High-speed spectral OCT for industrial quality control

The primary goal of the proposed project is the development of a fast scanner based on spectral-domain optical coherence tomography (SD-OCT), as a novel imaging and characterisation tool for industrial applications. Nowadays production industry faces increased challenges in delivering highest quality in short time at competitive prices. In order to satisfy these demands, quality control measures have to be introduced at every stage, from process development over the production process to the evaluation of the final product. Especially, as the dimensions or crucial features of products and parts become smaller reaching down to the micrometer range, the effort - and connected costs - to characterise and evaluate the product`s properties accordingly are increasing dramatically. Preferable, a non-destructive and contact-free inspection and evaluation method has to be found to avoid damage and contamination and to provide fast information with resolutions down to the micrometer range, being at the same time cost-effective and easy to use. Optical Coherence Tomography (OCT) is a novel technology for high-resolution non-contact imaging of semitransparent structures, which has been originally developed for ophthalmology and is currently worldwide intensively pursued for medical diagnostics of diverse biological tissues (skin, internal organs,). Beside the conventional OCT set-up, there exist several instrumental modifications, with SD-OCT being one of the techniques, which exhibit promising potential for high speed and highly sensitive imaging. Surprisingly, applications of SD-OCT in material research, or even for industrial production are up to now not tackled at all, although the fast acquisition speed and the lack of movable parts would render SD-OCT highly advantageous as a monitoring and quality inspection tool in industrial production. Consequently, within this project, the existing knowledge on SD-OCT in the biomedical field will be transferred for the first time to applications in material characterisation and problems posed in industrial production, like the imaging of detrimental crystalline structures in injection moulded polymer parts or the detection of nickel-sulphide precipitates causing spontaneous breakage of glass panes.