Selective self-redox and crystal field modulation for enhanced and tuned broadband emission in chromium-doped aluminate glasses

Abstract

The emerging era of big data has stimulated the development of optical materials with broad emission region to allow data transmission of higher capacity and speed. Here, broadband emission, almost covering the region of 650–1500 nm, was realized by doping transition metal ions into versatile aluminate glasses, in which abundant microstructures and certain oxidizing capacity could be guaranteed to enrich emissions. Furthermore, we aimed to improve spectroscopic properties via the simultaneous self-redox and crystal field modulation of Cr ions and matrixes, respectively. More emission ions and more efficient centers were created to enhance the emission intensity by more than one order of magnitude. In addition, proper crystal field was created to liberate a new emission band at ∼708 nm. The results may allow the development of tunable fiber laser and amplifier using the materials and pave the way to precisely control the valence and crystal field to obtain efficient emission.