单模光纤中高斯脉冲无啁啾稳定传输

在分析单模光纤群速度色朦胧（GVD）效应和自相位调制（SPM）效应相互作用的基础上，导出GVD和SPM共同作用引起的啁啾表达式，全面分析了色散长度LD、非线性长度LNL与啁啾变化的关系。结果表明：随着LD/LNL的不同，啁啾特性有着显著变化，当N=LD/LNL=1，即实现了单模光纤中群速度色散效应与非线性效应相互作用所致啁啾的最佳匹配，通过控制脉冲输入功率，可望实现高斯光脉冲无啁啾的稳定传输。     

单模光纤中高斯脉冲无啁啾稳定传输

在分析单模光纤群速度色散(GVD)效应和自相位调制(SPM)效应相互作用的基础上,导出GVD和SPM共同作用引起的啁啾表达式,全面分析了色散长度L_D、非线性长度L_(NL)与啁啾变化的关系。结果表明:随着L_D/L_(NL)的不同,啁啾特性有着显著变化,当N=L_D/L_(NL)=1,即实现了单模光纤中群速度色散效应与非线性效应相互作用所致啁啾的最佳匹配,通过控制脉冲输入功率,可望实现高斯光脉冲无啁啾的稳定传输。     

蓝移啁啾和红移啁啾的相互作用关系

通过研究群速度色散（GVD）和自相位调制（SPM）的相互作用，推导出了蓝移啁啾和红移啁啾共同作用所致啁啾的解析表达式。研究结果表明，当色散长度LD和非线性长度LNL确定后啁啾随Z和T的变化特性完全确定，随着LD／LNL的不同，啁啾特性发生了明显变化，通过控制输入功率可实现无啁啾传输，保持脉冲的稳定性。     

损耗和啁啾对皮秒脉冲孤子效应压缩的影响

在计及光纤损耗的前提下,近似求解非线性薛定谔方程,分析了单模光纤的负群速度色散区群速度色散(GVD)和自相位调制(SPM)对啁啾脉冲的作用,定量计算光纤损耗和初始正啁啾对皮秒脉冲孤子效应压缩的影响。结果表明,初始正啁啾改善了损耗对压缩参量的不良影响,遏制了最佳光纤长度的增加。若选取适当的光纤长度和初始峰值功率,可以实现正啁啾脉冲在单模光纤中的有效压缩。     

超高斯啁啾光脉冲在单模光纤中传输的演化行为

本文从激光脉冲在单模光纤中传输所满足的非线性薛定谔方程出发,通过分步傅里叶变换方法,数值研究了超高斯啁啾光脉冲在单模光纤中脉冲形状的演化.研究表明,超高斯脉冲在单模光纤中传输将经历一个从近平顶、多峰、最后到单峰的演变过程,且高阶色散将引起脉冲形状发生畸变;在GVD和SPM效应的共同作用下,无啁啾的超高斯脉冲在特定条件下将出现孤子演变,具有正啁啾的超高斯脉冲在传输的初始阶段,脉冲形状的变化非常剧烈,而由于负初始啁啾减弱了非线性与色散效应引起的频率啁啾,所以其脉冲波形的变化平缓一些.研究表明,SPM产生的啁啾对入射脉冲的初始啁啾有一定的补偿作用.     

光参量效应中低阶色散对超短高斯脉冲展宽的影响

以宽度为50 fs的超短脉冲和负单轴晶体CsLiB6O10(CLBO)为例,对非线性光学晶体中低阶群速度色散(GVD)导致的超短高斯脉冲和超高斯脉冲的脉冲展宽进行了理论分析.在光参量相互作用过程中,对初始无啁啾和有啁啾调制的超短高斯脉冲的脉冲展宽机制和因素进行了数值计算,得出群速度色散导致超短脉冲的寻常光比非寻常光脉冲展宽更严重;波长越短,脉冲展宽越大;当晶体长度等于色散长度时,脉冲宽度增加为初始时的2倍,色散长度越短,超短脉冲展宽越明显.     

单模光纤正常色散区啁啾演变研究

对单模光纤正常色散区，群速度色散所致啁啾、自相位调制所致啁啾以及两者共同作用所致啁啾的演变过程进行了研究。利用傅里叶变换法获得群速度色散所致啁啾、自相位调制所致啁啾的解析解，采用数值法得到了群速度色散效应与自相位调制效应共同起作用时，啁啾演变过程。由啁啾演变结果可得，在正常色散区可形成暗孤子，也可实现对皮秒脉冲压缩。     

单模光纤反常色散区零色散波长附近的啁啾演变

当单模光纤的反常色散区二阶，三阶色散同时存在时，首次推出了群速度色散致啁啾的解析表达式，并讨论了啁啾演变过程。利用数值方法，模拟了零色散波长附近群速度色散效应与自相位调制效应共同作用时啁啾的演变。结果表明，三阶色散会导致脉冲铅的畸变。     

皮秒正啁啾脉冲的孤子效应压缩

在近似求解非线性薛定谔方程、分析单模光纤负群速度色散区群速度色散和自相位调制效应所致频率啁啾对入纤正啁啾脉冲的调制压缩机理的基础上，定量计算了在光纤负色散区损耗对初始正啁啾皮秒脉冲孤子效应压缩的影响．结果表明：初始正啁啾改善了损耗对压缩参量的不良影响，遏制了最佳光纤长度的增加，增强了压缩效果，提高了压缩质量．选取适当的光纤长度和初始峰值功率，可望实现光学脉冲在单模光纤中的有效压缩．     

光纤中超连续谱产生机理研究

从非线性薛定谔方程出发,分析了自相位调制(SPM)和群速度色散(GVD)效应对超连续(SC)谱的贡献。利用主动锁模光纤激光器作为泵浦光源。对色散位移光纤(DSF)中的SC谱展宽进行了实验研究。理论和实验结果表明,光纤中,SC谱的产生主要是SPM和GVD共同作用的结果：对于皮秒泵浦脉冲和常规光纤,仅考虑SPM和GVD效应,就可以较精确地描述光纤中SC谱的产生过程。     

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.