Ultra-broadband near-infrared pulse generation by noncollinear OPA with angular dispersion compensation

A scheme for the generation of an ultra-broadband, near-infrared beam from a Ti:sapphire source is proposed with the aim to serve as seed pulse of a petawatt-field synthesizer (Major et al. in Rev. Laser Eng. 37:431, 2009). The idler beam of a noncollinear optical parametric amplifier, pumped at the second harmonic of the Ti:sapphire output, displays the required bandwidth, albeit with an inherent angular chirp owing to the noncollinear geometry. We propose a scheme for the compensation of this angular dispersion which consists of a diffraction grating, a telescope and a deformable mirror. The suitability of this scheme is discussed quantitatively and preliminary experimental findings are shown.