Luminescence and energy transfer progress in Bi-Yb co-doped germanate glass

The Bi-doped and Bi-Yb co-doped germanate glasses were fabricated by high temperature meltingquenched technique. The absorption spectra, near-infrared (NIR) luminescence properties and decay time spectra are investigated. The results show that the NIR emission peak around 1030 nm of Yb3+ ions and two NIR emission bands around 1180 and 1300 nm of Bi ions are observed, under 690 nm LD excitation. Two NIR emission bands of Bi-related are ascribing in different Bi-related NIR emission centers, Bi-0 for 1180 nm and Bi+ ion for 1300 nm, respectively. NIR luminescence intensity of Yb3+ ions, Bi-0 and Bi+ ion is decreased. The full width at half maximum (FWHM) is broadening with the increasing in Yb2O3 concentration, and over 361 nm. The energy transfer (ET) among Yb3+, Bi-0, and Bi+ NIR emission center is also investigated, under 690 nm LD excitation. It shows that Bi-0 ion transfer energy to Bi+ and Yb3+ ions. The Yb3+ ion addition is benefit to Bi+ ions NIR luminescence. This could be the reason for broadening the FWHM. YbeBi codoped germanate glass is a promising material for broadband optical amplification. (C) 2016 Elsevier B.V. All rights reserved.