Chalcogenide and heavy metal oxide (HMO) glasses doped with various rare-earth elements have been studied for the possibility of developing new solid state laser materials to operate in the mid-infrared. This study investigates the synthesis and optical characterization of As<SUB>2</SUB>S<SUB>3</SUB> and Bi<SUB>2</SUB>O<SUB>3</SUB>-PbO-Ga<SUB>2</SUB>O<SUB>3</SUB> glasses doped with rare-earth elements Nd, Er, Ho, Dy, Pr and Tm. Absorption and fluorescence spectra of glasses doped with rare- earths confirmed the presence of trivalent rare-earth ions in the amorphous matrix. As<SUB>2</SUB>S<SUB>3</SUB> glasses doped with 0.4 wt% Nd showed strong fluorescence at 1.09 and 1.38 micrometers , while glasses doped with 2.0 wt% Dy exhibited fluorescence at 2.98 and 4.40 micrometers . Further, doping of Ho up to approximately 2.0 wt% showed fluorescence at 2.01 and 3.92 micrometers .