Femtosecond laser induced microstructure and luminescence changes in oxyfluoride tellurite glasses

•Tellurium nanoparticles have been precipitated in glass by femtosecond laser.•The microstructure modification in the laser focal plane is performed.•The luminescence property of Er3 +-doped glass changes in the irradiated zone.•The mechanism based on the photo-ionization process is interpreted.

We report on microstructure modification and local luminescence change in oxyfluoride tellurite glasses induced by a 1030 nm, 500 kHz femtosecond laser. Tellurium nanoparticles are precipitated in the laser-modified region based on X-ray diffraction analysis and transmission electron microscopy observation. Micro-Raman spectra and energy dispersive spectroscopy show that migration of ions (Te4 +, Zn2 + and O2−) and coordination state transformation of Te4 + ions occurred after the irradiation. The luminescence property of Er3 +-doped glass also changes in the irradiated zone. The mechanisms of above phenomena are interpreted. During the 500 kHz femtosecond laser irradiation, photo-ionization process plays a significant role in the precipitation of Te crystalline phase. The creation of sharp temperature gradient results in modification of element distribution, which leads to the coordination change of Te4 + ions and luminescence change of Er3 + ions. These results are of reference value to fabricate integrated optical waveguide amplifiers and lasers in oxyfluoride tellurite glasses.