Development And Application Of Parallel Spectral Domain Optical Coherence Tomography

Optical coherence tomography(OCT)is a non-destructive,non-invasive three-dimensional volumetric imaging technique with high resolution.OCT is used for imaging of the internal microstructure and physiological function of biological tissues,and for industrial non-destructive examination as well.However,issues such as bottleneck of imaging speed and instability due to mechanical scanning still exist in the traditional OCT systems and remain to be resolved.In the thesis,the main part is around the theoretical and application study in parallel spectral domain optical coherence tomography(parallel SD-OCT).The main works included in the thesis are listed as follows:A parallel SD-OCT system is developed based on the theoretical analysis of the key performance parameters,such as axial resolution,lateral resolutions,imaging range,sensitivity and imaging speed.The optical system is optimized aiming to realize a large field of view of 35 mm in the parallel direction with high imaging quality.The developed parallel SD-OCT can perform B-scan imaging at the speed of 108 Hz.The developed wide-field parallel SD-OCT system is applied for inspection of glass.Glass defects can be characterized and measured in the OCT volumetric images.In reflection mode,surface defects can be detected at high speed,while in scattering mode,both surface and internal defects can be detected simultaneously.A novel method with full exploitation of the complex interface signal is proposed for surface topography and interface discrimination,aiming to resolve the issue of discrimination between surface defects and fake defects in the uncontrolled environment.Experiments are conducted,and embedded defects and dust particles with sizes down to 100?m on the prepared glass samples are successfully discriminated.These preliminary results demonstrate the advantage of the proposed method to identify glass surface defects.An approach is developed to remove motion artifacts based on a spatial-spectral encoded parallel OCT(SSE-POCT)system,where encoded rectangular illumination is employed.Motion artifacts within a B-scan are avoided due to parallel detection intrinsic to parallel OCT,while those between successive B-scans are estimated and corrected by a proposed overlapped data correlation(ODC)algorithm.Over-sampling is avoided while enhanced performance over that of the existing correlation algorithm is demonstrated.