A significant progress has been made in controlling the properties of the radiation emitted by a FEL amplifier. Experiments have demonstrated the possibility both to increase the temporal coherence and to reduce the amplifier length to reach saturation, by seeding it with an external source. This may be a solid state, short pulse, laser (Ti:Sa,OPA..), doubled or tripled in a crystal, or a high order harmonic pulse generated in gas. The coherence improvement and the increased compactness of the source are only the first beneficial offspring of this marriage between the optical laser world and that of FELs. Non-linear effects in the seeded FEL dynamics may be exploited to shorten the pulse length beyond that allowed by the FEL natural gain bandwidth. Multiple seed pulses can be used to generate pulses whose temporal distance and properties are also controlled. Similarly, the FEL gain can be adapted to match the seed properties by tailoring the electrons phase space to generate ultra-short output pulses at unparalleled intensities.
|Titolo:||Pulse control in a free electron laser amplifier|
|Data di pubblicazione:||2014|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|