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Sample records for laser optical pumping

  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. 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. Relaxation oscillations in optically pumped molecular lasers

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1980-01-01

    The observation of relaxation oscillations in both the (C-13)H3F and (C-12)H3F optically pumped lasers is reported. Expressions are derived for the oscillation frequency and its temperature and pressure dependences using a four-level rate equation model. Excellent agreement between measured frequencies and the theory presented is observed. Models are considered for using this phenomenon to determine the rotational and vibrational relaxation mechanisms of the laser gases.

  4. Optically pumped Na/sub 2/ laser

    SciTech Connect

    Kanorskii, S.I.; Kaslin, V.M.; Yakushev, O.F.

    1980-10-01

    A pulsed copper vapor laser emitting the 578.2 nm line was used as the pump source in achieving stimulated emission as a result of the electronic A/sup 1/..sigma../sup +//sub u/ to X/sup 1/..sigma../sup +//sub g/ transitions in the Na/sub 2/ molecule in the spectral range 0.765 to 0.804 ..mu... The average power of all the emission lines was 10 mW when the pulsed pump power was 150 W and the efficiency of conversion of the optical pump energy was about 3%. The pulse repetition frequency was 3.3 kHz. Violet diffuse radiation of the Na/sub 2/ molecules, generated by pumping with the copper vapor laser, was observed. The superradiance regime was found for some of the lines.

  5. 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.

  6. 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.

  7. Optical pumping of generalized laser active materials.

    PubMed

    Fry, F H

    1967-11-01

    Results are presented of a computer-based study on the rate of excitation in the active cores of two types of optically pumped lasers as a function of a number of parameters of the active core. The absorption bands of the active materials are generated by Lorentzian and Gaussian functions. The excitation rate of the active core is proportional to the width of the absorption band at all depths of penetration. The plots of excitation rate as a function of frequency show curves similar to line reversal spectra and emphasize the importance of excitation some distance from the center of the absorption band in the slab model. In the cylindrical model, this wing pumping is even more important due to focusing. The effect of refractive index on the excitation rate is also described. PMID:20062337

  8. Biological research by optically pumped far infrared lasers

    NASA Astrophysics Data System (ADS)

    Zhengyu, Mi

    1989-05-01

    The FIR breeding for paddy rice, black bean and wheat, the chlorophyll mutation of paddy rice induced by optically pumped FIR laser, etc., are presented. The results of SDS electrophoresis analysis of soluble proteins of Drosophita melanrgaster irradiated by optically pumped FIR laser are described and discussed.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  11. 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. PMID:27410591

  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. 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.

  14. Optical nonuniformities in nuclear-pumped cylindrical lasers

    SciTech Connect

    Mat'ev, V Yu; Borovkov, V V; Mel'nikov, S P

    2000-03-31

    The optical nonuniformities, formed as a result of the effect of the inhomogeneous energy deposition by the fission fragments irradiating the laser-active gas from thin uranium-containing layers, were calculated for cylindrical nuclear-pumped gas lasers. The results of the calculations agree with the experiment. (active media. lasers)

  15. Theoretical and experimental studies of optically pumped molecular gas lasers

    NASA Astrophysics Data System (ADS)

    Ratanavis, Amarin

    Optically pumped molecular gas lasers based on vibrational-rotational transitions in the infrared spectral region were studied experimentally and theoretically. A model was developed to predict the performance of such lasers and explore their potentials for energy and power scaling. This rate equation model was applied to explore the performance of a second-overtone (pulsed) and a first-overtone (CW) pumped HBr laser. Experimental improvements concerning temperature spectral tuning and frequency stabilization of a Nd:YAG laser that pumped HBr were accomplished. Lasing at 4 microns was demonstrated from such a system. We identified acetylene and hydrogen cyanide as potential laser gases that can be pumped with lasers emitting in the attractive telecommunication C band region at about 1.5 microns. Estimations and fluorescence measurements suggest the possibility of lasing in the 3 micron region. Lasing was demonstrated for the first time with a 5 ns pump pulse from an optical parametric oscillator using traditional cavities. The first gas filled hollow fiber laser based on population inversion was demonstrated with C2H2 and emission in the 3 micron region was observed. An analytical model indicates the possibility of CW lasing with small Stokes shift in both C2H 2 and HCN.

  16. Optically pumped pulsed Li/sub 2/ laser

    SciTech Connect

    Kaslin, V.; Yakushev, O.

    1982-02-01

    Pulsed lasing was obtained for the first time from Li/sub 2/ molecules by optical pumping with radiation from a pulsed copper vapor laser (578.2 nm, pulse repetition frequency 5 kHz). The laser transitions, with wavelengths in the range 867--907 nm, belong to the electronic A/sup 1/..sigma../sup +//sub u/--X/sup 1/..sigma../sup +//sub g/ system. With a pump power of 190 mW, an average output power of 8 mW was achieved with an efficiency for the conversion of the optical pumping energy of 7%. A number of Li/sub 2/ laser emission lines were observed in the superradiant regime.

  17. 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.

  18. Diode-Pumped Dye Laser Using a Tapered Optical Fiber

    NASA Astrophysics Data System (ADS)

    Patterson, Brian; Stofel, James; Myers, Elliot; Knize, Randy

    2015-05-01

    We describe the construction of a simple dye laser based on a single-mode optical fiber. Light from a 120-mW laser diode (λ = 520 nm) is launched into the fiber. The fiber is tapered to a diameter of approximately 1 μm and placed in Rhodamine 6G laser dye. The pump light interacts with the gain medium through the evanescent field outside the fiber causing stimulated emission, which couples back into the fiber. Mirrors on each end of the fiber provide the necessary feedback for lasing, and a grating is used to narrow the spectral output. We characterize the lasing threshold and output spectrum of the laser. This has been a good project for undergraduate students to learn about lasers and optics.

  19. Dye laser pumped, continuous-wave KTP optical parametric oscillators

    NASA Astrophysics Data System (ADS)

    Klein, M. E.; Scheidt, M.; Boller, K.-J.; Wallenstein, R.

    1998-06-01

    We report on dye-laser-pumped, continuous-wave (CW) KTiOPO4 (KTP) optical parametric oscillators (OPOs) with pump and idler resonant cavities. With a linear two-mirror cavity the pump power at threshold was 70 mW. The single-frequency signal and idler output wavelengths were tuned in the range of 1025 to 1040 nm and 1250 to 1380 nm by tuning the dye laser in the range of 565 to 588 nm. With a dual three-mirror cavity the threshold was 135 mW. Pumped by 500 mW of 578 nm radiation the 1040 nm single-frequency signal wave output power was 84 mW. Power and frequency stable operation with a spectral bandwidth of less than 9 MHz was obtained by piezo-electrically locking the length of the pump resonant cavity to the dye laser wavelength. Similar performance was achieved by placing the idler resonant OPO inside the resonator of the dye laser. With this system power stable and single-frequency operation was achieved with a spectral bandwidth of less than 11 MHz for the idler wave.

  20. Computing Temperatures In Optically Pumped Laser Rods

    NASA Technical Reports Server (NTRS)

    Farrukh, Usamah O.

    1991-01-01

    Computer program presents new model solving temperature-distribution problem for laser rods of finite length and calculates both radial and axial components of temperature distributions in these rods. Contains several self-checking schemes to prevent over-writing of memory blocks and to provide simple tracing of information in case of trouble. Written in Microsoft FORTRAN 77.

  1. 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.

  2. Dual-Wavelength Internal-Optically-Pumped Semiconductor Laser Diodes

    NASA Astrophysics Data System (ADS)

    Green, Benjamin

    Dual-wavelength laser sources have various existing and potential applications in wavelength division multiplexing, differential techniques in spectroscopy for chemical sensing, multiple-wavelength interferometry, terahertz-wave generation, microelectromechanical systems, and microfluidic lab-on-chip systems. In the drive for ever smaller and increasingly mobile electronic devices, dual-wavelength coherent light output from a single semiconductor laser diode would enable further advances and deployment of these technologies. The output of conventional laser diodes is however limited to a single wavelength band with a few subsequent lasing modes depending on the device design. This thesis investigates a novel semiconductor laser device design with a single cavity waveguide capable of dual-wavelength laser output with large spectral separation. The novel dual-wavelength semiconductor laser diode uses two shorter- and longer-wavelength active regions that have separate electron and hole quasi-Fermi energy levels and carrier distributions. The shorter-wavelength active region is based on electrical injection as in conventional laser diodes, and the longer-wavelength active region is then pumped optically by the internal optical field of the shorter-wavelength laser mode, resulting in stable dual-wavelength laser emission at two different wavelengths quite far apart. Different designs of the device are studied using a theoretical model developed in this work to describe the internal optical pumping scheme. The carrier transport and separation of the quasi-Fermi distributions are then modeled using a software package that solves Poisson's equation and the continuity equations to simulate semiconductor devices. Three different designs are grown using molecular beam epitaxy, and broad-area-contact laser diodes are processed using conventional methods. The modeling and experimental results of the first generation design indicate that the optical confinement factor of the

  3. DBR-free optically pumped semiconductor disk lasers

    NASA Astrophysics Data System (ADS)

    Yang, Zhou; Albrecht, Alexander R.; Cederberg, Jeffrey G.; Sheik-Bahae, Mansoor

    2015-03-01

    Optically pumped semiconductor disk lasers (SDLs) provide high beam quality with high average-power power at designer wavelengths. However, material choices are limited by the need for a distributed Bragg reflector (DBR), usually monolithically integrated with the active region. We demonstrate DBR-free SDL active regions, which have been lifted off and bonded to various transparent substrates. For an InGaAs multi-quantum well sample bonded to a diamond window heat spreader, we achieved CW lasing with an output power of 2 W at 1150 nm with good beam quality.

  4. 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.

  5. Nd:YAG end pumped by semiconductor laser arrays for free space optical communications

    NASA Technical Reports Server (NTRS)

    Sipes, D. L., Jr.

    1985-01-01

    Preliminary experimental results are reported for a diode-pumped Nd:YAG laser employing a tightly focused end-pump geometry. The resonator configuration is planoconcave, with the pumped end of the Nd:YAG rod being coated for high reflection at 1.06 microns. This geometry rectifies nearly all the inefficiencies plaguing side-pumped schemes. This laser is further considered as a candidate for optical communication over the deep space channel.

  6. 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.

  7. Dynamic model of optically pumped energy storage lasers

    SciTech Connect

    Kelly, J.H.

    1980-01-01

    A dynamic, complete model of optically pumped, energy storage laser media has been developed. This model predicts stored energy density and heat deposition as a function of both time and space. The relevant physics for solid state and liquid energy storage media has been considered including non-radiative loss mechanisms such as cooperative relaxation and multiphonon relaxation, and radiation loss mechanisms such as spontaneous emission and, for one particular geometry, amplified spontaneous emission. The model was applied to two energy storage media: xenon flashlamp pumped neodymium in glass and resonantly pumped (either xeF or dye) trivalent thulium in glass. For the nonradiative losses in both Nd and Tm systems classical electromagnetic cooperative relaxation theory was used. A concentration squared dependence is predicted and a 3/2 power dependence observed. The linear dependence on concentration of an impurity having a high energy vibration predicted by multiphonon decay theory was observed for Nd in phosphate glasses. This is strong evidence for stimulated phonon emission. Measured zero-doping fluorescence lifetimes were used in the model. Measured zero-doping fluorescence lifetimes were used in the model. Comparisons of predictions with experiment are presented. Finally, the model was applied to a large aperture, active-mirror configuration Nd:glass amplifier. This necessitated including the effect of ASE on the inversion density. Because of the unique geometry of the active mirror amplifier ASE could be approximated as a parasitic oscillation which clamps the inversion at a specific level determined from small signal gain measurements. Comparisons with the measured small signal performance of several active mirrors is shown and agreement is excellent. Consequently, the model has become an on-line design tool for optimization of large aperture amplifiers.

  8. Excited state Faraday anomalous dispersion optical filters based on indirect laser pumping.

    PubMed

    Yin, Longfei; Luo, Bin; Chen, Zhongjie; Zhong, Lei; Guo, Hong

    2014-02-15

    The direct pump method now used in excited state Faraday anomalous dispersion optical filters (ES-FADOFs) requires that the transition between the target and the ground state is an electric dipole allowed transition and that a laser that operates at the exact pump wavelength is available. This is not always satisfied in practice. An indirect laser pump method for ES-FADOF is proposed and experimentally realized. Compared with the commonly used direct pump method, this indirect pump method can reach the same performance using lasers at very different wavelengths. This method can greatly extend the wavelength range of FADOF and provide a novel scheme for ES-FADOF design. PMID:24562221

  9. Self-pumped optical phase conjugation with a sodium Raman laser.

    PubMed

    Donoghue, J; Cronin-Golomb, M; Kane, J S; Hemmer, P R

    1991-09-01

    We report self-pumped optical phase conjugation in which the pumps are self-induced as standing waves in a linear Raman laser. Self-pumped reflectivities approaching 5% are obtained for input intensities of 20 W/cm(2). This low optical input intensity combined with predicted submicrosecond response times suggests that the resonant Raman interaction may provide the basis for a promising new class of nonlinear-optical material. PMID:19776955

  10. 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.

  11. 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)

  12. Synchronous pumping of picosecond dye laser using high efficiency second harmonic generation from optical fibres

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Bernardin, J. P.; Macdonald, R. L.; Demouchy, G.

    1991-01-01

    The stable operation of a mode-locked dye laser synchronously pumped by the second harmonic of an Nd:YAG laser produced in an Nd codoped germanosilicate optical fiber is reported. The optical fiber preparation technique, which results in a second harmonic conversion efficiency of 2 percent, is described. This optical fiber SHG conversion efficiency is the highest reported to date using a continuous-wave mode-locked laser.

  13. Low-threshold terahertz molecular laser optically pumped by a quantum cascade laser

    NASA Astrophysics Data System (ADS)

    Pagies, A.; Ducournau, G.; Lampin, J.-F.

    2016-06-01

    We demonstrate a low-threshold, compact, room temperature, and continuous-wave terahertz molecular laser optically pumped by a mid-infrared quantum cascade laser. These characteristics are obtained, thanks to large dipole transitions of the active medium: NH3 (ammonia) in gas state. The low-power (<60 mW) laser pumping excites the molecules, thanks to intense mid-infrared transitions around 10.3 μm. The molecules de-excite by stimulated emission on pure inversion "umbrella-mode" quantum transitions allowed by the tunnel effect. The tunability of the quantum cascade laser gives access to several pure inversion transitions with different rotation states: we demonstrate the continuous-wave generation of ten laser lines around 1 THz. At 1.07 THz, we measure a power of 34 μW with a very low-threshold of 2 mW and a high differential efficiency of 0.82 mW/W. The spectrum was measured showing that the linewidth is lower than 1 MHz. To our knowledge, this is the first THz molecular laser pumped by a solid-state source and this result opens the way for compact, simple, and efficient THz source at room temperature for imaging applications.

  14. Characterization of thermo-optic effects in diode pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Jabczyński, Jan K.; Jaguś, Jarosław; Żendzian, Waldemar; Kwiatkowski, Jacek

    2005-08-01

    Review of thermo-optic effects in gain media of diode pumped lasers is presented. Methods of modeling and compensation of such effects are discussed. Results of characterization of end-pumped lasers by means of energetic and caustics measurements techniques are presented and discussed. Application of Wigner distribution method for characterization of aberrated laser beams is presented and discussed. Thermally induced astigmatism was observed for the anisotropic rods at high heat load.

  15. Nd:GGG disk laser with multipoint spatially periodic optical pumping

    NASA Astrophysics Data System (ADS)

    Guryev, D. A.; Nikolaev, D. A.; Tsvetkov, V. B.

    2016-04-01

    The results of the study of the output laser beam spatial characteristics of the Nd:Gd3Ga5O12 (Nd:GGG) disk laser with multipoint spatially periodic diode-pumping are presented. The presence of the optical coupling between the TEM00 lasing channels is demonstrated. The phase-locking of channels was realized due to partial overlapping of laser beams inside the pumped areas of the active element disk.

  16. 1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Alharthi, S. S.; Orchard, J.; Clarke, E.; Henning, I. D.; Adams, M. J.

    2015-10-01

    We report a room temperature optically pumped Quantum Dot-based Spin-Vertical-External-Cavity Surface-Emitting laser (QD Spin-VECSEL) operating at the telecom wavelength of 1.3 μm. The active medium was composed of 5 × 3 QD layers; each threefold group was positioned at an antinode of the standing wave of the optical field. Circularly polarized lasing in the QD-VECSEL under Continuous-Wave optical pumping has been realized with a threshold pump power of 11 mW. We further demonstrate at room temperature control of the QD-VECSEL output polarization ellipticity via the pump polarization.

  17. Mode locked Nd:YVO 4 laser with intracavity synchronously pumped optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Zavadilova, Alena; Kubeček, Václav; Čech, Miroslav; Hiršl, Petr; Jelínkova, Helena; Diels, Jean-Claude

    2006-02-01

    The motivation of this work is the development of laser sensor and gyroscope based on short pulse solid state ring laser. In comparison with regular ring laser containing the gain medium and saturable absorber, where counterpropagating pulses overlap, a ring synchronously pumped optical parametric oscillator, in which the pulse crossing point is controlled externally by the time of arrival of the pump pulses, is the ideal source for short pulse laser sensor. The optimum configuration is a synchronously pumped parametric oscillator inserted inside the optical resonator of the diode pumped mode-locked solid state laser. We are developing a such system, as a first step we have demonstrated operation of a diode pumped Nd:YVO 4 passively mode-locked laser using semiconductor saturable absorber with synchronously pumped intracavity optical parametric oscillator in linear configuration. The repetition rate of the pump laser was 132 MHz and the pulse duration of 15 ps. Parametric oscillator was based on 20 mm long Brewster cut single grating (with poling periode of 30.3 μm) periodically poled magnesium doped lithium niobate (MgO:PPLN) crystal. The temperature tuning of parametric luminescence from the crystal with peak wavelength at 1537 nm - 1550 nm for temperature variation from 30 °C to 57 °C was observed.

  18. Intracavity optical parametric oscillator pumped by an actively Q-switched Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Liu, Z. J.; Wang, Q. P.; Zhang, X. Y.; Liu, Z. J.; Wang, H.; Chang, J.; Fan, S. Z.; Ma, F. S.; Jin, G. F.

    2008-03-01

    A non-critically phase-matched KTiOPO4 optical parametric oscillator (OPO) intracavity pumped by a laser diode end-pumped acousto-optically Q-switchedNd:YAG laser is experimentally demonstrated. The highest average power is obtained at the pulse repetition rate (PRR) of around 15 kHz, which is different from the widely reported Nd:YVO4 laser pumped OPO in which the highest average power is obtained at a very high PRR, e.g. 80 kHz. With an incident laser diode power of 6.93 W and a pulse repetition rate of 15 kHz, an average signal power of 0.72 W is obtained with a peak power of 7.7 kW and an optical-to-optical conversion efficiency of 10.4%.

  19. Energy-transfer mechanisms in the CH3F-SF6 optically pumped laser

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1980-01-01

    The power of an optically pumped CH3F laser operating on the 496-micron line has been doubled with the addition of SF6 without any corresponding increase in pump absorption. It is suggested that a near-resonant energy transfer between CH3F and SF6 followed by SF6 deactivation is the mechanism responsible for the enhancement.

  20. Analysis of impact factors of output characteristics for optically pumped THz lasers

    NASA Astrophysics Data System (ADS)

    Huang, Renshuai; Meng, Qinglong; Guo, Xiaoyang; Zhang, Bin

    2016-08-01

    Optically pumped terahertz (THz) lasers as a reliable THz radiation sources have been widely used in THz application area. Considering the Doppler-broadened effects and the two-photon light shift effects, the physical model for the THz output power and the THz output frequency drift of optically pumped THz lasers has been established based on the rate equations. The main factors affecting THz laser output have been analyzed quantitatively. The results indicate that the THz output power increases with the increasing of the pump power, while decreases with the increasing of the pump frequency offset from the operating gas absorption centre. The THz output frequency drift is mainly caused by two-photon light shift when the pump offset is small, whereas Doppler-broadened becomes main factor if the pump frequency offset is relatively larger. Furthermore, the THz output frequency drift increases in proportion to the pump power. The stability of the THz output frequency can be enhanced and the THz output power can be improved by choosing pressure in the cavity reasonably, and the optimal working gas pressure range is 15-20 Pa. Stabilizing the pump laser frequency in the range of gas absorption centre, choosing reasonable working gas pressure in the THz cavity and the pump power can efficiently improve the performance of the THz laser output.

  1. Method for optical pumping of thin laser media at high average power

    DOEpatents

    Zapata, Luis E.; Beach, Raymond J.; Honea, Eric C.; Payne, Stephen A.

    2004-07-13

    A thin, planar laser material is bonded to a light guide of an index-matched material forming a composite disk. Diode array or other pump light is introduced into the composite disk through the edges of the disk. Pump light trapped within the composite disk depletes as it multi-passes the laser medium before reaching an opposing edge of the disk. The resulting compound optical structure efficiently delivers concentrated pump light and to a laser medium of minimum thickness. The external face of the laser medium is used for cooling. A high performance cooler attached to the external face of the laser medium rejects heat. Laser beam extraction is parallel to the heat flux to minimize optical distortions.

  2. Highly efficient cladding-pumped fibre laser based on an ytterbium-doped optical fibre and a fibre Bragg grating

    SciTech Connect

    Kurkov, Andrei S; Karpov, V I; Medvedkov, O I; Dianov, Evgenii M; Vasil'ev, Sergei A; Paramonov, Vladimir M; Protopopov, V N; Laptev, A Yu; Gur'yanov, A N; Umnikov, A A; Vechkanov, N I; Artyushenko, V G; Frahm, J

    1999-06-30

    Ytterbium-ion-doped double-clad optical fibres were developed. The differential quantum efficiency of a diode-pumped fibre laser, fabricated on the basis of such optical fibres with a fibre Bragg grating, was 90%. (lasers)

  3. Optical distortions in end-pumped zigzag slab lasers.

    PubMed

    Tang, Bing; Zhou, Tangjian; Wang, Dan; Li, Mi

    2015-04-01

    Ray tracing is performed to investigate the optical distortions in the end-pumped, zigzag slab. Optical path differences caused by temperature, slab deformation, and stress birefringence are calculated under uniform pumping; the results show a steep edge in the width dimension and a thermal lens with an effective focal length as short as several meters in the thickness dimension. Dependence of depolarization on total internal reflection phase retardance as well as the slab's cut angle is studied by the Jones matrix technique; results show that although at the pumping power of 10 kW, the mean depolarization of the 2.5  mm×30  mm×150.2  mm Nd:YAG slab is generally below 3%, and it increases rapidly with pumping power. Besides, for the 0°- or 60°-cut slab, an optimal phase retardance range of 5° to 13° exists, in which the depolarization loss can be lower than 0.5%. Finally, experiments on temperature and depolarization measurements verify the numerical results. PMID:25967178

  4. Optically pumped gas laser using electronic transitions in the NaRb molecule

    SciTech Connect

    Kaslin, V.M.; Yakushev, O.F.

    1983-12-01

    Laser superradiance was achieved for the first time as a result of an electronic transition in a diatomic heteronuclear molecule as a result of direct optical pumping. This superradiance was observed in the region of 670 nm due to a transition to the ground state X/sup 1/..sigma../sup +/ of the intermetallic alkali molecule NaRb pumped by radiation from a pulsed copper vapor laser (lambda = 510.6 nm).

  5. 1 W of 261 nm cw generation in a Pr 3+:LiYF 4 laser pumped by an optically pumped semiconductor laser at 479 nm

    NASA Astrophysics Data System (ADS)

    Ostroumov, Vasiliy; Seelert, Wolf

    2008-02-01

    The lack of blue pump sources for Pr-doped materials has been overcome with the recent progress in optically pumped semiconductor lasers (OPS) operating at 479 nm. The availability of reliable high power OPS pump lasers, makes Pr 3+-doped crystals ideal gain media for compact and efficient ultraviolet solid-state lasers with output power in the Watt range. We report on the scalability of a 522/261 nm Pr:YLF cw laser that is dual-end-pumped by two OPS lasers at 479 nm. At 9.6 W of incident pump power more than 4 W were obtained at 522 nm with a slope efficiency of 45%. Intracavity frequency doubling of 522 nm resulted in 1 Watt of cw UV output at 261 nm.

  6. Diode laser 87Rb optical pumping in an evacuated wall-coated cell

    NASA Technical Reports Server (NTRS)

    Lee, W. K.; Robinson, H. G.; Johnson, C. E.

    1984-01-01

    The evacuated wall coated sealed cell coupled with diode laser optical pumping offers a number of attractive potential advantages for use in Rb or Cs atomic frequency standards. An investigation of systematic effects is required to explore possible limitations of the technique. The use of diode laser optical pumping of 87 Rb in an evacuated wall coated sealed cell is presented. Experimental results/discussion to be presented include the signal strength and line broadening of the 0 - 0 hyperfine resonance as a function of light intensity for the D1 optical transitions (F - F prime) - (2 1 prime) and (2 - 2 prime), shift of the 0 - 0 hyperfine frequency as a function of laser intensity and de-tuning from optical resonance, and diode laser frequency stabilization techniques.

  7. Advances in optically pumped semiconductor lasers for blue emission under frequency doubling

    NASA Astrophysics Data System (ADS)

    Bai, Yanbo; Wisdom, Jeffrey; Charles, John; Hyland, Patrick; Scholz, Christian; Xu, Zuntu; Lin, Yong; Weiss, Eli; Chilla, Juan; Lepert, Arnaud

    2016-03-01

    Optically pumped semiconductor lasers (OPSL) offer the advantage of excellent beam quality, wavelength agility, and high power scaling capability. In this talk we will present our recent progress of high-power, 920nm OPSLs frequency doubled to 460nm for lightshow applications. Fundamental challenges and mitigations are revealed through electrical, optical, thermal, and mechanical modeling. Results also include beam quality enhancement in addressing the competition from diode lasers.

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

    SciTech Connect

    Fanning, J.J.; Kim, K.

    1984-04-01

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

  9. 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. PMID:24978537

  10. Performance of an array of plasma pinches as a new optical pumping source for dye lasers

    SciTech Connect

    Rieger, H.; Kim, K.

    1983-11-01

    A new optical pumping source consisting of an array of plasma pinches in the hypocycloidal-pinch geometry is employed to pump a variety of dye lasers. A dye cuvette is inserted along the symmetry axis of the plasma device such that it may be surrounded by the plasma pinch. The light from the plasma pinch is very intense and rich in ultraviolet, which makes it an attractive optical pumping source for dye lasers, particularly in the blue-green spectral region. Control of the plasma fluorescence is achieved by the choice of gas, its fill pressure, and the capacitor bank voltage and its stored energy. The rise time of this ''plasma flashlamp'' depends mainly on the gas species and the fill pressure. Output energy of approx.2 mJ per cm/sup 3/ of lasing medium, or 2 kW/cm/sup 3/ for a 1-..mu..s laser pulse, is obtained from rhodamine 6G, coumarin 480, LD 490, and coumarin 504 dyes. That both the coumarin 480 and rhodamine 6G lasers have the comparable output power is a direct proof that the present optical pumping source is more efficient than the commercial xenon flashlamps in pumping lasers in the blue-green spectral region.

  11. Femtosecond-precision synchronization of the pump-probe optical laser for user experiments at FLASH

    NASA Astrophysics Data System (ADS)

    Schulz, S.; Czwalinna, M. K.; Felber, M.; Predki, P.; Schefer, S.; Schlarb, H.; Wegner, U.

    2013-05-01

    In this paper, we present the long-term stable synchronization of the FLASH pump-probe Ti:sapphire oscillator to an optical reference with sub-10 fs (rms) timing jitter employing a balanced optical cross-correlator. The reference pulse train, transmitted over an actively transit time-stabilized 500m long fiber link, is generated by the FLASH master laser oscillator. This laser also provides the reference for several electron bunch arrival time monitors with sub-10 fs resolution, which in turn enables a longitudinal feedback reducing the electron bunch arrival time jitter to below 25 fs (rms). Combining the precise synchronization of the laser and the longitudinal accelerator feedback enabled a proof-of-principle pump-probe experiment at FLASH, ultimately showing a significant reduction of the timing jitter between the optical laser and the XUV pulses generated by the FEL, compared to the present standard operation.

  12. Random fiber laser of POSS solution-filled hollow optical fiber by end pumping

    NASA Astrophysics Data System (ADS)

    Hu, Zhijia; Zheng, Hongjun; Wang, Lijuan; Tian, Xiujie; Wang, Tongxin; Zhang, Qijin; Zou, Gang; Chen, Yang; Zhang, Qun

    2012-09-01

    Random fiber laser is obtained by end pumping a hollow optical fiber (HOF) filled with a dispersive solution of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles and laser dye pyrromethene 597 (PM597) in carbon disulfide (CS2), in which the concentration is 1.5×10-2 M for PM597 and 18.5 wt% for POSS, respectively. It is found that the pump light at the one end of the liquid core optical fiber (LCOF) can pass the whole length of LCOF because the POSS nanoparticles were dispersed in CS2 at a molecular level (1-3 nm) with high stability and without sedimentation. Above the threshold pump energy (˜0.81 mJ) the random fiber laser appears coherent and resonant feedback multimode lasing in the weakly scattering system. For the LCOF containing PM597 with the same concentration and no POSS nanoparticles, there occurs only ASE that can be observed under the same experimental condition.

  13. 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.

  14. Explosively pumped laser light

    SciTech Connect

    Piltch, M.S.; Michelott, R.A.

    1991-09-24

    This patent describes 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.

  15. Method and apparatus for efficient operation of an optically pumped laser

    NASA Technical Reports Server (NTRS)

    Sipes, Jr., Donald L. (Inventor)

    1994-01-01

    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 dichroci 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 of the same as a lasing medium makes the ring unidirectional. The questions raised in reexamination request No. 90/002,473, filed Oct. 10, 1991, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1,570(e).

  16. Application of principles of nonimaging optics to the construction of solid state laser pump cavities

    NASA Astrophysics Data System (ADS)

    Janevski, Zoran; Pantelic, Dejan V.

    1990-07-01

    In laser systems where it is impossible or impractical to use lamps and rod whose effective perimeters are matched, some elements of construction of cavities using nonimaging optical concentrators can be used to achieve improved designs in regard to efficiency and pumping uniformity.

  17. Spectrally narrow mid-infrared optically pumped lasers with partial surface DBR.

    PubMed

    Yang, Chi; Kaspi, Ron; Tilton, Michael L; Chavez, Joseph R; Ongstad, Andrew P; Dente, Gregory C

    2012-05-01

    An optically pumped mid-infrared edge-emitting laser is described, in which a Distributed Bragg Reflector grating partially occupies the surface, and provides spectral narrowing in a high power device. A quasi-continuous-wave power of 3 Watts is obtained at 3.6 µm that is contained within a spectral width of 7 nm. PMID:22565707

  18. Collisional narrowing in the optically pumped CH3OH and CH3F lasers

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1982-01-01

    The gain linewidth of the optically pumped CH3F laser is observed to narrow and rebroaden with the addition of He. In addition, the same effect is observed in the CH3OH laser with the addition of the polyatomic buffer gases SF6 and CS2. These results offer conclusive evidence of the Dicke narrowing phenomena in these inverted pure rotational transitions. The effect is observed using a high harmonic mixing technique in a Schottky barrier diode.

  19. Optically pumped semiconductor quantum dot disk laser operating at 1180 nm.

    PubMed

    Rautiainen, Jussi; Krestnikov, Igor; Butkus, Mantas; Rafailov, Edik U; Okhotnikov, Oleg G

    2010-03-01

    We demonstrate an optically pumped semiconductor disk laser using 39 layers of Stranski-Krastanov InGaAs quantum dots self-assembled during epitaxial growth on a monolithic GaAs/AlAs distributed Bragg reflector. The gain structure bonded to an intracavity diamond crystal heat spreader allows 1.75 W single-transverse-mode output (M(2)<1.2) with circular beam shape operating at 1180 nm in a disk laser geometry. PMID:20195322

  20. Carbon nanotube mode-locked optically-pumped semiconductor disk laser.

    PubMed

    Seger, K; Meiser, N; Choi, S Y; Jung, B H; Yeom, D-I; Rotermund, F; Okhotnikov, O; Laurell, F; Pasiskevicius, V

    2013-07-29

    An optically pumped semiconductor disk laser was mode-locked for the first time by employing a single-walled carbon nanotube saturable absorber. Stable passive fundamental mode-locking was obtained at a repetition rate of 613 MHz with a pulse length of 1.23 ps. The mode-locked semiconductor disk laser in a compact geometry delivered a maximum average output power of 136 mW at 1074 nm. PMID:23938653

  1. A 980 nm pseudomorphic single quantum well laser for pumping erbium-doped optical fiber amplifiers

    NASA Technical Reports Server (NTRS)

    Larsson, A.; Forouhar, S.; Cody, J.; Lang, R. J.; Andrekson, P. A.

    1990-01-01

    The authors have fabricated ridge waveguide pseudomorphic InGaAs/GaAs/AlGaAs GRIN-SCH SQW (graded-index separate-confinement-heterostructure single-quantum-well) lasers, emitting at 980 nm, with a maximum output power of 240 mW from one facet and a 22 percent coupling efficiency into a 1.55-micron single-mode optical fiber. These lasers satisfy the requirements on efficient and compact pump sources for Er3+-doped fiber amplifiers.

  2. Reliable Optical Pump Architecture for Highly Coherent Lasers Used in Space Metrology Applications

    NASA Technical Reports Server (NTRS)

    Erlig, Herman; Qiu, Yueming; Poberezhskiy, Ilya Y.; Meras, Patrick L.; Chang, Daniel H.; Wu, Yen-Hung

    2012-01-01

    The design and initial demonstration of a laser pump module (LPM) incorporating single-mode, grating-stabilized 808-nm diode lasers and a low-loss, high-port-count optical combiner are completed. The purpose of the developed LPM is to reliably pump an Nd:YAG crystal in the laser head (LH), which serves as the optical metrology source for SIMLite mission. Using the narrow-linewidth, single-mode laser diodes enables placement of the pump power near Nd adsorption peak, which enhances pumping efficiency. Grating stabilization allows for stable pump spectra as diode operating temperature and bias current change. The low-loss, high-port-count optical combiner enables efficient combining of tens of pumps. Overall, the module supports 5+ years of continuous operation at 2 W of pump power with reliability approaching 100 percent. The LPM consists of a laser diode farm (LDF) and a pump beam combiner (PBC). An array of 807- to 808-nm fiber-pigtailed laser diodes makes up the LDF. A Bragg grating in each 5- m core single-mode (SM) fiber pigtail acts to stabilize the lasing spectra over a range of diode operating conditions. These commercially available single-mode laser diodes can deliver up to 150 mW of optical power. The outputs from the multiple pumps in the LDF are routed to the PBC, which is a 37-input by 1-output all-fiber device. The input ports consist of 5- m core SM fiber, while the output port consists of 105- m core, 0.15 NA (numerical aperture) multi-mode (MM) fiber. The combiner is fabricated by fusing the 37 input fibers while simultaneously tapering the fused region. At the completion of this process, the MM fiber is spliced to the end of the adiabatic taper, and, for protection, the combiner is sheathed by a capillary tube. A compact and robust metal housing was designed and fabricated to protect the PBC during space deployment.

  3. Optical chopper Q-switching for flashlamp-pumped Er,Cr:YSGG lasers

    NASA Astrophysics Data System (ADS)

    Murphy, Francis J.; Arbabzadah, Emma A.; Bak, Alexey O.; Amrania, Hemmel; Damzen, Michael J.; Phillips, Chris C.

    2015-04-01

    We present a novel way of Q-switching a flashlamp-pumped, λ = 2.8 μm Er,Cr:YSGG laser, wherein a rotating polygon is used as an optical chopper. Single pulse energies of ~3.8 mJ were achieved with pulsewidths of ~305 ns. The scheme benefits from the simplicity of design, and, compared with other Q-switching methods, a reduction in losses and laser damage problems from intracavity components. We also investigate the optimization of the laser output through purging of the laser with nitrogen, and find a 29% increase in peak output energy.

  4. An optically pumped hydrogen iodide cascade laser operating in mid-infrared region

    NASA Astrophysics Data System (ADS)

    Ratanavis, Amarin

    2013-06-01

    In recent years, several activities have been toward optically pumped molecular gas lasers as mid-infrared coherent sources. These have been also motivated by the search of suitable laser media for Hollow-core Optical Fiber Gas Laser (HOFGLAS) and the novel beam combiner. To continue these challenge paths, an optically pumped Hydrogen Iodide (HI) laser is explored by using a comprehensive laser model. HI transitions in the communication band (1.5 μm) are attractive due to a potential mean to be excited by commercial available laser systems. Furthermore, its emission coverage in 5 micron region can be useful for many applications, for example, free-space communication and laser spectroscopy. In the laser model, 30 rotational states in each of the 8 vibrational states of HI are taken into account to allow molecular energy transfer processes such as rotational relaxation and vibrational relaxation. A HI laser under pulsed excitation on a second overtone transition with lasing cascade is possible. The complete lasing cascade originates from the terminal pumped state (vibrational state, V = 3) to the vibrational state, V = 2, from the vibrational state, V = 2 to the vibrational state, V = 1 and finally from the vibrational state, V = 1 to the vibrational ground state. For the full lasing cascade, the laser efficiencies can be approached to 70%. In addition, the lasing behavior of the gas pressure related to the molecular relaxation rates and pressure broadening effects is also investigated. Owing to exceptional frequency tuning properties, the laser output can be manipulated to desired frequencies.

  5. Mirrorless laser action from optically pumped dye-treated animal tissues

    NASA Astrophysics Data System (ADS)

    Siddique, Masood; Yang, Li.; Wang, Q. Z.; Alfano, R. R.

    1995-02-01

    Significant narrowing of the spectral and temporal profiles of emission radiation was observed from optically pumped chicken tissue and pig fat samples treated with rhodamine 640 dye solution. This narrowing of the emission response is attributed to mirrorless laser action from multiple scattering of radiation from within the excited dye regions of the animal tissue. These studies yield insight into the mechanisms of nonlinear optical interaction with continuously disordered heterogeneous active scattering structures of various sizes such as in animal tissues.

  6. Single-frequency diode-pumped lasers for free-space optical communication

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    Recent advances in laser technology for intersatellite optical communication systems are reviewed and illustrated with graphs and diagrams. Topics addressed include (1) single-frequency diode-pumped Nd:YAG lasers of monolithic ring configuration (yielding 368-384 mW output power with 1-W pumping), (2) injection chaining of up to 10 monolithic resonators to achieve redundancy and/or higher output power, (3) 2-kHz-linewidth 5-mW versions of (1) which are tunable over a 30-MHz range for use as local oscillators in coherent communication, (4) resonant external modulation and doubling or resonant phase modulation of diode-pumped lasers, and (5) wavelength multiplexing.

  7. Optically pumped type-II mid-infrared tunable distributed feedback lasers

    NASA Astrophysics Data System (ADS)

    He, Xiang

    Optically-pumped type-II mid-infrared index-coupled tunable distributed feed-back (DFB) semiconductor lasers have been developed to provide continuous-wave (CW) single longitudinal mode (SLM) operation with features including narrow spectral linewidth, high output power, good beam quality and wide continuous wavelength tunability for applications such as remote sensing or spectroscopy in the 3 to 5 microm midwave-infrared range of atmospheric transmission window. In the demonstration of this type of laser, a hyperbolically chirped grating was patterned using interferometric lithography (IL) with spherical wavefronts which was then transferred into the top clad of the slab waveguide epi-structure of the laser device. Wavelength tuning is achieved by translationally projecting pump stripe at different positions of this chirped grating on the laser device, thus different grating periods along the pump stripe at different pump positions select different lasing wavelengths. Primary results were acquired on one device of 4 mm in lateral dimension with continuously tuning range of about 80 nm centered at 3100 nm, single facet output power of 830 mW and typical spectral linewidth of 1.2 nm at 2.5xthreshold pumping. Fabry-Perot (F-P) interferometer was used as artificial target gas to demonstrate potential application of gas spectroscopy with this type of laser.

  8. Dynamics of a low-threshold optically pumped organic vertical-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Shayesteh, Mohammad Reza; Darvish, Ghafar

    2016-06-01

    We propose a low-threshold optically pumped organic vertical-cavity surface-emitting laser (OVCSEL). This device has the capability to apply both electrical and optical excitation. The microcavity structure consists of an organic light emitting diode with field-effect electron transport inserted in a high-quality factor double distributed Bragg reflector. The simulated quality factor of the microcavity is shown to be as high as 16,000. Also, we investigate threshold behaviour and the dynamics of the optically pumped OVCSEL with sub-picosecond pulses. Results from numerical simulation show that lasing threshold is 12.8 pJ/0.64 µJ cm-2 when pumped by sub-picosecond pulses of λ = 400 nm wavelength light.

  9. Optimisation of the parameters of a pump chamber for solid-state lasers with diode pumping by the optical boiler method

    NASA Astrophysics Data System (ADS)

    Kiyko, V. V.; Kislov, V. I.; Ofitserov, E. N.; Suzdal'tsev, A. G.

    2015-06-01

    A pump chamber of the optical boiler type for solid-state lasers with transverse laser diode pumping is studied theoretically and experimentally. The pump chamber parameters are optimised using the geometrical optics approximation for the pump radiation. According to calculations, the integral absorption coefficient of the active element at a wavelength of 808 nm is 0.75 - 0.8 and the relative inhomogeneity of the pump radiation distribution over the active element volume is 17% - 19%. The developed pump chamber was used in a Nd:YAG laser. The maximum cw output power at a wavelength of 1064 nm was ~480 W at the optical efficiency up to 19.6%, which agrees with theoretical estimates.

  10. Research on High-Intensity Picosecond Pump Laser in Short Pulse Optical Parametric Amplification

    NASA Astrophysics Data System (ADS)

    Pan, Xue; Peng, Yu-Jie; Wang, Jiang-Feng; Lu, Xing-Hua; Ouyang, Xiao-Ping; Chen, Jia-Lin; Jiang, You-En; Fan, Wei; Li, Xue-Chun

    2013-01-01

    A 527 nm pump laser generating 1.7 mJ energy with peak power of more than 0.12 GW is demonstrated. The theoretical simulation result shows that it has 106 gain in the picosecond-pump optical parametric chirped pulse amplification when the pump laser peak power is 0.1 GW and the intensity is more than 5 GW/cm2, and that it can limit the parametric fluorescence in the picosecond time scale of pump duration. The pump laser system adopts a master-oscillator power amplifier, which integrates a more than 30 pJ fiber-based oscillator with a 150 μJ regenerative amplifier and a relay-imaged four-pass diode-pump Nd glass amplifier to generate a 1 Hz top hat spatial beam and about 14 ps temporal Guassian pulse with <2% pulse-to-pulse energy stability. The output energy of the power amplifier is limited to 4 mJ for B-integral concern, and the frequency doubling efficiency can reach 65% with input intensity 10 GW/cm2.

  11. Collisional narrowing by polyatomic buffer gases in an optically pumped CH3F laser

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1980-01-01

    The gain linewidth of an optically pumped CH3F molecular laser is observed with the addition of various polyatomic buffer gases. This is interpreted as collisional (Dicke) narrowing. The measurement is the first observation of collisional narrowing by polyatomic buffer gases. It is also the first observation of the effect in a laser oscillator. The effect was observed using a heterodyne mixing technique at the laser emission frequency of 604 GHz. Collision cross sections for SF6-CH3F and CS2-CH3F are obtained.

  12. Wideband Raman-Pumped Wavelength-Swept Laser for Optical Coherence Tomography Application

    NASA Astrophysics Data System (ADS)

    Xu, Jianbing; Ou, Haiyan; Xu, Xing; Yang, Victor Xiao Dong; Chui, Po Ching; Kin-Yip Wong, Kenneth

    2013-06-01

    We demonstrate a new wavelength-swept laser based on fiber Raman amplification (FRA), achieved by multiplexing three different pump lasers at wavelengths of 1455, 1475, and 1509 nm. The obtained sweeping bandwidth was from 1526.1 to 1637.9 nm, which was as wide as 111.8 nm. It is the widest hitherto demonstrated based on FRA. We also present the use of this swept laser in the application scenario of optical coherence tomography (OCT). This scheme paves the way for fiber Raman amplification to be employed as a promising source for generating a wideband swept source for OCT application.

  13. Laser head for simultaneous optical pumping of several dye lasers. [with single flash lamp

    NASA Technical Reports Server (NTRS)

    Mumola, P. B.; Mcalexander, B. T. (Inventor)

    1975-01-01

    The invention is a laser head for simultaneous pumping several dye lasers with a single flash lamp. The laser head includes primarily a multi-elliptical cylinder cavity with a single flash lamp placed along the common focal axis of the cavity and with capillary tube dye cells placed along each of the other focal axes of the cavity. The inside surface of the cavity is polished. Hence, the single flash lamp supplies the energy to the several dye cells.

  14. Diode-pumped laser research

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, L.; Bufton, J. L.; Chan, K.

    1988-01-01

    The Laboratory for Oceans is currently working on the development of compact laser diode array (LD) pumped Nd:YAG lasers for use in space-based altimetry and ranging. Laser diode-array pumping technology promises to increase the electrical to optical efficiency of solid state lasers by an order of magnitude with a lifetime increase of nearly three orders of magnitude relative to today's conventional flashlamp-pumped laser systems. The small size, efficiency, and ruggedness make LD-pumped solid state lasers ideal for space based applications. In an in-house RTOP effort, a novel multiple-pass LD-pumped Nd:YAG laser amplifier was designed and tested to increase the 100 microjoule output pulse energy of the Lightwave laser oscillator. Preliminary results have yielded a round trip amplifier gain of about 15 percent using 7 microjoule LD-pump energy. As a parallel activity, funding was recently obtained to investigate the possible use of custom made fiber optic arrays to obtain an efficient optical coupling mechanism between the emitting laser diode-arrays and the target solid state laser material. Fiber optic coupling arrays would allow for the easy manipulation of the spatial emitting pattern of the diode pump sources to match either an end or side pumping laser configuration.

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

    PubMed

    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. PMID:23822352

  16. Mode structure in an optically pumped D sub 2 O far-infrared ring laser

    SciTech Connect

    Yuan, D.C. ); Soumagne, G.; Siegrist, M.R. )

    1990-02-01

    The mode structures in an optically pumped D {sub 2} O far-infrared ring laser and a corresponding linear resonator are compared in this paper. While single-mode operation can be obtained over the whole useful pressure range in the ring structure, this is only possible at pressures greater than 8 torr in the linear resonator case. A numerical model predicts quite well the pulse shape, pressure dependence, and influence of the resonator quality in the ring cavity.

  17. Optically pumped DBR-free semiconductor disk lasers.

    PubMed

    Yang, Zhou; Albrecht, Alexander R; Cederberg, Jeffrey G; Sheik-Bahae, Mansoor

    2015-12-28

    We report high power distributed Bragg reflector (DBR)-free semiconductor disk lasers. With active regions lifted off and bonded to various transparent heatspreaders, the high thermal impedance and narrow bandwidth of DBRs are mitigated. For a strained InGaAs multi-quantum-well sample bonded to a single-crystalline chemical-vapor deposited diamond, a maximum CW output power of 2.5 W and a record 78 nm tuning range centered at λ≈1160 nm was achieved. Laser operation using a total internal reflection geometry is also demonstrated. Furthermore, analysis for power scaling, based on thermal management, is presented. PMID:26831984

  18. 1.3-microm optically-pumped semiconductor disk laser by wafer fusion.

    PubMed

    Lyytikäinen, Jari; Rautiainen, Jussi; Toikkanen, Lauri; Sirbu, Alexei; Mereuta, Alexandru; Caliman, Andrei; Kapon, Eli; Okhotnikov, Oleg G

    2009-05-25

    We report a wafer-fused high power optically-pumped semiconductor disk laser operating at 1.3 microm. An InP-based active medium was fused with a GaAs/AlGaAs distributed Bragg reflector, resulting in an integrated monolithic gain mirror. Over 2.7 W of output power, obtained at temperature of 15 degrees C, represents the best achievement reported to date for this type of lasers. The results reveal an essential advantage of the wafer fusing technique over both monolithically grown AlGaInAs/GaInAsP- and GaInNAs-based structures. PMID:19466154

  19. Ultrafast pump-probe ellipsometry setup for the measurement of transient optical properties during laser ablation.

    PubMed

    Rapp, Stephan; Kaiser, Michael; Schmidt, Michael; Huber, Heinz P

    2016-08-01

    Ultrashort pulsed lasers offer a high potential in precise and efficient material processing and deep understanding of the fundamental laser-material interaction aspects is of great importance. The transient pulse reflectivity in conjunction with the transient absorption influences decisively the laser-material interaction. Direct measurements of the absorption properties by ultrafast time-resolved ellipsometry are missing to date. In this work, a unique pump-probe ellipsometry microscope is presented allowing the determination of the transient complex refractive index with a sub-ps temporal resolution. Measurements on molybdenum show ultrafast optical penetration depth changes of -6% to + 77% already within the first 10 ps after the laser pulse impact. This indicates a significant absorption variation of the pump pulse or subsequent pulses irradiating the sample on this timescale and paves the road towards a better understanding of pulse duration dependent laser ablation efficiency, double or burst mode laser ablation and lattice modifications in the first ps after the laser pulse impact. PMID:27505728

  20. Active lamp pulse driver circuit. [optical pumping of laser media

    NASA Technical Reports Server (NTRS)

    Logan, K. E. (Inventor)

    1983-01-01

    A flashlamp drive circuit is described which uses an unsaturated transistor as a current mode switch to periodically subject a partially ionized gaseous laser excitation flashlamp to a stable, rectangular pulse of current from an incomplete discharge of an energy storage capacitor. A monostable multivibrator sets the pulse interval, initiating the pulse in response to a flash command by providing a reference voltage to a non-inverting terminal of a base drive amplifier; a tap on an emitter resistor provides a feedback signal sensitive to the current amplitude to an inverting terminal of amplifier, thereby controlling the pulse amplitude. The circuit drives the flashlamp to provide a squarewave current flashlamp discharge.

  1. Review of optically pumped far-infrared laser lines from methanol isotopes

    NASA Astrophysics Data System (ADS)

    Pereira, D.; Moraes, J. C. S.; Telles, E. M.; Scalabrin, A.; Strumia, F.; Moretti, A.; Carelli, G.; Massa, C. A.

    1994-01-01

    The technique of optical pumping in polar molecules is the most efficient for Far-Infrared (FIR) laser generation, providing also a versatile and powerful tool for molecular spectroscopy in this spectral region. Methanol CH3OH and its isotopic varieties are the best media for optically pumped FIR laser, with over thousand lines observed, and the most widely used for investigations and applications. In this sense, it is important to organize and make available catalogues of FIR laser lines as complete as possible. Since the last critical reviews of 1984 on methanol and its isotopic varieties, over hundred papers have been published dealing with hundreds of new FIR laser lines. In 1992 a review of FIR laser lines from CH3OH was presented. In this communication we extend this work to the other methanol isotopes, namely CH3OD, CD3OH, CD3OD, (13)CH3OH, (13)CD3OH, (13)CD3OD, CH3OH-18, CH2DOH, CHD2OH and CH2DOD.

  2. 1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser

    SciTech Connect

    Alharthi, S. S. Henning, I. D.; Adams, M. J.; Orchard, J.; Clarke, E.

    2015-10-12

    We report a room temperature optically pumped Quantum Dot-based Spin-Vertical-External-Cavity Surface-Emitting laser (QD Spin-VECSEL) operating at the telecom wavelength of 1.3 μm. The active medium was composed of 5 × 3 QD layers; each threefold group was positioned at an antinode of the standing wave of the optical field. Circularly polarized lasing in the QD-VECSEL under Continuous-Wave optical pumping has been realized with a threshold pump power of 11 mW. We further demonstrate at room temperature control of the QD-VECSEL output polarization ellipticity via the pump polarization.

  3. Long-period gratings for the optimization of cladding-pumped microstructured optical fiber laser

    NASA Astrophysics Data System (ADS)

    Mescia, Luciano; Palmisano, Tommaso; Surico, Michele; Prudenzano, Francesco

    2010-12-01

    The design of a laser constituted by an ytterbium doped, double-cladding microstructured optical fiber (DCMOF) with an optimized optical coupler inscribed in the doped core region is illustrated. The coupler is constituted by a long-period grating (LPG) which increases the pump power transfer from the inner cladding modes towards the fundamental core mode. A home-made numerical code solving the coupled-mode equations and the rate equations is ad hoc developed to investigate the dependence of the fiber laser performance on the LPG parameters such as the grating period and the length. The simulations highlight that it is possible to transfer a lot of the total input pump power from the inner cladding modes towards the fundamental mode guided into the core, leading to a significant improvement of both the pump power absorption and the output signal power. Moreover, a reduction of the total length of the laser and a minimization of the length-dependent nonlinear effects can be obtained.

  4. Recent progress in the development of electrically and optically pumped dye vapor lasers

    NASA Astrophysics Data System (ADS)

    Marowsky, G.

    1980-01-01

    This paper reviews new results in the field of organic dye vapor lasers. Gain studies of the scintillator dye POPOP in liquid solution and in the vapor phase show that a dye vapor exhibits optical gain nearly as high as in the solution case under excitation by a N2 laser. Superradiant emission has been observed from both optically excited POPOP vapor and electron-beam excited vapor. The optimum operating conditions of an electron-beam pumped dye vapor-buffer gas system with high purity argon as buffer are reported. Potential energy transfer processes from the rare-gas buffer to the dye vapor are discussed. The metastable ionic species Ar2(+) has been identified as the most likely POPOP excitation source after intense electron pumping of the dense Ar buffer gas at typically 4-5 atm. An estimate of the conversion efficiency from electronic energy deposited in the Ar buffer to stimulated emission of the dye yields 5 percent. These results suggest that an efficient tunable electron beam pumped dye vapor laser is feasible.

  5. Study of Optimal Cavity Parameter in Optically Pumped D2O Gas Terahertz Laser

    NASA Astrophysics Data System (ADS)

    He, Zhihong; Zhang, Yuping; Zhang, Huiyun; Zhang, Qingmao; Liao, Jianhong; Zhou, Yongheng; Liu, Songhao; Luo, Xizhang

    2010-05-01

    Heavy water gas (D2O gas) which owns special structure property, can generate terahertz radiation by optically pumping technology, and its 385 μm wavelength radiation can be widely used. In this research, on the base of semi-classical density matrix theory, we set up a three-level energy system as its theoretical model, a TEA-CO2 laser 9R (22) output line (λ = 9.26 μm) acted as pumping source, D2O gas molecules were operating medium, the expressions of pumping absorption coefficient G p and Terahertz signal gain coefficient G s were deduced. It was shown that the gain of Terahertz signal was related with the energy-level parameters of operating molecules and some operating parameters of the Terahertz laser cavity, mainly including cavity length. By means of iteration method, the output power density of Terahertz pulse signal was calculated numerically. Changing the parameter of cavity length and keeping others steady, the relationship curve between the output power intensity (Is) of Terahertz pulse laser and the operating cavity length (L) was obtained. The curve showed that the power intensity (Is) increased with cavity length (L) in a certain range, but decreased when the length (L) exceeded some value because of the absorption effect, and there was an optimal cavity length for the highest output power. We used a grating tuned TEA-CO2 laser as pumping power and a sample tube of variable length in 70-160 cm as terahertz laser operating cavity to experiment. The results of theoretical calculation and experiment matched with each other, and it is helpful for miniaturizing terahertz laser volume to make it practical.

  6. Nd:LNA laser optical pumping of He-4 - Application to space magnetometers

    NASA Technical Reports Server (NTRS)

    Slocum, R. E.; Schearer, L. D.; Tin, P.; Marquedant, R.

    1988-01-01

    Results obtained from laser pumping in a helium magnetometer sensor, using a tunable Nd:LNA laser pumped with a high-power diode laser, are reported. It is shown that it was possible to observe both the Hanle signals and the n = 0, p = 1 parametric resonance by monitoring the pumping radiation passing through the cell. As the diode laser-pumped Nd:LNA laser was tuned through the D0, D1, and D2 transitions, three distinct resonance signals were produced. A comparison of the slope of lamp-pumped signals and laser-pumped D1 signals showed that, under otherwise identical conditions, the slope of the D1 laser signal was 45 times greater than the lamp-pumped signal.

  7. Nd:LNA laser optical pumping of He-4 - Application to space magnetometers

    NASA Astrophysics Data System (ADS)

    Slocum, R. E.; Schearer, L. D.; Tin, P.; Marquedant, R.

    1988-12-01

    Results obtained from laser pumping in a helium magnetometer sensor, using a tunable Nd:LNA laser pumped with a high-power diode laser, are reported. It is shown that it was possible to observe both the Hanle signals and the n = 0, p = 1 parametric resonance by monitoring the pumping radiation passing through the cell. As the diode laser-pumped Nd:LNA laser was tuned through the D0, D1, and D2 transitions, three distinct resonance signals were produced. A comparison of the slope of lamp-pumped signals and laser-pumped D1 signals showed that, under otherwise identical conditions, the slope of the D1 laser signal was 45 times greater than the lamp-pumped signal.

  8. Optical net gain measurement in n-type doped germanium waveguides under optical pumping for silicon monolithic laser.

    PubMed

    Okumura, Tadashi; Oda, Katsuya; Kasai, Junichi; Sagawa, Misuzu; Suwa, Yuji

    2016-05-01

    Silicon (Si) monolithic lasers are key devices in large-scale, high-density photonic integrated circuits. Germanium (Ge) is promising as an active layer due to the complementary metal-oxide semiconductor process compatibility with Si. A net optical gain from Ge is essential to demonstrate lasing operation. We fabricated Ge waveguides and investigated the n-type doping effect on the net optical gain. The estimated net gain of the n-Ge waveguide increased from -2200 to -500/cm, namely reducing loss, under optically pumped condition. PMID:27137529

  9. Optical pumping of the oxygen-iodine laser medium

    NASA Astrophysics Data System (ADS)

    Zagidullin, Marsel V.; Malyshev, Mikhail S.; Azyazov, Valeriy N.; Heaven, Michael C.

    2016-03-01

    The kinetics of the processes in an O2/I2/Ar/H2O gas flow that is irradiated simultaneously by light at wavelengths near 500 nm and 1315 nm, is considered. Radiation at 500 nm is used to photodissociate about 1% of the iodine molecules. The radiation at 1315 nm excites atomic iodine to the 2P1/2 state. Singlet oxygen molecules are produced via the energy exchange process I(2P1/2)+O2(X3Σ) → I(2P3/2) + O2(a1Δ), while I(2P1/2)+O2(a1Δ) energy pooling produces b1Σ oxygen. I(2P1/2) and O2(b1Σ) then accelerate the dissociation of I2. This active medium may reach ~40 W/cm-2 at an optical efficiency of 50%.

  10. Study of optimal gas pressure in optically pumped D IIO gas terahertz laser

    NASA Astrophysics Data System (ADS)

    He, Zhihong; Yao, Jianquan; Ren, Xia; Yang, Yang; Luo, Xizhang; Wang, Peng

    2008-03-01

    Heavy water vapor (D IIO gas) which owns special structure properties, can generate terahertz (THz) radiation by optically pumped technology, and its 385 μm wavelength radiation can be widely used. In this research, on the base of semi-classical density matrix theory, we set up a three-level energy system as its theoretical model, a TEA-CO II laser 9R (22) output line (λ=9.26 μm) acted as pumping source, D IIO gas molecules were operating medium, the expressions of pumping absorption coefficient G p and THz signal gain coefficient G s were deduced , It was shown that the gain of THz signal was related with the energy-level parameters of operating molecules and some operating parameters of the THz laser cavity, mainly including gas pressure, temperature etc.; By means of iteration method, the output power density of THz pulse signal was calculated numerically as its initial power density was known; Changing the parameter of gas pressure and keeping others steady, the relationship curve between the output power intensity (Is) of Tera-Hz pulse laser and the operating D IIO gas pressure (P) was obtained. The curve showed that the power intensity (Is) increased with gas pressure (P) in a certain range, but decreased when the pressure (P) exceeded some value because of the bottleneck effect, and there was an optimal gas pressure for the highest output power. We used a grating tuned TEA-CO II laser as pumping power and a sample tube of 97cm length as THz laser operating cavity to experiment. The results of theoretical calculation and experiment matched with each other.

  11. THz generation from optical rectification tilted-pulse-front pumping scheme with laser pulse focused to a line

    NASA Astrophysics Data System (ADS)

    Du, Hai-Wei; Hoshina, Hiromichi; Otani, Chiko

    2015-10-01

    In this study, we investigate THz pulses generated from optical rectification with tilted-pulse-front pumping scheme in which the laser beam is focused to a line in a stoichiometric lithium niobate (sLN) crystal. A cylindrical lens and a common lens are used to focus the pump laser beam to a line. The power law of THz pulse generation and the redshift induced from the sLN crystal are measured. The spectral shapes of the laser pulse are changed by inserting a filter into the pump laser beam, causing the THz radiation to change. The filter is a metal wire with 2 mm diameter. Experimental results show that this method can change the generated THz time waveforms but not their spectra. Such method offers a simple means to change and manipulate THz field generated from optical rectification with tiled-pulse-front pumping scheme.

  12. Rigrod laser-pumped-laser resonator model: II. Application to thin and optically-dilute laser media

    NASA Astrophysics Data System (ADS)

    Brown, D. C.

    2014-08-01

    In part I of this paper, and to set the foundation for this part II, we derived the resonator equations describing the normalized intensities, output power, gain, and extraction efficiency for a standard resonator incorporating two dielectric mirrors and a gain element. We then generalized the results to include an absorbing region representing a second laser crystal characterized by a small-signal transmission T0. Explicit expressions were found for the output power extracted into absorption by the second laser crystal and the extraction efficiency, and the limits to each were discussed. It was shown that efficient absorption by a thin or dilute second laser crystal can be realized in resonators in which the mirror reflectivities were high and in which the single-pass absorption was low, due to the finite photon lifetime and multi-passing of the absorbing laser element. In this paper, we apply the model derived in part I to thin or dilute laser materials, concentrating on a Yb, Er:glass intracavity pumped by a 946 nm Nd:YAG laser, a Yb, Er:glass laser-pumped intracavity by a 977 nm diode laser, and an Er:YAG laser-pumped intracavity to a 1530 nm diode laser. It is shown that efficient absorption can be obtained in all cases examined.

  13. Lamp pumped Nd:YAG laser. Space-qualifiable Nd:YAG laser for optical communications

    NASA Technical Reports Server (NTRS)

    Ward, K. B.

    1973-01-01

    Results are given of a program concerned with the design, fabrication, and evaluation of alkali pump lamps for eventual use in a space qualified Nd:YAG laser system. The study included evaluation of 2mm through 6mm bore devices. Primary emphasis was placed upon the optimization of the 4mm bore lamp and later on the 6mm bore lamp. As part of this effort, reference was made to the Sylvania work concerned with the theoretical modeling of the Nd:YAG laser. With the knowledge gained, a projection of laser performance was made based upon realistic lamp parameters which should easily be achieved during following developmental efforts. Measurements were made on the lamp performance both in and out of the cavity configuration. One significant observation was that for a constant vapor pressure device, the spectral and fluorescent output did not vary for vacuum or argon environment. Therefore, the laser can be operated in an inert environment (eg. argon) with no degradation in output. Laser output of 3.26 watts at 430 watts input was obtained for an optimized 4mm bore lamp.

  14. Precision measurement of the nuclear polarization in laser-cooled, optically pumped 37K

    NASA Astrophysics Data System (ADS)

    Fenker, B.; Behr, J. A.; Melconian, D.; Anderson, R. M. A.; Anholm, M.; Ashery, D.; Behling, R. S.; Cohen, I.; Craiciu, I.; Donohue, J. M.; Farfan, C.; Friesen, D.; Gorelov, A.; McNeil, J.; Mehlman, M.; Norton, H.; Olchanski, K.; Smale, S.; Thériault, O.; Vantyghem, A. N.; Warner, C. L.

    2016-07-01

    We report a measurement of the nuclear polarization of laser-cooled, optically pumped 37K atoms which will allow us to precisely measure angular correlation parameters in the {β }+-decay of the same atoms. These results will be used to test the V ‑ A framework of the weak interaction at high precision. At the Triumf neutral atom trap (Trinat), a magneto-optical trap confines and cools neutral 37K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of \\bar{P}=0.9913+/- 0.0009, which is significantly more precise than previous measurements with this technique. Since our current measurement of the β-asymmetry has 0.2 % statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to \\lt 0.1 % , allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics.

  15. Ten years optically pumped semiconductor lasers: review, state-of-the-art, and future developments

    NASA Astrophysics Data System (ADS)

    Kannengiesser, Christian; Ostroumov, Vasiliy; Pfeufer, Volker; Seelert, Wolf; Simon, Christoph; von Elm, Rüdiger; Zuck, Andreas

    2010-02-01

    Optically Pumped Semiconductor Lasers - OPSLs - have been introduced in 2001. Their unique features such as power scalability and wavelength flexibility, their excellent beam parameters, power stability and reliability opened this pioneering technology access to a wide range of applications such as flow cytometry, confocal microscopy, sequencing, medical diagnosis and therapy, semiconductor inspection, graphic arts, forensic, metrology. This talk will introduce the OPSL principles and compare them with ion, diode and standard solid state lasers. It will revue the first 10 years of this exciting technology, its current state and trends. In particular currently accessible wavelengths and power ranges, frequency doubling, ultra-narrow linewidth possibilities will be discussed. A survey of key applications will be given.

  16. 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.

  17. Optically pumped GaN vertical cavity surface emitting laser with high index-contrast nanoporous distributed Bragg reflector.

    PubMed

    Lee, Seung-Min; Gong, Su-Hyun; Kang, Jin-Ho; Ebaid, Mohamed; Ryu, Sang-Wan; Cho, Yong-Hoon

    2015-05-01

    Laser operation of a GaN vertical cavity surface emitting laser (VCSEL) is demonstrated under optical pumping with a nanoporous distributed Bragg reflector (DBR). High reflectivity, approaching 100%, is obtained due to the high index-contrast of the nanoporous DBR. The VCSEL system exhibits low threshold power density due to the formation of high Q-factor cavity, which shows the potential of nanoporous medium for optical devices. PMID:25969197

  18. 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.

  19. 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.

  20. a Mathematical Model of the Dynamics of AN Optically Pumped Codoped Solid State Laser System

    NASA Astrophysics Data System (ADS)

    Wangler, Thomas Gerard

    1990-01-01

    This is a study of a mathematical model for the dynamics of an optically pumped codoped solid state laser system. The model comprises five first order, nonlinear, coupled, ordinary differential equations which describe the temporal evolution of the dopant electron populations in the laser crystal as well as the photon density in the laser cavity. The analysis of the model is conducted in three parts. First, a detailed explanation of the modeling process is given and the full set of rate equations is obtained. The model is then simplified and certain qualitative properties of the solution are obtained. In the second part the equilibrium solutions are obtained and a local stability analysis is performed. The system of rate equations is solved numerically and the effects, on the solution, of varying physical parameters is discussed. Finally, the third part addresses the oscillatory behavior of the system by "tracking" the eigenvalues of the linearized system. A comparison is made between the frequency of oscillations in the linear and nonlinear system. Pertinent physical processes--back transfer, Q-switching, and up -conversion--are then examined. The laser system consists of thulium and holmium ions in a YAG crystal operated in a Fabrey-Perot cavity. All computer programs were written in FORTRAN and currently run on either an IBM-PC or a DEC VAX 11/750.

  1. A mathematical model of the dynamics of an optically pumped codoped solid-state laser system

    SciTech Connect

    Wangler, T.G.

    1990-01-01

    This is a study of a mathematical model for the dynamics of an optically pumped codoped solid state laser system. The model comprises five first order, nonlinear, coupled, ordinary differential equations which describe the temporal evolution of the dopant electron populations in the laser crystal as well as the photon density in the laser cavity. The analysis of the model is conducted in three parts. First, a detailed explanation of the modeling process is given and the full set of rate equations is obtained. The model is then simplified and certain qualitative properties of the solution are obtained. In the second part the equilibrium solutions are obtained and local stability analysis is performed. The system of rate equations is solved numerically and the effects, on the solution, of varying physical parameters is discussed. Finally, the third part addresses the oscillatory behavior of the system by tracking the eigenvalues of the linearized system. A comparison is made between the frequency of oscillations in the linear and nonlinear system. Pertinent physical processes - back transfer, Q-switching, and up-conversion - are then examined. The laser system consists of thulium and holmium ions in YAG crystal operated in a Fabrey-Perot cavity. All computer programs were written in FORTRAN and currently run on either an IBM-PC or a DEC VAX 11/750.

  2. High power mid-infrared continuous-wave optical parametric oscillator pumped by fiber lasers

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojun; Li, Xiao; Liu, Lei; Shang, Yaping

    2015-02-01

    3~5μm mid-infrared laser has many important applications, such as gas detection, spectral analysis, remote sensing, medical treatment, and also in the military laser radar, infrared countermine, and so on. Optical parametric oscillator (OPO) is an efficient way to generate laser in this wavelength range, which has attracted the eyes of many people. In this paper, the recent development of mid-infrared OPO is overviewed. Meanwhile, detailed introduction on our recent work is given. Maximum idler output power of 34.2W at center wavelength of 3.35μm was obtained, to our knowledge, which is the new power record of the international public reporting for the continue-wave (CW) mid-infrared OPO. It is worth mentioning that the pump source, the quasi single-frequency (SF) narrow line width fiber laser, was also developed by our groups. According to the current status of research, some solutions is proposed in order to achieve higher power, narrower line width, and compact volume mid-infrared OPO in a wide tunable range.

  3. Optically pumped ultraviolet and infrared lasers driven by exploding metal films and wires

    SciTech Connect

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

    1983-01-01

    The 342-nm molecular iodine and 1315-nm atomic iodine lasers have been optically pumped by intense light from exploding-metal-film and exploding-wire discharges. Brightness temperatures for the exploding-film discharges were approx. 25,000 K and for the wire discharges were approx. 30,000 K. For the I/sub 2/ laser the 3.5-cm-diameter by 40-cm-long pumped volume lies adjacent to the wire or film of the same length. Pressures of 1 to 6 torr I/sub 2/ and 1 to 3 atm SF, CF/sub 4/, or Ar were used in the stainless-steel cell. Using 20-..mu..F capacitance charged to 40 kV, a 0.25-mm tungsten wire, 3-torr I/sub 2/, and a 2-atm SF/sub 6/, an energy of 2 J was obtained from the laser in a pulse of 8-..mu..s duration. The specific output energy was 7 J/l. Substitution of a cylindrical Al film for the wire, under otherwise similar conditions, led to a X10 output energies and efficiencies were obtained with similar input energy. An output pulse of 12 J and 12-..mu..s duration was measured for a specific output energy of 18 J/l. A laser energy of 110 J in a 20-us-long pulse has been measured from atomic iodine using a wire discharge along the axis of a larger cell. The active volume available was 20 cm in diameter and 80 cm in length. Input energy was 32 kJ. In similar measurements using a cylindrical Al film for discharge initiation, the measured output energy was 40 J.

  4. Laser Cooling and Trapping of Neutral Mercury Atoms Using an Optically-Pumped External-Cavity Semiconductor Laser

    NASA Astrophysics Data System (ADS)

    Paul, Justin; Lytle, Christian; Jones, R. Jason

    2011-05-01

    The level structure of the Hg atom is similar to other alkaline earth-like atoms, offering the possibility to realize an extremely high quality resonance factor (Q) on the ``clock'' transition (1S0- 3P0) when confined in an optical lattice at the Stark-shift free wavelength. A key feature of the Hg system is the reduced uncertainty due to black-body induced Stark shifts, making it an interesting candidate as an optical frequency standard. One challenge to laser-cooling neutral Hg atoms is finding a reliable source for cooling on the 1S0-3 P1 transition at 253.7 nm. We employ an optically pumped semiconductor laser (OPSEL) operating at 1015 nm, whose frequency is quadrupled in two external-cavity doubling stages to generate over 120 mW at 253.7 nm. With this new laser source we have trapped Hg199 from a background vapor in a standard MOT. We trap up to 2 × 106 atoms with a 1/e2 radius of our MOT of ~310 microns, corresponding to a density of 1.28 × 1010 atoms/cm3. We report on the progress of our Hg system and plans for precision lattice-based spectroscopy of the clock transition. Support for this work is supported through the U.S. Air Force Office of Scientific Research (AFOSR) through grant no. FA9550-09-1-0563.

  5. 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.

  6. 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.

  7. 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

  8. High-power CW diode-laser-array-pumped solid-state lasers and efficient nonlinear optical frequency

    NASA Astrophysics Data System (ADS)

    Shine, Robert J.; Byer, Robert L.

    1994-01-01

    During the interim period of this bridging contract, we have continued to work on the development of high-power cw diode-laser-array-pumped solid-state lasers. Towards that end, we have built lower power lasers in order to test individual components needed for the high-power laser, specifically we have built a 1 watt ring laser and a 5 watt slab laser. The 1 watt laser was used to study the injection locking process while assembling all the necessary electronics. We have demonstrated that it is possible to injection lock a diode-pumped laser using a single piezo-mounted mirror due to the lower intrinsic laser noise compared to an arc-lamp-pumped system. This allows us to optimize the injection locking servo loop and build a more stable locking system. The 5 watt laser was used as a test bed to find a practical way to mount the slab laser while minimizing the losses that occur at the total internal reflection (TIR) points in the slab. After trying many different means of protecting the TIR surfaces, we found that a new product from DuPont, Teflon AF 1600, has all the properties needed to provide a low loss protective coating. Using this material, the laser had a cavity loss of below 2%, which allowed for efficient operation of the laser in a side-pumped design. This laser produced 5 watts of output power with a slope efficiency near 20%.

  9. Dual Femtosecond TITANIUM:SAPPHIRE Laser for Ultrafast Optical Sampling Two-Color Pump/probe Studies.

    NASA Astrophysics Data System (ADS)

    Luo, Ningyi Daniel

    A pair of self-synchronous Ti:Sapphire lasers have been setup for two-color pump/probe detection in the sub-picosecond time regime. The two 75 femtosecond self -mode-locked Ti:Sapphire lasers are operated asynchronously at slightly different repetition rates to provide continuously varying dynamic delay times. They are tunable at 700-890 nm. The shorter wavelength pulses from one laser are used as a pump source, while the longer wavelength pulses are used as a probe. The sum-frequency pulses generated by the cross-correlation of the two laser pulses are used to define the "time-zero" position and trigger the pump/probe process. The experiment is triggered at the difference frequency, and the signal can be averaged many times allowing a weak signal to build up. Dual-time scale is involved with the interpretation of the signal, which allows the experiment to be carried on the real time scale and the signal to be recorded on a much reduced equivalent time scale. Excited state lifetime measurement of laser HITCI has proven that this technology is practically feasible. Several advantages have been seen: (1) independent wavelength tunability of the pump and probe lasers; (2) variable femto- to nano -second pump/probe time delay; (3) fast (mu s-ms) data collection time; (4) compact optical layout, without the need for optical delay lines and modulators, and thus, simple optical alignment. This study sheds light on the development of a novel compact high speed optical instrument.

  10. Nonlinear optical characterization of cluster dynamic in water in oil microemulsion by a pump probe laser beam technique

    NASA Astrophysics Data System (ADS)

    Vicari, L.

    2002-11-01

    We present a new pump probe laser beams configuration for the nonlinear optical characterization of microemulsions. We detect the variation of the on-axis optical intensity of the probe beam as generated by the concentration profile induced in an optically thin film of microemulsion by the pump beam. A mathematical model has been introduced to describe the phenomenon. The technique allows the determination of both Kerr-like optical nonlinearity and time constants and, therefore, it gives information both on cluster dimension and their shape. We discuss its application to WAD (water/AOT/decane, where AOT denotes sodium-bis-di-ethyl-sulfosuccinate) with the application of a strong electric field of optical source. Comparison between theoretical predictions and experimental results confirms the presence of giant optical nonlinearity in the absence of turbidity divergence. Chainlike shape of clusters, of the kind already reported with the application of strong electric field, could justify this result.

  11. Nonlinear optical characterization of cluster dynamic in water in oil microemulsion by a pump probe laser beam technique.

    PubMed

    Vicari, L

    2002-11-01

    We present a new pump probe laser beams configuration for the nonlinear optical characterization of microemulsions. We detect the variation of the on-axis optical intensity of the probe beam as generated by the concentration profile induced in an optically thin film of microemulsion by the pump beam. A mathematical model has been introduced to describe the phenomenon. The technique allows the determination of both Kerr-like optical nonlinearity and time constants and, therefore, it gives information both on cluster dimension and their shape. We discuss its application to WAD (water/AOT/decane, where AOT denotes sodium-bis-di-ethyl-sulfosuccinate) with the application of a strong electric field of optical source. Comparison between theoretical predictions and experimental results confirms the presence of giant optical nonlinearity in the absence of turbidity divergence. Chainlike shape of clusters, of the kind already reported with the application of strong electric field, could justify this result. PMID:15010903

  12. SOLITONS AND OPTICAL FIBERS: Self-Q-switched ytterbium-doped cladding-pumped fibre laser

    NASA Astrophysics Data System (ADS)

    Grukh, Dmitrii A.; Kurkov, Andrei S.; Razdobreev, I. M.; Fotiadi, A. A.

    2002-11-01

    A self-Q-switched ytterbium-doped double-clad fibre laser is described. A samarium-doped fibre is used as a filter for protecting a pump source. A fibre coupler is employed to obtain a nonlinear feedback. The mechanism of pulse formation in the laser is considered, and the dependence of its output pulse on the coupler parameters is studied.

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  16. Off-axis coherently pumped laser

    NASA Technical Reports Server (NTRS)

    Koepf, G. A. (Inventor)

    1984-01-01

    A coherently optically pumped laser system is described. A pump laser beam propagates through a laser medium contained in a degenerate cavity resonator in a controlled multiple round trip fashion in such a way that the unused pump beam emerges from an injection aperture at a different angle from which it enters the resonator. The pump beam is angularly injected off of the central axis of the resonator body whereupon the pump beam alternately undergoes spreading and focusing while pumping the laser medium by a process of resonant absorption. The emergent pump beam can also be used as a second pump beam source by being reinjected back into the cavity or it can be used for pumping another laser.

  17. Raman-pumped Fourier-domain mode-locked laser: analysis of operation and application for optical coherence tomography.

    PubMed

    Klein, Thomas; Wieser, Wolfgang; Biedermann, Benjamin R; Eigenwillig, Christoph M; Palte, Gesa; Huber, Robert

    2008-12-01

    We demonstrate a Raman-pumped Fourier-domain mode-locked (FDML) fiber laser and optical coherence tomography imaging with this source. The wavelength sweep range of only 30 nm centered around 1550 nm results in limited axial resolution, hence a nonbiological sample is imaged. An output power of 1.9 mW was achieved at a sweep rate of 66 kHz and a maximum ranging depth of ~2.5 cm. Roll-off characteristics are found to be similar to FDML lasers with semiconductor optical amplifiers as gain media. The application of Raman gain also enables unperturbed cavity ring-down experiments in FDML lasers for the first time, providing direct access to the photon lifetime in the laser cavity. Good agreement with nonswept cw operation is proof of the stationary operation of FDML lasers. PMID:19037436

  18. Double resonance fequency light shift compensation in optically oriented laser-pumped alkali atoms

    SciTech Connect

    Baranov, A. A. Ermak, S. V.; Sagitov, E. A.; Smolin, R. V.; Semenov, V. V.

    2015-09-15

    The contributions of the vector and scalar components to the magnetically dependent microwave transition frequency light shift are analyzed and the compensation of these components is experimentally demonstrated for the {sup 87}Rb atoms optically oriented by a laser tuned to the D{sub 2} line of the head doublet. The Allan variance is studied as a function of the averaging time for a tandem of optically pumped quantum magnetometers (OPQMs), one of which is based on a low-frequency spin oscillator while another is based on a quantum microwave discriminator with a resonance frequency that corresponds to magnetically dependent transitions between HFS sublevels with the extremal value of the magnetic quantum number. It is shown that the compensation of the scalar and vector components of the light shift in OPQMs reduces the Allan variance at averaging times that exceed hundreds of seconds compared to a quantum discriminator based on the magnetically independent 0–0 transition. In this case, the minimal Allan variance in OPQMs at the end resonance is achieved at considerably longer averaging times than in the case of the quantum discriminator that is tuned to the 0–0 transition frequency.

  19. 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.

  20. 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.

  1. Analytical model of optical path difference in an end-pumped Yb:YAG thin-disk laser with nonuniform pumping light.

    PubMed

    Zhu, Guangzhi; Zhu, Xiao; Dai, Zhongxiong; Wang, Zexiong; Zhu, Changhong

    2015-04-01

    An analytical model of the thermal effect and optical path difference (OPD) of a thin-disk laser is developed by an arbitrary form pumping spot. Based on the analytical model, the distribution of temperature, stress, and strain can be derived using a super-Gaussian form pumping spot. The total OPD caused by temperature gradient, axial thermal strain, thermal strain-induced birefringence, and deformation of the thin-disk crystal is discussed for different super-Gaussian factors and is separated into spherical and aspherical parts. The analytical results show that the aspherical part of the OPD is the main reason leading to the decrease of the laser beam quality and it is closely related to super-Gaussian factors, which are very useful for thin-disk laser design and evaluation. PMID:25967218

  2. 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.

  3. Optical parameteric oscillation in MgO:LiNbO sub 3 driven by a diode pumped single frequencey q-switched laser

    SciTech Connect

    Gerstenberger, D.C.; Tye, G.E.; Wallace, R.W. )

    1990-01-01

    The authors report how they have obtained optical parametric oscillation tunable over the 940--1220 nm spectral region from a monolithic magnesium oxide doped lithium niobate ring resonator. The monolithic OPO was pumped by the 532 nm second harmonic of a diode laser pumped single frequency {ital Q}-switched Nd:YAG laser. The exceptional frequency and amplitude stability of the single frequency pump source provided stable OPO output pulses.

  4. Simple and efficient method of spin-polarizing a metastable helium beam by diode laser optical pumping

    NASA Astrophysics Data System (ADS)

    Granitza, B.; Salvietti, M.; Torello, E.; Mattera, L.; Sasso, A.

    1995-08-01

    Diode laser optical pumping to produce a highly spin-polarized metastable He beam to be used in a spin-polarized metastable atom deexcitation spectroscopy experiment on magnetized surfaces is described. Efficient pumping of the beam is performed by means of an SDL-6702 distributed Bragg reflector diode laser which yields 50 mW of output power in a single longitudinal mode at 1083 nm, the resonance wavelength for the 23 S→23 P0,1,2 (D0, D1, and D2) transitions of He*. The light is circularly polarized by a quarter-wave plate, allowing easy change of the sense of atomic polarization. The laser frequency can be locked to the atomic transition for several hours by phase-sensitive detection of the saturated absorption signal in a He discharge cell. Any of the three transitions of the triplet system can be pumped with the laser but the maximum level of atomic polarization of 98.5% is found pumping the D2 line.

  5. Development of stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping

    SciTech Connect

    Liu, Bo; Tong, Xin; Jiang, Chenyang; Brown, Daniel R.; Robertson, Lee

    2015-06-05

    In this study, we developed a stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping. An optimized external cavity equipped with an off-the-shelf volume holographic grating narrowed the spectral line-width of a 100 W high-power diode laser and stabilized the laser spectrum. The laser spectrum showed a high side mode suppression ratio of >30 dB and good long-term stability (center wavelength drifting within ±0.002 nm during 220 h of operation). Finally, our laser is delivered by a multimode fiber with power ~70 W, center wavelength of 794.77 nm, and spectral bandwidth of ~0.12 nm.

  6. Intracavity optical parametric oscillator based on GTR-KTP driven by laser-diode end-pumped Q-switched Nd:YVO 4 laser

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Fei; Zhang, Bai-Tao; Huang, Hai-Tao; He, Jing-Liang; Xu, Jin-Long; Zhao, Shuang; Yang, Xiu-Qin; Qiu, Gang; Liu, Zong-Kai

    2010-07-01

    An efficient, eye-safe, high-repetition-rate, single-resonant intracavity optical parameter oscillator, driven by a laser-diode (LD) end-pumped acousto-optically Q-switched Nd:YVO 4 laser, based on high gray-trace resistance KTiPO 4 (GTR-KTP), was demonstrated. With a pump power of 13.8 W and frequency repetition rate of 40 kHz, the maximum power of 1.72 W with pulse width of 2.09 ns at signal wavelength 1572 nm is obtained. The corresponding peak power and single pulse energy is calculated to be 21 kW and 43 μJ, respectively. And the conversion efficiency from incident pump power at 808 nm to output power at signal wavelength 1572 nm is about 12.5%. The output instability is measured only to be 1% within 1 h.

  7. 2.6 W optically-pumped semiconductor disk laser operating at 1.57-microm using wafer fusion.

    PubMed

    Rautiainen, Jussi; Lyytikäinen, Jari; Sirbu, Alexei; Mereuta, Alexandru; Caliman, Andrei; Kapon, Eli; Okhotnikov, Oleg G

    2008-12-22

    We report a wafer fused high power optically pumped semiconductor disk laser incorporating InP-based active medium fused to a GaAs/AlGaAs distributed Bragg reflector. A record value of over 2.6 W of output power in a spectral range around 1.57 microm was demonstrated, revealing the essential advantage of the wafer fusing technique over monolithically-grown all-InP-based structures. The presented approach allows for integration of lattice-mismatched compounds, quantum-well and quantum-dot based media. This would provide convenient means for extending the wavelength range of semiconductor disk lasers. PMID:19104620

  8. Performance assessment of a new laser system for efficient spin exchange optical pumping in a spin maser measurement of 129Xe EDM

    NASA Astrophysics Data System (ADS)

    Funayama, C.; Furukawa, T.; Sato, T.; Ichikawa, Y.; Ohtomo, Y.; Sakamoto, Y.; Kojima, S.; Suzuki, T.; Hirao, C.; Chikamori, M.; Hikota, E.; Tsuchiya, M.; Yoshimi, A.; Bidinosti, C. P.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

    2015-11-01

    We demonstrate spin-exchange optical pumping of 129Xe atoms with our newly made laser system. The new laser system was prepared to provide higher laser power required for the stable operation of spin maser oscillations in the 129Xe EDM experiment. We studied the optimum cell temperature and pumping laser power to improve the degree of 129Xe spin polarization. The best performance was achieved at the cell temperature of 100 ∘C with the presently available laser power of 1 W. The results show that a more intense laser is required for further improvement of the spin polarization at higher cell temperatures in our experiment.

  9. 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.

  10. Use of a pulse-periodic optically pumped CF4 laser for photofragmentation of UF6 molecules

    NASA Astrophysics Data System (ADS)

    Kolesnikov, Yurij A.; Kotov, A. A.; Novikov, Victor P.

    1998-05-01

    Investigations of fragmentation of uranium hexafluoride molecules in radiation field of the optically pumped CF4 laser are carried out. The optical pumping was made by the pulse-periodic TEA CO2 laser. The optical cell of the CF4 laser was cooled by nitrogen vapor with automatic stabilization of the temperature. The maximum radiation energy carried by a single CF4 laser pulse is 250 mJ and the average power at a pulse repetition frequency of 50 Hz is up to 6 W. It was found that besides the direct fragmentation of UF6 molecules, the bimolecular V-V exchange realizes most probably at collision of highly excited molecules, consequently the vibronic energy of one of the molecules can exceed the dissociation threshold. Increase by an order of the UF6 molecules photofragmentation efficiency at presence of hydrogen can be explained by high chemical activation because of reverse electron relaxation of highly vibronic excited UF6 molecules. There is also ascertained that polymerization of UF5 radicals appears to be the most high-speed of al secondary reactions. In the main part the polymers ar found on the cell surface having number of the radicals in range from 2 to approximately 10.

  11. 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.

  12. Diode-side-pumped Nd:YLiF4 laser emitting at 1053 nm with 53.6% optical efficiency and diffraction-limited beam quality

    NASA Astrophysics Data System (ADS)

    Wetter, Niklaus U.; Deana, Alessandro M.

    2013-03-01

    We present a Nd:YLiF4 diode-side-pumped resonator architecture based on a gain-guided, mode-selective technique that employs a double pass of the fundamental laser mode through the crystal. The folded cavity is very compact, robust and cost efficient. With this design we demonstrate 19 W of quasi-cw, stable diffraction-limited laser emission at 1053 nm when pumping at 792 nm with 35.4 W. The slope efficiency of the laser is 65.3% and the optical-to-optical efficiency is 53.6%, which is, to the best of our knowledge, the highest efficiency reported for Nd:YLiF4 lasers pumped into the 4F5/2 band, including longitudinal pumping schemes and lasers emitting at the higher gain line of 1047 nm.

  13. Supercontinuum generation in a suspended core birefringent tellurite microstructured optical fiber pumped in telecommunication band by a picosecond laser

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Tong, Hoang Tuan; Kawamura, Harutaka; Suzuki, Takenobu; Ohishi, Yasutake

    2016-02-01

    Based on a suspended core birefringent tellurite microstructured optical fiber (BTMOF), the supercontinuum (SC) spectra are generated by pumping near the zero dispersion wavelengths (ZDWs) in the telecommunication band with a tunable picosecond fiber laser. The ZDWs of the suspended core BTMOF are calculated to be 1560 nm and 1532 nm for the X-axis and Y-axis, respectively. When the pump is polarized along the X-axis, the SC broadening is governed by the nonlinear effects of four-wave mixing (FWM), cross-phase modulation (XPM) and stimulated Raman scattering (SRS). When the pump is polarized along the Y-axis, the SC generation is governed by the nonlinear effects of SRS.

  14. Analytical model of thermal effect and optical path difference in end-pumped Yb:YAG thin disk laser.

    PubMed

    Zhu, Guangzhi; Zhu, Xiao; Wang, Mu; Feng, Yufan; Zhu, Changhong

    2014-10-10

    An analytical model of the thermal effect and optical path difference (OPD) of a thin disk laser is developed with the combination of the analytical method and commercial finite element analysis software. The distributions of temperature, stress, strain, and OPD caused by temperature gradient, axial thermal strain (bulging), thermal strain-induced birefringence, and deformation are obtained. Based on the analytical model, the production mechanisms, features, and influence of OPD in an end-pumped thin disk laser are discussed, which make the causes of spherical and aspherical parts of the OPD more obvious. Furthermore, the OPD including the spherical and aspherical parts of the thin disk crystal is discussed for various pumping intensities. PMID:25322379

  15. Gigashot Optical Laser Demonstrator

    SciTech Connect

    Deri, R. J.

    2015-10-13

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

  16. Efficient OPSL-pumped mode-locked Yb:Lu2O3 laser with 67% optical-to-optical efficiency

    NASA Astrophysics Data System (ADS)

    Heuer, Alexander M.; Saraceno, Clara J.; Beil, Kolja; Huber, Günter; Kränkel, Christian

    2016-01-01

    We present a mode-locked Yb:Lu2O3 laser with up to 67% of optical-to-optical efficiency. By utilizing a high brightness optically pumped semiconductor laser (OPSL) as a pump source and using a semiconductor saturable absorber mirror (SESAM) we obtained self-starting mode locking. A pulse duration of 571 fs at 4.73 W of average output power with an optical-to-optical efficiency of 67% was achieved. In a slightly different cavity configuration the pulse duration was reduced to 313 fs at 2.16 W of average output power. In both cases the pulse duration was longer than the Fourier limit and the spectrum supports significantly shorter pulse durations. The laser wavelength is centered at 1034 nm and the repetition rate is 100.76 MHz in both cases. In continuous wave fundamental mode operation the optical-to-optical efficiency was as high as 78% with output powers exceeding 5 W.

  17. Efficient OPSL-pumped mode-locked Yb:Lu2O3 laser with 67% optical-to-optical efficiency.

    PubMed

    Heuer, Alexander M; Saraceno, Clara J; Beil, Kolja; Huber, Günter; Kränkel, Christian

    2016-01-01

    We present a mode-locked Yb:Lu2O3 laser with up to 67% of optical-to-optical efficiency. By utilizing a high brightness optically pumped semiconductor laser (OPSL) as a pump source and using a semiconductor saturable absorber mirror (SESAM) we obtained self-starting mode locking. A pulse duration of 571 fs at 4.73 W of average output power with an optical-to-optical efficiency of 67% was achieved. In a slightly different cavity configuration the pulse duration was reduced to 313 fs at 2.16 W of average output power. In both cases the pulse duration was longer than the Fourier limit and the spectrum supports significantly shorter pulse durations. The laser wavelength is centered at 1034 nm and the repetition rate is 100.76 MHz in both cases. In continuous wave fundamental mode operation the optical-to-optical efficiency was as high as 78% with output powers exceeding 5 W. PMID:26739546

  18. Efficient OPSL-pumped mode-locked Yb:Lu2O3 laser with 67% optical-to-optical efficiency

    PubMed Central

    Heuer, Alexander M.; Saraceno, Clara J.; Beil, Kolja; Huber, Günter; Kränkel, Christian

    2016-01-01

    We present a mode-locked Yb:Lu2O3 laser with up to 67% of optical-to-optical efficiency. By utilizing a high brightness optically pumped semiconductor laser (OPSL) as a pump source and using a semiconductor saturable absorber mirror (SESAM) we obtained self-starting mode locking. A pulse duration of 571 fs at 4.73 W of average output power with an optical-to-optical efficiency of 67% was achieved. In a slightly different cavity configuration the pulse duration was reduced to 313 fs at 2.16 W of average output power. In both cases the pulse duration was longer than the Fourier limit and the spectrum supports significantly shorter pulse durations. The laser wavelength is centered at 1034 nm and the repetition rate is 100.76 MHz in both cases. In continuous wave fundamental mode operation the optical-to-optical efficiency was as high as 78% with output powers exceeding 5 W. PMID:26739546

  19. 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.

  20. 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.

  1. Optical and infrared lasers

    NASA Technical Reports Server (NTRS)

    Javan, A.

    1978-01-01

    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.

  2. Saturated amplification of a collisionally pumped optical-field-ionization soft X-ray laser at 41.8 nm.

    PubMed

    Sebban, S; Haroutunian, R; Balcou, P; Grillon, G; Rousse, A; Kazamias, S; Marin, T; Rousseau, J P; Notebaert, L; Pittman, M; Chambaret, J P; Antonetti, A; Hulin, D; Ros, D; Klisnick, A; Carillon, A; Jaeglé, P; Jamelot, G; Wyart, J F

    2001-04-01

    We report the first saturated amplification of an optical-field-ionization soft x-ray laser. The amplifying medium is generated by focusing a circularly polarized 330-mJ, 35-fs, 10-Hz Ti:sapphire laser system in a few-mm cell filled with xenon. A gain of 67 cm(-1) on the 4d(9)5p-4d(9)5d transition at 41.8 nm in Pd-like xenon and a gain-length product of 15 have been inferred at saturation. This source delivers about 5 x 10(9) photons per pulse. The influence of the pumping energy and the laser polarization on the lasing output are also presented. PMID:11290093

  3. Holmium laser pumped with a neodymium laser

    SciTech Connect

    Bowman, S.R.; Rabinovich, W.S.

    1991-07-30

    This patent describes a solid-state laser device. It comprises a holmium laser having a first host material doped with an amount of holmium ions sufficient to produce an output laser emission at about 3 {mu}m when the holmium ions in the holmium laser are pumped by a pump beam at a wavelength of about 1.1 {mu}m; and neodymium laser pump source means for supplying a pump beam to pump the holmium ions in the holmium laser at a wavelength of about 1.1 {mu}m.

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

    PubMed

    Klenner, Alexander; Keller, Ursula

    2015-04-01

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

  5. Coupling quantum dots to optical fiber: Low pump threshold laser in the red with a near top hat beam profile

    NASA Astrophysics Data System (ADS)

    Cheng, H.; Mironov, A. E.; Ni, J. H.; Yang, H. J.; Chen, W. W.; Dai, Z.; Dragic, P. D.; Dong, J.; Park, S.-J.; Eden, J. G.

    2015-02-01

    Direct coupling of the optical field in a ˜244 nm thick, CdSe/ZnS quantum dot film to an optical fiber has yielded lasing in the red (λ ˜ 644 nm) with a threshold pump energy density < 2.6 mJ cm-2. Comprising 28-31 layers of ˜8 nm diameter quantum dots deposited onto the exterior surface of a 125 μm diameter coreless silica fiber, this free-running oscillator produces 134 nJ in 3.6 ns FWHM pulses which correspond to 37 W of peak power from an estimated gain volume of ˜4.5 × 10-7 cm3. Lasing was confirmed by narrowing of the output optical radiation in both the spectral and temporal domains, and the laser beam intensity profile approximates a top hat.

  6. Temporal model of an optically pumped co-doped solid state laser

    NASA Technical Reports Server (NTRS)

    Wangler, T. G.; Swetits, J. J.; Buoncristiani, A. M.

    1993-01-01

    Currently, research is being conducted on the optical properties of materials associated with the development of solid state lasers in the two micron region. In support of this effort, a mathematical model describing the energy transfer in a holmium laser sensitized with thulium is developed. In this paper, we establish some qualitative properties of the solution of the model, such as non-negativity, boundedness, and integrability. A local stability analysis is then performed from which conditions for asymptotic stability are attained. Finally, we report on our numerical analysis of the system and how it compares with experimental results.

  7. Solar pumped laser technology options for space power transmission

    NASA Technical Reports Server (NTRS)

    Conway, E. J.

    1986-01-01

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

  8. 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.

  9. 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.

  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. PMID:25302156

  11. Photoexcitation of lasers and chemical reactions for NASA missions: A theoretical study. [optical pumping in high pressure gas

    NASA Technical Reports Server (NTRS)

    Javan, A.; Guerra, M.

    1981-01-01

    The possibility of obtaining CW laser oscillation by optical pumping in the infrared at an elevated gas pressure is reviewed. A specific example utilizing a mixture of CO and NO gases is included. The gas pressures considered are in excess of several atmospheres. Laser frequency tuning over a broad region becomes possible at such elevated gas pressures due to collisional broadening of the amplifying transitions. The prior-rate and surprisal analysis are applied to obtain detailed VV and VT rates for CO and NO molecules and the transfer rates in a CO-NO gas mixture. The analysis is capable of giving temperature dependence of the rate constants. Computer estimates of the rates are presented for vibrational levels up to v = 50. The results show that in the high-lying vibrational states the VV transfer rates with Delta nu = 2 become appreciable.

  12. The GTR-KTP intracavity optical parametric oscillator driven by a diode-end-pumped acousto-optical Q-switched Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Huang, H. T.; Zhang, B. T.; He, J. L.

    2013-03-01

    An efficient eye-safe gray-trace resistance-KTP (GTR-KTP) intracavity optical parametric oscillator (IOPO) excited by a diode-end-pumped Q-switched Nd:YAG laser was demonstrated. Under a laser diode power of 11.4 W, a maximum average output power of 1.2 W at 1572 nm was obtained at a repetition rate of 15 kHz, corresponding to a diode-to-signal conversion efficiency of 10.5%. As for the common KTP IOPO under the same pump conditions and cavity design, a lower average output power of 0.96 W was obtained. Consequently, the corresponding GTR-KTP OPO conversion efficiency was increased by 25% compared with that obtained in common KTP IOPO.

  13. X-ray studies and time-resolved photoluminescence on optically pumped antimonide-based midinfrared type-II lasers.

    PubMed

    Schwender, Carsten; Drumm, Jan Oliver; Hoffmann, Goetz; Vogelgesang, Birgit; Fouckhardt, Henning

    2004-12-01

    We report on high-resolution X-ray diffraction and time-resolved photoluminescence (TR-PL) studies of antimonide-based midinfrared (MIR) type-II laser samples. A structural characterization taking into account asymmetrical strain, layer tilting, and relaxation enables an accurate determination of the average lattice constant of the active region and the composition of the cladding layers. By designing the antimonide-to-arsenide interfaces, we achieve exact lattice matching of the active region to the substrate. Non-radiative recombination processes are investigated with time-resolved photoluminescence. The samples are also characterized under optically pumped laser operation. By an examination of the time-integrated and time-resolved amplified spontaneous emission (TR-ASE), we investigate the modal gain and gain dynamics. The variable stripe length method is combined with the TR-PL approach. Compared to the time-integrated gain spectra the spectral dependence of the maximum and minimum time-resolved gain shows a broad plateau. The full width half maximum (FWHM) of the TR-ASE pulse is 5.5 +/- 0.5 ps. Thus, short pulses in this range should be achievable upon laser operation. The active regions of the laser structures investigated here are promising subunits of type-II quantum cascade lasers. PMID:15561624

  14. Diode-pumped optical parametric oscillator

    SciTech Connect

    Geiger, A.R.; Hemmati, H.; Farr, W.H.

    1996-02-01

    Diode-pumped optical parametric oscillation has been demonstrated for the first time to our knowledge in a single Nd:MgO:LiNbO{sub 3} nonlinear crystal. The crystal is pumped by a semiconductor diode laser array at 812 nm. The Nd{sup 3+} ions absorb the 812-nm radiation to generate 1084-nm laser oscillation. On internal {ital Q} switching the 1084-nm radiation pumps the LiNbO{sub 3} host crystal that is angle cut at 46.5{degree} and generates optical parametric oscillation. The oscillation threshold that is due to the 1084-nm laser pump with a pulse length of 80 ns in a 1-mm-diameter beam was measured to be {approx_equal}1 mJ and produced 0.5-mJ output at 3400-nm signal wavelength. {copyright} {ital 1996 Optical Society of America.}

  15. 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.

  16. Few-cycle, broadband, mid-infrared optical parametric oscillator pumped by a 20-fs Ti:sapphire laser

    PubMed Central

    Chaitanya Kumar, Suddapalli; Esteban-Martin, Adolfo; Ideguchi, Takuro; Yan, Ming; Holzner, Simon; Hänsch, Theodor W; Picqué, Nathalie; Ebrahim-Zadeh, Majid

    2014-01-01

    A few-cycle, broadband, singly-resonant optical parametric oscillator (OPO) for the mid-infrared based on MgO-doped periodically-poled LiNbO3 (MgO:PPLN), synchronously pumped by a 20-fs Ti:sapphire laser is reported. By using crystal interaction lengths as short as 250 µm, and careful dispersion management of input pump pulses and the OPO resonator, near-transform-limited, few-cycle idler pulses tunable across the mid-infrared have been generated, with as few as 3.7 optical cycles at 2682 nm. The OPO can be continuously tuned over 2179-3732 nm (4589-2680 cm-1) by cavity delay tuning, providing up to 33 mW of output power at 3723 nm. The idler spectra exhibit stable broadband profiles with bandwidths spanning over 422 nm (FWHM) recorded at 3732 nm. The effect of crystal length on spectral bandwidth and pulse duration is investigated at a fixed wavelength, confirming near-transform-limited idler pulses for all grating interaction lengths. By locking the repetition frequency of the pump laser to a radio-frequency reference, and without active stabilization of the OPO cavity length, an idler power stability better than 1.6% rms over >2.75 hours is obtained when operating at maximum output power, in excellent spatial beam quality with TEM00 mode profile. Photograph shows a multigrating MgO:PPLN crystal used as a nonlinear gain medium in the few-cycle femtosecond mid-IR OPO. The visible light is the result of non-phase-matched sum-frequency mixing between the interacting beams. PMID:25793016

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

    DOEpatents

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

    2010-09-28

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

  18. Plasma channel optical pumping device and method

    DOEpatents

    Judd, O'Dean P.

    1983-06-28

    A device and method for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an electrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature blackbody radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device.

  19. Plasma channel optical pumping device and method

    DOEpatents

    Judd, O.P.

    1983-06-28

    A device and method are disclosed for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an electrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature blackbody radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device. 5 figs.

  20. One-Watt level mid-IR output, singly resonant, continuous-wave optical parametric oscillator pumped by a monolithic diode laser.

    PubMed

    Nieuwenhuis, Ab F; Lee, Chris J; Sumpf, Bernd; van der Slot, Peter J M; Erbert, Götz; Boller, Klaus-J

    2010-05-24

    We report more than 1.1 Watt of idler power at 3373 nm in a singly resonant optical parametric oscillator (SRO), directly pumped by a single-frequency monolithic tapered diode laser. The SRO is based on a periodically poled MgO:LiNbO3 crystal in a four mirror cavity and is excited by 8.05 W of 1062 nm radiation. The SRO pump power at threshold is 4 W. The internal slope-efficiency and conversion efficiency reach 89% and 44% respectively. The signal and idler waves are temperature tuned in the range of 1541 to 1600 nm and 3154 to 3415 nm respectively. To the best of our knowledge, this is the highest output obtained for a diode pumped optical parametric oscillator (OPO), and the first time a SRO is directly pumped by a monolithic tapered diode laser. PMID:20588971

  1. Chromium doped ZnSe and ZnS gain media for optically and electrically pumped mid-IR lasers

    NASA Astrophysics Data System (ADS)

    Kim, C.; Peppers, J. M.; Martyshkin, D. V.; Fedorov, V. V.; Mirov, S. B.

    2009-02-01

    We report methods of fabrication and laser-spectroscopic characterization of mid-IR gain media based on micron size Cr2+:ZnSe/ZnS powders, as well as Cr2+:ZnSe/ZnS doped fluorocarbon polymer films, and perfluorocarbon liquids. All samples demonstrated strong mid-IR luminescence over 2000-3000nm spectral range under optical 1700nm excitation. The random lasing of the doped liquids and polymer films was realized with pump energy density of 100 and 15mJ/cm2, respectively. Previously we have demonstrated mid-IR electroluminescence of Cr:ZnSe with n-conductivity provided by thermal diffusion of Al and Zn. However, the formation of conductivity was accompanied by compensation of the Cr2+ optical centers and relatively weak chromium electroluminescence. In this paper we report study of the Cr2+ compensation in the crystals co-doped with donor and acceptor impurities. Optical and electrical characterization of Cr:ZnSe crystals with Ag, Cu, Al, In, and Zn co-dopants were studied to optimize mid-IR electroluminescens of the Cr2+ ions. The best results were obtained with p-conductive Ag:Cr:ZnSe samples featuring a low 600 Ωcm resistivity. First mid-IR electroluminescence in presumable p-type Ag:Cr:ZnSe was demonstrated, which could prove valuable for developing laser diodes that function in this spectral region.

  2. Tunable 10- to 11-μm CdSe optical parametric oscillator pumped by a 2.1-μm Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Yuan, J. H.; Duan, X. M.; Yao, B. Q.; Cui, Z.; Li, Y. Y.; Dai, T. Y.; Shen, Y. J.; Ju, Y. L.

    2016-07-01

    We demonstrated a CdSe optical parametric oscillator (OPO) pumped by a 2090.7-nm Ho:YAG laser at a pulse repetition frequency of 500 Hz. Up to 140 mW output which corresponds to a pulse energy of 280 μJ was obtained at the idler wavelength of 10.28 μm with a pump power of 7 W. The idler pulse width was 19 ns when pumped by a 32 ns pulse. The idler wavelength can be tuned from 10.07 to 11.1 μm. With 6.3 W pump, the output power at 11.1 μm reached 46 mW (92 μJ pulse energy). To the best of our knowledge, 11.1 μm was the longest wavelength obtained with a 2.1-μm laser pumped CdSe OPO.

  3. Optical parametric oscillators synchronously pumped by fundamental and second harmonic radiation of femtosecond Yb:KGW laser

    NASA Astrophysics Data System (ADS)

    StankevičiÅ«tÄ--, K.; PipinytÄ--, I.; Vengelis, J.; MarcinkevičiÅ«tÄ--, A.; Å uminas, R.; Grigonis, R.; Eckardt, R. C.; Sirutkaitis, V.

    2013-09-01

    We present experimental data obtained during investigation of synchronously pumped optical parametric oscillators (SPOPO's) pumped by fundamental (1030 nm) and second harmonic (515 nm) radiation of mode-locked Yb:KGW laser, providing 105 fs pulses at 76 MHz repetition rate with an average power of 4 W. Different nonlinear crystals such as beta barium borate (BBO), and periodically poled lithium niobate (PPLN) and MgO doped PPLN (MgO:PPLN) were tested to estimate wavelength tuning capabilities and SPOPO's efficiency. Rotation of BBO nonlinear crystal and SPOPO's cavity length variation and, in the case of SPOPO based on PPLN, change of grating period and cavity length allowed signal wavelength tuning in 630 - 1030 nm and 1350 - 1700 nm spectral ranges, respectively. Parametric light conversion from pump power to signal power efficiency was as high as 25 %. Including the idler pulses the tuning ranges were from 630 to 2400 nm and from 1350 to 4000 nm in case of BBO and PPLN crystals, respectively. SPOPO based on BBO wsithout intracavity group velocity dispersion (GVD) compensation generates longer than transform limited pulses, so SPOPO based on BBO with dispersive prisms were investigated.

  4. High-power, fiber-laser-pumped, picosecond optical parametric oscillator based on MgO:sPPLT.

    PubMed

    Kumar, S Chaitanya; Ebrahim-Zadeh, M

    2011-12-19

    We report a stable, high-power, mid-infrared synchronously-pumped optical parametric oscillator (SPOPO) based on MgO:sPPLT, pumped by a 1064 nm, picosecond Yb-fiber laser operating at a repetition rate of 81.1 MHz. The singly resonant SPOPO is tunable over 1531-1642 nm (111 nm) in the near-infrared signal and 3022-3488 nm (466 nm) in the mid-infrared idler, providing a total tuning range of 577 nm. Careful optimization of output coupling results in a signal output power as high as 4.3 W at 1593 nm and a mid-infrared idler power of 2 W at 3204 nm for 13.4 W of pump power at a total extraction efficiency of 47%. The SPOPO can be operated near room temperature, down to 30 °C, and exhibits passive peak-to-peak power stability better than 8.6% at 1568 nm (signal) and 8.2% at 3310 nm (idler) over 13 hours at full power. The output signal pulses have duration of 17.5 ps, with a FWHM spectral bandwidth of 1.4 nm centered at 1568 nm. PMID:22274250

  5. 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.

  6. Optical afterburner for an x-ray free electron laser as a tool for pump-probe experiments

    NASA Astrophysics Data System (ADS)

    Saldin, E. L.; Schneidmiller, E. A.; Yurkov, M. V.

    2010-03-01

    We propose a new scheme for two-color operation of an x-ray self-amplified spontaneous emission free electron laser (SASE FEL). The scheme is based on an intrinsic feature of such a device: chaotic modulations of electron beam energy and energy spread on the scale of FEL coherence length are converted into large density modulations on the same scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful radiation is then generated with the help of a dedicated radiator (like an undulator that selects a narrow spectral line), or one can simply use, for instance, broadband edge radiation. A typical radiation wavelength can be as short as a FEL coherence length, and can be redshifted by increasing the dispersion section strength. In practice it means the wavelength ranges from vacuum ultraviolet to infrared. The long-wavelength radiation pulse is naturally synchronized with the x-ray pulse and can be either directly used in pump-probe experiments or cross correlated with a high-power pulse from a conventional laser system. In this way experimenters overcome jitter problems and can perform pump-probe experiments with femtosecond resolution. Additional possibilities like on-line monitoring of x-ray pulse duration (making “optical replica” of an x-ray pulse) are also discussed in the paper. The proposed scheme is very simple, cheap, and robust, and therefore can be easily realized in facilities like FLASH, European XFEL, LCLS, and SCSS.

  7. Development of a laser optically pumped polarized target for use in heavy-ion physics. [/sup 151/ /sup 153/Eu

    SciTech Connect

    Shivakumar, B.; Beene, J.R.; Bemis, C.E. Jr.; Erb, K.A.; Ford, J.L.C. Jr.; Shapira, D.

    1982-01-01

    Important micro- and macroscopic details of heavy-ion reactions may be explicitly determined when nuclear spin aligned (polarized) targets are used. For deformed nuclei, the orientation of the symmetry axis of the nuclear density distribution is determined by the nuclear spin orientation. Polarized targets would thus allow experiments to be performed as a function of the orientation of the symmetry axis of the nuclear density distribution. A polarized target of /sup 151/ /sup 153/Eu is being developed at Oak Ridge and is based on laser depopulation optical pumping. A spatially defined target is provided by a supersonic gas jet and consists of Eu atoms seeded into an inert carrier gas. Detailed time-dependent optical-pumping calculations predict approx. = 90% nuclear spin polarization in a Eu target with an expected thickness in excess of 10/sup 15/ atoms/cm/sup 2/. We present some of the effects that will be observable in heavy-ion reactions when deformed polarized targets are used.

  8. Lasing on the electronic B--X transition of the I/sub 2/ molecule optically pumped by a copper-vapor laser

    SciTech Connect

    Kaslin, V.M.; Petrash, G.G.; Yakushev, O.F.

    1980-04-01

    It is proposed to use pulsed metal-vapor lasers for optical pumping of gas lasers based on electronic transitions of molecules. This uncovers prospects for the development of effective lasers with high average and peak power, which are tunable in the visible and in the infrared. The first step in this direction are experiments on optical pumping of molecular iodine by a copper-vapor laser (lambda=5106 and 5782 A). Results of spectroscopic investigations are reported. It was found that the pumping is by five absorption lines of the X/sup 1/..sigma../sub g//sup +/-B/sup 3/Pi/sub 0//sup +//sub u/ system of the I/sub 2/ molecule, three of which give rise to lasing. The principal pumping was by the 5782 A line. Lasing was obtained on 14 vibrational transitions of the B/sup 3/Pi/sub 0//sup +//sub u/X/sup 1/..sigma../sub g//sup +/ system in the region 1.016--1.342 ..mu..m region. The average generation power in the multifrequency regime was 7 mW at an optical-energy conversion efficiency 4%. It was observed that a noticeable competition takes place between the pump channels of the 5106 and 5782 A lines, and leads to a decrease in the total lasing power. Prospects are discussed of using gas lasers on electronic transitions of molecules optically pumped by metal-vapor vapors, particularly for the development of frequency-tunable optical systems with intensity amplifiers.

  9. Pulsed optically pumped frequency standard

    SciTech Connect

    Godone, Aldo; Micalizio, Salvatore; Levi, Filippo

    2004-08-01

    We reconsider the idea of a pulsed optically pumped frequency standard conceived in the early 1960s to eliminate the light-shift effect. The development of semiconductor lasers and of pulsed electronic techniques for atomic fountains and new theoretical findings allow an implementation of this idea which may lead to a frequency standard whose frequency stability is limited only by the thermal noise in the short term and by the temperature drift in the long term. We shall also show both theoretically and experimentally the possibility of doubling the atomic quality factor with respect to the classical Ramsey technique approach.

  10. 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).

  11. Picosecond DPSS laser technology for OPCPA pumping

    NASA Astrophysics Data System (ADS)

    Vaupel, Andreas; Bodnar, Nathan; Webb, Benjamin; Shah, Lawrence; Richardson, Martin

    2014-02-01

    We present the design and challenges of a diode-pumped solid-state (DPSS) system to amplify picosecond pulses to high pulse energies and high average powers. We discuss our implemented solutions to mitigate thermal effects and present the obtained performance of the picosecond pulse amplification at the multi-10-MW level. Our here presented picosecond DPSS laser is well suited for pumping an optical parametric chirped-pulse amplification (OPCPA) system. Several laser technologies have been employed to pump OPCPA systems and we show how our DPSS system compares in performance to the other approaches.

  12. Theoretical simulations of protective thin film Fabry-Pérot filters for integrated optical elements of diode pumped alkali lasers (DPAL)

    SciTech Connect

    Quarrie, L. E-mail: lindsay.o.quarrie@gmail.com

    2014-09-15

    The lifetime of Diode-Pumped Alkali Lasers (DPALs) is limited by damage initiated by reaction of the glass envelope of its gain medium with rubidium vapor. Rubidium is absorbed into the glass and the rubidium cations diffuse through the glass structure, breaking bridging Si-O bonds. A damage-resistant thin film was developed enhancing high-optical transmission at natural rubidium resonance input and output laser beam wavelengths of 780 nm and 795 nm, while protecting the optical windows of the gain cell in a DPAL. The methodology developed here can be readily modified for simulation of expected transmission performance at input pump and output laser wavelengths using different combination of thin film materials in a DPAL. High coupling efficiency of the light through the gas cell was accomplished by matching the air-glass and glass-gas interfaces at the appropriate wavelengths using a dielectric stack of high and low index of refraction materials selected to work at the laser energies and protected from the alkali metal vapor in the gain cell. Thin films as oxides of aluminum, zirconium, tantalum, and silicon were selected allowing the creation of Fabry-Perot optical filters on the optical windows achieving close to 100% laser transmission in a solid optic combination of window and highly reflective mirror. This approach allows for the development of a new whole solid optic laser.

  13. Laser Paint Interactions Studied by Optical Emission Spectroscopy and Pump and Probe Analysis of the Ablation Plume

    NASA Astrophysics Data System (ADS)

    Rebollar, E.; Oujja, M.; Martín, M.; Castillejo, M.

    The ablation plumes resulting from the laser irradiation of pigments in the form of pellets and as tempera paints were studied by optical spectroscopic methods including optical emission spectroscopy (OES) and laser induced fluorescence (LIF), using a probe laser, delayed with respect to the ablation laser. The differences observed between emissions from pellets and from tempera paints of a given pigment, and between organic and inorganic pigments, serve to discuss the mechanisms operating in the laser irradiation of the paint systems.

  14. 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.

  15. Compact high power mid-infrared optical parametric oscillator pumped by a gain-switched fiber laser with "figure-of-h" pulse shape.

    PubMed

    Jiang, Peipei; Chen, Tao; Wu, Bo; Yang, Dingzhong; Hu, Chengzhi; Wu, Pinghui; Shen, Yonghang

    2015-02-01

    We demonstrate a compact high power mid-infrared (MIR) optical parametric oscillator (OPO) pumped by a gain-switched linearly polarized, pulsed fiber laser. The gain-switched fiber laser was constructed with a piece of Yb doped polarization maintaining (PM) fiber, a pair of fiber Bragg gratings written into the matched passive PM fiber and 6 pigtailed pump laser diodes working at 915 nm with 30 W output peak power each. By modulating the pulse width of the pump laser diode, simple pedestal-free pulse shape or pedestal-free trailing pulse shape ("figure-of-h" as we call it) could be achieved from the gain-switched fiber laser. The laser was employed as the pump of a two-channel, periodically poled magnesium oxide lithium niobate-based OPO system. High power MIR emission was generated with average output power of 5.15 W at 3.8 μm channel and 8.54 W at 3.3 μm channel under the highest pump power of 45 W. The corresponding pump-to-idler conversion efficiency was computed to be 11.7% and 19.1%, respectively. Experimental results verify a significant improvement to signal-to-idler conversion efficiency by using "figure-of-h" pulses over simple pedestal-free pulses. Compared to the master oscillator power amplifier (MOPA) fiber laser counterpart, the presented gain switched fiber laser is more attractive in OPO pumping due to its compactness and simplicity which are beneficial to construction of OPO systems for practical MIR applications. PMID:25836126

  16. Systematic Effects in Laser-Induced Fluorescence Measurments of Ion Density and Temperature Caused by Optical Pumping

    NASA Astrophysics Data System (ADS)

    Langin, Thomas; Strickler, Trevor; McQuillen, Patrick; Killian, Thomas

    2014-10-01

    Ultracold neutral plasmas of strontium are generated by photoionizing laser-cooled atoms. The plasma evolution is probed by laser induced fluorescence (LIF) via the 5s2S1/2-5p2P1/2 ion transition. Spectra are obtained by recording LIF intensity at varying laser detunings. The ion temperature, T, is then measured by fitting a Voigt profile to obtain the Doppler width. However, for linearly (circularly) polarized light, 5p2P1/2 ions have a 7% (33%) chance of decaying to the dark metastable 5d 2D3/2 state (dark opposite spin state). Near resonance, where ions are more likely to scatter multiple photons during the LIF process, the observed signal will be depressed due to optical pumping. This causes an artificial broadening in the spectra and thus artificially high T measurements. Moreover, the loss of ions throughout the excitation process, if not corrected for, will result in artificially low density measurements. We have developed, and experimentally verified, a method for simulating the LIF process in order to determine the LIF-probe durations and intensities for which these effects becomes significant. This work was supported by the National Science Foundation and the Department of Energy (PHY-0714603), the Air Force Office of Scientific Research (FA9550-12-1-0267), the Department of Defense (NDSEG Fellowship), and Shell

  17. Optically pumped metal vapor lasers. Final technical report, 15 Apr 1978-15 Jul 1980

    SciTech Connect

    Mandl, A.; Hyman, H.

    1980-09-01

    The properties of optically-excited Hg/NH/sub 3/ and Hg/ND/sub 3/ mixtures have been studied as a function of mercury pressure in the range 1 to 40 torr. At low mercury pressures, less than or equal to 1 torr, the well-known uv emission band due to HgNH/sub 3/* is dominant; this regime has been investigated extensively over the past ten years. However, at higher pressures the uv band disappears and is replaced by a strong green emission band, centered near 500 nm. From a detailed study of the spectral and temporal characteristics of the green band, it is concluded that it arises from the formation of the Hg/sub 2/NH/sub 3/* (or Hg/sub 2/ND/sub 3/*) excited molecular complex. The lifetime of this exciplex has been measured and is found to be 3.8 ..mu..sec (+- 25%). Because of interest in the system as a potential energy storage laser medium, optical transmission measurements have been carried out at selected wavelengths. Net absorption has been observed across the green band at high mercury density, as well as in the uv band in the low density regime.

  18. Possibilities of increasing the pumping efficiency of solid active medium laser generators by optimizing the pumping cavity profile

    NASA Astrophysics Data System (ADS)

    Dontu, O.; Ganatsios, S.; Alexandrescu, N.

    2008-03-01

    The paper presents some design elements concerning the optical pumping cavities of the laser generators with active solid medium, as well as the way of increasing their performance. We start from the fact that the laser cavity is a closed optical system, where the active laser medium and the pumping source are conjugated, in order to achieve a maximum concentration of the light flux of the pumping source towards the active medium. We discuss the simple elliptical section laser pumping cavities (with one pumping lamp) and triple elliptical (with three lamps), also presenting a series on calculus nomograms, very useful to those who design the laser generation optical pumping cavities.

  19. Laser-Induced Fluorescence Measurements of Translational Temperature and Relative Cycle Number by use of Optically Pumped Trace-Sodium Vapor

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.

    1999-01-01

    Sodium fluorescence induced by a narrow-bandwidth tunable laser has been used to measure temperature, pressure, axial velocity, and species concentrations in wind tunnels, rocket engine exhausts, and the upper atmosphere. Optical pumping of the ground states of the sodium, however, can radically alter the shape of the laser-induced fluorescence excitation spectrum, complicating such measurements. Here a straightforward extension of rate equations originally proposed to account for the features of the pumped spectrum is used to make temperature measurements from spectra taken in pumped vapor. Also determined from the spectrum is the relative fluorescence cycle number, which has application to measurement of diffusion rate and transverse flow velocity, The accuracy of both the temperature and the cycle-number measurements is comparable with that of temperature measurements made in the absence of pumping.

  20. Laser-Induced Fluorescence Measurements of Translational Temperature and Relative Cycle Number by use of Optically Pumped Trace-Sodium Vapor

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.

    1998-01-01

    Sodium fluorescence induced by a narrow bandwidth tunable laser has been used to measure temperature, pressure, axial velocity and species concentrations in wind tunnels, rocket engine exhausts and the upper atmosphere. Optical pumping of the ground states of the sodium, however, can radically alter the shape of the laser induced fluorescence excitation spectrum, complicating such measurements. Here a straightforward extension of rate equations originally proposed to account for the features of the pumped spectrum is to make temperature measurements from spectra taken in pumped vapor. Also determined from the spectrum is the relative fluorescence cycle number, which has application to measurement of diffusion rate and transverse flow velocity. The accuracy of both the temperature and cycle-number measurements is comparable with that of temperature measurements made in the absence of pumping.

  1. Laser-induced fluorescence measurements of translational temperature and relative cycle number by use of optically pumped trace-sodium vapor.

    PubMed

    Dobson, C C

    1999-06-20

    Sodium fluorescence induced by a narrow-bandwidth tunable laser has been used to measure temperature, pressure, axial velocity, and species concentrations in wind tunnels, rocket engine exhausts, and the upper atmosphere. Optical pumping of the ground states of the sodium, however, can radically alter the shape of the laser-induced fluorescence excitation spectrum, complicating such measurements. Here a straightforward extension of rate equations originally proposed to account for the features of the pumped spectrum is used to make temperature measurements from spectra taken in pumped vapor. Also determined from the spectrum is the relative fluorescence cycle number, which has application to measurement of diffusion rate and transverse flow velocity. The accuracy of both the temperature and the cycle-number measurements is comparable with that of temperature measurements made in the absence of pumping. PMID:18320000

  2. Coupling quantum dots to optical fiber: Low pump threshold laser in the red with a near top hat beam profile

    SciTech Connect

    Cheng, H.; Mironov, A. E.; Ni, J. H.; Yang, H. J.; Chen, W. W.; Dai, Z.; Park, S.-J.; Eden, J. G.; Dragic, P. D.; Dong, J.

    2015-02-23

    Direct coupling of the optical field in a ∼244 nm thick, CdSe/ZnS quantum dot film to an optical fiber has yielded lasing in the red (λ ∼ 644 nm) with a threshold pump energy density < 2.6 mJ cm{sup −2}. Comprising 28–31 layers of ∼8 nm diameter quantum dots deposited onto the exterior surface of a 125 μm diameter coreless silica fiber, this free-running oscillator produces 134 nJ in 3.6 ns FWHM pulses which correspond to 37 W of peak power from an estimated gain volume of ∼4.5 × 10{sup −7} cm{sup 3}. Lasing was confirmed by narrowing of the output optical radiation in both the spectral and temporal domains, and the laser beam intensity profile approximates a top hat.

  3. Solar-pumped laser on the Space Station

    SciTech Connect

    Arashi, H.; Oka, Y.; Ishigame, M.

    1985-01-01

    A solid state solar pumped laser system to be used on the Space Station is described. The system is based on an experimental version of a solar pumped Nd:YAG laser which has achieved a maximum power in excess of 18 W in multi-mode. The laser is powered by a paraboloid solar radiation concentrator. A solar pumped gas laser system is recommended for applications requiring a higher output power. Applications of a laser on board the Space Station include optical communication; laser propulsion; energy conversion; and high speed laser processing. Detailed schematic drawings of the solid state and gas laser designs are provided.

  4. Wavefront curvature of an opticaly pumped waveguide laser

    SciTech Connect

    Tacke, M.

    1983-05-01

    The influence of inhomogeneous gain on the wavefront shape is discussed for waveguide lasers. As an example, the curvature of the EH(11) mode of an optically pumped FIR laser is computed, its influence on the output beam is discussed.

  5. Fiber-laser-based, green-pumped, picosecond optical parametric oscillator using fan-out grating PPKTP.

    PubMed

    Chaitanya Kumar, S; Parsa, S; Ebrahim-Zadeh, M

    2016-01-01

    We report a stable, Yb-fiber-laser-based, green-pumped, picosecond optical parametric oscillator (OPO) for the near-infrared based on periodically poled potassium titanyl phosphate (PPKTP) nonlinear crystal, using fan-out grating design and operating near room temperature. The OPO is continuously tunable across 726-955 nm in the signal and 1201-1998 nm in the idler, resulting in a total signal plus idler wavelength coverage of 1026 nm by grating tuning at a fixed temperature. The device generates up to 580 mW of average power in the signal at 765 nm and 300 mW in the idler at 1338 nm, with an overall extraction efficiency of up to 52% and a pump depletion >76%. The extracted signal at 765 nm and idler at 1746 nm exhibit excellent passive power stability better than 0.5% and 0.8% rms, respectively, over 1 h with good beam quality in TEM00 mode profile. The output signal pulses have a Gaussian temporal duration of 13.2 ps, with a FWHM spectral bandwidth of 3.4 nm at 79.5 MHz repetition rate. Power scaling limitations of the OPO due to the material properties of PPKTP are studied. PMID:26696156

  6. Bidirectional pumped high power Raman fiber laser.

    PubMed

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

    2016-03-21

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

  7. Diode-pumped CW molecular lasers

    NASA Astrophysics Data System (ADS)

    Wellegehausen, B.; Luhs, W.

    2016-05-01

    First continuous laser oscillation on many lines in the range of 533-635 nm on different transitions of Na2 and Te2 molecules has been obtained, optically pumped with common cw blue emitting InGaN diode lasers operating around 445 and 460 nm. Spectral narrowing of the diode laser is achieved with a beamsplitter and grating setup, allowing use of more than 50 % of the diode power. Operation conditions and properties of the laser systems are presented, and perspectives for the realization of compact low cost molecular lasers are discussed.

  8. 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.

  9. 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.

  10. A non-critically phase matched KTA optical parametric oscillator intracavity pumped by an actively Q-switched Nd:GYSGG laser with dual signal wavelengths

    NASA Astrophysics Data System (ADS)

    Zhong, Kai; Guo, Shibei; Wang, Maorong; Mei, Jialin; Xu, Degang; Yao, Jianquan

    2015-06-01

    A non-critically phase matched eye-safe KTA optical parametric oscillator intracavity pumped by a dual-wavelength acousto-optically Q-switched Nd:GYSGG laser is demonstrated. Simultaneous dual signal wavelength at 1525.1 nm/1531.2 nm can be realized using only one laser crystal and one nonlinear crystal. When the absorbed diode pump power at 808 nm is 7.48 W, the maximum output power, single pulse energy and peak power are 296 mW, 2.96 μJ and 6.4 kW, respectively. As the signal wavelengths exactly locates at the absorption band of C2H2, such an Nd:GYSGG/KTA eye-safe laser has good application prospects in differential absorption lidar (DIAL) for C2H2 detection and difference frequency generation for terahertz waves at 0.77 THz.

  11. Doppler-free spectroscopy of mercury at 253.7 nm using a high-power, frequency-quadrupled, optically pumped external-cavity semiconductor laser.

    PubMed

    Paul, Justin; Kaneda, Yushi; Wang, Tsuei-Lian; Lytle, Christian; Moloney, Jerome V; Jones, R Jason

    2011-01-01

    We have developed a stable, high-power, single-frequency optically pumped external-cavity semiconductor laser system and generate up to 125 mW of power at 253.7 nm using successive frequency doubling stages. We demonstrate precision scanning and control of the laser frequency in the UV to be used for cooling and trapping of mercury atoms. With active frequency stabilization, a linewidth of <60 kHz is measured in the IR. Doppler-free spectroscopy and stabilization to the 6(1)S(0)-6(3)P(1) mercury transition at 253.7 nm is demonstrated. To our knowledge, this is the first demonstration of Doppler-free spectroscopy in the deep UV based on a frequency-quadrupled, high-power (>1 W) optically pumped semiconductor laser system. The results demonstrate the utility of these devices for precision spectroscopy at deep-UV wavelengths. PMID:21209687

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

    DOEpatents

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

    2014-07-22

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

  13. Development of a high intensity laser for efficient spin exchange optical pumping in a spin maser measurement of the 129Xe EDM

    NASA Astrophysics Data System (ADS)

    Funayama, Chikako; Furukawa, Takeshi; Sato, Tomoya; Ichikawa, Yuichi; Ohtomo, Yuichi; Sakamoto, Yu; Kojima, Shuichiro; Suzuki, Takahiro; Chikamori, Masatoshi; Hikota, Eri; Tsuchiya, Masato; Yoshimi, Akihiro; Bidinosti, Christopher; Ino, Takashi; Ueno, Hideki; Matsuo, Yukari; Fukuyama, Takeshi; Asahi, Koichiro

    2014-09-01

    We aim to search for an atomic electric dipole moment (EDM) in 129Xe beyond the present upper limit at the level of 10-28 e cm. The enhancement of the spin polarization through the efficient spin-exchange optical pumping process is important for stable maser operation. Previously, a distributed feedback (DFB) laser and a spatially separated tapered amplifier (TA) were used for the optical pumping. The characteristics of the TA-DFB laser, such as its narrow line width and high frequency stability, enable us to produce a large spin polarization. However, the power of the TA-DFB laser was not sufficient for stable operation of the 3He spin-maser comagnetometer. Recently, we have been preparing a new laser system containing an external cavity laser diode (ECLD) and a more intense TA for more efficient pumping. In the presentation, we discuss the Rb and noble gases polarizations achieved with our new ECLD compared to that with the DFB laser, and evaluate the advantages gained by employing the ECLD.

  14. 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.

  15. Properties of 4-dicyanomethylene-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran-doped Alq layers as optically pumped lasers

    NASA Astrophysics Data System (ADS)

    Jakabovič, J.; Lengyel, O.; Kováč, J.; Wong, T. C.; Lee, C. S.; Lee, S. T.

    2003-08-01

    The optical properties of tris-(8-hydroxyquinoline) aluminum (Alq) doped with 4-dicyanomethylene-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM) in solutions and in solid films were studied by measuring the steady-state excitation and spontaneous emission spectra. The emission peak in the solid films shifted from 628 to 659 nm as the doping concentration of DCM changed from 0.9% to 11%. The optically pumped waveguide lasers were fabricated by coevaporation of Alq films with 1.3 wt % DCM onto gallium arsenide (GaAs) substrates using silicon dioxide (SiO2) and magnesium fluoride (MgF2) as cladding layers. Both types of waveguide laser structures showed optical confinement and simulated emission at a threshold pumping energy near 1.4 μJ. The result suggests a thin MgF2 may be used as a confinement layer that has the advantage of preparation by low-temperature evaporation.

  16. Coherent combining of fiber-laser-pumped frequency converters using all fiber electro-optic modulator for active phase control

    NASA Astrophysics Data System (ADS)

    Bourdon, P.; Durécu, A.; Canat, G.; Le Gouët, J.; Goular, D.; Lombard, L.

    2015-03-01

    Coherent beam combining (CBC) by active phase control could be useful for power scaling fiber-laser-pumped optical frequency converters like OPOs. However, a phase modulator operating at the frequency-converted wavelength is needed, which is non standard component. Fortunately, nonlinear conversion processes rely on a phase-matching condition correlating, not only the wave vectors of the coupled waves, but also their phases. This paper demonstrates that, using this phase correlation for indirect control of the phase, coherent combining of optical frequency converters is feasible using standard all-fibered electro-optic modulators. For the sake of demonstration, this new technique is experimentally applied twice for continuous wave second-harmonic-generator (SHG) combination: i) combining 2 SHG of 1.55-μm erbium-doped fiber amplifiers in PPLN crystals generating 775-nm beams; ii) combining 2 SHG of 1.064-μm ytterbium-doped fiber amplifiers in LBO crystals generating 532-nm beams. Excellent CBC efficiency is achieved on the harmonic waves in both these experiments, with λ/20 and λ/30 residual phase error respectively. In the second experiment, I/Q phase detection is added on fundamental and harmonic waves to measure their phase variations simultaneously. These measurements confirm the theoretical expectations and formulae of correlation between the phases of the fundamental and harmonic waves. Unexpectedly, in both experiments, when harmonic waves are phase-locked, a residual phase difference remains between the fundamen tal waves. Measurements of the spectrum of these residual phase differences locate them above 50 Hz, revealing that they most probably originate in fast-varying optical path differences induced by turbulence and acoustic-waves on the experimental breadboard.

  17. Optically-electrically pumped THz source

    NASA Astrophysics Data System (ADS)

    Haji-Saeed, Bahareh; Khoury, Jed; Buchwald, Walter; Woods, Charles; Wentzell, Sandra; Krejca, Brian; Kierstead, John

    2010-08-01

    In this paper, we propose a design for a widely tunable solid-state optically and electrically pumped THz source based on the Smith-Purcell free-electron laser. Our design consists of a thin dielectric layer sandwiched between an upper corrugated structure and a lower layer of thin metal, semiconductor, or high electron mobility material. The lower layer is for current streaming, which replaces the electron beam in the Smith-Purcell free-electron laser design. The upper layer consists of two micro-gratings for optical pumping, and a nano-grating to couple with electrical pumping in the lower layer. The optically generated surface plasmon waves from the upper layer and the electrically induced surface plasmon waves from the lower layer are then coupled. Emission enhancement occurs when the plasmonic waves in both layers are resonantly coupled.

  18. Electronically tunable fiber laser for optical pumping of {sup 3}He and {sup 4}He

    SciTech Connect

    Stephens, E.F.; Patrick, H.; Gilbert, S.L.

    1996-03-01

    We present in this paper a low threshold, highly stable, integrated fiber laser cavity that uses an electronically tunable internal Bragg grating. The fiber laser produced over 5 mW with a spectral width of about 5 GHz at 1083 nm. The laser was used to achieve 30{percent} polarization of the 2{sup 3}{ital S}{sub 1} metastable states of {sup 4}He in a weak rf discharge cell. {copyright} {ital 1996 American Institute of Physics.}

  19. Efficient diode-pumped acousto-optic Q-switched Er:Yb:GdAl(3)(BO(3))(4) pulse laser at 1522  nm.

    PubMed

    Chen, Y J; Lin, Y F; Huang, J H; Gong, X H; Luo, Z D; Huang, Y D

    2015-11-01

    End-pumped by a continuous-wave 976 nm diode laser, efficient 1522 nm laser operation was demonstrated in an Er:Yb:GdAl(3)(BO(3))(4) crystal when a sapphire crystal was used as a heat diffuser. A continuous-wave 1522 nm laser with a maximum output power of 750 mW and slope efficiency of 36% was realized at an absorbed pump power of 4.1 W. The pulse performances of an acousto-optic Q-switched laser with various repetition frequencies were investigated in detail. In a repetition frequency range of 1-10 kHz, 1522 nm pulse lasers with a slope efficiency of about 10%, peak output power at the kilowatt level, and width of about 50 ns were first obtained in an Er:Yb:GdAl(3)(BO(3))(4) crystal pumped by a continuous-wave diode laser. The results indicate that the crystal is a promising gain medium for an actively Q-switched 1.5 μm laser. PMID:26512485

  20. Optically pumped quantum-dot Cd(Zn)Se/ZnSe laser and microchip converter for yellow-green spectral region

    SciTech Connect

    Lutsenko, E V; Voinilovich, A G; Rzheutskii, N V; Pavlovskii, V N; Yablonskii, G P; Sorokin, S V; Gronin, S V; Sedova, I V; Kop'ev, Petr S; Ivanov, Sergei V; Alanzi, M; Hamidalddin, A; Alyamani, A

    2013-05-31

    The room temperature laser generation in the yellow-green ({lambda} = 558.5-566.7 nm) spectral range has been demonstrated under optical pumping by a pulsed nitrogen laser of Cd(Zn)Se/ZnSe quantum dot heterostructures. The maximum achieved laser wavelength was as high as {lambda} = 566.7 nm at a laser cavity length of 945 {mu}m. High values of both the output pulsed power (up to 50 W) and the external differential quantum efficiency ({approx}60%) were obtained at a cavity length of 435 {mu}m. Both a high quality of the laser heterostructure and a low lasing threshold ({approx}2 kW cm{sup -2}) make it possible to use a pulsed InGaN laser diode as a pump source. A laser microchip converter based on this heterostructure has demonstrated a maximum output pulse power of {approx}90 mW at {lambda} = 560 nm. The microchip converter was placed in a standard TO-18 (5.6 mm in diameter) laser diode package. (semiconductor lasers. physics and technology)

  1. High-peak-power optically pumped AlGaInAs eye-safe laser at 500-kHz repetition rate with an intracavity diamond heat spreader

    NASA Astrophysics Data System (ADS)

    Chen, Y.-F.; Su, K. W.; Chen, W. L.; Huang, K. F.; Chen, Y. F.

    2012-08-01

    We report on a compact efficient high-repetition-rate (>100 kHz) optically pumped AlGaInAs nanosecond eye-safe laser at 1525 nm. A diamond heat spreader bonded to the gain chip is employed to improve the heat removal. At a pump power of 13.3 W, the average output power at a repetition rate 200 kHz is up to 3.12 W, corresponding to a peak output power of 560 W. At a repetition rate 500 kHz, the maximum average power and peak power are found to be 2.32 W and 170 W, respectively.

  2. Highly efficient tabletop x-ray laser at {lambda}=41.8 nm in Pd-like xenon pumped by optical-field ionization in a cluster jet

    SciTech Connect

    Ivanova, E. P.

    2011-10-15

    The atomic-kinetic calculations of gain at 41.8 nm in Pd-like xenon are performed. The interpretation of known experiments has proved that x-ray laser in Pd-like xenon is feasible in the extremely wide range of atomic densities: 10{sup 17}{<=}[Xe{sup 8+}]{<=} 3 x 10{sup 19} cm{sup -3}. This result is due to the large cross sections (and rates) of level excitations in Pd-like xenon by electron impact. We propose a highly efficient tabletop x-ray laser pumped by optical-field ionization in a xenon cluster jet. The efficiency of {approx}0.5% is possible with a pump laser pulse energy of {>=}0.001 J and an intensity of {approx}10{sup 16} W/cm{sup 2}.

  3. Tunable femtosecond near-infrared source based on a Yb:LYSO-laser-pumped optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Wen-Long, Tian; Zhao-Hua, Wang; Jiang-Feng, Zhu; Zhi-Yi, Wei

    2016-01-01

    We demonstrate a widely tunable near-infrared source from 767 nm to 874 nm generated by the intracavity second harmonic generation (SHG) in an optical parametric oscillator pumped by a Yb:LYSO solid-state laser. The home-made Yb:LYSO oscillator centered at 1035 nm delivers an average power of 2 W and a pulse duration as short as 351 fs. Two MgO doped periodically poled lithium niobates (MgO:PPLN) with grating periods of 28.5-31.5 μm in steps of 0.5 μm and 19.5-21.3 μm in steps of 0.2 μm are used for the OPO and intracavity SHG, respectively. The maximum average output power of 180 mW at 798 nm was obtained and the output pulses have pulse duration of 313 fs at 792 nm if a sech2-pulse shape was assumed. In addition, tunable signal femtosecond pulses from 1428 nm to 1763 nm are also realized with the maximum average power of 355 mW at 1628 nm. Project supported by the National Key Basic Research Program of China (Grant No. 2013CB922402), the National Key Scientific Instruments Development Program of China (Grant No. 2012YQ120047), the National Natural Science Foundation of China (Grant Nos. 61205130 and 11174361), and the Key Deployment Project of Chinese Academy of Sciences (Grant No. KJZD-EW-L11-03).

  4. Optically pumped quantum-dot Cd(Zn)Se/ZnSe laser and microchip converter for yellow—green spectral region

    NASA Astrophysics Data System (ADS)

    Lutsenko, E. V.; Voinilovich, A. G.; Rzheutskii, N. V.; Pavlovskii, V. N.; Yablonskii, G. P.; Sorokin, S. V.; Gronin, S. V.; Sedova, I. V.; Kop'ev, Petr S.; Ivanov, Sergei V.; Alanzi, M.; Hamidalddin, A.; Alyamani, A.

    2013-05-01

    The room temperature laser generation in the yellow—green (λ = 558.5-566.7 nm) spectral range has been demonstrated under optical pumping by a pulsed nitrogen laser of Cd(Zn)Se/ZnSe quantum dot heterostructures. The maximum achieved laser wavelength was as high as λ = 566.7 nm at a laser cavity length of 945 μm. High values of both the output pulsed power (up to 50 W) and the external differential quantum efficiency (~60%) were obtained at a cavity length of 435 μm. Both a high quality of the laser heterostructure and a low lasing threshold (~2 kW cm-2) make it possible to use a pulsed InGaN laser diode as a pump source. A laser microchip converter based on this heterostructure has demonstrated a maximum output pulse power of ~90 mW at λ = 560 nm. The microchip converter was placed in a standard TO-18 (5.6 mm in diameter) laser diode package.

  5. 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).

  6. 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.

  7. High power cooled mini-DIL pump lasers

    NASA Astrophysics Data System (ADS)

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

    2009-11-01

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

  8. 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.

  9. Power scaling of semiconductor laser pumped Praseodymium-lasers

    NASA Astrophysics Data System (ADS)

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

    2007-04-01

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

  10. First order distributed feedback dye laser effect in reflection pumping geometry for nonlinear optical measurements

    NASA Astrophysics Data System (ADS)

    Chen, F.; Gindre, D.; Nunzi, J.-M.

    2007-09-01

    Tunable distributed feedback (DFB) lasing output based on reflection grating configuration instead of the traditional transmission grating type was realized from rhodamine 6G (R6G)-doped ethanol and DCM-doped methanol. Pure gain coupling and additional index coupling were obtained in R6G-doped ethanol and DCM-doped methanol, respectively. The tuning which was independent on the refractive index of the lasing media went through all of the tuning data for the two cases. Dual-peak lasing emissions indicative of the existence of the index grating from the DCM-doped methanol were observed. The interval between the dual peaks increased as the increasing of the pump energy. The effect can be used to estimate the resonant nonlinear refractive index of luminescent materials.

  11. Optical fiber laser

    SciTech Connect

    Snitzer, E.

    1988-10-25

    This patent describes an optical fiber laser comprising: a gain cavity including a single mode optical fiber of given length and index of refraction and a cladding surrounding the core and having an index of refraction lower than that of the core. The core comprising a host material having incorporated therein a predetermined concentration of just erbium oxide having a fluorescence spectrum with a peak emission line at 1.54 micrometers; filter means optically coupled to each end of the fiber gain cavity for providing feedback in the cavity at the peak emission line of the erbium oxide and for permitting energy to be introduced into the cavity at the absorption band of the erbium oxide in the region of 1.45 to 1.53 micrometers; and a laser diode optically coupled to one end of the core for pumping energy into the end of the gain cavity so that the gain cavity oscillates at just the peak emission line.

  12. Optical Pumping of Mesospheric Sodium: a New Measurement Capability

    NASA Technical Reports Server (NTRS)

    Heinrichs, R. M.; Jeys, T. H.; Wall, K. F.; Korn, J.; Hotaling, T. C.

    1992-01-01

    The first observation of laser-induced optical pumping in a remote sensing application is reported. We have observed a large variation in the amount of laser light resonantly backscattered from the earth's mesospheric sodium layer depending on the laser polarization. This is consistent with optical pumping of the mesospheric sodium atoms. A new lidar capability is being developed based on measurements of the rethermalization rate of the optically pumped sodium atoms. These measurements have potential applications in the fields of global warming research, spacecraft re-entry, and upper atmospheric dynamics.

  13. 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.

  14. High-power multichannel PPMgLN-based optical parametric oscillator pumped by a master oscillation power amplification-structured Q-switched fiber laser.

    PubMed

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

    2012-10-01

    We experimentally demonstrated a compact fiber laser-pumped multichannel PPMgLN-based optical parametric oscillator (OPO) generating total OPO output power of 15.8, 15.2, 14.2, 12.9, and 8.8 W with idler output power of 4.7, 4.3, 4.1, 3.3, and 2.1 W at the wavelength of 3.43, 3.63, 3.72, 3.83, and 3.99 μm, respectively. The OPO was pumped by a fully fiberized polarization maintaining (PM) ytterbium-doped pulsed fiber master oscillation power amplifier (MOPA) operating at 1064 nm at a repetition rate of 65 kHz with effective pump power of 28.7 W. The MOPA system was constructed with an acousto-optic Q-switched fiber laser seed and only one stage PM fiber amplifier without any free space components, which makes the pump system compact and stable in the long-term. Comparisons on efficiencies and signal wavelength shifts between different channels showed that the idler absorption was the main factor preventing high average-power OPO operation with long idler wavelength. PMID:23033106

  15. 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.

  16. Broadband high-power mid-IR femtosecond pulse generation from an ytterbium-doped fiber laser pumped optical parametric amplifier.

    PubMed

    Hu, Chengzhi; Chen, Tao; Jiang, PeiPei; Wu, Bo; Su, Jianjia; Shen, Yonghang

    2015-12-15

    We report on a high-power periodically poled MgO-doped lithium niobate (MgO:PPLN)-based femtosecond optical parametric amplifier (OPA), featuring a spectral seamless broadband mid-infrared (MIR) output. By modifying the initial chirp and spectrum of the mode-locked seed laser, the Yb fiber pump laser exhibits a final output power of 14 W with sub-200-fs pulse duration after power amplification and compression. When the OPA was seeded with a broadband amplified spontaneous emission (ASE) source, a damage-limited 0.6 W broadband MIR radiation was experimentally obtained under the pump power of 10.15 W at 82 MHz repetition rate, corresponding to an overall OPA conversion efficiency of 32.7%. The 3 dB bandwidth of the mid-IR idler was 291.9 nm, centering at 3.34 μm. PMID:26670509

  17. 10 W mid-IR optical parametric oscillator pumped by a passively Q-switched Ho:YAG ceramic laser

    NASA Astrophysics Data System (ADS)

    Yuan, Jin-He; Duan, Xiao-Ming; Yao, Bao-Quan; Li, Jiang; Li, Chao-Yu; Pan, Yu-Bai

    2016-02-01

    We report on a ZnGeP2 (ZGP) optical parametric oscillator (OPO) pumped by a Cr2+:ZnS saturable absorbed passively Q-switched (PQS) Ho:YAG ceramic laser. The maximum output power of the ZGP OPO was 10 W at a 27.4 W incident PQS Ho:YAG ceramic laser, corresponding to a slope efficiency of 41.3% with respect to the incident pump power. The minimum mid-IR pulse width of 21 ns in 3.8 and 4.6 μm was obtained from the ZGP OPO. The beam quality was measured to be M 2  <  3.22.

  18. Optical pumping in semiconductors

    NASA Astrophysics Data System (ADS)

    Hermann, C.; Lampel, G.; Safarov, V. I.

    Optical Pumping in Semiconductors (OPS) arises from the transfer of angular momentum from light to the localized states of a semiconductor. Spin polarized electrons are thus excited in the conduction band; their polarization is convenient measured through the circular polarization of photoluminescence. This review gives an insight of the various studies based on OPS. After describing the first OPS experiment, we show that this technique allows the determination of band structure properties, and the optical detection of conduction electron spin resonance. The nuclei are polarized by hyperfine interaction, which permits the optical detection of nuclear resonance. A magnetic field transverse to the direction of light propagation produces an electronic depolarization analogous to the Hanle effect. The electron lifetime and spin relaxation time are measured under steady-state conditions by comparison to their Larmor frequency in this transverse field. By activation to Negative Electron Affinity of a GaAs surface, electrons oriented by OPS can be photoemitted into vacuum, leading to a highly spin-polarized beam : we describe a collision experiment in which such a beam transfers angular momentum to atoms. Le Pompage Optique dans les semiconducteurs (POS) provient du transfert de moment angulaire de la lumière vers les états délocalisés d'un semiconducteur. On excite ainsi dans la bande de conduction des électrons polarisés de spin, dont on mesure commodément la polarisation à partir de la polarisation circulaire de la photoluminescence. Cet article de revue présente un aperçu des différentes études fondées sur le POS. Après avoir décrit la première expérience de POS, nous montrons que par cette technique on peut déterminer des propriétés liées à la structure de bande, et détecter optiquement la résonance de spin des électrons de conduction. Les noyaux sont polarisés grâce au couplage hyperfin qui permet également la détection optique de la r

  19. 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.

  20. 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.

  1. 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.

  2. Single-frequency tunable laser for pumping cesium frequency standards

    SciTech Connect

    Zhuravleva, O V; Ivanov, Andrei V; Leonovich, A I; Kurnosov, V D; Kurnosov, K V; Chernov, Roman V; Shishkov, V V; Pleshanov, S A

    2006-08-31

    A single-frequency tunable laser for pumping the cesium frequency standard is studied. It is shown experimentally that the laser emits at a single frequency despite the fact that a few longitudinal modes of the external cavity fall within the reflection band of a fibre Bragg grating (FBG) written in the optical fibre. The laser wavelength can be tuned by varying the pump current of the laser, its temperature, and the FBG temperature. The laser linewidth does not exceed 2 MHz for 10 mW of output power. (lasers)

  3. Spin-polarized /sup 3/He nuclear targets and metastable /sup 4/He atoms by optical pumping with a tunable, Nd:YAP laser

    SciTech Connect

    Bohler, C.L.; Schearer, L.D.; Leduc, M.; Nacher, P.J.; Zachorowski, L.; Milner, R.G.; McKeown, R.D.; Woodward, C.E.

    1988-04-15

    Several Nd:YAP lasers were constructed which could be broadly tuned in the 1083-nm region which includes the helium 2/sup 3/S-2/sup 3/P transition, using a Lyot filter and thin, uncoated etalons within the laser cavity. 1 W of power could be extracted at 1083 nm through a 1% transmitting output coupler. This laser beam was used to optically pump metastable /sup 4/He and /sup 3/He 2/sup 3/S helium atoms in a weak discharge cell, spin polarizing the metastable ensemble. In a /sup 3/He cell the polarization is transferred to the nuclear spin system. A /sup 3/He target cell at 0.3 Torr was polarized to 52% in a few minutes. We describe the application of this system to the design of polarized targets for experiments in nuclear physics.

  4. Optical pumping and xenon NMR

    SciTech Connect

    Raftery, M.D.

    1991-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping [sup 129]Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the [sup 131]Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

  5. Optical pumping and xenon NMR

    SciTech Connect

    Raftery, M.D.

    1991-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping {sup 129}Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the {sup 131}Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

  6. Multi-lamp laser pumping cavity

    SciTech Connect

    Kuppenheimer, J.D. Jr.

    1987-07-21

    An optically pumped laser comprises: A. a cylindrical laser rod having a longitudinal central rod axis; B. cylindrical lamps for optically pumping the laser rod. The lamps have longitudinal central lamp axes parallel to the rod axis. The lamps being so located with respect to each other and to the laser rod as to define in cross section a base line associated with each lamp and extending between the rod axis and the lamp axis of the associated lamp. The base lines being equal in length and equiangularly spaced; and C. a reflector wall consisting essentially of first and second wall sections associated with each lamp, the cross sections of the first and second wall sections associated with a given lamp essentially following first and second curves extending from a lamp cusp associated with the given lamp to second and first rod cusps, respectively, associated with the given lamp. The first and second curves consist of the loci of points to which the sums of the distances, exterior to the laser rod and the given lamp, from first and second rod starting points, respectively, associated with the given lamp and from first and second lamp starting points, respectively, on the given lamp equal a fixed quantity.

  7. Efficient pumping of inertial fusion energy lasers

    NASA Astrophysics Data System (ADS)

    Wessling, C.; Rübenach, O.; Hambücker, S.; Sinhoff, V.; Banerjeea, S.; Ertel, K.; Mason, P.

    2013-02-01

    Solid-state lasers have been demonstrated as attractive drivers for laser-plasma interaction and have presently been developed for various applications like inertial confinement fusion (ICF) [1], particle acceleration and intense X-ray generation [3]. Viable real world applications like power production at industrial scale will require high laser system efficiency, repetition rate and lifetime which are only possible with semiconductor diode pumping. The paper describes the work conducted with two 20 kW diode laser sources pumping an ytterbium:YAG laser amplifier. The set-up acts as a small scale prototype for the DiPOLE project [2]. This project aims to develop scalable gas cooled cryogenic multi-slab diode pumped solid state lasers capable of producing KJ pulse energy. A scale-down prototype is currently under development at the Central Laser Facility (CLF) designed to generate 10 J at 10 Hz. To secure an efficient pumping process the sources have to fulfill aside power requirement in the spectral and time domain, the claim for high homogenization and low divergence of the spatial and angular beam distribution as well as a minimization of losses within the optical path. The existing diode laser sources designed and built by INGENERIC deliver 20 kW pulsed power, concentrated on a plateau of FWHM dimension of 20 x 20 mm² with a homogeneity of more than 90 %. The center wavelength of 939.5 nm is controlled in a range of ± 0.1 nm. The time and area integrated spectrum of at least 76 % of the total energy is contained within a 6 nm wide wavelength band around the center wavelength. Repetition rates can be adjusted between 0.1 Hz up to 10 Hz with rise and fall times less than 50 μs and pulse durations from 0.2 ms to 1.2 ms. The paper describes the impact of different designs on the performance of pump sources and puts special emphasis on the influence of the optical components on efficiency and performance. In addition the influence of the measuring principle is

  8. 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.

  9. Research of the quenched dye lasers pumped by excimer lasers

    SciTech Connect

    Xue Shaolin; Lou Qihong

    1996-12-31

    In this paper, the quenched dye lasers pumped by XeCl and KrF excimer lasers were investigated theoretically and experimentally. Dye laser pulses with duration of 0.8 ns for XeCl laser pumping and 2 ns for KrF laser pumping were obtained. The dye Rhodamine 6G dissolved in methyl was used as the active medium in the quenched dye laser. When the pump laser was KrF and the active medium was Coumarin 498 the quenched dye laser emitted pulse with duration of about 2 ns. The characteristics of the quenched dye laser was also investigated in detail.

  10. Diode-pumped acousto-optically Q-switched high-repetition-rate Nd:YAG lasers at 946 and 473 nm by intracavity frequency-doubling

    NASA Astrophysics Data System (ADS)

    Chen, F.; Yu, X.; Guo, J.; Guo, L. H.; Yang, G. L.; Xie, J. J.; Zhang, L. M.; Geng, Y. M.; Li, S. M.; Li, D. J.; Shao, C. L.; Meng, F. J.; Zhang, C. S.; Yan, R. P.

    2011-10-01

    A diode-pumped acousto-optically (AO) Q-switched high-repetition-rate Nd:YAG lasers at 946 and 473 nm by intracavity frequency-doubling were reported in this paper. Using a compact V-type laser cavity, a maximum average output power of 4.5 W 946 nm laser was obtained at an operating repetition rate of 10 kHz, corresponding to an optical conversion efficiency of 10.5% and a slope efficiency of 15.6%. With a BiBO crystal as the intracavity frequency-doubler, 1.35 W 473 nm pulsed laser was achieved at 10 kHz. The peak power of the Q-switched blue pulse was up to 4.1 kW, with a pulse width of 33.1 ns. Then, the long-term power instability was less than 1%. Moreover, stable pulsed operation of 946 nm and 473 nm lasers can even reach 50 kHz.

  11. 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.

  12. 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.

  13. The optical pumping of alkali atoms using coherent radiation from semi-conductor injection lasers and incoherent radiation from resonance lamps

    NASA Technical Reports Server (NTRS)

    Singh, G.

    1973-01-01

    An experimental study for creating population differences in the ground states of alkali atoms (Cesium 133) is presented. Studies made on GaAs-junction lasers and the achievement of population inversions among the hyperfine levels in the ground state of Cs 133 by optically pumping it with radiation from a GaAs diode laser. Laser output was used to monitor the populations in the ground state hyperfine levels as well as to perform the hyperfine pumping. A GaAs laser operated at about 77 K was used to scan the 8521 A line of Cs 133. Experiments were performed both with neon-filled and with paraflint-coated cells containing the cesium vapor. Investigations were also made for the development of the triple resonance coherent pulse technique and for the detection of microwave induced hyperfine trasistions by destroying the phase relationships produced by a radio frequency pulse. A pulsed cesium resonance lamp developed, and the lamp showed clean and reproducible switching characteristics.

  14. 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.

  15. Diode pumped thin slab solid-state lasers

    NASA Astrophysics Data System (ADS)

    Cheng, Xiaojin; Wang, Zhiming; Chen, Fan; Xu, Jianqiu

    2008-12-01

    Thermal effect is a serious problem in solid-state lasers. Because of superior thermal property which owed to high aspect ratio of laser crystal, solid-state lasers with thin slab configuration can be scaling to high output power with different laser crystal material and pump structure. In this paper, we present side-pumped passive Q-switched and acousto-optic Q-switched Nd: YAG lasers and end-pumped Tm: YAP lasers. We got a maximum 70W output power of passive Q-switched Nd: YAG laser with 220W pump power, which the pulse duration is around 10ns and the pulse repetition rate is higher than 10kHz. And 73W output power is got while pump power is 200W in acousto-optic Q-switched Nd: YAG lasers. Especially, we also applied the thin slab configuration to end pumped Tm: YAP laser and got a maximum 9.6W output power which the doping concentrations is 4% and cut by c-axis.

  16. Cs laser with unstable cavity transversely pumped by multiple diode lasers.

    PubMed

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

    2009-08-17

    We have demonstrated a Cs vapor laser with an unstable resonator transversely pumped by 15 narrowband laser diode arrays. A slope efficiency of 43%, a total optical efficiency of 31% and a maximum output power 49 W were obtained with a pump power of 157 Watts. PMID:19687954

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  20. 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

  1. 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.

  2. Laser-Induced Optical Pumping Measurements of Cross Section for Fine- and Hyperfine-Structure Transitions in Sodium Induced by Collisions with Helium and Argon Atoms

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.; Sung, C. C.

    1999-01-01

    Optical pumping of the ground states of sodium can radically alter the shape of the laser-induced fluorescence excitation spectrum, complicating measurements of temperature, pressure, etc., which are based on these spectra. Modeling of the fluorescence using rate equations for the eight hyperfine states of the sodium D manifolds can be used to quantify the contribution to the ground state pumping of transitions among the hyperfine excited states induced by collisions with buffer gas atoms. This model is used here to determine, from the shape of experimental spectra, cross sections lor DELTA.F transitions of the P(sub 3/2) state induced by collisions with helium and argon atoms, for a range of values assumed for the P(sub 1/2), DELTA.F cross sections. The hyperfine cross sections measured using this method, which to our knowledge is novel, are compared with cross sections for transitions involving polarized magnetic substates m(sub F) measured previously using polarization sensitive absorption. Also, fine-structure transition cross sections were measured in the pumped vapor, giving agreement with previous measurements made in the absence of pumping.

  3. Laser Induced Optical Pumping Measurements of Cross Sections for Fine and Hyperfine Structure Transitions in Sodium Induced by Collisions with Helium Argon Atoms

    NASA Technical Reports Server (NTRS)

    Dobson, Chris C.; Sung, C. C.

    1998-01-01

    Optical pumping of the ground states of sodium can radically alter the shape of the laser induced fluorescence excitation spectrum, complicating measurements of temperature, pressure, etc., which are based on these spectra. Modeling of the fluorescence using rate equations for the eight hyperfine states of the sodium D manifolds can be used to quantify the contribution to the ground state pumping of transitions among the hyperfine excited states induced by collisions with buffer gas atoms. This model is used here to determine, from the shape of experimental spectra, cross sections for (Delta)F transitions of the P(sub 3/2) state induced by collisions with helium and argon atoms, for a range of values assumed for the P(sub 1/2), (Delta)F cross sections. The hyperfine cross sections measured using this method, which is thought to be novel, are compared with cross sections for transitions involving polarized magnetic substates, m(sub F), measured previously using polarization sensitive absorption. Also, fine structure transition ((Delta)J) cross sections were measured in the pumped vapor, giving agreement with previous measurements made in the absence of pumping.

  4. Resonant tandem pumping of Tm-doped fiber lasers

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    We have demonstrated efficient lasing of a Tm-doped fiber when pumped with another Tm-doped fiber. In these experiments, we use a 1908 nm Tm-doped fiber laser as a pump source for another Tm-doped fiber laser, operating at a slightly longer wavelength (~2000 nm). Pumping in the 1900 nm region allows for very high optical efficiencies, low heat generation, and significant power scaling potential due to the use of fiber laser pumping. The trade-off is that the ground-state pump absorption at 1908 nm is ~37 times lower than at 795nm. However, the absorption cross-section is still sufficiently high enough to achieve effective pump absorption without exceedingly long fiber lengths. This may also be advantageous for distributing the thermal load in higher power applications.

  5. Highly efficient tunable mid-infrared optical parametric oscillator pumped by a wavelength locked, Q-switched Er:YAG laser.

    PubMed

    Liu, Jun; Tang, Pinghua; Chen, Yu; Zhao, Chujun; Shen, Deyuan; Wen, Shuangchun; Fan, Dianyuan

    2015-08-10

    A highly efficient and stable mid-infrared optical parametric oscillator is demonstrated, pumped by an electro-optic Q-switched Er:YAG laser with operating wavelength locked at 1645 nm by a volume Bragg grating. The oscillator, based on MgO-doped periodically poled lithium niobate (MgO:PPLN) crystal, yields a maximum overall average output power in excess of 1 W, corresponding to a conversion efficiency of 35.5% and a slope efficiency of 43.6%. The signal and idler wavelengths of the OPO are around ~2.7 μm and ~4.3 μm, respectively, corresponding to the two peak absorption bands of CO(2). Lasing characteristics of the oscillator, including the time evolution of the pump, signal and idler pulses at different pump power levels, are also investigated. Temperature tuning of the MgO:PPLN crystal gives signal and idler ranges of 2.67 to 2.72 μm and 4.17 to 4.31 μm, respectively. PMID:26367934

  6. Diode-end-pumped, electro-optically Q-switched Nd:YVO4 slab laser and its second-harmonic generation.

    PubMed

    Zhang, Hengli; Shi, Peng; Li, Daijun; Du, Keming

    2003-03-20

    We describe the operation of a near-diffraction-limited, 1,064-nm electro-optically Q-switched Nd:YVO4 slab laser that is end pumped by laser-diode stacks and its efficient second-harmonic generation by using a lithium triborate (LBO) crystal. The energy per pulse of 3.6 and 0.8 mJ and pulse widths of 5 and 13.5 ns were obtained at repetition of 5 and 40 kHz, respectively. With a LBO crystal, a maximum output power of 15.6 W at 532 nm was obtained at the repetition rate of 40 kHz, the corresponding conversion efficiency was 60%, and the pulse width was 11.3 ns. At 10 kHz, the pulse energy of 532 nm was 1.2 mJ, and the pulse width was 5 ns. PMID:12665098

  7. Exploring the influence of high order transverse modes on the temporal dynamics in an optically pumped mode-locked semiconductor disk laser.

    PubMed

    Tsou, C H; Liang, H C; Wen, C P; Su, K W; Huang, K F; Chen, Y F

    2015-06-15

    We quantitatively investigate the influence of high-order transverse modes on the self-mode locking (SML) in an optically pumped semiconductor laser (OPSL) with a nearly hemispherical cavity. A physical aperture is inserted into the cavity to manipulate the excitation of high-order transverse modes. Experimental measurements reveal that the laser is operated in a well-behaved SML state with the existence of the TEM(0,0) mode and the first high-order transverse mode. While more high-order transverse modes are excited, it is found that the pulse train is modulated by more beating frequencies of transverse modes. The temporal behavior becomes the random dynamics when too many high-order transverse modes are excited. We observe that the temporal trace exhibits an intermittent mode-locked state in the absence of high-order transverse modes. PMID:26193606

  8. An eye-safe KTiAsO 4 intracavity optical parametric oscillator driven by a diode pumped composite Nd:YAG/Cr 4+:YAG laser

    NASA Astrophysics Data System (ADS)

    Huang, Haitao; He, Jingliang; Zhang, Baitao; Xu, Jinlong; Yang, Jianfei; Wang, Haixia; Zhao, Shuang

    2010-11-01

    A mini eye-safe KTiAsO 4 intracavity optical parametric oscillator (IOPO) employing the shared cavity configuration and driven by a diode-end-pumped composite Nd:YAG/Cr 4+:YAG laser is demonstrated in this paper. Under an incident laser diode power of 11 W, a maximum average output power of 424 mW at 1534 nm was obtained. The corresponding signal pulse width and repetition rate were 1.2 ns and 16.7 kHz, respectively. The fluctuation of the average signal output power over long-term operation was found to be ±3.0%. A theoretical model for the compact IOPO was also presented in this paper.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Direct pumping of ultrashort Ti:sapphire lasers by a frequency doubled diode laser

    NASA Astrophysics Data System (ADS)

    Müller, André; Jensen, Ole B.; Unterhuber, Angelika; Le, Tuan; Stingl, Andreas; Hasler, Karl-Heinz; Sumpf, Bernd; Erbert, Götz; Andersen, Peter E.; Petersen, Paul M.

    2011-12-01

    A simple and robust diode laser system emitting 1.28 W of green light suitable for pumping an ultrafast Ti:sapphire laser is presented. To classify our results, the diode laser is compared to a standard, commercially available diode pumped solid-state (DPSS) laser system pumping the same oscillator. When using our diode laser system, the optical conversion efficiencies from green to near-infrared light reduces to 75 % of the values achieved with the commercial pump laser. Despite this reduction the overall efficiency of the Ti:sapphire laser is still increased by a factor > 2 due to the superior electro-optical efficiency of the diode laser. Autocorrelation measurements show that pulse widths of less than 20 fs can be expected with an average power of 52 mW when using our laser. These results indicate the high potential of direct diode laser pumped Ti:sapphire lasers to be used in applications like retinal optical coherence tomography (OCT) or pumping of photonic crystal fibers for CARS (coherent anti-stokes Raman spectroscopy) microscopy.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Solar-pumped Nd:Cr:GSGG parallel array laser

    NASA Astrophysics Data System (ADS)

    Thompson, George A.; Krupkin, V.; Yogev, Amnon; Oron, Moshe

    1992-12-01

    A compact, parallel array of three Nd:Cr:GSGG laser rods is used to construct a quasi-CW laser. The array is pumped by concentrated solar light and is mounted in a single concentrator. The three laser rods use a common pair of laser mirrors to define the optical resonator. The three laser beams are not coherently coupled in these experiments. The simplicity of the design, and its reasonable stability in terms of vibration and optical misalignment, suggest that the design may be scalable for higher power.

  1. 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.

  2. 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.

  3. Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1987-01-01

    Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

  4. Optical fiber laser

    SciTech Connect

    Hakimi, F.; Po, H.; Snitzer, E.

    1987-07-14

    An optical fiber laser is described comprising: a gain cavity including a single mode optical fiber of given length having a core with a given index of refraction and a cladding surrounding the core and having an index of refraction lower than that of the core. The core comprises a host glass having incorporated a laser gain material with a fluorescence spectrum having at least one broadband region in which there is at least one peak emission line; filter means optically coupled to one end of the gain cavity and reflective to radiation emitted from the gain material over a predetermined wavelength interval about the peak emission line to provide feedback in the gain cavity; an etalon filter section butt coupled to the remaining end of the gain cavity optical fiber, the etalon filter section comprising a pair of filters spaced apart in parallel by a predetermined length of material transparent to any radiation emitted from the gain cavity. The predetermined length of the transparent material is such that the etalon filter section is no longer than the distance over which the wave train energy from the fiber core remains substantially planar so that the etalon filter section is inside the divergent region to enhance feedback in the gain cavity; and means for pumping energy into the gain cavity to raise the interval energy level such that only a small part of the ion population, corresponding to a predetermined bandwidth about the peak emission line, is raised above laser threshold. The laser emits radiation only over narrow lines over a narrow wavelength interval centered about the peak emission line.

  5. 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.

  6. Highly Efficient Operation of Tm:fiber Laser Pumped Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Bai, Yingxin; Petros, M.; Yu, Jirong; Petzar, Paul; Trieu, Bo; Chen, Sam; Lee, Hyung; Singh, U.

    2006-01-01

    A 19 W, TEM(sub 00) mode, Ho:YLF laser pumped by continuous wave Tm:fiber laser has been demonstrated at the room temperature. The slope efficiency and optical-to-optical efficiency are 65% and 55%, respectively.

  7. 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. PMID:19997290

  8. Nd:YAG laser side pumped by diode laser arrays

    NASA Astrophysics Data System (ADS)

    Tan, Hua; Huang, Weiling; Zhou, Zhouyou; Wang, Hailin; Cao, Hongbing; Wang, Ying

    1999-09-01

    The major limitation of flashlamp-pumped solid-state lasers is the low overall efficiency. Replacing flashlamps with high power laser diodes allows an increase of system efficiency by over an order of magnitude. Because of the thermally induced stress fracture of the laser materials, power-scaling possibilities of end-pumped configurations are limited. Therefore side pump geometry has to be used for high power laser. The theory and the design of high power diode side-pumped Nd:YAG laser system is described. The Nd:YAG rod is side-pumped by diode laser arrays with wavelength at 808 nm. We analyze the result of our experiments and make some conclusions about the design of side-pumped laser.

  9. 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

  10. Optically pumped subwavelength-scale metallodielectric nanopatch resonators.

    PubMed

    Kwon, Kyungmok; You, Jong-Bum; Shim, Jaeho; Jung, Youngho; Yu, Kyoungsik

    2016-01-01

    We discuss subwavelength-scale semiconductor metal-optic resonators placed on the metal substrate with various top metal plate sizes. Albeit with large optical losses, addition of metal layers converts a leaky semiconductor nano-block into a highly-confined optical cavity. Optically pumped lasing action is observed with the extended top metal layer that can significantly suppress the radiation losses. Careful investigation of self-heating effects during the optical carrier injection process shows the importance of temperature-dependent material properties in the laser rate equation model and the overall laser performances. PMID:27549640

  11. Optically pumped subwavelength-scale metallodielectric nanopatch resonators

    PubMed Central

    Kwon, Kyungmok; You, Jong-bum; Shim, Jaeho; Jung, Youngho; Yu, Kyoungsik

    2016-01-01

    We discuss subwavelength-scale semiconductor metal-optic resonators placed on the metal substrate with various top metal plate sizes. Albeit with large optical losses, addition of metal layers converts a leaky semiconductor nano-block into a highly-confined optical cavity. Optically pumped lasing action is observed with the extended top metal layer that can significantly suppress the radiation losses. Careful investigation of self-heating effects during the optical carrier injection process shows the importance of temperature-dependent material properties in the laser rate equation model and the overall laser performances. PMID:27549640

  12. 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.

  13. Longwave-IR optical parametric oscillator in orientation-patterned GaAs pumped by a 2 µm Tm,Ho:YLF laser.

    PubMed

    Feaver, R K; Peterson, R D; Powers, P E

    2013-07-01

    We demonstrate longwave infrared (LWIR) generation with an optical parametric oscillator (OPO) based on quasi-phasematched orientation-patterned gallium arsenide (OPGaAs). The OPGaAs OPO was directly pumped with a Q-switched λ = 2.054 μm Tm,Ho:YLF laser. OPGaAs samples representing three different grating periods were used to explore the LWIR OPO performance yielding outputs ranging from λ = 2.5-2.7 μm (signal) and λ = 8.8-11.5 μm (idler). Slope efficiencies for the combined signal and idler outputs reach as high as 26% while slope efficiencies for only the idler reached 8%. Spectral measurements of OPO output confirm good agreement with theoretical calculations. PMID:23842397

  14. Stabilization of He2(A(sup 3)Sigma(sub u)(+)) molecules in liquid helium by optical pumping for vacuum UV laser

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J. S. (Inventor)

    1978-01-01

    A technique is disclosed for achieving large populations of metastable spin-aligned He2(a 3 Sigma u +) molecules in superfluid helium to obtain lasing in the vacuum ultraviolet wavelength regime around 0.0800 micron m by electronically exciting liquid (superfluid) helium with a comparatively low-current electron beam and spin aligning the metastable molecules by means of optical pumping with a modestly-powered (100mW) circularly-polarized continuous wave laser operating at, for example, 0.9096 or 0.4650 micron m. Once a high concentration of spin-aligned He2 (a 3 Sigma u +) is achieved with lifetimes of a few milliseconds, a strong microwave signal destroys the spin alignment and induces a quick collisional transition of He2 (a 3 Sigma u +) molecules to the a 1 Sigma u + state and thereby a lasing transition to the X 1 Sigma g + state.

  15. Design of multilamp nonimaging laser pump cavities

    SciTech Connect

    Kuppenheimer, J.D. Jr.

    1989-12-01

    A technique has been developed to design single laser rod, multiple flash lamp pump cavities that allow all of the energy generated by the lamp to pass through the laser rod before entering another lamp cavity. The effective lamp and rod perimeters are matched, guaranteeing maximal concentration and uniformity of pumping.

  16. 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.

  17. Engineering lattice matching, doping level, and optical properties of KY(WO4)2:Gd, Lu, Yb layers for a cladding-side-pumped channel waveguide laser

    NASA Astrophysics Data System (ADS)

    Aravazhi, Shanmugam; Geskus, Dimitri; van Dalfsen, Koop; Vázquez-Córdova, Sergio A.; Grivas, Christos; Griebner, Uwe; García-Blanco, Sonia M.; Pollnau, Markus

    2013-05-01

    Single-crystalline KY1- x-y-z GdxLuyYbz(WO4)2 layers are grown onto undoped KY(WO4)2 substrates by liquid-phase epitaxy. The purpose of co-doping the KY(WO4)2 layer with suitable fractions of Gd3+ and Lu3+ is to achieve lattice-matched layers that allow us to engineer a high refractive-index contrast between waveguiding layer and substrate for obtaining tight optical mode confinement and simultaneously accommodate a large range of Yb3+ doping concentrations by replacing Lu3+ ions of similar ionic radius for a variety of optical amplifier or laser applications. Crack-free layers, up to a maximum lattice mismatch of ~0.08 %, are grown with systematic variations of Y3+, Gd3+, Lu3+, and Yb3+ concentrations, their refractive indices are measured at several wavelengths, and Sellmeier dispersion curves are derived. The influence of co-doping on the spectroscopy of Yb3+ is investigated. As evidenced by the experimental results, the lattice constants, refractive indices, and transition cross-sections of Yb3+ in these co-doped layers can be approximated with good accuracy by weighted averages of data from the pure compounds. The obtained information is exploited to fabricate a twofold refractive-index-engineered sample consisting of a highly Yb3+-doped tapered channel waveguide embedded in a passive planar waveguide, and a cladding-side-pumped channel waveguide laser is demonstrated.

  18. REVIEW ARTICLE: Optical pumping-induced spatio-temporal modifications to propagation, polarization and intensity of laser beams in sodium vapour

    NASA Astrophysics Data System (ADS)

    Holzner, R.; Dangel, S.

    1998-02-01

    Circularly polarized laser beams propagating through sodium vapour and tuned to the buffer-gas-broadened atomic 1355-5111/10/1/003/img1 transition can optically pump sodium atoms into a non-absorbing ground state. This causes an intensity-dependent refractive index gradient along as well as transverse to the laser beam propagation direction, giving rise to a number of nonlinear spatio-temporal intensity and polarization pattern creating processes. In the case of a single circularly polarized laser beam we have observed self-focusing and defocusing, the transformation of the incident Gaussian beam intensity profiles into ring profiles, a large shift of about 5 GHz of the maximum of the absorption profile when suitable magnetic fields are applied and the deflection of a beam by the inhomogeneous transverse magnetic field of a current-carrying wire. When two beams of opposite circular polarization are superimposed, astonishing effects such as the mutual deflection of both beams (beam bouncing), the mutual extinction of both beams (beam switching), the separation of initially overlapping beams (beam splitting) and the mutual attraction of both beams (beam attraction) can be observed. While most of the effects can be well described for the stationary state by a 1355-5111/10/1/003/img2 to 1355-5111/10/1/003/img3 atomic transition model, the correct description of the dynamics requires the consideration of all hyperfine states.

  19. 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.

  20. 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.

  1. Pulsed Optically Pumped Rb clock

    NASA Astrophysics Data System (ADS)

    Micalizio, S.; Levi, F.; Godone, A.; Calosso, C. E.; François, B.; Boudot, R.; Affolderbach, C.; Kang, S.; Gharavipour, M.; Gruet, F.; Mileti, G.

    2016-06-01

    INRIM demonstrated a Rb vapour cell clock based on pulsed optical pumping (POP) with unprecedented frequency stability performances, both in the short and in the medium-long term period. In the frame of a EMRP project, we are developing a new clock based on the same POP principle but adopting solutions aimed at reducing the noise sources affecting the INRIM clock. At the same time, concerning possible technological applications, particular care are devoted in the project to reduce the size and the weight of the clock, still keeping the excellent stability of the INRIM clock. The paper resumes the main results of this activity.

  2. Crystal growth and near infrared optical properties of Pr 3+ doped lead halide materials for resonantly pumped eye safe laser applications

    NASA Astrophysics Data System (ADS)

    Jones, Ivy Krystal

    In this dissertation the material development and optical spectroscopy of Pr3+ activated low phonon energy halide crystals is presented for possible applications in resonantly pumped eye-safe solid-state laser gain media. In the last twenty years, the developments in fiber and diode lasers have enabled highly efficient resonant pumping of Pr3+ doped crystals for possible lasing in the 1.6--1.7 microm region. In this work, the results of the purification, crystal growth, and near-infrared (NIR) spectroscopic characterization of Pr3+ doped lead (II) chloride, PbCl2 and lead (II) bromide, PbBr2 are presented. The investigated PbCl2 and PbBr2 crystals are non-hygroscopic with maximum phonon energies between ~180--200 cm-1, which enable efficient emission in the NIR spectral region (~ 1.6 microm) from the 3F3/3F4 → 3H4 transition of Pr3+ ions. The commercial available starting materials were purchased as ultra dry, high purity (~ 99.999 %) beads and purified through a combination of zone-refinement and halogenation. The crystal growth of Pr3+ doped PbCl 2 and PbBr2 was performed via vertical Bridgman technique using a two-zone furnace. The resulting Pr3+ doped PbCl 2 and PbBr2 crystals exhibited characteristic IR absorption bands in the 1.5--1.7 microm region (3H4 → 3F3/3F4), which allow for resonant pumping using commercial diode lasers. A broad IR emission band centered at ~1.6 microm was observed under ~1445 nm diode laser excitation from both Pr3+ doped halides. This dissertation presents comparative spectroscopic results for Pr 3+:PbCl2 and Pr3+:PbBr2 including NIR absorption and emission studies, lifetime measurements, modelling of radiative and non-radiative decay rates, determination of transition cross-section, and the net effective gain cross sections.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Spatial Polarization Profile in an Optically Pumped Alkali Vapor

    NASA Astrophysics Data System (ADS)

    Olsen, Ben; Patton, Brian; Jau, Yuan-Yu; Happer, Will

    2009-05-01

    Spin-Exchange Optical Pumping (SEOP) is a technique used to polarize nuclei in gases, and more recently in solids, in excess of their equilibrium limit. SEOP is achieved by optically pumping an alkali vapor which subsequently transfers angular momentum to the nuclei of interest. The efficiency of SEOP is governed by optical pumping and relaxation of the alkali atoms, relaxation of the target nuclei, and interactions between the alkali and target substance. In this work we investigate the relationship between optical pumping and relaxation in cesium vapor with absorption spectroscopy at high magnetic field (2.7 T). Cesium vapor within a cylindrical glass vapor cell is optically pumped with a strong laser resonant with a D2 transition. The ground-state population of the vapor is measured at various positions along a diameter of the cell with a small, weak D1 laser beam which translates mechanically. The resulting polarization profile elucidates the interplay between optical pumping, diffusion in the buffer gas, and relaxation at the walls of the vapor cell. We report measurements of the spatial polarization profile in vapor cells with bare Pyrex walls and cells coated with paraffin (an anti-relaxation coating) or CsH salt (a target substance for SEOP), and compare them to numerical simulations. Further investigation might yield a new method for characterizing surface relaxation in vapor cells.

  8. 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.

  9. GaAs laser diode pumped Nd:YAG laser

    NASA Technical Reports Server (NTRS)

    Conant, L. C.; Reno, C. W.

    1974-01-01

    A 1.5-mm by 3-cm neodymium-ion doped YAG laser rod has been side pumped using a GaAs laser diode array tuned to the 8680-A absorption line, achieving a multimode average output power of 120 mW for a total input power of 20 W to the final-stage laser diode drivers. The pumped arrangement was designed to take advantage of the high brightness of a conventional GaAs array as a linear source by introducing the pump light through a slit into a close-wrapped gold coated pump cavity. This cavity forms an integrating chamber for the pump light.

  10. Optical pumping in a whispering-mode optical waveguide

    DOEpatents

    Kurnit, N.A.

    1981-08-11

    A device and method for optical pumping in a whispering mode optical waveguide are described. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction path lengths which are achieved in a small volume.

  11. Optical pumping in a whispering mode optical waveguide

    DOEpatents

    Kurnit, Norman A.

    1984-01-01

    A device and method for optical pumping in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction pathlengths which are achieved in a small volume.

  12. Efficient emission at 1908 nm in a diode-pumped Tm:YLF laser

    SciTech Connect

    Zakharov, N G; Antipov, Oleg L; Savikin, A P; Sharkov, V V; Eremeikin, O N; Frolov, Yu N; Mishchenko, G M; Velikanov, S D

    2009-05-31

    Emission parameters at 1908 nm in a longitudinally-diode-pumped Tm:YLF laser are studied. The laser parameters are optimised to obtain the maximal power of high-quality cw radiation. The output power of {approx}27 W is obtained at the slope efficiency of {approx}50% and total optical pump conversion efficiency of {approx}41%. (lasers and amplifiers)

  13. Temperature distribution of laser crystal in LD end-pumped Nd:YAG/LBO blue laser

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Zheng, Yibo; Li, Simian; Jia, Liping; Kang, Junjian

    2012-11-01

    In this study, LD end-pumped Nd:YAG/LBO solid state blue laser is realized by even hollow cavity. A thermal distribution model of Nd:YAG crystal is established. Based on the calculation, the temperature distribution of laser crystal is obtained. The results show that the temperature decreases from the pump end to the launch end exponentially. When the pumping power is 10 W and the radius of pumping beams is 240μm, a biggest output power 1.06 W of blue light is achieved, giving an optical conversion efficiency of 10.6%.

  14. 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. PMID:19571944

  15. Resonant pumped erbium-doped waveguide lasers using distributed Bragg reflector cavities.

    PubMed

    Singh, G; Purnawirman, P; Bradley, J D B; Li, N; Magden, E S; Moresco, M; Adam, T N; Leake, G; Coolbaugh, D; Watts, M R

    2016-03-15

    This Letter reports on an optical pumping scheme, termed resonant pumping, for an erbium-doped distributed feedback (DFB) waveguide laser. The scheme uses two mirrors on either side of the DFB laser, forming a pump cavity that recirculates the unabsorbed pump light. Symmetric distributed Bragg reflectors are used as the mirrors and are designed by matching the external and internal quality factors of the cavity. Experimental demonstration shows lasing at an optical communication wavelength of around 1560 nm and an improvement of 1.8 times in the lasing efficiency, when the DFB laser is pumped on-resonance. PMID:26977666

  16. 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%.

  17. Method and system for homogenizing diode laser pump arrays

    DOEpatents

    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%.

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

    PubMed

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

    2015-02-01

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

  20. 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.

  1. Theoretcial studies of solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Fong, Z. S.

    1984-01-01

    A method of pumping a COhZ laser by a hot cavity was demonstrated. The cavity, heated by solar radiation, should increase the efficiency of solar pumped lasers used for energy conversion. Kinetic modeling is used to examine the behavior of such a COhZ laser. The kinetic equations are solved numerically vs. time and, in addition, steady state solutions are obtained analytically. The effect of gas heating filling the lower laser level is included. The output power and laser efficiency are obtained as functions of black body temperature and gas ratios (COhZ-He-Ar) and pressures. The values are compared with experimental results.

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

    DOEpatents

    Savage-Leuchs; Matthias P.

    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.

  3. 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.

  4. 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.

  5. Environmental testing of a diode-laser-pumped Nd:YAG laser and a set of diode-laser-arrays

    NASA Technical Reports Server (NTRS)

    Hemmati, H.; Lesh, J. R.

    1989-01-01

    Results of the environmental test of a compact, rigid and lightweight diode-laser-pumped Nd:YAG laser module are discussed. All optical elements are bonded onto the module using space applicable epoxy, and two 200 mW diode laser arrays for pump sources are used to achieve 126 mW of CW output with about 7 percent electrical-to-optical conversion efficiency. This laser assembly and a set of 20 semiconductor diode laser arrays were environmentally tested by being subjected to vibrational and thermal conditions similar to those experienced during launch of the Space Shuttle, and both performed well. Nevertheless, some damage to the laser front facet in diode lasers was observed. Significant degradation was observed only on lasers which performed poorly in the life test. Improvements in the reliability of the Nd:YAG laser are suggested.

  6. Optics and lasers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Report describes twenty-seven optical concepts developed for holographic viewing, spectral transmission, and film camera technology. Articles include developments in laser-Doppler systems, laser beam deflection controls, X-ray photography, and camera components.

  7. Demonstration of optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber pumped by a picosecond mode-locked ytterbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yang, Si-Gang; Wang, Xiao-Jian; Gou, Dou-Dou; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong

    2014-01-01

    We report the experimental demonstration of the optical parametric gain generation in the 1 μm regime based on a photonic crystal fiber (PCF) with a zero group velocity dispersion (GVD) wavelength of 1062 nm pumped by a homemade tunable picosecond mode-locked ytterbium-doped fiber laser. A broad parametric gain band is obtained by pumping the PCF in the anomalous GVD regime with a relatively low power. Two separated narrow parametric gain bands are observed by pumping the PCF in the normal GVD regime. The peak of the parametric gain profile can be tuned from 927 to 1038 nm and from 1099 to 1228 nm. This widely tunable parametric gain band can be used for a broad band optical parametric amplifier, large span wavelength conversion or a tunable optical parametric oscillator.

  8. 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.

  9. A review of laser-pumped infrared lasers

    NASA Technical Reports Server (NTRS)

    Chen, K. Y.

    1985-01-01

    The lasing mechanisms are reviewed of molecules that have demonstrated laser action in the laboratories with laser emissions in the spectral range from 3 to 35 microns. A list of lasants and laser mechanisms are defined. The pumping sources for these lasers are mainly infrared lasers; however, the case in which excitation of bromine atoms at 2.71 microns by a flashlamp as energy input is also included in the review. A conceptual drawing of lasing mechanisms is shown. Three pumping mechanisms are shown, the first being the direct-pumped system in which the lasant molecule absorbs the infrared radiation from pump laser directly, and it is excited into the upper laser level from the ground state. The second system is the indirect-pumped system where the infrared-pump laser first excites an absorbing molecule which stores its vibrational energy. Through collision this energy is transferred to the lasant molecule, populating the upper laser level. In the third system, i.e., in a Br2-CO2 mixture, a flashlamp replaces the infrared laser as the pump source for the absorbing molecule.

  10. High-peak-power optically-pumped AlGaInAs eye-safe laser with a silicon wafer as an output coupler: comparison between the stack cavity and the separate cavity.

    PubMed

    Wen, C P; Tuan, P H; Liang, H C; Tsou, C H; Su, K W; Huang, K F; Chen, Y F

    2015-11-30

    An intrinsic silicon wafer is exploited as an output coupler to develop a high-peak-power optically-pumped AlGaInAs laser at 1.52 μm. The gain chip is sandwiched with the diamond heat spreader and the silicon wafer to a stack cavity. It is experimentally confirmed that not only the output stability but also the conversion efficiency are considerably enhanced in comparison with the separate cavity in which the silicon wafer is separated from other components. The average output power obtained with the stack cavity was 2.02 W under 11.5 W average pump power, corresponding to an overall optical-to-optical efficiency of 17.5%; the slope efficiency was 18.6%. The laser operated at 100 kHz repetition rate and the pulse peak power was 0.4 kW. PMID:26698707

  11. Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution

    SciTech Connect

    Henn, T.; Kiessling, T. Ossau, W.; Molenkamp, L. W.; Biermann, K.; Santos, P. V.

    2013-12-15

    We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast “white light” supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

  12. Laser diode end-pumped ND:YAG laser. Memorandum report

    SciTech Connect

    Elder, I.F.

    1992-01-01

    100 Hz operation of a Nd:YAG laser longitudinally pumped by a 1 W peak power quasi-cw laser diode was investigated theoretically and experimentally. An optical-to-optical slope efficiency of 33%, indicating a wall-plug efficiency of 7%, was exhibited, but the threshold optical power of 330 mW was high due to poor antireflection coatings on the laser rod giving a round-trip intracavity loss of 3.1 %. The 1.064 micrometer output was observed to be diffraction-limited. The theoretical modelling of the laser's input/ output characteristics agreed well with the experimentally obtained results.

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  16. High 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.

  17. Design of diode laser systems for solid state laser pumping

    NASA Astrophysics Data System (ADS)

    Michel, D.; Luethy, Willy A.; Weber, Heinz P.

    2003-11-01

    In contrast to flashlamps the emission of single stripe laser diodes is highly directional and can be focused rather easily to small spots, which gives access to very high pump intensities. Numerical arrangements are possible for transferring the pump radiation to the solid state laser media. In this paper the most important concepts of diode laser systems for pumping solid state lasers are summarized and described. Thereby the aim is to find the most efficient and powerful method for endpumping a Yb3+-double clad fiber.

  18. 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.

  19. 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.

  20. High-efficiency PPMgLN-based mid-infrared optical parametric oscillator pumped by a MOPA-structured fiber laser with long pulse duration

    NASA Astrophysics Data System (ADS)

    Chen, Tao; Liu, Hao; Huang, Yuxiang; Shu, Rong

    2015-12-01

    We report our recent investigation on the conversion efficiency improvement of a PPMgLN-based single pump pass, singly resonant optical parametric oscillator (OPO) pumped by an acousto-optic Q-switched fiber MOPA. The impacts of the pump pulse duration and signal reflectivity on the pump-to-idler conversion efficiency were studied by numerically solving the coupled wave equations in the first place. The results revealed that longer pulse durations were beneficial to higher conversion efficiencies as long as the signal reflectivity of the OPO cavity was optimized accordingly. Experiments were carried out thereafter utilizing the optimal parameters obtained from the simulation. Idler powers of 4.7 and 3.81 W were achieved at 3.4 and 3.8 μm, respectively, under the highest pump power of 28 W with pump pulse duration of 240 ns. The experimental results were in good agreement with the calculated results. According to our simulation, higher conversion efficiency could be expected when such an OPO was pumped by pulses with even longer duration provided that the signal reflectivity of the output coupler was optimized under that pump condition.

  1. Resonantly pumped high efficiency Ho:YAG laser.

    PubMed

    Shen, Ying-Jie; Yao, Bao-Quan; Duan, Xiao-Ming; Dai, Tong-Yu; Ju, You-Lun; Wang, Yue-Zhu

    2012-11-20

    High-efficient CW and Q-switched Ho:YAG lasers resonantly dual-end-pumped by two diode-pumped Tm:YLF lasers at 1908 nm were investigated. A maximum slope efficiency of 74.8% in CW operation as well as a maximum output power of 58.7 W at 83.2 W incident pump power was achieved, which corresponded to an optical-to-optical conversion efficiency of 70.6%. The maximum pulse energy of 2.94 mJ was achieved, with a 31 ns FWHM pulse width and a peak power of approximately 94.7 kW. PMID:23207298

  2. Vertical-external-cavity surface-emitting 625-nm laser upon optical pumping of an InGaP/AlGaInP nanostructure with a Bragg mirror

    SciTech Connect

    Kozlovskii, Vladimir I; Lavrushin, B M; Skasyrsky, Yan K; Tiberi, M D

    2009-08-31

    Pulsed lasing is obtained in a multilayer quantum-well InGaP/AlGaInP structure in a cavity with an external mirror and a Bragg AlAs/AlGaAs mirror pumped by the 532-nm second harmonic from a diode-pumped Q-switched Nd:YAG laser. Lasing is obtained at the TEM{sub 00} fundamental transverse mode of the cavity at a wavelength of 625 nm. The pulse beam power was 3.1 W and the radiation divergence achieved a diffraction limit of 10-12 mrad for 5-ns pulses with a repetition rate of 6 kHz. (lasers)

  3. 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.

  4. Characteristics of a dye laser amplifier transversely pumped by copper vapor lasers with a two-dimensional calculation model

    SciTech Connect

    Sugiyama, A.; Nakayama, T.; Kato, M.; Maruyama, Y.

    1997-08-01

    A two-dimensional rate equation model, taking into consideration the transverse absorption loss of pump laser power, is proposed to evaluate the characteristics of a dye laser amplifier with a large input laser beam diameter pumped by high average power copper vapor lasers. The calculations are in good agreement with the measurements taken with a Rhodamine 6G dye, and the model can be used for evaluation of the dye concentration at any wavelength. {copyright} 1997 Optical Society of America

  5. Diode-Laser Pumped Far-Infrared Local Oscillator Based on Semiconductor Quantum Wells

    NASA Technical Reports Server (NTRS)

    Kolokolov, K.; Li, J.; Ning, C. Z.; Larrabee, D. C.; Tang, J.; Khodaparast, G.; Kono, J.; Sasa, S.; Inoue, M.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    The contents include: 1) Tetrahertz Field: A Technology Gap; 2) Existing THZ Sources and Shortcomings; 3) Applications of A THZ Laser; 4) Previous Optical Pumped LW Generations; 5) Optically Pumped Sb based Intersubband Generation Whys; 6) InGaAs/InP/AlAsSb QWs; 7) Raman Enhanced Optical Gain; 8) Pump Intensity Dependence of THZ Gain; 9) Pump-Probe Interaction Induced Raman Shift; 10) THZ Laser Gain in InGaAs/InP/AlAsSb QWs; 11) Diode-Laser Pumped Difference Frequency Generation (InGaAs/InP/AlAsSb QWs); 12) 6.1 Angstrom Semiconductor Quantum Wells; 13) InAs/GaSb/AlSb Nanostructures; 14) InAs/AlSb Double QWs: DFG Scheme; 15) Sb-Based Triple QWs: Laser Scheme; and 16) Exciton State Pumped THZ Generation. This paper is presented in viewgraph form.

  6. Modeling polarization reversal in optically pumped rubidium vapors

    NASA Astrophysics Data System (ADS)

    Dreiling, J. M.; Norrgard, E.; Gay, T. J.

    2010-03-01

    Rubidium atoms can be polarized by optical pumping with a resonant circularly polarized laser beam. Using Faraday rotation polarimetry [1], we have observed a flip in the sign of the Rb electron polarization when the wavelength of the pump laser is varied over the D1 absorption spectrum. This could occur if F < (I + J) states with MF = F are predominantly populated at specific pump frequencies resulting in different spin polarizations. We have used a simple rate equation model to estimate the final electron polarization under the assumption that we are able to pump only one F transition at a time. The results of these calculations will be presented. [4pt] [1] H. Batelaan, A.S. Green, B.A. Hitt, and T.J. Gay, Phys. Rev. Lett. 82, 4216 (1999).

  7. 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.

  8. Rubidium Optical Pumping for an Electron Spin Filter

    NASA Astrophysics Data System (ADS)

    Norrgard, Eric

    2010-03-01

    Our group is designing a novel polarized electron source based on spin exchange between an incident beam of electrons and an optically-pumped rubidium vapor target [1,2]. An overview of the spin filter design will be provided. I will then discuss optical pumping of rubidium and techniques for measuring spin polarization. An anomalous Rb polarization reversal detected when varying the wavelength of a pump laser with a spectral width of about 6 percent of the absorption profile of the Rb D2 transition width over the absorption profile will be examined. In the rubidium electron spin filter, viable spin exchange is thought to occur in the immediate vicinity of the exit aperture of the optical pumping region. Therefore, optical techniques for mapping the spatial dependence of a pumped Rb sample will be discussed, and measurements of Rb polarization throughout the optically-pump region will be presented.[4pt] [1] H. Batelaan et al., Phys. Rev. Lett., 82, 4216 (1999).[0pt] [2] M.A. Rosenberry, J.P. Reyes, D. Tupa, T.J. Gay Phys. Rev. A 75, 023401 (2007).

  9. Coupled optical resonance laser locking

    NASA Astrophysics Data System (ADS)

    Burd, S. C.; du Toit, P. J. W.; Uys, H.

    2014-10-01

    We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to the same spectroscopic sample, by monitoring only the absorption of the UV laser. For trapping and cooling Yb$^{+}$ ions, a frequency stabilized laser is required at 369.95nm to drive the $^{2}S_{1/2}$ $ \\rightarrow $ $ ^{2}P_{1/2}$ cooling transition. Since the cycle is not closed, a 935.18nm laser is needed to drive the $^{2}D_{3/2}$ $\\rightarrow$ $^{3}D_{[3/2]1/2}$ transition which is followed by rapid decay to the $^{2}S_{1/2}$ state. Our 369nm laser is locked to Yb$^{+}$ ions generated in a hollow cathode discharge lamp using saturated absorption spectroscopy. Without pumping, the metastable $^{2}D_{3/2}$ level is only sparsely populated and direct absorption of 935nm light is difficult to detect. A resonant 369nm laser is able to significantly populate the $^{2}D_{3/2}$ state due to the coupling between the levels. Fast re-pumping to the $^{2}S_{1/2}$ state, by 935nm light, can be detected by observing the change in absorption of the 369nm laser using lock-in detection of the photodiode signal. In this way simultaneous locking of two optical frequencies in very different spectral regimes is accomplished. A rate equation model gives good qualitative agreement with the experimental results. This technique offers improved laser frequency stabilization compared to lasers locked individually to the sample and should be readily applicable to similar ion systems.

  10. Segment side-pumped Q-switched Nd:YAG laser.

    PubMed

    Wang, Wei; Fu, Chen; Hu, Zhenyue; Zhao, Qin; Gong, Mali

    2012-04-10

    In the design of conduction-cooled lasers, a side-pumped configuration is an attempt to solve the space conflict between pump and heat removal. The pump radiation always competes with the heat removal and mechanical support device for the lateral surface of a laser rod. This space conflict can be addressed by a segment side-pumped configuration in which circular laser diode arrays and heat-conducting rod holders alternate periodically along the length of the laser rod. This scheme permitted 11 Hz operation of a 190 mJ Q-switched laser at the wavelength of 1064 nm without the use of liquid cooling for both the laser rod and laser diode arrays and the corresponding optical-optical conversion efficiency of 23.1%. Thus, it has great potential to be used in compact and miniature laser systems. PMID:22505168

  11. Coherent communication link using diode-pumped lasers

    NASA Technical Reports Server (NTRS)

    Kane, Thomas J.; Wallace, Richard W.

    1989-01-01

    Work toward developing a diffraction limited, single frequency, modulated transmitter suitable for coherent optical communication or direct detection communication is discussed. Diode pumped, monolithic Nd:YAG nonplanar ring oscillators were used as the carrier beam. An external modulation technique which can handle high optical powers, has moderate modulation voltage, and which can reach modulation rates of 1 GHz was invented. Semiconductor laser pumped solid-state lasers which have high output power (0.5 Watt) and which oscillate at a single frequency, in a diffraction limited beam, at the wavelength of 1.06 microns were built. A technique for phase modulating the laser output by 180 degrees with a 40-volt peak to peak driving voltage is demonstrated. This technique can be adapted for amplitude modulation of 100 percent with the same voltage. This technique makes use of a resonant bulk modulator, so it does not have the power handling limitations of guided wave modulators.

  12. 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.

  13. 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.

  14. 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.

  15. Resonantly photo-pumped nickel-like erbium X-ray laser

    DOEpatents

    Nilsen, Joseph

    1990-01-01

    A resonantly photo-pumped X-ray laser (10) that enhances the gain of seve laser lines that also lase because of collisional excitations and recombination processes, is described. The laser comprises an aluminum (12) and erbium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like erbium ions (34) are resonantly photo-pumped by line emission from hydrogen-like aluminum ions (32).

  16. Reactor-pumped laser experimental results

    SciTech Connect

    Hebner, G.A.; Hays, G.N.

    1994-12-31

    Reactor pumped lasers have the potential to be scaled to multi-megawatt power levels with long run times. In proposed designs, the laser will be capable of output powers of several megawatts of power for run times of several hours. Such a laser would have many diverse applications such as material processing, space debris removal and power beaming to geosynchronous satellites or the moon. However, before such systems can be designed, fundamental laser parameters such as small signal gain, saturation intensity and efficiency must be determined over a wide operational parameter space. The authors have recently measured fundamental laser parameters for a selection of nuclear pumped visible and near IR laser transitions in atomic neon, argon and xenon. An overview of the results of this investigation will be presented.

  17. Pump wavelength tuning of optical parametric oscillations and frequency mixing in KTiOAsO4

    NASA Technical Reports Server (NTRS)

    Jani, Mahendra G.; Murray, James T.; Petrin, Roger R.; Powell, Richard C.; Loiacono, D. N.; Loiacono, G. M.

    1992-01-01

    The properties of alexandrite laser-pumped optical parametric oscillators are reported for potassium titanyl arsenate. Near-infrared tuning curves and slope efficiencies were measured as functions of pump wavelength and pump power. In addition, sum frequency mixing of red and infrared wavelengths to produce green emission is also reported.

  18. Efficient single-pass resonantly-pumped Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Elder, Ian; Kendall, Timothy

    2012-09-01

    A simple scheme for efficient generation of two micron laser radiation is reported. Using a thulium fibre laser to pump a Q-switched Ho:YAG laser 31.7 W of average output power is achieved with an M2 of 1.5 (an optical-to-optical conversion efficiency of 67% in terms of absorbed pump power) at a wavelength of 2.1 μm. A single-pass pump geometry is used, eliminating the risk of feedback of unabsorbed light into the fibre laser.

  19. Narrow spectral width laser diode for metastable argon atoms pumping

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Li, Bin; Wang, Xinbing; Zuo, Duluo

    2016-03-01

    Diode laser pump source with narrow emitting spectrum for optically pumped metastable rare gas laser (OPRGL) of argon was achieved by employing a complex external cavity coupled with volume Bragg grating (VBG). A commercially available c-mount laser diode with rated power of 6 W was used and studied in both the free running mode and VBG external cavity. The maximum output power of 3.9 W with FWHM less than 25 pm and peak wavelength locked around 811.53 nm was obtained from the VBG external cavity laser diode. Precise control of VBG temperature enabled fine tuning of the emission wavelength over a range of 450 pm. Future researches on OPRGL of argon will benefit from it.

  20. Degradation studies and pump optimization of optically pumped red-emitting AlGaInP-VECSELs

    NASA Astrophysics Data System (ADS)

    Kahle, Hermann; Mateo, Cherry M. N.; Jäger, Maren; Weinspach, Karoline; Baumgärtner, Stefan; Brauch, Uwe; Bek, Roman; Schwarzbäck, Thomas; Jetter, Michael; Graf, Thomas; Michler, Peter

    2015-03-01

    Optically pumped semiconductor (OPS) vertical external-cavity surface-emitting lasers (VECSELs) are an important category of power scalable lasers with a wide range of applications in biophotonics, medicine technologies, spectroscopy, projector technologies and lithography. The open laser resonator allows to implement frequency selective and converting intra-cavity elements. The possibility of bandgap engineering, laser emission in the fundamental Gaussian mode and the technical simplicity leads to ongoing growth of the area of applications for these tunable laser sources. We present degradation studies of metal-organic vapor-phase epitaxy (MOVPE) grown, optically pumped, red-emitting AlGaInP-VECSELs with quantum wells (QWs) as active layers. Laser performance in continuous operation, pumped with a 532nm Nd:YAG laser and recorded over several hours, will be shown. Surface investigations of the gain structure via large-area photoluminescence maps show the possible consequences of optical pumping. A comparison of barrier-pumped performance data with the data of an in-well pumped VECSEL device is shown.

  1. 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.

  2. Ray tracing in nuclear-pumped flowing gas lasers

    SciTech Connect

    Mat'ev, V Yu

    2003-06-30

    The ray tracing in the resonators of a nuclear-pumped flowing gas lasers is considered. The refractive index profile of the medium in a direction perpendicular to the optical axis in such lasers can be considered parabolic, but the steepness of the parabola is quite nonuniform along the ray trace, and the resonator stability condition (the absolute value of the ray matrix trace for a single trip of the ray in the resonator is smaller than two) is not sufficient to confine the ray within the resonator after a large number of trips. (lasers)

  3. 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.

  4. Diode-Pumped Mode-Locked LiSAF Laser

    SciTech Connect

    1996-02-01

    Under this contract we have developed Cr{sup 3+}:LiSrAlF{sub 6} (Cr:LiSAF, LiSAF) mode-locked lasers suitable for generation of polarized electrons for CEBAF. As 670 nm is an excellent wavelength for optical pumping of Cr:LiSAF, we have used a LIGHTWAVE developed 670 nm diode pump module that combines the output of ten diode lasers and yields approximately 2 Watts of optical power. By the use of a diffraction limited pump beam however, it is possible to maintain a small mode size through the length of the crystal and hence extract more power from Cr:LiSAF laser. For this purpose we have developed a 1 Watt, red 660nm laser (LIGHTWAVE model 240R) which serves as an ideal pump for Cr:LiSAF and is a potential replacement of costly and less robust krypton laser. This new system is to compliment LIGHTWAVE Series 240, and is currently being considered for commercialization. Partially developed under this contract is LIGHTWAVEs product model 240 which has already been in our production lines for a few months and is commercially available. This laser produces 2 Watts of output at 532 nm using some of the same technology developed for production of the 660nm red system. It is a potential replacement for argon ion lasers and has better current and cooling requirements and is an excellent pump source for Ti:Al{sub 2}O{sub 3}. Also, as a direct result of this contract we now have the capability of commercially developing a mode-locked 100MHz Cr:LiSAF system. Such a laser could be added to our 100 MHz LIGHTWAVE Series 131. The Series 131 lasers provide pico second pulses and were originally developed under another DOE SBIR. Both models of LIGHTWAVE Series 240 lasers, the fiber coupled pump module and the 100MHz LiSAF laser of Series 131 have been partially developed under this contract, and are commercially competitive products.

  5. Enhanced efficiency of AlGaInP disk laser by in-well pumping.

    PubMed

    Mateo, C M N; Brauch, U; Schwarzbäck, T; Kahle, H; Jetter, M; Abdou Ahmed, M; Michler, P; Graf, T

    2015-02-01

    The performance of a 665-nm GaInP disk laser operated continuous-wave at 15°C both in-well-pumped at 640 nm and barrier pumped at 532 nm is reported. The efficiency with respect to the absorbed power was enhanced by 3.5 times when using a 640-nm pump instead of a 532-nm pump. In-well pumping which is based on the absorption of the pump photons within the quantum-well heterostructures of the gain region instead of short-wavelength absorption in the barrier and spacer regions reduces the quantum defect between pump and laser photon and hence the heat generation. A slope efficiency of 60% with respect to the absorbed pump power was obtained by in-well pumping at 15°C. Continuous-wave laser operation was further demonstrated at heat sink temperatures of up to 55°C. Both the measurement of photoluminescence and COMSOL simulation show that the overall heat load in the in-well pumped laser is smaller than in the barrier-pumped laser. These results demonstrate the potential of optical in-well pumping for the operation of red AlGaInP disk lasers if combined with means for efficient pump-light absorption. PMID:25836115

  6. Supersonic diode pumped alkali lasers: Computational fluid dynamics modeling

    NASA Astrophysics Data System (ADS)

    Rosenwaks, Salman; Yacoby, Eyal; Waichman, Karol; Sadot, Oren; Barmashenko, Boris D.

    2015-10-01

    We report on recent progress on our three-dimensional computational fluid dynamics (3D CFD) modeling of supersonic diode pumped alkali lasers (DPALs), taking into account fluid dynamics and kinetic processes in the lasing medium. For a supersonic Cs DPAL with laser section geometry and resonator parameters similar to those of the 1-kW flowing-gas subsonic Cs DPAL [A.V. Bogachev et al., Quantum Electron. 42, 95 (2012)] the maximum achievable output power, ~ 7 kW, is 25% higher than that achievable in the subsonic case. Comparison between semi-analytical and 3D CFD models for Cs shows that the latter predicts much higher maximum achievable output power than the former. Optimization of the laser parameters using 3D CFD modeling shows that very high power and optical-to-optical efficiency, 35 kW and 82%, respectively, can be achieved in a Cs supersonic device pumped by a collimated cylindrical (0.5 cm diameter) beam. Application of end- or transverse-pumping by collimated rectangular (large cross section ~ 2 - 4 cm2) beam makes it possible to obtain even higher output power, > 250 kW, for ~ 350 kW pumping power. The main processes limiting the power of Cs supersonic DPAL are saturation of the D2 transition and large ~ 40% losses of alkali atoms due to ionization, whereas the influence of gas heating is negligibly small. For supersonic K DPAL both gas heating and ionization effects are shown to be unimportant and the maximum achievable power, ~ 40 kW and 350 kW, for pumping by ~ 100 kW cylindrical and ~ 700 kW rectangular beam, respectively, are higher than those achievable in the Cs supersonic laser. The power achieved in the supersonic K DPAL is two times higher than for the subsonic version with the same resonator and K density at the gas inlet, the maximum optical-to-optical efficiency being 82%.

  7. Laser rods with undoped, flanged end-caps for end-pumped laser applications

    DOEpatents

    Meissner, Helmuth E.; Beach, Raymond J.; Bibeau, Camille; Sutton, Steven B.; Mitchell, Scott; Bass, Isaac; Honea, Eric

    1999-01-01

    A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focussed by a lens duct and passed through at least one flanged end-cap into the laser rod.

  8. Fiber optic laser rod

    DOEpatents

    Erickson, G.F.

    1988-04-13

    A laser rod is formed from a plurality of optical fibers, each forming an individual laser. Synchronization of the individual fiber lasers is obtained by evanescent wave coupling between adjacent optical fiber cores. The fiber cores are dye-doped and spaced at a distance appropriate for evanescent wave coupling at the wavelength of the selected dye. An interstitial material having an index of refraction lower than that of the fiber core provides the optical isolation for effective lasing action while maintaining the cores at the appropriate coupling distance. 2 figs.

  9. LED pumped polymer laser sensor for explosives

    PubMed Central

    Wang, Yue; Morawska, Paulina O; Kanibolotsky, Alexander L; Skabara, Peter J; Turnbull, Graham A; Samuel, Ifor D W

    2013-01-01

    A very compact explosive vapor sensor is demonstrated based on a distributed feedback polymer laser pumped by a commercial InGaN light-emitting diode. The laser shows a two-stage turn on of the laser emission, for pulsed drive currents above 15.7 A. The ‘double-threshold’ phenomenon is attributed to the slow rise of the ∼30 ns duration LED pump pulses. The laser emits a 533 nm pulsed output beam of ∼10 ns duration perpendicular to the polymer film. When exposed to nitroaromatic model explosive vapors at ∼8 ppb concentration, the laser shows a 46% change in the surface-emitted output under optimized LED excitation. PMID:25821526

  10. Progress in discharge-pumped excimer lasers

    NASA Astrophysics Data System (ADS)

    Pike, Charles T.

    1993-04-01

    This paper describes recent results achieved in the development of discharge pumped excimer lasers at the Textron Defense Systems organization (formerly the Avco Research Laboratory). Included is a description of a KrF laser with more than one Joule output at 2.4% efficiency, a 200 mJ XeCl laser operating with a 500 nsec wide pulse, and a several Joule, discharge pumped, KrCl laser operating at 222 nm. All of these devices are switched using thyratrons and are therefore capable of repetitive performance. The KrF and XeCl experiments were conducted with the same laser device operating with a conventional capacitor transfer excitation circuit for the KrF experiments but modified to operate with a pulser-sustainer discharge circuit using magnetic switching for the XeCl tests. The KrCl device is a 40 liter volume system built by Northrop and also operates with a magnetically switched discharge.

  11. 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.

  12. 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.

  13. Efficient 750-nm LED-pumped Nd:YAG laser.

    PubMed

    Huang, Kuan-Yan; Su, Cheng-Kuo; Lin, Meng-Wei; Chiu, Yu-Chung; Huang, Yen-Chieh

    2016-05-30

    We report an Nd:YAG laser pumped by light emission diodes (LEDs) at 750 nm. With 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 37.5 μJ pulse energy at 1064 nm with M2 = 1.1 when pumped by 2.73-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser are 1.36, and 9%, respectively. With 1 and 5% output couplings from a Z-cavity containing the same laser crystal, the lasers generated 346 and 288 μJ pulse energy with an optical efficiency of 3.4 and 2.8% and slope efficiency of 6.6 and 14%, respectively, for the same 1-ms pump pulse repeating at a 10 Hz rate. At the highest output from the Z-cavity, the measured M2 for the beam is 3.6. PMID:27410125

  14. Efficient femtosecond Yb:YAG laser pumped by a single-mode laser diode

    NASA Astrophysics Data System (ADS)

    Agnesi, Antonio; Greborio, Alessandro; Pirzio, Federico; Reali, Giancarlo

    2011-08-01

    Single-mode diodes enable a particularly simple, compact and effective pumping of solid-state laser devices for many specialized applications. We investigated a single-mode, 300-mW laser diode for pumping at 935 nm a Yb:YAG laser passively mode-locked by a semiconductor saturable absorber. Relatively short pulse generation (156 fs), tunable across 1033-1059 nm has been demonstrated. An optical-to-optical efficiency of about 28% has been obtained with 320 fs long pulses. Therefore, contrarily to what previously believed, compact diode-pumped ultrafast Yb:YAG oscillators can reliably and efficiently deliver pulses in the range of ≈ 100-200 fs with few tens of mW, which are very appealing for bio-diagnostics and amplifier seeding applications.

  15. 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.

  16. A kilowatt level diode-side-pumped QCW Nd:YAG ceramic laser

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    We demonstrate a kilowatt level Quasi-continuous-wave (QCW) diode-side-pumped Nd:YAG ceramic laser at 1064 nm. The laser system adopts a master oscillator power amplifier scheme (MOPA). The master oscillator contains two diode-pumped laser modules. Under the pump power of 2000 W, an output power of 686 W was obtained. After amplified by an identical ceramic laser module, a maximum output power of 1020 W was obtained under a total incident pump power of 3433 W, corresponding to an optical-optical conversion efficiency of 29.7%. At the maximal output power, the repetition frequency was measured to be 1 kHz and the pulse width was 114 μs. To the best of our knowledge, this is the first time to realize QCW side-pumped Nd:YAG ceramic laser system with output power above 1 kW.

  17. Broad-Area Laser Diode With Fiber-Optic Injection

    NASA Technical Reports Server (NTRS)

    Hazel, Geoffrey; Mead, Patricia; Davis, Christopher; Cornwell, Donald

    1992-01-01

    Fiber-optic injection-locked broad-area laser diode features single-mode output via fiber-optic injection and serves as compact, rugged, high-power near-infrared source. Useful in free-space and fiber-optic communication links, as communication-receiver preamplifier, and pump source for solid-state lasers.

  18. Laser Wakefield acceleration with high relativistic pumps

    NASA Astrophysics Data System (ADS)

    Katsouleas, T.; Mori, W. B.; Darrow, C. B.

    1989-10-01

    Preliminary scaling laws are found for the laser wakefield accelerator in the very non-linear regime where the normalized laser pump strengh Voscc=eE0/mω0c≳1. Two important non-linear effects are an increase in the wake phase velocity (and hence the particle dephasing length) and an increase in the laser pulse length for optimal wake excitation. Application of the results to the proposed Livermore High-Brightness Lasers (HBL) is discussed here and in the accompanying paper by C. B. Darrow, et al. A preliminary 1-D PIC simulation is presented.

  19. Thulium fiber laser-pumped mid-IR OPO

    NASA Astrophysics Data System (ADS)

    Creeden, Daniel; Jiang, Min; Budni, Peter A.; Ketteridge, Peter A.; Setzler, Scott D.; Young, York E.; McCarthy, John C.; Schunemann, Peter G.; Pollak, Thomas M.; Tayebati, Parviz; Chicklis, Evan P.

    2008-04-01

    Fiber lasers are advancing rapidly due to their ability to generate stable, efficient, and diffraction-limited beams with significant peak and average powers. This is of particular interest as fibers provide an ideal pump source for driving parametric processes. Most nonlinear optical crystals which provide phase-matching to the mid-IR at commercially available fiber pump wavelengths suffer from high absorption above 4μm, resulting in low conversion efficiencies in the 4-5μm spectral region. The nonlinear optical crystals which combine low absorption in this same spectral region with high nonlinear gain require pumping at longer wavelengths (typically >1.9μm). In this paper, we report a novel mid-IR OPO pumped by a pulsed thulium-doped fiber laser operating at 2-microns. The eyesafe thulium-fiber pump laser generates >3W of average power at >30kHz repetition rate with 15-30ns pulses in a near diffraction-limited beam. The ZnGeP II (ZGP) OPO produces tunable mid-IR output power in the 3.4-3.99μm (signal) and the 4.0-4.7μm (idler) spectral regions in both singly resonant (SRO) and doubly resonant (DRO) formats. The highest mid-IR output power achieved from this system was 800mW with 20% conversion efficiency at 40kHz. In a separate experiment, the 3W of 2-micron light was further amplified to the 20W level. This amplified output was also used to pump a ZGP OPO, resulting in 2W of output power in the mid-IR. To our knowledge, these are the first demonstrations of a fiber-pumped ZGP OPO.

  20. 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.

  1. 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.

  2. 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.

  3. Optimized spatial overlap in optical pump-X-ray probe experiments with high repetition rate using laser-induced surface distortions.

    PubMed

    Reinhardt, Matthias; Koc, Azize; Leitenberger, Wolfram; Gaal, Peter; Bargheer, Matias

    2016-03-01

    Ultrafast X-ray diffraction experiments require careful adjustment of the spatial overlap between the optical excitation and the X-ray probe pulse. This is especially challenging at high laser repetition rates. Sample distortions caused by the large heat load on the sample and the relatively low optical energy per pulse lead to only tiny signal changes. In consequence, this results in small footprints of the optical excitation on the sample, which turns the adjustment of the overlap difficult. Here a method for reliable overlap adjustment based on reciprocal space mapping of a laser excited thin film is presented. PMID:26917135

  4. Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers.

    PubMed

    Theeg, Thomas; Sayinc, Hakan; Neumann, Jörg; Overmeyer, Ludger; Kracht, Dietmar

    2012-12-17

    We developed an all-fiber component with a signal feedthrough capable of combining up to 6 fiber-coupled multi-mode pump sources to a maximum pump power of 400 W at efficiencies in the range of 89 to 95%, providing the possibility of transmitting a high power signal in forward and in reverse direction. Hence, the fiber combiner can be implemented in almost any fiber laser or amplifier architecture. The complete optical design of the combiner was developed based on ray tracing simulations and confirmed by experimental results. PMID:23263048

  5. Double-pass pumped extracavity optical parametric oscillator with passive optical feedback suppression

    NASA Astrophysics Data System (ADS)

    Alyamani, A.; Algahtani, M.; Rusak, A. A.; Orlovich, V. A.; Dashkevich, V. I.; El-Desouki, M.

    2016-04-01

    We demonstrate a simple way of building a compact eye-safe laser source based on a double-pass pumped extracavity optical parametric oscillator (EOPO) without an optical Faraday isolator. A Nd:KGW pump laser (PL) and the KTP EOPO located close to the PL are designed with stable cavities, while the 100% end system mirrors form an unstable cavity with sufficiently high threshold at 1067 nm. At the 6.6 J pump of the Nd:KGW laser, the EOPO output energy obtained at 1577 nm is 14.7 mJ, corresponding to the conversion efficiency of 33% with respect to the fundamental. The pulse width is 7 ns and the output beam divergence is 3 times diffraction limit.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  7. Infrared spectrum involving forbidden transitions & coriolis interaction and identification of optically pumped far infrared laser lines in asymmetrically mono-deuterated methanol (Methanol-D1)

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Indra

    2016-05-01

    In this paper new type of ΔK = 2 and 0 transitions have been identified in the Fourier Transform spectrum of Methanol-D1 (CH2DOH). These transitions are normally forbidden but a "Coriolis" type interaction with nearby states is believed to be contributing sufficient transition strength through intensity borrowing effect. This is the first time such forbidden transitions are reported to be identified in the excited states, in this molecule. The present conjecture is supported by observation of a many strong allowed transitions to upper terminating levels which are seen to be highly perturbed. This conclusion has been reached by comparing calculated energy levels using known molecular parameters (Pearson et al., 2012; Coudert et al., 2014; El Hilali et al., 2011; Quade et al., 1998; Richard Quade, 1998, 1999; Mukhopadhyay, 1997) and the actually observed FIR lines. The upper levels are seen to be upshifted from expected position. A closer look at the calculated energy values seems to indicate a possible interaction between the above states and other proximate torsional-rotational states could occur. The possible candidates for the interacting level manifolds are narrowed down through the presence of the forbidden transition. We also take the opportunity to propose alternate rotational quantum numbers for some of the assignments recently reported in the literature (El Hilali et al., 2011). Some ambiguities are pointed out on the data and the reported analysis. There remain too many such irregularities and we propose to gather a large body assigned transitions in a future catalog. Assignments and relevant comments on optically pumped FIR laser radiation are also made.

  8. Flashlamp-pumped iodine monobromide laser characteristics

    NASA Technical Reports Server (NTRS)

    Zapata, L. E.; De Young, R. J.

    1983-01-01

    The operating characteristics of a flashlamp-pumped IBr laser were investigated to evaluate its suitability for solar-pumped laser applications. A peak power of 350 W/sq cm at 2.7 microns was achieved at 12-torr IBr pressure. At 500-J flashlamp energy, the IBr output saturated; a gain of 0.17% per cm was measured for IBr. Neon was found to be effective for enhancing the recombination of the photodissociation products. With neon as a buffer gas, the laser pulse length was extended to 53 microsec. The termination of the laser pulse, within the flashlamp pulse, is thought to be due to the temperature rise in the gas. Increasing the IBr initial temperature decreased the lasing output. At 300 C, output dropped to approximately one-half the room temperature value. The dominant quencher is thought to be atomic iodine. IBr was found to couple better to the flashlamp energy than C3F7I.

  9. Parameters of a dye laser with transverse pumping

    SciTech Connect

    Burakov, V.S.; Samson, A.M.; Zhukovskii, V.V.; Isaevich, A.V.

    1987-12-01

    The authors describe a new method for determining the excitation and output parameters of dye laser media under conditions of transverse optical pumping by laser radiation. The dye is modeled as a medium with two electron-vibrational levels. The method is based on the variation of the value of the distance on the mirror reflection coefficients of the resonator and on estimates of inactive or parasitic losses, the probability of exciting active dye molecules with the radiation incident on the front face of the cell, and the unsaturated gain coefficient of that output frequency. Experimental data are then derived for these conditions for a rhodamine 4C solution in ethanol. Pumping was done using a neodymium laser.

  10. Electrically pumped edge-emitting photonic bandgap semiconductor laser

    DOEpatents

    Lin, Shawn-Yu; Zubrzycki, Walter J.

    2004-01-06

    A highly efficient, electrically pumped edge-emitting semiconductor laser based on a one- or two-dimensional photonic bandgap (PBG) structure is described. The laser optical cavity is formed using a pair of PBG mirrors operating in the photonic band gap regime. Transverse confinement is achieved by surrounding an active semiconductor layer of high refractive index with lower-index cladding layers. The cladding layers can be electrically insulating in the passive PBG mirror and waveguide regions with a small conducting aperture for efficient channeling of the injection pump current into the active region. The active layer can comprise a quantum well structure. The quantum well structure can be relaxed in the passive regions to provide efficient extraction of laser light from the active region.

  11. Resonantly pumped Tm-doped fiber laser with >90% slope efficiency.

    PubMed

    Creeden, Daniel; Johnson, Benjamin R; Setzler, Scott D; Chicklis, Evan P

    2014-02-01

    We have demonstrated what we believe is the highest slope efficiency reported for a Tm-doped fiber laser operating in the 2-micron spectral region. Using a 1908 nm Tm-doped fiber laser as an in-band pump source, we generated 1.43 W of output power at 2005 nm with 81.25% optical efficiency and 90.2% slope efficiency, with respect to launched pump power. This resonant-pumping approach allowed us to examine the bleaching effects in Tm-doped fiber under resonant pumping. We also analytically show that this pumping method can scale to high power levels while maintaining high efficiency. PMID:24487842

  12. 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.

  13. 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.

  14. Wavelength stabilizer based on dual fiber Bragg gratings for 980nm Mini-uncooled pump laser

    NASA Astrophysics Data System (ADS)

    Hu, Shuangshuang; Li, Yi; Jiang, Qunjie; Wu, Bin; Yu, Xiaojing; Wang, Haifang

    2008-12-01

    High power 980nm pump lasers are the key components in optical fiber amplifier. Wavelength stability for 980nm Miniuncooled pump laser is required to maintain the amplifier's efficiency throughout its lifetime. In this paper, a new type of wavelength stabilizer for uncooled pump laser which utilizes two fiber Bragg gratings (FBGs) matched in wavelength, bandwidth, and reflectivity is presented. The characteristics of transmissivity and reflectivity for the dual FBGs stabilized 980nm pump laser are theoretically modeled and experimentally studied. The results show that the output spectral characteristics of the uncooled pump laser with the dual FBGs have been greatly improved. The laser module can work steadily over a wide temperature range from 0°C to 70°C, with 0.2nm wavelength shift, along with more than 45dB side mode suppression ratio, and less than 1.57nm spectral bandwidth.

  15. Double-beam, mode-controlling diode side-pumped Nd:YLF laser with near 60% efficiency

    NASA Astrophysics Data System (ADS)

    Deana, Alessandro M.; Wetter, Niklaus U.

    2015-02-01

    The double-beam, mode-controlling technique (DBMC) is a compact side-pumped laser design, very advantageous for systems based on active media with intermediate absorption cross section, such as Nd:YLiF4 (Nd:YLF). Recently, a record optical efficiency of 53.6% and 63.5% slope efficiency has been achieved for a Nd:YLF laser emitting at 1053 nm with diffraction limited beam quality. In this work we review our results using the DBMC design and present the latest achievements exploiting new ways to push the limit of this technique to higher pump powers. By narrowing down the laser emission bandwidth of the pump diode bar using a volume Bragg gratings (VBG) we increased the effective absorption cross section in the Nd:YLF crystal, improving the spatial overlap between pump and laser beam. With this setup the laser delivers 68 W peak fundamental mode output power at 115 W of QCW absorbed peak power, resulting near 60% of optical-to-optical efficiency which is, to the best of our knowledge, the highest efficiency ever reported for a Nd:YLF laser, considering even longitudinal pump schemes. The results reported here highlight the remarkable advantages of the side pumped DBMC laser scheme versus longitudinal pumped laser set-ups, showing that the efficiency of the side-pumped DBMC laser is not suppressed by its spatially weaker overlap between pump and laser mode and preserving single mode laser operation, even at high pump powers.

  16. Yb:YAG enhanced Cr,Yb:YAG self-Q-switched microchip laser under QCW laser-diode pumping

    NASA Astrophysics Data System (ADS)

    Wang, Guangyu; Chen, Dimeng; Cheng, Ying; Dong, Jun

    2015-05-01

    Enhanced Cr,Yb:YAG self-Q-switched microchip lasers by bonding Yb:YAG crystal have been studied under quasi-continuous-wave (QCW) laser-diode pumping for the first time to our best knowledge. The effects of the pump pulse duration and pump power of the QCW laser-diode on the performance of Yb:YAG/Cr,Yb:YAG microchip lasers have been investigated. The optical efficiency, pulse energy and peak power of the Yb:YAG/Cr,Yb:YAG self-Q-switched laser increase with the pump pulse duration and pump power, and tend to be constant when the pump pulse duration is longer than 1 ms, which is comparable to the fluorescence lifetime of Yb:YAG crystal. Output energy of over 11.7 mJ was obtained at input pump energy of 48.2 mJ; corresponding optical-to-optical efficiency of 24.3% was obtained. Laser pulses with pulse energy of 31 μJ and peak power of 13.3 kW were obtained. The multi-longitudinal modes oscillation around 1030 nm was dominant within the available input pump energy.

  17. Diode-pumped self-frequency-doubled neodymium yttrium aluminum borate (NYAB) laser

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid

    1992-01-01

    Over 50 mW of the fundamental-mode 531-nm laser output was obtained with approximately 4 percent optical-to-optical conversion efficiency from a self-frequency-doubling NYAB crystal when pumped with two 1-W diode lasers. The prospect of higher conversion efficiency is discussed.

  18. 946 nm Diode Pumped Laser Produces 100mJ

    NASA Technical Reports Server (NTRS)

    Axenson, Theresa J.; Barnes, Norman P.; Reichle, Donald J., Jr.

    2000-01-01

    An innovative approach to obtaining high energy at 946 nm has yielded 101 mJ of laser energy with an optical-to-optical slope efficiency of 24.5%. A single gain module resonator was evaluated, yielding a maximum output energy of 50 mJ. In order to obtain higher energy a second gain module was incorporated into the resonator. This innovative approach produced un-surprised output energy of 101 mJ. This is of utmost importance since it demonstrates that the laser output energy scales directly with the number of gain modules. Therefore, higher energies can be realized by simply increasing the number of gain modules within the laser oscillator. The laser resonator incorporates two gain modules into a folded "M-shaped" resonator, allowing a quadruple pass gain within each rod. Each of these modules consists of a diode (stack of 30 microlensed 100 Watt diode array bars, each with its own fiber lens) end-pumping a Nd:YAG laser rod. The diode output is collected by a lens duct, which focuses the energy into a 2 mm diameter flat to flat octagonal pump area of the laser crystal. Special coatings have been developed to mitigate energy storage problems, including parasitic lasing and amplified spontaneous emission (ASE), and encourage the resonator to operate at the lower gain transition at 946 nm.

  19. Magnetic Resonance Reversals in Optically Pumped Alkali-Metal Vapor

    NASA Astrophysics Data System (ADS)

    Gong, Fei; Jau, Yuan-Yu; Happer, William

    2007-06-01

    We report an unusual new phenomenon, peculiar sign reversals of the ground-state magnetic resonances and of the ``zero-dip" resonance (Zeeman resonance at zero field) of optically-pumped, alkali-metal vapors. These anomalies occur when a ``weak" circular polarized D1 laser light is tuned to pump atoms predominantly from the lower ground-state hyperfine multiplet. One can understand the signal reversals in simple, semi-quantitative way with reference to this distribution. uantitative computer simulations are in excellent greement with observations.

  20. Magnetic resonance reversals in optically pumped alkali-metal vapor

    NASA Astrophysics Data System (ADS)

    Gong, F.; Jau, Y.-Y.; Happer, W.

    2007-05-01

    We report an unusual phenomenon, peculiar sign reversals of the ground-state magnetic resonances and of the zero-dip resonance (Zeeman resonance at zero field) of optically pumped, alkali-metal vapors. These anomalies occur when a weak circularly polarized D1 laser light is tuned to pump atoms predominantly from the lower ground-state hyperfine multiplet. One can understand the signal reversals in a simple, semiquantitative way with reference to the spin-temperature distribution. Quantitative computer simulations are in excellent agreement with observations.

  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. A Kinetic Plasma-Pumped Rare Gas Laser

    NASA Astrophysics Data System (ADS)

    Parsey, Guy; Güçlü, Yaman; Verboncoeur, John; Christlieb, Andrew

    2015-09-01

    Extending from diode-pumped alkali vapor lasers (DPAL), Han and Heaven have shown that rare gas metastable states, np5 (n + 1) s[ 3 / 2 ] 2 , can operate as the base of a three-level laser with excition of the (n + 1) s --> (n + 1) p transitions. Though both the rare gas lasers (RGL) and DPALs can be excited with incoherent optical pumping, RGLs do not suffer from the highly reactive behavior of alkali metals. Since metastable populations are maintained via electric discharge, we propose using a tuned electron energy distribution function (EEDF) to modify RGL efficiencies and drive the population inversion. The EEDF is maintained by the discharge along with the introduction of electron sources. Using our kinetic global modeling framework (KGMf) and three gas systems (helium buffered argon and krypton along with pure argon), we first validate the intracavity intensity laser model and then generate gain and energy efficiency baselines for each system. Parameter scanning methods are then used to find optimized EEDFs and system parameters for metastable production, generation of a lasing population inversion, and increasing RGL operation efficiencies. Finally, we determine if an RGL can operate without optical pumping. Supported by AFOSR and a MSU Strategic Partnership Grant

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

    NASA Astrophysics Data System (ADS)

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

    2008-01-01

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

  4. Visible superfluorescence from optically pumped europium atoms

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, S.; Nakhate, S. G.

    2009-10-01

    We have observed superfluorescence (SF) on five atomic transitions at visible wavelengths 633.58, 635.00, 640.09, 640.61 and 736.22 nm in Doppler broadened gas of europium (Eu) atom. The nanosecond SF pulses were observed by longitudinally pumping Eu vapor column with a pulsed dye laser to upper states 4f65d6s2, 8D7/2at 346.79 nm and 4f75d6p, 10F5/2at 348.73 nm from the ground state 4f76s2, 8S7/2. High optical conversion efficiency ≈10% was measured for these SF transitions. Our experiment deals with the large sample multilevel SF in the regime where the length of the excited column L is greater than the maximum value of the Arecchi-Courtens length (Lc). The observed variation of SF peak intensity (Ifl) and time delay for SF evolution (τD) with number of atoms in the excited state (N) resemble theoretically predicted SF scaling laws for transverse excitation, namely Ifl∝N and tau_D ∝ 1/{sqrt N} although the experimental condition is similar to the swept excitation. This could be due to the Rabi frequency associated with the pump transition which is comparable to the SF delay time precluding the initiation of SF at different times along the sample and results in transverse (instantaneous) excitation. The experimental τD values were found to be in agreement with the quantum mechanical calculations describing SF.

  5. Tm:YLF Pumped Ho:YAG and Ho:LuAG Lasers

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Reichle, Donald J.; Walsh, Brian M.; Axenson, Theresa J.

    2004-01-01

    Room temperature Ho:YAG and Ho:LuAG lasers pumped by a Tm:YLF laser demonstrated a 3.4 mJ threshold and 0.41 slope efficiency, incident optical to laser output energy. Results for numerous rod lengths, Ho concentrations, and output mirror reflectivities are presented.

  6. 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.

  7. 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.

  8. Spin-Exchange Optical Pumping of Alkali Salts

    NASA Astrophysics Data System (ADS)

    Olsen, Ben; Patton, Brian; Jau, Yuan-Yu; Happer, Will; Ishikawa, Kiyoshi

    2008-05-01

    Spin-Exchange Optical Pumping (SEOP) is a technique used to polarize nuclei in excess of their equilibrium limit. SEOP is achieved by optically pumping an alkali vapor which then transfers angular momentum to the nuclei of interest. We have recently hyperpolarized ^133Cs nuclei in solid CsH using SEOP, achieving magnetizations more than an order of magnitude larger than the thermal equilibrium value.ootnotetextIshikawa et. al., Phys. Rev. Lett. 98, 183004 (2007) In subsequent work, we investigate the mechanisms underlying this transfer of angular momentum. By optically pumping Cs vapor with laser light resonant with several optical transitions, each yielding different nuclear and electronic spin currents to the solid, we attempt to determine the source of transferred angular momentum. Early evidence suggests both electronic and nuclear spin polarization in the vapor contribute to ^133Cs nuclear polarization in the salt. The ^1H polarization is also mildly affected by optical pumping. We compare these results to numerical simulations and to results from other alkali salts. Further studies are warranted to discover if polarization can be transferred to other nuclei (e.g., alkali salts) on the cell walls.

  9. 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.

  10. Highly efficient passively Q-switched Yb:YAG microchip lasers under high intensity laser-diode pumping

    NASA Astrophysics Data System (ADS)

    Dong, J.; Wang, G. Y.; Cheng, Y.

    2013-03-01

    A highly efficient Cr4+:YAG passively Q-switched Yb:YAG microchip laser has been demonstrated at room temperature by high-brightness single-emitter laser-diode pumping. The maximum average output power of 1.53 W was obtained at the absorbed pump power of 3.5 W. The optical-to-optical efficiency was 44% with respect to the absorbed pump power. Laser pulses with a pulse width of 2.9 ns, pulse energy of 11.3 μJ, and peak power of 3.9 kW were obtained. The high pump power intensity from a high-brightness single-emitter laser-diode plays an important role in the alleviation of thermal effects and the efficient performance of Cr4+:YAG passively Q-switched Yb:YAG microchip lasers.

  11. Multiwatt continuous wave Nd:KGW laser with hot-band diode pumping.

    PubMed

    Talukder, Rubel Chandra; Eibna Halim, Md Zubaer; Waritanant, Tanant; Major, Arkady

    2016-08-15

    We have demonstrated what we believe is the first continuous wave neodymium-doped potassium gadolinium tungstate crystal (Nd:KGW) laser with hot-band diode pumping at ∼910  nm. This pumping wavelength reduced the quantum defect by >46% as compared to conventional ∼810  nm pumping and resulted in significantly lower thermal lensing. The laser produced 2.9 W of average output power at 1067 nm in a diffraction-limited beam for an absorbed pump power of 8.3 W. The slope efficiency and optical-to-optical efficiency were found to be 43% and 35%, respectively. Significant reduction of quantum defect offered by this pumping wavelength and availability of suitable high-power laser diodes opens up an attractive way to further power and efficiency scaling of Nd:KGW lasers. PMID:27519095

  12. 520-W continuous-wave diode corner-pumped composite Yb:YAG slab laser.

    PubMed

    Liu, Qiang; Gong, Mali; Lu, Fuyuan; Gong, Wupeng; Li, Chen

    2005-04-01

    We present a pumping scheme for a quasi-three-level solid-state laser. The scheme uses a slab laser configuration with the pump light incident from the slab corners. A diode-corner-pumped composite Yb:YAG-YAG slab laser operating in high-power cw mode was designed to prove the scheme. As much as 520 W of output power was obtained from a single 1-mm-thick composite slab with 0.5-at. %-doped Yb:YAG. The slope efficiency and the optical-to-optical efficiency with respect to the pump power were 32% and 25%, respectively. This result shows the validity of the corner-pumping concept and its feasibility in the development of high-power solid-state lasers. PMID:15832919

  13. Ultra-stable flashlamp-pumped laser

    NASA Astrophysics Data System (ADS)

    Brachmann, A.; Clendenin, J.; Galetto, T.; Maruyama, T.; Sodja, J.; Turner, J.; Woods, M.

    2003-07-01

    We present the design and experimental results for the flashlamp-pumped Ti:Sapphire laser system used at the Stanford Linear Accelerator Center (SLAC). This laser system is used in conjunction with the Polarized Electron Source to generate polarized electron beams for fixed target experiments (e.g. the E-158 experiment). The unique capabilities such as high pulse-to-pulse stability, long pulse length and high repetition rate is discussed. Emphasis is placed on recent modifications of the laser system, which allow ultra-stable operation with 0.5% rms intensity jitter.

  14. 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.

  15. High power, tunable mid-infrared BaGa4Se7 optical parametric oscillator pumped by a 2.1 μm Ho:YAG laser.

    PubMed

    Yuan, Jin-He; Li, Chao; Yao, Bao-Quan; Yao, Ji-Yong; Duan, Xiao-Ming; Li, Ying-Yi; Shen, Ying-Jie; Wu, Yi-Cheng; Cui, Zheng; Dai, Tong-Yu

    2016-03-21

    We, for the first time, demonstrate a tunable mid-infrared BaGa4Se7-based optical parametric oscillator pumped by a acousto-optical Q-switched Ho:YAG laser at 2090.6 nm. Up to 1.55 W of average power was generated in the 3-5 μm range, corresponding to an optical-to-optical conversion efficiency of 14.4% and a slope efficiency of 19.9%. The mid-IR radiation spectra were also seriously researched at different phase-matched angles. The tunable range was 3.49-4.13 μm for the signal, and 5.19-4.34 μm for the idler. PMID:27136802

  16. A High Efficiency Grazing Incidence Pumped X-ray Laser

    SciTech Connect

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

    2006-08-31

    The main objective of the project is to demonstrate a proof-of-principle, new type of high efficiency, short wavelength x-ray laser source that will operate at unprecedented high repetition rates (10Hz) that could be scaled to 1kHz or higher. The development of a high average power, tabletop x-ray laser would serve to complement the wavelength range of 3rd and future 4th generation light sources, e.g. the LCLS, being developed by DOE-Basic Energy Sciences. The latter are large, expensive, central, synchrotron-based facilities while the tabletop x-ray laser is compact, high-power laser-driven, and relatively inexpensive. The demonstration of such a unique, ultra-fast source would allow us to attract funding from DOE-BES, NSF and other agencies to pursue probing of diverse materials undergoing ultrafast changes. Secondly, this capability would have a profound impact on the semiconductor industry since a coherent x-ray laser source would be ideal for ''at wavelength'' {approx}13 nm metrology and microscopy of optics and masks used in EUV lithography. The project has major technical challenges. We will perform grazing-incidence pumped laser-plasma experiments in flat or groove targets which are required to improve the pumping efficiency by ten times. Plasma density characterization using our existing unique picosecond x-ray laser interferometry of laser-irradiated targets is necessary. Simulations of optical laser propagation as well as x-ray laser production and propagation through freely expanding and confined plasma geometries are essential. The research would be conducted using the Physics Directorate Callisto and COMET high power lasers. At the end of the project, we expect to have a high-efficiency x-ray laser scheme operating below 20 nm at 10Hz with a pulse duration of {approx}2 ps. This will represent the state-of-the-art in x-ray lasers and would be a major step forward from our present picosecond laser-driven x-ray lasers. There is an added bonus of creating

  17. 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.

  18. High Sensitivity Optically Pumped Quantum Magnetometer

    PubMed Central

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  19. Fiber optics interface for a dye laser oscillator and method

    DOEpatents

    Johnson, Steve A.; Seppala, Lynn G.

    1986-01-01

    A dye laser oscillator in which one light beam is used to pump a continuous tream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

  20. Fiber optics interface for a dye laser oscillator and method

    DOEpatents

    Johnson, S.A.; Seppala, L.G.

    1984-06-13

    A dye laser oscillator in which one light beam is used to pump a continuous stream of dye within a cooperating dye chamber for producing a second, different beam is generally disclosed herein along with a specific arrangement including an optical fiber and a fiber optics interface for directing the pumping beam into the dye chamber. The specific fiber optics interface illustrated includes three cooperating lenses which together image one particular dimension of the pumping beam into the dye chamber from the output end of the optical fiber in order to insure that the dye chamber is properly illuminated by the pumping beam.

  1. 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.

  2. Diode end pumped laser and harmonic generator using same

    NASA Technical Reports Server (NTRS)

    Byer, Robert L. (Inventor); Dixon, George J. (Inventor); Kane, Thomas J. (Inventor)

    1988-01-01

    A second harmonic, optical generator is disclosed in which a laser diode produces an output pumping beam which is focused by means of a graded, refractive index rod lens into a rod of lasant material, such as Nd:YAG, disposed within an optical resonator to pump the lasant material and to excite the optical resonator at a fundamental wavelength. A non-linear electro-optic material such as MgO:LiNbO.sub.3 is coupled to the excited, fundamental mode of the optical resonator to produce a non-linear interaction with the fundamental wavelength producing a harmonic. In one embodiment, the gain medium and the non-linear material are disposed within an optical resonator defined by a pair of reflectors, one of which is formed on a face of the gain medium and the second of which is formed on a face of the non-linear medium. In another embodiment, the non-linear, electro-optic material is doped with the lasant ion such that the gain medium and the non-linear doubling material are co-extensive in volume. In another embodiment, a non-linear, doubling material is disposed in an optical resonator external of the laser gai medium for improved stability of the second harmonic generation process. In another embodiment, the laser gain medium andthe non-linear material are bonded together by means of an optically transparent cement to form a mechanically stable, monolithic structure. In another embodiment, the non-linear material has reflective faces formed thereon to define a ring resonator to decouple reflections from the non-linear medium back to the gain medium for improved stability.

  3. 100  J-level nanosecond pulsed diode pumped solid state laser.

    PubMed

    Banerjee, Saumyabrata; Mason, Paul D; Ertel, Klaus; Jonathan Phillips, P; De Vido, Mariastefania; Chekhlov, Oleg; Divoky, Martin; Pilar, Jan; Smith, Jodie; Butcher, Thomas; Lintern, Andrew; Tomlinson, Steph; Shaikh, Waseem; Hooker, Chris; Lucianetti, Antonio; Hernandez-Gomez, Cristina; Mocek, Tomas; Edwards, Chris; Collier, John L

    2016-05-01

    We report on the successful demonstration of a 100 J-level, diode pumped solid state laser based on cryogenic gas cooled, multi-slab ceramic Yb:YAG amplifier technology. When operated at 175 K, the system delivered a pulse energy of 107 J at a 1 Hz repetition rate and 10 ns pulse duration, pumped by 506 J of diode energy at 940 nm, corresponding to an optical-to-optical efficiency of 21%. To the best of our knowledge, this represents the highest energy obtained from a nanosecond pulsed diode pumped solid state laser. This demonstration confirms the energy scalability of the diode pumped optical laser for experiments laser architecture. PMID:27128081

  4. 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.

  5. Laser action by optically depumping lower states

    DOEpatents

    Krupke, William F.

    1977-01-01

    A method and apparatus for obtaining laser action between an upper energy level and a lower energy level of a gaseous medium, which comprises populating the upper energy level to some degree (short of achieving a conventional inverted population) by any suitable pumping means, and thereafter establishing an inverted population by transiently and selectively depumping the lower energy level such as by exposing the medium to an intense source of radiation which selectively causes the transformation of the lower energy level species to some other energy level. Thus, a thermally pumped/optically depumped gas laser system is produced.

  6. Laser action by optically depumping lower states

    DOEpatents

    Krupke, W.F.

    1975-11-26

    A method and apparatus are described for obtaining laser action between an upper energy level and a lower energy level of a gaseous medium. The upper energy level is populated to some degree (short of achieving a conventional inverted population) by any suitable pumping means, and an inverted population is established by transiently and selectively depumping the lower energy level. The depumping may be done by exposing the medium to an intense source of radiation which selectively causes the transformation of the lower energy level species to some other energy level. Thus, a thermally pumped/optically depumped gas laser system is produced.

  7. Highly efficient neodymium:yttrium aluminum garnet laser end pumped by a semiconductor laser array

    NASA Technical Reports Server (NTRS)

    Sipes, D. L.

    1985-01-01

    In recent experiments, 80-mW CW power in a single mode has been achieved from a neodymium:yttrium aluminum garnet (Nd:YAG) laser with only 1 W of electrical power input to a single semiconductor laser array pump. This corresponds to an overall efficiency of 8 percent, the highest reported CW efficiency for a Nd:YAG laser. A tightly focused semiconductor laser end pump configuration is used to achieve high pumping intensities (on the order of 1 kW/sq cm), which in turn causes the photon to photon conversion efficiency to approach the quantum efficiency (76 percent for Nd:YAG at 1.06 microns pumped at 0.810 micron). This is achieved despite the dual-lobed nature of the pump. Through the use of simple beam-combining schemes (e.g., polarization coupling and multireflection point pumping), output powers over 1 W and overall electrical to optical efficiencies as high as 10 percent are expected.

  8. Optical parametric oscillator of quasi-phasematched LiNbO 3 pumped by a compact high repetition rate single-frequency passively Q-switched Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Bäder, U.; Bartschke, J.; Klimov, I.; Borsutzky, A.; Wallenstein, R.

    1998-02-01

    We report on an efficient diode pumped compact source of pulsed tunable infrared radiation based on a high repetition rate single frequency passively Q-switched Nd:YAG laser and an optical parametric oscillator (OPO) of quasi-phase matched LiNbO 3. When pumped by 5.4 W of 810 nm cw diode laser radiation the Nd:YAG laser (which is passively Q-switched by a Cr 4+:GSGG saturable absorber) oscillates on a single-longitudinal mode and emits in a diffraction limited beam light pulses with duration of 2 ns, pulse energy of 100 μJ, repetition rate of 1.1 kHz and average power of 110 mW. This radiation excites an OPO of quasi-phase matched LiNbO 3. The OPO generates signal and idler radiation which is tunable in the range of 1.46-1.61 μm and 3.13-3.92 μm, respectively. Tuning is achieved by using 8 different poling periods ( Λ=28.5-29.9 μm) and by changing the crystal's temperature in the range of 80-160°C. The measured signal pulse energy is ES =22 μJ, the average signal output power PS =24 mW, the measured idler power PI =2.5 mW and the pump depletion 33%.

  9. 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.

  10. A Multiterawatt Laser Using a High-Contrast, Optical Parametric Chirped-Pulse Presamplifier

    SciTech Connect

    Bagnoud, V.; Puth, J.; Begishev, I.; Guardalben, M.; Zuegel, J.D.; Forget, N.; LeBlanc, C.

    2005-09-30

    A laser has been built that uses optical parametric chirped-pulse preamplification and a glass booster amplifier. We review the performance of the 5-Hz, multijoule OPCPA pump laser, the 370-mJ OPCPA, and the overall laser.

  11. 125-mJ diode-pumped injection-seeded Ho:Tm:YLF laser.

    PubMed

    Yu, J; Singh, U N; Barnes, N P; Petros, M

    1998-05-15

    We describe a diode-pumped, room-temperature Ho:Tm:YLF power oscillator with an optical-to-optical efficiency of 0.03. A Q -switched output energy of as much as 125 mJ at 6 Hz with a pulse width of 170 ns was obtained. Single-frequency, nearly transform-limited operation of the laser was achieved by injection seeding. Laser performance as a function of laser rod temperature and pump intensity was also investigated. The high power and high beam quality of this laser make it well suited for use as a coherent wind lidar transmitter on a space platform. PMID:18087340

  12. 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.

  13. Short pulse width UV laser at 355 nm based on pulse LD side-pumped ceramic Nd:YAG and BBO electro-optical Q-switched

    NASA Astrophysics Data System (ADS)

    Bai, Y.; Chen, X. M.; Lu, B. L.; Ren, Z. Y.; Bai, J. T.

    2012-02-01

    355 nm UV laser was obtained with a pulse width of less than 5 ns and a peak power at megawatt level by adopting the 808 nm pulse laser diode (LD) side-pumped ceramic Nd:YAG and BBO crystal electrooptical Q-switched. The single-pulse energy was measured to be 24.3 mJ with 4.86 ns pulse width and 5.11 MW peak power at a repetition rate of 1Hz under a 120 A pump current. Using a volume of beam splitting mirrors, wavelength outputs at 1064, 532, and 355 nm pulse laser was obtained simultaneously with a respective average output power of 656.6, 357.1, and 260.5 mW, the beam quality factor M 2 are ( M {/x - 1064 2} = 5.83, M {/y - 1064 2} = 5.61), ( M {/x - 532 2} = 4.25, M {/y - 532 2} = 4.08) and ( M {/x - 355 2} = 6.32, M {/y - 355 2} = 6.15), corresponding to a conversion efficiency at 11% from 1064 to 355 nm.

  14. Diffractive Combiner of Single-Mode Pump Laser-Diode Beams

    NASA Technical Reports Server (NTRS)

    Liu, Duncan; Wilson, Daniel; Qiu, Yueming; Forouhar, Siamak

    2007-01-01

    An optical beam combiner now under development would make it possible to use the outputs of multiple single-mode laser diodes to pump a neodymium: yttrium aluminum garnet (Nd:YAG) nonplanar ring oscillator (NPRO) laser while ensuring that the laser operates at only a single desired frequency. Heretofore, an Nd:YAG NPRO like the present one has been pumped by a single multimode laser-diode beam delivered via an optical fiber. It would be desirable to use multiple pump laser diodes to increase reliability beyond that obtainable from a single pump laser diode. However, as explained below, simplistically coupling multiple multimode laser-diode beams through a fiber-optic combiner would entail a significant reduction in coupling efficiency, and lasing would occur at one or more other frequencies in addition to the single desired frequency. Figure 1 schematically illustrates the principle of operation of a laser-diode-pumped Nd:YAG NPRO. The laser beam path is confined in a Nd:YAG crystal by means of total internal reflections on the three back facets and a partial-reflection coating on the front facet. The wavelength of the pump beam - 808 nm - is the wavelength most strongly absorbed by the Nd:YAG crystal. The crystal can lase at a wavelength of either 1,064 nm or 1,319 nm - which one depending on the optical coating on the front facet. A thermal lens effect induced by the pump beam enables stable lasing in the lowest-order transverse electromagnetic mode (the TEM00 mode). The frequency of this laser is very stable because of the mechanical stability of the laser crystal and the unidirectional nature of the lasing. The unidirectionality is a result of the combined effects of (1) a Faraday rotation induced by an externally applied magnetic field and (2) polarization associated with non-normal incidence and reflection on the front facet.

  15. Spontaneous emission effects in optically pumped x-ray FEL

    SciTech Connect

    Smetanin, I.V.; Grigor`ev, S.V.

    1995-12-31

    An effect of spontaneous emission in both quantum and classical regimes of the optically pumped X-ray free electron laser (FEL) in investigated. The quantum properties of an FEL are determined by the ratio of the separation {h_bar} between the absorption and emission lines (i.e. the quanta emitted) and their effective width {Delta}{epsilon} {eta}={h_bar}/{Delta}{epsilon}. In the conventional classical regime {eta} {much_lt} 1 an electron emits and absorbes a great number of shortwavelength photons over the interaction region, the gain in FEL being the result of these competitive processes. In the quantum limit {eta} {much_gt} 1 the emission and absorption lines are completely separated and thus the FEL becomes a two-level quantum oscillator with a completely inverted active medium. Spontaneous emission causes the electron to leave the range of energies where resonant interaction with the laser field occurs, thus effectively reducing the number of particles that take part in generating the induced X-ray signal. This effect is found to be crucial for lasing in optically pumped X-ray FEL. The characteristic relaxation times are calculated for both classical and quantum FEL regimes. It is shown that spontaneous emission results in FEL electron beam threshold current, which is of rather high value. An optimal range of pumping laser intensities is determined.

  16. 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.

  17. Efficient upconversion-pumped continuous wave Er3+:LiLuF4 lasers

    NASA Astrophysics Data System (ADS)

    Moglia, Francesca; Müller, Sebastian; Reichert, Fabian; Metz, Philip W.; Calmano, Thomas; Kränkel, Christian; Heumann, Ernst; Huber, Günter

    2015-04-01

    We report on detailed spectroscopic investigations and efficient visible upconversion laser operation of Er3+:LiLuF4. This material allows for efficient resonant excited-state-absorption (ESA) pumping at 974 nm. Under spectroscopic conditions without external feedback, ESA at the laser wavelength of 552 nm prevails stimulated emission. Under lasing conditions in a resonant cavity, the high intracavity photon density bleaches the ESA at 552 nm, allowing for efficient cw laser operation. We obtained the highest output power of any room-temperature crystalline upconversion laser. The laser achieves a cw output power of 774 mW at a slope efficiency of 19% with respect to the incident pump power delivered by an optically-pumped semiconductor laser. The absorption efficiency of the pump radiation is estimated to be below 50%. To exploit the high confinement in waveguides for this laser, we employed femtosecond-laser pulses to inscribe a cladding of parallel tracks of modified material into Er3+:LiLuF4 crystals. The core material allows for low-loss waveguiding at pump and laser wavelengths. Under Ti:sapphire pumping at 974 nm, the first crystalline upconversion waveguide laser has been realized. We obtained waveguide-laser operation with up to 10 mW of output power at 553 nm.

  18. Synchronously pumped femtosecond optical parametric oscillator with broadband chirped mirrors

    NASA Astrophysics Data System (ADS)

    Stankevičiūte, Karolina; Melnikas, Simas; Kičas, Simonas; Trišauskas, Lukas; Vengelis, Julius; Grigonis, Rimantas; Vengris, Mikas; Sirutkaitis, Valdas

    2015-05-01

    We present results obtained during investigation of synchronously pumped optical parametric oscillator (SPOPO) with broadband complementary chirped mirror pairs (CMP). The SPOPO based on β-BBO nonlinear crystal is pumped by second harmonic of femtosecond Yb:KGW laser and provides signal pulses tunable over spectral range from 625 to 980 nm. More than 500 mW are generated in the signal beam, giving up to 27 % pump power to signal power conversion efficiency. The plane SPOPO cavity mirror pairs were specially designed to provide 99 % reflection in broad spectral range corresponding to signal wavelength tuning (630-1030 nm) and to suppress group delay dispersion (GDD) oscillations down to +/-10 fs2. Dispersion properties of designed mirrors were tested with white light interferometer (WLI) and attributed to the SPOPO tuning behaviour.

  19. Laser Wakefield acceleration with high relativistic pumps

    SciTech Connect

    Katsouleas, T.; Mori, W.B. ); Darrow, C.B. )

    1989-10-15

    Preliminary scaling laws are found for the laser wakefield accelerator in the very non-linear regime where the normalized laser pump strengh {ital V}{sub osc}{ital c}={ital eE}{sub 0}/{ital m}{omega}{sub 0}{ital c}{gt}1. Two important non-linear effects are an increase in the wake phase velocity (and hence the particle dephasing length) and an increase in the laser pulse length for optimal wake excitation. Application of the results to the proposed Livermore High-Brightness Lasers (HBL) is discussed here and in the accompanying paper by C. B. Darrow, {ital et} {ital al}. A preliminary 1-D PIC simulation is presented. {copyright} 1989 American Institute of Physics

  20. 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.

  1. 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.

  2. Diode pumped alkali lasers (DPALs): an overview

    NASA Astrophysics Data System (ADS)

    Krupke, William F.

    2008-05-01

    The concept of power-scalable, high beam-quality diode pumped alkali lasers was introduced in 2003 [Krupke, US Patent No. 6,643,311; Opt. Letters, 28, 2336 (2003)]. Since then several laboratory DPAL devices have been reported on, confirming many of the spectroscopic, kinetic, and laser characteristics projected from literature data. This talk will present an overview of the DPAL concept, summarize key relevant properties of the cesium, rubidium, and potassium alkali vapor gain media so-far examined, outline power scaling considerations, and highlight results of published DPAL laboratory experiments.

  3. Direct nuclear-pumped laser amplifier

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1981-01-01

    A (He-3)-Xe gas mixture, excited by the He-3(n,p)H-3 reaction, has been employed to amplify the output of a (He-3)Xe direct nuclear-pumped laser. Lasing occurred at the 2.63 micron line of XeI in the oscillator. The oscillator output was reflected through 180 deg and passed through the amplifier system. Power measurements of the oscillator output and the amplifier output show the laser power to be amplified by a factor of 3 for the (He-3)-Xe system. Amplification by a factor of 5 was obtained for a (He-3)-CO system.

  4. Cr-doped solid state lasers pumped by visible laser diodes

    NASA Astrophysics Data System (ADS)

    Scheps, Richard

    1992-01-01

    Operation of Cr 3+-doped solid state lasers pumped by visible laser diodes is discussed, with performance of three of the highest efficiency devices reported in detail. Cr:LiCaAlF 6 (Cr:LiCAF), Cr:LiSrAlF 6 (Cr:LiSAF) and Cr,Nd: Gd 3Sc 2Ga 3O 12 (Cr,Nd: GSGG) have all demonstrated low threshold and high slope efficiency when pumped with diodide power as high as 1 W. Laser emission levels have approached 200 mW while slope efficiencies as high as 50% were measured. Optical characterization 3ata for each laser resonator are presented and prospects for near-term power scaling are discussed.

  5. 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

  6. Solar-pumped laser for free space power transmission

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1989-01-01

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

  7. 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. PMID:22274245

  8. Definition and analysis of the lineshape matching coefficient in diode-pumped alkali vapor lasers

    NASA Astrophysics Data System (ADS)

    Shen, Binglin; Pan, Bailiang; Yang, Jing; Qian, Aiqing; Jiao, Jian

    2014-12-01

    For diode-pumped alkali lasers (DPALs), the matching of lineshape between D2 absorption line and pump light greatly affects the properties of laser output; however, there is rare theoretical study on the quantitative description of the lineshape matching coefficient. In this paper, we put forward a formula to describe the lineshape matching coefficient that represents the matching degree between D2 absorption line and pump light. Dependences of the matching coefficient and optical-optical efficiency on the linewidth ratio between D2 absorption line and pump light, and the center frequency shift of pump light caused by mode hopping are calculated and compared with experimental results in literatures. Results show the definition of lineshape matching coefficient can provide an effective way to improve the pump efficiency of DPALs.

  9. 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.

  10. Efficient flashlamp-pumped IBr laser

    NASA Technical Reports Server (NTRS)

    Zapata, L. E.; De Young, R. J.

    1985-01-01

    The operating characteristics and scaling parameters of a flashlamp-pumped, 4-m-long IBr laser were investigated to further evaluate its potential as a solar-pumped laser. A peak power of 3 kW/sq cm at 2.7 microns was achieved at 4-Torr IBr pressure. A gain of 0.07 per m was measured at a maximum capacitor discharge energy of 4 kJ. The threshold input power necessary for lasing was found to decrease by a factor of 4 and the laser pulse width increased fourfold as the active gain length was increased from 1 to 4 m. A maximum pulse width of 120 microseconds was achieved with 10-Torr argon diluent added to 4-Torr IBr. Quenching of the excited state by the parent molecule was shown to be unimportant for pressures less than 4-Torr IBr. An intrinsic efficiency in the range of 12 percent has been measured for flashlamp-pumped IBr.

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

    PubMed

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

    2013-10-21

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

  12. 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.

  13. 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.

  14. Double-end-pumped Nd:YVO4 slab laser at 1064 nm.

    PubMed

    Xu, Liu; Zhang, Hengli; He, Jingliang; Yu, Xilong; Cui, Li; Mao, Yefei; Sun, Xiao; Lin, Xin; Xing, Jichuan; Xin, Jianguo

    2012-04-20

    We demonstrate a high-power laser diode stacks double-end-pumped Nd:YVO4 1064 nm slab laser with a folded stable-unstable hybrid resonator. An output power of 220 W was obtained at the pump power of 490 W with optical conversion efficiency of 44.9%. At the output power of 202 W, the M2 factors in the unstable direction and in the stable direction were 1.7 and 2.3, respectively. PMID:22534909

  15. Diode-pumped Q-switched Nd{sup 3+} : YAG laser operating in a wide temperature range without thermal stabilisation of pump diodes

    SciTech Connect

    Vainshenker, A E; Vilenskiy, A V; Kazakov, A A; Lysoy, B G; Mikhailov, L K; Pashkov, V A

    2013-02-28

    A model sample of a compact low-power-consumption Nd{sup 3+} : YAG laser emitting 20-mJ pulses with a pulse repetition rate up to 20 Hz (in cyclic duty) at a wavelength of 1064 nm is developed and studied. The laser is designed for operating at external temperatures from -40 to +50 deg C. This was achieved by using quasi-end diode pumping without thermal stabilisation of pump diodes. (laser optics 2012)

  16. Polarization/Spatial Combining of Laser-Diode Pump Beams

    NASA Technical Reports Server (NTRS)

    Gelsinger, Paul; Liu, Duncan

    2008-01-01

    A breadboard version of an optical beam combiner is depicted which make it possible to use the outputs of any or all of four multimode laser diodes to pump a non-planar ring oscillator (NPRO) laser. The output of each laser diode has a single-mode profile in the meridional plane containing an axis denoted the 'fast' axis and a narrower multimode profile in the orthogonal meridional plane, which contains an axis denoted the 'slow' axis and a narrower multimode profile in the orthogonal meridional plane, which contains an axis denoted the 'slow' axis. One of the purposes served by the beam-combining optics is to reduce the fast-axis numerical aperture (NA) of the laser-diode output to match the NA of the optical fiber. Along the slow axis, the unmodified laser-diode NA is already well matched to the fiber optic NA, so no further slow-axis beam shaping is needed. In this beam combiner, the laser-diode outputs are collimated by aspherical lenses, then half-wave plates and polarizing beam splitters are used to combine the four collimated beams into two beams. Spatial combination of the two beams and coupling into the optical fiber is effected by use of anamorphic prisms, mirrors, and a focusing lens. The anamorphic prisms are critical elements in the NA-matching scheme, in that they reduce the fast-axis beam width to 1/6 of its original values. Inasmuch as no slow-axis beam shaping is needed, the collimating and focusing lenses are matched for 1:1 iumaging. Because these lenses are well corrected for infinite conjugates the combiner offers diffraction-limited performance along both the fast and slow axes.

  17. Two and Three Beam Pumped Optical Parametric Amplifier of Chirped Pulses

    NASA Astrophysics Data System (ADS)

    Ališauskas, S.; Butkus, R.; Pyragaitė, V.; Smilgevičius, V.; Stabinis, A.; Piskarskas, A.

    2010-04-01

    We present two and three beam pumped optical parametric amplifier of broadband chirped pulses. The seed pulses from Ti:sapphire oscillator were stretched and amplified in a non-collinear geometry pumping with up to three beams derived from independent laser amplifiers. The signal with ˜90 nm bandwidth was amplified up to 0.72 mJ. The conversion efficiency dependence on intersection angles of pump beams is also revealed.

  18. Efficient diode double-end-pumped Nd:YVO4 laser operating at 1342nm.

    PubMed

    Ogilvy, Hamish; Withford, Michael; Dekker, Peter; Piper, James

    2003-09-22

    A Nd:YVO4 laser producing over 8W cw TEM00 at 1342nm with slope efficiency of 42% and optical to optical conversion efficiency of 33% has been demonstrated. Low neodymium doping concentration helps to reduce thermal loading in the laser crystal and increase achievable output power. While single end pumping approaches the crystal fracture limit, double-end-pumping effectively divides the thermal loading between the two ends of the laser crystal, allowing for reduced risk of fracture and greater power-scalability. Intracavity frequency doubling in LBO generated cw output powers over 900mW at 671nm. PMID:19471351

  19. 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.

  20. Flow tube used to cool solar-pumped laser

    NASA Technical Reports Server (NTRS)

    1968-01-01

    A flow tube has been designed and constructed to provide two major functions in the application of a laser beam for transmission of both sound and video. It maintains the YAG laser at the proper operating temperature of 300 degrees K under solar pumping conditions, and it serves as a pump cavity for the laser crystal.

  1. Electron-spin-reversal phenomenon in optically pumped rubidium

    SciTech Connect

    Norrgard, E. B.; Dreiling, J. M.; Gay, T. J.; Tupa, D.

    2010-09-15

    We have studied the optical pumping of mixtures of Rb vapor and N{sub 2} buffer gas by laser light tuned to the D{sub 1} transition having a spectral width of {approx}500 MHz. The Rb densities are of the order of 10{sup 13} cm{sup -3}, while the buffer-gas pressures range from 0.1 to 10 torr. As the frequency of the right-hand circularly polarized laser is varied across the D{sub 1} absorption profile, the electron spin polarization of the Rb is found to take on negative values for small negative values of pump detuning from the absorption profile center. This occurs for N{sub 2} pressures below {approx}1 torr; at 10 torr the electron spins consistently point in the same direction as the angular momentum of the pump light. The spin-reversal effect can be understood in terms of populations of the F=2 ({sup 85}Rb) and F=1 ({sup 87}Rb) states caused by small unpolarized fractions in the pump beam and its elimination in terms of pressure broadening caused by the N{sub 2} buffer gas. We speculate that this effect could be used for fast Rb spin modulation.

  2. Nuclear-pumped CO2 laser

    NASA Technical Reports Server (NTRS)

    Rowe, M.

    1979-01-01

    The He-3 (n,p)T reaction was examined as an energy source for a CO2 laser. For this purpose He-3 was added to a functioning CO2 electrically excited laser. Initially the laser was run electrically with 12 torr total pressure. The gas mixture was 1:1:8, CO2:N2:He. At zero reactor power, the laser was tested in place next to the core of the Georgia Tech. Research Reactor. After verification of laser action He-3 was added to the system. The He-3 partial pressures of 10 torr, 50 torr, and 300 torr were added in three separate reactor runs. Reactor power ranged from zero to 5 million watts, which corresponds to a peak flux of 10 to the 14th power/sq cm. At reactor powers greater than 10 kW, gain of up to 30 percent was shown. However, indications are this may be due to gamma excitation rather than caused by the He-3 (n,p)T reaction. These results do agree with the data of past CO2 nuclear pumped laser experiments.

  3. Optically pumped 1.3  μm room-temperature InAs quantum-dot micro-disk lasers directly grown on (001) silicon.

    PubMed

    Wan, Yating; Li, Qiang; Liu, Alan Y; Gossard, Arthur C; Bowers, John E; Hu, Evelyn L; Lau, Kei May

    2016-04-01

    Direct integration of high-performance laser diodes on silicon will dramatically transform the world of photonics, expediting the progress toward low-cost and compact photonic integrated circuits (PICs) on the mainstream silicon platform. Here, we report, to the best of our knowledge, the first 1.3 μm room-temperature continuous-wave InAs quantum-dot micro-disk lasers epitaxially grown on industrial-compatible Si (001) substrates without offcut. The lasing threshold is as low as hundreds of microwatts, similar to the thresholds of identical lasers grown on a GaAs substrate. The heteroepitaxial structure employed here does not require the use of an absorptive germanium buffer and/or dislocation filter layers, both of which impede the efficient coupling of light from the laser active regions to silicon waveguides. This allows for full compatibility with the extensive silicon-on-insulator (SOI) technology. The large-area virtual GaAs (on Si) substrates can be directly adopted in various mature in-plane laser configurations, both optically and electrically. Thus, this demonstration represents a major advancement toward the commercial success of fully integrated silicon photonics. PMID:27192313

  4. Performance analysis and characterization of the Lumonics Inc. HyperDYE-300 laser-pumped dye laser. Final technical report

    SciTech Connect

    Taylor, T.S.; Davenport, W.E.; Ehrlich, J.J.

    1990-07-11

    The laser analyzed in this research, the Lumonics, Inc. HyperDYE-300 laser pumped dye laser, was procured via the FSTC D650 Program and was characterized in order to support the technology development of that program. The dye laser was pumped with a Neodymium:YAG q-switched laser and it utilized Rhodamine-6G in methanol. It was found to be tunable from about 545 nm to 590 nm and produced a maximum ouput energy of 56 percent of the pump beam energy. The analysis involved the measuring of optimum dye/solvent concentration, output energy versus tunability, optical efficiency versus tunability, temporal and spatial profiles, beam divergence, linewidth, and amplified spontaneous emission versus laser emission.

  5. Enhanced Ultraviolet Fluorescence due to Selective Optical Pumping with Extreme Ultraviolet Line Radiation

    NASA Astrophysics Data System (ADS)

    Trebes, James Edward

    In recent efforts to develop XUV and X-ray lasers resonant photo-excitation has been proposed as a possible pumping mechanism for producing population inversions. In this scheme intense line radiation from one ion species is used to pump selectively a nearly coincident absorption transition in a different ion species. Electrons are pumped from the ground state to a highly excited state producing a population inversion between excited states within the pumped ion. This thesis presents a series of experiments in which AIIII 3s-5p 56 nm XUV line radiation from a laser produced Al plasma is used to pump the CII 3p-5d 56 nm absorption transition in a C vacuum arc. The pumping results in UV enhanced fluorescence on the CII 3p-5d 213.8 nm transition and on transitions collisionally coupled to the 5d state. Time resolved measurements of these fluorescence channels are presented. These results are found to be in qualitative agreement with a collisional-radiative model of the pumping process. The limitations of the AIIII-CII optical pumping system for producing an UV laser are discussed. A new class of optically pumped lasers is proposed which avoids these limitations. The new class, based on Be-like ions, offers potential lasing lines from 200 nm to 20 nm. Parameter regimes for lasing are calculated.

  6. High-efficiency Tm-doped yttrium aluminum garnet laser pumped with a wavelength-locked laser diode

    NASA Astrophysics Data System (ADS)

    Huang, H. Z.; Huang, J. H.; Liu, H. G.; Dai, S. T.; Weng, W.; Zheng, H.; Ge, Y.; Li, J. H.; Deng, J.; Yang, X.; Lin, W. X.

    2016-09-01

    We first demonstrate a high-efficiency composite Tm-doped yttrium aluminum garnet laser end-pumped with a narrow-linewidth laser diode, which was locked at a wavelength of 784.9 nm with volume Bragg gratings. The locked pump wavelength was experimentally determined by the excitation peak, which was also the absorption peak of a 3.5 at.% Tm:YAG crystal around 785 nm, for the improvement of laser efficiency under high-intensity pumping. Under an absorbed pump power of 24.64 W, a maximum output power of 11.12 W at 2018 nm was obtained, corresponding to an optical to optical conversion efficiency of 45.1% and a slope efficiency of 52.4%.

  7. Continuous-wave and passively Q-switched cladding-pumped planar waveguide lasers.

    PubMed

    Beach, R J; Mitchell, S C; Meissner, H E; Meissner, O R; Krupke, W F; McMahon, J M; Bennett, W J; Shepherd, D P

    2001-06-15

    Greater than 12 W of average output power has been generated from a diode-pumped Yb:YAG cladding-pumped planar waveguide laser. The laser radiation developed is linearly polarized and diffraction limited in the guiding dimension. A slope efficiency of 0.5 W/W with a peak optical-optical conversion efficiency of 0.31 W/W is achieved. In a related structure, greater than 8 W of Q -switched average output power has been generated from a Nd:YAG cladding-pumped planar waveguide laser by incorporation of a Cr(4+): YAG passive Q switch monolithically into the waveguide structure. Pulse widths of 3 ns and pulse-repetition frequencies as high as 80 kHz have been demonstrated. A slope efficiency of 0.28 W/W with a peak optical-optical conversion efficiency of 0.21 W/W is achieved. PMID:18040479

  8. 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.

  9. New tunable flashlamp-pumped solid state Ti:sapphire laser for laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; Giannetas, V.; Charlton, Andrew; King, Terence A.

    1993-05-01

    Laser pulses from a flashlamp pumped, solid state Ti:sapphire laser (Vuman, free running untuned wavelength 792 nm, 2 microseconds pulse width and up to 240 mJ pulse energy) have been successfully and efficiently coupled into thin optical fibers. The coupling efficiency can be up to 67% for 300 micron and 43% for 200 micron core diameter optical fibers. With these two optical fibers in vitro laser lithotripsy has been performed successfully on various human calculi including gall bladder, kidney, ureter and salivary duct stones. The bright white flash of the induced plasma emission, strong shock waves, fiber recoil and stone propulsion and the splattering of the stone chips have been observed during the calculi fragmentation.

  10. Temporal Behavior of the Pump Pulses, Residual Pump Pulses, and THz Pulses for D2O Gas Pumped by a TEA CO2 Laser

    NASA Astrophysics Data System (ADS)

    Geng, Lijie; Zhang, Zhifeng; Zhai, Yusheng; Su, Yuling; Zhou, Fanghua; Qu, Yanchen; Zhao, Weijiang

    2016-08-01

    Temporal behavior of the pump pulses, residual pump pulses, and THz pulses for optically pumped D2O gas molecules was investigated by using a tunable TEA CO2 laser as the pumping source. The pulse profiles of pump laser pulses, residual pump pulses, and the THz output pulses were measured, simultaneously, at several different gas pressures. For THz pulse, the pulse delay between the THz pulse and the pump pulse was observed and the delay time was observed to increase from 40 to 70 ns with an increase in gas pressure from 500 to 1700 Pa. Both THz pulse broadening and compression were observed, and the pulse broadening effect transformed to the compression effect with increasing the gas pressure. For the residual pump pulse, the full width at half maximum (FWHM) of the main pulse decreased with increasing gas pressure, and the main pulse disappeared at high gas pressures. The secondary pulses were observed at high gas pressure, and the time intervals of about 518 and 435 ns were observed between the THz output pulse and the secondary residual pump pulse at the pressure of 1400 Pa and 1700 Pa, from which the vibrational relaxation time constants of about 5.45 and 5.55 μs Torr were obtained.

  11. Optical parametric oscillator of mid-IR, visible and UV ranges with synchronous pumping by a Q-switched mode-locked Nd : YAG laser

    NASA Astrophysics Data System (ADS)

    Donin, V. I.; Yakovin, M. D.; Yakovin, D. V.

    2016-07-01

    The parametric generation in a nonlinear PPLN crystal synchronously pumped by a Q-switched mode-locked Nd : YAG laser with a pulse duration of 45 ps is studied. The output pump intensity in the nonlinear crystal reaches ~10 GW cm-2. At a pulse repetition rate of 1 kHz, the average output power at the idler wavelength (~3.6 μm) is ~12 mW, the peak power is ~25 kW, and the conversion efficiency (with respect to the absorbed power) is ~10%. The radiation linewidth at the signal wavelength (~1.5 μm) is 13 cm-1. Along with the signal and idler waves, the output emission spectrum contains lines at wavelengths of 822, 754, 624, 532, 463, 442, 392 and 355 nm. The tunable radiation with wavelengths in the vicinity of 392, 463 and 822 nm is observed for the first time. The tuning ranges for the new lines are measured (5 – 10 nm) and their origin is explained.

  12. 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.

  13. An actively mode-locked Ho: YAG solid laser pumped by a Tm: YLF laser

    NASA Astrophysics Data System (ADS)

    Yao, B. Q.; Cui, Z.; Wang, J.; Duan, X. M.; Dai, T. Y.; Du, Y. Q.; Yuan, J. H.; Liu, W.

    2015-02-01

    A continuous wave mode-locked (CWML) Ho: YAG laser based on an acousto-optic modulator (AOM) pumped by a 1.9 μm Tm: YLF laser is demonstrated. This is the first time a report on an active CWML Ho: YAG laser has been published. A maximum output power of 1.04 W at 2097.25 nm in the CWML regime is obtained at a pump power of 13.2 W, corresponding to a slope efficiency of 13.3%. The mode-locked pulse repetition frequency is 82.76 MHz and the single pulse energy is 12.57 nJ. The mode-locked pulse width is 102 ps measured through a no-background second harmonic autocorrelation with KTP as the nonlinear crystal. Furthermore, the M2 factor is calculated to be 1.146.

  14. 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.

  15. 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.

  16. 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.

  17. DOE reactor-pumped laser program

    SciTech Connect

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

    1994-12-31

    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 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 highpower 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

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

  20. Flashlamp-pumped submicrosecond dye laser

    SciTech Connect

    Trusov, A.K.; Trusov, K.K.

    1985-02-01

    A laser flashlamp pumping system having an input energy of 330 J and a pulse duration of approx.230 nsec was developed experimentally and tests were made using a solution of rhodamine 6G under lasing conditions. The maximum lasing energy was 1.1 J, the efficiency was 0.33%, the angle of divergence of the beam at half-energy in a planar resonator was 1.2--1.3 mrad, and the illumination of an ethanol solution of rhodamine 6G halved the output energy when the intensity was 170 kJ/liter.

  1. Efficient corner-pumped Nd:YAG/YAG composite slab 1.1 µm laser.

    PubMed

    Liu, Huan; Liu, Qiang; Gong, Mali

    2010-09-13

    Corner pumping is a new pumping scheme for diode-pumped solid-state lasers, which has the advantages of high pump efficiency and favorable pump uniformity. A continuous-wave corner-pumped Nd:YAG/ YAG composite slab multi-wavelength laser at around 1.1 µm is demonstrated. The maximal output power is up to 12.06 W with an optical-to-optical conversion efficiency of 24%. At an output power of 10.3 W, the M(2) factors of beam quality at width and thickness directions are 7.71 and 2.44, respectively. With a LBO crystal inserted in the cavity, continuous-wave yellow-green laser with an output power of 841 mW is obtained. The experimental results show that a corner-pumping is a feasible scheme in the design of diode-pumped solid-state 1.1 µm lasers and their frequency-doubling to the yellow-green with low or medium output powers. PMID:20940856

  2. Note: Spin-exchange optical pumping in a van

    NASA Astrophysics Data System (ADS)

    Chauvin, C.; Liagre, L.; Boutin, C.; Mari, E.; Léonce, E.; Carret, G.; Coltrinari, B.; Berthault, P.

    2016-01-01

    The advent of spin-hyperpolarization techniques designed to overcome the sensitivity issue of nuclear magnetic resonance owing to polarization transfer from more ordered systems has recently raised great enthusiasm. However, the out-of-equilibrium character of the polarization requires a close proximity between the area of production and the site of use. We present here a mobile spin-exchange optical pumping setup that enables production of laser-polarized noble gases in a standalone mode, in close proximity to hospitals or research laboratories. Only compressed air and mains power need to be supplied by the host laboratory.

  3. Development of an optically pumped polarized deuterium target

    SciTech Connect

    Young, L.; Holt, R.J.; Green, M.C.; Kowalczyk, R.

    1987-01-01

    The development of a polarized deuterium target for internal use at an electron storage ring is of great interest for fundamental studies in nuclear physics. In order to achieve the maximum allowable target thickness, 10/sup 14/ nuclei/cm/sup 2/, consistent with various constraints imposed by the storage ring environment, a flux of 4 x 10/sup 17/ polarized atom/s must be provided. This flux exceeds the capability of conventional atomic beam sources by an order of magnitude. We have been developing an alternative source based upon the spin-exchange optical pumping method in which the flux is limited only by laser power. 7 refs., 1 fig.

  4. Optical Pumping Experiments on Next Generation Light Sources

    SciTech Connect

    Moon, S J; Fournier, K B; Scott, H; Chung, H K; Lee, R W

    2004-07-29

    Laser-based plasma spectroscopic techniques have been used with great success to determine the line shapes of atomic transitions in plasmas, study the population kinetics of atomic systems embedded in plasmas, and look at the redistribution of radiation. However, the possibilities for optical lasers end for plasmas with n{sub e}>10{sup 22}cm{sup -3} as light propagation is severely altered by the plasma. The construction of the Tesla Test Facility(TTF) at DESY(Deutsche Elektronen-Synchrotron), a short pulse tunable free electron laser in the vacuum-ultraviolet and soft X-ray regime (VUV FEL), based on the SASE(self amplified spontaneous emission) process, will provide a major advance in the capability for dense plasma-related research. This source will provide 10{sup 13} photons in a 200 fs duration pulse that is tunable from {approx} 6nm to 100nm. Since an VUV FEL will not have the limitation associated with optical lasers the entire field of high density plasmas kinetics in laser produced plasma will then be available to study with tunable source. Thus, one will be able to use this and other FEL x-ray sources to pump individual transitions creating enhanced population in the excited states that can easily be monitored. We show two case studies illuminating different aspects of plasma spectroscopy.

  5. Ultrafast laser-induced changes in optical properties of semiconductors

    SciTech Connect

    Chirila, C. C.; Lim, Freda C. H.; Gavaza, M. G.

    2012-04-01

    We study the effect of laser radiation on optical properties of semiconductors of industrial interest. The material is pumped with a laser of chosen central frequency, for which the absorption is maximal, thus inducing electron dynamics, which modifies the optical properties. By using an improved theoretical model, we study ultrafast dynamic changes in the refraction index and reflectivity corresponding to a wide frequency-interval of probing radiation and identify that interval where these optical changes are most significant.

  6. Diode-pumped Q-switched Nd:YLF laser at 1313 nm

    NASA Astrophysics Data System (ADS)

    Xu, Shan; Gao, Shufang; Zheng, Chunyan

    2016-06-01

    In this letter, we describe the operation of an end-pumped acousto-optic Q-switched Nd:YLF laser. According to the theoretical analysis and calculation for Nd:YLF crystal, the thermal focal length of σ-polarized laser is positive in plane-parallel resonator, while that of π-polarized laser is negative. Hence laser operation at σ-polarized 1313 nm should be stable in plane-parallel cavity. When absorbed pump power is 12.45 W and the pulse repetition frequency is 10 kHz, 3.1 W output laser at 1313 nm is achieved. As a result, the optical-optical conversion efficiency is 25.4 % and slope efficiency is 31.2 %, respectively.

  7. Rhodamine 6G laser pumped by cathodoluminescence

    SciTech Connect

    Lisitsyn, V.M.; Lyakh, G.O.; Orlovskii, V.M.; Osipov, V.V.; Urbazaev, M.N.

    1984-08-01

    Cathodoluminescence from a CdS crystal, generated by the action of high-power short-duration electron beam pulses was used to pump a rhodamine 6G (R6G) laser. Measurements were made of the energy spectrum of the electrons in the beam exciting the CdS crystal, of the cathodoluminescence spectrum of CdS, of the absorption and emission spectra of the dye, and also of the time characteristics of the cathodoluminescence and of the dye laser radiation. When the electron beam incident on the crystal was characterized by a current of 500 A and duration 8 nsec at half-height, the radiation pulses emitted by R6G had an energy of approx.1 mJ and the efficiency of generation of these pulses was approx.0.3%. OFF

  8. Squeezed light from conventionally pumped multi-level lasers

    NASA Technical Reports Server (NTRS)

    Ralph, T. C.; Savage, C. M.

    1992-01-01

    We have calculated the amplitude squeezing in the output of several conventionally pumped multi-level lasers. We present results which show that standard laser models can produce significantly squeezed outputs in certain parameter ranges.

  9. 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).

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

    SciTech Connect

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

    1999-10-01

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

  11. Tuning laser output characteristics of a pyrotechnically pumped free-running Nd:YAG laser in terms of pumping kinetics

    NASA Astrophysics Data System (ADS)

    Kang, Xiaoli; Yang, Fan; Luo, Jiangshan; Tang, Yongjian

    2015-02-01

    Using light radiation directly produced by combustion of some pyrotechnics as pumping sources of solid state lasers is a potentially effective way to obtain compact and high energy lasers. Kinetics of this kind of pumping is studied in terms of pulse energy and pulse time characteristics as well as laser output energy. Pumping kinetics is turned through changing fabrication methods of the pumping modules. It was found that the useful light energy and pulse time for the pyrotechnic pumping light showed opposite changing trend. Compressing pulse duration from 45 ms to about 10 ms would simultaneously cause 20%~ 50% decreases in useful light radiation energy. However, the laser output energy produced by these pumping sources only had a variation 9%, ranging from 427 mJ to 468 mJ. Reasons were related to the decrease in fluorescence loss in pumping energy below the threshold for the pyrotechnic modules having shorter pulse duration but higher radiation power.

  12. High Power Diode Pumped 1.06 Micron Solid State Laser

    NASA Astrophysics Data System (ADS)

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

    1989-07-01

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

  13. 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.}

  14. Single-mode operation of a long-pulse flashlamp pumped dye laser

    SciTech Connect

    Mandl, A.; Klimek, D.E.; Chou, H.P.; Litzenberger, L.; Wang, Y.

    1995-02-01

    The authors describe the achievement of single-mode operation of a flashlamp pumped long-pulse, {approximately} 700 ns dye laser, with output energy of about 350 mJ using a linear optical cavity with a ``twisted mode`` configuration. Measurements indicate that the laser frequency chirps by about 40 MHz over the entire pulse. Homodyne measurements indicate that the instantaneous bandwidth is close to the transform limit. This represents a significant advance in dye laser performance.

  15. 29-fsec pulse generation from a linear-cavity synchronously pumped dye laser

    SciTech Connect

    Kubota, H.; Kurokawa, K.; Nakazawa, M.

    1988-09-01

    29-fsec optical pulses at a center wavelength of 615 nm have been generated from a linear-cavity synchronously pumped dye laser without using the colliding-pulse mode-locking technique. The laser consists of two dye jets (a gain jet and a saturable absorber jet) and a sequence of four Brewster-angled prisms. Kiton Red S is used as the laser dye instead of the conventional Rhodamine 6G.

  16. Laser rods with undoped, flanged end-caps for end-pumped laser applications

    DOEpatents

    Meissner, H.E.; Beach, R.J.; Bibeau, C.; Sutton, S.B.; Mitchell, S.; Bass, I.; Honea, E.

    1999-08-10

    A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focused by a lens duct and passed through at least one flanged end-cap into the laser rod. 14 figs.

  17. A scalable high-energy diode-pumped solid state laser for laser-plasma interaction science and applications

    NASA Astrophysics Data System (ADS)

    De Vido, M.; Ertel, K.; Mason, P. D.; Banerjee, S.; Phillips, P. J.; Butcher, T. J.; Smith, J. M.; Shaikh, W.; Hernandez-Gomes, C.; Greenhalgh, R. J. S.; Collier, J. L.

    2016-05-01

    Laser systems efficiently generating nanosecond pules at kJ energy levels and at multi-Hz repetition rates are required in order to translate laser-plasma interactions into practical applications. We have developed a scalable, actively-cooled diode-pumped solid state laser amplifier design based on a multi-slab ceramic Yb:YAG architecture called DiPOLE (Diode-Pumped Optical Laser for Experiments) capable of meeting such requirements. We demonstrated 10.8 J, 10 Hz operation at 1030 nm using a scaled-down prototype, reaching an optical-to-optical efficiency of 22.5%. Preliminary results from a larger scale version, delivering 100 J pulse energy at 10 Hz, are also presented.

  18. Spacer and well pumping of InGaN vertical cavity semiconductor lasers with varying number of quantum wells

    NASA Astrophysics Data System (ADS)

    Debusmann, R.; Brauch, U.; Hoffmann, V.; Weyers, M.; Kneissl, M.

    2012-08-01

    We have investigated the dependence of the threshold pump power and slope efficiency of 415 nm (In)GaN vertical cavity surface emitting lasers on the wavelength of the pump source and the number of quantum wells. InGaN double quantum well resonant-periodic-gain structures with 6, 8, and 10 periods have been compared. By barrier and well pumping of the samples with a 375 nm dye laser, a nearly 10 times reduction of the laser threshold was observed compared to pumping with a 337 nm nitrogen laser source. The laser threshold was found to be independent of the number of quantum wells. The slope efficiency seems to be not affected by the pump wavelength and resonant-periodic-gain periods. The results are discussed with a rate equation model that takes into account the inhomogeneous pumping of the quantum wells and optical thickness variations in the resonant-periodic-gain structure.

  19. Nuclear-pumped lasers for large-scale applications

    SciTech Connect

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

    1989-05-01

    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 sufficiently 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 demonstrate the performance of large-scale optics and the beam quality that may be obtained; and to assess the performance of alternative designs of burst systems that increase the neutron output and burst repetition rate. 21 refs., 8 figs., 5 tabs.

  20. Airborne-mercury detection by resonant UV laser pumping.

    PubMed

    Bahns, J T; Lynds, L; Stwalley, W C; Simmons, V; Robinson, T; Bililign, S

    1997-05-15

    Optical pumping of the Hg(0) (6s (1)S(0) --> 6p (3)P(1)) transition at 253.7 nm (in air) leads to extremely fast energy transfer and strong laser-induced-fluorescence (LIF) from the Hg(0) (7s(3)S(1) --> 6p (3)P(2)) green transition at 546.2 nm, which is not directly populated by the laser. Ionization occurs simultaneously and becomes particularly strong at reduced background pressures. These observations are consistent with the existence of a multiphoton process followed by electron collisional excitation. Preliminary studies are made to evaluate these phenomena for detecting elemental airborne mercury by LIF and point monitoring with an ionization detector. Measured sensitivities of 2 and 10 parts in 10(9) (ppb), respectively, at 0.1-Torr air pressure are projected to increase to 1 x 10(-4) and 1 x 10(-5) ppb after relevant system optimization. PMID:18185642

  1. Optics and lasers: A compilation

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A number of innovative devices and techniques in optics and related fields were presented. The following areas were covered: advances in laser and holography technology, articles on spectroscopy and general optics, new information in the area of photography.

  2. Terahertz Optical Gain Based on Intersubband Transitions in Optically-Pumped Semiconductor Quantum Wells: Coherent Pumped-Probe Interactions

    NASA Technical Reports Server (NTRS)

    Liu, Ansheng; Ning, Cun-Zheng

    1999-01-01

    Terahertz optical gain due to intersubband transitions in optically-pumped semiconductor quantum wells (QW's) is calculated nonperturbatively. We solve the pump- field-induced nonequilibrium distribution function for each subband of the QW system from a set of rate equations that include both intrasubband and intersubband relaxation processes. The gain arising from population inversion and stimulated Raman processes is calculated in a unified manner. We show that the coherent pump and signal wave interactions contribute significantly to the THz gain. Because of the optical Stark effect and pump-induced population redistribution, optical gain saturation at larger pump intensities is predicted.

  3. Key techniques for space-based solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  4. Modeling of static and flowing-gas diode pumped alkali lasers

    NASA Astrophysics Data System (ADS)

    Barmashenko, Boris D.; Auslender, Ilya; Yacoby, Eyal; Waichman, Karol; Sadot, Oren; Rosenwaks, Salman

    2016-03-01

    Modeling of static and flowing-gas subsonic, transonic and supersonic Cs and K Ti:Sapphire and diode pumped alkali lasers (DPALs) is reported. A simple optical model applied to the static K and Cs lasers shows good agreement between the calculated and measured dependence of the laser power on the incident pump power. The model reproduces the observed threshold pump power in K DPAL which is much higher than that predicted by standard models of the DPAL. Scaling up flowing-gas DPALs to megawatt class power is studied using accurate three-dimensional computational fluid dynamics model, taking into account the effects of temperature rise and losses of alkali atoms due to ionization. Both the maximum achievable power and laser beam quality are estimated for Cs and K lasers. The performance of subsonic and, in particular, supersonic DPALs is compared with that of transonic, where supersonic nozzle and diffuser are spared and high power mechanical pump (needed for recovery of the gas total pressure which strongly drops in the diffuser), is not required for continuous closed cycle operation. For pumping by beams of the same rectangular cross section, comparison between end-pumping and transverse-pumping shows that the output power is not affected by the pump geometry, however, the intensity of the output laser beam in the case of transverse-pumped DPALs is strongly non-uniform in the laser beam cross section resulting in higher brightness and better beam quality in the far field for the end-pumping geometry where the intensity of the output beam is uniform.

  5. 980-nm 14-pin butterfly module dual-channel CW QW semiconductor laser for pumping

    NASA Astrophysics Data System (ADS)

    Deng, Yun; Yan, Changling; Qu, Yi; Li, Hui; Wang, Yuxia; Gao, Xin; Qiao, Zhongliang; Li, Mei; Qu, Bowen; Lu, Peng; Bo, Baoxue

    2010-10-01

    Nowadays, with its mature progress, the 790 nm - 1000 nm wavelength semiconductor laser is widely used in the fields of laser machining, laser ranging, laser radar, laser imaging, laser anti-counterfeit, biomedical and etc. Best of all, the 980 nm wavelength laser has its widespread application in the pumping source of Er3+ -doped fiber amplifier, optic fiber gyroscopes and other devices. The output wavelength of the fiber amplifier which takes the 980 nm wavelength laser as its pumping source is between 1060 nm and 1550 nm. This type of laser has its extremely wide range of applications in optical communication and other fields. Moreover, some new application domains keep constantly being developed. The semiconductor laser with the dual-channel ridge wave guide and the 980 nm emission wavelength is presented in this paper. In our work, we fabricated Lasers with the using of multi-quantum well (MQW) wafer grew by MBE, and the PL-wavelength of the MQW was 970 nm. The standard photofabrication method and the inductively coupled plasma (ICP) etching technology are adopted in the process of making dual-channel ridge wave guide with the width of 4 μm and height of 830 nm. In the state of continuous work at room temperature, the laser could output the single mode beam of 70 mW stably under the current of 100 mA. The threshold current of the laser diode is 17 mA and the slope efficiency is 0.89 W/A. The 3 dB spectrum bandwidth of the laser beam is 0.2 nm. This laser outputs its beam by a pigtail fiber on which Bragg grating for frequency stabilization is carved. The laser diode, the tail fiber, and the built-in refrigeration and monitoring modules are sealed in a 14-pin butterfly packaging. It can be used directly as the pumping source of Er3+ - doped fiber amplifier or optic fiber gyroscopes.

  6. Continuous-wave dual-wavelength operation of a diode-end-pumped Nd:GGG laser

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

    A diode-end-pumped continuous-wave (CW) simultaneous dual-wavelength laser operation at 1062 and 1331 nm in a single Nd:GGG was demonstrated. A total output power of 1.08 W at the two fundamental wavelengths was achieved at the incident pump power of 18.2 W. The optical-to-optical conversion is up to 5.9% with respect to the incident pump power. To the best of our knowledge, this is first work on CW simultaneous dual-wavelength operation of a diode pumped Nd:GGG laser. The article is published in the original.)

  7. Room-temperature diode-bar-pumped Nd:YAG laser at 946 nm

    SciTech Connect

    Clarkson, W.A.; Koch, R.; Hanna, D.C.

    1996-05-01

    Efficient, high-power operation of a diode-bar-pumped Nd:YAG laser on the quasi-three-level transition at 946 nm is reported. Longitudinal pumping of a simple folded cavity by a 20-W diode bar, with a two-mirror beam shaper used to reformat the bar{close_quote}s output, yields a continuous-wave output power at room temperature of {approximately}3W in a 1.5-times diffraction-limited beam for 13.6 W of incident pump power. The corresponding optical slope efficiency was approximately 33{percent}. {copyright} {ital 1996 Optical Society of America.}

  8. 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.

  9. Investigation of a pulsed dye laser under various pumping conditions

    SciTech Connect

    Nechaev, S.Y.

    1983-08-01

    An investigation was made of the influence of bilateral laser pumping in an almost longitudinal arrangement on the spectral and energy characteristics of a short-pulse laser utilizing rhodamine 6G. A considerable increase in efficiency over that for unilateral pumping was observed, together with a narrowing of the spectrum, in a dispersive resonator having a prism telescope and a grating.

  10. 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)

  11. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing.

    PubMed

    Wang, Weiqiang; Chu, Sai T; Little, Brent E; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  12. Dual-pump Kerr Micro-cavity Optical Frequency Comb with varying FSR spacing

    PubMed Central

    Wang, Weiqiang; Chu, Sai T.; Little, Brent E.; Pasquazi, Alessia; Wang, Yishan; Wang, Leiran; Zhang, Wenfu; Wang, Lei; Hu, Xiaohong; Wang, Guoxi; Hu, Hui; Su, Yulong; Li, Feitao; Liu, Yuanshan; Zhao, Wei

    2016-01-01

    In this paper, we demonstrate a novel dual-pump approach to generate robust optical frequency comb with varying free spectral range (FSR) spacing in a CMOS-compatible high-Q micro-ring resonator (MRR). The frequency spacing of the comb can be tuned by an integer number FSR of the MRR freely in our dual-pump scheme. The dual pumps are self-oscillated in the laser cavity loop and their wavelengths can be tuned flexibly by programming the tunable filter embedded in the cavity. By tuning the pump wavelength, broadband OFC with the bandwidth of >180 nm and the frequency-spacing varying from 6 to 46-fold FSRs is realized at a low pump power. This approach could find potential and practical applications in many areas, such as optical metrology, optical communication, and signal processing systems, for its excellent flexibility and robustness. PMID:27338250

  13. Measuring gas temperature during spin-exchange optical pumping process

    NASA Astrophysics Data System (ADS)

    Normand, E.; Jiang, C. Y.; Brown, D. R.; Robertson, L.; Crow, L.; Tong, X.

    2016-04-01

    The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.

  14. Threshold of stimulated Brillouin scattering by use of a solar pumped laser.

    PubMed

    Naftali, Nir; Benmair, Ruth M J; Pe'er, Idit; Yogev, Ammon

    2002-06-20

    What is to our knowledge the first stimulated Brillouin scattering experiment using a high-power low-gain solar pumped laser is presented. A threshold reflectivity of 0.23% was reached when a peak power of 20.7 kW was used at 7.6 GHz. A cw solar pumped laser was Q-switched with an acousto-optic modulator, and the bandwidth was narrowed with an intracavity etalon. A high polarization ratio (>99.4%) was achieved by use of an intracavity configuration. Higher reflectivity values were limited because of the lack of availability of optical switches. PMID:12078683

  15. 219.3 W CW diode-side-pumped 1123 nm Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Li, C. Y.; Bo, Y.; Xu, Y. T.; Yang, F.; Wang, Z. C.; Wang, B. S.; Xu, J. L.; Gao, H. W.; Peng, Q. J.; Cui, D. F.; Xu, Z. Y.

    2010-07-01

    We demonstrate a high power continuous wave (CW) diode-side-pumped Nd:YAG laser operating at 1123 nm with a plano-plano configuration. By means of precise coating, a single 1123 nm wavelength is achieved. Under the pump power of 1080 W, an output power of 219.3 W is obtained, which corresponds to an optical-optical conversion efficiency of 20.3%. To the best of our knowledge, this is the highest output power for CW 1123 nm laser based on Nd:YAG crystal.

  16. Role of multilayer-like interference effects on the transient optical response of Si{sub 3}N{sub 4} films pumped with free-electron laser pulses

    SciTech Connect

    Casolari, F.; Giangrisostomi, E.; Bencivenga, F.; Capotondi, F.; Manfredda, M.; Pedersoli, E.; Principi, E.; Masciovecchio, C.; Kiskinova, M.; Mincigrucci, R.

    2014-05-12

    X-ray/optical cross-correlation methods are attracting increasing interest for exploring transient states of matter using ultrashort free-electron laser (FEL) pulses. Our paper shows that in such studies the difference in the penetration depth of the FEL-pump and the infrared (IR) probe pulses become important, in particular, when exploring the changes in the optical properties of solid targets. We discuss the role of interference effects, using a phenomenological model with excited and unperturbed slabs. The reliability of this model was experimentally verified by measuring the transient optical response of free-standing and silicon (Si) supported silicon nitride (Si{sub 3}N{sub 4}) films, simultaneously in reflection and transmission, using s- and p-polarized IR light. The changes in the Si{sub 3}N{sub 4} optical refractive index, induced by the FEL pulses, have fully been described in the frame of the proposed model. The experimental results confirm that the differences, observed in the FEL-induced transient reflectance and transmittance of the Si{sub 3}N{sub 4} targets with different thicknesses, arise from multilayer-like interferometric phenomena.

  17. Reliable pump sources for high-energy class lasers

    NASA Astrophysics Data System (ADS)

    Wölz, Martin; Pietrzak, Agnieszka; Kindsvater, Alex; Wolf, Jürgen; Meusel, Jens; Hülsewede, Ralf; Sebastian, Jürgen

    2015-05-01

    High-energy class laser systems operating at high average power are destined to serve fundamental research and commercial applications. System cost is becoming decisive, and JENOPTIK supports future developments with the new range of 500 W quasi-continuous wave (QCW) laser diode bars. In response to different strategies in implementing high-energy class laser systems, pump wavelengths of 880 nm and 940 nm are available. The higher power output per chip increases array irradiance and reduces the size of the optical system, lowering system cost. Reliability testing of the 880 nm laser diode bar has shown 1 Gshots at 500 W and 300 μs pulse duration, with insignificant degradation. Parallel operation in eight-bar diode stacks permits 4 kW pulse power operation. A new high-density QCW package is under development at JENOPTIK. Cost and reliability being the design criteria, the diode stacks are made by simultaneous soldering of submounts and insulating ceramic. The new QCW stack assembly technology permits an array irradiance of 12.5 kW/cm². We present the current state of the development, including laboratory data from prototypes using the new 500 W laser diode in dense packaging.

  18. 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.

  19. 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.

  20. Excimer-pumped alkali vapor lasers: a new class of photoassociation lasers

    NASA Astrophysics Data System (ADS)

    Readle, J. D.; Wagner, C. J.; Verdeyen, J. T.; Spinka, T. M.; Carroll, D. L.; Eden, J. G.

    2010-02-01

    Excimer-pumped alkali vapor lasers (XPALs) are a new class of photoassociation lasers which take advantage of the spectrally broad absorption profiles of alkali-rare gas collision pairs. In these systems, transient alkali-rare gas molecules are photopumped from the thermal continuum to a dissociative X2Σ+ 1/2 interaction potential, subsequently populating the n2P3/2 state of the alkali. The absorption profiles >=5 nm and quantum efficiencies >98% have been observed in oscillator experiments, indicating XPAL compatibility with conventional high power laser diode arrays. An alternative technique for populating the n2P3/2 state is direct photoexcitation on the n2P3/2<--n2S1/2 atomic transition. However, because the XPAL scheme employs an off-resonant optical pump, the strengths of resonantly-enhanced nonlinear processes are minimized. Additionally, the absorption coefficient may be adjusted by altering the number densities of the lasing species and/or perturbers, a valuable asset in the design of large volume, high power lasers. We present an overview of XPAL lasers and their operation, including the characteristics of recently demonstrated systems photopumped with a pulsed dye laser. Lasing has been observed in Cs at both 894 nm and 852 nm by pumping CsAr or CsKr pairs as well as in Rb at 795 nm by pumping RbKr. These results highlight the important role of the perturbing species in determining the strength and position of the excimer absorption profile. It is expected that similar results may be obtained in other gas mixtures as similar collision pair characteristics have historically been observed in a wide variety of transient diatomic species.