针对远距离无线光通信中光束跟踪受长距离大气传输不确定因素影响大的问题，提出了一种利用双反射镜的无线光系统结构。针对双反射镜到接收端的短轴跟踪控制设计了滤光片转盘模块，通过给反射光斑施加频率扰动的方式来实现对相机探测面上双光斑的辨别，并以探测面上双光斑的重叠情况作为判别光束对准的依据。对于存在偏移的重叠双光斑图像，提出多光斑/重叠光斑中心提取的思路，利用最小二乘法椭圆拟合实现重叠光斑的分割，并对无重叠、较少重叠以及较多重叠三种情况下的光斑图像进行分割实验。研究结果显示，在光斑重叠的场景下，光斑中心定位与实际位置之间的标准差小于0.5 pixel，因此所采用的算法在重叠光斑的分离方面具有很好的效果。

对大型激光装置主放远场自动准直的图像处理进行优化研究，主要包括远场基准计算和远场光斑中心计算两个方面。为了进一步提高图像处理的稳定性和计算效率，在远场基准计算和远场光斑中心计算时对处理图像的区域施加约束。在远场基准计算时，针对transport spatial filter（TSF）图像和cavity spatial filter（CSF）图像，分别采用两个处理流程。在远场光斑中心计算时，对TSF图像和CSF图像，采用统一的处理流程，采用聚类方法计算远场光斑中心。实验结果表明所提图像处理方法具有有效性。

To obtain a good interference fringe contrast and high fidelity, an automated beam iterative alignment is achieved in scanning beam interference lithography (SBIL). To solve the problem of alignment failure caused by a large beam angle (or position) overshoot exceeding the detector range while also speeding up the convergence, a weighted iterative algorithm using a weight parameter that is changed linearly piecewise is proposed. The changes in the beam angle and position deviation during the alignment process based on different iterative algorithms are compared by experiment and simulation. The results show that the proposed iterative algorithm can be used to suppress the beam angle (or position) overshoot, avoiding alignment failure caused by over-ranging. In addition, the convergence speed can be effectively increased. The algorithm proposed can optimize the beam alignment process in SBIL.

为了提升扫描干涉场曝光光束对准精度，保证制作的光栅掩模槽形的质量，建立了曝光光束对准误差模型，利用模型对光束对准误差进行了分析。同时为了满足系统对光束重叠精度的要求，设计研制了光束自动对准系统，并对曝光光束进行了对准实验。分析结果表明，当光束存在较大对准误差时，光栅基底表面曝光对比度大幅下降，而且由于采用步进扫描的曝光方式，光刻胶表面出现了各处曝光不均匀的现象，影响光栅掩模槽形的质量。设计的对准系统可以对光束角度与位置进行对准调节，系统整体表现出良好的收敛性能，多步调节后可使光束位置对准精度优于10 μm，光束角度对准精度优于9 μrad。这样的曝光光束对准精度可以满足系统要求，达到了预期的设计目的。

Laser beam alignment is very important for high-power laser facility. Long laser path and large-aperture lens for alignment are generally used, while the proposed alignment system with a wedge by far-field sampling technique reduces both space and cost requirements. General alignment system for large-aperture laser beam is long in distance and large in volum because of taking near-field sampling technique. With the development of laser fusion facilities, the space for alignment system is limited. A new alignment system for large-aperture laser beam is designed to save space and reduce operating costs. The new alignment for large-aperture laser beam with a wedge is based on far-field sampling technique. The wedge is placed behind the spatial filter to reflect some laser beam as signal light for alignment. Therefore, laser beam diameter in alignment system is small, which can save space for the laser facility. Comparing to general alignment system for large-aperture laser beam, large-aperture lenses for near-field and far-field sampling, long distance laser path are unnecessary for proposed alignment system, which saves cost and space greatly. This alignment system for large-aperture laser beam has been demonstrated well on the Muliti-PW Facility which uses the 7th beam of the SG-Ⅱ Facility as pump source. The experimental results indicate that the average near-field alignment error is less than 1% of reference, and the average far-filed alignment error is less than 5% of spatial filter pinhole diameter, which meet the alignment system requirements for laser beam of Multi-PW Facility.

Laser beam far-field alignment as well as frequency-doubling and frequency-tripling crystal adjustment is very important for high-power laser facility. Separate systems for beam and crystal alignment are generally used while the proposed approach by off-axial grating sampling share common optics for these two functions, reducing both space and cost requirements. This detection system has been demonstrated on the National Laser Facility of Israel. The experimental results indicate that the average far-field alignment error is <5% of the spatial filter pinhole diameter, average autocollimation angle error of crystals is <10 μrad, and average frequency-tripling conversion efficiency is 69.3%, which meet the alignment system requirements on the beam direction and crystals.

光束自动对准技术是扫描干涉场曝光系统中的关键技术之一，两曝光光束位置与角度的重合程度直接影响所制作光栅掩模的槽型质量。针对光束对准过程中光束调整的两个运动维度之间存在相互耦合的情况，推导了存在耦合时对准算法的收敛条件，并分析了光路中反射镜与解耦平面之间存在的装调误差对对准性能的影响。分析得出，装调误差降低了光束对准系统性能，甚至导致对准算法发散，通过调节光路中反射镜M₂和解耦平面的距离L₂与反射镜M₁和解耦平面的距离L₁的比值L₂/L₁可以优化系统的收敛性能。实验结果表明，当L₂/L₁较大时对准系统调节性能较差，收敛速率较低；当L₂/L₁较小时光束对准系统可以快速地收敛到目标位置，有效地对光束进行对准调节。推导证明与模拟分析可为光束对准系统以及整个曝光光路的设计提供理论指导。

Laser beam far-field alignment as well as frequency-doubling and frequency-tripling crystal adjustment is very important for high-power laser facility. Separate systems for beam and crystal alignment are generally used while the proposed approach by off-axial grating sampling share common optics for these two functions, reducing both space and cost requirements. This detection system has been demonstrated on the National Laser Facility of Israel. The experimental results indicate that the average far-field alignment error is <5% of the spatial filter pinhole diameter, average autocollimation angle error of crystals is <10 μrad, and average frequency-tripling conversion efficiency is 69.3%, which meet the alignment system requirements on the beam direction and crystals.

Measurement platform must exhibit a stereoscopic space distribution in diagnostic systems for petawatt lasers to meet the requirement of a periodically poled lithium niobate (PPLN) crystal for light polarization in singlepulse contrast measuring instrument. A mathematical model of a 4D linear matrix is proposed to achieve rapid and accurate beam alignment in picosecond measurement platform. In the petawatt experiments, the alignment algorithm ensures that the near-field and far-field accuracy is less than 0.16 mm and 0.17 mrad, respectively. The motor is adjusted less than three times, and the corresponding elapsed time is in 2 min. The mathematical model meets measurement requirements for alignment accuracy and time. The pulse contrast of the petawatt lasers is obtained from the model. The pulse acquisition probability of the contrast measuring instrument reaches 90% from 10%, to guarantee that the experimental result of pulse contrast can meet the general requirement (more than 106).