High-energy lasers (HELs) are emerging as a disruptive technology and a game changer in both scientific research and defense applications. Key to this progress are advances in fiber lasers and beam combining. Initially confined to telecommunications, fiber lasers have been rapidly adopted across industries thanks to their compactness, high efficiency, and robustness. Moreover, they offer excellent beam quality and can be readily combined, enabling laser sources exceeding 100 kW. This opens new applications in a defense context. Unlike conventional weapon systems, HEL systems engage targets at the speed of light with great precision while drawing only electrical power. They therefore have an almost unlimited magazine and a cost per shot of only a few euros. They are ideal for tasks that require high accuracy, such as countering drones (UAVs/UAS).
In this issue of visIT, we share our insights into this technology and provide an overview of our expertise and ongoing projects, ranging from end-to-end system design, integration, and modeling to the development of novel materials and components for laser sources.
We begin with an article on our mobile high-energy laser system HELIKS with coherent beam coupling (CBC), which serves as a testbed to investigate scientific questions in laser safety, atmospheric laser propagation, and laser-matter interaction. Subsequent contributions explore tracking of objects such as drones; laser beam propagation through the atmosphere, including experiments in a cloudchamber setup; beam control via adaptive optics; the investigation of potential hazards during HEL operation; and, finally, laser source development alongside the development of novel materials and components. We also show how HELIKS enables performance measurements in real-world environments, which in turn inform our full-system simulations that integrate all aspects of HEL systems. Only in this way can the full potential of HEL technology be unlocked for diverse defense applications.
We hope you find this issue both informative and enjoyable.
Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB 
