NIR luminescence from Er–Yb, Bi–Yb and Bi–Nd codoped germanate glasses for optical amplification

Abstract: In this paper, we present the near-infrared luminescence from Er–Yb, Bi–Yb, Bi–Nd codoped germanate glasses. Compared with Bi-doped glass, Bi–Yb codoped glass has shown broad infrared luminescence under 800nm excitation wavelength. The near-infrared spectra of Er3+–Yb3+ and Bi and Bi–Yb codoped glasses have shown full width at half maximum (FWHM) around 80nm, 240nm and 300nm, respectively, under 980nm and 800nm LD. The absorption band of the Yb3+ ion was located around 980nm. Though the absorption band of Yb3+ does not interact directly with the incident light at 800nm, near-infrared emission intensity has been highly increased in Bi–Yb codoped glass. We explained the relevant mechanism for the observed enhancement in the near-infrared emission intensity of Bi doped glass with Yb codoping under 800nm excitation. The measured lifetimes of Bi, Bi–Yb codoped glasses were 490μs and 815μs, respectively. The maximum stimulated emission cross sections for 1188nm and 1258nm emission bands of Bi and Bi–Yb codoped glasses were 9.003×10−21 cm2 and 5.445×10−21 cm2. These Er3+–Yb3+, Bi–Yb and Bi–Nd codoped glasses are promising materials for broadly tunable laser sources and broadband optical amplifiers. [Copyright &y& Elsevier]