Measurement of structure and strain by transversal ultra-high resolution polarisation-sensitive optical coherence tomography

Optical coherence tomography (OCT) is a technique for contactless and non-destructive imaging of internal structures within semi-transparent materials. When OCT is performed polarisation-sensitively (PS-OCT), additional information about internal anisotropies and strains is obtained. Originally developed for the biomedical sector, OCT increasingly attracts interest for material characterisation. In this work, we apply PS-OCT imaging for non-biological samples using a novel transversal ultra-high resolution PS-OCT set-up. We demonstrate the advantages of this technique for structural analysis and strain mapping for different types of samples: we evaluate photoresist moulds for the fabrication of micro-electromechanical parts (MEMS), and we investigate the glass-fibre composite outer shell of helicopter rotor blades where defects have formed.