高温超导薄膜及微波器件应用

介绍了高温超导薄膜制备方法（如磁控溅射、脉冲激光淀积、电子束共蒸发、化学气相沉积等）研究的进展和现状．对薄膜生长中的一些技术，如外延生长高质量的薄膜对基片的要求、常用的基片、为了减小像硅和蓝宝石一类的重要基片与高温超导薄膜间的扩散以及改善晶格匹配所采用的缓冲层技术等也作了简要的介绍，还介绍了薄膜的微波性质和用高温超导薄膜制备的微淡无源器件．     

第一讲 高温超导薄膜及微波器件应用

介绍了高温超导薄膜制备方法研究的进展和现状，对薄膜生长的一些技术，如外延生长高质量的薄膜对基片的要求，常用的基片，为了减小像硅和蓝宝石一类的重要基片与高温超导薄膜间的扩散以及改善晶格匹配采用的缓冲层技术等也作了简要的介绍，还介绍了薄膜的微波性质和用高温超导薄膜制血的微波无源器件。     

Sb，In，P掺杂对SnO2薄膜透明导电性能的影响

采用溶胶凝胶（Sol-Gel）技术制备了SnO2：（Sb，In）透明导电薄膜，优化了制备工艺参数，获得了最佳制备条件．研究表明，4％的铟掺杂有效地改善了薄膜的内部结构，使得紫外-可见光的透过率显著增加；7％的锑掺杂释放出了更多的栽流子，使薄膜的方块电阻降低，2％的磷掺杂因准连续杂质能带的形成进一步提高了薄膜的电导率．Sb、In、P的掺入使得SnO2薄膜的紫外-可见光的透过率达83％，方块电阻达38Ω。     

退火对TiO2薄膜形貌、结构及光学特性影响

利用射频磁控溅射技术在熔融石英基片上制备TiO<,2>薄膜,采用X射线衍射、扫描电子显微镜(SEM)、拉曼光谱以及透过谱研究了退火温度和退火气氛对TiO<,2>薄膜的结构、形貌和光学特性的影响.实验结果表明:在大气环境下退火,退火温度越.高,薄膜晶化越好,晶粒明显长大,温度高于700℃退火的薄膜,金红石相已明显形成.实验还发现,退火气氛对金红石相的形成是非常重要的,拉曼光谱反应出Ar气氛退火,抑制了金红石晶相的发育,薄膜仍以锐钛矿相为主.Ar气氛退火的薄膜在可见光范围内的透过率比大气退火的要低,并且由透过率曲线推知:金红石的光学带隙约为2.8 eV,比锐钛矿的光学带隙小0.2 eV.     

离子束溅射沉积Ti-Ni薄膜及其电化学性能的研究

利用离子束溅射沉积的方法在不同基片温度条件下制备了不同成分的Ti-Ni贮氢薄膜，研究了其电化学贮氢性能。结果表明：用离子束溅射沉积制备的Ti-Ni薄膜的结构为非晶状，薄膜对基片的附着力较强，在冲放电循环50次后仍为非晶态；在基片温度为350℃时制备的薄膜的结构为晶态，在多次放电循环后呈现非晶化趋势；Ti-Ni薄膜具有较高的电化学活性，晶化薄膜比晶态薄膜的最大放电容量高，但晶化薄膜的循环稳定性差。     

“冷沉积”的Ag-BaO薄膜在超短脉冲激光作用下的光电发射

研究了冷沉积制备条件下获得的Ag-BaO薄膜在超短激光脉冲串作用下的光电发射．得到Ag-BaO薄膜的阈值光强为10W/cm²，光量子效率达10^-4数量级．光电流密度与入射光强的关系主要表现为一段曲率随光强增大而逐步减小的曲线．其光量子效率是一个可变值，它的变化规律同入射光强及薄膜本身的性能有关 关键词：     

纳米晶SnO2透明导电薄膜的研制

阐述了金属氧化物透明导电薄膜研究的发展情况及其应用前景。介绍了采用磁控溅射技术 ,使用混合气体Ar和O2 ,在衬底温度为 15 0～ 40 0℃的耐热玻璃基片上制备纳米晶SnO2 :Sb透明导电薄膜 ,通过测定X射线衍射谱 ,表明薄膜择优取向为 [110 ]和 [2 11]方向。测量了SnO2 :Sb薄膜的导电特性随衬底温度及氧分压的变化。光学特性测量结果表明薄膜具有较高的透过率。     

GdBaCuO超导薄膜Tc值的优化实验研究

用倒筒式直流磁控溅射装置在LaAlO₃单晶基片上原位沉积了GdBaCuO（GBCO）薄膜．系统调查了GBCO薄膜的超导性质与溅射温度T_s、溅射压力和靶组成的变化规律，发现在720—820℃较宽的基片温度范围、在较低的溅射气压（40Pa）、较高的溅射速率（0.03nm/s）下均可制备出T_c0＞92K，（005）峰摇摆曲线半高宽不大于0.2、膜面非常光滑且具有良好外延特性的c轴嵌镶单晶薄膜．在最佳条件下（T_s=820℃，气 关键词：     

基片温度和退火对DdIn2O4薄膜光学性质和载流子浓度的影响

对射频反应性溅射Cd-In合金靶制备的透明导电CdIn2O4薄膜，研究了基片温度及沉积后在氩气流中退火对薄膜的透射、反射和吸收光谱，光学常数和载流子浓度的影响。结果表明：提高基片温度减少了薄膜的载流子浓度，退火增加了薄膜的载流子浓度。随着基片温度提高，薄膜折射率n和消光系数κ的短波峰将逐渐蓝移，而退火使其出现红移。基片温度和退火对薄膜光学常数的影响与其对薄膜载流子浓度的影响是一致的。在制备CdIn2O4这样一种对于沉积方法和沉积条件极为敏感的透明导电薄膜的沉积过程中，这一现象对于实时监控具有极为重要的意义。     

用微波ECR等离子体溅射法在蓝宝石(0112)晶面上生长ZnO薄膜的研究

蓝宝石上外延生长ZnO薄膜在表面波和声光器件中有重要的应用．用微波电子回旋共振(ECR)等离子体溅射法在蓝宝石(0112)晶面上外延生长了ZnO薄膜,膜无色透明,并且表面光滑,基片温度为380℃,为探索沉积工艺参数对薄膜结构的影响,用XRD对不同基片温度和沉积速率生长的ZnO薄膜进行了研究．     

非化学计量比靶材溅射制备Cu-Al-O薄膜的光学电学性质研究

考虑到铜铝溅射速率的差别,使用铜铝比例为0.9 ∶1的多晶CuAlO₂靶材,用射频磁控溅射法制备Cu-Al-O薄膜.研究不同衬底温度对薄膜光学电学性能的影响.在衬底温度500 ℃附近,薄膜在可见光范围内具有很好的透光性,达到70%,计算拟合得到直接帯隙为3.52 eV,与CuAlO₂相的理论值符合较好.在室温附近,薄膜导电符合半导体热激活机理,在衬底温度为500 ℃附近薄膜电导率达到2.48×10^-3 S·cm^-1. 关键词： Cu-Al-O 衬底温度 透过率 电导率     

Collection efficiency of scattered light in single-ended optical fiber sensors

Optical fibers allow a variety of spectroscopic sensing methods to be implemented in a single-ended backscattering geometry. Taking multimode fibers with surface-enhanced Raman scattering active tips as a model system, it is shown that the remote single-ended collection geometry can be relatively inefficient in comparison to the performance of the underlying sensor structure. Therefore the performance of the single-ended geometry has been compared to the analogous sensor structure on a nonguiding silica glass substrate. While part of the reduction in collection efficiency can be attributed to mismatches between the numerical aperture of the collection optics and that of the fiber, this study suggests that there can be an additional loss due to a mismatch between the confocal area of the collection optics and the area of the fiber core. This effect is most significant for high numerical aperture objectives. However, the collection efficiency is somewhat higher than would be expected from a simple area ratio analysis. This can be attributed to the graded-index fiber used in the model system and the relaxation of confocal requirements in the longitudinal direction.     

Characterization of the linear optical properties of a multiple quantum well structure in the sheet-model approximation

The possibility of determining the linear optical response tensor of a multiple quantum well (MQW) structure from optical reflection spectra is discussed. Taking into account local-field effects, the optical parameters of the MQW system are derived directly from the sheet conductivity tensor of the individual quantum well. For an amorphous Si/SiO₂ MQW structure deposited on a crystalline Si substrate, both s- and p-polarized reflection spectra were measured at different angles of incidence in the near-infrared and visible frequency regions. It was shown that the s-polarized spectra can be characterized by means of only one (complex) parameter, whereas in general it is impossible to account for the p-polarized spectra parametrically in a full range of angles of incidence even with four angular independent parameters. Finally, it was demonstrated that Feibelman's d-parameters can only be used to describe the experimental spectra at near-normal and grazing angles of incidence.     

Compact planar optical correlator

A compact planar configuration for performing optical correlation is described. It comprises two pairs of identical holographic lenses and a holographic filter. Each pair of lenses is recorded on a single substrate; together the lenses perform exact Fourier transformation. The light between the lenses propagates inside the substrate by total internal reflection. The design and recording considerations for each of the elements along with experimental results for the overall planar correlator are presented.     

光学窗口形变对平行光管光学性能影响分析

由于环境工况的多变性,光学窗口设计交叉了光、机、热等多种学科。在压差、轴向温差及径向温差工况下,分析光学窗口形变对某大口径、长焦距平行光管光学性能的影响,建立了光学窗口的有限元模型,与理论结果进行对比,验证了该有限元模型的有效性。以有限元分析得出的光学窗口变形数据为输入数据,带入改进了的Zernike多项式光机分析接口程序,获得了与像差对应的Zernike系数。用得到的Zernike系数表示光学窗口面型,以波像差作为光学系统成像质量评价指标,分析光学窗口变形对大口径、长焦距平行光管系统光学性能的影响。结果表明:光学窗口变形对平行光管系统光学性能的影响可以忽略不计。     

光栅光学双稳态

本文报道了一种光栅光学双稳态装置.利用改变一对对称光栅间相对位移,实现了对透过光强的周期性调制.将这样的系统作为传输部分,分别用He-Ne激光和普通白光完成了光学双稳实验.实验结果与理论分析相符.     

Superheating of thin films for optical recording

Two methods for calculating the temperature in a thin film on a substrate during laser exposure are discussed. A simple algebraic expression gives a satisfactory estimate for the maximum temperature if radial diffusion of heat is negligible. A numerical method is applied to calculate the temperature profile in a tellurium film on a PMMA substrate. The calculations show that for pulse times below about 10 μs, the temperature at which hole opening occurs, is considerably above the melting point of tellurium. This indicates that for small pulses the solid film is locally superheated due to the limiting kinetics of the melting process.     

光学镜面复制技术的研究

光学镜面复制技术包括镀膜、胶合、脱模等工艺 ,这是一种通过压模的方法生产光学镜面的技术。一个镀好膜的高精度母模的光学面被复制到没有抛光过的复制件非光学表面上 ,母模和复制件之间的面形误差由胶粘剂补偿 ,通过脱模 ,可以得到一个镀好膜的由基体和胶粘剂组成的复制光学面。探讨了光学镜面复制技术的工艺方法 ,给出了所复制的球面、非球面、二次复制平面的干涉图和阴影图。     

Measurement of optical absorption in dielectric reflectors

The absorption of optical coatings can be measured by the method described with an accuracy of 0.001%. The radiation absorbed by the optical coating causes a change in the temperature of the coating and the substrate. The temperature change is measured by means of a thin-film resistance thermometer deposited on the substrate. The method was tested for laser reflectors at 1060 nm with a laser as a light source.     

Gradient-index planar optics for optical interconnections

Use of a gradient-index (GRIN) substrate is proposed as a novel signal-propagation medium for planar optics. The GRIN substrate provides planar optics designers not only a three-dimensional light propagation space but also smart optical diffraction-limited imaging. Experimental results on the imaging of an input signal to multiple destinations by the GRIN planar optics are presented.