Fluorescence properties of Er³⁺:LiNbO₃ sol-gel powder

This paper reports the synthesis and the upconversion green emission (⁴S_3/2→⁴I_15/2) of Er³⁺:LiNbO₃ sol-gel powder upon excitation with two NIR wavelengths (993 and 800 nm). Normal photoluminescence spectra measured at 331 and 399 nm show a bright green emission at 543 nm. Lifetimes of this green emission transition both in the upconversion and the normal emission have been compared. An NIR lasing transition (⁴I_13/2→⁴I_15/2) at 1549 nm has also been measured by pumping the sample with an Ar⁺ laser (514 nm). Details concerning the sample structure and particles are reported here from the profiles of the X-ray diffraction (XRD) and the scanning electron microscopy (SEM) images.