一种钛宝石激光器自触发脉冲氙灯预燃开关电源

介绍了一种新型实用的自触发低功耗氙灯高压预燃开关电源。该预燃电源输出电流小,无需高压脉冲发,可有效防止氙灯灭弧,这不仅增加了系统的可靠性,而且对延长氙灯的寿命起到了非常重要的作用。     

点燃氙灯的倍压预燃电路

为了解决高气压闪光灯预燃中的特殊困难,我们将倍压预燃电路用于我所研制的20次/秒机载激光器的电源上,收到了较好的效果。预燃电路如图1所示。电源以400赫兹、115伏供电,也可以直流27伏逆变供电。平时,电路以四倍压的高压加在氙灯两端。触动开关K,电容C经K及脉冲变压器B2的初级线圈放电,次级产生一高压去触发氙灯。氙灯激励后,由D1、D2、C1、C2、R1、R2组成的二倍压通过D3、D4、D5、R维持氙灯处于正常的预燃状态,这时C4被短路。     

半绝缘GaAs光电导开关的光控预击穿特性

用波长1064nm,触发光能为0.5mJ的激光脉冲触发电极间隙为4mm的半绝缘（SI）GaAs光电导开关,当偏置电压达到4kV时,开关并未引发自持放电,而是进入非线性（lock-on）工作模式,即开关处于光控预击穿状态。分析认为：通过激子的产生和离解激子效应贡献了光电导;碰撞电离、雪崩倍增、激子效应补充了因外界光源撤出后所需的载流子浓度和能量。在上述因素的相互作用下,SI-GaAs 光电导开关并没有引发自持放电而是处于光控预击穿状态,丝状电流特性影响着开关的损伤程度。     

Nd:YAG激光电源预燃触发系统

针对 Ｎｄ∶ Ｙ Ａ Ｇ 激光电源的特点, 研制出了一种可靠预燃触发网络系统。氪 （ Ｋｒ） 灯被触发后, 经过一个小电流的缓冲放电, 它类似于一般预燃放电; 但无需长时间保持预燃电流。该预燃网络功耗显著降低, 在低重复率的固体 Ｎｄ∶ Ｙ Ａ Ｇ 激光电源工作中, 其优越性表现得更加完美。     

印刷电路板预电离TEA CO2激光器的阴极表面预电离研究

弧光放电不利于TEA CO2激光器输出高功率激光,通常采用预电离技术来获得主电极间的均匀辉光放电。印刷电路板预电离较其他紫外光预电离方式具有更好的预电离强度和预电离均匀性的结合,有利于产生高重复频率和高平均功率的脉冲激光。本文研究了印刷电路板预电离TEA CO2激光器中有、无紫外光体积光电离的两种不同预电离结构形式,主放电均匀性实验表明,在无紫外光体积光电离的情况下,也可以获得放电均匀性很好的大体积主放电。这说明在印刷电路板预电离中起主导作用的是阴极表面的预电离效应。本研究结果对探讨TEA CO2激光器的预电离放电机理具有参考价值。     

XD750-2型放映电源脉冲变压器常见故障及使用方法

井冈山XD750-2型放映机氙灯电源中的脉冲变压器,安装在放映机灯箱内。其作用如下:①为氙灯稳弧,脉冲变压器的绕组串接在氙灯阴极与主电源负极端之间,而且安装在氙灯的下方,当氙灯正常点亮时,氙灯电流通过其绕组的阻抗可对氙灯的电弧起稳弧作用。所以,脉冲变压器又称稳弧线圈;②为氙灯触发时提供高频高压。脉冲变压器其中一个绕组与高压涤沦电容串接,组成高频揩振电路,形成电磁振荡,在回路中生成几万伏的高频脉冲电压,加在氙灯阴极和阳极之间,将氙灯内的氙气击穿,形成电离火花放电,引燃氙灯。     

关于脉冲氙灯寿命问题的探讨

一、脉冲的概述 脉冲氙灯早在四十年前国外有人开始研究,这些年来,对氙灯作了很多改进和提高的工作。近十几年激光器的发明及其发展,又推动了脉冲氙灯作深入的研究。它是一种气体放电器件,是管的充有高纯氙气的放电管,是一各把电能转换成幅射能的器件。它在启点进加以高压触发脉冲,使灯管内气体予电离击穿,与时同时,储存在电容器上的能量通过予最离火花     

泵浦准连续波激光器用的闪光灯触发器

在泵浦脉冲和脉冲之间的预燃电流期间内,有源触发电路使电流保持恒定。     

脉冲预电离非自持纵向放电CO2激光器

研究了脉冲预电离的非自持纵向放电CO2激光器。采用了一种新颖的螺旋形横向脉冲预电离结构。激光器的主放电和输出功率由外加的预电离脉冲控制,可省去限流电阻。最大电光转换效率达19%。     

零电压开关预燃电源的研究

本文提出了在脉冲氙灯预燃电路中将着火电压与预燃电流由不同电路来提供的设计思想 ,并采用了零电压开关技术。对逆变器的工作过程进行了数学分析 ,对功率开关管实现零电压开通的条件进行了讨论。实验证明该预燃电源在负载断路和短路情况下都能正常工作 ,功率开关管的开关损耗非常小 ,开关频率可达 10 0 k Hz,减小了电源体积 ,提高了电源效率 ,适用于各种尺寸的脉冲氙灯。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.