Novel 3.1 µm and enhanced 2.7 µm emissions in Er3+ doped fluorotellurite glasses ceramic

A detailed spectroscopic analysis was reported in a series of Er3+ doped 60TeO2-30ZnF2-10NaF (mol%, TZNF60) glass ceramics. When compared with the precursor fluorotellurite glass, the corresponding glass ceramic owns broader 2.7 µm emission with a FWHM of 193 nm and relatively invariable decay lifetime of 1.40 ms. In additions, a novel 3.1 µm emission also arised from Er3+ ions 4I11/2→4I13 /2 transition was observed after heating treated the precursor glass. The combination of absolute elimination of OH group (~0.01 cm−1), and lower phonon energy of NaF crystals (~400 cm−1) is beneficial to the realization of the intense 2.7 µm and newfangled 3.1 µm emissions. By analyzing the results of XRD and SEM, it is found that more Er3+ ions embedded into the NaF nano-crystallized circumstance with the prolong of holding time, resulting in bigger stimulated emission cross sections with a maximum of 5.5 × 10−20 cm2 and longer lifetime (≥2.44 ms) and therefore greater FOM value of 12.85 × 10−20 ms cm2 for 3.1 µm emission. As result, it is considered that Er-doped fluorotellurite glass ceramic is a potential host material for the applications of broad band mid-infrared lasers.