Optical Coherence Tomography

13.1 Introduction

Over the last decade, non-invasive or minimally invasive spectroscopy and imaging have been witnessed widespread and exciting applications in biomedical diagnostics. Optical techniques that use the intrinsic optical properties of biological tissues, such as light scattering, absorption, polarization and fluorescence, have many advantages over the conventional x-ray computed tomography, MRI and ultrasound imaging in terms of safety, costs, contrast and resolution features. Time-resolved and phase-resolved optical techniques are capable of deep-imaging of the tissues that could provide information of tissue oxygenation states and detect brain and breast tumors [1,2], whereas confocal microscopy and multi-photon excitation imaging have been used to show cellular and sub-cellular details of superficial living tissues [3,4]. However, most biological tissues strongly scatter the probing light within the visible and near infrared range, i.e.,