Double Grating Expanders for Fourth-Order Dispersion Compensation in Chirped Pulse Amplifiers

A scheme of double grating expanders is first proposed for high energy chirped pulse amplifiers. It is demonstrated that they can compensate for the amplifier's material dispersion up to the fourth-order, together with a suitable grating compressor. The scheme makes it possible that the pulse expansion in Chirped pulse amplifiers (CPAs) is no longer restricted by the material dispersion, and the corresponding grating compressor can be independently optimized according to the available gratings' size and damage threshold.