In biophotonics optical tools are employed for the understanding and treatment of diseases, from the cellular level to macroscopic applications. At the cellular level, highly precise laser applications allow the manipulation, poration or stimulation of cells, even in living organisms or animals, like for example in optogenetics. Using fusion proteins, precise imaging and, in case of channelrhodopsin, precise switching of living cells in their environment is enabled and allows a deeper understanding of cellular processes. Furthermore, optical microscopy has been revolutionized by a thorough understanding of the different markers and their switching behaviour. Marker-free microscopy, like CARS, SHG or THG-microscopy is spreading into multiple biological and clinical imaging applications. Combination with microfluidics and chip-based technologies enables high-throughput for screening or manipulation applications.
    Optical Coherence Tomography (OCT) is continuously broadening its clinical applicability by even higher resolution, higher speed and more compact or fibre-based probes and the use of Doppler and polarization sensitivity for functional imaging. The combination of these OCT capabilities with (nonlinear) microscopic techniques, fluorescence and laser surgery techniques provides excellent opportunities in clinical applications. Multifunctional catheters are needed for different clinical areas to accommodate the ever increasing acquisition speeds. This Topical Meeting aims at covering several aspects from the fundamental studies at the cellular level to clinical applications of various optical technologies.