Study of full-field optical coherence tomography

Autor: Yao-Sheng Lin, 林耀聖
Rok vydání: 2014
Druh dokumentu: 學位論文 ; thesis
Popis: 102
Optical coherence tomography (OCT) has become one of the most important techniques in biomedical imaging realm. Its axial resolution is determined by central wavelength and bandwidth of the light source. Due to this reason, we made the Ce3+:YAG single-cladding crystal fiber, which generate amplified spontaneous emission centered at 560 nm with bandwidth of 95 nm. And we use it as the light source to demonstrate a full-field OCT with axial resolution of 1.468 μm and lateral resolution of 1.28 μm. In this thesis, we discuss about axial-first and lateral-first image processing method. In the section of lateral-first method, we further discuss the influence on resolution when tuning the range of band-pass filter. Then we give a conclusion that the upper limit of filter should be higher than the maximum spatial frequency sampled by lateral resolution, and the lower limit of filter only need to filter out the DC component. In this condition, both processing methods perform comparable resolution. Therefore, the instantaneity of OCT images could be improved in lateral-first image processing method. We use full-field OCT to scan the single cell specimen and find out that the most suitable reflectivity of reference mirror is about 6%. In order to measure the deeper region of specimen, we design a component to compensate dispersion effect named adjustable dispersion compensator (ADC). We also build a mathematical model to describe the operation of ADC and successfully verify its validity from experimental result. Finally, we demonstrate that the quality of 330-μm-deep single cell OCT image can be improved by the help of ADC and shows the application potential of this homemade component.
Databáze: Networked Digital Library of Theses & Dissertations