基于CCD的激光光束质量测量精度分析
文献类型：学位论文
| 作者 | 杨静蕊 |
| 学位类别 | 硕士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 侯霞 |
| 关键词 | 误差分析 光束质量 M<sup>2</sup>因子 CCD 数值模拟 |
| 其他题名 | Precision Analyst of CCD-Based Measurement of Laser Beam Quality |
| 中文摘要 | 本文从介绍激光器的应用开始，综述了目前所用的评价激光光束质量的各种参数，包括远场发散角、聚焦光斑尺寸、斯特列尔比、桶中功率比、衍射极限倍数因子和M2因子，并给出了各个评价参数所适用的范围。接着介绍了光束质量评价参数所涉及到的束宽测量的几种测量方法。M2因子有着区别于其他评价参数的优越性：无像差系统传输不变性，同时包含激光束的近场和远场特性，可作为光学系统设计的参考依据，非常适用于常规激光束特别是商用激光器输出光束的光束质量评价。 为满足空间激光器研制的需要，研制了激光参数测试系统，可对激光束进行M2因子测量。该测试系统使用数字面阵CCD相机作为探测器，激光束的M2因子通过CCD相机对聚焦光束进行扫描和二次曲线拟合得到。为明确该测试系统的M2因子测量误差，从测试系统各元件的参数设置（包括凹球面反射镜的焦距、离轴角和球差，CCD相机的A/D量化精度和像元尺寸），实验条件（CCD入射激光束的光强大小，CCD捕获光斑图像的噪声，光斑采样范围）和图像处理（光斑束宽计算的积分范围，光斑图像去噪方法）各方面对M2因子的测量精度进行了分析。建立数学模型，对测量条件进行了数值模拟，在综合各影响因素的情况下，与实际测量的误差结果相一致。对数学模型中的测量条件进行优化，分析得到M2因子的测量误差不大于1%。 除了可实现M2因子的测量，该激光参数测试测试系统还可对激光束的单脉冲能量、波长、脉冲宽度、重复频率、指向稳定性各参数进行测量，同时能观测激光束的近场特性。其实现方法为，利用入射激光的透射光进行单脉冲能量、波长、脉冲宽度、重复频率的测量，利用光楔将入射激光分为两束，一束用于近场特性观测，一束用于指向稳定性和M2因子的测量。 |
| 英文摘要 | This paper starts by introducing laser applications, then reviews several methods which are commonly used to define and measure laser beam quality such as far-field divergence angle, size of focal spot, Strehl ratio, PIB ( power in the bucket ), times diffraction limit factor and M2 Factor. Application scope of these measurement methods is also provided. Beamwidth measurement is closely related laser beam quality evaluation, so several beamwidth measurement methods are introduced. As a evaluation method of beam quality, M2 factor keeps invariant after passing through any kind of nonaberrated optical system; concludes the beam character both in near-field and far-field; can be used to design and analyze optical systems. So it’s suitable to measure common laser beams, especially those which are output of commercial lasers. A laser performance test system was built to meet the need of development of space laser. The test system can realize M2 factor measurement for laser beam. The test system concludes a M2 factor measurement unit which uses a digital area array CCD camera as detector. The measurement of laser beam M2 factor was realized by CCD scanning and quadratic curve fitting of the focused laser beam. The measurement precision of M2 factor is analyzed. Influencing factors among system parameter-setting (such as focal length, off-axis angle and spherical aberration of the concave mirror, bit-depth and pixel size of the CCD camera), experiment environment (such as light intensity of incident laser beam on CCD camera, noise of laser faculae image captured by CCD camera, sampling range of laser faculae) and image processing (such as integration range when calculating the beamwidth of the laser beam using a laser faculae image, denoising method of laser faculae images) were analyzed to make measurement precision of M2 factor clear. A mathematical model was built to simulate measurement conditions. With all influencing factors included, the numerical simulation analysis result of M2 factor measurement precision turns out to be 9% which agrees with experimental results of measurement precision well. With measurement conditions in the mathematical model optimized, the analysis results turns out to be less than 1%. Besides M2 factor, the test system also can realize measurement of single-pulse energy, wavelength, pulse width, repetition rate, pointing stability and near-field performance observation for laser beam. Transmitted laser beam of incident laser beam was used to realize single-pulse energy, wavelength, pulse width and repetition rate measurement. Reflected laser beam was split into two. One is used to observe near-field performance, the other is used to measure pointing stability and M2 factor. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16670]  |
| 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 | 杨静蕊. 基于CCD的激光光束质量测量精度分析[D]. 中国科学院上海光学精密机械研究所. 2010. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。