Optimization of the dynamic wavefront control of a pulsed kilojoule/nanosecond-petawatt laser facility.
The wavefront aberrations in a large-scale, flash-lamp-pumped, high-energy, high-power glass laser system can degrade considerably the quality of the final focal spot, and limit severely the repetition rate. The various aberrations induced on the Laboratoire pour l'Utilisation des Lasers Intenses (LULI), laser facility (LULI2000) throughout the amplification are identified and analyzed in detail. Based on these analyses, an optimized procedure for dynamic wavefront control is then designed and implemented. The lower-order Zernike aberrations can be effectively reduced by combining an adaptive-optics setup, comprising a bimorph deformable mirror and a four-wave lateral shearing interferometer, with a precise alignment system. This enables the laser chain to produce a reproducible focal spot close to the diffraction limit (Strehl ratio approximately 0.7). This allows also to increase the repetition rate, initially limited by the recovery time of the laser amplifiers, by a factor of 2 (one shot per hour). The proposed procedure provides an attractive alternative for dynamic correction of the wavefront aberrations of a laser facility as complex as the LULI2000.
Zou
Ji-Ping
JP
Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, CNRS, Commissariat a l'Energie Atomique, Université Pierre et Marie Curie, Palaiseau, France. ji-ping.zou@polytechnique.fr
Sautivet
Anne-Marie
AM
Fils
Jérôme
J
Martin
Luc
L
Abdeli
Kahina
K
Sauteret
Christian
C
Wattellier
Benoit
B