Development of a new diindenopyrazine–benzotriazole copolymer for multifunctional application in organic field-effect transistors,polymer solar cells and light-emitting diodes

A new donor–acceptor (D?A) copolymer (PIPY–DTBTA) containing 6,12-dihydro-diindeno[1,2-b;1′,2′-e]pyrazine donor and benzotriazole acceptor was synthesized and characterized for multifunctional applications in organic field-effect transistors (OFETs), polymer solar cells (PSCs) and polymer light-emitting diodes (PLEDs). The polymer exhibits high molecular weights, excellent film-forming ability, a deep HOMO energy level, and good solution processability. Solution-processed thin film OFETs based on this polymer revealed good p-type characteristic with a high hole mobility up to 0.0521 cm² V^?1 s^?1. Bulk-heterojunction PSCs comprising this polymer and PC₆₁BM gave a power conversion efficiency (PCE) of 0.77%. The single-layer PLEDs based on PIPY–DTBTA emitted a yellow–red light with a maximum brightness of 385 cd m^?2 at the turn-on voltage of 6 V.     

腔内倍频Nd3+:GdVO4/LBO深蓝456 nm激光器的工作特性

在激光二极管(LD)抽运腔内倍频Nd3 :GdVO4/LBO深蓝456 nm激光器中.为对比激光品体掺杂浓度对倍频输出功率的影响.利用同样尺寸为3 mm×3 mm×2 mm,稀土离子掺杂原子数分数分别为0.15和0.25的Nd3 :GdVO4品体作为对比.实验中利用同样长为20 mm的线性直腔,在使用10 mm长、按基频光为914 nm方向切割的Ⅰ类相位匹配倍频晶体LBO,在抽运功率为2.85 w时,前者获得了输出率为105 mW的深蓝456 nm激光,明显高于后者.通过对准三能级激光晶体的最佳长度分析表明,掺杂原子数分数为0.15的Nd3 :GdVO4晶体与0.25的相比,其实际长度更加接近于最佳长度.通过对倍频晶体LBO的最佳切割角和温度控制等分析表明,利用针对914 nm基频光切割的LBO晶体在912 nm激光器中.其切割角的差别可以通过温控的改变得到补偿.     

图像脉冲噪声的模糊检测与消除

论述了基于模糊规则的脉冲噪声滤波器。该滤波器由模糊脉冲噪声检测器、噪声消除器与模糊结合器构成。模糊脉冲噪声检测器用窗口风的中值与邻近像素信息来检测脉冲噪声,而脉冲消除器用最小值算法来计算噪声像素的估计值。与传统的脉冲噪声滤波器相比较,所设计的新滤波器具有良好的脉冲噪声抑制与图像细节边缘保护的性能。     

一种克服色度色散影响的四倍频光毫米波信号产生方法

提出一种克服色度色散影响的四倍频光毫米波信号产生方法。该方法使用一个双驱动马赫曾德尔调制器,通过调整上、下两路射频信号的相位差、直流偏置点、调制系数以及基带信号增益,将数据信号仅调制到四倍频光毫米波信号的一个2阶边带上传输,解决了色度色散引起的码元走离问题,有效增加了传输距离。理论分析和仿真实验结果表明,信号在光纤中传输120 km后眼图仍然十分清晰,经过60 km传输后的功率代价约为0.45 dB。另外,基于频率再用技术,没有调制数据的另一个2阶边带信号还可以作为全双工光纤无线通信(RoF)系统的上行链路光载波,简化了基站配置。仿真实验结果表明,双向2.5 Gbit/s数据信号在光纤中传输40 km后,功率代价小于0.6 dB。     

大功率医用全固态561nm黄光激光器

采用半导体抽运腔内倍频的方法,获得了可满足医疗应用的瓦级全固态561nm黄光激光输出。在比较和分析了Nd…YAG激光晶体各主要谱线的激光参数之后,通过谐振腔膜系的设计抑制了增益较大的1064,1319和946nm谱线的运转。通过对倍频晶体的合理选择以及晶体放置角度与匹配温度的合理控制,在13.5W的808nm抽运功率下,实验获得了1.41W的561nm单一谱线的黄光激光输出,光-光转换效率为10.5%。     

液晶显示器Mura缺陷及测量方法浅析

Mura缺陷是液晶显示器(LCD)中常见的不良现象,直接影响到显示图像质量.本文对液晶显示器Mura缺陷进行了详细的综述,首先概述了Mura缺陷的种类及主要来源,然后介绍了Mura缺陷的三类测量方法:人工视觉识别法、电学测量法、光学测量法.人工视觉识别法利用滤光片观察样品,成本较低,但无法做到客观的评定产品等级;电学测量法适用于电气缺陷造成的Mura;基于机器视觉的光学测量法是当前研究的热点,对于各种原因造成的Mura缺陷均具有良好的检测效果.详细分析了各种检测方法的特点,最后进行归纳总结.     

基于波数域积分的人体表面微波三维成像算法研究

该文给出了人体表面微波3维成像所需要满足的采样准则,提出了基于波数域积分3维成像处理方法,该方法通过在给定距离单元上沿波传播方向上的波数域积分代替了复杂的3维STOLT插值。通过计算机仿真给出了由点目标组成的人体模型的3维重建图像,利用通用仪器构建的人体微波3维成像实验系统开展童装模特的微波暗室Ka波段3维成像实验,验证了成像处理方法的正确性和有效性。     

Flexible Electronics: Thin Silicon Die on Flexible Substrates

Silicon thinned to 50 mum and less is flexible allowing the fabrication of flexible and conformable electronics. Two techniques have been developed to achieve this goal using thinned die: die flip chip bonded onto flexible substrates [polyimide and liquid crystal polymer (LCP)] and die flip chip laminated onto LCP films. A key to achieving each of these techniques is the thinning of die to a thickness of 50 mum or thinner. Conventional grinding and polishing can be used to thin to 50 mum. At 50 mum, the active die becomes flexible and must be handled by temporarily bonding it to a holder die for assembly. Both reflow solder and thermocompression assembly methods are used. In the case of solder assembly, underfill is used to reinforce the solder joints. With thermocompression bonding of the die to an LCP substrate, the LCP adheres to the die surface, eliminating the need for underfill.     

一种可免用光隔离器的抗反射同轴激光器TO-CAN

文章提出了一种不用光隔离器即可提高器件抗反射性能的抗反射同轴激光器TO-CAN(晶体管外形封装), 该TO-CAN集成了半导体激光器的电/光信号转换功能和抗反射功能,采用现有的贴片工艺和粘胶工艺,通过在底座TO-Header(晶体管外形头)上面安装激光器芯片、偏振片和λ/4波片而制成,理论分析和实验结果都验证了该方案的有效性和实用性.     

Highly (1 0 0)-oriented Pb(Zr0.20Ti0.80)O3/(Pb1−xLax)Ti1−x/4O3 multilayered thin films prepared by RF magnetron sputtering

The Pb(Zr_0.20Ti_0.80)O₃/(Pb_1−xLa_x)Ti_1−x/4O₃ (x = 0, 0.10, 0.15, 0.20) (PZT/PLT_x) multilayered thin films were in situ deposited on the Pt(1 1 1)/Ti/SiO₂/Si(1 0 0) substrates by RF magnetron sputtering technique with a PbO_x buffer layer. With this method, all PZT/PLT_x multilayered thin films possess highly (1 0 0) orientation. The PbO_x buffer layer leads to the (1 0 0) orientation of the multilayered thin films. The effect of the La content in PLT_x layers on the dielectric and ferroelectric properties of the PZT multilayered thin films was systematically investigated. The enhanced dielectric and ferroelectric properties are observed in the PZT/PLT_x (x = 0.15) multilayered thin films. The dielectric constant reaches maximum value of 365 at 1 KHz for x = 0.15 with a low loss tangent of 0.0301. Along with enhanced dielectric properties, the multilayered thin films also exhibit large remnant polarization value of 2P_r = 76.5 μC/cm², and low coercive field of 2E_c = 238 KV/cm.