Nondestructive material testing using OCT

Abstract

The fact that optical coherence tomography (OCT) provides information on internal structures of scattering tissue in a noninvasive way has led to a broad acceptance of OCT for dedicated biomedical imaging and diagnostics applications. Outside the biomedical field, an irreversible alteration of an object under investigation by the characterization method itself is likewise undesirable, especially in the case that such an object has to be further used with its original state maintained. For this purpose, a variety of so-called nondestructive testing (NDT) methods is nowadays at hand, with OCT as novel technique exhibiting a huge potential to add valuable contributions to nondestructive testing and evaluation of semitransparent, scattering materials with structural features on the micron scale. Therefore, within this chapter, a broad range of applications for OCT in NDT is presented, ranging from examples of industrial quality control over classification and authentication tasks to the evaluation of materials in research and development.The individual applications are listed according to the category of information obtained from the individual measurements, starting with the evaluation of the pure surface structure, proceeding to thickness measurements of layered systems, to imaging of internal 3D structures and finally leading to the determination of functional information.