排序方式: 共有14条查询结果,搜索用时 15 毫秒
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通过CO2激光器熔融不同直径的熔锥光纤以得到相应直径的石英玻璃微球,利用此微球和熔锥光纤,构造了球微腔耦合系统。实验中利用光腰直径为3.1μm的熔锥光纤与直径为143.1μm的石英玻璃微球进行耦合,通过最大分辨力为1pm的可调谐半导体激光器对该耦合系统进行光谱扫描,发现石英玻璃微球的吸收光谱中出现分立的结构共振峰。利用光学微球腔理论讨论了石英玻璃微球吸收光谱中的结构共振,并用米氏散射理论公式对一阶TE模共振峰的位置以及它们的间隔进行了计算,共振峰位置实验结果与理论结果的误差仅为0.03%,表明实验与计算结果相符。 相似文献
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级联掺磷光纤喇曼激光器的解析优化 总被引:1,自引:0,他引:1
讨论了二级级联喇曼光纤激光器的解析解和优化设计.通过引入几何平均功率、增益因子和归一化光纤有效长度,将描述泵浦光和斯托克斯光沿喇曼增益光纤分布的微分方程组简化成代数方程组,在对泵浦光采用线性传播近似后,获得了二级级联喇曼激光器的解析解.所获得的解析解同数值模拟结果吻合得很好.利用该解析解可方便和快速地讨论级联喇曼激光器的优化设计,计算不同泵浦功率下的最佳光纤长度、输出光纤光栅反射率和转换效率.泵谱功率越大,最佳光纤长度越短,最佳输出光纤光栅反射率越小. 相似文献
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在大数据时代,入侵检测作为网络安全的一种重要技术手段被广泛采用.网络入侵检测数据不同的特征属性具有不同的量纲和量纲单位,为了消除特征属性之间的量纲影响,一般在进行数据分析之前采用归一化处理.当前网络入侵检测数据的归一化处理大多只考虑特征属性取值本身的分布情况,没有客观地评估它对类别信息或其他特征属性的影响.针对这个问题,提出了一种基于信息论的网络入侵检测数据归一化方法.对连续特征属性,它以联合信息增益作为区间的分割评估方法,以区间的类别占比作为标准依据进行归一化处理;对离散特征属性,它根据类别条件熵的占比进行了归一化处理.利用NSL-KDD数据集仿真实验,结果表明,该方法不仅能够提高学习算法的收敛性,而且归一化的结果有助于提高分类模型的检测率和降低分类模型的误报率. 相似文献
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Highly efficient cascaded P-doped Raman fiber laser pumped by Nd:YVO4 solid-state laser 总被引:1,自引:0,他引:1
A highly efficient cascaded P-doped Raman fiber laser (RFL) pumped by a 1064-nm continuous wave (CW) Nd:YVO4 solid-state laser is reported. 1.15-W CW output power at 1484 nm is obtained while the input pump power is 4 W, corresponding to the power conversion efficiency of 28.8%. The threshold pump power for the second-order Stokes radiation is 1.13 W. The slope efficiency is as high as 42.6%. The experimental results are in good agreement with theoretical ones. Furthermore, the power instability of the P-doped RFL at 1484 nm in an hour is observed to be less than 5%. 相似文献
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We investigate the characteristics of the dual-forward synchronously pumped L-band erbium-doped su- perfiuorescent fiber source (SFS). The effects of pump ratio and fiber length arrangements on the output characteristics of the L-band SFS in terms of mean wavelength, spectral linewidth, and output power are analyzed. It is shown that the optimized pump ratio and fiber length arrangements provide broadening spectral linewidth and enhanced pumping efficiency, while the synchronous pump ensures stable mean wavelength operation. A new single-forward pumping scheme with a section of unpumped fiber is pro- posed to achieve a mean wavelength stable L-band SFS with a broadening linewidth of 50.4 nm and a pumping efficiency of 33.5%. 相似文献
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The direct generation of passively Q-switched lasers at a green wavelength has rarely been investigated in the past. In this Letter, we demonstrate a passively Q-switched praseodymium-doped yttrium lithium fluoride green laser at 522 nm using CdTe/CdS quantum dots as a saturable absorber. A maximum average output power of 33.6 m W is achieved with the shortest pulse width of 840 ns. The corresponding pulse energy and peak power reached 0.18 μJ and 0.21 W, respectively. To the best of our knowledge, this is the first demonstration in regard to a quantum dots saturable absorber operating in the green spectral region. 相似文献