干涉图解相的改进算法及装置
文献类型：学位论文
| 作者 | 朱勇建 |
| 学位类别 | 博士 |
| 答辩日期 | 2006 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 刘立人 |
| 关键词 | 星间激光通信 波面干涉测试 相位提取 相位解包裹 雅敏干涉仪 |
| 其他题名 | Improved phase-extracting algorithms of interferogram and interferometric setup |
| 中文摘要 | 星间激光通信技术由于其自身的诸多优点受到广泛重视，具有广阔的应用前景，而激光通信中光束波面质量在很大程度上影响了通信质量，在其地面模拟和测试中常常采用干涉测试方法，干涉测试方法的精度较高，可测量较小的波像差，而且对波面像差的反映更为直观，因此对干涉测试方法的深入研究非常有必要。一般说来，干涉测试方法的精度主要由两部分构成，一是硬件光路结构，另外一个就是干涉图的计算机处理软件系统。而当前的干涉测试方法发展的趋势是既要提高测试精度，又要使测试结构避免过于复杂化，如何在效率与结构复杂度方面寻找平衡点，许多学者在此方面做了大量的努力。本文主要关注干涉图的计算机软件处理系统，对已有的干涉图相位提取算法和相位解包裹算法进行了深入的研究，提出了改进的准两步相移算法和几种新的相位解包裹算法，为提高激光束波面测量精度和可靠性做了很好的技术储备，同时提出了两种干涉测试装置，并将其一应用于光学晶体的畴结构检测，为今后畴反转的进一步测量打下良好的基础。本论文主要做了以下几个方面的研究： 1.本文首先指出已有两步算法的缺点，提出了相移量为pi的准两步相移策略和可实现任意相移量的两步相移结构装置，与已有的两步和四步相移算法进行比较，结果证明了新算法在提高精度和运行效率方面的可行性，这为以后的相位测量与波面检测提供了新的可行方案。 2.在相移干涉图的处理中首次以调制度梯度的分布特征来评估像素质量，提出了一种新的质量图——调制度—相位梯度偏差质量图，此质量图被证明在标识带严重噪声和不连续区域等缺陷的相位数据时可靠度优于最常用的相位导数偏差质量图，这为提高相位的求解精度和可靠度提供了一种新的方法。 3.研究了单幅包裹相位图的解相技术，提出了两种改进的解包裹算法——基于相位导数偏差质量图的平面拟合算法和基于加权DCT的算法。前者求解结果显示新改进算法在噪声和相位变化较大区域的处理结果优于一般的支切法和掩模分支法。而后者作为一种全局算法在处理局部相位变化剧烈的区域时也显示了其独特的优势——能可靠的反映所有细节部分。这两种算法的提出为非相移干涉图的相位处理提供了简单而可靠的实现方案。 4.提出了背景条纹可调的多功能新型干涉仪，并将其用于晶体畴反转制作的实时检测，对实验图进行数字处理，结果证明实验得到的晶体相位变化值与理论值相吻合。此干涉仪的提出为物体的相位检测提供了一种便利手段。 |
| 英文摘要 | Nowadays, the inter-satellite laser communication technology has received much attention due to its obvious advantages, and holds the broad application prospect. Whereas, the correspondence quality depends on the wavefront of laser beam in very great degree, thus the wavefront testing has become a key problem in the laser communication. Because it can test the small-scope aberration and has high precision and readability, the interferometric method has been widely used in the wavefront testing. General speaking, the precision of interferometric testing is affected by two parts: the optical setup and fringe pattern analysis system. The development tendency of interferometric method is to improve the precision as well as to simplify the testing hardware. How to keep the balance between them becomes the focal problem to which many scholars have devoted their attentions. This dissertation focuses on the fringe analysis system and researches on the phase-extracting algorithm of fringe pattern. Meanwhile, it offers some valuable algorithms about the fringe analysis and lays the favorable foundation for the future wavefront testing, even for the later crystal domain detection. Therefore, the dissertation carries out the following works about fringe analysis. 1.After pointing out the disadvantages of the known two-frame algorithm, we propose a semi-two-frame phase-shifting method with pi shift and compare it with the four-frame algorithm. The results prove that the new method is practical and advantageous in improving the precision and efficiency. At the same time, we also present an improved two-frame phase shifting optical setup which could realize the random-radian phase shift. It provides a new method for the future phase detection and wavefront measurement. 2.For the first time, this dissertation introduces the modulation-gradient variance into the evaluation of phase data and proposes a novel quality map modulation- phase gradient variance map. This new quality map is proved to be robust and reliable, especially in evaluating the phase map with heavy noise and discontinu- ous areas. This also provides a new method for improving the precision and reliability of phase measurements. 3.In processing the only wrapped phase map, this dissertation presents two improved phase unwrapping algorithms—the plane-fitting algorithm based on quality map and weighted DCT algorithm. The former uses the local plane to unwrap the phase under the guidance of quality map. In dealing with the complex phase map, the unwrapped results show the proposal is more robust and reliable than the common traditional method. The later is an improved DCT algorithm which leads to a higher speed than the FFT method. This method keeps its own advantages in unwrapping the wrapped phase with high phase variation and inconsistent areas —could identify the indistinguishable details. This case shows a simple and reliable strategy to handle the phase map. 4.This dissertation provides a multi-functional Jamin-type interferometer, which has been used for the detection of domain structure. By adjusting the tilt and period of fringe pattern, we estimate the phase variation at the domain wall in the ferroelectric crystal by eyeballing. Meanwhile, the results of digital fringe analysis show the computed phase values of domain wall are very close to the theoretic ones. The new-type interferometer offers a convenient means for the real-time detection of phase variation in optical object. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15433]  |
| 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 | 朱勇建. 干涉图解相的改进算法及装置[D]. 中国科学院上海光学精密机械研究所. 2006. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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