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Sample records for tw laser system

  1. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Science.gov (United States)

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

    2009-06-01

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

  2. TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Institute of Scientific and Technical Information of China (English)

    YAN Li-Xin; DU Ying-Chao; DU Qiang; LI Ren-Kai; HUA Jian-Fei; HUANG Wen-Hui; TANG Chuan-Xiang

    2009-01-01

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

  3. Numerical simulations of recent proton acceleration experiments with sub-100 TW laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Sinigardi, Stefano, E-mail: sinigardi@bo.infn.it

    2016-09-01

    Recent experiments carried out at the Italian National Research Center, National Optics Institute Department in Pisa, are showing interesting results regarding maximum proton energies achievable with sub-100 TW laser systems. While laser systems are being continuously upgraded in laboratories around the world, at the same time a new trend on stabilizing and making ion acceleration results reproducible is growing in importance. Almost all applications require a beam with fixed performance, so that the energy spectrum and the total charge exhibit moderate shot to shot variations. This result is surely far from being achieved, but many paths are being explored in order to reach it. Some of the reasons for this variability come from fluctuations in laser intensity and focusing, due to optics instability. Other variation sources come from small differences in the target structure. The target structure can vary substantially, when it is impacted by the main pulse, due to the prepulse duration and intensity, the shape of the main pulse and the total energy deposited. In order to qualitatively describe the prepulse effect, we will present a two dimensional parametric scan of its relevant parameters. A single case is also analyzed with a full three dimensional simulation, obtaining reasonable agreement between the numerical and the experimental energy spectrum.

  4. Route to 100 TW Ti: Sapphire laser at repetitive mode

    Directory of Open Access Journals (Sweden)

    Teng Hao

    2013-11-01

    Full Text Available We demonstrated a 100 TW-class femtosecond Ti: sapphire laser running at repetition rate of 0.1 Hz by adding a stage amplifier in the 20 TW/10 Hz laser facility (XL-II. Pumping the new stage amplifier with the 25 J green Nd:glass laser, we successfully upgraded the laser energy to 3.4 J with duration of 29 fs, corresponding to a peak power of 117 TW.

  5. Proton acceleration with a table-top TW laser

    Science.gov (United States)

    Seimetz, M.; Bellido, P.; Lera, R.; Ruiz-de la Cruz, A.; Mur, P.; Sánchez, I.; Galán, M.; Sánchez, F.; Roso, L.; Benlloch, J. M.

    2016-11-01

    We report on the recent demonstration of proton acceleration from a purpose-made Ti:Sapphire laser system. In the first successful series of autumn 2015, running at 2 TW peak power and 100 Hz diode pump rate, protons up to 0.7 MeV have been spectrally characterised. Subsequently, at increased laser pulse energy and improved contrast, we have obtained maximum particle energies around 1.7 MeV. These results, achieved in single-shot mode with a variety of thin foil targets, are an important step towards our aim of a stable, compact proton accelerator with high rate capacity.

  6. Phase contrast imaging using Betatron x-ray beams produced by a 100 TW high intensity laser system

    Science.gov (United States)

    Fourmaux, Sylvain; Corde, Sebastien; Ta Phuoc, Kim; Lassonde, Philippe; Martin, Francois; Malka, Victor; Rousse, Antoine; Kieffer, Jean

    2011-10-01

    Development of x-ray phase contrast imaging applications with a laboratory scale source have been limited by the long exposure time needed to obtain one image. We demonstrate, using the Betatron x-ray radiation produced when electrons are accelerated and wiggled in the laser-wakefield cavity, the potential of Betatron x-ray radiation for femtosecond phase contrast imaging. We characterize the x-ray source using a knife edge technique and nylon wires for calibration. We then show that high-quality phase contrast images of complex objects located in air, can be obtained with only a single laser shot. The Betatron x-ray source used in this demonstration experiment has a source diameter of 1.7 microns and produces a synchrotron spectrum with critical energy Ec = 12 . 3 + / - 2 . 5 keV and 109 photons per shot in the whole spectrum.

  7. Performance tests of the 5 TW, 1 kHz, passively CEP-stabilized ELI-ALPS SYLOS few-cycle laser system (Conference Presentation)

    Science.gov (United States)

    Stanislauskas, Tomas; Budriūnas, Rimantas; Veitas, Gediminas; Gadonas, Darius; Adamonis, Jonas; Aleknavičius, Aidas; Masian, Gžegož; Kuprionis, Zenonas; Hoff, Dominik; Paulus, Gerhard G.; Börzsönyi, Ádám.; Toth, Szabolcs; Kovacs, Mate; Csontos, János; López-Martens, Rodrigo; Osvay, Károly

    2017-05-01

    ELI-ALPS in Hungary, one of the three pillars of the Extreme Light Infrastructure, aims at providing diverse light sources, including energetic attosecond pulses at the highest possible repetition rates. One of the main laser systems for driving plasma and gas-based HHG stages, is a state-of-the-art 1 kHz few-cycle laser called SYLOS. Targeted pulse parameters are an energy of 100 mJ and a duration shorter than two optical cycles (energy, phase and pointing stability as well as high spatiotemporal quality. The first phase of the laser system has already set a new standard in kHz laser system engineering and technology. The performance and reliability of the SYLOS laser have been consistently tested over the course of a six-month trial period. During this time the system was running at least 8 hours a day at full power for more than 5 months. The current output parameters are 5 TW peak power, 45 mJ pulse energy with 9 fs duration and 300 mrad CEP stability, while the spectrum spans over 300 nm around 840 nm central wavelength. The layout follows the general scheme NOPCPA architecture with a passively CEP-stabilized front-end. The pulses are negatively chirped for the amplification process and compressed by a combination of large aperture bulk glass blocks and positively chirped mirrors under vacuum conditions at the output. During the trial period, the laser system demonstrated outstanding reliability. Daily startup and shutdown procedures take only a few minutes, and the command-control system enables pulse parameters to be modified instantly. Controlling the delays of individual NOPCPA stages makes it possible to tailor the output spectrum of the pulses and tune the central wavelength between 770 nm and 940 nm. We performed several experimental tests to find out the pulse characteristics. Pulse duration was verified with Wizzler, chirp-scan, autocorrelation methods and a stereo-ATI independently. All of them confirmed the sub-9 fs pulse duration. We recorded the

  8. Simulation studies of laser wakefield acceleration based on typical 100 TW laser facilities

    Institute of Scientific and Technical Information of China (English)

    李大章; 高杰; 朱雄伟; 何安

    2011-01-01

    In this paper, 2-D Particle-In-Cell simulations are made for Laser Wakefield Accelerations (LWFA). As in a real experiment, we perform plasma density scanning for typical 100 TW laser facilities. Several basic laws for self-injected acceleration in a bubb

  9. Simulation studies of laser wakefield acceleration based on typical 100 TW laser facilities

    Institute of Scientific and Technical Information of China (English)

    LI Da-Zhang; GAO Jie; ZHU Xiong-Wei; HE An

    2011-01-01

    In this paper,2-D Particle-In-Cell simulations are made for Laser Wakefield Accelerations(LWFA).As in a real experiment,we perform plasma density scanning for typical 100 TW laser facilities.Several basic laws for self-injected acceleration in a bubble regime are presented.According to these laws,we choose a proper plasma density and then obtain a high quality quasi-monoenergetic electron bunch with arms energy of more than 650 MeV and a bunch length of less than 1.5 μn.

  10. First electrons from the new 220 TW Frascati Laser for Acceleration and Multidisciplinary Experiments (FLAME) at Frascati National Laboratories (LNF)

    Energy Technology Data Exchange (ETDEWEB)

    Levato, T., E-mail: tadzio.levato@lnf.infn.it [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Calvetti, M. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); University of Florence, Department of Physics (Italy); Anelli, F. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Batani, D.; Benocci, R. [University of Milano Bicocca, Department of Physics (Italy); Cacciotti, L. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Cecchetti, C.A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Cerafogli, O.; Chimenti, P.; Clozza, A. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Drenska, N. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Esposito, A. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Faccini, R. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Fioravanti, S. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); Gamucci, A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Gatti, C. [University of Roma La Sapienza (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Giulietti, A. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); Giulietti, D. [University of Pisa, Department of Physics (Italy); Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Labate, L. [Intense Laser Irradiation Lab. (ILIL), Istituto Nazionale di Ottica (INO) - CNR, Pisa (Italy); INFN, Sect. of Pisa (Italy); Laboratori Nazionali di Frascati (LNF), INFN (Italy); Lollo, V. [Laboratori Nazionali di Frascati (LNF), INFN (Italy); and others

    2013-08-21

    A new era of laser based plasma accelerators is emerging following the commissioning of many high power laser facilities around the world. Extremely short (tens of fs) laser pulses with energy of multi-joules level are available at these newly built facilities. Here we describe the new 220 TW FLAME facility. In particular we discuss the laser system general layout, the main measurements on the laser pulse parameters, the underground target area. Finally we give an overview of the first results of the Self-Injection Test Experiment (SITE), obtained at a low laser energy. This initial low laser energy experimental campaign was necessary for the validation of the radio-protection shielding (Esposito, 2011 [1]) we discuss here. With respect to our preliminary configuration, with a pulse duration of 30 fs and a focusing optic of F/15, we discuss here the minimum laser energy requirements for electron acceleration and the forward transmitted optical radiation.

  11. Kerr self-defocusing of multiple filaments in TW peak power UV laser beam

    Science.gov (United States)

    Zvorykin, V. D.; Goncharov, S. A.; Ionin, A. A.; Mokrousova, D. V.; Ryabchuk, S. V.; Seleznev, L. V.; Shutov, A. V.; Smetanin, I. V.; Sunchugasheva, E. S.; Ustinovskii, N. N.

    2016-12-01

    An effective suppression of multiple filamentation of the sub-TW peak power supercritical laser beam in xenon gas was demonstrated in direct amplification of subpicosecond UV pulses at Ti:sapphire/KrF laser facility GARPUN-MTW. A large negative nonlinear refractive index due to a two-photon resonance of KrF laser radiation with Xe 6p{{≤ft[1/2\\right]}0} state ensured Kerr self-defocusing of a few hundred filaments with a local peak intensity of ~0.2 TW cm-2, 200-fold higher than the average one over the beam cross section, and thus homogenized the laser beam. UV filaments in Xe produced a narrow-angle monochromatic coherent cone emission at 828 nm wavelength due to stimulated hyper-Raman scattering and amplified spontaneous emission at the transition 6p{{≤ft[1/2\\right]}0}\\to 6s≤ft[3/2\\right]10 .

  12. Development of x-ray and ion diagnostics of plasma obtained with a 10-TW femtosecond laser

    Science.gov (United States)

    Ryć, L.; Dobrzański, L.; Dubecky, F.; Jabłoński, S.; Parys, P.; Słysz, W.; Rosiński, M.

    2016-07-01

    Several x-ray and ion semiconductor detectors have been developed for the diagnostics of femtosecond laser plasma generated by a 10-TW laser which was recently commissioned for operation at the Institute of Plasma Physics and Laser Microfusion, Warsaw. A range of detectors has been employed including a CdTe detector for hard x-rays and four detectors for proton detection. These four are SiC and GaN employing a sandwich structure, an interdigitated M-S-M InP detector and finally a silicon photo-diode equipped with an aluminium filter (to shield against scattered light). The detectors presented are innovative as they are not commonly used for the diagnostic of laser plasma. The details of the internal structures of the detectors are presented. The immunity of the detectors to the noise coming from the laser system and the femtosecond plasma is discussed. Lastly, the possibility for further modifications and improvements are considered and discussed.

  13. D-D nuclear fusion processes induced in polyethylene foams by TW Laser-generated plasma

    Science.gov (United States)

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Ullschmied, J.

    2015-06-01

    Deuterium-Deuterium fusion processes were generated by focusing the 3 TW PALS Laser on solid deuterated polyethylene targets placed in vacuum. Deuterium ion acceleration of the order of 4 MeV was obtained using laser irradiance Iλ2 ˜ 5 × 1016 W μm2/cm2 on the target. Thin and thick targets, at low and high density, were irradiated and plasma properties were monitored "on line" and "off line". The ion emission from plasma was monitored with Thomson Parabola Spectrometer, track detectors and ion collectors. Fast semiconductor detectors based on SiC and fast plastic scintillators, both employed in time-of-flight configuration, have permitted to detect the characteristic 3.0 MeV protons and 2.45 MeV neutrons emission from the nuclear fusion reactions. From massive absorbent targets we have evaluated the neutron flux by varying from negligible values up to about 5 × 107 neutrons per laser shot in the case of foams targets, indicating a reaction rate of the order of 108 fusion events per laser shot using "advanced targets".

  14. D-D nuclear fusion processes induced in polyethylene foams by TW Laser-generated plasma

    Directory of Open Access Journals (Sweden)

    Torrisi L.

    2015-01-01

    Full Text Available Deuterium-Deuterium fusion processes were generated by focusing the 3 TW PALS Laser on solid deuterated polyethylene targets placed in vacuum. Deuterium ion acceleration of the order of 4 MeV was obtained using laser irradiance Iλ2 ∼ 5 × 1016 W μm2/cm2 on the target. Thin and thick targets, at low and high density, were irradiated and plasma properties were monitored “on line” and “off line”. The ion emission from plasma was monitored with Thomson Parabola Spectrometer, track detectors and ion collectors. Fast semiconductor detectors based on SiC and fast plastic scintillators, both employed in time-of-flight configuration, have permitted to detect the characteristic 3.0 MeV protons and 2.45 MeV neutrons emission from the nuclear fusion reactions. From massive absorbent targets we have evaluated the neutron flux by varying from negligible values up to about 5 × 107 neutrons per laser shot in the case of foams targets, indicating a reaction rate of the order of 108 fusion events per laser shot using “advanced targets”.

  15. Scaling laws for energetic ions from the commissioning of the new Los Alamos National Laboratory 200 TW Trident laser.

    Science.gov (United States)

    Flippo, K A; Workman, J; Gautier, D C; Letzring, S; Johnson, R P; Shimada, T

    2008-10-01

    The recent Los Alamos National Laboratory Trident laser enhanced from 30 to 200 TW in power allows more than 100 J to be delivered on target in 500 fs with a spot size smaller than 12 microm at full width at half maximum. 15 microm flat-foil targets have been observed to produce proton beams in excess of 50 MeV at an intensity of only approximately 4x10(19) W/cm(2) with efficiencies approaching 5%. The Trident laser beam characteristics are presented along with the data compared to published scaling laws for proton acceleration.

  16. Laser Driven Compression Equations of State and Hugoniot Pressure Measurements in Thick Solid Metallic Targets at ˜0.17-13 TW/cm2

    Science.gov (United States)

    Remo, John L.

    2010-10-01

    An electro-optic laser probe was developed to obtain parameters for high energy density equations of state (EoS), Hugoniot pressures (PH), and strain rates for high energy density laser irradiation intensity, I, experiments at ˜170 GW/cm2 (λ = 1064 nm) to ˜13 TW/cm2 (λ = 527 nm) on Al, Cu, Ti, Fe, Ni metal targets in a vacuum. At I ˜7 TW/cm2 front surface plasma pressures and temperatures reached 100's GPa and over two million K. Rear surface PH ranged from 7-120 GPa at average shock wave transit velocities 4.2-8.5 km/s, depending on target thickness and I. A surface plasma compression ˜100's GPa generated an impulsive radial expanding shock wave causing compression, rarefactions, and surface elastic and plastic deformations depending on I. A laser/fiber optic system measured rear surface shock wave emergence and particle velocity with ˜3 GHz resolution by monitoring light deflection from diamond polished rear surfaces of malleable metallic targets, analogous to an atomic force microscope. Target thickness, ˜0.5-2.9 mm, prevented front surface laser irradiation penetration, due to low radiation skin depth, from altering rear surface reflectivity (refractive index). At ˜10 TW electromagnetic plasma pulse noise generated from the target chamber overwhelmed detector signals. Pulse frequency analysis using Moebius loop antennae probed transient noise characteristics. Average shock (compression) and particle (rear surface displacement) velocity measurements determined rear surface PH and GPa) EoS that are compared with gas guns.

  17. 200 TW 45 fs laser based on optical parametric chirped pulse amplification.

    Science.gov (United States)

    Lozhkarev, V V; Freidman, G I; Ginzburg, V N; Katin, E V; Khazanov, E A; Kirsanov, A V; Luchinin, G A; Mal'shakov, A N; Martyanov, M A; Palashov, O V; Poteomkin, A K; Sergeev, A M; Shaykin, A A; Yakovlev, I V; Garanin, S G; Sukharev, S A; Rukavishnikov, N N; Charukhchev, A V; Gerke, R R; Yashin, V E

    2006-01-01

    200 TW peak power has been achieved experimentally using a Cr:forsterite master oscillator at 1250 nm, a stretcher, three optical parametrical amplifiers based on KD*P (DKDP) crystals providing 14.5 J energy in the chirped pulse at 910 nm central wavelength, and a vacuum compressor. The final parametrical amplifier and the compressor are described in detail. Scaling of such architecture to multipetawatt power is discussed.

  18. Generation of 25-TW Femtosecond Laser Pulses at 515 nm with Extremely High Temporal Contrast

    Directory of Open Access Journals (Sweden)

    Marco Hornung

    2015-12-01

    Full Text Available We report on the frequency doubling of femtosecond laser pulses at 1030 nm center wavelength generated from the fully diode-pumped laser system POLARIS. The newly generated pulses at a center wavelength of 515 nm have a pulse energy of 3 J with a pulse duration of 120 fs. On the basis of initially ultra-high contrast seed pulses we expect a temporal intensity contrast better 10 17 200 ps before the peak of the main pulse. We analyzed the temporal intensity contrast from milliseconds to femtoseconds with a dynamic range covering more than 20 orders of magnitude. The pulses were focussed with a f/2-focussing parabola resulting in a peak intensity exceeding 10 20 W / cm 2 . The peak power and intensity are to the best of our knowledge the highest values for 515 nm-laser-pulses achieved so far.

  19. Disks and outflows in the massive protobinary system W3(OH)TW

    CERN Document Server

    Zapata, Luis A; Rodríguez, Luis F; Girart, Josep M; Chen, Huei-Ru

    2011-01-01

    Sensitive and high angular resolution ($\\sim$ $0\\rlap.{"}7$) (sub)millimeter line and continuum observations of the massive star forming region W3(OH) made with the Submillimeter Array are presented. We report the first detection of two bipolar outflows emanating from the young and massive "Turner-Welch" [TW] protobinary system detected by the emission of the carbon monoxide. The outflows are massive (10 M$_\\odot$), highly-collimated (10$^\\circ$), and seem to be the extended molecular component of the strong radio jets and a 22 GHz maser water outflow energized also by the stars in the W3(OH)TW system. Observations of the 890 $\\mu$m continuum emission and the thermal emission of the CH$_3$OH might suggest the presence of two rotating circumstellar disk-like structures associated with the binary system. The disks-like structures have sizes of about 1500 AU, masses of a few M$_\\odot$ and appear to energize the molecular outflows and radio jets. We estimate that the young stars feeding the outflows and that are ...

  20. Time-Variable Accretion in the TW Hya Star/Disk System

    CERN Document Server

    Eisner, J A; Najita, J R; McCarthy, D; Kulesa, C; Swift, B J; Teske, J

    2010-01-01

    We present two epochs of observations of TW Hya from the high-dispersion near-IR spectrograph ARIES at the MMT. We detect strong emission from the Brackett gamma transition of hydrogen, indicating an accretion rate substantially larger than previously estimated using hydrogen line emission. The Brackett gamma line-strength varies across our two observed epochs. We also measure circumstellar-to-stellar flux ratios (i.e., veilings) that appear close to zero in both epochs. These findings suggest that TW Hya experiences episodes of enhanced accretion while the inner disk remains largely devoid of dust. We discuss several physical mechanisms that may explain these observations.

  1. The simulations of charged particle acceleration from gas target at 20 TW SOKOL-P laser with intensity of 5⋅1019 W/cm2

    Directory of Open Access Journals (Sweden)

    Lykov V.A.

    2013-11-01

    Full Text Available 2D PIC code simulations have been performed for the optimization of gas jet target parameters to achieve a maximal energy and efficiency of charged particle acceleration in planned experiments at the 20 TW picosecond SOKOL-P laser. These calculations specify an opportunity to obtain energy up to Ee ∼ 200 MeV and efficiency ηe ∼ 10% for accelerated electrons and Ep ∼ 30 − 50 MeV and ηp ∼ 5% for accelerated protons in these experiments at laser intensity I ∼ 5 ⋅ 1019 W/cm2. They show the necessity of providing a formation of hydrogen jets with diameter ∼ 1mm, a gas molecule concentration ∼ 2 ⋅ 1019 cm−3 and steep density gradients ∼ 200 μm at the edge of the gas jet target for achieving these parameters of laser accelerated particle beams.

  2. A new feat of powerful laser system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ CAS physicists have recently developed an intense femtosecond (fs) laser system with a peak output power of more than 350 TW. Dubbed Jiguang-Ⅲ (or XLite-Ⅲ), the work passed the acceptance check by a 10-member panel of experts under the auspices of CAS on last 27December. It was regarded as one of the best results of its kind in open literature so far.

  3. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  4. Experiment and Simulation Study on Generation of Monoenergetic Electron with Ultra-small NDA from 2 TW Laser Facility%利用2 TW 激光器产生具有超小归一化发散角的准单能电子束团的实验和模拟研究

    Institute of Scientific and Technical Information of China (English)

    李大章; 高杰

    2015-01-01

    利用2TW、80fs激光脉冲和等离子体相互作用,产生了能量为(23.0±0.8)MeV、电量为6pC的准单能电子束。该电子束的归一化发散角只有92 m rad ,较之前激光等离子体加速领域所获得的实验结果至少小了5倍以上。二维数值模拟结果显示,此结果的产生归功于加速机制上从自调制激光尾场加速向激光尾场加速的平稳过渡。%Monoenergetic electron beams with the energy of (23.0 ± 0.8) MeV and the charge of 6 pC were generated by using 2 TW and 80 fs laser pulses interacting with underdense plasmas .The beam’s normalized divergence angle is merely 92 mrad ,which is at least 5 times smaller than the published laser plasma acceleration experiment results .2D simulation and experiment data analysis results show that the significant improvement is due to the smooth transfer from self modulated laser wakefield accelera‐tion to laser wakefield acceleration .

  5. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.

    Science.gov (United States)

    Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M

    2004-12-01

    Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation.

  6. Vertically illuminated TW-UTC photodiodes for terahertz generation

    Science.gov (United States)

    Barrientos Z., Claudio M.; Calle G., Victor H.; Alvarez, Jaime A.; Mena, F. Patricio; Vukusic, Josip; Stake, Jan; Michael, Ernest A.

    2012-09-01

    More efficient and powerful continuous-wave photonic mixers as terahertz sources are motivated by the need of more versatile local oscillators for submillimeter/terahertz receiver systems. Uni-Travelling Carrier (UTC) photodiodes are very prospective candidates for reaching this objective, but so far only have been reported as lumped-elements or as edge-illuminated optical-waveguide travelling-wave (TW) devices. To overcome the associated power limitations of those implementations, we are developing a novel implementation of the UTC photodiodes which combines a travelingwave photomixer with vertical velocity-matched illumination in a distributed structure. In this implementation called velocity-matched travelling-wave uni-travelling carrier photodiode, it is possible to obtain in-situ velocity matching of the beat-fringes of the two angled laser beams with the submm/THz-wave on the stripline. In this way, minimum frequency roll-off is achieved by tuning the angle between the two laser beams. A first design of these TW-UTC PDs from our Terahertz Photonics Laboratory at University of Chile has been micro-fabricated at the MC2 cleanroom facility at Chalmers Technical University.

  7. Dual sub-picosecond and sub-nanosecond laser system

    Institute of Scientific and Technical Information of China (English)

    Xinglong Xie (谢兴龙); Guanlong Huang (黄关龙); Yifei Zhuang (庄亦飞); Aimei Han (韩爱妹); Zunqi Lin (林尊琪); Fengqiao Liu (刘凤翘); Jingxin Yang (杨镜新); Xin Yang (杨鑫); Meirong Li (李美荣); Zhiling Xue (薛之玲); Qi Gao (高奇); Fuyi Guan (管富义); Weiqing Zhang (张伟清)

    2003-01-01

    A high power laser system delivering a 20-TW, 0.5 - 0.8 ps ultra-short laser pulse and a 20-J, 500-ps long pulse simultaneously in one shot is completed. This two-beam laser operates at the wavelength of 1053 nm and uses Nd doped glass as the gain media of the main amplification chain. The chirped-pulse amplification (CPA) technology is used to compress the stretched laser pulse. After compression, the ultrashort laser pulse is measured: energy above 16.0 J, S/N contrast ratio ~ 105: 1, filling factor ~>52.7%.Another long pulse beam is a non-compressed chirped laser pulse, which is measured: energy ~ 20 J, pulse duration 500 ps. The two beams are directed onto the target surface at an angle of 15°.

  8. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  9. Heatflow in Young Oceanic Crust. Is Earth's Heat Flux 44 TW or 31 TW?

    Science.gov (United States)

    Gosnold, W. D.

    2008-05-01

    We address the question of heat flow in young oceanic crust using a 2-D finite difference heat flow model of sea floor spreading. The model parameters include thermal conductivity variation with temperature, a fixed T-z profile at the ridge that follows the mantle liquidus, constant spreading rate, and constant heat flow into the base of the lithosphere. The output of the model is a 2-D temperature-depth grid that provides a comparison with various analytical models of oceanic heat flow. We tested the reliability of the computations using different half-spreading rates and different node spacings and verified that the models yield equivalent results at equivalent times and depths. To address the question of global heat flux with respect to heat flow at oceanic spreading centers, we summed heat flux on the oceanic ridge system assuming a length of 65000 km and a half-spreading rate of 2.5 cm/y. Our results show that the GDH1, HSC, and PSM models overestimate heat flow close to the ridge, but the differences are less than 5 percent beyond 2 ma. Our model converges with GDH1 at a young age of 4.32 my and actually shows slightly lower heat flow than HSC and PSM models for ages greater than 5 ma. Total heat flux for GDH1 between 80ky and 2.32 my is 6.24 TW and our model yields 5.56 TW. Assuming agreement with heat flux over the rest of the globe, our model is only 0.68 TW different from 44TW. However, our result for heat flux in a 2 km wide section over the global ridge crest is 0.161 TW while the analytical models predict infinite heat flow.

  10. Ultrafast, ultrahigh-peak power Ti:sapphire laser system

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, Koichi; Aoyama, Makoto; Matsuoka, Shinichi; Akahane, Yutaka; Kase, Teiji; Nakano, Fumihiko; Sagisaka, Akito [Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Inst., Kizu, Kyoto (Japan)

    2001-01-01

    We review progress in the generation of multiterawatt optical pulses in the 10-fs range. We describe a design, performance and characterization of a Ti:sapphire laser system based on chirped-pulse amplification, which has produced a peak power in excess of 100-TW with sub-20-fs pulse durations and an average power of 19-W at a 10-Hz repetition rate. We also discuss extension of this system to the petawatt power level and potential applications in the relativistic, ultrahigh intensity regimes. (author)

  11. A gas laser system

    Energy Technology Data Exchange (ETDEWEB)

    Sydzo, Y.; Norio, T.

    1984-04-02

    It is reported that an improved gas laser system with active medium circulation has been developed. The design of the gas laser is given in block diagram form, and its principle of operation is described in detail. The gaseous active medium flows through the inlet hole to the laser system, and is uniformly dispersed as it flows through the cylindrical diffuser. Thus, a near uniform distribution in the flow velocity of the gas flow in the laser discharge tube is achieved. The gas flow velocity along the edges of the discharge tube exceeds somewhat the flow velocity in the central section, which aids in generating and maintaining a stable and uniform pumping discharge. It is established experimentally that when using the proposed design, the parameters of the output emission from the gas laser are improved significantly. A relationship is given which demonstrates the near linear relationship between the pumping voltage and the output emission power from a gas laser.

  12. Precision laser aiming system

    Science.gov (United States)

    Ahrens, Brandon R.; Todd, Steven N.

    2009-04-28

    A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.

  13. Wave-front correction of high-intensity fs laser beams by using closed-loop adaptive optics system

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhaohua; JIN; Zhan; ZHENG; Jiaan; WANG; Peng; WEI; Zh

    2005-01-01

    We developed an adaptive optics system to correct the wave-front distortion of an intense fs laser beam from our multi-TW laser system, Jiguang II. In this paper, the instruments of the adaptive optical system are described and the experimental results of the closed-loop wave-front correction are presented. A distorted laser wave-front of 20 wavelengths of P-V values was corrected to 0.15 wavelength of P-V values. The beam quality of the laser system varies from 3.5 diffraction limit to 1.5 diffraction limit.

  14. Comparison of TW2 and TW3 skeletal age differences in a Brazilian population Estudo comparativo das idades ósseas estimadas pelos métodos TW2 e TW3 numa população brasileira

    Directory of Open Access Journals (Sweden)

    Ana Isabel Ortega

    2006-04-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the differences between the skeletal ages estimated by TW2 and TW3 methods through their RUS and Carpal systems. MATERIAL AND METHODS: A sample of two hundred and forty hand and wrist radiographs of male and female Brazilian children aged 84-199 months was evaluated by five observers. The Dunnet test was performed for statistical analysis. RESULTS: Results showed higher skeletal ages estimated by TW2RUS than TW3RUS and Carpal for both genders. For girls a statistically significant difference (pOBJETIVO: O objetivo deste estudo foi determinar as diferenças entre as idades esqueletais estimadas pelos métodos TW2 e TW3, usando os sistemas RUS e Carpal. MATERIAL E MÉTODOS: Uma amostra de 240 radiografias de mão e punho de crianças brasileiras de ambos os sexos com idade cronológica entre 84 e 199 meses foram avaliadas por cinco observadores. Para análise estatística dos dados foi aplicado o Teste de Dunnet. RESULTADOS: Os resultados demonstraram que as idades esqueletais estimadas pelo método TW2RUS foram mais avançadas que aquelas estimadas pelos métodos TW3RUS e Carpal, para ambos os sexos. Para o sexo feminino, uma diferença estatisticamente significante (p<0,05 foi observada entre os métodos TW2RUS e TW3RUS em todas as faixas etárias estudadas. No sexo masculino, essa diferença foi observada a partir de 108 meses em diante. Em geral, idades esqueletais estimadas pelo método RUS são maiores que a idade cronológica e também maiores que a idade esqueletal estimada pelo método Carpal em ambos os sexos. A superestimativa da idade cronológica é menor quando se aplica o método TW3RUS do que ao se utilizar o método TW2RUS, e esse último sistema mostrou uma diferença estatisticamente significante em relação a idade cronológica em todas as faixas etárias das meninas, enquanto para os meninos isso foi observado apenas a partir dos 132 meses em diante. No sexo feminino, houve

  15. Read-through proteins of group 4 RNA bacteriophages TW19 and TW28. [Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Aoi, T.; Kaesberg, P.

    1976-10-01

    Group 4 phages TW19 and TW28 of Escherichia coli possess a read-through (IIb) protein, although group 2 phage GA does not. This may have implications concerning the evolution and classification of RNA phages.

  16. Ultra-fast laser system

    Science.gov (United States)

    Dantus, Marcos; Lozovoy, Vadim V

    2014-01-21

    A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

  17. Coherent laser vision system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastion, R.L. [Coleman Research Corp., Springfield, VA (United States)

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  18. Laser autostereoscopic projection system

    Science.gov (United States)

    Wang, Yuchang; Huang, Junejei

    2013-09-01

    The current autostereoscopic projection system is accomplished by array projectors. It is easy to realize optically but has a drawback with size. Another type is to place the shutter on the screen. It saves the volume but reduces the efficiency depending on how many views are produced. The shutter in the lens aperture has the same efficiency problem, too. To overcome these problems, a full HD autostereoscopic projector based on the lens aperture switching type is proposed. It has RGB laser sources and can produce 16-views or even higher stereoscopic images. This system removes the shutter in the lens aperture by the opti-mechanism itself. The specific light on the lens aperture coming from the point on the DMD is reflected to different angles. The proper angle of light is generated in the object side by the relay and folding system. The UHP lamps or the LED rays are difficult to constrain in a relative small cone angle. For this reason, the laser is applied to the design. The very small etendue of the laser is good for this architecture. The rays are combined by dichroic filter from RGB laser sources then forming and expanding to the mirror. The mirror is synchronized with DMD by the DSP control system. The images of different views are generated by DMD and specific position of the mirror. By the double lenticular screen, the lens aperture is imaged to the observer's viewing zone and the 3D scene is created.

  19. The National Ignition Facility: the World's Largest Optics and Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E I; Campbell, J H; Stolz, C J; Wuest, C R

    2003-01-27

    The National Ignition Facility, a center for the study of high energy density plasma physics and fusion energy ignition, is currently under construction at the Lawrence Livermore National Laboratory. The heart of the NIF is a frequency tripled, flashlamp-pumped Nd:glass laser system comprised of 192 independent laser beams. The laser system is capable of generating output energies of 1.8MJ at 351nm and at peak powers of 500 TW in a flexible temporal pulse format. A description of the NIF laser system and its major components is presented. We also discuss the manufacture of nearly 7500 precision large optics required by the NIF including data on the manufactured optical quality vs. specification. In addition, we present results from an on-going program to improve the operational lifetime of optics exposed to high fluence in the 351-nm section of the laser.

  20. Laser security systems

    Science.gov (United States)

    Kolev, Ivan S.; Stoeva, Ivelina S.

    2004-06-01

    This report presents the development of single-beam barrier laser security system. The system utilizes the near infrared (IR) range λ=(850-900)nm. The security system consists of several blocks: Transmitter; Receiver; Logical Unit; Indication; Power Supply. There are four individually software programmable security zones Z1 - Z4. The control logic is implemented on a PIC16F84 MCU. The infrared beam is a pulse pack, coded and modulated in the transmitter with frequency of 36 kHz. The receiver demodulates and decodes the beam. The software for the MCU is developed along with the electrical circuits of the security system.

  1. PEP Laser Surveying System

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, T.; Sah, R.C.

    1979-03-01

    A Laser Surveying System has been developed to survey the beam elements of the PEP storage ring. This system provides automatic data acquisition and analysis in order to increase survey speed and to minimize operator error. Two special instruments, the Automatic Readout Micrometer and the Small Automatic Micrometer, have been built for measuring the locations of fiducial points on beam elements with respect to the light beam from a laser. These instruments automatically encode offset distances and read them into the memory of an on-line computer. Distances along the beam line are automatically encoded with a third instrument, the Automatic Readout Tape Unit. When measurements of several beam elements have been taken, the on-line computer analyzes the measured data, compared them with desired parameters, and calculates the required adjustments to beam element support stands.

  2. Hohlraum energetics scaling to 520 TW on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kline, J. L.; Grim, G.; Kyrala, G. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Callahan, D. A.; Glenzer, S. H.; Meezan, N. B.; Moody, J. D.; Hinkel, D. E.; Jones, O. S.; MacKinnon, A. J.; Bennedetti, R.; Berger, R. L.; Bradley, D.; Dewald, E. L.; Bass, I.; Bennett, C.; Bowers, M.; Brunton, G.; Bude, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2013-05-15

    Indirect drive experiments have now been carried out with laser powers and energies up to 520 TW and 1.9 MJ. These experiments show that the energy coupling to the target is nearly constant at 84% ± 3% over a wide range of laser parameters from 350 to 520 TW and 1.2 to 1.9 MJ. Experiments at 520 TW with depleted uranium hohlraums achieve radiation temperatures of ∼330 ± 4 eV, enough to drive capsules 20 μm thicker than the ignition point design to velocities near the ignition goal of 370 km/s. A series of three symcap implosion experiments with nearly identical target, laser, and diagnostics configurations show the symmetry and drive are reproducible at the level of ±8.5% absolute and ±2% relative, respectively.

  3. A precision laser spectrometer system

    Science.gov (United States)

    Gundersen, M.; Reisler, H.; Wittig, C.

    1986-04-01

    An excimer laser based dye laser system has been purchased and integrated into experiments which involve DOD funding. The laser system is currently used in several important experiments: photodissociation of aliphatic nitro and nitroso alkanes, and halogen cyanides; bimolecular reactions of C2H, and cluster reactions of H with CO2; laser induced influorescence studies in pulsed power switches such as thyratrons. The laser system has already become an integral part of these studies, and will be used in other funded research in the future.

  4. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  5. Laser-driven electron beamlines generated by coupling laser-plasma sources with conventional transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Antici, P. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati, Via E. Fermi, 40, 00044 Frascati (Italy); SAPIENZA, University of Rome, Dip. SBAI, Via A. Scarpa 14, 00161 Rome (Italy); INFN - Sezione di Roma, c/o Dipartimento di Fisica - SAPIENZA, University of Rome, P.le Aldo Moro, 2 - 00185 Rome (Italy); Bacci, A.; Chiadroni, E.; Ferrario, M.; Rossi, A. R. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati, Via E. Fermi, 40, 00044 Frascati (Italy); Benedetti, C. [University of Bologna and INFN - Bologna (Italy); Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L. [SAPIENZA, University of Rome, Dip. SBAI, Via A. Scarpa 14, 00161 Rome (Italy); INFN - Sezione di Roma, c/o Dipartimento di Fisica - SAPIENZA, University of Rome, P.le Aldo Moro, 2 - 00185 Rome (Italy); Serafini, L. [INFN-Milan and Department of Physics, University of Milan, Via Celoria 16, 20133 Milan (Italy)

    2012-08-15

    Laser-driven electron beamlines are receiving increasing interest from the particle accelerator community. In particular, the high initial energy, low emittance, and high beam current of the plasma based electron source potentially allow generating much more compact and bright particle accelerators than what conventional accelerator technology can achieve. Using laser-generated particles as injectors for generating beamlines could significantly reduce the size and cost of accelerator facilities. Unfortunately, several features of laser-based particle beams need still to be improved before considering them for particle beamlines and thus enable the use of plasma-driven accelerators for the multiple applications of traditional accelerators. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both a versatile electron source and a controllable beam. In this paper, we perform start-to-end simulations to generate laser-driven beamlines using conventional accelerator codes and methodologies. Starting with laser-generated electrons that can be obtained with established multi-hundred TW laser systems, we compare different options to capture and transport the beams. This is performed with the aim of providing beamlines suitable for potential applications, such as free electron lasers. In our approach, we have analyzed which parameters are critical at the source and from there evaluated different ways to overcome these issues using conventional accelerator elements and methods. We show that electron driven beamlines are potentially feasible, but exploiting their full potential requires extensive improvement of the source parameters or innovative technological devices for their transport and capture.

  6. Laser-driven electron beamlines generated by coupling laser-plasma sources with conventional transport systems

    Science.gov (United States)

    Antici, P.; Bacci, A.; Benedetti, C.; Chiadroni, E.; Ferrario, M.; Rossi, A. R.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Serafini, L.

    2012-08-01

    Laser-driven electron beamlines are receiving increasing interest from the particle accelerator community. In particular, the high initial energy, low emittance, and high beam current of the plasma based electron source potentially allow generating much more compact and bright particle accelerators than what conventional accelerator technology can achieve. Using laser-generated particles as injectors for generating beamlines could significantly reduce the size and cost of accelerator facilities. Unfortunately, several features of laser-based particle beams need still to be improved before considering them for particle beamlines and thus enable the use of plasma-driven accelerators for the multiple applications of traditional accelerators. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both a versatile electron source and a controllable beam. In this paper, we perform start-to-end simulations to generate laser-driven beamlines using conventional accelerator codes and methodologies. Starting with laser-generated electrons that can be obtained with established multi-hundred TW laser systems, we compare different options to capture and transport the beams. This is performed with the aim of providing beamlines suitable for potential applications, such as free electron lasers. In our approach, we have analyzed which parameters are critical at the source and from there evaluated different ways to overcome these issues using conventional accelerator elements and methods. We show that electron driven beamlines are potentially feasible, but exploiting their full potential requires extensive improvement of the source parameters or innovative technological devices for their transport and capture.

  7. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos; Lozovoy, Vadim V.; Comstock, Matthew

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  8. WEB法儿童成年身高预测系统的实用性研究%A web system based on TW2 method in prediction of adult height for children

    Institute of Scientific and Technical Information of China (English)

    邹诚实; 陈建列; 董静波; 何广友; 郭秧君; 方略; 邢红卫; 张兆国

    2012-01-01

    Objective To evaluate the application of an user-friendly web system based on TW2 method in predicting adult height for children. Methods The equations were programmed with a java-script language in an available web system of assessment of skeletal maturity. Three hundred cases were analyzed by this new web system and manual method. The adult height was predicted and children growth chart was generated based on time of birth, sex, time of menarche (female), height, parental height, and R series of skeletal age derived from the web system of assessment of skeletal maturity,. The substitutability of the two methods was analyzed by Bland-Altman chart. The consistency of the results of the two methods in predicting adult height in childhood was compared (u test). Results Three hundred cases were studied by two skilled radiologists using both web system and manual method; the results were compared. With the web system, 94.0% predictions (282/300) were the same, the difference was within +/- 1cm in 12 cases (4%) and within +/- 2cm in 6 cases(2%). With the manual method, 75.3%(226/300) predictions was the same, the difference within +/- 1cm in 30 cases(10%),within +/- 2cm in 28 cases(9.3%), within +/- 3cm in 9 cases (3.0%), within +/- 4cm in 4 cases (1.3%), and within +/- 5cm in 3 cases (1.0%). TW2 web system was significantly better than manual method (u=6.3462,P<0.05) and more effective. Conclusion The method developed in the study provides an easy and quick prediction of adult height in childhood, which can be used for clinical evaluation of child growth.%目的 研究一种简单实用的基于TW2骨龄的WEB法儿童成年身高预测系统来代替人工法进行儿童成年身高预测.方法 用JAVA脚本执行语言在现有TW2骨龄检测系统基础上编写基于TW2骨龄的成年身高预测公式,通过访问集成有以上算法的可视化WEB页面,根据TW2骨龄检测系统计算300例受检儿童X线骨龄片得到的R骨龄,结合输入的出生日期

  9. Laser system with wavelength converter

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to an apparatus comprising a diode laser (10) providing radiation in a first wavelength interval, a radiation conversion unit (12) having an input and an output, the radiation converter configured to receive the radiation in the first wavelength interval from the diode...... laser at the input, the radiation conversion unit configured to convert the radiation in the first wavelength interval to radiation in a second wavelength interval and the output configured to output the converted radiation, the second wavelength interval having one end point outside the first...... wavelength interval. Further, the invention relates to a method of optically pumping a target laser (14) in a laser system, the laser system comprising a laser source providing radiation at a first frequency, the laser source being optically connected to an input of a frequency converter, the frequency...

  10. Toward TW-Level, Hard X-Ray Pulses at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Fawley, W.M.; Frisch, J.; Huang, Z.; Jiao, Y.; Nuhn, H.-D.; /SLAC; Pellegrini, C.; /SLAC /UCLA; Reiche, S.; /PSI, Villigen; Wu, J,; /SLAC

    2011-12-13

    Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study the feasibility of producing such pulses using a LCLS-like, low charge electron beam, as will be possible in the LCLS-II upgrade project, employing a configuration beginning with a SASE amplifier, followed by a 'self-seeding' crystal monochromator, and finishing with a long tapered undulator. Our results suggest that TW-level output power at 8.3 keV is possible from a total undulator system length around 200 m. In addition power levels larger than 100 GW are generated at the third harmonic. We present a tapering strategy that extends the original 'resonant particle' formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We discuss the transverse and longitudinal coherence properties of the output radiation pulse and the expected output pulse energy sensitivity, both to taper errors and to power fluctuations on the monochromatized SASE seed.

  11. 爱普生EMP-TW2000

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    爱普生EMP-TW2000是爱普生家用投影机中规格最高的一款产品。它具有1600流明的高亮度,两组HDMI接口。EMP-TW2000采用爱普生最新研发的0.74英寸C2Fine技术的D6液晶面板,C2 FINE技术中独有的VA(垂直取向)模式,能大幅度地减少光泄漏,

  12. Variable emissivity laser thermal control system

    Science.gov (United States)

    Milner, Joseph R.

    1994-01-01

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  13. Multiple pass laser amplifier system

    Science.gov (United States)

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  14. Laser-Plasma Acceleration with FLAME and ILIL Ultraintense Lasers

    Directory of Open Access Journals (Sweden)

    Naveen Pathak

    2013-07-01

    Full Text Available We report on the development of radiation and electron sources based on laser-plasma acceleration for biomedical and nuclear applications, using both the table top TW laser at ILIL and the 220 TW FLAME laser system at LNF. We use the ILIL laser to produce wakefield electrons in a self-focusing dominated regime in a mm scale gas-jet to generate large, uniform beams of MeV electrons for electron radiography and radiobiology applications. This acceleration regime is described in detail and key parameters are given to establish reproducible and reliable operation of this source. We use the FLAME laser to drive laser-plasma acceleration in a cm-scale gas target to obtain stable production of >100 MeV range electrons to drive a Thomson scattering ɣ-ray source for nuclear applications.

  15. Is TW Pictoris really an intermediate polar?

    CERN Document Server

    Norton, A J

    1998-01-01

    We present the results of a long ROSAT HRI observation of the candidate intermediate polar TW Pic. The power spectrum shows no sign of either the previously proposed white dwarf spin period or the proposed binary orbital period (1.996 hr and 6.06 hr respectively). The limits to the X-ray modulation are less than 0.3% in each case. In the absence of a coherent X-ray pulsation, the credentials of TW Pic for membership of the intermediate polar subclass must be suspect. We further suggest that the true orbital period of the binary may be the shorter of the two previously suggested, and that the longer period may represent a quasi-periodic phenomenon associated with the accretion disc.

  16. Swept Frequency Laser Metrology System

    Science.gov (United States)

    Zhao, Feng (Inventor)

    2010-01-01

    A swept frequency laser ranging system having sub-micron accuracy that employs multiple common-path heterodyne interferometers, one coupled to a calibrated delay-line for use as an absolute reference for the ranging system. An exemplary embodiment uses two laser heterodyne interferometers to create two laser beams at two different frequencies to measure distance and motions of target(s). Heterodyne fringes generated from reflections off a reference fiducial X(sub R) and measurement (or target) fiducial X(sub M) are reflected back and are then detected by photodiodes. The measured phase changes Delta phi(sub R) and Delta phi (sub m) resulting from the laser frequency swept gives target position. The reference delay-line is the only absolute reference needed in the metrology system and this provides an ultra-stable reference and simple/economical system.

  17. Laser photography system: hardware configuration

    Science.gov (United States)

    Piszczek, Marek; Rutyna, Krzysztof; Kowalski, Marcin; Zyczkowski, Marek

    2012-06-01

    Solution presented in this article is a system using image acquisition time gating method. The time-spatial framing method developed by authors was used to build Laser Photography System (LPS). An active vision system for open space monitoring and terrorist threats detection is being built as an effect of recent work lead in the Institute of Optoelectronics, MUT. The device is destined to prevent and recognize possible terrorist threats in important land and marine areas. The aim of this article is to discuss the properties and hardware configuration of the Laser Photography System.

  18. Underwater laser imaging system (UWLIS)

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  19. PBFA Z: A 50 TW/5 MJ Electrical Generator

    Science.gov (United States)

    Spielman, R. B.

    1997-05-01

    PBFA Z is a new 50 TW/5 MJ short electrical driver located at Sandia National Laboratories. We use PBFA Z to magnetically-implode solid or plasma shells. These configurations are historically known as z pinches. The pulsed power design of PBFA Z(R. B. Spielman, et al., Proc. of the Ninth IEEE Pulsed Power Conf., Albuquerque, NM 1995) is based on conventional single-pulse Marx generator, water-line pulse-forming technology used on the earlier Saturn (D. D. Bloomquist, et al., Proc. of the Sixth IEEE Pulsed Power Conf., Arlington, VA edited by P. J. Turchi and B. H. Bernstein (IEEE, New York, 1987), p. 310) and PBFA II(B. N. Turman, et al., Proc. of the Fifth IEEE Pulsed Power Conf., Arlington, VA 1985, pp. 155) accelerators. PBFA Z stores 11.4 MJ in its 36 Marx generators, couples 5 MJ in a 50 TW/100 ns pulse to the output water transmission lines, and delivers 3.4 MJ and 40 TW of electrical energy to the z-pinch load. Depending on the initial load inductance and the implosion time, we attain a peak current of 16-20 MA with a rise time of 105 ns. Current is fed to the z-pinch load through self magnetically-insulated transmission lines (MITLs). Peak electric fields in the MITLs exceed 2 MV /cm. The current from the four independent conical disk MITLs is combined together in a double post-hole vacuum convolute with an efficiency greater than 95%. The measured system performance of the water transmission lines, the vacuum insulator stack, the MITLs, and the double post-hole vacuum convolute differed from preshot predictions by ~ 5%. Using a 2-cm radius and a 2-cm length tungsten wire array with 240, 7.5-=B5m diameter wires (4.1-mg mass) as the z-pinch load, we achieved x-ray powers of 160 TW and x-ray energies of 1.85 MJ as measured by x-ray diodes and resistive bolometry.

  20. Adaptive High Frequency Laser Sonar System

    Science.gov (United States)

    2007-06-20

    laser vibrometers are well known in the prior art. These include commercially available systems such as the Polytec ® Model PSV-100 Scanning Laser...0029] Scanning laser vibrometer system 14 can be similar to a commercially available system such as the Polytec ® Model PSV- 100 SLVS. This system

  1. Spitzer Spectroscopy of the Transition Object TW Hya

    CERN Document Server

    Najita, Joan R; Strom, Stephen E; Watson, Dan M; Pascucci, Ilaria; Hollenbach, David; Gorti, Uma; Keller, Luke

    2010-01-01

    We report sensitive Spitzer IRS spectroscopy in the 10-20 micron region of TW Hya, a nearby T Tauri star. The unusual spectral energy distribution of the source, that of a transition object, indicates that the circumstellar disk in the system has experienced significant evolution, possibly as a result of planet formation. The spectrum we measure is strikingly different from that of other classical T Tauri stars reported in the literature, displaying no strong emission features of water, acetylene, or HCN. The difference indicates that the inner planet formation region (within 5 AU) of the gaseous disk has evolved physically and/or chemically away from the classical T Tauri norm. Nevertheless, TW Hya does show a rich spectrum of emission features of atoms (HI, [NeII], and [NeIII]) and molecules (H2, OH, CO2, HCO+, and possibly CH3), some of which are also detected in classical T Tauri spectra. The properties of the neon emission are consistent with an origin for the emission in a disk irradiated by X-rays (wit...

  2. Laser addressed holographic memory system

    Science.gov (United States)

    Gange, R. A.; Wagle, E. M.; Steinmetz, C. C.

    1973-01-01

    Holographic recall and storage system uses red-lipid microcrystalline wax as storage medium. When laser beam strikes wax, its energy heats point of incidence enough to pass wax through transition temperature. Holograph image can then be written or erased in softened wax.

  3. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.

    2016-03-31

    A system and method are provided for indoor agriculture using at least one growth chamber illuminated by laser light. In an example embodiment of the agriculture system, a growth chamber is provided having one or more walls defining an interior portion of the growth chamber. The agriculture system may include a removable tray disposed within the interior portion of the growth chamber. The agriculture system also includes a light source, which may be disposed outside the growth chamber. The one or more walls may include at least one aperture. The light source is configured to illuminate at least a part of the interior portion of the growth chamber. In embodiments in which the light source is disposed outside the growth chamber, the light source is configured to transmit the laser light to the interior portion of the growth chamber via the at least one aperture.

  4. Laser altimeter of CE-1 payloads system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The design and operation of the Laser Altimeter of CE-1 Payloads System are presented in this paper.The paper includes the design of the system and spacecraft-level laser,the description of the emitting-system and receiving system,and the testing of the laser altimeter.The CE-1 laser altimeter is the first Chinese deep-space probe using a laser.It has one beam and operates at 1 Hz,with a nominal accuracy of 5 m.The laser altimeter has operated successfully in lunar orbit since November 28,2007.It has obtained 9120 thousand data values about the lunar altitude.

  5. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Science.gov (United States)

    Martin, Randal G.; Robinson, Elisa L.

    1988-01-01

    The Automated Laser Seeker Performance Evaluation System (ALSPES), which supports the Hellfire missile and Copperhead projectile laser seekers, is discussed. The ALSPES capabilities in manual and automatic operation are described, and the ALSPES test hardware is examined, including the computer system, the laser/attenuator, optics systems, seeker test fixture, and the measurement and test equipment. The calibration of laser energy and test signals in ALSPES is considered.

  6. Fiber laser coupled optical spark delivery system

    Science.gov (United States)

    Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  7. High power laser perforating tools and systems

    Science.gov (United States)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  8. Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy

    Directory of Open Access Journals (Sweden)

    Alexei N. Kulikov

    2016-01-01

    Full Text Available Purpose. To compare three 360°-laser retinopexy (LRP approaches (using navigated pattern laser system, single-spot slit-lamp (SL laser delivery, and single-spot indirect ophthalmoscope (IO laser delivery in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods. Eighty-six rhegmatogenous retinal detachment patients (86 eyes were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale, number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system, 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients. Results. In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%, 17 (60.7%, and 13 patients (59.1%, respectively (p>0.05. Conclusion. The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope approaches with a single-spot laser.

  9. Enhanced Proton Acceleration by an Ultrashort Laser Interaction with Structured Dynamic Plasma Targets

    CERN Document Server

    Zigler, A; Botton, M; Nahum, E; Schleifer, E; Baspaly, A; Pomerantz, Y; Abicht, F; Branzel, J; Priebe, G; Steinke, S; Andreev, A; Schnuerer, M; Sandner, W; Gordon, D; Sprangle, P; Ledingham, K W D

    2013-01-01

    We experimentally demonstrate a notably enhanced acceleration of protons to high energy by relatively modest ultrashort laser pulses and structured dynamical plasma targets. Realized by special deposition of snow targets on sapphire substrates and using carefully planned pre-pulses, high proton yield emitted in a narrow solid angle with energy above 21MeV were detected from a 5TW laser. Our simulations predict that using the proposed scheme protons can be accelerated to energies above 150MeV by 100TW laser systems.

  10. Airborne laser sensors and integrated systems

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  11. BESTIA (Brookhaven Experimental Supra-Terawatt Infrared at ATF) laser: A status report

    Science.gov (United States)

    Polyanskiy, Mikhail N.; Babzien, Marcus; Pogorelsky, Igor V.

    2017-03-01

    Development of a next-generation CO2 laser aiming at 100 TW peak power at a wavelength of 10 µm ts underway at the Brookhaven Accelerator Test Facility (ATF). A new laser facility is being deployed as part of the ATF-II upgrade. New high-pressure power amplifiers are being fabricated and assembled, while R&D continues with ATF's present 2 TW CO2 laser system. Our plan for increasing the peak laser power envisions several discrete steps in the upgrade. First will be demonstration of a 10 TW capability utilizing chirped pulse amplification, with an extended power amplifier chain filled with high-pressure isotopic gas. Further development aimed at a demonstration of 25 TW operation will require the addition of a nonlinear compressor system to shrink the pulse width below the nominal gain-bandwidth limit. These upgrades will then enable a longer-term R&D effort to achieve the 100 TW goal. Over the last two years, significant R&D effort has been focused on the development of chirped-pulse amplification, the study of the behavior of optical materials under the action of high-peak-power mid-IR pulses, and the optimization of the beam quality, which is required for nonlinear pulse compression. The results of this R&D have been implemented into the ongoing operation of the ATF's CO2 laser and have already benefited our users in their experimental programs.

  12. Numerical simulation of imaging laser radar system

    Science.gov (United States)

    Han, Shaokun; Lu, Bo; Jiang, Ming; Liu, Xunliang

    2008-03-01

    Rational and effective design of imaging laser radar systems is the key of imaging laser radar system research. Design must fully consider the interrelationship between various parameters. According to the parameters, choose suitable laser, detector and other components. To use of mathematical modeling and computer simulation is an effective imaging laser radar system design methods. This paper based on the distance equation, using the detection statistical methods, from the laser radar range coverage, detection probability, false-alarm rate, SNR to build the laser radar system mathematical models. In the process of setting up the mathematical models to fully consider the laser, atmosphere, detector and other factors on the performance that is to make the models be able to respond accurately the real situation. Based on this using C# and Matlab designed a simulation software.

  13. Precision laser automatic tracking system.

    Science.gov (United States)

    Lucy, R F; Peters, C J; McGann, E J; Lang, K T

    1966-04-01

    A precision laser tracker has been constructed and tested that is capable of tracking a low-acceleration target to an accuracy of about 25 microrad root mean square. In tracking high-acceleration targets, the error is directly proportional to the angular acceleration. For an angular acceleration of 0.6 rad/sec(2), the measured tracking error was about 0.1 mrad. The basic components in this tracker, similar in configuration to a heliostat, are a laser and an image dissector, which are mounted on a stationary frame, and a servocontrolled tracking mirror. The daytime sensitivity of this system is approximately 3 x 10(-10) W/m(2); the ultimate nighttime sensitivity is approximately 3 x 10(-14) W/m(2). Experimental tests were performed to evaluate both dynamic characteristics of this system and the system sensitivity. Dynamic performance of the system was obtained, using a small rocket covered with retroreflective material launched at an acceleration of about 13 g at a point 204 m from the tracker. The daytime sensitivity of the system was checked, using an efficient retroreflector mounted on a light aircraft. This aircraft was tracked out to a maximum range of 15 km, which checked the daytime sensitivity of the system measured by other means. The system also has been used to track passively stars and the Echo I satellite. Also, the system tracked passively a +7.5 magnitude star, and the signal-to-noise ratio in this experiment indicates that it should be possible to track a + 12.5 magnitude star.

  14. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  15. Short pulse laser systems for biomedical applications

    CERN Document Server

    Mitra, Kunal

    2017-01-01

    This book presents practical information on the clinical applications of short pulse laser systems and the techniques for optimizing these applications in a manner that will be relevant to a broad audience, including engineering and medical students as well as researchers, clinicians, and technicians. Short pulse laser systems are useful for both subsurface tissue imaging and laser induced thermal therapy (LITT), which hold great promise in cancer diagnostics and treatment. Such laser systems may be used alone or in combination with optically active nanoparticles specifically administered to the tissues of interest for enhanced contrast in imaging and precise heating during LITT. Mathematical and computational models of short pulse laser-tissue interactions that consider the transient radiative transport equation coupled with a bio-heat equation considering the initial transients of laser heating were developed to analyze the laser-tissue interaction during imaging and therapy. Experiments were first performe...

  16. Laser and photonic systems design and integration

    CERN Document Server

    Nof, Shimon Y; Cheng, Gary J

    2014-01-01

    New, significant scientific discoveries in laser and photonic technologies, systems perspectives, and integrated design approaches can improve even further the impact in critical areas of challenge. Yet this knowledge is dispersed across several disciplines and research arenas. Laser and Photonic Systems: Design and Integration brings together a multidisciplinary group of experts to increase understanding of the ways in which systems perspectives may influence laser and photonic innovations and application integration.By bringing together chapters from leading scientists and technologists, ind

  17. The vulnerability of laser warning systems against guided weapons based on low power lasers

    OpenAIRE

    Al-Jaberi, Mubarak

    2006-01-01

    Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current ...

  18. Speckle analysis in laser scanning display system

    Institute of Scientific and Technical Information of China (English)

    Hong Chang; Wei Huang; Fugui Yang; Hai Ming; Jianping Xie

    2009-01-01

    The theory of speckle formation in laser scanning display system is established based on the averaging effect of eye response as laser beam scanning through an eye resolution spot.It is analyzed that speckle reduction can be obtained by averaging states of speckle during scanning.The theoretical results show that a smaller correlation length of screen surface and the narrowing of laser beam in scanning direction can reduce speckle contrast for this system.

  19. Material Processing Laser Systems For Manufacturing

    Science.gov (United States)

    Taeusch, David R.; Ruselowski, John M.

    1986-11-01

    Raycon Corporation is a builder of quality machine tools. Combining this with applications expertise to produce high technology production machinery systems using EDM, lasers and other processing methods to solve our customers' production problems is our product. The company has several standard laser machine systems which can be constructed from standard building blocks. The number of axes and travel, the controller requirements, and the required laser type, size and manufacturer are discussed with our customers, and the system to meet their needs is decided upon. These requirements are then built into a processing system for manufacturing use. Several of these systems which are in the field are described, and their purposes and how they accomplish their task are explained. Also, types of YAG and C02 lasers available are described and their optimum use explained. Some specific examples of type versus applications are: YAG low-divergence lasers for trepanning heat-resistant alloys for jet engine turbines; YAG oscillator-amplifier lasers for percussion drilling of cooling holes in jet engine turbine blades; and several special laser machine systems for processing automotive parts are discussed. A few words on laser safety are included to allay some common fears concerning the use of laser technology in the factory environment.

  20. The Electra KrF laser system

    Energy Technology Data Exchange (ETDEWEB)

    Hegeler, F; Friedman, M; Albert, T; Parish, J [Commonwealth Technology, Inc., Alexandria, VA 22315 (United States); Myers, M C; Wolford, M F; Sethian, J D; Giuliani, J L [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Burns, P [Research Support Instruments, Lanham, MD 20706 (United States); Jaynes, R [Science Applications International, Corp., McLean, VA 22102 (United States)], E-mail: frank.hegeler@nrl.navy.mil

    2008-05-15

    This paper presents a brief overview of the Electra laser system and reports on the most recent results. The laser system consists of an electron beam pumped main amplifier with an aperture of 30 cm x 30 cm, an e-beam pumped 10 cm x 10 cm pre-amplifier, and a KrF discharge laser serving as the seed oscillator. The electron beam amplifiers are pumped from both sides. Full laser system shots have been completed with a laser energy of 450 J. The main amplifier, operating as an oscillator, has demonstrated 25,000 continuous laser shots at 2.5 Hz single sided pumping as well as 16,600 shots at 2.5 Hz at {approx}300 J/shot within 2 hours.

  1. Laser Systems for Orbital Debris Removal

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; Barty, C P; Beach, R J; Erlandson, A C; Caird, J A

    2010-02-05

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  2. Microprocessor-Controlled Laser Balancing System

    Science.gov (United States)

    Demuth, R. S.

    1985-01-01

    Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

  3. Impulsive Synchronization of Laser Plasma System

    Institute of Scientific and Technical Information of China (English)

    LI Yang; LIAO Xiao-Feng; LI Chuan-Dong; CHEN Guo

    2007-01-01

    The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makes the synchronization error system a linear impulsive control system. We derive some sufficient conditions for the synchronization of a laser plasma system via impulsive control with the varying impulsive intervals, which allows us to derive the impulsive synchronization law easily. To illustrate the effectiveness of the proposed results, two numerical examples are given.

  4. Gigawatt mid-IR (4-5 μm) femtosecond hybrid Fe2+:ZnSe laser system

    Science.gov (United States)

    Potemkin, F. V.; Migal, E. A.; Pushkin, A. V.; Bravy, B. G.; Sirotkin, A. A.; Kozlovsky, V. I.; Korostelin, Yu. V.; Podmar'kov, Yu. P.; Firsov, V. V.; Frolov, M. P.; Gordienko, V. M.

    2017-05-01

    We demonstrate a first-of-its-kind efficient chirped pulse amplification of broadband mid-IR (4-5 μm) femtosecond seed pulse (230 ps, 4μJ) generated in AgGaS2 based OPA driven by Cr:forsterite laser in multi-pass Fe2+:ZnSe amplifier optically pumped by solid-state Q-switched Cr:Yb:Ho:YSGG laser (2.85 μm, 30mJ, 5Hz, 0.6 J/cm2). The system delivers 1.2 mJ at pulse duration of 230 ps. Straightforward compression to 150 fs pulse is achievable with 70% efficiency using diffraction grating pair with peak power of about 6 GW. Further non-linear compression in a bulk CaF2 due to the SPM and anomalous GVD should provide the enhancement of peak power up to 20 GW. Possible routes to reach sub-TW and even TW power level in mid-IR are discussed.

  5. ATF CO{sub 2} laser system upgrade to terawatt peak power

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelsky, I.V.

    1995-05-01

    This document describes the proposed upgrade of the 10-GW peak power 50-ps CO{sub 2} laser presently operational at the ATF to the 1 TW level at a shorter, 3--10 ps, pulse duration. The approach adopted is based on state of the art CO{sub 2} laser technology and an experience gained in the course of the ATF laser design and application for the laser accelerator experiment. The proposed upgrade is an economical way for the ATF to become in a short time among leading users facilities available for next generation ({ge} 100 MeV) laser accelerator studies.

  6. ATF CO{sub 2} laser system upgrade to terawatt peak power

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelsky, I.V.

    1995-05-01

    This document describes the proposed upgrade of the 10-GW peak power 50-ps CO{sub 2} laser presently operational at the ATF to the 1 TW level at a shorter, 3--10 ps, pulse duration. The approach adopted is based on state of the art CO{sub 2} laser technology and an experience gained in the course of the ATF laser design and application for the laser accelerator experiment. The proposed upgrade is an economical way for the ATF to become in a short time among leading users facilities available for next generation ({ge} 100 MeV) laser accelerator studies.

  7. The Theory of Random Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xunya [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Studies of random laser systems are a new direction with promising potential applications and theoretical interest. The research is based on the theories of localization and laser physics. So far, the research shows that there are random lasing modes inside the systems which is quite different from the common laser systems. From the properties of the random lasing modes, they can understand the phenomena observed in the experiments, such as multi-peak and anisotropic spectrum, lasing mode number saturation, mode competition and dynamic processes, etc. To summarize, this dissertation has contributed the following in the study of random laser systems: (1) by comparing the Lamb theory with the Letokhov theory, the general formulas of the threshold length or gain of random laser systems were obtained; (2) they pointed out the vital weakness of previous time-independent methods in random laser research; (3) a new model which includes the FDTD method and the semi-classical laser theory. The solutions of this model provided an explanation of the experimental results of multi-peak and anisotropic emission spectra, predicted the saturation of lasing modes number and the length of localized lasing modes; (4) theoretical (Lamb theory) and numerical (FDTD and transfer-matrix calculation) studies of the origin of localized lasing modes in the random laser systems; and (5) proposal of using random lasing modes as a new path to study wave localization in random systems and prediction of the lasing threshold discontinuity at mobility edge.

  8. Laser performance operations model (LPOM): The computational system that automates the setup and performance analysis of the National Ignition Facility

    Science.gov (United States)

    Shaw, Michael; House, Ronald

    2015-02-01

    The National Ignition Facility (NIF) is a stadium-sized facility containing a 192-beam, 1.8 MJ, 500-TW, 351-nm laser system together with a 10-m diameter target chamber with room for many target diagnostics. NIF is the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. A computational system, the Laser Performance Operations Model (LPOM) has been developed that automates the laser setup process, and accurately predict laser energetics. LPOM uses diagnostic feedback from previous NIF shots to maintain accurate energetics models (gains and losses), as well as links to operational databases to provide `as currently installed' optical layouts for each of the 192 NIF beamlines. LPOM deploys a fully integrated laser physics model, the Virtual Beamline (VBL), in its predictive calculations in order to meet the accuracy requirements of NIF experiments, and to provide the ability to determine the damage risk to optical elements throughout the laser chain. LPOM determines the settings of the injection laser system required to achieve the desired laser output, provides equipment protection, and determines the diagnostic setup. Additionally, LPOM provides real-time post shot data analysis and reporting for each NIF shot. The LPOM computation system is designed as a multi-host computational cluster (with 200 compute nodes, providing the capability to run full NIF simulations fully parallel) to meet the demands of both the controls systems within a shot cycle, and the NIF user community outside of a shot cycle.

  9. Laser Micro-beam Manipulation System for Cells

    Institute of Scientific and Technical Information of China (English)

    孟祥旺; 李岩; 张书练; 张志诚; 赵南明

    2002-01-01

    This paper introduces a laser micro-beam system for cells manipulation. The laser micro-beam system comprises a laser scissors and a laser tweezers, which are focused by a Nd∶YAG laser and a He-Ne laser through a microscope objective, respectively. Not only the overall design of the laser micro-beam system is discussed, but also the design and choice of the critical components. A laser micro-beam system was constructed and anticipated experiment results were gained. Yeast cells can be successfully manipulated with the laser tweezers. Chromosomes can be successfully incised with the laser scissors.

  10. Fiber-Based Ultraviolet Laser System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this program is to develop a compact and efficient ultraviolet laser system for use in space-based uv-Raman instruments. The basis for this system...

  11. Studies on Male Antifertilitic and Immunomodulatory Effects of TW19

    Institute of Scientific and Technical Information of China (English)

    王作鹏; 王晓凤; 曹霖; 陆荣发; 赵世兴; 李晓玉; 顾芝萍

    2000-01-01

    TW 19 is a diterpene compound isolated from the root cortex of Tripterygium Wilfordii Hood. F. . Its effects on the immune function in ICR mice and the male fertility in SD rats, ICR mice and Kunming mice were evaluated. TW19 was given orally for 5 weeks. Then the antifertilitic effect was assessed by mating test. The results showed that EDso for anti-fertilitic were 332 μg/kg, 369. 9 μg/kg and 286. 8 μg/kg per day in SD rats, ICR mice and Kunming mice respectively. After the treatment of TW 19 at anti fertility dose for 5 weeks consecutively, the spermatozoa density and motility of trial animals reduced significantly. The weight of testis also declined in SD rats and Kunming mice, but no effects were observed in ICR mice. TW 19 inhibited proliferation of splenic T and B-lymphocytes of ICR mice in vitro and hence inhibited the antibody formation in vivo, but compared with T 4, the immunosuppressive effect of TW 19 was less obvious.

  12. Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

    Science.gov (United States)

    Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A. D.; Scuderi, V.; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G. A. P.

    2016-07-01

    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here.

  13. EPSON(爱普生)EMP-TW2000

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    EPSON不久前推出的EMP—TW10003 LCD 1080p高清投影机自问世以来一直是人们关注的焦点之一,当热潮还未降温,EPSON紧接着又发布了最新的旗舰机种EMP-TW2000。EMP—TW2000同样是一款3LCD的1080P高清投影机,但采用了新开发的Crystal C1ear Fine(C2Fine)D7投影芯片,并且提供了对HDMI1.3a连接的支持,此外还运用了提高画面黑色表现的DEEPBLACK技术和大大扩展色域表现的x.v.Color技术,

  14. Space Applications Industrial Laser System (SAILS)

    Science.gov (United States)

    McCay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-10-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  15. Space Applications Industrial Laser System (SAILS)

    Science.gov (United States)

    Mccay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-01-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  16. The Theory of Random Laser Systems

    CERN Document Server

    Xun Ya Jian

    2002-01-01

    Studies of random laser systems are a new direction with promising potential applications and theoretical interest. The research is based on the theories of localization and laser physics. So far, the research shows that there are random lasing modes inside the systems which is quite different from the common laser systems. From the properties of the random lasing modes, they can understand the phenomena observed in the experiments, such as multi-peak and anisotropic spectrum, lasing mode number saturation, mode competition and dynamic processes, etc. To summarize, this dissertation has contributed the following in the study of random laser systems: (1) by comparing the Lamb theory with the Letokhov theory, the general formulas of the threshold length or gain of random laser systems were obtained; (2) they pointed out the vital weakness of previous time-independent methods in random laser research; (3) a new model which includes the FDTD method and the semi-classical laser theory. The solutions of this model ...

  17. Magnetically switched power supply system for lasers

    Science.gov (United States)

    Pacala, Thomas J. (Inventor)

    1987-01-01

    A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

  18. Target isolation system, high power laser and laser peening method and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  19. Rings of C2H in the Molecular Disks Orbiting TW Hya and V4046 Sgr

    CERN Document Server

    Kastner, J H; Gorti, U; Hily-Blant, P; Oberg, K; Forveille, T; Andrews, S; Wilner, D

    2015-01-01

    We have used the Submillimeter Array to image, at ~1" resolution, C2H(3-2) emission from the molecule-rich circumstellar disks orbiting the nearby, classical T Tauri star systems TW Hya and V4046 Sgr. The SMA imaging reveals that the C2H emission exhibits a ring-like morphology within each disk, the inner hole radius of the C2H ring within the V4046 Sgr disk (~70 AU) is somewhat larger than than of its counterpart within the TW Hya disk (~45 AU). We suggest that, in each case, the C2H emission likely traces irradiation of the tenuous surface layers of the outer disks by high-energy photons from the central stars.

  20. Review Of Laser Lightcraft Propulsion System

    Science.gov (United States)

    Davis, Eric W.; Mead, Franklin B.

    2008-04-01

    Laser-powered "Lightcraft" systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of a Lightcraft vehicle powered by a high-energy laser beam. One result of this study is the significant influence of laser wavelength on the power lost during laser beam propagation through Earth's atmosphere and in space. It was discovered that energy and power losses in the laser beam are extremely sensitive to wavelength for Earth-To-Orbit missions, and this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground-based laser.

  1. Laser Based 3D Volumetric Display System

    Science.gov (United States)

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  2. T.W. Adorno e a psicologia social T.W. Adorno and social psychology

    Directory of Open Access Journals (Sweden)

    José Leon Crochík

    2008-08-01

    Full Text Available Neste ensaio, ressalta-se a importância da disciplina Psicologia Social na obra de T. W. Adorno e a concepção que formula acerca dessa disciplina. Esse autor defende que há uma nova forma de configuração dos indivíduos, expressada por atitudes e comportamentos individuais padronizados e por um ego frágil, facilmente cooptado por movimentos sociais totalitários. Tais indivíduos surgem em uma sociedade caracterizada por uma forma de dominação calcada na racionalidade administrativa e tecnológica. Para esse autor, a Psicologia Social deveria estudar esse objeto para que, com o esclarecimento produzido e difundido, os indivíduos possam resistir à adesão cega a movimentos sociais irracionais, tal como o fascismo, insistindo que a determinação desses movimentos não é individual, mas social.In this assay, the importance of Social Psychology discipline in the T.W. Adorno's work and the specific conception that he formulates about it are pointed out. He defends that there is a new way of individuals' configuration, expressed by standardized attitudes and their own behaviors, such as a fragile ego, which is easily co-opted by totalitarian social movements. Such individuals appear in a society characterized by a form of domination based on administrative and technological rationality. For that author, Social Psychology would have to study this issue so that, with the enlightenment achieved and diffused, the individuals are able to resist to the blind adhesion in irrational social movements, such as the fascism. Adorno empathized that the determination of these movements is not individual, but social.

  3. Laser puncture therapy of nervous system disorders

    Energy Technology Data Exchange (ETDEWEB)

    Anishchenko, G.; Kochetkov, V.

    1984-08-29

    The authors discuss experience with treatment of nervous system disorders by means of laser-puncture therapy. Commenting on the background of the selection of this type of treatment, they explain that once researchers determined the biological action of laser light on specific nerve receptors of the skin, development of laser apparatus capable of concentrating the beam in the millimeter band was undertaken. The devices that are being used for laser-puncture are said to operate in the red helium-neon band of light. The authors identify beam parameters that have been selected for different groups of acupuncture points of the skin, and the courses of treatment (in seconds of radiation) and their time intervals. They go on to discuss the results of treatment of over 800 patients categorized in a group with disorders of the peripheral nervous system and a second group with disorders of the central nervous system.

  4. Spitzer Spectroscopy of the Transition Object TW Hya

    Science.gov (United States)

    2010-02-24

    the [NeII] line profile of TW Hya, which shows a 6 km s−1 blueshift in the emission centroid, as indicating an origin in a low-velocity...of high velocity phenomena such as magnetospheric infall would be indicated. If the lines are nar- row (> 30 km s−1) and/or with a small blueshift

  5. TwNC: a Multifaceted Dutch News Corpus

    NARCIS (Netherlands)

    Ordelman, Roeland; Jong, de Franciska; Hessen, van Arjan; Hondorp, Hendri

    2007-01-01

    This contribution describes the Twente News Corpus (TwNC), a multifaceted corpus for Dutch that is being deployed in a number of NLP research projects among which tracks within the Dutch national research programme MultimediaN, the NWO programme CATCH, and the Dutch-Flemish programme STEVIN. The de

  6. Die bisher beobachteten Ausbrueche der Zwergnova TW Vul

    Science.gov (United States)

    Wenzel, Klaus

    2016-01-01

    In the Season 2015, the Dwarf Nova TW Vul shows two outbursts. Both outbursts were discovered by Shawn Dvorak. In this publication I present the lightcurve of these observations since 2011 and the two outbursts of 2015. They are based on visual observations by Klaus Wenzel, CCD Observations of the BRT in Tenerife and CCD Observations by Shawn Dvorak (Florida USA).

  7. Gry w podmiot. Szkic o (wczesnej twórczości Mladena Stilinovicia

    Directory of Open Access Journals (Sweden)

    Magdalena Bogusławska

    2016-10-01

    Full Text Available Games of a subject: A sketch of the (early works of Mladen Stilinović The article concerns the conceptualization of the subject in the works of the contemporary Croatian visual artist Mladen Stilinović. The object of analysis are most of all works (collages, texts from the 1970s and early 1980s, when the artist formulated the basis for his creative philosophy and at the same time determined the directions of their research. His system of reference were the socialist state order and the traditionalist, academic system of artistic practice, which he criticized from the perspectives of Diogenes, philosophical Cynicism and constructive anarchism. Until this day, the attitude of resistance is the main creative principle for Stilinović’s art. He sets strong, conscious and autonomous creator’s “I” against symbolic violence of different systems (political, ideological, educational, etc.. This “I” is not so much the material and object of expression as a space of play based on concpetualism and self-irony.   Gry w podmiot. Szkic o (wczesnej twórczości Mladena Stilinovicia Artykuł dotyczy konceptualizacji podmiotu w twórczości współczesnego chorwackiego artysty wizualnego – Mladena Stilinovicia. Przedmiotem analizy są przede wszystkim prace (kolaże, teksty z lat 70. i początku 80. XX wieku, kiedy to artysta formułował podstawy filozofii twórczej i określał kierunki swych poszukiwań. Układem odniesienia były dla niego wówczas socjalistyczny porządek państwa i tradycjonalistyczny, akademicki system praktyki artystycz­nej, które poddawał konsekwentnej krytyce z pozycji rozumnego, diogenesowskiego cynizmu i konstruktywnego anarchizmu. Do dziś postawa oporu jest dla Stilinovicia podstawową zasadą twórczą. Przemocy symbolicznej wszelkich systemów (politycznych, ideologicznych, edukacyjnych itp. przeciwstawia mocne, świadome i niezależne „ja” twórcy. Jest tu ono nie tyle tworzywem i przedmiotem ekspresji

  8. ISOLDE gets a new laser system

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    It's action stations at ISOLDE, the On-Line Isotope Mass Separator at CERN. The Laboratory is preparing to add a second laser ion source system to its arsenal. By alternating between two laser systems, the ISOLDE team will be able to switch from one type of beam to another in record time.   Bruce Marsh, from the EN-STI Group, with one of the lasers from ISOLDE's current system. The first laser source for producing radioactive ion beams (see box) was installed in the ISOLDE hall in the 1990s. This method, which was highly innovative for its time, has since been adopted by several laboratories all over the world. "This laser system allows us to control the ionisation wavelength with precision and thus to select specific atoms in order to produce very pure radioactive ion beams," explains Valentin Fedosseev of the EN Department. "These beams are then used for various experiments, in nuclear astrophysics and biology, for example. With two laser systems we will be able to do ...

  9. Automated retinal robotic laser system instrumentation

    Science.gov (United States)

    Barrett, Steven F.; Wright, Cameron H. G.; Jerath, Maya R.; Lewis, R. Stephen, II; Dillard, Bryan C.; Rylander, Henry G., III; Welch, Ashley J.

    1995-05-01

    Researchers at the University of Texas at Austin's Biomedical Engineering Laser Laboratory investigating the medical applications of lasers have worked toward the development of a retinal robotic laser system. The ultimate goal of this ongoing project is to precisely place and control the depth of laser lesions for the treatment of various retinal diseases such as diabetic retinopathy and retinal tears. Researchers at the USAF Academy's Department of Electrical Engineering have also become involved with this research due to similar interests. Separate low speed prototype subsystems have been developed to control lesion depth using lesion reflectance feedback parameters and lesion placement using retinal vessels as tracking landmarks. Both subsystems have been successfully demonstrated in vivo on pigmented rabbits using an argon continuous wave laser. Work is ongoing to build a prototype system to simultaneously control lesion depth and placement. The instrumentation aspects of the prototype subsystems were presented at SPIE Conference 1877 in January 1993. Since then our efforts have concentrated on combining the lesion depth control subsystem and the lesion placement subsystem into a single prototype capable of simultaneously controlling both parameters. We have designed this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. An initial CALOSOS prototype design is provided. We have also investigated methods to improve system response time. The use of high speed non-standard frame rate CCD cameras and high speed local bus frame grabbers hosted on personal computers are being investigated. A review of system testing in vivo to date is provided in SPIE Conference proceedings 2374-49 (Novel Applications of Lasers and Pulsed Power, Dual-Use Applications of Lasers: Medical session).

  10. Fast Offset Laser Phase-Locking System

    Science.gov (United States)

    Shaddock, Daniel; Ware, Brent

    2008-01-01

    Figure 1 shows a simplified block diagram of an improved optoelectronic system for locking the phase of one laser to that of another laser with an adjustable offset frequency specified by the user. In comparison with prior systems, this system exhibits higher performance (including higher stability) and is much easier to use. The system is based on a field-programmable gate array (FPGA) and operates almost entirely digitally; hence, it is easily adaptable to many different systems. The system achieves phase stability of less than a microcycle. It was developed to satisfy the phase-stability requirement for a planned spaceborne gravitational-wave-detecting heterodyne laser interferometer (LISA). The system has potential terrestrial utility in communications, lidar, and other applications. The present system includes a fast phasemeter that is a companion to the microcycle-accurate one described in High-Accuracy, High-Dynamic-Range Phase-Measurement System (NPO-41927), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 22. In the present system (as in the previously reported one), beams from the two lasers (here denoted the master and slave lasers) interfere on a photodiode. The heterodyne photodiode output is digitized and fed to the fast phasemeter, which produces suitably conditioned, low-latency analog control signals which lock the phase of the slave laser to that of the master laser. These control signals are used to drive a thermal and a piezoelectric transducer that adjust the frequency and phase of the slave-laser output. The output of the photodiode is a heterodyne signal at the difference between the frequencies of the two lasers. (The difference is currently required to be less than 20 MHz due to the Nyquist limit of the current sampling rate. We foresee few problems in doubling this limit using current equipment.) Within the phasemeter, the photodiode-output signal is digitized to 15 bits at a sampling frequency of 40 MHz by use of the same analog

  11. New Electronic-Transition Laser Systems. Part 1. Electron Pumped Systems. Part 2. Chemically Pumped Systems

    Science.gov (United States)

    1976-12-01

    laser development . There has not yet been a demonstration of gain in a visible chemical laser systems, and it appears unlikely that practical lasers of this type will be developed in the near future. Substantial progress has been made

  12. Robotic Laser Coating Removal System

    Science.gov (United States)

    2008-07-01

    reference to ASTM  C393, Standard Test Method for Flexural Properties of  Sandwich  Constructions.  Flexure testing  of  aluminum  honeycomb   specimens...Amplification by Stimulated Emission of Radiation LHMEL Laser Hardened Materials Evaluation Laboratory MPE Maximum Permissible Exposure N2 Nitrogen NASA ...Army, Navy, Marine Corps, and National Aeronautics and Space Administration ( NASA ). In this Environmental Security Technology Certification

  13. Nova alignment and laser diagnostics systems - 1

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, E.S.; Ozarski, R.G.; Myers, D.W.; Richards, J.B.; Swift, C.D.; Boyd, R.D.; Hugenberger, R.E.; Seppala, L.G.; Parker, J.; Dryden, E.H.

    1981-01-01

    The alignment and laser diagnostic systems guide laser pulses through the separate amplifier chains to the target, measure their temporal, spatial and energy characteristics, and ensure simultaneous arrival at the target to within 5 picoseconds. Alignment tasks accomplished prior to each target shot involve automatic or remote-manual adjustments of approximately 2000 stepper motors and other actuators for the full 20 beam, 3 wavelength system. The primary detectors for alignment functions are CCD cameras with both digital and standard video output. Diagnostic data handling and processing is accomplished digitally, and both the alignment and diagnostic systems are integrated into the facility-wide digital control network.

  14. New methods for high current fast ion beam production by laser-driven acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Margarone, D.; Krasa, J.; Prokupek, J.; Velyhan, A.; Laska, L.; Jungwirth, K.; Mocek, T.; Korn, G.; Rus, B. [Institute of Physics, ASCR, v.v.i., PALS Centre, Prague (Czech Republic); Torrisi, L.; Gammino, S.; Cirrone, P.; Cutroneo, M.; Romano, F. [INFN-Laboratori Nazionali del Sud, Catania, Messina University (Italy); Picciotto, A.; Serra, E. [Fondazione Bruno Kessler - IRST, Trento (Italy); Giuffrida, L. [CELIA, Centre Lasers Intenses et Applications (France); Mangione, A. [ITA - Istituto Tecnologie Avanzate, Trapani (Italy); Rosinski, M.; Parys, P. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); and others

    2012-02-15

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10{sup 16}-10{sup 19} W/cm{sup 2}. The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  15. New methods for high current fast ion beam production by laser-driven accelerationa)

    Science.gov (United States)

    Margarone, D.; Krasa, J.; Prokupek, J.; Velyhan, A.; Torrisi, L.; Picciotto, A.; Giuffrida, L.; Gammino, S.; Cirrone, P.; Cutroneo, M.; Romano, F.; Serra, E.; Mangione, A.; Rosinski, M.; Parys, P.; Ryc, L.; Limpouch, J.; Laska, L.; Jungwirth, K.; Ullschmied, J.; Mocek, T.; Korn, G.; Rus, B.

    2012-02-01

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 1016-1019 W/cm2. The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  16. New methods for high current fast ion beam production by laser-driven acceleration.

    Science.gov (United States)

    Margarone, D; Krasa, J; Prokupek, J; Velyhan, A; Torrisi, L; Picciotto, A; Giuffrida, L; Gammino, S; Cirrone, P; Cutroneo, M; Romano, F; Serra, E; Mangione, A; Rosinski, M; Parys, P; Ryc, L; Limpouch, J; Laska, L; Jungwirth, K; Ullschmied, J; Mocek, T; Korn, G; Rus, B

    2012-02-01

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10(16)-10(19) W∕cm(2). The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  17. A Modular Laser Graphics Projection System

    Science.gov (United States)

    Newswanger, Craig D.

    1984-05-01

    WED Enterprises has designed and built a modular projection system for the presentation of animated laser shows. This system was designed specifically for use in Disney theme shows. Its modular design allows it to be adapted to many show situations with simple hardware and software adjustments. The primary goals were superior animation, long life, low maintenance and stand alone operation.

  18. Binary Laser Direct Writing System and Its Applications

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new laser direct writing system is introduced and the potential application of the diffractive optical elements (DOE's) fabricated by applying laser direct writing system are presented. The fabrication techniques by applying the laser direct writing are developed. Experimental results have been obtained by applying laser direct writing machine with line width of 5μm and 10μm.

  19. Accidental human laser retinal injuries from military laser systems

    Science.gov (United States)

    Stuck, Bruce E.; Zwick, Harry; Molchany, Jerome W.; Lund, David J.; Gagliano, Donald A.

    1996-04-01

    The time course of the ophthalmoscopic and functional consequences of eight human laser accident cases from military laser systems is described. All patients reported subjective vision loss with ophthalmoscopic evidence of retinal alteration ranging from vitreous hemorrhage to retinal burn. Five of the cases involved single or multiple exposures to Q-switched neodymium radiation at close range whereas the other three incidents occur over large ranges. Most exposures were within 5 degrees of the foveola, yet none directly in the foveola. High contrast visual activity improved with time except in the cases with progressive retinal fibrosis between lesion sites or retinal hole formation encroaching the fovea. In one patient the visual acuity recovered from 20/60 at one week to 20/25 in four months with minimal central visual field loss. Most cases showed suppression of high and low spatial frequency contrast sensitivity. Visual field measurements were enlarged relative to ophthalmoscopic lesion size observations. Deep retinal scar formation and retinal traction were evident in two of the three cases with vitreous hemorrhage. In one patient, nerve fiber layer damage to the papillo-macular bundle was clearly evident. Visual performance measured with a pursuit tracking task revealed significant performance loss relative to normal tracking observers even in cases where acuity returned to near normal levels. These functional and performance deficits may reflect secondary effects of parafoveal laser injury.

  20. Preference of Chaotic Synchronization in a Coupled Laser System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yun; ZHU Shi-Qun; WU Liang

    2005-01-01

    In a coupled laser system, the dynamics of the receiving laser is investigated when two separate transmitting lasers are injected into the receiving laser with different coupling strengths. It is shown that the phenomenon of preference of chaotic synchronization appears under appropriate coupling conditions. The receiving laser will entrain the pulses of either one or both transmitting lasers when the coupling is strong while it keeps its own dynamics when the coupling is weak.

  1. PHASE NOISE COMPARISON OF SHORT PULSE LASER SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Shukui Zhang; Stephen Benson; John Hansknecht; David Hardy; George Neil; Michelle D. Shinn

    2006-08-27

    This paper describes phase noise measurements of several different laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on state-of-the-art short pulse lasers, especially drive lasers for photocathode injectors. Phase noise comparison of the FEL drive laser, electron beam and FEL laser output also will be presented.

  2. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    of a variety of skin conditions, primarily chronically photodamaged skin, but also acne and burn scars. In addition, it is anticipated that AFR can be utilized in the laser-assisted delivery of topical drugs. Clinical efficacy coupled with minimal downtime has driven the development of various fractional...... ablative laser systems. Fractionated CO(2) (10,600-nm), erbium yttrium aluminum garnet, 2940-nm and yttrium scandium gallium garnet, 2790-nm lasers are available. In this article, we present an overview of AFR technology, devices and histopathology, and we summarize the current clinical possibilities...... with AFR incorporating our personal experience. AFR is still in the exploratory era, and systematic investigations of clinical outcomes related to various system settings are needed....

  3. Laser beam shaping and packaging system

    Science.gov (United States)

    Luo, Daxin; Zhao, Baiqin

    2012-10-01

    This paper presents a semiconductor laser beam shaping system, that can collimate the irradiance profile effectively and package the laser diode(LD) at the same time. Due to the semiconductor LD is a kind of line source, a particular ellipsoidal lens is designed after both the fast-axis and the slow-axis of the laser beam analyzed. Geometrical optics analysis based on the ray tracing method is done and the formulas to calculate the shape of the lens are given. Both the theoretical and experimental result show that the laser beam system works effectively; the divergence angle is reduced to less than 0.5 degree in the fast-axial direction and 1.8 degree in the slow-axial direction. In addition, it is the same process that makes the laser beam shaper and packages the LD by using epoxy resin, which simplifies the manufacturing process and reduces the LD volume greatly. Because of the advantages of small volume, low-cost, high rigidity and easy fabrication, the shaper is of great value in the field of semiconductor LD applications.

  4. Kinetic modelling of krypton fluoride laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Jancaitis, K.S.

    1983-11-01

    A kinetic model has been developed for the KrF* rare gas halide laser system, specifically for electron-beam pumped mixtures of krypton, fluorine, and either helium or argon. The excitation produced in the laser gas by the e-beam was calculated numerically using an algorithm checked by comparing the predicted ionization yields in the pure rare gases with their experimental values. The excitation of the laser media by multi-kilovolt x-rays was also modeled and shown to be similar to that produced by high energy electrons. A system of equations describing the transfer of the initial gas excitation into the laser upper level was assembled using reaction rate constants from both experiment and theory. A one-dimensional treatment of the interaction of the laser radiation with the gas was formulated which considered spontaneous and stimulated emission and absorption. The predictions of this model were in good agreement with the fluorescence signals and gain and absorption measured experimentally.

  5. Lunar-based Ultraviolet Telescope study of the well-known Algol-type binary TW Dra

    Science.gov (United States)

    Liao, Wen-Ping; Qian, Sheng-Bang; Zejda, Miloslav; Zhu, Li-Ying; Li, Lin-Jia

    2016-06-01

    By using the Lunar-based Ultraviolet Telescope (LUT) from 2014 December 2 to December 4, the first near-UV light curve of the well-known Algol-type binary TW Dra is reported, which is analyzed with the 2013 version of the W-D code. Our solutions confirmed that TW Dra is a semi-detached binary system where the secondary component fills its Roche lobe. The mass ratio and a high inclination are obtained (q = 0.47, i = 86.68°). Based on 589 available data spanning more than one century, the complex period changes are studied. Secular increase and three cyclical changes are found in the corresponding orbital period analysis. The secular increase changes reveal mass transfer from the secondary component to the primary one at a rate of 6.8 × 10-7 M ⊙ yr-1. One large cyclical change of 116.04 yr may be caused by disturbance of visual component ADS 9706B orbiting TW Dra (ADS 9706A), while the other two cyclical changes with shorter periods of 22.47 and 37.27 yr can be explained as the result of two circumbinary companions that are orbiting around TW Dra, where the two companions are in simple 3 : 5 orbit-rotation resonances. TW Dra itself is a basic binary in a possible sextuple system with the configuration (1 + 1) + (1 + 1) + (1 + 1), which further suggests that multiplicity may be a fairly common phenomenon in close binary systems.

  6. Potential aquaculture probiont Lactococcus lactis TW34 produces nisin Z and inhibits the fish pathogen Lactococcus garvieae.

    Science.gov (United States)

    Sequeiros, Cynthia; Garcés, Marisa E; Vallejo, Marisol; Marguet, Emilio R; Olivera, Nelda L

    2015-04-01

    Bacteriocin-producing Lactococcus lactis TW34 was isolated from marine fish. TW34 bacteriocin inhibited the growth of the fish pathogen Lactococcus garvieae at 5 AU/ml (minimum inhibitory concentration), whereas the minimum bactericidal concentration was 10 AU/ml. Addition of TW34 bacteriocin to L. garvieae cultures resulted in a decrease of six orders of magnitude of viable cells counts demonstrating a bactericidal mode of action. The direct detection of the bacteriocin activity by Tricine-SDS-PAGE showed an active peptide with a molecular mass ca. 4.5 kDa. The analysis by MALDI-TOF-MS detected a strong signal at m/z 2,351.2 that corresponded to the nisin leader peptide mass without the initiating methionine, whose sequence STKDFNLDLVSVSKKDSGASPR was confirmed by MS/MS. Sequence analysis of nisin structural gene confirmed that L. lactis TW34 was a nisin Z producer. This nisin Z-producing strain with probiotic properties might be considered as an alternative in the prevention of lactococcosis, a global disease in aquaculture systems.

  7. The design of laser scanning galvanometer system

    Science.gov (United States)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  8. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  9. Method and system for powering and cooling semiconductor lasers

    Science.gov (United States)

    Telford, Steven J; Ladran, Anthony S

    2014-02-25

    A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.

  10. The study of laser beam riding guided system based on 980nm diode laser

    Science.gov (United States)

    Qu, Zhou; Xu, Haifeng; Sui, Xin; Yang, Kun

    2015-10-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  11. Transition of the BELLA PW laser system towards a collaborative research facility in laser plasma science

    Science.gov (United States)

    Toth, Csaba; Evans, Dave; Gonsalves, Anthony J.; Kirkpatrick, Mark; Magana, Art; Mannino, Greg; Mao, Hann-Shin; Nakamura, Kei; Riley, Joe R.; Steinke, Sven; Sipla, Tyler; Syversrud, Don; Ybarrolaza, Nathan; Leemans, Wim P.

    2017-03-01

    The advancement of Laser-Plasma Accelerators (LPA) requires systematic studies with ever increasing precision and reproducibility. A key component of such a research endeavor is a facility that provides reliable, well characterized laser sources, flexible target systems, and comprehensive diagnostics of the laser pulses, the interaction region, and the produced electron beams. The Berkeley Lab Laser Accelerator (BELLA), a PW laser facility, now routinely provides high quality focused laser pulses for high precision experiments. A description of the commissioning process, the layout of the laser systems, the major components of the laser and radiation protection systems, and a summary of early results are given. Further scientific plans and highlights of operational experience that serve as the basis for transition to a collaborative research facility in high-peak power laser-plasma interaction research are reviewed.

  12. A simplified 461-nm laser system using blue laser diodes and a hollow cathode lamp for laser cooling of Sr

    CERN Document Server

    Shimada, Yosuke; Ohtsubo, Nozomi; Aoki, Takatoshi; Torii, Yoshio

    2013-01-01

    We develop a simplified light source at 461 nm for laser cooling of Sr without frequency-doubling crystals but with blue laser diodes. An anti-reflection coated blue laser diode in an external cavity (Littrow) configuration provides an output power of 40 mW at 461 nm. Another blue laser diode is used to amplify the laser power up to 110 mW by injection locking. For frequency stabilization, we demonstrate modulation-free polarization spectroscopy of Sr in a hollow cathode lamp. The simplification of the laser system achieved in this work is of great importance for the construction of transportable optical lattice clocks.

  13. A simplified 461-nm laser system using blue laser diodes and a hollow cathode lamp for laser cooling of Sr.

    Science.gov (United States)

    Shimada, Yosuke; Chida, Yuko; Ohtsubo, Nozomi; Aoki, Takatoshi; Takeuchi, Makoto; Kuga, Takahiro; Torii, Yoshio

    2013-06-01

    We develop a simplified light source at 461 nm for laser cooling of Sr without frequency-doubling crystals but with blue laser diodes. An anti-reflection coated blue laser diode in an external cavity (Littrow) configuration provides an output power of 40 mW at 461 nm. Another blue laser diode is used to amplify the laser power up to 110 mW by injection locking. For frequency stabilization, we demonstrate modulation-free polarization spectroscopy of Sr in a hollow cathode lamp. The simplification of the laser system achieved in this work is of great importance for the construction of transportable optical lattice clocks.

  14. Performance of the ATLAS Tile LaserII Calibration System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00124895; The ATLAS collaboration

    2015-01-01

    The new laser calibration system of the ATLAS Tile hadron calorimeter is presented. The perfomances of the calibration and monitor tools internal to the laser system are given in terms of operation time stability. The use of the laser system in the normal Tile calibration procedures is also described.

  15. Space Applications of Industrial Laser Systems (SAILS)

    Science.gov (United States)

    Mueller, Robert E.; McCay, T. Dwayne; McCay, Mary Helen; Bible, Brice

    1995-01-01

    A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use on Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into the standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at the University of Tennessee Space Institute (UTSI) and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.

  16. High-frequency laser sonar system

    Science.gov (United States)

    Cray, Benjamin A.; Sarma, Ashwin; Kirsteins, Ivars P.

    2002-11-01

    A set of measurements recently completed at the Naval Undersea Warfare Center (NUWC) demonstrated that a laser-based sonar system can be used to detect acoustic particle velocity on the surface of a thin acoustically-compliant plate embedded beneath a standard acoustic window. The theoretical acoustic and measured surface particle velocity varied by less than 1 dB (reference m/s) over a wide frequency band (10 kHz to 100 kHz). However, the Polytec Model PSV-100 Scanning Laser Vibrometer System (SLVS) used in the experiments had relatively poor acoustic sensitivity, presumably due to high electronic noise, speckle noise, stand-off distance, and drifting laser focus. The laser's acoustic sensitivity appears to be inversely proportional to the backscatter signal level. The existing SLVS can sample a grid of 512 by 512 points, with each grid point having a spot size of approximately 10 mm (0.0004 in.). Such fine sampling may be used to create essentially a continuous aperture, eliminating acoustic grating lobes at all frequencies of practical sonar interest.

  17. Commercialization plan laser-based decoating systems

    Energy Technology Data Exchange (ETDEWEB)

    Freiwald, J.; Freiwald, D.A.

    1998-01-01

    F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ``document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.`` This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2`s commercialization and marketing plans are described, including how F2`s organization is structured to meet the needs of technology commercialization, F2`s strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed.

  18. Three-component laser anemometer measurement systems

    Science.gov (United States)

    Goldman, Louis J.

    1991-01-01

    A brief overview of the different laser anemometer (LA) optical designs available is presented. Then, the LA techniques that can be used to design a three-component measurement system for annular geometries are described. Some of the facility design considerations unique to these LA systems are also addressed. Following this, the facilities and the LA systems that were used to successfully measure the three components of velocity in the blading of annular-flow machines are reviewed. Finally, possible LA system enhancements and future research directions are presented.

  19. TIR-1 carbon dioxide laser system for fusion

    Science.gov (United States)

    Adamovich, V. A.; Anisimov, V. N.; Afonin, E. A.; Baranov, V. Iu.; Borzenko, V. L.; Kozochkin, S. M.; Maliuta, D. D.; Satov, Iu. A.; Sebrant, A. Iu.; Smakovski, Iu. B.

    1980-03-01

    The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system consists of an oscillator-preamplifier that produces about 1-nsec laser pulse with an energy contrast ratio of 1 million, a large triple-pass amplifier, and a target chamber with diagnostic equipment.

  20. Phase Noise Comparision of Short Pulse Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. Zhang; S. V. Benson; J. Hansknecht; D. Hardy; G. Neil; Michelle D. Shinn

    2006-12-01

    This paper describes the phase noise measurement on several different mode-locked laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on the state of the art short pulse lasers, especially the drive lasers for photocathode injectors. A comparison between the phase noise of the drive laser pulses, electron bunches and FEL pulses will also be presented.

  1. Development of on-line laser power monitoring system

    Science.gov (United States)

    Ding, Chien-Fang; Lee, Meng-Shiou; Li, Kuan-Ming

    2016-03-01

    Since the laser was invented, laser has been applied in many fields such as material processing, communication, measurement, biomedical engineering, defense industries and etc. Laser power is an important parameter in laser material processing, i.e. laser cutting, and laser drilling. However, the laser power is easily affected by the environment temperature, we tend to monitor the laser power status, ensuring there is an effective material processing. Besides, the response time of current laser power meters is too long, they cannot measure laser power accurately in a short time. To be more precisely, we can know the status of laser power and help us to achieve an effective material processing at the same time. To monitor the laser power, this study utilize a CMOS (Complementary metal-oxide-semiconductor) camera to develop an on-line laser power monitoring system. The CMOS camera captures images of incident laser beam after it is split and attenuated by beam splitter and neutral density filter. By comparing the average brightness of the beam spots and measurement results from laser power meter, laser power can be estimated. Under continuous measuring mode, the average measuring error is about 3%, and the response time is at least 3.6 second shorter than thermopile power meters; under trigger measuring mode which enables the CMOS camera to synchronize with intermittent laser output, the average measuring error is less than 3%, and the shortest response time is 20 millisecond.

  2. High power laser workover and completion tools and systems

    Science.gov (United States)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-10-28

    Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

  3. Laser beam riding guided system principle and design research

    Science.gov (United States)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  4. Optical diagnostics integrated with laser spark delivery system

    Science.gov (United States)

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-09-02

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  5. Testing relativity again, laser, laser, laser, laser

    NARCIS (Netherlands)

    Einstein, A.

    2015-01-01

    laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser,

  6. Uncertainties in water chemistry in disks: An application to TW Hydrae

    Science.gov (United States)

    Kamp, I.; Thi, W.-F.; Meeus, G.; Woitke, P.; Pinte, C.; Meijerink, R.; Spaans, M.; Pascucci, I.; Aresu, G.; Dent, W. R. F.

    2013-11-01

    Context. This paper discusses the sensitivity of water lines to chemical processes and radiative transfer for the protoplanetary disk around TW Hya. The study focuses on the Herschel spectral range in the context of new line detections with the PACS instrument from the Gas in Protoplanetary Systems project (GASPS). Aims: The paper presents an overview of the chemistry in the main water reservoirs in the disk around TW Hya. It discusses the limitations in the interpretation of observed water line fluxes. Methods: We use a previously published thermo-chemical Protoplanetary Disk Model (ProDiMo) of the disk around TW Hya and study a range of chemical modeling uncertainties: metallicity, C/O ratio, and reaction pathways and rates leading to the formation of water. We provide results for the simplified assumption of Tgas = Tdust to quantify uncertainties arising for the complex heating/cooling processes of the gas and elaborate on limitations due to water line radiative transfer. Results: We report new line detections of p-H2O (322-211) at 89.99 μm and CO J = 18-17 at 144.78 μm for the disk around TW Hya. Disk modeling shows that the far-IR fine structure lines ([O i], [C ii]) and molecular submm lines are very robust to uncertainties in the chemistry, while the water line fluxes can change by factors of a few. The water lines are optically thick, sub-thermally excited and can couple to the background continuum radiation field. The low-excitation water lines are also sensitive to uncertainties in the collision rates, e.g. with neutral hydrogen. The gas temperature plays an important role for the [O i] fine structure line fluxes, the water line fluxes originating from the inner disk as well as the high excitation CO, CH+ and OH lines. Conclusions: Due to their sensitivity on chemical input data and radiative transfer, water lines have to be used cautiously for understanding details of the disk structure. Water lines covering a wide range of excitation energies provide

  7. ACTD Laser Line Scan System

    Science.gov (United States)

    1997-09-30

    communications with a computer system in the MILVAN. For the ACTD a single board computer dedicated to the EOID Sensor will be inserted into GEM. This... single board computer will provide real time control of the EOID Sensor. Since the bandwidth of the microwave data link is smaller than the data rate of...EOID Sensor image data will be maintained in a circular buffer on the single board computer in GEM. Upon command, full resolution data from any segment

  8. Performance of laser based optical imaging system

    Science.gov (United States)

    Shah, Dhrupesh S.; Banerjee, Arup; Vora, Anup; Biswas, Amiya; Patel, Naimesh; Kurulkar, Amit; Dutt, Ashutosh

    2016-05-01

    Day night imaging application requires high dynamic range optical imaging system to detect targets of interest covering mid-day (>32000 Lux)[1], and moonless night ( 1mLux)[1] under clear sky- (visibility of >10km, atmospheric loss of 500m, atmospheric loss of >15dB/Km) conditions. Major governing factors for development of such camera systems are (i) covert imaging with ability to identify the target, (ii) imaging irrespective to the scene background, (iii) reliable operation , (iv) imaging capabilities in inclement weather conditions, (v) resource requirement vs availability power & mass, (vi) real-time data processing, (vii) self-calibration, and (viii) cost. Identification of optimum spectral band of interest is most important to meet these requirements. Conventional detection systems sensing in MWIR and LWIR band has certain draw backs in terms of target detection capabilities, susceptibility to background and huge thermo-mechanical resource requirement. Alternatively, range gated imaging camera system sensing in NIR/SWIR spectrum has shown significant potential to detect wide dynamic range targets. ToF Camera configured in NIR band has certain advantages in terms of Focal Plane Assembly (FPA) development with large format detectors and thermo-mechanical resource requirement compared to SWIR band camera configuration. In past, ToF camera systems were successfully configured in NIR spectrum using silicon based Electron Multiplying CCD (EMCCD), Intensifier CCD (ICCD) along with Gating device and pulsed laser source having emission in between 800nm to 900nm. However, these systems have a very low dynamic range and not suitable for clear sky mid-day conditions. Recently silicon based scientific grade CMOS image sensors have shown significant improvement in terms of high NIR responsivity and available in bigger formats (5MP or more), adequate Full well capacity for day time imaging (>30Ke), very low readout noise (<2e) required for night imaging and higher frame

  9. Strong tW Scattering at the LHC

    CERN Document Server

    Dror, Jeff Asaf; Salvioni, Ennio; Serra, Javi

    2016-01-01

    Deviations of the top electroweak couplings from their Standard Model values imply that certain amplitudes for the scattering of third generation fermions and longitudinally polarized vector bosons or Higgses diverge quadratically with momenta. This high-energy growth is a genuine signal of models where the top quark is strongly coupled to the sector responsible for electroweak symmetry breaking. We propose to profit from the high energies accessible at the LHC to enhance the sensitivity to non-standard top-$Z$ couplings, which are currently very weakly constrained. To demonstrate the effectiveness of the approach, we perform a detailed analysis of $tW \\to tW$ scattering, which can be probed at the LHC via $pp\\to t\\bar{t}Wj$. By recasting a CMS analysis at 8 TeV, we derive the strongest direct bounds to date on the $Ztt$ couplings. We also design a dedicated search at 13 TeV that exploits the distinctive features of the $t\\bar{t}Wj$ signal. Finally, we present other scattering processes in the same class that...

  10. Mathematical model for light scanning system based on circular laser

    Institute of Scientific and Technical Information of China (English)

    Peiquan Xu; Shun Yao; Fenggui Lu; Xinhua Tang; Wei Zhang

    2005-01-01

    A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built.This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams,escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in "spot" or "line" type laser trajectory. Three-dimensional (3D) model for welded seams could be recognized after depth recovery. The imaging error is investigated also.

  11. Laser Research and Development Studies for Laser Guide Star Systems

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, D.; Beach, R.; Ebbers, C.; Erbert, G.; Nguyen, H.; Page, R.; Payne, S.; Perry, M.

    2000-02-23

    In this paper we consider two CW solid state laser approaches to a 589 nm LGS system. Both are based on the technique of sum-frequency generation, but differ in the cavity architecture. Both technologies are very promising and are worth of further consideration. This preliminary proposal is intended to encompass both designs. A down select shall be performed early in the project execution to focus on the most promising option. The two design options consist of: (1) A dual-frequency resonator with intra-cavity doubling in LB0 offers the promise of a simple architecture and may scale more easily to high power. This design has been shown to be highly reliable, efficient and high power when used in frequency-doubled Nd:YAG lasers for programs at LLNL and in commercial products. The challenge in this design is the demonstration of a high power13 18 nm oscillator with adequate suppression of the 1064 nm line. (2) A MOPA based design uses commercial low power oscillators to produce both wavelengths, then amplifies the wavelengths before doubling. This design requires the demonstration of a 1318 nm amplifier, though the design is scaled from a kW CW amplifier already delivered to a customer at a different wavelength. The design must also demonstrate high power scaling of sum-frequency generation in the relatively new nonlinear material, PPLN. The first step in the process would be to further evaluate the two conceptual options for technical feasibility, cost and constructability. Then a down selection to one design would be conducted. Finally, R&D on that design would then proceed. Minimal testing should be required for this selection. The majority of the funding received would be allocated to development of the design selected.

  12. Solid-state laser system for laser cooling of Sodium

    CERN Document Server

    Mimoun, Emmanuel; Zondy, Jean-Jacques; Dalibard, Jean; Gerbier, Fabrice

    2009-01-01

    We demonstrate a frequency-stabilized, all-solid laser source at 589 nm with up to 800 mW output power. The laser relies on sum-frequency generation from two laser sources at 1064 nm and 1319 nm through a PPKTP crystal in a doubly-resonant cavity. We obtain conversion efficiency as high as 2 W/W^2 after optimization of the cavity parameters. The output wavelength is tunable over 60 GHz, which is sufficient to lock on the Sodium D2 line. The robustness, beam quality, spectral narrowness and tunability of our source make it an alternative to dye lasers for atomic physics experiments with Sodium atoms.

  13. SMI of Bcl-2 TW-37 is active across a spectrum of B-cell tumors irrespective of their proliferative and differentiation status.

    Science.gov (United States)

    Al-Katib, Ayad M; Sun, Yuan; Goustin, Anton Scott; Azmi, Asfar Sohail; Chen, Ben; Aboukameel, Amro; Mohammad, Ramzi M

    2009-02-16

    The Bcl-2 family of proteins is critical to the life and death of malignant B-lymphocytes. Interfering with their activity using small-molecule inhibitors (SMI) is being explored as a new therapeutic strategy for treating B-cell tumors. We evaluated the efficacy of TW-37, a non-peptidic SMI of Bcl-2 against a range spectrum of human B-cell lines, fresh patient samples and animal xenograft models. Multiple cytochemical and molecular approaches such as acridine orange/ethidium bromide assay for apoptosis, co-immunoprecipitation of complexes and western blot analysis, caspase luminescent activity assay and apoptotic DNA fragmentation assay were used to demonstrate the effect of TW-37 on different B-cell lines, patient derived samples, as well as in animal xenograft models. Nanomolar concentrations of TW-37 were able to induce apoptosis in both fresh samples and established cell lines with IC50 in most cases of 165-320 nM. Apoptosis was independent of proliferative status or pathological classification of B-cell tumor. TW-37 was able to block Bim-Bcl-XL and Bim-Mcl-1 heterodimerization and induced apoptosis via activation of caspases -9, -3, PARP and DNA fragmentation. TW-37 administered to tumor-bearing SCID mice led to significant tumor growth inhibition (T/C), tumor growth delay (T-C) and Log10kill, when used at its maximum tolerated dose (40 mg/kg x 3 days) via tail vein. TW-37 failed to induce changes in the Bcl-2 proteins levels suggesting that assessment of baseline Bcl-2 family proteins can be used to predict response to the drug. These findings indicate activity of TW-37 across the spectrum of human B-cell tumors and support the concept of targeting the Bcl-2 system as a therapeutic strategy regardless of the stage of B-cell differentiation.

  14. Development of a Selectable Output Ultraviolet Laser System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Here, we propose to develop a breadboard laser system that is capable of producing radiation in two UV wavelengths.  This Selectable Output Ultraviolet Laser...

  15. Hybrid high power femtosecond laser system

    Science.gov (United States)

    Trunov, V. I.; Petrov, V. V.; Pestryakov, E. V.; Kirpichnikov, A. V.

    2006-01-01

    Design of a high-power femtosecond laser system based on hybrid chirped pulse amplification (CPA) technique developed by us is presented. The goal of the hybrid principle is the use of the parametric and laser amplification methods in chirped pulse amplifiers. It makes it possible to amplify the low-cycle pulses with a duration of <= fs to terawatt power with a high contrast and high conversion efficiency of the pump radiation. In a created system the Ti:Sapphire laser with 10 fs pulses at 810 nm and output energy about 1-3 nJ will be used like seed source. The oscillator pulses were stretched to duration of about 500 ps by an all-reflective grating stretcher. Then the stretched pulses are injected into a nondegenerate noncollinear optical parametric amplifier (NOPA) on the two BBO crystals. After amplification in NOPA the residual pump was used in a bow-tie four pass amplifier with hybrid active medium (based on Al II0 3:Ti 3+ and BeAl IIO 4:Ti 3+ crystals). The final stage of the amplification system consists of two channels, namely NIR (820 nm) and short-VIS (410 nm). Numerical simulation has shown that the terawatt level of output power can be achieved also in a short-VIS channel at the pumping of the double-crystal BBO NOPA by the radiation of the fourth harmonic of the Nd:YAG laser at 266 nm. Experimentally parametric amplification in BBO crystals of 30-50 fs pulses were investigated and optimized using SPIDER technique and single-shot autocomelator for the realization of shortest duration 40 fs.

  16. LISP: a laser imaging simulation package for developing and testing laser vision systems

    Science.gov (United States)

    Wu, Kung C.

    1993-01-01

    The difficulties commonly encountered in developing laser imaging technologies are: (1) high cost of the laser system, and (2) time and cost involved in modeling and maneuvering a physical environment for the desired scenes. In contrast to the real imaging systems, computer generated laser images provide researchers with fast, accurate, cost-effective data for testing and developing algorithms. The laser imaging simulation package (LISP) described in this paper provides an interactive solid modeler that allows users to construct the artificial environment by various solid modelling techniques. Two fast ray tracing algorithms were developed and discussed in this paper for generating the near realistic laser data of any desired scene. These computer generated laser data facilitates the researchers in developing laser imaging algorithms. Thus, LISP not only provides an ideal testbed for developing and testing algorithms, but also an opportunity to explore the limitation of laser imaging applications.

  17. Mode-Locked Semiconductor Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Oxenløwe, Leif Katsuo

    2005-01-01

    We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized.......We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized....

  18. Low temperature thermal windowing (TW) thermally stimulated depolarization current (TSDC) setup

    Science.gov (United States)

    Jain, Deepti; Sharath Chandra, L. S.; Nath, R.; Ganesan, V.

    2012-02-01

    We report here the design and implementation of a precise and easy to operate thermally stimulated depolarization current (TSDC) measurement setup for temperature range 77-400 K. The sample loading is made simple by sandwiching the sample between two copper disk electrodes using a spring-shaft arrangement. The salient features of the setup are precise thermal windowing (TW) capability and linear heating rate over the entire temperature range. The resolution in the measurement of depolarization current is of the order of 7×10-14 A. This is achieved by means of good electrical insulation of the electrodes from the rest of the setup and utilization of low noise circuitry. Precision of the system is demonstrated by its capability to resolve constituent relaxations present in complex relaxation processes using the TW experiments. Study and detection of glass transition processes in polyethylene terephthalate, four relaxation processes in polymethyl methacrylate, glass and crystallization transitions along with the onset of ferroelectric Curie transitions in polyvinylidene fluoride and characterization of electret state in amino acids l-arginine, phenylalanine, tyrosine, tryptophan, glutamic acid, glutamine and methionine show the versatility of our setup.

  19. Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk

    Science.gov (United States)

    Debes, John H.; Poteet, Charles A.; Jang-Condell, Hannah; Gaspar, Andras; Hines, Dean; Kastner, Joel H.; Pueyo, Laurent; Rapson, Valerie; Roberge, Aki; Schneider, Glenn; hide

    2017-01-01

    We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HSTSTIS observations achieved an inner working angle of approximately 0 "2, or11.7 au, probing the system at angular radii coincident with recent images of the disk obtained by ALMA and in polarized intensity near-infrared light. By comparing our new STIS images to those taken with STIS in 2000 and with NICMOS in 1998, 2004, and 2005, we demonstrate that TW Hyas azimuthal surface brightness asymmetry moves coherently in position angle. Between 50 au and 141 au we measure a constant angular velocity in the azimuthal brightness asymmetry of 22.deg7 yr(exp -1) in a counterclockwise direction, equivalent to a period of 15.9yrassuming circular motion. Both the (short) inferred period and lack of radial dependence of the moving shadow pattern are inconsistent with Keplerian rotation at these disk radii. We hypothesize that the asymmetry arises from the fact that the disk interior to 1 au is inclined and precessing owing to a planetary companion, thus partially shadowing the outer disk. Further monitoring of this and other shadows on protoplanetary disks potentially opens anew avenue for indirectly observing the sites of planet formation.

  20. Laser Imaging Systems For Computer Vision

    Science.gov (United States)

    Vlad, Ionel V.; Ionescu-Pallas, Nicholas; Popa, Dragos; Apostol, Ileana; Vlad, Adriana; Capatina, V.

    1989-05-01

    The computer vision is becoming an essential feature of the high level artificial intelligence. Laser imaging systems act as special kind of image preprocessors/converters enlarging the access of the computer "intelligence" to the inspection, analysis and decision in new "world" : nanometric, three-dimensionals(3D), ultrafast, hostile for humans etc. Considering that the heart of the problem is the matching of the optical methods and the compu-ter software , some of the most promising interferometric,projection and diffraction systems are reviewed with discussions of our present results and of their potential in the precise 3D computer vision.

  1. Aurora inertial confinement fusion laser control and data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, P.S.; Burczyk, L.; Dingler, R.D.; Shurter, R.B. (Los Alamos National Lab., P.O. Box 1663, AT-8 MS H811, Los Alamos, NM 87545)

    1987-05-01

    Aurora is a complex krypton fluoride excimer research laser supported by a computerized control and data acquisition system. Aurora's requirements for control, data aquisition, and data analysis are met with specific application of minicomputer and microcomputer capabilities coupled with internally developed custom hardware and software. A control system that provides an operator with the ability to charge and fire the integrated laser system safely and remotely is described. A data aquisition system that acquires, stores, and processes laser system data is also described. This data acquisition system provides the experimentalists with support tools for better understanding the laser system.

  2. In situ XFEL measurement system for Earth and planetary materials under laser-induced ultrahigh-pressure conditions

    Science.gov (United States)

    Tange, Y.; Ozaki, N.; Matsuoka, T.; Ogawa, T.; Albertazzi, B.; Habara, H.; Takahashi, K.; Matsuyama, S.; Yamauchi, K.; Tanaka, K.; Kodama, R.; Sato, T.; Sekine, T.; Seto, Y.; Okuchi, T.; Yabuuchi, T.; Inubushi, Y.; Yabashi, M.

    2015-12-01

    High-pressure and high-temperature in situ experiments have revealed behaviors of the earth and planetary constituents under extreme conditions, and contribute to progress our understandings about physical and chemical structure of planetary interiors. These in situ techniques have developed with the third-generation synchrotron radiation facilities such as APS, ESRF, and SPring-8 mainly using large volume presses and diamond anvil cells. In addition to the synchrotron light source, recently X-ray free electron laser (XFEL) facilities have been developed as LCLS and SACLA. The brilliant and extremely short-pulsed XFELs make it possible to carry out femto-second time-resolve measurements, and to observe materials under dynamic/shock compression clearly. Techniques using high-power laser and XFEL are expected to be a next-generation experimental platform, and a pump-probe measurement system using high-power lasers and XFEL was installed at BL3EH5 in SPring-8/SACLA interoperable experimental facility. The system is composed of 45 TW X-ray focusing system (KB mirrors), vacuumed sample chamber, and the MPCCD detector developed for the 10-fs ultra-short pulsed XFEL light source. The high-power laser enables us to generate up to 100 GPa for metal, simple oxide, and natural/synthesized mineral samples. Samples are mounted on sample holders and aligned at the center of the vacuum chamber using a 4-axis Goniometer head. In this presentation, we will overview the experimental setups and typical results of current pump-probe system using XFEL in SACLA.

  3. Design of nanosecond pulse laser micromachining system based on PMAC

    Science.gov (United States)

    Liu, Mingyan; Fu, Xing; Xu, Linyan; Lin, Qian; Gu, Shuang

    2012-10-01

    Pulse laser micromachining technology, as a branch of laser processing technology, has been widely used in MEMS device processing, aviation, instruments fabrication, circuit board design etc.. In this paper, a novel nanosecond pulse laser micromachining system is presented, which consists of nanosecond pulse LASER, optical path mechanical structure, transmission system, motion control system. Nanosecond pulse UV laser, with 355 nm wavelength and 40ns pulse width, is chosen as the light source. Optical path mechanical structure is designed to get ideal result of laser focusing. Motion control system, combining PMAC card with the PC software, can control the 3-D motion platform and complete microstructure processing. By CCD monitoring system, researchers can get real-time detection on the effect of laser beam focusing and processing process.

  4. Manufacturing of lasers for DWDM systems

    Science.gov (United States)

    Campbell, Kevin T.; Robertson, Alexander J., Jr.; Wetzel, Steven J.

    1999-11-01

    The evolution of dense wavelength division multiplexing (DWDM) has allowed service provides a convenient and cost effective method to dramatically increase transmission capacity over existing and new fiber network systems. As the demand for bandwidth continues to increase, systems designers are responding by increasing both the number of channels and the data rates. This trend has placed considerable pressure on many of the underlying system components. One component that has been particularly challenged by this trend is the manufacture of semiconductor lasers. This paper reviews the technical and logistical challenges faced in the high volume manufacture of lasers to support DWDM systems. As the product portfolio continues to expand, precise execution and team work among multiple organizations is required to assure reliable shipping performance. Production scheduling and manufacturing operations must work closely to continuously re-prioritize the work in process in response to constantly changing channel demand and yield fluctuations. Wavelength prediction models must be developed that correlate in-process parameters to final device wavelength. These models are then applied to both in-process specification targeting and inventory management. Once the in-process specifications are properly targeted, the challenge moves to the fabrication processes, where processes are pushed to the limits of their control. Underpinning the entire effort must be an information management system in which parametric data is collected, wavelength prediction models are executed, and work in process inventory is controlled with respect to the final output volume and wavelength distribution.

  5. Influences of weather phenomena on automotive laser radar systems

    Science.gov (United States)

    Rasshofer, R. H.; Spies, M.; Spies, H.

    2011-07-01

    Laser radar (lidar) sensors provide outstanding angular resolution along with highly accurate range measurements and thus they were proposed as a part of a high performance perception system for advanced driver assistant functions. Based on optical signal transmission and reception, laser radar systems are influenced by weather phenomena. This work provides an overview on the different physical principles responsible for laser radar signal disturbance and theoretical investigations for estimation of their influence. Finally, the transmission models are applied for signal generation in a newly developed laser radar target simulator providing - to our knowledge - worldwide first HIL test capability for automotive laser radar systems.

  6. In-vitro laser anemometry blood flow systems

    Science.gov (United States)

    Liepsch, Dieter W.; Poll, Axel; Pflugbeil, Gottlieb

    1993-08-01

    Lasers are used in a wide variety of medical applications. While laser catheters have been developed for highly accurate velocity measurements these are invasive; noninvasive techniques are more desirable but not as precise. The laser is, however, a great tool for in vitro measurements. Several groups internationally are using the laser in the study of local velocity distribution in microscopic areas of specially constructed models. Laser Doppler anemometry is widely used to measure the local, time-dependent velocities, while phase Doppler anemometry has been developed to measure particle size, distribution and velocity. Most recently, laser analyzer techniques have been developed for analyzing the particle size of two phase flow systems. It has become increasingly important for physicians to visualize blood flow. In addition to the techniques mentioned above, several laser sheet techniques have been developed for precise measurements. This paper presents a short review of laser techniques and shows some applications especially for the laser-Doppler anemometer.

  7. Predicting Complex Organic Molecule Emission from TW Hya

    Science.gov (United States)

    Vissapragada, Shreyas; Walsh, Catherine

    2017-01-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) has significantly increased our ability to observe the rich chemical inventory of star and planet formation. ALMA has recently been used to detect CH3OH (methanol) and CH3CN (methyl cyanide) in protoplanetary disks; these molecules may be vital indicators of the complex organic ice reservoir in the comet-forming zone. We have constructed a physiochemical model of TW Hya, a well-studied protoplanetary disk, to explore the different formation mechanisms of complex ices. By running our model through a radiative transfer code and convolving with beam sizes appropriate for ALMA, we have obtained synthetic observations of methanol and methyl cyanide. Here, we compare and comment on these synthetic observations, and provide astrochemical justification for their spatial distributions.

  8. Numerical simulation of a laser-acoustic landmine detection system

    Science.gov (United States)

    Lancranjan, Ion I.; Miclos, Sorin; Savastru, Dan; Savastru, Roxana; Opran, Constantin

    2012-06-01

    The preliminary numerical simulation results obtained in the analysis of a landmine detection system based on laser excitation of acoustic - seismic waves in the soil and observing its surface vibration above the embedded landmine are presented. The presented numerical simulations comprise three main parts: 1) Laser oscillator and laser beam propagation and absorption in soil; a laser oscillator operated in Q-switched regime is considered; different laser wavelengths are investigated. 2) Acoustic - seismic wave generation by absorption in soil of laser pulse energy; 3) Evaluation of acoustic - seismic wave generation by the buried in soil landmine; 4) Comparison of Distributed Feed- Back Fiber Laser (DFB-FL) and Laser Doppler Vibrometer (LDV) detector used for soil vibrations evaluation. The above mentioned numerical simulation is dedicated for evaluation of an integrated portable detection system.

  9. Development of a US Gravitational Wave Laser System for LISA

    Science.gov (United States)

    Camp, Jordan B.; Numata, Kenji

    2015-01-01

    A highly stable and robust laser system is a key component of the space-based LISA mission architecture.In this talk I will describe our plans to demonstrate a TRL 5 LISA laser system at Goddard Space Flight Center by 2016.The laser system includes a low-noise oscillator followed by a power amplifier. The oscillator is a low-mass, compact 10mW External Cavity Laser, consisting of a semiconductor laser coupled to an optical cavity, built by the laser vendorRedfern Integrated Optics. The amplifier is a diode-pumped Yb fiber with 2W output, built at Goddard. I will show noiseand reliability data for the full laser system, and describe our plans to reach TRL 5 by 2016.

  10. 骨龄评价方法TW3-RUS、TW3-C carpal、RUS-CHN对比及可重复性分析%Comparing and Analysizing the Repeatability of Assessing Skeletal Age by TW3-RUS,TW3-C carpal and RUS-CHN

    Institute of Scientific and Technical Information of China (English)

    冯红梅; 洪居陆; 何耀强; 杨冠英; 朱彬; 高明勇; 包相华

    2015-01-01

    目的:探讨TW3-RUS、TW3-C carpal、RUS-CHN三种骨龄评价方法的差异性及可重复性.材料与方法:应用TW3-RUS、TW3-C carpal、RUS-CHN三种方法,由2名有骨龄评价培训经历的医师,阅读时间年龄为12岁的正常男性儿童的手腕部X线平片,独立盲法进行骨龄评价.结果:2名医师的骨龄评价结果差别无统计学差异(P>0.05);3种方法对骨龄评价结果的差别有统计学意义(P<0.05);2人组内3种方法两两比较,TW3-Ccarpal与TW3-RUS及RUS-CHN骨龄评价结果的差别有统计学意义(P<0.05),TW3-RUS与RUS-CHN骨龄评价结果的差别无统计学意义(P>0.05).结论:2名医师应用3种方法对12岁男童骨龄评价结果的可重复性高.对12岁男童骨龄评价,TW3-RUS与RUS-CHN法无明显差别,TW3-C carpal与TW3-RUS及RUS-CHN差别较大,推测TW3-C carpal可能不适合12岁男童骨龄评价.

  11. High Speed Laser 3D Measurement System

    Institute of Scientific and Technical Information of China (English)

    SONG Yuan-he; FAN Chang-zhou; GUO Ying; LI Hong-wei; ZHAO Hong

    2003-01-01

    Using the method of line structure light produced by a laser diode,three dimensional profile measurement is deeply researched.A hardware circuit developed is used to get the center position of light section for the improvement of the measurement speed.A double CCD compensation technology is used to improve the measurement precision. An easy and effective calibration method of the least squares to fit the parameter of system structure is used to get the relative coordinate relationship of objects and images of light section in the directions of height and axis. Sensor scanning segment by segment and layer by layer makes the measurement range expand greatly.

  12. Laser and optical system for laser assisted hydrogen ion beam stripping at SNS

    Science.gov (United States)

    Liu, Y.; Rakhman, A.; Menshov, A.; Webster, A.; Gorlov, T.; Aleksandrov, A.; Cousineau, S.

    2017-03-01

    Recently, a high-efficiency laser assisted hydrogen ion (H-) beam stripping was successfully carried out in the Spallation Neutron Source (SNS) accelerator. The experiment was not only an important step toward foil-less H- stripping for charge exchange injection, it also set up a first example of using megawatt ultraviolet (UV) laser source in an operational high power proton accelerator facility. This paper reports in detail the design, installation, and commissioning result of a macro-pulsed multi-megawatt UV laser system and laser beam transport line for the laser stripping experiment.

  13. High power laser downhole cutting tools and systems

    Energy Technology Data Exchange (ETDEWEB)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  14. 76 FR 1149 - T.W. Phillips Pipeline Corp.; Notice of Filing

    Science.gov (United States)

    2011-01-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission T.W. Phillips Pipeline Corp.; Notice of Filing December 30, 2010. Take notice that on December 17, 2010, T.W. Phillips Pipeline Corp. submitted a request for a waiver of...

  15. Cleaning space debris with a space-based laser system

    Institute of Scientific and Technical Information of China (English)

    Shen Shuangyan; Jin Xing; Chang Hao

    2014-01-01

    High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1-10 cm. Under laser irradiation, part of the debris material is ablated and provides an impulse to the debris particle. Proper direction of the impulse vector either deflects the object trajectory or forces the debris on a trajectory through the upper atmosphere, where it burns up. Most research concentrates on ground-based laser systems but pays little attention to space-based laser systems. There are drawbacks of a ground-based laser system in cleaning space debris. Therefore the placement of a laser system in space is proposed and investigated. Under assumed conditions, the elimination process of space debris is analyzed. Several factors such as laser repetition frequency, relative movement between the laser and debris, and inclination of debris particles which may exercise influence to the elimination effects are discussed. A project of a space-based laser system is proposed according to the numerical results of a computer study. The proposed laser system can eliminate debris of 1-10 cm and succeed in protecting a space station.

  16. Compact excimer laser light source for optical (mask) inspection systems

    Science.gov (United States)

    Pflanz, Tobias; Huber, Heinz

    2001-04-01

    The discharge pumped excimer laser is a gas laser providing ultra violet radiation with well defined spectral, temporal and spatial properties. The fast development of excimer lasers in recent years has succeeded in designing very compact, turn-key systems delivering up to 10 W of radiation at 248 nm (5 W at 193 nm and 1 W at 157 nm) with repetition rates up to 1000 Hz. Experimental data on important beam properties of excimer lasers in the field of mask inspection are being presented and discussed. Relevant parameters are spectral bandwidth, energetic pulse-to-pulse stability, pulse duration, beam pointing stability, beam direction stability, beam dimension, beam profile and coherence. We will compare the excimer laser with lamp sources and continuous wave lasers in the framework of these parameters. The discussion will show future opportunities of compact excimer lasers in optical inspection as well as in mask writing systems, improving resolution and throughput.

  17. Narrow linewidth single laser source system for onboard atom interferometry

    CERN Document Server

    Theron, Fabien; Renon, Geoffrey; Bidel, Yannick; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2014-01-01

    We present an original compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser. Thanks to an original stabilization architecture on a saturated absorption, we obtain a frequency agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using only a single laser source. The different laser frequencies used for atom interferometry are created by changing dynamically the frequency of the laser and by creating sidebands using a phase modulator. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components, which are intrinsically less stable, and to make the setup compact, much less sensitive to vibrations and thermal fluctuations. This source provides spectral linewidth below 2.5 kHz required for precision atom interferometry, and particularly for an high performance atomic inertial sensor.

  18. Fiber laser system for cesium and rubidium atom interferometry

    CERN Document Server

    Diboune, Clément; Bidel, Yannick; Cadoret, Malo; Bresson, Alexandre

    2016-01-01

    We present an innovative fiber laser system for both cesium and rubidium manipulation. The architecture is based on frequency conversion of two lasers at 1560 nm and 1878 nm. By taking advantage of existing fiber components at these wavelengths, we demonstrate an all fiber laser system delivering 350 mW at 780 nm for rubidium and 210 mW at 852 nm for cesium. This result highlights the promising nature of such laser system especially for Cs manipulation for which no fiber laser system has been reported. It offers new perspectives for the development of atomic instruments dedicated to onboard applications and opens the way to a new generation of atom interferometers involving three atomic species $^{85}$Rb, $^{87}$Rb and $^{133}$Cs for which we propose an original laser architecture.

  19. Laser Spectroscopy Investigations of Materials for Solid State Laser Systems.

    Science.gov (United States)

    1988-02-01

    Experimental geometry for anisotropic self-diffraction expert. Permanent address: Departamento de Optics y Estructura de Is Materia, mints. e refers to the...the helium-neon laser and PMT is the photo- "Permanent address: Departamento de Optics y Estructura de Ia Materia, multiplier tube. The results are sent

  20. Blind guidance system based on laser triangulation

    Science.gov (United States)

    Wu, Jih-Huah; Wang, Jinner-Der; Fang, Wei; Lee, Yun-Parn; Shan, Yi-Chia; Kao, Hai-Ko; Ma, Shih-Hsin; Jiang, Joe-Air

    2012-05-01

    We propose a new guidance system for the blind. An optical triangulation method is used in the system. The main components of the proposed system comprise of a notebook computer, a camera, and two laser modules. The track image of the light beam on the ground or on the object is captured by the camera and then the image is sent to the notebook computer for further processing and analysis. Using a developed signal-processing algorithm, our system can determine the object width and the distance between the object and the blind person through the calculation of the light line positions on the image. A series of feasibility tests of the developed blind guidance system were conducted. The experimental results show that the distance between the test object and the blind can be measured with a standard deviation of less than 8.5% within the range of 40 and 130 cm, while the test object width can be measured with a standard deviation of less than 4.5% within the range of 40 and 130 cm. The application potential of the designed system to the blind guidance can be expected.

  1. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Directory of Open Access Journals (Sweden)

    Torbeck R

    2016-05-01

    Full Text Available Richard Torbeck,1 Richard Bankowski,2 Sarah Henize,3 Nazanin Saedi,11Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 2Cynosure, Inc, Westford, MA, 3Huron Consulting Group, Chicago, IL, USABackground and objectives: The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm. Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal.Study design and methods: A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal".Results: A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow. Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change.Conclusion: Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.Keywords: tattoo, removal, laser, picosecond 

  2. METHOD AND SYSTEM FOR LASER WELDING

    DEFF Research Database (Denmark)

    2008-01-01

    The invention relates to laser welding of at least two adjacent, abutting or overlapping work pieces in a welding direction using multiple laser beams guided to a welding region, wherein at least two of the multiple laser beams are coupled into the welding region so as to form a melt and at least...

  3. A novel diode laser system for photodynamic therapy

    DEFF Research Database (Denmark)

    Samsøe, E.; Andersen, P. E.; Petersen, P.;

    2001-01-01

    In this paper a novel diode laser system for photodynamic therapy is demonstrated. The system is based on linear spatial filtering and optical phase conjugate feedback from a photorefractive BaTiO3 crystal. The spatial coherence properties of the diode laser are significantly improved. The system...... is extracted in a high-quality beam and 80 percent of the output power is extracted through the fiber. The power transmitted through tile fiber scales linearly with the power of the laser diode. which means that a laser diode emitting 1.7 W multi-mode radiation would provide 1 W of optical power through a 50...

  4. Development of the power control system for semiconductor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Suk; Kim, Cheol Jung

    1997-12-01

    For the first year plan of this program, we developed the power control system for semiconductor lasers. We applied the high-current switching mode techniques to fabricating a power control system. Then, we investigated the direct side pumping techniques with GaA1As diode laser bars to laser crystal without pumping optics. We obtained 0.5W average output power from this DPSSL. (author). 54 refs., 3 tabs., 18 figs.

  5. Distance and Kinematics of the TW Hydrae Association from Parallaxes

    CERN Document Server

    Weinberger, Alycia J; Boss, Alan P

    2012-01-01

    From common proper motion and signatures of youth, researchers have identified about 30 members of a putative TW Hydrae Association. Only four of these had parallactic distances from Hipparcos. We have measured parallaxes and proper motions for 14 primary members. We combine these with literature values of radial velocities to show that the Galactic space motions of the stars, with the exception of TWA 9 and 22, are parallel and do not indicate convergence at a common formation point sometime in the last few million years. The space motions of TWA 9 and 22 do not agree with the others and indicate that they are not TWA members. The median parallax is 18 mas or 56 pc. We further analyze the stars' absolute magnitudes on pre-main sequence evolutionary tracks and find a range of ages with a median of 10.1 Myr and no correlation between age and Galactic location. The TWA stars may have formed from an extended and filamentary molecular cloud but are not necessarily precisely coeval.

  6. TW Hya: Spectral Variability, X-Rays, and Accretion Diagnostics

    CERN Document Server

    Dupree, A K; Cranmer, S R; Luna, G J M; Schneider, E E; Bessell, M S; Bonanos, A; Crause, L A; Lawson, W A; Mallik, S V; Schuler, S C

    2012-01-01

    The nearest accreting T Tauri star, TW Hya was observed with spectroscopic and photometric measurements simultaneous with a long se gmented exposure using the CHANDRA satellite. Contemporaneous optical photometry from WASP-S indicates a 4.74 day period was present during this time. Absence of a similar periodicity in the H-alpha flux and the total X-ray flux points to a different source of photometric variations. The H-alpha emission line appears intrinsically broad and symmetric, and both the profile and its variability suggest an origin in the post-shock cooling region. An accretion event, signaled by soft X-rays, is traced spectroscopically for the first time through the optical emission line profiles. After the accretion event, downflowing turbulent material observed in the H-alpha and H-beta lines is followed by He I (5876A) broadening. Optical veiling increases with a delay of about 2 hours after the X-ray accretion event. The response of the stellar coronal emission to an increase in the veiling follow...

  7. On the structure of the transition disk around TW Hya

    CERN Document Server

    Menu, J; Henning, T; Chandler, C J; Linz, H; Benisty, M; Lacour, S; Min, M; Waelkens, C; Andrews, S M; Calvet, N; Carpenter, J M; Corder, S A; Deller, A T; Greaves, J S; Harris, R J; Isella, A; Kwon, W; Lazio, J; Bouquin, J -B Le; Ménard, F; Mundy, L G; Pérez, L M; Ricci, L; Sargent, A I; Storm, S; Testi, L; Wilner, D J

    2014-01-01

    For over a decade, the structure of the inner cavity in the transition disk of TW Hydrae has been a subject of debate. Modeling the disk with data obtained at different wavelengths has led to a variety of proposed disk structures. Rather than being inconsistent, the individual models might point to the different faces of physical processes going on in disks, such as dust growth and planet formation. Our aim is to investigate the structure of the transition disk again and to find to what extent we can reconcile apparent model differences. A large set of high-angular-resolution data was collected from near-infrared to centimeter wavelengths. We investigated the existing disk models and established a new self-consistent radiative-transfer model. A genetic fitting algorithm was used to automatize the parameter fitting. Simple disk models with a vertical inner rim and a radially homogeneous dust composition from small to large grains cannot reproduce the combined data set. Two modifications are applied to this sim...

  8. Volatile depletion in the TW Hydrae disk atmosphere

    CERN Document Server

    Du, Fujun; Hogerheijde, Michiel R

    2015-01-01

    An abundance decrease in carbon- and oxygen-bearing species relative to dust has been frequently found in planet-forming disks, which can be attributed to an overall reduction of gas mass. However, in the case of TW Hya, the only disk with gas mass measured directly with HD rotational lines, the inferred gas mass ($\\lesssim$0.005 solar mass) is significantly below the directly measured value ($\\gtrsim$0.05 solar mass). We show that this apparent conflict can be resolved if the elemental abundances of carbon and oxygen are reduced in the upper layers of the outer disk but are normal elsewhere (except for a possible enhancement of their abundances in the inner disk). The implication is that in the outer disk, the main reservoir of the volatiles (CO, water, ...) resides close to the midplane, locked up inside solid bodies that are too heavy to be transported back to the atmosphere by turbulence. An enhancement in the carbon and oxygen abundances in the inner disk can be caused by inward migration of these solid ...

  9. Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk

    Science.gov (United States)

    Debes, John H.; Poteet, Charles A.; Jang-Condell, Hannah; Gaspar, Andras; Hines, Dean; Kastner, Joel H.; Pueyo, Laurent; Rapson, Valerie; Roberge, Aki; Schneider, Glenn; Weinberger, Alycia J.

    2017-02-01

    We have obtained new images of the protoplanetary disk orbiting TW Hya in visible, total intensity light with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST), using the newly commissioned BAR5 occulter. These HST/STIS observations achieved an inner working angle of ∼0.″2, or 11.7 au, probing the system at angular radii coincident with recent images of the disk obtained by ALMA and in polarized intensity near-infrared light. By comparing our new STIS images to those taken with STIS in 2000 and with NICMOS in 1998, 2004, and 2005, we demonstrate that TW Hya’s azimuthal surface brightness asymmetry moves coherently in position angle. Between 50 au and 141 au we measure a constant angular velocity in the azimuthal brightness asymmetry of 22.°7 yr‑1 in a counterclockwise direction, equivalent to a period of 15.9 yr assuming circular motion. Both the (short) inferred period and lack of radial dependence of the moving shadow pattern are inconsistent with Keplerian rotation at these disk radii. We hypothesize that the asymmetry arises from the fact that the disk interior to 1 au is inclined and precessing owing to a planetary companion, thus partially shadowing the outer disk. Further monitoring of this and other shadows on protoplanetary disks potentially opens a new avenue for indirectly observing the sites of planet formation. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  10. Design of high-precision ranging system for laser fuze

    Science.gov (United States)

    Chen, Shanshan; Zhang, He; Xu, Xiaobin

    2016-10-01

    According to the problem of the high-precision ranging in the circumferential scanning probe laser proximity fuze, a new type of pulsed laser ranging system has been designed. The laser transmitting module, laser receiving module and ranging processing module have been designed respectively. The factors affecting the ranging accuracy are discussed. And the method of improving the ranging accuracy is studied. The high-precision ranging system adopts the general high performance microprocessor C8051FXXX as the core. And the time interval measurement chip TDC-GP21 was used to implement the system. A PCB circuit board was processed to carry on the experiment. The results of the experiment prove that a centimeter level accuracy ranging system has been achieved. The works can offer reference for ranging system design of the circumferential scanning probe laser proximity fuze.

  11. A semiconductor laser system for the production of antihydrogen

    CERN Document Server

    Mullers, A; Kolbe, D; Diehl, T; Koglbauer, A; Sattler, M; Stappel, M; Steinborn, R; Walz, J; Gabrielse, G; Kalra, R; Kolthammer, W S; McConnell, R P; Richerme, P; Fitzakerley, D W; George, M C; Hessels, E A; Storry, C H; Weel, M; Grzonka, D; Oelert, W

    2012-01-01

    Laser-controlled charge exchange is a promising method for producing cold antihydrogen. Caesium atoms in Rydberg states collide with positrons and create positronium. These positronium atoms then interact with antiprotons, forming antihydrogen. Laser excitation of the caesium atoms is essential to increase the cross section of the charge-exchange collisions. This method was demonstrated in 2004 by the ATRAP collaboration by using an available copper vapour laser. For a second generation of charge-exchange experiments we have designed a new semiconductor laser system that features several improvements compared to the copper vapour laser. We describe this new laser system and show the results from the excitation of caesium atoms to Rydberg states within the strong magnetic fields in the ATRAP apparatus.

  12. Prompt pre-thermal laser ion sheath acceleration with ultra-short laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Zeil, Karl; Bussmann, Michael; Cowan, Thomas; Kluge, Thomas; Kraft, Stephan; Metzkes, Josefine; Schramm, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf (Germany)

    2013-07-01

    Recent laser-ion acceleration experiments performed at the 150 TW Draco laser in Dresden, Germany, have demonstrated the importance of a precise understanding of the electron dynamics in solids on an ultra-short time scale. For example, with ultra-short laser pulses a description based purely on the evolution of a thermal electron ensemble, as in standard TNSA models, is not sufficient anymore. Rather, non-thermal effects during the ultra-short intra-pulse phase of laser-electron interaction in solids become important for the acceleration of ions when the laser pulse duration is in the order of only a few tens of femtoseconds. While the established maximum ion energy scaling in the TNSA regime goes with the square root of the laser intensity, for such ultra short pulse durations the maximum ion energy is found to scale linear with laser intensity, motivating the interest in such laser systems. Investigating the influence of laser pulse contrast, laser polarization and laser incidence angle on the proton maximum energy and angular distribution, we present recent advances in the description of the laser interaction with solids, focusing on the implications of intra-pulse non-thermal phenomena on the ion acceleration.

  13. Development of laser-based imaging systems for medical diagnostics

    Science.gov (United States)

    Witte, S.; Salumbides, M.; Peterman, E. J. G.; Brakenhoff, R.; van Dongen, G.; Toonen, R.; Mansvelder, H. D.; Groot, M. L.

    We present a laser system with high wavelength flexibility, suitable for nonlinear microscopy and optical coherence tomography, for visualization of disease-related morphological changes in vivo. A single-shot 2D OCT system is demonstrated.

  14. Revisiting TW Hydrae in light of new astrometric data

    Science.gov (United States)

    Teixeira, R.; Ducourant, C.; Galli, P. A. B.; Le Campion, J. F.; Zuckerman, B.; Krone-Martins, A. G. O.; Chauvin, G.; Song, I.

    2014-10-01

    Our efforts in the present work focused mainly on refining and improving the previous description and understanding of the stellar association TW Hydrae (TWA) including a very detailed membership analysis and its dynamical and evolutionary age.To achieve our objectives in a fully reliable way we take advantage of our own astrometric measurements (Ducourant et al. 2013) performed with NTT/EFOSC2 - ESO (La Silla - Chile) spread over three years (2007 - 2010) and of those published in the literature.A very detailed membership analysis based on the convergent point strategy as developed by our team (Galli et al. 2012, 2013) allowed us to define a consistent kinematic group containing 31 stars among the 44 proposed as TWA member in the literature. Assuming that our sample of stars may be contaminated by non-members and to get rid of the particular influence of each star we applied a Jacknife resampling technique generating 2000 random lists of 13 stars taken from our 16 stars and calculated for each the epoch of convergence when the radius is minimum. The mean of the epochs obtained and the dispersion about the mean give a dynamical age of 7.5± 0.7 Myr for the association that is in good agreement with the previous traceback age (De La Reza et al. 2006). We also estimated age for TWA moving group members from pre-main sequence evolutionary models (Siess et al. 2000) and find a mean age of 7.4± 1.2 Myr. These results show that the dynamical age of the association obtained via the traceback technique and the average age derived from theoretical evolutionary models are in good agreement.

  15. System, Apparatus and Method Employing a Dual Head Laser

    Science.gov (United States)

    Coyle, Donald B. (Inventor); Stysley, Paul R. (Inventor); Poulios, Demetrios (Inventor)

    2015-01-01

    A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.

  16. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    Background and objectives The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal. Study design and methods A PubMed search was conducted using the term “picosecond” combined with “laser”, “dermatology”, and “laser tattoo removal”. Results A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Conclusion Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments. PMID:27194919

  17. Measurement of stability of electron beam generated by laser-driven plasma-based accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, S; Miura, E; Koyama, K; Kato, S [National Institute of Advanced Industrial Science and Technology, Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)], E-mail: shi-masuda@aist.go.jp

    2008-05-01

    Quasi-monoenergetic electron beams with the energy of 30-80 MeV and large number of electrons more than 10{sup 8} were produced by focusing a 8TW, 50 fs Ti:sapphire laser pulse onto 1.6-1.9 x 10{sup 19} cm{sup -3} plasmas. Stability of the quasi-monoenergetic electron beam generation was evaluated using an in-situ observation system for the electron beam diagnostics.

  18. Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-04-24

    A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

  19. Laser metrology in food-related systems

    Science.gov (United States)

    Mendoza-Sanchez, Patricia; Lopez, Daniel; Kongraksawech, Teepakorn; Vazquez, Pedro; Torres, J. Antonio; Ramirez, Jose A.; Huerta-Ruelas, Jorge

    2005-02-01

    An optical system was developed using a low-cost semiconductor laser and commercial optical and electronic components, to monitor food processes by measuring changes in optical rotation (OR) of chiral compounds. The OR signal as a function of processing time and sample temperature were collected and recorded using a computer data acquisition system. System has been tested during two different processes: sugar-protein interaction and, beer fermentation process. To study sugar-protein interaction, the following sugars were used: sorbitol, trehalose and sucrose, and in the place of Protein, Serum Albumin Bovine (BSA, A-7906 Sigma-Aldrich). In some food processes, different sugars are added to protect damage of proteins during their processing, storage and/or distribution. Different sugar/protein solutions were prepared and heated above critical temperature of protein denaturation. OR measurements were performed during heating process and effect of different sugars in protein denaturation was measured. Higher sensitivity of these measurements was found compared with Differential Scanning Calorimetry, which needs higher protein concentration to study these interactions. The brewing fermentation process was monitored in-situ using this OR system and validated by correlation with specific density measurements and gas chromatography. This instrument can be implemented to monitor fermentation on-line, thereby determining end of process and optimizing process conditions in an industrial setting. The high sensitivity of developed OR system has no mobile parts and is more flexible than commercial polarimeters providing the capability of implementation in harsh environments, signifying the potential of this method as an in-line technique for quality control in food processing and for experimentation with optically active solutions.

  20. Narrow linewidth single laser source system for onboard atom interferometry

    Science.gov (United States)

    Theron, Fabien; Carraz, Olivier; Renon, Geoffrey; Zahzam, Nassim; Bidel, Yannick; Cadoret, Malo; Bresson, Alexandre

    2015-01-01

    A compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser is presented. Thanks to the original stabilization architecture on a saturated absorption setup, we obtain a frequency agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using a single laser source. The different laser frequencies used for atom interferometry are generated by changing dynamically the frequency of the laser and by creating sidebands using a phase modulator. A laser system for Rubidium 87 atom interferometry using only one laser source based on a frequency-doubled telecom fiber bench is then built. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components (which are intrinsically less stable) and to make the setup compact and much less sensitive to vibrations and thermal fluctuations. This source provides spectral linewidth below 2.5 kHz, which is required for precision atom interferometry and particularly for a high performance atomic inertial sensor.

  1. Operation of the APS photoinjector drive laser system.

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Accelerator Systems Division (APS)

    2008-08-04

    The APS photoinjector drive laser system has been in operation since 1999 and is achieving a performance level exceeding the requirement of stable operation of the LEUTL FEL system. One remarkable number is the UV energy stability of better than 2% rms, sometimes less than 1% rms. This report summarizes the operation experience of the laser system and the improvements made along the way. We also outline the route of upgrade of the system and some frontier laser research and development opportunities in ultrabright electron beam generation.

  2. Dual-beam laser autofocusing system based on liquid lens

    Science.gov (United States)

    Zhang, Fumin; Yao, Yannan; Qu, Xinghua; Zhang, Tong; Pei, Bing

    2017-02-01

    A dual-beam laser autofocusing system is designed in this paper. The autofocusing system is based on a liquid lens with less moving parts and fast response time, which makes the system simple, reliable, compact and fast. A novel scheme "Time-sharing focus, fast conversion" is innovatively proposed. The scheme effectively solves the problem that the guiding laser and the working laser cannot focus at the same target point because of the existence of chromatic aberration. This scheme not only makes both guiding laser and working laser achieve optimal focusing in guiding stage and working stage respectively, but also greatly reduces the system complexity and simplifies the focusing process as well as makes autofocusing time of the working laser reduce to about 10 ms. In the distance range of 1 m to 30 m, the autofocusing spot size is kept under 4.3 mm at 30 m and just 0.18 mm at 1 m. The spot size is much less influenced by the target distance compared with the collimated laser with a micro divergence angle for its self-adaptivity. The dual-beam laser autofocusing system based on liquid lens is fully automatic, compact and efficient. It is fully meet the need of dynamicity and adaptivity and it will play an important role in a number of long-range control applications.

  3. Updated laser safety & hazard analysis for the ARES laser system based on the 2007 ANSI Z136.1 standard.

    Energy Technology Data Exchange (ETDEWEB)

    Augustoni, Arnold L.

    2007-08-01

    A laser safety and hazard analysis was performed for the temperature stabilized Big Sky Laser Technology (BSLT) laser central to the ARES system based on the 2007 version of the American National Standards Institutes (ANSI) Standard Z136.1, for Safe Use of Lasers and the 2005 version of the ANSI Standard Z136.6, for Safe Use of Lasers Outdoors. The ARES laser system is a Van/Truck based mobile platform, which is used to perform laser interaction experiments and tests at various national test sites.

  4. Laser Beam Duct Pressure Controller System.

    Science.gov (United States)

    the axial flow of a conditioning gas within the laser beam duct, by matching the time rate of change of the pressure of the flowing conditioning gas...to the time rate of change of the pressure in the cavity of an operably associated laser beam turret.

  5. Precise Measurement of Laser Power using an Optomechanical System

    CERN Document Server

    Agatsuma, Kazuhiro; Ballmer, Stefan; DeSalvo, Giulia; Sakata, Shihori; Nishida, Erina; Kawamura, Seiji

    2014-01-01

    This paper shows a novel method to precisely measure the laser power using an optomechanical system. By measuring a mirror displacement caused by the reflection of an amplitude modulated laser beam, the number of photons in the incident continuous-wave laser can be precisely measured. We have demonstrated this principle by means of a prototype experiment uses a suspended 25 mg mirror as an mechanical oscillator coupled with the radiation pressure and a Michelson interferometer as the displacement sensor. A measurement of the laser power with an uncertainty of less than one percent (1 sigma) is achievable.

  6. Laser photovoltaic power system synergy for SEI applications

    Science.gov (United States)

    Landis, Geoffrey A.; Hickman, J. M.

    1991-01-01

    Solar arrays can provide reliable space power, but do not operate when there is no solar energy. Photovoltaic arrays can also convert laser energy with high efficiency. One proposal to reduce the required mass of energy storage required is to illuminate the photovoltaic arrays by a ground laser system. It is proposed to locate large lasers on cloud-free sites at one or more ground locations, and use large lenses or mirrors with adaptive optical correction to reduce the beam spread due to diffraction or atmospheric turbulence. During the eclipse periods or lunar night, the lasers illuminate the solar arrays to a level sufficient to provide operating power.

  7. Development of 100W class blue direct diode laser coating system for laser metal deposition

    Science.gov (United States)

    Higashino, R.; Tsukamoto, M.; Sato, Y.; Abe, N.; Asano, K.; Funada, Y.

    2017-02-01

    Laser cladding technique is widely used for industrial application such as oil, energy industry, and aircraft and so on because it is able to repair and to form a near net shape. This process have been employed infrared lasers with wavelength of 0.8-10.6μm since output power of these lasers have over 1000W. Metal processing efficiency was, however, low in these wavelength, because the absorption was low. Thus, we developed the laser cladding system with blue direct diode laser at the wavelength of 445nm. 6 blue diode lasers was combined on the focusing spot to reach the output power of 100W by a lens, which one blue diode laser module was maximum output power of 20W. By using this laser cladding system, a pure copper film coating on a SUS304 stainless steel plate was demonstrated from a copper powder. As the result, the copper layer was formed on SUS304 stainless steel plate at the width of 322μm and thickness of 534μm was formed on the substrate.

  8. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO 2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  9. Direct acceleration of electrons by a CO$_{2}$ laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO$_{2}$ laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread ($\\sim1\\%$) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO$_{2}$ laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  10. Laser cutting of irregular shape object based on stereo vision laser galvanometric scanning system

    Science.gov (United States)

    Qi, Li; Zhang, Yixin; Wang, Shun; Tang, Zhiqiang; Yang, Huan; Zhang, Xuping

    2015-05-01

    Irregular shape objects with different 3-dimensional (3D) appearances are difficult to be shaped into customized uniform pattern by current laser machining approaches. A laser galvanometric scanning system (LGS) could be a potential candidate since it can easily achieve path-adjustable laser shaping. However, without knowing the actual 3D topography of the object, the processing result may still suffer from 3D shape distortion. It is desirable to have a versatile auxiliary tool that is capable of generating 3D-adjusted laser processing path by measuring the 3D geometry of those irregular shape objects. This paper proposed the stereo vision laser galvanometric scanning system (SLGS), which takes the advantages of both the stereo vision solution and conventional LGS system. The 3D geometry of the object obtained by the stereo cameras is used to guide the scanning galvanometers for 3D-shape-adjusted laser processing. In order to achieve precise visual-servoed laser fabrication, these two independent components are integrated through a system calibration method using plastic thin film target. The flexibility of SLGS has been experimentally demonstrated by cutting duck feathers for badminton shuttle manufacture.

  11. DFB fiber laser as source for optical communication systems

    DEFF Research Database (Denmark)

    Varming, Poul; Hübner, Jörg; Kristensen, Martin

    1997-01-01

    The results demonstrate that DFB fiber lasers are an attractive alternative as sources in telecommunication systems. The lasers show excellent long-term stability with very high signal to noise ratio and a reasonable output power, combined with exceptional temperature stability and inherent fiber...

  12. Shipborne Laser Beam Weapon System for Defence against Cruise Missiles

    Directory of Open Access Journals (Sweden)

    J.P. Dudeja

    2000-04-01

    Full Text Available Sea-skim~ing cruise missiles pose the greatest threat to a surface ship in the present-day war scenario. The convenitional close-in-weapon-systems (CIWSs are becoming less reliable against these new challenges requiring extremely fast reaction time. Naval Forces see a high energy laser as a feasible andjeffective directed energy weapon against sea-skimming antiship cruise missiles becauseof its .ability to deliver destructive energy at the speed of light on to a distant target. The paper comparesthe technology and capability of deuterium fluoride (DF and chemical-oxygen-iodine laser (COIL in effectively performing the role of a shipborne CIWS altainst sea-skimming missiles. Out of these twolasers, it is argued that DF laser wo.uld be more effective a,s a shipborne weapon for defence against sea-skimmin,g cruise missiles. Besides the high energy laser as the primary (killing laser, othersub-systems required in the complete weapon system would be: A beacon laser to sense phase distor'ions in the primary laser, adaptive optics to compensate the atmospheric distortions, beam-directing optics, illuminating lasers, IRST sensors, surveillance and tracking radars, interfacing system, etc.

  13. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

    conveyor belts fully controlled by a Siemens PLC controller (programmable logic controller), a stereo vision system consisting of two cameras, a 2-axis laser beam deflection unit and a laser source. The main challenge in this project was to accurately estimate and reconstruct the weed growth center using...

  14. The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog

    CERN Document Server

    Kellogg, Kendra; Gagne, Jonathan; Faherty, Jacqueline

    2016-01-01

    In a recent search for unusually red L and T dwarfs, we identified 2MASS J11193254-1137466 as a likely young L7 dwarf and potential member of the TW Hydrae association. We present spectra that confirm the youth of this object. We also measure a radial velocity of 8.5 +/- 3.3 km/s that, together with the sky position, proper motion and photometric distance, results in a 92% probability of membership in the TW Hydrae association, with a calibrated field contamination probability of 0.0005% using the BANYAN II tool. Using the age of TW Hydrae and the luminosity of 2MASS J11193254-1137466, we estimate its mass to be 4.3--7.6 MJup. It is the lowest-mass and nearest isolated member of TW Hydrae at a kinematic distance of 28.9 +/- 3.6 pc, and the second-brightest isolated <10 MJup object discovered to date.

  15. Coherent Laser Radar Metrology System for Large Scale Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of laser radar metrology inspection system is proposed that incorporates a novel, dual laser coherent detection scheme capable of eliminating both...

  16. Coherent Laser Radar Metrology System for Large Scale Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of laser radar metrology inspection system is proposed that incorporates a novel, dual laser coherent detection scheme capable of eliminating both...

  17. Measuring turbulence in TW Hydrae with ALMA: methods and limitations

    Science.gov (United States)

    Teague, R.; Guilloteau, S.; Semenov, D.; Henning, Th.; Dutrey, A.; Piétu, V.; Birnstiel, T.; Chapillon, E.; Hollenbach, D.; Gorti, U.

    2016-07-01

    Aims: We aim to obtain a spatially resolved measurement of velocity dispersions in the disk of TW Hya. Methods: We obtained images with high spatial and spectral resolution of the CO J = 2-1, CN N = 2-1 and CS J = 5-4 emission with ALMA in Cycle 2. The radial distribution of the turbulent broadening was derived with two direct methods and one modelling approach. The first method requires a single transition and derives Tex directly from the line profile, yielding a vturb. The second method assumes that two different molecules are co-spatial, which allows using their relative line widths for calculating Tkin and vturb. Finally we fitted a parametric disk model in which the physical properties of the disk are described by power laws, to compare our direct methods with previous values. Results: The two direct methods were limited to the outer r > 40 au disk because of beam smear. The direct method found vturb to range from ≈130 m s-1 at 40 au, and to drop to ≈50 m s-1 in the outer disk, which is qualitatively recovered with the parametric model fitting. This corresponds to roughly 0.2-0.4 cs. CN was found to exhibit strong non-local thermal equilibrium effects outside r ≈ 140 au, so that vturb was limited to within this radius. The assumption that CN and CS are co-spatial is consistent with observed line widths only within r ≲ 100 au, within which vturb was found to drop from 100 m s-1 (≈0.4 cs) to zero at 100 au. The parametric model yielded a nearly constant 50 m s-1 for CS (0.2-0.4 cs). We demonstrate that absolute flux calibration is and will be the limiting factor in all studies of turbulence using a single molecule. Conclusions: The magnitude of the dispersion is comparable with or below that predicted by the magneto-rotational instability theory. A more precise comparison would require reaching an absolute calibration precision of about 3%, or finding a suitable combination of light and heavy molecules that are co-located in the disk. The reduced

  18. Space-qualified laser system for the BepiColombo Laser Altimeter.

    Science.gov (United States)

    Kallenbach, Reinald; Murphy, Eamonn; Gramkow, Bodo; Rech, Markus; Weidlich, Kai; Leikert, Thomas; Henkelmann, Reiner; Trefzger, Boris; Metz, Bodo; Michaelis, Harald; Lingenauber, Kay; DelTogno, Simone; Behnke, Thomas; Thomas, Nicolas; Piazza, Daniele; Seiferlin, Karsten

    2013-12-20

    The space-qualified design of a miniaturized laser for pulsed operation at a wavelength of 1064 nm and at repetition rates up to 10 Hz is presented. This laser consists of a pair of diode-laser pumped, actively q-switched Nd:YAG rod oscillators hermetically sealed and encapsulated in an environment of dry synthetic air. The system delivers at least 300 million laser pulses with 50 mJ energy and 5 ns pulse width (FWHM). It will be launched in 2017 aboard European Space Agency's Mercury Planetary Orbiter as part of the BepiColombo Laser Altimeter, which, after a 6-years cruise, will start recording topographic data from orbital altitudes between 400 and 1500 km above Mercury's surface.

  19. A design of atmospheric laser communication system based on semiconductor laser

    Science.gov (United States)

    Rao, Jionghui; Yao, Wenming; Wen, Linqiang

    2016-01-01

    This paper uses semiconductor laser with 905nm wave length as light source to design a set of short-distance atmospheric laser communication system. This system consists of laser light source, launch modulation circuit, detector, receiving and amplifying circuit and so on. First, this paper analyzes the factors which lead to the decrease of luminous power of laser communication link under the applicable environment-specific sea level, then this paper elicits the relationship of luminous power of receiving optical systems and distance, slant angle and divergence angle which departures from the laser beam axis by using gaussian beam geometric attenuation mode. Based on the two reasons that PPM modulation theory limits the transmission rate of PPM modulation, that is, this paper makes an analysis on repetition frequency and pulse width of laser, makes theoretical calculation for typical parameters of semiconductor laser and gets the repetition frequency which is 10KHz, pulse width is50ns, the transmission rate is 71.66 Kb/s, at this time, modulation digit is 9; then this paper selects frame synchronization code of PPM modulation and provides implementation method for test; lastly, programs language based on Verilog, uses the FPGA development board to realize PPM modulation code and does simulation test and hardware test. This paper uses APD as the detector of receiving and amplifying circuit. Then this paper designs optical receiving circuit such as amplifying circuit, analog-digital conversion circuit based on the characteristics of receipt.

  20. Detection performance of laser range-gated imaging system

    Science.gov (United States)

    Xu, Jun; Li, Xiaofeng; Luo, Jijun; Zhang, Shengxiu; Xu, Yibin

    2010-10-01

    Laser radar is rapidly developing towards very capable sensors for number of applications such as military sensing and guidance, auto collision avoidance, robotic vision and atmospheric sensing. In this paper, the detection performance of non-scanned Laser Rang-gated (LRG) imaging system is studied. In order to compute the detection range of laser active imaging system, the range equation is derived by using laser illuminating model and considering factors which affect system imaging quality. According to the principle of laser radar and the characters of objects and the detectors in special applied setting, it mainly deduced the non-scanned laser radar range equation of the range-gated system, meanwhile, the SNR model of non-scanned LRG imaging system is set up. Then, relationship of the detection probability, the false alarm probability and the signal-to-noise ratio in the non-scanned LRG imaging system are analyzed, the influence factors of system's performance are pointed out, and the solution is proposed. The detection performance simulation software of non-scanned LRG imaging system is designed with MATLAB and the performance of the imaging system is simulated.

  1. Coupling of Laser-Generated Electrons with Conventional Accelerator Devices

    CERN Document Server

    Antici, P; Benedetti, C; Chiadroni, E; Ferrario, M; Lancia, L; Migliorati, M; Mostacci, A; Palumbo, L; Rossi, A R; Serafini, L

    2011-01-01

    Laser-based electron acceleration is attracting strong interest from the conventional accelerator community due to its outstanding characteristics in terms of high initial energy, low emittance and high beam current. Unfortunately, such beams are currently not comparable to those of conventional accelerators, limiting their use for the manifold applications that a traditional accelerator can have. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both, a versatile electron source and a controllable beam. In this paper we show that some parameters commonly used by the particle accelerator community must be reconsidered when dealing with laser-plasma beams. Starting from the parameters of laser-generated electrons which can be obtained nowadays by conventional multi hundred TW laser systems, we compare different conventional magnetic lattices able to capture and transport those GeV...

  2. Battlefield Lasers and Opto-electronics Systems (Review Paper

    Directory of Open Access Journals (Sweden)

    A. K. Maini

    2010-03-01

    Full Text Available During the last four decades or so, there has been an explosive growth in commercial, industrial, medical, scientific, technological, and above all, military usage of laser devices and systems. In fact, lasers have influenced every conceivable area of application during this period. While the expansion of non-military application spectrum of lasers is primarily driven by emergence of a large number of laser wavelengths followed by ever increasing power levels and reducing price tags at which those wavelengths could be generated, the military applications of lasers and related electro-optic devices have grown mainly because of technological maturity of the lasers that were born in the late 1960's and the early 1970's. Lasers have been used in various military applications since the early days of development that followed the invention of this magical device. There has been large scale proliferation of lasers and opto-electronic devices and systems for applications like range finding, target designation, target acquisition and tracking, precision guided munitions, etc. during 1970's and 1980's. These devices continue to improve in performance and find increased acceptance and usage in the contemporary battlefield scenario. Technological advances in optics, opto-electronics, and electronics, leading to more rugged, reliable, compact and efficient laser devices are largely responsible for making these indispensable in modern warfare. Past one decade or so has seen emergence of some new potential areas of usage. Some of these areas include rapid growth in the usage of lasers and opto-electronics devices and systems for electrooptic countermeasure (EOCM applications, test and evaluation systems that can perform online functionality checks on military opto-electronics systems and also their interoperability. In this paper, an overview of the current and emerging military applications of lasers and opto-electronics systems has been given with an outline

  3. Semiconductor Mode-Locked Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten

    2003-01-01

    The thesis deals with the design and fabrication of semiconductor mode-locked lasers for use in optical communication systems. The properties of pulse sources and characterization methods are described as well as requirements for application in communication systems. Especially, the importance of......, and ways to reduce high-frequency jitter is discussed. The main result of the thesis is a new design of the epitaxial structure that both enables simplified fabrication and improves the properties of monolithic lasers. 40 GHz monolithic lasers with record low jitter and high power is presented as well...... as the first 10 GHz all-active monolithic laser with both short pulses and low jitter.Results from external cavity mode-locked lasers are also reported along with an investigation of the influence of the operating conditions on the performance of the device. Antireflection coatings are a critical limiting...

  4. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides complete open-loop test capability for semi-active laser (SAL) seekers/sensors operating at 1.064 microns. ALSPES provides characterizations...

  5. Focused laser lithographic system with sub-wavelength resolution based on vortex laser induced opacity of photochromic material.

    Science.gov (United States)

    Wei, Zhen; Bai, Jian; Xu, Jianfeng; Wang, Chen; Yao, Yuan; Hu, Neibin; Liang, Yiyong; Wang, Kaiwei; Yang, Guoguang

    2014-12-01

    A focused laser lithographic system combines with vortex laser induced opacity of photochromic layer to write patterns with linewidth below wavelength. A photochromic layer is formed by coating the mixture of metanil yellow and aqueous PVA solution on the photoresist layer. In our system, the center of a lithographic laser with a 405 nm wavelength coincides with the center of vortex laser with a 532 nm wavelength. When a photochromic layer is illuminated by both lasers simultaneously, the absorbance for the lithographic laser decreases at the hollow region of the vortex laser but increases at its annular region, so that a transparent aperture for the lithographic laser is created and its size could be tuned by changing the power of vortex laser; therefore, the linewidth of written patterns is variable. Experimentally, using a 20× lens (NA = 0.4), this system condenses the linewidth of written patterns from 6614 to 350 nm.

  6. Combined laser ultrasonics, laser heating, and Raman scattering in diamond anvil cell system

    Science.gov (United States)

    Zinin, Pavel V.; Prakapenka, Vitali B.; Burgess, Katherine; Odake, Shoko; Chigarev, Nikolay; Sharma, Shiv K.

    2016-12-01

    We developed a multi-functional in situ measurement system under high pressure equipped with a laser ultrasonics (LU) system, Raman device, and laser heating system (LU-LH) in a diamond anvil cell (DAC). The system consists of four components: (1) a LU-DAC system (probe and pump lasers, photodetector, and oscilloscope) and DAC; (2) a fiber laser, which is designed to allow precise control of the total power in the range from 2 to 100 W by changing the diode current, for heating samples; (3) a spectrometer for measuring the temperature of the sample (using black body radiation), fluorescence spectrum (spectrum of the ruby for pressure measurement), and Raman scattering measurements inside a DAC under high pressure and high temperature (HPHT) conditions; and (4) an optical system to focus laser beams on the sample and image it in the DAC. The system is unique and allows us to do the following: (a) measure the shear and longitudinal velocities of non-transparent materials under HPHT; (b) measure temperature in a DAC under HPHT conditions using Planck's law; (c) measure pressure in a DAC using a Raman signal; and (d) measure acoustical properties of small flat specimens removed from the DAC after HPHT treatment. In this report, we demonstrate that the LU-LH-DAC system allows measurements of velocities of the skimming waves in iron at 2580 K and 22 GPa.

  7. Combined laser ultrasonics, laser heating, and Raman scattering in diamond anvil cell system.

    Science.gov (United States)

    Zinin, Pavel V; Prakapenka, Vitali B; Burgess, Katherine; Odake, Shoko; Chigarev, Nikolay; Sharma, Shiv K

    2016-12-01

    We developed a multi-functional in situ measurement system under high pressure equipped with a laser ultrasonics (LU) system, Raman device, and laser heating system (LU-LH) in a diamond anvil cell (DAC). The system consists of four components: (1) a LU-DAC system (probe and pump lasers, photodetector, and oscilloscope) and DAC; (2) a fiber laser, which is designed to allow precise control of the total power in the range from 2 to 100 W by changing the diode current, for heating samples; (3) a spectrometer for measuring the temperature of the sample (using black body radiation), fluorescence spectrum (spectrum of the ruby for pressure measurement), and Raman scattering measurements inside a DAC under high pressure and high temperature (HPHT) conditions; and (4) an optical system to focus laser beams on the sample and image it in the DAC. The system is unique and allows us to do the following: (a) measure the shear and longitudinal velocities of non-transparent materials under HPHT; (b) measure temperature in a DAC under HPHT conditions using Planck's law; (c) measure pressure in a DAC using a Raman signal; and (d) measure acoustical properties of small flat specimens removed from the DAC after HPHT treatment. In this report, we demonstrate that the LU-LH-DAC system allows measurements of velocities of the skimming waves in iron at 2580 K and 22 GPa.

  8. Optical response in a laser-driven quantum pseudodot system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, D. Gul [Physics Department, Graduate School of Natural and Applied Sciences, Dokuz Eylül University, 35390 Izmir (Turkey); Sakiroglu, S., E-mail: serpil.sakiroglu@deu.edu.tr [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey); Ungan, F.; Yesilgul, U. [Department of Optical Engineering, Faculty of Technology, Cumhuriyet University, 58140 Sivas (Turkey); Kasapoglu, E. [Physics Department, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Sari, H. [Department of Primary Education, Faculty of Education, Cumhuriyet University, 58140 Sivas (Turkey); Sokmen, I. [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey)

    2017-03-15

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  9. Synchronous Chaos Generation in an ^-Doped Fiber Laser System

    National Research Council Canada - National Science Library

    Gomez-Pavon, L. C; Munoz-Pacheco, J. M; Luis-Ramos, A

    2015-01-01

    ...+ -doped fiber lasers is experimentally analyzed. Using a single amplitude modulator in the system, synchronous chaos generation is obtained at two different modulation frequencies, i.e., 10.38 and 3.85 MHz...

  10. Optical Systems For High Power Laser Beam Delivery

    Science.gov (United States)

    Durville, Frederic M.; Cilia, D.

    1989-03-01

    During the pst fifteen years, pwerful lasers have been developed for industrial applications such as cutting, piercing, welding, engraving, etc... Convenient and reliable delivery systems are still needed to widen their field of application.

  11. Laser-produced plasma source system development

    Science.gov (United States)

    Fomenkov, Igor V.; Brandt, David C.; Bykanov, Alexander N.; Ershov, Alexander I.; Partlo, William N.; Myers, David W.; Böwering, Norbert R.; Vaschenko, Georgiy O.; Khodykin, Oleh V.; Hoffman, Jerzy R.; Vargas L., Ernesto; Simmons, Rodney D.; Chavez, Juan A.; Chrobak, Christopher P.

    2007-03-01

    This paper describes the development of laser produced plasma (LPP) technology as an EUV source for advanced scanner lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193 nm immersion technology for critical layer patterning below 32 nm beginning with beta generation scanners in 2009. This paper describes the development status of subsystems most critical to the performance to meet joint scanner manufacturer requirements and semiconductor industry standards for reliability and economic targets for cost of ownership. The intensity and power of the drive laser are critical parameters in the development of extreme ultraviolet LPP lithography sources. The conversion efficiency (CE) of laser light into EUV light is strongly dependent on the intensity of the laser energy on the target material at the point of interaction. The total EUV light generated then scales directly with the total incident laser power. The progress on the development of a short pulse, high power CO2 laser for EUV applications is reported. The lifetime of the collector mirror is a critical parameter in the development of extreme ultra-violet LPP lithography sources. The deposition of target materials and contaminants, as well as sputtering of the collector multilayer coating and implantation of incident particles can reduce the reflectivity of the mirror substantially over the exposure time even though debris mitigation schemes are being employed. The results of measurements of high energy ions generated by a short-pulse CO2 laser on a laser-produced plasma EUV light source with Sn target are presented. Droplet generation is a key element of the LPP source being developed at Cymer for EUV lithography applications. The main purpose of this device is to deliver small quantities of liquid target material as droplets to the laser focus. The EUV light in such configuration is obtained as a result of creating a highly ionized plasma from the material of the

  12. Chaos and Synchronization in Delayed System : Applications to Laser Networks

    Directory of Open Access Journals (Sweden)

    Schöll Eckehard

    2013-05-01

    Full Text Available We discuss recent results on chaos synchronization of delayed systems. We investigate the limit of large coupling delays and discuss how in this limit the stability problem for the synchronized solution is drastically simplified. We use these results to derive rigorous conditions for chaos synchronization of all-optically coupled laser networks. In laser systems the optical coupling phases have to be taken into account and give rise to interference conditions. We show that the relative phases between lasers can be used to optimize the effective coupling matrix.

  13. The National Ignition Facility front-end laser system

    Energy Technology Data Exchange (ETDEWEB)

    Burkhart, S.C.; Beach, R.J.; Crane, J.H.; Davin, J.M.; Perry, M.D.; Wilcox, R.B.

    1995-07-07

    The proposed National Ignition Facility is a 192 beam Nd:glass laser system capable of driving targets to fusion ignition by the year 2005. A key factor in the flexibility and performance of the laser is a front-end system which provides a precisely formatted beam to each beamline. Each of the injected beams has individually controlled energy, temporal pulseshape, and spatial shape to accommodate beamline-to-beamline variations in gain and saturation. This flexibility also gives target designers the options for precisely controlling the drive to different areas of the target. The design of the Front-End laser is described, and initial results are discussed.

  14. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  15. Ultrarelativistic laser systems based on coherent beam combining

    Science.gov (United States)

    Bagayev, S. N.; Trunov, V. I.; Pestryakov, E. V.; Frolov, S. A.; Leschenko, V. E.; Kirpichnikov, A. V.; Kokh, A. E.; Petrov, V. V.; Vasiliev, V. A.

    2012-07-01

    Conceptual design for femtosecond laser system of exawatt class, based on multi-channel amplifier and coherent field combining of petawatt amplifier channels with phase-frequency controlled radiation by optical clock are discussed. The scheme of start petawatt level few-cycle laser system with stable phase-frequency parameters determinated by the accuracy of the optical standard based on parametric amplification in big-size LBO crystals pumped by picosecond pulses is analyzed.

  16. Ultrarelativistic laser systems based on coherent beam combining

    Energy Technology Data Exchange (ETDEWEB)

    Bagayev, S. N.; Trunov, V. I.; Pestryakov, E. V.; Frolov, S. A.; Leschenko, V. E.; Kirpichnikov, A. V.; Kokh, A. E.; Petrov, V. V.; Vasiliev, V. A. [Institute of Laser Physics SB RAS, Ac. Lavrentyev' s prosp., 13/3, Novosibirsk (Russian Federation); Institute of Geology and Mineralogy SB RAS, Ac. Koptug' s prosp., 3, Novosibirsk (Russian Federation); Institute of Laser Physics SB RAS, Ac. Lavrentyev' s prosp., 13/3, Novosibirsk (Russian Federation)

    2012-07-11

    Conceptual design for femtosecond laser system of exawatt class, based on multi-channel amplifier and coherent field combining of petawatt amplifier channels with phase-frequency controlled radiation by optical clock are discussed. The scheme of start petawatt level few-cycle laser system with stable phase-frequency parameters determinated by the accuracy of the optical standard based on parametric amplification in big-size LBO crystals pumped by picosecond pulses is analyzed.

  17. Compact-range coordinate system established using a laser tracker.

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, Floyd H.; Bryce, Edwin Anthony

    2006-12-01

    Establishing a Cartesian coordinate reference system for an existing Compact Antenna Range using the parabolic reflector is presented. A SMX (Spatial Metrix Corporation) M/N 4000 laser-based coordinate measuring system established absolute coordinates for the facility. Electric field characteristics with positional movement correction are evaluated. Feed Horn relocation for alignment with the reflector axis is also described. Reference points are established for follow-on non-laser alignments utilizing a theodolite.

  18. An ultraviolet laser system for laser cooling and trapping of metastable magnesium

    CERN Document Server

    Kulosa, A P; Riedmann, M P; Pape, A; Wübbena, T W; Fim, D B; Rühmann, S; Zipfel, K H; Kelkar, H; Ertmer, W; Rasel, E M

    2012-01-01

    We report on a reliable laser system for cooling magnesium in the metastable 3P manifold. The three relevant transitions coupling the 3P to the 3D manifold are separated by several hundred GHz and can be excited with light at 383 nm. The light is generated with master oscillator power amplifiers at 766 nm that feed resonant second harmonic generation stages each yielding 100 mW of UV light. The Pound-Drever-Hall stabilisation scheme is used to lock all three lasers to one stabilised reference cavity. We generate specific sidebands on each laser beam via diode current modulation in order to read out the error signals with a single photo diode. In addition, the same sidebands are used for locking the second harmonic generation cavities to the master oscillators. In this way, the complexity of the laser system is largely reduced providing a high reliability as necessary for experiments such as the magnesium lattice clock.

  19. A compact field-portable double-pulse laser system to enhance laser induced breakdown spectroscopy

    Science.gov (United States)

    Li, Shuo; Liu, Lei; Yan, Aidong; Huang, Sheng; Huang, Xi; Chen, Rongzhang; Lu, Yongfeng; Chen, Kevin

    2017-02-01

    This paper reports the development of a compact double-pulse laser system to enhance laser induced breakdown spectroscopy (LIBS) for field applications. Pumped by high-power vertical-surface emitting lasers, the laser system that produces 16 ns pulse at 12 mJ/pulse with total weight less than 10 kg is developed. The inter-pulse delay can be adjusted from 0 μ s with 0.5 μ s increment. Several LIBS experiments were carried out on NIST standard aluminum alloy samples. Comparing with the single-pulse LIBS, up to 9 times enhancement in atomic emission line was achieved with continuum background emission reduced by 70%. This has led to up to 10 times improvement in the limit of detection. Signal stability was also improved by 128% indicating that a more robust and accurate LIBS measurement can be achieved using a compact double-pulse laser system. This paper presents a viable and field deployable laser tool to dramatically improve the sensitivity and applicability of LIBS for a wide array of applications.

  20. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  1. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  2. High removal rate laser-based coating removal system

    Science.gov (United States)

    Matthews, Dennis L.; Celliers, Peter M.; Hackel, Lloyd; Da Silva, Luiz B.; Dane, C. Brent; Mrowka, Stanley

    1999-11-16

    A compact laser system that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1000 ft.sup.2 /hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

  3. Review of Laser Lightcraft Propulsion System (Preprint)

    Science.gov (United States)

    2007-10-16

    breathing mode up to Mach 5 and 30 km altitude, and in laser thermal rocket mode (using liquid, gaseous, or Delrin ablation propellant) in space...to orbit. Once the Lightcraft reaches very high altitude and climbs above the atmosphere, it begins to operate in the thermal rocket mode using on

  4. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  5. Criteria for the evaluation of laser solar energy converter systems

    Science.gov (United States)

    Harries, W. L.

    1985-01-01

    Assuming that a parabolic insolation-collection mirror-based solar pumped laser has a collector and heat emitter whose weights are proportional to their areas, and that the weight of the laser is negligible by comparison, the output power/unit weight can be expressed in terms of the efficiencies and working temperatures of the system. This ratio appears to be several times higher for an IBr laser than for one operating on C3F7I, because the solar utilization efficiency is greater for the former despite its lower working temperature.

  6. Research on laser induced acoustic source based underwater communication system

    Science.gov (United States)

    Lei, Lihua; Zhou, Ju; Zhang, Lei; Wan, Xiaoyun

    2016-10-01

    Acoustic transducers are traditionally used to generate underwater acoustical energy with the device physically immersed in water. Novel methods are required for communicating from an in-air platform or surface vessel to a submerged vessel. One possible noncontact downlink communication system involves the use of laser induced acoustic source. The most common mechanisms of opto-acoustic energy conversion are, by order of increasing laser energy density and efficiency, thermal expansion, surface evaporation and optical breakdown. The laser induced acoustic source inherently bears the obvious advantage of not requiring any physical transducer in the medium. At the same time, acoustic energy propagation is efficient in water, whereas optical energy propagate well in air, leading to a more efficiency opto-acoustic communication method. In this paper, an opto-acoustic underwater Communication system is described, aiming to study and analysis whether laser induced sound could achieve good performance for effective communication in practical application.

  7. Acousto-optic laser projection systems for displaying TV information

    Science.gov (United States)

    Gulyaev, Yu V.; Kazaryan, M. A.; Mokrushin, Yu M.; Shakin, O. V.

    2015-04-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation.

  8. A Direct Diode Laser System Using a Planar Lightwave Circuit

    Science.gov (United States)

    Hasegawa, Kazuo; Matsubara, Hiroyuki; Ichikawa, Tadashi; Maeda, Mitsutoshi; Ito, Hiroshi

    2008-08-01

    In this paper we propose a direct diode laser (DDL) system consisting of laser diode (LD) bars, a planar lightwave circuit (PLC), and an optical fiber. We have developed a PLC as an optical power combiner and an LD mounting technology that is suitable for coupling to the PLC. A DDL system is presented that consists of six LD-PLC optical modules for the laser-welding of highly heat-resistant plastics. The total output power is in the 200 W class, with a spot diameter of 5.52 mm for the major axis and 5.00 mm for the minor axis at a focal length of 50 mm. The total output efficiency is 60.9% from the laser diode to the welding torch.

  9. Mid-IR laser system for advanced neurosurgery

    Science.gov (United States)

    Klosner, M.; Wu, C.; Heller, D. F.

    2014-03-01

    We present work on a laser system operating in the near- and mid-IR spectral regions, having output characteristics designed to be optimal for cutting various tissue types. We provide a brief overview of laser-tissue interactions and the importance of controlling certain properties of the light beam. We describe the principle of operation of the laser system, which is generally based on a wavelength-tunable alexandrite laser oscillator/amplifier, and multiple Raman conversion stages. This configuration provides robust access to the mid-IR spectral region at wavelengths, pulse energies, pulse durations, and repetition rates that are attractive for neurosurgical applications. We summarize results for ultra-precise selective cutting of nerve sheaths and retinas with little collateral damage; this has applications in procedures such as optic-nerve-sheath fenestration and possible spinal repair. We also report results for cutting cornea, and dermal tissues.

  10. Stabilized master laser system for differential absorption lidar.

    Science.gov (United States)

    Dinovitser, Alex; Hamilton, Murray W; Vincent, Robert A

    2010-06-10

    Wavelength accuracy and stability are key requirements for differential absorption lidar (DIAL). We present a control and timing design for the dual-stabilized cw master lasers in a pulsed master-oscillator power-amplifier configuration, which forms a robust low-cost water-vapor DIAL transmitter system. This design operates at 823 nm for water-vapor spectroscopy using Fabry-Perot-type laser diodes. However, the techniques described could be applied to other laser technologies at other wavelengths. The system can be extended with additional off-line or side-line wavelengths. The on-line master laser is locked to the center of a water absorption line, while the beat frequency between the on-line and the off-line is locked to 16 GHz using only a bandpass microwave filter and low-frequency electronics. Optical frequency stabilities of the order of 1 MHz are achieved.

  11. The Laser Shaft Alignment System with Dual PSDs

    Institute of Scientific and Technical Information of China (English)

    JIAO Guohua; LI Yulin; ZHANG Dongbo; LI Tonghai; HU Baowen

    2006-01-01

    Shaft alignment is an important technique during installation and maintenance of a rotating machine. A high-precision laser alignment system has been designed with dual PSDs (Position Sensing Detector) to change traditional manual way of shaft alignment and to make the measurement easier and more accurate. The system is comprised of two small measuring units (laser transmitter and detector) and a PDA (Personal Digital Assistant) with the measurement software. The laser alignment system with dual PSDs was improved on a single PSD system, and it gets higher measurement accuracy than the previous design, and it has been succeeded in designing and implement for actual shaft alignment. In the system, the range of offset measurement is ±4 mm, and the resolution is 1.5 μm, and the accuracy is less than 2 μm.

  12. A laser shaft alignment system with dual PSDs

    Institute of Scientific and Technical Information of China (English)

    JIAO Guo-hua; LI Yu-lin; ZHANG Dong-bo; LI Tong-hai; HU Bao-wen

    2006-01-01

    Shaft alignment is an important technique during installation and maintenance of a rotating machine. A high-precision laser alignment system has been designed with dual PSDs (Position Sensing Detector) to change traditional manual way of shaft alignment and to make the measurement easier and more accurate. The system is comprised of two small measuring units (laser transmitter and detector) and a PDA (Personal Digital Assistant) with measurement software. The laser alignment system with dual PSDs was improved on a single PSD system, and yields higher measurement accuracy than the previous design, and has been successful for designing and implements actual shaft alignment. In the system, the range of offset measurement is ±4 mm, and the resolution is 1.5 μm, with accuracy being less than 2 μm.

  13. Laser fusion program at LASL. Progress report, January 1--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Skoberne, F.; Stark, E. (comp.)

    1978-04-01

    Progress in the development of high-energy short-pulse CO/sub 2/ laser systems for fusion research is reported. Experiments, which led to the generation of approximately 5 x 10/sup 5/ fusion neutron on our Two-Beam System in early 1977, with laser output powers of 0.16 to 0.4 TW, are described. These significant results and recent theoretical advancements indicate that the CO/sub 2/ laser is the driver of greatest promise for commercial laser fusion application. Initial test runs on the Eight-Beam System achieved an output energy of approximately 850 J with one beam of less than 1-ns duration, which makes us certain that the design goal of the system will be met on time. Antares, our 100- to 200-TW target irradiation system, is progressing on schedule. Very promising test results obtained on the prototype, as well as encouraging progress in optics development, are summarized. Modifications to the LASNEX code are described. Further progress in various target fabrication and nondestructive fuel-assay techniques is reported, and the development of new diagnostic tools is described. Among new tools are single-channel and four-channel x-ray diode assemblies, both using aluminum cathodes, to study the time history of soft x-ray emission; and a 10-..mu..m microscope, developed in-house, which aids us in verifying optimum target alignment and laser focusing. A design modification of the magnetically protected reactor cavity concept is being investigated.

  14. Wavelength stabilized multi-kW diode laser systems

    Science.gov (United States)

    Köhler, Bernd; Unger, Andreas; Kindervater, Tobias; Drovs, Simon; Wolf, Paul; Hubrich, Ralf; Beczkowiak, Anna; Auch, Stefan; Müntz, Holger; Biesenbach, Jens

    2015-03-01

    We report on wavelength stabilized high-power diode laser systems with enhanced spectral brightness by means of Volume Holographic Gratings. High-power diode laser modules typically have a relatively broad spectral width of about 3 to 6 nm. In addition the center wavelength shifts by changing the temperature and the driving current, which is obstructive for pumping applications with small absorption bandwidths. Wavelength stabilization of high-power diode laser systems is an important method to increase the efficiency of diode pumped solid-state lasers. It also enables power scaling by dense wavelength multiplexing. To ensure a wide locking range and efficient wavelength stabilization the parameters of the Volume Holographic Grating and the parameters of the diode laser bar have to be adapted carefully. Important parameters are the reflectivity of the Volume Holographic Grating, the reflectivity of the diode laser bar as well as its angular and spectral emission characteristics. In this paper we present detailed data on wavelength stabilized diode laser systems with and without fiber coupling in the spectral range from 634 nm up to 1533 nm. The maximum output power of 2.7 kW was measured for a fiber coupled system (1000 μm, NA 0.22), which was stabilized at a wavelength of 969 nm with a spectral width of only 0.6 nm (90% value). Another example is a narrow line-width diode laser stack, which was stabilized at a wavelength of 1533 nm with a spectral bandwidth below 1 nm and an output power of 835 W.

  15. Ring-laser gyroscope system using dispersive element(s)

    Science.gov (United States)

    Smith, David D. (Inventor)

    2010-01-01

    A ring-laser gyroscope system includes a ring-laser gyroscope (RLG) and at least one dispersive element optically coupled to the RLG's ring-shaped optical path. Each dispersive element has a resonant frequency that is approximately equal to the RLG's lasing frequency. A group index of refraction defined collectively by the dispersive element(s) has (i) a real portion that is greater than zero and less than one, and (ii) an imaginary portion that is less than zero.

  16. X-ray Emission from Young Stars in the TW Hya Association

    CERN Document Server

    Brown, Alexander; Ayres, Thomas R; France, Kevin; Brown, Joanna M

    2014-01-01

    The 9 Myr old TW Hya Association (TWA) is the nearest group (typical distances of $\\sim$50 pc) of pre-main-sequence (PMS) stars with ages less than 10 Myr and contains stars with both actively accreting disks and debris disks. We have studied the coronal X-ray emission from a group of low mass TWA common proper motion binaries using the {\\it{Chandra}} and {\\it{Swift}} satellites. Our aim is to understand better their coronal properties and how high energy photons affect the conditions around young stars and their role in photo-exciting atoms, molecules and dust grains in circumstellar disks and lower density circumstellar gas. Once planet formation is underway, this emission influences protoplanetary evolution and the atmospheric conditions of the newly-formed planets. The X-ray properties for 7 individual stars (TWA 13A, TWA 13B, TWA 9A, TWA 9B, TWA 8A, TWA 8B, and TWA 7) and 2 combined binary systems (TWA 3AB and TWA 2AB) have been measured. All the stars with sufficient signal require two-component fits to...

  17. Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546

    CERN Document Server

    Kama, M; van Dishoeck, E F; Hogerheijde, M; Folsom, C P; Miotello, A; Fedele, D; Belloche, A; Güsten, R; Wyrowski, F

    2016-01-01

    The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: HD 100546 and TW Hya. We combine our recent detections of C$^{0}$ in these disks with observations of other carbon reservoirs (CO, C$^{+}$, C$_{2}$H) and gas mass and warm gas tracers (HD, O$^{0}$), as well as spatially resolved ALMA observations and the spectral energy distribution. The disks are modelled with the DALI 2D physical-chemical code. Stellar abundances for HD 100546 are derived from archival spectra. Upper limits on HD emission from HD 100546 place an upper limit on the total disk mass of $\\leq0.1\\,M_{\\odot}$. The gas-phase carbon abundance in the atmosphere of this warm Herbig disk is at most moderately depleted compared to the interstellar medium, with [C]/[H]$_{\\rm gas}=(0.1-1.5)\\times 1...

  18. M Stars in the TW Hya Association: Stellar X-rays and Disk Dissipation

    CERN Document Server

    Kastner, Joel H; Punzi, Kristina; Stelzer, Beate; Gorti, Uma; Pascucci, Ilaria; Argiroffi, Costanza

    2016-01-01

    To investigate the potential connection between the intense X-ray emission from young, low-mass stars and the lifetimes of their circumstellar, planet-forming disks, we have compiled the X-ray luminosities ($L_X$) of M stars in the $\\sim$8 Myr-old TW Hya Association (TWA) for which X-ray data are presently available. Our investigation includes analysis of archival Chandra data for the TWA binary systems TWA 8, 9, and 13. Although our study suffers from poor statistics for stars later than M3, we find a trend of decreasing $L_X/L_{bol}$ with decreasing $T_{eff}$ for TWA M stars wherein the earliest-type (M0--M2) stars cluster near $\\log{(L_X/L_{bol})} \\approx -3.0$ and then $\\log{(L_X/L_{bol})}$ decreases, and its distribution broadens, for types M4 and later. The fraction of TWA stars that display evidence for residual primordial disk material also sharply increases in this same (mid-M) spectral type regime. This apparent anticorrelation between the relative X-ray luminosities of low-mass TWA stars and the lo...

  19. Laser Ground System for Communication Experiments with ARTEMIS

    Science.gov (United States)

    Kuzkov, Volodymyr; Volovyk, Dmytro; Kuzkov, Sergii; Sodnik, Zoran; Pukha, Sergii; Caramia, Vincenzo

    2012-10-01

    The ARTEMIS satellite with the OPALE laser communication terminal on-board was launched on 12 July, 2001. 1789 laser communications sessions were performed between ARTEMIS and SPOT-4 (PASTEL) from 01 April 2003 to 09 January 2008 with total duration of 378 hours. Regular laser communication experiments between ESA's Optical Ground Station (OGS - altitude 2400 m above see level) and ARTEMIS in various atmosphere conditions were also performed. The Japanese Space Agency (JAXA) launched the KIRARI (OICETS) satellite with laser communication terminal called LUCE. Laser communication links between KIRARI and ARTEMIS were successfully realized and international laser communications experiments from the KIRARI satellite were also successfully performed with optical ground stations located in the USA (JPL), Spain (ESA OGS), Germany (DLR), and Japan (NICT). The German Space Agency (DLR) performed laser communication links between two LEO satellites (TerraSAR-X and NFIRE), demonstrating data transfer rates of 5.6Gbit/s and performed laser communication experiments between the satellites and the ESA optical ground station. To reduce the influence of weather conditions on laser communication between satellites and ground stations, a network of optical stations situated in different atmosphere regions needs to be created. In 2002, the Main Astronomical Observatory (MAO) started the development of its own laser communication system to be placed into the Cassegrain focus of its 0.7m AZT-2 telescope (Fe = 10.5m), located in Kyiv 190 meters above sea level. The work was supported by the National Space Agency of Ukraine and by ESA ARTEMIS has an orbital position of 21.4° E and an orbital inclination of more than 9.75°. As a result we developed a precise tracking system for AZT-2 telescope (weighing more than 2 tons) using micro-step motors. Software was developed for computer control of the telescope to track the satellite's orbit and a tracking accuracy of 0.6 arcsec was achieved

  20. RF Design of the TW Buncher for the CLIC Drive Beam Injector

    CERN Document Server

    Shaker, H

    2015-01-01

    The CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the first report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This report includes the design of the power couplers. The fundamental mode beam loading and higher order modes effect were preliminary studied.

  1. EPSON dorimio EMP-TW10H投影机

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    爱普生去年用dorimio品牌第一次发售了dorimio EMP-TW10投影机。具有普及性价格、真实感动的高画质和动人的大画面.加上简单到谁都能使用的理念.因此得到市场的好评。这次爱普生推出了EMP-TW10的升级版EMP-TW10H.在万元级的投影市场上又增加了一个很有竞争力的选手。

  2. RF Design of the TW Buncher for the CLIC Drive Beam Injector (2nd report)

    CERN Document Server

    Shaker, Hamed

    2016-01-01

    CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub-harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the second report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This second report includes the study of HOM effects, retuning the cells, study of dimensional tolerances and the heat dissipation on the surface.

  3. Optically pumped planar waveguide lasers: Part II: Gain media, laser systems, and applications

    Science.gov (United States)

    Grivas, Christos

    2016-01-01

    The field of optically pumped planar waveguide lasers has seen a rapid development over the last two decades driven by the requirements of a range of applications. This sustained research effort has led to the demonstration of a large variety of miniature highly efficient laser sources by combining different gain media and resonator geometries. One of the most attractive features of waveguide lasers is the broad range of regimes that they can operate, spanning from continuous wave and single frequency through to the generation of femtosecond pulses. Furthermore, their technology has experienced considerable advances to provide increased output power levels, deriving benefits from the relative immunity from the heat generated in the gain medium during laser operation and the use of cladding-pumped architectures. This second part of the review on optically pumped planar waveguide lasers provides a snapshot of the state-of-the-art research in this field in terms of gain materials, laser system designs, and as well as a perspective on the status of their application as real devices in various research areas.

  4. Rayleigh Laser Guide Star Systems: Application to the University of Illinois Seeing Improvement System

    Science.gov (United States)

    Thompson, Laird A.; Teare, Scott W.

    2002-09-01

    Laser guide stars created by Rayleigh scattering provide a reasonable means to monitor atmospheric wavefront distortions for real-time correction by adaptive optics systems. Because of the λ-4 wavelength dependence of Rayleigh scattering, short-wavelength lasers are a logical first choice for astronomical laser guide star systems, and in this paper we describe the results from a sustained experimental effort to integrate into an adaptive optics system a 351 nm Rayleigh laser guide star created at an altitude of 20 km (above mean sea level) at the Mount Wilson 2.5 m telescope. In addition to providing obvious scientific benefits, the 351 nm laser guide star projected by the University of Illinois Seeing Improvement System is ``stealth qualified'' in terms of the Federal Aviation Administration and airplane avoidance. Because of the excellent return signal at the wavefront sensor, there is no doubt that future applications will be found for short-wavelength Rayleigh-scattered laser guide stars.

  5. Experimental comparison of perfusion imaging systems using multi-exposure laser speckle, single-exposure laser speckle, and full-field laser Doppler

    Science.gov (United States)

    Thompson, Oliver; Bakker, Jimmy; Kloeze, Carla; Hondebrink, Erwin; Steenbergen, Wiendelt

    2012-03-01

    A variety of laser Doppler and laser speckle contrast systems have been constructed by various groups and companies, for commercial sale and for research. All rely on the same physical phenomenon - the dynamic laser speckle pattern generated by illuminating tissue with coherent light - but differ in details of system design, operation and analysis. We present a comparison between measurements made with three systems: a multi-exposure laser speckle contrast system built at Industrial Research Ltd, a commercial single-exposure laser speckle contrast system developed by Perimed AB (PSI NR) and the full-field laser Doppler camera built by the University of Twente (TOPCam). We compare the response to changing flows of all three systems. The systems are found to produce similar results for a variety of in-vivo and in-vitro measurements. Multi-exposure speckle contrast shows some advantages in information gained and insensitivity to static speckle, at the cost of increased complexity and measurement time.

  6. A portable laser system for high precision atom interferometry experiments

    CERN Document Server

    Schmidt, Malte; Giorgini, Antonio; Tino, Guglielmo M; Peters, Achim

    2010-01-01

    We present a modular rack-mounted laser system for the cooling and manipulation of neutral rubidium atoms which has been developed for the portable gravimeter GAIN, an atom interferometer that will be capable of performing high precision gravity measurements directly at sites of geophysical interest. This laser system is designed to be compact, mobile and robust, yet it still offers improvements over many conventional laboratory-based laser systems. Our system is contained in a standard 19" rack and emits light at five different wavelengths simultaneously on up to 12 fibre ports at a total output power of 800 mW. These wavelengths can be changed and switched between ports in less than a microsecond. The setup includes two phase-locked Raman lasers with a phase noise spectral density of less than 1 \\mu rad/sqrt(Hz) in the frequency range in which our gravimeter is most sensitive to noise. We characterize this laser system and evaluate the performance limits it imposes on an interferometer.

  7. Intrinsic normalized emittance growth in laser-driven electron accelerators

    Science.gov (United States)

    Migliorati, M.; Bacci, A.; Benedetti, C.; Chiadroni, E.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Rossi, A. R.; Serafini, L.; Antici, P.

    2013-01-01

    Laser-based electron sources are attracting strong interest from the conventional accelerator community due to their unique characteristics in terms of high initial energy, low emittance, and significant beam current. Extremely strong electric fields (up to hundreds of GV/m) generated in the plasma allow accelerating gradients much higher than in conventional accelerators and set the basis for achieving very high final energies in a compact space. Generating laser-driven high-energy electron beam lines therefore represents an attractive challenge for novel particle accelerators. In this paper we show that laser-driven electrons generated by the nowadays consolidated TW laser systems, when leaving the interaction region, are subject to a very strong, normalized emittance worsening which makes them quickly unusable for any beam transport. Furthermore, due to their intrinsic beam characteristics, controlling and capturing the full beam current can only be achieved improving the source parameters.

  8. Study of ultra-high gradient wakefield excitation by intense ultrashort laser pulses in plasma

    Science.gov (United States)

    Kotaki, Hideyuki; Kando, Masaki; Oketa, Takatsugu; Masuda, Shinichi; Koga, James K.; Kondo, Shuji; Kanazawa, Shuhei; Yokoyama, Takashi; Matoba, Toru; Nakajima, Kazuhisa

    2002-10-01

    We investigate a laser wakefield excited by intense laser pulses, and the possibility of generating an intense bright electron source by an intense laser pulse. The coherent wakefield excited by 2 TW, 50 fs laser pulses in a gas-jet plasma around 1018 cm-3 is measured with a time-resolved frequency domain interferometer (FDI). The results show an accelerating wakefield excitation of 20 GeV/m with good coherency. This is the first time-resolved measurement of laser wakefield excitation in a gas-jet plasma. The experimental results agree with the simulation results and linear theory. The pump-probe interferometer system of FDI will be modified to the optical injection system as a relativistic electron beam injector. In 1D particle in cell simulation we obtain results of high quality intense electron beam generation.

  9. [Tunable diode laser absorption spectroscopy system for trace ethylene detection].

    Science.gov (United States)

    Pan, Wei-Dong; Zhang, Jia-Wei; Dai, Jing-Min; Song, Kai

    2012-10-01

    Tunable diode laser absorption spectroscopy (TDLAS) was characterized by ultra-narrow line width laser and wavelength modulation, which makes it possible to scan a single absorption line. TDLAS has an advantage in trace gas analysis for its high resolution, high sensitivity and quick response. The 1 626.8 nm absorption line of ethylene was selected for detecting by analyzing its absorption line characteristic. The TDLAS system was developed with a white type multi-pass cell, combined with wavelength modulation and harmonic detection. Ethylene concentration ranges from 20 to 1 200 ppmv were tested using this system. The estimated detection limit of the system is 10 ppmv.

  10. Application Research on Space Laser Communication in Bistatic Radar System

    Institute of Scientific and Technical Information of China (English)

    李晓萍; 韩绍坤; 郝小宁

    2003-01-01

    There exist three synchronizing problems in the bistatic radar system that some signals of the radar receiver must be synchronized with those of the radar transmitter. Several methods realizing data transmission, which are used to complete the synchronization existing in the bistatic radar system, are described. Then a new idea is brought forward that employs space laser communication in the bistatic radar system to realize its data transmission. The theoretic analysis of the idea's usability and its merits are discussed in details. Finally the latest development of space laser communication is introduced, and the utility of the idea is pointed out further.

  11. Laser Fusion Program at LASL. Progress report, July 1--December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Skoberne, F. (comp.)

    1978-12-01

    Progress in the development of high-energy short-pulse CO/sub 2/ laser systems for fusion research is reported. Among the achievements discussed are an increase in on-target energy of the Two-Beam System to 375 J per beam; operation of one Eight-Beam System module at the design point of 1.2 kJ at a power of > 2 TW; and the on-schedule development of our 100- to 200-TW laser Antares. Target designs based on the LASNEX code incorporating new theoretical insights are described, culminating in a double-shell exploding-pusher target that attains a high degree of symmetry through hot-electron transport in an exploding outer shell. Studies of laser light absorption are outlined, which confirmed that the values for CO/sub 2/ are nearly identical to those obtained with Nd:glass lasers. Unique diagnostics are described, which allow one to measure properties of x-ray emission not previously accessible, and which provide absorption data of sufficient accuracy for direct comparison with theory. Finally, various feasibility and systems studies are summarized, such as the successful modeling of short-pulse amplification in large three-pass CO/sub 2/ laser amplifiers, as verified experimentally.

  12. Narrow-line diode laser system for laser cooling of strontium atoms on the intercombination transition

    Science.gov (United States)

    Li, Y.; Ido, T.; Eichler, T.; Katori, H.

    We report a diode laser system developed for narrow-line cooling and trapping on the 1S0-3P1 intercombination transition of neutral strontium atoms. Doppler cooling on this spin-forbidden transition with a line width of Γ/2π=7.1 kHz enables us to achieve sub-μK temperatures in a two-step cooling process. The required reduction of the laser line width to the kHz level was achieved by locking the laser to a tunable Fabry-Pérot cavity. The long-term drift (>0.1 s) of the reference cavity was compensated by employing the saturated absorption signal obtained from Sr vapor in a heat pipe of novel design. We demonstrate the potential of the system by performing spectroscopy of Sr atoms confined to the Lamb-Dicke regime in a one-dimensional optical lattice.

  13. A Diode-Laser-System for Laser-Assisted Bending of Brittle Materials

    Directory of Open Access Journals (Sweden)

    F. Bammer

    2011-01-01

    Full Text Available We developed a small and compact system of diode lasers, which can be inserted into the lower tools of a bending press. The parts of the system allow easy plug and play operation and can be installed for any bending length. The diode laser, which is based on 200 W laser bars on microchannel cooler, allows the heating of sheet metals in the forming zone shortly before and during the bending process. There is no unnecessary heating of other parts of the bending equipment, no wear of the tool, and, if properly done, no damage of the surface of the metal. The power per bending length is 16 kW/m.

  14. Apparatus, system, and method for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  15. Research on Image processing in laser triangulation system

    Energy Technology Data Exchange (ETDEWEB)

    Liu Kai; Wang Qianqian; Wang Yang; Liu Chenrui, E-mail: qqwang@bit.edu.cn [School of Optoelectronics, Beijing Institute of Technology, 100081 Beijing (China)

    2011-02-01

    Laser Triangulation Ranging is a kind of displacement distance measurement method which is based on the principle of optical triangulation using laser as the light source. It is superior in simple structure, high-speed, high-accuracy, anti-jamming capability and adaptability laser triangulation ranging. Therefore it is widely used in various fields such as industrial production, road test, three-dimensional face detection, and so on. In current study the features of the spot images achieved by CCD in laser triangulation system were analyzed, and the appropriate algorithms for spot images were discussed. Experimental results showed that the precision and stability of the spot location were enhanced significantly after applying these image processing algorithms.

  16. Recent developments in retinal lasers and delivery systems

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Yadav

    2014-01-01

    Full Text Available Photocoagulation is the standard of care for several ocular disorders and in particular retinal conditions. Technology has offered us newer lasing mediums, wavelengths and delivery systems. Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows laser treatment that is less time consuming and less painful. Now, it is possible to deliver a subthreshold micropulse laser that is above the threshold of biochemical effect but below the threshold of a visible, destructive lesion thereby preventing collateral damage. The advent of solid-state diode yellow laser allows us to treat closer to the fovea, is more effective for vascular structures and offers a more uniform effect in patients with light or irregular fundus pigmentation. Newer retinal photocoagulation options along with their advantages is discussed in this review.

  17. Tunable solid state laser system for dermatology applications

    Science.gov (United States)

    Azar, Zion; Bank, Alexander; Donskoy, Dmitri M.; Nechitailo, Vladimir S.

    1994-12-01

    The Q-switched Nd:YAG laser is the most recent in a series of pulsed laser systems for plastic surgery. The 532 nm wavelength has been shown to be absorbed by a variety of chromophores. These include tattoo pigments, oxygenated hemoglobin and melanin-containing epidermal cells. A simple multi-line solid state laser module pumped by double-frequency Q- switched YAG laser is presented. This solid state multi-line module enables tuning of the wavelength in the yellow spectral range to 560 nm or to 580 nm for dermatology applications. Conversion efficiency in excess of 70% was achieved at 10 Hz pulse repetition frequency and output energy per pulse of approximately 200 mJ.

  18. Multimode lasers as analogs of complex biological systems (a survey)

    Science.gov (United States)

    Danilov, O. B.; Rosanov, N. N.; Solov'ev, N. A.; Soms, L. N.

    2016-04-01

    Simulating the activity of complex biological systems, in particular, the human brain, is a topical problem the solution of which is necessary both for understanding their functioning and for developing new classes of computational system based on operating principles of the brain. Some features and analogies that can be found in the operation of laser systems and brain and used for developing new generation computational systems are discussed. The appropriateness of such analogies is justified by the fact that both laser systems and the brain are open (interacting with the environment) dissipative spatially distributed nonlinear systems. Therefore, laser optical systems and, in particular, systems with dissipative optical solitons offer an opportunity to experimentally and theoretically model some important cognitive brain functions. One of particularities of the brain operation is the ability to manipulate images. Proceeding from this, in this work, problems related to generation and amplification with laser of spatial structures (images), as well as to amplification of signals coming to it from outside are discussed.

  19. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

      Abstract: in this paper, the process of designing and developing a novel laser weeding test setup is explained. The main purpose of designing this system was to simulate the dynamic field conditions of a mobile vehicle capable of targeting weeds. This system consists of a rig containing three...

  20. Stability design of support systems in ICF lasers

    Science.gov (United States)

    Zhu, M. Z.; Wu, W. K.; Chen, G.; Zhan, H.; Xu, Y. L.; Chen, X. J.

    2016-10-01

    Within Inertial Confinement Fusion (ICF) laser systems, many independent laser beams are required to be positioned on target with a very high degree of accuracy until shots are complete. Optical elements that are capable of moving a laser beam on the target must meet the pointing error budget. Optical elements are typically supported by systems which consist of mounts, mount frames, support structures, and foundation. The stability design for support systems in ICF laser have been developed based on the designing and evaluating experience of ShenGuangIII (SGIII). This paper will provide the methodology of position error budget. The stability allocation is developed for evaluating the performance of support systems when they are subjected to multiple sources of excitations that can cause the motion of optical elements during alignment procedures and before shots. The vibrational stability design considerations of support systems are discussed on the fundamental frequency, ambient random vibration, and modal damping. The support structures of optical elements are the relatively large and massive hybrid structure of reinforced concrete and steel frame or vessels. While the reinforced concrete portions provide optical elements stability, the steel portions afford design flexibility. Finite element analyses of ambient random vibration are typically performed to evaluate the vibrational stability performances of support systems. Finally, this paper describes the ambient random vibration and beam pointing error measurements of SGIII. The measurements show the support systems of SGIII meet design requirement. These information can be used on similar systems.

  1. Direct laser additive fabrication system with image feedback control

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Michelle L. (Albuquerque, NM); Hofmeister, William H. (Nashville, TN); Knorovsky, Gerald A. (Albuquerque, NM); MacCallum, Danny O. (Edgewood, NM); Schlienger, M. Eric (Albuquerque, NM); Smugeresky, John E. (Pleasanton, CA)

    2002-01-01

    A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

  2. Mid-infrared supercontinuum laser system and its biomedical applications

    Science.gov (United States)

    Xia, Chenan

    A mid-infrared supercontinuum (SC) laser system is developed, which provides a continuous spectrum from ˜0.8 to ˜4.5 microm and is pumped by amplified nanosecond laser diode pulses. The SC laser uses ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fluoride fibers. The SC light source is all-fiber-integrated with no moving parts, operates at room temperature, and eliminates the need of mode-locked lasers. The time-averaged power of the SC is scalable up to 10.5 W by amplifying the pump pulses using cladding-pumped erbium/ytterbium co-doped fiber power amplifiers. SC has also been generated in silica fibers with spectrum extending to ˜3 microm and an average power up to 5.3 W. The SC laser system comprises an all-fiber-spliced high power pump laser system followed by nonlinear optical generation fibers, i.e. ZBLAN and silica fibers. The SC generation is initiated by breaking up the nanosecond diode pulses into femtosecond pulses through modulation instability, and the spectrum is then broadened through the interplay of self-phase modulation, parametric four-wave mixing, and stimulated Raman scattering. Theoretical simulations have been carried out to study the SC generation mechanism by numerically solving the generalized nonlinear Schrodinger equation. The SC long wavelength edge is limited by the intrinsic fiber material absorption, i.e. ˜3 microm in silica fibers and ˜4.5 microm in ZBLAN fibers, respectively. Mid-infrared absorption spectroscopy of the constituents of normal artery, e.g. endothelial cells and smooth muscle cells, and atherosclerotic plaques, e.g. adipose tissue, macrophages and foam cells, and selective ablation of lipid-rich tissues have also been demonstrated using the SC laser system.

  3. Laser rangefinders for autonomous intelligent cruise control systems

    Science.gov (United States)

    Journet, Bernard A.; Bazin, Gaelle

    1998-01-01

    THe purpose of this paper is to show to what kind of application laser range-finders can be used inside Autonomous Intelligent Cruise Control systems. Even if laser systems present good performances the safety and technical considerations are very restrictive. As the system is used in the outside, the emitted average output power must respect the rather low level of 1A class. Obstacle detection or collision avoidance require a 200 meters range. Moreover bad weather conditions, like rain or fog, ar disastrous. We have conducted measurements on laser rangefinder using different targets and at different distances. We can infer that except for cooperative targets low power laser rangefinder are not powerful enough for long distance measurement. Radars, like 77 GHz systems, are better adapted to such cases. But in case of short distances measurement, range around 10 meters, with a minimum distance around twenty centimeters, laser rangefinders are really useful with good resolution and rather low cost. Applications can have the following of white lines on the road, the target being easily cooperative, detection of vehicles in the vicinity, that means car convoy traffic control or parking assistance, the target surface being indifferent at short distances.

  4. Relay telescope for high power laser alignment system

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  5. Study and Development of a Laser Based Alignment System

    CERN Multimedia

    Stern, G

    2014-01-01

    CLIC (Compact Linear Collider) has tight requirements regarding pre-alignment of beam related components: 10 µm accuracy over a sliding window of 200 m along the 20 km of linac. To perform such an alignment, a new system is proposed combining laser beam as straight line reference and camera/shutter assemblies as sensors. The poster describes the alignment system and shows results regarding laser pointing stability with respect to time, shutter type, distance and environment. These results give a frame for future building and calibrating of sensors.

  6. Lessons Learned from the Advanced Topographic Laser Altimeter System

    Science.gov (United States)

    Garrison, Matt; Patel, Deepak; Bradshaw, Heather; Robinson, Frank; Neuberger, Dave

    2016-01-01

    The ICESat-2 Advanced Topographic Laser Altimeter System (ATLAS) instrument is an upcoming Earth Science mission focusing on the effects of climate change. The flight instrument passed all environmental testing at GSFC (Goddard Space Flight Center) and is now ready to be shipped to the spacecraft vendor for integration and testing. This presentation walks through the lessons learned from design, hardware, analysis and testing perspective. ATLAS lessons learned include general thermal design, analysis, hardware, and testing issues as well as lessons specific to laser systems, two-phase thermal control, and optical assemblies with precision alignment requirements.

  7. Laser Communication Demonstration System (LCDS) and future mobile satellite services

    Science.gov (United States)

    Chen, Chien-Chung; Wilhelm, Michael D.; Lesh, James R.

    1995-01-01

    The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth orbit. For future global satellite communication systems using intersatellite links, laser communications technology can offer reduced mass and power requirements and higher channel bandwidths without regulatory constraints. As currently envisioned, LCDS will consist of one or two orbiting laser communications terminals capable of demonstrating high data rate (greater than 750Mbps) transmission in a dynamic space environment. Two study teams led by Motorola and Ball Aerospace are currently in the process of conducting a Phase A/B mission definition study of LCDS under contracts with JPL/NASA. The studies consist of future application survey, concept and requirements definition, and a point design of the laser communications flight demonstration. It is planned that a single demonstration system will be developed based on the study results. The Phase A/B study is expected to be completed by the coming June, and the current results of the study are presented in this paper.

  8. The Injection Laser System on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, M; Burkhart, S; Cohen, S; Erbert, G; Heebner, J; Hermann, M; Jedlovec, D

    2006-12-13

    The National Ignition Facility (NIF) is currently the largest and most energetic laser system in the world. The main amplifiers are driven by the Injection Laser System comprised of the master oscillators, optical preamplifiers, temporal pulse shaping and spatial beam formatting elements and injection diagnostics. Starting with two fiber oscillators separated by up to a few angstroms, the pulse is phase modulated to suppress SBS and enhance spatial smoothing, amplified, split into 48 individual fibers, and then temporally shaped by an arbitrary waveform generator. Residual amplitude modulation induced in the preamplifiers from the phase modulation is also precompensated in the fiber portion of the system before it is injected into the 48 pre-amplifier modules (PAMs). Each of the PAMs amplifies the light from the 1 nJ fiber injection up to the multi-joule level in two stages. Between the two stages the pre-pulse is suppressed by 60 dB and the beam is spatially formatted to a square aperture with precompensation for the nonuniform gain profile of the main laser. The input sensor package is used to align the output of each PAM to the main laser and acquire energy, power, and spatial profiles for all shots. The beam transport sections split the beam from each PAM into four main laser beams (with optical isolation) forming the 192 beams of the NIF. Optical, electrical, and mechanical design considerations for long term reliability and availability will be discussed.

  9. Laser Soldering of Rat Skin Using a Controlled Feedback System

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Nourbakhsh

    2009-03-01

    Full Text Available Introduction: Laser tissue soldering using albumin and indocyanine green dye (ICG is an effective technique utilized in various surgical procedures. The purpose of this study was to perform laser soldering of rat skin under a feedback control system and compare the results with those obtained using standard sutures. Material and Methods: Skin incisions were made over eight rats’ dorsa, which were subsequently closed using different wound closure interventions in two groups: (a using a temperature controlled infrared detector or (b by suture. Tensile strengths were measured at 2, 5, 7 and 10 days post-incision. Histological examination was performed at the time of sacrifice. Results: Tensile strength results showed that during the initial days following the incisions, the tensile strengths of the sutured samples were greater than the laser samples. However, 10 days after the incisions, the tensile strengths of the laser soldered incisions were higher than the sutured cuts. Histopathological examination showed a preferred wound healing response in the soldered skin compared with the control samples. The healing indices of the laser soldered repairs (426 were significantly better than the control samples (340.5. Conclusion: Tissue feedback control of temperature and optical changes in laser soldering of skin leads to a higher tensile strength and better histological results and hence this method may be considered as an alternative to standard suturing.

  10. Laser beam shaping optical system design methods and their application in edge-emitting semiconductor laser-based LIDAR systems

    Science.gov (United States)

    Serkan, Mert

    LIDAR (Light Detection And Ranging) systems are employed for numerous applications such as remote sensing, military applications, optical data storage, display technology, and material processing. Furthermore, they are superior to other active remote sensing tools such as RADAR systems, considering their higher accuracy and more precise resolution due to their much shorter wavelengths and narrower beamwidth. Several types of lasers can be utilized as the radiation source of several LIDAR systems. Semiconductor laser-based LIDAR systems have several advantages such as low cost, compactness, broad range of wavelengths, and high PRFs (Pulse Repetition Frequency). However, semiconductor lasers have different origins and angles of divergence in the two transverse directions, resulting in the inherent astigmatism and elliptical beam shape. Specifically, elliptical beam shape is not desirable for several laser-based applications including LIDAR systems specifically designed to operate in the far-field region. In this dissertation, two mirror-based and two lens-based beam shapers are designed to circularize, collimate, and expand an edge-emitting semiconductor laser beam to a desired beam diameter for possible application in LIDAR systems. Additionally, most laser beams including semiconductor laser beams have Gaussian irradiance distribution. For applications that require uniform illumination of an extended target area, Gaussian irradiance distribution is undesirable. Therefore, a specific beam shaper is designed to transform the irradiance distribution from Gaussian to uniform in addition to circularizing, collimating, and expanding the semiconductor laser beam. For the design of beam shapers, aperture sizes of the surfaces are preset for desired power transmission and allowed diffraction level, surface parameters of the optical components and the distances between these surfaces are determined. Design equations specific to these beam shaping optical systems are

  11. Calibration technology in application of robot-laser scanning system

    Science.gov (United States)

    Ren, YongJie; Yin, ShiBin; Zhu, JiGui

    2012-11-01

    A system composed of laser sensor and 6-DOF industrial robot is proposed to obtain complete three-dimensional (3-D) information of the object surface. Suitable for the different combining ways of laser sensor and robot, a new method to calibrate the position and pose between sensor and robot is presented. By using a standard sphere with known radius as a reference tool, the rotation and translation matrices between the laser sensor and robot are computed, respectively in two steps, so that many unstable factors introduced in conventional optimization methods can be avoided. The experimental results show that the accuracy of the proposed calibration method can be achieved up to 0.062 mm. The calibration method is also implemented into the automated robot scanning system to reconstruct a car door panel.

  12. Erbium - doped fiber laser systems: Routes to chaos

    Directory of Open Access Journals (Sweden)

    Rubežić Vesna

    2014-01-01

    Full Text Available Erbium-doped fiber laser systems exhibit a large variety of complex dynamical behaviors, bifurcations and attractors. In this paper, the chaotic behavior which can be achieved under certain conditions in a laser system with erbium-doped fiber, is discussed. The chaos in this system occurs through several standard scenarios. In this paper, the simulation sequence of quasiperiodic, intermittent and period-doubling scenario transitions to chaos is shown. Quasiperiodic and intermittent transitions to chaos are shown on the example system with a single ring. The electro-optical modulator was applied to the system for modulating the loss in the cavity. We used the sinusoidal and rectangular signals for modulation. Generation of chaos is achieved by changing the parameters of signal for modulation. Period-doubling transition to chaos is illustrated in a system with two rings. Simulation results are shown in the time domain and phase space.

  13. Galvanometer beam-scanning system for laser fiber drawing.

    Science.gov (United States)

    Oehrle, R C

    1979-02-15

    A major difficulty in using a laser to draw optical fibers from a glass preform has been uniformally distributing the laser's energy around the melt zone. Several systems have evolved in recent years, but to date the most successful technique has been the off-axis rotating lens system (RLS). The inability of this device to structure efficiently and dynamically the heat zone longitudinally along the preform has restricted its use to preform of less than 8-mm diameter. A new technique reported here employs two orthogonal mounted mirrors, driven by galvanometers to distribute the laser energy around the preform. This system can be retrofitted into the RLS to replace the rotating lens element. The new system, the galvanometer scanning system (GSS), operates at ten times the rotational speed of the RLS and can instantaneously modify the melt zone. The ability of the GSS to enlarge the melt zone reduces the vaporization rate at the surface of the preform permitting efficient use of higher laser power. Experiments i dicate that fibers can be drawn from significantly larger preforms by using the expanded heat zone provided by the GSS.

  14. Nonablative lasers and nonlaser systems in dermatology: current status.

    Science.gov (United States)

    Sachdev, Mukta; Hameed, Sunaina; Mysore, Venkataram

    2011-01-01

    Nonablative lasers and nonlaser systems are newer systems used for skin rejuvenation, tightening, body sculpting, and scar remodeling. Different technologies such as lasers, Intense Pulsed Light (IPL), and radiofrequency have been introduced. Most nonablative laser systems emit light within the infrared portion of the electromagnetic spectrum (1000-1500 nm). At these wavelengths, absorption by superficial water containing tissue is relatively weak, thereby effecting deeper tissue penetration. A detailed understanding of the device being used is recommended. Nonablative technology have been used for several indications such as skin tightening, periorbital tissue tightening, treatment of nasolabial lines and jowl, body sculpting/remodeling, cellulite reduction, scar revision and remodeling and for the treatment of photodamaged skin. Nonablative laser and light modalities can be carried out in a physician treatment room or hospital setting or a nursing home with a small operation theater. The dermatologic consultation should include detailed assessment of the patient's skin condition and skin type. An informed consent is mandatory to protect the rights of the patient as well as the practitioner. All patients must have carefully taken preoperative and postoperative pictures. Depends on the indication, the area to be treated, the acceptable downtime for the desired correction, and to an extent the skin color. These lasers are mostly pain-free and tolerated well by patients but may require topical anesthesia. In most cases, topical cooling and numbing using icepacks is sufficient, even in an apprehensive patient. The nonablative lasers, light sources and radiofrequency systems are safe, even in darker skin types, and postoperative care is minimal. Proper postoperative care is important in avoiding complications. Post-treatment edema and redness settle in a few hours to a few days. Postoperative sun avoidance and use of sunscreen is mandatory.

  15. Nonablative lasers and nonlaser systems in dermatology: Current status

    Directory of Open Access Journals (Sweden)

    Mukta Sachdev

    2011-01-01

    Full Text Available Nonablative lasers and nonlaser systems are newer systems used for skin rejuvenation, tightening, body sculpting, and scar remodeling. Devices: Different technologies such as lasers, Intense Pulsed Light (IPL, and radiofrequency have been introduced. Most nonablative laser systems emit light within the infrared portion of the electromagnetic spectrum (1000-1500nm. At these wavelengths, absorption by superficial water containing tissue is relatively weak, thereby effecting deeper tissue penetration. A detailed understanding of the device being used is recommended. Indications: Nonablative technology have been used for several indications such as skin tightening, periorbital tissue tightening, treatment of nasolabial lines and jowl, body sculpting/remodeling, cellulite reduction, scar revision and remodeling and for the treatment of photodamaged skin. Facility: Nonablative laser and light modalities can be carried out in a physician treatment room or hospital setting or a nursing home with a small operation theater. Preoperative counseling and informed consent: The dermatologic consultation should include detailed assessment of the patient′s skin condition and skin type. An informed consent is mandatory to protect the rights of the patient as well as the practitioner. All patients must have carefully taken preoperative and postoperative pictures. Choice of the device and parameters: Depends on the indication, the area to be treated, the acceptable downtime for the desired correction, and to an extent the skin color. Anesthesia: These lasers are mostly pain-free and tolerated well by patients but may require topical anesthesia. In most cases, topical cooling and numbing using icepacks is sufficient, even in an apprehensive patient. Postoperative care: The nonablative lasers, light sources and radiofrequency systems are safe, even in darker skin types, and postoperative care is minimal. Proper postoperative care is important in avoiding

  16. Receiver Design, Performance Analysis, and Evaluation for Space-Borne Laser Altimeters and Space-to-Space Laser Ranging Systems

    Science.gov (United States)

    Davidson, Frederic M.; Sun, Xiaoli; Field, Christopher T.

    1996-01-01

    This progress report consists of two separate reports. The first one describes our work on the use of variable gain amplifiers to increase the receiver dynamic range of space borne laser altimeters such as NASA's Geoscience Laser Altimeter Systems (GLAS). The requirement of the receiver dynamic range was first calculated. A breadboard variable gain amplifier circuit was made and the performance was fully characterized. The circuit will also be tested in flight on board the Shuttle Laser Altimeter (SLA-02) next year. The second report describes our research on the master clock oscillator frequency calibration for space borne laser altimeter systems using global positioning system (GPS) receivers.

  17. Volatile-carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546

    Science.gov (United States)

    Kama, M.; Bruderer, S.; van Dishoeck, E. F.; Hogerheijde, M.; Folsom, C. P.; Miotello, A.; Fedele, D.; Belloche, A.; Güsten, R.; Wyrowski, F.

    2016-08-01

    Aims: The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with a similar age and disk mass, but different central stars: HD 100546 and TW Hya. Methods: We combine our recent detections of C0 in these disks with observations of other carbon reservoirs (CO, C+, C2H) and gas-mass and warm-gas tracers (HD, O0), as well as spatially resolved ALMA observations and the spectral energy distribution. The disks are modelled with the DALI 2D physical-chemical code. Stellar abundances for HD 100546 are derived from archival spectra. Results: Upper limits on HD emission from HD 100546 place an upper limit on the total disk mass of ≤0.1 M⊙. The gas-phase carbon abundance in the atmosphere of this warm Herbig disk is, at most, moderately depleted compared to the interstellar medium, with [C]/[H]gas = (0.1-1.5) × 10-4. HD 100546 itself is a λBoötis star, with solar abundances of C and O but a strong depletion of rock-forming elements. In the gas of the T Tauri disk TW Hya, both C and O are strongly underabundant, with [C]/[H]gas = (0.2-5.0) × 10-6 and C / O > 1. We discuss evidence that the gas-phase C and O abundances are high in the warm inner regions of both disks. Our analytical model, including vertical mixing and a grain size distribution, reproduces the observed [C]/[H]gas in the outer disk of TW Hya and allows to make predictions for other systems. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 093.C-0926, 093.F-0015, 077.D-0092, 084.A-9016, and 085.A-9027.Spectra and models are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A83

  18. 21 CFR 884.6200 - Assisted reproduction laser system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200 Section 884.6200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices §...

  19. Multifunction laser systems in clinical and resort practice

    OpenAIRE

    ZABULONOV, Yuriy; Vladimirov, Alexander; Chukhraiev, Nikolay; Elmehsenawi, Yousry; Zukow, Walery

    2016-01-01

    SHUPYKNATIONALMEDICALACADEMY OF POSTGRADUATE EDUCATION UKRAINIANSOCIETY OFPHYSICAL AND REHABILITATION MEDICINE RADOM UNIVERSITY       Yuriy Zabulonov, Alexander Vladimirov, Nikolay Chukhraiev, Yousry Elmehsenawi, Walery Zukow       MULTIFUNCTION LASER SYSTEMS IN CLINICAL AND RESORT PRACTICE   Edited by Yuriy Zabulonov, Alexander Vladimirov, Nikolay Chukhraiev, Yousry Elmehsenawi, Walery Zukow  ...

  20. Laser system for identification, tracking, and control of flying insects

    Science.gov (United States)

    Flying insects are common vectors for transmission of pathogens and inflict significant harm on humans in large parts of the developing world. Besides the direct impact to humans, these pathogens also cause harm to crops and result in agricultural losses. Here, we present a laser-based system that c...

  1. Benchmarking Advanced Control Algorithms for a Laser Scanner System

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Ordys, A.W.; Smillie, I.

    1996-01-01

    The paper describes tests performed on the laser scanner system toassess feasibility of modern control techniques in achieving a requiredperformance in the trajectory following problem. The two methods tested areQTR H-infinity and Predictive Control. The results are ilustated ona simulation example....

  2. Ultra-stable clock laser system development towards space applications

    Science.gov (United States)

    Świerad, Dariusz; Häfner, Sebastian; Vogt, Stefan; Venon, Bertrand; Holleville, David; Bize, Sébastien; Kulosa, André; Bode, Sebastian; Singh, Yeshpal; Bongs, Kai; Rasel, Ernst Maria; Lodewyck, Jérôme; Le Targat, Rodolphe; Lisdat, Christian; Sterr, Uwe

    2016-09-01

    The increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10-16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm3 and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm3. The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10-10/g, 5.8 × 10-10/g and 3.1 × 10-10/g, where g ≈ 9.8 m/s2 is the standard gravitational acceleration.

  3. X-ray Emission from Young Stars in the TW Hya Association

    Science.gov (United States)

    Brown, Alexander; Herczeg, Gregory J.; Ayres, Thomas R.; France, Kevin; Brown, Joanna M.

    2015-01-01

    The 9 Myr old TW Hya Association (TWA) is the nearest group (typical distances of ˜50 pc) of pre-main-sequence (PMS) stars with ages less than 10 Myr and contains stars with both actively accreting disks and debris disks. We have studied the coronal X-ray emission from a group of low mass TWA common proper motion binaries using the Chandra and Swift satellites. Our aim is to understand better their coronal properties and how high energy photons affect the conditions around young stars and their role in photo-exciting atoms, molecules and dust grains in circumstellar disks and lower density circumstellar gas. Once planet formation is underway, this emission influences protoplanetary evolution and the atmospheric conditions of the newly-formed planets. The X-ray properties for 7 individual stars (TWA 13A, TWA 13B, TWA 9A, TWA 9B, TWA 8A, TWA 8B, and TWA 7) and 2 combined binary systems (TWA 3AB and TWA 2AB) have been measured. All the stars with sufficient signal require two-component fits to their CCD-resolution X-ray spectra, typically with a dominant hot (~2 kev (25 MK)) component and a cooler component at ~0.4 keV (4 MK). The brighter sources all show significant X-ray variability (at a level of 50-100% of quiescence) over the course of 5-15 ksec observations due to flares. We present the X-ray properties for each of the stars and find that the coronal emission is in the super-saturated rotational domain.

  4. CW Yb:YAG LASER FOR PORTABLE MEASURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. M. Ivashko

    2014-01-01

    Full Text Available The theoretical and experimental results of longitudinally continuous-wave diode-pumped Yb:Y3Al5O12 (YAG laser performance for compact field-condition measuring systems were demonstrated. Optimization of laser setup in terms of operation condition in the range of -40 ˚С – +65 ˚С without active thermal stabilization was carried out. Using Yb (10 ат.%:YAG crystal with the length of 3 mm the maximal output power more than 2 W was obtained in the whole of temperature range.

  5. Femtosecond Synchronization of Laser Systems for the LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, John; /LBL, Berkeley; Doolittle, Lawrence; /LBL, Berkeley; Huang, Gang; /LBL, Berkeley; Staples, John; /LBL, Berkeley; Wilcox, Russell; /LBL, Berkeley; Arthur, John; /SLAC; Frisch, Josef; /SLAC; White, William; /SLAC

    2012-08-24

    The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system based on stabilized fiber links has been developed for the LCLS to provide this synchronization. Preliminary results show synchronization of the installed stabilized links at the sub-20-femtosecond level. We present details of the implementation at LCLS and potential for future development.

  6. Generation of sub-three-cycle, 16 TW light pulses by using noncollinear optical parametric chirped-pulse amplification.

    Science.gov (United States)

    Herrmann, Daniel; Veisz, Laszlo; Tautz, Raphael; Tavella, Franz; Schmid, Karl; Pervak, Vladimir; Krausz, Ferenc

    2009-08-15

    We present a two-stage noncollinear optical parametric chirped-pulse amplification system that generates 7.9 fs pulses containing 130 mJ of energy at an 805 nm central wavelength and 10 Hz repetition rate. These 16 TW light pulses are compressed to within 5% of their Fourier limit and are carefully characterized by the use of home-built pulse diagnostics. The contrast ratio before the main pulse has been measured as 10(-4), 10(-8), and 10(-11) at t=-3.3 ps, t=-5 ps, and t=-30 ps, respectively. This source allows for experiments in a regime of relativistic light-matter interactions and attosecond science.

  7. Numerical simulations of a diode laser BPH treatment system

    Energy Technology Data Exchange (ETDEWEB)

    Esch, V; London, R A; Papademetriou, S

    1999-02-23

    Numerical simulations are presented of the laser-tissue interaction of a diode laser system for treating benign prostate hyperplasia. The numerical model includes laser light transport, heat transport, cooling due to blood perfusion, thermal tissue damage, and enthalpy of tissue damage. Comparisons of the simulation results to clinical data are given. We report that a reasonable variation from a standard set of input data produces heating times which match those measured in the clinical trials. A general trend of decreasing damage volume with increasing heating time is described. We suggest that the patient-to- patient variability seen in the data can be explained by differences in fundamental biophysical properties such as the optical coefficients. Further work is identified, including the measurement and input to the model of several specific data parameters such as optical coefficients, blood perfusion cooling rate, and coagulation rates.

  8. Synchronous pulse generation in a multicavity fiber laser system

    Science.gov (United States)

    Gómez-Pavón, L. C.; Martí-Panameño, E.; Gómez-de la Fuente, O.; Luis-Ramos, A.

    2006-09-01

    We report the experimental synchronous pulse generation in a multicavity fiber laser system with two Erbium-doped fiber laser cavities. We have demonstrated that through the evanescent fields interaction between one cavity with active modulation and other one in continuous wave it is possible to generate more intense pulses in both cavities. Moreover, the synchronous pulse generation between cavities is achieved with an appropriate selection of pump intensity, modulation frequency and coupling ratio. We found that the pulse intensity is 2.5 times greater and the pulse duration lowers than a single Erbium-doper fiber laser. Furthermore, by means of the synchronous diagram we determined the synchronization strength in temporal pulse emission between cavities.

  9. The optimization of laser systems for photodynamic therapy of malignancies

    Science.gov (United States)

    Lim, Hyun S.; Lee, Sang Chan; Kim, Ju Ock

    2005-04-01

    In this paper, we optimized the PDT laser system to improve the therapy effects of malignancies. In order to optimizes, the variation of laser output and specific wavelength shift have to reduced. To improved the PDT therapy clincian require the diverse radiation mode which irradiate the tumor surface. Continuous wave mode that general application may causes tissue thermal damage not only to tumor tissue, but also to nomal tissue. Therefore, we suggested new technique for radiation method to improved PDT effects and prevented to the thermal effects for the tissue. In experimental we verified the stability of wavelength, laser output stability and proved the reduced thermal effects to the tissue using the pulse & burst radiation modes in vitro.

  10. Laser heated pedestal growth system commissioning and fiber processing

    Science.gov (United States)

    Buric, Michael; Yip, M. J.; Chorpening, Ben; Ohodnicki, Paul

    2016-05-01

    A new Laser Heated Pedestal Growth system was designed and fabricated using various aspects of effective legacy designs for the growth of single-crystal high-temperature-compatible optical fibers. The system is heated by a 100-watt, DC driven, CO2 laser with PID power control. Fiber diameter measurements are performed using a telecentric video system which identifies the molten zone and utilizes edge detection algorithms to report fiber-diameter. Beam shaping components include a beam telescope; along with gold-coated reflaxicon, turning, and parabolic focusing mirrors consistent with similar previous systems. The optical system permits melting of sapphire-feedstock up to 1.5mm in diameter for growth. Details regarding operational characteristics are reviewed and properties of single-crystal sapphire fibers produced by the system are evaluated. Aspects of the control algorithm efficacy will be discussed, along with relevant alternatives. Finally, some new techniques for in-situ processing making use of the laser-heating system are discussed. Ex-situ fiber modification and processing are also examined for improvements in fiber properties.

  11. LAND-BASED MOBILE LASER SCANNING SYSTEMS: A REVIEW

    Directory of Open Access Journals (Sweden)

    I. Puente

    2012-09-01

    Full Text Available Mobile mapping has been using various photogrammetric techniques for many years. In recent years, there has been an increase in the number of mobile mapping systems using laser scanners available in the market, partially because of the improvement in GNSS/INS performance for direct georeferencing. In this article, some of the most important land-based mobile laser scanning (MLS systems are reviewed. Firstly, the main characteristics of MLS systems vs. airborne (ALS and terrestrial laser scanning (TLS systems are compared. Secondly, a short overview of the mobile mapping technology is also provided so that the reader can fully grasp the complexity and operation of these devices. As we put forward in this paper, a comparison of different systems is briefly carried out regarding specifications provided by the manufacturers. Focuses on the current research are also addressed with emphasis on the practical applications of these systems. Most of them have been utilized for data collection on road infrastructures or building façades. This article shows that MLS technology is nowadays well established and proven, since the demand has grown to the point that there are several systems suppliers offering their products to satisfy this particular market.

  12. Land-Based Mobile Laser Scanning Systems: a Review

    Science.gov (United States)

    Puente, I.; González-Jorge, H.; Arias, P.; Armesto, J.

    2011-09-01

    Mobile mapping has been using various photogrammetric techniques for many years. In recent years, there has been an increase in the number of mobile mapping systems using laser scanners available in the market, partially because of the improvement in GNSS/INS performance for direct georeferencing. In this article, some of the most important land-based mobile laser scanning (MLS) systems are reviewed. Firstly, the main characteristics of MLS systems vs. airborne (ALS) and terrestrial laser scanning (TLS) systems are compared. Secondly, a short overview of the mobile mapping technology is also provided so that the reader can fully grasp the complexity and operation of these devices. As we put forward in this paper, a comparison of different systems is briefly carried out regarding specifications provided by the manufacturers. Focuses on the current research are also addressed with emphasis on the practical applications of these systems. Most of them have been utilized for data collection on road infrastructures or building façades. This article shows that MLS technology is nowadays well established and proven, since the demand has grown to the point that there are several systems suppliers offering their products to satisfy this particular market.

  13. Laser system for testing radiation imaging detector circuits

    Science.gov (United States)

    Zubrzycka, Weronika; Kasinski, Krzysztof

    2015-09-01

    Performance and functionality of radiation imaging detector circuits in charge and position measurement systems need to meet tight requirements. It is therefore necessary to thoroughly test sensors as well as read-out electronics. The major disadvantages of using radioactive sources or particle beams for testing are high financial expenses and limited accessibility. As an alternative short pulses of well-focused laser beam are often used for preliminary tests. There are number of laser-based devices available on the market, but very often their applicability in this field is limited. This paper describes concept, design and validation of laser system for testing silicon sensor based radiation imaging detector circuits. The emphasis is put on keeping overall costs low while achieving all required goals: mobility, flexible parameters, remote control and possibility of carrying out automated tests. The main part of the developed device is an optical pick-up unit (OPU) used in optical disc drives. The hardware includes FPGA-controlled circuits for laser positioning in 2 dimensions (horizontal and vertical), precision timing (frequency and number) and amplitude (diode current) of short ns-scale (3.2 ns) light pulses. The system is controlled via USB interface by a dedicated LabVIEW-based application enabling full manual or semi-automated test procedures.

  14. Test for optical systems in laser projection imaging for PCB

    Science.gov (United States)

    Qin, Ouyang; Zhou, Jinyun; Lei, Liang; Lin, Qinghua

    2010-11-01

    Projection imaging is one of the most important steps in the fabrication of Printed Circuit Board. In order to meet the increasing demand for higher resolution, speed and larger area of imaging, a novel Laser Projection Imaging (LPI) has been developed to take the place of the conventional Hg lamp exposure. We set up a system with resolution 10μm over large exposure area of 460mm×610mm on substrate materials. The system is available by the combination of three main parts: an XeF excimer laser with a wavelength of 351nm and single pulse energy of 120mJ, an illumination system with numerical aperture (NA) value of 0.02, and a double telecentric optical projection lens with NA value of 0.025. Such designs can theoretically meet the demand of actual lithography. However, experiments have shown that the propagation loss ratio of laser power from the light source to the substrate can be up to 50% or more so as to hardly achieve the expected results. In this paper, we present our results of experiments under different conditions on laser projection imaging equipment, and meanwhile, parameters such as gas lifetime, pulse repetition rate, exposure dose, as well as the optical lose of quartz microlens array are analyzed. Finally, we acquired the optimum exposure parameters.

  15. Backscattering measuring system for optimization of intravenous laser irradiation dose

    Science.gov (United States)

    Rusina, Tatyana V.; Popov, V. D.; Melnik, Ivan S.; Dets, Sergiy M.

    1996-11-01

    Intravenous laser blood irradiation as an effective method of biostimulation and physiotherapy becomes a more popular procedure. Optimal irradiation conditions for each patient are needed to be established individually. A fiber optics feedback system combined with conventional intravenous laser irradiation system was developed to control of irradiation process. The system consists of He-Ne laser, fiber optics probe and signal analyzer. Intravenous blood irradiation was performed in 7 healthy volunteers and 19 patients with different diseases. Measurements in vivo were related to in vitro blood irradiation which was performed in the same conditions with force-circulated venous blood. Comparison of temporal variations of backscattered light during all irradiation procedures has shown a strong discrepancy on optical properties of blood in patients with various health disorders since second procedure. The best cure effect was achieved when intensity of backscattered light was constant during at least five minutes. As a result, the optical irradiation does was considered to be equal 20 minutes' exposure of 3 mW He-Ne laser light at the end of fourth procedure.

  16. DSP-based multi-purpose control system for laser processing

    Institute of Scientific and Technical Information of China (English)

    U Tong-Hyok; ZHANG Guo-shun; XU Bao-zhong; GANG Bei; LI Cheng; WANG Meng

    2006-01-01

    A DSP-based control system for laser processing that enables the motion of laser beam in two dimensions,and the control of its power with PC or without PC is discussed. The operation and implementation of the control system along with the rapid processing of image data are presented. The purpose of the control system is to operate the laser equipments in such a manner that various programmable laser control signals are available for vector and bitmap processing of characters and pictures. This control system makes the laser processing more intelligent and flexible and can be used for welding, marking and engraving by lasers.

  17. Bifurcation and Chaos Control for Nonlinear Laser Systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In recent years, complexity science, including various bifurcations ,chaos and turbulence, has become a great challenge in various interdisciplinary fields. It promises to have a major impact on many aspects of nature science and engineering, even social and economic science. Candidates of complex system include coupled laser systems, accelerator-driven clean nuclear power system, neural networks, cellular automata, living organism, human brain, chemical reactions and economic systems. This new and challenging research and development area has in effect become a scientific inter-discipline itself, involving systems and control engineers, theoretical and experimental

  18. A Laser Stabilization System for Rydberg Atom Physics

    Science.gov (United States)

    2015-09-06

    A Laser Stabilization System for Rydberg Atom Physics We purchased 2 dual wavelength ultrastable ultralow expansion glass cavities along with optics...term locking could be achieved for 2 photon Rydberg atom excitation. Both systems were offset locked using a high bandwidth resonant electro-optic...Rydberg Atom Physics Report Title We purchased 2 dual wavelength ultrastable ultralow expansion glass cavities along with optics and electronics to

  19. Laser fusion power reactor system (LFPRS)

    Energy Technology Data Exchange (ETDEWEB)

    Kovacik, W. P.

    1977-12-19

    This report gives detailed information for each of the following areas: (1) reference concept description, (2) nuclear design, (3) structural design, (4) thermal and fluid systems design, (5) materials design and analysis, (6) reactor support systems and balance of plant, (7) instrumentation and control, (8) environment and safety, (9) economics assessment, and (10) development requirements. (MOW)

  20. Fibre laser based broadband THz imaging systems

    DEFF Research Database (Denmark)

    Eichhorn, Finn

    State-of-the-art optical fiber technology can contribute towards complex multi-element broadband terahertz imaging systems. Classical table-top terahertz imaging systems are generally limited to a single emitter/receiver pair, which constrains their imaging capability to tedious raster scanning...... imaging techniques. This thesis exhibits that fiber technology can improve the robustness and the flexibility of terahertz imaging systems both by the use of fiber-optic light sources and the employment of optical fibers as light distribution medium. The main focus is placed on multi-element terahertz...

  1. Control system for high power laser drilling workover and completion unit

    Energy Technology Data Exchange (ETDEWEB)

    Zediker, Mark S; Makki, Siamak; Faircloth, Brian O; DeWitt, Ronald A; Allen, Erik C; Underwood, Lance D

    2015-05-12

    A control and monitoring system controls and monitors a high power laser system for performing high power laser operations. The control and monitoring system is configured to perform high power laser operation on, and in, remote and difficult to access locations.

  2. The generation of high-quality, intense ion beams by ultra-intense lasers

    CERN Document Server

    Roth, M; Audebert, Patrick; Blazevic, A; Brambrink, E; Cowan, T E; Fuchs, J; Gauthier, J C; Geissel, M; Hegelich, M; Karsch, S; Meyer-Ter-Vehn, J; Ruhl, H; Schlegel, T; Stephens, R B

    2002-01-01

    Intense beams of protons and heavy ions have been observed in ultra-intense laser-solid interaction experiments. Thereby, a considerable fraction of the laser energy is transferred to collimated beams of energetic ions (e.g. up to 50 MeV protons; 100 MeV fluorine), which makes these beams highly interesting for various applications. Experimental results indicate a very short-pulse duration and an excellent beam quality, leading to beam intensities in the TW range. To characterize the beam quality and its dependence on laser parameters and target conditions we performed experiments using the 100 TW laser system at Laboratoire pour l'Utilisation des Lasers Intenses at the Ecole Polytechnique, France, with focused intensities exceeding 10 sup 1 sup 9 W cm sup - sup 2. We found a strong dependence on the target rear surface conditions allowing to tailor the ion beam by an appropriate target design. We also succeeded in the generation of heavy ion beams by suppressing the proton amount at the target surface. We wi...

  3. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems

    Directory of Open Access Journals (Sweden)

    Jaehoon Jung

    2015-05-01

    Full Text Available The Simultaneous Localization and Mapping (SLAM technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs: one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system’s trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach.

  4. Automatic control system design of laser interferometer

    Science.gov (United States)

    Lu, Qingjie; Li, Chunjie; Sun, Hao; Ren, Shaohua; Han, Sen

    2015-10-01

    There are a lot of shortcomings with traditional optical adjustment in interferometry, such as low accuracy, time-consuming, labor-intensive, uncontrollability, and bad repetitiveness, so we treat the problem by using wireless remote control system. Comparing to the traditional method, the effect of vibration and air turbulence will be avoided. In addition the system has some peculiarities of low cost, high reliability and easy operation etc. Furthermore, the switching between two charge coupled devices (CCDs) can be easily achieved with this wireless remote control system, which is used to collect different images. The wireless transmission is achieved by using Radio Frequency (RF) module and programming the controller, pulse width modulation (PWM) of direct current (DC) motor, real-time switching of relay and high-accuracy displacement control of FAULHABER motor are available. The results of verification test show that the control system has good stability with less than 5% packet loss rate, high control accuracy and millisecond response speed.

  5. Automated system for laser damage testing of coated optics

    Science.gov (United States)

    Ness, Dale C.; Streater, Alan D.

    2005-12-01

    Research Electro-Optics Inc. (REO) has recently developed a new laser damage testing facility for the purpose of optimizing process parameters for fabrication and coating of high-damage optics. It also enables full or sample qualification of optics with laser damage specifications. The fully automated laser damage testing system uses microscope photography for detection of damage and a 3 ns pulse length 1064 nm laser for irradiation of the sample. It can test and statistically analyze damage events from a large number of shots, enabling large area testing for low probability events. The system measures and maps sizes and locations of damage sites down to a few microns in diameter. The results are not subject to variations due to the human operator. For coatings deposited by ion beam sputtering, small defects (less than 20 microns) are found to be most prevalent at the fluences specified for small optics for the National Ignition Facility. The ability to measure and characterize small defects has improved REO's ability to optimize their processes for making coated optics with high damage thresholds. In addition to qualifying particular parts, the periodic testing also assures that equipment and processes remain optimized.

  6. Physico-technical background of metal vapor laser systems and their application in oncology

    Science.gov (United States)

    Armichev, A. V.; Ivanov, Andrei V.; Kazaryan, Mishik A.

    1996-01-01

    Some results of the copper and gold vapor lasers and of helium-cadmium lasers used in medical practice are presented. The most in medical use copper vapor laser is commonly applied for low-intensity laser therapy and endoscopic surgery. A universal capability of dye lasers oscillating in 600 - 670 red region for excitation of the preparates used in photodynamic therapy is demonstrated. The copper vapor lasers are shown also to effectively coagulate pre- tumor neoplasms. A new method of laser beams shaping fitted to tumor configuration basing on quantum optical systems including image brightness amplifiers is described. Variability of the irradiating beam contrast is displayed, including the contrast inversion. Possibilities of the copper vapor lasers use for tumors drugless phototherapy and the two-step and two-stage methods of the photodynamic therapy are discussed. Some Russian medical systems based on the copper vapor lasers and dye lasers pumped by them are specified in parameters.

  7. Water depth measurement using an airborne pulsed neon laser system

    Science.gov (United States)

    Hoge, F. E.; Swift, R. N.; Frederick, E. B.

    1980-01-01

    The paper presents the water depth measurement using an airborne pulsed neon laser system. The results of initial base-line field test results of NASA airborne oceanographic lidar in the bathymetry mode are given, with water-truth measurements of depth and beam attenuation coefficients by boat taken at the same time as overflights to aid in determining the system's operational performance. The nadir-angle tests and field-of-view data are presented; this laser bathymetry system is an improvement over prior models in that (1) the surface-to-bottom pulse waveform is digitally recorded on magnetic tape, and (2) wide-swath mapping data may be routinely acquired using a 30 deg full-angle conical scanner.

  8. Laser-driven shock acceleration of monoenergetic ion beams

    CERN Document Server

    Fiuza, F; Boella, E; Fonseca, R A; Silva, L O; Haberberger, D; Tochitsky, S; Gong, C; Mori, W B; Joshi, C

    2012-01-01

    We show that monoenergetic ion beams can be accelerated by moderate Mach number collisionless, electrostatic shocks propagating in a long scale-length exponentially decaying plasma profile. Strong plasma heating and density steepening produced by an intense laser pulse near the critical density can launch such shocks that propagate in the extended plasma at high velocities. The generation of a monoenergetic ion beam is possible due to the small and constant sheath electric field associated with the slowly decreasing density profile. The conditions for the acceleration of high-quality, energetic ion beams are identified through theory and multidimensional particle-in-cell simulations. The scaling of the ion energy with laser intensity shows that it is possible to generate $\\sim 200$ MeV proton beams with state-of-the-art 100 TW class laser systems.

  9. Components for monolithic fiber chirped pulse amplification laser systems

    Science.gov (United States)

    Swan, Michael Craig

    The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

  10. System and Method for Generating a Frequency Modulated Linear Laser Waveform

    Science.gov (United States)

    Pierrottet, Diego F. (Inventor); Petway, Larry B. (Inventor); Amzajerdian, Farzin (Inventor); Barnes, Bruce W. (Inventor); Lockard, George E. (Inventor); Hines, Glenn D. (Inventor)

    2017-01-01

    A system for generating a frequency modulated linear laser waveform includes a single frequency laser generator to produce a laser output signal. An electro-optical modulator modulates the frequency of the laser output signal to define a linear triangular waveform. An optical circulator passes the linear triangular waveform to a band-pass optical filter to filter out harmonic frequencies created in the waveform during modulation of the laser output signal, to define a pure filtered modulated waveform having a very narrow bandwidth. The optical circulator receives the pure filtered modulated laser waveform and transmits the modulated laser waveform to a target.

  11. System and Method for Generating a Frequency Modulated Linear Laser Waveform

    Science.gov (United States)

    Pierrottet, Diego F. (Inventor); Petway, Larry B. (Inventor); Amzajerdian, Farzin (Inventor); Barnes, Bruce W. (Inventor); Lockard, George E. (Inventor); Hines, Glenn D. (Inventor)

    2014-01-01

    A system for generating a frequency modulated linear laser waveform includes a single frequency laser generator to produce a laser output signal. An electro-optical modulator modulates the frequency of the laser output signal to define a linear triangular waveform. An optical circulator passes the linear triangular waveform to a band-pass optical filter to filter out harmonic frequencies created in the waveform during modulation of the laser output signal, to define a pure filtered modulated waveform having a very narrow bandwidth. The optical circulator receives the pure filtered modulated laser waveform and transmits the modulated laser waveform to a target.

  12. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    Science.gov (United States)

    Scisciò, M.; Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Papaphilippou, Y.; Antici, P.

    2016-03-01

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  13. Parametric study of transport beam lines for electron beams accelerated by laser-plasma interaction

    Energy Technology Data Exchange (ETDEWEB)

    Scisciò, M.; Antici, P., E-mail: patrizio.antici@polytechnique.edu [INFN-RM1 and SBAI, Università di Roma “La Sapienza,” Via Scarpa 16, 00161 Roma (Italy); INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada); Lancia, L.; Migliorati, M.; Mostacci, A.; Palumbo, L. [INFN-RM1 and SBAI, Università di Roma “La Sapienza,” Via Scarpa 16, 00161 Roma (Italy); Papaphilippou, Y. [CERN, CH 1211 Geneva 23 (Switzerland)

    2016-03-07

    In the last decade, laser-plasma acceleration of high-energy electrons has attracted strong attention in different fields. Electrons with maximum energies in the GeV range can be laser-accelerated within a few cm using multi-hundreds terawatt (TW) lasers, yielding to very high beam currents at the source (electron bunches with up to tens-hundreds of pC in a few fs). While initially the challenge was to increase the maximum achievable electron energy, today strong effort is put in the control and usability of these laser-generated beams that still lack of some features in order to be used for applications where currently conventional, radio-frequency (RF) based, electron beam lines represent the most common and efficient solution. Several improvements have been suggested for this purpose, some of them acting directly on the plasma source, some using beam shaping tools located downstream. Concerning the latter, several studies have suggested the use of conventional accelerator magnetic devices (such as quadrupoles and solenoids) as an easy implementable solution when the laser-plasma accelerated beam requires optimization. In this paper, we report on a parametric study related to the transport of electron beams accelerated by laser-plasma interaction, using conventional accelerator elements and tools. We focus on both, high energy electron beams in the GeV range, as produced on petawatt (PW) class laser systems, and on lower energy electron beams in the hundreds of MeV range, as nowadays routinely obtained on commercially available multi-hundred TW laser systems. For both scenarios, our study allows understanding what are the crucial parameters that enable laser-plasma accelerators to compete with conventional ones and allow for a beam transport. We show that suitable working points require a tradeoff-combination between low beam divergence and narrow energy spread.

  14. Unstable normal modes of low T/W dynamical instabilities in differentially rotating stars

    CERN Document Server

    Saijo, Motoyuki

    2016-01-01

    We investigate the nature of low T/W dynamical instabilities in differentially rotating stars by means of linear perturbation. Here, T and W represent rotational kinetic energy and the gravitational binding energy of the star. This is the first attempt to investigate low T/W dynamical instabilities as a complete set of the eigenvalue problem. Our equilibrium configuration has "constant" specific angular momentum distribution, which potentially contains a singular solution in the perturbed enthalpy at corotation radius in linear perturbation. We find the unstable normal modes of differentially rotating stars by solving the eigenvalue problem along the equatorial plane of the star, imposing the regularity condition on the center and the vanished enthalpy at the oscillating equatorial surface. We find that the existing pulsation modes become unstable due to the existence of the corotation radius inside the star. The feature of the unstable mode eigenfrequency and its eigenfunction in the linear analysis roughly ...

  15. Charged-particle acceleration through laser irradiation of thin foils at Prague Asterix Laser System

    Science.gov (United States)

    Torrisi, Lorenzo; Cutroneo, Maria; Cavallaro, Salvatore; Musumeci, Paolo; Calcagno, Lucia; Wolowski, Jerzy; Rosinski, Marcin; Zaras-Szydlowska, Agnieszka; Ullschmied, Jiri; Krousky, Eduard; Pfeifer, Miroslav; Skala, Jiri; Velyhan, Andreiy

    2014-05-01

    Thin foils, 0.5-50 μm in thickness, have been irradiated in vacuum at Prague Asterix Laser System in Prague using 1015-16 W cm-2 laser intensity, 1315 nm wavelength, 300 ps pulse duration and different focal positions. Produced plasmas from metals and polymers films have been monitored in the forward and backward directions. Ion and electron accelerations have been investigated by using Thomson parabola spectrometer, x-ray streak camera, ion collectors and SiC semiconductor detectors, the latter employed in time-of-flight configuration. Ion acceleration up to about 3 MeV per charge state was measured in the forward direction. Ion and electron emissions were detected at different angles as a function of the irradiation conditions.

  16. Compact beam transport system for free-electron lasers driven by a laser plasma accelerator

    Science.gov (United States)

    Liu, Tao; Zhang, Tong; Wang, Dong; Huang, Zhirong

    2017-02-01

    Utilizing laser-driven plasma accelerators (LPAs) as a high-quality electron beam source is a promising approach to significantly downsize the x-ray free-electron laser (XFEL) facility. A multi-GeV LPA beam can be generated in several-centimeter acceleration distance, with a high peak current and a low transverse emittance, which will considerably benefit a compact FEL design. However, the large initial angular divergence and energy spread make it challenging to transport the beam and realize FEL radiation. In this paper, a novel design of beam transport system is proposed to maintain the superior features of the LPA beam and a transverse gradient undulator (TGU) is also adopted as an effective energy spread compensator to generate high-brilliance FEL radiation. Theoretical analysis and numerical simulations are presented based on a demonstration experiment with an electron energy of 380 MeV and a radiation wavelength of 30 nm.

  17. 投影机 爱普生EMP-TW20

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    在爱普生的EMP-TW系列家用投影机中,EMP-TW20是最新的一款低端产品。在外观方面,它仍保持了爱普生EMP-TW投影机简浩高质感的设计风格,而且乳白色的机身可以很容易地与家居环境融合.

  18. Development of a YAG laser system for the edge Thomson scattering system in ITER.

    Science.gov (United States)

    Hatae, T; Yatsuka, E; Hayashi, T; Yoshida, H; Ono, T; Kusama, Y

    2012-10-01

    A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).

  19. Laser Based Information Systems (Selected Pages),

    Science.gov (United States)

    1986-05-22

    from the object; 10- turning mirror; 11- Cardan " suspension; 12-- servodrive; 13- periscope; 14- system for manual control- 15- dissector; 16...automatic tracing. The controlled mirror is mounted in a cardan suspension the axes of which are driven by dc servomotors. With the axes...gyroscope with the velocity of 100-500 deg/h arises because of the friction in the pivots of the Cardan 120 -" 1 support and imperfect balancing. In

  20. Kinematic and Dynamic Analysis of New Polar Positioning System Dedicated to Mechatronic Laser Glass Engraving System

    Directory of Open Access Journals (Sweden)

    Trochimczuk R.

    2014-11-01

    Full Text Available Analytical formulas describing the kinematics and dynamics of a multibody system of a new polar positioning system dedicated to mechatronic laser glass or other transparent dielectrics engraving system will be presented in this work. The analytical results will become in the later stages of the research the basis of numerical simulations. They will optimize the proposed solution of the positioning system.

  1. Measurement and compensation schemes for the pulse front distortion of ultra-intensity ultra-short laser pulses

    Science.gov (United States)

    Wu, Fenxiang; Xu, Yi; Yu, Linpeng; Yang, Xiaojun; Li, Wenkai; Lu, Jun; Leng, Yuxin

    2016-11-01

    Pulse front distortion (PFD) is mainly induced by the chromatic aberration in femtosecond high-peak power laser systems, and it can temporally distort the pulse in the focus and therefore decrease the peak intensity. A novel measurement scheme is proposed to directly measure the PFD of ultra-intensity ultra-short laser pulses, which can work not only without any extra struggle for the desired reference pulse, but also largely reduce the size of the required optical elements in measurement. The measured PFD in an experimental 200TW/27fs laser system is in good agreement with the calculated result, which demonstrates the validity and feasibility of this method effectively. In addition, a simple compensation scheme based on the combination of concave lens and parabolic lens is also designed and proposed to correct the PFD. Based on the theoretical calculation, the PFD of above experimental laser system can almost be completely corrected by using this compensator with proper parameters.

  2. Development of copper bromide laser master oscillator power amplifier system

    Indian Academy of Sciences (India)

    G N Tiwari; R K Mishra; R Khare; S V Nakhe

    2014-02-01

    Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head.

  3. A Laser-Based Vision System for Weld Quality Inspection

    Science.gov (United States)

    Huang, Wei; Kovacevic, Radovan

    2011-01-01

    Welding is a very complex process in which the final weld quality can be affected by many process parameters. In order to inspect the weld quality and detect the presence of various weld defects, different methods and systems are studied and developed. In this paper, a laser-based vision system is developed for non-destructive weld quality inspection. The vision sensor is designed based on the principle of laser triangulation. By processing the images acquired from the vision sensor, the geometrical features of the weld can be obtained. Through the visual analysis of the acquired 3D profiles of the weld, the presences as well as the positions and sizes of the weld defects can be accurately identified and therefore, the non-destructive weld quality inspection can be achieved. PMID:22344308

  4. A frequency-doubled, pulsed laser system for rubidium manipulation

    CERN Document Server

    Dingjan, J; Beugnon, J; Jones, M P A; Bergamini, S; Messin, G; Browaeys, A; Grangier, P

    2005-01-01

    We have constructed a pulsed laser system for the manipulation of cold Rb atoms. The system combines optical telecommunications components and frequency doubling to generate light at 780 nm. Using a fast, fibre-coupled intensity modulator, output from a continuous laser diode is sliced into pulses with a length between 1.3 and 6.1 ns and a repetition frequency of 5 MHz. These pulses are amplified using an erbium-doped fibre amplifier, and frequency-doubled in a periodically poled lithium niobate crystal, yielding a peak power up to 12 W. Using the resulting light at 780 nm, we demonstrate Rabi oscillations on the F = 2 F=3-transition of a single 87Rb atom.

  5. Optimization of beam transformation system for laser-diode bars.

    Science.gov (United States)

    Yu, Junhong; Guo, Linhui; Wu, Hualing; Wang, Zhao; Gao, Songxin; Wu, Deyong

    2016-08-22

    An optimized beam transformation system (BTS) is proposed to improve the beam quality of laser-diode bars. Through this optimized design, the deterioration of beam quality after the BTS can be significantly reduced. Both the simulation and experimental results demonstrate that the optimized system enables the beam quality of a mini-bar (9 emitters) approximately equal to 5.0 mm × 3.6 mrad in the fast-axis and slow-axis. After beam shaping by the optimized BTS, the laser-diode beam can be coupled into a 100 μm core, 0.15 numerical aperture (NA) fiber with an output power of over 100 W and an electric-optical efficiency of 46.8%.

  6. Model JC-1 Laser System for Monitoring Atmospheric Pollution,

    Science.gov (United States)

    2007-11-02

    differential absorption mode atmospheric pollution laser monitoring system, in which a phase locking technique and single board computer are used for...amplification 1 3. synchronous demodulation 2 4. phase locking amplification 2 5. single board computer 6. function logging Instrument 7. oscillator...were then fed into a DBJ-Z80 single - board computer to undergo a multiple averaging process before going through functional operation, and were logged

  7. Qualification and issues with space flight laser systems and components

    Science.gov (United States)

    Ott, Melanie N.; Coyle, D. B.; Canham, John S.; Leidecker, Henning W., Jr.

    2006-02-01

    The art of flight quality solid-state laser development is still relatively young, and much is still unknown regarding the best procedures, components, and packaging required for achieving the maximum possible lifetime and reliability when deployed in the harsh space environment. One of the most important issues is the limited and unstable supply of quality, high power diode arrays with significant technological heritage and market lifetime. Since Spectra Diode Labs Inc. ended their involvement in the pulsed array business in the late 1990's, there has been a flurry of activity from other manufacturers, but little effort focused on flight quality production. This forces NASA, inevitably, to examine the use of commercial parts to enable space flight laser designs. System-level issues such as power cycling, operational derating, duty cycle, and contamination risks to other laser components are some of the more significant unknown, if unquantifiable, parameters that directly effect transmitter reliability. Designs and processes can be formulated for the system and the components (including thorough modeling) to mitigate risk based on the known failures modes as well as lessons learned that GSFC has collected over the past ten years of space flight operation of lasers. In addition, knowledge of the potential failure modes related to the system and the components themselves can allow the qualification testing to be done in an efficient yet, effective manner. Careful test plan development coupled with physics of failure knowledge will enable cost effect qualification of commercial technology. Presented here will be lessons learned from space flight experience, brief synopsis of known potential failure modes, mitigation techniques, and options for testing from the system level to the component level.

  8. Passive evaporation-condensation system for laser cooling

    Directory of Open Access Journals (Sweden)

    Gershuni A. N.

    2012-04-01

    Full Text Available A special heat pipe for ensuring the thermal regime of the active element of an optical quantum generator (laser under heat sink by radiation has been developed. It is shown that under the simulated fuel element power of 50 W wall temperature in the heat pipe heating zone does not exceed 30°C, and the emergency heating prevents deep freezing of the entire system in the absence of heat generation of the object itself.

  9. Advanced wavefront measurement and analysis of laser system modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, C.R.; Auerback, J.M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    High spatial resolution measurements of the reflected or transmitted wavefronts of large aperture optical components used in high peak power laser systems is now possible. These measurements are produced by phase shifting interferometry. The wavefront data is in the form of 3-D phase maps that reconstruct the wavefront shape. The emphasis of this work is on the characterization of wavefront features in the mid-spatial wavelength range (from 0.1 to 10.0 mm) and has been accomplished for the first time. Wavefront structure from optical components with spatial wavelengths in this range are of concern because their effects in high peak power laser systems. At high peak power, this phase modulation can convert to large magnitude intensity modulation by non-linear processes. This can lead to optical damage. We have developed software to input the measured phase map data into beam propagation codes in order to model this conversion process. We are analyzing this data to: (1) Characterize the wavefront structure produced by current optical components, (2) Refine our understanding of laser system performance, (3) Develop a database from which future optical component specifications can be derived.

  10. Method and system for homogenizing diode laser pump arrays

    Energy Technology Data Exchange (ETDEWEB)

    Bayramian, Andrew James

    2016-05-03

    An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

  11. The evolution of the laser: A systems perspective on science, technology and society

    Science.gov (United States)

    Deruiter, Willem

    The evolution of laser technology is addressed, and an attempt is made to correlate this evolution to the macrosociological theory of Juergen Habermas. The economic and social consequences of innovations are evaluated. Different laser applications are described. The evolution of the semiconductor laser is discussed. The evolution of optical telecommunication systems is outlined. The Habermas theory of communicative action, focussing on the theoretical distinction between 'system' and 'lifeworld,' is treated. The modified theory of Habermas is applied to the evolution of the laser. The embedding of a number of laser applications in the social context is discussed: laser isotope separation, compact disc players, and the Strategic Defense Initiative.

  12. Shielding design for a laser-accelerated proton therapy system.

    Science.gov (United States)

    Fan, J; Luo, W; Fourkal, E; Lin, T; Li, J; Veltchev, I; Ma, C-M

    2007-07-07

    In this paper, we present the shielding analysis to determine the necessary neutron and photon shielding for a laser-accelerated proton therapy system. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. A special particle selection and collimation device is needed to generate desired proton beams for energy- and intensity-modulated proton therapy. A great number of unwanted protons and even more electrons as a side-product of laser acceleration have to be stopped by collimation devices and shielding walls, posing a challenge in radiation shielding. Parameters of primary particles resulting from the laser-target interaction have been investigated by particle-in-cell simulations, which predicted energy spectra with 300 MeV maximum energy for protons and 270 MeV for electrons at a laser intensity of 2 x 10(21) W cm(-2). Monte Carlo simulations using FLUKA have been performed to design the collimators and shielding walls inside the treatment gantry, which consist of stainless steel, tungsten, polyethylene and lead. A composite primary collimator was designed to effectively reduce high-energy neutron production since their highly penetrating nature makes shielding very difficult. The necessary shielding for the treatment gantry was carefully studied to meet the criteria of head leakage shield neutrons and an outer layer of lead was used to reduce photon dose from neutron capture and electron bremsstrahlung. It is shown that the two-layer shielding design with 10-12 cm thick polyethylene and 4 cm thick lead can effectively absorb the unwanted particles to meet the shielding requirements.

  13. Shielding design for a laser-accelerated proton therapy system

    Science.gov (United States)

    Fan, J.; Luo, W.; Fourkal, E.; Lin, T.; Li, J.; Veltchev, I.; Ma, C.-M.

    2007-07-01

    In this paper, we present the shielding analysis to determine the necessary neutron and photon shielding for a laser-accelerated proton therapy system. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. A special particle selection and collimation device is needed to generate desired proton beams for energy- and intensity-modulated proton therapy. A great number of unwanted protons and even more electrons as a side-product of laser acceleration have to be stopped by collimation devices and shielding walls, posing a challenge in radiation shielding. Parameters of primary particles resulting from the laser-target interaction have been investigated by particle-in-cell simulations, which predicted energy spectra with 300 MeV maximum energy for protons and 270 MeV for electrons at a laser intensity of 2 × 1021 W cm-2. Monte Carlo simulations using FLUKA have been performed to design the collimators and shielding walls inside the treatment gantry, which consist of stainless steel, tungsten, polyethylene and lead. A composite primary collimator was designed to effectively reduce high-energy neutron production since their highly penetrating nature makes shielding very difficult. The necessary shielding for the treatment gantry was carefully studied to meet the criteria of head leakage shield neutrons and an outer layer of lead was used to reduce photon dose from neutron capture and electron bremsstrahlung. It is shown that the two-layer shielding design with 10-12 cm thick polyethylene and 4 cm thick lead can effectively absorb the unwanted particles to meet the shielding requirements.

  14. Synchronization control for ultrafast laser parallel microdrilling system

    Science.gov (United States)

    Zhai, Zhongsheng; Kuang, Zheng; Ouyang, Jinlei; Liu, Dun; Perrie, Walter; Edwardson, Stuart P.; Dearden, Geoff

    2014-11-01

    Ultrafast lasers, emitting ultra-short pulses of light, generally of the order of femtoseconds to ten picoseconds, are widely used in micro-processing with the advantage of very little thermal damage. Parallel micro-processing is seen significant developments in laser fabrication, thanking to the spatial light modulator (SLM) which can concert single beam to multiple beams through computer generate holograms (CGHs). However, without synchronization control, on the conditions of changing different holograms or processing on large area beyond scanning galvo's ability, the fabrication will be interrupted constantly for changing holograms and moving the stages. Therefore, synchronization control is very important to improve the convenience and application of parallel micro-processing. A synchronization control method, carried out through two application software: SAMLight (or WaveRunner) and Labview, is presented in this paper. SAMLight is used to control the laser and the scanning galvo to implement microprocessing, and the developed program with Labview is used to control the SLM and motion stages. The synchronization signals, transmitted between the two software, are utilized by a National Instruments (NI) device USB-6008. Using optimal control methods, the synchronized system can easily and automatically accomplish complicated fabrications with minimum time. A multi-drilling application is provided to verify the affectivity of the synchronized control method. It uses multiple annular beams, generated by superimposing multi-beam CGH onto a diffractive axicon CGH, to drill multiple holes at one time, and it can automatically finish different patterns based on synchronization control. This drilling way is an optical trepanning and it avoids huge laser energy waste with attenuation. The multi-beam CGHs, generated by the Grating and Lens algorithm, are different for different patterns. The processing is over 200 times faster than traditional mechanical trepanning

  15. Control electronics for a multi-laser/multi-detector scanning system

    Science.gov (United States)

    Kennedy, W.

    1980-01-01

    The Mars Rover Laser Scanning system uses a precision laser pointing mechanism, a photodetector array, and the concept of triangulation to perform three dimensional scene analysis. The system is used for real time terrain sensing and vision. The Multi-Laser/Multi-Detector laser scanning system is controlled by a digital device called the ML/MD controller. A next generation laser scanning system, based on the Level 2 controller, is microprocessor based. The new controller capabilities far exceed those of the ML/MD device. The first draft circuit details and general software structure are presented.

  16. Hybrid laser-beam-shaping system for rotatable dual beams with long depth of focus

    Science.gov (United States)

    Chou, Fu-Lung; Chen, Cheng-Huan; Lin, Yu-Chung; Lin, Mao-Chi

    2016-08-01

    A laser processing system consisting of two diffractive elements and one refractive element is proposed enabling a Gaussian laser beam to be transformed into two beams with a depth of focus of up to 150 µm and focal spot smaller than 5 µm. For specific laser processing, the two beams are rotatable when the beam-splitting diffractive element is rotated. The overall system is versatile for laser cutting and drilling.

  17. Laser vision based adaptive fill control system for TIG welding

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The variation of joint groove size during tungsten inert gas (TIG) welding will result in the non-uniform fill of deposited metal. To solve this problem, an adaptive fill control system was developed based on laser vision sensing. The system hardware consists of a modular development kit (MDK) as the real-time image capturing system, a computer as the controller, a D/A conversion card as the interface of controlled variable output, and a DC TIG welding system as the controlled device. The system software is developed and the developed feature extraction algorithm and control strategy are of good accuracy and robustness. Experimental results show that the system can implement adaptive fill of melting metal with high stability, reliability and accuracy. The groove is filled well and the quality of the weld formation satisfies the relevant industry criteria.

  18. Detecting Topological Defect Dark Matter Using Coherent Laser Ranging System.

    Science.gov (United States)

    Yang, Wanpeng; Leng, Jianxiao; Zhang, Shuangyou; Zhao, Jianye

    2016-07-08

    In the last few decades, optical frequency combs with high intensity, broad optical bandwidth, and directly traceable discrete wavelengths have triggered rapid developments in distance metrology. However, optical frequency combs to date have been limited to determine the absolute distance to an object (such as satellite missions). We propose a scheme for the detection of topological defect dark matter using a coherent laser ranging system composed of dual-combs and an optical clock via nongravitational signatures. The dark matter field, which comprises a defect, may interact with standard model particles, including quarks and photons, resulting in the alteration of their masses. Thus, a topological defect may function as a dielectric material with a distinctive frequency-depend index of refraction, which would cause the time delay of a periodic extraterrestrial or terrestrial light. When a topological defect passes through the Earth, the optical path of long-distance vacuum path is altered, this change in optical path can be detected through the coherent laser ranging system. Compared to continuous wavelength(cw) laser interferometry methods, dual-comb interferometry in our scheme excludes systematic misjudgement by measuring the absolute optical path length.

  19. Quality Metrics and Reliability Analysis of Laser Communication System

    Directory of Open Access Journals (Sweden)

    A. Arockia Bazil Raj

    2016-03-01

    Full Text Available Beam wandering is the main cause for major power loss in laser communication. To analyse this prerequisite at our environment, a 155 Mbps data transmission experimental setup is built with necessary optoelectronic components for the link range of 0.5 km at an altitude of 15.25 m. A neuro-controller is developed inside the FPGA and used to stabilise the received beam at the centre of detector plane. The Q-factor and bit error rate variation profiles are calculated using the signal statistics obtained from the eye-diagram. The performance improvements on the laser communication system due to the incorporation of beam wandering mitigation control are investigated and discussed in terms of various communication quality assessment key parameters.Defence Science Journal, Vol. 66, No. 2, March 2016, pp. 175-185, DOI: http://dx.doi.org/10.14429/dsj.66.9707

  20. Error analysis for a laser differential confocal radius measurement system.

    Science.gov (United States)

    Wang, Xu; Qiu, Lirong; Zhao, Weiqian; Xiao, Yang; Wang, Zhongyu

    2015-02-10

    In order to further improve the measurement accuracy of the laser differential confocal radius measurement system (DCRMS) developed previously, a DCRMS error compensation model is established for the error sources, including laser source offset, test sphere position adjustment offset, test sphere figure, and motion error, based on analyzing the influences of these errors on the measurement accuracy of radius of curvature. Theoretical analyses and experiments indicate that the expanded uncertainty of the DCRMS is reduced to U=0.13  μm+0.9  ppm·R (k=2) through the error compensation model. The error analysis and compensation model established in this study can provide the theoretical foundation for improving the measurement accuracy of the DCRMS.

  1. Scanning laser system to determine the corneal shape

    Science.gov (United States)

    Ascanio, Gabriel; Caballero-Ruiz, Alberto; Ruiz-Huerta, Leopoldo; Gonzalez-Cardel, Mario; Diaz-Uribe, Rufino

    2005-07-01

    The development and tests of a scanning system to be used to determine the corneal topography with the laser deflectometry method are presented. In this equipment, a He-Ne laser beam scans the cornea by describing a spiral trajectory generated by two components: radial and angular. The first component is produced by the displacement of a plane mirror moved by a linear pneumatic actuator. The second component is produced by passing the beam through a Dove prism which is rotating by means of a belt drive coupled to a high-speed electric motor. Tests were first performed by analyzing both components independently and then they were characterized by combining the two components. Results are discussed and compared to those of an earlier cited work.

  2. COHERENT LIDAR SYSTEM BASED ON A SEMICONDUCTOR LASER AND AMPLIFIER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a compact, reliable and low-cost coherent LIDAR (Light Detection And Ranging) system for remote wind-speed determination, determination of particle concentration, and/or temperature based on an all semiconductor light source and related methods. The present...... invention provides a coherent LIDAR system comprising a semiconductor laser for emission of a measurement beam of electromagnetic radiation directed towards a measurement volume for illumination of particles in the measurement volume, a reference beam generator for generation of a reference beam, a detector...

  3. Laser system for identification, tracking, and control of flying insects.

    Science.gov (United States)

    Mullen, Emma R; Rutschman, Phillip; Pegram, Nathan; Patt, Joseph M; Adamczyk, John J; Johanson, 3ric

    2016-05-30

    Flying insects are common vectors for transmission of pathogens and inflict significant harm to humans and agricultural production in many parts of the world. We present proof of principle for an optical system capable of highly specific vector control. This system utilizes a combination of optical sources, detectors, and sophisticated software to search, detect, and identify flying insects in real-time, with the capability of eradication using a lethal laser pulse. We present data on two insect species to show species distinction; Diaphorina citri, a vector of the causal agent of citrus greening disease, and Anopheles stephensi, a malaria vector.

  4. The Intelligent Measuring Sub-system in the Computer Integrated and Flexible Laser Processing System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on the computer integrated and flexible laser p rocessing system, we developed an intelligent measuring sub-system. A novel mod el has been built to compensate the deviations of the main frame-structure, and a laser tracker system is applied to calibrate the accuracy of the system. Anal yzing the characteristics of all kind surfaces of automobile outer penal moulds and dies, the surface and border to be measured and processed are classified int o four types. A 2-D adaptive measuring method based ...

  5. Experimental capabilities of 0.4 PW, 1 shot/min Scarlet laser facility for high energy density science.

    Science.gov (United States)

    Poole, P L; Willis, C; Daskalova, R L; George, K M; Feister, S; Jiang, S; Snyder, J; Marketon, J; Schumacher, D W; Akli, K U; Van Woerkom, L; Freeman, R R; Chowdhury, E A

    2016-06-10

    We report on the recently completed 400 TW upgrade to the Scarlet laser at The Ohio State University. Scarlet is a Ti:sapphire-based ultrashort pulse system that delivers >10  J in 30 fs pulses to a 2 μm full width at half-maximum focal spot, resulting in intensities exceeding 5×1021  W/cm2. The laser fires at a repetition rate of once per minute and is equipped with a suite of on-demand and on-shot diagnostics detailed here, allowing for rapid collection of experimental statistics. As part of the upgrade, the entire laser system has been redesigned to facilitate consistent, characterized high intensity data collection at high repetition rates. The design and functionality of the laser and target chambers are described along with initial data from commissioning experimental shots.

  6. An all-solid state laser system for the laser ion sources RILIS and in-source laser spectroscopy of astatine at ISOLDE/CERN

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, Sebastian

    2012-09-24

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at CERN/ISOLDE by the addition of an all-solid state tunable titanium:sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE/CERN and at ISAC/TRIUMF radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  7. An all-solid state laser system for the laser ion source RILIS and in-source laser spectroscopy of astatine at ISOLDE, CERN

    CERN Document Server

    Rothe, Sebastian; Nörtershäuser, W

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at ISOLDE, CERN, by the addition of an all-solid state tuneable titanium: sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE, CERN, and at ISAC, TRIUMF, radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  8. High-sensitive scanning laser magneto-optical imaging system.

    Science.gov (United States)

    Murakami, Hironaru; Tonouchi, Masayoshi

    2010-01-01

    A high-sensitive scanning laser magneto-optical (MO) imaging system has been developed. The system is mainly composed of a laser source, galvano meters, and a high-sensitive differential optical-detector. Preliminary evaluation of system performance by using a Faraday indicator with a Faraday rotation coefficient of 3.47 x 10(-5) rad/microm Oe shows a magnetic sensitivity of about 5 microT, without any need for accumulation or averaging processing. Using the developed MO system we have succeeded in the fast and quantitative imaging of a rotationally symmetric magnetic field distribution around an YBa(2)Cu(3)O(7-delta) (YBCO) strip line applied with dc-biased current, and also succeeded in the detection of quantized fine signals corresponding to magnetic flux quantum generation in a superconducting loop of an YBCO Josephson vortex flow transistor. Thus, the developed system enables us not only to do fast imaging and local signal detection but also to directly evaluate both the strength and direction of a magnetic signal.

  9. Investigation of laser radar systems based on mid-infrared semiconductor lasers

    Science.gov (United States)

    Rybaltowski, Adam

    This dissertation deals with the possibility of utilizing mid-infrared semiconductor lasers in systems of optical remote sensing with range resolution, called laser radar or lidar. The main subject investigated in this dissertation is two-fold: firstly, an analysis of the signal-to-noise ratio (SNR) and related maximum sensing range calculations in this type of lidar based on available system components, and---secondly---improvements in the Random-Modulation Continuous-Wave (RM-CW) lidar technique to better utilize available mid-infrared semiconductor lasers. As far as the SNR analysis is concerned, an appropriate framework has been constructed to analyze post-demodulation noise in mid-infrared direct-detection RM-CW lidar. It is based on a generalization of the Wiener-Khintchine theorem; noise is assumed to be additive, stationary, and have an arbitrary power spectrum. This is in contrast to the SNR analysis in the literature on this subject, which is inadequate for mid-infrared RM-CW lidar as it only considers Poissonian fluctuations of the number of detected photons. In addition to regular SNR analysis, the framework derived in this dissertation allows treatment of singularities such as demodulation with an unbalanced sequence in 1/f noise. To calculate maximum lidar sensing range, the following detection limits have been considered: signal shot noise, background blackbody radiation shot noise based on the Background-Limited Photodetection (BLIP) detectivity limit, and minimum-size detector noise given by diffraction-limited focusing. The latter is found to be of greatest practical interest. Furthermore, a lidar figure of merit has been introduced, and all quantities related to lidar performance and its detection limits have been presented graphically. Since pseudo-random sequences discussed in the literature have been found highly non-optimal for most applications of RM-CW lidar, a framework for the construction of new pseudo-random sequences of desired

  10. Laser heating of aqueous samples on a micro-optical-electro-mechanical system

    Science.gov (United States)

    Beer, Neil Reginald; Kennedy, Ian

    2013-02-05

    A system of heating a sample on a microchip includes the steps of providing a microchannel flow channel in the microchip; positioning the sample within the microchannel flow channel, providing a laser that directs a laser beam onto the sample for heating the sample; providing the microchannel flow channel with a wall section that receives the laser beam and enables the laser beam to pass through wall section of the microchannel flow channel without being appreciably heated by the laser beam; and providing a carrier fluid in the microchannel flow channel that moves the sample in the microchannel flow channel wherein the carrier fluid is not appreciably heated by the laser beam.

  11. Advances in lasers and optical micro-nano-systems

    Science.gov (United States)

    Laurell, F.; Fazio, E.

    2010-09-01

    Lasers represent a well consolidated technology: nevertheless, research in this field remains very active and productive, in both basic and applied directions. At the moment significant attention is given to those sources that bring together high power and compactness. Such high power lasers find important applications for material treatments and such applications are presented by Ehsani et al and Saiedeh Saghafi et al, in the treatment of dielectric thin films (Alteration of optical and morphological properties of polycarbonate illuminated by visible/IR laser beams) or of biological tissues like pistachio seeds (Investigating the effects of laser beams (532 and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis). In particular the latter paper show how laser sources can find very important applications in new domains, preserving goods and food without the need for preservatives or pesticides by simply sterilizing them using light. Optical Micro and Nano Systems presents a new domain for exploration. In this framework this special issue is very attractive, because it assembles papers reporting new results in three directions: new techniques for monitoring integrated micro- and nano-systems, new integrated systems and novel high performance metamaterial configurations. Integrated micro-components can be monitored and controlled using reflectance measurements as presented by Piombini et al (Toward the reflectance measurement of micro components). Speckle formation during laser beam reflection can also be a very sophisticated tool for detecting ultra-precise displacements, as presented by Filter et al (High resolution displacement detection with speckles : accuracy limits in linear displacement speckle metrology). Three dimensional integrated optical structures is indeed a big challenge and a peculiarity of photonics, they can be formed through traditional holography or using more sophisticated and novel ! technologies. Thus, special

  12. Integrated modeling of the GMT laser tomography adaptive optics system

    Science.gov (United States)

    Piatrou, Piotr

    2014-08-01

    Laser Tomography Adaptive Optics (LTAO) is one of adaptive optics systems planned for the Giant Magellan Telescope (GMT). End-to-end simulation tools that are able to cope with the complexity and computational burden of the AO systems to be installed on the extremely large telescopes such as GMT prove to be an integral part of the GMT LTAO system development endeavors. SL95, the Fortran 95 Simulation Library, is one of the software tools successfully used for the LTAO system end-to-end simulations. The goal of SL95 project is to provide a complete set of generic, richly parameterized mathematical models for key elements of the segmented telescope wavefront control systems including both active and adaptive optics as well as the models for atmospheric turbulence, extended light sources like Laser Guide Stars (LGS), light propagation engines and closed-loop controllers. The library is implemented as a hierarchical collection of classes capable of mutual interaction, which allows one to assemble complex wavefront control system configurations with multiple interacting control channels. In this paper we demonstrate the SL95 capabilities by building an integrated end-to-end model of the GMT LTAO system with 7 control channels: LGS tomography with Adaptive Secondary and on-instrument deformable mirrors, tip-tilt and vibration control, LGS stabilization, LGS focus control, truth sensor-based dynamic noncommon path aberration rejection, pupil position control, SLODAR-like embedded turbulence profiler. The rich parameterization of the SL95 classes allows to build detailed error budgets propagating through the system multiple errors and perturbations such as turbulence-, telescope-, telescope misalignment-, segment phasing error-, non-common path-induced aberrations, sensor noises, deformable mirror-to-sensor mis-registration, vibration, temporal errors, etc. We will present a short description of the SL95 architecture, as well as the sample GMT LTAO system simulation

  13. Altimetric surveying with airborne laser system; Medicao altimetrica utilizando sistema a laser aerotransportado

    Energy Technology Data Exchange (ETDEWEB)

    Sallem Filho, Silas; Paoletto, Silvia M.; Bonatto, Amarildo [Esteio Engenharia, Curitiba, PR (Brazil)

    2003-07-01

    Airborne Laser Scanning (ALS) makes faster and more accurate the obtaining of Digital Elevation Model and Digital Terrain Model compared to conventional photogrammetry. The system generates Laser pulses towards the terrain, perpendicular to the flight line, scanning the terrain surface and recording the distances from the sensor to the soil for each pulse . The main characteristics of the system is the measurement of the first and the last return for each pulse, allowing the objects identification that are above the ground like vegetation. With this function it is possible the determination of volumes and biomass estimate, besides the virtual removal of vegetation covering. The Digital Terrain Models are used for Digital Orthophotos rectification and to obtain contour lines for topography maps. The correct points classification according the elevation, allows the identification of man-made features road and river crossings and human use in the the pipeline corridor. Some additional products, as hypsometric images and intensity images helps in the identification of features on pipeline projects as well as the obtaining of the obstacles height. (author)

  14. Interaction of plasmas in laser ion source with double laser system

    Energy Technology Data Exchange (ETDEWEB)

    Fuwa, Y., E-mail: yasuhiro.fuwa@riken.jp [Graduate School of Science, Kyoto University, Kyoto (Japan); Riken, Wako, Saitama (Japan); Ikeda, S. [Riken, Wako, Saitama (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Tokyo (Japan); Kumaki, M. [Riken, Wako, Saitama (Japan); Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo (Japan); Sekine, M. [Riken, Wako, Saitama (Japan); Department of Nuclear Engineering, Tokyo Institute of Technology, Meguro, Tokyo (Japan); Cinquegrani, D. [Nuclear Engineering and Radiological Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Romanelli, M. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850 (United States); Kanesue, T.; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Iwashita, Y. [Institute for Chemical Research, Kyoto University, Uji, Kyoto (Japan)

    2014-02-15

    Multiple laser shots could be used to elongate an ion beam pulse width or to intensify beam current from laser ion sources. In order to confirm the feasibility of the multiple shot scheme, we investigated the properties of plasmas produced by double laser shots. We found that when the interval of the laser shots is shorter than 10 μs, the ion current profile had a prominent peak, which is not observed in single laser experiments. The height of this peak was up to five times larger than that of single laser experiment.

  15. Research and development of the laser tracker measurement system

    Science.gov (United States)

    Zhang, Z. L.; Zhou, W. H.; Lao, D. B.; Yuan, J.; Dong, D. F. F.; Ji, R. Y. Y.

    2013-01-01

    The working principle and system design of the laser tracker measurement system are introduced, as well as the key technologies and solutions in the implementation of the system. The design and implementation of the hardware and configuration of the software are mainly researched. The components of the hardware include distance measuring unit, angle measuring unit, tracking and servo control unit and electronic control unit. The distance measuring devices include the relative distance measuring device (IFM) and the absolute distance measuring device (ADM). The main component of the angle measuring device, the precision rotating stage, is mainly comprised of the precision axis and the encoders which are both set in the tracking head. The data processing unit, tracking and control unit and power supply unit are all set in the control box. The software module is comprised of the communication module, calibration and error compensation module, data analysis module, database management module, 3D display module and the man-machine interface module. The prototype of the laser tracker system has been accomplished and experiments have been carried out to verify the proposed strategies of the hardware and software modules. The experiments showed that the IFM distance measuring error is within 0.15mm, the ADM distance measuring error is within 3.5mm and the angle measuring error is within 3〞which demonstrates that the preliminary prototype can realize fundamental measurement tasks.

  16. Systems and assemblies for transferring high power laser energy through a rotating junction

    Energy Technology Data Exchange (ETDEWEB)

    Norton, Ryan J.; McKay, Ryan P.; Fraze, Jason D.; Rinzler, Charles C.; Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

    2016-01-26

    There are provided high power laser devices and systems for transmitting a high power laser beam across a rotating assembly, including optical slip rings and optical rotational coupling assemblies. These devices can transmit the laser beam through the rotation zone in free space or within a fiber.

  17. Innovative surface decontamination using a manipulator-deployed laser system

    Energy Technology Data Exchange (ETDEWEB)

    Bremmer, J.; Gentes, S. [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Technology and Management in Construction Technology and Management for the Decommissioning of Nuclear Facilities; Littwin, R.; Hurtado, A.; Lippmann, W. [Dresden Univ. of Technology (TUD) (Germany). Chair of Hydrogen Technology and Nuclear Power Engineering

    2010-05-15

    The successful decommissioning and dismantlement of nuclear facilities requires a great number and variety of processes and actions. These include, inter alia, the qualified decontamination of surfaces. The associated tasks are manifold, ranging from simple cleaning to complete surface ablation. The latter is particularly challenging due to the multitude of surfaces in nuclear facilities which, to complicate things further, are made of the most diverse materials. Consequently, besides pure surfaces of concrete, plaster or masonry, it is also necessary to ablate coatings such as protective paints. These can be found both on mineral and metallic constructional components. A crucial factor in surface decontamination work is the effectiveness and economic efficiency of the methods used. The same applies to the avoidance of cross contamination and secondary waste. Only few of the currently available processes fully meet all these criteria and are suited for this kind of task. Due to the increasing number of decommissioning projects in Germany and the small number of processes available to accomplish them, there is a rising demand for suitable and efficient decommissioning systems. An innovative system for manipulator-controlled laser ablation of surfaces that fully meets these criteria is currently being developed under the research project MANOLA (manipulatorgesteuerter Abtrag von Oberflaechen durch Lasertechnologie = manipulator-controlled laser ablation of surfaces), a joint project of the Chair of Hydrogen Technology and Power Engineering of the Dresden University of Technology and the Chair of Technology and Management of the Decommissioning of Nuclear Facilities at the Karlsruhe Institute of Technology (KIT), funded by the German Federal Ministry of Education and Research (BMBF). The objective of this research project is to ablate contaminated surfaces by means of a manipulator-deployed laser head. It was shown by numerous experiments in the preceding research

  18. System design of welding dynamic displacement measurement using laser ESPI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the advantages of electronic speckle pattern interferometry(ESPI), such as non-contact, high precision, strong parasitic light resistance, and full-field measurement, a system for measuring welding dynamic displacement fields using ESPI was designed. The system consists of a 70mW He-Ne laser source, an optical path system, a computer-assisted frame grabber and a processing system. By measuring dynamic displacement fields on one LY2 aluminum alloy plate during an argon arc point welding, it can be proved that using ESPI to measure welding dynamic displacement fields is fully feasible, and this method can offer a solid experimental base for the structure mechanics.

  19. System Design Considerations In Bar-Code Laser Scanning

    Science.gov (United States)

    Barkan, Eric; Swartz, Jerome

    1984-08-01

    The unified transfer function approach to the design of laser barcode scanner signal acquisition hardware is considered. The treatment of seemingly disparate system areas such as the optical train, the scanning spot, the electrical filter circuits, the effects of noise, and printing errors is presented using linear systems theory. Such important issues as determination of depth of modulation, filter specification, tolerancing of optical components, and optimi-zation of system performance in the presence of noise are discussed. The concept of effective spot size to allow for impact of optical system and analog processing circuitry upon depth of modulation is introduced. Considerations are limited primarily to Gaussian spot profiles, but also apply to more general cases. Attention is paid to realistic bar-code symbol models and to implications with respect to printing tolerances.

  20. Chaos synchronization characteristics in erbium-doped fiber laser systems

    Science.gov (United States)

    Imai, Y.; Murakawa, H.; Imoto, T.

    2003-03-01

    Chaos synchronization characteristics in the master-slave and slave-slave systems with modulated erbium-doped fiber lasers are investigated numerically. We find that synchronization state of chaos becomes better, i.e., the correlation coefficient between the two outputs reaches unity, as the difference in the input power between the two subsystems decreases and is not dependent strongly upon the difference in the modulation index in both the master-slave and slave-slave systems. In the master-slave system, the highest correlation coefficient is attained at the smaller pump power and the larger modulation index in the slave subsystem than those in the master subsystem. On the other hand, the correlation coefficient equal to unity is achieved with the identical parameters in the slave 1 and 2 subsystems in the slave-slave system.

  1. Calibration of an Automatic System Using a Laser Signature

    Directory of Open Access Journals (Sweden)

    Edward F. Plinski

    2003-04-01

    Full Text Available The specific phenomenon, which appears in tuned CO2 lasers, called a laser signature, is used as a standard for calibration of the servomechanism. The proposed servomechanism can be used for continuous investigations of the laser signatures of different laser media.

  2. A laser-wire system for the International Linear Collider

    Indian Academy of Sciences (India)

    Nicolas Delerue; Sudhir Dixit; Fred Gannaway; David Howell; Myriam Qurshi; Grahame Blair; Stewart Boogert; Gary Boorman; Chafik Driouichi; Lawerence Deacon; Alexander Aryshev; Pavel Karataev; Nobuhiro Terunnuma; Junji urakawa; Axel Brachmann; Joe Frisch; Marc Ross

    2007-12-01

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  3. A Laser-Wire System for the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Delerue, N.; Dixit, S.; Gannaway, F.; Howell, D.; Qurshi, M.; Blair, G.; Boogert, S.; Boorman, G.; Driouichi, C.; Deacon, L.; Aryshev, A.; Karataev, P.; Terunuma, N.; Urakawa, J.; Brachmann, A.; Frisch, J.; Ross, M.; /Oxford U. /Royal Holloway, U. of London /KEK, Tsukuba /SLAC

    2009-04-30

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  4. Spectral and Temporal Characteristics of LS PEG and TW PIC Using XMM-NEWTON Data

    Science.gov (United States)

    Talebpour Sheshvan, Nasrin; Balman, Solen

    2016-07-01

    We report the analysis of archival XMM-Newton X-ray observations of LS Peg and TW Pic. These are Cataclysmic Variables (CVs) suggested as Intermediate Polars (IPs), but unconfirmed in the X-rays. Identification of several periodic oscillations in the optical band hint them as IPs. Unlike the previous spectral analysis on the EPIC-MOS data by fitting a hot optically thin plasma emission model with a single temperature for LS Peg, we simultaneously fitted all EPIC spectrum (pn+MOS) using a composite model of absorption for interstellar medium (tbabs) with two different partial covering absorbers (pcfabs) including a multitemperature plasma emission component (cevmkl) and a Gaussian emission line at 6.4 keV. TW Pic is best modeled in a similar manner with only one partial covering absorber and an extra Gaussian emission line at 6.7 keV. LS Peg has a maximum plasma temperature of ˜14.8 keV with an X-ray luminosity of ˜5×10^{32}ergs ^{-1} translating to an accretion rate of ˜1.27×10^{-10}M _{⊙}yr ^{-1}. TW Pic shows kT _{max} ˜38.7 keV with an X-ray luminosity around 1.6×10^{33}ergs ^{-1} at an accretion rate of ˜4×10^{-10}M _{⊙}yr ^{-1}. In addition, we discuss orbital modulations in the X-rays and power spectral analysis, and derive the EPIC pn spectra for orbital minimum and orbital maximum phases for both sources. We elaborate on the geometry of accretion and absorption in the X-ray emitting regions of both sources with articulation on the magnetic nature.

  5. Thermal Performance of ATLAS Laser Thermal Control System Demonstration Unit

    Science.gov (United States)

    Ku, Jentung; Robinson, Franklin; Patel, Deepak; Ottenstein, Laura

    2013-01-01

    The second Ice, Cloud, and Land Elevation Satellite mission currently planned by National Aeronautics and Space Administration will measure global ice topography and canopy height using the Advanced Topographic Laser Altimeter System {ATLAS). The ATLAS comprises two lasers; but only one will be used at a time. Each laser will generate between 125 watts and 250 watts of heat, and each laser has its own optimal operating temperature that must be maintained within plus or minus 1 degree Centigrade accuracy by the Laser Thermal Control System (LTCS) consisting of a constant conductance heat pipe (CCHP), a loop heat pipe (LHP) and a radiator. The heat generated by the laser is acquired by the CCHP and transferred to the LHP, which delivers the heat to the radiator for ultimate rejection. The radiator can be exposed to temperatures between minus 71 degrees Centigrade and minus 93 degrees Centigrade. The two lasers can have different operating temperatures varying between plus 15 degrees Centigrade and plus 30 degrees Centigrade, and their operating temperatures are not known while the LTCS is being designed and built. Major challenges of the LTCS include: 1) A single thermal control system must maintain the ATLAS at 15 degrees Centigrade with 250 watts heat load and minus 71 degrees Centigrade radiator sink temperature, and maintain the ATLAS at plus 30 degrees Centigrade with 125 watts heat load and minus 93 degrees Centigrade radiator sink temperature. Furthermore, the LTCS must be qualification tested to maintain the ATLAS between plus 10 degrees Centigrade and plus 35 degrees Centigrade. 2) The LTCS must be shut down to ensure that the ATLAS can be maintained above its lowest desirable temperature of minus 2 degrees Centigrade during the survival mode. No software control algorithm for LTCS can be activated during survival and only thermostats can be used. 3) The radiator must be kept above minus 65 degrees Centigrade to prevent ammonia from freezing using no more

  6. In-system Performance of MQW Lasers Exposed to High Magnetic Field

    CERN Document Server

    Jensen, Fredrik Bjorn Henning; Azevedo, C S; Cervelli, Giovanni; Gill, Karl; Grabit, Robert; Vasey, François

    2000-01-01

    The effect of magnetic field has been investigated on 1310nm edge-emitting multi-quantum-well lasers. These lasers are candidate transmitters for the CMS tracker optical link, which will be operated in a 4T solenoidal magnetic field. In-situ measurements up to 2.4T of in-system laser analogue performance and laser spectral characteristics were carried out. No degradation of performance and spectral characteristics was observed

  7. Laser systems configured to output a spectrally-consolidated laser beam and related methods

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-01-10

    A laser apparatus includes a plurality of pumps each of which is configured to emit a corresponding pump laser beam having a unique peak wavelength. The laser apparatus includes a spectral beam combiner configured to combine the corresponding pump laser beams into a substantially spatially-coherent pump laser beam having a pump spectrum that includes the unique peak wavelengths, and first and second selectively reflective elements spaced from each other to define a lasing cavity including a lasing medium therein. The lasing medium generates a plurality of gain spectra responsive to absorbing the pump laser beam. Each gain spectrum corresponds to a respective one of the unique peak wavelengths of the substantially spatially-coherent pump laser beam and partially overlaps with all other ones of the gain spectra. The reflective elements are configured to promote emission of a laser beam from the lasing medium with a peak wavelength common to each gain spectrum.

  8. Annular beam shaping system for advanced 3D laser brazing

    Science.gov (United States)

    Pütsch, Oliver; Stollenwerk, Jochen; Kogel-Hollacher, Markus; Traub, Martin

    2012-10-01

    As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.

  9. A compact and robust diode laser system for atom interferometry on a sounding rocket

    CERN Document Server

    Schkolnik, V; Wenzlawski, A; Grosse, J; Kohfeldt, A; Döringshoff, K; Wicht, A; Windpassinger, P; Sengstock, K; Braxmaier, C; Krutzik, M; Peters, A

    2016-01-01

    We present a diode laser system optimized for laser cooling and atom interferometry with ultra-cold rubidium atoms aboard sounding rockets as an important milestone towards space-borne quantum sensors. Design, assembly and qualification of the system, combing micro-integrated distributed feedback (DFB) diode laser modules and free space optical bench technology is presented in the context of the MAIUS (Matter-wave Interferometry in Microgravity) mission. This laser system, with a volume of 21 liters and total mass of 27 kg, passed all qualification tests for operation on sounding rockets and is currently used in the integrated MAIUS flight system producing Bose-Einstein condensates and performing atom interferometry based on Bragg diffraction. The MAIUS payload is being prepared for launch in fall 2016. We further report on a reference laser system, comprising a rubidium stabilized DFB laser, which was operated successfully on the TEXUS 51 mission in April 2015. The system demonstrated a high level of technol...

  10. Laser measurement and analysis of reposition error in polishing systems

    Science.gov (United States)

    Liu, Weisen; Wang, Junhua; Xu, Min; He, Xiaoying

    2015-10-01

    In this paper, robotic reposition error measurement method based on laser interference remote positioning is presented, the geometric error is analyzed in the polishing system based on robot and the mathematical model of the tilt error is presented. Studies show that less than 1 mm error is mainly caused by the tilt error with small incident angle. Marking spot position with interference fringe enhances greatly the error measurement precision, the measurement precision of tilt error can reach 5 um. Measurement results show that reposition error of the polishing system is mainly from the tilt error caused by the motor A, repositioning precision is greatly increased after polishing system improvement. The measurement method has important applications in the actual error measurement with low cost, simple operation.

  11. A Novel Portable Multi-Wavelength Laser System

    Science.gov (United States)

    Charlton, Andy; Dickinson, B.

    There is an established need for a portable and affordable Q-switched laser system for use in studio conservation and small scale field use. The ideal system would be capable of producing a variety of wavelengths ranging from the ultraviolet to the infrared with sufficient energy per pulse to treat a wide range of materials including stone, marble, terracotta, wood, organic materials, bone, parchment, textiles, and metals. In this paper we report on such a system which is capable of delivering Q-switched output at 1,064nm in excess of 300mJ per pulse and at repetition rates of up to 25 Hz. Additional outputs are also reported at 266 nm, 355 nm, 532 nm, and 2.94 μm. Preliminary cleaning results on a small range of objects using the Q-switched 1,064nm output are presented.

  12. Laser Projection Photogrammetry and Video System for Quantification and Mensuration

    Science.gov (United States)

    Borne, L. J.; Kocak, D. M.

    2005-05-01

    This paper describes a novel photogrammetric laser/video system suited for a variety of underwater quantification and mensuration applications. The system is comprised of a purpose-built frame to which are mounted a roll/pitch motion reference sensor, video camera, and three microlasers. Orientation of the three lasers provides for optical triangulation, which allows computation of range at a specific location in the field-of-view. From this information and that derived from the motion sensor, the spatially variant magnification can be determined over the entire field-of-view using a simple algorithm. A variety of parameters can then be estimated using image-processing techniques, including perspective overlays, range to a point or location, scale in any region of the image, and area measurements. Specialized image processing algorithms can be added to provide object recognition, tracking, and other information. The specification of each component (i.e., laser wavelength and power, camera sensitivity and resolution, and dynamic range) and mounting geometry are determined based on the specific application and needed accuracy. The system can be mounted for use on any subsea vehicle or platform and provides a low cost automated approach for obtaining quantitative information from standard undersea video. Currently, the application software allows for post-processing of the video information but could be modified to process the video information in real-time. The first application of this system will be used by Washington State Department of Fish and Wildlife researchers onboard DSV DELTA. The system may prove valuable for estimating the abundance of commercially and recreationally exploited groundfish species within a transect area conducted off the coast of Washington State. This non-intrusive, direct observation technique affords a means to estimate the density of certain benthic fish species in high relief areas that currently cannot be sampled using routine trawl

  13. Autogeneous Laser and Hybrid Laser Arc Welding of T-joint Low Alloy Steel with Fiber Laser Systems

    Science.gov (United States)

    Unt, A.; Lappalainen, E.; Salminen, A.

    This paper is focused on the welding of low alloy steels S355 and AH36 in thicknesses 6, 8 and 10 mm in T-joint configuration using either autogeneous laser welding or laser-arc hybrid welding (HLAW) with high power fiber lasers. The aim was to obtain understanding of the factors influencing the size of the fillet and weld geometry through methodologically studying effects of laser power, welding speed, beam alignment relative to surface, air gap, focal point position and order of processes (in case of HLAW) and to get a B quality class welds in all thicknesses after parameter optimization.

  14. The evolution of a large laser control system - From Shiva to Nova

    Energy Technology Data Exchange (ETDEWEB)

    Suski, G.J.; Holloway, F.W.

    1979-09-01

    The Nova laser system is a 200 terawatt laser facility under construction at Lawrence Livermore Laboratory. Its current operational predecessor, the 30 terawatt Shiva laser, is controlled and diagnosed via a network of 50 computers. Although the highly distributed Shiva control system has proven effective and reliable, the need for more integrated process control on Nova is leading to a more centralized architecture. An overview of these control systems is presented and their differences are discussed.

  15. Discovery of seven T Tauri stars and a brown dwarf candidate in the nearby TW Hydrae Association

    CERN Document Server

    Webb, R A; Platais, I; Patience, J; White, R J; Schwartz, M J; McCarthy, C

    1999-01-01

    We report the discovery of five T Tauri star systems, two of which are resolved binaries, in the vicinity of the nearest known region of recent star formation, the TW Hydrae Association. The newly discovered systems display the same signatures of youth (namely high X-ray flux, large Li abundance and strong chromospheric activity) and the same proper motion as the original five members. These similarities firmly establish the group as a bona fide T Tauri association, unique in its proximity to Earth and its complete isolation from any known molecular clouds. At an age of ~10 Myr and a distance of ~50 pc, the association members are excellent candidates for future studies of circumstellar disk dissipation and the formation of brown dwarfs and planets. Indeed, as an example, our speckle imaging revealed a faint, very likely companion 2" north of CoD-33 7795 (TWA 5). Its color and brightness suggest a spectral type ~M8.5 which, at an age of ~10^7 years, implies a mass ~20 M(Jupiter).

  16. Development of multiple laser frequency control system for Ca{sup +} isotope ion cooling

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyunghun, E-mail: jung@lyman.q.t.u-tokyo.ac.jp [The University of Tokyo, Nuclear Professional School (Japan); Yamamoto, Yuta, E-mail: yamamoto@lyman.q.t.u-tokyo.ac.jp [The University of Tokyo, Department of Nuclear Engineering and Management (Japan); Hasegawa, Shuichi, E-mail: hasegawa@tokai.t.u-tokyo.ac.jp [The University of Tokyo, Nuclear Professional School (Japan)

    2015-11-15

    We here developed and evaluated a laser frequency control system which synchronizes the laser frequency to the resonance of target Ca {sup +} isotope ion whose having more than 8 GHz of isotope shift based on the Fringe Offset Lock method for simple operation of ICPMS-ILECS (Inductively Coupled Plasma Mass Spectrometry - Ion trap Laser Cooling Spectroscopy) The system fulfilled the minimum requirements of four slave lasers stability for Doppler cooling of Ca {sup +} ions. A performance of the system was evaluated by cooling {sup 40}Ca {sup +} ions with the stabilized slave lasers. All the stable even Ca {sup +} isotope ions were trapped and their fluorescence was observed by switching laser frequencies using the system. An odd calcium isotope {sup 43}Ca {sup +}cooling was also succeeded by the control system.

  17. A Chandra Observation of the TW Hydrae Association Brown Dwarf 2MASSW J1139511-315921

    CERN Document Server

    Castro, Philip J; Gagné, Marc

    2011-01-01

    We report on a sequence of Chandra X-ray Observatory observations of the TW Hydrae brown dwarf (BD) 2MASSW J1139511-315921 (2M1139). In the combined 31 ks ACIS-S exposure, 2M1139 is detected at the 3-sigma confidence level. We find an X-ray luminosity of L_X = 1.4^(+2.7)_(-1.0) x 10^26 ergs s^-1 or log(L_X/L_bol) = -4.8 +/- 0.3. This object is similar to another TW Hydrae BD member, CD-33 7795B (TWA 5B): both have H-alpha emission, both show no signatures of accretion, and both have comparable ages and spectral types. TWA 5B was previously detected in X-rays with a luminosity of L_X = 4 x 10^27 ergs s^-1 or log(L_X/L_bol) = -3.4, an order of magnitude more luminous in X-rays than 2M1139. We find that the discrepancy between the X-ray luminosity of 2M1139 and TWA 5B is consistent with the spread in X-ray luminosity in the Orion Nebula Cluster (ONC) for BDs of similar spectral types. Though rotation may play a role in the X-ray activity of ultracool dwarfs like 2M1139 and TWA 5B, the discrepancy cannot be expla...

  18. Laser speckle reduction by phase range limited computer generated hologram in laser projection display system.

    Science.gov (United States)

    Chang, Yan-Shuo; Lin, Chia-Hsin; Hsu, Ku-Hui; Hsu, Wei-Feng; Hsiao, Li-Jen; Lin, Hoang Yan

    2014-09-20

    The speckle phenomenon is an annoyance in laser projection display systems. We propose a novel speckle suppression method that utilizes the interference concept on a pixel point, which reduces the speckle contrast (SC) of the project image by limiting the phase distribution range in the optical field. The SC formula is derived in the uniform interval phase range for partially developed speckle conditions, showing that the SC can be lowered by lessening the phase range limitation. In the ideal simulation model, the SC can be reduced from 98.77% to 0% as the phase range limitation varies from 2π to 0. The phase range limitation model is a novel method using a computer generated hologram to provide beam shaping and phase limitation. In a more realistic simulation model, the SC is reduced from 99.18% to 16.68%.

  19. The laser interferometer system for the large optics diamond turning machine

    Energy Technology Data Exchange (ETDEWEB)

    Baird, E D; Donaldson, R R; Patterson, S R

    1999-06-29

    The purpose of this report is to describe the Laser Interferometer System designed for the Large Optics Diamond Turning Machine (LODTM). To better understand the laser interferometer system, it is useful to begin with an overview of the LODTM metrology system.

  20. High Performance Image Processing And Laser Beam Recording System

    Science.gov (United States)

    Fanelli, Anthony R.

    1980-09-01

    The article is meant to provide the digital image recording community with an overview of digital image processing, and recording. The Digital Interactive Image Processing System (DIIPS) was assembled by ESL for Air Force Systems Command under ROME AIR DEVELOPMENT CENTER's guidance. The system provides the capability of mensuration and exploitation of digital imagery with both mono and stereo digital images as inputs. This development provided for system design, basic hardware, software and operational procedures to enable the Air Force's System Command photo analyst to perform digital mensuration and exploitation of stereo digital images as inputs. The engineering model was based on state-of-the-art technology and to the extent possible off-the-shelf hardware and software. A LASER RECORDER was also developed for the DIIPS Systems and is known as the Ultra High Resolution Image Recorder (UHRIR). The UHRIR is a prototype model that will enable the Air Force Systems Command to record computer enhanced digital image data on photographic film at high resolution with geometric and radiometric distortion minimized.

  1. Physics of laser fusion. Volume IV. The future development of high-power solid-state laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Emmett, J.L.; Krupke, W.F.; Trenholme, J.B.

    1982-11-01

    Solid state lasers, particularly neodymium glass systems, have undergone intensive development during the last decade. In this paper, we review solid state laser technology in the context of high-peak-power systems for inertial confinement fusion. Specifically addressed are five major factors: efficiency, wavelength flexibility, average power, system complexity, and cost; these factors today limit broader application of the technology. We conclude that each of these factors can be greatly improved within current fundamental physical limits. We further conclude that the systematic development of new solid state laser madia, both vitreous and crystalline, should ultimately permit the development of wavelength-flexible, very high average power systems with overall efficiencies in the range of 10 to 20%.

  2. Controlling laser beam irradiation area using an optical duplicate system to improve satellite-ground laser communications

    Science.gov (United States)

    Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko

    2016-08-01

    To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.

  3. 'Abnormal' angle response curves of TW/Rs for near zero tilt and high tilt channeling implants

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baonian; Gossmann, Hans-Joachim; Toh, Terry; Colombeau, Benjamin; Todorov, Stan; Sinclair, Frank; Shim, Kyu-Ha; Henry, Todd [Applied Materials - Varian Semiconductor Equipment, 35 Dory Road, Gloucester, MA 01930 (United States)

    2012-11-06

    Angle control has been widely accepted as the key requirement for ion implantation in semiconductor device processing. From an ion implanter point of view, the incident ion direction should be measured and corrected by suitable techniques, such as XP-VPS for the VIISta implanter platform, to ensure precision ion placement in device structures. So called V-curves have been adopted to generate the wafer-based calibration using channeling effects as the Si lattice steer ions into a channeling direction. Thermal Wave (TW) or sheet resistance (Rs) can be used to determine the minimum of the angle response curve. Normally it is expected that the TW and Rs have their respective minima at identical angles. However, the TW and Rs response to the angle variations does depend on factors such as implant species, dose, and wafer temperature. Implant damage accumulation effects have to be considered for data interpretation especially for some 'abnormal' V-curve data. In this paper we will discuss some observed 'abnormal' angle responses, such as a) TW/Rs reverse trend for Arsenic beam, 2) 'W' shape of Rs Boron, and 3) apparent TW/Rs minimum difference for high tilt characterization, along with experimental data and TCAD simulations.

  4. COHERENT LIDAR SYSTEM BASED ON A SEMICONDUCTOR LASER AND AMPLIFIER

    DEFF Research Database (Denmark)

    2009-01-01

    invention provides a coherent LIDAR system comprising a semiconductor laser for emission of a measurement beam of electromagnetic radiation directed towards a measurement volume for illumination of particles in the measurement volume, a reference beam generator for generation of a reference beam, a detector......The present invention relates to a compact, reliable and low-cost coherent LIDAR (Light Detection And Ranging) system for remote wind-speed determination, determination of particle concentration, and/or temperature based on an all semiconductor light source and related methods. The present...... for generation of a detector signal by mixing of the reference beam with light emitted from the particles in the measurement volume illuminated by the measurement beam, and a signal processor for generating a velocity signal corresponding to the velocity of the particles based on the detector signal....

  5. Characterization of Wavelength Tunable Lasers for Future Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Prince M. Anandarajah

    2010-02-01

    Full Text Available The use of tunable lasers (TL in dense wavelength division multiplexed (DWDM networks for optical switching, routing and networking has gained a lot of interest in recent years. Employment of such TLs as tunable transmitters in wavelength packet switched (WPS networks is one of the possible applications of these devices. In such systems, the information to be transmitted could be encoded onto a destination dependent wavelength and the routing of traffic could be performed on a packet-by-packet basis. The authors investigate the possibility of using TLs in DWDM WPS networks by focusing on the characterisation of the instantaneous frequency drift of a TL due to wavelength tuning and direct modulation. Characterization of the linewidth of the TLs is also presented to verify the feasibility of using TLs in systems employing advanced modulation formats.

  6. Flexible Calibration Method for 3D Laser Scanner System

    Institute of Scientific and Technical Information of China (English)

    杨中东; 王鹏; 李晓慧; 孙长库

    2014-01-01

    In this paper, a flexible high-precision calibration method suitable for industrial field was proposed. The complexity of the coordinate transformation was simplified by choosing the camera coordinate system as the unified reference coordinate system. A flexible planar calibration pattern was introduced to the calibration process, which can be arbitrarily placed and from which the known feature points can be extracted to construct other unknown feature points. With the known intrinsic parameters, the laser projector plane equation was fitted by the multi-noncollinear points, which were acquired through the principle of triangulation and the projective invariance of cross ratio. With this method, the strict alignment and multiple times of coordinate transformation can be avoided. Experimental results showed that the arithmetic mean of the root mean square (RMS) error of distance was 0.000 7 mm.

  7. XUV free-electron laser-based projection lithography systems

    Energy Technology Data Exchange (ETDEWEB)

    Newnam, B.E.

    1990-01-01

    Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.

  8. A prototype erodible mask delivery system for the excimer laser.

    Science.gov (United States)

    Maloney, R K; Friedman, M; Harmon, T; Hayward, M; Hagen, K; Gailitis, R P; Waring, G O

    1993-04-01

    The authors developed an erodible mask delivery system for the argon-fluoride 193-nm excimer laser, which offers the possibility of correcting hyperopia and astigmatism as well as myopia. Masks were made of polymethylmethacrylate on a quartz window, with intended corrections for myopia and hyperopia of 2.5 and 5 diopters (D). Ablations using the mask and control ablations using an expanding diaphragm were performed in 30 eyes of 15 pigmented rabbits with an Excimed UV200 laser (Summit Technology, Inc, Waltham, MA). The rabbits were followed for 134 days with regular biomicroscopy and retinoscopic examination by two observers. Ablations with the mask to correct myopia were successful and produced stable corrections, although the higher-power mask produced undercorrections. Hyperopic masks produced paradoxic myopic corrections, possibly due to the lack of a transition zone at the edge of the mask. Corneas ablated with the mask had less sub-epithelial haze than those ablated with the diaphragm at all examinations. Results of histopathologic examination showed epithelial hyperplasia over the ablation zone in all eyes. Dichlorotriazinyl aminofluorescein collagen staining showed subepithelial new collagen in all eyes, but there was no relation between the depth of ablation at any point on the cornea and the amount of new collagen deposited there. Myopic ablations are feasible with the erodible mask, although additional calibration is needed. Hyperopic ablations were unsuccessful with the current design. Corneas ablated with the mask may be clearer than corneas ablated with the diaphragm, possibly due to a smoother ablated surface. Regression of effect after laser ablation in the rabbit model is likely due more to epithelial hyperplasia than to stromal remodeling.

  9. Research on laser simulator for an optoelectronic confrontation HWIL test system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Pei-lu; WANG Jian-jun

    2010-01-01

    @@ A laser simulator is proposed which is based on a hardware-in-loop (HWIL) simulation test system. As an important device in the simulation test system, it is used to simulate the laser energy and the divergence angle. The laser simulator simulates the attenuation process of laser energy by the continuous rotation of Glan prisms and the changing of laser spot size through the continuous motion of the laser beam expanding telescope on the straight platform. The dynamic attenuation velocity of the laser simulator is up to 4 dB/s, and the divergence angle adjustment velocity is up to 3 mrad/s. The method is feasible for the simulation test.

  10. [Lasers].

    Science.gov (United States)

    Passeron, T

    2012-11-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Lasers.

    Science.gov (United States)

    Passeron, T

    2012-12-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  12. Laser Tracker Calibration - Testing the Angle Measurement System -

    Energy Technology Data Exchange (ETDEWEB)

    Gassner, Georg; Ruland, Robert; /SLAC

    2008-12-05

    Physics experiments at the SLAC National Accelerator Laboratory (SLAC) usually require high accuracy positioning, e. g. 100 {micro}m over a distance of 150 m or 25 {micro}m in a 10 x 10 x 3 meter volume. Laser tracker measurement systems have become one of the most important tools for achieving these accuracies when mapping components. The accuracy of these measurements is related to the manufacturing tolerances of various individual components, the resolutions of measurement systems, the overall precision of the assembly, and how well imperfections can be modeled. As with theodolites and total stations, one can remove the effects of most assembly and calibration errors by measuring targets in both direct and reverse positions and computing the mean to obtain the result. However, this approach does not compensate for errors originating from the encoder system. In order to improve and gain a better understanding of laser tracker angle measurement tolerances we extended our laboratory's capabilities with the addition of a horizontal angle calibration test stand. This setup is based on the use of a high precision rotary table providing an angular accuracy of better than 0.2 arcsec. Presently, our setup permits only tests of the horizontal angle measurement system. A test stand for vertical angle calibration is under construction. Distance measurements (LECOCQ & FUSS, 2000) are compared to an interferometer bench for distances of up to 32 m. Together both tests provide a better understanding of the instrument and how it should be operated. The observations also provide a reasonable estimate of covariance information of the measurements according to their actual performance for network adjustments.

  13. Output power stability of a HCN laser using a stepping motor for the EAST interferometer system

    Science.gov (United States)

    Zhang, J. B.; Wei, X. C.; Liu, H. Q.; Shen, J. J.; Zeng, L.; Jie, Y. X.

    2015-11-01

    The HCN laser on EAST is a continuous wave glow discharge laser with 3.4 m cavity length and 120 mW power output at 337 μ m wavelength. Without a temperature-controlled system, the cavity length of the laser is very sensitive to the environmental temperature. An external power feedback control system is applied on the HCN laser to stabilize the laser output power. The feedback system is composed of a stepping motor, a PLC, a supervisory computer, and the corresponding control program. One step distance of the stepping motor is 1 μ m and the time response is 0.5 s. Based on the power feedback control system, a stable discharge for the HCN laser is obtained more than eight hours, which satisfies the EAST experiment.

  14. Five Wavelength DFB Fibre Laser Source for WDM Systems

    DEFF Research Database (Denmark)

    Hübner, Jörg; Varming, Poul; Kristensen, Martin

    1997-01-01

    Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of <15 kHz and a sidemode suppression better than 61 dB are presented. The stability of the lasers is verified by a 10 Gbit/s transmission experiment. Five DFB fibre lasers are cascaded and pumped by a single semicondu......Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of pumped by a single...

  15. Five Wavelength DFB Fibre Laser Source for WDM Systems

    DEFF Research Database (Denmark)

    Hübner, Jörg; Varming, Poul; Kristensen, Martin

    1997-01-01

    Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of <15 kHz and a sidemode suppression better than 61 dB are presented. The stability of the lasers is verified by a 10 Gbit/s transmission experiment. Five DFB fibre lasers are cascaded and pumped by a single semicondu......Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of pumped by a single...

  16. Multi-platform laser communication networking optical antenna system design

    Science.gov (United States)

    Zhang, Tao

    2016-10-01

    In this paper, a new conclusion based on rotating parabolic model and a different scheme of laser communication networking antenna system has been put forward in the paper. Based on rotating parabolic antenna, a new theory of the optical properties have been deduced, which can realize larger dynamic, duplex, networking communications among multiple platforms in 360° azimuth and pitch range. Meanwhile, depending on the operation mode of the system, multiple mathematical optimization models have been established. Tracking communication range, emission energy efficiency and receiving energy efficiency have been analyzed and optimized. Relationship among opening up and low apertures, the lens unit aperture, focal length of lens unit as well as rotating parabolic focal length have been analyzed. Tracking pitching range and emission energy utilization has carried on the theoretical derivation and optimization and networking platform link between energy receiver and transmitter has been analyzed. Taking some parameters of this new system into calculation, optimized results can be utilized with MATLAB software for its application and system of communication engineering. The rotating parabolic internal can form a hollow structure, which is utilized for miniaturization, light-weighted design and realize duplex communication in a wide range and distance. Circular orbit guidance is the modern way used in dynamic tracking system. The new theory and optical antenna system has widespread applications value as well.

  17. Temporal and Spectral Resolved Measurement of Soft X-ray From Ultrashort Pulse Laser Produced Plasma

    Institute of Scientific and Technical Information of China (English)

    W.Theobald; L.Veisz; H.Schwoerer; R.Sauerbrey; X.Z.Tang

    2001-01-01

    Ultrashort laser pulse produced plasmas are powerful sources of incoherent XUV/soft X-ray radiation and have important applications range from microscopy to lithography. Adding a prepulse is one possible way to enhance soft X-ray emission. The experiment is performed on the Jena 10 TW laser system in IOQ, Germany. The main purpose is to measure the time-resolved soft X-ray spectrum, and study how a prepulse play an important role and enhance the X-ray emission as well as and pulse duration. We clarified the temporal behavior of X-ray emission from quartz plasma produced by intensive femtosecond 800 nm laser pulse, and obtained a quantitative pictures of the

  18. Model system for investigating laser-induced subcellular microeffects

    Science.gov (United States)

    Huettmann, Gereon; Serbin, Jesper; Radt, Benno; Lange, Bjoern I.; Birngruber, Reginald

    2001-07-01

    Background: Laser induced protein denaturation is of fundamental interest for understanding the mechanisms of laser tissue interaction. Conjugates of nanoabsorbers coupled to proteins are presented as a model system for investigating ultrafast protein denaturation. Irradiation of the conjugates using repetitive picosecond laser pulses, which are only absorbed by the nanoabsorbers, could result in effects with a spatial confinement of less than 100 nm. Materials and Methods: Experiments were done with bovine intestinal alkaline phosphates (aP) coupled to 15 nm colloidal gold. This complex was irradiated at 527 nm wavelength and 35 ps pulse width with a varying number of pulses ranging form one up to 104. The radiant exposure per pulse was varied form 2 mJ/cm2 to 50 mJ/cm2. Denaturation was detected as a loss of protein function with the help of the fluorescence substrate 4MUP. Results and discussion: Irradiation did result in a steady decrease of the aP activity with increasing radiant exposures and increasing number of pulses. A maximal inactivation of 80% was reached with 104 pulses and 50 mJ/cm2 per pulse. The temperature in the particles and the surrounding water was calculated using Mie's formulas for the absorption of the nanometer gold particles and ana analytical solution of the equations for heat diffusion. With 50 mJ/cm2, the particles are heated above the melting point of gold. Since the temperature calculations strongly depend on changes in the state of matter of the particles and water, a very sophisticated thermal model is necessary to calculate exact temperatures. It is difficult to identify one of the possible mechanisms, thermal denaturation, photochemical denaturation or formation of micro bubbles from the dependance of the inactivation on pulse energy and number of applied pulses. Therefore, experiments are needed to further elucidate the damage mechanisms. In conclusion, denaturing proteins irreversibly via nanoabsorbers using picosecond laser

  19. Influence of net gain on the statistical fluctuation in a single-mode laser system

    Institute of Scientific and Technical Information of China (English)

    Qinghua Cheng; Dahai Xu; Li Cao; Dajin Wu

    2006-01-01

    @@ Using linear approximation method, we calculate the intensity correlation time of a single-mode laser driven by both colored pump noise with signal modulation and the quantum noise with cross-correlation between its real and imaginary parts, and analyze the influence of the net gain coefficient a0 on the statistical fluctuation of the laser system. It is found that for the case that the colored pump noise is long time correlated, the main factor influencing the statistical fluctuation of the laser system is a0, and the frequency of the modulation signal has negligible effect on the statistical fluctuation of the laser system.

  20. Programmable Control of the Pulse Repetition Rate in the Multiwave Strontium Vapor Laser System

    Directory of Open Access Journals (Sweden)

    Soldatov Anatoly

    2016-01-01

    Full Text Available The aim of the present work was the development of laser systems for ablation of biological tissues with a programmable control over the lasing pulse repetition rate in a wide range. A two-stage laser system consisting of a master oscillator and a power amplifier based on strontium vapor laser has been developed. The operation of the laser system in a single-pulse mode operation, multipulse mode operation, and with a pulse repetition rate up to 20 kHz has been technically implemented. The possibility of a bone tissue ablation with no visible thermal damage is shown.

  1. Method and system for advancement of a borehole using a high power laser

    Energy Technology Data Exchange (ETDEWEB)

    Moxley, Joel F.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Zediker, Mark S.

    2014-09-09

    There is provided a system, apparatus and methods for the laser drilling of a borehole in the earth. There is further provided with in the systems a means for delivering high power laser energy down a deep borehole, while maintaining the high power to advance such boreholes deep into the earth and at highly efficient advancement rates, a laser bottom hole assembly, and fluid directing techniques and assemblies for removing the displaced material from the borehole.

  2. Portable semiconductor laser system to stop internal bleeding

    Science.gov (United States)

    Rediker, Robert H.; Durville, Frederic M.; Cho, George; Boll, James H.

    1995-03-01

    One significant cause of death during a sever trauma (gun wound or stab wound) is internal bleeding. A semiconductor diode laser system has been used in in vitro studies of cauterizing veins and arteries to stop bleeding. The conditions of laparoscopic surgery, including bleeding conditions (blood flow and pressure), are simulated. Results have been obtained both with and without using a hemostat (e.g., forceps) to temporarily stop the bleeding prior to the cautery. With the hemostat and a fiber-coupled 810-nm laser, blood vessels of up to 5 mm diameter were cauterized with an 8 W output from the fiber. Great cautions must be used in extrapolating from these in vitro results, since the exact conditions of bleeding in a living being are impossible to exactly reproduce in a laboratory in-vitro experiment. In a living being, when blood flow stops the cessation of nourishment to the vessels results in irreversible physiological changes. Also, the blood itself is different from blood in a living being because an anti-clotting agent (heparin) was added in order to inhibit the blood's natural tendency to coagulate.

  3. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    OpenAIRE

    2016-01-01

    Richard Torbeck,1 Richard Bankowski,2 Sarah Henize,3 Nazanin Saedi,11Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 2Cynosure, Inc, Westford, MA, 3Huron Consulting Group, Chicago, IL, USABackground and objectives: The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser availa...

  4. Vacuum laser acceleration using a radially polarized CO sub 2 laser beam

    CERN Document Server

    Liu, Y; He, P

    1999-01-01

    Utilizing the high-power, radially polarized CO sub 2 laser and high-quality electron beam at the Brookhaven Accelerator Test Facility, a vacuum laser acceleration scheme is proposed. In this scheme, optics configuration is simple, a small focused beam spot size can be easily maintained, and optical damage becomes less important. At least 0.5 GeV/m acceleration gradient is achievable by 1 TW laser power.

  5. Laser-assisted skin closure at 1.32 microns: the use of a software-driven medical laser system

    Science.gov (United States)

    Dew, Douglas K.; Hsu, Tung M.; Hsu, Long S.; Halpern, Steven J.; Michaels, Charles E.

    1991-06-01

    This study investigated the use of a computerized 1 .3 micron Nd:YAG laser to seal approximated wound edges in pig skin. The medical laser system used was the DLS Type 1 , 1 .32 micron Nd:YAG laser (Laser Surgery Software, Inc.). The purpose of this study was to evaluate the effectiveness of laser assisted skin closure using the DLS YAG laser in a large animal model. Effectiveness was judged on the basis of wound dehiscence, infection, unusual healing result and consistency of results. Comparative cosmetic result was also evaluated. In this study, the DLS YAG laser was used to close scalpel-induced, full-thickness wounds. The pig model was chosen for its many integumentary similarities to man. Controls included scalpel-induced wounds closed using suture, staple and some with norepair. After adequate anesthesia was achieved, the dorsum of Yucutan pigs (approximately 75- 100 pounds) each was clipped with animal hair clippers from the shoulder area to the hind legs. The area was then shaved with a razor blade, avoiding any inadvertent cuts or abrasions of the skin. The dorsum was divided into four rows of four parallel incisions made by a #15 scalpel blade. Full-thickness incisions, 9 cm long, were placed over the dorsum of the pigs and then closed either with one loosely approximating Prolene" suture (the "no repair' group), multiple interrupted 6-0 nylon sutures, staples or laser. The experimental tissue sealing group consisted of 1 69 laser assisted closures on 1 3 pigs. Sutured control wounds were closed with 6-0 nylon, full thickness, simple, interrupted sutures. Eight sutures were placed 1 cm apart along the 9 cm incision. Stapled control wounds were approximated using two evenly spaced 3-0 VicryP' sub-dermal sutures and the dermis closed using Proximate' skin staples. Eight staples were placed 1 cm apart along the 9 cm incision. The no-repair incisions were grossly approximated using a single 2-0 Prolene full thickness, simple, interrupted suture located at the

  6. Micron-Accurate Laser Fresnel-Diffraction Ranging System

    Science.gov (United States)

    Lehner, David; Campbell, Jonathan; Smith, Kelly; Sanders, Alvin; Allison, Stephen; Smaley, Larry

    2008-01-01

    Two versions of an optoelectronic system undergoing development are depicted. The system is expected to be capable of measuring a distance between 2 and 10 m with an error of no more than 1 micrometer. The system would be designed to exploit Fresnel diffraction of a laser beam. In particular, it would be designed to take advantage of the fact that a Fresnel diffraction pattern is ultrasensitive to distance. The two versions would differ in the following respects: In version 1, the focus of the telescope would be in the Fresnel region, and the telescope would have a small depth of focus. As a consequence, the Fresnel pattern would be imaged directly onto the photodetector array; in version 2, a multielement lens module would displace the Fresnel region from the vicinity of the pinhole to the vicinity of the optical receiver. As the distance to be measured varied, the location of the receiver relative to the displaced Fresnel-diffraction region would vary, thereby causing the Fresnel diffraction pattern on the focal plane to vary. The multielement lens module would also correct for aberrations. The processing of the digitized Fresnel diffraction pattern in the computer might be accelerated by using only parts of the pattern or even only one small part - the central pixel. As the distance from the pinhole increased, the central pixel would rapidly cycle between maximum and minimum light intensity. This in itself would not be sufficient to uniquely determine the distance. However, by varying the size of the pinhole or the wavelength of the laser, one could obtain a second cycle of variation of intensity that, in conjunction with the first cycle, could enable a unique determination of distance. Alternatively, for a single wavelength and a single pinhole size, it should suffice to consider the data from only two different key pixels in the Fresnel pattern.

  7. The state of protoplanetary material 10 Myr after stellar formation: circumstellar disks in the TW Hydrae association

    CERN Document Server

    Uchida, K I; Hartmann, L; Kemper, F; Forrest, W J; Watson, D M; D'Alessio, P; Chen, C H; Furlan, E; Sargent, B; Brandl, B R; Herter, T L; Morris, P; Myers, P C; Najita, J R; Sloan, G C; Barry, J; Green, J; Keller, L D; Hall, P

    2004-01-01

    We have used the Spitzer Infrared Spectrograph to observe seven members of the TW Hya association, the nearest stellar association whose age ($\\sim$ 10 Myr) is similar to the timescales thought to apply to planet formation and disk dissipation. Only two of the seven targets display infrared excess emission, indicating that substantial amounts of dust still exist closer to the stars than is characteristic of debris disks; however, in both objects we confirm an abrupt short-wavelength edge to the excess, as is seen in disks with cleared-out central regions. The mid-infrared excesses in the spectra of Hen 3-600 and TW Hya include crystalline silicate emission features, indicating that the grains have undergone significant thermal processing. We offer a detailed comparison between the spectra of TW Hya and Hen 3-600, and a model that corroborates the spectral shape and our previous understanding of the radial structure of these protoplanetary disks.

  8. High-power green diode laser systems for biomedical applications

    DEFF Research Database (Denmark)

    Müller, André

    Due to their unique characteristics, diode lasers are increasingly attractive for numerous applications. For example, in the biomedical field the provided output power, spatial quality, and wavelength coverage of diode lasers has enabled their applications in, e.g., dermatology, diffuse spectrosc......Due to their unique characteristics, diode lasers are increasingly attractive for numerous applications. For example, in the biomedical field the provided output power, spatial quality, and wavelength coverage of diode lasers has enabled their applications in, e.g., dermatology, diffuse......, the obtained results clearly strengthen the application potential of diode lasers, including the biomedical field....

  9. Upgrading NASA/DOSE laser ranging system control computers

    Science.gov (United States)

    Ricklefs, Randall L.; Cheek, Jack; Seery, Paul J.; Emenheiser, Kenneth S.; Hanrahan, William P., III; Mcgarry, Jan F.

    1993-01-01

    Laser ranging systems now managed by the NASA Dynamics of the Solid Earth (DOSE) and operated by the Bendix Field Engineering Corporation, the University of Hawaii, and the University of Texas have produced a wealth on interdisciplinary scientific data over the last three decades. Despite upgrades to the most of the ranging station subsystems, the control computers remain a mix of 1970's vintage minicomputers. These encompass a wide range of vendors, operating systems, and languages, making hardware and software support increasingly difficult. Current technology allows replacement of controller computers at a relatively low cost while maintaining excellent processing power and a friendly operating environment. The new controller systems are now being designed using IBM-PC-compatible 80486-based microcomputers, a real-time Unix operating system (LynxOS), and X-windows/Motif IB, and serial interfaces have been chosen. This design supports minimizing short and long term costs by relying on proven standards for both hardware and software components. Currently, the project is in the design and prototyping stage with the first systems targeted for production in mid-1993.

  10. Waveguide and articulated arm for Er:YAG laser system: shape and depth of laser cavity in hard dental tissues

    Science.gov (United States)

    Jelinkova, Helena; Dostalova, Tatjana; Miyagi, Mitsunobu; Wang, You; Shi, Yi-Wei; Dolezalova, Libuse; Hamal, Karel; Krejsa, Otakar; Kubelka, Jiri; Prochazka, Stanislav

    1998-04-01

    The aim of our study was to verify the efficiency of delivery systems for Er:YAG laser radiation which could be used in dentistry. The influence of increasing energy and number of pulses on a profile and depth of drilled holes was investigated. Er:YAG laser was operating in a free-running mode, generating a length of pulses 200 microsecond with a maximum energy of 500 mJ. The delivery systems investigated were an articulated arm and a fluorocarbon polymer-coated silver hollow glass waveguide. The prepared hard tissues were a sliced part of enamel, dentine and ivory. The laser radiation was directed on them by focusing optics (CaF2 lens) together with the cooling water to ensure that the tissues will not be burned. For the evaluation of shapes, depth and profiles of the prepared cavities the metallographic microscope, x-ray microtomograph and scanning electron microscope were used. From the results it was observed that the profile and depth of the cavities prepared by the laser radiation delivered by the various systems (waveguide or articulated arm) are not the same. The laser radiation delivered by waveguide produces a larger diameter cavity with a lower depth. The holes are smoother and without side effects.

  11. Subpicosecond vacuum ultraviolet laser system for advanced materials processing

    Science.gov (United States)

    Kubodera, Shoichi; Taniguchi, Yuta; Hosotani, Akira; Katto, Masahito; Yokotani, Atsushi; Miyanaga, Noriaki; Mima, Kunioki

    2007-02-01

    We have been developing the vacuum ultraviolet (VUV) light sources and novel applications using such short wavelength emission sources. High quality amorphous Si thin films were successfully produced at room temperature as a result of photo-dissociation of SiH 4 gas by using an Ar II* excimer lamp irradiation at 126 nm. To enhance such novel VUV processing applications, a compact VUV amplifier at 126 nm was developed by use of the optical-field-ionization (OFI) electrons. The gain-length product around 5 was obtained as a result of the optical feedback by using a VUV mirror. This amplifier was operated in a table-top size with a high repetition rate up to several kHz, which should be appropriate for any process applications. We also describe the schematic concept of the ultrashort pulse high-intensity VUV laser system at 126 nm with a pulse width of 100 fs.

  12. Efficient active depth sensing by laser speckle projection system

    Science.gov (United States)

    Yin, Xuanwu; Wang, Guijin; Shi, Chenbo; Liao, Qingmin

    2014-01-01

    An active depth sensing approach by laser speckle projection system is proposed. After capturing the speckle pattern with an infrared digital camera, we extract the pure speckle pattern using a direct-global separation method. Then the pure speckles are represented by Census binary features. By evaluating the matching cost and uniqueness between the real-time image and the reference image, robust correspondences are selected as support points. After that, we build a disparity grid and propose a generative graphical model to compute disparities. An iterative approach is designed to propagate the messages between blocks and update the model. Finally, a dense depth map can be obtained by subpixel interpolation and transformation. The experimental evaluations demonstrate the effectiveness and efficiency of our approach.

  13. An active reflector antenna using a laser angle metrology system

    Institute of Scientific and Technical Information of China (English)

    Yong Zhang; Jie Zhang; De-Hua Yang; Guo-Hua Zhou; Ai-Hua Li; Guo-Ping Li

    2012-01-01

    An active reflector is one of the key technologies for constructing large telescopes,especially for millimeter/sub-millimeter radio telescopes.This article introduces a new efficient laser angle metrology system for an active reflector antenna on large radio telescopes.Our experiments concentrate on developing an active reflector for improving the detection precisions and the maintenance of the surface shape in real time on the 65-meter prototype radio telescope constructed by Nanjing Institute of Astronomical Optics and Technology (NIAOT; http://65m.shao.cas.cn/).The test results indicate that the accuracy of the surface shape segmentation and maintenance has the dimensions of microns,and the time-response can be on the order of minutes.Our efforts proved to be workable for sub-millimeter radio telescopes.

  14. Laser stabilization using saturated absorption in a cavity QED system

    CERN Document Server

    Tieri, D A; Christensen, Bjarke T R; Thomsen, J W; Holland, M J

    2015-01-01

    We consider the phase stability of a local oscillator (or laser) locked to a cavity QED system comprised of atoms with an ultra-narrow optical transition. The atoms are cooled to millikelvin temperatures and then released into the optical cavity. Although the atomic motion introduces Doppler broadening, the standing wave nature of the cavity causes saturated absorption features to appear, which are much narrower than the Doppler width. These features can be used to achieve an extremely high degree of phase stabilization, competitive with the current state-of-the-art. Furthermore, the inhomogeneity introduced by finite atomic velocities can cause optical bistability to disappear, resulting in no regions of dynamic instability and thus enabling a new regime accessible to experiments where optimum stabilization may be achieved.

  15. Research on laser induced particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Raab, Natascha; Buescher, Markus [Institut fuer Kernphysik (IKP), Forschungszentrum Juelich (Germany); Juelich Center for Hadron Physics (JCHP), Forschungszentrum Juelich (Germany); Willi, Oswald; Jung, Ralph [Institut fuer Laser-Plasma Physik (ILPP), Heinrich Heine Universitaet Duesseldorf (Germany); Seltmann, Michael [Institut fuer Kernphysik (IKP), Forschungszentrum Juelich (Germany); FH Aachen (Germany); Juelich Center for Hadron Physics (JCHP), Forschungszentrum Juelich (Germany)

    2009-07-01

    By directing a high-power, ultrashort laser pulse onto a thin foil, it is now possible to produce electron, proton and ion beams. However, for realizing reliable laser-driven accelerators one must still overcome fundamental and technological limitations. One current challenge is to continuously provide mass-limited targets into the laser focus in which its energy can be effectively converted into kinetic energy of the accelerated ions. IKP and ILPP have initiated a corresponding joint project based on a worldwide unique frozen pellet target that can provide a regular flux of frozen spheres of e.g. H2, N2, Ar and Xe, and the 100-TW laser system PULSAR at ILPP. As a first step measurements are carried out with conventional gas and foil targets. These measurements include detector developement for fast particle detection and magnetic focusing of the particle beam as well as optical probing of the plasma itself, in order to better understand the ion-acceleration mechanisms. The talk outlines the status of the research and the results of the first measurements.

  16. Tunable CO2 laser system with subnanosecond-pulse-train output

    Science.gov (United States)

    Kimura, W. D.

    2017-02-01

    A CO2 laser system has been demonstrated that generates a train of subnanosecond pulses tunable over the P and R branches of the CO2 laser spectrum at 9-11 μm. It utilizes optical free induction decay to generate a single 100-ps laser pulse from a tunable transverse-excited-atmospheric CO2 laser. This laser pulse is injection-seeded into a high-pressure CO2 oscillator whose output consists of a train of amplified 100-ps pulses with maximum pulse energy of 30 mJ, corresponding to a peak power of 300 MW. The 100-ps, tunable, infrared laser pulses are needed for a new technique to remotely detect atmospheric gaseous molecules, which relies on the train of CO2 laser pulses selectively exciting the target molecules whose presence is then revealed using a separate terahertz probe beam.

  17. Circularly polarized laser emission induced in isotropic and achiral dye systems

    Science.gov (United States)

    Cerdán, Luis; García-Moreno, Sara; Costela, Angel; García-Moreno, Inmaculada; de La Moya, Santiago

    2016-06-01

    The production of efficient, tunable, and switchable circularly polarized laser emission would have far reaching implications in optical communications or biophotonics. In this work, it is demonstrated the direct generation of circularly polarized (CP) laser emission in achiral and isotropic dye laser systems without the use of extracavity polarizing elements, and without resorting to chiral dyes, chiral liquid crystal matrices, or interferometric methods. The origin of this ellipticity arises from the dynamic birefringence induced by the strong and polarized laser pumping and the subsequent orientation anisotropy of the excited molecular dipoles. A complete polarimetric characterization of the polarization state of conventional dye laser oscillators as a function of different experimental parameters is performed and it is shown that the generated light always possesses a certain level of circularity that changes in a distinctive way with pump energy and polarization. These results demonstrate that it is possible to generate and modulate CP laser light from efficient and photostable conventional laser dyes.

  18. Contamination and Radiation Effects on Nonlinear Crystals for Space Laser Systems

    Science.gov (United States)

    Abdeldayem, Hossain A.; Dowdye, Edward; Jamison, Tracee; Canham, John; Jaeger, Todd

    2005-01-01

    Space Lasers are vital tools for NASA s space missions and military applications. Although, lasers are highly reliable on the ground, several past space laser missions proved to be short-lived and unreliable. In this communication, we are shedding more light on the contamination and radiation issues, which are the most common causes for optical damages and laser failures in space. At first, we will present results based on the study of liquids and subsequently correlate these results to the particulates of the laser system environment. We present a model explaining how the laser beam traps contaminants against the optical surfaces and cause optical damages and the role of gravity in the process. We also report the results of the second harmonic generation efficiency for nonlinear optical crystals irradiated with high-energy beams of protons. In addition, we are proposing to employ the technique of adsorption to minimize the presence of adsorbing molecules present in the laser compartment.

  19. A Detailed Evaluation of a Laser Triangulation Ranging System for Mobile Robots

    Science.gov (United States)

    1983-08-01

    A RPI TECHNICAL REPORT MP-82 A DETAILED EVALUATION OF A LASER - TRIANGULATION RANGING SYSTEM FOR MOBILE ROBOTS by Thomas J. Clement Contract MDA-903...Polytechnic Institute Technical Report MP-79, Troy, N.Y., May 1982. 9. McNellis, T., "Evaluation of a Laser Triangulation Ranging System for Mobile Robots ." Rensselaer

  20. A vision-based system for fast and accurate laser scanning in robot-assisted phonomicrosurgery.

    Science.gov (United States)

    Dagnino, Giulio; Mattos, Leonardo S; Caldwell, Darwin G

    2015-02-01

    Surgical quality in phonomicrosurgery can be improved by open-loop laser control (e.g., high-speed scanning capabilities) with a robust and accurate closed-loop visual servoing systems. A new vision-based system for laser scanning control during robot-assisted phonomicrosurgery was developed and tested. Laser scanning was accomplished with a dual control strategy, which adds a vision-based trajectory correction phase to a fast open-loop laser controller. The system is designed to eliminate open-loop aiming errors caused by system calibration limitations and by the unpredictable topology of real targets. Evaluation of the new system was performed using CO(2) laser cutting trials on artificial targets and ex-vivo tissue. This system produced accuracy values corresponding to pixel resolution even when smoke created by the laser-target interaction clutters the camera view. In realistic test scenarios, trajectory following RMS errors were reduced by almost 80 % with respect to open-loop system performances, reaching mean error values around 30 μ m and maximum observed errors in the order of 60 μ m. A new vision-based laser microsurgical control system was shown to be effective and promising with significant positive potential impact on the safety and quality of laser microsurgeries.

  1. The Laboratory for Laser Energetics’ Hydrogen Isotope Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Shmayda, W.T., E-mail: wshm@lle.rochester.edu; Wittman, M.D.; Earley, R.F.; Reid, J.L.; Redden, N.P.

    2016-11-01

    The University of Rochester’s Laboratory for Laser Energetics has commissioned a hydrogen Isotope Separation System (ISS). The ISS uses two columns—palladium on kieselguhr and molecular sieve—that act in a complementary manner to separate the hydrogen species by mass. The 4-sL per day throughput system is compact and has no moving parts. The columns and the attendant gas storage and handling subsystems are housed in a 0.8 -m{sup 3} glovebox. The glovebox uses a helium cover gas that is continuously processed to extract oxygen and water vapor that permeates through the glovebox gloves and any tritium that is released while attaching or detaching vessels to add feedstock to or drawing product from the system. The isotopic separation process is automated and does not require manual intervention. A total of 315 TBq of tritium was extracted from 23.6 sL of hydrogen with tritium purities reaching 99.5%. Deuterium was the sole residual component in the processed gas. Raffinate contained 0.2 TBq of activity was captured for reprocessing. The total emission from the system to the environment was 0.4 GBq over three weeks.

  2. Stochastic bifurcation in a driven laser system: experiment and theory.

    Science.gov (United States)

    Billings, Lora; Schwartz, Ira B; Morgan, David S; Bollt, Erik M; Meucci, Riccardo; Allaria, Enrico

    2004-08-01

    We analyze the effects of stochastic perturbations in a physical example occurring as a higher-dimensional dynamical system. The physical model is that of a class- B laser, which is perturbed stochastically with finite noise. The effect of the noise perturbations on the dynamics is shown to change the qualitative nature of the dynamics experimentally from a stochastic periodic attractor to one of chaoslike behavior, or noise-induced chaos. To analyze the qualitative change, we apply the technique of the stochastic Frobenius-Perron operator [L. Billings et al., Phys. Rev. Lett. 88, 234101 (2002)] to a model of the experimental system. Our main result is the identification of a global mechanism to induce chaoslike behavior by adding stochastic perturbations in a realistic model system of an optics experiment. In quantifying the stochastic bifurcation, we have computed a transition matrix describing the probability of transport from one region of phase space to another, which approximates the stochastic Frobenius-Perron operator. This mechanism depends on both the standard deviation of the noise and the global topology of the system. Our result pinpoints regions of stochastic transport whereby topological deterministic dynamics subjected to sufficient noise results in noise-induced chaos in both theory and experiment.

  3. Laser adaptive holographic system for microweighing of nanoobjects

    Energy Technology Data Exchange (ETDEWEB)

    Romashko, R V; Efimov, T A; Kul' chin, Yu N [Institute for Automation and Control Processes, Far-Eastern Branch, Russian Academy of Sciences, Vladivostok (Russian Federation)

    2014-03-28

    A system for measuring the mass of micro- and nanoobjects based on resonance microweighing using the principles of adaptive holographic interferometry is proposed and experimentally implemented. The sensitive element of the system is a microcantilever to which the objects to be weighted are attached. The eigenoscillations of the microcantilever are excited with a laser pulse. The detection of oscillations is implemented using the adaptive holographic interferometer, the key element of which, the dynamic hologram, is formed in the photorefractive crystal CdTe. The detected variation in mass of the particles, attached to the microcantilever, amounted to (420 ± 9) × 10{sup -12} g, the measurement error being 8.5 × 10{sup -12} g. The sensitivity of the measurement system is 1.7 × 10{sup -12} Hz g{sup -1}. The possibility of increasing the sensitivity of the system by 6.5 × 10{sup 6} times and reducing the mass detection threshold by 1.5 × 10{sup 7} times by microcantilevers of submicron size is experimentally demonstrated. (nanoobjects)

  4. Multikilowatt TEA-CO2 laser system for molecular laser isotope separation

    Science.gov (United States)

    Ronander, Einar; Rohwer, Erich G.

    1993-05-01

    Laser-induced chemistry has received much attention in the past few years. The economics of such applications are dominated by the costs of photons and the quantum yield of the specific reaction. For a typical multiple-IR-photon process the quantum yield can be as low as 10-4 which emphasizes the importance of reducing the cost of laser photons. Based on 1982 technology, CO2 TEA laser operating costs were approximately $100/watt per year for a laser with an electrical efficiency of 6% and an average power of more than 100 kW. Capital costs dominated the energy cost as well as the maintenance and labor costs. At the South African Atomic Energy Corp. we have been involved in the development of high pulse frequency, high average power TEA-CO2 lasers for the application in the field of laser-induced chemistry. Much of the attention, however, has been focused on the application to separate the isotopes of uranium via a multiwavelength infrared irradiation scheme. The progress that has been made towards the establishment of CO2-lasers and laser chains for industrial use has been quite outstanding.

  5. TW Hya Association Membership and New WISE-detected Circumstellar Disks

    CERN Document Server

    Schneider, Adam; Song, Inseok

    2012-01-01

    We assess the current membership of the nearby, young TW Hydrae Association and examine newly proposed members with the Wide-field Infrared Survey Explorer (WISE) to search for infrared excess indicative of circumstellar disks. Newly proposed members TWA 30A, TWA 30B, TWA 31, and TWA 32 all show excess emission at 12 and 22 \\mum providing clear evidence for substantial dusty circumstellar disks around these low-mass, ~8 Myr old stars that were previously shown to likely be accreting from circumstellar material. TWA 30B shows large amounts of self-extinction, likely due to an edge-on disk geometry. We also confirm previously reported circumstellar disks with WISE, and determine a 22 \\mum excess fraction of 42+/- 9% based on our results.

  6. A 10-Hz terawatt class Ti:sapphire laser system: Development and applications

    Indian Academy of Sciences (India)

    A K Sharma; J Smedley; T Tsang; T Rao

    2010-11-01

    We developed a two-stage Ti:sapphire laser system to generate 16 mJ/80 fs laser pulses at a pulse repetition rate of 10 Hz. The key deriver for the present design is implementing a highly efficient symmetric confocal pre-amplifier and employing a simple, inexpensive synchronization scheme relying only on a commercial digital delay generator. We characterized the amplified pulses in spatial, spectral and temporal domains. The laser system was used to investigate various nonlinear optical processes, and to modify the optical properties of metal and semiconductor surfaces. We are currently building a third amplifier to boost the laser power to the multi-terawatt range.

  7. Time-Delayed Feedback Control in a Single-Mode Laser System

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of time-delayed feedback control in a single-mode laser system is investigated. Using the small time delay approximation, the analytic expression of the stationary probability distribution function of the laser field is obtaincd. The mean, normalized variance and skewness of the steady-state laser intensity are calculated. It is found that the time-delayed feedback control can suppress the intensity fluctuation of the laser system. The numerical simulations are in good agreement with the approximate analytic results.

  8. KINEMATICS OF THE CO GAS IN THE INNER REGIONS OF THE TW Hya DISK

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfeld, Katherine A.; Qi Chunhua; Andrews, Sean M.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Corder, Stuartt A. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Lin Shinyi [Department of Physics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Hughes, A. M. [Department of Astronomy, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720 (United States); D' Alessio, Paola [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 72-3 (Xangari), 58089 Morelia, Michoacan (Mexico); Ho, P. T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China)

    2012-10-01

    We present a detailed analysis of the spatially and spectrally resolved {sup 12}CO J = 2-1 and J = 3-2 emission lines from the TW Hya circumstellar disk, based on science verification data from the Atacama Large Millimeter/submillimeter Array (ALMA). These lines exhibit substantial emission in their high-velocity wings (with projected velocities out to 2.1 km s{sup -1}, corresponding to intrinsic orbital velocities >20 km s{sup -1}) that trace molecular gas as close as 2 AU from the central star. However, we are not able to reproduce the intensity of these wings and the general spatio-kinematic pattern of the lines with simple models for the disk structure and kinematics. Using three-dimensional non-local thermodynamic equilibrium molecular excitation and radiative transfer calculations, we construct some alternative models that successfully account for these features by modifying either (1) the temperature structure of the inner disk (inside the dust-depleted disk cavity; r < 4 AU), (2) the intrinsic (Keplerian) disk velocity field, or (3) the distribution of disk inclination angles (a warp). The latter approach is particularly compelling because a representative warped disk model qualitatively reproduces the observed azimuthal modulation of optical light scattered off the disk surface. In any model scenario, the ALMA data clearly require a substantial molecular gas reservoir located inside the region where dust optical depths are known to be substantially diminished in the TW Hya disk, in agreement with previous studies based on infrared spectroscopy. The results from these updated model prescriptions are discussed in terms of their potential physical origins, which might include dynamical perturbations from a low-mass companion with an orbital separation of a few AU.

  9. Setup of a beam control system for high power laser system at DLR

    Science.gov (United States)

    Buske, Ivo; Walther, Andreas

    2016-10-01

    Different types of high power or high energy lasers in the multi kW class are currently available or are under development with promising progress reports. A major challenge is to deliver as much as possible of the available power onto a small and fast moving target over a long distance through a disturbing atmosphere. High resolution imaging is a common way to identify the category of targets dedication and to determine the spatial position relative to the observer. By illuminating the target with a laser the imaging system becomes more resilient towards ambient light and the exposure time can be reduced drastically. Fast and deterministic control loops are demanding for the moving parts in order to maintain a high accuracy for the pointing of the turret and aiming of the laser countermeasure system. Here, we report on the progress of such a beam control system developed at the Institute of Technical Physics of DLR. In an overview we present the beam control system and explain different sub-systems. Performance tests were taken at our test. At a distance we simulated various scenarios for probing the limits of the tracking and pointing accuracy with a target on a fast moving linear stage. We present first results of the beam control system performance.

  10. Superluminescent diode versus Fabry-Perot laser diode seeding in pulsed MOPA fiber laser systems for SBS suppression

    Science.gov (United States)

    Melo, M.; Sousa, J. M.; Salcedo, J. R.

    2015-03-01

    We demonstrate the use of a pulsed superluminescent diode (SLD) through direct current injection modulation as seeding source in a master oscillator power amplifier (MOPA) configuration when compared to a Fabry-Perot (FP) laser diode in the same system. The performance limitations imposed by the use of the Fabry-Perot lasers, caused by the backward high peak power pulses triggered due to stimulated Brillouin scattering (SBS) are not observed in the case of the SLD. Compared to conventional Fabry-Perot laser diodes, the SLD provides a smooth and broad output spectrum which is independent of the input pulse parameters. Moreover, the spectrum can be sliced and tailored to the application. Thus, free SBS operation is shown when using the SLD seeder in the same system, allowing for a significant increase on the extractable power and energy.

  11. Integrated control system of transverse flow CO II laser and its application

    Science.gov (United States)

    Liu, Juan; Tang, Xiahui; Zhang, Yang; Peng, Hao; Wang, Youqing

    2008-03-01

    Aiming to the special high power CO II laser surface treatment, the paper developed the integrated control system based on S7-200 PLC of transverse flow CO II laser. The selection of key technology and components, detection and control of signals, integrated control of complete circuit, technology of human machine interface and process control of system have been researched. Double closed loop power control system was realized, so that the stability of the laser power was in +/-2%. Also, the giving power can be controlled by the laser controller or by the processing machine, thus, the users can control the laser more efficiently when processing. A series of experiments have been performed on 5kW transverse flow CO II laser, the output laser power was stable at discharge current of 9A for 8 hours, and the maximal power was 5.42 kW. The new type of transverse flow CO II Laser with Integrated Control System has been applied for special laser cladding with power-modulating on the metallic surface of the oil industry production.

  12. Optical multiaccess free-space laser communication system

    Science.gov (United States)

    Jiang, Lun; Zhang, Li-Zhong; Wang, Chao; An, Yan; Hu, Yuan

    2016-08-01

    With urgent demand for an integrated information network and development of free-space laser communication technology, research on high-rate laser communication networking technology is vital. This study analyzed the technical difficulties related to space laser communication networking and proposed a laser communication networking solution. A wide-angle beam expander and dual-rotating prism group were incorporated into a multiaccess optical laser communication antenna. The wide-angle beam expander collects signal light from different directions; the dual-rotating prism group tracks different targets simultaneously. This paper presents an overall scheme allowing multiaccess free-space laser communications based on the optical antenna described and the associated relay optics and transceiver subsystems.

  13. Multiwavelength interferometry system for the Orion laser facility.

    Science.gov (United States)

    Patankar, S; Gumbrell, E T; Robinson, T S; Lowe, H F; Giltrap, S; Price, C J; Stuart, N H; Kemshall, P; Fyrth, J; Luis, J; Skidmore, J W; Smith, R A

    2015-12-20

    We report on the design and testing of a multiwavelength interferometry system for the Orion laser facility based upon the use of self-path matching Wollaston prisms. The use of UV corrected achromatic optics allows for both easy alignment with an eye-safe light source and small (∼ millimeter) offsets to the focal lengths between different operational wavelengths. Interferograms are demonstrated at wavelengths corresponding to first, second, and fourth harmonics of a 1054 nm Nd:glass probe beam. Example data confirms the broadband achromatic capability of the imaging system with operation from the UV (263 nm) to visible (527 nm) and demonstrates that features as small as 5 μm can be resolved for object sizes of 15 by 10 mm. Results are also shown for an off-harmonic wavelength that will underpin a future capability. The primary optics package is accommodated inside the footprint of a ten-inch manipulator to allow the system to be deployed from a multitude of viewing angles inside the 4 m diameter Orion target chamber.

  14. A single laser all fibre based optical sensor and switching system and method for measuring velocity in atmospheric air flow

    DEFF Research Database (Denmark)

    2013-01-01

    A system for measuring a velocity of tracer particle motion in a fluid comprising at least one laser emitter configured to emit a continuous wave laser beam and a plur ality of optical devices being configured to alternately receive a laser beam, focusing the laser beam onto a same probe volume c...

  15. ISS Efforts to Fully Utilize its Target Acquisition Capability Serves as an Analog for Future Laser Pointing Communications Systems

    Science.gov (United States)

    Jackson, Dan

    2017-01-01

    The ISS is an outstanding platform for developing, testing and refining laser communications systems for future exploration. A recent ISS project which improved ISS communications satellite acquisition performance proves the platform’s utility as a laser communications systems testbed.

  16. High-power solid-state lasers and high-energy-density physics at CAEP

    Energy Technology Data Exchange (ETDEWEB)

    Peng, H. S.; Zhang, W. Y. [China Academy of Engineering Physics, Mianyang, Sichuan (China)

    2006-07-15

    Significant progress has been made in high-power solid-state laser development and related laser fusion and strong-field studies at the CAEP (China Academy of Engineering Physics) in recent years. A Ti:sapphire laser system, SILEX-I, was completed early in 2004 and could deliver 26- fs pulses at 300TW to targets. The SILEX-I has been operated very stably since its completion for experiments in exploring a number of frontiers, demonstrating that it is the most powerful femtosecond Ti:sapphire laser for applications in the world. The SG-III Nd:glass laser facility has been under final design to meet the requirements from laser fusion applications and will produce 3- to 5-ns pulses at 0.35 {mu}m with an output energy of about 150 kJ. The eight-beamline TIL (technical integration line), the prototype of the SG-III laser facility, has been activated in the new laboratory in Mianyang and will be completed in 2006 for operation. The SG-II laser at the Shanghai Institute of Optics and Fine Mechanics has been operating as a major facility for experiments on fusion physics since 2001. Experiments on hohlraum and implosion physics have been conducted. Simultaneously, advanced plasma diagnostic technologies for implosion hydrodynamics have been developed.

  17. Drive laser system for the DC-SRF photoinjector at Peking University

    CERN Document Server

    Wang, Zhiwen; Lin, Lin; Zhao, Gang; Quan, Shengwen; Liu, Kexin; Chen, Jiaer

    2015-01-01

    Photoinjectors are widely used for linear accelerators as electron sources to generate high-brightness electron beam. Drive laser, which determines the timing structure and quality of the electron beam, is a crucial device of photoinjector. A new drive laser system has been designed and constructed for the upgraded 3.5-cell DC-SRF photoinjector at Peking University. The drive laser system consists of a 1064 nm laser oscillator, a four- stage amplifier, the second and fourth harmonic generators, the optical system to transfer the UV pulses to the photocathode, and the synchronization system. The drive laser system has been successfully applied in the stable operation of DC-SRF photoinjector and its performance meets the requirements. 266 nm laser with an average power close to 1W can be delivered to illuminate the Cs2Te photocathode and the instability is less than 5% for long time operation. The design consideration for improving the UV laser quality, a detailed description of laser system, and its performanc...

  18. Heat exchange and hydraulic resistance of compact laser mirror cooling systems

    Science.gov (United States)

    Shanin, Yu. I.; Shanin, O. I.

    2013-07-01

    The hydraulic resistance of cooling systems for laser mirrors and the heat exchange in them have been investigated experimentally. The data obtained have been generalized for several cooling systems with different porous elements.

  19. Evaluation of Laser Stabilization and Imaging Systems for LCLS-II - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Matthew; /Auburn U.

    2015-08-19

    This presentation covers data collected on two commercial laser stabilization systems, Guidestar-II and MRC, and two optical imaging systems. Additionally, general information about LCLS-II and how to go about continuing-testing is covered.

  20. Dye laser as a six-level system

    Energy Technology Data Exchange (ETDEWEB)

    Baczynski, A.; Kossakowski, A.; Marszalek, T.

    1977-01-01

    Stationary solutions of kinetic equations of dye lasers based on a six-level model of dye molecule were analyzed. Such a model is the simplest one to account for the participation of triplet states in generating a laser. The course of triplet losses versus pumping parameter can undergo a jump at threshold which leads to the jump of photon number in the cavity. The improvement of the laser performance of dye lasers by means of an additional triplet-triplet pumping is proposed.

  1. High power all-solid-state quasi-continuous-wave tunable Ti: sapphire laser system

    Institute of Scientific and Technical Information of China (English)

    Lei Zou; Xin Ding; Yue Zou; Hongmei Ma; Wuqi Wen; Peng Wang; Jianquan Yao

    2005-01-01

    This paper reports a high power, all-solid-state, quasi-continuous-wave tunable Ti:sapphire laser system pumped by laser diode (LD) pumped frequency-doubled Nd:YAG laser. The maximum tuned output power of 4.2 W (797 nm) and tuned average power of 3.7 W were achieved when fixing the Ti:sapphire broadband output power at 5.0 W and applying 750-850 nm broadband coated mirror.

  2. Spatial-Resolution Improvement in Optical Frequency Domain Reflectometry System Based on Tunable Linear Fiber Laser

    Energy Technology Data Exchange (ETDEWEB)

    Li Guoyu; Li Yan [Institute of Information Engineering, Handan College, Handan, 056005 (China); Zhao Peng, E-mail: guoyu_li@yahoo.cn [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China)

    2011-02-01

    In optical frequency domain reflectometry (OFDR) system, the spatial resolution is obtained by using the total frequency-sweep span of the tunable laser. However, in practice, the spatial resolution is severely limited by nonlinearity in the lightwave-frequency sweep of the tunable laser. A closed-loop PZT modulated DBR linear fiber laser is proposed to improve the spatial resolution of the OFDR system. Experimental results show that the spatial resolution of OFDR system has improved greatly. When the frequency sweep excursion is 66GHz and the fiber under test (FUT) is 7 m, the OFDR system has a spatial resolution of 1.5 m with open-loop PZT modulated laser. But the spatial resolution increases to 35 cm with closed-loop PZT modulated laser.

  3. A Laser System for the Spectroscopy of Highly-Charged Bismuth Ions

    CERN Document Server

    Albrecht, S; Siegel, C; Herschbach, N; Birkl, G

    2011-01-01

    We present and characterize a laser system for the spectroscopy on highly-charged ^209Bi^82+ ions at a wavelength of 243.87 nm. For absolute frequency stabilization, the laser system is locked to a near-infra-red laser stabilized to a rubidium transition line using a transfer cavity based locking scheme. Tuning of the output frequency with high precision is achieved via a tunable rf offset lock. A sample-and-hold technique gives an extended tuning range of several THz in the UV. This scheme is universally applicable to the stabilization of laser systems at wavelengths not directly accessible to atomic or molecular resonances. We determine the frequency accuracy of the laser system using Doppler-free absorption spectroscopy of Te_2 vapour at 488 nm. Scaled to the target wavelength of 244 nm, we achieve a frequency uncertainty of \\sigma_{244nm} = 6.14 MHz (one standard deviation) over six days of operation.

  4. 3D cavity detection technique and its application based on cavity auto scanning laser system

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-ling; LI Xi-bing; LI Fa-ben; ZHAO Guo-yan; QIN Yu-hui

    2008-01-01

    Ground constructions and mines are severely threatened by underground cavities especially those unsafe or inaccessible ones. Safe and precise cavity detection is vital for reasonable cavity evaluation and disposal. The conventional cavity detection methods and their limitation were analyzed. Those methods cannot form 3D model of underground cavity which is used for instructing the cavity disposal; and their precisions in detection are always greatly affected by the geological circumstance. The importance of 3D cavity detection in metal mine for safe exploitation was pointed out; and the 3D cavity laser detection method and its principle were introduced. A cavity auto scanning laser system was recommended to actualize the cavity 3D detection after comparing with the other laser detection systems. Four boreholes were chosen to verify the validity of the cavity auto scanning laser system. The results show that the cavity auto scanning laser system is very suitable for underground 3D cavity detection, especially for those inaccessible ones.

  5. Micron Size Laser-Wire System at the ATF Extraction Line, Recent Results and ATF-II Upgrade

    CERN Document Server

    Blair, G A; Boorman, G; Bosco, A; Deacon, L; Karataev, P; Howell, D; Nevay, L J; Corner, L; Delerue, N; Foster, B; Gannaway, F; Newman, M; Senanayake, R; Walczak, R; Hayano, H; Aryshev, A; Terunuma, N; Urakawa, J

    2010-01-01

    The KEK Accelerator test facility (ATF) extraction line laser-wire system has been upgraded last year allowing the measurement of micron scale transverse size electron beams. The most recent measurements using the upgraded system are presented. The ATF-II extraction line design call for the major upgrade of the existing laser-wire system. We report on the hardware upgrades, including the major hardware upgrades to the laser transport, the laser beam diagnostics line, and the mechanical control systems.

  6. AlGaInN laser diode technology and systems for defence and security applications

    Science.gov (United States)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lujca; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.

    2015-10-01

    AlGaInN laser diodes is an emerging technology for defence and security applications such as underwater communications and sensing, atomic clocks and quantum information. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries. Ridge waveguide laser diodes are fabricated to achieve single mode operation with optical powers up to 100mW with the 400-440nm wavelength range with high reliability. Visible free-space and underwater communication at frequencies up to 2.5GHz is reported using a directly modulated 422nm GaN laser diode. Low defectivity and highly uniform GaN substrates allow arrays and bars to be fabricated. High power operation operation of AlGaInN laser bars with up to 20 emitters have been demonstrated at optical powers up to 4W in a CS package with common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space or optical fibre system integration with a very small form-factor.

  7. Industrial fiber beam delivery system for ultrafast lasers: applications and recent advances

    Science.gov (United States)

    Eilzer, Sebastian; Funck, Max C.; Wedel, Björn

    2016-03-01

    Fiber based laser beam delivery is the method of choice for high power laser applications whenever great flexibility is required. For cw-lasers fiber beam delivery has long been established but has recently also become available for ultrafast lasers. Using micro-structured hollow core fibers that guide the laser beam mostly inside a hollow core, nonlinear effects and catastrophic damage that arise in conventional glass fibers can be avoided. Today, ultrafast pulses with several 100 μJ and hundreds of MW can be transmitted in quasi single mode fashion. In addition, the technology opens new possibilities for beam delivery systems as the pulse propagation inside the fiber can be altered on purpose. For example to shorten the pulse duration of picosecond lasers down into the femtosecond regime. We present a modular fiber beam delivery system for micromachining applications with industrial pico- and femtosecond lasers that is flexibly integrated into existing applications. Micro-structured hollow core fibers inside the sealed laser light cable efficiently guide high-power laser pulses over distances of several meters with excellent beam quality, while power, pulse duration and polarization are maintained. Robust and stable beam transport during dynamic operation as in robot or gantry systems will be discussed together with optional pulse compression.

  8. EFFECTS OF COLOURED NOISE IN A TWO-MODE LASER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    罗晓琴; 朱士群; 高伟建

    2001-01-01

    A homogeneously broadened two-mode laser system with multiplicative coloured noise is investigated when the mode coupling constant ξ=2. An analytical result is obtained when two-dimensional decoupling theory is applied to the system. The intensity auto-correlation function and effective eigenvalue of the laser system are calculated when the difference of pump parameters, multiplicative noise strength and noise correlation time are varied. It is shown that the multiplicative noise can enhance the fluctuations while the noise colour can reduce the fluctuations in the laser system.

  9. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    Science.gov (United States)

    Yatsuka, E.; Hatae, T.; Suitoh, S.; Ohara, M.; Hagita, K.; Inoue, K.; Bassan, M.; Walsh, M.; Itami, K.

    2016-01-01

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port.

  10. Comparison of SHR Mode IPL System with Alexandrite and Nd: YAG Lasers For Leg Hair Reduction

    Directory of Open Access Journals (Sweden)

    Şemsettin Karaca

    2012-12-01

    Full Text Available Objective: Multiple lasers and light sources are currently available for hair removal and many studies comparing efficacy and safety exist. SHR mode IPL is a technique that gives the total energy in divided doses with fewer side effects. We compared a SHR mode IPL system with alexandrite and Nd: YAG lasers for leg hair reductionMaterial and Methods: Twenty-five female participants with skin types II–IV, underwent treatment of unwanted hair on the cruris. Three selected areas were randomly treated with the SHR mode IPL system, Alexandrite laser and Nd: YAG laser in three sessions. Hair reduction was evaluated with digital photography by a blinded assessor every 6 weeks and 6 months after the last session. Pain severity, side effects and patient satisfaction analysis were also investigated. Results: Twenty-one participants completed the trial. The mean hair reductions in 6 weeks after the last treatment were 50% for the IPL system, 53% for Alexandrite and 39% for the Nd: YAG lasers. However after 6 months; 40%, 49% and 34% hair reduction was observed, respectively. The Alexandrite laser was the least painful system. Conclusion: Although there is no obvious advantage of one laser system over the others in terms of treatment outcome, the Alexandrite laser is still the most efficient and reliable way of hair removal in fair skinned individuals.

  11. Single top-quark production via $tW$, $tZq$, and $s$-channel with ATLAS and CMS

    CERN Document Server

    Finelli, Kevin Daniel; The ATLAS collaboration

    2017-01-01

    Analyses of single top-quark production in the $s$-channel, via $tW$ production, and via $tZq$ production are presented, showing the scope of recent ATLAS and CMS analysis of LHC data. Cross-section values and signal significance estimates are established, confirming good agreement with the most precise available fixed-order calculations for each production mode.

  12. Detection of H2D+: Measuring the Midplane Degree of Ionization in the Disks of DM Tauri and TW Hydrae

    NARCIS (Netherlands)

    Ceccarelli, C.; Dominik, C.; Lefloch, B.; Caselli, P.; Caux, E.

    2004-01-01

    We report the first detection of the ground transition of the ortho-H2D+ molecule toward one disk source, DM Tau, a tentative detection toward TW Hya, and an upper limit toward LkCa 15. The three observed sources possess young gas-rich disks with large CO depletion factors. We argue that the observe

  13. Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya: Constraining the disk gas mass

    CERN Document Server

    Thi, W F; Ménard, F; Woitke, P; Meeus, G; Riviere-Marichalar, P; Pinte, C; Howard, C D; Roberge, A; Sandell, G; Pascucci, I; Riaz, B; Grady, C A; Dent, W R F; Kamp, I; Duchêne, G; Augereau, J C; Pantin, E; Vandenbussche, B; Tilling, I; Williams, J P; Eiroa, C; Barrado, D; Alacid, J M; Andrews, S; Ardila, D R; Aresu, G; Brittain, S; Ciardi, D R; Danchi, W; Fedele, D; de Gregorio-Monsalvo, I; Heras, A; Huelamo, N; Krivov, A; Lebreton, J; Liseau, R; Martin-Zaidi, C; Mendigutía, I; Montesinos, B; Mora, A; Morales-Calderon, M; Nomura, H; Phillips, N; Podio, L; Poelman, D R; Ramsay, S; Rice, K; Solano, E; Walker, H; White, G J; Wright, G

    2010-01-01

    Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [OI] and [CII] as part of the Open-time large program GASPS. We complement this with continuum data and ground-based 12CO 3-2 and 13CO 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [OI] line at 63 micron. The other lines that were observed, [OI] at 145 micron and [CII] at 157 micron, are not detected. No extended emission has been found. Preliminary modeling of the photometric...

  14. Particle damage sources for fused silica optics and their mitigation on high energy laser systems.

    Science.gov (United States)

    Bude, J; Carr, C W; Miller, P E; Parham, T; Whitman, P; Monticelli, M; Raman, R; Cross, D; Welday, B; Ravizza, F; Suratwala, T; Davis, J; Fischer, M; Hawley, R; Lee, H; Matthews, M; Norton, M; Nostrand, M; VanBlarcom, D; Sommer, S

    2017-05-15

    High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of damage to critical fused silica optics, which grows rapidly upon exposure to additional laser pulses. Much progress has been made in eliminating damage precursors in as-processed fused silica optics (the advanced mitigation process, AMP3), and very high damage resistance has been demonstrated in laboratory studies. However, the full potential of these improvements has not yet been realized in actual laser systems. In this work, we explore the importance of additional damage sources-in particular, particle contamination-for fused silica optics fielded in a high-performance laser environment, the National Ignition Facility (NIF) laser system. We demonstrate that the most dangerous sources of particle contamination in a system-level environment are laser-driven particle sources. In the specific case of the NIF laser, we have identified the two important particle sources which account for nearly all the damage observed on AMP3 optics during full laser operation and present mitigations for these particle sources. Finally, with the elimination of these laser-driven particle sources, we demonstrate essentially damage free operation of AMP3 fused silica for ten large optics (a total of 12,000 cm(2) of beam area) for shots from 8.6 J/cm(2) to 9.5 J/cm(2) of 351 nm light (3 ns Gaussian pulse shapes). Potentially many other pulsed high energy laser systems have similar particle sources, and given the insight provided by this study, their identification and elimination should be possible. The mitigations demonstrated here are currently being employed for all large UV silica optics on the National Ignition Facility.

  15. THE DEVELOPMENT OF A LASER BASED LOCAL POSITIONING SYSTEM

    Directory of Open Access Journals (Sweden)

    A.J. Lubbe

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: There is no cheap, accurate device available with which the position of a slow moving object , such as a lawnmower cutting lawn, can be determined. If such a positioning system were available it would be possible to develop numerous programmable moving machines that can be taught computer-wise to perform daily chores. In this paper a prototype local positioning system, which could possibly be applied to determine the absolute position in relation to a fixed point for slow moving objects, is discussed. Accuracy, shortcomings and possible improvements of a laser based prototype are discussed.

    AFRIKAANSE OPSOMMING: Daar is geen goedkoop, akkurate wyse beskikbaar om die posisie van 'n stadigbewegende voorwerp soos 'n grassnyer oor 'n grasperk te bepaal nie. Indien so 'n posisioneringstelsel wei beskikbaar sou wees, sou dit moontlik wees om 'n groot verskeidenheid programmeerbare bewegende masjiene te ontwikkel wat rekenaargewys geleer kan word om alledaagse take te verrig. In hierdie artikel word 'n prototipe 10kale posisioneringstelsel bespreek wat moontlik aangewend kan word om die absolute posisie, ten opsigte van 'n vaste punt, van stadigbewegende voorwerpe te bepaal. Akkuraatheid, tekortkomings en moontlike verbeterings van 'n lasergebaseerde prototipestelsel word bespreek.

  16. Power-scalable, polarization-stable, dual-colour DFB fibre laser system for CW terahertz imaging

    DEFF Research Database (Denmark)

    Eichhorn, Finn; Pedersen, Jens Engholm; Jepsen, Peter Uhd

    -scalable, dual-colour, polarization-maintaining distributed feedback (DFB) fibre laser system with an inherent narrow linewidth from the DFB fibre laser oscillators. The laser system can be used as source in CW THz systems employing photomixing (optical heterodyning) for generation and detection...

  17. Diode-pumped laser with improved pumping system

    Science.gov (United States)

    Chang, Jim J.

    2004-03-09

    A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.

  18. The c-axis charge traveling wave in a coupled system of Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Hamdipour, M.

    2012-05-01

    We demonstrate a manifestation of the charge traveling wave along the c axis (TW) in current voltage characteristics of coupled Josephson junctions in high- T c superconductors. The branches related to the TW with different wavelengths are found for the stacks with different number of Josephson junctions at different values of system's parameters. Transitions between the TW branches and the outermost branch are observed. The electric charge in the superconducting layers and charge-charge correlation functions for TW and outermost branches show different behavior with bias current. We propose an experimental testing of the TW branching by microwave irradiation.

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

    Science.gov (United States)

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

    2016-08-01

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

  20. System technology for laser-assisted milling with tool integrated optics

    Science.gov (United States)

    Hermani, Jan-Patrick; Emonts, Michael; Brecher, Christian

    2013-02-01

    High strength metal alloys and ceramics offer a huge potential for increased efficiency (e. g. in engine components for aerospace or components for gas turbines). However, mass application is still hampered by cost- and time-consuming end-machining due to long processing times and high tool wear. Laser-induced heating shortly before machining can reduce the material strength and improve machinability significantly. The Fraunhofer IPT has developed and successfully realized a new approach for laser-assisted milling with spindle and tool integrated, co-rotating optics. The novel optical system inside the tool consists of one deflection prism to position the laser spot in front of the cutting insert and one focusing lens. Using a fiber laser with high beam quality the laser spot diameter can be precisely adjusted to the chip size. A high dynamic adaption of the laser power signal according to the engagement condition of the cutting tool was realized in order not to irradiate already machined work piece material. During the tool engagement the laser power is controlled in proportion to the current material removal rate, which has to be calculated continuously. The needed geometric values are generated by a CAD/CAM program and converted into a laser power signal by a real-time controller. The developed milling tool with integrated optics and the algorithm for laser power control enable a multi-axis laser-assisted machining of complex parts.

  1. Beam shaping design for compact and high-brightness fiber-coupled laser-diode system.

    Science.gov (United States)

    Yu, Junhong; Guo, Linui; Wu, Hualing; Wang, Zhao; Tan, Hao; Gao, Songxin; Wu, Deyong; Zhang, Kai

    2015-06-20

    Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. A compact and high-brightness fiber-coupled system has been designed based on a significant beam shaping method. The laser-diode stack consists of eight mini-bars and is effectively coupled into a standard 100 μm core diameter and NA=0.22 fiber. The simulative result indicates that the module will have an output power over 440 W. Using this technique, compactness and high-brightness production of a fiber-coupled laser-diode module is possible.

  2. Performance and production requirements for the optical components in a high-average-power laser system

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R.; Doss, F.W.; Taylor, J.R.; Wong, J.N.

    1999-07-02

    Optical components needed for high-average-power lasers, such as those developed for Atomic Vapor Laser Isotope Separation (AVLIS), require high levels of performance and reliability. Over the past two decades, optical component requirements for this purpose have been optimized and performance and reliability have been demonstrated. Many of the optical components that are exposed to the high power laser light affect the quality of the beam as it is transported through the system. The specifications for these optics are described including a few parameters not previously reported and some component manufacturing and testing experience. Key words: High-average-power laser, coating efficiency, absorption, optical components

  3. Note: A four-pass acousto-optic modulator system for laser cooling of sodium atoms

    Science.gov (United States)

    Lu, Bo; Wang, Dajun

    2017-07-01

    We present a four-pass acousto-optic modulator (AOM) system for providing the repumping light for laser cooling of sodium atoms. With only one 400 MHz AOM, we achieve a tunable laser frequency shift around 1.6 GHz with total efficiency up to 30%. This setup provides an alternative over conventional methods to generate a sodium repumping light using more expensive high frequency AOMs or electro-optical modulators (EOMs) in the GHz domain. This compact and reliable setup can be easily adapted to other frequencies and may find applications in laser spectroscopy, laser cooling and trapping, and coherent manipulation of atomic quantum states.

  4. Real-time operating system for a multi-laser/multi-detector system

    Science.gov (United States)

    Coles, G.

    1980-01-01

    The laser-one hazard detector system, used on the Rensselaer Mars rover, is reviewed briefly with respect to the hardware subsystems, the operation, and the results obtained. A multidetector scanning system was designed to improve on the original system. Interactive support software was designed and programmed to implement real time control of the rover or platform with the elevation scanning mast. The formats of both the raw data and the post-run data files were selected. In addition, the interface requirements were selected and some initial hardware-software testing was completed.

  5. All-Solid-State Multi-wavelength Laser System from 208 to 830 nm

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shang-Hong; CHEN Guo-Fu; ZHAO Wei; WANG Yi-Shan; YU Lian-Jun

    2001-01-01

    Four-wavelength lasers from the near-infrared to deep-ultraviolet range, 532, 830, 415 and 208nm, have been developed in one all-solid-state laser system. The laser system is pumped by a diode-Q-YLF laser at 532nm,a Ti:sapphire laser, and the nonlinear second-harmonic-generation crystals LBO and BBO are used to generate different wavelengths. Maximum average powers (repetition rate 1 kHz) of 1.1 W at 830nm, 380m W at 415nm and 39mW at 208nm are obtained when the pumping power is 3.6 W. The main characteristics of this system are presented.

  6. Laser ablated micropillar energy directors for ultrasonic welding of microfluidic systems

    DEFF Research Database (Denmark)

    Poulsen, Carl Esben; Kistrup, Kasper; Andersen, Nis Korsgaard

    2016-01-01

    We present a new type of energy director (ED) for ultrasonic welding of microfluidic systems. These micropillar EDs are based on the replication of cone like protrusion structures introduced using a pico-second laser and may therefore be added to any mould surface accessible to a pico-second laser...

  7. Optical systems for high-power laser applications: principles and design aspects

    NARCIS (Netherlands)

    Beckmann, L.H.J.F.; Ehrlichmann, D.

    1995-01-01

    Starting from the optical properties of laser beams, the requirements of optical systems for manipulating laser radiation in industrial applications are derived. The relevant parameters, relations to the diffraction limit and the state-of-the-art design techniques are discussed. The three important

  8. DEVELOPMENT OF A LASER SYSTEM FOR ABSOLUTE ATMOSPHERIC DIFFUSION MEASUREMENT OF A GASEOUS TRACER MATERIAL.

    Science.gov (United States)

    laser development . Successful application of the Rayleigh scattering technique awaits idenficiation of a gas with a Rayleigh scattering cross section near 10 to the (-21)st power cm. squared. The fluorescence approach is feasible at this time with hexafluoroacetone as the tracer gas and a nitrogen laser as the light source. Preliminary system design considerations are presented in an appendix.

  9. Laser ablated micropillar energy directors for ultrasonic welding of microfluidic systems

    DEFF Research Database (Denmark)

    Poulsen, Carl Esben; Kistrup, Kasper; Andersen, Nis Korsgaard

    2016-01-01

    We present a new type of energy director (ED) for ultrasonic welding of microfluidic systems. These micropillar EDs are based on the replication of cone like protrusion structures introduced using a pico-second laser and may therefore be added to any mould surface accessible to a pico-second laser...

  10. Modulation Frequency Multiplexed Tunable Diode Laser Spectroscopy System for Simultaneous CO, CO2 Measurements

    Institute of Scientific and Technical Information of China (English)

    CHEN Dong; LIU Wen-Qing; ZHANG Yu-Jun; LIU Jian-Guo; WEI Qing-Nong; KAN Rui-Feng; WANG Min; CUI Yi-Ben; CHEN Jiu-Ying

    2006-01-01

    @@ A modulation frequency multiplexed dual diode-laser system is developed for simultaneous detection of the two most common fire gas products CO and CO2. Simultaneous detection is achieved by modulating each laser at different frequencies, demodulating the signal by a pair of lock-in amplifiers for each gas.

  11. Design of an Optical System for High Power CO2 Laser Cutting

    DEFF Research Database (Denmark)

    de Lange, D.F.; Meijer, J.; Nielsen, Jakob Skov

    2003-01-01

    The results of a design study for the optical system for cutting with high power CO2 lasers (6 kW and up) will be presented. As transparent materials cannot be used for these power levels, mirrors have been applied. A coaxial cutting gas supply has been designed with a laser beam entrance into th...

  12. Design and observations of satellite laser ranging system for daylight tracking at Shanghai Observatory

    Institute of Scientific and Technical Information of China (English)

    杨福民; 肖炽昆; 陈婉珍; 张忠萍; 谭德同; 龚向东; 陈菊平; 黄力; 章建华

    1999-01-01

    The first satellite laser ranging system for daylight tracking in China was set up at Shanghai Observatory, Chinese Academy of Sciences. Both false alarm probability due to strong background noises and detection probability of the laser returns with single photon level from satellite in daylight for our system are analysed. The system design and performance characteristics of subsystems, adopted techniques and satellite ranging observations are given.

  13. Nondestructive thickness measurement system for multiple layers of paint based on femtosecond fiber laser technologies

    Science.gov (United States)

    Sudo, Masaaki; Takayanagi, Jun; Ohtake, Hideyuki

    2016-11-01

    Because optical fiber-based optical systems are generally robust against external interference, they can be used as reliable systems in industrial applications in various fields. This paper describes fiber lasers generating femtosecond pulses that use optical fibers as gain media and optical paths. Additionally, the nondestructive paint multilayer thickness measurement of automotive parts using terahertz waves generated and detected by femtosecond fiber laser systems was conducted.

  14. Design of a CO2 laser power control system for a Spacelab microgravity experiment

    Science.gov (United States)

    Wenzler, Carl J.; Eichenberg, Dennis J.

    1990-01-01

    The surface tension driven convection experiment (STDCE) is a Space Transportation System flight experiment manifested to fly aboard the USML-1 Spacelab mission. A CO2 laser is used to heat a spot on the surface of silicone oil contained inside a test chamber. Several CO2 laser control systems were evaluated and the selected system will be interfaced with the balance of the experimental hardware to constitute a working engineering model. Descriptions and a discussion of these various design approaches are presented.

  15. Calibration and characterisation with a new laser-based magnetostriction measurement system

    OpenAIRE

    Rafferty, Aran; Bakir, S.; BRABAZON, Dermot; Prescott, Tim

    2009-01-01

    A laser-based magnet measurement system has been developed to measure the magnetostrictive strain of large cylindrical samples. The measurement system incorporates a solenoid capable of generating a maximum magnetic field intensity of 3000 Oe and a laser displacement sensor. For calibration and evaluation purposes, the positive magnetostrictions of two different types of giant magnetostrictive Tb–Dy–Fe-based materials were accessed with this system. A magnetostrictive strain of 622 ppm was ob...

  16. Effect of Er:YAG laser energy on the morphology of enamel/adhesive system interface

    Science.gov (United States)

    Delfino, Carina Sinclér; Souza-Zaroni, Wanessa Christine; Corona, Silmara Aparecida Milori; Pécora, Jesus Djalma; Palma-Dibb, Regina Guenka

    2006-10-01

    The aim of this study was to evaluate in vitro the influence of Er:YAG laser energy variation to cavity preparation on the morphology of enamel/adhesive system interface, using SEM. Eighteen molars were used and the buccal surfaces were flattened without dentine exposure. The specimens were randomly assigned to two groups, according to the adhesive system (conventional total-etching or self-etching), and each group was divided into three subgroups (bur carbide in turbine of high rotation, Er:YAG laser 250 mJ/4 Hz and Er:YAG laser 300 mJ/4 Hz) containing six teeth each. The enamel/adhesive system interface was serially sectioned and prepared for SEM. The Er:YAG laser, in general, produced a more irregular adhesive interface than the control group. For Er:YAG laser 250 mJ there was formation of a more regular hybrid layer with good tag formation, mainly in the total-etching system. However, Er:YAG laser 300 mJ showed a more irregular interface with amorphous enamel and fused areas, for both adhesive systems. It was concluded that cavity preparation with Er:YAG laser influenced on the morphology of enamel/adhesive system interface and the tissual alterations were more evident when the energy was increased.

  17. A simple laser locking system based on a field-programmable gate array

    DEFF Research Database (Denmark)

    Jørgensen, Nils Byg; Birkmose, Danny Matthiesen; Trelborg, Kristian

    2016-01-01

    Frequency stabilization of laser light is crucial in both scientific and industrial applications. Technological developments now allow analog laser stabilization systems to be replaced with digital electronics such as field-programmable gate arrays, which have recently been utilized to develop su...... were performed to characterize the system. The linewidth of the locked laser was measured to be 0.7±0.1 MHz with a settling time of 10 ms. The system can thus fully match laser systems currently in use for atom trapping and cooling applications.......Frequency stabilization of laser light is crucial in both scientific and industrial applications. Technological developments now allow analog laser stabilization systems to be replaced with digital electronics such as field-programmable gate arrays, which have recently been utilized to develop......-integral-derivative controller are programmed on the field-programmable gate array and only minimal additional components are required to frequency stabilize a laser. The locking system is administered from a host-computer which provides comprehensive, long-distance control through a versatile interface. Various measurements...

  18. Colored Noise in First-order-like Phase Transition of a Laser System

    Institute of Scientific and Technical Information of China (English)

    HE Ying; ZHU Shiqun; LING Yinsheng

    2002-01-01

    The decoupling theory is employed to analyze the multiplicative colored noise in a single mode laser system. Steady state intensity distribution function is derived when colored noise is included in the laser system. The first-order-like phase transition driven by multiplicative colored noise is investigated and compared with the case of multiplicative white noise. It is shown that the noise correlation time can affect the parameter plane of the first-order-like phase transition. The steady state intensity distributions in a laser system is changed greatly with noise correlation time τ.

  19. Rapid laser prototyping of valves for microfluidic autonomous systems

    Science.gov (United States)

    Mohammed, M. I.; Abraham, E.; Y Desmulliez, M. P.

    2013-03-01

    Capillary forces in microfluidics provide a simple yet elegant means to direct liquids through flow channel networks. The ability to manipulate the flow in a truly automated manner has proven more problematic. The majority of valves require some form of flow control devices, which are manually, mechanically or electrically driven. Most demonstrated capillary systems have been manufactured by photolithography, which, despite its high precision and repeatability, can be labour intensive, requires a clean room environment and the use of fixed photomasks, limiting thereby the agility of the manufacturing process to readily examine alternative designs. In this paper, we describe a robust and rapid CO2 laser manufacturing process and demonstrate a range of capillary-driven microfluidic valve structures embedded within a microfluidic network. The manufacturing process described allows for advanced control and manipulation of fluids such that flow can be halted, triggered and delayed based on simple geometrical alterations to a given microchannel. The rapid prototyping methodology has been employed with PMMA substrates and a complete device has been created, ready for use, within 2-3 h. We believe that this agile manufacturing process can be applied to produce a range of complex autonomous fluidic platforms and allows subsequent designs to be rapidly explored.

  20. Arterial compliance measurement using a noninvasive laser Doppler measurement system

    Science.gov (United States)

    Hast, Jukka T.; Myllylae, Risto A.; Sorvoja, Hannu; Nissilae, Seppo M.

    2000-11-01

    The aim of this study was to study the elasticity of the arterial wall using a non-invasive laser Doppler measurement system. The elasticity of the arterial wall is described by its compliance factor, which can be determined when both blood pressure and the radial velocity of the arterial wall are known. To measure radical velocity we used a self- mixing interferometer. The compliance factors were measured from six healthy volunteers, whose ages were varied from 21 to 32. Although a single volunteer's compliance factor is presented as an example, this paper treated the volunteers as a group. First, the elastic modulus, which is inversely proportional to the compliance factor, was determined. Then, an exponential curve was fitted into the measured data and a characteristic equation for the elastic modulus of the arterial wall was determined. The elastic modulus was calculated at different pressures and the results were compared to the static incremental modulus of a dog's femoral artery. The results indicate that there is a correlation between human elastic and canine static incremental modulus for blood pressures varying from 60 to 110 mmHg.