用偏光织构及透射光谱分析液晶器件的老化

对一组台式计算器液晶显示器进行了光辐照,研究了光辐照对液晶显示器件显示品质的影响。采用偏光显微镜观察到了辐照后液晶的偏光织构的变化,液晶中出现了平行的条纹状织构和失去消光作用的黑洞,随着接受光辐照时间的增加,黑洞数量越来越多,面积越来越大。通过由计算机控制的双光束紫外-可见分光光度计测试了透射光谱的变化,发现其透射率随着接受光辐照时间的增加而降低。分析结果表明,条纹状织构和黑洞的出现是由于液晶分子结构在紫外线的照射下发生了变化所致,失去消光作用的黑洞是导致液晶器件透射率持续下降的主要原因。     

厚二氧化硅光波导薄膜制备及其特性分析

以硅烷和氧化二氮作为反应气体，采用等离子体增强化学气相沉积(PECVD)技术，不使用掺杂，在单晶硅衬底上制备了用于平面光波导的二氧化硅薄膜。研究了薄膜折射率和淀积速率与工艺参量之间的关系，通过棱镜耦合仪、傅里叶变换红外光谱、原子力显微镜等测试手段，分析了薄膜的结构和光学特性。结果表明，实验能快速生长厚二氧化硅薄膜，薄膜表面平整，颗粒度均匀，同时薄膜具有折射率精确可控和红外透射性能好的特点，非常适合制作光波导器件。     

Intracavity phase interferometry: frequency combs sensor inside a laser cavity

In traditional interferometric measurements, a physical quantity that changes the phase of a resonator is monitored through a change of its transmission. Interferometry inside a laser exploits the ultimate Q‐factor of that resonator, and converts the phase to be measured into a frequency. A mode‐locked laser with two intracavity pulses emits two frequency combs of the same repetition rate. The quantity to be measured (a sub‐nano displacement, a nonlinear index, an acceleration or rotation, a magnetic or electric field) produces a minute phase change ( rad) in one of the two intracavity pulses, which is converted into a frequency, measured by beating the two pulse trains emitted by the laser. This paper presents methods of operating mode‐locked lasers in which two independent pulses circulate, producing two frequency combs of the same repetition rate. Various examples of physical quantities that can be measured through this technique are presented.     

光纤压力传感器物理实验仪的研制

给出一个应用于光纤压力传感器物理实验仪的设计实例。给出了实际应用的框图,可使我们对光纤及传感器有所了解。     

激光半主动导引头光学系统分析

对陀螺-光学耦合式导引头中两种结构的光学系统进行分析,得出它们有不同的反射镜摆动角与跟踪场比,导出目标偏离视线的计算公式,并进行计算分析,最后讨论离焦探测器浸没问题。     

硅化铂肖特基势垒红外焦平面列阵及其发展

介绍PtSi肖特基势垒红外焦平面列阵的工作原理,分析探测器的最佳化结构,评述国内外肖特基势垒红外焦平面列阵的发展。     

Non-contact optical fibre phased array generation of ultrasound for non-destructive evaluation of materials and processes

The use of non-contact laser techniques for the generation of ultrasound has extended the limits of the application of traditional ultrasonic techniques. This paper focusses on the use of one such non-contact laser technique, known as ‘optical fibre array’, to generate shear and surface waves. The shear wave experimental directivity pattern results are presented and compared with the theoretical results of a single source and an array source. The experimental directivity results for the surface wave are also presented, and compared with the theoretical results. The data show that the array enhances signal generation in the forward direction for both shear and surface waves. The array gain is also discussed. The receiver for the directivity measurements was a contact piezoelectric transducer.     

Ti：LiNbO3光波导导模的场分布

给出了Ti扩散LiNbO_3条波导任意阶导模场分布的试探解.通过变分法分析,不但可以合理地确定其中的待定参数,而且也得到了相应导模传播常数的近似值.与扩展的有效折射率方法比较:这种解不但在函数形式上简单,待定常数确定方便,而且具有精度高的优点.还可以得到等效一维波导折射率分布的解析表达式.     

足球烯分子C_(60)及C_(70)的反饱和吸收性质与光限制效应

报道了对足球烯分子纯C_60及纯C_70的光限制效应的研究结果,讨论了样品的浓度及三重态寿命对光限制阈值的影响.首次报道在足球稀分子中发现的三重态吸收饱和现象,并阐述了其产生的原因及对光限制效应的影响.