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采用改进的化学气相沉积法和气相液相混合掺杂技术制备大芯径掺镱石英光纤预制棒, 以此作为有源纤芯制备了纤芯直径约90 μm的掺镱双包层光子晶体光纤, 纤芯组分为镱铝磷共掺.双包层光子晶体光纤的模场面积约1330 μm2, 纤芯数值孔径0.065,包层数值孔径0.5.首次实现了国产掺镱光子晶体光纤的高功率高效率激光输出, 1 m长的光子晶体光纤激光器实现102 W 激光输出,斜率效率76%. 相似文献
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采用改进化学汽相沉积结合溶液掺杂法制备了Yb/P/Al共掺的石英光纤预制棒,通过光纤芯层的组份和制备工艺的优化,实现了Yb3+的高浓度掺杂和均匀掺杂.预制棒芯层Yb2O3掺杂浓度达到~4wt.%,Yb3+在1 080 nm处荧光寿命为1 780μs.成功拉制出内包层截面形状为八边形的双包层光纤,纤芯直径为7.5 μm,包层吸收系数达到~5 dB/m@976 nm.利用拉制的掺镱双包层光纤开展了全光纤结构的掺镱光纤激光器性能测试实验,实现了5.15W的激光输出,斜率效率达到76%. 相似文献
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采用粉末烧结技术制备出高浓度镱铝共掺石英棒,Yb3+掺杂浓度为12 000 ppm(wt).利用此掺镱石英棒作为纤芯,拉制出镱铝共掺大模场光子晶体光纤,光纤模场面积为550μm2,模场直径26 μm.实验结果表明:光纤在近红外波段(850~1 033 nm)出现一个宽的吸收带,主吸收峰波长位于976 nm,在此波长处吸收损耗高于10 dB/m;采用波长为971 nm的激光泵浦光纤,在1 050~1 125 nm波长范围内产生高斯型的荧光峰,峰值波长位于1 088 nm处,荧光半宽高45 am. 相似文献
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采用改进的化学气相沉积法和溶液掺杂法制备出掺镱石英光纤预制棒,以该预制棒为有源纤芯制备芯区直径约为30μm的双包层保偏掺镱光子晶体光纤.模拟计算得到该保偏光纤的模场面积约232μm2,双折射系数B为5×10-5.利用该光纤分别进行了脉冲激光和连续激光的放大测试实验,在国内首次实现了高效率的飞秒激光放大,2 m长的光子晶体光纤可得到1.64 W的激光输出,激光放大斜率效率为49.8%.同时5 m长的光纤还能够实现8.12 W的连续激光放大输出,斜率效率达到55.9%,具有较高的斜率效率.此外,该光纤消光比约10 dB,具有良好的保偏特性. 相似文献
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采用粉末烧结技术制备出高浓度镱铝共掺石英棒,Yb3+掺杂浓度为12 000ppm(wt).利用此掺镱石英棒作为纤芯,拉制出镱铝共掺大模场光子晶体光纤,光纤模场面积为550μm2,模场直径26μm.实验结果表明:光纤在近红外波段(850~1 033nm)出现一个宽的吸收带,主吸收峰波长位于976nm,在此波长处吸收损耗高于10dB/m;采用波长为971nm的激光泵浦光纤,在1 050~1 125nm波长范围内产生高斯型的荧光峰,峰值波长位于1 088nm处,荧光半宽高45nm. 相似文献
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采用化学气相沉积结合气相/液相复合掺杂方式制备30/600 μm掺镱双包层光纤,石英纤芯中的掺杂组分为Yb2O3, Al2O3,P2O5。基于976 nm发光二极管反向抽运方式,构建全光纤化的主控振荡器功率放大器结构对增益光纤进行测试。实验中,种子源功率为189 W,当泵浦总功率为4747 W时,激光输出功率为4120 W,放大级光光效率为85%,3 dB带宽为1.6 nm。激光器连续工作1 h,激光功率稳定在4100 W,未发生明显的功率衰退现象。 相似文献
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A large mode area multicore photonic crystal fiber with a flattened fundamental mode is proposed in this paper. Another two kinds of single core fibers are also presented as comparison. The modal characteristics such as effective mode area and confinement loss are investigated using the finite element method. Numerical results show that a combination of flattened fundamental mode, large mode area and ultralow loss is obtained in the multicore fiber by introducing higher refractive index in the core region. 相似文献
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A novel kind of single-mode large-mode-area optical fiber is presented in this paper. The proposed fiber core is composed of high-index central rod and the surrounding multilayer rings. The mode characteristics are discussed considering the fiber structure parameters. The calculation results show that the proposed fiber possesses extreme large mode area of 2975 μm2 with single mode operation at the wavelength of 1.08 μm. Even larger mode area of the complex ring core fiber with single mode output can be achieved by coiling the fiber, due to the significant difference of bending loss between the fundamental mode and the higher-order transverse modes. Such fibers are expected to find applications in the field of fiber lasers and amplifiers. 相似文献
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Specific mode output from multimode fiber oscillators by designing rare earth doping profiles
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Based on rate equations, a theoretical model of a fiber oscillator with a multimode gain fiber was built. We studied the effect of the rare earth doping profile in the core on the output characteristics of the multimode fiber oscillator. The results indicated that a pure fundamental mode can be obtained by partly doping the core of the large mode area (LMA) ytterbium doped fiber (YDF) in the fiber laser. Furthermore, a sole specific high-order mode can also be implemented by tailoring the rare earth doping profile according to the simulations. The mode coupling effect was also taken into account in the model. In spite of the mode coupling effect, the specific mode was able to dominate in the output of the fiber laser by utilizing the designed LMA YDF. 相似文献
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Gérôme F Février S Pryamikov AD Auguste JL Jamier R Blondy JM Likhachev ME Bubnov MM Semjonov SL Dianov EM 《Optics letters》2007,32(10):1208-1210
An all-silica photonic bandgap fiber composed of a low-index core surrounded by alternating high- and low-index rings allows us to achieve a large mode area (500 microm(2)) and large chromatic dispersion. Sharp resonances from the even Bragg mode to odd ring modes theoretically lead to 20,000 ps/(nm km) chromatic dispersion when large bends are applied. By nature, sharp resonances are sensitive to inhomogeneities along the fiber length. Under experimental conditions, the resonances are broadened and the dispersion coefficient is decreased to 1000 ps/(nm km). However, to the best of our knowledge, this is the largest dispersion coefficient reported using a large mode area fiber. 相似文献
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采用Matlab和Comsol建立单模光纤内激光传输模型,对双包层内光纤折射率和纤芯结构对光能量分布的影响进行了理论研究。系统分析了光纤芯径与数值孔径、归一化频率和功率填充因子的关系,依据得到的结果进一步采用多模物理耦合仿真方法对不同类型的单模双包层光纤纤芯的能量分布进行仿真,探索了不同折射率分布情况对纤芯能量分布的影响。计算和仿真结果表明:凹面折射率分布光纤的光斑模场面积最大,单位面积的功率分布最低。针对大功率光纤激光器的应用需求设计了工作波长为1.064 m、纤芯直径为10 m、凹面直径为8 m、数值孔径为0.12的单模凹面折射率双包层光纤,为提高光纤泵浦效率、降低纤芯的能量密度提供了思路。 相似文献
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High-power all-fiber passively Q-switched laser using a doped fiber as a saturable absorber: numerical simulations 总被引:1,自引:0,他引:1
We report a design for a power-scalable all-fiber passively Q-switched laser that uses a large mode area Yb-doped fiber as a gain medium adiabatically tapered to an unpumped single-mode Yb-doped fiber, which serves as a saturable absorber. Through the use of a comprehensive numerical simulator, we demonstrate a passively Q-switched 1030 nm pulsed laser with 14 ns pulse duration and 0.5 mJ pulse energy operating at 200 kHz repetition rate. The proposed configuration has a potential for orders of magnitude of improvement in both the pulse energies and durations compared to the previously reported result. The key mechanism for this improvement relates to the ratio of the core areas between the pumped inverted large mode area gain fiber and the unpumped doped single-mode fiber. 相似文献
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在高功率密度下产生的非线性效应和材料损伤等问题限制了光纤激光器输出功率的进一步提高。利用大模场光纤降低光纤能量密度,提高非线性阈值是一种最为直接和有效的手段。以空气孔尺寸为光波长量级的全内反射型光子晶体光纤为对象,采用等效折射率模型分析了光子晶体光纤的单模特性,利用有限元法分析了结构参数对光子晶体光纤的模场面积和色散等光束质量参数的影响。设计了一种工作波长为0.40~1.55μm,模场面积为112.74~258.87μm2,且在1.27μm附近可补偿色散的大模场光子晶体光纤。该研究可为高功率光纤激光器大模场光纤的进一步参数优化设计及元件加工提供重要参考。 相似文献
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A novel fiber design of large mode area (LMA) all-glass leakage channel fibers (LCF) with triangular core is proposed. The effective single mode behavior and bend characteristics of the fiber are numerically investigated. The designed LCFs can achieve LMA larger than 1400 μm2, effective single mode operation and low bend loss by carefully choosing the diameters of the fluorine-doped silica rods. 相似文献