High-order harmonic generation by nonlinear reflection of an intense high-contrast laser pulse on a plasma.
We demonstrate the use of a plasma mirror to obtain 60-fs 10-TW laser pulses with a temporal contrast of 10(8) on a nanosecond time scale and 10(6) on a picosecond time scale, and we use these high-contrast pulses to generate high harmonics by nonlinear reflection on a plasma with a steep electronic density gradient. Well-collimated harmonics up to 20th order are observed for a laser intensity of approximately equal to 3 x 10(17) W/cm2, whereas no harmonics are obtained without the plasma mirror.
Monot
Pascal
P
Service des Photons, Atomes et Molécules, Commissariat à l'Energie Atomique, Centre d'Etudes Nucléaires de Saclay, 91191 Gif sur Yvette, France.
Doumy
Gilles
G
Dobosz
Sundrine
S
Perdrix
Michel
M
D'Oliveira
Pascal
P
Quéré
Fabion
F
Réau
Fabrice
F
Martin
Philippe
P
Audebert
Patrick
P
Gauthier
Jean-Claude
JC
Geindre
Jean-Paul
JP