廣視野數位全像顯微系統最佳化解析度及其光學檢測應用

Abstract

本論文主要探討如何在廣視野數位全像顯微術達成系統最佳化解析度的目的，利用光學空間帶寬乘積與高空間頻率繞射光與參考點光源傳播方向之干涉角度的分析，設計最佳化參數來提升系統的橫向解析度。一般廣視野的系統會受限於光感測元件，因此使用放大倍率小於1的4f系統，來突破光感測元件視野範圍之限制，但光場經過縮束後會遇到像點解析度與橫向解析度不足的問題，因此以紀錄菲涅爾全像片結合升採樣技術，提升重建平面上的像點解析度，並以空間帶寬乘積，探討其最佳化的記錄距離，使系統能達到較大的視野範圍且橫向解析度接近光學解析度。提升像點解析度與橫向解析度後，可以使原本只能解析 線寬13.92um提升至8.77um，視野範圍可達25mmX25mm。 本研究探討光感測元件的限制以及優化系統解析度，並建立一套玻璃基板的定量化瑕疵檢測之原型機台，具備廣視野單次曝光與即時三維高解析度顯微成像的功能，並可突破影像感測器的像素大小與像素總數的光學偵測限制。最後，設計一五吋光場之廣視野數位全像顯微系統並探討其問題與解決方案，以增加未來光學檢測應用層面的潛力。

We propose a wide-field digital holographic microscopy system to enhance the field of view. In wide-field system, the field of view is limited by image sensor. So we use telescope to enhance the field of view. To resolve the low pixel resolution, we use up-sampling method in Fresnel transform to enhance the pixel resolution in reconstruction plane. Then, to enhance the lateral resolution, we use spherical reference wave to product the additional magnification in spectrum plane. And using space bandwidth product and high spatial frequency with spherical reference wave to analysis the optimized recording distance in WF-DHM, It’s can get the high resolution and keep the wide field of view. After enhancing the pixel resolution and found the optimized recording distance, we can get the lateral resolution from 13.92um becomes to 8.77um and FOV can reach to 25mm X 25mm. Finally. We have established a prototype for glass substrate quantitative defect detection, with a wide field of view and real-time three-dimensional high-resolution imaging capabilities. Finally, design the FOV about five-inch of the wide field system to explore its problems and solutions to increase the potential of optical detection applications in the future.