Optical fiber holographic speckle interferometry

Abstract

Pulsed laser is transmitted by optical fibers, the polarity is changed into random distribution and the coherence is decreased somewhat. But when used in holographic interferometry, optical fibers have substantial advantages, having no influence on formation and clarity of coherent fringes. Two kinds of optical fiber speckle holographic interferometry systems are often used. The first kind employs an optical bundle to form object and reference beams, respectively. The clarity of the formed hologram decreases somewhat, but there is no effect on the contrast and clarity of holographic interferometry fringe. On the basis of the above system, the other makes use of a multimode optical fiber bundle for transmitting the image of an object, and applying lens imaging on the plate. Used in double exposure holographic interferometry the system forms holographic speckle interferometry, the subsequently reconstructed coherent pattern is similar to Young's fringe.