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

Abstract

This paper reports on the absorption, visible and near-infrared luminescence properties of Er(3+), Nd(3+), Pr(3+) and Ho(3+)-doped alkali fluoride zinc boro germanate glasses. The x-ray diffraction (XRD) and differential thermal analysis (DTA) profiles of the host glass have been carried out, to confirm its structure and thermal stability. From the measured absorption spectra, Judd-Ofelt (JO) intensity parameters (Ω(2), Ω(4) and Ω(6)) have been calculated for all the studied ions. For Pr(3+) and Ho(3+)-doped glasses, upconversion emission spectra have also been measured. Decay curves were measured for the visible emissions of Er(3+), Pr(3+) and Ho(3+) ions at 547 nm (Er(3+): green), 604 nm and 641 nm (Pr(3+): orange and red) and 658 nm (Ho(3+): red), respectively. The near-infrared emission spectra of Er(3+)/Yb(3+) and Nd(3+)-doped glasses have shown full width at half maximum (FWHM) around 95 nm (for the [Formula: see text] transition) and 63 nm (for the [Formula: see text] transition), respectively. The measured maximum decay times of [Formula: see text] transition (at wavelength 1.51 µm) are about 5.72 ms and 6.14 ms for 1.0Er(3+) and 1.0Er(3+)/ 2Yb(3+) (mol%)-codoped glasses, respectively. The maximum stimulated emission cross sections for [Formula: see text] transition of Er(3+) and Er(3+)/Yb(3+) are 5.447 × 10(-21) cm(2) and 4.540 × 10(-21) cm(2). These glasses with better thermal stability, bright visible emissions and broad near-infrared emissions should have potential applications in broadly tunable laser sources, interesting optical luminescent materials and broadband optical amplification in low-loss telecommunication windows.