神光-Ⅲ主机X光双通道单分幅成像系统研制

根据神光-Ⅲ激光器的运作方式和靶室结构,成功研制出用于神光-Ⅲ激光器装置的X光双通道单分幅相机系统。该相机系统主要由针孔成像组件、MCP选通技术型分幅相机和科学型可见光CCD三部分组成,同时系统具有线下瞄准、线上三维调节的功能。系统中针孔直径为10μm,放大倍率为5,分幅相机单画幅宽度13mm,长度36mm,曝光时间0.5~10.0ns可调。在神光-Ⅲ主机装置上成功完成了对此系统的性能考核,结果表明,该系统完全能够应用于神光-Ⅲ装置上,而且与传统方式上的针孔成像组件配接X光CCD组成的成像系统相比,具有更好的信噪比和空间分辨。     

Design of a very high frame rate camera based on an asynchronous CCD driving method

A very high frame rate camera is designed based on an innovative CCD driving method. The CCD driving method is mainly implemented on frame transfer CCDs. Asynchronous drive timing sequences are applied in the image and storage section of the CCDs. Several rows of the charge in the image section are binned onto the same row in the storage section, and there are the same number of images to be stored in the storage section before they are read out. Based on the new driving method, the frame transfer CCDs can work at a very high frame rate in acquiring burst images though the reading speed remains at a lower level. A very high frame rate camera is designed in this paper. The innovative CCD driving method is mainly of concern. An e2v's CCD60 is adopted in the camera system, whose full size resolution is 128×128, and the up most frame rate is 1000 Hz in the conventional CCD driving method. By using the presented method, the CCD60 based imager is capable of operating at up to 40000 frames per second (fps) at a recognizable resolution of 128×32. Comparing cameras using traditional binning and region of interest technologies, the frame rate is normally less than 5000 fps while the resolution is only 32 × 32 lett.     

A 3 × 6 arrayed CCD X‐ray detector for continuous rotation method in macromolecular crystallography

A 3 × 6 arrayed charge‐coupled device (CCD) X‐ray detector has been developed for the continuous‐rotation method in macromolecular crystallography at the Photon Factory. The detector has an area of 235.9 mm × 235.9 mm and a readout time of 1.9 s. The detector is made of a 3 × 6 array of identical modules, each module consisting of a fiber‐optic taper (FOT), a CCD sensor and a readout circuit. The outputs from 18 CCDs are read out in parallel and are then digitized by 16‐bit analog‐to‐digital converters. The advantage of this detector over conventional FOT‐coupled CCD detectors is the unique CCD readout scheme (frame transfer) which enables successive X‐ray exposures to be recorded without interruption of the sample crystal rotation. A full data set of a lysozyme crystal was continuously collected within 360 s (180° rotation, 3 s/1.5° frame). The duty‐cycle ratio of the X‐ray exposure to the data collection time was almost 100%. The combination of this detector and synchrotron radiation is well suited to rapid and continuous data collection in macromolecular crystallography.     

高动态范围激光等离子体诊断系统及其在惯性约束聚变实验中的应用

基于高功率激光等离子体X射线辐射谱特性,设计和研制了一种大画幅高动态范围MCP选通型分幅相机. 单画幅宽度13mm,长度36mm,曝光时间0.5—5ns可调.与X射线CCD比较,系统在1.0—10keV的谱响应相对平整,无高能增强效应.利用高功率激光打靶实验进行了性能考核实验,结果表明,系统的信噪比明显好于X射线CCD系统,动态范围大于3×10³. 系统已经在神光Ⅱ装置ICF物理实验中获得成功应用. 关键词： 动态范围 谱响应 激光等离子体诊断 分幅相机     

基于CCD电极直接驱动控制的双脉冲发光图像高速曝光技术原理研究

电荷耦合器件(CCD)是一类高性能的光电成像器件,具有成像阵列大、图像质量好的特点。但由于正常工作驱动时序复杂,工作帧频一般较低,无法满足较高成像帧频的要求。针对一种双脉冲发光图像的高速高分辨高质量成像要求,根据CCD信号电荷收集及转移的电极驱动特性,选择合适的CCD类型,以电荷转移时序为时间分隔界限,设计了一种电极直接进行控制的时序,实现了两个光脉冲图像的分离积分及信号转移、读出等,完成了双脉冲发光图像的等效高帧频曝光的原理验证,在保持CCD原有高成像质量的情况下获得了μs级间隔的两幅图像可分辨的能力,并实现了一种二分幅相机系统。     

Design of a very high frame rate camera based on an asynchronous CCD driving method

A very high frame rate camera is designed based on an innovative CCD driving method. The CCD driving method is mainly implemented on frame transfer CCDs. Asynchronous drive timing sequences are applied in the image and storage section of the CCDs. Several rows of the charge in the image section are binned onto the same row in the storage section, and there are the same number of images to be stored in the storage section before they are read out. Based on the new driving method, the frame transfer CCDs can work at a very high frame rate in acquiring burst images though the reading speed remains at a lower level. A very high frame rate camera is designed in this paper. The innovative CCD driving method is mainly of concern. An e2v's CCD60 is adopted in the camera system, whose full size resolution is 128 × 128, and the up most frame rate is 1000 Hz in the conventional CCD driving method. By using the presented method, the CCD60 based imager is capable of operating at up to 40000 frames per second (fps) at a recognizable resolution of 128 × 32. Comparing cameras using traditional binning and region of interest technologies, the frame rate is normally less than 5000 fps while the resolution is only 32 × 32 left.     

帧转移型数字相机帧转移模糊的复原

帧转移型面阵CCD相机因其诸多优点而得到了广泛的使用 ,但它也存在帧转移模糊的问题。介绍了CCD相机的几种面阵类型及其各自的一些特点 ,重点介绍了帧转移型面阵器件的工作过程 ,分析了面阵CCD器件帧转移模糊形成的原因 ,并提出了解决帧转移模糊的方法。介绍了用该方法消除帧转移模糊的实例 ,验证了方法的有效性     

A high-speed image sensing technique with adjustable frame rate based on an ordinary CCD

In the sinusoidal phase modulating interferometer technique, the high-speed CCD is necessary to detect the interference signals. The reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing technique with adjustable frame rate based on an ordinary CCD was proposed. And the principle of the image sensor was analyzed. When the maximum frequency and channel bandwidth were constant, a custom high-speed sensor was designed by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been enhanced by controlling the number of pixels of every frame; therefore, the ordinary of CCD can be used as the high frame rate image sensor with small amount of pixels. The multi-output high-speed image sensor has the deficiencies of low accuracy, and high cost, while the high-speed image senor with small number of pixels by using this technique can overcome theses faults. The light intensity varying with time was measured by using the image sensor. The frame rate was up to 1600 frame per second (f/s), and the size of every frame and the frame rate were adjustable. The correlation coefficient between the measurement result and the standard values were higher than 0.98026, and the relative error was lower than 0.53%. The experimental results show that this sensor is fit to the measurements of sinusoidal phase modulating interferometer technique.     

空间扫描型光纤法布里珀罗传感解调系统中CCD的光照度数学模型研究

针对空间扫描型光纤法布里珀罗（F-P）传感解调系统中CCD的光照度分布建立了数学模型,研究了不同帧扫描频率下CCD输出信号和信噪比。利用已设计的解调模块进行了CCD光照度分布的实验,实验结果表明,当帧扫描频率不同时,CCD各个像素输出信号电压的实验值与计算值的相对误差均小于2.5%,同一像素输出信号电压的实验值与计算值的相对误差变化数值均小于0.005,随实验所用CCD帧扫描频率变化,信噪比以184 Hz为分界点以两种变化斜率改变,验证了数学分析模型的有效性。     

Diagnosis of phasma in CCD damage process induced by laser

In this paper, the shapes of plasma produced by a Q-switched YAG laser acted repeatedly upon a CCD with MOS structure are used, to investigate the destroying process of the optoelectronic device. The experimental results of CCD destroyed by a 1.06μm laser beam with a pulse width of 15 ns are given.     

基于FPGA的全帧型面阵CCD驱动时序设计

在介绍全帧型面阵CCD的结构和特点的基础上,分析了该类型CCD的驱动信号和时序,并针对CCD442A型CCD设计出了一种基于现场可编程门阵列(FPGA)的全帧型面阵CCD驱动时序。采用集成开发环境和自上而下的模块化设计方法,实现了硬件设计的软件化,提高了开发效率。     

微通道板选通X射线纳秒分幅相机的研制

设计并研制了一种新的微通道板选通X射线纳秒分幅相机,相机系统由带有行波选通微带光电阴极的近贴聚焦分幅变像管、电控单元、针孔安装和调节系统及真空系统组成.电控单元提供相机上作需要的直流电压和脉冲开关电雎.输出图像山采用光纤面板耦合到荧光屏的CCD相机读出.采用厚50 mm的Au作为变像管光电阴极,相机谱响应范围0.1～10 keV.可获得八幅分幅图像,每幅曝光时间1 ns,2 ns和5.0 ns三档可调,像幅时间间隔分2 ns、5 ns和10 ns 三档可调.相机动态空间分辨力优于18 lp/mm,触发晃动小于100 ps,时间抖动小于5%.并可实现远距离监视、控制和数据采集.对相机静态特性和动态特性的实验标定及应用现场所获得的实验结果均表明,相机上作性能稳定,具有几何畸变小、动态范围大等特点,满足 Z-箍缩实验研究的需要.     

75帧/s准高帧频CCD摄像机74H0的特性分析

介绍了准高帧频CCD摄像机的一般概念及 75帧 /sCCD摄像机输出图像的工作原理和主要性能指标。准高帧频CCD摄像机具有 75帧 /s的图像速度 ,除了适合于弱视阅读机以外 ,还能在电视电影拍摄和相互转换应用中起到积极作用 ;另外还能在电视监控准动态运动物体和交通监控系统中作为前端传感器。由于能与PC显示器匹配 ,所以可应用到各学科研究领域的图像分析仪中     

CCD长时间积分边角亮光的实验研究

通过实验定量研究了ICX412 CCD芯片在不同积分时间下的边角亮光的强度特征,并通过对CCD表面的拍摄,发现边角亮光的出现是由于CCD感光区域周边的两个辐射光源产生的近红外辐射.分析了黑场矫正方法对图像均方差(STD)影响,并研究了在积分过程中通过降低发光区域电路供电电压,再采用黑场矫正等手段消除了边角亮光对CCD长时间积分背景强度及STD的影响.     

生物芯片扫描仪CCD背景噪声研究

冷CCD(Cool CCD)是生物芯片扫描仪的核心检测器件,其背景噪声直接影响到检测精度。CCD背景噪声可分为光子噪声、热噪声、读出噪声和量化噪声。其中热噪声Hn与读出噪声Rn最为核心,采用拍摄暗场帧的方法对其进行实验研究。实验表明对于某一指定曝光时刻,背景噪声图像各像素的强度可认为符合正态分布,并可将均值与标准方差的估计值即■与■作为其相应正态分布的表征参数。■与■的95%置信区间较小,最大区间长度分别占■与■的0.16%和28.36%。在此基础上讨论了温度、曝光时间对均值与方差的影响。     

Z“箍缩”的时间分辨测量技术研究

针对在阳加速器上进行的Z箍缩内爆实验所要求的超快分幅摄影技术研究,主要利用八个微通道板构成摄影系统的快门以达到时间分辨的要求,同时解决了在阳加速器上的精密同步问题以使系统可以稳定、可靠地一次拍摄到八幅图像,图像间隔最小为10 ns,曝光时间可达到3 ns.该技术以分幅原理获得大幅面的图像数据,具有图像特征清晰、空间信息详细的特点,为Z箍缩过程的研究提供了翔实的实验数据.     

利用综合复用技术拓展数字全息显微系统中的记录视场

为了解决现有数字全息显微系统中高分辨率与大记录视场无法同时兼得的问题, 提出了一种在不牺牲分辨率的前提下拓展数字全息显微记录视场的方法. 该方法中运用了波长不同、偏振态不同的四路相互不相干的探测物光, 同时探测被测样品四个相邻的不同区域, 并使这四束探测物光分别与其相应的参考光相干, 在记录面上同时记录下含有被测样品不同区域信息的复合全息图. 将获得的复合全息图经过频谱变换和数字滤波, 分别重构出所记录区域的振幅和相位分布.最后通过图像拼接和图像融合技术, 可实现接近原记录视场四倍的大视场数字全息显微记录. 该方法在测量过程中无需移动记录装置、光源和被测样品, 单次曝光即可实现, 实验结果验证了本文所提方法的可行性. 关键词： 数字全息显微术 角分复用 偏振复用 波长复用     

Two-dimensional measurements of laser-induced breakdown in air by high-speed two-frame shadowgraphy

We present two-dimensional measurements of the laser-induced plasma development and shock wave evolution in air. The breakdown is induced by a Q-switched Nd:YAG laser (λ=1064 nm) with a pulse duration of 4 ns. To study these fast laser-induced phenomena, we have developed a high-speed, two frame shadowgraph method. It enables 2D visualization of a laser-induced event in two time instances, which are delayed by an arbitrary time interval in the range from 300 ps to 30 ns. The established method is based on 30 ps, green (λ=532 nm), and linearly polarized laser pulse, which is split into two orthogonally polarized illumination pulses for direct and delayed illumination of the breakdown area. Exploiting polarization of the probe pulses, we capture two temporally and spatially separated frames with two CCD cameras. Special attention is given to the subsequent data processing, especially to the minimization of the systematic error due to alignment of both images, and to the determination of 2D velocity distribution from the captured image pairs.     

Pulsed digital micro-holography of femto-second order by wavelength division multiplexing

Wavelength division multiplexing (WDM) used in a pulsed digital micro-holographic system to record ultra-fast processing of the order of femto-second is reported for the first time, where a BBO crystal is used to generate harmonic wave of the incident laser wave, and both of the basic and the frequency doubled waves are time-delayed and introduced to a Michelson’s interferometer to record two sub-holograms with different spatial frequencies on a single frame of a CCD by WDM. In the experiment, an ultra-fast dynamic process of air ionization induced by a single femto-second laser pulse is holographic recorded by this system, and both of intensity and phase difference images digitally reconstructed are obtained through Fourier transformation and digital filtering, which shows clearly the dynamic process of formation and propagation of the plasma, with a time resolution of the order of femto-second.     

超高动态CCD摄像机63W1的特性分析

介绍了超高动态CCD摄像机 63W 1的特性。 63W系列摄像机是由敏通公司制造的技术先进的CCD摄像机。具体分析了M 88DSP双曝光、双 16Mbit存储及高速运算合成处理的工作原理。给出了在同幅景物不同照度情况下的CCD视频图像效果。简述了Mintron 63W 1CCD摄像机各项性能指标 ,并与传统CCD摄像机进行了比较。