Amplification of 26-fs, 2-TW pulses near the gain-narrowing limit in Ti:sapphire

Abstract
We report the generation of 26-fs-duration pulses, with an energy of 60 mJ, from a simple multipass Ti:sapphire amplifier system. The peak power of our amplified pulses is 2 TW, and the repetition rate is 10 Hz. Our amplifier design consists of two highly doped multipass amplifiers and is simple and compact. We use an all-reflective, low-groove-density grating stretcher and compressor, combined with a relatively short material path length in the amplifier. This design allows us to minimize higher-order dispersion. The result is a laser system that generates multiterrawatt transform-limited pulses, with good beam quality and low amplified-spontaneous-emission levels, at a duration near the theoretical limit imposed by gain narrowing in Ti:sapphire.