This book presents the state-of-the-art information regarding optical coherence tomography. Optical coherence tomography (OCT) is an imaging technique providing high-resolution cross-sectional images in several fields of engineering and medicine. OCT images are created by measuring the intensity of reflected or back scattered light which is scanned across the tissue and material. The aim of this book is to present elaborative information on OCT in a wide spectrum of fields including oncology, engineering, ophthalmology and atherosclerosis.