PhD position in experimental ultrafast optics at CELIA, Bordeaux, France (Deadline: 31.05.2025)

Position Description

Over the past decade, Ytterbium laser technology has sparked a true revolution in laser-based sciences. With the ability to provide high-repetition-rate, high-power laser sources, it has opened new fields of investigation. At the same time, research programs as HORIZON at CELIA have emerged worldwide to push the Ytterbium technology to the kW level with an energy of 1 Joule at 1 kHz repetition rate with picosecond pulse durations. However, long limited to the picosecond regime, the combination of Ytterbium lasers with femtosecond post-compression systems based on nonlinear optics in gases or transparent media has made it possible to increase the peak power of these systems to the terawatt (TW) level, challenging
the long-dominant Ti:sapphire technology.

The objective of this doctoral work is to conduct a theoretical and experimental study on the post-compression of high-energy picosecond pulses with a “flat-top” spatial distribution. Unlike post-compressed pulses obtained from Gaussian beams, this shaping will ensure a uniform pulse duration across the entire aperture, thereby minimizing the temporal impact of spatio-temporal coupling at the focal point of interaction. During this thesis, a post-compression beamline based on self-phase modulation in thin films or silica plates with flat-top beam profiles will be explored using the HORIZON facility, which delivers picosecond pulses at 1 kHz with energies ranging from 20 mJ to over 500 mJ. Additionally, the PhD student will study the effects of “top-hat” shaping on the final spatio-temporal coupling of post-compressed pulses at the target. All the equipment for the postcompression beamline has been already procured. Simulations of the post-compression process and the time-space propagation up to the interaction point will also be conducted. This doctoral work aims to bring HORIZON to a unique world-class TW laser facility with kW average power.

Requirements

• Master degree in physics or photonics preferably including qualifications in the areas of optics, lasers physics and nonlinear optics.
• Experience in ultrafast optics will be an asset
• Strong skills and motivation for experimental work
• Knowledge in numerical methods and programming (Matlab, Python)
• Good communication skills in English are required, basic notion of French would be desirable.

More information – Contact

stephane.petit@u-bordeaux.fr, Université Bordeaux, CELIA, 33400 Talence, France

Application deadline: 31 May 2025