The 6 academic and 2 industry teams in HICONO conducted a broad variety of fundamental experimental studies to coherently control high-intensity frequency conversion driven by high-intensity laser pulses, applications of such processes to nonlinear ultrafast spectroscopy and microscopy, as well as development of commercially relevant enabling technologies. The investigations aimed at spatial resolutions down to the size of a single molecule, and temporal resolutions down to the attosecond regime. The findings already lead to 14 publications (additional papers in preparation, submitted, or in press), a novel demonstration device for ultra-precise distance measurement, and a novel commercial device for characterization of ultra-fast laser pulses. Some specific highlights in the research projects of the individual teams are: TUDA combined resonance enhancements and quasi-phase matching to improve the brightness of frequency conversion processes towards vacuum-ultraviolet (VUV) radiation in a gas-filled capillary. Moreover, the team developped novel variants of nonlinear third-harmonic microscopy enabling higher contrast and/or larger signal yield. Nonlinear microscopy enables imaging of otherwise fully transparent optical samples. IC generated VUV pulses with a high efficiency from laser-ablation plumes, and also conducted related investigations on harmonic generation from liquids, which we found to be an advantageous alternative medium. The team developped a target system with unique capabilities, i.e. stable flow in vacuum and liquid sheets with thickness down to the micrometer regime. With the setup IC demonstrated harmonics reaching large photon energies beyond 30 eV. The findings drive laser light sources towards sufficiently intense pulses at ever shorter wavelengths and higher resolutions. ICFO achieved a breakthrough imaging the three-dimensional atomic-scale arrangement of molecular systems, by applying laser-induced electron self-diffraction. The latter enables imaging of molecular reactions with accuracies down to the size of a single molecule and the ultra-fast time scale of molecular motion. This serves to understand and finally control chemical reactions towards desired outcomes. QUB worked on generating high harmonic radiation using the unique JETI200 laser system, which operates at very high pulse intensities. UOXF developed and successfully implemented new approaches to measure and characterize complex, ultra-fast light pulses by space-time interferometry. Such devices are an essential component of any technology involving ultra-short laser pulses, and, hence, also of commercial potential. Moreover, UOXF achieved a first implementation of high harmonic generation in a gas-filled hollow core photonic crystal fiber to provide a bright ultra-fast light source. The industry team LUPH extended the possibilities of an ultra-precise distance sensor, i.e. to increase the data rate by electro-optical modulation (EOM). The investigations lead to a new prototype for improved distance measurements, which is of commercial relevance for a multitude of optics applications, where precise distance information down to the range of one nanometer is required. The findings will lead to an improved version of the commercially available LUPHOSCAN device soon. The industry team FTL successfully developped a novel, commercial device for temporal characterization of few cycle, mid-infrared laser pulses. This is required in any laser technology applying such pulses. With the trade name FROZZER the device is now already part of the commercially available product portfolio of FTL.
