Tensile Stress Measurements with Photoelastic Scattering at THz Frequencies

Photoelastic scattering in silicon wafers is observed at THz frequencies. Tensile stress has been applied to silicon wafers at different crystal orientations and 2D stress mapping is conducted. A large dependence of the photoelastic effect on the crystal orientation is observed with a ten times larger effect for the {100} axis over the {110} axis.