MEASUREMENT OF STRESS IN A SYNTHETIC DIAMOND SUBSTRATE USING THE PHOTOELASTIC METHOD

The residual stress in a synthetic diamond substrate was analyzed usin g an automatic data acquisition and analysis system based on photoelas tic principles. Digital image processing techniques were applied to im prove the quality of the sensed images, to reduce noise and to determi ne the boundary of the measured samples. Methods were also introduced to calculate the birefringence phase difference and principal stress d irections. The shearing stress difference method was applied to calcul ate the two-dimensional stress distribution.