Endoscopic hologram interferometry using fiber optics

Factors are investigated regarding the fringe visibility reduction in the endoscopic hologram interferometry system. The use of a fiber bundle, instead of a single fiber for object illumination transmission to reduce power density and a possible break in light transmission, is proposed, and the ordered fiber bundle as an image transmitter considered. Schematic representations and detailed descriptions of the optical configurations, measuring effects of source size and aperture size are given. The experimental configuration investigating the effects of image transmission in the fiber bundle on the fringe visibility is presented in detail. The data indicate that the power density of a high power pulsed laser can be decreased and a break in the light path prevented by reducing the aperture size and leaving the source size larger. Furthermore, by varying the fiber bundle translation, double exposed holograms were recorded and the fringes could be observed up to a fiber bundle translation of 300 microns. It is included that if this value is defined as the allowable movement of fiber bundles, most objects in living bodies, and in moving environments can be inspected by endoscopic hologram interferometry using fiber optics.