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Accueil > EN > Research Areas > Complex Systems Dynamics > Optical Systems > Accelerator-based coherent sources

Free-Electron Lasers (FELs)

par Serge BIELAWSKI - publié le , mis à jour le

Clément Evain, Christophe Szwaj, Serge Bielawski
Marc Le Parquier (CERLA lab.)

Why Free-Electron Lasers ?

FELs can produce coherent light at short wavelengths : VUV to X-rays, with microjoule to millijoule energy.

Is there a VUV/X free-electron laser in France ?

LUNEX 5 is the French VUV/X FEL project. A large part of our activity on FEL is performed within this framework. Please check the LUNEX 5 website

Free-Electron lasers from the nonlinear dynamics point of view ?

FEL oscillators are 1-d spatio-temporal systems with a rich dynamics, including :
- Convective instabilities. See eg : Advection-induced spectrotemporal defects in a free-electron laser, PRL 95, 034801 (2005)
- Feedback control of passive Q-switch Eur. Phys. J. D 59, 451 (2010), inspired by the work of Ott, Grebogi and Yorke. One of the largest systems controlled by OGY-type feedback ?
- Feedback control of convective instabilities PRL 102,134501 (2009)
- Formal analogy between FEL oscillators and actively mode-locked lasers PRA 84, 063804 (2011)

In single-pass (VUV/X) FELs, the subject is quite open. See eg :
- Pulse Splitting in Short Wavelength Seeded Free Electron Lasers PRL 103, 264801.

Current research activities :

- Modeling and numerical calculations for the LUNEX 5 FEL based on a linear accelerator (LINAC).
- Modeling and numerical calculations for the COXINEL project (laser-wakefield accelerator-based FEL).
- Laser frequency mixing in electron bunches.
- Echo-Enabled Harmonic Generation (EEHG). A nonlinear optics process without equivalent in classical optics ?
- Ultra-high repetition rate diagnostics, using spectral encoding and photonic time-stretch.

Publications :