Fundamental imaging properties of transillumination laser CT using optical fiber applicable to bio-medical sensing

We proposed and developed a novel transillumination laser CT imaging system using optical fiber based on an optical heterodyne detection method for biomedical use. The features of the imaging system are portability and robustness against environmental changes such as variable room temperature and unexpected vibrations. In addition, a motion-artifact-free image can be obtained because the measurements can be performed with the object fixed. In this paper, we experimentally investigate the fundamental imaging properties of the system in detail, which has spatial resolution of 500 μm, dynamic range of more than 100 dB, and minimum detectable power of 10^-14 W. Based on the facts, the system reconstructs tomographic images in a way similar to X-ray CT. Finally, we confirm the feasibility of fiber-optic-based laser CT by demonstrating the first tomographic image of a physical phantom.