We take advantage of nonlinear properties associated with chi(3) tensor elements in BaF2 cubic crystal to improve the temporal contrast of femtosecond laser pulses. The technique presented is based on cross-polarized wave (XPW) generation. We have obtained a transmission efficiency of 10% and 10^-10 contrast with an input pulse in the millijoule range. This filter does not affect the spectral shape or the phase of the cleaned pulse. It also acts as an efficient spatial filter. In this method the contrast enhancement is limited only by the extinction ratio of the polarization discrimination device.
© 2005 Optical Society of America
Aurélie Jullien, Olivier Albert, Frédéric Burgy, Guy Hamoniaux, Jean-Philippe Rousseau, Jean-Paul Chambaret, Frédérika Augé-Rochereau, Gilles Chériaux, Jean Etchepare, Nikolay Minkovski, and Solomon M. Saltiel, "10^-10 temporal contrast for femtosecond ultraintense lasers by cross-polarized wave generation," Opt. Lett. 30, 920-922 (2005)