Longitudinal coherence measurements of a transient collisional x-ray laser

Raymond F. Smith (1) , James Dunn (1) , James R. Hunter (1) , J. Nilsen (1) , Sébastien Hubert (2) , Sylvie Jacquemot (2) , Christian Remond (2) , Rémy Marmoret (2) , Marta Fajardo (3) , Philippe Zeitoun (3) , Laurent Vanbostal (3) , Ciaran L. S. Lewis (4) , Marie-Françoise Ravet (5) , Franck Delmotte (5)

1 LLNL - Lawrence Livermore National Laboratory
2 DAM/DIF - DAM Île-de-France
3 LIXAM - Laboratoire d'interaction du rayonnement X avec la matière
4 School of Mathematics and Physics [Belfast]
5 Laboratoire Charles Fabry de l'Institut d'Optique / Scop

We present what is to our knowledge the first longitudinal coherence measurement of a transient inversion collisional x-ray laser. We investigated the picosecond output of a Ni-like Pd x-ray laser at 14.68 nm generated by the COMET laser facility at the Lawrence Livermore National Laboratory. Interference fringes were generated with a Michelson interferometer setup in which a thin multilayer membrane was used as a beam splitter. We determined the longitudinal coherence for the 4d1S01→4p1P1 lasing transition to be ~400μm (1/e half-width) by changing the length of one interferometer arm and measuring the resultant variation in fringe visibility. The inferred gain-narrowed linewidth of ~0.29pm is a factor of 4 less than previously measured in quasi-steady-state x-ray laser schemes.

Domains: Optics [physics.optics]

Raymond F. Smith, James Dunn, James R. Hunter, J. Nilsen, Sébastien Hubert, et al.. Longitudinal coherence measurements of a transient collisional x-ray laser. Optics Letters, 2003, 28 (22), pp.2261-2263. ⟨10.1364/OL.28.002261⟩. ⟨hal-00873446⟩