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采用角度磨抛的方式, 在纤芯/包层为20/400 μm双包层掺Yb光纤上制作了侧面抽运耦合器. 该耦合器对975 nm的半导体二极管抽运光的耦合效率最高可达97%, 对1080 nm信号光的泄漏比小于2%. 分析了侧面抽运耦合器的性能以及多个侧面抽运耦合器的级联分布对抽运耦合效率的影响; 同时, 在前向抽运和双向抽运方式下, 分析了级联耦合器的分布及信号光泄漏比对激光器整体效率的影响, 并进行了数值模拟. 采用自行研制的侧面抽运耦合器, 搭建了侧面耦合分布式抽运、掺Yb双包层全光纤主振荡功率放大器, 获得了波长为1080 nm、功率为303 W 的基模激光输出. 进一步增加抽运点个数, 提高抽运功率, 可获得更高的输出功率. 相似文献
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Photoelectric Property Improvement of 1.0-eV GaInNAs and Applications in Lattice-Matched Five-Junction Solar Cells 下载免费PDF全文
GaInNAs with bandgap 1.0 eV is a promising material for multi-junction solar cell applications. However, the poor quality of GaInNAs grown by metalorganic chemical vapor deposition hinders its device performance. Here to reap the benefits of 1.0-eV sub-cell, we focus on the optimization of annealing temperature and growth ambient of GaInNAs. The GaInNAs sub-cell exhibits a concentration reduction of shallow level defects when it is annealed at 700℃ for 20 min. As compared with the growth case using a hydrogen ambient, the N incorporation efficiency of GaInNAs can be enhanced during the growth in an N_2 ambient. Furthermore, background carbon concentration is observed to reduce in the as-grown GaInNAs epilayer. A GaInNAs sub-cell with 82% peak external quantum efficiency is obtained in a dual-junction GaInNAs/Ge solar cell. Finally, a monolithic Al Ga In P/Al Ga In As/Ga In As/GaInNAs/Ge five-junction solar cell is grown for space application. The fabricated device shows a conversion efficiency of 31.09% and a short-circuit current density of 11.81 m A/cm~2 under 1 sun AM 0 illumination. 相似文献
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多波长半导体激光阵列端泵Nd:YAG脉冲激光器 总被引:1,自引:1,他引:0
研制了无温控多波长激光二极管阵列端面泵浦Nd:YAG电光调Q激光器。采用4 000 W多波长准连续激光二极管阵列作为泵浦源,快轴准直镜与透镜导管作为泵浦耦合系统,端面泵浦φ6 mm×60 mm的Nd:YAG晶体,并采用RTP晶体进行电光调Q实验。在重复频率5 Hz、室温(25℃)时,激光器获得了最大输出能量74.4 mJ、脉宽15 ns的1 064 nm脉冲激光输出,光光转换效率达到11%。在25~55℃的工作温度下,对多波长LDA的光谱特征与激光器的输出特性作了测试,激光器输出能量随着工作温度的上升而先迅速下降再逐步保持稳定,当重复频率分别为5 Hz和10 Hz时,激光器对应的最低输出能量分别为48 mJ与37 mJ。 相似文献
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Many experimental investigations on the temperature dependence of the refractive index of optical fibers have been reported previously, however a satisfying theoretical explanation for it is still absent. In this paper, a theoretical model about the temperature dependence of the refractive index of optical fibers is presented and it is in agreement with the previous experimental results. This work is a significant reference for the research and development of temperature sensors based on optical fiber delay lines. 相似文献
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随着单管半导体激光器光纤耦合技术的不断发展,为了进一步提高多单管半导体激光器的输出功率,本文采用曲面空间排列方式对多个单管半导体激光器进行合束研究,使更多数量的单管半导体激光器耦合进入同一光纤中,获得更高的输出功率。文中利用ZEMAX光学设计软件进行仿真模拟,将34只波长为975 nm、输出功率为10 W的单管半导体激光器合束聚焦后耦合进芯径200 μm、数值孔径0.22的光纤中,获得耦合效率91.76%、输出功率312.03 W的激光系统。实验中,将17只单管半导体激光器耦合进芯径200 μm、数值孔径0.22的光纤中,在10.5 A的驱动电流下,输出功率为100.5 W,系统耦合效率为68.46%。 相似文献
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为了压缩MOPA全光纤调Q激光器脉冲宽度,对谐振腔基本参数进行了研究。首先,根据速率方程理论推导出脉冲宽度的表达式,通过数值解建立表达式参数与脉冲宽度的关系。然后,分析增益光纤长度、腔镜输出透过率、Q开关性能等谐振腔基本参数对全光纤调Q种子源输出脉冲宽度的影响并通过实验来逐一验证结果。最后,通过优化的参数搭建全光纤调Q激光器,在重复频率为20 kHz时,得到脉冲宽度为54 ns、平均功率为0.86 W的种子激光输出。在重复频率为100 kHz时,对脉宽142 ns、平均功率为1.66 W的种子光进行预放大和功率主放大,最终得到平均功率120 W、脉宽180 ns、光谱宽度为0.67 nm的稳定脉冲激光输出。通过提升AOM性能、减小增益光纤长度等参数优化方式构建调Q光纤激光器,能有效压缩谐振腔内脉冲宽度。 相似文献
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Traditionally, the theory related to the spatial angular momentum has been studied
completely, while the investigation in the generator of Lorentz boost is inadequate.
This paper shows that the generator of Lorentz boost has a nontrivial physical
significance: it endows a charged system with an electric moment, and has an
important significance for the electrical manipulations of electron spin in
spintronics. An alternative treatment and interpretation for the traditional Darwin
term and spin--orbit coupling are given. 相似文献