OCT (Optical coherence tomography) is based on?

Optical Coherence Tomography(OCT) is a new imaging modality that produces high resolution, cross-sectional images of ocular structures in vivo. OCT produces detailed two-dimensional images of the retina and measures retinal thickness with a longitudinal image resolution of approximately 10 microns. The principles of OCT are similar to B-mode ultrasound, however OCT utilizes the reflection of Light waves from different structures in the eye rather than sound. Low coherent light, produced by a continuous wave superluminescent diode source, is directed into the eye and is reflected at the boundaries of tissues with different optical propeies. Optical coherence tomography (OCT) is an imaging technique that uses low-coherence light to capture micrometer-resolution, two- and three-dimensional images from within optical scattering media (e.g., biological tissue). It is used for medical imaging and industrial nondestructive testing (NDT). ref khurana 6th edition pg 456