Spectral analysis of RE3+ (RE = Er, Nd, Prand Ho):GeO2–B2O3–ZnO–LiF glasses

Abstract

This paper reports on the absorption, visible and near-infrared luminescence properties ofEr3+,Nd3+,Pr3+ and Ho3+-doped alkali fluoride zinc boro germanate glasses. The x-ray diffraction(XRD) and differential thermal analysis (DTA) profiles of the host glasshave been carried out, to confirm its structure and thermal stability. Fromthe measured absorption spectra, Judd–Ofelt (JO) intensity parameters(Ω2,Ω4 and Ω6) have been calculated for all the studied ions. ForPr3+ and Ho3+-doped glasses, upconversion emission spectra have also beenmeasured. Decay curves were measured for the visible emissions ofEr3+,Pr3+ andHo3+ ions at 547 nm(Er3+: green), 604 nm and641 nm (Pr3+: orange andred) and 658 nm (Ho3+: red), respectively. The near-infrared emission spectra ofEr3+/Yb3+ and Nd3+-doped glasses have shown full width at half maximum (FWHM) around 95 nm (for the transition) and 63 nm (for the transition), respectively. The measured maximum decay times of transition (at wavelength 1.51 µm) are about 5.72 ms and 6.14 ms for1.0Er3+ and 1.0Er3+/ 2Yb3+ (mol%)-codoped glasses, respectively. The maximum stimulated emission crosssections for transition of Er3+ and Er3+/Yb3+ are 5.447 × 10−21 cm2 and 4.540 × 10−21 cm2. These glasses with better thermal stability, bright visible emissions and broadnear-infrared emissions should have potential applications in broadly tunable laser sources,interesting optical luminescent materials and broadband optical amplification in low-losstelecommunication windows.