Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

选择性埋氧层上硅器件的单粒子瞬态响应的温度相关性

本文建立了90 nm工艺下的绝缘体上硅浮体器件和选择性埋氧层上硅器件模型,通过器件电路混合仿真探究了工作温度对上述两种结构的多级反相器链单粒子瞬态脉冲宽度以及器件内部电荷收集过程的影响.研究表明, N型选择性埋氧层上硅器件相较于浮体器件具有更好的抗单粒子能力,但P型选择性埋氧层上硅器件的抗单粒子能力在高线性能量转移值下与浮体器件基本相同.同时电荷收集的温度相关性分析表明,N型选择性埋氧层上硅器件只存在漂移扩散过程,当温度升高时其电荷收集量变化很小,而N型浮体器件存在双极放大过程,电荷收集量随着温度的升高而显著增加;另外, P型选择性埋氧层上硅器件和浮体器件均存在双极放大过程,当温度升高时P型选择性埋氧层上硅器件衬底中的双极放大过程越来越严重,由于局部埋氧层的存在,反而抑制了其源极的双极放大过程,导致它的电荷收集量要明显少于P型浮体器件.因此选择性埋氧层上硅器件比浮体器件更好地抑制了温度对单粒子瞬态脉冲的影响.     

Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

紧缩型含氟聚酰亚胺多模干涉波分复用器的FD-BPM分析

为了减小波分复用器的器件长度,在聚酰亚胺材料的基础上,设计了一种赝态结构的2×2多模干涉波分复用器,并分别用精确导模分析法对其进行模拟分析和优化设计。结果表明,赝态结构波分复用器可以有效地对980nm和1550nm光进行解复,并且器件尺寸只有传统设计的1/5。器件在器件长度和波长变动中显示出良好的容差性,并且能够和掺铒放大器与激光器实现集成。其中,赝态结构MMI聚酰亚胺波分复用器的干涉区宽度和长度以及输入口宽度和距离对其性能均有影响。     

Extraction of Waveguided Llight by Anisotropic Scattering Polarizer in Organic Electroluminescent Devices

We demonstrated that the anisotropic scattering polarizer (ASP) laminated to a glass substrate surface increased the optical efficiency of an organic electroluminescent (EL) device for liquid crystal display (LCD) backlight applications. ASP was prepared by drawing the liquid crystal polymer (LCP) dispersed poly(carbonate) film and extracted the emitting light trapped in the substrate of an organic EL device involved in polarization selectivity. Light extraction ability and polarization selectivity were changed by thickness of the electron transporting layer (ETL) of the organic EL device. Optical efficiency of a 60 nm thick ETL device through absorbing polarizer was not much improved by the lamination of ASP, whereas low efficiency of a 120 nm thick ETL device was greatly improved by this lamination due to extraction of the waveguided light as a substantially polarized emission. Although the degree of increase for the 120 nm thick ETL device was very large, the final optical efficiency was less than or only comparable to that of the thinner device. In 90 nm thick ETL device, however, the lamination of ASP increased the optical efficiency by a factor of 1.2–1.3 against a 60 nm thick ETL device. © 2004 The Optical Society of Japan     

散斑面内形变场检测系统设计

数字散斑测量是一种非接触、全场测量的高精度光测方法。该系统由散斑生成装置、数据采集装置和数据处理装置三部分组成。散斑生成装置将扩散的激光束投射到待测物体上,用接收屏接收物体散射生成的散斑图像。数据采集装置主要由CCD和数字采集卡组成,CCD拍摄散斑图像,并将其传输给数字采集卡,经采集卡转换成数字图像,以矩阵形式输入到数据处理装置。数据处理装置根据光学相关识别技术设计的检测程序对采集到的数字图像进行相关运算,通过对相关峰的准确定位来获取物体的形变信息。     

Transparent device with homogeneous material parameters

A transparent device is an electromagnetic structure that is explicitly designed to be transparent to incoming electromagnetic waves. Based on coordinate transformation theory, a novel diamond-shaped transparent device is proposed and designed. It can protect electronic equipments inside without affecting their performance. Compared with a traditional transparent device, the material parameters of the novel transparent device feature homogeneity and non-singularity, which can easily be realized in actual applications. Full-wave simulations are made to validate the performance of the transparent device.     

Comparison of electrochromic characteristics of electrochromic device upon various sintering methods of sol-gel based WO3 electrode

Tungsten oxide is an electrochromic material, from which thin films are conventionally fabricated via heat treatment. Here, we develop a flash light sintering method to reduce sintering time; sintering delivers instantaneous photon energy created via the photothermal effect. The electrochromic efficiency of device with a flash light-sintered electrode was 88.50 cm²/C, about 1.46-fold greater than that of the device with a heat-sintered electrode. The diffusion coefficients of the former device were 1.35- and 1.46-fold greater than those of the latter device during bleaching and coloring, respectively. Therefore, a new way of sintering electrode was studied to show that the device with flash light–sintered electrode demonstrate better electrochromic performance than the device with heat-sintered one by enabling amorphous phase formation.     

Wave-plate polarizing beam splitter based on a form-birefringent multilayer grating

We have fabricated a novel device that acts as a quarter-wave plate at normal incidence and as a polarizing beam splitter at an angle of incidence of ~40 deg . The device is made from a multilayer (SiO(2) /Si(3)N(4)) surface-relief zeroth-order one-dimensional grating with a period of 0.3 mum . The device is designed for an operating wavelength of 632.8 nm. We designed the device by using rigorous coupled-wave analysis and fabricated it by direct-write electron-beam lithography and reactive ion etching. Measurements confirmed the performance of the device as a wave plate and as a polarizing beam splitter.     

Effect of optical radiation in a photo-DOVATT

Avalanche photodetectors are very important solid-state detectors currently used in long-distance and wide-band optical communication systems, due to their faster speed of response compared to other solid-state photodiodes. Furthermore, it has been found that by using heterostructures one can improve both multiplication gain and quantum efficiency of such a device. DOVATT is a heterojunction impatt device in which there is one avalanche zone followed by two drift zones at different scattering limited velocities. The device is very useful for generation of high power in the X-band.The present paper examines the effect of optical radiation on such a device. Studies have been made on the frequency-response characteristics of the device. The results show that the device has the potentiality of becoming a powerful photodetector in optical communication systems.     

Novel multifunctional optical device with only axial material parameter spatially variant

Based on the concept of complementary media and theory of coordinate transformation,a novel kind of optical device,exhibiting the multiple performances of a complementary cloak and a transparent device,is proposed.Only the axial material parameter of the proposed device is spatially variant,and the transverse material parameters are constant.The multiple functions of the proposed device are validated by full wave simulations.In addition,the effects of loss and parameter perturbations on the performances of the device are also investigated.These results can be used in field of antenna protection and other electromagnetic field engineering.     

Electrical properties of an organic memristive system

We present a study on an organic resistive switching device based on the heterojunction of a thin conducting polyaniline (PANI) layer and a ions containing gel (or solution). We have studied the device, characterized by a non-linear and rectifying response to the applied voltage, as a function of some chemical and geometrical parameters such as solution pH, ions concentration and junction contact area, finding out their influence on the device electrical parameters such as the saturation current, the activation voltage, and the response time. The study leads us to develop a physical model of the device and control its response through the fabrication process predicting also interesting properties obtainable with a device miniaturization.     

一种采用Li3N掺杂电子注入层的底发射倒置结构OLED的制备

采用Li3N掺杂电子注入层Alq3∶Li3N,制作了一种结构为ITO/Alq3 Alq3∶Li3N/Alq3/NPB/MoO3/Al的倒置底发射有机发光器件.其中ITO玻璃作为透明阴极,金属Al作为顶部阳极,在ITO阴极与电子传输层之间加入Li3N n型掺杂层,改善了该器件的电子注入和传输能力|在Al阳极与空穴传输层之间加入MoO3缓冲层,降低了Al阳极与NPB之间较大的空穴注入势垒,改善了空穴注入能力.实验表明:此结构的倒置底发射有机发光器件性能可达到传统结构的常用有机发光器件如ITO/NPB/Alq3/LiF/Al的性能,完全可以满足非晶硅薄膜晶体管有源有机发光器件中驱动电路的匹配及性能要求.     

MoO3为缓冲层的高效非掺杂蓝色有机发光二极管

以典型蓝色发光材料-联苯乙烯衍生物(4,4’-bis(2,2’-diphenylvinyl) -1,1’-biphenyl,DPVBi)为发光层,采用MoO3为阳极缓冲层制备了结构简单的非掺杂型蓝色有机电致发光器件.在电流密度为20 mA/cm2、MoO3缓冲层厚度为0.5 nm对器件效率约为无缓冲层器件效率的18倍,...     

一款小角X射线散射原位测量专用简易样品加热装置

原位加热实验是同步辐射小角X射线散射领域的新热点。本文针对同步辐射小角X射线散射中需要加热并原位实时检测的实验而设计的一款样品简易原位加热专用装置,该装置主要由温控器、样品池、固定架组成,它具有结构简单、操作容易的特点。本文介绍该装置的基本结构、特点并采用该装置进行原位加热干燥褐煤实验,通过分析实验结果验证装置的可行性。     

具有纵向漏极场板的低导通电阻绝缘体上硅横向双扩散金属氧化物半导体器件新结构

为降低绝缘体上硅(SOI)横向双扩散金属氧化物半导体(LDMOS)器件的导通电阻,同时提高器件击穿电压,提出了一种具有纵向漏极场板的低导通电阻槽栅槽漏SOI-LDMOS器件新结构.该结构特征为采用了槽栅槽漏结构,在纵向上扩展了电流传导区域,在横向上缩短了电流传导路径,降低了器件导通电阻;漏端采用了纵向漏极场板,该场板对漏端下方的电场进行了调制,从而减弱了漏极末端的高电场,提高了器件的击穿电压.利用二维数值仿真软件MEDICI对新结构与具有相同器件尺寸的传统SOI结构、槽栅SOI结构、槽栅槽漏SOI结构进行了比较.结果表明:在保证各自最高优值的条件下,与这三种结构相比,新结构的比导通电阻分别降低了53%,23%和提高了87%,击穿电压则分别提高了4%、降低了9%、提高了45%.比较四种结构的优值,具有纵向漏极场板的槽栅槽漏SOI结构优值最高,这表明在四种结构中新结构保持了较低导通电阻,同时又具有较高的击穿电压.     

Numerical and analytical investigations for the SOI LDMOS with alternated high-k dielectric and step doped silicon pillars

This paper presents a new silicon-on-insulator(SOI) lateral-double-diffused metal-oxide-semiconductor transistor(LDMOST) device with alternated high-k dielectric and step doped silicon pillars(HKSD device). Due to the modulation of step doping technology and high-k dielectric on the electric field and doped profile of each zone, the HKSD device shows a greater performance. The analytical models of the potential, electric field, optimal breakdown voltage, and optimal doped profile are derived. The analytical results and the simulated results are basically consistent, which confirms the proposed model suitable for the HKSD device. The potential and electric field modulation mechanism are investigated based on the simulation and analytical models. Furthermore, the influence of the parameters on the breakdown voltage(BV) and specific on-resistance(R_on,sp) are obtained. The results indicate that the HKSD device has a higher BV and lower R_on,sp compared to the SD device and HK device.     

Demonstration of nanophotonic NOT gate using near-field optically coupled quantum dots

We propose and demonstrate the operation of a nanometric optical NOT gate using CuCl quantum dots coupled via an optical near-field interaction. The device was smaller than 20 nm and its repeated operation was verified. The operating energy of this device was much lower than that of a conventional photonic device. We also introduce all-optical NAND and NOR gates using coupled quantum dots. Toward an actual nanophotonic device, we discuss the possibility of coupled InAlAs quantum dots. A double layer of InAlAs quantum dots for nanophotonic device operation was prepared using molecular beam epitaxial growth. We obtained a near-field spectroscopy signal, indicating that the InAlAs quantum dots coupled with the optical near field acted as a NOT gate. The experimental results show that the sample has great potential as an actual nanophotonic device. PACS 78.67.Hc; 07.79.Fc; 42.79.Ta     

基于AlN声表面波滤波传感器器件的有限元仿真

声表面波器件是一种利用压电材料的压电效应与逆压电效应工作电子器件, 文章首先详细描述了声表面波器件的设计与仿真过程,运用有限元分析的方法分别计算了利用声表面波的 SAW 器件与利用体波的 BAW 器件的性能与各项参数,对相关的器件进行了计算分析,分别用上述方法研究了基于 AlN 薄膜的声表面波器件和悬臂梁结构的体波器件,推导得出了器件的电学导纳与频率之间的关系, 通过分析器件的导纳-频率曲线,推导出器件内部声波的模式以及合适的工作频率,最终得出在 IDT 周期为 8 微米的情况下,SAW 器件的理想工作频率是 0.7-1.95GHz,BAW 器件的理想工作频率在 0.6-3.2GHz 的结果。     

晶界对金刚石紫外探测器时间响应性能的影响

持续光电导现象是影响多晶金刚石紫外探测器时间响应性能的一个不利因素,它的存在会大大延长探测器的响应时间.本文在微米晶金刚石薄膜上制备了叉指电极间距分别为20μm和30μm的紫外探测器(分别称为器件A和器件B),讨论了晶界对多晶金刚石紫外探测器时间响应性能的影响.结果表明,器件A和器件B均表现出持续光电导和光电导增益现象,并且器件B比器件A更显著.分析得出,晶界缺陷可能在金刚石带隙中引入一个浅能级并起少数载流子陷阱中心的作用,导致了探测器的持续光电导现象和高增益.相比器件A,器件B电极间具有更多的晶界数量,因此器件B表现出更为显著的持续光电导和更高的光电导增益.