Processing-based approach for resolving the sample optic axis in endoscopic polarization-sensitive optical coherence tomography.

Fiber-based polarization-sensitive optical coherence tomography (PS-OCT) that utilizes a rotationally-scanning catheter has a variety of potential biomedical applications in luminal organ systems due to its ability to provide intrinsic contrast for birefringent tissue. Incorporating the optic axis (OA) of the tissue greatly enhances this potential by also permitting information about the orientation of the tissue to be extracted; however, measurement distortion that occurs has up to this point made it impossible to obtain accurate sample OA measurements. In this paper we present a straightforward calibration technique that allows the sample OA to be recovered. This technique requires no hardware modifications making it generally applicable, and as a result has tremendous potential in improving the utility of endoscopic PS-OCT image data.