0.75-6 μm supercontinuum generation using spatiotemporal nonlinear dynamics in graded index multimode fiber

The periodic self-imaging of a beam in graded index multimode fibers (GIMFs) is at the root of a variety of nonlinear spatiotemporal phenomena, such as Kerr beam self-cleaning [1] and geometrical parametric instabilities (GPI) [2] . These rich dynamics opens new opportunities for tailoring the laser radiation in space, time and frequency. Here, we demonstrate that the interplay between the various manifestations of nonlinearities in GIMFs can be controlled, in order to produce a three-octave-spanning supercontinuum (SC) ranging from 0.75 to 6 μm in a cascade of silica, fluoride and chalcogenide glass fibers. This optimization allows us to leverage 1 μm laser technology, instead of the widespread 2 μm laser technology, to produce mid-infrared (mid-IR) SC. These results pave the way to hyperspectral applications such as spectroscopy, medical imaging or sensing in disjoint spectral domains, without the need for either several laser sources or slow, mechanically tunable sources [3] .