Endoscopic hologram interferometry using fiber optics.

Basic and practical problems on the formation of fringes in endoscopic hologram interferometry using fiber optics have been studied in connection with medical diagnosis of living body cavities, nondestructive testing of inner parts of machines, etc. It is pointed out that fiber bundles instead of single fibers can be used to transmit high power laser light for object illumination to prevent the light path break induced by the high power density of concentrated laser light. The effects of extended source illumination by the fiber bundle, image transmission through the ordered fiber bundle, and fiber bundle movement on the fringe visibility were investigated.