Design and characterization of a near-diffraction-limited femtosecond 100-TW 10-Hz high-intensity laser system

Abstract : We present the design and characterization of a femtosecond high-intensity laser system emitting a near-diffraction-limited beam. This system was dimensioned in order to reach intensities in excess of 10^20 W/cm^2 at a high repetition rate for ultrahigh-field physics experiments. We describe the improvements that were added to a conventional chirp pulse amplification configuration in order to decrease the deleterious effects of gain narrowing, gain shifting, thermal focusing in the amplifier stages, and spatial degradation due to multipass amplification processes.