Abstract:
We report on the study of direct amplification of femtosecond pulses in an 80μm core diameter microstructured Yb-doped rod-type fiber amplifier in the nonlinear regime. The system includes a compact single grating compressor for the compensation of the small dispersion in the amplifier. With a 1250line/mm (l/mm) grating-based compressor, pulses as short as 49fs with 870nJ pulse energy and 12MW peak power are obtained. Alternatively, the use of a 1740l/mm grating allows the production of higher quality pulses of 70fs , 1.25μJ pulse energy, and 16MW peak power.