We report the first measurement of the direct stress optic coefficient for yttria-partially stabilized zirconia (YTZP) ceramic, using illumination between 260 and 380 GHz with applied stresses up to 27 MPa. YTZP exhibited a linear change in refractive index as a function of stress across the entire applied stress domain. A direct stress optic coefficient was also measured for polytetrafluoroethylene (PTFE). PTFE showed viscoelastic behavior at stress values above 4.5 MPa. These results open the way for quantitative sub-surface stress measurements in structural ceramics and ceramic coating systems at GHz and THz frequencies.
Schemmel, P. J. (Creator), Diederich, G. (Creator) & Moore, A. J. (Creator), Heriot-Watt University, 30 Jul 2015
Schemmel, P., Diederich, G., & Moore, A. J. (2016). Direct stress optic coefficients for YTZP ceramic and PTFE at GHz frequencies. Optics Express, 24(8), 8110-8119. https://doi.org/10.1364/OE.24.008110