改进型SOA-MZI全光异或门的加解密仿真研究

全光加密技术是解决目前光纤通信网的加解密速率瓶颈及物理层潜在的安全威胁的有力保证。针对现有全光异或加解密方案工作速率普遍较低的问题,在传统的SOA-MZI型全光异或门的基础上,利用两段色散互补的G.655单模光纤,并结合一个相位偏移器设计了一种改进型SOA-MZI全光异或方案,以该改进方案作为全光安全处理器在OptiSystem7.0仿真平台上搭建新的全光异或加解密方案,对输入信号比特速率分别为10Gb/s和40Gb/s的加解密方案进行了仿真实验验证。结果表明:基于改进型SOA-MIZ全光异或门的加解密方案可将全光异或加解密速率提高到40Gb/s,并且解密恢复出的明文数据的消光比约可以达到20dB,最大Q值约为25.7,加解密过程不会对通信系统引入额外误码。     

量子遗传进化算法的收敛性研究

量子遗传算法建立在量子的态矢量表达基础上,染色体的编码用量子比特的几率幅表示,使得一条染色体表达多个态的叠加,再利用量子门实现染色体更新操作,从而达到目标的优化求解.它具有种群规模小而不影响算法性能,收敛速度快和全局优化能力强等特点.但是遗传算法的随机性不好把握,收敛方向不好控制,针对遗传算法的种种问题,通过多种方法来对收敛性进行研究.     

基于重叠栅工艺的硅量子点阵列的制备与调控

利用半导体量子点阵列结构实现近邻耦合是规模化扩展自旋量子比特的主要方案之一.随着量子点数目的增加,量子点阵列器件的制作工艺及参数调控均愈加复杂.本文介绍了一种重叠栅工艺结构,利用多层相互重叠且具有不同功能的栅极定义量子点,制作出结构紧凑、调控性好的量子点阵列器件,解决了工艺扩展的难题.此外,本文发展了一套高效可靠的调控方法,按顺序逐个添加量子点并建立虚拟电极,实现了对量子点参数的独立控制,并且能够高效且独立地调控各量子点中的电子数目,克服了大规模量子点阵列中电压参数配置的困难.这些方法为未来实现大规模自旋比特阵列提供了一种标准化的方案.     

基于FPGA的自适应旁瓣对消原理及其实现

自适应旁瓣对消(ASLC)是雷达抗有源干扰的有效方法。它采用空间滤波技术，通过辅助接收通道在干扰方向形成波束图的零点，实现对干扰信号的抑制。本文介绍了自适应旁瓣对消的原理，然后给出了基于FPGA的ASLC实现方案，最后通过仿真和试验结果，分析了自适应旁瓣对消的性能。     

Design and analysis of low power high-speed 1-bit full adder cells for VLSI applications

This paper presents a low power and high speed two hybrid 1-bit full adder cells employing both pass transistor and transmission gate logics. These designs aim to minimise power dissipation and reduce transistor count while at the same time reducing the propagation delay. The proposed full adder circuits utilise 16 and 14 transistors to achieve a compact circuit design. For 1.2 V supply voltage at 0.18-μm CMOS technology, the power consumption is 4.266 μW was found to be extremely low with lower propagation delay 214.65 ps and power-delay product (PDP) of 0.9156 fJ by the deliberate use of CMOS inverters and strong transmission gates. The results of the simulation illustrate the superiority of the newly designed 1-bit adder circuits against the reported conservative adder structures in terms of power, delay, power delay product (PDP) and a transistor count. The implementation of 8-bit ripple carry adder in view of proposed full adders are finally verified and was observed to be working efficiently with only 1.411 ns delay. The performance of the proposed circuits was examined using Mentor Graphics Schematic Composer at 1.2 V single ended supply voltage and the model parameters of a TSMC 0.18-μm CMOS.     

Al2O3高k栅介质的可靠性

利用反应溅射方法制备了等效氧化层厚度为3．45nm的Al2O3栅介质MOS电容，研究了Al2O3作为栅介质的瞬时击穿和恒压应力下的时变击穿等可靠性特征．击穿实验显示，样品的Al2O3栅介质的等效击穿场强大小为12.8MV／cm.在时变击穿的实验中，Al2O3栅介质表现出类似于SiO2的软击穿现象．不同栅压应力作用的测试结果表明，介质中注入电荷的积累效应是引起软击穿的主要因素，其对应的介质击穿电荷QBD约为30～60C／cm^2．     

SOI CMOS器件研究

利用0.35μm工艺条件实现了性能优良的小尺寸全耗尽的器件硅绝缘体技术(SOI)互补金属氧化物半导体(FD SOI CMOS)器件,器件制作采用双多晶硅栅工艺、低掺杂浓度源/漏(LDD)结构以及突起的源漏区。这种结构的器件防止漏的击穿,减小短沟道效应(SCE)和漏感应势垒降低效应(DIBL);突起的源漏区增加了源漏区的厚度并减小源漏区的串联电阻,增强了器件的电流驱动能力。设计了101级环形振荡器电路,并对该电路进行测试与分析。根据在3V工作电压下环形振荡器电路的振荡波形图,计算出其单级门延迟时间为45ps,远小于体硅CMOS的单级门延迟时间。     

Characteristics of GdGaO grown by MBE

Ga₂O₃/GdGaO dielectric stacks have been grown on GaAs for MOSFETs. This paper highlights variations in the characteristics of GdGaO as the Gd flux, Ga₂O flux and substrate temperature are changed. The growth rate, composition, crystallinity are discussed and the sheet resistance of final MOSFET structures are presented. The Gd compositional variation with depth is examined using Rutherford back scattering (RBS) and electron energy loss spectroscopy (EELS).     

热囚禁离子系统中的两量子比特条件相位门的简单方案

提出了一个实现两离子量子逻辑门的简单方案。本方案使用了两个囚禁于线性阱的三能级离子。本方案不使用振动模作为数据总线,仅需要激光与离子的单个相互作用,因而相互作用时间变短,这点从退相干的角度看是很重要的,而且本方案对振动模的加热不敏感。     

Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

Full field laser Doppler imaging (LDI) and single exposure laser speckle contrast imaging (LSCI) are directly compared using a novel instrument which can concurrently image blood flow using both LDI and LSCI signal processing. Incorporating a commercial CMOS camera chip and a field programmable gate array (FPGA) the flow images of LDI and the contrast maps of LSCI are simultaneously processed by utilizing the same detected optical signals. The comparison was carried out by imaging a rotating diffuser. LDI has a linear response to the velocity. In contrast, LSCI is exposure time dependent and does not provide a linear response in the presence of static speckle. It is also demonstrated that the relationship between LDI and LSCI can be related through a power law which depends on the exposure time of LSCI.