle between the electron orbit and the axis is very small. ; and 2. We can not focus the electron beam in the vacuum or on the surface of the material since the current density of the cathode is extremely high. For the emittance measurement for such low emittance and high brightness cathode, we need to expand the beam, and measure the beam cross section without any slits or apertures. We study and propose a new emittance measurement method for the Micro-emitter. (author).

  8. Operating single quantum emitters with a compact Stirling cryocooler

    Energy Technology Data Exchange (ETDEWEB)

    Schlehahn, A.; Krüger, L.; Gschrey, M.; Schulze, J.-H.; Rodt, S.; Strittmatter, A.; Heindel, T., E-mail: tobias.heindel@tu-berlin.de; Reitzenstein, S. [Institute of Solid State Physics, Technische Universität Berlin, 10623 Berlin (Germany)

    2015-01-15

    The development of an easy-to-operate light source emitting single photons has become a major driving force in the emerging field of quantum information technology. Here, we report on the application of a compact and user-friendly Stirling cryocooler in the field of nanophotonics. The Stirling cryocooler is used to operate a single quantum emitter constituted of a semiconductor quantum dot (QD) at a base temperature below 30 K. Proper vibration decoupling of the cryocooler and its surrounding enables free-space micro-photoluminescence spectroscopy to identify and analyze different charge-carrier states within a single quantum dot. As an exemplary application in quantum optics, we perform a Hanbury-Brown and Twiss experiment demonstrating a strong suppression of multi-photon emission events with g{sup (2)}(0) < 0.04 from this Stirling-cooled single quantum emitter under continuous wave excitation. Comparative experiments performed on the same quantum dot in a liquid helium (LHe)-flow cryostat show almost identical values of g{sup (2)}(0) for both configurations at a given temperature. The results of this proof of principle experiment demonstrate that low-vibration Stirling cryocoolers that have so far been considered exotic to the field of nanophotonics are an attractive alternative to expensive closed-cycle cryostats or LHe-flow cryostats, which could pave the way for the development of high-quality table-top non-classical light sources.

  9. Operating single quantum emitters with a compact Stirling cryocooler.

    Science.gov (United States)

    Schlehahn, A; Krüger, L; Gschrey, M; Schulze, J-H; Rodt, S; Strittmatter, A; Heindel, T; Reitzenstein, S

    2015-01-01

    The development of an easy-to-operate light source emitting single photons has become a major driving force in the emerging field of quantum information technology. Here, we report on the application of a compact and user-friendly Stirling cryocooler in the field of nanophotonics. The Stirling cryocooler is used to operate a single quantum emitter constituted of a semiconductor quantum dot (QD) at a base temperature below 30 K. Proper vibration decoupling of the cryocooler and its surrounding enables free-space micro-photoluminescence spectroscopy to identify and analyze different charge-carrier states within a single quantum dot. As an exemplary application in quantum optics, we perform a Hanbury-Brown and Twiss experiment demonstrating a strong suppression of multi-photon emission events with g((2))(0) Stirling-cooled single quantum emitter under continuous wave excitation. Comparative experiments performed on the same quantum dot in a liquid helium (LHe)-flow cryostat show almost identical values of g((2))(0) for both configurations at a given temperature. The results of this proof of principle experiment demonstrate that low-vibration Stirling cryocoolers that have so far been considered exotic to the field of nanophotonics are an attractive alternative to expensive closed-cycle cryostats or LHe-flow cryostats, which could pave the way for the development of high-quality table-top non-classical light sources.

  10. Operating single quantum emitters with a compact Stirling cryocooler

    Science.gov (United States)

    Schlehahn, A.; Krüger, L.; Gschrey, M.; Schulze, J.-H.; Rodt, S.; Strittmatter, A.; Heindel, T.; Reitzenstein, S.

    2015-01-01

    The development of an easy-to-operate light source emitting single photons has become a major driving force in the emerging field of quantum information technology. Here, we report on the application of a compact and user-friendly Stirling cryocooler in the field of nanophotonics. The Stirling cryocooler is used to operate a single quantum emitter constituted of a semiconductor quantum dot (QD) at a base temperature below 30 K. Proper vibration decoupling of the cryocooler and its surrounding enables free-space micro-photoluminescence spectroscopy to identify and analyze different charge-carrier states within a single quantum dot. As an exemplary application in quantum optics, we perform a Hanbury-Brown and Twiss experiment demonstrating a strong suppression of multi-photon emission events with g(2)(0) < 0.04 from this Stirling-cooled single quantum emitter under continuous wave excitation. Comparative experiments performed on the same quantum dot in a liquid helium (LHe)-flow cryostat show almost identical values of g(2)(0) for both configurations at a given temperature. The results of this proof of principle experiment demonstrate that low-vibration Stirling cryocoolers that have so far been considered exotic to the field of nanophotonics are an attractive alternative to expensive closed-cycle cryostats or LHe-flow cryostats, which could pave the way for the development of high-quality table-top non-classical light sources.

  11. Hybrid emitter all back contact solar cell

    Science.gov (United States)

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  12. Emittance investigation of RF photo-injector

    CERN Document Server

    Yang Mao Rong; Li Zheng; Li Ming; Xu Zhou

    2002-01-01

    A high-power laser beam illuminates a photocathode surface placed on an end wall of an RF cavity. The emitted electrons are accelerated immediately to a relativistic energy by the strong RF find in the cavity. But space charge effect induces beam emittance growth especially near the cathode where the electrons are still nonrelativistic. The author analyzes the factors which lead the transverse emittance growth and method how to resolve this problem. After introducing solenoidal focusing near the photocathode, the beam emittance growth is suppressed dramatically. The beam emittance is given also after compensation and simulation results. The measurements show these results are coincident

  13. Minimum emittance in TBA and MBA lattices

    Science.gov (United States)

    Xu, Gang; Peng, Yue-Mei

    2015-03-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

  14. Low Emittance Guns for the ILC Polarized Electron Beam

    Science.gov (United States)

    Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Miller, R. H.; Wang, J. W.; Zhou, F.

    2007-06-01

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of ⩾200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while ⩾500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns.

  15. Nanoamorphous carbon-based photonic crystal infrared emitters

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, Robert A. (Tucson, AZ); Skotheim, Terje (Tucson, AZ)

    2011-12-13

    Provided is a tunable radiation emitting structure comprising: a nanoamorphous carbon structure having a plurality of relief features provided in a periodic spatial configuration, wherein the relief features are separated from each other by adjacent recessed features, and wherein the nanoamorphous carbon comprises a total of from 0 to 60 atomic percent of one or more dopants of the dopant group consisting of: transition metals, lanthanoids, electro-conductive carbides, silicides and nitrides. In one embodiment, a dopant is selected from the group consisting of: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La and other lanthanides, Hf, Ta, W, Rh, Os, Ir, Pt, Au, and Hg. In one embodiment, a dopant is selected from the group consisting of: electro-conductive carbides (like Mo.sub.2C), silicides (like MoSi.sub.2) and nitrides (like TiN).

  16. Integrated Photonic Circuit Fabrication for Enabling RF Emitter Array

    Science.gov (United States)

    2013-09-01

    signal to the phototransistor has a bottom silica cladding layer that is tapered to a germanium layer in order to minimize light scattering at the...Microelectromech. S. 12, 761 (Dec 2003). 10. http://www.cyantek.com/ chrome -etchants.php (30 May 2013). 11. http://www.microchrometechnology.com...for Micromachining Processing— Part II” J. Microelectromech. S. 12, 761 (Dec 2003) 15. http://www.cyantek.com/ chrome -etchants.php (30 May 2013) 16

  17. Photon-Photon Collisions -- Past and Future

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC

    2005-12-02

    I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy {gamma}{gamma} and e{gamma} tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy {gamma}{gamma} collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider.

  18. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons

    Science.gov (United States)

    Hadid, L.; Desbrée, A.; Schlattl, H.; Franck, D.; Blanchardon, E.; Zankl, M.

    2010-07-01

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  19. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons.

    Science.gov (United States)

    Hadid, L; Desbrée, A; Schlattl, H; Franck, D; Blanchardon, E; Zankl, M

    2010-07-07

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  20. Efficient single-mode photon-coupling device utilizing a nanofiber tip.

    Science.gov (United States)

    Chonan, Sho; Kato, Shinya; Aoki, Takao

    2014-04-24

    Single-photon sources are important elements in quantum optics and quantum information science. It is crucial that such sources be able to couple photons emitted from a single quantum emitter to a single propagating mode, preferably to the guided mode of a single-mode optical fiber, with high efficiency. Various photonic devices have been successfully demonstrated to efficiently couple photons from an emitter to a single mode of a cavity or a waveguide. However, efficient coupling of these devices to optical fibers is sometimes challenging. Here we show that up to 38% of photons from an emitter can be directly coupled to a single-mode optical fiber by utilizing the flat tip of a silica nanofiber. With the aid of a metallic mirror, the efficiency can be increased to 76%. The use of a silicon waveguide further increases the efficiency to 87%. This simple device can be applied to various quantum emitters.

  1. Modified Optical Properties of Semiconductor Quantum Dots by Photonic Structures

    Institute of Scientific and Technical Information of China (English)

    XIAO Min

    2004-01-01

    @@ Specially designed photonic structures, such as photonic crystals, can prevent light from propagating in certain directions with specified frequencies.Such photonic stsuctures exhibit many unique features that are highly desirable for the manufacture of photonic integrated circuits.There has been great interest in controlling light-emitters via photonic structures, which can partially suppress and redirect spontaneous emission.Encapsulating an active material in a well-designed photonic structure can successively reduce the active volume.Because the dimensions of the active volume are reduced to a few micrometers, spontaneous emission control can be achieved, which can provide lasing with improved directional, modal control, and reduced noise.

  2. Quantum optics with quantum dots in photonic wires

    DEFF Research Database (Denmark)

    Munsch, Mathieu; Cadeddu, Davide; Teissier, Jean

    2016-01-01

    We present an exploration of the spectroscopy of a single quantum dot in a photonic wire. The device presents a high photon extraction efficiency, and strong hybrid coupling to mechanical modes. We use resonance fluorescence to probe the emitter's properties with the highest sensitivity, allowing...

  3. Oxidation and emittance of superalloys in heat shield applications

    Science.gov (United States)

    Wiedemann, K. E.; Clark, R. K.; Unnam, J.

    1986-01-01

    Recently developed superalloys that form alumina coatings have a high potential for heat shield applications for advanced aerospace vehicles at temperatures above 1095C. Both INCOLOY alloy MA 956 (of the Inco Alloys International, Inc.), an iron-base oxide-dispersion-strengthened alloy, and CABOT alloy No. 214 (of the Cabot Corporation), an alumina-forming nickel-chromium alloy, have good oxidation resistance and good elevated temperature strength. The oxidation resistance of both alloys has been attributed to the formation of a thin alumina layer (alpha-Al2O3) at the surface. Emittance and oxidation data were obtained for simulated Space Shuttle reentry conditions using a hypersonic arc-heated wind tunnel. The surface oxides and substrate alloys were characterized using X-ray diffraction and scanning and transmission electron microscopy with an energy-dispersive X-ray analysis unit. The mass loss and emittance characteristics of the two alloys are discussed.

  4. Low Emittance X-FEL Development

    CERN Document Server

    Li, K S B; Anghel, A; Bakker, R J; Böge, M; Candel, A E; Dehler, M; Ganter, R; Gough, C; Ingold, G; Leemann, S C; Pedrozzi, M; Raguin, J Y; Rivkin, L; Schlott, V; Streun, A; Wrulich, A F

    2005-01-01

    The Paul Scherrer Institute (PSI) in Switzerland currently develops a Low-Emittance electron-Gun (LEG) based on field-emitter technology [1]. The target is a normalized transverse emittance of 5 10(-8) m rad or less. Such a source is particularly interesting for FELs that target wavelengths below 0.3 nm since it permits a reduction of the required beam-energy and hence, a reduction of the construction- and operational costs of X-ray FELs. That is, for the case that this initial low emittance can be maintained throughout the accelerator. Here we present a concept for a 0.1 nm X-FEL based on LEG, which can be located close to the Swiss Light Source (SLS). Special attention goes to the maintenance of the emittance during the process of acceleration and bunch-compression, in particular in the regimes where either space-charge forces or coherent-synchrotron radiation are of importance.

  5. Batch By Batch Longitudinal Emittance Blowup MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Jaussi, M; Molendijk, J

    2012-01-01

    The transverse bunch emittance increases significantly at 450 GeV from the time of injection till the ramp due to IBS. By selectively blowing up the longitudinal emittance of the incoming batch at each injection, it should be possible to reduce the transverse emittance growth rates due to IBS. An MD was conducted on April 22nd 2012 to test the feasibility and performance of the batch-by-batch longitudinal emittance blowup. There were three main goals during the MD. First, to test the developed hardware, firmware, and software for the batch-by-batch blowup. Then, to measure the transverse emittance growth rates of blown-up and "witness" batches to quantify any improvement, and finally to test the ALLInjectSequencer class, which deals with the complicated gymnastics of introducing or masking the new batch to various RF loops.

  6. Screen printed boron emitters for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Recart, F.; Freire, I.; Perez, L.; Lago-Aurrekoetxea, R.; Jimeno, J.C.; Bueno, G. [Instituto de Tecnologia Microelectronica, Teknologia Mikroelektronikoaren Institutua UPV/EHU, Alda.Urquijo s/n, 48013 Bilbao (Spain)

    2007-06-15

    Screen printed (SP) boron emitters are presented as a useful option for the manufacturing of p-type emitters of solar cells. Details are provided on the diffusion process, including deposition, drying and firing steps, the latter performed in an infrared belt furnace. Besides their main dependences on the firing conditions, the sheet resistances and dopant profiles of the resulting emitters reveal the relevance of the drying step and the exhaustion limits of the doping source. A characterization of the recombination concludes that moderate emitter saturation currents (J{sub oe}<0.5 pA/cm{sup 2}) and acceptable bulk lifetimes ({tau}{sub B}>40 {mu}s) can be obtained on Czochralski silicon wafers. Finally, Cz n-type 0.7 {omega} cm solar cells are presented, which once again prove the feasibility of SP boron emitters and point to issues regarding their metallization. (author)

  7. Emittance measurements of the CLIO electron beam

    Science.gov (United States)

    Chaput, R.; Devanz, G.; Joly, P.; Kergosien, B.; Lesrel, J.

    1997-02-01

    We have designed a setup to measure the transverse emittance at the CLIO accelerator exit, based on the "3 gradients" method. The beam transverse size is measured simply by scanning it with a steering coil across a fixed jaw and recording the transmitted current, at various quadrupole strengths. A code then performs a complete calculation of the emittance using the transfer matrix of the quadrupole instead of the usual classical lens approximation. We have studied the influence of various parameters on the emittance: Magnetic field on the e-gun and the peak current. We have also improved a little the emittance by replacing a mismatched pipe between the buncher and accelerating section to avoid wake-field effects; The resulting improvements of the emittance have led to an increase in the FEL emitted power.

  8. Single-photon quantum router with multiple output ports.

    Science.gov (United States)

    Yan, Wei-Bin; Fan, Heng

    2014-04-28

    The routing capability is a requisite in quantum network. Although the quantum routing of signals has been investigated in various systems both in theory and experiment, the general form of quantum routing with many output terminals still needs to be explored. Here we propose a scheme to achieve the multi-channel quantum routing of the single photons in a waveguide-emitter system. The channels are composed by the waveguides and are connected by intermediate two-level emitters. By adjusting the intermediate emitters, the output channels of the input single photons can be controlled. This is demonstrated in the cases of one output channel, two output channels and the generic N output channels. The results show that the multi-channel quantum routing of single photons can be well achieved in the proposed system. This offers a scheme for the experimental realization of general quantum routing of single photons.

  9. Microlensless interdigitated photoconductive terahertz emitters.

    Science.gov (United States)

    Singh, Abhishek; Prabhu, S S

    2015-01-26

    We report here fabrication of interdigitated photoconductive antenna (iPCA) terahertz (THz) emitters based on plasmonic electrode design. Novel design of this iPCA enables it to work without microlens array focusing, which is otherwise required for photo excitation of selective photoconductive regions to avoid the destructive interference of emitted THz radiation from oppositely biased regions. Benefit of iPCA over single active region PCA is, photo excitation can be done at larger area hence avoiding the saturation effect at higher optical excitation density. The emitted THz radiation power from plasmonic-iPCAs is ~2 times more than the single active region plasmonic PCA at 200 mW optical excitation, which will further increase at higher optical powers. This design is expected to reduce fabrication cost of photoconductive THz sources and detectors.

  10. Low Emittance Electron Beam Studies

    Energy Technology Data Exchange (ETDEWEB)

    Tikhoplav, Rodion [Univ. of Rochester, NY (United States)

    2006-01-01

    We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*01 mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

  11. Optical Photon Reassignment Microscopy (OPRA)

    CERN Document Server

    Roth, Stephan; Wicker, Kai; Heintzmann, Rainer

    2013-01-01

    To enhance the resolution of a confocal laser scanning microscope the additional information of a pinhole plane image taken at every excitation scan position can be used [C. J. R. Sheppard, Super-resolution in confocal imaging, Optik 80, 5354 (1988)]. This photon reassignment principle is based on the fact that the most probable position of an emitter is at half way between the nominal focus of the excitation laser and the position corresponding to the (off centre) detection position. Therefore, by reassigning the detected photons to this place, an image with enhanced detection efficiency and resolution is obtained. Here we present optical photon reassignment microscopy (OPRA) which realises this concept in an all-optical way obviating the need for image-processing. With the help of an additional intermediate optical beam expansion between descanning and a further rescanning of the detected light, an image with the advantages of photon reassignment can be acquired. Due to its simplicity and flexibility this m...

  12. Prototype of a subsurface drip irrigation emitter: Manufacturing, hydraulic evaluation and experimental analyses

    Science.gov (United States)

    Souza, Wanderley De Jesus; Rodrigues Sinobas, Leonor; Sánchez, Raúl; Arriel Botrel, Tarlei; Duarte Coelho, Rubens

    2013-04-01

    Root and soil intrusion into the conventional emitters is one of the major disadvantages to obtain a good uniformity of water application in subsurface drip irrigation (SDI). In the last years, there have been different approaches to reduce these problems such as the impregnation of emitters with herbicide, and the search for an emitter geometry impairing the intrusion of small roots. Within the last this study, has developed and evaluated an emitter model which geometry shows specific physical features to prevent emitter clogging. This work was developed at the Biosystems Engineering Department at ESALQ-USP/Brazil, and it is a part of a research in which an innovated emitteŕs model for SDI has been developed to prevent root and soil particles intrusion. An emitter with a mechanical-hydraulic mechanism (opening and closing the water outlet) for SDI was developed and manufactured using a mechanical lathe process. It was composed by a silicon elastic membrane a polyethylene tube and a Vnyl Polychloride membrane protector system. In this study the performance of the developed prototype was assessed in the laboratory and in the field conditions. In the laboratory, uniformity of water application was calculated by the water emission uniformity coefficient (CUE), and the manufacturer's coefficient of variation (CVm). In addition, variation in the membrane diameter submitted to internal pressures; head losses along the membrane, using the energy equation; and, precision and accuracy of the equation model, analyzed by Pearson's correlation coefficient (r), and by Willmott's concordance index (d) were also calculated with samples of the developed emitters. In the field, the emitters were installed in pots with and without sugar cane culture from October 2010 to January 2012. During this time, flow rate in 20 emitters were measured periodically, and the aspects of them about clogging at the end of the experiment. Emitters flow rates were measured quarterly to calculate

  13. A photonic nanowire trumpet for interfacing a quantum dot and a Gaussian free-space mode

    DEFF Research Database (Denmark)

    Gregersen, Niels; Munsch, Mathieu; Malik, Nitin S.;

    2013-01-01

    Efficient coupling between a localized quantum emitter and a well defined optical channel represents a powerful route to realize single-photon sources and spin-photon interfaces. The tailored fiber-like photonic nanowire embedding a single quantum dot has recently demonstrated an appealing...

  14. Shortwave-infrared (SWIR emitters for biological imaging: a review of challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Thimsen Elijah

    2017-08-01

    Full Text Available Shortwave infrared radiation (SWIR is the portion of the electromagnetic spectrum from approximately 900 nm to 2500 nm. Recent advances in imaging systems have expanded the application of SWIR emitters from traditional fields in materials science to biomedical imaging, and the new detectors in SWIR opened an opportunity of deep tissue imaging. Achieving deep photon penetration while maintaining high resolution is one of the main objectives and challenges in bioimaging used for the investigation of diverse processes in living organisms. The application of SWIR emitters in biological settings is, however, hampered by low quantum efficiency. So far, photoluminescent properties in the SWIR region have not been improved by extending concepts that have been developed for the visible (400–650 nm and near-infrared (NIR, 700–900 nm wavelengths, which indicates that the governing behavior is fundamentally different in the SWIR. The focus of this minireview is to examine the mechanisms behind the low efficiency of SWIR emitters as well as to highlight the progress in their design for biological applications. Several common mechanisms will be considered in this review: (a the effect of the energy gap between the excited and ground state on the quantum efficiency, (b the coupling of the excited electronic states in SWIR emitters to vibrational states in the surrounding matrix, and (c the role of environment in quenching the excited states. General strategies to improve the quantum yields for a diverse type of SWIR emitters will be also presented.

  15. Shortwave-infrared (SWIR) emitters for biological imaging: a review of challenges and opportunities

    Science.gov (United States)

    Thimsen, Elijah; Sadtler, Bryce; Berezin, Mikhail Y.

    2017-06-01

    Shortwave infrared radiation (SWIR) is the portion of the electromagnetic spectrum from approximately 900 nm to 2500 nm. Recent advances in imaging systems have expanded the application of SWIR emitters from traditional fields in materials science to biomedical imaging, and the new detectors in SWIR opened an opportunity of deep tissue imaging. Achieving deep photon penetration while maintaining high resolution is one of the main objectives and challenges in bioimaging used for the investigation of diverse processes in living organisms. The application of SWIR emitters in biological settings is, however, hampered by low quantum efficiency. So far, photoluminescent properties in the SWIR region have not been improved by extending concepts that have been developed for the visible (400-650 nm) and near-infrared (NIR, 700-900 nm) wavelengths, which indicates that the governing behavior is fundamentally different in the SWIR. The focus of this minireview is to examine the mechanisms behind the low efficiency of SWIR emitters as well as to highlight the progress in their design for biological applications. Several common mechanisms will be considered in this review: (a) the effect of the energy gap between the excited and ground state on the quantum efficiency, (b) the coupling of the excited electronic states in SWIR emitters to vibrational states in the surrounding matrix, and (c) the role of environment in quenching the excited states. General strategies to improve the quantum yields for a diverse type of SWIR emitters will be also presented.

  16. Evaluation of extremely small horizontal emittance

    Directory of Open Access Journals (Sweden)

    T. Okugi

    1999-02-01

    Full Text Available The KEK Accelerator Test Facility (KEK-ATF was constructed to develop technologies for producing a low-emittance beam which will be required by future linear colliders. The KEK-ATF consists of an injector linac, a damping ring, and a beam extraction line. The basic optical structure of the damping ring is a FOBO lattice, which reduces the horizontal dispersion at the center of the bending magnets and, as a consequence, can produce an extremely small emittance beam. To verify the performance of such a unique, low-emittance lattice, it is crucial to measure the horizontal emittance. The horizontal emittance was measured using wire scanners in the beam extraction line. Since the horizontal beam position was not stable, we established a method to correct the measured beam size for position fluctuation (“jitter” and we succeeded in the observation of the so far smallest horizontal emittance in any accelerator. The measured horizontal emittance was 1.37±0.03nm at a beam energy of 1.285 GeV and a bunch population of \\(3–5\\×10^{9}, in agreement with the design value of 1.27–1.34 nm at the beam energy and the bunch population.

  17. Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Pan; Wang, Hung-Ta; Yang, Peidong; Wang, Daojing

    2011-06-16

    Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA), and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3-inch silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel, can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nanoelectrospray for the high-density emitter array. We showed that electrospray current of the multinozzle emitter at a given total flow rate was approximately proportional to the square root of the number of its spraying-nozzles, suggesting the capability of high MS sensitivity for multinozzle emitters. Using a conventional Z-spray mass spectrometer, we demonstrated reproducible MS detection of peptides and proteins for serial MEA emitters, achieving sensitivity and stability comparable to the commercial capillary emitters. Our robust silicon-based MEA chip opens up the possibility of a fully-integrated microfluidic system for ultrahigh-sensitivity and ultrahigh-throughput proteomics and metabolomics.

  18. Controlling light emission from single-photon sources using photonic nanowires

    DEFF Research Database (Denmark)

    Gregersen, Niels; Chen, Yuntian; Mørk, Jesper

    2012-01-01

    The photonic nanowire has recently emerged as an promising alternative to microcavity-based single-photon source designs. In this simple structure, a geometrical effect ensures a strong coupling between an embedded emitter and the optical mode of interest and a combination of tapers and mirrors...... are used to tailor the far-field emission pattern. This non-resonant approach relaxes the demands to fabrication perfection, allowing for record-high measured efficiency of fabricated nanowire single-photon sources. We review recent progress in photonic nanowire technology and present next generation...

  19. Thermophotovoltaic emitter material selection and design

    Energy Technology Data Exchange (ETDEWEB)

    Saxton, P.C.; Moran, A.L.; Harper, M.J.; Lindler, K.W. [Naval Academy, Annapolis, MD (United States)

    1997-07-01

    Thermophotovoltaics (TPV) is a potentially attractive direct energy conversion technology. It reduces the need for complex machinery with moving parts and maintenance. TPV generators can be run from a variety of heat sources including waste heat for smaller scale operations. The US Naval Academy`s goal was to build a small experimental thermophotovoltaic generator powered by combustion gases from a General Electric T-58 helicopter gas turbine. The design of the generator imposes material limitations that directly affect emitter and structural materials selection. This paper details emitter material goals and requirements, and the methods used to select suitable candidate emitter materials for further testing.

  20. Laser wire emittance measurement line AT CLIC

    CERN Document Server

    Garcia, H; Blair, G A; Aumeyr, T; Schulte, D; Stulle, F

    2011-01-01

    A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical errors and of their impact on the accuracy of the emittance reconstruction are given. Laser wire systems suitable for CLIC and their main characteristics are discussed.

  1. Narrowband terahertz emitters using metamaterial films.

    Science.gov (United States)

    Alves, Fabio; Kearney, Brian; Grbovic, Dragoslav; Karunasiri, Gamani

    2012-09-10

    In this article we report on metamaterial-based narrowband thermal terahertz (THz) emitters with a bandwidth of about 1 THz. Single band emitters designed to radiate in the 4 to 8 THz range were found to emit as high as 36 W/m(2) when operated at 400 °C. Emission into two well-separated THz bands was also demonstrated by using metamaterial structures featuring more complex unit cells. Imaging of heated emitters using a microbolometer camera fitted with THz optics clearly showed the expected higher emissivity from the metamaterial structure compared to low-emissivity of the surrounding aluminum.

  2. Dependence of the modulation response of quantum dot based nanocavity devices on the number of emitters

    DEFF Research Database (Denmark)

    Lorke, Michael; Nielsen, Torben Roland; Mørk, Jesper

    2011-01-01

    A microscopic theory is used to study the dynamical properties of semiconductor quantum dot based nanocavity laser systems. The carrier kinetics and photon populations are determined using a fully quantum mechanical treatment of the light‐matter coupling. In this work, we investigate the dependen...... of the modulation response in such devices on the number of emitters coupled to the cavity mode. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)...

  3. Comparing the effect of low and high emittance on synchrotron radiation and beamline design

    Directory of Open Access Journals (Sweden)

    A Gholampour Azhir

    2017-08-01

    Full Text Available In this paper, we have discussed about the role of two emittance values suggested for Iranian Light Source Facility (ILSF (3.278 and 0.476 nm.rad on different radiation features of the synchrotron light sources (bending magnet, shaker and oscillator such as spot size, divergence of the beam on light spot, brilliance and important quantities in beamline design such as photon cross-section, optical element sizes and energy resolution  

  4. Electrically pumped single-defect light emitters in WSe2

    Science.gov (United States)

    Schwarz, S.; Kozikov, A.; Withers, F.; Maguire, J. K.; Foster, A. P.; Dufferwiel, S.; Hague, L.; Makhonin, M. N.; Wilson, L. R.; Geim, A. K.; Novoselov, K. S.; Tartakovskii, A. I.

    2016-06-01

    Recent developments in fabrication of van der Waals heterostructures enable new type of devices assembled by stacking atomically thin layers of two-dimensional materials. Using this approach, we fabricate light-emitting devices based on a monolayer WSe2, and also comprising boron nitride tunnelling barriers and graphene electrodes, and observe sharp luminescence spectra from individual defects in WSe2 under both optical and electrical excitation. This paves the way towards the realisation of electrically-pumped quantum emitters in atomically thin semiconductors. In addition we demonstrate tuning by more than 1 meV of the emission energy of the defect luminescence by applying a vertical electric field. This provides an estimate of the permanent electric dipole created by the corresponding electron-hole pair. The light-emitting devices investigated in our work can be assembled on a variety of substrates enabling a route to integration of electrically pumped single quantum emitters with existing technologies in nano-photonics and optoelectronics.

  5. Beam emittance measurements on multicusp ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Sarstedt, M.; Lee, Y.; Leung, K.N.; Perkins, L.T.; Pickard, D.S.; Weber, M.; Williams, M.D.

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source is planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 micron patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma.

  6. Beam emittance measurements on multicusp ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Sarstedt, M.; Lee, Y.; Leung, K.N. [and others

    1995-08-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 {mu}m patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf-pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of an rf-generated plasma.

  7. Beam emittance measurements on multicusp ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Sarstedt, M.; Lee, Y.; Leung, K.N.; Perkins, L.T.; Pickard, D.S.; Weber, M.; Williams, M.D. [Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

    1996-03-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source is planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 {mu}m patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of a rf-generated plasma. {copyright} {ital 1996 American Institute of Physics.}

  8. Beam emittance measurements on multicusp ion sources

    Science.gov (United States)

    Sarstedt, M.; Lee, Y.; Leung, K. N.; Perkins, L. T.; Pickard, D. S.; Weber, M.; Williams, M. D.

    1996-03-01

    Multicusp ion sources are used for various applications. Presently, the implementation of this type of ion source is planned for the development of an ion beam lithography machine, which will be used for the projection of sub-0.2 μm patterns onto a wafer substrate. Since, for this application, a very good beam quality and a small ion energy spread are required, emittance measurements have been performed on a multicusp ion source for various source conditions. It is shown that the installation of proper capacitors between the extraction electrodes is necessary to avoid rf pickup, which otherwise leads to a distortion of the beam emittance. The influence of the magnetic filter field on the beam emittance has been investigated, and the beam emittance of a dc filament-discharge plasma has also been compared to that of a rf-generated plasma.

  9. Monochromatic gamma emitter for low energy quanta

    CERN Document Server

    Tomova, Z R; Mironova, S A

    2004-01-01

    The possibility of creating of a monochromatic gamma emitter of low energy quanta is analyzed. The idea is based on Daning's scheme. Except for purely scientific problems the monochromator is actual for therapy of wide range of diseases.

  10. Emittance growth in linear induction accelerators

    CERN Document Server

    Ekdahl, C A; Schulze, M E; Carlson, C A; Frayer, D K; Mostrum, C; Thoma, C H

    2014-01-01

    The Dual-Axis Radiographic Hydrotest (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. On the DARHT Axis-II LIA we measure an emittance higher than predicted by theoretical simulations, and even though this axis produces sub-millimeter source spots, we are exploring ways to improve the emittance. Some of the possible causes for the discrepancy have been investigated using particle-in-cell (PIC) codes, although most of these are discounted based on beam measurements. The most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.

  11. Emittance Growth in Linear Induction Accelerators

    OpenAIRE

    Ekdahl, Carl

    2017-01-01

    The Dual-Axis Radiographic Hydrotest (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. Some of the possible causes for the emittance growth in the DARHT LIA have been investigated using particle-in-ce...

  12. Alpha-emitters for medical therapy workshop

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E.; McClure, J.J.

    1996-12-31

    A workshop on ``Alpha-Emitters for Medical Therapy`` was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference.

  13. Monolithic integration of a quantum emitter with a compact on-chip beam-splitter

    Energy Technology Data Exchange (ETDEWEB)

    Prtljaga, N., E-mail: n.prtljaga@sheffield.ac.uk; Coles, R. J.; O' Hara, J.; Royall, B.; Fox, A. M.; Skolnick, M. S. [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom); Clarke, E. [Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2014-06-09

    A fundamental component of an integrated quantum optical circuit is an on-chip beam-splitter operating at the single-photon level. Here, we demonstrate the monolithic integration of an on-demand quantum emitter in the form of a single self-assembled InGaAs quantum dot (QD) with a compact (>10 μm), air clad, free standing directional coupler acting as a beam-splitter for anti-bunched light. The device was tested by using single photons emitted by a QD embedded in one of the input arms of the device. We verified the single-photon nature of the QD signal by performing Hanbury Brown-Twiss measurements and demonstrated single-photon beam splitting by cross-correlating the signal from the separate output ports of the directional coupler.

  14. PREFACE: 2nd International School and Conference Saint-Petersburg OPEN on Optoelectronics, Photonics, Engineering and Nanostructures (SPbOPEN2015)

    Science.gov (United States)

    2015-11-01

    The 2nd International School and Conference ''Saint Petersburg OPEN 2015'' on Optoelectronics, Photonics, Engineering and Nanostructures was held on April 6 - 8, 2015 at St. Petersburg Academic University. The School and Conference included a series of invited talks given by leading professors with the aim to introduce young scientists with actual problems and major advances in physics and technology. The keynote speakers were Mikhail V. Maximov (Ioffe Physico-Technical Institute RAS, Russia) Vladimir G. Dubrovskii (St. Petersburg Academic University and St. Petersburg State University, Russia) Anton Yu. Egorov (JSC Connector Optics, Russia) Victor V. Luchinin (St. Petersburg State Electrotechnical University, Russia) Vladislav E. Bugrov (St. Petersburg University of Internet Technologies, Mechanics and Optics, Russia) Vitali A. Schukin (VI Systems, Germany) Yuri P. Svirko (University of Eastern Finland, Finland) During the poster session all undergraduate and graduate students attending the conference presented their works. A sufficiently large number of participants, with more than 170 student attendees from all over the world, allowed the Conference to provide a fertile ground for fruitful discussions between the young scientists as well as to become a perfect platform for valuable discussions between student authors and highly experienced scientists. The best student papers, which were selected by the Program Committee and by the invited speakers basing on the theses and their poster presentation, were awarded with diplomas of the conference - see the photos. This year ''Saint Petersburg OPEN 2015'' is organized by St. Petersburg Academic University in cooperation with Peter the Great St. Petersburg Polytechnic University. The School and Conference is supported by Russian Science Foundation, SPIE (The International Society for Optics and Photonics), OSA (The Optical Society) and by Skolkovo Foundation. It is a continuation of the annual schools and seminars for

  15. Novel photonic crystal cavities and related structures.

    Energy Technology Data Exchange (ETDEWEB)

    Luk, Ting Shan

    2007-11-01

    The key accomplishment of this project is to achieve a much more in-depth understanding of the thermal emission physics of metallic photonic crystal through theoretical modeling and experimental measurements. An improved transfer matrix technique was developed to enable incorporation of complex dielectric function. Together with microscopic theory describing emitter radiative and non-radiative relaxation dynamics, a non-equilibrium thermal emission model is developed. Finally, experimental methodology was developed to measure absolute emissivity of photonic crystal at high temperatures with accuracy of +/-2%. Accurate emissivity measurements allow us to validate the procedure to treat the effect of the photonic crystal substrate.

  16. Molecular photons interfaced with alkali atoms.

    Science.gov (United States)

    Siyushev, Petr; Stein, Guilherme; Wrachtrup, Jörg; Gerhardt, Ilja

    2014-05-01

    Future quantum communication will rely on the integration of single-photon sources, quantum memories and systems with strong single-photon nonlinearities. Two key parameters are crucial for the single-photon source: a high photon flux with a very small bandwidth, and a spectral match to other components of the system. Atoms or ions may act as single-photon sources--owing to their narrowband emission and their intrinsic spectral match to other atomic systems--and can serve as quantum nonlinear elements. Unfortunately, their emission rates are still limited, even for highly efficient cavity designs. Single solid-state emitters such as single organic dye molecules are significantly brighter and allow for narrowband photons; they have shown potential in a variety of quantum optical experiments but have yet to be interfaced with other components such as stationary memory qubits. Here we describe the optical interaction between Fourier-limited photons from a single organic molecule and atomic alkali vapours, which can constitute an efficient quantum memory. Single-photon emission rates reach up to several hundred thousand counts per second and show a high spectral brightness of 30,000 detectable photons per second per megahertz of bandwidth. The molecular emission is robust and we demonstrate perfect tuning to the spectral transitions of the sodium D line and efficient filtering, even for emitters at ambient conditions. In addition, we achieve storage of molecular photons originating from a single dibenzanthanthrene molecule in atomic sodium vapour. Given the large set of molecular emission lines matching to atomic transitions, our results enable the combination of almost ideal single-photon sources with various atomic vapours, such that experiments with giant single-photon nonlinearities, mediated, for example, by Rydberg atoms, become feasible.

  17. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  18. Effect of phonon-plasmon and surface plasmon polaritons on photoluminescence in quantum emitter and graphene deposited on polar crystals

    Science.gov (United States)

    Singh, Mahi R.; Brzozowski, Marek J.; Apter, Boris

    2016-09-01

    We investigate the light-matter interaction in a quantum emitter and metallic graphene flake (MGF) hybrid system deposited on a polar material. The coupling of surface plasmons in graphene and optical phonons in the polar material produces phonon-plasmon polaritons (PPPs). Similarly, couplings of photons with surface plasmons of graphene produce surface-plasmon polaritons (SPPs). Using the second quantized formulation for SPPs and PPPs interactions and density matrix method, we have calculated photoluminescence of the quantum emitters. It is found that when the exciton energy of the quantum emitter is in resonant with SPP and PPP energies, the photoluminescence in the quantum emitter are enhanced in the terahertz range. The enhancement is due to the transfer of SPP and PPP energies from the graphene flake to the quantum emitter. The energy transfer from graphene to the quantum emitter can be controlled by applying external pump lasers or stress and strain fields. These are interesting findings which can be used to fabricate switches and sensors.

  19. Development of internal components for M38999 type connectors, for use in advanced photonic applications and with specialty optical fibers

    Science.gov (United States)

    Whitebook, Alan; Caloz, Francois

    2014-09-01

    This presentation outlines development work performed to produce internal components (connector insert assemblies & optical terminus assemblies) to be fit into MIL-DTL-38999, or commercial off the shelf (COTS) equivalent, connector housings. Connectors modified with these internal components are then suitable for optical termination and transmission through specialty fibers such as polarization maintaining, small core single-mode, and others, with the ability to achieve high levels of performance in the areas of insertion loss, return loss, polarization extinction ratio (as applicable) and power handling capability (as applicable.) Technical details are presented to illustrate features within the optical terminus, and its insert cavity, which serves to allow for fiber/ferrule polar orientation, concentricity of mated termini ferrules and fibers terminated within, and other attributes designed to support optical performance goals. Finally, optical performance data is given and discussed to illustrate results achieved by production of evaluation cable assemblies. emblies.

  20. Internal contamination monitoring through measurements in vivo at whole body contamination unity of IRD-CNEN, Rio de Janeiro, Brazil; Monitoracao da contaminacao interna atraves de medicoes in vivo na Unidade de Contador de Corpo Inteiro do IRD-CNEN, Rio de Janeiro, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Ana Leticia A.; Lucena, Eder A.; Dantas, Bernardo M., E-mail: adantas@ird.gov.b, E-mail: eder@ird.gov.b, E-mail: bmdantas@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Monitoracao In Vivo. Servico de Monitoracao Individual Interna

    2011-10-26

    The present work approaches the internal contamination monitoring capacity through measurements performed at the Whole-body Counter Unity of the in-vivo monitoring laboratory (LABMIV) of the IRD-CNEN, Rio de Janeiro, Brazil, present thr main parameters related to the monitoring techniques developed, and the the available instrumentation for identification and quantification in vivo of photon emitter radionuclides with energy in the range of 10-3000 keV, incorporated by workers and public individuals

  1. Cherenkov counting efficiencies for {beta}{sup -}-emitters in dry state in glass vials

    Energy Technology Data Exchange (ETDEWEB)

    Morita-Murase, Yuko; Murakami, Isao; Homma, Yoshio [Laboratory for Radiopharmaceutical Chemistry, Kyoritsu College of Pharmacy, Tokyo (Japan)

    2000-10-01

    Cherenkov counting efficiencies for standardized {beta}{sup -} -emitters in the dry state at the centre of air-filled glass vials were measured with a liquid scintillation spectrometer. Cherenkov counting efficiencies, which are plotted as a function of the average energy of {beta}{sup -}-particles and the internal conversion electrons, give a straight line on log-log scale. (author)

  2. Estimation of atomic interaction parameters by photon counting

    DEFF Research Database (Denmark)

    Kiilerich, Alexander Holm; Mølmer, Klaus

    2014-01-01

    Detection of radiation signals is at the heart of precision metrology and sensing. In this article we show how the fluctuations in photon counting signals can be exploited to optimally extract information about the physical parameters that govern the dynamics of the emitter. For a simple two......-level emitter subject to photon counting, we show that the Fisher information and the Cram\\'er- Rao sensitivity bound based on the full detection record can be evaluated from the waiting time distribution in the fluorescence signal which can, in turn, be calculated for both perfect and imperfect detectors...

  3. Dynamically reconfigurable directionality of plasmon-based single photon sources

    CERN Document Server

    Chen, Yuntian; Koenderink, A Femius

    2010-01-01

    We propose a plasmon-based reconfigurable antenna to controllably distribute emission from single quantum emitters in spatially separated channels. Our calculations show that crossed particle arrays can split the stream of photons from a single emitter into multiple narrow beams. We predict that beams can be switched on and off by switching host refractive index. The design method is based on engineering the dispersion relations of plasmon chains and is generally applicable to traveling wave antennas. Controllable photon delivery has potential applications in classical and quantum communication.

  4. Estimation of atomic interaction parameters by photon counting

    DEFF Research Database (Denmark)

    Kiilerich, Alexander Holm; Mølmer, Klaus

    2014-01-01

    Detection of radiation signals is at the heart of precision metrology and sensing. In this article we show how the fluctuations in photon counting signals can be exploited to optimally extract information about the physical parameters that govern the dynamics of the emitter. For a simple two......-level emitter subject to photon counting, we show that the Fisher information and the Cram\\'er- Rao sensitivity bound based on the full detection record can be evaluated from the waiting time distribution in the fluorescence signal which can, in turn, be calculated for both perfect and imperfect detectors...

  5. Dynamically reconfigurable directionality of plasmon-based single photon sources

    DEFF Research Database (Denmark)

    Chen, Yuntian; Lodahl, Peter; Koenderink, A. Femius

    2010-01-01

    We propose a plasmon-based reconfigurable antenna to controllably distribute emission from single quantum emitters in spatially separated channels. Our calculations show that crossed particle arrays can split the stream of photons from a single emitter into multiple narrow beams. We predict...... that beams can be switched on and off by switching host refractive index. The design method is based on engineering the dispersion relations of plasmon chains and is generally applicable to traveling wave antennas. Controllable photon delivery has potential applications in classical and quantum communication....

  6. Super-resolving multi-photon interferences with independent light sources

    CERN Document Server

    Oppel, Steffen; Kok, Pieter; von Zanthier, Joachim

    2012-01-01

    Multi-photon interferences with indistinguishable photons from independent light sources are at the focus of current research owing to their potential in optical quantum computing, creating remote entanglement for quantum computation and communication, and quantum metrology. The paradigmatic states for multi-photon interference are the highly entangled NOON states, which can be used to achieve increased resolution in spectroscopy, interferometry, lithography, and microscopy. Multi-photon interferences from independent, uncorrelated emitters can also lead to enhanced resolution in metrology and imaging. So far, such interferences have been observed with maximally two independent emitters. Here, we report multi-photon interferences with up to five independent emitters, displaying interference patterns equivalent to those of NOON states. Experimental results with independent thermal light sources confirm this NOON-like modulation. The experiment is an extension of the landmark measurement by Hanbury Brown and Tw...

  7. Nonlinear Photonics 2014: introduction.

    Science.gov (United States)

    Akhmediev, N; Kartashov, Yaroslav

    2015-01-12

    International Conference "Nonlinear Photonics-2014" took place in Barcelona, Spain on July 27-31, 2014. It was a part of the "Advanced Photonics Congress" which is becoming a traditional notable event in the world of photonics. The current focus issue of Optics Express contains contributions from the participants of the Conference and the Congress. The articles in this focus issue by no means represent the total number of the congress contributions (around 400). However, it demonstrates wide range of topics covered at the event. The next conference of this series is to be held in 2016 in Australia, which is the home of many researchers working in the field of photonics in general and nonlinear photonics in particular.

  8. Thin-film 'Thermal Well' Emitters and Absorbers for High-Efficiency Thermophotovoltaics

    CERN Document Server

    Tong, Jonathan K; Huang, Yi; Boriskina, Svetlana V; Chen, Gang

    2015-01-01

    A new approach is introduced to significantly improve the performance of thermophotovoltaic (TPV) systems by using low-dimensional thermal emitters and photovoltaic (PV) cells. By reducing the thickness of both the emitter and the PV cell, strong spectral selectivity in both thermal emission and absorption can be achieved by confining photons in trapped waveguide modes inside the thin-films that act as thermal analogs to quantum wells. Simultaneously, photo-excited carriers travel shorter distances across the thin-films reducing bulk recombination losses resulting in a lower saturation current in the PV cell. We predict a TPV efficiency enhancement with near-field coupling between the thermal emitter and the PV cell of up to 38.7% using a germanium (Ge) emitter at 1000 K and a gallium antimonide (GaSb) cell with optimized thicknesses separated by 100 nm. Even in the far-field limit, the efficiency is predicted to reach 31.5%, which is an order of magnitude higher than the Shockley Queisser limit of 1.6% for a...

  9. High-temperature plasmonic thermal emitter for thermophotovotaics

    DEFF Research Database (Denmark)

    Liu, Jingjing; Guler, Urcan; Li, Wei

    2014-01-01

    We use titanium nitride (TiN) to demonstrate an ultra-thin plasmonic thermal emitter operating at high temperatures (830 K). The spectrally selective emitter exhibits a large emittance at around 2.5 μm and below, and suppresses emission at longer wavelengths.......We use titanium nitride (TiN) to demonstrate an ultra-thin plasmonic thermal emitter operating at high temperatures (830 K). The spectrally selective emitter exhibits a large emittance at around 2.5 μm and below, and suppresses emission at longer wavelengths....

  10. Emittance measurement of high-brightness microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Ishizuka, Hiroshi; Nakahara, Yuriko (Fukuoka Inst. of Tech. (Japan)); Kawasaki, Sunao; Musyoki, S.; Shimizu, Hiroshi; Watanabe, Akihiko; Shiho, Makoto

    1994-09-01

    Arrays of microtriodes have recently become available due to the development of microfabricated field-emission electron sources. Computer simulation has shown that the brightness of beams emitted by them is significantly higher than that of the common microbeams, and possible application of the accelerated beam to free electron lasers has been discussed. Experimentation on beam generation has started, but methods for diagnosing the beam have not yet been established. Difficulty is predicted, because of the high brightness, in applying the conventional methods of emittance measurement. In this paper we propose a new method that determines the emittance without using apertures. The cross section of a converging beam is elongated by a quadrupole lens, and parameters of the emittance ellipse are obtained from the beam size on a screen when changing either the strength or the axial position of the quadrupole lens. (author).

  11. Quantum emitters coupled to circular nanoantennas for high-brightness quantum light sources

    Science.gov (United States)

    Abudayyeh, Hamza A.; Rapaport, Ronen

    2017-09-01

    Engineering the directionality and emission rate of quantum light sources is essential in the development of modern quantum applications. In this work we use numerical calculations to optimise the brightness of a broadband quantum emitter positioned in a hybrid metal-dielectric circular periodic nanoantenna. The optimised structure features a photon collection efficiency of 74 % (82 % ) and a photon flux enhancement of over 10 (6) into a numerical aperture of 0.22 (0.50), respectively, corresponding to a direct coupling into two types of multi-mode fibres. To enhance the emission rate, we present a new circular nanoantenna design where a quantum emitter is attached to a silver nanocone at the centre of the antenna. After optimisation, we find a collection efficiency of 61 % (78 % ) into a numerical aperture of 0.22 (0.50), giving a brightness enhancement of 1000 (600) for an unpolarised emitter. The enhancements in both structures are broadband due to the low-quality factor of the device and are therefore ideal for room-temperature sources. This type of a scalable design can be utilised towards on-chip, high-brightness quantum light sources operating at room temperature.

  12. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  13. A highly efficient single-photon source based on a quantum dot in a photonic nanowire

    DEFF Research Database (Denmark)

    Claudon, Julien; Bleuse, Joel; Malik, Nitin Singh

    2010-01-01

    The development of efficient solid-state sources of single photons is a major challenge in the context of quantum communication,optical quantum information processing and metrology1. Such a source must enable the implementation of a stable, single-photon emitter, like a colour centre in diamond2...... with carefully tailored ends13. Under optical pumping, we demonstrate a record source efficiency of 0.72, combined with pure single-photon emission. This non-resonant approach also provides broadband spontaneous emission control, thus offering appealing novel opportunities for the development of single...

  14. Highly efficient photonic nanowire single-photon sources for quantum information applications

    DEFF Research Database (Denmark)

    Gregersen, Niels; Claudon, J.; Munsch, M.

    2013-01-01

    must feature near-unity efficiency, where the efficiency is defined as the number of detected photons per trigger, the probability g(2)(τ=0) of multi-photon emission events should be 0 and the emitted photons are required to be indistinguishable. An optically or electrically triggered quantum light......  factor, meaning that efficient coupling from the QD to the guided mode is obtained over a broad spectral range of ~ 50-100 nm. [4] This means that spectral alignment between the emitter line and a narrow cavity line is not required, which represents a huge practical advantage in the fabrication...

  15. Photonic bands and defect modes in metallo-dielectric photonic crystal slabs

    CERN Document Server

    Zanotto, Simone; Sorba, Lucia; Tredicucci, Alessandro

    2016-01-01

    Photonic components based on structured metallic elements show great potential for device applications where field enhancement and confinement of the radiation on a subwavelength scale is required. In this paper we report a detailed study of a prototypical metallo-dielectric photonic structure, where features well known in the world of dielectric photonic crystals, like band gaps and defect modes, are exported to the metallic counterpart, with interesting applications to infrared science and technology, as for instance in quantum well infrared photodetectors, narrow-band spectral filters, and tailorable thermal emitters.

  16. Measurement of transverse emittance and coherence of double-gate field emitter array cathodes

    Science.gov (United States)

    Tsujino, Soichiro; Das Kanungo, Prat; Monshipouri, Mahta; Lee, Chiwon; Miller, R. J. Dwayne

    2016-12-01

    Achieving small transverse beam emittance is important for high brightness cathodes for free electron lasers and electron diffraction and imaging experiments. Double-gate field emitter arrays with on-chip focussing electrode, operating with electrical switching or near infrared laser excitation, have been studied as cathodes that are competitive with photocathodes excited by ultraviolet lasers, but the experimental demonstration of the low emittance has been elusive. Here we demonstrate this for a field emitter array with an optimized double-gate structure by directly measuring the beam characteristics. Further we show the successful application of the double-gate field emitter array to observe the low-energy electron beam diffraction from suspended graphene in minimal setup. The observed low emittance and long coherence length are in good agreement with theory. These results demonstrate that our all-metal double-gate field emitters are highly promising for applications that demand extremely low-electron bunch-phase space volume and large transverse coherence.

  17. Bright Room-Temperature Single Photon Emission from Defects in Gallium Nitride

    CERN Document Server

    Berhane, Amanuel M; Bodrog, Zoltán; Fiedler, Saskia; Schröder, Tim; Triviño, Noelia Vico; Palacios, Tomás; Gali, Adam; Toth, Milos; Englund, Dirk; Aharonovich, Igor

    2016-01-01

    Single photon emitters play a central role in many photonic quantum technologies. A promising class of single photon emitters consists of atomic color centers in wide-bandgap crystals, such as diamond silicon carbide and hexagonal boron nitride. However, it is currently not possible to grow these materials as sub-micron thick films on low-refractive index substrates, which is necessary for mature photonic integrated circuit technologies. Hence, there is great interest in identifying quantum emitters in technologically mature semiconductors that are compatible with suitable heteroepitaxies. Here, we demonstrate robust single photon emitters based on defects in gallium nitride (GaN), the most established and well understood semiconductor that can emit light over the entire visible spectrum. We show that the emitters have excellent photophysical properties including a brightness in excess of 500x10^3 counts/s. We further show that the emitters can be found in a variety of GaN wafers, thus offering reliable and s...

  18. Research on Radar Emitter Attribute Recognition Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to solve emitter recognition problems in a practical reconnaissance environment, attribute mathematics is introduced. The basic concepts and theory of attribute set and attribute measure are described in detail. A new attribute recognition method based on attribute measure is presented in this paper. Application example is given, which demonstrates this new method is accurate and effective. Moreover, computer simulation for recognizing the emitter purpose is selected, and compared with classical statistical pattern recognition through simulation. The excellent experimental results demonstrate that this is a brand-new attribute recognition method as compared to existing statistical pattern recognition techniques.

  19. Quadrupole Transfer Function for Emittance Measurement

    CERN Document Server

    Cameron, Peter; Jansson, Andreas; Tan, Cheng-Yang

    2008-01-01

    Historically the use of the quadrupole moment measurement has been impeded by the requirement for large dynamic range, as well as measurement sensitivity to beam position. We investigate the use of the transfer function technique [1-3] in combination with the sensitivity and 160dB revolution line rejection of the direct diode detection analog front end [4] to open the possibility of an emittance diagnostic that may be implemented without operational complication, quasi- parasitic to the operation of existing tune measurement systems. Such a diagnostic would be particularly useful as an emittance monitor during acceleration ramp development in machines like RHIC and the LHC.

  20. Current Injection Pumping of Organic Light Emitters

    Science.gov (United States)

    1989-09-28

    MOT-OOO1AF I Current Injection Pumping of Organic Light Emitters Prepared by DI Jeffrey C. Buchholz E L ri: 8 James P. Stec OCT C "t989 Mary C...Schutte Micro -Optics Technologies, Inc. 8608 University Green #5 Middleton, WI 53562 28 September 1989 D,:?UqflON SA2". N’.’ _ Disuibunon Uanu-ted Contract...Title Report Date Current Injection Pumping of Organic Light Emitters 28 September 1989 Authors Jeffrey C. Buchholz, James P. Stec, Mary C. Schutte

  1. Design and analysis of the internally cooled silicon mirrors and benders for wiggler sources at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Schildkamp, W.; Jaski, Y. [Consortium for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Tonnessen, T.; Douglas, G. [Rocketdyne Albuquerque Operations, 2511 C. Broadbent Parkway, N.E., Albuquerque, NM 87107 (United States)

    1996-09-01

    When silicon single crystal mirrors are bent to cylindrical figures of typically 6 km bending radius, the moments needed are very small and easy to disturb by cooling attachments to the sides of the mirror. Hence, we decided to abandon the conventional concept of cooling plates attached to the sides of the mirrors and instead have chosen to use internal water channels. We present here the design of mirrors with cooling channels near the neutral axis of the silicon beam that have a rather thick {open_quote}{open_quote}hot wall.{close_quote}{close_quote} The results of this analytical work are nonintuitive, regarding the stresses produced by wiggler heating. The design path chosen minimizes figure errors due to coolant pressure variations and residual stresses from machining and bonding of multiple layers of silicon. The geometry of the water channels avoids water-to-vacuum seals and uses the mirror bender as the coolant manifold. Engineering efforts, which reduce the bending stresses at bender-to-silicon interface by a factor of five, will be presented. The complete mirror bender and motion control mechanics will be shown. {copyright} {ital 1996 American Institute of Physics.}

  2. Diamond field emitter array cathodes and possibilities of employing additive manufacturing for dielectric laser accelerating structures

    Science.gov (United States)

    Simakov, Evgenya I.; Andrews, Heather L.; Herman, Matthew J.; Hubbard, Kevin M.; Weis, Eric

    2017-03-01

    Demonstration of a stand-alone practical dielectric laser accelerator (DLA) requires innovation in two major critical components: high-current ultra-low-emittance cathodes and efficient laser accelerator structures. LANL develops two technologies that in our opinion are applicable to the novel DLA architectures: diamond field emitter array (DFEA) cathodes and additive manufacturing of photonic band-gap (PBG) structures. This paper discusses the results of testing of DFEA cathodes in the field-emission regime and the possibilities for their operation in the photoemission regime, and compares their emission characteristics to the specific needs of DLAs. We also describe recent advances in additive manufacturing of dielectric woodpile structures using a Nanoscribe direct laser-writing device capable of maskless lithography and additive manufacturing, and the development of novel infrared dielectric materials compatible with additive manufacturing.

  3. Collective plasmon-modes in gain media quantum emitters and plasmonic nanostructures

    CERN Document Server

    Rivera, V A G; Ledemi, Y; Messaddeq, Y; Marega Jr , E

    2015-01-01

    This book represents the first detailed description, including both theoretical aspects and experimental methods, of the interaction of rare-earth ions with surface plasmon polariton from the point of view of collective plasmon-photon interactions via resonance modes (metal nanoparticles or nanostructure arrays) with quantum emitters (rare-earth ions). These interactions are of particular interest for applications to optical telecommunications, optical displays, and laser solid state technologies. Thus, our main goal is to give a more precise overview of the rapidly emerging field of nanophotonics by means of the study of the quantum properties of light interaction with matter at the nanoscale. In this way, collective plasmon-modes in a gain medium result from the interaction/coupling between a quantum emitter (created by rare-earth ions) with a metallic surface, inducing different effects such as the polarization of the metal electrons (so-called surface plasmon polariton - SPP), a field enhancement sustaine...

  4. Microwave Photonics

    OpenAIRE

    Seeds, A.J.; Liu, C. P.; T. Ismail; Fice, M. J.; Pozzi, F; Steed, R. J.; Rouvalis, E.; Renaud, C.C.

    2010-01-01

    Microwave photonics is the use of photonic techniques for the generation, transmission, processing and reception of signals having spectral components at microwave frequencies. This tutorial reviews the technologies used and gives applications examples.

  5. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    A review is given of the space-time wave mechanics of single photons, a subject with an almost century long history. The Landau-Peierls photon wave function, which is related nonlocally to the electromagnetic field is first described, and thereafter the so-called energy wave function, based...... on the positive-frequency Riemann-Silberstein vectors, is discussed. Recent attempts to understand the birth process of a photon emerging from a single atom are summarized. The polychromatic photon concept is introduced, and it is indicated how the wave mechanics of polychromatic photons can be upgraded to wave...... train quantum electrodynamics. A brief description of particle (photon) position operators is given, and it is shown that photons usually are only algebraically confined in an emission process. Finally, it is demonstrated that the profile of the birth domain of a radio-frequency photon emitted...

  6. Emittance growth from electron beam modulation

    Energy Technology Data Exchange (ETDEWEB)

    Blaskiewicz, M.

    2009-12-01

    In linac ring colliders like MeRHIC and eRHIC a modulation of the electron bunch can lead to a modulation of the beam beam tune shift and steering errors. These modulations can lead to emittance growth. This note presents simple formulas to estimate these effects which generalize some previous results.

  7. Longitudinal emittance measurements at REX-ISOLDE

    CERN Document Server

    Fraser, M A; Jones, R.M.; Jones, R M; Pasini, M; Posocco, P A; Voulot, D; Wenander, F

    2012-01-01

    We report on measurements of the longitudinal emittance at the Radioactive ion beam EXperiment (REX) at ISOLDE, CERN. The rms longitudinal emittance was measured as 0.34 ± 0.08 π ns keV/u at the output of the RFQ and as 0.36 ± 0.04π ns keV/u in front of the third 7-gap split-ring resonator (7G3) using the three-gradient technique; systematic errors are not included but are estimated at approximately 10%. The 86% emittance was measured a factor of approximately 4.4 times larger than the rms emittance at 1.48 ± 0.2 and 1.55 ± 0.12π ns keV/u at the RFQ and 7G3, respectively. The REX switchyard magnet was used as a spectrometer to analyse the energy spread of the beam as it was manipulated by varying the voltage of the rebuncher (ReB) and 7G3 cavities operating at non-accelerating phases. The transfer matrix for a multi-gap bunching cavity is derived and suitably truncated to allow for the accurate reconstruction of the beam parameters from measurement. The technique for measuring the energy spread was rig...

  8. Beam characterization for the field-emitter-array cathode-based low-emittance gun

    Directory of Open Access Journals (Sweden)

    S. C. Leemann

    2007-07-01

    Full Text Available A 1   Å x-ray free electron laser can be operated at 6 GeV provided a very high brightness electron beam. Therefore, Paul Scherrer Institute has initiated development of the low-emittance gun based on field emission. A field-emitter array (FEA is expected to deliver high peak current while reducing the source emittance to levels close to the thermal limit. A 100 keV gun test stand has been designed in order to gain experience with electron bunches emitted by pulsed FEAs, investigate emittance compensation, and develop diagnostic procedures to characterize the beam. First FEA samples have been installed and pulsed in the gun; the emitted bunches have been accelerated and characterized. We present results acquired with the first FEA samples.

  9. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    on the positive-frequency Riemann-Silberstein vectors, is discussed. Recent attempts to understand the birth process of a photon emerging from a single atom are summarized. The polychromatic photon concept is introduced, and it is indicated how the wave mechanics of polychromatic photons can be upgraded to wave...

  10. Nanoelectrospray emitter arrays providing interemitter electric field uniformity.

    Science.gov (United States)

    Kelly, Ryan T; Page, Jason S; Marginean, Ioan; Tang, Keqi; Smith, Richard D

    2008-07-15

    Arrays of electrospray ionization (ESI) emitters have been reported previously as a means of enhancing ionization efficiency or signal intensity. A key challenge when working with multiple, closely spaced ESI emitters is overcoming the deleterious effects caused by electrical interference among neighboring emitters. Individual emitters can experience different electric fields depending on their relative position in the array, such that it becomes difficult to operate all of the emitters optimally for a given applied potential. In this work, we have developed multi-nanoESI emitters arranged with a circular pattern, which enable the constituent emitters to experience a uniform electric field. The performance of the circular emitter array was compared to a single emitter and to a previously developed linear emitter array, which verified that improved electric field uniformity was achieved with the circular arrangement. The circular arrays were also interfaced with a mass spectrometer via a matching multicapillary inlet, and the results were compared with those obtained using a single emitter. By minimizing interemitter electric field inhomogeneities, much larger arrays having closer emitter spacing should be feasible.

  11. What is so super about super-emitters? Characterizing methane high emitters from natural gas infrastructure

    Science.gov (United States)

    Zavala Araiza, D.; Lyon, D. R.; Alvarez, R.; Harriss, R. C.; Palacios, V.; Hamburg, S.

    2015-12-01

    Methane emissions across the natural gas supply chain are dominated at any one time by a few high-emitters (super-emitters or fat-tail of the distribution), often underrepresented in published datasets used to construct emission inventories. Characterization of high-emitters is essential for improving emission estimates based on atmospheric data (top-down) and emission inventories (bottom-up). The population of high-emitters (e.g. 10-20% of sites that account for 80-90% of the emissions) is temporally and spatially dynamic. As a consequence, it is challenging to design sampling methods and construct estimates that accurately represent their frequency and magnitude of emissions. We present new methods to derive facility-specific emission distribution functions that explicitly integrate the influence of the relatively rare super-emitters. These methods were applied in the Barnett Shale region to construct a custom emission inventory that is then compared to top-down emission estimates for the region. We offer a methodological framework relevant to the design of future sampling campaigns, in which these high-emitters are seamlessly incorporated to representative emissions distributions. This framework can be applied to heterogeneous oil and gas production regions across geographies to obtain accurate regional emission estimates. Additionally, we characterize emissions relative to the fraction of a facility's total methane throughput; an effective metric to identify sites with excess emissions resulting from avoidable operating conditions, such as malfunctioning equipment (defined here as functional super-emitters). This work suggests that identifying functional super-emitters and correcting their avoidable operating conditions would result in significant emission reductions. However, due to their spatiotemporal dynamic behavior, achieving and maintaining uniformly low emissions across the entire population of sites will require mitigation steps (e.g. leak detection

  12. Single photon emission and detection at the nanoscale utilizing semiconductor nanowires

    NARCIS (Netherlands)

    Reimer, M.E.; van Kouwen, M.P.; Barkelid, M., et al.

    2011-01-01

    We report recent progress toward on-chip single photon emission and detection in the near infrared utilizing semiconductor nanowires. Our single photon emitter is based on a single InAsP quantum dot embedded in a p-n junction defined along the growth axis of an InP nanowire. Under forward bias,

  13. Single photon emission and detection at the nanoscale utilizing semiconductor nanowires

    NARCIS (Netherlands)

    Reimer, M.E.; van Kouwen, M.P.; Barkelid, M., et al.

    2011-01-01

    We report recent progress toward on-chip single photon emission and detection in the near infrared utilizing semiconductor nanowires. Our single photon emitter is based on a single InAsP quantum dot embedded in a p-n junction defined along the growth axis of an InP nanowire. Under forward bias, ligh

  14. A Design Report of the Baseline for PEP-X: an Ultra-Low Emittance Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl; Bertsche, Kirk; Cai, Yunhai; Chao, Alex; Corbett, Willian; Fox, John; Hettel, Robert; Huang, Xiaobiao; Huang, Zhirong; Ng, Cho-Kuen; Nosochkov, Yuri; Novokhatski, Sasha; Radedeau, Thomas; Raubenheimer, Tor; Rivetta, Claudio; Safranek, James; Seeman, John; Stohr, Joachim; Stupakov, Gennady; Wang, Lanfa; Wang, Min-Huey; /SLAC

    2010-06-02

    Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEPII tunnel. The design features a hybrid lattice with double bend achromat (DBA) cells in two arcs and theoretical minimum emittance (TME) cells in the remaining four arcs. Damping wigglers are used to reduce the horizontal emittance to 86 pm-rad at zero current for a 4.5 GeV electron beam. At a design current of 1.5 A, the horizontal emittance increases, due to intrabeam scattering, to 164 pm-rad when the vertical emittance is maintained at a diffraction limited 8 pm-rad. The baseline design will produce photon beams achieving a brightness of 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV in a 3.5-m conventional planar undulator. Our study shows that an optimized lattice has adequate dynamic aperture, while accommodating a conventional off-axis injection system. In this report, we present the results of study, including the lattice properties, nonlinear dynamics, intra-beam scattering and Touschek lifetime, RF system, and collective instabilities. Finally, we discuss the possibility of partial lasing at soft X-ray wavelengths using a long undulator in a straight section.

  15. Metallic photonic crystals for thermophotovoltaic applications

    Science.gov (United States)

    Walsh, Timothy A.

    Since the idea of a photonic bandgap was proposed over two decades ago, photonic crystals have been the subject of significant interest due to their novel optical properties which enable new and varied applications. In this research, the photonic bandgap effect is exploited to tailor the thermal radiation spectrum to a narrow range of wavelengths determined by the lattice symmetry and dimensions of the photonic crystal structure. This sharp emission peak can be matched to the electronic bandgap energy of a p-n junction photovoltaic cell for high efficiency thermophotovoltaic energy conversion. This thesis explores aspects of photonic crystal design, materials considerations, and manufacture for thermophotovoltaic applications. Photonic crystal structures come in many forms, exhibiting various types of 1D, 2D, and 3D lattice symmetry. In this work, the "woodpile" 3D photonic crystal is studied. One advantage of the woodpile lattice is that it can be readily fabricated on a large scale using common integrated circuit manufacturing techniques. Additionally this structure lends itself to efficient and accurate modeling with the use of a plane-wave expansion based transfer matrix method to calculate the scattering properties and band structure of the photonic crystal. This method is used to explore the geometric design parameters of the woodpile structure. Optimal geometric proportions for the structure are found which yield the highest narrowband absorption peak possible. By Kirchoffs law of thermal emission, this strong and sharp absorptance will yield high power and narrowband thermal radiation. The photonic crystal thermal emission spectrum is then evaluated in a TPV system model to evaluate the electrical power density and system efficiency achievable. The results produced by the photonic crystal emitter are compared with the results assuming a blackbody thermal radiation spectrum. The blackbody represents a universal standard against which any selective emitter

  16. Photon management assisted by surface waves on photonic crystals

    CERN Document Server

    Angelini, Angelo

    2017-01-01

    This book illustrates original pathways to manipulate light at the nanoscale by means of surface electromagnetic waves (here, Bloch surface waves, BSWs) on planar dielectric multilayers, also known as one-dimensional photonic crystals. This approach is particularly valuable as it represents an effective alternative to the widely exploited surface plasmon paradigm. After a brief overview on the fundamentals of BSWs, several significant applications of BSW-sustaining structures are described. Particular consideration is given to the propagation, guiding, and diffraction of BSW-coupled radiation. Further, the interaction of organic emitters with BSWs on planar and corrugated multilayers is investigated, including fluorescence beaming in free space. To provide greater insight into sensing applications, an illustrative example of fluorescent microarray-based detection is presented. The book is intended for scientists and researchers working on photon management opportunities in fields such as biosensing, optical c...

  17. Design of highly efficient metallo-dielectric patch antennas for single-photon emission.

    Science.gov (United States)

    Bigourdan, F; Marquier, F; Hugonin, J-P; Greffet, J-J

    2014-02-10

    Quantum emitters such as NV-centers or quantum dots can be used as single-photon sources. To improve their performance, they can be coupled to microcavities or nano-antennas. Plasmonic antennas offer an appealing solution as they can be used with broadband emitters. When properly designed, these antennas funnel light into useful modes, increasing the emission rate and the collection of single-photons. Yet, their inherent metallic losses are responsible for very low radiative efficiencies. Here, we introduce a new design of directional, metallo-dielectric, optical antennas with a Purcell factor of 150, a total efficiency of 74% and a collection efficiency of emitted photons of 99%.

  18. Modal coupling of single photons to a nanofibre

    CERN Document Server

    Gaio, Michele; Castro-Lopez, Marta; Pisignano, Dario; Camposeo, Andrea; Sapienza, Riccardo

    2015-01-01

    Nanoscale quantum optics of individual light emitters placed in confined geometries is developing as an exciting new research field aiming at efficient manipulation of single-photons . This requires selective channelling of light into specific optical modes of nanophotonic structures. Hybrid photonic systems combining emitters with nanostructured media can yield this functionality albeit limited by the required nanometre-scale spatial and spectral coupling. Furthermore, assessing the coupling strength presents significant challenges and disentangling the different modal contribution is often impossible. Here, we show that momentum spectroscopy of individually addressed emitters, embedded in a nanofibre, can be used to quantify the modal coupling efficiency to the nanofibre modes. For free-standing polymer nanofibres doped with colloidal quantum dots, we report broadband coupling to the fundamental mode of up $\\beta_{01}=31\\pm2\\%$, in robust agreement with theoretical calculations. Electrospun soft-matter nano...

  19. Tunable single-photon frequency conversion in a Sagnac interferometer

    Science.gov (United States)

    Yan, Wei-Bin; Huang, Jin-Feng; Fan, Heng

    2013-12-01

    Quantum information carriers like photons might be manipulated, stored and transmitted in different quantum systems. It is important to integrate those systems efficiently. The capability of converting photons from one wavelength to another wavelength is a key requirement for combining the photons in telecommunications band for quantum transmission and the photons in near-visible band for quantum storage. Here, we investigate the tunable single-photon frequency conversion in the five-level emitter-Sagnac interferometer system. We show that the efficient single-photon conversion can be achieved in this scheme, at the same time, the frequencies of the input and output photons can be tuned in a large scale by controlling the frequencies and Rabi frequencies of the external driving fields. The realization of this scheme may lead to the efficient combination of quantum storage system with the quantum communication system.

  20. A highly efficient single-photon source based on a quantum dot in a photonic nanowire

    DEFF Research Database (Denmark)

    Claudon, Julien; Bleuse, Joel; Malik, Nitin Singh

    2010-01-01

    The development of efficient solid-state sources of single photons is a major challenge in the context of quantum communication,optical quantum information processing and metrology1. Such a source must enable the implementation of a stable, single-photon emitter, like a colour centre in diamond2...... with carefully tailored ends13. Under optical pumping, we demonstrate a record source efficiency of 0.72, combined with pure single-photon emission. This non-resonant approach also provides broadband spontaneous emission control, thus offering appealing novel opportunities for the development of single-photon......–4 or a semiconductor quantum dot5–7. Achieving a high extraction efficiency has long been recognized as a major issue, and both classical solutions8 and cavity quantum electrodynamics effects have been applied1,9–12. We adopt a different approach, based on an InAs quantum dot embedded in a GaAs photonic nanowire...

  1. Photonics and Web Engineering 2011, International Journal of Electronics and Telecommunication, vol.57, no 3, pp.421-428, September 2011

    CERN Document Server

    Romaniuk, R S

    2011-01-01

    The paper presents a digest of chosen technical work results shown by young researchers from different technical universities in this country during the SPIE-IEEE Wilga 2011 symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics and telecom, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonicselectronics co-design, optoelectronic and electronic systems for telecom, astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also an occasion for young researchers to meet together in a large group (under the patronage of IEEE) spanning the whole country with guests from this part of Europe. A digest of Wilga references is pr...

  2. Spontaneous emission and nonlinear effects in photonic bandgap materials

    Science.gov (United States)

    Fogel, Ishella S.; Bendickson, Jon M.; Tocci, Michael D.; Bloemer, Mark J.; Scalora, Michael; Bowden, Charles M.; Dowling, Jonathan P.

    1998-03-01

    We summarize and review our theoretical and experimental work on spontaneous emission and nonlinear effects in one-dimensional, photonic bandgap (PBG) structures. We present a new result: a method for calculating the normal-mode solutions - and hence the spontaneous emission of embedded emitters - in an arbitrary, linear, lossless, one-dimensional, PBG structure.

  3. Photonic engineering of hybrid metal-organic chromophores

    CERN Document Server

    Busson, Mickaël P; Stout, Brian; Bonod, Nicolas; Wenger, Jérôme; Bidault, Sébastien; 10.1002/anie.201205995

    2012-01-01

    We experimentally demonstrate control of the absorption and emission properties of individual emitters by photonic antennas in suspension. The method results in a new class of water-soluble chromophores with unprecedented photophysical properties, such as short lifetime, low quantum yield but high brightness.

  4. Potential of semiconductor nanowires for single photon sources

    NARCIS (Netherlands)

    Harmand, J.-C.; Liu, L.; Patriarche, G.; Tchernycheva, M.; Akopian, N.; Perinetti, U.; Zwiller, V.

    2009-01-01

    The catalyst-assisted growth of semiconductor nanowires heterostructures offers a very flexible way to design and fabricate single photon emitters. The nanowires can be positioned by organizing the catalyst prior to growth. Single quantum dots can be formed in the core of single nanowires which can

  5. Quantum electrodynamics near a photonic bandgap

    Science.gov (United States)

    Liu, Yanbing; Houck, Andrew A.

    2017-01-01

    Photonic crystals are a powerful tool for the manipulation of optical dispersion and density of states, and have thus been used in applications from photon generation to quantum sensing with nitrogen vacancy centres and atoms. The unique control provided by these media makes them a beautiful, if unexplored, playground for strong-coupling quantum electrodynamics, where a single, highly nonlinear emitter hybridizes with the band structure of the crystal. Here we demonstrate that such a hybridization can create localized cavity modes that live within the photonic bandgap, whose localization and spectral properties we explore in detail. We then demonstrate that the coloured vacuum of the photonic crystal can be employed for efficient dissipative state preparation. This work opens exciting prospects for engineering long-range spin models in the circuit quantum electrodynamics architecture, as well as new opportunities for dissipative quantum state engineering.

  6. Quantum Dots in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Sollner, Immo Nathanael

    This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission...... into the mode exceeding 98% for emitters spectrally close to the band-edge of the waveguide mode. In addition we illustrate the broadband nature of the underlying eects, by obtaining coupling eciencies above 90% for quantum dots detuned from the band edge by as far as 20nm. These values are in good agreement...... quantum-dot-waveguide coupling. Such a structure is ideally suited for a number of applications in quantum information processing and among others we propose an on-chip spin-photon interface, a single photon transistor, and a deterministic cNOT gate....

  7. Coupled external cavity photonic crystal enhanced fluorescence.

    Science.gov (United States)

    Pokhriyal, Anusha; Lu, Meng; Ge, Chun; Cunningham, Brian T

    2014-05-01

    We report a fundamentally new approach to enhance fluorescence in which surface adsorbed fluorophore-tagged biomolecules are excited on a photonic crystal surface that functions as a narrow bandwidth and tunable mirror of an external cavity laser. This scheme leads to ∼10× increase in the electromagnetic enhancement factor compared to ordinary photonic crystal enhanced fluorescence. In our experiments, the cavity automatically tunes its lasing wavelength to the resonance wavelength of the photonic crystal, ensuring optimal on-resonance coupling even in the presence of variable device parameters and variations in the density of surface-adsorbed capture molecules. We achieve ∼10(5) × improvement in the limit of detection of a fluorophore-tagged protein compared to its detection on an unpatterned glass substrate. The enhanced fluorescence signal and easy optical alignment make cavity-coupled photonic crystals a viable approach for further reducing detection limits of optically-excited light emitters that are used in biological assays.

  8. Quantum Dots in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Sollner, Immo Nathanael

    This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission...... into the mode exceeding 98% for emitters spectrally close to the band-edge of the waveguide mode. In addition we illustrate the broadband nature of the underlying eects, by obtaining coupling eciencies above 90% for quantum dots detuned from the band edge by as far as 20nm. These values are in good agreement...... quantum-dot-waveguide coupling. Such a structure is ideally suited for a number of applications in quantum information processing and among others we propose an on-chip spin-photon interface, a single photon transistor, and a deterministic cNOT gate....

  9. A Tunable Waveguide-Coupled Cavity Design for Efficient Spin-Photon Interfaces in Photonic Integrated Circuits

    CERN Document Server

    Mouradian, Sara

    2016-01-01

    A solid state emitter coupled to a photonic crystal cavity exhibits increased photon emission into a single frequency mode. However, current designs for photonic crystal cavities coupled to quantum emitters have three main problems: emitters are placed near surfaces that can degrade their optical properties, the cavity fluorescence cannot be collected into a single useful mode for further routing, and post-fabrication tuning is not currently possible in a stable and reversible manner for each node individually. In this paper, we introduce a hybrid cavity design with minimal fabrication of the host material that keeps the emitter $\\geq100\\,$nm from all surfaces. This cavity has an unloaded quality factor ($Q$) larger than $1\\times10^6$ and a loaded $Q$ of $5.5\\times10^4$ with more than 75% of the emission coupled directly into an underlying photonic integrated circuit built from a convenient material that provides low loss waveguides. Finally this design can be actively and reversibly tuned onto resonance with...

  10. Final LDRD report : enhanced spontaneous emission rate in visible III-nitride LEDs using 3D photonic crystal cavities.

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Arthur Joseph; Subramania, Ganapathi S.; Coley, Anthony J.; Lee, Yun-Ju; Li, Qiming; Wang, George T.; Luk, Ting Shan; Koleske, Daniel David; Fullmer, Kristine Wanta

    2009-09-01

    The fundamental spontaneous emission rate for a photon source can be modified by placing the emitter inside a periodic dielectric structure allowing the emission to be dramatically enhanced or suppressed depending on the intended application. We have investigated the relatively unexplored realm of interaction between semiconductor emitters and three dimensional photonic crystals in the visible spectrum. Although this interaction has been investigated at longer wavelengths, very little work has been done in the visible spectrum. During the course of this LDRD, we have fabricated TiO{sub 2} logpile photonic crystal structures with the shortest wavelength band gap ever demonstrated. A variety of different emitters with emission between 365 nm and 700 nm were incorporated into photonic crystal structures. Time-integrated and time-resolved photoluminescence measurements were performed to measure changes to the spontaneous emission rate. Both enhanced and suppressed emission were demonstrated and attributed to changes to the photonic density of states.

  11. Gold-Coated Nanoelectrospray Emitters Fabricated by Gravity-Assisted Etching Self-Termination and Electroless Deposition.

    Science.gov (United States)

    Zhu, Xudong; Liang, Yu; Weng, Yejing; Chen, Yuanbo; Jiang, Hao; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2016-12-06

    To improve the stability and sensitivity of nanoelectrospray for liquid chromatography-mass spectroscopy (LC-MS) analysis, we present a new method to fabricate gold-coated emitters. Via gravity-assisted etching self-termination, the emitter with a tapered outer surface and a straight inner surface is prepared with good reproducibility, without the need of fluid introduced to protect internal surface during etching. Followed by electroless deposition, the emitter is further coated with gold film homogeneously, by which the relative standard deviation (RSD) value of total ion current in 160 h is <5%, showing good stability. Compared to that obtained by a commercial emitter, the identified protein number from 2 μg HeLa cell digests is increased over 10%, contributed by the stable electrospray and improved signal intensity of peptides. Furthermore, the integrated gold-coated emitter is prepared at the end of the ultranarrow-bore packed column (inner diameter of 25 μm), and 218 proteins are identified from 2 ng HeLa cell digests. All of these results demonstrate the great promise of such emitters for use in ultrasensitive proteome analysis.

  12. Quantum emitters dynamically coupled to a quantum field

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, O. L.; Quiroga, L.; Rodríguez, F. J. [Departamento de Física, Universidad de los Andes, A.A. 4976, Bogotá (Colombia); Johnson, N. F. [Department of Physics, University of Miami, Coral Gables, Miami, FL 33124 (United States)

    2013-12-04

    We study theoretically the dynamical response of a set of solid-state quantum emitters arbitrarily coupled to a single-mode microcavity system. Ramping the matter-field coupling strength in round trips, we quantify the hysteresis or irreversible quantum dynamics. The matter-field system is modeled as a finite-size Dicke model which has previously been used to describe equilibrium (including quantum phase transition) properties of systems such as quantum dots in a microcavity. Here we extend this model to address non-equilibrium situations. Analyzing the system’s quantum fidelity, we find that the near-adiabatic regime exhibits the richest phenomena, with a strong asymmetry in the internal collective dynamics depending on which phase is chosen as the starting point. We also explore signatures of the crossing of the critical points on the radiation subsystem by monitoring its Wigner function; then, the subsystem can exhibit the emergence of non-classicality and complexity.

  13. Quantum emitters dynamically coupled to a quantum field

    Science.gov (United States)

    Acevedo, O. L.; Quiroga, L.; Rodríguez, F. J.; Johnson, N. F.

    2013-12-01

    We study theoretically the dynamical response of a set of solid-state quantum emitters arbitrarily coupled to a single-mode microcavity system. Ramping the matter-field coupling strength in round trips, we quantify the hysteresis or irreversible quantum dynamics. The matter-field system is modeled as a finite-size Dicke model which has previously been used to describe equilibrium (including quantum phase transition) properties of systems such as quantum dots in a microcavity. Here we extend this model to address non-equilibrium situations. Analyzing the system's quantum fidelity, we find that the near-adiabatic regime exhibits the richest phenomena, with a strong asymmetry in the internal collective dynamics depending on which phase is chosen as the starting point. We also explore signatures of the crossing of the critical points on the radiation subsystem by monitoring its Wigner function; then, the subsystem can exhibit the emergence of non-classicality and complexity.

  14. Ghost signals in Allison emittance scanners

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Martin P.; /SNS Project, Oak Ridge /Tennessee U.; Leitner, M.; /LBL, Berkeley; Moehs, D.P.; /Fermilab; Keller, R.; /LBL, Berkeley; Welton, R.F.; /SNS Project, Oak

    2004-12-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%.

  15. Computing Eigen-Emittances from Tracking Data

    CERN Document Server

    Alexahin, Y

    2014-01-01

    In a strongly nonlinear system the particle distribution in the phase space may develop long tails which contribution to the covariance (sigma) matrix should be suppressed for a correct estimate of the beam emittance. A method is offered based on Gaussian approximation of the original particle distribution in the phase space (Klimontovich distribution) which leads to an equation for the sigma matrix which provides efficient suppression of the tails and cannot be obtained by introducing weights. This equation is easily solved by iterations in the multi-dimensional case. It is also shown how the eigen-emittances and coupled optics functions can be retrieved from the sigma matrix in a strongly coupled system. Finally, the developed algorithm is applied to 6D ionization cooling of muons in HFOFO channel.

  16. An ultracold low emittance electron source

    CERN Document Server

    Xia, G; Murray, A J; Bellan, L; Bertsche, W; Appleby, R B; Mete, O; Chattopadhyay, S

    2014-01-01

    Ultracold atom-based electron sources have recently been proposed as an alternative to the conventional photo-injectors or thermionic electron guns widely used in modern particle accelerators. The advantages of ultracold atom-based electron sources lie in the fact that the electrons extracted from the plasma (created from near threshold photo-ionization of ultracold atoms) have a very low temperature, i.e. down to tens of Kelvin. Extraction of these electrons has the potential for producing very low emittance electron bunches. These features are crucial for the next generation of particle accelerators, including free electron lasers, plasma-based accelerators and future linear colliders. The source also has many potential direct applications, including ultrafast electron diffraction (UED) and electron microscopy, due to its intrinsically high coherence. In this paper, the basic mechanism of ultracold electron beam production is discussed and our new research facility for an ultracold, low emittance electron s...

  17. Computing Eigen-Emittances from Tracking Data

    Energy Technology Data Exchange (ETDEWEB)

    Alexahin, Y. [Fermilab

    2014-09-18

    In a strongly nonlinear system the particle distribution in the phase space may develop long tails which contribution to the covariance (sigma) matrix should be suppressed for a correct estimate of the beam emittance. A method is offered based on Gaussian approximation of the original particle distribution in the phase space (Klimontovich distribution) which leads to an equation for the sigma matrix which provides efficient suppression of the tails and cannot be obtained by introducing weights. This equation is easily solved by iterations in the multi-dimensional case. It is also shown how the eigen-emittances and coupled optics functions can be retrieved from the sigma matrix in a strongly coupled system. Finally, the developed algorithm is applied to 6D ionization cooling of muons in HFOFO channel.

  18. Reverse Emittance Exchange for Muon Colliders

    Energy Technology Data Exchange (ETDEWEB)

    V. Ivanov, A. Afanasev, C.M. Ankenbrandt, R.P. Johnson, G.M. Wang, S.A. Bogacz, Y.S. Derbenev

    2009-05-01

    Muon collider luminosity depends on the number of muons in the storage ring and on the transverse size of the beams in collision. Ionization cooling as it is currently envisioned will not cool the beam sizes sufficiently well to provide adequate luminosity without large muon intensities. Six-dimensional cooling schemes will reduce the longitudinal emittance of a muon beam so that smaller high frequency RF cavities can be used for later stages of cooling and for acceleration. However, the bunch length at collision energy is then shorter than needed to match the interaction region beta function. New ideas to shrink transverse beam dimensions by lengthening each bunch will help achieve high luminosity in muon colliders. Analytic expressions for the reverse emittance exchange mechanism were derived, including a new resonant method of beam focusing.

  19. FIrpic: archetypal blue phosphorescent emitter for electroluminescence.

    Science.gov (United States)

    Baranoff, Etienne; Curchod, Basile F E

    2015-05-14

    FIrpic is the most investigated bis-cyclometallated iridium complex in particular in the context of organic light emitting diodes (OLEDs) because of its attractive sky-blue emission, high emission efficiency, and suitable energy levels. In this Perspective we review the synthesis, structural characterisations, and key properties of this emitter. We also survey the theoretical studies and summarise a series of selected monochromatic electroluminescent devices using FIrpic as the emitting dopant. Finally we highlight important shortcomings of FIrpic as an emitter for OLEDs. Despite the large body of work dedicated to this material, it is manifest that the understanding of photophysical and electrochemical processes are only broadly understood mainly because of the different environment in which these properties are measured, i.e., isolated molecules in solvent vs. device.

  20. ITMO Photonics: center of excellence

    Science.gov (United States)

    Voznesenskaya, Anna; Bougrov, Vladislav; Kozlov, Sergey; Vasilev, Vladimir

    2016-09-01

    ITMO University, the leading Russian center in photonics research and education, has the mission to train highlyqualified competitive professionals able to act in conditions of fast-changing world. This paradigm is implemented through creation of a strategic academic unit ITMO Photonics, the center of excellence concentrating organizational, scientific, educational, financial, laboratory and human resources. This Center has the following features: dissemination of breakthrough scientific results in photonics such as advanced photonic materials, ultrafast optical and quantum information, laser physics, engineering and technologies, into undergraduate and graduate educational programs through including special modules into the curricula and considerable student's research and internships; transformation of the educational process in accordance with the best international educational practices, presence in the global education market in the form of joint educational programs with leading universities, i.e. those being included in the network programs of international scientific cooperation, and international accreditation of educational programs; development of mechanisms for the commercialization of innovative products - results of scientific research; securing financial sustainability of research in the field of photonics of informationcommunication systems via funding increase and the diversification of funding sources. Along with focusing on the research promotion, the Center is involved in science popularization through such projects as career guidance for high school students; interaction between student's chapters of international optical societies; invited lectures of World-famous experts in photonics; short educational programs in optics, photonics and light engineering for international students; contests, Olympics and grants for talented young researchers; social events; interactive demonstrations.

  1. Emittance growths in resonance crossing at FFAGs

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.Y.; /Fermilab; Pang, X.; Wang, F.; Wang, X.; Lee, S.Y.; /Indiana U.

    2007-10-01

    Scaling laws of the emittance growth for a beam crossing the 6th-order systematic space-charge resonances and the random-octupole driven 4th-order resonance are obtained by numerical multi-particle simulations. These laws can be important in setting the minimum acceleration rate and maximum tolerable resonance strength for the design of non-scaling fixed-field alternating gradient accelerators.

  2. Large-area lanthanum hexaboride electron emitter

    Science.gov (United States)

    Goebel, D. M.; Hirooka, Y.; Sketchley, T. A.

    1985-09-01

    The characteristics of lanthanum-boron thermionic electron emitters are discussed, and a large-area, continuously operating cathode assembly and heater are described. Impurity production and structural problems involving the support of the LaB6 have been eliminated in the presented configuration. The performance of the cathode in a plasma discharge, where surface modification occurs by ion sputtering, is presented. Problem areas which affect lifetime and emission current capability are discussed.

  3. Studying Reionization with Ly-alpha Emitters

    CERN Document Server

    McQuinn, Matthew; Zaldarriaga, Matias; Dutta, Suvendra

    2007-01-01

    We show that observations of high-redshift Ly-alpha emitters (LAEs) have the potential to provide definitive evidence for reionization in the near future. Using 200 Mpc radiative transfer simulations, we calculate the effect that patchy reionization has on the line profile, on the luminosity function, and, most interestingly, on the clustering of emitters for several realistic models of reionization. Reionization increases the measured clustering of emitters, and we show that this enhancement would be essentially impossible to attribute to anything other than reionization. Our results motivate looking for the signature of reionization in existing LAE data. We find that for stellar reionization scenarios the angular correlation function of the 58 LAEs in the Subaru Deep Field z = 6.6 photometric sample is more consistent with a fully ionized universe (mean volume ionized fraction x_i = 1) than a universe with x_i 2-sigma confidence level. Measurements in the next year on Subaru will increase their z = 6.6 LAE ...

  4. Photonic Hypercrystals

    Directory of Open Access Journals (Sweden)

    Evgenii E. Narimanov

    2014-10-01

    Full Text Available We introduce a new “universality class” of artificial optical media—photonic hypercrystals. These hyperbolic metamaterials, with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hypercrystal possess the properties of both the optical Tamm states in photonic crystals and surface-plasmon polaritons at the metal-dielectric interface.

  5. Photonic Lantern

    CERN Document Server

    Leon-Saval, Sergio; Bland-Hawthorn, Joss

    2015-01-01

    Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus, enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail.

  6. Theory of antibunching of photon emission I.

    Science.gov (United States)

    Seki, Kazuhiko; Tachiya, M

    2009-01-14

    The photon emission statistics from a single molecule containing multichromophores under pulsed excitation is theoretically studied. Fast nonradiative pair annihilation of excitons efficiently produces a single exciton, which acts as a single photon emitter. By taking into account the discrete nature of exciton numbers and the competition among pair annihilation, and unimolecular radiative and nonradiative decay of excitons, we obtain analytical expressions of photon emission statistics, the average number of emitted photons, and the normalized photon pair correlation which represents the ratio of the number of photon pairs created by the same pulse to that created by different pulses. The normalized photon pair correlation is influenced by the ratio of the pair annihilation rate to the total unimolecular decay rate including both radiative and nonradiative processes but is not influenced by the ratio of the unimolecular radiative and nonradiative rates. On the other hand, the single photon emission intensity depends on the ratio of the unimolecular radiative and nonradiative rates from the exciton left alone after pair annihilation. The conclusion is consistent with recent experimental results on conjugated polymers with various sizes in different host materials.

  7. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  8. Lyman Alpha Emitters in the Hierarchically Clustering Galaxy Formation

    CERN Document Server

    Kobayashi, Masakazu A R; Nagashima, Masahiro

    2007-01-01

    We present a new theoretical model for the luminosity functions (LFs) of Lyman alpha (Lya) emitting galaxies in the framework of hierarchical galaxy formation. We extend a semi-analytic model of galaxy formation that reproduces a number of observations for local galaxies, without changing the original model parameters but introducing a physically-motivated modelling to describe the escape fraction of Lya photons from host galaxies (f_esc). Though a previous study using a hierarchical clustering model simply assumed a constant and universal value of f_esc, we incorporate two new effects on f_esc: extinction by interstellar dust and galaxy-scale outflow induced as a star formation feedback. It is found that the new model nicely reproduces all the observed Lya LFs of the Lya emitters (LAEs) at different redshifts in z ~ 3--6. Our model predicts that galaxies with strong outflows and f_esc ~ 1 are dominant in the observed LFs, which is consistent with available observations while the simple universal f_esc model ...

  9. Emissivity Tuned Emitter for RTPV Power Sources

    Energy Technology Data Exchange (ETDEWEB)

    Carl M. Stoots; Robert C. O' Brien; Troy M. Howe

    2012-03-01

    Every mission launched by NASA to the outer planets has produced unexpected results. The Voyager I and II, Galileo, and Cassini missions produced images and collected scientific data that totally revolutionized our understanding of the solar system and the formation of the planetary systems. These missions were enabled by the use of nuclear power. Because of the distances from the Sun, electrical power was produced using the radioactive decay of a plutonium isotope. Radioisotopic Thermoelectric Generators (RTGs) used in the past and currently used Multi-Mission RTGs (MMRTGs) provide power for space missions. Unfortunately, RTGs rely on thermocouples to convert heat to electricity and are inherently inefficient ({approx} 3-7% thermal to electric efficiency). A Radioisotope Thermal Photovoltaic (RTPV) power source has the potential to reduce the specific mass of the onboard power supply by increasing the efficiency of thermal to electric conversion. In an RTPV, a radioisotope heats an emitter, which emits light to a photovoltaic (PV) cell, which converts the light into electricity. Developing an emitter tuned to the desired wavelength of the photovoltaic is a key part in increasing overall performance. Researchers at the NASA Glenn Research Center (GRC) have built a Thermal Photovoltaic (TPV) system, that utilizes a simulated General Purpose Heat Source (GPHS) from a MMRTG to heat a tantalum emitter. The GPHS is a block of graphite roughly 10 cm by 10 cm by 5 cm. A fully loaded GPHS produces 250 w of thermal power and weighs 1.6 kgs. The GRC system relies on the GPHS unit radiating at 1200 K to a tantalum emitter that, in turn, radiates light to a GaInAs photo-voltaic cell. The GRC claims system efficiency of conversion of 15%. The specific mass is around 167 kg/kWe. A RTPV power source that utilized a ceramic or ceramic-metal (cermet) matrix would allow for the combination of the heat source, canister, and emitter into one compact unit, and allow variation in size

  10. Optimizing photon indistinguishability in the emission from incoherently-excited semiconductor quantum dots

    OpenAIRE

    F. Troiani; Perea, J. I.; Tejedor, C.

    2005-01-01

    Most optical quantum devices require deterministic single-photon emitters. Schemes so far demonstrated in the solid state imply an energy relaxation which tends to spoil the coherent nature of the time evolution, and with it the photon indistinguishability. We focus our theoretical investigation on semiconductor quantum dots embedded in microcavities. Simple and general relations are identified between the photon indistinguishability and the collection efficiency. The identification of the ke...

  11. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Thomas, E-mail: thomas.hofmann@cern.ch [CERN, Geneva 1211 (Switzerland); John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Friedrich-Alexander-University, Erlangen 91054 (Germany); Boorman, Gary E.; Bosco, Alessio [John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Bravin, Enrico [CERN, Geneva 1211 (Switzerland); Gibson, Stephen M.; Kruchinin, Konstantin O. [John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Raich, Uli; Roncarolo, Federico; Zocca, Francesca [CERN, Geneva 1211 (Switzerland)

    2016-09-11

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H{sup −} ions to 160 MeV. To measure the transverse emittance of the H{sup −} beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused onto the H{sup −} beam. The laser photons have sufficient energy to detach the outer electron and create H{sup 0}/e{sup −} pairs. In a downstream dipole, the created H{sup 0} particles are separated from the unstripped H{sup −} ions and their distribution is measured with a dedicated detector. By scanning the focused laser beam across the H{sup −} beam, the transverse emittance of the H{sup −} beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser emittance scanner and then present results from a prototype system used during the 12 MeV commissioning of the LINAC4.

  12. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    Science.gov (United States)

    Hofmann, Thomas; Boorman, Gary E.; Bosco, Alessio; Bravin, Enrico; Gibson, Stephen M.; Kruchinin, Konstantin O.; Raich, Uli; Roncarolo, Federico; Zocca, Francesca

    2016-09-01

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H- ions to 160 MeV. To measure the transverse emittance of the H- beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused onto the H- beam. The laser photons have sufficient energy to detach the outer electron and create H0/e- pairs. In a downstream dipole, the created H0 particles are separated from the unstripped H- ions and their distribution is measured with a dedicated detector. By scanning the focused laser beam across the H- beam, the transverse emittance of the H- beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser emittance scanner and then present results from a prototype system used during the 12 MeV commissioning of the LINAC4.

  13. Possible operation of the European XFEL with ultra-low emittance beams

    CERN Document Server

    Brinkmann, R; Yurkov, M V

    2010-01-01

    Recent successful lasing of the Linac Coherent Light Source (LCLS) in the hard x-ray regime and the experimental demonstration of a possibility to produce low-charge bunches with ultra-small normalized emittance have lead to the discussions on optimistic scenarios of operation of the European XFEL. In this paper we consider new options that make use of low-emittance beams, a relatively high beam energy, tunable-gap undulators, and a multi-bunch capability of this facility. We study the possibility of operation of a spontaneous radiator (combining two of them, U1 and U2, in one beamline) in the SASE mode in the designed photon energy range 20-90 keV and show that it becomes possible with ultra-low emittance electron beams similar to those generated in LCLS. As an additional attractive option we consider the generation of powerful soft x-ray and VUV radiation by the same electron bunch for pump-probe experiments, making use of recently invented compact afterburner scheme. We also propose a betatron switcher as ...

  14. Towards the ultimate storage ring: the lattice design for Beijing Advanced Photon Source

    CERN Document Server

    Gang, Xu

    2013-01-01

    A storage ring-based light source, Beijing Advanced Photon Source (BAPS) is proposed to store 5-GeV low-emittance electron beam and to provide high-brilliance coherent radiation. In this paper, we report our efforts of pushing down the emittance of BAPS to approach the so-called ultimate storage ring, while fixing the circumference to about 1200 m. To help dealing with the challenge of beam dynamics associated with the intrinsic very strong nonlinearities in an ultralow-emittance ring, a combination of several progressive technologies is used in the linear optics design and nonlinear optimization, such as modified theoretical minimum emittance cell with small-aperture magnets, quasi-3rd-order achromat, theoretical analyzer based on Lie Algebra and Hamiltonian analysis, multi-objective genetic algorithm, and frequency map analysis. These technologies enable us to obtain satisfactory beam dynamics in one lattice design with natural emittance of 75 pm.

  15. Development of mathematical pediatric phantoms for internal dose calculations: designs, limitations, and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, M.

    1980-01-01

    Mathematical phantoms of the human body at various ages are employed with Monte Carlo radiation transport codes for calculation of photon specific absorbed fractions. The author has developed a pediatric phantom series based on the design of the adult phantom, but with explicit equations for each organ so that organ sizes and marrow distributions could be assigned properly. Since the phantoms comprise simple geometric shapes, predictive dose capability is limited when geometry is critical to the calculation. Hence, there is a demand for better phantom design in situations where geometry is critical, such as for external irradiation or for internal emitters with low energy photons. Recent advances in computerized axial tomography (CAT) present the potential for derivation of anatomical information, which is so critical to development of phantoms, and ongoing developmental work on compuer architecture to handle large arrays for Monte Carlo calculations should make complex-geometry dose calculations economically feasible within this decade.

  16. Wavelength locking of single emitters and multi-emitter modules: simulation and experiments

    Science.gov (United States)

    Yanson, Dan; Rappaport, Noam; Peleg, Ophir; Berk, Yuri; Dahan, Nir; Klumel, Genady; Baskin, Ilya; Levy, Moshe

    2016-03-01

    Wavelength-stabilized high-brightness single emitters are commonly used in fiber-coupled laser diode modules for pumping Yb-doped lasers at 976 nm, and Nd-doped ones at 808 nm. We investigate the spectral behavior of single emitters under wavelength-selective feedback from a volume Bragg (or hologram) grating (VBG) in a multi-emitter module. By integrating a full VBG model as a multi-layer thin film structure with commercial raytracing software, we simulated wavelength locking conditions as a function of beam divergence and angular alignment tolerances. Good correlation between the simulated VBG feedback strength and experimentally measured locking ranges, in both VBG misalignment angle and laser temperature, is demonstrated. The challenges of assembling multi-emitter modules based on beam-stacked optical architectures are specifically addressed, where the wavelength locking conditions must be achieved simultaneously with high fiber coupling efficiency for each emitter in the module. It is shown that angular misorientation between fast and slow-axis collimating optics can have a dramatic effect on the spectral and power performance of the module. We report the development of our NEON-S wavelength-stabilized fiber laser pump module, which uses a VBG to provide wavelength-selective optical feedback in the collimated portion of the beam. Powered by our purpose-developed high-brightness single emitters, the module delivers 47 W output at 11 A from an 0.15 NA fiber and a 0.3 nm linewidth at 976 nm. Preliminary wavelength-locking results at 808 nm are also presented.

  17. Delay modeling of bipolar ECL/EFL (Emitter-Coupled Logic/Emitter-Follower-Logic) circuits

    Science.gov (United States)

    Yang, Andrew T.

    1986-08-01

    This report deals with the development of a delay-time model for timing simulation of large circuits consisting of Bipolar ECL(Emitter-Coupled Logic) and EFL (Emitter-Follower-Logic) networks. This model can provide adequate information on the performance of the circuits with a minimum expenditure of computation time. This goal is achieved by the use of proper circuit transient models on which analytical delay expressions can be derived with accurate results. The delay-model developed in this report is general enough to handle complex digital circuits with multiple inputs or/and multiple levels. The important effects of input slew rate are also included in the model.

  18. The photonic nanowire: an emerging platform for highly efficient single-photon sources for quantum information applications

    DEFF Research Database (Denmark)

    Gregersen, Niels; Munsch, Mathieu; Malik, Nitin S.

    2013-01-01

    Efficient coupling between a localized quantum emitter and a well defined optical channel represents a powerful route to realize single-photon sources and spin-photon interfaces. The tailored fiber-like photonic nanowire embedding a single quantum dot has recently demonstrated an appealing potent....... A first implementation of this strategy has lead to an ultra-bright single-photon source with a first-lens external efficiency of 0.75 ± 0.1 and a predicted coupling to a Gaussian beam of 0.61 ± 0.08.......Efficient coupling between a localized quantum emitter and a well defined optical channel represents a powerful route to realize single-photon sources and spin-photon interfaces. The tailored fiber-like photonic nanowire embedding a single quantum dot has recently demonstrated an appealing...... potential. However, the device requires a delicate, sharp needle-like taper with performance sensitive to minute geometrical details. To overcome this limitation we demonstrate the photonic trumpet, exploiting an opposite tapering strategy. The trumpet features a strongly Gaussian far-field emission...

  19. Scalable Focused Ion Beam Creation of Nearly Lifetime-Limited Single Quantum Emitters in Diamond Nanostructures

    CERN Document Server

    Schröder, Tim; Walsh, Michael; Li, Luozhou; Zheng, Jiabao; Schukraft, Marco; Pacheco, Jose L; Camacho, Ryan M; Bielejec, Edward S; Sipahigil, Alp; Evans, Ruffin E; Sukachev, Denis D; Nguyen, Christian T; Lukin, Mikhail D; Englund, Dirk

    2016-01-01

    The controlled creation of defect center---nanocavity systems is one of the outstanding challenges for efficiently interfacing spin quantum memories with photons for photon-based entanglement operations in a quantum network. Here, we demonstrate direct, maskless creation of atom-like single silicon-vacancy (SiV) centers in diamond nanostructures via focused ion beam implantation with $\\sim 32$ nm lateral precision and $< 50$ nm positioning accuracy relative to a nanocavity. Moreover, we determine the Si+ ion to SiV center conversion yield to $\\sim 2.5\\%$ and observe a 10-fold conversion yield increase by additional electron irradiation. We extract inhomogeneously broadened ensemble emission linewidths of $\\sim 51$ GHz, and close to lifetime-limited single-emitter transition linewidths down to $126 \\pm13$ MHz corresponding to $\\sim 1.4$-times the natural linewidth. This demonstration of deterministic creation of optically coherent solid-state single quantum systems is an important step towards development o...

  20. Near-unity efficiency, single-photon sources based on tapered photonic nanowires

    DEFF Research Database (Denmark)

    Bleuse, Joël; Munsch, Mathieu; Claudon, Julien

    2012-01-01

    Single-photon emission from excitons in InAs Quantum Dots (QD) embedded in GaAs Tapered Photonic Wires (TPW) already demonstrated a 0.72 collection efficiency, with TPWs were the apex is the sharp end of the cone. Going to alternate designs, still based on the idea of the adiabatic deconfinement ...... of the quasi-Gaussian emission mode, but with inverted TPW where the apex is the cone's base, leads to even larger efficiencies. In addition, these inverted TPWs make the electric pumping of the emitters compatible with these large efficiencies....

  1. Radar Emitter Signal Recognition Based on Complexity Features

    Institute of Scientific and Technical Information of China (English)

    张葛祥; 金炜东; 胡来招

    2004-01-01

    Intra-pulse characteristics of different radar emitter signals reflect on signal waveform by way of changing frequency, phase and amplitude. A novel approach was proposed to extract complexity features of radar emitter signals in a wide range of signal-to-noise ratio ( SNR), and radial basis probability neural network (RBPNN) was used to recognize different radar emitter signals. Complexity features, including Lempel-Ziv complexity (LZC) and correlation dimension (CD), can measure the complexity and irregularity of signals, which mirrors the intra-pulse modulation laws of radar emitter signals. In an experiment, LZC and CD features of 10 typical radar emitter signals were extracted and RBPNN was applied to identify the 10 radar emitter signals. Simulation results show that the proposed approach is effective and has good application values because average accurate recognition rate is high when SNR varies in a wide range.

  2. Semiconductor Quantum Dash Broadband Emitters: Modeling and Experiments

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-10-01

    Broadband light emitters operation, which covers multiple wavelengths of the electromagnetic spectrum, has been established as an indispensable element to the human kind, continuously advancing the living standard by serving as sources in important multi-disciplinary field applications such as biomedical imaging and sensing, general lighting and internet and mobile phone connectivity. In general, most commercial broadband light sources relies on complex systems for broadband light generation which are bulky, and energy hungry. \\tRecent demonstration of ultra-broadband emission from semiconductor light sources in the form of superluminescent light emitting diodes (SLDs) has paved way in realization of broadband emitters on a completely novel platform, which offered compactness, cost effectiveness, and comparatively energy efficient, and are already serving as a key component in medical imaging systems. The low power-bandwidth product is inherent in SLDs operating in the amplified spontaneous emission regime. A quantum leap in the advancement of broadband emitters, in which high power and large bandwidth (in tens of nm) are in demand. Recently, the birth of a new class of broadband semiconductor laser diode (LDs) producing multiple wavelength light in stimulated emission regime was demonstrated. This very recent manifestation of a high power-bandwidth-product semiconductor broadband LDs relies on interband optical transitions via quantum confined dot/dash nanostructures and exploiting the natural inhomogeneity of the self-assembled growth technology. This concept is highly interesting and extending the broad spectrum of stimulated emission by novel device design forms the central focus of this dissertation. \\tIn this work, a simple rate equation numerical technique for modeling InAs/InP quantum dash laser incorporating the properties of inhomogeneous broadening effect on lasing spectra was developed and discussed, followed by a comprehensive experimental analysis

  3. Deterministic coupling of a single nitrogen vacancy center to a photonic crystal cavity

    CERN Document Server

    Englund, Dirk; Rivoire, Kelley; Hatami, Fariba; Vuckovic, Jelena; Park, Hongkun; Lukin, Mikhail D

    2010-01-01

    We describe and experimentally demonstrate a technique for deterministic coupling between a photonic crystal (PC) nanocavity and single emitters. The technique is based on in-situ scanning of a PC cavity over a sample and allows the positioning of the cavity over a desired emitter with nanoscale resolution. The power of the technique, which we term a Scanning Cavity Microscope (SCM), is demonstrated by coupling the PC nanocavity to a single nitrogen vacancy (NV) center in diamond, an emitter system that provides optically accessible electron and nuclear spin qubits.

  4. A novel high-efficiency single-mode quantum dot single photon source

    DEFF Research Database (Denmark)

    Gerard, J.M.; Gregersen, Niels; Nielsen, Torben Roland

    2008-01-01

    We present a novel single-mode single photon source exploiting the emission of a semiconductor quantum dot (QD) located inside a photonic wire. Besides an excellent coupling (>95%) of QD spontaneous emission to the fundamental guided mode [1], we show that a single photon collection efficiency...... above 80% within a 0.5 numerical aperture can be achieved using a bottom Bragg mirror and a tapering of the nanowire tip. Because this photon collection strategy does not exploit the Purcell effect, it could also be efficiently applied to broadband single photon emitters such as F-centers in diamond....

  5. A wavelength tunable photon source with sealed inner volume

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented a method of providing a wavelength tunable photon source (200), comprising bonding a first element (101) with a first mirror (106), a second element (102) with a second mirror (108) and a third element (103) with a photon emitter together in a structure enclosing an inner volume...... (214) being a sealed volume, and forming a bonding interface (212) which is gas-tight, so that the first mirror (106) is placed in the inner volume (214) so the first mirror (106) may move within the inner volume (214). The method provides a relatively simple way of obtaining a tunable photon source...

  6. Coated nano-particle jamming of quantum emitters

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Ziolkowski, Richard W.

    2012-01-01

    Spherical active coated nano-particles are examined analytically and numerically in the presence of one, two or four quantum emitters (electric Hertzian dipoles). The ability of the coated nano-particle to effectively cloak the emitters to a far-field observer is reported. This offers an interest...... an interesting route towards the jamming of quantum emitters/nano-antennas, for instance, in biological fluorescence assays....

  7. Thermal emittance measurements of a cesium potassium antimonide photocathode

    Science.gov (United States)

    Bazarov, Ivan; Cultrera, Luca; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Li, Yulin; Liu, Xianghong; Maxson, Jared; Roussel, William

    2011-05-01

    Thermal emittance measurements of a CsK2Sb photocathode at several laser wavelengths are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. The thermal emittance is 0.56±0.03 mm mrad/mm(rms) at 532 nm wavelength. The results are compared with a simple photoemission model and found to be in a good agreement.

  8. Thermal emittance measurements of a cesium potassium antimonide photocathode

    CERN Document Server

    Bazarov, Ivan; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Li, Yulin; Liu, Xianghong; Maxson, Jared; Roussel, William

    2011-01-01

    Thermal emittance measurements of a CsK2Sb photocathode at several laser wavelengths are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. The thermal emittance is 0.56+/-0.03 mm-mrad/mm(rms) at 532 nm wavelength. The results are compared with a simple photoemission model and found to be in a good agreement.

  9. Intelligent Variable Emittance Panels Using New, ""True"" Solid Electrolyte Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This work further developed a highly promising Variable Emittance technology for spacecraft thermal control based on Conducting Polymer (CP) electrochromics...

  10. Minimum emittance in storage rings with uniform or nonuniform dipoles

    Directory of Open Access Journals (Sweden)

    Chun-xi Wang

    2009-06-01

    Full Text Available A simple treatment of minimum emittance theory in storage rings is presented, favoring vector and matrix forms for a more concise picture. Both conventional uniform dipoles and nonuniform dipoles with bending radius variation are treated. Simple formulas are given for computing the minimum emittance, optimal lattice parameters, as well as effects of nonoptimal parameters. For nonuniform dipoles, analytical results are obtained for a three-piece sandwich dipole model. Minimization of the effective emittance for light sources is given in detail. Usefulness of gradient and/or nonuniform dipoles for reducing the effective emittance is addressed.

  11. High efficiency quasi-monochromatic infrared emitter

    Science.gov (United States)

    Brucoli, Giovanni; Bouchon, Patrick; Haïdar, Riad; Besbes, Mondher; Benisty, Henri; Greffet, Jean-Jacques

    2014-02-01

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  12. Stroing single-photons in microcavities arrays

    Science.gov (United States)

    Mirza, Imran M.; Enk, S. J. Van; Kimble, H. J.

    2014-03-01

    Coupling light to arrays of microcavities is one of the most promising avenues to store/delay classical light pulses [F. Krauss, Nat. Phot. 2, 448-450 (2008)]. However, from the perspective of benefiting quantum communication protocols, the same ideas in principle can be extended down to the single-photon (quantum) level as well. Particularly, for the purposes of entanglement purification and quantum repeaters a reliable storage of single photons is needed. We consider in our work [I. M. Mirza, S. Van Enk, H. Kimble JOSA B, 30,10 (2013)] cavities that are coupled through an optical fiber which is assumed to be forming a Markovian bath. For this study two powerful open quantum system techniques, Input-Output theory for cascaded quantum systems and the Quantum Trajectory approach are used in combination. For the confirmation of photon delays the Time-Dependent Spectrum of such a single photon is obtained. Interestingly this leads to a hole-burning effect showing that only certain frequency components in the single photon wavepackets are stored inside the cavities and hence are delayed in time. Since on-demand production of single photons is not an easy task we include in our description the actual generation of the single photon by assuming a single emitter in one the resonators.

  13. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  14. Combining surface plasmonic and light extraction enhancement on InGaN quantum-well light-emitters

    DEFF Research Database (Denmark)

    Fadil, Ahmed; Ou, Yiyu; Iida, Daisuke

    2016-01-01

    Surface plasmon coupling with light-emitters and surface nano-patterning have widely been used separately to improve low efficiency InGaN light-emitting diodes. We demonstrate a method where dielectric nano-patterning and Ag nanoparticles (NPs) are combined to provide both light extraction...... and internal quantum efficiency enhancement for InGaN/GaN quantum-well light-emitters. By fabricating dielectric nano-rod pattern on the GaN surface, an optical coating that improves the light extraction is obtained, and furthermore has a low refractive index which blue-shifts the plasmonic resonance of Ag NPs...

  15. Ratios between effective doses for tomographic and mathematician models due to internal exposure of photons; Razoes entre doses efetivas para modelos tomograficos e modelos matematicos devido as exposicoes internas de fotons

    Energy Technology Data Exchange (ETDEWEB)

    Lima, F.R.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Kramer, R.; Khoury, H.J.; Santos, A.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Vieira, W. [Centro Federal de Educacao Tecnologica de Pernambuco (CEFET-PE), Recife, PE (Brazil); Loureiro, E.C.M. [Escola Politecnica de Pernambuco, Recife, PE (Brazil)

    2005-07-01

    The development of new and sophisticated Monte Carlo codes and tomographic human phantoms or voxels motivated the International Commission on Radiological Protection (ICRP) to revise the traditional models of exposure, which have been used to calculate effective dose coefficients for organs and tissues based on mathematician phantoms known as MIRD5. This paper shows the results of calculations using tomographic phantoms MAX (Male Adult voXel) and FAX (Female Adult voXel), recently developed by the authors as well as with the phantoms ADAM and EVA, of specific genres, type MIRD5, coupled to the EGS4 Monte Carlo and MCNP4C codes, for internal exposure with photons of energies between 10 keV and 4 MeV to several organs sources. Effective Doses for both models, tomographic and mathematician, will be compared separately as a function of the Monte Carlo code replacement, of compositions of human tissues and the anatomy reproduced through tomographs. The results indicate that for photon internal exposure, the use of models of exposure based in voxel, increases the values of effective doses up to 70% for some organs sources considered in this study, when compared with the corresponding results obtained with phantoms of MIRD-5 type.

  16. Photon physics: from wave mechanics to quantum electrodynamics

    Science.gov (United States)

    Keller, Ole

    2009-05-01

    When rewritten in an appropriate manner, the microscopic Maxwell-Lorentz equations appear as a wave-mechanical theory for photons, and their quantum physical interaction with matter. A natural extension leads from photon wave mechanics to quantum electrodynamics (QED). In its modern formulation photon wave mechanics has given us valuable new insight in subjects such as spatial photon localization, near-field photon dynamics, transverse photon mass, photon eikonal theory, photon tunneling, and rim-zone electrodynamics. The present review is based on my plenary lecture at the SPIE-Europe 2009 Optics and Optoelectronics International Symposium in Prague.

  17. Muon Emittance Exchange with a Potato Slicer

    CERN Document Server

    Summers, D J; Acosta, J G; Cremaldi, L M; Oliveros, S J; Perera, L P; Neuffer, D V

    2015-01-01

    We propose a novel scheme for final muon ionization cooling with quadrupole doublets followed by emittance exchange in vacuum to achieve the small beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized transverse, longitudinal, and angular momentum emittances of 0.100, 2.5, and 0.200 mm-rad are exchanged into 0.025, 70, and 0.0 mm-rad. A skew quadrupole triplet transforms a round muon bunch with modest angular momentum into a flat bunch with no angular momentum. Thin electrostatic septa efficiently slice the flat bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 microseconds, one quarter of a synchrotron oscillation period. A linear long ...

  18. Muon Emittance Exchange with a Potato Slicer

    Energy Technology Data Exchange (ETDEWEB)

    Summers, D. J. [Univ. of Mississippi, Oxford, MS (United States); Hart, T. L. [Univ. of Mississippi, Oxford, MS (United States); Acosta, J. G. [Univ. of Mississippi, Oxford, MS (United States); Cremaldi, L. M. [Univ. of Mississippi, Oxford, MS (United States); Oliveros, S. J. [Univ. of Mississippi, Oxford, MS (United States); Perera, L. P. [Univ. of Mississippi, Oxford, MS (United States); Neuffer, D. V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-04-15

    We propose a novel scheme for final muon ionization cooling with quadrupole doublets followed by emittance exchange in vacuum to achieve the small beam sizes needed by a muon collider. A flat muon beam with a series of quadrupole doublet half cells appears to provide the strong focusing required for final cooling. Each quadrupole doublet has a low beta region occupied by a dense, low Z absorber. After final cooling, normalized transverse, longitudinal, and angular momentum emittances of 0.100, 2.5, and 0.200 mm-rad are exchanged into 0.025, 70, and 0.0 mm-rad. A skew quadrupole triplet transforms a round muon bunch with modest angular momentum into a flat bunch with no angular momentum. Thin electrostatic septa efficiently slice the flat bunch into 17 parts. The 17 bunches are interleaved into a 3.7 meter long train with RF deflector cavities. Snap bunch coalescence combines the muon bunch train longitudinally in a 21 GeV ring in 55 µs, one quarter of a synchrotron oscillation period. A linear long wavelength RF bucket gives each bunch a different energy causing the bunches to drift in the ring until they merge into one bunch and can be captured in a short wavelength RF bucket with a 13% muon decay loss and a packing fraction as high as 87 %.

  19. Therapeutic use of alpha-emitters

    Energy Technology Data Exchange (ETDEWEB)

    Lassmann, M. [Klinik und Poliklinik fuer Nuklearmedizin der Univ. Wuerzburg (Germany)

    2005-07-01

    In recent years there is a growing interest in the therapeutic use of {alpha}-emitters for patient treatment, {alpha}-particles have much higher energy and their range is only a few cell diameters. Their high LET and the limited ability of cells to repair DNA damage from {alpha}-radiation explain their high relative biological effectiveness and cytotoxicity. Potential {alpha}-emitting isotopes for therapeutic applications are {sup 224}Ra, {sup 223}Ra, {sup 213}Bi and {sup 211}At. The treatment with {alpha}-particles is focused upon targeted cancer therapy using radiolabeled monoclonal antibodies, on palliation of bone metastases or upon pain relief in patients with ankylosing spondylitis (AS). Examples for targeted cancer therapy are the treatment of melanoma with {sup 213}Bi and non-Hodgkin lymphoma with {sup 211}At. For metastatic bone pain palliation {sup 223}Ra was applied in a phase I clinical trial. For amelioration of pain in AS-patients {sup 224}Ra-chloride is used. This radiopharmaceutical is licensed for this particular application in Germany. Today there are some potential clinical applications for {alpha}-emitters although most of them are in the state of scientific, non-routine investigations. In-vivo dosimetry for risk assessment associated with this treatment is even more difficult to perform than for therapies using beta-emitting radiopharmaceuticals. (orig.)

  20. Barium depletion in hollow cathode emitters

    Energy Technology Data Exchange (ETDEWEB)

    Polk, James E., E-mail: james.e.polk@jpl.nasa.gov; Mikellides, Ioannis G.; Katz, Ira [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States); Capece, Angela M. [Graduate Aerospace Laboratories, California Institute of Technology, Pasadena, California 91125 (United States)

    2016-01-14

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al{sub 2}O{sub 3} source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  1. Photonics for life.

    Science.gov (United States)

    Cubeddu, Rinaldo; Bassi, Andrea; Comelli, Daniela; Cova, Sergio; Farina, Andrea; Ghioni, Massimo; Rech, Ivan; Pifferi, Antonio; Spinelli, Lorenzo; Taroni, Paola; Torricelli, Alessandro; Tosi, Alberto; Valentini, Gianluca; Zappa, Franco

    2011-01-01

    Light is strictly connected with life, and its presence is fundamental for any living environment. Thus, many biological mechanisms are related to light interaction or can be evaluated through processes involving energy exchange with photons. Optics has always been a precious tool to evaluate molecular and cellular mechanisms, but the discovery of lasers opened new pathways of interactions of light with biological matter, pushing an impressive development for both therapeutic and diagnostic applications in biomedicine. The use of light in different fields has become so widespread that the word photonics has been utilized to identify all the applications related to processes where the light is involved. The photonics area covers a wide range of wavelengths spanning from soft X-rays to mid-infrared and includes all devices related to photons as light sources, optical fibers and light guides, detectors, and all the related electronic equipment. The recent use of photons in the field of telecommunications has pushed the technology toward low-cost, compact, and efficient devices, making them available for many other applications, including those related to biology and medicine where these requirements are of particular relevance. Moreover, basic sciences such as physics, chemistry, mathematics, and electronics have recognized the interdisciplinary need of biomedical science and are translating the most advanced researches into these fields. The Politecnico school has pioneered many of them,and this article reviews the state of the art of biomedical research at the Politecnico in the field internationally known as biophotonics.

  2. Hallo photons calls photon; Allo photon appelle photon

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-09-01

    When a pair of photons is created, it seems that these 2 photons are bound together by a mysterious link. This phenomenon has been discovered at the beginning of the seventies. In this new experiment the 2 photons are separated and have to follow different ways through optic cables until they face a quantum gate. At this point they have to chose between a short and a long itinerary. Statistically they have the same probability to take either. In all cases the 2 photons agree to do the same choice even if the 2 quantum gates are distant of about 10 kilometers. Some applications in ciphering and coding of messages are expected. (A.C.)

  3. Group-III Nitride Field Emitters

    Science.gov (United States)

    Bensaoula, Abdelhak; Berishev, Igor

    2008-01-01

    Field-emission devices (cold cathodes) having low electron affinities can be fabricated through lattice-mismatched epitaxial growth of nitrides of elements from group III of the periodic table. Field emission of electrons from solid surfaces is typically utilized in vacuum microelectronic devices, including some display devices. The present field-emission devices and the method of fabricating them were developed to satisfy needs to reduce the cost of fabricating field emitters, make them compatible with established techniques for deposition of and on silicon, and enable monolithic integration of field emitters with silicon-based driving circuitry. In fabricating a device of this type, one deposits a nitride of one or more group-III elements on a substrate of (111) silicon or other suitable material. One example of a suitable deposition process is chemical vapor deposition in a reactor that contains plasma generated by use of electron cyclotron resonance. Under properly chosen growth conditions, the large mismatch between the crystal lattices of the substrate and the nitride causes strains to accumulate in the growing nitride film, such that the associated stresses cause the film to crack. The cracks lie in planes parallel to the direction of growth, so that the growing nitride film becomes divided into microscopic growing single-crystal columns. The outer ends of the fully-grown columns can serve as field-emission tips. By virtue of their chemical compositions and crystalline structures, the columns have low work functions and high electrical conductivities, both of which are desirable for field emission of electrons. From examination of transmission electron micrographs of a prototype device, the average column width was determined to be about 100 nm and the sharpness of the tips was determined to be characterized by a dimension somewhat less than 100 nm. The areal density of the columns was found to about 5 x 10(exp 9)/sq cm . about 4 to 5 orders of magnitude

  4. Photon diffusion in a homogeneous medium bounded externally or internally by an infinitely long circular cylindrical applicator. V. Steady-state fluorescence.

    Science.gov (United States)

    Piao, Daqing; Zhang, Anqi; Xu, Guan

    2013-04-01

    As Part V in our series, this paper examines steady-state fluorescence photon diffusion in a homogenous medium that contains a homogenous distribution of fluorophores, and is enclosed by a "concave" circular cylindrical applicator or is enclosing a "convex" circular cylindrical applicator, both geometries being infinite in the longitudinal dimension. The aim is to predict by analytics and examine with the finite-element method the changing characteristics of the fluorescence-wavelength photon-fluence rate and the ratio (sometimes called the Born ratio) of it versus the excitation-wavelength photon-fluence rate, with respect to the source-detector distance. The analysis is performed for a source and a detector located on the medium-applicator interface and aligned either azimuthally or longitudinally in both concave and convex geometries. When compared to its steady-state counterparts on a semi-infinite medium-applicator interface with the same line-of-sight source-detector distance, the fluorescence-wavelength photon-fluence rate reduces faster along the longitudinal direction and slower along the azimuthal direction in the concave geometry, and conversely in the convex geometry. However, the Born ratio increases slower in both azimuthal and longitudinal directions in the concave geometry and faster in both directions in the convex geometry, respectively, when compared to that in the semi-infinite geometry.

  5. Photon generator

    Science.gov (United States)

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  6. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2013-01-01

    Microwave photonics continues to see rapid growth. The integration of optical fiber and wireless networks has become a commercial reality and is becoming increasingly pervasive. Such hybrid technology will lead to many innovative applications, including backhaul solutions for mobile networks and ultrabroadband wireless networks that can provide users with very high bandwidth services. Microwave Photonics, Second Edition systematically introduces important technologies and applications in this emerging field. It also reviews recent advances in micro- and millimeter-wavelength and terahertz-freq

  7. Subnanosecond spectral diffusion measurement using photon correlation

    CERN Document Server

    Sallen, Gregory; Aichele, Thomas; André, Régis; Besombes, Lucien; Bougerol, Catherine; Richard, Maxime; Tatarenko, Serge; Kheng, Kuntheak; Poizat, Jean-Philippe; 10.1038/nphoton.2010.174

    2012-01-01

    Spectral diffusion is a result of random spectral jumps of a narrow line as a result of a fluctuating environment. It is an important issue in spectroscopy, because the observed spectral broadening prevents access to the intrinsic line properties. However, its characteristic parameters provide local information on the environment of a light emitter embedded in a solid matrix, or moving within a fluid, leading to numerous applications in physics and biology. We present a new experimental technique for measuring spectral diffusion based on photon correlations within a spectral line. Autocorrelation on half of the line and cross-correlation between the two halves give a quantitative value of the spectral diffusion time, with a resolution only limited by the correlation set-up. We have measured spectral diffusion of the photoluminescence of a single light emitter with a time resolution of 90 ps, exceeding by four orders of magnitude the best resolution reported to date.

  8. Low damage dry etch for III-nitride light emitters

    Science.gov (United States)

    Nedy, Joseph G.; Young, Nathan G.; Kelchner, Kathryn M.; Hu, Yanling; Farrell, Robert M.; Nakamura, Shuji; DenBaars, Steven P.; Weisbuch, Claude; Speck, James S.

    2015-08-01

    We have developed a dry etch process for the fabrication of lithographically defined features close to light emitting layers in the III-nitride material system. The dry etch was tested for its effect on the internal quantum efficiency of c-plane InGaN quantum wells using the photoluminescence of a test structure with two active regions. No change was observed in the internal quantum efficiency of the test active region when the etched surface was greater than 71 nm away. To demonstrate the application of the developed dry etch process, surface-etched air gaps were fabricated 275 nm away from the active region of an m-plane InGaN/GaN laser diode and served as the waveguide upper cladding. Electrically injected lasing was observed without the need for regrowth or recovery anneals. This dry etch opens up a new design tool that can be utilized in the next generation of GaN light emitters.

  9. Photonic lanterns

    Science.gov (United States)

    Leon-Saval, Sergio G.; Argyros, Alexander; Bland-Hawthorn, Joss

    2013-12-01

    Multimode optical fibers have been primarily (and almost solely) used as "light pipes" in short distance telecommunications and in remote and astronomical spectroscopy. The modal properties of the multimode waveguides are rarely exploited and mostly discussed in the context of guiding light. Until recently, most photonic applications in the applied sciences have arisen from developments in telecommunications. However, the photonic lantern is one of several devices that arose to solve problems in astrophotonics and space photonics. Interestingly, these devices are now being explored for use in telecommunications and are likely to find commercial use in the next few years, particularly in the development of compact spectrographs. Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail. Furthermore, we foreshadow future applications of this technology to the field of nanophotonics.

  10. Comparison of 1/f noise in complementary NPN and PNP polysilicon emitter bipolar transistors

    Science.gov (United States)

    Ul Hoque, Md M.; Celik-Butler, Zeynep; Trogolo, Joe; Weiser, Douglas; Green, Keith

    2005-05-01

    1/f noise was investigated in a complementary polysilicon emitter bipolar process. Noise measurements were carried out for variable base bias resistance (RS) to analyze how the contribution of each noise source changes as RS is varied. Two noise measurement setups were used to identify different noise sources in the transistors: noise from the base current (SIB), collector current (SIC), and internal resistances (SVr). The coherence for transistors measured in both measurement setups were close to unity, implying a single dominant noise source. SIB had the dominant contribution at lower bias currents. In this case, RS was relatively larger than the input resistance of the transistor. Higher current measurements with a smaller RS showed a dominant contribution from SVr. SIB was modeled as a combination of the minority carrier diffusion fluctuations in the monosilicon and polysilicon emitter, and tunneling fluctuations through the interfacial oxide. A combination of the number and diffusion fluctuations of the minority carriers in the base was used to model SIC. It was concluded that mainly originates from the fluctuations in the internal emitter resistance, which was ascribed to the tunneling fluctuations of the majority carriers through the interfacial oxide.

  11. Growth of optical-quality anthracene crystals doped with dibenzoterrylene for controlled single photon production

    Energy Technology Data Exchange (ETDEWEB)

    Major, Kyle D., E-mail: kyle.major11@imperial.ac.uk; Lien, Yu-Hung; Polisseni, Claudio; Grandi, Samuele; Kho, Kiang Wei; Clark, Alex S.; Hwang, J.; Hinds, E. A., E-mail: ed.hinds@imperial.ac.uk [Centre for Cold Matter, Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2015-08-15

    Dibenzoterrylene (DBT) molecules within a crystalline anthracene matrix show promise as quantum emitters for controlled, single photon production. We present the design and construction of a chamber in which we reproducibly grow doped anthracene crystals of optical quality that are several mm across and a few μm thick. We demonstrate control of the DBT concentration over the range 6–300 parts per trillion and show that these DBT molecules are stable single-photon emitters. We interpret our data with a simple model that provides some information on the vapour pressure of DBT.

  12. Increasing the photon collection rate from a single NV center with a silver mirror

    DEFF Research Database (Denmark)

    Israelsen, Niels Møller; Kumar, Shailesh; Tawfieq, Mahmoud

    2014-01-01

    In the pursuit of realizing quantum optical networks, a large variety of different approaches have been studied to achieve a single photon source on-demand. The common goal for these approaches is to harvest all the emission from a quantum emitter into a single spatial optical mode while...... maintaining a high signal-to-noise ratio. In this work, we use a single nitrogen vacancy center in diamond as a quantum emitter operating at ambient conditions and we demonstrate an increased photon count rate up to a factor of 1.76 by placing a silver mirror fabricated on the end facet of an optical fiber...

  13. Emitter space charge layer transit time in bipolar junction transistors

    Science.gov (United States)

    Rustagi, S. C.; Chattopadhyaya, S. K.

    1981-04-01

    The charge defined emitter space charge layer transit times of double diffused transistors have been calculated using a regional approach, and compared with the corresponding base transit times. The results obtained for emitter space-charge layer transit times have been discussed with reference to the capacitance analysis of Morgan and Smit (1960) for graded p-n junctions.

  14. TOMOGRAPHIC MEASUREMENT OF LONGITUDINAL EMITTANCE GROWTH DUE TO STRIPPING FOILS.

    Energy Technology Data Exchange (ETDEWEB)

    MONTAG, C.; AHRENS, L.; THIEBERGER, P.

    2005-05-16

    During beam acceleration in the Brookhaven accelerator complex, heavy ions are stripped of their electrons in several steps. Depending on the properties of the stripping foils, this process results in an increased energy spread and longitudinal emittance growth. A tomographic phase space reconstruction technique has been applied to measure the associated emittance growth for different stripping foil materials.

  15. Bunch transverse emittance increase in electron storage rings

    Institute of Scientific and Technical Information of China (English)

    GAO Jie

    2009-01-01

    In this paper a theoretical framework to estimate the bunch transverse emittance growing in electron storage rings due to short range transverse wakefield of the machine is established. New equilibrium emittance equations are derived and applied to explain the experimentally obtained results in ATF damping ring. This equation will be useful for linear collider damping ring design.

  16. Electronic Warfare:Issues and Challenges for Emitter Classification

    Directory of Open Access Journals (Sweden)

    Manish Gupta

    2011-04-01

    Full Text Available Electronic warfare (EW is an important capability that provides advantage to defence forces over their adversaries. Defence forces gather tactical intelligence through EW sensors, which provide the means to counter hostile actions of enemy forces. Functions of an EW system is threat detection and the area surveillance so as to determine the identity of surrounding emitters. Emitter classification system identifies possible threats by analysing intercepted signals. Problem of identifying emitters based on its intercepted signal characteristics is a challenging problem in electronic warfare studies. Major issues and challenges for emitter classification such as drifting of emitter parameters due to aging, operational characteristic of an emitter, i.e., same emitter can operate on multiple bands and multiple pulse repetition frequencies (PRFs are highlighted. A novel approach based on some well-known statistical methods, e.g., regression analysis, hypothesis testing, and discriminent analysis is proposed. The effectiveness of the proposed approach has been tested over ELINT (Electronic Intelligence data and illustrated using simulation data. The proposed approach can play a solution for wide variety of problems in emitter classification in electronic warfare studies.Defence Science Journal, 2011, 61(3, pp.228-234, DOI:http://dx.doi.org/10.14429/dsj.61.529

  17. Thermionic scanner pinpoints work function of emitter surfaces

    Science.gov (United States)

    Rasor, N. S.

    1966-01-01

    In the electron tube testing, a thermionic scanner makes accurate spatial resolution measurements of the metallic surface work functions of emitters. The scanner determines the emitter function and its local departures from the mean value on a point-by-point basis for display on an oscilloscope.

  18. Studies of phosphorus Gaussian profile emitter silicon solar cells

    Directory of Open Access Journals (Sweden)

    N. Stem

    2001-01-01

    Full Text Available Considering recent modifications on n-type highly doped silicon parameters, an emitter optimization was made based on one-dimensional models with analytical solutions. In order to get good accuracy, a fifth order approximation has been considered. Two kinds of emitters, homogeneous and non-homogeneous, with phosphorus Gaussian profile emitter solar cells were optimized. According to our results: homogeneous emitter solar cells show their maximum efficiencies (h @ 21.60-21.74%with doping levelsnus = 1x10(19 - 5x10(18 (cm-3 and (1.2-2.0 mum emitter thickness range. Non-homogeneous emitter solar cells provide a slightly higher efficiency (eta = 21.82-21.92%, with Ns = 1x10(20 (cm-3 with 2.0 mum thickness under metal-contacted surface and Ns = 1x10(19 - 5x10(18 (cm-3 with (1.2-2.0 mum thickness range, (sheet resistance range 90-100 W/ under passivated surface. Although non-homogeneous emitter solar cells have a higher efficiency than homogeneous emitter ones, the required technology is more complex and their overall interest for practical applications is questionable.

  19. Modelling of photonic crystal fibres

    DEFF Research Database (Denmark)

    Knudsen, Erik

    2003-01-01

    In the presenta ph.d. work a theoretical study of aspects of modelling photonic crystal fibres was carried out. Photonic crystal fibres form a class of optical waveguides where guidance is no longer provided by a difference in refractive index between core and cladding. Instead, guidance...... is provided by an arrangement of air-holes running along the length of the fibre. Depending on the geometry of the fibre, the guiding mechanism may be either arising from the formation of a photonic bandgap in the cladding structure (photonic bandgap fibre), or by an effect resembling total internal...... modes in contiguous fibre segments curved at different radii. Overall microbend loss is expressed as a statistical mean of mismatch losses. Extending a well proven, established formula for macrobending losses in stop index fibres, we provide an estimate of macrobend losses in an air-guiding photonic...

  20. Exploring Dephasing of a Solid-State Quantum Emitter via Time- and Temperature-Dependent Hong-Ou-Mandel Experiments

    Science.gov (United States)

    Thoma, A.; Schnauber, P.; Gschrey, M.; Seifried, M.; Wolters, J.; Schulze, J.-H.; Strittmatter, A.; Rodt, S.; Carmele, A.; Knorr, A.; Heindel, T.; Reitzenstein, S.

    2016-01-01

    We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature-dependent two-photon interference (TPI) experiments. An increase in temporal separation between consecutive photon emission events reveals a decrease in TPI visibility on a nanosecond time scale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from (96 ±4 )% at 10 K to a vanishing visibility at 40 K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter on a nanosecond time scale.

  1. Power flow from a dipole emitter near an optical antenna.

    Science.gov (United States)

    Huang, Kevin C Y; Jun, Young Chul; Seo, Min-Kyo; Brongersma, Mark L

    2011-09-26

    Current methods to calculate the emission enhancement of a quantum emitter coupled to an optical antenna of arbitrary geometry rely on analyzing the total Poynting vector power flow out of the emitter or the dyadic Green functions from full-field numerical simulations. Unfortunately, these methods do not provide information regarding the nature of the dominant energy decay pathways. We present a new approach that allows for a rigorous separation, quantification, and visualization of the emitter output power flow captured by an antenna and the subsequent reradiation power flow to the far field. Such analysis reveals unprecedented details of the emitter/antenna coupling mechanisms and thus opens up new design strategies for strongly interacting emitter/antenna systems used in sensing, active plasmonics and metamaterials, and quantum optics.

  2. Superradiance of a subwavelength array of independent classical nonlinear emitters

    CERN Document Server

    Nefedkin, N E; Zyablovsky, A A; Pukhov, A A; Vinogradov, A P; Lisyansky, A A

    2015-01-01

    We suggest a mechanism for the emergence of a superradiance burst in a subwavelength array of nonlinear classical emitters. We assume that the emitters interact via their common field of radiative response and that they may have an arbitrary distribution of initially phases. We show that only if this distribution is not uniform, a non-zero field of radiative response arises leading to a superradiance burst. Although this field cannot synchronize the emitters, it forces fast oscillations of a classical nonlinear emitter to have long-period envelopes. Constructive interference in the envelopes creates a large dipole moment of the array which results in a superradiance pulse. The intensity of the superradiance is proportional to the squared number of the emitters, which envelopes participate in the fluctuation.

  3. Evaluations of carbon nanotube field emitters for electron microscopy

    Science.gov (United States)

    Nakahara, Hitoshi; Kusano, Yoshikazu; Kono, Takumi; Saito, Yahachi

    2009-11-01

    Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I- V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6×109 A/m 2 sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy.

  4. Evaluations of carbon nanotube field emitters for electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Hitoshi, E-mail: nakahara@nagoya-u.jp [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kusano, Yoshikazu; Kono, Takumi; Saito, Yahachi [Department of Quantum Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2009-11-30

    Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I-V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6x10{sup 9} A/m{sup 2} sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy.

  5. Photonic crystal optical memory

    Science.gov (United States)

    Lima, A. Wirth; Sombra, A. S. B.

    2011-06-01

    After several decades pushing the technology and the development of the world, the electronics is giving space for technologies that use light. We propose and analyze an optical memory embedded in a nonlinear photonic crystal (PhC), whose system of writing and reading data is controlled by an external command signal. This optical memory is based on optical directional couplers connected to a shared optical ring. Such a device can work over the C-Band of ITU (International Telecommunication Union).

  6. Monte Carlo calculations of positron emitter yields in proton radiotherapy.

    Science.gov (United States)

    Seravalli, E; Robert, C; Bauer, J; Stichelbaut, F; Kurz, C; Smeets, J; Van Ngoc Ty, C; Schaart, D R; Buvat, I; Parodi, K; Verhaegen, F

    2012-03-21

    Positron emission tomography (PET) is a promising tool for monitoring the three-dimensional dose distribution in charged particle radiotherapy. PET imaging during or shortly after proton treatment is based on the detection of annihilation photons following the ß(+)-decay of radionuclides resulting from nuclear reactions in the irradiated tissue. Therapy monitoring is achieved by comparing the measured spatial distribution of irradiation-induced ß(+)-activity with the predicted distribution based on the treatment plan. The accuracy of the calculated distribution depends on the correctness of the computational models, implemented in the employed Monte Carlo (MC) codes that describe the interactions of the charged particle beam with matter and the production of radionuclides and secondary particles. However, no well-established theoretical models exist for predicting the nuclear interactions and so phenomenological models are typically used based on parameters derived from experimental data. Unfortunately, the experimental data presently available are insufficient to validate such phenomenological hadronic interaction models. Hence, a comparison among the models used by the different MC packages is desirable. In this work, starting from a common geometry, we compare the performances of MCNPX, GATE and PHITS MC codes in predicting the amount and spatial distribution of proton-induced activity, at therapeutic energies, to the already experimentally validated PET modelling based on the FLUKA MC code. In particular, we show how the amount of ß(+)-emitters produced in tissue-like media depends on the physics model and cross-sectional data used to describe the proton nuclear interactions, thus calling for future experimental campaigns aiming at supporting improvements of MC modelling for clinical application of PET monitoring.

  7. Nano-optomechanical measurement in the photon counting regime

    CERN Document Server

    de Lépinay, Laure Mercier; Rohr, Sven; Gloppe, Arnaud; Kuhn, Aurélien; Verlot, Pierre; Dupont-Ferrier, Eva; Besga, Benjamin; Arcizet, Olivier

    2015-01-01

    Optically measuring in the photon counting regime is a recurrent challenge in modern physics and a guarantee to develop weakly invasive probes. Here we investigate this idea on a hybrid nano-optomechanical system composed of a nanowire hybridized to a single Nitrogen-Vacancy (NV) defect. The vibrations of the nanoresonator grant a spatial degree of freedom to the quantum emitter and the photon emission event can now vary in space and time. We investigate how the nanomotion is encoded on the detected photon statistics and explore their spatio-temporal correlation properties. This allows a quantitative measurement of the vibrations of the nanomechanical oscillator at unprecedentedly low light intensities in the photon counting regime when less than one photon is detected per oscillation period, where standard detectors are dark-noise-limited. These results have implications for probing weakly interacting nanoresonators, for low temperature experiments and for investigating single moving markers.

  8. Suppressing Spectral Diffusion of the Emitted Photons with Optical Pulses

    CERN Document Server

    Fotso, H F; Awschalom, D D; Dobrovitski, V V

    2016-01-01

    In many quantum architectures the solid-state qubits, such as quantum dots or color centers, are interfaced via emitted photons. However, the frequency of photons emitted by solid-state systems exhibits slow uncontrollable fluctuations over time (spectral diffusion), creating a serious problem for implementation of the photon-mediated protocols. Here we show that a sequence of optical pulses applied to the solid-state emitter can stabilize the emission line at the desired frequency. We demonstrate efficiency, robustness, and feasibility of the method analytically and numerically. Taking nitrogen-vacancy (NV) center in diamond as an example, we show that only several pulses, with the width of 1 ns, separated by few ns (which is not difficult to achieve) can suppress spectral diffusion. Our method provides a simple and robust way to greatly improve the efficiency of photon-mediated entanglement and/or coupling to photonic cavities for solid-state qubits.

  9. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  10. Single-Photon Switching and Entanglement of Solid-State Qubits in an Integrated Nanophotonic System

    CERN Document Server

    Sipahigil, Alp; Sukachev, Denis D; Burek, Michael J; Borregaard, Johannes; Bhaskar, Mihir K; Nguyen, Christian T; Pacheco, Jose L; Atikian, Haig A; Meuwly, Charles; Camacho, Ryan M; Jelezko, Fedor; Bielejec, Edward; Park, Hongkun; Lončar, Marko; Lukin, Mikhail D

    2016-01-01

    Efficient interfaces between photons and quantum emitters form the basis for quantum networks and enable nonlinear optical devices operating at the single-photon level. We demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to nanoscale diamond devices. By placing SiV centers inside diamond photonic crystal cavities, we realize a quantum-optical switch controlled by a single color center. We control the switch using SiV metastable orbital states and verify optical switching at the single-photon level by using photon correlation measurements. We use Raman transitions to realize a single-photon source with a tunable frequency and bandwidth in a diamond waveguide. Finally, we create entanglement between two SiV centers by detecting indistinguishable Raman photons emitted into a single waveguide. Entanglement is verified using a novel superradiant feature observed in photon correlation measurements, paving the way for the realization of quantu...

  11. Fully integrated quantum photonic circuit with an electrically driven light source

    Science.gov (United States)

    Khasminskaya, Svetlana; Pyatkov, Felix; Słowik, Karolina; Ferrari, Simone; Kahl, Oliver; Kovalyuk, Vadim; Rath, Patrik; Vetter, Andreas; Hennrich, Frank; Kappes, Manfred M.; Gol'Tsman, G.; Korneev, A.; Rockstuhl, Carsten; Krupke, Ralph; Pernice, Wolfram H. P.

    2016-11-01

    Photonic quantum technologies allow quantum phenomena to be exploited in applications such as quantum cryptography, quantum simulation and quantum computation. A key requirement for practical devices is the scalable integration of single-photon sources, detectors and linear optical elements on a common platform. Nanophotonic circuits enable the realization of complex linear optical systems, while non-classical light can be measured with waveguide-integrated detectors. However, reproducible single-photon sources with high brightness and compatibility with photonic devices remain elusive for fully integrated systems. Here, we report the observation of antibunching in the light emitted from an electrically driven carbon nanotube embedded within a photonic quantum circuit. Non-classical light generated on chip is recorded under cryogenic conditions with waveguide-integrated superconducting single-photon detectors, without requiring optical filtering. Because exclusively scalable fabrication and deposition methods are used, our results establish carbon nanotubes as promising nanoscale single-photon emitters for hybrid quantum photonic devices.

  12. Recovering the triple coincidence of non-pure positron emitters in preclinical PET

    Science.gov (United States)

    Lin, Hsin-Hon; Chuang, Keh-Shih; Chen, Szu-Yu; Jan, Meei-Ling

    2016-03-01

    Non-pure positron emitters, with their long half-lives, allow for the tracing of slow biochemical processes which cannot be adequately examined by the commonly used short-lived positron emitters. Most of these isotopes emit high-energy cascade gamma rays in addition to positron decay that can be detected and create a triple coincidence with annihilation photons. Triple coincidence is discarded in most scanners, however, the majority of the triple coincidence contains true photon pairs that can be recovered. In this study, we propose a strategy for recovering triple coincidence events to raise the sensitivity of PET imaging for non-pure positron emitters. To identify the true line of response (LOR) from a triple coincidence, a framework utilizing geometrical, energy and temporal information is proposed. The geometrical criterion is based on the assumption that the LOR with the largest radial offset among the three sub pairs of triple coincidences is least likely to be a true LOR. Then, a confidence time window is used to test the valid LOR among those within triple coincidence. Finally, a likelihood ratio discriminant rule based on the energy probability density distribution of cascade and annihilation gammas is established to identify the true LOR. An Inveon preclinical PET scanner was modeled with GATE (GEANT4 application for tomographic emission) Monte Carlo software. We evaluated the performance of the proposed method in terms of identification fraction, noise equivalent count rates (NECR), and image quality on various phantoms. With the inclusion of triple coincidence events using the proposed method, the NECR was found to increase from 11% to 26% and 19% to 29% for I-124 and Br-76, respectively, when 7.4-185 MBq of activity was used. Compared to the reconstructed images using double coincidence, this technique increased the SNR by 5.1-7.3% for I-124 and 9.3-10.3% for Br-76 within the activity range of 9.25-74 MBq, without compromising the spatial resolution or

  13. Photon and π0 pairs production in proton-nucleus and deuteron-nucleus interactions. Results of experiments on internal beams of the Nuclotron

    Directory of Open Access Journals (Sweden)

    Abraamyan Khachik

    2017-01-01

    Full Text Available The results of experiments on photon and π0 pairs production in interactions of 5.5 GeV/c protons, 2.75 and 3.83 GeV/c per nucleon deuterons with carbon and copper nuclei are presented. As previously reported (see. [1] and references therein, along with π0 and η mesons, a resonance structure in the invariant mass spectrum of two photons at Mγγ = 360 ± 7 ± 9 MeV is observed in the reaction dC → γ + γ + X at momentum 2.75 GeV/c per nucleon. Here are some results of testing the signal and results of statistical analysis of the experimental data which allow to explain the lack of appearance of the signal in other experiments [2, 3] and make predictions for possible appearances of the signal in upcoming experiments.

  14. On-chip single photon filtering and multiplexing in hybrid quantum photonic circuits.

    Science.gov (United States)

    Elshaari, Ali W; Zadeh, Iman Esmaeil; Fognini, Andreas; Reimer, Michael E; Dalacu, Dan; Poole, Philip J; Zwiller, Val; Jöns, Klaus D

    2017-08-30

    Quantum light plays a pivotal role in modern science and future photonic applications. Since the advent of integrated quantum nanophotonics different material platforms based on III-V nanostructures-, colour centers-, and nonlinear waveguides as on-chip light sources have been investigated. Each platform has unique advantages and limitations; however, all implementations face major challenges with filtering of individual quantum states, scalable integration, deterministic multiplexing of selected quantum emitters, and on-chip excitation suppression. Here we overcome all of these challenges with a hybrid and scalable approach, where single III-V quantum emitters are positioned and deterministically integrated in a complementary metal-oxide-semiconductor-compatible photonic circuit. We demonstrate reconfigurable on-chip single-photon filtering and wavelength division multiplexing with a foot print one million times smaller than similar table-top approaches, while offering excitation suppression of more than 95 dB and efficient routing of single photons over a bandwidth of 40 nm. Our work marks an important step to harvest quantum optical technologies' full potential.Combining different integration platforms on the same chip is currently one of the main challenges for quantum technologies. Here, Elshaari et al. show III-V Quantum Dots embedded in nanowires operating in a CMOS compatible circuit, with controlled on-chip filtering and tunable routing.

  15. Mesoscopic quantum emitters coupled to plasmonic nanostructures

    DEFF Research Database (Denmark)

    Andersen, Mads Lykke

    This thesis reports research on quantum dots coupled to dielectric and plasmonic nano-structures by way of nano-structure fabrication, optical measurements, and theoretical modeling. To study light-matter interaction, plasmonic gap waveguides with nanometer dimensions as well as samples for studies...... of quantum dots in proximity to semiconductor/air and semiconductor/metal interfaces, were fabricated. We measured the decay dynamics of quantum dots near plasmonic gap waveguides and observed modied decay rates. The obtainable modications with the fabricated structures are calculated to be too small...... for the spontaneous emission of mesoscopic quantum emitters is developed. The light-matter interaction is in this model modied beyond the dipole expectancy and found to both suppress and enhance the coupling to plasmonic modes in excellent agreement with our measurements. We demonstrate that this mesoscopic effect...

  16. Physical electrostatics of small field emitter arrays/clusters

    Science.gov (United States)

    Forbes, Richard G.

    2016-08-01

    This paper aims to improve qualitative understanding of electrostatic influences on apex field enhancement factors (AFEFs) for small field emitter arrays/clusters. Using the "floating sphere at emitter-plate potential" (FSEPP) model, it re-examines the electrostatics and mathematics of three simple systems of identical post-like emitters. For the isolated emitter, various approaches are noted. An adequate approximation is to consider only the effects of sphere charges and (for significantly separated emitters) image charges. For the 2-emitter system, formulas are found for charge-transfer ("charge-blunting") effects and neighbor-field effects, for widely spaced and for "sufficiently closely spaced" emitters. Mutual charge-blunting is always the dominant effect, with a related (negative) fractional AFEF-change δtwo. For sufficiently small emitter spacing c, |δtwo| varies approximately as 1/c; for large spacing, |δtwo| decreases as 1/c3. In a 3-emitter equispaced linear array, differential charge-blunting and differential neighbor-field effects occur, but differential charge-blunting effects are dominant, and cause the "exposed" outer emitters to have higher AFEF (γ0) than the central emitter (γ1). Formulas are found for the exposure ratio Ξ = γ0/γ1, for large and for sufficiently small separations. The FSEPP model for an isolated emitter has accuracy around 30%. Line-charge models (LCMs) are an alternative, but an apparent difficulty with recent LCM implementations is identified. Better descriptions of array electrostatics may involve developing good fitting equations for AFEFs derived from accurate numerical solution of Laplace's equation, perhaps with equation form(s) guided qualitatively by FSEPP-model results. In existing fitting formulas, the AFEF-reduction decreases exponentially as c increases, which is different from the FSEPP-model formulas. This discrepancy needs to be investigated, using systematic Laplace-based simulations and appropriate results

  17. Quantum photonics

    CERN Document Server

    Pearsall, Thomas P

    2017-01-01

    This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schrödinger’s equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non­locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch’s theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconducto...

  18. Study of the time and space distribution of $\\beta^+$ emitters from $80\\ \\mega\\electronvolt/$u carbon ion beam irradiation on PMMA

    CERN Document Server

    Agodi, C; Cirrone, G A P; Collamati, F; Cuttone, G; De Lucia, E; De Napoli, M; Di Domenico, A; Faccini, R; Ferroni, F; Fiore, S; Gauzzi, P; Iarocci, E; Marafini, M; Mattei, I; Paoloni, A; Patera, V; Piersanti, L; Romano, F; Sarti, A; Sciubba, A; Voena, C

    2012-01-01

    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear $511\\ \\kilo\\electronvolt$ photons produced by positrons annihilation from $\\beta^+$ emitters created by the beam. This paper reports rate measurements of the $511\\ \\kilo\\electronvolt$ photons emitted after the interactions of a $80\\ \\mega\\electronvolt / u$ fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a Poly-methyl methacrylate target. The time evolution of the $\\beta^+$ rate was parametrized and the dominance of $^{11}C$ emitters over the other species ($^{13}N$, $^{15}O$, $^{14}O$) was observed, measuring the fraction of carbon ions activating $\\beta^+$ emitters $A_0=(10.3\\pm0.7)\\cdot10^{-3}$. The average depth in the PMMA of the positron annihilation from $\\beta^+$ emitters was also meas...

  19. Study of the time and space distribution of {beta}{sup +} emitters from 80MeV/u carbon ion beam irradiation on PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Agodi, C. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Bellini, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Cirrone, G.A.P. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Collamati, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Cuttone, G. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); De Lucia, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); De Napoli, M. [Laboratori Nazionali del Sud dell' INFN, Catania (Italy); Di Domenico, A.; Faccini, R.; Ferroni, F. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Fiore, S. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); Gauzzi, P. [Dipartimento di Fisica, Sapienza Universita di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Iarocci, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dipartimento di Scienze di Base e Applicate per l' Ingegneria, Sapienza Universita di Roma, Roma (Italy); Marafini, M., E-mail: michela.marafini@roma1.infn.it [Museo Storico della Fisica e Centro Studi e Ricerche ' E. Fermi' , Roma (Italy); Mattei, I. [Dipartimento di Fisica, Roma Tre Universita di Roma, Roma (Italy); Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Paoloni, A. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); and others

    2012-07-15

    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear 511keV photons produced by positrons annihilation from {beta}{sup +} emitters created by the beam. This paper reports rate measurements of the 511keV photons emitted after the interactions of a 80MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a poly-methyl methacrylate target. The time evolution of the {beta}{sup +} rate was parametrized and the dominance of {sup 11}C emitters over the other species ({sup 13}N, {sup 15}O, {sup 14}O) was observed, measuring the fraction of carbon ions activating {beta}{sup +} emitters to be (10.3{+-}0.7) Multiplication-Sign 10{sup -3}. The average depth in the PMMA of the positron annihilation from {beta}{sup +} emitters was also measured, D{sub {beta}{sup +}}=5.3{+-}1.1mm, to be compared to the expected Bragg peak depth D{sub Bragg}=11.0{+-}0.5mm obtained from simulations.

  20. Manipulating the Electronic Excited State Energies of Pyrimidine-Based Thermally Activated Delayed Fluorescence Emitters To Realize Efficient Deep-Blue Emission.

    Science.gov (United States)

    Komatsu, Ryutaro; Ohsawa, Tatsuya; Sasabe, Hisahiro; Nakao, Kohei; Hayasaka, Yuya; Kido, Junji

    2017-02-08

    The development of efficient and robust deep-blue emitters is one of the key issues in organic light-emitting devices (OLEDs) for environmentally friendly, large-area displays or general lighting. As a promising technology that realizes 100% conversion from electrons to photons, thermally activated delayed fluorescence (TADF) emitters have attracted considerable attention. However, only a handful of examples of deep-blue TADF emitters have been reported to date, and the emitters generally show large efficiency roll-off at practical luminance over several hundreds to thousands of cd m(-2), most likely because of the long delayed fluorescent lifetime (τd). To overcome this problem, we molecularly manipulated the electronic excited state energies of pyrimidine-based TADF emitters to realize deep-blue emission and reduced τd. We then systematically investigated the relationships among the chemical structure, properties, and device performances. The resultant novel pyrimidine emitters, called Ac-XMHPMs (X = 1, 2, and 3), contain different numbers of bulky methyl substituents at acceptor moieties, increasing the excited singlet (ES) and triplet state (ET) energies. Among them, Ac-3MHPM, with a high ET of 2.95 eV, exhibited a high external quantum efficiency (ηext,max) of 18% and an ηext of 10% at 100 cd m(-2) with Commission Internationale de l'Eclairage chromaticity coordinates of (0.16, 0.15). These efficiencies are among the highest values to date for deep-blue TADF OLEDs. Our molecular design strategy provides fundamental guidance to design novel deep-blue TADF emitters.

  1. Photonic crystals

    CERN Document Server

    Busch, Kurt; Wehrspohn, Ralf B; Föll, Helmut

    2006-01-01

    The majority of the contributions in this topically edited book stems from the priority program SPP 1113 ""Photonische Kristalle"" run by the Deutsche Forschungsgemeinschaft (DFG), resulting in a survey of the current state of photonic crystal research in Germany. The first part of the book describes methods for the theoretical analysis of their optical properties as well as the results. The main part is dedicated to the fabrication, characterization and modeling of two- and three-dimensional photonic crystals, while the final section presents a wide spectrum of applications: gas sensors, micr

  2. Green photonics

    Science.gov (United States)

    Quan, Frederic

    2012-02-01

    Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas.

  3. Photonic crystals principles and applications

    CERN Document Server

    Gong, Qihuang

    2013-01-01

    IntroductionPrimary Properties of Photonic CrystalsFabrication of Photonic CrystalsPhotonic Crystal All-Optical SwitchingTunable Photonic Crystal FilterPhotonic Crystal LaserPhotonic Crystal Logic DevicesPhotonic Crystal Sensors

  4. 滴灌条件下水的硬度对滴头堵塞的影响%Effect of water hardness on emitter clogging of drip irrigation

    Institute of Scientific and Technical Information of China (English)

    刘燕芳; 吴普特; 朱德兰; 张林; 陈俊英

    2015-01-01

    Hard water is used for drip irrigation in some areas of China due to precipitation and groundwater resource limitation. But it is proved that drip irrigation emitters can be clogged when using hard water for irrigation. In order to explore the influence of temporary hard water on emitter clogging and clogging mechanism in drip irrigation system, a laboratory experiment was conducted to investigate the variations of the emitter's average relative flow rate and the distribution of clogged emitters along the drip line and the clogging materials in the clogged emitters. The experiment started in April 2014 at the Irrigation Hydraulics Laboratory of Northwest A&F University. Two kinds of emitters (internal cylindrical type and internal inserting type) were used and water hardness was set at 3 levels (0, 250 and 500 mg/L) in this experiment. Corresponding to 3 kinds of irrigation water, 3 independent and identical drip irrigation systems with cyclic water were built. Each system has 4 drip lines (2 drip tubes with internal cylindrical emitter and 2 drip tapes with internal inserting emitter). And there were 18 emitters on each drip line. The total duration of irrigation was 35 d, with a daily application of 4 h (from 8:00 to 12:00) under working pressure of 100 kPa. Flow rates of all the emitters were measured once every 7 days using the weighting method. The clogging in the labyrinth passage was analyzed by the field emission scanning electron microscope (FESEM) after all irrigation events. The results indicated that the water hardness had a very significant influence on the level of emitter clogging. For the 2 kinds of emitters, the average relative flow rates were maintained at more than 95% of the original flow rate during whole experiment with 0 hardness water, and none of emitters was clogged; the average relative flow rates were 51.1% and 59.4% respectively for internal cylindrical emitter and internal inserting emitter with 250 mg/L hardness water, and the

  5. Photonic Bandgaps in Photonic Molecules

    Science.gov (United States)

    Smith, David D.; Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    This talk will focus on photonic bandgaps that arise due to nearly free photon and tight-binding effects in coupled microparticle and ring-resonator systems. The Mie formulation for homogeneous spheres is generalized to handle core/shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multi-layered structures to be treated as photonic bandgap (PBG) materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands arising from nearly free photon effects are easily observed in the backscattering, asymmetry parameter, and albedo for periodic quarter-wave concentric layers, though are not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, enhancing the ratio of backscattering to forward scattering inside the bandgap, in direct analogy with planar quarter-wave multilayers. PBGs arising from tight-binding may also be observed when the layers (or rings) are designed such that the coupling between them is weak. We demonstrate that for a structure consisting of N coupled micro-resonators, the morphology dependent resonances split into N higher-Q modes, in direct analogy with other types of oscillators, and that this splitting ultimately results in PBGs which can lead to enhanced nonlinear optical effects.

  6. Courant-Snyder invariant density screening method for emittance analysis

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-Lei; TANG Jing-Yu; JING Han-Tao

    2011-01-01

    Emittance is an important characteristic of describing charged particle beams.In hadron accelerators,we often meet irregular beam distributions that are not appropriately described by a single rms emittance or 95% emittance or total emittance.In this paper,it is pointed out that in many cases a beam halo should be described with very different Courant-Snyder parameters from the ones used for the beam core.A new method - the Courant-Snyder invariant density screening method - is introduced for analyzing emittance data clearly and accurately.The method treats the emittance data from both measurements and numerical simulations.The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter,and then uses the density distribution to calculate the beam parameters such as the Courant-Snyder parameters and emittance for different beam boundary definitions.The method has been used in the calculations for.beams from different sources,and shows its advantages over other methods.An application code based on the method including the graphic interface has also been designed.

  7. Quantum Electrodynamics in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Nielsen, Henri Thyrrestrup

    In this thesis we have performed quantum electrodynamics (QED) experiments in photonic crystal (PhC) waveguides and cavity QED in the Anderson localized regime in disordered PhC waveguides. Decay rate measurements of quantum dots embedded in PhC waveguides has been used to map out the variations...... probability. The Q-factor distributions of Anderson localized modes have been measured in PhC waveguides with articial induced disorder with embedded emitters. The largest Q-factors are found in the sample with the smallest amount of disorder. From a comparison with the waveguide model the localization length...

  8. Time reversal constraint limits unidirectional photon emission in slow-light photonic crystals

    CERN Document Server

    Lang, Ben; Oulton, Ruth

    2016-01-01

    Photonic crystal waveguides are known to support C-points - point-like polarisation singularities with local chirality. Such points can couple with dipole-like emitters to produce highly directional emission, from which spin-photon entanglers can be built. Much is made of the promise of using slow-light modes to enhance this light-matter coupling. Here we explore the transition from travelling to standing waves for two different photonic crystal waveguide designs. We find that time-reversal symmetry and the reciprocal nature of light places constraints on using C-points in the slow-light regime. We observe two distinctly different mechanisms through which this condition is satisfied in the two waveguides. In the waveguide designs we consider, a modest group-velocity of $v_g \\approx c/10$ is found to be the optimum for slow-light coupling to the C-points.

  9. Photon differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Revall Frisvad, Jeppe; Erleben, Kenny;

    2007-01-01

    illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation...

  10. Enhanced and directional single photon emission in hyperbolic metamaterials

    CERN Document Server

    Newman, Ward D; Jacob, Zubin

    2013-01-01

    We propose an approach to enhance and direct the spontaneous emission from isolated emitters embedded inside hyperbolic metamaterials into single photon beams. The approach rests on collective plasmonic Bloch modes of hyperbolic metamaterials which propagate in highly directional beams called quantum resonance cones. We propose a pumping scheme using the transparency window of the hyperbolic metamaterial that occurs near the topological transition. Finally, we address the challenge of outcoupling these broadband resonance cones into vacuum using a dielectric bullseye grating. We give a detailed analysis of quenching and design the metamaterial to have a huge Purcell factor in a broad bandwidth inspite of the losses in the metal. Our work should help motivate experiments in the development of single photon sources for broadband emitters such as nitrogen vacancy centers in diamond.

  11. Emittance Adapter for a Diffraction Limited Synchrotron Radiation Source

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alexander Wu; /SLAC; Raimondi, Pantaleo; /Frascati

    2012-03-01

    We investigate the possibility of reaching very small horizontal and vertical emittances inside an undulator in a storage ring, by means of a local exchange of the apparent horizontal and vertical emittances, performed with a combination of skew quadrupoles and one solenoid in a dedicated insertion line in the storage ring. The insertion leaves the ring parameters and its optical properties unaffected. This scheme could greatly relax the emittance requirements for a diffraction limited synchrotron light source. The lattice derivation and design is described.

  12. Design of a minimum emittance nBA lattice

    Science.gov (United States)

    Lee, S. Y.

    1998-04-01

    An attempt to design a minimum emittance n-bend achromat (nBA) lattice has been made. One distinct feature is that dipoles with two different lengths were used. As a multiple bend achromat, five bend achromat lattices with six superperiod were designed. The obtained emittace is three times larger than the theoretical minimum. Tunes were chosen to avoid third order resonances. In order to correct first and second order chromaticities, eight family sextupoles were placed. The obtained emittance of five bend achromat lattices is almost equal to the minimum emittance of five bend achromat lattice consisting of dipoles with equal length.

  13. Emittance Compensation in a Flat Beam RF Photoinjector

    Science.gov (United States)

    Rosenzweig, J. B.; Anderson, S.; Colby, E.; Serafini, L.

    1997-05-01

    The beam dynamics of a flat beam rf photoinjector, which is intended to produce asymmetric emittances for linear collider applications, are analyzed, by both analytical and computational methods. The analytical model is a generalization of the recently developed theory of emittance compensation in round beams(L.Serafini, and J.B. Rosenzweig, submitted to Physical Review E.), in which a new mode of laminar flow beam dynamics, the invariant envelope, is found to give the ideal conditions for emittance minimization. Three-dimensional rf and beam dynamics simulations are used to iluminate the analytical results. abstract.

  14. New Low Emittance Lattice for the Super-B Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boscolo, M.; Raimondi, P.; Tomassini, S.; Zobov, M.; /Frascati; Seeman, J.; Sullivan, M.; Wienands, U.; Wittmer, W.; /SLAC; Bettoni, S.; /CERN; Paoloni, E.; /Pisa U. /INFN, Pisa; Bogomyagkov, A.; Koop, I.; Levichev, E.; Nikitin, S.; Piminov, P.; Shatilov, D.; /Novosibirsk, IYF

    2011-10-21

    New low emittance lattices have been designed for the asymmetric SuperB accelerator, aiming at a luminosity of 10{sup 36} cm{sup -2} s{sup -1}. Main optics features are two alternating arc cells with different horizontal phase advance, decreasing beam emittance and allowing at the same time for easy chromaticity correction in the arcs. Emittance can be further reduced by a factor of two for luminosity upgrade. Spin rotation schemes for the e{sup -} beam have been studied to provide longitudinal polarization at the IP, and implementation into the lattice is in progress.

  15. Observation of picometer vertical emittance with a vertical undulator.

    Science.gov (United States)

    Wootton, K P; Boland, M J; Dowd, R; Tan, Y-R E; Cowie, B C C; Papaphilippou, Y; Taylor, G N; Rassool, R P

    2012-11-09

    Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.

  16. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 ± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  17. Incoherent photon conversion in selectively infiltrated hollow-core photonic crystal fibers for single photon generation in the near infrared.

    Science.gov (United States)

    Jiang, Ping; Schroeder, Tim; Bath, Michael; Lesnyak, Vladimir; Gaponik, Nikolai; Eychmüller, Alexander; Benson, Oliver

    2012-05-07

    At present, there exist a number of on-demand single photon sources with high emission rates and stability even at room temperature. However, their emission wavelength is restricted to specific transitions in single quantum emitters. Single photon generation in the near infrared, possibly within the telecom band, though most urgently needed, is particularly crucial. In this paper, we suggest an experimental method to convert visible single photons from a defect center in diamond to the near infrared. The conversion relies on efficient absorption by colloidal quantum dots and subsequent Stokes-shifted emission. The desired target wavelength can be chosen almost arbitrarily by selecting quantum dots with a suitable emission spectrum. A hollow core photonic crystal fiber selectively filled with a solution of quantum dots was used to achieve at the same time a single photon absorption probability of near unity and a very high re-collection efficiency of Stokes-shifted fluorescence (theoretically estimated to be 26%). A total conversion efficiency of light of 0.1% is achieved. Experimental strategies to significantly enhance this number are presented.

  18. Improved Rare-Earth Emitter Hollow Cathode

    Science.gov (United States)

    Goebel, Dan M.

    2011-01-01

    An improvement has been made to the design of the hollow cathode geometry that was created for the rare-earth electron emitter described in Compact Rare Earth Emitter Hollow Cathode (NPO-44923), NASA Tech Briefs, Vol. 34, No. 3 (March 2010), p. 52. The original interior assembly was made entirely of graphite in order to be compatible with the LaB6 material, which cannot be touched by metals during operation due to boron diffusion causing embrittlement issues in high-temperature refractory materials. Also, the graphite tube was difficult to machine and was subject to vibration-induced fracturing. This innovation replaces the graphite tube with one made out of refractory metal that is relatively easy to manufacture. The cathode support tube is made of molybdenum or molybdenum-rhenium. This material is easily gun-bored to near the tolerances required, and finish machined with steps at each end that capture the orifice plate and the mounting flange. This provides the manufacturability and robustness needed for flight applications, and eliminates the need for expensive e-beam welding used in prior cathodes. The LaB6 insert is protected from direct contact with the refractory metal tube by thin, graphite sleeves in a cup-arrangement around the ends of the insert. The sleeves, insert, and orifice plate are held in place by a ceramic spacer and tungsten spring inserted inside the tube. To heat the cathode, an insulating tube is slipped around the refractory metal hollow tube, which can be made of high-temperature materials like boron nitride or aluminum nitride. A screw-shaped slot, or series of slots, is machined in the outside of the ceramic tube to constrain a refractory metal wire wound inside the slot that is used as the heater. The screw slot can hold a single heater wire that is then connected to the front of the cathode tube by tack-welding to complete the electrical circuit, or it can be a double slot that takes a bifilar wound heater with both leads coming out

  19. Single-photon superradiance from a quantum dot

    DEFF Research Database (Denmark)

    Tighineanu, Petru; Daveau, Raphaël Sura; Lehmann, Tau Bernstorff

    2016-01-01

    We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron...... temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies....

  20. Formation of compressed flat electron beams with high transverse-emittance ratios

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J. [Fermilab; Institute of Fluid Physics, CAEP, China; Piot, P. [Northern Illinois University; Fermilab; Mihalcea, D. [Northern Illinois University; Prokop, C. R. [Northern Illinois University

    2014-08-01

    Flat beams—beams with asymmetric transverse emittances—have important applications in novel light-source concepts and advanced-acceleration schemes and could possibly alleviate the need for damping rings in lepton colliders. Over the last decade, a flat beam generation technique based on the conversion of an angular-momentum-dominated beam was proposed and experimentally tested. In this paper we explore the production of compressed flat beams. We especially investigate and optimize the flat beam transformation for beams with substantial fractional energy spread. We use as a simulation example the photoinjector of Fermilab’s Advanced Superconducting Test Accelerator. The optimizations of the flat beam generation and compression at Advanced Superconducting Test Accelerator were done via start-to-end numerical simulations for bunch charges of 3.2 nC, 1.0 nC, and 20 pC at ~37 MeV. The optimized emittances of flat beams with different bunch charges were found to be 0.25 μm (emittance ratio is ~400), 0.13 μm, 15 nm before compression, and 0.41 μm, 0.20 μm, 16 nm after full compression, respectively, with peak currents as high as 5.5 kA for a 3.2-nC flat beam. These parameters are consistent with requirements needed to excite wakefields in asymmetric dielectric-lined waveguides or produce significant photon flux using small-gap micro-undulators.

  1. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    CERN Document Server

    Hofmann, T; Bosco, A.; Bravin, E.; Gibson, S.M.; Kruchinin, K.O.; Raich, U.; Roncarolo, F.; Zocca, F.

    2016-01-01

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H- ions to 160 MeV. To measure the transverse emittance of the H- beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused through a thin slice of the H- beam. The laser photons have sufficient energy to detach the outer electron and create H0/e- pairs. In a downstream dipole, the created H0 particles are separated from the unstripped H- ions and their distribution is measured with a dedicated detector. By scanning the focused laser across the H- beam, the transverse emittance of the H- beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser

  2. Can galactic outflows explain the properties of Ly-alpha emitters?

    CERN Document Server

    Orsi, Alvaro; Baugh, Carlton M

    2011-01-01

    We study the properties of Ly-alpha emitters in a cosmological framework by computing the escape of Ly-alpha photons through galactic outflows. We combine the GALFORM semi-analytical model of galaxy formation with a Monte Carlo Ly-alpha radiative transfer code. The properties of Ly-alpha emitters at 0

  3. Controlling resonance energy transfer in nanostructure emitters by positioning near a mirror

    Science.gov (United States)

    Weeraddana, Dilusha; Premaratne, Malin; Gunapala, Sarath D.; Andrews, David L.

    2017-08-01

    The ability to control light-matter interactions in quantum objects opens up many avenues for new applications. We look at this issue within a fully quantized framework using a fundamental theory to describe mirror-assisted resonance energy transfer (RET) in nanostructures. The process of RET communicates electronic excitation between suitably disposed donor and acceptor particles in close proximity, activated by the initial excitation of the donor. Here, we demonstrate that the energy transfer rate can be significantly controlled by careful positioning of the RET emitters near a mirror. The results deliver equations that elicit new insights into the associated modification of virtual photon behavior, based on the quantum nature of light. In particular, our results indicate that energy transfer efficiency in nanostructures can be explicitly expedited or suppressed by a suitably positioned neighboring mirror, depending on the relative spacing and the dimensionality of the nanostructure. Interestingly, the resonance energy transfer between emitters is observed to "switch off" abruptly under suitable conditions of the RET system. This allows one to quantitatively control RET systems in a new way.

  4. Lyman-alpha spectral properties of five newly discovered Lyman continuum emitters

    CERN Document Server

    Verhamme, A; Schaerer, D; Izotov, Y; Worseck, G; Thuan, T X; Guseva, N

    2016-01-01

    We have recently reported the discovery of five low redshift Lyman continuum (LyC) emitters (LCEs, hereafter) with absolute escape fractions fesc(LyC) ranging from 6 to 13%, higher than previously found, and which more than doubles the number of low redshift LCEs.We use these observations to test theoretical predictions about a link between the characteristics of the Lyman-alpha (Lya) line from galaxies and the escape of ionising photons. We analyse the Lya spectra of eight LCEs of the local Universe observed with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope (our five leakers and three galaxies from the litterature), and compare their strengths and shapes to the theoretical criteria and comparison samples of local galaxies: the Lyman Alpha Reference Survey, Lyman Break Analogs, Green Peas, and the high-redshift strong LyC leaker Ion2. Our LCEs are found to be strong Lya emitters, with high equivalent widths, EW(Lya)> 70 {\\AA}, and large Lya escape fractions, fesc(Lya) > 20%. The Lya prof...

  5. Boron difluoride complexes of 2‧-hydroxychalcones and curcuminoids as fluorescent dyes for photonic applications

    Science.gov (United States)

    D'Aléo, Anthony; Felouat, Abdellah; Fages, Frédéric

    2015-03-01

    The field of fluorescent boron complexes has witnessed tremendous developments in recent years. In that context, we have investigated two series of boron difluoride complexes based on 2‧-hydroxychalcone and curcuminoid ligands that represent naturally occurring pigment structures. The dyes display significantly large Stokes shift values, indicating that an ICT state is involved as lower-energy state in the singlet manifold. Remarkably they are also fluorescent in the solid-state, with emission wavelengths usually in the visible and mainly in the near infrared (NIR). It is especially intriguing that those dyes experience strong π-interactions in the crystal phase. We have observed that the formation of those highly stacked structures was not detrimental to solid-state emission and could even be exploited for the generation of efficient NIR emitters. For example, the boron complexes of curcuminoid ligands can be used to generate NIR fluorescent organic nanoparticles with large cross sections for two-photon absorption. The design of organic dyes displaying NIR emission in solution or in the solid-state remains challenging for applications in bioimaging and organic photonics. Invited talk at the 7th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2014, 2-6 November, 2014, Ha Long, Vietnam.

  6. ESRF-type lattice design and optimization for the High Energy Photon Source

    Science.gov (United States)

    Xu, Gang; Jiao, Yi; Peng, Yue-Mei

    2016-02-01

    A new generation of storage ring-based light sources, called diffraction-limited storage rings (DLSRs), with emittance approaching the diffraction limit for multi-keV photons by means of multi-bend achromat lattices, has attracted extensive studies worldwide. Among various DLSR proposals, the hybrid multi-bend achromat concept developed at the European Synchrotron Radiation Facility (ESRF) predicts an effective way of minimizing the emittance while keeping the required chromatic sextupole strengths to an achievable level. For the High Energy Photon Source planned to be built in Beijing, an ESRF-type lattice design consisting of 48 hybrid seven-bend achromats is proposed to reach emittance as low as 60 pm·rad with a circumference of about 1296 m. Sufficient dynamic aperture, allowing vertical on-axis injection, and moderate momentum acceptance are achieved simultaneously for a promising ring performance. Supported by NSFC (11475202, 11405187) and Youth Innovation Promotion Association CAS (2015009)

  7. Photonics meet digital art

    Science.gov (United States)

    Curticapean, Dan; Israel, Kai

    2014-09-01

    The paper focuses on the work of an interdisciplinary project between photonics and digital art. The result is a poster collection dedicated to the International Year of Light 2015. In addition, an internet platform was created that presents the project. It can be accessed at http://www.magic-of-light.org/iyl2015/index.htm. From the idea to the final realization, milestones with tasks and steps will be presented in the paper. As an interdisciplinary project, students from technological degree programs were involved as well as art program students. The 2015 Anniversaries: Alhazen (1015), De Caus (1615), Fresnel (1815), Maxwell (1865), Einstein (1905), Penzias Wilson, Kao (1965) and their milestone contributions in optics and photonics will be highlighted.

  8. Emittance measurement at the NSLS x-ray ring

    Energy Technology Data Exchange (ETDEWEB)

    Safranek, J.; Stefan, P.M.

    1996-12-31

    A pinhole camera for imaging x-ray synchrotron radiation from a dipole magnet is now in operation at the NSLS X-Ray Ring. The pinhole camera detector is a 0.5 mm thick YAG phosphor screen viewed by a video camera. Both the theoretical pinhole diffraction pattern and the measured modulation transfer function (MTF) of the phosphor and camera have been deconvolved from the measured profile in order to derive the true transverse profile of the electron beam. This profile was then fit to a 2-dimensional Gaussian. The electron beam emittance as a function of the phase space acceptance of the pinhole camera has been derived, so the horizontal and vertical electron emittances can be deduced from the major and minor sigmas of the fit Gaussian. In the X-Ray Ring, the vertical emittance is kept small to maximize the synchrotron radiation brightness. The ratio of the measured vertical to horizontal emittance is 0.001.

  9. CSR-induced emittance growth in achromats: Linear formalism revisited

    Science.gov (United States)

    Venturini, M.

    2015-09-01

    We review the R-matrix formalism used to describe Coherent Synchrotron Radiation (CSR)-induced projected emittance growth in electron beam transport lines and establish the connection with a description in terms of the dispersion-invariant function.

  10. Design rules for core/shell nanowire resonant emitters

    Science.gov (United States)

    Kim, Da-Som; Kim, Sun-Kyung

    2017-01-01

    We study design principles to boost the extraction of light from core/shell GaN nanowire optical emitters. A full-vectorial electromagnetic simulation reveals that the extraction efficiency of an emitter within a nanowire cavity depends strongly on its position; the efficiency becomes maximized as the emitter's location approaches the center of the structure. The total extraction of light is sinusoidally modulated by the nanowire diameter, which is directly correlated with optical resonances. The introduction of a conformal dielectric coating on a nanowire leads to a dramatic enhancement in the extraction efficiency, which results from an increase in side emission owing to an optical antenna effect. A simple high-refractive-index dielectric coating approximately doubles the total extraction efficiency of a nanowire LED. These numerical findings will be valuable in providing strategies for high-efficiency nanowire-based optical emitters.

  11. CSR-induced emittance growth in achromats: Linear formalism revisited

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M.

    2015-09-11

    We review the R-matrix formalism used to describe Coherent Synchrotron Radiation (CSR)-induced projected emittance growth in electron beam transport lines and establish the connection with a description in terms of the dispersion-invariant function.

  12. Emittance Scanner Optimization for Low Energy Ion Beams

    CERN Document Server

    Stockli, Martin P

    2005-01-01

    Ion beam emittances are normally measured as two-dimensional distributions of the beam current fraction within a window dx centered at position coordinate x and a window dx' centered at trajectory angle x'. Unthresholded rms emittances evaluated from experimental data are very sensitive to noise, bias, and other undesired signals. Undesired signals occur when particles from outside the measured window dx*dx' contribute to the signal from the particles within the measured window. Increasing the window size increases the desired signal while most undesired contributions remain unchanged. However, the decreasing resolution causes an error in the emittance results, especially in the rms emittance. Using theoretical distributions we will present the tradeoff between resolution and accuracy.

  13. Emittance of TD-NiCr after simulated reentry

    Science.gov (United States)

    Clark, R. K.; Dicus, D. L.; Lisagor, W. B.

    1978-01-01

    The effects of simulated reentry heating on the emittance of TD-NiCr were investigated. Groups of specimens with three different preconditioning treatments were exposed to 6, 24, and 30 half-hour simulated reentry exposure cycles in a supersonic arc tunnel at each of three conditions intended to produce surface temperatures of 1255, 1365, and 1475 K. Emittance was determined at 1300 K on specimens which were preconditioned only and specimens after completion of reentry simulation exposure. Oxide morphology and chemistry were studied by scanning electron microscopy and X-ray diffraction analysis. A consistent relationship was established between oxide morphology and total normal emittance. Specimens with coarser textured oxides tended to have lower emittances than specimens with finer textured oxides.

  14. Transverse emittance measurement at REGAE via a solenoid scan

    Energy Technology Data Exchange (ETDEWEB)

    Hachmann, Max

    2012-12-15

    The linear accelerator REGAE at DESY produces short and low charged electron bunches, on the one hand to resolve the excitation transitions of atoms temporally by pump probe electron diffraction experiments and on the other hand to investigate principal mechanisms of laser plasma acceleration. For both cases a high quality electron beam is required. A quantity to rate the beam quality is the beam emittance. In the course of this thesis transverse emittance measurements by a solenoid scan could be realized and beyond that an improved theoretical description of a solenoid was successful. The foundation of emittance measurements are constituted by theoretical models which describe the envelope of a beam. Two different models were derived. The first is an often used model to determine the transverse beam emittance without considering space charge effects. More interesting and challenging was the development of an envelope model taking space charge effects into account. It is introduced and cross checked with measurements and simulations.

  15. Nanostructure-induced distortion in single-emitter microscopy

    CERN Document Server

    Lim, Kangmook; Fourkas, John; Shapiro, Benjamin; Waks, Edo

    2016-01-01

    Single-emitter microscopy has emerged as a promising method of imaging nanostructures with nanoscale resolution. This technique uses the centroid position of an emitters far-field radiation pattern to infer its position to a precision that is far below the diffraction limit. However, nanostructures composed of high-dielectric materials such as noble metals can distort the far-field radiation pattern. Nanoparticles also exhibit a more complex range of distortions, because in addition to introducing a high dielectric surface, they also act as efficient scatterers. Thus, the distortion effects of nanoparticles in single-emitter microscopy remains poorly understood. Here we demonstrate that metallic nanoparticles can significantly distort the accuracy of single-emitter imaging at distances exceeding 300 nm. We use a single quantum dot to probe both the magnitude and the direction of the metallic nanoparticle-induced imaging distortion and show that the diffraction spot of the quantum dot can shift by more than 35...

  16. Field emitters made of the contacted ytterbium and carbon nanolayers

    Directory of Open Access Journals (Sweden)

    G.G. Sominski

    2015-10-01

    Full Text Available The operation of field emitters of a new type prepared from contacted nanolayers of ytterbium and carbon has been investigated. The performed calculations and experiments allowed to optimize the emission characteristics of the emitters. The calculations took into account the existence of a transition zone between the layers of Yb and C. Emission characteristics of the cathodes including up to 40 pairs of layers of carbon and ytterbium with optimum thicknesses of 5 and 2 nm respectively were measured. The created multilayered emitters provide the average emission current density over the surface of the emitter up to 10–20 A/cm2 and show promise for use in miniature electronic devices.

  17. FXR LIA Optimization - Time-resolved OTR Emittance Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, J; Ong, M; Wargo, P; LeSage, G

    2005-07-21

    The Flash X-Ray Radiography (FXR) facility at Lawrence Livermore National Laboratory utilizes a high current, long pulse linear induction accelerator to produce high doses of x-ray radiation. Accurate characterization of the transverse beam emittance is required in order to facilitate accelerator modeling and tuning efforts and, ultimately, to optimize the final focus spot size, yielding higher resolution radiographs. In addition to conventional magnet scan, pepper-pot, and multiple screen techniques, optical transition radiation (OTR) has been proven as a useful emittance measurement diagnostic and is particularly well suited to the FXR accelerator. We shall discuss the time-resolved emittance characterization of an induction linac electron beam using OTR, and we will present our experimental apparatus and analysis software. We shall also develop the theoretical background of beam emittance and transition radiation.

  18. Optimization of Metamaterial Selective Emitters for Use in Thermophotovoltaic Applications

    Science.gov (United States)

    Pfiester, Nicole A.

    The increasing costs of fossil fuels, both financial and environmental, has motivated many to look into sustainable energy sources. Thermophotovoltaics (TPVs), specialized photovoltaic cells focused on the infrared range, offer an opportunity to achieve both primary energy capture, similar to traditional photovoltaics, as well as secondary energy capture in the form of waste heat. However, to become a feasible energy source, TPV systems must become more efficient. One way to do this is through the development of selective emitters tailored to the bandgap of the TPV diode in question. This thesis proposes the use of metamaterial emitters as an engineerable, highly selective emitter that can withstand the temperatures required to collect waste heat. Metamaterial devices made of platinum and a dielectric such as alumina or silicon nitride were initially designed and tested as perfect absorbers. High temperature robustness testing demonstrates the device's ability to withstand the rigors of operating as a selective emitter.

  19. Scanning Anode Field Emission Characterisation of Carbon Nanotube emitter arrays

    NARCIS (Netherlands)

    Berhanu, S.; Gröning, O.; Chen, Z.; Merikhi, J.; Bachmann, P.K.

    2011-01-01

    Scanning anode field emission microscopy (SAFEM) was used to characterise carbon nanotube (CNT) emitter arrays produced within Philips CediX-Technotubes' activities. Four different samples were investigated and compared. The field enhancement distributions were determined and the local field

  20. Beam Emittance Measurement for PLS-II Linac

    CERN Document Server

    Lee, Byung-Joon; Park, Chong do; Chunjarean, SomJai; Kim, Changbum

    2016-01-01

    The PLS-II has a 100 MeV pre-injector for the 3 GeV Linac. A thermionic gun produces electron charge of 200 pC with a bunch duration of 500 ps by a 250 ps triggering pulser. At the pre-injector, one of the most important beam parameters to identify the beam quality is a transverse emittance of electron bunches. Therefore we measure the beam emittance and twiss functions at 100 MeV in order to match the beam optics to beam transport line and go through it to the storage ring. To get the transverse emittance measurement, well-known technique, quadrupole scan, is used at the pre-injector. The emittance were 0.591 mm-mrad in horizontal and 0.774 mm-mrad in vertical direction.

  1. Transverse Emittance Measurement and Preservation at the LHC

    CERN Document Server

    AUTHOR|(CDS)2082907

    The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation will be discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constra...

  2. Intelligent Variable Emittance Panels Using New, ?True? Solid Electrolyte Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This firm has, in ongoing work in collaboration with the Air Force, NASA and JPL, developed a unique Variable Emittance technology based on the electrochromism of...

  3. Attribute measure recognition approach and its applications to emitter recognition

    Institute of Scientific and Technical Information of China (English)

    GUAN Xin; HE You; YI Xiao

    2005-01-01

    This paper studies the emitter recognition problem. A new recognition method based on attribute measure for emitter recognition is put forward. The steps of the method are presented. The approach to determining the weight coefficient is also discussed. Moreover, considering the temporal redundancy of emitter information detected by multi-sensor system, this new recognition method is generalized to multi-sensor system. A method based on the combination of attribute measure and D-S evidence theory is proposed. The implementation of D-S reasoning is always restricted by basic probability assignment function. Constructing basic probability assignment function based on attribute measure is presented in multi-sensor recognition system. Examples of recognizing the emitter purpose and system are selected to demonstrate the method proposed. Experimental results show that the performance of this new method is accurate and effective.

  4. Transverse emittance measurement at REGAE via a solenoid scan

    Energy Technology Data Exchange (ETDEWEB)

    Hachmann, Max

    2012-12-15

    The linear accelerator REGAE at DESY produces short and low charged electron bunches, on the one hand to resolve the excitation transitions of atoms temporally by pump probe electron diffraction experiments and on the other hand to investigate principal mechanisms of laser plasma acceleration. For both cases a high quality electron beam is required. A quantity to rate the beam quality is the beam emittance. In the course of this thesis transverse emittance measurements by a solenoid scan could be realized and beyond that an improved theoretical description of a solenoid was successful. The foundation of emittance measurements are constituted by theoretical models which describe the envelope of a beam. Two different models were derived. The first is an often used model to determine the transverse beam emittance without considering space charge effects. More interesting and challenging was the development of an envelope model taking space charge effects into account. It is introduced and cross checked with measurements and simulations.

  5. Transverse emittance investigation of the ISOLDE target ion sources

    CERN Document Server

    Lettry, Jacques; Wenander, F

    2003-01-01

    In order to produce target-ion sources allowing for a high isotopic resolution in the separator, CERN/ISOLDE (Isotope Separator On Line) has purchased a commercial emittance metre, capable of measuring transverse phase-space emittances for ion-beam intensities down to approximately 1 nA. It was installed at the ISOLDE off-line separator where targets are tested with respect to material purity and the ion-source efficiencies are determined. Now, also the emittance and brightness are measured for different stable elements. An extensive programme has been launched aiming at a complete survey of the emittance dependence on the various ion-source parameters. Results from the measurements on the different ISOLDE ion-source types, with associated analysis, are presented.

  6. Analysis of measured radar data for specific emitter identification

    CSIR Research Space (South Africa)

    Conning, M

    2010-05-01

    Full Text Available of emitters. The processes developed are pulse extraction, feature calculation, dimensionality reduction and classification. A pulse is detected whenever the phase changes from being random to being linear. Time domain features are then calculated from...

  7. Rare Earth Doped High Temperature Ceramic Selective Emitters

    Science.gov (United States)

    Chubb, Donald L.; Pal, AnnaMarie; Patton, Martin O.; Jenkins, Phillip P.

    1999-01-01

    As a result of their electron structure, rare earth ions in crystals at high temperature emit radiation in several narrow bands rather than in a continuous blackbody manner. This study develops a spectral emittance model for films of rare earth containing materials. Although there are several possible rare earth doped high temperature materials, this study was confined to rare earth aluminum garnets. Good agreement between experimental and theoretical spectral emittances was found for erbium, thulium and erbium-holmium aluminum garnets. Spectral emittances of these films are sensitive to temperature differences across the film. Emitter efficiency is also a sensitive function of temperature. For thulium aluminum garnet the efficiency is 0.38 at 1700 K but only 0.19 at 1262 K.

  8. Absolute beam emittance measurements at RHIC using ionization profile monitors

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Connolly, R [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Summers, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  9. Innovative energy efficient low-voltage electron beam emitters

    Science.gov (United States)

    Felis, Kenneth P.; Avnery, Tovi; Berejka, Anthony J.

    2002-03-01

    Advanced electron beams (AEB) has developed a modular, low voltage (80-125 keV), high beam current (up to 40 ma), electron emitter with typically 25 cm of beam width, that is housed in an evacuated, returnable chamber that is easy to plug in and connect. The latest in nanofabrication enables AEB to use an ultra-thin beam window. The power supply for AEB's emitter is based on solid-state electronics. This combination of features results in a remarkable electrical efficiency. AEB's electron emitter relies on a touch screen, computer control system. With 80 μm of unit density beam penetration, AEB's electron emitter has gained market acceptance in the curing of opaque, pigmented inks and coatings used on flexible substrates, metals and fiber composites and in the curing of adhesives in foil based laminates.

  10. Progress on the emitter wrap-through silicon solar cell

    Science.gov (United States)

    Gee, J. M.; Buck, M. E.; Schubert, W. K.; Basore, P. A.

    The Emitter Wrap-Through (EWT) solar cell is a back-contacted solar cell with a carrier-collection junction (emitter) on the front surface. Elimination of grids from the front surface allows for higher performance by eliminating grid-obscuration losses and reducing series resistance, while keeping an emitter on the front surface maintains high collection efficiency in solar-grade materials with modest diffusion lengths. The EWT cell uses laser-drilled vias to wrap the emitter diffusion on the front surface to interdigitated contacts on the back surface. We report on progress towards demonstration of two concepts for the EWT cell. The first EWT concept uses a fabrication sequence based on heavily diffused grooves and plated metallizations, and the second EWT concept uses a single furnace step and screen-printed metallizations. We also report on demonstration of double-sided carrier collection in the EWT cell.

  11. Beam dynamics in rf guns and emittance correction techniques

    Science.gov (United States)

    Serafini, Luca

    1994-02-01

    In this paper we present a general review of beam dynamics in a laser-driven rf gun. The peculiarity of such an accelerating structure versus other conventional multi-cell linac structures is underlined on the basis of the Panofsky-Wenzel theorem, which is found to give a theoretical background for the well known Kim's model. A basic explanation for some proposed methods to correct rf induced emittance growth is also derived from the theorem. We also present three emittance correction techniques for the recovery of space-charge induced emittance growth, namely the optimum distributed disk-like bunch technique, the use of rf spatial harmonics to correct spherical aberration induced by space charge forces and the technique of emittance filtering by clipping the electron beam. The expected performances regarding the beam quality achievable with different techniques, as predicted by scaling laws and simulations, are analyzed, and, where available, compared to experimental results.

  12. Novalike Cataclysmic Variables are Significant Radio Emitters

    CERN Document Server

    Coppejans, Deanne L; Miller-Jones, James C A; Rupen, Michael P; Knigge, Christian; Sivakoff, Gregory R; Groot, Paul J

    2015-01-01

    Radio emission from non-magnetic cataclysmic variables (CVs, accreting white dwarfs) could allow detailed studies of outflows and possibly accretion flows in these nearby, numerous and non-relativistic compact accretors. Up to now, however, very few CVs have been detected in the radio. We have conducted a VLA pilot survey of four close and optically-bright novalike CVs at 6 GHz, detecting three, and thereby doubling the number of radio detections of these systems. RW Sex, V603 Aql and the old nova TT Ari were detected in both of the epochs, while V1084 Her was not detected (to a $3\\sigma$ upper-limit of 7.8 $\\mu\\rm{Jy}\\,\\rm{beam}^{-1}$). These observations clearly show that the sensitivity of previous surveys was typically too low to detect these objects and that non-magnetic CVs can indeed be significant radio emitters. The three detected sources show a range of properties, including flaring and variability on both short ($\\sim$200 s) and longer-term (days) time-scales, as well as circular polarization level...

  13. Sources of Emittance in RF Photocathode Injectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, David [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2016-12-11

    Advances in electron beam technology have been central to creating the current generation of x-ray free electron lasers and ultra-fast electron microscopes. These once exotic devices have become essential tools for basic research and applied science. One important beam technology for both is the electron source which, for many of these instruments, is the photocathode RF gun. The invention of the photocathode gun and the concepts of emittance compensation and beam matching in the presence of space charge and RF forces have made these high-quality beams possible. Achieving even brighter beams requires a taking a finer resolution view of the electron dynamics near the cathode during photoemission and the initial acceleration of the beam. In addition, the high brightness beam is more sensitive to degradation by the optical aberrations of the gun’s RF and magnetic lenses. This paper discusses these topics including the beam properties due to fundamental photoemission physics, space charge effects close to the cathode, and optical distortions introduced by the RF and solenoid fields. Analytic relations for these phenomena are derived and compared with numerical simulations.

  14. Molecular hydrogen in Lyman Alpha Emitters

    CERN Document Server

    Vallini, Livia; Ferrara, Andrea

    2012-01-01

    We present a physically motivated model to estimate the molecular hydrogen (H2) content of high-redshift (z~5.7,6.6) Lyman Alpha Emitters (LAEs) extracted from a suite of cosmological simulations. We find that the H2 mass fraction, (f_H2), depends on three main LAE physical properties: (a) star formation rate, (b) dust mass, and (c) cold neutral gas mass. At z~5.7, the value of f_H2 peaks and ranges between 0.5-0.9 for intermediate mass LAEs with stellar mass M_* ~ 10^{9-10} solar mass, decreasing for both smaller and larger galaxies. However, the largest value of the H2 mass is found in the most luminous LAEs. These trends also hold at z\\sim6.6, although, due to a lower dust content, f_H2(z=6.6)\\sim0.5 f_H2(z=5.7) when averaged over all LAEs; they arise due to the interplay between the H2 formation/shielding controlled by dust and the intensity of the ultraviolet (UV) Lyman-Werner photo-dissociating radiation produced by stars. We then predict the carbon monoxide (CO) luminosities for such LAEs and check tha...

  15. Nonradiating and radiating modes excited by quantum emitters in open epsilon-near-zero cavities

    CERN Document Server

    Liberal, Iñigo

    2015-01-01

    Controlling the emission and interaction properties of quantum emitters (QEs) embedded within an optical cavity is a key technique in engineering light-matter interactions at the nanoscale, as well as in the development of quantum information processing. State-of-the-art optical cavities are based on high Q photonics crystals and dielectric resonators. However, wealthier responses might be attainable with cavities carved in more exotic materials. Here, we theoretically investigate the emission and interaction properties of QEs embedded in open epsilon-near-zero (ENZ) cavities. Using analytical methods and numerical simulations, it is demonstrated that open ENZ cavities present the unique property of supporting nonradiating modes independently of the geometry of the external boundary of the cavity (shape, size, topology...). Moreover, the possibility of switching between radiating and nonradiating modes enables a dynamic control of both the emission by, and the interaction between, QEs. These phenomena provide...

  16. Probing the local density of states in three dimensions with a scanning single quantum emitter

    CERN Document Server

    Schell, Andreas W; Benson, Oliver

    2013-01-01

    Their intrinsic properties render single quantum systems as ideal tools for quantum enhanced sensing and microscopy. As an additional benefit, their size is typically on an atomic scale which enables sensing with very high spatial resolution. Here, we report on utilizing a single nitrogen vacancy center in nanodiamond for performing three-dimensional scanning-probe fluorescence lifetime imaging microscopy. By measuring changes of the single emitter's lifetime information on the local density of optical states is acquired at the nanoscale. This technique to gather information on the local density of optical states is important for the understanding of fundamental quantum optical processes as well as for the engineering of novel photonic and plasmonic devices.

  17. Absorption and emission properties of photonic crystals and metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Lili [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    We study the emission and absorption properties of photonic crystals and metamaterials using Comsol Multiphysics and Ansoft HFSS as simulation tools. We calculate the emission properties of metallic designs using drude model and the results illustrate that an appropriate termination of the surface of the metallic structure can significantly increase the absorption and therefore the thermal emissivity. We investigate the spontaneous emission rate modifications that occur for emitters inside two-dimensional photonic crystals and find the isotropic and directional emissions with respect to different frequencies as we have expected.

  18. Nanofabrication of Plasmonic Circuits Containing Single Photon Sources

    DEFF Research Database (Denmark)

    Siampour Ashkavandi, Hamidreza; Kumar, Shailesh; Bozhevolnyi, Sergey I.

    2017-01-01

    -photon emitters, using electron-beam lithography of hydrogen silsesquioxane (HSQ) resist on silver-coated silicon substrates. A propagation length of 20 ± 5 μm for the NV single-photon emission is measured with DLSPPWs. A 5-fold enhancement in the total decay rate, and 58% coupling efficiency to the DLSPPW mode...... is achieved, indicating significant mode confinement. Finally, we demonstrate routing of single plasmons with DLSPPW-based directional couplers, revealing the potential of our approach for on-chip realization of quantum optical networks....

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

    Science.gov (United States)

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

    2016-04-18

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

  20. A Program to Generate a Particle Distribution from Emittance Measurements

    CERN Document Server

    Bouma, DS; Lallement, JB

    2010-01-01

    We have written a program to generate a particle distribution based on emittance measurements in x-x’ and y-y’. The accuracy of this program has been tested using real and constructed emittance measurements. Based on these tests, the distribution generated by the program can be used to accurately simulate the beam in multi-particle tracking codes, as an alternative to a Gaussian or uniform distribution.

  1. Minimum emittance of isochronus rings for synchrotron light source

    CERN Document Server

    Shoji, Y

    1999-01-01

    Theoretically achievable minimum emittances of isochronus rings for synchrotron light source are calculated. The rings discussed in this paper consist of isochronus and achromatic bending cells, isochronus TBA (triple bend achromat) cells with negative dispersion, isochronus TBA cells with inverse bends or isochronus QBA (four bend achromat) cells. We show that the minimum emittances of these rings are roughly 2 or 3 times of those of the optimized non-isochronus rings.

  2. Bulk molybdenum field emitters by inductively coupled plasma etching.

    Science.gov (United States)

    Zhu, Ningli; Cole, Matthew T; Milne, William I; Chen, Jing

    2016-12-07

    In this work we report on the fabrication of inductively coupled plasma (ICP) etched, diode-type, bulk molybdenum field emitter arrays. Emitter etching conditions as a function of etch mask geometry and process conditions were systematically investigated. For optimized uniformity, aspect ratios of >10 were achieved, with 25.5 nm-radius tips realised for masks consisting of aperture arrays some 4.45 μm in diameter and whose field electron emission performance has been herein assessed.

  3. Study of ultra-low emittance design for SPEAR3

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M. -H.; Huang, X.; Safranek, J.; /SLAC

    2015-09-17

    Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now, to further enhance the performance of SPEAR3, we are looking into the possibility of converting SPEAR3 to an ultra-low emittance storage ring within its site constraint.

  4. Emittance growth in the DARHT Axis-II Downstream Transport

    OpenAIRE

    Ekdahl, Carl; Schulze, Martin E.

    2017-01-01

    Using a particle-in-cell (PIC) code, we investigated the possibilities for emittance growth through the quadrupole magnets of the system used to transport the high-current electron beam from an induction accelerator to the bremsstrahlung converter target used for flash radiography. We found that even highly mismatched beams exhibited little emittance growth (< 6%), which we attribute to softening of their initial hard edge current distributions. We also used this PIC code to evaluate the accu...

  5. A Novel Depletion-Mode MOS Gated Emitter Shorted Thyristor

    Institute of Scientific and Technical Information of China (English)

    张鹤鸣; 戴显英; 张义门; 马晓华; 林大松

    2000-01-01

    A Novel MOS-gated thyristor, depletion-mode MOS gated emitter shorted thyristor (DMST),and its two structures are proposed. In DMST,the channel of depletion-mode MOS makes the thyristor emitter-based junction inherently short. The operation of the device is controlled by the interruption and recovery of the depletion-mode MOS P channel. The perfect properties have been demonstrated by 2-D numerical simulations and the tests on the fabricated chips.

  6. Quantum interference between two single photons emitted by independently trapped atoms.

    Science.gov (United States)

    Beugnon, J; Jones, M P A; Dingjan, J; Darquié, B; Messin, G; Browaeys, A; Grangier, P

    2006-04-06

    When two indistinguishable single photons are fed into the two input ports of a beam splitter, the photons will coalesce and leave together from the same output port. This is a quantum interference effect, which occurs because two possible paths-in which the photons leave by different output ports-interfere destructively. This effect was first observed in parametric downconversion (in which a nonlinear crystal splits a single photon into two photons of lower energy), then from two separate downconversion crystals, as well as with single photons produced one after the other by the same quantum emitter. With the recent developments in quantum information research, much attention has been devoted to this interference effect as a resource for quantum data processing using linear optics techniques. To ensure the scalability of schemes based on these ideas, it is crucial that indistinguishable photons are emitted by a collection of synchronized, but otherwise independent sources. Here we demonstrate the quantum interference of two single photons emitted by two independently trapped single atoms, bridging the gap towards the simultaneous emission of many indistinguishable single photons by different emitters. Our data analysis shows that the observed coalescence is mainly limited by wavefront matching of the light emitted by the two atoms, and to a lesser extent by the motion of each atom in its own trap.

  7. Two-photon photoemission from a copper cathode in an X -band photoinjector

    Science.gov (United States)

    Li, H.; Limborg-Deprey, C.; Adolphsen, C.; McCormick, D.; Dunning, M.; Jobe, K.; Raubenheimer, T.; Vrielink, A.; Vecchione, T.; Wang, F.; Weathersby, S.

    2016-02-01

    This paper presents two-photon photoemission from a copper cathode in an X -band photoinjector. We experimentally verified that the electron bunch charge from photoemission out of a copper cathode scales with laser intensity (I) square for 400 nm wavelength photons. We compare this two-photon photoemission process with the single photon process at 266 nm. Despite the high reflectivity (R ) of the copper surface for 400 nm photons (R =0.48 ) and higher thermal energy of photoelectrons (two-photon at 200 nm) compared to 266 nm photoelectrons, the quantum efficiency of the two-photon photoemission process (400 nm) exceeds the single-photon process (266 nm) when the incident laser intensity is above 300 GW /cm2 . At the same laser pulse energy (E ) and other experimental conditions, emitted charge scales inversely with the laser pulse duration. A thermal emittance of 2.7 mm-mrad per mm root mean square (rms) was measured on our cathode which exceeds by sixty percent larger compared to the theoretical predictions, but this discrepancy is similar to previous experimental thermal emittance on copper cathodes with 266 nm photons. The damage of the cathode surface of our first-generation X -band gun from both rf breakdowns and laser impacts mostly explains this result. Using a 400 nm laser can substantially simplify the photoinjector system, and make it an alternative solution for compact pulsed electron sources.

  8. Emittance minimization at the ELBE superconducting electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, K.; Arnold, A.; Lu, P.; Murcek, P.; Teichert, J.; Vennekate, H.; Xiang, R.

    2014-07-01

    The transverse emittance is one of the most important quantities which characterize the quality of an electron source. For high quality experiments low beam emittance is required. By means of theoretical considerations and simulation calculations we have studied how the emittance of the Rossendorf superconducting radio-frequency photoelectron source (SRF gun) can be minimized. It turned out that neither a solenoid magnet nor the effect of space charge forces is needed to create a pronounced emittance minimum. The minimum appears by just adjusting the starting phase of the electron bunch with respect to the RF phase of the gun in a suitable way. Investigation of various correlations between the properties of the beam particles led to an explanation on how the minimum comes about. It is shown that the basic mechanism of minimization is the fact that the longitudinal properties of the particles (energy) are strongly influenced by the starting phase. Due to the coupling of the longitudinal and transverse degrees of freedom by the relativistic equation of motion the transverse degrees of freedom and thereby the emittance can be strongly influenced by the starting phase as well. The results obtained in this study will be applied to minimize the emittance in the commissioning phase of the SRF gun.

  9. Electromagnetic compatibility of implantable neurostimulators to RFID emitters

    Directory of Open Access Journals (Sweden)

    Guag Joshua W

    2011-06-01

    Full Text Available Abstract Background The objective of this study is to investigate electromagnetic compatibility (EMC of implantable neurostimulators with the emissions from radio frequency identification (RFID emitters. Methods Six active implantable neurostimulators with lead systems were tested for susceptibility to electromagnetic fields generated by 22 RFID emitters. These medical devices have been approved for marketing in the U.S. for a number of intended uses that include: epilepsy, depression, incontinence, Parkinsonian tremor and pain relief. Each RFID emitter had one of the following carrier frequencies: 125 kHz, 134 kHz, 13.56 MHz, 433 MHz, 915 MHz and 2.45 GHz Results The test results showed the output of one of the implantable neurostimulators was inhibited by 134 kHz RFID emitter at separation distances of 10 cm or less. The output of the same implantable neurostimulator was also inhibited by another 134 kHz RFID emitter at separation distances of 10 cm or less and also showed inconsistent pulsing rate at a separation distance of 15 cm. Both effects occurred during and lasted through out the duration of the exposure. Conclusions The clinical significance of the effects was assessed by a clinician at the U.S. Food and Drug Administration. The effects were determined to be clinically significant only if they occurred for extended period of time. There were no observed effects from the other 5 implantable neurostimulators or during exposures from other RFID emitters.

  10. Electromagnetic compatibility of implantable neurostimulators to RFID emitters.

    Science.gov (United States)

    Pantchenko, Oxana S; Seidman, Seth J; Guag, Joshua W; Witters, Donald M; Sponberg, Curt L

    2011-06-09

    The objective of this study is to investigate electromagnetic compatibility (EMC) of implantable neurostimulators with the emissions from radio frequency identification (RFID) emitters. Six active implantable neurostimulators with lead systems were tested for susceptibility to electromagnetic fields generated by 22 RFID emitters. These medical devices have been approved for marketing in the U.S. for a number of intended uses that include: epilepsy, depression, incontinence, Parkinsonian tremor and pain relief. Each RFID emitter had one of the following carrier frequencies: 125 kHz, 134 kHz, 13.56 MHz, 433 MHz, 915 MHz and 2.45 GHz. The test results showed the output of one of the implantable neurostimulators was inhibited by 134 kHz RFID emitter at separation distances of 10 cm or less. The output of the same implantable neurostimulator was also inhibited by another 134 kHz RFID emitter at separation distances of 10 cm or less and also showed inconsistent pulsing rate at a separation distance of 15 cm. Both effects occurred during and lasted through out the duration of the exposure. The clinical significance of the effects was assessed by a clinician at the U.S. Food and Drug Administration. The effects were determined to be clinically significant only if they occurred for extended period of time. There were no observed effects from the other 5 implantable neurostimulators or during exposures from other RFID emitters.

  11. Fundamental limitations in spontaneous emission rate of single-photon sources

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Khurgin, Jacob B.

    2016-01-01

    The rate of single-photon generation by quantum emitters (QEs) can be enhanced by placing a QE inside a resonant structure. This structure can represent an all-dielectric micro-resonator or waveguide and thus be characterized by ultra-low loss and dimensions on the order of wavelength. Or it can ...

  12. Photonic homeostatics

    Science.gov (United States)

    Liu, Timon C.; Li, Fan-Hui

    2010-11-01

    Photonic homeostatics is a discipline to study the establishment, maintenance, decay, upgrading and representation of function-specific homoestasis (FSH) by using photonics. FSH is a negative-feedback response of a biosystem to maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stress may increase sirtuin 1 (SIRT1) activities above FSH-specific SIRT1 activity to induce a function far from its FSH. On the one hand, low level laser irradiation or monochromatic light (LLL) can not modulate a function in its FSH or a stress in its stress-specific homeostasis (StSH), but modulate a function far from its FSH or a stress far from its StSH. On the other hand, the biophotons from a biosystem with its function in its FSH should be less than the one from the biosystem with its function far from its FSH. The non-resonant interaction of low intensity laser irradiation or monochromatic light (LIL) and a kind of membrane protein can be amplified by all the membrane proteins if the function is far from its FSH. This amplification might hold for biophoton emission of the membrane protein so that the photonic spectroscopy can be used to represent the function far from its FSH, which is called photonomics.

  13. Radiotoxicity induced by Auger electron emitters in human osteosarcoma cell line using comet assay

    Institute of Scientific and Technical Information of China (English)

    XU Yu-Jie; LI Qing-Nuan; ZHU Ran; ZHU Ben-Xing; ZHANG Yong-Ping; ZHANG Xiao-Dong; FAN Wo; HONG Cheng-Jiao; LI Wen-Xin

    2003-01-01

    The comet assay (single cell gel electrophoresis assay) was used to evaluate the radiotoxicity of Augerelectron emitters in the human osteosarcoma cell line (HOS-8603). After internal exposure to 67Ga-EDTMP, the sar-coma cell has been injured severely. The comet length was longer along with the increase of dose, the appearance ofcomet tail was different from that with respect to the 60Co γ-ray irradiation. DNA damage of cell was mainly due tothe radiation effect of Auger electrons. The 67Ga may be a therapeutic radionuclide with good prospect for tumortreatment and palliation of bone pain induced by metastasis.

  14. Beam Emittance Measurement with Laser Wire Scanners in the ILC Beam Delivery System

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, I.; /CERN; Blair, G.A.; /Royal Holloway, U. of London; Woodley, M.; /SLAC

    2008-02-01

    Accurate measurement of the beam phase-space is essential for the next generation of electron accelerators. A scheme for beam optics optimization and beam matrix reconstruction algorithms for the diagnostics section of the beam delivery system of the International Linear Collider based on laser-wire beam profile monitors are discussed. Possible modes of operation of the laser-wire system together with their corresponding performance are presented. Based on these results, prospects for reconstructing the ILC beam emittance from representative laser-wire beam size measurements are evaluated.

  15. Silicon Carbide Emitter Turn-Off Thyristor

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2008-01-01

    Full Text Available A novel MOS-controlled SiC thyristor device, the SiC emitter turn-off thyristor (ETO is a promising technology for future high-voltage switching applications because it integrates the excellent current conduction capability of a SiC thyristor with a simple MOS-control interface. Through unity-gain turn-off, the SiC ETO also achieves excellent Safe Operation Area (SOA and faster switching speeds than silicon ETOs. The world's first 4.5-kV SiC ETO prototype shows a forward voltage drop of 4.26 V at 26.5 A/cm2 current density at room and elevated temperatures. Tested in an inductive circuit with a 2.5 kV DC link voltage and a 9.56-A load current, the SiC ETO shows a fast turn-off time of 1.63 microseconds and a low 9.88 mJ turn-off energy. The low switching loss indicates that the SiC ETO could operate at about 4 kHz if 100 W/cm2 conduction and the 100 W/cm2 turn-off losses can be removed by the thermal management system. This frequency capability is about 4 times higher than 4.5-kV-class silicon power devices. The preliminary demonstration shows that the SiC ETO is a promising candidate for high-frequency, high-voltage power conversion applications, and additional developments to optimize the device for higher voltage (>5 kV and higher frequency (10 kHz are needed.

  16. Photon properties of light in semiconductor microcavities

    Institute of Scientific and Technical Information of China (English)

    Guangcun SHAN; Wei HUANG

    2009-01-01

    Properties of atom-like emitters in cavities are successfully described by cavity quantum electrodynamics(cavity-QED).In this work,we focus on the issue of the steady-state and spectral properties of the light emitted by a driven microcavity containing a quantum well (QW) with the excitonic interactions using simulation of fully quantum-mechanical treatment.The system is coherently pumped with laser,and it is found that depending on the relative values of pumping rate of stimulated emission,either one or two peaks close to the excitation energy of the QW or to the natural frequency of the cavity are shown in the emission spectrum.Furthermore,the nonclassical proprieties of the emitted photon have been investigated.This excitonic system presents several dynamical and statistical similarities to the atomic system,in particular for the bad-cavity and good-cavity limits.The results show that the photon emission can be significantly amplified due to the coupling strength between a single emitter and radiation field in the microcavity,and it is concluded that the present semiconductor microcavity system may serve as a QW laser with low threshold.

  17. Single photon sources with single semiconductor quantum dots

    Science.gov (United States)

    Shan, Guang-Cun; Yin, Zhang-Qi; Shek, Chan Hung; Huang, Wei

    2014-04-01

    In this contribution, we briefly recall the basic concepts of quantum optics and properties of semiconductor quantum dot (QD) which are necessary to the understanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantum emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as optical properties of the QDs. We then review the localization of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and performances in terms of strong coupling regime, efficiency, directionality, and polarization control. Furthermore, we will discuss the recent progress on the fabrication of single photon sources, and various approaches for embedding single QDs into microcavities or photonic crystal nanocavities and show how to extend the wavelength range. We focus in particular on new generations of electrically driven QD single photon source leading to high repetition rates, strong coupling regime, and high collection efficiencies at elevated temperature operation. Besides, new developments of room temperature single photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for practical single-photon sources are also discussed.

  18. Nanostructure-Induced Distortion in Single-Emitter Microscopy

    Science.gov (United States)

    Lim, Kangmook; Ropp, Chad; Barik, Sabyasachi; Fourkas, John; Shapiro, Benjamin; Waks, Edo

    2016-09-01

    Single-emitter microscopy has emerged as a promising method of imaging nanostructures with nanoscale resolution. This technique uses the centroid position of an emitters far-field radiation pattern to infer its position to a precision that is far below the diffraction limit. However, nanostructures composed of high-dielectric materials such as noble metals can distort the far-field radiation pattern. Nanoparticles also exhibit a more complex range of distortions, because in addition to introducing a high dielectric surface, they also act as efficient scatterers. Thus, the distortion effects of nanoparticles in single-emitter microscopy remains poorly understood. Here we demonstrate that metallic nanoparticles can significantly distort the accuracy of single-emitter imaging at distances exceeding 300 nm. We use a single quantum dot to probe both the magnitude and the direction of the metallic nanoparticle-induced imaging distortion and show that the diffraction spot of the quantum dot can shift by more than 35 nm. The centroid position of the emitter generally shifts away from the nanoparticle position, in contradiction to the conventional wisdom that the nanoparticle is a scattering object that will pull in the diffraction spot of the emitter towards its center. These results suggest that dielectric distortion of the emission pattern dominates over scattering. We also show that by monitoring the distortion of the quantum dot diffraction spot we can obtain high-resolution spatial images of the nanoparticle, providing a new method for performing highly precise, sub-diffraction spatial imaging. These results provide a better understanding of the complex near-field coupling between emitters and nanostructures, and open up new opportunities to perform super-resolution microscopy with higher accuracy.

  19. Emittance and Phase Space Tomography for the Fermilab Linac

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, F.G.G.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moore, C.D.; /Fermilab; Newhart, D.L.; /Fermilab

    2012-05-01

    The Fermilab Linac delivers a variable intensity, 400-MeV beam to the MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a deconvolution of the profile data. Preliminary measurements using this diagnostic section are reported here. These data represent a first-pass measurement of the Linac emittance based on various techniques. It is clear that the most accurate representation of the emittance is given by the 3-profile approach. Future work will entail minimizing the beam spot size on MW5 to test and possibly improve the accuracy of the 2-profile approach. The 95% emittance is {approx} 18{pi} in the vertical and {approx} 13{pi} in the horizontal, which is especially larger than anticipated - 8-10{pi} was expected. One possible explanation is that the entire Linac pulse is extracted into the MTA beamline and during the first few microseconds, the feed forward and RF regulation are not stable. This may result in a larger net emittance observed versus beam injected into Booster, where the leading part of the Linac beam pulse is chopped. Future studies will clearly entail a measurement of the emittance vs. pulse length. One additional concern is that the Linac phase space is most likely aperture-defined and non-elliptical in nature. A non-elliptical phase-space determination would require a more elaborate analysis and provide another explanation of the

  20. Photonic-crystal fibre: Mapping the structure

    DEFF Research Database (Denmark)

    Markos, Christos

    2015-01-01

    The demonstration of real-time and non-destructive Doppler-assisted tomography of the internal structure of photonic-crystal fibres could aid the fabrication of high-quality fibres with enhanced performance.......The demonstration of real-time and non-destructive Doppler-assisted tomography of the internal structure of photonic-crystal fibres could aid the fabrication of high-quality fibres with enhanced performance....

  1. Nanowire photonics

    Directory of Open Access Journals (Sweden)

    Peter J. Pauzauskie

    2006-10-01

    Full Text Available The development of integrated electronic circuitry ranks among the most disruptive and transformative technologies of the 20th century. Even though integrated circuits are ubiquitous in modern life, both fundamental and technical constraints will eventually test the limits of Moore's law. Nanowire photonic circuitry constructed from myriad one-dimensional building blocks offers numerous opportunities for the development of next-generation optical information processors and spectroscopy. However, several challenges remain before the potential of nanowire building blocks is fully realized. We cover recent advances in nanowire synthesis, characterization, lasing, integration, and the eventual application to relevant technical and scientific questions.

  2. Portal Connecting Dark Photons and Axions

    Science.gov (United States)

    Kaneta, Kunio; Lee, Hye-Sung; Yun, Seokhoon

    2017-03-01

    The dark photon and the axion (or axionlike particle) are popular light particles of the hidden sector. Each of them has been actively searched for through the couplings called the vector portal and the axion portal. We introduce a new portal connecting the dark photon and the axion (axion-photon-dark photon, axion-dark photon-dark photon), which emerges in the presence of the two particles. This dark axion portal is genuinely new couplings, not just from a product of the vector portal and the axion portal, because of the internal structure of these couplings. We present a simple model that realizes the dark axion portal and discuss why it warrants a rich phenomenology.

  3. Transverse emittance measurement and preservation at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Maria

    2016-06-20

    The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle physics. The luminosity production is closely linked to emittance preservation in the accelerator. The transverse emittance is the phase space density of the beam and should be conserved when the particle beam is transformed through the accelerator. Perturbing effects, however, can lead to emittance increase and hence luminosity degradation. Measuring the emittance growth is a complex task with high intensity beams and changing energies. The machine optics and the transverse beam size have to be measured as accurately as possible. Beta function measurements with k-modulation are discussed. With this method the quadrupole focussing strength is varied and the resulting tune change is traced to determine the beta function at the quadrupole. A new k-modulation measurement tool was developed for the LHC. The fully automatic and online measurement system takes constraints of various systems such as tune measurement precision and powering limitations of the LHC superconducting circuits into account. With sinusoidal k-modulation record low beta function measurement uncertainties in the LHC have been reached. 2015 LHC beta function and β*, which is the beta function at the collision point, measurements with k-modulation will be presented. Wire scanners and synchrotron light monitors are presently used in the LHC to measure the transverse beam size. Accuracy and limitations of the LHC transverse profile monitors are discussed. During the 2012 LHC proton run it was found that wire scanner photomultiplier saturation added significant uncertainty on all measurements. A large discrepancy between emittances from wire scanners and luminosity was discovered but not solved. During Long Shutdown 1 the wire scanner system was upgraded with new photomultipliers. A thorough study of LHC wire scanner measurement precision in 2015 is presented

  4. A case for ZnO nanowire field emitter arrays in advanced x-ray source applications

    Science.gov (United States)

    Robinson, Vance S.; Bergkvist, Magnus; Chen, Daokun; Chen, Jun; Huang, Mengbing

    2016-09-01

    Reviewing current efforts in X-ray source miniaturization reveals a broad spectrum of applications: Portable and/or remote nondestructive evaluation, high throughput protein crystallography, invasive radiotherapy, monitoring fluid flow and particulate generation in situ, and portable radiography devices for battle-front or large scale disaster triage scenarios. For the most part, all of these applications are being addressed with a top-down approach aimed at improving portability, weight and size. That is, the existing system or a critical sub-component is shrunk in some manner in order to miniaturize the overall package. In parallel to top-down x-ray source miniaturization, more recent efforts leverage field emission and semiconductor device fabrication techniques to achieve small scale x-ray sources via a bottom-up approach where phenomena effective at a micro/nanoscale are coordinated for macro-scale effect. The bottom-up approach holds potential to address all the applications previously mentioned but its entitlement extends into new applications with much more ground-breaking potential. One such bottom-up application is the distributed x-ray source platform. In the medical space, using an array of microscale x-ray sources instead of a single source promises significant reductions in patient dose as well as smaller feature detectability and fewer image artifacts. Cold cathode field emitters are ideal for this application because they can be gated electrostatically or via photonic excitation, they do not generate excessive heat like other common electron emitters, they have higher brightness and they are relatively compact. This document describes how ZnO nanowire field emitter arrays are well suited for distributed x-ray source applications because they hold promise in each of the following critical areas: emission stability, simple scalable fabrication, performance, radiation resistance and photonic coupling.

  5. Transverse emittance dilution due to coupler kicks in linear accelerators

    Directory of Open Access Journals (Sweden)

    Brandon Buckley

    2007-11-01

    Full Text Available One of the main concerns in the design of low emittance linear accelerators (linacs is the preservation of beam emittance. Here we discuss one possible source of emittance dilution, the coupler kick, due to transverse electromagnetic fields in the accelerating cavities of the linac caused by the power coupler geometry. In addition to emittance growth, the coupler kick also produces orbit distortions. It is common wisdom that emittance growth from coupler kicks can be strongly reduced by using two couplers per cavity mounted opposite each other or by having the couplers of successive cavities alternate from above to below the beam pipe so as to cancel each individual kick. While this is correct, including two couplers per cavity or alternating the coupler location requires large technical changes and increased cost for superconducting cryomodules where cryogenic pipes are arranged parallel to a string of several cavities. We therefore analyze consequences of alternate coupler placements. We show here that alternating the coupler location from above to below compensates the emittance growth as well as the orbit distortions. For sufficiently large Q values, alternating the coupler location from before to after the cavity leads to a cancellation of the orbit distortion but not of the emittance growth, whereas alternating the coupler location from before and above to behind and below the cavity cancels the emittance growth but not the orbit distortion. We show that cancellations hold for sufficiently large Q values. These compensations hold even when each cavity is individually detuned, e.g., by microphonics. Another effective method for reducing coupler kicks that is studied is the optimization of the phase of the coupler kick so as to minimize the effects on emittance from each coupler. This technique is independent of the coupler geometry but relies on operating on crest. A final technique studied is symmetrization of the cavity geometry in the

  6. Study of Abnormal Vertical Emittance Growth in ATF Extraction Line

    Energy Technology Data Exchange (ETDEWEB)

    Alabau, M.; Faus-Golfe, A.; /Valencia U., IFIC; Alabau, M.; Bambade, P.; Brossard, J.; Le Meur, G.; Rimbault, C.; Touze, F.; /Orsay, LAL; Angal-Kalinin, D.; Jones, J.K.; /Daresbury; Appleby, R.; Scarfe, A.; /Manchester U.; Kuroda, S.; /KEK, Tsukuba; White, G.R.; Woodley, M.; /SLAC; Zimmermann, F.; /CERN

    2011-11-04

    Since several years, the vertical beam emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, that will transport the electron beam from the ATF Damping Ring (DR) to the future ATF2 Final Focus beam line, is significantly larger than the emittance measured in the DR itself, and there are indications that it grows rapidly with increasing beam intensity. This longstanding problem has motivated studies of possible sources of this anomalous emittance growth. One possible contribution is non-linear magnetic fields in the extraction region experimented by the beam while passing off-axis through magnets of the DR during the extraction process. In this paper, simulations of the emittance growth are presented and compared to observations. These simulations include the effects of predicted non-linear field errors in the shared DR magnets and orbit displacements from the reference orbit in the extraction region. Results of recent measurements using closed orbit bumps to probe the relation between the extraction trajectory and the anomalous emittance growth are also presented.

  7. MONOBLOCK EMITTERS FOR MELTING OF SYNTHETIC FATTY ACIDS

    Directory of Open Access Journals (Sweden)

    A. N. Cherepanov

    2014-03-01

    Full Text Available The paper deals with usage of monoblock emitters for melting of synthetic fatty acids, which are delivered to plants in a solid state and are used in the production of detergents as liquids. In such emitters all lamps are arranged in a common case. Irradiation of the solid phase in the direction of the channel melting axis is done through an output quartz window. This method excludes the possibility of slowing down or stopping the process when one of the tubes is overheated. Halogen lamps are used as light sources, each one is placed in individual transparent body. Combined effect of thermal power supply and the light emission should provide a significant increase in the rate of the channel melting in the solid phase of the synthetic fatty acid. The results of evaluations for achievable rates of the channel melting in the solid phase of the synthetic fatty acids are presented. Melting of the channel with one meter depth can be reached in less than an hour when eight halogen lamps of 100 W power are used. To exclude the possibility of self-ignition of the liquid phase of synthetic fatty acid it is proposed to adjust the luminosity of the emitter and the surface temperature by selecting the number of lamps in the monoblock emitter cavity. The usage of cylindrical quartz tube as a case for monoblock emitter increases the diameter of the melting channel due to side effects of light on the solid and liquid phases.

  8. Transverse emittance growth in staged laser-wakefield acceleration

    Directory of Open Access Journals (Sweden)

    T. Mehrling

    2012-11-01

    Full Text Available We present a study on the emittance evolution of electron bunches, externally injected into laser-driven plasma waves using the three-dimensional particle-in-cell (PIC code OSIRIS. Results show order-of-magnitude transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This behavior is supported by analytic theory reproducing the simulation data to a percent level. The length over which the full emittance growth develops is found to be less than or comparable to the typical dimension of a single plasma module in current multistage designs. In addition, the analytic theory enables the quantitative prediction of emittance degradation in two consecutive accelerators coupled by free-drift sections, excluding this as a scheme for effective emittance-growth suppression, and thus suggests the necessity of beam-matching sections between acceleration stages with fundamental implications on the overall design of staged laser-wakefield accelerators.

  9. Beam Delivery System Dogleg Design and Integration for the International Linear Collider

    CERN Document Server

    Jones, J

    2010-01-01

    It is proposed to investigate the option of moving the positron source to the end of the main linac as a part of the central integration in the International Linear Collider(ILC) project. The positron source incorporates an undulator at the end of the main linac and the photons generated in the undulator are transported to the target, located at a distance of around 400 m. The dogleg design has been optimised to provide the required transverse offset at the location of the target and to give minimum emittance growth at 500 GeV. The design of the dogleg, the layout changes and the tolerances on beam tuning as a result of locating this dogleg in the beginning of the beam delivery system (BDS) are presented.

  10. Quantum interference between two single photons emitted by independently trapped atoms

    CERN Document Server

    Beugnon, J; Dingjan, J; Darquié, B; Messin, G; Browaeys, A; Grangier, P; Beugnon, Jerome; Jones, Matthew; Dingjan, Jos; Darqui\\'{e}, Benoit; Messin, Gaetan; Browaeys, Antoine; Grangier, Philippe

    2006-01-01

    When two indistinguishable single photons are fed into the two input ports of a beam splitter, the photons will coalesce and leave together from the same output port. This is a quantum interference effect, which occurs because the two possible paths where the photons leave in different output ports interfere destructively. This effect was first observed in parametric downconversion by Hong, Ou and Mandel, and then with single photons produced one after the other by the same quantum emitter. With the recent development of quantum information, a lot of attention has been devoted to this coalescence effect as a resource for quantum data processing using linear optics techniques. To ensure the scalability of schemes based on these ideas, it is crucial that indistinguishable photons are emitted by a collection of synchronized, but otherwise independent sources. In this paper, we demonstrate the quantum interference of two single photons emitted by two independently trapped single atoms, bridging the gap towards th...

  11. Nanometer resolution imaging and tracking of fluorescent molecules with minimal photon fluxes

    CERN Document Server

    Balzarotti, Francisco; Gwosch, Klaus C; Gynnå, Arvid H; Westphal, Volker; Stefani, Fernando D; Elf, Johan; Hell, Stefan W

    2016-01-01

    We introduce MINFLUX, a concept for localizing photon emitters in space. By probing the emitter with a local intensity minimum of excitation light, MINFLUX minimizes the fluorescence photons needed for high localization precision. A 22-fold reduction of photon detections over that required in popular centroid-localization is demonstrated. In superresolution microscopy, MINFLUX attained ~1 nm precision, resolving molecules only 6 nm apart. Tracking single fluorescent proteins by MINFLUX increased the temporal resolution and the localizations per trace by 100-fold, as demonstrated with diffusing 30S ribosomal subunits in living E. coli. Since conceptual limits have not been reached, we expect this localization modality to break new ground for observing the dynamics, distribution, and structure of macromolecules in living cells and beyond.

  12. Cooperative behavior of quantum dipole emitters coupled to a zero-index nanoscale waveguide

    CERN Document Server

    Sokhoyan, Ruzan

    2015-01-01

    We study cooperative behavior of quantum dipole emitters coupled to a rectangular waveguide with dielectric core and silver cladding. We investigate cooperative emission and inter-emitter entanglement generation phenomena for emitters whose resonant frequencies are near the frequency cutoff of the waveguide, where the waveguide effectively behaves as zero-index metamaterial. We show that coupling emitters to a zero-index waveguide allows one to relax the constraint on precision positioning of emitters for observing inter-emitter entanglement generation and extend the spatial scale at which the superradiance can be observed.

  13. Clustering and lifetime of Lyman Alpha Emitters in the Epoch of Reionization

    CERN Document Server

    Hutter, Anne; Müller, Volker

    2015-01-01

    We calculate Lyman Alpha Emitter (LAE) angular correlation functions (ACFs) at $z\\simeq6.6$ and the fraction of lifetime (for the 100 Myrs preceding $z\\simeq6.6$) galaxies spend as Lyman Break Galaxies (LBGs) with/without Lyman Alpha (Ly\\alpha) emission using a model that combines SPH cosmological simulations (GADGET-2), dust attenuation and a radiative transfer code (pCRASH). The ACFs are a powerful tool that significantly narrows the 3D parameter space allowed by LAE Ly$\\alpha$ and UV luminosity functions (LFs) alone. With this work, we simultaneously constrain the escape fraction of ionizing photons $f_{esc}=0.05-0.5$, the mean fraction of neutral hydrogen in the intergalactic medium (IGM) $\\leq 0.01$ and the dust-dependent ratio of the escape fractions of Ly$\\alpha$ and UV continuum photons $f_\\alpha/f_c=0.6-1.2$. Our results show that reionization has the largest impact on the amplitude of the ACFs, and its imprints are clearly distinguishable from those of $f_{esc}$ and $f_\\alpha/f_c$. We also show that...

  14. Were progenitors of local L* galaxies Lyman-alpha emitters at high redshift?

    CERN Document Server

    Yajima, Hidenobu; Zhu, Qirong; Abel, Tom; Gronwall, Caryl; Ciardullo, Robin

    2011-01-01

    The Lya emission has been observed from galaxies over a redshift span z ~ 0 - 8.6. However, the link between high-redshift Lya emitters (LAEs) and local galaxies is largely unknown. Here, we investigate the Lya properties of progenitors of a local L^{*} galaxy by combining cosmological hydrodynamic simulations with three-dimensional radiative transfer calculations using the new ART^2 code. We find that the modeled galaxies are Lya bright in redshift z= 0 - 10. In particular, the Lya luminosities of some massive progenitors at z ~ 2 - 6 are close to the observed characteristic L_{Lya}^{*} of LAEs in that redshift range. Both Lya photon escape fraction and line equivalent width increase with redshift. The Lya escape fraction correlates with a number of physical properties of the galaxy, such as mass, SFR and metallicity. We find a "viewing-angle scatter" in which the photon escape depends strongly on the galaxy morphology and orientation. Moreover, we find that high-redshift LAEs show blue-shifted Lya line prof...

  15. Pro jected Shell Mo del Description for the Proton Emitters

    Institute of Scientific and Technical Information of China (English)

    卞宝安

    2016-01-01

    Proton radioactivity is an important decay mode for nuclei near the proton drip-line. Studies of this decay mode can reveal valuable information on exotic nuclear structure and provide important information on the stucture of nuclei in extreme conditions. The new experimental data can let us understand the interactions in exotic systems, which motivate further theoretical development. The most recent application of the projected shell model (PSM) for proton emitters is represented. We study the rotational bands of the deformed proton emitter 141Ho by using the PSM. The experimental data are well reproduced. Strongly suppressed γ transition from the low-lying Iπ= 3/2+ state makes this state isomeric. Variations in the dynamical moment of inertia are discussed due to band crossings using the band diagram. The calculated results for proton emitter 151Lu shows it is oblately deformed.

  16. Cooperative Lamb shift in a quantum emitter array

    CERN Document Server

    Meir, Ziv; Shahmoon, Ephraim; Oron, Dan; Ozeri, Roee

    2013-01-01

    Whenever several quantum light emitters are brought in proximity with one another, their interaction with common electromagnetic fields couples them, giving rise to cooperative shifts in their resonance frequency. Such collective line shifts are central to modern atomic physics, being closely related to superradiance on one hand and the Lamb shift on the other. Although collective shifts have been theoretically predicted more than fifty years ago, the effect has not been observed yet in a controllable system of a few isolated emitters. Here, we report a direct spectroscopic observation of the cooperative shift of an optical electric dipole transition in a system of up to eight Sr ions suspended in a Paul trap. We study collective resonance shift in the previously unexplored regime of far-field coupling, and provide the first observation of cooperative effects in an array of quantum emitters. These results pave the way towards experimental exploration of cooperative emission phenomena in mesoscopic systems.

  17. Emittance growth in the DARHT Axis-II Downstream Transport

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Jr., Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schulze, Martin E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-14

    Using a particle-in-cell (PIC) code, we investigated the possibilities for emittance growth through the quadrupole magnets of the system used to transport the high-current electron beam from an induction accelerator to the bremsstrahlung converter target used for flash radiography. We found that even highly mismatched beams exhibited little emittance growth (< 6%), which we attribute to softening of their initial hard edge current distributions. We also used this PIC code to evaluate the accuracy of emittance measurements using a solenoid focal scan following the quadrupole magnets. If the beam is round after the solenoids, the simulations indicate that the measurement is highly accurate, but it is substantially inaccurate for elliptical beams

  18. DC-SC Photoinjector with Low Emittance at Peking University

    CERN Document Server

    Xiang Rong; Hao, J; Huang, Senlin; Lu Xiang Yang; Quan, Shengwen; Zhang, Baocheng; Zhao, Kui

    2005-01-01

    High average power Free Electron Lasers require the high quality electron beams with the low emittance and the sub-picosecond bunches. The design of DC-SC photoinjector, directly combining a DC photoinjector with an SRF cavity, can produce high average current beam with moderate bunch charge and high duty factor. Because of the DC gun, the emittance increases quickly at the beginning, so a carefully design is needed to control that. In this paper, the simulation of an upgraded design has been done to lower the normalized emittance below 1.5mm·mrad. The photoinjector consists of a DC gap and a 2+1/2-cell SRF cavity, and it is designed to produce 4.2 MeV electron beams at 100pC bunch charge and 81.25MHz repetition rate (8 mA average current).

  19. Field Emission from Lateral Multiwalled Carbon Nanotube Yarn Emitters

    Directory of Open Access Journals (Sweden)

    Guohai Chen

    2016-10-01

    Full Text Available A field emission from a lateral emitter made by a multiwalled carbon nanotube (MWCNT yarn was investigated. The lateral emitter showed an excellent field emission performance with a low turn-on electric field of 1.13 V/um at an emission current of 1 uA, high emission current of 0.2 mA at an applied voltage of 700 V, and long-time emission stability for over 20 h without any significant current decay under an initial emission current of about 0.10 mA. The lateral emitter also demonstrated a uniform line emission pattern. It is suggested that the field emission occurs from the outmost MWCNTs which are protruding out from the yarn surface.

  20. Field Emission from Lateral Multiwalled Carbon Nanotube Yarn Emitters

    Science.gov (United States)

    Chen, Guohai; Song, Yenan

    2016-10-01

    A field emission from a lateral emitter made by a multiwalled carbon nanotube (MWCNT) yarn was investigated. The lateral emitter showed an excellent field emission performance with a low turn-on electric field of 1.13 V/um at an emission current of 1 uA, high emission current of 0.2 mA at an applied voltage of 700 V, and long-time emission stability for over 20 h without any significant current decay under an initial emission current of about 0.10 mA. The lateral emitter also demonstrated a uniform line emission pattern. It is suggested that the field emission occurs from the outmost MWCNTs which are protruding out from the yarn surface.

  1. Emittance measurements for the Illinois/CEBAF polarized electron source

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, B.M.; Cardman, L.S. [Illinois Univ., Urbana, IL (United States); Sinclair, C.K. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

    1995-01-01

    The transverse thermal properties of the electrons photoemitted from GaAs determine the intrinsic beam emittance, an important quantity in applications such as polarized electron sources and high-brightness sources. In this paper, emittance measurements using the Illinois/CEBAF polarized electron source are described. The emittance was measured as a function of both the laser beam spot size and laser wavelength at low currents. The data was used to infer the transverse thermal energy of the electrons photoemitted from GaAs for wavelengths between 514 and 840 nm. Near the bandgap the transverse energy is {approximately}34 meV, a factor of 3 lower than that of the beam from a typical thermionic electron gun. 8 refs., 2 figs.

  2. On the measurement of positron emitters with Ge detectors

    Energy Technology Data Exchange (ETDEWEB)

    Peyres, Virginia, E-mail: virginia.peyres@ciemat.e [Ciemat, Laboratorio de Metrologia de Radiaciones Ionizantes, Avda. Complutense 22, Madrid 28040 (Spain); Garcia-Torano, Eduardo [Ciemat, Laboratorio de Metrologia de Radiaciones Ionizantes, Avda. Complutense 22, Madrid 28040 (Spain)

    2011-05-01

    This paper discusses the problems related to the measurement of positron emitters with germanium detectors. Five positron emitters with important applications in nuclear medicine ({sup 22}Na, {sup 18}F, {sup 11}C, {sup 13}N and {sup 68}Ga) have been studied. Measurements and Monte Carlo simulations have been used to determine the optimal conditions of measurement in gamma-ray spectrometry systems. The results obtained indicate that adding adequate absorbers, detection efficiencies are close to those of gamma emitters of similar energy measured in the same conditions, which allows a rapid calibration of a Ge-based spectrometry system. More accurate results are also presented using a detailed Monte Carlo simulation. Comparison to experimental data shows a good agreement.

  3. High efficiency and stable white OLED using a single emitter

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian [Arizona State Univ., Tempe, AZ (United States). School of Mechanical, Aerospace, Chemical and Materials Engineering

    2016-01-18

    The ultimate objective of this project was to demonstrate an efficient and stable white OLED using a single emitter on a planar glass substrate. The focus of the project is on the development of efficient and stable square planar phosphorescent emitters and evaluation of such class of materials in the device settings. Key challenges included improving the emission efficiency of molecular dopants and excimers, controlling emission color of emitters and their excimers, and improving optical and electrical stability of emissive dopants. At the end of this research program, the PI has made enough progress to demonstrate the potential of excimer-based white OLED as a cost-effective solution for WOLED panel in the solid state lighting applications.

  4. Laser Process for Selective Emitter Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    G. Poulain

    2012-01-01

    Full Text Available Selective emitter solar cells can provide a significant increase in conversion efficiency. However current approaches need many technological steps and alignment procedures. This paper reports on a preliminary attempt to reduce the number of processing steps and therefore the cost of selective emitter cells. In the developed procedure, a phosphorous glass covered with silicon nitride acts as the doping source. A laser is used to open locally the antireflection coating and at the same time achieve local phosphorus diffusion. In this process the standard chemical etching of the phosphorous glass is avoided. Sheet resistance variation from 100 Ω/sq to 40 Ω/sq is demonstrated with a nanosecond UV laser. Numerical simulation of the laser-matter interaction is discussed to understand the dopant diffusion efficiency. Preliminary solar cells results show a 0.5% improvement compared with a homogeneous emitter structure.

  5. The role of phonon scattering in the indistinguishability of photons emitted from semiconductor cavity QED systems

    DEFF Research Database (Denmark)

    Nielsen, Per Kær; Gregersen, Niels; Mørk, Jesper

    2013-01-01

    A solid-state single-photon source emitting indistinguishable photons on-demand is an essential component of linear optics quantum computing schemes. However, the emitter will inevitably interact with the solid-state environment causing decoherence and loss of indistinguishability. In this paper......, we present a comprehensive theoretical treatment of the influence of phonon scattering on the coherence properties of single photons emitted from semiconductor quantum dots. We model decoherence using a full microscopic theory and compare with standard Markovian approximations employing Lindblad...

  6. Single photon superradiance and cooperative Lamb shift in an optoelectronic device

    CERN Document Server

    Frucci, Giulia; Vasanelli, Angela; Dailly, Baptiste; Todorov, Yanko; Sirtori, Carlo; Beaudoin, Grégoire; Sagnes, Isabelle

    2016-01-01

    Single photon superradiance is a strong enhancement of spontaneous emission appearing when a single excitation is shared between a large number of two-level systems. This enhanced rate can be accompanied by a shift of the emission frequency, the cooperative Lamb shift, issued from the exchange of virtual photons between the emitters. In this work we present a semiconductor optoelectronic device allowing the observation of these two phenomena at room temperature. We demonstrate experimentally and theoretically that plasma oscillations in spatially separated quantum wells interact through real and virtual photon exchange. This gives rise to a superradiant mode displaying a large cooperative Lamb shift.

  7. Observation of negative differential transconductance in tunneling emitter bipolar transistors

    Science.gov (United States)

    van Veenhuizen, Marc J.; Locatelli, Nicolas; Moodera, Jagadeesh; Chang, Joonyeon

    2009-08-01

    We report on measurement of negative differential transconductance (NDTC) of iron (Fe)/magnesium-oxide (MgO)/silicon tunneling emitter NPN bipolar transistors. Device simulations reveal that the NDTC is a consequence of an inversion layer at the tunneling-oxide/P-silicon interface for low base voltages. Electrons travel laterally through the inversion layer into the base and give rise to an increase in collector current. The NDTC results from the recombination of those electrons at the interface between emitter and base contact which is dependent on the base voltage. For larger base voltages, the inversion layer disappears marking the onset of normal bipolar transistor behavior.

  8. Emittance Measurements at the Langley Chemical Physics Laboratory

    Science.gov (United States)

    Lewis, B. W.

    1960-01-01

    Total hemispherical emittance measurements are made routinely for materials which may be heated by electrical resistance methods over the temperature range of 600 degrees to 2,000 F by using a black-body reference method. This employs a conical black body and a thermopile detector with a calcium fluoride lens. Emittance is obtained by measuring the radiant flux from the specimen strip and comparing it with the flux from an equal area of the black-body cone at the same temperature. The temperature measurements are made by use of thermocouples. It is planned to extend the temperature range of this type of measurement to temperatures above 2,000 F. Another technique has been investigated for measuring emittance of materials not amenable to electrical heating or thermocouple attachment. This method uses a black-body-cavity furnace similar to that used in reference 5 to measure emittance of transparent materials such as glass. The method employs a heated black-body cavity in which the semicircular specimen is allowed to come to the equilibrium temperature of the cavity and then is rotated in front of a water-cooled viewing port where a sensitive thermistor detector alternately views the specimen surface and the black-body cavity. The ratio of the two readings gives the specimen emittance directly, for the temperature of the black body. The detector output is recorded on a fast Brown self-balancing potentiometer. The furnace is provided with a water-cooled blackened shutter which may be inserted behind the specimen to eliminate any transmitted black-body radiation if the specimen is transparent. This apparatus is capable of measuring total normal emittance over the temperature range of 1,000 degrees to 2,000 F. Preliminary data for boron nitride specimens of two thicknesses are shown where total normal emittance is plotted against temperature for two experimental conditions: (1) black-body radiation incident on the back of the specimen and (2) no black-body radiation

  9. Beam emittance reduction during operation of Indus-2

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Ali Akbar, E-mail: fakhri@rrcat.gov.in; Kant, Pradeep; Ghodke, A. D.; Singh, Gurnam [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2015-11-15

    Indus-2 storage ring is a 2.5 GeV third generation synchrotron radiation source. This source was commissioned using a moderate optics. Beam injection was accomplished using an off momentum electron beam to avoid difficulties faced in storage of beam at 550 MeV. The injection procedure and relevant beam dynamical studies are discussed. The switch over from the moderate optics to low emittance optics is done at 2.5 GeV after storing the electron beam. The procedure evolved to reduce the beam emittance and its implementation during the operation is discussed.

  10. Spectrum of classes of point emitters of electromagnetic wave fields.

    Science.gov (United States)

    Castañeda, Román

    2016-09-01

    The spectrum of classes of point emitters has been introduced as a numerical tool suitable for the design, analysis, and synthesis of non-paraxial optical fields in arbitrary states of spatial coherence. In this paper, the polarization state of planar electromagnetic wave fields is included in the spectrum of classes, thus increasing its modeling capabilities. In this context, optical processing is realized as a filtering on the spectrum of classes of point emitters, performed by the complex degree of spatial coherence and the two-point correlation of polarization, which could be implemented dynamically by using programmable optical devices.

  11. Carbon Nanotube Electron Emitter for X-ray Imaging

    Directory of Open Access Journals (Sweden)

    Jung Su Kang

    2012-11-01

    Full Text Available The carbon nanotube field emitter array was grown on silicon substrate through a resist-assisted patterning (RAP process. The shape of the carbon nanotube array is elliptical with 2.0 × 0.5 mm2 for an isotropic focal spot size at anode target. The field emission properties with triode electrodes show a gate turn-on field of 3 V/µm at an anode emission current of 0.1 mA. The author demonstrated the X-ray source with triode electrode structure utilizing the carbon nanotube emitter, and the transmitted X-ray image was of high resolution.

  12. Epitaxial Growth of Germanium on Silicon for Light Emitters

    Directory of Open Access Journals (Sweden)

    Chengzhao Chen

    2012-01-01

    Full Text Available This paper describes the role of Ge as an enabler for light emitters on a Si platform. In spite of the large lattice mismatch of ~4.2% between Ge and Si, high-quality Ge layers can be epitaxially grown on Si by ultrahigh-vacuum chemical vapor deposition. Applications of the Ge layers to near-infrared light emitters with various structures are reviewed, including the tensile-strained Ge epilayer, the Ge epilayer with a delta-doping SiGe layer, and the Ge/SiGe multiple quantum wells on Si. The fundamentals of photoluminescence physics in the different Ge structures are discussed briefly.

  13. Recent progress of carbon nanotube field emitters and their application.

    Science.gov (United States)

    Seelaboyina, Raghunandan; Choi, Wonbong

    2007-01-01

    The potential of utilizing carbon nanotube field emission properties is an attractive feature for future vacuum electronic devices including: high power microwave, miniature x-ray, backlight for liquid crystal displays and flat panel displays. Their high emission current, nano scale geometry, chemical inertness and low threshold voltage for emission are attractive features for the field emission applications. In this paper we review the recent developments of carbon nanotube field emitters and their device applications. We also discuss the latest results on field emission current amplification achieved with an electron multiplier microchannel plate, and emission performance of multistage field emitter based on oxide nanowire operated in poor vacuum.

  14. Ultra-low emittance X-band photocathode RF gun

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LIU Xiao-Han

    2009-01-01

    In this paper,we present the simulation results of a 1.6 cell X-band photocathode RF gun for ultra-low emittance electron beams.It will work at 9.3 GHz.The emittance,bunch length,electron energy and energy spread at the gun exit are optimized at bunch charge of 1pC using PARMELA.Electron bunches type coupler is adopted in this gun and an initial simulation by MAFIA is also given in this paper.

  15. Ultra-Sensitivity Glucose Sensor Based on Field Emitters

    Directory of Open Access Journals (Sweden)

    Song Yinglin

    2009-01-01

    Full Text Available Abstract A new glucose sensor based on field emitter of ZnO nanorod arrays (ZNA was fabricated. This new type of ZNA field emitter-based sensor shows high sensitivity with experimental limit of detection of 1 nM glucose solution and a detection range from 1 nM to 50 μM in air at room temperature, which is lower than that of glucose sensors based on surface plasmon resonance spectroscopy, fluorescence signal transmission, and electrochemical signal transduction. The new glucose sensor provides a key technique for promising consuming application in biological system for detecting low levels of glucose on single cells or bacterial cultures.

  16. Coherent polarization locking of a diode emitter array.

    Science.gov (United States)

    Ng, S P; Phua, P B

    2009-07-01

    We present our work on the coherent combining of an array of diode emitters in a conventional diode bar configuration using the coherent polarization locking technique. An external laser cavity is designed so that the diode emissions from four diode emitters are spatially overlapped and passively phase locked via a series of birefringent walk-off crystals and a polarizing beam splitter. This concept was experimentally demonstrated up to 1030 mW of coherently combined power and was shown to increase the laser brightness of the diode bar by approximately 50 times.

  17. Thermal emittance and response time of a cesium antimonide photocathode

    Science.gov (United States)

    Cultrera, Luca; Bazarov, Ivan; Bartnik, Adam; Dunham, Bruce; Karkare, Siddharth; Merluzzi, Richard; Nichols, Matthew

    2011-10-01

    Measurements of the intrinsic emittance and response time of a Cs3Sb photocathode are presented. The emittance is obtained with a solenoid scan technique using a high voltage dc photoemission gun. Photoemission response time is evaluated using a RF deflecting cavity synchronized to a picosecond laser pulse train. We find that Cs3Sb has both small mean transverse energy, 160 ± 10 meV at 532 nm laser wavelength, and a prompt response time (below the resolution of our measurement) making it a suitable material for high brightness electron photoinjectors.

  18. Emittances Studies at the Fermilab/NICADD Photoinjector Laboratory

    CERN Document Server

    Tikhoplav, Rodion; Melissinos, A C; Regis-Guy Piot, Philippe

    2005-01-01

    The Fermilab/NICADD photoinjector incorporates an L-band rf-gun capable of generating 1-10 nC bunches. The bunches are then accelerated to 16 MeV with a TESLA superconducting cavity. In the present paper we present parametric studies of transverse emittances and energy spread for a various operating points of the electron source (RF-gun E-field, laser length and spot size, and solenoid settings). We especially study the impact, on transverse emittance, of Gaussian and Plateau temporal distribution of the photocathode drive-laser.

  19. Efficient Terahertz Photoconductive Emitters with Improved Electrode Structures

    Institute of Scientific and Technical Information of China (English)

    Ying-Xin Wang; Yi-Jie Niu; Wei Cheng; Zhi-Qiang Li; Zi-Ran Zhao

    2014-01-01

    We present the design, fabrication, and characterization of two new types of terahertz photoconductive emitters. One has an asymmetric four-contact electrode structure and the other has an arc-shaped electrode structure, which are all modified from a traditional strip line antenna. Numerical simulations and real experiments confirm the good performance of the proposed antennas. An amplitude increase of about 40% is experimentally observed for the terahertz signals generated from the new structures. The special electrode structure and its induced local bias field enhancement are responsible for this radiation efficiency improvement. Our work demonstrates the feasibility of developing highly efficient terahertz photoconductive emitters by optimizing the electrode structure.

  20. Tuning the Photon Statistics of a Strongly Coupled Nanophotonic System

    CERN Document Server

    Dory, Constantin; Müller, Kai; Lagoudakis, Konstantinos G; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L; Kelaita, Yousif; Sapra, Neil V; Vučković, Jelena

    2016-01-01

    We investigate the dynamics of single- and multi-photon emission from detuned strongly coupled systems based on the quantum-dot-photonic-crystal resonator platform. Transmitting light through such systems can generate a range of non-classical states of light with tunable photon counting statistics due to the nonlinear ladder of hybridized light-matter states. By controlling the detuning between emitter and resonator, the transmission can be tuned to strongly enhance either single- or two-photon emission processes. Despite the strongly-dissipative nature of these systems, we find that by utilizing a self-homodyne interference technique combined with frequency-filtering we are able to find a strong two-photon component of the emission in the multi-photon regime. In order to explain our correlation measurements, we propose rate equation models that capture the dominant processes of emission both in the single- and multi-photon regimes. These models are then supported by quantum-optical simulations that fully cap...