LiNbO3马赫曾德尔调制器任意偏置工作点锁定技术的研究

在传统LiNbO3马赫曾德尔调制器偏置控制理论的基础上,提出了一种基于快速傅里叶变换(FFT)算法和低频小信号扰动的谐波响应反馈控制方法,实现了一种与调制器输入光功率及插入损耗无关、任意工作点可偏置并锁定的精密光电控制系统。利用比例积分微分（PID）控制方法,实现了任意工作点偏移小于0.5°的控制精度,实验结果亦证明该控制系统能够实现强度调制器任意工作点的偏置及锁定。这些结果对于将LiNbO3强度调制器稳定在最佳工作点并实现高速长距光纤通信系统是很有帮助的。     

ALMA Band 10 tertiary optics

The ALMA Band 10 (787–950 GHz) receiver is a dual-polarization heterodyne system based on NbTiN superconducting technology. The coupling of energy from the secondary mirror of the ALMA Cassegrain antenna to the Superconductor–Insulator–Superconductor (SIS) mixers used for down-conversion is achieved by a frequency-independent optical system composed of two elliptical mirrors to focus and redirect the incoming radiation, a wire-grid to separate orthogonal linear polarizations and two corrugated horns, one for each polarization and SIS mixer. In this paper, we present the ALMA Band 10 tertiary optics design and evaluate its performance by quasi-optical techniques, Physical Optics simulations and measurements. Detailed results of secondary aperture efficiency and beam-squint are provided. The characterization procedure described in this paper can be used for any optical system at around 1 THz.     

数字束流位置探测器通道自动增益校准方法的研究与实现

在现有硬件基础上,基于BPM测量准确度的需求,在自制的电子学FPGA芯片内,通过Verilog语言实现了一种数字BPM采样数据增益自动校准的设计。首先介绍了自动增益校准模块的系统总体设计;然后对模块的实现方法做了详细说明,设计并搭建了ADC数据自动增益校准测试平台以验证自动增益较准模块的功能;最后介绍了该设计在BPM通道标定中的应用。实验结果表明,该方法可以实现4通道增益一致,使ADC采样后的数据幅度相同,有效解决了由通道增益不一致引起的测量偏差,以及工程应用中ADC数据幅度校准工作量大且难于操作的问题,将在BPM系统通道自动标定中发挥重要作用。     

用粒子群算法校正三片镜系统的像差（特邀）

提出将粒子群算法用于三片镜光学系统的优化设计。设计了关于曲率半径、透镜面之间的距离、玻璃折射率、系统长度等光学系统结构参数的光学评价函数,用此函数作为粒子群算法中的适应度函数,实现了对光学系统的自动寻优。给出了用粒子群算法进行三片镜光学系统设计过程实例,结果证明：用粒子群算法可以设计出球差、子午场曲、子午光线弥散值都很小的三片镜光学系统;并且用该算法进行光学设计不需要知道系统具体的初始结构,克服了现有光学设计软件高度依赖具体初始结构的缺点,可以自由控制结构参数的搜索范围,从而提高光学系统设计的智能化程度。     

Design of ternary Multiplexer and De-multiplexer circuit with optical nonlinear material (OPNLM) based switch

Multiplexer and De-multiplexer operation play a very important role in all-optical computation, communication and control. Considerable number of multiplexing – de-multiplexing scheme in digital optical processing have already been reported. A design of all-optical ternary Multiplexer De-multiplexer circuit with optical nonlinear material (OPNLM) based switch is proposed and described in this paper. Different logic states have been represented by different polarization states of light. Logical simulation is also included here. This circuit will be useful in future all-optical multi-valued logic based computing and information processing system.     

基于ACR9000控制器的自动光学检测平台设计 

针对自动光学检测（AOI）平台运行过程中的定位精度控制问题,提出了一种基于速度和加速度前馈控制与PID反馈控制的复合控制算法,该算法对输入量进行跟踪补偿控制以消除系统稳态误差,用于提高AOI平台定位精度。基于开放式的数控系统设计方法设计了AOI平台。在Matlab/Simulink环境下,构建了基于该复合控制算法的定位精度控制仿真模型,仿真结果验证了复合控制算法的有效性。将该复合控制算法作为ACR9000控制器的控制算法,并基于ACR9000控制器进行AOI平台实验研究。应用该AOI平台进行了印刷电路板（PCB）检测实验,实验结果表明文中复合控制算法能够提高AOI平台定位精度,AOI平台的定位精度满足印刷电路板检测要求,可以将该AOI平台用于印刷电路板检测。     

Design of an ultrafast all-optical NOR logic gate based on Mach-Zehnder interferometer using quantum-dot SOA

This paper proposes a design for all-optical NOR logic gate, based on Mach-Zehnder interferometer (MZI) using quantum-dot semiconductor optical amplifier (QD-SOA). In this regard, a theoretical model for an ultrafast all-optical signal processor is developed using QD-SOA to achieve high bit rate operation. We have demonstrated the NOR gate operation in two cases of with and without an optical control pulse. Simulations have been carried out at data bit rates 160 Gb/s, 200 Gb/s, and 250 Gb/s for the case that control pulse is not applied, and also at data bit rates 1 Tb/s and 2 Tb/s in presence of control pulse which leads to improvement of gain recovery time and ultrafast NOR logic operation. In addition, quality factors of the output signals in presence and without the control pulse at different bit rates with different bias currents have been investigated for pseudo-random binary sequence (PRBS) of word length 2⁸–1.     

Some topological states in one-dimensional cold atomic systems

Ultracold atoms trapped in optical lattices nowadays have been widely used to mimic various models from condensed-matter physics. Recently, many great experimental progresses have been achieved for producing artificial magnetic field and spin–orbit coupling in cold atomic systems, which turn these systems into a new platform for simulating topological states. In this paper, we give a review focusing on quantum simulation of topologically protected soliton modes and topological insulators in one-dimensional cold atomic system. Firstly, the recent achievements towards quantum simulation of one-dimensional models with topological non-trivial states are reviewed, including the celebrated Jackiw–Rebbi model and Su–Schrieffer–Heeger model. Then, we will introduce a dimensional reduction method for systematically constructing high dimensional topological states in lower dimensional models and review its applications on simulating two-dimensional topological insulators in one-dimensional optical superlattices.     

Particle swarm optimization applied to automatic lens design

This paper describes a novel application of Particle Swarm Optimization (PSO) technique to lens design. A mathematical model is constructed, and merit functions in an optical system are employed as fitness functions, which combined radiuses of curvature, thicknesses among lens surfaces and refractive indices regarding an optical system. By using this function, the aberration correction is carried out. A design example using PSO is given. Results show that PSO as optical design tools is practical and powerful, and this method is no longer dependent on the lens initial structure and can arbitrarily create search ranges of structural parameters of a lens system, which is an important step towards automatic design with artificial intelligence.     

Growth,thermal, spectral optical and dielectric characterization of semiorganic material: Dihydroxylammonium tetrachlorostrontium(II) dihydrate

Single crystals of dihydroxylammonium tetrachlorostrontium(II) dihydrate were grown by slow evaporation solution growth method at ambient temperature. The suitability of this material for optical application was studied by UV–visible absorption and optical transmittance spectroscopic techniques. The powder X-ray diffraction (XRD) method was used to confirm the crystalline nature of the compound and it is observed that the compound crystallized in orthorhombic system. The thermal stability of the title compound was studied by thermogravimetry and differential thermal (TG–DTA) analyses. The thermal anomalies observed in the low temperature differential scanning calorimetry (DSC) study indicate the occurrence of the first order structural phase transitions in the compound. The FTIR spectrum characterizes the various chemical bonding and water molecules in the compound. The nonlinear optical property of the material was analyzed by modified Kurtz–Perry powder technique. The dielectric constant and dielectric loss of the compound decreases with increase in frequency.     

MEMS与MEMS光开关

微机电系统(MEMS)技术是一种新型制造技术,在光通信的发展中得到广泛的应用,有极大的市场价值.在整个光通信中,光开关是较为重要的光无源器件,在光网络系统中可对光信号进行选择性操作.随着光通信的日益发展,对光开关的技术要求也日益提高,利用MEMS技术制作的新型光开关具有体积小、重量轻、能耗低、集成化程度高等特点,从而日益成为研究的热点.本文简单介绍了MEMS技术和其主要特点,并较详细地阐述了MEMS技术在光通信中的应用,以及MEMS光开关的结构、发展趋势和目前存在的主要问题.     

光电稳定／跟踪平台的干扰力矩自动化检测识别

以光电稳定／跟踪平台为研究对象,通过对光电稳定／跟踪平台中存在的各种干扰力矩的力学特性进行分析和研究,提出一种新的测量稳定平台干扰力矩的方法。该方法能够实现干扰力矩的自动测量与识别,且具有较高的测量精度。通过实验,验证了该方法的可行性和优越性。     

Frequency quadrupling using an integrated Mach–Zehnder modulator with four arms

In this paper, a novel technique to realize frequency quadrupling in the radio over fiber system is proposed. The frequency quadrupling is achieved by using an integrated Mach–Zehnder modulator (MZM) consisting of a 1 × 4 multimode interference (MMI) coupler and four optical phase modulator arms. Due to the inherent optical splitting ratio and phase relations between the outputs of the MMI coupler, the optical harmonics at + 1 order and ? 3 order are generated corresponding to four times frequency of the microwave drive signal, only by setting the DC bias voltage of the main MZM at the minimum transmission point. That leads to the integrated MZM with reduced complexity compared with the conventional dual-parallel MZM. The effect of the nonideal integrated MZM, including the splitting imbalance and the bias drift, on all the sidebands is also analyzed theoretically. The following simulation results show that the slight deviation of the ideal values would not cause great degradation of the generated optical millimeter-wave signal.     

A two-dimensional self-aligning system driven by shape memory alloy actuators

The two-dimensional automatic alignment system with an optical aperture is developed. The optical aperture with four integrated photodiode cells for feedback control signal is fabricated by MEMS techniques. The translation stage of the system is driven by four shape-memory-alloy positioning actuators to realize two-dimensional (XY-plane) movement.     

VPD技术在光电产品总体设计中的应用

从系统工程方法出发，叙述了在光电系统开发的设计阶段采用VPD（Virtual Product Development）技术实现光电产品全数字化拟实平台的方法和过程。     

An effective method for improving diffraction performance of magnetostatic backward volume wave-based magneto-optic Bragg cells by using an appropriately tilted bias magnetic field in YIG film plane

The universal magneto-optic (MO) coupled-mode equations for magnetostatic waves (MSWs) and guided optical waves (GOWs) under arbitrarily tilted bias magnetic fields are presented for the first time and, as an example, applied to the noncollinear Stokes interaction between the incident TE₀-mode light and magnetostatic backward volume wave (MSBVW) excited by single-element microstrip line transducer in yttrium–iron–garnet (YIG) film. Our calculation indicates that, for the case of magnetization parallel to the MSBVW propagation direction, the diffraction efficiency (DE) is equal to the mode-conversion efficiency of the diffracted lights (MCDE) and the calculated curve of relative DE for the MSBVW-based MO Bragg cell in pure YIG waveguide is in good agreement with the experimental data. In contrast, the diffraction performance can be greatly improved by optimizing the bias magnetic field and the DE gain can be increased by 6.3 dB in the tangentially magnetized film. The angular dependences of the DE and the corresponding Bragg angle upon the magnetization direction are also discussed in the paper.     

SXDG-1型汽车前照灯全自动检测仪的微机控制

SXDG—1型汽车前照灯全自动检测仪是用于检测汽车前照大灯光轴的偏斜情况及发光强度并进行定量检验的专用设备。它可以自动测出有关参数,并予以数字显示和打印输出。本文介绍了该仪器的主要性能、工作原理及微机控制系统(包括硬件结构和软件设计思想等)。     

神光Ⅲ主机搭载平台双光路自动瞄准系统

神光Ⅲ主机靶室中用来搭载多种物理诊断设备(条纹相机、分幅相机等)的平台要求具有很高的定位精度和工作稳定性,能方便、可靠地实现对靶室内打靶目标的瞄准,为此设计了一种双光路自动调整与瞄准装置,其位置精度可以保证20μm范围内。搭载平台采用了一套双光路成像系统和一套三自由度运动部件构成瞄准系统。在瞄准系统中,应用视觉伺服控制技术,实现了搭载平台对打靶目标的高精度自动瞄准。搭载平台已经安装到神光Ⅲ主机装置上进行了自动瞄准精度检测,得到径向(z)和指向(x,y)的瞄准调整精度分别为14,11,12μm;实际搭载了分幅相机进行激光打靶考核验证,通过物理实验得到了X光焦斑图像,表明该自动瞄准调整系统满足工程使用要求。     

基于倒置光学系统的油污染度光电检测研究

油液污染的检测与分析是控制油液污染、了解设备工况、实现设备诊断的重要手段之一。基于图像处理原理,设计了由倒置光学系统、精密机械结构、4轴联动数控和油液传输系统组成的油液污染度光电检测系统,并制作出科研样机。该样机使用倒置光学显微成像系统,借助高精度快速实时自动调焦机构,由CCD快速获取被测油液的数字显微图像,通过图像分析与处理,得到油液污染信息。该系统具有检测精度高、实时性强和性价比高的特点。     

Impact of interferometer delay time on the performance of ODSB-SC RoF system with wavelength interleaving

In this paper, we investigate the impact of interferometer delay time in a 5 Gb/s optical double sideband-suppressed carrier (ODSB-SC) RoF system transmitting two wavelength interleaved radio frequency (RF) signals at 10 and 15 GHz over an optical fiber. Here, an optical Mach–Zehnder modulator is used for both optical carrier suppression and signal modulation. At the receiver, delay interferometer is used for the separation of RF frequency signals. We analyze the performance of the RoF system by varying the value of delay time of interferometer from 0.02 to 0.14 ns. The result shows that the RoF system performance is optimum for the time delay of 0.1 ns. Further, the optical spectrums, RF spectrums and eye diagrams of two interleaved RF signals have been compared.