集成光学光纤陀螺芯片

本文首次报道了国内研制的集成光学光纤陀螺芯片,详细描述了其设计考虑与制作。单 Y 型多功能钛扩散铌酸锂芯片包含消光比大于35dB 的薄膜波导偏振器、分束比为49.5/50.5的3dB 分束器/合束器、半波电压小于5伏的相位调制器,光纤—器件—光纤插入损耗为5.4dB。     

铌酸锂光波导器件保偏尾纤对轴工艺研究

基于采用退火质子交换工艺制备的铌酸锂光波导器件的保偏尾纤具有高偏振消光比这一特性,提出了一种通过偏振消光比测试仪测定器件保偏尾纤的偏振轴并实现与保偏连接头定位键高精度对准的方法.工艺实验证明,采用该方法制作的保偏尾纤连接头偏振轴向对准精度优于0.8°,显著优于显微成像定轴方法制作的保偏尾纤接头.     

高性能硅和铌酸锂异质集成薄膜电光调制器 （特邀）

硅基光子集成平台因其高集成度、CMOS工艺兼容性等特点在光通信领域受到了广泛的关注,而电光调制器作为光通信系统中最为重要的器件之一,承担着将电信号加载至光信号上的关键作用,为打破硅基调制器的性能限制,可利用硅和铌酸锂的大面积键合技术以及铌酸锂低损耗波导刻蚀技术实现高性能硅和铌酸锂异质集成薄膜电光调制器,目前该类调制器的性能可达半波电压3 V,3 dB电光带宽超过70 GHz,插入损耗小于1.8 dB, 消光比大于40 dB。文中对比了硅和铌酸锂异质集成调制器的研究现状并介绍了该异质集成薄膜调制器的结构设计与工艺实现方法。     

保偏光纤环与Y波导芯片直接耦合技术研究

光纤陀螺光路结构中,Y波导器件与保偏光纤环通过尾纤熔接的方式连接形成闭合回路来敏感系统相对惯性空间的转动信息,而熔接点引入的偏振交叉耦合以及背向反射是制约光纤陀螺测量精度进一步提高的主要因素.为此,提出了一种实现保偏光纤环与Y波导芯片直接耦合的方法,并制作了两者直接耦合的敏感环光路.经实验测试,光路中Y波导器件的插入损耗典型值为2.7 dB,分光比优于48/52～52/48,偏振串音优于-30 dB,性能指标与常规的Y波导器件相当.该光路模块理论上有利于减小光纤陀螺系统噪声和提高测量精度.     

低损耗单模尾纤2×2光开关

本文报导了一种新研制的低损耗带单模尾纤的2×2光开关,工作波长1.3μm。讨论了器件工作原理,详细描述了其制作工艺和测试方法。器件插入损耗小于5dB,开关电压小于8V,消光比大于15dB。     

H:LiNbO3光波导

铌酸锂晶体具有良好的光声和电光性质，因而基于铌酸锂的集成光学器件已引起人们的广泛关注。质子交换法是一种制备铌酸锂光波导的重要方法。质子交换铌酸锂光波导具有制作工艺简单，折射率增量大，抗光折变能力强及可实现单偏振激励等特点。本文对质子交换铌酸锂光波导的制作工艺、波导特性及其应用进行了讨论，并指出目前应加强质子交换光波导、质子交换生长动力学和交换工艺的研究。     

全封装的薄膜铌酸锂电光调制器（特邀）

高速电光调制器是宽带光通信网络和微波光子系统中的关键元器件之一。相对于体材料铌酸锂而言,薄膜铌酸锂材料由于其较强的光场限制能力,在构建小尺寸、宽带、低半波电压的高性能电光调制芯片上有独特的优势。文章基于薄膜铌酸锂材料研制了一种3 dB带宽不低于50 GHz的电光调制芯片,并采用光纤与波导水平端面耦合的光学封装方案和基于1.85 mm同轴接头的射频封装方案,实现了全封装的薄膜铌酸锂电光调制器。测量结果表明,封装后器件的光学插入损耗小于等于5 dB,3 dB带宽大于等于40 GHz,射频半波电压小于等于3 V@1 GHz。     

1064nm低电压薄膜铌酸锂电光调制器

低半波电压电光调制器是实现大规模光电集成的关键。文章提出了一种半波电压低于1.5 V的薄膜铌酸锂马赫-曾德尔(Mach-Zehnder, MZ)电光调制器，选用绝缘体上单晶薄膜铌酸锂材料作为设计基础，分析了直波导、多模干涉耦合器、弯曲波导和调制臂等结构对电光调制器的影响。结果表明，当调制臂长为3 mm时，该薄膜铌酸锂电光调制器具有1.05 V的低半波电压、0.319 dB的低损耗和27 dB的高消光比。同时，该调制器半波电压长度积为0.315 V·cm,调制效率高，具有与CMOS技术兼容的半波电压，有利于大规模光电集成。     

采用双Y型LiNbO_3集成光路的闭环光纤陀螺研究

集成化已成为研制中、高精度大动态范围光纤陀螺的一个必然途径。文中报道了一种采用光纤滤波/双Y型集成光路和全数字处理的闭环光纤陀螺,其中光纤滤波/双Y型多功能集成光路是采用退火质子交换法(APE)在铌酸锂衬底上制作而成的,它包含了光纤陀螺所需的除光纤线圈以外的无源光学器件的全部功能:两个分光/合光器(耦合器)、两个宽带相位调制器(推挽工作)和一个高消光比的偏振器,测试结果表明,陀螺零偏稳定性优于1°/h。该陀螺结构紧凑、动态范围大、精度适中、成本低,特别适合于战术级的应用     

铌酸锂薄膜高速电光开关的设计与制备

基于硅基铌酸锂薄膜（Lithium Niobate on insulator,LNOI）材料平台，设计并制备了高速电光开关芯片，并实现了芯片的光纤耦合、管壳封装和性能测试。测试结果表明，该高速电光开关器件的开关速度达到13.4 ns，消光比达到31.8 dB。研究工作对未来研制光学延时芯片和波束形成网络芯片具有重要的支撑意义。     

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.     

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.     

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.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.