无抖动机械式光开关结构设计

纳米金属光栅的透射光谱对临近材料折射率变化非常敏感,可以通过改变介质折射率实现可调的彩色滤光,将双层纳米金属光栅应用于显示装置上具有工艺制备简单、色度和对比度高等特点。采用纳米金属光栅结构,通过严格耦合波理论模拟和表面等离子体共振原理设计了一种新型的透射式电润湿显示器件。在650nm周期、空气环境下,通过数值优化在690nm波长处得到了50%的单色透射,而在水溶液的环境下,由于共振移动到红外,可以实现黑态显示,从而验证了灰度的可调。该研究将为轻薄、节能和高分辨率的新型电浸润显示器件设计提供全新思路。 更多还原     

用纳米印刷技术制备微机械和微流体金属光栅器件

纳米印刷技术是一种制备大面积亚波长光栅的新技术。基于此光栅的滤光器具有光谱的特性。利用波长耦合分析法对光栅进行理论模拟,此模拟允许反射率取最大和最小值：利用微电子机械系统（MEMS）制备微流体和微机械光栅,这些光栅是制备可调滤光器和其他可选择波长器件的基本元件。这些可调器件通过改变光栅表面的折射率实现波长的选择。如果在光栅表面附着一层水膜。光栅共振波长可改变33％;如果在光栅表面覆盖石英。则共振波长从558nm改变到879nm,波长改变率高达58％。此外,大约有3种因素可改变单一波长的折射率。这些光栅器件在可调滤光器或光调节器方面有着重要的应用价值。     

亚波长金属周期结构中表面等离子体相关机理和应用

研究了一种新型的有表面凹槽的亚波长金属光栅结构,通过改变表面凹槽填充物的折射率,可调控该结构的远场透射效率,在光学探测、生物传感等方面具有应用前景;结合金属波导理论,提出一种基于亚波长金属光栅波导结构的新型超分辨光刻方案,入射光波长为436 nm时,最高刻写分辨率可达34 nm.     

透射式金属光栅耦合SPR传感器

用磁控溅射技术在双面抛光的蓝宝石衬底上沉积了20 nm Ti和100 nm Au的金属薄膜,通过标准光刻工艺制备出1.6和2.0μm两种周期结构的一维光栅表面等离子体共振(SPR)传感器。用时域有限差分算法(FDTD)模拟仿真并结合实验测试的透射光谱,研究分析了不同周期结构的金属薄膜光栅型SPR传感器的特性。基于金属光栅耦合,利用表面等离子体激元(SPP)的局域特性和光栅的选频特性,实现了SPR传感器的信号增强和滤波功能。研究结果表明,利用金属薄膜光栅表面介质的变化引起的光栅透射光谱中激发表面等离子体共振峰的位置变化,可以获得被测物体的物理、生物和化学等相关特征信息。     

基于非对称折变型超长周期光纤光栅的湿度传感器

利用高频CO2激光在普通通信单模光纤上制作了非对称折变型超长周期光纤光栅(ULPFG),由于这种光栅只有较高的外界折射率响应灵敏度,可基于此设计制作高灵敏度湿度传感器.通过在ULPFG的表层涂覆一层具有较强吸水性的新型纳米复合水凝胶,水凝胶通过吸收空气中的水蒸气而使自身的折射率发生变化,从而导致ULPFG透射谱的谐振峰发生漂移,通过检测ULPFG谐振峰的漂移量就实现了对环境湿度参量的传感.实验结果表明,在38%～96%的相对湿度变化范围内,光栅谐振峰的最人漂移量可达约30 nm,比先前一些报道的湿度传感器的灵敏度高出近3倍.     

环境折射率对长周期光纤光栅谐振波长的影响

长周期光纤光栅是近几年出现的新型光纤器件,表现为前向传播的纤芯导模与同向传播的各阶次包层模在特定波长时的模式耦合,因此它在温度、应变、折射率传感方面比普通的光纤光栅有更大的优越性.运用耦合模理论,首先讨论了长周期光纤光栅的谐振波长,并模拟了其透射谱.其次在理论上详细分析了长周期光纤光栅对环境折射率的敏感特性,讨论了环境折射率敏感度因子与包层模次数的关系,并比较了不同环境折射率下的灵敏度.最后模拟了在环境折射率小于光栅包层折射率的情况下,谐振波长随环境折射率变化的规律.     

倒梯形双层金属光栅式偏振分束器

为获得高衍射效率、高消光比、宽带宽及大角度容差的光栅结构，提出了一种在近红外波长区域工作的倒梯形双层金属光栅结构的偏振分束器。该结构引入了一层高折射率介质层，并且将光栅区的光刻胶斜切成倒梯形结构，新的设计增大了光栅的透射效率和消光比。使用严格耦合波分析方法，模拟和优化了偏振分束器的结构参数。结果表明，横磁波及横电波在1 290~1 840 nm波长范围内的透射效率和反射效率分别超过97%和95%。透射和反射的最大消光比分别为33 dB和53 dB。在波长为1 550 nm，入射角为-40~40时，光栅的透射和反射消光比都大于22 dB，达到了高性能偏振分束器的要求。相较于双层金属矩形光栅，所提出的倒梯形双层金属结构表现出更高的透射性与反射性，同时具有更好的设计灵活性。     

可调谐双通道光子晶体滤波器的设计

通过对设计出的一维掺杂光子晶体的数值计算和理论分析,得出:双通道透射峰的波长随杂质光学厚度呈线性变化和双通道透射峰的半高宽随光子晶体折射率n2的增加而减小.以此为基础,设计出可调波长范围达140 nm、滤波通道半高宽的可调范围在1～5 nm、滤波通道透射峰值大于0.98的一维光子晶体双通道可调谐滤波器.     

金属膜衬底上亚波长介质光栅结构的特性及传感应用

提出亚波长介质光栅-金属膜-石英玻璃衬底结构,根据等效介质理论该结构可等效为由金属-光栅-包覆层构成的单面金属包覆波导,在入射波长和入射角满足一定条件时,发生导模共振(GMR)从而产生光波全吸收现象。根据严格耦合波分析(RCWA)理论进行数值分析发现,等效波导中的TM1 GMR峰尖锐,并且对光栅包覆层的折射率变化非常敏感,角度灵敏度为127.87°/RIU(RIU为折射率单位),波长灵敏度为409.35 nm/RIU,在很大的折射率范围内线性度良好。与全介质GMR传感器和光栅型表面等离子体共振(SPR)传感器相比,该结构通过GMR实现较高灵敏度的同时,其较窄的共振峰使得检测精度更高。     

在800~1100nm范围内实现基于狄拉克半金属的多波段超材料波导

提出了一种基于Dirac半金属层的具有四个方孔谐振器的超材料波导,其波长范围为800~1100nm。 在共振波长842nm,921nm,1010nm和1061nm处分别获得四个透射峰（70％,61％,72％和63％）。 这些透射峰源自于分布在主腔和腔1、2、3或4中的磁场的干涉增强作用。通过将费米能量从50meV增加到70meV,可以增加四个透射峰并将其转移到更短的波长。 所提出的超材料波导可能在纳米级滤波器,开关或折射率传感器中应用。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks