Nonlinear fiber amplifier with tunable transform limited pulse duration from a few 100 to sub-100-fs at watt-level powers.

We report a fiber amplifier system with an output transform limited pulse duration that is broadly tunable from 400 to 60 fs. We produce <100 fs pulses with >200 kW of peak power by compensating a significant amount of third-order dispersion. The spectral noise characteristics are also investigated to insure highly stable supercontinuum generation.