From the fundamentals to a concrete product: In a new, international research consortium, the Laser Zentrum Hannover e.V. (LZH) is investigating an innovative approach to the generation of the “third harmonic”. Up to now, much time and effort is necessary to generate coherent radiation in the ultraviolet spectral range. Current investigations should show whether this can be achieved with a conversion efficiency of at least 15 % in the future by means of dielectric layer systems. Subsequently, the research team will be considering the scalability and market potential of this new process, too.

Either fast or precise – both cannot be achieved in the production of the finest polymer structures with the laser. Or maybe they can? Combining stereolithography and multiphoton polymerization should make it possible: Scientists at the Fraunhofer Institute for Laser Technology ILT are developing a machine for high-precision, cost-effective 3D construction technologies using both methods. On November 1, 2018, Fraunhofer ILT and its project partners launched the project “High Productivity and Detail in Additive Manufacturing through the Combination of UV Polymerization and Multi-Photon Polymerization – HoPro-3D”, which is funded by the European Union and the state of North Rhine-Westphalia.

High-harmonic lightwaves tailored on demand by crystal symmetry. Light is made of an oscillating electric and magnetic field. In order to tune its properties, one would ultimately like to shape these fields directly – a specifically daunting challenge when the oscillation frequency is high. A team of physicists from Regensburg (Germany), Marburg (Germany), and Ann Arbor (USA) has now realized a way to directly tailor lightwaves emitted by accelerated electrons inside a solid, with the aid of the crystal’s symmetry. The results of this breakthrough will be reported in the upcoming issue of Nature Photonics. For several years, physicists have been able to routinely produce extremely short flashes of light in the hard ultraviolet or even soft x-ray spectral region. For this purpose, a method called high-harmonic generation is employed, where a strong near-infrared laser rips electrons from an atomic gas and slams them back into the nuclei to emit ultraviolet radiation upon recollision.