Amplification of down- and up-chirped pulses in Ti:sapphire

The modern Ti:sapphire lasers reach output powers close to the Petawatt level. Efficient consumption of the pump energy requires saturated pulse amplification which is usually employed in high peak power lasers. Here we propose to use a combination of downchirped amplification (DCA) and upchirped amplification to correct for the gain narrowing appearing in high peak power Ti:sapphire laser systems. Contrary to upchirped pulses, the downchirped pulse has blue spectral components at the leading edge. Thus, saturating an amplifier in this case leads to a blue shifting of the laser pulse spectrum forming a spectral shape with a sharp blue edge and a smooth red one, similar to the optimum required for broad spectrum amplification.