High-energy petawatt lasers using the chirped-pulse amplification technique require meter-sized gratings to limit the beam fluence on the surface of the grating. An alternative, studied by many groups, is a mosaic grating consisting of smaller, coherently added gratings. We propose what we believe to be a new compression scheme consisting of beam phasing instead of grating mosaic phasing. This synthetic aperture compression scheme allows us to control the beam thanks to a unique segmented mirror equipped with three degrees of freedom. With this configuration, the beam is divided into small subapertures adapted to the classical grating size. After compression, these subapertures are coherently added before the focusing stage. Therefore the alignment processes are simplified.
© 2006 Optical Society of America
Original Manuscript: December 5, 2005
Revised Manuscript: March 6, 2006
Manuscript Accepted: March 16, 2006
N. Blanchot, G. Marre, J. Néauport, E. Sibé, C. Rouyer, S. Montant, A. Cotel, C. Le Blanc, and C. Sauteret, "Synthetic aperture compression scheme for a multipetawatt high-energy laser," Appl. Opt. 45, 6013-6021 (2006)