Dielectrophoretic assembly of ZnO nanowires

The synthesis of zinc oxide （ZnO） nanowires is achieved by vapor phase transportation （VPT） method. The designed quartz tube, whose both ends are narrow and the middle is wider, is used to control the growth of ZnO nanowires. Dielectrophoresis （DEP） method is employed to align and manipulate ZnO nanowires which are ultrasonic dispersed and suspended in ethanol solution. Under the dielectrophoretic force, the nanowires are trapped on the pre-patterned electrodes, and further aligned along the electric field and bridge the electrode gap. The dependence of the alignment yield on the applied voltage and frequency is investigated.     

有机聚合物光波导的研制

聚合物光电子器件是目前世界范围的一个研究热点,其本身所具有易于集成、响应快速、成本低廉一系列优点,在光通信方面有广泛的和极具吸引力的应用前景。介绍了制作有机聚合物光波导的工艺流程,并用两种方法制备出有机聚合物光波导。这对后续研究有很大的帮助。     

Study of the behaviour of the fibre Bragg grating fabricated with cladding mode suppression fibre

One effective method for suppression of coupling from guided optical modes into cladding modes in an optical fibre Bragg grating is to use cladding mode suppression fibre. In this specially engineered fibre, the grating is written into the core and the inner cladding, both of which are photosensitive. A theory is presented in this paper to analyse the spectral characteristics of this kind of gratings. A fibre Bragg grating was experimentally fabricated with this kind of photosensitive fibre (PS-RMS-50 from StockerYale). It is shown both theoretically and experimentally that such gratings exhibit strong suppression of the coupling between core mode and cladding mode. The experimental result is in good agreement with the theoretical analysis.     

一种TEC温度控制模块的电路设计与仿真

为满足半导体激光器温度控制的要求,采用单个lm224放大器及若干电子元器件设计了一种高精度TEC温度控制电路,介绍了激光器温度控制模块的系统组成及工作原理,详细分析了TEC控制电路结构,采用pspice软件对电路做了仿真分析,建立了仿真模型并且介绍了仿真方法,仿真结果及实际测试表明此模块能够保证激光器稳定工作,控制精度为±0.1℃.该模块易于集成,工作温度范围宽且成本低廉,适用于多数半导体激光器中使用.     

如何鉴别劣质电风扇

在如今光盘录像机和DVD刻录机尚未普及的情况下．录像机以其能够录制电视节目且耗材低廉仍然受到人们的青睐。然而录像机说明书上的关于录制电视节目的说明不仅过程繁杂，而且介绍过于简单，加上专业术语较多，一般用户难以理解，真正能够自已录制电视节目的人寥寥无几．录像机的录制功能被闲置。为寻找一个简单易行的录制方法，笔     

气体放电强线光谱光源光通量分光测量法的研究

本文主要讨论了强线光谱气体放电光源的光通量分光测试法的有关问题，研究了单色仪狭缝宽度对测得的谱线相对强度分布及光通量的影响．并分析了分光法引起误差的原因，同时对不同狭缝宽度下测量光通量的稳定性作了分析和计算．     

A fiber Bragg grating current sensor with temperature compensation

A novel fiber Bragg grating （FBG） current sensor with temperature compensation has been proposed. The fiber Bragg grating is glued on the surface of an isosceles triangle cantilever beam, which has a step thickness along the beam axis. Due to the electromagnetic force created by a solenoid and a permanent magnet mounted on the top of the beam, a step strain is applied on the fiber Bragg grating. The change of the electric current in the solenoid makes the spectrum of the fiber Bragg grating split. By monitoring the shift difference of the two split center wavelengths, which is related to the electric current in the solenoid, a current sensor with temperature compensation is obtained. The test range of 0-400 mA is achieved. The experimental results also show that the relationship between the shift difference of the two split center wavelengths of the FBG and the electric current has a linearity of 0.9937, and the sensitivity is about 2.64 nm/A; the test results are independent of the temoerature, so the cross sensitive problem is solved.     

Electrochemical,thermal,and photophysical properties of novel two-photon absorption chromophores

Electrochemical, thermal, and photophysical properties of novel two- （BPODPA）, four- （BBPOPA）, and six-branch （TBPOA） triphenylamine chromophores are studied. The decomposition temperature of chro- mophores reaches 373 - 412 ℃. The electrochemical properties is explored by cyclic voltammetry. The ionization potential of chromophores is in the range of 5.14 - 5.18 eV. Excitation at 400 nm reveals emission peaks at 483 - 487 nm and the fluorescence quantum yields are 0.73 - 0.75 in CH2Cl2. Two-photon absorption （TPA） properties of chromophores are measured by nonlinear transmission method. The maximum TPA cross-section values are measured at 758 nm to be 20369 GM （1 GM=10^-50 cm^4 -s/photon） for TBPOA, 7024 GM for BBPOPA, and 1227 GM for BPODPA, respectively. When pumped with 800-nm laser irradiation, chromophores show strong two-photon excited blue-green fluorescence at 502 - 518 nm. These results provide a basis for understanding the electronic and optical properties of the conjugated multi-branch chromoohore in terms of the underlying molecular and electronic structures.     

DR19/PMMA掺杂型聚合物的电晕极化研究

极化聚合物以其响应速度快、制作工艺相对简单在聚合物集成光电器件领域得到了广泛的关注和研究.利用由大面积ITO玻璃、钨丝阵列以及金属栅格网组成的三层上电极结构,实现了DR19/PMMA掺杂型聚合物大面积均匀极化,并通过比较极化聚合物吸收光谱和以及反射法测量的电光系数,研究了极化电流、极化电压等极化参数对极化效果的影响.     

树枝状聚合物光捕获特性的研究进展

近年来，光捕获的特性除了在自然界同时也在许多树枝状聚合物分子上体现出来，并引起广泛关注。在讨论几种可能存在的能量传递机理前提下，总结了国内外近期对几种不同类型的树枝状聚合物光捕获特性的研究情况。发现不同的树枝状结构，能量转移的机理是不同的。而其中大部分的试验研究结果认为，F6rster机理是主要的。这些研究工作将对我们进一步研究树型分子材料，模拟自然界中的能量传递过程以至发展新型的光子器件有相当大的指导意义。