Postdoctoral Scientist / Researcher (m/f/d) in the field of ultra-short pulse laser physics / optical frequency combs Posting ID: 26.127-4210

The Helmholtz Institute Jena (HI Jena) is a joint institution of the Friedrich-Schiller-Universität Jena and the GSI Helmholtz Centre for Heavy Ion Research GmbH in Darmstadt. The institute is mainly focused on applied and fundamental research at the borderline of high-power lasers and particle accelerators. It maintains close collaborations with the Helmholtz Centers DESY in Hamburg, and HZDR in Dresden.

For a position in the research group “Laser Science and Technology” located at DESY , we are looking for a

Postdoctoral Scientist / Researcher (m/f/d) in the field of ultra-short pulse laser physics / optical frequency combs

Posting ID: 26.127-4210

Your tasks:

Nuclear spectroscopy of 229 Thorium is a highly interesting field of research at the intersection between nuclear and atomic physics, which deals with the properties of an exceptionally low excited state in the atomic nucleus of 229 Thorium. This state has an estimated excitation energy of only around 8 eV. Only recently has it been possible to excite this state directly with an optical laser. As part of the HiTHOR project based at the Helmholtz Institute Jena and funded by the European Research Council ERC , this nuclear transition is now to be investigated in detail, which promises unique new insights into the quantum physics of atomic nuclei as well as new approaches for the construction of a high-precision ‘nuclear clock’.

Within this project, the further development of a frequency comb laser in the vacuum-ultraviolet (VUV) spectral range will be pursued. In contrast to existing VUV comb systems, a novel, much more efficient approach will be targeted. This work will also include the development of the laser’s feedback control systems, as well as its adaptation to planned 229 Thorium ion spectroscopy experiments at GSI. The successful candidate is expected to co-supervise a PhD student working in this project.

We are looking for candidates who have:

• a completed PhD degree in physics, electrical engineering or similar field,
• excellent experience and expertise in the field of laser stabilization, frequency combs, phase-locked loops, proven by relevant publication track record,
• experience in the field of fiber lasers and nonlinear optics,
• ideally, knowledge of electronics, Python and FPGA (VHDL) programming,
• interest in working with experts on a cross-institute collaboration project,
• very good written and spoken English language skills,
• and excellent teamworking skills.

What we offer:

A fixed-term 3-year contract embedded in the Helmholtz Association, Germany’s largest research foundation, with the salary and benefits based on the Collective Agreement for the German Public Service (TVöD-Bund) effective at GSI. The position will be established at the Helmholtz Center DESY in Hamburg.

GSI promotes the professional development of women and expressly welcomes applications from women. Handicapped persons will be preferentially considered when equally qualified.

GSI and FAIR is available at www.hi-jena.de , www.gsi.de and www.fair-center.eu .

For any questions please contact Prof. Dr. Thomas Stöhlker ( , Phone: .)

If you find this position interesting, please submit your full application documents, including your desired salary, your earliest possible starting date and the posting ID 26.127-4210 by October 9, 2026 at the latest

through our online portal

GSI Helmholtzzentrum für Schwerionenforschung GmbH

Abteilung Personal

Planckstrasse 1

64291 Darmstadt