共查询到20条相似文献,搜索用时 62 毫秒
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偏振模色散对线性系统脉宽的影响 总被引:5,自引:3,他引:2
研究了线性系统中偏振模色散对均方根脉宽的影响。考虑了光源初始啁啾的作用 ,推导出均方根脉宽的解析表达式 ,分析表明 :二阶偏振模色散对脉冲展宽的作用与群速度色散及啁啾有关 ,一阶偏振模色散的作用则与这两者无关。以啁啾高斯脉冲为例 ,推导出一阶偏振模色散补偿前、后均方根脉宽的解析表达式 ,结果表明 ,适当选择群速度色散和初始啁啾参数 ,可以有效地抑制偏振模色散的展宽效应 ;与主态传输法比较 ,啁啾的存在对后向补偿方法的影响更大 相似文献
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文章从描述皮秒光脉冲在色散缓变光纤(FSDD)中所满足的非线性Schroedinger(NLS)方程出发,数值模拟了高阶皮秒光孤子在不同的FSDD中的孤子效应压缩,并讨论了初始啁啾对其的影响,结果表明,利用FSDD和孤子效应压缩来压缩带有初始啁啾的高阶皮秒光孤子,可以得到更高的压缩比和品质因子,压缩后的脉冲的峰值功率明显提高,而且脉冲被压缩到最窄所需的光纤长度也大大缩短,最后讨论了初始脉宽的影响。 相似文献
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高斯脉冲在色散缓变光纤中传输特性的研究 总被引:6,自引:2,他引:4
应用变分法,研究了高斯脉冲在色散缓变光纤中的传输特性,导出了高斯脉冲参数的演化方程组.在此基础上,讨论了色散缓变和初始啁啾对脉冲宽度的影响. 相似文献
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无初始啁啾高斯光脉冲的色散展宽及色散补偿 总被引:9,自引:1,他引:8
对无初始啁啾高斯脉冲在普通单模光纤中的传输特性及线性啁啾光纤光栅的色散补偿特性进行了理论分析和数值模拟。结果表明,光纤的色散导致了传输脉冲的展宽,线性啁啾光纤光栅能够实现对展宽脉冲的良好补偿,啁啾光栅时延曲线的平滑度和线性度都是影响其色散补偿性能的重要因素。本文对啁啾光纤光栅的制作及其在色散补偿中的应用有一定的指导意义。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
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. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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GU Min-fen LIANG Zhong-cheng WANG Ren-zhou DONG Xiang-mei ZHANG Pei-ming CHEN Jia-bi 《光电子快报》2008,4(2):150-152
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. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献