Tm3+/Yb3+-codoped fluorophosphate glass is prepared by conventional melt-quenching method and the thermal stability of the glass is analyzed. The Judd-Ofelt parameters, radiation emission rates, radiative lifetime and branching ratios of prepared samples are calculated based on the absorption spectra. Upon excitation of a conventional 980 nm laser diode, 1.8 mu m emission is obtained from Yb3+/Tm3+ codoped fluorophosphate. Additionally, the energy transfer between Yb3+ and Tm3+ ions are quantitatively analyzed. Hence, this Yb3+/Tm3+ codoped fluorophosphate glass possessing high energy transfer efficiency and excellent thermal stability is a good candidate for efficient 1.8 mu m laser. (C) 2012 Elsevier B.V. All rights reserved.