High-order-harmonic generation: towards laser-induced phase-matching control and relativistic effects

Philippe Balcou (1) , R. Haroutunian (1) , Stéphane Sebban (1) , G. Grillon (1) , Antoine Rousse (1) , G. Mullot (1) , Jean-Paul Chambaret (1) , G. Rey (1) , André Antonetti (1) , D. Hulin (1) , L. Roos (2) , D. Descamps (2) , M. B. Gaarde (2) , A. L'Huillier (2) , E. Constant (3) , E. Mevel (3) , D. von Der Linde (4) , A. Orisch (4) , A. Tarasevitch (4) , U. Teubner (5) , D. Klöpfel (5) , W. Theobald (5)

1 LOA - Laboratoire d'optique appliquée
2 Department of Physics
3 CELIA - Centre d'Etudes Lasers Intenses et Applications
4 Institut für Laser- und Plasmaphysik
5 Institut für Optik und Quantenelektronik

We present a review of some recent results on high-order-harmonic generation, aiming at optimizing the photon flux to allow for future applications in extreme-ultra-violet non-linear optics. We first present new schemes to control phase matching of high harmonics in gases, by using the effect of the spatially varying atomic phase displayed by the high harmonics. An enhancement by a factor of 50 is observed in neon in conditions for which the gradient of the atomic dispersion balances the electronic dispersion. A new scheme to manipulate the laser field was demonstrated, and shown to improve phase matching. We then turn to high-harmonic generation by solid targets, and show that high harmonics generated by an intense 30-fs laser pulse remain collimated even at the threshold of the relativistic regime.

Domains: Optics [physics.optics]

Philippe Balcou, R. Haroutunian, Stéphane Sebban, G. Grillon, Antoine Rousse, et al.. High-order-harmonic generation: towards laser-induced phase-matching control and relativistic effects. Applied Physics B - Laser and Optics, 2002, 74 (6), pp.509-515. ⟨10.1007/s003400200797⟩. ⟨hal-00523268⟩