排序方式: 共有41条查询结果,搜索用时 15 毫秒
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Analysis of tunable picosecond pulse generation from a distributed feedback Ti:sapphire laser 下载免费PDF全文
A distributed feedback Ti:sapphire laser (DFTL) pumped by a 532nm Q-switched pulse is proposed for the generation of tunable picosecond pulses. With coupled rate equation model, the temporal characteristics of DFTL are obtained. The numerical solutions show that the DFTL pulse with a 50-ps pulse duration and as much as 3.SmJ pulse energy can be obtained under 40-m J, 5-ns pulse pumping. The dependence of output pulse width on the laser crystal‘s length, pumping pulse duration, and pumping rate is also discussed in detail. 相似文献
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Yb,Er:YAG中能量上转换过程研究 总被引:4,自引:0,他引:4
计算了Yb,Er:YAG晶体中Yb^3 和Er^3 离子之间交叉弛豫几率,分析了Yb,Er:YAG晶体中能量上转换过程.通过求解跃迁速率方程,得出了Yb^3 和Er^3 离子的最佳掺杂浓度. 相似文献
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Guided mode resonance in planar metamaterials consisting of two ring resonators with different sizes 下载免费PDF全文
We proposed and experimentally investigated a two-ring-resonator composed planar hybrid metamaterial(MM), in which the spectra of guided mode resonance(GMR) and Fano resonance or EIT-like response induced by coherent interaction between MM resonance and GMR can be easily controlled by the size of the two rings in the terahertz regime.Furthermore, a four-ring-resonator composed MM for polarization-insensitive GMRs was demonstrated, where GMRs of both TE and TM modes are physically attributed to the diffraction coupling by two ±45° tilting gratings. Such kind of device has great potential in ultra-sensitive label-free sensors, filters, or slow light based devices. 相似文献
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硫代巴比妥酸是目前多晶型种类较丰富的一类固体药物。利用太赫兹时域光谱(THz-TDS)技术对硫代巴比妥酸晶型Ⅰ,Ⅱ,Ⅲ,Ⅳ和水合晶型进行表征分析,得到明显不同的太赫兹光谱,表明THz光谱技术可以有效鉴别硫代巴比妥酸不同类多晶型。硫代巴比妥酸晶型Ⅳ为异构多晶型,它在0.65 THz处的宽峰以及1.02,1.41 THz处的吸收峰明显区别于晶型Ⅰ和Ⅱ简单的物理混合。运用密度泛函理论(DFT)对硫代巴比妥酸晶型Ⅳ的两种可能结构进行了分子结构优化和光谱模拟,模拟结果显示其中的结构a在0.41/0.47,0.89和1.35 THz处具有吸收峰,与实验结果较吻合。由此推断晶型Ⅳ由硫代巴比妥酸异构体A的硫酮键中的S7和异构体B酰胺中的H23构成第一处氢键,异构体B硫酮键中的S20和异构体A酰胺中的H13形成第二处氢键。本文还结合理论模拟结果对硫代巴比妥酸晶型Ⅳ的振动模式进行归属。 相似文献
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From transition-rate-equations and transmission-equations the formulas of threshold power and slope efficiency of an end-pumped laser for a four-level system are deduced. Citing the laser of Er:YAG as an example, we have discussed the differences of laser output characteristics between the three-and four-level systems. 相似文献
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We propose and experimentally demonstrate a high quality(Q)-factor all-silicon bound state in the continuum(BIC) metasurface with an imperforated air-hole array. The metasurface supports two polarization-insensitive BICs originated from guided mode resonances(GMRs) in the frequency range of 0.4 to 0.6 THz, and the measured Q-factors of the two GMRs are as high as 334 and 152, respectively. In addition, the influence of the thickness of the silicon substrate on the two resonances is analyzed in d... 相似文献
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硝基呋喃是一种广谱抗生素,其衍生物应用广泛;但摄入过量,会发生溶血性贫血、急性肝坏死等疾病。传统检测方法样品用量大、检测时间长且过程复杂;超表面传感器检测方法样品用量小且检测快速、简单方便。提出一种基于对称开口环的太赫兹超表面微结构器件,该结构折射率灵敏度达到196 GHz/RIU,可应用于高灵敏度传感检测。利用该超表面传感器对两种不同质量浓度的呋喃唑酮和呋喃妥因溶液进行痕量实验检测,结果表明,该超表面传感器对两种药物的最低检测质量浓度达到10 mg/dL,有望应用于生物医学等领域样品的传感检测。 相似文献