Broadband Infrared Luminescence And Optical Amplification In PbS Doped Glasses

As optical fibers are playing a leading role in the field of optical communication, optical amplifier is always a focus for people to study. It develops from rare earth ion doped optical amplifier to Raman optical amplifier as people explores. It will be a huge revolution for the optical fiber information transmission if we can find a optical amplifier which not only have a simple configuration but also can realize the optical amplification in the whole optical communication wavelength.Recently, PbS doped quantum dot glasses have received much attention for its tunable infrared optical performance and excellent properties which make them promising as gain medium for broadband optical amplifiers. In this paper, the research history and progress of optical telecommunication, optical amplifier and quantum dot is introduced. Quantum dots glasses are studied to realize optical amplification and related experiments were done to confirm the optical gain.PbS doped quantum dots glasses, PbS codoped with Yb₂O₃ quantum dots glasses and PbS codoped with Bi₂O₃ quantum dots glasses were prepared by melting method. PbS quantum dots were precipitated after heat treatment.The optical performance of the PbS quantum dots glasses has been investigated. No emission was found in the quantum dot glasses before heat treatment excited by 980nm LD, but luminescence appears when the glasses were subjected to proper heat treatment. Both the absorption and emission peak show a red-shift with increasing thermal treatment temperature and duration.Optical amplification in three PbS doped quantum dots glasses was studied. Amplification is achieved for the first time in PbS codoped with Yb₂O₃ and PbS codoped with Bi₂O₃ quantum dots glasses with 980nm LD excitation. Optical gain enhances with the pump power. The optical gain observed both in PbS codoped with Yb₂O₃ quantum dots glasses and PbS codoped with Bi₂O₃ quantum dots glasses is stronger than PbS doped quantum dots glasses.