High-gain harmonic-generation free-electron laser seeded by harmonics generated in gas
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A. Gallo
- Function : Author
- PersonId : 755386
- ORCID : 0000-0002-7472-7830
Guillaume Lambert
- Function : Author
- PersonId : 4339
- IdHAL : guillaume-lambert
- IdRef : 129226882
Abstract
The injection of a seed in a free-electron laser (FEL) amplifier reduces the saturation length and improves the longitudinal coherence. A cascaded FEL, operating in the high-gain harmonic-generation regime, allows us to extend the beneficial effects of the seed to shorter wavelengths. We report on the first operation of a high-gain harmonic-generation free-electron laser, seeded with harmonics generated in gas. The third harmonics of a Ti:sapphire laser, generated in a gas cell, has been amplified and up-converted to its second harmonic (?rad=133nm) in a FEL cascaded configuration based on a variable number of modulators and radiators. We studied the transition between coherent harmonic generation and superradiant regime, optimizing the laser performances with respect to the number of modulators and radiators. © 2011 American Physical Society.