We report the compositional dependence of absorption, emission, decay constant and quantum efficiency (QE) of GeO 2 :Al 2 O 3 :PbO:Bi 2 O 3 glass with the aim of finding the composition most suitable for a laser gain medium. As the Bi 2 O 3 content was varied we observed a non-monotonic variation in absorption spectrum. The optimized composition was 87.4GeO 2 :6Al 2 O 3 :6PbO:0.6Bi 2 O 3 (% molar) which had a QE of 67% but low transparency. We report the dependence of QE and decay constant on melting conditions of this glass. Adding 10% ZnO improved the transparency, therefore the optimized and transparent composition was 74.4GeO 2 :10ZnO:6Al 2 O 3 :6PbO:0.6Bi 2 O 3 , which had an emission full width at half maximum of 500nm.