Abstract
In this thesis, we designed and studied a broadband light source for time-domain and spectral-domain optical coherence tomography (TD-OCT, SD-OCT). The supercontinuum (SC) was generated by noise-like pulses from an Yb-doped fiber laser in single mode fiber. The central wavelength of the generated SC is 1300 nm and the full width at half maximum can reach 365 nm. The free space and fiber-based OCT were constructed to examine the performance of the new broadband source. For TD-OCT, the experimentally measured point spread function (PSF) indicates an axial resolution of 2.3 μm as compared to a theoretical resolution of 2.1 μm. For free space SD-OCT, the experimentally measured PSF indicates an axial resolution of 2.8 μm as compared to a theoretical resolution of 2.7 μm. For fiber-based SD-OCT, due to the limited optical bandwidth of fiber components of the OCT system, the experimentally measured PSF indicates an axial resolution of 6.4 μm as compared to a theoretical resolution of 5.3 μm and the signal-to-noise ratio can reach 126.7 dB. Using the noise-like SC light source, speckle in the OCT images can be reduced significantly. In the regions of interest, the speckle signal-to-noise ratio (SNR) = 41.32 dB, contrast-to-noise ratio (CNR) = 2.86 dB and equivalent number of looks (ENL) = 3.91. In order to achieve real-time OCT, time-stretching technique was applied to generate the swept light source. Making use of dispersion-shifted fiber, we generated the scanning rate higher than 5 MHz from our noise-like SC light source.