Elemental redistribution in glass induced by a 250-kHz femtosecond laser

We report the elemental redistribution in a Bi-doped oxyfluoride glass induced by a 250-kHz femtosecond laser. Our results show that the relative concentration of the network modifier Bi ions in the modified region is higher than that in the unmodified regions. However, the relative concentration of the network modifier Ca ions is opposed to that of Bi ions. This is the first time to observe the differential distribution of relative concentration between the network modifiers. These results are important to practical application in the fabrication of waveguide lasers and amplifiers in active ion-doped glasses.