- 學位論文
以軟X 光雷射進行同調繞射影像術之研究
Coherent Diffraction Imaging with Soft X-Ray Laser
摘要
光學顯微術因其非接觸性以及操作便利等特性，在科學發展具有相當重要的地位，我們實驗室過去在使用自製的桌上型軟X 光雷射所發展的數位全像顯微術(Digital HolographicMicroscopy) 已達到480 奈米之解析度，其限制主要來自於所使用之光學元件-凹面鏡之數值孔徑(NA∼ 0.06) 太小所致。 在本篇論文中，我們採用高數值孔徑的光學元件-菲涅耳波帶片(Fresnel zone plate，NA∼0.16)，藉此來提升數位全像顯微鏡的空間解析度。另一方面我們也發展同調繞射影像術(Coherent diffraction imaging)，藉由並合模擬演算法(Hybrid input/output algorithm) 來解決相位問題(phase problem)，並回解出正確的相位及影像來進一步改善影像解析能力。目前，此套軟X 光雷射同調繞影像術之空間解析度約為176 奈米，未來在參數最佳化下，將有潛力具備60 奈米的空間解析能力。
並列摘要
We have developed a digital holographic microscope (DHM) by using tabletop soft X-ray laser at 32.8 nm as the illumination source. In the earlier experiment of DHM, the lateral resolution of 480 nm was achieved in single-shot measurements. The spatial resolution of soft x-ray DHM was mainly limited by the numerical number of concave mirror (NA 0.06). In this thesis, we use a Fresnel zone plate (FZP) which has a larger numerical number NA of 0.16 to improve lateral resolution of DHM. We also develop Coherent diffraction imaging (CDI) by recording large-angle diffraction signals on CCD and retrieving the phase of the signal with hybrid input/output algorithm (HIO). The spatial resolution with FZP achieved by soft x-ray DHM and CDI is 230 nm and 176 nm respectively. In future, we will further optimize the experimental parameters used in our system and push the lateral resolution toward 60 nm.