An Iterative Formula for the Reflection Coefficient of Multi-layer Thin Film and Its Application in the Design of Optical All Pass Filter

In this paper, an iterative formula for the reflection coefficient of the multi-layer thin film is deduced and the design of multi-layer thin film gires-tournois interferometer optical all pass filter(GTI-OAPF) is discussed. The group delay τm ranges from 0. 06 to 460 ps and the bandwidth △ω ranges from 0.068 to 0.0000079 (1015 rad/s). By changing the incident angle θ0, the multi-channel dispersion compensation may be achieved.     

The development of the physical and electrical characteristics of multi-layer TiO<Subscript>2</Subscript>–W–TiO<Subscript>2</Subscript> thin films

In this study, two different thin films, TiO₂ thin film and TiO₂–W–TiO₂ multi-layer thin films (W, tungsten), are prepared by RF magnetron sputtering onto glass substrates. The crystal structure, morphology, and transmittance of TiO₂ and TiO₂–W–TiO₂ multi-layer thin films are investigated by X-ray diffraction, SEM, and UV-Vis spectrometer, respectively. The amorphous, rutile, and anatase TiO₂ phases are observed in the TiO₂ thin film and in the TiO₂–W–TiO₂ multi-layer thin films. The deposition of tungsten as the inter-layer will have large effect on the transmittance and phase ratios of rutile and anatase phases in the TiO₂–W–TiO₂ multi-layer thin films. The crystal intensities of amorous TiO₂ will decrease as the tungsten is used as the middle layer in the multi-layer structure. The band gap energy values of TiO₂ thin film and TiO₂–W–TiO₂ multi-layer thin films are evaluated from (αhν)^1/2 versus energy plots, and the calculated results show that the energy gap decreases from 3.21 eV (TiO₂ thin film) to 3.08∼3.03 EV (TiO₂–W–TiO₂ multi-layer thin films).     

高温超导YBa2Cu3O7-δ-Y2O3多层薄膜的制备及性能表征

采用脉冲激光沉积技术(PLD)在LaAlO3(100)单晶衬底上外延生长YBa2Cu3O7-δ-Y2O3多层薄膜,用X射线衍射技术(XRD)分析薄膜的物相结构和外延特性,通过原子力显微镜(AFM)观察薄膜的表面形貌.本文主要研究了最佳工艺参数下交替生长多层YBCO-Y2O3膜的超导性能.结果表明,YBa2Cu3O7-δ-Y2O3薄膜为纯c轴取向外延生长,临界电流密度Jc(H=0或H//C)均高于纯YBCO薄膜,纳米Y2O3起到磁通钉扎中心作用.     

多层介质膜光栅用高反射镜的严格耦合波分析

基于严格耦合波和增强透射矩阵的方法,提出了一种数值稳定的求解多层介质膜光学特性的机理模型.利用该模型计算了多层介质膜光栅用高反射镜的优化设计膜系.使用电子束热蒸发方式制备的多层介质膜光谱特性和理论设计的结果符合得很好,该严格耦合波模型是分析介质膜光学特性有效的稳定的数值求解方法.     

Design of Millimeter Wave TFMS Bandpass Filter

In this paper, a Ka-band thin film microstrip line(TFMS) filter with multi-layer structure on silicon substrate is introduced. The simulated results show that it is possible to design compact millimeter-wave filter on silicon substrate with process compatible to current VLSI technology.     

Ag-BaO纳米薄膜红、蓝紫光波段光致荧光现象研究(Ⅰ)

金属纳米粒子/介质复合薄膜因其优良的光电特性和超快响应而成为应用背景很强的光电功能薄膜-采用真空沉积的方法制得了Ag-BaO纳米薄膜,测试到其在室温条件下的红光和蓝紫光波段的光致荧光光谱,认为Ag-BaO纳米薄膜的荧光发射主要来自于Ag纳米粒子的贡献-与该种材料的紫外-可见光吸收谱相比较,分析了Ag-BaO纳米薄膜材料不同可见光波段的荧光产生机理- 关键词：     

10.6μm激光辐照下光学薄膜的微弱吸收测量

 建立了表面热透镜技术测量光学薄膜微弱吸收的实验装置，对10.6μm CO₂激光辐照下镀制在Ge基底上的不同厚度的单层ZnS，YbF₃薄膜，以及镀制在Ge基底上不同膜系的（YbF₃/ZnSe）多层分光膜的弱吸收进行了测量，并对实验结果作了分析和讨论。实验结果表明，利用本实验系统已测得的待测样品的最低吸收为2.87×10^-4，测量系统的灵敏度为10^-5。     

Laser welding of thin polymer films to container substrates for aseptic packaging

Keyhole laser welding of polymers is a subject well covered and researched, but relatively little information exists regarding the welding of thin polymer films, particularly to a heavier substrate. This paper presents the design of a suitable test apparatus for laser welding thin film to a heavier substrate, and shows the results of an investigation into the feasibility of laser welding multi-layer polymer film lids to tubs for the manufacture of aseptic food containers. A consistent weld, free from defects, is the key to process success. Typical welding defects have been synthesised in order to investigate, and consequently remove, their cause. The result is a reliable welding method based on even film clamping. With careful attention to machine design, a seal of high mechanical strength and chemical integrity is possible.     

Application of auger ewlectron depth profile analysis to thin film interdiffusion studies

Because of its good depth resolution, the Auger electron depth profile analysis allows to investigate diffusion phenomena in thin films directly. Complicated calibration procedures, however, are needed to correct for the matrix effects inherent in the Auger method, particularly artefacts due to the sputtering process. In this paper, two types of thin-film systems are presented in order to determine diffusion coefficients from depth profiles: double-layer and periodic multi-layer film structures. Compared to the double-layer films, the multi-layer structure has the advantage of less stringent requirements on depth resolution and allows to detect smaller diffusion effects. Finally, it is shown how grain boundary and bulk diffusion data can be extracted separately from the composition profiles.     

Design and properties analysis of multi-layer dielectric used in pulse compressor gratings

Used in chirped-pulse amplification system and based on multi-layer thin film stack, pulse compressor gratings (PCG) are etched by ion-beam and holographic techniques. Diffraction efficiency and laser-induced damage threshold rely on the structural parameters of gratings. On the other hand, they depend greatly on the design of multi-layer. A theoretic design is given for dielectric multi-layer, which is exposed at 413.1 nm and used at 1053 nm. The influences of coating design on optical characters are described in detail. The analysis shows that a coating stack of H3L (H2L)9H0.5L2.01H meets the specifications of PCG well. And there is good agreement of transmission between experimental and the theoretic design.     

样品厚度对薄膜法X射线荧光光谱测量的影响研究

分别以富集有Cr,Pb和Cd三种元素的尼龙薄膜样品及玻璃纤维滤膜为研究对象,采用滤膜叠加的方式,通过XRF光谱仪测量不同样品厚度下薄膜样品的XRF光谱,根据测得的尼龙薄膜样品中Cr,Pb,Cd元素及玻璃纤维滤膜中Ca,As和Sr元素特征XRF性质的变化,研究样品厚度对薄膜法XRF光谱测量的影响。结果表明：薄膜样品厚度对不同能量区间上元素特征谱线荧光性质的影响并不相同。元素特征谱线能量越大,元素特征X射线荧光穿透滤膜到达探测器的过程中损失越少;但由薄膜样品厚度增加引起的基体效应却越强,相应特征谱线位置处的背景荧光强度就越大,因此样品厚度增加所引起的基体效应对薄膜法XRF光谱测量的灵敏度影响就越大。对于特征谱线能量较低(能量小于7 keV)的元素,以增加薄膜样品厚度的方式来增加待测组分的质量厚度浓度,并不能有效地提高薄膜法XRF光谱测量的灵敏度;对于特征谱线能量较高的元素(能量＞7 keV),可以通过适当增加样品厚度以增加被测组分的质量厚度浓度的方式来提高XRF光谱测量的灵敏度,薄膜样品厚度在0.96～2.24 mm内,更有利于XRF光谱的测量与分析。该研究为大气及水体重金属薄膜法XRF光谱分析中薄样制备及富集技术提供了重要的理论依据。     

Full field and microregion deformation measurement of thin films using electronic speckle pattern interferometry and array microindentation marker method

Thin films now are widely used in micro devices and structures, such as MEMS, electronic packaging, micro sensors, and so on. Their performances highly affect the reliability of the devices. Therefore, it is important to investigate the deformation and the failure mechanism of thin films. In this paper, we present two experimental methods to measure the mechanical properties of thin films. In the first method, a double-field-of-view electronic speckle pattern interferometry system (ESPI) and an integrated deformation and load measurement system are employed, which allows in situ and real-time measurements of full-field deformations of the thin films and microforces under uniaxial tensile test. In the second method, the array microindentation markers were indented on the surface of the thin film using a nanoindenter and the microregion deformations of the tested thin films were measured. In the proposed methods, the tested thin films can be made of metals, oxide ceramics, and multi-layer composites of thickness from several tens micrometers to less than a micron, and the tensile loads from 88 μN to 15 N for the first method or up to 100 N to the second one. The underlying principle of the methods and the experimental set-ups are presented. The deformations of Au and Au/Cr multi-layer films, and the pure Ni films are measured. The performance of the methods and the testing systems are also discussed.     

脉宽压缩光栅用的多层膜设计和性能分析

应用于啁啾脉冲放大技术中的脉宽压缩光栅是基于多层膜作为基底,利用全息干涉技术和离子束技术刻蚀而成。脉宽压缩光栅的衍射效率和抗激光损伤阈值一方面依赖于光栅结构的设计,另一方面很大程度上取决于作为基底的多层膜的设计。给出了以413.1nm作为写入波长,1053nm作为使用波长的多层介质光栅膜的设计,样品在ZZS-800F型真空镀膜机上采用电子束蒸发方式沉积而成,并给出了膜系结构对光学性能影响因素的详细分析,结果表明膜系H3L(H2L)9H0.5L2.03H满足光栅膜的指标。给出了样品光学特性测试,其使用波长处的透射率<0.5%,写入波长处的透射率>90%,测试表明样品满足设计要求且实验结果和理论设计符合得很好。     

Equilibrium and kinetic surface segregation in binary alloy thin films

A general theoretical analysis of the effect of film thickness on equilibrium and kinetic surface segregation in binary alloy thin films is presented. In this analysis, a constrained condition that represents the finite size of thin film system has been introduced to the modified Darken model, which has been used to describe both equilibrium and kinetic surface segregation in bulk materials. Simulation of surface segregation for alloy thin films can be carried out for all composition ranges and all film thicknesses if only knowing the surface segregation parameters for bulk materials. Simulations of equilibrium and kinetic surface segregation in Cu(1 1 1)Ag binary alloy thin film are presented.     

Pulsed laser deposition and its current research status in preparing hydroxyapatite thin films

Pulsed laser deposition (PLD) is a conceptually and experimentally simple yet highly versatile tool for thin films and multi-layer film research. The mechanisms, advantages and disadvantages of pulsed laser deposition were reviewed. The process and some methods to resolve the drawbacks of PLD were discussed. Pulsed laser deposition of hydroxyapatite thin films was reviewed. Simple adjustment of PLD parameters can deposit hydroxyapatite in situ in crystalline form, amorphous films or HA with other calcium phosphate phases. Compared with plasma sprayed HA coatings the pulsed laser deposition HA thin films have higher coating/substrate adhesion and have minor undesirable phases under optimal conditions. Finally, we suggested some new researches should be done.     

覆面层对玻璃棉吸声性能的影响

本文通过试验探讨了四种覆面怪对玻璃板吸声性能的影响，结果表明：在不同频率范围，铝箔及穿孔铝穆面层对的吸声性能影响较大，而玻纤毡和橡胶面层的影响较小。     

Characterization and comparison of X-ray focusing optics for ultrafast X-ray diffraction experiments

We have characterized and compared the performance of different types of multi-layer optics for the focusing of femtosecond X-ray pulses. Using X-ray pulses at 8 keV, from a laser-driven plasma source we have measured the spatial distribution of the diffracted X-rays directly after and in the focal plane of the various X-ray optical devices. For a Montel optic with 7.3× magnification we obtained the largest number of focused X-ray photons per unit angle. The performance of this optic in the X-ray diffraction experiment on a thin germanium film is demonstrated.     

多层介质膜脉宽压缩光栅的严格矢量分析

用于展宽和压缩激光脉冲的多层膜脉宽压缩光栅是由多层介质高反膜和位于其顶层的浮雕光栅构成。以设计的高反射多层膜为基础,利用傅里叶模式理论分析了其衍射场分布,给出了TE波自准直角入射的使用条件下,多层介质膜脉宽压缩光栅衍射效率的表达式。以-1级衍射效率为评价函数,分别讨论了HfO2和SiO2为顶层材料时,多层膜脉宽压缩光栅-1级衍射效率高于0.95的光栅结构参量范围。结果表明,在该条件下,选择HfO2为顶层材料时,光栅结构参量有较大的取值范围。给出了优化的光栅结构参量,并分析了光栅制作误差及其使用条件的宽容度,对光栅制作工艺和使用具有一定的指导意义。     

Si基铁电Bi3.15Nd0.85Ti3O12多层薄膜的一致取向生长和性能的研究

采用脉冲激光沉积(PLD)技术，利用LSCO/CeO₂/YSZ多异质缓冲层，在Si(100)基 片上成功地制备了c轴一致取向的Bi_3.15Nd_0.85Ti₃O12(BNT)铁电薄膜.利用X射线衍射(XRD)和扫描电镜(SEM)分析测定了薄膜的相结构 、取向和形貌特征，考察了沉积温度和氧分压对BNT薄膜微结构、取向和形貌的影响，确定 了BNT薄膜的最佳沉积条件.对在优化的条件下制备得到的BNT薄膜的C-V曲线测试得到了典型 的蝴蝶形曲线，表明该薄膜具有较好的电极化反转存储特性.最后讨论了BNT薄膜铁电性能与 薄膜取向的相关性. 关键词： 3.15Nd_0.85Ti₃O₁₂')" href="#">Bi_3.15Nd_0.85Ti₃O₁₂ 铁电薄 膜 多层异质结 脉冲激光沉积     

SrTiO_3(001)衬底上多层FeSe薄膜的分子束外延生长

近几年,由于用分子束外延法在SrTiO_3衬底表面制备的单层FeSe具有很高的超导转变温度而引发了极大的研究热潮,随之而来的是对多层FeSe薄膜日益增长的研究兴趣.但目前还没有对成功生长高质量多层FeSe薄膜的详细报道.本文利用高能电子衍射仪(RHEED)实时监控在不同生长条件下制备的多层FeSe薄膜,发现在FeSe薄膜的生长初期,RHEED图像的强度演化基本符合台阶密度模型的描述特征,即台阶密度ρ正相关于衍射条纹强度.FeSe(02)衍射条纹的强度在第一生长周期内呈现稳定而明显的峰型振荡,而且不受高能电子掠射角的影响,最适合用来标定FeSe薄膜的厚度.结合扫描隧道显微镜对FeSe薄膜质量的原位观察,确定了制备多层FeSe薄膜的最佳生长条件,为FeSe薄膜的物性研究提供了重要的材料基础.