Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences
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Study of High-speed Three-dimensional Imaging Lidar Technology
No full text自上世纪九十年代以来，三维成像激光雷达技术迅猛发展，相对于二维图像，三维成像激光雷达在获得目标二维灰度图像的同时，也可以获得目标的三维图像，图像信息更加丰富，能够更加准确地描述目标的特征，因此，在工程测绘、消费电子、工业生产、航天和军事等方面都有广泛的应用。随着无人驾驶技术、无人机蔽障、机器视觉等新兴技术的发展，对三维成像激光雷达的成像速度、体积、重量等要求也越来越高，基于机械扫描式的三维成像激光雷达技术已经逐渐不能满足新兴应用的需求。本文针对高速三维成像激光雷达技术展开研究，使之满足对三维成像速度要求较高场合的应用需求。 本文概述了目前国内外实现三维成像几种主要的技术途径，介绍了各个技术途径的研究现状和技术特点，对三维成像激光雷达的工作原理进行了理论分析。论文首先进行了机械扫描三维成像激光雷达的研究，分析了其应用的局限性，然后，在国内目前现有条件的基础上，提出了两种实现高速三维成像的技术途径：非机械扫描式和无扫描式三维成像激光雷达技术，针对各个技术途径进行了相关的理论和关键技术研究，提出了系统设计方法，搭建了实验系统，并进行了大量实验，取得了一定的实验结果。 首先，论文进行了机械扫描三维成像激光雷达技术的研究，该技术采用高精度电机带动转镜实现光束的扫描，采用直接飞行时间测量法，结合高精度时间差测量电路，实现对目标的扫描和三维测量。论文介绍了该激光雷达系统的设计方案，搭建了激光雷达工程样机。通过实验结果发现，该技术可以较好地对静态目标进行三维成像，成像精度较高，1064.1m处的测量精度为0.24m。但是由于成像范围较大，为获得较高的点云密度，电机的扫描速度较慢，在最高角度分辨率情况下，获取一幅完整的三维图像需要26min，因此，无法满足对成像速度要求高的场合。 为提升三维成像激光雷达的成像速度，本文先提出声光扫描视频三维成像激光雷达技术，以二维声光扫描器件替代机械转镜，实现光束的高速扫描，具有响应速度较快、体积小、重量轻的优点，能够在小角度范围内实现灵活快速的扫描，便于实现对小范围目标的高速三维成像。论文介绍了二维声光扫描器件的工作机理，并详细介绍了声光扫描视频三维成像激光雷达的系统设计方案，搭建了激光雷达的工程样机。通过实验结果可以得出：该系统在分辨率为63×63时，成像速度为25fps，系统的最大成像范围为5°×5°，最大成像分辨率为240×240，在30m处的测距精度为8.9mm，对于建筑物目标，最大作用距离可达850m，最大作用距离处的测距精度为0.39m。 接着，提出无扫描混频调制的ICMOS高速三维成像激光雷达技术，该技术以一定频率差对激光光源和像增强器增益进行方波调制，回波光信号通过像增强器后产生混频光信号，光信号频率为二者调制频率差，采用高速相机对混频光信号进行采样，通过余弦波-方波鉴相法实现对回波信号相位的测量，获得目标距离，实现三维成像。论文中详细推导了该激光雷达的距离反演表达式，分析了影响测量精度的因素，介绍了系统的设计方案，搭建了实验系统，进行了成像实验，分析了实验结果，并提出了进一步提升系统性能的改进方法。通过实验结果可知，该激光雷达目前的性能参数为：三维成像速度为200fps，分辨率为256×256时，激光雷达的成像范围为4°×4°，最大作用距离为9m，最大测距精度为1.1m。若增大激光的发散角和功率，其最大成像分辨率可达1024×1024，最大成像范围可达16°×16°。通过选用性能更好的探测器件可以改善系统的性能。 最后，对以上三种技术进行了分析比较，机械扫描三维成像激光雷达成像范围大、测量精度高，但成像速度慢；非机械扫描式三维成像激光雷达的测量速度有所提升，且测量距离远、测量精度高，但成像范围小，成像速度也需要进一步提升；无扫描三维成像激光雷达具有探测范围大、分辨率高、成像速度快的优点，但激光功率要求较高、测距精度较低、测量距离近。该三种技术各有优缺点，在实际应用中，应根据需求，选用合适的技术方案。Since the 1990s, three-dimensional (3D) imaging lidar technology has developed rapidly. Compared with the two-dimensional imaging, 3D imaging lidar can measure the 3D image of the target, at the same time obtaining its two-dimensional gray image, which makes characterizing the target more accurately. It had been widely used in engineering surveying, consumer electronics, and industrial production, aerospace and military. With the development of unmanned technology, unmanned aerial vehicles obstacle avoidance, machine vision and other emerging technologies, we require that laser radar has better performance, such as faster imaging speeds, smaller, lighter, etc. The traditional 3D imaging lidar which based on mechanical scanning can’t meet the needs of practical applications. In this paper, we studied the technology of high-speed 3D imaging lidar. This paper outlined the current main technical ways to high-speed 3D imaging, and analyzed the research status and technical characteristics of each approach. This paper studied mechanical scanning 3D imaging lidar, analyzed the limitations of its application. On the basis of the existing domestic conditions, the paper put forward two ways to achieve high-speed 3D imaging: non-mechanical scanning way and non-scanning way. This paper did the theory and key technology research for each technology way, proposed the system design methods, set up the experimental system, and obtained some experimental results. Firstly, the paper studied mechanical scanning 3D imaging lidar technology. the technology used high-precision motor to drive rotating mirror, and combined with high-precision time detection circuit, it can achieve scanning and three-dimensional measurement . This paper introduced the design of lidar system. From the experimental results, we found that the technique can get better performance when imaging static target, and can obtain high imaging precision. The ranging precision is 0.24m at 1064.1m distance. However, due to the larger imaging range, in order to obtain a higher point density, the scanning speed of the system is slow. At the case of highest angular resolution, the system need 26 minutes to obtain a complete 3D image. Therefore, it unable to meet the requirements of high speed imaging application. To enhance the imaging speed of 3D imaging lidar, the paper presented a novel 3D video imaging lidar system based on acousto-optic laser scanning, and solves the problems of low imaging speed, large volume, and large quality which exist in the lidar system based on the traditional mechanical scanning method. Two-dimensional acousto-optic scanning device can achieve fast scanning within a small angular range which makes high-speed 3D imaging possible. This paper analyzed the optical characteristics of target reflection and background, and also analyzed the various influence factors on the measured results. The signal-to-noise ratio expression of the lidar system was deduced. This paper introduced the work mechanism of the two-dimensional acousto-optic scanning device, and described the principle of the system, system components, and the experimental results in detail. From the experiment results, we can know that the imaging speed is 25 fps when the image resolution is 63 × 63, the maximum imaging range of the laser radar is 5 ° × 5 °, the maximum imaging resolution is 240 × 240, for the building target, the maximum operation distance is 850m, the ranging precision is 8.9mm at 30m, and 0.39m at the maximum operation distance. Then, this paper proposed non-scanning difference frequency modulation ICMOS high-speed 3D imaging lidar technology. The lidar modulated the laser intensity and image intensifier gain with two kinds of square wave which were of difference frequency. When the optical echo signal received by the image intensifier, it will generate low-frequency optical signal. Then we use high-speed camera to take sample of this low-frequency optical signal. Through the sampling results, we can calculate the distance information of the target, and achieve 3D imaging. This paper deduced the expression of calculating distance, and analyzed the various influence factors on the measured results. In the paper, the principle of the system, system components, and the experimental results are described in detail, and put forward further improvement methods to improve the system performance. From the experiment results, we can know that the imaging speed is 200 fps when the image resolution is 256 × 256, the imaging range of the lidar is 4 ° × 4 °, the maximum operation distance is 9m, the ranging precision is 1.1m at 6m. If increasing the divergence angle and power of the laser, its maximum imaging resolution can reach 1024 × 1024, the maximum imaging range can be up to 16 °× 16 °. Finally, the paper compared the three kinds of technical methods. The mechanical scanning 3D imaging lidar has the advantages of large working distance ,large working angle range and high precision. But the imaging speed is very slow. Non-mechanical scanning 3D imaging lidar has the advantages of large working distance, high precision and higher imaging speed. But influenced by the device's response time and the scanning angle range, therefore, its imaging range are smaller, and its imaging speed is also required further improve. Non-scanning 3D imaging lidar has the advantages of large imaging range, high resolution and high imaging speed, but at the same time, it needs higher laser power. Its ranging precision is also very low. According to the application requirements, we can choose a more suitable technical solution in practical application
Study on Source Mask Optimization Based on Genetic Algorithm for Lithograhpy
No full text集成电路产业是信息技术产业的核心。光刻机是大规模集成电路制造的关键设备。光刻分辨率决定了集成电路的特征尺寸。为了制造更小特征尺寸的集成电路，业内提出了一系列光刻分辨率增强技术。与传统光刻分辨率增强技术如光学邻近效应校正技术相比，光源掩模优化技术同时优化照明光源和掩模图形，具有更高的优化自由度，是进一步提高光刻分辨率和工艺窗口的关键技术之一。基于遗传算法的光刻机光源掩模优化（Source Mask Optimization based on Genetic Algorithm, GA-SMO）技术不需要掌握光刻成像模型等先验知识，可以使用复杂光刻成像模型和目标函数。此外GA-SMO技术具有全局寻优能力。但是GA-SMO技术模仿自然进化过程进行优化搜索，需要大量光刻仿真计算，导致其优化速度慢，从而限制了该技术的实际应用。针对该问题，本文对GA-SMO技术进行了研究，主要内容包含以下几个方面： 1.提出了一种基于实数编码的GA-SMO技术。使用实数字符串代替二进制字符串描述照明光源和掩模图形，使用实数编码遗传算法的选择、交叉和变异算子代替二进制编码遗传进化算子。仿真实验表明，通过使用实数编码遗传算法提高了GA-SMO的收敛速度。以交错接触孔图形的仿真实验为例，使用实数编码遗传算法后GA-SMO的适应度值收敛到6.0所需的平均代数比二进制编码GA-SMO减少65.5%（约100代）。 2.提出了一种基于多极光源描述方法的GA-SMO技术。多极光源描述方法使用一组圆形子光源描述小光瞳填充比例的自由形式照明光源。相比像素光源描述方法，多极光源描述方法可以用更少的变量描述小光瞳填充比例自由形式照明光源，从而提高遗传算法收敛速度和光刻成像仿真速度。仿真实验表明，在优化成像质量相近的情况下基于多极光源描述方法的GA-SMO技术的优化速度比基于极坐标像素光源描述方法的GA-SMO技术提高7倍。 3.提出了一种基于动态适应度函数的GA-SMO技术。在遗传算法优化过程中采用动态适应度函数模拟实际光刻工艺条件误差对光刻结果的影响，得到对光刻工艺条件误差不敏感的优化照明光源和掩模图形。该技术无需优化权重系数，即可获得与权重优化后的加权适应度函数技术相近的工艺宽容度，减少了优化时间。典型逻辑图形的仿真实验表明，曝光剂量误差为15%时，动态适应度函数技术得到的最优光源和最优掩模的可用焦深达到200nm，与加权适应度函数技术的优化效果相当。动态适应度函数技术也可用于降低最优光源和最优掩模对其它工艺条件误差如彗差的敏感度。 4.提出了一种基于多染色体的GA-SMO技术。使用多染色体遗传算法，实现了像素光源和像素掩模的联合优化。与采用矩形掩模优化的单染色体技术相比，多染色体技术具有更高的优化自由度，获得了更优的光刻成像质量和更快的收敛速度。典型逻辑图形的仿真实验表明，多染色体技术得到的最优光源和最优掩模的适应度值比单染色体技术减少7.6%，多染色体技术仅需132代进化即可得到适应度值为5200的最优解，比单染色体技术减少127代。The integrated circuit industry is the core of the information technology industry. Lithography tool is the key equipment for the very-large-scale integrated circuit fabrication. The resolution of the lithography determines the critical dimension of the integrated circuit. Resolution enhancement technology is used to fabricate integrated circuits with smaller critical dimension. In comparison with traditional resolution enhancement technology such as optical proximity correction, source mask optimization (SMO) technology optimizes the illumination source and mask pattern simultaneously and has larger degree of freedom for optimization. SMO is the key technology to increase the resolution and process window of lithography further. Source mask optimization based on genetic algorithm (GA-SMO) does not require prior knowledge about lithographic process, so it can use more complex lithography model and objective function. In addition, GA-SMO has the capability of global search. However, as GA-SMO imitates the principle of natural evolution to optimize the source and mask, it requires the lithography simulation to be performed many times. This slows down the optimization process and restricts the practical application of GA-SMO. In this dissertation, GA-SMO is studied to improve the convergence speed. The main contents are as follows. 1. A GA-SMO method using real-coded genetic algorithm is proposed. The source and mask solutions are represented by floating point strings instead of bit strings. The selection, crossover, and mutation operators are replaced by corresponding floating-point versions as well. Simulation results show that the convergence speed of the real-coded GA is improved in comparison with the binary-coded version. For example, the simulation result for the staggered contact hole pattern shows that the real-coded method needs about 53.7 generations on average to converge to a solution with the fitness value of 6.0, while the binary-coded method needs about 65.5% (100) more generations to get similar result. 2. A source representation method which increases the speed of GA-SMO is proposed. The proposed representation method uses a group of circular poles to describe the freeform illumination source whose pupil filling ratio (PFR) is small. Compared with conventional pixelated source representation methods, the proposed multi-pole source representation method can represent the low-PFR freeform illumination source with fewer variables. The multi-pole source representation method increases the speed of the GA convergence and the lithography simulation. Simulations are conducted to prove the improvement of GA-SMO speed. On the premise that the simulation conditions are the same and optimization qualities are comparable, GA-SMO using the proposed multi-pole source representation method is about 7 times faster than that using the polar-grid pixelated source representation method. 3. A dynamic GA-SMO method is developed. The dynamic method uses dynamic fitness function in genetic algorithm to simulate the impact of real-world process variations on the lithographic results. In this way, the imaging quality of the optimized source and mask is not sensitive to process variations. The dynamic method can get similar result as the conventional weighting SMO method and does not need to optimize the weighting coefficient. The dynamic method saves the time of weighting factor optimization process and increases the speed of the GA-SMO process. Simulation result shows that the dynamic method can get a usable defocus of 200nm when the dose error is 15%. This result is comparable with the optimization result of the weighting method. The dynamic GA-SMO method can be also used to make the optimal source and mask less sensitive to other process errors, such as coma. 4. A pixelated SMO method based on multi-chromosome genetic algorithm is proposed. The multi-chromosome GA-SMO method uses two chromosomes to optimize the pixelated source and pixelated mask simultaneously. By contrast, the single-chromosome GA-SMO method uses one chromosome to optimize the pixelated source and rectilinear mask. So the multi-chromosome method has larger degree of freedom for optimization than the single-chromosome method. As a result, the multi-chromosome method achieves better imaging quality and faster convergence speed. Simulation results show that the optimal fitness value of multi-chromosome method is 7.6% smaller than that of the single-chromosome method. Besides that, the multi-chromosome method needs only 132 generations to converge to an optimal solution with the fitness value of 5200, while the single-chromosome method needs 259 generations to get similar result
Research on parameter measurement and integrated control in high-power laser system
No full text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。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
Research on the Technology Issue of High Power Laser Amplifier
No full text激光惯性约束核聚变(Inertial Confinement Fusion，ICF)是利用X射线(直接驱动)或者电子(间接驱动)驱动腔靶内的热核燃料，需要激光ICF驱动器在合适波长范围内产生兆焦耳级能量，纳秒脉冲宽度的激光束，从而达到内爆条件。为了激光驱动器更加高效、经济和安全地运行，主要从放大器小信号增益系数入手，研究提高放大器的电光转换效率，减小热恢复时间。泵浦反射腔作为氙灯和钕玻璃之间的耦合器，对小信号增益系数影响较大。因此，本文主要针对放大器的相关工艺问题，研究提高放大器反射腔转换效率的方法，以提升驱动器的工作效率。主要研究内容如下： 1、设计反射腔时，氙灯的发光模型主要包括：(1)氙灯中心点光源；(2)朗伯光源。模型一将氙灯简化为点光源，设计产生成像椭圆反射腔。氙灯和钕玻璃棒分别置于椭圆的两个焦点上，根据椭圆几何特性，能够将大部分氙灯光线传输至钕玻璃棒。模型二认为脉冲放电在氙灯灯管内形成高温等离子体，辐射和吸收两个过程同时存在，放电灯管几乎不透明，大部分辐射实际发生在近管壁的环形区域内。氙灯等离子体的自吸收与电流密度、氙灯直径和氙气气压均有关，因此，氙灯等离子体对自身辐射的不透明度显得尤为重要。为了确定氙灯辐射模型，研究了不同电流密度下，氙灯等离子体对不同波长的自吸收系数；不同氙灯直径下，等离子体的自吸收系数。测试了氙灯表面一点发光区域内任一波长的光谱强度，验证了数值计算的准确性，即氙灯与目标面距离较近时，辐射模型为朗伯光源。 2、已知放大器中氙灯辐射模型为朗伯光源。需要设计最大理论耦合效率下的反射腔结构。采用边缘光线原理和拉线法设计了多灯非成像反射腔，根据系统结构差异，设计了两种计算模型。在相同泵浦能量下，对非成像反射腔和成像椭圆反射腔中钕玻璃棒表面辐照度进行了数值模拟，结果表明：椭圆反射腔中，氙灯辐射光线存在自吸收和互吸收，影响了其增益性能；非成像反射腔避免了氙灯自吸收，且减少了光线反射次数，因此，能够获得最大耦合效率且泵浦均匀。 3、放大器增益均匀性将影响激光光束质量，非成像系统的主要目的是在目标面辐照均匀。因此，采用漫反射理论设计非成像反射腔，针对成像和非成像两种泵浦方式，研究泵浦方式对棒状放大器增益特性的影响规律。设计了成像椭圆反射腔，六边形、十二边形和圆形非成像反射腔，利用几何光学对四种腔结构的能量转换效率进行理论分析计算，数值模拟了钕玻璃棒表面的泵浦光照度，测试了钕玻璃棒横截面任意直径上的小信号增益系数和增益倍数。结果表明：成像椭圆反射腔的小信号增益系数方差最小，增益均匀性最好；非成像泵浦腔结构差异对增益特性影响较大，其中六边形的增益和小信号增益系数最大。漫反射设计理论，没有考虑光线在钕玻璃棒内的传输过程，从而影响了其增益和增益均匀性。 4、基于边缘光线理论设计非成像反射腔，其结构是以氙灯外圆为基圆，通过切线绕氙灯转动形成渐开线反射腔。类渐开线的几何结构能够100%传输氙灯的几何外形，即没有光线反射至氙灯本身。单支氙灯辐照区域固定，相互之间没有影响，避免了因相互吸收光线而导致氙灯负载增加。相比较漫反射理论设计的反射腔，非成像泵浦均匀性高。钕玻璃棒横截面内储能密度的数值模拟和实验结果吻合，相比较成像椭圆反射腔，非成像反射腔小信号增益系数在同等泵浦条件下增大。因此，非成像反射腔能够提高棒状放大器的转换效率。Laser inertial confinement fusion (ICF) relies on either X-ray (indirect drive) or electron (direct drive) to drive the thermonuclear fuel in a chamber. To reach ignition conditions, a laser driver for ICF should have output energy on the order of mega joules at the appropriate wavelength over a few nanoseconds pulse-length. The ultimate goal of research in small-signal gain coefficient is to enhance the electro-optical conversion, and decrease the waste heat, thus develop laser driver as a high efficiency, economic and safe device. The pump reflector as a coupler between the flashlamp and Nd: glass, which greatly affect amplifier’s small-signal gain coefficient. Therefore, according to the related technology issues of amplifiers, we researched on how to enhance the reflector’s transfer efficiency, and then increase the working efficiency of the driver. The main works and achievements are as follows: 1. When we designed the reflector, flashlamp were simplified as a point source or Lambertian source. Basing on the first radiation model of the flashlamp, which formed the imaging ellipse reflector with flashlamp and Nd: glass at the foci. Here, most rays could be transferred to the surface of the Nd: glass through the geometric feature of ellipse. The second radiation model treated the xenon plasma as a grey-body radiator, which could emit as well as absorbed pump light. The radiating xenon plasma was optically thick, meaning that pump light emanated from the surface of the plasma and not from within its bulk. We believed that xenon plasma absorption coefficients change with current density, lamp diameter, and xenon pressure. So, the absorption of emitted radiation by xenon plasma itself was relatively important. In order to determine the model in amplifier, the absolute spectral-intensity measurements at one point on the surface of a lamp tube under different current densities and lamp diameter were tested, and the good agreement between experimental data and numerical simulation demonstrated that if the spacing between the pump source and object is short enough, we can sure that it is a Lambertian source. 2. As we knew that flashlamp was a Lambertian source in an amplifier system. We wanted to design a non-imaging reflector structure with the theoretical maximum coupling efficiency. The multi-lamp non-imaging pump cavities were designed by the edge-ray principle and constant string length method. Two kinds of calculation model were designed by the system structural difference. The Nd: glass surfaces illumination in the non-imaging and elliptical imaging pump cavity were simulated under the same pump energy. The results show that there have lamp self-absorption and mutual-absorption in the elliptical imaging pump cavity, and then affect its gain property, in the non-imaging pump cavity, it avoid the light reflecting back to the lamp and reduce the number of reflections. Thus, the maximum coupling efficiency and pump uniformity are obtained. 3. Laser beam quality sort of being decided by the gain uniformity of amplifier, and the main goal of the non-imaging system was pumping uniformity on the object. Therefore, we designed the non-imaging reflector basing on the theory of diffuse reflection. According to the two pump styles of imaging and non-imaging, the effect rules of the pump style to the rod amplifier gain uniformity was researched. Elliptical imaging pump cavity, non-imaging pump cavities of hexagonal, dodecagonal and circular were designed. Pump energy transfer coefficient of the four kind of cavity structures were analyzed and calculated by geometrical optics. The illumination at the surface of Nd: glass was simulated, small-signal gain coefficient and energy gain at arbitrary diameter of the Nd: glass cross section were tested. The results show that elliptical imaging pump cavity has the minimum variance of small-signal gain coefficient and the best gain uniformity, the structure difference in non-imaging pump cavities have a great effect on the gain properties, and the hexagonal pump cavity has the biggest small-signal gain and gain coefficient. 4. Using the edge-ray principle, the basic shape of the non-imaging cavity was of an involute to the flashlamp’s outer circumference. This profile produced a 100% geometrical transfer efficiency which meant it can reflect all light rays from flashlamp toward Nd: glass, with no light rays travelling back to the flashlamp itself, that would increased amplifier efficiency. Each flashlamp pumped the fixed area on the surface of Nd: glass, either of them had a connect which isolating the load increase, Compared with an imaging cavity, a non-imaging cavity increased the small-signal gain coefficient for the same xenon flashlamp electrical energy and dimensions of the rod amplifier. Numerical results for the stored energy density were compared with measured data and a good agreement was found for the small-signal gain coefficient. Therefore, a non-imaging cavity with several optical features can enhance the pumping efficiency and may increase repetition frequency in the future
Interface of soft X-ray multilayers
No full text软X射线多层膜是极紫外光刻系统中的关键元件，其反射性能与热稳定性对光刻系统的发展有着重要的影响。本文围绕Mo/Si多层膜界面展开讨论，研究了不同条件下多层膜的界面质量，分析了界面扩散与界面化合物形成对多层膜的反射性能与热稳定性的影响。 本文首先将中心波长位于13.5nm处的反射率谱线与硬X射线小角反射谱线结合起来，建立四层模型并提出了多层膜界面精细结构的分析方法。通过TEM、XPS、AFM等辅助分析手段进一步验证了界面分析模型的合理性。基于该方法分析表明磁控溅射制备的Mo/Si多层膜的Mo-on-Si界面宽度比Si-on-Mo大0.2 nm左右，并结合XPS证明界面组成材料是MoSi2。 单层膜工艺调试是多层膜研制的基础，通过研究沉积速率对单层薄膜的沉积过程与组织形态的影响，发现沉积速率的控制是制备致密、光滑薄膜的关键因素。基于稳定的单层膜工艺建立了多层膜沉积速率标定方法，获得了致密、光滑的Mo/Si多层膜的工艺参数，并探索了两种组成材料不同沉积速率组合对Mo/Si多层膜界面结构的影响。结果表明，高的沉积速率会使靶材和基底累积更多的热量，促进了多层膜的界面扩散。但过高的沉积速率会导致界面宽度大，并降低多层膜的反射率与带宽。此外，岛状成核及高能量沉积粒子对成膜表面具有“刻蚀”效应，进而增大界面宽度。 通过在Mo/Si多层膜界面处插入碳（C）扩散阻隔层，研究了扩散阻隔层的厚度对Mo/Si多层膜在13.5nm处反射率的影响。结果表明，扩散阻隔层厚度的增加会降低反射率，同时会影响中心波长的漂移，界面粗糙度先减小后增大。 利用GIXRR测试曲线拟合讨论温度对Mo/Si多层膜周期厚度的影响发现，不添加扩散阻隔层时，Mo/Si多层膜的周期厚度随着温度的上升而减小。当温度达到400℃时，周期厚度急剧下降，当增大到600℃时小角衍射峰消失，表明界面已经模糊。添加扩散阻隔层后，温度从室温上升到400℃过程中周期厚度基本维持稳定。当温度上升到500℃时，周期有微弱的下降趋势，达到600摄氏度后周期厚度减小了0.2nm。结果表明，添加扩散阻隔层后，多层膜的热稳定性有明显的提高，该结论进一步通过XRD与TEM分析得到验证。Soft X-ray multilayers are the critical components for the next generation lithography system, in which the reflectance and thermal stability plays an important role in the further development of extreme ultraviolet lithography system. In this work, we investigate the interface diffusion and interface roughness of the soft x-ray multilayers, which directly influence the optical performance and thermal stability of the EUV mirrors. At first, the extreme ultraviolet reflectance and the x-ray reflectivity data are combined to extract the final interface structure of the Mo/Si multilayers with a four-layer model. Other characterizations such as TEM, XPS, AFM are made to verified the proposed film structure. Based on the model, we find that the Mo-on-Si interface is about 0.2 nm thicker than that of Si-on-Mo interface. The interfacial compound is found to be MoSi2. Since the technique process of single layer is the foundation of multilayer fabrication, the influence of deposited rate on the deposition process and morphology is investigate. The results indicate that the deposited rate is the critical factor to prepare the dense and smooth coatings. Based on the technique process of single layer, the deposited rate of multilayer is investigated and the technique parameters are obtained to prepare the dense and smooth multilayers. The higher deposited rate can widen the interface width and decrease the reflectance and reflective band of the multilayers. The influence of the thickness of diffusion barrier layer on the reflectance of multilayer at 13.5nm is investigated via inserting an interlayer such as carbon. When the thickness of barrier layer increases, the reflectance decreases and the peak location would shift. The interface roughness decrease first and then increase. With the model mentioned above, the influence of annealing temperature on the periodical thickness of multilayer are investigated. The periodical thickness will decrease with the annealing temperature when there is no barrier layer. At 400℃, the periodical thickness decreases rapidly. At 600℃, the peaks in the GIXRR curve disappear, which indicates the roughness of the interface. In contrast, the periodical thickness is rather stable when using carbon as a barrier layer. Only 0.2nm are observed to decrease when at 600℃. The results indicate that the diffusion barriers are beneficial to improve the thermal stability of the soft X-ray multilayer
Study of atmospheric perturbation of satellite-ground coherent laser communication
No full text由于具有高容量、低能耗和高安全性等优势，自由空间相干激光通信近些年越来越受到重视，可以作为传统微波通信的发展和补充，高码率星间相干激光通信也已经获得了巨大成功，欧洲已经开展了自由空间激光通信的商用推广，然而在星地相干激光通信方面一直进展艰难，这主要是来源于大气湍流扰动对相干激光通信系统的影响。 本论文首先介绍了自由空间激光通信的应用背景和技术发展作了介绍，介绍了国内外具有代表性的星地激光通信系统，对系统的组成和原理进行了介绍，然后分析了星地相干通信面临的问题和挑战。对目前流行的DPSK和BPSK相干通信制式的优势和劣势进行了分析，讨论了大气湍流的成因以及其对星地相干激光通信系统产生影响的几个方面，并分别对光强闪烁、光束漂移、到达角起伏、波前畸变等问题提出了解决方案。 针对大气湍流引起的波前畸变问题，研究了自适应光学波前校正的方法。介绍了自适应光学系统的构成和波前重建、校正原理和方法，对自适应光学系统的参数设计进行了介绍。理论分析了不同湍流条件下自适应光学系统的带宽需求，针对二阶控制系统提出了校正带宽不足引起的时延波前误差的计算模型。讨论了低轨卫星和同步卫星对地激光通信链路对自适应光学系统带宽的不同需求。 理论分析了星地相干激光通信中，大气湍流引起的信号光强度和相位起伏。在不同天顶角和不同闪烁强度下，利用Gamma-Gamma数学模型分析了光强闪烁对通信系统误码率的影响，讨论了孔径平均效应在抑制光强闪烁上的作用，提出了无自适应光学系统校正情况下最佳的接收望远镜口径。理论分析了不同D/r0情况下和不同Greenwood频率，自适应光学波前校正对相干通信系统误码率的改善。 利用自行设计的自适应光学系统进行了实验室环境下的波前校正实验，波前校正剩余残差小于七分之一波长并利用相位屏研究了不同Greenwood频率下波前校正残差的变化。在城市环境下搭建了1.2Km激光收发链路，开展了水平大气激光链路的自适应光学校正实验。经过系统校正后，光斑的Strehl Ratio可以从~0.15提高至~0.6，波面剩余残差降低至七分之一波长以下。并研究了不同的自适应光学系统校正带宽对光斑Strehl Ratio的影响。 开展了城市环境下1.2Km和高海拔20Km的水平大气链路相干激光通信实验，研究了实际大气环境对DPSK相干激光通信系统的影响，并对星地相干激光通信接收终端提出优化设计方案。With several advantages, such as much higher date rate, better security and lower energy consumption, free-space laser communication has attracted more and more attentions in recent years. Inter-Satellite coherent laser communication has been verified successfully. It is already planned to extend to commercial areas in Europe. However, Satellite-Ground coherent laser communication is developed difficultly because of the influence of the atmospheric turbulence. First of all, this thesis summarized the development of free-space laser communication technology comprehensively, especially on the typical Satellite-Ground coherent laser communication terminal developed in the world. The composition and the working principle of the Satellite-Ground coherent laser communication system are presented and the challenges this technology faced are introduced. The features of the atmospheric turbulence are discussed and the influences on the coherent laser system are analyzed. In order to deal with the wave-front aberration caused by the turbulence, the adaptive optics (AO) system is investigated. The system composition and working principle is introduced. The method of wave-front reconstruction and correction is studied. Under different turbulence strength and zenith angle, the relationship between the servo bandwidth of AO system and mixing efficiency of coherent laser receiver is simulated and a mathematical model of time-delay phase error for two-order AO control system is proposed. We have also discussed the different servo bandwidth requirement of AO system for LEO-Ground and GEO-Ground coherent laser communication. The fluctuation of signal amplitude and phase caused by the turbulence is analyzed in theory. For different scintillation and zenith angle, the influence of amplitude fluctuation to communication bit-error-rate is simulated by Gamma-Gamma model, the aperture-average-effect on restraining scintillation is also investigated. For the Satellite-Ground receiver without AO, the optimal size of receiving aperture is obtained. Under different D/r0, scintillation and Greenwood frequency, it is proved that the AO system is able to improve the performance of Satellite-Ground coherent laser communication. Under laboratory environment, the RMS of wave-front aberration is able to down to after correction by a self-designed AO system. The fluctuation of residual wave-front aberration increased with the Greenwood frequency. In urban environment， we set up 1.2Km transmit-receive horizontal laser link in order for the experiment of AO correction in real atmosphere. It is shown that the Strehl Ratio can be improved from 0.15 to 0.6. The residual wave-front error can be lower than . We also investigated the influence of servo bandwidth of AO system to the Strehl Ratio after correction. The atmospheric coherent laser communication is performed in urban 1.2Km and high altitude 20Km horizontal laser links. The influence of real atmospheric turbulence to the DPSK receiver is studied and adptive optics system is proved to be effective in compensating the wave-front aberration. Then we give the suggestions on the optimal design to Satellite-Ground coherent laser communication terminal
Maglev Rotating Disk Laser and Passively Q-switched Vector Laser
No full text近年来，随着人们对光的偏振特性研究的深入，一些具有空间非均匀偏振的光束越来越吸引科研人员的关注。在空间非均匀偏振光束的大家族中，最引人注目的是空间各点的偏振态呈圆对称分布的圆柱矢量偏振光束。圆柱矢量偏振光束是矢量亥姆霍兹方程一组本征解，因而也是可以在激光谐振腔中稳定存在的本征模式，可以通过一定的选模方法由激光器直接输出。最近几年，可以直接输出矢量偏振光束的激光器是一个研究热点。径向偏振光束就是一种常见的圆柱矢量偏振光束，其振幅和偏振方向都具有轴对称性而且任意位置处的偏振方向都沿着半径方向。径向偏振光束具有紧聚焦的特性，经过高数值孔径的透镜聚焦后具有更小的焦斑尺寸而且焦点附近会形成一个很强的纵向电场，可以应用于高分辨成像，粒子捕获和电子加速等方面。此外，相较于传统的线偏振光和圆偏振光，有些金属材料对径向偏振光具有更大的吸收系数，因而其在工业加工领域也具有广阔的应用前景。上面提到的很多应用中需要用到高峰值功率、短脉宽的径向偏振激光脉冲，而被动调Q激光技术是一种简单而常用的获得高峰值功率、短脉宽的激光脉冲的方法。本研究利用光子晶体光栅镜作为选模元件，实现了高峰值功率、短脉宽的被动调Q径向偏振激光脉冲输出。 另外，随着激光二极管泵浦源的发展和激光材料制备、加工技术的不断进步，近年来半导体泵浦的全固态激光器发展迅速。虽然激光器能够输出的最高功率一直都在快速增长，但是在空间通信、激光武器、激光雷达和精细加工等领域，对同时具有高亮度的高功率固体激光器的需求也越来越强烈。然而，由于固体激光器的增益介质为固态，在工作的过程中不能流动，增益介质内沉积的热量只能通过介质表面带走，导致高平均功率运转时增益介质内部的温度梯度非常严重。固体激光增益介质内大的温度梯度会使得增益介质内部出现很强的应力，导致热透镜、热致双折射等效应，这就限制了固体激光器输出功率和亮度的进一步提高。如何有效的降低热光畸变，保证高功率运转过程中输出激光的亮度是固体激光器设计过程中的一个关键问题。为了解决这个问题，Basu和Bye提出了转盘激光器的概念。转盘激光器通过电机带着固体激光增益介质盘片转动，可以有效的减少热效应对激光器输出特性的危害，提高激光器输出激光的平均功率和亮度。本研究基于转盘激光器的概念，研究了输出皮秒脉冲的被动调Q的转盘激光器和磁悬浮的光驱动旋转盘片激光器。 本论文主要包括以下内容： 1) 以获得短宽度（纳秒或亚纳秒）、高峰值功率（>15kW量级）的矢量偏振脉冲和皮秒量级的转盘激光器脉冲为目标，进行了被动调Q的Nd:YAG激光器的优化设计。我们首先介绍了被动调Q的速率方程理论和基于速率方程的激光器参数优化设计的步骤。然后，基于这套理论对我们后面要实施的实验方案中相关参数进行了优化设计。 2) 理论研究了连续运转的被动调Q微片激光器增益介质中瞬态温度分布情况，并首次给出了LD端面、连续泵浦的被动调Q微片激光器增益介质中的瞬态温度分布的解析表达式。然后，利用得到的解析表达式分析了增益介质中准稳态温度分布的建立过程，并以常见的Nd:YAG/Cr<sup>4+:YAG和Yb:YAG/Cr<sup>4+:YAG被动调Q微片激光器系统为例分别讨论了激光四能级系统和激光三能级系统中瞬态温度分布情况。通过分析我们发现，在连续泵浦的被动调Q微片激光器的增益介质中，虽然温度分布具有瞬态特性，但是当达到准稳态以后，在激光脉冲发射阶段，增益介质中的温度是不随时间变化的，我们将这个温度定义为平衡温度，并给出了平衡温度的解析表达式。 3) 实验研究了具有<111>切向的YAG/Nd:YAG/Cr<sup>4+:YAG键合晶体的径向偏振被动调Q微片激光器。针对以前的研究中出现的矢量偏振激光光束的光斑不均匀问题，通过分析被动调Q激光器中激光晶体（Nd:YAG）的切向和可饱和吸收晶体（Cr<sup>4+:YAG）的切向对输出光斑均匀性的影响，首次在实验中采用<111>切向的Nd:YAG晶体和Cr<sup>4+:YAG晶体，获得了空间均匀对称的径向偏振激光脉冲输出。实验中输出激光脉冲的峰值功率达到了15.7 kW，脉冲能量达到了50.1 μJ ，脉冲宽度为3.2 ns，重复频率为8.1 kHz。最后，我们还提出了一种新的基于单轴晶体双反射效应的矢量偏振激光器实施方案，并给出了可以实现径向偏振和切向偏振激光输出的具体设计方案。 4) 首次研究并实验研制了输出皮秒脉冲的连续泵浦、被动调Q旋转盘片激光器。我们将转盘激光技术和被动调Q微片激光技术结合在一起，搭建了一台基于Nd:YAG/Cr<sup>4+:YAG键合晶体被动调Q的转盘激光器。首先保持键合晶体盘片不转，当入射的泵浦功率为5.25 W时，激光器输出平均功率为204 mW，脉冲宽度为585 ps，重复频率为7.9 kHz，峰值功率为44.1 kW。随后我们研究了对键合晶体盘片施加转动时，激光器输出脉冲特性的变化。实验发现当电机带动键合晶体盘片以0.5 Hz的频率缓慢转动时，可以消除不转时激光器输出主脉冲后面的尾脉冲，同时激光器输出脉冲的强度波动也会变小，稳定性也有明显的改善。然后继续增大电机转速，在电机转速调节范围内（0~10 Hz），激光器输出脉冲的峰值功率随着转速的加快，一直在升高。当转速达到10 Hz时，激光器输出脉冲的峰值功率比不转时提高了5倍左右。 5) 首次提出并实验实现了磁悬浮的旋转盘片激光器。我们首先介绍了热解石墨片的磁悬浮效应及其在光驱动下的转动特性，然后结合转盘激光器的概念提出了一种磁悬浮的转盘激光器方案。随后以Nd:YAG晶体薄片作为激光增益介质，在实验上初步验证了此方案的可行性。实验中利用LD端面泵浦的结构，在4 Hz转动速率下，实现了17.7 mW的TEM<sub>00单模激光输出，并且通过对比不转的情况，验证了晶体转动对激光器输出光束亮度的提高作用。As one of typical representative of light beams with spatially inhomogeneous polarization, cylindrical vector beams (CVBs) show cylindrical symmetry in both polarization and intensity and are known as the solutions of the full vector electromagnetic wave equation. Among various CVBs, radially polarized light is characterized by axis-symmetrical polarization with the electric field along its radial direction. By applying the high-numerical-aperture lens, radially polarized beam can be focused into a spot beyond the diffraction limit with a strong longitudinal electrical field. Such unique properties enable it to be useful for many areas, such as super resolution, optical trapping, electron acceleration, etc. Moreover, the metal material shows higher absorption efficiency to radially polarized beam than that of others, thus radially polarized beam is beneficial to efficient and high-precision material processing. As CVBs can stably exist as the cavity modes of a resonator, thus they can be directly produced from a laser cavity. Furthermore, many applications require radially polarized laser beam pulse that has high peak power and short duration. As we know, passive Q-switching is a common and simple method for producing short and energetic pulses. One topic of this dissertation focused on the generation of short-duration and energetic radially polarized laser pulse from a passively Q-switched solid-state laser. The second topic of this dissertation concentrated on diode-pumped solid-state lasers (DPSSL) in the rotary mechanism. As known, DPSSL have advantages in compactness and efficiency over other types, and can reach very high powers while maintaining a relatively good beam quality. Until now it has been applied in the various fields including direct-energy weapons, optical lidar and metal processing, etc. However, with the increase of pump power, heat deposition inside the gain medium of DPSSL would degrade the beam brightness and became a main bottleneck for further power scaling. One way to mitigate this heat deposition is to adopt the rotary disk laser geometry, as proposed by Basu and Bye, in which the rotation of the disk quickly removes the deposited heat in the region of laser excitation. Based on this background, we combined the rotating disk laser concept and the passively Q-switched microchip laser technology, and finally obtained picosecond laser pulse with increased pulse stability and peak power. And also we combined the optical control of maglev diamagnetic material and rotary disk laser, and proposed a new laser concept - maglev and rotating disk laser. The main work of this dissertation is as follows: 1.Theoretical model and optimized design to a passively Q-switched Nd: YAG laser were given to obtain nanosecond or subnanosecond vector pulse with >15kW peak power. Firstly, the theoretical model of passively Q-switched Nd:YAG laser was built by applying the rate equations and the optimal parameters of laser resonator was derived numerically. The obtained laser parameters (including length of laser cavity, optimum reflectivity of the output mirror and optimum initial transmission of the saturable absorber) was used as the guidance of subsequent laser experiments. 2.The analytical solutions for the transient temperature distribution in the gain media of continuous wave (CW) end-pumped passively Q-switched microchip lasers were derived for the first time. These analytical solutions of the transient temperature distribution in the gain media were used to evaluate the buildup of quasi-steady-state temperature distribution in the gain media. Then, this theoretical model was applied to analyze the transient temperature of four-level and three-level laser systems (i.e. Nd:YAG∕Cr<sup>4+:YAG and Yb:YAG∕Cr<sup>4+:YAG lasers), respectively. We found that although transient temperature in gain medium remained oscillatory behavior, the transient temperature at the pulsing stage of passively Q-switched microchip laser was a constant, and then we defined this constant as the equilibrium temperature and derived its analytical expression. 3.A radially polarized laser pulse from a passively Q-switched microchip laser with composite structure of <111> cut YAG/Nd:YAG/Cr<sup>4+:YAG crystal was demonstrated. We analyzed the reason of inhomogeneous distribution of light intensity in the existing passively Q-switched vector lasers, and found that both gain Nd:YAG crystal and saturable absorber Cr4+:YAG crystal along the cut direction could affect the uniformity of the output vector beam. In our experiment, by using <111> cut Nd:YAG and Cr<sup>4+:YAG crystals we obtained homogeneously radially polarized laser pulse output. At 6.5 W absorbed pump power, we obtained a radially polarized laser pulse with maximum peak power of 15.7 kW, minimum pulse duration of 3.2 ns, and repetition rate of 8.1 kHz. In the end, we proposed a new vector laser implementing scheme which was based on the bireflectance effect of uniaxial crystal and discussed the concrete design schemes for radially polarized beam and azimuthally polarized beam output, respectively. 4.By combining the rotating disk laser concept and the passively Q-switched microchip laser technology, we experimentally demonstrated, for the first time, a picosecond CW end-pumped passively Q-switched Nd:YAG/Cr<sup>4+:YAG rotary disk laser. In the case of no rotation and 5.25 W incident pump power, the average output power was 204 mW with maximum peak power of 44.1 kW, pulse duration of 585 ps, and repetition rate of 7.9 kHz. Then, we studied the influence of rotating on the characteristics of the output laser pulse, and we found that when compound disk rotaed at a frequency of 0.5 Hz, the tail pulse which existed in stationary mode disappeared, the intensity fluctuation of the output pulse decreased, and the stability was improved obviously. In the motor speed adjustment range (0~10 Hz), the peak power of the output pulse always increased with the speed of the rotating. For example, when the rotating frequency is 10 Hz, the peak power was increased five times higher than that in stationary state. 5.A maglev and rotary disk laser was proposed and demonstrated. By revisiting the levitation of diamagnetic material (pyrolytic graphite, PG) and its light-driven rotation, we combined its optical control and rotary disk laser, and proposed the concept of maglev and rotating disk laser. In the proof-of-concept experiment, a thin disk of Nd:YAG crystal was used as gain medium and attached to a PG plate levitated above a permanent magnets. With this arrangement, we realized a maglev and rotary Nd:YAG laser, and achieved a single-mode output of 17.7 mW at 447 mW of absorbed pumped power and a rotation frequency of ~ 4 Hz. As the detrimental thermal effects were alleviated, the brightness of the output beam was improved
Efficient Vortex Nd:YAG Lasers and Its Intracavity Frequency Doubling Under Annular Pumping
No full text拉盖尔-高斯(Laguerre-Gaussian, LG)光束是一种典型的涡旋光束。在LG光束的振幅表达式中含有一个相位因子项exp(ilθ)（l为拓扑电荷），这说明该光束沿传播方向形成螺旋形的相位波前，因而具有轨道角动量；另外，由于LG光束的中心位置处是一个相位奇点，因而中心的光强为零，使得一般情形下它的光强具有“面包圈”状的环形分布。涡旋光束的这些独特特性使得它在光子捕获和操控、超分辨显微镜、量子通信、引力波探测等众多领域有重要的应用价值。 目前，产生涡旋光的方法主要有被动法和主动法。前者是通过一些转换元件，如柱透镜、螺旋相位板等，在腔外将高斯模式转换为LG模式。但通过被动法得到的涡旋光一般光束质量较差，且转换效率较低、并且不能用于高功率情况。为了获得高功率、高光束质量的涡旋光，一般采用主动法，即直接通过激光谐振腔振荡输出涡旋光束，如：在腔内插入诸如螺旋相位板的光学选模元件；使用特殊的腔镜；利用热透镜效应进行模式选择等。在主动法中，因为具有螺旋相位分布的LG01*模式具有环形的强度分布，所以可使用环形泵浦光端面泵浦激光器，实现激发光与泵浦光模式的空间匹配，从而让激光器直接高效地输出涡旋光束。基于这一选模机理，国内外提出了利用离焦泵浦光、小孔光阑衍射、中空光纤、多模光纤离焦耦合等方式产生环形泵浦光的，并实现了相应的环形光泵浦的激光器。这种基于环形光泵的激光器可减少选模元件的插入，并可以满足高效产生高功率、高光束质量的涡旋光的需求。鉴于环形泵浦激光器具备以上这些特点和优势，本论文的主要任务之一是深入研究基于多模光纤和圆环达曼光栅(Circular Dammann Grating, CDG)泵浦整形的环形泵浦的涡旋光激光器。 与此同时，环形泵浦的激光器所输出的涡旋光的波长受限于增益介质的发射光谱。随着涡旋光束应用领域的不断拓展，如何将其产生的涡旋光的波段拓展至可见光和紫外波段逐渐成为一大研究热点。将经环形泵浦的涡旋光激光器输出的激光波长扩展至短波长的最有效的方法是利用非线性晶体的光学频率转换。迄今为止，已有一些课题组开展了涡旋光束倍频的相关研究，但他们的研究主要集中在腔外倍频，对利用激光器腔内倍频产生短波长涡旋光的报道相对较少。 本研究工作主要立足于以上两点，深入研究了基于多模光纤和圆环达曼光栅泵浦整形的环形泵浦的LG01模的涡旋光激光器，分别实验探索了该涡旋光激光器的腔外倍频和腔内倍频。本论文主要完成了以下几项工作： 1）螺旋相位的干涉检测仿真。分别对不同阶LG光束与参考平面波和参考球面波的干涉图样进行仿真。当涡旋光束与平面波干涉时会出现叉形条纹，与球面波干涉时会出现螺旋形条纹，涡旋光束中不同的拓扑电荷对应不同的分叉数或是螺旋数，且拓扑电荷的正负对应不同的分叉方向或是螺旋旋向，为后续实验中输出激光的相位检测提供基础。 2）圆环达曼光栅整形的环形泵浦的涡旋Nd:YAG激光器。将CDG引入泵浦转换系统，将泵浦光转换为环形泵浦光（转换效率为79.8%，衍射角39.9 mrad）。利用该环形泵浦光端面泵浦Nd:YAG激光器，获得了LG01涡旋激光输出。当吸收泵浦功率为6.38 W时，最大输出功率为1.86 W，斜率效率为34.5%。该激光器具有结构简单、紧凑、成本低、效率高等优点。 为了分析不同透镜组合对环形泵浦光以及激光器输出特性的影响，采用三种透镜组合进行实验，结果表明不同的透镜组合得到的环形泵浦光的光斑直径和宽度不同，而压缩环形泵浦光的光斑直径和环宽有利于降低激光器的阈值泵浦功率，提高激光输出效率，同时改善LG01模的纯度。 3）圆环达曼光栅整形的环形泵浦的涡旋Nd:YAG声光调Q激光器。在基于圆环达曼光栅整形的环形光泵浦的Nd:YAG激光器中，插入声光调Q开关，获得了高光束质量、线偏振、且具有螺旋相位的主动调Q脉冲激光输出。当吸收泵浦功率为5.6 W、声光调制频率为5 kHz时，激光脉冲的平均功率为470 mW，峰值功率为588 W，脉冲宽度为160 ns。 4）多模光纤整形的环形泵浦、线偏振涡旋Nd:YAG激光器。将多模光纤作为模式转换元件，通过离焦耦合将激光二极管的输出光束转换为环形泵浦光，在泵浦耦合系统像方焦平面处获得的环形泵浦光环宽为0.4 mm，光斑半径为250 μm，并且随着泵浦功率的增加一直保持对称、均匀的环形强度分布，具有很好的稳定性。 将该环形泵浦光端面泵浦Nd:YAG激光器，在激光谐振腔中插入Brewster板，获得1064 nm线偏振LG01模输出。当吸收泵浦功率为3.96 W时，最大激光输出功率为548 mW，斜率效率为22.3%，偏振纯度为330:1，输出激光中具有拓扑电荷为1的螺旋相位。 5）多模光纤整形的环形泵浦涡旋Nd:YAG激光器的腔外倍频实验研究。将利用多模光纤离焦耦合产生环形泵浦光的Nd:YAG激光器输出的线偏振涡旋光通过焦距为150 mm的透镜聚焦至a切LBO晶体，温度控制在149°C，实现532 nm倍频涡旋光的输出。当基频光功率为548 mW时，最大倍频光输出功率为0.187 mW，基频光-倍频光的转换效率为0.077%。 6）多模光纤整形的环形泵浦涡旋Nd:YAG激光器的腔内倍频实验研究。为了提高倍频转换效率，采用腔内倍频；为了防止倍频光进入泵浦源，采用折叠腔结构。首先分析了Nd:YAG晶体的热透镜焦距，根据ABCD矩阵进行了腔结构设计，得到相应的腔结构参数。 再在利用多模光纤离焦耦合产生环形泵浦光的Nd:YAG激光器的基础上实现了两种折叠腔结构的腔内倍频。一种是折叠镜与反射镜均为平面镜，非线性晶体采用a切LBO晶体，温度控制在149°C，获得532 nm涡旋光输出。当吸收泵浦功率在4.10~6.69 W的范围内，输出绿光在远场和近场均能保持较对称的环形分布，吸收泵浦功率-倍频光的转换效率为0.4%，x和y方向的M2因子分别为4.02和3.94，实验验证了腔内倍频方案的可行性。第二种是将后腔镜换成曲率半径为200 mm的平凹镜，并在激光晶体与折叠镜之间插入一个焦距为100 mm的透镜，调整LBO晶体的相对位置，实现了绿光的输出，吸收泵浦功率-倍频光的转换效率为0.1%。Laguerre-Gaussian (LG) beams are known as one set of stable solutions of paraxial scalar wave equation in the system of polar coordinates, and its transverse field distribution characterizes by an azimuthal angular dependence of the form exp(ilθ), where l is the topological charge (also the azimuthal index). Such beam has a phase singularity in the center and is called as optical vortices owing to the possessing of an orbital angular momentum. The LG modes, especially the first-order LG (LG01) mode, are becoming attractive for these unique properties, and have found numerous applications in optical tweezers, super-resolution microscopy, quantum cryptography, gravitational waves detection and etc. LG01 mode can be generated by using passive or active methods. The former refers to extra-cavity mode conversion of Gaussian beams through the various optical elements like cylindrical lenses, spiral phase plates, computer-generated holograms and so on. The latter points to the direct oscillation of LG01 mode inside a laser resonator, and usually it can be realized by inserting a mode-selective component into the resonator like spot-defect mirror, diffractive optical elements and etc. Among the various vortex lasers, the annular pumping technique shows unique potential in achieving high power and high beam brightness. This way avoids the adoption of an intra-cavity mode-selective component, and also assures the good spatial overlap between the pumping field and LG01 mode volume in the gain medium. Further, the lasing wavelength of vortex laser described above is limited by the emission spectrum of gain medium. With the increasing demands for vortex beams, it becomes significant to extend the vortex laser sources to visible and ultra-visible (UV) wavelengths. The convenient way to reach this aim is to apply the frequency conversion in these laser sources. Until now, some efforts have been devoted to the second harmonic generation (SHG) of vortex beams. However, most researches focused on extra-cavity SHG of vortex beams, and there have been rather few investigations on intra-cavity frequency doubling of the vortex laser. The dissertation included two parts. In Part I, we focused on Nd:YAG vortex lasers with annular pumping shaped by multimode fiber and circular Dammann grating (CDG), respectively. In Part II, we concentrated on extra-cavity and intra-cavity frequency doubling of vortex laser. More details are as follows: 1）Simulation of interference between LG beams and reference waves. Interference patterns between a LG beam and a reference plane beam or a spherical beam were simulated. A vortex beam interferes with a plane or spherical beam, resulting in the formation of fork or spiral fringes around the singularity. Topological charge can be obtained by the number of forks or spiral petals. 2）Vortex and LG01-mode Nd:YAG laser involving a circular Dammann grating. By introducing a CDG into the pump unit, we demonstrated an end-pumped Nd:YAG laser that emitted vortex and LG01 mode with high laser efficiency and high power. In the scheme, CDG was used to reshape the pumping light into annular profile with diffraction efficiency of 79.8% and diffraction angle of 39.9 mrad, and the adaptation of it was realized easily by inserting it into the pump unit of a conventional end-pumped solid-state laser; the laser cavity was simple, compact and consisted of only a laser crystal and an output coupler. The beam power of this laser reached 1.86 W at an absorbed pump power of 6.38 W with a slope efficiency of 34.5%. 3）Acousto-optically Q-switched and vortex Nd:YAG laser by using circular Dammann grating for annular pumping. By adopting annular-shaped pumping based on CDG, we demonstrated an acousto-optically Q-switched Nd:YAG laser that emitted linearly-polarized LG01-mode vortex output. The averaged power of laser pulse was 470 mW, and the laser pulse showed 588-W peak power, 160-ns duration at 5.6-W absorbed pump power and 5-kHz repetition frequency. 4）Linearly polarized vortex Nd:YAG laser under annular pumping shaped by multimode fiber. By applying annular pumping and intracavity Brewster plate, we realized a linearly polarized Nd:YAG laser. The annular pumping profile was obtained by de-focal coupling the pump radiation into a conventional multimode fiber. The beam power of this laser reached 548 mW at an absorbed pump power of 3.96 W with a slope efficiency of 22.3% and a polarization extinction ratio of 330:1. The measurement showed that the laser beam had helical phase with a topological charge of 1. 5）Extra-cavity frequency doubling of annular-pumped vortex Nd:YAG laser. The vortex Nd:YAG laser described above was linearly polarized. Its 1064-nm output was focused into a temperature-controlled LiB3O5 (LBO) crystal. By adjusting the working temperature of LBO to 149℃, we obtained frequency- doubled laser output at 532 nm. The maximum power of SHG was 0.187 mW when the power of the fundamental laser is 548 mW. 6）Intra-cavity frequency doubling of annular-pumped vortex Nd:YAG laser. Firstly, to realize a vortex Nd:YAG laser that had a folded cavity geometry for the intracavity frequency doubling, we analyzed the thermal effect of Nd:YAG laser crystal and designed the folded cavity by using ABCD matrix method. Secondly, we investigated intra-cavity frequency doubling of a folded Nd:YAG laser that consisted of three plane-plane cavity mirrors. A LBO crystal was used as the intra-cavity frequency-doubling component under non-critical phase matching. We obtained linearly-polarized vortex light at 532 nm. The output maintained annular intensity distributions both in the far- and near- fields when the absorbed pump power was from 4.10 W to 6.69 W with the conversion efficiency of 0.4%. The M2 factors in x and y directions were 4.02 and 3.94, respectively. Finally, we investigated intra-cavity frequency doubling of a folded Nd:YAG laser that consisted of three cavity mirrors (two plane-plane mirrors and a plane-concave mirror with 200-mm radius of curvature). Inside the laser cavity, a lens with 100 mm focal length was placed between the laser crystal and the folding mirror, and also a LBO crystal was used as the intra-cavity frequency-doubling component under non-critical phase matching. By adjusting the LBO’s position, we realized the 532-nm laser output
Research on pulsed fiber lasers at 1.2 μm
No full text1.2μm波段的脉冲激光在激光医疗美容、光谱学、先进成像技术、天文学检测、非线性光学显微镜等领域应用广泛。光纤脉冲激光器相比固体、染料、气体等脉冲激光器具有结构紧凑、耐用性高、设计灵活、光束质量好等优点，更受人们的青睐。因此，1.2μm波段脉冲光纤激光器在科学研究和现实生活中具有良好的发展前景。但是，在1.2μm波段传统的光纤增益介质很少（掺镱离子光纤、掺铋光纤），而且存在的限制比较多，比如效率低、增益竞争严重，因此在该波段得到高效的光纤激光一直是人们研究的热点。近些年来，基于受激拉曼散射原理的拉曼光纤激光器和基于Ho3+掺杂的ZBLAN光纤（增益介质）的光纤激光器在该波段表现出较强进的优势和较高的效率，受到研究者的广泛关注。我们基于这两种增益机制和有效的锁模、调Q脉冲技术，研究了1178nm主动锁模拉曼光纤激光器，1193nm钬掺杂ZBLAN光纤锁模激光器，和1.2μm波长灵活的钬掺杂ZBLAN光纤调Q激光器。论文的主要研究内容包括： 第一章主要介绍了1.2μm波段激光的应用和研究现状以及光纤激光器的发展优势；介绍了1.2μm波段光纤激光器中的多种增益机制；介绍了1.2μm波段脉冲光纤激光器的重要地位及发展前景以及脉冲光纤激光器的调Q和锁模的原理及方法。 第二章主要介绍1178nm主动锁模拉曼光纤激光器的研究，该研究是主动方式锁模的拉曼光纤激光器的首次报道。全保偏光纤组成的光纤环形腔总长约为500m，由1120 nm线偏振的掺Yb3+光纤激光器作为泵浦源，声光调制器作为主动调节机制。通过调节声光调制器的打开时间和调制频率，实现了2 ns宽的1178 nm的稳定锁模脉冲。在更高泵浦功率时，锁模脉冲展宽，观察到2阶拉曼-斯托克斯光的产生，并且通过调节声光调制器的打开时间和调制频率可以有效抑制2阶拉曼-斯托克斯光。对主动锁模脉冲建立过程的研究，证实了拉曼激光器中不存在驰豫振荡过程。另外，通过调节声光调制器的重复频率，实现了392 kHz到31.37 MHz的谐波锁模。 第三章主要介绍1193nm钬掺杂ZBLAN光纤锁模激光器的研究，该光纤激光器是基于钬掺杂ZBLAN光纤在1.2μm波段的首次锁模报道，锁模机制是非线性偏振旋转锁模技术。激光器的泵浦源是1137nm的拉曼光纤激光器。腔内引入Lyot滤波器，它由一段保偏光纤和一个偏振相关的光学隔离器构成，得到脉宽47ps、能量1.3nJ、重复频率1.77MHz的稳定耗散孤子锁模脉冲。在更高泵浦功率下，实现脉冲簇锁模运转，脉冲簇能量高达6.7nJ。 第四章主要包含1.2μm波长灵活的钬掺杂ZBLAN光纤调Q激光器的实验研究。1137nm拉曼光纤激光器作为泵浦源泵浦钬掺杂ZBLAN增益光纤，非线性偏振旋转技术作为可饱和吸收体提供幅度调制。腔内引入Lyot滤波器，调节腔内振荡波长，得到脉宽0.7μs、脉冲能量0.5 μJ的稳定调Q脉冲。另外利用Lyot滤波器周期性的透射特性实现了1190-1196nm波长可调谐和双波长调Q脉冲。Pulse lasers operating in the 1.2 μm region have found a variety of applications in laser medical cosmetology, spectroscopy, advanced imaging technology, astronomy detection, nonlinear optical microscope, etc. Compared with solid, dye, gas and other pulse laser, fiber pulse laser has the advantages of compact structure, high robustness, flexible design, good beam quality, etc. Therefore, 1.2μm pulse fiber laser has a good development prospect in scientific research and real life. But, there are very few kinds of fiber gain medium in 1.2μm. Yb3+-doped and Bi-doped silica fiber with strong gain competitive effect or low emission efficiency cannot up to the requirements of 1.2μm fiber laser. Therefore, researches of high efficiency fiber gain media in this emission band have always been a hot topic. In recent years, Raman fiber laser based on stimulated Raman scattering and fiber laser based on Ho3+-doped ZBLAN fiber have been widely concerned, due to their high efficiency and other advantages in 1.2μm. Using these two gain mechanisms and effective mode locking, Q switching technology, we have realized an active mode-locking of Raman fiber laser at 1178nm; a mode-locked Ho3+-doped ZBLAN fiber laser at 1193 nm; a wavelength-flexible Q-switched Ho3+-doped ZBLAN fiber laser at 1.2 μm. In Chapter I, we mainly introduce the application and research status of 1.2 μm laser and the advantages of fiber laser compared to other kinds of lasers. Multiple fiber gain mechanisms in 1.2 μm are introduced. Important status and developing prospect of the 1.2 μm pulse fiber laser and corresponding mode locking and Q switching technology are introduced. In Chapter II, active mode-locking of Raman fiber laser is experimentally investigated for the first time. An all fiber connected and polarization maintaining loop cavity of ~ 500 m long is pumped by a linearly polarized 1120 nm Yb fiber laser and modulated by an acousto-optic modulator. Stable 2 ns width pulse train at 1178 nm is obtained with modulator opening time of > 50 ns. At higher power, pulses become longer, and second order Raman Stokes could take place, which however can be suppressed by adjusting the open time and modulation frequency. Transient pulse evolution measurement confirms the absence of relaxation oscillation in Raman fiber laser. Tuning of repetition rate from 392 kHz to 31.37 MHz is obtained with harmonic mode locking. In Chapter III, a mode-locked Ho3+-doped ZBLAN fiber laser at 1.2 μm was demonstrated for the first time employing a nonlinear polarization rotation technique for mode-locking. The laser was pumped at 1137 nm by a Raman fiber laser. Stable dissipative soliton mode-locking was achieved with an intra-cavity Lyot filter formed from a length of polarization maintaining fiber and a polarization dependent optical isolator. 1.3-nJ pulses with pulse duration of 47 ps at a repetition rate of 1.77 MHz were produced. Multiple pulse operation with burst energy up to 6.7 nJ was observed at higher pump power. In Chapter IV, wavelength-flexible Q-switched Ho3+-doped ZBLAN fiber laser at 1.2 μm is experimentally investigated. The gain medium is Ho3+-doped ZBLAN fiber, which is pumped by an 1137 nm Raman fiber laser. Nonlinear polarization rotation technique worked as the saturable absorber is adopted in the ring cavity to provide the amplitude modulation. An artifical Loyt filter is inserted into the cavity. Stable Q-Switched pulse trains with the pulse duration 0.7 μs and pulse energy 0.5 μJ are achieved. The periodic transmission spectrum of Lyot filter allows for the laser operating in tunable wavelengths from 1190 to 1196 nm and dual-wavelength Q-switched pulses are observed
Standardization Design in High Power Laser Driver
No full text惯性约束核聚变（Inertial Confinement Fusion，ICF）的研究在开发和利用新能源、解决能源危机问题和国防科技等方面都有着重要的意义。上世纪60年代初，苏联科学家巴索夫和我国科学家王淦昌院士分别提出激光打靶实现核聚变的设想，而高功率固体激光驱动器则是迄今为止国际公认的用于ICF物理研究最成熟的激光驱动器。 高功率激光驱动器是集光学工程、自动控制、精密机械、材料等多门学科于一体的大科学工程。经过半个世纪的发展，激光驱动器的规模不断扩大，光通量逐步提升，器件结构越发复杂，更新换代速度加快。目前，驱动器研制周期的长短、装置的传承与发展问题以及元器件的更换效率等因素都制约了驱动器的快速发展、高效运行。在高功率激光驱动器的工程设计中引入标准化的思想能够有效地解决上述问题。“元件标准化、单元模块化、系统阵列化、装置一体化”的设计能够加快研制进程、降低成本、提高生产效率、提高零部件的互换性、方便安装维护。 本文对高功率激光驱动器的主要零部件进行了标准化方案的研究，主要包括以下工作和成果： 1、分析了高功率激光驱动器的发展及其工程研制中存在的问题，鉴于标准化的基本原理和特点，提出了高功率激光驱动器工程设计中的标准化工作是以元器件的相似性为核心，划分模块为手段。 2、规范了驱动器中零件名称的命名方式和零部件结构标准化的流程，确定了光学元件外径、表面曲率半径、倒角和径厚比的取值要求，介绍了驱动器中的支撑结构、定位结构和调整结构，并比较了不同调整架的性能。设计了一个基于侧向挤压力锁紧连接杆的笼式安装结构。 3、根据片状放大器的结构特征，综合考虑便捷维护和快速更换的需求，提出了组合式片状放大器的标准化方案，将片放划分为五个主要的模块，并提出了每个模块的设计要点和标准化要素。针对片腔内部高洁净度的要求，从洁净设计、加工、清洗、装校和运输方面介绍了片放的洁净控制。基于片状放大器的标准化原则，提出了一种新型的钕玻璃片状放大器玻璃腔的设计方案，优化了片腔的洁净度。 4、阐述了空间滤波器的原理、结构发展和设计要求，主要以主放大级的组合式腔空间滤波器为例，提出了空间滤波器的标准化方案，将其划分为透镜箱、中箱体和真空管道三大模块，并讨论了模块间的连接定位方案。Research into inertial confinement fusion(ICF) has important and practical significance in developing and utilizing new energy, solving the problem of energy crisis and national defense. In the early 1960s, Soviet scientist Basov N and Chinese scientist Ganchang Wang suggested that firing a laser at a target could be a feasible means of achieving nuclear fusion. At present, high-power solid-state laser drivers are internationally adopted for physical research in ICF. High power laser driver is a highly synthetically system engineering, which includes optics, automatic control, fine mechanics, material and the other subjects. The scale of such laser drivers is expanding, their luminous flux has continuously increased, their device structures is becoming more and more complex, and the upgrade of the device is accelerating over half a century of development. At present, short development cycle, heritage and development of past devices, daily maintenance and replacement of the facility are the factors affecting the constructive process and operating efficiency of laser device. Standardization design of engineering is the key role in these factors. The main idea of standardization design is standardized the components, modularized the units, arrayed the system and integrated the facility, which can speed up the development process, reduce cost, enhance productivity, improve the inter-changeability and easy to maintain. This dissertation describes the research work about standardization design in high power laser drive, and the main contents includes as follow: 1. We analyze the development of high power laser driver and the problems existed in the engineering development. Based on the fundamentals and characteristics of standardization, standardization design in high power laser driver is proposed, which is centered on the similarities of assembly units and module division. 2. We propose the naming rules of parts for high power laser driver and the process of standardization design for the parts' structures. The value range of diameter, radius of curvature, chamfering and radius-thickness ratio of optical elements are determined. Structural supports, positioning structures and adjusting mounts for the facility are introduced, and performances of different mounts are compared. A new cage system is designed, which can fix the cage plates and connecting rod by lateral extrusion force. 3. According to the structural features of slab amplifier and the requirements of convenient maintenance and quick replacement, we come up with the standardization scheme of multisegment amplifiers. A amplifier unit is divided into five functional modules, and the standardization design points are given. For the high level of cleanliness requirement in the internal cavity, we introduce the clean design, manufacturing, cleaning, assembling and transport about slab amplifier. Based on the standardization design of slab amplifier, a new glass cavity design for a Nd:glass slab amplifier is proposed in order to optimize the cleanliness of internal cavity. 4. The principle, development and design requirements of spatial filter is shown in this thesis. The standardization scheme of multisegment cavity spatial filter is proposed. A spatial filter is divided into lens boxes, middle box and vacuum piping, and the connection and position fixing methods between different parts are given