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Sample records for pumped laser systems

  1. Optically pumped isotopic ammonia laser system

    DOEpatents

    Buchwald, Melvin I.; Jones, Claude R.; Nelson, Leonard Y.

    1982-01-01

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

  2. Diode-pumped laser with improved pumping system

    DOEpatents

    Chang, Jim J.

    2004-03-09

    A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.

  3. A modified pump laser system to pump the titanium sapphire laser

    NASA Technical Reports Server (NTRS)

    Petway, Larry B.

    1990-01-01

    As a result of the wide tunability of the titanium sapphire laser NASA has sited it to be used to perform differential absorption lidar (DIAL) measurements of H2O vapor in the upper and lower troposphere. The titanium sapphire laser can provide a spectrally narrow (0.3 to 1.0 pm), high energy (0.5 to 1.0 J) output at 727, 762, and 940 nm which are needed in the DIAL experiments. This laser performance can be obtained by addressing the line-narrowing issues in a master oscillator and the high energy requirement in a fundamental mode oscillator. By injection seeding, the single frequency property of the master oscillator can produce a line narrow high energy power oscillator. A breadboard model of the titanium sapphire laser that will ultimately be used in NASA lidar atmospheric sensing experiment is being designed. The task was to identify and solve any problem that would arise in the actual laser system. One such problem was encountered in the pump laser system. The pump laser that is designed to pump both the master oscillator and power oscillator is a Nd:YLF laser. Nd:YLF exhibits a number of properties which renders this material an attractive option to be used in the laser system. The Nd:YLF crystal is effectively athermal; it produces essentially no thermal lensing and thermally induced birefringence is generally insignificant in comparison to the material birefringence resulting from the uniaxial crystal structure. However, in application repeated fracturing of these laser rods was experience. Because Nd:YLF rods are not commercially available at the sizes needed for this application a modified pump laser system to replace the Nd:YLF laser rod was designed to include the more durable Nd:YAG laser rods. In this design, compensation for the thermal lensing effect that is introduced because of the Nd:YAG laser rods is included.

  4. Green pumped Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Kuper, Jerry W.; Brown, David C.

    2005-04-01

    Initial experiments with pulsed and CW pumping an alexandrite laser rod at 532 nm are presented. This pumping architecture holds promise for the production of scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

  5. Computer simulation of processes in solid-state laser oscillators and amplifiers with phototube pumping: Laser pumping systems

    NASA Astrophysics Data System (ADS)

    Gradov, V. M.; Kromskiy, G. I.; Mak, A. A.; Sklizkov, G. V.; Fedotov, S. I.; Shcherbakov, A. A.

    1986-03-01

    Optical pumping systems for solid state lasers are evaluated comparatively on the basis of a mathematical model of processes and the results of computer simulation. The principal criterion for comparison is the overall energy efficiency, assuming that two essential requirements are met: a pumping power level adequate for attainment of the emission or amplification threshold and uniform distribution of the pumping radiation density above the threshold level over the active medium. The method covers spherical and cylindrical surfaces. The general algorithm of the solution of the corresponding integral and differential equations was programmed for a self consistent calculation of the pumping system characteristics. The method is applied to two different pumping systems where discharge produces an optically dense plasma and an optically thin plasma respectively. Analysis and calculations are particularized for several known variants of these pumping systems with various modes of laser emission tuning.

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

    DTIC Science & Technology

    1976-12-01

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

  7. Method and system for homogenizing diode laser pump arrays

    SciTech Connect

    Bayramian, Andrew James

    2016-05-03

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

  8. Method and system for homogenizing diode laser pump arrays

    DOEpatents

    Bayramian, Andy J

    2013-10-01

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

  9. Fiber optic systems for diode-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Kozlov, Valery A.; Awad, H. R. I.; Vlasenko, Oleg A.; Zavartsev, Yury D.; Zagumennyi, Alexander I.; Studenikin, Pavel A.; Shcherbakov, Ivan A.; Gordova, M. R.; Kuznetsov, A. V.

    1996-03-01

    Radial nonsymmetrical fiber endface microlenses original fabrication technique has been used for high efficient pump laser diode radiation coupling (up to 93% without AR coating) into the standard optical fibers and for the form of a pump power diagram at the output fiber endfaces. Nd:GdVO4 laser (2.5 mm crystals length) parameters with semiconfocal (output mirror curvature radius 10 cm) and monolith plane mirrors cavities have been measured for different pump diagrams formed by plane endfaces, spherical microlenses, and Selfoc lenses. Compact diode-pumped solid state lasers may be used in optical communications, optical storage, medicine, and other applications. Diode laser (DL)-optical fiber coupling gives several advantages for these pumping systems -- a possibility to combine several DLs radiation, a remote DLs mounting, small size and electrical safety of the laser heads, simple schemes of active crystals cooling, axial symmetry of the pumping beam for longitudinal geometry. In general, high coupling efficiency between a semiconductor light source and optical fiber may be achieved by the use of microlens, formed on the endface of the fiber. In this case bulk optical components between DL and optical fiber are not needed. In addition, the only reflection surface exists in this coupling technique. Different techniques for producing microlenses on a fiber endface have been developed. For example, tapered hemispherical lenses, melted, etched, and polished lenses are commonly used for this coupling. However, all types of such techniques produce in general radial symmetry lenses: therefore, they do not provide efficient coupling between a round fiber core and a nonsymmetrical DL's radiation. In this paper we demonstrate the fabrication technique of fiber endface radial nonsymmetrical microlenses with radii curvature from few micrometers to few tens micrometers by grinding/polishing process. This process may be used for producing different nonspherical microlenses

  10. Laser demonstration and performance characterization of optically pumped Alkali Laser systems

    NASA Astrophysics Data System (ADS)

    Sulham, Clifford V.

    Diode Pumped Alkali Lasers (DPALs) offer a promising approach for high power lasers in military applications that will not suffer from the long logistical trails of chemical lasers or the thermal management issues of diode pumped solid state lasers. This research focuses on characterizing a DPAL-type system to gain a better understanding of using this type of laser as a directed energy weapon. A rubidium laser operating at 795 nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of DPALs at pump intensities between 1.3 and 45 kW/cm2. Linear scaling as high as 32 times threshold is observed, with no evidence of second order kinetics. Comparison of laser characteristics with a quasi-two level analytic model suggests performance near the ideal steady-state limit, disregarding the mode mis-match. Additionally, the peak power scales linearly as high as 1 kW, suggesting aperture scaling to a few cm2 is sufficient to achieve tactical level laser powers. The temporal dynamics of the 100 ns pump and rubidium laser pulses are presented, and the continually evolving laser efficiency provides insight into the bottlenecking of the rubidium atoms in the 2P3/2 state. Lastly, multiple excited states of rubidium and cesium were accessed through two photon absorption in the red, yielding a blue and an IR photon through amplified stimulated emission. Threshold is modest at 0.3 mJ/pulse, and slope efficiencies increase dramatically with alkali concentrations and peak at 0.4%, with considerable opportunity for improvement. This versatile system might find applications for IR countermeasures or underwater communications.

  11. Pumped up Lasers

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Cutting Edge Optronics released the first of potentially three products to result from an SBIR contract with Goddard Space Flight Center. The first commercial result is the WhisperMiniSlab, a diode pump for high performance laser systems. The slab uses a zig-zag path through the laser crystal which eliminates the need for thermal lensing. The result is smaller lasers with better beam quality for use in medical and industrial applications.

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

    NASA Astrophysics Data System (ADS)

    Grivas, Christos

    2016-01-01

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

  13. CW laser pumped emerald laser

    SciTech Connect

    Shand, M.L.; Lai, S.T.

    1984-02-01

    A CW laser-pumped emerald laser is reported. A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity. The laser has been tuned from 728.8 to 809.0 nm. Losses in emerald are larger than those of alexandrite determined in a similar cavity. The present data also indicate that the excited state absorption minimum is shifted from that of alexandrite. 13 references.

  14. Solar pumped, alkali vapor laser

    NASA Astrophysics Data System (ADS)

    Ham, David; Defaccio, Mark A.

    1987-09-01

    High power lasers based in space have been considered as sources for power transmission, laser propulsion, materials processing and space defense. The feasibility of such systems is based on the cost per unit power delivered, with detailed studies indicating that light weight has a greater impact on cost than laser efficiency. Solar radiation is a natural source of power for these devices and two methods for conversion of solar radiation to laser radiation can be considered. An indirectly solar pumped laser would first convert the solar radiation to electricity or longer wavelength blackbody radiation which is then used to power the laser. A directly longer wavelength blackbody radiation which is then used to power the laser. A directly pumped solar laser would utilize a portion of te solar spectrum to directly pump the laser medium, eliminating the intervening step and substantially reducing the systems weight and complexity. Detailed comparisons showed a directly pumped laser with an overall efficiency of only 1.5 percent can compete with an indirectly energized solar laser with an overall efficiency of ten percent. With this in mind, a concept for a directly solar pumped laser was developed based on an alkali vapor (sodium) as the laser medium.

  15. Direct nuclear pumped laser

    DOEpatents

    Miley, George H.; Wells, William E.; DeYoung, Russell J.

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  16. Solar Pumped Laser Microthruster

    NASA Astrophysics Data System (ADS)

    Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W.

    2010-10-01

    The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

  17. SOLAR PUMPED LASER MICROTHRUSTER

    SciTech Connect

    Rubenchik, A M; Beach, R; Dawson, J; Siders, C W

    2010-02-05

    The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

  18. Solar Pumped Laser Microthruster

    SciTech Connect

    Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W.

    2010-10-08

    The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

  19. Diode Pumped Fiber Laser

    DTIC Science & Technology

    1983-07-01

    d AFWU.-TR-83-niO 00 H CO CO iH <^ DIODE PUMPED FIBER LASER Edward L. Glnzton Laboratory Stanford University Stanford, California 94305...RECIPIf NT’S CATALOG NUMBER 4. TITLE Cand Sub(i(/e; DIODE PUMPED FIBER LASER 5 TYPE OF REPORT & PERIOD COVERED Interim Report...external optical cavity made of two miniature flat mirrors, and end- pumped either at 514.5 nm (argon-ion laser ) or near 818 nm ( laser diode ). Coherent

  20. Laser emission of Rhodamine 110--coumarin bifluorophoric systems under coaxial flashlamp pumping

    SciTech Connect

    Geng Zhang, F.; Lian Yu, C.

    1987-07-01

    In this paper the experimental results of the laser emission of Rhodamine 110--coumarin bifluorophoric systems under coaxial flashlamp pumping have been reported. When coumarin 7 is used as a sensitizer, the laser output of Rhodamine 110 is increased by 130% over that without a sensitizer.

  1. Profile homogenization and monitoring for a multiple 100 J diode-laser pumping system

    NASA Astrophysics Data System (ADS)

    Siebold, M.; Podleska, S.; Hein, J.; Bödefeld, R.; Hornung, M.; Schnepp, M.; Sauerbrey, R.

    2005-09-01

    Multi-pass amplification to the 10 joule level for a femto-second CPA laser system is aimed at diode-pumping Yb3+ doped fluoride-phosphate glass with an energy of 240 J at 940 nm. Collimated pump light of 1000 laser diode bars is focussed onto an a circular glass disk with 28mm diameter. A two-sided ring shaped assembly of diode stacks and attached optics is applied for longitudinal pumping. We developed a computer aided optimization routine for positioning single pump foci with size of 4 × 8mm2 to achieve a smooth homogeneously distributed top-hat shaped pump profile with a diameter of 18 mm. For monitoring purpose the pulse energy of each diode stack is measured with a solar panel placed behind a reflecting mirror.

  2. Solar pumped laser

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Hohl, F.; Weaver, W. R. (Inventor)

    1984-01-01

    A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

  3. Pharyngeal pumping continues after laser killing of the pharyngeal nervous system of C. elegans

    SciTech Connect

    Avery, L.; Horvitz, H.R. )

    1989-10-01

    Using a laser microbeam to kill specific subsets of the pharyngeal nervous system of C. elegans, we found that feeding was accomplished by two separately controlled muscle motions, isthmus peristalsis and pumping. The single neuron M4 was necessary and sufficient for isthmus peristalsis. The MC neurons were necessary for normal stimulation of pumping in response to food, but pumping continued and was functional in MC- worms. The remaining 12 neuron types were also unnecessary for functional pumping. No operation we did, including destruction of the entire pharyngeal nervous system, abolished pumping altogether. When we killed all pharyngeal neurons except M4, the worms were viable and fertile, although retarded and starved. Since feeding is one of the few known essential actions controlled by the nervous system, we suggest that most of the C. elegans nervous system is dispensable in hermaphrodites under laboratory conditions. This may explain the ease with which nervous system mutants are isolated and handled in C. elegans.

  4. Luminescent light source for laser pumping and laser system containing same

    DOEpatents

    Hamil, Roy A.; Ashley, Carol S.; Brinker, C. Jeffrey; Reed, Scott; Walko, Robert J.

    1994-01-01

    The invention relates to a pumping lamp for use with lasers comprising a porous substrate loaded with a component capable of emitting light upon interaction of the component with exciting radiation and a source of exciting radiation. Preferably, the pumping lamp comprises a source of exciting radiation, such as an electron beam, and an aerogel or xerogel substrate loaded with a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce light, e.g., visible light, of a suitable band width and of a sufficient intensity to generate a laser beam from a laser material.

  5. 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 (laser pulses, laser diodes such as the 885-nm LDA were used for 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

  6. Fusion reactor pumped laser

    DOEpatents

    Jassby, Daniel L.

    1988-01-01

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

  7. Laser Demonstration and Performance Characterization of an Optically Pumped Alkali Laser System

    DTIC Science & Technology

    2010-09-01

    optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of DPALs at pump intensities between 1.3 and 45 kW/cm2. Linear...section at line center compared to a single Lorentzian approximation by less than 15% for the current experimental conditions.[19] A comparison of... less than predicted by the Lorentzian profile in Figure 12. 36 Figure 20. Slope efficiency reinterpreted as absorbance for (○) 32% output

  8. Blue-green diode-pumped solid state laser system for transcutaneous bilirubinometry in neonatal jaundice

    NASA Astrophysics Data System (ADS)

    Hamza, Mostafa; El-Ahl, Mohammad H. S.; Hamza, Ahmad M.

    2001-01-01

    The authors introduce the design of a blue-green diode- pumped solid-state laser system for transcutaneous measurement of serum bilirubin level in jaundiced new born infant. The system follows the principles of optical bilirubinometry. The choice of wavelengths provides correction for the presence of hemoglobin. The new design is more compact and less expensive.

  9. Explosively pumped laser light

    DOEpatents

    Piltch, Martin S.; Michelotti, Roy A.

    1991-01-01

    A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  10. High average and peak power few-cycle laser pulses delivered by fiber pumped OPCPA system.

    PubMed

    Rothhardt, J; Hädrich, S; Seise, E; Krebs, M; Tavella, F; Willner, A; Düsterer, S; Schlarb, H; Feldhaus, J; Limpert, J; Rossbach, J; Tünnermann, A

    2010-06-07

    We report on a high power optical parametric amplifier delivering 8 fs pulses with 6 GW peak power. The system is pumped by a fiber amplifier and operated at 96 kHz repetition rate. The average output power is as high as 6.7 W, which is the highest average power few-cycle pulse laser reported so far. When stabilizing the seed oscillator, the system delivered carrier-envelop phase stable laser pulses. Furthermore, high harmonic generation up to the 33(th) order (21.8 nm) is demonstrated in a Krypton gas jet. In addition, the scalability of the presented laser system is discussed.

  11. 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.

  12. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    NASA Astrophysics Data System (ADS)

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Kimura, Shigeru; Ito, Kiminori; Tanaka, Yoshihito; Osawa, Hitoshi; Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro; Yamada, Noboru; Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu; Takata, Masaki

    2013-06-01

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge2Sb2Te5 film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width (ΔE/E ˜ 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge2Sb2Te5 phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge2Sb2Te5 layers on laser power.

  13. A stable, high power optically pumped far infrared laser system

    NASA Technical Reports Server (NTRS)

    Farhoomand, Jam; Pickett, Herbert M.

    1988-01-01

    The generation of 1.25 watts of CW laser power at the 119-micron (2522.8 GHz) methanol line is reported. The maximum frequency fluctuation of the free running laser is less than + or - 100 kHz per hour. This laser has also been tested on numerous other lines ranging from 403.7 GHz (HCOOH) to 5260 GHz (CH3OD) with improved power and stability.

  14. Fusion reactor pumped laser

    DOEpatents

    Jassby, D.L.

    1987-09-04

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

  15. LASERS: YAG:Nd laser pumped by an"optical boiler" system

    NASA Astrophysics Data System (ADS)

    Gondra, A. D.; Gradov, V. M.; Dybko, V. V.; Konstantinov, B. A.; Kromskiĭ, G. I.; Rogal'skiĭ, Yu I.; Rozhdestvin, V. N.; Smotryaev, S. A.; Terent'ev, Yu I.; Fefelov, A. P.; Khomenko, S. I.; Shcherbakov, A. A.

    1987-12-01

    New capabilities of an "optical boiler" pumping system, characterized by a high lasing efficiency and a high density of the stored energy, were predicted theoretically and confirmed experimentally. A record lasing efficiency of ~ 2.85% for single pulses was achieved in a pumping system with YAG:Nd rods distributed around a flashlamp when the output energy from one rod was 300 mJ. An increase in the efficiency in excess of 3% was forecast.

  16. Nuclear pumped laser II

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Lee, J. H.; Pinkston, W. T.

    1977-01-01

    The first direct nuclear pumped laser using the He-2-(n,p) H-3 reaction is reported. Lasing took place on the 1.79 microns Ar I transition in a mixture of He-3-Ar at approximately 600 Torr total pressure. It was found that the electrically pulsed afterglow He-Ar laser had the same concentration profile as the nuclear pumped laser. As a result, nuclear lasing was also achieved in He-3-Xe (2.027 micron) and He-3-Kr (2.52 micron). Scaling of laser output with both thermal flux and total pressure as well as minority concentration has been completed. A peak output (He-3-Ar) of 3.7 watts has been achieved at a total pressure of 4 atm. Direct nuclear pumping of He-3-Ne has also been achieved. Nuclear pumping of a He-3-NF3 mixture was attempted, lasing in FI at approximately 7000 A, without success, although the potential lasing transitions appeared in spontaneous emission. Both NF3 and 238UF6 appear to quench spontaneous emission when they constitute more than 1% of the gas mixture.

  17. End-Pumped Monoblock Laser For Eyesafe Targeting Systems

    DTIC Science & Technology

    2006-11-01

    an enabling technology coined the “monoblock laser” due to its one-piece nature and simplicity of manufacture ( Nettleton , 2000). Variations of this...lending their technical as well as programmatic expertise to this effort. We would also like to thank John Nettleton and Dallas Barr of NVESD for...Opt. 36, 20 (1997). Moulton, P.F., “Pumping with diodes,” IEEE Circuits and Devices Magazine 7, 36-40 (1991). Nettleton , J. E., Schilling, B. W

  18. Simulation model of a new solar pumped laser system of Fresnel lens in Helwan of Egypt

    NASA Astrophysics Data System (ADS)

    Abdel-Hadi, Yasser A.

    2012-12-01

    A simulation model of a new solar pumped laser system is tested to be run in Helwan in Egypt as an example of an industrial polluted area. The system is based on concentrating the solar radiation using a Fresnel lens on a laser head fixed on a mount tracking the sun during the day and powered by a DC battery. The model is fed by real solar radiation data in the various seasons in order to know the laser power got from such a system in those conditions. The results showed that the output laser power obtained from this system can be up to 6.2 W in spring, 6.8 W in summer, 2.2 W in autumn and 0.4 W in winter.

  19. Pumping system

    SciTech Connect

    Kime, J.A.

    1987-05-19

    This patent describes a gas-oil production system for pumping formation fluid in a well through a tubing string within which a down hole pump connects to a hydraulic stroking device through a rod string providing the pump including a plunger reciprocally driven by the hydraulic stroking device toward an upper terminal position during a plunger upstroke. The rod string normally supports the weight of a column of fluid and toward a lower terminal position at the end of a plunger downstroke during which the weight of the column fluid is normally transferred to the tubing string through fluid within the pump. The method for detecting when the well is pumped off comprises: supplying working fluid to the hydraulic stroking device to raise the hydraulic stroking device and thereby move the plunger from the lower terminal position to the upper terminal position; and removing the working fluid at a controlled rate from the hydraulic stroking device.

  20. /sup 3/He functions in tokamak-pumped laser systems

    SciTech Connect

    Jassby, D.L.

    1986-10-01

    /sup 3/He placed in an annular cell around a tokamak fusion generator can convert moderated fusion neutrons to energetic ions by the /sup 3/He(n,p)T reaction, and thereby excite gaseous lasants mixed with the /sup 3/He while simultaneously breeding tritium. The total /sup 3/He inventory is about 4 kg for large tokamak devices. Special configurations of toroidal-field magnets, neutron moderators and beryllium reflectors are required to permit nearly uniform neutron current into the laser cell with minimal attenuation. The annular laser radiation can be combined into a single output beam at the top of the tokamak.

  1. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Kim, K. H.; Stock, L. V.

    1986-01-01

    In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

  2. 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.

  3. 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.

  4. High repetition pump-and-probe photoemission spectroscopy based on a compact fiber laser system.

    PubMed

    Ishida, Y; Otsu, T; Ozawa, A; Yaji, K; Tani, S; Shin, S; Kobayashi, Y

    2016-12-01

    The paper describes a time-resolved photoemission (TRPES) apparatus equipped with a Yb-doped fiber laser system delivering 1.2-eV pump and 5.9-eV probe pulses at the repetition rate of 95 MHz. Time and energy resolutions are 11.3 meV and ∼310 fs, respectively, the latter is estimated by performing TRPES on a highly oriented pyrolytic graphite (HOPG). The high repetition rate is suited for achieving high signal-to-noise ratio in TRPES spectra, thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence (p) region. TRPES of polycrystalline bismuth (Bi) at p as low as 30 nJ/mm(2) is demonstrated. The laser source is compact and is docked to an existing TRPES apparatus based on a 250-kHz Ti:sapphire laser system. The 95-MHz system is less prone to space-charge broadening effects compared to the 250-kHz system, which we explicitly show in a systematic probe-power dependency of the Fermi cutoff of polycrystalline gold. We also describe that the TRPES response of an oriented Bi(111)/HOPG sample is useful for fine-tuning the spatial overlap of the pump and probe beams even when p is as low as 30 nJ/mm(2).

  5. High repetition pump-and-probe photoemission spectroscopy based on a compact fiber laser system

    NASA Astrophysics Data System (ADS)

    Ishida, Y.; Otsu, T.; Ozawa, A.; Yaji, K.; Tani, S.; Shin, S.; Kobayashi, Y.

    2016-12-01

    The paper describes a time-resolved photoemission (TRPES) apparatus equipped with a Yb-doped fiber laser system delivering 1.2-eV pump and 5.9-eV probe pulses at the repetition rate of 95 MHz. Time and energy resolutions are 11.3 meV and ˜310 fs, respectively, the latter is estimated by performing TRPES on a highly oriented pyrolytic graphite (HOPG). The high repetition rate is suited for achieving high signal-to-noise ratio in TRPES spectra, thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence (p) region. TRPES of polycrystalline bismuth (Bi) at p as low as 30 nJ/mm2 is demonstrated. The laser source is compact and is docked to an existing TRPES apparatus based on a 250-kHz Ti:sapphire laser system. The 95-MHz system is less prone to space-charge broadening effects compared to the 250-kHz system, which we explicitly show in a systematic probe-power dependency of the Fermi cutoff of polycrystalline gold. We also describe that the TRPES response of an oriented Bi(111)/HOPG sample is useful for fine-tuning the spatial overlap of the pump and probe beams even when p is as low as 30 nJ/mm2.

  6. Direct solar-pumped iodine laser amplifier

    NASA Astrophysics Data System (ADS)

    Han, Kwang S.; Kim, K. H.; Stock, L. V.

    1987-02-01

    The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

  7. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Kim, K. H.; Stock, L. V.

    1987-01-01

    The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

  8. Alexandrite laser pumped by semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Scheps, Richard; Gately, Bernard M.; Myers, Joseph F.; Krasinski, Jerzy S.; Heller, Donald F.

    1990-06-01

    We report the first operation of a direct diode-pumped tunable chromium-doped solid-state laser. A small alexandrite (Cr:BeAl2O4) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using the R1 line at 680.4 nm for the pump transition, and the slope efficiency was 25%. The measured laser output bandwidth was 2.1 nm.

  9. Alexandrite laser pumped by semiconductor lasers

    SciTech Connect

    Scheps, R.; Gately, B.M.; Myers, J.F. ); Krasinski, J.S. ); Heller, D.F. )

    1990-06-04

    We report the first operation of a direct diode-pumped tunable chromium-doped solid-state laser. A small alexandrite (Cr:BeAl{sub 2}O{sub 4}) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using the {ital R}{sub 1} line at 680.4 nm for the pump transition, and the slope efficiency was 25%. The measured laser output bandwidth was 2.1 nm.

  10. Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher M.; Lee, Ja H.

    1991-01-01

    A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement.

  11. 1 W CW diode-pumped Nd:YAG laser for coherent space communication systems

    NASA Astrophysics Data System (ADS)

    Johann, U.; Seelert, W.

    1991-05-01

    A design concept suitable for space applications is proposed on the basis of a diode-pumped Nd:YAG laser transmitter laboratory breadboard; this transmitter must not only furnish the data carrier but also serve as a tracking reference and (in conjunction with a boost amplifier) as a beacon for receiver-station acquisition. The diffraction-limited beam is generated with 6.3-percent electrical-to-optical conversion efficiency. The proposed space communications system will incorporate astigmatically-focused stacked-laser diodes for continuous reliable operation over the course of seven years.

  12. End-Pumped 895 nm Cs Laser

    SciTech Connect

    Beach, R J; Krupke, W F; Kanz, V K; Payne, S A; Dubinskii, M A; Merkle, L D

    2004-02-09

    A scientific demonstration of a Cs laser is described in which the measured slope efficiency is as high as 0.59 W/W using a Ti:Sapphire laser as a surrogate diode-pump. In addition to presenting experimental data, a laser energetics model that accurately predicts laser performance is described and used to model a power-scaled, diode-pumped system.

  13. Diode Pumped Fiber Laser.

    DTIC Science & Technology

    1984-12-01

    molybdium oxide ( GMO ). The best diameter variations obtained so far are on the order of 1%. It is expected that these fibers should exhibit lower...that the absorbed pump power at threshold is given by "P:" hvp 6, 1Pth = (9) O-rf 21 J(0) where SJ 1(0) =J 1(0, 0, ) =ffj soI (x, y, z) ro(x, y, z) dv...epoxy, the argon laser bean ) was first aligned through a fiber at a low power level and then slowly increased. For preliminary tests the laser cavity

  14. Solar Pumped Laser

    DTIC Science & Technology

    1976-09-01

    conductively cooled solar pumped laser, de- signed to prototype space qualiflable level and structurally compatible with the... xenon short-arc lamp and an ellipsoidal reflector. Lamp 1 is the original lamp, obtained and used on the last program and for the first part of this...apertured to about 5 . Two neutral density filters prevent saturation of the detector and provide electrical output compatible with the meter. A reading

  15. Ultrashort-pulse Ti:sapphire laser system pumped by frequency-doubled Nd:glass lasers

    NASA Astrophysics Data System (ADS)

    Bonlie, James D.; Price, Dwight F.; Sullivan, Alan; White, William E.

    1996-05-01

    We report on the development of a Chirped Pulse Amplification system in which the final amplifier is a large Ti:Sapphire disk pumped by a frequency doubled Nd:Glass laser. Using this amplifier we have produced near diffraction limited 120 fs pulses with energies in excess of 1 J. Focusing of these pulses results in peak irradiances exceeding 5 X 1019 W/cm2. The scalability of this amplifier to the 10 - 20 J level is also discussed.

  16. Solar-pumped solid state Nd lasers

    NASA Technical Reports Server (NTRS)

    Williams, M. D.; Zapata, L.

    1985-01-01

    Solid state neodymium lasers are considered candidates for space-based polar-pumped laser for continuous power transmission. Laser performance for three different slab laser configurations has been computed to show the excellent power capability of such systems if heat problems can be solved. Ideas involving geometries and materials are offered as potential solutions to the heat problem.

  17. Experimental evaluation and performance optimization of a flash lamp pumped Er: Glass laser system over temperature extremes

    NASA Astrophysics Data System (ADS)

    Shrivastava, Sachendra K.; Soni, Lokesh; Chaudhari, Ravindra Y.

    2013-05-01

    Experimental evaluation of a flash lamp pumped Er: glass laser over temperature extremes is presented. In this study, first behavior of flash lamp pumped Er: glass laser system has been experimentally investigated over temperature extremes. Next, the generated data during experimentation has been analyzed and system parameters are optimized such that fairly constant laser output is maintained over temperature extremes. This work also enables the development of a compact, simple, low cost, light weight, low repetition rate and high peak power laser source working in eye safe region for defense application.

  18. Laser beam control and diagnostic systems for the copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect

    Bliss, E.S.; Peterson, R.L.; Salmon, J.T.; Thomas, R.A.

    1992-11-01

    The laser system described in the previous paper is used for experiments in which success requires tight tolerances on beam position, direction, and wavefront. Indeed, the optimum performance of the laser itself depends on careful delivery of copper laser light to the dye amplifiers, precise propagation of dye laser beams through restricted amplifier apertures, and accurate monitoring of laser power at key locations. This paper describes the alignment systems, wavefront correction systems, and laser diagnostics systems which ensure that the control requirements of both the laser and associated experiments are met. Because laser isotope separation processes utilize more than one wavelength, these systems monitor and control multiple wavelengths simultaneously.

  19. Transverse-pumped Cs vapor laser

    NASA Astrophysics Data System (ADS)

    Zhdanov, B. V.; Shaffer, M. K.; Sell, J.; Knize, R. J.

    2009-02-01

    Scaling of alkali lasers to higher powers requires combining beams of multiple diode laser pump sources. For longitudinal pumping this can be very complicated if more than four beams are to be combined. In this paper we report a first demonstration of a transversely pumped Cs laser with fifteen laser diode arrays. The LDA pump beams were individually collimated with a beam size of about 1 x 4 cm as measured at a 1 m distance from the diodes. All these beams were incident on a cylindrical lens to be focused and coupled through the side slit of a hollow, cylindrical diffuse reflector which contained the Cs vapor cell. We measured the output power and efficiency of the Cs laser for pump powers up to 200 W at different cell temperatures. Although the values of output power and slope efficiency obtained for this laser system were less than those for a longitudinally pumped alkali laser, these recent results can be significantly improved by using a more optimal laser cavity design. The demonstrated operation of Cs laser with transverse pumping opens new possibilities in power scaling of alkali lasers.

  20. Activation of theMercury Laser System: A Diode-Pumped Solid-State Laser Driver for Inertial Fusion

    SciTech Connect

    Bayramian, A J; Beach, R J; Bibeau, C; Ebbers, C A; Freitas, B L; Kanz, V K; Payne, S A; Schaffers, K I; Skulina, K M; Smith, L K; Tassano, J B

    2001-09-10

    Initial measurements are reported for the Mercury laser system, a scalable driver for rep-rated inertial fusion energy. The performance goals include 10% electrical efficiency at 10 Hz and 100 J with a 2-10 ns pulse length. We report on the first Yb:S-FAP crystals grown to sufficient size for fabricating full size (4 x 6 cm) amplifier slabs. The first of four 160 kW (peak power) diode arrays and pump delivery systems were completed and tested with the following results: 5.5% power droop over a 0.75 ms pulse, 3.95 nm spectral linewidth, far field divergence of 14.0 mrad and 149.5 mrad in the microlensed and unmicrolensed directions respectively, and 83% optical-to-optical transfer efficiency through the pump delivery system.

  1. A 40 W cw Nd:YAG solar laser pumped through a heliostat: a parabolic mirror system

    NASA Astrophysics Data System (ADS)

    Almeida, J.; Liang, D.; Guillot, E.; Abdel-Hadi, Y.

    2013-06-01

    Solar-pumped solid-state lasers are promising for renewable extreme-temperature material processing. Here, we report a significant improvement in solar laser collection efficiency by pumping the most widely used Nd:YAG single-crystal rod through a heliostat-parabolic mirror system. A conical-shaped fused silica light guide with 3D-CPC output end is used to both transmit and compress the concentrated solar radiation from the focal zone of a 2 m diameter parabolic mirror to a 5 mm diameter Nd:YAG rod within a conical pump cavity, which enables multi-pass pumping through the laser rod. 40 W cw laser power is measured, corresponding to 13.9 W m-2 record-high collection efficiency for the solar laser pumped through a heliostat-parabolic mirror system. 2.9% slope efficiency is fitted, corresponding to 132% enhancement over that of our previous pumping scheme. A 209% reduction in threshold pump power is also registered.

  2. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    SciTech Connect

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Osawa, Hitoshi; Kimura, Shigeru; Ito, Kiminori; Tanaka, Yoshihito; Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro; Yamada, Noboru; Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu; Takata, Masaki

    2013-06-15

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge{sub 2}Sb{sub 2}Te{sub 5} film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width ({Delta}E/E {approx} 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge{sub 2}Sb{sub 2}Te{sub 5} layers on laser power.

  3. Flash-lamp-pumped 4 J, 50 Hz Nd:YAG nanosecond laser system for mobile and transportable equipment

    NASA Astrophysics Data System (ADS)

    Mikami, Katsuhiro; Hasegawa, Noboru; Okada, Hajime; Kondo, Shuji; Nishikino, Masaharu; Kawachi, Tetsuya

    2017-08-01

    A simplified flash-lamp pumped high-average-power Nd:YAG nanosecond laser system based on a master oscillator power amplifier platform was developed toward outside laser remote sensing. The performance of the laser system was demonstrated, obtaining 4 J output pulse energy with a 50 Hz operating frequency. Thermal lens effects were compensated for by using only simple image relays and up to 97% of the laser energy could be contained in the focal spot. The developed laser system was constructed using only components suitable for operation under outside conditions.

  4. Analysis of a 10 megawatt space-based solar-pumped neodymium laser system

    NASA Technical Reports Server (NTRS)

    Kurweg, U. H.

    1984-01-01

    A ten megawatt solar-pumped continuous liquid laser system for space applications is examined. It is found that a single inflatable mirror of 434 m diameter used in conjunction with a conical secondary concentrator is sufficient to side pump a liquid neodymium lasant in an annular tube of 6 m length and 1 m outer and 0.8 m inner diameter. About one fourth of intercepted radiation converging on the laser tube is absorbed and one fifth of this radiation is effective in populating the upper levels. The liquid lasant is flowed through the annular laser cavity at 1.9 m/s and is cooled via a heat exchanger and a large radiator surface comparable in size to the concentrating mirror. The power density of incident light within the lasant of approximately 68 watt/cu cm required for cw operation is exceeded in the present annular configuration. Total system weight corresponds to 20,500 kg and is thus capable of being transported to near Earth orbit by a single shuttle flight.

  5. Initial conceptual design study of self-critical nuclear pumped laser systems

    NASA Technical Reports Server (NTRS)

    Rodgers, R. J.

    1979-01-01

    An analytical study of self-critical nuclear pumped laser system concepts was performed. Primary emphasis was placed on reactor concepts employing gaseous uranium hexafluoride (UF6) as the fissionable material. Relationships were developed between the key reactor design parameters including reactor power level, critical mass, neutron flux level, reactor size, operating pressure, and UF6 optical properties. The results were used to select a reference conceptual laser system configuration. In the reference configuration, the 3.2 m cubed lasing volume is surrounded by a graphite internal moderator and a region of heavy water. Results of neutronics calculations yield a critical mass of 4.9 U(235) in the form (235)UF6. The configuration appears capable of operating in a continuous steady-state mode. The average gas temperature in the core is 600 K and the UF6 partial pressure within the lasing volume is 0.34 atm.

  6. Laser diode pumped solid state laser

    SciTech Connect

    Baer, T.M.; Keirstead, M.S.

    1987-04-07

    This patent describes a high-efficiency, laser diode pumped array, frequency doubled, compact solid state laser, comprising: a rare earth doped birefringent solid laser rod selected from the group consisting of Nd:YLF, Nd:YALO having a front end and a back end, the rod producing a polarized output beam; a housing with means holding the laser rod in fixed position in the housing with its front end forward; a laser array having a predetermined wavelength pumping the laser rod, having a output frequency sufficiently matched to the laser rod to pump the laser rod, secured in the housing behind and in optical alignment with the rod; laser cavity means defining a laser cavity mounted in the housing with the laser rod positioned within the cavity, the laser cavity means further including within the cavity an output coupler means; a frequency doubler, positioned to receive a suitably polarized output beam from the laser rod and to halve its wavelength and double its frequency; a polarization means for polarizing the output beam of the laser rod and substantially maintaining a polarization which optimizes frequency doubling at the frequency doubler and means for matching a focused image of the laser diode with a lasing volume of the laser cavity.

  7. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

  8. Primary investigations on the potential of a novel diode pumped Er:YAG laser system for middle ear surgery

    NASA Astrophysics Data System (ADS)

    Stock, Karl; Wurm, Holger; Hausladen, Florian

    2016-02-01

    Flashlamp pumped Er:YAG lasers are successfully used clinically for both precise soft and hard tissue ablation. Since several years a novel diode pumped Er:YAG laser system (Pantec Engineering AG) is available, with mean laser power up to 40 W and pulse repetition rate up to 1 kHz. The aim of the study was to investigate the suitability of the laser system specifically for stapedotomy. Firstly an experimental setup was realized with a beam focusing unit and a computer controlled translation stage to move the samples (slices of porcine bone) with a defined velocity while irradiation with various laser parameters. A microphone was positioned in a defined distance to the ablation point and the resulting acoustic signal of the ablation process was recorded. For comparison, measurements were also performed with a flash lamp pumped Er:YAG laser system. After irradiation the resulting ablation quality and efficacy were determined using light microscopy. Using a high speed camera and "Töpler-Schlierentechnik" the cavitation bubble in water after perforation of a bone slice was investigated. The results show efficient bone ablation using the diode pumped Er:YAG laser system. Also a decrease of the sound level and of the cavitation bubble volume was observed with decreasing pulse duration. Higher repetition rates lead to a slightly increase of thermal side effects but have no influence on the ablation efficiency. In conclusion, these first experiments demonstrate the high potential of the diode pumped Er:YAG laser system for use in middle ear surgery.

  9. Nuclear pumped gas laser research

    NASA Technical Reports Server (NTRS)

    Thom, K.

    1976-01-01

    Nuclear pumping of lasers by fission-fragments from nuclear chain reactions is discussed. Application of the newly developed lasers to spacecraft propulsion or onboard power, to lunar bases for industrial processing, and to earth for utilization of power without pollution and hazards is envisioned. Emphasis is placed on the process by which the fission-fragement kinetic energy is converted into laser light.

  10. Highly efficient end-side-pumped Nd:YAG solar laser by a heliostat-parabolic mirror system.

    PubMed

    Almeida, J; Liang, D; Vistas, C R; Guillot, E

    2015-03-10

    We report a large improvement in the collection and slope efficiency of an Nd:YAG solar laser pumped by a heliostat-parabolic mirror system. A conical fused silica lens was used to further concentrate the solar radiation from the focal zone of a 2 m diameter primary concentrator to a Nd:YAG single-crystal rod within a conical pump cavity, which enabled multipass pumping to the active medium. A 56 W cw laser power was measured, corresponding to 21.1  W/m2 record-high solar laser collection efficiency with the heliostat-parabolic mirror system. 4.9% slope efficiency was calculated, corresponding to 175% enhancement over our previous result.

  11. Investigations on the potential of a novel diode pumped Er:YAG laser system for dental applications

    NASA Astrophysics Data System (ADS)

    Stock, Karl; Hausladen, Florian; Hibst, Raimund

    2012-01-01

    The successful clinical application of the Er:YAG-laser in dentistry is well known, documented by numerous published studies. These lasers are flash lamp pumped systems and emit pulses of typically some 100 μs duration with energies of up to 1 J. Pulse repetition rates can reach up to 100Hz, and mean powers are up to about 8W. As an alternative to these laser systems recently a novel diode pumped Er:YAG laser system (Pantec Engineering AG) became available. This laser can provide a pulse repetition rate up to 2kHz and a mean laser power up to 15W. The aim of the presented study is to investigate the effect of this laser system on dental hard and soft tissue at various irradiation parameters, particular at repetition rates more than 100 Hz. At first an appropriate experimental set-up was realized with a beam delivery and focusing unit, a computer controlled stepper unit with sample holder, and a shutter unit. The stepper unit allows to move the samples (dentin or enamel slides of extracted human teeth, chicken breast, pig bone) with a defined velocity during irradiation by various laser parameters. For rinsing the sample surface a water spray was also included. The laser produced grooves and cuts were analyzed by light microscopy and laser scanning microscopy regarding to the ablation quality, geometry, ablation efficacy, and thermal effects. The grooves in dentin and enamel show a rough surface, typical for Er:YAG laser ablation. The craters are slightly cone shaped with sharp edges on the surface. Water cooling is essential to prevent thermal injury. The ablation efficacy in dentin is comparable to literature values of the flash lamp pumped Er:YAG laser. The cutting of bone and soft tissue is excellent and appears superior to earlier results obtained with flash lamp pumped system. As a further advantage, the broad range of repetition rates allows to widely vary the thermal side effects. In conclusion, these first experiments with a diode pumped Er:YAG laser

  12. Transversely diode-pumped alkali metal vapour laser

    SciTech Connect

    Parkhomenko, A I; Shalagin, A M

    2015-09-30

    We have studied theoretically the operation of a transversely diode-pumped alkali metal vapour laser. For the case of high-intensity laser radiation, we have obtained an analytical solution to a complex system of differential equations describing the laser. This solution allows one to exhaustively determine all the energy characteristics of the laser and to find optimal parameters of the working medium and pump radiation (temperature, buffer gas pressure, and intensity and width of the pump spectrum). (lasers)

  13. 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.

  14. Semiconductor disk laser pumped Cr2+:Znse lasers.

    PubMed

    Hempler, Nils; Hopkins, John-Mark; Rösener, Benno; Rattunde, Marcel; Wagner, Joachim; Fedorov, Vladimir V; Moskalev, Igor S; Mirov, Sergey B; Burns, David

    2009-09-28

    A new flexible pump source, the optically-pumped semiconductor disk laser (SDL), for the Cr(2+):ZnSe laser is reported. The SDL provides up to 6W output power at a free running central wavelength of 1.98 microm. The Cr(2+):ZnSe laser operated at an output power of 1.8W and a slope efficiency of approximately 50% with respect to absorbed pump power whilst maintaining a low output intensity noise figure of <0.14% RMS. The system required no optical isolation even under the situation of significant optical feedback.

  15. An Nd:YAG laser with a 'light reactor' pump system

    NASA Astrophysics Data System (ADS)

    Gondra, A. D.; Gradov, V. M.; Dybko, V. V.; Konstantinov, B. A.; Kromskii, G. I.

    1987-12-01

    New capabilities of a light-reactor pump system associated with high lasing and energy-storage efficiencies are predicted theoretically and confirmed experimentally. For a pump system comprising four Nd:YAG rods placed around the pump lamp, a lasing efficiency of about 2.85 percent was obtained for Q-switched operation with a single-rod output energy of 300 mJ. It is predicted that the efficiency can be raised to a value above 3 percent.

  16. Fusion pumped laser

    DOEpatents

    Pappas, D.S.

    1987-07-31

    The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

  17. Analysis of Nd3+:glass, solar-pumped, high-powr laser systems

    NASA Technical Reports Server (NTRS)

    Zapata, L. E.; Williams, M. D.

    1989-01-01

    The operating characteristics of Nd(3+):glass lasers energized by a solar concentrator were analyzed for the hosts YAG, silicate glass, and phosphate glass. The modeling is based on the slab zigzag laser geometry and assumes that chemical hardening methods for glass are successful in increasing glass hardness by a factor of 4. On this basis, it was found that a realistic 1-MW solar-pumped laser might be constructed from phosphate glass 4 sq m in area and 2 mm thick. If YAG were the host medium, a 1-MW solar-pumped laser need only be 0.5 sq m in area and 0.5 cm thick, which is already possible. In addition, Nd(3+) doped glass fibers were found to be excellent solar-pumped laser candidates. The small diameter of fibers eliminates thermal stress problems, and if their diameter is kept small (10 microns), they propagate a Gaussian single mode which can be expanded and transmitted long distances in space. Fiber lasers could then be used for communications in space or could be bundled and the individual beams summed or phase-matched for high-power operation.

  18. Nuclear-Pumped Lasers. [efficient conversion of energy liberated in nuclear reactions to coherent radiation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The state of the art in nuclear pumped lasers is reviewed. Nuclear pumped laser modeling, nuclear volume and foil excitation of laser plasmas, proton beam simulations, nuclear flashlamp excitation, and reactor laser systems studies are covered.

  19. Diode laser-pumped solid-state lasers

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1988-01-01

    An evaluation is made of the consequences for solid-state lasers of novel diode laser-pumping technology. Diode laser-pumped neodymium lasers have operated at an electrical-to-optical efficiency of 10 percent in a single spatial mode, with linewidths of less than 10 kHz, and with a spectral power brightness sufficiently great to allow frequency extension by harmonic generation in nonlinear crystals; this has yielded green and blue sources of coherent radiation. Q-switched operation with kW peak powers and mode-locked operation with 10-picosec pulse widths have also been demonstrated. All-solid-state lasers at prices comparable to those of current flash-lamp-pumped laser systems are foreseen, as are power levels exceeding 1 kW, for coherent radar, global satellite sensing, and micromachining.

  20. Diode laser-pumped solid-state lasers

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1988-01-01

    An evaluation is made of the consequences for solid-state lasers of novel diode laser-pumping technology. Diode laser-pumped neodymium lasers have operated at an electrical-to-optical efficiency of 10 percent in a single spatial mode, with linewidths of less than 10 kHz, and with a spectral power brightness sufficiently great to allow frequency extension by harmonic generation in nonlinear crystals; this has yielded green and blue sources of coherent radiation. Q-switched operation with kW peak powers and mode-locked operation with 10-picosec pulse widths have also been demonstrated. All-solid-state lasers at prices comparable to those of current flash-lamp-pumped laser systems are foreseen, as are power levels exceeding 1 kW, for coherent radar, global satellite sensing, and micromachining.

  1. Diode pumped tunable dye laser

    NASA Astrophysics Data System (ADS)

    Burdukova, O.; Gorbunkov, M.; Petukhov, V.; Semenov, M.

    2017-03-01

    A wavelength-tunable dye laser pumped by blue laser diodes (λ =445 nm) in a 200 ns pulsed mode has been developed. We used a 3-mirror cavity with transverse excitation and total internal reflection of laser beam in the active element. Tuning curves for 8 dyes in benzyl alcohol were measured in the range of 506-700 nm. Four dyes have their tuning range more than 60 nm, which is comparable to the tuning ranges of other dye lasers pumped by more expensive sources. The output energy obtained at the generation maximum of both DCM and coumarin 540A dyes was approximately 130 nJ while the pump energy was 2400 nJ.

  2. Optically pumped molecular bromine laser. Master's thesis

    SciTech Connect

    Morrison, J.W.

    1990-12-01

    An optically pumped molecular bromine laser was studied to investigate the quenching kinetics state of Br2. This included characterization of the pressure dependence of the laser output power. The approach was to excite molecular bromine in a sealed cell with a Nd:YAG pumped dye laser. Unresolved side fluorescence and amplified stimulated emission (ASE) spectra were recorded. ASE offered the advantage of a simpler optical system with no externally induced wavelength dependencies. Stimulated emission as a signal monitor offered greater resolution than side fluorescence spectra and facilitated spectroscopic assignment. (JS)

  3. Intensity Scaling for Diode Pumped Alkali Lasers

    DTIC Science & Technology

    2012-01-01

    unphased diode lasers is absorbed in the near IR by atomic potassium, rubidium , or cesium. The gain cell for a DPAL system using a heat pipe design is...demonstrated linear scaling of a rubidium laser to 32 times threshold.3 In our present work, we explore scaling to pump in- tensities of >100kW/cm2. The...of output power. Each alkali atom in the laser medium may be required to cycle as many as 1010 pump photons per second. We demonstrated a rubidium

  4. High-energy transversely pumped alkali vapor laser

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Komashko, A.

    2011-03-01

    We report on the results from our transversely pumped alkali laser. This system uses an Alexandrite laser to pump a stainless steel laser head. The system uses methane and helium as buffer gasses. Using rubidium, the system produced up to 40 mJ of output energy when pumped with 63 mJ. Slope efficiency was 75%. Using potassium as the lasing species the system produced 32 mJ and a 53% slope efficiency.

  5. Selective Emitter Pumped Rare Earth Laser

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L. (Inventor); Patton, Martin O. (Inventor)

    2001-01-01

    A selective emitter pumped rare earth laser provides an additional type of laser for use in many laser applications. Rare earth doped lasers exist which are pumped with flashtubes or laser diodes. The invention uses a rare earth emitter to transform thermal energy input to a spectral band matching the absorption band of a rare earth in the laser in order to produce lasing.

  6. Energy level systems and transitions of Ho:LuAG laser resonantly pumped by a narrow line-width Tm fiber laser.

    PubMed

    Chen, Hao; Zhao, Ting; Yang, Hao; Zhang, Le; Zhou, Tianyuan; Tang, Dingyuan; Wong, Chingping; Chen, Yung-Fu; Shen, Deyuan

    2016-11-28

    We presented a Ho:LuAG ceramic laser in-band pumped by a narrow emission line-width Tm fiber laser at 1907 nm. All of potential transitions between 5I7 and 5I8 manifold were discussed to form the Ho's in-band-pump energy level systems, which were not described in details earlier. For the emission band centered at ~2095 nm, both laser absorption and emission transition separately consisted of two groups were first analyzed and observed. Using output couplers (OCs) with different transmittances (T = 6, 10 and 20%), the similar ~0.5 W continuous-wave (CW) output power under an incident pump power of ~4.9 W was obtained, with twin (or triplet) emission bands respectively. The blue shift of center emission wavelengths was observed with the increase of transmittances.

  7. Heat pump processes induced by laser radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.

    1980-01-01

    A carbon dioxide laser system was constructed for the demonstration of heat pump processes induced by laser radiation. The system consisted of a frequency doubling stage, a gas reaction cell with its vacuum and high purity gas supply system, and provisions to measure the temperature changes by pressure, or alternatively, by density changes. The theoretical considerations for the choice of designs and components are dicussed.

  8. Studies of blackbody-pumped lasers

    NASA Technical Reports Server (NTRS)

    Christiansen, W. H.; Chang, J.; Sirota, M.

    1988-01-01

    Laser action was achieved in a large-scale pulsed system and meaningful experiments were carried out in the axial flow facility to understand the physics of solar-pumped lasers. Studies of the variation of laser mixture composition were done for mixtures of CO2 and N2O additions. Theoretical analysis and modeling of the system were also performed based on a model including radiative pumping, diffusion and wall deactivation, and vibrational energy transfer between two optically active species. Qualitative agreement between predictions in the parameter variation and the experimental results were obtained with CO and N2O mixtures. Several experimental studies were performed to quantify the properties of carbon monoxide as absorber and storage of energy in the blackbody pumped system.

  9. Transverse pumped laser amplifier architecture

    DOEpatents

    Bayramian, Andrew James; Manes, Kenneth R.; Deri, Robert; Erlandson, Alvin; Caird, John; Spaeth, Mary L.

    2015-05-19

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

  10. Transverse pumped laser amplifier architecture

    DOEpatents

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

    2013-07-09

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

  11. Generation of radio frequency induced metastable xenon as a gain medium for diode pumped rare gas laser systems

    NASA Astrophysics Data System (ADS)

    Andreozzi, Jacqueline Marie

    The pursuit of novel, hybrid methods of achieving lasing from the rare gases has recently been a topic of interest in the field of high energy laser systems. This investigation presents the construction and execution of an experimental setup designed to generate metastable xenon (Xe*) to determine its potential to perform as a high power laser gain medium in a similar capacity as the alkali metals in Diode Pumped Alkali Lasers. A capacitively coupled radio frequency discharge was used to light plasma from naturally abundant xenon, thus exciting the 6s[3/2]2 metastable state. The metastable xenon was probed with a tunable diode laser at 882.2 and 904.8 nanometers, and absorption was detected to verify the presence of Xe* atoms. The absorption profiles are reported with in-depth calculations of the isotope shift and hyperfine structure of each absorption line. Preliminary calculations for the properties of the proposed laser system are also presented.

  12. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  13. New laser materials for laser diode pumping

    NASA Technical Reports Server (NTRS)

    Jenssen, H. P.

    1990-01-01

    The potential advantages of laser diode pumped solid state lasers are many with high overall efficiency being the most important. In order to realize these advantages, the solid state laser material needs to be optimized for diode laser pumping and for the particular application. In the case of the Nd laser, materials with a longer upper level radiative lifetime are desirable. This is because the laser diode is fundamentally a cw source, and to obtain high energy storage, a long integration time is necessary. Fluoride crystals are investigated as host materials for the Nd laser and also for IR laser transitions in other rare earths, such as the 2 micron Ho laser and the 3 micron Er laser. The approach is to investigate both known crystals, such as BaY2F8, as well as new crystals such as NaYF8. Emphasis is on the growth and spectroscopy of BaY2F8. These two efforts are parallel efforts. The growth effort is aimed at establishing conditions for obtaining large, high quality boules for laser samples. This requires numerous experimental growth runs; however, from these runs, samples suitable for spectroscopy become available.

  14. Efficient analytic model to optimum design laser resonator and optical coupling system of diode-end-pumped solid-state lasers: influence of gain medium length and pump beam M2 factor.

    PubMed

    Shayeganrad, Gholamreza; Mashhadi, Leila

    2008-02-10

    A comprehensive analytical model for optimization longitudinal pumping of ideal four-level lasers is presented for accurate analysis by removing limiting assumptions on active length and pump-beam radius in the gain medium. By taking into account the circular-symmetric Gaussian pump beam including the M2 factor, an analytical formula for the root mean square of the pump beam in the active medium is developed to relate properties of the gain medium and pump beam to the requirement on efficient optimum design. Under the condition of minimum root mean square of pump-beam radius inside the active medium, the key parameters of the optimum optical coupling system have been analytically derived. Using these parameters, optimum mode size and maximum output efficiency are derived as a function of the gain medium length, absorption coefficient, pump-beam M2 factor, and input power. Dependence of the obtained parameters on the gain medium length, absorption coefficient, pump-beam M2 factor, and input power has been investigated. The results of this theory are found to be more comprehensive than the previous theoretical investigations. The present model provides a straightforward procedure to design the optimum laser resonator and the coupling optics for maximizing the output.

  15. Electron beam pumped semiconductor laser

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor)

    2009-01-01

    Electron-beam-pumped semiconductor ultra-violet optical sources (ESUVOSs) are disclosed that use ballistic electron pumped wide bandgap semiconductor materials. The sources may produce incoherent radiation and take the form of electron-beam-pumped light emitting triodes (ELETs). The sources may produce coherent radiation and take the form of electron-beam-pumped laser triodes (ELTs). The ELTs may take the form of electron-beam-pumped vertical cavity surface emitting lasers (EVCSEL) or edge emitting electron-beam-pumped lasers (EEELs). The semiconductor medium may take the form of an aluminum gallium nitride alloy that has a mole fraction of aluminum selected to give a desired emission wavelength, diamond, or diamond-like carbon (DLC). The sources may be produced from discrete components that are assembled after their individual formation or they may be produced using batch MEMS-type or semiconductor-type processing techniques to build them up in a whole or partial monolithic manner, or combination thereof.

  16. Compact and highly efficient laser pump cavity

    DOEpatents

    Chang, Jim J.; Bass, Isaac L.; Zapata, Luis E.

    1999-01-01

    A new, compact, side-pumped laser pump cavity design which uses non-conventional optics for injection of laser-diode light into a laser pump chamber includes a plurality of elongated light concentration channels. In one embodiment, the light concentration channels are compound parabolic concentrators (CPC) which have very small exit apertures so that light will not escape from the pumping chamber and will be multiply reflected through the laser rod. This new design effectively traps the pump radiation inside the pump chamber that encloses the laser rod. It enables more uniform laser pumping and highly effective recycle of pump radiation, leading to significantly improved laser performance. This new design also effectively widens the acceptable radiation wavelength of the diodes, resulting in a more reliable laser performance with lower cost.

  17. Sunlight-Pumped Laser

    NASA Technical Reports Server (NTRS)

    Weaver, W. R. J.; Lee, J. H.

    1982-01-01

    Organic iodide gas is stimulated by portion of Sun's spectrum to emit laser light. Chopper forms pulses from beam of Xenon-Arc light. Chopper is only necessary to avoid buildup of laser-quenching species in sealed tube of present experiment. Perfluoropropyliodide lasing medium functions at temperatures of about 670 K, a fact that reduces cooling requirements in space.

  18. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Hwang, In H.; Stock, Larry V.

    1988-01-01

    A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of this improvement the output energy from the XeCl laser was increased from 60 mj to 80 mj. Subsequently, iodine laser output energy was increased from 100 mj to 3 mj. On the other hand, the energy storage capability and amplification characteristics of the Vortek solar simulator-pumped amplifier was calculated expecting the calculated amplification factor is about 2 and the energy extraction efficiency is 26 percent due to the very low input energy density to the amplifier. As a result of an improved kinetic modeling for the iodine solar simulator pumped power amplifier, it is found that the I-2 along the axis of the tube affects seriously the gain profile. For the gas i-C3F7I at the higher pressures, the gain will decrease due to the I-2 as the pumping intensity increases, and at these higher pressures an increase in flow velocity will increase the gain.

  19. BOTDA sensing system employing a tunable low-cost Brillouin fiber ring laser pump-probe source

    NASA Astrophysics Data System (ADS)

    Iuliano, M.; Marini, D.; Bastianini, F.; Bolognini, G.

    2017-04-01

    In this paper we show a Brillouin optical time-domain analysis (BOTDA) sensing system experiment employing a tunable narrow-linewidth dual pump-probe source based on modified Brillouin ring laser technology. The developed cost-effective source generates a pump-locked and tunable probe light, with wavelength shift and a large tuning range ( 200 MHz), narrow linewidth (<2.5 MHz) and adequate power ( 0.5 mW). The developed source was hence employed in BOTDA system experiments providing distributed sensing over 10 km single mode optical fiber, and attaining strain and temperature resolutions of 10μɛ and 0.5 °C respectively, indicating the pump-probe source as an efficient and cost-effective solution for BOTDA avoiding high-frequency signal generators or complex locking techniques.

  20. Solar Pumped, Alkali Vapor Laser.

    DTIC Science & Technology

    1987-09-04

    tempature we extrapolated to higher temperatures by multiplying the cross...for broadband optical pumping. Tempature profiles for both the axial direction and the vertical direction were made utilizing the LIF method explained...laser in the crossed heat .: pi pe oven. .. 1 ;mirro len Lasing was achieved at a minimum tempature in the crossed heat pipe oven of around 400 C

  1. Algorithm for evaluation of temperature distribution of a vapor cell in a diode-pumped alkali laser system (part II).

    PubMed

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

    2015-04-06

    With high efficiency and small thermally-induced effects in the near-infrared wavelength region, a diode-pumped alkali laser (DPAL) is regarded as combining the major advantages of solid-state lasers and gas-state lasers and obviating their main disadvantages at the same time. Studying the temperature distribution in the cross-section of an alkali-vapor cell is critical to realize high-powered DPAL systems for both static and flowing states. In this report, a theoretical algorithm has been built to investigate the features of a flowing-gas DPAL system by uniting procedures in kinetics, heat transfer, and fluid dynamic together. The thermal features and output characteristics have been simultaneously obtained for different gas velocities. The results have demonstrated the great potential of DPALs in the extremely high-powered laser operation.

  2. All solid-state mode-locked flashlamp pumped Nd:YAG laser system with selectable pulse duration

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

    All solid state mode-locked flashlamp pumped Nd:YAG laser system with selectable pulse duration was developed based on the oscillator where a single semiconductor structure containing a multiple-quantum-well was used as a saturable absorber for mode-locking, and energy limiter for passive negative feedback. Single pulse selection from various parts of extended 200 ns long Q-switched pulse train enables the changing of pulse duration before entering into three stages of laser amplifiers. Using of additional acousto-optic mode-locker, stability enhancement of the output pulses was obtained and the amplitude fluctuations were reduced below 5%. The exploitation of the solid state saturable absorber and limiter integrated in the single element improved significantly the long term characteristics of the laser system which can be therefore used for various applications as a satellite laser ranging, spectroscopy, or medicine.

  3. Calculation and comparison of thermal effect in laser diode pumped slab lasers with different pumping structures

    NASA Astrophysics Data System (ADS)

    Huang, Feng; Jiang, Nan; Wang, Yuefeng; Dong, Wei; Niu, Yanxiong

    2008-03-01

    Laser diode (LD) pumped slab laser, as an important high average power solid-state laser, is a promising laser source in military and industrial fields. The different laser diode pumping structures lead to different thermal effect in the slab gain medium. The thermal and stress analysis of slab laser with different pumping structure are performed by finite element analysis (FEA) with the software program ANSYS. The calculation results show that the face pumped and cooled laser results in a near one-dimension temperature distribution and eliminates thermal stress induced depolarization. But the structure is low pump efficiency due to the small thickness of slabs and the requirement to cool and pump through the same faces. End-pumped slab laser is high pump efficiency and excellent mode match, but its pumping arrangement is fairly complicated. The edge-pumped face-cooling slab laser's pump efficiency is better than face-pumping, and its pumping structure is simpler than end-pumped laser, but the tensile stress on surfaces may initiate failure of the gain medium so it is important to design so that the stress is well below the stress fracture limit. The comparison of the thermal effects with different pumping structure shows that, the edge-pumped slab laser has engineering advantages in high power slab laser's application. Furthermore, the end-pumped slab laser tends to get the best beam quality, so it is fit for the application which has a special requirement on laser beam quality.

  4. Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space

    NASA Technical Reports Server (NTRS)

    Monson, D. J.

    1978-01-01

    Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

  5. Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space

    NASA Technical Reports Server (NTRS)

    Monson, D. J.

    1978-01-01

    Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

  6. Ho:YLF Laser Pumped by TM:Fiber Laser

    NASA Astrophysics Data System (ADS)

    Mizutani, Kohei; Ishii, Shoken; Itabe, Toshikazu; Asai, Kazuhiro; Sato, Atsushi

    2016-06-01

    A 2-micron Ho:YLF laser end-pumped by 1.94-micron Tm:fiber laser is described. A ring resonator of 3m length is adopted for the oscillator. The laser is a master oscillator and an amplifier system. It is operated at high repetition rate of 200-5000 Hz in room temperature. The laser outputs were about 9W in CW and more than 6W in Q-switched operation. This laser was developed to be used for wind and CO2 measurements.

  7. Scaling studies of solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Christiansen, W. H.; Chang, J.

    1985-01-01

    A progress report of scaling studies of solar pumped lasers is presented. Conversion of blackbody radiation into laser light has been demonstrated in this study. Parametric studies of the variation of laser mixture composition and laser gas temperature were carried out for CO2 and N2O gases. Theoretical analysis and modeling of the system have been performed. Reasonable agreement between predictions in the parameter variation and the experimental results have been obtained. Almost 200 mW of laser output at 10.6 micron was achieved by placing a small sapphire laser tube inside an oven at 1500 K the tube was filled with CO2 laser gas mixture and cooled by longitudinal nitrogen gas flow.

  8. Scaling studies of solar pumped lasers

    NASA Astrophysics Data System (ADS)

    Christiansen, W. H.; Chang, J.

    1985-08-01

    A progress report of scaling studies of solar pumped lasers is presented. Conversion of blackbody radiation into laser light has been demonstrated in this study. Parametric studies of the variation of laser mixture composition and laser gas temperature were carried out for CO2 and N2O gases. Theoretical analysis and modeling of the system have been performed. Reasonable agreement between predictions in the parameter variation and the experimental results have been obtained. Almost 200 mW of laser output at 10.6 micron was achieved by placing a small sapphire laser tube inside an oven at 1500 K the tube was filled with CO2 laser gas mixture and cooled by longitudinal nitrogen gas flow.

  9. Concept of the solar-pumped laser-photovoltaics combined system and its application to laser beam power feeding to electric vehicles

    NASA Astrophysics Data System (ADS)

    Motohiro, Tomoyoshi; Takeda, Yasuhiko; Ito, Hiroshi; Hasegawa, Kazuo; Ikesue, Akio; Ichikawa, Tadashi; Higuchi, Kazuo; Ichiki, Akihisa; Mizuno, Shintaro; Ito, Tadashi; Yamada, Noboru; Nath Luitel, Hom; Kajino, Tsutomu; Terazawa, Hidetaka; Takimoto, Satoshi; Watanabe, Kemmei

    2017-08-01

    We have developed a compact solar-pumped laser (µSPL) employing an off-axis parabolic mirror with an aperture of 76.2 mm diameter and an yttrium aluminum garnet (YAG) ceramic rod of φ1 mm × 10 mm doped with 1% Nd and 0.1% Cr as a laser medium. The laser oscillation wavelength of 1.06 µm, just below the optical absorption edge of Si cells, is suitable for photoelectric conversion with minimal thermal loss. The concept of laser beam power feeding to an electric vehicle equipped with a photovoltaic panel on the roof was proposed by Ueda in 2010, in which the electricity generated by solar panels over the road is utilized to drive a semiconductor laser located on each traffic signal along the road. By substituting this solar-electricity-driven semiconductor laser with a solar-pumped laser, the energy loss of over 50% in converting the solar electricity to a laser beam can be eliminated. The overall feasibility of this system in an urban area such as Tokyo was investigated.

  10. Grazing Incidence Pumping for Efficient X-ray Lasers

    SciTech Connect

    Dunn, J; Keenan, R; Patel, P K; Price, D F; Smith, R F; Shlyaptsev, V N

    2004-09-30

    We report progress in developing efficient pumping of laser-driven x-ray lasers that opens new possibilities for both high average power x-ray lasers as well as producing progressively shorter wavelength lasers. The new scheme of grazing incidence pumping (GRIP) is described. In essence, a chosen electron density region of a pre-formed plasma column, produced by a longer pulse at normal incidence onto a slab target, is selectively pumped by focusing the short pulse {approx}ps laser at a determined grazing incidence angle to the target. The controlled use of refraction of the pumping laser in the plasma results in several benefits: The pump laser path length is longer and there is an increase in the laser absorption in the gain region for creating a collisional Ni-like ion x-ray laser. There is also an inherent traveling wave, close to c, that increases the overall pumping efficiency. The scheme requires careful tailoring of the pump and plasma conditions to the specific x-ray laser under investigation but the main advantage is a 3 - 30 times reduction in the laser pump energy for mid-Z materials. We report several examples of this new x-ray laser on two different laser systems. The first demonstrates a 10 Hz x-ray laser operating at 18.9 nm pumped with a total of 150 mJ of 800 nm wavelength from a Ti:Sapphire laser. The second case is shown where the COMET laser is used both at 527 nm and 1054 nm wavelength to pump higher Z materials with the goal of extending the wavelength regime of tabletop x-ray lasers below 10 nm.

  11. Optically pumped microplasma rare gas laser.

    PubMed

    Rawlins, W T; Galbally-Kinney, K L; Davis, S J; Hoskinson, A R; Hopwood, J A; Heaven, M C

    2015-02-23

    The optically pumped rare-gas metastable laser is a chemically inert analogue to three-state optically pumped alkali laser systems. The concept requires efficient generation of electronically excited metastable atoms in a continuous-wave (CW) electric discharge in flowing gas mixtures near atmospheric pressure. We have observed CW optical gain and laser oscillation at 912.3 nm using a linear micro-discharge array to generate metastable Ar(4s, 1s(5)) atoms at atmospheric pressure. We observed the optical excitation of the 1s(5) → 2p(9) transition at 811.5 nm and the corresponding fluorescence, optical gain and laser oscillation on the 2p(10) ↔ 1s(5) transition at 912.3 nm, following 2p(9)→2p(10) collisional energy transfer. A steady-state kinetics model indicates efficient collisional coupling within the Ar(4s) manifold.

  12. High efficiency CW green-pumped alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Kuper, J. W.; Brown, D. C.

    2006-02-01

    High power, CW and pulsed alexandrite lasers were produced by pumping the laser rod with a high quality diode pumped 532 nm laser sources. This pumping architecture provides stable performance with output power > 1.4 W at 767nm in the free running mode and 0.78W at 1000 Hz. An output of 80 mW at 375.5 nm was achieved at 500 Hz. This approach holds promise for the production of a scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

  13. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, K. S.

    1985-01-01

    This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

  14. Fusion pumped laser

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

  15. APPLICATIONS OF LASERS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Laser system based on a commercial microwave oscillator with time compression of a microwave pump pulse

    NASA Astrophysics Data System (ADS)

    Arteev, M. S.; Vaulin, V. A.; Slinko, V. N.; Chumerin, P. Yu; Yushkov, Yu G.

    1992-06-01

    An analysis is made of the possibility of using a commercial microsecond microwave oscillator, supplemented by a device for time compression of microwave pulses, in pumping of industrial lasers with a high efficiency of conversion of the pump source energy into laser radiation. The results are reported of preliminary experiments on the commissioning of an excimer XeCl laser.

  16. Diode Pumped Fiber Laser.

    DTIC Science & Technology

    1987-08-01

    mounting fixture beeame soft and gradually come out of the fixture. S)me chemical reaction was takin- place between the epoxy and the dye solvent , which...loose. The solvent apparenlly did no)t affect the bonding agent used to attach the fibers inside the capillarie,. \\lthmigh individual capillarv tubes...pure solvent . was added to the cavity laser oscillation ceased, and was onlv re, ,t()red after readjuisting the orientation of the output coupler, as

  17. Prototype laser-diode-pumped solid state laser transmitters

    NASA Technical Reports Server (NTRS)

    Kane, Thomas J.; Cheng, Emily A. P.; Wallace, Richard W.

    1989-01-01

    Monolithic, diode-pumped Nd:YAG ring lasers can provide diffraction-limited, single-frequency, narrow-linewidth, tunable output which is adequate for use as a local oscillator in a coherent communication system. A laser was built which had a linewidth of about 2 kHz, a power of 5 milliwatts, and which was tunable over a range of 30 MHz in a few microseconds. This laser was phase-locked to a second, similar laser. This demonstrates that the powerful technique of heterodyne detection is possible with a diode-pumped laser used as the local oscillator. Laser diode pumping of monolithic Nd:YAG rings can lead to output powers of hundreds of milliwatts from a single laser. A laser was built with a single-mode output of 310 mW. Several lasers can be chained together to sum their power, while maintaining diffraction-limited, single frequency operation. This technique was demonstrated with two lasers, with a total output of 340 mW, and is expected to be practical for up to about ten lasers. Thus with lasers of 310 mW, output of up to 3 W is possible. The chaining technique, if properly engineered, results in redundancy. The technique of resonant external modulation and doubling is designed to efficiently convert the continuous wave, infrared output of our lasers into low duty-cycle pulsed green output. This technique was verified through both computer modeling and experimentation. Further work would be necessary to develop a deliverable system using this technique.

  18. Optically pumped rare-gas lasers

    SciTech Connect

    Mikheyev, P A

    2015-08-31

    The modern state of the research of a new promising optically pumped laser system with an active medium formed by metastable rare-gas atoms is briefly reviewed. The kinetics of these media is similar to that of laser media based on alkali metal vapour; however, the gas medium is inert. Metastable atoms can be produced in an electric discharge. As in alkali lasers, the specific laser power output under atmospheric pressure can be several hundreds of watts per 1 cm{sup 3}. The lasing wavelengths lie in the near-IR range and fall in the transparency window of the terrestrial atmosphere. This new concept makes it possible to develop a closed-cycle cw laser with megawatt power levels and high beam quality. (lasers)

  19. Diode-pumped laser altimeter

    NASA Technical Reports Server (NTRS)

    Welford, D.; Isyanova, Y.

    1993-01-01

    TEM(sub 00)-mode output energies up to 22.5 mJ with 23 percent slope efficiencies were generated at 1.064 microns in a diode-laser pumped Nd:YAG laser using a transverse-pumping geometry. 1.32-micron performance was equally impressive at 10.2 mJ output energy with 15 percent slope efficiency. The same pumping geometry was successfully carried forward to several complex Q-switched laser resonator designs with no noticeable degradation of beam quality. Output beam profiles were consistently shown to have greater than 90 percent correlation with the ideal TEM(sub 00)-order Gaussian profile. A comparison study on pulse-reflection-mode (PRM), pulse-transmission-mode (PTM), and passive Q-switching techniques was undertaken. The PRM Q-switched laser generated 8.3 mJ pulses with durations as short as 10 ns. The PTM Q-switch laser generated 5 mJ pulses with durations as short as 5 ns. The passively Q-switched laser generated 5 mJ pulses with durations as short as 2.4 ns. Frequency doubling of both 1.064 microns and 1.32 microns with conversion efficiencies of 56 percent in lithium triborate and 10 percent in rubidium titanyl arsenate, respectively, was shown. Sum-frequency generation of the 1.064 microns and 1.32 microns radiations was demonstrated in KTP to generate 1.1 mJ of 0.589 micron output with 11.5 percent conversion efficiency.

  20. Raman soliton generation in microstructured tellurite fiber pumped by hybrid Erbium/Thulium fiber laser system

    NASA Astrophysics Data System (ADS)

    Anashkina, E. A.; Koptev, M. Y.; Muravyev, S. V.; Dorofeev, V. V.; Andrianov, A. V.; Kim, A. V.

    2016-08-01

    We demonstrate a fibre laser source generating ultrashort pulses tunable in the range 2-2.5 μm. The source is based on a hybrid Er/Tm fiber laser system and microstructured suspended-core tellurite fiber where Raman soliton shifting occurs. Nonlinear soliton dynamics is studied and possibility of tuning beyond 3 μm is shown.

  1. Volumetric direct nuclear pumped laser

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Hohl, F.; Deyoung, R. J.; Williams, M. D. (Inventor)

    1978-01-01

    A volumetric direct nuclear pumped laser was developed in which the gas is a mixture of He-3 and a minority gas from the group of argon, krypton, xenon, chlorine and fluorine. The mixture of He-3 and the minority gas produces lasing with a minority gas concentration of from 0.01 to 10 percent argon, 1 percent krypton, 0.01 to 5 percent xenon and small concentrations of chlorine or fluorine.

  2. Q-switched hybrid MOPA laser system based on Yb fibre with side pumping by single source

    NASA Astrophysics Data System (ADS)

    Kobtsev, Sergey; Kukarin, Sergey; Fedotov, Yurii

    2009-02-01

    A novel fiber-based Q-switched master-oscillator & power-amplifier system was developed by using non-PM Yb fiber with side pumping by single source. The passive Q-switched system provides for pulse energy up to 110 microjoule at CW 12 W single pump. Duration and repetition rate of generated pulses at 1080 nm can be varied from 280 ns to 1,8 microsecond, and in the range of 45-140 kHz depending on pump power at 980 nm. Design of master oscillator ensures linearly polarized output which remains polarized after passing power amplifier. Maximum stable average output of the system was 5 W and above this value we observed appearance of nonregular giant pulses which were able to initiate supercontinuum generation over 550-1750 nm range in relatively short-length microstructured fibre. For the first time to our knowledge, wideband supercontinuum generation was obtained with microsecond laser system pump. More details and results including applications for materials processing will be presented.

  3. Blackbody-pumped CO2 laser experiment

    NASA Astrophysics Data System (ADS)

    Christiansen, W. H.; Insuik, R. J.

    1983-07-01

    Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping. Previously announced in STAR as N83-10420

  4. A new concept for solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Christiansen, W. H.

    1978-01-01

    A new approach is proposed in which an intermediate body heated by sunlight is used as the pumping source for IR systems, i.e., concentration solar radiation is absorbed and reradiated via an intermediate blackbody. This body is heated by focused sunlight to a high temperature and its heat losses are engineered to be small. The cooled laser tube (or tubes) is placed within the cavity and is pumped by it. The advantage is that the radiation spectrum is like a blackbody at the intermediate temperature and the laser medium selectively absorbs this light. Focusing requirements, heat losses, and absorption bandwidths of laser media are examined, along with energy balance and potential efficiency. The results indicate that for lasers pumped through an IR absorption spectrum, the use of an intermediate blackbody offers substantial and important advantages. The loss in radiative intensity for optical pumping by a lower-temperature body is partly compensated by the increased solid angle of exposure to the radiative environment.

  5. A 2μm-pump laser-based DIRCM system and aero-optics in the mid-IR

    NASA Astrophysics Data System (ADS)

    Renz, Günther; Bohn, Willy

    2007-10-01

    The improvement of the security of platforms (aircrafts) with countermeasure techniques in the mid-IR especially in the take-off or landing phase is nowadays more stringent due to upcoming threats. We report on the development of a Tm:YLF-fiber laser (1.908 μm) pumped Ho:YAG (2.09 µm) high energy laser system with pulse energies up to 100 mJ at pulse lengths close to 20 ns and repetition rates of 100 Hz. A high quality laser beam leaving a platform through a variable-index-of-refraction airflow will experience wave-front aberrations and consequently lose its ability to be perfectly focused in the far field. Two main causes of laser beam degradations are issued in this investigation. First, there is the degradation immediately around the fuselage, referred to aero-optic problems and second the atmospheric propagation influence via air turbulence. The aero-optic influence on the laser beam degradation will be investigated in a laboratory experimental approach with a mid-IR laser beam traversing a transonic free air stream relevant to a real air flow around a fuselage. The propagation characteristics of a laser beam passing turbulent air will be numerically simulated with a multiple phase-screen method and a Fourier propagation technique. Different turbulence degrees relevant to propagation directions especially behind aircrafts will be considered.

  6. Loop laser cavities with self-pumped phase-conjugate mirrors in low-gain active media for phase-locked multichannel laser systems

    SciTech Connect

    Basiev, Tasoltan T; Gavrilov, A V; Ershkov, M N; Smetanin, Sergei N; Fedin, Aleksandr V; Bel'kov, K A; Boreysho, A S; Lebedev, V F

    2011-03-31

    It is proved that lasers with different loop cavities with self-pumped phase-conjugate mirrors in low-gain active media can operate under injection of external laser radiation and can be used for the development of diode-pumped phase-locked multichannel neodymium laser systems operating both on the fundamental laser transition with the wavelength {lambda} = 1.06 {mu}m and on the transition with {lambda} = 1.34 {mu}m. The phase-conjugate oscillation thresholds in the case of injection of an external signal are determined for a multiloop cavity configuration and an increased number of active elements in the cavity. It is shown that phase-conjugate oscillation can occur even if the single-pass gain of the active element is as low as only {approx}2. Under high-power side diode pumping of a multiloop Nd:YAG laser, single-mode output radiation was achieved at {lambda} = 1.064 {mu}m with a pulse energy up to 0.75 J, a pulse repetition rate up to 25 Hz, an average power up to 18.3 W, and an efficiency up to 20%. In a multiloop Nd:YAG laser with three active elements in the cavity, single-mode radiation at {lambda} = 1.34 {mu}m was obtained with a pulse energy up to 0.96 J, a pulse repetition rate up to 10 Hz, and an average power up to 8.5 W. (control of laser radiation parameters)

  7. Recycle Rate in a Pulsed, Optically Pumped Rubidium Laser

    SciTech Connect

    Miller, Wooddy S.; Sulham, Clifford V.; Holtgrave, Jeremy C.; Perram, Glen P.

    2010-10-08

    A pulsed, optically pumped rubidium laser operating in analogy to the diode pumped alkali laser (DPAL) system at pump intensities as high as 750 kW/cm{sup 2} has been demonstrated with output energies of up to 13 {mu}J/pulse. Output energy is dramatically limited by spin-orbit relaxation rates under these high intensity pump conditions. More than 250 photons are available for every rubidium atom in the pumped volume, requiring a high number of cycles per atom during the 2-8 ns duration of the pump pulse. At 550 Torr of ethane, the spin-orbit relaxation rate is too slow to effectively utilize all the incident pump photons. Indeed, a linear dependence of output energy on pump pulse duration for fixed pump energy is demonstrated.

  8. Photovoltaic pump systems

    NASA Astrophysics Data System (ADS)

    Klockgether, J.; Kiessling, K. P.

    1983-09-01

    Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

  9. Theoretical studies of solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, Wynford L.

    1990-01-01

    One concept for collecting solar energy is to use large solar collectors and then use lasers as energy converters whose output beams act as transmission lines to deliver the energy to a destination. The efficiency of the process would be improved if the conversion could be done directly using solar pumped lasers, and the possibility of making such lasers is studied. There are many applications for such lasers, and these are examined. By including the applications first, the requirements for the lasers will be more evident. They are especially applicable to the Space program, and include cases where no other methods of delivering power seem possible. Using the lasers for conveying information and surveillance is also discussed. Many difficulties confront the designer of an efficient system for power conversion. These involve the nature of the solar spectrum, the method of absorbing the energy, the transfer of power into laser beams, and finally, the far field patterns of the beams. The requirements of the lasers are discussed. Specific laser configurations are discussed. The thrust is into gas laser systems, because for space applications, the laser could be large, and also the medium would be uniform and not subject to thermal stresses. Dye and solid lasers are treated briefly. For gas lasers, a chart of the various possibilities is shown, and the various families of gas lasers divided according to the mechanisms of absorbing solar radiation and of lasing. Several specific models are analyzed and evaluated. Overall conclusions for the program are summarized, and the performances of the lasers related to the requirements of various applications.

  10. "Diode Pumped Solid State Lasers At 2 And 3 µm"

    NASA Astrophysics Data System (ADS)

    Esterowitz, Leon

    1988-06-01

    The most attractive alternative to flashlamp pumping of solid state lasers is the diode laser. In the past two decades numerous laboratory devices have been assembled which incorporated single diode lasers, small laser diode arrays or LED's for pumping of Nd:YAG, Nd:glass and a host of other Nd lasers. The low power output, low packaging density, and extremely high cost of diode lasers prevented any serious applications for laser pumping in the past. The reason for the continued interest in this area stems from the potential dramatic increase in system efficiency and component lifetime, and reduction of thermal load of the solid-state laser material. The latter not only will reduce thereto-optic effects and therefore lead to better beam quality but also will enable an increase in pulse repetition frequency. The attractive operating parameters combined with low voltage operation and the compactness of an all solid-state laser system have a potential high payoff. The high pumping efficiency compared to flashlamps stems from the good spectral match between the laser diode emission and the rare earth activator absorption bands. A significant advantage of laser diode pumping compared to arc lamps is system lifetime and reliability. Laser diode arrays have exhibited lifetimes on the order of 10,000 hours in cw operation and 109 shots in the pulsed mode. Flashlamp life is on the order of 107 shots, and about 200 hours for cw operation. In addition, the high pump flux combined with a substantial UV content in lamp pumped systems causes material degradation in the pump cavity and in the coolant. Such problems are virtually eliminated with laser diode pump sources. The absence of high voltage pulses, high temperatures and UV radiation encountered with arc lamps leads to much more benign operating features for solid state laser systems employing laser diode pumps. Laser diode technology dates back to 1962 when laser action in GaAs diodes was first demonstrated. However, it

  11. Lasers from fission. [nuclear pumping feasibility experiments

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.; Thom, K.; Helmick, H. H.

    1975-01-01

    The feasibility of the nuclear pumping of lasers was demonstrated in three experiments conducted independently at three different laboratories. In this context nuclear pumping of lasers is understood to be the excitation of a laser by the kinetic energy of the fission fragments only. A description is given of research concerned with the use of nuclear energy for the excitation of gas lasers. Experimental work was supplemented by theoretical research. Attention is given to a nuclear pumped He-Xe laser, a nuclear pumped CO laser, and a neon-nitrogen laser pumped by alpha particles. Studies involving uranium hexafluoride admixture to laser media are discussed along with research on uranium hexafluoride-fueled reactors.

  12. Lasers from fission. [nuclear pumping feasibility experiments

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.; Thom, K.; Helmick, H. H.

    1975-01-01

    The feasibility of the nuclear pumping of lasers was demonstrated in three experiments conducted independently at three different laboratories. In this context nuclear pumping of lasers is understood to be the excitation of a laser by the kinetic energy of the fission fragments only. A description is given of research concerned with the use of nuclear energy for the excitation of gas lasers. Experimental work was supplemented by theoretical research. Attention is given to a nuclear pumped He-Xe laser, a nuclear pumped CO laser, and a neon-nitrogen laser pumped by alpha particles. Studies involving uranium hexafluoride admixture to laser media are discussed along with research on uranium hexafluoride-fueled reactors.

  13. Energy saving pump and pumping system

    SciTech Connect

    Chang, K.C.

    1983-08-02

    A centrifugal pump and a pumping system are disclosed that recover hydraulic energy in response to flow capacity reduction and spontaneously provide a recirculating flow at low capacities when pump cooling is needed. From a upstream source the fluid is guided by two suction lines to two parallel pumping mechanisms housed by a common discharge casing. Said pumping mechanisms have a combined hydraulic characteristic that the first pumping mechanism will force a reverse flow through the second pumping mechanism, when pump discharge is reduced by the system below a certain low flow rate. The reverse flow will then return to the upstream fluid source through a suction line. The pump is the protected from overheating by a circulating flow at low flow capacities. At the same time, said reverse flow generates a turbine action on the second pumping mechanism and transmits the contained hydraulic energy back to the rotor and thereby results in power saving at low flow capacities.

  14. Solar-pumped gas laser development

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1980-01-01

    A survey of gas properties through detailed kinetic models led to the identification of critical gas parameters for use in choosing appropriate gas combinations for solar pumped lasers. Broadband photoabsorption in the visible or near UV range is required to excite large volumes of gas and to insure good solar absorption efficiency. The photoexcitation density is independent of the absorption bandwidth. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than 10 A to insure lasing threshold over reasonable gain lengths. The system should show a high degree of chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. Although photoexcitation of electronic vibrational transitions is considered as a possible system if the emission bands sufficiently narrow, it appears that photodissociation into atomic metastables is more likely to result in a successful solar pumped laser system.

  15. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, K. S.

    1986-01-01

    During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing the parametric studies. In addition, the kinetic modeling of a solar-pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) a 10 W CW iodine laser pumped by a Vortek solar simulator; (2) kinetic modeling to predict the time to lasing threshold, lasing time, and energy output of solar-pumped iodine laser; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

  16. Laser diode array pumped continuous wave Rubidium vapor laser.

    PubMed

    Zhdanov, B V; Stooke, A; Boyadjian, G; Voci, A; Knize, R J

    2008-01-21

    We have demonstrated continuous wave operation of a laser diode array pumped Rb laser with an output power of 8 Watts. A slope efficiency of 60% and a total optical efficiency of 45% were obtained with a pump power of 18 Watts. This laser can be scaled to higher powers by using multiple laser diode arrays or stacks of arrays.

  17. Rubidium vapor laser pumped by two laser diode arrays.

    PubMed

    Zhdanov, Boris V; Stooke, Adam; Boyadjian, Gregory; Voci, Adam; Knize, R J

    2008-03-01

    Scaling of alkali lasers to higher powers requires using multiple diode lasers for pumping. The first (to our knowledge) results of a cw rubidium laser pumped by two laser diode arrays are presented. A slope efficiency of 53%, total optical efficiency of 46%, and output power of 17 W have been demonstrated.

  18. Identification and properties of molecular systems of potential use in solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Micha, D. A.; Oehrn, N. Y.

    1985-01-01

    The concepts and computational tools of theortical chemistry are used to investigate molecular properties needed in direct solar-pumped lasers. Compounds of the type RR'CXY, with R and R' organic groups, and X and Y halide atoms were identified as likely candidates because of their highly enhanced absorption coefficients over compounds with a single halide atom. The use of a combination of vibrational excitation followed by electronic excitation to enhance quantum yields at certain wavelengths is indicated. A self-consistent eikonal approximation to state-to-state transitions was tested for CH3I and is useful for other problems involving electronic energy and charge transfer. An approach to calculate potential energy surfaces and transition dipoles was developed which is based on the generation of eigenstates of the nonrelativisitc Hamiltonian followed by incorporation of the spin-orbit coupling by configuration interaction.

  19. Semiconductor Laser Diode Pumps for Inertial Fusion Energy Lasers

    SciTech Connect

    Deri, R J

    2011-01-03

    Solid-state lasers have been demonstrated as attractive drivers for inertial confinement fusion on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) and at the Omega Facility at the Laboratory for Laser Energetics (LLE) in Rochester, NY. For power plant applications, these lasers must be pumped by semiconductor diode lasers to achieve the required laser system efficiency, repetition rate, and lifetime. Inertial fusion energy (IFE) power plants will require approximately 40-to-80 GW of peak pump power, and must operate efficiently and with high system availability for decades. These considerations lead to requirements on the efficiency, price, and production capacity of the semiconductor pump sources. This document provides a brief summary of these requirements, and how they can be met by a natural evolution of the current semiconductor laser industry. The detailed technical requirements described in this document flow down from a laser ampl9ifier design described elsewhere. In brief, laser amplifiers comprising multiple Nd:glass gain slabs are face-pumped by two planar diode arrays, each delivering 30 to 40 MW of peak power at 872 nm during a {approx} 200 {micro}s quasi-CW (QCW) pulse with a repetition rate in the range of 10 to 20 Hz. The baseline design of the diode array employs a 2D mosaic of submodules to facilitate manufacturing. As a baseline, they envision that each submodule is an array of vertically stacked, 1 cm wide, edge-emitting diode bars, an industry standard form factor. These stacks are mounted on a common backplane providing cooling and current drive. Stacks are conductively cooled to the backplane, to minimize both diode package cost and the number of fluid interconnects for improved reliability. While the baseline assessment in this document is based on edge-emitting devices, the amplifier design does not preclude future use of surface emitting diodes, which may offer appreciable future cost reductions and

  20. Terahertz graphene lasers: Injection versus optical pumping

    SciTech Connect

    Ryzhii, Victor; Otsuji, Taiichi; Ryzhii, Maxim; Mitin, Vladimir

    2013-12-04

    We analyze the formation of nonequilibrium states in optically pumped graphene layers and in forward-biased graphene structures with lateral p-i-n junctions and consider the conditions of population inversion and lasing. The model used accounts for intraband and interband relaxation processes as well as deviation of the optical phonon system from equilibrium. As shown, optical pumping suffers from a significant heating of both the electron-hole plasma and the optical phonon system, which can suppress the formation of population inversion. In the graphene structures with p-i-n junction, the injected electrons and holes have relatively low energies, so that the effect of cooling can be rather pronounced, providing a significant advantage of the injection pumping in realization of graphene terahertz lasers.

  1. Heat pump systems

    SciTech Connect

    Sauer, H.J.; Howell, R.H.

    1983-01-01

    This book was written as a reference and textbook on heat pumps. Economics, thermodynamics, heat transfer, design, selection, and operating practices are covered in detail. Specific methods, and solutions rather than broad generalizations are emphasized. Includes problems, bibliographies, and a subject index. For applied science collections in public, college and appropriate special libraries. Contents: Thermodynamics, Heat pump systems and applications. Heat pump components. Heating and cooling loads. Energy use determination. Reliability, maintenance, and service. Advances in heat pumps. Appendices. Index.

  2. Demonstration of a free-space optical communication system using a solar-pumped laser as signal transmitter

    NASA Astrophysics Data System (ADS)

    Guan, Z.; Zhao, C. M.; Yang, S. H.; Wang, Y.; Ke, J. Y.; Zhang, H. Y.

    2017-05-01

    A free-space optical communication system with a sun light directly pumped laser as the signal transmitter was demonstrated. A 0.6  ×  0.6 m Fresnel lens was used as the primary concentrator to collect the solar light. 6.8 W continuous wave laser power was obtained from a 4 mm diameter grooved Nd:YAG rod. The output intensity was modulated with a video signal via a LiNbO3 Mach-Zehnder optoelectronic modulator. The video signal with a resolution of 1920  *  1080/frame and the frame rate of 25 Hz was transmitted over five-meter free-space in real time with high fidelity. The transmission rate was 125 Mbps and bit error rate was lower than 10-6. This research shows the feasibility of applying a solar light directly pumped laser for free-space optical communication, which is significant for telecommunications between satellites.

  3. Portable Diode Pumped Femtosecond Lasers

    DTIC Science & Technology

    2007-03-01

    Troshin, V. G. Shcherbitsky, N. V. Kuleshov, V. N. Matrosov , T. A. Matrosava, M. I. Kupchenko, F. Brunner, R. Paschotta, F. Morier-Genoud, and U. Keller...Tolstik, V. G. Shcherbitsky, N. V. Kuleshov, V. N. Matrosov , T. A. Matrosava, and M. I. Kupchenko. “Spectroscopy and continuous-wave diode-pumped laser...Denisov, A. E. Troshin, K. V. Yumashev, N. V. Kuleshov, V. N. Matrosov , T. A. Matrosova, and M. I. Kupchenko. “Yb3+-doped YVO4 crystal for efficient

  4. An investigation of a mathematical model of an optically pumped Ti(3+):Al2O3 laser system

    NASA Technical Reports Server (NTRS)

    Roberts, Lila F.

    1989-01-01

    During the last several years, solid state lasers were developed that have the potential for meeting rigorous performance requirements for space-based remote sensing of the atmosphere. In order to design a stable and efficient laser and to understand the effect on laser output of changes in the physical and design parameters, an understanding of the development of the dynamical processes of the laser is necessary. Typically, the dynamical processes in a laser system are investigated via rate equations describing the evolution of the occupancy in the electronic levels and of the photon density in the laser cavity. There are two approaches to this type of study. Most often, for the sake of simplicity, the spatial variations of the dynamic variables in the laser system are disregarded and the mathematical model consists of a system of first order nonlinear ordinary differential equations (ODE). The second approach is to take into account both spatial and temporal variations in the dynamic variables in the laser cavity. The resulting model consists of a first order semilinear system of partial differential equations (PDE). The model which was studied was studied was generic in the sense that it was a four-level laser system, but the parameters used in the numerical study were specific to Titanium-doped sapphire. For simplicity, a constant, spatially uniform pumping scheme was considered. In addition, a simplification of the model was made so that it treats a single lasing wavelength with a narrow bandwidth. The purpose was to investigate both versions of the mathematical model and to determine whether the numerical solutions are similar both qualitatively and quantitatively. The systems of ordinary differential equations were solved numerically using a Runge-Kutta-Fehlberg algorithm which was very efficient for typical values of the physical parameters. A numerical scheme, based on the Modified Euler method, for computing solutions to the system of partial differential

  5. Ho:YLF pumped HBr laser.

    PubMed

    Botha, L R; Bollig, C; Esser, M J D; Campbell, R N; Jacobs, C; Preussler, D R

    2009-10-26

    A Ho:YLF laser pumped HBr molecular laser was developed that produced up to 2.5 mJ of energy in the 4 micron wavelength region. The Ho:YLF laser was fiber pumped using a commercial Tm:fibre laser. The Ho:YLF laser was operated in a single longitudinal mode via injection seeding with a narrow band diode laser which in turn was locked to one of the HBr transitions. The behavior of the HBr laser was described using a rate equation mathematical model and this was solved numerically. Good agreement both qualitatively and quantitatively between the model and experimental results was obtained.

  6. Optically pumped Cs vapor lasers: pump-to-laser beam overlap optimization

    NASA Astrophysics Data System (ADS)

    Auslender, Ilya; Cohen, Tom; Lebiush, Eyal; Barmashenko, Boris D.; Rosenwaks, Salman

    2017-01-01

    We present the results of an experimental study of Ti:Sapphire pumped Cs laser and theoretical modeling of these results, where we focused on the influence of the pump-to-laser beam overlap, a crucial parameter for optimizing the output laser power. The dependence of the output laser power on the incident pump power was found for varying pump beam cross-section widths and for a constant laser beam. Maximum laser power > 370 mW with an optical-to-optical efficiency of 43% and slope efficiency 55% was obtained. Non monotonic dependence of the laser power and threshold power on the pump beam radius (at a given pump power) was observed with a maximum laser power and minimum threshold power achieved at the ratio 0.7 between the optimal pump beam and laser beam radius. A simple optical model of the laser, where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams were assumed, was compared to the experiments. Good agreement was obtained between the measured and calculated dependence of the laser power on the incident pump power at different pump beam radii and of the laser power, threshold power and optimal temperature on the pump beam radius. The model does not use empirical parameters such as mode overlap efficiency but rather the pump and laser beam spatial shapes as input parameters. This model can be applied to different optically pumped alkali lasers with arbitrary spatial distributions of the pump and laser beam widths.

  7. Pump light distribution in a laser rod pumped exfocally in a rotational ellipsoid.

    PubMed

    Mahlein, H F; Zeidler, G

    1971-04-01

    In a rotational ellipsoidal exfocal pumping system the linear lamp is arranged between vertex and nearest focus, and the laser rod is aligned between the second focus and the other vertex along the major axis of a rotational ellipsoidal mirror. For this optical pumping system, a calculation of the pump light distribution in the laser rod was performed on a computer by use of a ray tracing procedure. The calculations take account of reflection losses, multiple reflections, and shadowing at the end faces of the laser rod and the lamp. A series of diagrams presents the results of the computer calculations, which are also compared with experimental results.

  8. Compact 36 kJ electron beam system for laser pumping

    NASA Astrophysics Data System (ADS)

    Schlitt, L. G.

    1981-05-01

    An electron beam machine consisting of six modules is being constructed for the B amplifier of a KrF laser system. Each module consists of a diode, a 5 omega positive charged water dielectric Blumlein pulse forming line, and a five stage Marx generator. Separate 25 cm by 41 cm electron beams are formed in magnetically isolated diodes which when arranged in groups of three produce two nearly continuous 25 cm by 125 cm beams that enter the laser cell from opposite sides. The pulse forming lines operate at 450 keV and Produce 150 ns long pulses. The lines employ electrically triggered annular SF6 output switches. The two concentric transmission lines of each pulse forming line are charged in 1 microsec through symmetric circuits to reduce diode prepulse voltage. The six modules together with the laser cell occupy less than 15 sq m of floor space.

  9. High-power cw operation of diode laser transversely-pumped Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Golla, Dirk; Knoke, S.; Schoene, Wolfram; Ernst, G.; Tuennermann, Andreas; Welling, Herbert

    1995-04-01

    We report on diode laser side-pumped, cw Nd:YAG rod lasers operating at pump powers up to 1 kW. With linear diode laser arrays as pump sources a pump power of 90 W/cm is realized. In multimode operation at 1064 nm, output powers of more than 300 W cw are observed. Applying a dynamically stable resonator design, an output power of more than 45 W in TEM00 mode operation is realized with an optical-to-optical efficiency of more than 11%. Higher pump powers up to several 100 W/cm can be achieved by using fiber-coupled diode lasers as pump sources. Laser performance, thermal properties and possible applications of these laser systems will be discussed.

  10. NDT of fiber-reinforced composites with a new fiber-optic pump-probe laser-ultrasound system.

    PubMed

    Pelivanov, Ivan; Buma, Takashi; Xia, Jinjun; Wei, Chen-Wei; O'Donnell, Matthew

    2014-06-01

    Laser-ultrasonics is an attractive and powerful tool for the non-destructive testing and evaluation (NDT&E) of composite materials. Current systems for non-contact detection of ultrasound have relatively low sensitivity compared to contact peizotransducers. They are also expensive, difficult to adjust, and strongly influenced by environmental noise. Moreover, laser-ultrasound (LU) systems typically launch only about 50 firings per second, much slower than the kHz level pulse repetition rate of conventional systems. As demonstrated here, most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive, high repetition rate nanosecond fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe beam detector. In particular, a modified fiber-optic balanced Sagnac interferometer is presented as part of a LU pump-probe system for NDT&E of aircraft composites. The performance of the all-optical system is demonstrated for a number of composite samples with different types and locations of inclusions.

  11. Cladding For Transversely-Pumped Laser Rod

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  12. Cladding For Transversely-Pumped Laser Rod

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  13. Feasibility of solar-pumped dye lasers

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    Dye laser gains were measured at various pump-beam irradiances on a dye cell in order to evaluate the feasibility of solar pumping. Rhodamine 6G dye was considered as a candidate for the solar-pumped laser because of its high utilization of the solar spectrum and high quantum efficiency. Measurements show that a solar concentration of 20,000 is required to reach the threshold of the dye.

  14. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Hwang, In Heon

    1990-01-01

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

  15. High average power, diode pumped petawatt laser systems: a new generation of lasers enabling precision science and commercial applications

    NASA Astrophysics Data System (ADS)

    Haefner, C. L.; Bayramian, A.; Betts, S.; Bopp, R.; Buck, S.; Cupal, J.; Drouin, M.; Erlandson, A.; Horáček, J.; Horner, J.; Jarboe, J.; Kasl, K.; Kim, D.; Koh, E.; Koubíková, L.; Maranville, W.; Marshall, C.; Mason, D.; Menapace, J.; Miller, P.; Mazurek, P.; Naylon, A.; Novák, J.; Peceli, D.; Rosso, P.; Schaffers, K.; Sistrunk, E.; Smith, D.; Spinka, T.; Stanley, J.; Steele, R.; Stolz, C.; Suratwala, T.; Telford, S.; Thoma, J.; VanBlarcom, D.; Weiss, J.; Wegner, P.

    2017-05-01

    Large laser systems that deliver optical pulses with peak powers exceeding one Petawatt (PW) have been constructed at dozens of research facilities worldwide and have fostered research in High-Energy-Density (HED) Science, High-Field and nonlinear physics [1]. Furthermore, the high intensities exceeding 1018W/cm2 allow for efficiently driving secondary sources that inherit some of the properties of the laser pulse, e.g. pulse duration, spatial and/or divergence characteristics. In the intervening decades since that first PW laser, single-shot proof-of-principle experiments have been successful in demonstrating new high-intensity laser-matter interactions and subsequent secondary particle and photon sources. These secondary sources include generation and acceleration of charged-particle (electron, proton, ion) and neutron beams, and x-ray and gamma-ray sources, generation of radioisotopes for positron emission tomography (PET), targeted cancer therapy, medical imaging, and the transmutation of radioactive waste [2, 3]. Each of these promising applications requires lasers with peak power of hundreds of terawatt (TW) to petawatt (PW) and with average power of tens to hundreds of kW to achieve the required secondary source flux.

  16. Diode pumped alkali vapor fiber laser

    DOEpatents

    Payne, Stephen A.; Beach, Raymond J.; Dawson, Jay W.; Krupke, William F.

    2007-10-23

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  17. Diode pumped alkali vapor fiber laser

    DOEpatents

    Payne, Stephen A.; Beach, Raymond J.; Dawson, Jay W.; Krupke, William F.

    2006-07-26

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  18. Solar-pumped solid-state lasers

    SciTech Connect

    Weksler, M.; Shwartz, J.

    1988-06-01

    Results are presented for direct solar pumping of a ND:YAG rod laser. Stable CW output of more than 60 W was obtained with a slope efficiency exceeding 2 percent. A compound parabolic concentrator, designed to increase the solar radiation coupled into the laser rod, was used in these experiments. The results are consistent with predictions based on a simple solar-pumped laser model, which is also presented. Using this model, it is shown that existing laser materials with broad-band absorption characteristics (e.g., alexandrite and Nd:Cr:GSGG) have a potential for better than 10 percent overall conversion efficiency when solar pumped.

  19. Centrifugal pump fuel system

    SciTech Connect

    McGlone, M.E.; Larkins, L.J.; Johnson, R.O.; Moeller, K.A.

    1993-06-22

    A centrifugal pump fuel system for an engine driven fuel pump for an aircraft gas turbine engine is described comprising: a centrifugal pump having at constant speed rising head/flow characteristic at low flows; a plumbing system receiving flow from the pump, and having at least one control valve located down stream of and defining a discrete volume of the plumbing system; a plumbing resonant frequency defined by the discrete volume, the geometry of the plumbing system, and the bulk modulus of the fuel; a pressure difference regulating valve located adjacent to the discharge of the pump, up stream of the vast majority of the discrete volume; and the frequency response of the regulating valve being significantly less than the frequency response of the plumbing system such that the response of the regulating valve is attenuated at the resonant frequency of the plumbing system.

  20. Assignment of the /Li-7/2 optically pumped laser transitions pumped by Ar/+/ and Kr/+/ laser lines

    NASA Technical Reports Server (NTRS)

    Verma, K. K.; Stwalley, W. C.; Zemke, W. T.

    1981-01-01

    Welling and Wellegehausen (1977) have reported a list of Na2 and Li2 lines (belonging to B-X and A-X systems) which lase when vapors of these dimers are pumped with an Ar(+) or Kr(+) laser. A description is presented of a fluorescence study of the A-X system of the (Li-7)2 molecule excited by a Kr(+) laser (6471 A). The optically pumped laser lines are identified as P and R doublets in two different fluorescence series. The conditions which favor lasing action of these lines are pointed out. All but one of the known optically pumped laser lines of (Li-7)2 along with their assignments are presented in a table. For each pumping line, several additional wavelengths are listed which satisfy the condition for laser oscillations and which might well lase well under slightly improved conditions.

  1. Color center laser pumped with a DCM dye laser

    NASA Astrophysics Data System (ADS)

    Hills, G. W.

    1982-08-01

    A CW, DCM dye laser has been used to pump a RbCl:Li crystal in a color center laser. The DCM dye laser was pumped by the 488 nm and 514.5 nm lines of an argon ion laser. When used in a broad band configuration the dye laser had a power output in the TEM 00 mode in excess of 600 mW at a wavelength of 655 nm. An output power in excess of 10 mW at 2.73 μm was possible from the RbCl:Li crystal in a Burleigh FCL for an input power of 600 mW at 655 nm. This method of pumping for the RbCl:Li alleviates the need for both argon ion and krypton ion laser pumps for the Burleigh FCL. All three crystals can be pumped to the specification power levels with a single argon ion laser.

  2. Robust modeling and performance analysis of high-power diode side-pumped solid-state laser systems.

    PubMed

    Kashef, Tamer; Ghoniemy, Samy; Mokhtar, Ayman

    2015-12-20

    In this paper, we present an enhanced high-power extrinsic diode side-pumped solid-state laser (DPSSL) model to accurately predict the dynamic operations and pump distribution under different practical conditions. We introduce a new implementation technique for the proposed model that provides a compelling incentive for the performance assessment and enhancement of high-power diode side-pumped Nd:YAG lasers using cooperative agents and by relying on the MATLAB, GLAD, and Zemax ray tracing software packages. A large-signal laser model that includes thermal effects and a modified laser gain formulation and incorporates the geometrical pump distribution for three radially arranged arrays of laser diodes is presented. The design of a customized prototype diode side-pumped high-power laser head fabricated for the purpose of testing is discussed. A detailed comparative experimental and simulation study of the dynamic operation and the beam characteristics that are used to verify the accuracy of the proposed model for analyzing the performance of high-power DPSSLs under different conditions are discussed. The simulated and measured results of power, pump distribution, beam shape, and slope efficiency are shown under different conditions and for a specific case, where the targeted output power is 140 W, while the input pumping power is 400 W. The 95% output coupler reflectivity showed good agreement with the slope efficiency, which is approximately 35%; this assures the robustness of the proposed model to accurately predict the design parameters of practical, high-power DPSSLs.

  3. A Modular Control Platform for a Diode Pumped Alkali Laser

    NASA Astrophysics Data System (ADS)

    Shapiro, J.; Teare, S.

    Many of the difficulties of creating compact, high power laser systems can be overcome if the heat dissipating properties of chemical lasers can be combined with the efficiency of diode lasers. Recently, the novel idea of using solid state diode lasers to pump gaseous gain media, such as is done in diode pumped alkali lasers (DPALs), has been proposed and early experiments have shown promising results. However, a number of technical issues need to be overcome to realize high output power from these lasers. In order to achieve higher power, the efficiency of coupling between pump laser energy and the chemical cell must be increased, and eventually multiple high power diode pumps must be combined and synchronized so that their energy can pump the chemical cell. Additionally, an inter-cavity adaptive optics system may be a requirement to be able to propagate these lasers with high efficiency. DPAL systems are complex and require a significant amount of data fusion and active feedback to control and optimize their performance. There are a wide range of components including pump lasers, gain cells and monitoring points needed to study and refine the overall laser system. In support of this dynamic development environment, we have developed a hardware framework using commercial off the shelf (COTS) components which supports the rapid assembly of functional system blocks into a cohesive integrated system. Critical to this system are a simple communication protocol, industry standard communication pipes (USB, Bluetooth, etc), and flexible high level scripting. Simplifying the integration process has the benefit of allowing flexible "on the fly" modifications to adapt the system as needed and enhance available functionality. The modular nature of the architecture allows scalability and adaptability as more pieces are added to the system. Key components of this system are demonstrated for selected portions of a DPAL system using a USB backbone.

  4. Grazing Incidence Pumping for High Efficiency X-ray Lasers

    SciTech Connect

    Dunn, J; Keenan, R; Shlyaptsev, V N

    2005-10-03

    Over the last decade, most laser-driven collisional excitation x-ray lasers have relied on the absorption of the pump energy incident at normal incidence to a pre-formed plasma. The main advantage is that the inversion can be created at various plasma regions in space and time where the amplification and ray propagation processes are best served. The main disadvantage is that different plasma regions regardless of the contribution to the inversion have to be pumped simultaneously in order to make the laser work. This leads to a loss of efficiency. The new scheme of grazing incidence pumping (GRIP) addresses this issue. In essence, a chosen electron density region of a pre-formed plasma column, produced by a longer pulse at normal incidence onto a slab target, is selectively pumped by focusing a short pulse of 100 fs-10 ps duration laser at a determined grazing incidence angle to the target surface. The exact angle is dependent on the pump wavelength and relates to refraction of the drive beam in the plasma. The controlled use of refraction of the pumping laser in the plasma results in several benefits: The pump laser path length is longer and there is an increase in the laser absorption in the gain region for creating a collisional Ni-like ion x-ray laser. There is also an inherent traveling wave, close to c, that increases the overall pumping efficiency. This can lead to a 3-30 times reduction in the pump energy for mid-Z, sub-20 nm lasers. We report several examples of this new x-ray laser on two different laser systems. The first demonstrates a 10 Hz x-ray laser operating at 18.9 nm pumped with a total of 150 mJ of 800 nm wavelength from a Ti:Sapphire laser. The second case is shown where the COMET laser is used both at 527 nm and 1054 nm wavelength to pump higher Z materials with the goal of extending the wavelength regime of tabletop x-ray lasers below 10 nm.

  5. Diode-side-pumped Alexandrite slab lasers.

    PubMed

    Damzen, M J; Thomas, G M; Minassian, A

    2017-05-15

    We present the investigation of diode-side-pumping of Alexandrite slab lasers in a range of designs using linear cavity and grazing-incidence bounce cavity configurations. An Alexandrite slab laser cavity with double-pass side pumping produces 23.4 mJ free-running energy at 100 Hz rate with slope efficiency ~40% with respect to absorbed pump energy. In a slab laser with single-bounce geometry output power of 12.2 W is produced, and in a double-bounce configuration 6.5 W multimode and 4.5 W output in TEM00 mode is produced. These first results of slab laser and amplifier designs in this paper highlight some of the potential strategies for power and energy scaling of Alexandrite using diode-side-pumped Alexandrite slab architectures with future availability of higher power red diode pumping.

  6. Solar-pumped gas laser development

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1981-01-01

    The direct conversion of solar radiation into an inverted population for extraction in an optical cavity holds promise as a relatively simple system design. Broad-band photoabsorption in the visible or near-UV range is required to excite large volumes of gas and to ensure good solar absorption efficiency. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than approximately 10 A. The system should show chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. A search of electronic-vibrational transitions in diatomic molecules satisfying these conditions is now in progress. A photodissociation-pumped atomic iodine laser is now being tested under solar pumping conditions. Photodissociation studies for thallium spin-flip metastable formation will begin in the near future.

  7. A Theoretical Model Analysis of Absorption of a Three level Diode Pumped Alkali Laser

    DTIC Science & Technology

    2009-03-01

    A THEORETICAL MODEL ANALYSIS OF ABSORPTION OF A THREE LEVEL DIODE PUMPED ALKALI LASER ...States Government. AFIT/GAP/ENP/09-M07 A THEORETICAL MODEL ANALYSIS OF ABSORPTION OF A THREE LEVEL DIODE PUMPED ALKALI LASER THESIS...This paper models the absorption phenomena of light in a three level diode pumped alkali laser system. Specifically this model calculates for a user

  8. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.

    1987-01-01

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

  9. Overview and future direction for blackbody solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.

    1988-01-01

    A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

  10. Diode laser-pumped solid-state lasers

    NASA Technical Reports Server (NTRS)

    Fan, Tso Yee; Byer, Robert L.

    1988-01-01

    Recently, interest in diode laser-pumped solid-state lasers has increased due to their advantages over flashlamp-pumped solid-state lasers. A historical overview is presented of semiconductor diode-pumped solid-state lasers beginning with work in the early 1960s and continuing through recent work on wavelength extension of these devices by laser operation on new transitions. Modeling of these devices by rate equations to obtain expressions for threshold, slope efficiency, and figures of merit is also given.

  11. Picosecond Raman Spectroscopy: A Two Dye Laser Synchronously Pumped Raman System

    NASA Astrophysics Data System (ADS)

    Chung, Y. C.; Hopkins, J. B.; Rentzepis, P. M.

    1986-11-01

    Raman spectroscopy is a mature field of science that does not need introduction nor rationalization for its use. The majority of the Raman spectroscopy literature is concerned with C.W. high resolution spectroscopy. The Raman Scattering instruments utilize almost exclusively laser light sources, and lately nanosecond and picosecond data on time resolved spectra have made their entrance into the scientific journals. The difficulty in most of these resonance Raman experiments is that they do not provide any more time dependent information than fluorescence. This is due to the limitation that a single laser, quite often, a dye laser and its second harmonic are the only two frequencies available for excitation and resonance probe of the excited state. In this scenario, a Raman Scattering signal is emitted and detected only during the lifetime of the excited state. As the excited state decays to either the ground state or other transient species which absorb at a different wavelength, the resonance with the probe wavelength disappears at the same rate as the population of the excited state decays. This rate of depopulation is also portrayed in an identical fashion. These systems are therefore drastically limited in their use as means for the measurement of the evolution of a chemical intermediate. An additional interesting aspect is that of the understanding of the process itself which is being studied, namely the majority of the research papers presented do not address the possibility of the data depicting stimulated emission gain rather than Raman Scattering.

  12. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  13. Absorption heat pump system

    DOEpatents

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  14. Optically Pumped Carbon Monoxide Cascade Laser

    DTIC Science & Technology

    2005-07-01

    absorption problems it poses. Instead, a 2.3 gtm GaSb diode laser could be used as a 1st overtone optically pumped source. The absorption cross section at...OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER BY NICHOLAS W. SAWRUK B.S., PHYSICS, US AIR FORCE ACADEMY, 2001 B.S., MATHEMATICS, US AIR FORCE...SUBTITLE 5. FUNDING NUMBERS OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER 6. AUTHOR(S) 1ST LT SAWRUK NICHOLAS W 7. PERFORMING ORGANIZATION NAME(S) AND

  15. Optically Pumped Carbon Monoxide Cascade Laser

    DTIC Science & Technology

    2005-06-30

    bother with the small absorption cross-sections of 2nd overtone pumping and the absorption problems it poses. Instead, a 2.3 µm GaSb diode laser ...could be used as a 1 st overtone optically pumped source. The absorption cross section at 2.3 µm is over 100 times larger. The 2.3 µm diode laser is...AFRL-DE-PS- AFRL-DE-PS- TR-2005-1093 TR-2005-1093 OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER NICHOLAS W. SAWRUK 30 June 2005 Final Report

  16. Exploding conducting film laser pumping apparatus

    DOEpatents

    Ware, Kenneth D.; Jones, Claude R.

    1986-01-01

    Exploding conducting film laser optical pumping apparatus. The 342-nm molecular iodine and the 1.315-.mu.m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

  17. Intelligent pumping system developed

    SciTech Connect

    Not Available

    1983-06-01

    The oil field's first intelligent rod pumping system designed specifically to reduce the cost of pumping oil wells now is a reality. As a plus benefit, the system (called Liftronic) is compact and quiet. The new system combines an efficient mechanical design with a computer control system to reduce pumping costs. The unit stands less than 8 ft high, or approx. one-fourth the height of a comparable beam unit. It also mounts directly on the wellhead. The entire system can be concealed behind a fence or enclosed within a small building to make it a more attractive neighbor in residential, commercial, or recreational areas. It is useful also for agricultural areas where overhead irrigation systems restrict the use of many oil field pumping systems.

  18. Continuous wave Cs diode pumped alkali laser pumped by single emitter narrowband laser diode.

    PubMed

    Zhdanov, B V; Venus, G; Smirnov, V; Glebov, L; Knize, R J

    2015-08-01

    This paper presents results of cooperative efforts on development of a continuous wave Cs diode pumped alkali laser with moderate output power, which can be considered as a prototype of the commercial device. The developed system operates at 895 nm with output power about 4 W and slope efficiency 28%. Measured turn on time of this system from the standby mode is about a minute.

  19. Plasma formation in diode pumped alkali lasers sustained in Cs

    NASA Astrophysics Data System (ADS)

    Markosyan, Aram H.; Kushner, Mark J.

    2016-11-01

    In diode pumped alkali lasers (DPALs), lasing action occurs on the resonant lines of alkali atoms following pumping by broadband semiconductor lasers. The goal is to convert the efficient but usually poor optical quality of inexpensive diode lasers into the high optical quality of atomic vapor lasers. Resonant excitation of alkali vapor leads to plasma formation through the excitation transfer from the 2P states to upper lying states, which then are photoionized by the pump and intracavity radiation. A first principles global model was developed to investigate the operation of the He/Cs DPAL system and the consequences of plasma formation on the efficiency of the laser. Over a range of pump powers, cell temperatures, excitation frequency, and mole fraction of the collision mixing agent (N2 or C2H6), we found that sufficient plasma formation can occur that the Cs vapor is depleted. Although N2 is not a favored collisional mixing agent due to large rates of quenching of the 2P states, we found a range of pump parameters where laser oscillation may occur. The poor performance of N2 buffered systems may be explained in part by plasma formation. We found that during the operation of the DPAL system with N2 as the collisional mixing agent, plasma formation is in excess of 1014-1015 cm-3, which can degrade laser output intensity by both depletion of the neutral vapor and electron collisional mixing of the laser levels.

  20. Research on solar pumped liquid lasers

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.; Kurzweg, U. H.; Cox, J. D.; Weinstein, N. H.

    1983-01-01

    A solar pumped liquid laser that can be scaled up to high power (10Mw CW) for space applications was developed. Liquid lasers have the inherent advantage over gases in that they provide much higher lasant densities and thus high power densities. Liquids also have inherent advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13:Nd(3+):ZrC14 liquid was chosen for its high intrinsic efficiency as well as its relatively good stability against decomposition due to protic contamination. The development and testing of the laser liquid and the development of a large solar concentrator to pump the laser was emphasized. The procedure to manufacture the laser liquid must include diagnostic tests of the solvent purity (from protic contamination) at various stages in the production process.

  1. Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system

    NASA Astrophysics Data System (ADS)

    Ji, En-Cai; Liu, Qiang; Hu, Zhen-Yue; Gong, Ma-Li

    2015-10-01

    The steady-state gain distribution in cladding pumped thulium-doped fiber laser (TDFL) is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition (OFI) and always occurs in tandem TDFL-Ho:YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho:YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method. Project supported by the National Natural Science Foundation of China (Grant No. 61275146), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110066), and the Special Program of the Co-construction with Beijing Municipal Government of China (Grant No. 20121000302).

  2. AlGaAs diode pumped tunable chromium lasers

    DOEpatents

    Krupke, William F.; Payne, Stephen A.

    1992-01-01

    An all-solid-state laser system is disclosed wherein the laser is pumped in the longwave wing of the pump absorption band. By utilizing a laser material that will accept unusually high dopant concentrations without deleterious effects on the crystal lattice one is able to compensate for the decreased cross section in the wing of the absorption band, and the number of pump sources which can be used with such a material increases correspondingly. In a particular embodiment a chromium doped colquiriite-structure crystal such as Cr:LiSrAlF.sub.6 is the laser material. The invention avoids the problems associated with using AlGaInP diodes by doping the Cr:LiSrAlF.sub.6 heavily to enable efficient pumping in the longwave wing of the absorption band with more practical AlGaAs diodes.

  3. High efficiency >26 W diode end-pumped Alexandrite laser.

    PubMed

    Teppitaksak, Achaya; Minassian, Ara; Thomas, Gabrielle M; Damzen, Michael J

    2014-06-30

    We show for the first time that multi-ten Watt operation of an Alexandrite laser can be achieved with direct red diode-pumping and with high efficiency. An investigation of diode end-pumped Alexandrite rod lasers demonstrates continuous-wave output power in excess of 26W, more than an order of magnitude higher than previous diode end-pumping systems, and slope efficiency 49%, the highest reported for a diode-pumped Alexandrite laser. Wavelength tuning from 730 to 792nm is demonstrated using self-seeding feedback from an external grating. Q-switched laser operation based on polarization-switching to a lower gain axis of Alexandrite has produced ~mJ-pulse energy at 1kHz pulse rate in fundamental TEM(00) mode.

  4. 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.

  5. Excited state absorption of pump radiation as a loss mechanism in solid-state lasers

    SciTech Connect

    Kliewer, M.L.; Powell, R.C.

    1989-08-01

    The characteristics of optical pumping dynamics occurring in laser-pumped rare earth-doped, solid-state laser materials were investigated by using a tunable alexandrite laser to pump Y/sub 3/Al/sub 5/O/sub 12/:Nd/sup 3+/ in an optical cavity. It was found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump wavelengths resulting in low slope efficiencies, intense fluorescence emission is observed from the sample in the blue-green spectral region. This is attributed to the excited state absorption of pump photons which occurs during radiationless relaxation from the pump band to the metastable state. This type of process will be an important loss mechanism for monochromatic pumping of laser systems at specific pump wavelengths.

  6. Excited-state absorption of pump radiation as a loss mechanism in solid-state lasers

    SciTech Connect

    Kliewer, M.L.; Powell, R.C.

    1989-08-01

    The characteristics of optical pumping dynamics occuring in laser-pumped rare earth-doped, solid-state laser materials were investigated by using a tunable alexandrite laser to pump Y3Al5O12:Nd(3+) in an optical cavity. It was found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump wavelength resulting in low slope efficiencies, intense fluorescence emission is observed form the sample in the blue-green spectral region. This is attributed to the excited state absorption of pump photons which occurs during radiationless relaxation from the pump band to the metastable state. This type of process will be an important loss mechanism for monochromatic pumping of laser systems at specific pump wavelengths.

  7. Excited state absorption of pump radiation as a loss mechanism in solid-state lasers

    NASA Technical Reports Server (NTRS)

    Kliewer, Michael L.; Powell, Richard C.

    1989-01-01

    The characteristics of optical pumping dynamics in laser-pumped, rare-earth-doped, solid-state laser materials are investigated by using a tunable alexandrite laser to pump Y3Al5O12:Nd(3+) in an optical cavity. It is found that the slope efficiency of the Nd laser operation depends strongly on the wavelength of the pump laser. For pump wavelengths resulting in low slope efficiencies, intense fluorescence emission is observed from the sample in the blue-green spectral region. This is attributed to the excited-state absorption of pump photons which occurs during radiationless relaxation from the pump band to the metastable state. This type of process is an important loss mechanism for monochromatic pumping of laser systems at specific pump wavelengths.

  8. 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.

  9. 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.

  10. Exploding conducting film laser pumping apparatus

    DOEpatents

    Ware, K.D.; Jones, C.R.

    1984-04-27

    The 342-nm molecular iodine and the 1.315-..mu..m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

  11. Incoherently pumped continuous wave dye laser

    NASA Astrophysics Data System (ADS)

    Thiel, E.; Zander, C.; Drexhage, K. H.

    1987-05-01

    Continuous wave operation of a dye laser, pumped by an incoherent light source, is reported. A jet of a water-based solution of Rhodamine 6G is used as the laser medium in a spherical cavity with high reflectivity mirrors. Two high pressure arcs generated by electrical discharge between tungsten electrodes serve as pump source. They produce a power density of 0.5-10 kW/cm 2 in the jet causing the dye to lase at 615 nm.

  12. Laser-induced quantum pumping in graphene

    SciTech Connect

    San-Jose, Pablo; Prada, Elsa; Kohler, Sigmund; Schomerus, Henning

    2012-10-08

    We investigate non-adiabatic electron pumping in graphene generated by laser irradiation with linear polarization parallel or perpendicular to the transport direction. Transport is dominated by the spatially asymmetric excitation of electrons from evanescent into propagating modes. For a laser with parallel polarization, the pumping response exhibits a subharmonic resonant enhancement which directly probes the Fermi energy; no such enhancement occurs for perpendicular polarization. The resonance mechanism relies on the chirality of charge carriers in graphene.

  13. Multi-terrawatt, 100 fsec laser system using flashlamp-pumped, dye- converted Ti:Sapphire as an amplifier

    SciTech Connect

    White, W.E.; Reitize, D.H.; Price, D.F.; Shepherd, R.L.; Bonlie, J.D.; Hunter, J.R.; Patterson, F.G.; Perressini, D.L.

    1993-04-14

    We report on amplification of 100 fsec laser pulses to 250 mJ using flashlamp-pumped, dye converted Ti:Sapphire. The resulting 5 Hz beam is focused to irradiances in excess of 5 {times} 10{sup 18} W/cm{sup 2}.

  14. Continuous wave, 30 W Laser-Diode Bar with 10 GHz Linewidth for Rb Laser Pumping

    DTIC Science & Technology

    2008-01-01

    pumped alkali vapor ( cesium , rubidium, and potassium) lasers . Efficient operation of lower- pressure 1 atm alkali-vapor lasers requires pump sources...spectral width in cw operation for pumping of a 3.2-GHz-wide oxygen molecule transition [20]. However, the laser system had only 0.5 W/A slope...development of a volume Bragg laser (VOBLA) operating at 780 nm with 30 W cw output power. The VOBLA output power is 90% of the free-running LDB power. The

  15. Diode pumped Nd:YAG laser development

    NASA Technical Reports Server (NTRS)

    Reno, C. W.; Herzog, D. G.

    1976-01-01

    A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work.

  16. Operation of an optical in-well-pumped vertical-external-cavity surface-emitting laser

    SciTech Connect

    Zhang Wei; Ackemann, Thorsten; McGinily, Stephen; Schmid, Marc; Riis, Erling; Ferguson, Allister I

    2006-10-10

    We report the operation of an optical in-well-pumped vertical-external-cavity surface-emitting laser. The laser delivers 1 W at 855 nm and is pumped with a cost-effective fiber-coupled laser diode emitting at 806 nm. The laser modal gain is examined and ways of optimizing the system are investigated and discussed.

  17. Research on solar pumped liquid lasers

    NASA Technical Reports Server (NTRS)

    Cox, J. D.; Kurzweg, U. H.; Weinstein, N. H.; Schneider, R. T.

    1985-01-01

    A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

  18. Algorithm for evaluation of temperature distribution of a vapor cell in a diode-pumped alkali laser system: part I.

    PubMed

    Han, Juhong; Wang, You; Cai, He; Zhang, Wei; Xue, Liangping; Wang, Hongyuan

    2014-06-02

    A diode-pumped alkali laser (DPAL) is one of the most hopeful candidates to achieve high power performances. As the laser medium is in a gas-state, populations of energy-levels of a DPAL are strongly dependent on the vapor temperature. Thus, the temperature distribution directly determines the output characteristics of a DPAL. In this report, we developed a systematic model by combining the procedures of heat transfer and laser kinetics together to explore the radial temperature distribution in the transverse section of a cesium vapor cell. A cyclic iterative approach is adopted to calculate the population densities. The corresponding temperature distributions have been obtained for different beam waists and pump powers. The conclusion is thought to be useful for realizing a DPAL with high output power.

  19. Well-pump alignment system

    DOEpatents

    Drumheller, Douglas S.

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  20. Frequency stabilization of diode-laser-pumped solid state lasers

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1988-01-01

    The goal of the NASA Sunlite program is to fly two diode-laser-pumped solid-state lasers on the space shuttle and while doing so to perform a measurement of their frequency stability and temporal coherence. These measurements will be made by combining the outputs of the two lasers on an optical radiation detector and spectrally analyzing the beat note. Diode-laser-pumped solid-state lasers have several characteristics that will make them useful in space borne experiments. First, this laser has high electrical efficiency. Second, it is of a technology that enables scaling to higher powers in the future. Third, the laser can be made extremely reliable, which is crucial for many space based applications. Fourth, they are frequency and amplitude stable and have high temporal coherence. Diode-laser-pumped solid-state lasers are inherently efficient. Recent results have shown 59 percent slope efficiency for a diode-laser-pumped solid-state laser. As for reliability, the laser proposed should be capable of continuous operation. This is possible because the diode lasers can be remote from the solid state gain medium by coupling through optical fibers. Diode lasers are constructed with optical detectors for monitoring their output power built into their mounting case. A computer can actively monitor the output of each diode laser. If it sees any variation in the output power that might indicate a problem, the computer can turn off that diode laser and turn on a backup diode laser. As for stability requirements, it is now generally believed that any laser can be stabilized if the laser has a frequency actuator capable of tuning the laser frequency as far as it is likely to drift in a measurement time.

  1. Solar-pumped photodissociation iodine laser

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Weaver, W. R.; Humes, D. H.; Williams, M. D.; Lee, M. H.

    1986-01-01

    The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-W CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

  2. Long gain length solar pumped box laser

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.

    1986-01-01

    A solar pumped laser has its lasing path lengthened by forming a square loop in the lasing path by means of bending mirrors. Solar radiation is collected and concentrated into a donut shaped intensity pattern. This intensity pattern is directed onto the lasing path such that there is a maximum fit of the solar intensity pattern to the square loop laser cavity.

  3. An experimental investigation of 235 sub UF sub 6 fission produced plasmas. [gas handling system for use with nuclear pumped laser experiments

    NASA Technical Reports Server (NTRS)

    Miley, G. H.

    1981-01-01

    A gas handling system capable of use with uranium fluoride was designed and constructed for use with nuclear pumped laser experiments using the TRIGA research reactor. By employing careful design and temperature controls, the UF6 can be first transported into the irradiation chamber, and then, at the conclusion of the experiment, returned to gas cylinders. The design of the system is described. Operating procedures for the UF6 and gas handling systems are included.

  4. 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.

  5. Stable, red laser pumped, multi-kilohertz Alexandrite laser

    NASA Astrophysics Data System (ADS)

    Ogilvy, Hamish; Withford, Michael J.; Piper, James A.

    2006-04-01

    Operation of a miniature Alexandrite laser pulse-pumped at 671 nm by a Q-switched, frequency-doubled, diode-pumped Nd:GdVO4 laser is reported. Average power output ∼150 mW at 765 nm with optical-to-optical slope efficiencies of 28% has been demonstrated for gain-switched operation of the Alexandrite laser at 80 kHz. Q-switched pump-pulse stacking has been used to reduce output pulse width by a factor of 6 and increase peak power by a factor of 38 over gain-switched operation.

  6. LaRC results on nuclear pumped noble gas lasers

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.

    1979-01-01

    The recent experiment and theoretical results obtained for noble gas nuclear laser systems are presented. It is shown that the noble gas lasers are among the easiest systems to pump by nuclear excitation and as a result, all of the noble gases except He have lased under nuclear excitation. The noble gas systems are not ideal for high-power applications but they do give valuable insight into the operation and pumping mechanisms associated with nuclear lasers. At present, the Ar-Xe system is the best noble gas candidate for (U-235)F6 pumping. It appears that the quenching of Ar-Xe lasing is a result of the fluorine and not the uranium or fission fragments themselves. Thus, to achieve lasing with UF6, a fluorine compatible system must be found.

  7. Passively Q-switched side pumped monolithic ring laser

    NASA Technical Reports Server (NTRS)

    Li, Steven X. (Inventor)

    2012-01-01

    Disclosed herein are systems and methods for generating a side-pumped passively Q-switched non-planar ring oscillator. The method introduces a laser into a cavity of a crystal, the cavity having a round-trip path formed by a reflection at a dielectrically coated front surface, a first internal reflection at a first side surface of the crystal at a non-orthogonal angle with the front, a second internal reflection at a top surface of the crystal, and a third internal reflection at a second side surface of the crystal at a non-orthogonal angle with the front. The method side pumps the laser at the top or bottom surface with a side pump diode array beam and generates an output laser emanating at a location on the front surface. The design can include additional internal reflections to increase interaction with the side pump. Waste heat may be removed by mounting the crystal to a heatsink.

  8. New, Efficient Optically Pumped Solid State Lasers.

    DTIC Science & Technology

    1986-12-10

    Alexander J. Pertica , now at Lawrence Livermore National Lab., University of California, Livermore, CA 94550, "Laser Material Characteristics of Ti:Al...0 803 806 809 812 PUMP DIODE WAVELENGTH (nm) Laser Material Characteristics of Ti:AI0 3 Milton Bimbaum Alexander J. Pertica Center for Laser Studies...intrinsic material losses and to aid In the attempts to produce homogeneous and low loss Ti:AIO,. Bimbaum and Pertica -"Laowr... Characteristics of TI:A1230

  9. Investigation of the pump wavelength influence on pulsed laser pumped Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Ogilvy, H.; Withford, M. J.; Mildren, R. P.; Piper, J. A.

    2005-09-01

    Recent theoretical modelling and experimental results have shown that excess lattice phonon energy created dur ing the non-radiative energy transfer from the 4T2 pump manifold to the 2E storage level in Alexandrite when pumped with wavelengths shorter than ˜645 nm causes chaotic lasing output. Shorter pump wavelengths have also been associated with increased non-radiative energy decay and reduced laser efficiency. We report studies of fluorescence emission spectra of Alexandrite illuminated at a range of wavelengths from green to red, which demonstrate reduced fluorescence yield for shorter pump wavelengths at elevated crystal temperatures. Investigations of pulsed laser pumping of Alexandrite over the same spectral range demonstrated reduced pump threshold energy for longer pump wavelengths. High repetition rate pulsed pumping of Alexandrite at 532, 578 and 671 nm showed stable and efficient laser performance was only achieved for red pumping at 671 nm. These results support the theoretical model and demonstrate the potential for scalable, red laser pumped, all-solid-state Alexandrite lasers.

  10. 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.

  11. Fluid pumping system

    SciTech Connect

    Heath, R.T.; Gerlach, C.R.

    1986-05-13

    A fluid pumping system is described for use with a natural gas dehydrating system or the like having an absorber apparatus for removing water from wet natural gas to produce dry natural gas by use of a dessicant agent such as glycol, and a glycol treater apparatus for producing a source of dry glycol from wet glycol received from the absorber apparatus. The system consists of: a fluid pump means operatively connected between dry glycol source and absorber apparatus for pumping dry glycol from the dry glycol source to the absorber apparatus; a fluid operable piston motor means operatively associated with the pump means for driving the pump means and having fluid inlet passage means for receiving wet glycol from the absorber and fluid outlet passage means for delivering wet glycol to the glycol reboiler means wherein energy derived from the flow of fluid passing through the fluid inlet passage means provides the entire motivating force for the motor means and the pump means; the fluid pump means comprising a first pair of equal diameter chamber portion of a double acting piston means having a piston rod with two oppositely positioned piston heads at terminal ends thereof received within two oppositely positioned cylinders mounted on a fixed central body which slidably supports the piston rod; the fluid operable motor means comprising a second pair of equal diameter chamber portions of the double acting piston means; the effective areas of outwardly directed faces of the piston heads being substantially greater than the effective areas of inwardly directed faces of the piston heads; and a wet glycol passage shifting means associated with the fluid motor means for automatically changing the porting of the fluid motor means at the end of a piston stroke for producing reciprocal piston motion in the fluid motor means including toggle means actuated by the piston rod.

  12. Influence of the pump-to-laser beam overlap on the performance of optically pumped cesium vapor laser.

    PubMed

    Cohen, Tom; Lebiush, Eyal; Auslender, Ilya; Barmashenko, Boris D; Rosenwaks, Salman

    2016-06-27

    Experimental and theoretical study of the influence of the pump-to-laser beam overlap, a crucial parameter for optimization of optically pumped alkali atom lasers, is reported for Ti:Sapphire pumped Cs laser. Maximum laser power > 370 mW with an optical-to-optical efficiency of 43% and slope efficiency ~55% was obtained. The dependence of the lasing power on the pump power was found for different pump beam radii at constant laser beam radius. Non monotonic dependence of the laser power (optimized over the temperature of the Cs cell) on the pump beam radius was observed with a maximum achieved at the ratio ~0.7 between the pump and laser beam radii. The optimal temperature decreased with increasing pump beam radius. A simple optical model of the laser, where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams were assumed, was compared to the experiments. Good agreement was obtained between the measured and calculated dependence of the laser power on the pump power at different pump beam radii and also of the laser power, threshold pump power and optimal temperature on the pump beam radius. The model does not use empirical parameters such as mode overlap efficiency and can be applied to different Ti:Sapphire and diode pumped alkali lasers with arbitrary spatial distributions of the pump and laser beam widths.

  13. COMPUTER MODEL OF TEMPERATURE DISTRIBUTION IN OPTICALLY PUMPED LASER RODS

    NASA Technical Reports Server (NTRS)

    Farrukh, U. O.

    1994-01-01

    Managing the thermal energy that accumulates within a solid-state laser material under active pumping is of critical importance in the design of laser systems. Earlier models that calculated the temperature distribution in laser rods were single dimensional and assumed laser rods of infinite length. This program presents a new model which solves the temperature distribution problem for finite dimensional laser rods and calculates both the radial and axial components of temperature distribution in these rods. The modeled rod is either side-pumped or end-pumped by a continuous or a single pulse pump beam. (At the present time, the model cannot handle a multiple pulsed pump source.) The optical axis is assumed to be along the axis of the rod. The program also assumes that it is possible to cool different surfaces of the rod at different rates. The user defines the laser rod material characteristics, determines the types of cooling and pumping to be modeled, and selects the time frame desired via the input file. The program contains several self checking schemes to prevent overwriting memory blocks and to provide simple tracing of information in case of trouble. Output for the program consists of 1) an echo of the input file, 2) diffusion properties, radius and length, and time for each data block, 3) the radial increments from the center of the laser rod to the outer edge of the laser rod, and 4) the axial increments from the front of the laser rod to the other end of the rod. This program was written in Microsoft FORTRAN77 and implemented on a Tandon AT with a 287 math coprocessor. The program can also run on a VAX 750 mini-computer. It has a memory requirement of about 147 KB and was developed in 1989.

  14. Geothermal pumping systems

    SciTech Connect

    Hanold, R.J.

    1984-10-18

    After successful field testing of a prototype pressurized lubrication system designed to prevent brine intrusion and loss of lubricating oil from the motor and protector sections of electric submersible pumps, a second-generation lubrication system has been designed, fabricated, and laboratory tested. Based on a sensitive downhole pressure regulator, this system is not depth limited and it accurately controls the differential pressure between the motor oil and the external brine. The first production lengths of metal sheathed power cable have been fabricated by Halpen Engineering and delivered to REDA for testing and evaluation. Laboratory tests performed on prototype metal sheathed cable samples have demonstrated the durability of this power cable design. The East Mesa Pump Test Facility is currently being activated for high-horsepower pumping system tests that are scheduled to commence during the first quarter of FY 85. A 300-horsepower REDA pumping system equipped with a pressure regulator controlled lubrication system and a metal sheathed power cable is being fabricated for testing in this unique facility.

  15. Solar Pumped Lasers and Their Applications

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1991-01-01

    Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

  16. Solar Pumped Lasers and Their Applications

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1991-01-01

    Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

  17. Solar pumped lasers and their applications

    NASA Astrophysics Data System (ADS)

    Lee, Ja H.

    Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

  18. Solar pumped continuous wave carbon dioxide laser

    NASA Technical Reports Server (NTRS)

    Yesil, O.; Christiansen, W. H.

    1978-01-01

    In an effort to demonstrate the feasibility of a solar pumped laser concept, gain has been measured in a CO2-He laser medium optically pumped by blackbody radiation. Various gas mixtures of CO2 and He have been pumped by blackbody radiation emitted from an electrically heated oven. Using a CO2 laser as a probe, an optical gain coefficient of 1.8 x 10 to the -3rd/cm has been measured at 10.6 microns for a 9:1 CO2-He mixture at an oven temperature of about 1500 K, a gas temperature of about 400 K and a pressure of about 1 torr. This corresponds to a small signal gain coefficient when allowance is made for saturation effects due to the probe beam, in reasonable agreement with a theoretical value.

  19. Lasing properties of chromium-aluminum-doped forsterite pumped with an alexandrite laser

    SciTech Connect

    Behrens, E.G.; Jani, M.G.; Powell, R.C. ); Verdun, H.R. ); Pinto, A. )

    1991-08-01

    This paper reports on the lasing properties of chromium-aluminum-doped forsterite that were investigated using a tunable alexandrite laser as the pump source. Results of measurements of the lasing threshold, slope efficiency, spectral, and temporal profiles of the laser pulse, and the time delay between the alexandrite pump pulse and the laser emission are presented for pump wavelengths of 770, 746, and 730 nm and different pump beam energies. Laser rate equations are developed to model the lasing center as a four-level system and applied to the case of 746 nm pumping.

  20. Laser Diode Pumped Solid State Lasers

    DTIC Science & Technology

    1987-01-01

    structures, monolithic phased arrays, multiple stripe lasers which were made possible by improved manufacturing technologies su LPE and particular...mass production of single laser diodes in Japan, went a development in the U.S. which is aimed at the fabrication of powerful monolithic arrays. The...Significant progress has been made recently in developing the monolithic , linear laser diode array. Output power, slope efficiency, laser threshold and

  1. Modeling of diode pumped nanoparticle gas laser

    NASA Astrophysics Data System (ADS)

    Yang, Xu; Wang, Hongyan; Yang, Zining; Xu, Xiaojun

    2017-05-01

    The hybrid gas phase and solid state laser shows its inherent advantages in heat management and high efficiency and compactness, with DPAL becoming a perfect example. However, this kind of laser is limited by concern, for example, narrow absorption linewidth and a series of problems resulting from chemical reactions. As a matter of fact, Prof. Krupke proposed some hybrid gas phase and solid state lasers before DPAL, while they were chemically unfavored. As a newest type of hybrid gas phase and solid state laser, diode pumped nanoparticle gas laser (DPNGL) is a potential candidate in high power laser field. We put forward a rate equation model for Yb3+ doped nanoparticle gas laser, and scattering of nanoparticles at the nano scale is included in this model. In addition, modifications of fluorescence lifetime and laser emission and pump absorption cross section are coupled into this model. Some vital factors are simulated and discussed. The results obtained from the modeling show that the influence of scattering is weak, and the Yb3+ concentration is not necessarily high to achieve a good laser performance. The results are sufficiently positive for DPNGL to be a promising high power laser.

  2. 980nm diode laser pump modules operating at high temperature

    NASA Astrophysics Data System (ADS)

    Campbell, Jenna; Semenic, Tadej; Leisher, Paul; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

    2016-03-01

    Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. This problem is being addressed by the team formed by Freedom Photonics and Teledyne Scientific through the development of novel high power laser chip array architectures that can operate with high efficiency when cooled with coolants at temperatures higher than 50 degrees Celsius and also the development of an advanced thermal management system for efficient heat extraction from the laser chip array. This paper will present experimental results for the optical, electrical and thermal characteristics of 980 nm diode laser pump modules operating effectively with liquid coolant at temperatures above 50 degrees Celsius, showing a very small change in performance as the operating temperature increases from 20 to 50 degrees Celsius. These pump modules can achieve output power of many Watts per array lasing element with an operating Wall-Plug-Efficiency (WPE) of >55% at elevated coolant temperatures. The paper will also discuss the technical approach that has enabled this high level of pump module performance and opportunities for further improvement.

  3. High-power sources with smoothly adjustable pulse duration for powering gas-discharge tubes of laser pumping systems

    NASA Astrophysics Data System (ADS)

    Vakulenko, V. M.; Ivanov, L. P.; Ganshin, Y. A.; Karpyshev, I. L.; Korneyev, V. A.

    1985-10-01

    A series of power supplies for gas-discharge tubes in laser pumping systems has been developed on the basis of the same circuit but with different levels of partial discharge of the capacitive energy storing device. The charger converts the a.c. network voltage into a constant current, very efficiently and at the same charging rate regardless of the discharge level. An overall size and weight reduction is made possible by an intermediate frequency conversion from 50 Hz to 1 kHz, which also allows raising the repetition rate of output pulses. The charger consists of an inverter and a rectifier. The parallel-type inverter includes a thyristor-diode bridge with capacitors and a transformer, and a choke coil, for converting the sine-wave a.c. network voltage into a higher-frequency (1 kHz) square-wave alternating one after the first rectifying it. An important feature here is stiff overvoltage suppression, especially across the switching capacitors, during wide swings such as from no load to full load. The rectifier includes a 300/1000 V step-up transformer with another thyristor-diode bridge and a choke coil in series. A discharge commutator across the rectifier output shunted by a filter-capacitance ensures proper cutoff of the charge discharge current and corresponding control of the pulse duration.

  4. 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.

  5. Optically pumped semiconductor lasers for atomic and molecular physics

    NASA Astrophysics Data System (ADS)

    Burd, S.; Leibfried, D.; Wilson, A. C.; Wineland, D. J.

    2015-03-01

    Experiments in atomic, molecular and optical (AMO) physics rely on lasers at many different wavelengths and with varying requirements on spectral linewidth, power and intensity stability. Optically pumped semiconductor lasers (OPSLs), when combined with nonlinear frequency conversion, can potentially replace many of the laser systems currently in use. We are developing a source for laser cooling and spectroscopy of Mg+ ions at 280 nm, based on a frequency quadrupled OPSL with the gain chip fabricated at the ORC at Tampere Univ. of Technology, Finland. This OPSL system could serve as a prototype for many other sources used in atomic and molecular physics.

  6. Third order mode optically pumped semiconductor laser

    NASA Astrophysics Data System (ADS)

    De Rossi, A.; Semaltianos, N.; Chirlias, E.; Vinter, B.; Ortiz, V.; Berger, V.

    2002-06-01

    Lasing action on a third order waveguide mode is demonstrated at room temperature under optical pumping, in a specifically designed quantum well laser structure. The AlGaAs heterostructure involves barriers which ensure that the third order waveguide mode has a higher overlap with the single quantum well emitter than the fundamental mode. Third order mode operation of a laser structure opens the way to modal phase matched parametric down conversion inside the semiconductor laser itself. It is a first step towards the realization of semiconductor twin photon laser sources, needed for quantum information experiments.

  7. Diode pumped solid state kilohertz disk laser system for time-resolved combustion diagnostics under microgravity at the drop tower Bremen.

    PubMed

    Wagner, Volker; Paa, Wolfgang; Triebel, Wolfgang; Eigenbrod, Christian; Klinkov, Konstantin; Larionov, Mikhail; Giesen, Adolf; Stolzenburg, Christian

    2014-03-01

    We describe a specially designed diode pumped solid state laser system based on the disk laser architecture for combustion diagnostics under microgravity (μg) conditions at the drop tower in Bremen. The two-stage oscillator-amplifier-system provides an excellent beam profile (TEM00) at narrowband operation (Δλ < 1 pm) and is tunable from 1018 nm to 1052 nm. The laser repetition rate of up to 4 kHz at pulse durations of 10 ns enables the tracking of processes on a millisecond time scale. Depending on the specific issue it is possible to convert the output radiation up to the fourth harmonic around 257 nm. The very compact laser system is integrated in a slightly modified drop capsule and withstands decelerations of up to 50 g (>11 ms). At first the concept of the two-stage disk laser is briefly explained, followed by a detailed description of the disk laser adaption to the drop tower requirements with special focus on the intended use under μg conditions. In order to demonstrate the capabilities of the capsule laser as a tool for μg combustion diagnostics, we finally present an investigation of the precursor-reactions before the droplet ignition using 2D imaging of the Laser Induced Fluorescence of formaldehyde.

  8. Diode pumped solid state kilohertz disk laser system for time-resolved combustion diagnostics under microgravity at the drop tower Bremen

    SciTech Connect

    Wagner, Volker; Paa, Wolfgang; Triebel, Wolfgang; Eigenbrod, Christian; Klinkov, Konstantin; Larionov, Mikhail; Giesen, Adolf; Stolzenburg, Christian

    2014-03-15

    We describe a specially designed diode pumped solid state laser system based on the disk laser architecture for combustion diagnostics under microgravity (μg) conditions at the drop tower in Bremen. The two-stage oscillator-amplifier-system provides an excellent beam profile (TEM{sub 00}) at narrowband operation (Δλ < 1 pm) and is tunable from 1018 nm to 1052 nm. The laser repetition rate of up to 4 kHz at pulse durations of 10 ns enables the tracking of processes on a millisecond time scale. Depending on the specific issue it is possible to convert the output radiation up to the fourth harmonic around 257 nm. The very compact laser system is integrated in a slightly modified drop capsule and withstands decelerations of up to 50 g (>11 ms). At first the concept of the two-stage disk laser is briefly explained, followed by a detailed description of the disk laser adaption to the drop tower requirements with special focus on the intended use under μg conditions. In order to demonstrate the capabilities of the capsule laser as a tool for μg combustion diagnostics, we finally present an investigation of the precursor-reactions before the droplet ignition using 2D imaging of the Laser Induced Fluorescence of formaldehyde.

  9. A radiatively pumped CW CO2 laser

    NASA Technical Reports Server (NTRS)

    Insuik, R. J.; Christiansen, W. H.

    1984-01-01

    A proof of principle experiment to demonstrate the physics of a radiatively pumped laser has been carried out. For the first time, a blackbody cavity has optically pumped a CW CO2 laser. Results are presented from a series of experiments using mixtures of CO2, He, and Ar in which maximum output power was obtained with a 20 percent CO2-15 percent He-65 percent Ar mixture. The dependence of the output power on the blackbody temperature and the cooling gas flow rate is also discussed. By appropriately varying these parameters, continuous output powers of 8-10 mW have been achieved.

  10. Advancements in flowing diode pumped alkali lasers

    NASA Astrophysics Data System (ADS)

    Pitz, Greg A.; Stalnaker, Donald M.; Guild, Eric M.; Oliker, Benjamin Q.; Moran, Paul J.; Townsend, Steven W.; Hostutler, David A.

    2016-03-01

    Multiple variants of the Diode Pumped Alkali Laser (DPAL) have recently been demonstrated at the Air Force Research Laboratory (AFRL). Highlights of this ongoing research effort include: a) a 571W rubidium (Rb) based Master Oscillator Power Amplifier (MOPA) with a gain (2α) of 0.48 cm-1, b) a rubidium-cesium (Cs) Multi-Alkali Multi-Line (MAML) laser that simultaneously lases at both 795 nm and 895 nm, and c) a 1.5 kW resonantly pumped potassium (K) DPAL with a slope efficiency of 50%. The common factor among these experiments is the use of a flowing alkali test bed.

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

    PubMed

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

    2015-02-09

    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.

  12. Pump Diode Characterization for an Unstable Diode-Pumped Alkali Laser Resonator

    DTIC Science & Technology

    2013-03-01

    PUMP DIODE CHARACTERIZATION FOR AN UNSTABLE DIODE - PUMPED ALKALI LASER RESONATOR THESIS Chad T. Taguba, Master Sergeant, USAF AFIT-ENP-13-M-33...not subject to copyright protection in the United States. AFIT-ENP-13-M-33 PUMP DIODE CHARACTERIZATION FOR AN UNSTABLE DIODE - PUMPED ALKALI LASER ... DIODE CHARACTERIZATION FOR AN UNSTABLE DIODE - PUMPED ALKALI LASER RESONATOR Approved: Chad T. Taguba, BS Master Sergeant, USAF

  13. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  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. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  16. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  17. 54  J pulses with 18  nm bandwidth from a diode-pumped chirped-pulse amplification laser system.

    PubMed

    Hornung, Marco; Liebetrau, Hartmut; Keppler, Sebastian; Kessler, Alexander; Hellwing, Marco; Schorcht, Frank; Becker, Georg A; Reuter, Maria; Polz, Jens; Körner, Jörg; Hein, Joachim; Kaluza, Malte C

    2016-11-15

    We report on results from the fully diode-pumped chirped-pulse amplification laser system Polaris. Pulses were amplified to a maximum energy of 54.2 J before compression. These pulses have a full width at half-maximum spectral bandwidth of 18 nm centered at 1033 nm and are generated at a repetition rate of 0.02 Hz. To the best of our knowledge, these are the most energetic broadband laser pulses generated by a diode-pumped laser system so far. Due to the limited size of our vacuum compressor, only attenuated pulses could be compressed to a duration of 98 fs containing an energy of 16.7 J, which leads to a peak power of 170 TW. These pulses could be focused to a peak intensity of 1.3×1021  W/cm2. Having an ultra-high temporal contrast of 1012 with respect to amplified spontaneous emission these laser pulses are well suited for high-intensity laser-matter experiments.

  18. Algorithm for Evaluation of Temperature 3D-Distribution of a Vapor Cell in a Diode End-pumped Alkali Laser System

    NASA Astrophysics Data System (ADS)

    Han, J. H.; Wang, Y.; Cai, H.; An, G. F.; Rong, K. P.; Yu, H.; Wang, S. Y.; Wang, H. Y.; Zhang, W.; Xue, L. P.; Zhou, J.

    2017-06-01

    We develop a new 3D-model to evaluate the light characteristics and the thermal features of a cesium-vapor laser end-pumped by a laser diode. The theoretical model is based on the principles of both heat transfer and laser kinetics. The 3-dimensional population density distribution and temperature distribution are both systematically obtained and analyzed. The methodology is thought to be useful for realization of a high-powered diode-pumped alkali laser (DPAL) in the future.

  19. Pumping system for oil production

    SciTech Connect

    Yamato, I.; Yamata, T.

    1984-05-29

    A pumping system for oil production comprises a hydraulic unit set on the ground and adapted to send out a pressure oil, and a pump unit set in an oil well and adapted to draw up crude oil therefrom. The pump unit comprises a pump cylinder, and a plunger reciprocatingly moved in the pump cylinder. The plunger is provided with a clearance formed between the outer circumferential surface of a lower end portion thereof and the inner circumferential surface of the pump cylinder. The pressure oil supplied from the hydraulic unit is ejected from the clearance along the inner surface of the pump cylinder into a cylinder chamber.

  20. Well-pump alignment system

    DOEpatents

    Drumheller, D.S.

    1998-10-20

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump are disclosed, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping. 6 figs.

  1. Solar-pumped CO laser

    NASA Astrophysics Data System (ADS)

    Treanor, Charles E.

    This paper describes a method of converting thermal radiation directly into laser radiation at a wavelength of about 5 micrometers. The working fluid for the laser operation is a mixture of carbon monoxide and argon. The source of thermal radiation is assumed to be a solar oven or electrical oven operating in the range of 2000 to 2500 K. The use of carbon monoxide as the lasing material presents the advantage that the absorbing lines can be pressure broadened to permit efficient absorption of the thermal radiation without unacceptable increases in vibrational relaxation. Estimates of the efficiency, size, and power loading of such a laser are discussed.

  2. High efficiency cw laser-pumped tunable alexandrite laser

    SciTech Connect

    Lai, S.T.; Shand, M.L.

    1983-10-01

    High efficiency cw alexandrite laser operation has been achieved. With longitudinal pumping by a krypton laser in a nearly concentric cavity, a 51% output power slope efficiency has been measured. Including the transmission at the input coupler mirror, a quantum yield of 85% has been attained above threshold. Tunability from 726 to 802 nm has also been demonstrated. The low loss and good thermal properties make alexandrite ideal for cw laser operation.

  3. CW arc-lamp-pumped alexandrite lasers

    SciTech Connect

    Samelson, H.; Walling, J.C.; Wernikowski, T.; Harter, D.J.

    1988-06-01

    The performance characteristics of arc-lamp- (Xe and Hg) pumped, CW alexandrite lasers are described in detail. The modes of operation considered are free running, tuned, and repetitively Q-switched. The experimental arrangement and apparatus are also outlined. The experimental results are discussed in terms of a steady-state model, and the areas of agreement and difficulty are pointed out.

  4. Design Considerations for the Diode-pumped Laser Ignition Project

    DTIC Science & Technology

    2013-01-01

    Design Considerations for the Diode - pumped Laser Ignition Project by Jeffrey O. White ARL-TN-0526 January 2013...Design Considerations for the Diode - pumped Laser Ignition Project Jeffrey O. White Sensors and Electron Devices Directorate, ARL...August 2012 4. TITLE AND SUBTITLE Design Considerations for the Diode - pumped Laser Ignition Project 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  5. 58W LD side-pump Nd:YAG picosecond laser system at 1KHz with double length of regenerative cavity

    NASA Astrophysics Data System (ADS)

    Long, Ming Liang; Li, G.; Chen, Meng

    2016-11-01

    An average power of 58 W, pulse width of 40 ps at 1 KHz repetition rate of Nd:YAG picosecond laser is reported. It used an etalon to directly get pulse width of 135 ps from Nd:YVO4 mode locked laser in 1064 nm, which repetition rate was 88 MHz. When the seed pulses were injected into the double length of regenerative LD side-pump Nd:YAG cavity at 1 KHz repetition rate, the single pulse energy was amplified to 3 mJ, the pulse width was compressed to 99 ps, beam quality of M^2 factor was 1.3. The single pulse energy was amplified up to 58 mJ, the pulse width was self compressed to 40 ps, beam quality of M^2 factor was approximately 3.5 after single passing three stages of double high gain LD side-pump Nd:YAG module. Beam pointing was about 40 urad. The stability for pulse to pulse RMS was less than 3%. A thin-film polarizer and a quarter-wave plate was inserted into the regenerative amplification cavity to let pulses double travel the same geometric path basis on pulse polarization. Serrated aperture were used in the amplification. That's beneficial to decrease the nonlinear effect for the high power in the crystal. High gain LD side-pump Nd:YAG module could lead the pulse energy amplify more and self compress the pulse width. Double length of regenerative cavity was used to enhance the optical cavity length, it greatly decreased the laser's volume and improved stability of picosecond laser. It's a nice way for high power picosecond laser and the laser system would be more simple and smaller.

  6. New, Efficient Optically Pumped Solid State Lasers.

    DTIC Science & Technology

    1989-02-21

    Lasers", during the contract period from 15 August 1984 thru 11 November 1988 (AFOSR-88-0378) has led to some notable advances. This effort h,.s focused...lower laser states of both Er and 1Ho. This work has led to the inves t igation of the Nd,Er ion-ion interactions in other crystals such as Nd,Er:YALO...backed pyrex reflector. While the laser may work in a gold-plated cavity, the many visible, blue and near uv pump bands suggest better efficiency is

  7. Theoretical studies of solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1982-01-01

    Solar-pumped lasers were investigated by comparing experimental results from pulse experiments with steady state calculations. The time varying behavior of an IBr laser is studied. The analysis is only approximate, but indicates that conditions occurring in a pulsed experiment are quite different from those at steady state. The possibility of steady-state lasing in an IBr laser is determined. The effects of high temperatures on the quenching and recombination rates are examined. Although uncertainties in the values of the rate coefficients make it difficult to draw firm conclusions, it seems steady state running may be possible at high temperatures.

  8. Erbium Doped GaN Lasers by Optical Pumping

    DTIC Science & Technology

    2016-07-13

    P.O. Box 12211 Research Triangle Park, NC 27709-2211 Er doped GaN, gain medium, high energy laser, optical pump REPORT DOCUMENTATION PAGE 11. SPONSOR...Nanophotonics Center, Texas Tech University Lubbock, TX 79409-3102 jingyu.lin@ttu.edu; hx.jiang@ttu.edu I. Summary of Progress High energy and...emerging technologies. The optical gain medium is the heart of a high energy laser (HEL) system. Comparing with the presently dominant gain material

  9. Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers

    SciTech Connect

    Hwang, I.H. . Dept. of Physics); Lee, J.H. . Langley Research Center)

    1991-09-01

    This paper reports on the efficiencies and threshold pump intensities of various solid-state laser materials that have been estimated to compare their performance characteristics as direct solar-pumped CW lasers. Among the laser materials evaluated in this research, alexandrite has the highest slope efficiency of about 12.6%; however, it does not seem to be practical for solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AMO) solar constants and its slope efficiency is about 12% when thermal deformation is completely prevented.

  10. Pump and probe spectroscopy with continuous wave quantum cascade lasers

    SciTech Connect

    Kirkbride, James M. R.; Causier, Sarah K.; Dalton, Andrew R.; Ritchie, Grant A. D.; Weidmann, Damien

    2014-02-07

    This paper details infra-red pump and probe studies on nitric oxide conducted with two continuous wave quantum cascade lasers both operating around 5 μm. The pump laser prepares a velocity selected population in a chosen rotational quantum state of the v = 1 level which is subsequently probed using a second laser tuned to a rotational transition within the v = 2 ← v = 1 hot band. The rapid frequency scan of the probe (with respect to the molecular collision rate) in combination with the velocity selective pumping allows observation of marked rapid passage signatures in the transient absorption profiles from the polarized vibrationally excited sample. These coherent transient signals are influenced by the underlying hyperfine structure of the pump and probe transitions, the sample pressure, and the coherent properties of the lasers. Pulsed pump and probe studies show that the transient absorption signals decay within 1 μs at 50 mTorr total pressure, reflecting both the polarization and population dephasing times of the vibrationally excited sample. The experimental observations are supported by simulation based upon solving the optical Bloch equations for a two level system.

  11. Two-beam combined 3.36  J, 100  Hz diode-pumped high beam quality Nd:YAG laser system.

    PubMed

    Qiu, J S; Tang, X X; Fan, Z W; Wang, H C; Liu, H

    2016-07-20

    In this paper, we develop a diode-pumped all-solid-state high-energy and high beam quality Nd:YAG laser system. A master oscillator power amplifier structure is used to provide a high pulse energy laser output with a high repetition rate. In order to decrease the amplifier working current so as to reduce the impact of the thermal effect on the beam quality, a beam splitting-amplifying-combining scheme is adopted. The energy extraction efficiency of the laser system is 50.68%. We achieve 3.36 J pulse energy at a 100 Hz repetition rate with a pulse duration of 7.1 ns, a far-field beam spot 1.71 times the diffraction limit, and 1.07% energy stability (RMS).

  12. 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.

  13. Simulation studies for a nuclear photon pumped excimer laser

    NASA Technical Reports Server (NTRS)

    Miller, T. G.; Hagefstration, J. E.

    1979-01-01

    Simulation studies were undertaken to determine the feasibility of a nuclear photon pumped excimer laser using a system where high pressure Xe is bombarded with electrons and protons to form 1720 A. Primary measurements included conversion efficiency and gain vs time measurements.

  14. 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.

  15. 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.

  16. Integrated heat pump system

    SciTech Connect

    Reedy, W.R.

    1988-03-01

    An integrated heat pump and hot water system is described that includes: a heat pump having an indoor heat exchanger and an outdoor heat exchanger that are selectively connected to the suction line and the discharge line respectively of a compressor by a flow reversing means, and to each other by a liquid line having an expansion device mounted therein, whereby heating and cooling is provided to an indoor comfort zone by cycling the flow reversing means, a refrigerant to water heat exchanger having a hot water flow circuit in heat transfer relation with a first refrigerant condensing circuit and a second refrigerant evaporating circuit, a connection mounted in the liquid between the indoor heat exchanger and the expansion device, control means for regulating the flow of refrigerant through the refrigerant to water heat exchanger to selectively transfer heat into and out of the hot water flow circuit.

  17. All fiber thulium-doped fiber laser pumped Q-switched Ho:YAP laser

    NASA Astrophysics Data System (ADS)

    Yu, Ting; Ye, Xisheng; Yang, Zhongguo; Chen, Xiaolong; Xia, Wenbin; Zhang, Jiayang; Zhang, Wei; Chen, Jianyu; Si, Jiliang; Chen, Weibiao

    2017-05-01

    The high power infrared 2μm lasers have been extensively investigated for a number of commercial, scientific and engineering applications, such as remote chemical sensing, medical diagnostics, eye-safe laser radar, and environmental monitoring. Furthermore, high-power 2μm lasers are effective pump sources of optical parametrical oscillators and optical parametrical amplifications to generate mid-infrared 3-5μm laser. In recent years, Ho:YAlO3(Ho:YAP) crystal has drawn great attention as a promising efficient laser material for its long emission wavelength at 2118nm. An acoustic-optical Q-switched Ho:YAP laser pumped by an all fiber thulium-doped fiber laser is demonstrated. The all fiber thulium-doped fiber laser can emit 80W output power, and the output laser wavelength is 1915nm. By using this 1915nm laser to end pump the AO Q-switched Ho:YAP laser system, 2118nm laser with 30W average power and 45ns pulse width at 20kHz repetition rates was obtained.

  18. Microwave accelerator E-beam pumped laser

    DOEpatents

    Brau, Charles A.; Stein, William E.; Rockwood, Stephen D.

    1980-01-01

    A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

  19. Nd:YAG laser diode-pumped directly into the emitting level at 938 nm.

    PubMed

    Sangla, Damien; Balembois, François; Georges, Patrick

    2009-06-08

    We present the first demonstration of Nd:YAG laser pumped directly in band at 938 nm with a high-brightness fiber-coupled laser diode. Up to 6 W of CW laser emission at 1064 nm have been obtained under an absorbed pump power of 28 W at 938 nm. A comparison between 808 nm and 938 nm pumping, realized by thermal cartography, demonstrates the very low heat generation of in-band pumping. Numerical simulations were also implemented to study and discuss the laser performance of our system.

  20. Revisiting of LED pumped bulk laser: first demonstration of Nd:YVO₄ LED pumped laser.

    PubMed

    Barbet, Adrien; Balembois, François; Paul, Amandine; Blanchot, Jean-Philippe; Viotti, Anne-Lise; Sabater, Jacques; Druon, Frédéric; Georges, Patrick

    2014-12-01

    We describe here what is, to the best of our knowledge, the first LED pumped Nd:YVO₄ laser. Near-IR LED arrays with a wavelength centered close to 850 nm were used to pump transversely the crystal. By pulsing LEDs, with a duration of the order of the laser transition lifetime, we obtained sufficient pump intensities to reach the laser threshold. At a frequency of 250 Hz, we obtained an output energy of 40 μJ at 1064 nm for an input pump energy of 7.4 mJ, which corresponds to an optical efficiency of 0.5%. Experimental results of small signal gain are compared with theoretical analysis.

  1. Optimized high-power diode laser, laser arrays, and bars for pump applications

    NASA Astrophysics Data System (ADS)

    Hülsewede, R.; Schulze, H.; Sebastian, J.; Schröder, D.; Meusel, J.; Wolf, J.; Hennig, P.

    2009-02-01

    Broad area diode laser and diode laser bars are the most efficient light sources. In comparison to solid state laser or gas laser systems the over all beam quality of the diode laser is poor. Thus most application of diode laser bars is high efficient pumping of solid state lasers converting the beam quality and scaling the power of laser systems within the kW range. The pump efficiency and the beam coupling efficiency of the diode laser pumped systems has to be increased to meet the increasing laser market demands for reduced costs. JENOPTIK Diode Lab GmbH (JDL) has optimized their high power brilliance bars to enable reliable high power operation especially, for the 9xx nm wavelength range and low far field divergences. Superior reliability with long operation time of 13,000 hours and high power operation of 200 W are demonstrated for high power bars high filling factor mounted on passively cooled heat sinks. Smaller far field divergence at high power levels requires longer cavity length and higher efficiencies in the beam coupling needs requires lower filling factors. The new high brilliance bars and arrays with 20% filling factor are showing high power operation up to 95 W and a slow axis beam divergence of less than 8° (95% power content).

  2. Efficient bone cutting with the novel diode pumped Er:YAG laser system: in vitro investigation and optimization of the treatment parameters

    NASA Astrophysics Data System (ADS)

    Stock, Karl; Diebolder, Rolf; Hausladen, Florian; Hibst, Raimund

    2014-03-01

    It is well known that flashlamp pumped Er:YAG lasers allow efficient bone ablation due to strong absorption at 3μm by water. Preliminary experiments revealed also a newly developed diode pumped Er:YAG laser system (Pantec Engineering AG) to be an efficient tool for use for bone surgery. The aim of the present in vitro study is the investigation of a new power increased version of the laser system with higher pulse energy and optimization of the treatment set-up to get high cutting quality, efficiency, and ablation depth. Optical simulations were performed to achieve various focus diameters and homogeneous beam profile. An appropriate experimental set-up with two different focusing units, a computer controlled linear stage with sample holder, and a shutter unit was realized. By this we are able to move the sample (slices of pig bone) with a defined velocity during the irradiation. Cutting was performed under appropriate water spray by moving the sample back and forth. After each path the ablation depth was measured and the focal plane was tracked to the actual bottom of the groove. Finally, the cuts were analyzed by light microcopy regarding the ablation quality and geometry, and thermal effects. In summary, the results show that with carefully adapted irradiation parameters narrow and deep cuts (ablation depth > 6mm, aspect ratio approx. 20) are possible without carbonization. In conclusion, these in vitro investigations demonstrate that high efficient bone cutting is possible with the diode pumped Er:YAG laser system using appropriate treatment set-up and parameters.

  3. LD dual-end-pumped CW Tm:YLF laser

    NASA Astrophysics Data System (ADS)

    Chen, Xin-yu; Zhang, Yu; Yu, Yong-ji; Wang, Chao; Jin, Guang-yong

    2013-09-01

    We report on a LD dual-end-pumped 792nm continuous wave operation Tm:YLF laser. Firstly, the rate equation of LD end-pumped CW operation Tm:YLF laser were established, in which the energy transfer upconversion and without energy transfer upconversion under continuous-wave considerate were considered, as well the pump threshold and the slope efficiency of the laser system were analyzed. Simultaneously, the cavity stability condition and the pattern matching of the plano- concave resonator were analyzed according to ABCD Matrix theory. Comparing respectively the laser threshold and the slope efficiency and optical-optical conversion efficiency under circumstances which the output mirror transmittance of 15% and 23%. In addition, the M2 of the output laser were contrasted and analyzed in adjusting the resonator cavity length by using different radius of curvature of the output mirror in 150mm, 200mm and 300mm all in the above case. As the process of thermal lens focal length changing greater than 90mm, it exhibited that the two fundamental modes in the cavity resonator matched well in numerical simulation when the radius of curvature of the output mirror was 300mm, as well the two fundamental modes matched well when it more than 100mm in a certain pump power. We designed a single LD dual-end-pumped continuous wave operation Tm:YLF laser. Using Tm:YLF (3 at.%) crystal for gain medium, which the size was 3×3×14mm3. In experiments, the Tm:YLF laser crystal keeps 291K and the temperature control method is water cooling. The length of the resonator was 135mm when L shape plano-concave resonator was applied, and the radius of curvature output mirror was 300mm, as well as the temperature of the Tm:YLF laser crystal was 291K. The output laser we observed by this system and the central laser wavelength was 1944nm. The threshold power was 8.11W and the highest output power reaches to 4.01W when the totally input pump power was 17W, and the optical conversion efficiency was 23

  4. Diode pumped solid-state laser oscillators for spectroscopic applications

    NASA Technical Reports Server (NTRS)

    Byer, R. L.; Basu, S.; Fan, T. Y.; Kozlovsky, W. J.; Nabors, C. D.; Nilsson, A.; Huber, G.

    1987-01-01

    The rapid improvement in diode laser pump sources has led to the recent progress in diode laser pumped solid state lasers. To date, electrical efficiencies of greater than 10 percent were demonstrated. As diode laser costs decrease with increased production volume, diode laser and diode laser array pumped solid state lasers will replace the traditional flashlamp pumped Nd:YAG laser sources. The use of laser diode array pumping of slab geometry lasers will allow efficient, high peak and average power solid state laser sources to be developed. Perhaps the greatest impact of diode laser pumped solid state lasers will be in spectroscopic applications of miniature, monolithic devices. Single-stripe diode-pumped operation of a continuous-wave 946 nm Nd:YAG laser with less than 10 m/w threshold was demonstrated. A slope efficiency of 16 percent near threshold was shown with a projected slope efficiency well above a threshold of 34 percent based on results under Rhodamine 6G dye-laser pumping. Nonlinear crystals for second-harmonic generation of this source were evaluated. The KNbO3 and periodically poled LiNbO3 appear to be the most promising.

  5. Femtosecond Cr:LiSAF and Cr:LiCAF lasers pumped by tapered diode lasers.

    PubMed

    Demirbas, Umit; Schmalz, Michael; Sumpf, Bernd; Erbert, Götz; Petrich, Gale S; Kolodziejski, Leslie A; Fujimoto, James G; Kärtner, Franz X; Leitenstorfer, Alfred

    2011-10-10

    We report compact, low-cost and efficient Cr:Colquiriite lasers that are pumped by high brightness tapered laser diodes. The tapered laser diodes provided 1 to 1.2 W of output power around 675 nm, at an electrical-to-optical conversion efficiency of about 30%. Using a single tapered diode laser as the pump source, we have demonstrated output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% from continuous wave (cw) Cr:LiSAF and Cr:LiCAF lasers, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetition rates around 100 MHz. Upon pumping the Cr:Colquiriite lasers with two tapered laser diodes (one from each side of the crystal), we have observed scaling of cw powers to 850 mW in Cr:LiSAF and to 650 mW in Cr:LiCAF. From the double side pumped Cr:LiCAF laser, we have also obtained ~220 fs long pulses with 5.4 nJ of pulse energy at 77 MHz repetition rate. These are the highest energy levels reported from Cr:Colquiriite so far at these repetition rates. Our findings indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of Cr:Colquiriite systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region (750-1000 nm).

  6. University of Florida nuclear pumped laser program. [excitation of laser gaseous

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.

    1979-01-01

    The mechanism of excitation of laser gases by fast ions (triton, proton, or fission fragments) and especially any role UF6 might play in radiative deexcitation of these gases were investigated. Population densities of excited important for laser action were obtained. Nuclear pumped CW-laser systems, especially He-Ne and CO2, were studied using steady state reactors. It was demonstrated that He-Ne lases in a CW-mode with nuclear pumping at both the red and the infrared transition. The infrared transition was observed to be superradiant.

  7. Wavelength diversity in optically pumped alkali vapor lasers

    NASA Astrophysics Data System (ADS)

    Perram, Glen P.

    2017-01-01

    Alternative wavelengths for optically pumped alkali vapor lasers have been developed using single photon excitation of higher lying P-states, stimulated Raman processes, two-photon excitation of S and D states, and electric quadruple excitation on S-D transitions. Two photon excitation of Cs 72D leads to competing and cascade lasing producing red and infrared lasers operating on the D-P transitions, followed by ultraviolet, blue, the standard near infrared DPAL transitions operating on P-S transitions. The S-D pump transitions are fully bleached at pump intensities exceeding 1 MW/cm2, allowing for lasing transitions that terminate on the ground state. The kinetics of these systems are complex due to competition for population inversion among the many optical transitions. An optically pumped mid-infrared rubidium pulsed, mirrorless laser has also been demonstrated in a heat pipe along both the 62P3/2 - 62S1/2 transition at 2.73 μm and the 62P1/2 - 62S1/2 transition at 2.79 μm with a maximum energy of 100 nJ. Performance improves dramatically as the rubidium vapor density is increased, in direct contradiction with the prior work. No scaling limitations associated with energy pooling or ionization kinetics have been observed. Practical application for infrared counter measures depends on the further development of blue diode pump sources. Finally, stimulated electronic Raman scattering and hyper-Raman processes in potassium vapor near the D1 and D2 lines have been observed using a stable resonator and pulsed laser excitation. First and second order Stokes and anti-Stokes lines were observed simultaneously and independently for a pump laser tuning range exceeding 70 cm-1. When the pump is tuned between the K D1 and D2 lines, an efficient hyper-Raman process dominates with a slope efficiency that exceeds 10%. Raman shifted laser may be useful as a target illuminator or atmospheric compensation beacon for a high power diode pumped alkali laser.

  8. Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers

    NASA Technical Reports Server (NTRS)

    Hwang, In H.; Lee, Ja H.

    1991-01-01

    The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.

  9. Lasers pumped by solar radiation (Review)

    NASA Astrophysics Data System (ADS)

    Golger, A. L.; Klimovskii, I. I.

    1984-02-01

    Theoretical models and existing experimental data on solar-pumped lasers are surveyed. Necessary conditions for lasing to occur are defined, including the necessity that the chemical used must be stable to solar radiation. Attention is given to photodissociation gas lasers such as RI, IBr and CO2-Br2 lasers, molecular gas lasers such as CO2 devices and four-level solid-state lasers, e.g., YAG:Nd and waveguide lasers. Consideration is devoted to efficiencies optimized by the selection of specific values for the density, absorption cross-section of the active media, the rate of de-excitation, the transverse dimensions of the active medium and necessary levels of solar concentration. The discussion reveals that only the closed cycle gas dynamic laser and a solid-state waveguide laser can currently produce 3-6 percent efficiency operation, the latter requiring only 100 suns concentration for a 100 W output. Configurations of arrays of transversely concentrating parabolic heliostats to produce sufficient power for energy applications are discussed.

  10. Dynamics of photon-induced processes in adsorbate-surface systems studied by laser-synchrotron pump-probe techniques

    NASA Astrophysics Data System (ADS)

    Winter, Bernd J.; Gatzke, Johannes; Quast, T.; Will, Ingo; Wick, Manfred T.; Liero, A.; Pop, D.; Hertel, Ingolf V.

    1998-12-01

    We report on the MBI User Facility at BESSY II, presently under construction, which is dedicated to study the dynamics of photo-induced processes by combining laser and synchrotron pulses. In this paper we focus on the synchronization of a modelocked ultrafast Ti:sapphire laser to the Berlin electron storage ring for synchrotron radiation (BESSY). Two different techniques have been applied -- one based on a digital phase comparator and the other based on analog high-harmonic mixing. Both schemes may be easily adjusted to either single, multi- or hybrid-bunch operation of the synchrotron. Moreover, the temporal accuracy of the synchronization unit suitably matches the widths of the synchrotron pulses (some ten picoseconds) to be expected at BESSY II. Therefore, the currently performed test experiments at BESSY I provide the basis for time- resolved photon-induced experiments which combine laser and SR-undulator pulses in a pump-probe scheme at BESSY II. This facility will be available within the first half of 1999.

  11. Vacuum pumping system for TPX

    SciTech Connect

    St. Onge, K.D.

    1995-12-31

    The design of the vacuum pumping system for is discussed, and progress in the research and development effort is summarized. The TPX vacuum system will use cryocondensation pumps for hydrogenic divertor pumping and turbomolecular pumps for torus evacuation, glow discharge cleaning, and deuterium-helium divertor pumping. A set of poloidally and toroidally symmetric vacuum ducts will connect the torus to the vacuum pumps; this symmetry will permit simultaneous equal pumping speed at the upper and lower divertors, and it will minimize toroidal variations in divertor pumping speed. At the divertor plena the total cryocondensation pumping speed for D{sub 2} at 65 C and 1 mTorr will be 80 m{sup 3}/s and the total turbomolecular pumping speed for D{sub 2} or He at 65 C and 1 mTorr will be 18 m{sup 3}/s; the system will be compatible with upgrades to improve pumping speed, to operate continuously, or to operate with D-T fuel. The cryocondensation pumps will be custom units capable of completing a low temperature regeneration cycle in 1 hour.

  12. Fuel pumping system and method

    DOEpatents

    Shafer, Scott F.; Wang, Lifeng ,

    2006-12-19

    A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

  13. Fuel Pumping System And Method

    DOEpatents

    Shafer, Scott F.; Wang, Lifeng

    2005-12-13

    A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

  14. Some factors affecting the pumping efficiency of optically pumped lasers.

    PubMed

    Edwards, J G

    1967-05-01

    As a preliminary to the calculation and discussion of pumping efficiency, the results of an investigation into the properties of xenon flash tubes are given. Time resolved spectroscopy showed that the radiation during the flash is essentially that of a blackbody. The small range of measured blackbody temperatures (6000 degrees K to 7000 degrees K) cannot account for the variation in radiated power during the flash. However, emissivity variations (deduced from published absorption data) explain the observed time dependence exactly. An ionic mechanism is outlined which explains the spectral distribution of the radiation, the electrical properties of the discharge, and the emissivity variations. Possible reasons for the low radiative efficiency of 28% during the flash are discussed. The fraction of the electrical energy supplied to the tube reaching the laser crystal is calculated, taking into account the cavity geometry and wall reflectivity, the flash tube radiative efficiency and spectral distribution, the crystal ze and sorption, and the partial reconversion by the flash tube of light not absorbed in the crystal which returns to the tube. The predicted laser oscillation threshold agrees well with experiment. It is concluded that, while reconversion can significantly increase the effective radiative efficiency of the tube, the over-all efficiency of the laser is still limited by the low intrinsic radiative efficiency. Numerical examples are given to show that this parameter exercises the biggest influence on the present pumping efficiencies of about 0.5%. Over-all efficiencies of up to 9% could be obtained if this radiative efficiency could be raised to about 90%. Success in this area could give greater benefits than attempts to improve the spectral distribution of the tube radiation.

  15. Grating THz laser with optical pumping

    NASA Astrophysics Data System (ADS)

    Khoury, Jed; Haji-saeed, Bahareh; Woods, Charles; Kierstead, John

    2010-04-01

    In this paper, we present a design for a widely tunable solid-state optically and electrically pumped THz laser based on the Smith-Purcell free-electron laser. In the free-electron laser, an energetic electron beam pumps a metallic grating to generate surface plasmons. Our solid-state optically pumped design consists of a thin layer of dielectic, such as SiNx, sandwiched between a corrugated structure and a thin metal or semiconductor layer. The lower layer is for current streaming, and replaces the electron beam in the original design. The upper layer consists of one micro-grating for coupling the electromagnetic field in, another for coupling out, and a nano-grating for coupling with the current in the lower layer for electromagnetic field generation. The surface plasmon waves generated from the upper layer by an external electromagnetic field, and the lower layer by the applied current, are coupled. Emission enhancement occurs when the plasmonic waves in both layers are resonantly coupled.

  16. Optically (solar) pumped oxygen-iodine lasers

    NASA Astrophysics Data System (ADS)

    Danilov, O. B.; Zhevlakov, A. P.; Yur'ev, M. S.

    2014-07-01

    We present the results of theoretical and experimental studies demonstrating the possibility of developing an oxygen-iodine laser (OIL) with direct optical pumping of molecular oxygen involving inter-molecular interaction with charge transfer from donor molecule (buffer gas) to acceptor molecule (oxygen). This interaction lifts degeneracy of the lower energy states of molecular oxygen and increases its absorption cross section in the visible spectral region and the UV Herzberg band, where high quantum yield of singlet oxygen is achieved (QY ˜ 1 and QY ˜ 2, respectively) at the same time. A pulse-periodic optical pump sources with pulse energy of ˜50 kJ, pulse duration of ˜25 μs, and repetition rate of ˜10 Hz, which are synchronized with the mechanism of singlet oxygen generation, are developed. This allows implementation of a pulse-periodic oxygen-iodine laser with an efficiency of ˜25%, optical efficiency of ˜40%, and parameter L/ T ˜ 1/1.5, where T is the thermal energy released in the laser active medium upon generation of energy L. It is demonstrated that, under direct solar pumping of molecular oxygen, the efficiency parameter of the OIL can reach L/ T ˜ 1/0.8 in a wide range of scaling factors.

  17. Applications for reactor-pumped lasers

    NASA Astrophysics Data System (ADS)

    Lipinski, R. J.; McArthur, D. A.

    Nuclear reactor-pumped lasers (RPL's) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

  18. Applications for reactor-pumped lasers

    SciTech Connect

    Lipinski, R.J.; McArthur, D.A.

    1994-10-01

    Nuclear reactor-pumped lasers (RPLs) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

  19. A blackbody radiation-pumped CO2 laser experiment

    NASA Astrophysics Data System (ADS)

    Christiansen, W. H.; Insuik, R. J.; Deyoung, R. J.

    1982-09-01

    Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping.

  20. Advanced solar energy conversion. [solar pumped gas lasers

    NASA Technical Reports Server (NTRS)

    Lee, J. H.

    1981-01-01

    An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

  1. 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.

  2. Nuclear-driven flashlamp pumping of the atomic iodine laser

    SciTech Connect

    Miley, G.H.

    1992-03-01

    This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

  3. Efficiency of Nd laser materials with laser diode pumping

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Cross, Patricia L.; Skolaut, Milton W., Jr.; Storm, Mark E.

    1990-01-01

    For pulsed laser-diode-pumped lasers, where efficiency is the most important issue, the choice of the Nd laser material makes a significant difference. The absorption efficiency, storage efficiency, and extraction efficiency for Nd:YAG, Nd:YLF, Nd:GSGG, Nd:BEL, Nd:YVO4, and Nd:glass are calculated. The materials are then compared under the assumption of equal quantum efficiency and damage threshold. Nd:YLF is found to be the best candidate for the application discussed here.

  4. A high-repetition rate scheme for synchrotron-based picosecond laser pump/x-ray probe experiments on chemical and biological systems in solution.

    PubMed

    Lima, Frederico A; Milne, Christopher J; Amarasinghe, Dimali C V; Rittmann-Frank, Mercedes Hannelore; van der Veen, Renske M; Reinhard, Marco; Pham, Van-Thai; Karlsson, Susanne; Johnson, Steven L; Grolimund, Daniel; Borca, Camelia; Huthwelker, Thomas; Janousch, Markus; van Mourik, Frank; Abela, Rafael; Chergui, Majed

    2011-06-01

    We present the extension of time-resolved optical pump/x-ray absorption spectroscopy (XAS) probe experiments towards data collection at MHz repetition rates. The use of a high-power picosecond laser operating at an integer fraction of the repetition rate of the storage ring allows exploitation of up to two orders of magnitude more x-ray photons than in previous schemes based on the use of kHz lasers. Consequently, we demonstrate an order of magnitude increase in the signal-to-noise of time-resolved XAS of molecular systems in solution. This makes it possible to investigate highly dilute samples at concentrations approaching physiological conditions for biological systems. The simplicity and compactness of the scheme allows for straightforward implementation at any synchrotron beamline and for a wide range of x-ray probe techniques, such as time-resolved diffraction or x-ray emission studies.

  5. Mode-coupling enhancement by pump astigmatism correction in a Ti:Sapphire femtosecond laser.

    PubMed

    Ramírez-Guerra, Catalina; Moreno-Larios, José Agustín; Rosete-Aguilar, Martha; Garduño-Mejía, Jesús

    2016-12-01

    To pump a solid-state femtosecond laser cavity, a beam from a CW laser is focused by a single lens into the laser crystal. To increase the output power of the laser, the overlap of the laser mode with the pump mode should be maximized. This is particularly important in the so-called mode coupling and the Kerr-lens mode locking (KLM) operation, where the change in beam waist at the position of the gain medium is exploited to enhance the mode overlap with the pump laser in the crystal. In this paper, the astigmatism in the pump beam is reduced by tilting the pump lens. A Gaussian beam is propagated through the complete focusing system-pump lens, tilted spherical mirror, and crystal cut at Brewster's angle-to show the astigmatism inside the crystal as a function of the tilt of the pump lens. A genetic algorithm is presented to optimize the mode coupling between the pump and laser beam inside the crystal by tilting the pump lens. Experimental results are presented to verify the design, showing an increase in the output power of the laser cavity of about 20%.

  6. Optimal pumping for eye-safe Er:YAG laser

    NASA Astrophysics Data System (ADS)

    Buchenkov, Vyacheslav A.; Polyakov, Vadim M.; Rodionov, Andrey Y.; Kovalev, Anton V.

    2016-04-01

    We report on theoretical investigation of quasi-three level Er:YAG laser. We propose a numerical model of the laser design with side pump by 1471 nm laser diodes. The model describes the dynamical propagation of the pump in the cavity and the kinetic parameters of the active medium.

  7. Amplified spontaneous emission in solar-pumped iodine laser

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  8. Amplified spontaneous emission in solar-pumped iodine laser

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  9. Modeling of pulsed Cs vapor lasers in transversely pumped configuration

    NASA Astrophysics Data System (ADS)

    Zi, Fei; Zhang, Xian; Ma, Xiaoxiao; Huang, Kaikai; Lu, Xuanhui

    2017-06-01

    By means of combining the transverse differential equation of pump intensity and the longitudinal differential equation of laser power, an optical model for transversely pumped diode-pumped alkali vapor lasers (DPALs) is established. The spatial distributions of both radius and intensities are considered in the model for pump and laser beams. The simulation results are in good agreement with the experiment ones as compared to the reported pulsed transversely pumped Cs DPALs. Influences of pump power, temperature, cell length, and beam waist on output performance are investigated, which suggests a set of parameters for efficient DPAL operation. In particular, the optimal ratio of the beam waist between the laser and pump beam is demonstrated to be 0.81, which can increase the laser power by 85% larger than the current experimental result.

  10. Solid-state laser pumping by light guides

    SciTech Connect

    Bernardes, Pedro H.; Liang Dawei

    2006-06-01

    What we believe to be novel pumping schemes for lamp-pumped solid-state lasers are proposed. Based on the refractive and total internal reflection principles, curved fused-silica light guides of rectangular cross sections are used to couple the pump radiation from an arc lamp into a laser crystal. The performances of light-guide pumping schemes are analyzed through a nonsequential ray-trace program and are compared to that of a single elliptical cavity. Improved pump radiation distribution around the laser crystal was registered. The light-guide cavities also permit tailoring the pump flux distribution within the active medium. A lamp-pumped Nd:YAG laser by alight-guide cavity was built and tested. An overall laser efficiency of 1.1% was measured.

  11. Satellite Power System (SPS) laser studies. Volume 2: Meteorological effects on laser beam propagation and direct solar pumped lasers for the SPS

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The primary emphasis of this research activity was to investigate the effect of the environment on laser power transmission/reception from space to ground. Potential mitigation techniques to minimize the environment effect by a judicious choice of laser operating parameters was investigated. Using these techniques, the availability of power at selected sites was determined using statistical meteorological data for each site.

  12. a Blackbody-Pumped Carbon Dioxide Laser

    NASA Astrophysics Data System (ADS)

    Insuik, Robin Joy

    A proof of concept experiment has been carried out to demonstrate the feasibility of using blackbody radiation to pump a gas laser. Building on earlier experiments in which optical gain was measured in a CO(,2) laser mixture exposed to blackbody radiation at a temperature of 1500(DEGREES)K, continuous wave oscillation of CO(,2) has been achieved, for the first time, using radiation from a blackbody cavity as the pump source. This was made possible by actively cooling the laser mixture as it was exposed to the radiation field of an electrically heated oven. Output power measurements are presented from a series of experiments using mixtures of CO(,2), He, and Ar. Maximum output power was obtained with a 20%CO(,2) - 15%He- 65%Ar mixture at pressures around 6-10 Torr. The output power was found to vary greatly with the gas temperature and the blackbody temperature. By varying these parameters output powers up to 8 mW have been achieved. The effects of the buffer gas are also shown to be important. Based on the experimental results, it is believed that the buffer gas is needed to inhibit diffusion of the excited species out of the laser mode volume. This diffusion leads to deactivation at the walls. Adding more CO(,2) results in a decrease in output power, indicating that the gas has a finite optical depth and the mode volume is not pumped if too much CO(,2) is present. A model which incorporates these effects is presented. The predicted small signal gains and powers based on this model adequately match the trends observed experimentally.

  13. Multimode-diode-pumped gas (alkali-vapor) laser

    SciTech Connect

    Page, R H; Beach, R J; Kanz, V K

    2005-08-22

    We report the first demonstration of a multimode-diode-pumped gas laser--Rb vapor operating on the 795 nm resonance transition. Peak output of {approx}1 Watt was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

  14. Multimode-diode-pumped gas (alkali-vapor) laser.

    PubMed

    Page, Ralph H; Beach, Raymond J; Kanz, V Keith; Krupke, William F

    2006-02-01

    We report what we believe to be the first demonstration of a multimode-diode-pumped gas laser: Rb vapor operating on the 795 nm D1 resonance transition. Peak output of approximately 1 W was obtained using a volume-Bragg-grating stabilized pump diode array. The laser's output radiance exceeded the pump radiance by a factor greater than 2000. Power scaling (by pumping with larger diode arrays) is therefore possible.

  15. 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.

  16. Diode-pumped 10 W continuous wave cesium laser.

    PubMed

    Zhdanov, Boris; Knize, R J

    2007-08-01

    An efficient cesium vapor laser pumped with a continuous wave laser diode array has been demonstrated. The linewidth of the pump source was narrowed using the external cavity to match it to the cesium absorption line. The output power of the continuous wave cesium laser was 10 W, which exceeds previous results by more than a factor of 10, and the slope efficiency was 68%. The overall optical efficiency was 62%, which is a factor of 6 higher than previous pulsed laser results for alkali lasers with diode laser array pumping.

  17. Multi-photon microscope driven by novel green laser pump

    NASA Astrophysics Data System (ADS)

    Marti, Dominik; Djurhuus, Martin; Jensen, Ole Bjarlin; Andersen, Peter E.

    2016-03-01

    Multi-photon microscopy is extensively used in research due to its superior possibilities when compared to other microscopy modalities. The technique also has the possibility to advance diagnostics in clinical applications, due to its capabilities complementing existing technology in a multimodal system. However, translation is hindered due to the high cost, high training demand and large footprint of a standard setup. We show in this article that minification of the setup, while also reducing cost and complexity, is indeed possible without compromising on image quality, by using a novel diode laser replacing the commonly used conventional solid state laser as the pump for the femtosecond system driving the imaging.

  18. Design of diode-pumped solid-state laser applied in laser fuses

    NASA Astrophysics Data System (ADS)

    Deng, FangLin; Zhang, YiFei

    2005-04-01

    The function of laser fuzes which are parts of certain weapon systems is to control the blasting height of warheads. Commonly the battle environment these weapon systems are confronted with is very complicated and the tactical demand for them is very rigor, so laser fuzes equipped for them must fulfill some special technical requirements, such as high repetition rate, long ranging scope, etc. Lasers are one of key components which constitute fuze systems. Whether designed lasers are advanced and reasonable will determine whether laser fuzes can be applied in these weapon systems or not. So we adopt the novel technology of diode-pumped solid-state laser (DPSSL) to design lasers applied in fuzes. Nd:YVO4 crystal is accepted as gain material, which has wide absorption band and large absorption efficient for 808nm pumping laser. As warhead's temperature is usually very high, wider absorption band is beneficial to reduce the influence of temperature fluctuation. Passive Q-switching with Cr4+:YAG is used to reduce the power consumption farthest. Design the end-pumped microchip sandwich-architecture to decrease lasers' size and increase the reliability, further it's advantageous to produce short pulses and increase peak power of lasers. The designed DPSSL features small size and weight, high repetition rate and peak power, robustness, etc. The repetition rate is expected to reach 1 kHz; peak power will exceed 300 kW; pulse width is only 5 ns; and divergence angle of laser beams is less than 5 mrad. So DPSSL is suitable for laser fuzes as an emitter.

  19. Highly-efficient high-power pumps for fiber lasers

    NASA Astrophysics Data System (ADS)

    Gapontsev, V.; Moshegov, N.; Berezin, I.; Komissarov, A.; Trubenko, P.; Miftakhutdinov, D.; Berishev, I.; Chuyanov, V.; Raisky, O.; Ovtchinnikov, A.

    2017-02-01

    We report on high efficiency multimode pumps that enable ultra-high efficiency high power ECO Fiber Lasers. We discuss chip and packaged pump design and performance. Peak out-of-fiber power efficiency of ECO Fiber Laser pumps was reported to be as high as 68% and was achieved with passive cooling. For applications that do not require Fiber Lasers with ultimate power efficiency, we have developed passively cooled pumps with out-of-fiber power efficiency greater than 50%, maintained at operating current up to 22A. We report on approaches to diode chip and packaged pump design that possess such performance.

  20. Scalable high-power optically pumped GaAs laser

    NASA Astrophysics Data System (ADS)

    Le, H. Q.; di Cecca, S.; Mooradian, A.

    1991-05-01

    The use of disk geometry, optically pumped semiconductor gain elements for high-power scalability and good transverse mode quality has been studied. A room-temperature TEM00 transverse mode, external-cavity GaAs disk laser has been demonstrated with 500 W peak-power output and 40-percent slope efficiency, when pumped by a Ti:Al2O3 laser. The conditions for diode laser pumping are shown to be consistent with available power level.

  1. A Modular Control Platform for a Diode Pumped Alkali Laser

    DTIC Science & Technology

    2008-09-01

    A Modular Control Platform for a Diode Pumped Alkali Laser Joshua Shapiro, Scott W. Teare New Mexico Institute of Mining and Technology, 801 Leroy...gain media, such as is done in diode pumped alkali lasers (DPALs), has been proposed and early experiments have shown promising results. However...REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE A Modular Control Platform for a Diode Pumped Alkali Laser 5a

  2. 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.

  3. Diode laser pumping sources for cryogenically cooled solid-state lasers

    NASA Astrophysics Data System (ADS)

    Maiorov, M. A.; Trofimov, I. E.

    2008-04-01

    One of the recent advances in solid-state laser (SSL) defense technology is the 100W level Er-doped "eye-safe" laser with low quantum defect pumping at 1.53μm. Major technical challenges in achieving high-wattage devices include increasing the system power conversion efficiency and arranging the removal of heat from both the crystal and the pumps. It is known that performance of the crystal can be improved dramatically by cryogenic cooling. Hence, it is desirable to have cryo-cooled pumps to realize ergonomic and efficient diode-pumped SSL with unified cryogenic cooling. In this paper we report on the development of LN2-cooled InP-based λ~1.5-1.6 μm diode pumps. The broad area lasers demonstrated 11W in continuous-wave (CW) regime at an operating current of 20A. Despite the highest CW power measured to date from an InP-based emitter, we did not observe catastrophic optical mirror damage. The spectral width of the radiation from a cooled device decreased 1.5-2 from its room-temperature value, which will significantly improve pumping efficiency. We show that laser diode design has to be optimized for performance at cryogenic temperatures. Reviewing the data on LN2 cooled lasers emitting in the wavelength range of 1.13 - 1.8 μm, we discuss the route to increase the power conversion of the LN2 cooled InP-based pumps to greater than 60% and further narrow and stabilize the laser emission spectrum.

  4. Unidirectionality of an optically pumped far infrared ring laser

    NASA Astrophysics Data System (ADS)

    Matsushima, Kyoji; Higashida, Noriyoshi; Sokabe, Noburu; Ariyasu, Tomio

    1995-02-01

    An experimental and theoretical investigation has been made on the unidirectional operation of an optically pumped far infrared ring laser. A ring laser operating on the 119 μm line of CH 3OH experiences reversal of output direction in either case of (a) the pump frequency being tuned across the line center of the infrared pump transition or (b) the fir cavity being tuned across the far infrared line center. A model based on two-mode laser theory predicts the output directionality of the optically pumped fir ring laser.

  5. Fissioning uranium plasmas and nuclear-pumped lasers

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.; Thom, K.

    1975-01-01

    Current research into uranium plasmas, gaseous-core (cavity) reactors, and nuclear-pumped lasers is discussed. Basic properties of fissioning uranium plasmas are summarized together with potential space and terrestrial applications of gaseous-core reactors and nuclear-pumped lasers. Conditions for criticality of a uranium plasma are outlined, and it is shown that the nonequilibrium state and the optical thinness of a fissioning plasma can be exploited for the direct conversion of fission fragment energy into coherent light (i.e., for nuclear-pumped lasers). Successful demonstrations of nuclear-pumped lasers are described together with gaseous-fuel reactor experiments using uranium hexafluoride.

  6. High-temperature diode laser pumps for directed energy fiber lasers (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kanskar, Manoj; Bao, Ling; Chen, Zhigang; DeVito, Mark; Dong, Weimin; Grimshaw, Mike P.; Guan, Xinguo; Hemenway, David M.; Martinsen, Robert; Zhang, Jim; Zhang, Shiguo

    2017-05-01

    Kilowatt-class fiber lasers and amplifiers are becoming increasingly important building blocks for power-scaling laser systems in various different architectures for directed energy applications. Currently, state-of-the-art Yb-doped fiber lasers operating near 1060 nm operate with optical-to-optical power-conversion efficiency of about 66%. State-of-the-art fiber-coupled pump diodes near 975 nm operate with about 50% electrical-to-fiber-coupled optical power conversion efficiency at 25C heatsink temperature. Therefore, the total system electrical-to-optical power conversion efficiency is about 33%. As a result, a 50-kW fiber laser will generate 75 kW of heat at the pump module and 25 kW at the fiber laser module with a total waste heat of 100 kW. It is evident that three times as much waste heat is generated at the pump module. While improving the efficiency of the diodes primarily reduces the input power requirement, increasing the operating temperature primarily reduces the size and weight for thermal management systems. We will discuss improvement in diode laser design, thermal resistance of the package as well as improvement in fiber-coupled optical-to-optical efficiency to achieve high efficiency at higher operating temperature. All of these factors have a far-reaching implication in terms of significantly improving the overall SWAP requirements thus enabling DEW-class fiber lasers on airborne and other platforms.

  7. DOE reactor-pumped laser program

    NASA Astrophysics Data System (ADS)

    Felty, James R.; Lipinski, Ronald J.; McArthur, David A.; Pickard, Paul S.

    1994-05-01

    FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing 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%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. A ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night. The compact size and self-contained power also makes an RPL very suitable for ship basing so that power-beaming activities could be situated around the globe. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, wide-area deposition of diamond- like coatings, and 3-D ceramic lithography.

  8. DOE reactor-pumped laser program

    SciTech Connect

    Felty, J.R.; Lipinski, R.J.; McArthur, D.A.; Pickard, P.S.

    1993-12-31

    FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. A ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night. The compact size and self-contained power also makes an RPL very suitable for ship basing so that power-beaming activities could be situated around the globe. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, wide-area deposition of diamond-like coatings, and 3-D ceramic lithography.

  9. Thin-Film Evaporative Cooling for Side-Pumped Laser

    NASA Technical Reports Server (NTRS)

    Stewart, Brian K. (Inventor)

    2010-01-01

    A system and method are provided for cooling a crystal rod of a side-pumped laser. A transparent housing receives the crystal rod therethrough so that an annular gap is defined between the housing and the radial surface of the crystal rod. A fluid coolant is injected into the annular gap such the annular gap is partially filled with the fluid coolant while the radial surface of the crystal rod is wetted as a thin film all along the axial length thereof.

  10. Laser Systems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tunable diode lasers are employed as radiation sources in high resolution infrared spectroscopy to determine spectral characteristics of gaseous compounds. With other laser systems, they are produced by Spectra-Physics, and used to monitor chemical processes, monitor production of quantity halogen lamps, etc. The Laser Analytics Division of Spectra-Physics credits the system's reliability to a program funded by Langley in the 1970s. Company no longer U.S.-owned. 5/22/97

  11. Nuclear pumped laser research at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Russell, G. R.

    1979-01-01

    Using a partially nuclear excited xenon flashlamp to pump an iodine laser, laser pulse shapes were analyzed with and without nuclear flashlamp augmentation. The pulse shapes indicate that the deposition of nuclear energy is equally as effective as electrical energy deposition in producing laser pulse energy output. The amplification of the E-beam pumped CF3I was measured at pressures of several atmospheres. Preliminary data shows that, for a part of the iodine laser pulse, amplification of almost a factor of two is measured. This measurement indicates that the gain in an E-beam pumped CF3I is an order of magnitude greater than in the coaxial laser tube.

  12. An experimental investigation of (UF-235)6 fission nuclear-pumped lasers

    NASA Technical Reports Server (NTRS)

    Miley, G. H.

    1979-01-01

    A UF6 handling system was designed for use in conjunction with the existing nuclear-pumped laser vacuum system at a nuclear reactor laboratory to perform the experiments described above. A modification to separate the gas fill system from the vacuum system and thus greatly reduce its volume is described as well as operating procedures for the first controlled nuclear pumping experiments with UF6 vapor contained in the laser cell.

  13. Femtosecond diode-pumped mode-locked neodymium lasers

    NASA Astrophysics Data System (ADS)

    Kubeček, Václav; Jelínek, Michal; Čech, Miroslav; Vyhlídal, David; Su, Liangbi; Jiang, Dapeng; Ma, Fengkai; Qian, Xiaobo; Wang, Jingya; Xu, Jun

    2016-12-01

    Fluoride-type crystals (CaF2, SrF2) doped with neodymium Nd3+ and codoped with buffer ions for breaking clusters of active ions and increasing fluorescence efficiency, present interesting alternative as laser active media for the diode-pumped mode-locked lasers. In comparison with widely used materials as Nd:YAG or Nd:YVO4, they have broad emission spectra as well as longer fluorescence lifetime, in comparison with Nd:glass, SrF2 and CaF2 have better thermal conductivity. In spite of the fact, that this thermal conductivity decreases with Nd3+ doping concentration, these crystals are alternative for the Nd:glass in subpicosecond mode-locked laser systems. In this paper we review the basic results reported recently on these active materials and in the second part we present our results achieved in low power diode pumped passively mode locked lasers with Nd,La:CaF2 and Nd,Y:SrF2 crystals. The pulses as short as 258 fs at wavelength of 1057 nm were obtained in the first case, while 5 ps long pulses at 1065 nm were generated from the second laser system.

  14. Laser-Pumped Coherent X-Ray FEL

    DTIC Science & Technology

    2008-11-14

    laser field replaces the magnetic wiggler field of a conventional FEL. Depending on the intensity and quality of both the electron beam and pump laser...and Line Width 16 IV. Comparison of Theory with Simulations 17 a) Wiggler based X-Ray FEL 17 b) Laser Pumped X-Ray FEL 18 V. Conclusions 19...FEL) an intense laser field replaces the magnetic wiggler field of a conventional FEL. Depending on the intensity and quality of both the electron

  15. Diode Laser Pumped Alkali Vapor Lasers with Exciplex-Assisted Absorption

    DTIC Science & Technology

    2013-05-14

    ORGANIZATION Emory University, 1515 Dickey Drive, Atlanta, GA 30322 REPORT NUMBER The College of Optics and Photonics, University of Central Florida, 4000...supplies high power pumping system to AFRL. 1S. SUBJECT TERMS High-power lasers, line-narrowed diode lasers, volume Bragg grating, gas phase, OPAL, hybrid...Central Florida, School of Optics/CREOL Michael C. Heaven Department of Chemistry Emory University Atlanta, GA 30322 Multidisciplinary Research

  16. Heat Pumping in Nanomechanical Systems

    NASA Astrophysics Data System (ADS)

    Chamon, Claudio; Mucciolo, Eduardo R.; Arrachea, Liliana; Capaz, Rodrigo B.

    2011-04-01

    We propose using a phonon pumping mechanism to transfer heat from a cold to a hot body using a propagating modulation of the medium connecting the two bodies. This phonon pump can cool nanomechanical systems without the need for active feedback. We compute the lowest temperature that this refrigerator can achieve.

  17. High-power 2-μm diode-pumped Tm:YAG laser

    NASA Astrophysics Data System (ADS)

    Beach, Raymond J.; Sutton, Steven B.; Honea, Eric C.; Skidmore, Jay A.; Emanuel, Mark A.

    1996-03-01

    Using a scalable diode end-pumping technology developed at Lawrence Livermore National Laboratory we have demonstrated a compact Tm:YAG laser capable of generating greater than 50 W of cw 2 micrometer laser output power. The design and operational characteristics of this laser, which was built originally for use in assessing laser surgical techniques, are discussed. The 2 micrometer radiation produced by the 3F4 - 3H6 transition of Tm3+ has many practical applications because it is strongly absorbed by water and also because it is an 'eye-safe' wavelength. The strong absorption of 2 micrometer radiation by water makes this transition a very attractive candidate for performing laser surgical procedures as most tissue types are predominately composed of liquid water. The fact that 2 micrometer radiation is considered 'eye-safe' makes this transition attractive for laser range finding and remote sensing applications where other laser wavelengths could pose a safety hazard. At sufficiently high doping densities, Tm3+ exhibits a beneficial two-for-one quantum pump efficiency enabling well developed AlGaAs laser diode arrays to be used as efficient excitation sources. Many applications requiring 2 micrometer laser radiation such as remote sensing, laser radar, anti sensor, sensor spoofing, and OPO pumping have driven the development of diode pumped all solid state TM3+ laser systems because of their potential for efficiency, compactness, and ruggedness. Here we focus on Tm3+:YAG and the scalable diode end-pumping technology developed at LLNL which enables higher average power operation of diode pumped Tm3+ laser systems than has previously been possible. To date we have demonstrated cw operation of this laser to power levels of 51 W. The end-pumping technology used is the same as was previously used to demonstrate a 100 mJ Q-switched Nd:YLF laser. (Truncated.)

  18. High-power optically pumped semiconductor laser apllications

    NASA Astrophysics Data System (ADS)

    Morioka, S. Brandon

    2011-03-01

    OPS lasers have found applications in various industrial and scientific laser applications due to their power scaling capability, their wide range of emission wavelengths, physical size and their superior reliability. This paper provides an overview of commercially available OPS lasers and the applications in which they are used including biotechnology, medical, holography, Titanium-Sapphire laser pumping, non-lethal defense, forensics, and entertainment.

  19. CO.sub.2 optically pumped distributed feedback diode laser

    DOEpatents

    Rockwood, Stephen D.

    1980-01-01

    A diode laser optically pumped by a CO.sub.2 coherent source. Interference fringes generated by feeding the optical pumping beam against a second beam, periodically alter the reflectivity of the diode medium allowing frequency variation of the output signal by varying the impingent angle of the CO.sub.2 laser beams.

  20. Vanadium-pumped titanium x-ray laser

    DOEpatents

    Nilsen, Joseph

    1992-01-01

    A resonantly photo-pumped x-ray laser (10) is formed of a vanadium (12) and titanium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state neon-like titanium ions (34) are resonantly photo-pumped by line emission from fluorine-like vanadium ions (32).

  1. Vanadium-pumped titanium x-ray laser

    DOEpatents

    Nilsen, J.

    1992-05-26

    A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions. 4 figs.

  2. Optically Pumped Subwavelength Lasers Operated at Room Temperature

    DTIC Science & Technology

    2012-05-06

    REPORT NACHOS Project Final Report_University of Michigan Optically pumped subwavelength lasers operated at room temperature 14. ABSTRACT 16. SECURITY...28-Feb-2011 NACHOS Project Final Report_University of Michigan Optically pumped subwavelength lasers operated at room temperature Report Title

  3. CW YVO4:Er Laser with Resonant Pumping

    NASA Astrophysics Data System (ADS)

    Gorbachenya, K. N.; Kisel, V. E.; Yasukevich, A. S.; Matrosov, V. N.; Tolstik, N. A.; Kuleshov, N. V.

    2015-05-01

    The lasing characteristics of a YVO4:Er laser with resonant pumping in the 1.5-1.6 μm range are studied. Lasing is obtained at λ = 1603 nm with a differential efficiency of up to 61%. YVO4:Er crystals are found to offer promise for use in efficient resonantly (in-band) pumped lasers.

  4. Linewidth-tunable laser diode array for rubidium laser pumping

    SciTech Connect

    Li Zhiyong; Tan Rongqing; Xu Cheng; Li Lin

    2013-02-28

    To optimise the pump source for a high-power diodepumped rubidium vapour laser, we have designed a laser diode array (LDA) with a narrowed and tunable linewidth and an external cavity formed by two volume Bragg gratings (VBGs). Through controlling the temperature differences between the two VBGs, the LDA linewidth, which was 1.8 nm before mounting the two VBGs, was tunable from 100 pm to 0.2 nm, while the output power changed by no more than 4 %. By changing simultaneously the temperature in both VBGs, the centre wavelength in air of the linewidth-tunable LDA was tunable from 779.40 nm to 780.05 nm. (control of laser radiation parameters)

  5. Multireflection pumping concept for miniaturized diode-pumped solid-state lasers.

    PubMed

    Meister, Jörg; Franzen, Rene; Apel, Christian; Gutknecht, Norbert

    2004-11-01

    An innovative pump concept for diode-pumped, solid-state lasers is introduced as an example for an Er:YSGG laser, permitting its miniaturization. Embedded in a multireflective pump cavity, the laser crystal is simultaneously side and end pumped. Specially calculated and shaped deflecting optics distribute the coaxially input pumping light homogeneously over the lateral surface of the crystal, therefore reducing the size of the laser head, including the optical resonator, to a length of 27.5 mm and an outside diameter of 12.5 mm. The differential efficiency achieved is between 8.7% and 24%. The laser emits energy of 15.7 mJ at an absolute efficiency of 9.1% and a repetition rate of 4 Hz.

  6. Thermal management, beam control, and packaging designs for high power diode laser arrays and pump cavity designs for diode laser array pumped rod shaped lasers

    NASA Astrophysics Data System (ADS)

    Chung, Te-Yuan

    Several novel techniques for controlling, managing and utilizing high power diode lasers are described. Low pressure water spray cooling for a high heat flux system is developed and proven to be an ideal cooling method for high power diode laser arrays. In order to enable better thermal and optical performance of diode laser arrays, a new and simple optical element, the beam control prism, is invented. It provides the ability to accomplish beam shaping and beam tilting at the same time. Several low thermal resistance diode packaging designs using beam control prisms are proposed, studied and produced. Two pump cavity designs using a diode laser array to uniformly pump rod shape gain media are also investigated.

  7. Switching model photovoltaic pumping system

    NASA Astrophysics Data System (ADS)

    Anis, Wagdy R.; Abdul-Sadek Nour, M.

    Photovoltaic (PV) pumping systems are widely used due to their simplicity, high reliability and low cost. A directly-coupled PV pumping system is the most reliable and least-cost PV system. The d.c. motor-pump group is not, however, working at its optimum operating point. A battery buffered PV pumping system introduces a battery between the PV array and the d.c. motor-pump group to ensure that the motor-pump group is operating at its optimum point. The size of the battery storage depends on system economics. If the battery is fully charged while solar radiation is available, the battery will discharge through the load while the PV array is disconnected. Hence, a power loss takes place. To overcome the above mentioned difficulty, a switched mode PV pumping is proposed. When solar radiation is available and the battery is fully charged, the battery is disconnected and the d.c. motor-pump group is directly coupled to the PV array. To avoid excessive operating voltage for the motor, a part of the PV array is switched off to reduce the voltage. As a result, the energy loss is significantly eliminated. Detailed analysis of the proposed system shows that the discharged water increases by about 10% when compared with a conventional battery-buffered system. The system transient performance just after the switching moment shows that the system returns to a steady state in short period. The variations in the system parameters lie within 1% of the rated values.

  8. Diode pumped distributed Bragg reflector lasers based on a dye-to-polymer energy transfer blend.

    PubMed

    Vasdekis, A E; Tsiminis, G; Ribierre, J-C; O' Faolain, Liam; Krauss, T F; Turnbull, G A; Samuel, I D W

    2006-10-02

    We report the demonstration of a compact, all-solid-state polymer laser system comprising of a Gallium Nitride (GaN) semiconductor diode laser as the pump source. The polymer laser was configured as a surface emitting, distributed Bragg reflector laser (DBR), based on a novel energy transfer blend of Coumarin 102 and the conjugated polymer poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene). In this configuration, diode pumping was possible both due to the improved quality of the resonators and the improved harvesting of the diode laser light.

  9. High brightness laser systems incorporating advanced laser bars

    NASA Astrophysics Data System (ADS)

    Strohmaier, Stephan; Vethake, Thilo; Gottdiener, Mark; Wunderlin, Jens; Negoita, Viorel; Li, Yufeng; Barnowski, Tobias; Gong, Tim; An, Haiyan; Treusch, Georg

    2013-02-01

    The performance of high power and high brightness systems has been developing and is developing fast. In the multi kW regime both very high spatial and spectral brightness systems are emerging. Also diode laser pumped and direct diode lasers are becoming the standard laser sources for many applications. The pump sources for thin Disk Laser systems at TRUMPF Photonics enabled by high power and efficiency laser bars are becoming a well established standard in the industry with over two thousand 8 kW Disk Laser pumps installed in TruDisk systems at the customer site. These systems have proven to be a robust and reliable industrial tool. A further increase in power and efficiency of the bar can be easily used to scale the TruDisk output power without major changes in the pump source design. This publication will highlight advanced laser systems in the multi kW range for both direct application and solid state laser pumping using specifically tailored diode laser bars for high spatial and/or high spectral brightness. Results using wavelength stabilization techniques suitable for high power CW laser system applications will be presented. These high power and high brightness diode laser systems, fiber coupled or in free space configuration, depending on application or customer need, typically operate in the range of 900 to 1070 nm wavelength.

  10. Long-Lifetime Laser Materials For Effective Diode Pumping

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.

    1991-01-01

    Long quantum lifetimes reduce number of diodes required to pump. Pumping by laser diodes demonstrated with such common Nd laser materials as neodymium:yttrium aluminum garnet (Nd:YAG) and Nd:YLiF4, but such materials as Nd:LaF3, Nd:NaF.9YF3, and possibly Nd:YF3 more useful because of long lifetimes of their upper laser energy levels. Cost effectiveness primary advantage of solid-state laser materials having longer upper-laser-level lifetimes. Because cost of diodes outweighs cost of laser material by perhaps two orders of magnitude, cost reduced significantly.

  11. Temperature dependence of a diode-pumped cryogenic Er:YAG laser.

    PubMed

    Ter-Gabrielyan, Nikolay; Dubinskii, Mark; Newburgh, G Alex; Michael, Arockiasamy; Merkle, Larry D

    2009-04-27

    We report the laser performance of resonantly diode-pumped Er:YAG from liquid nitrogen temperature to above room temperature. Relative to incident pump power, the best performance was observed at approximately 160 K. Spectroscopy and modeling show that this is due primarily to the changing efficiency of diode pump absorption as the absorption lines broaden with temperature. However, the physics of the Er:YAG system indicates that even with arbitrarily narrow pump linewidth the most efficient laser performance should occur at a temperature somewhat above 77 K. The causes of the temperature dependence are at least qualitatively understood.

  12. Development of Tm:fiber laser-pumped Ho:YLF laser

    NASA Astrophysics Data System (ADS)

    Mizutani, Kohei; Ishii, Shoken; Asai, Kazuhiro; Sato, Atsushi

    2016-05-01

    A 2-micron Ho:YLF laser end-pumped by 1.94-micron Tm:fiber laser was developed. A ring resonator oscillator of 3 m length and amplifier system was adopted. The laser was operated at high repetition rates of 200-5000 Hz in room temperature. The amplifier outputs were about 7.4W in CW and more than 6 Win Q-switch operation of repetition rates more than 500 Hz. This laser was developed to be used for coherent wind and CO2 measurements. Then, injection seeding was applied to the ring resonator and single mode laser emission was obtained. The laser was used for Doppler wind lidar measurements and wind profiles were obtained.

  13. Laser-diode-pumped solid-state laser driver at ILE Osaka

    NASA Astrophysics Data System (ADS)

    Yamanaka, Masanobu; Naito, Kenta; Nakatsuka, Masahiro; Nakai, Sadao

    1992-11-01

    Using a conceptual designing technique developed we evaluate the feasibility of laser diode pumped solid state laser systems which have 1OMJ blue output 10 overall efficiency and 10Hz repetition rate with typical solid state laser materials for the reactor driver from both technical and economical points of view. For an economical laser fusion reactor driver the solid state laser materials are required to have the following properties hw/a 40J/cm2 (hco : the laser photon energy a : the stimulated emission cross section) a thermal shock parameter of <=3W/cm a nonlinear index of refraction smaller than --3x1013 esu and a fluorescence lifetime of <=4ms. 1.

  14. Study of a low power dissipation, miniature laser-pumped rubidium frequency standard

    NASA Astrophysics Data System (ADS)

    Liu, Guo-Bin; Zhao, Feng; Gu, Si-Hong

    2009-09-01

    This paper studies a miniature low power consumption laser-pumped atom vapour cell clock scheme. Pumping 87Rb with a vertical cavity surface emitting laser diode pump and locking the laser frequency on a Doppler-broadened spectral line, it records a 5 × 10-11τ-1/2 (τ < 500 s) frequency stability with a table-top system in a primary experiment. The study reveals that the evaluated scheme is at the level of 2.7 watts power consumption, 90 cm3 volume and 10-12τ-1/2 short-term frequency stability.

  15. 25  W/m2 collection efficiency solar-pumped Nd:YAG laser by a heliostat-parabolic mirror system.

    PubMed

    Liang, D; Almeida, J; Vistas, C R

    2016-09-20

    A large aspheric fused silica lens was used to couple efficiently the concentrated solar radiation from the focal zone of a 1.5-m-diameter primary concentrator into a 4-mm-diameter, 35-mm-long Nd:YAG single-crystal rod within a conical pump cavity. Continuous-wave laser power of 29.3 W was measured, attaining 25.0  W/m2 solar laser collection efficiency, corresponding to a 19% increase over the previous record. Its laser beam figure of merit-the ratio between laser power and the product of Mx2, My2 beam quality factors-of 0.01 W is 1.6 times higher than that of a direct tracking solar laser with 30  W/m2 collection efficiency. A strong dependency of solar laser power on laser resonator cavity length was found.

  16. Low threshold solar-pumped iodine laser

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.

    1986-01-01

    Solar-pumped lasing of i-C3F7I and n-C4F9I at lower solar concentrations (170 solar constants) and longer gain lengths than previous solar lasers is demonstrated, with potential application to the lasing needs of space. Two xenon arc solar simulators provide an AM0 spectrum over the 60-cm gain length, and output pulse energies of 70 mJ and an average power of 550 mW are achieved. Low pressure lasing times of 600 ms are reached, and the observed 0.074 percent slope efficiency could approach the 0.2 percent maximum theoretical efficiency. Due to less quenching of I(asterisk), n-C4F9I is found to be a superior lasant to i-C3F7I.

  17. Geometrical Transformation of Linear Diode-Laser Arrays for Longitudinal Pumping of Solid-State Lasers

    DTIC Science & Technology

    1992-05-26

    of Nd:YAG crystal vs incident power from the geometrically transformed laser - diode array. 24 12 TEM00 output power from Nd:YAG laser when pumped by n...MASSACHUSETTS INSTITUTE OF TECHNOLOGY LINCOLN LABORATORY GEOMETRICAL TRANSFORMATION OF LINEAR DIODE - LASER ARRAYS FOR LONGITUDINAL PUMPING OF SOLID-STATE...Photograph of pump spot at the lens focal plane. 22 10 Curvature of the laser - diode array emitting facet. 23 11 TEMOO output power from 1.06 pm transition

  18. Diode-pumped continuous-wave Nd:glass laser

    NASA Technical Reports Server (NTRS)

    Kozlovsky, W. J.; Fan, T. Y.; Byer, R. L.

    1986-01-01

    The paper reports on diode-laser pumping of monolithic Nd:glass laser oscillators. End pumping with a single-stripe diode laser, a threshold of 2.2 mW, and a slope efficiency of 42 percent were observed on a 2-mm-long oscillator with a mode radius of 35 microns. The oscillator generated 2.5 mW of single-ended output power in many axial modes.

  19. 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.

  20. High power CW iodine laser pumped by solar simulator

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Lee, Min H.; Weaver, Willard R.

    1987-01-01

    An iodine photodissociation laser was pumped by a long Ar arc as the solar simulator to produce a 10-W CW output. Continuous lasing for 1 h was achieved with a flow of the laser material n-C3F7I. The 10-W CW output is the highest produced to date and establishes the feasibility of developing a solar-pumped laser for space power transmission.

  1. High-repetition-rate TEM00-mode diode-laser-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Tang, Chun; Yang, ChengLong; Wang, Weimin; Yan, Senlin; Chen, Jingyan

    1998-08-01

    A diode-laser side-pumped E-O Q-switched TEM00 Nd:YAG slab laser that uses a large N.A. cylindrical lens and a thin slab pumping geometry has been investigated. The pumping scheme has the ability to match well the pump beam to the laser's fundamental transverse mode in two axes. Approximately 1.1 times diffraction limited laser beam is obtained. The slope efficiency is 31% and 18.9% at long-pump and Q-switched operation, respectively.

  2. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  3. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.; Lee, Ja H.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  4. Direct nuclear-pumped lasers using the He-3/n,p/H-3 reaction

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Jalufka, N. W.; Hohl, F.

    1978-01-01

    A description is presented of experimental results concerning a specific class of direct nuclear-pumped lasers classified as 'volumetric nuclear lasers'. In the considered laser system a fissioning gas, He-3, is mixed with the lasing gas to form a homogeneous mixture, resulting in uniform volume excitation. In typical volumetric nuclear lasers a fast-burst reactor is used as a source of neutrons which penetrate a polyethylene moderator. Here the fast neutrons are thermalized. After thermalization, neutrons scatter into the laser cell. Nuclear reactions produce a proton of 0.56 MeV and a tritium ion of 0.19. These ions produce secondary electrons which pump the laser medium creating a population inversion. The results reported demonstrate direct nuclear pumping of He-3-Ar, Xe, Kr, and Cl with the considered system.

  5. High brightness diode-pumped organic solid-state laser

    SciTech Connect

    Zhao, Zhuang; Mhibik, Oussama; Nafa, Malik; Chénais, Sébastien; Forget, Sébastien

    2015-02-02

    High-power, diffraction-limited organic solid-state laser operation has been achieved in a vertical external cavity surface-emitting organic laser (VECSOL), pumped by a low-cost compact blue laser diode. The diode-pumped VECSOLs were demonstrated with various dyes in a polymer matrix, leading to laser emissions from 540 nm to 660 nm. Optimization of both the pump pulse duration and output coupling leads to a pump slope efficiency of 11% for a DCM based VECSOLs. We report output pulse energy up to 280 nJ with 100 ns long pump pulses, leading to a peak power of 3.5 W in a circularly symmetric, diffraction-limited beam.

  6. Pump control system for windmills

    SciTech Connect

    Avery, D.E.

    1983-07-12

    A windmill control system is disclosed having lever means, for varying length of stroke of the pump piston, and a control means, responsive to the velocity of the wind to operate the lever means to vary the length of stroke and hence the effective displacement of the pump in accordance with available wind energy, with the control means having a sensing member separate from the windmill disposed in the wind and displaceable thereby in accordance with wind velocity.

  7. Pump control system for windmills

    SciTech Connect

    Avery, Don E.

    1983-01-01

    A windmill control system having lever means, for varying length of stroke of the pump piston, and a control means, responsive to the velocity of the wind to operate the lever means to vary the length of stroke and hence the effective displacement of the pump in accordance with available wind energy, with the control means having a sensing member separate from the windmill disposed in the wind and displaceable thereby in accordance with wind velocity.

  8. DPSS Laser Beam Quality Optimization Through Pump Current Tuning

    SciTech Connect

    Omohundro, Rob; Callen, Alice; Sukuta, Sydney; /San Jose City Coll.

    2012-03-30

    The goal of this study is to demonstrate how a DPSS laser beam's quality parameters can be simultaneously optimized through pump current tuning. Two DPSS lasers of the same make and model were used where the laser diode pump current was first varied to ascertain the lowest RMS noise region. The lowest noise was found to be 0.13% in this region and the best M{sup 2} value of 1.0 and highest laser output power were simultaneously attained at the same current point. The laser manufacturer reported a M{sup 2} value of 1.3 and RMS noise value of .14% for these lasers. This study therefore demonstrates that pump current tuning a DPSS laser can simultaneously optimize RMS Noise, Power and M{sup 2} values. Future studies will strive to broaden the scope of the beam quality parameters impacted by current tuning.

  9. Pump system characterization and reliability enhancement

    SciTech Connect

    Staunton, R.H.

    1997-09-01

    Pump characterization studies were performed at the Oak Ridge National Laboratory (ORNL) to review and analyze six years (1990 to 1995) of data from pump systems at domestic nuclear plants. The studies considered not only pumps and pump motors but also pump related circuit breakers and turbine drives (i.e., the pump system). One significant finding was that the number of significant failures of the pump circuit breaker exceeds the number of significant failures of the pump itself. The study also shows how regulatory code testing was designed for the pump only and therefore did not lead to the discovery of other significant pump system failures. Potential diagnostic technologies both experimental and mature, suitable for on-line and off-line pump testing were identified. The study does not select or recommend technologies but proposes diagnostic technologies and monitoring techniques that should be further evaluated/developed for making meaningful and critically needed improvements in the reliability of the pump system.

  10. Experimental and theoretical study of the performance of optically pumped cesium vapor laser as a function of the pump-to-laser beam overlap

    NASA Astrophysics Data System (ADS)

    Barmashenko, Boris D.; Cohen, Tom; Lebiush, Eyal; Auslender, Ilya; Rosenwaks, Salman

    2016-10-01

    We report on the results of an experimental study of Ti:Sapphire pumped Cs laser and theoretical modeling of these results, where we focused on the influence of the pump-to-laser beam overlap, a crucial parameter for optimizing the output laser power. Non monotonic dependence of the laser power (optimized over the temperature) on the pump beam radius was observed with a maximum achieved at the ratio 0.7 between the pump and laser beam radii. The optimal temperature decreased with increasing pump beam radius. Maximum laser power > 370 mW with an optical-to-optical efficiency of 43% and slope efficiency 55% was obtained. A simple optical model of the laser, where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams were assumed, was compared to the experiments. Good agreement was obtained between the measured and calculated dependence of the laser power on the pump power at different pump beam radii and also of the laser power, threshold pump power and optimal temperature on the pump beam radius. The model does not use empirical parameters such as mode overlap efficiency but rather the pump and laser beam spatial shapes as input parameters. The present results combined with results of the application of the model to K DPAL and Ti:Sapphire pumped Cs laser, indicate that the model can describe the operation of different optically pumped alkali lasers with arbitrary spatial distributions of the pump and laser beam widths.

  11. Wave optics simulation of diode pumped alkali laser (DPAL)

    NASA Astrophysics Data System (ADS)

    Endo, Masamori; Nagaoka, Ryuji; Nagaoka, Hiroki; Nagai, Toru; Wani, Fumio

    2016-03-01

    A numerical simulation code for a diode pumped alkali laser (DPAL) was developed. The code employs the Fresnel- Kirchhoff diffraction integral for both laser mode and pump light propagations. A three-dimensional rate equation set was developed to determine the local gain. The spectral divergence of the pump beam was represented by a series of monochromatic beams with different wavelengths. The calculated results showed an excellent agreements with relevant experimental results. It was found that the main channel of the pump power drain is the spontaneous emission from the upper level of the lasing transition.

  12. Method and apparatus for efficient operation of optically pumped laser

    NASA Technical Reports Server (NTRS)

    Sipes, Jr., Donald L. (Inventor)

    1987-01-01

    An optically pumped single mode laser, e.g., Nd:YAG crystal (20) with planoconcave mirrors is increased in efficiency by an order of magnitude to about 8% by optics (25, 27) for focusing the high power multimode output of laser diode arrays (21, 22) into the mode volume (20') of the laser medium (20). A plurality of these optically pumped single mode lasers (1-4) may be cascaded in a ring with dichroic mirrors (M.sub.1 -M.sub.4) at the corners for coupling in the laser diode arrays, each having its own means for spatially tailoring its beam to concentrate pump distribution inside the lasing mode volume of the medium. An InGaAlAs pump diode (30) with its wavelength the same as the lasing medium makes the ring unidirectional.

  13. Tm,Ho:YLF laser end-pumped by a semiconductor diode laser array

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid (Inventor)

    1990-01-01

    An Ho:YLF crystal including Tm as sensitizers for the activator Ho, is optically pumped with a semiconductor diode laser array to generate 2.1 micron radiation with a pump power to output power of efficiency as high as 68 percent. The prior-art dual sensitizer system of Er and Tm requires cooling, such as by LN2, but by using Tm alone and decreasing the concentrations of Tm and Ho, and decreasing the length of the laser rod to about 1 cm, it has been demonstrated that laser operation can be obtained from a temperature of 77 K with an efficiency as high as 68 percent up to ambient room temperature with an efficiency at that temperature as high as 9 percent.

  14. Highly efficient multimode diode-pumped Yb:KYW laser

    NASA Astrophysics Data System (ADS)

    Kuznetsov, S. A.; Pivtsov, V. S.; Semenko, A. V.; Bagayev, S. N.

    2017-01-01

    Record high differential efficiency (53.2%) and full optical efficiency (48%) for a multimode diode-pumped Yb:KYW laser have been achieved. The characteristics of the laser and methods for improving its efficiency using a distributed Bragg reflector tapered diode laser (DBR TDL) are discussed.

  15. Ignition experiment design based on γ-pumping gas lasers

    NASA Astrophysics Data System (ADS)

    Bonyushkin, E. K.; Il'kaev, R. I.; Morovov, A. P.; Pavlovskii, A. I.; Lazhintsev, B. V.; Basov, N.; Gus'kov, S. Yu.; Rosanov, V. B.; Zmitrenko, N. V.

    1996-05-01

    Comparative analysis of gas lasers pumped by γ-radiation for ignition experiment is carried out. The possibilities of frequency-time pulse shaping are discussed for these kinds of laser drivers. New type of ICF target (LIGHT-target), which is able to provide an uniform deposition of laser driver energy is proposed as a target for ignition experiment.

  16. Compact, passively Q-switched, all-solid-state master oscillator-power amplifier-optical parametric oscillator (MOPA-OPO) system pumped by a fiber-coupled diode laser generating high-brightness, tunable, ultraviolet radiation.

    PubMed

    Peuser, Peter; Platz, Willi; Fix, Andreas; Ehret, Gerhard; Meister, Alexander; Haag, Matthias; Zolichowski, Paul

    2009-07-01

    We report on a compact, tunable ultraviolet laser system that consists of an optical parametric oscillator (OPO) and a longitudinally diode-pumped Nd:YAG master oscillator-power amplifier (MOPA). The pump energy for the whole laser system is supplied via a single delivery fiber. Nanosecond pulses are produced by an oscillator that is passively Q-switched by a Cr(4+):YAG crystal. The OPO is pumped by the second harmonic of the Nd:YAG MOPA. Continuously tunable radiation is generated by an intracavity sum-frequency mixing process within the OPO in the range of 245-260 nm with high beam quality. Maximum pulse energies of 1.2 mJ were achieved, which correspond to an optical efficiency of 3.75%, relating to the pulse energy of the MOPA at 1064 nm.

  17. Theoretical model and simulations for a cw exciplex pumped alkali laser.

    PubMed

    Huang, Wei; Tan, Rongqing; Li, Zhiyong; Lu, Xiaochuan

    2015-12-14

    The Exciplex Pumped Alkali Laser (XPAL) system, which is similar to DPAL (Diode Pumped Alkali vapor Laser), has been demonstrated in mixtures of Cs vapor, Ar, with and without ethane. Unlike DPAL, it uses the broadband absorption blue satellite of the alkali D2 line, created by naturally occuring collision pairs. For example, Cs-Ar collision pairs have an absorption width which is as wide as the one of commercial semiconductor diode lasers. A continuous wave XPAL four-level theoretical model is presented in this paper. More factors are considered, such as the spectral dependence of pumped laser absorption for broadband pumping and the longitudinal population variation. Some intra-cavity details, such as longitudinal distributions of pumped laser and alkali laser, can also be solved well. The predictions of optical-to-optical efficiency as a function of temperature and pumped laser intensity are presented. The model predicts that there is an optimum value of temperature or pumped laser intensity. The analysis of the influence of cell length on optical-to-optical efficiency shows that a better performance can be achieved when using longer cell. The prediction of influence of Ar concentration and reflectivity of output coupler shows that higher optical-to-optical efficiency could be achieved if lower reflectivity of output coupler and higher Ar concentration are used. The optical-to-optical efficiency as high as 84% achieved by optimizing configuration with the pumped intensity of 5 × 10⁷ W/cm² presented shows that broadband pumped four-level XPAL system has a potential of high optical-to-optical efficiency.

  18. 250W diode laser for low pressure Rb vapor pumping

    NASA Astrophysics Data System (ADS)

    Podvyaznyy, A.; Venus, G.; Smirnov, V.; Mokhun, O.; Koulechov, V.; Hostutler, D.; Glebov, L.

    2010-02-01

    The diode pumped alkali vapor lasers operating at subatmospheric pressure require developing of a new generation of high-power laser diode sources with about 10 GHz wide emission spectrum. The latest achievements in the technology of volume Bragg gratings (VBGs) recorded in photo-thermo-refractive glass opened new opportunities for the design and fabrication of compact external cavity laser diodes, diode bars and stacks with reflecting VBGs as output couplers. We present a diode laser system providing up to 250 W output power and emission spectral width of 20 pm (FWHM) at the wavelength of 780 nm. The stability and position of an emission wavelength is determined by the resonant wavelength of a VBG which is controlled by temperature. Stability of an emitting wavelength is within 5 pm. Thermal tuning of the wavelength provides maximum overlapping of emitting line with absorption spectrum of a Rb (rubidium)- cell. The designed system consists of 7 modules tuned to the same wavelength corresponding to D2 spectral line of Rb87 or Rb85 and coupled to a single output fiber. Analogous systems could be used for other Rb isotopes spectral lines as well as for lasers based on other alkali metal vapors (Cs and K) or any agents with narrow absorption lines.

  19. Temperature Gradients In Diode-pumped Alkali Lasers

    DTIC Science & Technology

    2012-01-18

    radiation from bars or stacks of diode lasers is absorbed by atomic potassium, rubidium , or cesium. Collision-induced energy transfer populates the upper...laser level, and lasing is achieved in the near-IR on the D1 (pump) line. A rubidium laser pumped by a 1.28kW diode stack with a 0.35nm spectral band...negligible, offering the potential for low waste heat loads. However, cycling of atoms by the pump beam can be >109photons/ atom -s. The energy of the spin

  20. Direct solar pumping of semiconductor lasers: A feasibility study

    NASA Technical Reports Server (NTRS)

    Anderson, Neal G.

    1992-01-01

    This report describes results of NASA Grant NAG-1-1148, entitled Direct Solar Pumping of Semiconductor Lasers: A Feasibility Study. The goals of this study were to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space with directly focused sunlight and to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or storage battery electrically pumping a current injection laser. With external modulation, such lasers could perhaps be efficient sources for intersatellite communications. We proposed specifically to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation at low pump intensities. These tasks have been accomplished, as described in this report of our completed project. The report is organized as follows: Some general considerations relevant to the solar-pumped semiconductor laser problem are discussed in Section 2, and the types of structures chosen for specific investigation are described. The details of the laser model we developed for this work are then outlined in Section 3. In Section 4, results of our study are presented, including designs for optimum lattice-matched and strained-layer solar-pumped quantum-well lasers and threshold pumping estimates for these structures. It was hoped at the outset of this work that structures could be identified which could be expected to operate continuously at solar photoexcitation intensities of several thousand suns, and this indeed turned out to be the case as described in this section. Our project is

  1. TEM00 mode Nd:YAG solar laser by side-pumping a grooved rod

    NASA Astrophysics Data System (ADS)

    Vistas, Cláudia R.; Liang, Dawei; Almeida, Joana; Guillot, Emmanuel

    2016-05-01

    A simple TEM00 mode solar laser system with a grooved Nd:YAG rod pumped through a heliostat-parabolic mirror system is reported here. The radiation coupling capacity of a fused silica tube lens was combined with the multipass pumping ability of a 2 V-shaped cavity to provide efficient side-pumping along a 4.0 mm diameter grooved Nd:YAG single-crystal rod. TEM00 mode solar laser power of 3.4 W was measured by adopting an asymmetric large-mode laser resonant cavity. Record TEM00 mode solar laser collection efficiency of 3.4 W/m2and slope efficiency of 1.9% was achieved, which corresponds to 1.8 and 2.4 times more than the previous TEM00 mode Nd:YAG solar laser using the PROMES-CNRS heliostat-parabolic mirror system, respectively.

  2. 100W high-brightness multi-emitter laser pump

    NASA Astrophysics Data System (ADS)

    Duesterberg, Richard; Xu, Lei; Skidmore, Jay A.; Guo, James; Cheng, Jane; Du, Jihua; Johnson, Brad; Vecht, David L.; Guerin, Nicolas; Huang, Benlih; Yin, Dongliang; Cheng, Peter; Raju, Reddy; Lee, Kong Weng; Cai, Jason; Rossin, Victor; Zucker, Erik P.

    2011-03-01

    We report results of a spatially-multiplexed broad area laser diode platform designed for efficient pumping of fiber lasers or direct-diode systems. Optical output power in excess of 100W from a 105μm core, 0.15NA fiber is demonstrated with high coupling efficiency. The compact form factor and low thermal resistance enable tight packing densities needed for kW-class fiber laser systems. Broad area laser diodes have been optimized to reduce near- and far-field performance and prevent blooming without sacrificing other electro-optic parameters. With proper lens optimization this produces ~5% increase in coupling / wall plug efficiency for our design. In addition to performance characteristics, an update on long term reliability testing of 9XX nm broad area laser diode is provided that continues to show no wear out under high acceleration. Under nominal operating conditions of 12W ex-facet power at 25C, the diode mean time to failure (MTTF) is forecast to be ~ 480 kh.

  3. Optimising the efficiency of pulsed diode pumped Yb:YAG laser amplifiers for ns pulse generation.

    PubMed

    Ertel, K; Banerjee, S; Mason, P D; Phillips, P J; Siebold, M; Hernandez-Gomez, C; Collier, J C

    2011-12-19

    We present a numerical model of a pulsed, diode-pumped Yb:YAG laser amplifier for the generation of high energy ns-pulses. This model is used to explore how optical-to-optical efficiency depends on factors such as pump duration, pump spectrum, pump intensity, doping concentration, and operating temperature. We put special emphasis on finding ways to achieve high efficiency within the practical limitations imposed by real-world laser systems, such as limited pump brightness and limited damage fluence. We show that a particularly advantageous way of improving efficiency within those constraints is operation at cryogenic temperature. Based on the numerical findings we present a concept for a scalable amplifier based on an end-pumped, cryogenic, gas-cooled multi-slab architecture.

  4. Recombination-pumped triatomic hydrogen infrared lasers

    NASA Astrophysics Data System (ADS)

    Saykally, R. J.; Michael, E. A.; Wang, J.; Greene, Chris H.

    2010-12-01

    Mid-infrared laser lines observed in hydrogen/rare gas discharges are assigned to three-body recombination processes involving an electron, a rare gas (He or Ne) atom, and the triatomic hydrogen ion (H3+). Calculations of radiative transitions between neutral H3 Rydberg states support this interpretation, and link it to recent results for hydrogenic/rare gas afterglow plasmas. A mechanism for the population inversion is proposed, and the potential generality and astrophysical implications of such molecular recombination laser systems are briefly discussed.

  5. Traveling wave pumping of ultra-short pulse x-ray lasers

    SciTech Connect

    Snavely, R.A.; Da Silva, L.B.; Eder, D.C.; Matthews, D.L.; Moon, S.J.

    1997-11-10

    Pumping of proposed inner-shell photo-ionized (ISPI) x-ray lasers places stringent requirements on the optical pump source. We investigate these requirements for an example x-ray laser (XRL) in Carbon lasing on the 2p-1s transition at 45 A. Competing with this lasing transition is the very fast Auger decay rate out of the upper lasing state, such that the x-ray laser would self-terminate on a femto- second time scale. XRL gain may be demonstrated if pump energy is delivered in a time short when compared to the Auger rate. The fast self-termination also demands that we sequentially pump the length of the x-ray laser at the group velocity of the x-ray laser. This is the classical traveling wave requirement. It imposes a condition on the pumping source that the phase angle of the pump laser be precisely de- coupled from the pulse front angle. At high light intensities, this must be performed with a vacuum grating delay line. We will also include a discussion of issues related to pump energy delivery, i.e. pulse-front curvature, temporal blurring and puke fidelity. An all- reflective optical system with low aberration is investigated to see if it fulfills the requirements. It is expected that these designs together with new high energy (>1J) ultra-short pulse (< 40 fs) pump lasers now under construction may fulfill our pump energy conditions and produce a tabletop x-ray laser.

  6. Nuclear-pumped lasers for large-scale applications

    SciTech Connect

    Anderson, R.E.; Leonard, E.M.; Shea, R.E.; Berggren, R.R.

    1988-01-01

    Efficient initiation of large-volume chemical lasers may be achieved by neutron induced reactions which produce charged particles in the final state. When a burst mode nuclear reactor is used as the neutron source, both a sufficiently intense neutron flux and a sufficient short initiation pulse may be possible. Proof-of-principle experiments are planned to demonstrate lasing in a direct nuclear-pumped large-volume system: to study the effects of various neutron absorbing materials on laser performance; to study the effects of long initiation pulse lengths; to determine the performance of large-scale optics and the beam quality that may bo obtained; and to assess the performance of alternative designs of burst systems that increase the neutron output and burst repetition rate. 21 refs., 7 figs., 5 tabs.

  7. Passive apparatus for stabilizing a flashlamp-pumped dye laser

    SciTech Connect

    De Wilde, M.A.; Decker, L.J.

    1986-04-29

    A flash lamp pumped, dye laser apparatus is described which consists of a flash lamp and a liquid dye solution in a transparent compartment proximate to the flash lamp. The compartment is also connected to a tubular circulatory system for moving the liquid dye. The dye solution is activated by flashing of the lamp for lasing to emit light, the lamp and compartment enclosed in a cooling first water jacket, the jacket enclosing deionized water for cooling, an improved cooling system wherein the temperature of the deionized water and the liquid dye solution are maintained within 0.5/sup 0/C of one another, enabling the laser for pulsing at a stabilized 10 pulses per second rate.

  8. Heat generation and thermo-mechanical effect modeling in longitudinally diode-pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Lakhdari, Fouad; Osmani, Ismahen; Tabet, Saida

    2015-09-01

    Thermal management in solid state laser is a challenge to the high power laser industry's ability to provide continued improvements in device and system performance. In this work an investigation of heat generation and thermo-mechanical effect in a high-power Nd:YAG and Yb:YAG cylindrical-type solid state laser pumped longitudinally with different power by fibre coupled laser diode is carried out by numerical simulation based on the finite element method (FEM). Impact of the dopant concentration on the power conversion efficiency is included in the simulation. The distribution of the temperature inside the lasing material is resolute according to the thermal conductivity. The thermo-mechanical effect is explored as a function of pump power in order to determine the maximum pumping power allowed to prevent the crystal's fracture. The presented simulations are in broad agreement with analytical solutions; provided that the boundary condition of the pump induced heat generation is accurately modelled.

  9. Reversing the pump dependence of a laser at an exceptional point

    PubMed Central

    Brandstetter, M.; Liertzer, M.; Deutsch, C.; Klang, P.; Schöberl, J.; Türeci, H. E.; Strasser, G.; Unterrainer, K.; Rotter, S.

    2014-01-01

    When two resonant modes in a system with gain or loss coalesce in both their resonance position and their width, a so-called exceptional point occurs, which acts as a source of non-trivial physics in a diverse range of systems. Lasers provide a natural setting to study such non-Hermitian degeneracies, as they feature resonant modes and a gain material as their basic constituents. Here we show that exceptional points can be conveniently induced in a photonic molecule laser by a suitable variation of the applied pump. Using a pair of coupled microdisk quantum cascade lasers, we demonstrate that in the vicinity of these exceptional points the coupled laser shows a characteristic reversal of its pump dependence, including a strongly decreasing intensity of the emitted laser light for increasing pump power. PMID:24925314

  10. Theoretical studies of solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1983-01-01

    Possible types of lasers were surveyed for solar power conversion. The types considered were (1) liquid dye lasers, (2) vapor dye lasers, and (3) nondissociative molecular lasers. These are discussed.

  11. Analysis of the pump-beam path in corner-pumped slab laser

    SciTech Connect

    Chen Li; Qiang Liu; Mali Gong; Gang Chen; Ping Yan

    2007-06-30

    The propagation of the pump radiation in active slab elements is considered. Conditions of the total internal reflection of the pump radiation are obtained, and are used to construct a series of graphical illustrations of reflection characteristics of different active elements. (control of laser radiation parameters)

  12. Thulium:ZBLAN blue fiber laser pumped by two wavelengths

    NASA Astrophysics Data System (ADS)

    Tohmon, Genji; Sato, Hisanao; Ohya, Jun; Uno, Tomoaki

    1997-05-01

    We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 m with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649- m light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48- m output characteristics as a function of fiber length and output reflectivity.

  13. Thulium:ZBLAN blue fiber laser pumped by two wavelengths.

    PubMed

    Tohmon, G; Sato, H; Ohya, J; Uno, T

    1997-05-20

    We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 mum with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649-mum light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48-mum output characteristics as a function of fiber length and output reflectivity.

  14. Stabilizing an atom laser using spatially selective pumping and feedback

    SciTech Connect

    Johnsson, Mattias; Haine, Simon; Hope, Joseph J.

    2005-11-15

    We perform a comprehensive study of stability of a pumped atom laser in the presence of pumping, damping, and outcoupling. We also introduce a realistic feedback scheme to improve stability by extracting energy from the condensate and determine its effectiveness. We find that while the feedback scheme is highly efficient in reducing condensate fluctuations, it usually does not alter the stability class of a particular set of pumping, damping, and outcoupling parameters.

  15. 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.

  16. Picosecond holmium fibre laser pumped at 1125 \\ {\\text{nm}}

    NASA Astrophysics Data System (ADS)

    Kamynin, V. A.; Filatova, S. A.; Zhluktova, I. V.; Tsvetkov, V. B.

    2016-12-01

    We report a passively mode-locked, all-fibre holmium laser based on nonlinear polarisation rotation. As a pump source use is made of an 1125-{\\text{nm}} ytterbium-doped fibre laser. The pulse repetition rate of the holmium laser is 7.5 {\\text{MHz}}, and the pulse duration does not exceed 52 {\\text{ps}} at wavelengths of 2065 and 2080 {\\text{nm}}. The average laser output power reaches 5 {\\text{mW}}.

  17. The LASL program in nuclear pumped liquid lasers

    NASA Technical Reports Server (NTRS)

    Mansfield, C. R.; Bird, P. F.; Davis, J. F.

    1979-01-01

    The development of nuclear-pumped, liquid-based lanthanide ion lasers is discussed. Early investigations of lanthanide ion lasers have lead to solid-state and gaseous neodymium lasers, and a demonstration of lasing in the liquid state. Solvents containing organic chelating agents have been employed in liquid Eu(+3) and Tb(+3) lasers to extend fluorescence lifetimes, however aprotic solvents have been found to enable the development of large-scale liquid lasers. The advantages to be gained from high-power nuclear-pumped lasers based on lanthanide solutions include the high density of fissile materials possible, and a nuclear pumping cell which can operate in either a nuclear or optical pumping mode is being fabricated at the Los Alamos Scientific Laboratory to investigate the nuclear pumping of liquid lanthanide ion lasers. Areas that need exploration before specific laser design features can be considered include energy channeling within the liquid upon excitation, radiation damage due to solvent dissociation, and reactor technology for the development of a self-critical liquid reactor.

  18. A 1 kHz A-scan rate pump-probe laser-ultrasound system for robust inspection of composites.

    PubMed

    Pelivanov, Ivan; Shtokolov, Alex; Wei, Chen-Wei; O'Donnell, Matthew

    2015-09-01

    We recently built a fiber-optic laser-ultrasound (LU) scanner for nondestructive evaluation (NDE) of aircraft composites and demonstrated its greatly improved sensitivity and stability compared with current noncontact systems. It is also very attractive in terms of cost, stability to environmental noise and surface roughness, simplicity in adjustment, footprint, and flexibility. A new type of a balanced fiber-optic Sagnac interferometer is a key component of this all-optical LU pump-probe system. Very high A-scan rates can be achieved because no reference arm or stabilization feedback are needed. Here, we demonstrate LU system performance at 1000 A-scans/s combined with a fast 2-D translator operating at a scanning speed of 100 mm/s with a peak acceleration of 10 m/s(2) in both lateral directions to produce parallel B-scans at high rates. The fast scanning strategy is described in detail. The sensitivity of this system, in terms of noise equivalent pressure, was further improved to be only 8.3 dB above the Nyquist thermal noise limit. To our knowledge, this is the best reported sensitivity for a noncontact ultrasonic detector of this dimension used to inspect aircraft composites.

  19. Nuclear pumped lasers: Advantages of O2 (1 delta)

    NASA Technical Reports Server (NTRS)

    Taylor, J. J.

    1979-01-01

    Nuclear pumped laser technology was evaluated as a possible future weapons contender. It was determined that in order to become a primary weapon the following engineering problems must be solved: shielding, heat dissipation, high efficiency fixed focus pumping, good beam quality, and thermal blooming.

  20. Nuclear pumped lasers: Advantages of O2 (1 delta)

    NASA Technical Reports Server (NTRS)

    Taylor, J. J.

    1979-01-01

    Nuclear pumped laser technology was evaluated as a possible future weapons contender. It was determined that in order to become a primary weapon the following engineering problems must be solved: shielding, heat dissipation, high efficiency fixed focus pumping, good beam quality, and thermal blooming.

  1. Proposed Nuclear Pumped Laser Experiments Utilizing Gamma-Rays.

    DTIC Science & Technology

    1980-02-25

    geometrica factor. The geometrical factor was derived in 21 geometry. The probability of a photon born in the LXe intersecting the laser tube is e - . 2wr dr...the absorbing media is pumped by a slowly rising pump, the excitation is rapidly degraded due to spontaneous emission and quenching processes. If the

  2. Quantum mechanical features of optically pumped CW FIR lasers

    NASA Technical Reports Server (NTRS)

    Seligson, D.; Leite, J. R. R.; Sanchez, A.; Feld, M. S.; Ducloy, M.

    1977-01-01

    Quantum mechanical predictions for the gain of an optically pumped CW FIR laser are presented for cases in which one or both of the pump and FIR transitions are pressure or Doppler broadened. The results are compared to those based on the rate equation model. Some of the quantum mechanical predictions are verified in CH3OH.

  3. Athermal diode-pumped laser designator modules for targeting application

    NASA Astrophysics Data System (ADS)

    Crepy, B.; Closse, G.; Da Cruz, J.; Sabourdy, D.; Montagne, J.; Nguyen, L.

    2012-10-01

    We report on the development and characteristics of athermal diode-pumped designator modules as Original Equipment Manufacturer (OEM) for targeting application. These modules are designed with the latest diode-pumped technology minimizing volume and power consumption. The core technology allows to address multi-platforms requirements such as land or airborne. Products are composed of a Laser Transmitter Unit (LTU) and Laser Electronic Unit (LEU) for modular approach.

  4. Modeling of diode pumped metastable rare gas lasers.

    PubMed

    Yang, Zining; Yu, Guangqi; Wang, Hongyan; Lu, Qisheng; Xu, Xiaojun

    2015-06-01

    As a new kind of optically pumped gaseous lasers, diode pumped metastable rare gas lasers (OPRGLs) show potential in high power operation. In this paper, a multi-level rate equation based model of OPRGL is established. A qualitative agreement between simulation and Rawlins et al.'s experimental result shows the validity of the model. The key parameters' influences and energy distribution characteristics are theoretically studied, which is useful for the optimized design of high efficient OPRGLs.

  5. Efficient potassium diode pumped alkali laser operating in pulsed mode.

    PubMed

    Zhdanov, Boris V; Rotondaro, Matthew D; Shaffer, Michael K; Knize, Randall J

    2014-07-14

    This paper presents the results of our experiments on the development of an efficient hydrocarbon free diode pumped alkali laser based on potassium vapor buffered by He gas at 600 Torr. A slope efficiency of more than 50% was demonstrated with a total optical conversion efficiency of 30%. This result was achieved by using a narrowband diode laser stack as the pump source. The stack was operated in pulsed mode to avoid limiting thermal effects and ionization.

  6. Tunable, diode side-pumped Er:YAG laser

    DOEpatents

    Hamilton, C.E.; Furu, L.H.

    1997-04-22

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 {micro}m, and is tunable over a 6 nm range near about 2.936 {micro}m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 {micro}m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 {micro}m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems. 4 figs.

  7. Tunable, diode side-pumped Er: YAG laser

    DOEpatents

    Hamilton, Charles E.; Furu, Laurence H.

    1997-01-01

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 .mu.m, and is tunable over a 6 nm range near about 2.936 .mu.m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 .mu.m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 .mu.m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems.

  8. Thermal effects of pulsed pumping in semiconductor disk lasers

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Dai, Teli; Liang, Yiping; Fan, Siqiang; Zhang, Yu

    2012-11-01

    It has been demonstrated experimentally that pulsed pumping can significantly improve the thermal management in an optically-pumped semiconductor disk laser, and the output power of semiconductor disk lasers under pulsed pumping can be upgraded to times of those under continuous pumping. This paper presents numerical analysis of the thermal effects of pulsed pumping in semiconductor disk lasers, so to theoretically disclose the details of the thermal processes of pulsed pumping. In the simulation, the parabolic heat conduction equation, which is widely employed to describe the transient thermal transfer processes, is solved under cylindrical coordinates by the use of the finite element method, a periodic pump pulses train is assumed, and the maximum temperature rise in the multiple quantum wells active region is focused. The influences of the duty cycle, the repetition rate, and the pulse width of the pump pulses on the maximum temperature rise are investigated, and the results are compared with the case of continuous-wave pumping. Some simulation results are compared with reported data, and the theoretical results are in good agreement with the experiments.

  9. Nuclear pumping of a neutral carbon laser

    NASA Technical Reports Server (NTRS)

    Prelas, M. A.; Anderson, J. H.; Boody, F. P.; Nagalingam, S. J. S.; Miley, G. H.

    1978-01-01

    Nuclear pumped lasing on the neutral carbon line at 1.45 micron was achieved in mixtures of He-CO, He-N2-CO, He-CO2, and Ne-CO and Ne-CO2. A minimum thermal neutron flux of 2 x 10 to the 14th power sq cm-sec was sufficient for oscillation in the helium mixtures. The peak of the laser output was delayed up to 5.5 ms relative to the neutron pulse in He-CO2, He-N2-CO, Ne-CO, and Ne-CO2 mixtures while no delay was observed in He-CO mixtures. Lasing was obtained with helium pressures from 20 to 800 T, Ne pressures from 100 to 200 T, CO from 0.25 to 20 mT, N2 from 0.5 mT, and CO2 from 0.1 to 25 mT in the respective mixtures.

  10. Remote chemical sensing by laser optical pumping

    SciTech Connect

    Stevens, C.G.; Magnotta, F.

    1996-08-01

    We are exploring a new approach to remote chemical identification that promises higher precision than can be achieved by conventional DIAL approaches. This technique also addresses and potentially solves the problem of detecting a target gas in the presence of an interfering gas or gases. This new approach utilizes an eye-safe infrared optical pumping pulse to deplete the population of a specific rotational level(s) and then sends probe pulses at the same or different wavelengths to interrogate the bleaching of the absorption. We have experimentally measured optical saturation fluence level at atmospheric pressure for HCl, and find this level to be {approximately}1 mJ/cm{sup 2}, significantly below eye-safe limits in agreement with calculations. Calculations have been performed on other molecules of interest with similar results. In the laboratory, using time-delay-replicated pulses at a single frequency we have made absorption measurements with precision levels routinely approaching 0.1% after averaging 200 laser pulses. These results as well as those of two other pulse experiments will be presented. 5 refs., 9 figs., 1 tab.

  11. Large area electron beam pumped krypton fluoride laser amplifier

    SciTech Connect

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

    1997-06-01

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

  12. Stable 811.53 nm diode laser pump source for optically pumped metastable Ar laser

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Zuo, Duluo; Zhao, Jun; Li, Bin; Yu, Anlan; Wang, Xinbing

    2016-10-01

    A stable external cavity diode laser coupled with volume Bragg grating for metastable argon atoms pumping is presented. The measured maximum output power of the continuous wave is 6.5 W when the spectral width (FWHM) is less than 21 pm around 811.53 nm and the power efficiency is 68%. The tuning range of the emission wavelength is bigger than 270 pm. The calculated deviation in relative absorption efficiency caused by the fluctuations of wavelength and power is less than 4%.

  13. Application of COTS high-speed 980-nm pump laser diode and driver for free-space laser communication terminal

    NASA Astrophysics Data System (ADS)

    Chan, Eric Y.; Adams, Jeff C.; Saint Clair, Jonathan M.; Morrison, Kenneth A.; Sosa, Martin

    1999-06-01

    In our Photonics West 98 paper, we presented our study results on using commercially available 860 nm high power laser diodes and high-speed laser driver for free-space laser communication terminal application. We demonstrated the feasibility of a free space laser communication link using a junction-up 860 nm high power laser diode driven by a high current laser driver from Hytek Microsystems up to 622 Mb/s. Recent development in high speed InGaAs/GaAs strained layer quantum well (SLQW) laser at 980 nm has provided an additional design option for a laser communication terminal. The advantages of using the 980 nm laser are: (1) WDM market in the telecom industry has created a volume demand for the 980 nm pump lasers. The future cost of 980 nm lasers is expected to be lower due to the economy of scale. (2) In our previous publications, we have demonstrated CW operation of strained layer QW laser at temperature higher than 200 degree(s)C. There is a potential for this type of laser diode to operate in a much harsher and higher temperature environment, and (3) 980 nm pump laser has output power comparable to high power 860 nm laser diodes. In this paper, we will present the high data rate characteristics of a high-speed 980 nm (SLQW) pump laser. Using commercial-off-the-shelf laser drivers we will demonstrate the laser transmitter system characteristics from 622 Mb/s to 3 Gb/s. Detail experimental results on bit- error-rate measurement for a 980 nm device will be presented.

  14. Laser and solar-photovoltaic space power systems comparison. II.

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Stripling, J.; Enderson, T. M.; Humes, D. H.; Davis, W. T.

    1984-01-01

    A comparison of total system cost is made between solar photovoltaic and laser/receiver systems. The laser systems assume either a solar-pumped CO2 blackbody transfer laser with MHD receiver or a solar pumped liquid neodymium laser with a photovoltaic receiver. Total system costs are less for the laser systems below 300 km where drag is significant. System costs are highly dependent on altitude.

  15. Solar-pumped electronic-to-vibrational energy transfer lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Wilson, J. W.

    1981-01-01

    The possibility of using solar-pumped lasers as solar energy converters is examined. The absorbing media considered are halogens or halogen compounds, which are dissociated to yield excited atoms, which then hand over energy to a molecular lasing medium. Estimates of the temperature effects for a Br2-CO2-He system with He as the cooling gas are given. High temperatures can cause the lower energy levels of the CO2 laser transition to be filled. The inverted populations are calculated and lasing should be possible. However, the efficiency is less than 0.001. Examination of other halogen-molecular lasant combinations (where the rate coefficients are known) indicate efficiencies in all cases of less than 0.005.

  16. Modeling of a dual-wavelength pumped metastable argon laser

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Sun, PengFei; Wang, XinBing; Zuo, DuLuo

    2017-03-01

    Optically pumped metastable argon laser is an attractive research topic of innovative gas lasers, but the slow collisional relaxation rates of 1s 4-1s 5 (in Paschen notation) may form a bottleneck on the cycling of active atoms and decrease the laser output at room temperature. Here, by employing a method of a dual-wavelength pump, we demonstrate the removal of accumulation on the 1s 4 level and the improvement of output power in the simulation. The simulated results show that a large increase in laser output is possible with a relatively weak assistant pump intensity. This method offers a feasible way to scale the laser to higher gain.

  17. Temperature distribution in side- and end-pumped laser crystal rods - Temporal and spatial variations

    NASA Technical Reports Server (NTRS)

    Farrukh, Usamah O.; Brockman, Philip

    1993-01-01

    Knowledge of the temperature distribution of laser rods end pumped by laser diodes or other laser systems is relevant when thermal stress and crystal damage are expected. The temperature of a multipulsed or continuously pumped laser rod is given as a double-series expression and as a function of time. The mathematical model considers all surface cooling rates, the spatial and temporal variations of the pump beam, and the specific heat and thermal conductivity of the rod material. This eigenfunction expansion representation was employed to predict the spatial and time-dependent quasi-steady-state temperature in Ti:sapphire, Nd:YAG, and Cr:LiSAF laser rods of specific dimensions.

  18. Feasibility of supersonic diode pumped alkali lasers: Model calculations

    SciTech Connect

    Barmashenko, B. D.; Rosenwaks, S.

    2013-04-08

    The feasibility of supersonic operation of diode pumped alkali lasers (DPALs) is studied for Cs and K atoms applying model calculations, based on a semi-analytical model previously used for studying static and subsonic flow DPALs. The operation of supersonic lasers is compared with that measured and modeled in subsonic lasers. The maximum power of supersonic Cs and K lasers is found to be higher than that of subsonic lasers with the same resonator and alkali density at the laser inlet by 25% and 70%, respectively. These results indicate that for scaling-up the power of DPALs, supersonic expansion should be considered.

  19. Diode-pumped all-solid state lasers: solutions for scientific, biomedical, and industrial applications

    NASA Astrophysics Data System (ADS)

    Agnesi, Antoniangelo; Reali, Giancarlo C.

    1998-07-01

    Referring to the work carried out in our laboratory, we review low-medium power diode pumped all solid state laser systems for scientific, bio-medical and industrial applications. Side- and end-pumping are discussed and compared for such a laser systems. End-pumped scheme is mainly exploited in this report. Coupling solutions and cavity design are described emphasizing energy deposition and extraction optimization, thermal lens effects, beam quality control and longitudinal mode control. Both cw- and quasi-cw-pumped lasers are considered, operating either in continuous wave, passive Q-switching, and mode-locking regimes. Intracavity and extracavity harmonic generation, optical parametric generation and short pulse generation are among the aims of these all-solid-state sources: some result of these applications are reported.

  20. Diode-pumped Alexandrite ring laser for lidar applications

    NASA Astrophysics Data System (ADS)

    Munk, A.; Jungbluth, B.; Strotkamp, M.; Hoffmann, H.-D.; Poprawe, R.; Höffner, J.

    2016-03-01

    We present design and performance data of a diode-pumped Q-switched Alexandrite ring laser in the millijoule regime, which is longitudinally pumped by laser diode bar modules in the red spectral range. As a first step, a linear resonator was designed and characterized in qcw operation as well as in Q-switched operation. Based on these investigations, two separate linear cavities were set up, each with one Alexandrite crystal longitudinally pumped by one diode module. The two cavities are fused together and form a ring cavity which yields up to 6 mJ pulse burst energy in the qcw regime at 770 nm.

  1. 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.

  2. Recent development on high-power tandem-pumped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhou, Pu; Xiao, Hu; Leng, Jinyong; Zhang, Hanwei; Xu, Jiangmin; Wu, Jian

    2016-11-01

    High power fiber laser is attracting more and more attention due to its advantage in excellent beam quality, high electricto- optical conversion efficiency and compact system configuration. Power scaling of fiber laser is challenged by the brightness of pump source, nonlinear effect, modal instability and so on. Pumping active fiber by using high-brightness fiber laser instead of common laser diode may be the solution for the brightness limitation. In this paper, we will present the recent development of various kinds of high power fiber laser based on tandem pumping scheme. According to the absorption property of Ytterbium-doped fiber, Thulium-doped fiber and Holmium-doped fiber, we have theoretically studied the fiber lasers that operate at 1018 nm, 1178 nm and 1150 nm, respectively in detail. Consequently, according to the numerical results we have optimized the fiber laser system design, and we have achieved (1) 500 watt level 1018nm Ytterbium-doped fiber laser (2) 100 watt level 1150 nm fiber laser and 100 watt level random fiber laser (3) 30 watt 1178 nm Ytterbium-doped fiber laser, 200 watt-level random fiber laser. All of the above-mentioned are the record power for the corresponded type of fiber laser to the best of our knowledge. By using the high-brightness fiber laser operate at 1018 nm, 1178 nm and 1150 nm that we have developed, we have achieved the following high power fiber laser (1) 3.5 kW 1090 nm Ytterbium-doped fiber amplifier (2) 100 watt level Thulium-doped fiber laser and (3) 50 watt level Holmium -doped fiber laser.

  3. Modeling a diode pumped Nd: YAG rod laser

    NASA Astrophysics Data System (ADS)

    Shu, Hong; Chen, Ying; Bass, Michael; Acharekar, Madhu A.

    2006-02-01

    We evaluate the performance potential of a diode pumped Nd: YAG rod laser by finding the absorbed pump distribution using ASAP, pump induced thermal lensing, gain medium surface distortion and stresses using FEMLAB and depolarization losses using MATLAB. Beam propagation in the optically distorted Nd:YAG rod and the free space part of the cavity, and the output laser beam were determined with a computational scheme we developed which employs the beam propagation method combined with sparse matrix technology. We propose a special cavity design that can select the spatial eigen mode shape of the laser and simultaneously compensate for pump induced thermal lensing, gain medium surface distortion and birefringence. The converged solutions calculated this special cavity design give both high extraction efficiency and good output beam quality. Sensitivity of the output beam to mirror tilt, thermal induced mirror distortion, and errors in the cavity length or the optical distortions in the rod were also calculated.

  4. High average power diode pumped solid state laser

    NASA Astrophysics Data System (ADS)

    Gao, Yue; Wang, Yanjie; Chan, Amy; Dawson, Murray; Greene, Ben

    2017-03-01

    A new generation of high average power pulsed multi-joule solid state laser system has been developed at EOS Space Systems for various space related tracking applications. It is a completely diode pumped, fully automated multi-stage system consisting of a pulsed single longitudinal mode oscillator, three stages of pre-amplifiers, two stages of power amplifiers, completely sealed phase conjugate mirror or stimulated Brillouin scattering (SBS) cell and imaging relay optics with spatial filters in vacuum cells. It is capable of generating pulse energy up to 4.7 J, a beam quality M 2 ~ 3, pulse width between 10–20 ns, and a pulse repetition rate between 100–200 Hz. The system has been in service for more than two years with excellent performance and reliability.

  5. Capacitive-discharge-pumped copper bromide vapour laser

    SciTech Connect

    Sukhanov, V B; Fedorov, V F; Troitskii, V O; Gubarev, F A; Evtushenko, Gennadii S

    2007-07-31

    A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

  6. Ti : sapphire laser synchronised with femtosecond Yb pump laser via nonlinear pulse coupling in Ti : sapphire active medium

    NASA Astrophysics Data System (ADS)

    Didenko, N. V.; Konyashchenko, A. V.; Konyashchenko, D. A.; Kostryukov, P. V.; Kuritsyn, I. I.; Lutsenko, A. P.; Mavritskiy, A. O.

    2017-02-01

    A laser system utilising the method of synchronous pumping of a Ti : sapphire laser by a high-power femtosecond Yb3+-doped laser is described. The pulse repetition rate of the Ti : sapphire laser is successfully locked to the repetition rate of the Yb laser for more than 6 hours without the use of any additional electronics. The measured timing jitter is shown to be less than 1 fs. A simple qualitative model addressing the synchronisation mechanism utilising the cross-phase modulation of oscillation and pump pulses within a Ti : sapphire active medium is proposed. Output parameters of the Ti : sapphire laser as functions of its cavity length are discussed in terms of this model.

  7. The effect of pulsewidth of pumping pulse on the stability of distributed feedback dye laser

    NASA Astrophysics Data System (ADS)

    Pasandideh, K.; Rahbari, M.; Sadighi Bonabi, R.

    2017-04-01

    The generation of a single and stable picosecond pulse by distributed feedback dye laser is investigated in this work. The numerical result for the rate equation system that includes the thermal effects in the lasing medium is provided. By applying this model to Rhodamine 6G, it is found that considerable improvement in the stability of the laser can be achieved by pumping the system with narrower laser pulses. The simulation shows that if the dye solution is pumped by sub-200 ps pulse, the laser can be operated in single-pulse output mode with acceptable stability in pulsewidth over a long range of pumping intensity. This result is confirmed by a more complicated model composed of non-averaged Maxwell and rate equations. Even though the thermal effects do not play a significant role in equivalent cavity lifetime, they result in considerable wavelength shift toward the shorter wavelengths.

  8. Design and Construction of Simple, Nitrogen-Laser-Pumped, Tunable Dye Lasers

    ERIC Educational Resources Information Center

    Hilborn, Robert C.

    1978-01-01

    The basic physical principles of dye lasers are discussed and used to analyze the design and operation of tunable dye lasers pumped by pulsed nitrogen lasers. Details of the design and construction of these dye lasers are presented. Some simple demonstration experiments are described. (BB)

  9. Investigation of Diode Pumped Alkali Laser Atmospheric Transmission Using Tunable Diode Laser Absorption Spectroscopy

    DTIC Science & Technology

    2012-09-01

    101 325 Pa = 760 Torr † NIST 2006 CODATA recommended values 98 Appendix B. Alkali Data Potassium Properties Table 3. Potassium (K) physical...INVESTIGATION OF DIODE PUMPED ALKALI LASER ATMOSPHERIC TRANSMISSION USING TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY DISSERTATION Christopher A... ALKALI LASER ATMOSPHERIC TRANSMISSION USING TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY DISSERTATION Presented to the Faculty Graduate School of

  10. Diode-pumped solid state laser for inertial fusion energy

    SciTech Connect

    Payne, S.A.; Krupke, W.F.; Orth, C.D.

    1994-11-01

    The authors evaluate the prospect for development of a diode-pumped solid-state-laser driver in an inertial fusion energy power plant. Using a computer code, they predict that their 1 GWe design will offer electricity at 8.6 cents/kW {center_dot} hr with the laser operating at 8.6% efficiency and the recycled power level at 31%. The results of their initial subscale experimental testbed of a diode-pumped solid state laser are encouraging, demonstrating good efficiencies and robustness.

  11. Synchronously pumped mode-locked dye laser pumped by a frequency-doubled mode-locked and /ital Q/-switched diode laser pumped Nd:YAG laser

    SciTech Connect

    Maker, G. T.; Ferguson, A. I.

    1989-08-07

    We have developed a powerful and efficient mode-locked and /ital Q/-switched diode laser pumped Nd:YAG laser. Mode locking has been accomplished using intracavity frequency modulation (FM) to produce continuous-wave mode-locked pulses of 12 ps duration. Acousto-optic pre-lase /ital Q/ switching has produced a train of pulses of about 25 ps average duration at a repetition rate of 360 MHz in an envelope of 75 ns duration. When pumped with a 500 mW diode laser array, the energy in the /ital Q/-switched envelope was 15 /mu/J giving a peak power in the largest pulse of 19 kW. The laser has been frequency doubled in a crystal of potassium titanyl phosphate (KTP) with an efficiency of 36%. The doubled radiation at 532 nm has been used to synchronously pump a mode-locked rhodamine 6G dye laser to produce a train of tunable pulses. The pulse duration of the dye laser was 3.2 ps and the peak power of the largest pulse in the train was 10 kW.

  12. Electric-discharge-pumped nitrogen ion laser

    NASA Technical Reports Server (NTRS)

    Laudenslager, J. B.; Pacala, T. J.; Wittig, C.

    1976-01-01

    The routine operation is described of an N2(+) laser oscillating on the first negative band system of N2(+) which is produced in a preionized transverse discharge device. The discharge design incorporates features which favor the efficient production of the excitation transfer reaction of He2(+) with N2. A capacitive discharge switched by means of a high-current grounded grid thyratron is used to meet the design requirement of a volumetric discharge in high-pressure gas mixtures where the electric discharge need not have an ultrafast rise time (greater than 10 nsec) but should be capable of transferring large quantities of stored electric energy to the gas. A peak power of 180 kW in an 8-nsec laser pulse was obtained with a 0.1% mixture of N2 in helium at a total pressure of 3 atm. The most intense laser oscillations were observed on the (0,1) vibrational transition at 427.8 microns.

  13. 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.

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

    DOEpatents

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

    2009-05-26

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

  15. Laser diode pumped 106 mW blue upconversion fiber laser

    NASA Astrophysics Data System (ADS)

    Sanders, S.; Waarts, R. G.; Mehuys, D. G.; Welch, D. F.

    1995-09-01

    A laser diode pumped Tm3+-doped ZBLAN fiber upconversion laser is demonstrated with blue output power levels up to 106 mW. Differential optical-to-optical conversion efficiencies up to 30% are measured with respect to pump power coupled into the upconversion fiber. A single spatial mode blue output beam is demonstrated, with an M2 value of 1.4.

  16. Negative feedback system reduces pump oscillations

    NASA Technical Reports Server (NTRS)

    Rosenmann, W.

    1967-01-01

    External negative feedback system counteracts low frequency oscillations in rocket engine propellant pumps. The system uses a control piston to sense pump discharge fluid on one side and a gas pocket on the other.

  17. High energy diode-pumped solid-state laser development at the Central Laser Facility

    NASA Astrophysics Data System (ADS)

    Mason, Paul D.; Banerjee, Saumyabrata; Ertel, Klaus; Phillips, P. Jonathan; Butcher, Thomas; Smith, Jodie; De Vido, Mariastefania; Chekhlov, Oleg; Hernandez-Gomez, Cristina; Edwards, Chris; Collier, John

    2016-04-01

    In this paper we review the development of high energy, nanosecond pulsed diode-pumped solid state lasers within the Central Laser Facility (CLF) based on cryogenic gas cooled multi-slab ceramic Yb:YAG amplifier technology. To date two 10J-scale systems, the DiPOLE prototype amplifier and an improved DIPOLE10 system, have been developed, and most recently a larger scale system, DiPOLE100, designed to produce 100 J pulses at up to 10 Hz. These systems have demonstrated amplification of 10 ns duration pulses at 1030 nm to energies in excess of 10 J at 10 Hz pulse repetition rate, and over 100 J at 1 Hz, with optical-to-optical conversion efficiencies of up to 27%. We present an overview of the cryo-amplifier concept and compare the design features of these three systems, including details of the amplifier designs, gain media, diode pump lasers and the cryogenic gas cooling systems. The most recent performance results from the three systems are presented along with future plans for high energy DPSSL development within the CLF.

  18. Diode Pumped Alkali Vapor Lasers - A New Pathway to High Beam Quality at High Average Power

    SciTech Connect

    Page, R H; Boley, C D; Rubenchik, A M; Beach, R J

    2005-05-06

    Resonance-transition alkali-vapor lasers have only recently been demonstrated [1] but are already attracting considerable attention. Alkali-atom-vapor gain media are among the simplest possible systems known, so there is much laboratory data upon which to base performance predictions. Therefore, accurate modeling is possible, as shown by the zero- free-parameter fits [2] to experimental data on alkali-vapor lasers pumped with Ti:sapphire lasers. The practical advantages of two of the alkali systems--Rb and Cs--are enormous, since they are amenable to diode-pumping [3,4]. Even without circulating the gas mixture, these lasers can have adequate cooling built-in owing to the presence of He in their vapor cells. The high predicted (up to 70%) optical-to-optical efficiency of the alkali laser, the superb (potentially 70% or better) wall-plug efficiency of the diode pumps, and the ability to exhaust heat at high temperature (100 C) combine to give a power-scalable architecture that is lightweight. A recent design exercise [5] at LLNL estimated that the system ''weight-to-power ratio'' figure of merit could be on the order of 7 kg/kW, an unprecedented value for a laser of the 100 kW class. Beam quality is expected to be excellent, owing to the small dn/dT value of the gain medium. There is obviously a long way to go, to get from a small laser pumped with a Ti:sapphire or injection-seeded diode system (of near-perfect beam quality, and narrow linewidth) [1, 4] to a large system pumped with broadband, multimode diode- laser arrays. We have a vision for this technology-development program, and have already built diode-array-pumped Rb lasers at the 1 Watt level. A setup for demonstrating Diode-array-Pumped Alkali vapor Lasers (DPALs) is shown in Figure 1. In general, use of a highly-multimode, broadband pump source renders diode-array-based experiments much more difficult than the previous ones done with Ti:sapphire pumping. High-NA optics, short focal distances, and short

  19. Diode edge-pumped passively Q-switched microchip laser

    NASA Astrophysics Data System (ADS)

    Kong, Weipeng; Tsunekane, Masaki; Taira, Takunori

    2015-09-01

    There is an increasing demand for high-intensity subnanosecond lasers for emerging industrial applications. While femtosecond and picosecond laser sources are considered promising, they suffer from the significant drawbacks of increased complexity and cost. In this regard, we demonstrate a unique edge-pumped passively Q-switched Nd∶YAG/Cr4+∶YAG microchip laser. The microchip is made of a Nd∶YAG/Sm∶YAG composite ceramic, and a Sm∶YAG cladding is utilized as both the pump beam waveguide and amplified spontaneous emission absorber. With the use of a flat-concave laser cavity, we obtain single-pulse energy of 1.66 mJ for an absorbed pump energy of 24 mJ. Further, the resulting pulse width is 683 ps, and the repetition rate is 10 Hz.

  20. Fiber laser pumped burst-mode operated picosecond mid-infrared laser

    NASA Astrophysics Data System (ADS)

    Wei, Kai-Hua; Jiang, Pei-Pei; Wu, Bo; Chen, Tao; Shen, Yong-Hang

    2015-02-01

    We demonstrate a compact periodically poled MgO-doped lithium niobate (MgO:PPLN)-based optical parametric oscillator (OPO) quasi-synchronously pumped by a fiber laser system with burst-mode operation. The pump source is a peak-power-selectable pulse-multiplied picosecond Yb fiber laser. The chirped pulses from a figure of eight-cavity mode-locked fiber laser seed are narrowed to a duration of less than 50 ps using an FBG reflector and a circulator. The narrowed pulses are directed to pass through a pulse multiplier and to form pulse bunches, each of which is composed of 13 sub-pulses. The obtained pulse bunches are amplified by two-stage fiber pre-amplifiers: one-stage is core-pumped and the other is cladding-pumped. A fiberized acousto-optic modulator is inserted to control the pulse repetition rate (PRR) of the pulse bunches before they are power-amplified in the final amplifier stage with a large mode area (LMA) PM Yb-doped fiber. The maximum average powers from the final amplifier are 85 W, 60 W, and 45 W, respectively, corresponding to the PRR of 2.72 MHz, 1.36 MHz, and 0.68 MHz. The amplified pulses are directed to pump an MgO:PPLN-based optical parametric oscillator (OPO). A maximum peak power at 3.45 μm is obtained approximately to be 8.4 kW. Detailed performance characteristics are presented. Project supported by the National Natural Science Foundation of China (Grant No. 61078015) and the National Basic Research Program of China (Grant No. 2011CB311803).

  1. Optically pumped tunable HBr laser in the mid-infrared region.

    PubMed

    Koen, Wayne; Jacobs, Cobus; Bollig, Christoph; Strauss, Hencharl J; Esser, M J Daniel; Botha, Lourens R

    2014-06-15

    An optically pumped tunable HBr laser has been demonstrated for the first time. The pump source was a single-frequency Ho:YLF laser and amplifier system, which was locked to the 2064 nm absorption line of HBr. Laser oscillation was demonstrated on 19 molecular transition lines, which included both the R-branch (3870-4015 nm) and the P-branch (4070-4453 nm), by the use of an intra-cavity diffraction grating. The highest output energy was 2.4 mJ at 4133 nm.

  2. Bidirectional optical bistability in a dual-pumped erbium doped fiber ring laser.

    PubMed

    Lai, W J; Shum, P; Binh, L

    2004-11-15

    We investigate bidirectional optical wave propagations in a dual-pumped erbium doped fiber ring laser without isolator, and observe optical bistability behaviors. Consequently, we propose and construct a NOLM-NALM fiber ring laser to demonstrate and exploit this bidirectional optical bistability phenomenon in optical switching by introducing two tunable variable ratio couplers in the system. Numerical analyses based on the proposed laser structure have also been demonstrated corroborated with the experimental results.

  3. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  4. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  5. Femtosecond laser pulse induced phase transition of Cr-doped Sb2Te1 films studied with a pump-probe system

    NASA Astrophysics Data System (ADS)

    Jiang, Minghui; Wang, Qing; Lei, Kai; Wang, Yang; Liu, Bo; Song, Zhitang

    2016-10-01

    The Femtosecond laser pulse induced phase transition dynamics of Cr-doped Sb2Te1 films was studied by real-time reflectivity measurements with a pump-probe system. It was found that crystallization of the as-deposited CrxSb2Te1 phase-change thin films exhibits a multi-stage process lasting for about 40ns.The time required for the multi-stage process seems to be not related to the contents of Cr element. The durations of the crystallization and amorphization processes are approximately the same. Doping Cr into Sb2Te1 thin film can improve its photo-thermal stability without obvious change in the crystallization rate. Optical images and image intensity cross sections are used to visualize the transformed regions. This work may provide further insight into the phase-change mechanism of CrxSb2Te1 under extra-non-equilibrium conditions and aid to develop new ultrafast phase-change memory materials.

  6. Investigation of Diode Pumped Alkali Laser atmospheric transmission using tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Rice, Christopher A.

    A field deployable ruggedized tunable diode laser absorption spectroscopy (TDLAS) device fiber coupled to a pair of 12.5" Ritchey-Chretien telescopes was used to study atmospheric propagation for open path lengths of 100 to 1,000 meters to estimate atmospheric transmission at key High Energy Laser (HEL) wavelengths. The potassium (K) version of the Diode Pumped Alkali Laser (DPAL) operates in between two of the sharp oxygen rotational features in the PP and the PQ branches. The device can be used to observe rotational temperature, concentrations, and atmospheric pressure. Molecular oxygen absorption lines near the potassium, and water vapor absorption lines near the rubidium and cesium DPALs at wavelengths near 770 nm, 795 nm, and 895 nm, respectively, were investigated using the Line-by-Line Radiative Transfer Model (LBLRTM) with the High Energy Laser End-to-End Simulation (HELEEOS). A tunable diode laser absorption spectroscopy (TDLAS) device was used to anchor simulations to actual outdoor atmospheric open-path collections. The implications of different laser gain cell configurations in DPAL systems are discussed, including spectral lineshape and atmospheric transmittance and are compared to existing high power laser systems.

  7. Effects of pumping wavelength and pump density on the random laser performance of stoichiometric Nd crystal powders.

    PubMed

    Azkargorta, J; Iparraguirre, I; Bettinelli, M; Cavalli, E; Barredo-Zuriarrain, M; García-Revilla, S; Balda, R; Fernandez, J

    2014-11-03

    Laser slope and threshold properties have been investigated in Nd stoichiometric crystal powders as a function of pump wavelength and pump beam size. Above a given pumped area, the laser slope and the threshold pump energy per unit area are invariant and the known theoretical expressions are well fulfilled. Likewise, the size of the stimulated emission zone as a function of the pump beam area has been measured, also showing a different behavior above or below a given pumped area value which coincides with the one mentioned above. In conclusion, two different operating regimes with different performances are clearly observed as a function of the pump beam area.

  8. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1983-01-01

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  9. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1977-01-01

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  10. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  11. Tunable continuous wave single-mode dye laser directly pumped by a diode laser

    NASA Astrophysics Data System (ADS)

    Stefanska, D.; Suski, M.; Furmann, B.

    2017-04-01

    In this work, a tunable continuous wave single-mode ring dye laser (a modified version of Coherent model CR 699-21), directly optically pumped by an economy-class diode laser, has been set up. The laser was operated on Coumarin 498, and its generation profile covered part of the green spectral region not easily accessible in single-mode operation. The performance of the laser in both broad-band and single-mode operation regimes was studied. It was proved that optical pumping by diode lasers allows one to obtain single-mode operation of dye lasers that is sufficiently stable for high-resolution spectroscopy applications.

  12. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1979-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  13. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1982-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  14. Theory and experiments of dye lasers longitudinally pumped by copper vapor laser (CVL)

    NASA Astrophysics Data System (ADS)

    Sun, W.; Tang, C. S.; Zhuge, X. B.; Chen, M. S.

    1986-06-01

    Theoretical and experimental studies were performed on high prf dye lasers longitudinally pumped by CVL. Analytic expressions were derived for the laser output power and efficiency by using a rate equation treatment and taking the influence of excited singlet-state absorption into account. A CuBr laser-pumped dye laser with longitudinally pumped geometry and a jet stream was used in the experiment. A maximum output power of 1.3 W was achieved for Kiton red dye with an efficiency of 40%. Experimental results were in good agreement with theoretical analysis.

  15. Laser-diode-pumped Nd:YVO4/Nd:YAG MOPA burst-mode laser

    NASA Astrophysics Data System (ADS)

    Li, Xudong; Yan, Renpeng; Zhou, Yiping; Yu, Xin; Pan, Hu; Chen, Deying; Zhou, Zhongxiang

    2017-07-01

    We report a high-repetition-rate, high-peak-power laser diode (LD) pumped burst-mode 1064 nm laser from a Nd:YVO4/Nd:YAG master oscillator power amplifier. 10-100 kHz pulse burst in a duration up to 2 ms is achieved in LD end-pumped Nd:YVO4 acousto-optically Q-switched laser. After amplification with LD side-pumped Nd:YAG rod amplifiers, the single pulse energy reaches 73 mJ in 10 kHz pulse burst laser with a peak power of 7.8 MW.

  16. Thermal analysis in a solar pumped laser for Mg energy cycle

    NASA Astrophysics Data System (ADS)

    Bagheri, Behgol; Uchidat, Shgeaki

    2012-10-01

    Thermal analysis of a high-power cw solar-pumped laser under development as a magnesium energy cycle driver has been conducted experimentally and analytically. The laser system is equipped with a Fresnel lens and a cone-shaped secondary mirror chamber (SMC). The SMC realizes a hybrid-pumping scheme combining axial- and side-pumping configurations to enhance solar light absorption to a rod-shaped laser medium. A non-uniform temperature profile was obtained during experiments due to combination of volumetric heating and surface cooling, which leads to a nonuniform variation of index of refraction in the laser medium. The thermal lensing and thermal stress-induced birefringence are analyzed.

  17. Laser-diode pumped 40-W Yb:YAG ceramic laser.

    PubMed

    Hao, Qiang; Li, Wenxue; Pan, Haifeng; Zhang, Xiaoyi; Jiang, Benxue; Pan, Yubai; Zeng, Heping

    2009-09-28

    We demonstrated a high-power continuous-wave (CW) polycrystalline Yb:YAG ceramic laser pumped by fiber-pigtailed laser diode at 968 nm with 400 mum fiber core. The Yb:YAG ceramic laser performance was compared for different Yb(3+) ion concentrations in the ceramics by using a conventional end-pump laser cavity consisting of two flat mirrors with output couplers of different transmissions. A CW laser output of 40 W average power with M(2) factor of 5.8 was obtained with 5 mol% Yb concentration under 120 W incident pump power. This is to the best of our knowledge the highest output power in end-pumped bulk Yb:YAG ceramic laser.

  18. Conduction-cooled, continuous wave, diode-laser pumped, Nd:YAG mini-slab laser

    SciTech Connect

    Shine, R.J.; Alfrey, A.J.; Byer, R.L.

    1994-12-31

    We have designed a low loss mounting scheme for zig- zag slab lasers. This scheme includes a Teflon AF coating to protect the slab total internal reflection (TIR) surfaces. In addition, the slab is conduction cooled through a window to isolate the water flow from the slab surfaces. This design was initially tested on a line-pumped slab laser which operated with 5 watts of output power at a pump power of 28 watts. The laser operated in a TEM sub 00 mode at all powers. The low loss protective coating allowed this laser to operate on the lower gain line of Nd:YAG at 1.32, with 1.1 watt of output power at the same pump power. Since that time, a higher power laser has been built. This laser operates with a 20% slope efficiency, with an output power of 30 watts at a pump power of 160 watts.

  19. 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.

  20. Strong terahertz radiation from air plasmas generated by an aperture-limited Gaussian pump laser beam

    SciTech Connect

    Peng Xiaoyu; Toncian, Toma; Jung, Ralph; Willi, Oswald; Li Chun; Li Yutong; Wang Weimin; Wang Shoujun; Liu Feng; Chen Min; Pukhov, Alexander; Sheng Zhengming; Zhang Jie

    2009-03-09

    Terahertz radiation generated by focusing the fundamental laser pulse and its second harmonic into ambient air strongly saturates with increasing pump laser energy. We demonstrate a simple method to control the Gaussian pump laser beam to improve the output of terahertz radiation with an adjustable aperture. With the optimal aperture-limited pump laser beams, the terahertz wave amplitudes can be enhanced by more than eight times depending on the pump laser parameters than those of aperture-free cases.

  1. Demonstration of an all-diode-pumped soft x-ray laser.

    PubMed

    Furch, Federico J; Reagan, Brendan A; Luther, Bradley M; Curtis, Alden H; Meehan, Shaun P; Rocca, Jorge J

    2009-11-01

    We have demonstrated an 18.9 nm Ni-like molybdenum soft x-ray laser, pumped by a compact all-diode-pumped Yb:YAG laser. The solid-state pump laser produces 8.5 ps pulses with up to 1 J energy at 10 Hz repetition rate. This diode-pumped laser has the potential to greatly increase the repetition rate and the average power of soft x-ray lasers on a significantly smaller footprint.

  2. Absorption-heat-pump system

    DOEpatents

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    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.

  3. 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.

  4. X-ray pumped Cr,Nd:GSGG laser

    SciTech Connect

    Brannon, P.J.; Hedemann, M.A.; Weichman, L.S.

    1995-12-31

    It has been demonstrated that X-rays alone can be used to pump a 1,061 nm Cr,Nd:GSGG laser. Lasing action has been observed when the laser rod absorbs greater than 27 krad of 2 MeV X-rays. The laser cavity consists of a corner cube and a output mirror with a reflectivity of 67%. The X-rays are delivered in a 20 ns pulse, and laser action is observed several {micro}s after the X-ray pulse. This delay suggests that chromium is important in the laser pumping process since it is known that an excited chromium ion takes about 10 {micro}s to transfer its energy to a neodymium ion.

  5. Potential of solar-simulator-pumped alexandrite lasers

    NASA Technical Reports Server (NTRS)

    Deyoung, Russell J.

    1990-01-01

    An attempt was made to pump an alexandrite laser rod using a Tamarak solar simulator and also a tungsten-halogen lamp. A very low optical laser cavity was used to achieve the threshold minimum pumping-power requirement. Lasing was not achieved. The laser threshold optical-power requirement was calculated to be approximately 626 W/sq cm for a gain length of 7.6 cm, whereas the Tamarak simulator produces 1150 W/sq cm over a gain length of 3.3 cm, which is less than the 1442 W/sq cm required to reach laser threshold. The rod was optically pulsed with 200 msec pulses, which allowed the alexandrite rod to operate at near room temperature. The optical intensity-gain-length product to achieve laser threshold should be approximately 35,244 solar constants-cm. In the present setup, this product was 28,111 solar constants-cm.

  6. Pump-controlled modal interactions in microdisk lasers

    NASA Astrophysics Data System (ADS)

    Liew, Seng Fatt; Ge, Li; Redding, Brandon; Solomon, Glenn S.; Cao, Hui

    2015-04-01

    We demonstrate an effective control of nonlinear interactions of lasing modes in a semiconductor microdisk cavity by shaping the pump profile. A target mode is selected at the expense of its competing modes either by increasing their lasing thresholds or suppressing their power slopes above the lasing threshold. Despite the strong spatial overlap of the lasing modes at the disk boundary, adaptive pumping enables an efficient selection of any lasing mode to be the dominant one, leading to a switch of lasing frequency. The theoretical analysis illustrates both linear and nonlinear effects of selective pumping and quantifies their contributions to lasing-mode selection. This work shows that adaptive pumping not only provides a powerful tool to control the nonlinear process in multimode lasers, but also enables the tuning of lasing characteristic after the lasers have been fabricated.

  7. Direct solar pumping of semiconductor lasers: A feasibility study

    NASA Technical Reports Server (NTRS)

    Anderson, Neal G.

    1991-01-01

    The primary goals of the feasibility study are the following: (1) to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space directly focused sunlight; and (2) to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or battery electrically pumping a current injection laser. With external modulation, such lasers may prove to be efficient sources for intersatellite communications. We proposed to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation for operation at low pump intensities. This report outlines our progress toward these goals. Discussion of several technical details are left to the attached summary abstract.

  8. Screw-fed pump system

    DOEpatents

    Sprouse, Kenneth M

    2014-11-25

    A pump system includes a pump that includes a first belt and a second belt that are spaced apart from each other to provide generally straight sides of a passage there between. There is an inlet at one end of the passage and an outlet at an opposite end of the passage, with a passage length that extends between the inlet and the outlet. The passage defines a gap distance in a width direction between the straight sides at the passage inlet. A hopper includes an interior space that terminates at a mouth at the passage inlet. At least one screw is located within the interior space of the hopper and includes a screw diameter in the width direction that is less than or equal to the gap distance.

  9. Pump efficiency in solar-energy systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Study investigates characteristics of typical off-the-shelf pumping systems that might be used in solar systems. Report includes discussion of difficulties in predicting pump efficiency from manufacturers' data. Sample calculations are given. Peak efficiencies, flow-rate control, and noise levels are investigated. Review or theory of pumps types and operating characteristics is presented.

  10. Pump efficiency in solar-energy systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Study investigates characteristics of typical off-the-shelf pumping systems that might be used in solar systems. Report includes discussion of difficulties in predicting pump efficiency from manufacturers' data. Sample calculations are given. Peak efficiencies, flow-rate control, and noise levels are investigated. Review or theory of pumps types and operating characteristics is presented.

  11. Wavelength-multiplexed pumping with 478- and 520-nm indium gallium nitride laser diodes for Ti:sapphire laser.

    PubMed

    Sawada, Ryota; Tanaka, Hiroki; Sugiyama, Naoto; Kannari, Fumihiko

    2017-02-20

    We experimentally reveal the pump-induced loss in a Ti:sapphire laser crystal with 451-nm indium gallium nitride (InGaN) laser diode pumping and show that 478-nm pumping can reduce such loss. The influence of the pump-induced loss at 451-nm pumping is significant even for a crystal that exhibits higher effective figure-of-merit and excellent laser performance at 520-nm pumping. We demonstrate the power scaling of a Ti:sapphire laser by combining 478- and 520-nm InGaN laser diodes and obtain CW output power of 593 mW.

  12. 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.

  13. Axial pumps for propulsion systems

    NASA Technical Reports Server (NTRS)

    Huppert, M. C.; Rothe, K.

    1974-01-01

    The development of axial flow hydrogen pumps is examined. The design features and the performance data obtained during the course of the development programs are discussed. The problems created by the pump characteristics are analyzed. Graphs of four stage pump performance for various turbine blade configurations are developed. The characteristics and performance of a variety of pumps are included.

  14. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  15. High-power cw diode-laser-array-pumped solid-state lasers and efficient nonlinear optical frequency conversion. Final report

    SciTech Connect

    Shine, R.J.; Byer, R.L.

    1994-01-03

    During the interim period of this bridging contract, the authors have continued to work on the development of high-power cw diode-laser-array-pumped solid-state lasers. Towards that end, they have built lower power lasers in order to test individual components needed for the high-power laser, specifically they 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. They 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 them 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, they 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%.

  16. Broadly tunable, longitudinally diode-pumped Alexandrite laser

    NASA Astrophysics Data System (ADS)

    Strotkamp, M.; Witte, U.; Munk, A.; Hartung, A.; Gausmann, S.; Hengesbach, S.; Traub, M.; Hoffmann, H.-D.; Hoeffner, J.; Jungbluth, B.

    2014-02-01

    We present design and first performance data of a broadly tunable Alexandrite laser longitudinally pumped by a newly developed high brightness single emitter diode laser module with output in the red spectral range. Replacing the flashlamps, which are usually used for pumping Alexandrite, will increase the efficiency and maintenance interval of the laser. The pump module is designed as an optical stack of seven single-emitter laser diodes. We selected an optomechanical concept for the tight overlay of the radiation using a minimal number of optical components for collimation, e.g. a FAC and a SAC lens, and focusing. The module provides optical output power of more than 14 W (peak pulse output in the focus) with a beam quality of M2 = 41 in the fast axis and M2 = 39 in the slow axis. The Alexandrite crystal is pumped from one end at a repetition rate of 35 Hz and 200μs long pump pulses. The temperature of the laser crystal can be tuned to between 30 °C and 190 °C using a thermostat. The diode-pumped Alexandrite laser reaches a maximum optical-optical efficiency of 20 % and a slope efficiency of more than 30 % in fundamental-mode operation (M2 < 1.10). When a Findlay-Clay analysis with four different output couplers is conducted, the round-trip loss of the cavity is determined to be around 1 %. The wavelength is tunable to between 755 and 788 nm via crystal temperature or between 745 and 805 nm via an additional Brewster prism.

  17. Laser spark distribution and ignition system

    DOEpatents

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

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

  18. 3 μm diode-pumped solid state erbium laser for cataract surgery

    NASA Astrophysics Data System (ADS)

    Ernst, Holger; Ertmer, Wolfgang; Lubatschowski, Holger

    2003-06-01

    To improve the efficiency of laser phacoemulsification we developed a compact, high-repetition-rate, high-average-power, diode-pumped, 2.94 μm TIR-cavity Er:YAG laser system. Laser parameters of 19.4% slope efficiency, 5 W of average output power at up to 300 Hz repetition rate and more than 1.5 W at 1 kHz are demonstrated. The special design results in low thermal lenses of 1.9 Dpt/W. This is a good condition for high laser system scalability.

  19. Thulium:ZBLAN blue fiber laser pumped by two wavelengths

    SciTech Connect

    Tohmon, G.; Sato, H.; Ohya, J.; Uno, T.

    1997-05-01

    We demonstrate and analyze an upconversion blue fiber laser pumped by two wavelengths. Lasing at 0.48 {mu}m with very low pump threshold power is obtained from a Tm-doped fluorozirconate fiber that is counterpropagating pumped by 1.21- and 0.649-{mu}m light. We employed a rate-equation analysis using parameters obtained by fitting to the experimental data to predict the 0.48-{mu}m output characteristics as a function of fiber length and output reflectivity. {copyright} 1997 Optical Society of America

  20. New class of compact diode pumped sub 10-fs lasers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Le, T.; Müller, A.; Sumpf, B.; Jensen, O. B.; Hansen, A. K.; Andersen, P. E.

    2016-03-01

    Diode-pumping Ti:sapphire lasers promises a new approach to low-cost femtosecond light sources. Thus in recent years much effort has been taken just to overcome the quite low power and low beam qualities of available green diodes to obtain output powers of several hundred milliwatts from a fs-laser. In this work we present an alternative method by deploying frequency-doubled IR diodes with good beam qualities to pump fs-lasers. The revolutionary approach allows choosing any pump wavelengths in the green region and avoids complicated relay optics for the diodes. For the first time we show results of a diode-pumped 10 fs-laser and how a single diode setup can be integrated into a 30 x 30 cm2 fs-laser system generating sub 20 fs laser pulses with output power towards half a Watt. This technology paves the way for a new class of very compact and cost-efficient fs-lasers for life science and industrial applications.

  1. Stark effect in optically pumped molecular submillimeter lasers

    NASA Astrophysics Data System (ADS)

    Rak, V. G.; Dyubko, S. F.

    1980-06-01

    A theoretical analysis is made of the effects which take place in optically pumped lasers whose active medium is subjected to a dc electric Geld. The possibilities are discussed of tuning the frequency and modulating the intensity of the radiation emitted by a laser. The gain characteristics of an active medium in an electric field are calculated for a CH3F laser operating on a wavelength of 496 μ. It is shown that the frequency tuning limits of the output radiation of such a laser can reach 3 GHz, if the active medium allows electric fields of up to 30 kV/cm to be applied.

  2. A cladding-pumped, tunable holmium doped fiber laser.

    PubMed

    Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John; Carter, Adrian

    2013-11-18

    We present a tunable, high power cladding-pumped holmium doped fiber laser. The laser generated >15 W CW average power across a wavelength range of 2.043 - 2.171 μm, with a maximum output power of 29.7 W at 2.120 μm. The laser also produced 18.2 W when operating at 2.171 µm. To the best of our knowledge this is the highest power operation of a holmium doped laser at a wavelength >2.15 µm. We discuss the significance of background losses and fiber design for achieving efficient operation in holmium doped fibers.

  3. Optimization of rod diameter in solid state lasers side pumped with multiple laser diode arrays

    NASA Technical Reports Server (NTRS)

    Sims, Newton, Jr.; Chamblee, Christyl M.; Barnes, Norman P.; Lockard, George E.; Cross, Patricia L.

    1992-01-01

    Results of a study to determine the optimum laser rod diameter for maximum output energy in a solid state neodymium laser transversely pumped with multiple laser diode arrays are reported here. Experiments were performed with 1.0 mm, 1.5 mm and 2.0 mm rod radii of both neodymium doped Y3Al5O12 (Nd:YAG) and La2Be2O5 (Nd:BeL) pumped with laser diode arrays having a maximum combined energy of 10.5 mJ. Equations were derived which predict the optimum rod radius and corresponding output mirror reflectivity for a given laser material and total pump energy. Predictions of the equations agreed well with the experiments for each of the laser materials which possessed significantly different laser properties from one another.

  4. Laser-diode and Flash Lamp Pumped Solid-State Lasers

    NASA Astrophysics Data System (ADS)

    Garrec, Bruno Le

    2010-04-01

    Since the early 80's, most authors are considering that to enable high-average-power operation at the highest laser efficiency, it is necessary to replace flash lamp pumped solid-state lasers with laser-diode pumped solid-state lasers. This assumption is based on the fact that diode pumping has many advantages compared to flash lamp pumping that is seen as an old technology. Although it is very difficult to get true numbers, we shall show that Diode Pumped Solid State Lasers nearby the kW level have a moderate efficiency (<<10%), lower than expected. Flash lamp pumped fusion lasers are still in the run with a low efficiency but can access high beam quality and high harmonic generation efficiency. For the ELI project, we believe that considering a flash lamp pumped laser makes sense when the amplifier can run at 1 shot/mn to delivering 200J of green light. We shall show that it is an engineering problem to be solved with the help of: adaptive optic and large non linear crystals.

  5. 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.

  6. Scaling of an Optically Pumped Mid-Infrared Rubidium Laser

    DTIC Science & Technology

    2015-03-26

    A maximum slope efficiency based on incident pump photons of 1.7 × 10-4 was observed. Evidence that only a small percentage (ɚ%) of the available...Optically pumped 62P3/2 - 6 2S1/2 and 6 2P1/2 - 6 2S1/2 Rb lasing has been demonstrated in the past on two occasions. Sharma demonstrated a continuous...concentration on laser output energy. Specifically, it was demonstrated that bleached limit, slope efficiency, and laser output energy scale

  7. Graphene surface emitting terahertz laser: Diffusion pumping concept

    SciTech Connect

    Davoyan, Arthur R.; Morozov, Mikhail Yu.; Popov, Vyacheslav V.; Satou, Akira; Otsuji, Taiichi

    2013-12-16

    We suggest a concept of a tunable graphene-based terahertz (THz) surface emitting laser with diffusion pumping. We employ significant difference in the electronic energy gap of graphene and a typical wide-gap semiconductor, and demonstrate that carriers generated in the semiconductor can be efficiently captured by graphene resulting in population inversion and corresponding THz lasing from graphene. We develop design principles for such a laser and estimate its performance. We predict up to 50 W/cm{sup 2} terahertz power output for 100 kW/cm{sup 2} pump power at frequency around 10 THz at room temperature.

  8. Acousto-optic modulation in diode pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Jabczynski, Jan K.; Zendzian, Waldemar; Kwiatkowski, Jacek

    2007-02-01

    The main properties of acousto-optic modulators (AOM) applied in laser technology are presented and discussed in the paper. The critical review of application of AOMs in several types of diode pumped solid state lasers (DPSSL) is given. The short description of few DPSSLs developed in our group is presented in the following chapters of the paper. The parameters of a simple AO-Q-switched Nd:YVO 4 laser (peak power up to 60 kW, pulse duration of 5-15 ns, repetition rate in the range 10-100 kHz, with average power above 5 W) are satisfactory for different application as follows: higher harmonic generation, pumping of 'eye-safe' OPOs etc. The achieved brightness of 10 17 W/m2/srd is comparable to the strongest technological Q-switched lasers of kW class of average power. The main aim of paper is to present novel type of lasers with acousto-optic modulation namely: AO-q-switched and mode locked (AO-QML) lasers. We have designed the 3.69-m long Z-type resonator of the frequency matched to the RF frequency of AOM. As a gain medium the Nd:YVO 4 crystal end pumped by 20 W laser diode was applied. The energy of envelope of QML pulse train was up to 130 μJ with sub-nanosecond mode locked pulse of maximum 30-μJ energy.

  9. Nonlinear fibre-optic devices pumped by semiconductor disk lasers

    SciTech Connect

    Chamorovskiy, A Yu; Okhotnikov, Oleg G

    2012-11-30

    Semiconductor disk lasers offer a unique combination of characteristics that are particularly attractive for pumping Raman lasers and amplifiers. The advantages of disk lasers include a low relative noise intensity (-150 dB Hz{sup -1}), scalable (on the order of several watts) output power, and nearly diffraction-limited beam quality resulting in a high ({approx}70 % - 90 %) coupling efficiency into a single-mode fibre. Using this technology, low-noise fibre Raman amplifiers operating at 1.3 {mu}m in co-propagation configuration are developed. A hybrid Raman-bismuth doped fibre amplifier is proposed to further increase the pump conversion efficiency. The possibility of fabricating mode-locked picosecond fibre lasers operating under both normal and anomalous dispersion is shown experimentally. We demonstrate the operation of 1.38-{mu}m and 1.6-{mu}m passively mode-locked Raman fibre lasers pumped by 1.29-{mu}m and 1.48-{mu}m semiconductor disk lasers and producing 1.97- and 2.7-ps pulses, respectively. Using a picosecond semiconductor disk laser amplified with an ytterbium-erbium fibre amplifier, the supercontinuum generation spanning from 1.35 {mu}m to 2 {mu}m is achieved with an average power of 3.5 W. (invited paper)

  10. Diode-Pumped, Q-Switched, Frequency-Doubling Laser

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James R.

    1993-01-01

    Experimental Q-switched, diode-pumped, intracavity-frequency-doubling laser generates pulses of radiation at wavelength of 532 nm from excitation at 810 nm. Principal innovative feature distinguishing laser from others of its type: pulsed operation of laser at pulse-repetition frequencies higher than reported previously. Folded resonator keeps most of second-harmonic radiation away from Q-switcher, laser crystal, and laser diodes. Folding mirror highly reflective at fundamental laser wavelength and highly transmissive at second-harmonic laser wavelength. By virtue of difference of about 0.6 percent between reflectivities in two polarizations at fundamental wavelength, folding mirror favors polarized oscillation at fundamental wavelength. This characteristic desirable for doubling of frequency in some intracavity crystals.

  11. Threshold kinetics of a solar-simulator-pumped iodine laser

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Lee, Y.; Weaver, W. R.; Humes, D. H.; Lee, J. H.

    1984-01-01

    A model of the chemical kinetics of the n-C3F7I solar-simulator-pumped iodine laser is utilized to study the major kinetic processes associated with the threshold behavior of this experimental system. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state recombination with the alkyl radical and quenching by the parent gas control threshold at higher pressures. Treatment of the hyperfine splitting and uncertainty in the pressure broadening are important factors in fixing the threshold level. In spite of scatter in the experimental data caused by instabilities in the simulator high-pressure high-pressure arc, reasonable agreement is achieved between the model and experiment. Model parameters arrived at are within the uncertainty range of values found in the literature.

  12. Vertical cavity surface-emitting semiconductor lasers with injection laser pumping

    NASA Astrophysics Data System (ADS)

    McDaniel, D. L., Jr.; McInerney, J. G.; Raja, M. Y. A.; Schaus, C. F.; Brueck, S. R. J.

    1990-05-01

    Continuous-wave GaAs/GaAlAs edge-emitting diode lasers were used to pump GaAs/AlGaAs and InGaAs/AlGaAs vertical cavity surface-emitting lasers (VCSELs) with resonant periodic gain (RPG) at room temperature. Pump threshold as low as 11 mW, output powers as high as 27 mW at 850 nm, and external differential quantum efficiencies of about 70 percent were observed in GaAs/AlGaAs surface -emitters; spectral brightness 22 times that of the pump laser was also observed. Output powers as high as 85 mW at 950 nm and differential quantum efficiencies of up to 58 percent were recorded for the InGaAs surface-emitting laser. This is the highest quasi-CW output power ever reported for any RPG VCSEL, and the first time such a device has been pumped using an injection laser diode.

  13. A compact spin-exchange optical pumping system for 3He polarization based on a solenoid coil, a VBG laser diode, and a cosine theta RF coil

    NASA Astrophysics Data System (ADS)

    Lee, Sungman; Kim, Jongyul; Moon, Myung Kook; Lee, Kye Hong; Lee, Seung Wook; Ino, Takashi; Skoy, Vadim R.; Lee, Manwoo; Kim, Guinyun

    2013-02-01

    For use as a neutron spin polarizer or analyzer in the neutron beam lines of the HANARO (High-flux Advanced Neutron Application ReactOr) nuclear research reactor, a 3He polarizer was designed based on both a compact solenoid coil and a VBG (volume Bragg grating) diode laser with a narrow spectral linewidth of 25 GHz. The nuclear magnetic resonance (NMR) signal was measured and analyzed using both a built-in cosine radio-frequency (RF) coil and a pick-up coil. Using a neutron transmission measurement, we estimated the polarization ratio of the 3He cell as 18% for an optical pumping time of 8 hours.

  14. Further development of high-power pump laser diodes

    NASA Astrophysics Data System (ADS)

    Schmidt, Berthold; Lichtenstein, Norbert; Sverdlov, Boris; Matuschek, Nicolai; Mohrdiek, Stefan; Pliska, Tomas; Mueller, Juergen; Pawlik, Susanne; Arlt, Sebastian; Pfeiffer, Hans-Ulrich; Fily, Arnaud; Harder, Christoph

    2003-12-01

    AlGaAs/InGaAs based high power pump laser diodes with wavelength of around 980 nm are key products within erbium doped fiber amplifiers (EDFA) for today's long haul and metro-communication networks, whereas InGaAsP/InP based laser diodes with 14xx nm emission wavelength are relevant for advanced, but not yet widely-used Raman amplifiers. Due to the changing industrial environment cost reduction becomes a crucial factor in the development of new, pump modules. Therefore, pump laser chips were aggressively optimized in terms of power conversion and thermal stability, which allows operation without active cooling at temperatures exceeding 70°C. In addition our submarine-reliable single mode technology was extended to high power multi-mode laser diodes. These light sources can be used in the field of optical amplifiers as well as for medical, printing and industrial applications. Improvements of pump laser diodes in terms of power conversion efficiency, fiber Bragg grating (FBG) locking performance of single mode devices, noise reduction and reliability will be presented.

  15. An economic evaluation comparison of solar water pumping system with engine pumping system for rice cultivation

    NASA Astrophysics Data System (ADS)

    Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn

    2015-08-01

    In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.

  16. Spectroscopy of {sup 127}I{sub 2} hyperfine structure near 532 mm using frequency - doubled diode - laser - pumped Nd:YAG lasers

    SciTech Connect

    Guellati, S.; Elandaloussi, H.; Fretel, E.

    1994-12-31

    Frequency - doubled diode - laser - pumped Nd : Yag laser can constitute an interesting optical standard around 532 nm. More than ten of {sup 127}I{sub 2} lines can be observed inside the laser spectral range. Two independent systems, stabilized on one {sup 127}I{sub 2} hyperfine component, are used to check the frequency long term stability for metrological purpose.

  17. Ultra high brightness laser diode arrays for pumping of compact solid state lasers and direct applications

    NASA Astrophysics Data System (ADS)

    Kohl, Andreas; Fillardet, Thierry; Laugustin, Arnaud; Rabot, Olivier

    2012-10-01

    High Power Laser Diodes (HPLD) are increasingly used in different fields of applications such as Industry, Medicine and Defense. Our significant improvements of performances (especially in power and efficiency) and a reproducible manufacturing process have led to reliable, highly robust components. For defense and security applications these devices are used predominantly for pumping of solid state lasers (ranging, designation, countermeasures, and sensors). Due to the drastically falling price per watt they are more and more replacing flash lamps as pump sources. By collimating the laser beam even with a bar to bar pitch of only 400μm. cutting edge brightness of our stacks.is achieved Due the extremely high brightness and high power density these stacks are an enabling technology for the development of compact highly efficient portable solid state lasers for applications as telemeters and designators on small platforms such as small UAVs and handheld devices. In combination with beam homogenizing optics their compact size and high efficiency makes these devices perfectly suited as illuminators for portable active imaging systems. For gated active imaging systems a very short pulse at high PRF operation is required. For this application we have developed a diode driver board with an efficiency several times higher than that of a standard driver. As a consequence this laser source has very low power consumption and low waste heat dissipation. In combination with its compact size and the integrated beam homogenizing optics it is therefore ideally suited for use in portable gated active imaging systems. The kWatt peak power enables a range of several hundred meters. The devices described in this paper mostly operate at wavelength between 800 nm and 980nm. Results from diodes operating between 1300 nm and 1550 nm are presented as well.

  18. Fiber-laser pumped actively Q-switched Er:LuYAG laser at 1648 nm

    NASA Astrophysics Data System (ADS)

    Yang, X. F.; Wang, Y.; Zhao, T.; Zhu, H. Y.; Shen, D. Y.

    2016-02-01

    We demonstrated an acousto-optic Q-switched 1648 nm Er:LuYAG laser resonantly pumped by a cladding-pumped Er,Yb fiber laser at 1532 nm. Stable Q-switching operation was obtained with the pulse repetition rate (PRR) varying from 200 Hz to 10 kHz. At PRR of 200 Hz, the laser yielded Q-switched pulses with 3.3 mJ pulse energy and 65 ns pulse duration, corresponding to a peak power of 50.7 kW for 10.4 W of incident pump power.

  19. Microchip solid-state cylindrical vector lasers with orthogonally polarized dual laser-diode end pumping.

    PubMed

    Otsuka, Kenju; Chu, Shu-Chun

    2013-05-01

    We report a simple method for generating cylindrical vector beams directly from laser-diode (LD)-pumped microchip solid-state lasers by using dual end-pumping beams. Radially as well as azimuthally polarized vector field emissions have been generated from the common c-cut Nd:GdVO4 laser cavity merely by controlling the focus positions of orthogonally polarized LD off-axis pump beams. Hyperbolically polarized vector fields have also been observed, in which the cylindrical symmetry of vector fields is broken. Experimental results have been well reproduced by numerical simulations.

  20. Single-mode, All-Solid-State Nd:YAG Laser Pumped UV Converter

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Armstrong, Darrell, J.; Edwards, William C.; Singh, Upendra N.

    2008-01-01

    In this paper, the status of a high-energy, all solid-state Nd:YAG laser pumped nonlinear optics based UV converter development is discussed. The high-energy UV transmitter technology is being developed for ozone sensing applications from space based platforms using differential lidar technique. The goal is to generate greater than 200 mJ/pulse with 10-50 Hz PRF at wavelengths of 308 nm and 320 nm. A diode-pumped, all-solid-state and single longitudinal mode Nd:YAG laser designed to provide conductively cooled operation at 1064 nm has been built and tested. Currently, this pump laser provides an output pulse energy of >1 J/pulse at 50 Hz PRF and a pulsewidth of 22 ns with an electrical-to-optical system efficiency of greater than 7% and a M(sup 2) value of <2. The single frequency UV converter arrangement basically consists of an IR Optical Parametric Oscillator (OPO) and a Sum Frequency Generator (SFG) setups that are pumped by 532 nm wavelength obtained via Second Harmonic Generation (SHG). In this paper, the operation of an inter cavity SFG with CW laser seeding scheme generating 320 nm wavelength is presented. Efforts are underway to improve conversion efficiency of this mJ class UV converter by modifying the spatial beam profile of the pump laser.

  1. Septic tank effluent pump systems

    SciTech Connect

    Ball, H.L.; Bounds, T.R.

    1998-07-01

    Septic tank effluent pump (STEP) systems are beginning to be recognized as the preferred and most economical method of collecting and transporting partially-treated wastewater to a treatment facility. A conventional septic tank provides pretreatment, removing most settable and floatable solids from the wastewater. Specially designed pumps convey the septic tank effluent under pressure through a network of small diameter plastic piping to a treatment site. Shallow collection lines, following the contours of the terrain, eliminate the need for costly deep excavations. Changes in both vertical and horizontal alignments may be made in the field. The impetus for this rapidly developing technology has come mainly from the western US. Oregon's Department of Environmental Quality, for example, requires engineers to consider STEP systems whenever a new wastewater collection project is contemplated. The success of a STEP system depends primarily on the skill of the engineer in designing and managing the project. Guidelines for designers are discussed and brief descriptions of several successful STEP systems are included.

  2. LED pumped Nd:YAG laser development program

    NASA Technical Reports Server (NTRS)

    Farmer, G. I.; Kiang, Y. C.; Lynch, R. J.

    1973-01-01

    The results of a development program for light emitting diode (LED) pumped Nd:YAG lasers are described. An index matching method to increase the coupling efficiency of the laser is described. A solid glass half-cylinder of 5.0 by 5.6 centimeters was used for index matching and also as a pumping cavity reflector. The laser rods were 1.5 by 56 millimeters with dielectric coatings on both end surfaces. The interfaces between the diode array, glass cylinder, and laser rod were filled with viscous fluid of refractive index n = 1.55. Experiments performed with both the glass cylinder and a gold coated stainless steel reflector of the same dimensions under the same operating conditions indicate that the index matching cylinder gave 159 to 200 percent improvement of coupling efficiency over the metal reflector at various operating temperatures.

  3. Advances in NASA research on nuclear-pumped lasers

    NASA Technical Reports Server (NTRS)

    De Young, R. J.

    1982-01-01

    NASA has been primarily interested in nuclear-pumped lasers using the He-3 or U-235F6 reaction for lasant excitation. With He-3 excitation, a large volume, multiple-path He-3-Ar nuclear laser has produced an output of 1 kilowatt. Power deposition was shown to be homogeneous over this volume. The CO laser has been pumped for the first time using the He-3 reaction, producing approximately 200 Watts. Using a boron-10 coating to excite N2, nuclear lasing has been achieved in CO2 in a transfer laser configuration. Nuclear lasing of Ar-Xe has been demonstrated using fission fragment excitation from U-235F6. Research on the gas core reactor has resulted in a steady state operational power of 30 kilowatts with flowing U-235F6 in an argon vortex.

  4. Room temperature CW and QCW operation of Ho:CaF2 laser pumped by Tm:fiber laser

    NASA Astrophysics Data System (ADS)

    Jelínek, Michal; Cvrček, Jan; Kubeček, Václav; Zhao, Beibei; Ma, Weiwei; Jiang, Dapeng; Su, Liangbi

    2017-05-01

    Laser radiation in the wavelength range around 2 μm is required for its specific properties - it is very suitable for medical applications, remote sensing, or pumping of optical parametric oscillators to generate ultrafast pulses in the mid-IR region further exploited in nonlinear optics. Crystals as YLF, YAG, LLF, and GdVO4 doped by holmium were already investigated and found suitable for the tunable laser generation around 2.1 mμ. Only a few works are devoted to the laser operation of holmium-doped fluorides as CaF2. In this work, pulsed and continuous-wave laser operation of a modified- Bridgman-grown Ho:CaF2 active crystal at room temperature is reported. A commercial 50 W 1940 nm Tm-fiber laser was used to pump a laser oscillator based on a novel 10 mm long 0.5 at.% Ho:CaF2 active crystal placed in the Peltiercooled holder. In the pulsed regime (10 ms, 10 Hz), the laser slope efficiency of 53 % with respect to the absorbed pump power was achieved. The laser generated at the central wavelength of 2085 nm with the maximum mean output power of 365 mW corresponding to the power amplitude of 3.65 W. In the continuous wave regime, the maximum output power was 1.11 W with the slope efficiency of 41 % with respect to the absorbed pump power. To our best knowledge this is the first demonstration of this laser active material operating in the CW regime at room temperature. The tuning range over 60 nm from 2034 to 2094 nm was achieved using a birefringent filter showing the possibility to develop a mode-locked laser system generating pulses in the sub-picosecond range.

  5. Quantitative pump-induced wavefront distortions in laser-diode- and flash-lamp-pumped Nd:YLF laser rods

    SciTech Connect

    Skeldon, M.D.; Saager, R.B.; Seka, W.

    1999-03-01

    Detailed interferometric measurements of the induced thermal distortions due to laser-diode and xenon flashlamp pumping of Nd:YLF are presented. The thermal distortions are quantified in terms of the primary aberrations of defocus, astigmatism, coma, and spherical. Defocus and astigmatism are shown to dominate the thermal aberrations. The measured defocus and astigmatism are converted to the conventional thermal-focal lengths in two perpendicular directions with respect to the Nd:YLF crystalline c axis for each of the two polarization states {sigma} and {pi}. A comparison of the thermal-focal lengths measured with the xenon flashlamp- and laser-diode-pumped rods is given when the rods are pumped to the same small-signal gain. The authors calculate effective dioptric-power coefficients from the data for comparison to those reported in the literature for krypton-flashlamp pumping. A thermal-time constant of 1.5 s is measured for the laser-diode-pumped Nd:YLF laser rod.

  6. Broadband Pumping Effects on the Diode Pumped Alkali Laser

    DTIC Science & Technology

    2011-03-01

    vaccuum) Cs…………………………………………………………………………………... Cesium E……………………………………………..………………………..ethane concentration Fr…………………………………………………………………….……………Francium gi... Sodium Ni……………………………………………………………population density of ith level …………...………………….……………………………….….….quantum efficiency r...narrow-banding, laser photon engine [2]. An alkali, typically Rubidium (Rb) or Cesium (Cs), is heated to its gas phase and subject to diode

  7. Transverse Diode Pumping of Solid-State Lasers

    DTIC Science & Technology

    1992-05-29

    more common apertures (laser rod end and cavity end mirror ) leads to a thin-film coating damage issue. The transverse pumped geometry avoids the...proprietary one-half inch square cooler developed for high-power adaptive optics mirror applications. The laser performance observed, with up to 35 watts of...including the development of active mirrors capable of sustaining high power loadings. As part of those efforts, TTC has developed a small (one-half inch

  8. Cladding for transverse-pumped solid-state laser

    NASA Technical Reports Server (NTRS)

    Byer, Robert L. (Inventor); Fan, Tso Y. (Inventor)

    1989-01-01

    In a transverse pumped, solid state laser, a nonabsorptive cladding surrounds a gain medium. A single tranverse mode, namely the Transverse Electromagnetic (TEM) sub 00 mode, is provided. The TEM sub 00 model has a cross sectional diameter greater than a transverse dimension of the gain medium but less than a transverse dimension of the cladding. The required size of the gain medium is minimized while a threshold for laser output is lowered.

  9. Optimized Biasing of Pump Laser Diodes in a Highly Reliable Metrology Source for Long-Duration Space Missions

    NASA Technical Reports Server (NTRS)

    Poberezhskiy, Ilya Y; Chang, Daniel H.; Erlig, Herman

    2011-01-01

    Optical metrology system reliability during a prolonged space mission is often limited by the reliability of pump laser diodes. We developed a metrology laser pump module architecture that meets NASA SIM Lite instrument optical power and reliability requirements by combining the outputs of multiple single-mode pump diodes in a low-loss, high port count fiber coupler. We describe Monte-Carlo simulations used to calculate the reliability of the laser pump module and introduce a combined laser farm aging parameter that serves as a load-sharing optimization metric. Employing these tools, we select pump module architecture, operating conditions, biasing approach and perform parameter sensitivity studies to investigate the robustness of the obtained solution.

  10. Optimized Biasing of Pump Laser Diodes in a Highly Reliable Metrology Source for Long-Duration Space Missions

    NASA Technical Reports Server (NTRS)

    Poberezhskiy, Ilya Y; Chang, Daniel H.; Erlig, Herman

    2011-01-01

    Optical metrology system reliability during a prolonged space mission is often limited by the reliability of pump laser diodes. We developed a metrology laser pump module architecture that meets NASA SIM Lite instrument optical power and reliability requirements by combining the outputs of multiple single-mode pump diodes in a low-loss, high port count fiber coupler. We describe Monte-Carlo simulations used to calculate the reliability of the laser pump module and introduce a combined laser farm aging parameter that serves as a load-sharing optimization metric. Employing these tools, we select pump module architecture, operating conditions, biasing approach and perform parameter sensitivity studies to investigate the robustness of the obtained solution.

  11. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S.; Wetherington, Jr., Grady R.

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  12. 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.

  13. Random distributed feedback Raman fiber laser with polarized pumping

    NASA Astrophysics Data System (ADS)

    Wu, H.; Wang, Z. N.; Churkin, D. V.; Vatnik, I. D.; Fan, M. Q.; Rao, Y. J.

    2015-01-01

    In this letter, the polarization properties of a random fiber laser operating via Raman gain and random distributed feedback owing to Rayleigh scattering are investigated for the first time. Using polarized pump, the partially polarized generation is obtained with a generation spectrum exhibiting discrete narrow spectral features contrary to the smooth spectrum observed for the depolarized pump. The threshold, output power, degree of polarization and the state of polarization (SOP) of the lasing can be significantly influenced by the SOP of the pump. Fine narrow spectral components are also sensitive to the SOP of the pump wave. Furthermore, we found that random lasing’s longitudinal power distributions are different in the case of polarized and depolarized pumping that results in considerable reduction of the generation slope efficiency for the polarized radiation. Our results indicate that polarization effects play an important role on the performance of the random fiber laser. This work improves the understanding of the physics of random lasing in fibers and makes a step forward towards the establishment of the vector model of random fiber lasers.

  14. High-power pulsed diode-pumped Er:ZBLAN fiber laser.

    PubMed

    Gorjan, Martin; Petkovšek, Rok; Marinček, Marko; Čopič, Martin

    2011-05-15

    We report on the operation and performance of a gain-switched Er:ZBLAN fiber laser based on an active pulsed diode pump system. The produced laser pulses offer high peak powers while retaining the high average powers and efficiency of the cw regime. The measured pulse duration was about 300 ns and nearly independent of the pump repetition frequency. The maximum obtained 68 W of peak power is the highest reported, to our knowledge, for diode-pumped Er:ZBLAN fiber lasers, and the 2 W of average power at the repetition frequency of 100 kHz is 2 orders of magnitude higher than previously reported average power in a pulsed regime. The obtained slope efficiency was 34%.

  15. A stable gain-switched Ho:CYA laser resonantly pumped at 1922 nm

    NASA Astrophysics Data System (ADS)

    Zhang, J. N.; Chen, B. H.; Shen, D. Y.; Xu, X. D.

    2017-04-01

    We report on a gain-switched Ho:CaYAlO4 laser resonantly pumped by a home-constructed high power Tm:fiber laser at ~1922 nm. Stable nanosecond single-pulse operation could be maintained when the continuous-wave pump signal was modulated at repetition rates of 60–100 kHz with an acousto-optic modulator. A pulse duration of 311 ns has been obtained at a 60 kHz repetition rate under a pump power level of 11 W. The temporal stability and simplicity of operation make this laser suitable for a variety of applications, such as spectroscopy, gas sensing, and as the seed source of a master oscillation power amplifier system.

  16. Rapid prototyping of a micro pump with laser micromaching

    SciTech Connect

    Wong, C.C.; Chu, D.; Liu, S.L.; Tuck, M.R.; Mahmud, Z.; Amatucci, V.

    1995-08-01

    A micro electrohydrodynamic (EHD) injection pump has been developed using laser micromaching technology. Two designs have been fabricated, tested, and evaluated. The first design has two silicon pieces with KOH-etched wells which are stacked on the top of each other. The wells am etched on one side of the wafer and gold is deposited on the other side to serve as the pump electrodes. A ND:YAG laser is used to drill an array holes in the well region of both silicon die. This creates a grid distribution with a rectangular pattern. Next the well regions of the die are aligned, and the parts are bonded together using a Staystik thermoplastic. The pump unit is then mounted into a ceramic package over the hole drilled to permit fluid flow. Aluminum ribbon wire bonds are used to connect the pump electrodes to the package leads. Isolation of metallization and wires is achieved by filling the package well and coating the wires with polyimide.When a voltage is applied at the electrodes, ions are injected into the working fluid, such as an organic solvent, thus inducing flow. The second design has the die oriented ``back-to-back`` and bonded together with stayform. A ``back-to-back`` design will decrease the grid distance so that a smaller voltage is required for pumping. Preliminary results have demonstrated that this micro pump can achieved a pressure head of about 287 Pa with an applied voltage of 120 volts.

  17. Investigations of laser pumped gas cell atomic frequency standard

    NASA Technical Reports Server (NTRS)

    Volk, C. H.; Camparo, J. C.; Fueholz, R. P.

    1982-01-01

    The performance characteristics of a rubidium gas cell atomic frequency standard might be improved by replacing the standard rubidium discharge lamp with a single mode laser diode. Aspects of the laser pumped gas cell atomic clock studied include effects due to laser intensity, laser detuning, and the choice of the particular atomic absorption line. Results indicate that the performance of the gas cell clock may be improved by judicious choice of the operating parameters of the laser diode. The laser diode also proved to be a valuable tool in investigating the operation of the conventional gas cell clock. Results concerning linewidths, the light shift effect and the effect of isotopic spin exchange in the conventional gas cell clock are reported.

  18. Analysis of pumping schemes for high brightness diode-side-pumped lasers

    NASA Astrophysics Data System (ADS)

    Jabczynski, Jan K.; Kaskow, Mateusz; Zendzian, Waldemar; Kopczyński, Krzysztof; Puzewicz, Zbigniew

    2016-12-01

    Several schemes of side-pumping by novel, high brightness, 2D laser diode stacks were analyzed. The three most promising schemes were chosen, for which the optical set-ups have been designed, manufactured and preliminary characterized. The special, robust, compact cavity with high tolerances to misalignments, mechanical disturbances and shocks was designed. The analysis of temperature sensitivity of pump unit and laser was performed. In preliminary characterization 180 mJ of output energy with 2-mrad full divergence angle (parameter M2 5) in free running mode for 0.8-J of incident pump energy was demonstrated in such a compact cavity with 80% transmission of integrated output coupler. The main drawbacks in such design found in preliminary experiments are: low threshold of self-lasing due to high gain density and inhomogeneities in transverse beam profile. The strategy of mitigation of these drawbacks was discussed.

  19. Performance studies of diode-side-pumped CW Nd:YAG laser in copper coated optical pump cavity

    NASA Astrophysics Data System (ADS)

    Sundar, R.; Ranganathan, K.; Nath, A. K.

    2007-10-01

    This paper reports the performance studies of Nd:YAG rods with different diameters and doping concentration in the CW diode-side-pumped geometry. We have used p-polarized diodes to pump the active medium and we studied the performance of different rods in terms of thermal lensing, its fluorescence profile, power output, and M2 factor of the laser beam. We achieved a maximum of 378 W of output power for an input pump power of 757 W, which corresponds to optical conversion efficiency close to 50%. The slope efficiency of the system was 56.4%. These efficiencies are the highest reported to the best of our knowledge and we achieved with ∅ 4 mm×100 mm Nd:YAG rod at 1.1-at% doping.

  20. Research on fission induced plasmas and nuclear pumped lasers at the Los Alamos Scientific Laboratory

    NASA Technical Reports Server (NTRS)

    Helmick, H. H.

    1979-01-01

    A program of research on gaseous uranium and uranium plasmas is being conducted at The Los Alamos Scientific Laboratory under sponsorship of the National Aeronautics and Space Administration. The objective of this work is twofold: (1) to demonstrate the proof of principle of a gaseous uranium fueled reactor, and (2) pursue fundamental research on nuclear pumped lasers. The relevancy of the two parallel programs is embodied in the possibility of a high-performance uranium plasma reactor being used as the power supply for a nuclear pumped laser system. The accomplishments in the two above fields are summarized