Optical coherence tomography for characterization of nanocomposite materials
Nanocomposite materials play an increasingly important role in various application areas, be it in an industrial, medical or everyday environment. The unique properties of nanocomposites go beyond those of conventional composite materials. Because nanoparticles have a high surface-to-volume ratio such as carbon nanotubes, they can reinforce an embedding polymer host matrix mechanically, or they enhance the electrical material conductivity. A major challenge in the development of nanoparticles
... d nanocomposites is the control of particle size and shape, and of the uniform dispersion of nanoparticles in the host material. Conventional characterization techniques lack either resolution, or can only inspect details of small samples. In this book, the application of optical coherence tomography (OCT) for nanocomposite and nanoparticle characterization is investigated. OCT is a threedimensional imaging method with microscopic resolution. We follow a multiscale approach: Along with imaging in the micrometre to millimetre regime, we employ a light scattering model to extend the measurement range towards nanoparticle sizes. Industrial use cases pose additional challenges to OCT systems, namely robustness, small system cost and size, and an open path towards parallelization. Photonic integrated systems comply with these requirements, and they allow a dense integration of a multitude of systems on a single chip. We design and investigate silicon photonic integrated OCT systems that comprise interferometer and balanced photodetectors on a silicon chip.