The effect of excited-state absorption on up-conversion photoluminescence behavior in erbium-ion doped gallium lanthanum sulphide-oxide glasses. - Voronov, Mikhail M.; Skvortsov, Alexander P.; Pevtsov, Alexander B.; Craig, Chris; Hewak, Daniel W.; Koughia, Cyril; Kasap, Safa (Journal of Luminescence, 2023)