The aim of this ITN is to take the category of Nonlinear Optical Microscopy (NOM) techniques into the nano-dimension, allowing for label-free three-dimensional (3D), dynamic imaging of macromolecular arrangements and nanostructures by probing inherent higher-order electronic and molecular vibrations with novel detection concepts. Specific S&T objectives are to (A) explore the use of nano-sized scanning probes, polarization or phase resolved detection schemes to enable nano-scale imaging, (B) benchmark their capabilities by fundamental studies and computations of molecular suprastructures and metallic nanostructures, and to (C) apply them in live-cell and fuel cell studies in order to introduce them as attractive instruments for the pharmaceutical-, nanotechnology-, and biosciences/industry. In particular, we will study (i) the formation of hierarchical structures of beta-amyloid, (ii) nonlinear emission by metallic nanoparticles/holes/antennas as potential nano-photonic devises, (iii) stem cell differentiation and metabolic expression in a 3D tissue model for drug screening and (iv) physic-chemical processes in fuel cell membranes. This sets requirements on a highly interdisciplinary and intersectoral working process. Consequently, the FINON ITN constitutes of partners from, and active interaction between, a wide range of disciplines spanning from front-line technology developers of laser instrumentation, microscopy, and nanophotonics to users of microscopy with extended experience and challenging requirements within the life-, chemical-, pharmaceutical- and material sciences. This forms an attractive training environment, with particular emphasis on early-stage and experienced researchers, offering unique networking opportunities and a vast variety of career paths.