Integrated photoelasticity for nondestructive residual stress measurement in glass

The paper gives a review of integrated photoelasticity and of its application for residual stress measurement in glass. By considering the basic theory of the method, two particular cases, the case of weak birefringence and that of constant principal stress axes, are picked up. It is shown that integrated photoelasticity is actually optical tensor field tomography. Its peculiarities in comparison with scalar field tomography are considered. Since directly integrated photoelasticity allows for the measurement of only some of the stress components, analytical or numerical methods are to be used for complete determination of the stress field. Nonlinear optical phenomena, interference blots and fringe bifurcation, are briefly considered. Several examples illustrate the application of the method.