PbS quantum dots and BaF₂ : Tm³⁺ nanocrystals co-doped glass for ultra-broadband near-infrared emission [Invited]

With the rapid growth of optical communications traffic, the demand for broadband optical amplifiers continues to increase. It is necessary to develop a gain medium that covers more optical communication bands. We precipitated PbS quantum dots (QDs) and BaF₂ : Tm³⁺ nanocrystals (NCs) in the same glass to form two independent emission centers. The BaF₂ NCs in the glass can provide a crystal field environment with low phonon energy for rare earth (RE) ions and prevent the energy transfer between RE ions and PbS QDs. By adjusting the heat treatment schedule, the emission of the two luminescence centers from PbS QDs and Tm³⁺ ions perfectly splices and covers the ultra-broadband near-infrared emission from 1200 nm to 2000 nm with bandwidth over 430 nm. Therefore, it is expected to be a promising broadband gain medium for fiber amplifiers.