Displacement determinations inside three-dimensional transparent bodies by moire, holographic interferometry or speckle methods are based on the registering of the spatial frequencies' alterations of the light scattered in the investigated region of the object after its deformation. The main reason of these alterations is a light diffraction in the investigated section of the object. But there is another reason of these alterations -- the refraction in the whole nonhomogeneously stressed object. The effect of refraction depends of the stress gradient along the light ray and cannot be ignored when this ray cross's the high stress gradient regions. The mathematical model for investigating this effect is considered. This model is used for producing the calculating interferograms of interior sections of transparent objects. Only a phase model approximation is considered. The results obtained by this modeling are compared with the experimental results. It is shown that the effect of refraction may be compared with the diffraction effect and the phase model approximation may be used for their calculation or estimation.

Date Published: 10 June 1996
PDF: 5 pages
Proc. SPIE 2791, Photomechanics '95, (10 June 1996); doi: 10.1117/12.242099

Published in SPIE Proceedings Vol. 2791:
Photomechanics '95
M. Kh. Akhmetzyanov; S. I. Gerasimov; K. L. Komarov, Editor(s)