Limits of Femtosecond Fiber Amplification by Parabolic Pre-Shaping
  We explore parabolic pre-shaping as a means of generating and amplifying ultrashort pulses. We develop a theoretical framework for modeling the technique and use its conclusions to design a femtosecond fiber amplifier. Starting from 9 ps pulses, we obtain 4.3 $\mu$J, nearly transform-limited pulses 275 fs in duration, simultaneously achieving over 40 dB gain and 33-fold compression. Finally, we show that this amplification scheme is limited by Raman scattering, and outline a method by which the pulse duration and energy may be further improved and tailored for a given application. 
Walter Fu, Yuxing Tang, Timothy S. McComb, Tyson L. Lowder, Frank W.   Wise
physics.optics