Passively Q-switched Ytterbium and Chromium all-fibre laser
  A chromium-doped saturable absorber fibre stabilizes an otherwise spontaneously chaotic ytterbium- doped fibre laser. This original passively Q-switched all-fibre laser produces sustained and stable trains of smooth pulses at high repetition rate. 
Bernard Dussardier (LPMC UMR 7336), Jerome Maria (LPMC), Pavel Peterka
physics.optics