Based on low‐coherence interferometry, a hybrid optical coherence tomography (OCT) system has been built. It coupled time‐domain OCT (TD‐OCT) and Fourier‐domain OCT (FD‐OCT) into one system. TD‐OCT can take the advantage of a large axial scan range while FD‐OCT has superior performance in fast imaging as no axial scan is needed. The two imaging modalities shared a broad bandwidth light source with a centre wavelength of 1550 nm, which is less scattering and can give better penetration depth in the polymer‐based material than the shorter wavelength used for biomedical applications. 2D translation stages were incorporated in the system to make cross‐sectional and volume imaging available. It can provide larger scan range as well as less image distortion compared with galvo scanners. Finally, we reported on successfully characterized specimens such as polymer coatings and glass‐fibre composites. The cross‐sectional and volumetric images obtained clearly show the microstructure of the materials. The thickness as well as the defects, e.g. microcrack and delamination can be determined.

Modulated surface-textured substrates exhibiting high haze in a broad range of wavelengths were fabricated. Glass substrates coated with different thicknesses of a sacrificial layer were wet-etched allowing the manipulation of the surface morphology with surface roughness ranging from 200 nm up to 1000 nm. Subsequently, zinc-oxide layers were sputtered and then wet-etched constituting the final modulated textures. The morphological analysis of the substrates demonstrated the modulation of surface morphology. The optical analysis revealed high haze parameters and broad angle intensity distributions, which is explained in terms of superposition of different scattering mechanisms. A small anti-reflective effect with respect to untreated glass was found for the etched glass samples. Amorphous silicon solar cells on high-haze substrates were fabricated and their performance was evaluated. The solar cells outperformed the reference cell fabricated on a randomly-textured zinc-oxide-coated flat glass. The trend in the efficiency resembled the increased surface roughness and the anti-reflective effect was confirmed also in solar cell devices.

Optical coherence tomography (OCT) is a contactless and non-destructive testing (NDT) technique based on lowcoherence interferometry. It has recently become a popular NDT-tool for evaluating cultural heritage. In this study, protective coatings on wood and their penetration into the wood structure were measured with a customized infrared fiber optic OCT instrument. In order to enhance the understanding of the OCT measurements of coatings on real wooden samples, an optimization of the measuring and analyzing methodology was performed by developing an averaging approach and by post-processing the data. The collected information was complemented by data obtained with hyperspectral imaging to allow data from local OCT A-scans to be used in mapping the coating thicknesses over larger areas.

Modulated surface-textured substrates for thin-film silicon solar cells exhibiting high haze in a broad range of wavelengths were fabricated. Glass substrates coated with different thicknesses of a sacrificial layer were wet-etched allowing the manipulation of the surface morphology with surface roughness ranging from 200 nm up to 1000 nm. Subsequently, zinc-oxide layers were sputtered and then wet-etched constituting the final modulated textures. The morphological analysis of the substrates demonstrated the surface modulation, and the optical analysis revealed broad angle intensity distributions and high hazes. A small anti-reflective effect with respect to untreated glass was found for etched glass samples. The performance of solar cells on high-haze substrates was evaluated. The solar cells outperformed the reference cell fabricated on a randomly-textured zinc-oxide-coated flat glass. The trend in the efficiency resembled the increased surface roughness and the anti-reflective effect was confirmed also in solar cell devices.

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