Science.gov

Sample records for absorbed pump power

  1. Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1984-01-01

    The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

  2. High-power 880-nm diode-directly-pumped passively mode-locked Nd:YVO₄ laser at 1342 nm with a semiconductor saturable absorber mirror.

    PubMed

    Li, Fang-Qin; Liu, Ke; Han, Lin; Zong, Nan; Bo, Yong; Zhang, Jing-Yuan; Peng, Qin-Jun; Cui, Da-Fu; Xu, Zu-Yan

    2011-04-15

    A high-power 880-nm diode-directly-pumped passively mode-locked 1342 nm Nd:YVO₄ laser was demonstrated with a semiconductor saturable absorber mirror (SESAM). The laser mode radii in the laser crystal and on the SESAM were optimized carefully using the ABCD matrix formalism. An average output power of 2.3 W was obtained with a repetition rate of 76 MHz and a pulse width of 29.2 ps under an absorbed pump power of 12.1 W, corresponding to an optical-optical efficiency of 19.0% and a slope efficiency of 23.9%, respectively. PMID:21499398

  3. Investigation of the laser pumping power impact on the operating regimes of a laser passively Q-switched by a saturated absorber

    NASA Astrophysics Data System (ADS)

    Benarab, Mustapha; Mokdad, Rabah; Djellout, Hocine; Benfdila, Arezki; Lamrous, Omar; Meyrueis, Patrick

    2011-09-01

    We have adapted the point model for the study of an all-fiber laser doped with Nd3+ and Q-switched by a saturable fiber absorber doped with Cr4+. Calculations of the output power of the 1084 nm laser are considered as a function of the pump power supplied by a 790 nm laser diode. The analysis of the simulation results reveals the existence of pulsed, sinusoidal, and dc operating regimes.

  4. High-peak-power flashlamp-pumped passively Q-switched Nd:YAG laser with AlGaInAs quantum wells as a saturable absorbers

    NASA Astrophysics Data System (ADS)

    Liang, H. C.; Huang, J. Y.; Huang, S. C.; Su, K. W.; Chen, Y. F.; Huang, K. F.

    2008-02-01

    We demonstrate an AlGaInAs saturable absorber with a periodic quantum wells (QWs)/barrier structure that can be used to achieve an efficient high-peak-power and high-pulse-energy passively flashlamp-pumped Q-switched Nd:YAG laser at 1.06 um. The barrier layers are designed to locate the QW groups in the region of the nodes of the lasing standing wave to avoid damage. With an incident pump voltage of 14.5 J, a single pulse was generated with a pulse energy of 14 mJ and a Q-switched pulse width of 13 ns. The maximum peak power was greater than 1.08 MW.

  5. Hydroxide absorption heat pumps with spray absorber

    SciTech Connect

    Summerer, F.; Alefeld, G.; Zeigler, F.; Riesch, P.

    1996-11-01

    The absorber is one of the most expensive components of an absorption heat pump or chiller, respectively. In order to reduce the cost of a heat exchanger, much effort is invested into searching for additives for heat transfer enhancement. Another way to reduce heat exchanger cost, especially for machines with low capacities, is to use an adiabatic spray absorber. The basic principles of the spray absorber is to perform heat and mass transfer separated from each other in two different components. In this way the heat can be rejected effectively in a liquid-liquid heat exchanger, whereas the mass transfer occurs subsequently in a simple vessel. The spray technique can not only save heat exchanger cost in conventional absorption systems working with water and lithium bromide, it also allows the use of quite different working fluids such as hydroxides, which have lower heat transfer coefficients in falling films. Moreover, the separated heat transfer can easily be performed in a liquid-to-air heat exchanger. Hence it is obvious to use hydroxides that allow for a high temperature lift for building an air-cooled chiller with spray absorber. In this presentation theoretical and experimental investigations of the spray absorber as well as the setup will be described. Finally, possible applications will be outlined.

  6. Absorber for solar power.

    PubMed

    Powell, W R

    1974-10-01

    A simple, economical absorber utilizing a new principle of operation to achieve very low reradiation losses while generating temperatures limited by material properties of quartz is described. Its performance is analyzed and indicates approximately 90% thermal efficiency and 73% conversion efficiency for an earth based unit with moderately concentrated (~tenfold) sunlight incident. It is consequently compatible with the most economic of concentrator mirrors (stamped) or mirrors deployable in space. Space applications are particularly attractive, as temperatures significantly below 300 K are possible and permit even higher conversion efficiency. PMID:20134700

  7. Rubber shock absorber for deep-well rod operated pumps

    SciTech Connect

    Bagirov, M.M.

    1984-05-01

    Tests of hydropneumatic shock absorbers of deep-well pumps in oil fields showed that they improve the efficiency of the installations by their design is very complicated. Mechanically acting absorbers of dynamic forces are simpler in design. Rubber shock absorbers differ advantageously from spring absorbers in that considerable oscillation-damping forces of any amplitude act in them. The design of a shock absorber is described which is situated under the balance arm of a pumping jack. A prototype of the shock absorber, in which the elastic elements were cylinders made of rubber was tested in a test borehole. Dynamographic recordings made in this borehole in operation with and without shock absorber show that the shock absorber reduces the maximum load on the rods and the double amplitude of load change. Calculations show that when the described shock absorber is used the reduced load is 11-18% smaller. This may considerably reduce the number of breakages of deepwell pump rods.

  8. Electromagnetic power absorber

    NASA Technical Reports Server (NTRS)

    Iwasaki, R.

    1977-01-01

    Device has reflection coefficient of order of few tenths of percent and is designed to maintain isothermal temperature distribution in high-power microwave and laser applications. Rigid tile functions over broad temperature range and serves as blackbody radiometric standard. Tile modules allow assembly of compact and economical custom-design configurations. Epoxy surface of tiles is insulated with styrofoam against environmental changes and is not subject to convective heat loss. Technique also prevents moisture accumulation and serves as infrared radiation shield.

  9. Solar-powered pump

    NASA Technical Reports Server (NTRS)

    Kirsten, C. C. (Inventor)

    1976-01-01

    A solar powered pump particularly suited for intermittently delivering a stream of water is reported. The pump is characterized by a housing adapted to be seated in a source of water having a water discharge port disposed above the water line of the source, a sump including a valved inlet port through which water is introduced to the sump, disposed beneath the water line, a displacer supported for vertical reciprocation in said housing, an air passageway extended between the vertically spaced faces of the displacer, and a tipple disposed adjacent to the water discharge port adapted to be filled in response to a discharge of water from the housing. Air above a displacer is expanded in response to solar energy impinging on the housing and transferred into pressurizing relation with the sump for forcing water from the sump.

  10. Pump dependence of the dynamics of quantum dot based waveguide absorbers

    NASA Astrophysics Data System (ADS)

    Viktorov, Evgeny A.; Erneux, Thomas; Piwonski, Tomasz; Pulka, Jaroslaw; Huyet, Guillaume; Houlihan, John

    2012-06-01

    The nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is investigated experimentally and analytically as a function of the initial ground state occupation probability of the dot. The latter is controlled experimentally by the pump pulse power. The slow stage of the recovery is exponential and its basic timescale is independent of pump power. The fast stage of the recovery is a logistic function which we analyze in detail. The relative strength of slow to fast components is highlighted and the importance of higher order absorption processes at the highest pump level is demonstrated.

  11. Saturable absorber theory with a modulated pump beam

    NASA Astrophysics Data System (ADS)

    Blaya, S.; Acebal, P.; Carretero, L.

    2016-08-01

    Recently, it has been shown that the time delay of a signal in a saturable absorber can be equally analysed by a temporal variation of the absorption or the phase (group velocity reduction). In this work, we perform the study of time advancement and delay of transmitted pulses in bacteriorhodopsin films by using a time modulated pump beam at the same frequency of modulation as the reference beam. Thus, based on a saturable absorber theory, analytical expressions of the time delay/advancement and the transmitted pulse have been obtained. As a result, it is theoretically and experimentally demonstrated, that by means of the phase difference between the pump and reference beams a temporal advancement or delay of the sinusoidal transmitted pulses can be obtained.

  12. Thermal-powered reciprocating pump

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1972-01-01

    Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.

  13. Overview of Pump Room, showing pumps at right and power ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of Pump Room, showing pumps at right and power distribution cabinets for valve motors along north wall at left. View to east - Wellton-Mohawk Irrigation System, Pumping Plant No. 1, Bounded by Gila River & Union Pacific Railroad, Wellton, Yuma County, AZ

  14. Mode locking of diode- and flashlamp-pumped Nd:YAG lasers using semiconductor saturable absorbers

    NASA Astrophysics Data System (ADS)

    Dombrovsky, Andrej; Kubecek, Vaclav; Zvonicek, K.; Diels, Jean-Claude M.; Stintz, Andreas

    2003-07-01

    Operation of laser diode and flash lamp pumped Nd:YAG lasers mode locked with two different types of semiconductor saturable absorbers is reported. In the first type that is used mainly in diode pumped systems the absorber layers are integrated on highly reflective Bragg mirror. The second type is for use in transmission mode inside the resonator. Different design of semiconductor elements, pumping geometries and resonator configurations were investigated and characteristics of laser operation in mode-locked regime are presented.

  15. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    NASA Astrophysics Data System (ADS)

    Chou, T. S.; Foerster, C. L.; Halama, H.; Lanni, C.

    1988-09-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U10B beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented.

  16. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    SciTech Connect

    Chou, T.S.; Foerster, C.L.; Halama, H.; Lanni, C.

    1988-01-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U1OB beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented. 5 refs., 7 figs., 1 tab.

  17. Solar powered blackbody-pumped lasers

    NASA Astrophysics Data System (ADS)

    Christiansen, Walter H.; Sirota, J. M.

    1991-02-01

    A concept for a solar-powered laser is presented which utilizes an intermediate blackbody cavity to provide a uniform optical pumping environment for the lasant, typically CO or CO2 or possibly a solid state laser medium. High power cw blackbody- pumped lasers with efficiencies on the order of 20 percent or more are feasible. The physical basis of this idea is reviewed. Small scale experiments using a high temperature oven as the optical pump have been carried out with gas laser mixtures. Detailed calculations showing a potential efficiency of 35 percent for blackbody pumped Nd:YAG system are discussed.

  18. Nano-porous-water Absorbents for Solid-absorbebt Heat Pump System

    NASA Astrophysics Data System (ADS)

    Mizota, Tadato; Nakayama, Noriaki

    Zeolite-water heat-pump system has been developed in these 25 years. Recently, an instant beer-cooling system has appeared by using the zeolite heat pump system as a commercial product. It takes so long time for the development since the first proposal. The most serious problem through the development has been of the ability of absorbents. Themaximum heat exchange capacity to date exceeds 1MJ•kg-1 for Mg89-A, which is comparable to the energy storage capacity of modern alkaline-ion batteries in weight-bases. But it needs high temperature heat sources more than 200°C for the activation. Absorbents useful at lower temperatures are thus desirable for effective use of various kinds of lower temperature heat sources Various nano-porous materials as well as zeolites now under investigation as candidates of heat-pump absorbents, such as silica-gels, allophane, imogolite, hydrotalcite, etc.

  19. High power diode pumped alkali vapor lasers

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Krupke, B.

    2008-05-01

    Diode pumped alkali lasers have developed rapidly since their first demonstration. These lasers offer a path to convert highly efficient, but relatively low brightness, laser diodes into a single high power, high brightness beam. General Atomics has been engaged in the development of DPALs with scalable architectures. We have examined different species and pump characteristics. We show that high absorption can be achieved even when the pump source bandwidth is several times the absorption bandwidth. In addition, we present experimental results for both potassium and rubidium systems pumped with a 0.2 nm bandwidth alexandrite laser. These data show slope efficiencies of 67% and 72% respectively.

  20. Modeling of forward pump EDFA under pump power through MATLAB

    NASA Astrophysics Data System (ADS)

    Raghuwanshi, Sanjeev Kumar; Sharma, Reena

    2015-05-01

    Optical fiber loss is a limiting factor for high-speed optical network applications. However, the loss can be compensated by variety of optical amplifiers. Raman amplifier and EDFA amplifier are widely used in optical communication systems. There are certain advantages of EDFA over Raman amplifier like amplifying the signal at 1550 nm wavelength at which the fiber loss is minimum. Apart from that there is no pulse walk-off problem with an EDFA amplifier. With the advent of optical amplifiers like EDFA, it is feasible to achieve a high bit rate beyond terabits in optical network applications. In our study, a MATLAB simulink-based forward pumped EDFA (operating in C-band 1525-1565 nm) simulation platform has been devised to evaluate the following performance parameters like gain, noise figure, amplified spontaneous emission power variations of a forward pumped EDFA operating in C-band (1525-1565 nm) as functions of Er3+ fiber length, injected pump power, signal input power, and Er3+ doping density. The effect of an input pump power on gain and noise figure was illustrated graphically. It is possible to completely characterize and optimize the EDFA performance using our dynamic simulink test bed.

  1. Efficient passive Q-switching operation of a diode-pumped Nd:GdVO4 laser with a Cr4+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Liu, Junhai; Ozygus, Bernd; Yang, Suhui; Erhard, Jürgen; Seelig, Ute; Ding, Adalbert; Weber, Horst; Meng, Xianlin; Zhu, Li; Qin, Lianjie; Du, Chenlin; Xu, Xinguang; Shao, Zongshu

    2003-04-01

    A diode-pumped highly efficient Cr4+:YAG passively Q-switched Nd:GdVO4 laser formed by a plano-concave resonator has been demonstrated. At the highest attainable absorbed pump power of 11.4 W, 4.05 W of average output power, which was two thirds of the maximum corresponding cw output, was achieved with an optical conversion efficiency of 35.5%, and the slope efficiency was determined to be 46.8%, reaching 85% of the magnitude of its cw counterpart. The resulting shortest pulse duration, single-pulse energy, and peak power were found to be 13 ns, 90 μJ, and 7 kW, respectively, with a pulse repetition frequency (PRF) of 45 kHz. Two particularly modified resonator configurations were employed; the largest pulse energy and the highest peak power reached were, respectively, 154 μJ and 11.2 kW at 8.5 W of absorbed pump power. An analytical relation between the PRF and the absorbed pump power is given for a passively Q-switched laser, showing good consistency with experiment with a Nd:GdVO4 laser. The dependence of the operational parameters on the pump power and on the output coupling was also investigated experimentally. Issues involving the criterion for passive Q switching are discussed in some detail for Cr4+:YAG passively Q-switched neodymium-doped vanadate lasers.

  2. Fundamental research on oscillating water column wave power absorbers

    SciTech Connect

    Maeda, H.; Kato, W.; Kinoshita, T.; Masuda, K.

    1985-03-01

    An oscillating water column (OWC) wave power absorber is one of the most promising devices, as well as the Salter Duck and the Clam. This paper presents a simple prediction method, in which the equivalent floating body approximation is used, for absorbing wave power characteristics of an oscillating water column device. The effects of the compressibility of air and inertia of an air turbine and electric generator on absorbed wave power are obtained by using the equivalent electric circuit concept. Both the experimental and theoretical studies are carried out in this paper.

  3. The hydraulic design of pump turbine for Xianyou pumped storage power station

    NASA Astrophysics Data System (ADS)

    Zheng, J. S.; Liu, W. C.; Fu, Z. Y.; Shi, Q. H.

    2012-11-01

    This paper presents the hydraulic design of pump turbines for Xianyou pumped storage power station. The method of improving the hydraulic performance of pump turbine with CFD analysis is given. The results of model test indicate that the final hydraulic design of pump turbine for Xianyou pumped storage power station is of high efficiencies, good

  4. Solar-powered turbocompressor heat pump system

    DOEpatents

    Landerman, A.M.; Biancardi, F.R.; Melikian, G.; Meader, M.D.; Kepler, C.E.; Anderson, T.J.; Sitler, J.W.

    1982-08-12

    The turbocompressor comprises a power turbine and a compressor turbine having respective rotors and on a common shaft, rotatably supported by bearings. A first working fluid is supplied by a power loop and is expanded in the turbine. A second working fluid is compressed in the turbine and is circulated in a heat pump loop. A lubricant is mixed with the second working fluid but is excluded from the first working fluid. The bearings are cooled and lubricated by a system which circulates the second working fluid and the intermixed lubricant through the bearings. Such system includes a pump, a thermostatic expansion valve for expanding the working fluid into the space between the bearings, and a return conduit system for withdrawing the expanded working fluid after it passes through the bearings and for returning the working fluid to the evaporator. A shaft seal excludes the lubricant from the power turbine. The power loop includes a float operable by liquid working fluid in the condenser for controlling a recirculation valve so as to maintain a minimum liquid level in the condenser, while causing a feed pump to pump most of the working fluid into the vapor generator. The heat pump compressor loop includes a float in the condenser for operating and expansion valve to maintain a minimum liquid working fluid level in the condenser while causing most of the working fluid to be expanded into the evaporator.

  5. LD-pumped passively Q-switched Nd:GGG laser at 1062 nm with a GaAs saturable absorber

    NASA Astrophysics Data System (ADS)

    Zhang, H. N.; Li, P.; Wang, Q. P.; Chen, X. H.

    2011-11-01

    we have experimentally studied the passively Q-switched performance of a diode-pumped Nd:GGG laser at 1062 nm with a GaAs saturable absorber, in the experiment when the pumped power was 9.8 W, the maximum CW output power of 5.1 W was obtained. The optical conversion efficiency and the slop efficiency were 52 and 53%, respectively. The threshold was 0.9 W. In the passively Q-switched regime, we get the average output power of 0.93 W. The shortest pulse width and pulse repetition rate were 7 ns and 188 kHz, respectively.

  6. Comparison of solar powered water pumping systems which use diaphragm pumps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four solar photovoltaic (PV) powered diaphragm pumps were tested at different simulated pumping depths at the USDA-ARS Conservation and Production Research Laboratory near Bushland, Texas. Two of the pumps were designed for intermediate pumping depths (30 to 70 meters), and the other two pumps were...

  7. High-power, efficient, semiconductor saturable absorber mode-locked Yb:KGW bulk laser.

    PubMed

    Kisel, V E; Rudenkov, A S; Pavlyuk, A A; Kovalyov, A A; Preobrazhenskii, V V; Putyato, M A; Rubtsova, N N; Semyagin, B R; Kuleshov, N V

    2015-06-15

    A high-power, diode-pumped, semiconductor saturable absorber mode-locked Yb(5%):KGW bulk laser was demonstrated with high optical-to-optical efficiency. Average output power as high as 8.8 W with optical-to-optical efficiency of 37.5% was obtained for Nm-polarized laser output with 162 fs pulse duration and 142 nJ pulse energy at a pulse repetition frequency of 62 MHz. For Np polarization, 143 fs pulses with pulse energy of 139 nJ and average output power of up to 8.6 W with optical-to-optical efficiency of 31% were generated. PMID:26076242

  8. Threshold pump power of a solar-pumped dye laser

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

    1988-01-01

    Threshold solar power for dye laser pumping has been determined by measuring the gain of a rhodamine 6G dye laser amplifier at various solar-simulated irradiances on an amplifier cell. The measured threshold was 20,000 solar constants (2.7 kW/sq cm) for the dye volume of 2 x 5 x 40 cu mm and the optimum dye concentration of 0.001 M. The threshold is about one-third of that achievable with a high-intensity solar concentrator.

  9. Hydraulic gas pump: A discussion of its power usage

    SciTech Connect

    Amani, M.

    1995-12-31

    This paper presents the results of a study that compares the theoretically calculated power consumption of a Hydraulic Gas Pump, rod pumps, and electric submersible pumps. The results indicate that, depending on the flowing bottomhole pressure of a well, a Hydraulic Gas Pump can have lower power costs than a rod pump or a submersible pump. The author presents a method for calculating the power cost of a Hydraulic Gas Pump and discusses the relationship of the power cost of this pump to the flowing bottomhole pressure. Several graphs compare the calculated power consumption of a rod pump, submersible pump, and Hydraulic Gas Pump for well depths ranging between 6,000 and 10,000 feet; flowing bottomhole pressure ranging between 500 and 2,000 psi; and production rates of 300 and 500 BLPD.

  10. LD-end-pumped passively Q-switched Nd:YAG ceramic laser with single wall carbon nanotube saturable absorber

    NASA Astrophysics Data System (ADS)

    Li, C. Y.; Bo, Y.; Zong, N.; Wang, Y. G.; Jiang, B. X.; Pan, Y. B.; Niu, G.; Fan, Z. W.; Peng, Q. J.; Cui, D. F.; Xu, Z. Y.

    2012-10-01

    We report on a LD-end-pumped passively Q-switched Nd:YAG ceramic laser by using a novel single wall carbon nanotube saturable absorber (SWCNT-SA). The SWCNT wafer was fabricated by electric Arc discharge method on quartz substrate with absorption wavelength of 1064 nm. We firstly investigated the continuous wave (CW) laser performance and scattering properties of Nd:YAG ceramic sample. For the case of passively Q-switched operation, a maximum output power of 376 mW was obtained at an incident pump power of 8.68 W at 808 nm, corresponding to an optical-optical conversion efficiency of 4.3%. The repetition rate as the increase of pump power varied from 14 to 95 kHz. The minimum pulse duration of 1.2 μs and maximum pulse energy of 4.5 μJ was generated at a repetition rate of 31.8 kHz.

  11. Bidirectional pumped high power Raman fiber laser.

    PubMed

    Xiao, Q; Yan, P; Li, D; Sun, J; Wang, X; Huang, Y; Gong, M

    2016-03-21

    This paper presents a 3.89 kW 1123 nm Raman all-fiber laser with an overall optical-to-optical efficiency of 70.9%. The system consists of a single-wavelength (1070nm) seed and one-stage bidirectional 976 nm non-wavelength-stabilized laser diodes (LDs) pumped Yb-doped fiber amplifier. The unique part of this system is the application of non-wavelength-stabilized LDs in high power bidirectional pumping configuration fiber amplifier via refractive index valley fiber combiners. This approach not only increases the pump power, but also shortens the length of fiber by avoiding the usage of multi-stage amplifier. Through both theoretical research and experiment, the bidirectional pumping configuration presented in this paper proves to be able to convert 976 nm pump laser to 1070 nm laser via Yb3+ transfer, which is then converted into 1123 nm Raman laser via the first-order Raman effect without the appearance of any higher-order Raman laser. PMID:27136862

  12. Livestock water pumping with wind and solar power

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments in pumping technologies have allowed for efficient use of renewable energies like wind and solar to power new pumps for remote water pumping. A helical type, positive displacement pump was developed a few years ago and recently modified to accept input from a variable power sourc...

  13. 21 CFR 884.5160 - Powered breast pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered breast pump. 884.5160 Section 884.5160... § 884.5160 Powered breast pump. (a) Identification. A powered breast pump in an electrically powered suction device used to express milk from the breast. (b) Classification. Class II (performance standards)....

  14. 21 CFR 884.5160 - Powered breast pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered breast pump. 884.5160 Section 884.5160... § 884.5160 Powered breast pump. (a) Identification. A powered breast pump in an electrically powered suction device used to express milk from the breast. (b) Classification. Class II (performance standards)....

  15. 21 CFR 884.5160 - Powered breast pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered breast pump. 884.5160 Section 884.5160... § 884.5160 Powered breast pump. (a) Identification. A powered breast pump in an electrically powered suction device used to express milk from the breast. (b) Classification. Class II (performance standards)....

  16. 21 CFR 884.5160 - Powered breast pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered breast pump. 884.5160 Section 884.5160... § 884.5160 Powered breast pump. (a) Identification. A powered breast pump in an electrically powered suction device used to express milk from the breast. (b) Classification. Class II (performance standards)....

  17. 21 CFR 884.5160 - Powered breast pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered breast pump. 884.5160 Section 884.5160... § 884.5160 Powered breast pump. (a) Identification. A powered breast pump in an electrically powered suction device used to express milk from the breast. (b) Classification. Class II (performance standards)....

  18. Diode-pumped passively Q-switched Nd:YVO4 green laser with a periodically poled KTP and Cr4+:YAG saturable absorber.

    PubMed

    Li, Guiqiu; Zhao, Shengzhi; Yang, Kejian; Li, Dechun

    2006-03-10

    A diode-pumped passively Q-switched Nd:YVO4 green laser with a periodically poled KTP and Cr4+:YAG saturable absorber is realized. The dependences of pulse repetition rate, pulse energy, pulse width, and peak power on incident pump power are measured for the generated green-light pulses. A rate-equation model is introduced to theoretically analyze the results obtained in the experiment, in which the spatial distribution of the intracavity photon density is taken into account. The numerical solutions of the rate equations agree with the experimental results. PMID:16572700

  19. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    NASA Astrophysics Data System (ADS)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

    1994-11-29

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  1. Switchable nonlinear metasurfaces for absorbing high power surface waves

    NASA Astrophysics Data System (ADS)

    Kim, Sanghoon; Wakatsuchi, Hiroki; Rushton, Jeremiah J.; Sievenpiper, Daniel F.

    2016-01-01

    We demonstrate a concept of a nonlinear metamaterial that provides power dependent absorption of incident surface waves. The metasurface includes nonlinear circuits which transform it from a low loss to high loss state when illuminated with high power waves. The proposed surface allows low power signals to propagate but strongly absorbs high power signals. It can potentially be used on enclosures for electric devices to protest against damage. We experimentally verify that the nonlinear metasurface has two distinct states controlled by the incoming signal power. We also demonstrate that it inhibits the propagation of large signals and dramatically decreases the field that is leaked through an opening in a conductive enclosure.

  2. Experimental investigation of solar powered diaphragm and helical pumps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...

  3. Dynamic operations of a dye laser with a saturable absorber: pumping anisotropy and orientational relaxation

    NASA Astrophysics Data System (ADS)

    Gaisenok, V. A.; Krylov, G. G.; Sergeyev, S. V.

    1994-04-01

    Coupled oscillators nonlinear dynamics was found for a dye laser with a saturable absorber and polarized pumping. It has been shown that two coupled cross-linearly polarized modes demonstrate the Bar-Eli effect, when excitation conditions for them are different. As a result, output energy of laser emission stops oscillating and stabilize at a constant steady state. When excitation conditions for them are the same, a new type of asymmetrical auto-oscillations for two modes arises. In addition it was emphasized that orientational relaxation processes (radiationless energy transfer or Brownian rotation of molecules) in an active medium transform asymmetrical auto-oscillations to symmetrical ones.

  4. Gold nanorods as the saturable absorber for a diode-pumped nanosecond Q-switched 2  μm solid-state laser.

    PubMed

    Huang, Haitao; Li, Min; Liu, Pian; Jin, Lin; Wang, Hui; Shen, Deyuan

    2016-06-15

    Gold nanorods (GNRs) with an average aspect ratio of 15 were experimentally exploited as the 2 μm saturable absorber in a laser diode pumped Tm:YAG laser for the first time, to the best of our knowledge. Q-switched pulses with a maximum average output power of 380 mW, a minimum pulse width of 796 ns, and a pulse repetition rate of 77 kHz were achieved under the LD pump power of 6.2 W. Our results indicate that GNRs with a large aspect ratio are promising saturable absorbers in the 2 μm wavelength region. PMID:27304267

  5. Compact diode-directly-pumped passively mode-locked TEM00 Nd:GdVO4 laser at 1341 nm using a semiconductor saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Liu, K.; Li, F. Q.; Liu, Y.; Cao, D.; Bo, Y.; Peng, Q. J.; Cui, D. F.; Zhang, J. Y.; Xu, Z. Y.

    2011-11-01

    We report on a compact 880-nm diode-directly-pumped passively mode-locked TEM00 Nd:GdVO4 laser at 1341 nm with a semiconductor saturable absorber mirror (SESAM) for the first time. Under the absorbed pump power of 14.6 W, the maximum output power of 1.27 W was obtained at the repetition rate of 85.3 MHz with the pulse width of 45.3 ps, corresponding to an optical-optical efficiency of 8.8% and the slope efficiency of 33.3%, respectively. The beam quality factor was measured to be M 2 = 1.18, indicating a TEM00 mode.

  6. Absorber and gain chip optimization to improve performance from a passively modelocked electrically pumped vertical external cavity surface emitting laser

    SciTech Connect

    Zaugg, C. A. Mangold, M.; Pallmann, W. P.; Golling, M.; Tilma, B. W.; Keller, U.; Gronenborn, S.; Moench, H.; Weichmann, U.; Miller, M.

    2014-03-24

    We present an electrically pumped vertical-external-cavity surface-emitting laser (EP-VECSEL) modelocked with a semiconductor saturable absorber mirror (SESAM) with significantly improved performance. In different cavity configurations, we present the shortest pulses (2.5 ps), highest average output power (53.2 mW), highest repetition rate (18.2 GHz), and highest peak power (4.7 W) to date. The simple and low-cost concept of EP-VECSELs is very attractive for mass-market applications such as optical communication and clocking. The improvements result from an optimized gain chip from Philips Technologie GmbH and a SESAM, specifically designed for EP-VECSELs. For the gain chip, we found a better trade-off between electrical and optical losses with an optimized doping scheme in the substrate to increase the average output power. Furthermore, the device's bottom contact diameter (60 μm) is smaller than the oxide aperture diameter (100 μm), which favors electro-optical conversion into a TEM{sub 00} mode. Compared to optically pumped VECSELs we have to increase the field enhancement in the active region of an EP-VECSEL which requires a SESAM with lower saturation fluence and higher modulation depth for modelocking. We therefore used a resonant quantum well SESAM with a 3.5-pair dielectric top-coating (SiN{sub x} and SiO{sub 2}) to enhance the field in the absorber at the lasing wavelength of 980 nm. The absorption bandedge at room temperature is detuned (965 nm) compared to the resonance (980 nm), which enables temperature-tuning of the modulation depth and saturation fluence from approximately 2.5% up to 15% and from 20 μJ/cm{sup 2} to 1.1 μJ/cm{sup 2}, respectively.

  7. Absorber and gain chip optimization to improve performance from a passively modelocked electrically pumped vertical external cavity surface emitting laser

    NASA Astrophysics Data System (ADS)

    Zaugg, C. A.; Gronenborn, S.; Moench, H.; Mangold, M.; Miller, M.; Weichmann, U.; Pallmann, W. P.; Golling, M.; Tilma, B. W.; Keller, U.

    2014-03-01

    We present an electrically pumped vertical-external-cavity surface-emitting laser (EP-VECSEL) modelocked with a semiconductor saturable absorber mirror (SESAM) with significantly improved performance. In different cavity configurations, we present the shortest pulses (2.5 ps), highest average output power (53.2 mW), highest repetition rate (18.2 GHz), and highest peak power (4.7 W) to date. The simple and low-cost concept of EP-VECSELs is very attractive for mass-market applications such as optical communication and clocking. The improvements result from an optimized gain chip from Philips Technologie GmbH and a SESAM, specifically designed for EP-VECSELs. For the gain chip, we found a better trade-off between electrical and optical losses with an optimized doping scheme in the substrate to increase the average output power. Furthermore, the device's bottom contact diameter (60 μm) is smaller than the oxide aperture diameter (100 μm), which favors electro-optical conversion into a TEM00 mode. Compared to optically pumped VECSELs we have to increase the field enhancement in the active region of an EP-VECSEL which requires a SESAM with lower saturation fluence and higher modulation depth for modelocking. We therefore used a resonant quantum well SESAM with a 3.5-pair dielectric top-coating (SiNx and SiO2) to enhance the field in the absorber at the lasing wavelength of 980 nm. The absorption bandedge at room temperature is detuned (965 nm) compared to the resonance (980 nm), which enables temperature-tuning of the modulation depth and saturation fluence from approximately 2.5% up to 15% and from 20 μJ/cm2 to 1.1 μJ/cm2, respectively.

  8. Designing Self-powered Nanomotors and Pumps

    NASA Astrophysics Data System (ADS)

    Sen, Ayusman

    Self-powered nano and microscale moving systems are currently the subject of intense interest due in part to their potential applications in nanomachinery, nanoscale assembly, robotics, fluidics, and chemical/biochemical sensing. We will demonstrate that one can build autonomous nanomotors over a wide range of length-scales ``from scratch'' that mimic biological motors by using catalytic reactions to create forces based on chemical gradients. These motors are autonomous in that they do not require external electric, magnetic, or optical fields as energy sources. Instead, the input energy is supplied locally and chemically. These ''bots'' can be directed by information in the form of chemical and light gradients. Furthermore, we have developed systems in which chemical secretions from the translating nano/micromotors initiate long-range, collective interactions among themselves. This behavior is reminiscent of quorum sensing organisms that swarm in response to a minimum threshold concentration of a signaling chemical. In addition, an object that moves by generating a continuous surface force in a fluid can, in principle, be used to pump the fluid by the same catalytic mechanism. Thus, by immobilizing the nano/micromotors, we have developed nano/microfluidic pumps that transduce energy catalytically. These non-mechanical pumps provide precise control over flow rate without the aid of an external power source and are capable of turning on in response to specific analytes in solution.

  9. Performance of a small wind powered water pumping system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lorentz helical pumps (Henstedt-Ulzburg, Germany) have been powered by solar energy for remote water pumping applications for many years, but from October 2005 to March 2008 a Lorentz helical pump was powered by wind energy at the USDA-ARS Conservation and Production Research Laboratory (CPRL) near ...

  10. High power L-band mode-locked fiber laser based on topological insulator saturable absorber.

    PubMed

    Meng, Yichang; Semaan, Georges; Salhi, Mohamed; Niang, Alioune; Guesmi, Khmaies; Luo, Zhi-Chao; Sanchez, Francois

    2015-09-01

    We demonstrate a passive mode-locked Er:Yb doped double-clad fiber laser using a microfiber-based topological insulator (Bi(2)Se(3)) saturable absorber (TISA). By optimizing the cavity loss and output coupling ratio, the mode-locked fiber laser can operate in L-band with high average output power. With the highest pump power of 5 W, 91st harmonic mode locking of soliton bunches with average output power of 308 mW was obtained. This is the first report that the TISA based erbium-doped fiber laser operating above 1.6 μm and is also the highest output power yet reported in TISA based passive mode-locked fiber laser. PMID:26368409

  11. Diode-pumped Nd:YAG ceramic laser at 946 nm passively Q-switched with a Cr 4+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Li, Ping; Zhang, Huanian; Chen, Xiaohan; Wang, Qingpu

    2012-04-01

    We demonstrate a diode-pumped Nd:YAG ceramic laser with emission at 946 nm that is passively Q-switched by single-crystal Cr 4+:YAG saturable absorber. An average output power of 1.7 W is measured under 18.4 W of incident power using an output mirror with transmission T=4%. The corresponding optical-to-optical efficiency is 9.2%. The laser runs at a pulse repetition rate of 120 kHz and delivers pulses with energy of 14 μJ and duration of 80 ns, which corresponds to a peak power of 175 W.

  12. CFD research on runaway transient of pumped storage power station caused by pumping power failure

    NASA Astrophysics Data System (ADS)

    Zhang, L. G.; Zhou, D. Q.

    2013-12-01

    To study runaway transient of pumped storage power station caused by pumping power failure, three dimensional unsteady numerical simulations were executed on geometrical model of the whole flow system. Through numerical calculation, the changeable flow configuration and variation law of some parameters such as unit rotate speed,flow rate and static pressure of measurement points were obtained and compared with experimental data. Numerical results show that runaway speed agrees well with experimental date and its error was 3.7%. The unit undergoes pump condition, brake condition, turbine condition and runaway condition with flow characteristic changing violently. In runaway condition, static pressure in passage pulses very strongly which frequency is related to runaway speed.

  13. High-Power Nd:GdVO4 Innoslab Continuous-Wave Laser under Direct 880 nm Pumping

    NASA Astrophysics Data System (ADS)

    Deng, Bo; Zhang, Heng-Li; Xu, Liu; Mao, Ye-Fei; He, Jing-Liang; Xin, Jian-Guo

    2014-11-01

    A high-power cw end-pumped laser device is demonstrated with a slab crystal of Nd:GdVO4 operating at 1063 nm. Diode laser stacks at 880 nm are used to pump Nd:GdVO4 into emitting level 4F3/2. The 149 W output power is presented when the absorbed pump power is 390 W and the optical-to-optical conversion efficiency is 38.2%. When the output power is 120 W, the M2 factors are 2.3 in both directions. Additionally, mode overlap inside the resonator is analyzed to explain the beam quality deterioration.

  14. Flashlamp pumped oscillator-amplifier Nd:YAG system mode-locked using multiple quantum well saturable absorber

    NASA Astrophysics Data System (ADS)

    Kubecek, Vaclav; Jelinkova, Helena; Dombrovsky, Andrej; Diels, Jean-Claude; Stintz, Andreas

    2004-09-01

    We report on flashlamp pumped oscillator - three amplifiers Nd:YAG picosecond laser system in which the liquid saturable dye used for passive mode locking is replaced by semiconductor saturable absorber with multiple quantum well (MQW) structure. This element placed at Brewster angle inside a laser resonator had 100 layers of absorber and therefore it has high nonlinearity and is suitable for high power Q-switched and mode locked operation. The short pulse train from oscillator contained only 5-6 pulses with total energy of 3 mJ in single transversal mode, the pulse duration was 80 ps. After amplification, the maximum energy of the pulse train was 180 mJ. In the regime of the amplification of a single selected pulse the energy on the output of the third amplifier was 50 mJ. Operation of the oscillator in active-passive regime of mode locking using an additional acousto-optic mode-locker leads to improvement of reproducibility and stability of output parameters.

  15. Nuclear power plant safety related pump issues

    SciTech Connect

    Colaccino, J.

    1996-12-01

    This paper summarizes of a number of pump issues raised since the Third NRC/ASME Symposium on Valve and Pump Testing in 1994. General issues discussed include revision of NRC Inspection Procedure 73756, issuance of NRC Information Notice 95-08 on ultrasonic flow meter uncertainties, relief requests for tests that are determined by the licensee to be impractical, and items in the ASME OM-1995 Code, Subsection ISTB, for pumps. The paper also discusses current pump vibration issues encountered in relief requests and plant inspections - which include smooth running pumps, absolute vibration limits, and vertical centrifugal pump vibration measurement requirements. Two pump scope issues involving boiling water reactor waterlog and reactor core isolation cooling pumps are also discussed. Where appropriate, NRC guidance is discussed.

  16. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-12-03

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  17. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  18. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  19. High power cooled mini-DIL pump lasers

    NASA Astrophysics Data System (ADS)

    Liang, Bo; Zayer, Nadhum; Chen, Bob; He, Dylan; Pliska, Tomas

    2009-11-01

    The miniature dual-inline (mini-DIL) pump laser becomes more attactive for compact optical amplifiers designs due to the advantage of smaller footprint, lower power consumption and lower cost. In this paper we report the development of a new generation of small form factor, high power "cooled" mini-DIL 980-nm pump lasers module for compact EDFA application.

  20. 14. FLOODED POWER HOUSE FOUNDATION EXCAVATION BEING PUMPED OUT. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. FLOODED POWER HOUSE FOUNDATION EXCAVATION BEING PUMPED OUT. NOTE KEYS IN FOREBAY ABUTMENT TO INTERLOCK WITH POWER HOUSE FOUNDATION, March 1918. - Dam No. 5 Hydroelectric Plant, On Potomac River, Hedgesville, Berkeley County, WV

  1. Power absorbed during whole-body vertical vibration: Effects of sitting posture, backrest, and footrest

    NASA Astrophysics Data System (ADS)

    Nawayseh, Naser; Griffin, Michael J.

    2010-07-01

    Previous studies have quantified the power absorbed in the seated human body during exposure to vibration but have not investigated the effects of body posture or the power absorbed at the back and the feet. This study investigated the effects of support for the feet and back and the magnitude of vibration on the power absorbed during whole-body vertical vibration. Twelve subjects were exposed to four magnitudes (0.125, 0.25, 0.625, and 1.25 m s -2 rms) of random vertical vibration (0.25-20 Hz) while sitting on a rigid seat in four postures (feet hanging, maximum thigh contact, average thigh contact, and minimum thigh contact) both with and without a rigid vertical backrest. Force and acceleration were measured at the seat, the feet, and the backrest to calculate the power absorbed at these three locations. At all three interfaces (seat, feet, and back) the absorbed power increased in proportion to the square of the magnitude of vibration, with most power absorbed from vibration at the seat. Supporting the back with the backrest decreased the power absorbed at the seat at low frequencies but increased the power absorbed at high frequencies. Supporting the feet with the footrest reduced the total absorbed power at the seat, with greater reductions with higher footrests. It is concluded that contact between the thighs and the seat increases the power absorbed at the seat whereas a backrest can either increase or decrease the power absorbed at the seat.

  2. Liquid-Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.

    2007-01-01

    Multiple liquid-metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated with incorporation into a reactor system. The thermoelectric pump is recommended for inclusion in the planned system at NASA MSFC based on its relative simplicity, low power supply mass penalty, flight heritage, and the promise of increased pump efficiency over earlier flight pump designs through the use of skutterudite thermoelectric elements.

  3. High-power diode-pumped passively mode-locked Yb:YAG lasers.

    PubMed

    Aus der Au, J; Schaer, S F; Paschotta, R; Hönninger, C; Keller, U; Moser, M

    1999-09-15

    We obtained 74-kW peak power and 3.5-W average output power in 1-ps pulses from a diode-pumped Yb:YAG laser at 1030 nm that was passively mode locked with a semiconductor saturable-absorber mirror. Another laser produced 57-kW peak power and as much as 8.1-W average output power in 2.2-ps pulses, split into two nearly diffraction-limited beams (M(2)<1.2) . To our knowledge, these are by far the highest reported peak and average output powers from a diode-pumped mode-locked laser in this pulse-duration regime. PMID:18079780

  4. Experimental and theoretical study of a laser-diode-pumped passively Q-switched intracavity-frequency-doubled Nd:GdVO4/KTP red laser with V:YAG saturable absorber.

    PubMed

    Xu, Chao; Li, Guiqiu; Zhao, Shengzhi; Li, Xin; Du, Guolong; Yin, Lei

    2011-09-10

    A laser-diode-pumped passively Q-switched intracavity-frequency-doubled Nd:GdVO4/KTP red laser with V:YAG saturable absorber is realized in a V-type resonator. The dependences of the pulse repetition rate, pulse width, single-pulse energy, and peak power on the incident pump power are measured and contrasted. By assuming the intracavity photon density and the initial population-inversion density to be Gaussian spatial distributions, the space-dependent rate equations of this laser are given. The numerical solutions of the rate equations are consistent with the experimental results. In order to optimize the described system, the variations of the pulse width, peak power, single-pulse energy, and laser efficiency with the initial transmission of the saturable absorber and the ratio of the laser beam radius to the pump beam radius are also calculated, respectively. PMID:21946991

  5. Carbon nanostructure-based saturable absorber mirror for a diode-pumped 500-MHz femtosecond Yb:KLu(WO4)2 laser.

    PubMed

    Choi, Sun Young; Kim, Jun Wan; Kim, Mi Hye; Yeom, Dong-Il; Hong, Byung Hee; Mateos, Xavier; Aguiló, Magdalena; Díaz, Francesc; Petrov, Valentin; Griebner, Uwe; Rotermund, Fabian

    2014-06-30

    We report a diode-pumped Yb:KLu(WO(4))(2) (Yb:KLuW) laser passively mode-locked by employing a carbon nanostructure-based multi-functional saturable absorber mirror. Two types of carbon nanostructures, single-walled carbon nanotubes (SWCNTs) and graphene, were deposited on a single dielectric mirror and applied both for stable mode-locking of the Yb:KLuW laser near 1050 nm in a compact cavity configuration. The carbon nanostructure mode-locked laser delivers 157-fs pulses with output powers of up to 85 mW at a repetition rate of 500 MHz. PMID:24977821

  6. A high-energy cladding-pumped 80 nanosecond Q-switched fiber laser using a tapered fiber saturable absorber

    NASA Astrophysics Data System (ADS)

    Moore, Sean W.; Soh, Daniel B. S.; Bisson, Scott E.; Patterson, Brian D.; Hsu, Wen L.

    2013-02-01

    We report a passively Q-switched all-fiber laser using a large mode area (LMA) Yb3+-doped fiber cladding-pumped at 915 nm and an unpumped single-mode Yb3+-doped fiber as the saturable absorber (SA). The saturable absorber and gain fibers were first coupled with a free-space telescope to better study the composite system, and then fusion spliced with fiber tapers to match the mode field diameters. ASE generated in the LMA gain fiber preferentially bleaches the SA fiber before depleting the gain, thereby causing the SA fiber to act as a passive saturable absorber. Using this scheme we first demonstrate a Q-switched oscillator with 40 μJ 79 ns pulses at 1026 nm using a free-space taper, and show that pulses can be generated from 1020 nm to 1040 nm. We scale the pulse energy to 0.40 mJ using an Yb3+-doped cladding pumped fiber amplifier. Experimental studies in which the saturable absorber length, pump times, and wavelengths are independently varied reveal the impact of these parameters on laser performance. Finally, we demonstrate 60 μJ 81 ns pulses at 1030 nm in an all fiber architecture using tapered mode field adaptors to match the mode filed diameters of the gain and SA fibers.

  7. Solar pumped laser technology options for space power transmission

    NASA Technical Reports Server (NTRS)

    Conway, E. J.

    1986-01-01

    An overview of long-range options for in-space laser power transmission is presented. The focus is on the new technology and research status of solar-pumped lasers and their solar concentration needs. The laser options include gas photodissociation lasers, optically-pumped solid-state lasers, and blackbody-pumped transfer lasers. The paper concludes with a summary of current research thrusts.

  8. Liquid Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Multiple liquid metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to rest prototypical space nuclear surface power system components. Conduction, induction and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated with incorporation into a reactor system. A thermoelectric electromagnetic pump is selected as the best option for use in NASA-MSFC's Fission Surface Power-Primary Test Circuit reactor simulator based on its relative simplicity, low power supply mass penalty, flight heritage, and the promise of increased pump efficiency over those earlier pump designs through the use of skutterudite thermoelectric elements.

  9. High power, diode pumped Er:YAG for dentistry

    NASA Astrophysics Data System (ADS)

    Hagen, C.; Heinrich, A.; Nussbaumer, B.

    2011-03-01

    Pantec Medical Laser presents a diode pumped Er:YAG laser for dental and hard tissue applications. The diode pumped laser is practically maintenance free and ensures reliable operation over several thousand hours. The high repetition rate with up to 15 W average output power, allows treatments otherwise not feasible with low repetition rate, lamp pumped Er:YAG systems. The variable pulse duration of 10 to 200 μs combined with the good beam quality ensures precise and fast treatment. First results on enamel ablation as well as the power scalability of the technology to 200 mJ and 30 W average power are also shown.

  10. An all-fiber high-energy cladding-pumped 93 nanosecond Q-switched fiber laser using an Y 3+-doped fiber saturable absorber

    NASA Astrophysics Data System (ADS)

    Moore, Sean W.; Patterson, Brian D.; Soh, Daniel B.; Bisson, Scott E.

    2014-03-01

    We report an all-fiber passively Q-switched laser using a large mode area (LMA) Yb3+ -doped fiber claddingpumped at 915 nm and an unpumped single-mode (SM) Yb3+-doped fiber as the saturable absorber (SA). The saturable absorber SM fiber and LMA gain fiber were coupled with a fiber taper designed to match the fundamental spatial mode of the LMA fiber and the expanded LP01 mode of the single mode fiber. The amplified spontaneous (ASE) intensity propagating in the single mode SA saturates the absorption before the onset of gain depletion in the pumped fiber, switching the fiber cavity to a high Q-state and producing a pulse. Using this scheme we demonstrate a Q-switched all-fiber oscillator with 32 μJ 93 ns pulses at 1030 nm. The associated peak power is nearly two orders of magnitude larger than that reported in previous experimental studies using a single Yb+3 saturable absorber fiber. The pulse energy was amplified to 0.230 mJ using an Yb3+-doped cladding pumped fiber amplifier fusion spliced to the fiber oscillator, increasing the energy by eight fold while preserving the all-fiber architecture.

  11. Low power, constant-flow air pump systems

    SciTech Connect

    Polito, M.D.; Albert, B.

    1994-01-01

    A rugged, yet small and lightweight constant-flow air pump system has been designed. Flow control is achieved using a novel approach which is three times more power efficient than previous designs. The resultant savings in battery size and weight makes these pumps ideal for sampling air on balloon platforms. The pump package includes meteorological sensors and an onboard computer that stores time and sensor data and turns the constant-flow pump circuit on/off. Some applications of these systems are also presented in this report.

  12. Power scaling of directly dual-end-pumped Nd:GdVO4 laser using grown-together composite crystal.

    PubMed

    Li, XuDong; Yu, Xin; Chen, Fei; Yan, RenPeng; Luo, Ming; Yu, JunHua; Chen, DeYing

    2010-03-29

    Power scaling of end-pumped Nd:GdVO(4) laser was realized by direct pumping, grown-together composite crystal and dual-end-pumping. A maximum CW output power of 46.0W with M(2)<1.1 was achieved, corresponding to a slope efficiency of 71.1% to absorbed pump power. In A-O Q-switch operation, peak power of 304.1kW, 58.6kW and 23.8kW, pulse width of 7.2ns, 11.3ns and 16.2ns were obtained at the repetition rates of 10kHz, 50kHz and 100kHz, respectively. PMID:20389763

  13. High-power passively Q-switched Nd:KGW laser pumped at 877 nm

    NASA Astrophysics Data System (ADS)

    Huang, K.; Ge, W. Q.; Zhao, T. Z.; Feng, C. Y.; Yu, J.; He, J. G.; Xiao, H.; Fan, Z. W.

    2016-06-01

    In this work, we demonstrate, for the first time, a high-power passively Q-switched Ng-cut Nd3+:KGd(WO4)2/Cr4+:YAG laser pumped at 877 nm. The maximum average output power of ~1.6 W is obtained at the pump power of 5.22 W, when a saturable absorber with 98 % of initial transmission is used. The corresponding pulse energy is up to 16 µJ. The maximum pulse energy of 25.3 µJ is achieved at a repetition rate of 59 kHz, by employing a saturable absorber with 95 % of initial transmission. The corresponding pulse width and average output power are 89.0 ns and 1.5 W, respectively. A careful cavity design and a good thermal management ensure nearly TEM00 output with M 2 ≤ 1.22 within the whole range of operation in both N p and N m directions at 877 nm pump.

  14. Pump power dependence of second order correlation in nondegenerate SPDC

    NASA Astrophysics Data System (ADS)

    Kim, Charles; Kanner, Gary

    2009-08-01

    We observed the second order correlation peak for nondegenerate spontaneous parametric down conversion (SPDC) of a pulsed pump at 532 nm into 810 nm and 1550 nm entangled beams. We used a Si avalanche photodiode (APD) to detect the 810 nm photons, and an InGaAs APD to detect those at 1550 nm. We defined both a visibility and signal-to-noise ratio (SNR) based on the data, which were obtained at various pump powers. In contrast to classical imaging systems, for which SNR increases monotonically with transmitted power, the SNR for the correlation peak in our setup exhibited a gradual decay as the pump power increased. We derived an empirical relation for the SNR, which was inversely proportional to the square root of pump power.

  15. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  16. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  17. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  18. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  19. 21 CFR 878.4780 - Powered suction pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4780 Powered suction pump. (a... support system. The device may be used during surgery in the operating room or at the patient's...

  20. Design and installation package for a solar powered pump

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design and installation procedures of a solar powered pump developed by Calmac Manufacturing Company are presented. Subsystem installation, operation and maintenance requirements, subsystem performance specifications, and detailed design drawings are included.

  1. Measurement of SRS reactor recirculation pump performance using pump motor power

    SciTech Connect

    Whitehouse, J.C.

    1994-03-01

    In order to accurately predict reactor hydraulic behavior during a hypothetical Loss-of-Coolant-Accident (LOCA) the performance of reactor coolant pumps under off-design conditions must be understood. The LOCA of primary interest for the Savannah River Site (SRS) production reactors involves the aspiration of air into the recirculated heavy water flow as reactor tank inventory is lost (system temperatures are too low to result in significant flashing of water coolant into steam). Entrained air causes degradation in the performance of the large recirculation pumps. The amount of degradation is a parameter used in computer codes which predict the course of the accident. This paper describes the analysis of data obtained during in-reactor simulated LOCA tests, and presents the head degradation curve for the SRS reactor recirculation pumps. The greatest challenge of the analysis was to determine a reasonable estimate of mixture density at the pump suction. Specially designed three-beam densitometers were used to determine mixture density. Since it was not feasible to place them in the most advantageous location the measured pump motor power, along with other techniques (pressure corrected gamma densitometer void fraction), were used to calculate the average mixture density at the pump impeller. These techniques provided good estimates of pump suction mixture density. Measurements from more conventional instruments were used to arrive at the value of pump two-component head over a wide range of flows. The results were significantly different from previous work with commercial reactor recirculation pumps.

  2. High power tandem-pumped thulium-doped fiber laser.

    PubMed

    Wang, Yao; Yang, Jianlong; Huang, Chongyuan; Luo, Yongfeng; Wang, Shiwei; Tang, Yulong; Xu, Jianqiu

    2015-02-01

    We propose a cascaded tandem pumping technique and show its high power and high efficient operation in the 2-μm wavelength region, opening up a new way to scale the output power of the 2-μm fiber laser to new levels (e.g. 10 kW). Using a 1942 nm Tm(3+) fiber laser as the pump source with the co- (counter-) propagating configuration, the 2020 nm Tm(3+) fiber laser generates 34.68 W (35.15W) of output power with 84.4% (86.3%) optical-to-optical efficiency and 91.7% (92.4%) slope efficiency, with respect to launched pump power. It provides the highest slope efficiency reported for 2-μm Tm(3+)-doped fiber lasers, and the highest output power for all-fiber tandem-pumped 2-μm fiber oscillators. This system fulfills the complete structure of the proposed cascaded tandem pumping technique in the 2-μm wavelength region (~1900 nm → ~1940 nm → ~2020 nm). Numerical analysis is also carried out to show the power scaling capability and efficiency of the cascaded tandem pumping technique. PMID:25836159

  3. Passively Q-switched flashlamp pumped Nd:YAG laser using liquid graphene oxide as saturable absorber

    NASA Astrophysics Data System (ADS)

    Adnan, N. N.; Bidin, N.; Taib, N. A. M.; Haris, H.; Fakaruddin, M.; Hashim, A. M.; Krishnan, G.; Harun, S. W.

    2016-06-01

    The performance of passively Q-switched Nd:YAG laser operating at 1060 nm is demonstrated using liquid graphene oxide (GO) composite solution as saturable absorber for the first time. The Q-switched Nd:YAG laser is pumped by a xenon flashlamp. The GO was prepared using the simplified Hummer's method and then mixed with polyethylene oxide to form a composite solution. The Q-switched pulsed laser operates at wavelength of 1064.5 nm with a threshold pump energy of 33.64 J. The maximum output Q-switched laser energy of 41.6 mJ achieved at the maximum pump energy of 81 J. The corresponding pulse width is 98.67 ns.

  4. Low power integrated pumping and valving arrays for microfluidic systems

    DOEpatents

    Krulevitch, Peter A.; Benett, William J.; Rose, Klint A.; Hamilton, Julie; Maghribi, Mariam

    2006-04-11

    Low power integrated pumping and valving arrays which provide a revolutionary approach for performing pumping and valving approach for performing pumping and valving operations in microfabricated fluidic systems for applications such as medical diagnostic microchips. Traditional methods rely on external, large pressure sources that defeat the advantages of miniaturization. Previously demonstrated microfabrication devices are power and voltage intensive, only function at sufficient pressure to be broadly applicable. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a microchannel, analogous to a microsyringe. When the pressure source is activated, the polymer plug slides within the microchannel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as microvalves.

  5. Double clad YAG crystalline fiber waveguides for diode pumped high power lasing

    NASA Astrophysics Data System (ADS)

    Mu, Xiaodong; Meissner, Stephanie; Meissner, Helmuth; Yu, Anthony W.

    2014-02-01

    Double-clade crystalline fiber waveguide (CFW) has been produced by using adhesive-free bond (AFB®) technology. The waveguide consists of a 1 at.% Yb:YAG core, un-doped YAG inner cladding and ceramic spinel outer cladding. It is a direct analog of the conventional double-clad glass fiber laser in the crystal domain. Signal gain of 45 or 16.5 dB has been measured in a preliminary master oscillator power amplifier (MOPA) experiment. Due to the high laser gain and the weak Fresnel reflection at the uncoated waveguide ends, the CFW even starts self-lasing above a certain pump power. Laser output power of 4 W in the backward propagation direction has been measured for input pump power of 44 W. After considering the same amount of forward propagated laser power, the laser efficiency to the absorbed pump power is estimated to be about 44%. In principle, CFW can have extremely large single mode area for high efficiency and high power laser applications. So far, Single mode area < 6700 μm2 has been demonstrated in Er:YAG CFWs.

  6. Application of reactor-pumped lasers to power beaming

    SciTech Connect

    Repetti, T.E.

    1991-10-01

    Power beaming is the concept of centralized power generation and distribution to remote users via energy beams such as microwaves or laser beams. The power beaming community is presently performing technical evaluations of available lasers as part of the design process for developing terrestrial and space-based power beaming systems. This report describes the suitability of employing a nuclear reactor-pumped laser in a power beaming system. Although there are several technical issues to be resolved, the power beaming community currently believes that the AlGaAs solid-state laser is the primary candidate for power beaming because that laser meets the many design criteria for such a system and integrates well with the GaAs photodiode receiver array. After reviewing the history and physics of reactor-pumped lasers, the advantages of these lasers for power beaming are discussed, along with several technical issues which are currently facing reactor-pumped laser research. The overriding conclusion is that reactor-pumped laser technology is not presently developed to the point of being technially or economically competitive with more mature solid-state technologies for application to power beaming. 58 refs.

  7. Application of reactor-pumped lasers to power beaming

    NASA Astrophysics Data System (ADS)

    Repetti, T. E.

    1991-10-01

    Power beaming is the concept of centralized power generation and distribution to remote users via energy beams such as microwaves or laser beams. The power beaming community is presently performing technical evaluations of available lasers as part of the design process for developing terrestrial and space-based power beaming systems. This report describes the suitability of employing a nuclear reactor-pumped laser in a power beaming system. Although there are several technical issues to be resolved, the power beaming community currently believes that the AlGaAs solid-state laser is the primary candidate for power beaming because that laser meets the many design criteria for such a system and integrates well with the GaAs photodiode receiver array. After reviewing the history and physics of reactor-pumped lasers, the advantages of these lasers for power beaming are discussed, along with several technical issues which are currently facing reactor-pumped laser research. The overriding conclusion is that reactor-pumped laser technology is not presently developed to the point of being technically or economically competitive with more mature solid-state technologies for application to power beaming.

  8. High power continuous-wave Alexandrite laser with green pump

    NASA Astrophysics Data System (ADS)

    Ghanbari, Shirin; Major, Arkady

    2016-07-01

    We report on a continuous-wave (CW) Alexandrite (Cr:BeAl2O4) laser, pumped by a high power green source at 532 nm with a diffraction limited beam. An output power of 2.6 W at 755 nm, a slope efficiency of 26%, and wavelength tunability of 85 nm have been achieved using 11 W of green pump. To the best of our knowledge, this is the highest CW output power of a high brightness laser pumped Alexandrite laser reported to date. The results obtained in this experiment can lead to the development of a high power tunable CW and ultrafast sources of the near-infrared or ultraviolet radiation through frequency conversion.

  9. 18. LOWER OIL ROOM DIABLO POWERHOUSE: GRAVITY OIL PUMPS POWERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. LOWER OIL ROOM DIABLO POWERHOUSE: GRAVITY OIL PUMPS POWERED BY LINCOLN AC MOTORS ON THE RIGHT AND TURBINE AIR DRY APPARATUS ON THE LEFT, 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  10. Solar-pumped laser for free space power transmission

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1989-01-01

    Laser power transmission; laser systems; space-borne and available lasers; 2-D and 1 MW laser diode array systems; technical issues; iodine solar pumped laser system; and laser power transmission applications are presented. This presentation is represented by viewgraphs only.

  11. Diode pumped alkali vapor lasers for high power applications

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Krupke, B.; Komashko, A.

    2008-02-01

    General Atomics has been engaged in the development of diode pumped alkali vapor lasers. We have been examining the design space looking for designs that are both efficient and easily scalable to high powers. Computationally, we have looked at the effect of pump bandwidth on laser performance. We have also looked at different lasing species. We have used an alexandrite laser to study the relative merits of different designs. We report on the results of our experimental and computational studies.

  12. Optimization of the circulating water pumping system in power plants

    SciTech Connect

    Lapray, J.F.; Griffiths, I.L.; Chedru, P.J.

    1996-12-31

    The correct operation of power plants is dependent on the function of its major systems. The pumping station supplying cooling water is one such element. Cooling water systems in fossil fired and nuclear power plants are fed by pumps that must, without fail, run intensively. A shut down would automatically lead to a shut down of the plant unit it serves., e.g., a reduction of power output. The role of such pumps and the associated system is crucial and therefore cannot be compared with a drainage or irrigation pumping station that also handles large flows at low total head pressures. Operational reliability is of the utmost importance in the main circulating water systems. Pumping stations have increased in size following the turbine size rise. At one time a capacity of 130,000 USGPM was considered large, today`s requirements can be in the order of 2,600,000 USGPM. However, it is not just size that has increased, modern environmental considerations and economics require greater efficiency in all aspects, reductions in energy consumed, water usage, maintenance costs, etc. The once relatively simple principles that were taken into consideration in choice of equipment are no longer adaptable to the scale of current requirements. Optimization of not just the pumps but the complete integrated system as a whole must be paramount. This paper attempts to address the optimization of the complete system.

  13. Raising the efficiency of intracavity laser pumping of selectively absorbing media

    SciTech Connect

    Aubakirov, R.G.; Murzin, A.G.; Fromzel, V.A.

    1983-09-01

    Conditions providing for maximum efficiency during intracavity laser pumping of active media have been analyzed. It is shown that the occasional parasitic oscillation shift of the pumping laser can be eliminated without any loss of laser pumping efficiency. An experimental study has been made on two possible energetically efficient methods of stabilizing the oscillation spectrum of a neodymium glass laser with an intracavity load of ytterbium-erbium glass: introduction of a small-base Fabry-Perot etalon into the cavity and use of mirrors with a sharp drop of the spectral characteristic as laser cavity mirrors. An optimum variant of the multilayered coating of such mirrors has been selected.

  14. Mechanisms for plasma formation during high power pumping of XPAL

    NASA Astrophysics Data System (ADS)

    Babaeva, Natalia Yu.; Zatsarinny, Oleg; Bartschat, Klaus; Kushner, Mark J.

    2014-02-01

    During operation of the excimer pumped alkali laser, XPAL, large densities of alkali excited states are produced. Through superelastic electron collisional relaxation of these states, any pre-existing electrons will be heated, leading to additional ionization. The end result is plasma formation. A first principles global model has been developed for the Ar/Cs XPAL system to investigate the possible formation of plasma during high repetition rate, high power pumping; and the consequences on laser performance. Four- and five-level pumping schemes were used to enable assessment of XPAL operating on the Cs(62P3/2) → Cs(62S1/2) (852 nm) and Cs(62P1/2) → Cs(62S1/2) (894 nm) transitions. The model was parameterized as a function of pump power, excitation frequency, cell temperature (Cs vapor pressure) and collision mixing agent (N2) mole fraction. We found that at sufficiently high operating temperature, pump power and repetition rate, plasma formation in excess of 1014-1016 cm-3 occurs, which potentially reduces laser output power by electron collisional mixing of the upper and lower laser levels.

  15. High power, high efficiency diode pumped Raman fiber laser

    NASA Astrophysics Data System (ADS)

    Glick, Yaakov; Fromzel, Viktor; Zhang, Jun; Dahan, Asaf; Ter-Gabrielyan, Nikolay; Pattnaik, Radha K.; Dubinskii, Mark

    2016-06-01

    We demonstrate a high power high efficiency Raman fiber laser pumped directly by a laser diode module at 976 nm. 80 Watts of CW power were obtained at a wavelength of 1020 nm with an optical-to-optical efficiency of 53%. When working quasi-CW, at a duty cycle of 30%, 85 W of peak power was produced with an efficiency of 60%. A commercial graded-index (GRIN) core fiber acts as the Raman fiber in a power oscillator configuration, which includes spectral selection to prevent generation of the 2nd Stokes. In addition, significant brightness enhancement of the pump beam is attained due to the Raman gain distribution profile in the GRIN fiber. To the best of our knowledge, this is the highest power Raman fiber laser directly pumped by laser diodes, which also exhibits a record efficiency for such a laser. In addition, it is the highest power Raman fiber laser (regardless of pumping source) demonstrated based on a GRIN fiber.

  16. High-power synchronously pumped femtosecond Raman fiber laser.

    PubMed

    Churin, D; Olson, J; Norwood, R A; Peyghambarian, N; Kieu, K

    2015-06-01

    We report a high-power synchronously pumped femtosecond Raman fiber laser operating in the normal dispersion regime. The Raman laser is pumped by a picosecond Yb(3+)-doped fiber laser. It produces highly chirped pulses with energy up to 18 nJ, average power of 0.76 W and 88% efficiency. The pulse duration is measured to be 147 fs after external compression. We observed two different regimes of operation of the laser: coherent and noise-like regime. Both regimes were experimentally characterized. Numerical simulations are in a good agreement with experimental results. PMID:26030549

  17. Quantum-dot saturable absorber and Kerr-lens mode-locked Yb:KGW laser with >450  kW of peak power.

    PubMed

    Akbari, R; Zhao, H; Fedorova, K A; Rafailov, E U; Major, A

    2016-08-15

    The hybrid action of quantum-dot saturable absorber and Kerr-lens mode locking in a diode-pumped Yb:KGW laser was demonstrated. Using a quantum-dot saturable absorber with a 0.7% (0.5%) modulation depth, the mode-locked laser delivered 90 fs (93 fs) pulses with 3.2 W (2.9 W) of average power at the repetition rate of 77 MHz, corresponding to 462 kW (406 kW) of peak power and 41 nJ (38 nJ) of pulse energy. To the best of our knowledge, this represents the highest average and peak powers generated to date from quantum-dot saturable absorber-based mode-locked lasers. PMID:27519085

  18. Electromagnetic pump stator frame having power crossover struts

    DOEpatents

    Fanning, Alan W.; Olich, Eugene E.

    1995-01-01

    A stator frame for an electromagnetic pump includes a casing joined to a hub by a plurality of circumferentially spaced apart struts. At least one electrically insulated power crossover lead extends through the hub, through a crossover one of the struts, and through the casing for carrying electrical current therethrough.

  19. Power scaling of semiconductor laser pumped Praseodymium-lasers

    NASA Astrophysics Data System (ADS)

    Richter, A.; Heumann, E.; Huber, G.; Ostroumov, V.; Seelert, W.

    2007-04-01

    We report on efficient lasing of Pr-doped fluoride materials with cw output powers up to 600 mW in the visible spectral range. Praseodymium doped LiYF4 and LiLuF4 crystals were pumped either by an intracavity frequency doubled optically pumped semiconductor laser with output powers up to 1.6 W and nearly diffraction limited beam quality or by a multimode GaN-laser diode with an output power of about 370 mW. Furthermore, intracavity frequency doubling of the red Pr-laser radiation to 320 nm reaching output powers of more than 360 mW with a conversion efficiency of 61% and an optical-to-optical efficiency of 22% are presented.

  20. Coolidge solar powered irrigation pumping project

    NASA Technical Reports Server (NTRS)

    Larson, D. L.

    1980-01-01

    A 150 kW solar thermal electric power plant which includes over 2100 square meters of parabolic trough type collectors and an organic Rankine cycle turbine engine was constructed on an irrigated farm. The plant is interconnected with the electrical utility grid. Operation is providing an evaluation of equipment performance and operating and maintenance requirements as well as the desirability of an on farm location.

  1. High power diode lasers for solid-state laser pumps

    NASA Astrophysics Data System (ADS)

    Linden, Kurt J.; McDonnell, Patrick N.

    1994-02-01

    The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.

  2. High power diode lasers for solid-state laser pumps

    NASA Technical Reports Server (NTRS)

    Linden, Kurt J.; Mcdonnell, Patrick N.

    1994-01-01

    The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.

  3. Solar-powered Rankine heat pump for heating and cooling

    NASA Technical Reports Server (NTRS)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  4. High average power diode pumped solid state lasers for CALIOPE

    SciTech Connect

    Comaskey, B.; Halpin, J.; Moran, B.

    1994-07-01

    Diode pumping of solid state media offers the opportunity for very low maintenance, high efficiency, and compact laser systems. For remote sensing, such lasers may be used to pump tunable non-linear sources, or if tunable themselves, act directly or through harmonic crystals as the probe. The needs of long range remote sensing missions require laser performance in the several watts to kilowatts range. At these power performance levels, more advanced thermal management technologies are required for the diode pumps. The solid state laser design must now address a variety of issues arising from the thermal loads, including fracture limits, induced lensing and aberrations, induced birefringence, and laser cavity optical component performance degradation with average power loading. In order to highlight the design trade-offs involved in addressing the above issues, a variety of existing average power laser systems are briefly described. Included are two systems based on Spectra Diode Laboratory`s water impingement cooled diode packages: a two times diffraction limited, 200 watt average power, 200 Hz multi-rod laser/amplifier by Fibertek, and TRW`s 100 watt, 100 Hz, phase conjugated amplifier. The authors also present two laser systems built at Lawrence Livermore National Laboratory (LLNL) based on their more aggressive diode bar cooling package, which uses microchannel cooler technology capable of 100% duty factor operation. They then present the design of LLNL`s first generation OPO pump laser for remote sensing. This system is specified to run at 100 Hz, 20 nsec pulses each with 300 mJ, less than two times diffraction limited, and with a stable single longitudinal mode. The performance of the first testbed version will be presented. The authors conclude with directions their group is pursuing to advance average power lasers. This includes average power electro-optics, low heat load lasing media, and heat capacity lasers.

  5. Power-scaling of diode-end-pumped solid-state lasers

    NASA Astrophysics Data System (ADS)

    Hardman, Paul Joseph

    1999-11-01

    This thesis presents a strategy for power-scaling diode- end-pumped solid-state lasers to multiwatt output power whilst retaining the high-efficiency and diffraction- limited beam quality, that have been characteristic of operation at low powers. This strategy reduces the detrimental effect of energy-transfer upconversion (ETU), which can decrease the lifetime of the upper-laser-level and also increase the heat generated inside the laser material. An analytical description of the lifetime quenching and increased thermal lensing due to ETU is presented. Using this analytical model it is shown that ETU can be reduced by decreasing the absorption coefficient, by increasing the spot size or by decreasing the upconversion parameter, W. This strategy is applied to a Nd:YLF laser. Before designing the laser the published value of the upconversion parameter for Nd:YLF is confirmed as W = (1.7 +/- 1) × 10-16cm3s -1, by observing the fluorescence saturation with increasing pump power. Also, without applying the power-scaling strategy, the thermal lensing in Nd:YLF in a typical pump set-up is determined, under lasing and non-lasing conditions. A significant difference between the thermal lensing under non-lasing and lasing conditions is observed which is attributed to the increase in heat input caused by ETU. In a standing-wave cavity, under cw lasing conditions and at the maximum pump power (29.5 W incident, 27.4 W absorbed) an output power of 11.1 W is obtained. This laser has excellent beam quality (M2x,y < 1.1) throughout the pump power range. An intracavity-frequency doubled ring laser is also demonstrated. This laser produces >10W of single-frequency output with a 10% output coupler (~9.7 W at 1.053 μm and ~0.6 W at 526.5 nm) at the maximum pump power. With a high reflector, for 1.053 μm, 6.2 W of polarised output (8.3 W generated inside the LBO), at 526.5nm is obtained. This output has excellent beam quality (M2x,y < 1.2) and amplitude stability (<+/-0.5%). The mode

  6. Absorbed dose rate in air in metropolitan Tokyo before the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Inoue, K; Hosoda, M; Fukushi, M; Furukawa, M; Tokonami, S

    2015-11-01

    The monitoring of absorbed dose rate in air has been carried out continually at various locations in metropolitan Tokyo after the accident of the Fukushima Daiichi Nuclear Power Plant. While the data obtained before the accident are needed to more accurately assess the effects of radionuclide contamination from the accident, detailed data for metropolitan Tokyo obtained before the accident have not been reported. A car-borne survey of the absorbed dose rate in air in metropolitan Tokyo was carried out during August to September 2003. The average absorbed dose rate in air in metropolitan Tokyo was 49±6 nGy h(-1). The absorbed dose rate in air in western Tokyo was higher compared with that in central Tokyo. Here, if the absorbed dose rate indoors in Tokyo is equivalent to that outdoors, the annual effective dose would be calculated as 0.32 mSv y(-1). PMID:25944962

  7. High Power 938nm Cladding Pumped Fiber Laser

    SciTech Connect

    Dawson, J; Beach, R; Brobshoff, A; Liao, Z; Payne, S; Pennington, D; Taylor, L; Hackenberg, W; Bonaccini, D

    2002-12-26

    We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous emission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results.

  8. High-power high-efficiency acousto-optically Q-switched rod Nd:YAG laser with 885 nm diode laser pumping

    NASA Astrophysics Data System (ADS)

    Liu, K.; Li, F. Q.; Xu, H. Y.; Wang, Z. C.; Zong, N.; Du, S. F.; Bo, Y.; Peng, Q. J.; Cui, D. F.; Xu, Z. Y.

    2013-01-01

    We have demonstrated a compact Q-switched Nd:YAG laser at 1064 nm with 885 nm diode-laser (LD) direct pumping. At a repetition rate of 100 kHz, an average output power of 53 W with beam quality factor M2 of 1.6 was achieved under the absorbed pump power of 122 W, corresponding to an optical-optical efficiency of 43.5% and a slope efficiency of 57.6%, respectively. The pulse width and the peak power at this output power were 112 ns and 4.74 kW, respectively.

  9. Improving the Energy Efficiency of Pumped-Storage Power Plants

    SciTech Connect

    Artyukh, S. F.; Galat, V. V.; Kuz’min, V. V.; Chervonenko, I. I.; Shakaryan, Yu. G.; Sokur, P. V.

    2015-01-15

    Possible ways to improve the energy efficiency of hydroelectric generating sets of pumped-storage power plants (PSPPs) are studied. The Kiev PSPP is used as an example to show how its generating sets can be upgraded. It is concluded based on studies conducted that synchronous motor-generators should be replaced with asynchronized motor-generators. The feasibility of changing over the turbine to variable-speed operation is shown.

  10. Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation: SIMPLE.

    PubMed

    Kokalj, Tadej; Park, Younggeun; Vencelj, Matjaž; Jenko, Monika; Lee, Luke P

    2014-11-21

    Reliable, autonomous, internally self-powered microfluidic pumps are in critical demand for rapid point-of-care (POC) devices, integrated molecular-diagnostic platforms, and drug delivery systems. Here we report on a Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation (SIMPLE), which is disposable, autonomous, easy to use and fabricate, robust, and cost efficient, as a solution for self-powered microfluidic POC devices. The imbibition pump introduces the working liquid which is sucked into a porous material (paper) upon activation. The suction of the working liquid creates a reduced pressure in the analytical channel and induces the sequential sample flow into the microfluidic circuits. It requires no external power or control and can be simply activated by a fingertip press. The flow rate can be programmed by defining the shape of utilized porous material: by using three different paper shapes with circular section angles 20°, 40° and 60°, three different volume flow rates of 0.07 μL s(-1), 0.12 μL s(-1) and 0.17 μL s(-1) are demonstrated at 200 μm × 600 μm channel cross-section. We established the SIMPLE pumping of 17 μL of sample; however, the sample volume can be increased to several hundreds of μL. To demonstrate the design, fabrication, and characterization of SIMPLE, we used a simple, robust and cheap foil-laminating fabrication technique. The SIMPLE can be integrated into hydrophilic or hydrophobic materials-based microfluidic POC devices. Since it is also applicable to large-scale manufacturing processes, we anticipate that a new chapter of a cost effective, disposable, autonomous POC diagnostic chip is addressed with this technical innovation. PMID:25231831

  11. Performance of passive Q-switched solar-pumped high-power Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Noter, Yoram; Naftali, Nir; Pe'er, Idit L.; Yogev, Amnon; Lando, Mordechai; Shimony, Yehoshua

    1997-09-01

    Q-switched, solar-pumped, high power Nd:YAG lasers are attractive for a variety of applications requiring high instantaneous peak power density. The Q-switching can be obtained by an acousto-optic, electro-optic or passive device. Passive Q-switching seems an excellent choice for space as well as for other applications since it neither requires an external driver nor an electrical power supply. In recent years Cr+4:YAG single crystals were extensively used as passive Q-switches for flashlamp-pumped high power Nd:YAG lasers, demonstrating their superior thermal superior thermal characteristics and durability. In this work we report the first operation of passive Q- switched, solar-pumped, high power Nd:YAG lasers. The concentrated solar energy for he optical pumping of the laser was obtained by a 3-stage combination of imaging and non-imaging optics. It included: i) Weizmann Institute solar tower heliostats, ii) 3D compound parabolic concentrator, and iii) 2D compound parabolic concentrator in which the laser rod was placed. 72 mm long laser rods with either 3 mm or 4 mm diameter were used. The passive Q-switch was made from a Cr$=+4):YAG single crystal having a low- intensity transmission of 72 percent at 1.06 (mu) . Its rear surface was coated by a high reflectivity coating, serving as the rear mirror of the cavity. Output coupling mirrors with various reflectivities were used. The passive Q-switch demonstrated excellent durability and reliability during all the experiments. Repetition rates of 6-39 kHz were measured, showing higher repetition rates at higher laser power levels. The pulses demonstrated shorter full width at half maximum (FWHM) time for higher laser power elves, and the FWHM time range was 190-310 nsec. The maximal measured average power was 14 W. Thermal lensing was measured as a function of the absorbed solar power in the laser rod. It is estimated that laser peak power densities of approximately 100 kW/cm2 were achieved in the experiments. It is

  12. Experimental verification of reconstructed absorbers embedded in scattering media by optical power ratio distribution.

    PubMed

    Yamaoki, Toshihiko; Hamada, Hiroaki; Matoba, Osamu

    2016-09-01

    Experimental investigation to show the effectiveness of the extraction method of absorber information in a scattering medium by taking the output power ratio distribution is presented. In the experiment, two metallic wires sandwiched by three homogeneous scattering media are used as absorbers in transmission geometry. The output power ratio distributions can extract the influence of the absorbers to enhance the optical signal. The peak position of the output power ratio distributions agree with the results suggested by numerical simulation. From the reconstructed results of tomography in the scattering media, we have confirmed that the tomographic image of two wires can distinguish them successfully from 41×21 output power ratio distributions by using continuous-wave light. PMID:27607261

  13. A fermentation-powered thermopneumatic pump for biomedical applications.

    PubMed

    Ochoa, Manuel; Ziaie, Babak

    2012-10-21

    We present a microorganism-powered thermopneumatic pump that utilizes temperature-dependent slow-kinetics gas (carbon dioxide) generating fermentation of yeast as a pressure source. The pump consists of stacked layers of polydimethylsiloxane (PDMS) and a silicon substrate that form a drug reservoir, and a yeast-solution-filled working chamber. The pump operates by the displacement of a drug due to the generation of gas produced via yeast fermentation carried out at skin temperatures. The robustness of yeast allows for long shelf life under extreme environmental conditions (50 °C, >250 MPa, 5-8% humidity). The generation of carbon dioxide is a linear function of time for a given temperature, thus allowing for a controlled volume displacement. A polymeric prototype (dimensions 15 mm × 15 mm × 10 mm) with a slow flow rate of <0.23 μL min(-1) and maximum backpressure of 5.86 kPa capable of continuously pumping for over two hours is presented and characterized. PMID:22918390

  14. A micro-spherical heart pump powered by cultured cardiomyocytes.

    PubMed

    Tanaka, Yo; Sato, Kae; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo; Kitamori, Takehiko

    2007-02-01

    Miniaturization of chemical or biochemical systems creates extremely efficient devices exploiting the advantages of microspaces. Although they are often targeted for implanted tissue engineered organs or drug-delivery devices because of their highly integrated systems, microfluidic devices are usually powered by external energy sources and therefore difficult to be used in vivo. A microfluidic device powered without the need for external energy sources or stimuli is needed. Previously, we demonstrated the concept of a cardiomyocyte pump using only chemical energy input to cells as a driver (Yo Tanaka, Keisuke Morishima, Tatsuya Shimizu, Akihiko Kikuchi, Masayuki Yamato, Teruo Okano and Takehiko Kitamori, Lab Chip, 6(3), pp. 362-368). However, the structure of this prototype pump described there included complicated mechanical components and fabricated compartments. Here, we have created a micro-spherical heart-like pump powered by spontaneously contracting cardiomyocyte sheets driven without a need for external energy sources or coupled stimuli. This device was fabricated by wrapping a beating cardiomyocyte sheet exhibiting large contractile forces around a fabricated hollow elastomeric sphere (5 mm diameter, 250 microm polymer thickness) fixed with inlet and outlet ports. Fluid oscillations in a capillary connected to the hollow sphere induced by the synchronously pulsating cardiomyocyte sheet were confirmed, and the device continually worked for at least 5 days in this system. This bio/artificial hybrid fluidic pump device is innovative not only because it is driven by cells using only chemical energy input, but also because the design is an optimum structure (sphere). We anticipate that this device might be applied for various purposes including a bio-actuator for medical implant devices that relies on biochemical energy, not electrical interfacing. PMID:17268623

  15. Solar Pumped High Power Solid State Laser for Space Applications

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

    2004-01-01

    Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

  16. Thermal characteristics of an end-pumped high-power ytterbium-sensitized erbium-doped fiber laser under natural convection.

    PubMed

    Jeong, Y; Baek, S; Dupriez, P; Maran, J-N; Sahu, J K; Nilsson, J; Lee, B

    2008-11-24

    We investigate the thermal characteristics of a polymer-clad fiber laser under natural convection when it is strongly pumped up to the damage point of the fiber. For this, we utilize a temperature sensing technique based on a fiber Bragg grating sensor array. We have measured the longitudinal temperature distribution of a 2.4-m length ytterbium-sensitized erbium-doped fiber laser that was end-pumped at approximately 975 nm. The measured temperature distribution decreases exponentially, approximately, decaying away from the pump-launch end. We attribute this to the heat dissipation of absorbed pump power. The maximum temperature difference between the fiber ends was approximately 190 K at the maximum pump power of 60.8 W. From this, we estimate that the core temperature reached approximately 236 degrees C. PMID:19030073

  17. Technical advancements in submersible pump power cable for harsh environments

    SciTech Connect

    Guzy, R.; Vandevier, J.

    1985-01-01

    In artificial lift systems, such as electrical submersible pumping, the power cable provides the link between the surface equipment and the pumping unit. New cable designs are constantly being introduced. This article discusses these designs and their materials. Information on a new approach to cable manufacturing and use of downhole materials in harsh environments is also provided. This paper includes work on cable designs which incorporate a new, unique, elastomeric composition that resists rupture of jacketing materials used on downhole cables, eliminating the need for tape and braid. Cable history is also reviewed, classifying the cables by use temperatures and relative cost. The criteria for selecting materials suitable for the entire range of downhole environments is included.

  18. Effects of coolant temperature and pump power on the power output of solar-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Thompson, George A.; Yogev, Amnon; Reich, A.; Oron, Moshe

    1992-11-01

    The temperature dependence of solar-pumped solid state lasers of Nd:YAG and two types of Nd:Cr:GSGG was studied over the temperature range of +30 to -60 C in a quasi-CW mode. All lasers had higher output powers at -40 C. The Nd:Cr:GSGG laser with a chromium concentration of 2.5 at. pct produced 70 W of power at -40 C, quasi-CW. If extrapolated to true CW operation this is equivalent to 350 W. The temperature dependence of the laser performance is attributed to changes in both the stimulated emission cross section and the resonator configuration.

  19. All-optical Q-switching limiter for high-power gigahertz modelocked diode-pumped solid-state lasers.

    PubMed

    Klenner, Alexander; Keller, Ursula

    2015-04-01

    Passively modelocked diode-pumped solid-state lasers (DPSSLs) with pulse repetition rates in the gigahertz regime suffer from an increased tendency for Q-switching instabilities. Low saturation fluence intracavity saturable absorbers - such as the semiconductor saturable absorber mirrors (SESAMs) - can solve this problem up to a certain average output power limited by the onset of SESAM damage. Here we present a passive stabilization mechanism, an all-optical Q-switching limiter, to reduce the impact of Q-switching instabilities and increase the potential output power of SESAM modelocked lasers in the gigahertz regime. With a proper cavity design a Kerr lens induced negative saturable absorber clamps the maximum fluence on the SESAM and therefore limits the onset of Q-switching instabilities. No critical cavity alignment is required because this Q-switching limiter acts well within the cavity stability regime. Using a proper cavity design, a high-power diode-pumped Yb:CALGO solid-state laser generated sub-100 fs pulses with an average output power of 4.1 W at a pulse repetition rate of 5 GHz. With a pulse duration of 96 fs we can achieve a peak power as high as 7.5 kW directly from the SESAM modelocked laser oscillator without any further external pulse amplification and/or pulse compression. We present a quantitative analysis of this Kerr lens induced Q-switching limiter and its impact on modelocked operation. Our work provides a route to compact high-power multi-gigahertz frequency combs based on SESAM modelocked diode-pumped solid-state lasers without any additional external amplification or pulse compression. PMID:25968691

  20. Diode-pumped gigahertz femtosecond Yb:KGW laser with a peak power of 3.9 kW.

    PubMed

    Pekarek, Selina; Fiebig, Christian; Stumpf, Max Christoph; Oehler, Andreas Ernst Heinz; Paschke, Katrin; Erbert, Götz; Südmeyer, Thomas; Keller, Ursula

    2010-08-01

    We present a diode-pumped Yb:KGW laser with a repetition rate of 1 GHz and a pulse duration of 281 fs at a wavelength of 1041 nm. A high brightness distributed Bragg reflector tapered diode laser is used as a pump source. Stable soliton modelocking is achieved with a semiconductor saturable absorber mirror (SESAM). The obtained average output power is 1.1 W and corresponds to a peak power of 3.9 kW and a pulse energy of 1.1 nJ. With harmonic modelocking we could increase the pulse repetition rate up to 4 GHz with an average power of 900 mW and a pulse duration of 290 fs. This Yb:KGW laser has a high potential for stable frequency comb generation. PMID:20721018

  1. Variable energy, high peak power, passive Q-switching diode end-pumped Yb:LuAG laser

    NASA Astrophysics Data System (ADS)

    Kaskow, M.; Sulc, J.; Jabczynski, J. K.; Jelinkova, H.

    2014-12-01

    A new method to control the pulse energy in a passively Q-switched laser was proposed and experimentally verified for a diode-end-pumped Yb:LuAG laser. By changing the pumping area parameters it was possible to demonstrate generation of a wide range of output energies with a single laser configuration consisting of a gain medium, passive Q-switch and out-coupling mirror. The range of available energies 0.15-0.51 mJ with maximum peak power of 113 kW in simple Q-switching regime by means of a Cr:YAG saturable absorber and a Yb:LuAG gain medium pumped by a 20 W laser diode emitting at 968 nm was demonstrated.

  2. Low-power communication with a photonic heat pump.

    PubMed

    Huang, Duanni; Santhanam, Parthiban; Ram, Rajeev J

    2014-12-15

    An optical communication channel is constructed using a heated thermo-electrically pumped, high efficiency infrared light-emitting diode (LED). In these devices, electro-luminescent cooling is observed, resulting in greater than unity (> 100%) efficiency in converting electrical power to optical power. The average amount of electrical energy required to generate a photon (4.3 meV) is much less than the optical energy in that photon (520 meV). Such a light source can serve as a test-bed for fundamental studies of energy-efficient bosonic communication channels. In this low energy consumption mode, we demonstrate data transmission at 3 kilobits per second (kbps) with only 120 picowatts of input electric power. Although the channel employs a mid-infrared source with limited quantum efficiency, a binary digit can be communicated using 40 femtojoules with a bit error rate of 3 x 10-3. PMID:25607478

  3. Optimizing the pumping configuration for the power scaling of in-band pumped erbium doped fiber amplifiers.

    PubMed

    Lim, Ee-Leong; Alam, Shaif-ul; Richardson, David J

    2012-06-18

    A highly efficient (~80%), high power (18.45 W) in-band, core pumped erbium/ytterbium co-doped fiber laser is demonstrated. To the best of our knowledge, this is the highest reported efficiency from an in-band pumped 1.5 µm fiber laser operating in the tens of watts regime. Using a fitted simulation model, we show that the significantly sub-quantum limit conversion efficiency of in-band pumped erbium doped fiber amplifiers observed experimentally can be explained by concentration quenching. We then numerically study and experimentally validate the optimum pumping configuration for power scaling of in-band, cladding pumped erbium doped fiber amplifiers. Our simulation results indicate that a ~77% power conversion efficiency with high output power should be possible through cladding pumping of current commercially available pure Erbium doped active fibers providing the loss experienced by the cladding guided 1535 nm pump due to the coating absorption can be reduced to an acceptable level by better coating material choice. The power conversion efficiency has the potential to exceed 90% if concentration quenching of erbium ions can be reduced via improvements in fiber design and fabrication. PMID:22714454

  4. Chemistry pumps: a review of chemically powered micropumps.

    PubMed

    Zhou, Chao; Zhang, Hua; Li, Zeheng; Wang, Wei

    2016-05-21

    Lab-on-a-chip devices have over recent years attracted a significant amount of attention in both the academic circle and industry, due to their promise in delivering versatile functionalities with high throughput and low sample amount. Typically, mechanical or electrokinetic micropumps are used in the majority of lab-on-a-chip devices that require powered fluid flow, but the technical challenges and the requirement of external power associated with these pumping devices hinder further development and miniaturization of lab-on-a-chip devices. Self-powered micropumps, especially those powered by chemical reactions, have been recently designed and can potentially address some of these issues. In this review article, we provide a detailed introduction to four types of chemically powered micropumps, with particular focus on their respective structures, operating mechanisms and practical usefulness as well as limitations. We then discuss the various functionalities and controllability demonstrated by these micropumps, ending with a brief discussion of how they can be improved in the future. Due to the absence of external power sources, versatile activation methods and sensitivity to environmental cues, chemically powered micropumps could find potential applications in a wide range of lab-on-a-chip devices. PMID:27102134

  5. High power resonant pumping of Tm-doped fiber amplifiers in core- and cladding-pumped configurations.

    PubMed

    Creeden, Daniel; Johnson, Benjamin R; Rines, Glen A; Setzler, Scott D

    2014-11-17

    We have demonstrated ultra-high efficiency amplification in Tm-doped fiber with both core- and cladding-pumped configurations using a resonant tandem-pumping approach. These Tm-doped fiber amplifiers are pumped in-band with a 1908 nm Tm-doped fiber laser and operate at 1993 nm with >90% slope efficiency. In a core-pumped configuration, we have achieved 92.1% slope efficiency and 88.4% optical efficiency at 41 W output power. In a cladding-pumped configuration, we have achieved 123.1 W of output power with 90.4% optical efficiency and a 91.6% slope efficiency. We believe these are the highest optical efficiencies achieved in a Tm-doped fiber amplifier operating in the 2-micron spectral region. PMID:25402145

  6. Power absorbed during whole-body fore-and-aft vibration: Effects of sitting posture, backrest, and footrest

    NASA Astrophysics Data System (ADS)

    Nawayseh, Naser; Griffin, Michael J.

    2012-01-01

    Although the discomfort or injury associated with whole-body vibration cannot be predicted directly from the power absorbed during exposure to vibration, the absorbed power may contribute to understanding of the biodynamics involved in such responses. From measurements of force and acceleration at the seat, the feet, and the backrest, the power absorbed at these three locations was calculated for subjects sitting in four postures (feet hanging, maximum thigh contact, average thigh contact, and minimum thigh contact) both with and without a rigid vertical backrest while exposed to four magnitudes (0.125, 0.25, 0.625, and 1.25 m s -2 rms) of random fore-and-aft vibration. The power absorbed by the body at the supporting seat surface when there was no backrest showed a peak around 1 Hz and another peak between 3 and 4 Hz. Supporting the back with the backrest decreased the power absorbed at the seat at low frequencies but increased the power absorbed at high frequencies. Foot support influenced both the magnitude and the frequency of the peaks in the absorbed power spectra as well as the total absorbed power. The measurements of absorbed power are consistent with backrests being beneficial during exposure to low frequency fore-and-aft vibration but detrimental with high frequency fore-and-aft vibration.

  7. Method and device for remotely monitoring an area using a low peak power optical pump

    DOEpatents

    Woodruff, Steven D.; Mcintyre, Dustin L.; Jain, Jinesh C.

    2014-07-22

    A method and device for remotely monitoring an area using a low peak power optical pump comprising one or more pumping sources, one or more lasers; and an optical response analyzer. Each pumping source creates a pumping energy. The lasers each comprise a high reflectivity mirror, a laser media, an output coupler, and an output lens. Each laser media is made of a material that emits a lasing power when exposed to pumping energy. Each laser media is optically connected to and positioned between a corresponding high reflectivity mirror and output coupler along a pumping axis. Each output coupler is optically connected to a corresponding output lens along the pumping axis. The high reflectivity mirror of each laser is optically connected to an optical pumping source from the one or more optical pumping sources via an optical connection comprising one or more first optical fibers.

  8. Laser performance and thermal lensing in high-power diode-pumped Yb:KGW with athermal orientation

    NASA Astrophysics Data System (ADS)

    Hellström, J. E.; Bjurshagen, S.; Pasiskevicius, V.

    2006-04-01

    A comparative, experimental study of the high-power diode-pumped laser performance and thermal lensing properties between standard b-cut Yb:KGW and Yb:KGW cut along an athermal direction is presented. The results show that thermal lens properties in both the b-cut and the athermal direction-cut crystals are determined by anisotropic thermal expansion in Yb:KGW. Thermal gradients due to the pump beam cause thermal lensing even in the athermal direction-cut geometry. The thermal lens is much weaker and less astigmatic in the athermal direction-cut crystal, for the same absorbed power. These properties allow generation of better-quality laser beams with the athermal direction-cut crystal as compared to the b-cut crystal.

  9. Large-energy, narrow-bandwidth laser pulse at 1645 nm in a diode-pumped Er:YAG solid-state laser passively Q-switched by a monolayer graphene saturable absorber.

    PubMed

    Zhou, Rong; Tang, Pinghua; Chen, Yu; Chen, Shuqing; Zhao, Chujun; Zhang, Han; Wen, Shuangchun

    2014-01-10

    Nonlinear transmission parameters of monolayer graphene at 1645 nm were obtained. Based on the monolayer graphene saturable absorber, a 1532 nm LD pumped 1645 nm passively Q-switched Er:YAG laser was demonstrated. Under the pump power of 20.8 W, a 1645 nm Q-switched pulse with FWHM of 0.13 nm (without the use of etalon) and energy of 13.5 μJ per pulse can be obtained. To the best of our knowledge, this is the highest pulse energy for graphene-based passively Q-switched Er:YAG laseroperating at 1645 nm, suggesting the potentials of graphene materials for high-energy solid-state laser applications. PMID:24514058

  10. Induction generator-induction motor wind-powered pumping system

    SciTech Connect

    Miranda, M.S.; Lyra, R.O.C.; Silva, S.R.

    1997-12-31

    The energy storage matter plays an important role in wind-electric conversion systems for isolated applications. Having that in mind, two different approaches can be basically considered: either the immediate conversion of the generated electric energy, as in a water pumping system or electric energy storage for later use, as in a battery charging system. Due to some features such as no need of an external reactive power source and, sometimes, a gearbox, permanent-magnet synchronous generators have been broadly used in low rated power isolated systems. Despite that, system performance can be affected when the generator is feeding an inductive load (e.g., an induction motor) under variable-speed-variable-frequency operational conditions. Since there is no effective flux control, motor overload may occur at high wind speeds. Thus, good system performance can be obtained through additional control devices which may increase system cost. Although being rugged and cheap, induction machines always work as a reactive power drain; therefore, they demand an external reactive power source. Considering that, reactive static compensators appear as an attractive alternative to the cost x performance problem. In addition to that, different control strategies can be used so that system performance can be improved.

  11. Pumped storage for hydroelectric power. (Latest citations from Fluidex data base). Published Search

    SciTech Connect

    Not Available

    1992-09-01

    The bibliography contains citations concerning the design, development, construction, and characteristics of surface and underground pumped storage for hydroelectric power. Pumped storage projects and facilities worldwide are referenced. There is some consideration of research and experimental results of pumped storage studies, as well as modeling. (Contains a minimum of 192 citations and includes a subject term index and title list.)

  12. Pumped storage for hydroelectric power. (Latest citations from Fluidex (Fluid Engineering Abstracts) database). Published Search

    SciTech Connect

    Not Available

    1993-10-01

    The bibliography contains citations concerning the design, development, construction, and characteristics of surface and underground pumped storage for hydroelectric power. Pumped storage projects and facilities worldwide are referenced. There is some consideration of research and experimental results of pumped storage studies, as well as modeling. (Contains a minimum of 198 citations and includes a subject term index and title list.)

  13. Carbon dioxide absorber and regeneration assemblies useful for power plant flue gas

    DOEpatents

    Vimalchand, Pannalal; Liu, Guohai; Peng, Wan Wang

    2012-11-06

    Disclosed are apparatus and method to treat large amounts of flue gas from a pulverized coal combustion power plant. The flue gas is contacted with solid sorbents to selectively absorb CO.sub.2, which is then released as a nearly pure CO.sub.2 gas stream upon regeneration at higher temperature. The method is capable of handling the necessary sorbent circulation rates of tens of millions of lbs/hr to separate CO.sub.2 from a power plant's flue gas stream. Because pressurizing large amounts of flue gas is cost prohibitive, the method of this invention minimizes the overall pressure drop in the absorption section to less than 25 inches of water column. The internal circulation of sorbent within the absorber assembly in the proposed method not only minimizes temperature increases in the absorber to less than 25.degree. F., but also increases the CO.sub.2 concentration in the sorbent to near saturation levels. Saturating the sorbent with CO.sub.2 in the absorber section minimizes the heat energy needed for sorbent regeneration. The commercial embodiments of the proposed method can be optimized for sorbents with slower or faster absorption kinetics, low or high heat release rates, low or high saturation capacities and slower or faster regeneration kinetics.

  14. Cr,Nd:Gd3Sc2Ga3O12 laser pumped by high-power visible laser diodes

    NASA Astrophysics Data System (ADS)

    Scheps, Richard

    1992-06-01

    Visible laser diodes are used to pump a co-doped Cr,Nd:Gd3Sc2Ga3O12 (Cr,Nd:GSGG) laser rod, demonstrating efficient operation at 1.06 (mu) . Using a 10 cm ROC HR output coupler, the absorbed power required to reach threshold was 938 (mu) W. The round trip losses in the 5 mm long rod were measured to be 4 X 10-3. The best slope efficiency was 42.1%, obtained with a 97% R output coupler. The photon slope efficiency was 66.8%.

  15. High-power Yb:YAG/YAG microchip laser using octagonal-shape waveguide with uniform absorbed power distribution

    NASA Astrophysics Data System (ADS)

    Radmard, S.; Haghparast, A.; Arabgari, S.; Mehrabani, M. T.

    2013-06-01

    An innovative architecture for edge-pumped high power microchip laser is introduced. This geometry consists of a Yb:YAG thin disk gain media surrounded by an irregular octagonal undoped YAG cap as pumping light waveguide. The main advantages of the new geometry are high uniform absorption distribution, high absorption efficiency and simple construction to fabricate. Using the Monte Carlo ray tracing method, the pumping process and absorption profile in active medium are simulated. In addition, considering the impact of Yb+3 doping concentration and temperature on thermal conductivity, and based on the finite-difference method the conduction equation was solved and the temperature distribution in the gain media calculated. Based on these simulations, influence of active medium parameters such as core diameter, doping concentration and octagon side sizes ratio on absorption profile and efficiency as well as maximum temperature in gain medium is investigated. High absorption efficiency (over 94%) with perfect top-hat absorption profile has been predicted to be obtained from the designed microchip with optimized parameters. This microchip has a core diameter of 4 or 5 mm, 9 at% Yb3+ doping concentration and 300 μm thickness. An estimation based on laser rate equations shows that with 960 W pumping power, more than 600 W output power (optical efficiency of 66%) can be extracted from the designed system.

  16. German/Indian cooperation program for solar powered water pumps, phase 1

    NASA Astrophysics Data System (ADS)

    Mukherjee, T. K.; Santhanam, V. C.; Ahmed, S. B.; Schneller, D.; Speidel, K.

    1983-08-01

    A solar powered pump for pumping water from deep wells (up to 100 m) is described. The operating principle corresponds to a Rankine cycle, where solar energy generates vapor for a steam engine driving the water pump. About 900 trouble free working hours were achieved under realistic test conditions with solar energy. Test results indicate a daily pumping rate of 20 to 45 cum/day depending an solar radiation intensity with a collector panel of 28 sqm.

  17. Characterization of a water pump for drum-type washing machine by vibration power approach

    NASA Astrophysics Data System (ADS)

    Heo, YongHwa; Kim, Kwang-joon

    2015-03-01

    Water pumps used in drum-type washing machines to save water are likely to make the washing process noisier than the one without those because the water pumps attached usually onto cabinet structure work as additional vibration and noise sources. In order to either counteract such vibration and noise problems by stiffness design of the cabinet structure or classify the water pumps from the view point of an acceptance test, characterization of the water pumps as excitation sources would be essential. In this paper, several methods to characterize a water pump as an excitation source are investigated. Measurements by traditional methods of blocked force and/or free velocity for a water pump of 35 W are presented. Two methods of vibration power suggested rather recently are reviewed. Then, another method of the vibration power is proposed. Estimations of the vibration power for the water pump operating on a beam structure are obtained and discussed comparatively.

  18. Aging management guideline for commercial nuclear power plants-pumps

    SciTech Connect

    Booker, S.; Katz, D.; Daavettila, N.; Lehnert, D.

    1994-03-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant pumps important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  19. Thermal optimization of second harmonic generation at high pump powers.

    PubMed

    Sahm, Alexander; Uebernickel, Mirko; Paschke, Katrin; Erbert, Götz; Tränkle, Günther

    2011-11-01

    We measure the temperature distribution of a 3 cm long periodically poled LiNbO₃ crystal in a single-pass second harmonic generation (SHG) setup at 488 nm. By means of three resistance heaters and directly mounted Pt100 sensors the crystal is subdivided in three sections. 9.4 W infrared pump light and 1.3 W of SHG light cause a de-homogenized temperature distribution of 0.2 K between the middle and back section. A sectional offset heating is used to homogenize the temperature in those two sections and thus increasing the conversion efficiency. A 15% higher SHG output power matching the prediction of our theoretical model is achieved. PMID:22109182

  20. Low-power microfluidic electro-hydraulic pump (EHP).

    PubMed

    Lui, Clarissa; Stelick, Scott; Cady, Nathaniel; Batt, Carl

    2010-01-01

    Low-power electrolysis-based microfluidic pumps utilizing the principle of hydraulics, integrated with microfluidic channels in polydimethylsiloxane (PDMS) substrates, are presented. The electro-hydraulic pumps (EHPs), consisting of electrolytic, hydraulic and fluidic chambers, were investigated using two types of electrodes: stainless steel for larger volumes and annealed gold electrodes for smaller-scale devices. Using a hydraulic fluid chamber and a thin flexible PDMS membrane, this novel prototype successfully separates the reagent fluid from the electrolytic fluid, which is particularly important for biological and chemical applications. The hydraulic advantage of the EHP device arises from the precise control of flow rate by changing the electrolytic pressure generated, independent of the volume of the reagent chamber, mimicking the function of a hydraulic press. Since the reservoirs are pre-filled with reagents and sealed prior to testing, external fluid coupling is minimized. The stainless steel electrode EHPs were manufactured with varying chamber volume ratios (1 : 1 to 1 : 3) as a proof-of-concept, and exhibited flow rates of 1.25 to 30 microl/min with electrolysis-based actuation at 2.5 to 10 V(DC). The miniaturized gold electrode EHPs were manufactured with 3 mm diameters and 1 : 1 chamber volume ratios, and produced flow rates of 1.24 to 7.00 microl/min at 2.5 to 10 V(AC), with a higher maximum sustained pressure of 343 KPa, suggesting greater device robustness using methods compatible with microfabrication. The proposed technology is low-cost, low-power and disposable, with a high level of reproducibility, allowing for ease of fabrication and integration into existing microfluidic lab-on-a-chip and analysis systems. PMID:20024053

  1. Generalized formula for continuous-wave end-pumped Yb-doped material amplifier gain and laser output power in various pumping configurations.

    PubMed

    Bourdet, Gilbert L; Bartnicki, Eric

    2006-12-20

    We present a general formula fitted for computing the amplification and laser output power in a Yb-doped material under various quasi-end-pumping configurations. These configurations include single pass pumping, backreflection pumping in which the pump is reflected by a mirror set on the rear face of the amplifier medium, contrapropagation pumping where two pump beams are launched on both sides of the amplifier and, for every configuration, regenerative pumping in which the transmitted or reflected pump beam is recycled using the proper apparatus. We show that, with regenerative pumping, the efficiency is drastically improved and the optimum amplifier length leading to the maximum laser output power is shorter compared with the one obtained with conventional pumping. In this model, we do not take temperature effect into account. PMID:17151761

  2. High-average-power diode-pumped Yb: YAG lasers

    SciTech Connect

    Avizonis, P V; Beach, R; Bibeau, C M; Emanuel, M A; Harris, D G; Honea, E C; Monroe, R S; Payne, S A; Skidmore, J A; Sutton, S B

    1999-10-01

    A scaleable diode end-pumping technology for high-average-power slab and rod lasers has been under development for the past several years at Lawrence Livermore National Laboratory (LLNL). This technology has particular application to high average power Yb:YAG lasers that utilize a rod configured gain element. Previously, this rod configured approach has achieved average output powers in a single 5 cm long by 2 mm diameter Yb:YAG rod of 430 W cw and 280 W q-switched. High beam quality (M{sup 2} = 2.4) q-switched operation has also been demonstrated at over 180 W of average output power. More recently, using a dual rod configuration consisting of two, 5 cm long by 2 mm diameter laser rods with birefringence compensation, we have achieved 1080 W of cw output with an M{sup 2} value of 13.5 at an optical-to-optical conversion efficiency of 27.5%. With the same dual rod laser operated in a q-switched mode, we have also demonstrated 532 W of average power with an M{sup 2} < 2.5 at 17% optical-to-optical conversion efficiency. These q-switched results were obtained at a 10 kHz repetition rate and resulted in 77 nsec pulse durations. These improved levels of operational performance have been achieved as a result of technology advancements made in several areas that will be covered in this manuscript. These enhancements to our architecture include: (1) Hollow lens ducts that enable the use of advanced cavity architectures permitting birefringence compensation and the ability to run in large aperture-filling near-diffraction-limited modes. (2) Compound laser rods with flanged-nonabsorbing-endcaps fabricated by diffusion bonding. (3) Techniques for suppressing amplified spontaneous emission (ASE) and parasitics in the polished barrel rods.

  3. Study of hybrid power system potential to power agricultural water pump in mountain area

    NASA Astrophysics Data System (ADS)

    Syuhada, Ahmad; Mubarak, Amir Zaki; Maulana, M. Ilham

    2016-03-01

    As industry and Indonesian economy grow fast, there are a lot of agricultural land has changed into housing and industrial land. This causes the agricultural land moves to mountain area. In mountainous agricultural area, farmers use the water resources of small rivers in the groove of the mountain to irrigate the farmland. Farmers use their power to lift up water from the river to their land which causes inefectivity in the work of the farmers. Farmers who have capital utilize pump to raise water to their land. The only way to use pump in mountain area is by using fuel energy as there is no electricity, and the fuel price in mountain area is very expensive. Based on those reasons it is wise to consider the exploration of renewable energy available in the area such as solar energy, wind energy and hybrid energy. This study analyses the potential of the application of hybrid power plant, which is the combination of solar and wind energy, to power agricultural pump. In this research, the data of wind speed and solar radiation are collected from the measurement of BMKG SMPK Plus Sare. Related to the solar energy, the photovoltaic output power calculation is 193 W with duration of irradiation of 5 hours/day. While for the wind energy, the output power of the wind turbine is 459.84 W with blade diameter of 3 m and blow duration of 7 hours/day. The power of the pump is 558 W with 8 hours of usage, and the water capacity is 2.520 liters/hour for farmland with the area of 15 ha. Based on the analysis result, the designed system will generate electricity of 3.210 kW/year with initial investment of US 14,938.

  4. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

    SciTech Connect

    Dubey, P. K. Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-15

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

  5. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target.

    PubMed

    Dubey, P K; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-01

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique. PMID:24880401

  6. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

    NASA Astrophysics Data System (ADS)

    Dubey, P. K.; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-01

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

  7. Thermal Lensing in a High Power Diode-Pumped Continuous Wave Yb+3:KY(WO4)2 Laser

    NASA Astrophysics Data System (ADS)

    Mirzaeian, Hamidreza

    High power diode-pumped solid state (DPSS) lasers are a rapidly growing technology that is attractive for various applications in scientific and industrial fields. DPSS lasers are highly efficient, reliable and durable with superior beam quality when compared to flash-lamp pumped lasers. Double-tungstate crystals such as potassium yttrium tungstate Yb:KY(WO4)2 (Yb:KYW) are one of the most popular active materials used in DPSS lasers for generation of continuous wave radiation and ultrashort (i.e. femtosecond, 10-15 s) pulses with high average output power. The high pump power of laser diodes results in considerable heat generation in a laser crystal that in turn causes thermal lensing effect. Thermal lensing affects the performance and stability of a resonator, and plays an important role in limiting the output power and degrading the beam quality of solid state lasers. Despite these facts, no detailed studies of thermal effects in Yb:KYW lasers were reported to date. In this work thermal lensing in a diode-pumped Ng-cut Yb:KYW laser operating at the wavelength of 1.04 ?m was characterized. A maximum output power of 3.5 W with a nearly diffraction limited output beam (M 2 < 1.2) was achieved under the absorbed pump power of 13.8 W. The focal lengths of the induced thermal lenses were obtained from the laser output beam size measurements at various incident pump power levels and ABCD matrix analysis. At maximum output power the focal length of the induced thermal lens was found to be 814 mm for the Nm direction (horizontal) and 144 mm for the Np direction (vertical). Thermal lens sensitivity factors were 1.26 m-1/W and 0.32 m-1/W for the Np and Nm directions, respectively. This highly astigmatic thermal lensing can be explained by strong anisotropy of thermo-optical properties of the crystal and its cooling geometry. In addition, the finite element analysis (FEA) method was employed to obtain the focal lengths of the induced thermal lens inside the crystal

  8. Pump power stability range of single-mode solid-state lasers with rod thermal lensing

    SciTech Connect

    De Silvestri, S.; La Porta, P.; Magni, V.

    1987-11-01

    The pump power stability range of solid-state laser resonators operating in the TEM/sub 00/ mode has been thoroughly investigated. It has been shown that, for a very general resonator containing intracavity optical systems, rod thermal lensing engenders a pump power stability range which is a characteristic parameter of laser material and pump cavity, but is independent of resonator configuration. Stability ranges have been calculated and critically discussed for Nd:YAG, Nd:Glasses, Nd:Cr:GSGG, and alexandrite. The independence of the pump power stability range from the resonator configuration has been experimentally demonstrated for a CW Nd:YAG laser.

  9. High power eye-safe Er3+:YVO4 laser diode-pumped at 976 nm and emitting at 1603 nm

    NASA Astrophysics Data System (ADS)

    Newburgh, G. A.; Dubinskii, M.

    2016-02-01

    We report on the performance of an eye-safe laser based on a Er:YVO4 single crystal, diode-pumped at 976 nm (4I15/2-->4I11/2 transition) and operating at 1603 nm (4I13/2-->4I15/2 transition) with good beam quality. A 10 mm long Er3+:YVO4 slab, cut with its c-axis perpendicular to the laser cavity axis, was pumped in σ-polarization and lased in π-polarization. The laser operated in a quasi-continuous wave (Q-CW) regime with nearly 9 W output power, and with a slope efficiency of about 39% with respect to absorbed power. This is believed to be the highest efficiency and highest power achieved from an Er3+:YVO4 laser pumped in the 970-980 nm absorption band.

  10. High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber

    PubMed Central

    Chernysheva, Maria; Mou, Chengbo; Arif, Raz; AlAraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

    2016-01-01

    We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a ‘Yin-Yang’ all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser. PMID:27063511

  11. High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber.

    PubMed

    Chernysheva, Maria; Mou, Chengbo; Arif, Raz; AlAraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

    2016-01-01

    We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a 'Yin-Yang' all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser. PMID:27063511

  12. High Power Q-Switched Thulium Doped Fibre Laser using Carbon Nanotube Polymer Composite Saturable Absorber

    NASA Astrophysics Data System (ADS)

    Chernysheva, Maria; Mou, Chengbo; Arif, Raz; Alaraimi, Mohammed; Rümmeli, Mark; Turitsyn, Sergei; Rozhin, Aleksey

    2016-04-01

    We have proposed and demonstrated a Q-switched Thulium doped fibre laser (TDFL) with a ‘Yin-Yang’ all-fibre cavity scheme based on a combination of nonlinear optical loop mirror (NOLM) and nonlinear amplified loop mirror (NALM). Unidirectional lasing operation has been achieved without any intracavity isolator. By using a carbon nanotube polymer composite based saturable absorber (SA), we demonstrated the laser output power of ~197 mW and pulse energy of 1.7 μJ. To the best of our knowledge, this is the highest output power from a nanotube polymer composite SA based Q-switched Thulium doped fibre laser.

  13. Unphysical consequences of negative absorbed power in linear passive scattering: Implications for radiation force and torque.

    PubMed

    Marston, Philip L; Zhang, Likun

    2016-06-01

    Contrary to some claims, the absorbed power associated with linear scattering of sound by passive objects in ideal fluids must be non-negative. Such unphysical claims suggest analytical or computational error, or use of an unphysical constitutive relation for material properties. The close connection with the evaluation of acoustic radiation force on targets according to Westervelt's formulation [J. Acoust. Soc. Am. 29, 26-29 (1957)], recently generalized to certain acoustic beams, is briefly reviewed along with the theory of acoustic radiation torque on axisymmetric targets with power absorption. Applications to viscous dissipation and to issues pertaining to active targets are also examined. PMID:27369138

  14. Powerful 2-μm all-fiber laser sources pumped by Raman fiber lasers

    NASA Astrophysics Data System (ADS)

    Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Jin, Xiaoxi; Wang, Xiaolin; Xiao, Hu; Liu, Zejin

    2014-11-01

    We present novel and powerful pump schemes for fiber laser sources operating near 2 μm, which employing high power Raman fiber lasers (RFLs) to provide sufficient pump light. Firstly, we demonstrate a Tm-doped fiber laser (TDFL) pumped by two RFLs at 1173 nm. The output power of the TDFL reached 96 W with slope efficiency of 0.42, and the central wavelength located at 1943.3 nm. This is the first TDFL with 100 W-level output power pumped by RFLs around Tm3+ ions' ~1200 nm absorption band. Secondly, we demonstrate a Ho-doped fiber laser (HDFL) employing a 1150 nm RFL as pump source. The 1150 nm RFL provided 110 W pump power and the output power of the HDFL reached 42 W with slope efficiency of 0.37. The lasing wavelength covered from 2046.8 nm to 2049.5 nm with optical signal-to-noise ratio more than 30 dB. This is the first HDFL pumped by a 1150 nm RFL and the highest output power achieved at this pump band. In the last, we present a high power Ho-doped fiber (HDF) superfluorescent source (SS) pumped by a 1150 nm RFL. The SS's output power reached 1.5 W, and the full width at half maximum was about 30 nm. This is the highest output power achieved in HDF as far as we know. The results above indicate promising and powerful pump schemes to achieve higher power output in fiber lasers near 2 μm, which also can be further improved by optimizing the parameters of the sources.

  15. Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

    SciTech Connect

    Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

    2010-09-01

    Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

  16. 264 W output power at 1585 nm in Er-Yb codoped fiber laser using in-band pumping.

    PubMed

    Jebali, M A; Maran, J-N; LaRochelle, S

    2014-07-01

    We demonstrate a high-power cladding-pumped Er-Yb codoped fiber laser with 74% efficiency. A pump-limited output power of 264 W is obtained using in-band pumping at 1535 nm. We compare the efficiency of 1480 and 1535 nm pumping through numerical simulations and experimental measurements. PMID:24978785

  17. High power VCSEL array pumped Q-switched Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Xiong, Yihan; Van Leeuwen, Robert; Watkins, Laurence S.; Seurin, Jean-Francois; Xu, Guoyang; Miglo, Alexander; Wang, Qing; Ghosh, Chuni

    2012-03-01

    Solid-state lasers pumped by high-power two-dimensional arrays of vertical-cavity surface-emitting lasers (VCSELs) were investigated. Both end-pumping and side-pumping schemes of Nd:YAG lasers with high power kW-class 808 nm VCSEL pump modules were implemented. For one application 10 mJ blue laser pulses were obtained from a frequencydoubled actively Q-switched VCSEL-array dual side-pumped Nd:YAG laser operating at 946 nm. For another application 10 mJ green laser pulses were obtained from a frequency-doubled passively Q-switched VCSEL-array endpumped Nd:YAG laser operating at 1064 nm. Both QCW and CW pumping schemes were investigated to achieve high average Q-switched power.

  18. Simulations of absorbance efficiency and power production of three dimensional tower arrays for use in photovoltaics

    NASA Astrophysics Data System (ADS)

    Flicker, Jack; Ready, Jud

    2008-06-01

    The production of cheap energy from the sun will be a major research objective in the coming years. Major strides must be made in solar cell efficiency, including increasing absorbance efficiency of a cell by etching or texturing. In order to increase the absorbance efficiency of solar cells, we have developed a three-dimensional solar cell structure by depositing a cadmium telluride thin film overtop carbon nanotube towers. These towers act as both a scaffolding and an electrical interconnect. Multiple photon interactions as they reflect between these towers increase the absorption efficiency. We have developed a theoretical model and computer simulation to maximize the number of photon interactions due to the geometrical characteristics of the system (aspect ratio, spacing, size, shape, etc.). Simulated modeling has shown that by optimization of parameters, a three-dimensional cell can obtain up to a 300% increase in power production over traditional cells.

  19. Liquid Metal Pump Technologies for Nuclear Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2007-01-01

    Multiple liquid metal pump options are reviewed for the purpose of determining the technologies that are best suited for inclusion in a nuclear reactor thermal simulator intended to test prototypical space nuclear system components. Conduction, induction, and thermoelectric electromagnetic pumps are evaluated based on their performance characteristics and the technical issues associated incorporation into a reactor system. The thermoelectric electromagnetic pump is recommended for inclusion in the present system based on favorable quantitative and qualitative measures relative to the other options under consideration.

  20. A 250 MHz, high power mode-locked Nd:GdVO4 oscillator with low timing jitter under 879 nm direct pumping

    NASA Astrophysics Data System (ADS)

    Zhang, F. F.; Zuo, J. W.; Wang, Z. M.; Yang, J.; Cheng, H. L.; Zong, N.; Yang, F.; Peng, Q. J.; Xu, Z. Y.

    2013-04-01

    We developed a high power mode-locked Nd:GdVO4 oscillator with low timing jitter directly pumped by an 879 nm diode. Under the absorbed pump power of 13.8 W, a maximum output power of 5.68 W at 1063 nm was obtained with a repetition rate of ˜250 MHz, corresponding to a slope efficiency of 78.7%. The measured pulse width and root mean square timing jitter at the output power of 5.35 W were 7.4 ps and 286 fs, respectively. To the best of our knowledge, this is the highest output power for a picosecond Nd:GdVO4 oscillator with low timing jitter.

  1. PUMPS

    DOEpatents

    Thornton, J.D.

    1959-03-24

    A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

  2. Experimental Investigation of the Power Generation Performance of Floating-Point Absorber Wave Energy Systems: Preprint

    SciTech Connect

    Li, Y.; Yu, Y.; Epler, J.; Previsic, M.

    2012-04-01

    The extraction of energy from ocean waves has gained interest in recent years. The floating-point absorber (FPA) is one of the most promising devices among a wide variety of wave energy conversion technologies. Early theoretical studies mainly focused on understanding the hydrodynamics of the system and on predicting the maximum power that could be extracted by a heaving body. These studies evolve from the investigation of floating-body interactions in offshore engineering and naval architecture disciplines. To our best knowledge, no systematic study has been reported about the investigation of the power generation performance of an FPA with a close-to-commercial design. A series of experimental tests was conducted to investigate the power extraction performance of an FPA system.

  3. High-power pump combiners for Tm-doped fibre lasers

    NASA Astrophysics Data System (ADS)

    Stachowiak, D.; Kaczmarek, P.; Abramski, K. M.

    2015-12-01

    In this paper our results of investigation on a pump power combiner in a configuration of 7×1 are presented. The performed combiner, with pump power of 80-85% transmission level, was successfully applied in a thulium doped fibre laser. The performed all-fibre laser setup reached a total CW output power of 6.42 W, achieving the efficiency on a 32.1% level.

  4. Demonstration of a high output power 1533nm optical parametric oscillator pumped at 1064nm

    NASA Astrophysics Data System (ADS)

    Foltynowicz, Robert J.; Wojcik, Michael D.

    2010-10-01

    A high output power, eye-safe, LIDAR transmitter based on a KTA optical parametric oscillator (OPO) was demonstrated. The OPO was based on a two crystal, NCPM, KTA ring cavity which was doubly resonant. A 7ns, 30Hz, flashlamp-pumped, Q-switched Nd:YAG laser was injection seeded and used to pump the OPO. The OPO converted the 1064 nm pump beam into a 1533 nm signal wave and 3475 nm idler wave. In addition to demonstrating a high power OPO system, we investigated the effects of seeding the pump laser on the OPO's conversion efficiency, oscillation threshold, maximum signal power, and beam quality. The power conversion efficiency between the signal and the injection seeded pump was 22% with an oscillation threshold of 104 MW/cm2 (500 mJ) and a maximum signal power of 6.44 W (215 mJ). The power conversion efficiency between the signal and the unseeded pump was 24% with an oscillation threshold of 77 MW/cm2 (367mJ) and a maximum signal power of 7 W (233 mJ). The beam quality of the signal beam was produced an M2 =15. When the pump laser was seeded, the full angle divergence improved by nearly a factor of five.

  5. Power consumption of rotary blood pumps: pulsatile versus constant-speed mode.

    PubMed

    Pirbodaghi, Tohid; Cotter, Chris; Bourque, Kevin

    2014-12-01

    We investigated the power consumption of a HeartMate III rotary blood pump based on in vitro experiments performed in a cardiovascular simulator. To create artificial-pulse mode, we modulated the pump speed by decreasing the mean speed by 2000 rpm for 200 ms and then increasing speed by 4000 rpm (mean speeds plus 2000 rpm) for another 200 ms, creating a square waveform shape. The HeartMate III was connected to a cardiovascular simulator consisting of a hydraulic pump system to simulate left ventricle pumping action, arterial and venous compliance chambers, and an adjustable valve for peripheral resistance to facilitate the desired aortic pressure. The simulator operated based on Suga's elastance model to mimic the Starling response of the heart, thereby reproducing physiological blood flow and pressure conditions. We measured the instantaneous total electrical current and voltage of the pump to evaluate its power consumption. The aim was to answer these fundamental questions: (i) How does pump speed modulation affect pump power consumption? (ii) How does the power consumption vary in relation to external pulsatile flow? The results indicate that speed modulation and external pulsatile flow both moderately increase the power consumption. Increasing the pump speed reduces the impact of external pulsatile flow. PMID:24842216

  6. Photoexited switchable metamaterial absorber at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Xu, Zongcheng; Gao, Runmei; Ding, Chunfeng; Wu, Liang; Zhang, Yating; Xu, Degang; Yao, Jianquan

    2015-06-01

    We propose a design and numerical study of an optically switchable metamaterial absorber in the terahertz regime. The metamaterial absorber comprises a periodic array of metallic split-ring resonators sitting back to back with an embedded semiconductor silicon. Filing the gap between the resonator arms with a semiconductor (silicon), leads to easy modification of its optical response through a pump beam which changes conductivity of Si. The conductivity of silicon is a function of incident pump power. Therefore, the resonance frequencies of the metamaterial can be tunable by applying an external pump power. The resonance peak of the absorption spectra shows a shift from 1.17 to 0.68 THz via external optical stimulus, with granting a resonance tuning range on the order of 42%. The optical-tuned absorber has potential applications as a terahertz modulator and switchable device and offer a step forward in filling the "THz gap".

  7. 87  fs pulse generation in a diode-pumped semiconductor saturable absorber mirror mode-locked Yb:YLF laser.

    PubMed

    Pirzio, Federico; Fregnani, Luigi; Volpi, Azzurra; Lieto, Alberto Di; Tonelli, Mauro; Agnesi, Antonio

    2016-06-01

    A Yb:YLF crystal has been investigated in a femtosecond oscillator pumped by two 400 mW single-mode fiber-coupled diodes emitting at 976 nm and mode locked with a semiconductor saturable absorber mirror. Almost Fourier transform-limited pulses with durations of 87 and 107 fs were demonstrated for extraordinary and ordinary polarizations, respectively. This is, to the best of our knowledge, the first demonstration of sub-100 fs pulses with Yb:YLF, and it proves the potential for ultrashort pulse generation and amplification with this material. PMID:27411196

  8. High power high repetition rate VCSEL array side-pumped pulsed blue laser

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Robert; Zhao, Pu; Chen, Tong; Xu, Bing; Watkins, Laurence; Seurin, Jean-Francois; Xu, Guoyang; Miglo, Alexander; Wang, Qing; Ghosh, Chuni

    2013-03-01

    High power, kW-class, 808 nm pump modules based on the vertical-cavity surface-emitting laser (VCSEL) technology were developed for side-pumping of solid-state lasers. Two 1.2 kW VCSEL pump modules were implemented in a dual side-pumped Q-switched Nd:YAG laser operating at 946 nm. The laser output was frequency doubled in a BBO crystal to produce pulsed blue light. With 125 μs pump pulses at a 300 Hz repetition rate 6.1 W QCW 946 nm laser power was produced. The laser power was limited by thermal lensing in the Nd:YAG rod.

  9. High power operation of a flashlamp-pumped Nd:YAG laser at 1123 nm

    NASA Astrophysics Data System (ADS)

    Lee, Hee Chul; Kim, Yong Pyung

    2010-04-01

    A high power flashlamp-pumped Nd:YAG laser at 1123 nm with a repetition rate of 40 Hz is investigated. Simple but specially coated resonator mirrors are adopted to suppress the parasitic oscillation at gain transition lines higher than 1123 nm. A maximum average output power of 40 W with an electrical pumping energy of 45.7 J and pumping pulse duration of 150 μs is achieved. To the best of our knowledge, the output power of 40 W at a wavelength of 1123 nm is the highest record up to now.

  10. The LUCIA project: a high average power ytterbium diode pumped solid state laser chain

    NASA Astrophysics Data System (ADS)

    Bourdet, Gilbert L.; Chanteloup, Jean-Christophe; Fulop, A.; Julien, Y.; Migus, Arnold

    2004-04-01

    With the goal to set up a high average power Diode Pumped Solid State Laser (100 Joules/10 Hz/10 ns), the Laboratory for Use of Intense Laser (LULI) is now studying various solutions concerning the amplifier medium, the cooling, the pumping and the extraction architectures. In this paper, we present the last states of these developments and the solutions already chosen.

  11. Design, manufacture, and test of coolant pump-motor assembly for Brayton power conversion system

    NASA Technical Reports Server (NTRS)

    Gabacz, L. E.

    1973-01-01

    The design, development, fabrication, and testing of seven coolant circulating pump-motor assemblies are discussed. The pump-motor assembly is driven by the nominal 44.4-volt, 400-Hz, 3-phase output of a nominal 56-volt dc input inverter. The pump-motor assembly will be used to circulate Dow Corning 200 liquid coolant for use in a Brayton cycle space power system. The pump-motor assembly develops a nominal head of 70 psi at 3.7 gpm with an over-all efficiency of 26 percent. The design description, drawings, photographs, reliability results, and developmental and acceptance test results are included.

  12. Electric Adsorption Heat Pump for Electric Vehicles: Electric-Powered Adsorption Heat Pump for Electric Vehicles

    SciTech Connect

    2011-11-21

    HEATS Project: PNNL is developing a new class of advanced nanomaterial called an electrical metal organic framework (EMOF) for EV heating and cooling systems. The EMOF would function similar to a conventional heat pump, which circulates heat or cold to the cabin as needed. However, by directly controlling the EMOF's properties with electricity, the PNNL design is expected to use much less energy than traditional heating and cooling systems. The EMOF-based heat pumps would be light, compact, efficient, and run using virtually no moving parts.

  13. Performance Testing of a Prototypic Annular Linear Induction Pump for Fission Surface Power

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.; Pearson, J. B.; Schoenfeld, M. P.; Webster, K.; Houts, M. G.; Godfroy, T. J.; Bossard, J. A.

    2010-01-01

    Results of performance testing of an annular linear induction pump are presented. The pump electromagnetically pumps liquid metal (NaK) through a circuit specially designed to allow for quantification of the performance. Testing was conducted over a range of conditions, including frequencies of 33, 36, 39, and 60 Hz, liquid metal temperatures from 25 to 525 C, and input voltages from 5 to 120 V. Pump performance spanned a range of flow rates from roughly 0.16 to 5.7 L/s (2.5 to 90 gpm), and pressure head <1 to 90 kPa (<0.145 to 13 psi). The maximum efficiency measured during testing was slightly greater than 6%. The efficiency was fairly insensitive to input frequency from 33 to 39 Hz, and was markedly lower at 60 Hz. In addition, the efficiency decreased as the NaK temperature was raised. While the pump was powered, the fluid responded immediately to changes in the input power level, but when power was removed altogether, there was a brief slow-down period before the fluid would come to rest. The performance of the pump operating on a variable frequency drive providing 60 Hz power compared favorably with the same pump operating on 60 Hz power drawn directly from the electrical grid.

  14. High-power diode-pumped mode-locked Yb:YAG ceramic laser

    NASA Astrophysics Data System (ADS)

    Nakamura, Shinki; Hikita, Yuto; Sone, Hiroyasu; Ogawa, Takayo; Wada, Satoshi

    2014-05-01

    A high-power diode-pumped passively mode-locked Yb:YAG ceramic laser was demonstrated. An average output power of 3.80W with a pulse duration of 433 fs at a repetition rate of 90.9MHz was obtained at a wavelength of 1050 nm using a 2% output coupler. A peak power of 96.5kW was also obtained. To the best of our knowledge, these are the highest reported average power and peak power for a diode-pumped mode-locked Yb:YAG ceramic laser.

  15. High-power LD end-pumped Tm:YAG ceramic slab laser

    NASA Astrophysics Data System (ADS)

    Liu, Xuan; Huang, Haitao; Shen, Deyuan; Fan, Xuliang; Yao, Weichao; Zhu, Heyuan; Zhang, Jian; Tang, Dingyuan

    2015-03-01

    A high-power Tm:YAG ceramic slab laser is reported. Deliberate thermal management was made to dissipate the heat effectively and release the stress in ceramics. The influence of pump wavelength on laser performance was investigated. A maximum of 52 W output power was achieved, corresponding to a slope efficiency of 27.8 % with respect to the incident pump power. As to our knowledge, this is the highest 2-μm laser output power reported in Tm:YAG ceramic lasers. This result proves that Tm:YAG laser ceramic is a promising candidate for 2-μm high-power laser applications.

  16. Design of a Mechanical NaK Pump for Fission Space Power

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David E.; Godfroy, Thomas

    2011-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid, which has specific pumping requirements. Traditionally, electromagnetic linear induction pumps have been used to provide the required flow and pressure head conditions for NaK systems but they can be limited in performance, efficiency, and number of available vendors. The objective of the project was to develop a mechanical NaK centrifugal pump that takes advantages of technology advances not available in previous liquid metal mechanical pump designs. This paper details the design, build, and performance test of a mechanical NaK pump developed at NASA Marshall Space Flight Center. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  17. Multiphysics Modeling of an Annular Linear Induction Pump With Applications to Space Nuclear Power Systems

    NASA Technical Reports Server (NTRS)

    Kilbane, J.; Polzin, K. A.

    2014-01-01

    An annular linear induction pump (ALIP) that could be used for circulating liquid-metal coolant in a fission surface power reactor system is modeled in the present work using the computational COMSOL Multiphysics package. The pump is modeled using a two-dimensional, axisymmetric geometry and solved under conditions similar to those used during experimental pump testing. Real, nonlinear, temperature-dependent material properties can be incorporated into the model for both the electrically-conducting working fluid in the pump (NaK-78) and structural components of the pump. The intricate three-phase coil configuration of the pump is implemented in the model to produce an axially-traveling magnetic wave that is qualitatively similar to the measured magnetic wave. The model qualitatively captures the expected feature of a peak in efficiency as a function of flow rate.

  18. Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

    SciTech Connect

    1997-03-01

    The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

  19. High average power parametric frequency conversion-new concepts and new pump sources

    SciTech Connect

    Velsko, S.P.; Webb, M.S.

    1994-03-01

    A number of applications, including long range remote sensing and antisensor technology, require high average power tunable radiation in several distinct spectral regions. Of the many issues which determine the deployability of optical parametric oscillators (OPOS) and related systems, efficiency and simplicity are among the most important. It is only recently that the advent of compact diode laser pumped solid state lasers has produced pump sources for parametric oscillators which can make compact, efficient, high average power tunable sources possible. In this paper we outline several different issues in parametric oscillator and pump laser development which are currently under study at Lawrence Livermore National Laboratory.

  20. High power pumped MID-IR wavelength devices using nonlinear frequency mixing (NFM)

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Lang, Robert J. (Inventor); Waarts, Robert G. (Inventor)

    2001-01-01

    Laser diode pumped mid-IR wavelength sources include at least one high power, near-IR wavelength, injection and/or sources wherein one or both of such sources may be tunable providing a pump wave output beam to a quasi-phase matched (QPM) nonlinear frequency mixing (NFM) device. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Wavelength tuning of at least one of the sources advantageously provides the ability for optimizing pump or injection wavelengths to match the QPM properties of the NFM device enabling a broad range of mid-IR wavelength selectivity. Also, pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.

  1. High power pumped mid-IR wavelength systems using nonlinear frequency mixing (NFM) devices

    NASA Technical Reports Server (NTRS)

    Sanders, Steven (Inventor); Lang, Robert J. (Inventor); Waarts, Robert G. (Inventor)

    1999-01-01

    Laser diode pumped mid-IR wavelength systems include at least one high power, near-IR wavelength, injection and/or sources wherein one or both of such sources may be tunable providing a pump wave output beam to a quasi-phase matched (QPM) nonlinear frequency mixing (NFM) device. The NFM device may be a difference frequency mixing (DFM) device or an optical parametric oscillation (OPO) device. Wavelength tuning of at least one of the sources advantageously provides the ability for optimizing pump or injection wavelengths to match the QPM properties of the NFM device enabling a broad range of mid-IR wavelength selectivity. Also, pump powers are gain enhanced by the addition of a rare earth amplifier or oscillator, or a Raman/Brillouin amplifier or oscillator between the high power source and the NFM device. Further, polarization conversion using Raman or Brillouin wavelength shifting is provided to optimize frequency conversion efficiency in the NFM device.

  2. High power operation of cladding pumped holmium-doped silica fibre lasers.

    PubMed

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency. PMID:23481989

  3. Nonlinear femtosecond pump-probe spectroscopy using a power-encoded soliton delay line.

    PubMed

    Saint-Jalm, Sarah; Andresen, Esben Ravn; Bendahmane, Abdelkrim; Kudlinski, Alexandre; Rigneault, Hervé

    2016-01-01

    We show femtosecond time-resolved nonlinear pump-probe spectroscopy using a fiber soliton as the probe pulse. Furthermore, we exploit soliton dynamics to record an entire transient trace with a power-encoded delay sweep. The power-encoded delay line takes advantage of the dependency of the soliton trajectory in the (λ,z) space upon input power; the difference in accumulated group delay between trajectories converts a fast power sweep into a fast delay sweep. We demonstrate the concept by performing transient absorption spectroscopy in a test sample and validate it against a conventional pump-probe setup. PMID:26696172

  4. Commercial Impact and Optimum Capacity Determination of Pumped Storage Hydro Plant for a Practical Power System

    NASA Astrophysics Data System (ADS)

    Latha, P. G.; Anand, S. R.; Imthias, Ahamed T. P.; Sreejith, P. S., Dr.

    2013-06-01

    This paper attempts to study the commercial impact of pumped storage hydro plant on the operation of a stressed power system. The paper further attempts to compute the optimum capacity of the pumped storage scheme that can be provided on commercial basis for a practical power system. Unlike the analysis of commercial aspects of pumped storage scheme attempted in several papers, this paper is presented from the point of view of power system management of a practical system considering the impact of the scheme on the economic operation of the system. A realistic case study is presented as the many factors that influence the pumped storage operation vary widely from one system to another. The suitability of pumped storage for the particular generation mix of a system is well explored in the paper. To substantiate the economic impact of pumped storage on the system, the problem is formulated as a short-term hydrothermal scheduling problem involving power purchase which optimizes the quantum of power to be scheduled and the duration of operation. The optimization model is formulated using an algebraic modeling language, AMPL, which is then solved using the advanced MILP solver CPLEX.

  5. Fundamental-frequency-absorbed oxyfluoride glass in a high-power laser.

    PubMed

    Hou, Chaoqi; Li, Weinan; Wang, Pengfei; Lu, Min; Peng, Bo; Guo, Haitao; Gao, Fei; Cui, Xiaoxia

    2016-04-01

    A high-power third-harmonic laser faces challenges in the filtering remnant unconverted fundamental frequency, which is from the frequency converting crystal. In this work, a novel fundamental-frequency-absorbed oxyfluoride glass has been prepared, which provides a possible option to solve the problem. By being doped with Fe2+ ion, the glass shows strong absorption property at 1053 nm, and the glass's transmittances at 351 and 1053 nm are stable with changing the laser power or increasing the irradiation times under high-power laser irradiation. Meanwhile, the laser-induced damage threshold of the glass is 12.5  J/cm2 at 351 nm, which is two times higher than that of fused silica whose threshold is 6.2  J/cm2 in the same testing condition. The glass also exhibits a higher laser-induced damage threshold as well as 36.6  J/cm2 at its absorption wavelength of 1053 nm. The results indicate that this glass is promising as a color-separation optic, thus allowing a novel design for the final optics assembly in an inertial confinement fusion laser system. PMID:27139668

  6. Examination of pump failure data in the nuclear power industry

    SciTech Connect

    Casada, D.

    1996-12-01

    There are several elements that are critical to any program which is used to optimize the availability and reliability of process equipment. Perhaps the most important elements are routine monitoring and predictive maintenance elements. In order to optimize equipment monitoring and predictive maintenance, it is necessary to fundamentally and thoroughly understand the principal failure modes for the equipment and the effectiveness of alternative monitoring methods. While these observations are general in nature, they are certainly true for the {open_quotes}heart{close_quotes} of fluid systems - pumps. In recent years, particularly within the last decade, the capabilities and ease of use of previously existing pump diagnostic technologies, such as vibration monitoring and oil analysis, have improved dramatically. Newer technologies, such as thermal imaging, have been found effective at detecting certain undesirable or degraded conditions, such as misalignment and overheated bearings or packing. The ASME Code and NRC regulatory requirements have been, like essentially all similar code and regulatory bodies, conservative in their adoption or endorsement of newer technologies. The requirements prescribed by the Code and endorsed by the NRC have, in their essence, changed only minimally over more than a dozen years. As a follow-on to studies of check valve failure experience in the nuclear industry that have proven useful in identifying the effectiveness of alternative monitoring methods, a study of nuclear industry pump failure data has been conducted. The results of this study, conducted for the NRC by Oak Ridge National Laboratory, are presented. The historical effectiveness of both regulatory required and voluntarily implemented pump monitoring programs are shown. The distribution of pump failures by application, affected area, and level of significance are indicated. Apparent strengths and weaknesses of alternative monitoring methods are discussed.

  7. Pump combiner loss as a function of input numerical aperture power distribution

    NASA Astrophysics Data System (ADS)

    Sévigny, Benoit; Poirier, Pierre; Faucher, Mathieu

    2009-02-01

    High-power combiner designs (such as kilowatt-class combiners and beyond) are increasingly aggressive on brightness conservation in order to reduce the brightness loss of the pumps as much as possible in both direct diode combining and pump and signal coupling, especially with the advent of next-generation high-power pumps. Since most of the pump loss is due to brightness loss across the combiner, tighter designs (close to the brightness limit) are considerably more sensitive to variations in the input power distribution as a function of numerical aperture; for instance, next-generation, high-power multi-emitter pumps are likely to have larger numerical apertures than conventional single-emitter diodes. As a consequence, pump insertion loss for a given combiner design sitting close to the brightness limit should be dependant on the input power distribution. Aside from presenting a manufacturing challenge, high brightness combiners also imply more sophisticated testing to allow a deeper understanding of the loss with respect to the far-field distribution of the pump inputs and thus enable the extrapolation of loss for an arbitrary, cylindrically symmetric radiant intensity distribution. In this paper, we present a novel test method to measure loss as a function of numerical aperture (NA) fill factor using a variable NA source with square-shaped far field distributions. Results are presented for a range of combiners, such as 7x1 and 19x1 pump combiners, with different brightness ratio and fiber inputs. Combiners violating the brightness conservation equation are also characterized in order to estimate the loss as a function of input power vs. NA distribution and fill factor.

  8. Study of photoproducts of Rhodamine 6G in ethanol upon powerful laser pumping

    SciTech Connect

    Batishche, S.A.; Malevich, N.A.; Mostovnikov, V.A.

    1995-04-01

    Absorption spectra of rhodamine 6G in ethanol solution are measured using, the technique of laser probing upon pumping by a doubled Nd {sup 3+}:YAG laser with pulse length{tau}{sub 01}{approx_equal}16ns. It is shown that, at the pumping energy density {ge}1.5 J/cm{sup 2}, short-lived ({tau} < 25 ns) and long-lived photoproducts formed in the dye solution, which absorbed in a wide spectral range, including the lasing region. The estimates show that the probability of rhodamine 6G transformation to the photoproduct upon three-step excitation at 532 nm achieves {approximately}2.5 X 10{sup -3}. It is noted that, in order to obtain reliable spectroscopic information using this technique, one should take into account the intense scattering of probing radiation by thermal noise gratings, which are formed due to self-diffraction of the pumping radiation into noise components.

  9. Optimal Operation Scheduling of Pumped Storage Hydro Power Plant in Power System with a Large Penetration of Photovoltaic Generations

    NASA Astrophysics Data System (ADS)

    Aihara, Ryota; Yokoyama, Akihiko; Nomiyama, Fumitoshi; Kosugi, Narifumi

    In recent years, a substantial amount of photovoltaic (PV) generations have been installed in power systems. However, the power output from the PVs is random and intermittent in nature. Therefore, the PV generations pose many challenges to the power system operation. To solve these issues, we propose that pumped storage hydro power plant (PSHPP) is used effectively. In this paper, a new method for scheduling effective operating patterns for PSHPP that make it possible to improve both reliability and economy is presented.

  10. Single-walled carbon nanotube saturable absorber for a diode-pumped passively mode-locked Nd,Y:SrF2 laser

    NASA Astrophysics Data System (ADS)

    Li, Chun; Cai, Wei; Liu, Jie; Su, Liangbi; Jiang, Dapeng; Ma, Fengkai; Zhang, Qian; Xu, Jun; Wang, Yonggang

    2016-08-01

    A reflective single-walled carbon nanotube as saturable absorber has been firstly adopted to a passively mode-locked Nd,Y:SrF2 crystal. Without any dispersion compensation, the stably mode-locked laser delivers pulses with pulse width as short as 1.7 ps, repetition rate of 107.8 MHz and center wavelength of 1056 nm. The oscillator produces maximum average output power of 319 mW corresponding with a high slope efficiency of 20.2%. The single pulse energy and the peak power are 2.96 nJ and 1.74 kW, respectively. The experimental results show that single-walled carbon nanotube is an excellent saturable absorber for mode-locked lasers.

  11. Light-powered, artificial molecular pumps: a minimalistic approach.

    PubMed

    Ragazzon, Giulio; Baroncini, Massimo; Silvi, Serena; Venturi, Margherita; Credi, Alberto

    2015-01-01

    The realization of artificial molecular motors capable of converting energy into mechanical work is a fascinating challenge of nanotechnology and requires reactive systems that can operate away from chemical equilibrium. This article describes the design and construction of a simple, supramolecular ensemble in which light irradiation causes the directional transit of a macrocycle along a nonsymmetric molecular axle, thus forming the basis for the development of artificial molecular pumps. PMID:26665081

  12. Light-powered, artificial molecular pumps: a minimalistic approach

    PubMed Central

    Ragazzon, Giulio; Baroncini, Massimo; Silvi, Serena; Venturi, Margherita

    2015-01-01

    Summary The realization of artificial molecular motors capable of converting energy into mechanical work is a fascinating challenge of nanotechnology and requires reactive systems that can operate away from chemical equilibrium. This article describes the design and construction of a simple, supramolecular ensemble in which light irradiation causes the directional transit of a macrocycle along a nonsymmetric molecular axle, thus forming the basis for the development of artificial molecular pumps. PMID:26665081

  13. High power diode pumped solid state laser development at Lawrence Livermore National Laboratory

    SciTech Connect

    Solarz, R.; Albrecht, G.; Hackel, L.

    1994-03-01

    The authors recent developments in high powered diode pumped solid state lasers at Lawrence Livermore National Laboratory. Over the past year the authors have made continued improvements to semiconductor pump array technology which includes the development of higher average power and lower cost pump modules. They report the performance of high power AlGaAs, InGaAs, and AlGaInP arrays. They also report on improvement to the integrated micro-optics designs in conjunction with lensing duct technology which gives rise to very high performance end pumping designs for solid state lasers which have major advantages which they detail. Substantial progress on beam quality improvements to near the diffraction limit at very high power have also been made and will be reported. They also will discuss recent experiments on high power non-linear materials for q-switches, harmonic converters, and parametric oscillators. Advances in diode pumped devices at LLNL which include tunable Cr:LiSrAlF{sub 6}, mid-IR Er:YAG, holmium based lasers and other developments will also be outlined. Concepts for delivering up to 30 kilowatts of average power from a DPSSL oscillator will be described.

  14. Volume Bragg grating narrowed high-power and highly efficient cladding-pumped Raman fiber laser.

    PubMed

    Liu, Jun; Yao, Weichao; Zhao, Chujun; Shen, Deyuan; Fan, Dianyuan

    2014-12-10

    High-power and highly efficient operation of a single-mode cladding-pumped Raman fiber laser with narrow lasing bandwidth is demonstrated. The spectral narrowing was realized by an external cavity containing a volume Bragg grating with a center wavelength of 1658 nm. A maximum output power of 10.4 W at 1658.3 nm with a spectral linewidth (FWHM) of ∼0.1  nm was obtained for the launched pump power of 18.4 W, corresponding to a slope efficiency of 109% with respect to the launched pump power. Lasing characteristics of free-running operation are also evaluated and discussed. PMID:25608067

  15. FALCON nuclear-reactor-pumped laser program and wireless power transmission

    SciTech Connect

    Lipinski, R.J.; Pickard, P.S.

    1992-12-31

    FALCON is a high-power, reactor-pumped laser concept. The major strengths of a reactor-pumped laser are (1) simple, modular construction, (2) long-duration, closed-cycle capability, (3) self-contained power, (4) compact size, and (5) a variety of wavelengths (from visible to infrared). Reactor-pumped lasing has been demonstrated experimentally in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. Powers up to 300 W for 2 ms have been demonstrated. Projected beam quality for FALCON is good enough that frequency doubling at reasonable efficiencies could be expected to yield wavelengths at 353, 363, 636, 867, 896, 1016, 1315, 1325, and 1685 nm. Appropriate missions for FALCON are described and include power beaming to satellites, the moon, and unmanned surveillance planes; lunar mapping; space debris removal; and laser propulsion.

  16. FALCON nuclear-reactor-pumped laser program and wireless power transmission

    SciTech Connect

    Lipinski, R.J.; Pickard, P.S.

    1992-01-01

    FALCON is a high-power, reactor-pumped laser concept. The major strengths of a reactor-pumped laser are (1) simple, modular construction, (2) long-duration, closed-cycle capability, (3) self-contained power, (4) compact size, and (5) a variety of wavelengths (from visible to infrared). Reactor-pumped lasing has been demonstrated experimentally in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. Powers up to 300 W for 2 ms have been demonstrated. Projected beam quality for FALCON is good enough that frequency doubling at reasonable efficiencies could be expected to yield wavelengths at 353, 363, 636, 867, 896, 1016, 1315, 1325, and 1685 nm. Appropriate missions for FALCON are described and include power beaming to satellites, the moon, and unmanned surveillance planes; lunar mapping; space debris removal; and laser propulsion.

  17. Hand-powered microfluidics: A membrane pump with a patient-to-chip syringe interface

    PubMed Central

    Gong, Max M.; MacDonald, Brendan D.; Vu Nguyen, Trung; Sinton, David

    2012-01-01

    In this paper, we present an on-chip hand-powered membrane pump using a robust patient-to-chip syringe interface. This approach enables safe sample collection, sample containment, integrated sharps disposal, high sample volume capacity, and controlled downstream flow with no electrical power requirements. Sample is manually injected into the device via a syringe and needle. The membrane pump inflates upon injection and subsequently deflates, delivering fluid to downstream components in a controlled manner. The device is fabricated from poly(methyl methacrylate) (PMMA) and silicone, using CO2 laser micromachining, with a total material cost of ∼0.20 USD/device. We experimentally demonstrate pump performance for both deionized (DI) water and undiluted, anticoagulated mouse whole blood, and characterize the behavior with reference to a resistor-capacitor electrical circuit analogy. Downstream output of the membrane pump is regulated, and scaled, by connecting multiple pumps in parallel. In contrast to existing on-chip pumping mechanisms that typically have low volume capacity (∼5 μL) and sample volume throughput (∼1–10 μl/min), the membrane pump offers high volume capacity (up to 240 μl) and sample volume throughput (up to 125 μl/min). PMID:24143160

  18. Electrical power free, low dead volume, pressure-driven pumping for microfluidic applications

    PubMed Central

    Moscovici, Mario; Chien, Wei-Yin; Abdelgawad, Mohamed; Sun, Yu

    2010-01-01

    This paper presents a simple-to-construct, low dead volume pump capable of generating a wide range of positive and negative pressures for microfluidic applications. The pump generates pressure or vacuum by changing the volume of air confined inside a syringe and is able to generate pressures between −95 and +300 kPa with a resolution as high as 1 Pa. Different from syringe pumps and electrokinetic pumping, which are capable of controlling flow rates only, our pump can be used to generate constant flow rates or constant pressures, which are required for certain applications such as the aspiration of biological cells for biophysical characterization. Compared to syringe pumps, the new pump has almost zero dead volume and does not exhibit pulsatile flows. Additionally, the system does not require electrical power and is cost effective (∼$100). To demonstrate the capabilities of the pump, we used it to aspirate osteoblasts (MC3T3-E1 cells) and to determine Young’s modulus of the cells, to generate a concentration gradient, and to produce variable-sized droplets in microchannels using hydrodynamic focusing. PMID:21057609

  19. Results of TC-1 boost pump icing tests in the space power facility

    NASA Technical Reports Server (NTRS)

    Gentile, L. C.; Walter, R. J.

    1975-01-01

    A series of tests were conducted in the space power facility to investigate the failure of the Centaur oxidizer boost pump during the Titan/Centaur proof flight February 11, 1974. The three basic objectives of the tests were: (1) demonstrate if an evaporative freezing type failure mechanism could have prevented the pump from operating, (2) determine if steam from the exhaust of one of the attitude control engine could have entered a pump seal cavity and caused the failure, and (3) obtain data on the heating effects of the exhaust plume from a hydrogen peroxide attitude control engine.

  20. Design of a Mechanical NaK Pump for Fission Space Power Systems

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David; Godfroy, Thomas

    2010-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for mid-range spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid. Traditionally, linear induction pumps have been used to provide the required flow and head conditions for liquid metal systems but can be limited in performance. This paper details the design, build, and check-out test of a mechanical NaK pump. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  1. Optimization of fluid line sizes with pumping power penalty IBM-360 computer program

    NASA Technical Reports Server (NTRS)

    Jelinek, D.

    1972-01-01

    Computer program has been developed to calculate and total weights for tubing, fluid in tubing, and weight of fuel cell power source necessary to power pump based on flow rate and pressure drop. Program can be used for fluid systems used in any type of aircraft, spacecraft, trucks, ships, refineries, and chemical processing plants.

  2. Optimization of gas dynamic and power parameters for continuous nuclear pumped laser

    NASA Astrophysics Data System (ADS)

    Korzenev, A. N.; Sizov, A. N.

    2008-01-01

    Optimization studies of optical and power performances of nuclear pumped lasers are performed. It is shown that the laser mix pump rate speed-up from 7 to 30 m/s and laser channel width reduction from 2 to 1 cm allows increasing the average specific energy input by the factor of 1.6 and narrowing the refraction factor measuring interval for 4 times.

  3. A review of vibration problems in power station boiler feed pumps

    NASA Technical Reports Server (NTRS)

    France, David

    1994-01-01

    Boiler feed pump reliability and availability is recognized as important to the overall efficiency of power generation. Vibration monitoring is often used as a part of planned maintenance. This paper reviews a number of different types of boiler feed pump vibration problems describing some methods of solution in the process. It is hoped that this review may assist both designers and users faced with similar problems.

  4. Solid-state laser-pumped high-power electric-discharge HF laser

    SciTech Connect

    Velikanov, S D; Garanin, Sergey G; Kodola, B E; Komarov, Yu N; Shchurov, V V; Efanov, V M; Efanov, M V; Yarin, P M; Kazantsev, S Yu; Kononov, I G; Firsov, K N; Domazhirov, A P; Podlesnykh, S V; Sivachev, A A

    2010-08-03

    We report the possibility of creating high-power nonchain electric-discharge HF lasers with an all-solid-state pump source. The maximum energy stored in the pump source capacitors based on solid-state FID-switches is 990 J for the open-circuit voltage of 240 kV. The pulse energy of 30 J is obtained in the hydrogen-containing SF{sub 6} mixture at the electric efficiency of the order of 3%. (lasers)

  5. Vehicle having hydraulic and power steering systems using a single high pressure pump

    DOEpatents

    Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

    2001-06-22

    A vehicle comprises a plurality of wheels attached to a vehicle housing. Also attached to the vehicle housing is a power steering system, including a fluid flow circuit, which is operably coupled to a number of the wheels. An internal combustion engine attached to the vehicle housing is connected to a hydraulically actuated system that includes a high pressure pump. An outlet of the high pressure pump is in fluid communication with the fluid flow circuit.

  6. Low-power photolytically pumped lasers: Final technical report

    SciTech Connect

    Messing, I.; Lorents, D.C.; Eckstrom, D.J.

    1987-08-01

    We have carried out an extensive series of measurements of the time-resolved Xe/sub 2/* emission spectra following optical pumping by a short-pulse F/sub 2/ laser at 157.6 nm. Most measurements were performed using a gated Optical Multichannel Analyzer detector; we also made measurements using a scanning monochromator fitted with a photomultiplier and using a boxcar integrator for time resolution. The two sets of results agree well and show that both the singlet and triplet emission bands are broader than expected and have center wavelengths closer together than expected. Measurements were performed both at room temperature and at elevated (140/sup 0/C) and reduced (-27/sup 0/C) temperatures. The broad bandwidth of the individual spectral bands was unexpected and conflicted with a previous spectral measurement using optical pumping by the Xe* resonance line from a microwave discharge lamp. Therefore, we also performed a series of spectral measurements using this type of optical pumping. We achieved good agreement with some previous results in the literature, but not with the result in question. We conclude that the present results are reliable. The results presented in this report provide the first definitive measurement of the individual excimer emissions from each of the Xe/sub 2/(0/sub u//sup +/) and Xe/sub 2/(1/sub u/) states. From these measurements and the known ground state potential, we derived a 1/sub u/ potential that reproduces the emission band very well. However, the 1/sub u/ potential is in substantial disagreement with the recent 1/sub u/ potential derived by the Toronto group. 13 refs., 32 figs., 3 tabs.

  7. Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site

    SciTech Connect

    David Hudson, Charles Lohrstorfer, Bruce Hurley

    2007-05-03

    Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and characterized before subsequent disposition. The configuration of most wells requires sampling stagnant well water with a wireline bailer. Although bailer sampling allows for the collection of depth-discrete samples, the collected samples may not be representative of local groundwater because no well purging is done. Low-maintenance, solar-powered jack pumps will be deployed in nine of these onsite monitoring wells to improve sample quality. These pumps provide the lift capacity to produce groundwater from the deep aquifers encountered in the arid environment of the NTS. The water depths in these wells range from 700 to 2,340 ft below ground surface. The considerable labor and electrical power requirements of electric submersible pumps are eliminated once these pumps are installed. Access tubing will be installed concurrent with the installation of the pump string to provide downhole access for water-level measurements or other wireline instruments. Micro-purge techniques with low pump rates will be used to minimize purge volumes and reduce hydraulic gradients. The set depths of the pumps will be determined by the borehole characteristics and screened interval.

  8. Certification report for the CALMAC solar powered pump

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The certification of the CALMAC solar powered thermopump is presented. Each element of the specification is delineated, together with the verification, based on analysis, similarity, inspection, or testing.

  9. Improvement of the main pump equipment used in large thermal power installations

    NASA Astrophysics Data System (ADS)

    Morgunov, G. M.

    2010-12-01

    The establishment and development history of the Moscow Power Engineering Institute's Department of Hydromechanics and Hydraulic Machines, and the educational and scientific work presently conducted at it are briefly described. The research and design work aimed at developing the optimal construction of the flow path and blade systems for the stages of a feedwater pump with a useful capacity of 25 MW with the traditional one-sided admission of working fluid for power units designed to operate at supercritical steam conditions is discussed. A new alternative design solution for the cartridge of a super-powerful feedwater pump with the two-sided admission of working fluid is presented. The predicted possibility of achieving more reliable and energy-efficient performance of a feedwater pump equipped with such a cartridge is substantiated.

  10. Discharge formation in a XеCl laser pumped by high specific power

    NASA Astrophysics Data System (ADS)

    Panchenko, Yu. N.; Losev, V. F.

    2013-02-01

    Stable glow of the discharge of various types in the gas mixture of a XeCl laser is investigated for specific pumping power in the range 1.2-4.6 MW/cm3 and pulse duration of 40 ns. It is demonstrated that formation of partially homogeneous plasma with many intensive cathode spots on the electrode allows the maximum energy and duration of the lasing pulse to be obtained with laser efficiency of 2.4%. It is revealed that for the specific pumping powers up to 1.5 MW/cm3, a very homogeneous volume discharge with a small number of lowintensive cathode spots is formed in the discharge gap. With further increase in the specific pumping power exceeding 4.5 MW/cm3, current microinhomogeneities are formed in the volume discharge of this type leading to lasing breakdown.

  11. Analysis of a Static Start-up Control Strategy for Pumped Storage Power Plant Unit

    NASA Astrophysics Data System (ADS)

    Wang, Deshun; Yang, Bo; Li, Guanjun; Tao, Yibin; Sang, Bingyu

    A static start-up control strategy for pumped storage power plant unit is presented and the sensor less control to rotor position detecting is analyzed according to voltage and magnetism equations of ideal synchronous motor mathematics model. The simple-to-implement estimation technique of sensor less control to rotor position detecting in which operates over a wide speed range, including zero speed, is presented also. Control strategy of static start-up and its mathematical model is discussed in detail. Based on 500 kW synchronous motor, the test of static start- up control system for pumped storage power plant unit is developed. Test results show that pulse commutation, nature commutation and unit synchronous procedure of static start-up are realized. Then it is proved that the method presented in the paper is a practicable control strategy for static start-up control to pumped storage power plant.

  12. Improving Reliability of High Power Quasi-CW Laser Diode Arrays for Pumping Solid State Lasers

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Baggott, Renee S.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.

    2005-01-01

    Most Lidar applications rely on moderate to high power solid state lasers to generate the required transmitted pulses. However, the reliability of solid state lasers, which can operate autonomously over long periods, is constrained by their laser diode pump arrays. Thermal cycling of the active regions is considered the primary reason for rapid degradation of the quasi-CW high power laser diode arrays, and the excessive temperature rise is the leading suspect in premature failure. The thermal issues of laser diode arrays are even more drastic for 2-micron solid state lasers which require considerably longer pump pulses compared to the more commonly used pump arrays for 1-micron lasers. This paper describes several advanced packaging techniques being employed for more efficient heat removal from the active regions of the laser diode bars. Experimental results for several high power laser diode array devices will be reported and their performance when operated at long pulsewidths of about 1msec will be described.

  13. Power scaling of resonantly cladding-pumped, Yb-free, Er-doped LMA fiber lasers

    NASA Astrophysics Data System (ADS)

    Dubinskii, M.; Zhang, J.; Kudryashov, I.

    2009-04-01

    The results of the recent major efforts in power scaling of resonantly cladding-pumped Yb-free Er fiber lasers are presented. Commercially available Yb-free Er-doped large mode area Er60-20/125 (LMA) DC fibers were tested in two regimes: (i), as a booster amplifier in a single-frequency (SF) MOPA configuration and, (ii), in a Bragg grating (FBG) based narrowband fiber laser configuration. We obtained ˜28.5 W of output power at 1590 nm, the highest power reported so far out of Yb-free Er-doped LMA fiber with resonant cladding pumping. The achieved optical-to-optical conversion slope efficiency of ˜56.6% is also believed to be the highest efficiency ever reported from Yb-free Er-doped fiber laser with resonant cladding pumping.

  14. Stability analysis of the Gyroscopic Power Take-Off wave energy point absorber

    NASA Astrophysics Data System (ADS)

    Nielsen, Søren R. K.; Zhang, Zili; Kramer, Morten M.; Olsen, Jan

    2015-10-01

    The Gyroscopic Power Take-Off (GyroPTO) wave energy point absorber consists of a float rigidly connected to a lever. The operational principle is somewhat similar to that of the so-called gyroscopic hand wrist exercisers, where the rotation of the float is brought forward by the rotational particle motion of the waves. At first, the equations of motion of the system are derived based on analytical rigid body dynamics. Next, assuming monochromatic waves simplified equations are derived, valid under synchronisation of the ring of the gyro to the angular frequency of the excitation. Especially, it is demonstrated that the dynamics of the ring can be described as an autonomous nonlinear single-degree-of-freedom system, affected by three different types of point attractors. One where the ring vibrations are attracted to a static equilibrium point indicating unstable synchronisation and two types of attractors where the ring is synchronised to the wave angular frequency, either rotating in one or the opposite direction. Finally, the stability conditions and the basins of attraction to the point attractors defining the synchronised motion are determined.

  15. A novel all-in-one magnetic pump and power harvester design for bio-medical applications

    NASA Astrophysics Data System (ADS)

    Kim, Sung Hoon; Shin, Jaewon; Hashi, Shuichiro; Ishiyama, Kazushi

    2011-03-01

    This paper presents a magnetic centrifugal pump with a magnetic power harvester (all-in-one system) for medical applications. The proposed pump is driven by an external rotating magnetic field. To produce pressure and electrical power, an all-in-one device consisting of a pump and a power harvester was designed. It consists of a multi-stage impeller, a disc type NdFeB permanent magnet, and a fixed wound coil on the pump case. The rotation of the rotor creates a continuous flow of liquid through the pump, with a pressure head, and an electrical power is generated in the wound coil because of the rotating magnetic field. The maximum flow rate and pressure are 5000 ml min-1 and 16 kPa, respectively, at 100 Hz. These results meet the requirements of an artificial heart assistance blood pump. Under these operating conditions, the harvested voltage can reach a maximum of 8.2 Vp-p. With this configuration and control method, wireless and battery-free operation is possible, which is required in the medical field. Moreover, the power harvester can monitor the pump conditions without additional electrical power and can provide electrical power to other implanted electrical devices. The performances of the pump and power harvester were verified in a laboratory experiment. Overall, the proposed system acts as a pump and a power harvester that is fully wireless and battery-free.

  16. Sub-100 fs high average power directly blue-diode-laser-pumped Ti:sapphire oscillator

    NASA Astrophysics Data System (ADS)

    Rohrbacher, Andreas; Markovic, Vesna; Pallmann, Wolfgang; Resan, Bojan

    2016-03-01

    Ti:sapphire oscillators are a proven technology to generate sub-100 fs (even sub-10 fs) pulses in the near infrared and are widely used in many high impact scientific fields. However, the need for a bulky, expensive and complex pump source, typically a frequency-doubled multi-watt neodymium or optically pumped semiconductor laser, represents the main obstacle to more widespread use. The recent development of blue diodes emitting over 1 W has opened up the possibility of directly diode-laser-pumped Ti:sapphire oscillators. Beside the lower cost and footprint, a direct diode pumping provides better reliability, higher efficiency and better pointing stability to name a few. The challenges that it poses are lower absorption of Ti:sapphire at available diode wavelengths and lower brightness compared to typical green pump lasers. For practical applications such as bio-medicine and nano-structuring, output powers in excess of 100 mW and sub-100 fs pulses are required. In this paper, we demonstrate a high average power directly blue-diode-laser-pumped Ti:sapphire oscillator without active cooling. The SESAM modelocking ensures reliable self-starting and robust operation. We will present two configurations emitting 460 mW in 82 fs pulses and 350 mW in 65 fs pulses, both operating at 92 MHz. The maximum obtained pulse energy reaches 5 nJ. A double-sided pumping scheme with two high power blue diode lasers was used for the output power scaling. The cavity design and the experimental results will be discussed in more details.

  17. Packaging of high-power bars for optical pumping and direct applications

    NASA Astrophysics Data System (ADS)

    Heinemann, Stefan; An, Haiyan; Barnowski, Tobias; Jiang, John; Negoita, Viorel; Roff, Robert; Vethake, Thilo; Boucke, Konstantin; Treusch, Georg

    2015-03-01

    Continuous cost reduction, improved reliability and modular platform guide the design of our next generation heatsink and packaging process. Power scaling from a single device effectively lowers the cost, while electrical insulation of the heatsink, low junction temperature and hard solder enable high reliability. We report on the latest results for scaling the output power of bars for optical pumping and materials processing. The epitaxial design and geometric structures are specific for the application, while packaging with minimum thermal impedance, low stress and low smile are generic features. The isolated heatsink shows a thermal impedance of 0.2 K/W and the maximum output power is limited by the requirement of a junction temperature of less than 68oC for high reliability. Low contact impedance are addressed for drive currents of 300 A. For pumping applications, bars with a fill factor of 60% are deployed emitting more than 300 W of output power with an efficiency of about 55% and 8 bars are arranged in a compact pump module emitting 2 kW of collimated power suitable for pumping disk lasers. For direct applications we target coupling kilowatts of output powers into fibers of 100 μm diameter with 0.1 NA based on dense wavelength multiplexing. Low fill factor bars with large optical waveguide and specialized coating also emit 300 W.

  18. Improved performance of high average power semiconductor arrays for applications in diode pumped solid state lasers

    SciTech Connect

    Beach, R.; Emanuel, M.; Benett, W.; Freitas, B.; Ciarlo, D.; Carlson, N.; Sutton, S.; Skidmore, J.; Solarz, R.

    1994-01-01

    The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL`s). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL`s which are appropriate for material processing applications, low and intermediate average power DPSSL`s are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications.

  19. Performance of an Annular Linear Induction Pump with Applications to Space Nuclear Power Systems

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Schoenfeld, Michael; Pearson, J. Boise; Webster, Kenneth; Godfroy, Thomas; Adkins, Harold E., Jr.; Werner, James E.

    2010-01-01

    Results of performance testing of an annular linear induction pump are presented. The pump electromagnetically pumps liquid metal through a circuit specially designed to allow for quantification of the performance. Testing was conducted over a range of conditions, including frequencies of 33, 36, 39, and 60 Hz, liquid metal temperatures from 125 to 525 C, and input voltages from 5 to 120 V. Pump performance spanned a range of flow rates from roughly 0.16 to 5.7 L/s (2.5 to 90 gpm), and pressure head less than 1 to 90 kPa (less than 0.145 to 13 psi). The maximum efficiency measured during testing was slightly greater than 6%. The efficiency was fairly insensitive to input frequency from 33 to 39 Hz, and was markedly lower at 60 Hz. In addition, the efficiency decreased as the NaK temperature was raised. The performance of the pump operating on a variable frequency drive providing 60 Hz power compared favorably with the same pump operating on 60 Hz power drawn directly from the electrical grid.

  20. Self sufficient wireless transmitter powered by foot-pumped urine operating wearable MFC.

    PubMed

    Taghavi, M; Stinchcombe, A; Greenman, J; Mattoli, V; Beccai, L; Mazzolai, B; Melhuish, C; Ieropoulos, I A

    2016-02-01

    The first self-sufficient system, powered by a wearable energy generator based on microbial fuel cell (MFC) technology is introduced. MFCs made from compliant material were developed in the frame of a pair of socks, which was fed by urine via a manual gaiting pump. The simple and single loop cardiovascular fish circulatory system was used as the inspiration for the design of the manual pump. A wireless programmable communication module, engineered to operate within the range of the generated electricity, was employed, which opens a new avenue for research in the utilisation of waste products for powering portable as well as wearable electronics. PMID:26657063

  1. Synchronously pumped optical parametric oscillation in periodically poled lithium niobate with 1-w average output power.

    PubMed

    Graf, T; McConnell, G; Ferguson, A I; Bente, E; Burns, D; Dawson, M D

    1999-05-20

    We report on a rugged all-solid-state laser source of near-IR radiation in the range of 1461-1601 nm based on a high-power Nd:YVO(4) laser that is mode locked by a semiconductor saturable Bragg reflector as the pump source of a synchronously pumped optical parametric oscillator with a periodically poled lithium niobate crystal. The system produces 34-ps pulses with a high repetition rate of 235 MHz and an average output power of 1 W. The relatively long pulses lead to wide cavity detuning tolerances. The comparatively narrow spectral bandwidth of <15 GHz is suitable for applications such as pollutant detection. PMID:18319928

  2. Concentrating Solar Power - Molten Salt Pump Development, Final Technical Report (Phase 1)

    SciTech Connect

    Michael McDowell; Alan Schwartz

    2010-03-31

    The purpose of this project is to develop a long shafted pump to operate at high temperatures for the purpose of producing energy with renewable resources. In Phase I of this three phase project we developed molten salt pump requirements, evaluated existing hardware designs for necessary modifications, developed a preliminary design of the pump concept, and developed refined cost estimates for Phase II and Phase III of the project. The decision has been made not to continue the project into Phases II and III. There is an ever increasing world-wide demand for sources of energy. With only a limited supply of fossil fuels, and with the costs to obtain and produce those fuels increasing, sources of renewable energy must be found. Currently, capturing the sun's energy is expensive compared to heritage fossil fuel energy production. However, there are government requirements on Industry to increase the amount of energy generated from renewable resources. The objective of this project is to design, build and test a long-shafted, molten salt pump. This is the type of pump necessary for a molten salt thermal storage system in a commercial-scale solar trough plant. This project is under the Department of Energy (DOE) Solar Energy Technologies Program, managed by the Office of Energy Efficiency and Renewable Energy. To reduce the levelized cost of energy (LCOE), and to meet the requirements of 'tomorrows' demand, technical innovations are needed. The DOE is committed to reducing the LCOE to 7-10 cents/kWh by 2015, and to 5-7 cents/kWh by 2020. To accomplish these goals, the performance envelope for commercial use of long-shafted molten salt pumps must be expanded. The intent of this project is to verify acceptable operation of pump components in the type of molten salt (thermal storage medium) used in commercial power plants today. Field testing will be necessary to verify the integrity of the pump design, and thus reduce the risk to industry. While the primary goal is to

  3. New Class of CW High-Power Diode-Pumped Alkali Lasers (DPALs)

    SciTech Connect

    Krupke, W F; Beach, R J; Kanz, V K; Payne, S A; Early, J T

    2004-03-23

    The new class of diode-pumped alkali vapor lasers (DPALs) offers high efficiency cw laser radiation at near-infrared wavelengths: cesium 895 nm, rubidium 795 nm, and potassium 770 nm. The working physical principles of DPALs will be presented. Initial 795 nm Rb and 895 nm Cs laser experiments performed using a titanium sapphire laser as a surrogate pump source demonstrated DPAL slope power conversion efficiencies in the 50-70% range, in excellent agreement with device models utilizing only literature spectroscopic and kinetic data. Using these benchmarked models for Rb and Cs, optimized DPALs with optical-optical efficiencies >60%, and electrical efficiencies of 25-30% are projected. DPAL device architectures for near-diffraction-limited power scaling into the high kilowatt power regime from a single aperture will be described. DPAL wavelengths of operation offer ideal matches to silicon and gallium arsenide based photovoltaic power conversion cells for efficient power beaming.

  4. High Power Diode Pumped 1.06 Micron Solid State Laser

    NASA Astrophysics Data System (ADS)

    Arvind, Mukundarajan A.; Martin, Dan W.; Osterhage, R. J.

    1989-07-01

    Diode pumped solid state lasers have been attracting significant interest in recent years due to advances in high power semiconductor diode lasers. They offer considerable advantages over flashlamp pumped lasers such as compact size, high efficiency, lower heat dissipation and solid-state reliability. In this paper, we report on the results of a Nd:YAG laser, transverse pumped by diode laser arrays. We have measured an output power of 1.14 Watts at 1.06 microns with a laser diode power consumption of 40 Watts. This represents the highest reported electrical efficiency (2.85%) for a transverse pumped, CW, TEM00 laser. The diode arrays were selected and tuned to emit at wavelengths close to the peak neodymium absorption line at 0.808 microns with Peltier coolers. Two diode laser bars side pumped a 20 mm long, 1.5 mm diameter Nd:YAG laser rod. The optical cavity is 13.8 cm long consisting of a high reflectivity mirror and a 95% reflectivity output mirror. The output beam divergence was measured to be near diffraction limited at 1.4 milliradians, and the beam diameter was 1 mm.

  5. Fiber laser pumped high power mid-infrared laser with picosecond pulse bunch output.

    PubMed

    Wei, Kaihua; Chen, Tao; Jiang, Peipei; Yang, Dingzhong; Wu, Bo; Shen, Yonghang

    2013-10-21

    We report a novel quasi-synchronously pumped PPMgLN-based high power mid-infrared (MIR) laser with picosecond pulse bunch output. The pump laser is a linearly polarized MOPA structured all fiberized Yb fiber laser with picosecond pulse bunch output. The output from a mode-locked seed fiber laser was directed to pass through a FBG reflector via a circulator to narrow the pulse duration from 800 ps to less than 50 ps and the spectral FWHM from 9 nm to 0.15 nm. The narrowed pulses were further directed to pass through a novel pulse multiplier through which each pulse was made to become a pulse bunch composing of 13 sub-pulses with pulse to pulse time interval of 1.26 ns. The pulses were then amplified via two stage Yb fiber amplifiers to obtain a linearly polarized high average power output up to 85 W, which were then directed to pass through an isolator and to pump a PPMgLN-based optical parametric oscillator via quasi-synchronization pump scheme for ps pulse bunch MIR output. High MIR output with average power up to 4 W was obtained at 3.45 micron showing the feasibility of such pump scheme for ps pulse bunch MIR output. PMID:24150378

  6. Power scaling of diode-pumped neodymium yttrium aluminum borate laser

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid

    1991-01-01

    Preliminary results are presented of the efficient diode-pumped operation of a neodymium yttrium aluminum borate (NYAB) laser at 531.5 nm using two 1-W diode-laser arrays for the pump. With 1380 mW of CW power incident on the crystal, as much as 51 mW of 532.5-nm laser radiation was obtained with the unoptimized cavity. The corresponding optical-to-optical conversion efficiency was 3.7 percent. A plot of the output 531.5 nm vs incident 807 nm pump power is shown. The crystal output power was critically dependent on the rotational and translational adjustment of the NYAB crystal inside the cavity. It is suggested that a crystal cut at the exact phase matching angle, placed in a cavity with proper optimal reflection and transmission mirror coatings, and pumped at proper wavelength can result in higher output power. Thus, the NYAB output power approaches that of a CW intracavity frequency doubled Nd:YAG laser.

  7. Effects of atmospheric transmission of high power diode pumped alkali lasers

    NASA Astrophysics Data System (ADS)

    Rice, Christopher A.; Perram, Glen P.

    2013-03-01

    As diode pumped alkali lasers (DPAL) are scaled to powers exceeding 1 kW, the effects of atmospheric transmission, including thermal blooming, is explored. The cesium and rubidium lasers operate near 894 and 795 nm, respectively, in the vicinity of atmospheric water vapor absorption lines. The potassium laser line lies in the high rotational limit of the O2 X-b (0,0) band near 770 nm. We assess the effects of atmospheric transmission on high power propagation using the High Energy Laser End-to End Operational Simulation. HELEEOS uses the scaling laws of the Scaling the High energy laser And Relay Engagements (SHaRE) toolbox which is anchored to the wave optics code WaveTrain and all significant degradation effects, including thermal blooming due to molecular and aerosol absorption, scattering extinction, and optical turbulence, are represented in the model. The HELEEOS model enables the evaluation of uncertainty in low-altitude high energy laser engagements due to all major low altitude atmospheric effects to include physically-based representations of water clouds, fog, light rain, and aerosols. Worldwide seasonal, diurnal, and geographical spatial-temporal variability in key climatological parameters is organized into probability density function databases in HELEEOS using a variety of recently available resources to include the Extreme and Percentile Environmental Reference Tables (ExPERT) for 408 sites worldwide, the Surface Marine Gridded Climatology (SMGC) database which provides coverage over all ocean areas, the Master Database for Optical Turbulence Research in support of the Airborne Laser, and the Global Aerosol Data Set (GADS) used to provide worldwide aerosol densities. The spectral transmission model is anchored to field data from an open-path Tunable Diode Laser Absorption (TDLAS) system composed of narrow band (~300 kHz) diode laser fiber coupled to a 12" Ritchey-Chrétien transmit telescope. The ruggedized system has been field deployed and tested

  8. Pumping power considerations in the designs of NASA-Redox flow cells

    NASA Technical Reports Server (NTRS)

    Hoberecht, M. A.

    1981-01-01

    Pressure drop data for six different cell geometries of various flow port, manifold, and cavity dimensions are presented. The redox/energy/storage system uses two fully soluble redox couples as anode and cathode fluids. Both fluids are pumped through a redox cell, or stack of cells, where the electrochemical reactions take place at porous carbon felt electrodes. Pressure drop losses are therefore associated with this system due to the continuous flow of reactant solutions. The exact pressure drop within a redox flow cell is directly dependent on the flow rate as well as the various cell dimensions. Pumping power requirements for a specific set of cell operating conditions are found for various cell geometries once the flow rate and pressure drop are determined. These pumping power requirements contribute to the overall system parasitic energy losses which must be minimized, the choice of cell geometry becomes critical.

  9. Effect of thermal management on the properties of saturable absorber mirrors in high-power mode-locked semiconductor disk lasers

    SciTech Connect

    Rantamaeki, Antti; Lyytikaeinen, Jari; Jari Nikkinen; Okhotnikov, Oleg G

    2011-09-30

    The thermal management of saturable absorbers is shown to have a critical impact on a high-power mode-locked disk laser. The absorber with efficient heat removal makes it possible to generate ultrashort pulses with high repetition rates and high power density.

  10. Lasant Materials for Blackbody-Pumped Lasers

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J. (Editor); Chen, K. Y. (Editor)

    1985-01-01

    Blackbody-pumped solar lasers are proposed to convert sunlight into laser power to provide future space power and propulsion needs. There are two classes of blackbody-pumped lasers. The direct cavity-pumped system in which the lasant molecule is vibrationally excited by the absorption of blackbody radiation and laser, all within the blackbody cavity. The other system is the transfer blackbody-pumped laser in which an absorbing molecule is first excited within the blackbody cavity, then transferred into a laser cavity when an appropriate lasant molecule is mixed. Collisional transfer of vibrational excitation from the absorbing to the lasing molecule results in laser emission. A workshop was held at NASA Langley Research Center to investigate new lasant materials for both of these blackbody systems. Emphasis was placed on the physics of molecular systems which would be appropriate for blackbody-pumped lasers.

  11. High power 2 {mu}m diode-pumped Tm:YAG laser

    SciTech Connect

    Beach, R.J.; Sutton, S.B.; Honea, E.C.; Skidmore, J.A.; Emanuel, M.A.

    1996-01-01

    Using a scaleable diode end-pumping technology developed at LLNL, we have demonstrated a compact Tm:YAG laser capable of generating more than 50 W of cw 2 {mu}m laser output power. The design and operational characteristics of this laser, which was built originally for use in assessing laser surgical techniques, are discussed.

  12. High power 2 {micro}m wing-pumped Tm{sup 3+}:YAG laser

    SciTech Connect

    Beach, R.J.; Sutton, S.B.; Honea, E.C.; Skidmore, J.A.; Emanuel, M.A.

    1996-01-01

    Using a scalable diode end-pumping technology developed at Lawrence Livermore National Laboratory the authors have demonstrated a compact Tm{sup 3+}:YAG laser capable of generating greater than 50 W of cw 2 {micro}m laser output power. The design and operational characteristics of this laser will be discussed.

  13. High power, high efficiency, 2D laser diode arrays for pumping solid state lasers

    SciTech Connect

    Rosenberg, A.; McShea, J.C.; Bogdan, A.R.; Petheram, J.C.; Rosen, A.

    1987-11-01

    This document reports the current performance of 2D laser diode arrays operating at 770 nm and 808 nm for pumping promethium and neodymium solid state lasers, respectively. Typical power densities are in excess of 2kw/cm/sup 2/ with overall efficiencies greater than 30%.

  14. Pressure drop and pumping power for fluid flow through round tubes

    NASA Technical Reports Server (NTRS)

    Jelinek, D.

    1973-01-01

    Program, written for Hewlett-Packard 9100A electronic desk computer provides convenient and immediate solution to problem of calculating pressure drop and fluid pumping power for flow through round tubes. Program was designed specifically for steady-state analysis and assumes laminar flow.

  15. Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Upper Volta

    NASA Technical Reports Server (NTRS)

    Martz, J. E.; Ratajczak, A. F.; Delombard, R.

    1982-01-01

    The first two years of operation of a stand alone photovoltaic (PV) power system for the village of Tangaye, Upper Volta in West Africa are described. The purpose of the experiment was to demonstrate that PV systems could provide reliable electrical power for multiple use applications in remote areas where local technical expertise is limited. The 1.8 kW (peak) power system supplies 120-V (d.c.) electrical power to operate a grain mill, a water pump, and mill building lights for the village. The system was initially sized to pump a part of the village water requirements from an existing improved well, and to meet a portion of the village grain grinding requirements. The data, observations, experiences, and conclusions developed during the first two years of operation are discussed. Reports of tests of the mills used in the project are included.

  16. High-power 1018 nm ytterbium-doped fiber laser and its application in tandem pump.

    PubMed

    Xiao, Hu; Leng, Jinyong; Zhang, Hanwei; Huang, Liangjin; Xu, Jiangming; Zhou, Pu

    2015-09-20

    In this paper, we present our experimental results of a high-power 1018 nm fiber laser and its usage in tandem pump. A record output power of 476 W 1018 nm fiber laser is obtained with an efficiency of 78.2%. Utilizing a specially designed gain fiber, a one-stage high-power monolithic fiber amplifier tandem pumped by six 1018 nm fiber lasers is assembled. A 110 W 1090 nm seed is amplified to 2140 W, and the efficiency is as high as 86.9%. The beam quality factor M2 is measured to be 1.9. Limitations and possible solutions for purchasing higher output power are discussed. PMID:26406520

  17. Picosecond fiber MOPA pumped supercontinuum source with 39 W output power.

    PubMed

    Chen, Kang Kang; Alam, Shaif-Ul; Price, Jonathan H V; Hayes, John R; Lin, Dejiao; Malinowski, Andrew; Codemard, Christophe; Ghosh, Debashri; Pal, Mrinmay; Bhadra, Shyamal K; Richardson, David J

    2010-03-15

    We report a picosecond fiber MOPA pumped supercontinuum source with 39 W output, spanning at least 0.4-2.25 microm at a repetition rate of 114.8 MHz. The 2m long PCF had a large, 4.4 microm diameter core and a high-delta design which led to an 80% coupling efficiency, high damage threshold and rapid generation of visible continuum generation from the picosecond input pulses. The high and relatively uniform power density across the visible spectral region was approximately 31.7 mW/nm corresponding to peak power density of approximately 12.5 W/nm for the 21 ps input pulses. The peak power density was increased to 26.9 W/nm by reducing the repetition rate to 28 MHz. This represents an increase in both average and peak power compared to previously reported visible supercontinuum sources from either CW pumped or pulsed-systems. PMID:20389559

  18. Power scaling of resonantly pumped Yb-free Er-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Dubinskii, M.; Zhang, J.; Ter-Mikirtychev, V.

    2009-05-01

    Even though Yb-doped fiber lasers are known to be the most powerful and most efficient among all fiber lasers, recent successes in the eye-safe ~1.5μm Yb-Er-doped fiber lasers (where Er is excited through Yb-Er energy transfer) are quite impressive. Output power of Yb-Er fiber lasers reached ~300 W level and their optical-to-optical efficiency, for somewhat lower power levels, is exceeding 40% [2]. Nevertheless, as far as real eye safety is concerned, multi-hundred Watt Yb-Er fiber lasers typically carry in their output a significant fraction of competing 1-μm Yb emission, which totally compromises an eye-safe side of the application. Ultimate efficiency and thermal management of Yb-Er approach are also suffering due to: (i), inefficiency of Yb-Er energy transfer and, (ii), gigantic ~40% quantum defect of Er-doped fiber pumped at 9XX-nm. Presented here are very recent and successful results on power scaling of resonantly pumped Yb-free Er-doped fiber lasers and amplifiers. We are reporting an Ybfree Er-doped cladding-pumped fiber power scaling to ~50 W with ~57% optical-tooptical efficiency [6] in a few first experimental steps. This is clear manifestation of scaling potential of this most efficient approach to high power eye-safe fiber laser. The only competing approach to scalable eye-safe fiber laser implements Tm3+-doped fibers pumped at ~790 nm while relying on well known "2-for-1" process leading to quite efficient excitation of the ~2μm Tm3+ laser operation [4]. This approach has operational optical-to-optical efficiency quantum limit of ~75% [4], while resonantly pumped Ybfree Er-doped fiber laser's optical-to-optical efficiency quantum limit exceeds 95% due to its low-quantum-defect (QD) pump-lase scheme. Significant scaling potential of resonantly-pumped Yb-free Er-doped fiber lasers and amplifiers sets a path to an eye-safe fiber laser concept with drastically relaxed thermal management and nearly diffraction limited beam quality at ~kW-=-class power

  19. High power tube solid-state laser with zigzag propagation of pump and laser beam

    NASA Astrophysics Data System (ADS)

    Savich, Michael

    2015-02-01

    A novel resonator and pumping design with zigzag propagation of pumping and laser beams permits to design an improved tube Solid State Laser (SSL), solving the problem of short absorption path to produce a high power laser beam (100 - 1000kW). The novel design provides an amplifier module and laser oscillator. The tube-shaped SSL includes a gain element fiber-optically coupled to a pumping source. The fiber optic coupling facilitates light entry at compound Brewster's angle of incidence into the laser gain element and uses internal reflection to follow a "zigzag" path in a generally spiral direction along the length of the tube. Optics are arranged for zigzag propagation of the laser beam, while the cryogenic cooling system is traditional. The novel method of lasing uses advantages of cylindrical geometry to reach the high volume of gain medium with compactness and structural rigidity, attain high pump density and uniformity, and reach a low threshold without excessive increase of the temperature of the crystal. The design minimizes thermal lensing and stress effects, and provides high gain amplification, high power extraction from lasing medium, high pumping and lasing efficiency and a high beam quality.

  20. High-Efficiency 894-nm Laser Emission of Laser-Diode-Bar-Pumped Cesium-Vapor Laser

    NASA Astrophysics Data System (ADS)

    Zheng, Yujin; Niigaki, Minoru; Miyajima, Hirofumi; Hiruma, Teruo; Kan, Hirofumi

    2009-03-01

    We report a high-efficiency cesium-vapor laser with a high-gas-pressure (˜3-atm helium and 0.49-atm ethane) cell pumped by a high-power external-cavity laser-diode bar. Peak laser power of 12.1 W at 894 nm was obtained, when the absorbed peak pump power was 23.1 W. The achieved slope efficiencies with the incident pump power and the absorbed pump power were 33 and 81.7%, respectively.

  1. Power scaling of a side-pumped Nd:YLF laser based on DBMC technology

    NASA Astrophysics Data System (ADS)

    Wetter, Niklaus U.; Deana, Alessandro M.

    2014-12-01

    This work demonstrates the power scalability of double-beam-mode controlling, a technique that has generated the highest optical efficiency reported so far for Nd:YLF lasers. We analyze two types of power scaling possibilities by numerical simulations: multiplication of intracavity pump modules and MOPA configuration. About 44 W of TEM00 output power at 1053 nm was experimentally demonstrated with a beam-parameter product of 1.07 × 1.15. The results show great ease of power scaling without sacrificing beam quality.

  2. A dual mode charge pump with adaptive output used in a class G audio power amplifier

    NASA Astrophysics Data System (ADS)

    Yong, Feng; Zhenfei, Peng; Shanshan, Yang; Zhiliang, Hong; Yang, Liu

    2011-04-01

    A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% @ 0.5x mode and 83.6% @ 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.

  3. Low-NA fiber laser pumps powered by high-brightness single emitters

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Fiber laser manufacturers demand high-brightness laser diode pumps delivering optical pump energy in both a compact fiber core and narrow angular content. A pump delivery fiber of a 105 μm core and 0.22 numerical aperture (NA) is typically used, where the fiber NA is under-filled to ease the launch of laser diode emission into the fiber and make the fiber tolerant to bending. At SCD, we have developed high-brightness NEON multi-emitter fiber-coupled pump modules that deliver 50 W output from a 105 μm, 0.15 NA fiber enabling low-NA power delivery to a customer's fiber laser network. Brightness-enhanced single emitters are engineered with ultra-low divergence for compatibility with the low-NA delivery fiber, with the latest emitters delivering 14 W with 95% of the slow-axis energy contained within an NA of 0.09. The reduced slow-axis divergence is achieved with an optimized epitaxial design, where the peak optical intensity is reduced to both lessen filamentation within the laser cavity and reduce the power density on the output facet thus increasing the emitter reliability. The low mode filling of the fiber allows it to be coiled with diameters down to 70 mm at full operating power despite the small NA and further eliminates the need for mode-stripping at fiber combiners and splices downstream from our pump modules. 50W fiber pump products at 915, 950 and 975 nm wavelengths are presented, including a wavelengthstabilized version at 976 nm.

  4. Photoexcited broadband blueshift tunable perfect terahertz metamaterial absorber

    NASA Astrophysics Data System (ADS)

    Xu, Zong-Cheng; Gao, Run-Mei; Ding, Chun-Feng; Wu, Liang; Zhang, Ya-Ting; Yao, Jian-Quan

    2015-04-01

    We present an demonstration of optically tunable metamaterial absorber at terahertz frequencies. The metamaterials are based on two split ring resonators (SSRs) that can be tuned by integrating photoconductive silicon into the metamaterial unit cell. Filing the gap between the resonator arm with a semiconductor (silicon), leads to easy modification of its optical response through a pump beam which changes conductivity of Si. The conductivity of silicon is a function of incident pump power. Therefore, the conductivity of silicon is tuned effectively by applying an external pump power. We demonstrate that a blueshift of the resonance frequency under illumination can be accomplished and a broadband switch of absorption frequencies varying from 0.68 to 1.41 THz, with a tuning range of 51.8%. The realization of broadband blueshift tunable metamaterial absorber offers opportunities for achieving switchable metamaterial absorber and could be implemented in terahertz devices to achieve additional functionalities.

  5. Thermal damage suppression of a black phosphorus saturable absorber for high-power operation of pulsed fiber lasers.

    PubMed

    Lee, Donghyun; Park, Kichul; Debnath, Pulak C; Kim, Inho; Song, Yong-Won

    2016-09-01

    Recent studies of black phosphorus (BP) have shown its future potential in the field of photonics. We determined the optical damage threshold of BP at 21.8 dBm in a fiber ring laser cavity, and demonstrated the high-power operation capacity of an evanescent field interaction-based BP saturable absorber. The long-term stability of a passively mode-locked fiber laser with a saturable absorber operating at the optical power of 23.3 dBm was verified for 168 h without any significant performance degradation. The center wavelength, spectral width, and pulse width of the laser output are 1558.8 nm, 14.2 nm, and 805 fs, respectively. PMID:27479185

  6. Thermal damage suppression of a black phosphorus saturable absorber for high-power operation of pulsed fiber lasers

    NASA Astrophysics Data System (ADS)

    Lee, Donghyun; Park, Kichul; Debnath, Pulak C.; Kim, Inho; Song, Yong-Won

    2016-09-01

    Recent studies of black phosphorus (BP) have shown its future potential in the field of photonics. We determined the optical damage threshold of BP at 21.8 dBm in a fiber ring laser cavity, and demonstrated the high-power operation capacity of an evanescent field interaction-based BP saturable absorber. The long-term stability of a passively mode-locked fiber laser with a saturable absorber operating at the optical power of 23.3 dBm was verified for 168 h without any significant performance degradation. The center wavelength, spectral width, and pulse width of the laser output are 1558.8 nm, 14.2 nm, and 805 fs, respectively.

  7. High-power diode-directly-pumped tenth-order harmonic mode-locked TEM00 Nd:YVO4 laser with 1 GHz repetition rate

    NASA Astrophysics Data System (ADS)

    Li, F.-Q.; Zong, N.; Han, L.; Tian, C.-Y.; Bo, Y.; Peng, Q.-J.; Cui, D.-F.; Xu, Z.-Y.

    2011-02-01

    A high-efficiency high-power diode-directly-pumped tenth-order harmonic mode-locked TEM00 Nd:YVO4 laser with 1 GHz repetition rate was first demonstrated. The maximum output power was 10.4 W with optical-optical efficiency of 41.8% and slope efficiency of 78.1%, respectively, the pulse width was about 30 ps at the output power of 9.6 W. Based on the large third-order nonlinearity of Nd:YVO4, the tenth-order harmonic mode-locked pulses were induced by the intensity-dependent Kerr effect and the cooperative action of counter-propagating pulses colliding in the laser crystal for a colliding-pulse-modelocking-like cavity. The pulses were further modulated by a semiconductor saturable absorber mirror.

  8. Peak power tunable mid-infrared oscillator pumped by a high power picosecond pulsed fiber amplifier with bunch output

    NASA Astrophysics Data System (ADS)

    Wei, Kaihua; Guo, Yan; Lai, Xiaomin; Fan, Shanhui

    2016-07-01

    A high power mid-infrared optical parametric oscillator (OPO) with picosecond pulse bunch output is experimentally demonstrated. The pump source was a high power master oscillation power amplifier (MOPA) picosecond pulsed fiber amplifier. The seed of the MOPA was a gain-switched distributed Bragg reflector (DBR) laser diode (LD) with picosecond pulse operation at a high repetition rate. The seed laser was amplified to 50 W by two-stage pre-amplifiers and a large mode area (LMA) Yb fiber based power-amplifier. A fiber-pigtailed acousto-optic modulator with the first order diffraction transmission was inserted into the second pre-amplifier to form a picosecond pulse bunch train and to change the peak power simultaneously. The power-amplified pulse bunches were focused to pump a wavelength-tunable OPO for emitting high power mid-infrared laser. By adjusting the OPO cavity length, the maximum average idler powers obtained at 3.1, 3.3 and 3.5 μm were 7, 6.6 and 6.4 W respectively.

  9. Relationship between acoustic power and acoustic radiation force on absorbing and reflecting targets for spherically focusing radiators.

    PubMed

    Gélat, Pierre; Shaw, Adam

    2015-03-01

    Total acoustic output power is an important parameter required by standards for most ultrasonic medical equipment including high-intensity focused ultrasound (HIFU) systems. Radiation force balances are routinely used; however, radiation force is not strictly dependent on the ultrasound power but, rather, on the wave momentum resolved in one direction. Consequently, measurements based on radiation force become progressively less accurate as the ultrasound wave deviates further from a true plane wave. HIFU transducers can be very strongly focused with F-numbers less than one: under these conditions, the uncertainty associated with use of the radiation force method becomes very significant. International Standards IEC 61161 and IEC 62555 suggest plane-wave correction factors for unfocused transducers radiating onto an ideal absorbing target and focusing corrections for focused transducers radiating onto ideal absorbing targets and onto conical reflecting targets (IEC 61161). Previous models have relied on calculations based on the Rayleigh integral, which is not strictly correct for curved sources. In the work described here, an approach combining finite element methods with a discretization of the Helmholtz equation was developed, making it possible to model the boundary condition at the structure/fluid interface more correctly. This has been used to calculate the relationship between radiation force and total power for both absorbing and conical reflecting targets for transducers ranging from planar to an F-number of 0.5 (hemispherical) and to compare with the recommendations of IEC 61161 and IEC 62555. PMID:25683223

  10. The Stirling alternative. Power systems, refrigerants and heat pumps

    SciTech Connect

    Walker, G.; Reader, G.; Fauvel, O.R.; Bingham, E.R. )

    1993-01-01

    This book provides an up-to-date reference on the technology, history, and practical applications of Stirling engines, including recent developments in the field and a convenient survey of the Stirling engine literature. The topics of the book include: fundamentals of Stirling technology, definition and terminology, thermodynamic laws and cycles: some elementary considerations, the Stirling cycle, practical regenerative cycle, theoretical aspects and computer simulation of Stirling machines, mechanical arrangements, control systems, heat exchangers, performance characteristics, working fluids, applications of Stirling machines, advantages of Stirling machines, disadvantages of Stirling machines, Stirling versus internal combustion engines, Stirling versus Rankine engines, applications for Stirling machines, Stirling power systems, the literature and sources of supply, the literature of Stirling engines, and the literature of cryocoolers.

  11. The Effect Of Neutron Attenuation On Power Deposition In Nuclear Pumped 3He-Lasers

    NASA Astrophysics Data System (ADS)

    Çetin, Füsun

    2007-04-01

    Nuclear-pumped lasers (NPLs) are driven by the products of nuclear reactions and directly convert the nuclear energy to directed optical energy. Pumping gas lasers by nuclear reaction products has the advantage of depositing large energies per reaction. The need for high laser power output implies high operating pressure. In the case of volumetric excitation by 3He(n, p)3H reactions, however, operation at high pressure (more than a few atm) causes excessive neutron attenuation in the 3He gas. This fact adversely effects on energy deposition and, hence, laser output power and beam quality. Here, spatial and temporal variations of neutron flux inside a closed 3He -filled cylindrical laser tube have been numerically calculated for various tube radii and operating pressures by using a previously reported dynamic model for energy deposition. Calculations are made by using ITU TRIGA Mark II Reactor as the neutron source. The effects of neutron attenuation on power deposition are examined.

  12. New continuous-input current charge pump power-factor-correction electronic ballast

    SciTech Connect

    Qian, J.; Lee, F.C.; Yamauchi, Tokushi

    1999-03-01

    Continuous-input current charge pump power-factor-correction (CIC-CPPFC) electronic ballasts are proposed in this paper. The CPPFC circuit and unity power factor condition using the charge pump concept are derived and analyzed. The average lamp current control with switching frequency modulation was developed so that the low crest factor and constant lamp power operation can be achieved. The developed electronic ballast has continuous input current, so that a small line input filter can be used. The proposed CIC-CPPFC electronic ballast was implemented and tested with two 45-W fluorescent lamps. It is shown that the measured line input current harmonics satisfy IEC 1000-3-2 Class C requirements.

  13. Advances in high-power 9XXnm laser diodes for pumping fiber lasers

    NASA Astrophysics Data System (ADS)

    Skidmore, Jay; Peters, Matthew; Rossin, Victor; Guo, James; Xiao, Yan; Cheng, Jane; Shieh, Allen; Srinivasan, Raman; Singh, Jaspreet; Wei, Cailin; Duesterberg, Richard; Morehead, James J.; Zucker, Erik

    2016-03-01

    A multi-mode 9XXnm-wavelength laser diode was developed to optimize the divergence angle and reliable ex-facet power. Lasers diodes were assembled into a multi-emitter pump package that is fiber coupled via spatial and polarization multiplexing. The pump package has a 135μm diameter output fiber that leverages the same optical train and mechanical design qualified previously. Up to ~ 270W CW power at 22A is achieved at a case temperature ~ 30ºC. Power conversion efficiency is 60% (peak) that drops to 53% at 22A with little thermal roll over. Greater than 90% of the light is collected at < 0.12NA at 16A drive current that produces 3.0W/(mm-mr)2 radiance from the output fiber.

  14. The Effect Of Neutron Attenuation On Power Deposition In Nuclear Pumped 3He-Lasers

    SciTech Connect

    Cetin, Fuesun

    2007-04-23

    Nuclear-pumped lasers (NPLs) are driven by the products of nuclear reactions and directly convert the nuclear energy to directed optical energy. Pumping gas lasers by nuclear reaction products has the advantage of depositing large energies per reaction. The need for high laser power output implies high operating pressure. In the case of volumetric excitation by 3He(n, p)3H reactions, however, operation at high pressure (more than a few atm) causes excessive neutron attenuation in the 3He gas. This fact adversely effects on energy deposition and, hence, laser output power and beam quality. Here, spatial and temporal variations of neutron flux inside a closed 3He -filled cylindrical laser tube have been numerically calculated for various tube radii and operating pressures by using a previously reported dynamic model for energy deposition. Calculations are made by using ITU TRIGA Mark II Reactor as the neutron source. The effects of neutron attenuation on power deposition are examined.

  15. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power

    NASA Astrophysics Data System (ADS)

    Rezania, A.; Rosendahl, L. A.

    2012-06-01

    The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The three-dimensional governing equations for the fluid flow and the heat transfer are solved using the finite-volume method for a wide range of pressure drop laminar flows along the heat sink. The temperature and the mass flow rate distribution in the heat sink are discussed. The results, which are in good agreement with previous computational studies, show that using suggested heat sink configurations reduces the coolant pumping power in the system.

  16. High-peak-power sub-nanosecond intracavity KTiOPO4 optical parametric oscillator pumped by a dual-loss modulated laser with acousto-optic modulator and single-walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Qiao, Junpeng; Zhao, Shengzhi; Yang, Kejian; Zhao, Jia; Li, Guiqiu; Li, Dechun; Li, Tao; Qiao, Wenchao; Lu, Jianren; Wang, Yonggang; Chu, Hongwei; Luan, Chao

    2016-08-01

    A high-peak-power low-repetition-rate sub-nanosecond intracavity KTiOPO4 (KTP) optical parametric oscillator (OPO) pumped by a doubly Q-switched and mode-locked (QML) YVO4/Nd:YVO4 laser with an acousto-optic modulator (AOM) and a single-walled carbon nanotube saturable absorber (SWCNT-SA) has been demonstrated. A maximum output power of 373 mW at a signal wavelength of 1570 nm was obtained. The smallest pulse width, highest pulse energy, and greatest peak power of mode-locking pulses were estimated to be 119 ps, 124 µJ, and 1.04 MW, respectively, under a maximum incident pump power of 8.3 W and an AOM repetition rate of 2 kHz. This OPO operation paves a simple way to produce eye-safe laser sources at 1570 nm with low repetition rates, small pulse widths, and high peak powers.

  17. Generation of high-power nanosecond pulses from laser diode-pumped Nd:YAG lasers

    NASA Technical Reports Server (NTRS)

    Chan, Kinpui

    1988-01-01

    Simulation results are used to compare the pulse energy levels and pulse energy widths that can be achieved with LD-pumped Nd:YAG lasers for both the pulse-transmission mode (PTM) and pulse-reflection mode (PRM) Q-switching methods for pulse energy levels up to hundreds of microjoules and pulse widths as short as 1 ns. It is shown that high-power pulses with pulse widths as short as 1 ns can be generated with PTM Q-switched in LD-pumped Nd:YAG lasers. With the PRM Q-switching method, pulse widths as short as 2 ns and pulse energy at the level of a few hundred microjoules can also be achieved but require pumping with 8-10-mJ AlGaAs laser diode arrays.

  18. Engineering bacterial efflux pumps for solar-powered bioremediation of surface waters.

    PubMed

    Kapoor, Vikram; Wendell, David

    2013-05-01

    Antibiotics are difficult to selectively remove from surface waters by present treatment methods. Bacterial efflux pumps have evolved the ability to discriminately expel antibiotics and other noxious agents via proton and ATP driven pathways. Here, we describe light-dependent removal of antibiotics by engineering the bacterial efflux pump AcrB into a proteovesicle system. We have created a chimeric protein with the requisite proton motive force by coupling AcrB to the light-driven proton pump Delta-rhodopsin (dR) via a glycophorin A transmembrane domain. This creates a solar powered protein material capable of selectively capturing antibiotics from bulk solutions. Using environmental water and direct sunlight, our AcrB-dR vesicles removed almost twice as much antibiotic as the treatment standard, activated carbon. Altogether, the AcrB-dR system provides an effective means of extracting antibiotics from surface waters as well as potential antibiotic recovery through vesicle solubilization. PMID:23581993

  19. Testing of an Annular Linear Induction Pump for the Fission Surface Power Technology Demonstration Unit

    NASA Technical Reports Server (NTRS)

    Polzin, K. A.; Pearson, J. B.; Webster, K.; Godfoy, T. J.; Bossard, J. A.

    2013-01-01

    Results of performance testing of an annular linear induction pump that has been designed for integration into a fission surface power technology demonstration unit are presented. The pump electromagnetically pushes liquid metal (NaK) through a specially-designed apparatus that permits quantification of pump performance over a range of operating conditions. Testing was conducted for frequencies of 40, 55, and 70 Hz, liquid metal temperatures of 125, 325, and 525 C, and input voltages from 30 to 120 V. Pump performance spanned a range of flow rates from roughly 0.3 to 3.1 L/s (4.8 to 49 gpm), and pressure heads of <1 to 104 kPa (<0.15 to 15 psi). The maximum efficiency measured during testing was 5.4%. At the technology demonstration unit operating temperature of 525 C the pump operated over a narrower envelope, with flow rates from 0.3 to 2.75 L/s (4.8 to 43.6 gpm), developed pressure heads from <1 to 55 kPa (<0.15 to 8 psi), and a maximum efficiency of 3.5%. The pump was supplied with three-phase power at 40 and 55 Hz using a variable-frequency motor drive, while power at 55 and 70 Hz was supplied using a variable-frequency power supply. Measured performance of the pump at 55 Hz using either supply exhibited good quantitative agreement. For a given temperature, the peak in efficiency occurred at different flow rates as the frequency was changed, but the maximum value of efficiency was relative insensitive within 0.3% over the frequency range tested, including a scan from 45 to 78 Hz. The objectives of the FSP technology project are as follows:5 • Develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options. • Establish a nonnuclear hardware-based technical foundation for FSP design concepts to reduce overall development risk. • Reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates. • Generate the key nonnuclear products to allow Agency

  20. High-power directly diode-pumped femtosecond Yb:KGW lasers with optimized parameters

    NASA Astrophysics Data System (ADS)

    Kim, G. H.; Yang, J.; Kulik, A. V.; Sall, E. G.; Chizhov, S. A.; Yashin, V. E.; Kang, U.

    2014-02-01

    We report a diode-pumped Yb:KGW laser that is capable of operating as a Q-switched oscillator or as a regenerative amplifier with average power of more than 20 W. The laser is based on a dual-crystal configuration where the pump thermal load is distributed over relatively long two crystals. It permits a sufficiently large number of passes with low passive losses and maximizes the energy extraction efficiency. The amplification bandwidth was extended by spectral combining of two Yb:KGW crystals with spectrally shifted gain maxima, that allows to mitigate spectral gain narrowing and provides pulse length down to 200 fs after compression in a stretcher-compressor module. The output power saturated with increasing pump power and output beam quality was defined by aberration of thermal lenses. Optimization of laser cavity allows us to compensate thermal lens partially and provide output beams with quality M2<1.2. Efficient frequency doubling and tripling of high-power femtosecond Yb:KGW laser is demonstrated in a nonlinear BBO crystal. Second or third harmonic generation with respective conversion efficiency of 55% or 24% was achieved in a single-pass configuration.

  1. Power beaming to space using a nuclear reactor-pumped laser

    SciTech Connect

    Lipinski, R.J.; Monroe, D.K.; Pickard, P.S.

    1993-10-01

    The present political and environmental climate may slow the inevitable direct utilization of nuclear power in space. In the meantime, there is another approach for using nuclear energy for space power. That approach is to let nuclear energy generate a laser beam in a ground-based nuclear reactor-pumped laser (RPL), and then beam the optical energy into space. Potential space applications for a ground-based RPL include (1) illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, (2) beaming power to orbital transfer vehicles, (3) providing power (from earth) to a lunar base during the long lunar night, and (4) removing space debris. FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy with Sandia National Laboratories as the lead laboratory. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 0.585, 0.703, 0.725, 1.271, 1.733, 1.792, 2.032, 2.63, 2.65, and 3.37 {mu}m with intrinsic efficiency as high as 2.5%. Frequency-doubling the 1.733{minus}{mu}m line would yield a good match for photovoltaic arrays at 0.867 {mu}m. Preliminary designs of an RPL suitable for power beaming have been completed. The MWclass laser is fairly simple in construction, self-powered, closed-cycle (no exhaust gases), and modular. This paper describes the FALCON program accomplishments and power-beaming applications.

  2. Demonstration of a high power 1.5344 μm output Nd:YAG pumped OPO

    NASA Astrophysics Data System (ADS)

    Wojcik, Michael D.; Foltynowicz, Robert J.

    2011-03-01

    A high output power, eye-safe, lidar transmitter based on a KTA optical parametric oscillator (OPO) was demonstrated. The OPO was based on a two crystal, doubly resonant, non-critically phase-matched, KTA ring cavity. An injection seeded, 7ns, 30Hz, flashlamp-pumped, Q-switched Nd:YAG laser was used to pump the OPO. The OPO converted the 1064nm pump beam into a 1533nm signal wave and 3475nm idler wave. In addition to demonstrating a high power OPO system, we investigated the effects of seeding the pump laser on the OPO's conversion efficiency, oscillation threshold, maximum signal power, and beam quality. The power conversion efficiency between the signal and the injection seeded pump was 22% with an oscillation threshold of 104MW/cm2 (500mJ) and a maximum signal power of 6.44W (215mJ). The power conversion efficiency between the signal and the unseeded pump was 24% with an oscillation threshold of 77MW/cm2 (367mJ) and a maximum signal power of >7W (243mJ). When the pump laser was seeded, the full angle divergence improved by nearly a factor of five.

  3. Efficient 1061 and 1329 nm laser emission of Nd:CNGG lasers under 885 nm diode pumping into the emitting level

    NASA Astrophysics Data System (ADS)

    Li, Y. L.; Jiang, H. L.; Ni, T. Y.; Zhang, T. Y.; Tao, Z. H.; Zeng, Y. H.

    2011-03-01

    We report an efficiency Nd:CNGG laser operating at 1061 and 1329 nm, respectively, direct pumped by a diode laser at 885 nm for the first time to our knowledge. The maximum outputs of 4.5 and 2.9 W, at 1061 and 1329 nm, respectively, are obtained in a 6-mm-thick 0.5 at % Nd:CNGG crystal with 13.5 W of absorbed pump power at 885 nm, leading to a high slope efficiency with respect to the absorbed pump power of 32.2 and 22.1%. Under traditional pumping at 808 nm, the maximum outputs of 3.9 and 2.7 W, at 1061 and 1329 nm, respectively, are obtained with 15.4 W of absorbed pump power, corresponding to the slope efficiency with respect to the absorbed pump power of 25.2 and 17.9%.

  4. Simultaneous transient operation of a high head hydro power plant and a storage pumping station in the same hydraulic scheme

    NASA Astrophysics Data System (ADS)

    Bucur, D. M.; Dunca, G.; Cervantes, M. J.; Cǎlinoiu, C.; Isbǎşoiu, E. C.

    2014-03-01

    This paper presents an on-site experimental analysis of a high head hydro power plant and a storage pumping station, in an interconnected complex hydraulic scheme during simultaneous transient operation. The investigated hydropower site has a unique structure as the pumping station discharges the water into the hydropower plant penstock. The operation regimes were chosen for critical scenarios such as sudden load rejections of the turbines as well as start-ups and stops with different combinations of the hydraulic turbines and pumps operation. Several parameters were simultaneously measured such as the pumped water discharge, the pressure at the inlet pump section, at the outlet of the pumps and at the vane house of the hydraulic power plant surge tank. The results showed the dependence of the turbines and the pumps operation. Simultaneous operation of the turbines and the pumps is possible in safe conditions, without endangering the machines or the structures. Furthermore, simultaneous operation of the pumping station together with the hydropower plant increases the overall hydraulic efficiency of the site since shortening the discharge circuit of the pumps.

  5. Pump and Flow Control Subassembly of Thermal Control Subsystem for Photovoltaic Power Module

    NASA Technical Reports Server (NTRS)

    Motil, Brian; Santen, Mark A.

    1993-01-01

    The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.

  6. Photon pair generation from compact silicon microring resonators using microwatt-level pump powers.

    PubMed

    Savanier, Marc; Kumar, Ranjeet; Mookherjea, Shayan

    2016-02-22

    Microring resonators made from silicon are becoming a popular microscale device format for generating photon pairs at telecommunications wavelengths at room temperature. In compact devices with a footprint less than 5 × 10-4 mm2, we demonstrate pair generation using only a few microwatts of average pump power. We discuss the role played by important parameters such as the loss, group-velocity dispersion and the ring-waveguide coupling coefficient in finding the optimum operating point for silicon microring pair generation. Silicon photonics can be fabricated using deep ultraviolet lithography wafer-scale fabrication processes, which is scalable and cost-effective. Such small devices and low pump power requirements, and the side-coupled waveguide geometry which uses an integrated waveguide, could be beneficial for future scaled-up architectures where many pair-generation devices are required on the same chip. PMID:26906993

  7. Tunable excitation of mid-infrared optically pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Olafsen, Linda J.; Kunz, Jeremy; Ongstad, Andrew P.; Kaspi, Ron

    2013-01-01

    While conventional semiconductor lasers employ electrical injection for carrier excitation, optically pumped semiconductor lasers (OPSLs) have demonstrated high output powers and high brightness in the mid-infrared. An important consideration for optically pumped lasers is efficient absorption of the pump beam, which can be achieved through increasing the number of periods in the active region, by placing the active region in a cavity with an optical thickness of twice the pump wavelength between distributed Bragg reflectors (Optical Pumping Injection Cavity), or by periodically inserting the active quantum wells into an InGaAsSb waveguide designed to absorb the pump radiation (Integrated Absorber). A tunable optical pumping technique is utilized by which threshold intensities are minimized and efficiencies are maximized. The near-IR idler output of a Nd:YAG-pumped optical parametric oscillator (10 Hz, ~4 ns) is the tunable optical pumping source in this work. Results are presented for an OPSL with a type-II W active region embedded in an integrated absorber to enhance the absorption of the optical pump beam. Emission wavelengths range from 4.64 μm at 78 K to 4.82 μm at 190 K for optical pump wavelengths ranging from 1930-1950 nm. The effect of wavelength tuning is demonstrated and compared to single wavelength pumping (1940 nm) at a higher duty cycle (20- 30%). Comparisons are also made to other OPSLs, including a discussion of the characteristic temperature and high temperature performance of these devices.

  8. Application of sorption heat pumps for increasing of new power sources efficiency

    NASA Astrophysics Data System (ADS)

    Vasiliev, L.; Filatova, O.; Tsitovich, A.

    2010-07-01

    In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

  9. Perfluoro-n-hexyl iodide as gain media for high power, continuous solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Tabibi, Bagher M.; Humes, Donald H.; Weaver, Willard R.

    1990-01-01

    A comparative study of CW laser performance with n-C6F13I and n-C3F7I was performed using a 10-W solar-simulator-pumped laser system. The measured output power for n-C6F13I is near 10 W and is comparable to that of n-C3F7I. However, n-C6F13I has the advantages of easy purification and repeated use.

  10. High-power diode-pumped AlGaAs surface-emitting laser.

    PubMed

    Holm, M A; Burns, D; Cusumano, P; Ferguson, A I; Dawson, M D

    1999-09-20

    We report the development and characterization of an efficient diode-pumped surface-emitting semiconductor laser operating at approximately 870 nm. By using a semiconductor Bragg reflector stack/multiple GaAs quantum well structure, mounted within a conventional laser cavity, we achieved single transverse mode laser output powers of 153 mW. Self-tuning over a 15-nm spectral range has been obtained. PMID:18324092

  11. Tapered cladding diameter profile design for high-power tandem-pumped fiber lasers

    NASA Astrophysics Data System (ADS)

    Huang, Zhihua; Tang, Xuan; Lin, Honghuan; Wang, Jianjun

    2016-05-01

    The thermal effect has become the biggest limiting factor regarding the further power scaling of single mode fiber lasers, and it can lead to coating failure and transverse mode instability. A tapered cladding diameter profile design is proposed for the tandem-pumped fiber laser in this work, as it can smooth the temperature profile and reduce the maximum temperature rise within the fiber tremendously. The improvement in performance of the fiber design is verified by analytical and numerical results.

  12. Operation of the counter-rotating type pump-turbine unit installed in the power stabilizing system

    NASA Astrophysics Data System (ADS)

    Kanemoto, T.; Honda, H.; Kasahara, R.; Miyaji, T.

    2014-03-01

    This serial research intends to put a unique power stabilization system with a pumped storage into practical use. The pumped storage is equipped with a counter-rotating type pump-turbine unit whose operating mode can be shifted instantaneously in response to the fluctuation of power from renewable resources. This paper verifies that the system is reasonably effective to stabilize the fluctuating power. It is necessary to quickly increase the rotational speed when the operation is shifted from the turbine to the pumping modes, because the unit cannot pump-up water from a lower reservoir at a slow rotational speed while keeping gross/geodetic head constant. The maximum hydraulic efficiency at the turbine mode is close to the efficiency of the counter-rotating type hydroelectric unit designed exclusively for the turbine mode. The system is also provided for a pilot plant to be operated in the field.

  13. Diode-pumped continuous-wave and femtosecond Cr:LiCAF lasers with high average power in the near infrared, visible and near ultraviolet.

    PubMed

    Demirbas, Umit; Baali, Ilyes; Acar, Durmus Alp Emre; Leitenstorfer, Alfred

    2015-04-01

    We demonstrate continuous-wave (cw), cw frequency-doubled, cw mode-locked and Q-switched mode-locked operation of multimode diode-pumped Cr:LiCAF lasers with record average powers. Up to 2.54 W of cw output is obtained around 805 nm at an absorbed pump power of 5.5 W. Using intracavity frequency doubling with a BBO crystal, 0.9 W are generated around 402 nm, corresponding to an optical-to-optical conversion efficiency of 12%. With an intracavity birefringent tuning plate, the fundamental and frequency-doubled laser output is tuned continuously in a broad wavelength range from 745 nm to 885 nm and from 375 to 440 nm, respectively. A saturable Bragg reflector is used to initiate and sustain mode locking. In the cw mode-locked regime, the Cr:LiCAF laser produces 105-fs long pulses near 810 nm with an average power of 0.75 W. The repetition rate is 96.4 MHz, resulting in pulse energies of 7.7 nJ and peak powers of 65 kW. In Q-switched mode-locked operation, pulses with energies above 150 nJ are generated. PMID:25968727

  14. Directly solar-pumped iodine laser for beamed power transmission in space

    NASA Technical Reports Server (NTRS)

    Choi, S. H.; Meador, W. E.; Lee, J. H.

    1992-01-01

    A new approach for development of a 50-kW directly solar-pumped iodine laser (DSPIL) system as a space-based power station was made using a confocal unstable resonator (CUR). The CUR-based DSPIL has advantages, such as performance enhancement, reduction of total mass, and simplicity which alleviates the complexities inherent in the previous system, master oscillator/power amplifier (MOPA) configurations. In this design, a single CUR-based DSPIL with 50-kW output power was defined and compared to the MOPA-based DSPIL. Integration of multiple modules for power requirements more than 50-kW is physically and structurally a sound approach as compared to building a single large system. An integrated system of multiple modules can respond to various mission power requirements by combining and aiming the coherent beams at the user's receiver.

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

    SciTech Connect

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

    2012-05-31

    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 ({lambda} = 976 nm), and an output power of 7.5 W. The erbium-doped fibre amplifier efficiency reaches 32 %.

  16. Mather-type dense plasma focus as a new optical pump for short-wavelength high-power lasers

    SciTech Connect

    Fanning, J.J.; Kim, K.

    1984-04-01

    For the first time, a Mather-type dense plasma focus (MDPF) is successfully operated as an optical pump for lasers. Rhodamine-6G dye is optically pumped using the MDPF fluorescence, producing a laser pulse 1 ..mu..s in duration and more than 50 kW in output power. No optimization is attempted either of the laser cavity or of the lasing medium concentration and volume. A brief description of the experimental setup is presented, along with a summary and discussion of the results. The advantages of the present optical pump source and, in particular, their implications for the pumping of short-wavelength lasers are discussed.

  17. Maximum value of the pulse energy of a passively Q-switched laser as a function of the pump power.

    PubMed

    Li, Jianlang; Ueda, Ken-ichi; Dong, Jun; Musha, Mitsuru; Shirakawa, Akira

    2006-07-20

    The finite recovery time Ts of the bleached absorber is presented as one of the possible mechanisms accounting for the increase-maximum-decrease in pulse energy E with the pumping rate Wp in cw-pumped passively Q-switched solid-state lasers, by analytically evaluating the sign of the derivative partial differentialE/ partial differentialWP. The results show that, in the low pump regime (T>Ts, T is the interpulse period), the initial population density ni remains constant, the final population density nf decreases with Wp, and this results in a monotonic increase of E with Wp. In the high pump regime (Tpumped Yb:YAG laser passively Q switched by a Cr4+:YAG absorber is demonstrated to confirm this model. The theoretical model is also applied to the analysis of three previously reported passive Q switching solid-state [Nd:GdVO4, Nd+:LaSc3(BO3)4 (Nd+:LSB), and Nd:YAG] lasers experiments. PMID:16826274

  18. Highly efficient CW intracavity frequency-doubled Yb:YAG-LBO laser at 515 nm under 968 nm diode laser pumping

    NASA Astrophysics Data System (ADS)

    Sun, G. C.; Li, Y. D.; Zhao, M.; Chen, X. Y.; Wang, J. B.; Chen, G. B.

    2011-05-01

    We describe the output performances of the 1030 nm transition in Yb:YAG under in-band pumping with diode laser at the 968 nm wavelength. An end-pumped Yb:YAG crystal yielded 1.93 W of continuous-wave (CW) output power for 9.1 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 23.6%. Furthermore, 205 mW 515 nm green light was acquired by frequency doubling, resulting in an optical-to-optical efficiency with respect to the absorbed pump power of 2.7%. Comparative results obtained for the pump with diode laser at 940 nm are given in order to prove the advantages of the in-band pumping.

  19. Modeling and Performance Improvement of the Constant Power Regulator Systems in Variable Displacement Axial Piston Pump

    PubMed Central

    Park, Sung Hwan; Lee, Ji Min; Kim, Jong Shik

    2013-01-01

    An irregular performance of a mechanical-type constant power regulator is considered. In order to find the cause of an irregular discharge flow at the cut-off pressure area, modeling and numerical simulations are performed to observe dynamic behavior of internal parts of the constant power regulator system for a swashplate-type axial piston pump. The commercial numerical simulation software AMESim is applied to model the mechanical-type regulator with hydraulic pump and simulate the performance of it. The validity of the simulation model of the constant power regulator system is verified by comparing simulation results with experiments. In order to find the cause of the irregular performance of the mechanical-type constant power regulator system, the behavior of main components such as the spool, sleeve, and counterbalance piston is investigated using computer simulation. The shape modification of the counterbalance piston is proposed to improve the undesirable performance of the mechanical-type constant power regulator. The performance improvement is verified by computer simulation using AMESim software. PMID:24282389

  20. Pump flow estimation from pressure head and power uptake for the HeartAssist5, HeartMate II, and HeartWare VADs.

    PubMed

    Pennings, Kim A M A; Martina, Jerson R; Rodermans, Ben F M; Lahpor, Jaap R; van de Vosse, Frans N; de Mol, Bas A J M; Rutten, Marcel C M

    2013-01-01

    The use of long-term mechanical circulatory support (MCS) for heart failure by means of implanted continuous-flow left ventricular assist devices (cf-LVADs) will increase, either to enable recovery or to provide a destination therapy. The effectiveness and user-friendliness of MCS will depend on the development of near-physiologic control strategies for which accurate estimation of pump flow is essential. To provide means for the assessment of pump flow, this study presents pump models, estimating pump flow (Q(lvad)) from pump speed (n) and pressure difference across the LVAD (Δp(lvad)) or power uptake (P). The models are evaluated for the axial-flow LVADs HeartAssist5 (HA5) and HeartMate II (HMII), and for a centrifugal pump, the HeartWare (HW). For all three pumps, models estimating Q(lvad) from Δp(lvad) only is capable of describing pump behavior under static conditions. For the axial pumps, flow estimation from power uptake alone was not accurate. When assuming an increase in pump flow with increasing power uptake, low pump flows are overestimated in these pumps. Only for the HW, pump flow increased linearly with power uptake, resulting in a power-based pump model that estimates static pump flow accurately. The addition of pressure head measurements improved accuracy in the axial cf-LVAD estimation models. PMID:23820282

  1. NASA Redox cell stack shunt current, pumping power, and cell performance tradeoffs

    NASA Technical Reports Server (NTRS)

    Hagedorn, N.; Hoberecht, M. A.; Thaller, L. H.

    1982-01-01

    The NASA Redox energy storage system is under active technology development. The hardware undergoing laboratory testing is either 310 sq. cm. or 929 sq. cm. (0.33 sq. ft. or 1.0 sq. ft. per cell active area with up to 40 individual cells connected to make up a modular cell stack. This size of hardware allows rather accurate projections to be made of the shunt power/pump power tradeoffs. The modeling studies that were completed on the system concept are reviewed along with the approach of mapping the performance of Redox cells over a wide range of flow rates and depths of discharge of the Redox solutions. Methods are outlined for estimating the pumping and shunt current losses for any type of cell and stack combination. These methods are applicable to a variety of pumping options that are present with Redox systems. The results show that a fully developed Redox system has acceptable parasitic losses when using a fixed flow rate adequate to meet the worst conditions of current density and depth of discharge. These losses are reduced by about 65 percent if variable flow schedules are used. The exact value of the overall parasitics will depend on the specific system requirements of current density, voltage limits, charge, discharge time, etc.

  2. An investigation of photovoltaic powered pumps in direct solar domestic hot water systems

    SciTech Connect

    Al-Ibrahim, A.M.; Klein, S.A.; Mitchell, J.W.; Beckman, W.A.

    1996-09-01

    The performance of photovoltaic powered pumps in direct solar domestic hot water (PV-SDHW) systems has been studied. The direct PV- SDHW system employs a photovoltaic array, a separately excited DC- motor, a centrifugal pump, a thermal collector, and a storage tank. A search methodology for an optimum PV-SDHW system configuration has been proposed. A comparison is made between the long-term performance of a PV-SDHW system and a conventional SDHW system operating under three control schemes. The three schemes are: an ON-OFF flow controlled SDHW system operating at the manufacturer-recommended constant flow rate, and a linear proportional flow controlled SDHW system with the flow proportional to the solar radiation operating under an optimum proportionality. 13 refs., 6 figs.

  3. Technical advancements in submersible-pump power cable for harsh environments

    SciTech Connect

    Guzy, R.; Vandevier, J.

    1987-05-01

    In artificial-lift systems, such as electrical submersible pumps, the power cable provides the link between the surface equipment and the pumping unit. New cable designs are constantly being introduced. This paper discusses these designs and their materials. Information on a new approach to cable manufacturing and on use of downhole materials in harsh environments is also provided. This paper includes work on cable designs that incorporate a new, unique, elastomeric composition that resists rupture of jacketing materials used on downhole cables, eliminating the need for tape and braid. Cable history is also reviewed, classifying the cables by use temperatures and relative cost. Criteria for selecting materials suitable for the entire range of downhole environments are included.

  4. LD-pumped double-clad fiber single-frequency power amplifier

    NASA Astrophysics Data System (ADS)

    Sun, Wen-Feng; Yang, Su-Hui; Zhao, Chang-Ming

    2005-12-01

    Single frequency, single mode laser output from a monolithic resonator was amplified by a double-clad D-shape fiber of 4.4 meters long. When the signal laser is 200mw, up to 6.65 W single frequency laser output was obtained, slope efficiency is 30.6%. The amplifier is Yb 3+ doped glass fiber pumped by a laser diode array at 976nm with signal at 1064nm. Single frequency amplification has been proved by a Fabri-Parrot interferometer. It is shown from the experiments that the signal input has not been saturated. By increasing the input signal, amplification can be increased further under the same pumping power. Experimental results meet well with theoretical calculation.

  5. Reviews of a Diode-Pumped Alkali Laser (DPAL): a potential high powered light source

    NASA Astrophysics Data System (ADS)

    Cai, He; Wang, You; Han, Juhong; An, Guofei; Zhang, Wei; Xue, Liangping; Wang, Hongyuan; Zhou, Jie; Gao, Ming; Jiang, Zhigang

    2015-03-01

    Diode pumped alkali vapor lasers (DPALs) were first developed by in W. F. Krupke at the beginning of the 21th century. In the recent years, DPALs have been rapidly developed because of their high Stokes efficiency, good beam quality, compact size and near-infrared emission wavelengths. The Stokes efficiency of a DPAL can achieve a miraculous level as high as 95.3% for cesium (Cs), 98.1% for rubidium (Rb), and 99.6% for potassium (K), respectively. The thermal effect of a DPAL is theoretically smaller than that of a normal diode-pumped solid-state laser (DPSSL). Additionally, generated heat of a DPAL can be removed by circulating the gases inside a sealed system. Therefore, the thermal management would be relatively simple for realization of a high-powered DPAL. In the meantime, DPALs combine the advantages of both DPSSLs and normal gas lasers but evade the disadvantages of them. Generally, the collisionally broadened cross sections of both the D1 and the D2 lines for a DPAL are much larger than those for the most conventional solid-state, fiber and gas lasers. Thus, DPALs provide an outstanding potentiality for realization of high-powered laser systems. It has been shown that a DPAL is now becoming one of the most promising candidates for simultaneously achieving good beam quality and high output power. With a lot of marvelous merits, a DPAL becomes one of the most hopeful high-powered laser sources of next generation.

  6. Photovoltaic array driven adjustable speed heat pump and power system scheme for a lunar based habitat

    SciTech Connect

    Domijan, A. Jr.; Buchh, T.A.

    1998-12-01

    A high reliability power system scheme, incorporating a photovoltaic power supply and adjustable speed heat pump for life support is presented in this paper. Initial design guidelines and also a description of the state of technology available is presented herein. The power supply scheme will be used as input to an Adjustable Speed Drive (ASD) which will be driving a heat pump. A brief study of various aspects of ASDs is presented, further a summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is widely understood and accepted. Of the three most popular drive systems, namely the Induction Motor Drive, Switched Reluctance Motor Drive and Brushless DC Motor Drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The suitability of the above mentioned drive systems and control techniques for a photovoltaic array driven ASD for an aerospace application are discussed. Also discussed are several possible power system designs for a potential lunar habitat.

  7. Power scaling and wavelength tuning of diode-pumped Nd:LSO laser at 1.35 μm

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoxu; Lan, Jinglong; Lin, Zhi; Cui, Shengwei; Wang, Yi; Xu, Bin; Xu, Huiying; Cai, Zhiping; Xu, Xiaodong; Xu, Jun

    2016-08-01

    We report a power scaled laser operation of diode-pumped Nd:LSO lasers at 1.35 μm. With single-end-pumping scheme, maximum output power reaches 0.77 W at 1358.99 nm in free-running mode. By inserting an etalon, wavelength tuning can be realized with tuning range of at least 6.5 nm from 1356.95 nm to 1363.39 nm. Simultaneous dual-wavelength laser at 1331.63 and 1357.43 nm can also be generated with total output power of 0.19 W, for the first time to our knowledge. Further power scaling to 1.03 W of the 1358.99 nm laser is finally achieved by recycling the remaining pump power, which represents the highest output power so far for 1.3 μm silicate lasers.

  8. Deformation of partially pumped active mirrors for high average-power diode-pumped solid-state lasers.

    PubMed

    Albach, Daniel; LeTouzé, Geoffroy; Chanteloup, Jean-Christophe

    2011-04-25

    We discuss the deformation of a partially pumped active mirror amplifier as a free standing disk, as implemented in several laser systems. We rely on the Lucia laser project to experimentally evaluate the analytical and numerical deformation models. PMID:21643092

  9. Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Carrington, Connie K.; Walker, Wesley W.; Cole, Spencer T.; Green, Jason J. A.; Laycock, Rustin L.

    2003-01-01

    We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

  10. A 50-kW Module Power Station of Directly Solar-Pumped Iodine Laser

    NASA Technical Reports Server (NTRS)

    Choi, S. H.; Lee, J. H.; Meador, W. E.; Conway, E. J.

    1997-01-01

    The conceptual design of a 50 kW Directly Solar-Pumped Iodine Laser (DSPIL) module was developed for a space-based power station which transmits its coherent-beam power to users such as the moon, Martian rovers, or other satellites with large (greater than 25 kW) electric power requirements. Integration of multiple modules would provide an amount of power that exceeds the power of a single module by combining and directing the coherent beams to the user's receiver. The model developed for the DSPIL system conservatively predicts the laser output power (50 kW) that appears much less than the laser output (93 kW) obtained from the gain volume ratio extrapolation of experimental data. The difference in laser outputs may be attributed to reflector configurations adopted in both design and experiment. Even though the photon absorption by multiple reflections in experimental cavity setup was more efficient, the maximum secondary absorption amounts to be only 24.7 percent of the primary. However, the gain volume ratio shows 86 percent more power output than theoretical estimation that is roughly 60 percent more than the contribution by the secondary absorption. Such a difference indicates that the theoretical model adopted in the study underestimates the overall performance of the DSPIL. This fact may tolerate more flexible and radical selection of design parameters than used in this design study. The design achieves an overall specific power of approximately 5 W/kg and total mass of 10 metric tons.

  11. New transient absorption observed in the spectrum of colloidal CdSe nanoparticles pumped with high-power femtosecond pulses

    SciTech Connect

    Burda, C.; Link, S.; Green, T.C.; El-Sayed, M.A.

    1999-12-09

    The power dependence of the transient absorption spectrum of CdSe nanoparticle colloids with size distribution of 4.0 {+-} 0.4 nm diameter is studied with femtosecond pump-probe techniques. At the lowest pump laser power, the absorption bleaching (negative spectrum) characteristic of the exciton spectrum is observed with maxima at 560 and 480 nm. As the pump laser power increases, two new transient absorptions at 510 and 590 nm with unresolved fast rise (<100 fs) and long decay times ({much{underscore}gt}150 ps) are observed. The energy of each of the positive absorption is red shifted from that of the bleach bands by {approximately}120 MeV. The origin of this shift is discussed in terms of the effect of the internal electric field of the many electron-hole pairs formed within the quantum dot at the high pump intensity, absorption from a metastable excited state or the formation of biexcitons.

  12. Stabilization and power scaling of cladding pumped Er:Yb-codoped fiber amplifier via auxiliary signal at 1064 nm.

    PubMed

    Kuhn, Vincent; Wessels, Peter; Neumann, Jörg; Kracht, Dietmar

    2009-09-28

    To the best of our knowledge we report for the first time on an Yb-sensitized Er-doped cladding pumped fiber amplifier which is simultaneously seeded by two single-frequency lasers operating at 1556 nm and 1064 nm, respectively. This mode of operation ensures stable amplifier operation by reducing the gain around 1 microm wavelength to the large signal gain value, while having no significant effect on the slope efficiency of the amplification process at 1556 nm when pumping at 976 nm. We were able to demonstrate stable output power of 8.7 W at 1556 nm with an amplifier gain of > 22 dB, a co-propagating pumping scheme and the power limitation only being set by the available amount of pump power. PMID:19907621

  13. Power deposition in volumetric /U-235/F6-He fission-pumped nuclear lasers

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Deyoung, R. J.

    1978-01-01

    The power deposition in (U-235)F6-He fission-pumped nuclear lasers is studied. Specifically, means to maximize the energy density in the He gas are assessed. Primary loss mechanisms are identified as the fission-fragment transport to the laser-cell wall and UF6 gas excitation. The losses are thus strongly dependent on UF6 concentration. It is found that maximum power will be deposited in a laser tube when the tube radius is as large as the range of fission fragments. Experimental results indicate that when the tube radius equals the fission-fragment range, the ratio of a UF6 partial pressure to total pressure is 0.15, and the UF6-He mixing ratio is 1:6, maximum power will be deposited.

  14. Diode-pumped CW frequency-doubled Nd:GSAG-LBO blue laser at 471 nm

    NASA Astrophysics Data System (ADS)

    Li, Y. L.; Jiang, H. L.; Ni, T. Y.; Zhang, T. Y.; Tao, Z. H.; Zeng, Y. H.

    2011-04-01

    We describe the output performances of the 942 nm 4F3/2 → 4I9/2 transition in Nd:GSAG under diode-laser pumping. An end-pumped Nd:GSAG crystal yielded 3.7 W of continuous-wave output power for 17.8 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 23.4%. Furthermore, with 17.8 W of diode pump power and the frequency-doubling crystal LiB3O5 (LBO), a maximum output power of 572 mW in the blue spectral range at 471 nm has been achieved, corresponding to an optical-to-optical conversion efficiency of 3.2%; the output power stability over 4 h is better than 4.1%.

  15. Diode-pumped quasi-three-level Nd:CLNGG laser at 928 nm

    NASA Astrophysics Data System (ADS)

    Li, Y. L.; Jiang, H. L.; Ni, T. Y.; Zhang, T. Y.; Tao, Z. H.; Zeng, Y. H.

    2011-04-01

    We describe the output performances of the 928 nm 4 F 3/2 → 4 I 9/2 transition in Nd:CLNGG under diode-laser pumping. An end-pumped Nd:CLNGG crystal yielded 1.3 W of continuous-wave output power for 17.8 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 11.2%. Furthermore, with 17.8 W of diode pump power and the frequency-doubling crystal LiB3O5 (LBO), a maximum output power of 260 mW in the blue spectral range at 464 nm has been achieved. The blue output power stability over 4 h is better than 3.2%.

  16. High power 355 nm diode-pumped solid-state laser

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Cheng, Chee Yuen; Peng, Xiaoyuan; Yong, Saw Soon

    2015-07-01

    This paper reported a high-power diode-pumped solid-state laser for material processing applications with a target of more than 60 ns pulse width at 355 nm. As known, long pulse width IR laser (around 70-100 ns) is difficult to get high conversion efficiency to UV since the peak power is more than 2 times lower than 20-30 ns laser. However, the unique long pulse width characteristic makes the laser an ideal tool for flexible PCB drilling with 30-50 μm holes and for cutting portable devices. Up to 52.2% IR to UV conversion efficiency was obtained by our novel intra-cavity harmonic generation cavity design. A 9.3W UV output at 30 kHz was demonstrated with compact intra-cavity sum frequency design. Special conduction cooling-designed LD side-pumped module provided 17.8 W fundamental IR output power with AOM q-switching. The UV output pulse width is 76 ns at 30 kHz and 140 ns at 70 kHz. The type I and type II phase matching LBOs were used for intra-cavity harmonic generations of 355 nm. The output characteristics of the IR and the harmonic generations varying with the pulse repetition rate were also investigated. The experimental results are in agreement with the theoretical modelling. This system will also be useful for many material processing applications such as PCB cutting and wafer scribing.

  17. Application of Annular Linear Induction Pumps Technology for Waste Heat Rejection and Power Conversion

    SciTech Connect

    Adkins, Harold E.

    2005-03-16

    The U.S.-sponsored Jupiter Icy Moons Orbiter (JIMO) program will require a light weight, efficient, and reliable power generation system capable of a 20+ year lifespan. This requirement has renewed interest in orbiter technological development. Sub-components of the orbiter system are the primary and secondary power conversion/heat rejection systems for both the proposed nuclear reactors and Brayton cycle heat engines. Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. The conversion/rejection systems for these components typically utilize pumped molten metal as the heat transfer medium. Electromagnetic (EM) Annular Linear Induction Pumps (ALIPs) are ideal for this purpose as they can operate at moderate to high efficiency, at elevated temperature, do not involve moving parts (solid-state; long life), and require no bearings or seals. A parametric study was performed to develop a suite of ALIP preliminary designs capable of providing specified pressure and mass flow rate ranges for the proposed NaK(78) Brayton-cycle heat rejection loop. A limited study was also performed for the proposed lithium-cooled nuclear reactor heat transport loops; however, the design of these units is still in its infancy. Both studies were conducted by Pacific Northwest National Laboratory (PNNL) with the MHD Systems’ ALIP Design Code. The studies focused on designing ALIPs that displayed reasonably high efficiency and low source voltages as well as low mass and smallest geometric envelope.

  18. Performance Testing of a Liquid Metal Pump for In-Space Power Systems

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt

    2011-01-01

    Fission surface power (FSP) systems could be used to provide power on the surface of the moon, Mars, or other planets and moons of our solar system. Fission power systems could provide excellent performance at any location, including those near the poles or other permanently shaded regions, and offer the capability to provide on demand power at any time, even at large distances from the sun. Fission-based systems also offer the potential for outposts, crew and science instruments to operate in a power-rich environment. NASA has been exploring technologies with the goal of reducing the cost and technical risk of employing FSP systems. A reference 40 kWe option has been devised that is cost-competitive with alternatives while providing more power for less mass anywhere on the lunar surface. The reference FSP system is also readily extensible for use on Mars, where it would be capable of operating through global dust storms and providing year-round power at any Martian latitude. Detailed development of the FSP concept and the reference mission are documented in various other reports. The development discussed in this paper prepares the way for testing of the Technology Demonstration Unit (TDU), which is a 10 kWe end-to-end test of FSP technologies intended to raise the entire FSP system to technology readiness level (TRL) 6. The Early Flight Fission Test Facility (EFF-TF) was established by NASA s Marshall Space Flight Center (MSFC) to provide a capability for performing hardware-directed activities to support multiple in-space nuclear reactor concepts by using a nonnuclear test methodology. This includes fabrication and testing at both the module/component level and at near prototypic reactor components and configurations allowing for realistic thermal-hydraulic evaluations of systems. The liquid-metal pump associated with the FSP system must be compatible with the liquid NaK coolant and have adequate performance to enable a viable flight system. Idaho National

  19. A practical approach for implementing risk-based inservice testing of pumps at nuclear power plants

    SciTech Connect

    Hartley, R.S.; Maret, D.; Seniuk, P.; Smith, L.

    1996-12-01

    The American Society of Mechanical Engineers (ASME) Center for Research and Technology Development`s (CRTD) Research Task Force on Risk-Based Inservice Testing has developed guidelines for risk-based inservice testing (IST) of pumps and valves. These guidelines are intended to help the ASME Operation and Maintenance (OM) Committee to enhance plant safety while focussing appropriate testing resources on critical components. This paper describes a practical approach for implementing those guidelines for pumps at nuclear power plants. The approach, as described in this paper, relies on input, direction, and assistance from several entities such as the ASME Code Committees, United States Nuclear Regulatory Commission (NRC), and the National Laboratories, as well as industry groups and personnel with applicable expertise. Key parts of the risk-based IST process that are addressed here include: identification of important failure modes, identification of significant failure causes, assessing the effectiveness of testing and maintenance activities, development of alternative testing and maintenance strategies, and assessing the effectiveness of alternative testing strategies with present ASME Code requirements. Finally, the paper suggests a method of implementing this process into the ASME OM Code for pump testing.

  20. Spin-lattice relaxation and the calculation of gain, pump power, and noise temperature in ruby

    NASA Technical Reports Server (NTRS)

    Lyons, J. R.

    1989-01-01

    The use of a quantitative analysis of the dominant source of relaxation in ruby spin systems to make predictions of key maser amplifier parameters is described. The spin-lattice Hamiltonian which describes the interaction of the electron spins with the thermal vibrations of the surrounding lattice is obtained from the literature. Taking into account the vibrational anisotropy of ruby, Fermi's rule is used to calculate the spin transition rates between the maser energy levels. The spin population rate equations are solved for the spin transition relaxation times, and a comparison with previous calculations is made. Predictions of ruby gain, inversion ratio, and noise temperature as a function of physical temperature are made for 8.4-GHz and 32-GHz maser pumping schemes. The theory predicts that ruby oriented at 90 deg will have approximately 50 percent higher gain in dB and slightly lower noise temperature than a 54.7-deg ruby at 32 GHz (assuming pump saturation). A specific calculation relating pump power to inversion ratio is given for a single channel of the 32-GHz reflected wave maser.

  1. Fish and opossum shrimp entrainment in the Mt. Elbert Pumped-Storage Power Plant

    SciTech Connect

    Maiolie, M.A.

    1987-01-01

    Impacts of operating the Mt. Elbert Pumped-Storage Power Plant on fish and opossum shrimp (mysis relicta) were investigated from 1981 to 1985 at Twin Lakes, Colorado to determine any negative effects on the Twin Lakes fishery. Daytime generation cycles entrained shrimp at densities averaging 0.05 to 0.23 shrimp/m/sup 3/ of discharge. Eight hour daytime generation cycles would entrain 50,000 to 300,000 shrimp at these rates. Generation cycles which occurred after dark entrained many times more shrimp with densities as high as 1.21 shrimp/m/sup 3/ of discharge. Entrainment density during nighttime pump-back cycles was much greater; averaging 2 to 17 shrimp/m/sup 3/ discharged. Six to 44 million shrimp were entrained during typical 8 h pump-back cycles. Differences between daytime and nighttime entrainment rates appeared to be caused by migration of shrimp into the water column at night making them more vulnerable to entrainment. Losses were estimated to have reduced Lower Twin Lake shrimp abundance by 39% in 1985.

  2. SBS of repetitively pulsed radiation and possibility of increasing of the pump average power

    SciTech Connect

    Andreev, N.; Kulagin, O.; Palashov, O.; Pasmanik, G.; Rodchenkov, V.

    1995-12-31

    The features of liquid purification from molecular and dispersive admixtures are studied. The analysis has revealed the processes (thermal effects, microparticles heating with a subsequent optical breakdown, Stimulated Raman Scattering) limiting pumping pulse energy. These effects complicate also a realization of a high quality phase conjugation at SBS. The data concerning physical properties of liquid tetrachlorides and freons are presented. The picture of a behavior of liquid under conditions of an optical breakdown is described. Some recommendations regarding a choice of nonlinear media are formulated. The two-cell scheme providing a phase conjugation of powerful short laser pulses is proposed. This is important in the field of inertial confinement fusion.

  3. High-efficiency diode-pumped femtosecond Yb:YAG ceramic laser.

    PubMed

    Zhou, Binbin; Wei, Zhiyi; Zou, Yuwan; Zhang, Yongdong; Zhong, Xin; Bourdet, G L; Wang, Junli

    2010-02-01

    A highly efficient diode-end-pumped femtosecond Yb:yttrium aluminum garnet (YAG) ceramic laser was demonstrated. Pumped by a 968 nm fiber-coupled diode laser, 1.9 W mode-locked output power at a repetition rate of 64.27 MHz was obtained with 3.5 W absorbed pump power, corresponding to a slope efficiency of 76%. Our measurement showed that the pulse duration was 418 fs with the central wavelength of 1048 nm. PMID:20125697

  4. Generation of a periodic sequence of powerful ultrashort pulses in a traveling wave tube with bleachable absorber in the feedback loop

    NASA Astrophysics Data System (ADS)

    Ginzburg, N. S.; Denisov, G. G.; Vilkov, M. N.; Zotova, I. V.; Sergeev, A. S.

    2015-09-01

    It is shown that a periodic series of ultrashort pulses can be formed in electron microwave generators with a bleachable absorber in the feedback loop. The peak power of such radiation is considerably higher than radiation power in stationary modes. The pulsed generation method is analogous to the method of passive synchronization of waves, which is widely used in laser physics.

  5. QCW diode-side-pumped Nd:YAG ceramic laser with 247 W output power at 1123 nm

    NASA Astrophysics Data System (ADS)

    Li, C. Y.; Peng, Q. J.; Wang, B. S.; Bo, Y.; Cui, D. F.; Xu, Z. Y.; Feng, X. Q.; Pan, Y. B.

    2011-05-01

    We demonstrate for the first time a diode-side-pumped quasi-continuous-wave (QCW) operation of a 1123 nm Nd:YAG ceramic laser. The single 1123 nm wavelength is acquired through precise coating. With a pump power of 1000 W, an output power of 247 W is obtained, corresponding to an optical-optical conversion efficiency of 24.7%. At the maximal output power, the pulse repetition rate and pulse width are measured to be 1.1 kHz and 180 μs, respectively. The numerical simulations for wavelength selectivity from 1112, 1116 and 1123 nm are discussed in detail.

  6. High-power passively mode-locked Nd:YVO(4) laser using SWCNT saturable absorber fabricated by dip coating method.

    PubMed

    Tang, Chun Yin; Chai, Yang; Long, Hui; Tao, Lili; Zeng, Long Hui; Tsang, Yuen Hong; Zhang, Ling; Lin, Xuechun

    2015-02-23

    Passive mode locked laser is typically achieved by the Semiconductor Saturable absorber Mirror, SESAM, saturable absorber, which is produced by expensive and complicated metal organic chemical vapor deposition method. Carbon based single wall carbon nanotube (SWCNT), saturable absorber, is a promising material which is capable to produce stable passive mode-locking in the high power laser cavity over a wide operational wavelength range. This study has successfully demonstrated the high power mode locking laser system operating at 1 micron by using SWCNT based absorbers fabricated by dip coating method. The proposed fabrication method is practical, simple and cost effective for fabricating SWCNT saturable absorber. The demonstrated high power Nd:YVO(4) mode-locked laser operating at 1064nm have maximum output power up to 2.7W,with the 167MHz repetition rate and 3.1 ps pulse duration, respectively. The calculated output pulse energy and peak power are 16.1nJ and 5.2kW, respectively. PMID:25836523

  7. Engineering the Implementation of Pumped Hydro Energy Storage in the Arizona Power Grid

    NASA Astrophysics Data System (ADS)

    Dixon, William Jesse J.

    This thesis addresses the issue of making an economic case for bulk energy storage in the Arizona bulk power system. Pumped hydro energy storage (PHES) is used in this study. Bulk energy storage has often been suggested for large scale electric power systems in order to levelize load (store energy when it is inexpensive [energy demand is low] and discharge energy when it is expensive [energy demand is high]). It also has the potential to provide opportunities to avoid transmission and generation expansion, and provide for generation reserve margins. As the level of renewable energy resources increases, the uncertainty and variability of wind and solar resources may be improved by bulk energy storage technologies. For this study, the MATLab software platform is used, a mathematical based modeling language, optimization solvers (specifically Gurobi), and a power flow solver (PowerWorld) are used to simulate an economic dispatch problem that includes energy storage and transmission losses. A program is created which utilizes quadratic programming to analyze various cases using a 2010 summer peak load from the Arizona portion of the Western Electricity Coordinating Council (WECC) system. Actual data from industry are used in this test bed. In this thesis, the full capabilities of Gurobi are not utilized (e.g., integer variables, binary variables). However, the formulation shown here does create a platform such that future, more sophisticated modeling may readily be incorporated. The developed software is used to assess the Arizona test bed with a low level of energy storage to study how the storage power limit effects several optimization outputs such as the system wide operating costs. Large levels of energy storage are then added to see how high level energy storage affects peak shaving, load factor, and other system applications. Finally, various constraint relaxations are made to analyze why the applications tested eventually approach a constant value. This

  8. Design of kW level picosecond compressor of pump pulses for high power OPCPA

    NASA Astrophysics Data System (ADS)

    Bakule, Pavel; Novák, Jakub; Kramer, Daniel; Strkula, Petr; Novák, Miroslav; Hřebíček, Jan; Koutris, Efstratios; Zervos, Charalampos; Baše, Radek; Batysta, František; Hubka, Zbyněk.; Green, Jonathan T.; Rus, Bedřich

    2013-05-01

    We present a design of a high average power vacuum compressor unit for 1 kHz repetition rate pump laser operating at 1030 nm. The unit comprises two compressors and two SHG units located in a common vacuum vessel. Both compressors are designed with GDD of -270.5 ps2 for compressing high energy, 1J, 500 ps pulses to 1.5 ps duration with efficiency that exceeds 88.5%. We also considered the feasibility of high efficiency, average power conversion to 515 nm in a range of nonlinear crystals in vacuum. The calculated temperature profiles in large aperture crystals are compared with temperature acceptance bandwidths for the second harmonic generation. It is concluded that in LBO and YCOB crystals the conversion efficiency can exceed 60%, thus allowing generation of 1 kHz train of 1.5 ps pulses at 515 nm with energy exceeding 0.5 J that will be used for pumping the high energy amplifier stages of a femtosecond OPCPA system.

  9. High-average-power diode-end-pumped intracavity-doubled Nd:YAG laser

    SciTech Connect

    Honea, E.C.; Ebbers, C.A.; Beach, R.J.; Speth, J.A.; Emanuel, M.S>; Skidmore, J.A.; Payne, S.A.

    1998-02-12

    A compact diode-pumped ND:YAG laser was frequency-doubled to 0.532 {mu}m with an intracavity KTP or LBO crystal using a `V` cavity configuration. Two acousto-optic Q-switches were employed at repetition rates of 10-30 kHz. Dichroic fold and end mirrors were used to output two beams with up to 140 W of 0.532 {mu}m power using KTP and 116 W using LBO as the frequency doubling crystal. This corresponds to 66% of the maximum output power at 1.064 {mu}m obtained with an optimized output coupler reflectivity. The minimum output pulse duration varied with repetition rate from 90 to 130 ns. The multimode output beam had a smooth profile and a beam quality of M{sup 2} = 5 1.

  10. The internal flow pattern analysis of a tidal power turbine operating on bidirectional generation-pumping

    NASA Astrophysics Data System (ADS)

    Y Luo, Y.; Xiao, Y. X.; Wang, Z. W.

    2013-12-01

    Using tidal energy can reduce environment pollution, save conventional energy and improve energy structure, hence it presents great advantage and is developing potential. Influenced by flood tide and low tide, a fully functional tidal power station needs to experience six operating modes, including bidirectional generation, pumping and sluice; the internal unsteady flow pattern and dynamic characters are very complicated. Based on a bidirectional tidal generator unit, three-dimensional unsteady flows in the flow path were calculated for four typical operating conditions with the pressure pulsation characteristics analyzed. According to the numerical results, the internal flow characteristics in the flow path were discussed. The influence of gravity to the hydraulic performance and flow characteristics were analysed. The results provide a theoretical analysis method of the hydraulic optimization design of the same type unit as well as a direction for stable operation and optimal scheduling of existing tidal power unit.

  11. High power resonantly diode-pumped σ-configuration Er3+:YVO4 laser at 1593.5 nm

    NASA Astrophysics Data System (ADS)

    Ter-Gabrielyan, N.; Fromzel, V.; Lukasiewicz, T.; Ryba-Romanowski, W.; Dubinskii, M.

    2011-07-01

    Laser operation of an eyesafe 1593.5-nm laser based on Er3+-doped yttrium orthovanadate single crystal resonantly-pumped by a spectrally-narrowed InGaAsP/InP diode bar stack is demonstrated for the first time. Cryogenically-cooled Er3+:YVO4 laser pumped at 1534 nm performed with maximum slope efficiency of ~ 70% and maximum quasi-continuous-wave (Q-CW) power of 59.8 W.

  12. Polarization maintaining, high-power and high-efficiency (6+1)×1 pump/signal combiner

    NASA Astrophysics Data System (ADS)

    Kopp, Victor I.; Park, Jongchul; Wlodawski, Mitchell; Singer, Jonathan; Neugroschl, Dan

    2014-03-01

    We have developed an all-glass, fusion spliceable polarization maintaining (6+1)× 1 pump/signal combiner for fiber lasers and amplifiers. We utilize an enhanced tapered fiber bundle technology for multimode pump channels and a vanishing core fiber for the single mode polarization maintaining large mode area (PLMA) signal channel. The signal channel of the combiner is optimized to match a double-clad PLMA fiber with 20 micron core and 400 micron glass cladding with 0.065 numerical aperture (NA). The multimode pump channels have 200 micron core and 240 micron cladding with NA of 0.22 designed to deliver high power 980 nm pump light. The same double-clad PLMA fiber is used as both the signal input channel and the combined output for the device. Polarization axes of the input and output PLMA fibers are aligned during the fusion splices to achieve polarization crosstalk below -20 dB. Utilizing this approach, we have achieved coupling loss of ~0.4 dB for the signal channel as measured from the input PLMA to the output PLMA at a wavelength of 1060 nm and coupling loss below 0.01 dB for all pump channels as determined from the measured temperature rise of the combiner package temperature as the optical pump power at 974 nm is increased up to 45 W. Low signal and pump losses result in high efficiency lasing or amplification at over a kW of pump power for high power applications where a single mode, high polarization extinction ratio output is required.

  13. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  14. Optimal dynamic vibration absorber design for minimizing the band-averaged input power using the residue theorem

    NASA Astrophysics Data System (ADS)

    D`Amico, R.; Koo, K.; Claeys, C. C.; Pluymers, B.; Desmet, W.

    2015-03-01

    This paper deals with an efficient strategy to improve the vibro-acoustic behavior of a structure over frequency bands. Genetic Algorithms are used to identify the optimal resonance frequency and location of Dynamic Vibration Absorbers (DVAs) which minimize the band-averaged input power into a plate, leading to an indirect reduction of the radiated acoustic power and global vibration. Instead of classic numerical quadrature schemes, the residue theorem is used to evaluate the band-averaged input power. This results into a considerable reduction of computational effort, as it requires only few function evaluations at complex frequencies, regardless of the analyzed bandwidth. The structural response is simulated by using the Wave Based Method (WBM). Besides an increased convergence rate as compared to classical element-based techniques, the WBM is also free in determining the optimal position of the DVAs, not restricting it to nodal grid locations. Moreover, when point connections are taken into account, only a small part of the WB matrices needs to be recomputed at each iteration, resulting in a strong reduction of the computation time. Numerical examples illustrate the benefits and the efficiency of the proposed optimization strategy.

  15. Analysis of mobile phone design features affecting radiofrequency power absorbed in a human head phantom.

    PubMed

    Kuehn, Sven; Kelsh, Michael A; Kuster, Niels; Sheppard, Asher R; Shum, Mona

    2013-09-01

    The US FCC mandates the testing of all mobile phones to demonstrate compliance with the rule requiring that the peak spatial SAR does not exceed the limit of 1.6 W/kg averaged over any 1 g of tissue. These test data, measured in phantoms with mobile phones operating at maximum antenna input power, permitted us to evaluate the variation in SARs across mobile phone design factors such as shape and antenna design, communication technology, and test date (over a 7-year period). Descriptive statistical summaries calculated for 850 MHz and 1900 MHz phones and ANOVA were used to evaluate the influence of the foregoing factors on SARs. Service technology accounted for the greatest variability in compliance test SARs that ranged from AMPS (highest) to CDMA, iDEN, TDMA, and GSM (lowest). However, the dominant factor for SARs during use is the time-averaged antenna input power, which may be much less than the maximum power used in testing. This factor is largely defined by the communication system; e.g., the GSM phone average output can be higher than CDMA by a factor of 100. Phone shape, antenna type, and orientation of a phone were found to be significant but only on the order of up to a factor of 2 (3 dB). The SAR in the tilt position was significantly smaller than for touch. The side of the head did not affect SAR levels significantly. Among the remaining factors, external antennae produced greater SARs than internal ones, and brick and clamshell phones produced greater SARs than slide phones. Assuming phone design and usage patterns do not change significantly over time, we have developed a normalization procedure and formula that permits reliable prediction of the relative SAR between various communication systems. This approach can be applied to improve exposure assessment in epidemiological research. PMID:23533135

  16. Coalmines as Underground Pumped Storage Power Plants (UPP) - A Contribution to a Sustainable Energy Supply?

    NASA Astrophysics Data System (ADS)

    Luick, H.; Niemann, A.; Perau, E.; Schreiber, U.

    2012-04-01

    In Europe, electrical power generation from renewable energy sources rose by about 50% in the last 20 years. In Germany, renewable electricity is mainly provided by wind power and photovoltaic. Energy output depends on weather conditions like wind speed or solar radiation and may therefore vary considerably. Rapid fluctuations in power generation already require regulation of conventional power plants by the distribution network operators to stabilize and ensure grid frequency and overall system stability. In order to avoid future blackouts caused by intermittent energy sources, it is necessary to increase the storage capacity for electric power. Theoretically, there are many technologies for storing energy, like accumulators, hydrogen storage systems, biomethane facilities (hydrocarbon synthesis) or compressed air storage. Only a few technologies combine sufficient capacity, fast response, high efficiency, low storage loss and long-term application experience. A pumped storage power plant (PSPP) is a state of the art technology which combines all of these aspects. Energy is stored in form of potential energy by pumping water to an upper reservoir in times of energy surplus or low energy costs. In times of insufficient power supply or high energy costs, the water is released through turbines to produce electric energy. The efficiency of state-of-the-art systems is about 70-80%. The total head (geodetic height between upper and lower reservoirs) and the storage capacity of the reservoirs as given in a mountainous terrain, determine the energy storage capacity of a PSPP. An alternative is the use of man-made geodetic height differences as given in ore, coal or open cast lignite mines. In these cases, the lower reservoir of the plant is located in the drifts or at the bottom of the mine. Energieforschungszentrum Niedersachsen (EFZN) has already explored the installation of a PSPP in abandoned ore mines in the Harz-region/Germany (Beck 2011). In 2011/2012 a basic

  17. Interference study of a diode-pumped Nd : GGG active disk

    SciTech Connect

    Bufetova, G A; Nikolaev, D A; Trikshev, A I; Tsvetkov, V B; Shcherbakov, Ivan A

    2011-08-31

    We present the results of interference studies of a diode-pumped active disk element made of a gadolinium - gallium - garnet (GGG:Nd) crystal. The disk is cut perpendicular to the crystallographic axis [001], along which the pump beam propagates. With absorbing pump radiation, a thermal lens, which has been investigated by the interference methods using linearly polarised probe radiation, is formed in the disk. At the absorbed pump power up to 12 W, the interference pattern near the disk surface is a system of concentric rings. With increasing absorbed pump power up to 24 W, the outer rings transform into hexagons. It is shown that such an interference pattern in the garnet crystal is caused by thermally induced birefringence. (lasers)

  18. 16.2-W average power from a diode-pumped femtosecond Yb:YAG thin disk laser.

    PubMed

    Aus der Au, J; Spühler, G J; Südmeyer, T; Paschotta, R; Hövel, R; Moser, M; Erhard, S; Karszewski, M; Giesen, A; Keller, U

    2000-06-01

    We demonstrate a power-scalable concept for high-power all-solid-state femtosecond lasers, based on passive mode locking of Yb:YAG thin disk lasers with semiconductor saturable-absorber mirrors. We obtained 16.2 W of average output power in pulses with 730-fs duration, 0.47-muJ pulse energy, and 560-kW peak power. This is to our knowledge the highest average power reported for a laser oscillator in the subpicosecond regime. Single-pass frequency doubling through a 5-mm-long lithium triborate crystal (LBO) yields 8-W average output power of 515-nm radiation. PMID:18064208

  19. Intracavity absorption with a continuous wave dye laser - Quantification for a narrowband absorber

    NASA Technical Reports Server (NTRS)

    Brobst, William D.; Allen, John E., Jr.

    1987-01-01

    An experimental investigation of the dependence of intracavity absorption on factors including transition strength, concentration, absorber path length, and pump power is presented for a CW dye laser with a narrow-band absorber (NO2). A Beer-Lambert type relationship is found over a small but useful range of these parameters. Quantitative measurement of intracavity absorption from the dye laser spectral profiles showed enhancements up to 12,000 (for pump powers near lasing threshold) when compared to extracavity measurements. The definition of an intracavity absorption coefficient allowed the determination of accurate transition strength ratios, demonstrating the reliability of the method.

  20. Femtosecond mode-locked holmium fiber laser pumped by semiconductor disk laser.

    PubMed

    Chamorovskiy, A; Marakulin, A V; Ranta, S; Tavast, M; Rautiainen, J; Leinonen, T; Kurkov, A S; Okhotnikov, O G

    2012-05-01

    We report on a 2085 nm holmium-doped silica fiber laser passively mode-locked by semiconductor saturable absorber mirror and carbon nanotube absorber. The laser, pumped by a 1.16 μm semiconductor disk laser, produces 890 femtosecond pulses with the average power of 46 mW and the repetition rate of 15.7 MHz. PMID:22555700

  1. Gain change by adjusting the pumping wavelength in an end-pumped Nd:YVO4 amplifier.

    PubMed

    Nie, Mingming; Liu, Qiang; Ji, Encai; Fu, Xing; Gong, Mali

    2016-06-20

    In this paper, the performance of an end-pumped laser amplifier was experimentally studied by adjusting the pumping wavelength of a laser diode. An interesting phenomenon was observed: that the gain would decrease with an increase in absorbed pump power. The scaled output power of 0.3 at. % doped 20 mm long Nd:YVO4 crystal decreased from 0.48 to 0.2 W when the absorbed pump power increased from 17.5 to 17.8 W. Theoretical analysis was demonstrated according to our previous model. The long crystal length is the main reason for the observed phenomenon. This phenomenon could be utilized to enhance amplifier gain and improve thermal performance, including the maximal temperature and thermal stress of the crystal. PMID:27409123

  2. High-power diode-end-pumped laser with multi-segmented Nd-doped yttrium vanadate.

    PubMed

    Huang, Y J; Chen, Y F

    2013-07-01

    A Nd:YVO4 crystal consisting of three segments with different doping concentrations is originally developed for power scaling in diode-end-pumped solid-state laser. We systematically make a comparison of laser characteristics between the multi-segmented and conventional composite crystals to show the feasibility of using gain medium with multiple doping concentrations for power scale-up in end-pumped laser without introducing significant thermally accompanied effects. We further construct a dual-end-pumped actively Q-switched oscillator at 1064 nm to verify the usefulness of our crystal design, where the largest pulse energy of 1.06 mJ and the highest output power of 45 W are efficiently generated. PMID:23842393

  3. High-efficiency high-power QCW diode-side-pumped zigzag Nd:YAG ceramic slab laser

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Liu, W.; Bo, Y.; Jiang, B.; Xu, J.; Li, J.; Xu, Y.; Pan, Y.; Xu, J. L.; Feng, X.; Guo, Y.; Shen, Y.; Yang, F.; Yuan, L.; Yuan, H.; Peng, Q.; Cui, D.; Xu, Z.

    2013-04-01

    A high-efficiency high-power diode-side-pumped quasi-continuous wave (QCW) Nd:YAG ceramic slab laser using zigzag optical path was demonstrated. With an integrating sphere technique, the scattering and absorption coefficient of the ceramic slab were measured to be 0.0024 and 0.0016 cm-1 at 1,064 nm, respectively. Under a pump power of 6.69 kW, an average output power of 2.44 kW at 1,064 nm with a repetition rate of 400 Hz was achieved, corresponding to an optical-to-optical efficiency of 36.5 %. As far as we know, this is the highest conversion efficiency reported for QCW side-pumped single slab Nd:YAG ceramic laser.

  4. High-power top-hat pulses from a Yb master oscillator power amplifier for efficient optical parametric amplifier pumping.

    PubMed

    Balčiūnas, T; Fan, G Y; Andriukaitis, G; Pugžlys, A; Baltuška, A

    2012-07-01

    We demonstrate shaping of high-energy broadband Yb amplifier pulses for the generation of a (sub)picosecond top-hat temporal pulse profile that significantly improves pumping efficiency of an optical parametric amplifier (OPA). Phase-only modulation is applied by an acousto-optic programmable dispersion filter. This simple scheme is scalable to a high average power due to a relatively broad bandwidth of the Yb:CaF(2) gain medium used in the amplifier that supports a sub-150-fs transform-limited pulse duration. Additionally we show that OPA seeding with supercontinuum remains possible because top-hat-shaped pulses passed through a glass block recompress to ≈200 fs with minimum satellite production. PMID:22743450

  5. CFD assisted simulation of temperature distribution and laser power in pulsed and CW pumped static gas DPALs

    NASA Astrophysics Data System (ADS)

    Waichman, Karol; Barmashenko, Boris D.; Rosenwaks, Salman

    2015-10-01

    An analysis of radiation, kinetic and fluid dynamic processes in diode pumped alkali lasers (DPALs) is reported. The analysis is based on a three-dimensional, time-dependent computational fluid dynamics (3D CFD) model. The CFD code which solves the gas conservation equations includes effects of natural convection and temperature diffusion of the species in the DPAL mixture. The gas flow conservation equations are coupled to the equations for DPAL kinetics and to the Beer-Lambert equations for pump and laser beams propagation. The DPAL kinetic processes in the Cs/CH4 (K/He) gas mixtures considered involve the three low energy levels, (1) n2S1/2, (2) n2P3/2 and (3) n2P1/2 (where n=4,6 for K and Cs, respectively), three excited alkali states and two alkali ionic states. Using the CFD model, the gas flow pattern and spatial distributions of the pump and laser intensities in the resonator were calculated for end-pumped CW and pulsed Cs and K DPALs. The DPAL power and medium temperature were calculated as a function of pump power and pump pulse duration. The CFD model results were compared to experimental results of Cs and K DPALs.

  6. Short cladding-pumped Er/Yb phosphate fiber laser with 1.5 W output power

    SciTech Connect

    Li, L.; Morrell, M.; Qiu, T.; Temyanko, V.L.; Schuelzgen, A.; Mafi, A.; Kouznetsov, D.; Moloney, J.V.; Luo, T.; Jiang, S.; Peyghambarian, N.

    2004-10-04

    We report experimental results on a high-power, cladding-pumped, heavily Er/Yb co-doped phosphate fiber laser of very short length. Up to 1.5 W cw laser power was obtained from an11-cm-long multimode-core active fiber with optimized input and output couplers, when pumped by a 15 W diode laser at 975 nm. The fiber laser was demonstrated at 1535 nm with a linewidth <1.2 nm, and a good beam quality of M{sup 2}<3.

  7. Vertical axis wind turbine power regulation through centrifugally pumped lift spoiling

    SciTech Connect

    Klimas, P.C.; Sladky, J.F. Jr.

    1985-01-01

    This paper describes an approach for lowering the rated windspeeds of Darrieus-type vertical axis wind turbines (VAWTs) whose blades are hollow aluminum extrusions. The blades, which when rotating act as centrifugal pumps, are fitted with a series of small perforations distributed along a portion of the blades' span. By valving the ends of the hollow blades, flow into the blade ends and out of the perforations may be controlled. This flow can induce premature aerodynamic stall on the blade elements, thereby reducing both the rated power of the turbine and its cost-of-energy. The concept has been proven on the Sandia National Laboratories 5-m diameter research VAWT and force balance and flow visualization wind tunnel tests have been conducted using a blade section designed for the VAWT application.

  8. Pump-seed synchronization for MHz repetition rate, high-power optical parametric chirped pulse amplification.

    PubMed

    Fattahi, Hanieh; Teisset, Catherine Yuriko; Pronin, Oleg; Sugita, Atsushi; Graf, Roswitha; Pervak, Vladimir; Gu, Xun; Metzger, Thomas; Major, Zsuzsanna; Krausz, Ferenc; Apolonski, Alexander

    2012-04-23

    We report on an active synchronization between two independent mode-locked lasers using a combined electronic-optical feedback. With this scheme, seed pulses at MHz repetition rate were amplified in a non-collinear optical parametric chirped pulse amplifier (OPCPA). The amplifier was seeded with stretched 1.5 nJ pulses from a femtosecond Ti:Sapphire oscillator, while pumped with the 1 ps, 2.9 µJ frequency-doubled output of an Yb:YAG thin-disk oscillator. The residual timing jitter between the two oscillators was suppressed to 120 fs (RMS), allowing for an efficient and broadband amplification at 11.5 MHz to a pulse energy of 700 nJ and an average power of 8 W. First compression experiment with 240 nJ amplified pulse energy resulted in a pulse duration of ~10 fs. PMID:22535076

  9. A solar powered distillation plant and pump station for use in ocean side desert areas

    SciTech Connect

    Dearien, J.A.; Priebe, S.J.

    1994-12-31

    There are thousands of miles of ocean shoreline which could sustain a productive human existence if sufficient fresh water were available for human consumption and for irrigation of crops. While solar stills can be built to produce fresh water at or close to sea level, raising water to a height sufficient to irrigate crops, even with minimum water usage crops, requires a significant amount of energy. This paper describes a ``no-external power`` process by which seawater can be purified and raised to a height above sea level sufficient to carry on a productive living in certain areas of the world. This device, the Solar Evaporation and Pumping System (SEAPS) is described as to function and areas of use.

  10. High-power high-repetition-rate copper-vapor-pumped dye laser

    SciTech Connect

    Singh, S.; Dasgupta, K.; Kumar, S.; Manohar, K.G.; Nair, L.G.; Chatterjee, U.K. . Laser and Plasma Technology Div.)

    1994-06-01

    The design and development of an efficient high average power dye laser oscillator-amplifier system developed at the Laser and Plasma Technology Division, Bhabha Atomic Research Centre, is reported. The dye laser is pumped by a 6.5-kHz repetition rate copper vapor laser. The signal beam to the dye amplifier is obtained from an efficient narrow-band grazing incidence grating (GIG) dye laser oscillator incorporating a multiple prism beam expander. Amplifier extraction efficiency up to 40% was obtained in a single amplifier stage, using rhodamine 6G (Rh6G) in ethanol. The authors have also demonstrated simultaneous amplification of two laser beams at different wavelengths in the same dye amplifier cell.

  11. Power scaling of end-pumped c-cut Tm:YAP lasers

    NASA Astrophysics Data System (ADS)

    Meng, P. B.; Yao, B. Q.; Ju, Y. L.; Wang, Y. Z.

    2013-12-01

    The temperature distributions of a Tm:YAP rod and a Tm:YAP slab were compared theoretically and experimentally. The measured thermal focal length was much longer for a thinner Tm:YAP slab than a Tm:YAP rod and a thicker Tm:YAP slab, indicating weaker thermal effects of a thinner Tm:YAP slab, which was in agreement with the theoretical analysis. Based on thermal effect analysis, laser performance of a c-cut Tm:YAP rod and slab in the dual-end-pumped configuration was compared. Higher slope efficiency and output power were obtained in the slab geometry than in the rod geometry, and the thinner the slab, the better the laser performance.

  12. Gastrostomy feeding tube - pump - child

    MedlinePlus

    Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding bag, drip chamber, roller clamp, ...

  13. 50-kHz, 50-ns UV pulse generation by diode-pumped frequency doubling Pr3+:YLF Q-switch laser with a Cr4+:YAG saturable absorber.

    PubMed

    Tanaka, Hiroki; Kariyama, Ryosuke; Iijima, Kodai; Kannari, Fumihiko

    2016-08-10

    We demonstrate intracavity second-harmonic generation at 320 nm of a diode-pumped praseodymium-doped YLF laser Q-switched by a Cr4+:YAG crystal. By employing two 3.5-W high-power blue InGaN diode lasers as the pump source, we obtained 50-ns Q-switched pulses with a pulse energy of 1.54 μJ at a repetition rate of 50 kHz. A rate equation analysis shows good agreement with the experimental results. PMID:27534459

  14. Enhanced efficiency of AlGaInP disk laser by in-well pumping.

    PubMed

    Mateo, C M N; Brauch, U; Schwarzbäck, T; Kahle, H; Jetter, M; Abdou Ahmed, M; Michler, P; Graf, T

    2015-02-01

    The performance of a 665-nm GaInP disk laser operated continuous-wave at 15°C both in-well-pumped at 640 nm and barrier pumped at 532 nm is reported. The efficiency with respect to the absorbed power was enhanced by 3.5 times when using a 640-nm pump instead of a 532-nm pump. In-well pumping which is based on the absorption of the pump photons within the quantum-well heterostructures of the gain region instead of short-wavelength absorption in the barrier and spacer regions reduces the quantum defect between pump and laser photon and hence the heat generation. A slope efficiency of 60% with respect to the absorbed pump power was obtained by in-well pumping at 15°C. Continuous-wave laser operation was further demonstrated at heat sink temperatures of up to 55°C. Both the measurement of photoluminescence and COMSOL simulation show that the overall heat load in the in-well pumped laser is smaller than in the barrier-pumped laser. These results demonstrate the potential of optical in-well pumping for the operation of red AlGaInP disk lasers if combined with means for efficient pump-light absorption. PMID:25836115

  15. High power mid-infrared continuous-wave optical parametric oscillator pumped by fiber lasers

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojun; Li, Xiao; Liu, Lei; Shang, Yaping

    2015-02-01

    3~5μm mid-infrared laser has many important applications, such as gas detection, spectral analysis, remote sensing, medical treatment, and also in the military laser radar, infrared countermine, and so on. Optical parametric oscillator (OPO) is an efficient way to generate laser in this wavelength range, which has attracted the eyes of many people. In this paper, the recent development of mid-infrared OPO is overviewed. Meanwhile, detailed introduction on our recent work is given. Maximum idler output power of 34.2W at center wavelength of 3.35μm was obtained, to our knowledge, which is the new power record of the international public reporting for the continue-wave (CW) mid-infrared OPO. It is worth mentioning that the pump source, the quasi single-frequency (SF) narrow line width fiber laser, was also developed by our groups. According to the current status of research, some solutions is proposed in order to achieve higher power, narrower line width, and compact volume mid-infrared OPO in a wide tunable range.

  16. ION PUMP

    DOEpatents

    Milleron, N.

    1961-01-01

    An ion pump and pumping method are given for low vacuum pressures in which gases introduced into a pumping cavity are ionized and thereafter directed and accelerated into a quantity of liquid gettering metal where they are absorbed. In the preferred embodiment the metal is disposed as a liquid pool upon one electrode of a Phillips ion gauge type pump. Means are provided for continuously and remotely withdrawing and degassing the gettering metal. The liquid gettering metal may be heated if desired, although various combinations of gallium, indium, tin, bismuth, and lead, the preferred metals, have very low melting points. A background pressure of evaporated gettering metal may be provided by means of a resistance heated refractory metal wick protruding from the surface of the pcol of gettering metal.

  17. Externally tuned vibration absorber

    DOEpatents

    Vincent, Ronald J.

    1987-09-22

    A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

  18. LD pumped high-repetition-rate high-power 532nm Nd:YAG/LBO solid state laser

    NASA Astrophysics Data System (ADS)

    Li, Pingxue; Liu, Dongyu; Chi, Junjie; Yang, Chun; Zhao, Ziqiang; Hu, Haowei; Zhang, Guangju; Yao, Yifei

    2013-09-01

    Diode pumped solid state 532 nm green laser is widely required for many industrial, medical and scientific applications. Among most of these applications, high power quasi-continuous-wave (QCW) green laser output is demanded. This can be efficiently achieved through a diode-side-pumped acoustic-optic Q-switched Nd:YAG laser with an intracavity second harmonic generation (SHG). In our experiment, LBO crystal is used for the second harmonic generation of high-average-power lasers of near infrared (NIR) range, though its effective NLO coefficient deff is relatively small. It is because of its high damage threshold (greater than 2.5 GW/cm2), large acceptance angle, small walk-off angle, and the nonhygroscopic characteristic. In this paper, we reported a high-repetition-rate high-power diode-side-pumped AO Q-switched Nd:YAG 532 nm laser. A plane-plane cavity with two rods, two AO Q-switches and the type II critical phase-matched LBO at room temperature were employed. Under the LD pump power of 480 W, 95.86 W at 1064 nm wavelength was achieved when the repetition rate was 15 kHz, and the 532 nm average output power of 44.77 W was obtained, with a pulse width of 111.7 ns, corresponding to an optical to optical conversion efficiency of 46.7% from 1064 nm to 532 nm. The 532 nm average output power was 40.10 W at a repetition rate of 10 kHz with a pulse width of 78.65 ns. The output characteristics of the SHG varying with the pumping current and the pulse repetition frequency (PRF) of the laser were also investigated. Further improvement of the SHG is under study.

  19. Generation of a Periodic Series of High-Power Ultra-Short Pulses in a Gyro-TWT with a Bleachable Cyclotron Absorber in the Feedback Circuit

    NASA Astrophysics Data System (ADS)

    Vilkov, M. N.; Ginzburg, N. S.; Denisov, G. G.; Zotova, I. V.; Sergeev, A. S.

    2016-01-01

    We demonstrate the possibility of forming a periodic series of ultra-short pulses, which has a peak power exceeding significantly the radiation power in stationary regimes, in a gyroresonance traveling-wave tube (gyro-TWT) with a bleachable cyclotron absorber in the feedback circuit. The mechanism of pulsed generation is similar to the method of passive mode locking, which is used widely in laser physics.

  20. Theoretical and numerical treatment of modal instability in high-power core and cladding-pumped Raman fiber amplifiers.

    PubMed

    Naderi, Shadi; Dajani, Iyad; Grosek, Jacob; Madden, Timothy

    2016-07-25

    Raman fiber lasers have been proposed as potential candidates for scaling beyond the power limitations imposed on near diffraction-limited rare-earth doped fiber lasers. One limitation is the modal instability (MI) and we explore the physics of this phenomenon in Raman fiber amplifiers (RFAs). By utilizing the conservation of number of photons and conservation of energy in the absence of loss, the 3 × 3 governing system of nonlinear equations describing the pump and the signal modal content are decoupled and solved analytically for cladding-pumped RFAs. By comparing the extracted signal at MI threshold for the same step index-fiber, it is found that the MI threshold is independent of the length of the amplifier or whether the amplifier is co-pumped or counter-pumped; dictated by the integrated heat load along the length of fiber. We extend our treatment to gain-tailored RFAs and show that this approach is of limited utility in suppressing MI. Finally, we formulate the physics of MI in core-pumped RFAs where both pump and signal interferences participate in writing the time-dependent index of refraction grating. PMID:27464110

  1. High Power Diode-End-Pumped Nd:YAG 946-nm Laser and Its Efficient Frequency Doubling

    NASA Astrophysics Data System (ADS)

    Zhou, Rui; Zhao, Shi-Yong; Cai, Zhi-Qiang; Zhang, Qiang; Wen, Wu-Qi; Ding, Xin; Wang, Peng; Ding, Li-Li; Yao, Jian-Quan

    2005-06-01

    We report a high power operation of the 4F3/2→4I9/2 transition in diode-end-pumped laser at 946 nm. The maximum output of 5.1 W is obtained with a short linear plano-concave cavity, and the slope efficiency is 24.5% at incident pump power of 23.3 W. To our knowledge, this is the highest value of the LD-pumped Nd:YAG 946 nm lasers that employ the conversional Nd:YAG rod as the gain medium. By intracavity frequency doubling with an LBO crystal, up to 982 mW cw output power in the blue spectral range at 473 nm is achieved at an incident pump power of 10.9 W with a compact three-element cavity, leading to optical-to-optical conversion efficiency of 9%. The conversion efficiency should be increased to 15.1%, if the rather low absorption coefficient of this Nd:YAG is considered.

  2. High-power CW diode-laser-array-pumped solid-state lasers and efficient nonlinear optical frequency

    NASA Astrophysics Data System (ADS)

    Shine, Robert J.; Byer, Robert L.

    1994-01-01

    During the interim period of this bridging contract, we have continued to work on the development of high-power cw diode-laser-array-pumped solid-state lasers. Towards that end, we have built lower power lasers in order to test individual components needed for the high-power laser, specifically we have built a 1 watt ring laser and a 5 watt slab laser. The 1 watt laser was used to study the injection locking process while assembling all the necessary electronics. We have demonstrated that it is possible to injection lock a diode-pumped laser using a single piezo-mounted mirror due to the lower intrinsic laser noise compared to an arc-lamp-pumped system. This allows us to optimize the injection locking servo loop and build a more stable locking system. The 5 watt laser was used as a test bed to find a practical way to mount the slab laser while minimizing the losses that occur at the total internal reflection (TIR) points in the slab. After trying many different means of protecting the TIR surfaces, we found that a new product from DuPont, Teflon AF 1600, has all the properties needed to provide a low loss protective coating. Using this material, the laser had a cavity loss of below 2%, which allowed for efficient operation of the laser in a side-pumped design. This laser produced 5 watts of output power with a slope efficiency near 20%.

  3. High-power multichannel PPMgLN-based optical parametric oscillator pumped by a master oscillation power amplification-structured Q-switched fiber laser.

    PubMed

    Chen, Tao; Wei, Kaihua; Jiang, Peipei; Wu, Bo; Shen, Yonghang

    2012-10-01

    We experimentally demonstrated a compact fiber laser-pumped multichannel PPMgLN-based optical parametric oscillator (OPO) generating total OPO output power of 15.8, 15.2, 14.2, 12.9, and 8.8 W with idler output power of 4.7, 4.3, 4.1, 3.3, and 2.1 W at the wavelength of 3.43, 3.63, 3.72, 3.83, and 3.99 μm, respectively. The OPO was pumped by a fully fiberized polarization maintaining (PM) ytterbium-doped pulsed fiber master oscillation power amplifier (MOPA) operating at 1064 nm at a repetition rate of 65 kHz with effective pump power of 28.7 W. The MOPA system was constructed with an acousto-optic Q-switched fiber laser seed and only one stage PM fiber amplifier without any free space components, which makes the pump system compact and stable in the long-term. Comparisons on efficiencies and signal wavelength shifts between different channels showed that the idler absorption was the main factor preventing high average-power OPO operation with long idler wavelength. PMID:23033106

  4. Design and development of a high-power LED-pumped Ce:Nd:YAG laser.

    PubMed

    Villars, Brenden; Steven Hill, E; Durfee, Charles G

    2015-07-01

    By studying quasi-continuous wave (QCW) operation of a Ce:Nd:YAG solid-state laser directly pumped by LED arrays, we demonstrate the feasibility of direct-LED pumping as an alternative to direct-diode or flashlamp pumping. LEDs emitting either at 460 or 810 nm were used to pump an uncooled Ce:Nd:YAG laser rod (at 30-Hz repetition rate for tens of seconds). Pumping at 460 nm was made possible by the Ce(3+) co-dopant that enables transfer of excitations near to Nd(3+) ions in the YAG lattice. Comparison of these two pumping schemes has allowed for a thorough analysis of the performance and efficiency of this laser system. QCW output energies as high as 18 mJ/pulse are reported, which to the best of our knowledge is the highest output pulse energy achieved by an LED-pumped solid-state laser to date. PMID:26125364

  5. Advancements in high-power high-brightness laser bars and single emitters for pumping and direct diode application

    NASA Astrophysics Data System (ADS)

    An, Haiyan; Jiang, Ching-Long J.; Xiong, Yihan; Zhang, Qiang; Inyang, Aloysius; Felder, Jason; Lewin, Alexander; Roff, Robert; Heinemann, Stefan; Schmidt, Berthold; Treusch, Georg

    2015-03-01

    We have continuously optimized high fill factor bar and packaging design to increase power and efficiency for thin disc laser system pump application. On the other hand, low fill factor bars packaged on the same direct copper bonded (DCB) cooling platform are used to build multi-kilowatt direct diode laser systems. We have also optimized the single emitter designs for fiber laser pump applications. In this paper, we will give an overview of our recent advances in high power high brightness laser bars and single emitters for pumping and direct diode application. We will present 300W bar development results for our next generation thin disk laser pump source. We will also show recent improvements on slow axis beam quality of low fill factor bar and its application on performance improvement of 4-5 kW TruDiode laser system with BPP of 30 mm*mrad from a 600 μm fiber. Performance and reliability results of single emitter for multiemitter fiber laser pump source will be presented as well.

  6. Real-time condition monitoring of thermal power plants feed-pumps by rolling bearings supports vibration

    NASA Astrophysics Data System (ADS)

    Kostyukov, V. N.; Tarasov, E. V.

    2012-05-01

    The report addresses the real-time condition monitoring of technical state and automatic diagnosis of auxiliary equipment for bearings supports vibration, for example, control of the feed-pump operating modes of thermal power stations. The causes that lead to premature birth and development of defects in rolling bearings are identified and the development of activities ensuring safe and continuous operation of the auxiliary equipment of thermal power stations is carried out. Collection and analysis of vibration parameters of pumping units during their operation at the operating modes of the technological process are realized by means of real-time technical condition monitoring. Spectral analysis of vibration parameters of one of the pumps showed the presence of frequency components, which mark violations in the operating practices of the pump, the imbalance development and, as a consequence, the development of defects in the bearings by long-term operation of the unit. Timely warning of the personnel on the operation of the unit with the "INTOLERABLE" technical state and automatic warning issuance of the need to change the technological process allowed to recover the estimated pump operation mode in due time and prevent further development of defects in equipment.

  7. Gas pump with movable gas pumping panels

    DOEpatents

    Osher, J.L.

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  8. Gas pump with movable gas pumping panels

    DOEpatents

    Osher, John E.

    1984-01-01

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  9. Study of the longitudinal distribution of power generated in a random distributed feedback Raman fibre laser with unidirectional pumping

    SciTech Connect

    Churkin, D V; El-Taher, A E; Vatnik, I D; Babin, Sergei A

    2012-09-30

    The longitudinal distribution of the Stokes-component power in a Raman fibre laser with a random distributed feedback and unidirectional pumping is measured. The fibre parameters (linear loss and Rayleigh backscattering coefficient) are calculated based on the distributions obtained. A numerical model is developed to describe the lasing power distribution. The simulation results are in good agreement with the experimental data. (optical fibres, lasers and amplifiers. properties and applications)

  10. Photo-excited broadband tunable terahertz metamaterial absorber

    NASA Astrophysics Data System (ADS)

    Zhang, Jianna; Wang, Guocui; Zhang, Bo; He, Ting; He, Yanan; Shen, Jingling

    2016-04-01

    We demonstrate a photo-excited broadband tunable metamaterial absorber for use in the terahertz region. The metamaterial absorber consists of a hybrid metal-semiconductor square split ring and a metallic ground plane that are separated by a dielectric resonator spacer. The conductivity of the silicon used to fill the gap in the metallic resonator is tuned actively as a function of the incident pump power, which results in frequency modulation of the resonance absorption peak. Broadband tunable metamaterial absorbers are produced by suitable placement of the photoconductive silicon in different critical regions of the metallic resonator. In addition, the proposed method is applicable to a concentric rings-based metallic resonator. The proposed photo-excited broadband tunable metamaterial absorber has numerous potential applications, including uses as terahertz modulators and switches.

  11. Optimal Operation and Value Evaluation of Pumped Storage Power Plants Considering Spot Market Trading and Uncertainty of Bilateral Demand

    NASA Astrophysics Data System (ADS)

    Takahashi, Kenta; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

    In recent years, as the deregulation in electric power industry has advanced in many countries, a spot market trading of electricity has been done. Generation companies are allowed to purchase the electricity through the electric power market and supply electric power for their bilateral customers. Under this circumstance, it is important for the generation companies to procure the required electricity with cheaper cost to increase their profit. The market price is volatile since it is determined by bidding between buyer and seller. The pumped storage power plant, one of the storage facilities is promising against such volatile market price since it can produce a profit by purchasing electricity with lower-price and selling it with higher-price. This paper discusses the optimal operation of the pumped storage power plants considering bidding strategy to an uncertain spot market. The volatilities in market price and demand are represented by the Vasicek model in our estimation. This paper also discusses the allocation of operational reserve to the pumped storage power plant.

  12. Low-Pump-Power, Low-Phase-Noise, and Microwave to Millimeter-Wave Repetition Rate Operation in Microcombs

    NASA Astrophysics Data System (ADS)

    Li, Jiang; Lee, Hansuek; Chen, Tong; Vahala, Kerry J.

    2012-12-01

    Microresonator-based frequency combs (microcombs or Kerr combs) can potentially miniaturize the numerous applications of conventional frequency combs. A priority is the realization of broadband (ideally octave spanning) spectra at detectable repetition rates for comb self-referencing. However, access to these rates involves pumping larger mode volumes and hence higher threshold powers. Moreover, threshold power sets both the scale for power per comb tooth and also the optical pump. Along these lines, it is shown that a class of resonators having surface-loss-limited Q factors can operate over a wide range of repetition rates with minimal variation in threshold power. A new, surface-loss-limited resonator illustrates the idea. Comb generation on mode spacings ranging from 2.6 to 220 GHz with overall low threshold power (as low as 1 mW) is demonstrated. A record number of comb lines for a microcomb (around 1900) is also observed with pump power of 200 mW. The ability to engineer a wide range of repetition rates with these devices is also used to investigate a recently observed mechanism in microcombs associated with dispersion of subcomb offset frequencies. We observe high-coherence phase locking in cases where these offset frequencies are small enough so as to be tuned into coincidence. In these cases, a record-low microcomb phase noise is reported at a level comparable to an open-loop, high-performance microwave oscillator.

  13. High-power, fiber-laser-pumped, picosecond optical parametric oscillator based on MgO:sPPLT.

    PubMed

    Kumar, S Chaitanya; Ebrahim-Zadeh, M

    2011-12-19

    We report a stable, high-power, mid-infrared synchronously-pumped optical parametric oscillator (SPOPO) based on MgO:sPPLT, pumped by a 1064 nm, picosecond Yb-fiber laser operating at a repetition rate of 81.1 MHz. The singly resonant SPOPO is tunable over 1531-1642 nm (111 nm) in the near-infrared signal and 3022-3488 nm (466 nm) in the mid-infrared idler, providing a total tuning range of 577 nm. Careful optimization of output coupling results in a signal output power as high as 4.3 W at 1593 nm and a mid-infrared idler power of 2 W at 3204 nm for 13.4 W of pump power at a total extraction efficiency of 47%. The SPOPO can be operated near room temperature, down to 30 °C, and exhibits passive peak-to-peak power stability better than 8.6% at 1568 nm (signal) and 8.2% at 3310 nm (idler) over 13 hours at full power. The output signal pulses have duration of 17.5 ps, with a FWHM spectral bandwidth of 1.4 nm centered at 1568 nm. PMID:22274250

  14. Internal absorber solar collector

    DOEpatents

    Sletten, Carlyle J.; Herskovitz, Sheldon B.; Holt, F. S.; Sletten, E. J.

    1981-01-01

    Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

  15. Power scaling of laser diode pumped Pr3+:LiYF4 cw lasers: efficient laser operation at 522.6 nm, 545.9 nm, 607.2 nm, and 639.5 nm.

    PubMed

    Gün, Teoman; Metz, Philip; Huber, Günter

    2011-03-15

    We report efficient cw laser operation of laser diode pumped Pr(3+)-doped LiYF4 crystals in the visible spectral region. Using two InGaN laser diodes emitting at λ(P)=443.9 nm with maximum output power of 1 W each and a 2.9-mm-long crystal with a doping concentration of 0.5%, output powers of 938 mW, 418 mW, 384 mW, and 773 mW were achieved for the laser wavelengths 639.5 nm, 607.2 nm, 545.9 nm, and 522.6 nm, respectively. The maximum absorbed pump powers were approximately 1.5 W, resulting in slope efficiencies of 63.6%, 32.0%, 52.1%, and 61.5%, as well as electro-optical efficiencies of 9.4%, 4.2%, 3.8%, and 7.7%, respectively. Within these experiments, laser diode-pumped laser action at 545.9 nm was demonstrated for what is believed to be the first time. PMID:21403756

  16. High-Efficiency Absorber for Damping the Transverse Wake Fields

    SciTech Connect

    Novokhatski, A.; Seeman, J.; Weathersby, S.; /SLAC

    2007-02-28

    Transverse wake fields generated by intense beams may propagate long distances in the vacuum chamber and dissipate power in different shielded elements such as bellows, vacuum valves or vacuum pumps. Induced heating in these elements may be high enough to deteriorate vacuum conditions. We have developed a broadband water-cooled bellows-absorber to capture and damp these harmful transverse fields without impacting the longitudinal beam impedance. Experimental results at the PEP-II SLAC B-factory demonstrate high efficiency of this device. This absorber may be useful in other machines like synchrotron light sources or International Linear Collider.

  17. High-efficiency absorber for damping transverse wakefields

    NASA Astrophysics Data System (ADS)

    Novokhatski, A.; Seeman, J.; Weathersby, S.

    2007-04-01

    Transverse wakefields generated by intense beams may propagate long distances in a vacuum chamber and dissipate power in different shielded elements such as bellows, vacuum valves, or vacuum pumps. Induced heating in these elements may be high enough to deteriorate vacuum conditions. We have developed a broadband water-cooled bellows absorber to capture and damp these harmful transverse fields without impacting the longitudinal beam impedance. Experimental results at the PEP-II SLAC B-factory demonstrate a high efficiency for this device. This absorber may be useful in super B-factories, the International Linear Collider, the Large Hadron Collider, or synchrotron light sources.

  18. Cavitation performance tests on the primary pump model of a nuclear power plant

    SciTech Connect

    Rao, A.S.L.K.; Kale, R.D.; Chougule, R.J.; Joshi, S.G.

    1994-12-31

    This paper discusses in detail cavitation performance tests on a 1/3 model of the primary sodium pump for the proposed Prototype fast Breeder Reactor. The prototype pump has a rated capacity of 2.09 m{sup 3}/s at a delivery head of 80 mlc when operating at the rated speed of 700 rpm. The available NPSH is a modest 14 mlc and it is required that the hydraulic design of the pump be such as to have zero cavitation at the normal operating speed. The details of cavitational study of the model pump and comparison of experimental observations with model predictions is discussed.

  19. A reliable, programmable acoustofluidic pump powered by oscillating sharp-edge structures

    PubMed Central

    Huang, Po-Hsun; Nama, Nitesh; Mao, Zhangming; Li, Peng; Rufo, Joseph; Chen, Yuchao; Xie, Yuliang; Wei, Cheng-Hsin; Wang, Lin; Huang, Tony Jun

    2014-01-01

    We present a programmable acoustofluidic pump that utilizes the acoustic streaming effects generated by the oscillation of tilted sharp-edge structures. This sharp-edge based acoustofluidic pump is capable of generating stable flow rates as high as 8 μL/min (~76 Pa of pumping pressure), and it can tune flow rates across a wide range (nL/min to μL/min). Along with its ability to reliably produce stable and tunable flow rates, the acoustofluidic pump is easy to operate and requires minimum hardware, showing great potential for a variety of applications. PMID:25188786

  20. Photothermally tunable silicon-microring-based optical add-drop filter through integrated light absorber.

    PubMed

    Chen, Xi; Shi, Yuechun; Lou, Fei; Chen, Yiting; Yan, Min; Wosinski, Lech; Qiu, Min

    2014-10-20

    An optically pumped thermo-optic (TO) silicon ring add-drop filter with fast thermal response is experimentally demonstrated. We propose that metal-insulator-metal (MIM) light absorber can be integrated into silicon TO devices, acting as a localized heat source which can be activated remotely by a pump beam. The MIM absorber design introduces less thermal capacity to the device, compared to conventional electrically-driven approaches. Experimentally, the absorber-integrated add-drop filter shows an optical response time of 13.7 μs following the 10%-90% rule (equivalent to a exponential time constant of 5 μs) and a wavelength shift over pump power of 60 pm/mW. The photothermally tunable add-drop filter may provide new perspectives for all-optical routing and switching in integrated Si photonic circuits. PMID:25401557

  1. Absorber for terahertz radiation management

    DOEpatents

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  2. Semiconductor disk laser-pumped subpicosecond holmium fibre laser

    SciTech Connect

    Chamorovskiy, A Yu; Marakulin, A V; Leinonen, T; Kurkov, Andrei S; Okhotnikov, Oleg G

    2012-01-31

    The first passively mode-locked holmium fibre laser has been demonstrated, with a semiconductor saturable absorber mirror (SESAM) as a mode locker. Semiconductor disk lasers have been used for the first time to pump holmium fibre lasers. We obtained 830-fs pulses at a repetition rate of 34 MHz with an average output power of 6.6 mW.

  3. High-average-power Nd:YAG planar waveguide laser that is face pumped by 10 laser diode bars.

    PubMed

    Lee, J R; Baker, H J; Friel, G J; Hilton, G J; Hall, D R

    2002-04-01

    A planar waveguide Nd:YAG laser is pumped with 430 W of power from 10 laser diode bars to produce a multimode output power of 150 W at an optical efficiency of 35%. Use of a hybrid resonator of the positive-branch confocal unstable type for the lateral axis and of one of the near-case I waveguide type for the transverse axis increased the laser brightness by a factor of ~26 with only 12% less power than in the multimode case. PMID:18007853

  4. Prospects for using heat pumps in systems supplying power to industrial and municipal enterprises

    NASA Astrophysics Data System (ADS)

    Efimov, N. N.; Malyshev, P. A.

    2009-11-01

    The use of heat pumps for industrial and municipal applications is analyzed. It is shown that application of heat-pump units in the heating systems of industrial and municipal enterprises is already economically justified with the existing tariffs for electricity and natural gas.

  5. Diode-laser-pumped tunable 896-939.5-nm neodymium-doped fiber laser with 43-mW output power.

    PubMed

    Cook, A L; Hendricks, H D

    1998-05-20

    A diode-laser-pumped neodymium-doped fiber laser is presented. For a launched pump power of 85 mW, the fiber laser had a cw output power of 43 mW, which is approximately an order of magnitude greater output power than any previously reported diode-pumped neodymium fiber laser operating on the 4F(3/2)-4I(9/2) transition, which covers the 900-950-nm region. The fiber laser had a threshold power of 10 mW and a slope efficiency of 58% with respect to launched pump power. Tuning with a diffraction grating was obtained from 896 to 937 nm with narrow-band output powers as high as 32 mW. Emission was also obtained at 939.5 nm with use of a fiber Bragg grating as the output reflector. PMID:18273282

  6. High-brightness power delivery for fiber laser pumping: simulation and measurement of low-NA fiber guiding

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    Fiber laser manufacturers demand high-brightness laser diode pumps delivering optical pump energy in both a compact fiber core and narrow angular content. A pump delivery fiber of a 105 μm core and 0.22 numerical aperture (NA) is typically used, where the fiber NA is under-filled to ease the launch of laser diode emission into the fiber and make the fiber tolerant to bending. At SCD, we have developed multi-emitter fiber-coupled pump modules that deliver 50 W output from a 105 μm, 0.15 NA fiber at 915, 950 and 976 nm wavelengths enabling low-NA power delivery to a customer's fiber laser network. In this work, we address the challenges of coupling and propagating high optical powers from laser diode sources in weakly guiding step-index multimode fibers. We present simulations of light propagation inside the low-NA multimode fiber for different launch conditions and fiber bend diameters using a ray-racing tool and demonstrate how these affect the injection of light into cladding-bounded modes. The mode filling at launch and source NA directly limit the bend radius at which the fiber can be coiled. Experimentally, we measure the fiber bend loss using our 50 W fiber-coupled module and establish a critical bend diameter in agreement with our simulation results. We also employ thermal imaging to investigate fiber heating caused by macro-bends and angled cleaving. The low mode filling of the 0.15 NA fiber by our brightness-enhanced laser diodes allows it to be coiled with diameters down to 70 mm at full operating power despite the low NA and further eliminates the need for mode-stripping at fiber combiners and splices downstream from our pump modules.

  7. Packed Alumina Absorbs Hypergolic Vapors

    NASA Technical Reports Server (NTRS)

    Thomas, J. J.; Mauro, D. M.

    1984-01-01

    Beds of activated alumina effective as filters to remove hypergolic vapors from gas streams. Beds absorb such substances as nitrogen oxides and hydrazines and may also absorb acetylene, ethylene, hydrogen sulfide, benzene, butadiene, butene, styrene, toluene, and xoylene. Bed has no moving parts such as pumps, blowers and mixers. Reliable and energy-conservative. Bed readily adapted to any size from small portable units for use where little vapor release is expected to large stationary units for extensive transfer operations.

  8. Effects of pipe diameters on the pressures during delayed load rejection in high-head pumped storage power stations

    NASA Astrophysics Data System (ADS)

    Zeng, W.; Yang, J. D.

    2014-03-01

    High-head pumped storage power stations face serious problems related to the transient process, especially in the area of delayed load rejection in stations with annular piping layouts. The controlled pressures are adversely affected, which leads to many problems in the engineering design phase. In this study, we investigated this condition through theoretical analysis, numerical simulation, and actual engineering practice. We concluded that the root cause of the pressure issues is the flow switching resulted from the non-synchronous changes in pressure between each branch pipe. Moreover, we examined the impact of the diameters of the upstream main pipe and branch pipe on the controlled pressures and determined that the diameter of the branch pipe has a major influence on the pressures as it changes the flow switching rate. A similar investigation was conducted for downstream pipes. Our conclusions can be applied to actual engineering practice for high-head pumped storage power stations.

  9. A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

    NASA Astrophysics Data System (ADS)

    Aloulou, R.; De Peslouan, P.-O. Lucas; Mnif, H.; Alicalapa, F.; Luk, J. D. Lan Sun; Loulou, M.

    2016-05-01

    Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm2. Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.

  10. On the possibility of connecting a non-operating main circulation pump with three pumps in operation without preliminary coast-down of power-generating unit No. 5 in the Novovoronezh nuclear power plant

    NASA Astrophysics Data System (ADS)

    Vitkovskii, I. L.; Nikonov, S. P.; Ryasnyi, S. I.

    2014-02-01

    The subject of this paper is a transient caused by connection of a standby loop to three operating circulation pumps at the initial reactor heat rate equal to 70% of the rated value without preliminarily reducing it to 30% of the rated level as required by the safe operation regulations. Failure of the following normal operation systems is supposed: the first- and the second-type warning protection systems, all quick-acting reducing devices releasing steam into the auxiliary manifold, the electric heaters of the pressurizer, the pressurizer injection system, the primary cooling circuit fluid makeup/blow-through systems, and the blocking systems to shut down the main circulation pump after the level in the steam generator is exceeded. In addition, it is supposed that, under transient conditions, the valves of the turbine regulation system will be in the position in which they were at the moment of the initial event until generation of the signal for positive closing of the turbine stop valves. The first signal to actuate the reactor emergency protection system (EPS) is skipped. The failure of all quick-acting reducing devices releasing steam into the atmosphere is assumed. In addition to equipment failure, at the moment when the main circulation pump is connected, the operator erroneously puts in a new setting to maintain the power allowable for four pumps in operation-in the calculations it was taken equal to 104% of the rated level at most considering the accuracy of evaluating and maintaining the reactor heat rate-and the working group of the reactor protection and control system (P&CS) starts moving upward. On reaching the set power level, the automatic reactor power regulator stops operating and the P&CS elements remain in the position in which they are at the moment. Compliance with the design safety criteria for the adopted scenario of the transient is demonstrated.

  11. A dynamic model for power deposition in 3He lasers pumped by 3He(n,p) 3H reactions

    NASA Astrophysics Data System (ADS)

    Çetin, Füsun

    2004-07-01

    The coupled variation of power density with gas density in a nuclear-pumped laser, which is excited by 3He(n,p) 3H reaction products, is considered. In the literature, volumetric excitation by reaction products of 3He(n,p) 3H is only considered for the case in which gas density is uniform and does not change during the pumping. In this work, a time-dependent model describing the coupled fluid dynamic and particle transport behaviour of the gas has been developed. In modelling charge particle transport behaviour, a previously reported energy deposition model for a constant gas density is extended for a variable gas density by taking into account variations in the particle range, macroscopic cross sections and neutron flux depending on density field of the gas. The coupled equations, which are obtained by using the power deposition density expression obtained for variable gas density in the acoustically filtered equations of motion of the gas, are solved numerically. Spatial and temporal variations of power deposition density and gas density during the pumping pulse are determined for various operating pressures ranging from 0.5 to 10 atm. In the calculations, the characteristics of I.T.U TRIGA Mark-II Reactor are used and it is assumed that laser tube is placed in the centre of the reactor core. Obtained results are presented and examined.

  12. Investigations on the potential of a low power diode pumped Er:YAG laser system for oral surgery

    NASA Astrophysics Data System (ADS)

    Stock, Karl; Wurm, Holger; Hausladen, Florian; Wagner, Sophia; Hibst, Raimund

    2015-02-01

    Flash lamp pumped Er:YAG-lasers are used in clinical practice for dental applications successfully. As an alternative, several diode pumped Er:YAG laser systems (Pantec Engineering AG) become available, with mean laser power of 2W, 15W, and 30W. The aim of the presented study is to investigate the potential of the 2W Er:YAG laser system for oral surgery. At first an appropriate experimental set-up was realized with a beam delivery and both, a focusing unit for non-contact tissue cutting and a fiber tip for tissue cutting in contact mode. In order to produce reproducible cuts, the samples (porcine gingiva) were moved by a computer controlled translation stage. On the fresh samples cutting depth and quality were determined by light microscopy. Afterwards histological sections were prepared and microscopically analyzed regarding cutting depth and thermal damage zone. The experiments show that low laser power ≤ 2W is sufficient to perform efficient oral soft tissue cutting with cut depth up to 2mm (sample movement 2mm/s). The width of the thermal damage zone can be controlled by the irradiation parameters within a range of about 50μm to 110μm. In general, thermal injury is more pronounced using fiber tips in contact mode compared to the focused laser beam. In conclusion the results reveal that even the low power diode pumped Er:YAG laser is an appropriate tool for oral surgery.

  13. Remotely powered distributed microfluidic pumps and mixers based on miniature diodes.

    PubMed

    Chang, Suk Tai; Beaumont, Erin; Petsev, Dimiter N; Velev, Orlin D

    2008-01-01

    We demonstrate new principles of microfluidic pumping and mixing by electronic components integrated into a microfluidic chip. The miniature diodes embedded into the microchannel walls rectify the voltage induced between their electrodes from an external alternating electric field. The resulting electroosmotic flows, developed in the vicinity of the diode surfaces, were utilized for pumping or mixing of the fluid in the microfluidic channel. The flow velocity of liquid pumped by the diodes facing in the same direction linearly increased with the magnitude of the applied voltage and the pumping direction could be controlled by the pH of the solutions. The transverse flow driven by the localized electroosmotic flux between diodes oriented oppositely on the microchannel was used in microfluidic mixers. The experimental results were interpreted by numerical simulations of the electrohydrodynamic flows. The techniques may be used in novel actively controlled microfluidic-electronic chips. PMID:18094769

  14. High peak power miniature Yb:CNGG disordered crystal laser end-pumped by a 935-nm diode

    NASA Astrophysics Data System (ADS)

    Dai, Qibiao; Yi, Hongying; Chen, Xiaowen; Han, Wenjuan; Zhang, Huaijin; Wang, Shiwu; Liu, Junhai

    2014-04-01

    We report on an efficient miniature Yb:CNGG disordered crystal laser, which is passively Q-switched with a Cr4+:YAG crystal plate acting as saturable absorber. An average output power of 1.35 W is generated at a pulse repetition rate of 5.55 kHz with a slope efficiency of 42%; the resulting laser pulse energy and duration are respectively 243 μJ and 3.0 ns, while the peak power is as high as 81 kW.

  15. High-efficiency direct-pumped Nd:YVO 4-LBO laser operating at 671 nm

    NASA Astrophysics Data System (ADS)

    Lü, Yan-Fei; Zhang, Xi-He; Xia, Jing; Yin, Xiao-Dong; Zhang, An-Feng; Bao, Lin; Lü, Wang

    2010-04-01

    The continuous-wave high-efficiency laser emission from Nd:YVO 4 at the fundamental wavelength of 1342 nm and its 671 nm second harmonic obtained by intra-cavity frequency doubling in an LBO nonlinear crystal are investigated under pumping by diode laser at 880 nm (on the 4F 3/2→ 4I 13/2 transition). The end-pumped Nd:YVO 4 crystal yielded a continuous-wave output power of 9.6 W at 1342 nm for 18.9 W of absorbed pump power. The slope efficiency measured with respect to the absorbed pump power is 60%. An output of 5.5 W at 671 nm was obtained by frequency doubling, resulting in an optical-to-optical efficiency with respect to the absorbed pump power of 29%. Comparative results obtained for the pump with a diode laser at 808 nm (on the 4F 5/2→ 4I 13/2 transition) are given in order to prove the advantages of the 880 nm wavelength pumping.

  16. Adaptive compensation of lower order thermal aberrations in concave-convex power oscillators under variable pump conditions

    NASA Astrophysics Data System (ADS)

    Jackel, Steven M.; Moshe, Inon

    2000-09-01

    A Nd:Cr:GSGG concave-convex power oscillator was developed that utilized both an adaptive mirror comprised of spherical and cylindrical optical elements together with a Faraday rotator to dynamically eliminate lower order aberrations (thermal focusing, astigmatism, and bipolar focusing). An adaptively controlled collimating lens corrected for shifts in the mode-waist position. The addition of a polarizer and a reentrant mirror totally eliminated thermal birefringence losses. The techniques developed are attractive in any solid state laser that must work under changing pump power conditions.

  17. High-power efficient cw and pulsed lasers based on bulk Yb : KYW crystals with end diode pumping

    SciTech Connect

    Kim, G H; Yang, G H; Lee, D S; Kulik, Alexander V; Sall', E G; Chizhov, S A; Yashin, V E; Kang, U

    2012-04-30

    End-diode-pumped lasers based on one and two Yb : KYW crystals operating in cw and Q-switched regimes, as well as in the regime of mode-locking, are studied. The single-crystal laser generated stable ultrashort (shorter than 100 fs) laser pulses at wavelengths of 1035 and 1043 nm with an average power exceeding 1 W. The average output power of the two-crystal laser exceeded 18 W in the cw regime and 16 W in the Q-switched regime with a slope efficiency exceeding 30%.

  18. Highly efficient passively Q-switched Yb:YAG microchip lasers under high intensity laser-diode pumping

    NASA Astrophysics Data System (ADS)

    Dong, J.; Wang, G. Y.; Cheng, Y.

    2013-03-01

    A highly efficient Cr4+:YAG passively Q-switched Yb:YAG microchip laser has been demonstrated at room temperature by high-brightness single-emitter laser-diode pumping. The maximum average output power of 1.53 W was obtained at the absorbed pump power of 3.5 W. The optical-to-optical efficiency was 44% with respect to the absorbed pump power. Laser pulses with a pulse width of 2.9 ns, pulse energy of 11.3 μJ, and peak power of 3.9 kW were obtained. The high pump power intensity from a high-brightness single-emitter laser-diode plays an important role in the alleviation of thermal effects and the efficient performance of Cr4+:YAG passively Q-switched Yb:YAG microchip lasers.

  19. High-power, mode-locking, external-cavity feedback diode-pumped laser based on SHG in PPKTP

    NASA Astrophysics Data System (ADS)

    Li, Wenchao; Liu, Zhengjun; Zhao, Hongdong; Li, Zhiquan

    2010-11-01

    The generation of high-power green laser is important for the numerous applications in industry, medicine, research and even entertainment. In addition, mode-locked lasers operating at {100 MHz repetition rate, are particularly attractive for nonlinear optics and spectroscopy. Characteristics of high-power, mode-locking green radiation obtained by Nd:YVO4 at 1064nm in the nonlinear crystals of PPKTP are studied. Two identical highly efficient diode-pumped laser heads placed in a plane-plane resonator are used for the input laser based on theoretically investigation of the thermally stable region of Nd:YVO4 rod. The PPKTP crystal of Brewster-cut is used in the external cavity configuration, the cavity losses is significantly smaller than for an antireflection(AR) coated crystal cut for normal incident, however, the effective nonlinearity is reduction. Frequency doubling nonlinear mirror(FDNLM) based on intensity dependent reflection in the laser cavity is used for the laser mode-locking. A stable green output power of 510W with pulse repetition rate of 100MHz and net conversion efficiency of η=50% at an input mode-matched power of 2KW are obtained. Meanwhile, thermal effects in the nonlinear crystal severely limit the efficiency of the laser configuration when using high pump power.

  20. Plasma and cyclotron frequency effects on output power of the plasma wave-pumped free-electron lasers

    NASA Astrophysics Data System (ADS)

    Zolghadr, S. H.; Jafari, S.; Raghavi, A.

    2016-05-01

    Significant progress has been made employing plasmas in the free-electron lasers (FELs) interaction region. In this regard, we study the output power and saturation length of the plasma whistler wave-pumped FEL in a magnetized plasma channel. The small wavelength of the whistler wave (in sub-μm range) in plasma allows obtaining higher radiation frequency than conventional wiggler FELs. This configuration has a higher tunability by adjusting the plasma density relative to the conventional ones. A set of coupled nonlinear differential equations is employed which governs on the self-consistent evolution of an electromagnetic wave. The electron bunching process of the whistler-pumped FEL has been investigated numerically. The result reveals that for a long wiggler length, the bunching factor can appreciably change as the electron beam propagates through the wiggler. The effects of plasma frequency (or plasma density) and cyclotron frequency on the output power and saturation length have been studied. Simulation results indicate that with increasing the plasma frequency, the power increases and the saturation length decreases. In addition, when density of background plasma is higher than the electron beam density (i.e., for a dense plasma channel), the plasma effects are more pronounced and the FEL-power is significantly high. It is also found that with increasing the strength of the external magnetic field frequency, the power decreases and the saturation length increases, noticeably.

  1. High-peak-power optically pumped AlGaInAs eye-safe laser at 500-kHz repetition rate with an intracavity diamond heat spreader

    NASA Astrophysics Data System (ADS)

    Chen, Y.-F.; Su, K. W.; Chen, W. L.; Huang, K. F.; Chen, Y. F.

    2012-08-01

    We report on a compact efficient high-repetition-rate (>100 kHz) optically pumped AlGaInAs nanosecond eye-safe laser at 1525 nm. A diamond heat spreader bonded to the gain chip is employed to improve the heat removal. At a pump power of 13.3 W, the average output power at a repetition rate 200 kHz is up to 3.12 W, corresponding to a peak output power of 560 W. At a repetition rate 500 kHz, the maximum average power and peak power are found to be 2.32 W and 170 W, respectively.

  2. Status of Kilowatt-Class Stirling Power Conversion Using a Pumped NaK Loop for Thermal Input

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Robbie, Malcolm G.

    2010-01-01

    Free-piston Stirling power conversion has been identified as a viable option for potential Fission Surface Power (FSP) systems on the Moon and Mars. Proposed systems consist of two or more Stirling convertors, in a dual-opposed configuration, coupled to a low-temperature uranium-dioxide-fueled, liquid-metal-cooled reactor. To reduce developmental risks associated with liquid-metal loop integration, a test rig has been built to evaluate the performance of a pair of 1-kW free-piston Stirling convertors using a pumped sodium-potassium (NaK) loop for thermal energy input. Baseline performance maps have been generated at the Glenn Research Center (GRC) for these 1-kW convertors operating with an electric heat source. Each convertor was then retrofitted with a custom-made NaK heater head and integrated into a pumped NaK system at the Marshall Space Flight Center (MSFC). This paper documents baseline testing at GRC as well as the progress made in integrating the Stirling convertors into the pumped NaK loop.

  3. A compact diode-pumped pulsed Nd:YAG slab laser based on a master oscillator power amplifier configuration

    NASA Astrophysics Data System (ADS)

    Maleki, A.; Kavosh Tehrani, M.; Saghafifar, H.; Moghtader Dindarlu, M. H.; Ebadian, H.

    2016-02-01

    In this paper, the design and construction of a pulsed Nd:YAG laser is described. The structure of this laser is based on a master oscillator power amplifier system. A master oscillator is an electro-optical Q-switched Nd:YAG rod laser. Face-pumping is used for the excitation of the slab structure, and a double-pass method is designed for the amplification stages. Two Nd:YAG zigzag slabs are utilized as power amplification stages in this laser. The laser diodes are stacked in a compact configuration and are used for rod and slabs pumping. The total pump energy in the amplifier stages is 3200 mJ at 808 nm. The output pulse energy achieved at 1064 nm is about 850 mJ of 10 ns pulse duration corresponding to 26.5% optical-to-optical conversion efficiency. Moreover, this laser can generate pulse energies around 430 mJ at 532 nm. The dependence of the output energy of MOPA and second harmonic generation operations on different pulse repetition rates (PRRs) from 1 to 100 Hz has been investigated. Experimental results show that the maximum fluctuations of the output energies are about 2.5 and 4% for 1064 and 532 nm, respectively.

  4. High-peak-power, high-repetition-rate LD end-pumped Nd:YVO4 burst mode laser

    NASA Astrophysics Data System (ADS)

    Pan, Hu; Yan, Renpeng; Fa, Xin; Yu, Xin; Ma, Yufei; Fan, Rongwei; Li, Xudong; Chen, Deying; Zhou, Zhongxiang

    2016-06-01

    A compact high-peak-power, high-repetition-rate burst mode laser is achieved by an acousto-optical Q-switched Nd:YVO4 1064 nm laser directly pumped at 878.6 nm. Pulse trains with 10-100 pulses are obtained using acousto-optical Q-switch at repetition rates of 10-100 kHz under a pulsed pumping with a 1 ms duration. At the maximum pump energy of 108.5 mJ, the pulse energy of 10 kHz burst mode laser reaches 44 mJ corresponding to a single pulse energy of 4.4 mJ and an optical-to-optical efficiency of 40.5 %.The maximum peak power of ~468.1 kW at 10 kHz is obtained with a pulse width of 9.4 ns. The beam quality factor is measured to be M 2 ~1.5 and the pulse jitter is estimated to be less than 1 % in both amplitude and time region.

  5. High-peak-power, high-repetition-rate LD end-pumped Nd:YVO4 burst mode laser

    NASA Astrophysics Data System (ADS)

    Pan, Hu; Yan, Renpeng; Fa, Xin; Yu, Xin; Ma, Yufei; Fan, Rongwei; Li, Xudong; Chen, Deying; Zhou, Zhongxiang

    2016-04-01

    A compact high-peak-power, high-repetition-rate burst mode laser is achieved by an acousto-optical Q-switched Nd:YVO4 1064 nm laser directly pumped at 878.6 nm. Pulse trains with 10-100 pulses are obtained using acousto-optical Q-switch at repetition rates of 10-100 kHz under a pulsed pumping with a 1 ms duration. At the maximum pump energy of 108.5 mJ, the pulse energy of 10 kHz burst mode laser reaches 44 mJ corresponding to a single pulse energy of 4.4 mJ and an optical-to-optical efficiency of 40.5 %.The maximum peak power of ~468.1 kW at 10 kHz is obtained with a pulse width of 9.4 ns. The beam quality factor is measured to be M 2 ~1.5 and the pulse jitter is estimated to be less than 1 % in both amplitude and time region.

  6. Types of Breast Pumps

    MedlinePlus

    ... uses batteries or a cord plugged into an electrical outlet to power a small motorized pump that creates suction to ... pumping. Because these breast pumps rely on a power source, women who use ... situations when electricity or extra batteries may not be available. If ...

  7. 885-nm Pumped Ceramic Nd:YAG Master Oscillator Power Amplifier Laser System

    NASA Technical Reports Server (NTRS)

    Yu, Anthony

    2012-01-01

    The performance of a traditional diode pumped solid-state laser that is typically pumped with 808-nm laser diode array (LDA) and crystalline Nd:YAG was improved by using 885-nm LDAs and ceramic Nd:YAG. The advantage is lower quantum defect, which will improve the thermal loading on laser gain medium, resulting in a higher-performance laser. The use of ceramic Nd:YAG allows a higher Nd dopant level that will make up the lower absorption at the 885-nm wavelength on Nd:YAG. When compared to traditional 808-nm pump, 885-nm diodes will have 30% less thermal load (or wasted heat) and will thus see a similar percentage improvement in the overall laser efficiency. In order to provide a more efficient laser system for future flight missions that require the use of low-repetition- rate (pumping the Nd:YAG laser crystal. This pumping scheme has many potential advantages for improved reliability, efficiency, thermal management, contamination control, and mechanical flexibility. The advantages of using 885-nm pump diodes in Nd:YAG laser systems are numerous. The epitaxial structures of these 885-nm diodes are aluminum-free. There is a significant reduction in the thermal load generated from the Stokes shift or quantum defects. A Stokes shift is the energetic difference between the pump and laser photons. Pumping at a wavelength band closer to the lasing wavelength can reduce the thermal load by .30% compared to traditional pumping at 808 nm, and increase the optical- to-optical efficiency by the same factor. The slope efficiency is expected to increase with a reduction in the thermal load. The typical crystalline Nd:YAG can be difficult to produce with doping level >1% Nd. To make certain that the absorption at 885 nm is on the same par as the 808-nm diode, the Nd:YAG material needs to be doped with higher concentration of Nd. Ceramic Nd:YAG is the only material that can be tailored

  8. Design, development and testing of a solar-powered multi-family residential size prototype turbocompressor heat pump

    SciTech Connect

    1981-03-01

    A program described to design, fabricate, and conduct preliminary testing of a prototype solar-powered Rankine cycle turbocompressor heat pump module for a multi-family residential building is presented. A solar system designed to use the turbocompressor heat pump module including all of the subsystems required and the various system operating modes is described in Section I. Section II includes the preliminary design analyses conducted to select the heat pump module components and operating features, working fluid, configuration, size and performance goals, and estimated performance levels in the cooling and heating modes. Section III provides a detailed description of the other subsystems and components required for a complete solar installation. Using realistic performance and cost characteristics for all subsystems, the seasonal performance of the UTC heat pump is described in various US locations. In addition, the estimated energy savings and an assessment of the economic viability of the solar system is presented in Section III. The detailed design of the heat pump module and the arrangement of components and controls selected to conduct the laboratory performance tests are described in Section IV. Section V provides a description of the special laboratory test facility, including the subsystems to simulate the collectors and storage tanks for building load and ambient conditions and the instrumentation, monitoring, and data acquisition equipment. The test results and sample computer analyses and comparisons with predicted performance levels are presented in Section VI. Various appendices provide supplementary and background information concerning working fluid selection (A), configuration selection (B), capacity control concepts (C), building models (D), computer programs used to determine component and system performance and total system economics (E), and weather data (F).

  9. Sound Absorbers

    NASA Astrophysics Data System (ADS)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  10. A high-power diode-pumped Nd:YVO4 slab amplifier with a hybrid resonator

    NASA Astrophysics Data System (ADS)

    Mao, Y. F.; Zhang, H. L.; Yuan, J. H.; Hao, X. L.; Xing, J. C.; Xin, J. G.; Jiang, Y.

    2016-06-01

    We demonstrated a compact and efficient in-band diode-pumped Nd:YVO4 partially end-pumped slab (Innoslab) nanosecond amplifier based on a hybrid resonator. For the seeder source, a-6 W, 5 ns Q-switched laser with a repetition rate of 30 kHz was obtained with beam quality factors M 2  <  1.3 . A beam-shaping system consisting of cylindrical lenses was designed according to the different sizes of the active medium in two orthogonal directions. A maximum average output power of 77 W was obtained. The optical-to-optical efficiency was 27.9%. The beam quality factors M 2 in the unstable and stable directions were 1.52 and 1.36, respectively.

  11. Influence of operating temperature on the power, divergence, and stress-induced birefringence in solar-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Brauch, U.; Muckenschnabel, J.; Thompson, George A.; Bernstein, Hana; Yogev, Amnon; Reich, A.; Oron, Moshe

    1992-05-01

    The relative performance of solar-pumped Nd:YAG and Nd:Cr:GSGG lasers was evaluated at both 300 and 80 K. Measurements of the slope efficiency and the lasing threshold were made on several lasers containing these crystals. The stress-induced birefringence and the divergence were also studied. The measurements were used to calculate the values of the intrinsic efficiencies and the losses at both temperatures. The possible mechanisms for the observed temperature dependence are discussed. Due to the improved thermal conductivity of the laser crystals at low temperature, all lasers showed significantly improved performance at low temperature. Both the slope efficiencies and the thresholds improved by a factor of 2 to 3 on cooling. The absolute value of the beam quality, and its sensitivity to changes in the resonator configuration or pump power were significantly better at low temperature.

  12. Method for optical pumping of thin laser media at high average power

    DOEpatents

    Zapata, Luis E.; Beach, Raymond J.; Honea, Eric C.; Payne, Stephen A.

    2004-07-13

    A thin, planar laser material is bonded to a light guide of an index-matched material forming a composite disk. Diode array or other pump light is introduced into the composite disk through the edges of the disk. Pump light trapped within the composite disk depletes as it multi-passes the laser medium before reaching an opposing edge of the disk. The resulting compound optical structure efficiently delivers concentrated pump light and to a laser medium of minimum thickness. The external face of the laser medium is used for cooling. A high performance cooler attached to the external face of the laser medium rejects heat. Laser beam extraction is parallel to the heat flux to minimize optical distortions.

  13. High-power pulse repetitive HF(DF) laser with a solid-state pump generator

    NASA Astrophysics Data System (ADS)

    Velikanov, S. D.; Domazhirov, A. P.; Zaretskiy, N. A.; Kazantsev, S. Yu; Kononov, I. G.; Kromin, A. A.; Podlesnykh, S. V.; Sivachev, A. A.; Firsov, K. N.; Kharitonov, S. V.; Tsykin, V. S.; Shchurov, V. V.; Yutkin, I. M.

    2015-11-01

    Operation of a repetitively pulsed electric-discharge HF(DF) laser with an all-solid-state pump generator based on FID switches is demonstrated. The energy stored in the pump generator capacitors was 880 J at an open-circuit voltage of 240 kV and a discharge pulse repetition rate of 25 Hz. The specific energy extractions were 3.8 and 3.4 J L-1 for the HF and DF lasers, respectively. The possibilities of improving the output laser characteristics are discussed.

  14. Multiwatt continuous wave Nd:KGW laser with hot-band diode pumping.

    PubMed

    Talukder, Rubel Chandra; Eibna Halim, Md Zubaer; Waritanant, Tanant; Major, Arkady

    2016-08-15

    We have demonstrated what we believe is the first continuous wave neodymium-doped potassium gadolinium tungstate crystal (Nd:KGW) laser with hot-band diode pumping at ∼910  nm. This pumping wavelength reduced the quantum defect by >46% as compared to conventional ∼810  nm pumping and resulted in significantly lower thermal lensing. The laser produced 2.9 W of average output power at 1067 nm in a diffraction-limited beam for an absorbed pump power of 8.3 W. The slope efficiency and optical-to-optical efficiency were found to be 43% and 35%, respectively. Significant reduction of quantum defect offered by this pumping wavelength and availability of suitable high-power laser diodes opens up an attractive way to further power and efficiency scaling of Nd:KGW lasers. PMID:27519095

  15. Heat cascading regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  16. Passively Q-switched 1617-nm polycrystalline ceramic Er:YAG laser using a Cr:ZnSe saturable absorber

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqi; Shen, Deyuan; Huang, Haitao; Liu, Jun; Zhang, Jian; Tang, Dingyuan; Fan, Dianyuan

    2015-08-01

    We report on a passively Q-switched polycrystalline ceramic Er:YAG laser by using a Cr:ZnSe crystal as a saturable absorber. When pumped by a 1532-nm Er-, Yb-doped fiber laser with the maximum power of 12.4 W, the laser yielded pulses of 28.8 ns duration at 1617 nm by using a saturable absorber with an initial transmission of 80 %. The corresponding peak power was up to 11.3 kW at a repetition rate of 2.17 kHz. The dependence of the pulse duration and repetition rate on the pump power was experimentally studied. The numerical and experimental results both show that the pulse duration was mainly determined by the initial transmission of the saturable absorber and slightly affected by the transmission of the output coupler. At last, we give some prospects for further narrowing down the pulse duration.

  17. 46 CFR 182.520 - Bilge pumps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (incorporated by reference; see 46 CFR 175.600); (2) The pump is used to dewater not more than one watertight... passengers Length of vessel Bilge pumps required Min. capacity required per pump ltrs/min (gal/min) Any... capacity, a power bilge pump may also serve as a fire pump. (d) Where two fixed power bilge pumps...

  18. Simultaneous triple 914 nm, 1084 nm, and 1086 nm operation of a diode-pumped Nd:YVO4 laser

    NASA Astrophysics Data System (ADS)

    Lü, Yanfei; Xia, Jing; Liu, Huilong; Pu, Xiaoyun

    2014-10-01

    We report a diode-pumped continuous-wave (cw) triple-wavelength Nd:YVO4 laser operating at 914, 1084, and 1086 nm. A theoretical analysis has been introduced to determine the threshold conditions for simultaneous triple-wavelength laser. Using a T-shaped cavity, we realized an efficient triple-wavelength operation at 4F3/2→4I9/2 and 4F3/2→4I11/2 transitions for Nd:YVO4 crystal, simultaneously. At an absorbed pump power of 16 W (or 25 W of incident pump power), the maximum output power was 2.3 W, which included 914 nm, 1084 nm, and 1086 nm three wavelengths, and the optical conversion efficiency with respect to the absorbed pump power was 14.4%.

  19. Austin Energy: Pumping System Improvement Project Saves Energy and Improves Performance at a Power Plant

    SciTech Connect

    2010-06-25

    This two-page performance spotlight describes how, in 2004, Austin Energy (the electric utility for the city of Austin, Texas) began saving about $1.2 million in energy and maintenance costs annually as a direct result of a pumping system efficiency proj

  20. Austin Energy: Pumping System Improvement Project Saves Energy and Improves Performance at a Power Plant

    SciTech Connect

    2010-06-25

    This two-page performance spotlight describes how, in 2004, Austin Energy (the electric utility for the city of Austin, Texas) began saving about $1.2 million in energy and maintenance costs annually as a direct result of a pumping system efficiency project.

  1. 250 W average power, 100 kHz repetition rate cryogenic Yb:YAG amplifier for OPCPA pumping.

    PubMed

    Zapata, L E; Reichert, F; Hemmer, M; Kärtner, F X

    2016-02-01

    A cryogenically cooled, bulk Yb:YAG, four-pass amplifier delivering up to 250 W average power at 100 kHz repetition rate is reported. The 2.5 mJ amplified optical pulses show a sub-20 ps duration before temporal compression and a spectrum supporting a transform-limited duration of 3.6 ps. The power instabilities were measured to be <0.5% rms over 30 min at full power, and the spatial intensity profile showed a flat-top distribution and near diffraction-limited beam quality. This compact amplifier is an ideal source for pumping either near-IR or mid-IR optical parametric chirped pulse amplifiers. PMID:26907405

  2. Scaling c-w electron-beam-pumped rare gas lasers to ultrahigh average power. Final report, 16 May-15 Nov 90

    SciTech Connect

    Not Available

    1991-04-11

    The overall objective of this program is to demonstrate the feasibility of efficiently scaling Ar:Xe lasers to ultra-high average power levels for strategic defense applications. The contractor has experimentally verified that the Ar:Xe laser system, which operates at near-IR wavelengths (1.73 micrometers), can achieve laser efficiencies of 4% with electron beam pumping at pump power densities as low as 10 watts/cc. This new efficient electron beam pumping regime promises cost-effective scaling of Ar:Xe laser systems to multi-megawatt average power levels while maintaining high electrical efficiency (4-6%) and near-diffraction-limited beam quality. In the Phase II effort, detailed experiments will be performed on an electron beam pumped Ar:Xe laser with a closed cycle flow loop at pump power densities of 10-20 W/cc. The objective of these experiments is to validate methods for correction and control of the optical distortions resulting from experiments is to validate methods for correction and control of the optical distortions resulting from CW pumping. Control of thermal distortions will be achieved by optimally contouring the spatial profile of electron beam power deposition in the active volume. With the optimal deposition profile, higher order optical distortions will be negligible and a diffraction limited beam will be obtained after tilt and focus corrections are made. These corrections can be made by a simple local loop by an adaptive optics system in the beam train.

  3. Advanced high-temperature electromagnetic pump

    NASA Technical Reports Server (NTRS)

    Gahan, J. W.; Powell, A. H.

    1972-01-01

    Three phase helical, electromagnetic induction pump for use as boiler feed pump in potassium Rankine-cycle power system is described. Techniques for fabricating components of pump are discussed. Specifications of pump are analyzed.

  4. Improving pumping system efficiency at coal plants

    SciTech Connect

    Livoti, W.C.; McCandless, S.; Poltorak, R.

    2009-03-15

    The industry must employ ultramodern technologies when building or upgrading power plant pumping systems thereby using fuels more efficiently. The article discusses the uses and efficiencies of positive displacement pumps, centrifugal pumps and multiple screw pumps. 1 ref., 4 figs.

  5. Kilohertz high power extracavity KGW yellow raman lasers based on pulse LD side-pumped ceramic Nd: YAG

    NASA Astrophysics Data System (ADS)

    Bai, Y.; Chen, X. M.; Guo, J. X.; Zhang, H. L.; Bai, J. T.; Ren, Z. Y.

    2012-03-01

    We report an efficient operation of a kilohertz nanosecond extracavity KGd(WO4)2 (KGW) crystal Raman yellow laser, which is pumped by a 532 nm lasers based on pulse laser diode (LD) side-pumped ceramic Nd: YAG, BBO electro-optical Q-switched and LBO crystal extracavity frequency doubling. With the 5 W, 10 ns and 1 kHz output power pumped at 532 nm, we obtained 2.58 W, 7.4 ns, 1 kHz second Stokes Raman laser output at 579.54 nm for 768 cm-1 Raman shift of KGW crystal, corresponding to a conversion efficiency of 51.4%. By changing the KGW crystal orientation, we further obtained 3.18 W, 7.8 ns, 1 kHz Raman pulses at 588.33 nm for 901 cm-1 Raman shift, corresponding to a conversion efficiency of 63.3%. The beam quality factors M2 of 579.54 and 588.33 nm were ( M {/x-579.54 2} = 5.829, M {/y-579.54 2} = 6.336) and ( M {/x-588.33 2} = 6.405, M {/y-588.33 2} = 6.895), respectively.

  6. Operational performance of the photovoltaic-powered grain mill and water pump at Tangaye, Burkina Faso (formerly Upper Volta)

    NASA Technical Reports Server (NTRS)

    Martz, J. E.; Roberts, A. F.

    1985-01-01

    A photovoltaic (PV) system powering a grain mill and water pump was installed in the remote African village of Tangaye, Burkina Faso (formerly Upper Volta) under the sponsorship of the U.S. Agency for International Development (AID) and by the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) in early 1979. The presence reports covers the second two years of operation from April 1981 through June 1983. During this time, the grain mill and water pump were operational 96 and 88 percent of the time respectively, and the PV system generated sufficient electricity to enable the grinding of about 111 metric tons of finely ground flow and the pumping of over 5000 cm sq of water from the 10 m deep well. The report includes a description of the current configuration of the system, a review of system performance, a discussion of the socioeconomic impact of the system on the villagers and a summary of results and conclusions covering the entire four-year period.

  7. Power deposition in He from the volumetric He-3/n,p/H-3 reaction. [for direct nuclear pumped lasers

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Winters, P. A.

    1977-01-01

    Calculations are presented in this paper which show the amount of power that can be expected to be deposited in He-3 for typical direct nuclear-pumped lasers presently in use. The calculations were performed taking into consideration the cylindrical geometry of the system, the depletion of the thermal flux across the tube cross section, and the energy loss of the protons to the cell walls. If a laser efficiency of 1% is assumed, the results indicate a steady-state laser output of 12.5 kW from a volume of 152.6 cu cm or 82 W/cu cm can be achieved.

  8. Molecular basis for inhibition of AcrB multidrug efflux pump by novel and powerful pyranopyridine derivatives.

    PubMed

    Sjuts, Hanno; Vargiu, Attilio V; Kwasny, Steven M; Nguyen, Son T; Kim, Hong-Suk; Ding, Xiaoyuan; Ornik, Alina R; Ruggerone, Paolo; Bowlin, Terry L; Nikaido, Hiroshi; Pos, Klaas M; Opperman, Timothy J

    2016-03-29

    TheEscherichia coliAcrAB-TolC efflux pump is the archetype of the resistance nodulation cell division (RND) exporters from Gram-negative bacteria. Overexpression of RND-type efflux pumps is a major factor in multidrug resistance (MDR), which makes these pumps important antibacterial drug discovery targets. We have recently developed novel pyranopyridine-based inhibitors of AcrB, which are orders of magnitude more powerful than the previously known inhibitors. However, further development of such inhibitors has been hindered by the lack of structural information for rational drug design. Although only the soluble, periplasmic part of AcrB binds and exports the ligands, the presence of the membrane-embedded domain in AcrB and its polyspecific binding behavior have made cocrystallization with drugs challenging. To overcome this obstacle, we have engineered and produced a soluble version of AcrB [AcrB periplasmic domain (AcrBper)], which is highly congruent in structure with the periplasmic part of the full-length protein, and is capable of binding substrates and potent inhibitors. Here, we describe the molecular basis for pyranopyridine-based inhibition of AcrB using a combination of cellular, X-ray crystallographic, and molecular dynamics (MD) simulations studies. The pyranopyridines bind within a phenylalanine-rich cage that branches from the deep binding pocket of AcrB, where they form extensive hydrophobic interactions. Moreover, the increasing potency of improved inhibitors correlates with the formation of a delicate protein- and water-mediated hydrogen bond network. These detailed insights provide a molecular platform for the development of novel combinational therapies using efflux pump inhibitors for combating multidrug resistant Gram-negative pathogens. PMID:26976576

  9. An improved absorption generator for solar-thermal powered heat pumps. Part 2: Energy and economics

    SciTech Connect

    Fineblum, S.

    1997-12-31

    Solar heated absorption chiller installations have been very expensive for their rating. To enhance collector thermal efficiency the liquid flowing within the collectors must be kept as cool as possible. However, there is also a need to operate the absorption reported earlier. The compromise usually results in poor collector efficiency as well as a relatively poor specific chiller effect. The proposed vortex generator permits a heat pump to operate efficiently with relatively low temperature solar heated fluid (70--80 C). As a result, the collectors are cooler and more efficient. As noted in Part 1, the specific heat pumping capacity is about 27% greater than conventional systems operating at the same reduced generator temperatures. Therefore, a smaller, less expensive chiller is required. The reduced investment in solar arrays and absorption chillers is estimated along with a range of paybacks.

  10. An improved absorption generator for solar-thermal powered heat pumps. Part 1: Feasibility

    SciTech Connect

    Fineblum, S.

    1997-12-31

    Solar heated absorption chiller installations have been, typically, very expensive for their rating. The need to keep the liquid flowing within the collectors as cool as possible to enhance collector thermal efficiency, conflicts with the need to operate the absorption chiller at a higher temperature. The compromise usually results in poor collector efficiency as well as a relatively poor specific chiller effect. The proposed vortex generator permits a heat pump to operate efficiently with relatively low temperature solar heated fluid (70--80 C). As a result, the collectors are cooler and much more efficient. In addition, the specific heat pumping capacity is about 27% greater than conventional systems operating at the same reduced generator temperatures and, therefore, a smaller chiller is required. The economic consequences of these benefits will be presented in Part 2.

  11. Efficient single-pass resonantly-pumped Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Elder, Ian; Kendall, Timothy

    2012-09-01

    A simple scheme for efficient generation of two micron laser radiation is reported. Using a thulium fibre laser to pump a Q-switched Ho:YAG laser 31.7 W of average output power is achieved with an M2 of 1.5 (an optical-to-optical conversion efficiency of 67% in terms of absorbed pump power) at a wavelength of 2.1 μm. A single-pass pump geometry is used, eliminating the risk of feedback of unabsorbed light into the fibre laser.

  12. Room-temperature, continuous-wave, 946-nm Nd:YAG laser pumped by laser-diode arrays and intracavity frequency doubling to 473 nm

    SciTech Connect

    Risk, W.P.; Lenth, W.

    1987-12-01

    We report the use of GaAlAs laser-diode arrays to pump a cw Nd:YAG laser operating on the 946-nm /sup 4/F/sub 3/2/..-->../sup 4/I/sub 9/2/ transition. At room temperature, the lasing threshold was reached with 58 mW of absorbed pump power, and, with 175 mW of absorbed pump power, 42 mW of output power at 946 nm was obtained in a TEM/sub 00/ mode by using 0.7% output coupling. In addition, pumping with an infrared dye laser operating in a pure TEM/sub 00/ mode was used to investigate the effects of reabsorption loss that are characteristic of the 946-nm laser transition. LiIO/sub 3/ was used as an intracavity doubling crystal, and 100 ..mu..W of blue light was generated by using diode-laser pumping in a nonoptimized cavity.

  13. High-power and highly efficient diode-cladding-pumped holmium-doped fluoride fiber laser operating at 2.94 microm.

    PubMed

    Jackson, Stuart D

    2009-08-01

    A high-power diode-cladding-pumped Ho(3+), Pr(3+)-doped fluoride glass fiber laser is demonstrated. The laser produced a maximum output power of 2.5 W at a slope efficiency of 32% using diode lasers emitting at 1,150 nm. The long-emission wavelength of 2.94 microm measured at maximum pump power, which is particularly suited to medical applications, indicates that tailoring of the proportion of Pr(3+) ions can provide specific emission wavelengths while providing sufficient de-excitation of the lower laser level. PMID:19649086

  14. Future directions in 980-nm pump lasers: submarine deployment to low-cost watt-class terrestrial pumps

    NASA Astrophysics Data System (ADS)

    Gulgazov, Vadim N.; Jackson, Gordon S.; Lascola, Kevin M.; Major, Jo S.; Parke, Ross; Richard, Tim; Rossin, Victor V.; Zhang, Kai

    1999-09-01

    The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modern telecommunication systems originates from optical amplifiers. In addition, modern optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems. Erbium-doped amplifiers currently dominate optical amplifier usage. These amplifiers absorb pump light at 980 nm and/or 1480 nm, and achieve gain at wavelengths around 1550 nm. 980 nm pumps achieve better noise figures and are therefore used for the amplification of small signals. Due to the quantum defect, 1480 nm lasers deliver more signal photon per incident photon. In addition, 1480 nm lasers are less expensive than 980 nm lasers. Thus, 1480 nm pump lasers are used for amplification in situations where noise is not critical. The combination of these traits leads to the situation where many amplifiers contain 980 nm lasers to pump the input section of the Er- doped fiber with 1480 nm lasers being used to pump the latter section of Er fiber. This can be thought of as using 980 nm lasers to power an optical pre-amplifier with the power amplification function being pump with 1480 nm radiation. This paper will focus on 980 nm pump lasers and the impact that advances in 980 nm pump technology will have on optical amplification systems. Currently, 980 nm technology is rapidly advancing in two areas, power and reliability. Improving reliability is becoming increasingly important as amplifiers move towards employing more pump lasers and using these pump lasers without redundancy

  15. Compact high power mid-infrared optical parametric oscillator pumped by a gain-switched fiber laser with "figure-of-h" pulse shape.

    PubMed

    Jiang, Peipei; Chen, Tao; Wu, Bo; Yang, Dingzhong; Hu, Chengzhi; Wu, Pinghui; Shen, Yonghang

    2015-02-01

    We demonstrate a compact high power mid-infrared (MIR) optical parametric oscillator (OPO) pumped by a gain-switched linearly polarized, pulsed fiber laser. The gain-switched fiber laser was constructed with a piece of Yb doped polarization maintaining (PM) fiber, a pair of fiber Bragg gratings written into the matched passive PM fiber and 6 pigtailed pump laser diodes working at 915 nm with 30 W output peak power each. By modulating the pulse width of the pump laser diode, simple pedestal-free pulse shape or pedestal-free trailing pulse shape ("figure-of-h" as we call it) could be achieved from the gain-switched fiber laser. The laser was employed as the pump of a two-channel, periodically poled magnesium oxide lithium niobate-based OPO system. High power MIR emission was generated with average output power of 5.15 W at 3.8 μm channel and 8.54 W at 3.3 μm channel under the highest pump power of 45 W. The corresponding pump-to-idler conversion efficiency was computed to be 11.7% and 19.1%, respectively. Experimental results verify a significant improvement to signal-to-idler conversion efficiency by using "figure-of-h" pulses over simple pedestal-free pulses. Compared to the master oscillator power amplifier (MOPA) fiber laser counterpart, the presented gain switched fiber laser is more attractive in OPO pumping due to its compactness and simplicity which are beneficial to construction of OPO systems for practical MIR applications. PMID:25836126

  16. [A novel compact digital amplifier to control a medical equipment (Graseby 3500 pump) by Macintosh computer without external power supply].

    PubMed

    Nakao, M

    1998-05-01

    Most medical equipments now incorporate a digital RS-232 C interface, which enables to log data and/or control equipments by computers. Although the standard voltage specification of RS-232 C is minimum +/- 3 volts, certain devices, such as Graseby syringe driven pump model 3500 (U.K.), need higher voltage than the standard to reduce the risk of electromagnetic interference. Since the output voltage of serial port of Macintosh (Apple Computer Inc.) computer and other portable computers is around +/- 5 volts, an additional voltage amplifier is necessary to control such external devices. A compact digital signal amplifier was developed by using a general RS-232 C driver IC (MAX 232 E, Maxim USA). Bulky external power supply could be eliminated, because power was obtained through digital signal lines themselves. PMID:9621678

  17. Edge-facet pumped, multi-aperture, thin-disk laser geometry for very high average power output scaling

    DOEpatents

    Zapata, Luis E.

    2004-12-21

    The average power output of a laser is scaled, to first order, by increasing the transverse dimension of the gain medium while increasing the thickness of an index matched light guide proportionately. Strategic facets cut at the edges of the laminated gain medium provide a method by which the pump light introduced through edges of the composite structure is trapped and passes through the gain medium repeatedly. Spontaneous emission escapes the laser volume via these facets. A multi-faceted disk geometry with grooves cut into the thickness of the gain medium is optimized to passively reject spontaneous emission generated within the laser material, which would otherwise be trapped and amplified within the high index composite disk. Such geometry allows the useful size of the laser aperture to be increased, enabling the average laser output power to be scaled.

  18. Continuous-wave seeded mid-IR parametric system pumped by the high-average-power picosecond Yb:YAG thin-disk laser

    NASA Astrophysics Data System (ADS)

    Novák, Ondřej; Smrž, Martin; Miura, Taisuke; Turčičová, Hana; Endo, Akira; Mocek, Tomáś

    2015-05-01

    Mid-IR wavelength range offers variety of interesting applications. Down-conversion in the optical parametric devices is promising to generate high average power mid-IR beam due to inherently low thermal load of the nonlinear crystals if a powerful and high quality pump beam is available. We developed 100 kHz pump laser of 100-W level average power. The stretched pulses of Yb-fiber laser oscillator at 1030 nm wavelength are injected into the regenerative amplifier with an Yb:YAG thin-disk. Diode pumping at zero phonon line at wavelength of 969 nm significantly reduces its thermal load and increases conversion efficiency and stability. We obtained the beam with power of 80 W and 2 ps compressed pulsewidth. We are developing a watt level mid-IR picosecond light source pumped by a beam of the thin disk regenerative amplifier. Part of the beam pumps PPLN, which is seeded by a continuous wave laser diode at 1.94 μm to decrease the generation threshold and determine the amplified spectrum. The 3 W pumping gave output of 30 mW, which is by up to two orders higher compared to unseeded operation. The gain of about 107 was achieved in the PPLN in the temporal window of the pump pulse. The spectrum and beam of the generated idler pulses in the mid-IR was measured. We obtained an amplified signal from the second stage with the KTP crystal. We expect watt level mid-IR output for initial 50-W pumping. The generation of longer wavelengths is discussed.

  19. Highly efficient continuous-wave intracavity frequency-doubled Nd:YVO4-LBO laser at 457 nm under diode pumping into the emitting level 4F3/2

    NASA Astrophysics Data System (ADS)

    Lü, Y. F.; Zhang, X. H.; Yin, X. D.; Xia, J.; Zhang, A. F.; Lin, J. Q.

    2010-04-01

    The continuous-wave high efficiency laser emission of Nd:YVO4 at the fundamental wavelength of 914 nm and its 457 nm second harmonic obtained by intracavity frequency doubling with an LBO nonlinear crystal is investigated under pumping by diode laser at 880 nm into emitting level 4F3/2. 6.5 W at 457 nm with M 2=1.8 was obtained from a 5-mm-thick 0.4 at.% Nd:YVO4 laser medium and a 15-mm-long LBO nonlinear crystal in a Z-type cavity for 18.6 W absorbed pump power. An optical-to-optical efficiency with respect to the absorbed pump power was 0.35. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing level 4F5/2, are given in order to prove the advantages of the 880 nm wavelength pumping.

  20. Core-pumped single-frequency fiber amplifier with an output power of 158  W.

    PubMed

    Theeg, Thomas; Ottenhues, Christoph; Sayinc, Hakan; Neumann, Jörg; Kracht, Dietmar

    2016-01-01

    Single-frequency laser sources at a wavelength of 1 μm are typically scaled in power with Ytterbium-doped double-clad fiber amplifiers. The main limitations are stimulated Brillouin scattering, transversal mode instabilities and, from a technical point of view, the degree of fiber integration for a rugged setup. Addressing these limitations, we propose an alternative high-power single-frequency amplifier concept based on core pumping. A nonplanar ring oscillator with 2 W of output power at 1 kHz spectral linewidth was scaled by a fiber amplifier up to a power of 158 W without any indication of stimulated Brillouin scattering-using a standard Ytterbium-doped single-mode fiber with a mode field area of only ∼100  μm2. A short active fiber length and a strong temperature gradient along the gain fiber yield to efficient suppression of stimulated Brillouin scattering. For deeper understanding of the Brillouin scattering mitigation mechanism, we studied the Brillouin gain spectra with a Fabry-Perot interferometer at different output power levels of the fiber amplifier. PMID:26696145

  1. Aging and service wear of auxiliary feedwater pumps for PWR nuclear power plants

    SciTech Connect

    Greenstreet, W.L.

    1989-01-01

    This paper describes investigations on auxiliary feedwater pumps being done under the Nuclear Plant Aging Research (NPAR) Program. Objectives of these studies are: to identify and evaluate practical, cost-effective methods for detecting, monitoring, and assessing the severity of time-dependent degradation (aging and service wear); recommend inspection and maintenance practices; establish acceptance criteria; and help facilitate use of the results. Emphasis is given to identifying and assessing methods for detecting failure in the incipient stage and to developing degradation trends to allow timely maintenance, repair or replacement actions. 3 refs.

  2. Liquid Hydrogen Absorber for MICE

    SciTech Connect

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  3. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  4. Liquid metal enabled pump

    PubMed Central

    Tang, Shi-Yang; Khoshmanesh, Khashayar; Sivan, Vijay; Petersen, Phred; O’Mullane, Anthony P.; Abbott, Derek; Mitchell, Arnan; Kalantar-zadeh, Kourosh

    2014-01-01

    Small-scale pumps will be the heartbeat of many future micro/nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics. PMID:24550485

  5. High power monolithically integrated all-fiber laser design using single-chip multimode pumps for high reliability operation

    NASA Astrophysics Data System (ADS)

    Faucher, Mathieu; Villeneuve, Eric; Sevigny, Benoit; Wetter, Alexandre; Perreault, Roger; Lizé, Yannick Keith; Holehouse, Nigel

    2008-02-01

    We present an all-fiber monolithically integrated fiber laser based on a custom tapered fused bundle pump combiner with 32 inputs ports connected to a double clad gain fiber. The pump combiner is designed to provide high isolation between signal and pumps fibers providing intrinsic pump protection. This configuration can generate more than 100W of continuous wave (CW) laser light using single-chip multimode pumps enabling long term reliability.

  6. Aging of turbine drives for safety-related pumps in nuclear power plants

    SciTech Connect

    Cox, D.F.

    1995-06-01

    This study was performed to examine the relationship between time-dependent degradation and current industry practices in the areas of maintenance, surveillance, and operation of steam turbine drives for safety-related pumps. These pumps are located in the Auxiliary Feedwater (AFW) system for pressurized-water reactor plants and in the Reactor Core Isolation Cooling and High-Pressure Coolant Injection systems for boiling-water reactor plants. This research has been conducted by examination of failure data in the Nuclear Plant Reliability Data System, review of Licensee Event Reports, discussion of problems with operating plant personnel, and personal observation. The reported failure data were reviewed to determine the cause of the event and the method of discovery. Based on the research results, attempts have been made to determine the predictability of failures and possible preventive measures that may be implemented. Findings in a recent study of AFW systems indicate that the turbine drive is the single largest contributor to AFW system degradation. However, examination of the data shows that the turbine itself is a reliable piece of equipment with a good service record. Most of the problems documented are the result of problems with the turbine controls and the mechanical overspeed trip mechanism; these apparently stem from three major causes which are discussed in the text. Recent improvements in maintenance practices and procedures, combined with a stabilization of the design, have led to improved performance resulting in a reliable safety-related component. However, these improvements have not been universally implemented.

  7. Key techniques for space-based solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  8. Fuel savings with conventional hot water space heating systems by incorporating a natural gas powered heat pump. Preliminary project: Development of heat pump technology

    NASA Astrophysics Data System (ADS)

    Vanheyden, L.; Evertz, E.

    1980-12-01

    Compression type air/water heat pumps were developed for domestic heating systems rated at 20 to 150 kW. The heat pump is driven either by a reciprocating piston or rotary piston engine modified to operate on natural gas. Particular features of natural gas engines as prime movers, such as waste heat recovery and variable speed, are stressed. Two systems suitable for heat pump operation were selected from among five different mass produced car engines and were modified to incorporate reciprocating piston compressor pairs. The refrigerants used are R 12 and R 22. Test rig data transferred to field conditions show that the fuel consumption of conventional boilers can be reduced by 50% and more by the installation of engine driven heat pumps. Pilot heat pumps based on a 1,600 cc reciprocating piston engine were built for heating four two-family houses. Pilot pump operation confirms test rig findings. The service life of rotary piston and reciprocating piston engines was investigated. The tests reveal characteristic curves for reciprocating piston engines and include exhaust composition measurements.

  9. Apparatus for Pumping a Fluid

    NASA Technical Reports Server (NTRS)

    Boeyen, Robert Van; Reeh, Jonathan

    2013-01-01

    A fluid pump has been developed for mechanically pumped fluid loops for spacecraft thermal control. Lynntech's technology utilizes a proprietary electrochemically driven pumping mechanism. Conventional rotodynamic and displacement pumps typically do not meet the stringent power and operational reliability requirements of space applications. Lynntech's developmental pump is a highly efficient solid-state pump with essentially no rotating or moving components (apart from metal bellows).

  10. Four-Pass Coupler for Laser-Diode-Pumped Solid-State Laser

    NASA Technical Reports Server (NTRS)

    Coyle, Donald B.

    2008-01-01

    A four-pass optical coupler affords increased (in comparison with related prior two-pass optical couplers) utilization of light generated by a laser diode in side pumping of a solid-state laser slab. The original application for which this coupler was conceived involves a neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal slab, which, when pumped by a row of laser diodes at a wavelength of 809 nm, lases at a wavelength of 1,064 nm. Heretofore, typically, a thin laser slab has been pumped in two passes, the second pass occurring by virtue of reflection of pump light from a highly reflective thin film on the side opposite the side through which the pump light enters. In two-pass pumping, a Nd:YAG slab having a thickness of 2 mm (which is typical) absorbs about 84 percent of the 809-nm pump light power, leaving about 16 percent of the pump light power to travel back toward the laser diodes. This unused power can cause localized heating of the laser diodes, thereby reducing their lifetimes. Moreover, if the slab is thinner than 2 mm, then even more unused power travels back toward the laser diodes. The four-pass optical coupler captures most of this unused pump light and sends it back to the laser slab for two more passes. As a result, the slab absorbs more pump light, as though it were twice as thick. The gain and laser cavity beam quality of a smaller laser slab in conjunction with this optical coupler can thus be made comparable to those of a larger two-pass-pumped laser slab.

  11. All-solid-state dual end pumped Nd:YAG/LBO yellow green laser with 10.8 W output power at 561 nm

    NASA Astrophysics Data System (ADS)

    Zhu, P. F.; Zhang, C. M.; Song, P.; Bai, L.; Yao, Y.

    2015-04-01

    It is reported that the efficient and compact yellow green laser at 561 nm generated by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode pumped Nd:YAG laser on the 4 F 3/2 → 4 F 13/2 transition operated at 1123 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. With dual end pump configurations at total incident pump power of 40 W, as high as 10.8 W of CW output power at 561 nm is achieved with 20 mm long LBO. The optical-to-optical conversion efficiency is up to 27%, and the power stability in 8 h is better than 2.56%.

  12. All-solid-state dual end pumped YVO4:Nd/LBO blue laser with 21.8 W output power at 457 nm

    NASA Astrophysics Data System (ADS)

    Ling, Zhao; Yi, Yao; Yang, Zhao; Quan, Zheng

    2014-03-01

    It is reported the efficient compact deep-blue laser at 457 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode-pumped YVO4:Nd laser on the 4 F 3/2 → 4 I 9/2 transition at 914 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation (SHG) of the laser. With dual end pump configurations at total incident pump power of 60 W, as high as 21.8 W of CW output power at 457 nm is achieved with 20-mm-long LBO. The optical-to-optical conversion efficiency is up to 36.3%, and the power stability in 8 h is better than 2.36%.

  13. Diode-end-pumped passively mode-locked high-power Nd:YVO4 laser with a relaxed saturable Bragg reflector.

    PubMed

    Chen, Y F; Tsai, S W; Lan, Y P; Wang, S C; Huang, K F

    2001-02-15

    We demonstrate a high-power passively mode-locked Nd:YVO (4) laser that uses a saturable Bragg reflector (SBR) with strain relaxation. 23.5 W of average power with ~21.5-ps cw mode-locked pulse trains was generated at a 50-W pump power. Experimental results show that appropriate strain relaxation in the SBR makes the mode-locking operation less sensitive to temperature variation. PMID:18033546

  14. Estimation of absorbed radiation dose rates in wild rodents inhabiting a site severely contaminated by the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Kubota, Yoshihisa; Takahashi, Hiroyuki; Watanabe, Yoshito; Fuma, Shoichi; Kawaguchi, Isao; Aoki, Masanari; Kubota, Masahide; Furuhata, Yoshiaki; Shigemura, Yusaku; Yamada, Fumio; Ishikawa, Takahiro; Obara, Satoshi; Yoshida, Satoshi

    2015-04-01

    The dose rates of radiation absorbed by wild rodents inhabiting a site severely contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident were estimated. The large Japanese field mouse (Apodemus speciosus), also called the wood mouse, was the major rodent species captured in the sampling area, although other species of rodents, such as small field mice (Apodemus argenteus) and Japanese grass voles (Microtus montebelli), were also collected. The external exposure of rodents calculated from the activity concentrations of radiocesium ((134)Cs and (137)Cs) in litter and soil samples using the ERICA (Environmental Risk from Ionizing Contaminants: Assessment and Management) tool under the assumption that radionuclides existed as the infinite plane isotropic source was almost the same as those measured directly with glass dosimeters embedded in rodent abdomens. Our findings suggest that the ERICA tool is useful for estimating external dose rates to small animals inhabiting forest floors; however, the estimated dose rates showed large standard deviations. This could be an indication of the inhomogeneous distribution of radionuclides in the sampled litter and soil. There was a 50-fold difference between minimum and maximum whole-body activity concentrations measured in rodents at the time of capture. The radionuclides retained in rodents after capture decreased exponentially over time. Regression equations indicated that the biological half-life of radiocesium after capture was 3.31 d. At the time of capture, the lowest activity concentration was measured in the lung and was approximately half of the highest concentration measured in the mixture of muscle and bone. The average internal absorbed dose rate was markedly smaller than the average external dose rate (<10% of the total absorbed dose rate). The average total absorbed dose rate to wild rodents inhabiting the sampling area was estimated to be approximately 52 μGy h(-1) (1.2 mGy d(-1)), even 3 years after

  15. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser

    PubMed Central

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-01-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900–2000 nm. PMID:27416893

  16. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser

    NASA Astrophysics Data System (ADS)

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-07-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900–2000 nm.

  17. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser.

    PubMed

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-01-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900-2000 nm. PMID:27416893

  18. Power scaling of mini-bar-based high-power 780-980nm pump modules at Spectra-Physics

    NASA Astrophysics Data System (ADS)

    Liu, Daming; Cutillas, Serge; Jin, Xu; Park, Sang-Ki; Johnson, Kelly; Li, Hanxuan; Truchan, Tom; Wolak, Ed; Towe, Terry; Chyr, Irving; Miller, Robert; Meissner, Arne; Lenarduzzi, Dino; Bullock, Robert; Mott, Jeff; Harrison, James

    2009-02-01

    Continued advances in high power diode laser technology enable new applications and enhance existing ones. Recently, mini-bar based modules have been demonstrated which combine the advantages of independent emitter failures previously shown in single-stripe architectures with the improved brightness retention enabled by multi-stripe architectures. In this work we highlight advances in a family of compact, environmentally rugged mini-bar based fiber coupled Orion modules. Advances in PCE (power conversion efficiency) and reliable operating power from a 9xx nm wavelength unit are shown from such modules. Additionally, highly reliable fiber coupled operation and performance data is demonstrated in other wavelengths in the 780 - 980 nm range. Data demonstrating the scaling this technology to 25W and higher power levels will be given.

  19. Intracavity absorption with a continuous wave dye laser: quantification for a narowband absorber

    SciTech Connect

    Brobst, W.D.; Allen J.E. Jr.

    1987-09-01

    Although it is recognized as a very sensitive detection technique, the general application of intracavity absorption to areas such as chemical kinetics and photochemistry has been somewhat limited. Concerns are frequently expressed about the nonlinear nature, experimental difficulty, and reliability of the technique. To allay some of these objections, the dependence of intracavity absorption on factors such as transition strength, concentration, absorber path length, and pump power has been investigated experimentally for a cw dye laser with a narrowband absorber (NO/sub 2/). For this case a Beer-Lambert type relationship has been confirmed over a useful range of these parameters. The extent of intracavity absorption was quantitatively measured directly from the dye laser spectral profiles and, when compared to extracavity measurements, indicated enhancements as high as 12,000 for pump powers near lasing threshold. By defining an intracavity absorption coefficient, it was possible to demonstrate the reliability of the method by obtaining accurate transition strength ratios.

  20. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    NASA Astrophysics Data System (ADS)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  1. Different cooling configurations for a high average power longitudinally diode-pumped Yb:YAG amplifier.

    PubMed

    Yu, Haiwu; Bourdet, Gilbert

    2006-08-20

    We analyze the temperature distribution in several Yb:YAG longitudinally pumped amplifier crystals by using various cooling configurations. The crystal designs are (i) a composite crystal made of a thin sheet of high-doped Yb:YAG bonded on a bulk piece of undoped YAG and (ii) a thick piece of low-doped Yb:YAG crystal. The cooling configurations investigated here include those both from the rear face or from the rear and side faces together. In every case we determine the average temperature rise, the longitudinal and radial temperature gradient, and the resulting crystal bending and optical phase distortion. We optimize the best cooling configuration and crystal design by compromising the average temperature, thermodeformation, and optical phase distortion. The experimental results also indicate that a thin sheet of gain medium (1.6 mm thick at 10 at. % doping) suffers from a notable bending deformation, which results in an unexpected decrease of the output energy. PMID:16892125

  2. Development of Fuel Cell Co-generation System with Heat-pump System in Consideration of Transient Response of Electric Power

    NASA Astrophysics Data System (ADS)

    Obara, Shinya; Kudo, Kazuhiko

    The transient response characteristics of electric power output of the fuel cell system for individual houses were investigated, and relation between system control parameters and transient response characteristics were clarified. Furthermore, the transient response characteristics of coefficient of performance (COP) and electric power output of the system which makes heat pump an auxiliary heat source were investigated. Moreover, the relation between COP of heat pump and the transient response characteristics of the system were considered. Analysis of operation cost of system components and annual operation cost balance was performed supposing introducing a fuel cell co-generation system installs to individual house in Sapporo and Tokyo. Relation between COP of heat pump and operation cost, relation of reformer time-constant and operation cost, operation cost of the system with town gas boiler instead of heat pump, were investigated. The fuel cell cogeneration system introduced into Tokyo does not have the necessity of using heat pump and boiler, and it is thought that energy demand is filled with installing a thermal storage tank of small capacity. Moreover, it is more advantageous for operation cost to introduce a town gas boiler rather than introduces about COP=2. 0 heat pump into Sapporo.

  3. Preliminary design study of Underground Pumped Hydro and compressed-air energy storage in hard rock. Volume 8: Design approaches. UPH, Appendix D: Power plant

    NASA Astrophysics Data System (ADS)

    1981-06-01

    Studies were undertaken to determine power plant arrangements for a single stage reversible pump turbine two step underground pumped hydro (UPH) installation and for a multi-stage reversible pump turbine single step (MSRPT) UPH installation. Arrangements consist of: the underground powerhouses; transformer galleries; associated mechanical and electrical equipment; the administration and control building; hoist head frames; the access; draft tube and bus tunnels; and the switchyard. Primary considerations including the number and size of pump turbine and motor generator units, starting methods, transformers, high voltage connections, geotechnical and construction aspects and safety were studied. A feasibility analysis to minimize costs was conducted. The study led to the selection of suitable equipment and layouts for the powerhouses, transformer galleries, and associated facilities. The material presented and also the cost estimates are based on the requirements for a 2000 MW plant providing 20,000 MWh of storage with a nominal head of 4600 ft.

  4. Apparatus and method for servicing an elongated suspended pump motor in an electric power plant with limited access

    DOEpatents

    Chavez, R.V.; Ekeroth, D.E.; Johnson, F.T.; Matusz, J.M.

    1994-04-26

    Elongated coolant pumps suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator and out through the auxiliary equipment hatch. 14 figures.

  5. Apparatus and method for servicing an elongated suspended pump motor in an electric power plant with limited access

    DOEpatents

    Chavez, Rossemary V.; Ekeroth, Douglas E.; Johnson, F. Thomas; Matusz, John M.

    1994-01-01

    Elongated coolant pumps suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator and out through the auxiliary equipment hatch.

  6. Solar powered absorption cycle heat pump using phase change materials for energy storage

    NASA Technical Reports Server (NTRS)

    Middleton, R. L.

    1972-01-01

    Solar powered heating and cooling system with possible application to residential homes is described. Operating principles of system are defined and illustration of typical energy storage and exchange system is provided.

  7. Performance of chemical vapor deposition fabricated graphene absorber mirror in Yb3+ : Sc2SiO5 mode-locked laser

    NASA Astrophysics Data System (ADS)

    Cai, Wei; Li, Yaqi; Zhu, Hongtong; Jiang, Shouzhen; Xu, Shicai; Liu, Jie; Zheng, Lihe; Su, Liangbi; Xu, Jun

    2014-12-01

    A reflective graphene saturable absorber mirror (SAM) was successfully fabricated by chemical vapor deposition technology. A stable diode-pumped passively mode-locked Yb3+:Sc2SiO5 laser using a graphene SAM as a saturable absorber was accomplished for the first time. The measured average output power amounts to 351 mW under the absorbed pump power of 12.5 W. Without prisms compensating for dispersion, the minimum pulse duration of 7 ps with a repetition rate of 97 MHz has been obtained at the central wavelength of 1063 nm. The corresponding peak power and the maximum pulse energy were 516 W and 3.6 nJ, respectively.

  8. Double-beam, mode-controlling diode side-pumped Nd:YLF laser with near 60% efficiency

    NASA Astrophysics Data System (ADS)

    Deana, Alessandro M.; Wetter, Niklaus U.

    2015-02-01

    The double-beam, mode-controlling technique (DBMC) is a compact side-pumped laser design, very advantageous for systems based on active media with intermediate absorption cross section, such as Nd:YLiF4 (Nd:YLF). Recently, a record optical efficiency of 53.6% and 63.5% slope efficiency has been achieved for a Nd:YLF laser emitting at 1053 nm with diffraction limited beam quality. In this work we review our results using the DBMC design and present the latest achievements exploiting new ways to push the limit of this technique to higher pump powers. By narrowing down the laser emission bandwidth of the pump diode bar using a volume Bragg gratings (VBG) we increased the effective absorption cross section in the Nd:YLF crystal, improving the spatial overlap between pump and laser beam. With this setup the laser delivers 68 W peak fundamental mode output power at 115 W of QCW absorbed peak power, resulting near 60% of optical-to-optical efficiency which is, to the best of our knowledge, the highest efficiency ever reported for a Nd:YLF laser, considering even longitudinal pump schemes. The results reported here highlight the remarkable advantages of the side pumped DBMC laser scheme versus longitudinal pumped laser set-ups, showing that the efficiency of the side-pumped DBMC laser is not suppressed by its spatially weaker overlap between pump and laser mode and preserving single mode laser operation, even at high pump powers.

  9. Power scaling of a wavelength-narrowed diode laser system for pumping alkali vapors

    NASA Astrophysics Data System (ADS)

    Hersman, F. W.; Distelbrink, J. H.; Ketel, J.; Wilson, J.; Watt, D. W.

    2016-03-01

    We report a method for locking the output wavelength and reducing the spectral linewidth of diode lasers by feeding back light to the emitters from a wavelength selective external optical cavity. Ten years ago our team developed a stepped-mirror that allowed a single external cavity to lock the wavelength of a stack of diode array bars by equalizing path lengths between each emitter and the grating. Here we report combining one such step-mirror external cavity with an array of power dividers, each sending a portion of this feedback power to a separate diode array bar stack.

  10. The Use of Large Transparent Ceramics in a High Powered, Diode Pumped Solid State Laser

    SciTech Connect

    Yamamoto, R; Bhachu, B; Cutter, K; Fochs, S; Letts, S; Parks, C; Rotter, M; Soules, T

    2007-09-24

    The advent of large transparent ceramics is one of the key enabling technological advances that have shown that the development of very high average power compact solid state lasers is achievable. Large ceramic neodymium doped yttrium aluminum garnet (Nd:YAG) amplifier slabs are used in Lawrence Livermore National Laboratory's (LLNL) Solid State Heat Capacity Laser (SSHCL), which has achieved world record average output powers in excess of 67 kilowatts. We will describe the attributes of using large transparent ceramics, our present system architecture and corresponding performance; as well as describe our near term future plans.

  11. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  12. All solid-state continuous-wave Nd:YAG laser at 1319 and 659.5 nm under direct 885 nm pumping

    NASA Astrophysics Data System (ADS)

    Lü, Y. F.; Zhang, X. H.; Xia, J.; Yin, X. D.; Bao, L.; Quan, H.

    2010-01-01

    The continuous-wave high efficiency laser emission of Nd:YAG at the fundamental wavelength of 1319 nm and its 659.5-nm second harmonic obtained by intracavity frequency doubling with an LBO nonlinear crystal is investigated under pumping by diode laser at 885 nm (on the 4 F 3/2 → 4 I 13/2 transition). An end-pumped Nd:YAG crystal yielded 9.1 W at 1319 nm of continuous-wave output power for 18.2 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power is 0.55. Furthermore, 5.2 W 659.5 nm red light is acquired by frequency doubling, resulting in an optical-to-optical efficiency with respect to the absorbed pump power of 0.286. Comparative results obtained for the pump with diode laser at 808 nm (on the 4 F 5/2 → 4 I 13/2 transition) are given in order to prove the advantages of the 885 nm wavelength pumping.

  13. Nd:GdVO4 self-Raman laser using double-end polarised pumping at 880 nm for high power infrared and visible output

    NASA Astrophysics Data System (ADS)

    Lin, J.; Pask, H. M.

    2012-07-01

    We report and evaluate a novel double-end polarised 880 nm pumping scheme for a Nd:GdVO4 self-Raman laser, aimed at efficiently generating high output powers in the near-infrared and visible. Compared to conventional single-end pumping, this pump scheme has significant benefits in terms of absorption efficiency, temperature effects in the crystal, and mode-matching between the pumping beam and TEM00 resonator mode. The maximum first-Stokes output powers were 4.1 W for CW operation and 5.63 W for quasi-CW (50 % duty-cycle) operation, with the diode-Stokes conversion efficiency of 11.2 % and 10.3 %, respectively. Visible emission was also realised by intra-cavity frequency-doubling (586.5 nm) or sum-frequency-generation (559 nm) using BBO or LBO crystals. For CW operation, the maximum output power was 3.46 W at 586.5 nm and 4.05 W at 559 nm, with diode-visible conversion efficiency of 10.7 % and 12.5 %; while for quasi-CW operation (50 % duty-cycle), the maximum output peak power was 6.5 W at 586.5 nm and 9.2 W at 559 nm, corresponding to 13.1 % and 18.9 % diode-visible conversion efficiency.

  14. Effective Selection of the TEM00-Mode in a Powerful Nd:YVO4-Laser With the 808 nm Diode Pumping

    NASA Astrophysics Data System (ADS)

    Donin, V. I.; Yakovin, D. V.; Yakovin, М. D.

    2014-03-01

    The problems of an effective selection of the TEM00-mode and thermo-optical distortions in a Nd:YVO4 laser with the longitudinal diode pumping are considered. In an experiment with a 40-watt single-end pumping of the composite YVO4/Nd:YVO4 crystal, the single-mode output power of 24 W at an optical efficiency of ηopt = 57.1% (the slope efficiency of 63.3%) is obtained. Apparently, this is the greatest power for lasers based on the Nd-doped yttrium orthovanadate with the longitudinal pumping at λ = 808 nm from one end of the active crystal. Evaluations of the thermal effects show that when using the Nd:YVO4-crystal (the length 20 mm, the diameter 3 mm, and the doping of 0.27 atomic %) having two undoped ends and the double-end diode pumping with total power of 170 W, one can expect obtaining a 100-watt level of the output power in the TEM00-mode from a single active element.

  15. Demonstration of the ITER Power Exhaust Solution Using the Puff and Pump Technique on DIII-D

    SciTech Connect

    Wade, M.R.; West, W.P.; Hill, D.N.; Allen, S.L.; Boedo, J.A.; Brooks, N.H.; Fenstermacher, M.E.; Hogan, J.T.; Isler, R.C.; Jayakumar, R.J.; Lasnier, C.J.; Lehmer, R.; Leonard, A.W.; Maingi, R.; Moyer, R.A.; Petrie, T.W.; Schaffer, M.J.; Watkins, J.G.; Whyte, D.G.; Wood, R.D.

    1999-07-01

    In future, high power density fusion devices, the need to prevent excessive local deposition of the plasma energy efflux on the first-wall surfaces is a critical design consideration in order to maintain the integrity of such surfaces. This requirement must be met without significant impact on plasma purity or overall plasma confinement. For the International Thermonuclear Experimental Reactor (ITER), these constraints have led to the following design criteria [1] P{sub rad}/(P{sub input} + P{sub {alpha}}) = 83%, P{sub rad,core}/(P{sub input} + P{sub {alpha}}) = 33%, P{sub target}/P{sub loss} = 17%, Z{sub eff} < 1.8, and {tau}{sub E}/{tau}{sub E,ITER93H} > 0.85. Here, P{sub loss} is the power flowing out of the core (i.e., P{sub input} + P{sub {alpha}} - P{sub rad,core})and P{sub target} is the power conducted to the target plate. These criteria represent a compromise between obtaining sufficient radiation to reduce the target heat load to a tolerable level, minimizing core fuel dilution, and maintaining sufficient power flow through the edge plasma to maintain H-mode confinement. Past experiments have had difficulty achieving these conditions simultaneously when using seeded impurities, and therefore there has been some concern regarding the viability of the ITER design. However, recent experiments in DIII-D using the puff and pump technique with argon as the seeded impurity have demonstrated the compatibility of these design constraints. In particular, steady-state plasma conditions have been achieved with P{sub rad}/P{sub input} = 72%, P{sub rad,core}/P{sub input} = 16%, P{sub target}/P{sub loss} = 17%, Z{sub eff} = 1.85, and {tau}{sub E}/{tau}{sub E,ITER93H} = 1.05.

  16. Broadband high-power mid-IR femtosecond pulse generation from an ytterbium-doped fiber laser pumped optical parametric amplifier.

    PubMed

    Hu, Chengzhi; Chen, Tao; Jiang, PeiPei; Wu, Bo; Su, Jianjia; Shen, Yonghang

    2015-12-15

    We report on a high-power periodically poled MgO-doped lithium niobate (MgO:PPLN)-based femtosecond optical parametric amplifier (OPA), featuring a spectral seamless broadband mid-infrared (MIR) output. By modifying the initial chirp and spectrum of the mode-locked seed laser, the Yb fiber pump laser exhibits a final output power of 14 W with sub-200-fs pulse duration after power amplification and compression. When the OPA was seeded with a broadband amplified spontaneous emission (ASE) source, a damage-limited 0.6 W broadband MIR radiation was experimentally obtained under the pump power of 10.15 W at 82 MHz repetition rate, corresponding to an overall OPA conversion efficiency of 32.7%. The 3 dB bandwidth of the mid-IR idler was 291.9 nm, centering at 3.34 μm. PMID:26670509

  17. High-Beam-Quality All-Solid-State 355 nm Ultraviolet Pulsed Laser Based on a Master-Oscillator Power-Amplifier System Pumped at 888 nm

    NASA Astrophysics Data System (ADS)

    Hong, Hailong; Liu, Qiang; Huang, Lei; Gong, Mali

    2012-09-01

    An efficient all-solid-state 355 nm ultraviolet laser based on an 888 nm pumped master-oscillator power-amplifier (MOPA) system is presented. Due to the high beam quality of the fundamental wave being superior to 1.15 (M2) under all pump powers and pulse repetition frequencies (PRFs), the UV laser has the advantage of being able to operate continuously from zero to maximum power. The maximum green and UV output powers were 45.9 W at 50 kHz and 24.3 W at 65 kHz with the corresponding conversion efficiencies from IR-to-green and IR-to-UV of 66.0% and 34.1%, respectively.

  18. Methods to determine pumped irrigation-water withdrawals from the Snake River between Upper Salmon Falls and Swan Falls Dams, Idaho, using electrical power data, 1990-95

    USGS Publications Warehouse

    Maupin, Molly A.

    1999-01-01

    Pumped withdrawals compose most of the irrigation-water diversions from the Snake River between Upper Salmon Falls and Swan Falls Dams in southwestern Idaho. Pumps at 32 sites along the reach lift water as high as 745 feet to irrigate croplands on plateaus north and south of the river. The number of pump sites at which withdrawals are being continuously measured has been steadily decreasing, from 32 in 1990 to 7 in 1998. A cost-effective and accurate means of estimating annual irrigation-water withdrawals at pump sites that are no longer continuously measured was needed. Therefore, the U.S. Geological Survey began a study in 1998, as part of its Water-Use Program, to determine power-consumption coeffi- cients (PCCs) for each pump site so that withdrawals could be estimated by using electrical powerconsumption and total head data. PCC values for each pump site were determined by using withdrawal data that were measured by the U.S. Geological Survey during 1990–92 and 1994–95, energy data reported by Idaho Power Company during the same period, and total head data collected at each site during a field inventory in 1998. Individual average annual withdrawals for the 32 pump sites ranged from 1,120 to 44,480 acre-feet; average PCC values ranged from 103 to 1,248 kilowatthours per acre-foot. During the 1998 field season, power demand, total head, and withdrawal at 18 sites were measured to determine 1998 PCC values. Most of the 1998 PCC values were within 10 percent of the 5-year average, which demonstrates that withdrawals for a site that is no longer continuously measured can be calculated with reasonable accuracy by using the PCC value determined from this study and annual power-consumption data. K-factors, coefficients that describe the amount of energy necessary to lift water, were determined for each pump site by using values of PCC and total head and ranged from 1.11 to 1.89 kilowatthours per acre-foot per foot. Statistical methods were used to define the

  19. Experimental and theoretical study of passively Q-switched Yb:YAG laser with GaAs saturable absorber near 1050 nm

    NASA Astrophysics Data System (ADS)

    Chu, Hongwei; Zhao, Shengzhi; Yang, Kejian; Li, Yuefei; Li, Dechun; Li, Guiqiu; Zhao, Jia; Qiao, Wenchao; Xu, Xiaodong; Di, Juqing; Zheng, Lihe; Xu, Jun

    2014-03-01

    A diode-end-pumped passively Q-switched ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser with gallium arsenide (GaAs) wafer as saturable absorber has been realized. In the experiment, two pieces of GaAs wafers with respective thicknesses of 400 and 700 μm were used respectively. The output laser characteristics such as the pulse duration, single pulse energy and peak power, have been measured. By using thicker GaAs wafer as saturable absorber, a minimum pulse duration of 3.5 ns was obtained with an average output power of 361 mW and a pulse repetition rate (PRR) of 25 kHz, corresponding to a single pulse energy of 19.6 μJ and a peak power of 5.7 kW. With a 400 μm-thick GaAs wafer as saturable absorber, a maximum output power of 469 mW was achieved. The central wavelength of the laser was measured to be 1050.4 nm at pump power of 7.8 W and dual wavelength operation peaked at 1049.3 nm and 1051.6 nm was observed at a high pump power of 10 W. By considering Gaussian spatial distribution and the thermal effects in the gain medium, the coupled rate equations for passively Q-switched Yb:YAG laser with GaAs saturable absorber were given.

  20. Design of a thin disk amplifier with extraction during pumping for high peak and average power Ti:Sa systems (EDP-TD).

    PubMed

    Chvykov, Vladimir; Nagymihaly, Roland S; Cao, Huabao; Kalashnikov, Mikhail; Osvay, Karoly

    2016-02-22

    Combination of the scheme of extraction during pumping (EDP) and the Thin Disk (TD) technology is presented to overcome the limitations associated with thermal cooling of crystal and transverse amplified spontaneous emission in high average power laser systems based on Ti:Sa amplifiers. The optimized design of high repetition rate 1-10 PW Ti:Sapphire EDP-TD power amplifiers are discussed, including their thermal dynamic behavior. PMID:26907029

  1. High-power 660.5 nm red laser from diode-side-pumped intracavity frequency-doubled Nd:YLF laser

    NASA Astrophysics Data System (ADS)

    Wang, Zhichao; Wang, Baoshan; Chen, Ming; Yang, Feng; Zhang, Shenjin; Zhang, Xiaowen; Bo, Yong; Xu, Yiting; Zong, Nan; Xu, Jialin; Peng, Qinjun; Cui, Dafu; Xu, Zuyan

    2015-12-01

    We demonstrate a high-power red laser at 660.5 nm from intracavity frequency doubling of a diode-side-pumped 1321 nm Nd:LiYF4 (Nd:YLF) ring laser in a LiB3O5 (LBO) crystal. The maximum average output power of the red laser is obtained to be 23 W with beam quality factor M 2  =  1.3.

  2. High-power PPMgLN-based optical parametric oscillator pumped by a linearly polarized, semi-fiber-coupled acousto-optic Q-switched fiber master oscillator power amplifier.

    PubMed

    Chen, Tao; Jiang, Peipei; Yang, Dingzhong; Hu, Chengzhi; Wu, Bo; Shen, Yonghang

    2013-09-01

    We have experimentally demonstrated a periodically poled magnesium-oxide-doped lithium niobate (PPMgLN)-based, fiber-laser-pumped optical parametric oscillator (OPO) generating idler wavelength of 3.82 μm. The pump fiber laser was constructed with a linearly polarized, semi-fiber-coupled acousto-optic Q-switched fiber oscillator and a polarization-maintaining fiber amplifier with pulse duration of 190 ns at the highest output power. The OPO was specifically configured in single-pass, singly resonant linear cavity structure to avoid the damage risk of the pump fiber laser, which is always a serious issue in the fiber-laser-pumped, double-pass, singly oscillating structured OPOs. Under the highest pump power of 25 W, an idler average output power of 3.27 W with one-hour peak-to-peak instability of 5.2% was obtained. The measured M2 factors were 1.98 and 1.44 for horizontal and vertical axis, respectively. The high power stability and good beam quality demonstrated the suitability of such technology for practical application. PMID:24085093

  3. Experimental investigation of a diode-pumped powerful continuous-wave dual-wavelength Nd:YAG laser at 946 and 938.6 nm

    NASA Astrophysics Data System (ADS)

    Chen, F.; Yu, X.; Yan, R. P.; Li, X. D.; Li, D. J.; Yang, G. L.; Xie, J. J.; Guo, J.

    2013-05-01

    In this paper, a diode-pumped high-power continuous-wave (cw) dual-wavelength Nd:YAG laser at 946 and 938.6 nm is reported. By using an end-pumped structure, comparative experiments indicate that a 5 mm-length Nd:YAG crystal with a Nd3+-doping concentration of 0.3 at.% is favorable for high-power laser operation, and the optimal transmissivity of the output coupler is 9%. As a result, a maximum output power of 17.2 W for a dual-wavelength laser at 946 and 938.6 nm is obtained at an incident pump power of 75.9 W, corresponding to a slope efficiency of 26.5%. To the best of our knowledge, this is the highest output power of a quasi-three-level dual-wavelength laser using a conventional Nd:YAG crystal achieved to date. By using a traveling knife-edge method, the beam quality factor and far-field divergence angle at 17 W power level are estimated to be 4.0 and 6.13 mrad, respectively.

  4. Longitudinal temperature distribution in an end-pumped solid-state amplifier medium: application to a high average power diode pumped Yb:YAG thin disk amplifier.

    PubMed

    Bourdet, Gilbert L; Yu, Haiwu

    2007-08-10

    We propose a simple analytical derivation making it possible to compute a one-dimensional temperature variation in an end-pumped solid-state laser. This derivation takes into account the pump intensity variation along the crystal, the doping concentration, and temperature dependence of the thermal conductivity. We then compare this simulation with the one usually used, which does not take into account any of these dependences. The results show that, at room temperature, the two methods are in good agreement, but at a cryogenic temperature where the thermal conductivity varies fast with temperature, a large discrepancy is found, and the conventional computations underestimate both the average temperature and the longitudinal gradient. PMID:17694159

  5. 12. Sewage Ejector Pumps, view to the southwest. These pumps ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Sewage Ejector Pumps, view to the southwest. These pumps are connected to sewage treatment tanks. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  6. Overview of the Lucia laser program: toward 100-Joules, nanosecond-pulse, kW averaged power based on ytterbium diode-pumped solid state laser

    NASA Astrophysics Data System (ADS)

    Chanteloup, J.-C.; Yu, H.; Bourdet, G.; Dambrine, C.; Ferre, S.; Fulop, A.; Le Moal, S.; Pichot, A.; Le Touze, G.; Zhao, Z.

    2005-04-01

    We present the current status of the Lucia laser being built at the LULI laboratory, the national civil facility for intense laser matter interaction in France. This diode pumped laser will deliver a 100 Joules, 10 ns, 10 Hz pulse train from Yb:YAG using 4400 power diode laser bars. We first focus on the amplifier stage by describing the reasons for selecting our extraction architecture. Thermal issues and solutions for both laser and pumping heads are then described. Finally, we emphasize more specifically the need for long-lifetime high-laser-damage-threshold coatings and optics.

  7. High-efficiency 17 W, 80 MHz repetition rate, passively mode-locked TEM00 Nd:YAG oscillator pumped at 885 nm

    NASA Astrophysics Data System (ADS)

    Zhang, X.-F.; Li, F.-Q.; Zong, N.; Le, X.-Y.; Cui, D.-F.; Xu, Z.-Y.

    2011-03-01

    We report on a passively mode-locked TEM00 Nd:YAG oscillator with the beam quality at M 2 = 1.1 by a semiconductor saturable absorber mirror under 885 nm laser diode direct pumping for the first time. A maximum average output power of 17 W at a repetition rate of 80 MHz with 39 ps pulse width was obtained under the absorbed pump power of 38 W, corresponding to an optical-optical efficiency of 44% and the slope efficiency of 69%, respectively.

  8. Spatially confined low-power optically pumped ultrafast synchrotron x-ray nanodiffraction

    SciTech Connect

    Park, Joonkyu; Zhang, Qingteng; Chen, Pice; Cosgriff, Margaret P.; Tilka, Jack A.; Evans, Paul G.; Adamo, Carolina; Schlom, Darrell G.; Wen, Haidan; Zhu, Yi

    2015-08-15

    The combination of ultrafast optical excitation and time-resolved synchrotron x-ray nanodiffraction provides unique insight into the photoinduced dynamics of materials, with the spatial resolution required to probe individual nanostructures or small volumes within heterogeneous materials. Optically excited x-ray nanobeam experiments are challenging because the high total optical power required for experimentally relevant optical fluences leads to mechanical instability due to heating. For a given fluence, tightly focusing the optical excitation reduces the average optical power by more than three orders of magnitude and thus ensures sufficient thermal stability for x-ray nanobeam studies. Delivering optical pulses via a scannable fiber-coupled optical objective provides a well-defined excitation geometry during rotation and translation of the sample and allows the selective excitation of isolated areas within the sample. Experimental studies of the photoinduced lattice dynamics of a 35 nm BiFeO{sub 3} thin film on a SrTiO{sub 3} substrate demonstrate the potential to excite and probe nanoscale volumes.

  9. Spatially confined low-power optically pumped ultrafast synchrotron x-ray nanodiffraction.

    PubMed

    Park, Joonkyu; Zhang, Qingteng; Chen, Pice; Cosgriff, Margaret P; Tilka, Jack A; Adamo, Carolina; Schlom, Darrell G; Wen, Haidan; Zhu, Yi; Evans, Paul G

    2015-08-01

    The combination of ultrafast optical excitation and time-resolved synchrotron x-ray nanodiffraction provides unique insight into the photoinduced dynamics of materials, with the spatial resolution required to probe individual nanostructures or small volumes within heterogeneous materials. Optically excited x-ray nanobeam experiments are challenging because the high total optical power required for experimentally relevant optical fluences leads to mechanical instability due to heating. For a given fluence, tightly focusing the optical excitation reduces the average optical power by more than three orders of magnitude and thus ensures sufficient thermal stability for x-ray nanobeam studies. Delivering optical pulses via a scannable fiber-coupled optical objective provides a well-defined excitation geometry during rotation and translation of the sample and allows the selective excitation of isolated areas within the sample. Experimental studies of the photoinduced lattice dynamics of a 35 nm BiFeO3 thin film on a SrTiO3 substrate demonstrate the potential to excite and probe nanoscale volumes. PMID:26329208

  10. In-band pumped Ho3+:KY3F10 2 μm laser.

    PubMed

    Schellhorn, Martin; Parisi, Daniela; Veronesi, Stefano; Bolognesi, Giacomo; Eichhorn, Marc; Tonelli, Mauro

    2013-02-15

    We report the first observation to our knowledge of room-temperature continuous-wave laser operation on the (5)I(7)→(5)I(8) transition of Ho(3+) ions in a KY(3)F(10) single crystal. Using a Tm-doped silica fiber laser operating at 1938 nm as a pump source, a maximum laser power of 1.8 W was obtained at a wavelength of ~2040 nm for 27 W of absorbed pump power with a slope efficiency of 19.1% with respect to absorbed power. At low cavity output coupling, the lasing wavelength shifted to 2060.5 nm. The beam propagation factor (M(2)) was measured to be <1.06 at the maximum output power, confirming fundamental transverse-mode (TEM(00)) operation. Performing a Caird analysis, we determined resonator round-trip losses and intrinsic slope efficiency of 30% and 43.8%, respectively. PMID:23455117

  11. Solid state saturable absorbers for Q-switching at 1 and 1.3μm: investigation and modeling

    NASA Astrophysics Data System (ADS)

    Šulc, Jan; Arátor, Pavel; Jelínková, Helena; Nejezchleb, Karel; Škoda, Václav; Kokta, Milan R.

    2008-02-01

    Yttrium and Lutecium garnets (YAG and LuAG) doped by Chromium or Vanadium ions (Cr 4+ or V 3+) were investigated as saturable absorbers potentially useful for passive Q-switching at wavelengths 1 μm and/or 1.3 μm. For comparison also color center saturable absorber LiF:F - II and Cobalt doped spinel (Co:MALO) were studied. Firstly, low power absorption spectra were recorded for all samples. Next, absorbers transmission in dependence on incident energy/power density was measured using the z-scan method. Crystals Cr:YAG, Cr:LuAG, V:YAG, and LiF:F - II were tested at wavelength 1064 nm. Therefore Alexandrite laser pumped Q-switched Nd:YAG laser was used as a radiation source (pulse length 6.9 ns, energy up to 1.5 mJ). Crystals V:YAG, V:LuAG, and Co:MALO were tested at wavelength 1338 nm. So diode pumped Nd:YAG/V:YAG microchip laser was used as a radiation source (pulse length 6.2 ns, energy up to 0.1 mJ). Using measured data fitting, and by their comparison with numerical model of a "thick" saturable absorber transmission for Q-switched Gaussian laser beam, following parameters were estimated: saturable absorber initial transmission T 0, saturation energy density w s, ground state absorption cross-section σ GSA, saturated absorber transmission T s, excited state absorption cross-section σ ESA, ratio γ = σ GSA/σ ESA, and absorbing ions density. For V:YAG crystal, a polarization dependence of T s was also investigated. With the help of rate equation numerical solution, an impact of saturable absorber parameters on generated Q-switched pulse properties was studied in plane wave approximation. Selected saturable absorbers were also investigated as a Q-switch and results were compared with the model.

  12. Doppler-free spectroscopy of mercury at 253.7 nm using a high-power, frequency-quadrupled, optically pumped external-cavity semiconductor laser.

    PubMed

    Paul, Justin; Kaneda, Yushi; Wang, Tsuei-Lian; Lytle, Christian; Moloney, Jerome V; Jones, R Jason

    2011-01-01

    We have developed a stable, high-power, single-frequency optically pumped external-cavity semiconductor laser system and generate up to 125 mW of power at 253.7 nm using successive frequency doubling stages. We demonstrate precision scanning and control of the laser frequency in the UV to be used for cooling and trapping of mercury atoms. With active frequency stabilization, a linewidth of <60 kHz is measured in the IR. Doppler-free spectroscopy and stabilization to the 6(1)S(0)-6(3)P(1) mercury transition at 253.7 nm is demonstrated. To our knowledge, this is the first demonstration of Doppler-free spectroscopy in the deep UV based on a frequency-quadrupled, high-power (>1 W) optically pumped semiconductor laser system. The results demonstrate the utility of these devices for precision spectroscopy at deep-UV wavelengths. PMID:21209687

  13. Gastrostomy feeding tube - pump - child

    MedlinePlus

    ... supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding ... drip chamber, roller clamp, and long tube) Extension set, for a Bard Button or MIC-KEY (this ...

  14. All-fiber quasi-continuous wave supercontinuum generation in single-mode high-nonlinear fiber pumped by submicrosecond pulse with low peak power.

    PubMed

    Gao, Weiqing; Liao, Meisong; Yan, Xin; Suzuki, Takenobu; Ohishi, Yasutake

    2012-05-01

    We demonstrate quasi-continuous wave supercontinuum generation in a single-mode high-nonlinear fiber (HNLF) in 1.55 μm band, which is pumped by the amplified passively Q-switched submicrosecond pulse. The pump wavelength is in the normal dispersion region of HNLF and near to the zero-dispersion wavelength. The broad SC spectral range from 1200 to 2260 nm is obtained with the low pump peak power of 17.8 W. The 20 dB bandwidth of 922 nm from 1285 to 2207 nm is obtained with the assumption that the peak near 1560 nm is filtered. The spectrum density for the 20 dB bandwidth is from -27.5 to -7.5 dbm/nm. PMID:22614410

  15. 7.6  W 1342  nm passively mode-locked picosecond composite Nd:YVO4/YVO4 laser with a semiconductor saturable absorber mirror.

    PubMed

    Tu, Wei; Chen, Ying; Zong, Nan; Liu, Ke; Wang, Zhi-Min; Zhang, Feng-Feng; Zhang, Shen-Jin; Yang, Feng; Yuan, Lei; Bo, Yong; Peng, Qin-Jun; Cui, Da-Fu; Xu, Zu-Yan

    2015-04-10

    A high average power 1342 nm passively CW mode-locked picoseconds (ps) composite Nd:YVO4 laser was demonstrated with a semiconductor saturable absorber mirror (SESAM). The oscillator cavity was carefully designed to optimize the laser beam radii in the crystal and on the SESAM. The combination of composite bonded laser crystal, direct pumping, and dual end-pumped configuration was adopted to reduce the thermal effect and produce high output power with high beam quality. A maximum average output power of 7.63 W was obtained with a repetition rate of 77 MHz and a pulse duration of 24.2 ps under an absorbed pump power of 38.6 W, corresponding to an optical-optical efficiency of 19.7% and a slope efficiency of 25.9%, respectively. The beam quality factor M(2) was measured to be 1.49. PMID:25967328

  16. Watt-level passively Q-switched heavily Er3+-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror

    PubMed Central

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-01-01

    A diode-cladding pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail. PMID:27225029

  17. Watt-level passively Q-switched heavily Er3+-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-05-01

    A diode-cladding pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail.

  18. Watt-level passively Q-switched heavily Er(3+)-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror.

    PubMed

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-01-01

    A diode-cladding pumped mid-infrared passively Q-switched Er(3+)-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail. PMID:27225029

  19. S-band Q-switched fiber laser using molybdenum disulfide (MoS2) saturable absorber

    NASA Astrophysics Data System (ADS)

    Ahmad, Harith; Afiq Ismail, Mohd; Suthaskumar, Muneswaran; Cheak Tiu, Zian; Wadi Harun, Sulaiman; Zamani Zulkifli, Mohd; Samikannu, Sathiyan; Sivaraj, Sivabalan

    2016-03-01

    In this letter, a molybdenum disulfide (MoS2) saturable absorber (SA) is fabricated using a simple drop cast method to generate Q-switched fiber laser operating in the S-band region (1460 nm-1530 nm). The MoS2 solution was prepared using the liquid phase exfoliation (LPE) method where MoS2 crystals were added into dimethylformamide (DMF) solvent and subsequently sonicated and centrifuged. They were then repeatedly dripped onto fiber ferrules and dried in an oven. The resultant Q-switched fiber laser starts with some physical disturbance when the pump power was set at 40 mW and continues to operate until the pump power reaches 120 mW. The resultant repetition rate varies with pump power between 27.17 to 101.17 kHz while the changes in pulse widths are from 3.0 to 1.4 μs.

  20. Rotational Raman spectroscopy of high-density spin-exchange optical pumping cells

    NASA Astrophysics Data System (ADS)

    Walter, Daniel K.; Griffith, Warren M.; Happer, William

    2000-06-01

    We report on measurements of the spatial temperature distribution in multiple-atmosphere spin-exchange optical pumping cells pumped with high-power diode laser arrays, obtained by observing the Raman scattering of an argon-ion probe beam by the 60-200 torr of molecular nitrogen buffer gas contained in the cell. We find that over a large range of ambient oven temperatures, the temperature of the gas in the 45-cc pump chamber is elevated by roughly 10 Kelvin per Watt of D1 pump radiation absorbed by the alkali vapor. In addition, we have observed flat temperature profiles across the cells, indicating that the transfer of heat deposited by the pump laser is dominated by convection, rather than conduction.

  1. High-peak-power, short-pulse-width, LD end-pumped, passively Q-switched Nd:YAG 946 nm laser

    NASA Astrophysics Data System (ADS)

    Yan, Renpeng; Yu, Xin; Ma, Yufei; Li, Xudong; Chen, Deying; Yu, Junhua

    2012-10-01

    High-peak-power, short-pulse-width diode pumped 946 nm Nd:YAG laser in passively Q-switching operation with Cr4+:YAG is reported. The highest average output power reaches 3.4 W using the Cr4+:YAG with initial transmissivity T0=95%. When the T0=90% Cr4+:YAG is employed, the maximum peak power of 31.4 kW with a pulse width of 8.3 ns at 946 nm is generated.

  2. Laser diode-pumped dual-cavity high-power fiber laser emitting at 1150  nm employing hybrid gain.

    PubMed

    Chen, Yizhu; Xiao, Hu; Xu, Jiangming; Leng, Jinyong; Zhou, Pu

    2016-05-10

    We demonstrate a laser diode-pumped dual-cavity high-power fiber laser emitting at 1150 nm. The laser employs Yb and Raman gains simultaneously. The fiber laser with a simple structure achieves high-efficiency operation while efficiently suppressing the amplified spontaneous emission and parasitic oscillation. The maximum output power at 1150 nm is 110.8 W, with an optical-to-optical efficiency of 57%. Further power scaling at 1150 nm is expected with the optimization of the system design. PMID:27168299

  3. Saturable absorber mode-locked femtosecond Cr4+:YAG laser

    NASA Astrophysics Data System (ADS)

    Hayduk, Michael J.; Johns, Steven T.; Krol, Mark F.

    1997-07-01

    We have demonstrated self-starting passive mode-locking of a chromium-doped:YAG (Cr4+:YAG) laser using a saturable absorber mirror (SAM) structure. Highly stable femtosecond pulses tunable from 1488 to 1535 nm were generated. Average TEM00 output powers ranged from 40 to 80 mW with a minimum pulse width of 120 fs measured at 1488 nm. The generation of ultrashort pulses in solid-state lasers using the Kerr lens modelocking (KLM) technique has been the center of much attention in recent years. Sub 100 fs pulses have been produced using many different laser systems. However, the KLM process is very sensitive to cavity alignment and is easily perturbed by mechanical vibrations and pump power fluctuations. A more reliable process makes use of a saturable absorber to start and stabilize the soliton formation process. The saturable absorber eliminates the need for critical cavity alignment. The femtosecond pulse train produced by the SAM structure in the Cr4+:YAG laser system is highly stable over very long periods of time. The wide tunability of the Cr4+:YAG laser throughout the 1.5 micrometer transmission window of optical fiber makes it an ideal spectroscopic source for the characterization and development of novel materials and devices for ultrafast optical interconnects.

  4. Power scaling of diode-pumped Nd(3+) and Yb(3+)-Doped YCa(4)O(BO(3))(3) (YCOB): A new self-frequency doubling laser

    NASA Astrophysics Data System (ADS)

    Hammons, Dennis Allen

    Intracavity-doubled, diode-pumped solid-state lasers are rapidly gaining acceptance in manufacturing, medical and scientific applications. The reasons for this intense development include their high efficiency, diffraction-limited beam quality, and long lifetimes. Moreover, a compact, low cost, rugged package design makes these systems attractive. The different approaches to intracavity frequency doubling of infrared laser radiation using birefringent phase-matching have generally included a nonlinear crystal that is separated from the laser medium to generate efficient continuous-wave visible light. A special case of intracavity-doubling known as self-frequency doubling in conjunction with diode-pumping offers the potential for a simpler, more compact and low cost design by integrating the laser and harmonic conversion process in one crystal. A comprehensive study of the operation and power scaling abilities of the newly developed crystal YCa4O(BO3)3 (YCOB)---doped with either Nd3+ or Yb3+ for self-frequency doubling is performed. Laser operation and self-frequency doubling is achieved under flashlamp, Ti:Sapphire, and diode-pumping. High power diode-pumped operation of Nd3+:YCOB using a novel angularly-multiplexed diode-laser system for power scaling demonstrates more than 1.9 W at 1060 nm and over 245 mW at 530 nm. In addition, analysis of thermal-fracturing of Nd 3+:YCOB suggests a thermal fracture figure-of-merit of ˜247 W/m for Nd3+:YCOB. Diode-pumped operation at 977 nm of Yb 3+:YCOB has demonstrated slope efficiencies of better than 40% with operation from 1030 to 1090 nm.

  5. Gain chip design, power scaling and intra-cavity frequency doubling with LBO of optically pumped red-emitting AlGaInP-VECSELs

    NASA Astrophysics Data System (ADS)

    Kahle, Hermann; Mateo, Cherry M. N.; Brauch, Uwe; Bek, Roman; Schwarzbäck, Thomas; Jetter, Michael; Graf, Thomas; Michler, Peter

    2016-03-01

    The wide range of applications in biophotonics, television or projectors, spectroscopy and lithography made the optically-pumped semiconductor (OPS) vertical external cavity surface-emitting lasers (VECSELs) an important category of power scalable lasers. The possibility of bandgap engineering, inserting frequency selective and converting elements into the open laser cavity and laser emission in the fundamental Gaussian mode leads to ongoing growth of the area of applications for tuneable laser sources. We present an AlGaInP-VECSEL system with a multi quantum well structure consisting of compressively strained GaInP quantum wells in an AlxGa1-xInP separate confinement heterostructure with an emission wavelength around 665 nm. The VECSEL chip with its n-λ cavity is pumped by a 532nm Nd:YAG laser under an angle to the normal incidence of 50°. In comparison, a gain chip design for high absorption values at pump wavelengths around 640nm with the use of quantum dot layers as active material is also presented. Frequency doubling is now realized with an antireflection coated lithium borate crystal, while a birefringent filter, placed inside the laser cavity under Brewster's angle, is used for frequency tuning. Further, power-scaling methods like in-well pumping as well as embedding the active region of a VECSEL between two transparent ic heaspreaders are under investigation.

  6. Summary of Test Results From a 1 kW(sub e)-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  7. Summary of Test Results From a 1 kWe-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  8. A diode pumped passively mode-locked Nd:CaGdAlO4 laser

    NASA Astrophysics Data System (ADS)

    Rao, H.; Cong, Z. H.; Qin, Z. G.; Feng, C.; Wang, Q. P.; Liu, Z. J.; Zhang, X. Y.; Zhang, S. S.; Liu, Y.; Men, S. J.; Xia, J. B.; Di, J. Q.; Xu, X. D.; Xu, J.

    2016-04-01

    A diode pumped passively mode-locked Nd:CaGdAlO4 (Nd:CGA) laser was demonstrated. By using a semiconductor saturable-absorber mirror (SESAM) as the modulator, stable mode-locked pulses with a duration of 6.0 ps and a repetition rate of 88.3 MHz have been achieved at a central wavelength of 1078.6 nm. The maximum output power of 452 mW was obtained under a pump power of 10 W.

  9. Passively Q-switched 2 μm Tm:YAP laser based on graphene saturable absorber mirror.

    PubMed

    Hou, Jia; Zhang, Baitao; He, Jingliang; Wang, Zhaowei; Lou, Fei; Ning, Jian; Zhao, Ruwei; Su, Xiancui

    2014-08-01

    Using high-quality single-layer graphene as a saturable absorber, Tm:YAlO₃ (Tm:YAP) crystal as the gain medium, we demonstrated a laser-diode-pumped, compact, passively Q-switched (PQS) solid-state laser in the 2 μm region. The maximum average output power was 362 mW, with the corresponding largest pulse repetition rate and pulse energy of 42.4 kHz and 8.5 μJ, respectively. Under the same pump power, the pulse width of 735 ns was obtained, which is, to our best knowledge, the shortest pulse width among Tm-doped solid-state PQS lasers using graphene saturable absorber mirrors. PMID:25090328

  10. Generation and control of pressure pulsations emitted from centrifugal pumps: A review

    SciTech Connect

    Rzentkowski, G.

    1996-12-01

    Pressure pulsations emitted by centrifugal pumps may strongly interact with a piping system, leading to excessive vibration and alternating stresses beyond endurance limits. Several cases of this nature were reported, especially in chemical, petro-chemical and power generation industries, causing costly repairs and loss of power. In the past, research attention was primary focused on corrective actions involving the design and installation of piping elements to absorb acoustic energy emitted by pumps. Currently, more emphasis is placed on developing analytical tools to predict piping system acoustics and avoid undesirable resonance effects. Little attention has been directed towards preventive actions, leading to a better understanding of pumps as an acoustic source. This paper provides an overview of the underlying excitation mechanisms and modelling techniques, and explores the role of pump design parameters in controlling pressure pulsations. The application here is to primary heat transport system of CANDU reactor.

  11. Detection of pump degradation

    SciTech Connect

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  12. Tunable Mid-infrared ZnGeP2 RISTRA OPO pumped by periodically-poled Rb:KTP optical parametric master-oscillator power amplifier.

    PubMed

    Stoeppler, G; Thilmann, N; Pasiskevicius, V; Zukauskas, A; Canalias, C; Eichhorn, M

    2012-02-13

    A laser-diode pumped Q-switched single-frequency Nd:YAG MOPA operating at 100 Hz was used to generate tunable mid-infrared radiation between 6.27 µm and 8.12 µm by employing a cascaded parametric arrangement consisting of degenerate parametric master-oscillator power amplifier using a large aperture periodically-poled Rb:KTiOPO4 which in turn pumped a ZnGeP2 (ZGP) nonplanar RISTRA OPO. The noncollinear ZGP RISTRA tuning behavior is elucidated. The device is aimed for minimally invasive surgery applications at 6.45 µm where the peak power of 193 kW in 5 ns pulses is demonstrated. PMID:22418210

  13. Diode-pumped Nd:YVO4-Nd:YLF blue laser at 488 nm by intracavity sum-frequency-mixing

    NASA Astrophysics Data System (ADS)

    Lü, Y. F.; Xia, J.; Zhang, X. H.; Li, C. L.; Zhao, Z. M.; Liu, Z. T.

    2010-07-01

    We report a laser architecture to obtain continuous-wave blue radiation at 488 nm. A 808 nm diodepumped the Nd:YVO4 crystal emitting at 914 nm. A part of the pump power was then absorbed by the Nd:YVO4 crystal. The remaining was used to pump the Nd:YLF crystal emitting at 1047 nm. Intracavity sum-frequency mixing at 914 and 1047 nm was then realized in a LBO crystal to reach the blue radiation. We obtained a continuous-wave output power of 514 mW at 488 nm with a pump laser diode emitting 19.6 W at 808 nm.

  14. High power mid-infrared supercontinuum generation in a single-mode ZBLAN fiber pumped by amplified picosecond pulses at 2 μm

    NASA Astrophysics Data System (ADS)

    Liu, Kun; Liu, Jiang; Shi, Hongxing; Tan, Fangzhou; Jiang, Yijian; Wang, Pu

    2015-03-01

    We report high power all fiber mid-infrared (mid-IR) supercontinuum (SC) generation in a single-mode ZBLAN (ZrF4- BaF2-LaF3-AlF3-NaF) fiber with up to 21.8 W average output power from 1.9 to beyond 3.8 μm pumped by amplified picosecond pulses from a master oscillator power amplifier (MOPA) based on small-core single-mode thulium-doped fiber (TDF) with injected seed pulse width of 24 ps and repetition of 93.6 MHz at 1963 nm. The optical-optical conversion efficiency from the 793 nm pump laser of the last stage thulium-doped fiber amplifier (TDFA) to mid-IR SC output is 17%. It is, to the best of our knowledge, the highest average power mid-IR SC generation in a ZBLAN fiber to date. In addition, a noise-like fiber oscillator based on a nonlinear loop mirror (NOLM) with wavepacket width of ~1.4 ns and repetition rate of 3.36 MHz at 1966 nm is also used as a seed of the MOPA for mid-IR SC generation in the ZBLAN fiber. At last, a mid-IR SC from 1.9 to beyond 3.6 μm with average output power of 14.3W, which is limited by injected noise-like pulses power, is generated. The optical-optical conversion efficiency from the 793 nm pump laser of the last stage TDFA to mid-IR SC output is 14.9%. This proves the amplified noise-like pulses are also appropriate for high power mid-IR SC generation in the ZBLAN fiber.

  15. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1980-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

  16. TPX/TFTR Neutral Beam energy absorbers

    SciTech Connect

    Dahlgren, F.; Wright, K.; Kamperschroer, J.; Grisham, L.; Lontai, L.; Peters, C.; VonHalle, A.

    1993-11-01

    The present beam energy absorbing surfaces on the TFTR Neutral Beams such as Ion Dumps, Calorimeters, beam defining apertures, and scrapers, are simple water cooled copper plates which wee designed to absorb (via their thermal inertia) the incident beam power for two seconds with a five minute coal down interval between pulses. These components are not capable of absorbing the anticipated beam power loading for 1000 second TPX pulses and will have to be replaced with an actively cooled design. While several actively cooled energy absorbing designs were considered,, the hypervapotron elements currently being used on the JET beamlines were chosen due to their lower cooling water demands and reliable performance on JET.

  17. Absorption heat pump system

    DOEpatents

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  18. Test Results From a Pair of 1-kWe Dual-Opposed Free-Piston Stirling Power Convertors Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Geng, Steven M.; Briggs, Maxwell H.; Penswick, L. Barry; Pearson, J. Boise; Godfroy, Thomas J.

    2011-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1-kW-class free-piston Stirling convertors were modified to operate with a NaK (sodium (Na) and potassium (K)) liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The convertors were successfully tested at the Marshall Space Flight Center (MSFC) from June 6 through July 14, 2009. The convertors were operated for a total test time of 66 hr and 16 min. The tests included (a) performance mapping the convertors over various hot- and cold-end temperatures, piston amplitudes, and NaK flow rates and (b) transient test conditions to simulate various startup (i.e., low-, medium-, and high-temperature startups) and fault scenarios (i.e., loss of heat source, loss of NaK pump, convertor stall, etc.). This report documents the results of this testing

  19. Output power and intracavity intensity profiles of a quasi-continuous end-pumped Nd:YVO4 self-Raman mini laser

    NASA Astrophysics Data System (ADS)

    Kananovich, A. A.; Voitikov, S. V.; Demidovich, A. A.; Danailov, M. B.; Orlovich, V. A.

    2012-01-01

    The paper presents experimental investigation and modeling of an end-pumped quasi-continuous-wave YVO4/Nd:YVO4 mini self-Raman laser. The dependence of the Stokes output power on the pump power in the range from 3 to 17.5 W has been measured. As much as 1.76 W of an average Stokes power, corresponding to a total optical-to-optical conversion efficiency of about 10%, has been obtained. The transverse profiles of the laser (at the fundamental wavelength) and the Stokes beam intensity have been recorded at the output mirror and in the vicinity of the boundary between the pure and Nd-doped parts of the Raman crystal. These distributions have been approximated by the sum of Gaussian and super-Gaussian distributions with corresponding weights. We propose a model of such lasers that takes into account the features of intracavity self-frequency Raman conversion in lasers with highly inhomogeneous non-Gaussian spatial distributions of the pump, laser, and Stokes beam intensity in the cavity. The results of modeling are in good agreement with the experimental data.

  20. An efficient continuous-wave 591 nm light source based on sum-frequency mixing of a diode pumped Nd:GdVO4-Nd:CNGG laser

    NASA Astrophysics Data System (ADS)

    Zhao, Y. D.; Liu, J. H.

    2013-08-01

    We report a laser architecture to obtain continuous-wave (CW) yellow-orange light sources at the 591 nm wavelength. An 808 nm diode pumped a Nd:GdVO4 crystal emitting at 1063 nm. A part of the pump power was then absorbed by the Nd:CNGG crystal. The remaining pump power was used to pump a Nd:CNGG crystal emitting at 1329 nm. Intracavity sum-frequency mixing at 1063 and 1329 nm was then realized in a LiB3O5 (LBO) crystal to reach the yellow-orange radiation. We obtained a CW output power of 494 mW at 591 nm with a pump laser diode emitting 17.8 W at 808 nm.