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.