微振动光电检测与数据采集系统的设计

提出了一种新的光学非接触式测量方法测量了物体的微振动振幅。用激光作为光源,以四象限硅光电池[1]作为光电探测器,借助三角测量原理,投射在振动源表面的激光反射光束在光电探测器上产生平面位移,将位移信号放大,通过A/D模块采集电压数值,并通过串口通信机制在PC终端实时显示。实验结果表明,该方法原理正确,灵敏度高,便于实现连续、快速、自动化检测,在工业在线检测方面具有良好的应用前景。     

Effect of Ag Doping on Optical and Electrical Properties of ZnO Thin Films

ZnO thin films were prepared on p-type Si (100) substrates by the sol-gel process. The influence of Ag doping at a content of 0.002% on the photoluminescence and current-voltage (I - V) characteristics of ZnO thin films has been investigated. It is found that Ag doping leads to a pronounced increase in the intensity of near band edge emission at 3.23eV and a remarkable red shift of the visible broadband at room temperature. The I - V characteristics of ZnO/p-Si heterojunctions are also changed. These results could be explained by Ag substituting for Zn in Ag doped ZnO thin films.     

Diode-Pumped Self-Q-Switched Cr,Nd：YAG Laser with High Average Output Power

A diode end-pumped self-Q-switched Cr,Nd:YAG laser was established with pulse duration in the range of 8-10ns. The maximum average output power was 4.4 W and the slope efficiency was 27% using an output coupler of R=70%. At pumping power of 17.4 W the laser produces high-quality pulses at 1064 nm in a TEMoo-mode.     

Structural and Electrical Characteristics of Pb（Zr0.53,Ti0.47）O3 Thin Films Deposited on Si （100） Substrates

Pb(Zr0.53, Ti0.47)O3 (PZT) films were directly deposited on Si substrates without a buffer layer by pulsed laser deposition. Only(110)-oriented PZT peaks (other than Si substrate peaks) were observed from the XRD data. The electrical properties of the PZT/Si capacitor were characterized in terms of both the capacitance versus voltage (C-V) and current versus voltage (I-V) measurements. The clockwise trace of the C-V curve shows ferroelectric polarization switching, as is expected. From the I-V curves, the Schottky emission and spacecharge-limited-current behaviour are found to be the mainly leakage current mechanism in a certain electric field range in the negative and positive bias, respectively.     

双脉冲电子束源实验

2MeV直线感应加速器注入器系统由电子束产生器和脉冲功率系统组成。电子束产生器包括由感应腔组成的阴极电压叠加器、阳极电压叠加器和真空二极管及束输运系统。脉冲功率系统则包含初级功率源Marx、次级功率源Blumlein线和触发系统，其作用是为感应腔提供一个具有数十纳秒平顶宽度的高压脉冲，激发感应腔在感应腔间隙上获得一个加速电场。在2MeV注入器功率系统中，4个Blumlein线的充气开关是由发散装置的输出触发信号进行导通控制的。通过控制发散输出触发信号到达Blumlein线开关的时间，即可以实现Blumlein线开关在不同时间内触发导通，使Blumlein线依据所设定的时间顺序输出激励脉冲，从而在真空二极管上获得高压脉冲串。由于功率系统采用的是182C结构，即一根Blumlein线驱动两个感应腔，因此最多可以实现四脉冲串列。     

Fabrication of Dendrimer－like PAMAM Based on Silica Nanoparticles

A G 4.0 dendrimer-like poly (amido amine) (PAMAM) based on silica nanoparticles was fabricated via a divergent approach.It was built from γ-aminopropyi silica nanoparfides (APSN) core via repetitive addition of acrylate (MA) and hexylenediamine (HDA). FT-IR and EA were used to monitor the progress of dendrimer during each step. The amino group content of the resulting product increased from 0.49 to 3.72 mmol/g after the 4th generation. In addition, the percentage of grafting increased with increasing generation and reached to 65.9% after 4th generation. It was found that the resulting silica nanoparticles could be dispersed in methanol with a mean hydrodynamic particle diameter of 152.7 nm although the silica nanoparticles had agglomerated during the storage period.     

激光器市场回顾与展望二极管激光器

《光机电信息》于2002年第4期报道了“激光器市场回顾与展望；非二极管激光器”的分析报告，经过数月的资料收集和市场调查，本期推出“激光器市场回顾与展望：二极管激光器”的分析报告。该报告对各种应用的二极管激光器的市场进行了分析，所给结果具有普遍意义。     

不断发展的CO2激光器

世界上第1台商用CO2激光器采用了一种很大的气体流动系统，需要定期维修和保养，而今天，CO2激光器已取得惊人的进展，人类正计划将一种体积小、重量轻并能连续工作5年的CO2激光器系统送往太空。     

激光器市场回顾与预测:非二极管激光器

根据几项全球性经济指标显示，全球激光器的销量已出现持续攀升的态势，其中主要原因之一是美国经济的复苏。美国目前仍然是激光器和光电子产品的最大市场。根据美同政府2003年11月发布的财政数字，2003年第3季度美国经济的年增长率为7．2％，国内生产总值的增长比自1984年第1季度以来的任何时期都快，并且是近3年中美国经济增速最快的一年。