30 W all-fiber supercontinuum generation via graded-index multimode fiber pumped by picoseconds laser pulse

We demonstrated an over 30 W all-fiber supercontinuum source based on a four-mode graded-index multimode fiber (GIMF) pumped by around 5 picoseconds laser pulse. Following the evolution of the supercontinuum, it is reasonable to conclude that the discrete spectral peaks in the range 350-700 nm were generated owing to the geometric parametric instability effect and quasi-phase matched harmonic generation, whereas the radiation of dispersive waves, stimulated Raman scattering, and relative effects of optical soliton caused spectral broadening ranging from 700 nm to 1750 nm (and even to 2400 nm). Furthermore, the properties of the supercontinua generated in the four-mode GIMF and the 50/125 standard GIMF were experimentally compared. This com-parison implied that the wavelengths radiated by the geometric parametric instability differed owing to different dispersion values. And the supercontinuum generated by the four-mode GIMF had a flatter spectral profile and a wider wavelength range.

Automated summary

We demonstrated a more than 30 W all-fiber supercontinuum source by pumping a four-mode graded-index multimode fiber (GIMF) with around 5 picoseconds laser pulse. The discrete spectral peaks in the range of 350-700 nm were found to be generated by the geometric parametric instability effect and quasi-phase matched harmonic generation, while the spectral broadening from 700 nm to 1750 nm (and even to 2400 nm) was caused by the radiation of dispersive waves, stimulated Raman scattering, and the effects of optical soliton. Furthermore, an experimental comparison between the four-mode GIMF and the 50/125 standard GIMF showed that the wavelengths radiated by the parametric instability differed due to different dispersion values, and the supercontinuum generated by the four-mode GIMF had a flatter spectral profile and a wider wavelength range.