Optical coherence tomography (OCT) is very promising for high-resolution cross-sectional imaging underneath the surface of biological tissue. The axial resolution of OCT is determined by the coherence length of the light source used in a low-coherence interferometer. In this paper, we demonstrate high-resolution OCT of micro-tissue structures using a femtosecond Ti: sapphire laser. A coherence length of 3.1μm is obtained using a bulk optic interferometer. In the experiment, micro-skin structures including the epidermis, dermis and stratum basale are clearly observed using high-resolution OCT. In vivo high-resolution OCT of human skin was also successfully demonstrated. Furthermore, the thickness of the stratum corneum can be measured as near as 20μm using our OCT system. Our experimental results indicate that a femtosecond laser is suitable for high-resolution OCT for basic research in dermatology.
