Visible lasers of Tb³⁺ doped materials have attracted considerable attention for various applications in display techniques, visible light communication and, medical treatment. Fluoride glasses as an excellent host for visible fiber laser because of low-energy phonon distribution. Unfortunately, the small absorption cross-section of Tb³⁺ limits their development and further applications. Therefore, it’s very critical to improve the absorbance and luminescence of Tb³⁺ ions in fluoride glasses.

Recently, a research team led by the Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), using Tb³⁺/Dy³⁺ co-doped fluoride glass as a model system, not only enhances the absorption and emission intensity of Tb³⁺ ions but also increases the thermal stability of fluoride glasses. The study was published in Journal of Luminescence on 2 June, 2021.

In this study, an in-depth investigation of the optical properties of Tb³⁺ and the energy transfer process in Dy³⁺/Tb³⁺ co-doped fluoride glasses is performed. Dy³⁺ is demonstrated as a good sensitizer that can observably enhance the emission intensity of Tb³⁺ at 540 nm and absorption at 350 nm. The energy transfer processes are dependent on the Tb³⁺/Dy³⁺ concentration ratio, and the optimum ratio to obtain an efficient green emission of Tb³⁺ pumped at 350 nm is 2:0.5. The efficiency of energy transfer from Dy³⁺ to Tb³⁺ reaches up to 27.41%, and the emission integral intensity of Tb³⁺ in the 2T-0.5D sample is 1.46 times higher than that in 2T sample under identical excitation conditions. Importantly, we deeply research the energy transfer process, as shown in Figure 1. Additionally, the co-doping of Dy³⁺ can improve the resistance to crystallization in fluoride glasses.

This work provides a theoretical and experimental basis for the realization of efficient green emission by co-doping Tb³⁺ and Dy³⁺ in fluoride glasses and fibers, which can be beneficial in the preparation of visible-light optical fibers.

Figure 1. The energy transfer mechanism between Dy3+ and Tb3+. (Image by SIOM)

Article website:
https://doi.org/10.1016/j.jlumin.2021.118247

Contact:
WU Xiufeng
General Administrative Office
Shanghai Institute of Optics and Fine Mechanics, CAS
Email: xfwu@siom.ac.cn
Web: http://english.siom.cas.cn/