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研究生： 潘淑芳
Phua Soo Fan
論文名稱： A Similarity-Guided Spots Sorting Method to Increase the Dynamic Range of a Shack Hartmann Sensor
指導教授： 梁肇文
Chao-Wen Liang
口試委員:
學位類別： 碩士
Master
系所名稱： 理學院 - 光電科學與工程學系
Department of Optics and Photonics
論文出版年： 2013
畢業學年度： 101
語文別： 英文
論文頁數： 79
中文關鍵詞： 波前量測 、波前重建 、動態範圍
外文關鍵詞： Shack Hartmann, Spots Assignment, Spots Sorting, Quality Guided
相關次數： 點閱：20  下載：0 
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    • 在Shack-Hartmann 波前感應器的資料處理中，正確地把光點分配到各個微透鏡是非常重要的。傳統的分配算法的限制斑點的量轉移到微透鏡的直徑的一半，從而限制了Shack Hartmann感應器的動態範圍。

    這項工作提出了擴展的動態範圍的Shack-Hartmann波前感應器的質量引導演算法。該算法提供了高動態範圍，並且準確度不受局部缺陷及光點遺失的影響。

    該演算法經由模擬的Shack-Hartmann點和實驗獲得的Shack-Hartmann點做測試，並與現有的演算法相比。我們對模擬結果和實際情況的數據進行了分析，並對它們之間的差異進行了討論。

    Assignment of spots to the correct lenslet is critically important to a Shack Hartmann wavefront sensor. Conventional assignment-algorithm limits the amount of spots shift to be half the lenslet diameter, thereby limiting the dynamic range of the sensor.

    This work presents a quality-guided algorithm to extend the dynamic range of a Shack-Hartmann wavefront sensor. The proposed algorithm offers a high dynamic range and excellent robustness.

    The algorithm is tested on both simulated Shack-Hartmann spots and experimentally captured Shack-Hartmann spots.. The performance of the proposed algorithm is compared with existing algorithms. Results from simulation and from real-case data are analyzed. Any discrepancies are discussed.

    Abstract Acknowledgement 摘要 I Abstract II Acknowledgement III Table of Contents IV Table of Figures VI Chapter 1: Introduction 1 1.1 Introduction to Shack Hartmann Wavefront Sensors 1 1.2 Motivation 2 1.3 Objective 3 Chapter 2: Shack Hartmann Wavefront Sensor 4 2.1 Historical Background 4 2.2 Measurement Principles of Shack-Hartmann Sensor 6 2.3 Selection of lenslet array and detector, 9 2.4 Dynamic range Vs. Sensitivity 10 Chapter 3: Literature Review 13 3.1 Software-based Approaches 13 3.1.1 Spiral: Local Similarity 15 3.1.2 Zernike Polynomial Extrapolation 17 3.1.3 Spline Extrapolation 18 3.2 Quality-guided Phase Unwrapping Algorithm 20 Chapter 4: Quality-Guided Algorithm 22 4.1 Priority Buffer 22 4.2 Location Prediction 25 4.2.1 Linear Prediction 26 4.2.2 Nonlinear Prediction 29 4.2.3 Slope Direction 31 Chapter 5: Results 36 5.1 Dynamic Range 37 5.2 Robustness to Missing Spots 45 5.3 Robustness to Local Defect 50 5.4 Computation Time 52 5.5 Experiments 53 5.6 Centroiding 60 5.7 Discussions 62 Chapter 6: Conclusion 64 Chapter 7: Future Work 65 References 66

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