1. Principles of OCT

1.1 General principle

OCT was originally conceived as an extension to imaging of the low-coherence interferometry technique used to locate defects in optical fibers [E 7 120] . Using light with a broad spectrum – and therefore low temporal coherence –, only reflections such that the return path is approximately (to within the coherence length) the reference path, can give rise to interference. By modifying the length of the interferometer's reference arm, the...