共查询到20条相似文献,搜索用时 62 毫秒
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报道了一种基于电光-可饱和吸收主被动双调Q技术的窄脉冲宽度、高峰值功率946nm全固态激光器.该激光器采用808nm脉冲半导体激光侧面泵浦长尺寸Nd∶YAG晶体棒抽运方式和双凹型折叠谐振腔结构,并将横向加压式的双45°角切割掺氧化镁铌酸锂晶体电光调Q与单层二硒化钼被动可饱和吸收调Q相结合,通过优化设计谐振腔结构,在脉冲重复频率550 Hz时,获得了最大单脉冲能量3.15mJ、脉冲宽度9.1ns、峰值功率高达346kW的946nm主被动双调Q脉冲激光的稳定输出,脉冲宽度和能量的峰峰值不稳定度分别达到±2.87%和±3.42%,光束质量因子分别为M_x~2=3.851和M_y~2=3.870. 相似文献
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利用种子诱导生长法制备了长径比为5的金纳米棒,测量了它的吸收谱,结果表明该纳米棒具有较宽的吸收带(800~1 600 nm)。进一步测量了它的非线性吸收性质,结果表明它在1.56 μm波长处具有可饱和吸收特性,有望被用于实现被动调Q脉冲激光的输出。将该可饱和吸收体置于掺铒光纤激光器腔内,当泵浦功率增至30 mW时开始有稳定的调Q脉冲激光输出,输出激光的工作波长为1.56 μm。当泵浦功率为205 mW时,可获得的最大输出功率约6.9 mW,脉冲能量达219 nJ。研究结果表明,这种新型可饱和吸收体在脉冲激光领域具有广阔的应用前景。 相似文献
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利用可饱和吸收半导体GaAs作为被动调Q元件和FP输出耦合镜,实现了半导体激光器(LD)抽运Nd:YVO4激光调Q运转,获得脉宽度为47ns,重复频率为1183kHz,平均功率为430mW,光束质量为M2=113的TEM00激光基横模输出,调Q抽运阈值为1700mW.并数值求解了含有GaAs被动调Q兼输出耦合的速率方程,分析了GaAs被动调Q机理以及脉宽宽度、重复频率、平均功率随抽运速率、腔长的变化关系,理论与实验结果相一致.为多功能综合型微型调Q固体激光器提供了简单有效的方法.
关键词:
被动调Q
输出耦合
GaAs 相似文献
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利用可饱和吸收半导体GaAs作为被动调Q元件和F-P输出耦合镜,实现了半导体激光器(LD)抽运Nd:YVO4激光调Q运转,获得脉宽度为47ns,重复频率为1183kHz,平均功率为430 mW,光束质量为M2=1.13的TEM00激光基横模输出,调Q抽运阈值为1700mW.并数值求解了含有GaAs被动调Q兼输出耦合的速率方程,分析了GaAs被动调Q机理以及脉宽宽度、重复频率、平均功率随抽运速率、腔长的变化关系,理论与实验结果相一致.为多功能综合型微型调Q固体激光器提供了简单有效的方法. 相似文献
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利用固体可饱和吸收体砷化镓(GaAs)作为被动调Q元件,实现了激光二极管抽运平-凹腔掺钕钒酸钇(Nd:YVO4)激光调Q运转,详细测量了砷化镓被动调QNd:YVO4激光输出特性,获得脉宽15ns,重复频率470kHz,光束质量M^2=1.31的激光输出,调Q激光运转阈值为500mW,并数值求解了砷化镓被动调Q速率方程,讨论了被动调Q机理以及调Q脉冲宽度和脉冲重复频率对抽运速率的依赖关系,理论计算结果与实验结果相一致。 相似文献
11.
Benjamin Grinstein 《Nuclear Physics B》1992,380(3):369-376
The decay constants for D and Ds mesons, denoted fD and fDS respectively, are equal in the SU(3)V limit, as are the hadronic amplitudes for
and
mixing. The leading SU(3)V violating contribution to (FDS/FD) and to the ration of hadronic matrix elements relevant for
and
mixing amplitudes are calculated in chiral perturbatiion theory. We discuss the formalism needed to include both meson and anti-meson fields in the heavy quark effective theory. 相似文献
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We present techniques which enable one to calculate quickly the amplitudes for many scattering processes in the high-energy limit. As an illustration of the method, these are applied to the diagrams for , where V = W± or Z0. The form of the results lends itself to immediate numerical evaluation. 相似文献
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The branching ratio is calculated for Λ8Li decay to the (2+) 8Be1 states near 17 MeV, using intermediate coupling wave functions for Λ8Li and for the relevant 8Be1 states. It is pointed out that this ratio is sensitive primarily to a mixing angle ? in the Λ8Li wave function. Within one standard deviation, the data allow two ranges (+0.05 to +0.25 rad and +1.10 to +1.25 rad) for the value of ?. The further requirement that there also be acceptable agreement between the angular distribution expected for the subsequent decay and the data, shifts these allowed ranges for ?, to (+0.13 to 0.40) rad and (+0.9 to +1.2) rad. It is predicted that the dominant transition should be to 8Be1 (16.6 MeV), as is observed to be the case, rather than to 8Be1 (16.9 MeV). The interpretation of these values for ? is discussed in some detail and their implications for intermediate coupling shell-model calculations of Λ-hypernuclear wave functions are considered. 相似文献
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N.A. Narasimham K.V.S.R. Apparao T.K. Balasubramanian 《Journal of Molecular Spectroscopy》1976,59(2):244-254
Vibrational and rotational analyses of the near-infrared bands of S2 lying in the region 7440–8085 Å are reported. They form a new band system involving a transition and arise from the same initial 3Πgi state of the 3Πgi-3Δui band system reported earlier. The analyses of the bands of this system due to the isotopic molecules 32S34S and 34S2 are also reported. 相似文献
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N.B. Manson J.T. Gourley E.R. Vance D. Sengupta G. Smith 《Journal of Physics and Chemistry of Solids》1976,37(12):1145-1148
At helium temperatures two sharp lines at 9350 and 9510 cm?1 have been observed for the first tune on the low-energy side of the broad double-peaked absorption corresponding to the transition in Fe2+ at the octahedral site in MgO. The lower energy line has a half width of 4 cm?1; Zeeman measurements show that it is of magnetic dipole origin. The Zeeman spectra are consistent with those expected for a pure electronic transition from the (5T2g)T2g ground state to the 5Eg excited state. The second line, with a halfwidth of ~ 35 cm?1, a vibrational sideband. 相似文献
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Most studies on Co-doped TiO2 system were focused on thin films grown by MBE-based methods. In this work we report the ferromagnetism of nanometer-thick-layered TiO2/Co/TiO2/TiN film grown on Si substrate by conventional magnetron sputtering. For the growth of TiO2 on silicon, a non-oxide thermally stable material, TiN, was introduced to prevent Ti penetration into the Si substrate. Structural, magnetic, and transport measurements respectively by Raman, SQUID and Hall effect show that our samples are n-type semiconductors and exchange bias effect due to exchange coupling between Co and interfacial CoO. For the rapid vacuum annealed specimen, we found an enhanced loss and a Perminvar-type constricted hysteresis loop, which attributed to pinning of domain walls due to an induced anisotropy by the pair ordering in the metallic alloy of Co-Ti-Si. 相似文献
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N. Mamouni M. Belaiche A. Benyoussef A. El Kenz H. Ez-Zahraouy M. Loulidi E. H. Saidi E. K. Hlil 《中国物理 B》2011,20(8):87504-087504
Electronic and magnetic structures of zinc blende ZnO doped with V impurities are studied by first-principles calculations based on the Korringa-Kohn-Rostoker (KKR) method combined with the coherent potential approximation (CPA).Calculations for the substitution of O by N or P are performed and the magnetic moment is found to be sensitive to the N or P content.Furthermore,the system exhibits a half-metallic band structure accompanied by the broadening of vanadium bands.The mechanism responsible for ferromagnetism is also discussed and the stability of the ferromagnetic state compared with that of the paramagnetic state is systematically investigated by calculating the total energy difference between them by using supercell method. 相似文献
18.
D. Ziemińska 《Nuclear Physics A》1975,242(3):461-466
The branching ratios are calculated for 11ΛB decay to the 11C ground and excited states below 8 MeV for two possible spin values of 11ΛB. It is found that the decay rate to the 11C★ state at E★ = 6.48 MeV is comparable in magnitude to that leading to the 11C ground state if is assumed. This result, unlike the branching ratios calculated for the case, is in accord with experiment and lends support to the assumption that holds for 11ΛB. The necessity of the reinterpretation of some of the so-called 13ΛC events in terms of is indicated. 相似文献
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Lifetimes of 24 different levels (v′, J′) in the B1Πu state of Na2 have been measured with an accuracy of about 1% using a modelocked Ar+ laser and a modified delayed coincidence single-photon counting technique. With these lifetimes, the variation of the transition moment R(r) with internuclear distance r has been determined. The necessary Franck-Condon factors and r centroids have been calculated from spectroscopic data obtained by previous interferometric measurements of laser-induced fluorescence. The squared transition moment |R(r)|2 increases between and by about 30%. Our measurements confirm the results of M. M. Hessel, E. W. Smith, and R. E. Drullinger, who used intensity measurements of Na2 fluorescence lines for the determination of R(r). 相似文献