Second harmonic generation based on a 1 μm femtosecond fiber CPA system

Abstract

We demonstrated a femtosecond green laser operating at 532 nm by frequency doubling of a 1 pm linearly-polarized all-fiber-integrated femtosecond chirped pulse amplification system. The 1-pm broad-spectrum seed with a 3 dB spectral bandwidth of 11.3 nm was founded by dispersive wave technology. The average power was scaled up to 6.5 W by two stage ytterbium-doped fiber amplifier and the pulse duration was compressed to 371 fs through grating pair compressor. Finally, a maximum green laser power of 1.25 W was achieved with an input power of 4.7 W by a 5×5×2 mm BBO crystal, corresponding to a conversion efficiency of 26.6 %.