The effect of ZnF2 on the near-infrared luminescence from thulium doped tellurite glasses

In the present study, the low OH content, thulium doped fluorotellurite glasses are defined as low-quenching materials. Two lines of evidence, lifetime and emission spectra measurements, have shown that the depletion of the 3H4 state by cross relaxation processes was highly efficient. The links in question, together with the linear concentration-quenching dependence of the 3F4 state, indicated the regime of fast diffusion processes. The addition of ZnF2 to a tellurite based host significantly improved self-quenching reduction especially for highly doped samples. The increase of the 3F4 state lifetime value for a different ZnF2/ZnO ratio in the glass samples, fabricated inside a glove box, has been demonstrated and discussed.