Spectral-domain optical coherence tomography (SD-OCT) with a thermal light source

Abstract

Optical coherence tomography (OCT), as a noninvasive imaging technique, has been widely applied in biological and medical fields. The light sources commonly used in OCT are the partially coherent light sources which usual exhibits typically the resolution of 15 to 20 μm. In another approach for an extremely broadband light source is a thermal light source (white light), which may have the potential to supply a compact and low-cost OCT system. In addition, current the majority of OCT measurements are executed in the time domain systems, which are limited in the image acquisition rate and sensitivity. However, a spectral domain optical coherence tomography system (SD-OCT) outperforms the conventional TD-OCT system in imaging acquisition rate and sensitivity. In order to improve both image acquisition rate and axial resolution economically, a white light source spectral-domain optical coherence tomography (SD-OCT) system is constructed, where a tungsten halogen lamp is chosen as the illumination source and a Michelson fiber interferometer is employed to generate interference pattern of object collected by a spectrometer. The object inner structure is obtained from the interference pattern by a Fourier transform. It is theoretically stated and experimentally verified that the white light source SD-OCT system is feasible and enables to realize near real time three dimensional imaging reconstructions of internal structure of engineering and biological materials.