Spatiotemporal pulses from a Q-switched multimode fiber laser

Abstract

We have demonstrated spatiotemporal pulses from a Q-switched ytterbium-doped multimode fiber laser, with a pulse energy of up to 16.5 μJ, a pulse repetition rate of 108.7 kHz, and an average output power of 1.80 W. Benefiting from the weakened spectral filtering effect, there is high pulse energy that can be produced from multimode fiber oscillators. We have observed and analyzed the evolution of multimode Q-switching with spatiotemporal correlation. Furthermore, we find that the polarization control in the saturable absorber has a modulation and selective effect on the transverse modes of the multimode fiber laser. Our results help to understand the spatiotemporal characteristics of pulsed fiber lasers and contribute to developing high-pulse energy lasers.