Dr. Rothhardt was intensively engaged in applications of these laser systems. He was able to show both mathematically and experimentally for the first time that efficient conversion into the XUV spectral range is also possible with high power lasers of high pulse repetition frequency. For research, this means that the XUV sources developed by him will enable worldwide unique laser spectroscopy experiments at so-called heavy ion storage rings.

The Röntgen Prize is awarded for outstanding work in basic research in radiation physics and radiation biology. It is named after Wilhelm Conrad Röntgen, who was a professor in Giessen from 1879 to 1888. The prize is primarily intended to honor work by young scientists. The prize, which is endowed with 15,000 euros, is sponsored in equal parts by Pfeiffer Vacuum and the Ludwig Schunk Foundation.