WorldWideScience

Sample records for laser amplifier systems

  1. Solid-state disk amplifiers for fusion-laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.E.; Trenholme, J.B.; Linford, G.J.; Yarema, S.M.; Hurley, C.A.

    1981-09-01

    We review the design, performance, and operation of large-aperture (10 to 46 cm) solid-state disk amplifiers for use in laser systems. We present design data, prototype tests, simulations, and projections for conventional cylindrical pump-geometry amplifiers and rectangular pump-geometry disk amplifiers. The design of amplifiers for the Nova laser system is discussed.

  2. Free-electron laser system with Raman amplifier outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Linford, G.J.

    1988-05-03

    A free-electron laser system is described comprising: a free-electron laser pump beam generator producing a high-power optical output beam in a vacuum environement; a Raman amplifier cell located in the path of the output beam from the pump beam generator; means for generating and introducing a Stokes seed beam into the Raman amplifier cell, a pair of gaseous windows through which the output beam enters and leaves the Raman amplifier cell, each window having a stream of gas moving continuously in a direction generally perpendicular to the beam; and a mirror positioned in the path of the output beam from the Raman amplifier, the mirror functioning to reflect and further direct the output beam, but not the unwanted spectral components.

  3. Multi-pass amplifier architecture for high power laser systems

    Science.gov (United States)

    Manes, Kenneth R; Spaeth, Mary L; Erlandson, Alvin C

    2014-04-01

    A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

  4. Ultrashort-pulse laser machining system employing a parametric amplifier

    Science.gov (United States)

    Perry, Michael D.

    2004-04-27

    A method and apparatus are provided for increasing the energy of chirped laser pulses to an output in the range 0.001 to over 10 millijoules at a repetition rate 0.010 to 100 kHz by using a two stage optical parametric amplifier utilizing a bulk nonlinear crystal wherein the pump and signal beam size can be independently adjusted in each stage.

  5. Design optimization of single-main-amplifier KrF laser-fusion systems

    International Nuclear Information System (INIS)

    Harris, D.B.; Pendergrass, J.H.

    1985-01-01

    KrF lasers appear to be a very promising laser fusion driver for commercial applications. The Large Amplifier Module for the Aurora Laser System at Los Alamos is the largest KrF laser in the world and is currently operating at 5 kJ with 10 to 15 kJ eventually expected. The next generation system is anticipated to be a single-main-amplifier system that generates approximately 100 kJ. This paper examines the cost and efficiency tradeoffs for a complete single-main-amplifier KrF laser fusion experimental facility. It has been found that a 7% efficient $310/joule complete laser-fusion system is possible by using large amplifier modules and high optical fluences

  6. Antares laser power amplifier

    International Nuclear Information System (INIS)

    Stine, R.D.; Ross, G.F.; Silvernail, C.

    1979-01-01

    The overall design of the Antares laser power amplifier is discussed. The power amplifier is the last stage of amplification in the 100-kJ Antares laser. In the power amplifier a single, cylindrical, grid-controlle, cold-cathode electron gun is surrounded by 12 large-aperture CO 2 electron-beam sustained laser discharge sectors. Each power amplifier will deliver 18 kJ and the six modules used in Antares will produce the required 100 kJ for delivery to the target. A large-scale interaction between optical, mechanical, and electrical disciplines is required to meet the design objectives. Significant component advances required by the power amplifier design are discussed

  7. Flashlamp excited fluid laser amplified

    International Nuclear Information System (INIS)

    1976-01-01

    The patent describes a laser amplifier with chambers for containing and amplifying an intensifier medium. It serves the need for a large impulse repetition rate and high intensities as required e.g. for laser isotope separation

  8. 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...... 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....

  9. Object-oriented wavefront correction in an asymmetric amplifying high-power laser system

    Science.gov (United States)

    Yang, Ying; Yuan, Qiang; Wang, Deen; Zhang, Xin; Dai, Wanjun; Hu, Dongxia; Xue, Qiao; Zhang, Xiaolu; Zhao, Junpu; Zeng, Fa; Wang, Shenzhen; Zhou, Wei; Zhu, Qihua; Zheng, Wanguo

    2018-05-01

    An object-oriented wavefront control method is proposed aiming for excellent near-field homogenization and far-field distribution in an asymmetric amplifying high-power laser system. By averaging the residual errors of the propagating beam, smaller pinholes could be employed on the spatial filters to improve the beam quality. With this wavefront correction system, the laser performance of the main amplifier system in the Shen Guang-III laser facility has been improved. The residual wavefront aberration at the position of each pinhole is below 2 µm (peak-to-valley). For each pinhole, 95% of the total laser energy is enclosed within a circle whose diameter is no more than six times the diffraction limit. At the output of the main laser system, the near-field modulation and contrast are 1.29% and 7.5%, respectively, and 95% of the 1ω (1053 nm) beam energy is contained within a 39.8 µrad circle (6.81 times the diffraction limit) under a laser fluence of 5.8 J cm-2. The measured 1ω focal spot size and near-field contrast are better than the design values of the Shen Guang-III laser facility.

  10. The Multidisk Diode-Pumped High Power Yb:YAG Laser Amplifier of High-Intensity Laser System with 1 kHz Repetition Rate

    Science.gov (United States)

    Kuptsov, G. V.; Petrov, V. V.; Petrov, V. A.; Laptev, A. V.; Kirpichnikov, A. V.; Pestryakov, E. V.

    2018-04-01

    The source of instabilities in the multidisk diode-pumped high power Yb:YAG laser amplifier with cryogenic closed-loop cooling in the laser amplification channel of the high-intensity laser system with 1 kHz repetition rate was determined. Dissected copper mounts were designed and used to suppress instabilities and to achieve repeatability of the system. The equilibrium temperature dependency of the active elements on average power was measured. The seed laser for the multidisk amplifier was numerically simulated and designed to allow one to increase pulses output energy after the amplifier up to 500 mJ.

  11. Compact fibre-laser-pumped Ho:YLF oscillator–amplifier system

    CSIR Research Space (South Africa)

    Koen, W

    2010-04-01

    Full Text Available of the amplifier crystal L and the pump spot radius wp ( Ω = 2pi · (1 − cosβ), with β = tan−1(wpL )). Calculating the local population in (3) and iterating (6) and (11) along the length of the amplifier crystal, we obtain the extracted photon densities...-pumped tunable Tm: silica- fibre laser. Appl. Phys. B 79, 559 (2004) 6. E. Lippert, S. Nicolas, G. Arisholm, K. Stenersen, G. Rustad, Mid- infrared laser source with high power and beam quality. Appl. Opt. 45, 3839 (2006) 7. S.A. Payne, L.L. Chase, L...

  12. Dielectric waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Pollnau, Markus

    The performance of semiconductor amplifiers and lasers has made them the preferred choice for optical gain on a micro-chip. In the past few years, we have demonstrated that also rare-earth-ion-doped dielectric waveguides show remarkable performance, ranging from a small-signal gain per unit length

  13. Megawatt dye laser oscillator-amplifier system for high resolution spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Drell, P; Chu, S

    1979-03-01

    Peak powers in excess of 4 MW in the visible and 1.3 MW in the uv with linewidths as narrow as 80 MHz are generated with three YAG pumped amplifier stages following a cw dye oscillator. The laser pulses are nearly Fourier transform limited in frequency space and diffraction limited in coordinate space.

  14. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  15. Study of laser pulses propagation through an ultrashort pulse amplifying systems for the development of an Offner temporal stretcher

    International Nuclear Information System (INIS)

    Cordeiro, Thiago da Silva

    2009-01-01

    The study of laser pulses propagation through an ultrashort pulses amplifying system containing dispersive and spectral modifying media was performed. The study emphasis was the development of an ultrashort pulse stretcher to replace the one inside a hybrid Ti:Sapphire/Cr:LiSAF CPA system operating at the Center for Lasers and Applications at IPEN/CNEN-SP. A spherical aberration free Offner stretcher was theoretically studied, aiming to obtain a stretching ratio larger than the one available in our system. The influence of the phase components in the amplified pulse final duration was also studied, and the bandwidth limiting elements of the system in operation were mapped, with the purpose of determining the conditions under which a new stretcher should be implemented. Based on the actual measurements, computing routines were implemented in order to determine the consequences of an ultrashort pulse travelling through a bandwidth limiting component. (author)

  16. Effect of amplifier component maintenance on laser system availability and reliability for the US National Ignition Facility

    International Nuclear Information System (INIS)

    Erlandson, A.C.; Lambert, H.; Zapata, L.E.

    1996-12-01

    We have analyzed the availability and reliability of the flashlamp-pumped, Nd:glass amplifiers that, as a part of a laser now being designed for future experiments, in inertial confinement fusion (ICF), will be used in the National Ignition Facility (NIF). Clearly , in order for large ICF systems such as the NIF to operate effectively as a whole, all components must meet demanding availability and reliability requirements. Accordingly, the NIF amplifiers can achieve high reliability and availability by using reliable parts, and by using a cassette-based maintenance design that allows most key amplifier parts to be 1744 replaced within a few hours. In this way, parts that degrade slowly, as the laser slabs, silver reflectors, and blastshields can be expected to do, based on previous experience, can be replaced either between shots or during scheduled maintenance periods, with no effect on availability or reliability. In contrast, parts that fail rapidly, such as the flashlamps, can and do cause unavailability or unreliability. Our analysis demonstrates that the amplifiers for the NIF will meet availability and reliability goals, respectively, of 99.8% and 99.4%, provided that the 7680 NIF flashlamps in NIF have failure rates of less than, or equal to, those experienced on Nova, a 5000-lamp laser at Lawrence Livermore National Laboratory (LLNL)

  17. A phase stabilized and pulse shaped Ti:Sapphire oscillator-amplifier laser system for the LCLS rf photoinjector

    International Nuclear Information System (INIS)

    Kotseroglou, T.; Alley, R.; Clendenin, J.; Fisher, A.; Frisch, J.

    1998-04-01

    The authors have designed a laser system for the Linac Coherent Light Source rf photoinjector consisting of a Ti:Sapphire oscillator and 2 amplifiers using Chirped Pulse Amplification. The output after tripling will be 0.5 mJ tunable UV pulses at 120 Hz, with wavelength around 260 nm, pulsewidth of 10 ps FWHM and 200 fs rise and fall times. Amplitude stability is expected to be 1% rms in the UV and timing jitter better than 500 fs rms

  18. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  19. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  20. Compact fibre-laser-pumped Ho:YLF oscillator-amplifier system

    CSIR Research Space (South Africa)

    Bollig, C

    2009-06-01

    Full Text Available -amplifier system. 0 5 10 15 20 25 0 1 2 3 4 5 Repetition Rate [kHz] Pu lse En er gy [m J] 0 50 100 150 200 250 Pu lse Le n gt h [ns ] Simulation Results Amp Pulse Energy Osc Pulse Energy Amp Pulse Length Fig. 2 Output energy...

  1. A photodiode amplifier system for pulse-by-pulse intensity measurement of an x-ray free electron laser.

    Science.gov (United States)

    Kudo, Togo; Tono, Kensuke; Yabashi, Makina; Togashi, Tadashi; Sato, Takahiro; Inubushi, Yuichi; Omodani, Motohiko; Kirihara, Yoichi; Matsushita, Tomohiro; Kobayashi, Kazuo; Yamaga, Mitsuhiro; Uchiyama, Sadayuki; Hatsui, Takaki

    2012-04-01

    We have developed a single-shot intensity-measurement system using a silicon positive-intrinsic-negative (PIN) photodiode for x-ray pulses from an x-ray free electron laser. A wide dynamic range (10(3)-10(11) photons/pulse) and long distance signal transmission (>100 m) were required for this measurement system. For this purpose, we developed charge-sensitive and shaping amplifiers, which can process charge pulses with a wide dynamic range and variable durations (ns-μs) and charge levels (pC-μC). Output signals from the amplifiers were transmitted to a data acquisition system through a long cable in the form of a differential signal. The x-ray pulse intensities were calculated from the peak values of the signals by a waveform fitting procedure. This system can measure 10(3)-10(9) photons/pulse of ~10 keV x-rays by direct irradiation of a silicon PIN photodiode, and from 10(7)-10(11) photons/pulse by detecting the x-rays scattered by a diamond film using the silicon PIN photodiode. This system gives a relative accuracy of ~10(-3) with a proper gain setting of the amplifiers for each measurement. Using this system, we succeeded in detecting weak light at the developmental phase of the light source, as well as intense light during lasing of the x-ray free electron laser. © 2012 American Institute of Physics

  2. 885-nm laser diode array pumped ceramic Nd:YAG master oscillator power amplifier system

    Science.gov (United States)

    Yu, Anthony W.; Li, Steven X.; Stephen, Mark A.; Seas, Antonios; Troupaki, Elisavet; Vasilyev, Aleksey; Conley, Heather; Filemyr, Tim; Kirchner, Cynthia; Rosanova, Alberto

    2010-04-01

    The objective of this effort is to develop more reliable, higher efficiency diode pumped Nd:YAG laser systems for space applications by leveraging technology investments from the DoD and other commercial industries. Our goal is to design, build, test and demonstrate the effectiveness of combining 885 nm laser pump diodes and the use of ceramic Nd:YAG for future flight missions. The significant reduction in thermal loading on the gain medium by the use of 885 nm pump lasers will improve system efficiency.

  3. Optical oscillator-amplifier laser configuration

    International Nuclear Information System (INIS)

    McAllister, G.L.

    1975-01-01

    A laser is described that has incorporated therein an oscillator formed by a pair of mirrors, at least one of the mirrors being positioned outside of the envelope. The mirrors are dimensioned and spaced from each other so that the resonator has a relatively low Fresnel number and is operated unstably. The entire surface of one of these mirrors is convex and diffracts a portion of the energy outside of the oscillator region. Also incorporated into the laser is an amplifier region defined by a separate pair of mirrors which receive the energy diffracted from the oscillator region. The second pair of mirrors form an optical system with a high Fresnel number. A filter, modulator or other control for the laser signal may be placed outside the laser envelope in the optical path of the oscillator

  4. Quantum dots for lasers, amplifiers and computing

    International Nuclear Information System (INIS)

    Bimberg, Dieter

    2005-01-01

    For InAs-GaAs based quantum dot lasers emitting at 1300 nm, digital modulation showing an open eye pattern up to 12 Gb s -1 at room temperature is demonstrated, at 10 Gb s -1 the bit error rate is below 10 -12 at -2 dB m receiver power. Cut-off frequencies up to 20 GHz are realised for lasers emitting at 1.1 μm. Passively mode-locked QD lasers generate optical pulses with repetition frequencies between 5 and 50 GHz, with a minimum Fourier limited pulse length of 3 ps. The uncorrelated jitter is below 1 ps. We use here deeply etched narrow ridge waveguide structures which show excellent performance similar to shallow mesa structures, but a circular far field at a ridge width of 1 μm, improving coupling efficiency into fibres. No beam filamentation of the fundamental mode, low a-factors and strongly reduced sensitivity to optical feedback are observed. QD lasers are thus superior to QW lasers for any system or network. Quantum dot semiconductor optical amplifier (QD SOAs) demonstrate gain recovery times of 120-140 fs, 4-7 times faster than bulk/QW SOAs, and a net gain larger than 0.4 dB/(mm*QD-layer) providing us with novel types of booster amplifiers and Mach-Zehnder interferometers. These breakthroughs became possible due to systematic development of self-organized growth technologies

  5. Simulations of longitudinally pumped dye laser amplifier

    International Nuclear Information System (INIS)

    Takehisa, Kiwamu; Takemori, Satoshi

    1995-01-01

    Simulations of a copper laser pumped dye laser amplifier and new designs of the longitudinally pumped dye laser amplifier are presented. The simulations take the consideration of the amplified spontaneous emission (ASE). The new designs utilize a center-hole reflector instead of a dichroic mirror. The simulation results indicate that the poor spatial overlap between the pump beam and the dye beam in the transverse pumping not only reduces the laser output power, but also generates ASE strongly. The results also indicate that the longitudinal pumping is as efficient as the transverse pumping. (author)

  6. Amplified spontaneous emission and thermal management on a high average-power diode-pumped solid-state laser - the Lucia laser system

    International Nuclear Information System (INIS)

    Albach, D.

    2010-01-01

    The development of the laser triggered the birth of numerous fields in both scientific and industrial domains. High intensity laser pulses are a unique tool for light/matter interaction studies and applications. However, current flash-pumped glass-based systems are inherently limited in repetition-rate and efficiency. Development within recent years in the field of semiconductor lasers and gain media drew special attention to a new class of lasers, the so-called Diode Pumped Solid State Laser (DPSSL). DPSSLs are highly efficient lasers and are candidates of choice for compact, high average-power systems required for industrial applications but also as high-power pump sources for ultra-high intense lasers. The work described in this thesis takes place in the context of the 1 kilowatt average-power DPSSL program Lucia, currently under construction at the 'Laboratoire d'Utilisation des Laser Intenses' (LULI) at the Ecole Polytechnique, France. Generation of sub-10 nanosecond long pulses with energies of up to 100 joules at repetition rates of 10 hertz are mainly limited by Amplified Spontaneous Emission (ASE) and thermal effects. These limitations are the central themes of this work. Their impact is discussed within the context of a first Lucia milestone, set around 10 joules. The developed laser system is shown in detail from the oscillator level to the end of the amplification line. A comprehensive discussion of the impact of ASE and thermal effects is completed by related experimental benchmarks. The validated models are used to predict the performances of the laser system, finally resulting in a first activation of the laser system at an energy level of 7 joules in a single-shot regime and 6.6 joules at repetition rates up to 2 hertz. Limitations and further scaling approaches are discussed, followed by an outlook for the further development. (author) [fr

  7. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.; Hwang, In Heon; Kim, Khong Hon; Stock, Larry V.

    1988-01-01

    A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

  8. Model of pulse extraction from a copper laser amplifier

    International Nuclear Information System (INIS)

    Boley, C.D.; Warner, B.E.

    1997-03-01

    A computational model of pulse propagation through a copper laser amplifier has been developed. The model contains a system of 1-D (in the axial direction), time-dependent equations for the laser intensity and amplified spontaneous emission (ASE), coupled to rate equations for the atomic levels. Detailed calculations are presented for a high-power amplifier at Lawrence Livermore National Laboratory. The extracted power agrees with experiment near saturation. At lower input power the calculation overestimates experiment, probably because of increased ASE effects. 6 refs., 6 figs

  9. Amplified spontaneous emissions in a high-gain laser amplifier

    International Nuclear Information System (INIS)

    Osada, Hidenori; Gamo, Hideya.

    1978-01-01

    The gain and line-narrowing of the amplified spontaneous emissions(ASE) in a partially homogeneous high-gain Xe 3.51 μm laser amplifier were studied theoretically and experimentally with emphasis of saturation effect. The unidirectionally travelling ASE was generated by conveniently using optical isolators and used as a broadband radiation source. It has properties of 10 μW/mm 2 in intensity with fluctuation of less than 1% in 5 hours, 43.5 MHz of the linewidth and 1.0 x 10 -3 radians of beam divergence. The measured saturation intensity was 4.85 μW/mm 2 and a small signal gain was 0.1 cm -1 . The theoretical prediction of the line-narrowing shows reasonablly good agreement with the measured one. (author)

  10. Dual-wavelength high-power diode laser system based on an external-cavity tapered amplifier with tunable frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2012-01-01

    knowledge, this is the broadest tuning range of the frequency difference from a dual-wavelength diode laser system. The spectrum, output power, and beam quality of the diode laser system are characterized. The power stability of each wavelength is measured, and the power fluctuations of the two wavelengths......A dual-wavelength high-power semiconductor laser system based on a tapered amplifier with double-Littrow external cavity is demonstrated around 800 nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 10.0 THz. To our...

  11. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.; Hwang, In Heon

    1990-01-01

    The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

  12. X-ray laser '' oscillator-amplifier'' experiments

    International Nuclear Information System (INIS)

    Shimkaveg, G.M.; Carter, M.R.; Young, B.K.F.; Walling, R.S.; Osterheld, A.L.; Trebes, J.E.; London, R.A.; Ratowsky, R.P.; Stewart, R.E.; Craxton, R.S.

    1993-01-01

    We present results from experiments directed toward increasing the degree of transverse coherence in x-ray laser beams. We have concentrated on the neon-like yttrium (Z=39) collisionally-pumped x-ray laser as the test system for these studies because of its unique combination of brightness, monochromaticity, and high-reflectivity optics availability. Attempts at improving laser performance using proximate feedback optics failed. Modest success has been found to date in ''double foil'' experiments, involving two x-ray lasers spatially separated by 29 cm and shot sequentially in an ''oscillator-amplifier'' configuration

  13. Large area electron beam pumped krypton fluoride laser amplifier

    International Nuclear Information System (INIS)

    Sethian, J.D.; Obenschain, S.P.; Gerber, K.A.; Pawley, C.J.; Serlin, V.; Sullivan, C.A.; Webster, W.; Deniz, A.V.; Lehecka, T.; McGeoch, M.W.; Altes, R.A.; Corcoran, P.A.; Smith, I.D.; Barr, O.C.

    1997-01-01

    Nike is a recently completed multi-kilojoule krypton fluoride (KrF) laser that has been built to study the physics of direct drive inertial confinement fusion. This paper describes in detail both the pulsed power and optical performance of the largest amplifier in the Nike laser, the 60 cm amplifier. This is a double pass, double sided, electron beam-pumped system that amplifies the laser beam from an input of 50 J to an output of up to 5 kJ. It has an optical aperture of 60 cm x 60 cm and a gain length of 200 cm. The two electron beams are 60 cm high x 200 cm wide, have a voltage of 640 kV, a current of 540 kA, and a flat top power pulse duration of 250 ns. A 2 kG magnetic field is used to guide the beams and prevent self-pinching. Each electron beam is produced by its own Marx/pulse forming line system. The amplifier has been fully integrated into the Nike system and is used on a daily basis for laser-target experiments. copyright 1997 American Institute of Physics

  14. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.

    1987-01-01

    This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

  15. Pulsed hybrid dual wavelength Y-branch-DFB laser-tapered amplifier system suitable for water vapor detection at 965 nm with 16 W peak power

    Science.gov (United States)

    Vu, Thi N.; Klehr, Andreas; Sumpf, Bernd; Hoffmann, Thomas; Liero, Armin; Tränkle, Günther

    2016-03-01

    A master oscillator power amplifier system emitting alternatingly at two neighbored wavelengths around 965 nm is presented. As master oscillator (MO) a Y-branch DFB-laser is used. The two branches, which can be individually controlled, deliver the two wavelengths needed for a differential absorption measurement of water vapor. Adjusting the current through the DFB sections, the wavelength can be adjusted with respect to the targeted either "on" or "off" resonance, respectively wavelength λon or wavelength λoff. The emission of this laser is amplified in a tapered amplifier (TA). The ridge waveguide section of the TA acts as optical gate to generate short pulses with duration of 8 ns at a repetition rate of 25 kHz, the flared section is used for further amplification to reach peak powers up to 16 W suitable for micro-LIDAR (Light Detection and Ranging). The necessary pulse current supply user a GaN-transistor based driver electronics placed close to the power amplifier (PA). The spectral properties of the emission of the MO are preserved by the PA. A spectral line width smaller than 10 pm and a side mode suppression ratio (SMSR) of 37 dB are measured. These values meet the demands for water vapor absorption measurements under atmospheric conditions.

  16. Amplified spontaneous emission in solar-pumped iodine laser

    Science.gov (United States)

    Cho, Yong S.; Hwang, In H.; Han, Kwang S.; Lee, Ja H.

    1992-01-01

    The amplified spontaneous emission (ASE) from a long pulse, solar-simulating radiation pumped iodine laser amplifier is studied. The ASE threshold pump intensity is almost proportional to the inverse of the laser gain length when the gas pressure is constant in the laser tube.

  17. A high power gain switched diode laser oscillator and amplifier for the CEBAF polarized electron injector

    International Nuclear Information System (INIS)

    Poelker, M.; Hansknecht, J.

    1996-01-01

    The photocathode in the polarized electron source at Jefferson Lab is illuminated with pulsed laser light from a gain switched diode laser and diode optical amplifier. Laser pulse repetition rates up to 2,000 MHz, optical pulsewidths between 31 and 123 ps, and average power > 100 mW are demonstrated. The laser system is highly reliable and completely remotely controlled

  18. Pulsed hydrogen fluoride laser oscillator-amplifier experiments

    International Nuclear Information System (INIS)

    Schott, G.L.

    1975-01-01

    Pulsed HF chemical laser oscillator energies were scaled from millijoules to several kilojoules over the period 1970-1974, reaching approximately 10 J with SF 6 and transverse discharges, and using electron-beam initiation and elemental F 2 above 1000J. This demonstrated scalability to large energy with acceptable electrical efficiency is only one prerequisite for application of this gas laser in fusion; equally important matters are achievement of focusable, approximately 1 ns pulses, couplable to light-element targets, all from an affordable system. Exploratory MOPA experiments are reported which address control of HF laser beam focusability and pulse duration, using SF 6 -based experimental oscillator--amplifier sequences and Pockels' cell switching. Simultaneous multiline lasing with 2.6 less than or equal to lambda less than or equal to 3.1 μm and high specific gain and energy density are particularly important factors encountered with HF, where amplifier pumping and lasing occur in a substantially cw temporal relationship, even in less than 100 ns bursts. Time-resolved SF 6 --HI oscillator spectra contain 27 simultaneous lines from six vibrational bands. An apertured, SF 6 -hydrocarbon pin-discharge oscillator generates approximately 10 mJ of TEM 00 radiation, which is amplified to approximately 1 J in approximately 150 ns by a TEA amplifier and p []opagated tens of meters. A three-stage system coupling these elements through an approximately 1 ns electrooptic gate to a greater than 10 J, e-beam energized amplifier is under development. (auth)

  19. ICESat-2 laser Nd:YVO4 amplifier

    Science.gov (United States)

    Sawruk, Nicholas W.; Burns, Patrick M.; Edwards, Ryan E.; Litvinovitch, Viatcheslav; Martin, Nigel; Witt, Greg; Fakhoury, Elias; Iskander, John; Pronko, Mark S.; Troupaki, Elisavet; Bay, Michael M.; He, Charles C.; Wang, Liqin L.; Cavanaugh, John F.; Farrokh, Babak; Salem, Jonathan A.; Baker, Eric

    2018-02-01

    We report on the cause and corrective actions of three amplifier crystal fractures in the space-qualified laser systems used in NASA Goddard Space Flight Center's (GSFC) Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2). The ICESat-2 lasers each contain three end-pumped Nd:YVOO4 amplifier stages. The crystals are clamped between two gold plated copper heat spreaders with an indium foil thermal interface material, and the crystal fractures occurred after multiple years of storage and over a year of operational run-time. The primary contributors are high compressive loading of the NdYVO4 crystals at the beginning of life, a time dependent crystal stress caused by an intermetallic reaction of the gold plating and indium, and slow crack growth resulting in a reduction in crystal strength over time. An updated crystal mounting scheme was designed, analyzed, fabricated and tested. Thee fracture slab failure analysis, finite-element modeling and corrective actions are presented.

  20. Rippled beam free electron laser amplifier

    Science.gov (United States)

    Carlsten, Bruce E.

    1999-01-01

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  1. Recent advances in long wavelength quantum dot lasers and amplifiers

    NARCIS (Netherlands)

    Nötzel, R.; Bente, E.A.J.M.; Smit, M.K.; Dorren, H.J.S.

    2009-01-01

    We demonstrate 1.55-µm InAs/InGaAsP/InP (100) quantum dot (QD) shallow and deep etched Fabry-Pérot and ring lasers, micro-ring lasers, mode-locked lasers, Butt-joint integrated lasers, polarization control of gain, and wavelength conversion in QD amplifiers.

  2. Shiva laser system performance

    International Nuclear Information System (INIS)

    Glaze, J.; Godwin, R.O.; Holzrichter, J.F.

    1978-01-01

    On November 18, 1977, after four years of experimentation, innovation, and construction, the Shiva High Energy Laser facility produced 10.2 kJ of focusable laser energy delivered in a 0.95 ns pulse. The Shiva laser, with its computer control system and delta amplifiers, demonstrated its versatility on May 18, 1978, when the first 20-beam target shot with delta amplifiers focused 26 TW on a target and produced a yield of 7.5 x 10 9 neutrons

  3. Tapered amplifier laser with frequency-shifted feedback

    Directory of Open Access Journals (Sweden)

    A. Bayerle, S. Tzanova, P. Vlaar, B. Pasquiou, F. Schreck

    2016-10-01

    Full Text Available We present a frequency-shifted feedback (FSF laser based on a tapered amplifier. The laser operates as a coherent broadband source with up to 370GHz spectral width and 2.3us coherence time. If the FSF laser is seeded by a continuous-wave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. The laser has an output power of 280mW and a center wavelength of 780nm. The ease and flexibility of use of tapered amplifiers makes our FSF laser attractive for a wide range of applications, especially in metrology.

  4. The Nike electron-beam-pumped KrF laser amplifiers

    International Nuclear Information System (INIS)

    Sethian, J.D.; Pawley, C.J.; Obenschain, S.P.

    1997-01-01

    Nike is a recently completed multikilojoule krypton-fluoride (KrF) laser that has been built to study the physics of direct-drive inertial confinement fusion. The two final amplifiers of the Nike laser are both electron-beam-pumped systems. This paper describes these two amplifiers, with an emphasis on the pulsed power. The smaller of the two has a 20 x 20 cm aperture, and produces an output laser beam energy in excess of 100 J. This 20 cm Amplifier uses a single 12 kJ Marx generator to inject two 300 kV, 75 kA, 140 ns flat-top electron beams into opposite sides of the laser cell. The larger amplifier in Nike has a 60 x 60 cm aperture, and amplifies the laser beam up to 5 kJ. This 60 cm amplifier has two independent electron beam systems. Each system has a 170 kJ Marx generator that produces a 670 kV, 540 kA, 240 ns flat-top electron beam. Both amplifiers are complete, fully integrated into the laser, meet the Nike system requirements, and are used routinely for laser-target experiments

  5. Numerical analysis of amplification of picosecond pulses in a THL-100 laser system with an increase in the pump energy of the XeF(C – A) amplifier

    Science.gov (United States)

    Yastremskii, A. G.; Ivanov, N. G.; Losev, V. F.

    2018-03-01

    Energy characteristics of laser radiation with a pulse width of 50 ps at an elevated pump energy of the XeF(C – A) amplifier of a hybrid THL-100 laser system are analysed numerically. The dynamics of the change in the energy and maximum intensity of laser radiation with an increase in the pump energy of the XeF(C – A) amplifier from 270 to 400 J is investigated. The results of studying the influence of the input beam divergence on the energy characteristics of the output beam are presented. It is shown that, for the existing system of mirrors, an increase in the pump energy to 400 J leads to an increase in the output energy from 3.2 to 5.5 J at a maximum radiation intensity of 57 GW cm-2. A system of amplifier mirrors with 27 laser beam passes and enlarged divergence angle of the amplified beam is considered. Theoretically, the proposed system of mirrors allows one to increase the laser pulse energy to 7.5 J at a maximum intensity of no more than 14.8 GW cm-2. The calculated efficiency of the conversion of the pump energy absorbed in the amplifier gas chamber into the lasing energy exceeds 3% in this regime.

  6. Design of a high-gain laser diode-array pumped Nd:YAG alternating precessive slab amplifier (APS amplifier)

    Science.gov (United States)

    Coyle, D. B.

    1991-01-01

    In the design of space-qualifiable laser systems for ranging and altimetry, such as NASA's Geodynamic Laser Ranging System (GLRS), the transmitter must be kept small, powerful yet efficient, and must consist of as few components as possible. A novel preamplifier design is examined which requires no external beam steering optics, yielding a compact component with simple alignment procedures. The gains achieved are comparable to multipass zigzag amplifiers using two or more sets of external optics for extra passes through the amplifying medium.

  7. Automatic alignment of double optical paths in excimer laser amplifier

    Science.gov (United States)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  8. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  9. Optical Parametric Chirped-Pulse Amplifier as the Front End for the OMEGA EP Laser Chain

    International Nuclear Information System (INIS)

    Bagnoud, V.; Begishev, I.A.; Guardalben, M.J.; Keegan, J.; Puth, J.; Waxer, L.J.; Zuegel, J.D.

    2004-01-01

    A 145-mJ optical parametric amplifier has been developed as a front-end source prototype for the OEMGA EP laser chain. The system definition is presented together with experimental results that show 30% conversion efficiency

  10. Injection seeded, diode pumped regenerative ring Nd:YAG amplifier for spaceborne laser ranging technology development

    Science.gov (United States)

    Coyle, D. Barry; Kay, Richard B.; Degnan, John J.; Krebs, Danny J.; Seery, Bernard D.

    1992-01-01

    A small, all solid state, regenerative ring amplifier designed as a prototype for space application is discussed. Novel features include dual side pumping of the Nd:YAG crystal and a triangular ring cavity design which minimizes the number of optical components and losses. The amplifier is relatively small (3 ns round trip time) even though standard optical elements are employed. The ring regeneratively amplifies a 100 ps single pulse by approximately 10(exp 5) at a repetition rate of 10 to 100 Hz. The amplifier is designed to be injection seeded with a pulsed, 100 ps laser diode at 1.06 microns, but another Nd:YAG laser system supplying higher pulse energies was employed for laboratory experiment. This system is a prototype laser oscillator for the Geoscience Laser Ranging System (GLRS) platform. Results on measurements of beam quality, astigmatism, and gain are given.

  11. Multiple excitation regenerative amplifier inertial confinement system

    International Nuclear Information System (INIS)

    George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

    1980-01-01

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation

  12. LED-pumped Alexandrite laser oscillator and amplifier

    Science.gov (United States)

    Pichon, Pierre; Blanchot, Jean-Philippe; Balembois, François; Druon, Frédéric; Georges, Patrick

    2018-02-01

    In this paper, we report the first LED-pumped transition-metal-doped laser oscillator and amplifier based on an alexandrite crystal (Cr3+:BeAl2O4). A Ce:YAG luminescent concentrator illuminated by blue LEDs is used to reach higher pump powers than with LEDs alone. The luminescent 200-mm-long-composit luminescent concentrator involving 2240 LEDs can delivers up to 268 mJ for a peak irradiance of 8.5 kW/cm2. In oscillator configuration, an LED-pumped alexandrite laser delivering an energy of 2.9 mJ at 748 nm in free running operation is demonstrated. In the cavity, we measured a double pass small signal gain of 1.28, in good agreement with numerical simulations. As amplifier, the system demonstrated to boost a CW Ti:sapphire laser by a factor of 4 at 750 nm in 8 passes with a large tuning range from 710 nm to 800 nm.

  13. KrF laser amplifier with phase-conjugate Brillouin retroreflectors.

    Science.gov (United States)

    Gower, M C

    1982-09-01

    We have demonstrated the use of phase-conjugate stimulated Brillouin scattering mirrors to produce high-quality, short-pulse KrF laser beams from angular multiplexed and regenerative amplifiers. The mirror was also shown to isolate systems optically from amplifier spontaneous emission. Automatic alignment of targets using this mirror as a retroreflector was also demonstrated.

  14. SPS RF System Amplifier plant

    CERN Multimedia

    1977-01-01

    The picture shows a 2 MW, 200 MHz amplifier plant with feeder lines. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  15. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture

  16. Distributed feedback laser amplifiers combining the functions of amplifiers and channel filters

    DEFF Research Database (Denmark)

    Wang, Z.; Durhuus, T.; Mikkelsen, Benny

    1994-01-01

    A dynamic model for distributed feedback amplifiers, including the mode coupled equations and the carrier rate equation, is established. The presented mode coupled equations have taken into account the interaction between fast changing optical signal and the waveguide with corrugations. By showin...... the possibility of amplifying 100 ps pulses without pulse broadening, we anticipate that a distributed feedback amplifier can be used as a combined amplifier and channel filter in high bit rate transmission systems....

  17. Optimum design of a multi-stage dye-laser amplifier pumped with Cu-vapor lasers

    International Nuclear Information System (INIS)

    Maeda, Mitsuo; Uchiumi, Michihiro

    1990-01-01

    A numerical simulation code, based on the one-dimensional photon transport equation, was developed and analyzed to evaluate the performances of Rhodamine 6G dye laser amplifiers pumped with Cu-vapor lasers. The upper singlet-state absorption played an important role to determine the efficiency. The simulation code was applied to optimize a multi-stage amplifier system with a pulsed or a CW dye-laser oscillator. The analytical results gave a useful guideline to design a high-power pulsed dye-laser system for atomic uranium enrichment. (author)

  18. Overview of solid state lasers with applications as LIDAR transmitters and optical image amplifiers

    International Nuclear Information System (INIS)

    Powell, R.C.; Basiev, T.T.; Zverev, P.G.

    2000-01-01

    Full text: This talk will review the current status of solid state lasers. Then a specific class of solid state lasers, Raman lasers, will be discussed as a specific example of new technology development. The spectroscopic properties of the materials are used in these lasers is presented and the use of these materials in shared-, coupled-, and external-resonator laser systems is described. System design parameters affecting efficiency, beam quality, and temporal pulse width are discussed. Examples will be presented of the use of these lasers for transmitters in atmospheric and marine imaging light detection and ranging (LIDAR) systems and in optical amplifiers

  19. Rare-Earth Doped Photonic Crystal Fibre Lasers and Amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.

    2005-01-01

    In this thesis, a theoretical and numerical study of the use of rare-earthdoped photonic crystal fibres as optical amplifiers and lasers, has been performed. Photonic crystal fibres or microstructured optical fibres is a new kind of optical fibre in which the cladding region typically consist....... Their novel properties allow for design of optical fibre amplifiers and fibre lasers with superior performance, compared to solutions based on conventional fibres. The primary applications considered are high efficiency fibre amplifiers based on index guiding photonic crystal fibres, and cladding pumped....... The thesis also presents the basic properties of optical amplification, and describes the numerical model developed to model the behaviour of lasers and amplifiers based on photonic crystal fibres. The developed numerical tools are then used to investigate specific applications of photonic crystal fibres...

  20. Pre-Amplifier Module for Laser Inertial Confinement Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Heebner, J E; Bowers, M W

    2008-02-06

    The Pre-Amplifier Modules (PAMs) are the heart of the National Ignition Facility (NIF), providing most of the energy gain for the most energetic laser in the world. Upon completion, NIF will be the only laboratory in which scientists can examine the fusion processes that occur inside stars, supernovae, and exploding nuclear weapons and that may someday serve as a virtually inexhaustible energy source for electricity. Consider that in a fusion power plant 50 cups of water could provide the energy comparable to 2 tons of coal. Of paramount importance for achieving laser-driven fusion ignition with the least energy input is the synchronous and symmetric compression of the target fuel--a condition known as laser power balance. NIF's 48 PAMs thus must provide energy gain in an exquisitely stable and consistent manner. While building one module that meets performance requirements is challenging enough, our design has already enabled the construction and fielding of 48 PAMs that are stable, uniform, and interchangeable. PAM systems are being tested at the University of Rochester's Laboratory for Laser Energetics, and the Atomic Weapons Enterprise of Great Britain has purchased the PAM power system.

  1. Trial manufacture of inside ellipse mirror for laser amplifier

    International Nuclear Information System (INIS)

    Kodama, Kenzo; Numajiri, Fumio; Kikuta, Yozo; Takasawa, Minoru; Oohira, Susumu; Nagaoka, Isao

    1984-01-01

    Inside ellipse mirrors have been trially manufactured for high power glass laser amplifiers. Their cutting process, machining, surface roughness, usage of cutting tools, materials, and processing process are given. Trial manufacture of supplementary devices for adjusting the direction of laser beam axis is also given. (author)

  2. The Modulation Response of a Semiconductor Laser Amplifier

    DEFF Research Database (Denmark)

    Mørk, Jesper; Mecozzi, Antonio; Eisenstein, Gadi

    1999-01-01

    We present a theoretical analysis of the modulation response of a semiconductor laser amplifier. We find a resonance behavior similar to the well-known relaxation oscillation resonance found in semiconductor lasers, but of a different physical origin. The role of the waveguide (scattering) loss i...

  3. Design of a high-gain laser diode-array pumped Nd:YAG Alternating Precessive Slab Amplifier (APS-Amplifier)

    Science.gov (United States)

    Coyle, D. Barry

    1991-01-01

    In the design of space qualifiable laser systems for ranging and altimetry, such as NASA's Geodynamic Laser Ranging System (GLRS), the transmitter must be kept small, powerful yet efficient, and must consist of as few components as possible. A novel preamplifier design is examined which requires no external beam steering optics, yielding a compact component with simple alignment procedures. The gains achieved are comparable to multipass zigzag amplifiers using two or more sets of external optics for extra passes through the amplifying medium.

  4. Power Scaling of Laser Oscillators and Amplifiers Based on Nd:YVO4

    OpenAIRE

    Yarrow, Michael James

    2006-01-01

    This thesis presents a strategy for power and brightness scaling in diode-end-pumped, master-oscillator-power-amplifier laser systems, based on Nd:YVOIssues relating to further power and brightness scaling are discussed as well as the potential applications of these laser sources as pump sources for frequency conversion in optical parametric devices.

  5. Detection of weak optical signals with a laser amplifier

    International Nuclear Information System (INIS)

    Kozlovskii, A. V.

    2006-01-01

    Detection of weak and extremely weak light signals amplified by linear and four-wave mixing laser amplifiers is analyzed. Photoelectron distributions are found for different input photon statistics over a wide range of gain. Signal-to-noise ratios are calculated and analyzed for preamplification schemes using linear and four-wave mixing amplifiers. Calculations show that the high signal-to-noise ratio (much higher than unity), ensuring reliable detection of weak input signals, can be attained only with a four-wave mixing preamplification scheme. Qualitative dependence of the signal-to-noise ratio on the quantum statistical properties of both signal and idler waves is demonstrated

  6. Performance of a 200-J KrF laser amplifier for laser fusion research

    International Nuclear Information System (INIS)

    Owadano, Y.; Okuda, I.; Tanimoto, M.; Kasai, T.; Matsumoto, Y.; Yaoita, A.; Nemoto, F.; Komeiji, S.; Yano, M.

    1986-01-01

    An e-beam-pumped KrF laser has been developed as a middle-stage amplifier of a 1-kJ system for laser fusion research. The laser consists of one Marx generator (1MV, 11kJ), two PFLs (4.6 Ω, 100ns) with laser triggered output switches, two e-beam diodes (10 X 60 cm/sup 2/), and a laser cell (20- X 20- X 60-cm/sup 3/ active volume). Two e-beams are injected into the cell through carbon-sprayed Kapton anode and pressure foils. Up to now, a 120-J (70-ns) laser pulse has been generated with a 90% output coupling flat-flat resonator at 80% voltage operation. Overall efficiency is 1.5% in this case. A series of experiments has been performed with the laser to measure gain characteristics of a Kr-rich mixture, which is predicted to be more efficient than a normal Ar mixture in a high-laser-intensity region (>10 MW cm/sup -2/). An injection-locked oscillator mode was used to obtain a well-defined high-intensity laser beam, and a saturated intracavity intensity was measured

  7. Analysis and evaluation of zig-zag slab laser amplifier with optical diamond geometry

    International Nuclear Information System (INIS)

    Matsumoto, Osamu; Yasuhara, Ryo; Kanabe, Tadashi

    2007-01-01

    In this paper, we describe the development of a high-average-power solid-state laser system and the derivation of equations for the amplification of a laser beam. This laser system is capable of generating an output energy of 10J per pulse at a wavelength of 1,053nm in a 10 Hz operation for scientific and industrial applications. The main amplifier of our system is a laser-diode-pumped solid-state amplifier. A water-cooled Nd:glass slab is pumped with two 803 nm AlGaAs laser-diode modules. The laser beam propagates through zig-zag optical paths four times and is amplified. To estimate laser output energy, we have derived and evaluated equations for the amplification of the laser beam, and designed and constructed a laser system based on the calculated results. Experimental results reveal an output energy of 10.6 J at 1 Hz, which closely fits the results calculated using the derived equations. (author)

  8. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    Science.gov (United States)

    Nascimento, Jehan F.; Silva, Marcionilo J.; Coêlho, Isnaldo J. S.; Cipriano, Eliel; Martins-Filho, Joaquim F.

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations. PMID:22737017

  9. Power neodymium-glass amplifier of a repetitively pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, Aleksandr V; Gaganov, V E; Garanin, Sergey G; Zhidkov, N V; Krotov, V A; Martynenko, S P; Pozdnyakov, E V; Solomatin, I I [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

    2011-11-30

    A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsed laser. An amplifier unit with an aperture of 20 Multiplication-Sign 25 mm and a {approx}40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 {mu}s. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass {approx}3.2, the linear gain {approx}0.031 cm{sup -1} with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 - 0.21 J cm{sup -3}. The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4{lambda} ({lambda} = 0.63 {mu}m is the probing radiation wavelength).

  10. Power neodymium-glass amplifier of a repetitively pulsed laser

    International Nuclear Information System (INIS)

    Vinogradov, Aleksandr V; Gaganov, V E; Garanin, Sergey G; Zhidkov, N V; Krotov, V A; Martynenko, S P; Pozdnyakov, E V; Solomatin, I I

    2011-01-01

    A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsed laser. An amplifier unit with an aperture of 20 × 25 mm and a ∼40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 μs. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass ∼3.2, the linear gain ∼0.031 cm -1 with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 - 0.21 J cm -3 . The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4λ (λ = 0.63 μm is the probing radiation wavelength).

  11. Free electron laser amplifier driven by an induction linac

    International Nuclear Information System (INIS)

    Neil, V.K.

    1986-01-01

    This paper discusses the use of a free-electron laser amplifier as a means of converting the kinetic energy of an electron beam into coherent radiation. In particular, the use of an induction linear accelerator is discussed. The motion of the elections in the tapered and untapered wiggler magnets is discussed as well as the beam emittance, and the radiation fields involved

  12. ytterbium- & erbium-doped silica for planar waveguide lasers & amplifiers

    DEFF Research Database (Denmark)

    Dyndgaard, Morten Glarborg

    2001-01-01

    The purpose of this work was to demonstrate ytterbium doped planar components and investigate the possibilities of making erbium/ytterbium codoped planar waveguides in germano-silica glass. Furthermore, tools for modelling lasers and erbium/ytterbium doped amplifiers. The planar waveguides were...

  13. A system for biasing a differential amplifier

    International Nuclear Information System (INIS)

    Barbier, Daniel; Ittel, J.M.; Poujois, Robert

    1975-01-01

    This invention concerns a system for biasing a differential amplifier. It particularly applies to the integrated differential amplifiers designed with MOS field effect transistors. Variations in the technological parameters may well cause the amplifying transistors to work outside their usual operational area, in other words outside the linear part of the transfer characteristic. To ensure that these transistors function correctly, it is necessary that the value of the voltage difference at the output be equally null. To do this and to centre on the so called 'rest' point of the amplifier transfer charateristic, the condition will be set that the output potentials of each amplifier transistor should have a zero value or a constant value as sum. With this in view, the bias on the source (generally a transistor powered by its grid bias voltage) supplying current to the two amplifying transistors fitted in parallel, is permanently adjusted in a suitable manner [fr

  14. Coherent combining of high brightness tapered lasers in master oscillator power amplifier configuration

    Science.gov (United States)

    Albrodt, P.; Hanna, M.; Moron, F.; Decker, J.; Winterfeldt, M.; Blume, G.; Erbert, G.; Crump, P.; Georges, P.; Lucas-Leclin, G.

    2018-02-01

    Improved diode laser beam combining techniques are in strong demand for applications in material processing. Coherent beam combining (CBC) is the only combining approach that has the potential to maintain or even improve all laser properties, and thus has high potential for future systems. As part of our ongoing studies into CBC of diode lasers, we present recent progress in the coherent superposition of high-power single-pass tapered laser amplifiers. The amplifiers are seeded by a DFB laser at λ = 976 nm, where the seed is injected into a laterally single-mode ridge-waveguide input section. The phase pistons on each beam are actively controlled by varying the current in the ridge section of each amplifier, using a sequential hill-climbing algorithm, resulting in a combined beam with power fluctuations of below 1%. The currents into the tapered sections of the amplifiers are separately controlled, and remain constant. In contrast to our previous studies, we favour a limited number of individual high-power amplifiers, in order to preserve a high extracted power per emitter in a simple, low-loss coupling arrangement. Specifically, a multi-arm interferometer architecture with only three devices is used, constructed using 6 mm-long tapered amplifiers, mounted junction up on C-mounts, to allow separate contact to single mode and amplifier sections. A maximum coherently combined power of 12.9 W is demonstrated in a nearly diffraction-limited beam, corresponding to a 65% combining efficiency, with power mainly limited by the intrinsic beam quality of the amplifiers. Further increased combined power is currently sought.

  15. Off-axis multipass amplifier as a large aperture driver stage for fusion lasers

    International Nuclear Information System (INIS)

    Murray, J.E.; Downs, D.C.; Junt, J.T.; Hermes, G.L.; Warren, W.E.

    1981-01-01

    A multipass amplifier configuration is described which has potential as a large aperture, high gain driver stage for fusion laser systems. We avoid the present limitations of large aperture switches by using an off-angle geometry that does not require an optical switch. The saturated gain characteristics of this multipass amplifier are optimized numerically. Three potential problems are investigated experimentally, self-lasing, output beam quality, and amplified spontaneous emission output. The results indicate comparable cost for comparable performance to a linear chain, with some operational advantage for the multipass driver stage

  16. Dual-range linearized transimpedance amplifier system

    Science.gov (United States)

    Wessendorf, Kurt O.

    2010-11-02

    A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).

  17. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    The invention broadly involves a method and means for generating a traveling wave laser pulse and is basically analogous to a single pass light amplifier system. However, the invention provides a traveling wave laser pulse of almost unlimited energy content, wherein a gain medium is pumped in a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  18. Microdrilling of metals with an inexpensive and compact ultra-short-pulse fiber amplified microchip laser

    Energy Technology Data Exchange (ETDEWEB)

    Ancona, A. [Friedrich-Schiller-Universitaet Jena, Institut fuer Angewandte Physik, Jena (Germany); CNR-INFM Regional Laboratory ' LIT3' , Dipartimento Interuniversitario di Fisica, Bari (Italy); Nodop, D.; Limpert, J.; Nolte, S. [Friedrich-Schiller-Universitaet Jena, Institut fuer Angewandte Physik, Jena (Germany); Tuennermann, A. [Friedrich-Schiller-Universitaet Jena, Institut fuer Angewandte Physik, Jena (Germany); Fraunhofer Institute for Applied Optics and Precision Engineering (IOF), Jena (Germany)

    2009-01-15

    We have investigated the ultra-fast microdrilling of metals using a compact and cheap fiber amplified passively Q-switched microchip laser. This laser system delivers 100-ps pulses with repetition rates higher than 100 kHz and pulse energies up to 80 {mu}J. The ablation process has been studied on metals with quite different thermal properties (copper, carbon steel and stainless steel). The dependence of the ablation depth per pulse on the pulse energy follows the same logarithmic scaling laws governing laser ablation with sub-picosecond pulses. Structures ablated with 100-ps laser pulses are accompanied only by a thin layer of melted material. Despite this, results with a high level of precision are obtained when using the laser trepanning technique. This simple and affordable laser system could be a valid alternative to nanosecond laser sources for micromachining applications. (orig.)

  19. Linewidth broadening in a distributed feedback laser integrated with a semiconductor optical amplifier

    DEFF Research Database (Denmark)

    Champagne, A.; Camel, J.; Maciejko, R.

    2002-01-01

    The problem of the linewidth degradation in systems using distributed-feedback lasers together with strained-layer multi-quantum-well semiconductor optical amplifiers (SOAs) is examined. A modified expression for the linewidth in the case of antireflection-coated SOA output facets is derived and ...

  20. Spectral characteristics of DFB lasers in presence of a semiconductor optical amplifier

    DEFF Research Database (Denmark)

    Champagne, A.; Camel, J.; Maciejko, R.

    2002-01-01

    The problem of the linewidth degradation in systems using distributed-feedback lasers together with strained-layer multi-quantum-well semiconductor optical amplifiers (SOAs) is examined. A numerical model combining finite element calculations in the transverse x - y plane and a longitudinal model...

  1. Regime for a Self-ionizing Raman Laser Amplifier

    International Nuclear Information System (INIS)

    Clark, D.S.; Fisch, N.J.

    2001-01-01

    Backward Raman amplification and compression at high power might occur if a long pumping laser pulse is passed through a plasma to interact resonantly with a counter-propagating short seed pulse [V.M. Malkin, et al., Phys. Rev. Lett. 82 (1999) 4448-4451]. One critical issue, however, is that the pump may be unacceptably depleted due to spontaneous Raman backscatter from intrinsic fluctuations in the amplifying plasma medium prior to its useful interaction with the seed. Premature backscatter may be avoided, however, by employing a gaseous medium with pump intensities too low to ionize the medium, and using the intense seed to produce the plasma by rapid photoionization as it is being amplified [V.M. Malkin, et al., Phys. Plasmas (2001)]. In addition to allowing that only rather low power pumps be used, photoionization introduces a damping of the short pulse which must be overcome by the Raman growth rate for net amplification to occur. The parameter space of gas densities, laser wavelengths, and laser intensities is surveyed to identify favorable regimes for this effect. Output laser intensities of 10(superscript ''17'') W/cm(superscript ''2'') for 0.5 mm radiation are found to be feasible for such a scheme using a pump of 10(superscript ''13'') W/cm(superscript ''2'') and an initial seed of 5 x 10(superscript ''14'') W/cm(superscript ''2'') over an amplification length of 5.6 cm in hydrogen gas

  2. A Kinetics Model for KrF Laser Amplifiers

    Science.gov (United States)

    Giuliani, J. L.; Kepple, P.; Lehmberg, R.; Obenschain, S. P.; Petrov, G.

    1999-11-01

    A computer kinetics code has been developed to model the temporal and spatial behavior of an e-beam pumped KrF laser amplifier. The deposition of the primary beam electrons is assumed to be spatially uniform and the energy distribution function of the nascent electron population is calculated to be near Maxwellian below 10 eV. For an initial Kr/Ar/F2 composition, the code calculates the densities of 24 species subject to over 100 reactions with 1-D spatial resolution (typically 16 zones) along the longitudinal lasing axis. Enthalpy accounting for each process is performed to partition the energy into internal, thermal, and radiative components. The electron as well as the heavy particle temperatures are followed for energy conservation and excitation rates. Transport of the lasing photons is performed along the axis on a dense subgrid using the method of characteristics. Amplified spontaneous emission is calculated using a discrete ordinates approach and includes contributions to the local intensity from the whole amplifier volume. Specular reflection off side walls and the rear mirror are included. Results of the model will be compared with data from the NRL NIKE laser and other published results.

  3. Construction and design of CO2-laser amplifiers with self-sustained and electron-beam-controlled gas discharge

    International Nuclear Information System (INIS)

    Schmid, W.E.

    1975-08-01

    Following a description of the fundamentals and of the manner of functioning of CO 2 lasers, a theoretical and experimental investigation is performed to see whether the self-sustained or the non-self-sustained gas discharge is suitable for an amplifier in a CO 2 high-power laser system. The measured results show that the excitation by non-self-sustained gas discharge is more advantageous for amplifiers. The reasons are given. (GG/LH) [de

  4. Tunable high-power narrow-spectrum external-cavity diode laser based on tapered amplifier at 668 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Erbert, G.; Sumpf, B.

    2010-01-01

    A 668 nm tunable high-power narrow-spectrum diode laser system based on a tapered semiconductor optical amplifier in external cavity is demonstrated. The laser system is tunable from 659 to 675 nm. As high as 1.38 W output power is obtained at 668.35 nm. The emission spectral bandwidth is less than...

  5. A Hybrid Fiber/Solid-State Regenerative Amplifier with Tunable Pulse Widths for Satellite Laser Ranging

    Science.gov (United States)

    Coyle, Barry; Poulios, Demetrios

    2013-01-01

    A fiber/solid-state hybrid seeded regenerative amplifier, capable of achieving high output energy with tunable pulse widths, has been developed for satellite laser ranging applications. The regenerative amplifier cavity uses a pair of Nd:YAG zigzag slabs oriented orthogonally to one another in order to make thermal lensing effects symmetrical and simplify optical correction schemes. The seed laser used is a fiber-coupled 1,064-nm narrowband (pumped by a single 120-W, pulsed 808-nm laser diode array. In this configuration, the average pump beam distribution in the slabs had a 1-D Gaussian shape, which matches the estimated cavity mode size. A half-wave plate between the slabs reduces losses from Fresnel reflections due to the orthogonal slabs Brewster-cut end faces. Successful "temporal" seeding of the regenerative amplifier cavity results in a cavity Q-switch pulse envelope segmenting into shorter pulses, each having the width of the input seed, and having a uniform temporal separation corresponding to the cavity round-trip time of approx. =10 ns. The pulse energy is allowed to build on successive passes in the regenerative amplifier cavity until a maximum is reached, (when cavity gains and losses are equal), after which the pulse is electro- optically switched out on the next round trip The overall gain of the amplifier is approx. =82 dB (or a factor of 1.26 million). After directing the amplified output through a LBO frequency doubling crystal, approx. = 2.1 W of 532-nm output (>1 mJ) was measured. This corresponds to a nonlinear conversion efficiency of >60%. Furthermore, by pulse pumping this system, a single pulse per laser shot can be created for the SLR (satellite laser ranging) measurement, and this can be ejected into the instrument. This is operated at the precise frequency needed by the measurement, as opposed to commercial short-pulsed, mode-locked systems that need to operate in a continuous fashion, or CW (continuous wave), and create pulses at many

  6. Induction-linac based free-electron laser amplifiers for plasma heating

    International Nuclear Information System (INIS)

    Jong, R.A.

    1988-01-01

    We describe an induction-linac based free-electron laser amplifier that is presently under construction at the Lawrence Livermore National Laboratory. It is designed to produce up to 2 MW of average power at a frequency of 250 GHz for plasma heating experiments in the Microwave Tokamak Experiment. In addition, we shall describe a FEL amplifier design for plasma heating of advanced tokamak fusion devices. This system is designed to produce average power levels of about 10 MW at frequencies ranging form 280 to 560 GHz. 7 refs., 1 tab

  7. Studies of high repetition rate laser-produced plasma soft-X-ray amplifiers

    International Nuclear Information System (INIS)

    Cassou, K.

    2006-12-01

    The progress made as well on the Ti:Sa laser system, as in the control and the knowledge of laser produced X-UV sources allowed the construction of a X-UV laser station dedicated to the applications. My thesis work falls under the development of this station and more particularly on the characterization of a X-UV laser plasma amplifier. The experimental study relates to the coupling improvement of the pump infra-red laser with plasma within the framework of the transient collisional X-UV laser generation. These X-UV lasers are generated in a plasma formed by the interaction of a solid target and a laser pulse of approximately 500 ps duration, followed by a second infra-red laser pulse known as of pump (about 5 ps) impinging on the target in grazing incidence. For the first time, a complete parametric study was undertaken on the influence of the grazing angle on the pumping of the amplifying medium. One of the results was to reach very high peak brightness about 10 28 ph/s/mm 2 /mrad 2 /(0.1%bandwidth), which compares well with the free-electron laser brightness. Moreover, we modified then used a new two-dimensional hydrodynamic code with adaptive mesh refinement in order to understand the influence of the space-time properties of the infra-red laser on the formation and the evolution of the amplifying plasma. Our modeling highlighted the interest to use a super Gaussian transverse profile for the line focus leading to an increase in a factor two of the gain region size and a reduction of the electron density gradient by three orders of magnitude. These improvements should strongly increase the energy contained in X-UV laser beam. We thus used X-UV laser to study the appearance of transient defects produced by a laser IR on a beam-splitter rear side. We also began research on the mechanisms of DNA damage induced by a very intense X-UV radiation. (author)

  8. High-power diode laser bars as pump sources for fiber lasers and amplifiers (Invited Paper)

    Science.gov (United States)

    Bonati, G.; Hennig, P.; Wolff, D.; Voelckel, H.; Gabler, T.; Krause, U.; T'nnermann, A.; Reich, M.; Limpert, J.; Werner, E.; Liem, A.

    2005-04-01

    Fiber lasers are pumped by fibercoupled, multimode single chip devices at 915nm. That"s what everybody assumes when asked for the type of fiber laser pumps and it was like this for many years. Coming up as an amplifier for telecom applications, the amount of pump power needed was in the range of several watts. Highest pump powers for a limited market entered the ten watts range. This is a range of power that can be covered by highly reliable multimode chips, that have to survive up to 25 years, e.g. in submarine applications. With fiber lasers entering the power range and the application fields of rod and thin disc lasers, the amount of pump power needed raised into the area of several hundred watts. In this area of pump power, usually bar based pumps are used. This is due to the much higher cost pressure of the industrial customers compared to telecom customers. We expect more then 70% of all industrial systems to be pumped by diode laser bars. Predictions that bar based pumps survive for just a thousand hours in cw-operation and fractions of this if pulsed are wrong. Bar based pumps have to perform on full power for 10.000h on Micro channel heat sinks and 20.000h on passive heatsinks in industrial applications, and they do. We will show a variety of data, "real" long time tests and statistics from the JENOPTIK Laserdiode as well as data of thousands of bars in the field, showing that bar based pumps are not just well suitable for industrial applications on high power levels, but even showing benefits compared to chip based pumps. And it"s reasonable, that the same objectives of cost effectiveness, power and lifetime apply as well to thin disc, rod and slab lasers as to fiber lasers. Due to the pumping of fiber lasers, examples will be shown, how to utilize bars for high brightness fiber coupling. In this area, the automation is on its way to reduce the costs on the fibercoupling, similar to what had been done in the single chip business. All these efforts are

  9. Repetitive output laser system and method using target reflectivity

    International Nuclear Information System (INIS)

    Johnson, R.R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet is described in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target refγlection

  10. Aurora laser optical system

    International Nuclear Information System (INIS)

    Hanlon, J.A.; McLeod, J.

    1987-01-01

    Aurora is the Los Alamos short-pulse high-power krypton fluoride laser system. It is primarily an end-to-end technology demonstration prototype for large-scale UV laser systems of interest for short-wavelength inertial confinement fusion (ICF) investigations. The system is designed to employ optical angular multiplexing and aerial amplification by electron-beam-driven KrF laser amplifiers to deliver to ICF targets a stack of pulses with a duration of 5 ns containing several kilojoules at a wavelength of 248 nm. A program of high-energy density plasma physics investigations is now planned, and a sophisticated target chamber was constructed. The authors describe the design of the optical system for Aurora and report its status. This optical system was designed and is being constructed in two phases. The first phase carries only through the amplifier train and does not include a target chamber or any demultiplexing. Installation should be complete, and some performance results should be available. The second phase provides demultiplexing and carries the laser light to target. The complete design is reported

  11. Study of the Powerful Nd:YLF Laser Amplifiers for the CTF3 Photoinjectors

    CERN Document Server

    Petrarca, M; Luchinin, G; Divall, M

    2011-01-01

    A high-power neodymium-doped yttrium lithium fluoride (Nd:YLF) mode-locked 1.5-GHz laser currently used to drive the two photoinjectors of the Compact Linear Collider Test Facility project at the European Organization for Nuclear Research is described. A phenomenological characterization of the two powerful Nd:YLF amplifiers is presented and compared with the measurements. The laser system operates in a saturated steady-state mode. This mode provides good shot-to-shot stability with pulse train mean power in the 10 kW range.

  12. Millimeter wave free electron laser amplifiers: Experiments and designs

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Zhang, Z.X.; Antonsen, T.M. Jr.; Bensen, D.M.; Destler, W.W.; Granatstein, V.L.; Lantham, P.E.; Levush, B.; Rodgers, J.

    1991-01-01

    Free electron laser amplifies are investigated as sources of high- average-power (1 MW) millimeter to submillimeter wave radiation (200 GHz - 600 GHz) for application to electron cyclotron resonance heating of magnetically confined fusion plasmas. As a stepping-stone to higher frequencies and cw operation a pulsed amplifier (τ pulse ≅ 80 ns) at 98 GHz is being developed. Status is reported on this experiment which investigates linear gain amplification with use of sheet electron beam (transverse cross section = 0.1 cm x 2.0 cm, V beam = 440 keV, I beam ≅ 10 A) and short-period wiggler (ell w = 0.96 cm) and with expected output of 140 W. Predictions of gain and efficiency from a 1-D universal formulation are presented. Beam propagation results, with wiggler focusing as a means of sheet beam confinement in both transverse dimensions, through the 54 cm (56 period) pulsed electromagnet wiggler are discussed. Peak wiggler fields of 5.1 kG on-axis have been achieved

  13. Preliminary design of experiment high power density laser beam interaction with plasmas and development of a cold cathode electron beam laser amplifier

    International Nuclear Information System (INIS)

    Mosavi, R.K.; Kohanzadeh, Y.; Taherzadeh, M.; Vaziri, A.

    1976-01-01

    This experiment is designed to produce plasma by carbon dioxide pulsed laser, to measure plasma parameters and to study the interaction of the produced plasma with intense laser beams. The objectives of this experiment are the following: 1. To set up a TEA CO 2 laser oscillator and a cold cathode electron beam laser amplifier together as a system, to produce high energy optical pulses of short duration. 2. To achieve laser intensities of 10 11 watt/cm 2 or more at solid targets of polyethylene (C 2 H 4 )n, lithium hydride (LiH), and lithium deuteride in order to produce high temperature plasmas. 3. To design and develop diagnostic methods for studies of laser-induced plasmas. 4. To develop a high power CO 2 laser amplifier for the purpose of upgrading the optical energy delivered to the targets

  14. All-metal coupling and package of semiconductor laser and amplifier with optical fiber

    International Nuclear Information System (INIS)

    Xu Fenglan; Li Lina; Zhang Yueqing

    1992-01-01

    The semiconductor laser and optical amplifier made by Changchun Institute of Physics coupled with optical fiber by use of all-metal coupling are represented. The net gain of semiconductor laser amplifier with optical fiber is 14 ∼18 dB

  15. High-performace cladding-pumped erbium-doped fibre laser and amplifier

    International Nuclear Information System (INIS)

    Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Lipatov, D S; Vechkanov, N N; Guryanov, Aleksei N

    2012-01-01

    We report cladding-pumped erbium-doped fibre laser and amplifier configurations. Through fibre design optimisation, we have achieved a record-high laser slope efficiency, 40 % with respect to absorbed pump power (λ = 976 nm), and an output power of 7.5 W. The erbium-doped fibre amplifier efficiency reaches 32 %.

  16. High Power Amplifiers Chain nonlinearity influence on the accelerating beam stability in free electron laser (FLASH)

    CERN Document Server

    Cichalewski, w

    2010-01-01

    The high power amplifiers transfer characteristics nonlinearities can have a negative influence on the overall system performance. This is also true for the TESLA superconducting cavities accelerating field parameters control systems. This Low Level Radio Frequency control systems uses microwave high power amplifiers (like 10 MW klystrons) as actuators in the mentioned feedback loops. The amplitude compression and phase deviations phenomena introduced to the control signals can reduce the feedback performance and cause electron beam energy instabilities. The transfer characteristics deviations in the Free Electron Laser in Hamburg experiment have been investigated. The outcome of this study together with the description of the developed linearization method based on the digital predistortion approach have been described in this paper. Additionally, the results from the linearization tool performance tests in the FLASH's RF systems have been placed.

  17. High-power dual-wavelength external-Cavity diode laser based on tapered amplifier with tunable terahertz frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2011-01-01

    Tunable dual-wavelength operation of a diode laser system based on a tapered diode amplifier with double-Littrow external-cavity feedback is demonstrated around 800nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 5:0 THz......, this is the highest output power from a dual-wavelength diode laser system operating with tunable terahertz frequency difference. © 2011 Optical Society of America....

  18. Self-amplified spontaneous emission free electron laser devices and nonideal electron beam transport

    Directory of Open Access Journals (Sweden)

    L. L. Lazzarino

    2014-11-01

    Full Text Available We have developed, at the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL device performance control. We describe an actual FEL, including electron and optical beam transport, through a set of analytical formulas, allowing a fast and reliable on-line “simulation” of the experiment. The system is designed in such a way that the characteristics of the transport elements and the laser intensity are measured and adjusted, via a real time computation, during the experimental run, to obtain an on-line feedback of the laser performances. The detail of the procedure and the relevant experimental results are discussed.

  19. Auto-locking waveguide amplifier system for lidar and magnetometric applications

    Science.gov (United States)

    Pouliot, A.; Beica, H. C.; Carew, A.; Vorozcovs, A.; Carlse, G.; Kumarakrishnan, A.

    2018-02-01

    We describe a compact waveguide amplifier system that is suitable for optically pumping rubidium magnetometers. The system consists of an auto-locking vacuum-sealed external cavity diode laser, a semiconductor tapered amplifier and a pulsing unit based on an acousto-optic modulator. The diode laser utilises optical feedback from an interference filter to narrow the linewidth of an inexpensive laser diode to 500 kHz. This output is scannable over an 8 GHz range (at 780 nm) and can be locked without human intervention to any spectral marker in an expandable library of reference spectra, using the autolocking controller. The tapered amplifier amplifies the output from 50 mW up to 2 W with negligible distortions in the spectral quality. The system can operate at visible and near infrared wavelengths with MHz repetition rates. We demonstrate optical pumping of rubidium vapour with this system for magnetometric applications. The magnetometer detects the differential absorption of two orthogonally polarized components of a linearly polarized probe laser following optical pumping by a circularly polarized pump laser. The differential absorption signal is studied for a range of pulse lengths, pulse amplitudes and DC magnetic fields. Our results suggest that this laser system is suitable for optically pumping spin-exchange free magnetometers.

  20. Criterion of transverse coherence of self-amplified spontaneous emission in high gain free electron laser amplifiers

    International Nuclear Information System (INIS)

    Xie, M.; Kim, K.J.

    1995-01-01

    In a high gain free electron laser amplifier based on Self-Amplified Spontaneous Emission (SASE) the spontaneous radiation generated by an electron beam near the undulator entrance is amplified many orders of magnitude along the undulator. The transverse coherence properties of the amplified radiation depends on both the amplification process and the coherence of the seed radiation (the undulator radiation generated in the first gain length or so). The evolution of the transverse coherence in the amplification process is studied based on the solution of the coupled Maxwell-Vlasov equations including higher order transverse modes. The coherence of the seed radiation is determined by the number of coherent modes in the phase space area of the undulator radiation. We discuss the criterion of transverse coherence and identify governing parameters over a broad range of parameters. In particular we re-examine the well known emittance criterion for the undulator radiation, which states that full transverse coherence is guaranteed if the rms emittance is smaller than the wavelength divided by 4π. It is found that this criterion is modified for SASE because of the different optimization conditions required for the electron beam. Our analysis is a generalization of the previous study by Yu and Krinsky for the case of vanishing emittance with parallel electron beam. Understanding the transverse coherence of SASE is important for the X-ray free electron laser projects now under consideration at SLAC and DESY

  1. 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

  2. Free electron laser amplifier experiments on SG-1

    International Nuclear Information System (INIS)

    Hui Zhongxi; Zhou Chuanming; Wu Ruian

    1994-01-01

    The SG-1 FEL facility is composed of a linear induction accelerator (LIA), an electron beam transport system, a wiggler, a microwave source and a diagnostic system. SG-1 LIA provides a 2 kA, 3.0 MeV beam with a normalized emittance of 0.4∼0.6 (π rad·cm), an energy spread (FWHM) of 4%, resulting in a beam brightness of nearly 10 8 A/πm·rad) 2[1] . The beam current through the wiggler is about 600 A. The first ASE experiments began in September 1991. A 2.6-m long wiggler with a peak magnetic field of 0.3 T was used. At 35.8∼36.5 GHz an ASE output of 0.5 W was obtained for a beam current of nearly 50 A. After a shutdown of about 8 months, the second series of ASE experiments began in October 1992. The second series of ASE experiments were performed with a wiggler magnetic field between 0.25∼0.27 T. The maximum output power is about 100 kw for B w = 0.24 T, I = 600 A, At ν = 35.2 GHz. Based on the ASE experiments the amplifier experiments was carried out on SG-1. Using an 300 W input signal (TE 01 ), a beam current of about 600 A and wiggler magnetic fields of 0.24∼0.28 T, the authors measured the FEL output power as a function of the wiggler magnetic field. The resonant magnetic field was about 0.25 T. Meanwhile, in order to study the amplifier gain, the authors measured the FEL output power as a function of the wiggler length at a peak wiggler magnetic field of 0.26 T. The exponential gain is approximately 19 dB/m and the maximum output power is about 10 MW

  3. Stabilization in laser wavelength semiconductor with fiber optical amplifier application doped with erbium

    International Nuclear Information System (INIS)

    Camas, J.; Anzueto, G.; Mendoza, S.; Hernandez, H.; Garcia, C.; Vazquez, R.

    2009-01-01

    In this work, we present a novel electronic design of a DC source, which automatically controls the temperature of a tunable laser. The temperature change in the laser is carried out by the control of DC that circulates through a cooling stage where the laser is set. The laser can be tuned in a wavelength around 1550 nm. Its application is in Erbium Doped Fiber Amplifier (EDFA) in reflective configuration. (Author)

  4. High-performance OPCPA laser system

    International Nuclear Information System (INIS)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J.

    2006-01-01

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  5. High-performance OPCPA laser system

    Energy Technology Data Exchange (ETDEWEB)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J. [Rochester Univ., Lab. for Laser Energetics, NY (United States)

    2006-06-15

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  6. KrF amplifier design issues and application to inertial confinement fusion system design

    International Nuclear Information System (INIS)

    Sullivan, J.A.; Allen, G.R.; Berggren, R.R.

    1993-01-01

    Los Alamos National Laboratory has assembled an array of experimental and theoretical tools to optimize amplifier design for future single-pulse KrF lasers. The next opportunity to exercise these tools is with the design of the second-generation NIKE system under construction at the Naval Research Laboratory with the collaboration of Los Alamos National Laboratory. Los Alamos has applied these amplifier design tools to the conceptual design of a 100-kJ Laser Target Test Facility and a 3-MJ Laboratory Microfusion Facility. (author)

  7. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

    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.

  8. Radially resolved simulation of a high-gain free electron laser amplifier

    International Nuclear Information System (INIS)

    Fawley, W.M.; Prosnitz, D.; Doss, S.; Gelinas, R.

    1983-01-01

    The results of a two-dimensional simulation of a high-gain free electron laser (FEL) amplifier is presented. The simulation solves the inhomogeneous paraxial wave equation. The source term is radially resolved and is obtained by tracking the interaction of the laser field with localized macroparticles

  9. Measurement of carrier lifetime and linewidth enhancement factor for 1.5- mu m ridge-waveguide laser amplifier

    DEFF Research Database (Denmark)

    Storkfelt, Niels; Mikkelsen, B.; Olesen, D. S.

    1991-01-01

    Semiconductor optical amplifiers are used for investigation of the effective carrier lifetime and the linewidth enhancement factor. Contrary to semiconductor lasers, semiconductor optical amplifiers allow measurement at high levels of injected carrier density. The carrier lifetime and the linewid...

  10. Amplification of UV ultrashort pulse laser in e-beam pumped KrF amplifier

    CERN Document Server

    Tang Xiu Zhang; Gong Kun; Ma Wei Yi; Shan Yu Sheng; Wang Nai Yan

    2002-01-01

    Experimental investigations were performed for amplification of ultrashort pulse laser with Heaven-I e-beam pumped KrF amplifier in CIAE. A 50 mJ, 420 fs UV ultrashort pulse was amplified to 2-3 J energy, 1.2 ps pulse duration, and 2TW laser power. Experimental technique such as synchronization were describe, some parameters such as nonlinear absorb coefficient were measured in experiment. As a result, it is possible to achieve ultra-strong UV laser with intensity higher than 10 sup 1 sup 9 W/cm sup 2 in recently years

  11. Amplification of UV ultrashort pulse laser in e-beam pumped KrF amplifier

    International Nuclear Information System (INIS)

    Tang Xiuzhang; Zhang Haifeng; Gong Kun; Ma Weiyi; Shan Yusheng; Wang Naiyan

    2002-01-01

    Experimental investigations were performed for amplification of ultrashort pulse laser with Heaven-I e-beam pumped KrF amplifier in CIAE. A 50 mJ, 420 fs UV ultrashort pulse was amplified to 2-3 J energy, 1.2 ps pulse duration, and 2TW laser power. Experimental technique such as synchronization were describe, some parameters such as nonlinear absorb coefficient were measured in experiment. As a result, it is possible to achieve ultra-strong UV laser with intensity higher than 10 19 W/cm 2 in recently years

  12. High peak power picosecond hybrid fiber and solid-state amplifier system

    International Nuclear Information System (INIS)

    Wushouer, X; Yan, P; Yu, H; Liu, Q; Fu, X; Yan, X; Gong, M

    2010-01-01

    We report the high peak power picosecond hybrid fiber and solid-state laser amplifier system. The passively mode-locked solid-state seed source produced an average power of 1.8 W with pulse width of 14 ps and repetition rate of 86 MHz. It was directly coupled into the first Yb-doped polarized photonic crystal fiber amplifier stage. To avoid the nonlinear effects in fiber, the output power from the first stage was merely amplified to 24 W with the narrow spectra broadening of 0.21 nm. For the improvement of the peak power, the dual-end pumped composite Nd:YVO 4 amplifier system has been chosen at the second stage. To reduce the serious thermal effect, the thermally bonded composite YVO 4 – Nd:YVO 4 – YVO 4 rod crystal was used as the gain medium. The 53 W TEM 00 mode with the peak power of 40 kW, beam quality of M 2 < 1.15, corresponding to the optical-optical efficiency of 42.4% was obtained at the hybrid amplifier laser system. The system allows using a low power seed source and demonstrates an increase in the peak power beyond a fiber master oscillator power amplifier's (MOPA's) limit

  13. Pulse shaping amplifier (PSA) for nuclear spectroscopy system

    International Nuclear Information System (INIS)

    Lombigit, L.; Maslina Mohd Ibrahim; Nolida Yusup; Nur Aira Abdul Rahman; Yong, C.F.

    2014-01-01

    Pulse Shaping Amplifier (PSA) is an essential components in nuclear spectroscopy system. This networks have two functions; to shape the output pulse and performs noise filtering. In this paper, we describes procedure for design and development of a pulse shaping amplifier which can be used for nuclear spectroscopy system. This prototype was developed using high performance electronics devices and assembled on a FR4 type printed circuit board. Performance of this prototype was tested by comparing it with an equivalent commercial spectroscopy amplifier (Model SILENA 7611). The test results show that the performance of this prototype is comparable to the commercial spectroscopic amplifier. (author)

  14. Closely spaced mirror pair for reshaping and homogenizing pump beams in laser amplifiers

    International Nuclear Information System (INIS)

    Bass, I.L.

    1992-12-01

    Channeling a laser beam by multiple reflections between two closely-spaced, parallel or nearly parallel mirrors, serves to reshape and homogenize the beam at the output gap between the mirrors. Application of this device to improve the spatial overlap of a copper laser pump beam with the signal beam in a dye laser amplifier is described. This technique has been applied to the AVLIS program at the Lawrence Livermore National Laboratory

  15. Spot-shadowing optimization to mitigate damage growth in a high-energy-laser amplifier chain.

    Science.gov (United States)

    Bahk, Seung-Whan; Zuegel, Jonathan D; Fienup, James R; Widmayer, C Clay; Heebner, John

    2008-12-10

    A spot-shadowing technique to mitigate damage growth in a high-energy laser is studied. Its goal is to minimize the energy loss and undesirable hot spots in intermediate planes of the laser. A nonlinear optimization algorithm solves for the complex fields required to mitigate damage growth in the National Ignition Facility amplifier chain. The method is generally applicable to any large fusion laser.

  16. Erbium-doped integrated waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Bradley, J.; Pollnau, Markus

    Erbium-doped fiber devices have been extraordinarily successful due to their broad optical gain around 1.5–1.6 μm. Er-doped fiber amplifiers enable efficient, stable amplification of high-speed, wavelength-division-multiplexed signals, thus continue to dominate as part of the backbone of longhaul

  17. Semipolar InGaN quantum-well laser diode with integrated amplifier for visible light communications

    KAUST Repository

    Shen, Chao

    2018-02-14

    GaN-based semiconductor optical amplifier (SOA) and its integration with laser diode (LD) is an essential building block yet to be demonstrated for III-nitride photonic integrated circuits (PICs) at visible wavelength. This paper presents the InGaN/GaN quantum well (QW) based dual-section LD consisting of integrated amplifier and laser gain regions fabricated on a semipolar GaN substrate. The threshold current in the laser gain region was favorably reduced from 229mA to 135mA at SOA driving voltages, VSOA, of 0V and 6.25V, respectively. The amplification effect was measured based on a large gain of 5.7 dB at VSOA = 6.25V from the increased optical output power of 8.2 mW to 30.5 mW. Such integrated amplifier can be modulated to achieve Gbps data communication using on-off keying technique. The monolithically integrated amplifier-LD paves the way towards the III-nitride on-chip photonic system, providing a compact, low-cost, and multi-functional solution for applications such as smart lighting and visible light communications.

  18. Semipolar InGaN quantum-well laser diode with integrated amplifier for visible light communications

    KAUST Repository

    Shen, Chao; Ng, Tien Khee; Lee, Changmin; Nakamura, Shuji; Speck, James S.; DenBaars, Steven P.; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

    2018-01-01

    GaN-based semiconductor optical amplifier (SOA) and its integration with laser diode (LD) is an essential building block yet to be demonstrated for III-nitride photonic integrated circuits (PICs) at visible wavelength. This paper presents the InGaN/GaN quantum well (QW) based dual-section LD consisting of integrated amplifier and laser gain regions fabricated on a semipolar GaN substrate. The threshold current in the laser gain region was favorably reduced from 229mA to 135mA at SOA driving voltages, VSOA, of 0V and 6.25V, respectively. The amplification effect was measured based on a large gain of 5.7 dB at VSOA = 6.25V from the increased optical output power of 8.2 mW to 30.5 mW. Such integrated amplifier can be modulated to achieve Gbps data communication using on-off keying technique. The monolithically integrated amplifier-LD paves the way towards the III-nitride on-chip photonic system, providing a compact, low-cost, and multi-functional solution for applications such as smart lighting and visible light communications.

  19. Optically amplifying planar glass waveguides: Laser on a chip

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas

    with UV-light and that permanent Bragg-gratings can be induced. Planar waveguide lasers with integrated Bragg-gratings are manufactured and characterised. It is shown that linewidths below 125 kHz and output powers around 0.5 mW can be obtained, and that the manufactured lasers are resistant to mechanical...... lightwave circuits, as well as provide the gain medium for integrated planar waveguide lasers. The work and the obtained results are presented in this thesis: The manufacturing of silica thin films is described and it is shown that the refractive index of the films can be controlled by germanium co...... as well as thermal influence. A simple method for producing an array of planar waveguide lasers is presented and it is shown that the difference in output wavelength of the individual lasers can be controlled with great accuracy....

  20. Planar waveguide amplifiers and laser in erbium doped silica

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas; Kristensen, Martin

    1999-01-01

    with UV-light and that permanent Bragg-gratings can be induced. Planar waveguide lasers with integrated Bragg-gratings are manufactured and characterised. It is shown that linewidths below 125 kHz and output powers around 0.5 mW can be obtained, and that the manufactured lasers are resistant to mechanical...... lightwave circuits, as well as provide the gain medium for integrated planar waveguide lasers. The work and the obtained results are presented in this thesis: The manufacturing of silica thin films is described and it is shown that the refractive index o fthe films can be controlled by germanium co...... as well as thermal influence. A simple method for producing an array of planar waveguide lasers is presented and it is shown that the difference in output wavelength of the individual lasers can be controlled with great accuracy....

  1. Effects of chemical kinetics and starting material regeneration on the efficiency of an iodine laser amplifier

    International Nuclear Information System (INIS)

    Fisk, G.A.

    1977-05-01

    A model of the chemical kinetics occurring in an iodine laser amplifier is presented and used to calculate the degree to which the starting material is consumed as a result of laser operation. The cost of purchasing new starting material is estimated and shown to be prohibitive. A scheme for regenerating the starting material from the species present in the amplifier after lasing is proposed. It is shown that the estimated efficiency of this chemical regeneration process is appreciably higher than the projected optimum efficiency of the pumping process

  2. Laser amplifier based on a neodymium glass rod 150 mm in diameter

    Energy Technology Data Exchange (ETDEWEB)

    Shaykin, A A; Fokin, A P; Soloviev, A A; Kuzmin, A A; Shaikin, I A; Burdonov, K F; Khazanov, E A [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation); Charukhchev, A V [Public Limited Company " Scientific research Institute for Optoelectronic Instrument Engineering" , Leningrad region (Russian Federation)

    2014-05-30

    A unique large-aperture neodymium glass rod amplifier is experimentally studied. The small-signal gain distribution is measured at different pump energies. The aperture-averaged gain is found to be 2.3. The stored energy (500 J), the maximum possible pump pulse repetition rate, and the depolarisation in a single pulse and in a series of pulses with a repetition rate of one pulse per five minutes are calculated based on the investigations performed. It is shown that the use of this amplifier at the exit of the existing laser can increase the output pulse energy from 300 to 600 J. (lasers)

  3. Electron transport in solid targets and in the active mixture of a CO2 laser amplifier

    Science.gov (United States)

    Galkowski, A.

    The paper examines the use of the NIKE code for the Monte Carlo computation of the deposited energy profile and other characteristics of the absorption process of an electron beam in a solid target and the spatial distribution of primary ionization in the active mixture of a CO2 laser amplifier. The problem is considered in connection with the generation of intense electron beams and the acceleration of thin metal foils, as well as in connection with the electric discharge pumping of a CO2 laser amplifier.

  4. Status report on cleaning and maintaining laser disk amplifiers

    International Nuclear Information System (INIS)

    Patton, H.G.; Stowers, I.F.; Jones, W.A.; Wentworth, D.E.

    1978-01-01

    This report describes the activities and advances in engineering and technology made by the Solid State Mechanical Maintenance Group within the laser program at Lawrence Livermore Laboratory. It includes design and operation of clean rooms, contamination control on optical surfaces, cleaning techniques, and glass damage mechanisms. This report, a much expanded version of a section in the laser program's 1976 annual report, covers work accomplished from July 1976 to April 1977. It has been used as the source for five papers presented at various national conferences

  5. High repetition rate tunable femtosecond pulses and broadband amplification from fiber laser pumped parametric amplifier.

    Science.gov (United States)

    Andersen, T V; Schmidt, O; Bruchmann, C; Limpert, J; Aguergaray, C; Cormier, E; Tünnermann, A

    2006-05-29

    We report on the generation of high energy femtosecond pulses at 1 MHz repetition rate from a fiber laser pumped optical parametric amplifier (OPA). Nonlinear bandwidth enhancement in fibers provides the intrinsically synchronized signal for the parametric amplifier. We demonstrate large tunability extending from 700 nm to 1500 nm of femtosecond pulses with pulse energies as high as 1.2 muJ when the OPA is seeded by a supercontinuum generated in a photonic crystal fiber. Broadband amplification over more than 85 nm is achieved at a fixed wavelength. Subsequent compression in a prism sequence resulted in 46 fs pulses. With an average power of 0.5 W these pulses have a peak-power above 10 MW. In particular, the average power and pulse energy scalability of both involved concepts, the fiber laser and the parametric amplifier, will enable easy up-scaling to higher powers.

  6. An optical parametric chirped-pulse amplifier for seeding high repetition rate free-electron lasers

    International Nuclear Information System (INIS)

    Höppner, H; Hage, A; Tanikawa, T; Schulz, M; Faatz, B; Riedel, R; Prandolini, M J; Teubner, U; Tavella, F

    2015-01-01

    High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond lasers for FEL seeding and FEL pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720–900 nm, pulse energies up to 1.12 mJ and a pulse duration of 30 fs at a repetition rate of 100 kHz. Since the power scalability of this OPCPA is limited by the OPCPA-pump amplifier, we also demonstrate a 6.7–13.7 kW (burst mode) thin-disk OPCPA-pump amplifier, increasing the possible OPCPA output power to many hundreds of watts. Furthermore, third and fourth harmonic generation experiments are performed and the results are used to simulate a seeded FEL with high-gain harmonic generation. (paper)

  7. InP based lasers and optical amplifiers with wire-/dot-like active regions

    DEFF Research Database (Denmark)

    Reithmaier, J. P.; Somers, A.; Deubert, S.

    2005-01-01

    Long wavelength lasers and semiconductor optical amplifiers based on InAs quantum wire/dot-like active regions were developed on InP substrates dedicated to cover the extended telecommunication wavelength range between 1.4 - 1.65 mm. In a brief overview different technological approaches will be ...

  8. High gain semiconductor optical amplifierLaser diode at visible wavelength

    KAUST Repository

    Shen, Chao; Lee, Changmin; Ng, Tien Khee; Nakamura, Shuji; Speck, James S.; DenBaars, Steven P.; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

    2017-01-01

    We reported on the first experimental demonstration of a two-section semipolar InGaN-based laser diode with monolithically integrated semiconductor optical amplifier (SOA-LD). The onset of amplification effect was measured at 4V SOA bias (VSOA). The SOA-LD shows a large gain of 5.32 dB at Vsoa = 6 V.

  9. High gain semiconductor optical amplifierLaser diode at visible wavelength

    KAUST Repository

    Shen, Chao

    2017-02-07

    We reported on the first experimental demonstration of a two-section semipolar InGaN-based laser diode with monolithically integrated semiconductor optical amplifier (SOA-LD). The onset of amplification effect was measured at 4V SOA bias (VSOA). The SOA-LD shows a large gain of 5.32 dB at Vsoa = 6 V.

  10. Amplified spontaneous emission of an end-pumped cesium vapor laser

    International Nuclear Information System (INIS)

    An, Guofei; Wang, You; Cai, He; Han, Juhong; Wang, Shunyan; Rong, Kepeng; Yu, Hang; Xue, Liangping; Zhang, Wei; Wang, Hongyuan; Zhou, Jie

    2017-01-01

    Diode pumped alkali lasers (DPALs) provide a significant potential for construction of high-powered lasers. A series of models have been established to analyze the DPAL’s kinetic process and most of them are based on the algorithms in which the amplified spontaneous emission (ASE) effect has not been considered. However, ASE is harmful in realization of a high-powered DPAL since the gain is very high. Usually, ASE becomes serious when the volume of the gain medium is large and the pump power is high. Basically, the conclusions we obtained in this study can be extended to other kinds of laser configurations. (paper)

  11. Laser amplification of optical images using a CW Nd:YAG amplifier

    International Nuclear Information System (INIS)

    Aman, H

    2013-01-01

    In this paper a scheme for the amplification of optical images is described, using a continuous wave (CW) diode-pumped Nd:YAG (yttrium aluminum garnet) laser module. A passively q-switched end-pumped Nd:YAG laser is used as a pump source, which carries the optical image distribution as an input which is transmitted towards the amplifier at a distance of about ten feet. For amplification, a three-side-pumped CW Nd:YAG laser module is utilized without the cavity mirrors. In this way, optical images are amplified by a factor of 3.2 and imaged at a distance of ten feet with a spatial resolution of 500 μm. (paper)

  12. Embedded control system for high power RF amplifiers

    International Nuclear Information System (INIS)

    Sharma, Deepak Kumar; Gupta, Alok Kumar; Jain, Akhilesh; Hannurkar, P.R.

    2011-01-01

    RF power devices are usually very sensitive to overheat and reflected RF power; hence a protective interlock system is required to be embedded with high power solid state RF amplifiers. The solid state RF amplifiers have salient features of graceful degradation and very low mean time to repair (MTTR). In order to exploit these features in favour of lowest system downtime, a real-time control system is embedded with high power RF amplifiers. The control system is developed with the features of monitoring, measurement and network publishing of various parameters, historical data logging, alarm generation, displaying data to the operator and tripping the system in case of any interlock failure. This paper discusses the design philosophy, features, functions and implementation details of the embedded control system. (author)

  13. Directional amplifier in an optomechanical system with optical gain

    Science.gov (United States)

    Jiang, Cheng; Song, L. N.; Li, Yong

    2018-05-01

    Directional amplifiers are crucial nonreciprocal devices in both classical and quantum information processing. Here we propose a scheme for realizing a directional amplifier between optical and microwave fields based on an optomechanical system with optical gain, where an active optical cavity and two passive microwave cavities are coupled to a common mechanical resonator via radiation pressure. The two passive cavities are coupled via hopping interaction to facilitate the directional amplification between the active and passive cavities. We obtain the condition of achieving optical directional amplification and find that the direction of amplification can be controlled by the phase differences between the effective optomechanical couplings. The effects of the gain rate of the active cavity and the effective coupling strengths on the maximum gain of the amplifier are discussed. We show that the noise added to this amplifier can be greatly suppressed in the large cooperativity limit.

  14. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including...... the basic physics and relevant in-depth theoretical modeling, amplifiers characteristics and performance data as a function of specific operation parameters. Typical applications in fiber optic communication systems and the improvement achievable through the use of fiber amplifiers are illustrated....

  15. Laser cavities with self-pumped phase conjugation by mixing of four waves in an amplifier

    International Nuclear Information System (INIS)

    Sillard, Pierre

    1998-01-01

    The purpose of this research thesis is to characterise a new type of cavities with self-pumped phase conjugation which uses a mixing of four waves degenerated in a solid amplifier. After a definition of phase conjugation and a brief overview of the history of this technique, the author describes and compares the different laser architectures with phase conjugation. He explains benefits and perspectives related to cavities with self-pumped phase conjugation using a mixing of four waves in an amplifier. He develops the necessary formalism for the resolution of the coupled equations of four wave mixing in transient regime for a resonant and saturated non-linearity. He shows how these results can be applied to solid amplifiers, in particularly to the Nd:YAG amplifier which is used in all experiments. In the next part, the author describes the principle and characteristics of cavity with self-pumped phase conjugation injected by another laser. An experiment is performed with two conventional Nd:YAG amplifiers pumped by flash lamps. The excellent performance of the cavity allows the study of cavity without this injection, but self-oscillating is to be envisaged, and a modelling of self-oscillating cavities is proposed and studied. Results are compared with those obtained with two N:YAG amplifiers pumped by flash lamps. Polarisation properties of the self-oscillating cavity are also studied. Finally, the author reports an experimental validation of a cavity with self-pumped phase conjugation all in solid state, pumped by laser diodes (a more efficient pumping) [fr

  16. Power Amplifier Design for E-band Wireless System Communications

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Krozer, Viktor; Johansen, Tom Keinicke

    2008-01-01

    E-band wireless communications will become important as the microwave backhaul for high-speed data transmission. One of the most critical components is the front-end power amplifier in this system. The paper analyzes different technologies with potential in the E-band frequency range and present...... a power amplifier design satisfying the E-band system specifications. The designed power amplifier achieves a maximum output power of ges 20 dBm with a state-of-the-art power-added efficiency of 15%. The power is realized using InP DHBT technology. To the best of our knowledge it is the highest output...... power and efficiency reported for an InP HBT power amplifier in this frequency range. The predicted power-added efficiency is higher than that of power amplifiers based on SiGe HBT and GaAs pHEMT technologies. The design shows the capabilities of InP DHBT for power amplifier applications...

  17. Development of a high power millimeter wave free-electron laser amplifier

    International Nuclear Information System (INIS)

    Bidwell, S.W.; Zhang, Z.X.; Antonsen, T.M. Jr.; Destler, W.W.; Granatstein, V.L.; Levush, B.; Rodgers, J.; Freund, H.P.

    1992-01-01

    Progress on the development of a high-average-power millimeter wave free-electron laser amplifier is reported. Successful sheet electron beam propagation has been observed through a 54 cm long wiggler magnet. One hundred percent transport efficiency is reported with a 15 A, 0.1 cm x 2.0 cm, sheet electron beam through B w = 5.1 kG, λ w = 0.96 cm, planar electromagnet wiggler. Preliminary success with a novel, yet simple, method of side focusing using offset poles is reported. Status of development on a 94 GHz, 180 kW, pulsed amplifier is discussed with results from numerical simulation

  18. Diode-pumped laser amplifiers: application to 0.946 {mu}m Nd:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Norman P [NASA Langley Research Center, Hampton, VA 23681 (United States); Axenson, Theresa J [Science and Technology Corporation, 10 Basil Sawyer Drive, Hampton, VA 23666 (United States); Jr, Donald J Reichle [NASA Langley Research Center, Hampton, VA 23681 (United States); Walsh, Brian M [NASA Langley Research Center, Hampton, VA 23681 (United States)

    2003-03-14

    A diode-pumped laser amplifier model is derived from first principles and applied to a Nd:YAG amplifier operating on the {sup 4}F{sub 3/2} to {sup 4}I{sub 9/2} transition at 0.946 {mu}m. The effects of amplified spontaneous emission are included in the model and the addition of this effect is shown to produce better agreement with the data. The amplifier model includes effects of the transverse and longitudinal variation of the pump beam, transverse and longitudinal variation of the probe beam, and multiple passes of the probe beam. Experimental results obtained with a quasi four-level Nd:YAG amplifier operating at 0.946 {mu}m are used to validate the model. The amplifier was evaluated as a function of the pump energy, the probe energy, the probe beam radius, the pulse repetition frequency and the temperature. For all of the experimental conditions, the experimental results and the model agree.

  19. First operation of a wiggler-focused, sheet beam free electron laser amplifier

    International Nuclear Information System (INIS)

    Destler, W.W.; Cheng, S.; Zhang, Z.X.; Antonsen, T.M. Jr.; Granatstein, V.L.; Levush, B.; Rodgers, J.

    1994-01-01

    A wiggler-focused, sheet beam free electron laser (FEL) amplifier utilizing a short-period wiggler magnet has been proposed as a millimeter-wave source for current profile modification and/or electron cyclotron resonance heating of tokamak plasmas. As proposed, such an amplifier would operate at a frequency of approximately 100--200 GHz with an output power of 1--10 MW CW. Electron beam energy would be in the range 500--1000 keV. To test important aspects of this concept, an initial sheet beam FEL amplifier experiment has been performed using a 1 mmx2 cm sheet beam produced by a pulse line accelerator with a pulse duration of 100 ns. The 500--570 keV, 4--18 A sheet beam is propagated through a 56 period uniform wiggler (λ w =9.6 mm) with a peak wiggler amplitude of 2--5 kG. Linear amplification of a 5--10 W, 94 GHz signal injected in the TE 01 rectangular mode is observed. All features of the amplified signal, including pulse shape and duration, are in accordance with the predictions of numerical simulation. Amplified signal gain has been measured as a function of injected beam energy, current, and wiggler field amplitude and is also in good agreement with simulation results. Continuation of this experiment will involve studying nonlinear amplifier operation and adding a section of tapered wiggler

  20. Compact Aberration-Free Relay-Imaging Multi-Pass Layouts for High-Energy Laser Amplifiers

    Directory of Open Access Journals (Sweden)

    Jörg Körner

    2016-11-01

    Full Text Available We present the results from a theoretical investigation of laser beam propagation in relay imaging multi-pass layouts, which recently found application in high-energy laser amplifiers. Using a method based on the well-known ABCD-matrix formalism and proven by ray tracing, it was possible to derive a categorization of such systems. Furthermore, basic rules for the setup of such systems and the compensation for low order aberrations are derived. Due to the introduced generalization and parametrization, the presented results can immediately be applied to any system of the investigated kinds for a wide range of parameters, such as number of round-trips, focal lengths and optics sizes. It is shown that appropriate setups allow a close-to-perfect compensation of defocus caused by a thermal lens and astigmatism caused by non-normal incidence on the imaging optics, as well. Both are important to avoid intensity spikes leading to damages of optics in multi-pass laser amplifiers.

  1. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    A method is described for generating a traveling wave laser pulse of almost unlimited energy content wherein a gain medium is pumped into a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  2. Compact Ultraintense Femtosecond Laser via Raman Amplifier and Compressor in Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, Szymon [Princeton Univ., NJ (United States)

    2016-03-01

    The main objective of this project was to conduct experimental and theoretical research to find conditions leading to higher, than previously obtained efficiency η of transfer the pump energy into the short seed beam in plasma of Stimulated Raman Back-Scattering (SRBS). We have demonstrated very large amplification and compression in our earlier SRBS plasma. However, the efficiency η was much too low to reach very high intensity of the output beam in the focal spot. Recently, by solving a very difficult technical SRBS’ problem, namely, the creation of very reproducible and much larger diameter plasma channels than in our earlier research, we propose a new approach to obtain higher efficiency η. The crucial new result was a very reproducible, low noise amplified seed in the larger diameter of the plasma channel leading to the higher efficiency. Using this new setup and very encouraging results about increase efficiency continuing this approach in the future the efficiency is expect to reach the range of η ≈15 - 20 % required to develop practical SRBS plasma laser. Intellectual Merit: The model for the present project was created by our earlier SRBS experiments. The main objective of those experiments was to amplify and compress the seed pulses in a plasma . The experiments demonstrated an unprecedented large pulse intensity amplification of 20,000 in system of 2-passes in ~2mm long plasma, and the seed pulse compression from 550fsec down to ~50fsec. The pump and seed beams in the present project have diameters of ~0.2–0.25mm each, propagating in ~0.35 - 0.45mm diameter and ~2-2.5mm long plasma channels (optimal length for our SRBS experiment) with input pump and seed intensities of 2x1014 and 3x1013 W/cm2, respectively. Such an SRBS system design was “prescribed” by computer simulations, which predict elimination of the SRBS “ saturation” for a such relatively short plasma channel. Plasma channels has been created by combining shorter (200psec) and

  3. Modeling the energy deposition in the Aurora KrF laser amplifier chain

    International Nuclear Information System (INIS)

    Comly, J.C.; Czuchlewski, S.J.; Greene, D.P.; Hanson, D.E.; Krohn, B.J.; McCown, A.W.

    1988-01-01

    Monte Carlo calculations model the energy depositions by highly energetic electron beams into the cavities of the four KrF laser amplifiers in the Aurora chain. Deposited energy density distributions are presented and studied as functions of e-beam energy and gas pressure. Results are useful for analyzing small signal gain (SSG) measurements and optimizing deposition in future experiments. 7 refs., 7 figs., 1 tab

  4. Calculations of the self-amplified spontaneous emission performance of a free-electron laser

    International Nuclear Information System (INIS)

    Dejus, R. J.

    1999-01-01

    The linear integral equation based computer code (RON: Roger Oleg Nikolai), which was recently developed at Argonne National Laboratory, was used to calculate the self-amplified spontaneous emission (SASE) performance of the free-electron laser (FEL) being built at Argonne. Signal growth calculations under different conditions are used for estimating tolerances of actual design parameters. The radiation characteristics are discussed, and calculations using an ideal undulator magnetic field and a real measured magnetic field will be compared and discussed

  5. Efficient ASE management in disk laser amplifiers with variable absorbing clads

    Czech Academy of Sciences Publication Activity Database

    Slezák, Ondřej; Lucianetti, Antonio; Mocek, Tomáš

    2014-01-01

    Roč. 50, č. 12 (2014), s. 1052-1060 ISSN 0018-9197 R&D Projects: GA MŠk ED2.1.00/01.0027; GA MŠk EE2.3.20.0143 Grant - others:HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : amplifiers * laser * absorbing * Yb:YAG * multi slab Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.887, year: 2014

  6. Construction of an optical semiconductor amplifier starting from a Fabry-Perot semiconductor laser

    International Nuclear Information System (INIS)

    Garcia, E.; Soto, H.; Marquez, H.; Valles V, N.

    2000-01-01

    A methodology to convert a semiconductor laser Fabry-Perot (SL-FP) in a semiconductor optical amplifier (SOA) is presented. In order to suppress the cavity resonant an optical thin film coating was deposited on the facets of the SL-FP. The experiment was carried out putting on service a new monitoring technique that consist in the observation of the laser power spectrum during the antireflection coatings deposition. This allows to determine the moment were the facets reflectivity is minimum. The SOA obtained was characterized for different polarization currents. (Author)

  7. Beam quality management by periodic reproduction of wavefront aberrations in end-pumped Nd:YVO4 laser amplifiers.

    Science.gov (United States)

    Liu, Bin; Liu, Chong; Shen, Lifeng; Wang, Chunhua; Ye, Zhibin; Liu, Dong; Xiang, Zhen

    2016-04-18

    A method for beam quality management is presented in a master oscillator power amplifier (MOPA) using Nd:YVO4 as the gain medium by extra-cavity periodic reproduction of wavefront aberrations. The wavefront aberration evolution of the intra-cavity beams is investigated for both symmetrical and asymmetrical resonators. The wavefront aberration reproduction process is successfully realized outside the cavity in four-stage amplifiers. In the MOPA with a symmetrical oscillator, the laser power increases linearly and the beam quality hardly changes. In the MOPA with an asymmetrical oscillator, the beam quality is deteriorated after the odd-stage amplifier and is improved after the even-stage amplifier. The wavefront aberration reproduction during the extra-cavity beam propagation in the amplifiers is equivalent to that during the intra-cavity propagation. This solution helps to achieve the effective beam quality management in laser amplifier chains.

  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. Thin disk amplifier-based 40 mJ, 1 kHz, picosecond laser at 515 nm

    Czech Academy of Sciences Publication Activity Database

    Novák, Jakub; Green, Jonathan T.; Metzger, T.; Mazanec, Tomáš; Himmel, Bedřich; Horáček, Martin; Hubka, Zbyněk; Boge, Robert; Antipenkov, Roman; Batysta, František; Naylon, Jack A.; Bakule, Pavel; Rus, Bedřich

    2016-01-01

    Roč. 24, č. 6 (2016), s. 5728-5733 ISSN 1094-4087 R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE.2.3.20.0091 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OP VK 1 Laser Sys(XE) CZ.1.07/2.3.00/20.0091 Institutional support: RVO:68378271 Keywords : laser amplifiers * laser s * pulsed * laser s * diode -pumped * laser s * frequency doubled * ultrafast laser s Subject RIV: BH - Optics, Masers, Laser s Impact factor: 3.307, year: 2016

  10. Use of the Lorentz-Boosted Frame Transformation to Simulate Free-Electron Laser Amplifier Physics

    International Nuclear Information System (INIS)

    Fawley, W.M.; Vay, J.-L.

    2008-01-01

    Recently it has been pointed out that numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz boosted frame. A particularly good example is that of short wavelength free-electron lasers (FELs) in which a high energy (E0 (ge) 250 MeV) electron beam interacts with a static magnetic undulator. In the optimal boost frame with Lorentz factor gamma F, the red-shifted FEL radiation and blue shifted undulator have identical wavelengths and the number of required time-steps (presuming the Courant condition applies) decreases by a factor of g2 F for fully electromagnetic simulation. We have adapted the WARP code to apply this method to several FEL problems including coherent spontaneous emission (CSE) from pre-bunched e-beams, and strong exponential gain in a single pass amplifier configuration. We discuss our results and compare with those from the 'standard' FEL simulation approach which adopts the eikonal approximation for propagation of the radiation field

  11. Fast iterative technique for the calculation of frequency dependent gain in excimer laser amplifiers

    International Nuclear Information System (INIS)

    Sze, R.C.

    1991-01-01

    The motivation in initiating these calculations is to allow us to observe the frequency evolution of a laser pulse as it propagates through an amplifier and then through a sequence of amplifiers. The question we seek to answer is what pulse shape do we need to produce out of a front-end oscillator so that after it propagates through the whole Aurora KrF fusion amplifier chain will result in high energy, broad-band laser fields of a given bandwidth that can be focussed onto a fusion target. The propagation of a single frequency source through an amplifier with distributed loss was considered by Rigrod and was significantly expanded by Hunter and Hunter. The latter included amplified spontaneous emission [ASE] considerations both in the direction of and transverse to the coherent field. Analytic solutions that include forward and backward prapagating fields and ASE were derived which were transcendental in nature but allowed for fairly easy computer calculations. Transverse ASE were calculated using the unsaturated gain resulting from longitudinal fields and were used to compare this with the longitudinal field equations. Large computer programs are now available at LANL which include the influence of transverse ASE on the longitudinal fields. However, none of these considerations have worried about the changes in the frequency characteristics of the propagating field or of how each of the frequency field components contributes to the saturation of the gain. The inclusion of full frequency characteristics to the analytic solutions of Hunter and Hunter proved impossible at least for this author and a new calculational technique was developed and is the subject of this talk

  12. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  13. Ring-shaped active mode-locked tunable laser using quantum-dot semiconductor optical amplifier

    Science.gov (United States)

    Zhang, Mingxiao; Wang, Yongjun; Liu, Xinyu

    2018-03-01

    In this paper, a lot of simulations has been done for ring-shaped active mode-locked lasers with quantum-dot semiconductor optical amplifier (QD-SOA). Based on the simulation model of QD-SOA, we discussed about the influence towards mode-locked waveform frequency and pulse caused by QD-SOA maximum mode peak gain, active layer loss coefficient, bias current, incident light pulse, fiber nonlinear coefficient. In the meantime, we also take the tunable performance of the laser into consideration. Results showed QD-SOA a better performance than original semiconductor optical amplifier (SOA) in recovery time, line width, and nonlinear coefficients, which makes it possible to output a locked-mode impulse that has a higher impulse power, narrower impulse width as well as the phase is more easily controlled. After a lot of simulations, this laser can realize a 20GHz better locked-mode output pulse after 200 loops, where the power is above 17.5mW, impulse width is less than 2.7ps, moreover, the tunable wavelength range is between 1540nm-1580nm.

  14. Pulse propagation properties in high-power CO2 laser system for laser fusion

    International Nuclear Information System (INIS)

    Daido, H.; Inoue, M.; Fujita, H.; Matoba, M.; Nakai, S.

    1981-01-01

    The simulation results of nonlinear propagation properties in the CO 2 laser system using a simulation model of the SF 6 saturable absorbers and the CO 2 laser amplifiers agree well with the experimental results. The technical problems of the simultaneous irradiation of the multi-beams to a target are also discussed. (author)

  15. Efficient fiber-laser-pumped Ho:YLF oscillator and amplifier utilizing the transmitted pump power of the oscillator

    CSIR Research Space (South Africa)

    Strauss, HJ

    2009-06-01

    Full Text Available the amplifier. OCIS codes: 140.0140, 140.3070, 140.3480, 140.3580, 140.5680s 1. Introduction High energy 2 �m laser sources are of great interested for applications in remote sensing, medicine and defense. Ho:YLF is an attractive laser material to use since...

  16. Amplified spontaneous emission and laser emission from a high optical-gain medium of dye-doped dendrimer

    International Nuclear Information System (INIS)

    Yokoyama, Shiyoshi; Nakahama, Tatsuo; Mashiko, Shinro

    2005-01-01

    We measured the amplified spontaneous emission and laser emission from high-gain media of laser-dye encapsulated dendrimers. A highly branched poly(amidoamine) (PAMAM-OH) dendrimer formed a guest-host complex with a conventional laser-dye (DCM), resulting in a high optical-gain. Of particular note was the appearance of a laser threshold, above which a super-narrowed laser spectrum was observed, although laser feedback was caused without any mirror cavity devices. The optical feedback was attributed to spatial confinement of the light due to gain guiding under optical excitation. The laser spectrum clearly indicated a resonant laser-mode with a spectrum linewidth of less than 0.1 nm. This order of spectrum narrowing is comparable to that seen in the laser emission from ordinary laser devices

  17. Polymer-Optical-Fiber Lasers and Amplifiers Doped with Organic Dyes

    Directory of Open Access Journals (Sweden)

    Joseba Zubia

    2011-07-01

    Full Text Available Polymer optical fibers (POFs doped with organic dyes can be used to make efficient lasers and amplifiers due to the high gains achievable in short distances. This paper analyzes the peculiarities of light amplification in POFs through some experimental data and a computational model capable of carrying out both power and spectral analyses. We investigate the emission spectral shifts and widths and on the optimum signal wavelength and pump power as functions of the fiber length, the fiber numerical aperture and the radial distribution of the dopant. Analyses for both step-index and graded-index POFs have been done.

  18. Mid-infrared optical parametric oscillator pumped by an amplified random fiber laser

    Science.gov (United States)

    Shang, Yaping; Shen, Meili; Wang, Peng; Li, Xiao; Xu, Xiaojun

    2017-01-01

    Recently, the concept of random fiber lasers has attracted a great deal of attention for its feature to generate incoherent light without a traditional laser resonator, which is free of mode competition and insure the stationary narrow-band continuous modeless spectrum. In this Letter, we reported the first, to the best of our knowledge, optical parametric oscillator (OPO) pumped by an amplified 1070 nm random fiber laser (RFL), in order to generate stationary mid-infrared (mid-IR) laser. The experiment realized a watt-level laser output in the mid-IR range and operated relatively stable. The use of the RFL seed source allowed us to take advantage of its respective stable time-domain characteristics. The beam profile, spectrum and time-domain properties of the signal light were measured to analyze the process of frequency down-conversion process under this new pumping condition. The results suggested that the near-infrared (near-IR) signal light `inherited' good beam performances from the pump light. Those would be benefit for further develop about optical parametric process based on different pumping circumstances.

  19. Laser transmitter system

    International Nuclear Information System (INIS)

    Dye, R.A.

    1975-01-01

    A laser transmitter system is disclosed which utilizes mechanical energy for generating an output pulse. The laser system includes a current developing device such as a piezoelectric crystal which charges a storage device such as a capacitor in response to a mechanical input signal. The capacitor is coupled to a switching device, such as a silicon controlled rectifier (SCR). The switching device is coupled to a laser transmitter such as a GaAs laser diode, which provides an output signal in response to the capacitor being discharged

  20. A Phase-Controlled Optical Parametric Amplifier Pumped by Two Phase-Distorted Laser Beams

    International Nuclear Information System (INIS)

    Hong-Yan, Ren; Lie-Jia, Qian; Peng, Yuan; He-Yuan, Zhu; Dian-Yuan, Fan

    2010-01-01

    We theoretically study the phase characteristic of optical parametric amplification (OPA) or chirped pulse OPA (OPCPA) pumped by two phase-distorted laser beams. In the two-beam-pumped optical parametric amplification (TBOPA), due to spatial walk-off, both of the pump phase distortions will be partly transferred to signal in a single crystal so as to degrade the signal beam-quality, which will be more serious in high-energy OPCPA. An OPA configuration with a walkoff-compensated crystal pair is demonstrated for reducing the signal phase distortion experienced in the first stage and ensuring the signal phase independent of two pump phase distortions through the second crystal, hence maintaining the signal beam-quality. Such a TBOPA is similar to the conventional quantum laser amplifier by means of eliminating its sensitivity to the phase and number of the pump beams

  1. Highly Doped Phosphate Glass Fibers for Compact Lasers and Amplifiers: A Review

    Directory of Open Access Journals (Sweden)

    Nadia Giovanna Boetti

    2017-12-01

    Full Text Available In recent years, the exploitation of compact laser sources and amplifiers in fiber form has found extensive applications in industrial and scientific fields. The fiber format offers compactness, high beam quality through single-mode regime and excellent heat dissipation, thus leading to high laser reliability and long-term stability. The realization of devices based on this technology requires an active medium with high optical gain over a short length to increase efficiency while mitigating nonlinear optical effects. Multicomponent phosphate glasses meet these requirements thanks to the high solubility of rare-earth ions in their glass matrix, alongside with high emission cross-sections, chemical stability and high optical damage threshold. In this paper, we review recent advances in the field thanks to the combination of highly-doped phosphate glasses and innovative fiber drawing techniques. We also present the main performance achievements and outlook both in continuous wave (CW and pulsed mode regimes.

  2. Terahertz lasers and amplifiers based on resonant optical phonon scattering to achieve population inversion

    Science.gov (United States)

    Williams, Benjamin S. (Inventor); Hu, Qing (Inventor)

    2009-01-01

    The present invention provides quantum cascade lasers and amplifier that operate in a frequency range of about 1 Terahertz to about 10 Terahertz. In one aspect, a quantum cascade laser of the invention includes a semiconductor heterostructure that provides a plurality of lasing modules connected in series. Each lasing module includes a plurality of quantum well structure that collectively generate at least an upper lasing state, a lower lasing state, and a relaxation state such that the upper and the lower lasing states are separated by an energy corresponding to an optical frequency in a range of about 1 to about 10 Terahertz. The lower lasing state is selectively depopulated via resonant LO-phonon scattering of electrons into the relaxation state.

  3. Obtaining attosecond x-ray pulses using a self-amplified spontaneous emission free electron laser

    Directory of Open Access Journals (Sweden)

    A. A. Zholents

    2005-05-01

    Full Text Available We describe a technique for the generation of a solitary attosecond x-ray pulse in a free-electron laser (FEL, via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, subfemtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator, this current spike emits a ∼250   attosecond x-ray pulse whose intensity dominates the x-ray emission from the rest of the electron bunch.

  4. lambda-3, Sandia's 100-J HF laser system

    International Nuclear Information System (INIS)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results

  5. Fiber optical parametric amplifiers in optical communication systems

    Science.gov (United States)

    Marhic (†), Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. PMID:25866588

  6. Investigation of pump-to-seed beam matching on output features of Rb and Cs vapor laser amplifiers

    Science.gov (United States)

    Shen, Binglin; Huang, Jinghua; Xu, Xingqi; Xia, Chunsheng; Pan, Bailiang

    2018-05-01

    Taking into account the beam radii of pump light and seed laser along the entire length of the cell and their intensities in the cross section, a physical model with ordinary differential equation methods for alkali vapor amplifiers is established. Applied to the reported optically pumped Rb and diode-pumped Cs vapor amplifiers, the model shows good agreement between the calculated and measured dependence of amplified power on the seed power. A larger width of the spontaneous emission region as compared to the widths of pump absorption and laser emission regions, which will result in very high energy losses, is observed in the cell. Influence of pump and seed beam waists on output performance is calculated, showing that the pump and seed beam should match each other not only in shape but also in size, thus an optimal combination of beam radii is very important for efficient operation of alkali vapor amplifiers.

  7. Cell damage evaluation of mammalian cells in cell manipulation by amplified femtosecond ytterbium laser

    Science.gov (United States)

    Hong, Z.-Y.; Iino, T.; Hagihara, H.; Maeno, T.; Okano, K.; Yasukuni, R.; Hosokawa, Y.

    2018-03-01

    A micrometer-scale explosion with cavitation bubble generation is induced by focusing a femtosecond laser in an aqueous solution. We have proposed to apply the explosion as an impulsive force to manipulate mammalian cells especially in microfluidic chip. Herein, we employed an amplified femtosecond ytterbium laser as an excitation source for the explosion and evaluated cell damage in the manipulation process to clarify the application potential. The damage of C2C12 myoblast cell prepared as a representative mammalian cell was investigated as a function of distance between cell and laser focal point. Although the cell received strong damage on the direct laser irradiation condition, the damage sharply decreased with increasing distance. Since the threshold distance, above which the cell had no damage, was consistent with radius of the cavitation bubble, impact of the cavitation bubble would be a critical factor for the cell damage. The damage had strong nonlinearity in the pulse energy dependence. On the other hand, cell position shift by the impact of the cavitation bubble was almost proportional to the pulse energy. In balance between the cell viability and the cell position shift, we elucidated controllability of the cell manipulation in microfluidic chip.

  8. Powering laser diode systems

    CERN Document Server

    Trestman, Grigoriy A

    2017-01-01

    This Tutorial Text discusses the competent design and skilled use of laser diode drivers (LDDs) and power supplies (PSs) for the electrical components of laser diode systems. It is intended to help power-electronic design engineers during the initial design stages: the choice of the best PS topology, the calculation of parameters and components of the PS circuit, and the computer simulation of the circuit. Readers who use laser diode systems for research, production, and other purposes will also benefit. The book will help readers avoid errors when creating laser systems from ready-made blocks, as well as understand the nature of the "mystical failures" of laser diodes (and possibly prevent them).

  9. Testing methodologies and systems for semiconductor optical amplifiers

    Science.gov (United States)

    Wieckowski, Michael

    Semiconductor optical amplifiers (SOA's) are gaining increased prominence in both optical communication systems and high-speed optical processing systems, due primarily to their unique nonlinear characteristics. This in turn, has raised questions regarding their lifetime performance reliability and has generated a demand for effective testing techniques. This is especially critical for industries utilizing SOA's as components for system-in-package products. It is important to note that very little research to date has been conducted in this area, even though production volume and market demand has continued to increase. In this thesis, the reliability of dilute-mode InP semiconductor optical amplifiers is studied experimentally and theoretically. The aging characteristics of the production level devices are demonstrated and the necessary techniques to accurately characterize them are presented. In addition, this work proposes a new methodology for characterizing the optical performance of these devices using measurements in the electrical domain. It is shown that optical performance degradation, specifically with respect to gain, can be directly qualified through measurements of electrical subthreshold differential resistance. This metric exhibits a linear proportionality to the defect concentration in the active region, and as such, can be used for prescreening devices before employing traditional optical testing methods. A complete theoretical analysis is developed in this work to explain this relationship based upon the device's current-voltage curve and its associated leakage and recombination currents. These results are then extended to realize new techniques for testing semiconductor optical amplifiers and other similarly structured devices. These techniques can be employed after fabrication and during packaged operation through the use of a proposed stand-alone testing system, or using a proposed integrated CMOS self-testing circuit. Both methods are capable

  10. Fiber Based Optical Amplifier for High Energy Laser Pulses Final Report CRADA No. TC02100.0

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cunningham, P. [Boeing Company, Springfield, VA (United States)

    2017-09-06

    This was a collaborative effort between Lawrence Livermore National Security, LLC (formerly The Regents of the University of California)/Lawrence Livermore National Laboratory (LLNL), and The Boeing Company to develop an optical fiber-based laser amplifier capable of producing and sustaining very high-energy, nanosecond-scale optical pulses. The overall technical objective of this CRADA was to research, design, and develop an optical fiber-based amplifier that would meet specific metrics.

  11. Laser Megajoule synchronization system

    International Nuclear Information System (INIS)

    Luttmann, M.; Pastor, J.F; Drouet, V.; Prat, M.; Raimbourg, J.; Adolf, A.

    2011-01-01

    This paper describes the synchronisation system under development on the Laser Megajoule (LMJ) in order to synchronize the laser quads on the target to better than 40 ps rms. Our architecture is based on a Timing System (TS) which delivers trigger signals with jitter down to 15 ps rms coupled with an ultra precision timing system with 5 ps rms jitter. In addition to TS, a sensor placed at the target chamber center measures the arrival times of the 3 omega nano joule laser pulses generated by front end shots. (authors)

  12. Generation of coherent soft x-rays using a single-pass free-electron laser amplifier

    International Nuclear Information System (INIS)

    Wang, T.F.; Goldstein, J.C.; Newnam, B.E.; McVey, B.D.

    1988-01-01

    We consider a single-pass free-electron laser (FEL) amplifier, driven by an rf-linac followed by a damping ring for reduced emittance, for use in generating coherent light in the soft x-ray region. The dependence of the optical gain on electron-beam quality, studied with the three-dimensional FEL simulation code FELEX, is given and related to the expected power of self-amplified spontaneous emission. We discuss issues for the damping ring designed to achieve the required electron beam quality. The idea of a multipass regenerative amplifier is also presented

  13. Fiber laser front end for high energy petawatt laser systems

    International Nuclear Information System (INIS)

    Dawson, J W; Messerly, M J; Phan, H; Mitchell, S; Drobshoff, A; Beach, R J; Siders, C; Lucianetti, A; Crane, J K; Barty, C J

    2006-01-01

    We are developing a fiber laser front end suitable for high energy petawatt laser systems on large glass lasers such as NIF. The front end includes generation of the pulses in a fiber mode-locked oscillator, amplification and pulse cleaning, stretching of the pulses to >3ns, dispersion trimming, timing, fiber transport of the pulses to the main laser bay and amplification of the pulses to an injection energy of 150 (micro)J. We will discuss current status of our work including data from packaged components. Design detail such as how the system addresses pulse contrast, dispersion trimming and pulse width adjustment and impact of B-integral on the pulse amplification will be discussed. A schematic of the fiber laser system we are constructing is shown in figure 1 below. A 40MHz packaged mode-locked fiber oscillator produces ∼1nJ pulses which are phase locked to a 10MHz reference clock. These pulses are down selected to 100kHz and then amplified while still compressed. The amplified compressed pulses are sent through a non-linear polarization rotation based pulse cleaner to remove background amplified spontaneous emission (ASE). The pulses are then stretched by a chirped fiber Bragg grating (CFBG) and then sent through a splitter. The splitter splits the signal into two beams. (From this point we follow only one beam as the other follows an identical path.) The pulses are sent through a pulse tweaker that trims dispersion imbalances between the final large optics compressor and the CFBG. The pulse tweaker also permits the dispersion of the system to be adjusted for the purpose of controlling the final pulse width. Fine scale timing between the two beam lines can also be adjusted in the tweaker. A large mode area photonic crystal single polarization fiber is used to transport the pulses from the master oscillator room to the main laser bay. The pulses are then amplified a two stage fiber amplifier to 150mJ. These pulses are then launched into the main amplifier

  14. CO2 laser-fabricated cladding light strippers for high-power fiber lasers and amplifiers.

    Science.gov (United States)

    Boyd, Keiron; Simakov, Nikita; Hemming, Alexander; Daniel, Jae; Swain, Robert; Mies, Eric; Rees, Simon; Andrew Clarkson, W; Haub, John

    2016-04-10

    We present and characterize a simple CO2 laser processing technique for the fabrication of compact all-glass optical fiber cladding light strippers. We investigate the cladding light loss as a function of radiation angle of incidence and demonstrate devices in a 400 μm diameter fiber with cladding losses of greater than 20 dB for a 7 cm device length. The core losses are also measured giving a loss of cladding light stripping of a 300 W laser diode with minimal heating of the fiber coating and packaging adhesives.

  15. Investigations of a Dual Seeded 1178 nm Raman Laser System

    Science.gov (United States)

    2016-01-14

    was obtained by Raman amplification of a distributed feedback diode laser in a variably strained polarization- maintaining fiber with a record-high...Calia, D.B., “50W CW visible laser source at 589 nm obtained via frequency doubling of three coherently combined narrow-band Raman fiber amplifiers...AFRL-RD-PS- TP-2016-0009 AFRL-RD-PS- TP-2016-0009 INVESTIGATIONS OF A DUAL SEEDED 1178 NM RAMAN LASER SYSTEM Leanne Henry, et al. 14 January

  16. High Average Power, High Energy Short Pulse Fiber Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  17. Start-to-end simulation of self-amplified spontaneous emission free electron lasers from the gun through the undulator

    CERN Document Server

    Borland, M M; Emma, P; Lewellen, J W; Bharadwaj, V K; Fawley, W M; Krejcik, P; Limborg, C; Milton, S V; Nuhn, H D; Soliday, R; Woodley, M

    2002-01-01

    It is widely appreciated that the performance of self-amplified spontaneous emission free-electron lasers (FELs) depends critically on the properties of the drive beam. In view of this, a multi-laboratory collaboration has explored methods and software tools for integrated simulation of the photoinjector, linear accelerator, bunch compressor, and FEL. Rather than create a single code to handle such a system, our goal has been a robust, generic solution wherein pre-existing simulation codes are used sequentially. We have standardized on the use of Argonne National Laboratory's Self-Describing Data Sets file protocol for transfer of data among codes. The simulation codes used are PARMELA, elegant, and GENESIS. We describe the software methodology and its advantages, then provide examples involving Argonne's Low-Energy Undulator Test Line and Stanford Linear Accelerator Center's Linac Coherent Light Source. We also indicate possible future direction of this work.

  18. A high-power millimeter-wave sheet beam free-electron laser amplifier

    International Nuclear Information System (INIS)

    Cheng, S.; Destler, W.W.; Granatstein, V.L.; Antonsen, T.M.; Levush, B.; Rodgers, J.; Zhang, Z.X.

    1996-01-01

    The results of experiments with a short period (9.6 mm) wiggler sheet electron beam (1.0 mm x 2.0 cm) millimeter-wave free electron laser (FEL) amplifier are presented. This FEL amplifier utilized a strong wiggler field for sheet beam confinement in the narrow beam dimension and an offset-pole side-focusing technique for the wide dimension beam confinement. The beam analysis herein includes finite emittance and space-charge effects. High-current beam propagation was achieved as a result of extensive analytical studies and experimental optimization. A design optimization resulted in a low sensitivity to structure errors and beam velocity spread, as well as a low required beam energy. A maximum gain of 24 dB was achieved with a 1-kW injected signal power at 86 GHz, a 450-kV beam voltage, 17-A beam current, 3.8-kG wiggler magnetic field, and a 74-period wiggler length. The maximum gain with a one-watt injected millimeter-wave power was observed to be over 30 dB. The lower gain at higher injection power level indicates that the device has approached saturation. The device was studied over a broad range of experimental parameters. The experimental results have a good agreement with expectations from a one-dimensional simulation code. The successful operation of this device has proven the feasibility of the original concept and demonstrated the advantages of the sheet beam FEL amplifier. The results of the studies will provide guidelines for the future development of sheet beam FEL's and/or other kinds of sheet beam devices. These devices have fusion application

  19. Step-by-step approach to convective cooling of laser disc amplifiers

    International Nuclear Information System (INIS)

    Bourque, R.F.

    1979-04-01

    A step by step approach is presented to the problem of gas cooling of laser glass amplifiers. The basic equations are given for glass conduction, thermal stress, gas convection, and heat exchanger and blower design. An example calculation is then carried out for helium gas at one atmosphere with the gas flow in the direction orthogonal to the optical path. It is found that pumping powers and temperatures are acceptable for this case. Results are also presented for helium in the slant direction and for nitrogen in both directions. Included also are the effects on pumping power of gas temperature rise, gas pressure, flashtube rep rate, and flow channel width. It is found that, based on temperature rise and pumping power, nitrogen is as viable a coolant as helium

  20. Numerical analysis of the performance of an atomic iodine laser amplifier chain

    International Nuclear Information System (INIS)

    Uchiyama, T.; Witte, K.J.

    1981-05-01

    The performance of an atomic iodine laser amplifier chain with output pulse powers close to 2 TW is analyzed by a numerical solution of the Maxwell-Bloch equations. Two subjects are discussed in detail. The first one refers to the pulse compression occurring in the chain as a result of saturation and some related aspects such as damage to components, self-focussing, correlation between the input and output pulse shapes, and the means of pulse shape control. The second deals with various schemes suited for achieving extraction efficiencies of about or larger than 55%. These include the single-pass and double-pass schemes, pulses with two carrier frequencies and a variation of the pulse carrier frequency. In addition, the response of the chain to a variation of those parameters which are most easily subject to change in a routine operation is investigated. (orig.)

  1. High pumping-power fiber combiner for double-cladding fiber lasers and amplifiers

    Science.gov (United States)

    Zheng, Jinkun; Zhao, Wei; Zhao, Baoyin; Li, Zhe; Chang, Chang; Li, Gang; Gao, Qi; Ju, Pei; Gao, Wei; She, Shengfei; Wu, Peng; Hou, Chaoqi; Li, Weinan

    2018-03-01

    A high pumping-power fiber combiner for backward pumping configurations is fabricated and demonstrated by manufacturing process refinement. The pump power handling capability of every pump fiber can extend to 600 W, corresponding to the average pump coupling efficiency of 94.83%. Totally, 2.67-kW output power with the beam quality factor M2 of 1.41 was obtained, using this combiner in the fiber amplifier experimental setup. In addition, the temperature of the splicing region was less than 50.0°C in the designed combiner under the action of circulating cooling water. The experimental results prove that the designed combiner is a promising integrated all-fiber device for multikilowatt continuous-wave fiber laser with excellent beam quality.

  2. Four distributed feedback laser array integrated with multimode-interference and semiconductor optical amplifier

    International Nuclear Information System (INIS)

    Ma Li; Zhu Hong-Liang; Liang Song; Zhao Ling-Juan; Chen Ming-Hua

    2013-01-01

    Monolithic integration of four 1.55-μm-range InGaAsP/InP distributed feedback (DFB) lasers using varied ridge width with a 4 × 1-multimode-interference (MMI) optical combiner and a semiconductor optical amplifier (SOA) is demonstrated. The average output power and the threshold current are 1.8 mW and 35 mA, respectively, when the injection current of the SOA is 100 mA, with a side mode suppression ratio (SMSR) exceeding 40 dB. The four channels have a 1-nm average channel spacing and can operate separately or simultaneously. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  3. Operating Regime for a Backward Raman Laser Amplifier in Preformed Plasma

    International Nuclear Information System (INIS)

    Clark, Daniel S.; Fisch, Nathaniel J.

    2003-01-01

    A critical issue in the generation of ultra-intense, ultra-short laser pulses by backward Raman scattering in plasma is the stability of the pumping pulse to premature backscatter from thermal fluctuations in the preformed plasma. Malkin et al. [V.M. Malkin, et al., Phys. Rev. Lett. 84 (6):1208-1211, 2000] demonstrated that density gradients may be used to detune the Raman resonance in such a way that backscatter of the pump from thermal noise can be stabilized while useful Raman amplification persists. Here plasma conditions for which the pump is stable to thermal Raman backscatter in a homogeneous plasma and the density gradients necessary to stabilize the pump for other plasma conditions are quantified. Other ancillary constraints on a Raman amplifier are also considered to determine a specific region in the Te-he plane where Raman amplification is feasible. By determining an operability region, the degree of uncertainty in density or temperature tolerable for an experimental Raman amplifier is thus also identified. The fluid code F3D, which includes the effects of thermal fluctuations, is used to verify these analytic estimates

  4. Operating regime for a backward Raman laser amplifier in preformed plasma

    International Nuclear Information System (INIS)

    Clark, Daniel S.; Fisch, Nathaniel J.

    2003-01-01

    A critical issue in the generation of ultraintense, ultrashort laser pulses by backward Raman scattering in plasma is the stability of the pumping pulse to premature backscatter from thermal fluctuations in the preformed plasma. Malkin et al. [Phys. Rev. Lett. 84, 1208 (2000)] demonstrated that density gradients may be used to detune the Raman resonance in such a way that backscatter of the pump from thermal noise can be stabilized while useful Raman amplification persists. Here plasma conditions for which the pump is stable to thermal Raman backscatter in a homogeneous plasma and the density gradients necessary to stabilize the pump for other plasma conditions are quantified. Other ancillary constraints on a Raman amplifier are also considered to determine a specific region in the T e -n e plane where Raman amplification is feasible. By determining an operability region, the degree of uncertainty in density or temperature tolerable for an experimental Raman amplifier is thus also identified. The fluid code F3D [R. L. Berger et al., Phys. Plasmas 5, 4337 (1998)], which includes the effects of thermal fluctuations, is used to verify these analytic estimates

  5. Operating Regime for a Backward Raman Laser Amplifier in Preformed Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Daniel S. Clark; Nathaniel J. Fisch

    2003-02-06

    A critical issue in the generation of ultra-intense, ultra-short laser pulses by backward Raman scattering in plasma is the stability of the pumping pulse to premature backscatter from thermal fluctuations in the preformed plasma. Malkin et al. [V.M. Malkin, et al., Phys. Rev. Lett. 84 (6):1208-1211, 2000] demonstrated that density gradients may be used to detune the Raman resonance in such a way that backscatter of the pump from thermal noise can be stabilized while useful Raman amplification persists. Here plasma conditions for which the pump is stable to thermal Raman backscatter in a homogeneous plasma and the density gradients necessary to stabilize the pump for other plasma conditions are quantified. Other ancillary constraints on a Raman amplifier are also considered to determine a specific region in the Te-he plane where Raman amplification is feasible. By determining an operability region, the degree of uncertainty in density or temperature tolerable for an experimental Raman amplifier is thus also identified. The fluid code F3D, which includes the effects of thermal fluctuations, is used to verify these analytic estimates.

  6. A novel, simple and efficient dye laser with low amplified spontaneous emission background for analytical fluorescence and ionization spectroscopy

    International Nuclear Information System (INIS)

    Matveev, Oleg I.; Omenetto, Nicolo'

    1995-01-01

    A new, simple, compact and efficient, grazing- incidence type of dye laser is suggested which has a low level of Amplified Spontaneous Emission. By using a Coumarin dye (LD 5000) pumped with a 20 mJ XeCl excimer laser, and a diffraction grating with 3000 grooves/mm, an efficiency of 11%, a spectral bandwidth of 0.6 cm -1 and a tuning range from 458 to 517 nm have been obtained

  7. Erbium/ytterbium co-doped double clad fiber amplifier, its applications and effects in fiber optic communication systems

    Science.gov (United States)

    Dua, Puneit

    Increased demand for larger bandwidth and longer inter-amplifiers distances translates to higher power budgets for fiber optic communication systems in order to overcome large splitting losses and achieve acceptable signal-to-noise ratios. Due to their unique design ytterbium sensitized erbium doped, double clad fiber amplifiers; offer significant increase in the output powers that can be obtained. In this thesis we investigate, a one-stage, high power erbium and ytterbium co-doped double clad fiber amplifier (DCFA) with output power of 1.4W, designed and built in our lab. Experimental demonstration and numerical simulation techniques have been used to systematically study the applications of such an amplifier and the effects of incorporating it in various fiber optic communication systems. Amplitude modulated subcarrier multiplexed (AM-SCM) CATV distribution experiment has been performed to verify the feasibility of using this amplifier in an analog/digital communication system. The applications of the amplifier as a Fabry-Perot and ring fiber laser with an all-fiber cavity, a broadband supercontinuum source and for generation of high power, short pulses at 5GHz have been experimentally demonstrated. A variety of observable nonlinear effects occur due to the high intensity of the optical powers confined in micron-sized cores of the fibers, this thesis explores in detail some of these effects caused by using the high power Er/Yb double clad fiber amplifier. A fiber optic based analog/digital CATV system experiences composite second order (CSO) distortion due to the interaction between the gain tilt---the variation of gain with wavelength, of the doped fiber amplifier and the wavelength chirp of the directly modulated semiconductor laser. Gain tilt of the Er/Yb co-doped fiber amplifier has been experimentally measured and its contribution to the CSO of the system calculated. Theoretical analysis of a wavelength division multiplexed system with closely spaced

  8. Feedback stabilization system for pulsed single longitudinal mode tunable lasers

    Science.gov (United States)

    Esherick, Peter; Raymond, Thomas D.

    1991-10-01

    A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

  9. Comparison of three different laser systems for application in dentistry

    Science.gov (United States)

    Mindermann, Anja; Niemz, M. H.; Eisenmann, L.; Loesel, Frieder H.; Bille, Josef F.

    1993-12-01

    Three different laser systems have been investigated according to their possible application in dentistry: a free running and a Q-switched microsecond Ho:YAG laser, a free running microsecond Er:YAG laser and picosecond Nd:YLF laser system consisting of an actively mode locked oscillator and a regenerative amplifier. The experiments focused on the question if lasers can support or maybe replace ordinary drilling machines. For this purpose several cavities were generated with the lasers mentioned above. Their depth and quality were judged by light and electron microscopy. The results of the experiments showed that the picosecond Nd:YLF laser system has advantages compared to other lasers regarding their application in dentistry.

  10. 2 micron femtosecond fiber laser

    Science.gov (United States)

    Liu, Jian; Wan, Peng; Yang, Lihmei

    2014-07-29

    Methods and systems for generating femtosecond fiber laser pulses are disclose, including generating a signal laser pulse from a seed laser oscillator; using a first amplifier stage comprising an input and an output, wherein the signal laser pulse is coupled into the input of the first stage amplifier and the output of the first amplifier stage emits an amplified and stretched signal laser pulse; using an amplifier chain comprising an input and an output, wherein the amplified and stretched signal laser pulse from the output of the first amplifier stage is coupled into the input of the amplifier chain and the output of the amplifier chain emits a further amplified, stretched signal laser pulse. Other embodiments are described and claimed.

  11. Development of AVLIS dye laser system

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Nakayama, Tsuyoshi; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    CVL pumped single mode dye laser was performed. It was found that pressure tuning has some excellent feature in comparison to mechanical tuning in dye laser frequency control. For evaluation of dye laser amplifier, two-dimensional rate equation was proposed. Calculated data by this equation agreed with experimental data in large diameter input dye laser beam condition. (author)

  12. 110 GHz rapid, continous tuning from an optical parametric oscillator pumped by a fiber-amplified DBR diode laser

    NARCIS (Netherlands)

    Lindsay, I.D.; Adhimoolam, B.; Gross, P.; Klein, M.E.; Boller, Klaus J.

    2005-01-01

    A singly-resonant continuous-wave optical parametric oscillator (cw-OPO) pumped by a fiber-amplified diode laser is described. Tuning of the pump source allowed the OPO output to be tuned continuously, without mode-hops, over 110 GHz in 29 ms. Discontinuous pump tuning over 20 nm in the region of

  13. Frequency-swept laser light source at 1050 nm with higher bandwidth due to multiple semiconductor optical amplifiers in series

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Thrane, Lars; Andersen, Peter E.

    2009-01-01

    We report on the development of an all-fiber frequency-swept laser light source in the 1050 nm range based on semiconductor optical amplifiers (SOA) with improved bandwidth due to multiple gain media. It is demonstrated that even two SOAs with nearly equal gain spectra can improve the performance...

  14. Degradation of Side-Mode Suppression Ratio in a DFB Laser Integrated With a Semiconductor Optical Amplifier

    DEFF Research Database (Denmark)

    Champagne, A.; Lestrade, Michel; Camel, Jérôme

    2004-01-01

    The degradation of the side-mode suppression ratio (SMSR) in a monolithically integrated distributed feedback laser and semiconductor optical amplifier (SOA) cavity is investigated. An expression is derived that gives the degradation of the SMSR in the case of a perfectly antireflection-coated SO...

  15. Design and performance of large area monolithic electron guns for the Aurora KrF laser system

    International Nuclear Information System (INIS)

    Kang, M.; Rosocha, L.A.; Romero, V.O.; Van Haaften, F.W.; Brucker, J.P.

    1985-01-01

    Aurora is an inertial confinement fusion laser system using optical angular multiplexing and a chain of four cold cathode electron beam driven KrF laser amplifiers to produce 10 to 20 kJ of optical energy

  16. Optimizing pulse compressibility in completely all-fibered Ytterbium chirped pulse amplifiers for in vivo two photon laser scanning microscopy.

    Science.gov (United States)

    Fernández, A; Grüner-Nielsen, L; Andreana, M; Stadler, M; Kirchberger, S; Sturtzel, C; Distel, M; Zhu, L; Kautek, W; Leitgeb, R; Baltuska, A; Jespersen, K; Verhoef, A

    2017-08-01

    A simple and completely all-fiber Yb chirped pulse amplifier that uses a dispersion matched fiber stretcher and a spliced-on hollow core photonic bandgap fiber compressor is applied in nonlinear optical microscopy. This stretching-compression approach improves compressibility and helps to maximize the fluorescence signal in two-photon laser scanning microscopy as compared with approaches that use standard single mode fibers as stretcher. We also show that in femtosecond all-fiber systems, compensation of higher order dispersion terms is relevant even for pulses with relatively narrow bandwidths for applications relying on nonlinear optical effects. The completely all-fiber system was applied to image green fluorescent beads, a stained lily-of-the-valley root and rat-tail tendon. We also demonstrated in vivo imaging in zebrafish larvae, where we simultaneously measure second harmonic and fluorescence from two-photon excited red-fluorescent protein. Since the pulses are compressed in a fiber, this source is especially suited for upgrading existing laser scanning (confocal) microscopes with multiphoton imaging capabilities in space restricted settings or for incorporation in endoscope-based microscopy.

  17. A low-noise transimpedance amplifier for the detection of "Violin-Mode" resonances in advanced Laser Interferometer Gravitational wave Observatory suspensions

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-11-01

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level "Violin-Mode" (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent "noise-gain peaking" arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations—this output being derived from the difference of the photodiodes' two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m-1(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm.

  18. A low-noise transimpedance amplifier for the detection of “Violin-Mode” resonances in advanced Laser Interferometer Gravitational wave Observatory suspensions

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-01-01

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level “Violin-Mode” (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent “noise-gain peaking” arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations—this output being derived from the difference of the photodiodes’ two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m −1 (rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm

  19. A low-noise transimpedance amplifier for the detection of "Violin-Mode" resonances in Advanced Laser Interferometer Gravitational wave Observatory suspensions.

    Science.gov (United States)

    Lockerbie, N A; Tokmakov, K V

    2014-11-01

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level "Violin-Mode" (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent "noise-gain peaking" arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations-this output being derived from the difference of the photodiodes' two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m(-1)(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm.

  20. Application of 1013 ohm Faraday cup current amplifiers for boron isotopic analyses by solution mode and laser ablation multicollector inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lloyd, Nicholas S; Sadekov, Aleksey Yu; Misra, Sambuddha

    2018-01-15

    Boron isotope ratios (δ 11 B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts. 10 13 ohm amplifier technology has previously been applied to several radiogenic systems, but has thus far not been applied to non-traditional stable isotopes. Here we apply 10 13 ohm amplifier technology for the measurement of boron isotope ratios using solution mode MC-ICP-MS and laser ablation mode (LA-)MC-ICP-MS techniques. Precision is shown for reference materials as well as for low-volume foraminifera samples. The baseline uncertainty for a 0.1 pA 10 B + ion beam is reduced to ohm amplifier technology is demonstrated to offer advantages for the determination of δ 11 B values by both MC-ICP-MS and LA-MC-ICP-MS for small samples of biogenic carbonates, such as foraminifera shells. 10 13 ohm amplifier technology will also be of benefit to other non-traditional stable isotope measurements. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Final amplifier design and mercury

    International Nuclear Information System (INIS)

    Rose, E.A.; Hanson, D.E.

    1991-01-01

    The final amplifier for the Mercury KrF excimer facility is being designed. The design exercise involves extensive modeling to predict amplifier performance. Models of the pulsed-power system, including a Child-Langmuir diode with closure, electron-beam energy deposition, KrF laser kinetics, amplified spontaneous emission (ASE), a time-dependent laser extraction in the presence of ASE are presented as a design package. The design exercise indicates that the energy objective of Phase I -- 100 joules -- will be met

  2. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.; Hammer, J.

    1988-01-01

    The development progress during the reporting period 1988 of the laser surveillance system of spent fuel pools is summarized. The present engineered system comes close to a final version for field application as all technical questions have been solved in 1988. 14 figs., 1 tab. (Author)

  3. Performance of the Aurora KrF ICF laser system

    International Nuclear Information System (INIS)

    Jones, J.E.; Czuchlewski, S.J.; Turner, T.P.; Watt, R.G.; Thomas, S.J.; Netz, D.A.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    Because short wavelength lasers are attractive for inertial confinement fusion (ICF), the Department of Energy is sponsoring work at Los Alamos National Laboratory in krypton-fluoride (KrF) laser technology. Aurora is a short-pulse, high-power, KrF laser system. It serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems for short wavelength ICF research. The system employs optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers. The 1 to 5 ns pulse of the Aurora front end is split into 96 beams which are angularly and temporally multiplexed to produce a 480 ns pulse train for amplification by four KrF laser amplifiers. In the present system configuration half (48) of the amplified pulses are demultiplexed using different optical path lengths and delivered simultaneously to target. This paper discusses how the Aurora laser system has entered the initial operational phase by delivering pulse energies of greater than one kilojoule to target

  4. Studies of high repetition rate laser-produced plasma soft-X-ray amplifiers; Etudes d'amplificateurs plasma laser a haute cadence dans le domaine X-UV et applications

    Energy Technology Data Exchange (ETDEWEB)

    Cassou, K

    2006-12-15

    The progress made as well on the Ti:Sa laser system, as in the control and the knowledge of laser produced X-UV sources allowed the construction of a X-UV laser station dedicated to the applications. My thesis work falls under the development of this station and more particularly on the characterization of a X-UV laser plasma amplifier. The experimental study relates to the coupling improvement of the pump infra-red laser with plasma within the framework of the transient collisional X-UV laser generation. These X-UV lasers are generated in a plasma formed by the interaction of a solid target and a laser pulse of approximately 500 ps duration, followed by a second infra-red laser pulse known as of pump (about 5 ps) impinging on the target in grazing incidence. For the first time, a complete parametric study was undertaken on the influence of the grazing angle on the pumping of the amplifying medium. One of the results was to reach very high peak brightness about 10{sup 28} ph/s/mm{sup 2}/mrad{sup 2}/(0.1%bandwidth), which compares well with the free-electron laser brightness. Moreover, we modified then used a new two-dimensional hydrodynamic code with adaptive mesh refinement in order to understand the influence of the space-time properties of the infra-red laser on the formation and the evolution of the amplifying plasma. Our modeling highlighted the interest to use a super Gaussian transverse profile for the line focus leading to an increase in a factor two of the gain region size and a reduction of the electron density gradient by three orders of magnitude. These improvements should strongly increase the energy contained in X-UV laser beam. We thus used X-UV laser to study the appearance of transient defects produced by a laser IR on a beam-splitter rear side. We also began research on the mechanisms of DNA damage induced by a very intense X-UV radiation. (author)

  5. Relay telescope including baffle, and high power laser amplifier utilizing the same

    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.

  6. Power amplifier circuits for functional electrical stimulation systems

    Directory of Open Access Journals (Sweden)

    Delmar Carvalho de Souza

    Full Text Available Abstract Introduction: Functional electrical stimulation (FES is a technique that has been successfully employed in rehabilitation treatment to mitigate problems after spinal cord injury (SCI. One of the most relevant modules in a typical FES system is the power or output amplifier stage, which is responsible for the application of voltage or current pulses of proper intensity to the biological tissue, applied noninvasively via electrodes, placed on the skin surface or inside the muscular tissue, closer to the nervous fibers. The goals of this paper are to describe and discuss about the main power output designs usually employed in transcutaneous functional electrical stimulators as well as safety precautions taken to protect patients. Methods A systematic review investigated the circuits of papers published in IEEE Xplore and ScienceDirect databases from 2000 to 2016. The query terms were “((FES or Functional electric stimulator and (circuit or design” with 274 papers retrieved from IEEE Xplore and 29 from ScienceDirect. After the application of exclusion criteria the amount of papers decreased to 9 and 2 from IEEE Xplore and ScienceDirect, respectively. One paper was inserted in the results as a technological contribution to the field. Therefore, 12 papers presented power stage circuits suitable to stimulate great muscles. Discussion The retrieved results presented relevant circuits with different electronic strategies and circuit components. Some of them considered patient safety strategies or aimed to preserve muscle homeostasis such as biphasic current application, which prevents charge accumulation in stimulated tissues as well as circuits that dealt with electrical impedance variation to keep the electrode-tissue interface within an electrochemical safe regime. The investigation revealed a predominance of design strategies using operational amplifiers in power circuits, current outputs, and safety methods to reduce risks of electrical

  7. High Power laser power conditioning system new discharge circuit research

    CERN Document Server

    Li Yi; Peng Han Sheng; Zhou Pei Zhang; Zheng Wan Guo; Guo Lang Fu; Chen Li Hua; Chen De Hui; Lai Gui You; Luan Yong Ping

    2002-01-01

    The new discharge circuit of power conditioning system for high power laser is studied. The theoretical model of the main discharge circuit is established. The pre-ionization circuit is studied in experiment. In addition, the explosion energy of the new large xenon lamp is successfully measured. The conclusion has been applied to 4 x 2 amplifier system

  8. Performance of a MOPA laser system for photocathode research

    NARCIS (Netherlands)

    Mols, R.F.X.A.M.; Mols, R.F.X.A.M.; Ernst, G.J.

    1994-01-01

    A Nd:YLF laser system with frequency doubled output is described. Several aspects concerning energy and stability of the pulses will be discussed. The system consists of a CW mode locked Nd:YLF oscillator and two double pass amplifiers having a total small signal gain of about a million which means

  9. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.

    1991-09-01

    Laser Surveillance System (LASSY) is a beam of laser light which scans a plane above the water or under-water in a spent-fuel pond. The system can detect different objects and estimates its coordinates and distance as well. LASSY can operate in stand-alone configuration or in combination with a video surveillance to trigger signal to a videorecorder. The recorded information on LASSY computer's disk comprises date, time, start and stop angle of detected alarm, the size of the disturbance indicated in number of deviated points and some other information. The information given by the laser system cannot be fully substituted by TV camera pictures since the scanning beam creates a horizontal surveillance plan. The engineered prototype laser system long-term field test has been carried out in Soluggia (Italy) and has shown its feasibility and reliability under the conditions of real spent fuel storage pond. The verification of the alarm table on the LASSY computer with the recorded video pictures of TV surveillance system confirmed that all alarm situations have been detected. 5 refs

  10. Laser radiation in active amplifying media treated as a transport problem - Transfer equation derived and exactly solved

    Science.gov (United States)

    Gupta, S. R. D.; Gupta, Santanu D.

    1991-10-01

    The flow of laser radiation in a plane-parallel cylindrical slab of active amplifying medium with axial symmetry is treated as a problem in radiative transfer. The appropriate one-dimensional transfer equation describing the transfer of laser radiation has been derived by an appeal to Einstein's A, B coefficients (describing the processes of stimulated line absorption, spontaneous line emission, and stimulated line emission sustained by population inversion in the medium) and considering the 'rate equations' to completely establish the rational of the transfer equation obtained. The equation is then exactly solved and the angular distribution of the emergent laser beam intensity is obtained; its numerically computed values are given in tables and plotted in graphs showing the nature of peaks of the emerging laser beam intensity about the axis of the laser cylinder.

  11. Coherent laser vision system

    International Nuclear Information System (INIS)

    Sebastion, R.L.

    1995-01-01

    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

  12. 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.

  13. On the power amplifier nonlinearity in MIMO transmit beamforming systems

    KAUST Repository

    Qi, Jian

    2012-03-01

    In this paper, single-carrier multiple-input multiple-output (MIMO) transmit beamforming (TB) systems in the presence of high-power amplifier (HPA) nonlinearity are investigated. Specifically, due to the suboptimality of the conventional maximal ratio transmission/maximal ratio combining (MRT/MRC) under HPA nonlinearity, we propose the optimal TB scheme with the optimal beamforming weight vector and combining vector, for MIMO systems with nonlinear HPAs. Moreover, an alternative suboptimal but much simpler TB scheme, namely, quantized equal gain transmission (QEGT), is proposed. The latter profits from the property that the elements of the beamforming weight vector have the same constant modulus. The performance of the proposed optimal TB scheme and QEGT/MRC technique in the presence of the HPA nonlinearity is evaluated in terms of the average symbol error probability and mutual information with the Gaussian input, considering the transmission over uncorrelated quasi-static frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects on the performance of several system parameters, namely, the HPA parameters, numbers of antennas, quadrature amplitude modulation modulation order, number of pilot symbols, and cardinality of the beamforming weight vector codebook for QEGT. © 2012 IEEE.

  14. On the power amplifier nonlinearity in MIMO transmit beamforming systems

    KAUST Repository

    Qi, Jian; Aissa, Sonia

    2012-01-01

    In this paper, single-carrier multiple-input multiple-output (MIMO) transmit beamforming (TB) systems in the presence of high-power amplifier (HPA) nonlinearity are investigated. Specifically, due to the suboptimality of the conventional maximal ratio transmission/maximal ratio combining (MRT/MRC) under HPA nonlinearity, we propose the optimal TB scheme with the optimal beamforming weight vector and combining vector, for MIMO systems with nonlinear HPAs. Moreover, an alternative suboptimal but much simpler TB scheme, namely, quantized equal gain transmission (QEGT), is proposed. The latter profits from the property that the elements of the beamforming weight vector have the same constant modulus. The performance of the proposed optimal TB scheme and QEGT/MRC technique in the presence of the HPA nonlinearity is evaluated in terms of the average symbol error probability and mutual information with the Gaussian input, considering the transmission over uncorrelated quasi-static frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects on the performance of several system parameters, namely, the HPA parameters, numbers of antennas, quadrature amplitude modulation modulation order, number of pilot symbols, and cardinality of the beamforming weight vector codebook for QEGT. © 2012 IEEE.

  15. Double-pass tapered amplifier diode laser with an output power of 1 W for an injection power of only 200 μW.

    Science.gov (United States)

    Bolpasi, V; von Klitzing, W

    2010-11-01

    A 1 W tapered amplifier requiring only 200 μW of injection power at 780 nm is presented in this paper. This is achieved by injecting the seeding light into the amplifier from its tapered side and feeding the amplified light back into the small side. The amplified spontaneous emission of the tapered amplifier is suppressed by 75 dB. The double-passed tapered laser, presented here, is extremely stable and reliable. The output beam remains well coupled to the optical fiber for a timescale of months, whereas the injection of the seed light did not require realignment for over a year of daily operation.

  16. Nonlinear thermally induced distortions of a laser beam in a cryogenic disk amplifier

    International Nuclear Information System (INIS)

    Vyatkin, A G; Khazanov, Efim A

    2009-01-01

    Taking into account the temperature dependences of the heat conductivity, the refractive index, and the thermal expansion coefficient, we calculated the temperature, elastic stresses, a thermally induced lens and depolarisation of a beam in a cryogenic disk amplifier (an Yb:YAG disk placed between a copper cylinder and a sapphire disk cooled by liquid nitrogen). When the active element (the thickness is 0.6 mm, the orientation is [001], the atomic concentration of Yb is 10%) is pumped by radiation from a diode laser (the beam diameter is 6 mm), the temperature does not exceed 140 K for the heat release power of 100 W. In this case, elastic stresses in the active element are six times lower than the maximum permissible value. The focal distance of the thermally induced lens is 5.5 m and the depolarisation rate is 0.038% per two passes through the active element. Although the heat conductivity of the active element rapidly decreases with temperature, the thermal load can be increased by 1.5-2 times when the dimensions of the active element remain constant. (active media)

  17. Ultra-stable, diode-pumped Nd-doped glass regenerative amplifier for the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Crane, J.K.; Martinez, M.; Beach, R.J.; Mitchell, S.; Pratt, G.; Christensen, J.J.

    1995-12-01

    We describe a diode laser-pumped Nd:glass regenerative amplifier that amplifies temporally shaped pulses with low distortion, high pulse-to- pulse stability, and high gain. This laser amplifier is a prototype subsystem for the National Ignition Facility (NIF) laser system. 2 refs., 1 fig

  18. Method and system for homogenizing diode laser pump arrays

    Science.gov (United States)

    Bayramian, Andy J

    2013-10-01

    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%.

  19. Development of high-power and high-energy 2 µm bulk solid-state lasers and amplifiers

    CSIR Research Space (South Africa)

    Koen, W

    2016-04-01

    Full Text Available 250 300 350 Pulse Repetition Frequency [Hz] P u l s e E n e r g y [ m J ] 0 1 2 3 4 5 6 7 8 9 10 A v e r a g e P o w e r [ W ] Osc Energy Amp Energy Osc average P Amp average P Figure 8: Output energy of the ring laser and amplifier...

  20. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody

    2008-01-01

    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  1. Efficient Phase Locking of Fiber Amplifiers Using a Low-Cost and High-Damage-Threshold Phase Control System

    International Nuclear Information System (INIS)

    Pu, Zhou; Yan-Xing, Ma; Xiao-Lin, Wang; Hao-Tong, Ma; Xiao-Jun, Xu; Ze-Jin, Liu

    2010-01-01

    We propose a low-cost and high-damage-threshold phase control system that employs a piezoelectric ceramic transducer modulator controlled by a stochastic parallel gradient descent algorithm. Efficient phase locking of two fiber amplifiers is demonstrated. Experimental results show that energy encircled in the target pinhole is increased by a factor of 1.76 and the visibility of the fringe pattern is as high as 90% when the system is in close-loop. The phase control system has potential in phase locking of large-number and high-power fiber laser endeavors. (fundamental areas of phenomenology (including applications))

  2. The automatic test system for the L3 muon drift chamber amplifiers

    International Nuclear Information System (INIS)

    Bove, A.; Caiazzo, L.; Lanzano, S.; Manna, F.; Manto, G.; Parascandolo, L.; Parascandolo, P.; Parmentola, A.; Paternoster, G.

    1987-01-01

    We describe the system we developed to test the linearity of wire chambers amplifiers of the muon spectrometer presently in construction for the L3 experiment at LEP. The system, controlled by an Apple II computer, is capable of localizing both defective components and faults in the printed board. It will be used to perform the large scale quality control of the amplifier cards

  3. A real-time control system architecture for industrial power amplifiers

    NARCIS (Netherlands)

    Qureshi, F.; Spinu, V.; Wijnands, C.G.E.; Lazar, M.

    2013-01-01

    Power amplifiers are a highly important component in a range of industrial applications, such as, servo-drives, magnetic resonance imaging, energy systems, and audio. The control system for power amplifiers should satisfy a range of requirements, e.g., offset free tracking, stability margins, and

  4. PEP Laser Surveying System

    International Nuclear Information System (INIS)

    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

  5. Optically pumped laser systems

    International Nuclear Information System (INIS)

    DeMaria, A.J.; Mack, M.E.

    1975-01-01

    Laser systems which are pumped by an electric discharge formed in a gas are disclosed. The discharge is in the form of a vortex stabilized electric arc which is triggered with an auxiliary energy source. At high enough repetition rates residual ionization between successive pulses contributes to the pulse stabilization. The arc and the gain medium are positioned inside an optical pumping cavity where light from the arc is coupled directly into the gain medium

  6. Oscillator and system development on the VULCAN glass laser system for the plasma beat-wave program

    International Nuclear Information System (INIS)

    Danson, C.N.

    1990-03-01

    This thesis describes the oscillator and system development on the VULCAN glass laser undertaken in support of the RAL Plasma Beat-wave experiments. This program seeks to evaluate advanced particle acceleration schemes for a new generation of machines for fundamental research in high energy physics. The experiments required two synchronised high power laser pulses of slightly different wavelength. These pulses were generated using two different laser media; Nd:YAG and Nd:YLF operating at 1.064 and 1.053 microns respectively. The first oscillator system developed operated with both lasing media housed in the same laser cavity. Problems with the stability of the optical output required the development of a second system which housed the two lasing media in separate cavities. The second aspect of the development work, described in this thesis, was the reconfiguration of the VULCAN glass laser system to amplify the two laser pulses to power levels of 0.5 TW per pulse. The first scheduled experiment required the two pulses to be propagated co-linearly. To amplify the pulses to the high output powers required two amplifying media to be used which preferentially amplify the two lasing wavelengths. For the later experiments the two laser pulses were amplified in separate amplifier chains which required the design of an efficient beam combiner. (author)

  7. Pulse propagation in a two-pass optical amplifier with arbitrary laser beams overlap

    Directory of Open Access Journals (Sweden)

    AH Farahbod

    2011-09-01

    Full Text Available An analytical model for two-pass optical amplifier with arbitrary beams overlap has been developed which generalized the classical theory of Frantz-Nodvik for single pass amplifier. The effect of counterpropagating beams on gain and output energy fluence included in the model. Moreover, the appropriate limiting relations for two special cases of weak input signal and saturation state of the amplifier gain have been derived. The results indicate that for complete beams overlap, the gain and output energy have the least values. The model predictions are consistent with experimental observations and exact analytical model for two-pass amplifier when beam propagation paths are coincided.

  8. A Front End for Multipetawatt Lasers Based on a High-Energy, High-Average-Power Optical Parametric Chirped-Pulse Amplifier

    International Nuclear Information System (INIS)

    Bagnoud, V.

    2004-01-01

    We report on a high-energy, high-average-power optical parametric chirped-pulse amplifier developed as the front end for the OMEGA EP laser. The amplifier provides a gain larger than 109 in two stages leading to a total energy of 400 mJ with a pump-to-signal conversion efficiency higher than 25%

  9. An experimental analysis of the waveguide modes in a high-gain free-electron laser amplifier

    International Nuclear Information System (INIS)

    Anderson, B.R.

    1989-01-01

    The presence, growth, and interaction of transverse waveguide modes in high-gain free-electron laser (FEL) amplifiers has been observed and studied. Using the Electron Laser Facility at Lawrence Livermore National Laboratory, a 3 MeV, 800 A electron beam generated by the Experimental Test Accelerator was injected into a planar wiggler. Power was then extracted and measured in the fundamental (TE 01 ) an higher-order modes (Te 21 and TM 21 ) under various sets of operating conditions. Horizontal focusing through the wiggler was provided by external quadrupole magnets. There was no axial guide field. The input microwave signal for amplification was generated by a 100 kW magnetron operating at 34.6 Ghz. Power measurements were taken for both flat and tapered wigglers, for two sizes of waveguide, and for both flat and tapered wigglers, for two sizes of waveguide, and for both fundamental and higher mode injection. Mode content was determined by sampling the radiated signal at specific points in the radiation patter. For the flat wiggler and with the large waveguide (2.9 cm x 9.8 cm) the power in the higher modes was comparable to power in the fundamental. both exhibited gains greater than 30 dB/m prior to saturation and both reached powers in excess of 80 MW. Choice of injection mode had little effect on the operation of the system. Operation with the smaller guide (WR-229) provided much better mode selectivity. The fundamental mode continued to show optimum gain in excess of 30 dB/m while the higher-mode gain was of order 20 dB/m. As expected, power output increased significantly with the tapered wigglers. The relative mode content depended on the specific taper used

  10. Plasma conditions generated by interaction of a high brightness, prepulse free Raman amplified KrF laser pulse with solid targets

    International Nuclear Information System (INIS)

    Riley, D.; Gizzi, L.A.; Khattak, F.Y.; Mackinnon, A.J.; Viana, S.M.; Willi, O.

    1992-01-01

    A high brightness, Raman amplified KrF laser has been used to irradiate solid targets with 12 ps laser pulses at intensities above 10 15 W/cm 2 without the presence of a preformed plasma caused by low level amplified spontaneous emission prepulse. Time-resolved x-ray spectroscopy of the K-shell emission from aluminum was used to infer electron densities in excess of 10 23 cm -3 at temperatures of several hundred electronvolts

  11. 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.

  12. A low-noise transimpedance amplifier for the detection of “Violin-Mode” resonances in advanced Laser Interferometer Gravitational wave Observatory suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance) Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2014-11-15

    This paper describes the design and performance of an extremely low-noise differential transimpedance amplifier, which takes its two inputs from separate photodiodes. The amplifier was planned to serve as the front-end electronics for a highly sensitive shadow-displacement sensing system, aimed at detecting very low-level “Violin-Mode” (VM) oscillations in 0.4 mm diameter by 600 mm long fused-silica suspension fibres. Four such highly tensioned fibres support the 40 kg test-masses/mirrors of the Advanced Laser Interferometer Gravitational wave Observatory interferometers. This novel design of amplifier incorporates features which prevent “noise-gain peaking” arising from large area photodiode (and cable) capacitances, and which also usefully separate the DC and AC photocurrents coming from the photodiodes. In consequence, the differential amplifier was able to generate straightforwardly two DC outputs, one per photodiode, as well as a single high-gain output for monitoring the VM oscillations—this output being derived from the difference of the photodiodes’ two, naturally anti-phase, AC photocurrents. Following a displacement calibration, the amplifier's final VM signal output was found to have an AC displacement responsivity at 500 Hz of (9.43 ± 1.20) MV(rms) m{sup −1}(rms), and, therefore, a shot-noise limited sensitivity to such AC shadow- (i.e., fibre-) displacements of (69 ± 13) picometres/√Hz at this frequency, over a measuring span of ±0.1 mm.

  13. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    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.

  14. Prepulse and amplified spontaneous emission effects on the interaction of a petawatt class laser with thin solid targets

    Energy Technology Data Exchange (ETDEWEB)

    Esirkepov, Timur Zh. [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Koga, James K., E-mail: koga.james@jaea.go.jp [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Sunahara, Atsushi [Institute for Laser Technology, 2-6 Yamadaoka Suita, Osaka 565-0871 (Japan); Morita, Toshimasa; Nishikino, Masaharu [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Kageyama, Kei [Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Nagatomo, Hideo; Nishihara, Katsunobu [Institute of Laser Engineering, 2-6 Yamadaoka Suita, Osaka 565-0871 (Japan); Sagisaka, Akito; Kotaki, Hideyuki; Nakamura, Tatsufumi; Fukuda, Yuji; Okada, Hajime; Pirozhkov, Alexander S.; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Kondo, Kiminori; Kando, Masaki [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Bulanov, Sergei V. [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); A.M. Prokhorov Institute of General Physics of RAS, Vavilova st. 38, Moscow 117942 (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation)

    2014-05-01

    When a finite contrast petawatt laser pulse irradiates a micron-thick foil, a prepulse (including amplified spontaneous emission) creates a preplasma, where an ultrashort relativistically strong portion of the laser pulse (the main pulse) acquires higher intensity due to relativistic self-focusing and undergoes fast depletion transferring energy to fast electrons. If the preplasma thickness is optimal, the main pulse can reach the target accelerating fast ions more efficiently than an ideal, infinite contrast, laser pulse. A simple analytical model of a target with preplasma formation is developed and the radiation pressure dominant acceleration of ions in this target is predicted. The preplasma formation by a nanosecond prepulse is analyzed with dissipative hydrodynamic simulations. The main pulse interaction with the preplasma is studied with multi-parametric particle-in-cell simulations. The optimal conditions for hundreds of MeV ion acceleration are found with accompanying effects important for diagnostics, including high-order harmonics generation.

  15. Evolution of shiva laser alignment systems

    International Nuclear Information System (INIS)

    Boyd, R.D.

    1980-07-01

    The Shiva oscillator pulse is preamplified and divided into twenty beams. Each beam is then amplified, spatially filtered, directed, and focused onto a target a few hundred micrometers in size producing optical intensities up to 10 16 W/cm 2 . The laser was designed and built with three automatic alignment systems: the oscillator alignment system, which aligns each of the laser's three oscillators to a reference beamline; the chain input pointing system, which points each beam into its respective chain; and the chain output pointing, focusing and centering system which points, centers and focuses the beam onto the target. Recently the alignment of the laser's one hundred twenty spatial filter pinholes was also automated. This system uses digitized video images of back-illuminated pinholes and computer analysis to determine current positions. The offset of each current position from a desired center point is then translated into stepper motor commands and the pinhole is moved the proper distance. While motors for one pinhole are moving, the system can digitize, analyze, and send commands to other motors, allowing the system to efficiently align several pinholes in parallel

  16. Bias-Voltage Stabilizer for HVHF Amplifiers in VHF Pulse-Echo Measurement Systems.

    Science.gov (United States)

    Choi, Hojong; Park, Chulwoo; Kim, Jungsuk; Jung, Hayong

    2017-10-23

    The impact of high-voltage-high-frequency (HVHF) amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz) ultrasound transducers than with low-frequency (LF, ≤15 MHz) ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC voltages over a wide input range, thus reducing the harmonic-distortion components of the echo signals in VHF pulse-echo measurement systems. To confirm the feasibility of the bias-voltage stabilizer, we measured and compared the deviations in the gain of the HVHF amplifier with and without a bias-voltage stabilizer. Between -13 and 26 dBm, the measured gain deviations of a HVHF amplifier with a bias-voltage stabilizer are less than that of an amplifier without a bias-voltage stabilizer. In order to confirm the feasibility of the bias-voltage stabilizer, we compared the pulse-echo responses of the amplifiers, which are typically used for the evaluation of transducers or electronic components used in pulse-echo measurement systems. From the responses, we observed that the amplitudes of the echo signals of a VHF transducer triggered by the HVHF amplifier with a bias-voltage stabilizer were higher than those of the transducer triggered by the HVHF amplifier alone. The second, third, and fourth harmonic-distortion components of the HVHF amplifier with the bias-voltage stabilizer were also lower than those of the HVHF amplifier alone. Hence, the proposed scheme is a promising method for stabilizing the bias voltage of an HVHF amplifier, and improving the echo-signal quality of VHF transducers.

  17. Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

    International Nuclear Information System (INIS)

    Monsler, M.J.

    1977-01-01

    The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed

  18. Development of laser diode-pumped high average power solid-state laser for the pumping of Ti:sapphire CPA system

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Yoichiro; Tei, Kazuyoku; Kato, Masaaki; Niwa, Yoshito; Harayama, Sayaka; Oba, Masaki; Matoba, Tohru; Arisawa, Takashi; Takuma, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Laser diode pumped all solid state, high repetition frequency (PRF) and high energy Nd:YAG laser using zigzag slab crystals has been developed for the pumping source of Ti:sapphire CPA system. The pumping laser installs two main amplifiers which compose ring type amplifier configuration. The maximum amplification gain of the amplifier system is 140 and the condition of saturated amplification is achieved with this high gain. The average power of fundamental laser radiation is 250 W at the PRF of 200 Hz and the pulse duration is around 20 ns. The average power of second harmonic is 105 W at the PRF of 170 Hz and the pulse duration is about 16 ns. The beam profile of the second harmonic is near top hat and will be suitable for the pumping of Ti:sapphire laser crystal. The wall plug efficiency of the laser is 2.0 %. (author)

  19. Aurora multikilojoule KrF laser system prototype for inertial confinement fusion

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Hanlon, J.A.; Mc Leod, J.; Kang, M.; Kortegaard, B.L.; Burrows, M.D.; Bowling, P.S.

    1987-01-01

    Aurora is the Los Alamos National Laboratory short-pulse, high-power, KrF laser system. It serves as an end-to-end technology demonstration for large-scale ultraviolet laser systems of interest for short wavelength, inertial confinement fusion (ICF) investigations. The systems is a prototype for using optical angular multiplexing and serial amplification by large electron-beam-driven KrF laser amplifiers to deliver stacked, 248-nm, 5-ns duration multikilojoule laser pulses to ICF targets using an --1-km-long optical beam path. The entire Aurora KrF laser system is described and the design features of the following major system components are summarized: front-end lasers, amplifier train, multiplexer, optical relay train, demultiplexer, target irradiation apparatus, and alignment and controls systems

  20. Laser engineering of microbial systems

    Science.gov (United States)

    Yusupov, V. I.; Gorlenko, M. V.; Cheptsov, V. S.; Minaev, N. V.; Churbanova, E. S.; Zhigarkov, V. S.; Chutko, E. A.; Evlashin, S. A.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-06-01

    A technology of laser engineering of microbial systems (LEMS) based on the method of laser-induced transfer of heterogeneous mixtures containing microorganisms (laser bioprinting) is described. This technology involves laser printing of soil microparticles by focusing near-infrared laser pulses on a specially prepared gel/soil mixture spread onto a gold-coated glass plate. The optimal range of laser energies from the point of view of the formation of stable jets and droplets with minimal negative impact on living systems of giant accelerations, laser pulse irradiation, and Au nanoparticles was found. Microsamples of soil were printed on glucose-peptone-yeast agar plates to estimate the LEMS process influence on structural and morphological microbial diversity. The obtained results were compared with traditionally treated soil samples. It was shown that LEMS technology allows significantly increasing the biodiversity of printed organisms and is effective for isolating rare or unculturable microorganisms.

  1. Laser cleaner development for decontamination of the primary water cooling system at nuclear power plants

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    2010-01-01

    We recently have performed the feasibility studies to develop laser cleaners utilizing several laser oscillator and amplifier systems like femto-second free-electron lasers, water-jet guided lasers, Q-switched YAG lasers, fiber lasers. Whenever we used to clean the RI-contaminated surface using the lasers, we should focus enough laser power in the surface to evaporate instantly without melting. Therefore, as the contaminated being deeply located into the surface could be removed using any one set of the lasers, we found that every trial of laser cleaning could remove very well the RI contamination being located deeply. Our cold decontamination test using a model sample being Cobalt plated successfully has been performed to show a very high decontamination factor. In order to develop an usable laser cleaner, we plan to develop the prototype laser cleaner next year. (author)

  2. Implementation of amplifiers, control and safety subsystems of radiofrequency system of VINCY Cyclotron

    International Nuclear Information System (INIS)

    Drndarevic, V.; Obradovic, M.; Samardic, B.; Djuric, B.; Bojovic, B.; Trajic, M.I.; Golubicic, Z.; Smiljakovic, V.

    1996-01-01

    Concept and design of power amplifiers, control subsystem and safety subsystems for the RF system of the VINCY cyclotron are described. The power amplifiers subsystem consists of two amplifiers of 30 kW nominal power that operate in class B or class C. High stability of voltage amplitude of 5x10 -4 and phase stability between two resonators better than ± 0.5 0 in the range from 16.5 to 31 MHz is being providing by RF control subsystem. Autonomous safety system serves to protect staff from high voltage and to protect equipment from damage. (author)

  3. Design of Amplifier Circuit for the HT-7 Tokamak Thomson Scattering System

    International Nuclear Information System (INIS)

    Shi Lingwei; Ling Bili; Zhao Junyu; Yang Li; Zang Qing; Hu Qingsheng; Jia Yanqing

    2008-01-01

    Thomson scattering diagnostic is important for measuring electron temperature and density profiles. To improve the signal-to-noise ratio, a silicon avalanche photodiode (APD) with high quantum efficiency, high sensitivity, and high gain up to 100 was adopted to measure the Thomson scattering spectrum. A preamplifier, which has low noise, high bandwidth, and high sensitivity, was designed with suitable transimpedance. Using AD8367 as the post-amplifier, good performance of the APD readout electronics have been obtained. A discussion is presented on the performance of the amplifier using a laser diode to simulate the Thomson scattering light. The test results indicate that the designed circuit has a high amplifying factor and fast rising edge. So reduction of the integral gate of the CAMAC ADC converter can improve the signal-to-noise ratio. (brief communication and research note)

  4. The copper-pumped dye laser system at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Hackel, R.P.; Warner, B.E.

    1993-01-01

    The Lawrence Livermore National Laboratory's (LLNL) Atomic Vapor Laser Isotope Separation (AVLIS) Program has developed a high-average-power, pulsed, tunable, visible laser system. Testing of this hardware is in progress at industrial scale. The LLNL copper-dye laser system is prototypical of a basic module of a uranium-AVLIS plant. The laser demonstration facility (LDF) system consists of copper vapor lasers arranged in oscillator-amplifier chains providing optical pump power to dye-laser master-oscillator-power-amplifier chains. This system is capable of thousands of watts (average) tunable between 550 and 650 mm. The copper laser system at LLNL consists of 12 chains operating continuously. The copper lasers operate at nominally 4.4 kHz, with 50 ns pulse widths and produce 20 W at near the diffraction limit from oscillators and >250 W from each amplifier. Chains consist of an oscillator and three amplifiers and produce >750 W average, with availabilities >95% (i.e., >8,300 h/y). The total copper laser system power averages ∼9,000 W and has operated at over 10,000 W for extended intervals. The 12 copper laser beams are multiplexed and delivered to the dye laser system where they pump multiple dye laser chains. Each dye chain consists of a master oscillator and three or four power amplifiers. The master oscillator operates at nominally 100 mW with a 50 MHz single mode bandwidth. Amplifiers are designed to efficiently amplify the dye beam with low ASE content and high optical quality. Sustained dye chain powers are up to 1,400 W with dye conversion efficiency >50%, ASE content <5%, and wavefront quality correctable to <λ/10 RMS, using deformable mirrors. Since the timing of the copper laser chains can be offset, the dye laser system is capable of repetition rates which are multiples of 4.4 kHz, up to 26 kHz, limited by the dye pumping system. Development of plant-scale copper and dye laser hardware is progressing in off-line facilities

  5. High rate amplifier-digitizer system for liquid argon calorimeters

    International Nuclear Information System (INIS)

    Droege, T.F.; Lobkowicz, F.; Fukushima, Y.

    1978-01-01

    A low-cost charge amplifier for a liquid argon photon detector and a new method for pulse height analysis are described. This scheme is suitable for high-energy photon detection with high counting rate. Samples of preamplifer output are taken just before and just after the arrival of the charge from the detector. The difference of these samples provides a stable pedestal and rejects low frequency noise. Short two-pulse resolving time (approximately equal to 200ns) is achieved. 6 refs

  6. Opportunistic Energy-Aware Amplify-and-Forward Cooperative Systems with Imperfect CSI

    KAUST Repository

    Amin, Osama; Bedeer, Ebrahim; Ahmed, Mohamed Hossam; Dobre, Octavia; Alouini, Mohamed-Slim

    2015-01-01

    an energyefficient relay assisted communication system based on estimated channel state information (CSI). It employs amplify-andforward relaying and switches between different communication schemes, which are known as direct-transmission, two-hop and cooperative

  7. Method and system for compact efficient laser architecture

    Science.gov (United States)

    Bayramian, Andrew James; Erlandson, Alvin Charles; Manes, Kenneth Rene; Spaeth, Mary Louis; Caird, John Allyn; Deri, Robert J.

    2015-09-15

    A laser amplifier module having an enclosure includes an input window, a mirror optically coupled to the input window and disposed in a first plane, and a first amplifier head disposed along an optical amplification path adjacent a first end of the enclosure. The laser amplifier module also includes a second amplifier head disposed along the optical amplification path adjacent a second end of the enclosure and a cavity mirror disposed along the optical amplification path.

  8. Construction of a large laser fusion system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1977-01-01

    Construction of a large laser fusion machine is nearing completion at the Lawrence Livermore Laboratory (LLL). Shiva, a 20-terawatt neodymium doped glass system, will be complete in early 1978. This system will have the high power needed to demonstrate significant thermonuclear burn. Shiva will irradiate a microscopic D-T pellet with 20 separate laser beams arriving simultaneously at the target. This requires precise alignment, and stability to maintain alignment. Hardware for the 20 laser chains is composed of 140 amplifiers, 100 spatial filters, 80 isolation stages, 40 large turning mirrors, and a front-end splitter system of over 100 parts. These are mounted on a high stability, three dimensional spaceframe which serves as an optical bench. The mechanical design effort, spanning approximately 3 years, followed a classic engineering evolution. The conceptual design phase led directly to system optimization through cost and technical tradeoffs. Additional manpower was then required for detailed design and specification of hardware and fabrication. Design of long-lead items was started early in order to initiate fabrication and assembly while the rest of the design was completed. All components were ready for assembly and construction as fiscal priorities and schedules permitted

  9. Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

    OpenAIRE

    Zbrzeski, Adeline; Lewis, Noëlle; Rummens, Francois; Jung, Ranu; N'Kaoua, Gilles; Benazzouz, Abdelhamid; Renaud, Sylvie

    2013-01-01

    Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-g...

  10. Experimental characteristics of a high-gain free-electron laser amplifier operating at 8-mm and 2-mm wavelengths

    International Nuclear Information System (INIS)

    Throop, A.L.; Orzechowski, T.J.; Anderson, B.R.

    1987-01-01

    The Electron Laser Facility (ELF) at the Lawrence Livermore National Laboratory (LLNL) uses a high-current induction linac (3.5 MeV, 1000 A), in conjunction with a pulsed electromagnetic wiggler (4.0 M, 4000 G), to operate a free electron laser (FEL) that produces intense radiation in the microwave regime (2 to 8 mm). ELF is a high-gain, single-pass amplifier, using a commercial microwave source as an oscillator input (200 W-50 kW). Previous experiments at 35 GHz produced exponential gains of 40 dB/m, peak powers exceeding 1 GW, and beam-to-rf conversion efficiencies of 34%. Recent experiments at 140 GHz have demonstrated exponential gains of 22 dB/m, peak powers exceeding 50 MW, and total gains of 65 dB. In this paper, we describe the experimental results at these two frequencies and compare then with the predictions of simulation codes

  11. lambda-3, Sandia's 100-J HF laser system

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results.

  12. Large aperture components for solid state laser fusion systems

    International Nuclear Information System (INIS)

    Simmons, W.W.

    1978-01-01

    Solid state lasers for fusion experiments must reliably deliver maximum power to small (approximately .5 mm) targets from stand-off focal distances of 1 m or more. This requirement places stringent limits upon the optical quality, resistance to damage, and overall performance of the several major components--amplifiers, Faraday isolators, spatial filters--in each amplifier train. Component development centers about achieving (1) highest functional material figure of merit, (2) best optical quality, and (3) maximum resistance to optical damage. Specific examples of the performance of large aperture components will be presented within the context of the Argus and Shiva laser systems, which are presently operational at Lawrence Livermore Laboratory. Shiva comprises twenty amplifiers, each of 20 cm output clear aperture. Terawatt beams from these amplifiers are focused through two opposed, nested clusters of f/6 lenses onto such targets. Design requirements upon the larger aperture Nova laser components, up to 35 cm in clear aperture, will also be discussed; these pose a significant challenge to the optical industry

  13. Gain media edge treatment to suppress amplified spontaneous emission in a high power laser

    Science.gov (United States)

    Hackel, Lloyd A.; Soules, Thomas F.; Fochs, Scott N.; Rotter, Mark D.; Letts, Stephan A.

    2008-12-09

    A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges using a substantially high index bonding elastomer or epoxy to a predetermined electromagnetic absorbing arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.

  14. Electra: Repetitively Pulsed Angularly Multiplexed KrF Laser System Performance

    Science.gov (United States)

    Wolford, Matthew; Myers, Matthew; Giuliani, John; Sethian, John; Burns, Patrick; Hegeler, Frank; Jaynes, Reginald

    2008-11-01

    As in a full size fusion power plant beam line, Electra is a multistage laser amplifier system. The multistage amplifier system consists of a commercial discharge laser and two doubled sided electron beam pumped amplifiers. Angular multiplexing is used in the optical layout to provide pulse length control and to maximize laser extraction from the amplifiers. Two angularly multiplexed beams have extracted 30 J of KrF laser light with an aperture 8 x 10 cm^2, which is sufficient to extract over 500 J from the main amplifier and models agree. The main amplifier of Electra in oscillator mode has demonstrated single shot and rep-rate laser energies exceeding 700 J with 100 ns pulsewidth at 248 nm with an aperture 29 x 29 cm^2. Continuous operation of the KrF electron beam pumped oscillator has lasted for more than 2.5 hours without failure at 1 Hz and 2.5 Hz. The measured intensity and pulse energy for durations greater than thousand shots are consistent at measurable rep-rates of 1 Hz, 2.5 Hz and 5 Hz.

  15. Analysis of dynamic pump-loss controlled gain-locking system for erbium-doped fiber amplifiers

    Czech Academy of Sciences Publication Activity Database

    Karásek, Miroslav; Plaats van der, J.C.

    1998-01-01

    Roč. 10, č. 8 (1998), s. 1171-1173 ISSN 1041-1135 Grant - others:EU COST(XE) OC 241.10 Keywords : optical communication * amplifiers * fibre lasers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.791, year: 1998

  16. Regenerative laser system

    International Nuclear Information System (INIS)

    Biancardi, F.R.; Landerman, A.; Melikian, G.

    1975-01-01

    Regenerative apparatus for exhausting the working medium from the optical cavity of a laser and for supplying preheated diluent to the reaction chamber of a laser is disclosed. In an aftercooler thermal energy is exchanged between the working medium exhausted from the optical cavity and a cryogenic coolant which is subsequently utilized as the motive fluid for an ejector and as a diluent in the production of laser gas. Highly toxic and corrosive gases are condensed out of the working medium as the cryogenic coolant is evaporated and superheated. A preheater transfers additional heat to the diluent before the diluent enters the reaction chamber. (U.S.)

  17. Amplification of picosecond pulse by electron-beam pumped KrF laser amplifiers. Denshi beam reiki KrF laser zofukuki ni yoru piko byo pulse no zofuku

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, I.; Tomie, T.; Owadano, Y.; Yano, M. (Electrotechnical Laboratory, Tsukuba (Japan))

    1991-08-20

    Experiments on the amplification of a picosecond pulse by electron-beam pumped KrF laser amplifiers were carried out for the purpose of its application to the field such as excitation light source for soft X-ray laser which requires large energy besides peak power. The picosecond pulse was amplified by a discharge pumped KrF amplifier and two electron-beam pumped KrF amplifiers(at the middle stage and the final stage). The energy of 4J, which was the largest energy for short pulse excimer laser so far, was obtained by these devices. About 90% of the window area of the final amplifier with 29cm diameter was filled by the input beam, and energy density of the picosecond beam reached 3.9 times saturation energy density. Measured energy of amplified spontaneous emission(ASE) showed good agreement with the theoretically estimated value. Most of ASE was derived from the discharge pumped laser as the first amplifier. As for the focused power density, the power density ratio of the picosecond pulse to ASE was estimated to be as large as 10{sup 5}. 11 refs., 4 figs.

  18. Aberrations and focusability in large solid-state-laser systems

    International Nuclear Information System (INIS)

    Simmons, W.W.

    1981-01-01

    Solid state lasers for fusion experiments must reliably deliver maximum power to small (approximately .5 mm) targets from stand-off focal distances of 1 m or more. This requirement places stringent limits upon the optical quality of the several major components - amplifiers, Faraday isolators, spatial filters - in each amplifier train. Residual static aberrations in optical components are transferred to the beam as it traverses the optical amplifier chain. Although individual components are typically less than lambda/20 for components less than 10 cm clear aperture; and less than lambda/10 for components less than 20 cm clear aperture; the large number of such components in optical series results in a wavefront error that may exceed one wave for modern solid state lasers. For pulse operation, the focal spot is additionally broadened by intensity dependent nonlinearities. Specific examples of the performance of large aperture components will be presented within the context of the Argus and Shiva laser systems, which are presently operational at Lawrence Livermore National Laboratory. Design requirements upon the larger aperture Nova laser components, up to 74 cm in clear aperture, will also be discussed; these pose a significant challenge to the optical industry

  19. 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.

  20. Influence of thermal reduced depolarization on a repetition-frequency laser amplifier and compensation

    Institute of Scientific and Technical Information of China (English)

    Xin-ying Jiang; Xiong-wei Yan; Zhen-guo Wang; Jian-gang Zheng; Ming-zhong Li; Jing-qin Su

    2015-01-01

    Thermal stress can induce birefringence in a laser medium, which can cause depolarization of the laser. The depolarization effect will be very severe in a high-average-power laser. Because the depolarization will make the frequency doubling efficiency decline, it should be compensated. In this paper, the thermal characteristics of two kinds of materials are analyzed in respect of temperature, thermal deformation and thermal stress. The depolarization result from thermal stress was simulated. Depolarization on non-uniform pumping was also simulated, and the compensation method is discussed.

  1. Recent progress on the Los Alamos Aurora ICF [inertial confinement fusion] laser system

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Blair, L.S.

    1987-01-01

    Aurora is the Los Alamos short-pulse, high-power, krypton-fluoride laser system. It serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems for short wavelength inertial confinement fusion (ICF) investigations. The system is designed to employ optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers to deliver stacked, 248-nm, 5-ns duration multikilojoule laser pulses to ICF-relevant targets. This paper presents a summary of the Aurora system and a discussion of the progress achieved in the construction and integration of the laser system. We concentrate on the main features of the following major system components: front-end lasers, amplifier train, multiplexer, optical relay train, demultiplexer, and the associated optical alignment system. During the past year, two major construction and integration tasks have been accomplished. The first task is the demonstration of 96-beam multiplexing and amplified energy extraction, as evidenced by the integrated operation of the front end, the multiplexer (12-fold and 8-fold encoders), the optical relay train, and three electron-beam-driven amplifiers. The second task is the assembly and installation of the demultiplexer optical hardware, which consists of over 300 optical components ranging in size from several centimeters square to over a meter square. 13 refs., 13 figs

  2. Permeabilisation de membranes cellulaires a l'aide d'un laser nanoseconde amplifie par nanoparticules plasmoniques

    Science.gov (United States)

    St-Louis Lalonde, Bastien

    The plasmic membrane of eukaryot cells provides a selective permeability between the cytoplasm and the external environment. It regulates the passage of ions (O2, N 2, K, etc...) and molecules (H2 O, C2H6 O, etc...) by mechanisms like passive diffusion and active transport. In various fields like molecular biology or drug development, it is sometimes needed to bypass this selective permeability to introduce external molecules that are normally impermeable to cell membrane. Examples of external molecules may be DNA plasmid, RNA segment or drugs. We propose a method based on laser amplification by plasmonic nanoparticles to overcome this biological barrier. This non invasive method increases the membrane permeability of a large number of cells in a short time. Optoporation by laser amplified with plasmonic nanoparticles consists of pulsed laser irradiation on cells that have been previously incubated with gold nanoparticles (AuNPs). The laser-AuNPs interactions will create a cavitation bubble which in turn will decrease the membrane permeability by disrupting the bilipid layer arrangement. Molecules in the external medium may then penetrate inside the cells and under the right experimental conditions, the cells will rapidly reseal their membrane and continue living without nefast effects. The feasibility of high throughput optical perforation amplified by plasmonic nanoparticles have been tested with a nanosecond pulsed laser working at 532 nm and 1064 nm. The plasma membrane of cancerous human fibroblast (melanoma wm278) have been successfully perforated while keeping an excellent viability rate. Up to 30% of cells are perforated in which the Lucifer Yellow fluorophore have been incorporated. The viability 2 h after the treatment was evaluated by PI exclusion and the long term vitality was tested by MTT essay. Under optimal conditions at 532 nm, the 2 h viability is 84% and the vitality start at 64% for 2h and reaches 88% after 72 h. With 1064 nm pusles, the 2 h

  3. Pressure-amplified Common Rail System for commercial vehicles; Druckuebersetztes Common-Rail-System fuer Nutzfahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Leonhard, Rolf; Parche, Marcus; Alvarez-Avila, Carlos [Bosch AG, Stuttgart (Germany). Diesel Systems; Krauss, Jost; Rosenau, Bernd [Bosch AG, Stuttgart (Germany). Common-Rail-Systeme

    2009-05-15

    The key to a successful layout of a combustion system for commercial vehicles is in the management of peak torque operation points. For this purpose, Bosch has enhanced its Common Rail System with increasing degrees of freedom - i.e. with flexible rate shaping. A second solenoid valve activates a pressure-amplifier inside the injector, an optimized offset of nozzle needle timing reduces the injection rate by half right at the start of injection, and the formation of nitrogen oxide is reduced considerably. This enables the engine manufacturer to adhere to the emission limits while further reducing fuel consumption and the engine-related effort for the air sytem. (orig.)

  4. The GEO 600 laser system

    CERN Document Server

    Zawischa, I; Danzmann, K; Fallnich, C; Heurs, M; Nagano, S; Quetschke, V; Welling, H; Willke, B

    2002-01-01

    Interferometric gravitational wave detectors require high optical power, single frequency lasers with very good beam quality and high amplitude and frequency stability as well as high long-term reliability as input light source. For GEO 600 a laser system with these properties is realized by a stable planar, longitudinally pumped 12 W Nd:YAG rod laser which is injection-locked to a monolithic 800 mW Nd:YAG non-planar ring oscillator. Frequency control signals from the mode cleaners are fed to the actuators of the non-planar ring oscillator which determines the frequency stability of the system. The system power stabilization acts on the slave laser pump diodes which have the largest influence on the output power. In order to gain more output power, a combined Nd:YAG-Nd:YVO sub 4 system is scaled to more than 22 W.

  5. Z-Beamlet: a multikilojoule, terawatt-class laser system

    International Nuclear Information System (INIS)

    Rambo, Patrick K.; Smith, Ian C.; Porter, John L. Jr.; Hurst, Michael J.; Speas, C. Shane; Adams, Richard G.; Garcia, Antonio J.; Dawson, Ellis; Thurston, Benjamin D.; Wakefield, Colleen; Kellogg, Jeff W.; Slattery, Michael J.; Ives III, Harry C.; Broyles, Robin S.; Caird, John A.; Erlandson, Alvin C.; Murray, James E.; Behrendt, William C.; Neilsen, Norman D.; Narduzzi, Joseph M.

    2005-01-01

    A large-aperture (30-cm) kilojoule-class Nd:glass laser system known as Z-Beamlet has been constructed to perform x-ray radiography of high-energy-density science experiments conducted on the Z facility at Sandia National Laboratories, Albuquerque, New Mexico. The laser, operating with typical pulse durations from 0.3 to 1.5 ns, employs a sequence of successively larger multipass amplifiers to achieve up to 3-kJ energy at 1054 nm. Large-aperture frequency conversion and long-distance beam transport can provide on-target energies of up to 1.5 kJ at 527 nm

  6. Gigashot Optical Laser Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Deri, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-13

    The Gigashot Optical Laser Demonstrator (GOLD) project has demonstrated a novel optical amplifier for high energy pulsed lasers operating at high repetition rates. The amplifier stores enough pump energy to support >10 J of laser output, and employs conduction cooling for thermal management to avoid the need for expensive and bulky high-pressure helium subsystems. A prototype amplifier was fabricated, pumped with diode light at 885 nm, and characterized. Experimental results show that the amplifier provides sufficient small-signal gain and sufficiently low wavefront and birefringence impairments to prove useful in laser systems, at repetition rates up to 60 Hz.

  7. Nova laser alignment control system

    International Nuclear Information System (INIS)

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-01-01

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system

  8. Compressed sensing based joint-compensation of power amplifier's distortions in OFDMA cognitive radio systems

    KAUST Repository

    Ali, Anum Z.

    2013-12-01

    Linearization of user equipment power amplifiers driven by orthogonal frequency division multiplexing signals is addressed in this paper. Particular attention is paid to the power efficient operation of an orthogonal frequency division multiple access cognitive radio system and realization of such a system using compressed sensing. Specifically, precompensated overdriven amplifiers are employed at the mobile terminal. Over-driven amplifiers result in in-band distortions and out of band interference. Out of band interference mostly occupies the spectrum of inactive users, whereas the in-band distortions are mitigated using compressed sensing at the receiver. It is also shown that the performance of the proposed scheme can be further enhanced using multiple measurements of the distortion signal in single-input multi-output systems. Numerical results verify the ability of the proposed setup to improve error vector magnitude, bit error rate, outage capacity and mean squared error. © 2011 IEEE.

  9. Compressed sensing based joint-compensation of power amplifier's distortions in OFDMA cognitive radio systems

    KAUST Repository

    Ali, Anum Z.; Hammi, Oualid; Al-Naffouri, Tareq Y.

    2013-01-01

    Linearization of user equipment power amplifiers driven by orthogonal frequency division multiplexing signals is addressed in this paper. Particular attention is paid to the power efficient operation of an orthogonal frequency division multiple access cognitive radio system and realization of such a system using compressed sensing. Specifically, precompensated overdriven amplifiers are employed at the mobile terminal. Over-driven amplifiers result in in-band distortions and out of band interference. Out of band interference mostly occupies the spectrum of inactive users, whereas the in-band distortions are mitigated using compressed sensing at the receiver. It is also shown that the performance of the proposed scheme can be further enhanced using multiple measurements of the distortion signal in single-input multi-output systems. Numerical results verify the ability of the proposed setup to improve error vector magnitude, bit error rate, outage capacity and mean squared error. © 2011 IEEE.

  10. Requirements and new materials for fusion laser systems

    International Nuclear Information System (INIS)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n 2 ) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978

  11. Requirements and new materials for fusion laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n/sub 2/) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978.

  12. E-Learning System for Design and Construction of Amplifier Using Transistors

    Science.gov (United States)

    Takemura, Atsushi

    2014-01-01

    This paper proposes a novel e-Learning system for the comprehensive understanding of electronic circuits with transistors. The proposed e-Learning system allows users to learn a wide range of topics, encompassing circuit theories, design, construction, and measurement. Given the fact that the amplifiers with transistors are an integral part of…

  13. Colloidal drug delivery system: amplify the ocular delivery.

    Science.gov (United States)

    Ali, Javed; Fazil, Mohd; Qumbar, Mohd; Khan, Nazia; Ali, Asgar

    2016-01-01

    The ocular perceivers are the most voluntarily accessible organs in terms of location in the body, yet drug distribution to these tissues is one of the most intriguing and challenging endeavors and problematic to the pharmaceutical scientist. The most of ocular diseases are treated with topical application of conventional formulation, i.e. solutions, suspensions and ointment. Typically on installation of these conventional formulations, only <5% of the applied dose penetrates the cornea and reaches intraocular tissues, while a major fraction of the instilled dose is wastage due to the presence of many ocular barriers like external barriers, rapid loss of the instilled solution from the precorneal area and nasolacrimal drainage system. Systemic absorption caused systemic side effects varying from mild to life-threatening events. The main objective of this review is to explore the role of colloidal delivery of drug to minimize the drawbacks associated with them. This review provides an insight into the various constraints associated with ocular drug delivery, summarizes recent findings and applications of colloidal delivery systems, i.e. nanoparticles, nanosuspensions, liposomes, niosomes, dendrimers and contact lenses containing nanoparticles have the capacity to distribute ocular drugs to categorical target sites and hold promise to revolutionize the therapy of many ocular perceiver diseases and minimized the circumscription of conventional delivery. Form the basis of literature review, it has been found that the novel delivery system have greater impact to maximize ocular drug absorption, and minimize systemic absorption and side effects.

  14. Laser Pyro System Standardization and Man Rating

    Science.gov (United States)

    Brown, Christopher W.

    2004-01-01

    This viewgraph presentation reviews an X-38 laser pyro system standardization system designed for a new manned rated program. The plans to approve this laser initiation system and preliminary ideas for this system are also provided.

  15. Status of the Aurora laser system: Angular-multiplexed multikilojoule krypton fluoride prototype for inertial fusion

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Goldstone, P.D.; Kristal, R.

    1986-01-01

    In this presentation, the authors report on the present status of the Aurora system including: The operation of the final stage 1-X 1-m laser at the 10-kJ level; the generation of 5-ns pulses by the front end; integration of the front end, multiplexer, amplifiers, and the extraction of long-pulse energy from the amplifier chain. Progress on the design and construction of the demultiplexer are also reported

  16. 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.

  17. Room Temperature Erbium-Doped Yttrium Vanadate (Er:YVO4) Laser and Amplifier

    Science.gov (United States)

    2016-09-01

    10%. We maintained the LDM pump pulse duration at 5 ms, which is much longer than the Er3+ upper laser level (4I13/2) lifetime in YVO4 at RT (3 ms...of 2 ms ranging from 4 to 131 W was used to invert the gain medium. At 1.8 ms into the pump pulse, the 1603-nm seed was turned on for 500 µs. As

  18. GaAs Wideband Low Noise Amplifier Design for Breast Cancer Detection System

    DEFF Research Database (Denmark)

    Yan, Lei; Krozer, Viktor; Delcourt, Sebastien

    2009-01-01

    Modern wideband systems require low-noise receivers with bandwidth approaching 10 GHz. This paper presents ultra-wideband stable low-noise amplifier MMIC with cascode and source follower buffer configuration using GaAs technology. Source degeneration, gate and shunt peaking inductors are used...

  19. A low power bipolar amplifier integrated circuit for the ZEUS silicon strip system

    Energy Technology Data Exchange (ETDEWEB)

    Barberis, E. (Inst. for Particle Physics, Univ. of California, Santa Cruz, CA (United States)); Cartiglia, N. (Inst. for Particle Physics, Univ. of California, Santa Cruz, CA (United States)); Dorfan, D.E. (Inst. for Particle Physics, Univ. of California, Santa Cruz, CA (United States)); Spencer, E. (Inst. for Particle Physics, Univ. of California, Santa Cruz, CA (United States))

    1993-05-01

    A fast low power bipolar chip consisting of 64 amplifier-comparators has been developed for use with silicon strip detectors for systems where high radiation levels and high occupancy considerations are important. The design is described and test results are presented. (orig.)

  20. Semiconductor optical amplifier-based heterodyning detection for resolving optical terahertz beat-tone signals from passively mode-locked semiconductor lasers

    International Nuclear Information System (INIS)

    Latkowski, Sylwester; Maldonado-Basilio, Ramon; Carney, Kevin; Parra-Cetina, Josue; Philippe, Severine; Landais, Pascal

    2010-01-01

    An all-optical heterodyne approach based on a room-temperature controlled semiconductor optical amplifier (SOA) for measuring the frequency and linewidth of the terahertz beat-tone signal from a passively mode-locked laser is proposed. Under the injection of two external cavity lasers, the SOA acts as a local oscillator at their detuning frequency and also as an optical frequency mixer whose inputs are the self-modulated spectrum of the device under test and the two laser beams. Frequency and linewidth of the intermediate frequency signal (and therefore, the beat-tone signal) are resolved by using a photodiode and an electrical spectrum analyzer.

  1. Designing a Signal Conditioning System with Software Calibration for Resistor-feedback Patch Clamp Amplifier.

    Science.gov (United States)

    Hu, Gang; Zhu, Quanhui; Qu, Anlian

    2005-01-01

    In this paper, a programmable signal conditioning system based on software calibration for resistor-feedback patch clamp amplifier (PCA) has been described, this system is mainly composed of frequency correction, programmable gain and filter whose parameters are configured by software automatically to minimize the errors, A lab-designed data acquisition system (DAQ) is used to implement data collections and communications with PC. The laboratory test results show good agreement with design specifications.

  2. An ultra-wideband tunable multi-wavelength Brillouin fibre laser based on a semiconductor optical amplifier and dispersion compensating fibre in a linear cavity configuration

    International Nuclear Information System (INIS)

    Zulkifli, M Z; Ahmad, H; Hassan, N A; Jemangin, M H; Harun, S W

    2011-01-01

    A multi-wavelength Brillouin fibre laser (MBFL) with an ultra-wideband tuning range from 1420 nm to 1620 nm is demonstrated. The MBFL uses an ultra-wideband semiconductor optical amplifier (SOA) and a dispersion compensating fibre (DCF) as the linear gain medium and nonlinear gain medium, respectively. The proposed MBFL has a wide tuning range covering the short (S-), conventional (C-) and long (L-) bands with a wavelength spacing of 0.08 nm, making it highly suitable for DWDM system applications. The output power of the observed Brillouin Stokes ranges approximately from -5.94 dBm to -0.41 dBm for the S-band, from -4.34 dBm to 0.02 dBm for the C-band and from -2.19 dBm to 0.39 dBm for the L-band. The spacing between each adjacent wavelengths of all the three bands is about 0.08 nm, which is approximately 10.7 GHz for the frequency domain. (lasers)

  3. Study of the amplified spontaneous emission spectral width and gain coefficient for a KrF laser in unsaturated and saturated conditions

    International Nuclear Information System (INIS)

    Hariri, A; Sarikhani, S

    2014-01-01

    On the basis of a model of a geometrically dependent gain coefficient, the amplified spontaneous emission (ASE) spectral width was calculated analytically for the nearly resonant transition of ν ∼ ν 0 , and also numerically for a wide range of transition frequencies. For this purpose, the intensity rate equation was used under unsaturated and saturated conditions. For verifying the proposed model, reported measurements of the ASE energy versus the excitation length for a KrF laser were used. For the excitation length of l = 84 cm corresponding to single-path propagation, the ASE spectral width for the homogeneously broadened transition was calculated to be 6.28 Å, to be compared with the measured 4.1 Å spectral width reported for a KrF oscillator utilizing a two-mirror resonator. With the gain parameters obtained from the ASE energy measurements, the unsaturated and saturated gain coefficients for l = 84 cm were calculated to be 0.042 cm −1 and 0.014 cm −1 , respectively. These values of the gain coefficient are comparable to but slightly lower than the measured gain coefficient for laser systems of 80–100 cm excitation lengths reported from different laboratories. (letter)

  4. Approach to compact terawatt CO2 laser system for particle acceleration

    International Nuclear Information System (INIS)

    Pogorelsky, I.V.; Kimura, W.D.; Fisher, C.H.; Kannari, F.

    1994-01-01

    A compact table-top 20-GW 50-ps CO 2 laser system is in operation for strong-field physics studies at the ATF. We propose scaling up of the picosecond CO 2 laser to a terawatt peak power level to meet the requirements of advanced laser accelerators. Computer modeling shows that a relatively compact single-beam picosecond CO 2 laser system with a high-pressure x-ray picosecond amplifier of a 10-cm aperture is potentially scalable to the ∼1-TW peak power level

  5. Time-Dependent Simulation of Free-Electron Laser Amplifiers and Oscillators

    CERN Document Server

    Freund, H

    2005-01-01

    Time-dependent FEL simulations use a variety of techniques. Most simulations use a slowly varying envelope approximation (SVEA). One such technique assumes that the envelope varies only in z combined with a field representation as an ensemble of discrete harmonics, which is equivalent to a time-dependent simulation [1] but is computationally prohibitive. A second technique uses an SVEA in both in z and t [2]. The particles and fields are advanced in z using the same process as in steady-state simulations and then the time derivative describing slippage is applied. This is used in wiggler-averaged codes such as GINGER [3] and GENESIS [4]. We describe the inclusion of this technique in the non-wiggler-averaged code MEDUSA [5], which is applied to amplifiers and oscillators. MEDUSA differs from GINGER and GENESIS also in the way the field is treated. GINGER and GENESIS use a field solver and must explicitly propagate the field outside the wiggler oscillators. This is computationally intensive. MEDUSA uses a Gaus...

  6. Doping Optimization for High Efficiency in Semiconductor Diode Lasers and Amplifiers

    Science.gov (United States)

    2016-03-01

    ηiVph αm αm + αi (I − Ith) , (12) where ηi is the internal quantum efficiency, Vph is the voltage associated with the energy of a single photon, and...efficiency. In general, this could be a negligible detail; however, for certain cases such as V0 Vph , the difference could be significant, since...communications applications. Bour and Rosen provided an expression for the maximum PCE of a diode laser, given as [12] ηPCE = ηi Vph V0 αm αm + αi x( 1 + √ 1 + x

  7. Spectral characteristics of ultra-short laser pulses in plasma amplifiers

    Czech Academy of Sciences Publication Activity Database

    Riconda, C.; Weber, Stefan A.; Lancia, L.; Marquès, J.-R.; Mourou, G.A.; Fuchs, J.

    2013-01-01

    Roč. 20, č. 8 (2013), "083115-1"-"083115-10" ISSN 1070-664X R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk EE2.3.20.0279 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OPVK 3 Laser Zdroj(XE) CZ.1.07/2.3.00/20.0279 Program:EE Institutional support: RVO:68378271 Keywords : amplification * compression * generation * intensity * extreme * optics * light Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.249, year: 2013

  8. ARGOS laser system mechanical design

    Science.gov (United States)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  9. All-optical NRZ-to-RZ data format conversion with optically injected laser diode or semiconductor optical amplifier

    Science.gov (United States)

    Lin, Gong-Ru; Chang, Yung-Cheng; Yu, Kun-Chieh

    2006-09-01

    By injecting the optical NRZ data into a Fabry-Perot laser diode (FPLD) synchronously modulated at below threshold condition or a semiconductor optical amplifier (SOA) gain-depleted with a backward injected clock stream, the all-optical non-return to zero (NRZ) to return-to-zero (RZ) format conversion of a STM-64 date-stream for synchronous digital hierarchy (SDH) or an OC-192 data stream for synchronous optical network (SONET) in high-speed fiber-optic communication link can be performed. Without the assistance of any complicated RF electronic circuitry, the output RZ data-stream at bit rate of up to 10 Gbit/s is successfully transformed in the optically NRZ injection-locked FPLD, in which the incoming NRZ data induces gain-switching of the FPLD without DC driving current or at below threshold condition. A power penalty of 1.2 dB is measured after NRZ-to-RZ transformation in the FPLD. Alternatively, the all-optical 10Gbits/s NRZ-to-RZ format conversion can also be demonstrated in a semiconductor optical amplifier under a backward dark-optical-comb injection with its duty-cycle 70%, which is obtained by reshaping from the received data clock at 10 GHz. The incoming optical NRZ data-stream is transformed into a pulsed RZ data-stream with its duty-cycle, rms timing jitter, and conversion gain of 15%, 4ps, and 3dB, respectively. In contrast to the FPLD, the SOA based NRZ-to-RZ converter exhibits an enhanced extinction ratio from 7 to 13 dB, and BER of 10 -13 at -18.5 dBm. In particular, the power penalty of the received RZ data-stream has greatly improved by 5 dB as compared to that obtained from FPLD.

  10. Development of automatic laser welding system

    International Nuclear Information System (INIS)

    Ohwaki, Katsura

    2002-01-01

    Laser are a new production tool for high speed and low distortion welding and applications to automatic welding lines are increasing. IHI has long experience of laser processing for the preservation of nuclear power plants, welding of airplane engines and so on. Moreover, YAG laser oscillators and various kinds of hardware have been developed for laser welding and automation. Combining these welding technologies and laser hardware technologies produce the automatic laser welding system. In this paper, the component technologies are described, including combined optics intended to improve welding stability, laser oscillators, monitoring system, seam tracking system and so on. (author)

  11. SHIVA Nd: glass disk-amplifier-assembly facility and special purpose fixtures

    International Nuclear Information System (INIS)

    Jones, W.A.; Patton, H.G.; Stowers, I.F.; Wentworth, D.E.

    1977-09-01

    The facility built to assemble and maintain the laser amplifiers in the SHIVA Laser System is described. The facility is a Class-100 clean room which includes a high pressure solvent spray box, optical inspection equipment, and several unique amplifier-assembly fixtures

  12. Optically pumped alkali laser and amplifier using helium-3 buffer gas

    Science.gov (United States)

    Beach, Raymond J.; Page, Ralph; Soules, Thomas; Stappaerts, Eddy; Wu, Sheldon Shao Quan

    2010-09-28

    In one embodiment, a laser oscillator is provided comprising an optical cavity, the optical cavity including a gain medium including an alkali vapor and a buffer gas, the buffer gas including .sup.3He gas, wherein if .sup.4He gas is also present in the buffer gas, the ratio of the concentration of the .sup.3He gas to the .sup.4He gas is greater than 1.37.times.10.sup.-6. Additionally, an optical excitation source is provided. Furthermore, the laser oscillator is capable of outputting radiation at a first frequency. In another embodiment, an apparatus is provided comprising a gain medium including an alkali vapor and a buffer gas including .sup.3He gas, wherein if .sup.4He gas is also present in the buffer gas, the ratio of the concentration of the .sup.3He gas to the .sup.4He gas is greater than 1.37.times.10.sup.-6. Other embodiments are also disclosed.

  13. Some characteristics of isotopic separation laser systems

    International Nuclear Information System (INIS)

    Pochon, E.

    1988-01-01

    The principle of Laser Isotope Separation (LIS) is simple and based on either selective electronic photoexcitation and photoionization of atomic vapor, or selective vibrational photoexcitation and photodissociation of molecules in the gas phase. These processes, respectively called SILVA (AVLIS) and SILMO (MLIS) in France, both use specific laser systems with wavelengths spanning from infrared to ultraviolet. This article describes briefly some of the characteristics of a SILVA laser system. Following a three-step process, a SILVA laser system is based on dye copper vapor lasers. The pulse dye lasers provide the tunable laser light and are optically pumped by copper vapor laser operating at high repetition rates. In order to meet plant laser system requirements, the main improvements under way relate to copper vapor laser devices the power capability, efficiency, reliability and lifetime of which have to be increased. 1 fig

  14. Radar Waveform Pulse Analysis Measurement System for High-Power GaN Amplifiers

    Science.gov (United States)

    Thrivikraman, Tushar; Perkovic-Martin, Dragana; Jenabi, Masud; Hoffman, James

    2012-01-01

    This work presents a measurement system to characterize the pulsed response of high-power GaN amplifiers for use in space-based SAR platforms that require very strict amplitude and phase stability. The measurement system is able to record and analyze data on three different time scales: fast, slow, and long, which allows for greater detail of the mechanisms that impact amplitude and phase stability. The system is fully automated through MATLAB, which offers both instrument control capability and in-situ data processing. To validate this system, a high-power GaN HEMT amplifier operated in saturation was characterized. The fast time results show that variations to the amplitude and phase are correlated to DC supply transients, while long time characteristics are correlated to temperature changes.

  15. Amplifier for nuclear spectrometry

    International Nuclear Information System (INIS)

    Suarez Canner, E.

    1996-01-01

    The spectroscopy amplifier model AE-020 is designed to adjust suitable the pulses coming from nuclear radiation detectors. Due to is capacity and specifications, the amplifier can be used together with high and medium resolution spectroscopy system

  16. Portable musical instrument amplifier

    Science.gov (United States)

    Christian, David E.

    1990-07-24

    The present invention relates to a musical instrument amplifier which is particularly useful for electric guitars. The amplifier has a rigid body for housing both the electronic system for amplifying and processing signals from the guitar and the system's power supply. An input plug connected to and projecting from the body is electrically coupled to the signal amplifying and processing system. When the plug is inserted into an output jack for an electric guitar, the body is rigidly carried by the guitar, and the guitar is operatively connected to the electrical amplifying and signal processing system without use of a loose interconnection cable. The amplifier is provided with an output jack, into which headphones are plugged to receive amplified signals from the guitar. By eliminating the conventional interconnection cable, the amplifier of the present invention can be used by musicians with increased flexibility and greater freedom of movement.

  17. Diode-laser-pump module with integrated signal ports for pumping amplifying fibers and method

    Science.gov (United States)

    Savage-Leuchs,; Matthias, P [Woodinville, WA

    2009-05-26

    Apparatus and method for collimating pump light of a first wavelength from laser diode(s) into a collimated beam within an enclosure having first and second optical ports, directing pump light from the collimated beam to the first port; and directing signal light inside the enclosure between the first and second port. The signal and pump wavelengths are different. The enclosure provides a pump block having a first port that emits pump light to a gain fiber outside the enclosure and that also passes signal light either into or out of the enclosure, and another port that passes signal light either out of or into the enclosure. Some embodiments use a dichroic mirror to direct pump light to the first port and direct signal light between the first and second ports. Some embodiments include a wavelength-conversion device to change the wavelength of at least some of the signal light.

  18. Los Alamos free-electron laser (FEL) rf system

    International Nuclear Information System (INIS)

    Tallerico, P.J.; Lynch, M.T.

    1985-01-01

    The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements

  19. The development and progress of XeCl Excimer laser system

    Science.gov (United States)

    Zhang, Yongsheng; Ma, Lianying; Wang, Dahui; Zhao, Xueqing; Zhu, Yongxiang; Hu, Yun; Qian, Hang; Shao, Bibo; Yi, Aiping; Liu, Jingru

    2015-05-01

    A large angularly multiplexed XeCl Excimer laser system is under development at the Northwest Institute of Nuclear Technology (NINT). It is designed to explore the technical issues of uniform and controllable target illumination. Short wavelength, uniform and controllable target illumination is the fundamental requirement of high energy density physics research using large laser facility. With broadband, extended light source and multi-beam overlapping techniques, rare gas halide Excimer laser facility will provide uniform target illumination theoretically. Angular multiplexing and image relay techniques are briefly reviewed and some of the limitations are examined to put it more practical. The system consists of a commercial oscillator front end, three gas discharge amplifiers, two electron beam pumped amplifiers and the optics required to relay, encode and decode the laser beam. An 18 lens array targeting optics direct and focus the laser in the vacuum target chamber. The system is operational and currently undergoing tests. The total 18 beams output energy is more than 100J and the pulse width is 7ns (FWHM), the intensities on the target will exceed 1013W/cm2. The aberration of off-axis imaging optics at main amplifier should be minimized to improve the final image quality at the target. Automatic computer controlled alignment of the whole system is vital to efficiency and stability of the laser system, an array of automatic alignment model is under test and will be incorporated in the system soon.

  20. Beam propagation considerations in the Aurora laser system

    International Nuclear Information System (INIS)

    Rosoche, L.A.; Mc Leod, J.; Hanlon, J.A.

    1987-01-01

    Aurora is a high-power KrF laser system now being constructed for inertial confinement fusion (ICF) studies. It will use optical angular multiplexing and serial amplification by electron-beam-driven KrF amplifiers to deliver a stacked, multikilojoule 5-ns-duration laser pulse to ICF targets. The requirements of angular multiplexing KrF lasers at the multikilojoule level dictate path lengths on the order of 1 km. The inherent complicated path crossings produced by angular multiplexing and pulse stacking do not allow isolation of individual beam lines, so the optical quality of the long beam paths must be controlled. Propagation of the 248-nm light beams over long paths in air is affected by scattering, absorption thermal gradients and turbulence, beam alignment, and control and optical component figure errors

  1. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m-1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain ratio

  2. An AC modulated near infrared gain calibration system for a "Violin-Mode" transimpedance amplifier, intended for advanced LIGO suspensions.

    Science.gov (United States)

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a "tall-thin" rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse "Violin-Mode" vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor's DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor's more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz-300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m(-1) was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC/DC transimpedance gain

  3. Improved performance of the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Jones, J.E.; Czuchlewski, S.J.; Turner, T.P.; Watt, R.G.; Thomas, S.J.; Netz, D.A.; Tallman, C.R.; Figueira, J.F.

    1990-01-01

    This paper reports on Aurora the Los Alamos National Laboratory short pulse high power krypton-fluoride laser system. It serves as an end-to-end technology demonstration prototype for large scale UV laser systems for short wavelength inertial confinement fusion (ICF) research. The system employs optical angular multiplexing and serial amplification by electron-beam driven KrF laser amplifiers. The 1-5-ns pulse of the Aurora front end is split into ninety-six beams which are angularly and temporally multiplexed to produce a 480-ns pulse train for amplification by four KrF laser amplifiers. The largest amplifier, the large aperture module (LAM), has a 1-m square aperture and a gain length of 2 m. In the present system configuration half (forty-eight) of the amplified pulses are demultiplexed using different optical path lengths and delivered simultaneously to target. The system has not been optimized, and several near term improvements are expected to result in significant increases in both delivered energy and target irradiance. Removing the twelve calorimeters from the lens plate and allowing forty-eight beams to go to target will increase delivered energy by 33%. Relatively minor modifications to the front end should result in a 30% increase in system output energy. Replacement of damaged optics will increase transmission into the preamplifier by at least 25%. New optics and reduction of retro-pulses will allow the preamplifier stage gain to be increased by 50%

  4. Opportunistic Energy-Aware Amplify-and-Forward Cooperative Systems with Imperfect CSI

    KAUST Repository

    Amin, Osama

    2015-07-29

    Recently, much attention has been paid to the green design of wireless communication systems using energy efficiency (EE) metrics that should capture all energy consumption sources to deliver the required data. In this paper, we design an energyefficient relay assisted communication system based on estimated channel state information (CSI). It employs amplify-andforward relaying and switches between different communication schemes, which are known as direct-transmission, two-hop and cooperative-transmission schemes, using the estimated CSI in order to maximize the EE. Two estimation strategies are assumed, namely disintegrated channel estimation and cascaded channel estimation. To formulate an accurate EE metric for the proposed opportunistic amplify-and-forward system, the channel estimation cost is reflected on the EE metric by including its impact in the signal-to-noise ratio term and in the energy consumption during the channels estimation phase. Based on the formulated EE metric, we propose an adaptive power allocation algorithm to maximize the EE of the proposed opportunistic amplify-andforward system with channel estimation. Furthermore, we study the impact of the estimation parameters on the proposed system via simulation examples.

  5. 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.

  6. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.; Wong, Aloysius Tze; Ng, Tien Khee

    2016-01-01

    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.

  7. High-power free-electron laser amplifier using a scalloped electron beam and a two-stage wiggler

    Directory of Open Access Journals (Sweden)

    D. C. Nguyen

    2006-05-01

    Full Text Available High-power free-electron laser (FEL amplifiers present many practical design and construction problems. One such problem is possible damage to any optical beam control elements beyond the wiggler. The ability to increase the optical beam’s divergence angle after the wiggler, thereby reducing the intensity on the first optical element, is important to minimize such damage. One proposal to accomplish this optical beam spreading is to pinch the electron beam thereby focusing the radiation as well. In this paper, we analyze an approach that relies on the natural betatron motion to pinch the electron beam near the end of the wiggler. We also consider a step-tapered, two-stage wiggler to enhance the efficiency. The combination of a pinched electron beam and step-taper wiggler leads to additional optical guiding of the optical beam. This novel configuration is studied in simulation using the MEDUSA code. For a representative set of beam and wiggler parameters, we discuss (i the effect of the scalloped beam on the interaction in the FEL and on the focusing and propagation of the radiation, and (ii the efficiency enhancement in the two-stage wiggler.

  8. An overview of Aurora: a multi-kilojoule KrF laser system for inertial confinement fusion

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Bowling, P.S.; Burrows, M.D.; Kang, M.; Hanlon, J.; McLeod, J.; York, G.W.

    1986-01-01

    Aurora is a short-pulse high-power krypton-fluoride laser system that serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems of interest for short wavelength inertial confinement fusion (ICF) studies. The system is designed to employ optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers to deliver 248 nm, 5-ns duration multi-kilojoule laser pulses to ICF targets using a beam train of approximately 1 km in length. The goals for the system are discussed and the design features of the major system components: front-end lasers, amplifier train, and the alignment and controls systems are summarised. (author)

  9. Test results of the signal processing and amplifier unit for the emittance measurement system

    International Nuclear Information System (INIS)

    Stawiszynski, L.; Schneider, S.

    1984-01-01

    The signal processing and amplifier unit for the emittance measurement system is the unit with which the beam current on the harp-wires and the slit is measured and converted to a digital output. Temperature effects are very critical at low currents and the purpose of the test measurements described in this report was mainly to establish the accuracy and repeatability of the measurements under the influence of temperature variations

  10. Aurora: A short-pulse multikilojoule KrF inertial fusion laser system

    International Nuclear Information System (INIS)

    Rosocha, L.A.

    1985-01-01

    Aurora is a laser system that serves as an operating technology demonstration prototype for large-scale high-energy KrF laser systems of interest for inertial fusion applications. This system will incorporate the following elements to achieve an end-to-end 248-nm laser fusion concept demonstration: an injection-locked oscillator-amplifier front end; an optical angular multiplexer to produce 96 encoded optical channels each of 5-nsec duration; a chain of four electron-beam-driven KrF laser amplifiers; automated alignment systems for beam alignment; a decoder to provide for pulse compression of some fraction of the total beam train to be delivered to target, and a target chamber to house and diagnose fusion targets. The front end configuration uses a stable resonator master oscillator to drive an injection-locked unstable resonator slave oscillator. An extension of existing technology has been used to develop an electrooptic switchout at 248 nm that produces a 5-nsec pulse from the longer slave oscillator pulse. This short pulse is amplified by a postamplifier. Using these discharge lasers, the front end then delivers at least 250 mJ of KrF laser light output to the optical encoder

  11. Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

    Directory of Open Access Journals (Sweden)

    Abdelhamid Benazzouz

    2013-09-01

    Full Text Available Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-gain, low-noise integrated neuronal amplifier (NA with the capability of recording local field potentials (LFP and spike activity is presented. In vitro and in vivo characterizations of the tissue/electrode interface, with equivalent impedance as an electrical model for recording in the LFP band using macro-electrodes for rodents, contribute to the NA design constraints. The NA occupies 0.15 mm2 and dissipates 6.73 µW, and was fabricated using a 0.35 µm CMOS process. Test-bench validation indicates that the NA provides a mid-band gain of 20 dB and achieves a low input-referred noise of 4 µVRMS. Ability of the NA to perform spike recording in test-bench experiments is presented. Additionally, an awake and freely moving rodent setup was used to illustrate the integrated NA ability to record LFPs, paving the pathway for future implantable systems for neuromodulation.

  12. Fiber optic analog and timing monitoring system for the antares laser fusion program

    International Nuclear Information System (INIS)

    Longmire, J.L.; Thuot, M.E.

    1981-01-01

    The development and use of two optical fiber systems for the Antares 40 kJ CO 2 laser is described. In the Antares power amplifier, electron guns produce a discharge-sustaining B kA beam of 500 kV electrons. Eight 300 kJ, 3 μs Marx pulsers provide a direct electrical pumping discharge through the laser gas. The electro-optic systems developed allow the measurement of pulsed analog waveforms and trigger timing information within the laser and power systems by a computer based control and data acquisition network

  13. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  14. Self-amplified spontaneous emission in Smith-Purcell free-electron lasers

    International Nuclear Information System (INIS)

    Kim, K.-J.; Song, S.-B.

    2001-01-01

    We present an analysis of a Smith-Purcell system in which a thin current sheet of electrons moves above a grating surface in the direction perpendicular to the grating grooves. We develop a consistent theory for evolution of the electromagnetic field and electron distribution in the exponential growth regime starting from the initial electron noise and the incoming amplitude. The dispersion relation for the complex growth rate for this system is a quadratic equation

  15. Use of a reflective semiconductor optical amplifier and dual-ring architecture design to produce a stable multi-wavelength fiber laser

    International Nuclear Information System (INIS)

    Yeh, Chien-Hung; Chow, Chi-Wai; Lu, Shao-Sheng

    2014-01-01

    In this work, we propose and demonstrate a multi-wavelength laser source produced by utilizing a C-band reflective semiconductor optical amplifier (RSOA) with a dual-ring fiber cavity. Here, the laser cavity consists of an RSOA, a 1 × 2 optical coupler, a 2 × 2 optical coupler and a polarization controller. As a result, thirteen to eighteen wavelengths around the L band could be generated simultaneously when the bias current of the C-band RSOA was driven at 30–70 mA. In addition, the output stabilities of the power and wavelength are also discussed. (paper)

  16. Use of a reflective semiconductor optical amplifier and dual-ring architecture design to produce a stable multi-wavelength fiber laser

    Science.gov (United States)

    Yeh, Chien-Hung; Chow, Chi-Wai; Lu, Shao-Sheng

    2014-05-01

    In this work, we propose and demonstrate a multi-wavelength laser source produced by utilizing a C-band reflective semiconductor optical amplifier (RSOA) with a dual-ring fiber cavity. Here, the laser cavity consists of an RSOA, a 1 × 2 optical coupler, a 2 × 2 optical coupler and a polarization controller. As a result, thirteen to eighteen wavelengths around the L band could be generated simultaneously when the bias current of the C-band RSOA was driven at 30-70 mA. In addition, the output stabilities of the power and wavelength are also discussed.

  17. Interband cascade laser-based ppbv-level mid-infrared methane detection using two digital lock-in amplifier schemes

    Science.gov (United States)

    Song, Fang; Zheng, Chuantao; Yu, Di; Zhou, Yanwen; Yan, Wanhong; Ye, Weilin; Zhang, Yu; Wang, Yiding; Tittel, Frank K.

    2018-03-01

    A parts-per-billion in volume (ppbv) level mid-infrared methane (CH4) sensor system was demonstrated using second-harmonic wavelength modulation spectroscopy (2 f-WMS). A 3291 nm interband cascade laser (ICL) and a multi-pass gas cell (MPGC) with a 16 m optical path length were adopted in the reported sensor system. Two digital lock-in amplifier (DLIA) schemes, a digital signal processor (DSP)-based DLIA and a LabVIEW-based DLIA, were used for harmonic signal extraction. A limit of detection (LoD) of 13.07 ppbv with an averaging time of 2 s was achieved using the DSP-based DLIA and a LoD of 5.84 ppbv was obtained using the LabVIEW-based DLIA with the same averaging time. A rise time of 0→2 parts-per-million in volume (ppmv) and fall time of 2→0 ppmv were observed. Outdoor atmospheric CH4 concentration measurements were carried out to evaluate the sensor performance using the two DLIA schemes.

  18. High speed laser tomography system

    Science.gov (United States)

    Samsonov, D.; Elsaesser, A.; Edwards, A.; Thomas, H. M.; Morfill, G. E.

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120000slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  19. Consecutive Food and Respiratory Allergies Amplify Systemic and Gut but Not Lung Outcomes in Mice.

    Science.gov (United States)

    Bouchaud, Gregory; Gourbeyre, Paxcal; Bihouée, Tiphaine; Aubert, Phillippe; Lair, David; Cheminant, Marie-Aude; Denery-Papini, Sandra; Neunlist, Michel; Magnan, Antoine; Bodinier, Marie

    2015-07-22

    Epidemiological data suggest a link between food allergies and the subsequent development of asthma. Although this progression may result from the additional effects of exposure to multiple allergens, whether both allergies amplify each other's effects remains unknown. This study investigated whether oral exposure to food allergens influences the outcomes of subsequent respiratory exposure to an asthma-inducing allergen. Mice were sensitized and orally challenged with wheat (FA) and then exposed to house dust mite (HDM) extract (RA). Immunoglobulin (Ig), histamine, and cytokine levels were assayed by ELISA. Intestinal and lung physiology was assessed. Ig levels, histamine release, and cytokine secretion were higher after exposure to both allergens than after separate exposure to each. Intestinal permeability was higher, although airway hyper-responsiveness and lung inflammation remained unchanged. Exposure to food and respiratory allergens amplifies systemic and gut allergy-related immune responses without any additional effect on lung function and inflammation.

  20. A minimum bit error-rate detector for amplify and forward relaying systems

    KAUST Repository

    Ahmed, Qasim Zeeshan; Alouini, Mohamed-Slim; Aissa, Sonia

    2012-01-01

    In this paper, a new detector is being proposed for amplify-and-forward (AF) relaying system when communicating with the assistance of L number of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the system. The complexity of the system is further reduced by implementing this detector adaptively. The proposed detector is free from channel estimation. Our results demonstrate that the proposed detector is capable of achieving a gain of more than 1-dB at a BER of 10 -5 as compared to the conventional minimum mean square error detector when communicating over a correlated Rayleigh fading channel. © 2012 IEEE.

  1. A minimum bit error-rate detector for amplify and forward relaying systems

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2012-05-01

    In this paper, a new detector is being proposed for amplify-and-forward (AF) relaying system when communicating with the assistance of L number of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the system. The complexity of the system is further reduced by implementing this detector adaptively. The proposed detector is free from channel estimation. Our results demonstrate that the proposed detector is capable of achieving a gain of more than 1-dB at a BER of 10 -5 as compared to the conventional minimum mean square error detector when communicating over a correlated Rayleigh fading channel. © 2012 IEEE.

  2. Optical performance of the Gemini carbon dioxide laser fusion system

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Hayden, J.J.; Liberman, I.

    1979-01-01

    The performance of the Gemini two beam carbon dioxide laser fusion system was recently upgraded by installation of optical components with improved quality in the final amplifier. A theoretical analysis was conducted in conjunction with measurements of the new performance. The analysis and experimental procedures, and results obtained are reported and compared. Good agreement was found which was within the uncertainties of the analysis and the inaccuracies of the experiments. The focal spot Strehl ratio was between 0.24 and 0.3 for both beams

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

    Science.gov (United States)

    Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

    2016-01-01

    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.

  4. A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Mohania, Praveen; Mahawar, Ashish; Shrivastava, Purushottam; Gupta, P. D. [Raja Rammana Centre for Advanced Technology (RRCAT), Indore 452013 (India)

    2013-09-15

    A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

  5. Petawatt laser system for the fast ignition studies at ILE, Osaka University

    International Nuclear Information System (INIS)

    Izawa, Y.

    2002-01-01

    We have developed a PW Nd:glass laser system, which can deliver 1 PW output with 500 J in 0.5 ps, to study a fast ignitor concept in laser fusion. In the front end of this system, the optical parametric chirped-pulse amplifier (OPCPA) was introduced. The OPCPA solves several problems arising in an existing Ti:sapphire regenerative amplifier, such as low single-pass gain, high prepulse and output fluctuation. A booster amplifier is a Cassegrain-type three pass disk system having a 350 mm clear aperture, which generated 1.1 kJ output energy with the spectral width of 3.7 nm corresponding to 0.5 ps in Fourier transform limited pulse. The spatial phase aberration mainly caused in the booster amplifier is corrected using a deformable mirror. The laser pulse is compressed by a pair of 1-m diffraction gratings and focused by a parabolic mirror. The timing jitter between PW laser and GEKKO XII is less than 10 ps, which was attained by injecting a weak pulse splitted out from the front end into the preamplifier of GEKKO XII. (author)

  6. Improvements of the ruby laser oscillator system for laser scattering

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Kumagai, Katsuaki; Kawakami, Tomohide; Matoba, Tohru; Funahashi, Akimasa

    1978-10-01

    A ruby laser oscillator system is used to measure electron temperatures of the Tokamak plasmas(JFT-2 and JFT-2a). Improvements have been made of the laser oscillator to obtain the correct values. Described are the improvements and the damages of a ruby rod and a KD*P crystal for Q-switching by laser beam. Improvement are the linear Xe lamp replaced by a helical Xe lamp and in the electrical circuit for Q-switching. The damage of an optical component by a laser beam should be clarified from the damage data; the cause is not found yet. (author)

  7. Implementation of Lean System on Erbium Doped Fibre Amplifier Manufacturing Process to Reduce Production Time

    Science.gov (United States)

    Maneechote, T.; Luangpaiboon, P.

    2010-10-01

    A manufacturing process of erbium doped fibre amplifiers is complicated. It needs to meet the customers' requirements under a present economic status that products need to be shipped to customers as soon as possible after purchasing orders. This research aims to study and improve processes and production lines of erbium doped fibre amplifiers using lean manufacturing systems via an application of computer simulation. Three scenarios of lean tooled box systems are selected via the expert system. Firstly, the production schedule based on shipment date is combined with a first in first out control system. The second scenario focuses on a designed flow process plant layout. Finally, the previous flow process plant layout combines with production schedule based on shipment date including the first in first out control systems. The computer simulation with the limited data via an expected value is used to observe the performance of all scenarios. The most preferable resulted lean tooled box systems from a computer simulation are selected to implement in the real process of a production of erbium doped fibre amplifiers. A comparison is carried out to determine the actual performance measures via an analysis of variance of the response or the production time per unit achieved in each scenario. The goodness of an adequacy of the linear statistical model via experimental errors or residuals is also performed to check the normality, constant variance and independence of the residuals. The results show that a hybrid scenario of lean manufacturing system with the first in first out control and flow process plant lay out statistically leads to better performance in terms of the mean and variance of production times.

  8. Ho:YLF & Ho:LuLF slab amplifier system delivering 200 mJ, 2 µm single-frequency pulses

    CSIR Research Space (South Africa)

    Strauss, HJ

    2011-07-01

    Full Text Available A single-frequency single-pass amplifier based on Ho:YLF and Ho:LuLF in a scalable slab architecture delivering up to 210 mJ at 2064 nm is demonstrated. The amplifier was end-pumped by a 1890 nm Tm:YLF slab laser and was seeded with a 69 mJ single...

  9. The Effect of Amplifier Bias Drift on Differential Magnitude Estimation in Multiple-Star Systems

    Science.gov (United States)

    Tyler, David W.; Muralimanohar, Hariharan; Borelli, Kathy J.

    2007-02-01

    We show how the temporal drift of CCD amplifier bias can cause significant relative magnitude estimation error in speckle interferometric observations of multiple-star systems. When amplifier bias varies over time, the estimation error arises if the time between acquisition of dark-frame calibration data and science data is long relative to the timescale over which the bias changes. Using analysis, we show that while detector-temperature drift over time causes a variation in accumulated dark current and a residual bias in calibrated imagery, only amplifier bias variations cause a residual bias in the estimated energy spectrum. We then use telescope data taken specifically to investigate this phenomenon to show that for the detector used, temporal bias drift can cause residual energy spectrum bias as large or larger than the mean value of the noise energy spectrum. Finally, we use a computer simulation to demonstrate the effect of residual bias on differential magnitude estimation. A supplemental calibration technique is described in the appendices.

  10. Adaptive Synchronization of Chaotic Systems considering Performance Parameters of Operational Amplifiers

    Directory of Open Access Journals (Sweden)

    Sergio Ruíz-Hernández

    2015-01-01

    Full Text Available This paper addresses an adaptive control approach for synchronizing two chaotic oscillators with saturated nonlinear function series as nonlinear functions. Mathematical models to characterize the behavior of the transmitter and receiver circuit were derived, including in the latter the adaptive control and taking into account, for both chaotic oscillators, the most influential performance parameters associated with operational amplifiers. Asymptotic stability of the full synchronization system is studied by using Lyapunov direct method. Theoretical derivations and related results are experimentally validated through implementations from commercially available devices. Finally, the full synchronization system can easily be reproducible at a low cost.

  11. Impact of Nonlinear Power Amplifier on Link Adaptation Algorithm of OFDM Systems

    DEFF Research Database (Denmark)

    Das, Suvra S.; Tariq, Faisal; Rahman, Muhammad Imadur

    2007-01-01

    The impact of non linear distortion due to High Power Amplifier (HPA) on the performance of Link Adaptation (LA) - Orthogonal Frequency Division Multiplexing (OFDM) based wireless system is analyzed. The performance of both Forward Error Control Coding (FEC) en-coded and uncoded system is evaluated....... LA maximizes the throughput while maintaining a required Block Error Rate (BLER). It is found that when OFDM signal, which has high PAPR, suffers non linear distortion due to non ideal HPA, the LA fails to meet the target BLER. Detailed analysis of the distortion and effects on LA are presented...

  12. Integration of the Aurora KrF ICF laser system at Los Alamos

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Blair, L.S.

    1988-01-01

    The Aurora laser system, under construction at the Los Alamos National Laboratory for the past few years, is now being integrated into a working system for examining the applicability of high-power KrF lasers to inertial confinement fusion (ICF). The design principles of the system have been described in detail in earlier publications and conferences. Multikilojoule 248-nm 5-ns duration laser pulses, which have been derived from angular-multiplexed electron-beam-driven KrF amplifiers, are to be delivered to ICF targets when the system is fully integrated. The authors describe the progress of the Aurora system toward the goal of delivering energy (MkJ/48 pulses stacked into one 5-ns pulse/200-μm spot) to ICF targets. Integrated performance to date of the front end optical multiplexer/demultiplexer e-beam-driven amplifiers and alignment hardware are discussed in particular. They have concentrated on the demonstration of system integration at a modest (--100-J) level of energy on-target (without the final amplifier stage). They discuss the amplifier gain measurements, the extraction of energy from a chain of three e-beam-driven machines, and progress toward the delivery of on-target energy

  13. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    International Nuclear Information System (INIS)

    Cho, Gyuseong.

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was ∼400 MHz and the noise charge ∼1000 electrons at a 1 μsec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of ∼0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB

  14. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyuseong [Univ. of California, Berkeley, CA (United States)

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was ~400 MHz and the noise charge ~1000 electrons at a 1 μsec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of ~0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  15. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyuseong.

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  16. Conceptual design of a hybrid KrF laser system for ICF commercial applications

    International Nuclear Information System (INIS)

    Harris, D.B.; Lowenthal, D.D.

    1986-01-01

    KrF lasers appear to be the most efficient lasers operating near the optimal wavelength for laser fusion. Most high-efficiency, low-cost KrF laser designs use large electron-beam-driven amplifiers and use pure angular multiplexing for the required pulse compression. A recent study carried out by Los Alamos National Lab. and Spectra Technology has defied a high-efficiency hybrid KrF laser system architecture that uses both angular multiplexing and Raman beam combination. The high overall system efficiency of this hybrid design, ∼ 12%, is achieved primarily through the use of electron-beam sustained discharge lasers (EBSDL), and by using the efficient forward rotational Raman process in hydrogen. The new system appears attractive as a commercial-applications driver because the calculated efficiency is higher than the usual large electron-beam-pumped (EBP) KrF laser/pure angular multiplexing approach. In this paper, the hybrid system architecture will be described, and the trade-offs with respect to the large EBP amplifier/angular multiplexed system will be discussed

  17. Conceptual design of a hybrid KrF laser system for ICF commercial applications

    International Nuclear Information System (INIS)

    Harris, D.B.; Lowenthal, D.D.

    1986-01-01

    KrF lasers appear to be the most efficient lasers operating near the optimal wavelength for laser fusion. Most high-efficiency, low-cost KrF laser designs use large electron-beam driven amplifiers and use pure angular multiplexing for the required pulse compression. A recent study carried out by Los Alamos and Spectra Technology has defined a high-efficiency hybrid KrF laser system architecture that uses both angular multiplexing and Raman beam combination. The high overall system efficiency of this hybrid design, approximately 12%, is achieved primarily through the use of e-beam sustained discharge lasers (EBSDL), and by using the efficient forward rotational Raman process in hydrogen. The new system appears attractive as a commercial-applications driver because the calculated efficiency is higher than the usual large e-beam pumped (EBP) KrF laser/pure angular multiplexing approach. In this paper, the hybrid system architecture is described, and the tradeoffs with respect to the large EBP amplifier/angular multiplexed system are discussed

  18. Precoding Design of MIMO Amplify-and-Forward Communication System With an Energy Harvesting Relay and Possibly Imperfect CSI

    KAUST Repository

    Benkhelifa, Fatma; Alouini, Mohamed-Slim

    2017-01-01

    In this paper, we investigate the simultaneous wireless information and power transfer (SWIPT) in a Multiple-Input Multiple-Output (MIMO) Amplify-and-Forward (AF) relay communication system where the relay is an energy harvesting (EH) node

  19. CO laser angioplasty system: efficacy of manipulatable laser angioscope catheter

    Science.gov (United States)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Sakurada, Masami; Miyamoto, Akira; Arakawa, Koh; Kurita, Akira; Nakamura, Haruo; Takeuchi, Kiyoshi; Utsumi, Atsushi; Akai, Yoshiro

    1992-08-01

    A percutaneous transluminal coronary angioplasty system using a unique combination of CO laser (5 micrometers ) and As-S infrared glass fiber under the guidance of a manipulatable laser angioscope catheter is described. The ablation and guidance functions of this system are evaluated. The angioplasty treatment procedure under angioscope guidance was studied by in vitro model experiment and in vivo animal experiment. The whole angioplasty system is newly developed. That is, a transportable compact medical CO laser device which can emit up to 10 W, a 5 F manipulatable laser angioscope catheter, a thin CO laser cable of which the diameter is 0.6 mm, an angioscope imaging system for laser ablation guidance, and a system controller were developed. Anesthetized adult mongrel dogs (n equals 5) with an artificial complete occlusion in the femoral artery and an artificial human vessel model including occluded or stenotic coronary artery were used. The manipulatability of the catheter was drastically improved (both rotation and bending), therefore, precise control of ablation to expand stenosis was obtained. A 90% artificial stenosis made of human yellow plaque in 4.0 mm diameter in the vessel was expanded to 70% stenosis by repetitive CO laser ablations of which total energy was 220 J. All procedures were performed and controlled under angioscope visualization.

  20. Ball-milled nano-colloids of rare-earth compounds as liquid gain media for capillary optical amplifiers and lasers

    Science.gov (United States)

    Patel, Darayas; Blockmon, Avery; Ochieng, Vanesa; Lewis, Ashley; Wright, Donald M.; Lewis, Danielle; Valentine, Rueben; Valentine, Maucus; Wesley, Dennis; Sarkisov, Sergey S.; Darwish, Abdalla M.; Sarkisov, Avedik S.

    2017-02-01

    Nano-colloids and nano-crystals doped with ions of rare-earth elements have recently attracted a lot of attention in the scientific community due to their potential applications as biomarkers, fluorescent inks, gain media for lasers and optical amplifiers. Many rare-earth doped materials of different compositions, shapes and size distribution have been prepared by different synthetic methods, such as chemical vapor deposition, sol-gel process, micro-emulsion techniques, gas phase condensation methods, hydrothermal methods and laser ablation. In this paper micro-crystalline powder of the rare-earthdoped compound NaYF4:Yb3+, Er3+ was synthesized using a simple wet process followed by baking in open air. Under 980 nm diode laser excitation strong fluorescence in the 100 nm band around 1531-nm peak was observed from the synthesized micro-powder. The micro-powder was pulverized using a ball mill and prepared in the form of nano-colloids in different liquids. The particle size of the obtained nano-colloids was measured using an atomic force microscope and a dynamic light scatterometer. The size of the nano-particles was close to 100-nm. The nano-colloids were utilized as a filling media in capillary optical amplifiers and lasers. The gain of a 7-cm-long capillary optical amplifier (150-micron inner diameter) was as high as 6 dB at 200 mW pump power. The synthesized nano-colloids and the active optical components using them can be potentially used in optical communication, signal processing, optical computing, and other applications.

  1. Multi-channel, fiber-based seed pulse distribution system for femtosecond-level synchronized chirped pulse amplifiers

    Czech Academy of Sciences Publication Activity Database

    Horáček, Martin; Indra, Lukáš; Green, Jonathan T.; Naylon, Jack A.; Tykalewicz, Boguslav; Novák, Jakub; Batysta, František; Mazanec, Tomáš; Horáček, Jakub; Antipenkov, Roman; Hubka, Zbyněk; Boge, Robert; Bakule, Pavel; Rus, Bedřich

    2017-01-01

    Roč. 88, č. 1 (2017), s. 1-6, č. článku 013109. ISSN 0034-6748 R&D Projects: GA MŠk LQ1606; GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : disk amplifier * timing jitter * 1 khz * amplification Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 1.515, year: 2016

  2. Fission fragment excited laser system

    Science.gov (United States)

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  3. A main amplifier circuit and data acquisition system for charged particle detector array

    International Nuclear Information System (INIS)

    Hao Rui; Ge Yucheng

    2011-01-01

    The charged particle detector array has huge amounts of signal and needs high counting rate. To meet the requirements, a main amplifier and analog-to-digital conversion circuit based on high-speed op-amp chips and ADC chip was designed. A 51-MCU was used to control the circuit of ADC and the USB communication chip. The signals were digitized and uploaded by the MCU-ADC-USB circuit. The whole system has a compact hardware structure and a reasonable controlling software, which meet the design requirements. (authors)

  4. 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...

  5. A Read-out and Data Acquisition System for the Outputs of Multi-channel Spectroscopy Amplifiers

    International Nuclear Information System (INIS)

    Kong Jie; Qian Yi; Su Hong; Dong Chengfu

    2009-01-01

    A read-out and data acquisition system for the outputs of multi-channel spectroscopy amplifiers is introduced briefly in this paper. The 16-channel gating integrator/multiplexer developed by us and PXI-DAQ card are used to construct this system. A virtual instrument system for displaying, indicating,measuring and recording of output waveform is accomplished by integrating the PC, hardware, software together flexibly based on the Lab Windows/CVI platform in our read-out and data acquisition system. In this system, an ADC can face the 16 outputs of 16-channel spectroscopy amplifiers, which can improve the system integration and reduce the cost of data acquisition system. The design provided a new way for building the read-out and data acquisition system using the normal modules and spectroscopy amplifiers. This system has been tested and demonstrated that it is intelligent, reliable, real-time and low cost. (authors)

  6. 1.7  μm band narrow-linewidth tunable Raman fiber lasers pumped by spectrum-sliced amplified spontaneous emission.

    Science.gov (United States)

    Zhang, Peng; Wu, Di; Du, Quanli; Li, Xiaoyan; Han, Kexuan; Zhang, Lizhong; Wang, Tianshu; Jiang, Huilin

    2017-12-10

    A 1.7 μm band tunable narrow-linewidth Raman fiber laser based on spectrally sliced amplified spontaneous emission (SS-ASE) and multiple filter structures is proposed and experimentally demonstrated. In this scheme, an SS-ASE source is employed as a pump source in order to avoid stimulated Brillouin scattering. The ring configuration includes a 500 m long high nonlinear optical fiber and a 10 km long dispersion shifted fiber as the gain medium. A segment of un-pumped polarization-maintaining erbium-doped fiber is used to modify the shape of the spectrum. Furthermore, a nonlinear polarization rotation scheme is applied as the wavelength selector to generate lasers. A high-finesse ring filter and a ring filter are used to narrow the linewidth of the laser, respectively. We demonstrate tuning capabilities of a single laser over 28 nm between 1652 nm and 1680 nm by adjusting the polarization controller (PC) and tunable filter. The tunable laser has a 0.023 nm effective linewidth with the high-finesse ring filter. The stable multi-wavelength laser operation of up to four wavelengths can be obtained by adjusting the PC carefully when the pump power increases.

  7. 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

  8. Multiplex electric discharge gas laser system

    Science.gov (United States)

    Laudenslager, James B. (Inventor); Pacala, Thomas J. (Inventor)

    1987-01-01

    A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately.

  9. Muscle trade-offs in a power-amplified prey capture system.

    Science.gov (United States)

    Blanco, M Mendoza; Patek, S N

    2014-05-01

    Should animals operating at great speeds and accelerations use fast or slow muscles? The answer hinges on a fundamental trade-off: muscles can be maximally fast or forceful, but not both. Direct lever systems offer a straightforward manifestation of this trade-off, yet the fastest organisms use power amplification, not direct lever action. Power-amplified systems typically use slow, forceful muscles to preload springs, which then rapidly release elastic potential energy to generate high speeds and accelerations. However, a fast response to a stimulus may necessitate fast spring-loading. Across 22 mantis shrimp species (Stomatopoda), this study examined how muscle anatomy correlates with spring mechanics and appendage type. We found that muscle force is maximized through physiological cross-sectional area, but not through sarcomere length. Sit-and-wait predators (spearers) had the shortest sarcomere lengths (fastest contractions) and the slowest strike speeds. The species that crush shells (smashers) had the fastest speeds, most forceful springs, and longest sarcomeres. The origin of the smasher clade yielded dazzlingly high accelerations, perhaps due to the release from fast spring-loading for evasive prey capture. This study offers a new window into the dynamics of force-speed trade-offs in muscles in the biomechanical, comparative evolutionary framework of power-amplified systems. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  10. Alignment system for SGII-Up laser facility

    Science.gov (United States)

    Gao, Yanqi; Cui, Yong; Li, Hong; Gong, Lei; Lin, Qiang; Liu, Daizhong; Zhu, Baoqiang; Ma, Weixin; Zhu, Jian; Lin, Zunqi

    2018-03-01

    The SGII-Up laser facility in Shanghai is one of the most important high-power laser facilities in China. It is designed to obtain 24 kJ (3ω) of energy with a square pulse of 3 ns using eight laser beams (two bundles). To satisfy the requirements for the safety, efficiency, and quality, an alignment system is developed for this facility. This alignment system can perform automatic alignment of the preamplifier system, main amplifier system, and harmonic conversion system within 30 min before every shot during the routine operation of the facility. In this article, an overview of the alignment system is first presented. Then, its alignment characteristics are discussed, along with the alignment process. Finally, experimental results, including the alignment results and the facility performance, are reported. The results show that the far-field beam pointing alignment accuracy is better than 3 μrad, and the alignment error of the near-field beam centering is no larger than 1 mm. These satisfy the design requirements very well.

  11. The DEPFET detector-amplifier structure for spectroscopic imaging in astronomy and for experiments at free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, G., E-mail: gerhard.lutz@pnsensor.de; Aschauer, S.; Majewski, P.; Holl, P.; Strüder, L.

    2017-02-11

    The DEPFET detector-amplifier structure possesses several unique properties which make it extremely useful as readout element in semiconductor detectors and in particular as building block of semiconductor pixel detectors. Variations of DEPFETs can be tuned to specific requirements as to be sensitive only in predetermined time intervals, to measure signal charge with sub-electron precision, dead-time-free readout and with signal compression. These devices have been shown to work in simulations and in prototypes. Recently the first two fully developed detector systems have been finished and installed in the MIXS (Mercury Image X-ray Spectrometer) instrument of the Mercury Planetary Orbiter scheduled to be launched in 2017. A further DEPFET detector system under development is the DSSC (Depfet Sensor with Signal Compression) that will be installed in one of the beam-lines of XFEL. The requirements of the two projects are rather different. While the MIXS sensors are supposed to measure precisely the energy and position of single photons down to very low energies but at moderate rates, the DSSC has to measure the number of photons arriving in each pixel within a time interval of 220 ns. Here the challenge is the capability of detecting single X-ray photons in one pixel simultaneously with up to 10,000 photons in some other pixels. Device functioning has been verified with sensors produced in a research laboratory. Now process and design have been adapted to an industrial type production line, allowing additional improvements.

  12. A Spectroscopic Comparison of Femtosecond Laser Modified Fused Silica using kHz and MHz Laser Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Reichman, W J; Krol, D M; Shah, L; Yoshino, F; Arai, A; Eaton, S M; Herman, P R

    2005-09-29

    Waveguides were written in fused silica using both a femtosecond fiber laser with a 1 MHz pulse repetition rate and a femtosecond amplified Ti:sapphire laser with a 1 kHz repetition rate. Confocal Raman and fluorescence microscopy were used to study structural changes in the waveguides written with both systems. A broad fluorescence band, centered at 650 nm, associated with non-bridging oxygen hole center (NBOHC) defects was observed after waveguide fabrication with the MHz laser. With the kHz laser system these defects were only observed for pulse energies above 1 {mu}J. Far fewer NBOHC defects were formed with the MHz laser than with kHz writing, possibly due to thermal annealing driven by heat accumulation effects at 1 MHz. When the kHz laser was used with pulse energies below 1 {mu}J, the predominant fluorescence was centered at 550 nm, a band assigned to the presence of silicon clusters (E{prime}{sub {delta}}). We also observed an increase in the intensity of the 605 cm{sup -1} Raman peak relative to the total Raman intensity, corresponding to an increase in the concentration of 3-membered rings in the lines fabricated with both laser systems.

  13. Operation amplifier

    NARCIS (Netherlands)

    Tetsuya, Saito; Nauta, Bram

    2008-01-01

    To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a differential amplifier circuit 1;

  14. A Low-Power CMOS Trans-Impedance Amplifier for 2.5 Gb/S Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Mojgan Mohseni

    2013-01-01

    Full Text Available This Paper presents a new Trans-impedance amplifier for optical receiver circuits. The amplifier is based on parallel (R-C feedback topology which is optimized for power consumption and uses shunt-peaking technique to enhance the frequency bandwidth of the amplifier. However, the circuit is designed and simulated using 0.18µm CMOS technology parameters. As simulation results show, the amplifier has a gain of 67.5dBΩ, bandwidth of 3GHz while consumes only 12.16 mW power which shows a very good performance for using in a 2.5Gb/S (SONET OC-48 optical communication system. Finally, as the simulated Eye-Diagram shows, the circuit has a very good performance for a 2.5Gb/S system for a 10µA input current.

  15. Gain measurement in a CW medium-power diode pumped Nd:YAG laser amplifier by ASE analysis

    International Nuclear Information System (INIS)

    Razzaghi, D; Hajiesmaeilbaigi, F; Ruzbehani, M

    2014-01-01

    Using the relation between amplified spontaneous emission intensity and gain, a set of formulas is derived for gain evaluation by comparing fluorescence yield in two different lengths of the active medium. Experimental measurements are carried out and gain is calculated by solving the derived formula. For comparison, measurements are also carried out using the probe beam method, which shows good agreement between the two methods in a typical CW medium-power diode pumped Nd:YAG amplifier. (paper)

  16. Materials for spaceborne laser systems

    International Nuclear Information System (INIS)

    Gusarov, A.

    2006-01-01

    Advanced laser systems are attracting a growing interest for space missions, in particular for LIDAR (LIght Detection And Ranging) applications. An important issue for the LIDARs is the very strict requirements on the optical performance and more specifically the need for a high optical output power combined with a nearly perfect output beam quality. These features are traditionally in conflict with each other. Thermally induced phase distortions indeed corrupt the beam quality of high-power solid-state lasers and it becomes increasingly difficult to maintain a good beam quality while increasing the output power. A possible solution of the problem is to use the optical phase conjugation, which provides a method to dynamically correct for those aberrations. A process by which phase-conjugated waves can be generated is the SBS (stimulated Brillouin scattering). SBS mirrors commonly used in terrestrial application are based on liquids or gases, which are not 'space-friendly' and often toxic. The solid-state alternative seems the most appropriate for space. Such PCMs (Phase-Conjugating Mirrors) have been the subject of many research efforts in recent years and a significant progress in improving their characteristics has been achieved. However, the issue of space qualification remains open. To address it, the European Space Agency initiated in 2004 the research project named Solid-State Phase Conjugation, Radiation Testing and Evaluation for Core Laser Technologies with the TRT (Thales Research and Technology), France, as the prime contractor, and the CSL (Centre Spatial de Liege) and SCKCEN as the subcontractors. The project is to be completed in 2006. To qualify a PCM for a spaceborne laser system, one has to address a number of specific issues. Such a component must be mechanically rugged to sustain vibrations during the launch phase, provide a low out-gassing to prevent optical surfaces contamination in vacuum, be highly reliable to operate properly without

  17. Dynamically variable spot size laser system

    Science.gov (United States)

    Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

    2012-01-01

    A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

  18. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    International Nuclear Information System (INIS)

    Ali, Mohammed H; Chakrabarty, C K; Hock, Goh C; Abdalla, Ahmed N

    2013-01-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  19. Development of an Amplifier for Electronic Stethoscope System and Heart Sound Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. J.; Kang, D. K. [Chongju University, Chongju (Korea)

    2001-05-01

    The conventional stethoscope can not store its stethoscopic sounds. Therefore a doctor diagnoses a patient with instantaneous stethoscopic sounds at that time, and he can not remember the state of the patient's stethoscopic sounds on the next. This prevent accurate and objective diagnosis. If the electronic stethoscope, which can store the stethoscopic sound, is developed, the auscultation will be greatly improved. This study describes an amplifier for electronic stethoscope system that can extract heart sounds of fetus as well as adult and allow us hear and record the sounds. Using the developed stethoscopic amplifier, clean heart sounds of fetus and adult can be heard in noisy environment, such as a consultation room of a university hospital, a laboratory of a university. Surprisingly, the heart sound of a 22-week fetus was heard through the developed electronic stethoscope. Pitch detection experiments using the detected heart sounds showed that the signal represents distinct periodicity. It can be expected that the developed electronic stethoscope can substitute for conventional stethoscopes and if proper analysis method for the stethoscopic signal is developed, a good electronic stethoscope system can be produced. (author). 17 refs., 6 figs.

  20. An Optimized 2.4GHz RF Power Amplifier Performance for WLAN System

    Science.gov (United States)

    Ali, Mohammed H.; Chakrabarty, C. K.; Abdalla, Ahmed N.; Hock, Goh C.

    2013-06-01

    Recently, the design of RF power amplifiers (PAs) for modern wireless systems are faced with a difficult tradeoff for example, cellphone; battery lifetime is largely determined by the power efficiency of the PA and high spectral efficiency which have ability to transmit data at the highest possible rate for a given channel bandwidth. This paper presents the design a multi stage class AB power Amplifier with high power added efficiency (PAE) and acceptable linearity for the WLAN applications. The open-circuited third harmonic control circuit enhances the efficiency of the PA without deteriorating the linearity of class-AB mode of the PA. The voltage and current waveforms are simulated to evaluate the appropriate operation for the modes. The effectiveness of the proposed controller has been verified by comparing proposed method with another methods using simulation study under a variety of conditions. The proposed circuit operation for a WLAN signals delivers a power-added efficiency (PAE) of 37.6% is measured at 31.6-dBm output power while dissipating 34.61 mA from a 1.8V supply. Finally, the proposed PA is show a good and acceptable result for the WLAN system.

  1. Modeling and Optimization of Class-E Amplifier at Subnominal Condition in a Wireless Power Transfer System for Biomedical Implants.

    Science.gov (United States)

    Liu, Hao; Shao, Qi; Fang, Xuelin

    2017-02-01

    For the class-E amplifier in a wireless power transfer (WPT) system, the design parameters are always determined by the nominal model. However, this model neglects the conduction loss and voltage stress of MOSFET and cannot guarantee the highest efficiency in the WPT system for biomedical implants. To solve this problem, this paper proposes a novel circuit model of the subnominal class-E amplifier. On a WPT platform for capsule endoscope, the proposed model was validated to be effective and the relationship between the amplifier's design parameters and its characteristics was analyzed. At a given duty ratio, the design parameters with the highest efficiency and safe voltage stress are derived and the condition is called 'optimal subnominal condition.' The amplifier's efficiency can reach the highest of 99.3% at the 0.097 duty ratio. Furthermore, at the 0.5 duty ratio, the measured efficiency of the optimal subnominal condition can reach 90.8%, which is 15.2% higher than that of the nominal condition. Then, a WPT experiment with a receiving unit was carried out to validate the feasibility of the optimized amplifier. In general, the design parameters of class-E amplifier in a WPT system for biomedical implants can be determined with the proposed optimization method in this paper.

  2. National Ignition Facility system design requirements Laser System SDR002

    International Nuclear Information System (INIS)

    Larson, D.W.; Bowers, J.M.; Bliss, E.S.; Karpenko, V.P.; English, E.

    1996-01-01

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIP Laser System. The Laser System generates and delivers high-power optical pulses to the target chamber, and is composed of all optical puke creating and transport elements from Puke Generation through Final Optics as well as the special equipment that supports, energizes and controls them. The Laser System consists of the following WBS elements: 1.3 Laser System 1.4 Beam Transport System 1.6 Optical Components 1.7 Laser Control 1.8.7 Final Optics

  3. Integrated Circuit Design of 3 Electrode Sensing System Using Two-Stage Operational Amplifier

    Science.gov (United States)

    Rani, S.; Abdullah, W. F. H.; Zain, Z. M.; N, Aqmar N. Z.

    2018-03-01

    This paper presents the design of a two-stage operational amplifier(op amp) for 3-electrode sensing system readout circuits. The designs have been simulated using 0.13μm CMOS technology from Silterra (Malaysia) with Mentor graphics tools. The purpose of this projects is mainly to design a miniature interfacing circuit to detect the redox reaction in the form of current using standard analog modules. The potentiostat consists of several op amps combined together in order to analyse the signal coming from the 3-electrode sensing system. This op amp design will be used in potentiostat circuit device and to analyse the functionality for each module of the system.

  4. Generation of 500-mJ nanosecond pulses from a diode-pumped Yb:YAG TRAM laser amplifier

    Czech Academy of Sciences Publication Activity Database

    Tokita, S.; Divoký, Martin; Furuse, H.; Matsumoto, K.; Nakamura, Y.; Yoshida, M.; Kawashima, T.; Kawanaka, J.

    2014-01-01

    Roč. 4, č. 10 (2014), s. 2122-2126 ISSN 2159-3930 Institutional support: RVO:68378271 Keywords : active-mirror laser * ceramics Subject RIV: BH - Optics, Masers, Laser s Impact factor: 2.844, year: 2014

  5. Design of remote laser-induced fluorescence system's acquisition circuit

    Science.gov (United States)

    Wang, Guoqing; Lou, Yue; Wang, Ran; Yan, Debao; Li, Xin; Zhao, Xin; Chen, Dong; Zhao, Qi

    2017-10-01

    Laser-induced fluorescence system(LIfS) has been found its significant application in identifying one kind of substance from another by its properties even it's thimbleful, and becomes useful in plenty of fields. Many superior works have reported LIfS' theoretical analysis , designs and uses. However, the usual LIPS is always constructed in labs to detect matter quite closely, for the system using low-power laser as excitation source and charge coupled device (CCD) as detector. Promoting the detectivity of LIfS is of much concern to spread its application. Here, we take a high-energy narrow-pulse laser instead of commonly used continuous wave laser to operate sample, thus we can get strong fluorescent. Besides, photomultiplier (PMT) with high sensitivity is adopted in our system to detect extremely weak fluorescence after a long flight time from the sample to the detector. Another advantage in our system, as the fluorescence collected into spectroscopy, multiple wavelengths of light can be converted to the corresponding electrical signals with the linear array multichannel PMT. Therefore, at the cost of high-powered incentive and high-sensitive detector, a remote LIFS is get. In order to run this system, it is of importance to turn light signal to digital signal which can be processed by computer. The pulse width of fluorescence is deeply associated with excitation laser, at the nanosecond(ns) level, which has a high demand for acquisition circuit. We design an acquisition circuit including, I/V conversion circuit, amplifying circuit and peak-holding circuit. The simulation of circuit shows that peak-holding circuit can be one effective approach to reducing difficulty of acquisition circuit.

  6. Construction of an optical semiconductor amplifier starting from a Fabry-Perot semiconductor laser; Construccion de un amplificador optico de semiconductor a partir de un laser de semiconductor Fabry-Perot

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, E.; Soto, H.; Marquez, H.; Valles V, N. [Departamento de Electronica y Telecomunicaciones, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada. Km. 107, Carretera Tijuana-Ensenada, 22860 Ensenada, Baja California (Mexico)

    2000-07-01

    A methodology to convert a semiconductor laser Fabry-Perot (SL-FP) in a semiconductor optical amplifier (SOA) is presented. In order to suppress the cavity resonant an optical thin film coating was deposited on the facets of the SL-FP. The experiment was carried out putting on service a new monitoring technique that consist in the observation of the laser power spectrum during the antireflection coatings deposition. This allows to determine the moment were the facets reflectivity is minimum. The SOA obtained was characterized for different polarization currents. (Author)

  7. Phase locking of a seven-channel continuous wave fibre laser system by a stochastic parallel gradient algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, M V; Garanin, S G; Dolgopolov, Yu V; Kopalkin, A V; Kulikov, S M; Sinyavin, D N; Starikov, F A; Sukharev, S A; Tyutin, S V; Khokhlov, S V; Chaparin, D A [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

    2014-11-30

    A seven-channel fibre laser system operated by the master oscillator – multichannel power amplifier scheme is the phase locked using a stochastic parallel gradient algorithm. The phase modulators on lithium niobate crystals are controlled by a multichannel electronic unit with the microcontroller processing signals in real time. The dynamic phase locking of the laser system with the bandwidth of 14 kHz is demonstrated, the time of phasing is 3 – 4 ms. (fibre and integrated-optical structures)

  8. Analysis and compensation of I/Q imbalance in amplify-and-forward cooperative systems

    KAUST Repository

    Qi, Jian; Aissa, Sonia; Alouini, Mohamed-Slim

    2012-01-01

    In this paper, dual-hop amplify-and-forward (AF) cooperative systems in the presence of in-phase and quadrature-phase (I/Q) imbalance, which refers to the mismatch between components in I and Q branches, are investigated. First, we analyze the performance of the considered AF cooperative protocol without compensation for I/Q imbalance as the benchmark. Furthermore, a compensation algorithm for I/Q imbalance is proposed, which makes use of the received signals at the destination, from the source and relay nodes, together with their conjugations to detect the transmitted signal. The performance of the AF cooperative system under study is evaluated in terms of average symbol error probability (SEP), which is derived considering transmission over Rayleigh fading channels. Numerical results are provided and show that the proposed compensation algorithm can efficiently mitigate the effect of I/Q imbalance. © 2012 IEEE.

  9. Analysis and compensation of I/Q imbalance in amplify-and-forward cooperative systems

    KAUST Repository

    Qi, Jian

    2012-04-01

    In this paper, dual-hop amplify-and-forward (AF) cooperative systems in the presence of in-phase and quadrature-phase (I/Q) imbalance, which refers to the mismatch between components in I and Q branches, are investigated. First, we analyze the performance of the considered AF cooperative protocol without compensation for I/Q imbalance as the benchmark. Furthermore, a compensation algorithm for I/Q imbalance is proposed, which makes use of the received signals at the destination, from the source and relay nodes, together with their conjugations to detect the transmitted signal. The performance of the AF cooperative system under study is evaluated in terms of average symbol error probability (SEP), which is derived considering transmission over Rayleigh fading channels. Numerical results are provided and show that the proposed compensation algorithm can efficiently mitigate the effect of I/Q imbalance. © 2012 IEEE.

  10. Development of a high power femtosecond laser

    CSIR Research Space (South Africa)

    Neethling, PH

    2010-10-01

    Full Text Available The Laser Research Institute and the CSIR National Laser Centre are developing a high power femtosecond laser system in a joint project with a phased approach. The laser system consists of an fs oscillator and a regenerative amplifier. An OPCPA...

  11. Study of the transverse lasing in big size crystals of Ti:Sa. Application to the design of the peta-watt high-energy amplifier of the pilot laser of the LASERIX facility; Etude de l'amplification parasite transverse de la fluorescence dans les cristaux de Ti:Sa de grandes dimensions. Application a la realisation de l'amplificateur petawatt haute energie du laser pilote de la station LASERIX

    Energy Technology Data Exchange (ETDEWEB)

    Ple, F

    2007-11-15

    This manuscript presents experimental and theoretical works accomplished for the development of the LASERIX laser driver. The main goal of this thesis work was to design a high energy and high repetition rate titanium doped sapphire amplifier (Ti:Sa) allowing to reach an energy of 40 J at a repetition rate of 0.1 Hz before compression. After a general description of amplification in chirped pulse amplification Ti:Sa laser systems (Chapter 1), I present the two particular developments we made during this work for high energy amplification (Chapter 2). First, the spatial shaping and the homogenization based on micro-lens array (MLA) systems of the eight Nd-Glass pump lasers dedicated to the pumping of the last booster amplifier.Secondly, the suppression of parasitic effects due to transverse amplification of the fluorescence in the last booster amplifier Ti:Sa crystal. The developments performed as part of this thesis allowed us to amplify an impulsion of 2 J of energy up to 39 J in a crystal of 10 cm diameter. I also present the simulation program I developed (Chapter 3) in order to simulate the three dimensional parasitic lasing effect and fluorescence transverse amplification phenomena in large Ti:Sa crystals. A parametric study of these parasitic effects is also presented. Finally, the last part of this manuscript (Chapter 4) gives prospects of this work as part of the large future ELI and ILE projects. (author)

  12. Circuit Design and Implementation of Micro-Displacement Measurement System of Laser Self-Mixing Interference

    Directory of Open Access Journals (Sweden)

    Guang Ya LIU

    2014-02-01

    Full Text Available In this paper we put forward the basic structure of a micro-displacement measuring system based on the basic theory of laser feedback, and designed a hardware circuit of the system, including the LD driver and modulation circuit, photoelectric signal amplifier and filter circuit, which meet the requirements of the follow-up experimental study by theoretical analysis and Multisim simulation to the circuit.

  13. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures

  14. The Theory of Random Laser Systems

    International Nuclear Information System (INIS)

    Xunya Jiang

    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 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

  15. FULL ELECTROMAGNETIC SIMULATION OF FREE-ELECTRON LASER AMPLIFIER PHYSICS VIA THE LORENTZ-BOOSTED FRAME APPROACH

    International Nuclear Information System (INIS)

    Fawley, William M.; Vay, Jean-Luc

    2009-01-01

    Numerical simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. A particularly good example is that of short wavelength free-electron lasers (FELs) in which a high energy electron beam interacts with a static magnetic undulator. In the optimal boost frame with Lorentz factor gamma F , the red-shifted FEL radiation and blue shifted undulator have identical wavelengths and the number of required time-steps (presuming the Courant condition applies) decreases by a factor of 2(gamma F )**2 for fully electromagnetic simulation. We have adapted the WARP code to apply this method to several FEL problems involving coherent spontaneous emission (CSE) from pre-bunched ebeams, including that in a biharmonic undulator.

  16. Pump RIN-induced impairments in unrepeatered transmission systems using distributed Raman amplifier.

    Science.gov (United States)

    Cheng, Jingchi; Tang, Ming; Lau, Alan Pak Tao; Lu, Chao; Wang, Liang; Dong, Zhenhua; Bilal, Syed Muhammad; Fu, Songnian; Shum, Perry Ping; Liu, Deming

    2015-05-04

    High spectral efficiency modulation format based unrepeatered transmission systems using distributed Raman amplifier (DRA) have attracted much attention recently. To enhance the reach and optimize system performance, careful design of DRA is required based on the analysis of various types of impairments and their balance. In this paper, we study various pump RIN induced distortions on high spectral efficiency modulation formats. The vector theory of both 1st and higher-order stimulated Raman scattering (SRS) effect using Jones-matrix formalism is presented. The pump RIN will induce three types of distortion on high spectral efficiency signals: intensity noise stemming from SRS, phase noise stemming from cross phase modulation (XPM), and polarization crosstalk stemming from cross polarization modulation (XPolM). An analytical model for the statistical property of relative phase noise (RPN) in higher order DRA without dealing with complex vector theory is derived. The impact of pump RIN induced impairments are analyzed in polarization-multiplexed (PM)-QPSK and PM-16QAM-based unrepeatered systems simulations using 1st, 2nd and 3rd-order forward pumped Raman amplifier. It is shown that at realistic RIN levels, negligible impairments will be induced to PM-QPSK signals in 1st and 2nd order DRA, while non-negligible impairments will occur in 3rd order case. PM-16QAM signals suffer more penalties compared to PM-QPSK with the same on-off gain where both 2nd and 3rd order DRA will cause non-negligible performance degradations. We also investigate the performance of digital signal processing (DSP) algorithms to mitigate such impairments.

  17. [A Methane Detection System Using Distributed Feedback Laser at 1 654 nm].

    Science.gov (United States)

    Li, Bin; Liu, Hui-fang; He, Qi-xin; Zhai, Bing; Pan, Jiao-qing; Zheng, Chuan-tao; Wang, Yi-ding

    2016-01-01

    A methane (CH4) detection system based on tunable diode laser absorption spectroscopy (TDLAS) technique was experimentally demonstrated. A distributed feedback (DFB) laser around 1 654 nm, an open reflective sensing probe and two InGaAs photodiodes were adopted in the system. The electrical part of the system mainly includes the laser temperature control & modulation module and the orthogonal lock-in amplifier module. Temperature and spectrum tests on the DFB laser indicate that, the laser temperature fluctuation can be limited to the range of -0.02-0.02 degrees C, the laser's emitting wavelength varies linearly with the temperature and injection current, and also good operation stability of the laser was observed through experiments. Under a constant working temperature, the center wavelength of the laser is varied linearly by adjusting the driving current. Meanwhile, a 5 kHz sine wave signal and a 10 Hz saw wave signal were provided by the driving circuit for the harmonic extraction purpose. The developed orthogonal lock-in amplifier can extract the If and 2f harmonic signals with the extraction error of 3.55% and 5% respectively. By using the open optical probe, the effective optical pass length was doubled to 40 cm. Gas detection experiment was performed to derive the relation between the harmonic amplitude and the gas concentration. As the concentration increases from 1% to 5%, the amplitudes of the 1f harmonic and the 2f harmonic signal were obtained, and good linear ration between the concentration and the amplitude ratio was observed, which proves the normal function of the developed detection system. This system is capable to detect other trace gases by using relevant DFB lasers.

  18. A 12 GHz wavelength spacing multi-wavelength laser source for wireless communication systems

    Science.gov (United States)

    Peng, P. C.; Shiu, R. K.; Bitew, M. A.; Chang, T. L.; Lai, C. H.; Junior, J. I.

    2017-08-01

    This paper presents a multi-wavelength laser source with 12 GHz wavelength spacing based on a single distributed feedback laser. A light wave generated from the distributed feedback laser is fed into a frequency shifter loop consisting of 50:50 coupler, dual-parallel Mach-Zehnder modulator, optical amplifier, optical filter, and polarization controller. The frequency of the input wavelength is shifted and then re-injected into the frequency shifter loop. By re-injecting the shifted wavelengths multiple times, we have generated 84 optical carriers with 12 GHz wavelength spacing and stable output power. For each channel, two wavelengths are modulated by a wireless data using the phase modulator and transmitted through a 25 km single mode fiber. In contrast to previously developed schemes, the proposed laser source does not incur DC bias drift problem. Moreover, it is a good candidate for radio-over-fiber systems to support multiple users using a single distributed feedback laser.

  19. A flexible receiver with fiber optical parametric amplifier in OCDMA-FSO communication system

    Science.gov (United States)

    Xia, Min; Yuan, Jin-hui; Sang, Xin-zhu; Yin, Xiao-li; Rao, Lan; Yu, Chong-xiu

    2014-11-01

    A new receiver is proposed, which uses the fiber optical parametric amplifier (FOPA) in optical code division multiple access (OCDMA) over free space optic (FSO) communication system. The noise tolerance as the performance index in this receiver is derived. The receiver can not only improve the noise tolerance but also change the pump data conveniently for adapting to the length variation of the coding sequence under a complex and fast-changing weather condition. The influence of different factors on the noise tolerance is analyzed, and a significant improvement of about 18.77 dB for the noise tolerance can be achieved when the pump power and the length of coding sequence are 5 W and 256, respectively.

  20. Simultaneous Wireless Information and Power Transfer for MIMO Amplify-and-Forward Relay Systems

    KAUST Repository

    Benkhelifa, Fatma; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we investigate the simultaneous wireless information and power transfer (SWIPT) for the two-hop Multiple-Input Multiple-Output (MIMO) Amplify-and-Forward (AF) relay communication systems with the multiantenna energy harvesting relay. We derive the optimal source and relay covariance matrices to characterize the achievable region between the sourcedestination rate and the harvested energy at the relay, namely Rate-Energy (R-E) region. In this context, we consider the ideal scenario where the energy harvester (EH) receiver and the information decoder (ID) receiver at the relay can simultaneously decode the information and harvest the energy at the relay. Then, we consider more practical schemes which are the power splitting (PS) and the time switching (TS) which separate the EH and ID transfer over the power domain and the time domain, respectively.

  1. Simultaneous Wireless Information and Power Transfer for MIMO Amplify-and-Forward Relay Systems

    KAUST Repository

    Benkhelifa, Fatma

    2016-01-06

    In this paper, we investigate the simultaneous wireless information and power transfer (SWIPT) for the two-hop Multiple-Input Multiple-Output (MIMO) Amplify-and-Forward (AF) relay communication systems with the multiantenna energy harvesting relay. We derive the optimal source and relay covariance matrices to characterize the achievable region between the sourcedestination rate and the harvested energy at the relay, namely Rate-Energy (R-E) region. In this context, we consider the ideal scenario where the energy harvester (EH) receiver and the information decoder (ID) receiver at the relay can simultaneously decode the information and harvest the energy at the relay. Then, we consider more practical schemes which are the power splitting (PS) and the time switching (TS) which separate the EH and ID transfer over the power domain and the time domain, respectively.

  2. Stability of a 500 km erbium-doped fiber amplifier cascade

    DEFF Research Database (Denmark)

    Lumholt, Ole; Bjarklev, Anders Overgaard; Povlsen, Jørn Hedegaard

    1992-01-01

    The stability of a cascade system of erbium-doped fiber amplifiers, due to pump and signal power variations, has been examined by use of a very accurate model. Even with an automatic gain control loop included, a fallout of a pump laser in the first inline amplifier is shown to produce a more than...

  3. Study on the drive laser system of the photocathode-injector used in high gain FEL

    CERN Document Server

    Lu Xiang Yang; Zhao Kui; Wang Li; Quan Sheng Wen; Hao Jian Kui; Zhang Bao Cheng; Chen J

    2002-01-01

    High gain FEL requires high quality electron beam which can be provided only by the RF photocathode gun. The drive laser for electron source plays the key role. In Institute of Heavy Ion Physics of Beijing University, the laser system is required to deliver a 500 mu J, 6-8 ps pulse of UV photons (260 nm) to the cathode. This system mainly consists of a CW, frequency-doubled, diode-pumped Nd:YAG laser, which provides energy to pump a CW mode-locked Ti:sapphire oscillator, Q-switched Nd:YaG pump lasers, a regenerative amplifier and harmonics crystals. To meet the low jitters of pulses (1.0 ps), cavity length of the oscillator should be adjustable to lock the pulse frequency with external RF reference, and a phase stability feedback system is also used

  4. Multi-terawatt fusion laser systems

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1993-01-01

    The evolution of laser fusion systems started with a description of the basic principles of the laser in 1959, then a physical demonstration showing 1000 Watts of peak optical power in 1961 to the present systems that deliver 10 14 watts of peak optical power, are presented. Physical limits to large systems are reviewed: thermal limits, material stress limits, structural limits and stability, parasitic coupling, measurement precision and diagnostics. The various steps of the fusion laser-system development process are then discussed through an historical presentation. 3 figs., 8 refs

  5. Petawatt laser system for fast ignitor studies at ILE, Osaka University

    International Nuclear Information System (INIS)

    Izawa, Y.; Kitagawa, Y.; Fujita, H.

    2003-01-01

    A petawatt laser system has been developed for the fast ignitor studies. Three new technologies were introduced; an optical parametric chirped pulse amplifier (OPCPA) in the front end for suppression of prepulse below 10 -8 the main pulse, a deformable mirror for correction of wave front distortion and the chirped pulse amplification in the GEKKO-XII. The system delivered successfully the output energy of 420 J in 470 fs on target, which corresponds to the focal intensity of more than 10 20 W/cm 2 . By using the PW laser, the heating experiments of the high density plasma imploded by GEKKO-XII started. (author)

  6. Infrared laser scattering system for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Muraoka, K; Hiraki, N; Kawasaki, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1975-05-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO/sub 2/ laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO/sub 2/ laser and the preparations of the optical components have been started and some preliminary results of these are described.

  7. Infrared laser scattering system for plasma diagnostics

    International Nuclear Information System (INIS)

    Muraoka, Katsunori; Hiraki, Naoji; Kawasaki, Shoji

    1975-01-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO 2 laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO 2 laser and the preparations of the optical components have been started and some preliminary results of these are described. (auth.)

  8. Multitube coaxial closed cycle gas laser system

    International Nuclear Information System (INIS)

    Davis, J.W.; Walch, A.P.

    1975-01-01

    A gas laser design capable of long term reliable operation in a commercial environment is disclosed. Various construction details which insulate the laser optics from mechanical distortions and vibrations inevitably present in the environment are developed. Also, a versatile optical cavity made up of modular units which render the basic laser configuration adaptable to alternate designs with different output capabilities is shown in detail. The system built around a convection laser operated in a closed cycle and the working medium is a gas which is excited by direct current electric discharges. (auth)

  9. FLUIDIC AC AMPLIFIERS.

    Science.gov (United States)

    Several fluidic tuned AC Amplifiers were designed and tested. Interstage tuning and feedback designs are considered. Good results were obtained...corresponding Q’s as high as 12. Element designs and test results of one, two, and three stage amplifiers are presented. AC Modulated Carrier Systems

  10. Laser systems with diamond optical elements

    International Nuclear Information System (INIS)

    Seitz, J.R.

    1975-01-01

    High power laser systems with optical elements of diamond having a thermal conductivity of at least 10 W/cm. 0 K at 300 0 K and an optical absorption at the laser beam wavelength of no more than 10 to 20 percent are described. (U.S.)

  11. Blue laser phase change recording system

    International Nuclear Information System (INIS)

    Hofmann, Holger; Dambach, S.Soeren; Richter, Hartmut

    2002-01-01

    The migration paths from DVD phase change recording with red laser to the next generation optical disk formats with blue laser and high NA optics are discussed with respect to optical aberration margins and disc capacities. A test system for the evaluation of phase change disks with more than 20 GB capacity is presented and first results of the recording performance are shown

  12. 32-core Inline Multicore Fiber Amplifier for Dense Space Division Multiplexed Transmission Systems

    DEFF Research Database (Denmark)

    Jain, S.; Mizuno, T.; Jung, Y.

    2016-01-01

    We present a high-core-count SDM amplifier, i.e. 32-core multicore-fiber amplifier, in a cladding-pumped configuration. An average gain of 17dB and NF of 7dB is obtained for -5dBm input signal power in the wavelength range 1544nm-1564nm....

  13. Design and performance of the main amplifier system for the National Ignition Facility

    International Nuclear Information System (INIS)

    Beullier, J; Erlandson, A; Grebot, E; Guenet, J; Guenet, M; Horvath, J; Jancaitis, K; Larson, D; Lawson, J; LeTouze, G; Maille, X; Manes, K; Marshall, C; Mengue, T; Moor, E; Payne, S; Pedrotti, L; Rotter, M; Seznec, S; Sutton, S; Zapata, L.

    1999-01-01

    This paper describes the design and performance of flashlamp-pumped, Nd:glass. Brewster-angle slab amplifiers intended to be deployed in the National Ignition Facility (NIF). To verify performance, we tested a full-size, three-slab-long, NIF prototype amplifier, which we believe to be the largest flashlamp-pumped Nd:glass amplifier ever assembled. Like the NIF amplifier design, this prototype amplifier had eight 40-cm-square apertures combined in a four-aperture-high by two-aperture-wide matrix. Specially-shaped reflectors, anti-reflective coatings on the blastshields, and preionized flashlamps were used to increase storage efficiency. Cooling gas was flowed over the flashlamps to remove waste pump heat and to accelerate thermal wavefront recovery. The prototype gain results are consistent with model predictions and provide high confidence in the final engineering design of the NIF amplifiers. Although the dimensions, internal positions, and shapes of the components in the NIF amplifiers will be slightly different from the prototype, these differences are small and should produce only slight differences in amplifier performance

  14. Operation Amplifier

    NARCIS (Netherlands)

    Tetsuya, Saito; Nauta, Bram

    2011-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a

  15. Operation Amplifier

    NARCIS (Netherlands)

    Tetsuya, S.; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. ; SOLUTION: The operation amplifier comprises: a

  16. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  17. Amplifier Distortion

    Science.gov (United States)

    Keeports, David

    2006-12-01

    By definition, a high fidelity amplifier's instantaneous output voltage is directly proportional to its instantaneous input voltage. While high fidelity is generally valued in the amplification of recorded music, nonlinearity, also known as distortion, is desirable in the amplification of some musical instruments. In particular, guitar amplifiers exploit nonlinearity to increase both the harmonic content and sustain of a guitar's sound. I will discuss how both modifications in sound result from saturation of triode tubes and transistors. Additionally, I will describe the difference in the symmetry of saturation curves for transistors and tubes and the reason why tube guitar amplifiers are generally considered to be superior to solid-state amplifiers. Finally, I will discuss attempts to use solid-state electronics to replicate the sound of tube amplifiers.

  18. 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.

  19. A Large Aperture, High Energy Laser System for Optics and Optical Component Testing

    International Nuclear Information System (INIS)

    Nostrand, M.C.; Weiland, T.L.; Luthi, R.L.; Vickers, J.L.; Sell, W.D.; Stanley, J.A.; Honig, J.; Auerbach, J.; Hackel, R.P.; Wegner, P.J.

    2003-01-01

    A large aperture, kJ-class, multi-wavelength Nd-glass laser system has been constructed at Lawrence Livermore National Lab which has unique capabilities for studying a wide variety of optical phenomena. The master-oscillator, power-amplifier (MOPA) configuration of this ''Optical Sciences Laser'' (OSL) produces 1053 nm radiation with shaped pulse lengths which are variable from 0.1-100 ns. The output can be frequency doubled or tripled with high conversion efficiency with a resultant 100 cm 2 high quality output beam. This facility can accommodate prototype hardware for large-scale inertial confinement fusion lasers allowing for investigation of integrated system issues such as optical lifetime at high fluence, optics contamination, compatibility of non-optical materials, and laser diagnostics

  20. Threshold-based detection for amplify-and-forward cooperative communication systems with channel estimation error

    KAUST Repository

    Abuzaid, Abdulrahman I.

    2014-09-01

    Efficient receiver designs for cooperative communication systems are becoming increasingly important. In previous work, cooperative networks communicated with the use of $L$ relays. As the receiver is constrained, it can only process $U$ out of $L$ relays. Channel shortening and reduced-rank techniques were employed to design the preprocessing matrix. In this paper, a receiver structure is proposed which combines the joint iterative optimization (JIO) algorithm and our proposed threshold selection criteria. This receiver structure assists in determining the optimal $U-{opt}$. Furthermore, this receiver provides the freedom to choose $U ≤ U-{opt}$ for each frame depending upon the tolerable difference allowed for mean square error (MSE). Our study and simulation results show that by choosing an appropriate threshold, it is possible to gain in terms of complexity savings without affecting the BER performance of the system. Furthermore, in this paper the effect of channel estimation errors is investigated on the MSE performance of the amplify-and-forward (AF) cooperative relaying system.

  1. Nuclear criticality safety and time reactivity enhancement aspects of energy amplifier system devices

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, F [ENEA, Centro Ricerche Trisaia, Rotondelle, Matera (Italy). Direzione INFO

    1995-12-01

    As far as the Rubbia`s and colleagues proposal of innovating Energy Amplifier system (E.A.s.) device driven by a particle beam accelerator is concerned, four basic topics are comprised in the present paper: (1) A short outline of the nuclear aspects of Th-U and U-Pu fuel cycles regarding their general breeding and efficiency features. (2) The needed nuclear criticality control requirements have been studied in terms of safety regulating parameters on the basis of the ThO2 mixed oxides selected as fuel kind for the E.A.s. device technology development. Particular attention is devoted to time evolution of neutron multiplication factor since delayed development of the 233U buildup and so system reactivity are expected in the Th-U cycle. (3) Code E.A.s. device irradiation and post-irradiation modelling for determining higher actinides buildup, fission products formation and fuel consumption trends as function of time, system enrichment degree and flux level parameters. (4) The confirmation, on the basis of the same specific power irradiation, of expected actinides waste obtainment cleaner than the one deriving from the U-Pu cycle utilization. For this end, a model comparison of equivalent enriched fissile nuclides in both cycles has been devised as having, within the range of 0-700 days, ten irradiation periods of about 53 MW/ton specific power and equivalent cooling time post-irradiation periods.

  2. Design of a power amplifier for the LAMPF proton storage ring transverse damper system

    International Nuclear Information System (INIS)

    Lunsford, J.S.

    1981-01-01

    A power amplifier has been designed to drive the 50-Ω stripline deflection structures in the transverse active damper of the Los Alamos 800-MeV Proton Storage Ring (PSR). The unit will provide 600-V peak-to-peak with a dc-to-100-MHz bandwidth. Other important characteristics include < 40-ns delay time, 50-dB voltage gain, and 4-ns risetime with < 5% overshoot and ringing. Because of the current-drive properties of the amplifier, two amplifiers could be combined to provide over 1000-V peak-to-peak into 50 Ω, with very little bandwidth degradation. Components in the power amplifier that represent new designs are a 20-tube distributed-amplifier output stage; a driver stage, using VMOS FET and bipolar transistors; a high-voltage probe, with good dc stability and 150-MHz bandwidth; a transient suppressor circuit, using PIN diodes to protect the transistorized drivers from tube arcing; a nonlinear amplifier to compensate for the nonlinear characteristics of the distributed amplifier; and a first-fail indicator circuit to aid in locating the prime causes of equipment failures

  3. 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.

  4. 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

  5. Robust Power Allocation for Multi-Carrier Amplify-and-Forward Relaying Systems

    KAUST Repository

    Rao, Anlei

    2012-09-08

    It has been shown that adaptive power allocation can provide a substantial performance gain in wireless communication systems when perfect channel state information (CSI) is available at the transmitter. However when only imperfect CSI is available, the performance may degrade significantly, and as such robust power allocation schemes have been developed to minimize the effects of this degradation. In this paper, we investigate power allocation strategies for multicarrier systems, in which each subcarrier employs single amplify-and-forward (AF) relaying scheme. Optimal power allocation schemes are proposed by maximizing the approximated channel capacity under aggregate power constraint (APC) and separate power constraint (SPC). By comparison with the uniform power allocation scheme and the best channel power allocation scheme, we confirm that both the APC and SPC schemes achieve a performance gain over benchmark schemes. In addition, the impact of channel uncertainty is also considered in this paper by modeling the uncertainty regions as bounded sets, and results show that the uncertainty can degrade the worst-case performance significantly.

  6. Minimizing the symbol-error-rate for amplify-and-forward relaying systems using evolutionary algorithms

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2015-02-01

    In this paper, a new detector is proposed for an amplify-and-forward (AF) relaying system. The detector is designed to minimize the symbol-error-rate (SER) of the system. The SER surface is non-linear and may have multiple minimas, therefore, designing an SER detector for cooperative communications becomes an optimization problem. Evolutionary based algorithms have the capability to find the global minima, therefore, evolutionary algorithms such as particle swarm optimization (PSO) and differential evolution (DE) are exploited to solve this optimization problem. The performance of proposed detectors is compared with the conventional detectors such as maximum likelihood (ML) and minimum mean square error (MMSE) detector. In the simulation results, it can be observed that the SER performance of the proposed detectors is less than 2 dB away from the ML detector. Significant improvement in SER performance is also observed when comparing with the MMSE detector. The computational complexity of the proposed detector is much less than the ML and MMSE algorithms. Moreover, in contrast to ML and MMSE detectors, the computational complexity of the proposed detectors increases linearly with respect to the number of relays.

  7. Switched diversity strategies for dual-hop amplify-and-forward relaying systems

    KAUST Repository

    Gaaloul, Fakhreddine; Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

    2012-01-01

    This study investigates different receive single-branch switch-based diversity schemes for dual-hop amplify-and-forward relaying networks. Specifically, three receive processing algorithms are adopted, in which the receive branch is selected using

  8. An auxiliary frequency tracking system for general purpose lock-in amplifiers

    Science.gov (United States)

    Xie, Kai; Chen, Liuhao; Huang, Anfeng; Zhao, Kai; Zhang, Hanlu

    2018-04-01

    Lock-in amplifiers (LIAs) are designed to measure weak signals submerged by noise. This is achieved with a signal modulator to avoid low-frequency noise and a narrow-band filter to suppress out-of-band noise. In asynchronous measurement, even a slight frequency deviation between the modulator and the reference may lead to measurement error because the filter’s passband is not flat. Because many commercial LIAs are unable to track frequency deviations, in this paper we propose an auxiliary frequency tracking system. We analyze the measurement error caused by the frequency deviation and propose both a tracking method and an auto-tracking system. This approach requires only three basic parameters, which can be obtained from any general purpose LIA via its communications interface, to calculate the frequency deviation from the phase difference. The proposed auxiliary tracking system is designed as a peripheral connected to the LIA’s serial port, removing the need for an additional power supply. The test results verified the effectiveness of the proposed system; the modified commercial LIA (model SR-850) was able to track the frequency deviation and continuous drift. For step frequency deviations, a steady tracking error of less than 0.001% was achieved within three adjustments, and the worst tracking accuracy was still better than 0.1% for a continuous frequency drift. The tracking system can be used to expand the application scope of commercial LIAs, especially for remote measurements in which the modulation clock and the local reference are separated.

  9. Dead time effects from linear amplifiers and discriminators in single detector systems

    International Nuclear Information System (INIS)

    Funck, E.

    1986-01-01

    The dead-time losses originating from a linear amplifier combined with a discriminator for pulse-height selection are investigated. Measurements are carried out to determine the type of dead time represented by the amplifier-discriminator combination. The corrections involved by feeding the discriminator output pulses into an electronic module producing a blocking time are discussed and practical hints are given to reduce them. (orig.)

  10. 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.

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

    International Nuclear Information System (INIS)

    Wissmann, Laurens-Georg

    2012-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Wissmann, Laurens-Georg

    2012-08-15

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

  13. An ultra-long cavity passively mode-locked fiber laser based on nonlinear polarization rotation in a semiconductor optical amplifier

    International Nuclear Information System (INIS)

    Liu, Tonghui; Jia, Dongfang; Yang, Jingwen; Chen, Jiong; Wang, Zhaoying; Yang, Tianxin

    2013-01-01

    In this paper we investigate an ultra-long cavity passively mode-locked fiber laser based on a semiconductor optical amplifier (SOA). Experimental results are presented which indicate that stable mode-locked pulses can be obtained by combining nonlinear polarization rotation (NPR) in the SOA with a polarization controller. By adding a 4 km single mode fiber into the ring cavity, a stable fundamental-order mode-locked pulse train with a repetition rate of 50.72 kHz is generated through the NPR effect in the SOA. The central wavelength, 3 dB bandwidth and single pulse energy of the output pulse are 1543.95 nm, 1.506 nm and 33.12 nJ, respectively. Harmonic mode-locked pulses are also observed in experiments when the parameters are chosen properly. (paper)

  14. 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 ...

  15. NIF/LMJ prototype amplifier mechanical design

    International Nuclear Information System (INIS)

    Horvath, J.

    1996-10-01

    Amplifier prototypes for the National Ignition Facility and the Laser Megajoule will be tested at Lawrence Livermore National Laboratory. The prototype amplifier, which is an ensemble of modules from LLNL and Centre d'Etudes de Limeil-Valenton, is cassette-based with bottom access for maintenance. A sealed maintenance transfer vehicle which moves optical cassettes between the amplifier and the assembly cleanroom, and a vacuum gripper which holds laser slabs during cassette assembly will also be tested. The prototype amplifier will be used to verify amplifier optical performance, thermal recovery time, and cleanliness of mechanical operations

  16. Guided Wave Sensing In a Carbon Steel Pipe Using a Laser Vibrometer System

    Science.gov (United States)

    Ruíz Toledo, Abelardo; Salazar Soler, Jordi; Chávez Domínguez, Juan Antonio; García Hernández, Miguel Jesús; Turó Peroy, Antoni

    2010-05-01

    Non-Destructive Evaluation (NDE) techniques have achieved a great development during the last decades as a valuable tool for material characterization, manufacturing control and structural integrity tests. Among these tools, the guided wave technology has been rapidly extended because it reduces inspection time and costs compared to the ordinary point by point testing in large structures, as well as because of the possibility of inspecting under insulation and coating conditions. This fast development has motivated the creation of several inspection and material characterization systems including different technologies which can be combined with this technique. Different measurements systems based on laser techniques have been presented in order to inspect pipes, plates and diverse structures. Many of them are experimental systems of high cost and complexity which combine the employment of a laser for generation of waves in the structure and an interferometer for detection. Some of them employ air-coupled ultrasound generation transducers, with high losses in air and which demand high energy for exciting waves in materials of high stiffness. The combined employment of a commercial vibrometer system for Lamb wave sensing in plates has been successfully shown in the literature. In this paper we present a measurement system based on the combined employment of a piezoelectric wedge transducer and a laser vibrometer to sense guided acoustic waves in carbon steel pipes. The measurement system here presented is mainly compounded of an angular wedge transducer, employed to generate the guided wave and a commercial laser vibrometer used in the detection process. The wedge transducer is excited by means of a signal function generator whose output signal has been amplified with a power signal amplifier. A high precision positioning system is employed to place the laser beam at different points through the pipe surface. The signal detected by the laser vibrometer system is

  17. Switched diversity strategies for dual-hop amplify-and-forward relaying systems

    KAUST Repository

    Gaaloul, Fakhreddine

    2012-01-01

    This study investigates different receive single-branch switch-based diversity schemes for dual-hop amplify-and-forward relaying networks. Specifically, three receive processing algorithms are adopted, in which the receive branch is selected using the arbitrary selection algorithm, the switching algorithm, or the switching algorithm with post-examining best branch selection. The identification of the receive branch is carried out for two different system models. For the first model, a single-antenna relaying station is used in conjunction with a multiple-antenna transceiver, where the processing is performed independently of the first hop-fading conditions. The second model suggests the use of parallel deployment of single-antenna relays to transfer information from a multiple-antenna transmitter to a single-antenna receiver, where the active relaying station is determined based on the pre-combining end-to-end fading conditions. Performance comparisons for various transmission scenarios on the first hop are presented using new formulations for the statistics of the combined signal-to-noise ratio. Simulation results are also provided to validate the mathematical development and to verify the numerical computations. © 2012 The Institution of Engineering and Technology.

  18. Simultaneous Wireless Information and Power Transfer for MIMO Amplify-and-Forward Relay Systems

    KAUST Repository

    Benkhelifa, Fatma

    2016-03-28

    © 2015 IEEE. In this paper, we investigate two-hop Multiple- Input Multiple-Output (MIMO) Amplify-and-Forward (AF) relay communication systems with simultaneous wireless information and power transfer (SWIPT) at the multi-antenna energy harvesting relay. We derive the optimal source and relay covariance matrices to characterize the achievable region between the source-destination rate and the harvested energy at the relay, namely Rate-Energy (R-E) region. In this context, we consider the ideal scenario where the energy harvester (EH) receiver and the information decoder (ID) receiver at the relay can simultaneously decode the information and harvest the energy at the relay. This scheme provides an outer bound for the achievable R-E region since practical energy harvesting circuits are not yet able to harvest the energy and decode the information simultaneously. Then, we consider more practical schemes which are the power splitting (PS) and the time switching (TS) proposed in [1] and which separate the EH and ID transfer over the power domain and the time domain, respectively. In our study, we derive the boundary of the achievable R- E region and we show the effect of the source transmit power, the relay transmit power and the position of the relay between the source and the destination on the achievable R-E region for the ideal scenario and the two practical schemes.

  19. Switched 4-to-1 Transimpedance Combining Amplifier for Receiver Front-End Circuit of Static Unitary Detector-Based LADAR System

    Directory of Open Access Journals (Sweden)

    Eun-Gyu Lee

    2017-07-01

    Full Text Available Laser detection and ranging (LADAR systems are commonly used to acquire real-time three-dimensional (3D images using the time-of-flight of a short laser pulse. A static unitary detector (STUD-based LADAR system is a simple method for obtaining real-time high-resolution 3D images. In this study, a switched 4-to-1 transimpedance combining amplifier (TCA is implemented as a receiver front-end readout integrated circuit for the STUD-based LADAR system. The 4-to-1 TCA is fabricated using a standard 0.18 μm complementary metal-oxide-semiconductor (CMOS technology, and it consists of four independent current buffers, a two-stage signal combiner, a balun, and an output buffer in one single integrated chip. In addition, there is a switch on each input current path to expand the region of interest with multiple photodetectors. The core of the TCA occupies an area of 92 μm × 68 μm, and the die size including I/O pads is 1000 μm × 840 μm. The power consumption of the fabricated chip is 17.8 mW for a supplied voltage of 1.8 V and a transimpedance gain of 67.5 dBΩ. The simulated bandwidth is 353 MHz in the presence of a 1 pF photodiode parasitic capacitance for each photosensitive cell.

  20. Large laser system facility design

    International Nuclear Information System (INIS)

    Gilmartin, T.J.

    1983-01-01

    Optical stability of foundations and support structures, environmental control, close-in subsystem integration, spatial organization, materiel flow and access to remote subsystems is discussed and compared for four laser facilities: The Special Isotope Separation Laboratory, Argus, Shiva/Nova, and Firepond

  1. 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...

  2. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    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...... 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...

  3. Acquisition of an All-Solid State Femtosecond Laser System

    National Research Council Canada - National Science Library

    Apkarian, V

    2003-01-01

    ... of 160 fs, 800mW, at 1KHz. The output of the pump laser is split successively with 50% beam splitters, to use 200 mW beams to pump two home-built Non-collinear Optical Parametric Amplifiers (NOPA...

  4. Wavefront compensation applied to AVLIS laser systems

    International Nuclear Information System (INIS)

    Gonsiorowski, T.; Wirth, A.

    1995-01-01

    The efficiency of an AVLIS system depends upon the power density and uniformity of the laser system. Because of wavefront aberrations the realized beam quality is not ideal. Wavefront compensation provides a means to improve beam quality and system efficiency. (author)

  5. High Extinction Ratio In-Fibre Polarisers by Exploiting Tilted Fibre Bragg Grating Structures for Single-Polarisation High-Power Fibre Lasers and Amplifiers

    Science.gov (United States)

    2009-11-01

    maintaining (PM) fibre, utilising polarisation hole-burning ( PHB ) effect to reduce homogeneous linewidth of the EDFL. In our work, we demonstrate a stable...loss filter which will induce some loss to the cavity around its paired attenuation band region, thus imposing PHB effect to the gain medium. The...polarisation-hole-burning ( PHB ) effect to realise multi-wavelength switchable function in proposed fibre ring laser system. In the proposed fibre ring laser

  6. Assembly and maintenance of full scale NIF amplifiers in the amplifier module prototype laboratory (AMPLAB)

    International Nuclear Information System (INIS)

    Horvath, J. A.

    1998-01-01

    Mechanical assembly and maintenance of the prototype National Ignition Facility amplifiers in the Amplifier Module Prototype Laboratory (AMPLAB) at Lawrence Livermore National Laboratory requires specialized equipment designed to manipulate large and delicate amplifier components in a safe and clean manner. Observations made during the operation of this assembly and maintenance equipment in AMPLAB provide design guidance for similar tools being built for the National Ignition Facility. Fixtures used for amplifier frame installation, laser slab and flashlamp cassette assembly, transport, and installation, and in-situ blastshield exchange are presented. Examples include a vacuum slab gripper, slab handling clean crane, slab cassette assembly fixture, sealed transport vehicle for slab cassette movement between the cleanroom and amplifier, slab cassette transfer fixture between the cleanroom and transport vehicle, and equipment needed for frame assembly unit, blastshield, an d flashlamp cassette installation and removal. The use of these tools for amplifier assembly, system reconfiguration, reflector replacement, and recovery from an abnormal occurrence such as a flashlamp explosion is described. Observations are made on the design and operation of these tools and their contribution to the final design

  7. Robotic Laser Coating Removal System

    Science.gov (United States)

    2008-07-01

    using a transverse excitation at atmospheric pressure (TEA) method. o Excimer lasers use reactive gases, such as chlorine and fluorine , mixed with... Varnish , and Related Products on Test Panels.   All topcoats were applied over the primer within the manufacturer’s recommended time and  artificially aged

  8. A High-Linearity Low-Noise Amplifier with Variable Bandwidth for Neural Recoding Systems

    Science.gov (United States)

    Yoshida, Takeshi; Sueishi, Katsuya; Iwata, Atsushi; Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi

    2011-04-01

    This paper describes a low-noise amplifier with multiple adjustable parameters for neural recording applications. An adjustable pseudo-resistor implemented by cascade metal-oxide-silicon field-effect transistors (MOSFETs) is proposed to achieve low-signal distortion and wide variable bandwidth range. The amplifier has been implemented in 0.18 µm standard complementary metal-oxide-semiconductor (CMOS) process and occupies 0.09 mm2 on chip. The amplifier achieved a selectable voltage gain of 28 and 40 dB, variable bandwidth from 0.04 to 2.6 Hz, total harmonic distortion (THD) of 0.2% with 200 mV output swing, input referred noise of 2.5 µVrms over 0.1-100 Hz and 18.7 µW power consumption at a supply voltage of 1.8 V.

  9. An AC modulated near infrared gain calibration system for a “Violin-Mode” transimpedance amplifier, intended for advanced LIGO suspensions

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a “tall-thin” rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse “Violin-Mode” vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor’s DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor’s more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz–300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m"−"1 was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC

  10. An AC modulated near infrared gain calibration system for a “Violin-Mode” transimpedance amplifier, intended for advanced LIGO suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance) Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-07-15

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which a 40 kg test-mass/mirror is suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation, and a “tall-thin” rectangular silicon photodiode detector, which together were to bracket the fibre under test. The photodiode was positioned so as to be sensitive (primarily) to transverse “Violin-Mode” vibrations of such a fibre, via the oscillatory movement of the shadow cast by the fibre, as this moved across the face of the detector. In this prototype shadow sensing system the photodiode was interfaced to a purpose-built transimpedance amplifier, this having both AC and DC outputs. A quasi-static calibration was made of the sensor’s DC responsivity, i.e., incremental rate of change of output voltage versus fibre position, by slowly scanning a fused-silica fibre sample transversely through the illuminating beam. The work reported here concerns the determination of the sensor’s more important AC (Violin-Mode) responsivity. Recognition of the correspondence between direct AC modulation of the source, and actual Violin-Mode signals, and of the transformative role of the AC/DC gain ratio for the amplifier, at any modulation frequency, f, resulted in the construction of the AC/DC calibration source described here. A method for determining in practice the transimpedance AC/DC gain ratio of the photodiode and amplifier, using this source, is illustrated by a specific numerical example, and the gain ratio for the prototype sensing system is reported over the frequency range 1 Hz–300 kHz. In fact, a maximum DC responsivity of 1.26 kV.m{sup −1} was measured using the prototype photodiode sensor and amplifier discussed here. Therefore, the measured AC

  11. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly

  12. The Design of Operational Amplifier for Low Voltage and Low Current Sound Energy Harvesting System

    Science.gov (United States)

    Fang, Liew Hui; Rahim, Rosemizi Bin Abd; Isa, Muzamir; Idris Syed Hassan, Syed; Ismail, Baharuddin Bin

    2018-03-01

    The objective of this paper is to design a combination of an operational amplifier (op-amp) with a rectifier used in an alternate current (ac) to direct current (dc) power conversion. The op-amp was designed to specifically work at low voltage and low current for a sound energy harvesting system. The goal of the op-amp design with adjustable gain was to control output voltage based on the objectives of the experiment conducted. The op-amp was designed for minimum power dissipation performance, with the means of increasing the output current when receiving a large amount of load. The harvesting circuits which designed further improved the power output efficiency by shortening the fully charged time needed by a supercapacitor bank. It can fulfil the long-time power demands for low power device. Typically, a small amount of energy sources were converted to electricity and stored in the supercapacitor bank, which was built by 10 pieces of capacitors with 0.22 F each, arranged in parallel connection. The highest capacitance was chosen based on the characteristic that have the longest discharging time to support the applications of a supercapacitor bank. Testing results show that the op-amp can boost the low input ac voltage (∼3.89 V) to high output dc voltage (5.0 V) with output current of 30 mA and stored the electrical energy in a big supercapacitor bank having a total of 2.2 F, effectively. The measured results agree well with the calculated results.

  13. An amplified promoter system for targeted expression of calcium indicator proteins in the cerebellar cortex

    Directory of Open Access Journals (Sweden)

    Bernd eKuhn

    2012-07-01

    Full Text Available Recording of identified neuronal network activity using genetically encoded calcium indicators (GECIs requires labeling that is cell type-specific and bright enough for the detection of functional signals. However, specificity and strong expression are often not achievable using the same promoter. Here we present a combinatorial approach for targeted expression and single-cell-level quantification in which a weak promoter is used to drive trans-amplification under a strong general promoter. We demonstrated this approach using recombinant adeno-associated viruses (rAAVs to deliver the sequence of the GECI D3cpv in the mouse cerebellar cortex. Direct expression under the human synapsin promoter (hSYN led to high levels of expression (50-100 µM in five interneuron types of the cerebellar cortex but not in Purkinje cells (PCs (≤10 μM, yielding sufficient contrast to allow functional signals to be recorded from somata and processes in awake animals using two-photon microscopy. When the hSYN promoter was used to drive expression of the tetracycline transactivator (tTA, a second rAAV containing the bidirectional TET promoter (Ptetbi could drive strong D3cpv expression in PCs (10-300 µM, enough to allow reliable complex spike detection in the dendritic arbor. An amplified approach should be of use in monitoring neural processing in selected cell types and boosting expression of optogenetic probes. Additionally, we overcome cell toxicity associated with rAAV injection and/or local GECI overexpression by combining the virus injection with systemic pre-injection of hyperosmotic D-mannitol, and by this double the time window for functional imaging.

  14. System for increasing laser pulse rate

    International Nuclear Information System (INIS)

    1980-01-01

    A technique of static elements is disclosed for combining a plurality of laser beams having time sequenced, pulsed radiation to achieve an augmented pulse rate. The technique may also be applied in a system for combining both time sequenced pulses and frequency distinct pulses for use in a system for isotope enrichment. (author)

  15. Correlation control theory of chaotic laser systems

    International Nuclear Information System (INIS)

    Li Fuli.

    1986-04-01

    A novel control theory of chaotic systems is studied. The correlation functions are calculated and used as feedback signals of the chaotic lasers. Computer experiments have shown that in this way the chaotic systems can be controlled to have time-independent output when the external control parameters are in chaotic domain. (author)

  16. Image digitizer system for bubble chamber laser

    International Nuclear Information System (INIS)

    Haggerty, H.

    1986-01-01

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

  17. Control system for JAERI Free Electron Laser

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1992-01-01

    A control system comprising of the personal computers network and the CAMAC stations for the JAERI Free Electron Laser is designed and is in the development stage. It controls the equipment and analyzes the electron and optical beam experiments. The concept and the prototype of the control system are described. (author)

  18. Fiber laser-microscope system for femtosecond photodisruption of biological samples.

    Science.gov (United States)

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F Ömer; Eldeniz, Y Burak; Tazebay, Uygar H

    2012-03-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.

  19. Frequency dependent loss analysis and minimization of system losses in switchmode audio power amplifiers

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2014-01-01

    In this paper, frequency dependent losses in switch-mode audio power amplifiers are analyzed and a loss model is improved by taking the voltage dependence of the parasitic capacitance of MOSFETs into account. The estimated power losses are compared to the measurement and great accuracy is achieved...

  20. Amplified Policymaking

    Science.gov (United States)

    Prince, Katherine; Woempner, Carolyn

    2010-01-01

    This brief examines the policy implications of two drivers of change presented in the "2020 Forecast: Creating the Future of Learning"-- Pattern Recognition and Amplified Organization. These drivers point toward a series of cultural shifts and illuminate how we are developing new ways of organizing, constructing, and managing knowledge.…

  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. Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s-1 directly modulated lasers and 40 Gb s-1 signal-regenerative amplifiers

    International Nuclear Information System (INIS)

    Sugawara, M; Hatori, N; Ishida, M; Ebe, H; Arakawa, Y; Akiyama, T; Otsubo, K; Yamamoto, T; Nakata, Y

    2005-01-01

    This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots in the active region for optical telecommunication. Based on our design in terms of the maximum bandwidth for high-speed modulation and p-type doping in quantum dots for high temperature stability, we realized temperature-insensitive 10 Gb s -1 laser diodes on a GaAs substrate at 1.3 μm. The output waveform at 10 Gb s -1 maintained a clear eye opening, average output power and extinction ratio without current adjustments from 20 deg. C to 70 deg. C. We developed ultrawide-band high-power amplifiers in the 1.5 μm wavelength region on an InP substrate. The amplifier showed ultrafast gain response under gain saturation, and enabled signal regeneration at 40 Gb s -1 by suppressing the '1'-level noise due to the beating between the signal and amplified spontaneous emission. We present our amplifier module with polarization diversity to enable a stable polarization-insensitive performance, and also, discuss prospects for polarization-insensitive quantum dots by the close stacking technique

  3. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    International Nuclear Information System (INIS)

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-01

    The problems involved in designing autonomous mobile laser systems based on high-power cw chemical DF lasers, whose mass and size parameters would make it possible to install them on various vehicles, are discussed. The need for mobility of such lasers necessitates special attention to be paid to the quest for ways and means of reducing the mass and size of the main laser systems. The optimisation of the parameters of such lasers is studied for various methods of scaling their systems. A complex approach to analysis of the optical scheme of the laser system is developed. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  4. Semiconductor-based narrow-line and high-brilliance 193-nm laser system for industrial applications

    Science.gov (United States)

    Opalevs, D.; Scholz, M.; Stuhler, J.; Gilfert, C.; Liu, L. J.; Wang, X. Y.; Vetter, A.; Kirner, R.; Scharf, T.; Noell, W.; Rockstuhl, C.; Li, R. K.; Chen, C. T.; Voelkel, R.; Leisching, P.

    2018-02-01

    We present a novel industrial-grade prototype version of a continuous-wave 193 nm laser system entirely based on solid state pump laser technology. Deep-ultraviolet emission is realized by frequency-quadrupling an amplified diode laser and up to 20 mW of optical power were generated using the nonlinear crystal KBBF. We demonstrate the lifetime of the laser system for different output power levels and environmental conditions. The high stability of our setup was proven in > 500 h measurements on a single spot, a crystal shifter multiplies the lifetime to match industrial requirements. This laser improves the relative intensity noise, brilliance, wall-plug efficiency and maintenance cost significantly. We discuss first lithographic experiments making use of this improvement in photon efficiency.

  5. Vacuum mechatronic laser alignment system on the Nova laser

    International Nuclear Information System (INIS)

    Holliday, M.; Wong, K.; Shelton, R.

    1991-11-01

    The experiments conducted on NOVA are done to investigate inertially confined laser fusion reactions. To this end, the ten beams of the laser are aligned to within 30mm. The target chamber employs a vacuum mechatronic based reticle/target positioning system to accomplish this. It is a five degree-of-freedom chamber resident system, known as the Alignment Aids Positioner or AAP. The AAP aids in beam and diagnostic alignment by accurately positioning a reticle at target chamber center to with 7mm. The AAP system increases target positioning and alignment flexibility and accuracy through the use of a computer controlled multi degree-of-freedom stage assembly. This device uses microstepping DC stepper motors with encoders to achieve closed loop control in a 10 -6 torr vacuum. The AAP has two positioning regimes to move the alignment reticle and do beam alignment. One is course positioning in the Y-Z plane that moves a high resolution stage assembly to target chamber center. The other regime is high resolution movement in the X,Y,Z and q directions. 5 refs., 9 figs

  6. An overview of copper-laser development for isotope separation

    International Nuclear Information System (INIS)

    Warner, B.E.

    1987-01-01

    We have developed a copper-laser pumped dye-laser system that addresses all of the requirements for atomic vapor laser isotope separation. The requirement for high average power for the laser system has led to the development of copper-laser chains with injection-locked oscillators and multihundred-watt amplifiers. By continuously operating the Laser Demonstration Facility, we gain valuable data for further upgrade and optimization

  7. Development of high power KrF laser for fundamental research of ICF driver and laser plasma interaction

    International Nuclear Information System (INIS)

    Wang Naiyan; Shan Yusheng; Ma Weiyi; Yao Gang; Zhou Chuangzhi; Tang Xiuzhang; Tang Zhihong; Gao Junsi; Wang Ganchang.

    1994-01-01

    A high power KrF laser system is under development in China Institute of Atomic Energy. The system consists of a front end, two-stage KrF amplifiers and two-stage Raman amplifiers, providing 100J, 1ns KrF laser with maximum average power density about 10 14 W/cm 2 on target for laser plasma interaction research. Some important technologies, such as front-end system, Angular Multiplexer, and injection locked oscillator are discussed. (author)

  8. Atomic iodine laser

    International Nuclear Information System (INIS)

    Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

    1978-05-01

    The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

  9. Inducing Strong Density Modulation with Small Energy Dispersion in Particle Beams and the Harmonic Amplifier Free Electron Laser

    CERN Document Server

    McNeil, Brian W J; Robb, Gordon

    2005-01-01

    We present a possible method of inducing a periodic density modulation in a particle beam with little increase in the energy dispersion of the particles. The flow of particles in phase space does not obey Liouville's Theorem. The method relies upon the Kuramoto-like model of collective synchronism found in free electron generators of radiation, such as Cyclotron Resonance Masers and the Free Electron Laser. For the case of an FEL interaction, electrons initially begin to bunch and emit radiation energy with a correlated energy dispersion which is periodic with the FEL ponderomotive potential. The relative phase between potential and particles is then changed by approximately 180 degrees. The particles continue to bunch, however, there is now a correlated re-absorption of energy from the field. We show that, by repeating this relative phase change many times, a significant density modulation of the particles may be achieved with only relatively small energy dispersion. A similar method of repeated relative ele...

  10. A low cost amplifier and acquisition system for cortical-electroncephalography in non-human applications.

    Science.gov (United States)

    Viggiano, A; Coppola, G

    2014-04-01

    A simple circuit is described to make an AC-amplifier and an analog-to-digital converter in a single, compact solution, for use in basic research, but not on humans. The circuit sends data to and is powered from a common USB port of modern computers; using proper firmware and driver the communication with the device is an emulated RS232 serial port.

  11. Design and Development of Monolithic Microwave Integrated Amplifiers and Coupling Circuits for Telecommunication Systems Applications

    Directory of Open Access Journals (Sweden)

    R. Makri

    2002-01-01

    quadrature coupler and a Wilkinson one in order to reduce size. Finally, a two stages low noise amplifier was designed with the use of H40 GaAs process in order the differences between the relevant designs to be explored. The key specifications for this MMIC LNA include operation at 10 GHz with a total gain of 17 dB while the noise figure is less than 1.5 dB.

  12. Retrofit of a high power Nd:glass laser system with liquid crystal polarizers

    International Nuclear Information System (INIS)

    Jacobs, S.D.; Cerqua, K.A.; Kessler, T.J.; Seka, W.; Bahr, R.

    1985-03-01

    The glass development laser (GDL), has been operating at the Laboratory for Laser Energetics since 1978. This Nd:phosphate glass system produces high peak power optical radiation at lambda = 1054 nm or lambda = 351 nm for use in studying the interaction physics of intense laser beams with matter. The amplifier staging incorporates the propagation of linearly and circularly polarized light in rod amplifiers which vary in diameter from 16 mm to 90 mm. Numerous quartz or mica quarter waveplates and Brewster angle dielectric thin film polarizers are required to limit accumulated phase retardation between amplification stages and to accommodate interstage Pockels' cell isolation switches. We have recently replaced most of the waveplate-dielectric polarizer combinations in GDL with liquid crystal polarizers. Comprised of 11 μm thick cholesteric fluids sandwiched between optical quality glass plates, liquid crystal polarizers provide excellent polarization properties, low insertion loss, angular insensitivity, and laser damage resistance at lambda = 1054 nm. The design, fabrication, and performance of left-handed and right-handed circular polarizers will be discussed

  13. Laser fusion system design study. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    The following studies were completed: (1) The synthesis of a pointing/control system compatible with existing and advanced laser opto-mechanical configurations. (2) Attainment of the required pointing angle, longitudinal focus, and differential pathlength accuracies. (3) Maximum modularization of the sensor and gimbal assemblies to provide the required accuracies at minimum cost. Detailed information is given on each. (MOW)

  14. Electronic Subsystems For Laser Communication System

    Science.gov (United States)

    Long, Catherine; Maruschak, John; Patschke, Robert; Powers, Michael

    1992-01-01

    Electronic subsystems of free-space laser communication system carry digital signals at 650 Mb/s over long distances. Applicable to general optical communications involving transfer of great quantities of data, and transmission and reception of video images of high definition.

  15. MBE System for Antimonide Based Semiconductor Lasers

    National Research Council Canada - National Science Library

    Lester, Luke

    1999-01-01

    .... SLR-770 inductively coupled plasma (ICP) processing system. The SLR-770 has been invaluable in the study of plasma etching of AlGaAsSb and GaSb-materials that form the backbone of antimonide-based semiconductor lasers...

  16. High-power noise-like pulse generation using a 1.56-µm all-fiber laser system.

    Science.gov (United States)

    Lin, Shih-Shian; Hwang, Sheng-Kwang; Liu, Jia-Ming

    2015-07-13

    We demonstrated an all-fiber, high-power noise-like pulse laser system at the 1.56-µm wavelength. A low-power noise-like pulse train generated by a ring oscillator was amplified using a two-stage amplifier, where the performance of the second-stage amplifier determined the final output power level. The optical intensity in the second-stage amplifier was managed well to avoid not only the excessive spectral broadening induced by nonlinearities but also any damage to the device. On the other hand, the power conversion efficiency of the amplifier was optimized through proper control of its pump wavelength. The pump wavelength determines the pump absorption and therefore the power conversion efficiency of the gain fiber. Through this approach, the average power of the noise-like pulse train was amplified considerably to an output of 13.1 W, resulting in a power conversion efficiency of 36.1% and a pulse energy of 0.85 µJ. To the best of our knowledge, these amplified pulses have the highest average power and pulse energy for noise-like pulses in the 1.56-µm wavelength region. As a result, the net gain in the cascaded amplifier reached 30 dB. With peak and pedestal widths of 168 fs and 61.3 ps, respectively, for the amplified pulses, the pedestal-to-peak intensity ratio of the autocorrelation trace remains at the value of 0.5 required for truly noise-like pulses.

  17. Infrared laser scattering system for the plasma diagnostics

    International Nuclear Information System (INIS)

    Hiraki, Naoji; Kawasaki, Shoji; Muraoka, Katsunori

    1975-01-01

    As the results of the parametric studies of the double discharge TEA CO 2 laser, the required properties on the laser system for the scattering diagnostics of plasmas are shown to be realized with our CO 2 laser. The direction of the future improvements of the laser performance is also discussed. (auth.)

  18. 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 lasers is verified by a 10 Gbit/s transmission experiment. Five DFB fibre lasers are cascaded and pumped by a single...... semiconductor laser, thereby forming a multiwavelength source for WDM systems...

  19. Design of an 1800nm Raman amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    We present the experimental results for a Raman amplifier that operates at 1810 nm and is pumped by a Raman fiber laser at 1680 nm. Both the pump laser and the Raman amplifier is polarization maintaining. A challenge when scaling Raman amplifiers to longer wavelengths is the increase...... in transmission loss, but also the reduction in the Raman gain coefficient as the amplifier wavelength is increased. Both polarization components of the Raman gain is characterized, initially for linearly co-polarized signal and pump, subsequently linearly polarized orthogonal signal and pump. The noise...

  20. Control interlock and monitoring system for 80 KW IOT based RF power amplifier system at 505.812 MHz for Indus-2

    International Nuclear Information System (INIS)

    Kumar, Gautam; Deo, R.K.; Jain, M.K.; Bagre, Sunil; Hannurkar, P.R.

    2013-01-01

    For 80 kW inductive output tube (IOT) based RF power amplifier system at 505.812 MHz for Indus-2, a control, interlock and monitoring system is realized. This is to facilitate proper start-up and shutdown of the amplifier system, monitor various parameters to detect any malfunction during its operation and to bring the system in a safe stage, thereby assuring reliable operation of the amplifier system. This high power amplifier system incorporates interlocks such as cooling interlocks, various voltage and current interlocks and time critical RF interlocks. Processing of operation sequence, cooling interlocks and various voltage and current interlocks have been realized by using Siemens make S7-CPU-315-2DP (CPU) based programmable logic controller (PLC) system. While time critical or fast interlocks have been realized by using Siemens make FPGA based Boolean Co-processor FM-352-5 which operates in standalone mode. Siemens make operating panel OP277 6'' is being used as a human machine interface (HMI) device for command, data, alarm generation and process parameter monitoring. (author)

  1. Characterization of a FBG sensor interrogation system based on a mode-locked laser scheme.

    Science.gov (United States)

    Madrigal, Javier; Fraile-Peláez, Francisco Javier; Zheng, Di; Barrera, David; Sales, Salvador

    2017-10-02

    This paper is focused on the characterization of a fiber Bragg grating (FBG) sensor interrogation system based on a fiber ring laser with a semiconductor optical amplifier as the gain medium, and an in-loop electro-optical modulator. This system operates as a switchable active (pulsed) mode-locked laser. The operation principle of the system is explained theoretically and validated experimentally. The ability of the system to interrogate an array of different FBGs in wavelength and spatial domain is demonstrated. Simultaneously, the influence of several important parameters on the performance of the interrogation technique has been investigated. Specifically, the effects of the bandwidth and the reflectivity of the FBGs, the SOA gain, and the depth of the intensity modulation have been addressed.

  2. NIF pointing and centering systems and target alignment using a 351 nm laser source

    International Nuclear Information System (INIS)

    Boege, S.J.; Bliss, E.S.; Chocol, C.J.; Holdener, F.R.; Miller, J.L.; Toeppen, J.S.; Vann, C.S.; Zacharias, R.A.

    1996-10-01

    The operational requirements of the National Ignition Facility (NIF) place tight constraints upon its alignment system. In general, the alignment system must establish and maintain the correct relationships between beam position, beam angle, laser component clear apertures, and the target. At the target, this includes adjustment of beam focus to obtain the correct spot size. This must be accomplished for all beamlines in a time consistent with planned shot rates and yet, in the front end and main laser, beam control functions cannot be initiated until the amplifiers have sufficiently cooled so as to minimize dynamic thermal distortions during and after alignment and wavefront optimization. The scope of the task dictates an automated system that implements parallel processes. We describe reticle choices and other alignment references, insertion of alignment beams, principles of operation of the Chamber Center Reference System 2048 and Target Alignment Sensor, and the anticipated alignment sequence that will occur between shots

  3. Study on APD real time compensation methods of laser Detection system

    International Nuclear Information System (INIS)

    Feng Ying; Zhang He; Zhang Xiangjin; Liu Kun

    2011-01-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained by analyzing

  4. Study on APD real time compensation methods of laser Detection system

    Energy Technology Data Exchange (ETDEWEB)

    Feng Ying; Zhang He; Zhang Xiangjin; Liu Kun, E-mail: fy_caimi@163.com [ZNDY of Ministerial Key Laboratory, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2011-02-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained

  5. Study on APD real time compensation methods of laser Detection system

    Science.gov (United States)

    Ying, Feng; He, Zhang; Xiangjin, Zhang; Kun, Liu

    2011-02-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained by analyzing

  6. Design development and testing of high voltage power supply with crowbar protection for IOT based RF amplifier system in VECC

    Science.gov (United States)

    Thakur, S. K.; Kumar, Y.

    2018-05-01

    This paper described the detailed design, development and testing of high voltage power supply (‑30 kV, 3.2 A) and different power supplies for biasing electrodes of Inductive Output Tube (IOT) based high power Radio Frequency (RF) amplifier. This IOT based RF amplifier is further used for pursuing research and development activity in superconducting RF cavity project at Variable Energy Cyclotron Centre (VECC) Kolkata. The state-of-the-art technology of IOT-based high power RF amplifier is designed, developed, and tested at VECC which is the first of its kind in India. A high voltage power supply rated at negative polarity of 30 kV dc/3.2 A is required for biasing cathode of IOT with crowbar protection circuit. This power supply along with crowbar protection system is designed, developed and tested at VECC for testing the complete setup. The technical difficulties and challenges occured during the design of cathode power supply, its crowbar protection techniques along with other supported power supplies i.e. grid and ion pump power supplies are discussed in this paper.

  7. IOT based RF power systems as an alternative to klystron amplifier in Indus-2 at the rate 505.812 MHz

    International Nuclear Information System (INIS)

    Deo, R.K.; Jain, M.K.; Kumar, Gautam; Lad, Mahendra; Badapanda, M.K.; Bagre, Sunil; Upadhyay, Rinki; Tripathi, Akhilesh; Rao, J.N.; Pandiyar, Mohan; Hannurkar, P.R.

    2013-01-01

    Due to non-availability of replacement Klystron tube in Indus-2, an IOT based high power RF amplifier system is realized. It is based on E2V make 80 kW IOTD2130 tube with its circuit assembly IMD2000ST. This amplifier system is easily available commercially due to its application in DTV broadcast. It has inherent advantages over klystron amplifier viz. high efficiency (η), less phase and amplitude sensitivity to HV ripple, higher linearity, compactness and less cooling requirement. This high power IOT amplifier is tested with its required control system, cooling system, electron gun auxiliary supplies, beam supply and focusing supply. The nominal beam voltage for this IOT is -36 kV however amplifier was tested successfully with indigenously developed -32 kV, crowbar less power supply. The optimum load impedance for IOT beam was calculated for this bias voltage ( 32kV). For the required load impedance, coupling coefficient (β) of output coupler to the O/P cavity was estimated and accordingly loop angle was adjusted. The amplifier has been tested up to 50 kW with amplifier efficiency 60% and gain 23 dB at - 32 kV beam voltage. (author)

  8. Recent laser experiments on the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Turner, T.P.; Jones, J.E.; Czuchlewski, S.J.; Watt, R.G.; Thomas, S.J.; Kang, M.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    The Aurora KrF/ICF Laser Facility at Los Alamos is operational at the kilojoule-level for both laser and target experiments. We report on recent laser experiments on the system and resulting system improvements. 3 refs., 4 figs

  9. Measurements of the temporal and spatial phase variations of a 33 GHz pulsed free electron laser amplifier and application to high gradient RF acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Volfbeyn, P.; Bekefi, G. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-12-31

    We report the results of temporal and spatial measurements of phase of a pulsed free electron laser amplifier (FEL) operating in combined wiggler and axial guide magnetic fields. The 33 GHz FEL is driven by a mildly relativistic electron beam (750 kV, 90-300 A, 30 ns) and generates 61 MW of radiation with a high power magnetron as the input source. The phase is measured by an interferometric technique from which frequency shifting is determined. The results are simulated with a computer code. Experimental studies on a CERN-CLIC 32.98 GHz 26-cell high gradient accelerating section (HGA) were carried out for input powers from 0.1 MW to 35 MW. The FEL served as the r.f. power source for the HGA. The maximum power in the transmitted pulse was measured to be 15 MW for an input pulse of 35 MW. The theoretically calculated shunt impedance of 116 M{Omega}/m predicts a field gradient of 65 MeV/m inside the HGA. For power levels >3MW the pulse transmitted through the HGA was observed to be shorter than the input pulse and pulse shortening became more serious with increasing power input. At the highest power levels the output pulse length (about 5 nsec) was about one quarter of the input pulse length. Various tests suggest that these undesirable effects occur in the input coupler to the HGA. Light and X-ray production inside the HGA have been observed.

  10. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD min ) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ

  11. 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... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device...

  12. Properties of a novel radiophotoluminescent readout system using a cw modulated UV laser diode and phase-sensitive technique

    International Nuclear Information System (INIS)

    Zhao, C.; Kurobori, T.; Miyamoto, Y.; Yamamoto, T.

    2011-01-01

    We have proposed and constructed a novel readout system for measuring a dose-dependent radiophotoluminescence (RPL) signal of a silver-activated phosphate glass dosimeter. The present reader consists of a modulated continuous-wave (cw) ultraviolet (UV) laser diode at 375 nm as an excitation and a phase-sensitive technique using a lock-in amplifier. Preliminary results using a home-made reader are compared with those of the conventional technique based on a combination of a pulsed UV N 2 laser excitation at 337 nm and a photon counting system.

  13. Commercialization plan laser-based decoating systems

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. A megajoule class krypton fluoride amplifier for single shot, high gain ICF application

    International Nuclear Information System (INIS)

    Rose, E.; Hanson, D.; Krohn, B.; McLeod, J.; Kang, M.

    1988-01-01

    A design study is underway to define the optimal architecture for a KrF laser system which will deliver 10 MJ of 248-nm light to an ICF target. We present one approach which incorporates final power amplifiers in the megajoule class, achieving 10 MJ with four final amplifiers. Each double-pass laser amplifier employs two-sided electron-beam pumping of the laser gas medium. Details of the design are based on a Monte-Carlo electron-beam deposition code, a one-dimensional, time-dependent kinetics code, and pulsed power circuit modeling. Linear dimensions of the amplifier's extracted gain volume are 6.25 m in height and length and 5.12 m in width. Each amplifier handles 160 angularly multiplexed laser channels. The one-amagat, krypton-rich laser medium is e-beam pumped at 60-kW cm/sup /minus/3/ (4-MA at3.3-MV) over the 2-microsecond duration of the laser beam pulse train. 5 refs., 4 figs

  16. Method and system for communicating with a laser power driver

    Science.gov (United States)

    Telford, Steven

    2017-07-18

    A system for controlling a plurality of laser diodes includes an optical transmitter coupled to the laser diode driver for each laser diode. An optical signal including bi-phase encoded data is provided to each laser diode driver. The optical signal includes current level and pulse duration information at which each of the diodes is to be driven. Upon receiving a trigger signal, the laser diode drivers operate the laser diodes using the current level and pulse duration information to output a laser beam.

  17. The laser thermonuclear fusion

    International Nuclear Information System (INIS)

    Coutant, J.; Dautray, R.; Decroisette, M.; Watteau, J.P.

    1987-01-01

    Principle of the thermonuclear fusion by inertial confinement: required characteristics of the deuterium-tritium plasma and of the high power lasers to be used Development of high power lasers: active media used; amplifiers; frequency conversion; beam quality; pulse conditioning; existing large systems. The laser-matter interaction: collision and collective interaction of the laser radiation with matter; transport of the absorbed energy; heating and compression of deuterium-tritium; diagnoses and their comparison with the numerical simulation of the experiment; performances. Conclusions: difficulties to overcome; megajoule lasers; other energy source: particles beams [fr

  18. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  19. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    2005-01-01

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  20. High efficiency pump combiner fabricated by CO2 laser splicing system

    Science.gov (United States)

    Zhu, Gongwen

    2018-02-01

    High power combiners are of great interest for high power fiber lasers and fiber amplifiers. With the advent of CO2 laser splicing system, power combiners are made possible with low manufacturing cost, low loss, high reliability and high performance. Traditionally fiber optical components are fabricated with flame torch, electrode arc discharge or filament heater. However, these methods can easily leave contamination on the fiber, resulting inconsistent performance or even catching fire in high power operations. The electrodes or filaments also degrade rapidly during the combiner manufacturing process. The rapid degradation will lead to extensive maintenance, making it unpractical or uneconomic for volume production. By contrast, CO2 laser is the cleanest heating source which provides reliable and repeatable process for fabricating fiber optic components including high power combiners. In this paper we present an all fiber end pumped 7x1 pump combiner fabricated by CO2 laser splicing system. The input pump fibers are 105/125 (core/clad diameters in μm) fibers with a core NA of 0.22. The output fiber is a 300/320 fiber with a core NA of 0.22. The average efficiency is 99.4% with all 7 ports more than 99%. The process is contamination-free and highly repeatable. To our best knowledge, this is the first report in the literature on power combiners fabricated by CO2 laser splicing system. It also has the highest reported efficiency of its kind.

  1. Laser fusion systems for industrial process heat. Third semiannual report

    International Nuclear Information System (INIS)

    Bates, F.J.; Denning, R.S.; Dykhuizen, R.C.; Goldthwaite, W.H.; Kok, K.D.; Skelton, J.C.

    1979-01-01

    This report concentrates not only on the design of the laser fusion system but also on the cost of this system and the costs of alternative sources of energy that are expected to be in competition with the laser fusion system. The absolute values of the cost of the laser fusion system are limited by the estimates of the cost of the components and subsystems making up the laser fusion energy station. The method used in calculating costs of the laser fusion and alternative systems are laid out in detail

  2. Laser fusion hybrid reactor systems study

    International Nuclear Information System (INIS)

    1976-07-01

    The work was performed in three phases. The first phase included a review of the many possible laser-reactor-blanket combinations and resulted in the selection of a ''demonstration size'' 500 MWe plant for further study. A number of fast fission blankets using uranium metal, uranium-molybdenum alloy, and uranium carbide as fuel were investigated. The second phase included design of the reactor vessel and internals, heat transfer system, tritium processing system, and the balance of plant, excluding the laser building and equipment. A fuel management scheme was developed, safety considerations were reviewed, and capital and operating costs were estimated. Costs developed during the second phase were unexpectedly high, and a thorough review indicated considerable unit cost savings could be obtained by scaling the plant to a larger size. Accordingly, a third phase was added to the original scope, encompassing the redesign and scaling of the plant from 500 MWe to 1200 MWe

  3. Spatial beam shaping using a micro-structured optical fiber and all-fiber laser amplification system for large-scale laser facilities seeding

    International Nuclear Information System (INIS)

    Calvet, Pierre

    2014-01-01

    Spatial beam shaping is an important topic for the lasers applications. For various industrial areas (marking, drilling, laser-matter interaction, high-power laser seeding...) the optical beam has to be flattened. Currently, the state of the art of the beam shaping: 'free-space' solutions or highly multimode fibers, are not fully suitable. The first ones are very sensitive to any perturbations and the maintenance is challenging, the second ones cannot deliver a coherent beam. For this reason, we present in this manuscript a micro-structured optical single-mode fiber delivering a spatially flattened beam. This 'Top-Hat' fiber can shape any beam in a spatially coherent beam what is a progress with respect to the highly multimode fibers used in the state of the art. The optical fibers are easy to use and very robust, what is a strong benefit with respect to the 'free-space' solutions. Thanks to this fiber, we could realize an all-fiber multi-stage laser chain to amplify a 10 ns pulse to 100 μJ. Moreover the temporal, spectral and spatial properties were preserved. We adapted this 'Top-Hat' fiber to this multi-stage laser chain, we proved the capability and the interest of this fiber for the spatial beam shaping of the laser beams in highly performing and robust laser systems. (author) [fr

  4. Quasi-continuously pumped passively mode-locked 2.4% doped Nd:YAG oscillator-amplifier system in a bounce geometry

    Science.gov (United States)

    Jelínek, Michal; Kubecek, Vaclav; Cech, Miroslav; Hirsl, Petr

    2010-02-01

    We report on oscillator-amplifier system based on two highly doped 2.4 at. % crystalline Czochralski grown Nd:YAG crystals in a diode pumped bounce geometry configuration under quasi-continuous pumping. The oscillator was passively mode-locked by the semiconductor saturable absorber in transmission mode. The output pulse train consisted of 5 pulses with total energy of 270 μJ and pulse duration of 75 ps. The output train from the oscillator was amplified to the energy of 1 mJ by single pass amplifier.

  5. Combined Yb/Nd driver for optical parametric chirped pulse amplifiers.

    Science.gov (United States)

    Michailovas, Kirilas; Baltuska, Andrius; Pugzlys, Audrius; Smilgevicius, Valerijus; Michailovas, Andrejus; Zaukevicius, Audrius; Danilevicius, Rokas; Frankinas, Saulius; Rusteika, Nerijus

    2016-09-19

    We report on the developed front-end/pump system for optical parametric chirped pulse amplifiers. The system is based on a dual output fiber oscillator/power amplifier which seeds and assures all-optical synchronization of femtosecond Yb and picosecond Nd laser amplifiers operating at a central wavelength of 1030 nm and 1064 nm, respectively. At the central wavelength of 1030 nm, the fiber oscillator generates partially stretched 4 ps pulses with the spectrum supporting a scaling currently is prevented by limited dimensions of the diffraction gratings, which, because of the fast progress in MLD grating manufacturing technologies is only a temporary obstacle.

  6. System for combining laser beams of diverse frequencies

    International Nuclear Information System (INIS)

    1980-01-01

    A system is described for combining laser beams of different frequencies into a number of beams each comprising laser radiation having components of each of the different frequencies. The system can be used in laser isotope separation facilities. (U.K.)

  7. Laser surveillance systems for fuel storage pools

    International Nuclear Information System (INIS)

    Boeck, H.

    1985-06-01

    A Laser Surveillance System (LASSY) as a new safeguards device has been developed under the IAEA research contract No. 3458/RB at the Atominstitut Wien using earlier results by S. Fiarman. This system is designed to act as a sheet of light covering spent fuel assemblies in spent fuel storage pools. When movement of assemblies takes place, LASSY detects and locates the position of the movement in the pool and when interrogated, presents a list of pool positions and times of movement to the safeguards inspector. A complete prototype system was developed and built. Full scale tests showed the principal working capabilities of a LASSY underwater

  8. Laser control of natural disperse systems

    Science.gov (United States)

    Vlasova, Olga L.; Bezrukova, Alexandra G.

    2003-10-01

    Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

  9. Higher order mode optical fiber Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Friis, Søren Michael Mørk; Usuga Castaneda, Mario A.

    2016-01-01

    We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations.......We review higher order mode Raman amplifiers and discuss recent theoretical as well as experimental results including system demonstrations....

  10. 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....

  11. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann

    2012-01-01

    We experimentally demonstrate enhanced gain in the slow-light regime of quantum well photonic crystal amplifiers. A strong gain enhancement is observed with the increase of the group refractive index, due to light slow-down. The slow light enhancement is shown in a amplified spontaneous emission....... These results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

  12. Laser experimental system as teaching aid for demonstrating basic phenomena of laser feedback

    International Nuclear Information System (INIS)

    Xu, Ling; Zhao, Shijie; Zhang, Shulian

    2015-01-01

    An experimental laser teaching system is developed to demonstrate laser feedback phenomena, which bring great harm to optical communication and benefits to precision measurement. The system consists of an orthogonally polarized He-Ne laser, a feedback mirror which reflects the laser output light into the laser cavity, and an optical attenuator which changes the intensity of the feedback light. As the feedback mirror is driven by a piezoelectric ceramic, the attenuator is adjusted and the feedback mirror is tilted, the system can demonstrate many basic laser feedback phenomena, including weak, moderate and strong optical feedback, multiple feedback and polarization flipping. Demonstrations of these phenomena can give students a better understanding about the intensity and polarization of lasers. The system is well designed and assembled, simple to operate, and provides a valuable teaching aid at an undergraduate level. (paper)

  13. A hybrid CATV/16-QAM-OFDM visible laser light communication system

    International Nuclear Information System (INIS)

    Lin, Chun-Yu; Li, Chung-Yi; Lu, Hai-Han; Chen, Chia-Yi; Jhang, Tai-Wei; Ruan, Sheng-Siang; Wu, Kuan-Hung

    2014-01-01

    A visible laser light communication (VLLC) system employing a vertical cavity surface emitting laser and spatial light modulator with hybrid CATV/16-QAM-OFDM modulating signals over a 5 m free-space link is proposed and demonstrated. With the assistance of a push-pull scheme, low-noise amplifier, and equalizer, good performances of composite second-order and composite triple beat are obtained, accompanied by an acceptable carrier-to-noise ratio performance for a CATV signal, and a low bit error rate value and clear constellation map are achieved for a 16-QAM-OFDM signal. Such a hybrid CATV/16-QAM-OFDM VLLC system would be attractive for providing services including CATV, Internet and telecommunication services. (paper)

  14. Recent advances in excimer laser technology at Los Alamos

    International Nuclear Information System (INIS)

    Bigio, I.J.; Czuchlewski, S.; McCown, A.W.; Taylor, A.J.

    1991-01-01

    This paper reports that current research in excimer laser technology at Los Alamos progresses in two major areas: In the Bright Source program, the development of ultra-high brightness (sub-piosecond) laser systems, based on discharge -pumped excimer laser amplifiers, continues Recently the authors have completed rigorous measurements of the saturation parameter for ultra-short pulses. In the laser fusion program, implementation of the large KrF laser fusion amplifiers have been accompanied by numerous studies of the laser physics and kinetics of large e-beam pumped devices

  15. Synchronised laser chaos communication: statistical investigation of an experimental system

    OpenAIRE

    Lawrance, Anthony J.; Papamarkou, Theodore; Uchida, Atsushi

    2017-01-01

    The paper is concerned with analyzing data from an experimental antipodal laser-based chaos shift-keying communication system. Binary messages are embedded in a chaotically behaving laser wave which is transmitted through a fiber-optic cable and are decoded at the receiver using a second laser synchronized with the emitter laser. Instrumentation in the experimental system makes it particularly interesting to be able to empirically analyze both optical noise and synchronization error as well a...

  16. A High-Energy, 100 Hz, Picosecond Laser for OPCPA Pumping

    Directory of Open Access Journals (Sweden)

    Hongpeng Su

    2017-09-01

    Full Text Available A high-energy diode-pumped picosecond laser system centered at 1064 nm for optical parametric chirped pulse amplifier (OPCPA pumping was demonstrated. The laser system was based on a master oscillator power amplifier configuration, which contained an Nd:YVO4 mode-locked seed laser, an LD-pumped Nd:YAG regenerative amplifier, and two double-pass amplifiers. A reflecting volume Bragg grating with a 0.1 nm reflective bandwidth was used in the regenerative amplifier for spectrum narrowing and pulse broadening to suit the pulse duration of the optical parametric amplifier (OPA process. Laser pulses with an energy of 316.5 mJ and a pulse duration of 50 ps were obtained at a 100 Hz repetition rate. A top-hat beam distribution and a 0.53% energy stability (RMS were achieved in this system.

  17. Amplified spontaneous emission measurements on the Aurora large aperture module

    International Nuclear Information System (INIS)

    Oertel, J.A.; Czuchlewski, S.J.; Leland, W.T.; Turner, T.P.

    1990-01-01

    The large aperture module (LAM) of the Aurora KrF laser can be used to address a number of issues that relate to the scaling of KrF amplifiers to larger ICF systems. Perhaps foremost among these are the possible effects of amplified spontaneous emission (ASE) on laser performance. To assess this problem a 3-D computer code has been developed to model these ASE effects. The code uses an iterative procedure to arrive at a self-consistent steady state solution to the 3-D distribution of coherent and incoherent fluxes within the amplifier. Two-pass energy extraction, wall reflectivity, and nonuniform excitation are included in the model. The authors previously reported the effects of ASE on the small signal gains measured in the 1- x 1- x 2-m 3 LAM. The code also makes quantitative predictions of the ASE that should be generated in the amplifier. This paper indicates the radiance expected for a medium of uniform gain in terms of the (g - ν)L product and the parameter g/a. The quantity (g - ν)L is the product of the net gain and the path length along the direction of observation. The present experiments compare values of ASE measured at various locations around the LAM with the code predictions. The impact of ASE on amplifier output, is also discussed

  18. 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

    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. A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal". 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. 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.

  19. High-energy glass lasers

    International Nuclear Information System (INIS)

    Glaze, J.A.

    1975-01-01

    In order to investigate intense pulse propagation phenomena, as well as problems in laser and system design, a prototype single chain laser called CYCLOPS was constructed. This laser employs a 20-cm clear aperture disk amplifier in its final stage and produces a terawatt pulse whose brightness exceeds 10 18 watts/cm 2 -ster. The CYCLOPS system is summarized and aspects of nonlinear propagation phenomena that are currently being addressed are discussed. (MOW)

  20. Laser-start-up system for magnetic mirror fusion

    International Nuclear Information System (INIS)

    Frank, A.M.; Thomas, S.R.; Denhoy, B.S.; Chargin, A.K.

    1976-01-01

    A CO 2 laser system has been developed at LLL to provide hot start-up plasmas for magnetic mirror fusion experiments. A frozen ammonia pellet is irradiated with a laser power density in excess of 10 13 W/cm 2 in a 50-ns pulse. This system uses commercially available laser systems. Optical components were fabricated both by direct machining and standard techniques. The technologies used in this system are directly applicable to reactor scale systems