用于测量金属板厚的电光双稳光纤传感法

光纤传感法测量金属薄板厚度中,引入了电光双稳装置,以增强光强的稳定性、提高测量精度．实验表明,干涉法不宜采用多模光纤,而改用反射式强度调制型多模光纤传感器,亦可得到位移和光强的关系曲线以及满意的测量结果．     

光照度对光纤环绕制图像清晰度影响分析

在视觉测量技术中光照度是照明系统中的一个重要参数,选取合适的光强对视觉测量系统至关重要。为了进一步确定光纤检测系统的最佳光强,将针对不同光强对图像质量及系统的检测精度产生影响展开研究。首先通过调制光源电源模块产生十种不同的光照度,然后利用五种清晰度函数分别评价各个光强下采集光纤环图像的清晰程度,并计算每幅图像中对应点的光纤直径测量误差以确定检测精度。实验结果显示:当光通量为200 lm时,图像的清晰度最佳,系统的检测精度最高。研究通过优化光照度有效地提高了系统的精度,同时为搭建视觉测量系统时选择合适的光照度提供了一定的参考价值。     

光纤耦合技术在红外激光照明器上的应用

光纤耦合技术可以把LD半导体技术和双包层光纤掺杂技术有机地结合起来,吸收二者的优势,实现高功率、高亮度、衍射受限的激光输出。主要研究了光纤耦合技术在红外激光照明器上的应用,实现了对照明效果的影响。实验结果表明光纤耦合技术可以显著改善光斑的均匀性,大幅度提高输出的光功率。     

一种基于保偏光纤干涉结构的稳定光谱测量方法

本文提出一种用于光谱测量的保偏光纤干涉结构.该结构基于保偏光纤、法拉第旋转镜、偏振分束器和保偏光环形器等光纤器件的.结构中采用的压电陶瓷光纤相位调制器,使干涉工作在光程线性调制区域,以减小压电陶瓷非线性光程调制产生的误差.结构中的法拉第旋转镜、保偏光纤及保偏光器件的结合使用保证了传输光的偏振稳定性,消除偏振衰落效应的影响,保证了稳定的光谱测量结果.实验测试了SLD光谱,测得结果和光谱仪测得结果一致,结果表明该系统测量光谱的稳定性.该系统可用于提供光纤传感器和通信应用中常用光源(如二极管激光器、LED和半导体激光器等)的光谱分析.     

Measuring Fiber Orientation in Nonwoven Fabrics by Laser Scattering Method PartⅠ Principle and Instrumentation

The scattering performance of a parallel laser beam onthe parallel fiber model and nonwoven fabrics are studiedin detail. A device of computer - program - controlledsystem for measuring laser scattering intensity - angledistribution function of fiber assemblies is set up, and themeasuring condition for distingulslhing the fibers ar-ranged at different directions is carried out. The materi-als of two categories, the models of fiber assembly andnonwoven fabrics made with varied processing methods,are studied. The analysis and experiments show that thefiber orientation distribution functions in the 2 - dimen-sional fiber assemblies can be sensitively determined bylaser scattering method.     

流化床光反应器中光强波动信号的测量

针对流化床光反应器中光强的测量问题,研制了一种高灵敏度的光导纤维光强传感系统,并对外部平行光源平板流化床光反应器中光强的分布及其波动规律进行了研究。结果表明:在外部平行光源照射下平板流化床中光沿径向呈指数衰减;液-固流化床与三相流化床中光强信号的波动规律不同,三相流化床中光强信号的功率谱密度图在5~12 Hz处出现谱峰。该测量系统结构简单,操作方便,适合各种流态化光反应器床层内部光强信号的测量。     

Handheld optical coherence tomography device for photodynamic therapy

Photodynamic therapy (PDT) is a very effective treatment for port wine stains (PWS). To guide and assess PDT treatment, a handheld optical coherence tomography (OCT) probe was designed for real-time imaging of the PWS patient. The system uses a light source with a center wavelength of 1310 nm, -3 dB bandwidth of 90 nm and an optical power of 9 mW. The system also has a spatial resolution of 8 μm (lateral) × 7 μm (axial), an imaging rate of 4 frames per second, and a 102 dB sensitivity. We then demonstrate that the OCT imaging system can clearly distinguish between normal and PWS tissues. Therefore, the system can provide valuable guidance for PDT treatment.     

用于裂隙光源的侧面发光塑料光纤散射点设计

设计一种侧面发光塑料光纤表面正四棱锥形微结构散射点，使侧面发光塑料光纤可用作裂隙灯显微镜的裂隙光源，以减小裂隙光源的体积.采用光学仿真软件分析光纤上表面(有散射点)和光纤下表面(无散射点)的散射率，当塑料光纤直径为1 mm时，得到优化后的正四棱锥散射点的底边宽度和深度均为80μm.仿真结果表明，光纤下表面散射光的光束发散角在垂直于光纤方向约为40°,在平行于光纤方向约为110°,经过焦距为50 mm的投射镜会聚后的光带宽度约为0.3 mm,可以满足裂隙灯显微镜的要求.     

光纤照明光源发生器的设计与制作

采用金属卤化物作发光物质,将发光管设计成球泡形状,给出了金属卤化物发光管的结构及制作工艺;将光学界面设计为椭球形状,采用3个不同中心波长的λ/4膜堆叠加而成的多层介质膜系对反射聚光器进行镀膜,从而获得所需要的高反射波长区域.将发光管和光学界面精确定焦,使出射光束均匀聚焦到光纤首端面,提高了光纤照明系统的发光效率.测试结果表明:设计制作的100W和150W的两种光纤照明光源的稳定性好、寿命长.     

多模光纤斑纹场及其应用

本文研究了He-Ne 激光照明的单根多模阶跃折射率型光纤及多模光纤束产生的斑纹场的特性,讨论了不同芯径的光纤组成的多模光纤束产生的斑纹场之间的差别,并将它们与毛玻璃板斑纹场进行了比较.通过实验验证了所得结论的正确性,证明了多模光纤束辐射的斑纹场可以用于光学测量和信息处理.     

Structured illumination microscopy for super-resolution and optical sectioning

Optical microscopy plays an essential role in biological studies due to its capability and compatibility of non-contact, minimally invasive observation and mea- surement of live specimens. However, the conventional optical microscopy only has a spatial resolution about 200 nm due to the Abbe diffraction limit, and also lacks the ability of three-dimensional imaging. Super-resolution far- field optical microscopy based on special illumination schemes has been dramatically developed over the last decade. Among them, only the structured illumination microscopy （SIM） is of wide-field geometry that enables it easily compatible with the conventional optical microscope. In this article, the principle of SIM was introduced in terms of point spread function （PSF） and optical transform function （OTF） of the optical system. The SIM for super-resolution （SIM-SR） proposed by Gustafsson et al. and the SIM for optical sectioning （SIM-OS） pro- posed by Neil et al. are the most popular ones in the research community of microscopy. They have the same optical configuration, but with different data post- processing algorithms. We mathematically described the basic theories for both of the SIMs, respectively, and pre- sented some numerical simulations to show the effects of super-resolution and optical sectioning. Various approaches to generation of structured illumination patterns were reviewed. As an example, a SIM system based on DMD- modulation and LED-illumination was demonstrated. A lateral resolution of 90 nm was achieved with gold nanoparticles. The optical sectioning capability of the microscope was demonstrated with Golgi-stained mouse brain neurons, and the sectioning strength of 930 nm was obtained.     

城市微区电波传播特性研究

阐述了一种三维电波传播模型来预测城市环境下的传播损耗．该模型建立在几何光学理论和几何绕射理论的基础上,模型考虑了地面和墙壁的反射,建筑物墙角和屋顶的绕射,计算出非视距区域的路径传播损耗     

Photoinduced effects in amorphous semiconductor Ge(S, Se)2 chalcogenide films

The blue shift of optical transmittance edges were observed in amorphous semiconductor Ge(S, Se)2 chalcogenide films with light illumination. The shift in well-annealed films could be recovered by annealing the films near the glass-transition temperature again. The photocrystallization was also observed in amorphous Ge(S,Se)2 films with light illumination by the transmitting electron microscope measurement. The photoinduced phenomina of the amorphous Ge(S,Se)2 films could be applied to designing some new kinds of optical storage materials.     

纤维织物和耐烧蚀填料对硅橡胶涂覆织物性能的影响

为研制防隔热效率更高的耐烧蚀硅橡胶涂覆织物,采用不同种类的纤维织物和耐烧蚀填料制备出多种新型硅橡胶涂覆织物,并分别研究了纤维织物种类、耐烧蚀填料种类和用量对硅橡胶涂覆织物力学性能和烧蚀性能的影响。实验结果表明:当选用碳纤维布(T300)作为增强骨架材料时,硅橡胶涂覆织物的烧蚀性能最优;随着耐烧蚀填料添加量的增大,硅橡胶涂覆织物的邵氏A硬度逐渐增大,其拉伸强度和断裂延伸率均呈现出先升高后降低的趋势;综合考虑力学性能,耐烧蚀填料的最佳用量为2 g/100 g;耐烧蚀填料能有效提高硅橡胶涂覆织物的烧蚀性能,其中酚醛纤维和黏胶基碳纤维的增强效果更好。     

光纤数值孔径的自动测量

本文介绍的测量装置采用TP801单板机控制检测器转盘,可自动进行角度扫描,描绘远场光分布曲线;同时可对测出的数据进行处理,计算数值孔径,并在单板机上显示。     

克服光纤色散影响的技术

阐述了光纤色散与光源,光脉冲展宽间的关系,以及克服光纤散影响的技术,重点介绍采用色散补偿光纤与呆调调啁咪光栅补偿器件的实用技术。     

提高幅值型光纤传感器稳定性的方法

幅值型光纤传感器光源的不稳定性及光电器件的温度特性会引起较大的测量误差。本文详细地介绍了提高光源稳定性的方法，并叙述了有效的温度补偿电路。     

Colloidal semiconductor nanocrystals for biological photodynamic therapy applications: Recent progress and perspectives

Photodynamic therapy (PDT), due to the high level of reactive oxygen species (ROS) and induced oxidative damage to proteins, lipids, DNA, and dysfunctions in cell metabolism, has exhibited its potential applications in anti-tumor and anti-bacteria biological applications. Photosensitizers (PS) are very necessary to achieve high PDT efficiency. Colloidal semiconductor nanocrystals (CSNCs) are increasingly utilized as emerging photosensitizers and adjuvants in PDT. They have many optical and chemical advantages such as narrow, symmetric and size-tunable emission spectra, stable fluorescence, broad absorption spectra, high level of brightness and photostability, large stokes shift, and easily functionalized with biological groups or molecules. Therefore, great interests have been received for CSNCs in constructing a PDT platform for cancer and bacterial behavior study even having the possible side effects, for example, the excitation light is mostly concentrated in the ultraviolet region, and the toxicity mechanism is not clear. This review mainly focuses on the recent progress of CSNCs-based PDT research for cancer cells and bacterial cells killing both in vivo and in vitro. From the perspective of the efficiency of PDT, the medicine, materials science and nanotechnology, as well as the representative works are summarized, and CSNCs with special functions are discussed. This review emphasized on the relationship between structure/composition and performance of PDT-based CSNCs. Meanwhile, the critical and potential issues and future perspectives are also addressed.     

Photoinduced effects in amorphous semiconductor Ge(S, Se)2 chalcogenide films

The blue shift of optical transmittance edges were observed in amorphous semiconductor Ge(S, Se)₂ chalcogenide films with light illumination. The shift in well-annealed films could be recovered by annealing the films near the glass-transition temperature again. The photocrystallization was also observed in amorphous Ge(S,Se)₂ films with light illumination by the transmitting electron microscope measurement. The photoinduced phenomina of the amorphous Ge(S,Se)₂ films could be applied to designing some new kinds of optical storage materials.     

基于TracePro的发光二极管均匀照明光源设计

基于光学原理的三维无损测量在工业生产过程中被广泛应用,论文采用光学仿真模拟软件Tracepro进行照明光源的模拟仿真,在保证光照强度的同时,实现图像采集方案对光照均匀度的要求。通过分析光源的排列方式、层数,照射角度以及照射角度与实际被测场景的对应调整关系,确定各因素对光照均匀度的影响。通过仿真分析可得,在半径200mm的圆形设定视场内,当光源以四层正六边形排布,在与被测物垂直距离为500mm,照射角度为9°时,光照均匀度达到94.67%。根据仿真结果进行照明系统构建并进行实验,实验结果与仿真结果相符合。