title: Tunable flat-top nanosecond fiber laser oscillator and 280 W average power nanosecond Yb-doped fiber amplifier.
abstract: We demonstrate a nanosecond fiber laser with tunable central wavelengths and narrow spectral bandwidths suitable for high-power amplification. Spectrally narrowband flat-top nanosecond pulses were generated at the fundamental repetition rate of 1.9 MHz in an Yb-doped fiber laser, which could be tuned in central wavelength from 1033 to 1053 nm by changing the nonlinear polarization rotation in the fiber laser cavity. In particular, such flat-top nanosecond pulses could be tuned around 1030 nm to match the gain bandwidth of ytterbium-doped double-clad fibers or 1053 nm to match the maximum gain in Nd-doped phosphate glass. The pulse duration could be changed from 1 to 15 ns by varying the pump power or laser polarization evolution in the cavity. By using an ytterbium-doped single-mode fiber preamplifier and a two-stage large-mode-area Yb-doped double-clad-fiber power amplifier, 280-W average power with pulse duration of 3 ns was obtained at 1034 nm.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Wenxue
authors.initials: W
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hao
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Heping
authors.initials: H
authors.lastname: Zeng
mesh_terms: D000669:Amplifiers, Electronic; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D036103:Nanotechnology / Q000295:instrumentation*; D055100:Optical Fibers; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity