2.7 m emission of high thermally and chemically durable glasses based on AlF 3

Abstract

AlF 3 -based glasses (AlF 3 -YF 3 -CaF 2 -BaF 2 -SrF 2 -MgF 2) with enhanced thermal and chemical stability were synthesized and compared with the well-known fluorozirconate glass (ZBLAN). The 2.7â€...μm mid-infrared emission in the AlF 3 -based glasses was also investigated through the absorption and emission spectra. Both the temperature of glass transition and the characteristic temperatures (ΔT, H r, k gl) of the fluoroaluminate glasses were much larger than those of the ZBLAN glasses. The corrosion phenomenon can be observed by naked-eye, and the transmittance dropped dramatically (0% at 3â€...μm) when the ZBLAN glass was placed into distilled water. However, the AlF 3 -based glass was relatively stable. The fluoroaluminate glasses possessed large branching ratio (20%) along with the emission cross section (9.4×10 -21 â€...cm -2) of the Er 3+: 4 I 11/2 → 4 I 13/2 transition. Meanwhile, the enhanced 2.7â€... μm emission in highly Er 3+ -doped AYF glass was obtained. Therefore, these results showed that this kind of fluoride glass has a promising application for solid state lasers at 3â€...μm.