Optical coherence tomography (OCT) is an emerging imaging modality, which is the optical analog of ultrasound. OCT can perform high resolution, cross sectional and volumetric imaging of the internal structure of biological tissues and materials. OCT is promising for biomedical research because it enables tissue pathology to be imaged in situ and in real time. Dramatic advances in imaging resolution and speed have been achieved using spectral domain OCT (SD-OCT) and swept source OCT (SS-OCT). Functional extensions such as OCT angiography (OCTA) enable three dimensional microvasculature to be imaged using motion contrast from flowing blood cells. OCT technology also has numerous applications in fields spanning clinical medicine, fundamental research and nondestructive evaluation of materials. This course describes OCT principles including interferometry, Fourier domain detection, spectral domain and swept source OCT, and OCT angiography. The course also discussed translation to clinical medicine using example applications.