Full-field optical coherence tomography—An educational setup for an undergraduate lab

Optical coherence tomography, or in short OCT, is a measurement technique established in the early 1990s for the non-invasive imaging of interfaces in the bulk of biological tissues or other samples. A full-field OCT setup is built from a microscope combined with a Michelson interferometer, where the mirror in one arm is replaced by the sample. Using white light, which is temporally partially coherent, interference fringes disclose the presence of an interface whenever the lengths of both interferometer arms are nearly equal. Scanning one arm allows for a volumetric reconstruction of all interfaces inside the sample. While the importance of OCT in medicine is indisputable, it is hard to teach students the basic aspects of such technology as most available setups tend to be rather complex. It is our purpose to present a fully functional full-field OCT setup that is stripped-down to its essential components and to promote its use in an undergraduate lab course. The contribution is complemented by a description of the basic theory necessary to understand the working principle of OCT.