随机层厚分布的半导体超晶格光荧光对温度的依赖关系

本文提出热激活辐射过程和Berthelot-型的非辐射复合过程互相竞争的简单模型解释无序半导体超晶格的光荧光随温度变化行为,预言了当温度升高荧光衰变时间在某一温度附近快速下降;获得了高温时较大无序度的半导体超晶格比较小无序度的半导体超晶格荧光强,在低温时情况相反;且荧光峰随温度变化存在一个最大值。理论结果与实验观察到的无序半导体超晶格荧光行为一致。     

CATV光网络设备原理及应用:第七讲光发射机的核心控制功能电路

(上接第16期) 由于半导体激光器对温度变化很敏感,因而稳定激光器的光输出是一个重要问题.温度的变化和器件的老化给激光器带来的不稳定因素主要表现为:①激光器的阈值电流随温度成指数规律变化,并随器件的老化而增加,从而使输出光功率发生变化.②随着温度升高和器件老化,激光器的电光转换效率降低,从而使输出发生变化,另外随着温度的升高,半导体激光器的发射波长的峰值位置移向长波.     

浸没型热敏电阻

热敏电阻是半导体测辐射热器的一种。是以测量物体受热后电阻变化为基础的热辐射接收器。器件的灵敏薄片或薄膜是由过渡金属氧化物及其混合物制成,在一定的温度范围内,材料的电阻率随它自身温度的变化     

半导体纳米材料光学吸收谱的温度效应

观测了半导体纳米薄膜材料,在室温下的紫外-可见吸收光谱及随测量温度变化至液氦温区的光谱变化,考察光吸收边随温度降低发生蓝移的情况,进而分析温度效应对晶格参数及电子-声子相互作用的影响,造成其能带漂移.     

敏感电阻器的种类与特点

目前,敏感电阻的种类较多,比较常见的有热敏电阻、光敏电阻,压敏电阻、力敏电阻、磁敏电阻,湿敏电阻和气敏电阻,下面就分别简要介绍。一、热敏电阻。热敏电阻是一种电阻值对温度非常敏感的电阻器,这种电阻一般由单晶、多晶等半导体材料制成,其种类较多,如根据阻值的温度系数、可分为阻值随温度升高而减少的负温度系数热敏电阻和阻值随温度升高而增加的正温度系数热敏电阻;如按阻值随温度变化的大小及变化速废;可分     

基于半导体吸收原理的光纤温度传感器研究

利用半导体GaAs材料对光的吸收随温度变化而变化的原理,设计了一种光纤温度传感系统。该系统具有结构简单、体积小、全光纤化、易实现远程测量及使用方便等特点。实验结果表明,测量系统的精度好于±0.5℃。     

半导体微腔中单量子点的真空拉比分裂的温度效应

采用量子光学和极化子正则变换的方法研究了有限温度下半导体微腔中单量子点的激子动力学行为,并解析得到了激子真空拉比分裂随温度变化的函数关系.     

Temperature Dependence of Vacuum Rabi Splitting in a Single Quantum Dot-Semiconductor Microcavity

采用量子光学和极化子正则变换的方法研究了有限温度下半导体微腔中单量子点的激子动力学行为,并解析得到了激子真空拉比分裂随温度变化的函数关系.     

半导体激光器的高精度温控仪

温度对半导体激光器的特性有很大的影响.在要求半导体激光器输出波长稳定的情况下,必须对其温度进行高精度的控制。本文利用高信噪比的运算放大器和普通的负温度系数温度传感器及半导体致冷器做控温元件,研制了一种用于半导体激光器温度控制的高精度温控仪,控制精度可达±0.05℃.     

CATV光发射机原理及应用（4）

由于半导体激光器对温度变化很敏感，因此稳定激光器的光输出是一个重要问题；温度的变化和器件的老化给激光器带来的不稳定因素主要表现为：(1)激光器的阈值电流随温度成指数变化规律，并随器件的老化而增加，从而使输出光功率发生变化。(2)随着温度升高和器件老化，激光器的电光转换效率降低，从而使得输出变化；     

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.     

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.     

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.     

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.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.