High-gain harmonic-generation free-electron laser seeded by harmonics generated in gas

M. Labat (1, 2) , M. Bellaveglia (3) , M. Bougeard (4) , B. Carré (4) , F. Ciocci (1) , E. Chiadroni (3) , A. Cianchi (3, 5) , M.E. Couprie (2) , L. Cultrera (3) , M. del Franco (1) , G. Di Pirro (3) , A. Drago (3) , M. Ferrario (3) , D. Filippetto (3) , F. Frassetto (6) , A. Gallo (3) , D. Garzella (4) , G. Gatti (3) , L. Giannessi (1) , Guillaume Lambert (7) , A. Mostacci (8) , A. Petralia (9) , V. Petrillo (10, 11) , L. Poletto (6) , M. Quattromini (1) , J.V. Rau (12) , C. Ronsivalle (1) , E. Sabia (1) , M. Serluca (8) , I. Spassovsky (1) , V. Surrenti (1) , C. Vaccarezza (3) , C. Vicario (13)

1 ENEA - Italian National agency for new technologies, Energy and sustainable economic development [Frascati]
2 SSOLEIL - Synchrotron SOLEIL
3 LNF - Laboratori Nazionali di Frascati = National Laboratory of Frascati
4 SPCSI - Service de Physique et de Chimie des Surfaces et Interfaces
5 INFN, Sezione di Roma Tor Vergata - Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata
6 IFN - CNR Istituto di Fotonica e Nanotecnologie [Padova]
7 LOA - Laboratoire d'optique appliquée
8 UNIROMA - Università degli Studi di Roma "La Sapienza" = Sapienza University [Rome]
9 ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati, Roma, Italy
10 UNIMI - Università degli Studi di Milano = University of Milan
11 INFN-Mi, Via Celoria, 16 20133 Milano, Italy
12 CNR-ISM - Istituto di Struttura della Materia
13 PSI - Paul Scherrer Institute

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.

Domaines: Optique [physics.optics]

M. Labat, M. Bellaveglia, M. Bougeard, B. Carré, F. Ciocci, et al.. High-gain harmonic-generation free-electron laser seeded by harmonics generated in gas. Physical Review Letters, 2011, 107 (22), ⟨10.1103/physrevlett.107.224801⟩. ⟨hal-00964902⟩