激光成像跟踪系统是实现空间远距离暗目标跟踪的一种极具潜力的手段, 而目标在激光照射下的 图像将受到激光散斑的调制作用,影响目标的识别及目标的定向精度。对激光照射下目标图像的 统计特性进行了理论分析,提出了一种对原始图像依次实施灰度线性变换、中值滤波和Lee滤波的组合 数值滤波器对图像噪声进行抑制。处理的结果表明,采用上述组合方法,图像的噪声指数可从0.67降至0.22, 同时边缘保持度可达0.96,为后续的图像处理提供了必要的基础。

激光成像跟踪系统是实现空间远距离暗目标跟踪的一种极具潜力的手段，而目标在激光照射下的图像将受到激光散斑的调制作用，影响目标的识别及目标的定向精度。对激光照射下的目标图像的统计特性进行了理论分析，提出了一种对原始图像依次实施灰度线性变换、中值滤波和Lee滤波的组合数值滤波器对图像噪声进行抑制。处理的结果表明，采用上述组合方法，图像的噪声指数可从0.67降至0.22，同时边缘保持度可达0.96，为后续的图像处理提供了必要的条件。

在充分考虑了空间背景光辐射特性以及漫反射目标对相干光和自然光的不同反射特性的基础上,利用信号检测的统计学方法,导出了空间电荷耦合器件(CCD)凝视成像跟踪系统分别在激光照明主动跟踪模式和太阳光照明被动跟踪模式下的作用距离表达式。结果表明,空间CCD凝视成像跟踪系统在脉冲能量为1 mJ的激光照明主动跟踪模式下可对1 m2空间漫反射目标实现10 km量级范围内的跟踪;而利用太阳光照明的被动跟踪模式下的跟踪距离可达几百千米。

为了利用激光雷达对空间碎片进行探测，根据空间环境和空间碎片的特性，给出了空间中的激光雷达作用距离的具体表现形式，并详细分析了空间的背景辐射并给出了处理后的结果，从而推导出最小可探测光功率的计算公式，进而给出了系统所需最小发射光功率和探测系统的信噪比。结果表明，利用激光雷达可以对几十千米范围内的较大空间碎片进行探测。

报道了半导体抽运的Nd:YAG叠片热容激光器的理论与实验研究,并用热容激光器的理论模型计算了在一定的工作时间和介质温升内激光输出特性,用Zemax软件对其抽运结构进行了模拟计算.实验中采用的4片Nd:YAG晶体尺寸均为63.5 mm×38.5 mm×7 mm,抽运平均功率约110 W,重复频率为10 Hz,占空比为0.2%,获得了最大19.1 W的1 064 nm激光输出,光光效率约17.4%.最后对两种抽运结构的叠片激光器进行了比较,提出了下一步的改进方案.

Space debris distribute in a large range in the space, and their size are very different. For the purpose of detecting the small space debris, the space-based laser radar is used. The characteristics of the background radiation in space are analyzed at first. Then, according to the analog and digital detection theory of laser radar, with avalanched photodiode as the detector, the minimal detectable laser powers are calculated. Based on the radar equation, the detection ability of laser radar is got. The result indicates that the space-based laser radar is effective to detect the small space debris in a specific range.

A laser diode (LD) stack pumped solid-state laser (DPL) with different cooling conditions was reported. The thermal lens was calculated and compared under different cooling conditions. The influence of the thermal lens effect on the output energy fluctuation of the DPL was studied. The LD stacks peak power was 12 kW with 1-kHz repetition frequency and 20% duty ratio. In the examination with nothing to cool the solid-state heat capacity laser (SSHCL), the output power was 1 J at the beginning, after 1 s it fell down to 50%, and with the water cooling the output power hardly fell down.

A new method is proposed which makes it possible to produce flattened irradiance distribution by incoherent combination of cosh Gaussian beams with different parameters. Based on the Collins integral formula, the resulting irradiance distribution is derived and the corresponding beam qualities in terms of M2 factor and kurtosis parameter are given. The numerical examples illustrate that a flattened intensity distribution of the resulting beam can be obtained in the near filed if appropriate parameters are chosen. Compared with the coherent combination of the Hermite-Gaussian (HG) beams, this new method leads to better beam quality and can be more easily realized experimentally resulting from in-phase-free requirement.

研究了基于干涉测量激光介质热畸变的原理,利用CCD摄像机记录干涉条纹并通过计算机图像处理,来测量板条激光介质动态热畸变的方法。对采集得到的干涉条纹进行图像处理,提出了一种简单快速提取条纹中心的算法。通过分析、计算干涉条纹的移动,得到抽运过程中板条激光介质的动态热畸变情况,为动态补偿激光介质热效应提供了可能。实验采用了N31磷酸盐激光玻璃作样品,得到了加热过程中激光玻璃内部的温度分布,误差约为3%,验证了该测量方法的可行性。

提出一种新型光束质量实时测量技术, 该技术主要基于由平板反射镜组成的多平面成像系统, 一次性将激光束腰附近2倍瑞利距离内的多个光斑成像在同一个平面上, 用CCD相机获取这些光斑的光强分布图样。通过图像处理获知接收到的光斑的光强分布。采用远场发散角、焦点尺寸、桶中功率比和M2因子四种光束质量评价标准对激光光束质量进行评价。利用该方法实时测量了高能钕玻璃双板条激光器的输出光束。