Optical quantum transmitter with finesse of 30 at 800-nm central wavelength using microring resonators

A microring resonator (MRR) system incorporating an add/drop system is presented. The finesse of the proposed system can be determined using the full width at half maximum (FWHM) and free spectrum range (FSR) of the generated multiple soliton pulses. The central wavelength of the bright input soliton pulse has been selected as 800 nm, at which a ring system with better sensitivity shows high finesse that is suitable for applications to many optical communication systems such as optical transmitters and sensors. Simulation results show that FSR of 0.3 nm and 1.1 ns and FWHM of 10 pm and 36.6 ps could be obtained. Therefore, a system with finesse of 30 can be obtained; in such a system, the MRR system shows high performance. This system can be used in optical communication networks as a transmitter system for optical soliton pulses with finesse of 30, and theses pulses can be detected via an optical receiver.     

Time-wavelength assignment algorithms: Hardware/performance tradeoffs

In this paper we present time-wavelength assignment algorithms that consider the following system parameters: (1) the system hardware in terms of the transmitters' and receivers' tuning capabilities (slow or fast tuning) and (2) the traffic matrix. The ulgorithms' objective is to maximize the bandwidth efficiency, i.e., to minimize the frame duration. Each algorithm will be suitable for a different set of system parameters. We present trade-offs between the system hardware and the algorithm' performance for various traffic patterns. These trade-offs can be used as guidelines for the system designer that needs to decide the system hardware for a given traffic pattern and required system performance. Moreouer, for a given system hardware and traffic patterns, each node can distributively decide which algorithm should be used, i.e., the algorithm that will maximize the system performance.     

Prototype of time digitizing system for BESⅢ endcap TOF upgrade

The prototype of a time digitizing system for the BESⅢ endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.     

Prototype of time digitizing system for BESⅢ endcap TOF upgrade

The prototype of a time digitizing system for the BESⅢ endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.     

Hardware for multi-superconducting qubit control and readout

We have developed an electronic hardware system for the control and readout of multi-superconducting qubit devices. The hardware system is based on the design ideas of good scalability, high synchronization and low latency. The system, housed inside a VPX-6U chassis, includes multiple arbitrary-waveform generator (AWG) channels, analog-digital-converter (ADC) channels as well as direct current source channels. The system can be used for the control and readout of up to twelve superconducting transmon qubits in one chassis, and control and readout of more and more qubit can be carried out by interconnecting the chassis. By using field programmable gate array (FPGA) processors, the system incorporates three features that are specifically useful for superconducting qubit research. Firstly, qubit signals can be processed using the on-board FPGA after being acquired by ADCs, significantly reducing data processing time and data amount for storage and transmission. Secondly, different output modes, such as direct output and sequential output modes, of AWG can be implemented with pre-encoded FPGA. Thirdly, with data acquisition ADCs and control AWGs jointly controlled by the same FPGA, the feedback latency can be reduced, and in our test a 178.4 ns latency time is realized. This is very useful for future quantum feedback experiments. Finally, we demonstrate the functionality of the system by applying the system to the control and readout of a 10 qubit superconducting quantum processor.     

Three-Dimensional Information Acquisition Using a Compound Imaging System

The TOMBO (thin observation module by bound optics) system is a compound imaging system inspired by a biological visual system. Various interesting features can be utilized in the applications of the TOMBO system: in this paper, we present an effective method for three-dimensional information acquisition. An image captured by the TOMBO system is composed of multiple images observed from several viewpoints. Distance between the TOMBO system and an object can be estimated using disparity of the captured images. A new method for estimation of the object distance is introduced. In the experiment, multiple object distances can be successfully estimated by the proposed method. Using the obtained distances for image reconstruction, we can generate a composite image focussing on multiple objects.     

ADS注入器Ⅱ超导磁铁电源控制器的设计

针对加速器驱动次临界系统(ADS)注入器Ⅱ对超导磁铁电源系统的要求,设计了一款主要由光纤模块、数模转换器(DAC)和模数转换器(ADC)相关电路组成的高稳定度的超导磁铁电源控制器。提出了一种基于数字电位器(DCP)与现场可编程门阵列(FPGA)所组成的DAC,该DAC可以实现高稳定度的超导磁铁电源的控制,电源电流值通过该DAC给定,其电压给定输出稳定度优于2×10-5,完全满足超导磁铁电源系统5×10-5量级的稳定度要求。最后给出了系统的实际测试数据,验证了设计的合理性和使用的可靠性。     

Analytical model development of an eddy-current-based non-contacting steel plate conveyance system

A concise model for analyzing and predicting the quasi-static electromagnetic characteristics of an eddy-current-based non-contacting steel plate conveyance system has been developed. Confirmed by three-dimensional (3-D) finite element analysis (FEA), adequacy of the analytical model can be demonstrated. Such an effective approach, which can be conveniently used by the potential industries for preliminary system operational performance evaluations, will be essential for designers and on-site engineers.     

静态随机访问存储器型现场可编程门阵列辐照效应测试系统研制

 在调研静态随机访问存储器型现场可编程门阵列(FPGA)器件空间辐照效应失效机理的基础上,详细论述FPGA辐照效应测试系统内部存储器测试、功能测试及功耗测试的实现原理,给出了系统的软硬件实现方法。所建立的系统可以测试FPGA器件的配置存储器翻转截面、块存储器翻转截面、功能失效截面、闭锁截面等多个参数,其长线传输距离达到50 m以上,最大可测门数达到了100万门,为FPGA辐照效应研究提供了测试平台。     

基于遗传算法的统一混沌系统比例-积分-微分控制

提出了一种并行遗传算法用于比例-积分-微分(PID)控制器结构和参数的同时优化,遗传算法采用浮点数和二进制混合矩阵编码.优化后的PID控制器用于统一混沌系统的控制,仿真研 究结果表明：1) 用一个比例-积分(PI)调节器可将统一混沌系统控制到零不动点； 2) 用 三个PI调节器可将统一混沌系统控制到非零不动点；3) 所提出的并行遗传算法具有很强的 全局优化能力,较好地克服了简单遗传算法的过早收敛问题；4) 整个控制系统具有很好的调 节品质和很强的鲁棒性,对PID调节器用于控制混沌系统具有重要的参考价值. 关键词： 混沌 统一混沌系统 遗传算法 比例-积分-微分控制     

EPES sampling depth paradox for overlayer/substrate system

An unexpected interface effect for the sampling depth of elastic peak electron spectroscopy (EPES) in applications to the overlayer/substrate system has been found. The sampling depths expressed as an information depth (ID) for Au/Ni and Rh/Al systems and selected energies in the range 200–10,000 eV were obtained from Monte Carlo (MC) simulations for typical for EPES cylindrical mirror analyser (CMA) configuration. It turned out that deep minimum in the ID dependence on the interface depth can exist. For example, for Rh/Al system at the energy of 2000 eV the ID can be smaller by a factor of two than the ID for the system elements. This effect can be explained in terms of the differential cross sections.     

一个一维周期驱动哈密顿系统的实例及混沌控制

提出一种新的周期驱动非线性不可积哈密顿系统模型,并对其特性进行了讨论.通过简单的非反馈控制装置对这一系统进行混沌控制,将其混沌轨道分别控制在周期,准周期及指定混沌轨道上.与以往的控制方法不同的是,控制项仅是一结构简单、可调节的限位装置.为保守系统混沌控制的实际应用提供可供选择的途径     

Flat Filter Based on a Chirped Super Moiré Grating

In this paper, super Moiré grating (SMG) with multiple superimposed gratings, in the best of our knowledge, is studied at first time. A flat multichannel transmission filter based on a chirped SMG with three superimposed gratings can be achieved, which benefits wavelength-division multiplexing (WDM) system. At the same time, a reflection filter can also be obtained in a chirped SMG, which can be used as an optical add/drop multiplexer filter for WDM system.     

低温光致发光微计算机测试系统

低温光致发光微计算机测试系统(PL-PC)是应用IBM-PC微计算机和先进的具有软件的数据采集系统(Keithley DAS Series 500)等配接到低温光致发光测量设备上,对固体材料的光致发光进行测试.特别是对Ⅲ-V族,Ⅱ-Ⅵ族半导体化合物的测试显著提高了效率和精度.实现了理想的测量控制、数据采集、数据处理和管理.对数据采集采用光编码器等作直接同步控制,采集精度从10Å-0.04Å可调,采集灵敏度<1mV,对测试结果(数据、谱线、计算结果、测试条件等)可以显示、记录、打印、存储等多种方式任选输出,全部过程在程序控制下进行.应用程序使用BASIC和Soft500写成,采用“菜单”方式,模块结构,使用方便,灵活、稳定、可靠.     

Analysis of the neutralino system in supersymmetric theories

Charginos and neutralinos in supersymmetric theories can be produced copiously at colliders and their properties can be measured with high accuracy. Consecutively to the chargino system, in which the SU(2) gaugino parameter , the higgsino mass parameter and can be determined, the remaining fundamental supersymmetry parameter in the gaugino/higgsino sector of the minimal supersymmetric extension of the Standard Model, the U(1) gaugino mass , can be analyzed in the neutralino system, including its modulus and its phase in CP–noninvariant theories. The CP properties of the neutralino system are characterized by unitarity quadrangles. Analytical solutions for the neutralino mass eigenvalues and the mixing matrix are presented for CP–noninvariant theories in general. They can be written in compact form for large supersymmetric mass parameters. The closure of the neutralino and chargino systems can be studied by exploiting sum rules for the pair-production processes in collisions. Thus the picture of the non–colored gaugino and higgsino complex in supersymmetric theories can comprehensively be reconstructed in these experiments. Received: 24 August 2001 / Published online: 21 November 2001     

Complex-enhanced chaotic signals with time-delay signature suppression based on vertical-cavity surface-emitting lasers subject to chaotic optical injection

A chaotic system is constructed on the basis of vertical-cavity surface-emitting lasers (VCSELs), where a slave VCSEL subject to chaotic optical injection (COI) from a master VCSEL with the external feedback. The complex degree (CD) and time-delay signature (TDS) of chaotic signals generated by this chaotic system are investigated numerically via permutation entropy (PE) and self-correlation function (SF) methods, respectively. The results show that, compared with master VCSEL subject to optical feedback, complex-enhanced chaotic signals with TDS suppression can be achieved for S-VCSEL subject to COI. Meanwhile, the influences of several controllable parameters on the evolution maps of CD of chaotic signals are carefully considered. It is shown that the CD of chaotic signals for S-VCSEL is always higher than that for M-VCSEL due to the CIO effect. The TDS of chaotic signals can be significantly suppressed by choosing the reasonable parameters in this system. Furthermore, TDS suppression and high CD chaos can be obtained simultaneously in the specific parameter ranges. The results confirm that this chaotic system may effectively improve the security of a chaos-based communication scheme.     

Study on welded seam recognition using circular laser vision sensor

A novel visual robotic arc welding system based on circular laser vision sensor is developed. After image de-noising, image segmentation, and image thinning, the relation of depth value of workpiece and off-axis angle γ, three-dimensional (3D) calculation, and seam tracking experiments are carried out. Finally, the error for seam tracking system is analyzed. The results show that 1) 3D information can be obtained using the proposed visual robotic arc welding system and the real-time seam tracking is realized; 2) the seam tracking error is small enough for gas tungsten arc welding (GTAW) process, and this system can be used for seam location and seam tracking or seam finder.     

Invariant Solutions of the Yang–Mills Field Equations Coupled to a Scalar Doublet

The Yang–Mills system of field equations which includes coupling to an SU(2) scalar matter doublet is developed. It is shown that an SU(2) current for a scalar matter doublet can be developed. The basic structure which fits the Yang–Mills system is somewhat different from the case of the scalar triplet. Using this form for the scalar current, it is possible to write down the Yang–Mills system which couples to the scalar matter doublet. It is shown that several sets of solutions to this system of equations can be obtained.     

Analytical solution for an anomalous hollow beam in a fractional Fourier transforming optical system with a hard aperture

Based on the fact that a hard aperture function can be expanded into a finite sum of complex Gaussian functions, the approximate analytical expressions for the output field distribution of an anomalous hollow beam (AHB) passing through an apertured fractional Fourier transform (FRT) system are derived. By using the approximate analytical formulae and diffraction integral formulae, the propagation properties of an AHB in circular and rectangular apertured FRT system are studied numerically. The results show that this method provides a convenient tool for studying the propagation properties of an AHB passing through apertured FRT system, and the apertured FRT system can be applied to laser beam shaping conveniently.