Product Code: ICAL07_M1206

70-FS Pulses Produced by Parabolic Amplification in a Fiber Laser Amplifier
Authors:
Yoann Zaouter, Amplitude Systemes; Pessac France
D. Papadopoulos, Institut d'Optique; Palaiseau France
Eric Cormier, Centre Lasers Intenses et Applications; Talence France
Marc Hanna, Institut d'Optique; Palaiseau France
Eric Mottay, Amplitude Systemes; Pessac France
Frederic Druon, Institut d'Optique; Palaiseau France
Patrick Georges, Institut d'Optique; Palaiseau France
Presented at ICALEO 2007

Femtosecond diode-pumped Yb-doped fiber lasers are very attractive systems for athermal, high speed micromachining. They can produce simultaneously a high average power with very high efficiency, and sufficient pulse energy for laser ablation. We report on a 70-fs front-end laser using parabolic amplification. Parabolic amplification is an elegant way to amplify femtosecond pulses in a positive dispersion fiber. This method allows not only to manage non-linear effects but also uses them to get shorter pulses. In fact, parabolic amplification uses the interplay between Self Phase Modulation and Group Velocity Dispersion in presence of gain to produce purely-linear-chirped broader spectra. It is then possible to compress the amplified pulses with a shorter duration. Starting with an oscillator producing 140-fs pulses, we havedemonstrated 70-fs amplified pulses. This represents, to our best knowledge, the shortest pulses ever produced with the parabolic-amplification technique. The laser operates at 28 MHz and delivers 7W before compression (4.5W after compression). This laser is an ideal front-end for high average power, 100 W class ultrafast laser systems for high speed micromachining.