Limits of Femtosecond Fiber Amplification by Parabolic Pre-Shaping

TL;DR

This paper investigates parabolic pre-shaping for ultrashort pulse amplification, demonstrating a fiber amplifier that achieves high gain and compression from 9 ps pulses to 275 fs, limited by Raman scattering.

Contribution

It provides a theoretical framework and practical design for femtosecond fiber amplifiers using parabolic pre-shaping, highlighting limitations and potential improvements.

Findings

Achieved 4.3 μJ, nearly transform-limited 275 fs pulses from 9 ps input pulses.

Over 40 dB gain and 33-fold pulse compression.

Amplification limited by Raman scattering, with proposed methods for enhancement.

Abstract

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.