Polarization-sensitive optical coherence tomography for photoelasticity testing of glass/epoxy composites.

We measure the spatial distribution of the mechanical stress induced inside translucent glass/epoxy composites by means of polarizationsensitive optical coherence tomography. The Stokes parameters determined from two orthogonal polarization components of the backscattered light allow the internal stress to be identified in terms of its magnitude and principal direction based on a birefringence light scattering model of glass/epoxy composites. Measurement examples show the particular case of stress concentration near a through hole and the internal structural damages caused by excessive tensile loading.