Full-aperture chirped-pulse grating compression with a non-uniform beam

A novel chirped-pulse compression scheme is proposed to pursue higher pulse peak power of chirped-pulse amplifiers based on state-of-the-art gratings. It is characterized by the spectral non-uniformity of the beam cross section as well as by the uniform size of the beam projections on the four compression gratings. The spatial distribution of spectra is well designed so that the beam can remain generally collimated in the compressor and the gratings can be employed with a full work area. The maximum possible output pulse energy can therefore be increased within the damage threshold limit. A detailed design is developed for a scheduled 50-PW optical parametric chirped-pulse amplifier. Results of the numerical simulation on the focused output show that the spot size and pulse duration in the focal plane are close to those of conventional grating compression. Further, it is a promising method for upgrading existing chirped-pulse amplifiers.