2.0-μm and 4.1-μm mid-infrared broadband emission enhancement in Ho3+/Yb3+ co-doped tellurite-germanate glasses

Ho3+/Yb3+ co-doped tellurite-germanate glasses with lower phonon energy (771 cm(-1)) were prepared by conventional melt-quenching method. The prepared samples were characterized by emission spectra, differential scanning calorimeter (DSC) curve, X-ray diffraction (XRD) pattern, and Raman spectra. The DSC curve shows that the sample has a good thermal stability, in which the Delta T is 202 degrees C. Compared to the recently reported tellurite glasses, the Delta T was increased by approximately 24%. Under the 980 nm laser excitation, it was found that the full width at half maximum (FWHM) of the sample at 2.0 mu m was 190 nm. Compared with the reported glasses for this type, the value was effectively improved. Meanwhile, the FWHM of the sample at 4.1 mu m was 285 nm, which has not been reported yet. This indicates that Ho3+/Yb3+ co-doped tellurite-germanate glass has a great application prospect in mid-infrared broadband fiber amplifiers.