Spectroscopic properties in Er(3+)-doped germanotellurite glasses and glass ceramics for mid-infrared laser materials

Transparent Er(3+)-doped germanotellurite glass ceramics (GCs) with variable Te/Ge ratio were prepared by controllable heat-treated process. X-ray diffraction (XRD) and transmission electron microscope (TEM) confirmed the formation of nanocrystals in glass matrix. Raman spectra were used to investigate the evolution of glass structure and photon energy. Fourier transform infrared (FTIR) spectra were introduced to characterize the change of hydroxyl group (OH(−)) content. Enhanced 2.7 μm emission was achieved from Er(3+)-doped GCs upon excitation with a 980 nm laser diode (LD), and the influence of GeO(2) concentration and heat-treated temperature on the spectroscopic properties were also discussed in detail. It is found that the present Er(3+)-doped GC possesses large stimulated emission cross section at around 2.7 μm (0.85 × 10(−20) cm(2)). The advantageous spectroscopic characteristics suggest that the obtained GC may be a promising material for mid-infrared fiber lasers.