新型极化聚合物薄膜电光调制器研究

用对硝基偶氮苯类为侧链的键合型聚合物，采用高温电晕极化的方法制作电光薄膜，设计并构造极化聚合物薄膜电光调制器。当通光方向和极化方向平行并且垂直于极化聚合物薄膜的表面时，利用法布里-帕罗（F-P）腔中多光束干涉，可以把通过的光由位相调制转化为强度调制，有利于电光调制器的小型化和高速封装。用这种聚合物薄膜电光调制器测量了锢锡氧化物共面波导上的电信号，并对系统的工作原理进行了分析。实验结果表明，薄膜调制器具有线性电光效应；当F-P腔的精细因子为20（为1.3μm的光），调制电场为1V/μm时，研制的极化聚合物电光调制器的调制深度可达到0.01%。     

基于铌酸锂薄膜波导的电光调谐光栅辅助定向耦合器研究

提出并实验研究了一种基于铌酸锂薄膜光波导的电光调谐的光栅辅助定向耦合器。该耦合器由单模与双模脊形波导及制作于双模波导侧壁的长周期光栅构成。长周期光栅的引入补偿了单模与双模波导中基模的相位失配,可在共振波长实现两波导中基模的高效耦合。进一步地,在双模脊形波导两侧制作调谐电极实现了高速、低驱动电压的电光调谐功能。优化了器件的制作工艺,并采用单次干法刻蚀将耦合器的光栅与波导同步制作于X切铌酸锂薄膜上。测试结果表明所制作的器件在1 595.3 nm波长处实现了14.8 dB的隔离度,其电光调谐效率为0.38 nm/V(1 595.3 nm～1 599.0 nm),热光调谐效率为0.14 nm/℃（25℃～50℃）。该器件可用于实现可调谐滤波、滤模、电光调制及高灵敏度温度传感等功能。     

纳米晶聚合物复合薄膜PbTiO3-PEK-c的电光特性及其弛豫过程的研究

制备了掺杂型纳米晶聚合物钛酸铅聚醚醚酮 (PbTiO3 PEK c)复合薄膜 ,采用简单透射技术测量了该复合薄膜的线性电光系数 ,并研究了该复合薄膜的电光特性的弛豫过程     

聚合物薄膜电光效应研究

介绍聚合物DR/PMMA薄膜材料做成光学法布里-珀罗腔结构,通过观察透射率随外加电场变化,以确定其非线性光学特性参量,在室温和575.0nm时的三阶极化率x~⑶(-ω;ω,0,0)=(5.3-i6.0)×10~((-11)_(θs.u))和二次电光系数R=-(8.5-i9.7)×10~(-19)m~2/V~2.     

PT-PEK-c电光聚合物薄膜的厚度和介电性质

研制了新的PT-PEK-c电光聚合物薄膜材料,用准波导耦合m线方法测量了PT-PEK-c电光聚合物薄膜的厚度,并测量了该聚合物薄膜在1×10²Hz到1×10⁷Hz频率范围内的室温介电常数.测量结果为:厚度d=2.328±0.315μm,在10KHz下,介电常数ε_r＝4023±0.063,介电损耗tanδ＝0.003.     

纳米晶聚合物复合薄膜PbTiO3—PEK—c的电光特性及其驰豫过程的研究

制备了掺杂纳米晶聚合物钛酸铅－聚醚醚酮（PbTiO3-PEK-c) 复合薄膜，采用简单透射技术测量了该复合薄膜的线性电光系数,并研究了该复合薄膜的电光特性的驰豫过程。     

铁电SBN薄膜电光系数的测量及其在波导中的应用

利用溶胶-凝胶法在MgO(001)衬底上获得C轴择优取向的铁电铌酸锶钡(SBN)薄膜,主要介绍MgO(001)衬底上SBN60薄膜及掺入的K离子与Nb离子摩尔比例为1：3的SBN60薄膜横向电光系数r51的测量,实验测得不掺K的SBN60薄膜r51值为37．6pm／V,掺K的r51值为58．5pm／V。并由此设计一种基于MgO(001)衬底上的马赫一曾德尔型SBN60薄膜波导调制器,计算出在633nm时,掺K比例为1：3的此种波导调制器半波调制电压值为10V,不掺K的半波电压值为16V,结果说明掺入K离子能增加薄膜的横向电光系数并有效的减少波导的半波调制电压。     

对硅片上自组装生长的Pentacene薄膜生长机制及其结晶相态的研究

采用热蒸发的方法在硅片衬底上自组装生长的Pentacene薄膜,薄膜在80℃温度下经2 h恒温真空热处理,通过原子力显微镜(AFM)对Pentacene薄膜表面形貌及其生长机制进行研究.结果得到,在硅片上生长的Pentacene薄膜足以台阶岛状结构生长,其岛状直径约为100 nm.且Pentacene分子以垂直于衬底的方向生长,台阶岛状结构中每个台阶的平均高度约为1.54 nnl·s-1,与Pentacene分子的沿长轴方向的长度相近.从Pentacene薄膜的XRD图谱中可以看出,薄膜在形成的过程中会因条件的不同而形成不同的结晶相,分别为薄膜相和三斜体相,且薄膜的结晶相将随着薄膜厚度的增加向三斜体相转变,其临界厚度为80和150 nm,当薄膜大于150 nm时,薄膜的三斜体相占主导地位,而当Pentacene薄膜的厚度小于80 nm时,Pentacene薄膜呈薄膜相存在.     

不同厚度溅射Ag膜的微结构及光学常数研究

用直流溅射法在室温Si基片上制备了4．9nm-189.0nm范围内不同厚度的Ag薄膜，并用X射线衍射及反射式椭偏光谱技术对薄膜的微结构和光学常数进行了测试分析。结构分析表明：制备的Ag膜均呈多晶状态，晶体结构仍为面心立方；随膜厚增加薄膜的平均晶粒心潮6．3nm逐渐增大到14．5nm；薄膜晶格常数均比标准值（0．40862nm)稍小，随膜厚增加，薄膜晶格常数由0．40585nm增大到0.40779nm。250nm-830nm光频范围椭偏光谱测量结果表明：与Johnson的厚Ag膜数据相比，我们制备的Ag薄膜光学折射率n总体上均增大，消光系数k变化复杂；在厚度为4．9nm-83.7nm范围内，实验薄膜的光学常数与Johnson数据差别很大，厚度小于33．3nm的实验薄膜k谱线中出现吸收峰，峰位由460nm红移至690nm处，且其对应的峰宽逐渐宽化；当膜厚达到约189nm时，实验薄膜与Johnson光学常数数据已基本趋于一致。     

用不对称法布里-珀罗薄膜测量极化聚合物的电光效应

报道用不对称的法布里－珀罗（AFP）多光束干涉膜测量极化聚合物的线性电光效应。将聚合物在有高反射膜的载体上旋涂成膜后进行电晕极化,利用聚合物自身的反射率和高反射膜构成不对称的法布里－珀罗膜,用这种聚合物电光薄膜的自由放置方法和反射式光路构造电光检测系统,测量了铟锡氧化物共同波导上的电信号,并对系统的工作原理进行了理论分析。结果表明,不对称的法布里－珀罗薄膜具有线性电光效应,在1kHz正弦波时系统得到了5mV/√Hz的电压灵敏度。     

All-Optical Switching Based on Azo Polymer Material

Conventional all-optical switches based on azo polymer films and the all-optical switches based on the attenuated total reflection （ATR） geometry are investigated. A conventional switch system, including a pump beam of 532 nm and a probe beam of 650 nm, is based on the photoinduced birefringence effect of azo polymer. An ATR switch in a prism-multilayer configuration is achieved by changing the reflectance of the probe beam with an external pump beam. The ATR method provides the substantial improvement of the speed and the efficiency of the modulation over the conventional method. Although the azo polymer response still remains relatively slow, an enhanced nonlinear refractive index of the azo polymer film can effectively increase the modulation.     

An ATR analysis of surface roughness induced by electron bombardment

The surface roughness of aluminium films evaporated on quartz prism substrates increases when these films are irradiated by an electron beam under ultra-high vacuum. This conclusion is obtained through a detailed analysis of the evolution of the attenuated total reflection (ATR) dip during electron bombardment and from a theoretical investigation of the influence of surface roughness on the ATR resonance. The observation of a simultaneous increase of the light intensity scattered by the aluminium-vacuum interface confirms this interpretation.     

Interaction between localized and propagating surface plasmons: Ag fine particles on Al surface

Samples consisting of Ag fine particles 4nm in size placed near to an Al surface were prepared by depositing Ag-SiO₂ composite films by a rf cosputtering method onto vacuum-evaporated Al films. Angle-scan attenuated total reflection (ATR) measurements were performed over a wide wavelength range (λ=350-630nm) covering the resonance region (λ-410nm) of localized surface plasmon (LSP) in the Ag particles. It was found that the existence of Ag fine particles near to the Al surface led to a deformation of the dispersion curve of the surface plasmon polariton (SPP) propagating on the Al surface, in particular, in the LSP resonance region. The interaction between LSP and SPP was found to become much stronger as the distance between the particles and the surface decreases. The theoretical calculations based on the effective medium theory, which gave an effective dielectric function of the Ag-SiO₂ composite film, reproduced the deformation of the dispersion curve of the SPP. The deformation of the dispersion observed experimentally was qualitatively explained by the behavior of the effective dielectric function of the Ag-SiO₂ composite film.     

Glass transition in ultrathin polymer films: calorimetric study

The ultrasensitive differential scanning calorimetry is used to observe the glass transition in thin (1-400 nm) spin-cast films of polystyrene, poly (2-vinyl pyridine) and poly (methyl methacrylate) on a platinum surface. A pronounced glass transition is observed even at a thickness as small as 1-3 nm. Using the high heating (20-200 K/ms) and cooling (1-2 K/ms in glass transition region) rates which are typical for this technique, we do not observe appreciable dependence of the glass transition temperature over the thickness range from hundreds of nanometers down to 3 nm thick films. The evolution of calorimetric data with film thickness is discussed in terms of broadening of transition dynamics and loss of transition contrast.     

长程表面等离子体的增强效应

研究了双层金属薄膜构型中构型参数对长程表面等离子体的影响,并发现了衰减全反射激发方法下长程表面等离子体的增强效应.以特征矩阵算法为基础,通过数值计算构型的反射谱,研究构型参数的变化对反射谱的影响.发现由于衰减全反射激发方法中耦合器的存在导致的非对称特性,会使双层金属薄膜构型中的长程表面等离子体拥有本征模式特性以外的有趣特性,如长程模式得到增强而另一支受到抑制,从而使能量更为集中在希望被激发的一支.研究结果对非对称激发构型中的长程表面等离子体研究具有启发意义.     

导波法测量吸收薄膜的复介电系数和厚度

具有吸收特性的波导薄膜,其衰减全反射（ＡＴＲ）峰的位置和形状包含了薄膜诸多特征多数的信息,在同时考虑棱镜的耦合和材料的吸收的基础上,本文用一阶微扰理论推导了微扰传播常数的解析公式,并且介绍了通过分析薄膜的衰减全反射峰来计算吸收薄膜的复介电系数和厚度的方法。     

1-羟基-5-十二烷氧基-萘LB膜结构和取向的光谱研究

用红外透射,反射光谱及紫外可见吸收光谱方法研究了１－羟基－５－十二烷基－萘ＬＢ膜及溶液状态下的结构,分子取向。研究结果表明分子在溶液中主要是以单体形式存在;在ＬＢ膜中是以聚集体形式存在。     

复合薄膜的ATR-OMNI采样器的FTIR分析

使用OMNI采样器直接对复合薄膜进行单反射ATR傅里叶变换红外光谱分析，该方法快速、简便、不破坏样品，再与其他分析手段相配合，可以分析复合薄膜。     

Differential AC-chip calorimeter for glass transition measurements in ultra thin polymeric films

A differential AC-chip calorimeter capable to measure the glass transition in nanometer thin films is described. Due to the differential setup pJ/K sensitivity is achieved. Heat capacity can be measured for sample masses below one nanogram even above room temperature as needed for the study of the glass transition in nanometer thin polymeric films. The calorimeter allows for the frequency dependent measurement of complex heat capacity in the frequency range from 1 Hz to 1 kHz. The glass transition in thin films of polystyrene (PS) (100–4 nm) and polymethylmethacrylate (PMMA) (400–10 nm) was determined at well defined experimental time scales. No thickness dependency of the glass transition temperature was observed within the error limits (±3 K) - neither at constant frequency nor for the traces in the activation diagrams (1 Hz–1 kHz).     

Attenuated Total Reflection Spectra of Nitrided SiO2/Si Structures

Journal of Applied Spectroscopy - The behavior of nitrogen in silicon dioxide films on single-crystal silicon substrates was studied by attenuated total reflection (ATR) and time-of-flight...