Optical coherence tomography of glass reinforced polymer composites

Abstract Optical coherence tomography (OCT) is a nondestructive and noncontact technique to image microstructure within scattering media. The application of OCT to highly scattering materials such as polymer composites is especially challenging. In this work, OCT is evaluated as a technique to image fiber tows and voids in two materials: an epoxy E-glass-reinforced composite and a vinyl-ester E-glass-reinforced composite. Features detected using OCT are compared with optical microscopy. Fiber architecture and voids of glass-reinforced polymer composites can be successfully imaged using OCT. The quality of the OCT image is strongly affected by the refractive index mismatch between the fibers and reinforcement. The largest sources of noise in the images arise from fiber lens effects, interference from within the sample, and a very large reflection at the surface.