Energy transfer upconversion on neodymium doped phosphate glasses investigated by Z-scan technique

•We used the well known Z-scan technique to investigate an energy transfer process.•Experimental setup and data analysis are simpler than in conventional techniques.•Experimental data indicates that the ETU process is due to energy migration, mainly.•It is possible to use such a data to calculate the parameters needed to design some optical devices.

Time-resolved Z-scan measurements were employed to characterize energy transfer upconversion on the phosphate glass matrix, named PAN (P2O5–Al2O3–Na2CO3), doped with increasing Nd3+ concentrations. It was observed a linear dependence of the upconversion parameter with the dopant agent, which indicates the presence of a static and dynamic energy transfer processes. The critical inversion density was also evaluated for the same set of samples.