Europhys. Lett.
Volume 74, Number 5, June 2006
Page(s) 823 - 829
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 10 May 2006
Europhys. Lett., 74 (5), pp. 823-829 (2006)
DOI: 10.1209/epl/i2006-10038-4

Origin of microstructures in picosecond X-ray laser beams

O. Guilbaud1, A. Klisnick1, K. Cassou1, S. Kazamias1, D. Ros1, G. Jamelot1, D. Joyeux2 and D. Phalippou2

1  LIXAM, Laboratoire d'Interaction du rayonnement X Avec la Matière CNRS UMR 8624, Université Paris Sud - Bâtiment 350, 91405 Orsay Cedex, France
2  LCFIO, Laboratoire Charles Fabry de l'Institut d'Optique, Centre scientifique d'Orsay Bâtiment 503, 91403 Orsay Cedex, France

received 2 January 2006; accepted in final form 6 April 2006
published online 10 May 2006

Beam sections of transient collisional excitation (TCE) soft X-ray lasers exhibit highly contrasted intensity modulations forming complex patterns. We present model calculations that reproduce these experimental observations both qualitatively and quantitatively. The low spatial coherence, high longitudinal coherence and short pulse duration of the source are shown to control the visibility of the beam structures. Comparison with other types of laser-based soft X-ray lasers is discussed. We derive simple relationships that relate the spatial and temporal characteristics of the emitting source to the main features of the beam small-scale structures.

42.55.Vc - X- and gamma-ray lasers.
42.50.Gy - Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption.
42.60.Jf - Beam characteristics: profile, intensity, and power; spatial pattern formation.

© EDP Sciences 2006