Optimazation On Imaging System And Characterics Of Frequency Domain Optical Coherence Tomography

Optical Coherence Tomography is a noninvasive three-dimensional imaging technique, with the advantages of high resolution, high imaging depth compare with other optical imaging technique, so this technique have extensive application prospect in biomedicine, optical detection and many other fields. Fourier-domain Optical Coherence Tomography(FD-OCT) is one kind of Optical Coherence Tomography, which is based on Michelson interferometer and the spectrometer. It get the tomographic structure with additional axial scan which is different from Time-domain Optical Coherence Tomography(TD-OCT), so that short imaging time, high sensitivity and many advantages is achieved in FD-OCT system compared with conventional TD-OCT.In this thesis,the influence factors of imaging quality of spectrum domain optical coherence tomography are investigated in experiment. With a super-radiation laser diode of wavelength 840 nm as a light source, the experimental setup of a spectrum domain OCT system using optical fibers is constructed. The automatic measurement and control software for the OCT experiment based on LabVIEW language is written, and essentially realize the real-time recording, tomographic reconstruction and display. The influence factors on tomographic imaging are preliminary studied. The tomographic reconstruction algorithm is programed, including homogeneous wave number resampling algorithm, phase-shift algorithm for removal of conjugate image, and dispersion compensation algorithm. Further combining with B-scan, tomographic imaging for a target sample of five-layer cover slips in different depth regions is performed by using shift-multiplexing complex spectral domain optical coherence tomography(CSD-OCT).The tomographic images are also influenced with the sample's structure and refractive index distribution that even can cause the sample structure beyond recognition in tomographic images. The distortion of tomographic images is analyzed via its definition and classification. The measurement of refractive index of the cover slips is achieved based on the correction of distortion of tomographic image.