高功率激光器参数测量与集成控制研究
文献类型：学位论文
| 作者 | 惠宏超 |
| 学位类别 | 博士 |
| 答辩日期 | 2016 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 林尊琪 |
| 关键词 | 参数测量 Fuzzy-PID控制 MonteCarlo模拟 宽带放大 测量不确定度 超短脉冲 控制系统 EPICS |
| 其他题名 | Research on parameter measurement and integrated control in high-power laser system |
| 中文摘要 | 高功率激光驱动器的规模急剧增长，技术实施愈加复杂，输出指标要求迅速提升，为满足ICF（Inertial Confinement Fusion）实验的监控需求，并保证装置的安全可靠运行，必然要求对装置进行精密化控制，而精密化控制的实现必将对装置的参数测量与集成控制提出新的要求和更高挑战。与此同时，激光性能运行模拟系统LPOM（Laser Performance Operations Model）的发展也极大的促进了装置控制的精密化水平。 高功率激光驱动器参数测量的目标是利用光学取样系统、光电探测器等设备组成的精密诊断系统，通过计算机控制系统，实现对采样光束的直接或间接测量，提供装置的运行状态结果和各种技术指标参数。而测量结果往往受到取样精度和探测器性能的直接影响，尽而影响系统的控制精度，因此，参数测量对元件的取样率及取样均匀性和探测器特性都有很高的要求；同时物理实验对皮秒脉宽及其时间波形的精密监测也提出了更高的要求。激光驱动器集成控制是参数测量日益规模化、装置控制不断精密化、复杂化的必然要求和结果，其目标是利用智能控制技术、软件技术、系统集成技术和网络等最新技术开发激光驱动器集成控制系统，对激光参数进行实时监视，对监控单元进行精密化控制，协调各分系统，最终实现装置的安全可靠运行。而提炼各系统的关键参数并分析其控制需求，对集成控制方案的设计和选择能够提供重要依据，与此同时，控制系统分别对能量反馈控制、自动准直控制和宽带光放大输出时间波形预测的精确性、可靠性和时效性同样提出了新的挑战。 本学位论文以高功率激光驱动器的精密控制技术为主线，主要在参数测量和装置的集成控制方面，分别开展了一系列相关的理论计算和实验研究工作： 1.以神光II-XX装置为例，提炼了各分系统的关键参数，分析了各参数的物理意义和监控需求。在此基础上结合激光装置的实际应用需求，系统的给出了激光装置关键控制参数需求表，并在EPICS（Experimental Physics and Industrial Control System，实验物理与工业控制系统）应用于神光II装置的控制开发过程中得到了实际应用。 2.分系统精密化反馈控制研究：1）在分析了前端分系统激光能量调整及控制精度需求之后，提出基于fuzzy-PID的控制算法，实现对前端能量输出的快速高精度的反馈调整，理论计算表明该方法可提高系统的控制精度及鲁棒性。2）为提升自动准直图像处理结果的可靠性，提出了一种采用蒙特卡洛方法对图像噪声进行预处理的计算方法，理论分析表明该方法对衍射、高斯等常见噪音有较好的预处理结果。3）针对高功率激光理论模拟控制需求，把基于极化强度时域解析法引入宽带基频光放大输出时间波形理论计算，以装置的双程放大为模型并利用特定带宽的脉冲波形数据进行校验，计算结果表明：该方法的计算效率较传统的加窗傅里叶变换方法有大幅提升。 3.在单次相关脉宽测量方法中，针对激光近场强度分布不均匀对测量结果的影响，创新的提出了基于近场强度关联的皮秒脉宽测量方案，模拟分析结果表明：该方法能够利用被测光脉冲的近场分布和畸变后的自相关结果，通过数据分析和软件计算解调出较为准确的脉宽数据。完成了数据处理和软件控制等工作，实现了测量单元的时间分辨率在线标定。为了进一步得到皮秒脉冲的时间波形，分析了自相关和互相关信号的特征，试图通过互相关函数拟合的方法来还原被测脉冲的时间分布，实验结果表明：该方法能够实现具有双峰结构和三峰结构的皮秒脉冲时间分布诊断，可作为获取ps脉冲时间波形信息的一种有效辅助手段。 4.为满足大口径光学元件透反射率及膜层均匀性测量需求，结合课题组现有基础，设计并研制了一套大型机械扫描机构，该平台能够实现对540mmX420mmX70mm范围内的光学元件进行扫描测量，重复测量精度优于0.1%，绝对测量精度优于1%，达到了较高水平。 5.基于双光路原理，首次采用相关叠加法实现了在1053nm运行波段的光电探测器线性度和面响应均匀性的精密测量，该平台具有近7个数量级的动态响应范围，能够满足各种光电探测器的响应特性测量。 |
| 英文摘要 | The size of the high-power laser driver is increasing sharply, the technical implementation is very complicated, and the output-requirement is improving rapidly. To meet the supervisory control demand of ICF (Inertial Confinement Fusion) experiment and ensure safe and reliable operation of the driver, the precision control is necessary and inevitable in high-power laser. And that, realizing precision control will certainly put forward new requirements and higher challenge to parameter measurement and integrated control of laser. At the same time, the development of laser performance operations model (LPOM) also greatly promoted the precision control level of laser device. The purpose of parameter measurement in high-power laser driver is to use the precision diagnostic systems controlled by the computer systems to realize direct or indirect measurement for sampling beams, and the diagnostic systems composed of optics sampling systems, photoelectric detectors and other equipment. It provides the laser running state results and technical parameters. But the measurement results are always affected by the sampling systems and the detector performance directly and further affected the system control precision, therefore, parameter measurement have very high requirements for the sampling rate and sampling uniformity of optical components and the detector characteristics. Meanwhile, physics experiment also put forward high request to precision supervisory of picosecond pulse width and its temporary shape. Integrated control of the laser device is inevitable requirement and result due to the large-scale, precise and complicated development of parameter measurement, the purpose is development a set of integrated control systems for the laser driver making use of the latest technology, such as intelligent control technology, software technology, system integration technology, network technology, and so on. The control systems can real-time monitoring all the key parameters, control the supervisory unit, coordinate the subsystem and finally realize the safe and reliable operation of the laser device. Analysis of the key parameters and control requirements of each subsystem can provide guidance to the design of control scheme and selection. Moreover, the control system also proposed the new challenge to the accuracy, reliability and timeliness of some sub-unit respectively, such as laser energy control, automatic collimation and the output temporal shape prediction of broad-band long-pulse amplifier. The main line of this paper is the precision control technology to high-power laser, mainly include parameter measurement and integration control of laser device. We carried out a series of related theoretical calculation and experimental research: 1.As SG-II×× an example, the key parameters of each subsystem are extracted. The parameters physical meaning and monitoring requirements are analyzed. Based on this basis and combined with the laser practical application requirements, we give the key control parameters requirements tables of laser device systematically, and have practical applications during the development process of EPICS applied to SG-II control system. 2.The precision feedback control research of subsystems. 1) After analysing the laser energy adjustment and feedback control precision demand of front-end subsystem, we propose the Fuzzy-PID control algorithm to realize the energy ouput feedback control rapidly and highly precision. The theoretical calculation results show that the algorithm can improve the control accuracy and robustness. 2) To improve the reliability of automatic collimation image processing, based on the Monte Carlo method, a pretreatment method of image noise is proposed. Theoretical analysis shows that this method has a good pretreatment result to common image noise, such as diffraction/gaussian and so on. 3) Aiming at the theory simulation control requirements of high-power laser, the analytic electric polarization in the time domain is introduced into theoretical calculation of fundamental-frequency broad-band laser amplifier output waveform. The two-pass amplification in laser device was selected as a model, then using a particular bandwidth of pulse waveform to validate. The results show that the engineering efficiency of new algorithm can be significantly increased. 3.In the measurement method of single relative pulse width, due to the uneven distribution of laser near-field intensity affect the measurement result, an innovative scheme was propose to measure the pulse width based on the near-field intensity association. Simlulation results show that the accurate pulse width can be analyzed and demodulated based on the near-field distributionthe of measuring pulsed and distorted autocorrelation results. The data processing and control software are finished. The time resolution online calibration of system is realized. In order to further get the picosecond pulse waveform, the characteristics of autocorrelation and cross-correlation signal are analysed, we propose a new method to restore the temporal distribution of measuring pulsed by use of cross-correlation function fitting. The experimental results show that this new method can obtain the information of ps temporal shape with two and three peak structure. And this method can get ps pulse time waveform information as an effective auxiliary means. 4.To meet the transimittance, reflectance and film uniformity measurement requirements of large-optical elements, based on the existing foundation, a set of large mechanical scanning mechanism is designed and developed, this platform can scanning measurement the optical element in the range of 540mm×420mm×70mm. The system repetition measurement accuracy is better than 0.1%, absolute measurement precision is better than 1%. Its precision reaches to a high level. 5.Based on the principle of dual-path light, we use the relevant superposition method for the first time, and the precision measurement of photoelectric detector linearity and surface-response uniformity in 1053 nm was realized. This platform has at least 7 orders of magnitude of dynamic response range, and the system can accurately measure the characteristics of kinds of photoelectric detector in laser device. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15966]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 惠宏超. 高功率激光器参数测量与集成控制研究[D]. 中国科学院上海光学精密机械研究所. 2016. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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