Title :
High Peak Power Pulse Amplification in Large-Core Yb-Doped Fiber Amplifiers
Author :
Galvanauskas, Almantas ; Cheng, Ming-Yuan ; Hou, Kai-Chung ; Liao, Kai-Hsiu
Author_Institution :
Univ. of Michigan, Ann Arbor
Abstract :
High peak power fiber lasers are important for a variety of applications ranging from material processing and remote sensing to laser-plasma produced extreme ultraviolet lithography (EUV) generation. These applications require high peak powers in the megawatt range, < 1-10-ns pulse durations and high average powers in preferably diffraction-limited beams. In this paper, we review our work on high peak power pulse generation using large- mode-area (LMA) Yb-doped fibers with very large cores. We report achieving up to > 5-MW peak power with subnanosecond pulses, the highest peak power achieved so far from a fiber laser. Use of a variety of core sizes between 65 and 200 mum has been explored and it has been shown that for core sizes as large as 80 mum, a good output beam quality of M2 ~ 1.3 can be maintained. This corresponds to the largest ever demonstrated mode area (2750 mum2) of a conventional LMA fiber with nearly diffraction-limited output. We also demonstrate average-power scaling of megawatt peak power pulses of up to ~90 W.
Keywords :
optical fibre amplifiers; power amplifiers; average-power scaling; fiber amplifiers; high peak power pulse amplification; megawatt peak power pulses; Diffraction; Fiber lasers; High power amplifiers; Laser beams; Laser modes; Materials processing; Power lasers; Pulse amplifiers; Remote sensing; Ultraviolet sources; Fiber laser and amplifiers; high-power solid state lasers; nonlinear fiber optics;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2007.899145