The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Hajime Shoji - One of the best experts on this subject based on the ideXlab platform.
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effect of phonon bottleneck on quantum dot Laser Performance
Applied Physics Letters, 1997Co-Authors: Mitsuru Sugawara, Kohki Mukai, Hajime ShojiAbstract:The effect of phonon bottleneck on quantum-dot Laser Performance is examined by solving the carrier-photon rate equations including the carrier relaxation process into the quantum-dot ground state. We show that the retarded carrier relaxation due to phonon bottleneck degrades the threshold current and the external quantum efficiency. We also show that quantum-dot Lasers are quite sensitive to the crystal quality outside as well as inside quantum dots. Our results clarified that the relaxation lifetime should be less than about 10 ps to fully utilize the Laser potential originating from the quantum-dot discrete energy states.
Huaijin Zhang - One of the best experts on this subject based on the ideXlab platform.
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Continuous-wave and passive Q-switching Laser Performance of Yb:YSGG crystal
Optics Express, 2014Co-Authors: Xiaowen Chen, Shuxian Wang, Huaijin ZhangAbstract:We report, for the first time, on the passive Q-switching Laser Performance of Yb:YSGG disordered garnet crystal. An average output power of 2.6 W at 1025.8 nm was produced at a pulse repetition rate of 11 kHz with a slope efficiency of 47%; the resulting pulse energy, duration, and peak power were respectively 236 μJ, 3.6 ns and 65.6 kW. The Laser Performance in continuous-wave mode under 935-nm diode pumping was also investigated, with output coupling changed over a wide range from 0.5% to 60%.
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Continuous-wave Laser Performance of Tm:LuVO4 under Ti:sapphire Laser pumping
Advanced Solid-State Lasers Congress, 2013Co-Authors: Fabrizio Di Trapani, Huaijin Zhang, Xavier Mateos, Valentin Petrov, Antonio Agnesi, Uwe Griebner, Jiyang Wang, Haohai YuAbstract:We investigate the cw Laser Performance of Tm:LuVO4 crystals pumped with tunable polarized source and report roughly 2 times improvement of the efficiency with 1 W of output power and broad tunability at room temperature.
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Passive Q-switching Laser Performance of Yb:Gd3Ga5O12 garnet crystal.
Applied Optics, 2013Co-Authors: Hongying Yi, Kui Wu, Huaijin ZhangAbstract:We report on the passive Q-switching Laser Performance of the Yb:Gd3Ga5O12 garnet crystal. With a Cr4+:YAG crystal used as saturable absorber for passive Q-switching, an average output power of 5.31 W was produced at a pulse repetition rate of 62.5 kHz, the optical-to-optical and slope efficiencies being, respectively, 45% and 61%. Laser pulses of 140 μJ in energy and 5.8 ns in duration were also obtained at 22.2 kHz, with a corresponding peak power amounting to 24.1 kW.
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Improvement in continuous-wave Laser Performance of disordered Yb:CNGG crystal
Applied Optics, 2012Co-Authors: Zhichao Zhou, Xueping Tian, Jiayin Huang, Huaijin ZhangAbstract:We report on a significant improvement in cw Laser Performance of the disordered Yb:CNGG crystal. Very efficient cw Laser operation is demonstrated at room temperature with a 3.5 mm thick crystal end pumped by a diode Laser, generating an output power of 5.15 W with an optical-to-optical efficiency of 46%, whereas the slope efficiency amounts to 80%.
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Spectroscopic properties and Laser Performance of a new mixed Yb0.015:Lu0.162Gd0.823VO4 crystal
Laser Physics Letters, 2012Co-Authors: W. Kong, Huaijin Zhang, Xavier Mateos, Valentin PetrovAbstract:Spectroscopic properties and continuous-wave Laser Performance of a new Yb0.015:Lu0.162Gd0.823VO4 mixed vanadate crystal are reported. An appreciable discontinuous increase in output power occurs during the σ- to π-polarization switching process in the Laser oscillation. A maximum output power of 4.3 W is generated with an optical-to-optical efficiency of 46%, whereas the average slope efficiency is determined to be 73 – 77%, depending on the output coupling utilized.
Mitsuru Sugawara - One of the best experts on this subject based on the ideXlab platform.
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Effect of carrier dynamics on quantum-dot Laser Performance
Conference Proceedings. 1998 International Conference on Indium Phosphide and Related Materials (Cat. No.98CH36129), 1998Co-Authors: Mitsuru SugawaraAbstract:The purpose of this work is to study the effect of carrier dynamics on quantum-dot Laser Performance. The simulation using carrier-photon rate equations clarifies criteria on the carrier relaxation lifetime as well as the inhomogeneous broadening linewidth and the crystal quality to achieve high-Performance. The relaxation lifetime forms a hierarchy in quantum-dot Lasers, i.e., what Performance we can expect strongly depends on the relaxation lifetime.
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effect of phonon bottleneck on quantum dot Laser Performance
Applied Physics Letters, 1997Co-Authors: Mitsuru Sugawara, Kohki Mukai, Hajime ShojiAbstract:The effect of phonon bottleneck on quantum-dot Laser Performance is examined by solving the carrier-photon rate equations including the carrier relaxation process into the quantum-dot ground state. We show that the retarded carrier relaxation due to phonon bottleneck degrades the threshold current and the external quantum efficiency. We also show that quantum-dot Lasers are quite sensitive to the crystal quality outside as well as inside quantum dots. Our results clarified that the relaxation lifetime should be less than about 10 ps to fully utilize the Laser potential originating from the quantum-dot discrete energy states.
James A. Piper - One of the best experts on this subject based on the ideXlab platform.
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Spectral properties and infrared Laser Performance of diode-pumped Yb:YAl3(BO3)4
Advanced Solid State Lasers, 2020Co-Authors: Pu Wang, Judith M. Dawes, Peter Dekker, James A. PiperAbstract:Infrared Laser Performance of the novel Laser crystal Yb:YAl3(BO3)4, pumped by a 1.6W fibre-coupled 975nm diode, is reported. The maximum output power at 1040nm was 654mW and the threshold 123mW. Slope efficiencies as high as 71% and optical-optical conversion efficiencies of 53% were obtained. The spectral and Laser properties of this crystal are comparable with other ytterbium Laser materials including Yb:YAG.
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Investigation of blue emission from Raman-active crystals: Its origin and impact on Laser Performance
Optical Materials Express, 2014Co-Authors: Jonas Jakutis Neto, James A. Piper, Christopher Artlett, David J. Spence, Niklaus Ursus Wetter, Helen M. PaskAbstract:The origin and consequences to Laser Performance of blue emission observed in some Raman crystals has been studied in detail, leading us to attribute the origin of the phenomenon to fluorescence from Tm3+(1G4) impurity ions which are excited via sequential upconversion. For the specific case of a Nd:YLF/KGW Raman Laser, we show that the blue fluorescence has modest but significant impacts on Laser Performance and thermal loading. If the blue fluorescence was eliminated, then Laser efficiency could be increased by 15% and thermal loading in the KGW crystal reduced by 17%.
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The Effects of Impurities on Metal Vapour Laser Performance
Pulsed Metal Vapour Lasers, 1996Co-Authors: D.j.w. Brown, Michael J. Withford, Rich Mildren, James A. PiperAbstract:Trace levels of volatile or metallic impurities can dramatically affect metal vapour Laser Performance. We report a detailed investigation of impurity effects, with emphasis on characterizing and explaining the beneficial influence of hydrogen additives on output power, repetition rate scaling, and high beam quality extraction from CVLs.
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Investigation of the effects of hydrogen and deuterium on copper vapour Laser Performance
Optics Communications, 1994Co-Authors: Michael J. Withford, Daniel J. W. Brown, James A. PiperAbstract:Abstract We report a detailed study of the effects on copper vapour Laser Performance of the addition of small partial pressures of gaseous hydrogen, deuterium and other trace gases to the neon buffer gas. Increases in output power by typically 30% are observed for a small-scale (6 W) device and the spatial characteristics of the output beam are significantly altered. Increased power deposition due to improved impedance matching is shown to be a minor effect. Instead, the changes to output power and the voltage/current characteristics during the excitation pulse and the interpulse period are attributed primarily to enhanced plasma cooling by elastic interactions resulting in reduced prepulse electron densities.
Jun Dong - One of the best experts on this subject based on the ideXlab platform.
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Effect of Polarization States on the Laser Performance of Passively $Q$ -switched Yb:YAG/Cr,Ca:YAG Microchip Lasers
IEEE Journal of Quantum Electronics, 2020Co-Authors: Jun Dong, Ken-ichi Ueda, Hideki Yagi, A. A. KaminskiiAbstract:The polarization states of passively Q-switched microchip Lasers were investigated by adopting different combinations of Yb:YAG, Cr,Ca:YAG crystals and ceramics. The results show that except for the random polarization oscillation of Yb:YAG/Cr,Ca:YAG all-ceramics combination, other three combinations including crystals exhibit linearly polarization. Highly efficient, nearly diffraction-limited beam quality, high peak power, sub-nanosecond passively Q-switched Lasers were obtained for all combinations of Yb:YAG, Cr,Ca:YAG ceramics and crystals. The best Laser Performance was obtained with Yb:YAG/Cr,Ca:YAG crystals combination. The effect of polarization states on the Laser Performance was also addressed.
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Concentration-dependent Laser Performance of Yb:YAG ceramics
2008 Conference on Lasers and Electro-Optics, 2008Co-Authors: Jun Dong, Ken-ichi Ueda, Hideki YagiAbstract:Laser Performance of Yb:YAG ceramics and single-crystals doped with different Yb concentrations was investigated using two-pass pumping miniature Laser configuration. Better Laser Performance was observed for heavy-doped Yb:YAG ceramic than single-crystal (CYb = 20 at.%).
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Effect of ytterbium concentration on cw Yb:YAG microchip Laser Performance at ambient temperature – Part I: Experiments
Applied Physics B, 2007Co-Authors: Jun Dong, Ken-ichi Ueda, Akira Shirakawa, A. A. KaminskiiAbstract:The microchip Laser Performance of Yb:YAG crystals doped with different ytterbium concentrations (CYb=10, 15, and 20 at. %) has been investigated at ambient temperature without active cooling of the gain media. Efficient Laser oscillation for a 1-mm-thick YAG doped with 10 at. % Yb3+ ions was achieved at 1030 and 1049 nm with slope efficiencies of 85% and 81%, correspondingly. The Laser Performance of heavy-doped Yb:YAG crystals was limited by the thermal population at terminated lasing level and thermal lens effect at room temperature without sufficient cooling of the samples. The Laser emitting spectra of Yb:YAG microchip Lasers with different Yb concentrations and output couplings are addressed with the local temperature rise, due to the absorption of the pump power inside the gain media under different pump levels.
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Effect of ytterbium concentration on Yb:YAG microchip Laser Performance at ambient temperature
2007 Conference on Lasers and Electro-Optics - Pacific Rim, 2007Co-Authors: Jun Dong, Ken-ichi Ueda, Akira Shirakawa, A. A. KaminskiiAbstract:The microchip Laser Performance of Yb:YAG crystals doped with different ytterbium concentrations (10, 15, and 20 at.%) has been investigated at ambient temperature. Efficient Laser oscillation for 1-mm-thick YAG doped with 10 at.% Yb3+ ions was achieved at 1030 and 1049 nm with slope efficiencies of 85 and 81%, correspondingly.
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Efficient Dual-wavelength Laser Performance of Yb:YAG Crystal Grown by Temperature Gradient Technique
Advanced Solid-State Photonics, 2006Co-Authors: Jun Dong, Ken-ichi Ueda, Akira Shirakawa, Jun Xu, Peizhen DengAbstract:Efficient dual-wavelength Laser Performance of Yb:YAG crystal grown by temperature gradient technique was achieved at room temperature. Slope efficiencies of 57%, 68% at 1049 nm and 1030 nm were achieved for 10 at.% Yb:YAG sample.
