Application of real time interferometry to NDT of the most vital parts of mechanical constructions in machinery is one of the challenging problems of contemporary engineering. The basic principle of interferometric methods is based on non-contact sensing of displacements which leads to visualization of defects, visualization of vibrated modes and stresses. In real engineering constructions almost all monitored objects have diffusely reflective surfaces, which are non mirror-like. Unfortunately a small interference contrast of diffusely reflective surfaces using contemporary interferometric technique inhibits applications of these methods to NDT. The most contemporary potentially powered method of electronic holography EH produced low contrast interferogram of diffusely reflective objects (Fig.1). It needs special algorithms, software, and time processing to improve the contrast of interference fringes. The real time monitoring, which based on surface displacements measurements under high energy impact such as laser shout, ballistic problems in military, etc. needs high contrast, real time metrology. The interferometric technique of highly effective dynamical grating has been proposed in continuous hologram development regime for monitoring of diffusely reflective objects in the real time.

Date Published: 20 September 2007
PDF: 11 pages
Proc. SPIE 6695, Optics and Photonics for Information Processing, 66950X (20 September 2007); doi: 10.1117/12.733217

Published in SPIE Proceedings Vol. 6695:
Optics and Photonics for Information Processing
Abdul A.S. Awwal; Khan M. Iftekharuddin; Bahram Javidi, Editor(s)