Common path optical coherence tomographic system suitable for endoscopic imaging

A Fizeau interferometer based optical coherence tomographic (OCT) system using a fiber-based Michelson interferometer to compensate the optical path difference between the reference and sample light in the Fizeau interferometer is presented. The sensing probe of the system is a common path interferometer which can solve the problems existing in current endoscopic OCT systems, such as image distortion due to probe motion, and dispersion and polarization matching which are required when various probes are used. Experiments of path length compensation and vibration are conducted and the results demonstrate that this path length compensation method is feasible and the system can avoid environmental turbulences. Mirror and infrared card are imaged to demonstrate the performance of the proposed OCT system. This imaging approach is thus very suitable for endoscopic imaging, and the detailed method of expanding the OCT system for endoscopic OCT imaging is also presented.