General chemical compositions of prepared glasses with low OH group concentrations are Ge025Ga0 10S0.6, Ge 25Ga,05As05S065 , (TeO2) -(PbCl2)1 with x = 0.4 to 0.6 and (TeO2) -(ZnO)1 with x = 0.75 to 0.80. Samples doped with 500 to 12000 ppm rare earth in weight were prepared. Rare earth doped glasses are homogeneous when RE concentration is less than 3000 ppm. Heterogeneous inclusions arise beyond 1000 ppm RE when doping is made with chloride or oxide.Electron microscopy, absorption and fluorescence measurements have been made. YAG:Nd. Ar, He-Ne lasers were used for excitation of photoluminiscence.The color and the optical quality of the tellurite glasses depend on crucible materials. Rare earth doping results in visible defects or inhomogeneities when concentration is larger than 1000 ppm. The chemical composition and the optical absorption of doped and undoped samples was examined. Fluorescence intensity of Pr and Dy is smaller in these HMO glasses than in the sulfide glasses, this results from higher phonon energy and higher OH concentration. Further development is required for future applications.

The preparation puxe glasses, fiber's drawing and optical characterization of chalcogenide (As2S3, As4Se3) and chalcolialide (As-Se-(Br,I), Ge-Se-I, Te-Se-Br etc) are given. Their transfer properties are suitable for a laser delivery of Er:YAG. CO and CO2 laser energy. For active optical fibers sulfide GeGaS and GeGaAsS glasses doped with Pr3 ions were prepared and their optical and fluorescence properties are studied and offer perspection applications as the spectral fluorescence. the fluorescence lifetimes G4 and the temporal fluorescence decay in a biomedical sensors.