Characterization of collisionally pumped optical-field-ionization soft X-ray lasers

Tomas Mocek (1) , Stéphane Sebban (1) , Islam Bettaibi (1) , L. M. Upcraft (1) , Philippe Balcou (1) , P. Breger (2) , Philippe Zeitoun (3) , S. Le Pape (3) , David Ros (3) , Annie Klisnick (3) , A. Carillon (3) , G. Jamelot (3) , B. Rus (4) , J.-F. Wyart (5)

1 LOA - Laboratoire d'optique appliquée
2 SPAM - Service des Photons, Atomes et Molécules
3 LIXAM - Laboratoire d'interaction du rayonnement X avec la matière
4 Department of X Ray Lasers
5 LAC - Laboratoire Aimé Cotton

We give an overview of recent experimental results on optical-field-ionization collisional soft X-ray lasers developed at LOA. By focusing a 30-fs, circularly polarized Ti-sapphire laser pulse at an intensity of up to 8×10^17 Wcm^-2 into a low-density gas cell containing Xe or Kr, we produced a few mm long plasma column for soft X-ray amplifier. Saturated amplification has been achieved on the 4d^95d(1S0)–4^95p(1P1) transition at 41.8 nm in Xe8+, and on the 3d^94d(1S0)–3d^94p(1P1) transition in Kr8+ at 32.8 nm. Under optimum pumping conditions the Xe8+ laser provides about (5±2)×10^9 photons per pulse whilst the Kr8+ laser delivers up to (2.5±1)×10^9 photons per shot. The repetition rate of these soft X-ray lasers is 10 Hz. The beam wavefront of the Xe8+ laser has been measured by a Shack–Hartmann soft X-ray wavefront sensor, and the pulse duration by a cross-correlation technique.

Domaines: Optique [physics.optics]

Tomas Mocek, Stéphane Sebban, Islam Bettaibi, L. M. Upcraft, Philippe Balcou, et al.. Characterization of collisionally pumped optical-field-ionization soft X-ray lasers. Applied Physics B - Laser and Optics, 2004, 78 (7-8), pp.939-944. ⟨10.1007/s00340-004-1436-3⟩. ⟨hal-00522717⟩