共查询到18条相似文献,搜索用时 140 毫秒
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激光多模式毛细管电泳检测器的光学设计及优化 总被引:2,自引:2,他引:0
提出一种基于毛细管电泳的激光多模式检测器.为设计并优化其光路构型,进行了理论分析和数学推导,并采用Matlab仿真,得到光路中各参量优化取值范围.在热透镜通道,激发光束腰半径越小,则热透镜效应越强.而探测激光束腰半径、束腰与样品距离、样品与探测面距离三个参量综合决定检出信号强度;在回射干涉通道,聚焦透镜焦距应较短,它与毛细管距离对检测影响很大,而与激光器、与探测面的两距离对检测影响相对较小;热透镜效应对回射干涉检测影响不明显,如要严格消除,可将两通道错开一适当距离. 相似文献
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利用电子束热蒸发方法在K9玻璃基底上沉积氧化锆薄膜,并对其中一些样品用低能O2+进行了后处理。采用表面热透镜技术测量薄膜样品表面弱吸收,采用显微镜观察样品离子后处理前后的显微缺陷密度。测试结果表明:经离子后处理样品表面的缺陷密度从18.6/mm2降低到6.2/mm2,且其激光损伤阈值从15.9 J/cm2提高到23.1 J/cm2,样品的平均吸收率从处理前的1.147×10-4降低到处理后的9.56×10-5。通过对处理前后样品的表面微缺陷密度、吸收率及损伤形貌等的分析发现:离子后处理可以降低薄膜的显微缺陷和亚显微缺陷,从而降低薄膜的平均吸收率,同时增强了薄膜与基底的结合力,提高了薄膜的激光损伤阈值。 相似文献
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热透镜技术按照测量方式的不同可以分为反射式和透射式两种。这两种方式的灵敏度强烈地依赖于样品的热物理性质,对于不同的样品,选择合适的测量构型尤为重要。采用高斯激光束作为加热光源,分别从理论和实验上比较分析了模式不匹配的反射式和透射式两种热透镜探测构型在测量以BK7玻璃和石英为基底的高反射光学薄膜弱吸收中的应用,结果表明,对以BK7玻璃为基底的样品,采用反射式探测构型具有较高的灵敏度,而对以石英为基底的样品而言,采用透射式探测构型则具有更高的灵敏度,为实际光学薄膜吸收损耗测试灵敏度的提高提供了理论和实验依据。 相似文献
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采用离子束辅助电子束成膜,用双重膜厚监控方法监控各膜层厚度,制备了45°入射、808nm高反、1064nm高透的消偏振二向色镜,并用于全固态355nm激光器.将部分薄膜样品在250℃进行退火处理后,用Lambda950分光光度计测试该样品的光谱性能;用表面热透镜技术测量退火前后该样品的弱吸收值;用激光阈值损伤装置测试该样品在1064nm调Q激光下的损伤阈值;用NIKON显微镜观察样品在不同激光能量辐照下的破斑形貌.实验结果表明:波长为808nm和1 064nm时,薄膜透射率分别为0.04%和99.6%,符合设计要求,满足全固态355nm紫外激光器系统所要求的光学性能指标;退火后的弱吸收值较退火前有所降低;在激光作用下薄膜产生微破坏喷出,说明膜层不会向灾难性破坏演变. 相似文献
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固体激光棒中的热透镜效应对激光器的性能有很大的影响.在固体激光器的热稳腔的设计中也需要知道激光棒的热透镜焦距的数值,因此测量激光棒的热透镜焦距是必要的和有意义的.我们采用类似于文献[1]中的方法,测量了三种常用的固体激光棒在泵浦期间和泵浦后,各个时刻的热透镜焦距的数值.在单脉冲泵浦期间,红宝石、Nd:YAG和钕玻璃三种激光棒的热透镜焦距均为负值. 测量热透镜焦距的原理如图1所示.设He-Ne探测激光束的束腰半径为ω0,束腰和光阑离热透镜的距离分别为d1和d2。ωn和ωm分别为存在热透镜(例如负透镜)和无热透镜时探测激光束到达光… 相似文献
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给出了连续调制激励光照射下光学薄膜样品表面热变形场的理论分布,并由此定义了表面热透镜(STL)信号。根据表面热透镜理论实验测量了一个BK7基底高反膜样品的形变,给出了表面热透镜信号随调制频率的变化曲线。实验结果表明:在采用的STL实验构型中,探测了最小1.985 nm的直流形变,对应不调制时的形变为3.97 nm,相应的形变探测灵敏度达到了10 pm量级;直流形变与功率成线性关系;交流表面热透镜信号随着频率增大而减小,在高频端近似成线性减小。 相似文献
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Surface thermal lens (STL) signal produced by a cw
modulated top-hat beam excitation is detected by an obliquely-incident probe
beam. The dependence of the STL amplitude on the incident angle θ of the
probe beam is experimentally investigated. The STL amplitude as a function
of the detection distance is measured at different angles of incidence. The
results show that the maximum STL amplitude and the optimum detection
distance, where the maximum STL amplitude is obtained, decrease by
cosθ as the incident angle increases. These experimental dependences are well
explained by a simple theoretical model. 相似文献
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J. RigueD. Chrischon A.M.H de AndradeM. Carara 《Journal of magnetism and magnetic materials》2012,324(8):1561-1564
We describe the development of an automatic torque magnetometer based on a torsion pendulum. The instrument uses the capacitive arrange developed by Randall D. Peters, Rev. Sci. Instr. 60 (8), 2789 (1989), as sample's angular position sensor. The instrument performance is illustrated by measuring the in plane magnetic anisotropy of Co thin films and systems with exchange-bias. It possesses a sensitivity of 10?10 Nm and is capable to determine anisotropy constants in magnetic films as thin as 3 nm. The instrument design and the measurement procedures are presented. 相似文献
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为探讨薄膜型声学超材料用于汽车前围声学包、提高其中低频隔声能力的可行性,设计一种米字摆臂多质量块薄膜型声学超材料,构建其隔声分析有限元模型,分析其隔声特性及影响因素,开展结构优化及其在汽车前围声学包上的应用探索。研究表明,所设计的薄膜型声学超材料单胞在中低频区域具有较宽的隔声频带;增加薄膜上质量块半径或厚度会使传声损失曲线整体向低频区域移动,且质量块半径的增加还会拓宽高频区域的隔声频带;增加薄膜厚度或预应力会使传声损失曲线整体向高频区域移动;优化后的薄膜型声学超材料与钢板组合应用于汽车前围板,可明显提高其中低频隔声能力。 相似文献
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For modern processes at deep sub-micron technology nodes, yield design, especially the design at the layout stage is an important way to deal with the problem of manufacturability and yield. In order to reduce the yield loss caused by redundancy material defects, the choice of nets to be optimized at first is an important step in the process of layout optimization. This paper provides a new sensitivity model for a short net, which is net-based and reflects the size of the critical area between a single net and the nets around it. Since this model is based on a single net and includes the information of the surrounding nets, the critical area between the single net and surrounding nets can be reduced at the same time. In this way, the efficiency of layout optimization becomes higher. According to experimental observations, this sensitivity model can be used to choose the position for optimization. Compared with the chip-area-based and basic- layout-based sensitivity models, our sensitivity model not only has higher efficiency, but also confirms that choosing the net to be optimized at first improves the design. 相似文献
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A combined laser calorimetry (LC) and surface thermal lens (STL) technique with a continuous-wave (cw) modulated excitation
is developed for characterizing the absorption properties of optical coatings. LC and STL signals are simultaneously obtained
with highly reflective coating samples irradiated at 1064 nm. With a modulated irradiation power of 2.6 W, the limits of absorptance
detection for the LC and STL signals are approximately 1.2×10-6 and 0.5×10-6, respectively. The influences of different excitation parameters (modulation frequency, excitation-beam power and irradiation
time) on the absorptance measurements are experimentally analyzed. The applicability of the combined LC and STL technique
to the investigation of the laser-induced absorption changes of optical coatings in an absolute absorptance scale is demonstrated.
PACS 42.87.-d; 78.20.-e 相似文献
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In this study, a new prediction method is suggested for sound transmission loss (STL) of multilayered panels of infinite extent. Conventional methods such as random or field incidence approach often given significant discrepancies in predicting STL of multilayered panels when compared with the experiments. In this paper, appropriate directional distributions of incident energy to predict the STL of multilayered panels are proposed. In order to find a weighting function to represent the directional distribution of incident energy on the wall in a reverberation chamber, numerical simulations by using a ray-tracing technique are carried out. Simulation results reveal that the directional distribution can be approximately expressed by the Gaussian distribution function in terms of the angle of incidence. The Gaussian function is applied to predict the STL of various multilayered panel configurations as well as single panels. The compared results between the measurement and the prediction show good agreements, which validate the proposed Gaussian function approach. 相似文献
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Influence of Surface Transition Layers on Phase Transformation and Pyroelectric Properties of Ferroelectric Thin Film
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Taking into account surface transition layers (STLs), we study the phase transformation and pyroelectric properties of ferroelectric thin films by employing the transverse Ising model (TIM) in the framework of the mean field approximation. The distribution functions representing the intra-layer and inter-layer couplings between the two nearest neighbour pseudo-spins are introduced to characterize STLs. Compared with the results obtained by the traditional treatments for the thin films using only the single surface transition layer (SSL), it is shown that the STL model reflects a more realistic and comprehensive situation of films. The effects of various parameters on the phase transformation properties have shown that STL can make the Curie temperature of the film higher or lower than that of the corresponding Sulk material, and the thickness of STL is a key factor influencing the film properties. For a film with definite thickness, there exists a critical STL thickness at which ferroelectricity will disappear when the intra-layer and inter-layer interactions are weak. 相似文献