合成孔徑數位全像顯微術最佳化超解析及其共光程螺旋相位濾波之研究
No Thumbnail Available
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
本論文主要探討如何在數位全像顯微術中達成系統最佳化解析度的目的，並設法以共光程技術來簡化光學實驗架構與提升系統穩定度。研究中以反射式數位全像顯微術為基礎，利用記錄菲涅爾全像片的方法並搭配升採樣技術增加像素解析度，再以合成孔徑技術提升系統空間解析度，即完成最佳化解析度之系統設計。在最佳化解析度的實驗架構下我們成功地以可見光波段雷射光源量測出線寬約160 nm的線對物體，並達到相位精準度約6 nm。另外在共光程架構中，我們透過空間光調制器產生螺旋相位濾波器，並放置於成像系統中的傅立葉平面，如此可使單一光束分離為參考光波與物體光波，而得以記錄下數位全像片。接著由數值運算方法即可定量計算出物體之複數振幅資訊。在此共光程的架構下，物體光與參考光之間的干涉效果不易受外界環境影響，如此即有效地增加系統穩定度且簡化了光學實驗架構。最終將共光程螺旋數位全像顯微術與合成孔徑技術結合後，以波長為650 nm雷射為實驗光源的條件下達到約280 nm的橫向解析度與4 nm的相位精準度。
This works mainly discusses how to optimize the system resolution in the digital holographic microscopy (DHM). We also try to enhance the system stability and simplify the experimental architecture by applying common-path setup. This research bases on reflection type DHM. The pixel resolution is improved by recording Fresnel hologram and up-sampling method. Then, the synthetic aperture (SA) technique is employed to enhance the spatial resolution in DHM system. In the experiments, the SA up-sampling technique gives better image resolution up to about 160 nm with phase accuracy about 6 nm by using visible light source. In addition, we produce a spiral phase filter by spatial light modulator (SLM) and place in the Fourier plane of common-path imaging system. The digital hologram can be recorded by separated the probe beam into object beam and reference beam. The quantitative complex amplitude information of object can thus be obtained by numerical reconstruction. In this common-path system, the stable architecture of interference system can avoid the influence from the external environment. So, it effectively increases system stability and simplifies the optical experimental setup. Finally, combing common-path spiral DHM and SA technique with 650 nm laser light source, the lateral resolution achieves about 280 nm with phase accuracy about 4 nm.
This works mainly discusses how to optimize the system resolution in the digital holographic microscopy (DHM). We also try to enhance the system stability and simplify the experimental architecture by applying common-path setup. This research bases on reflection type DHM. The pixel resolution is improved by recording Fresnel hologram and up-sampling method. Then, the synthetic aperture (SA) technique is employed to enhance the spatial resolution in DHM system. In the experiments, the SA up-sampling technique gives better image resolution up to about 160 nm with phase accuracy about 6 nm by using visible light source. In addition, we produce a spiral phase filter by spatial light modulator (SLM) and place in the Fourier plane of common-path imaging system. The digital hologram can be recorded by separated the probe beam into object beam and reference beam. The quantitative complex amplitude information of object can thus be obtained by numerical reconstruction. In this common-path system, the stable architecture of interference system can avoid the influence from the external environment. So, it effectively increases system stability and simplifies the optical experimental setup. Finally, combing common-path spiral DHM and SA technique with 650 nm laser light source, the lateral resolution achieves about 280 nm with phase accuracy about 4 nm.
Description
Keywords
數位全像顯微術, 合成孔徑, 升採樣, 解析度, 螺旋相襯顯微術, 共光程, digital holographic microscopy, synthetic aperture, up-sampling, resolution, spiral phase contrast microscopy, common-path