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Analysis of Cr atom focusing deposition properties in the double half Gaussian standing wave field 下载免费PDF全文
The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation is investigated and the trajectories of atoms in double half Gaussian standing wave field are simulated. Compared with the Gaussian standing wave field, the double half Gaussian standing wave can well focus the Cr atoms. In order to obtain this kind of beam, a prism is designed and the experimental result shows that the beam is well generated. 相似文献
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计算电容是复现电学阻抗单位的基准装置, 利用计算电容值和量子霍尔电阻值可以准确计算出精细结构常数α. 计算电容的本质是通过高准确度地测量屏蔽电极的位移, 实现对电容量值的测量. 因此, 基于Fabry-Perot干涉仪的精密电极位移测量系统是计算电容装置中最为核心和关键的部分. 在Fabry-Perot干涉仪测位移过程中, 由于高斯激光束存在轴向Gouy相位, 该附加相位将会引起相邻干涉条纹对应位移的变化(大于或者小于λ/2), 导致位移的测量值与实际值存在偏差. 本文阐述了高斯激光场的传播特性, 利用高斯激光束在自由空间和透过薄透镜复振幅的变换关系, 建立了计算电容装置中Fabry-Perot干涉仪透射光束的传输模型; 通过对不同腔长的Fabry-Perot干涉仪透射光场相位的分析, 获得了高斯激光束轴向Gouy相位修正与传输距离的关系. 结果表明, 当腔长从111.3 mm移动至316.3 mm时, 在接收距离为560 mm的情况下, 高斯光束轴向Gouy 相位引起的位移修正的绝对值最小为0.7 nm, 其相对相位修正量|δL|/|ΔL| = 3.4×10-9. 相似文献
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为了说明原子光刻(Atom Lithography)在纳米计量及传递作用中的特殊地位,首先对纳米计量标准及其现状进行了简要介绍,提出纳米计量中原子光刻的基本概念和优势,结合原子光刻实验装置对原子光刻技术的工作机理进行了分析。结果表明,可以通过原子光刻技术得到纳米量级刻印条纹,为纳米计量及标准传递提供更加精确的手段。最后对常见的2种原子光刻技术——沉积型原子光刻和虚狭缝型原子光刻进行了阐述,指出2者的不同之处,为不同条件下原子光刻提供了一定的借鉴。 相似文献
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Structured mirror array for two-dimensional collimation of a chromium beam in atom lithography 总被引:1,自引:0,他引:1 下载免费PDF全文
Direct-write atom lithography,one of the potential nanofabrication techniques,is restricted by some difficulties in producing optical masks for the deposition of complex structures.In order to make further progress,a structured mirror array is developed to transversely collimate the chromium atomic beam in two dimensions.The best collimation is obtained when the laser red detunes by natural line-width of transition 7S3 → 7P40 of the chromium atom.The collimation ratio is 0.45 vertically(in x axis),and it is 0.55 horizontally(in y axis).The theoretical model is also simulated,and success of our structured mirror array is achieved. 相似文献
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This paper presents the experimental progress of laser-focused Cr atomic deposition and the experimental condition.The result is an accurate array of lines with a periodicity of 212.8±0.2 nm and mean full-width at half maximum as approximately 95 nm.Surface growth in laser-focused Cr atomic deposition is modeled and studied by kinetic Monte Carlo simulation including two events:the one is that atom trajectories in laser standing wave are simulated with the semiclassical equations of motion to obtain the deposition position;the other is that adatom diffuses by considering two major diffusion processes,namely,terrace diffusion and step-edge descending.Comparing with experimental results(Anderson W R,Bradley C C,McClelland J J and Celotta R J 1999 Phys.Rev.A 59 2476),it finds that the simulated trend of dependence on feature width is in agreement with the power of standing wave,the other two simulated trends are the same in the initial stage.These results demonstrate that some surface diffusion processes play important role in feature width broadening.Numerical result also shows that high incoming beam flux of atoms deposited redounds to decrease the distance between adatoms which can diffuse to minimize the feature width and enhance the contrast. 相似文献
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本文在论述影响硅光电二极管外量子效率诸因素的基础上,着重讨论了器件的收集效率,给出了确定器件外量子效率的一般公式和简化公式。对三个器件进行了自校准实验,确定外量子效率的不确定度在±0.05%,三个器件测量激光束功率的一致性在±0.05%,与现有的绝对辐射计测量结果符合在0.2%。 相似文献
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Based on the semi-classical model, we analyse the motion equation of chromium atoms in the laser standing wave field under the condition of low intensity light field using fourth-order Adams-Moulton algorithm. The trajectory of the atoms is obtained in the standing wave field by analytical simulation. The image distortion coming from aberrations is analysed and the effects on focal beam features are also discussed. Besides these influences, we also discuss the effects on contrast as well as the feature width of the atomic beam due to laser power and laser beam waist. The simulation results have shown that source imperfection, especially the transverse velocity spread, plays a critical role in broadening the feature width. Based on these analyse, we present some suggestions to minimize these influences. 相似文献