3.1 μm mid-infrared luminescence in Er3+ doped ZnF2 modified aluminum fluoride glass

Herein, melt-quenching and Er3+ doping were used to synthesize fluoride glass specimens with low phonon energies (582 cm−1). These glass specimens exhibit intense 3.1 μm mid-infrared band emission when they are excited by a 980 nm laser diode, achieving a full width at half maximum (FWHM) of about 166 nm. This 3.1 μm emission intensity is enhanced by the introduction of ZnF2 to the AlF3-based fluoride glass. Up-conversion emission, strong near-infrared emission, and fluorescence lifetime are enhanced to different degrees by increasing the ZnF2 content. Moreover, the spectroscopic characteristics of the glass specimens and the highly efficient Er3+: 4S3/2 → 4F9/2 transition's energy transfer mechanism were investigated. The absorption spectra and emission spectra of these aluminum fluoride glass specimens were used to calculate their gain coefficients and maximum cross sections at 1.5 and 3.1 μm. Overall, the spectral properties of these prepared aluminum fluoride glass specimens demonstrate their high potential for use as infrared laser host materials.