Ultrafast Optics and X-Rays Division

Ultrafast Optics and X-rays Group at CFEL

We welcome you to our UFOX-Group Website. Here you can learn more about our research activities to push the boundaries of current ultrafast laser technology and the development of novel X-ray sources. We focus on light sources ranging from Terahertz to X-rays and their control down to attosecond precision. With the high level of control that laser sources offer, we also advance electron-based sources. We work on sources as small a a microchip as well as with sources, like the novel X-ray free-electron lasers, that can be as big as an airport. All these advances enable new techniques to understand the structure and the dynamics of matter down to their natural timescale.

Meet our Teams

The Group is led by Prof. Franz X. Kärtner and is based in the CFEL building as well as many labs across the DESY campus. Our multidisciplinary research is pursuit by several Research Teams with individual Subgroup Leaders.

We are constantly looking for excellent Bachelor, Master and PhD-students, as well as Postdoctoral Associates.

Join UFOX for a HiWi job!

We offer paid HiWi jobs for young students to join our activities. Check out our open positions.

News and Announcements

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Terahertz-driven control for ultrashort electron pulses with single-femtosecond stability

08 March, 2026
A compact THz structure integrates electron chopping and velocity bunching to generate isolated femtosecond electron bursts intrinsically synchronized to the driving THz field.

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From photon science to fusion: funding for fusion energy laser development

03 February, 2026
The UFOX Group, jointly with the Extreme Conditions Beamline team of PETRAIII @ DESY, the University of Hamburg, Helmholtz-Zentrum Dresden-Rossendorf, the University of Rostock, and the Fraunhofer Institute for Laser Technology, has been awarded the ambitious project IFuEL (short for Inertial Fusion Energy Laser Development and HED-Analytics).

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