高气密性的深紫外LED半无机封装技术

深紫外LED可通过物理方式破坏病毒和细菌的结构，从而获得高效消毒的效果。相比于工艺成熟的蓝光LED，如何提高深紫外LED的封装可靠性和出光率仍是关键问题。本文采用基底预热方式微固化封装胶，结合阵列点胶方式将石英玻璃固定在镀铜围坝，制备了半无机封装的深紫外LED。该器件的输出波长为275 nm，半峰宽约为11 nm。对比传统类透明材料封装的器件，石英封装的深紫外LED有更高的出光率。在真空红墨水和氦气漏率实验中，采用本文提出的半无机封装技术的深紫外LED器件表现出高密封性。此外，在加速老化测试中，该封装器件的光衰速率在20%以内。实验结果表明，对比有机封装的深紫外LED器件，在基底预热条件下，采用阵列点胶固定石英玻璃是现阶段提高深紫外LED可靠性的一种封装方法。     

透镜对1W白光LED参数的影响

研究了透镜对1W白光LED光强空间分布、光通量和色温光参数的影响。研究结果表明,透镜是1W白光LED光强空间分布的决定因素,透镜的存在和选择性吸收导致1W白光LED发光效率和色温值下降。根据研究结果提出了一种不使用透镜的硅胶倒模封装形式,该封装形式的1W白光LED发光效率比有透镜时提高了6%~7%,且可以使用波峰焊和回流焊方式进行焊接。     

X光CCD响应特性研究

 在北京同步辐射源上建立了X光CCD(Charge-Coupled Device)量子效率实验标定方法，获得了150eV至1500eV能区范围多个X光能点的量子效率实验结果，发展了X光CCD量子效率简化计算模型，并对X光CCD表面油沾污对量子效率的影响进行了实验研究和修正。结果表明经过油沾污修正后的简化理论模型计算结果与实验标定结果符合较好。     

封装对φ5白光LED寿命的影响研究

为了确定不同封装材料对φ5白光LED光衰的影响程度,对封装用芯片、键合材料、荧光粉、硅胶和环氧树脂进行了对照分析。研究结果表明:芯片质量是关键;键合材料、荧光粉和外封装环氧树脂对光衰的影响相对较弱;使用普通环氧树脂配粉,导致φ5白光LED寿命只有硅胶配粉φ5白光LED寿命的1/7,环氧树脂配粉胶对白光LED寿命的影响非常大。由高质量芯片和高性能的环氧树脂配粉胶封装成的φ5白光LED,在连续工作1200h后,其光衰小于5%。     

PbS量子点在荧光集光太阳能光伏器件上的应用

荧光集光太阳能光伏器件在平面光波导效应的作用下实现等效聚光,可以减少太阳能电池的用量,有效降低光伏发电的成本。将胶体化学法制备的吸收和发射在近红外波段的单分散球状PbS量子点荧光材料封装于两片光伏超白玻璃间的正己烷溶液中,构成溶液夹层封装的平面光波导,并和效率为17%的单晶硅太阳能电池耦合,制作出了吸收在700～1000nm,效率约为1.31%的近红外荧光集光太阳能光伏器件。     

铝/氧化铝复合基板封装的LED光源的光热特性

为获得具有高出光效率、高导热性能的发光二极管(LED)封装基板,采用直接敷铝(Al)工艺制备了铝/氧化铝(Al_2O_3)复合陶瓷基板并对其表面进行化学机械抛光处理。运用光学模拟软件Tracepro和热学模拟软件ANSYS对该陶瓷基板封装的LED光源的光学性能和热学性能进行了模拟计算,并和传统氧化铝陶瓷基板封装的LED光源进行了对比分析,最后将所制备的铝/氧化铝陶瓷基板封装成板上芯片直装(COB)型LED光源进行测试。模拟和实验测试结果均表明:直接敷铝工艺制备的铝/氧化铝陶瓷基板热传递速度更快,导热性能更加优异,更适合用于大功率LED光源的封装;铝/氧化铝陶瓷基板封装的的LED光源比基于传统氧化铝陶瓷基板的LED光源的光通量大,出光效率更高。     

BGO晶体光输出性能的研究

本文报道了BGO晶体荧光收集的实验研究. 结果表明, 与光电倍增管耦合的晶体的表面粗糙可以提高光收集效率.     

等离子体尺寸对放电极紫外光源影响

计算了放电等离子体极紫外光刻光源中,不同等离子体长度条件下的收集效率,实验上研究了等离子体长度对Xe气放电极紫外辐射的影响。结合本系统光学收集系统设计参数和理论计算结果,给出了不同等离子体长度条件下中间焦点处13.5 nm（2%带宽）光功率。结果表明等离子体长度为3~6 mm时毛细管光源中间焦点光功率和尺寸最优。     

光电导过程中陷阱的影响

从理论上提出光折变材料中光电导过程的陷阱作用机制，给出了载流子的光激发，复合及俘获过程的动力学方程，得到了陷阱作用下的光生量子效率的解析表达式，实验上，对掺杂不同浓度的Ｃ６０（Ｃ７０）的ＰＶＫ薄膜的光生载流子量子效率随光强度的变化关系进行了测量，得到了与理论预测相一致的结果。     

阵列式微型透镜封装多芯片COB LED的光学仿真设计及应用

为了提高COB LED的取光率,以1919 COB LED为研究对象,建立阵列式圆锥透镜、半椭球透镜、四棱锥透镜和半圆球透镜封装LED模型,并利用光学仿真软件进行研究。仿真实验结果表明:在优化条件下,高0.5 mm、直径0.9 mm的阵列圆锥透镜封装LED的光通量由平面封装的67 lm提高至84.3 lm,即取光率提高25.8%。制作了RGB芯片的多芯片LED样品,并用直径1 mm的阵列半圆球透镜进行封装,其取光率提高18.8%。     

多次漫反射法测量粉末中的杂质吸收光谱及其计算机模拟

本文提出了用多次漫反射法来测定粉末样品的杂质吸收光谱,其结果与同材料的透明片状样品的杂质吸收光谱基本一致,为了验证更普遍的对不同折射率粉末情况,文中采用假设模型,以计算机模拟方法,其所得的结果说明,当颗粒足够小,色散又不太大时,所得的粉末样品与透明片状样品的吸收光谱一致,只差一个未知的吸收光程,如再与另一特性参数(寿命或量子效率)测量相结合,即可用来确定稀土杂质在材料中的辐射跃迁几率等物理参数。     

一种新型光学渡越辐射光学特性的测量方法

为了解决理论测量中,光学渡越辐射焦平面的空间角分布与像平面的束剖面光路互相影响,难以同时测量,提出了一种新型的光学渡越辐射光学特性的测量方法.介绍了其光路原理和结构方案,分析了测量结构中的OTR镜头、分光棱镜与铅屏蔽结构的技术难点与解决方法.结果表明：系统克服了单功能测量、成像质量差等缺点,在ICCD相机上能够同步获得较好的光学渡越辐射的束剖面和空间角分布图案,且基本屏蔽了对图像采集有着强烈干扰的X-射线等高能辐射.     

基于Mie光散射理论的尾流气泡前向散射光特性研究

实验中利用CMOS图像传感器代替传统的光电探测器接受前向散射光,由几何光学和图像处理分析得出不同散射角的散射光与采集图像中的光环相对应.通过计算各个光环的所有像素值的总和就可以得到前向散射光光强的相对值,进而可以得出前向散射光光强变化规律.根据米氏（Mie）光散射理论可以计算出气泡各个方向的散射光光强,通过比较实验结果和Mie理论计算结果可以看出,采用CMOS图像传感器探测和图像处理技术可以准确地得出散射光强度的变化规律.     

The Measurement of the Separation of Fine Solid Particles in Multiwir Packings

In this paper, a new type of packing for the separation of solid particles from gases is presented. The so called Multiwir (multiple vortex) [1, 2] packings (see Figure 1) consist of multiple adjacent layers of strips spaced uniformly. As the layers are placed oblique to each other, the incoming gas stream passes the packings in the form of a large number of smaller streams which cross each other spatially and thus induce rotational motion in each other. Under centrifugal forces and due to turbulent and electrostatic effects, the particles settle on the surfaces of the strips where they are collected. In this paper, some of the experimental results are described obtained in the investigation of Multiwir-packings, consisting of metal or plastic strips, with different limestone aerosols and feed particle size distributions with particles smaller than approximately 3 μm and 10 μm. The following results have been obtained: — the Multiwir separator should be used for the removal of fine particles. Particles smaller than 10 μm in size can only be collected if special precautions are used, — the efficiency of the separator is dominated by the gas velocity, the geometry of the packing, the material of the strips and the size distribution of the feed material, — the smaller the feed particles are, the smaller the distance between adjacent strips should be, — the reduction of the distance between adjacent strips is limited however by an increase of the pressure drop across the packing, — adhesion between particles and strip surface strongly influences the performance of the packing. The surface of the strips should therefore be wetted, for example with a thin oil film, — the collection of small particles can be further improved if the feed particles are charged electrostatically in front of the packing, — the total grade efficiency of the packings investigated lies between T₀ = 0.6 and 0.9. Extremely good results have been obtained with perforated plastic strips. Simplified mathematical models have been used to describe the phenomenon of particle deposition in Multiwir packings due to inertia effects and turbulent diffusion.     

The effect of determined chaos on light collection in optical systems

In terms of the dynamic approach, the collection of light in optical systems and the influence of determined chaos on the photometry and fluctuations of regular and chaotic collection are considered. The photometric relationships generalizing the formula of the integrating sphere as applied to chaotic collection are obtained. A universal law for noise in the regular light collection is predicted and found to be in good agreement with the available experimental data. The relationships studied can find use in the elaboration of a new-design detectors, light guides, light-emitting diodes, etc., for the enhancement of their efficiency and the reduction of noise.     

Accurate depolarization ratio measurements for all diatomic hydrogen isotopologues

The Raman depolarization ratios for individual Q₁(J”) branch lines of all diatomic hydrogen isotopologues – H₂, HD, D₂, HT, DT, and T₂ – were measured, for all rotational levels with population larger than 1/100 relative to the Boltzmann maximum at room temperature. For these measurements, the experimental setup normally used for the monitoring of the tritiated hydrogen molecules at KArlsruhe TRItium Neutrino experiment was adapted to optimally control the excitation laser power and polarization, and to precisely define the Raman light collection geometry. The measured Raman depolarization values were compared to theoretical values, which are linked to polarizability tensor quantities. For this, the ‘raw data’ were corrected taking into account distinct aspects affecting Raman depolarization data, including (1) excitation polarization impurities; (2) extended Raman excitation volumes; and (3) Raman light collection over finite solid angles. Our corrected depolarization ratios of the hydrogen isotopologues agree with the theoretical values (based on ab initio quantum calculations by R.J. LeRoy, University of Waterloo, Canada) to better than 5% for nearly all of the measured Q₁(J”) lines, with 1σ confidence level. The results demonstrate that reliable, accurate Raman depolarization ratios can be extracted from experimental measurements, which may be substantially distorted by excitation polarization impurities and by geometrical effects. Copyright © 2013 John Wiley & Sons, Ltd.     

天空光光谱监测大气污染的参考光光谱研究

本文研究了利用天空光光谱反演大气成分的方法中,参考光谱对测量结果的影响。分析了中午的天顶光光谱、实时采集的天顶光光谱对信号的影响,提出了针对空间任意方向的大气污染(尤其局部的突发性污染),实时采集的低污染区天空光光谱是具体研究污染最合适的参考光谱。其结果为将该方法应用于监测大气环境提供了依据。     

Optical properties of composites with nanodimensional oxide coatings versus the properties of film-forming sols. I. The influence of sol’s oxide composition

The influence of the aging period (duration) and the aging-related rheological characteristics of film-forming solutions (sols) on the refractive index and thickness of coatings, light reflection and light transmission coefficients, and optical losses in glass substrate-nanodimensional oxide (CuO-TiO₂) composites is considered. It has been shown that the increase in the CuO concentration in the coating and the extension of the sol aging period favor crystallization and change the form of inclusions in the coating from pseudospherical to dendritic with a different degree of branching. The refractive index of the film and its related coefficient of mirror reflection of the composite are functions of the density of packing sol disperse-phase particles into a nanodimensional layer. The packing density of dendritic particles drops decreases with the degree of their branching and transverse size of fragments. In every case, an optimal sol aging period should be found to obtain glass composites with nanodimensional coatings offering desired optical properties.     

活塞圆筒容器中铁磁居里温度的一种测量方法

 本文介绍了在活塞-圆筒型装置中建立的高压下原位测量居里温度的方法。采用简单的测量电路，不需要锁相放大器等精密仪器，系统仍具有较高的灵敏度，足以满足测量小样品的要求。合理的高压组装结构保证了测量的成功率。实验结果表明，测量的重复性误差小于±1 ℃。     

TiO2和SiO2薄膜应力的产生机理及实验探索

对最常用的TiO₂和SiO₂薄膜应力, 包括应力模型、应力测试方法和不同实验条件下的应力测试结果作了研究.基于曲率法模型，对TiO₂和SiO₂单层膜和多层膜进行了实验测试，得到了一些有价值的结果，特别是离子辅助淀积和基板温度等工艺参数对薄膜应力的影响.提出了薄膜聚集密度是应力的重要因素，低聚集密度产生张应力，而高聚集密度产生压应力.在多层膜中通过调节工艺参数，适当地控制张应力或压应力，可使累积应力趋向于零. 关键词： 薄膜应力 离子辅助淀积 聚集密度