A thermally stable chalcogenide glass, a process for making the same, and an optical fiber drawn therefrom are provided. A chalcogenide glass having the composition Ge.sub.(5-y)As.sub.(32-x)Se.sub.(59+x)Te.sub.(4+y) (0.ltoreq.y.ltoreq.1 and 0.ltoreq.x.ltoreq.2) is substantially free from crystallization when it is heated past the glass transition temperature T.sub.g or drawn into optical fibers. A process for making the thermally stable chalcogenide glass includes purifying the components to remove oxides and scattering centers, batching the components in a preprocessed distillation ampoule, gettering oxygen impurities from the mixture, and heating the components to form a glass melt. An optical fiber formed from the chalcogenide glass is substantially free from crystallization and exhibits low signal loss in the near-infrared region, particularly at wavelengths of about 1.55 .mu.m.